gcc/cp/tree.c

   1 /* Language-dependent node constructors for parse phase of GNU compiler.
   2    Copyright (C) 1987-2016 Free Software Foundation, Inc.
   3    Hacked by Michael Tiemann (tiemann@cygnus.com)
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "tree.h"
  25 #include "cp-tree.h"
  26 #include "gimple-expr.h"
  27 #include "cgraph.h"
  28 #include "stor-layout.h"
  29 #include "print-tree.h"
  30 #include "tree-iterator.h"
  31 #include "tree-inline.h"
  32 #include "debug.h"
  33 #include "convert.h"
  34 #include "gimplify.h"
  35 #include "attribs.h"
  36
  37 static tree bot_manip (tree *, int *, void *);
  38 static tree bot_replace (tree *, int *, void *);
  39 static hashval_t list_hash_pieces (tree, tree, tree);
  40 static tree build_target_expr (tree, tree, tsubst_flags_t);
  41 static tree count_trees_r (tree *, int *, void *);
  42 static tree verify_stmt_tree_r (tree *, int *, void *);
  43 static tree build_local_temp (tree);
  44
  45 static tree handle_java_interface_attribute (tree *, tree, tree, int, bool *);
  46 static tree handle_com_interface_attribute (tree *, tree, tree, int, bool *);
  47 static tree handle_init_priority_attribute (tree *, tree, tree, int, bool *);
  48 static tree handle_abi_tag_attribute (tree *, tree, tree, int, bool *);
  49
  50 /* If REF is an lvalue, returns the kind of lvalue that REF is.
  51    Otherwise, returns clk_none.  */
  52
  53 cp_lvalue_kind
  54 lvalue_kind (const_tree ref)
  55 {
  56   cp_lvalue_kind op1_lvalue_kind = clk_none;
  57   cp_lvalue_kind op2_lvalue_kind = clk_none;
  58
  59   /* Expressions of reference type are sometimes wrapped in
  60      INDIRECT_REFs.  INDIRECT_REFs are just internal compiler
  61      representation, not part of the language, so we have to look
  62      through them.  */
  63   if (REFERENCE_REF_P (ref))
  64     return lvalue_kind (TREE_OPERAND (ref, 0));
  65
  66   if (TREE_TYPE (ref)
  67       && TREE_CODE (TREE_TYPE (ref)) == REFERENCE_TYPE)
  68     {
  69       /* unnamed rvalue references are rvalues */
  70       if (TYPE_REF_IS_RVALUE (TREE_TYPE (ref))
  71           && TREE_CODE (ref) != PARM_DECL
  72           && !VAR_P (ref)
  73           && TREE_CODE (ref) != COMPONENT_REF
  74           /* Functions are always lvalues.  */
  75           && TREE_CODE (TREE_TYPE (TREE_TYPE (ref))) != FUNCTION_TYPE)
  76         return clk_rvalueref;
  77
  78       /* lvalue references and named rvalue references are lvalues.  */
  79       return clk_ordinary;
  80     }
  81
  82   if (ref == current_class_ptr)
  83     return clk_none;
  84
  85   switch (TREE_CODE (ref))
  86     {
  87     case SAVE_EXPR:
  88       return clk_none;
  89       /* preincrements and predecrements are valid lvals, provided
  90          what they refer to are valid lvals.  */
  91     case PREINCREMENT_EXPR:
  92     case PREDECREMENT_EXPR:
  93     case TRY_CATCH_EXPR:
  94     case WITH_CLEANUP_EXPR:
  95     case REALPART_EXPR:
  96     case IMAGPART_EXPR:
  97       return lvalue_kind (TREE_OPERAND (ref, 0));
  98
  99     case MEMBER_REF:
 100     case DOTSTAR_EXPR:
 101       if (TREE_CODE (ref) == MEMBER_REF)
 102         op1_lvalue_kind = clk_ordinary;
 103       else
 104         op1_lvalue_kind = lvalue_kind (TREE_OPERAND (ref, 0));
 105       if (TYPE_PTRMEMFUNC_P (TREE_TYPE (TREE_OPERAND (ref, 1))))
 106         op1_lvalue_kind = clk_none;
 107       return op1_lvalue_kind;
 108
 109     case COMPONENT_REF:
 110       op1_lvalue_kind = lvalue_kind (TREE_OPERAND (ref, 0));
 111       /* Look at the member designator.  */
 112       if (!op1_lvalue_kind)
 113         ;
 114       else if (is_overloaded_fn (TREE_OPERAND (ref, 1)))
 115         /* The "field" can be a FUNCTION_DECL or an OVERLOAD in some
 116            situations.  If we're seeing a COMPONENT_REF, it's a non-static
 117            member, so it isn't an lvalue. */
 118         op1_lvalue_kind = clk_none;
 119       else if (TREE_CODE (TREE_OPERAND (ref, 1)) != FIELD_DECL)
 120         /* This can be IDENTIFIER_NODE in a template.  */;
 121       else if (DECL_C_BIT_FIELD (TREE_OPERAND (ref, 1)))
 122         {
 123           /* Clear the ordinary bit.  If this object was a class
 124              rvalue we want to preserve that information.  */
 125           op1_lvalue_kind &= ~clk_ordinary;
 126           /* The lvalue is for a bitfield.  */
 127           op1_lvalue_kind |= clk_bitfield;
 128         }
 129       else if (DECL_PACKED (TREE_OPERAND (ref, 1)))
 130         op1_lvalue_kind |= clk_packed;
 131
 132       return op1_lvalue_kind;
 133
 134     case STRING_CST:
 135     case COMPOUND_LITERAL_EXPR:
 136       return clk_ordinary;
 137
 138     case CONST_DECL:
 139       /* CONST_DECL without TREE_STATIC are enumeration values and
 140          thus not lvalues.  With TREE_STATIC they are used by ObjC++
 141          in objc_build_string_object and need to be considered as
 142          lvalues.  */
 143       if (! TREE_STATIC (ref))
 144         return clk_none;
 145     case VAR_DECL:
 146       if (TREE_READONLY (ref) && ! TREE_STATIC (ref)
 147           && DECL_LANG_SPECIFIC (ref)
 148           && DECL_IN_AGGR_P (ref))
 149         return clk_none;
 150     case INDIRECT_REF:
 151     case ARROW_EXPR:
 152     case ARRAY_REF:
 153     case ARRAY_NOTATION_REF:
 154     case PARM_DECL:
 155     case RESULT_DECL:
 156     case PLACEHOLDER_EXPR:
 157       return clk_ordinary;
 158
 159       /* A scope ref in a template, left as SCOPE_REF to support later
 160          access checking.  */
 161     case SCOPE_REF:
 162       gcc_assert (!type_dependent_expression_p (CONST_CAST_TREE (ref)));
 163       {
 164         tree op = TREE_OPERAND (ref, 1);
 165         if (TREE_CODE (op) == FIELD_DECL)
 166           return (DECL_C_BIT_FIELD (op) ? clk_bitfield : clk_ordinary);
 167         else
 168           return lvalue_kind (op);
 169       }
 170
 171     case MAX_EXPR:
 172     case MIN_EXPR:
 173       /* Disallow <? and >? as lvalues if either argument side-effects.  */
 174       if (TREE_SIDE_EFFECTS (TREE_OPERAND (ref, 0))
 175           || TREE_SIDE_EFFECTS (TREE_OPERAND (ref, 1)))
 176         return clk_none;
 177       op1_lvalue_kind = lvalue_kind (TREE_OPERAND (ref, 0));
 178       op2_lvalue_kind = lvalue_kind (TREE_OPERAND (ref, 1));
 179       break;
 180
 181     case COND_EXPR:
 182       op1_lvalue_kind = lvalue_kind (TREE_OPERAND (ref, 1)
 183                                     ? TREE_OPERAND (ref, 1)
 184                                     : TREE_OPERAND (ref, 0));
 185       op2_lvalue_kind = lvalue_kind (TREE_OPERAND (ref, 2));
 186       break;
 187
 188     case MODOP_EXPR:
 189       /* We expect to see unlowered MODOP_EXPRs only during
 190          template processing.  */
 191       gcc_assert (processing_template_decl);
 192       return clk_ordinary;
 193
 194     case MODIFY_EXPR:
 195     case TYPEID_EXPR:
 196       return clk_ordinary;
 197
 198     case COMPOUND_EXPR:
 199       return lvalue_kind (TREE_OPERAND (ref, 1));
 200
 201     case TARGET_EXPR:
 202       return clk_class;
 203
 204     case VA_ARG_EXPR:
 205       return (CLASS_TYPE_P (TREE_TYPE (ref)) ? clk_class : clk_none);
 206
 207     case CALL_EXPR:
 208       /* We can see calls outside of TARGET_EXPR in templates.  */
 209       if (CLASS_TYPE_P (TREE_TYPE (ref)))
 210         return clk_class;
 211       return clk_none;
 212
 213     case FUNCTION_DECL:
 214       /* All functions (except non-static-member functions) are
 215          lvalues.  */
 216       return (DECL_NONSTATIC_MEMBER_FUNCTION_P (ref)
 217               ? clk_none : clk_ordinary);
 218
 219     case BASELINK:
 220       /* We now represent a reference to a single static member function
 221          with a BASELINK.  */
 222       /* This CONST_CAST is okay because BASELINK_FUNCTIONS returns
 223          its argument unmodified and we assign it to a const_tree.  */
 224       return lvalue_kind (BASELINK_FUNCTIONS (CONST_CAST_TREE (ref)));
 225
 226     case NON_DEPENDENT_EXPR:
 227       return lvalue_kind (TREE_OPERAND (ref, 0));
 228
 229     default:
 230       if (!TREE_TYPE (ref))
 231         return clk_none;
 232       if (CLASS_TYPE_P (TREE_TYPE (ref)))
 233         return clk_class;
 234       break;
 235     }
 236
 237   /* If one operand is not an lvalue at all, then this expression is
 238      not an lvalue.  */
 239   if (!op1_lvalue_kind || !op2_lvalue_kind)
 240     return clk_none;
 241
 242   /* Otherwise, it's an lvalue, and it has all the odd properties
 243      contributed by either operand.  */
 244   op1_lvalue_kind = op1_lvalue_kind | op2_lvalue_kind;
 245   /* It's not an ordinary lvalue if it involves any other kind.  */
 246   if ((op1_lvalue_kind & ~clk_ordinary) != clk_none)
 247     op1_lvalue_kind &= ~clk_ordinary;
 248   /* It can't be both a pseudo-lvalue and a non-addressable lvalue.
 249      A COND_EXPR of those should be wrapped in a TARGET_EXPR.  */
 250   if ((op1_lvalue_kind & (clk_rvalueref|clk_class))
 251       && (op1_lvalue_kind & (clk_bitfield|clk_packed)))
 252     op1_lvalue_kind = clk_none;
 253   return op1_lvalue_kind;
 254 }
 255
 256 /* Returns the kind of lvalue that REF is, in the sense of
 257    [basic.lval].  This function should really be named lvalue_p; it
 258    computes the C++ definition of lvalue.  */
 259
 260 cp_lvalue_kind
 261 real_lvalue_p (const_tree ref)
 262 {
 263   cp_lvalue_kind kind = lvalue_kind (ref);
 264   if (kind & (clk_rvalueref|clk_class))
 265     return clk_none;
 266   else
 267     return kind;
 268 }
 269
 270 /* This differs from real_lvalue_p in that class rvalues are considered
 271    lvalues.  */
 272
 273 bool
 274 lvalue_p (const_tree ref)
 275 {
 276   return (lvalue_kind (ref) != clk_none);
 277 }
 278
 279 /* This differs from real_lvalue_p in that rvalues formed by dereferencing
 280    rvalue references are considered rvalues.  */
 281
 282 bool
 283 lvalue_or_rvalue_with_address_p (const_tree ref)
 284 {
 285   cp_lvalue_kind kind = lvalue_kind (ref);
 286   if (kind & clk_class)
 287     return false;
 288   else
 289     return (kind != clk_none);
 290 }
 291
 292 /* Returns true if REF is an xvalue, false otherwise.  */
 293
 294 bool
 295 xvalue_p (const_tree ref)
 296 {
 297   return (lvalue_kind (ref) == clk_rvalueref);
 298 }
 299
 300 /* Test whether DECL is a builtin that may appear in a
 301    constant-expression. */
 302
 303 bool
 304 builtin_valid_in_constant_expr_p (const_tree decl)
 305 {
 306   if (!(TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl)))
 307     /* Not a built-in.  */
 308     return false;
 309   switch (DECL_FUNCTION_CODE (decl))
 310     {
 311     case BUILT_IN_CONSTANT_P:
 312     case BUILT_IN_ATOMIC_ALWAYS_LOCK_FREE:
 313       /* These have constant results even if their operands are
 314          non-constant.  */
 315       return true;
 316     default:
 317       return false;
 318     }
 319 }
 320
 321 /* Build a TARGET_EXPR, initializing the DECL with the VALUE.  */
 322
 323 static tree
 324 build_target_expr (tree decl, tree value, tsubst_flags_t complain)
 325 {
 326   tree t;
 327   tree type = TREE_TYPE (decl);
 328
 329   gcc_checking_assert (VOID_TYPE_P (TREE_TYPE (value))
 330                        || TREE_TYPE (decl) == TREE_TYPE (value)
 331                        /* On ARM ctors return 'this'.  */
 332                        || (TYPE_PTR_P (TREE_TYPE (value))
 333                            && TREE_CODE (value) == CALL_EXPR)
 334                        || useless_type_conversion_p (TREE_TYPE (decl),
 335                                                      TREE_TYPE (value)));
 336
 337   t = cxx_maybe_build_cleanup (decl, complain);
 338   if (t == error_mark_node)
 339     return error_mark_node;
 340   t = build4 (TARGET_EXPR, type, decl, value, t, NULL_TREE);
 341   if (EXPR_HAS_LOCATION (value))
 342     SET_EXPR_LOCATION (t, EXPR_LOCATION (value));
 343   /* We always set TREE_SIDE_EFFECTS so that expand_expr does not
 344      ignore the TARGET_EXPR.  If there really turn out to be no
 345      side-effects, then the optimizer should be able to get rid of
 346      whatever code is generated anyhow.  */
 347   TREE_SIDE_EFFECTS (t) = 1;
 348
 349   return t;
 350 }
 351
 352 /* Return an undeclared local temporary of type TYPE for use in building a
 353    TARGET_EXPR.  */
 354
 355 static tree
 356 build_local_temp (tree type)
 357 {
 358   tree slot = build_decl (input_location,
 359                           VAR_DECL, NULL_TREE, type);
 360   DECL_ARTIFICIAL (slot) = 1;
 361   DECL_IGNORED_P (slot) = 1;
 362   DECL_CONTEXT (slot) = current_function_decl;
 363   layout_decl (slot, 0);
 364   return slot;
 365 }
 366
 367 /* Set various status flags when building an AGGR_INIT_EXPR object T.  */
 368
 369 static void
 370 process_aggr_init_operands (tree t)
 371 {
 372   bool side_effects;
 373
 374   side_effects = TREE_SIDE_EFFECTS (t);
 375   if (!side_effects)
 376     {
 377       int i, n;
 378       n = TREE_OPERAND_LENGTH (t);
 379       for (i = 1; i < n; i++)
 380         {
 381           tree op = TREE_OPERAND (t, i);
 382           if (op && TREE_SIDE_EFFECTS (op))
 383             {
 384               side_effects = 1;
 385               break;
 386             }
 387         }
 388     }
 389   TREE_SIDE_EFFECTS (t) = side_effects;
 390 }
 391
 392 /* Build an AGGR_INIT_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE,
 393    FN, and SLOT.  NARGS is the number of call arguments which are specified
 394    as a tree array ARGS.  */
 395
 396 static tree
 397 build_aggr_init_array (tree return_type, tree fn, tree slot, int nargs,
 398                        tree *args)
 399 {
 400   tree t;
 401   int i;
 402
 403   t = build_vl_exp (AGGR_INIT_EXPR, nargs + 3);
 404   TREE_TYPE (t) = return_type;
 405   AGGR_INIT_EXPR_FN (t) = fn;
 406   AGGR_INIT_EXPR_SLOT (t) = slot;
 407   for (i = 0; i < nargs; i++)
 408     AGGR_INIT_EXPR_ARG (t, i) = args[i];
 409   process_aggr_init_operands (t);
 410   return t;
 411 }
 412
 413 /* INIT is a CALL_EXPR or AGGR_INIT_EXPR which needs info about its
 414    target.  TYPE is the type to be initialized.
 415
 416    Build an AGGR_INIT_EXPR to represent the initialization.  This function
 417    differs from build_cplus_new in that an AGGR_INIT_EXPR can only be used
 418    to initialize another object, whereas a TARGET_EXPR can either
 419    initialize another object or create its own temporary object, and as a
 420    result building up a TARGET_EXPR requires that the type's destructor be
 421    callable.  */
 422
 423 tree
 424 build_aggr_init_expr (tree type, tree init)
 425 {
 426   tree fn;
 427   tree slot;
 428   tree rval;
 429   int is_ctor;
 430
 431   /* Don't build AGGR_INIT_EXPR in a template.  */
 432   if (processing_template_decl)
 433     return init;
 434
 435   if (TREE_CODE (init) == CALL_EXPR)
 436     fn = CALL_EXPR_FN (init);
 437   else if (TREE_CODE (init) == AGGR_INIT_EXPR)
 438     fn = AGGR_INIT_EXPR_FN (init);
 439   else
 440     return convert (type, init);
 441
 442   is_ctor = (TREE_CODE (fn) == ADDR_EXPR
 443              && TREE_CODE (TREE_OPERAND (fn, 0)) == FUNCTION_DECL
 444              && DECL_CONSTRUCTOR_P (TREE_OPERAND (fn, 0)));
 445
 446   /* We split the CALL_EXPR into its function and its arguments here.
 447      Then, in expand_expr, we put them back together.  The reason for
 448      this is that this expression might be a default argument
 449      expression.  In that case, we need a new temporary every time the
 450      expression is used.  That's what break_out_target_exprs does; it
 451      replaces every AGGR_INIT_EXPR with a copy that uses a fresh
 452      temporary slot.  Then, expand_expr builds up a call-expression
 453      using the new slot.  */
 454
 455   /* If we don't need to use a constructor to create an object of this
 456      type, don't mess with AGGR_INIT_EXPR.  */
 457   if (is_ctor || TREE_ADDRESSABLE (type))
 458     {
 459       slot = build_local_temp (type);
 460
 461       if (TREE_CODE (init) == CALL_EXPR)
 462         {
 463           rval = build_aggr_init_array (void_type_node, fn, slot,
 464                                         call_expr_nargs (init),
 465                                         CALL_EXPR_ARGP (init));
 466           AGGR_INIT_FROM_THUNK_P (rval)
 467             = CALL_FROM_THUNK_P (init);
 468         }
 469       else
 470         {
 471           rval = build_aggr_init_array (void_type_node, fn, slot,
 472                                         aggr_init_expr_nargs (init),
 473                                         AGGR_INIT_EXPR_ARGP (init));
 474           AGGR_INIT_FROM_THUNK_P (rval)
 475             = AGGR_INIT_FROM_THUNK_P (init);
 476         }
 477       TREE_SIDE_EFFECTS (rval) = 1;
 478       AGGR_INIT_VIA_CTOR_P (rval) = is_ctor;
 479       TREE_NOTHROW (rval) = TREE_NOTHROW (init);
 480       CALL_EXPR_LIST_INIT_P (rval) = CALL_EXPR_LIST_INIT_P (init);
 481     }
 482   else
 483     rval = init;
 484
 485   return rval;
 486 }
 487
 488 /* INIT is a CALL_EXPR or AGGR_INIT_EXPR which needs info about its
 489    target.  TYPE is the type that this initialization should appear to
 490    have.
 491
 492    Build an encapsulation of the initialization to perform
 493    and return it so that it can be processed by language-independent
 494    and language-specific expression expanders.  */
 495
 496 tree
 497 build_cplus_new (tree type, tree init, tsubst_flags_t complain)
 498 {
 499   tree rval = build_aggr_init_expr (type, init);
 500   tree slot;
 501
 502   if (!complete_type_or_maybe_complain (type, init, complain))
 503     return error_mark_node;
 504
 505   /* Make sure that we're not trying to create an instance of an
 506      abstract class.  */
 507   if (abstract_virtuals_error_sfinae (NULL_TREE, type, complain))
 508     return error_mark_node;
 509
 510   if (TREE_CODE (rval) == AGGR_INIT_EXPR)
 511     slot = AGGR_INIT_EXPR_SLOT (rval);
 512   else if (TREE_CODE (rval) == CALL_EXPR
 513            || TREE_CODE (rval) == CONSTRUCTOR)
 514     slot = build_local_temp (type);
 515   else
 516     return rval;
 517
 518   rval = build_target_expr (slot, rval, complain);
 519
 520   if (rval != error_mark_node)
 521     TARGET_EXPR_IMPLICIT_P (rval) = 1;
 522
 523   return rval;
 524 }
 525
 526 /* Subroutine of build_vec_init_expr: Build up a single element
 527    intialization as a proxy for the full array initialization to get things
 528    marked as used and any appropriate diagnostics.
 529
 530    Since we're deferring building the actual constructor calls until
 531    gimplification time, we need to build one now and throw it away so
 532    that the relevant constructor gets mark_used before cgraph decides
 533    what functions are needed.  Here we assume that init is either
 534    NULL_TREE, void_type_node (indicating value-initialization), or
 535    another array to copy.  */
 536
 537 static tree
 538 build_vec_init_elt (tree type, tree init, tsubst_flags_t complain)
 539 {
 540   tree inner_type = strip_array_types (type);
 541   vec<tree, va_gc> *argvec;
 542
 543   if (integer_zerop (array_type_nelts_total (type))
 544       || !CLASS_TYPE_P (inner_type))
 545     /* No interesting initialization to do.  */
 546     return integer_zero_node;
 547   else if (init == void_type_node)
 548     return build_value_init (inner_type, complain);
 549
 550   gcc_assert (init == NULL_TREE
 551               || (same_type_ignoring_top_level_qualifiers_p
 552                   (type, TREE_TYPE (init))));
 553
 554   argvec = make_tree_vector ();
 555   if (init)
 556     {
 557       tree init_type = strip_array_types (TREE_TYPE (init));
 558       tree dummy = build_dummy_object (init_type);
 559       if (!real_lvalue_p (init))
 560         dummy = move (dummy);
 561       argvec->quick_push (dummy);
 562     }
 563   init = build_special_member_call (NULL_TREE, complete_ctor_identifier,
 564                                     &argvec, inner_type, LOOKUP_NORMAL,
 565                                     complain);
 566   release_tree_vector (argvec);
 567
 568   /* For a trivial constructor, build_over_call creates a TARGET_EXPR.  But
 569      we don't want one here because we aren't creating a temporary.  */
 570   if (TREE_CODE (init) == TARGET_EXPR)
 571     init = TARGET_EXPR_INITIAL (init);
 572
 573   return init;
 574 }
 575
 576 /* Return a TARGET_EXPR which expresses the initialization of an array to
 577    be named later, either default-initialization or copy-initialization
 578    from another array of the same type.  */
 579
 580 tree
 581 build_vec_init_expr (tree type, tree init, tsubst_flags_t complain)
 582 {
 583   tree slot;
 584   bool value_init = false;
 585   tree elt_init = build_vec_init_elt (type, init, complain);
 586
 587   if (init == void_type_node)
 588     {
 589       value_init = true;
 590       init = NULL_TREE;
 591     }
 592
 593   slot = build_local_temp (type);
 594   init = build2 (VEC_INIT_EXPR, type, slot, init);
 595   TREE_SIDE_EFFECTS (init) = true;
 596   SET_EXPR_LOCATION (init, input_location);
 597
 598   if (cxx_dialect >= cxx11
 599       && potential_constant_expression (elt_init))
 600     VEC_INIT_EXPR_IS_CONSTEXPR (init) = true;
 601   VEC_INIT_EXPR_VALUE_INIT (init) = value_init;
 602
 603   return init;
 604 }
 605
 606 /* Give a helpful diagnostic for a non-constexpr VEC_INIT_EXPR in a context
 607    that requires a constant expression.  */
 608
 609 void
 610 diagnose_non_constexpr_vec_init (tree expr)
 611 {
 612   tree type = TREE_TYPE (VEC_INIT_EXPR_SLOT (expr));
 613   tree init, elt_init;
 614   if (VEC_INIT_EXPR_VALUE_INIT (expr))
 615     init = void_type_node;
 616   else
 617     init = VEC_INIT_EXPR_INIT (expr);
 618
 619   elt_init = build_vec_init_elt (type, init, tf_warning_or_error);
 620   require_potential_constant_expression (elt_init);
 621 }
 622
 623 tree
 624 build_array_copy (tree init)
 625 {
 626   return build_vec_init_expr (TREE_TYPE (init), init, tf_warning_or_error);
 627 }
 628
 629 /* Build a TARGET_EXPR using INIT to initialize a new temporary of the
 630    indicated TYPE.  */
 631
 632 tree
 633 build_target_expr_with_type (tree init, tree type, tsubst_flags_t complain)
 634 {
 635   gcc_assert (!VOID_TYPE_P (type));
 636
 637   if (TREE_CODE (init) == TARGET_EXPR
 638       || init == error_mark_node)
 639     return init;
 640   else if (CLASS_TYPE_P (type) && type_has_nontrivial_copy_init (type)
 641            && !VOID_TYPE_P (TREE_TYPE (init))
 642            && TREE_CODE (init) != COND_EXPR
 643            && TREE_CODE (init) != CONSTRUCTOR
 644            && TREE_CODE (init) != VA_ARG_EXPR)
 645     /* We need to build up a copy constructor call.  A void initializer
 646        means we're being called from bot_manip.  COND_EXPR is a special
 647        case because we already have copies on the arms and we don't want
 648        another one here.  A CONSTRUCTOR is aggregate initialization, which
 649        is handled separately.  A VA_ARG_EXPR is magic creation of an
 650        aggregate; there's no additional work to be done.  */
 651     return force_rvalue (init, complain);
 652
 653   return force_target_expr (type, init, complain);
 654 }
 655
 656 /* Like the above function, but without the checking.  This function should
 657    only be used by code which is deliberately trying to subvert the type
 658    system, such as call_builtin_trap.  Or build_over_call, to avoid
 659    infinite recursion.  */
 660
 661 tree
 662 force_target_expr (tree type, tree init, tsubst_flags_t complain)
 663 {
 664   tree slot;
 665
 666   gcc_assert (!VOID_TYPE_P (type));
 667
 668   slot = build_local_temp (type);
 669   return build_target_expr (slot, init, complain);
 670 }
 671
 672 /* Like build_target_expr_with_type, but use the type of INIT.  */
 673
 674 tree
 675 get_target_expr_sfinae (tree init, tsubst_flags_t complain)
 676 {
 677   if (TREE_CODE (init) == AGGR_INIT_EXPR)
 678     return build_target_expr (AGGR_INIT_EXPR_SLOT (init), init, complain);
 679   else if (TREE_CODE (init) == VEC_INIT_EXPR)
 680     return build_target_expr (VEC_INIT_EXPR_SLOT (init), init, complain);
 681   else
 682     return build_target_expr_with_type (init, TREE_TYPE (init), complain);
 683 }
 684
 685 tree
 686 get_target_expr (tree init)
 687 {
 688   return get_target_expr_sfinae (init, tf_warning_or_error);
 689 }
 690
 691 /* If EXPR is a bitfield reference, convert it to the declared type of
 692    the bitfield, and return the resulting expression.  Otherwise,
 693    return EXPR itself.  */
 694
 695 tree
 696 convert_bitfield_to_declared_type (tree expr)
 697 {
 698   tree bitfield_type;
 699
 700   bitfield_type = is_bitfield_expr_with_lowered_type (expr);
 701   if (bitfield_type)
 702     expr = convert_to_integer_nofold (TYPE_MAIN_VARIANT (bitfield_type),
 703                                       expr);
 704   return expr;
 705 }
 706
 707 /* EXPR is being used in an rvalue context.  Return a version of EXPR
 708    that is marked as an rvalue.  */
 709
 710 tree
 711 rvalue (tree expr)
 712 {
 713   tree type;
 714
 715   if (error_operand_p (expr))
 716     return expr;
 717
 718   expr = mark_rvalue_use (expr);
 719
 720   /* [basic.lval]
 721
 722      Non-class rvalues always have cv-unqualified types.  */
 723   type = TREE_TYPE (expr);
 724   if (!CLASS_TYPE_P (type) && cv_qualified_p (type))
 725     type = cv_unqualified (type);
 726
 727   /* We need to do this for rvalue refs as well to get the right answer
 728      from decltype; see c++/36628.  */
 729   if (!processing_template_decl && lvalue_or_rvalue_with_address_p (expr))
 730     expr = build1 (NON_LVALUE_EXPR, type, expr);
 731   else if (type != TREE_TYPE (expr))
 732     expr = build_nop (type, expr);
 733
 734   return expr;
 735 }
 736
 737 \f
 738 struct cplus_array_info
 739 {
 740   tree type;
 741   tree domain;
 742 };
 743
 744 struct cplus_array_hasher : ggc_ptr_hash<tree_node>
 745 {
 746   typedef cplus_array_info *compare_type;
 747
 748   static hashval_t hash (tree t);
 749   static bool equal (tree, cplus_array_info *);
 750 };
 751
 752 /* Hash an ARRAY_TYPE.  K is really of type `tree'.  */
 753
 754 hashval_t
 755 cplus_array_hasher::hash (tree t)
 756 {
 757   hashval_t hash;
 758
 759   hash = TYPE_UID (TREE_TYPE (t));
 760   if (TYPE_DOMAIN (t))
 761     hash ^= TYPE_UID (TYPE_DOMAIN (t));
 762   return hash;
 763 }
 764
 765 /* Compare two ARRAY_TYPEs.  K1 is really of type `tree', K2 is really
 766    of type `cplus_array_info*'. */
 767
 768 bool
 769 cplus_array_hasher::equal (tree t1, cplus_array_info *t2)
 770 {
 771   return (TREE_TYPE (t1) == t2->type && TYPE_DOMAIN (t1) == t2->domain);
 772 }
 773
 774 /* Hash table containing dependent array types, which are unsuitable for
 775    the language-independent type hash table.  */
 776 static GTY (()) hash_table<cplus_array_hasher> *cplus_array_htab;
 777
 778 /* Build an ARRAY_TYPE without laying it out.  */
 779
 780 static tree
 781 build_min_array_type (tree elt_type, tree index_type)
 782 {
 783   tree t = cxx_make_type (ARRAY_TYPE);
 784   TREE_TYPE (t) = elt_type;
 785   TYPE_DOMAIN (t) = index_type;
 786   return t;
 787 }
 788
 789 /* Set TYPE_CANONICAL like build_array_type_1, but using
 790    build_cplus_array_type.  */
 791
 792 static void
 793 set_array_type_canon (tree t, tree elt_type, tree index_type)
 794 {
 795   /* Set the canonical type for this new node.  */
 796   if (TYPE_STRUCTURAL_EQUALITY_P (elt_type)
 797       || (index_type && TYPE_STRUCTURAL_EQUALITY_P (index_type)))
 798     SET_TYPE_STRUCTURAL_EQUALITY (t);
 799   else if (TYPE_CANONICAL (elt_type) != elt_type
 800            || (index_type && TYPE_CANONICAL (index_type) != index_type))
 801     TYPE_CANONICAL (t)
 802       = build_cplus_array_type (TYPE_CANONICAL (elt_type),
 803                                 index_type
 804                                 ? TYPE_CANONICAL (index_type) : index_type);
 805   else
 806     TYPE_CANONICAL (t) = t;
 807 }
 808
 809 /* Like build_array_type, but handle special C++ semantics: an array of a
 810    variant element type is a variant of the array of the main variant of
 811    the element type.  */
 812
 813 tree
 814 build_cplus_array_type (tree elt_type, tree index_type)
 815 {
 816   tree t;
 817
 818   if (elt_type == error_mark_node || index_type == error_mark_node)
 819     return error_mark_node;
 820
 821   bool dependent = (uses_template_parms (elt_type)
 822                     || (index_type && uses_template_parms (index_type)));
 823
 824   if (elt_type != TYPE_MAIN_VARIANT (elt_type))
 825     /* Start with an array of the TYPE_MAIN_VARIANT.  */
 826     t = build_cplus_array_type (TYPE_MAIN_VARIANT (elt_type),
 827                                 index_type);
 828   else if (dependent)
 829     {
 830       /* Since type_hash_canon calls layout_type, we need to use our own
 831          hash table.  */
 832       cplus_array_info cai;
 833       hashval_t hash;
 834
 835       if (cplus_array_htab == NULL)
 836         cplus_array_htab = hash_table<cplus_array_hasher>::create_ggc (61);
 837
 838       hash = TYPE_UID (elt_type);
 839       if (index_type)
 840         hash ^= TYPE_UID (index_type);
 841       cai.type = elt_type;
 842       cai.domain = index_type;
 843
 844       tree *e = cplus_array_htab->find_slot_with_hash (&cai, hash, INSERT);
 845       if (*e)
 846         /* We have found the type: we're done.  */
 847         return (tree) *e;
 848       else
 849         {
 850           /* Build a new array type.  */
 851           t = build_min_array_type (elt_type, index_type);
 852
 853           /* Store it in the hash table. */
 854           *e = t;
 855
 856           /* Set the canonical type for this new node.  */
 857           set_array_type_canon (t, elt_type, index_type);
 858         }
 859     }
 860   else
 861     {
 862       t = build_array_type (elt_type, index_type);
 863     }
 864
 865   /* Now check whether we already have this array variant.  */
 866   if (elt_type != TYPE_MAIN_VARIANT (elt_type))
 867     {
 868       tree m = t;
 869       for (t = m; t; t = TYPE_NEXT_VARIANT (t))
 870         if (TREE_TYPE (t) == elt_type
 871             && TYPE_NAME (t) == NULL_TREE
 872             && TYPE_ATTRIBUTES (t) == NULL_TREE)
 873           break;
 874       if (!t)
 875         {
 876           t = build_min_array_type (elt_type, index_type);
 877           set_array_type_canon (t, elt_type, index_type);
 878           if (!dependent)
 879             {
 880               layout_type (t);
 881               /* Make sure sizes are shared with the main variant.
 882                  layout_type can't be called after setting TYPE_NEXT_VARIANT,
 883                  as it will overwrite alignment etc. of all variants.  */
 884               TYPE_SIZE (t) = TYPE_SIZE (m);
 885               TYPE_SIZE_UNIT (t) = TYPE_SIZE_UNIT (m);
 886             }
 887
 888           TYPE_MAIN_VARIANT (t) = m;
 889           TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
 890           TYPE_NEXT_VARIANT (m) = t;
 891         }
 892     }
 893
 894   /* Avoid spurious warnings with VLAs (c++/54583).  */
 895   if (TYPE_SIZE (t) && EXPR_P (TYPE_SIZE (t)))
 896     TREE_NO_WARNING (TYPE_SIZE (t)) = 1;
 897
 898   /* Push these needs up to the ARRAY_TYPE so that initialization takes
 899      place more easily.  */
 900   bool needs_ctor = (TYPE_NEEDS_CONSTRUCTING (t)
 901                      = TYPE_NEEDS_CONSTRUCTING (elt_type));
 902   bool needs_dtor = (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
 903                      = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (elt_type));
 904
 905   if (!dependent && t == TYPE_MAIN_VARIANT (t)
 906       && !COMPLETE_TYPE_P (t) && COMPLETE_TYPE_P (elt_type))
 907     {
 908       /* The element type has been completed since the last time we saw
 909          this array type; update the layout and 'tor flags for any variants
 910          that need it.  */
 911       layout_type (t);
 912       for (tree v = TYPE_NEXT_VARIANT (t); v; v = TYPE_NEXT_VARIANT (v))
 913         {
 914           TYPE_NEEDS_CONSTRUCTING (v) = needs_ctor;
 915           TYPE_HAS_NONTRIVIAL_DESTRUCTOR (v) = needs_dtor;
 916         }
 917     }
 918
 919   return t;
 920 }
 921
 922 /* Return an ARRAY_TYPE with element type ELT and length N.  */
 923
 924 tree
 925 build_array_of_n_type (tree elt, int n)
 926 {
 927   return build_cplus_array_type (elt, build_index_type (size_int (n - 1)));
 928 }
 929
 930 /* True iff T is an N3639 array of runtime bound (VLA).  These were
 931    approved for C++14 but then removed.  */
 932
 933 bool
 934 array_of_runtime_bound_p (tree t)
 935 {
 936   if (!t || TREE_CODE (t) != ARRAY_TYPE)
 937     return false;
 938   tree dom = TYPE_DOMAIN (t);
 939   if (!dom)
 940     return false;
 941   tree max = TYPE_MAX_VALUE (dom);
 942   return (!potential_rvalue_constant_expression (max)
 943           || (!value_dependent_expression_p (max) && !TREE_CONSTANT (max)));
 944 }
 945
 946 /* Return a reference type node referring to TO_TYPE.  If RVAL is
 947    true, return an rvalue reference type, otherwise return an lvalue
 948    reference type.  If a type node exists, reuse it, otherwise create
 949    a new one.  */
 950 tree
 951 cp_build_reference_type (tree to_type, bool rval)
 952 {
 953   tree lvalue_ref, t;
 954   lvalue_ref = build_reference_type (to_type);
 955   if (!rval)
 956     return lvalue_ref;
 957
 958   /* This code to create rvalue reference types is based on and tied
 959      to the code creating lvalue reference types in the middle-end
 960      functions build_reference_type_for_mode and build_reference_type.
 961
 962      It works by putting the rvalue reference type nodes after the
 963      lvalue reference nodes in the TYPE_NEXT_REF_TO linked list, so
 964      they will effectively be ignored by the middle end.  */
 965
 966   for (t = lvalue_ref; (t = TYPE_NEXT_REF_TO (t)); )
 967     if (TYPE_REF_IS_RVALUE (t))
 968       return t;
 969
 970   t = build_distinct_type_copy (lvalue_ref);
 971
 972   TYPE_REF_IS_RVALUE (t) = true;
 973   TYPE_NEXT_REF_TO (t) = TYPE_NEXT_REF_TO (lvalue_ref);
 974   TYPE_NEXT_REF_TO (lvalue_ref) = t;
 975
 976   if (TYPE_STRUCTURAL_EQUALITY_P (to_type))
 977     SET_TYPE_STRUCTURAL_EQUALITY (t);
 978   else if (TYPE_CANONICAL (to_type) != to_type)
 979     TYPE_CANONICAL (t)
 980       = cp_build_reference_type (TYPE_CANONICAL (to_type), rval);
 981   else
 982     TYPE_CANONICAL (t) = t;
 983
 984   layout_type (t);
 985
 986   return t;
 987
 988 }
 989
 990 /* Returns EXPR cast to rvalue reference type, like std::move.  */
 991
 992 tree
 993 move (tree expr)
 994 {
 995   tree type = TREE_TYPE (expr);
 996   gcc_assert (TREE_CODE (type) != REFERENCE_TYPE);
 997   type = cp_build_reference_type (type, /*rval*/true);
 998   return build_static_cast (type, expr, tf_warning_or_error);
 999 }
1000
1001 /* Used by the C++ front end to build qualified array types.  However,
1002    the C version of this function does not properly maintain canonical
1003    types (which are not used in C).  */
1004 tree
1005 c_build_qualified_type (tree type, int type_quals, tree /* orig_qual_type */,
1006                         size_t /* orig_qual_indirect */)
1007 {
1008   return cp_build_qualified_type (type, type_quals);
1009 }
1010
1011 \f
1012 /* Make a variant of TYPE, qualified with the TYPE_QUALS.  Handles
1013    arrays correctly.  In particular, if TYPE is an array of T's, and
1014    TYPE_QUALS is non-empty, returns an array of qualified T's.
1015
1016    FLAGS determines how to deal with ill-formed qualifications. If
1017    tf_ignore_bad_quals is set, then bad qualifications are dropped
1018    (this is permitted if TYPE was introduced via a typedef or template
1019    type parameter). If bad qualifications are dropped and tf_warning
1020    is set, then a warning is issued for non-const qualifications.  If
1021    tf_ignore_bad_quals is not set and tf_error is not set, we
1022    return error_mark_node. Otherwise, we issue an error, and ignore
1023    the qualifications.
1024
1025    Qualification of a reference type is valid when the reference came
1026    via a typedef or template type argument. [dcl.ref] No such
1027    dispensation is provided for qualifying a function type.  [dcl.fct]
1028    DR 295 queries this and the proposed resolution brings it into line
1029    with qualifying a reference.  We implement the DR.  We also behave
1030    in a similar manner for restricting non-pointer types.  */
1031
1032 tree
1033 cp_build_qualified_type_real (tree type,
1034                               int type_quals,
1035                               tsubst_flags_t complain)
1036 {
1037   tree result;
1038   int bad_quals = TYPE_UNQUALIFIED;
1039
1040   if (type == error_mark_node)
1041     return type;
1042
1043   if (type_quals == cp_type_quals (type))
1044     return type;
1045
1046   if (TREE_CODE (type) == ARRAY_TYPE)
1047     {
1048       /* In C++, the qualification really applies to the array element
1049          type.  Obtain the appropriately qualified element type.  */
1050       tree t;
1051       tree element_type
1052         = cp_build_qualified_type_real (TREE_TYPE (type),
1053                                         type_quals,
1054                                         complain);
1055
1056       if (element_type == error_mark_node)
1057         return error_mark_node;
1058
1059       /* See if we already have an identically qualified type.  Tests
1060          should be equivalent to those in check_qualified_type.  */
1061       for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
1062         if (TREE_TYPE (t) == element_type
1063             && TYPE_NAME (t) == TYPE_NAME (type)
1064             && TYPE_CONTEXT (t) == TYPE_CONTEXT (type)
1065             && attribute_list_equal (TYPE_ATTRIBUTES (t),
1066                                      TYPE_ATTRIBUTES (type)))
1067           break;
1068
1069       if (!t)
1070         {
1071           t = build_cplus_array_type (element_type, TYPE_DOMAIN (type));
1072
1073           /* Keep the typedef name.  */
1074           if (TYPE_NAME (t) != TYPE_NAME (type))
1075             {
1076               t = build_variant_type_copy (t);
1077               TYPE_NAME (t) = TYPE_NAME (type);
1078               TYPE_ALIGN (t) = TYPE_ALIGN (type);
1079               TYPE_USER_ALIGN (t) = TYPE_USER_ALIGN (type);
1080             }
1081         }
1082
1083       /* Even if we already had this variant, we update
1084          TYPE_NEEDS_CONSTRUCTING and TYPE_HAS_NONTRIVIAL_DESTRUCTOR in case
1085          they changed since the variant was originally created.
1086
1087          This seems hokey; if there is some way to use a previous
1088          variant *without* coming through here,
1089          TYPE_NEEDS_CONSTRUCTING will never be updated.  */
1090       TYPE_NEEDS_CONSTRUCTING (t)
1091         = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (element_type));
1092       TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
1093         = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (element_type));
1094       return t;
1095     }
1096   else if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
1097     {
1098       tree t = PACK_EXPANSION_PATTERN (type);
1099
1100       t = cp_build_qualified_type_real (t, type_quals, complain);
1101       return make_pack_expansion (t);
1102     }
1103
1104   /* A reference or method type shall not be cv-qualified.
1105      [dcl.ref], [dcl.fct].  This used to be an error, but as of DR 295
1106      (in CD1) we always ignore extra cv-quals on functions.  */
1107   if (type_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)
1108       && (TREE_CODE (type) == REFERENCE_TYPE
1109           || TREE_CODE (type) == FUNCTION_TYPE
1110           || TREE_CODE (type) == METHOD_TYPE))
1111     {
1112       if (TREE_CODE (type) == REFERENCE_TYPE)
1113         bad_quals |= type_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE);
1114       type_quals &= ~(TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE);
1115     }
1116
1117   /* But preserve any function-cv-quals on a FUNCTION_TYPE.  */
1118   if (TREE_CODE (type) == FUNCTION_TYPE)
1119     type_quals |= type_memfn_quals (type);
1120
1121   /* A restrict-qualified type must be a pointer (or reference)
1122      to object or incomplete type. */
1123   if ((type_quals & TYPE_QUAL_RESTRICT)
1124       && TREE_CODE (type) != TEMPLATE_TYPE_PARM
1125       && TREE_CODE (type) != TYPENAME_TYPE
1126       && !POINTER_TYPE_P (type))
1127     {
1128       bad_quals |= TYPE_QUAL_RESTRICT;
1129       type_quals &= ~TYPE_QUAL_RESTRICT;
1130     }
1131
1132   if (bad_quals == TYPE_UNQUALIFIED
1133       || (complain & tf_ignore_bad_quals))
1134     /*OK*/;
1135   else if (!(complain & tf_error))
1136     return error_mark_node;
1137   else
1138     {
1139       tree bad_type = build_qualified_type (ptr_type_node, bad_quals);
1140       error ("%qV qualifiers cannot be applied to %qT",
1141              bad_type, type);
1142     }
1143
1144   /* Retrieve (or create) the appropriately qualified variant.  */
1145   result = build_qualified_type (type, type_quals);
1146
1147   /* Preserve exception specs and ref-qualifier since build_qualified_type
1148      doesn't know about them.  */
1149   if (TREE_CODE (result) == FUNCTION_TYPE
1150       || TREE_CODE (result) == METHOD_TYPE)
1151     {
1152       result = build_exception_variant (result, TYPE_RAISES_EXCEPTIONS (type));
1153       result = build_ref_qualified_type (result, type_memfn_rqual (type));
1154     }
1155
1156   return result;
1157 }
1158
1159 /* Return TYPE with const and volatile removed.  */
1160
1161 tree
1162 cv_unqualified (tree type)
1163 {
1164   int quals;
1165
1166   if (type == error_mark_node)
1167     return type;
1168
1169   quals = cp_type_quals (type);
1170   quals &= ~(TYPE_QUAL_CONST|TYPE_QUAL_VOLATILE);
1171   return cp_build_qualified_type (type, quals);
1172 }
1173
1174 /* Subroutine of strip_typedefs.  We want to apply to RESULT the attributes
1175    from ATTRIBS that affect type identity, and no others.  If any are not
1176    applied, set *remove_attributes to true.  */
1177
1178 static tree
1179 apply_identity_attributes (tree result, tree attribs, bool *remove_attributes)
1180 {
1181   tree first_ident = NULL_TREE;
1182   tree new_attribs = NULL_TREE;
1183   tree *p = &new_attribs;
1184
1185   if (OVERLOAD_TYPE_P (result))
1186     {
1187       /* On classes and enums all attributes are ingrained.  */
1188       gcc_assert (attribs == TYPE_ATTRIBUTES (result));
1189       return result;
1190     }
1191
1192   for (tree a = attribs; a; a = TREE_CHAIN (a))
1193     {
1194       const attribute_spec *as
1195         = lookup_attribute_spec (get_attribute_name (a));
1196       if (as && as->affects_type_identity)
1197         {
1198           if (!first_ident)
1199             first_ident = a;
1200           else if (first_ident == error_mark_node)
1201             {
1202               *p = tree_cons (TREE_PURPOSE (a), TREE_VALUE (a), NULL_TREE);
1203               p = &TREE_CHAIN (*p);
1204             }
1205         }
1206       else if (first_ident)
1207         {
1208           for (tree a2 = first_ident; a2; a2 = TREE_CHAIN (a2))
1209             {
1210               *p = tree_cons (TREE_PURPOSE (a2), TREE_VALUE (a2), NULL_TREE);
1211               p = &TREE_CHAIN (*p);
1212             }
1213           first_ident = error_mark_node;
1214         }
1215     }
1216   if (first_ident != error_mark_node)
1217     new_attribs = first_ident;
1218
1219   if (first_ident == attribs)
1220     /* All attributes affected type identity.  */;
1221   else
1222     *remove_attributes = true;
1223
1224   return cp_build_type_attribute_variant (result, new_attribs);
1225 }
1226
1227 /* Builds a qualified variant of T that is not a typedef variant.
1228    E.g. consider the following declarations:
1229      typedef const int ConstInt;
1230      typedef ConstInt* PtrConstInt;
1231    If T is PtrConstInt, this function returns a type representing
1232      const int*.
1233    In other words, if T is a typedef, the function returns the underlying type.
1234    The cv-qualification and attributes of the type returned match the
1235    input type.
1236    They will always be compatible types.
1237    The returned type is built so that all of its subtypes
1238    recursively have their typedefs stripped as well.
1239
1240    This is different from just returning TYPE_CANONICAL (T)
1241    Because of several reasons:
1242     * If T is a type that needs structural equality
1243       its TYPE_CANONICAL (T) will be NULL.
1244     * TYPE_CANONICAL (T) desn't carry type attributes
1245       and loses template parameter names.
1246
1247    If REMOVE_ATTRIBUTES is non-null, also strip attributes that don't
1248    affect type identity, and set the referent to true if any were
1249    stripped.  */
1250
1251 tree
1252 strip_typedefs (tree t, bool *remove_attributes)
1253 {
1254   tree result = NULL, type = NULL, t0 = NULL;
1255
1256   if (!t || t == error_mark_node)
1257     return t;
1258
1259   if (TREE_CODE (t) == TREE_LIST)
1260     {
1261       bool changed = false;
1262       vec<tree,va_gc> *vec = make_tree_vector ();
1263       tree r = t;
1264       for (; t; t = TREE_CHAIN (t))
1265         {
1266           gcc_assert (!TREE_PURPOSE (t));
1267           tree elt = strip_typedefs (TREE_VALUE (t), remove_attributes);
1268           if (elt != TREE_VALUE (t))
1269             changed = true;
1270           vec_safe_push (vec, elt);
1271         }
1272       if (changed)
1273         r = build_tree_list_vec (vec);
1274       release_tree_vector (vec);
1275       return r;
1276     }
1277
1278   gcc_assert (TYPE_P (t));
1279
1280   if (t == TYPE_CANONICAL (t))
1281     return t;
1282
1283   if (dependent_alias_template_spec_p (t))
1284     /* DR 1558: However, if the template-id is dependent, subsequent
1285        template argument substitution still applies to the template-id.  */
1286     return t;
1287
1288   switch (TREE_CODE (t))
1289     {
1290     case POINTER_TYPE:
1291       type = strip_typedefs (TREE_TYPE (t), remove_attributes);
1292       result = build_pointer_type (type);
1293       break;
1294     case REFERENCE_TYPE:
1295       type = strip_typedefs (TREE_TYPE (t), remove_attributes);
1296       result = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
1297       break;
1298     case OFFSET_TYPE:
1299       t0 = strip_typedefs (TYPE_OFFSET_BASETYPE (t), remove_attributes);
1300       type = strip_typedefs (TREE_TYPE (t), remove_attributes);
1301       result = build_offset_type (t0, type);
1302       break;
1303     case RECORD_TYPE:
1304       if (TYPE_PTRMEMFUNC_P (t))
1305         {
1306           t0 = strip_typedefs (TYPE_PTRMEMFUNC_FN_TYPE (t), remove_attributes);
1307           result = build_ptrmemfunc_type (t0);
1308         }
1309       break;
1310     case ARRAY_TYPE:
1311       type = strip_typedefs (TREE_TYPE (t), remove_attributes);
1312       t0  = strip_typedefs (TYPE_DOMAIN (t), remove_attributes);
1313       result = build_cplus_array_type (type, t0);
1314       break;
1315     case FUNCTION_TYPE:
1316     case METHOD_TYPE:
1317       {
1318         tree arg_types = NULL, arg_node, arg_node2, arg_type;
1319         bool changed;
1320
1321         /* Because we stomp on TREE_PURPOSE of TYPE_ARG_TYPES in many places
1322            around the compiler (e.g. cp_parser_late_parsing_default_args), we
1323            can't expect that re-hashing a function type will find a previous
1324            equivalent type, so try to reuse the input type if nothing has
1325            changed.  If the type is itself a variant, that will change.  */
1326         bool is_variant = typedef_variant_p (t);
1327         if (remove_attributes
1328             && (TYPE_ATTRIBUTES (t) || TYPE_USER_ALIGN (t)))
1329           is_variant = true;
1330
1331         type = strip_typedefs (TREE_TYPE (t), remove_attributes);
1332         changed = type != TREE_TYPE (t) || is_variant;
1333
1334         for (arg_node = TYPE_ARG_TYPES (t);
1335              arg_node;
1336              arg_node = TREE_CHAIN (arg_node))
1337           {
1338             if (arg_node == void_list_node)
1339               break;
1340             arg_type = strip_typedefs (TREE_VALUE (arg_node),
1341                                        remove_attributes);
1342             gcc_assert (arg_type);
1343             if (arg_type == TREE_VALUE (arg_node) && !changed)
1344               continue;
1345
1346             if (!changed)
1347               {
1348                 changed = true;
1349                 for (arg_node2 = TYPE_ARG_TYPES (t);
1350                      arg_node2 != arg_node;
1351                      arg_node2 = TREE_CHAIN (arg_node2))
1352                   arg_types
1353                     = tree_cons (TREE_PURPOSE (arg_node2),
1354                                  TREE_VALUE (arg_node2), arg_types);
1355               }
1356
1357             arg_types
1358               = tree_cons (TREE_PURPOSE (arg_node), arg_type, arg_types);
1359           }
1360
1361         if (!changed)
1362           return t;
1363
1364         if (arg_types)
1365           arg_types = nreverse (arg_types);
1366
1367         /* A list of parameters not ending with an ellipsis
1368            must end with void_list_node.  */
1369         if (arg_node)
1370           arg_types = chainon (arg_types, void_list_node);
1371
1372         if (TREE_CODE (t) == METHOD_TYPE)
1373           {
1374             tree class_type = TREE_TYPE (TREE_VALUE (arg_types));
1375             gcc_assert (class_type);
1376             result =
1377               build_method_type_directly (class_type, type,
1378                                           TREE_CHAIN (arg_types));
1379             result
1380               = build_ref_qualified_type (result, type_memfn_rqual (t));
1381           }
1382         else
1383           {
1384             result = build_function_type (type,
1385                                           arg_types);
1386             result = apply_memfn_quals (result,
1387                                         type_memfn_quals (t),
1388                                         type_memfn_rqual (t));
1389           }
1390
1391         if (TYPE_RAISES_EXCEPTIONS (t))
1392           result = build_exception_variant (result,
1393                                             TYPE_RAISES_EXCEPTIONS (t));
1394         if (TYPE_HAS_LATE_RETURN_TYPE (t))
1395           TYPE_HAS_LATE_RETURN_TYPE (result) = 1;
1396       }
1397       break;
1398     case TYPENAME_TYPE:
1399       {
1400         tree fullname = TYPENAME_TYPE_FULLNAME (t);
1401         if (TREE_CODE (fullname) == TEMPLATE_ID_EXPR
1402             && TREE_OPERAND (fullname, 1))
1403           {
1404             tree args = TREE_OPERAND (fullname, 1);
1405             tree new_args = copy_node (args);
1406             bool changed = false;
1407             for (int i = 0; i < TREE_VEC_LENGTH (args); ++i)
1408               {
1409                 tree arg = TREE_VEC_ELT (args, i);
1410                 tree strip_arg;
1411                 if (TYPE_P (arg))
1412                   strip_arg = strip_typedefs (arg, remove_attributes);
1413                 else
1414                   strip_arg = strip_typedefs_expr (arg, remove_attributes);
1415                 TREE_VEC_ELT (new_args, i) = strip_arg;
1416                 if (strip_arg != arg)
1417                   changed = true;
1418               }
1419             if (changed)
1420               {
1421                 NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_args)
1422                   = NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
1423                 fullname
1424                   = lookup_template_function (TREE_OPERAND (fullname, 0),
1425                                               new_args);
1426               }
1427             else
1428               ggc_free (new_args);
1429           }
1430         result = make_typename_type (strip_typedefs (TYPE_CONTEXT (t),
1431                                                      remove_attributes),
1432                                      fullname, typename_type, tf_none);
1433         /* Handle 'typedef typename A::N N;'  */
1434         if (typedef_variant_p (result))
1435           result = TYPE_MAIN_VARIANT (DECL_ORIGINAL_TYPE (TYPE_NAME (result)));
1436       }
1437       break;
1438     case DECLTYPE_TYPE:
1439       result = strip_typedefs_expr (DECLTYPE_TYPE_EXPR (t),
1440                                     remove_attributes);
1441       if (result == DECLTYPE_TYPE_EXPR (t))
1442         result = NULL_TREE;
1443       else
1444         result = (finish_decltype_type
1445                   (result,
1446                    DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t),
1447                    tf_none));
1448       break;
1449     default:
1450       break;
1451     }
1452
1453   if (!result)
1454     {
1455       if (typedef_variant_p (t))
1456         {
1457           /* Explicitly get the underlying type, as TYPE_MAIN_VARIANT doesn't
1458              strip typedefs with attributes.  */
1459           result = TYPE_MAIN_VARIANT (DECL_ORIGINAL_TYPE (TYPE_NAME (t)));
1460           result = strip_typedefs (result);
1461         }
1462       else
1463         result = TYPE_MAIN_VARIANT (t);
1464     }
1465   gcc_assert (!typedef_variant_p (result));
1466   if (TYPE_USER_ALIGN (t) != TYPE_USER_ALIGN (result)
1467       || TYPE_ALIGN (t) != TYPE_ALIGN (result))
1468     {
1469       gcc_assert (TYPE_USER_ALIGN (t));
1470       if (remove_attributes)
1471         *remove_attributes = true;
1472       else
1473         {
1474           if (TYPE_ALIGN (t) == TYPE_ALIGN (result))
1475             result = build_variant_type_copy (result);
1476           else
1477             result = build_aligned_type (result, TYPE_ALIGN (t));
1478           TYPE_USER_ALIGN (result) = true;
1479         }
1480     }
1481   if (TYPE_ATTRIBUTES (t))
1482     {
1483       if (remove_attributes)
1484         result = apply_identity_attributes (result, TYPE_ATTRIBUTES (t),
1485                                             remove_attributes);
1486       else
1487         result = cp_build_type_attribute_variant (result, TYPE_ATTRIBUTES (t));
1488     }
1489   return cp_build_qualified_type (result, cp_type_quals (t));
1490 }
1491
1492 /* Like strip_typedefs above, but works on expressions, so that in
1493
1494    template<class T> struct A
1495    {
1496      typedef T TT;
1497      B<sizeof(TT)> b;
1498    };
1499
1500    sizeof(TT) is replaced by sizeof(T).  */
1501
1502 tree
1503 strip_typedefs_expr (tree t, bool *remove_attributes)
1504 {
1505   unsigned i,n;
1506   tree r, type, *ops;
1507   enum tree_code code;
1508
1509   if (t == NULL_TREE || t == error_mark_node)
1510     return t;
1511
1512   if (DECL_P (t) || CONSTANT_CLASS_P (t))
1513     return t;
1514
1515   /* Some expressions have type operands, so let's handle types here rather
1516      than check TYPE_P in multiple places below.  */
1517   if (TYPE_P (t))
1518     return strip_typedefs (t, remove_attributes);
1519
1520   code = TREE_CODE (t);
1521   switch (code)
1522     {
1523     case IDENTIFIER_NODE:
1524     case TEMPLATE_PARM_INDEX:
1525     case OVERLOAD:
1526     case BASELINK:
1527     case ARGUMENT_PACK_SELECT:
1528       return t;
1529
1530     case TRAIT_EXPR:
1531       {
1532         tree type1 = strip_typedefs (TRAIT_EXPR_TYPE1 (t), remove_attributes);
1533         tree type2 = strip_typedefs (TRAIT_EXPR_TYPE2 (t), remove_attributes);
1534         if (type1 == TRAIT_EXPR_TYPE1 (t)
1535             && type2 == TRAIT_EXPR_TYPE2 (t))
1536           return t;
1537         r = copy_node (t);
1538         TRAIT_EXPR_TYPE1 (r) = type1;
1539         TRAIT_EXPR_TYPE2 (r) = type2;
1540         return r;
1541       }
1542
1543     case TREE_LIST:
1544       {
1545         vec<tree, va_gc> *vec = make_tree_vector ();
1546         bool changed = false;
1547         tree it;
1548         for (it = t; it; it = TREE_CHAIN (it))
1549           {
1550             tree val = strip_typedefs_expr (TREE_VALUE (t), remove_attributes);
1551             vec_safe_push (vec, val);
1552             if (val != TREE_VALUE (t))
1553               changed = true;
1554             gcc_assert (TREE_PURPOSE (it) == NULL_TREE);
1555           }
1556         if (changed)
1557           {
1558             r = NULL_TREE;
1559             FOR_EACH_VEC_ELT_REVERSE (*vec, i, it)
1560               r = tree_cons (NULL_TREE, it, r);
1561           }
1562         else
1563           r = t;
1564         release_tree_vector (vec);
1565         return r;
1566       }
1567
1568     case TREE_VEC:
1569       {
1570         bool changed = false;
1571         vec<tree, va_gc> *vec = make_tree_vector ();
1572         n = TREE_VEC_LENGTH (t);
1573         vec_safe_reserve (vec, n);
1574         for (i = 0; i < n; ++i)
1575           {
1576             tree op = strip_typedefs_expr (TREE_VEC_ELT (t, i),
1577                                            remove_attributes);
1578             vec->quick_push (op);
1579             if (op != TREE_VEC_ELT (t, i))
1580               changed = true;
1581           }
1582         if (changed)
1583           {
1584             r = copy_node (t);
1585             for (i = 0; i < n; ++i)
1586               TREE_VEC_ELT (r, i) = (*vec)[i];
1587             NON_DEFAULT_TEMPLATE_ARGS_COUNT (r)
1588               = NON_DEFAULT_TEMPLATE_ARGS_COUNT (t);
1589           }
1590         else
1591           r = t;
1592         release_tree_vector (vec);
1593         return r;
1594       }
1595
1596     case CONSTRUCTOR:
1597       {
1598         bool changed = false;
1599         vec<constructor_elt, va_gc> *vec
1600           = vec_safe_copy (CONSTRUCTOR_ELTS (t));
1601         n = CONSTRUCTOR_NELTS (t);
1602         type = strip_typedefs (TREE_TYPE (t), remove_attributes);
1603         for (i = 0; i < n; ++i)
1604           {
1605             constructor_elt *e = &(*vec)[i];
1606             tree op = strip_typedefs_expr (e->value, remove_attributes);
1607             if (op != e->value)
1608               {
1609                 changed = true;
1610                 e->value = op;
1611               }
1612             gcc_checking_assert
1613               (e->index == strip_typedefs_expr (e->index, remove_attributes));
1614           }
1615
1616         if (!changed && type == TREE_TYPE (t))
1617           {
1618             vec_free (vec);
1619             return t;
1620           }
1621         else
1622           {
1623             r = copy_node (t);
1624             TREE_TYPE (r) = type;
1625             CONSTRUCTOR_ELTS (r) = vec;
1626             return r;
1627           }
1628       }
1629
1630     case LAMBDA_EXPR:
1631       error ("lambda-expression in a constant expression");
1632       return error_mark_node;
1633
1634     default:
1635       break;
1636     }
1637
1638   gcc_assert (EXPR_P (t));
1639
1640   n = TREE_OPERAND_LENGTH (t);
1641   ops = XALLOCAVEC (tree, n);
1642   type = TREE_TYPE (t);
1643
1644   switch (code)
1645     {
1646     CASE_CONVERT:
1647     case IMPLICIT_CONV_EXPR:
1648     case DYNAMIC_CAST_EXPR:
1649     case STATIC_CAST_EXPR:
1650     case CONST_CAST_EXPR:
1651     case REINTERPRET_CAST_EXPR:
1652     case CAST_EXPR:
1653     case NEW_EXPR:
1654       type = strip_typedefs (type, remove_attributes);
1655       /* fallthrough */
1656
1657     default:
1658       for (i = 0; i < n; ++i)
1659         ops[i] = strip_typedefs_expr (TREE_OPERAND (t, i), remove_attributes);
1660       break;
1661     }
1662
1663   /* If nothing changed, return t.  */
1664   for (i = 0; i < n; ++i)
1665     if (ops[i] != TREE_OPERAND (t, i))
1666       break;
1667   if (i == n && type == TREE_TYPE (t))
1668     return t;
1669
1670   r = copy_node (t);
1671   TREE_TYPE (r) = type;
1672   for (i = 0; i < n; ++i)
1673     TREE_OPERAND (r, i) = ops[i];
1674   return r;
1675 }
1676
1677 /* Makes a copy of BINFO and TYPE, which is to be inherited into a
1678    graph dominated by T.  If BINFO is NULL, TYPE is a dependent base,
1679    and we do a shallow copy.  If BINFO is non-NULL, we do a deep copy.
1680    VIRT indicates whether TYPE is inherited virtually or not.
1681    IGO_PREV points at the previous binfo of the inheritance graph
1682    order chain.  The newly copied binfo's TREE_CHAIN forms this
1683    ordering.
1684
1685    The CLASSTYPE_VBASECLASSES vector of T is constructed in the
1686    correct order. That is in the order the bases themselves should be
1687    constructed in.
1688
1689    The BINFO_INHERITANCE of a virtual base class points to the binfo
1690    of the most derived type. ??? We could probably change this so that
1691    BINFO_INHERITANCE becomes synonymous with BINFO_PRIMARY, and hence
1692    remove a field.  They currently can only differ for primary virtual
1693    virtual bases.  */
1694
1695 tree
1696 copy_binfo (tree binfo, tree type, tree t, tree *igo_prev, int virt)
1697 {
1698   tree new_binfo;
1699
1700   if (virt)
1701     {
1702       /* See if we've already made this virtual base.  */
1703       new_binfo = binfo_for_vbase (type, t);
1704       if (new_binfo)
1705         return new_binfo;
1706     }
1707
1708   new_binfo = make_tree_binfo (binfo ? BINFO_N_BASE_BINFOS (binfo) : 0);
1709   BINFO_TYPE (new_binfo) = type;
1710
1711   /* Chain it into the inheritance graph.  */
1712   TREE_CHAIN (*igo_prev) = new_binfo;
1713   *igo_prev = new_binfo;
1714
1715   if (binfo && !BINFO_DEPENDENT_BASE_P (binfo))
1716     {
1717       int ix;
1718       tree base_binfo;
1719
1720       gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), type));
1721
1722       BINFO_OFFSET (new_binfo) = BINFO_OFFSET (binfo);
1723       BINFO_VIRTUALS (new_binfo) = BINFO_VIRTUALS (binfo);
1724
1725       /* We do not need to copy the accesses, as they are read only.  */
1726       BINFO_BASE_ACCESSES (new_binfo) = BINFO_BASE_ACCESSES (binfo);
1727
1728       /* Recursively copy base binfos of BINFO.  */
1729       for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
1730         {
1731           tree new_base_binfo;
1732           new_base_binfo = copy_binfo (base_binfo, BINFO_TYPE (base_binfo),
1733                                        t, igo_prev,
1734                                        BINFO_VIRTUAL_P (base_binfo));
1735
1736           if (!BINFO_INHERITANCE_CHAIN (new_base_binfo))
1737             BINFO_INHERITANCE_CHAIN (new_base_binfo) = new_binfo;
1738           BINFO_BASE_APPEND (new_binfo, new_base_binfo);
1739         }
1740     }
1741   else
1742     BINFO_DEPENDENT_BASE_P (new_binfo) = 1;
1743
1744   if (virt)
1745     {
1746       /* Push it onto the list after any virtual bases it contains
1747          will have been pushed.  */
1748       CLASSTYPE_VBASECLASSES (t)->quick_push (new_binfo);
1749       BINFO_VIRTUAL_P (new_binfo) = 1;
1750       BINFO_INHERITANCE_CHAIN (new_binfo) = TYPE_BINFO (t);
1751     }
1752
1753   return new_binfo;
1754 }
1755 \f
1756 /* Hashing of lists so that we don't make duplicates.
1757    The entry point is `list_hash_canon'.  */
1758
1759 struct list_proxy
1760 {
1761   tree purpose;
1762   tree value;
1763   tree chain;
1764 };
1765
1766 struct list_hasher : ggc_ptr_hash<tree_node>
1767 {
1768   typedef list_proxy *compare_type;
1769
1770   static hashval_t hash (tree);
1771   static bool equal (tree, list_proxy *);
1772 };
1773
1774 /* Now here is the hash table.  When recording a list, it is added
1775    to the slot whose index is the hash code mod the table size.
1776    Note that the hash table is used for several kinds of lists.
1777    While all these live in the same table, they are completely independent,
1778    and the hash code is computed differently for each of these.  */
1779
1780 static GTY (()) hash_table<list_hasher> *list_hash_table;
1781
1782 /* Compare ENTRY (an entry in the hash table) with DATA (a list_proxy
1783    for a node we are thinking about adding).  */
1784
1785 bool
1786 list_hasher::equal (tree t, list_proxy *proxy)
1787 {
1788   return (TREE_VALUE (t) == proxy->value
1789           && TREE_PURPOSE (t) == proxy->purpose
1790           && TREE_CHAIN (t) == proxy->chain);
1791 }
1792
1793 /* Compute a hash code for a list (chain of TREE_LIST nodes
1794    with goodies in the TREE_PURPOSE, TREE_VALUE, and bits of the
1795    TREE_COMMON slots), by adding the hash codes of the individual entries.  */
1796
1797 static hashval_t
1798 list_hash_pieces (tree purpose, tree value, tree chain)
1799 {
1800   hashval_t hashcode = 0;
1801
1802   if (chain)
1803     hashcode += TREE_HASH (chain);
1804
1805   if (value)
1806     hashcode += TREE_HASH (value);
1807   else
1808     hashcode += 1007;
1809   if (purpose)
1810     hashcode += TREE_HASH (purpose);
1811   else
1812     hashcode += 1009;
1813   return hashcode;
1814 }
1815
1816 /* Hash an already existing TREE_LIST.  */
1817
1818 hashval_t
1819 list_hasher::hash (tree t)
1820 {
1821   return list_hash_pieces (TREE_PURPOSE (t),
1822                            TREE_VALUE (t),
1823                            TREE_CHAIN (t));
1824 }
1825
1826 /* Given list components PURPOSE, VALUE, AND CHAIN, return the canonical
1827    object for an identical list if one already exists.  Otherwise, build a
1828    new one, and record it as the canonical object.  */
1829
1830 tree
1831 hash_tree_cons (tree purpose, tree value, tree chain)
1832 {
1833   int hashcode = 0;
1834   tree *slot;
1835   struct list_proxy proxy;
1836
1837   /* Hash the list node.  */
1838   hashcode = list_hash_pieces (purpose, value, chain);
1839   /* Create a proxy for the TREE_LIST we would like to create.  We
1840      don't actually create it so as to avoid creating garbage.  */
1841   proxy.purpose = purpose;
1842   proxy.value = value;
1843   proxy.chain = chain;
1844   /* See if it is already in the table.  */
1845   slot = list_hash_table->find_slot_with_hash (&proxy, hashcode, INSERT);
1846   /* If not, create a new node.  */
1847   if (!*slot)
1848     *slot = tree_cons (purpose, value, chain);
1849   return (tree) *slot;
1850 }
1851
1852 /* Constructor for hashed lists.  */
1853
1854 tree
1855 hash_tree_chain (tree value, tree chain)
1856 {
1857   return hash_tree_cons (NULL_TREE, value, chain);
1858 }
1859 \f
1860 void
1861 debug_binfo (tree elem)
1862 {
1863   HOST_WIDE_INT n;
1864   tree virtuals;
1865
1866   fprintf (stderr, "type \"%s\", offset = " HOST_WIDE_INT_PRINT_DEC
1867            "\nvtable type:\n",
1868            TYPE_NAME_STRING (BINFO_TYPE (elem)),
1869            TREE_INT_CST_LOW (BINFO_OFFSET (elem)));
1870   debug_tree (BINFO_TYPE (elem));
1871   if (BINFO_VTABLE (elem))
1872     fprintf (stderr, "vtable decl \"%s\"\n",
1873              IDENTIFIER_POINTER (DECL_NAME (get_vtbl_decl_for_binfo (elem))));
1874   else
1875     fprintf (stderr, "no vtable decl yet\n");
1876   fprintf (stderr, "virtuals:\n");
1877   virtuals = BINFO_VIRTUALS (elem);
1878   n = 0;
1879
1880   while (virtuals)
1881     {
1882       tree fndecl = TREE_VALUE (virtuals);
1883       fprintf (stderr, "%s [%ld =? %ld]\n",
1884                IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (fndecl)),
1885                (long) n, (long) TREE_INT_CST_LOW (DECL_VINDEX (fndecl)));
1886       ++n;
1887       virtuals = TREE_CHAIN (virtuals);
1888     }
1889 }
1890
1891 /* Build a representation for the qualified name SCOPE::NAME.  TYPE is
1892    the type of the result expression, if known, or NULL_TREE if the
1893    resulting expression is type-dependent.  If TEMPLATE_P is true,
1894    NAME is known to be a template because the user explicitly used the
1895    "template" keyword after the "::".
1896
1897    All SCOPE_REFs should be built by use of this function.  */
1898
1899 tree
1900 build_qualified_name (tree type, tree scope, tree name, bool template_p)
1901 {
1902   tree t;
1903   if (type == error_mark_node
1904       || scope == error_mark_node
1905       || name == error_mark_node)
1906     return error_mark_node;
1907   t = build2 (SCOPE_REF, type, scope, name);
1908   QUALIFIED_NAME_IS_TEMPLATE (t) = template_p;
1909   PTRMEM_OK_P (t) = true;
1910   if (type)
1911     t = convert_from_reference (t);
1912   return t;
1913 }
1914
1915 /* Like check_qualified_type, but also check ref-qualifier and exception
1916    specification.  */
1917
1918 static bool
1919 cp_check_qualified_type (const_tree cand, const_tree base, int type_quals,
1920                          cp_ref_qualifier rqual, tree raises)
1921 {
1922   return (check_qualified_type (cand, base, type_quals)
1923           && comp_except_specs (raises, TYPE_RAISES_EXCEPTIONS (cand),
1924                                 ce_exact)
1925           && type_memfn_rqual (cand) == rqual);
1926 }
1927
1928 /* Build the FUNCTION_TYPE or METHOD_TYPE with the ref-qualifier RQUAL.  */
1929
1930 tree
1931 build_ref_qualified_type (tree type, cp_ref_qualifier rqual)
1932 {
1933   tree t;
1934
1935   if (rqual == type_memfn_rqual (type))
1936     return type;
1937
1938   int type_quals = TYPE_QUALS (type);
1939   tree raises = TYPE_RAISES_EXCEPTIONS (type);
1940   for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
1941     if (cp_check_qualified_type (t, type, type_quals, rqual, raises))
1942       return t;
1943
1944   t = build_variant_type_copy (type);
1945   switch (rqual)
1946     {
1947     case REF_QUAL_RVALUE:
1948       FUNCTION_RVALUE_QUALIFIED (t) = 1;
1949       FUNCTION_REF_QUALIFIED (t) = 1;
1950       break;
1951     case REF_QUAL_LVALUE:
1952       FUNCTION_RVALUE_QUALIFIED (t) = 0;
1953       FUNCTION_REF_QUALIFIED (t) = 1;
1954       break;
1955     default:
1956       FUNCTION_REF_QUALIFIED (t) = 0;
1957       break;
1958     }
1959
1960   if (TYPE_STRUCTURAL_EQUALITY_P (type))
1961     /* Propagate structural equality. */
1962     SET_TYPE_STRUCTURAL_EQUALITY (t);
1963   else if (TYPE_CANONICAL (type) != type)
1964     /* Build the underlying canonical type, since it is different
1965        from TYPE. */
1966     TYPE_CANONICAL (t) = build_ref_qualified_type (TYPE_CANONICAL (type),
1967                                                    rqual);
1968   else
1969     /* T is its own canonical type. */
1970     TYPE_CANONICAL (t) = t;
1971
1972   return t;
1973 }
1974
1975 /* Returns nonzero if X is an expression for a (possibly overloaded)
1976    function.  If "f" is a function or function template, "f", "c->f",
1977    "c.f", "C::f", and "f<int>" will all be considered possibly
1978    overloaded functions.  Returns 2 if the function is actually
1979    overloaded, i.e., if it is impossible to know the type of the
1980    function without performing overload resolution.  */
1981
1982 int
1983 is_overloaded_fn (tree x)
1984 {
1985   /* A baselink is also considered an overloaded function.  */
1986   if (TREE_CODE (x) == OFFSET_REF
1987       || TREE_CODE (x) == COMPONENT_REF)
1988     x = TREE_OPERAND (x, 1);
1989   if (BASELINK_P (x))
1990     x = BASELINK_FUNCTIONS (x);
1991   if (TREE_CODE (x) == TEMPLATE_ID_EXPR)
1992     x = TREE_OPERAND (x, 0);
1993   if (DECL_FUNCTION_TEMPLATE_P (OVL_CURRENT (x))
1994       || (TREE_CODE (x) == OVERLOAD && OVL_CHAIN (x)))
1995     return 2;
1996   return  (TREE_CODE (x) == FUNCTION_DECL
1997            || TREE_CODE (x) == OVERLOAD);
1998 }
1999
2000 /* X is the CALL_EXPR_FN of a CALL_EXPR.  If X represents a dependent name
2001    (14.6.2), return the IDENTIFIER_NODE for that name.  Otherwise, return
2002    NULL_TREE.  */
2003
2004 tree
2005 dependent_name (tree x)
2006 {
2007   if (identifier_p (x))
2008     return x;
2009   if (TREE_CODE (x) != COMPONENT_REF
2010       && TREE_CODE (x) != OFFSET_REF
2011       && TREE_CODE (x) != BASELINK
2012       && is_overloaded_fn (x))
2013     return DECL_NAME (get_first_fn (x));
2014   return NULL_TREE;
2015 }
2016
2017 /* Returns true iff X is an expression for an overloaded function
2018    whose type cannot be known without performing overload
2019    resolution.  */
2020
2021 bool
2022 really_overloaded_fn (tree x)
2023 {
2024   return is_overloaded_fn (x) == 2;
2025 }
2026
2027 tree
2028 get_fns (tree from)
2029 {
2030   gcc_assert (is_overloaded_fn (from));
2031   /* A baselink is also considered an overloaded function.  */
2032   if (TREE_CODE (from) == OFFSET_REF
2033       || TREE_CODE (from) == COMPONENT_REF)
2034     from = TREE_OPERAND (from, 1);
2035   if (BASELINK_P (from))
2036     from = BASELINK_FUNCTIONS (from);
2037   if (TREE_CODE (from) == TEMPLATE_ID_EXPR)
2038     from = TREE_OPERAND (from, 0);
2039   return from;
2040 }
2041
2042 tree
2043 get_first_fn (tree from)
2044 {
2045   return OVL_CURRENT (get_fns (from));
2046 }
2047
2048 /* Return a new OVL node, concatenating it with the old one.  */
2049
2050 tree
2051 ovl_cons (tree decl, tree chain)
2052 {
2053   tree result = make_node (OVERLOAD);
2054   TREE_TYPE (result) = unknown_type_node;
2055   OVL_FUNCTION (result) = decl;
2056   TREE_CHAIN (result) = chain;
2057
2058   return result;
2059 }
2060
2061 /* Build a new overloaded function. If this is the first one,
2062    just return it; otherwise, ovl_cons the _DECLs */
2063
2064 tree
2065 build_overload (tree decl, tree chain)
2066 {
2067   if (! chain && TREE_CODE (decl) != TEMPLATE_DECL)
2068     return decl;
2069   return ovl_cons (decl, chain);
2070 }
2071
2072 /* Return the scope where the overloaded functions OVL were found.  */
2073
2074 tree
2075 ovl_scope (tree ovl)
2076 {
2077   if (TREE_CODE (ovl) == OFFSET_REF
2078       || TREE_CODE (ovl) == COMPONENT_REF)
2079     ovl = TREE_OPERAND (ovl, 1);
2080   if (TREE_CODE (ovl) == BASELINK)
2081     return BINFO_TYPE (BASELINK_BINFO (ovl));
2082   if (TREE_CODE (ovl) == TEMPLATE_ID_EXPR)
2083     ovl = TREE_OPERAND (ovl, 0);
2084   /* Skip using-declarations.  */
2085   while (TREE_CODE (ovl) == OVERLOAD && OVL_USED (ovl) && OVL_CHAIN (ovl))
2086     ovl = OVL_CHAIN (ovl);
2087   return CP_DECL_CONTEXT (OVL_CURRENT (ovl));
2088 }
2089
2090 /* Return TRUE if FN is a non-static member function, FALSE otherwise.
2091    This function looks into BASELINK and OVERLOAD nodes.  */
2092
2093 bool
2094 non_static_member_function_p (tree fn)
2095 {
2096   if (fn == NULL_TREE)
2097     return false;
2098
2099   if (is_overloaded_fn (fn))
2100     fn = get_first_fn (fn);
2101
2102   return (DECL_P (fn)
2103           && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn));
2104 }
2105
2106 \f
2107 #define PRINT_RING_SIZE 4
2108
2109 static const char *
2110 cxx_printable_name_internal (tree decl, int v, bool translate)
2111 {
2112   static unsigned int uid_ring[PRINT_RING_SIZE];
2113   static char *print_ring[PRINT_RING_SIZE];
2114   static bool trans_ring[PRINT_RING_SIZE];
2115   static int ring_counter;
2116   int i;
2117
2118   /* Only cache functions.  */
2119   if (v < 2
2120       || TREE_CODE (decl) != FUNCTION_DECL
2121       || DECL_LANG_SPECIFIC (decl) == 0)
2122     return lang_decl_name (decl, v, translate);
2123
2124   /* See if this print name is lying around.  */
2125   for (i = 0; i < PRINT_RING_SIZE; i++)
2126     if (uid_ring[i] == DECL_UID (decl) && translate == trans_ring[i])
2127       /* yes, so return it.  */
2128       return print_ring[i];
2129
2130   if (++ring_counter == PRINT_RING_SIZE)
2131     ring_counter = 0;
2132
2133   if (current_function_decl != NULL_TREE)
2134     {
2135       /* There may be both translated and untranslated versions of the
2136          name cached.  */
2137       for (i = 0; i < 2; i++)
2138         {
2139           if (uid_ring[ring_counter] == DECL_UID (current_function_decl))
2140             ring_counter += 1;
2141           if (ring_counter == PRINT_RING_SIZE)
2142             ring_counter = 0;
2143         }
2144       gcc_assert (uid_ring[ring_counter] != DECL_UID (current_function_decl));
2145     }
2146
2147   free (print_ring[ring_counter]);
2148
2149   print_ring[ring_counter] = xstrdup (lang_decl_name (decl, v, translate));
2150   uid_ring[ring_counter] = DECL_UID (decl);
2151   trans_ring[ring_counter] = translate;
2152   return print_ring[ring_counter];
2153 }
2154
2155 const char *
2156 cxx_printable_name (tree decl, int v)
2157 {
2158   return cxx_printable_name_internal (decl, v, false);
2159 }
2160
2161 const char *
2162 cxx_printable_name_translate (tree decl, int v)
2163 {
2164   return cxx_printable_name_internal (decl, v, true);
2165 }
2166 \f
2167 /* Build the FUNCTION_TYPE or METHOD_TYPE which may throw exceptions
2168    listed in RAISES.  */
2169
2170 tree
2171 build_exception_variant (tree type, tree raises)
2172 {
2173   tree v;
2174   int type_quals;
2175
2176   if (comp_except_specs (raises, TYPE_RAISES_EXCEPTIONS (type), ce_exact))
2177     return type;
2178
2179   type_quals = TYPE_QUALS (type);
2180   cp_ref_qualifier rqual = type_memfn_rqual (type);
2181   for (v = TYPE_MAIN_VARIANT (type); v; v = TYPE_NEXT_VARIANT (v))
2182     if (cp_check_qualified_type (v, type, type_quals, rqual, raises))
2183       return v;
2184
2185   /* Need to build a new variant.  */
2186   v = build_variant_type_copy (type);
2187   TYPE_RAISES_EXCEPTIONS (v) = raises;
2188   return v;
2189 }
2190
2191 /* Given a TEMPLATE_TEMPLATE_PARM node T, create a new
2192    BOUND_TEMPLATE_TEMPLATE_PARM bound with NEWARGS as its template
2193    arguments.  */
2194
2195 tree
2196 bind_template_template_parm (tree t, tree newargs)
2197 {
2198   tree decl = TYPE_NAME (t);
2199   tree t2;
2200
2201   t2 = cxx_make_type (BOUND_TEMPLATE_TEMPLATE_PARM);
2202   decl = build_decl (input_location,
2203                      TYPE_DECL, DECL_NAME (decl), NULL_TREE);
2204
2205   /* These nodes have to be created to reflect new TYPE_DECL and template
2206      arguments.  */
2207   TEMPLATE_TYPE_PARM_INDEX (t2) = copy_node (TEMPLATE_TYPE_PARM_INDEX (t));
2208   TEMPLATE_PARM_DECL (TEMPLATE_TYPE_PARM_INDEX (t2)) = decl;
2209   TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t2)
2210     = build_template_info (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t), newargs);
2211
2212   TREE_TYPE (decl) = t2;
2213   TYPE_NAME (t2) = decl;
2214   TYPE_STUB_DECL (t2) = decl;
2215   TYPE_SIZE (t2) = 0;
2216   SET_TYPE_STRUCTURAL_EQUALITY (t2);
2217
2218   return t2;
2219 }
2220
2221 /* Called from count_trees via walk_tree.  */
2222
2223 static tree
2224 count_trees_r (tree *tp, int *walk_subtrees, void *data)
2225 {
2226   ++*((int *) data);
2227
2228   if (TYPE_P (*tp))
2229     *walk_subtrees = 0;
2230
2231   return NULL_TREE;
2232 }
2233
2234 /* Debugging function for measuring the rough complexity of a tree
2235    representation.  */
2236
2237 int
2238 count_trees (tree t)
2239 {
2240   int n_trees = 0;
2241   cp_walk_tree_without_duplicates (&t, count_trees_r, &n_trees);
2242   return n_trees;
2243 }
2244
2245 /* Called from verify_stmt_tree via walk_tree.  */
2246
2247 static tree
2248 verify_stmt_tree_r (tree* tp, int * /*walk_subtrees*/, void* data)
2249 {
2250   tree t = *tp;
2251   hash_table<nofree_ptr_hash <tree_node> > *statements
2252       = static_cast <hash_table<nofree_ptr_hash <tree_node> > *> (data);
2253   tree_node **slot;
2254
2255   if (!STATEMENT_CODE_P (TREE_CODE (t)))
2256     return NULL_TREE;
2257
2258   /* If this statement is already present in the hash table, then
2259      there is a circularity in the statement tree.  */
2260   gcc_assert (!statements->find (t));
2261
2262   slot = statements->find_slot (t, INSERT);
2263   *slot = t;
2264
2265   return NULL_TREE;
2266 }
2267
2268 /* Debugging function to check that the statement T has not been
2269    corrupted.  For now, this function simply checks that T contains no
2270    circularities.  */
2271
2272 void
2273 verify_stmt_tree (tree t)
2274 {
2275   hash_table<nofree_ptr_hash <tree_node> > statements (37);
2276   cp_walk_tree (&t, verify_stmt_tree_r, &statements, NULL);
2277 }
2278
2279 /* Check if the type T depends on a type with no linkage and if so, return
2280    it.  If RELAXED_P then do not consider a class type declared within
2281    a vague-linkage function to have no linkage.  */
2282
2283 tree
2284 no_linkage_check (tree t, bool relaxed_p)
2285 {
2286   tree r;
2287
2288   /* There's no point in checking linkage on template functions; we
2289      can't know their complete types.  */
2290   if (processing_template_decl)
2291     return NULL_TREE;
2292
2293   switch (TREE_CODE (t))
2294     {
2295     case RECORD_TYPE:
2296       if (TYPE_PTRMEMFUNC_P (t))
2297         goto ptrmem;
2298       /* Lambda types that don't have mangling scope have no linkage.  We
2299          check CLASSTYPE_LAMBDA_EXPR for error_mark_node because
2300          when we get here from pushtag none of the lambda information is
2301          set up yet, so we want to assume that the lambda has linkage and
2302          fix it up later if not.  */
2303       if (CLASSTYPE_LAMBDA_EXPR (t)
2304           && CLASSTYPE_LAMBDA_EXPR (t) != error_mark_node
2305           && LAMBDA_TYPE_EXTRA_SCOPE (t) == NULL_TREE)
2306         return t;
2307       /* Fall through.  */
2308     case UNION_TYPE:
2309       if (!CLASS_TYPE_P (t))
2310         return NULL_TREE;
2311       /* Fall through.  */
2312     case ENUMERAL_TYPE:
2313       /* Only treat anonymous types as having no linkage if they're at
2314          namespace scope.  This is core issue 966.  */
2315       if (TYPE_ANONYMOUS_P (t) && TYPE_NAMESPACE_SCOPE_P (t))
2316         return t;
2317
2318       for (r = CP_TYPE_CONTEXT (t); ; )
2319         {
2320           /* If we're a nested type of a !TREE_PUBLIC class, we might not
2321              have linkage, or we might just be in an anonymous namespace.
2322              If we're in a TREE_PUBLIC class, we have linkage.  */
2323           if (TYPE_P (r) && !TREE_PUBLIC (TYPE_NAME (r)))
2324             return no_linkage_check (TYPE_CONTEXT (t), relaxed_p);
2325           else if (TREE_CODE (r) == FUNCTION_DECL)
2326             {
2327               if (!relaxed_p || !vague_linkage_p (r))
2328                 return t;
2329               else
2330                 r = CP_DECL_CONTEXT (r);
2331             }
2332           else
2333             break;
2334         }
2335
2336       return NULL_TREE;
2337
2338     case ARRAY_TYPE:
2339     case POINTER_TYPE:
2340     case REFERENCE_TYPE:
2341     case VECTOR_TYPE:
2342       return no_linkage_check (TREE_TYPE (t), relaxed_p);
2343
2344     case OFFSET_TYPE:
2345     ptrmem:
2346       r = no_linkage_check (TYPE_PTRMEM_POINTED_TO_TYPE (t),
2347                             relaxed_p);
2348       if (r)
2349         return r;
2350       return no_linkage_check (TYPE_PTRMEM_CLASS_TYPE (t), relaxed_p);
2351
2352     case METHOD_TYPE:
2353     case FUNCTION_TYPE:
2354       {
2355         tree parm = TYPE_ARG_TYPES (t);
2356         if (TREE_CODE (t) == METHOD_TYPE)
2357           /* The 'this' pointer isn't interesting; a method has the same
2358              linkage (or lack thereof) as its enclosing class.  */
2359           parm = TREE_CHAIN (parm);
2360         for (;
2361              parm && parm != void_list_node;
2362              parm = TREE_CHAIN (parm))
2363           {
2364             r = no_linkage_check (TREE_VALUE (parm), relaxed_p);
2365             if (r)
2366               return r;
2367           }
2368         return no_linkage_check (TREE_TYPE (t), relaxed_p);
2369       }
2370
2371     default:
2372       return NULL_TREE;
2373     }
2374 }
2375
2376 extern int depth_reached;
2377
2378 void
2379 cxx_print_statistics (void)
2380 {
2381   print_search_statistics ();
2382   print_class_statistics ();
2383   print_template_statistics ();
2384   if (GATHER_STATISTICS)
2385     fprintf (stderr, "maximum template instantiation depth reached: %d\n",
2386              depth_reached);
2387 }
2388
2389 /* Return, as an INTEGER_CST node, the number of elements for TYPE
2390    (which is an ARRAY_TYPE).  This counts only elements of the top
2391    array.  */
2392
2393 tree
2394 array_type_nelts_top (tree type)
2395 {
2396   return fold_build2_loc (input_location,
2397                       PLUS_EXPR, sizetype,
2398                       array_type_nelts (type),
2399                       size_one_node);
2400 }
2401
2402 /* Return, as an INTEGER_CST node, the number of elements for TYPE
2403    (which is an ARRAY_TYPE).  This one is a recursive count of all
2404    ARRAY_TYPEs that are clumped together.  */
2405
2406 tree
2407 array_type_nelts_total (tree type)
2408 {
2409   tree sz = array_type_nelts_top (type);
2410   type = TREE_TYPE (type);
2411   while (TREE_CODE (type) == ARRAY_TYPE)
2412     {
2413       tree n = array_type_nelts_top (type);
2414       sz = fold_build2_loc (input_location,
2415                         MULT_EXPR, sizetype, sz, n);
2416       type = TREE_TYPE (type);
2417     }
2418   return sz;
2419 }
2420
2421 /* Called from break_out_target_exprs via mapcar.  */
2422
2423 static tree
2424 bot_manip (tree* tp, int* walk_subtrees, void* data)
2425 {
2426   splay_tree target_remap = ((splay_tree) data);
2427   tree t = *tp;
2428
2429   if (!TYPE_P (t) && TREE_CONSTANT (t) && !TREE_SIDE_EFFECTS (t))
2430     {
2431       /* There can't be any TARGET_EXPRs or their slot variables below this
2432          point.  But we must make a copy, in case subsequent processing
2433          alters any part of it.  For example, during gimplification a cast
2434          of the form (T) &X::f (where "f" is a member function) will lead
2435          to replacing the PTRMEM_CST for &X::f with a VAR_DECL.  */
2436       *walk_subtrees = 0;
2437       *tp = unshare_expr (t);
2438       return NULL_TREE;
2439     }
2440   if (TREE_CODE (t) == TARGET_EXPR)
2441     {
2442       tree u;
2443
2444       if (TREE_CODE (TREE_OPERAND (t, 1)) == AGGR_INIT_EXPR)
2445         {
2446           u = build_cplus_new (TREE_TYPE (t), TREE_OPERAND (t, 1),
2447                                tf_warning_or_error);
2448           if (AGGR_INIT_ZERO_FIRST (TREE_OPERAND (t, 1)))
2449             AGGR_INIT_ZERO_FIRST (TREE_OPERAND (u, 1)) = true;
2450         }
2451       else
2452         u = build_target_expr_with_type (TREE_OPERAND (t, 1), TREE_TYPE (t),
2453                                          tf_warning_or_error);
2454
2455       TARGET_EXPR_IMPLICIT_P (u) = TARGET_EXPR_IMPLICIT_P (t);
2456       TARGET_EXPR_LIST_INIT_P (u) = TARGET_EXPR_LIST_INIT_P (t);
2457       TARGET_EXPR_DIRECT_INIT_P (u) = TARGET_EXPR_DIRECT_INIT_P (t);
2458
2459       /* Map the old variable to the new one.  */
2460       splay_tree_insert (target_remap,
2461                          (splay_tree_key) TREE_OPERAND (t, 0),
2462                          (splay_tree_value) TREE_OPERAND (u, 0));
2463
2464       TREE_OPERAND (u, 1) = break_out_target_exprs (TREE_OPERAND (u, 1));
2465
2466       /* Replace the old expression with the new version.  */
2467       *tp = u;
2468       /* We don't have to go below this point; the recursive call to
2469          break_out_target_exprs will have handled anything below this
2470          point.  */
2471       *walk_subtrees = 0;
2472       return NULL_TREE;
2473     }
2474   if (TREE_CODE (*tp) == SAVE_EXPR)
2475     {
2476       t = *tp;
2477       splay_tree_node n = splay_tree_lookup (target_remap,
2478                                              (splay_tree_key) t);
2479       if (n)
2480         {
2481           *tp = (tree)n->value;
2482           *walk_subtrees = 0;
2483         }
2484       else
2485         {
2486           copy_tree_r (tp, walk_subtrees, NULL);
2487           splay_tree_insert (target_remap,
2488                              (splay_tree_key)t,
2489                              (splay_tree_value)*tp);
2490           /* Make sure we don't remap an already-remapped SAVE_EXPR.  */
2491           splay_tree_insert (target_remap,
2492                              (splay_tree_key)*tp,
2493                              (splay_tree_value)*tp);
2494         }
2495       return NULL_TREE;
2496     }
2497
2498   /* Make a copy of this node.  */
2499   t = copy_tree_r (tp, walk_subtrees, NULL);
2500   if (TREE_CODE (*tp) == CALL_EXPR)
2501     {
2502       set_flags_from_callee (*tp);
2503
2504       /* builtin_LINE and builtin_FILE get the location where the default
2505          argument is expanded, not where the call was written.  */
2506       tree callee = get_callee_fndecl (*tp);
2507       if (callee && DECL_BUILT_IN (callee))
2508         switch (DECL_FUNCTION_CODE (callee))
2509           {
2510           case BUILT_IN_FILE:
2511           case BUILT_IN_LINE:
2512             SET_EXPR_LOCATION (*tp, input_location);
2513           default:
2514             break;
2515           }
2516     }
2517   return t;
2518 }
2519
2520 /* Replace all remapped VAR_DECLs in T with their new equivalents.
2521    DATA is really a splay-tree mapping old variables to new
2522    variables.  */
2523
2524 static tree
2525 bot_replace (tree* t, int* /*walk_subtrees*/, void* data)
2526 {
2527   splay_tree target_remap = ((splay_tree) data);
2528
2529   if (VAR_P (*t))
2530     {
2531       splay_tree_node n = splay_tree_lookup (target_remap,
2532                                              (splay_tree_key) *t);
2533       if (n)
2534         *t = (tree) n->value;
2535     }
2536   else if (TREE_CODE (*t) == PARM_DECL
2537            && DECL_NAME (*t) == this_identifier
2538            && !DECL_CONTEXT (*t))
2539     {
2540       /* In an NSDMI we need to replace the 'this' parameter we used for
2541          parsing with the real one for this function.  */
2542       *t = current_class_ptr;
2543     }
2544   else if (TREE_CODE (*t) == CONVERT_EXPR
2545            && CONVERT_EXPR_VBASE_PATH (*t))
2546     {
2547       /* In an NSDMI build_base_path defers building conversions to virtual
2548          bases, and we handle it here.  */
2549       tree basetype = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (*t)));
2550       vec<tree, va_gc> *vbases = CLASSTYPE_VBASECLASSES (current_class_type);
2551       int i; tree binfo;
2552       FOR_EACH_VEC_SAFE_ELT (vbases, i, binfo)
2553         if (BINFO_TYPE (binfo) == basetype)
2554           break;
2555       *t = build_base_path (PLUS_EXPR, TREE_OPERAND (*t, 0), binfo, true,
2556                             tf_warning_or_error);
2557     }
2558
2559   return NULL_TREE;
2560 }
2561
2562 /* When we parse a default argument expression, we may create
2563    temporary variables via TARGET_EXPRs.  When we actually use the
2564    default-argument expression, we make a copy of the expression
2565    and replace the temporaries with appropriate local versions.  */
2566
2567 tree
2568 break_out_target_exprs (tree t)
2569 {
2570   static int target_remap_count;
2571   static splay_tree target_remap;
2572
2573   if (!target_remap_count++)
2574     target_remap = splay_tree_new (splay_tree_compare_pointers,
2575                                    /*splay_tree_delete_key_fn=*/NULL,
2576                                    /*splay_tree_delete_value_fn=*/NULL);
2577   cp_walk_tree (&t, bot_manip, target_remap, NULL);
2578   cp_walk_tree (&t, bot_replace, target_remap, NULL);
2579
2580   if (!--target_remap_count)
2581     {
2582       splay_tree_delete (target_remap);
2583       target_remap = NULL;
2584     }
2585
2586   return t;
2587 }
2588
2589 /* Build an expression for the subobject of OBJ at CONSTRUCTOR index INDEX,
2590    which we expect to have type TYPE.  */
2591
2592 tree
2593 build_ctor_subob_ref (tree index, tree type, tree obj)
2594 {
2595   if (index == NULL_TREE)
2596     /* Can't refer to a particular member of a vector.  */
2597     obj = NULL_TREE;
2598   else if (TREE_CODE (index) == INTEGER_CST)
2599     obj = cp_build_array_ref (input_location, obj, index, tf_none);
2600   else
2601     obj = build_class_member_access_expr (obj, index, NULL_TREE,
2602                                           /*reference*/false, tf_none);
2603   if (obj)
2604     {
2605       tree objtype = TREE_TYPE (obj);
2606       if (TREE_CODE (objtype) == ARRAY_TYPE && !TYPE_DOMAIN (objtype))
2607         {
2608           /* When the destination object refers to a flexible array member
2609              verify that it matches the type of the source object except
2610              for its domain and qualifiers.  */
2611           gcc_assert (comptypes (TYPE_MAIN_VARIANT (type),
2612                                  TYPE_MAIN_VARIANT (objtype),
2613                                  COMPARE_REDECLARATION));
2614         }
2615       else
2616         gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, objtype));
2617     }
2618
2619   return obj;
2620 }
2621
2622 /* Like substitute_placeholder_in_expr, but handle C++ tree codes and
2623    build up subexpressions as we go deeper.  */
2624
2625 static tree
2626 replace_placeholders_r (tree* t, int* walk_subtrees, void* data_)
2627 {
2628   tree obj = static_cast<tree>(data_);
2629
2630   if (TREE_CONSTANT (*t))
2631     {
2632       *walk_subtrees = false;
2633       return NULL_TREE;
2634     }
2635
2636   switch (TREE_CODE (*t))
2637     {
2638     case PLACEHOLDER_EXPR:
2639       {
2640         tree x = obj;
2641         for (; !(same_type_ignoring_top_level_qualifiers_p
2642                  (TREE_TYPE (*t), TREE_TYPE (x)));
2643              x = TREE_OPERAND (x, 0))
2644           gcc_assert (TREE_CODE (x) == COMPONENT_REF);
2645         *t = x;
2646         *walk_subtrees = false;
2647       }
2648       break;
2649
2650     case CONSTRUCTOR:
2651       {
2652         constructor_elt *ce;
2653         vec<constructor_elt,va_gc> *v = CONSTRUCTOR_ELTS (*t);
2654         for (unsigned i = 0; vec_safe_iterate (v, i, &ce); ++i)
2655           {
2656             tree *valp = &ce->value;
2657             tree type = TREE_TYPE (*valp);
2658             tree subob = obj;
2659
2660             if (TREE_CODE (*valp) == CONSTRUCTOR
2661                 && AGGREGATE_TYPE_P (type))
2662               {
2663                 /* If we're looking at the initializer for OBJ, then build
2664                    a sub-object reference.  If we're looking at an
2665                    initializer for another object, just pass OBJ down.  */
2666                 if (same_type_ignoring_top_level_qualifiers_p
2667                     (TREE_TYPE (*t), TREE_TYPE (obj)))
2668                   subob = build_ctor_subob_ref (ce->index, type, obj);
2669                 if (TREE_CODE (*valp) == TARGET_EXPR)
2670                   valp = &TARGET_EXPR_INITIAL (*valp);
2671               }
2672
2673             cp_walk_tree (valp, replace_placeholders_r,
2674                           subob, NULL);
2675           }
2676         *walk_subtrees = false;
2677         break;
2678       }
2679
2680     default:
2681       break;
2682     }
2683
2684   return NULL_TREE;
2685 }
2686
2687 tree
2688 replace_placeholders (tree exp, tree obj)
2689 {
2690   tree *tp = &exp;
2691   if (TREE_CODE (exp) == TARGET_EXPR)
2692     tp = &TARGET_EXPR_INITIAL (exp);
2693   cp_walk_tree (tp, replace_placeholders_r, obj, NULL);
2694   return exp;
2695 }
2696
2697 /* Similar to `build_nt', but for template definitions of dependent
2698    expressions  */
2699
2700 tree
2701 build_min_nt_loc (location_t loc, enum tree_code code, ...)
2702 {
2703   tree t;
2704   int length;
2705   int i;
2706   va_list p;
2707
2708   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
2709
2710   va_start (p, code);
2711
2712   t = make_node (code);
2713   SET_EXPR_LOCATION (t, loc);
2714   length = TREE_CODE_LENGTH (code);
2715
2716   for (i = 0; i < length; i++)
2717     {
2718       tree x = va_arg (p, tree);
2719       TREE_OPERAND (t, i) = x;
2720     }
2721
2722   va_end (p);
2723   return t;
2724 }
2725
2726
2727 /* Similar to `build', but for template definitions.  */
2728
2729 tree
2730 build_min (enum tree_code code, tree tt, ...)
2731 {
2732   tree t;
2733   int length;
2734   int i;
2735   va_list p;
2736
2737   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
2738
2739   va_start (p, tt);
2740
2741   t = make_node (code);
2742   length = TREE_CODE_LENGTH (code);
2743   TREE_TYPE (t) = tt;
2744
2745   for (i = 0; i < length; i++)
2746     {
2747       tree x = va_arg (p, tree);
2748       TREE_OPERAND (t, i) = x;
2749       if (x && !TYPE_P (x) && TREE_SIDE_EFFECTS (x))
2750         TREE_SIDE_EFFECTS (t) = 1;
2751     }
2752
2753   va_end (p);
2754   return t;
2755 }
2756
2757 /* Similar to `build', but for template definitions of non-dependent
2758    expressions. NON_DEP is the non-dependent expression that has been
2759    built.  */
2760
2761 tree
2762 build_min_non_dep (enum tree_code code, tree non_dep, ...)
2763 {
2764   tree t;
2765   int length;
2766   int i;
2767   va_list p;
2768
2769   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
2770
2771   va_start (p, non_dep);
2772
2773   if (REFERENCE_REF_P (non_dep))
2774     non_dep = TREE_OPERAND (non_dep, 0);
2775
2776   t = make_node (code);
2777   length = TREE_CODE_LENGTH (code);
2778   TREE_TYPE (t) = TREE_TYPE (non_dep);
2779   TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (non_dep);
2780
2781   for (i = 0; i < length; i++)
2782     {
2783       tree x = va_arg (p, tree);
2784       TREE_OPERAND (t, i) = x;
2785     }
2786
2787   if (code == COMPOUND_EXPR && TREE_CODE (non_dep) != COMPOUND_EXPR)
2788     /* This should not be considered a COMPOUND_EXPR, because it
2789        resolves to an overload.  */
2790     COMPOUND_EXPR_OVERLOADED (t) = 1;
2791
2792   va_end (p);
2793   return convert_from_reference (t);
2794 }
2795
2796 /* Similar to `build_nt_call_vec', but for template definitions of
2797    non-dependent expressions. NON_DEP is the non-dependent expression
2798    that has been built.  */
2799
2800 tree
2801 build_min_non_dep_call_vec (tree non_dep, tree fn, vec<tree, va_gc> *argvec)
2802 {
2803   tree t = build_nt_call_vec (fn, argvec);
2804   if (REFERENCE_REF_P (non_dep))
2805     non_dep = TREE_OPERAND (non_dep, 0);
2806   TREE_TYPE (t) = TREE_TYPE (non_dep);
2807   TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (non_dep);
2808   return convert_from_reference (t);
2809 }
2810
2811 /* Similar to build_min_non_dep, but for expressions that have been resolved to
2812    a call to an operator overload.  OP is the operator that has been
2813    overloaded.  NON_DEP is the non-dependent expression that's been built,
2814    which should be a CALL_EXPR or an INDIRECT_REF to a CALL_EXPR.  OVERLOAD is
2815    the overload that NON_DEP is calling.  */
2816
2817 tree
2818 build_min_non_dep_op_overload (enum tree_code op,
2819                                tree non_dep,
2820                                tree overload, ...)
2821 {
2822   va_list p;
2823   int nargs, expected_nargs;
2824   tree fn, call;
2825   vec<tree, va_gc> *args;
2826
2827   if (REFERENCE_REF_P (non_dep))
2828     non_dep = TREE_OPERAND (non_dep, 0);
2829
2830   nargs = call_expr_nargs (non_dep);
2831
2832   expected_nargs = cp_tree_code_length (op);
2833   if (op == POSTINCREMENT_EXPR
2834       || op == POSTDECREMENT_EXPR)
2835     expected_nargs += 1;
2836   gcc_assert (nargs == expected_nargs);
2837
2838   args = make_tree_vector ();
2839   va_start (p, overload);
2840
2841   if (TREE_CODE (TREE_TYPE (overload)) == FUNCTION_TYPE)
2842     {
2843       fn = overload;
2844       for (int i = 0; i < nargs; i++)
2845         {
2846           tree arg = va_arg (p, tree);
2847           vec_safe_push (args, arg);
2848         }
2849     }
2850   else if (TREE_CODE (TREE_TYPE (overload)) == METHOD_TYPE)
2851     {
2852       tree object = va_arg (p, tree);
2853       tree binfo = TYPE_BINFO (TREE_TYPE (object));
2854       tree method = build_baselink (binfo, binfo, overload, NULL_TREE);
2855       fn = build_min (COMPONENT_REF, TREE_TYPE (overload),
2856                       object, method, NULL_TREE);
2857       for (int i = 1; i < nargs; i++)
2858         {
2859           tree arg = va_arg (p, tree);
2860           vec_safe_push (args, arg);
2861         }
2862     }
2863   else
2864    gcc_unreachable ();
2865
2866   va_end (p);
2867   call = build_min_non_dep_call_vec (non_dep, fn, args);
2868   release_tree_vector (args);
2869
2870   tree call_expr = call;
2871   if (REFERENCE_REF_P (call_expr))
2872     call_expr = TREE_OPERAND (call_expr, 0);
2873   KOENIG_LOOKUP_P (call_expr) = KOENIG_LOOKUP_P (non_dep);
2874
2875   return call;
2876 }
2877
2878 tree
2879 get_type_decl (tree t)
2880 {
2881   if (TREE_CODE (t) == TYPE_DECL)
2882     return t;
2883   if (TYPE_P (t))
2884     return TYPE_STUB_DECL (t);
2885   gcc_assert (t == error_mark_node);
2886   return t;
2887 }
2888
2889 /* Returns the namespace that contains DECL, whether directly or
2890    indirectly.  */
2891
2892 tree
2893 decl_namespace_context (tree decl)
2894 {
2895   while (1)
2896     {
2897       if (TREE_CODE (decl) == NAMESPACE_DECL)
2898         return decl;
2899       else if (TYPE_P (decl))
2900         decl = CP_DECL_CONTEXT (TYPE_MAIN_DECL (decl));
2901       else
2902         decl = CP_DECL_CONTEXT (decl);
2903     }
2904 }
2905
2906 /* Returns true if decl is within an anonymous namespace, however deeply
2907    nested, or false otherwise.  */
2908
2909 bool
2910 decl_anon_ns_mem_p (const_tree decl)
2911 {
2912   while (1)
2913     {
2914       if (decl == NULL_TREE || decl == error_mark_node)
2915         return false;
2916       if (TREE_CODE (decl) == NAMESPACE_DECL
2917           && DECL_NAME (decl) == NULL_TREE)
2918         return true;
2919       /* Classes and namespaces inside anonymous namespaces have
2920          TREE_PUBLIC == 0, so we can shortcut the search.  */
2921       else if (TYPE_P (decl))
2922         return (TREE_PUBLIC (TYPE_MAIN_DECL (decl)) == 0);
2923       else if (TREE_CODE (decl) == NAMESPACE_DECL)
2924         return (TREE_PUBLIC (decl) == 0);
2925       else
2926         decl = DECL_CONTEXT (decl);
2927     }
2928 }
2929
2930 /* Subroutine of cp_tree_equal: t1 and t2 are the CALL_EXPR_FNs of two
2931    CALL_EXPRS.  Return whether they are equivalent.  */
2932
2933 static bool
2934 called_fns_equal (tree t1, tree t2)
2935 {
2936   /* Core 1321: dependent names are equivalent even if the overload sets
2937      are different.  But do compare explicit template arguments.  */
2938   tree name1 = dependent_name (t1);
2939   tree name2 = dependent_name (t2);
2940   if (name1 || name2)
2941     {
2942       tree targs1 = NULL_TREE, targs2 = NULL_TREE;
2943
2944       if (name1 != name2)
2945         return false;
2946
2947       if (TREE_CODE (t1) == TEMPLATE_ID_EXPR)
2948         targs1 = TREE_OPERAND (t1, 1);
2949       if (TREE_CODE (t2) == TEMPLATE_ID_EXPR)
2950         targs2 = TREE_OPERAND (t2, 1);
2951       return cp_tree_equal (targs1, targs2);
2952     }
2953   else
2954     return cp_tree_equal (t1, t2);
2955 }
2956
2957 /* Return truthvalue of whether T1 is the same tree structure as T2.
2958    Return 1 if they are the same. Return 0 if they are different.  */
2959
2960 bool
2961 cp_tree_equal (tree t1, tree t2)
2962 {
2963   enum tree_code code1, code2;
2964
2965   if (t1 == t2)
2966     return true;
2967   if (!t1 || !t2)
2968     return false;
2969
2970   code1 = TREE_CODE (t1);
2971   code2 = TREE_CODE (t2);
2972
2973   if (code1 != code2)
2974     return false;
2975
2976   switch (code1)
2977     {
2978     case VOID_CST:
2979       /* There's only a single VOID_CST node, so we should never reach
2980          here.  */
2981       gcc_unreachable ();
2982
2983     case INTEGER_CST:
2984       return tree_int_cst_equal (t1, t2);
2985
2986     case REAL_CST:
2987       return real_equal (&TREE_REAL_CST (t1), &TREE_REAL_CST (t2));
2988
2989     case STRING_CST:
2990       return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2991         && !memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2992                     TREE_STRING_LENGTH (t1));
2993
2994     case FIXED_CST:
2995       return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1),
2996                                      TREE_FIXED_CST (t2));
2997
2998     case COMPLEX_CST:
2999       return cp_tree_equal (TREE_REALPART (t1), TREE_REALPART (t2))
3000         && cp_tree_equal (TREE_IMAGPART (t1), TREE_IMAGPART (t2));
3001
3002     case VECTOR_CST:
3003       return operand_equal_p (t1, t2, OEP_ONLY_CONST);
3004
3005     case CONSTRUCTOR:
3006       /* We need to do this when determining whether or not two
3007          non-type pointer to member function template arguments
3008          are the same.  */
3009       if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2))
3010           || CONSTRUCTOR_NELTS (t1) != CONSTRUCTOR_NELTS (t2))
3011         return false;
3012       {
3013         tree field, value;
3014         unsigned int i;
3015         FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (t1), i, field, value)
3016           {
3017             constructor_elt *elt2 = CONSTRUCTOR_ELT (t2, i);
3018             if (!cp_tree_equal (field, elt2->index)
3019                 || !cp_tree_equal (value, elt2->value))
3020               return false;
3021           }
3022       }
3023       return true;
3024
3025     case TREE_LIST:
3026       if (!cp_tree_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2)))
3027         return false;
3028       if (!cp_tree_equal (TREE_VALUE (t1), TREE_VALUE (t2)))
3029         return false;
3030       return cp_tree_equal (TREE_CHAIN (t1), TREE_CHAIN (t2));
3031
3032     case SAVE_EXPR:
3033       return cp_tree_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3034
3035     case CALL_EXPR:
3036       {
3037         tree arg1, arg2;
3038         call_expr_arg_iterator iter1, iter2;
3039         if (!called_fns_equal (CALL_EXPR_FN (t1), CALL_EXPR_FN (t2)))
3040           return false;
3041         for (arg1 = first_call_expr_arg (t1, &iter1),
3042                arg2 = first_call_expr_arg (t2, &iter2);
3043              arg1 && arg2;
3044              arg1 = next_call_expr_arg (&iter1),
3045                arg2 = next_call_expr_arg (&iter2))
3046           if (!cp_tree_equal (arg1, arg2))
3047             return false;
3048         if (arg1 || arg2)
3049           return false;
3050         return true;
3051       }
3052
3053     case TARGET_EXPR:
3054       {
3055         tree o1 = TREE_OPERAND (t1, 0);
3056         tree o2 = TREE_OPERAND (t2, 0);
3057
3058         /* Special case: if either target is an unallocated VAR_DECL,
3059            it means that it's going to be unified with whatever the
3060            TARGET_EXPR is really supposed to initialize, so treat it
3061            as being equivalent to anything.  */
3062         if (VAR_P (o1) && DECL_NAME (o1) == NULL_TREE
3063             && !DECL_RTL_SET_P (o1))
3064           /*Nop*/;
3065         else if (VAR_P (o2) && DECL_NAME (o2) == NULL_TREE
3066                  && !DECL_RTL_SET_P (o2))
3067           /*Nop*/;
3068         else if (!cp_tree_equal (o1, o2))
3069           return false;
3070
3071         return cp_tree_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
3072       }
3073
3074     case WITH_CLEANUP_EXPR:
3075       if (!cp_tree_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)))
3076         return false;
3077       return cp_tree_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t1, 1));
3078
3079     case COMPONENT_REF:
3080       if (TREE_OPERAND (t1, 1) != TREE_OPERAND (t2, 1))
3081         return false;
3082       return cp_tree_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3083
3084     case PARM_DECL:
3085       /* For comparing uses of parameters in late-specified return types
3086          with an out-of-class definition of the function, but can also come
3087          up for expressions that involve 'this' in a member function
3088          template.  */
3089
3090       if (comparing_specializations && !CONSTRAINT_VAR_P (t1))
3091         /* When comparing hash table entries, only an exact match is
3092            good enough; we don't want to replace 'this' with the
3093            version from another function.  But be more flexible
3094            with local parameters in a requires-expression.  */
3095         return false;
3096
3097       if (same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
3098         {
3099           if (DECL_ARTIFICIAL (t1) ^ DECL_ARTIFICIAL (t2))
3100             return false;
3101           if (CONSTRAINT_VAR_P (t1) ^ CONSTRAINT_VAR_P (t2))
3102             return false;
3103           if (DECL_ARTIFICIAL (t1)
3104               || (DECL_PARM_LEVEL (t1) == DECL_PARM_LEVEL (t2)
3105                   && DECL_PARM_INDEX (t1) == DECL_PARM_INDEX (t2)))
3106             return true;
3107         }
3108       return false;
3109
3110     case VAR_DECL:
3111     case CONST_DECL:
3112     case FIELD_DECL:
3113     case FUNCTION_DECL:
3114     case TEMPLATE_DECL:
3115     case IDENTIFIER_NODE:
3116     case SSA_NAME:
3117       return false;
3118
3119     case BASELINK:
3120       return (BASELINK_BINFO (t1) == BASELINK_BINFO (t2)
3121               && BASELINK_ACCESS_BINFO (t1) == BASELINK_ACCESS_BINFO (t2)
3122               && BASELINK_QUALIFIED_P (t1) == BASELINK_QUALIFIED_P (t2)
3123               && cp_tree_equal (BASELINK_FUNCTIONS (t1),
3124                                 BASELINK_FUNCTIONS (t2)));
3125
3126     case TEMPLATE_PARM_INDEX:
3127       return (TEMPLATE_PARM_IDX (t1) == TEMPLATE_PARM_IDX (t2)
3128               && TEMPLATE_PARM_LEVEL (t1) == TEMPLATE_PARM_LEVEL (t2)
3129               && (TEMPLATE_PARM_PARAMETER_PACK (t1)
3130                   == TEMPLATE_PARM_PARAMETER_PACK (t2))
3131               && same_type_p (TREE_TYPE (TEMPLATE_PARM_DECL (t1)),
3132                               TREE_TYPE (TEMPLATE_PARM_DECL (t2))));
3133
3134     case TEMPLATE_ID_EXPR:
3135       return (cp_tree_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
3136               && cp_tree_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
3137
3138     case CONSTRAINT_INFO:
3139       return cp_tree_equal (CI_ASSOCIATED_CONSTRAINTS (t1),
3140                             CI_ASSOCIATED_CONSTRAINTS (t2));
3141
3142     case TREE_VEC:
3143       {
3144         unsigned ix;
3145         if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
3146           return false;
3147         for (ix = TREE_VEC_LENGTH (t1); ix--;)
3148           if (!cp_tree_equal (TREE_VEC_ELT (t1, ix),
3149                               TREE_VEC_ELT (t2, ix)))
3150             return false;
3151         return true;
3152       }
3153
3154     case SIZEOF_EXPR:
3155     case ALIGNOF_EXPR:
3156       {
3157         tree o1 = TREE_OPERAND (t1, 0);
3158         tree o2 = TREE_OPERAND (t2, 0);
3159
3160         if (code1 == SIZEOF_EXPR)
3161           {
3162             if (SIZEOF_EXPR_TYPE_P (t1))
3163               o1 = TREE_TYPE (o1);
3164             if (SIZEOF_EXPR_TYPE_P (t2))
3165               o2 = TREE_TYPE (o2);
3166           }
3167         if (TREE_CODE (o1) != TREE_CODE (o2))
3168           return false;
3169         if (TYPE_P (o1))
3170           return same_type_p (o1, o2);
3171         else
3172           return cp_tree_equal (o1, o2);
3173       }
3174
3175     case MODOP_EXPR:
3176       {
3177         tree t1_op1, t2_op1;
3178
3179         if (!cp_tree_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)))
3180           return false;
3181
3182         t1_op1 = TREE_OPERAND (t1, 1);
3183         t2_op1 = TREE_OPERAND (t2, 1);
3184         if (TREE_CODE (t1_op1) != TREE_CODE (t2_op1))
3185           return false;
3186
3187         return cp_tree_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t2, 2));
3188       }
3189
3190     case PTRMEM_CST:
3191       /* Two pointer-to-members are the same if they point to the same
3192          field or function in the same class.  */
3193       if (PTRMEM_CST_MEMBER (t1) != PTRMEM_CST_MEMBER (t2))
3194         return false;
3195
3196       return same_type_p (PTRMEM_CST_CLASS (t1), PTRMEM_CST_CLASS (t2));
3197
3198     case OVERLOAD:
3199       if (OVL_FUNCTION (t1) != OVL_FUNCTION (t2))
3200         return false;
3201       return cp_tree_equal (OVL_CHAIN (t1), OVL_CHAIN (t2));
3202
3203     case TRAIT_EXPR:
3204       if (TRAIT_EXPR_KIND (t1) != TRAIT_EXPR_KIND (t2))
3205         return false;
3206       return same_type_p (TRAIT_EXPR_TYPE1 (t1), TRAIT_EXPR_TYPE1 (t2))
3207         && cp_tree_equal (TRAIT_EXPR_TYPE2 (t1), TRAIT_EXPR_TYPE2 (t2));
3208
3209     case CAST_EXPR:
3210     case STATIC_CAST_EXPR:
3211     case REINTERPRET_CAST_EXPR:
3212     case CONST_CAST_EXPR:
3213     case DYNAMIC_CAST_EXPR:
3214     case IMPLICIT_CONV_EXPR:
3215     case NEW_EXPR:
3216     CASE_CONVERT:
3217     case NON_LVALUE_EXPR:
3218     case VIEW_CONVERT_EXPR:
3219       if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
3220         return false;
3221       /* Now compare operands as usual.  */
3222       break;
3223
3224     case DEFERRED_NOEXCEPT:
3225       return (cp_tree_equal (DEFERRED_NOEXCEPT_PATTERN (t1),
3226                              DEFERRED_NOEXCEPT_PATTERN (t2))
3227               && comp_template_args (DEFERRED_NOEXCEPT_ARGS (t1),
3228                                      DEFERRED_NOEXCEPT_ARGS (t2)));
3229       break;
3230
3231     default:
3232       break;
3233     }
3234
3235   switch (TREE_CODE_CLASS (code1))
3236     {
3237     case tcc_unary:
3238     case tcc_binary:
3239     case tcc_comparison:
3240     case tcc_expression:
3241     case tcc_vl_exp:
3242     case tcc_reference:
3243     case tcc_statement:
3244       {
3245         int i, n;
3246
3247         n = cp_tree_operand_length (t1);
3248         if (TREE_CODE_CLASS (code1) == tcc_vl_exp
3249             && n != TREE_OPERAND_LENGTH (t2))
3250           return false;
3251
3252         for (i = 0; i < n; ++i)
3253           if (!cp_tree_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i)))
3254             return false;
3255
3256         return true;
3257       }
3258
3259     case tcc_type:
3260       return same_type_p (t1, t2);
3261     default:
3262       gcc_unreachable ();
3263     }
3264   /* We can get here with --disable-checking.  */
3265   return false;
3266 }
3267
3268 /* The type of ARG when used as an lvalue.  */
3269
3270 tree
3271 lvalue_type (tree arg)
3272 {
3273   tree type = TREE_TYPE (arg);
3274   return type;
3275 }
3276
3277 /* The type of ARG for printing error messages; denote lvalues with
3278    reference types.  */
3279
3280 tree
3281 error_type (tree arg)
3282 {
3283   tree type = TREE_TYPE (arg);
3284
3285   if (TREE_CODE (type) == ARRAY_TYPE)
3286     ;
3287   else if (TREE_CODE (type) == ERROR_MARK)
3288     ;
3289   else if (real_lvalue_p (arg))
3290     type = build_reference_type (lvalue_type (arg));
3291   else if (MAYBE_CLASS_TYPE_P (type))
3292     type = lvalue_type (arg);
3293
3294   return type;
3295 }
3296
3297 /* Does FUNCTION use a variable-length argument list?  */
3298
3299 int
3300 varargs_function_p (const_tree function)
3301 {
3302   return stdarg_p (TREE_TYPE (function));
3303 }
3304
3305 /* Returns 1 if decl is a member of a class.  */
3306
3307 int
3308 member_p (const_tree decl)
3309 {
3310   const_tree const ctx = DECL_CONTEXT (decl);
3311   return (ctx && TYPE_P (ctx));
3312 }
3313
3314 /* Create a placeholder for member access where we don't actually have an
3315    object that the access is against.  */
3316
3317 tree
3318 build_dummy_object (tree type)
3319 {
3320   tree decl = build1 (CONVERT_EXPR, build_pointer_type (type), void_node);
3321   return cp_build_indirect_ref (decl, RO_NULL, tf_warning_or_error);
3322 }
3323
3324 /* We've gotten a reference to a member of TYPE.  Return *this if appropriate,
3325    or a dummy object otherwise.  If BINFOP is non-0, it is filled with the
3326    binfo path from current_class_type to TYPE, or 0.  */
3327
3328 tree
3329 maybe_dummy_object (tree type, tree* binfop)
3330 {
3331   tree decl, context;
3332   tree binfo;
3333   tree current = current_nonlambda_class_type ();
3334
3335   if (current
3336       && (binfo = lookup_base (current, type, ba_any, NULL,
3337                                tf_warning_or_error)))
3338     context = current;
3339   else
3340     {
3341       /* Reference from a nested class member function.  */
3342       context = type;
3343       binfo = TYPE_BINFO (type);
3344     }
3345
3346   if (binfop)
3347     *binfop = binfo;
3348
3349   if (current_class_ref
3350       /* current_class_ref might not correspond to current_class_type if
3351          we're in tsubst_default_argument or a lambda-declarator; in either
3352          case, we want to use current_class_ref if it matches CONTEXT.  */
3353       && (same_type_ignoring_top_level_qualifiers_p
3354           (TREE_TYPE (current_class_ref), context)))
3355     decl = current_class_ref;
3356   else
3357     decl = build_dummy_object (context);
3358
3359   return decl;
3360 }
3361
3362 /* Returns 1 if OB is a placeholder object, or a pointer to one.  */
3363
3364 int
3365 is_dummy_object (const_tree ob)
3366 {
3367   if (INDIRECT_REF_P (ob))
3368     ob = TREE_OPERAND (ob, 0);
3369   return (TREE_CODE (ob) == CONVERT_EXPR
3370           && TREE_OPERAND (ob, 0) == void_node);
3371 }
3372
3373 /* Returns 1 iff type T is something we want to treat as a scalar type for
3374    the purpose of deciding whether it is trivial/POD/standard-layout.  */
3375
3376 bool
3377 scalarish_type_p (const_tree t)
3378 {
3379   if (t == error_mark_node)
3380     return 1;
3381
3382   return (SCALAR_TYPE_P (t) || VECTOR_TYPE_P (t));
3383 }
3384
3385 /* Returns true iff T requires non-trivial default initialization.  */
3386
3387 bool
3388 type_has_nontrivial_default_init (const_tree t)
3389 {
3390   t = strip_array_types (CONST_CAST_TREE (t));
3391
3392   if (CLASS_TYPE_P (t))
3393     return TYPE_HAS_COMPLEX_DFLT (t);
3394   else
3395     return 0;
3396 }
3397
3398 /* Returns true iff copying an object of type T (including via move
3399    constructor) is non-trivial.  That is, T has no non-trivial copy
3400    constructors and no non-trivial move constructors.  */
3401
3402 bool
3403 type_has_nontrivial_copy_init (const_tree t)
3404 {
3405   t = strip_array_types (CONST_CAST_TREE (t));
3406
3407   if (CLASS_TYPE_P (t))
3408     {
3409       gcc_assert (COMPLETE_TYPE_P (t));
3410       return ((TYPE_HAS_COPY_CTOR (t)
3411                && TYPE_HAS_COMPLEX_COPY_CTOR (t))
3412               || TYPE_HAS_COMPLEX_MOVE_CTOR (t));
3413     }
3414   else
3415     return 0;
3416 }
3417
3418 /* Returns 1 iff type T is a trivially copyable type, as defined in
3419    [basic.types] and [class].  */
3420
3421 bool
3422 trivially_copyable_p (const_tree t)
3423 {
3424   t = strip_array_types (CONST_CAST_TREE (t));
3425
3426   if (CLASS_TYPE_P (t))
3427     return ((!TYPE_HAS_COPY_CTOR (t)
3428              || !TYPE_HAS_COMPLEX_COPY_CTOR (t))
3429             && !TYPE_HAS_COMPLEX_MOVE_CTOR (t)
3430             && (!TYPE_HAS_COPY_ASSIGN (t)
3431                 || !TYPE_HAS_COMPLEX_COPY_ASSIGN (t))
3432             && !TYPE_HAS_COMPLEX_MOVE_ASSIGN (t)
3433             && TYPE_HAS_TRIVIAL_DESTRUCTOR (t));
3434   else
3435     return !CP_TYPE_VOLATILE_P (t) && scalarish_type_p (t);
3436 }
3437
3438 /* Returns 1 iff type T is a trivial type, as defined in [basic.types] and
3439    [class].  */
3440
3441 bool
3442 trivial_type_p (const_tree t)
3443 {
3444   t = strip_array_types (CONST_CAST_TREE (t));
3445
3446   if (CLASS_TYPE_P (t))
3447     return (TYPE_HAS_TRIVIAL_DFLT (t)
3448             && trivially_copyable_p (t));
3449   else
3450     return scalarish_type_p (t);
3451 }
3452
3453 /* Returns 1 iff type T is a POD type, as defined in [basic.types].  */
3454
3455 bool
3456 pod_type_p (const_tree t)
3457 {
3458   /* This CONST_CAST is okay because strip_array_types returns its
3459      argument unmodified and we assign it to a const_tree.  */
3460   t = strip_array_types (CONST_CAST_TREE(t));
3461
3462   if (!CLASS_TYPE_P (t))
3463     return scalarish_type_p (t);
3464   else if (cxx_dialect > cxx98)
3465     /* [class]/10: A POD struct is a class that is both a trivial class and a
3466        standard-layout class, and has no non-static data members of type
3467        non-POD struct, non-POD union (or array of such types).
3468
3469        We don't need to check individual members because if a member is
3470        non-std-layout or non-trivial, the class will be too.  */
3471     return (std_layout_type_p (t) && trivial_type_p (t));
3472   else
3473     /* The C++98 definition of POD is different.  */
3474     return !CLASSTYPE_NON_LAYOUT_POD_P (t);
3475 }
3476
3477 /* Returns true iff T is POD for the purpose of layout, as defined in the
3478    C++ ABI.  */
3479
3480 bool
3481 layout_pod_type_p (const_tree t)
3482 {
3483   t = strip_array_types (CONST_CAST_TREE (t));
3484
3485   if (CLASS_TYPE_P (t))
3486     return !CLASSTYPE_NON_LAYOUT_POD_P (t);
3487   else
3488     return scalarish_type_p (t);
3489 }
3490
3491 /* Returns true iff T is a standard-layout type, as defined in
3492    [basic.types].  */
3493
3494 bool
3495 std_layout_type_p (const_tree t)
3496 {
3497   t = strip_array_types (CONST_CAST_TREE (t));
3498
3499   if (CLASS_TYPE_P (t))
3500     return !CLASSTYPE_NON_STD_LAYOUT (t);
3501   else
3502     return scalarish_type_p (t);
3503 }
3504
3505 /* Nonzero iff type T is a class template implicit specialization.  */
3506
3507 bool
3508 class_tmpl_impl_spec_p (const_tree t)
3509 {
3510   return CLASS_TYPE_P (t) && CLASSTYPE_TEMPLATE_INSTANTIATION (t);
3511 }
3512
3513 /* Returns 1 iff zero initialization of type T means actually storing
3514    zeros in it.  */
3515
3516 int
3517 zero_init_p (const_tree t)
3518 {
3519   /* This CONST_CAST is okay because strip_array_types returns its
3520      argument unmodified and we assign it to a const_tree.  */
3521   t = strip_array_types (CONST_CAST_TREE(t));
3522
3523   if (t == error_mark_node)
3524     return 1;
3525
3526   /* NULL pointers to data members are initialized with -1.  */
3527   if (TYPE_PTRDATAMEM_P (t))
3528     return 0;
3529
3530   /* Classes that contain types that can't be zero-initialized, cannot
3531      be zero-initialized themselves.  */
3532   if (CLASS_TYPE_P (t) && CLASSTYPE_NON_ZERO_INIT_P (t))
3533     return 0;
3534
3535   return 1;
3536 }
3537
3538 /* Table of valid C++ attributes.  */
3539 const struct attribute_spec cxx_attribute_table[] =
3540 {
3541   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler,
3542        affects_type_identity } */
3543   { "java_interface", 0, 0, false, false, false,
3544     handle_java_interface_attribute, false },
3545   { "com_interface",  0, 0, false, false, false,
3546     handle_com_interface_attribute, false },
3547   { "init_priority",  1, 1, true,  false, false,
3548     handle_init_priority_attribute, false },
3549   { "abi_tag", 1, -1, false, false, false,
3550     handle_abi_tag_attribute, true },
3551   { NULL,             0, 0, false, false, false, NULL, false }
3552 };
3553
3554 /* Handle a "java_interface" attribute; arguments as in
3555    struct attribute_spec.handler.  */
3556 static tree
3557 handle_java_interface_attribute (tree* node,
3558                                  tree name,
3559                                  tree /*args*/,
3560                                  int flags,
3561                                  bool* no_add_attrs)
3562 {
3563   if (DECL_P (*node)
3564       || !CLASS_TYPE_P (*node)
3565       || !TYPE_FOR_JAVA (*node))
3566     {
3567       error ("%qE attribute can only be applied to Java class definitions",
3568              name);
3569       *no_add_attrs = true;
3570       return NULL_TREE;
3571     }
3572   if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
3573     *node = build_variant_type_copy (*node);
3574   TYPE_JAVA_INTERFACE (*node) = 1;
3575
3576   return NULL_TREE;
3577 }
3578
3579 /* Handle a "com_interface" attribute; arguments as in
3580    struct attribute_spec.handler.  */
3581 static tree
3582 handle_com_interface_attribute (tree* node,
3583                                 tree name,
3584                                 tree /*args*/,
3585                                 int /*flags*/,
3586                                 bool* no_add_attrs)
3587 {
3588   static int warned;
3589
3590   *no_add_attrs = true;
3591
3592   if (DECL_P (*node)
3593       || !CLASS_TYPE_P (*node)
3594       || *node != TYPE_MAIN_VARIANT (*node))
3595     {
3596       warning (OPT_Wattributes, "%qE attribute can only be applied "
3597                "to class definitions", name);
3598       return NULL_TREE;
3599     }
3600
3601   if (!warned++)
3602     warning (0, "%qE is obsolete; g++ vtables are now COM-compatible by default",
3603              name);
3604
3605   return NULL_TREE;
3606 }
3607
3608 /* Handle an "init_priority" attribute; arguments as in
3609    struct attribute_spec.handler.  */
3610 static tree
3611 handle_init_priority_attribute (tree* node,
3612                                 tree name,
3613                                 tree args,
3614                                 int /*flags*/,
3615                                 bool* no_add_attrs)
3616 {
3617   tree initp_expr = TREE_VALUE (args);
3618   tree decl = *node;
3619   tree type = TREE_TYPE (decl);
3620   int pri;
3621
3622   STRIP_NOPS (initp_expr);
3623   initp_expr = default_conversion (initp_expr);
3624   if (initp_expr)
3625     initp_expr = maybe_constant_value (initp_expr);
3626
3627   if (!initp_expr || TREE_CODE (initp_expr) != INTEGER_CST)
3628     {
3629       error ("requested init_priority is not an integer constant");
3630       cxx_constant_value (initp_expr);
3631       *no_add_attrs = true;
3632       return NULL_TREE;
3633     }
3634
3635   pri = TREE_INT_CST_LOW (initp_expr);
3636
3637   type = strip_array_types (type);
3638
3639   if (decl == NULL_TREE
3640       || !VAR_P (decl)
3641       || !TREE_STATIC (decl)
3642       || DECL_EXTERNAL (decl)
3643       || (TREE_CODE (type) != RECORD_TYPE
3644           && TREE_CODE (type) != UNION_TYPE)
3645       /* Static objects in functions are initialized the
3646          first time control passes through that
3647          function. This is not precise enough to pin down an
3648          init_priority value, so don't allow it.  */
3649       || current_function_decl)
3650     {
3651       error ("can only use %qE attribute on file-scope definitions "
3652              "of objects of class type", name);
3653       *no_add_attrs = true;
3654       return NULL_TREE;
3655     }
3656
3657   if (pri > MAX_INIT_PRIORITY || pri <= 0)
3658     {
3659       error ("requested init_priority is out of range");
3660       *no_add_attrs = true;
3661       return NULL_TREE;
3662     }
3663
3664   /* Check for init_priorities that are reserved for
3665      language and runtime support implementations.*/
3666   if (pri <= MAX_RESERVED_INIT_PRIORITY)
3667     {
3668       warning
3669         (0, "requested init_priority is reserved for internal use");
3670     }
3671
3672   if (SUPPORTS_INIT_PRIORITY)
3673     {
3674       SET_DECL_INIT_PRIORITY (decl, pri);
3675       DECL_HAS_INIT_PRIORITY_P (decl) = 1;
3676       return NULL_TREE;
3677     }
3678   else
3679     {
3680       error ("%qE attribute is not supported on this platform", name);
3681       *no_add_attrs = true;
3682       return NULL_TREE;
3683     }
3684 }
3685
3686 /* DECL is being redeclared; the old declaration had the abi tags in OLD,
3687    and the new one has the tags in NEW_.  Give an error if there are tags
3688    in NEW_ that weren't in OLD.  */
3689
3690 bool
3691 check_abi_tag_redeclaration (const_tree decl, const_tree old, const_tree new_)
3692 {
3693   if (old && TREE_CODE (TREE_VALUE (old)) == TREE_LIST)
3694     old = TREE_VALUE (old);
3695   if (new_ && TREE_CODE (TREE_VALUE (new_)) == TREE_LIST)
3696     new_ = TREE_VALUE (new_);
3697   bool err = false;
3698   for (const_tree t = new_; t; t = TREE_CHAIN (t))
3699     {
3700       tree str = TREE_VALUE (t);
3701       for (const_tree in = old; in; in = TREE_CHAIN (in))
3702         {
3703           tree ostr = TREE_VALUE (in);
3704           if (cp_tree_equal (str, ostr))
3705             goto found;
3706         }
3707       error ("redeclaration of %qD adds abi tag %E", decl, str);
3708       err = true;
3709     found:;
3710     }
3711   if (err)
3712     {
3713       inform (DECL_SOURCE_LOCATION (decl), "previous declaration here");
3714       return false;
3715     }
3716   return true;
3717 }
3718
3719 /* The abi_tag attribute with the name NAME was given ARGS.  If they are
3720    ill-formed, give an error and return false; otherwise, return true.  */
3721
3722 bool
3723 check_abi_tag_args (tree args, tree name)
3724 {
3725   if (!args)
3726     {
3727       error ("the %qE attribute requires arguments", name);
3728       return false;
3729     }
3730   for (tree arg = args; arg; arg = TREE_CHAIN (arg))
3731     {
3732       tree elt = TREE_VALUE (arg);
3733       if (TREE_CODE (elt) != STRING_CST
3734           || (!same_type_ignoring_top_level_qualifiers_p
3735               (strip_array_types (TREE_TYPE (elt)),
3736                char_type_node)))
3737         {
3738           error ("arguments to the %qE attribute must be narrow string "
3739                  "literals", name);
3740           return false;
3741         }
3742       const char *begin = TREE_STRING_POINTER (elt);
3743       const char *end = begin + TREE_STRING_LENGTH (elt);
3744       for (const char *p = begin; p != end; ++p)
3745         {
3746           char c = *p;
3747           if (p == begin)
3748             {
3749               if (!ISALPHA (c) && c != '_')
3750                 {
3751                   error ("arguments to the %qE attribute must contain valid "
3752                          "identifiers", name);
3753                   inform (input_location, "%<%c%> is not a valid first "
3754                           "character for an identifier", c);
3755                   return false;
3756                 }
3757             }
3758           else if (p == end - 1)
3759             gcc_assert (c == 0);
3760           else
3761             {
3762               if (!ISALNUM (c) && c != '_')
3763                 {
3764                   error ("arguments to the %qE attribute must contain valid "
3765                          "identifiers", name);
3766                   inform (input_location, "%<%c%> is not a valid character "
3767                           "in an identifier", c);
3768                   return false;
3769                 }
3770             }
3771         }
3772     }
3773   return true;
3774 }
3775
3776 /* Handle an "abi_tag" attribute; arguments as in
3777    struct attribute_spec.handler.  */
3778
3779 static tree
3780 handle_abi_tag_attribute (tree* node, tree name, tree args,
3781                           int flags, bool* no_add_attrs)
3782 {
3783   if (!check_abi_tag_args (args, name))
3784     goto fail;
3785
3786   if (TYPE_P (*node))
3787     {
3788       if (!OVERLOAD_TYPE_P (*node))
3789         {
3790           error ("%qE attribute applied to non-class, non-enum type %qT",
3791                  name, *node);
3792           goto fail;
3793         }
3794       else if (!(flags & (int)ATTR_FLAG_TYPE_IN_PLACE))
3795         {
3796           error ("%qE attribute applied to %qT after its definition",
3797                  name, *node);
3798           goto fail;
3799         }
3800       else if (CLASS_TYPE_P (*node)
3801                && CLASSTYPE_TEMPLATE_INSTANTIATION (*node))
3802         {
3803           warning (OPT_Wattributes, "ignoring %qE attribute applied to "
3804                    "template instantiation %qT", name, *node);
3805           goto fail;
3806         }
3807       else if (CLASS_TYPE_P (*node)
3808                && CLASSTYPE_TEMPLATE_SPECIALIZATION (*node))
3809         {
3810           warning (OPT_Wattributes, "ignoring %qE attribute applied to "
3811                    "template specialization %qT", name, *node);
3812           goto fail;
3813         }
3814
3815       tree attributes = TYPE_ATTRIBUTES (*node);
3816       tree decl = TYPE_NAME (*node);
3817
3818       /* Make sure all declarations have the same abi tags.  */
3819       if (DECL_SOURCE_LOCATION (decl) != input_location)
3820         {
3821           if (!check_abi_tag_redeclaration (decl,
3822                                             lookup_attribute ("abi_tag",
3823                                                               attributes),
3824                                             args))
3825             goto fail;
3826         }
3827     }
3828   else
3829     {
3830       if (!VAR_OR_FUNCTION_DECL_P (*node))
3831         {
3832           error ("%qE attribute applied to non-function, non-variable %qD",
3833                  name, *node);
3834           goto fail;
3835         }
3836       else if (DECL_LANGUAGE (*node) == lang_c)
3837         {
3838           error ("%qE attribute applied to extern \"C\" declaration %qD",
3839                  name, *node);
3840           goto fail;
3841         }
3842     }
3843
3844   return NULL_TREE;
3845
3846  fail:
3847   *no_add_attrs = true;
3848   return NULL_TREE;
3849 }
3850
3851 /* Return a new PTRMEM_CST of the indicated TYPE.  The MEMBER is the
3852    thing pointed to by the constant.  */
3853
3854 tree
3855 make_ptrmem_cst (tree type, tree member)
3856 {
3857   tree ptrmem_cst = make_node (PTRMEM_CST);
3858   TREE_TYPE (ptrmem_cst) = type;
3859   PTRMEM_CST_MEMBER (ptrmem_cst) = member;
3860   return ptrmem_cst;
3861 }
3862
3863 /* Build a variant of TYPE that has the indicated ATTRIBUTES.  May
3864    return an existing type if an appropriate type already exists.  */
3865
3866 tree
3867 cp_build_type_attribute_variant (tree type, tree attributes)
3868 {
3869   tree new_type;
3870
3871   new_type = build_type_attribute_variant (type, attributes);
3872   if (TREE_CODE (new_type) == FUNCTION_TYPE
3873       || TREE_CODE (new_type) == METHOD_TYPE)
3874     {
3875       new_type = build_exception_variant (new_type,
3876                                           TYPE_RAISES_EXCEPTIONS (type));
3877       new_type = build_ref_qualified_type (new_type,
3878                                            type_memfn_rqual (type));
3879     }
3880
3881   /* Making a new main variant of a class type is broken.  */
3882   gcc_assert (!CLASS_TYPE_P (type) || new_type == type);
3883
3884   return new_type;
3885 }
3886
3887 /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
3888    Called only after doing all language independent checks.  Only
3889    to check TYPE_RAISES_EXCEPTIONS for FUNCTION_TYPE, the rest is already
3890    compared in type_hash_eq.  */
3891
3892 bool
3893 cxx_type_hash_eq (const_tree typea, const_tree typeb)
3894 {
3895   gcc_assert (TREE_CODE (typea) == FUNCTION_TYPE
3896               || TREE_CODE (typea) == METHOD_TYPE);
3897
3898   return comp_except_specs (TYPE_RAISES_EXCEPTIONS (typea),
3899                             TYPE_RAISES_EXCEPTIONS (typeb), ce_exact);
3900 }
3901
3902 /* Apply FUNC to all language-specific sub-trees of TP in a pre-order
3903    traversal.  Called from walk_tree.  */
3904
3905 tree
3906 cp_walk_subtrees (tree *tp, int *walk_subtrees_p, walk_tree_fn func,
3907                   void *data, hash_set<tree> *pset)
3908 {
3909   enum tree_code code = TREE_CODE (*tp);
3910   tree result;
3911
3912 #define WALK_SUBTREE(NODE)                              \
3913   do                                                    \
3914     {                                                   \
3915       result = cp_walk_tree (&(NODE), func, data, pset);        \
3916       if (result) goto out;                             \
3917     }                                                   \
3918   while (0)
3919
3920   /* Not one of the easy cases.  We must explicitly go through the
3921      children.  */
3922   result = NULL_TREE;
3923   switch (code)
3924     {
3925     case DEFAULT_ARG:
3926     case TEMPLATE_TEMPLATE_PARM:
3927     case BOUND_TEMPLATE_TEMPLATE_PARM:
3928     case UNBOUND_CLASS_TEMPLATE:
3929     case TEMPLATE_PARM_INDEX:
3930     case TEMPLATE_TYPE_PARM:
3931     case TYPENAME_TYPE:
3932     case TYPEOF_TYPE:
3933     case UNDERLYING_TYPE:
3934       /* None of these have subtrees other than those already walked
3935          above.  */
3936       *walk_subtrees_p = 0;
3937       break;
3938
3939     case BASELINK:
3940       WALK_SUBTREE (BASELINK_FUNCTIONS (*tp));
3941       *walk_subtrees_p = 0;
3942       break;
3943
3944     case PTRMEM_CST:
3945       WALK_SUBTREE (TREE_TYPE (*tp));
3946       *walk_subtrees_p = 0;
3947       break;
3948
3949     case TREE_LIST:
3950       WALK_SUBTREE (TREE_PURPOSE (*tp));
3951       break;
3952
3953     case OVERLOAD:
3954       WALK_SUBTREE (OVL_FUNCTION (*tp));
3955       WALK_SUBTREE (OVL_CHAIN (*tp));
3956       *walk_subtrees_p = 0;
3957       break;
3958
3959     case USING_DECL:
3960       WALK_SUBTREE (DECL_NAME (*tp));
3961       WALK_SUBTREE (USING_DECL_SCOPE (*tp));
3962       WALK_SUBTREE (USING_DECL_DECLS (*tp));
3963       *walk_subtrees_p = 0;
3964       break;
3965
3966     case RECORD_TYPE:
3967       if (TYPE_PTRMEMFUNC_P (*tp))
3968         WALK_SUBTREE (TYPE_PTRMEMFUNC_FN_TYPE_RAW (*tp));
3969       break;
3970
3971     case TYPE_ARGUMENT_PACK:
3972     case NONTYPE_ARGUMENT_PACK:
3973       {
3974         tree args = ARGUMENT_PACK_ARGS (*tp);
3975         int i, len = TREE_VEC_LENGTH (args);
3976         for (i = 0; i < len; i++)
3977           WALK_SUBTREE (TREE_VEC_ELT (args, i));
3978       }
3979       break;
3980
3981     case TYPE_PACK_EXPANSION:
3982       WALK_SUBTREE (TREE_TYPE (*tp));
3983       WALK_SUBTREE (PACK_EXPANSION_EXTRA_ARGS (*tp));
3984       *walk_subtrees_p = 0;
3985       break;
3986
3987     case EXPR_PACK_EXPANSION:
3988       WALK_SUBTREE (TREE_OPERAND (*tp, 0));
3989       WALK_SUBTREE (PACK_EXPANSION_EXTRA_ARGS (*tp));
3990       *walk_subtrees_p = 0;
3991       break;
3992
3993     case CAST_EXPR:
3994     case REINTERPRET_CAST_EXPR:
3995     case STATIC_CAST_EXPR:
3996     case CONST_CAST_EXPR:
3997     case DYNAMIC_CAST_EXPR:
3998     case IMPLICIT_CONV_EXPR:
3999       if (TREE_TYPE (*tp))
4000         WALK_SUBTREE (TREE_TYPE (*tp));
4001
4002       {
4003         int i;
4004         for (i = 0; i < TREE_CODE_LENGTH (TREE_CODE (*tp)); ++i)
4005           WALK_SUBTREE (TREE_OPERAND (*tp, i));
4006       }
4007       *walk_subtrees_p = 0;
4008       break;
4009
4010     case TRAIT_EXPR:
4011       WALK_SUBTREE (TRAIT_EXPR_TYPE1 (*tp));
4012       WALK_SUBTREE (TRAIT_EXPR_TYPE2 (*tp));
4013       *walk_subtrees_p = 0;
4014       break;
4015
4016     case DECLTYPE_TYPE:
4017       WALK_SUBTREE (DECLTYPE_TYPE_EXPR (*tp));
4018       *walk_subtrees_p = 0;
4019       break;
4020
4021     case REQUIRES_EXPR:
4022       // Only recurse through the nested expression. Do not
4023       // walk the parameter list. Doing so causes false
4024       // positives in the pack expansion checker since the
4025       // requires parameters are introduced as pack expansions.
4026       WALK_SUBTREE (TREE_OPERAND (*tp, 1));
4027       *walk_subtrees_p = 0;
4028       break;
4029
4030     default:
4031       return NULL_TREE;
4032     }
4033
4034   /* We didn't find what we were looking for.  */
4035  out:
4036   return result;
4037
4038 #undef WALK_SUBTREE
4039 }
4040
4041 /* Like save_expr, but for C++.  */
4042
4043 tree
4044 cp_save_expr (tree expr)
4045 {
4046   /* There is no reason to create a SAVE_EXPR within a template; if
4047      needed, we can create the SAVE_EXPR when instantiating the
4048      template.  Furthermore, the middle-end cannot handle C++-specific
4049      tree codes.  */
4050   if (processing_template_decl)
4051     return expr;
4052   return save_expr (expr);
4053 }
4054
4055 /* Initialize tree.c.  */
4056
4057 void
4058 init_tree (void)
4059 {
4060   list_hash_table = hash_table<list_hasher>::create_ggc (61);
4061 }
4062
4063 /* Returns the kind of special function that DECL (a FUNCTION_DECL)
4064    is.  Note that sfk_none is zero, so this function can be used as a
4065    predicate to test whether or not DECL is a special function.  */
4066
4067 special_function_kind
4068 special_function_p (const_tree decl)
4069 {
4070   /* Rather than doing all this stuff with magic names, we should
4071      probably have a field of type `special_function_kind' in
4072      DECL_LANG_SPECIFIC.  */
4073   if (DECL_INHERITED_CTOR_BASE (decl))
4074     return sfk_inheriting_constructor;
4075   if (DECL_COPY_CONSTRUCTOR_P (decl))
4076     return sfk_copy_constructor;
4077   if (DECL_MOVE_CONSTRUCTOR_P (decl))
4078     return sfk_move_constructor;
4079   if (DECL_CONSTRUCTOR_P (decl))
4080     return sfk_constructor;
4081   if (DECL_OVERLOADED_OPERATOR_P (decl) == NOP_EXPR)
4082     {
4083       if (copy_fn_p (decl))
4084         return sfk_copy_assignment;
4085       if (move_fn_p (decl))
4086         return sfk_move_assignment;
4087     }
4088   if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (decl))
4089     return sfk_destructor;
4090   if (DECL_COMPLETE_DESTRUCTOR_P (decl))
4091     return sfk_complete_destructor;
4092   if (DECL_BASE_DESTRUCTOR_P (decl))
4093     return sfk_base_destructor;
4094   if (DECL_DELETING_DESTRUCTOR_P (decl))
4095     return sfk_deleting_destructor;
4096   if (DECL_CONV_FN_P (decl))
4097     return sfk_conversion;
4098
4099   return sfk_none;
4100 }
4101
4102 /* Returns nonzero if TYPE is a character type, including wchar_t.  */
4103
4104 int
4105 char_type_p (tree type)
4106 {
4107   return (same_type_p (type, char_type_node)
4108           || same_type_p (type, unsigned_char_type_node)
4109           || same_type_p (type, signed_char_type_node)
4110           || same_type_p (type, char16_type_node)
4111           || same_type_p (type, char32_type_node)
4112           || same_type_p (type, wchar_type_node));
4113 }
4114
4115 /* Returns the kind of linkage associated with the indicated DECL.  Th
4116    value returned is as specified by the language standard; it is
4117    independent of implementation details regarding template
4118    instantiation, etc.  For example, it is possible that a declaration
4119    to which this function assigns external linkage would not show up
4120    as a global symbol when you run `nm' on the resulting object file.  */
4121
4122 linkage_kind
4123 decl_linkage (tree decl)
4124 {
4125   /* This function doesn't attempt to calculate the linkage from first
4126      principles as given in [basic.link].  Instead, it makes use of
4127      the fact that we have already set TREE_PUBLIC appropriately, and
4128      then handles a few special cases.  Ideally, we would calculate
4129      linkage first, and then transform that into a concrete
4130      implementation.  */
4131
4132   /* Things that don't have names have no linkage.  */
4133   if (!DECL_NAME (decl))
4134     return lk_none;
4135
4136   /* Fields have no linkage.  */
4137   if (TREE_CODE (decl) == FIELD_DECL)
4138     return lk_none;
4139
4140   /* Things that are TREE_PUBLIC have external linkage.  */
4141   if (TREE_PUBLIC (decl))
4142     return lk_external;
4143
4144   if (TREE_CODE (decl) == NAMESPACE_DECL)
4145     return lk_external;
4146
4147   /* Linkage of a CONST_DECL depends on the linkage of the enumeration
4148      type.  */
4149   if (TREE_CODE (decl) == CONST_DECL)
4150     return decl_linkage (TYPE_NAME (DECL_CONTEXT (decl)));
4151
4152   /* Things in local scope do not have linkage, if they don't have
4153      TREE_PUBLIC set.  */
4154   if (decl_function_context (decl))
4155     return lk_none;
4156
4157   /* Members of the anonymous namespace also have TREE_PUBLIC unset, but
4158      are considered to have external linkage for language purposes, as do
4159      template instantiations on targets without weak symbols.  DECLs really
4160      meant to have internal linkage have DECL_THIS_STATIC set.  */
4161   if (TREE_CODE (decl) == TYPE_DECL)
4162     return lk_external;
4163   if (VAR_OR_FUNCTION_DECL_P (decl))
4164     {
4165       if (!DECL_THIS_STATIC (decl))
4166         return lk_external;
4167
4168       /* Static data members and static member functions from classes
4169          in anonymous namespace also don't have TREE_PUBLIC set.  */
4170       if (DECL_CLASS_CONTEXT (decl))
4171         return lk_external;
4172     }
4173
4174   /* Everything else has internal linkage.  */
4175   return lk_internal;
4176 }
4177
4178 /* Returns the storage duration of the object or reference associated with
4179    the indicated DECL, which should be a VAR_DECL or PARM_DECL.  */
4180
4181 duration_kind
4182 decl_storage_duration (tree decl)
4183 {
4184   if (TREE_CODE (decl) == PARM_DECL)
4185     return dk_auto;
4186   if (TREE_CODE (decl) == FUNCTION_DECL)
4187     return dk_static;
4188   gcc_assert (VAR_P (decl));
4189   if (!TREE_STATIC (decl)
4190       && !DECL_EXTERNAL (decl))
4191     return dk_auto;
4192   if (CP_DECL_THREAD_LOCAL_P (decl))
4193     return dk_thread;
4194   return dk_static;
4195 }
4196 \f
4197 /* EXP is an expression that we want to pre-evaluate.  Returns (in
4198    *INITP) an expression that will perform the pre-evaluation.  The
4199    value returned by this function is a side-effect free expression
4200    equivalent to the pre-evaluated expression.  Callers must ensure
4201    that *INITP is evaluated before EXP.  */
4202
4203 tree
4204 stabilize_expr (tree exp, tree* initp)
4205 {
4206   tree init_expr;
4207
4208   if (!TREE_SIDE_EFFECTS (exp))
4209     init_expr = NULL_TREE;
4210   else if (VOID_TYPE_P (TREE_TYPE (exp)))
4211     {
4212       init_expr = exp;
4213       exp = void_node;
4214     }
4215   /* There are no expressions with REFERENCE_TYPE, but there can be call
4216      arguments with such a type; just treat it as a pointer.  */
4217   else if (TREE_CODE (TREE_TYPE (exp)) == REFERENCE_TYPE
4218            || SCALAR_TYPE_P (TREE_TYPE (exp))
4219            || !lvalue_or_rvalue_with_address_p (exp))
4220     {
4221       init_expr = get_target_expr (exp);
4222       exp = TARGET_EXPR_SLOT (init_expr);
4223       if (CLASS_TYPE_P (TREE_TYPE (exp)))
4224         exp = move (exp);
4225       else
4226         exp = rvalue (exp);
4227     }
4228   else
4229     {
4230       bool xval = !real_lvalue_p (exp);
4231       exp = cp_build_addr_expr (exp, tf_warning_or_error);
4232       init_expr = get_target_expr (exp);
4233       exp = TARGET_EXPR_SLOT (init_expr);
4234       exp = cp_build_indirect_ref (exp, RO_NULL, tf_warning_or_error);
4235       if (xval)
4236         exp = move (exp);
4237     }
4238   *initp = init_expr;
4239
4240   gcc_assert (!TREE_SIDE_EFFECTS (exp));
4241   return exp;
4242 }
4243
4244 /* Add NEW_EXPR, an expression whose value we don't care about, after the
4245    similar expression ORIG.  */
4246
4247 tree
4248 add_stmt_to_compound (tree orig, tree new_expr)
4249 {
4250   if (!new_expr || !TREE_SIDE_EFFECTS (new_expr))
4251     return orig;
4252   if (!orig || !TREE_SIDE_EFFECTS (orig))
4253     return new_expr;
4254   return build2 (COMPOUND_EXPR, void_type_node, orig, new_expr);
4255 }
4256
4257 /* Like stabilize_expr, but for a call whose arguments we want to
4258    pre-evaluate.  CALL is modified in place to use the pre-evaluated
4259    arguments, while, upon return, *INITP contains an expression to
4260    compute the arguments.  */
4261
4262 void
4263 stabilize_call (tree call, tree *initp)
4264 {
4265   tree inits = NULL_TREE;
4266   int i;
4267   int nargs = call_expr_nargs (call);
4268
4269   if (call == error_mark_node || processing_template_decl)
4270     {
4271       *initp = NULL_TREE;
4272       return;
4273     }
4274
4275   gcc_assert (TREE_CODE (call) == CALL_EXPR);
4276
4277   for (i = 0; i < nargs; i++)
4278     {
4279       tree init;
4280       CALL_EXPR_ARG (call, i) =
4281         stabilize_expr (CALL_EXPR_ARG (call, i), &init);
4282       inits = add_stmt_to_compound (inits, init);
4283     }
4284
4285   *initp = inits;
4286 }
4287
4288 /* Like stabilize_expr, but for an AGGR_INIT_EXPR whose arguments we want
4289    to pre-evaluate.  CALL is modified in place to use the pre-evaluated
4290    arguments, while, upon return, *INITP contains an expression to
4291    compute the arguments.  */
4292
4293 static void
4294 stabilize_aggr_init (tree call, tree *initp)
4295 {
4296   tree inits = NULL_TREE;
4297   int i;
4298   int nargs = aggr_init_expr_nargs (call);
4299
4300   if (call == error_mark_node)
4301     return;
4302
4303   gcc_assert (TREE_CODE (call) == AGGR_INIT_EXPR);
4304
4305   for (i = 0; i < nargs; i++)
4306     {
4307       tree init;
4308       AGGR_INIT_EXPR_ARG (call, i) =
4309         stabilize_expr (AGGR_INIT_EXPR_ARG (call, i), &init);
4310       inits = add_stmt_to_compound (inits, init);
4311     }
4312
4313   *initp = inits;
4314 }
4315
4316 /* Like stabilize_expr, but for an initialization.
4317
4318    If the initialization is for an object of class type, this function
4319    takes care not to introduce additional temporaries.
4320
4321    Returns TRUE iff the expression was successfully pre-evaluated,
4322    i.e., if INIT is now side-effect free, except for, possibly, a
4323    single call to a constructor.  */
4324
4325 bool
4326 stabilize_init (tree init, tree *initp)
4327 {
4328   tree t = init;
4329
4330   *initp = NULL_TREE;
4331
4332   if (t == error_mark_node || processing_template_decl)
4333     return true;
4334
4335   if (TREE_CODE (t) == INIT_EXPR)
4336     t = TREE_OPERAND (t, 1);
4337   if (TREE_CODE (t) == TARGET_EXPR)
4338     t = TARGET_EXPR_INITIAL (t);
4339
4340   /* If the RHS can be stabilized without breaking copy elision, stabilize
4341      it.  We specifically don't stabilize class prvalues here because that
4342      would mean an extra copy, but they might be stabilized below.  */
4343   if (TREE_CODE (init) == INIT_EXPR
4344       && TREE_CODE (t) != CONSTRUCTOR
4345       && TREE_CODE (t) != AGGR_INIT_EXPR
4346       && (SCALAR_TYPE_P (TREE_TYPE (t))
4347           || lvalue_or_rvalue_with_address_p (t)))
4348     {
4349       TREE_OPERAND (init, 1) = stabilize_expr (t, initp);
4350       return true;
4351     }
4352
4353   if (TREE_CODE (t) == COMPOUND_EXPR
4354       && TREE_CODE (init) == INIT_EXPR)
4355     {
4356       tree last = expr_last (t);
4357       /* Handle stabilizing the EMPTY_CLASS_EXPR pattern.  */
4358       if (!TREE_SIDE_EFFECTS (last))
4359         {
4360           *initp = t;
4361           TREE_OPERAND (init, 1) = last;
4362           return true;
4363         }
4364     }
4365
4366   if (TREE_CODE (t) == CONSTRUCTOR)
4367     {
4368       /* Aggregate initialization: stabilize each of the field
4369          initializers.  */
4370       unsigned i;
4371       constructor_elt *ce;
4372       bool good = true;
4373       vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t);
4374       for (i = 0; vec_safe_iterate (v, i, &ce); ++i)
4375         {
4376           tree type = TREE_TYPE (ce->value);
4377           tree subinit;
4378           if (TREE_CODE (type) == REFERENCE_TYPE
4379               || SCALAR_TYPE_P (type))
4380             ce->value = stabilize_expr (ce->value, &subinit);
4381           else if (!stabilize_init (ce->value, &subinit))
4382             good = false;
4383           *initp = add_stmt_to_compound (*initp, subinit);
4384         }
4385       return good;
4386     }
4387
4388   if (TREE_CODE (t) == CALL_EXPR)
4389     {
4390       stabilize_call (t, initp);
4391       return true;
4392     }
4393
4394   if (TREE_CODE (t) == AGGR_INIT_EXPR)
4395     {
4396       stabilize_aggr_init (t, initp);
4397       return true;
4398     }
4399
4400   /* The initialization is being performed via a bitwise copy -- and
4401      the item copied may have side effects.  */
4402   return !TREE_SIDE_EFFECTS (init);
4403 }
4404
4405 /* Returns true if a cast to TYPE may appear in an integral constant
4406    expression.  */
4407
4408 bool
4409 cast_valid_in_integral_constant_expression_p (tree type)
4410 {
4411   return (INTEGRAL_OR_ENUMERATION_TYPE_P (type)
4412           || cxx_dialect >= cxx11
4413           || dependent_type_p (type)
4414           || type == error_mark_node);
4415 }
4416
4417 /* Return true if we need to fix linkage information of DECL.  */
4418
4419 static bool
4420 cp_fix_function_decl_p (tree decl)
4421 {
4422   /* Skip if DECL is not externally visible.  */
4423   if (!TREE_PUBLIC (decl))
4424     return false;
4425
4426   /* We need to fix DECL if it a appears to be exported but with no
4427      function body.  Thunks do not have CFGs and we may need to
4428      handle them specially later.   */
4429   if (!gimple_has_body_p (decl)
4430       && !DECL_THUNK_P (decl)
4431       && !DECL_EXTERNAL (decl))
4432     {
4433       struct cgraph_node *node = cgraph_node::get (decl);
4434
4435       /* Don't fix same_body aliases.  Although they don't have their own
4436          CFG, they share it with what they alias to.  */
4437       if (!node || !node->alias
4438           || !vec_safe_length (node->ref_list.references))
4439         return true;
4440     }
4441
4442   return false;
4443 }
4444
4445 /* Clean the C++ specific parts of the tree T. */
4446
4447 void
4448 cp_free_lang_data (tree t)
4449 {
4450   if (TREE_CODE (t) == METHOD_TYPE
4451       || TREE_CODE (t) == FUNCTION_TYPE)
4452     {
4453       /* Default args are not interesting anymore.  */
4454       tree argtypes = TYPE_ARG_TYPES (t);
4455       while (argtypes)
4456         {
4457           TREE_PURPOSE (argtypes) = 0;
4458           argtypes = TREE_CHAIN (argtypes);
4459         }
4460     }
4461   else if (TREE_CODE (t) == FUNCTION_DECL
4462            && cp_fix_function_decl_p (t))
4463     {
4464       /* If T is used in this translation unit at all,  the definition
4465          must exist somewhere else since we have decided to not emit it
4466          in this TU.  So make it an external reference.  */
4467       DECL_EXTERNAL (t) = 1;
4468       TREE_STATIC (t) = 0;
4469     }
4470   if (TREE_CODE (t) == NAMESPACE_DECL)
4471     {
4472       /* The list of users of a namespace isn't useful for the middle-end
4473          or debug generators.  */
4474       DECL_NAMESPACE_USERS (t) = NULL_TREE;
4475       /* Neither do we need the leftover chaining of namespaces
4476          from the binding level.  */
4477       DECL_CHAIN (t) = NULL_TREE;
4478     }
4479 }
4480
4481 /* Stub for c-common.  Please keep in sync with c-decl.c.
4482    FIXME: If address space support is target specific, then this
4483    should be a C target hook.  But currently this is not possible,
4484    because this function is called via REGISTER_TARGET_PRAGMAS.  */
4485 void
4486 c_register_addr_space (const char * /*word*/, addr_space_t /*as*/)
4487 {
4488 }
4489
4490 /* Return the number of operands in T that we care about for things like
4491    mangling.  */
4492
4493 int
4494 cp_tree_operand_length (const_tree t)
4495 {
4496   enum tree_code code = TREE_CODE (t);
4497
4498   if (TREE_CODE_CLASS (code) == tcc_vl_exp)
4499     return VL_EXP_OPERAND_LENGTH (t);
4500
4501   return cp_tree_code_length (code);
4502 }
4503
4504 /* Like cp_tree_operand_length, but takes a tree_code CODE.  */
4505
4506 int
4507 cp_tree_code_length (enum tree_code code)
4508 {
4509   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
4510
4511   switch (code)
4512     {
4513     case PREINCREMENT_EXPR:
4514     case PREDECREMENT_EXPR:
4515     case POSTINCREMENT_EXPR:
4516     case POSTDECREMENT_EXPR:
4517       return 1;
4518
4519     case ARRAY_REF:
4520       return 2;
4521
4522     case EXPR_PACK_EXPANSION:
4523       return 1;
4524
4525     default:
4526       return TREE_CODE_LENGTH (code);
4527     }
4528 }
4529
4530 /* Implement -Wzero_as_null_pointer_constant.  Return true if the
4531    conditions for the warning hold, false otherwise.  */
4532 bool
4533 maybe_warn_zero_as_null_pointer_constant (tree expr, location_t loc)
4534 {
4535   if (c_inhibit_evaluation_warnings == 0
4536       && !NULLPTR_TYPE_P (TREE_TYPE (expr)))
4537     {
4538       warning_at (loc, OPT_Wzero_as_null_pointer_constant,
4539                   "zero as null pointer constant");
4540       return true;
4541     }
4542   return false;
4543 }
4544 \f
4545 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4546 /* Complain that some language-specific thing hanging off a tree
4547    node has been accessed improperly.  */
4548
4549 void
4550 lang_check_failed (const char* file, int line, const char* function)
4551 {
4552   internal_error ("lang_* check: failed in %s, at %s:%d",
4553                   function, trim_filename (file), line);
4554 }
4555 #endif /* ENABLE_TREE_CHECKING */
4556
4557 #include "gt-cp-tree.h"