gcc/c-typeck.c

   1 /* Build expressions with type checking for C compiler.
   2    Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   3    1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
   4    Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22
  23 /* This file is part of the C front end.
  24    It contains routines to build C expressions given their operands,
  25    including computing the types of the result, C-specific error checks,
  26    and some optimization.  */
  27
  28 #include "config.h"
  29 #include "system.h"
  30 #include "coretypes.h"
  31 #include "tm.h"
  32 #include "rtl.h"
  33 #include "tree.h"
  34 #include "langhooks.h"
  35 #include "c-tree.h"
  36 #include "c-lang.h"
  37 #include "tm_p.h"
  38 #include "flags.h"
  39 #include "output.h"
  40 #include "expr.h"
  41 #include "toplev.h"
  42 #include "intl.h"
  43 #include "ggc.h"
  44 #include "target.h"
  45 #include "tree-iterator.h"
  46 #include "gimple.h"
  47 #include "tree-flow.h"
  48
  49 /* Possible cases of implicit bad conversions.  Used to select
  50    diagnostic messages in convert_for_assignment.  */
  51 enum impl_conv {
  52   ic_argpass,
  53   ic_assign,
  54   ic_init,
  55   ic_return
  56 };
  57
  58 /* Whether we are building a boolean conversion inside
  59    convert_for_assignment, or some other late binary operation.  If
  60    build_binary_op is called (from code shared with C++) in this case,
  61    then the operands have already been folded and the result will not
  62    be folded again, so C_MAYBE_CONST_EXPR should not be generated.  */
  63 bool in_late_binary_op;
  64
  65 /* The level of nesting inside "__alignof__".  */
  66 int in_alignof;
  67
  68 /* The level of nesting inside "sizeof".  */
  69 int in_sizeof;
  70
  71 /* The level of nesting inside "typeof".  */
  72 int in_typeof;
  73
  74 /* Nonzero if we've already printed a "missing braces around initializer"
  75    message within this initializer.  */
  76 static int missing_braces_mentioned;
  77
  78 static int require_constant_value;
  79 static int require_constant_elements;
  80
  81 static bool null_pointer_constant_p (const_tree);
  82 static tree qualify_type (tree, tree);
  83 static int tagged_types_tu_compatible_p (const_tree, const_tree, bool *);
  84 static int comp_target_types (location_t, tree, tree);
  85 static int function_types_compatible_p (const_tree, const_tree, bool *);
  86 static int type_lists_compatible_p (const_tree, const_tree, bool *);
  87 static tree lookup_field (tree, tree);
  88 static int convert_arguments (tree, VEC(tree,gc) *, VEC(tree,gc) *, tree,
  89                               tree);
  90 static tree pointer_diff (location_t, tree, tree);
  91 static tree convert_for_assignment (location_t, tree, tree, tree,
  92                                     enum impl_conv, bool, tree, tree, int);
  93 static tree valid_compound_expr_initializer (tree, tree);
  94 static void push_string (const char *);
  95 static void push_member_name (tree);
  96 static int spelling_length (void);
  97 static char *print_spelling (char *);
  98 static void warning_init (int, const char *);
  99 static tree digest_init (location_t, tree, tree, tree, bool, bool, int);
 100 static void output_init_element (tree, tree, bool, tree, tree, int, bool,
 101                                  struct obstack *);
 102 static void output_pending_init_elements (int, struct obstack *);
 103 static int set_designator (int, struct obstack *);
 104 static void push_range_stack (tree, struct obstack *);
 105 static void add_pending_init (tree, tree, tree, bool, struct obstack *);
 106 static void set_nonincremental_init (struct obstack *);
 107 static void set_nonincremental_init_from_string (tree, struct obstack *);
 108 static tree find_init_member (tree, struct obstack *);
 109 static void readonly_error (tree, enum lvalue_use);
 110 static void readonly_warning (tree, enum lvalue_use);
 111 static int lvalue_or_else (const_tree, enum lvalue_use);
 112 static void record_maybe_used_decl (tree);
 113 static int comptypes_internal (const_tree, const_tree, bool *);
 114 \f
 115 /* Return true if EXP is a null pointer constant, false otherwise.  */
 116
 117 static bool
 118 null_pointer_constant_p (const_tree expr)
 119 {
 120   /* This should really operate on c_expr structures, but they aren't
 121      yet available everywhere required.  */
 122   tree type = TREE_TYPE (expr);
 123   return (TREE_CODE (expr) == INTEGER_CST
 124           && !TREE_OVERFLOW (expr)
 125           && integer_zerop (expr)
 126           && (INTEGRAL_TYPE_P (type)
 127               || (TREE_CODE (type) == POINTER_TYPE
 128                   && VOID_TYPE_P (TREE_TYPE (type))
 129                   && TYPE_QUALS (TREE_TYPE (type)) == TYPE_UNQUALIFIED)));
 130 }
 131
 132 /* EXPR may appear in an unevaluated part of an integer constant
 133    expression, but not in an evaluated part.  Wrap it in a
 134    C_MAYBE_CONST_EXPR, or mark it with TREE_OVERFLOW if it is just an
 135    INTEGER_CST and we cannot create a C_MAYBE_CONST_EXPR.  */
 136
 137 static tree
 138 note_integer_operands (tree expr)
 139 {
 140   tree ret;
 141   if (TREE_CODE (expr) == INTEGER_CST && in_late_binary_op)
 142     {
 143       ret = copy_node (expr);
 144       TREE_OVERFLOW (ret) = 1;
 145     }
 146   else
 147     {
 148       ret = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (expr), NULL_TREE, expr);
 149       C_MAYBE_CONST_EXPR_INT_OPERANDS (ret) = 1;
 150     }
 151   return ret;
 152 }
 153
 154 /* Having checked whether EXPR may appear in an unevaluated part of an
 155    integer constant expression and found that it may, remove any
 156    C_MAYBE_CONST_EXPR noting this fact and return the resulting
 157    expression.  */
 158
 159 static inline tree
 160 remove_c_maybe_const_expr (tree expr)
 161 {
 162   if (TREE_CODE (expr) == C_MAYBE_CONST_EXPR)
 163     return C_MAYBE_CONST_EXPR_EXPR (expr);
 164   else
 165     return expr;
 166 }
 167
 168 \f/* This is a cache to hold if two types are compatible or not.  */
 169
 170 struct tagged_tu_seen_cache {
 171   const struct tagged_tu_seen_cache * next;
 172   const_tree t1;
 173   const_tree t2;
 174   /* The return value of tagged_types_tu_compatible_p if we had seen
 175      these two types already.  */
 176   int val;
 177 };
 178
 179 static const struct tagged_tu_seen_cache * tagged_tu_seen_base;
 180 static void free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *);
 181
 182 /* Do `exp = require_complete_type (exp);' to make sure exp
 183    does not have an incomplete type.  (That includes void types.)  */
 184
 185 tree
 186 require_complete_type (tree value)
 187 {
 188   tree type = TREE_TYPE (value);
 189
 190   if (value == error_mark_node || type == error_mark_node)
 191     return error_mark_node;
 192
 193   /* First, detect a valid value with a complete type.  */
 194   if (COMPLETE_TYPE_P (type))
 195     return value;
 196
 197   c_incomplete_type_error (value, type);
 198   return error_mark_node;
 199 }
 200
 201 /* Print an error message for invalid use of an incomplete type.
 202    VALUE is the expression that was used (or 0 if that isn't known)
 203    and TYPE is the type that was invalid.  */
 204
 205 void
 206 c_incomplete_type_error (const_tree value, const_tree type)
 207 {
 208   const char *type_code_string;
 209
 210   /* Avoid duplicate error message.  */
 211   if (TREE_CODE (type) == ERROR_MARK)
 212     return;
 213
 214   if (value != 0 && (TREE_CODE (value) == VAR_DECL
 215                      || TREE_CODE (value) == PARM_DECL))
 216     error ("%qD has an incomplete type", value);
 217   else
 218     {
 219     retry:
 220       /* We must print an error message.  Be clever about what it says.  */
 221
 222       switch (TREE_CODE (type))
 223         {
 224         case RECORD_TYPE:
 225           type_code_string = "struct";
 226           break;
 227
 228         case UNION_TYPE:
 229           type_code_string = "union";
 230           break;
 231
 232         case ENUMERAL_TYPE:
 233           type_code_string = "enum";
 234           break;
 235
 236         case VOID_TYPE:
 237           error ("invalid use of void expression");
 238           return;
 239
 240         case ARRAY_TYPE:
 241           if (TYPE_DOMAIN (type))
 242             {
 243               if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL)
 244                 {
 245                   error ("invalid use of flexible array member");
 246                   return;
 247                 }
 248               type = TREE_TYPE (type);
 249               goto retry;
 250             }
 251           error ("invalid use of array with unspecified bounds");
 252           return;
 253
 254         default:
 255           gcc_unreachable ();
 256         }
 257
 258       if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
 259         error ("invalid use of undefined type %<%s %E%>",
 260                type_code_string, TYPE_NAME (type));
 261       else
 262         /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL.  */
 263         error ("invalid use of incomplete typedef %qD", TYPE_NAME (type));
 264     }
 265 }
 266
 267 /* Given a type, apply default promotions wrt unnamed function
 268    arguments and return the new type.  */
 269
 270 tree
 271 c_type_promotes_to (tree type)
 272 {
 273   if (TYPE_MAIN_VARIANT (type) == float_type_node)
 274     return double_type_node;
 275
 276   if (c_promoting_integer_type_p (type))
 277     {
 278       /* Preserve unsignedness if not really getting any wider.  */
 279       if (TYPE_UNSIGNED (type)
 280           && (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)))
 281         return unsigned_type_node;
 282       return integer_type_node;
 283     }
 284
 285   return type;
 286 }
 287
 288 /* Return true if between two named address spaces, whether there is a superset
 289    named address space that encompasses both address spaces.  If there is a
 290    superset, return which address space is the superset.  */
 291
 292 static bool
 293 addr_space_superset (addr_space_t as1, addr_space_t as2, addr_space_t *common)
 294 {
 295   if (as1 == as2)
 296     {
 297       *common = as1;
 298       return true;
 299     }
 300   else if (targetm.addr_space.subset_p (as1, as2))
 301     {
 302       *common = as2;
 303       return true;
 304     }
 305   else if (targetm.addr_space.subset_p (as2, as1))
 306     {
 307       *common = as1;
 308       return true;
 309     }
 310   else
 311     return false;
 312 }
 313
 314 /* Return a variant of TYPE which has all the type qualifiers of LIKE
 315    as well as those of TYPE.  */
 316
 317 static tree
 318 qualify_type (tree type, tree like)
 319 {
 320   addr_space_t as_type = TYPE_ADDR_SPACE (type);
 321   addr_space_t as_like = TYPE_ADDR_SPACE (like);
 322   addr_space_t as_common;
 323
 324   /* If the two named address spaces are different, determine the common
 325      superset address space.  If there isn't one, raise an error.  */
 326   if (!addr_space_superset (as_type, as_like, &as_common))
 327     {
 328       as_common = as_type;
 329       error ("%qT and %qT are in disjoint named address spaces",
 330              type, like);
 331     }
 332
 333   return c_build_qualified_type (type,
 334                                  TYPE_QUALS_NO_ADDR_SPACE (type)
 335                                  | TYPE_QUALS_NO_ADDR_SPACE (like)
 336                                  | ENCODE_QUAL_ADDR_SPACE (as_common));
 337 }
 338
 339 /* Return true iff the given tree T is a variable length array.  */
 340
 341 bool
 342 c_vla_type_p (const_tree t)
 343 {
 344   if (TREE_CODE (t) == ARRAY_TYPE
 345       && C_TYPE_VARIABLE_SIZE (t))
 346     return true;
 347   return false;
 348 }
 349 \f
 350 /* Return the composite type of two compatible types.
 351
 352    We assume that comptypes has already been done and returned
 353    nonzero; if that isn't so, this may crash.  In particular, we
 354    assume that qualifiers match.  */
 355
 356 tree
 357 composite_type (tree t1, tree t2)
 358 {
 359   enum tree_code code1;
 360   enum tree_code code2;
 361   tree attributes;
 362
 363   /* Save time if the two types are the same.  */
 364
 365   if (t1 == t2) return t1;
 366
 367   /* If one type is nonsense, use the other.  */
 368   if (t1 == error_mark_node)
 369     return t2;
 370   if (t2 == error_mark_node)
 371     return t1;
 372
 373   code1 = TREE_CODE (t1);
 374   code2 = TREE_CODE (t2);
 375
 376   /* Merge the attributes.  */
 377   attributes = targetm.merge_type_attributes (t1, t2);
 378
 379   /* If one is an enumerated type and the other is the compatible
 380      integer type, the composite type might be either of the two
 381      (DR#013 question 3).  For consistency, use the enumerated type as
 382      the composite type.  */
 383
 384   if (code1 == ENUMERAL_TYPE && code2 == INTEGER_TYPE)
 385     return t1;
 386   if (code2 == ENUMERAL_TYPE && code1 == INTEGER_TYPE)
 387     return t2;
 388
 389   gcc_assert (code1 == code2);
 390
 391   switch (code1)
 392     {
 393     case POINTER_TYPE:
 394       /* For two pointers, do this recursively on the target type.  */
 395       {
 396         tree pointed_to_1 = TREE_TYPE (t1);
 397         tree pointed_to_2 = TREE_TYPE (t2);
 398         tree target = composite_type (pointed_to_1, pointed_to_2);
 399         t1 = build_pointer_type (target);
 400         t1 = build_type_attribute_variant (t1, attributes);
 401         return qualify_type (t1, t2);
 402       }
 403
 404     case ARRAY_TYPE:
 405       {
 406         tree elt = composite_type (TREE_TYPE (t1), TREE_TYPE (t2));
 407         int quals;
 408         tree unqual_elt;
 409         tree d1 = TYPE_DOMAIN (t1);
 410         tree d2 = TYPE_DOMAIN (t2);
 411         bool d1_variable, d2_variable;
 412         bool d1_zero, d2_zero;
 413         bool t1_complete, t2_complete;
 414
 415         /* We should not have any type quals on arrays at all.  */
 416         gcc_assert (!TYPE_QUALS_NO_ADDR_SPACE (t1)
 417                     && !TYPE_QUALS_NO_ADDR_SPACE (t2));
 418
 419         t1_complete = COMPLETE_TYPE_P (t1);
 420         t2_complete = COMPLETE_TYPE_P (t2);
 421
 422         d1_zero = d1 == 0 || !TYPE_MAX_VALUE (d1);
 423         d2_zero = d2 == 0 || !TYPE_MAX_VALUE (d2);
 424
 425         d1_variable = (!d1_zero
 426                        && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
 427                            || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST));
 428         d2_variable = (!d2_zero
 429                        && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
 430                            || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST));
 431         d1_variable = d1_variable || (d1_zero && c_vla_type_p (t1));
 432         d2_variable = d2_variable || (d2_zero && c_vla_type_p (t2));
 433
 434         /* Save space: see if the result is identical to one of the args.  */
 435         if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1)
 436             && (d2_variable || d2_zero || !d1_variable))
 437           return build_type_attribute_variant (t1, attributes);
 438         if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2)
 439             && (d1_variable || d1_zero || !d2_variable))
 440           return build_type_attribute_variant (t2, attributes);
 441
 442         if (elt == TREE_TYPE (t1) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1))
 443           return build_type_attribute_variant (t1, attributes);
 444         if (elt == TREE_TYPE (t2) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1))
 445           return build_type_attribute_variant (t2, attributes);
 446
 447         /* Merge the element types, and have a size if either arg has
 448            one.  We may have qualifiers on the element types.  To set
 449            up TYPE_MAIN_VARIANT correctly, we need to form the
 450            composite of the unqualified types and add the qualifiers
 451            back at the end.  */
 452         quals = TYPE_QUALS (strip_array_types (elt));
 453         unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
 454         t1 = build_array_type (unqual_elt,
 455                                TYPE_DOMAIN ((TYPE_DOMAIN (t1)
 456                                              && (d2_variable
 457                                                  || d2_zero
 458                                                  || !d1_variable))
 459                                             ? t1
 460                                             : t2));
 461         /* Ensure a composite type involving a zero-length array type
 462            is a zero-length type not an incomplete type.  */
 463         if (d1_zero && d2_zero
 464             && (t1_complete || t2_complete)
 465             && !COMPLETE_TYPE_P (t1))
 466           {
 467             TYPE_SIZE (t1) = bitsize_zero_node;
 468             TYPE_SIZE_UNIT (t1) = size_zero_node;
 469           }
 470         t1 = c_build_qualified_type (t1, quals);
 471         return build_type_attribute_variant (t1, attributes);
 472       }
 473
 474     case ENUMERAL_TYPE:
 475     case RECORD_TYPE:
 476     case UNION_TYPE:
 477       if (attributes != NULL)
 478         {
 479           /* Try harder not to create a new aggregate type.  */
 480           if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
 481             return t1;
 482           if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
 483             return t2;
 484         }
 485       return build_type_attribute_variant (t1, attributes);
 486
 487     case FUNCTION_TYPE:
 488       /* Function types: prefer the one that specified arg types.
 489          If both do, merge the arg types.  Also merge the return types.  */
 490       {
 491         tree valtype = composite_type (TREE_TYPE (t1), TREE_TYPE (t2));
 492         tree p1 = TYPE_ARG_TYPES (t1);
 493         tree p2 = TYPE_ARG_TYPES (t2);
 494         int len;
 495         tree newargs, n;
 496         int i;
 497
 498         /* Save space: see if the result is identical to one of the args.  */
 499         if (valtype == TREE_TYPE (t1) && !TYPE_ARG_TYPES (t2))
 500           return build_type_attribute_variant (t1, attributes);
 501         if (valtype == TREE_TYPE (t2) && !TYPE_ARG_TYPES (t1))
 502           return build_type_attribute_variant (t2, attributes);
 503
 504         /* Simple way if one arg fails to specify argument types.  */
 505         if (TYPE_ARG_TYPES (t1) == 0)
 506          {
 507             t1 = build_function_type (valtype, TYPE_ARG_TYPES (t2));
 508             t1 = build_type_attribute_variant (t1, attributes);
 509             return qualify_type (t1, t2);
 510          }
 511         if (TYPE_ARG_TYPES (t2) == 0)
 512          {
 513            t1 = build_function_type (valtype, TYPE_ARG_TYPES (t1));
 514            t1 = build_type_attribute_variant (t1, attributes);
 515            return qualify_type (t1, t2);
 516          }
 517
 518         /* If both args specify argument types, we must merge the two
 519            lists, argument by argument.  */
 520         /* Tell global_bindings_p to return false so that variable_size
 521            doesn't die on VLAs in parameter types.  */
 522         c_override_global_bindings_to_false = true;
 523
 524         len = list_length (p1);
 525         newargs = 0;
 526
 527         for (i = 0; i < len; i++)
 528           newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
 529
 530         n = newargs;
 531
 532         for (; p1;
 533              p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n))
 534           {
 535             /* A null type means arg type is not specified.
 536                Take whatever the other function type has.  */
 537             if (TREE_VALUE (p1) == 0)
 538               {
 539                 TREE_VALUE (n) = TREE_VALUE (p2);
 540                 goto parm_done;
 541               }
 542             if (TREE_VALUE (p2) == 0)
 543               {
 544                 TREE_VALUE (n) = TREE_VALUE (p1);
 545                 goto parm_done;
 546               }
 547
 548             /* Given  wait (union {union wait *u; int *i} *)
 549                and  wait (union wait *),
 550                prefer  union wait *  as type of parm.  */
 551             if (TREE_CODE (TREE_VALUE (p1)) == UNION_TYPE
 552                 && TREE_VALUE (p1) != TREE_VALUE (p2))
 553               {
 554                 tree memb;
 555                 tree mv2 = TREE_VALUE (p2);
 556                 if (mv2 && mv2 != error_mark_node
 557                     && TREE_CODE (mv2) != ARRAY_TYPE)
 558                   mv2 = TYPE_MAIN_VARIANT (mv2);
 559                 for (memb = TYPE_FIELDS (TREE_VALUE (p1));
 560                      memb; memb = TREE_CHAIN (memb))
 561                   {
 562                     tree mv3 = TREE_TYPE (memb);
 563                     if (mv3 && mv3 != error_mark_node
 564                         && TREE_CODE (mv3) != ARRAY_TYPE)
 565                       mv3 = TYPE_MAIN_VARIANT (mv3);
 566                     if (comptypes (mv3, mv2))
 567                       {
 568                         TREE_VALUE (n) = composite_type (TREE_TYPE (memb),
 569                                                          TREE_VALUE (p2));
 570                         pedwarn (input_location, OPT_pedantic,
 571                                  "function types not truly compatible in ISO C");
 572                         goto parm_done;
 573                       }
 574                   }
 575               }
 576             if (TREE_CODE (TREE_VALUE (p2)) == UNION_TYPE
 577                 && TREE_VALUE (p2) != TREE_VALUE (p1))
 578               {
 579                 tree memb;
 580                 tree mv1 = TREE_VALUE (p1);
 581                 if (mv1 && mv1 != error_mark_node
 582                     && TREE_CODE (mv1) != ARRAY_TYPE)
 583                   mv1 = TYPE_MAIN_VARIANT (mv1);
 584                 for (memb = TYPE_FIELDS (TREE_VALUE (p2));
 585                      memb; memb = TREE_CHAIN (memb))
 586                   {
 587                     tree mv3 = TREE_TYPE (memb);
 588                     if (mv3 && mv3 != error_mark_node
 589                         && TREE_CODE (mv3) != ARRAY_TYPE)
 590                       mv3 = TYPE_MAIN_VARIANT (mv3);
 591                     if (comptypes (mv3, mv1))
 592                       {
 593                         TREE_VALUE (n) = composite_type (TREE_TYPE (memb),
 594                                                          TREE_VALUE (p1));
 595                         pedwarn (input_location, OPT_pedantic,
 596                                  "function types not truly compatible in ISO C");
 597                         goto parm_done;
 598                       }
 599                   }
 600               }
 601             TREE_VALUE (n) = composite_type (TREE_VALUE (p1), TREE_VALUE (p2));
 602           parm_done: ;
 603           }
 604
 605         c_override_global_bindings_to_false = false;
 606         t1 = build_function_type (valtype, newargs);
 607         t1 = qualify_type (t1, t2);
 608         /* ... falls through ...  */
 609       }
 610
 611     default:
 612       return build_type_attribute_variant (t1, attributes);
 613     }
 614
 615 }
 616
 617 /* Return the type of a conditional expression between pointers to
 618    possibly differently qualified versions of compatible types.
 619
 620    We assume that comp_target_types has already been done and returned
 621    nonzero; if that isn't so, this may crash.  */
 622
 623 static tree
 624 common_pointer_type (tree t1, tree t2)
 625 {
 626   tree attributes;
 627   tree pointed_to_1, mv1;
 628   tree pointed_to_2, mv2;
 629   tree target;
 630   unsigned target_quals;
 631   addr_space_t as1, as2, as_common;
 632   int quals1, quals2;
 633
 634   /* Save time if the two types are the same.  */
 635
 636   if (t1 == t2) return t1;
 637
 638   /* If one type is nonsense, use the other.  */
 639   if (t1 == error_mark_node)
 640     return t2;
 641   if (t2 == error_mark_node)
 642     return t1;
 643
 644   gcc_assert (TREE_CODE (t1) == POINTER_TYPE
 645               && TREE_CODE (t2) == POINTER_TYPE);
 646
 647   /* Merge the attributes.  */
 648   attributes = targetm.merge_type_attributes (t1, t2);
 649
 650   /* Find the composite type of the target types, and combine the
 651      qualifiers of the two types' targets.  Do not lose qualifiers on
 652      array element types by taking the TYPE_MAIN_VARIANT.  */
 653   mv1 = pointed_to_1 = TREE_TYPE (t1);
 654   mv2 = pointed_to_2 = TREE_TYPE (t2);
 655   if (TREE_CODE (mv1) != ARRAY_TYPE)
 656     mv1 = TYPE_MAIN_VARIANT (pointed_to_1);
 657   if (TREE_CODE (mv2) != ARRAY_TYPE)
 658     mv2 = TYPE_MAIN_VARIANT (pointed_to_2);
 659   target = composite_type (mv1, mv2);
 660
 661   /* For function types do not merge const qualifiers, but drop them
 662      if used inconsistently.  The middle-end uses these to mark const
 663      and noreturn functions.  */
 664   quals1 = TYPE_QUALS_NO_ADDR_SPACE (pointed_to_1);
 665   quals2 = TYPE_QUALS_NO_ADDR_SPACE (pointed_to_2);
 666
 667   if (TREE_CODE (pointed_to_1) == FUNCTION_TYPE)
 668     target_quals = (quals1 & quals2);
 669   else
 670     target_quals = (quals1 | quals2);
 671
 672   /* If the two named address spaces are different, determine the common
 673      superset address space.  This is guaranteed to exist due to the
 674      assumption that comp_target_type returned non-zero.  */
 675   as1 = TYPE_ADDR_SPACE (pointed_to_1);
 676   as2 = TYPE_ADDR_SPACE (pointed_to_2);
 677   if (!addr_space_superset (as1, as2, &as_common))
 678     gcc_unreachable ();
 679
 680   target_quals |= ENCODE_QUAL_ADDR_SPACE (as_common);
 681
 682   t1 = build_pointer_type (c_build_qualified_type (target, target_quals));
 683   return build_type_attribute_variant (t1, attributes);
 684 }
 685
 686 /* Return the common type for two arithmetic types under the usual
 687    arithmetic conversions.  The default conversions have already been
 688    applied, and enumerated types converted to their compatible integer
 689    types.  The resulting type is unqualified and has no attributes.
 690
 691    This is the type for the result of most arithmetic operations
 692    if the operands have the given two types.  */
 693
 694 static tree
 695 c_common_type (tree t1, tree t2)
 696 {
 697   enum tree_code code1;
 698   enum tree_code code2;
 699
 700   /* If one type is nonsense, use the other.  */
 701   if (t1 == error_mark_node)
 702     return t2;
 703   if (t2 == error_mark_node)
 704     return t1;
 705
 706   if (TYPE_QUALS (t1) != TYPE_UNQUALIFIED)
 707     t1 = TYPE_MAIN_VARIANT (t1);
 708
 709   if (TYPE_QUALS (t2) != TYPE_UNQUALIFIED)
 710     t2 = TYPE_MAIN_VARIANT (t2);
 711
 712   if (TYPE_ATTRIBUTES (t1) != NULL_TREE)
 713     t1 = build_type_attribute_variant (t1, NULL_TREE);
 714
 715   if (TYPE_ATTRIBUTES (t2) != NULL_TREE)
 716     t2 = build_type_attribute_variant (t2, NULL_TREE);
 717
 718   /* Save time if the two types are the same.  */
 719
 720   if (t1 == t2) return t1;
 721
 722   code1 = TREE_CODE (t1);
 723   code2 = TREE_CODE (t2);
 724
 725   gcc_assert (code1 == VECTOR_TYPE || code1 == COMPLEX_TYPE
 726               || code1 == FIXED_POINT_TYPE || code1 == REAL_TYPE
 727               || code1 == INTEGER_TYPE);
 728   gcc_assert (code2 == VECTOR_TYPE || code2 == COMPLEX_TYPE
 729               || code2 == FIXED_POINT_TYPE || code2 == REAL_TYPE
 730               || code2 == INTEGER_TYPE);
 731
 732   /* When one operand is a decimal float type, the other operand cannot be
 733      a generic float type or a complex type.  We also disallow vector types
 734      here.  */
 735   if ((DECIMAL_FLOAT_TYPE_P (t1) || DECIMAL_FLOAT_TYPE_P (t2))
 736       && !(DECIMAL_FLOAT_TYPE_P (t1) && DECIMAL_FLOAT_TYPE_P (t2)))
 737     {
 738       if (code1 == VECTOR_TYPE || code2 == VECTOR_TYPE)
 739         {
 740           error ("can%'t mix operands of decimal float and vector types");
 741           return error_mark_node;
 742         }
 743       if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
 744         {
 745           error ("can%'t mix operands of decimal float and complex types");
 746           return error_mark_node;
 747         }
 748       if (code1 == REAL_TYPE && code2 == REAL_TYPE)
 749         {
 750           error ("can%'t mix operands of decimal float and other float types");
 751           return error_mark_node;
 752         }
 753     }
 754
 755   /* If one type is a vector type, return that type.  (How the usual
 756      arithmetic conversions apply to the vector types extension is not
 757      precisely specified.)  */
 758   if (code1 == VECTOR_TYPE)
 759     return t1;
 760
 761   if (code2 == VECTOR_TYPE)
 762     return t2;
 763
 764   /* If one type is complex, form the common type of the non-complex
 765      components, then make that complex.  Use T1 or T2 if it is the
 766      required type.  */
 767   if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
 768     {
 769       tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
 770       tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
 771       tree subtype = c_common_type (subtype1, subtype2);
 772
 773       if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
 774         return t1;
 775       else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
 776         return t2;
 777       else
 778         return build_complex_type (subtype);
 779     }
 780
 781   /* If only one is real, use it as the result.  */
 782
 783   if (code1 == REAL_TYPE && code2 != REAL_TYPE)
 784     return t1;
 785
 786   if (code2 == REAL_TYPE && code1 != REAL_TYPE)
 787     return t2;
 788
 789   /* If both are real and either are decimal floating point types, use
 790      the decimal floating point type with the greater precision. */
 791
 792   if (code1 == REAL_TYPE && code2 == REAL_TYPE)
 793     {
 794       if (TYPE_MAIN_VARIANT (t1) == dfloat128_type_node
 795           || TYPE_MAIN_VARIANT (t2) == dfloat128_type_node)
 796         return dfloat128_type_node;
 797       else if (TYPE_MAIN_VARIANT (t1) == dfloat64_type_node
 798                || TYPE_MAIN_VARIANT (t2) == dfloat64_type_node)
 799         return dfloat64_type_node;
 800       else if (TYPE_MAIN_VARIANT (t1) == dfloat32_type_node
 801                || TYPE_MAIN_VARIANT (t2) == dfloat32_type_node)
 802         return dfloat32_type_node;
 803     }
 804
 805   /* Deal with fixed-point types.  */
 806   if (code1 == FIXED_POINT_TYPE || code2 == FIXED_POINT_TYPE)
 807     {
 808       unsigned int unsignedp = 0, satp = 0;
 809       enum machine_mode m1, m2;
 810       unsigned int fbit1, ibit1, fbit2, ibit2, max_fbit, max_ibit;
 811
 812       m1 = TYPE_MODE (t1);
 813       m2 = TYPE_MODE (t2);
 814
 815       /* If one input type is saturating, the result type is saturating.  */
 816       if (TYPE_SATURATING (t1) || TYPE_SATURATING (t2))
 817         satp = 1;
 818
 819       /* If both fixed-point types are unsigned, the result type is unsigned.
 820          When mixing fixed-point and integer types, follow the sign of the
 821          fixed-point type.
 822          Otherwise, the result type is signed.  */
 823       if ((TYPE_UNSIGNED (t1) && TYPE_UNSIGNED (t2)
 824            && code1 == FIXED_POINT_TYPE && code2 == FIXED_POINT_TYPE)
 825           || (code1 == FIXED_POINT_TYPE && code2 != FIXED_POINT_TYPE
 826               && TYPE_UNSIGNED (t1))
 827           || (code1 != FIXED_POINT_TYPE && code2 == FIXED_POINT_TYPE
 828               && TYPE_UNSIGNED (t2)))
 829         unsignedp = 1;
 830
 831       /* The result type is signed.  */
 832       if (unsignedp == 0)
 833         {
 834           /* If the input type is unsigned, we need to convert to the
 835              signed type.  */
 836           if (code1 == FIXED_POINT_TYPE && TYPE_UNSIGNED (t1))
 837             {
 838               enum mode_class mclass = (enum mode_class) 0;
 839               if (GET_MODE_CLASS (m1) == MODE_UFRACT)
 840                 mclass = MODE_FRACT;
 841               else if (GET_MODE_CLASS (m1) == MODE_UACCUM)
 842                 mclass = MODE_ACCUM;
 843               else
 844                 gcc_unreachable ();
 845               m1 = mode_for_size (GET_MODE_PRECISION (m1), mclass, 0);
 846             }
 847           if (code2 == FIXED_POINT_TYPE && TYPE_UNSIGNED (t2))
 848             {
 849               enum mode_class mclass = (enum mode_class) 0;
 850               if (GET_MODE_CLASS (m2) == MODE_UFRACT)
 851                 mclass = MODE_FRACT;
 852               else if (GET_MODE_CLASS (m2) == MODE_UACCUM)
 853                 mclass = MODE_ACCUM;
 854               else
 855                 gcc_unreachable ();
 856               m2 = mode_for_size (GET_MODE_PRECISION (m2), mclass, 0);
 857             }
 858         }
 859
 860       if (code1 == FIXED_POINT_TYPE)
 861         {
 862           fbit1 = GET_MODE_FBIT (m1);
 863           ibit1 = GET_MODE_IBIT (m1);
 864         }
 865       else
 866         {
 867           fbit1 = 0;
 868           /* Signed integers need to subtract one sign bit.  */
 869           ibit1 = TYPE_PRECISION (t1) - (!TYPE_UNSIGNED (t1));
 870         }
 871
 872       if (code2 == FIXED_POINT_TYPE)
 873         {
 874           fbit2 = GET_MODE_FBIT (m2);
 875           ibit2 = GET_MODE_IBIT (m2);
 876         }
 877       else
 878         {
 879           fbit2 = 0;
 880           /* Signed integers need to subtract one sign bit.  */
 881           ibit2 = TYPE_PRECISION (t2) - (!TYPE_UNSIGNED (t2));
 882         }
 883
 884       max_ibit = ibit1 >= ibit2 ?  ibit1 : ibit2;
 885       max_fbit = fbit1 >= fbit2 ?  fbit1 : fbit2;
 886       return c_common_fixed_point_type_for_size (max_ibit, max_fbit, unsignedp,
 887                                                  satp);
 888     }
 889
 890   /* Both real or both integers; use the one with greater precision.  */
 891
 892   if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
 893     return t1;
 894   else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
 895     return t2;
 896
 897   /* Same precision.  Prefer long longs to longs to ints when the
 898      same precision, following the C99 rules on integer type rank
 899      (which are equivalent to the C90 rules for C90 types).  */
 900
 901   if (TYPE_MAIN_VARIANT (t1) == long_long_unsigned_type_node
 902       || TYPE_MAIN_VARIANT (t2) == long_long_unsigned_type_node)
 903     return long_long_unsigned_type_node;
 904
 905   if (TYPE_MAIN_VARIANT (t1) == long_long_integer_type_node
 906       || TYPE_MAIN_VARIANT (t2) == long_long_integer_type_node)
 907     {
 908       if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
 909         return long_long_unsigned_type_node;
 910       else
 911         return long_long_integer_type_node;
 912     }
 913
 914   if (TYPE_MAIN_VARIANT (t1) == long_unsigned_type_node
 915       || TYPE_MAIN_VARIANT (t2) == long_unsigned_type_node)
 916     return long_unsigned_type_node;
 917
 918   if (TYPE_MAIN_VARIANT (t1) == long_integer_type_node
 919       || TYPE_MAIN_VARIANT (t2) == long_integer_type_node)
 920     {
 921       /* But preserve unsignedness from the other type,
 922          since long cannot hold all the values of an unsigned int.  */
 923       if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
 924         return long_unsigned_type_node;
 925       else
 926         return long_integer_type_node;
 927     }
 928
 929   /* Likewise, prefer long double to double even if same size.  */
 930   if (TYPE_MAIN_VARIANT (t1) == long_double_type_node
 931       || TYPE_MAIN_VARIANT (t2) == long_double_type_node)
 932     return long_double_type_node;
 933
 934   /* Otherwise prefer the unsigned one.  */
 935
 936   if (TYPE_UNSIGNED (t1))
 937     return t1;
 938   else
 939     return t2;
 940 }
 941 \f
 942 /* Wrapper around c_common_type that is used by c-common.c and other
 943    front end optimizations that remove promotions.  ENUMERAL_TYPEs
 944    are allowed here and are converted to their compatible integer types.
 945    BOOLEAN_TYPEs are allowed here and return either boolean_type_node or
 946    preferably a non-Boolean type as the common type.  */
 947 tree
 948 common_type (tree t1, tree t2)
 949 {
 950   if (TREE_CODE (t1) == ENUMERAL_TYPE)
 951     t1 = c_common_type_for_size (TYPE_PRECISION (t1), 1);
 952   if (TREE_CODE (t2) == ENUMERAL_TYPE)
 953     t2 = c_common_type_for_size (TYPE_PRECISION (t2), 1);
 954
 955   /* If both types are BOOLEAN_TYPE, then return boolean_type_node.  */
 956   if (TREE_CODE (t1) == BOOLEAN_TYPE
 957       && TREE_CODE (t2) == BOOLEAN_TYPE)
 958     return boolean_type_node;
 959
 960   /* If either type is BOOLEAN_TYPE, then return the other.  */
 961   if (TREE_CODE (t1) == BOOLEAN_TYPE)
 962     return t2;
 963   if (TREE_CODE (t2) == BOOLEAN_TYPE)
 964     return t1;
 965
 966   return c_common_type (t1, t2);
 967 }
 968
 969 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
 970    or various other operations.  Return 2 if they are compatible
 971    but a warning may be needed if you use them together.  */
 972
 973 int
 974 comptypes (tree type1, tree type2)
 975 {
 976   const struct tagged_tu_seen_cache * tagged_tu_seen_base1 = tagged_tu_seen_base;
 977   int val;
 978
 979   val = comptypes_internal (type1, type2, NULL);
 980   free_all_tagged_tu_seen_up_to (tagged_tu_seen_base1);
 981
 982   return val;
 983 }
 984
 985 /* Like comptypes, but if it returns non-zero because enum and int are
 986    compatible, it sets *ENUM_AND_INT_P to true.  */
 987
 988 static int
 989 comptypes_check_enum_int (tree type1, tree type2, bool *enum_and_int_p)
 990 {
 991   const struct tagged_tu_seen_cache * tagged_tu_seen_base1 = tagged_tu_seen_base;
 992   int val;
 993
 994   val = comptypes_internal (type1, type2, enum_and_int_p);
 995   free_all_tagged_tu_seen_up_to (tagged_tu_seen_base1);
 996
 997   return val;
 998 }
 999 \f
1000 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
1001    or various other operations.  Return 2 if they are compatible
1002    but a warning may be needed if you use them together.  If
1003    ENUM_AND_INT_P is not NULL, and one type is an enum and the other a
1004    compatible integer type, then this sets *ENUM_AND_INT_P to true;
1005    *ENUM_AND_INT_P is never set to false.  This differs from
1006    comptypes, in that we don't free the seen types.  */
1007
1008 static int
1009 comptypes_internal (const_tree type1, const_tree type2, bool *enum_and_int_p)
1010 {
1011   const_tree t1 = type1;
1012   const_tree t2 = type2;
1013   int attrval, val;
1014
1015   /* Suppress errors caused by previously reported errors.  */
1016
1017   if (t1 == t2 || !t1 || !t2
1018       || TREE_CODE (t1) == ERROR_MARK || TREE_CODE (t2) == ERROR_MARK)
1019     return 1;
1020
1021   /* If either type is the internal version of sizetype, return the
1022      language version.  */
1023   if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
1024       && TYPE_ORIG_SIZE_TYPE (t1))
1025     t1 = TYPE_ORIG_SIZE_TYPE (t1);
1026
1027   if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
1028       && TYPE_ORIG_SIZE_TYPE (t2))
1029     t2 = TYPE_ORIG_SIZE_TYPE (t2);
1030
1031
1032   /* Enumerated types are compatible with integer types, but this is
1033      not transitive: two enumerated types in the same translation unit
1034      are compatible with each other only if they are the same type.  */
1035
1036   if (TREE_CODE (t1) == ENUMERAL_TYPE && TREE_CODE (t2) != ENUMERAL_TYPE)
1037     {
1038       t1 = c_common_type_for_size (TYPE_PRECISION (t1), TYPE_UNSIGNED (t1));
1039       if (enum_and_int_p != NULL && TREE_CODE (t2) != VOID_TYPE)
1040         *enum_and_int_p = true;
1041     }
1042   else if (TREE_CODE (t2) == ENUMERAL_TYPE && TREE_CODE (t1) != ENUMERAL_TYPE)
1043     {
1044       t2 = c_common_type_for_size (TYPE_PRECISION (t2), TYPE_UNSIGNED (t2));
1045       if (enum_and_int_p != NULL && TREE_CODE (t1) != VOID_TYPE)
1046         *enum_and_int_p = true;
1047     }
1048
1049   if (t1 == t2)
1050     return 1;
1051
1052   /* Different classes of types can't be compatible.  */
1053
1054   if (TREE_CODE (t1) != TREE_CODE (t2))
1055     return 0;
1056
1057   /* Qualifiers must match. C99 6.7.3p9 */
1058
1059   if (TYPE_QUALS (t1) != TYPE_QUALS (t2))
1060     return 0;
1061
1062   /* Allow for two different type nodes which have essentially the same
1063      definition.  Note that we already checked for equality of the type
1064      qualifiers (just above).  */
1065
1066   if (TREE_CODE (t1) != ARRAY_TYPE
1067       && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
1068     return 1;
1069
1070   /* 1 if no need for warning yet, 2 if warning cause has been seen.  */
1071   if (!(attrval = targetm.comp_type_attributes (t1, t2)))
1072      return 0;
1073
1074   /* 1 if no need for warning yet, 2 if warning cause has been seen.  */
1075   val = 0;
1076
1077   switch (TREE_CODE (t1))
1078     {
1079     case POINTER_TYPE:
1080       /* Do not remove mode or aliasing information.  */
1081       if (TYPE_MODE (t1) != TYPE_MODE (t2)
1082           || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2))
1083         break;
1084       val = (TREE_TYPE (t1) == TREE_TYPE (t2)
1085              ? 1 : comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2),
1086                                        enum_and_int_p));
1087       break;
1088
1089     case FUNCTION_TYPE:
1090       val = function_types_compatible_p (t1, t2, enum_and_int_p);
1091       break;
1092
1093     case ARRAY_TYPE:
1094       {
1095         tree d1 = TYPE_DOMAIN (t1);
1096         tree d2 = TYPE_DOMAIN (t2);
1097         bool d1_variable, d2_variable;
1098         bool d1_zero, d2_zero;
1099         val = 1;
1100
1101         /* Target types must match incl. qualifiers.  */
1102         if (TREE_TYPE (t1) != TREE_TYPE (t2)
1103             && 0 == (val = comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2),
1104                                                enum_and_int_p)))
1105           return 0;
1106
1107         /* Sizes must match unless one is missing or variable.  */
1108         if (d1 == 0 || d2 == 0 || d1 == d2)
1109           break;
1110
1111         d1_zero = !TYPE_MAX_VALUE (d1);
1112         d2_zero = !TYPE_MAX_VALUE (d2);
1113
1114         d1_variable = (!d1_zero
1115                        && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
1116                            || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST));
1117         d2_variable = (!d2_zero
1118                        && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
1119                            || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST));
1120         d1_variable = d1_variable || (d1_zero && c_vla_type_p (t1));
1121         d2_variable = d2_variable || (d2_zero && c_vla_type_p (t2));
1122
1123         if (d1_variable || d2_variable)
1124           break;
1125         if (d1_zero && d2_zero)
1126           break;
1127         if (d1_zero || d2_zero
1128             || !tree_int_cst_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2))
1129             || !tree_int_cst_equal (TYPE_MAX_VALUE (d1), TYPE_MAX_VALUE (d2)))
1130           val = 0;
1131
1132         break;
1133       }
1134
1135     case ENUMERAL_TYPE:
1136     case RECORD_TYPE:
1137     case UNION_TYPE:
1138       if (val != 1 && !same_translation_unit_p (t1, t2))
1139         {
1140           tree a1 = TYPE_ATTRIBUTES (t1);
1141           tree a2 = TYPE_ATTRIBUTES (t2);
1142
1143           if (! attribute_list_contained (a1, a2)
1144               && ! attribute_list_contained (a2, a1))
1145             break;
1146
1147           if (attrval != 2)
1148             return tagged_types_tu_compatible_p (t1, t2, enum_and_int_p);
1149           val = tagged_types_tu_compatible_p (t1, t2, enum_and_int_p);
1150         }
1151       break;
1152
1153     case VECTOR_TYPE:
1154       val = (TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1155              && comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2),
1156                                     enum_and_int_p));
1157       break;
1158
1159     default:
1160       break;
1161     }
1162   return attrval == 2 && val == 1 ? 2 : val;
1163 }
1164
1165 /* Return 1 if TTL and TTR are pointers to types that are equivalent, ignoring
1166    their qualifiers, except for named address spaces.  If the pointers point to
1167    different named addresses, then we must determine if one address space is a
1168    subset of the other.  */
1169
1170 static int
1171 comp_target_types (location_t location, tree ttl, tree ttr)
1172 {
1173   int val;
1174   tree mvl = TREE_TYPE (ttl);
1175   tree mvr = TREE_TYPE (ttr);
1176   addr_space_t asl = TYPE_ADDR_SPACE (mvl);
1177   addr_space_t asr = TYPE_ADDR_SPACE (mvr);
1178   addr_space_t as_common;
1179   bool enum_and_int_p;
1180
1181   /* Fail if pointers point to incompatible address spaces.  */
1182   if (!addr_space_superset (asl, asr, &as_common))
1183     return 0;
1184
1185   /* Do not lose qualifiers on element types of array types that are
1186      pointer targets by taking their TYPE_MAIN_VARIANT.  */
1187   if (TREE_CODE (mvl) != ARRAY_TYPE)
1188     mvl = TYPE_MAIN_VARIANT (mvl);
1189   if (TREE_CODE (mvr) != ARRAY_TYPE)
1190     mvr = TYPE_MAIN_VARIANT (mvr);
1191   enum_and_int_p = false;
1192   val = comptypes_check_enum_int (mvl, mvr, &enum_and_int_p);
1193
1194   if (val == 2)
1195     pedwarn (location, OPT_pedantic, "types are not quite compatible");
1196
1197   if (val == 1 && enum_and_int_p && warn_cxx_compat)
1198     warning_at (location, OPT_Wc___compat,
1199                 "pointer target types incompatible in C++");
1200
1201   return val;
1202 }
1203 \f
1204 /* Subroutines of `comptypes'.  */
1205
1206 /* Determine whether two trees derive from the same translation unit.
1207    If the CONTEXT chain ends in a null, that tree's context is still
1208    being parsed, so if two trees have context chains ending in null,
1209    they're in the same translation unit.  */
1210 int
1211 same_translation_unit_p (const_tree t1, const_tree t2)
1212 {
1213   while (t1 && TREE_CODE (t1) != TRANSLATION_UNIT_DECL)
1214     switch (TREE_CODE_CLASS (TREE_CODE (t1)))
1215       {
1216       case tcc_declaration:
1217         t1 = DECL_CONTEXT (t1); break;
1218       case tcc_type:
1219         t1 = TYPE_CONTEXT (t1); break;
1220       case tcc_exceptional:
1221         t1 = BLOCK_SUPERCONTEXT (t1); break;  /* assume block */
1222       default: gcc_unreachable ();
1223       }
1224
1225   while (t2 && TREE_CODE (t2) != TRANSLATION_UNIT_DECL)
1226     switch (TREE_CODE_CLASS (TREE_CODE (t2)))
1227       {
1228       case tcc_declaration:
1229         t2 = DECL_CONTEXT (t2); break;
1230       case tcc_type:
1231         t2 = TYPE_CONTEXT (t2); break;
1232       case tcc_exceptional:
1233         t2 = BLOCK_SUPERCONTEXT (t2); break;  /* assume block */
1234       default: gcc_unreachable ();
1235       }
1236
1237   return t1 == t2;
1238 }
1239
1240 /* Allocate the seen two types, assuming that they are compatible. */
1241
1242 static struct tagged_tu_seen_cache *
1243 alloc_tagged_tu_seen_cache (const_tree t1, const_tree t2)
1244 {
1245   struct tagged_tu_seen_cache *tu = XNEW (struct tagged_tu_seen_cache);
1246   tu->next = tagged_tu_seen_base;
1247   tu->t1 = t1;
1248   tu->t2 = t2;
1249
1250   tagged_tu_seen_base = tu;
1251
1252   /* The C standard says that two structures in different translation
1253      units are compatible with each other only if the types of their
1254      fields are compatible (among other things).  We assume that they
1255      are compatible until proven otherwise when building the cache.
1256      An example where this can occur is:
1257      struct a
1258      {
1259        struct a *next;
1260      };
1261      If we are comparing this against a similar struct in another TU,
1262      and did not assume they were compatible, we end up with an infinite
1263      loop.  */
1264   tu->val = 1;
1265   return tu;
1266 }
1267
1268 /* Free the seen types until we get to TU_TIL. */
1269
1270 static void
1271 free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *tu_til)
1272 {
1273   const struct tagged_tu_seen_cache *tu = tagged_tu_seen_base;
1274   while (tu != tu_til)
1275     {
1276       const struct tagged_tu_seen_cache *const tu1
1277         = (const struct tagged_tu_seen_cache *) tu;
1278       tu = tu1->next;
1279       free (CONST_CAST (struct tagged_tu_seen_cache *, tu1));
1280     }
1281   tagged_tu_seen_base = tu_til;
1282 }
1283
1284 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
1285    compatible.  If the two types are not the same (which has been
1286    checked earlier), this can only happen when multiple translation
1287    units are being compiled.  See C99 6.2.7 paragraph 1 for the exact
1288    rules.  ENUM_AND_INT_P is as in comptypes_internal.  */
1289
1290 static int
1291 tagged_types_tu_compatible_p (const_tree t1, const_tree t2,
1292                               bool *enum_and_int_p)
1293 {
1294   tree s1, s2;
1295   bool needs_warning = false;
1296
1297   /* We have to verify that the tags of the types are the same.  This
1298      is harder than it looks because this may be a typedef, so we have
1299      to go look at the original type.  It may even be a typedef of a
1300      typedef...
1301      In the case of compiler-created builtin structs the TYPE_DECL
1302      may be a dummy, with no DECL_ORIGINAL_TYPE.  Don't fault.  */
1303   while (TYPE_NAME (t1)
1304          && TREE_CODE (TYPE_NAME (t1)) == TYPE_DECL
1305          && DECL_ORIGINAL_TYPE (TYPE_NAME (t1)))
1306     t1 = DECL_ORIGINAL_TYPE (TYPE_NAME (t1));
1307
1308   while (TYPE_NAME (t2)
1309          && TREE_CODE (TYPE_NAME (t2)) == TYPE_DECL
1310          && DECL_ORIGINAL_TYPE (TYPE_NAME (t2)))
1311     t2 = DECL_ORIGINAL_TYPE (TYPE_NAME (t2));
1312
1313   /* C90 didn't have the requirement that the two tags be the same.  */
1314   if (flag_isoc99 && TYPE_NAME (t1) != TYPE_NAME (t2))
1315     return 0;
1316
1317   /* C90 didn't say what happened if one or both of the types were
1318      incomplete; we choose to follow C99 rules here, which is that they
1319      are compatible.  */
1320   if (TYPE_SIZE (t1) == NULL
1321       || TYPE_SIZE (t2) == NULL)
1322     return 1;
1323
1324   {
1325     const struct tagged_tu_seen_cache * tts_i;
1326     for (tts_i = tagged_tu_seen_base; tts_i != NULL; tts_i = tts_i->next)
1327       if (tts_i->t1 == t1 && tts_i->t2 == t2)
1328         return tts_i->val;
1329   }
1330
1331   switch (TREE_CODE (t1))
1332     {
1333     case ENUMERAL_TYPE:
1334       {
1335         struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1336         /* Speed up the case where the type values are in the same order.  */
1337         tree tv1 = TYPE_VALUES (t1);
1338         tree tv2 = TYPE_VALUES (t2);
1339
1340         if (tv1 == tv2)
1341           {
1342             return 1;
1343           }
1344
1345         for (;tv1 && tv2; tv1 = TREE_CHAIN (tv1), tv2 = TREE_CHAIN (tv2))
1346           {
1347             if (TREE_PURPOSE (tv1) != TREE_PURPOSE (tv2))
1348               break;
1349             if (simple_cst_equal (TREE_VALUE (tv1), TREE_VALUE (tv2)) != 1)
1350               {
1351                 tu->val = 0;
1352                 return 0;
1353               }
1354           }
1355
1356         if (tv1 == NULL_TREE && tv2 == NULL_TREE)
1357           {
1358             return 1;
1359           }
1360         if (tv1 == NULL_TREE || tv2 == NULL_TREE)
1361           {
1362             tu->val = 0;
1363             return 0;
1364           }
1365
1366         if (list_length (TYPE_VALUES (t1)) != list_length (TYPE_VALUES (t2)))
1367           {
1368             tu->val = 0;
1369             return 0;
1370           }
1371
1372         for (s1 = TYPE_VALUES (t1); s1; s1 = TREE_CHAIN (s1))
1373           {
1374             s2 = purpose_member (TREE_PURPOSE (s1), TYPE_VALUES (t2));
1375             if (s2 == NULL
1376                 || simple_cst_equal (TREE_VALUE (s1), TREE_VALUE (s2)) != 1)
1377               {
1378                 tu->val = 0;
1379                 return 0;
1380               }
1381           }
1382         return 1;
1383       }
1384
1385     case UNION_TYPE:
1386       {
1387         struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1388         if (list_length (TYPE_FIELDS (t1)) != list_length (TYPE_FIELDS (t2)))
1389           {
1390             tu->val = 0;
1391             return 0;
1392           }
1393
1394         /*  Speed up the common case where the fields are in the same order. */
1395         for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2); s1 && s2;
1396              s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2))
1397           {
1398             int result;
1399
1400             if (DECL_NAME (s1) != DECL_NAME (s2))
1401               break;
1402             result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2),
1403                                          enum_and_int_p);
1404
1405             if (result != 1 && !DECL_NAME (s1))
1406               break;
1407             if (result == 0)
1408               {
1409                 tu->val = 0;
1410                 return 0;
1411               }
1412             if (result == 2)
1413               needs_warning = true;
1414
1415             if (TREE_CODE (s1) == FIELD_DECL
1416                 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1417                                      DECL_FIELD_BIT_OFFSET (s2)) != 1)
1418               {
1419                 tu->val = 0;
1420                 return 0;
1421               }
1422           }
1423         if (!s1 && !s2)
1424           {
1425             tu->val = needs_warning ? 2 : 1;
1426             return tu->val;
1427           }
1428
1429         for (s1 = TYPE_FIELDS (t1); s1; s1 = TREE_CHAIN (s1))
1430           {
1431             bool ok = false;
1432
1433             for (s2 = TYPE_FIELDS (t2); s2; s2 = TREE_CHAIN (s2))
1434               if (DECL_NAME (s1) == DECL_NAME (s2))
1435                 {
1436                   int result;
1437
1438                   result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2),
1439                                                enum_and_int_p);
1440
1441                   if (result != 1 && !DECL_NAME (s1))
1442                     continue;
1443                   if (result == 0)
1444                     {
1445                       tu->val = 0;
1446                       return 0;
1447                     }
1448                   if (result == 2)
1449                     needs_warning = true;
1450
1451                   if (TREE_CODE (s1) == FIELD_DECL
1452                       && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1453                                            DECL_FIELD_BIT_OFFSET (s2)) != 1)
1454                     break;
1455
1456                   ok = true;
1457                   break;
1458                 }
1459             if (!ok)
1460               {
1461                 tu->val = 0;
1462                 return 0;
1463               }
1464           }
1465         tu->val = needs_warning ? 2 : 10;
1466         return tu->val;
1467       }
1468
1469     case RECORD_TYPE:
1470       {
1471         struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1472
1473         for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2);
1474              s1 && s2;
1475              s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2))
1476           {
1477             int result;
1478             if (TREE_CODE (s1) != TREE_CODE (s2)
1479                 || DECL_NAME (s1) != DECL_NAME (s2))
1480               break;
1481             result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2),
1482                                          enum_and_int_p);
1483             if (result == 0)
1484               break;
1485             if (result == 2)
1486               needs_warning = true;
1487
1488             if (TREE_CODE (s1) == FIELD_DECL
1489                 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1490                                      DECL_FIELD_BIT_OFFSET (s2)) != 1)
1491               break;
1492           }
1493         if (s1 && s2)
1494           tu->val = 0;
1495         else
1496           tu->val = needs_warning ? 2 : 1;
1497         return tu->val;
1498       }
1499
1500     default:
1501       gcc_unreachable ();
1502     }
1503 }
1504
1505 /* Return 1 if two function types F1 and F2 are compatible.
1506    If either type specifies no argument types,
1507    the other must specify a fixed number of self-promoting arg types.
1508    Otherwise, if one type specifies only the number of arguments,
1509    the other must specify that number of self-promoting arg types.
1510    Otherwise, the argument types must match.
1511    ENUM_AND_INT_P is as in comptypes_internal.  */
1512
1513 static int
1514 function_types_compatible_p (const_tree f1, const_tree f2,
1515                              bool *enum_and_int_p)
1516 {
1517   tree args1, args2;
1518   /* 1 if no need for warning yet, 2 if warning cause has been seen.  */
1519   int val = 1;
1520   int val1;
1521   tree ret1, ret2;
1522
1523   ret1 = TREE_TYPE (f1);
1524   ret2 = TREE_TYPE (f2);
1525
1526   /* 'volatile' qualifiers on a function's return type used to mean
1527      the function is noreturn.  */
1528   if (TYPE_VOLATILE (ret1) != TYPE_VOLATILE (ret2))
1529     pedwarn (input_location, 0, "function return types not compatible due to %<volatile%>");
1530   if (TYPE_VOLATILE (ret1))
1531     ret1 = build_qualified_type (TYPE_MAIN_VARIANT (ret1),
1532                                  TYPE_QUALS (ret1) & ~TYPE_QUAL_VOLATILE);
1533   if (TYPE_VOLATILE (ret2))
1534     ret2 = build_qualified_type (TYPE_MAIN_VARIANT (ret2),
1535                                  TYPE_QUALS (ret2) & ~TYPE_QUAL_VOLATILE);
1536   val = comptypes_internal (ret1, ret2, enum_and_int_p);
1537   if (val == 0)
1538     return 0;
1539
1540   args1 = TYPE_ARG_TYPES (f1);
1541   args2 = TYPE_ARG_TYPES (f2);
1542
1543   /* An unspecified parmlist matches any specified parmlist
1544      whose argument types don't need default promotions.  */
1545
1546   if (args1 == 0)
1547     {
1548       if (!self_promoting_args_p (args2))
1549         return 0;
1550       /* If one of these types comes from a non-prototype fn definition,
1551          compare that with the other type's arglist.
1552          If they don't match, ask for a warning (but no error).  */
1553       if (TYPE_ACTUAL_ARG_TYPES (f1)
1554           && 1 != type_lists_compatible_p (args2, TYPE_ACTUAL_ARG_TYPES (f1),
1555                                            enum_and_int_p))
1556         val = 2;
1557       return val;
1558     }
1559   if (args2 == 0)
1560     {
1561       if (!self_promoting_args_p (args1))
1562         return 0;
1563       if (TYPE_ACTUAL_ARG_TYPES (f2)
1564           && 1 != type_lists_compatible_p (args1, TYPE_ACTUAL_ARG_TYPES (f2),
1565                                            enum_and_int_p))
1566         val = 2;
1567       return val;
1568     }
1569
1570   /* Both types have argument lists: compare them and propagate results.  */
1571   val1 = type_lists_compatible_p (args1, args2, enum_and_int_p);
1572   return val1 != 1 ? val1 : val;
1573 }
1574
1575 /* Check two lists of types for compatibility, returning 0 for
1576    incompatible, 1 for compatible, or 2 for compatible with
1577    warning.  ENUM_AND_INT_P is as in comptypes_internal.  */
1578
1579 static int
1580 type_lists_compatible_p (const_tree args1, const_tree args2,
1581                          bool *enum_and_int_p)
1582 {
1583   /* 1 if no need for warning yet, 2 if warning cause has been seen.  */
1584   int val = 1;
1585   int newval = 0;
1586
1587   while (1)
1588     {
1589       tree a1, mv1, a2, mv2;
1590       if (args1 == 0 && args2 == 0)
1591         return val;
1592       /* If one list is shorter than the other,
1593          they fail to match.  */
1594       if (args1 == 0 || args2 == 0)
1595         return 0;
1596       mv1 = a1 = TREE_VALUE (args1);
1597       mv2 = a2 = TREE_VALUE (args2);
1598       if (mv1 && mv1 != error_mark_node && TREE_CODE (mv1) != ARRAY_TYPE)
1599         mv1 = TYPE_MAIN_VARIANT (mv1);
1600       if (mv2 && mv2 != error_mark_node && TREE_CODE (mv2) != ARRAY_TYPE)
1601         mv2 = TYPE_MAIN_VARIANT (mv2);
1602       /* A null pointer instead of a type
1603          means there is supposed to be an argument
1604          but nothing is specified about what type it has.
1605          So match anything that self-promotes.  */
1606       if (a1 == 0)
1607         {
1608           if (c_type_promotes_to (a2) != a2)
1609             return 0;
1610         }
1611       else if (a2 == 0)
1612         {
1613           if (c_type_promotes_to (a1) != a1)
1614             return 0;
1615         }
1616       /* If one of the lists has an error marker, ignore this arg.  */
1617       else if (TREE_CODE (a1) == ERROR_MARK
1618                || TREE_CODE (a2) == ERROR_MARK)
1619         ;
1620       else if (!(newval = comptypes_internal (mv1, mv2, enum_and_int_p)))
1621         {
1622           /* Allow  wait (union {union wait *u; int *i} *)
1623              and  wait (union wait *)  to be compatible.  */
1624           if (TREE_CODE (a1) == UNION_TYPE
1625               && (TYPE_NAME (a1) == 0
1626                   || TYPE_TRANSPARENT_AGGR (a1))
1627               && TREE_CODE (TYPE_SIZE (a1)) == INTEGER_CST
1628               && tree_int_cst_equal (TYPE_SIZE (a1),
1629                                      TYPE_SIZE (a2)))
1630             {
1631               tree memb;
1632               for (memb = TYPE_FIELDS (a1);
1633                    memb; memb = TREE_CHAIN (memb))
1634                 {
1635                   tree mv3 = TREE_TYPE (memb);
1636                   if (mv3 && mv3 != error_mark_node
1637                       && TREE_CODE (mv3) != ARRAY_TYPE)
1638                     mv3 = TYPE_MAIN_VARIANT (mv3);
1639                   if (comptypes_internal (mv3, mv2, enum_and_int_p))
1640                     break;
1641                 }
1642               if (memb == 0)
1643                 return 0;
1644             }
1645           else if (TREE_CODE (a2) == UNION_TYPE
1646                    && (TYPE_NAME (a2) == 0
1647                        || TYPE_TRANSPARENT_AGGR (a2))
1648                    && TREE_CODE (TYPE_SIZE (a2)) == INTEGER_CST
1649                    && tree_int_cst_equal (TYPE_SIZE (a2),
1650                                           TYPE_SIZE (a1)))
1651             {
1652               tree memb;
1653               for (memb = TYPE_FIELDS (a2);
1654                    memb; memb = TREE_CHAIN (memb))
1655                 {
1656                   tree mv3 = TREE_TYPE (memb);
1657                   if (mv3 && mv3 != error_mark_node
1658                       && TREE_CODE (mv3) != ARRAY_TYPE)
1659                     mv3 = TYPE_MAIN_VARIANT (mv3);
1660                   if (comptypes_internal (mv3, mv1, enum_and_int_p))
1661                     break;
1662                 }
1663               if (memb == 0)
1664                 return 0;
1665             }
1666           else
1667             return 0;
1668         }
1669
1670       /* comptypes said ok, but record if it said to warn.  */
1671       if (newval > val)
1672         val = newval;
1673
1674       args1 = TREE_CHAIN (args1);
1675       args2 = TREE_CHAIN (args2);
1676     }
1677 }
1678 \f
1679 /* Compute the size to increment a pointer by.  */
1680
1681 static tree
1682 c_size_in_bytes (const_tree type)
1683 {
1684   enum tree_code code = TREE_CODE (type);
1685
1686   if (code == FUNCTION_TYPE || code == VOID_TYPE || code == ERROR_MARK)
1687     return size_one_node;
1688
1689   if (!COMPLETE_OR_VOID_TYPE_P (type))
1690     {
1691       error ("arithmetic on pointer to an incomplete type");
1692       return size_one_node;
1693     }
1694
1695   /* Convert in case a char is more than one unit.  */
1696   return size_binop_loc (input_location, CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
1697                          size_int (TYPE_PRECISION (char_type_node)
1698                                    / BITS_PER_UNIT));
1699 }
1700 \f
1701 /* Return either DECL or its known constant value (if it has one).  */
1702
1703 tree
1704 decl_constant_value (tree decl)
1705 {
1706   if (/* Don't change a variable array bound or initial value to a constant
1707          in a place where a variable is invalid.  Note that DECL_INITIAL
1708          isn't valid for a PARM_DECL.  */
1709       current_function_decl != 0
1710       && TREE_CODE (decl) != PARM_DECL
1711       && !TREE_THIS_VOLATILE (decl)
1712       && TREE_READONLY (decl)
1713       && DECL_INITIAL (decl) != 0
1714       && TREE_CODE (DECL_INITIAL (decl)) != ERROR_MARK
1715       /* This is invalid if initial value is not constant.
1716          If it has either a function call, a memory reference,
1717          or a variable, then re-evaluating it could give different results.  */
1718       && TREE_CONSTANT (DECL_INITIAL (decl))
1719       /* Check for cases where this is sub-optimal, even though valid.  */
1720       && TREE_CODE (DECL_INITIAL (decl)) != CONSTRUCTOR)
1721     return DECL_INITIAL (decl);
1722   return decl;
1723 }
1724
1725 /* Convert the array expression EXP to a pointer.  */
1726 static tree
1727 array_to_pointer_conversion (location_t loc, tree exp)
1728 {
1729   tree orig_exp = exp;
1730   tree type = TREE_TYPE (exp);
1731   tree adr;
1732   tree restype = TREE_TYPE (type);
1733   tree ptrtype;
1734
1735   gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
1736
1737   STRIP_TYPE_NOPS (exp);
1738
1739   if (TREE_NO_WARNING (orig_exp))
1740     TREE_NO_WARNING (exp) = 1;
1741
1742   ptrtype = build_pointer_type (restype);
1743
1744   if (TREE_CODE (exp) == INDIRECT_REF)
1745     return convert (ptrtype, TREE_OPERAND (exp, 0));
1746
1747   adr = build_unary_op (loc, ADDR_EXPR, exp, 1);
1748   return convert (ptrtype, adr);
1749 }
1750
1751 /* Convert the function expression EXP to a pointer.  */
1752 static tree
1753 function_to_pointer_conversion (location_t loc, tree exp)
1754 {
1755   tree orig_exp = exp;
1756
1757   gcc_assert (TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE);
1758
1759   STRIP_TYPE_NOPS (exp);
1760
1761   if (TREE_NO_WARNING (orig_exp))
1762     TREE_NO_WARNING (exp) = 1;
1763
1764   return build_unary_op (loc, ADDR_EXPR, exp, 0);
1765 }
1766
1767 /* Mark EXP as read, not just set, for set but not used -Wunused
1768    warning purposes.  */
1769
1770 void
1771 mark_exp_read (tree exp)
1772 {
1773   switch (TREE_CODE (exp))
1774     {
1775     case VAR_DECL:
1776     case PARM_DECL:
1777       DECL_READ_P (exp) = 1;
1778       break;
1779     case ARRAY_REF:
1780     case COMPONENT_REF:
1781     case MODIFY_EXPR:
1782     case REALPART_EXPR:
1783     case IMAGPART_EXPR:
1784     CASE_CONVERT:
1785     case ADDR_EXPR:
1786       mark_exp_read (TREE_OPERAND (exp, 0));
1787       break;
1788     case COMPOUND_EXPR:
1789       mark_exp_read (TREE_OPERAND (exp, 1));
1790       break;
1791     default:
1792       break;
1793     }
1794 }
1795
1796 /* Perform the default conversion of arrays and functions to pointers.
1797    Return the result of converting EXP.  For any other expression, just
1798    return EXP.
1799
1800    LOC is the location of the expression.  */
1801
1802 struct c_expr
1803 default_function_array_conversion (location_t loc, struct c_expr exp)
1804 {
1805   tree orig_exp = exp.value;
1806   tree type = TREE_TYPE (exp.value);
1807   enum tree_code code = TREE_CODE (type);
1808
1809   switch (code)
1810     {
1811     case ARRAY_TYPE:
1812       {
1813         bool not_lvalue = false;
1814         bool lvalue_array_p;
1815
1816         while ((TREE_CODE (exp.value) == NON_LVALUE_EXPR
1817                 || CONVERT_EXPR_P (exp.value))
1818                && TREE_TYPE (TREE_OPERAND (exp.value, 0)) == type)
1819           {
1820             if (TREE_CODE (exp.value) == NON_LVALUE_EXPR)
1821               not_lvalue = true;
1822             exp.value = TREE_OPERAND (exp.value, 0);
1823           }
1824
1825         if (TREE_NO_WARNING (orig_exp))
1826           TREE_NO_WARNING (exp.value) = 1;
1827
1828         lvalue_array_p = !not_lvalue && lvalue_p (exp.value);
1829         if (!flag_isoc99 && !lvalue_array_p)
1830           {
1831             /* Before C99, non-lvalue arrays do not decay to pointers.
1832                Normally, using such an array would be invalid; but it can
1833                be used correctly inside sizeof or as a statement expression.
1834                Thus, do not give an error here; an error will result later.  */
1835             return exp;
1836           }
1837
1838         exp.value = array_to_pointer_conversion (loc, exp.value);
1839       }
1840       break;
1841     case FUNCTION_TYPE:
1842       exp.value = function_to_pointer_conversion (loc, exp.value);
1843       break;
1844     default:
1845       break;
1846     }
1847
1848   return exp;
1849 }
1850
1851 struct c_expr
1852 default_function_array_read_conversion (location_t loc, struct c_expr exp)
1853 {
1854   mark_exp_read (exp.value);
1855   return default_function_array_conversion (loc, exp);
1856 }
1857
1858 /* EXP is an expression of integer type.  Apply the integer promotions
1859    to it and return the promoted value.  */
1860
1861 tree
1862 perform_integral_promotions (tree exp)
1863 {
1864   tree type = TREE_TYPE (exp);
1865   enum tree_code code = TREE_CODE (type);
1866
1867   gcc_assert (INTEGRAL_TYPE_P (type));
1868
1869   /* Normally convert enums to int,
1870      but convert wide enums to something wider.  */
1871   if (code == ENUMERAL_TYPE)
1872     {
1873       type = c_common_type_for_size (MAX (TYPE_PRECISION (type),
1874                                           TYPE_PRECISION (integer_type_node)),
1875                                      ((TYPE_PRECISION (type)
1876                                        >= TYPE_PRECISION (integer_type_node))
1877                                       && TYPE_UNSIGNED (type)));
1878
1879       return convert (type, exp);
1880     }
1881
1882   /* ??? This should no longer be needed now bit-fields have their
1883      proper types.  */
1884   if (TREE_CODE (exp) == COMPONENT_REF
1885       && DECL_C_BIT_FIELD (TREE_OPERAND (exp, 1))
1886       /* If it's thinner than an int, promote it like a
1887          c_promoting_integer_type_p, otherwise leave it alone.  */
1888       && 0 > compare_tree_int (DECL_SIZE (TREE_OPERAND (exp, 1)),
1889                                TYPE_PRECISION (integer_type_node)))
1890     return convert (integer_type_node, exp);
1891
1892   if (c_promoting_integer_type_p (type))
1893     {
1894       /* Preserve unsignedness if not really getting any wider.  */
1895       if (TYPE_UNSIGNED (type)
1896           && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))
1897         return convert (unsigned_type_node, exp);
1898
1899       return convert (integer_type_node, exp);
1900     }
1901
1902   return exp;
1903 }
1904
1905
1906 /* Perform default promotions for C data used in expressions.
1907    Enumeral types or short or char are converted to int.
1908    In addition, manifest constants symbols are replaced by their values.  */
1909
1910 tree
1911 default_conversion (tree exp)
1912 {
1913   tree orig_exp;
1914   tree type = TREE_TYPE (exp);
1915   enum tree_code code = TREE_CODE (type);
1916   tree promoted_type;
1917
1918   mark_exp_read (exp);
1919
1920   /* Functions and arrays have been converted during parsing.  */
1921   gcc_assert (code != FUNCTION_TYPE);
1922   if (code == ARRAY_TYPE)
1923     return exp;
1924
1925   /* Constants can be used directly unless they're not loadable.  */
1926   if (TREE_CODE (exp) == CONST_DECL)
1927     exp = DECL_INITIAL (exp);
1928
1929   /* Strip no-op conversions.  */
1930   orig_exp = exp;
1931   STRIP_TYPE_NOPS (exp);
1932
1933   if (TREE_NO_WARNING (orig_exp))
1934     TREE_NO_WARNING (exp) = 1;
1935
1936   if (code == VOID_TYPE)
1937     {
1938       error ("void value not ignored as it ought to be");
1939       return error_mark_node;
1940     }
1941
1942   exp = require_complete_type (exp);
1943   if (exp == error_mark_node)
1944     return error_mark_node;
1945
1946   promoted_type = targetm.promoted_type (type);
1947   if (promoted_type)
1948     return convert (promoted_type, exp);
1949
1950   if (INTEGRAL_TYPE_P (type))
1951     return perform_integral_promotions (exp);
1952
1953   return exp;
1954 }
1955 \f
1956 /* Look up COMPONENT in a structure or union TYPE.
1957
1958    If the component name is not found, returns NULL_TREE.  Otherwise,
1959    the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1960    stepping down the chain to the component, which is in the last
1961    TREE_VALUE of the list.  Normally the list is of length one, but if
1962    the component is embedded within (nested) anonymous structures or
1963    unions, the list steps down the chain to the component.  */
1964
1965 static tree
1966 lookup_field (tree type, tree component)
1967 {
1968   tree field;
1969
1970   /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1971      to the field elements.  Use a binary search on this array to quickly
1972      find the element.  Otherwise, do a linear search.  TYPE_LANG_SPECIFIC
1973      will always be set for structures which have many elements.  */
1974
1975   if (TYPE_LANG_SPECIFIC (type) && TYPE_LANG_SPECIFIC (type)->s)
1976     {
1977       int bot, top, half;
1978       tree *field_array = &TYPE_LANG_SPECIFIC (type)->s->elts[0];
1979
1980       field = TYPE_FIELDS (type);
1981       bot = 0;
1982       top = TYPE_LANG_SPECIFIC (type)->s->len;
1983       while (top - bot > 1)
1984         {
1985           half = (top - bot + 1) >> 1;
1986           field = field_array[bot+half];
1987
1988           if (DECL_NAME (field) == NULL_TREE)
1989             {
1990               /* Step through all anon unions in linear fashion.  */
1991               while (DECL_NAME (field_array[bot]) == NULL_TREE)
1992                 {
1993                   field = field_array[bot++];
1994                   if (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1995                       || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)
1996                     {
1997                       tree anon = lookup_field (TREE_TYPE (field), component);
1998
1999                       if (anon)
2000                         return tree_cons (NULL_TREE, field, anon);
2001                     }
2002                 }
2003
2004               /* Entire record is only anon unions.  */
2005               if (bot > top)
2006                 return NULL_TREE;
2007
2008               /* Restart the binary search, with new lower bound.  */
2009               continue;
2010             }
2011
2012           if (DECL_NAME (field) == component)
2013             break;
2014           if (DECL_NAME (field) < component)
2015             bot += half;
2016           else
2017             top = bot + half;
2018         }
2019
2020       if (DECL_NAME (field_array[bot]) == component)
2021         field = field_array[bot];
2022       else if (DECL_NAME (field) != component)
2023         return NULL_TREE;
2024     }
2025   else
2026     {
2027       for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
2028         {
2029           if (DECL_NAME (field) == NULL_TREE
2030               && (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
2031                   || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE))
2032             {
2033               tree anon = lookup_field (TREE_TYPE (field), component);
2034
2035               if (anon)
2036                 return tree_cons (NULL_TREE, field, anon);
2037             }
2038
2039           if (DECL_NAME (field) == component)
2040             break;
2041         }
2042
2043       if (field == NULL_TREE)
2044         return NULL_TREE;
2045     }
2046
2047   return tree_cons (NULL_TREE, field, NULL_TREE);
2048 }
2049
2050 /* Make an expression to refer to the COMPONENT field of structure or
2051    union value DATUM.  COMPONENT is an IDENTIFIER_NODE.  LOC is the
2052    location of the COMPONENT_REF.  */
2053
2054 tree
2055 build_component_ref (location_t loc, tree datum, tree component)
2056 {
2057   tree type = TREE_TYPE (datum);
2058   enum tree_code code = TREE_CODE (type);
2059   tree field = NULL;
2060   tree ref;
2061   bool datum_lvalue = lvalue_p (datum);
2062
2063   if (!objc_is_public (datum, component))
2064     return error_mark_node;
2065
2066   /* See if there is a field or component with name COMPONENT.  */
2067
2068   if (code == RECORD_TYPE || code == UNION_TYPE)
2069     {
2070       if (!COMPLETE_TYPE_P (type))
2071         {
2072           c_incomplete_type_error (NULL_TREE, type);
2073           return error_mark_node;
2074         }
2075
2076       field = lookup_field (type, component);
2077
2078       if (!field)
2079         {
2080           error_at (loc, "%qT has no member named %qE", type, component);
2081           return error_mark_node;
2082         }
2083
2084       /* Chain the COMPONENT_REFs if necessary down to the FIELD.
2085          This might be better solved in future the way the C++ front
2086          end does it - by giving the anonymous entities each a
2087          separate name and type, and then have build_component_ref
2088          recursively call itself.  We can't do that here.  */
2089       do
2090         {
2091           tree subdatum = TREE_VALUE (field);
2092           int quals;
2093           tree subtype;
2094           bool use_datum_quals;
2095
2096           if (TREE_TYPE (subdatum) == error_mark_node)
2097             return error_mark_node;
2098
2099           /* If this is an rvalue, it does not have qualifiers in C
2100              standard terms and we must avoid propagating such
2101              qualifiers down to a non-lvalue array that is then
2102              converted to a pointer.  */
2103           use_datum_quals = (datum_lvalue
2104                              || TREE_CODE (TREE_TYPE (subdatum)) != ARRAY_TYPE);
2105
2106           quals = TYPE_QUALS (strip_array_types (TREE_TYPE (subdatum)));
2107           if (use_datum_quals)
2108             quals |= TYPE_QUALS (TREE_TYPE (datum));
2109           subtype = c_build_qualified_type (TREE_TYPE (subdatum), quals);
2110
2111           ref = build3 (COMPONENT_REF, subtype, datum, subdatum,
2112                         NULL_TREE);
2113           SET_EXPR_LOCATION (ref, loc);
2114           if (TREE_READONLY (subdatum)
2115               || (use_datum_quals && TREE_READONLY (datum)))
2116             TREE_READONLY (ref) = 1;
2117           if (TREE_THIS_VOLATILE (subdatum)
2118               || (use_datum_quals && TREE_THIS_VOLATILE (datum)))
2119             TREE_THIS_VOLATILE (ref) = 1;
2120
2121           if (TREE_DEPRECATED (subdatum))
2122             warn_deprecated_use (subdatum, NULL_TREE);
2123
2124           datum = ref;
2125
2126           field = TREE_CHAIN (field);
2127         }
2128       while (field);
2129
2130       return ref;
2131     }
2132   else if (code != ERROR_MARK)
2133     error_at (loc,
2134               "request for member %qE in something not a structure or union",
2135               component);
2136
2137   return error_mark_node;
2138 }
2139 \f
2140 /* Given an expression PTR for a pointer, return an expression
2141    for the value pointed to.
2142    ERRORSTRING is the name of the operator to appear in error messages.
2143
2144    LOC is the location to use for the generated tree.  */
2145
2146 tree
2147 build_indirect_ref (location_t loc, tree ptr, ref_operator errstring)
2148 {
2149   tree pointer = default_conversion (ptr);
2150   tree type = TREE_TYPE (pointer);
2151   tree ref;
2152
2153   if (TREE_CODE (type) == POINTER_TYPE)
2154     {
2155       if (CONVERT_EXPR_P (pointer)
2156           || TREE_CODE (pointer) == VIEW_CONVERT_EXPR)
2157         {
2158           /* If a warning is issued, mark it to avoid duplicates from
2159              the backend.  This only needs to be done at
2160              warn_strict_aliasing > 2.  */
2161           if (warn_strict_aliasing > 2)
2162             if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (pointer, 0)),
2163                                          type, TREE_OPERAND (pointer, 0)))
2164               TREE_NO_WARNING (pointer) = 1;
2165         }
2166
2167       if (TREE_CODE (pointer) == ADDR_EXPR
2168           && (TREE_TYPE (TREE_OPERAND (pointer, 0))
2169               == TREE_TYPE (type)))
2170         {
2171           ref = TREE_OPERAND (pointer, 0);
2172           protected_set_expr_location (ref, loc);
2173           return ref;
2174         }
2175       else
2176         {
2177           tree t = TREE_TYPE (type);
2178
2179           ref = build1 (INDIRECT_REF, t, pointer);
2180
2181           if (!COMPLETE_OR_VOID_TYPE_P (t) && TREE_CODE (t) != ARRAY_TYPE)
2182             {
2183               error_at (loc, "dereferencing pointer to incomplete type");
2184               return error_mark_node;
2185             }
2186           if (VOID_TYPE_P (t) && c_inhibit_evaluation_warnings == 0)
2187             warning_at (loc, 0, "dereferencing %<void *%> pointer");
2188
2189           /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2190              so that we get the proper error message if the result is used
2191              to assign to.  Also, &* is supposed to be a no-op.
2192              And ANSI C seems to specify that the type of the result
2193              should be the const type.  */
2194           /* A de-reference of a pointer to const is not a const.  It is valid
2195              to change it via some other pointer.  */
2196           TREE_READONLY (ref) = TYPE_READONLY (t);
2197           TREE_SIDE_EFFECTS (ref)
2198             = TYPE_VOLATILE (t) || TREE_SIDE_EFFECTS (pointer);
2199           TREE_THIS_VOLATILE (ref) = TYPE_VOLATILE (t);
2200           protected_set_expr_location (ref, loc);
2201           return ref;
2202         }
2203     }
2204   else if (TREE_CODE (pointer) != ERROR_MARK)
2205     switch (errstring)
2206       {
2207          case RO_ARRAY_INDEXING:
2208            error_at (loc,
2209                      "invalid type argument of array indexing (have %qT)",
2210                      type);
2211            break;
2212          case RO_UNARY_STAR:
2213            error_at (loc,
2214                      "invalid type argument of unary %<*%> (have %qT)",
2215                      type);
2216            break;
2217          case RO_ARROW:
2218            error_at (loc,
2219                      "invalid type argument of %<->%> (have %qT)",
2220                      type);
2221            break;
2222          default:
2223            gcc_unreachable ();
2224       }
2225   return error_mark_node;
2226 }
2227
2228 /* This handles expressions of the form "a[i]", which denotes
2229    an array reference.
2230
2231    This is logically equivalent in C to *(a+i), but we may do it differently.
2232    If A is a variable or a member, we generate a primitive ARRAY_REF.
2233    This avoids forcing the array out of registers, and can work on
2234    arrays that are not lvalues (for example, members of structures returned
2235    by functions).
2236
2237    LOC is the location to use for the returned expression.  */
2238
2239 tree
2240 build_array_ref (location_t loc, tree array, tree index)
2241 {
2242   tree ret;
2243   bool swapped = false;
2244   if (TREE_TYPE (array) == error_mark_node
2245       || TREE_TYPE (index) == error_mark_node)
2246     return error_mark_node;
2247
2248   if (TREE_CODE (TREE_TYPE (array)) != ARRAY_TYPE
2249       && TREE_CODE (TREE_TYPE (array)) != POINTER_TYPE)
2250     {
2251       tree temp;
2252       if (TREE_CODE (TREE_TYPE (index)) != ARRAY_TYPE
2253           && TREE_CODE (TREE_TYPE (index)) != POINTER_TYPE)
2254         {
2255           error_at (loc, "subscripted value is neither array nor pointer");
2256           return error_mark_node;
2257         }
2258       temp = array;
2259       array = index;
2260       index = temp;
2261       swapped = true;
2262     }
2263
2264   if (!INTEGRAL_TYPE_P (TREE_TYPE (index)))
2265     {
2266       error_at (loc, "array subscript is not an integer");
2267       return error_mark_node;
2268     }
2269
2270   if (TREE_CODE (TREE_TYPE (TREE_TYPE (array))) == FUNCTION_TYPE)
2271     {
2272       error_at (loc, "subscripted value is pointer to function");
2273       return error_mark_node;
2274     }
2275
2276   /* ??? Existing practice has been to warn only when the char
2277      index is syntactically the index, not for char[array].  */
2278   if (!swapped)
2279      warn_array_subscript_with_type_char (index);
2280
2281   /* Apply default promotions *after* noticing character types.  */
2282   index = default_conversion (index);
2283
2284   gcc_assert (TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE);
2285
2286   if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2287     {
2288       tree rval, type;
2289
2290       /* An array that is indexed by a non-constant
2291          cannot be stored in a register; we must be able to do
2292          address arithmetic on its address.
2293          Likewise an array of elements of variable size.  */
2294       if (TREE_CODE (index) != INTEGER_CST
2295           || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2296               && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) != INTEGER_CST))
2297         {
2298           if (!c_mark_addressable (array))
2299             return error_mark_node;
2300         }
2301       /* An array that is indexed by a constant value which is not within
2302          the array bounds cannot be stored in a register either; because we
2303          would get a crash in store_bit_field/extract_bit_field when trying
2304          to access a non-existent part of the register.  */
2305       if (TREE_CODE (index) == INTEGER_CST
2306           && TYPE_DOMAIN (TREE_TYPE (array))
2307           && !int_fits_type_p (index, TYPE_DOMAIN (TREE_TYPE (array))))
2308         {
2309           if (!c_mark_addressable (array))
2310             return error_mark_node;
2311         }
2312
2313       if (pedantic)
2314         {
2315           tree foo = array;
2316           while (TREE_CODE (foo) == COMPONENT_REF)
2317             foo = TREE_OPERAND (foo, 0);
2318           if (TREE_CODE (foo) == VAR_DECL && C_DECL_REGISTER (foo))
2319             pedwarn (loc, OPT_pedantic,
2320                      "ISO C forbids subscripting %<register%> array");
2321           else if (!flag_isoc99 && !lvalue_p (foo))
2322             pedwarn (loc, OPT_pedantic,
2323                      "ISO C90 forbids subscripting non-lvalue array");
2324         }
2325
2326       type = TREE_TYPE (TREE_TYPE (array));
2327       rval = build4 (ARRAY_REF, type, array, index, NULL_TREE, NULL_TREE);
2328       /* Array ref is const/volatile if the array elements are
2329          or if the array is.  */
2330       TREE_READONLY (rval)
2331         |= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array)))
2332             | TREE_READONLY (array));
2333       TREE_SIDE_EFFECTS (rval)
2334         |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
2335             | TREE_SIDE_EFFECTS (array));
2336       TREE_THIS_VOLATILE (rval)
2337         |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
2338             /* This was added by rms on 16 Nov 91.
2339                It fixes  vol struct foo *a;  a->elts[1]
2340                in an inline function.
2341                Hope it doesn't break something else.  */
2342             | TREE_THIS_VOLATILE (array));
2343       ret = require_complete_type (rval);
2344       protected_set_expr_location (ret, loc);
2345       return ret;
2346     }
2347   else
2348     {
2349       tree ar = default_conversion (array);
2350
2351       if (ar == error_mark_node)
2352         return ar;
2353
2354       gcc_assert (TREE_CODE (TREE_TYPE (ar)) == POINTER_TYPE);
2355       gcc_assert (TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) != FUNCTION_TYPE);
2356
2357       return build_indirect_ref
2358         (loc, build_binary_op (loc, PLUS_EXPR, ar, index, 0),
2359          RO_ARRAY_INDEXING);
2360     }
2361 }
2362 \f
2363 /* Build an external reference to identifier ID.  FUN indicates
2364    whether this will be used for a function call.  LOC is the source
2365    location of the identifier.  This sets *TYPE to the type of the
2366    identifier, which is not the same as the type of the returned value
2367    for CONST_DECLs defined as enum constants.  If the type of the
2368    identifier is not available, *TYPE is set to NULL.  */
2369 tree
2370 build_external_ref (location_t loc, tree id, int fun, tree *type)
2371 {
2372   tree ref;
2373   tree decl = lookup_name (id);
2374
2375   /* In Objective-C, an instance variable (ivar) may be preferred to
2376      whatever lookup_name() found.  */
2377   decl = objc_lookup_ivar (decl, id);
2378
2379   *type = NULL;
2380   if (decl && decl != error_mark_node)
2381     {
2382       ref = decl;
2383       *type = TREE_TYPE (ref);
2384     }
2385   else if (fun)
2386     /* Implicit function declaration.  */
2387     ref = implicitly_declare (loc, id);
2388   else if (decl == error_mark_node)
2389     /* Don't complain about something that's already been
2390        complained about.  */
2391     return error_mark_node;
2392   else
2393     {
2394       undeclared_variable (loc, id);
2395       return error_mark_node;
2396     }
2397
2398   if (TREE_TYPE (ref) == error_mark_node)
2399     return error_mark_node;
2400
2401   if (TREE_DEPRECATED (ref))
2402     warn_deprecated_use (ref, NULL_TREE);
2403
2404   /* Recursive call does not count as usage.  */
2405   if (ref != current_function_decl)
2406     {
2407       TREE_USED (ref) = 1;
2408     }
2409
2410   if (TREE_CODE (ref) == FUNCTION_DECL && !in_alignof)
2411     {
2412       if (!in_sizeof && !in_typeof)
2413         C_DECL_USED (ref) = 1;
2414       else if (DECL_INITIAL (ref) == 0
2415                && DECL_EXTERNAL (ref)
2416                && !TREE_PUBLIC (ref))
2417         record_maybe_used_decl (ref);
2418     }
2419
2420   if (TREE_CODE (ref) == CONST_DECL)
2421     {
2422       used_types_insert (TREE_TYPE (ref));
2423
2424       if (warn_cxx_compat
2425           && TREE_CODE (TREE_TYPE (ref)) == ENUMERAL_TYPE
2426           && C_TYPE_DEFINED_IN_STRUCT (TREE_TYPE (ref)))
2427         {
2428           warning_at (loc, OPT_Wc___compat,
2429                       ("enum constant defined in struct or union "
2430                        "is not visible in C++"));
2431           inform (DECL_SOURCE_LOCATION (ref), "enum constant defined here");
2432         }
2433
2434       ref = DECL_INITIAL (ref);
2435       TREE_CONSTANT (ref) = 1;
2436     }
2437   else if (current_function_decl != 0
2438            && !DECL_FILE_SCOPE_P (current_function_decl)
2439            && (TREE_CODE (ref) == VAR_DECL
2440                || TREE_CODE (ref) == PARM_DECL
2441                || TREE_CODE (ref) == FUNCTION_DECL))
2442     {
2443       tree context = decl_function_context (ref);
2444
2445       if (context != 0 && context != current_function_decl)
2446         DECL_NONLOCAL (ref) = 1;
2447     }
2448   /* C99 6.7.4p3: An inline definition of a function with external
2449      linkage ... shall not contain a reference to an identifier with
2450      internal linkage.  */
2451   else if (current_function_decl != 0
2452            && DECL_DECLARED_INLINE_P (current_function_decl)
2453            && DECL_EXTERNAL (current_function_decl)
2454            && VAR_OR_FUNCTION_DECL_P (ref)
2455            && (TREE_CODE (ref) != VAR_DECL || TREE_STATIC (ref))
2456            && ! TREE_PUBLIC (ref)
2457            && DECL_CONTEXT (ref) != current_function_decl)
2458     record_inline_static (loc, current_function_decl, ref,
2459                           csi_internal);
2460
2461   return ref;
2462 }
2463
2464 /* Record details of decls possibly used inside sizeof or typeof.  */
2465 struct maybe_used_decl
2466 {
2467   /* The decl.  */
2468   tree decl;
2469   /* The level seen at (in_sizeof + in_typeof).  */
2470   int level;
2471   /* The next one at this level or above, or NULL.  */
2472   struct maybe_used_decl *next;
2473 };
2474
2475 static struct maybe_used_decl *maybe_used_decls;
2476
2477 /* Record that DECL, an undefined static function reference seen
2478    inside sizeof or typeof, might be used if the operand of sizeof is
2479    a VLA type or the operand of typeof is a variably modified
2480    type.  */
2481
2482 static void
2483 record_maybe_used_decl (tree decl)
2484 {
2485   struct maybe_used_decl *t = XOBNEW (&parser_obstack, struct maybe_used_decl);
2486   t->decl = decl;
2487   t->level = in_sizeof + in_typeof;
2488   t->next = maybe_used_decls;
2489   maybe_used_decls = t;
2490 }
2491
2492 /* Pop the stack of decls possibly used inside sizeof or typeof.  If
2493    USED is false, just discard them.  If it is true, mark them used
2494    (if no longer inside sizeof or typeof) or move them to the next
2495    level up (if still inside sizeof or typeof).  */
2496
2497 void
2498 pop_maybe_used (bool used)
2499 {
2500   struct maybe_used_decl *p = maybe_used_decls;
2501   int cur_level = in_sizeof + in_typeof;
2502   while (p && p->level > cur_level)
2503     {
2504       if (used)
2505         {
2506           if (cur_level == 0)
2507             C_DECL_USED (p->decl) = 1;
2508           else
2509             p->level = cur_level;
2510         }
2511       p = p->next;
2512     }
2513   if (!used || cur_level == 0)
2514     maybe_used_decls = p;
2515 }
2516
2517 /* Return the result of sizeof applied to EXPR.  */
2518
2519 struct c_expr
2520 c_expr_sizeof_expr (location_t loc, struct c_expr expr)
2521 {
2522   struct c_expr ret;
2523   if (expr.value == error_mark_node)
2524     {
2525       ret.value = error_mark_node;
2526       ret.original_code = ERROR_MARK;
2527       ret.original_type = NULL;
2528       pop_maybe_used (false);
2529     }
2530   else
2531     {
2532       bool expr_const_operands = true;
2533       tree folded_expr = c_fully_fold (expr.value, require_constant_value,
2534                                        &expr_const_operands);
2535       ret.value = c_sizeof (loc, TREE_TYPE (folded_expr));
2536       ret.original_code = ERROR_MARK;
2537       ret.original_type = NULL;
2538       if (c_vla_type_p (TREE_TYPE (folded_expr)))
2539         {
2540           /* sizeof is evaluated when given a vla (C99 6.5.3.4p2).  */
2541           ret.value = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (ret.value),
2542                               folded_expr, ret.value);
2543           C_MAYBE_CONST_EXPR_NON_CONST (ret.value) = !expr_const_operands;
2544           SET_EXPR_LOCATION (ret.value, loc);
2545         }
2546       pop_maybe_used (C_TYPE_VARIABLE_SIZE (TREE_TYPE (folded_expr)));
2547     }
2548   return ret;
2549 }
2550
2551 /* Return the result of sizeof applied to T, a structure for the type
2552    name passed to sizeof (rather than the type itself).  LOC is the
2553    location of the original expression.  */
2554
2555 struct c_expr
2556 c_expr_sizeof_type (location_t loc, struct c_type_name *t)
2557 {
2558   tree type;
2559   struct c_expr ret;
2560   tree type_expr = NULL_TREE;
2561   bool type_expr_const = true;
2562   type = groktypename (t, &type_expr, &type_expr_const);
2563   ret.value = c_sizeof (loc, type);
2564   ret.original_code = ERROR_MARK;
2565   ret.original_type = NULL;
2566   if ((type_expr || TREE_CODE (ret.value) == INTEGER_CST)
2567       && c_vla_type_p (type))
2568     {
2569       /* If the type is a [*] array, it is a VLA but is represented as
2570          having a size of zero.  In such a case we must ensure that
2571          the result of sizeof does not get folded to a constant by
2572          c_fully_fold, because if the size is evaluated the result is
2573          not constant and so constraints on zero or negative size
2574          arrays must not be applied when this sizeof call is inside
2575          another array declarator.  */
2576       if (!type_expr)
2577         type_expr = integer_zero_node;
2578       ret.value = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (ret.value),
2579                           type_expr, ret.value);
2580       C_MAYBE_CONST_EXPR_NON_CONST (ret.value) = !type_expr_const;
2581     }
2582   pop_maybe_used (type != error_mark_node
2583                   ? C_TYPE_VARIABLE_SIZE (type) : false);
2584   return ret;
2585 }
2586
2587 /* Build a function call to function FUNCTION with parameters PARAMS.
2588    The function call is at LOC.
2589    PARAMS is a list--a chain of TREE_LIST nodes--in which the
2590    TREE_VALUE of each node is a parameter-expression.
2591    FUNCTION's data type may be a function type or a pointer-to-function.  */
2592
2593 tree
2594 build_function_call (location_t loc, tree function, tree params)
2595 {
2596   VEC(tree,gc) *vec;
2597   tree ret;
2598
2599   vec = VEC_alloc (tree, gc, list_length (params));
2600   for (; params; params = TREE_CHAIN (params))
2601     VEC_quick_push (tree, vec, TREE_VALUE (params));
2602   ret = build_function_call_vec (loc, function, vec, NULL);
2603   VEC_free (tree, gc, vec);
2604   return ret;
2605 }
2606
2607 /* Build a function call to function FUNCTION with parameters PARAMS.
2608    ORIGTYPES, if not NULL, is a vector of types; each element is
2609    either NULL or the original type of the corresponding element in
2610    PARAMS.  The original type may differ from TREE_TYPE of the
2611    parameter for enums.  FUNCTION's data type may be a function type
2612    or pointer-to-function.  This function changes the elements of
2613    PARAMS.  */
2614
2615 tree
2616 build_function_call_vec (location_t loc, tree function, VEC(tree,gc) *params,
2617                          VEC(tree,gc) *origtypes)
2618 {
2619   tree fntype, fundecl = 0;
2620   tree name = NULL_TREE, result;
2621   tree tem;
2622   int nargs;
2623   tree *argarray;
2624
2625
2626   /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue.  */
2627   STRIP_TYPE_NOPS (function);
2628
2629   /* Convert anything with function type to a pointer-to-function.  */
2630   if (TREE_CODE (function) == FUNCTION_DECL)
2631     {
2632       /* Implement type-directed function overloading for builtins.
2633          resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2634          handle all the type checking.  The result is a complete expression
2635          that implements this function call.  */
2636       tem = resolve_overloaded_builtin (loc, function, params);
2637       if (tem)
2638         return tem;
2639
2640       name = DECL_NAME (function);
2641       fundecl = function;
2642     }
2643   if (TREE_CODE (TREE_TYPE (function)) == FUNCTION_TYPE)
2644     function = function_to_pointer_conversion (loc, function);
2645
2646   /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2647      expressions, like those used for ObjC messenger dispatches.  */
2648   if (!VEC_empty (tree, params))
2649     function = objc_rewrite_function_call (function,
2650                                            VEC_index (tree, params, 0));
2651
2652   function = c_fully_fold (function, false, NULL);
2653
2654   fntype = TREE_TYPE (function);
2655
2656   if (TREE_CODE (fntype) == ERROR_MARK)
2657     return error_mark_node;
2658
2659   if (!(TREE_CODE (fntype) == POINTER_TYPE
2660         && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE))
2661     {
2662       error_at (loc, "called object %qE is not a function", function);
2663       return error_mark_node;
2664     }
2665
2666   if (fundecl && TREE_THIS_VOLATILE (fundecl))
2667     current_function_returns_abnormally = 1;
2668
2669   /* fntype now gets the type of function pointed to.  */
2670   fntype = TREE_TYPE (fntype);
2671
2672   /* Convert the parameters to the types declared in the
2673      function prototype, or apply default promotions.  */
2674
2675   nargs = convert_arguments (TYPE_ARG_TYPES (fntype), params, origtypes,
2676                              function, fundecl);
2677   if (nargs < 0)
2678     return error_mark_node;
2679
2680   /* Check that the function is called through a compatible prototype.
2681      If it is not, replace the call by a trap, wrapped up in a compound
2682      expression if necessary.  This has the nice side-effect to prevent
2683      the tree-inliner from generating invalid assignment trees which may
2684      blow up in the RTL expander later.  */
2685   if (CONVERT_EXPR_P (function)
2686       && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR
2687       && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL
2688       && !comptypes (fntype, TREE_TYPE (tem)))
2689     {
2690       tree return_type = TREE_TYPE (fntype);
2691       tree trap = build_function_call (loc, built_in_decls[BUILT_IN_TRAP],
2692                                        NULL_TREE);
2693       int i;
2694
2695       /* This situation leads to run-time undefined behavior.  We can't,
2696          therefore, simply error unless we can prove that all possible
2697          executions of the program must execute the code.  */
2698       if (warning_at (loc, 0, "function called through a non-compatible type"))
2699         /* We can, however, treat "undefined" any way we please.
2700            Call abort to encourage the user to fix the program.  */
2701         inform (loc, "if this code is reached, the program will abort");
2702       /* Before the abort, allow the function arguments to exit or
2703          call longjmp.  */
2704       for (i = 0; i < nargs; i++)
2705         trap = build2 (COMPOUND_EXPR, void_type_node,
2706                        VEC_index (tree, params, i), trap);
2707
2708       if (VOID_TYPE_P (return_type))
2709         {
2710           if (TYPE_QUALS (return_type) != TYPE_UNQUALIFIED)
2711             pedwarn (loc, 0,
2712                      "function with qualified void return type called");
2713           return trap;
2714         }
2715       else
2716         {
2717           tree rhs;
2718
2719           if (AGGREGATE_TYPE_P (return_type))
2720             rhs = build_compound_literal (loc, return_type,
2721                                           build_constructor (return_type, 0),
2722                                           false);
2723           else
2724             rhs = fold_convert_loc (loc, return_type, integer_zero_node);
2725
2726           return require_complete_type (build2 (COMPOUND_EXPR, return_type,
2727                                                 trap, rhs));
2728         }
2729     }
2730
2731   argarray = VEC_address (tree, params);
2732
2733   /* Check that arguments to builtin functions match the expectations.  */
2734   if (fundecl
2735       && DECL_BUILT_IN (fundecl)
2736       && DECL_BUILT_IN_CLASS (fundecl) == BUILT_IN_NORMAL
2737       && !check_builtin_function_arguments (fundecl, nargs, argarray))
2738     return error_mark_node;
2739
2740   /* Check that the arguments to the function are valid.  */
2741   check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2742                             TYPE_ARG_TYPES (fntype));
2743
2744   if (name != NULL_TREE
2745       && !strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10))
2746     {
2747       if (require_constant_value)
2748         result =
2749           fold_build_call_array_initializer_loc (loc, TREE_TYPE (fntype),
2750                                                  function, nargs, argarray);
2751       else
2752         result = fold_build_call_array_loc (loc, TREE_TYPE (fntype),
2753                                             function, nargs, argarray);
2754       if (TREE_CODE (result) == NOP_EXPR
2755           && TREE_CODE (TREE_OPERAND (result, 0)) == INTEGER_CST)
2756         STRIP_TYPE_NOPS (result);
2757     }
2758   else
2759     result = build_call_array_loc (loc, TREE_TYPE (fntype),
2760                                    function, nargs, argarray);
2761
2762   if (VOID_TYPE_P (TREE_TYPE (result)))
2763     {
2764       if (TYPE_QUALS (TREE_TYPE (result)) != TYPE_UNQUALIFIED)
2765         pedwarn (loc, 0,
2766                  "function with qualified void return type called");
2767       return result;
2768     }
2769   return require_complete_type (result);
2770 }
2771 \f
2772 /* Convert the argument expressions in the vector VALUES
2773    to the types in the list TYPELIST.
2774
2775    If TYPELIST is exhausted, or when an element has NULL as its type,
2776    perform the default conversions.
2777
2778    ORIGTYPES is the original types of the expressions in VALUES.  This
2779    holds the type of enum values which have been converted to integral
2780    types.  It may be NULL.
2781
2782    FUNCTION is a tree for the called function.  It is used only for
2783    error messages, where it is formatted with %qE.
2784
2785    This is also where warnings about wrong number of args are generated.
2786
2787    Returns the actual number of arguments processed (which may be less
2788    than the length of VALUES in some error situations), or -1 on
2789    failure.  */
2790
2791 static int
2792 convert_arguments (tree typelist, VEC(tree,gc) *values,
2793                    VEC(tree,gc) *origtypes, tree function, tree fundecl)
2794 {
2795   tree typetail, val;
2796   unsigned int parmnum;
2797   bool error_args = false;
2798   const bool type_generic = fundecl
2799     && lookup_attribute ("type generic", TYPE_ATTRIBUTES(TREE_TYPE (fundecl)));
2800   bool type_generic_remove_excess_precision = false;
2801   tree selector;
2802
2803   /* Change pointer to function to the function itself for
2804      diagnostics.  */
2805   if (TREE_CODE (function) == ADDR_EXPR
2806       && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
2807     function = TREE_OPERAND (function, 0);
2808
2809   /* Handle an ObjC selector specially for diagnostics.  */
2810   selector = objc_message_selector ();
2811
2812   /* For type-generic built-in functions, determine whether excess
2813      precision should be removed (classification) or not
2814      (comparison).  */
2815   if (type_generic
2816       && DECL_BUILT_IN (fundecl)
2817       && DECL_BUILT_IN_CLASS (fundecl) == BUILT_IN_NORMAL)
2818     {
2819       switch (DECL_FUNCTION_CODE (fundecl))
2820         {
2821         case BUILT_IN_ISFINITE:
2822         case BUILT_IN_ISINF:
2823         case BUILT_IN_ISINF_SIGN:
2824         case BUILT_IN_ISNAN:
2825         case BUILT_IN_ISNORMAL:
2826         case BUILT_IN_FPCLASSIFY:
2827           type_generic_remove_excess_precision = true;
2828           break;
2829
2830         default:
2831           type_generic_remove_excess_precision = false;
2832           break;
2833         }
2834     }
2835
2836   /* Scan the given expressions and types, producing individual
2837      converted arguments.  */
2838
2839   for (typetail = typelist, parmnum = 0;
2840        VEC_iterate (tree, values, parmnum, val);
2841        ++parmnum)
2842     {
2843       tree type = typetail ? TREE_VALUE (typetail) : 0;
2844       tree valtype = TREE_TYPE (val);
2845       tree rname = function;
2846       int argnum = parmnum + 1;
2847       const char *invalid_func_diag;
2848       bool excess_precision = false;
2849       bool npc;
2850       tree parmval;
2851
2852       if (type == void_type_node)
2853         {
2854           error_at (input_location,
2855                     "too many arguments to function %qE", function);
2856           if (fundecl && !DECL_BUILT_IN (fundecl))
2857             inform (DECL_SOURCE_LOCATION (fundecl), "declared here");
2858           return parmnum;
2859         }
2860
2861       if (selector && argnum > 2)
2862         {
2863           rname = selector;
2864           argnum -= 2;
2865         }
2866
2867       npc = null_pointer_constant_p (val);
2868
2869       /* If there is excess precision and a prototype, convert once to
2870          the required type rather than converting via the semantic
2871          type.  Likewise without a prototype a float value represented
2872          as long double should be converted once to double.  But for
2873          type-generic classification functions excess precision must
2874          be removed here.  */
2875       if (TREE_CODE (val) == EXCESS_PRECISION_EXPR
2876           && (type || !type_generic || !type_generic_remove_excess_precision))
2877         {
2878           val = TREE_OPERAND (val, 0);
2879           excess_precision = true;
2880         }
2881       val = c_fully_fold (val, false, NULL);
2882       STRIP_TYPE_NOPS (val);
2883
2884       val = require_complete_type (val);
2885
2886       if (type != 0)
2887         {
2888           /* Formal parm type is specified by a function prototype.  */
2889
2890           if (type == error_mark_node || !COMPLETE_TYPE_P (type))
2891             {
2892               error ("type of formal parameter %d is incomplete", parmnum + 1);
2893               parmval = val;
2894             }
2895           else
2896             {
2897               tree origtype;
2898
2899               /* Optionally warn about conversions that
2900                  differ from the default conversions.  */
2901               if (warn_traditional_conversion || warn_traditional)
2902                 {
2903                   unsigned int formal_prec = TYPE_PRECISION (type);
2904
2905                   if (INTEGRAL_TYPE_P (type)
2906                       && TREE_CODE (valtype) == REAL_TYPE)
2907                     warning (0, "passing argument %d of %qE as integer "
2908                              "rather than floating due to prototype",
2909                              argnum, rname);
2910                   if (INTEGRAL_TYPE_P (type)
2911                       && TREE_CODE (valtype) == COMPLEX_TYPE)
2912                     warning (0, "passing argument %d of %qE as integer "
2913                              "rather than complex due to prototype",
2914                              argnum, rname);
2915                   else if (TREE_CODE (type) == COMPLEX_TYPE
2916                            && TREE_CODE (valtype) == REAL_TYPE)
2917                     warning (0, "passing argument %d of %qE as complex "
2918                              "rather than floating due to prototype",
2919                              argnum, rname);
2920                   else if (TREE_CODE (type) == REAL_TYPE
2921                            && INTEGRAL_TYPE_P (valtype))
2922                     warning (0, "passing argument %d of %qE as floating "
2923                              "rather than integer due to prototype",
2924                              argnum, rname);
2925                   else if (TREE_CODE (type) == COMPLEX_TYPE
2926                            && INTEGRAL_TYPE_P (valtype))
2927                     warning (0, "passing argument %d of %qE as complex "
2928                              "rather than integer due to prototype",
2929                              argnum, rname);
2930                   else if (TREE_CODE (type) == REAL_TYPE
2931                            && TREE_CODE (valtype) == COMPLEX_TYPE)
2932                     warning (0, "passing argument %d of %qE as floating "
2933                              "rather than complex due to prototype",
2934                              argnum, rname);
2935                   /* ??? At some point, messages should be written about
2936                      conversions between complex types, but that's too messy
2937                      to do now.  */
2938                   else if (TREE_CODE (type) == REAL_TYPE
2939                            && TREE_CODE (valtype) == REAL_TYPE)
2940                     {
2941                       /* Warn if any argument is passed as `float',
2942                          since without a prototype it would be `double'.  */
2943                       if (formal_prec == TYPE_PRECISION (float_type_node)
2944                           && type != dfloat32_type_node)
2945                         warning (0, "passing argument %d of %qE as %<float%> "
2946                                  "rather than %<double%> due to prototype",
2947                                  argnum, rname);
2948
2949                       /* Warn if mismatch between argument and prototype
2950                          for decimal float types.  Warn of conversions with
2951                          binary float types and of precision narrowing due to
2952                          prototype. */
2953                       else if (type != valtype
2954                                && (type == dfloat32_type_node
2955                                    || type == dfloat64_type_node
2956                                    || type == dfloat128_type_node
2957                                    || valtype == dfloat32_type_node
2958                                    || valtype == dfloat64_type_node
2959                                    || valtype == dfloat128_type_node)
2960                                && (formal_prec
2961                                    <= TYPE_PRECISION (valtype)
2962                                    || (type == dfloat128_type_node
2963                                        && (valtype
2964                                            != dfloat64_type_node
2965                                            && (valtype
2966                                                != dfloat32_type_node)))
2967                                    || (type == dfloat64_type_node
2968                                        && (valtype
2969                                            != dfloat32_type_node))))
2970                         warning (0, "passing argument %d of %qE as %qT "
2971                                  "rather than %qT due to prototype",
2972                                  argnum, rname, type, valtype);
2973
2974                     }
2975                   /* Detect integer changing in width or signedness.
2976                      These warnings are only activated with
2977                      -Wtraditional-conversion, not with -Wtraditional.  */
2978                   else if (warn_traditional_conversion && INTEGRAL_TYPE_P (type)
2979                            && INTEGRAL_TYPE_P (valtype))
2980                     {
2981                       tree would_have_been = default_conversion (val);
2982                       tree type1 = TREE_TYPE (would_have_been);
2983
2984                       if (TREE_CODE (type) == ENUMERAL_TYPE
2985                           && (TYPE_MAIN_VARIANT (type)
2986                               == TYPE_MAIN_VARIANT (valtype)))
2987                         /* No warning if function asks for enum
2988                            and the actual arg is that enum type.  */
2989                         ;
2990                       else if (formal_prec != TYPE_PRECISION (type1))
2991                         warning (OPT_Wtraditional_conversion,
2992                                  "passing argument %d of %qE "
2993                                  "with different width due to prototype",
2994                                  argnum, rname);
2995                       else if (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (type1))
2996                         ;
2997                       /* Don't complain if the formal parameter type
2998                          is an enum, because we can't tell now whether
2999                          the value was an enum--even the same enum.  */
3000                       else if (TREE_CODE (type) == ENUMERAL_TYPE)
3001                         ;
3002                       else if (TREE_CODE (val) == INTEGER_CST
3003                                && int_fits_type_p (val, type))
3004                         /* Change in signedness doesn't matter
3005                            if a constant value is unaffected.  */
3006                         ;
3007                       /* If the value is extended from a narrower
3008                          unsigned type, it doesn't matter whether we
3009                          pass it as signed or unsigned; the value
3010                          certainly is the same either way.  */
3011                       else if (TYPE_PRECISION (valtype) < TYPE_PRECISION (type)
3012                                && TYPE_UNSIGNED (valtype))
3013                         ;
3014                       else if (TYPE_UNSIGNED (type))
3015                         warning (OPT_Wtraditional_conversion,
3016                                  "passing argument %d of %qE "
3017                                  "as unsigned due to prototype",
3018                                  argnum, rname);
3019                       else
3020                         warning (OPT_Wtraditional_conversion,
3021                                  "passing argument %d of %qE "
3022                                  "as signed due to prototype", argnum, rname);
3023                     }
3024                 }
3025
3026               /* Possibly restore an EXCESS_PRECISION_EXPR for the
3027                  sake of better warnings from convert_and_check.  */
3028               if (excess_precision)
3029                 val = build1 (EXCESS_PRECISION_EXPR, valtype, val);
3030               origtype = (origtypes == NULL
3031                           ? NULL_TREE
3032                           : VEC_index (tree, origtypes, parmnum));
3033               parmval = convert_for_assignment (input_location, type, val,
3034                                                 origtype, ic_argpass, npc,
3035                                                 fundecl, function,
3036                                                 parmnum + 1);
3037
3038               if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0)
3039                   && INTEGRAL_TYPE_P (type)
3040                   && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
3041                 parmval = default_conversion (parmval);
3042             }
3043         }
3044       else if (TREE_CODE (valtype) == REAL_TYPE
3045                && (TYPE_PRECISION (valtype)
3046                    < TYPE_PRECISION (double_type_node))
3047                && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (valtype)))
3048         {
3049           if (type_generic)
3050             parmval = val;
3051           else
3052             /* Convert `float' to `double'.  */
3053             parmval = convert (double_type_node, val);
3054         }
3055       else if (excess_precision && !type_generic)
3056         /* A "double" argument with excess precision being passed
3057            without a prototype or in variable arguments.  */
3058         parmval = convert (valtype, val);
3059       else if ((invalid_func_diag =
3060                 targetm.calls.invalid_arg_for_unprototyped_fn (typelist, fundecl, val)))
3061         {
3062           error (invalid_func_diag);
3063           return -1;
3064         }
3065       else
3066         /* Convert `short' and `char' to full-size `int'.  */
3067         parmval = default_conversion (val);
3068
3069       VEC_replace (tree, values, parmnum, parmval);
3070       if (parmval == error_mark_node)
3071         error_args = true;
3072
3073       if (typetail)
3074         typetail = TREE_CHAIN (typetail);
3075     }
3076
3077   gcc_assert (parmnum == VEC_length (tree, values));
3078
3079   if (typetail != 0 && TREE_VALUE (typetail) != void_type_node)
3080     {
3081       error_at (input_location,
3082                 "too few arguments to function %qE", function);
3083       if (fundecl && !DECL_BUILT_IN (fundecl))
3084         inform (DECL_SOURCE_LOCATION (fundecl), "declared here");
3085       return -1;
3086     }
3087
3088   return error_args ? -1 : (int) parmnum;
3089 }
3090 \f
3091 /* This is the entry point used by the parser to build unary operators
3092    in the input.  CODE, a tree_code, specifies the unary operator, and
3093    ARG is the operand.  For unary plus, the C parser currently uses
3094    CONVERT_EXPR for code.
3095
3096    LOC is the location to use for the tree generated.
3097 */
3098
3099 struct c_expr
3100 parser_build_unary_op (location_t loc, enum tree_code code, struct c_expr arg)
3101 {
3102   struct c_expr result;
3103
3104   result.value = build_unary_op (loc, code, arg.value, 0);
3105   result.original_code = code;
3106   result.original_type = NULL;
3107
3108   if (TREE_OVERFLOW_P (result.value) && !TREE_OVERFLOW_P (arg.value))
3109     overflow_warning (loc, result.value);
3110
3111   return result;
3112 }
3113
3114 /* This is the entry point used by the parser to build binary operators
3115    in the input.  CODE, a tree_code, specifies the binary operator, and
3116    ARG1 and ARG2 are the operands.  In addition to constructing the
3117    expression, we check for operands that were written with other binary
3118    operators in a way that is likely to confuse the user.
3119
3120    LOCATION is the location of the binary operator.  */
3121
3122 struct c_expr
3123 parser_build_binary_op (location_t location, enum tree_code code,
3124                         struct c_expr arg1, struct c_expr arg2)
3125 {
3126   struct c_expr result;
3127
3128   enum tree_code code1 = arg1.original_code;
3129   enum tree_code code2 = arg2.original_code;
3130   tree type1 = (arg1.original_type
3131                 ? arg1.original_type
3132                 : TREE_TYPE (arg1.value));
3133   tree type2 = (arg2.original_type
3134                 ? arg2.original_type
3135                 : TREE_TYPE (arg2.value));
3136
3137   result.value = build_binary_op (location, code,
3138                                   arg1.value, arg2.value, 1);
3139   result.original_code = code;
3140   result.original_type = NULL;
3141
3142   if (TREE_CODE (result.value) == ERROR_MARK)
3143     return result;
3144
3145   if (location != UNKNOWN_LOCATION)
3146     protected_set_expr_location (result.value, location);
3147
3148   /* Check for cases such as x+y<<z which users are likely
3149      to misinterpret.  */
3150   if (warn_parentheses)
3151     warn_about_parentheses (code, code1, arg1.value, code2, arg2.value);
3152
3153   if (warn_logical_op)
3154     warn_logical_operator (input_location, code, TREE_TYPE (result.value),
3155                            code1, arg1.value, code2, arg2.value);
3156
3157   /* Warn about comparisons against string literals, with the exception
3158      of testing for equality or inequality of a string literal with NULL.  */
3159   if (code == EQ_EXPR || code == NE_EXPR)
3160     {
3161       if ((code1 == STRING_CST && !integer_zerop (arg2.value))
3162           || (code2 == STRING_CST && !integer_zerop (arg1.value)))
3163         warning_at (location, OPT_Waddress,
3164                     "comparison with string literal results in unspecified behavior");
3165     }
3166   else if (TREE_CODE_CLASS (code) == tcc_comparison
3167            && (code1 == STRING_CST || code2 == STRING_CST))
3168     warning_at (location, OPT_Waddress,
3169                 "comparison with string literal results in unspecified behavior");
3170
3171   if (TREE_OVERFLOW_P (result.value)
3172       && !TREE_OVERFLOW_P (arg1.value)
3173       && !TREE_OVERFLOW_P (arg2.value))
3174     overflow_warning (location, result.value);
3175
3176   /* Warn about comparisons of different enum types.  */
3177   if (warn_enum_compare
3178       && TREE_CODE_CLASS (code) == tcc_comparison
3179       && TREE_CODE (type1) == ENUMERAL_TYPE
3180       && TREE_CODE (type2) == ENUMERAL_TYPE
3181       && TYPE_MAIN_VARIANT (type1) != TYPE_MAIN_VARIANT (type2))
3182     warning_at (location, OPT_Wenum_compare,
3183                 "comparison between %qT and %qT",
3184                 type1, type2);
3185
3186   return result;
3187 }
3188 \f
3189 /* Return a tree for the difference of pointers OP0 and OP1.
3190    The resulting tree has type int.  */
3191
3192 static tree
3193 pointer_diff (location_t loc, tree op0, tree op1)
3194 {
3195   tree restype = ptrdiff_type_node;
3196   tree result, inttype;
3197
3198   addr_space_t as0 = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (op0)));
3199   addr_space_t as1 = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (op1)));
3200   tree target_type = TREE_TYPE (TREE_TYPE (op0));
3201   tree con0, con1, lit0, lit1;
3202   tree orig_op1 = op1;
3203
3204   /* If the operands point into different address spaces, we need to
3205      explicitly convert them to pointers into the common address space
3206      before we can subtract the numerical address values.  */
3207   if (as0 != as1)
3208     {
3209       addr_space_t as_common;
3210       tree common_type;
3211
3212       /* Determine the common superset address space.  This is guaranteed
3213          to exist because the caller verified that comp_target_types
3214          returned non-zero.  */
3215       if (!addr_space_superset (as0, as1, &as_common))
3216         gcc_unreachable ();
3217
3218       common_type = common_pointer_type (TREE_TYPE (op0), TREE_TYPE (op1));
3219       op0 = convert (common_type, op0);
3220       op1 = convert (common_type, op1);
3221     }
3222
3223   /* Determine integer type to perform computations in.  This will usually
3224      be the same as the result type (ptrdiff_t), but may need to be a wider
3225      type if pointers for the address space are wider than ptrdiff_t.  */
3226   if (TYPE_PRECISION (restype) < TYPE_PRECISION (TREE_TYPE (op0)))
3227     inttype = lang_hooks.types.type_for_size
3228                 (TYPE_PRECISION (TREE_TYPE (op0)), 0);
3229   else
3230     inttype = restype;
3231
3232
3233   if (TREE_CODE (target_type) == VOID_TYPE)
3234     pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3235              "pointer of type %<void *%> used in subtraction");
3236   if (TREE_CODE (target_type) == FUNCTION_TYPE)
3237     pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3238              "pointer to a function used in subtraction");
3239
3240   /* If the conversion to ptrdiff_type does anything like widening or
3241      converting a partial to an integral mode, we get a convert_expression
3242      that is in the way to do any simplifications.
3243      (fold-const.c doesn't know that the extra bits won't be needed.
3244      split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
3245      different mode in place.)
3246      So first try to find a common term here 'by hand'; we want to cover
3247      at least the cases that occur in legal static initializers.  */
3248   if (CONVERT_EXPR_P (op0)
3249       && (TYPE_PRECISION (TREE_TYPE (op0))
3250           == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
3251     con0 = TREE_OPERAND (op0, 0);
3252   else
3253     con0 = op0;
3254   if (CONVERT_EXPR_P (op1)
3255       && (TYPE_PRECISION (TREE_TYPE (op1))
3256           == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op1, 0)))))
3257     con1 = TREE_OPERAND (op1, 0);
3258   else
3259     con1 = op1;
3260
3261   if (TREE_CODE (con0) == PLUS_EXPR)
3262     {
3263       lit0 = TREE_OPERAND (con0, 1);
3264       con0 = TREE_OPERAND (con0, 0);
3265     }
3266   else
3267     lit0 = integer_zero_node;
3268
3269   if (TREE_CODE (con1) == PLUS_EXPR)
3270     {
3271       lit1 = TREE_OPERAND (con1, 1);
3272       con1 = TREE_OPERAND (con1, 0);
3273     }
3274   else
3275     lit1 = integer_zero_node;
3276
3277   if (operand_equal_p (con0, con1, 0))
3278     {
3279       op0 = lit0;
3280       op1 = lit1;
3281     }
3282
3283
3284   /* First do the subtraction as integers;
3285      then drop through to build the divide operator.
3286      Do not do default conversions on the minus operator
3287      in case restype is a short type.  */
3288
3289   op0 = build_binary_op (loc,
3290                          MINUS_EXPR, convert (inttype, op0),
3291                          convert (inttype, op1), 0);
3292   /* This generates an error if op1 is pointer to incomplete type.  */
3293   if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1))))
3294     error_at (loc, "arithmetic on pointer to an incomplete type");
3295
3296   /* This generates an error if op0 is pointer to incomplete type.  */
3297   op1 = c_size_in_bytes (target_type);
3298
3299   /* Divide by the size, in easiest possible way.  */
3300   result = fold_build2_loc (loc, EXACT_DIV_EXPR, inttype,
3301                             op0, convert (inttype, op1));
3302
3303   /* Convert to final result type if necessary.  */
3304   return convert (restype, result);
3305 }
3306 \f
3307 /* Construct and perhaps optimize a tree representation
3308    for a unary operation.  CODE, a tree_code, specifies the operation
3309    and XARG is the operand.
3310    For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
3311    the default promotions (such as from short to int).
3312    For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
3313    allows non-lvalues; this is only used to handle conversion of non-lvalue
3314    arrays to pointers in C99.
3315
3316    LOCATION is the location of the operator.  */
3317
3318 tree
3319 build_unary_op (location_t location,
3320                 enum tree_code code, tree xarg, int flag)
3321 {
3322   /* No default_conversion here.  It causes trouble for ADDR_EXPR.  */
3323   tree arg = xarg;
3324   tree argtype = 0;
3325   enum tree_code typecode;
3326   tree val;
3327   tree ret = error_mark_node;
3328   tree eptype = NULL_TREE;
3329   int noconvert = flag;
3330   const char *invalid_op_diag;
3331   bool int_operands;
3332
3333   int_operands = EXPR_INT_CONST_OPERANDS (xarg);
3334   if (int_operands)
3335     arg = remove_c_maybe_const_expr (arg);
3336
3337   if (code != ADDR_EXPR)
3338     arg = require_complete_type (arg);
3339
3340   typecode = TREE_CODE (TREE_TYPE (arg));
3341   if (typecode == ERROR_MARK)
3342     return error_mark_node;
3343   if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE)
3344     typecode = INTEGER_TYPE;
3345
3346   if ((invalid_op_diag
3347        = targetm.invalid_unary_op (code, TREE_TYPE (xarg))))
3348     {
3349       error_at (location, invalid_op_diag);
3350       return error_mark_node;
3351     }
3352
3353   if (TREE_CODE (arg) == EXCESS_PRECISION_EXPR)
3354     {
3355       eptype = TREE_TYPE (arg);
3356       arg = TREE_OPERAND (arg, 0);
3357     }
3358
3359   switch (code)
3360     {
3361     case CONVERT_EXPR:
3362       /* This is used for unary plus, because a CONVERT_EXPR
3363          is enough to prevent anybody from looking inside for
3364          associativity, but won't generate any code.  */
3365       if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
3366             || typecode == FIXED_POINT_TYPE || typecode == COMPLEX_TYPE
3367             || typecode == VECTOR_TYPE))
3368         {
3369           error_at (location, "wrong type argument to unary plus");
3370           return error_mark_node;
3371         }
3372       else if (!noconvert)
3373         arg = default_conversion (arg);
3374       arg = non_lvalue_loc (location, arg);
3375       break;
3376
3377     case NEGATE_EXPR:
3378       if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
3379             || typecode == FIXED_POINT_TYPE || typecode == COMPLEX_TYPE
3380             || typecode == VECTOR_TYPE))
3381         {
3382           error_at (location, "wrong type argument to unary minus");
3383           return error_mark_node;
3384         }
3385       else if (!noconvert)
3386         arg = default_conversion (arg);
3387       break;
3388
3389     case BIT_NOT_EXPR:
3390       /* ~ works on integer types and non float vectors. */
3391       if (typecode == INTEGER_TYPE
3392           || (typecode == VECTOR_TYPE
3393               && !VECTOR_FLOAT_TYPE_P (TREE_TYPE (arg))))
3394         {
3395           if (!noconvert)
3396             arg = default_conversion (arg);
3397         }
3398       else if (typecode == COMPLEX_TYPE)
3399         {
3400           code = CONJ_EXPR;
3401           pedwarn (location, OPT_pedantic,
3402                    "ISO C does not support %<~%> for complex conjugation");
3403           if (!noconvert)
3404             arg = default_conversion (arg);
3405         }
3406       else
3407         {
3408           error_at (location, "wrong type argument to bit-complement");
3409           return error_mark_node;
3410         }
3411       break;
3412
3413     case ABS_EXPR:
3414       if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE))
3415         {
3416           error_at (location, "wrong type argument to abs");
3417           return error_mark_node;
3418         }
3419       else if (!noconvert)
3420         arg = default_conversion (arg);
3421       break;
3422
3423     case CONJ_EXPR:
3424       /* Conjugating a real value is a no-op, but allow it anyway.  */
3425       if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
3426             || typecode == COMPLEX_TYPE))
3427         {
3428           error_at (location, "wrong type argument to conjugation");
3429           return error_mark_node;
3430         }
3431       else if (!noconvert)
3432         arg = default_conversion (arg);
3433       break;
3434
3435     case TRUTH_NOT_EXPR:
3436       if (typecode != INTEGER_TYPE && typecode != FIXED_POINT_TYPE
3437           && typecode != REAL_TYPE && typecode != POINTER_TYPE
3438           && typecode != COMPLEX_TYPE)
3439         {
3440           error_at (location,
3441                     "wrong type argument to unary exclamation mark");
3442           return error_mark_node;
3443         }
3444       arg = c_objc_common_truthvalue_conversion (location, arg);
3445       ret = invert_truthvalue_loc (location, arg);
3446       /* If the TRUTH_NOT_EXPR has been folded, reset the location.  */
3447       if (EXPR_P (ret) && EXPR_HAS_LOCATION (ret))
3448         location = EXPR_LOCATION (ret);
3449       goto return_build_unary_op;
3450
3451     case REALPART_EXPR:
3452       if (TREE_CODE (arg) == COMPLEX_CST)
3453         ret = TREE_REALPART (arg);
3454       else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3455         ret = fold_build1_loc (location,
3456                                REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3457       else
3458         ret = arg;
3459       if (eptype && TREE_CODE (eptype) == COMPLEX_TYPE)
3460         eptype = TREE_TYPE (eptype);
3461       goto return_build_unary_op;
3462
3463     case IMAGPART_EXPR:
3464       if (TREE_CODE (arg) == COMPLEX_CST)
3465         ret = TREE_IMAGPART (arg);
3466       else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3467         ret = fold_build1_loc (location,
3468                                IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3469       else
3470         ret = omit_one_operand_loc (location, TREE_TYPE (arg),
3471                                 integer_zero_node, arg);
3472       if (eptype && TREE_CODE (eptype) == COMPLEX_TYPE)
3473         eptype = TREE_TYPE (eptype);
3474       goto return_build_unary_op;
3475
3476     case PREINCREMENT_EXPR:
3477     case POSTINCREMENT_EXPR:
3478     case PREDECREMENT_EXPR:
3479     case POSTDECREMENT_EXPR:
3480
3481       if (TREE_CODE (arg) == C_MAYBE_CONST_EXPR)
3482         {
3483           tree inner = build_unary_op (location, code,
3484                                        C_MAYBE_CONST_EXPR_EXPR (arg), flag);
3485           if (inner == error_mark_node)
3486             return error_mark_node;
3487           ret = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (inner),
3488                         C_MAYBE_CONST_EXPR_PRE (arg), inner);
3489           gcc_assert (!C_MAYBE_CONST_EXPR_INT_OPERANDS (arg));
3490           C_MAYBE_CONST_EXPR_NON_CONST (ret) = 1;
3491           goto return_build_unary_op;
3492         }
3493
3494       /* Complain about anything that is not a true lvalue.  */
3495       if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3496                                   || code == POSTINCREMENT_EXPR)
3497                                  ? lv_increment
3498                                  : lv_decrement)))
3499         return error_mark_node;
3500
3501       if (warn_cxx_compat && TREE_CODE (TREE_TYPE (arg)) == ENUMERAL_TYPE)
3502         {
3503           if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3504             warning_at (location, OPT_Wc___compat,
3505                         "increment of enumeration value is invalid in C++");
3506           else
3507             warning_at (location, OPT_Wc___compat,
3508                         "decrement of enumeration value is invalid in C++");
3509         }
3510
3511       /* Ensure the argument is fully folded inside any SAVE_EXPR.  */
3512       arg = c_fully_fold (arg, false, NULL);
3513
3514       /* Increment or decrement the real part of the value,
3515          and don't change the imaginary part.  */
3516       if (typecode == COMPLEX_TYPE)
3517         {
3518           tree real, imag;
3519
3520           pedwarn (location, OPT_pedantic,
3521                    "ISO C does not support %<++%> and %<--%> on complex types");
3522
3523           arg = stabilize_reference (arg);
3524           real = build_unary_op (EXPR_LOCATION (arg), REALPART_EXPR, arg, 1);
3525           imag = build_unary_op (EXPR_LOCATION (arg), IMAGPART_EXPR, arg, 1);
3526           real = build_unary_op (EXPR_LOCATION (arg), code, real, 1);
3527           if (real == error_mark_node || imag == error_mark_node)
3528             return error_mark_node;
3529           ret = build2 (COMPLEX_EXPR, TREE_TYPE (arg),
3530                         real, imag);
3531           goto return_build_unary_op;
3532         }
3533
3534       /* Report invalid types.  */
3535
3536       if (typecode != POINTER_TYPE && typecode != FIXED_POINT_TYPE
3537           && typecode != INTEGER_TYPE && typecode != REAL_TYPE)
3538         {
3539           if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3540             error_at (location, "wrong type argument to increment");
3541           else
3542             error_at (location, "wrong type argument to decrement");
3543
3544           return error_mark_node;
3545         }
3546
3547       {
3548         tree inc;
3549
3550         argtype = TREE_TYPE (arg);
3551
3552         /* Compute the increment.  */
3553
3554         if (typecode == POINTER_TYPE)
3555           {
3556             /* If pointer target is an undefined struct,
3557                we just cannot know how to do the arithmetic.  */
3558             if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (argtype)))
3559               {
3560                 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3561                   error_at (location,
3562                             "increment of pointer to unknown structure");
3563                 else
3564                   error_at (location,
3565                             "decrement of pointer to unknown structure");
3566               }
3567             else if (TREE_CODE (TREE_TYPE (argtype)) == FUNCTION_TYPE
3568                      || TREE_CODE (TREE_TYPE (argtype)) == VOID_TYPE)
3569               {
3570                 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3571                   pedwarn (location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3572                            "wrong type argument to increment");
3573                 else
3574                   pedwarn (location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3575                            "wrong type argument to decrement");
3576               }
3577
3578             inc = c_size_in_bytes (TREE_TYPE (argtype));
3579             inc = fold_convert_loc (location, sizetype, inc);
3580           }
3581         else if (FRACT_MODE_P (TYPE_MODE (argtype)))
3582           {
3583             /* For signed fract types, we invert ++ to -- or
3584                -- to ++, and change inc from 1 to -1, because
3585                it is not possible to represent 1 in signed fract constants.
3586                For unsigned fract types, the result always overflows and
3587                we get an undefined (original) or the maximum value.  */
3588             if (code == PREINCREMENT_EXPR)
3589               code = PREDECREMENT_EXPR;
3590             else if (code == PREDECREMENT_EXPR)
3591               code = PREINCREMENT_EXPR;
3592             else if (code == POSTINCREMENT_EXPR)
3593               code = POSTDECREMENT_EXPR;
3594             else /* code == POSTDECREMENT_EXPR  */
3595               code = POSTINCREMENT_EXPR;
3596
3597             inc = integer_minus_one_node;
3598             inc = convert (argtype, inc);
3599           }
3600         else
3601           {
3602             inc = integer_one_node;
3603             inc = convert (argtype, inc);
3604           }
3605
3606         /* Report a read-only lvalue.  */
3607         if (TYPE_READONLY (argtype))
3608           {
3609             readonly_error (arg,
3610                             ((code == PREINCREMENT_EXPR
3611                               || code == POSTINCREMENT_EXPR)
3612                              ? lv_increment : lv_decrement));
3613             return error_mark_node;
3614           }
3615         else if (TREE_READONLY (arg))
3616           readonly_warning (arg,
3617                             ((code == PREINCREMENT_EXPR
3618                               || code == POSTINCREMENT_EXPR)
3619                              ? lv_increment : lv_decrement));
3620
3621         if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3622           val = boolean_increment (code, arg);
3623         else
3624           val = build2 (code, TREE_TYPE (arg), arg, inc);
3625         TREE_SIDE_EFFECTS (val) = 1;
3626         if (TREE_CODE (val) != code)
3627           TREE_NO_WARNING (val) = 1;
3628         ret = val;
3629         goto return_build_unary_op;
3630       }
3631
3632     case ADDR_EXPR:
3633       /* Note that this operation never does default_conversion.  */
3634
3635       /* The operand of unary '&' must be an lvalue (which excludes
3636          expressions of type void), or, in C99, the result of a [] or
3637          unary '*' operator.  */
3638       if (VOID_TYPE_P (TREE_TYPE (arg))
3639           && TYPE_QUALS (TREE_TYPE (arg)) == TYPE_UNQUALIFIED
3640           && (TREE_CODE (arg) != INDIRECT_REF
3641               || !flag_isoc99))
3642         pedwarn (location, 0, "taking address of expression of type %<void%>");
3643
3644       /* Let &* cancel out to simplify resulting code.  */
3645       if (TREE_CODE (arg) == INDIRECT_REF)
3646         {
3647           /* Don't let this be an lvalue.  */
3648           if (lvalue_p (TREE_OPERAND (arg, 0)))
3649             return non_lvalue_loc (location, TREE_OPERAND (arg, 0));
3650           ret = TREE_OPERAND (arg, 0);
3651           goto return_build_unary_op;
3652         }
3653
3654       /* For &x[y], return x+y */
3655       if (TREE_CODE (arg) == ARRAY_REF)
3656         {
3657           tree op0 = TREE_OPERAND (arg, 0);
3658           if (!c_mark_addressable (op0))
3659             return error_mark_node;
3660           return build_binary_op (location, PLUS_EXPR,
3661                                   (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE
3662                                    ? array_to_pointer_conversion (location,
3663                                                                   op0)
3664                                    : op0),
3665                                   TREE_OPERAND (arg, 1), 1);
3666         }
3667
3668       /* Anything not already handled and not a true memory reference
3669          or a non-lvalue array is an error.  */
3670       else if (typecode != FUNCTION_TYPE && !flag
3671                && !lvalue_or_else (arg, lv_addressof))
3672         return error_mark_node;
3673
3674       /* Move address operations inside C_MAYBE_CONST_EXPR to simplify
3675          folding later.  */
3676       if (TREE_CODE (arg) == C_MAYBE_CONST_EXPR)
3677         {
3678           tree inner = build_unary_op (location, code,
3679                                        C_MAYBE_CONST_EXPR_EXPR (arg), flag);
3680           ret = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (inner),
3681                         C_MAYBE_CONST_EXPR_PRE (arg), inner);
3682           gcc_assert (!C_MAYBE_CONST_EXPR_INT_OPERANDS (arg));
3683           C_MAYBE_CONST_EXPR_NON_CONST (ret)
3684             = C_MAYBE_CONST_EXPR_NON_CONST (arg);
3685           goto return_build_unary_op;
3686         }
3687
3688       /* Ordinary case; arg is a COMPONENT_REF or a decl.  */
3689       argtype = TREE_TYPE (arg);
3690
3691       /* If the lvalue is const or volatile, merge that into the type
3692          to which the address will point.  Note that you can't get a
3693          restricted pointer by taking the address of something, so we
3694          only have to deal with `const' and `volatile' here.  */
3695       if ((DECL_P (arg) || REFERENCE_CLASS_P (arg))
3696           && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg)))
3697           argtype = c_build_type_variant (argtype,
3698                                           TREE_READONLY (arg),
3699                                           TREE_THIS_VOLATILE (arg));
3700
3701       if (!c_mark_addressable (arg))
3702         return error_mark_node;
3703
3704       gcc_assert (TREE_CODE (arg) != COMPONENT_REF
3705                   || !DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)));
3706
3707       argtype = build_pointer_type (argtype);
3708
3709       /* ??? Cope with user tricks that amount to offsetof.  Delete this
3710          when we have proper support for integer constant expressions.  */
3711       val = get_base_address (arg);
3712       if (val && TREE_CODE (val) == INDIRECT_REF
3713           && TREE_CONSTANT (TREE_OPERAND (val, 0)))
3714         {
3715           tree op0 = fold_convert_loc (location, sizetype,
3716                                        fold_offsetof (arg, val)), op1;
3717
3718           op1 = fold_convert_loc (location, argtype, TREE_OPERAND (val, 0));
3719           ret = fold_build2_loc (location, POINTER_PLUS_EXPR, argtype, op1, op0);
3720           goto return_build_unary_op;
3721         }
3722
3723       val = build1 (ADDR_EXPR, argtype, arg);
3724
3725       ret = val;
3726       goto return_build_unary_op;
3727
3728     default:
3729       gcc_unreachable ();
3730     }
3731
3732   if (argtype == 0)
3733     argtype = TREE_TYPE (arg);
3734   if (TREE_CODE (arg) == INTEGER_CST)
3735     ret = (require_constant_value
3736            ? fold_build1_initializer_loc (location, code, argtype, arg)
3737            : fold_build1_loc (location, code, argtype, arg));
3738   else
3739     ret = build1 (code, argtype, arg);
3740  return_build_unary_op:
3741   gcc_assert (ret != error_mark_node);
3742   if (TREE_CODE (ret) == INTEGER_CST && !TREE_OVERFLOW (ret)
3743       && !(TREE_CODE (xarg) == INTEGER_CST && !TREE_OVERFLOW (xarg)))
3744     ret = build1 (NOP_EXPR, TREE_TYPE (ret), ret);
3745   else if (TREE_CODE (ret) != INTEGER_CST && int_operands)
3746     ret = note_integer_operands (ret);
3747   if (eptype)
3748     ret = build1 (EXCESS_PRECISION_EXPR, eptype, ret);
3749   protected_set_expr_location (ret, location);
3750   return ret;
3751 }
3752
3753 /* Return nonzero if REF is an lvalue valid for this language.
3754    Lvalues can be assigned, unless their type has TYPE_READONLY.
3755    Lvalues can have their address taken, unless they have C_DECL_REGISTER.  */
3756
3757 bool
3758 lvalue_p (const_tree ref)
3759 {
3760   const enum tree_code code = TREE_CODE (ref);
3761
3762   switch (code)
3763     {
3764     case REALPART_EXPR:
3765     case IMAGPART_EXPR:
3766     case COMPONENT_REF:
3767       return lvalue_p (TREE_OPERAND (ref, 0));
3768
3769     case C_MAYBE_CONST_EXPR:
3770       return lvalue_p (TREE_OPERAND (ref, 1));
3771
3772     case COMPOUND_LITERAL_EXPR:
3773     case STRING_CST:
3774       return 1;
3775
3776     case INDIRECT_REF:
3777     case ARRAY_REF:
3778     case VAR_DECL:
3779     case PARM_DECL:
3780     case RESULT_DECL:
3781     case ERROR_MARK:
3782       return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE
3783               && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE);
3784
3785     case BIND_EXPR:
3786       return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE;
3787
3788     default:
3789       return 0;
3790     }
3791 }
3792 \f
3793 /* Give an error for storing in something that is 'const'.  */
3794
3795 static void
3796 readonly_error (tree arg, enum lvalue_use use)
3797 {
3798   gcc_assert (use == lv_assign || use == lv_increment || use == lv_decrement
3799               || use == lv_asm);
3800   /* Using this macro rather than (for example) arrays of messages
3801      ensures that all the format strings are checked at compile
3802      time.  */
3803 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A)               \
3804                                    : (use == lv_increment ? (I)         \
3805                                    : (use == lv_decrement ? (D) : (AS))))
3806   if (TREE_CODE (arg) == COMPONENT_REF)
3807     {
3808       if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0))))
3809         readonly_error (TREE_OPERAND (arg, 0), use);
3810       else
3811         error (READONLY_MSG (G_("assignment of read-only member %qD"),
3812                              G_("increment of read-only member %qD"),
3813                              G_("decrement of read-only member %qD"),
3814                              G_("read-only member %qD used as %<asm%> output")),
3815                TREE_OPERAND (arg, 1));
3816     }
3817   else if (TREE_CODE (arg) == VAR_DECL)
3818     error (READONLY_MSG (G_("assignment of read-only variable %qD"),
3819                          G_("increment of read-only variable %qD"),
3820                          G_("decrement of read-only variable %qD"),
3821                          G_("read-only variable %qD used as %<asm%> output")),
3822            arg);
3823   else
3824     error (READONLY_MSG (G_("assignment of read-only location %qE"),
3825                          G_("increment of read-only location %qE"),
3826                          G_("decrement of read-only location %qE"),
3827                          G_("read-only location %qE used as %<asm%> output")),
3828            arg);
3829 }
3830
3831 /* Give a warning for storing in something that is read-only in GCC
3832    terms but not const in ISO C terms.  */
3833
3834 static void
3835 readonly_warning (tree arg, enum lvalue_use use)
3836 {
3837   switch (use)
3838     {
3839     case lv_assign:
3840       warning (0, "assignment of read-only location %qE", arg);
3841       break;
3842     case lv_increment:
3843       warning (0, "increment of read-only location %qE", arg);
3844       break;
3845     case lv_decrement:
3846       warning (0, "decrement of read-only location %qE", arg);
3847       break;
3848     default:
3849       gcc_unreachable ();
3850     }
3851   return;
3852 }
3853
3854
3855 /* Return nonzero if REF is an lvalue valid for this language;
3856    otherwise, print an error message and return zero.  USE says
3857    how the lvalue is being used and so selects the error message.  */
3858
3859 static int
3860 lvalue_or_else (const_tree ref, enum lvalue_use use)
3861 {
3862   int win = lvalue_p (ref);
3863
3864   if (!win)
3865     lvalue_error (use);
3866
3867   return win;
3868 }
3869 \f
3870 /* Mark EXP saying that we need to be able to take the
3871    address of it; it should not be allocated in a register.
3872    Returns true if successful.  */
3873
3874 bool
3875 c_mark_addressable (tree exp)
3876 {
3877   tree x = exp;
3878
3879   while (1)
3880     switch (TREE_CODE (x))
3881       {
3882       case COMPONENT_REF:
3883         if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1)))
3884           {
3885             error
3886               ("cannot take address of bit-field %qD", TREE_OPERAND (x, 1));
3887             return false;
3888           }
3889
3890         /* ... fall through ...  */
3891
3892       case ADDR_EXPR:
3893       case ARRAY_REF:
3894       case REALPART_EXPR:
3895       case IMAGPART_EXPR:
3896         x = TREE_OPERAND (x, 0);
3897         break;
3898
3899       case COMPOUND_LITERAL_EXPR:
3900       case CONSTRUCTOR:
3901         TREE_ADDRESSABLE (x) = 1;
3902         return true;
3903
3904       case VAR_DECL:
3905       case CONST_DECL:
3906       case PARM_DECL:
3907       case RESULT_DECL:
3908         if (C_DECL_REGISTER (x)
3909             && DECL_NONLOCAL (x))
3910           {
3911             if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3912               {
3913                 error
3914                   ("global register variable %qD used in nested function", x);
3915                 return false;
3916               }
3917             pedwarn (input_location, 0, "register variable %qD used in nested function", x);
3918           }
3919         else if (C_DECL_REGISTER (x))
3920           {
3921             if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3922               error ("address of global register variable %qD requested", x);
3923             else
3924               error ("address of register variable %qD requested", x);
3925             return false;
3926           }
3927
3928         /* drops in */
3929       case FUNCTION_DECL:
3930         TREE_ADDRESSABLE (x) = 1;
3931         /* drops out */
3932       default:
3933         return true;
3934     }
3935 }
3936 \f
3937 /* Convert EXPR to TYPE, warning about conversion problems with
3938    constants.  SEMANTIC_TYPE is the type this conversion would use
3939    without excess precision. If SEMANTIC_TYPE is NULL, this function
3940    is equivalent to convert_and_check. This function is a wrapper that
3941    handles conversions that may be different than
3942    the usual ones because of excess precision.  */
3943
3944 static tree
3945 ep_convert_and_check (tree type, tree expr, tree semantic_type)
3946 {
3947   if (TREE_TYPE (expr) == type)
3948     return expr;
3949
3950   if (!semantic_type)
3951     return convert_and_check (type, expr);
3952
3953   if (TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
3954       && TREE_TYPE (expr) != semantic_type)
3955     {
3956       /* For integers, we need to check the real conversion, not
3957          the conversion to the excess precision type.  */
3958       expr = convert_and_check (semantic_type, expr);
3959     }
3960   /* Result type is the excess precision type, which should be
3961      large enough, so do not check.  */
3962   return convert (type, expr);
3963 }
3964
3965 /* Build and return a conditional expression IFEXP ? OP1 : OP2.  If
3966    IFEXP_BCP then the condition is a call to __builtin_constant_p, and
3967    if folded to an integer constant then the unselected half may
3968    contain arbitrary operations not normally permitted in constant
3969    expressions.  Set the location of the expression to LOC.  */
3970
3971 tree
3972 build_conditional_expr (location_t colon_loc, tree ifexp, bool ifexp_bcp,
3973                         tree op1, tree op1_original_type, tree op2,
3974                         tree op2_original_type)
3975 {
3976   tree type1;
3977   tree type2;
3978   enum tree_code code1;
3979   enum tree_code code2;
3980   tree result_type = NULL;
3981   tree semantic_result_type = NULL;
3982   tree orig_op1 = op1, orig_op2 = op2;
3983   bool int_const, op1_int_operands, op2_int_operands, int_operands;
3984   bool ifexp_int_operands;
3985   tree ret;
3986   bool objc_ok;
3987
3988   op1_int_operands = EXPR_INT_CONST_OPERANDS (orig_op1);
3989   if (op1_int_operands)
3990     op1 = remove_c_maybe_const_expr (op1);
3991   op2_int_operands = EXPR_INT_CONST_OPERANDS (orig_op2);
3992   if (op2_int_operands)
3993     op2 = remove_c_maybe_const_expr (op2);
3994   ifexp_int_operands = EXPR_INT_CONST_OPERANDS (ifexp);
3995   if (ifexp_int_operands)
3996     ifexp = remove_c_maybe_const_expr (ifexp);
3997
3998   /* Promote both alternatives.  */
3999
4000   if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
4001     op1 = default_conversion (op1);
4002   if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE)
4003     op2 = default_conversion (op2);
4004
4005   if (TREE_CODE (ifexp) == ERROR_MARK
4006       || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK
4007       || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK)
4008     return error_mark_node;
4009
4010   type1 = TREE_TYPE (op1);
4011   code1 = TREE_CODE (type1);
4012   type2 = TREE_TYPE (op2);
4013   code2 = TREE_CODE (type2);
4014
4015   /* C90 does not permit non-lvalue arrays in conditional expressions.
4016      In C99 they will be pointers by now.  */
4017   if (code1 == ARRAY_TYPE || code2 == ARRAY_TYPE)
4018     {
4019       error_at (colon_loc, "non-lvalue array in conditional expression");
4020       return error_mark_node;
4021     }
4022
4023   objc_ok = objc_compare_types (type1, type2, -3, NULL_TREE);
4024
4025   if ((TREE_CODE (op1) == EXCESS_PRECISION_EXPR
4026        || TREE_CODE (op2) == EXCESS_PRECISION_EXPR)
4027       && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
4028           || code1 == COMPLEX_TYPE)
4029       && (code2 == INTEGER_TYPE || code2 == REAL_TYPE
4030           || code2 == COMPLEX_TYPE))
4031     {
4032       semantic_result_type = c_common_type (type1, type2);
4033       if (TREE_CODE (op1) == EXCESS_PRECISION_EXPR)
4034         {
4035           op1 = TREE_OPERAND (op1, 0);
4036           type1 = TREE_TYPE (op1);
4037           gcc_assert (TREE_CODE (type1) == code1);
4038         }
4039       if (TREE_CODE (op2) == EXCESS_PRECISION_EXPR)
4040         {
4041           op2 = TREE_OPERAND (op2, 0);
4042           type2 = TREE_TYPE (op2);
4043           gcc_assert (TREE_CODE (type2) == code2);
4044         }
4045     }
4046
4047   if (warn_cxx_compat)
4048     {
4049       tree t1 = op1_original_type ? op1_original_type : TREE_TYPE (orig_op1);
4050       tree t2 = op2_original_type ? op2_original_type : TREE_TYPE (orig_op2);
4051
4052       if (TREE_CODE (t1) == ENUMERAL_TYPE
4053           && TREE_CODE (t2) == ENUMERAL_TYPE
4054           && TYPE_MAIN_VARIANT (t1) != TYPE_MAIN_VARIANT (t2))
4055         warning_at (colon_loc, OPT_Wc___compat,
4056                     ("different enum types in conditional is "
4057                      "invalid in C++: %qT vs %qT"),
4058                     t1, t2);
4059     }
4060
4061   /* Quickly detect the usual case where op1 and op2 have the same type
4062      after promotion.  */
4063   if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2))
4064     {
4065       if (type1 == type2)
4066         result_type = type1;
4067       else
4068         result_type = TYPE_MAIN_VARIANT (type1);
4069     }
4070   else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE
4071             || code1 == COMPLEX_TYPE)
4072            && (code2 == INTEGER_TYPE || code2 == REAL_TYPE
4073                || code2 == COMPLEX_TYPE))
4074     {
4075       result_type = c_common_type (type1, type2);
4076
4077       /* If -Wsign-compare, warn here if type1 and type2 have
4078          different signedness.  We'll promote the signed to unsigned
4079          and later code won't know it used to be different.
4080          Do this check on the original types, so that explicit casts
4081          will be considered, but default promotions won't.  */
4082       if (c_inhibit_evaluation_warnings == 0)
4083         {
4084           int unsigned_op1 = TYPE_UNSIGNED (TREE_TYPE (orig_op1));
4085           int unsigned_op2 = TYPE_UNSIGNED (TREE_TYPE (orig_op2));
4086
4087           if (unsigned_op1 ^ unsigned_op2)
4088             {
4089               bool ovf;
4090
4091               /* Do not warn if the result type is signed, since the
4092                  signed type will only be chosen if it can represent
4093                  all the values of the unsigned type.  */
4094               if (!TYPE_UNSIGNED (result_type))
4095                 /* OK */;
4096               else
4097                 {
4098                   bool op1_maybe_const = true;
4099                   bool op2_maybe_const = true;
4100
4101                   /* Do not warn if the signed quantity is an
4102                      unsuffixed integer literal (or some static
4103                      constant expression involving such literals) and
4104                      it is non-negative.  This warning requires the
4105                      operands to be folded for best results, so do
4106                      that folding in this case even without
4107                      warn_sign_compare to avoid warning options
4108                      possibly affecting code generation.  */
4109                   c_inhibit_evaluation_warnings
4110                     += (ifexp == truthvalue_false_node);
4111                   op1 = c_fully_fold (op1, require_constant_value,
4112                                       &op1_maybe_const);
4113                   c_inhibit_evaluation_warnings
4114                     -= (ifexp == truthvalue_false_node);
4115
4116                   c_inhibit_evaluation_warnings
4117                     += (ifexp == truthvalue_true_node);
4118                   op2 = c_fully_fold (op2, require_constant_value,
4119                                       &op2_maybe_const);
4120                   c_inhibit_evaluation_warnings
4121                     -= (ifexp == truthvalue_true_node);
4122
4123                   if (warn_sign_compare)
4124                     {
4125                       if ((unsigned_op2
4126                            && tree_expr_nonnegative_warnv_p (op1, &ovf))
4127                           || (unsigned_op1
4128                               && tree_expr_nonnegative_warnv_p (op2, &ovf)))
4129                         /* OK */;
4130                       else
4131                         warning_at (colon_loc, OPT_Wsign_compare,
4132                                     ("signed and unsigned type in "
4133                                      "conditional expression"));
4134                     }
4135                   if (!op1_maybe_const || TREE_CODE (op1) != INTEGER_CST)
4136                     op1 = c_wrap_maybe_const (op1, !op1_maybe_const);
4137                   if (!op2_maybe_const || TREE_CODE (op2) != INTEGER_CST)
4138                     op2 = c_wrap_maybe_const (op2, !op2_maybe_const);
4139                 }
4140             }
4141         }
4142     }
4143   else if (code1 == VOID_TYPE || code2 == VOID_TYPE)
4144     {
4145       if (code1 != VOID_TYPE || code2 != VOID_TYPE)
4146         pedwarn (colon_loc, OPT_pedantic,
4147                  "ISO C forbids conditional expr with only one void side");
4148       result_type = void_type_node;
4149     }
4150   else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE)
4151     {
4152       addr_space_t as1 = TYPE_ADDR_SPACE (TREE_TYPE (type1));
4153       addr_space_t as2 = TYPE_ADDR_SPACE (TREE_TYPE (type2));
4154       addr_space_t as_common;
4155
4156       if (comp_target_types (colon_loc, type1, type2))
4157         result_type = common_pointer_type (type1, type2);
4158       else if (null_pointer_constant_p (orig_op1))
4159         result_type = type2;
4160       else if (null_pointer_constant_p (orig_op2))
4161         result_type = type1;
4162       else if (!addr_space_superset (as1, as2, &as_common))
4163         {
4164           error_at (colon_loc, "pointers to disjoint address spaces "
4165                     "used in conditional expression");
4166           return error_mark_node;
4167         }
4168       else if (VOID_TYPE_P (TREE_TYPE (type1)))
4169         {
4170           if (TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE)
4171             pedwarn (colon_loc, OPT_pedantic,
4172                      "ISO C forbids conditional expr between "
4173                      "%<void *%> and function pointer");
4174           result_type = build_pointer_type (qualify_type (TREE_TYPE (type1),
4175                                                           TREE_TYPE (type2)));
4176         }
4177       else if (VOID_TYPE_P (TREE_TYPE (type2)))
4178         {
4179           if (TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)
4180             pedwarn (colon_loc, OPT_pedantic,
4181                      "ISO C forbids conditional expr between "
4182                      "%<void *%> and function pointer");
4183           result_type = build_pointer_type (qualify_type (TREE_TYPE (type2),
4184                                                           TREE_TYPE (type1)));
4185         }
4186       else
4187         {
4188           int qual = ENCODE_QUAL_ADDR_SPACE (as_common);
4189
4190           if (!objc_ok)
4191             pedwarn (colon_loc, 0,
4192                      "pointer type mismatch in conditional expression");
4193           result_type = build_pointer_type
4194                           (build_qualified_type (void_type_node, qual));
4195         }
4196     }
4197   else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE)
4198     {
4199       if (!null_pointer_constant_p (orig_op2))
4200         pedwarn (colon_loc, 0,
4201                  "pointer/integer type mismatch in conditional expression");
4202       else
4203         {
4204           op2 = null_pointer_node;
4205         }
4206       result_type = type1;
4207     }
4208   else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE)
4209     {
4210       if (!null_pointer_constant_p (orig_op1))
4211         pedwarn (colon_loc, 0,
4212                  "pointer/integer type mismatch in conditional expression");
4213       else
4214         {
4215           op1 = null_pointer_node;
4216         }
4217       result_type = type2;
4218     }
4219
4220   if (!result_type)
4221     {
4222       if (flag_cond_mismatch)
4223         result_type = void_type_node;
4224       else
4225         {
4226           error_at (colon_loc, "type mismatch in conditional expression");
4227           return error_mark_node;
4228         }
4229     }
4230
4231   /* Merge const and volatile flags of the incoming types.  */
4232   result_type
4233     = build_type_variant (result_type,
4234                           TYPE_READONLY (type1) || TYPE_READONLY (type2),
4235                           TYPE_VOLATILE (type1) || TYPE_VOLATILE (type2));
4236
4237   op1 = ep_convert_and_check (result_type, op1, semantic_result_type);
4238   op2 = ep_convert_and_check (result_type, op2, semantic_result_type);
4239
4240   if (ifexp_bcp && ifexp == truthvalue_true_node)
4241     {
4242       op2_int_operands = true;
4243       op1 = c_fully_fold (op1, require_constant_value, NULL);
4244     }
4245   if (ifexp_bcp && ifexp == truthvalue_false_node)
4246     {
4247       op1_int_operands = true;
4248       op2 = c_fully_fold (op2, require_constant_value, NULL);
4249     }
4250   int_const = int_operands = (ifexp_int_operands
4251                               && op1_int_operands
4252                               && op2_int_operands);
4253   if (int_operands)
4254     {
4255       int_const = ((ifexp == truthvalue_true_node
4256                     && TREE_CODE (orig_op1) == INTEGER_CST
4257                     && !TREE_OVERFLOW (orig_op1))
4258                    || (ifexp == truthvalue_false_node
4259                        && TREE_CODE (orig_op2) == INTEGER_CST
4260                        && !TREE_OVERFLOW (orig_op2)));
4261     }
4262   if (int_const || (ifexp_bcp && TREE_CODE (ifexp) == INTEGER_CST))
4263     ret = fold_build3_loc (colon_loc, COND_EXPR, result_type, ifexp, op1, op2);
4264   else
4265     {
4266       ret = build3 (COND_EXPR, result_type, ifexp, op1, op2);
4267       if (int_operands)
4268         ret = note_integer_operands (ret);
4269     }
4270   if (semantic_result_type)
4271     ret = build1 (EXCESS_PRECISION_EXPR, semantic_result_type, ret);
4272
4273   protected_set_expr_location (ret, colon_loc);
4274   return ret;
4275 }
4276 \f
4277 /* Return a compound expression that performs two expressions and
4278    returns the value of the second of them.
4279
4280    LOC is the location of the COMPOUND_EXPR.  */
4281
4282 tree
4283 build_compound_expr (location_t loc, tree expr1, tree expr2)
4284 {
4285   bool expr1_int_operands, expr2_int_operands;
4286   tree eptype = NULL_TREE;
4287   tree ret;
4288
4289   expr1_int_operands = EXPR_INT_CONST_OPERANDS (expr1);
4290   if (expr1_int_operands)
4291     expr1 = remove_c_maybe_const_expr (expr1);
4292   expr2_int_operands = EXPR_INT_CONST_OPERANDS (expr2);
4293   if (expr2_int_operands)
4294     expr2 = remove_c_maybe_const_expr (expr2);
4295
4296   if (TREE_CODE (expr1) == EXCESS_PRECISION_EXPR)
4297     expr1 = TREE_OPERAND (expr1, 0);
4298   if (TREE_CODE (expr2) == EXCESS_PRECISION_EXPR)
4299     {
4300       eptype = TREE_TYPE (expr2);
4301       expr2 = TREE_OPERAND (expr2, 0);
4302     }
4303
4304   if (!TREE_SIDE_EFFECTS (expr1))
4305     {
4306       /* The left-hand operand of a comma expression is like an expression
4307          statement: with -Wunused, we should warn if it doesn't have
4308          any side-effects, unless it was explicitly cast to (void).  */
4309       if (warn_unused_value)
4310         {
4311           if (VOID_TYPE_P (TREE_TYPE (expr1))
4312               && CONVERT_EXPR_P (expr1))
4313             ; /* (void) a, b */
4314           else if (VOID_TYPE_P (TREE_TYPE (expr1))
4315                    && TREE_CODE (expr1) == COMPOUND_EXPR
4316                    && CONVERT_EXPR_P (TREE_OPERAND (expr1, 1)))
4317             ; /* (void) a, (void) b, c */
4318           else
4319             warning_at (loc, OPT_Wunused_value,
4320                         "left-hand operand of comma expression has no effect");
4321         }
4322     }
4323
4324   /* With -Wunused, we should also warn if the left-hand operand does have
4325      side-effects, but computes a value which is not used.  For example, in
4326      `foo() + bar(), baz()' the result of the `+' operator is not used,
4327      so we should issue a warning.  */
4328   else if (warn_unused_value)
4329     warn_if_unused_value (expr1, loc);
4330
4331   if (expr2 == error_mark_node)
4332     return error_mark_node;
4333
4334   ret = build2 (COMPOUND_EXPR, TREE_TYPE (expr2), expr1, expr2);
4335
4336   if (flag_isoc99
4337       && expr1_int_operands
4338       && expr2_int_operands)
4339     ret = note_integer_operands (ret);
4340
4341   if (eptype)
4342     ret = build1 (EXCESS_PRECISION_EXPR, eptype, ret);
4343
4344   protected_set_expr_location (ret, loc);
4345   return ret;
4346 }
4347
4348 /* Issue -Wcast-qual warnings when appropriate.  TYPE is the type to
4349    which we are casting.  OTYPE is the type of the expression being
4350    cast.  Both TYPE and OTYPE are pointer types.  -Wcast-qual appeared
4351    on the command line.  Named address space qualifiers are not handled
4352    here, because they result in different warnings.  */
4353
4354 static void
4355 handle_warn_cast_qual (tree type, tree otype)
4356 {
4357   tree in_type = type;
4358   tree in_otype = otype;
4359   int added = 0;
4360   int discarded = 0;
4361   bool is_const;
4362
4363   /* Check that the qualifiers on IN_TYPE are a superset of the
4364      qualifiers of IN_OTYPE.  The outermost level of POINTER_TYPE
4365      nodes is uninteresting and we stop as soon as we hit a
4366      non-POINTER_TYPE node on either type.  */
4367   do
4368     {
4369       in_otype = TREE_TYPE (in_otype);
4370       in_type = TREE_TYPE (in_type);
4371
4372       /* GNU C allows cv-qualified function types.  'const' means the
4373          function is very pure, 'volatile' means it can't return.  We
4374          need to warn when such qualifiers are added, not when they're
4375          taken away.  */
4376       if (TREE_CODE (in_otype) == FUNCTION_TYPE
4377           && TREE_CODE (in_type) == FUNCTION_TYPE)
4378         added |= (TYPE_QUALS_NO_ADDR_SPACE (in_type)
4379                   & ~TYPE_QUALS_NO_ADDR_SPACE (in_otype));
4380       else
4381         discarded |= (TYPE_QUALS_NO_ADDR_SPACE (in_otype)
4382                       & ~TYPE_QUALS_NO_ADDR_SPACE (in_type));
4383     }
4384   while (TREE_CODE (in_type) == POINTER_TYPE
4385          && TREE_CODE (in_otype) == POINTER_TYPE);
4386
4387   if (added)
4388     warning (OPT_Wcast_qual, "cast adds new qualifiers to function type");
4389
4390   if (discarded)
4391     /* There are qualifiers present in IN_OTYPE that are not present
4392        in IN_TYPE.  */
4393     warning (OPT_Wcast_qual,
4394              "cast discards qualifiers from pointer target type");
4395
4396   if (added || discarded)
4397     return;
4398
4399   /* A cast from **T to const **T is unsafe, because it can cause a
4400      const value to be changed with no additional warning.  We only
4401      issue this warning if T is the same on both sides, and we only
4402      issue the warning if there are the same number of pointers on
4403      both sides, as otherwise the cast is clearly unsafe anyhow.  A
4404      cast is unsafe when a qualifier is added at one level and const
4405      is not present at all outer levels.
4406
4407      To issue this warning, we check at each level whether the cast
4408      adds new qualifiers not already seen.  We don't need to special
4409      case function types, as they won't have the same
4410      TYPE_MAIN_VARIANT.  */
4411
4412   if (TYPE_MAIN_VARIANT (in_type) != TYPE_MAIN_VARIANT (in_otype))
4413     return;
4414   if (TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE)
4415     return;
4416
4417   in_type = type;
4418   in_otype = otype;
4419   is_const = TYPE_READONLY (TREE_TYPE (in_type));
4420   do
4421     {
4422       in_type = TREE_TYPE (in_type);
4423       in_otype = TREE_TYPE (in_otype);
4424       if ((TYPE_QUALS (in_type) &~ TYPE_QUALS (in_otype)) != 0
4425           && !is_const)
4426         {
4427           warning (OPT_Wcast_qual,
4428                    ("new qualifiers in middle of multi-level non-const cast "
4429                     "are unsafe"));
4430           break;
4431         }
4432       if (is_const)
4433         is_const = TYPE_READONLY (in_type);
4434     }
4435   while (TREE_CODE (in_type) == POINTER_TYPE);
4436 }
4437
4438 /* Build an expression representing a cast to type TYPE of expression EXPR.
4439    LOC is the location of the cast-- typically the open paren of the cast.  */
4440
4441 tree
4442 build_c_cast (location_t loc, tree type, tree expr)
4443 {
4444   tree value;
4445
4446   if (TREE_CODE (expr) == EXCESS_PRECISION_EXPR)
4447     expr = TREE_OPERAND (expr, 0);
4448
4449   value = expr;
4450
4451   if (type == error_mark_node || expr == error_mark_node)
4452     return error_mark_node;
4453
4454   /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
4455      only in <protocol> qualifications.  But when constructing cast expressions,
4456      the protocols do matter and must be kept around.  */
4457   if (objc_is_object_ptr (type) && objc_is_object_ptr (TREE_TYPE (expr)))
4458     return build1 (NOP_EXPR, type, expr);
4459
4460   type = TYPE_MAIN_VARIANT (type);
4461
4462   if (TREE_CODE (type) == ARRAY_TYPE)
4463     {
4464       error_at (loc, "cast specifies array type");
4465       return error_mark_node;
4466     }
4467
4468   if (TREE_CODE (type) == FUNCTION_TYPE)
4469     {
4470       error_at (loc, "cast specifies function type");
4471       return error_mark_node;
4472     }
4473
4474   if (!VOID_TYPE_P (type))
4475     {
4476       value = require_complete_type (value);
4477       if (value == error_mark_node)
4478         return error_mark_node;
4479     }
4480
4481   if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value)))
4482     {
4483       if (TREE_CODE (type) == RECORD_TYPE
4484           || TREE_CODE (type) == UNION_TYPE)
4485         pedwarn (loc, OPT_pedantic,
4486                  "ISO C forbids casting nonscalar to the same type");
4487     }
4488   else if (TREE_CODE (type) == UNION_TYPE)
4489     {
4490       tree field;
4491
4492       for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4493         if (TREE_TYPE (field) != error_mark_node
4494             && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)),
4495                           TYPE_MAIN_VARIANT (TREE_TYPE (value))))
4496           break;
4497
4498       if (field)
4499         {
4500           tree t;
4501           bool maybe_const = true;
4502
4503           pedwarn (loc, OPT_pedantic, "ISO C forbids casts to union type");
4504           t = c_fully_fold (value, false, &maybe_const);
4505           t = build_constructor_single (type, field, t);
4506           if (!maybe_const)
4507             t = c_wrap_maybe_const (t, true);
4508           t = digest_init (loc, type, t,
4509                            NULL_TREE, false, true, 0);
4510           TREE_CONSTANT (t) = TREE_CONSTANT (value);
4511           return t;
4512         }
4513       error_at (loc, "cast to union type from type not present in union");
4514       return error_mark_node;
4515     }
4516   else
4517     {
4518       tree otype, ovalue;
4519
4520       if (type == void_type_node)
4521         {
4522           tree t = build1 (CONVERT_EXPR, type, value);
4523           SET_EXPR_LOCATION (t, loc);
4524           return t;
4525         }
4526
4527       otype = TREE_TYPE (value);
4528
4529       /* Optionally warn about potentially worrisome casts.  */
4530       if (warn_cast_qual
4531           && TREE_CODE (type) == POINTER_TYPE
4532           && TREE_CODE (otype) == POINTER_TYPE)
4533         handle_warn_cast_qual (type, otype);
4534
4535       /* Warn about conversions between pointers to disjoint
4536          address spaces.  */
4537       if (TREE_CODE (type) == POINTER_TYPE
4538           && TREE_CODE (otype) == POINTER_TYPE
4539           && !null_pointer_constant_p (value))
4540         {
4541           addr_space_t as_to = TYPE_ADDR_SPACE (TREE_TYPE (type));
4542           addr_space_t as_from = TYPE_ADDR_SPACE (TREE_TYPE (otype));
4543           addr_space_t as_common;
4544
4545           if (!addr_space_superset (as_to, as_from, &as_common))
4546             {
4547               if (ADDR_SPACE_GENERIC_P (as_from))
4548                 warning_at (loc, 0, "cast to %s address space pointer "
4549                             "from disjoint generic address space pointer",
4550                             c_addr_space_name (as_to));
4551
4552               else if (ADDR_SPACE_GENERIC_P (as_to))
4553                 warning_at (loc, 0, "cast to generic address space pointer "
4554                             "from disjoint %s address space pointer",
4555                             c_addr_space_name (as_from));
4556
4557               else
4558                 warning_at (loc, 0, "cast to %s address space pointer "
4559                             "from disjoint %s address space pointer",
4560                             c_addr_space_name (as_to),
4561                             c_addr_space_name (as_from));
4562             }
4563         }
4564
4565       /* Warn about possible alignment problems.  */
4566       if (STRICT_ALIGNMENT
4567           && TREE_CODE (type) == POINTER_TYPE
4568           && TREE_CODE (otype) == POINTER_TYPE
4569           && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
4570           && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
4571           /* Don't warn about opaque types, where the actual alignment
4572              restriction is unknown.  */
4573           && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE
4574                 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE)
4575                && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode)
4576           && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
4577         warning_at (loc, OPT_Wcast_align,
4578                     "cast increases required alignment of target type");
4579
4580       if (TREE_CODE (type) == INTEGER_TYPE
4581           && TREE_CODE (otype) == POINTER_TYPE
4582           && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
4583       /* Unlike conversion of integers to pointers, where the
4584          warning is disabled for converting constants because
4585          of cases such as SIG_*, warn about converting constant
4586          pointers to integers. In some cases it may cause unwanted
4587          sign extension, and a warning is appropriate.  */
4588         warning_at (loc, OPT_Wpointer_to_int_cast,
4589                     "cast from pointer to integer of different size");
4590
4591       if (TREE_CODE (value) == CALL_EXPR
4592           && TREE_CODE (type) != TREE_CODE (otype))
4593         warning_at (loc, OPT_Wbad_function_cast,
4594                     "cast from function call of type %qT "
4595                     "to non-matching type %qT", otype, type);
4596
4597       if (TREE_CODE (type) == POINTER_TYPE
4598           && TREE_CODE (otype) == INTEGER_TYPE
4599           && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
4600           /* Don't warn about converting any constant.  */
4601           && !TREE_CONSTANT (value))
4602         warning_at (loc,
4603                     OPT_Wint_to_pointer_cast, "cast to pointer from integer "
4604                     "of different size");
4605
4606       if (warn_strict_aliasing <= 2)
4607         strict_aliasing_warning (otype, type, expr);
4608
4609       /* If pedantic, warn for conversions between function and object
4610          pointer types, except for converting a null pointer constant
4611          to function pointer type.  */
4612       if (pedantic
4613           && TREE_CODE (type) == POINTER_TYPE
4614           && TREE_CODE (otype) == POINTER_TYPE
4615           && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE
4616           && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE)
4617         pedwarn (loc, OPT_pedantic, "ISO C forbids "
4618                  "conversion of function pointer to object pointer type");
4619
4620       if (pedantic
4621           && TREE_CODE (type) == POINTER_TYPE
4622           && TREE_CODE (otype) == POINTER_TYPE
4623           && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
4624           && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
4625           && !null_pointer_constant_p (value))
4626         pedwarn (loc, OPT_pedantic, "ISO C forbids "
4627                  "conversion of object pointer to function pointer type");
4628
4629       ovalue = value;
4630       value = convert (type, value);
4631
4632       /* Ignore any integer overflow caused by the cast.  */
4633       if (TREE_CODE (value) == INTEGER_CST && !FLOAT_TYPE_P (otype))
4634         {
4635           if (CONSTANT_CLASS_P (ovalue) && TREE_OVERFLOW (ovalue))
4636             {
4637               if (!TREE_OVERFLOW (value))
4638                 {
4639                   /* Avoid clobbering a shared constant.  */
4640                   value = copy_node (value);
4641                   TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
4642                 }
4643             }
4644           else if (TREE_OVERFLOW (value))
4645             /* Reset VALUE's overflow flags, ensuring constant sharing.  */
4646             value = build_int_cst_wide (TREE_TYPE (value),
4647                                         TREE_INT_CST_LOW (value),
4648                                         TREE_INT_CST_HIGH (value));
4649         }
4650     }
4651
4652   /* Don't let a cast be an lvalue.  */
4653   if (value == expr)
4654     value = non_lvalue_loc (loc, value);
4655
4656   /* Don't allow the results of casting to floating-point or complex
4657      types be confused with actual constants, or casts involving
4658      integer and pointer types other than direct integer-to-integer
4659      and integer-to-pointer be confused with integer constant
4660      expressions and null pointer constants.  */
4661   if (TREE_CODE (value) == REAL_CST
4662       || TREE_CODE (value) == COMPLEX_CST
4663       || (TREE_CODE (value) == INTEGER_CST
4664           && !((TREE_CODE (expr) == INTEGER_CST
4665                 && INTEGRAL_TYPE_P (TREE_TYPE (expr)))
4666                || TREE_CODE (expr) == REAL_CST
4667                || TREE_CODE (expr) == COMPLEX_CST)))
4668       value = build1 (NOP_EXPR, type, value);
4669
4670   if (CAN_HAVE_LOCATION_P (value))
4671     SET_EXPR_LOCATION (value, loc);
4672   return value;
4673 }
4674
4675 /* Interpret a cast of expression EXPR to type TYPE.  LOC is the
4676    location of the open paren of the cast, or the position of the cast
4677    expr.  */
4678 tree
4679 c_cast_expr (location_t loc, struct c_type_name *type_name, tree expr)
4680 {
4681   tree type;
4682   tree type_expr = NULL_TREE;
4683   bool type_expr_const = true;
4684   tree ret;
4685   int saved_wsp = warn_strict_prototypes;
4686
4687   /* This avoids warnings about unprototyped casts on
4688      integers.  E.g. "#define SIG_DFL (void(*)())0".  */
4689   if (TREE_CODE (expr) == INTEGER_CST)
4690     warn_strict_prototypes = 0;
4691   type = groktypename (type_name, &type_expr, &type_expr_const);
4692   warn_strict_prototypes = saved_wsp;
4693
4694   ret = build_c_cast (loc, type, expr);
4695   if (type_expr)
4696     {
4697       ret = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (ret), type_expr, ret);
4698       C_MAYBE_CONST_EXPR_NON_CONST (ret) = !type_expr_const;
4699       SET_EXPR_LOCATION (ret, loc);
4700     }
4701
4702   if (CAN_HAVE_LOCATION_P (ret) && !EXPR_HAS_LOCATION (ret))
4703     SET_EXPR_LOCATION (ret, loc);
4704
4705   /* C++ does not permits types to be defined in a cast.  */
4706   if (warn_cxx_compat && type_name->specs->tag_defined_p)
4707     warning_at (loc, OPT_Wc___compat,
4708                 "defining a type in a cast is invalid in C++");
4709
4710   return ret;
4711 }
4712 \f
4713 /* Build an assignment expression of lvalue LHS from value RHS.
4714    If LHS_ORIGTYPE is not NULL, it is the original type of LHS, which
4715    may differ from TREE_TYPE (LHS) for an enum bitfield.
4716    MODIFYCODE is the code for a binary operator that we use
4717    to combine the old value of LHS with RHS to get the new value.
4718    Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
4719    If RHS_ORIGTYPE is not NULL_TREE, it is the original type of RHS,
4720    which may differ from TREE_TYPE (RHS) for an enum value.
4721
4722    LOCATION is the location of the MODIFYCODE operator.
4723    RHS_LOC is the location of the RHS.  */
4724
4725 tree
4726 build_modify_expr (location_t location, tree lhs, tree lhs_origtype,
4727                    enum tree_code modifycode,
4728                    location_t rhs_loc, tree rhs, tree rhs_origtype)
4729 {
4730   tree result;
4731   tree newrhs;
4732   tree rhs_semantic_type = NULL_TREE;
4733   tree lhstype = TREE_TYPE (lhs);
4734   tree olhstype = lhstype;
4735   bool npc;
4736
4737   /* Types that aren't fully specified cannot be used in assignments.  */
4738   lhs = require_complete_type (lhs);
4739
4740   /* Avoid duplicate error messages from operands that had errors.  */
4741   if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK)
4742     return error_mark_node;
4743
4744   if (!lvalue_or_else (lhs, lv_assign))
4745     return error_mark_node;
4746
4747   if (TREE_CODE (rhs) == EXCESS_PRECISION_EXPR)
4748     {
4749       rhs_semantic_type = TREE_TYPE (rhs);
4750       rhs = TREE_OPERAND (rhs, 0);
4751     }
4752
4753   newrhs = rhs;
4754
4755   if (TREE_CODE (lhs) == C_MAYBE_CONST_EXPR)
4756     {
4757       tree inner = build_modify_expr (location, C_MAYBE_CONST_EXPR_EXPR (lhs),
4758                                       lhs_origtype, modifycode, rhs_loc, rhs,
4759                                       rhs_origtype);
4760       if (inner == error_mark_node)
4761         return error_mark_node;
4762       result = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (inner),
4763                        C_MAYBE_CONST_EXPR_PRE (lhs), inner);
4764       gcc_assert (!C_MAYBE_CONST_EXPR_INT_OPERANDS (lhs));
4765       C_MAYBE_CONST_EXPR_NON_CONST (result) = 1;
4766       protected_set_expr_location (result, location);
4767       return result;
4768     }
4769
4770   /* If a binary op has been requested, combine the old LHS value with the RHS
4771      producing the value we should actually store into the LHS.  */
4772
4773   if (modifycode != NOP_EXPR)
4774     {
4775       lhs = c_fully_fold (lhs, false, NULL);
4776       lhs = stabilize_reference (lhs);
4777       newrhs = build_binary_op (location,
4778                                 modifycode, lhs, rhs, 1);
4779
4780       /* The original type of the right hand side is no longer
4781          meaningful.  */
4782       rhs_origtype = NULL_TREE;
4783     }
4784
4785   /* Give an error for storing in something that is 'const'.  */
4786
4787   if (TYPE_READONLY (lhstype)
4788       || ((TREE_CODE (lhstype) == RECORD_TYPE
4789            || TREE_CODE (lhstype) == UNION_TYPE)
4790           && C_TYPE_FIELDS_READONLY (lhstype)))
4791     {
4792       readonly_error (lhs, lv_assign);
4793       return error_mark_node;
4794     }
4795   else if (TREE_READONLY (lhs))
4796     readonly_warning (lhs, lv_assign);
4797
4798   /* If storing into a structure or union member,
4799      it has probably been given type `int'.
4800      Compute the type that would go with
4801      the actual amount of storage the member occupies.  */
4802
4803   if (TREE_CODE (lhs) == COMPONENT_REF
4804       && (TREE_CODE (lhstype) == INTEGER_TYPE
4805           || TREE_CODE (lhstype) == BOOLEAN_TYPE
4806           || TREE_CODE (lhstype) == REAL_TYPE
4807           || TREE_CODE (lhstype) == ENUMERAL_TYPE))
4808     lhstype = TREE_TYPE (get_unwidened (lhs, 0));
4809
4810   /* If storing in a field that is in actuality a short or narrower than one,
4811      we must store in the field in its actual type.  */
4812
4813   if (lhstype != TREE_TYPE (lhs))
4814     {
4815       lhs = copy_node (lhs);
4816       TREE_TYPE (lhs) = lhstype;
4817     }
4818
4819   /* Issue -Wc++-compat warnings about an assignment to an enum type
4820      when LHS does not have its original type.  This happens for,
4821      e.g., an enum bitfield in a struct.  */
4822   if (warn_cxx_compat
4823       && lhs_origtype != NULL_TREE
4824       && lhs_origtype != lhstype
4825       && TREE_CODE (lhs_origtype) == ENUMERAL_TYPE)
4826     {
4827       tree checktype = (rhs_origtype != NULL_TREE
4828                         ? rhs_origtype
4829                         : TREE_TYPE (rhs));
4830       if (checktype != error_mark_node
4831           && TYPE_MAIN_VARIANT (checktype) != TYPE_MAIN_VARIANT (lhs_origtype))
4832         warning_at (location, OPT_Wc___compat,
4833                     "enum conversion in assignment is invalid in C++");
4834     }
4835
4836   /* Convert new value to destination type.  Fold it first, then
4837      restore any excess precision information, for the sake of
4838      conversion warnings.  */
4839
4840   npc = null_pointer_constant_p (newrhs);
4841   newrhs = c_fully_fold (newrhs, false, NULL);
4842   if (rhs_semantic_type)
4843     newrhs = build1 (EXCESS_PRECISION_EXPR, rhs_semantic_type, newrhs);
4844   newrhs = convert_for_assignment (location, lhstype, newrhs, rhs_origtype,
4845                                    ic_assign, npc, NULL_TREE, NULL_TREE, 0);
4846   if (TREE_CODE (newrhs) == ERROR_MARK)
4847     return error_mark_node;
4848
4849   /* Emit ObjC write barrier, if necessary.  */
4850   if (c_dialect_objc () && flag_objc_gc)
4851     {
4852       result = objc_generate_write_barrier (lhs, modifycode, newrhs);
4853       if (result)
4854         {
4855           protected_set_expr_location (result, location);
4856           return result;
4857         }
4858     }
4859
4860   /* Scan operands.  */
4861
4862   result = build2 (MODIFY_EXPR, lhstype, lhs, newrhs);
4863   TREE_SIDE_EFFECTS (result) = 1;
4864   protected_set_expr_location (result, location);
4865
4866   /* If we got the LHS in a different type for storing in,
4867      convert the result back to the nominal type of LHS
4868      so that the value we return always has the same type
4869      as the LHS argument.  */
4870
4871   if (olhstype == TREE_TYPE (result))
4872     return result;
4873
4874   result = convert_for_assignment (location, olhstype, result, rhs_origtype,
4875                                    ic_assign, false, NULL_TREE, NULL_TREE, 0);
4876   protected_set_expr_location (result, location);
4877   return result;
4878 }
4879 \f
4880 /* Convert value RHS to type TYPE as preparation for an assignment to
4881    an lvalue of type TYPE.  If ORIGTYPE is not NULL_TREE, it is the
4882    original type of RHS; this differs from TREE_TYPE (RHS) for enum
4883    types.  NULL_POINTER_CONSTANT says whether RHS was a null pointer
4884    constant before any folding.
4885    The real work of conversion is done by `convert'.
4886    The purpose of this function is to generate error messages
4887    for assignments that are not allowed in C.
4888    ERRTYPE says whether it is argument passing, assignment,
4889    initialization or return.
4890
4891    LOCATION is the location of the RHS.
4892    FUNCTION is a tree for the function being called.
4893    PARMNUM is the number of the argument, for printing in error messages.  */
4894
4895 static tree
4896 convert_for_assignment (location_t location, tree type, tree rhs,
4897                         tree origtype, enum impl_conv errtype,
4898                         bool null_pointer_constant, tree fundecl,
4899                         tree function, int parmnum)
4900 {
4901   enum tree_code codel = TREE_CODE (type);
4902   tree orig_rhs = rhs;
4903   tree rhstype;
4904   enum tree_code coder;
4905   tree rname = NULL_TREE;
4906   bool objc_ok = false;
4907
4908   if (errtype == ic_argpass)
4909     {
4910       tree selector;
4911       /* Change pointer to function to the function itself for
4912          diagnostics.  */
4913       if (TREE_CODE (function) == ADDR_EXPR
4914           && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
4915         function = TREE_OPERAND (function, 0);
4916
4917       /* Handle an ObjC selector specially for diagnostics.  */
4918       selector = objc_message_selector ();
4919       rname = function;
4920       if (selector && parmnum > 2)
4921         {
4922           rname = selector;
4923           parmnum -= 2;
4924         }
4925     }
4926
4927   /* This macro is used to emit diagnostics to ensure that all format
4928      strings are complete sentences, visible to gettext and checked at
4929      compile time.  */
4930 #define WARN_FOR_ASSIGNMENT(LOCATION, OPT, AR, AS, IN, RE)               \
4931   do {                                                                   \
4932     switch (errtype)                                                     \
4933       {                                                                  \
4934       case ic_argpass:                                                   \
4935         if (pedwarn (LOCATION, OPT, AR, parmnum, rname))                 \
4936           inform ((fundecl && !DECL_IS_BUILTIN (fundecl))                \
4937                   ? DECL_SOURCE_LOCATION (fundecl) : LOCATION,           \
4938                   "expected %qT but argument is of type %qT",            \
4939                   type, rhstype);                                        \
4940         break;                                                           \
4941       case ic_assign:                                                    \
4942         pedwarn (LOCATION, OPT, AS);                                     \
4943         break;                                                           \
4944       case ic_init:                                                      \
4945         pedwarn (LOCATION, OPT, IN);                                     \
4946         break;                                                           \
4947       case ic_return:                                                    \
4948         pedwarn (LOCATION, OPT, RE);                                     \
4949         break;                                                           \
4950       default:                                                           \
4951         gcc_unreachable ();                                              \
4952       }                                                                  \
4953   } while (0)
4954
4955   if (TREE_CODE (rhs) == EXCESS_PRECISION_EXPR)
4956     rhs = TREE_OPERAND (rhs, 0);
4957
4958   rhstype = TREE_TYPE (rhs);
4959   coder = TREE_CODE (rhstype);
4960
4961   if (coder == ERROR_MARK)
4962     return error_mark_node;
4963
4964   if (c_dialect_objc ())
4965     {
4966       int parmno;
4967
4968       switch (errtype)
4969         {
4970         case ic_return:
4971           parmno = 0;
4972           break;
4973
4974         case ic_assign:
4975           parmno = -1;
4976           break;
4977
4978         case ic_init:
4979           parmno = -2;
4980           break;
4981
4982         default:
4983           parmno = parmnum;
4984           break;
4985         }
4986
4987       objc_ok = objc_compare_types (type, rhstype, parmno, rname);
4988     }
4989
4990   if (warn_cxx_compat)
4991     {
4992       tree checktype = origtype != NULL_TREE ? origtype : rhstype;
4993       if (checktype != error_mark_node
4994           && TREE_CODE (type) == ENUMERAL_TYPE
4995           && TYPE_MAIN_VARIANT (checktype) != TYPE_MAIN_VARIANT (type))
4996         {
4997           WARN_FOR_ASSIGNMENT (input_location, OPT_Wc___compat,
4998                                G_("enum conversion when passing argument "
4999                                   "%d of %qE is invalid in C++"),
5000                                G_("enum conversion in assignment is "
5001                                   "invalid in C++"),
5002                                G_("enum conversion in initialization is "
5003                                   "invalid in C++"),
5004                                G_("enum conversion in return is "
5005                                   "invalid in C++"));
5006         }
5007     }
5008
5009   if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype))
5010     return rhs;
5011
5012   if (coder == VOID_TYPE)
5013     {
5014       /* Except for passing an argument to an unprototyped function,
5015          this is a constraint violation.  When passing an argument to
5016          an unprototyped function, it is compile-time undefined;
5017          making it a constraint in that case was rejected in
5018          DR#252.  */
5019       error_at (location, "void value not ignored as it ought to be");
5020       return error_mark_node;
5021     }
5022   rhs = require_complete_type (rhs);
5023   if (rhs == error_mark_node)
5024     return error_mark_node;
5025   /* A type converts to a reference to it.
5026      This code doesn't fully support references, it's just for the
5027      special case of va_start and va_copy.  */
5028   if (codel == REFERENCE_TYPE
5029       && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1)
5030     {
5031       if (!lvalue_p (rhs))
5032         {
5033           error_at (location, "cannot pass rvalue to reference parameter");
5034           return error_mark_node;
5035         }
5036       if (!c_mark_addressable (rhs))
5037         return error_mark_node;
5038       rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs);
5039       SET_EXPR_LOCATION (rhs, location);
5040
5041       /* We already know that these two types are compatible, but they
5042          may not be exactly identical.  In fact, `TREE_TYPE (type)' is
5043          likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
5044          likely to be va_list, a typedef to __builtin_va_list, which
5045          is different enough that it will cause problems later.  */
5046       if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type))
5047         {
5048           rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs);
5049           SET_EXPR_LOCATION (rhs, location);
5050         }
5051
5052       rhs = build1 (NOP_EXPR, type, rhs);
5053       SET_EXPR_LOCATION (rhs, location);
5054       return rhs;
5055     }
5056   /* Some types can interconvert without explicit casts.  */
5057   else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE
5058            && vector_types_convertible_p (type, TREE_TYPE (rhs), true))
5059     return convert (type, rhs);
5060   /* Arithmetic types all interconvert, and enum is treated like int.  */
5061   else if ((codel == INTEGER_TYPE || codel == REAL_TYPE
5062             || codel == FIXED_POINT_TYPE
5063             || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE
5064             || codel == BOOLEAN_TYPE)
5065            && (coder == INTEGER_TYPE || coder == REAL_TYPE
5066                || coder == FIXED_POINT_TYPE
5067                || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE
5068                || coder == BOOLEAN_TYPE))
5069     {
5070       tree ret;
5071       bool save = in_late_binary_op;
5072       if (codel == BOOLEAN_TYPE)
5073         in_late_binary_op = true;
5074       ret = convert_and_check (type, orig_rhs);
5075       if (codel == BOOLEAN_TYPE)
5076         in_late_binary_op = save;
5077       return ret;
5078     }
5079
5080   /* Aggregates in different TUs might need conversion.  */
5081   if ((codel == RECORD_TYPE || codel == UNION_TYPE)
5082       && codel == coder
5083       && comptypes (type, rhstype))
5084     return convert_and_check (type, rhs);
5085
5086   /* Conversion to a transparent union or record from its member types.
5087      This applies only to function arguments.  */
5088   if (((codel == UNION_TYPE || codel == RECORD_TYPE)
5089       && TYPE_TRANSPARENT_AGGR (type))
5090       && errtype == ic_argpass)
5091     {
5092       tree memb, marginal_memb = NULL_TREE;
5093
5094       for (memb = TYPE_FIELDS (type); memb ; memb = TREE_CHAIN (memb))
5095         {
5096           tree memb_type = TREE_TYPE (memb);
5097
5098           if (comptypes (TYPE_MAIN_VARIANT (memb_type),
5099                          TYPE_MAIN_VARIANT (rhstype)))
5100             break;
5101
5102           if (TREE_CODE (memb_type) != POINTER_TYPE)
5103             continue;
5104
5105           if (coder == POINTER_TYPE)
5106             {
5107               tree ttl = TREE_TYPE (memb_type);
5108               tree ttr = TREE_TYPE (rhstype);
5109
5110               /* Any non-function converts to a [const][volatile] void *
5111                  and vice versa; otherwise, targets must be the same.
5112                  Meanwhile, the lhs target must have all the qualifiers of
5113                  the rhs.  */
5114               if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
5115                   || comp_target_types (location, memb_type, rhstype))
5116                 {
5117                   /* If this type won't generate any warnings, use it.  */
5118                   if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr)
5119                       || ((TREE_CODE (ttr) == FUNCTION_TYPE
5120                            && TREE_CODE (ttl) == FUNCTION_TYPE)
5121                           ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
5122                              == TYPE_QUALS (ttr))
5123                           : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
5124                              == TYPE_QUALS (ttl))))
5125                     break;
5126
5127                   /* Keep looking for a better type, but remember this one.  */
5128                   if (!marginal_memb)
5129                     marginal_memb = memb;
5130                 }
5131             }
5132
5133           /* Can convert integer zero to any pointer type.  */
5134           if (null_pointer_constant)
5135             {
5136               rhs = null_pointer_node;
5137               break;
5138             }
5139         }
5140
5141       if (memb || marginal_memb)
5142         {
5143           if (!memb)
5144             {
5145               /* We have only a marginally acceptable member type;
5146                  it needs a warning.  */
5147               tree ttl = TREE_TYPE (TREE_TYPE (marginal_memb));
5148               tree ttr = TREE_TYPE (rhstype);
5149
5150               /* Const and volatile mean something different for function
5151                  types, so the usual warnings are not appropriate.  */
5152               if (TREE_CODE (ttr) == FUNCTION_TYPE
5153                   && TREE_CODE (ttl) == FUNCTION_TYPE)
5154                 {
5155                   /* Because const and volatile on functions are
5156                      restrictions that say the function will not do
5157                      certain things, it is okay to use a const or volatile
5158                      function where an ordinary one is wanted, but not
5159                      vice-versa.  */
5160                   if (TYPE_QUALS_NO_ADDR_SPACE (ttl)
5161                       & ~TYPE_QUALS_NO_ADDR_SPACE (ttr))
5162                     WARN_FOR_ASSIGNMENT (location, 0,
5163                                          G_("passing argument %d of %qE "
5164                                             "makes qualified function "
5165                                             "pointer from unqualified"),
5166                                          G_("assignment makes qualified "
5167                                             "function pointer from "
5168                                             "unqualified"),
5169                                          G_("initialization makes qualified "
5170                                             "function pointer from "
5171                                             "unqualified"),
5172                                          G_("return makes qualified function "
5173                                             "pointer from unqualified"));
5174                 }
5175               else if (TYPE_QUALS_NO_ADDR_SPACE (ttr)
5176                        & ~TYPE_QUALS_NO_ADDR_SPACE (ttl))
5177                 WARN_FOR_ASSIGNMENT (location, 0,
5178                                      G_("passing argument %d of %qE discards "
5179                                         "qualifiers from pointer target type"),
5180                                      G_("assignment discards qualifiers "
5181                                         "from pointer target type"),
5182                                      G_("initialization discards qualifiers "
5183                                         "from pointer target type"),
5184                                      G_("return discards qualifiers from "
5185                                         "pointer target type"));
5186
5187               memb = marginal_memb;
5188             }
5189
5190           if (!fundecl || !DECL_IN_SYSTEM_HEADER (fundecl))
5191             pedwarn (location, OPT_pedantic,
5192                      "ISO C prohibits argument conversion to union type");
5193
5194           rhs = fold_convert_loc (location, TREE_TYPE (memb), rhs);
5195           return build_constructor_single (type, memb, rhs);
5196         }
5197     }
5198
5199   /* Conversions among pointers */
5200   else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
5201            && (coder == codel))
5202     {
5203       tree ttl = TREE_TYPE (type);
5204       tree ttr = TREE_TYPE (rhstype);
5205       tree mvl = ttl;
5206       tree mvr = ttr;
5207       bool is_opaque_pointer;
5208       int target_cmp = 0;   /* Cache comp_target_types () result.  */
5209       addr_space_t asl;
5210       addr_space_t asr;
5211
5212       if (TREE_CODE (mvl) != ARRAY_TYPE)
5213         mvl = TYPE_MAIN_VARIANT (mvl);
5214       if (TREE_CODE (mvr) != ARRAY_TYPE)
5215         mvr = TYPE_MAIN_VARIANT (mvr);
5216       /* Opaque pointers are treated like void pointers.  */
5217       is_opaque_pointer = vector_targets_convertible_p (ttl, ttr);
5218
5219       /* C++ does not allow the implicit conversion void* -> T*.  However,
5220          for the purpose of reducing the number of false positives, we
5221          tolerate the special case of
5222
5223                 int *p = NULL;
5224
5225          where NULL is typically defined in C to be '(void *) 0'.  */
5226       if (VOID_TYPE_P (ttr) && rhs != null_pointer_node && !VOID_TYPE_P (ttl))
5227         warning_at (location, OPT_Wc___compat,
5228                     "request for implicit conversion "
5229                     "from %qT to %qT not permitted in C++", rhstype, type);
5230
5231       /* See if the pointers point to incompatible address spaces.  */
5232       asl = TYPE_ADDR_SPACE (ttl);
5233       asr = TYPE_ADDR_SPACE (ttr);
5234       if (!null_pointer_constant_p (rhs)
5235           && asr != asl && !targetm.addr_space.subset_p (asr, asl))
5236         {
5237           switch (errtype)
5238             {
5239             case ic_argpass:
5240               error_at (location, "passing argument %d of %qE from pointer to "
5241                         "non-enclosed address space", parmnum, rname);
5242               break;
5243             case ic_assign:
5244               error_at (location, "assignment from pointer to "
5245                         "non-enclosed address space");
5246               break;
5247             case ic_init:
5248               error_at (location, "initialization from pointer to "
5249                         "non-enclosed address space");
5250               break;
5251             case ic_return:
5252               error_at (location, "return from pointer to "
5253                         "non-enclosed address space");
5254               break;
5255             default:
5256               gcc_unreachable ();
5257             }
5258           return error_mark_node;
5259         }
5260
5261       /* Check if the right-hand side has a format attribute but the
5262          left-hand side doesn't.  */
5263       if (warn_missing_format_attribute
5264           && check_missing_format_attribute (type, rhstype))
5265         {
5266           switch (errtype)
5267           {
5268           case ic_argpass:
5269             warning_at (location, OPT_Wmissing_format_attribute,
5270                         "argument %d of %qE might be "
5271                         "a candidate for a format attribute",
5272                         parmnum, rname);
5273             break;
5274           case ic_assign:
5275             warning_at (location, OPT_Wmissing_format_attribute,
5276                         "assignment left-hand side might be "
5277                         "a candidate for a format attribute");
5278             break;
5279           case ic_init:
5280             warning_at (location, OPT_Wmissing_format_attribute,
5281                         "initialization left-hand side might be "
5282                         "a candidate for a format attribute");
5283             break;
5284           case ic_return:
5285             warning_at (location, OPT_Wmissing_format_attribute,
5286                         "return type might be "
5287                         "a candidate for a format attribute");
5288             break;
5289           default:
5290             gcc_unreachable ();
5291           }
5292         }
5293
5294       /* Any non-function converts to a [const][volatile] void *
5295          and vice versa; otherwise, targets must be the same.
5296          Meanwhile, the lhs target must have all the qualifiers of the rhs.  */
5297       if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
5298           || (target_cmp = comp_target_types (location, type, rhstype))
5299           || is_opaque_pointer
5300           || (c_common_unsigned_type (mvl)
5301               == c_common_unsigned_type (mvr)))
5302         {
5303           if (pedantic
5304               && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE)
5305                   ||
5306                   (VOID_TYPE_P (ttr)
5307                    && !null_pointer_constant
5308                    && TREE_CODE (ttl) == FUNCTION_TYPE)))
5309             WARN_FOR_ASSIGNMENT (location, OPT_pedantic,
5310                                  G_("ISO C forbids passing argument %d of "
5311                                     "%qE between function pointer "
5312                                     "and %<void *%>"),
5313                                  G_("ISO C forbids assignment between "
5314                                     "function pointer and %<void *%>"),
5315                                  G_("ISO C forbids initialization between "
5316                                     "function pointer and %<void *%>"),
5317                                  G_("ISO C forbids return between function "
5318                                     "pointer and %<void *%>"));
5319           /* Const and volatile mean something different for function types,
5320              so the usual warnings are not appropriate.  */
5321           else if (TREE_CODE (ttr) != FUNCTION_TYPE
5322                    && TREE_CODE (ttl) != FUNCTION_TYPE)
5323             {
5324               if (TYPE_QUALS_NO_ADDR_SPACE (ttr)
5325                   & ~TYPE_QUALS_NO_ADDR_SPACE (ttl))
5326                 {
5327                   /* Types differing only by the presence of the 'volatile'
5328                      qualifier are acceptable if the 'volatile' has been added
5329                      in by the Objective-C EH machinery.  */
5330                   if (!objc_type_quals_match (ttl, ttr))
5331                     WARN_FOR_ASSIGNMENT (location, 0,
5332                                          G_("passing argument %d of %qE discards "
5333                                             "qualifiers from pointer target type"),
5334                                          G_("assignment discards qualifiers "
5335                                             "from pointer target type"),
5336                                          G_("initialization discards qualifiers "
5337                                             "from pointer target type"),
5338                                          G_("return discards qualifiers from "
5339                                             "pointer target type"));
5340                 }
5341               /* If this is not a case of ignoring a mismatch in signedness,
5342                  no warning.  */
5343               else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
5344                        || target_cmp)
5345                 ;
5346               /* If there is a mismatch, do warn.  */
5347               else if (warn_pointer_sign)
5348                 WARN_FOR_ASSIGNMENT (location, OPT_Wpointer_sign,
5349                                      G_("pointer targets in passing argument "
5350                                         "%d of %qE differ in signedness"),
5351                                      G_("pointer targets in assignment "
5352                                         "differ in signedness"),
5353                                      G_("pointer targets in initialization "
5354                                         "differ in signedness"),
5355                                      G_("pointer targets in return differ "
5356                                         "in signedness"));
5357             }
5358           else if (TREE_CODE (ttl) == FUNCTION_TYPE
5359                    && TREE_CODE (ttr) == FUNCTION_TYPE)
5360             {
5361               /* Because const and volatile on functions are restrictions
5362                  that say the function will not do certain things,
5363                  it is okay to use a const or volatile function
5364                  where an ordinary one is wanted, but not vice-versa.  */
5365               if (TYPE_QUALS_NO_ADDR_SPACE (ttl)
5366                   & ~TYPE_QUALS_NO_ADDR_SPACE (ttr))
5367                 WARN_FOR_ASSIGNMENT (location, 0,
5368                                      G_("passing argument %d of %qE makes "
5369                                         "qualified function pointer "
5370                                         "from unqualified"),
5371                                      G_("assignment makes qualified function "
5372                                         "pointer from unqualified"),
5373                                      G_("initialization makes qualified "
5374                                         "function pointer from unqualified"),
5375                                      G_("return makes qualified function "
5376                                         "pointer from unqualified"));
5377             }
5378         }
5379       else
5380         /* Avoid warning about the volatile ObjC EH puts on decls.  */
5381         if (!objc_ok)
5382           WARN_FOR_ASSIGNMENT (location, 0,
5383                                G_("passing argument %d of %qE from "
5384                                   "incompatible pointer type"),
5385                                G_("assignment from incompatible pointer type"),
5386                                G_("initialization from incompatible "
5387                                   "pointer type"),
5388                                G_("return from incompatible pointer type"));
5389
5390       return convert (type, rhs);
5391     }
5392   else if (codel == POINTER_TYPE && coder == ARRAY_TYPE)
5393     {
5394       /* ??? This should not be an error when inlining calls to
5395          unprototyped functions.  */
5396       error_at (location, "invalid use of non-lvalue array");
5397       return error_mark_node;
5398     }
5399   else if (codel == POINTER_TYPE && coder == INTEGER_TYPE)
5400     {
5401       /* An explicit constant 0 can convert to a pointer,
5402          or one that results from arithmetic, even including
5403          a cast to integer type.  */
5404       if (!null_pointer_constant)
5405         WARN_FOR_ASSIGNMENT (location, 0,
5406                              G_("passing argument %d of %qE makes "
5407                                 "pointer from integer without a cast"),
5408                              G_("assignment makes pointer from integer "
5409                                 "without a cast"),
5410                              G_("initialization makes pointer from "
5411                                 "integer without a cast"),
5412                              G_("return makes pointer from integer "
5413                                 "without a cast"));
5414
5415       return convert (type, rhs);
5416     }
5417   else if (codel == INTEGER_TYPE && coder == POINTER_TYPE)
5418     {
5419       WARN_FOR_ASSIGNMENT (location, 0,
5420                            G_("passing argument %d of %qE makes integer "
5421                               "from pointer without a cast"),
5422                            G_("assignment makes integer from pointer "
5423                               "without a cast"),
5424                            G_("initialization makes integer from pointer "
5425                               "without a cast"),
5426                            G_("return makes integer from pointer "
5427                               "without a cast"));
5428       return convert (type, rhs);
5429     }
5430   else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE)
5431     {
5432       tree ret;
5433       bool save = in_late_binary_op;
5434       in_late_binary_op = true;
5435       ret = convert (type, rhs);
5436       in_late_binary_op = save;
5437       return ret;
5438     }
5439
5440   switch (errtype)
5441     {
5442     case ic_argpass:
5443       error_at (location, "incompatible type for argument %d of %qE", parmnum, rname);
5444       inform ((fundecl && !DECL_IS_BUILTIN (fundecl))
5445               ? DECL_SOURCE_LOCATION (fundecl) : input_location,
5446               "expected %qT but argument is of type %qT", type, rhstype);
5447       break;
5448     case ic_assign:
5449       error_at (location, "incompatible types when assigning to type %qT from "
5450                 "type %qT", type, rhstype);
5451       break;
5452     case ic_init:
5453       error_at (location,
5454                 "incompatible types when initializing type %qT using type %qT",
5455                 type, rhstype);
5456       break;
5457     case ic_return:
5458       error_at (location,
5459                 "incompatible types when returning type %qT but %qT was "
5460                 "expected", rhstype, type);
5461       break;
5462     default:
5463       gcc_unreachable ();
5464     }
5465
5466   return error_mark_node;
5467 }
5468 \f
5469 /* If VALUE is a compound expr all of whose expressions are constant, then
5470    return its value.  Otherwise, return error_mark_node.
5471
5472    This is for handling COMPOUND_EXPRs as initializer elements
5473    which is allowed with a warning when -pedantic is specified.  */
5474
5475 static tree
5476 valid_compound_expr_initializer (tree value, tree endtype)
5477 {
5478   if (TREE_CODE (value) == COMPOUND_EXPR)
5479     {
5480       if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype)
5481           == error_mark_node)
5482         return error_mark_node;
5483       return valid_compound_expr_initializer (TREE_OPERAND (value, 1),
5484                                               endtype);
5485     }
5486   else if (!initializer_constant_valid_p (value, endtype))
5487     return error_mark_node;
5488   else
5489     return value;
5490 }
5491 \f
5492 /* Perform appropriate conversions on the initial value of a variable,
5493    store it in the declaration DECL,
5494    and print any error messages that are appropriate.
5495    If ORIGTYPE is not NULL_TREE, it is the original type of INIT.
5496    If the init is invalid, store an ERROR_MARK.
5497
5498    INIT_LOC is the location of the initial value.  */
5499
5500 void
5501 store_init_value (location_t init_loc, tree decl, tree init, tree origtype)
5502 {
5503   tree value, type;
5504   bool npc = false;
5505
5506   /* If variable's type was invalidly declared, just ignore it.  */
5507
5508   type = TREE_TYPE (decl);
5509   if (TREE_CODE (type) == ERROR_MARK)
5510     return;
5511
5512   /* Digest the specified initializer into an expression.  */
5513
5514   if (init)
5515     npc = null_pointer_constant_p (init);
5516   value = digest_init (init_loc, type, init, origtype, npc,
5517                        true, TREE_STATIC (decl));
5518
5519   /* Store the expression if valid; else report error.  */
5520
5521   if (!in_system_header
5522       && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && !TREE_STATIC (decl))
5523     warning (OPT_Wtraditional, "traditional C rejects automatic "
5524              "aggregate initialization");
5525
5526   DECL_INITIAL (decl) = value;
5527
5528   /* ANSI wants warnings about out-of-range constant initializers.  */
5529   STRIP_TYPE_NOPS (value);
5530   if (TREE_STATIC (decl))
5531     constant_expression_warning (value);
5532
5533   /* Check if we need to set array size from compound literal size.  */
5534   if (TREE_CODE (type) == ARRAY_TYPE
5535       && TYPE_DOMAIN (type) == 0
5536       && value != error_mark_node)
5537     {
5538       tree inside_init = init;
5539
5540       STRIP_TYPE_NOPS (inside_init);
5541       inside_init = fold (inside_init);
5542
5543       if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
5544         {
5545           tree cldecl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
5546
5547           if (TYPE_DOMAIN (TREE_TYPE (cldecl)))
5548             {
5549               /* For int foo[] = (int [3]){1}; we need to set array size
5550                  now since later on array initializer will be just the
5551                  brace enclosed list of the compound literal.  */
5552               type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
5553               TREE_TYPE (decl) = type;
5554               TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (cldecl));
5555               layout_type (type);
5556               layout_decl (cldecl, 0);
5557             }
5558         }
5559     }
5560 }
5561 \f
5562 /* Methods for storing and printing names for error messages.  */
5563
5564 /* Implement a spelling stack that allows components of a name to be pushed
5565    and popped.  Each element on the stack is this structure.  */
5566
5567 struct spelling
5568 {
5569   int kind;
5570   union
5571     {
5572       unsigned HOST_WIDE_INT i;
5573       const char *s;
5574     } u;
5575 };
5576
5577 #define SPELLING_STRING 1
5578 #define SPELLING_MEMBER 2
5579 #define SPELLING_BOUNDS 3
5580
5581 static struct spelling *spelling;       /* Next stack element (unused).  */
5582 static struct spelling *spelling_base;  /* Spelling stack base.  */
5583 static int spelling_size;               /* Size of the spelling stack.  */
5584
5585 /* Macros to save and restore the spelling stack around push_... functions.
5586    Alternative to SAVE_SPELLING_STACK.  */
5587
5588 #define SPELLING_DEPTH() (spelling - spelling_base)
5589 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
5590
5591 /* Push an element on the spelling stack with type KIND and assign VALUE
5592    to MEMBER.  */
5593
5594 #define PUSH_SPELLING(KIND, VALUE, MEMBER)                              \
5595 {                                                                       \
5596   int depth = SPELLING_DEPTH ();                                        \
5597                                                                         \
5598   if (depth >= spelling_size)                                           \
5599     {                                                                   \
5600       spelling_size += 10;                                              \
5601       spelling_base = XRESIZEVEC (struct spelling, spelling_base,       \
5602                                   spelling_size);                       \
5603       RESTORE_SPELLING_DEPTH (depth);                                   \
5604     }                                                                   \
5605                                                                         \
5606   spelling->kind = (KIND);                                              \
5607   spelling->MEMBER = (VALUE);                                           \
5608   spelling++;                                                           \
5609 }
5610
5611 /* Push STRING on the stack.  Printed literally.  */
5612
5613 static void
5614 push_string (const char *string)
5615 {
5616   PUSH_SPELLING (SPELLING_STRING, string, u.s);
5617 }
5618
5619 /* Push a member name on the stack.  Printed as '.' STRING.  */
5620
5621 static void
5622 push_member_name (tree decl)
5623 {
5624   const char *const string
5625     = (DECL_NAME (decl)
5626        ? identifier_to_locale (IDENTIFIER_POINTER (DECL_NAME (decl)))
5627        : _("<anonymous>"));
5628   PUSH_SPELLING (SPELLING_MEMBER, string, u.s);
5629 }
5630
5631 /* Push an array bounds on the stack.  Printed as [BOUNDS].  */
5632
5633 static void
5634 push_array_bounds (unsigned HOST_WIDE_INT bounds)
5635 {
5636   PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i);
5637 }
5638
5639 /* Compute the maximum size in bytes of the printed spelling.  */
5640
5641 static int
5642 spelling_length (void)
5643 {
5644   int size = 0;
5645   struct spelling *p;
5646
5647   for (p = spelling_base; p < spelling; p++)
5648     {
5649       if (p->kind == SPELLING_BOUNDS)
5650         size += 25;
5651       else
5652         size += strlen (p->u.s) + 1;
5653     }
5654
5655   return size;
5656 }
5657
5658 /* Print the spelling to BUFFER and return it.  */
5659
5660 static char *
5661 print_spelling (char *buffer)
5662 {
5663   char *d = buffer;
5664   struct spelling *p;
5665
5666   for (p = spelling_base; p < spelling; p++)
5667     if (p->kind == SPELLING_BOUNDS)
5668       {
5669         sprintf (d, "[" HOST_WIDE_INT_PRINT_UNSIGNED "]", p->u.i);
5670         d += strlen (d);
5671       }
5672     else
5673       {
5674         const char *s;
5675         if (p->kind == SPELLING_MEMBER)
5676           *d++ = '.';
5677         for (s = p->u.s; (*d = *s++); d++)
5678           ;
5679       }
5680   *d++ = '\0';
5681   return buffer;
5682 }
5683
5684 /* Issue an error message for a bad initializer component.
5685    MSGID identifies the message.
5686    The component name is taken from the spelling stack.  */
5687
5688 void
5689 error_init (const char *msgid)
5690 {
5691   char *ofwhat;
5692
5693   error ("%s", _(msgid));
5694   ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
5695   if (*ofwhat)
5696     error ("(near initialization for %qs)", ofwhat);
5697 }
5698
5699 /* Issue a pedantic warning for a bad initializer component.  OPT is
5700    the option OPT_* (from options.h) controlling this warning or 0 if
5701    it is unconditionally given.  MSGID identifies the message.  The
5702    component name is taken from the spelling stack.  */
5703
5704 void
5705 pedwarn_init (location_t location, int opt, const char *msgid)
5706 {
5707   char *ofwhat;
5708
5709   pedwarn (location, opt, "%s", _(msgid));
5710   ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
5711   if (*ofwhat)
5712     pedwarn (location, opt, "(near initialization for %qs)", ofwhat);
5713 }
5714
5715 /* Issue a warning for a bad initializer component.
5716
5717    OPT is the OPT_W* value corresponding to the warning option that
5718    controls this warning.  MSGID identifies the message.  The
5719    component name is taken from the spelling stack.  */
5720
5721 static void
5722 warning_init (int opt, const char *msgid)
5723 {
5724   char *ofwhat;
5725
5726   warning (opt, "%s", _(msgid));
5727   ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
5728   if (*ofwhat)
5729     warning (opt, "(near initialization for %qs)", ofwhat);
5730 }
5731 \f
5732 /* If TYPE is an array type and EXPR is a parenthesized string
5733    constant, warn if pedantic that EXPR is being used to initialize an
5734    object of type TYPE.  */
5735
5736 void
5737 maybe_warn_string_init (tree type, struct c_expr expr)
5738 {
5739   if (pedantic
5740       && TREE_CODE (type) == ARRAY_TYPE
5741       && TREE_CODE (expr.value) == STRING_CST
5742       && expr.original_code != STRING_CST)
5743     pedwarn_init (input_location, OPT_pedantic,
5744                   "array initialized from parenthesized string constant");
5745 }
5746
5747 /* Digest the parser output INIT as an initializer for type TYPE.
5748    Return a C expression of type TYPE to represent the initial value.
5749
5750    If ORIGTYPE is not NULL_TREE, it is the original type of INIT.
5751
5752    NULL_POINTER_CONSTANT is true if INIT is a null pointer constant.
5753
5754    If INIT is a string constant, STRICT_STRING is true if it is
5755    unparenthesized or we should not warn here for it being parenthesized.
5756    For other types of INIT, STRICT_STRING is not used.
5757
5758    INIT_LOC is the location of the INIT.
5759
5760    REQUIRE_CONSTANT requests an error if non-constant initializers or
5761    elements are seen.  */
5762
5763 static tree
5764 digest_init (location_t init_loc, tree type, tree init, tree origtype,
5765              bool null_pointer_constant, bool strict_string,
5766              int require_constant)
5767 {
5768   enum tree_code code = TREE_CODE (type);
5769   tree inside_init = init;
5770   tree semantic_type = NULL_TREE;
5771   bool maybe_const = true;
5772
5773   if (type == error_mark_node
5774       || !init
5775       || init == error_mark_node
5776       || TREE_TYPE (init) == error_mark_node)
5777     return error_mark_node;
5778
5779   STRIP_TYPE_NOPS (inside_init);
5780
5781   if (TREE_CODE (inside_init) == EXCESS_PRECISION_EXPR)
5782     {
5783       semantic_type = TREE_TYPE (inside_init);
5784       inside_init = TREE_OPERAND (inside_init, 0);
5785     }
5786   inside_init = c_fully_fold (inside_init, require_constant, &maybe_const);
5787   inside_init = decl_constant_value_for_optimization (inside_init);
5788
5789   /* Initialization of an array of chars from a string constant
5790      optionally enclosed in braces.  */
5791
5792   if (code == ARRAY_TYPE && inside_init
5793       && TREE_CODE (inside_init) == STRING_CST)
5794     {
5795       tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
5796       /* Note that an array could be both an array of character type
5797          and an array of wchar_t if wchar_t is signed char or unsigned
5798          char.  */
5799       bool char_array = (typ1 == char_type_node
5800                          || typ1 == signed_char_type_node
5801                          || typ1 == unsigned_char_type_node);
5802       bool wchar_array = !!comptypes (typ1, wchar_type_node);
5803       bool char16_array = !!comptypes (typ1, char16_type_node);
5804       bool char32_array = !!comptypes (typ1, char32_type_node);
5805
5806       if (char_array || wchar_array || char16_array || char32_array)
5807         {
5808           struct c_expr expr;
5809           tree typ2 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init)));
5810           expr.value = inside_init;
5811           expr.original_code = (strict_string ? STRING_CST : ERROR_MARK);
5812           expr.original_type = NULL;
5813           maybe_warn_string_init (type, expr);
5814
5815           if (TYPE_DOMAIN (type) && !TYPE_MAX_VALUE (TYPE_DOMAIN (type)))
5816             pedwarn_init (init_loc, OPT_pedantic,
5817                           "initialization of a flexible array member");
5818
5819           if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
5820                          TYPE_MAIN_VARIANT (type)))
5821             return inside_init;
5822
5823           if (char_array)
5824             {
5825               if (typ2 != char_type_node)
5826                 {
5827                   error_init ("char-array initialized from wide string");
5828                   return error_mark_node;
5829                 }
5830             }
5831           else
5832             {
5833               if (typ2 == char_type_node)
5834                 {
5835                   error_init ("wide character array initialized from non-wide "
5836                               "string");
5837                   return error_mark_node;
5838                 }
5839               else if (!comptypes(typ1, typ2))
5840                 {
5841                   error_init ("wide character array initialized from "
5842                               "incompatible wide string");
5843                   return error_mark_node;
5844                 }
5845             }
5846
5847           TREE_TYPE (inside_init) = type;
5848           if (TYPE_DOMAIN (type) != 0
5849               && TYPE_SIZE (type) != 0
5850               && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST)
5851             {
5852               unsigned HOST_WIDE_INT len = TREE_STRING_LENGTH (inside_init);
5853
5854               /* Subtract the size of a single (possibly wide) character
5855                  because it's ok to ignore the terminating null char
5856                  that is counted in the length of the constant.  */
5857               if (0 > compare_tree_int (TYPE_SIZE_UNIT (type),
5858                                         (len
5859                                          - (TYPE_PRECISION (typ1)
5860                                             / BITS_PER_UNIT))))
5861                 pedwarn_init (init_loc, 0,
5862                               ("initializer-string for array of chars "
5863                                "is too long"));
5864               else if (warn_cxx_compat
5865                        && 0 > compare_tree_int (TYPE_SIZE_UNIT (type), len))
5866                 warning_at (init_loc, OPT_Wc___compat,
5867                             ("initializer-string for array chars "
5868                              "is too long for C++"));
5869             }
5870
5871           return inside_init;
5872         }
5873       else if (INTEGRAL_TYPE_P (typ1))
5874         {
5875           error_init ("array of inappropriate type initialized "
5876                       "from string constant");
5877           return error_mark_node;
5878         }
5879     }
5880
5881   /* Build a VECTOR_CST from a *constant* vector constructor.  If the
5882      vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
5883      below and handle as a constructor.  */
5884   if (code == VECTOR_TYPE
5885       && TREE_CODE (TREE_TYPE (inside_init)) == VECTOR_TYPE
5886       && vector_types_convertible_p (TREE_TYPE (inside_init), type, true)
5887       && TREE_CONSTANT (inside_init))
5888     {
5889       if (TREE_CODE (inside_init) == VECTOR_CST
5890           && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
5891                         TYPE_MAIN_VARIANT (type)))
5892         return inside_init;
5893
5894       if (TREE_CODE (inside_init) == CONSTRUCTOR)
5895         {
5896           unsigned HOST_WIDE_INT ix;
5897           tree value;
5898           bool constant_p = true;
5899
5900           /* Iterate through elements and check if all constructor
5901              elements are *_CSTs.  */
5902           FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (inside_init), ix, value)
5903             if (!CONSTANT_CLASS_P (value))
5904               {
5905                 constant_p = false;
5906                 break;
5907               }
5908
5909           if (constant_p)
5910             return build_vector_from_ctor (type,
5911                                            CONSTRUCTOR_ELTS (inside_init));
5912         }
5913     }
5914
5915   if (warn_sequence_point)
5916     verify_sequence_points (inside_init);
5917
5918   /* Any type can be initialized
5919      from an expression of the same type, optionally with braces.  */
5920
5921   if (inside_init && TREE_TYPE (inside_init) != 0
5922       && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
5923                      TYPE_MAIN_VARIANT (type))
5924           || (code == ARRAY_TYPE
5925               && comptypes (TREE_TYPE (inside_init), type))
5926           || (code == VECTOR_TYPE
5927               && comptypes (TREE_TYPE (inside_init), type))
5928           || (code == POINTER_TYPE
5929               && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE
5930               && comptypes (TREE_TYPE (TREE_TYPE (inside_init)),
5931                             TREE_TYPE (type)))))
5932     {
5933       if (code == POINTER_TYPE)
5934         {
5935           if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE)
5936             {
5937               if (TREE_CODE (inside_init) == STRING_CST
5938                   || TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
5939                 inside_init = array_to_pointer_conversion
5940                   (init_loc, inside_init);
5941               else
5942                 {
5943                   error_init ("invalid use of non-lvalue array");
5944                   return error_mark_node;
5945                 }
5946             }
5947         }
5948
5949       if (code == VECTOR_TYPE)
5950         /* Although the types are compatible, we may require a
5951            conversion.  */
5952         inside_init = convert (type, inside_init);
5953
5954       if (require_constant
5955           && (code == VECTOR_TYPE || !flag_isoc99)
5956           && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
5957         {
5958           /* As an extension, allow initializing objects with static storage
5959              duration with compound literals (which are then treated just as
5960              the brace enclosed list they contain).  Also allow this for
5961              vectors, as we can only assign them with compound literals.  */
5962           tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
5963           inside_init = DECL_INITIAL (decl);
5964         }
5965
5966       if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST
5967           && TREE_CODE (inside_init) != CONSTRUCTOR)
5968         {
5969           error_init ("array initialized from non-constant array expression");
5970           return error_mark_node;
5971         }
5972
5973       /* Compound expressions can only occur here if -pedantic or
5974          -pedantic-errors is specified.  In the later case, we always want
5975          an error.  In the former case, we simply want a warning.  */
5976       if (require_constant && pedantic
5977           && TREE_CODE (inside_init) == COMPOUND_EXPR)
5978         {
5979           inside_init
5980             = valid_compound_expr_initializer (inside_init,
5981                                                TREE_TYPE (inside_init));
5982           if (inside_init == error_mark_node)
5983             error_init ("initializer element is not constant");
5984           else
5985             pedwarn_init (init_loc, OPT_pedantic,
5986                           "initializer element is not constant");
5987           if (flag_pedantic_errors)
5988             inside_init = error_mark_node;
5989         }
5990       else if (require_constant
5991                && !initializer_constant_valid_p (inside_init,
5992                                                  TREE_TYPE (inside_init)))
5993         {
5994           error_init ("initializer element is not constant");
5995           inside_init = error_mark_node;
5996         }
5997       else if (require_constant && !maybe_const)
5998         pedwarn_init (init_loc, 0,
5999                       "initializer element is not a constant expression");
6000
6001       /* Added to enable additional -Wmissing-format-attribute warnings.  */
6002       if (TREE_CODE (TREE_TYPE (inside_init)) == POINTER_TYPE)
6003         inside_init = convert_for_assignment (init_loc, type, inside_init,
6004                                               origtype,
6005                                               ic_init, null_pointer_constant,
6006                                               NULL_TREE, NULL_TREE, 0);
6007       return inside_init;
6008     }
6009
6010   /* Handle scalar types, including conversions.  */
6011
6012   if (code == INTEGER_TYPE || code == REAL_TYPE || code == FIXED_POINT_TYPE
6013       || code == POINTER_TYPE || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE
6014       || code == COMPLEX_TYPE || code == VECTOR_TYPE)
6015     {
6016       if (TREE_CODE (TREE_TYPE (init)) == ARRAY_TYPE
6017           && (TREE_CODE (init) == STRING_CST
6018               || TREE_CODE (init) == COMPOUND_LITERAL_EXPR))
6019         inside_init = init = array_to_pointer_conversion (init_loc, init);
6020       if (semantic_type)
6021         inside_init = build1 (EXCESS_PRECISION_EXPR, semantic_type,
6022                               inside_init);
6023       inside_init
6024         = convert_for_assignment (init_loc, type, inside_init, origtype,
6025                                   ic_init, null_pointer_constant,
6026                                   NULL_TREE, NULL_TREE, 0);
6027
6028       /* Check to see if we have already given an error message.  */
6029       if (inside_init == error_mark_node)
6030         ;
6031       else if (require_constant && !TREE_CONSTANT (inside_init))
6032         {
6033           error_init ("initializer element is not constant");
6034           inside_init = error_mark_node;
6035         }
6036       else if (require_constant
6037                && !initializer_constant_valid_p (inside_init,
6038                                                  TREE_TYPE (inside_init)))
6039         {
6040           error_init ("initializer element is not computable at load time");
6041           inside_init = error_mark_node;
6042         }
6043       else if (require_constant && !maybe_const)
6044         pedwarn_init (init_loc, 0,
6045                       "initializer element is not a constant expression");
6046
6047       return inside_init;
6048     }
6049
6050   /* Come here only for records and arrays.  */
6051
6052   if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
6053     {
6054       error_init ("variable-sized object may not be initialized");
6055       return error_mark_node;
6056     }
6057
6058   error_init ("invalid initializer");
6059   return error_mark_node;
6060 }
6061 \f
6062 /* Handle initializers that use braces.  */
6063
6064 /* Type of object we are accumulating a constructor for.
6065    This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE.  */
6066 static tree constructor_type;
6067
6068 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
6069    left to fill.  */
6070 static tree constructor_fields;
6071
6072 /* For an ARRAY_TYPE, this is the specified index
6073    at which to store the next element we get.  */
6074 static tree constructor_index;
6075
6076 /* For an ARRAY_TYPE, this is the maximum index.  */
6077 static tree constructor_max_index;
6078
6079 /* For a RECORD_TYPE, this is the first field not yet written out.  */
6080 static tree constructor_unfilled_fields;
6081
6082 /* For an ARRAY_TYPE, this is the index of the first element
6083    not yet written out.  */
6084 static tree constructor_unfilled_index;
6085
6086 /* In a RECORD_TYPE, the byte index of the next consecutive field.
6087    This is so we can generate gaps between fields, when appropriate.  */
6088 static tree constructor_bit_index;
6089
6090 /* If we are saving up the elements rather than allocating them,
6091    this is the list of elements so far (in reverse order,
6092    most recent first).  */
6093 static VEC(constructor_elt,gc) *constructor_elements;
6094
6095 /* 1 if constructor should be incrementally stored into a constructor chain,
6096    0 if all the elements should be kept in AVL tree.  */
6097 static int constructor_incremental;
6098
6099 /* 1 if so far this constructor's elements are all compile-time constants.  */
6100 static int constructor_constant;
6101
6102 /* 1 if so far this constructor's elements are all valid address constants.  */
6103 static int constructor_simple;
6104
6105 /* 1 if this constructor has an element that cannot be part of a
6106    constant expression.  */
6107 static int constructor_nonconst;
6108
6109 /* 1 if this constructor is erroneous so far.  */
6110 static int constructor_erroneous;
6111
6112 /* Structure for managing pending initializer elements, organized as an
6113    AVL tree.  */
6114
6115 struct init_node
6116 {
6117   struct init_node *left, *right;
6118   struct init_node *parent;
6119   int balance;
6120   tree purpose;
6121   tree value;
6122   tree origtype;
6123 };
6124
6125 /* Tree of pending elements at this constructor level.
6126    These are elements encountered out of order
6127    which belong at places we haven't reached yet in actually
6128    writing the output.
6129    Will never hold tree nodes across GC runs.  */
6130 static struct init_node *constructor_pending_elts;
6131
6132 /* The SPELLING_DEPTH of this constructor.  */
6133 static int constructor_depth;
6134
6135 /* DECL node for which an initializer is being read.
6136    0 means we are reading a constructor expression
6137    such as (struct foo) {...}.  */
6138 static tree constructor_decl;
6139
6140 /* Nonzero if this is an initializer for a top-level decl.  */
6141 static int constructor_top_level;
6142
6143 /* Nonzero if there were any member designators in this initializer.  */
6144 static int constructor_designated;
6145
6146 /* Nesting depth of designator list.  */
6147 static int designator_depth;
6148
6149 /* Nonzero if there were diagnosed errors in this designator list.  */
6150 static int designator_erroneous;
6151
6152 \f
6153 /* This stack has a level for each implicit or explicit level of
6154    structuring in the initializer, including the outermost one.  It
6155    saves the values of most of the variables above.  */
6156
6157 struct constructor_range_stack;
6158
6159 struct constructor_stack
6160 {
6161   struct constructor_stack *next;
6162   tree type;
6163   tree fields;
6164   tree index;
6165   tree max_index;
6166   tree unfilled_index;
6167   tree unfilled_fields;
6168   tree bit_index;
6169   VEC(constructor_elt,gc) *elements;
6170   struct init_node *pending_elts;
6171   int offset;
6172   int depth;
6173   /* If value nonzero, this value should replace the entire
6174      constructor at this level.  */
6175   struct c_expr replacement_value;
6176   struct constructor_range_stack *range_stack;
6177   char constant;
6178   char simple;
6179   char nonconst;
6180   char implicit;
6181   char erroneous;
6182   char outer;
6183   char incremental;
6184   char designated;
6185 };
6186
6187 static struct constructor_stack *constructor_stack;
6188
6189 /* This stack represents designators from some range designator up to
6190    the last designator in the list.  */
6191
6192 struct constructor_range_stack
6193 {
6194   struct constructor_range_stack *next, *prev;
6195   struct constructor_stack *stack;
6196   tree range_start;
6197   tree index;
6198   tree range_end;
6199   tree fields;
6200 };
6201
6202 static struct constructor_range_stack *constructor_range_stack;
6203
6204 /* This stack records separate initializers that are nested.
6205    Nested initializers can't happen in ANSI C, but GNU C allows them
6206    in cases like { ... (struct foo) { ... } ... }.  */
6207
6208 struct initializer_stack
6209 {
6210   struct initializer_stack *next;
6211   tree decl;
6212   struct constructor_stack *constructor_stack;
6213   struct constructor_range_stack *constructor_range_stack;
6214   VEC(constructor_elt,gc) *elements;
6215   struct spelling *spelling;
6216   struct spelling *spelling_base;
6217   int spelling_size;
6218   char top_level;
6219   char require_constant_value;
6220   char require_constant_elements;
6221 };
6222
6223 static struct initializer_stack *initializer_stack;
6224 \f
6225 /* Prepare to parse and output the initializer for variable DECL.  */
6226
6227 void
6228 start_init (tree decl, tree asmspec_tree ATTRIBUTE_UNUSED, int top_level)
6229 {
6230   const char *locus;
6231   struct initializer_stack *p = XNEW (struct initializer_stack);
6232
6233   p->decl = constructor_decl;
6234   p->require_constant_value = require_constant_value;
6235   p->require_constant_elements = require_constant_elements;
6236   p->constructor_stack = constructor_stack;
6237   p->constructor_range_stack = constructor_range_stack;
6238   p->elements = constructor_elements;
6239   p->spelling = spelling;
6240   p->spelling_base = spelling_base;
6241   p->spelling_size = spelling_size;
6242   p->top_level = constructor_top_level;
6243   p->next = initializer_stack;
6244   initializer_stack = p;
6245
6246   constructor_decl = decl;
6247   constructor_designated = 0;
6248   constructor_top_level = top_level;
6249
6250   if (decl != 0 && decl != error_mark_node)
6251     {
6252       require_constant_value = TREE_STATIC (decl);
6253       require_constant_elements
6254         = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99))
6255            /* For a scalar, you can always use any value to initialize,
6256               even within braces.  */
6257            && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
6258                || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
6259                || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
6260                || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE));
6261       locus = identifier_to_locale (IDENTIFIER_POINTER (DECL_NAME (decl)));
6262     }
6263   else
6264     {
6265       require_constant_value = 0;
6266       require_constant_elements = 0;
6267       locus = _("(anonymous)");
6268     }
6269
6270   constructor_stack = 0;
6271   constructor_range_stack = 0;
6272
6273   missing_braces_mentioned = 0;
6274
6275   spelling_base = 0;
6276   spelling_size = 0;
6277   RESTORE_SPELLING_DEPTH (0);
6278
6279   if (locus)
6280     push_string (locus);
6281 }
6282
6283 void
6284 finish_init (void)
6285 {
6286   struct initializer_stack *p = initializer_stack;
6287
6288   /* Free the whole constructor stack of this initializer.  */
6289   while (constructor_stack)
6290     {
6291       struct constructor_stack *q = constructor_stack;
6292       constructor_stack = q->next;
6293       free (q);
6294     }
6295
6296   gcc_assert (!constructor_range_stack);
6297
6298   /* Pop back to the data of the outer initializer (if any).  */
6299   free (spelling_base);
6300
6301   constructor_decl = p->decl;
6302   require_constant_value = p->require_constant_value;
6303   require_constant_elements = p->require_constant_elements;
6304   constructor_stack = p->constructor_stack;
6305   constructor_range_stack = p->constructor_range_stack;
6306   constructor_elements = p->elements;
6307   spelling = p->spelling;
6308   spelling_base = p->spelling_base;
6309   spelling_size = p->spelling_size;
6310   constructor_top_level = p->top_level;
6311   initializer_stack = p->next;
6312   free (p);
6313 }
6314 \f
6315 /* Call here when we see the initializer is surrounded by braces.
6316    This is instead of a call to push_init_level;
6317    it is matched by a call to pop_init_level.
6318
6319    TYPE is the type to initialize, for a constructor expression.
6320    For an initializer for a decl, TYPE is zero.  */
6321
6322 void
6323 really_start_incremental_init (tree type)
6324 {
6325   struct constructor_stack *p = XNEW (struct constructor_stack);
6326
6327   if (type == 0)
6328     type = TREE_TYPE (constructor_decl);
6329
6330   if (TREE_CODE (type) == VECTOR_TYPE
6331       && TYPE_VECTOR_OPAQUE (type))
6332     error ("opaque vector types cannot be initialized");
6333
6334   p->type = constructor_type;
6335   p->fields = constructor_fields;
6336   p->index = constructor_index;
6337   p->max_index = constructor_max_index;
6338   p->unfilled_index = constructor_unfilled_index;
6339   p->unfilled_fields = constructor_unfilled_fields;
6340   p->bit_index = constructor_bit_index;
6341   p->elements = constructor_elements;
6342   p->constant = constructor_constant;
6343   p->simple = constructor_simple;
6344   p->nonconst = constructor_nonconst;
6345   p->erroneous = constructor_erroneous;
6346   p->pending_elts = constructor_pending_elts;
6347   p->depth = constructor_depth;
6348   p->replacement_value.value = 0;
6349   p->replacement_value.original_code = ERROR_MARK;
6350   p->replacement_value.original_type = NULL;
6351   p->implicit = 0;
6352   p->range_stack = 0;
6353   p->outer = 0;
6354   p->incremental = constructor_incremental;
6355   p->designated = constructor_designated;
6356   p->next = 0;
6357   constructor_stack = p;
6358
6359   constructor_constant = 1;
6360   constructor_simple = 1;
6361   constructor_nonconst = 0;
6362   constructor_depth = SPELLING_DEPTH ();
6363   constructor_elements = 0;
6364   constructor_pending_elts = 0;
6365   constructor_type = type;
6366   constructor_incremental = 1;
6367   constructor_designated = 0;
6368   designator_depth = 0;
6369   designator_erroneous = 0;
6370
6371   if (TREE_CODE (constructor_type) == RECORD_TYPE
6372       || TREE_CODE (constructor_type) == UNION_TYPE)
6373     {
6374       constructor_fields = TYPE_FIELDS (constructor_type);
6375       /* Skip any nameless bit fields at the beginning.  */
6376       while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
6377              && DECL_NAME (constructor_fields) == 0)
6378         constructor_fields = TREE_CHAIN (constructor_fields);
6379
6380       constructor_unfilled_fields = constructor_fields;
6381       constructor_bit_index = bitsize_zero_node;
6382     }
6383   else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6384     {
6385       if (TYPE_DOMAIN (constructor_type))
6386         {
6387           constructor_max_index
6388             = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
6389
6390           /* Detect non-empty initializations of zero-length arrays.  */
6391           if (constructor_max_index == NULL_TREE
6392               && TYPE_SIZE (constructor_type))
6393             constructor_max_index = build_int_cst (NULL_TREE, -1);
6394
6395           /* constructor_max_index needs to be an INTEGER_CST.  Attempts
6396              to initialize VLAs will cause a proper error; avoid tree
6397              checking errors as well by setting a safe value.  */
6398           if (constructor_max_index
6399               && TREE_CODE (constructor_max_index) != INTEGER_CST)
6400             constructor_max_index = build_int_cst (NULL_TREE, -1);
6401
6402           constructor_index
6403             = convert (bitsizetype,
6404                        TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
6405         }
6406       else
6407         {
6408           constructor_index = bitsize_zero_node;
6409           constructor_max_index = NULL_TREE;
6410         }
6411
6412       constructor_unfilled_index = constructor_index;
6413     }
6414   else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
6415     {
6416       /* Vectors are like simple fixed-size arrays.  */
6417       constructor_max_index =
6418         build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
6419       constructor_index = bitsize_zero_node;
6420       constructor_unfilled_index = constructor_index;
6421     }
6422   else
6423     {
6424       /* Handle the case of int x = {5}; */
6425       constructor_fields = constructor_type;
6426       constructor_unfilled_fields = constructor_type;
6427     }
6428 }
6429 \f
6430 /* Push down into a subobject, for initialization.
6431    If this is for an explicit set of braces, IMPLICIT is 0.
6432    If it is because the next element belongs at a lower level,
6433    IMPLICIT is 1 (or 2 if the push is because of designator list).  */
6434
6435 void
6436 push_init_level (int implicit, struct obstack * braced_init_obstack)
6437 {
6438   struct constructor_stack *p;
6439   tree value = NULL_TREE;
6440
6441   /* If we've exhausted any levels that didn't have braces,
6442      pop them now.  If implicit == 1, this will have been done in
6443      process_init_element; do not repeat it here because in the case
6444      of excess initializers for an empty aggregate this leads to an
6445      infinite cycle of popping a level and immediately recreating
6446      it.  */
6447   if (implicit != 1)
6448     {
6449       while (constructor_stack->implicit)
6450         {
6451           if ((TREE_CODE (constructor_type) == RECORD_TYPE
6452                || TREE_CODE (constructor_type) == UNION_TYPE)
6453               && constructor_fields == 0)
6454             process_init_element (pop_init_level (1, braced_init_obstack),
6455                                   true, braced_init_obstack);
6456           else if (TREE_CODE (constructor_type) == ARRAY_TYPE
6457                    && constructor_max_index
6458                    && tree_int_cst_lt (constructor_max_index,
6459                                        constructor_index))
6460             process_init_element (pop_init_level (1, braced_init_obstack),
6461                                   true, braced_init_obstack);
6462           else
6463             break;
6464         }
6465     }
6466
6467   /* Unless this is an explicit brace, we need to preserve previous
6468      content if any.  */
6469   if (implicit)
6470     {
6471       if ((TREE_CODE (constructor_type) == RECORD_TYPE
6472            || TREE_CODE (constructor_type) == UNION_TYPE)
6473           && constructor_fields)
6474         value = find_init_member (constructor_fields, braced_init_obstack);
6475       else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6476         value = find_init_member (constructor_index, braced_init_obstack);
6477     }
6478
6479   p = XNEW (struct constructor_stack);
6480   p->type = constructor_type;
6481   p->fields = constructor_fields;
6482   p->index = constructor_index;
6483   p->max_index = constructor_max_index;
6484   p->unfilled_index = constructor_unfilled_index;
6485   p->unfilled_fields = constructor_unfilled_fields;
6486   p->bit_index = constructor_bit_index;
6487   p->elements = constructor_elements;
6488   p->constant = constructor_constant;
6489   p->simple = constructor_simple;
6490   p->nonconst = constructor_nonconst;
6491   p->erroneous = constructor_erroneous;
6492   p->pending_elts = constructor_pending_elts;
6493   p->depth = constructor_depth;
6494   p->replacement_value.value = 0;
6495   p->replacement_value.original_code = ERROR_MARK;
6496   p->replacement_value.original_type = NULL;
6497   p->implicit = implicit;
6498   p->outer = 0;
6499   p->incremental = constructor_incremental;
6500   p->designated = constructor_designated;
6501   p->next = constructor_stack;
6502   p->range_stack = 0;
6503   constructor_stack = p;
6504
6505   constructor_constant = 1;
6506   constructor_simple = 1;
6507   constructor_nonconst = 0;
6508   constructor_depth = SPELLING_DEPTH ();
6509   constructor_elements = 0;
6510   constructor_incremental = 1;
6511   constructor_designated = 0;
6512   constructor_pending_elts = 0;
6513   if (!implicit)
6514     {
6515       p->range_stack = constructor_range_stack;
6516       constructor_range_stack = 0;
6517       designator_depth = 0;
6518       designator_erroneous = 0;
6519     }
6520
6521   /* Don't die if an entire brace-pair level is superfluous
6522      in the containing level.  */
6523   if (constructor_type == 0)
6524     ;
6525   else if (TREE_CODE (constructor_type) == RECORD_TYPE
6526            || TREE_CODE (constructor_type) == UNION_TYPE)
6527     {
6528       /* Don't die if there are extra init elts at the end.  */
6529       if (constructor_fields == 0)
6530         constructor_type = 0;
6531       else
6532         {
6533           constructor_type = TREE_TYPE (constructor_fields);
6534           push_member_name (constructor_fields);
6535           constructor_depth++;
6536         }
6537     }
6538   else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6539     {
6540       constructor_type = TREE_TYPE (constructor_type);
6541       push_array_bounds (tree_low_cst (constructor_index, 1));
6542       constructor_depth++;
6543     }
6544
6545   if (constructor_type == 0)
6546     {
6547       error_init ("extra brace group at end of initializer");
6548       constructor_fields = 0;
6549       constructor_unfilled_fields = 0;
6550       return;
6551     }
6552
6553   if (value && TREE_CODE (value) == CONSTRUCTOR)
6554     {
6555       constructor_constant = TREE_CONSTANT (value);
6556       constructor_simple = TREE_STATIC (value);
6557       constructor_nonconst = CONSTRUCTOR_NON_CONST (value);
6558       constructor_elements = CONSTRUCTOR_ELTS (value);
6559       if (!VEC_empty (constructor_elt, constructor_elements)
6560           && (TREE_CODE (constructor_type) == RECORD_TYPE
6561               || TREE_CODE (constructor_type) == ARRAY_TYPE))
6562         set_nonincremental_init (braced_init_obstack);
6563     }
6564
6565   if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned)
6566     {
6567       missing_braces_mentioned = 1;
6568       warning_init (OPT_Wmissing_braces, "missing braces around initializer");
6569     }
6570
6571   if (TREE_CODE (constructor_type) == RECORD_TYPE
6572            || TREE_CODE (constructor_type) == UNION_TYPE)
6573     {
6574       constructor_fields = TYPE_FIELDS (constructor_type);
6575       /* Skip any nameless bit fields at the beginning.  */
6576       while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
6577              && DECL_NAME (constructor_fields) == 0)
6578         constructor_fields = TREE_CHAIN (constructor_fields);
6579
6580       constructor_unfilled_fields = constructor_fields;
6581       constructor_bit_index = bitsize_zero_node;
6582     }
6583   else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
6584     {
6585       /* Vectors are like simple fixed-size arrays.  */
6586       constructor_max_index =
6587         build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
6588       constructor_index = convert (bitsizetype, integer_zero_node);
6589       constructor_unfilled_index = constructor_index;
6590     }
6591   else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6592     {
6593       if (TYPE_DOMAIN (constructor_type))
6594         {
6595           constructor_max_index
6596             = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
6597
6598           /* Detect non-empty initializations of zero-length arrays.  */
6599           if (constructor_max_index == NULL_TREE
6600               && TYPE_SIZE (constructor_type))
6601             constructor_max_index = build_int_cst (NULL_TREE, -1);
6602
6603           /* constructor_max_index needs to be an INTEGER_CST.  Attempts
6604              to initialize VLAs will cause a proper error; avoid tree
6605              checking errors as well by setting a safe value.  */
6606           if (constructor_max_index
6607               && TREE_CODE (constructor_max_index) != INTEGER_CST)
6608             constructor_max_index = build_int_cst (NULL_TREE, -1);
6609
6610           constructor_index
6611             = convert (bitsizetype,
6612                        TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
6613         }
6614       else
6615         constructor_index = bitsize_zero_node;
6616
6617       constructor_unfilled_index = constructor_index;
6618       if (value && TREE_CODE (value) == STRING_CST)
6619         {
6620           /* We need to split the char/wchar array into individual
6621              characters, so that we don't have to special case it
6622              everywhere.  */
6623           set_nonincremental_init_from_string (value, braced_init_obstack);
6624         }
6625     }
6626   else
6627     {
6628       if (constructor_type != error_mark_node)
6629         warning_init (0, "braces around scalar initializer");
6630       constructor_fields = constructor_type;
6631       constructor_unfilled_fields = constructor_type;
6632     }
6633 }
6634
6635 /* At the end of an implicit or explicit brace level,
6636    finish up that level of constructor.  If a single expression
6637    with redundant braces initialized that level, return the
6638    c_expr structure for that expression.  Otherwise, the original_code
6639    element is set to ERROR_MARK.
6640    If we were outputting the elements as they are read, return 0 as the value
6641    from inner levels (process_init_element ignores that),
6642    but return error_mark_node as the value from the outermost level
6643    (that's what we want to put in DECL_INITIAL).
6644    Otherwise, return a CONSTRUCTOR expression as the value.  */
6645
6646 struct c_expr
6647 pop_init_level (int implicit, struct obstack * braced_init_obstack)
6648 {
6649   struct constructor_stack *p;
6650   struct c_expr ret;
6651   ret.value = 0;
6652   ret.original_code = ERROR_MARK;
6653   ret.original_type = NULL;
6654
6655   if (implicit == 0)
6656     {
6657       /* When we come to an explicit close brace,
6658          pop any inner levels that didn't have explicit braces.  */
6659       while (constructor_stack->implicit)
6660         {
6661           process_init_element (pop_init_level (1, braced_init_obstack),
6662                                 true, braced_init_obstack);
6663         }
6664       gcc_assert (!constructor_range_stack);
6665     }
6666
6667   /* Now output all pending elements.  */
6668   constructor_incremental = 1;
6669   output_pending_init_elements (1, braced_init_obstack);
6670
6671   p = constructor_stack;
6672
6673   /* Error for initializing a flexible array member, or a zero-length
6674      array member in an inappropriate context.  */
6675   if (constructor_type && constructor_fields
6676       && TREE_CODE (constructor_type) == ARRAY_TYPE
6677       && TYPE_DOMAIN (constructor_type)
6678       && !TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)))
6679     {
6680       /* Silently discard empty initializations.  The parser will
6681          already have pedwarned for empty brackets.  */
6682       if (integer_zerop (constructor_unfilled_index))
6683         constructor_type = NULL_TREE;
6684       else
6685         {
6686           gcc_assert (!TYPE_SIZE (constructor_type));
6687
6688           if (constructor_depth > 2)
6689             error_init ("initialization of flexible array member in a nested context");
6690           else
6691             pedwarn_init (input_location, OPT_pedantic,
6692                           "initialization of a flexible array member");
6693
6694           /* We have already issued an error message for the existence
6695              of a flexible array member not at the end of the structure.
6696              Discard the initializer so that we do not die later.  */
6697           if (TREE_CHAIN (constructor_fields) != NULL_TREE)
6698             constructor_type = NULL_TREE;
6699         }
6700     }
6701
6702   /* Warn when some struct elements are implicitly initialized to zero.  */
6703   if (warn_missing_field_initializers
6704       && constructor_type
6705       && TREE_CODE (constructor_type) == RECORD_TYPE
6706       && constructor_unfilled_fields)
6707     {
6708         /* Do not warn for flexible array members or zero-length arrays.  */
6709         while (constructor_unfilled_fields
6710                && (!DECL_SIZE (constructor_unfilled_fields)
6711                    || integer_zerop (DECL_SIZE (constructor_unfilled_fields))))
6712           constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
6713
6714         /* Do not warn if this level of the initializer uses member
6715            designators; it is likely to be deliberate.  */
6716         if (constructor_unfilled_fields && !constructor_designated)
6717           {
6718             push_member_name (constructor_unfilled_fields);
6719             warning_init (OPT_Wmissing_field_initializers,
6720                           "missing initializer");
6721             RESTORE_SPELLING_DEPTH (constructor_depth);
6722           }
6723     }
6724
6725   /* Pad out the end of the structure.  */
6726   if (p->replacement_value.value)
6727     /* If this closes a superfluous brace pair,
6728        just pass out the element between them.  */
6729     ret = p->replacement_value;
6730   else if (constructor_type == 0)
6731     ;
6732   else if (TREE_CODE (constructor_type) != RECORD_TYPE
6733            && TREE_CODE (constructor_type) != UNION_TYPE
6734            && TREE_CODE (constructor_type) != ARRAY_TYPE
6735            && TREE_CODE (constructor_type) != VECTOR_TYPE)
6736     {
6737       /* A nonincremental scalar initializer--just return
6738          the element, after verifying there is just one.  */
6739       if (VEC_empty (constructor_elt,constructor_elements))
6740         {
6741           if (!constructor_erroneous)
6742             error_init ("empty scalar initializer");
6743           ret.value = error_mark_node;
6744         }
6745       else if (VEC_length (constructor_elt,constructor_elements) != 1)
6746         {
6747           error_init ("extra elements in scalar initializer");
6748           ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
6749         }
6750       else
6751         ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
6752     }
6753   else
6754     {
6755       if (constructor_erroneous)
6756         ret.value = error_mark_node;
6757       else
6758         {
6759           ret.value = build_constructor (constructor_type,
6760                                          constructor_elements);
6761           if (constructor_constant)
6762             TREE_CONSTANT (ret.value) = 1;
6763           if (constructor_constant && constructor_simple)
6764             TREE_STATIC (ret.value) = 1;
6765           if (constructor_nonconst)
6766             CONSTRUCTOR_NON_CONST (ret.value) = 1;
6767         }
6768     }
6769
6770   if (ret.value && TREE_CODE (ret.value) != CONSTRUCTOR)
6771     {
6772       if (constructor_nonconst)
6773         ret.original_code = C_MAYBE_CONST_EXPR;
6774       else if (ret.original_code == C_MAYBE_CONST_EXPR)
6775         ret.original_code = ERROR_MARK;
6776     }
6777
6778   constructor_type = p->type;
6779   constructor_fields = p->fields;
6780   constructor_index = p->index;
6781   constructor_max_index = p->max_index;
6782   constructor_unfilled_index = p->unfilled_index;
6783   constructor_unfilled_fields = p->unfilled_fields;
6784   constructor_bit_index = p->bit_index;
6785   constructor_elements = p->elements;
6786   constructor_constant = p->constant;
6787   constructor_simple = p->simple;
6788   constructor_nonconst = p->nonconst;
6789   constructor_erroneous = p->erroneous;
6790   constructor_incremental = p->incremental;
6791   constructor_designated = p->designated;
6792   constructor_pending_elts = p->pending_elts;
6793   constructor_depth = p->depth;
6794   if (!p->implicit)
6795     constructor_range_stack = p->range_stack;
6796   RESTORE_SPELLING_DEPTH (constructor_depth);
6797
6798   constructor_stack = p->next;
6799   free (p);
6800
6801   if (ret.value == 0 && constructor_stack == 0)
6802     ret.value = error_mark_node;
6803   return ret;
6804 }
6805
6806 /* Common handling for both array range and field name designators.
6807    ARRAY argument is nonzero for array ranges.  Returns zero for success.  */
6808
6809 static int
6810 set_designator (int array, struct obstack * braced_init_obstack)
6811 {
6812   tree subtype;
6813   enum tree_code subcode;
6814
6815   /* Don't die if an entire brace-pair level is superfluous
6816      in the containing level.  */
6817   if (constructor_type == 0)
6818     return 1;
6819
6820   /* If there were errors in this designator list already, bail out
6821      silently.  */
6822   if (designator_erroneous)
6823     return 1;
6824
6825   if (!designator_depth)
6826     {
6827       gcc_assert (!constructor_range_stack);
6828
6829       /* Designator list starts at the level of closest explicit
6830          braces.  */
6831       while (constructor_stack->implicit)
6832         {
6833           process_init_element (pop_init_level (1, braced_init_obstack),
6834                                 true, braced_init_obstack);
6835         }
6836       constructor_designated = 1;
6837       return 0;
6838     }
6839
6840   switch (TREE_CODE (constructor_type))
6841     {
6842     case  RECORD_TYPE:
6843     case  UNION_TYPE:
6844       subtype = TREE_TYPE (constructor_fields);
6845       if (subtype != error_mark_node)
6846         subtype = TYPE_MAIN_VARIANT (subtype);
6847       break;
6848     case ARRAY_TYPE:
6849       subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6850       break;
6851     default:
6852       gcc_unreachable ();
6853     }
6854
6855   subcode = TREE_CODE (subtype);
6856   if (array && subcode != ARRAY_TYPE)
6857     {
6858       error_init ("array index in non-array initializer");
6859       return 1;
6860     }
6861   else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE)
6862     {
6863       error_init ("field name not in record or union initializer");
6864       return 1;
6865     }
6866
6867   constructor_designated = 1;
6868   push_init_level (2, braced_init_obstack);
6869   return 0;
6870 }
6871
6872 /* If there are range designators in designator list, push a new designator
6873    to constructor_range_stack.  RANGE_END is end of such stack range or
6874    NULL_TREE if there is no range designator at this level.  */
6875
6876 static void
6877 push_range_stack (tree range_end, struct obstack * braced_init_obstack)
6878 {
6879   struct constructor_range_stack *p;
6880
6881   p = (struct constructor_range_stack *)
6882     obstack_alloc (braced_init_obstack,
6883                    sizeof (struct constructor_range_stack));
6884   p->prev = constructor_range_stack;
6885   p->next = 0;
6886   p->fields = constructor_fields;
6887   p->range_start = constructor_index;
6888   p->index = constructor_index;
6889   p->stack = constructor_stack;
6890   p->range_end = range_end;
6891   if (constructor_range_stack)
6892     constructor_range_stack->next = p;
6893   constructor_range_stack = p;
6894 }
6895
6896 /* Within an array initializer, specify the next index to be initialized.
6897    FIRST is that index.  If LAST is nonzero, then initialize a range
6898    of indices, running from FIRST through LAST.  */
6899
6900 void
6901 set_init_index (tree first, tree last,
6902                 struct obstack * braced_init_obstack)
6903 {
6904   if (set_designator (1, braced_init_obstack))
6905     return;
6906
6907   designator_erroneous = 1;
6908
6909   if (!INTEGRAL_TYPE_P (TREE_TYPE (first))
6910       || (last && !INTEGRAL_TYPE_P (TREE_TYPE (last))))
6911     {
6912       error_init ("array index in initializer not of integer type");
6913       return;
6914     }
6915
6916   if (TREE_CODE (first) != INTEGER_CST)
6917     {
6918       first = c_fully_fold (first, false, NULL);
6919       if (TREE_CODE (first) == INTEGER_CST)
6920         pedwarn_init (input_location, OPT_pedantic,
6921                       "array index in initializer is not "
6922                       "an integer constant expression");
6923     }
6924
6925   if (last && TREE_CODE (last) != INTEGER_CST)
6926     {
6927       last = c_fully_fold (last, false, NULL);
6928       if (TREE_CODE (last) == INTEGER_CST)
6929         pedwarn_init (input_location, OPT_pedantic,
6930                       "array index in initializer is not "
6931                       "an integer constant expression");
6932     }
6933
6934   if (TREE_CODE (first) != INTEGER_CST)
6935     error_init ("nonconstant array index in initializer");
6936   else if (last != 0 && TREE_CODE (last) != INTEGER_CST)
6937     error_init ("nonconstant array index in initializer");
6938   else if (TREE_CODE (constructor_type) != ARRAY_TYPE)
6939     error_init ("array index in non-array initializer");
6940   else if (tree_int_cst_sgn (first) == -1)
6941     error_init ("array index in initializer exceeds array bounds");
6942   else if (constructor_max_index
6943            && tree_int_cst_lt (constructor_max_index, first))
6944     error_init ("array index in initializer exceeds array bounds");
6945   else
6946     {
6947       constant_expression_warning (first);
6948       if (last)
6949         constant_expression_warning (last);
6950       constructor_index = convert (bitsizetype, first);
6951
6952       if (last)
6953         {
6954           if (tree_int_cst_equal (first, last))
6955             last = 0;
6956           else if (tree_int_cst_lt (last, first))
6957             {
6958               error_init ("empty index range in initializer");
6959               last = 0;
6960             }
6961           else
6962             {
6963               last = convert (bitsizetype, last);
6964               if (constructor_max_index != 0
6965                   && tree_int_cst_lt (constructor_max_index, last))
6966                 {
6967                   error_init ("array index range in initializer exceeds array bounds");
6968                   last = 0;
6969                 }
6970             }
6971         }
6972
6973       designator_depth++;
6974       designator_erroneous = 0;
6975       if (constructor_range_stack || last)
6976         push_range_stack (last, braced_init_obstack);
6977     }
6978 }
6979
6980 /* Within a struct initializer, specify the next field to be initialized.  */
6981
6982 void
6983 set_init_label (tree fieldname, struct obstack * braced_init_obstack)
6984 {
6985   tree field;
6986
6987   if (set_designator (0, braced_init_obstack))
6988     return;
6989
6990   designator_erroneous = 1;
6991
6992   if (TREE_CODE (constructor_type) != RECORD_TYPE
6993       && TREE_CODE (constructor_type) != UNION_TYPE)
6994     {
6995       error_init ("field name not in record or union initializer");
6996       return;
6997     }
6998
6999   field = lookup_field (constructor_type, fieldname);
7000
7001   if (field == 0)
7002     error ("unknown field %qE specified in initializer", fieldname);
7003   else
7004     do
7005       {
7006         constructor_fields = TREE_VALUE (field);
7007         designator_depth++;
7008         designator_erroneous = 0;
7009         if (constructor_range_stack)
7010           push_range_stack (NULL_TREE, braced_init_obstack);
7011         field = TREE_CHAIN (field);
7012         if (field)
7013           {
7014             if (set_designator (0, braced_init_obstack))
7015               return;
7016           }
7017       }
7018     while (field != NULL_TREE);
7019 }
7020 \f
7021 /* Add a new initializer to the tree of pending initializers.  PURPOSE
7022    identifies the initializer, either array index or field in a structure.
7023    VALUE is the value of that index or field.  If ORIGTYPE is not
7024    NULL_TREE, it is the original type of VALUE.
7025
7026    IMPLICIT is true if value comes from pop_init_level (1),
7027    the new initializer has been merged with the existing one
7028    and thus no warnings should be emitted about overriding an
7029    existing initializer.  */
7030
7031 static void
7032 add_pending_init (tree purpose, tree value, tree origtype, bool implicit,
7033                   struct obstack * braced_init_obstack)
7034 {
7035   struct init_node *p, **q, *r;
7036
7037   q = &constructor_pending_elts;
7038   p = 0;
7039
7040   if (TREE_CODE (constructor_type) == ARRAY_TYPE)
7041     {
7042       while (*q != 0)
7043         {
7044           p = *q;
7045           if (tree_int_cst_lt (purpose, p->purpose))
7046             q = &p->left;
7047           else if (tree_int_cst_lt (p->purpose, purpose))
7048             q = &p->right;
7049           else
7050             {
7051               if (!implicit)
7052                 {
7053                   if (TREE_SIDE_EFFECTS (p->value))
7054                     warning_init (0, "initialized field with side-effects overwritten");
7055                   else if (warn_override_init)
7056                     warning_init (OPT_Woverride_init, "initialized field overwritten");
7057                 }
7058               p->value = value;
7059               p->origtype = origtype;
7060               return;
7061             }
7062         }
7063     }
7064   else
7065     {
7066       tree bitpos;
7067
7068       bitpos = bit_position (purpose);
7069       while (*q != NULL)
7070         {
7071           p = *q;
7072           if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
7073             q = &p->left;
7074           else if (p->purpose != purpose)
7075             q = &p->right;
7076           else
7077             {
7078               if (!implicit)
7079                 {
7080                   if (TREE_SIDE_EFFECTS (p->value))
7081                     warning_init (0, "initialized field with side-effects overwritten");
7082                   else if (warn_override_init)
7083                     warning_init (OPT_Woverride_init, "initialized field overwritten");
7084                 }
7085               p->value = value;
7086               p->origtype = origtype;
7087               return;
7088             }
7089         }
7090     }
7091
7092   r = (struct init_node *) obstack_alloc (braced_init_obstack,
7093                                           sizeof (struct init_node));
7094   r->purpose = purpose;
7095   r->value = value;
7096   r->origtype = origtype;
7097
7098   *q = r;
7099   r->parent = p;
7100   r->left = 0;
7101   r->right = 0;
7102   r->balance = 0;
7103
7104   while (p)
7105     {
7106       struct init_node *s;
7107
7108       if (r == p->left)
7109         {
7110           if (p->balance == 0)
7111             p->balance = -1;
7112           else if (p->balance < 0)
7113             {
7114               if (r->balance < 0)
7115                 {
7116                   /* L rotation.  */
7117                   p->left = r->right;
7118                   if (p->left)
7119                     p->left->parent = p;
7120                   r->right = p;
7121
7122                   p->balance = 0;
7123                   r->balance = 0;
7124
7125                   s = p->parent;
7126                   p->parent = r;
7127                   r->parent = s;
7128                   if (s)
7129                     {
7130                       if (s->left == p)
7131                         s->left = r;
7132                       else
7133                         s->right = r;
7134                     }
7135                   else
7136                     constructor_pending_elts = r;
7137                 }
7138               else
7139                 {
7140                   /* LR rotation.  */
7141                   struct init_node *t = r->right;
7142
7143                   r->right = t->left;
7144                   if (r->right)
7145                     r->right->parent = r;
7146                   t->left = r;
7147
7148                   p->left = t->right;
7149                   if (p->left)
7150                     p->left->parent = p;
7151                   t->right = p;
7152
7153                   p->balance = t->balance < 0;
7154                   r->balance = -(t->balance > 0);
7155                   t->balance = 0;
7156
7157                   s = p->parent;
7158                   p->parent = t;
7159                   r->parent = t;
7160                   t->parent = s;
7161                   if (s)
7162                     {
7163                       if (s->left == p)
7164                         s->left = t;
7165                       else
7166                         s->right = t;
7167                     }
7168                   else
7169                     constructor_pending_elts = t;
7170                 }
7171               break;
7172             }
7173           else
7174             {
7175               /* p->balance == +1; growth of left side balances the node.  */
7176               p->balance = 0;
7177               break;
7178             }
7179         }
7180       else /* r == p->right */
7181         {
7182           if (p->balance == 0)
7183             /* Growth propagation from right side.  */
7184             p->balance++;
7185           else if (p->balance > 0)
7186             {
7187               if (r->balance > 0)
7188                 {
7189                   /* R rotation.  */
7190                   p->right = r->left;
7191                   if (p->right)
7192                     p->right->parent = p;
7193                   r->left = p;
7194
7195                   p->balance = 0;
7196                   r->balance = 0;
7197
7198                   s = p->parent;
7199                   p->parent = r;
7200                   r->parent = s;
7201                   if (s)
7202                     {
7203                       if (s->left == p)
7204                         s->left = r;
7205                       else
7206                         s->right = r;
7207                     }
7208                   else
7209                     constructor_pending_elts = r;
7210                 }
7211               else /* r->balance == -1 */
7212                 {
7213                   /* RL rotation */
7214                   struct init_node *t = r->left;
7215
7216                   r->left = t->right;
7217                   if (r->left)
7218                     r->left->parent = r;
7219                   t->right = r;
7220
7221                   p->right = t->left;
7222                   if (p->right)
7223                     p->right->parent = p;
7224                   t->left = p;
7225
7226                   r->balance = (t->balance < 0);
7227                   p->balance = -(t->balance > 0);
7228                   t->balance = 0;
7229
7230                   s = p->parent;
7231                   p->parent = t;
7232                   r->parent = t;
7233                   t->parent = s;
7234                   if (s)
7235                     {
7236                       if (s->left == p)
7237                         s->left = t;
7238                       else
7239                         s->right = t;
7240                     }
7241                   else
7242                     constructor_pending_elts = t;
7243                 }
7244               break;
7245             }
7246           else
7247             {
7248               /* p->balance == -1; growth of right side balances the node.  */
7249               p->balance = 0;
7250               break;
7251             }
7252         }
7253
7254       r = p;
7255       p = p->parent;
7256     }
7257 }
7258
7259 /* Build AVL tree from a sorted chain.  */
7260
7261 static void
7262 set_nonincremental_init (struct obstack * braced_init_obstack)
7263 {
7264   unsigned HOST_WIDE_INT ix;
7265   tree index, value;
7266
7267   if (TREE_CODE (constructor_type) != RECORD_TYPE
7268       && TREE_CODE (constructor_type) != ARRAY_TYPE)
7269     return;
7270
7271   FOR_EACH_CONSTRUCTOR_ELT (constructor_elements, ix, index, value)
7272     {
7273       add_pending_init (index, value, NULL_TREE, false,
7274                         braced_init_obstack);
7275     }
7276   constructor_elements = 0;
7277   if (TREE_CODE (constructor_type) == RECORD_TYPE)
7278     {
7279       constructor_unfilled_fields = TYPE_FIELDS (constructor_type);
7280       /* Skip any nameless bit fields at the beginning.  */
7281       while (constructor_unfilled_fields != 0
7282              && DECL_C_BIT_FIELD (constructor_unfilled_fields)
7283              && DECL_NAME (constructor_unfilled_fields) == 0)
7284         constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
7285
7286     }
7287   else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
7288     {
7289       if (TYPE_DOMAIN (constructor_type))
7290         constructor_unfilled_index
7291             = convert (bitsizetype,
7292                        TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
7293       else
7294         constructor_unfilled_index = bitsize_zero_node;
7295     }
7296   constructor_incremental = 0;
7297 }
7298
7299 /* Build AVL tree from a string constant.  */
7300
7301 static void
7302 set_nonincremental_init_from_string (tree str,
7303                                      struct obstack * braced_init_obstack)
7304 {
7305   tree value, purpose, type;
7306   HOST_WIDE_INT val[2];
7307   const char *p, *end;
7308   int byte, wchar_bytes, charwidth, bitpos;
7309
7310   gcc_assert (TREE_CODE (constructor_type) == ARRAY_TYPE);
7311
7312   wchar_bytes = TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) / BITS_PER_UNIT;
7313   charwidth = TYPE_PRECISION (char_type_node);
7314   type = TREE_TYPE (constructor_type);
7315   p = TREE_STRING_POINTER (str);
7316   end = p + TREE_STRING_LENGTH (str);
7317
7318   for (purpose = bitsize_zero_node;
7319        p < end && !tree_int_cst_lt (constructor_max_index, purpose);
7320        purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node))
7321     {
7322       if (wchar_bytes == 1)
7323         {
7324           val[1] = (unsigned char) *p++;
7325           val[0] = 0;
7326         }
7327       else
7328         {
7329           val[0] = 0;
7330           val[1] = 0;
7331           for (byte = 0; byte < wchar_bytes; byte++)
7332             {
7333               if (BYTES_BIG_ENDIAN)
7334                 bitpos = (wchar_bytes - byte - 1) * charwidth;
7335               else
7336                 bitpos = byte * charwidth;
7337               val[bitpos < HOST_BITS_PER_WIDE_INT]
7338                 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++))
7339                    << (bitpos % HOST_BITS_PER_WIDE_INT);
7340             }
7341         }
7342
7343       if (!TYPE_UNSIGNED (type))
7344         {
7345           bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR;
7346           if (bitpos < HOST_BITS_PER_WIDE_INT)
7347             {
7348               if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1)))
7349                 {
7350                   val[1] |= ((HOST_WIDE_INT) -1) << bitpos;
7351                   val[0] = -1;
7352                 }
7353             }
7354           else if (bitpos == HOST_BITS_PER_WIDE_INT)
7355             {
7356               if (val[1] < 0)
7357                 val[0] = -1;
7358             }
7359           else if (val[0] & (((HOST_WIDE_INT) 1)
7360                              << (bitpos - 1 - HOST_BITS_PER_WIDE_INT)))
7361             val[0] |= ((HOST_WIDE_INT) -1)
7362                       << (bitpos - HOST_BITS_PER_WIDE_INT);
7363         }
7364
7365       value = build_int_cst_wide (type, val[1], val[0]);
7366       add_pending_init (purpose, value, NULL_TREE, false,
7367                         braced_init_obstack);
7368     }
7369
7370   constructor_incremental = 0;
7371 }
7372
7373 /* Return value of FIELD in pending initializer or zero if the field was
7374    not initialized yet.  */
7375
7376 static tree
7377 find_init_member (tree field, struct obstack * braced_init_obstack)
7378 {
7379   struct init_node *p;
7380
7381   if (TREE_CODE (constructor_type) == ARRAY_TYPE)
7382     {
7383       if (constructor_incremental
7384           && tree_int_cst_lt (field, constructor_unfilled_index))
7385         set_nonincremental_init (braced_init_obstack);
7386
7387       p = constructor_pending_elts;
7388       while (p)
7389         {
7390           if (tree_int_cst_lt (field, p->purpose))
7391             p = p->left;
7392           else if (tree_int_cst_lt (p->purpose, field))
7393             p = p->right;
7394           else
7395             return p->value;
7396         }
7397     }
7398   else if (TREE_CODE (constructor_type) == RECORD_TYPE)
7399     {
7400       tree bitpos = bit_position (field);
7401
7402       if (constructor_incremental
7403           && (!constructor_unfilled_fields
7404               || tree_int_cst_lt (bitpos,
7405                                   bit_position (constructor_unfilled_fields))))
7406         set_nonincremental_init (braced_init_obstack);
7407
7408       p = constructor_pending_elts;
7409       while (p)
7410         {
7411           if (field == p->purpose)
7412             return p->value;
7413           else if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
7414             p = p->left;
7415           else
7416             p = p->right;
7417         }
7418     }
7419   else if (TREE_CODE (constructor_type) == UNION_TYPE)
7420     {
7421       if (!VEC_empty (constructor_elt, constructor_elements)
7422           && (VEC_last (constructor_elt, constructor_elements)->index
7423               == field))
7424         return VEC_last (constructor_elt, constructor_elements)->value;
7425     }
7426   return 0;
7427 }
7428
7429 /* "Output" the next constructor element.
7430    At top level, really output it to assembler code now.
7431    Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
7432    If ORIGTYPE is not NULL_TREE, it is the original type of VALUE.
7433    TYPE is the data type that the containing data type wants here.
7434    FIELD is the field (a FIELD_DECL) or the index that this element fills.
7435    If VALUE is a string constant, STRICT_STRING is true if it is
7436    unparenthesized or we should not warn here for it being parenthesized.
7437    For other types of VALUE, STRICT_STRING is not used.
7438
7439    PENDING if non-nil means output pending elements that belong
7440    right after this element.  (PENDING is normally 1;
7441    it is 0 while outputting pending elements, to avoid recursion.)
7442
7443    IMPLICIT is true if value comes from pop_init_level (1),
7444    the new initializer has been merged with the existing one
7445    and thus no warnings should be emitted about overriding an
7446    existing initializer.  */
7447
7448 static void
7449 output_init_element (tree value, tree origtype, bool strict_string, tree type,
7450                      tree field, int pending, bool implicit,
7451                      struct obstack * braced_init_obstack)
7452 {
7453   tree semantic_type = NULL_TREE;
7454   constructor_elt *celt;
7455   bool maybe_const = true;
7456   bool npc;
7457
7458   if (type == error_mark_node || value == error_mark_node)
7459     {
7460       constructor_erroneous = 1;
7461       return;
7462     }
7463   if (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
7464       && (TREE_CODE (value) == STRING_CST
7465           || TREE_CODE (value) == COMPOUND_LITERAL_EXPR)
7466       && !(TREE_CODE (value) == STRING_CST
7467            && TREE_CODE (type) == ARRAY_TYPE
7468            && INTEGRAL_TYPE_P (TREE_TYPE (type)))
7469       && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)),
7470                      TYPE_MAIN_VARIANT (type)))
7471     value = array_to_pointer_conversion (input_location, value);
7472
7473   if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR
7474       && require_constant_value && !flag_isoc99 && pending)
7475     {
7476       /* As an extension, allow initializing objects with static storage
7477          duration with compound literals (which are then treated just as
7478          the brace enclosed list they contain).  */
7479       tree decl = COMPOUND_LITERAL_EXPR_DECL (value);
7480       value = DECL_INITIAL (decl);
7481     }
7482
7483   npc = null_pointer_constant_p (value);
7484   if (TREE_CODE (value) == EXCESS_PRECISION_EXPR)
7485     {
7486       semantic_type = TREE_TYPE (value);
7487       value = TREE_OPERAND (value, 0);
7488     }
7489   value = c_fully_fold (value, require_constant_value, &maybe_const);
7490
7491   if (value == error_mark_node)
7492     constructor_erroneous = 1;
7493   else if (!TREE_CONSTANT (value))
7494     constructor_constant = 0;
7495   else if (!initializer_constant_valid_p (value, TREE_TYPE (value))
7496            || ((TREE_CODE (constructor_type) == RECORD_TYPE
7497                 || TREE_CODE (constructor_type) == UNION_TYPE)
7498                && DECL_C_BIT_FIELD (field)
7499                && TREE_CODE (value) != INTEGER_CST))
7500     constructor_simple = 0;
7501   if (!maybe_const)
7502     constructor_nonconst = 1;
7503
7504   if (!initializer_constant_valid_p (value, TREE_TYPE (value)))
7505     {
7506       if (require_constant_value)
7507         {
7508           error_init ("initializer element is not constant");
7509           value = error_mark_node;
7510         }
7511       else if (require_constant_elements)
7512         pedwarn (input_location, 0,
7513                  "initializer element is not computable at load time");
7514     }
7515   else if (!maybe_const
7516            && (require_constant_value || require_constant_elements))
7517     pedwarn_init (input_location, 0,
7518                   "initializer element is not a constant expression");
7519
7520   /* Issue -Wc++-compat warnings about initializing a bitfield with
7521      enum type.  */
7522   if (warn_cxx_compat
7523       && field != NULL_TREE
7524       && TREE_CODE (field) == FIELD_DECL
7525       && DECL_BIT_FIELD_TYPE (field) != NULL_TREE
7526       && (TYPE_MAIN_VARIANT (DECL_BIT_FIELD_TYPE (field))
7527           != TYPE_MAIN_VARIANT (type))
7528       && TREE_CODE (DECL_BIT_FIELD_TYPE (field)) == ENUMERAL_TYPE)
7529     {
7530       tree checktype = origtype != NULL_TREE ? origtype : TREE_TYPE (value);
7531       if (checktype != error_mark_node
7532           && (TYPE_MAIN_VARIANT (checktype)
7533               != TYPE_MAIN_VARIANT (DECL_BIT_FIELD_TYPE (field))))
7534         warning_init (OPT_Wc___compat,
7535                       "enum conversion in initialization is invalid in C++");
7536     }
7537
7538   /* If this field is empty (and not at the end of structure),
7539      don't do anything other than checking the initializer.  */
7540   if (field
7541       && (TREE_TYPE (field) == error_mark_node
7542           || (COMPLETE_TYPE_P (TREE_TYPE (field))
7543               && integer_zerop (TYPE_SIZE (TREE_TYPE (field)))
7544               && (TREE_CODE (constructor_type) == ARRAY_TYPE
7545                   || TREE_CHAIN (field)))))
7546     return;
7547
7548   if (semantic_type)
7549     value = build1 (EXCESS_PRECISION_EXPR, semantic_type, value);
7550   value = digest_init (input_location, type, value, origtype, npc,
7551                        strict_string, require_constant_value);
7552   if (value == error_mark_node)
7553     {
7554       constructor_erroneous = 1;
7555       return;
7556     }
7557   if (require_constant_value || require_constant_elements)
7558     constant_expression_warning (value);
7559
7560   /* If this element doesn't come next in sequence,
7561      put it on constructor_pending_elts.  */
7562   if (TREE_CODE (constructor_type) == ARRAY_TYPE
7563       && (!constructor_incremental
7564           || !tree_int_cst_equal (field, constructor_unfilled_index)))
7565     {
7566       if (constructor_incremental
7567           && tree_int_cst_lt (field, constructor_unfilled_index))
7568         set_nonincremental_init (braced_init_obstack);
7569
7570       add_pending_init (field, value, origtype, implicit,
7571                         braced_init_obstack);
7572       return;
7573     }
7574   else if (TREE_CODE (constructor_type) == RECORD_TYPE
7575            && (!constructor_incremental
7576                || field != constructor_unfilled_fields))
7577     {
7578       /* We do this for records but not for unions.  In a union,
7579          no matter which field is specified, it can be initialized
7580          right away since it starts at the beginning of the union.  */
7581       if (constructor_incremental)
7582         {
7583           if (!constructor_unfilled_fields)
7584             set_nonincremental_init (braced_init_obstack);
7585           else
7586             {
7587               tree bitpos, unfillpos;
7588
7589               bitpos = bit_position (field);
7590               unfillpos = bit_position (constructor_unfilled_fields);
7591
7592               if (tree_int_cst_lt (bitpos, unfillpos))
7593                 set_nonincremental_init (braced_init_obstack);
7594             }
7595         }
7596
7597       add_pending_init (field, value, origtype, implicit,
7598                         braced_init_obstack);
7599       return;
7600     }
7601   else if (TREE_CODE (constructor_type) == UNION_TYPE
7602            && !VEC_empty (constructor_elt, constructor_elements))
7603     {
7604       if (!implicit)
7605         {
7606           if (TREE_SIDE_EFFECTS (VEC_last (constructor_elt,
7607                                            constructor_elements)->value))
7608             warning_init (0,
7609                           "initialized field with side-effects overwritten");
7610           else if (warn_override_init)
7611             warning_init (OPT_Woverride_init, "initialized field overwritten");
7612         }
7613
7614       /* We can have just one union field set.  */
7615       constructor_elements = 0;
7616     }
7617
7618   /* Otherwise, output this element either to
7619      constructor_elements or to the assembler file.  */
7620
7621   celt = VEC_safe_push (constructor_elt, gc, constructor_elements, NULL);
7622   celt->index = field;
7623   celt->value = value;
7624
7625   /* Advance the variable that indicates sequential elements output.  */
7626   if (TREE_CODE (constructor_type) == ARRAY_TYPE)
7627     constructor_unfilled_index
7628       = size_binop_loc (input_location, PLUS_EXPR, constructor_unfilled_index,
7629                         bitsize_one_node);
7630   else if (TREE_CODE (constructor_type) == RECORD_TYPE)
7631     {
7632       constructor_unfilled_fields
7633         = TREE_CHAIN (constructor_unfilled_fields);
7634
7635       /* Skip any nameless bit fields.  */
7636       while (constructor_unfilled_fields != 0
7637              && DECL_C_BIT_FIELD (constructor_unfilled_fields)
7638              && DECL_NAME (constructor_unfilled_fields) == 0)
7639         constructor_unfilled_fields =
7640           TREE_CHAIN (constructor_unfilled_fields);
7641     }
7642   else if (TREE_CODE (constructor_type) == UNION_TYPE)
7643     constructor_unfilled_fields = 0;
7644
7645   /* Now output any pending elements which have become next.  */
7646   if (pending)
7647     output_pending_init_elements (0, braced_init_obstack);
7648 }
7649
7650 /* Output any pending elements which have become next.
7651    As we output elements, constructor_unfilled_{fields,index}
7652    advances, which may cause other elements to become next;
7653    if so, they too are output.
7654
7655    If ALL is 0, we return when there are
7656    no more pending elements to output now.
7657
7658    If ALL is 1, we output space as necessary so that
7659    we can output all the pending elements.  */
7660 static void
7661 output_pending_init_elements (int all, struct obstack * braced_init_obstack)
7662 {
7663   struct init_node *elt = constructor_pending_elts;
7664   tree next;
7665
7666  retry:
7667
7668   /* Look through the whole pending tree.
7669      If we find an element that should be output now,
7670      output it.  Otherwise, set NEXT to the element
7671      that comes first among those still pending.  */
7672
7673   next = 0;
7674   while (elt)
7675     {
7676       if (TREE_CODE (constructor_type) == ARRAY_TYPE)
7677         {
7678           if (tree_int_cst_equal (elt->purpose,
7679                                   constructor_unfilled_index))
7680             output_init_element (elt->value, elt->origtype, true,
7681                                  TREE_TYPE (constructor_type),
7682                                  constructor_unfilled_index, 0, false,
7683                                  braced_init_obstack);
7684           else if (tree_int_cst_lt (constructor_unfilled_index,
7685                                     elt->purpose))
7686             {
7687               /* Advance to the next smaller node.  */
7688               if (elt->left)
7689                 elt = elt->left;
7690               else
7691                 {
7692                   /* We have reached the smallest node bigger than the
7693                      current unfilled index.  Fill the space first.  */
7694                   next = elt->purpose;
7695                   break;
7696                 }
7697             }
7698           else
7699             {
7700               /* Advance to the next bigger node.  */
7701               if (elt->right)
7702                 elt = elt->right;
7703               else
7704                 {
7705                   /* We have reached the biggest node in a subtree.  Find
7706                      the parent of it, which is the next bigger node.  */
7707                   while (elt->parent && elt->parent->right == elt)
7708                     elt = elt->parent;
7709                   elt = elt->parent;
7710                   if (elt && tree_int_cst_lt (constructor_unfilled_index,
7711                                               elt->purpose))
7712                     {
7713                       next = elt->purpose;
7714                       break;
7715                     }
7716                 }
7717             }
7718         }
7719       else if (TREE_CODE (constructor_type) == RECORD_TYPE
7720                || TREE_CODE (constructor_type) == UNION_TYPE)
7721         {
7722           tree ctor_unfilled_bitpos, elt_bitpos;
7723
7724           /* If the current record is complete we are done.  */
7725           if (constructor_unfilled_fields == 0)
7726             break;
7727
7728           ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields);
7729           elt_bitpos = bit_position (elt->purpose);
7730           /* We can't compare fields here because there might be empty
7731              fields in between.  */
7732           if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos))
7733             {
7734               constructor_unfilled_fields = elt->purpose;
7735               output_init_element (elt->value, elt->origtype, true,
7736                                    TREE_TYPE (elt->purpose),
7737                                    elt->purpose, 0, false,
7738                                    braced_init_obstack);
7739             }
7740           else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos))
7741             {
7742               /* Advance to the next smaller node.  */
7743               if (elt->left)
7744                 elt = elt->left;
7745               else
7746                 {
7747                   /* We have reached the smallest node bigger than the
7748                      current unfilled field.  Fill the space first.  */
7749                   next = elt->purpose;
7750                   break;
7751                 }
7752             }
7753           else
7754             {
7755               /* Advance to the next bigger node.  */
7756               if (elt->right)
7757                 elt = elt->right;
7758               else
7759                 {
7760                   /* We have reached the biggest node in a subtree.  Find
7761                      the parent of it, which is the next bigger node.  */
7762                   while (elt->parent && elt->parent->right == elt)
7763                     elt = elt->parent;
7764                   elt = elt->parent;
7765                   if (elt
7766                       && (tree_int_cst_lt (ctor_unfilled_bitpos,
7767                                            bit_position (elt->purpose))))
7768                     {
7769                       next = elt->purpose;
7770                       break;
7771                     }
7772                 }
7773             }
7774         }
7775     }
7776
7777   /* Ordinarily return, but not if we want to output all
7778      and there are elements left.  */
7779   if (!(all && next != 0))
7780     return;
7781
7782   /* If it's not incremental, just skip over the gap, so that after
7783      jumping to retry we will output the next successive element.  */
7784   if (TREE_CODE (constructor_type) == RECORD_TYPE
7785       || TREE_CODE (constructor_type) == UNION_TYPE)
7786     constructor_unfilled_fields = next;
7787   else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
7788     constructor_unfilled_index = next;
7789
7790   /* ELT now points to the node in the pending tree with the next
7791      initializer to output.  */
7792   goto retry;
7793 }
7794 \f
7795 /* Add one non-braced element to the current constructor level.
7796    This adjusts the current position within the constructor's type.
7797    This may also start or terminate implicit levels
7798    to handle a partly-braced initializer.
7799
7800    Once this has found the correct level for the new element,
7801    it calls output_init_element.
7802
7803    IMPLICIT is true if value comes from pop_init_level (1),
7804    the new initializer has been merged with the existing one
7805    and thus no warnings should be emitted about overriding an
7806    existing initializer.  */
7807
7808 void
7809 process_init_element (struct c_expr value, bool implicit,
7810                       struct obstack * braced_init_obstack)
7811 {
7812   tree orig_value = value.value;
7813   int string_flag = orig_value != 0 && TREE_CODE (orig_value) == STRING_CST;
7814   bool strict_string = value.original_code == STRING_CST;
7815
7816   designator_depth = 0;
7817   designator_erroneous = 0;
7818
7819   /* Handle superfluous braces around string cst as in
7820      char x[] = {"foo"}; */
7821   if (string_flag
7822       && constructor_type
7823       && TREE_CODE (constructor_type) == ARRAY_TYPE
7824       && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type))
7825       && integer_zerop (constructor_unfilled_index))
7826     {
7827       if (constructor_stack->replacement_value.value)
7828         error_init ("excess elements in char array initializer");
7829       constructor_stack->replacement_value = value;
7830       return;
7831     }
7832
7833   if (constructor_stack->replacement_value.value != 0)
7834     {
7835       error_init ("excess elements in struct initializer");
7836       return;
7837     }
7838
7839   /* Ignore elements of a brace group if it is entirely superfluous
7840      and has already been diagnosed.  */
7841   if (constructor_type == 0)
7842     return;
7843
7844   /* If we've exhausted any levels that didn't have braces,
7845      pop them now.  */
7846   while (constructor_stack->implicit)
7847     {
7848       if ((TREE_CODE (constructor_type) == RECORD_TYPE
7849            || TREE_CODE (constructor_type) == UNION_TYPE)
7850           && constructor_fields == 0)
7851         process_init_element (pop_init_level (1, braced_init_obstack),
7852                               true, braced_init_obstack);
7853       else if ((TREE_CODE (constructor_type) == ARRAY_TYPE
7854                 || TREE_CODE (constructor_type) == VECTOR_TYPE)
7855                && (constructor_max_index == 0
7856                    || tree_int_cst_lt (constructor_max_index,
7857                                        constructor_index)))
7858         process_init_element (pop_init_level (1, braced_init_obstack),
7859                               true, braced_init_obstack);
7860       else
7861         break;
7862     }
7863
7864   /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once.  */
7865   if (constructor_range_stack)
7866     {
7867       /* If value is a compound literal and we'll be just using its
7868          content, don't put it into a SAVE_EXPR.  */
7869       if (TREE_CODE (value.value) != COMPOUND_LITERAL_EXPR
7870           || !require_constant_value
7871           || flag_isoc99)
7872         {
7873           tree semantic_type = NULL_TREE;
7874           if (TREE_CODE (value.value) == EXCESS_PRECISION_EXPR)
7875             {
7876               semantic_type = TREE_TYPE (value.value);
7877               value.value = TREE_OPERAND (value.value, 0);
7878             }
7879           value.value = c_save_expr (value.value);
7880           if (semantic_type)
7881             value.value = build1 (EXCESS_PRECISION_EXPR, semantic_type,
7882                                   value.value);
7883         }
7884     }
7885
7886   while (1)
7887     {
7888       if (TREE_CODE (constructor_type) == RECORD_TYPE)
7889         {
7890           tree fieldtype;
7891           enum tree_code fieldcode;
7892
7893           if (constructor_fields == 0)
7894             {
7895               pedwarn_init (input_location, 0,
7896                             "excess elements in struct initializer");
7897               break;
7898             }
7899
7900           fieldtype = TREE_TYPE (constructor_fields);
7901           if (fieldtype != error_mark_node)
7902             fieldtype = TYPE_MAIN_VARIANT (fieldtype);
7903           fieldcode = TREE_CODE (fieldtype);
7904
7905           /* Error for non-static initialization of a flexible array member.  */
7906           if (fieldcode == ARRAY_TYPE
7907               && !require_constant_value
7908               && TYPE_SIZE (fieldtype) == NULL_TREE
7909               && TREE_CHAIN (constructor_fields) == NULL_TREE)
7910             {
7911               error_init ("non-static initialization of a flexible array member");
7912               break;
7913             }
7914
7915           /* Accept a string constant to initialize a subarray.  */
7916           if (value.value != 0
7917               && fieldcode == ARRAY_TYPE
7918               && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
7919               && string_flag)
7920             value.value = orig_value;
7921           /* Otherwise, if we have come to a subaggregate,
7922              and we don't have an element of its type, push into it.  */
7923           else if (value.value != 0
7924                    && value.value != error_mark_node
7925                    && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
7926                    && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
7927                        || fieldcode == UNION_TYPE || fieldcode == VECTOR_TYPE))
7928             {
7929               push_init_level (1, braced_init_obstack);
7930               continue;
7931             }
7932
7933           if (value.value)
7934             {
7935               push_member_name (constructor_fields);
7936               output_init_element (value.value, value.original_type,
7937                                    strict_string, fieldtype,
7938                                    constructor_fields, 1, implicit,
7939                                    braced_init_obstack);
7940               RESTORE_SPELLING_DEPTH (constructor_depth);
7941             }
7942           else
7943             /* Do the bookkeeping for an element that was
7944                directly output as a constructor.  */
7945             {
7946               /* For a record, keep track of end position of last field.  */
7947               if (DECL_SIZE (constructor_fields))
7948                 constructor_bit_index
7949                   = size_binop_loc (input_location, PLUS_EXPR,
7950                                     bit_position (constructor_fields),
7951                                     DECL_SIZE (constructor_fields));
7952
7953               /* If the current field was the first one not yet written out,
7954                  it isn't now, so update.  */
7955               if (constructor_unfilled_fields == constructor_fields)
7956                 {
7957                   constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
7958                   /* Skip any nameless bit fields.  */
7959                   while (constructor_unfilled_fields != 0
7960                          && DECL_C_BIT_FIELD (constructor_unfilled_fields)
7961                          && DECL_NAME (constructor_unfilled_fields) == 0)
7962                     constructor_unfilled_fields =
7963                       TREE_CHAIN (constructor_unfilled_fields);
7964                 }
7965             }
7966
7967           constructor_fields = TREE_CHAIN (constructor_fields);
7968           /* Skip any nameless bit fields at the beginning.  */
7969           while (constructor_fields != 0
7970                  && DECL_C_BIT_FIELD (constructor_fields)
7971                  && DECL_NAME (constructor_fields) == 0)
7972             constructor_fields = TREE_CHAIN (constructor_fields);
7973         }
7974       else if (TREE_CODE (constructor_type) == UNION_TYPE)
7975         {
7976           tree fieldtype;
7977           enum tree_code fieldcode;
7978
7979           if (constructor_fields == 0)
7980             {
7981               pedwarn_init (input_location, 0,
7982                             "excess elements in union initializer");
7983               break;
7984             }
7985
7986           fieldtype = TREE_TYPE (constructor_fields);
7987           if (fieldtype != error_mark_node)
7988             fieldtype = TYPE_MAIN_VARIANT (fieldtype);
7989           fieldcode = TREE_CODE (fieldtype);
7990
7991           /* Warn that traditional C rejects initialization of unions.
7992              We skip the warning if the value is zero.  This is done
7993              under the assumption that the zero initializer in user
7994              code appears conditioned on e.g. __STDC__ to avoid
7995              "missing initializer" warnings and relies on default
7996              initialization to zero in the traditional C case.
7997              We also skip the warning if the initializer is designated,
7998              again on the assumption that this must be conditional on
7999              __STDC__ anyway (and we've already complained about the
8000              member-designator already).  */
8001           if (!in_system_header && !constructor_designated
8002               && !(value.value && (integer_zerop (value.value)
8003                                    || real_zerop (value.value))))
8004             warning (OPT_Wtraditional, "traditional C rejects initialization "
8005                      "of unions");
8006
8007           /* Accept a string constant to initialize a subarray.  */
8008           if (value.value != 0
8009               && fieldcode == ARRAY_TYPE
8010               && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
8011               && string_flag)
8012             value.value = orig_value;
8013           /* Otherwise, if we have come to a subaggregate,
8014              and we don't have an element of its type, push into it.  */
8015           else if (value.value != 0
8016                    && value.value != error_mark_node
8017                    && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
8018                    && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
8019                        || fieldcode == UNION_TYPE || fieldcode == VECTOR_TYPE))
8020             {
8021               push_init_level (1, braced_init_obstack);
8022               continue;
8023             }
8024
8025           if (value.value)
8026             {
8027               push_member_name (constructor_fields);
8028               output_init_element (value.value, value.original_type,
8029                                    strict_string, fieldtype,
8030                                    constructor_fields, 1, implicit,
8031                                    braced_init_obstack);
8032               RESTORE_SPELLING_DEPTH (constructor_depth);
8033             }
8034           else
8035             /* Do the bookkeeping for an element that was
8036                directly output as a constructor.  */
8037             {
8038               constructor_bit_index = DECL_SIZE (constructor_fields);
8039               constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
8040             }
8041
8042           constructor_fields = 0;
8043         }
8044       else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
8045         {
8046           tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
8047           enum tree_code eltcode = TREE_CODE (elttype);
8048
8049           /* Accept a string constant to initialize a subarray.  */
8050           if (value.value != 0
8051               && eltcode == ARRAY_TYPE
8052               && INTEGRAL_TYPE_P (TREE_TYPE (elttype))
8053               && string_flag)
8054             value.value = orig_value;
8055           /* Otherwise, if we have come to a subaggregate,
8056              and we don't have an element of its type, push into it.  */
8057           else if (value.value != 0
8058                    && value.value != error_mark_node
8059                    && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != elttype
8060                    && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE
8061                        || eltcode == UNION_TYPE || eltcode == VECTOR_TYPE))
8062             {
8063               push_init_level (1, braced_init_obstack);
8064               continue;
8065             }
8066
8067           if (constructor_max_index != 0
8068               && (tree_int_cst_lt (constructor_max_index, constructor_index)
8069                   || integer_all_onesp (constructor_max_index)))
8070             {
8071               pedwarn_init (input_location, 0,
8072                             "excess elements in array initializer");
8073               break;
8074             }
8075
8076           /* Now output the actual element.  */
8077           if (value.value)
8078             {
8079               push_array_bounds (tree_low_cst (constructor_index, 1));
8080               output_init_element (value.value, value.original_type,
8081                                    strict_string, elttype,
8082                                    constructor_index, 1, implicit,
8083                                    braced_init_obstack);
8084               RESTORE_SPELLING_DEPTH (constructor_depth);
8085             }
8086
8087           constructor_index
8088             = size_binop_loc (input_location, PLUS_EXPR,
8089                               constructor_index, bitsize_one_node);
8090
8091           if (!value.value)
8092             /* If we are doing the bookkeeping for an element that was
8093                directly output as a constructor, we must update
8094                constructor_unfilled_index.  */
8095             constructor_unfilled_index = constructor_index;
8096         }
8097       else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
8098         {
8099           tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
8100
8101          /* Do a basic check of initializer size.  Note that vectors
8102             always have a fixed size derived from their type.  */
8103           if (tree_int_cst_lt (constructor_max_index, constructor_index))
8104             {
8105               pedwarn_init (input_location, 0,
8106                             "excess elements in vector initializer");
8107               break;
8108             }
8109
8110           /* Now output the actual element.  */
8111           if (value.value)
8112             {
8113               if (TREE_CODE (value.value) == VECTOR_CST)
8114                 elttype = TYPE_MAIN_VARIANT (constructor_type);
8115               output_init_element (value.value, value.original_type,
8116                                    strict_string, elttype,
8117                                    constructor_index, 1, implicit,
8118                                    braced_init_obstack);
8119             }
8120
8121           constructor_index
8122             = size_binop_loc (input_location,
8123                               PLUS_EXPR, constructor_index, bitsize_one_node);
8124
8125           if (!value.value)
8126             /* If we are doing the bookkeeping for an element that was
8127                directly output as a constructor, we must update
8128                constructor_unfilled_index.  */
8129             constructor_unfilled_index = constructor_index;
8130         }
8131
8132       /* Handle the sole element allowed in a braced initializer
8133          for a scalar variable.  */
8134       else if (constructor_type != error_mark_node
8135                && constructor_fields == 0)
8136         {
8137           pedwarn_init (input_location, 0,
8138                         "excess elements in scalar initializer");
8139           break;
8140         }
8141       else
8142         {
8143           if (value.value)
8144             output_init_element (value.value, value.original_type,
8145                                  strict_string, constructor_type,
8146                                  NULL_TREE, 1, implicit,
8147                                  braced_init_obstack);
8148           constructor_fields = 0;
8149         }
8150
8151       /* Handle range initializers either at this level or anywhere higher
8152          in the designator stack.  */
8153       if (constructor_range_stack)
8154         {
8155           struct constructor_range_stack *p, *range_stack;
8156           int finish = 0;
8157
8158           range_stack = constructor_range_stack;
8159           constructor_range_stack = 0;
8160           while (constructor_stack != range_stack->stack)
8161             {
8162               gcc_assert (constructor_stack->implicit);
8163               process_init_element (pop_init_level (1,
8164                                                     braced_init_obstack),
8165                                     true, braced_init_obstack);
8166             }
8167           for (p = range_stack;
8168                !p->range_end || tree_int_cst_equal (p->index, p->range_end);
8169                p = p->prev)
8170             {
8171               gcc_assert (constructor_stack->implicit);
8172               process_init_element (pop_init_level (1, braced_init_obstack),
8173                                     true, braced_init_obstack);
8174             }
8175
8176           p->index = size_binop_loc (input_location,
8177                                      PLUS_EXPR, p->index, bitsize_one_node);
8178           if (tree_int_cst_equal (p->index, p->range_end) && !p->prev)
8179             finish = 1;
8180
8181           while (1)
8182             {
8183               constructor_index = p->index;
8184               constructor_fields = p->fields;
8185               if (finish && p->range_end && p->index == p->range_start)
8186                 {
8187                   finish = 0;
8188                   p->prev = 0;
8189                 }
8190               p = p->next;
8191               if (!p)
8192                 break;
8193               push_init_level (2, braced_init_obstack);
8194               p->stack = constructor_stack;
8195               if (p->range_end && tree_int_cst_equal (p->index, p->range_end))
8196                 p->index = p->range_start;
8197             }
8198
8199           if (!finish)
8200             constructor_range_stack = range_stack;
8201           continue;
8202         }
8203
8204       break;
8205     }
8206
8207   constructor_range_stack = 0;
8208 }
8209 \f
8210 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
8211    (guaranteed to be 'volatile' or null) and ARGS (represented using
8212    an ASM_EXPR node).  */
8213 tree
8214 build_asm_stmt (tree cv_qualifier, tree args)
8215 {
8216   if (!ASM_VOLATILE_P (args) && cv_qualifier)
8217     ASM_VOLATILE_P (args) = 1;
8218   return add_stmt (args);
8219 }
8220
8221 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
8222    some INPUTS, and some CLOBBERS.  The latter three may be NULL.
8223    SIMPLE indicates whether there was anything at all after the
8224    string in the asm expression -- asm("blah") and asm("blah" : )
8225    are subtly different.  We use a ASM_EXPR node to represent this.  */
8226 tree
8227 build_asm_expr (location_t loc, tree string, tree outputs, tree inputs,
8228                 tree clobbers, tree labels, bool simple)
8229 {
8230   tree tail;
8231   tree args;
8232   int i;
8233   const char *constraint;
8234   const char **oconstraints;
8235   bool allows_mem, allows_reg, is_inout;
8236   int ninputs, noutputs;
8237
8238   ninputs = list_length (inputs);
8239   noutputs = list_length (outputs);
8240   oconstraints = (const char **) alloca (noutputs * sizeof (const char *));
8241
8242   string = resolve_asm_operand_names (string, outputs, inputs, labels);
8243
8244   /* Remove output conversions that change the type but not the mode.  */
8245   for (i = 0, tail = outputs; tail; ++i, tail = TREE_CHAIN (tail))
8246     {
8247       tree output = TREE_VALUE (tail);
8248
8249       /* ??? Really, this should not be here.  Users should be using a
8250          proper lvalue, dammit.  But there's a long history of using casts
8251          in the output operands.  In cases like longlong.h, this becomes a
8252          primitive form of typechecking -- if the cast can be removed, then
8253          the output operand had a type of the proper width; otherwise we'll
8254          get an error.  Gross, but ...  */
8255       STRIP_NOPS (output);
8256
8257       if (!lvalue_or_else (output, lv_asm))
8258         output = error_mark_node;
8259
8260       if (output != error_mark_node
8261           && (TREE_READONLY (output)
8262               || TYPE_READONLY (TREE_TYPE (output))
8263               || ((TREE_CODE (TREE_TYPE (output)) == RECORD_TYPE
8264                    || TREE_CODE (TREE_TYPE (output)) == UNION_TYPE)
8265                   && C_TYPE_FIELDS_READONLY (TREE_TYPE (output)))))
8266         readonly_error (output, lv_asm);
8267
8268       constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
8269       oconstraints[i] = constraint;
8270
8271       if (parse_output_constraint (&constraint, i, ninputs, noutputs,
8272                                    &allows_mem, &allows_reg, &is_inout))
8273         {
8274           /* If the operand is going to end up in memory,
8275              mark it addressable.  */
8276           if (!allows_reg && !c_mark_addressable (output))
8277             output = error_mark_node;
8278         }
8279       else
8280         output = error_mark_node;
8281
8282       TREE_VALUE (tail) = output;
8283     }
8284
8285   for (i = 0, tail = inputs; tail; ++i, tail = TREE_CHAIN (tail))
8286     {
8287       tree input;
8288
8289       constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
8290       input = TREE_VALUE (tail);
8291
8292       if (parse_input_constraint (&constraint, i, ninputs, noutputs, 0,
8293                                   oconstraints, &allows_mem, &allows_reg))
8294         {
8295           /* If the operand is going to end up in memory,
8296              mark it addressable.  */
8297           if (!allows_reg && allows_mem)
8298             {
8299               /* Strip the nops as we allow this case.  FIXME, this really
8300                  should be rejected or made deprecated.  */
8301               STRIP_NOPS (input);
8302               if (!c_mark_addressable (input))
8303                 input = error_mark_node;
8304           }
8305         }
8306       else
8307         input = error_mark_node;
8308
8309       TREE_VALUE (tail) = input;
8310     }
8311
8312   /* ASMs with labels cannot have outputs.  This should have been
8313      enforced by the parser.  */
8314   gcc_assert (outputs == NULL || labels == NULL);
8315
8316   args = build_stmt (loc, ASM_EXPR, string, outputs, inputs, clobbers, labels);
8317
8318   /* asm statements without outputs, including simple ones, are treated
8319      as volatile.  */
8320   ASM_INPUT_P (args) = simple;
8321   ASM_VOLATILE_P (args) = (noutputs == 0);
8322
8323   return args;
8324 }
8325 \f
8326 /* Generate a goto statement to LABEL.  LOC is the location of the
8327    GOTO.  */
8328
8329 tree
8330 c_finish_goto_label (location_t loc, tree label)
8331 {
8332   tree decl = lookup_label_for_goto (loc, label);
8333   if (!decl)
8334     return NULL_TREE;
8335   TREE_USED (decl) = 1;
8336   {
8337     tree t = build1 (GOTO_EXPR, void_type_node, decl);
8338     SET_EXPR_LOCATION (t, loc);
8339     return add_stmt (t);
8340   }
8341 }
8342
8343 /* Generate a computed goto statement to EXPR.  LOC is the location of
8344    the GOTO.  */
8345
8346 tree
8347 c_finish_goto_ptr (location_t loc, tree expr)
8348 {
8349   tree t;
8350   pedwarn (loc, OPT_pedantic, "ISO C forbids %<goto *expr;%>");
8351   expr = c_fully_fold (expr, false, NULL);
8352   expr = convert (ptr_type_node, expr);
8353   t = build1 (GOTO_EXPR, void_type_node, expr);
8354   SET_EXPR_LOCATION (t, loc);
8355   return add_stmt (t);
8356 }
8357
8358 /* Generate a C `return' statement.  RETVAL is the expression for what
8359    to return, or a null pointer for `return;' with no value.  LOC is
8360    the location of the return statement.  If ORIGTYPE is not NULL_TREE, it
8361    is the original type of RETVAL.  */
8362
8363 tree
8364 c_finish_return (location_t loc, tree retval, tree origtype)
8365 {
8366   tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)), ret_stmt;
8367   bool no_warning = false;
8368   bool npc = false;
8369
8370   if (TREE_THIS_VOLATILE (current_function_decl))
8371     warning_at (loc, 0,
8372                 "function declared %<noreturn%> has a %<return%> statement");
8373
8374   if (retval)
8375     {
8376       tree semantic_type = NULL_TREE;
8377       npc = null_pointer_constant_p (retval);
8378       if (TREE_CODE (retval) == EXCESS_PRECISION_EXPR)
8379         {
8380           semantic_type = TREE_TYPE (retval);
8381           retval = TREE_OPERAND (retval, 0);
8382         }
8383       retval = c_fully_fold (retval, false, NULL);
8384       if (semantic_type)
8385         retval = build1 (EXCESS_PRECISION_EXPR, semantic_type, retval);
8386     }
8387
8388   if (!retval)
8389     {
8390       current_function_returns_null = 1;
8391       if ((warn_return_type || flag_isoc99)
8392           && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE)
8393         {
8394           pedwarn_c99 (loc, flag_isoc99 ? 0 : OPT_Wreturn_type,
8395                        "%<return%> with no value, in "
8396                        "function returning non-void");
8397           no_warning = true;
8398         }
8399     }
8400   else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE)
8401     {
8402       current_function_returns_null = 1;
8403       if (TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
8404         pedwarn (loc, 0,
8405                  "%<return%> with a value, in function returning void");
8406       else
8407         pedwarn (loc, OPT_pedantic, "ISO C forbids "
8408                  "%<return%> with expression, in function returning void");
8409     }
8410   else
8411     {
8412       tree t = convert_for_assignment (loc, valtype, retval, origtype,
8413                                        ic_return,
8414                                        npc, NULL_TREE, NULL_TREE, 0);
8415       tree res = DECL_RESULT (current_function_decl);
8416       tree inner;
8417
8418       current_function_returns_value = 1;
8419       if (t == error_mark_node)
8420         return NULL_TREE;
8421
8422       inner = t = convert (TREE_TYPE (res), t);
8423
8424       /* Strip any conversions, additions, and subtractions, and see if
8425          we are returning the address of a local variable.  Warn if so.  */
8426       while (1)
8427         {
8428           switch (TREE_CODE (inner))
8429             {
8430             CASE_CONVERT:
8431             case NON_LVALUE_EXPR:
8432             case PLUS_EXPR:
8433             case POINTER_PLUS_EXPR:
8434               inner = TREE_OPERAND (inner, 0);
8435               continue;
8436
8437             case MINUS_EXPR:
8438               /* If the second operand of the MINUS_EXPR has a pointer
8439                  type (or is converted from it), this may be valid, so
8440                  don't give a warning.  */
8441               {
8442                 tree op1 = TREE_OPERAND (inner, 1);
8443
8444                 while (!POINTER_TYPE_P (TREE_TYPE (op1))
8445                        && (CONVERT_EXPR_P (op1)
8446                            || TREE_CODE (op1) == NON_LVALUE_EXPR))
8447                   op1 = TREE_OPERAND (op1, 0);
8448
8449                 if (POINTER_TYPE_P (TREE_TYPE (op1)))
8450                   break;
8451
8452                 inner = TREE_OPERAND (inner, 0);
8453                 continue;
8454               }
8455
8456             case ADDR_EXPR:
8457               inner = TREE_OPERAND (inner, 0);
8458
8459               while (REFERENCE_CLASS_P (inner)
8460                      && TREE_CODE (inner) != INDIRECT_REF)
8461                 inner = TREE_OPERAND (inner, 0);
8462
8463               if (DECL_P (inner)
8464                   && !DECL_EXTERNAL (inner)
8465                   && !TREE_STATIC (inner)
8466                   && DECL_CONTEXT (inner) == current_function_decl)
8467                 warning_at (loc,
8468                             0, "function returns address of local variable");
8469               break;
8470
8471             default:
8472               break;
8473             }
8474
8475           break;
8476         }
8477
8478       retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t);
8479       SET_EXPR_LOCATION (retval, loc);
8480
8481       if (warn_sequence_point)
8482         verify_sequence_points (retval);
8483     }
8484
8485   ret_stmt = build_stmt (loc, RETURN_EXPR, retval);
8486   TREE_NO_WARNING (ret_stmt) |= no_warning;
8487   return add_stmt (ret_stmt);
8488 }
8489 \f
8490 struct c_switch {
8491   /* The SWITCH_EXPR being built.  */
8492   tree switch_expr;
8493
8494   /* The original type of the testing expression, i.e. before the
8495      default conversion is applied.  */
8496   tree orig_type;
8497
8498   /* A splay-tree mapping the low element of a case range to the high
8499      element, or NULL_TREE if there is no high element.  Used to
8500      determine whether or not a new case label duplicates an old case
8501      label.  We need a tree, rather than simply a hash table, because
8502      of the GNU case range extension.  */
8503   splay_tree cases;
8504
8505   /* The bindings at the point of the switch.  This is used for
8506      warnings crossing decls when branching to a case label.  */
8507   struct c_spot_bindings *bindings;
8508
8509   /* The next node on the stack.  */
8510   struct c_switch *next;
8511 };
8512
8513 /* A stack of the currently active switch statements.  The innermost
8514    switch statement is on the top of the stack.  There is no need to
8515    mark the stack for garbage collection because it is only active
8516    during the processing of the body of a function, and we never
8517    collect at that point.  */
8518
8519 struct c_switch *c_switch_stack;
8520
8521 /* Start a C switch statement, testing expression EXP.  Return the new
8522    SWITCH_EXPR.  SWITCH_LOC is the location of the `switch'.
8523    SWITCH_COND_LOC is the location of the switch's condition.  */
8524
8525 tree
8526 c_start_case (location_t switch_loc,
8527               location_t switch_cond_loc,
8528               tree exp)
8529 {
8530   tree orig_type = error_mark_node;
8531   struct c_switch *cs;
8532
8533   if (exp != error_mark_node)
8534     {
8535       orig_type = TREE_TYPE (exp);
8536
8537       if (!INTEGRAL_TYPE_P (orig_type))
8538         {
8539           if (orig_type != error_mark_node)
8540             {
8541               error_at (switch_cond_loc, "switch quantity not an integer");
8542               orig_type = error_mark_node;
8543             }
8544           exp = integer_zero_node;
8545         }
8546       else
8547         {
8548           tree type = TYPE_MAIN_VARIANT (orig_type);
8549
8550           if (!in_system_header
8551               && (type == long_integer_type_node
8552                   || type == long_unsigned_type_node))
8553             warning_at (switch_cond_loc,
8554                         OPT_Wtraditional, "%<long%> switch expression not "
8555                         "converted to %<int%> in ISO C");
8556
8557           exp = c_fully_fold (exp, false, NULL);
8558           exp = default_conversion (exp);
8559
8560           if (warn_sequence_point)
8561             verify_sequence_points (exp);
8562         }
8563     }
8564
8565   /* Add this new SWITCH_EXPR to the stack.  */
8566   cs = XNEW (struct c_switch);
8567   cs->switch_expr = build3 (SWITCH_EXPR, orig_type, exp, NULL_TREE, NULL_TREE);
8568   SET_EXPR_LOCATION (cs->switch_expr, switch_loc);
8569   cs->orig_type = orig_type;
8570   cs->cases = splay_tree_new (case_compare, NULL, NULL);
8571   cs->bindings = c_get_switch_bindings ();
8572   cs->next = c_switch_stack;
8573   c_switch_stack = cs;
8574
8575   return add_stmt (cs->switch_expr);
8576 }
8577
8578 /* Process a case label at location LOC.  */
8579
8580 tree
8581 do_case (location_t loc, tree low_value, tree high_value)
8582 {
8583   tree label = NULL_TREE;
8584
8585   if (low_value && TREE_CODE (low_value) != INTEGER_CST)
8586     {
8587       low_value = c_fully_fold (low_value, false, NULL);
8588       if (TREE_CODE (low_value) == INTEGER_CST)
8589         pedwarn (input_location, OPT_pedantic,
8590                  "case label is not an integer constant expression");
8591     }
8592
8593   if (high_value && TREE_CODE (high_value) != INTEGER_CST)
8594     {
8595       high_value = c_fully_fold (high_value, false, NULL);
8596       if (TREE_CODE (high_value) == INTEGER_CST)
8597         pedwarn (input_location, OPT_pedantic,
8598                  "case label is not an integer constant expression");
8599     }
8600
8601   if (c_switch_stack == NULL)
8602     {
8603       if (low_value)
8604         error_at (loc, "case label not within a switch statement");
8605       else
8606         error_at (loc, "%<default%> label not within a switch statement");
8607       return NULL_TREE;
8608     }
8609
8610   if (c_check_switch_jump_warnings (c_switch_stack->bindings,
8611                                     EXPR_LOCATION (c_switch_stack->switch_expr),
8612                                     loc))
8613     return NULL_TREE;
8614
8615   label = c_add_case_label (loc, c_switch_stack->cases,
8616                             SWITCH_COND (c_switch_stack->switch_expr),
8617                             c_switch_stack->orig_type,
8618                             low_value, high_value);
8619   if (label == error_mark_node)
8620     label = NULL_TREE;
8621   return label;
8622 }
8623
8624 /* Finish the switch statement.  */
8625
8626 void
8627 c_finish_case (tree body)
8628 {
8629   struct c_switch *cs = c_switch_stack;
8630   location_t switch_location;
8631
8632   SWITCH_BODY (cs->switch_expr) = body;
8633
8634   /* Emit warnings as needed.  */
8635   switch_location = EXPR_LOCATION (cs->switch_expr);
8636   c_do_switch_warnings (cs->cases, switch_location,
8637                         TREE_TYPE (cs->switch_expr),
8638                         SWITCH_COND (cs->switch_expr));
8639
8640   /* Pop the stack.  */
8641   c_switch_stack = cs->next;
8642   splay_tree_delete (cs->cases);
8643   c_release_switch_bindings (cs->bindings);
8644   XDELETE (cs);
8645 }
8646 \f
8647 /* Emit an if statement.  IF_LOCUS is the location of the 'if'.  COND,
8648    THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
8649    may be null.  NESTED_IF is true if THEN_BLOCK contains another IF
8650    statement, and was not surrounded with parenthesis.  */
8651
8652 void
8653 c_finish_if_stmt (location_t if_locus, tree cond, tree then_block,
8654                   tree else_block, bool nested_if)
8655 {
8656   tree stmt;
8657
8658   /* Diagnose an ambiguous else if if-then-else is nested inside if-then.  */
8659   if (warn_parentheses && nested_if && else_block == NULL)
8660     {
8661       tree inner_if = then_block;
8662
8663       /* We know from the grammar productions that there is an IF nested
8664          within THEN_BLOCK.  Due to labels and c99 conditional declarations,
8665          it might not be exactly THEN_BLOCK, but should be the last
8666          non-container statement within.  */
8667       while (1)
8668         switch (TREE_CODE (inner_if))
8669           {
8670           case COND_EXPR:
8671             goto found;
8672           case BIND_EXPR:
8673             inner_if = BIND_EXPR_BODY (inner_if);
8674             break;
8675           case STATEMENT_LIST:
8676             inner_if = expr_last (then_block);
8677             break;
8678           case TRY_FINALLY_EXPR:
8679           case TRY_CATCH_EXPR:
8680             inner_if = TREE_OPERAND (inner_if, 0);
8681             break;
8682           default:
8683             gcc_unreachable ();
8684           }
8685     found:
8686
8687       if (COND_EXPR_ELSE (inner_if))
8688          warning_at (if_locus, OPT_Wparentheses,
8689                      "suggest explicit braces to avoid ambiguous %<else%>");
8690     }
8691
8692   stmt = build3 (COND_EXPR, void_type_node, cond, then_block, else_block);
8693   SET_EXPR_LOCATION (stmt, if_locus);
8694   add_stmt (stmt);
8695 }
8696
8697 /* Emit a general-purpose loop construct.  START_LOCUS is the location of
8698    the beginning of the loop.  COND is the loop condition.  COND_IS_FIRST
8699    is false for DO loops.  INCR is the FOR increment expression.  BODY is
8700    the statement controlled by the loop.  BLAB is the break label.  CLAB is
8701    the continue label.  Everything is allowed to be NULL.  */
8702
8703 void
8704 c_finish_loop (location_t start_locus, tree cond, tree incr, tree body,
8705                tree blab, tree clab, bool cond_is_first)
8706 {
8707   tree entry = NULL, exit = NULL, t;
8708
8709   /* If the condition is zero don't generate a loop construct.  */
8710   if (cond && integer_zerop (cond))
8711     {
8712       if (cond_is_first)
8713         {
8714           t = build_and_jump (&blab);
8715           SET_EXPR_LOCATION (t, start_locus);
8716           add_stmt (t);
8717         }
8718     }
8719   else
8720     {
8721       tree top = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
8722
8723       /* If we have an exit condition, then we build an IF with gotos either
8724          out of the loop, or to the top of it.  If there's no exit condition,
8725          then we just build a jump back to the top.  */
8726       exit = build_and_jump (&LABEL_EXPR_LABEL (top));
8727
8728       if (cond && !integer_nonzerop (cond))
8729         {
8730           /* Canonicalize the loop condition to the end.  This means
8731              generating a branch to the loop condition.  Reuse the
8732              continue label, if possible.  */
8733           if (cond_is_first)
8734             {
8735               if (incr || !clab)
8736                 {
8737                   entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
8738                   t = build_and_jump (&LABEL_EXPR_LABEL (entry));
8739                 }
8740               else
8741                 t = build1 (GOTO_EXPR, void_type_node, clab);
8742               SET_EXPR_LOCATION (t, start_locus);
8743               add_stmt (t);
8744             }
8745
8746           t = build_and_jump (&blab);
8747           if (cond_is_first)
8748             exit = fold_build3_loc (start_locus,
8749                                 COND_EXPR, void_type_node, cond, exit, t);
8750           else
8751             exit = fold_build3_loc (input_location,
8752                                 COND_EXPR, void_type_node, cond, exit, t);
8753         }
8754
8755       add_stmt (top);
8756     }
8757
8758   if (body)
8759     add_stmt (body);
8760   if (clab)
8761     add_stmt (build1 (LABEL_EXPR, void_type_node, clab));
8762   if (incr)
8763     add_stmt (incr);
8764   if (entry)
8765     add_stmt (entry);
8766   if (exit)
8767     add_stmt (exit);
8768   if (blab)
8769     add_stmt (build1 (LABEL_EXPR, void_type_node, blab));
8770 }
8771
8772 tree
8773 c_finish_bc_stmt (location_t loc, tree *label_p, bool is_break)
8774 {
8775   bool skip;
8776   tree label = *label_p;
8777
8778   /* In switch statements break is sometimes stylistically used after
8779      a return statement.  This can lead to spurious warnings about
8780      control reaching the end of a non-void function when it is
8781      inlined.  Note that we are calling block_may_fallthru with
8782      language specific tree nodes; this works because
8783      block_may_fallthru returns true when given something it does not
8784      understand.  */
8785   skip = !block_may_fallthru (cur_stmt_list);
8786
8787   if (!label)
8788     {
8789       if (!skip)
8790         *label_p = label = create_artificial_label (loc);
8791     }
8792   else if (TREE_CODE (label) == LABEL_DECL)
8793     ;
8794   else switch (TREE_INT_CST_LOW (label))
8795     {
8796     case 0:
8797       if (is_break)
8798         error_at (loc, "break statement not within loop or switch");
8799       else
8800         error_at (loc, "continue statement not within a loop");
8801       return NULL_TREE;
8802
8803     case 1:
8804       gcc_assert (is_break);
8805       error_at (loc, "break statement used with OpenMP for loop");
8806       return NULL_TREE;
8807
8808     default:
8809       gcc_unreachable ();
8810     }
8811
8812   if (skip)
8813     return NULL_TREE;
8814
8815   if (!is_break)
8816     add_stmt (build_predict_expr (PRED_CONTINUE, NOT_TAKEN));
8817
8818   return add_stmt (build1 (GOTO_EXPR, void_type_node, label));
8819 }
8820
8821 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr.  */
8822
8823 static void
8824 emit_side_effect_warnings (location_t loc, tree expr)
8825 {
8826   if (expr == error_mark_node)
8827     ;
8828   else if (!TREE_SIDE_EFFECTS (expr))
8829     {
8830       if (!VOID_TYPE_P (TREE_TYPE (expr)) && !TREE_NO_WARNING (expr))
8831         warning_at (loc, OPT_Wunused_value, "statement with no effect");
8832     }
8833   else
8834     warn_if_unused_value (expr, loc);
8835 }
8836
8837 /* Process an expression as if it were a complete statement.  Emit
8838    diagnostics, but do not call ADD_STMT.  LOC is the location of the
8839    statement.  */
8840
8841 tree
8842 c_process_expr_stmt (location_t loc, tree expr)
8843 {
8844   tree exprv;
8845
8846   if (!expr)
8847     return NULL_TREE;
8848
8849   expr = c_fully_fold (expr, false, NULL);
8850
8851   if (warn_sequence_point)
8852     verify_sequence_points (expr);
8853
8854   if (TREE_TYPE (expr) != error_mark_node
8855       && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr))
8856       && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
8857     error_at (loc, "expression statement has incomplete type");
8858
8859   /* If we're not processing a statement expression, warn about unused values.
8860      Warnings for statement expressions will be emitted later, once we figure
8861      out which is the result.  */
8862   if (!STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
8863       && warn_unused_value)
8864     emit_side_effect_warnings (loc, expr);
8865
8866   exprv = expr;
8867   while (TREE_CODE (exprv) == COMPOUND_EXPR)
8868     exprv = TREE_OPERAND (exprv, 1);
8869   if (DECL_P (exprv) || handled_component_p (exprv))
8870     mark_exp_read (exprv);
8871
8872   /* If the expression is not of a type to which we cannot assign a line
8873      number, wrap the thing in a no-op NOP_EXPR.  */
8874   if (DECL_P (expr) || CONSTANT_CLASS_P (expr))
8875     {
8876       expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr);
8877       SET_EXPR_LOCATION (expr, loc);
8878     }
8879
8880   return expr;
8881 }
8882
8883 /* Emit an expression as a statement.  LOC is the location of the
8884    expression.  */
8885
8886 tree
8887 c_finish_expr_stmt (location_t loc, tree expr)
8888 {
8889   if (expr)
8890     return add_stmt (c_process_expr_stmt (loc, expr));
8891   else
8892     return NULL;
8893 }
8894
8895 /* Do the opposite and emit a statement as an expression.  To begin,
8896    create a new binding level and return it.  */
8897
8898 tree
8899 c_begin_stmt_expr (void)
8900 {
8901   tree ret;
8902
8903   /* We must force a BLOCK for this level so that, if it is not expanded
8904      later, there is a way to turn off the entire subtree of blocks that
8905      are contained in it.  */
8906   keep_next_level ();
8907   ret = c_begin_compound_stmt (true);
8908
8909   c_bindings_start_stmt_expr (c_switch_stack == NULL
8910                               ? NULL
8911                               : c_switch_stack->bindings);
8912
8913   /* Mark the current statement list as belonging to a statement list.  */
8914   STATEMENT_LIST_STMT_EXPR (ret) = 1;
8915
8916   return ret;
8917 }
8918
8919 /* LOC is the location of the compound statement to which this body
8920    belongs.  */
8921
8922 tree
8923 c_finish_stmt_expr (location_t loc, tree body)
8924 {
8925   tree last, type, tmp, val;
8926   tree *last_p;
8927
8928   body = c_end_compound_stmt (loc, body, true);
8929
8930   c_bindings_end_stmt_expr (c_switch_stack == NULL
8931                             ? NULL
8932                             : c_switch_stack->bindings);
8933
8934   /* Locate the last statement in BODY.  See c_end_compound_stmt
8935      about always returning a BIND_EXPR.  */
8936   last_p = &BIND_EXPR_BODY (body);
8937   last = BIND_EXPR_BODY (body);
8938
8939  continue_searching:
8940   if (TREE_CODE (last) == STATEMENT_LIST)
8941     {
8942       tree_stmt_iterator i;
8943
8944       /* This can happen with degenerate cases like ({ }).  No value.  */
8945       if (!TREE_SIDE_EFFECTS (last))
8946         return body;
8947
8948       /* If we're supposed to generate side effects warnings, process
8949          all of the statements except the last.  */
8950       if (warn_unused_value)
8951         {
8952           for (i = tsi_start (last); !tsi_one_before_end_p (i); tsi_next (&i))
8953             {
8954               location_t tloc;
8955               tree t = tsi_stmt (i);
8956
8957               tloc = EXPR_HAS_LOCATION (t) ? EXPR_LOCATION (t) : loc;
8958               emit_side_effect_warnings (tloc, t);
8959             }
8960         }
8961       else
8962         i = tsi_last (last);
8963       last_p = tsi_stmt_ptr (i);
8964       last = *last_p;
8965     }
8966
8967   /* If the end of the list is exception related, then the list was split
8968      by a call to push_cleanup.  Continue searching.  */
8969   if (TREE_CODE (last) == TRY_FINALLY_EXPR
8970       || TREE_CODE (last) == TRY_CATCH_EXPR)
8971     {
8972       last_p = &TREE_OPERAND (last, 0);
8973       last = *last_p;
8974       goto continue_searching;
8975     }
8976
8977   if (last == error_mark_node)
8978     return last;
8979
8980   /* In the case that the BIND_EXPR is not necessary, return the
8981      expression out from inside it.  */
8982   if (last == BIND_EXPR_BODY (body)
8983       && BIND_EXPR_VARS (body) == NULL)
8984     {
8985       /* Even if this looks constant, do not allow it in a constant
8986          expression.  */
8987       last = c_wrap_maybe_const (last, true);
8988       /* Do not warn if the return value of a statement expression is
8989          unused.  */
8990       TREE_NO_WARNING (last) = 1;
8991       return last;
8992     }
8993
8994   /* Extract the type of said expression.  */
8995   type = TREE_TYPE (last);
8996
8997   /* If we're not returning a value at all, then the BIND_EXPR that
8998      we already have is a fine expression to return.  */
8999   if (!type || VOID_TYPE_P (type))
9000     return body;
9001
9002   /* Now that we've located the expression containing the value, it seems
9003      silly to make voidify_wrapper_expr repeat the process.  Create a
9004      temporary of the appropriate type and stick it in a TARGET_EXPR.  */
9005   tmp = create_tmp_var_raw (type, NULL);
9006
9007   /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt.  This avoids
9008      tree_expr_nonnegative_p giving up immediately.  */
9009   val = last;
9010   if (TREE_CODE (val) == NOP_EXPR
9011       && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0)))
9012     val = TREE_OPERAND (val, 0);
9013
9014   *last_p = build2 (MODIFY_EXPR, void_type_node, tmp, val);
9015   SET_EXPR_LOCATION (*last_p, EXPR_LOCATION (last));
9016
9017   {
9018     tree t = build4 (TARGET_EXPR, type, tmp, body, NULL_TREE, NULL_TREE);
9019     SET_EXPR_LOCATION (t, loc);
9020     return t;
9021   }
9022 }
9023 \f
9024 /* Begin and end compound statements.  This is as simple as pushing
9025    and popping new statement lists from the tree.  */
9026
9027 tree
9028 c_begin_compound_stmt (bool do_scope)
9029 {
9030   tree stmt = push_stmt_list ();
9031   if (do_scope)
9032     push_scope ();
9033   return stmt;
9034 }
9035
9036 /* End a compound statement.  STMT is the statement.  LOC is the
9037    location of the compound statement-- this is usually the location
9038    of the opening brace.  */
9039
9040 tree
9041 c_end_compound_stmt (location_t loc, tree stmt, bool do_scope)
9042 {
9043   tree block = NULL;
9044
9045   if (do_scope)
9046     {
9047       if (c_dialect_objc ())
9048         objc_clear_super_receiver ();
9049       block = pop_scope ();
9050     }
9051
9052   stmt = pop_stmt_list (stmt);
9053   stmt = c_build_bind_expr (loc, block, stmt);
9054
9055   /* If this compound statement is nested immediately inside a statement
9056      expression, then force a BIND_EXPR to be created.  Otherwise we'll
9057      do the wrong thing for ({ { 1; } }) or ({ 1; { } }).  In particular,
9058      STATEMENT_LISTs merge, and thus we can lose track of what statement
9059      was really last.  */
9060   if (cur_stmt_list
9061       && STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
9062       && TREE_CODE (stmt) != BIND_EXPR)
9063     {
9064       stmt = build3 (BIND_EXPR, void_type_node, NULL, stmt, NULL);
9065       TREE_SIDE_EFFECTS (stmt) = 1;
9066       SET_EXPR_LOCATION (stmt, loc);
9067     }
9068
9069   return stmt;
9070 }
9071
9072 /* Queue a cleanup.  CLEANUP is an expression/statement to be executed
9073    when the current scope is exited.  EH_ONLY is true when this is not
9074    meant to apply to normal control flow transfer.  */
9075
9076 void
9077 push_cleanup (tree decl, tree cleanup, bool eh_only)
9078 {
9079   enum tree_code code;
9080   tree stmt, list;
9081   bool stmt_expr;
9082
9083   code = eh_only ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR;
9084   stmt = build_stmt (DECL_SOURCE_LOCATION (decl), code, NULL, cleanup);
9085   add_stmt (stmt);
9086   stmt_expr = STATEMENT_LIST_STMT_EXPR (cur_stmt_list);
9087   list = push_stmt_list ();
9088   TREE_OPERAND (stmt, 0) = list;
9089   STATEMENT_LIST_STMT_EXPR (list) = stmt_expr;
9090 }
9091 \f
9092 /* Build a binary-operation expression without default conversions.
9093    CODE is the kind of expression to build.
9094    LOCATION is the operator's location.
9095    This function differs from `build' in several ways:
9096    the data type of the result is computed and recorded in it,
9097    warnings are generated if arg data types are invalid,
9098    special handling for addition and subtraction of pointers is known,
9099    and some optimization is done (operations on narrow ints
9100    are done in the narrower type when that gives the same result).
9101    Constant folding is also done before the result is returned.
9102
9103    Note that the operands will never have enumeral types, or function
9104    or array types, because either they will have the default conversions
9105    performed or they have both just been converted to some other type in which
9106    the arithmetic is to be done.  */
9107
9108 tree
9109 build_binary_op (location_t location, enum tree_code code,
9110                  tree orig_op0, tree orig_op1, int convert_p)
9111 {
9112   tree type0, type1, orig_type0, orig_type1;
9113   tree eptype;
9114   enum tree_code code0, code1;
9115   tree op0, op1;
9116   tree ret = error_mark_node;
9117   const char *invalid_op_diag;
9118   bool op0_int_operands, op1_int_operands;
9119   bool int_const, int_const_or_overflow, int_operands;
9120
9121   /* Expression code to give to the expression when it is built.
9122      Normally this is CODE, which is what the caller asked for,
9123      but in some special cases we change it.  */
9124   enum tree_code resultcode = code;
9125
9126   /* Data type in which the computation is to be performed.
9127      In the simplest cases this is the common type of the arguments.  */
9128   tree result_type = NULL;
9129
9130   /* When the computation is in excess precision, the type of the
9131      final EXCESS_PRECISION_EXPR.  */
9132   tree semantic_result_type = NULL;
9133
9134   /* Nonzero means operands have already been type-converted
9135      in whatever way is necessary.
9136      Zero means they need to be converted to RESULT_TYPE.  */
9137   int converted = 0;
9138
9139   /* Nonzero means create the expression with this type, rather than
9140      RESULT_TYPE.  */
9141   tree build_type = 0;
9142
9143   /* Nonzero means after finally constructing the expression
9144      convert it to this type.  */
9145   tree final_type = 0;
9146
9147   /* Nonzero if this is an operation like MIN or MAX which can
9148      safely be computed in short if both args are promoted shorts.
9149      Also implies COMMON.
9150      -1 indicates a bitwise operation; this makes a difference
9151      in the exact conditions for when it is safe to do the operation
9152      in a narrower mode.  */
9153   int shorten = 0;
9154
9155   /* Nonzero if this is a comparison operation;
9156      if both args are promoted shorts, compare the original shorts.
9157      Also implies COMMON.  */
9158   int short_compare = 0;
9159
9160   /* Nonzero if this is a right-shift operation, which can be computed on the
9161      original short and then promoted if the operand is a promoted short.  */
9162   int short_shift = 0;
9163
9164   /* Nonzero means set RESULT_TYPE to the common type of the args.  */
9165   int common = 0;
9166
9167   /* True means types are compatible as far as ObjC is concerned.  */
9168   bool objc_ok;
9169
9170   /* True means this is an arithmetic operation that may need excess
9171      precision.  */
9172   bool may_need_excess_precision;
9173
9174   if (location == UNKNOWN_LOCATION)
9175     location = input_location;
9176
9177   op0 = orig_op0;
9178   op1 = orig_op1;
9179
9180   op0_int_operands = EXPR_INT_CONST_OPERANDS (orig_op0);
9181   if (op0_int_operands)
9182     op0 = remove_c_maybe_const_expr (op0);
9183   op1_int_operands = EXPR_INT_CONST_OPERANDS (orig_op1);
9184   if (op1_int_operands)
9185     op1 = remove_c_maybe_const_expr (op1);
9186   int_operands = (op0_int_operands && op1_int_operands);
9187   if (int_operands)
9188     {
9189       int_const_or_overflow = (TREE_CODE (orig_op0) == INTEGER_CST
9190                                && TREE_CODE (orig_op1) == INTEGER_CST);
9191       int_const = (int_const_or_overflow
9192                    && !TREE_OVERFLOW (orig_op0)
9193                    && !TREE_OVERFLOW (orig_op1));
9194     }
9195   else
9196     int_const = int_const_or_overflow = false;
9197
9198   if (convert_p)
9199     {
9200       op0 = default_conversion (op0);
9201       op1 = default_conversion (op1);
9202     }
9203
9204   orig_type0 = type0 = TREE_TYPE (op0);
9205   orig_type1 = type1 = TREE_TYPE (op1);
9206
9207   /* The expression codes of the data types of the arguments tell us
9208      whether the arguments are integers, floating, pointers, etc.  */
9209   code0 = TREE_CODE (type0);
9210   code1 = TREE_CODE (type1);
9211
9212   /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue.  */
9213   STRIP_TYPE_NOPS (op0);
9214   STRIP_TYPE_NOPS (op1);
9215
9216   /* If an error was already reported for one of the arguments,
9217      avoid reporting another error.  */
9218
9219   if (code0 == ERROR_MARK || code1 == ERROR_MARK)
9220     return error_mark_node;
9221
9222   if ((invalid_op_diag
9223        = targetm.invalid_binary_op (code, type0, type1)))
9224     {
9225       error_at (location, invalid_op_diag);
9226       return error_mark_node;
9227     }
9228
9229   switch (code)
9230     {
9231     case PLUS_EXPR:
9232     case MINUS_EXPR:
9233     case MULT_EXPR:
9234     case TRUNC_DIV_EXPR:
9235     case CEIL_DIV_EXPR:
9236     case FLOOR_DIV_EXPR:
9237     case ROUND_DIV_EXPR:
9238     case EXACT_DIV_EXPR:
9239       may_need_excess_precision = true;
9240       break;
9241     default:
9242       may_need_excess_precision = false;
9243       break;
9244     }
9245   if (TREE_CODE (op0) == EXCESS_PRECISION_EXPR)
9246     {
9247       op0 = TREE_OPERAND (op0, 0);
9248       type0 = TREE_TYPE (op0);
9249     }
9250   else if (may_need_excess_precision
9251            && (eptype = excess_precision_type (type0)) != NULL_TREE)
9252     {
9253       type0 = eptype;
9254       op0 = convert (eptype, op0);
9255     }
9256   if (TREE_CODE (op1) == EXCESS_PRECISION_EXPR)
9257     {
9258       op1 = TREE_OPERAND (op1, 0);
9259       type1 = TREE_TYPE (op1);
9260     }
9261   else if (may_need_excess_precision
9262            && (eptype = excess_precision_type (type1)) != NULL_TREE)
9263     {
9264       type1 = eptype;
9265       op1 = convert (eptype, op1);
9266     }
9267
9268   objc_ok = objc_compare_types (type0, type1, -3, NULL_TREE);
9269
9270   switch (code)
9271     {
9272     case PLUS_EXPR:
9273       /* Handle the pointer + int case.  */
9274       if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
9275         {
9276           ret = pointer_int_sum (location, PLUS_EXPR, op0, op1);
9277           goto return_build_binary_op;
9278         }
9279       else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
9280         {
9281           ret = pointer_int_sum (location, PLUS_EXPR, op1, op0);
9282           goto return_build_binary_op;
9283         }
9284       else
9285         common = 1;
9286       break;
9287
9288     case MINUS_EXPR:
9289       /* Subtraction of two similar pointers.
9290          We must subtract them as integers, then divide by object size.  */
9291       if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
9292           && comp_target_types (location, type0, type1))
9293         {
9294           ret = pointer_diff (location, op0, op1);
9295           goto return_build_binary_op;
9296         }
9297       /* Handle pointer minus int.  Just like pointer plus int.  */
9298       else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
9299         {
9300           ret = pointer_int_sum (location, MINUS_EXPR, op0, op1);
9301           goto return_build_binary_op;
9302         }
9303       else
9304         common = 1;
9305       break;
9306
9307     case MULT_EXPR:
9308       common = 1;
9309       break;
9310
9311     case TRUNC_DIV_EXPR:
9312     case CEIL_DIV_EXPR:
9313     case FLOOR_DIV_EXPR:
9314     case ROUND_DIV_EXPR:
9315     case EXACT_DIV_EXPR:
9316       warn_for_div_by_zero (location, op1);
9317
9318       if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
9319            || code0 == FIXED_POINT_TYPE
9320            || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
9321           && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
9322               || code1 == FIXED_POINT_TYPE
9323               || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
9324         {
9325           enum tree_code tcode0 = code0, tcode1 = code1;
9326
9327           if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
9328             tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
9329           if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
9330             tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
9331
9332           if (!((tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE)
9333               || (tcode0 == FIXED_POINT_TYPE && tcode1 == FIXED_POINT_TYPE)))
9334             resultcode = RDIV_EXPR;
9335           else
9336             /* Although it would be tempting to shorten always here, that
9337                loses on some targets, since the modulo instruction is
9338                undefined if the quotient can't be represented in the
9339                computation mode.  We shorten only if unsigned or if
9340                dividing by something we know != -1.  */
9341             shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
9342                        || (TREE_CODE (op1) == INTEGER_CST
9343                            && !integer_all_onesp (op1)));
9344           common = 1;
9345         }
9346       break;
9347
9348     case BIT_AND_EXPR:
9349     case BIT_IOR_EXPR:
9350     case BIT_XOR_EXPR:
9351       if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
9352         shorten = -1;
9353       /* Allow vector types which are not floating point types.   */
9354       else if (code0 == VECTOR_TYPE
9355                && code1 == VECTOR_TYPE
9356                && !VECTOR_FLOAT_TYPE_P (type0)
9357                && !VECTOR_FLOAT_TYPE_P (type1))
9358         common = 1;
9359       break;
9360
9361     case TRUNC_MOD_EXPR:
9362     case FLOOR_MOD_EXPR:
9363       warn_for_div_by_zero (location, op1);
9364
9365       if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
9366           && TREE_CODE (TREE_TYPE (type0)) == INTEGER_TYPE
9367           && TREE_CODE (TREE_TYPE (type1)) == INTEGER_TYPE)
9368         common = 1;
9369       else if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
9370         {
9371           /* Although it would be tempting to shorten always here, that loses
9372              on some targets, since the modulo instruction is undefined if the
9373              quotient can't be represented in the computation mode.  We shorten
9374              only if unsigned or if dividing by something we know != -1.  */
9375           shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
9376                      || (TREE_CODE (op1) == INTEGER_CST
9377                          && !integer_all_onesp (op1)));
9378           common = 1;
9379         }
9380       break;
9381
9382     case TRUTH_ANDIF_EXPR:
9383     case TRUTH_ORIF_EXPR:
9384     case TRUTH_AND_EXPR:
9385     case TRUTH_OR_EXPR:
9386     case TRUTH_XOR_EXPR:
9387       if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE
9388            || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
9389            || code0 == FIXED_POINT_TYPE)
9390           && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE
9391               || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
9392               || code1 == FIXED_POINT_TYPE))
9393         {
9394           /* Result of these operations is always an int,
9395              but that does not mean the operands should be
9396              converted to ints!  */
9397           result_type = integer_type_node;
9398           op0 = c_common_truthvalue_conversion (location, op0);
9399           op1 = c_common_truthvalue_conversion (location, op1);
9400           converted = 1;
9401         }
9402       if (code == TRUTH_ANDIF_EXPR)
9403         {
9404           int_const_or_overflow = (int_operands
9405                                    && TREE_CODE (orig_op0) == INTEGER_CST
9406                                    && (op0 == truthvalue_false_node
9407                                        || TREE_CODE (orig_op1) == INTEGER_CST));
9408           int_const = (int_const_or_overflow
9409                        && !TREE_OVERFLOW (orig_op0)
9410                        && (op0 == truthvalue_false_node
9411                            || !TREE_OVERFLOW (orig_op1)));
9412         }
9413       else if (code == TRUTH_ORIF_EXPR)
9414         {
9415           int_const_or_overflow = (int_operands
9416                                    && TREE_CODE (orig_op0) == INTEGER_CST
9417                                    && (op0 == truthvalue_true_node
9418                                        || TREE_CODE (orig_op1) == INTEGER_CST));
9419           int_const = (int_const_or_overflow
9420                        && !TREE_OVERFLOW (orig_op0)
9421                        && (op0 == truthvalue_true_node
9422                            || !TREE_OVERFLOW (orig_op1)));
9423         }
9424       break;
9425
9426       /* Shift operations: result has same type as first operand;
9427          always convert second operand to int.
9428          Also set SHORT_SHIFT if shifting rightward.  */
9429
9430     case RSHIFT_EXPR:
9431       if ((code0 == INTEGER_TYPE || code0 == FIXED_POINT_TYPE)
9432           && code1 == INTEGER_TYPE)
9433         {
9434           if (TREE_CODE (op1) == INTEGER_CST)
9435             {
9436               if (tree_int_cst_sgn (op1) < 0)
9437                 {
9438                   int_const = false;
9439                   if (c_inhibit_evaluation_warnings == 0)
9440                     warning (0, "right shift count is negative");
9441                 }
9442               else
9443                 {
9444                   if (!integer_zerop (op1))
9445                     short_shift = 1;
9446
9447                   if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
9448                     {
9449                       int_const = false;
9450                       if (c_inhibit_evaluation_warnings == 0)
9451                         warning (0, "right shift count >= width of type");
9452                     }
9453                 }
9454             }
9455
9456           /* Use the type of the value to be shifted.  */
9457           result_type = type0;
9458           /* Convert the shift-count to an integer, regardless of size
9459              of value being shifted.  */
9460           if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
9461             op1 = convert (integer_type_node, op1);
9462           /* Avoid converting op1 to result_type later.  */
9463           converted = 1;
9464         }
9465       break;
9466
9467     case LSHIFT_EXPR:
9468       if ((code0 == INTEGER_TYPE || code0 == FIXED_POINT_TYPE)
9469           && code1 == INTEGER_TYPE)
9470         {
9471           if (TREE_CODE (op1) == INTEGER_CST)
9472             {
9473               if (tree_int_cst_sgn (op1) < 0)
9474                 {
9475                   int_const = false;
9476                   if (c_inhibit_evaluation_warnings == 0)
9477                     warning (0, "left shift count is negative");
9478                 }
9479
9480               else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
9481                 {
9482                   int_const = false;
9483                   if (c_inhibit_evaluation_warnings == 0)
9484                     warning (0, "left shift count >= width of type");
9485                 }
9486             }
9487
9488           /* Use the type of the value to be shifted.  */
9489           result_type = type0;
9490           /* Convert the shift-count to an integer, regardless of size
9491              of value being shifted.  */
9492           if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
9493             op1 = convert (integer_type_node, op1);
9494           /* Avoid converting op1 to result_type later.  */
9495           converted = 1;
9496         }
9497       break;
9498
9499     case EQ_EXPR:
9500     case NE_EXPR:
9501       if (FLOAT_TYPE_P (type0) || FLOAT_TYPE_P (type1))
9502         warning_at (location,
9503                     OPT_Wfloat_equal,
9504                     "comparing floating point with == or != is unsafe");
9505       /* Result of comparison is always int,
9506          but don't convert the args to int!  */
9507       build_type = integer_type_node;
9508       if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
9509            || code0 == FIXED_POINT_TYPE || code0 == COMPLEX_TYPE)
9510           && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
9511               || code1 == FIXED_POINT_TYPE || code1 == COMPLEX_TYPE))
9512         short_compare = 1;
9513       else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
9514         {
9515           if (TREE_CODE (op0) == ADDR_EXPR
9516               && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
9517             {
9518               if (code == EQ_EXPR)
9519                 warning_at (location,
9520                             OPT_Waddress,
9521                             "the comparison will always evaluate as %<false%> "
9522                             "for the address of %qD will never be NULL",
9523                             TREE_OPERAND (op0, 0));
9524               else
9525                 warning_at (location,
9526                             OPT_Waddress,
9527                             "the comparison will always evaluate as %<true%> "
9528                             "for the address of %qD will never be NULL",
9529                             TREE_OPERAND (op0, 0));
9530             }
9531           result_type = type0;
9532         }
9533       else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
9534         {
9535           if (TREE_CODE (op1) == ADDR_EXPR
9536               && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
9537             {
9538               if (code == EQ_EXPR)
9539                 warning_at (location,
9540                             OPT_Waddress,
9541                             "the comparison will always evaluate as %<false%> "
9542                             "for the address of %qD will never be NULL",
9543                             TREE_OPERAND (op1, 0));
9544               else
9545                 warning_at (location,
9546                             OPT_Waddress,
9547                             "the comparison will always evaluate as %<true%> "
9548                             "for the address of %qD will never be NULL",
9549                             TREE_OPERAND (op1, 0));
9550             }
9551           result_type = type1;
9552         }
9553       else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
9554         {
9555           tree tt0 = TREE_TYPE (type0);
9556           tree tt1 = TREE_TYPE (type1);
9557           addr_space_t as0 = TYPE_ADDR_SPACE (tt0);
9558           addr_space_t as1 = TYPE_ADDR_SPACE (tt1);
9559           addr_space_t as_common = ADDR_SPACE_GENERIC;
9560
9561           /* Anything compares with void *.  void * compares with anything.
9562              Otherwise, the targets must be compatible
9563              and both must be object or both incomplete.  */
9564           if (comp_target_types (location, type0, type1))
9565             result_type = common_pointer_type (type0, type1);
9566           else if (!addr_space_superset (as0, as1, &as_common))
9567             {
9568               error_at (location, "comparison of pointers to "
9569                         "disjoint address spaces");
9570               return error_mark_node;
9571             }
9572           else if (VOID_TYPE_P (tt0))
9573             {
9574               if (pedantic && TREE_CODE (tt1) == FUNCTION_TYPE)
9575                 pedwarn (location, OPT_pedantic, "ISO C forbids "
9576                          "comparison of %<void *%> with function pointer");
9577             }
9578           else if (VOID_TYPE_P (tt1))
9579             {
9580               if (pedantic && TREE_CODE (tt0) == FUNCTION_TYPE)
9581                 pedwarn (location, OPT_pedantic, "ISO C forbids "
9582                          "comparison of %<void *%> with function pointer");
9583             }
9584           else
9585             /* Avoid warning about the volatile ObjC EH puts on decls.  */
9586             if (!objc_ok)
9587               pedwarn (location, 0,
9588                        "comparison of distinct pointer types lacks a cast");
9589
9590           if (result_type == NULL_TREE)
9591             {
9592               int qual = ENCODE_QUAL_ADDR_SPACE (as_common);
9593               result_type = build_pointer_type
9594                               (build_qualified_type (void_type_node, qual));
9595             }
9596         }
9597       else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
9598         {
9599           result_type = type0;
9600           pedwarn (location, 0, "comparison between pointer and integer");
9601         }
9602       else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
9603         {
9604           result_type = type1;
9605           pedwarn (location, 0, "comparison between pointer and integer");
9606         }
9607       break;
9608
9609     case LE_EXPR:
9610     case GE_EXPR:
9611     case LT_EXPR:
9612     case GT_EXPR:
9613       build_type = integer_type_node;
9614       if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
9615            || code0 == FIXED_POINT_TYPE)
9616           && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
9617               || code1 == FIXED_POINT_TYPE))
9618         short_compare = 1;
9619       else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
9620         {
9621           addr_space_t as0 = TYPE_ADDR_SPACE (TREE_TYPE (type0));
9622           addr_space_t as1 = TYPE_ADDR_SPACE (TREE_TYPE (type1));
9623           addr_space_t as_common;
9624
9625           if (comp_target_types (location, type0, type1))
9626             {
9627               result_type = common_pointer_type (type0, type1);
9628               if (!COMPLETE_TYPE_P (TREE_TYPE (type0))
9629                   != !COMPLETE_TYPE_P (TREE_TYPE (type1)))
9630                 pedwarn (location, 0,
9631                          "comparison of complete and incomplete pointers");
9632               else if (TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE)
9633                 pedwarn (location, OPT_pedantic, "ISO C forbids "
9634                          "ordered comparisons of pointers to functions");
9635               else if (null_pointer_constant_p (orig_op0)
9636                        || null_pointer_constant_p (orig_op1))
9637                 warning_at (location, OPT_Wextra,
9638                             "ordered comparison of pointer with null pointer");
9639
9640             }
9641           else if (!addr_space_superset (as0, as1, &as_common))
9642             {
9643               error_at (location, "comparison of pointers to "
9644                         "disjoint address spaces");
9645               return error_mark_node;
9646             }
9647           else
9648             {
9649               int qual = ENCODE_QUAL_ADDR_SPACE (as_common);
9650               result_type = build_pointer_type
9651                               (build_qualified_type (void_type_node, qual));
9652               pedwarn (location, 0,
9653                        "comparison of distinct pointer types lacks a cast");
9654             }
9655         }
9656       else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
9657         {
9658           result_type = type0;
9659           if (pedantic)
9660             pedwarn (location, OPT_pedantic,
9661                      "ordered comparison of pointer with integer zero");
9662           else if (extra_warnings)
9663             warning_at (location, OPT_Wextra,
9664                         "ordered comparison of pointer with integer zero");
9665         }
9666       else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
9667         {
9668           result_type = type1;
9669           if (pedantic)
9670             pedwarn (location, OPT_pedantic,
9671                      "ordered comparison of pointer with integer zero");
9672           else if (extra_warnings)
9673             warning_at (location, OPT_Wextra,
9674                         "ordered comparison of pointer with integer zero");
9675         }
9676       else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
9677         {
9678           result_type = type0;
9679           pedwarn (location, 0, "comparison between pointer and integer");
9680         }
9681       else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
9682         {
9683           result_type = type1;
9684           pedwarn (location, 0, "comparison between pointer and integer");
9685         }
9686       break;
9687
9688     default:
9689       gcc_unreachable ();
9690     }
9691
9692   if (code0 == ERROR_MARK || code1 == ERROR_MARK)
9693     return error_mark_node;
9694
9695   if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
9696       && (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
9697           || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
9698                                                     TREE_TYPE (type1))))
9699     {
9700       binary_op_error (location, code, type0, type1);
9701       return error_mark_node;
9702     }
9703
9704   if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
9705        || code0 == FIXED_POINT_TYPE || code0 == VECTOR_TYPE)
9706       &&
9707       (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
9708        || code1 == FIXED_POINT_TYPE || code1 == VECTOR_TYPE))
9709     {
9710       bool first_complex = (code0 == COMPLEX_TYPE);
9711       bool second_complex = (code1 == COMPLEX_TYPE);
9712       int none_complex = (!first_complex && !second_complex);
9713
9714       if (shorten || common || short_compare)
9715         {
9716           result_type = c_common_type (type0, type1);
9717           if (result_type == error_mark_node)
9718             return error_mark_node;
9719         }
9720
9721       if (first_complex != second_complex
9722           && (code == PLUS_EXPR
9723               || code == MINUS_EXPR
9724               || code == MULT_EXPR
9725               || (code == TRUNC_DIV_EXPR && first_complex))
9726           && TREE_CODE (TREE_TYPE (result_type)) == REAL_TYPE
9727           && flag_signed_zeros)
9728         {
9729           /* An operation on mixed real/complex operands must be
9730              handled specially, but the language-independent code can
9731              more easily optimize the plain complex arithmetic if
9732              -fno-signed-zeros.  */
9733           tree real_type = TREE_TYPE (result_type);
9734           tree real, imag;
9735           if (type0 != orig_type0 || type1 != orig_type1)
9736             {
9737               gcc_assert (may_need_excess_precision && common);
9738               semantic_result_type = c_common_type (orig_type0, orig_type1);
9739             }
9740           if (first_complex)
9741             {
9742               if (TREE_TYPE (op0) != result_type)
9743                 op0 = convert_and_check (result_type, op0);
9744               if (TREE_TYPE (op1) != real_type)
9745                 op1 = convert_and_check (real_type, op1);
9746             }
9747           else
9748             {
9749               if (TREE_TYPE (op0) != real_type)
9750                 op0 = convert_and_check (real_type, op0);
9751               if (TREE_TYPE (op1) != result_type)
9752                 op1 = convert_and_check (result_type, op1);
9753             }
9754           if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK)
9755             return error_mark_node;
9756           if (first_complex)
9757             {
9758               op0 = c_save_expr (op0);
9759               real = build_unary_op (EXPR_LOCATION (orig_op0), REALPART_EXPR,
9760                                      op0, 1);
9761               imag = build_unary_op (EXPR_LOCATION (orig_op0), IMAGPART_EXPR,
9762                                      op0, 1);
9763               switch (code)
9764                 {
9765                 case MULT_EXPR:
9766                 case TRUNC_DIV_EXPR:
9767                   imag = build2 (resultcode, real_type, imag, op1);
9768                   /* Fall through.  */
9769                 case PLUS_EXPR:
9770                 case MINUS_EXPR:
9771                   real = build2 (resultcode, real_type, real, op1);
9772                   break;
9773                 default:
9774                   gcc_unreachable();
9775                 }
9776             }
9777           else
9778             {
9779               op1 = c_save_expr (op1);
9780               real = build_unary_op (EXPR_LOCATION (orig_op1), REALPART_EXPR,
9781                                      op1, 1);
9782               imag = build_unary_op (EXPR_LOCATION (orig_op1), IMAGPART_EXPR,
9783                                      op1, 1);
9784               switch (code)
9785                 {
9786                 case MULT_EXPR:
9787                   imag = build2 (resultcode, real_type, op0, imag);
9788                   /* Fall through.  */
9789                 case PLUS_EXPR:
9790                   real = build2 (resultcode, real_type, op0, real);
9791                   break;
9792                 case MINUS_EXPR:
9793                   real = build2 (resultcode, real_type, op0, real);
9794                   imag = build1 (NEGATE_EXPR, real_type, imag);
9795                   break;
9796                 default:
9797                   gcc_unreachable();
9798                 }
9799             }
9800           ret = build2 (COMPLEX_EXPR, result_type, real, imag);
9801           goto return_build_binary_op;
9802         }
9803
9804       /* For certain operations (which identify themselves by shorten != 0)
9805          if both args were extended from the same smaller type,
9806          do the arithmetic in that type and then extend.
9807
9808          shorten !=0 and !=1 indicates a bitwise operation.
9809          For them, this optimization is safe only if
9810          both args are zero-extended or both are sign-extended.
9811          Otherwise, we might change the result.
9812          Eg, (short)-1 | (unsigned short)-1 is (int)-1
9813          but calculated in (unsigned short) it would be (unsigned short)-1.  */
9814
9815       if (shorten && none_complex)
9816         {
9817           final_type = result_type;
9818           result_type = shorten_binary_op (result_type, op0, op1,
9819                                            shorten == -1);
9820         }
9821
9822       /* Shifts can be shortened if shifting right.  */
9823
9824       if (short_shift)
9825         {
9826           int unsigned_arg;
9827           tree arg0 = get_narrower (op0, &unsigned_arg);
9828
9829           final_type = result_type;
9830
9831           if (arg0 == op0 && final_type == TREE_TYPE (op0))
9832             unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
9833
9834           if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
9835               && tree_int_cst_sgn (op1) > 0
9836               /* We can shorten only if the shift count is less than the
9837                  number of bits in the smaller type size.  */
9838               && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
9839               /* We cannot drop an unsigned shift after sign-extension.  */
9840               && (!TYPE_UNSIGNED (final_type) || unsigned_arg))
9841             {
9842               /* Do an unsigned shift if the operand was zero-extended.  */
9843               result_type
9844                 = c_common_signed_or_unsigned_type (unsigned_arg,
9845                                                     TREE_TYPE (arg0));
9846               /* Convert value-to-be-shifted to that type.  */
9847               if (TREE_TYPE (op0) != result_type)
9848                 op0 = convert (result_type, op0);
9849               converted = 1;
9850             }
9851         }
9852
9853       /* Comparison operations are shortened too but differently.
9854          They identify themselves by setting short_compare = 1.  */
9855
9856       if (short_compare)
9857         {
9858           /* Don't write &op0, etc., because that would prevent op0
9859              from being kept in a register.
9860              Instead, make copies of the our local variables and
9861              pass the copies by reference, then copy them back afterward.  */
9862           tree xop0 = op0, xop1 = op1, xresult_type = result_type;
9863           enum tree_code xresultcode = resultcode;
9864           tree val
9865             = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
9866
9867           if (val != 0)
9868             {
9869               ret = val;
9870               goto return_build_binary_op;
9871             }
9872
9873           op0 = xop0, op1 = xop1;
9874           converted = 1;
9875           resultcode = xresultcode;
9876
9877           if (c_inhibit_evaluation_warnings == 0)
9878             {
9879               bool op0_maybe_const = true;
9880               bool op1_maybe_const = true;
9881               tree orig_op0_folded, orig_op1_folded;
9882
9883               if (in_late_binary_op)
9884                 {
9885                   orig_op0_folded = orig_op0;
9886                   orig_op1_folded = orig_op1;
9887                 }
9888               else
9889                 {
9890                   /* Fold for the sake of possible warnings, as in
9891                      build_conditional_expr.  This requires the
9892                      "original" values to be folded, not just op0 and
9893                      op1.  */
9894                   c_inhibit_evaluation_warnings++;
9895                   op0 = c_fully_fold (op0, require_constant_value,
9896                                       &op0_maybe_const);
9897                   op1 = c_fully_fold (op1, require_constant_value,
9898                                       &op1_maybe_const);
9899                   c_inhibit_evaluation_warnings--;
9900                   orig_op0_folded = c_fully_fold (orig_op0,
9901                                                   require_constant_value,
9902                                                   NULL);
9903                   orig_op1_folded = c_fully_fold (orig_op1,
9904                                                   require_constant_value,
9905                                                   NULL);
9906                 }
9907
9908               if (warn_sign_compare)
9909                 warn_for_sign_compare (location, orig_op0_folded,
9910                                        orig_op1_folded, op0, op1,
9911                                        result_type, resultcode);
9912               if (!in_late_binary_op)
9913                 {
9914                   if (!op0_maybe_const || TREE_CODE (op0) != INTEGER_CST)
9915                     op0 = c_wrap_maybe_const (op0, !op0_maybe_const);
9916                   if (!op1_maybe_const || TREE_CODE (op1) != INTEGER_CST)
9917                     op1 = c_wrap_maybe_const (op1, !op1_maybe_const);
9918                 }
9919             }
9920         }
9921     }
9922
9923   /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
9924      If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
9925      Then the expression will be built.
9926      It will be given type FINAL_TYPE if that is nonzero;
9927      otherwise, it will be given type RESULT_TYPE.  */
9928
9929   if (!result_type)
9930     {
9931       binary_op_error (location, code, TREE_TYPE (op0), TREE_TYPE (op1));
9932       return error_mark_node;
9933     }
9934
9935   if (build_type == NULL_TREE)
9936     {
9937       build_type = result_type;
9938       if (type0 != orig_type0 || type1 != orig_type1)
9939         {
9940           gcc_assert (may_need_excess_precision && common);
9941           semantic_result_type = c_common_type (orig_type0, orig_type1);
9942         }
9943     }
9944
9945   if (!converted)
9946     {
9947       op0 = ep_convert_and_check (result_type, op0, semantic_result_type);
9948       op1 = ep_convert_and_check (result_type, op1, semantic_result_type);
9949
9950       /* This can happen if one operand has a vector type, and the other
9951          has a different type.  */
9952       if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK)
9953         return error_mark_node;
9954     }
9955
9956   /* Treat expressions in initializers specially as they can't trap.  */
9957   if (int_const_or_overflow)
9958     ret = (require_constant_value
9959            ? fold_build2_initializer_loc (location, resultcode, build_type,
9960                                           op0, op1)
9961            : fold_build2_loc (location, resultcode, build_type, op0, op1));
9962   else
9963     ret = build2 (resultcode, build_type, op0, op1);
9964   if (final_type != 0)
9965     ret = convert (final_type, ret);
9966
9967  return_build_binary_op:
9968   gcc_assert (ret != error_mark_node);
9969   if (TREE_CODE (ret) == INTEGER_CST && !TREE_OVERFLOW (ret) && !int_const)
9970     ret = (int_operands
9971            ? note_integer_operands (ret)
9972            : build1 (NOP_EXPR, TREE_TYPE (ret), ret));
9973   else if (TREE_CODE (ret) != INTEGER_CST && int_operands
9974            && !in_late_binary_op)
9975     ret = note_integer_operands (ret);
9976   if (semantic_result_type)
9977     ret = build1 (EXCESS_PRECISION_EXPR, semantic_result_type, ret);
9978   protected_set_expr_location (ret, location);
9979   return ret;
9980 }
9981
9982
9983 /* Convert EXPR to be a truth-value, validating its type for this
9984    purpose.  LOCATION is the source location for the expression.  */
9985
9986 tree
9987 c_objc_common_truthvalue_conversion (location_t location, tree expr)
9988 {
9989   bool int_const, int_operands;
9990
9991   switch (TREE_CODE (TREE_TYPE (expr)))
9992     {
9993     case ARRAY_TYPE:
9994       error_at (location, "used array that cannot be converted to pointer where scalar is required");
9995       return error_mark_node;
9996
9997     case RECORD_TYPE:
9998       error_at (location, "used struct type value where scalar is required");
9999       return error_mark_node;
10000
10001     case UNION_TYPE:
10002       error_at (location, "used union type value where scalar is required");
10003       return error_mark_node;
10004
10005     case FUNCTION_TYPE:
10006       gcc_unreachable ();
10007
10008     default:
10009       break;
10010     }
10011
10012   int_const = (TREE_CODE (expr) == INTEGER_CST && !TREE_OVERFLOW (expr));
10013   int_operands = EXPR_INT_CONST_OPERANDS (expr);
10014   if (int_operands)
10015     expr = remove_c_maybe_const_expr (expr);
10016
10017   /* ??? Should we also give an error for void and vectors rather than
10018      leaving those to give errors later?  */
10019   expr = c_common_truthvalue_conversion (location, expr);
10020
10021   if (TREE_CODE (expr) == INTEGER_CST && int_operands && !int_const)
10022     {
10023       if (TREE_OVERFLOW (expr))
10024         return expr;
10025       else
10026         return note_integer_operands (expr);
10027     }
10028   if (TREE_CODE (expr) == INTEGER_CST && !int_const)
10029     return build1 (NOP_EXPR, TREE_TYPE (expr), expr);
10030   return expr;
10031 }
10032 \f
10033
10034 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
10035    required.  */
10036
10037 tree
10038 c_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED, bool *se)
10039 {
10040   if (TREE_CODE (expr) == COMPOUND_LITERAL_EXPR)
10041     {
10042       tree decl = COMPOUND_LITERAL_EXPR_DECL (expr);
10043       /* Executing a compound literal inside a function reinitializes
10044          it.  */
10045       if (!TREE_STATIC (decl))
10046         *se = true;
10047       return decl;
10048     }
10049   else
10050     return expr;
10051 }
10052 \f
10053 /* Like c_begin_compound_stmt, except force the retention of the BLOCK.  */
10054
10055 tree
10056 c_begin_omp_parallel (void)
10057 {
10058   tree block;
10059
10060   keep_next_level ();
10061   block = c_begin_compound_stmt (true);
10062
10063   return block;
10064 }
10065
10066 /* Generate OMP_PARALLEL, with CLAUSES and BLOCK as its compound
10067    statement.  LOC is the location of the OMP_PARALLEL.  */
10068
10069 tree
10070 c_finish_omp_parallel (location_t loc, tree clauses, tree block)
10071 {
10072   tree stmt;
10073
10074   block = c_end_compound_stmt (loc, block, true);
10075
10076   stmt = make_node (OMP_PARALLEL);
10077   TREE_TYPE (stmt) = void_type_node;
10078   OMP_PARALLEL_CLAUSES (stmt) = clauses;
10079   OMP_PARALLEL_BODY (stmt) = block;
10080   SET_EXPR_LOCATION (stmt, loc);
10081
10082   return add_stmt (stmt);
10083 }
10084
10085 /* Like c_begin_compound_stmt, except force the retention of the BLOCK.  */
10086
10087 tree
10088 c_begin_omp_task (void)
10089 {
10090   tree block;
10091
10092   keep_next_level ();
10093   block = c_begin_compound_stmt (true);
10094
10095   return block;
10096 }
10097
10098 /* Generate OMP_TASK, with CLAUSES and BLOCK as its compound
10099    statement.  LOC is the location of the #pragma.  */
10100
10101 tree
10102 c_finish_omp_task (location_t loc, tree clauses, tree block)
10103 {
10104   tree stmt;
10105
10106   block = c_end_compound_stmt (loc, block, true);
10107
10108   stmt = make_node (OMP_TASK);
10109   TREE_TYPE (stmt) = void_type_node;
10110   OMP_TASK_CLAUSES (stmt) = clauses;
10111   OMP_TASK_BODY (stmt) = block;
10112   SET_EXPR_LOCATION (stmt, loc);
10113
10114   return add_stmt (stmt);
10115 }
10116
10117 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
10118    Remove any elements from the list that are invalid.  */
10119
10120 tree
10121 c_finish_omp_clauses (tree clauses)
10122 {
10123   bitmap_head generic_head, firstprivate_head, lastprivate_head;
10124   tree c, t, *pc = &clauses;
10125   const char *name;
10126
10127   bitmap_obstack_initialize (NULL);
10128   bitmap_initialize (&generic_head, &bitmap_default_obstack);
10129   bitmap_initialize (&firstprivate_head, &bitmap_default_obstack);
10130   bitmap_initialize (&lastprivate_head, &bitmap_default_obstack);
10131
10132   for (pc = &clauses, c = clauses; c ; c = *pc)
10133     {
10134       bool remove = false;
10135       bool need_complete = false;
10136       bool need_implicitly_determined = false;
10137
10138       switch (OMP_CLAUSE_CODE (c))
10139         {
10140         case OMP_CLAUSE_SHARED:
10141           name = "shared";
10142           need_implicitly_determined = true;
10143           goto check_dup_generic;
10144
10145         case OMP_CLAUSE_PRIVATE:
10146           name = "private";
10147           need_complete = true;
10148           need_implicitly_determined = true;
10149           goto check_dup_generic;
10150
10151         case OMP_CLAUSE_REDUCTION:
10152           name = "reduction";
10153           need_implicitly_determined = true;
10154           t = OMP_CLAUSE_DECL (c);
10155           if (AGGREGATE_TYPE_P (TREE_TYPE (t))
10156               || POINTER_TYPE_P (TREE_TYPE (t)))
10157             {
10158               error_at (OMP_CLAUSE_LOCATION (c),
10159                         "%qE has invalid type for %<reduction%>", t);
10160               remove = true;
10161             }
10162           else if (FLOAT_TYPE_P (TREE_TYPE (t)))
10163             {
10164               enum tree_code r_code = OMP_CLAUSE_REDUCTION_CODE (c);
10165               const char *r_name = NULL;
10166
10167               switch (r_code)
10168                 {
10169                 case PLUS_EXPR:
10170                 case MULT_EXPR:
10171                 case MINUS_EXPR:
10172                   break;
10173                 case BIT_AND_EXPR:
10174                   r_name = "&";
10175                   break;
10176                 case BIT_XOR_EXPR:
10177                   r_name = "^";
10178                   break;
10179                 case BIT_IOR_EXPR:
10180                   r_name = "|";
10181                   break;
10182                 case TRUTH_ANDIF_EXPR:
10183                   r_name = "&&";
10184                   break;
10185                 case TRUTH_ORIF_EXPR:
10186                   r_name = "||";
10187                   break;
10188                 default:
10189                   gcc_unreachable ();
10190                 }
10191               if (r_name)
10192                 {
10193                   error_at (OMP_CLAUSE_LOCATION (c),
10194                             "%qE has invalid type for %<reduction(%s)%>",
10195                             t, r_name);
10196                   remove = true;
10197                 }
10198             }
10199           goto check_dup_generic;
10200
10201         case OMP_CLAUSE_COPYPRIVATE:
10202           name = "copyprivate";
10203           goto check_dup_generic;
10204
10205         case OMP_CLAUSE_COPYIN:
10206           name = "copyin";
10207           t = OMP_CLAUSE_DECL (c);
10208           if (TREE_CODE (t) != VAR_DECL || !DECL_THREAD_LOCAL_P (t))
10209             {
10210               error_at (OMP_CLAUSE_LOCATION (c),
10211                         "%qE must be %<threadprivate%> for %<copyin%>", t);
10212               remove = true;
10213             }
10214           goto check_dup_generic;
10215
10216         check_dup_generic:
10217           t = OMP_CLAUSE_DECL (c);
10218           if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
10219             {
10220               error_at (OMP_CLAUSE_LOCATION (c),
10221                         "%qE is not a variable in clause %qs", t, name);
10222               remove = true;
10223             }
10224           else if (bitmap_bit_p (&generic_head, DECL_UID (t))
10225                    || bitmap_bit_p (&firstprivate_head, DECL_UID (t))
10226                    || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
10227             {
10228               error_at (OMP_CLAUSE_LOCATION (c),
10229                         "%qE appears more than once in data clauses", t);
10230               remove = true;
10231             }
10232           else
10233             bitmap_set_bit (&generic_head, DECL_UID (t));
10234           break;
10235
10236         case OMP_CLAUSE_FIRSTPRIVATE:
10237           name = "firstprivate";
10238           t = OMP_CLAUSE_DECL (c);
10239           need_complete = true;
10240           need_implicitly_determined = true;
10241           if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
10242             {
10243               error_at (OMP_CLAUSE_LOCATION (c),
10244                         "%qE is not a variable in clause %<firstprivate%>", t);
10245               remove = true;
10246             }
10247           else if (bitmap_bit_p (&generic_head, DECL_UID (t))
10248                    || bitmap_bit_p (&firstprivate_head, DECL_UID (t)))
10249             {
10250               error_at (OMP_CLAUSE_LOCATION (c),
10251                         "%qE appears more than once in data clauses", t);
10252               remove = true;
10253             }
10254           else
10255             bitmap_set_bit (&firstprivate_head, DECL_UID (t));
10256           break;
10257
10258         case OMP_CLAUSE_LASTPRIVATE:
10259           name = "lastprivate";
10260           t = OMP_CLAUSE_DECL (c);
10261           need_complete = true;
10262           need_implicitly_determined = true;
10263           if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
10264             {
10265               error_at (OMP_CLAUSE_LOCATION (c),
10266                         "%qE is not a variable in clause %<lastprivate%>", t);
10267               remove = true;
10268             }
10269           else if (bitmap_bit_p (&generic_head, DECL_UID (t))
10270                    || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
10271             {
10272               error_at (OMP_CLAUSE_LOCATION (c),
10273                      "%qE appears more than once in data clauses", t);
10274               remove = true;
10275             }
10276           else
10277             bitmap_set_bit (&lastprivate_head, DECL_UID (t));
10278           break;
10279
10280         case OMP_CLAUSE_IF:
10281         case OMP_CLAUSE_NUM_THREADS:
10282         case OMP_CLAUSE_SCHEDULE:
10283         case OMP_CLAUSE_NOWAIT:
10284         case OMP_CLAUSE_ORDERED:
10285         case OMP_CLAUSE_DEFAULT:
10286         case OMP_CLAUSE_UNTIED:
10287         case OMP_CLAUSE_COLLAPSE:
10288           pc = &OMP_CLAUSE_CHAIN (c);
10289           continue;
10290
10291         default:
10292           gcc_unreachable ();
10293         }
10294
10295       if (!remove)
10296         {
10297           t = OMP_CLAUSE_DECL (c);
10298
10299           if (need_complete)
10300             {
10301               t = require_complete_type (t);
10302               if (t == error_mark_node)
10303                 remove = true;
10304             }
10305
10306           if (need_implicitly_determined)
10307             {
10308               const char *share_name = NULL;
10309
10310               if (TREE_CODE (t) == VAR_DECL && DECL_THREAD_LOCAL_P (t))
10311                 share_name = "threadprivate";
10312               else switch (c_omp_predetermined_sharing (t))
10313                 {
10314                 case OMP_CLAUSE_DEFAULT_UNSPECIFIED:
10315                   break;
10316                 case OMP_CLAUSE_DEFAULT_SHARED:
10317                   share_name = "shared";
10318                   break;
10319                 case OMP_CLAUSE_DEFAULT_PRIVATE:
10320                   share_name = "private";
10321                   break;
10322                 default:
10323                   gcc_unreachable ();
10324                 }
10325               if (share_name)
10326                 {
10327                   error_at (OMP_CLAUSE_LOCATION (c),
10328                             "%qE is predetermined %qs for %qs",
10329                             t, share_name, name);
10330                   remove = true;
10331                 }
10332             }
10333         }
10334
10335       if (remove)
10336         *pc = OMP_CLAUSE_CHAIN (c);
10337       else
10338         pc = &OMP_CLAUSE_CHAIN (c);
10339     }
10340
10341   bitmap_obstack_release (NULL);
10342   return clauses;
10343 }
10344
10345 /* Make a variant type in the proper way for C/C++, propagating qualifiers
10346    down to the element type of an array.  */
10347
10348 tree
10349 c_build_qualified_type (tree type, int type_quals)
10350 {
10351   if (type == error_mark_node)
10352     return type;
10353
10354   if (TREE_CODE (type) == ARRAY_TYPE)
10355     {
10356       tree t;
10357       tree element_type = c_build_qualified_type (TREE_TYPE (type),
10358                                                   type_quals);
10359
10360       /* See if we already have an identically qualified type.  */
10361       for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
10362         {
10363           if (TYPE_QUALS (strip_array_types (t)) == type_quals
10364               && TYPE_NAME (t) == TYPE_NAME (type)
10365               && TYPE_CONTEXT (t) == TYPE_CONTEXT (type)
10366               && attribute_list_equal (TYPE_ATTRIBUTES (t),
10367                                        TYPE_ATTRIBUTES (type)))
10368             break;
10369         }
10370       if (!t)
10371         {
10372           tree domain = TYPE_DOMAIN (type);
10373
10374           t = build_variant_type_copy (type);
10375           TREE_TYPE (t) = element_type;
10376
10377           if (TYPE_STRUCTURAL_EQUALITY_P (element_type)
10378               || (domain && TYPE_STRUCTURAL_EQUALITY_P (domain)))
10379             SET_TYPE_STRUCTURAL_EQUALITY (t);
10380           else if (TYPE_CANONICAL (element_type) != element_type
10381                    || (domain && TYPE_CANONICAL (domain) != domain))
10382             {
10383               tree unqualified_canon
10384                 = build_array_type (TYPE_CANONICAL (element_type),
10385                                     domain? TYPE_CANONICAL (domain)
10386                                           : NULL_TREE);
10387               TYPE_CANONICAL (t)
10388                 = c_build_qualified_type (unqualified_canon, type_quals);
10389             }
10390           else
10391             TYPE_CANONICAL (t) = t;
10392         }
10393       return t;
10394     }
10395
10396   /* A restrict-qualified pointer type must be a pointer to object or
10397      incomplete type.  Note that the use of POINTER_TYPE_P also allows
10398      REFERENCE_TYPEs, which is appropriate for C++.  */
10399   if ((type_quals & TYPE_QUAL_RESTRICT)
10400       && (!POINTER_TYPE_P (type)
10401           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type))))
10402     {
10403       error ("invalid use of %<restrict%>");
10404       type_quals &= ~TYPE_QUAL_RESTRICT;
10405     }
10406
10407   return build_qualified_type (type, type_quals);
10408 }
10409
10410 /* Build a VA_ARG_EXPR for the C parser.  */
10411
10412 tree
10413 c_build_va_arg (location_t loc, tree expr, tree type)
10414 {
10415   if (warn_cxx_compat && TREE_CODE (type) == ENUMERAL_TYPE)
10416     warning_at (loc, OPT_Wc___compat,
10417                 "C++ requires promoted type, not enum type, in %<va_arg%>");
10418   return build_va_arg (loc, expr, type);
10419 }