gcc/c-common.c

   1 /* Subroutines shared by all languages that are variants of C.
   2    Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
   3    2001, 2002 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "tree.h"
  25 #include "real.h"
  26 #include "flags.h"
  27 #include "toplev.h"
  28 #include "output.h"
  29 #include "c-pragma.h"
  30 #include "rtl.h"
  31 #include "ggc.h"
  32 #include "expr.h"
  33 #include "c-common.h"
  34 #include "tree-inline.h"
  35 #include "diagnostic.h"
  36 #include "tm_p.h"
  37 #include "obstack.h"
  38 #include "cpplib.h"
  39 #include "target.h"
  40 #include "langhooks.h"
  41 #include "except.h"             /* For USING_SJLJ_EXCEPTIONS.  */
  42
  43 cpp_reader *parse_in;           /* Declared in c-pragma.h.  */
  44
  45 /* We let tm.h override the types used here, to handle trivial differences
  46    such as the choice of unsigned int or long unsigned int for size_t.
  47    When machines start needing nontrivial differences in the size type,
  48    it would be best to do something here to figure out automatically
  49    from other information what type to use.  */
  50
  51 #ifndef SIZE_TYPE
  52 #define SIZE_TYPE "long unsigned int"
  53 #endif
  54
  55 #ifndef WCHAR_TYPE
  56 #define WCHAR_TYPE "int"
  57 #endif
  58
  59 /* WCHAR_TYPE gets overridden by -fshort-wchar.  */
  60 #define MODIFIED_WCHAR_TYPE \
  61         (flag_short_wchar ? "short unsigned int" : WCHAR_TYPE)
  62
  63 #ifndef PTRDIFF_TYPE
  64 #define PTRDIFF_TYPE "long int"
  65 #endif
  66
  67 #ifndef WINT_TYPE
  68 #define WINT_TYPE "unsigned int"
  69 #endif
  70
  71 #ifndef INTMAX_TYPE
  72 #define INTMAX_TYPE ((INT_TYPE_SIZE == LONG_LONG_TYPE_SIZE)     \
  73                      ? "int"                                    \
  74                      : ((LONG_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \
  75                         ? "long int"                            \
  76                         : "long long int"))
  77 #endif
  78
  79 #ifndef UINTMAX_TYPE
  80 #define UINTMAX_TYPE ((INT_TYPE_SIZE == LONG_LONG_TYPE_SIZE)    \
  81                      ? "unsigned int"                           \
  82                      : ((LONG_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \
  83                         ? "long unsigned int"                   \
  84                         : "long long unsigned int"))
  85 #endif
  86
  87 #ifndef STDC_0_IN_SYSTEM_HEADERS
  88 #define STDC_0_IN_SYSTEM_HEADERS 0
  89 #endif
  90
  91 #ifndef REGISTER_PREFIX
  92 #define REGISTER_PREFIX ""
  93 #endif
  94
  95 /* The variant of the C language being processed.  */
  96
  97 enum c_language_kind c_language;
  98
  99 /* The following symbols are subsumed in the c_global_trees array, and
 100    listed here individually for documentation purposes.
 101
 102    INTEGER_TYPE and REAL_TYPE nodes for the standard data types.
 103
 104         tree short_integer_type_node;
 105         tree long_integer_type_node;
 106         tree long_long_integer_type_node;
 107
 108         tree short_unsigned_type_node;
 109         tree long_unsigned_type_node;
 110         tree long_long_unsigned_type_node;
 111
 112         tree boolean_type_node;
 113         tree boolean_false_node;
 114         tree boolean_true_node;
 115
 116         tree ptrdiff_type_node;
 117
 118         tree unsigned_char_type_node;
 119         tree signed_char_type_node;
 120         tree wchar_type_node;
 121         tree signed_wchar_type_node;
 122         tree unsigned_wchar_type_node;
 123
 124         tree float_type_node;
 125         tree double_type_node;
 126         tree long_double_type_node;
 127
 128         tree complex_integer_type_node;
 129         tree complex_float_type_node;
 130         tree complex_double_type_node;
 131         tree complex_long_double_type_node;
 132
 133         tree intQI_type_node;
 134         tree intHI_type_node;
 135         tree intSI_type_node;
 136         tree intDI_type_node;
 137         tree intTI_type_node;
 138
 139         tree unsigned_intQI_type_node;
 140         tree unsigned_intHI_type_node;
 141         tree unsigned_intSI_type_node;
 142         tree unsigned_intDI_type_node;
 143         tree unsigned_intTI_type_node;
 144
 145         tree widest_integer_literal_type_node;
 146         tree widest_unsigned_literal_type_node;
 147
 148    Nodes for types `void *' and `const void *'.
 149
 150         tree ptr_type_node, const_ptr_type_node;
 151
 152    Nodes for types `char *' and `const char *'.
 153
 154         tree string_type_node, const_string_type_node;
 155
 156    Type `char[SOMENUMBER]'.
 157    Used when an array of char is needed and the size is irrelevant.
 158
 159         tree char_array_type_node;
 160
 161    Type `int[SOMENUMBER]' or something like it.
 162    Used when an array of int needed and the size is irrelevant.
 163
 164         tree int_array_type_node;
 165
 166    Type `wchar_t[SOMENUMBER]' or something like it.
 167    Used when a wide string literal is created.
 168
 169         tree wchar_array_type_node;
 170
 171    Type `int ()' -- used for implicit declaration of functions.
 172
 173         tree default_function_type;
 174
 175    A VOID_TYPE node, packaged in a TREE_LIST.
 176
 177         tree void_list_node;
 178
 179   The lazily created VAR_DECLs for __FUNCTION__, __PRETTY_FUNCTION__,
 180   and __func__. (C doesn't generate __FUNCTION__ and__PRETTY_FUNCTION__
 181   VAR_DECLS, but C++ does.)
 182
 183         tree function_name_decl_node;
 184         tree pretty_function_name_decl_node;
 185         tree c99_function_name_decl_node;
 186
 187   Stack of nested function name VAR_DECLs.
 188
 189         tree saved_function_name_decls;
 190
 191 */
 192
 193 tree c_global_trees[CTI_MAX];
 194
 195 /* Nonzero if prepreprocessing only.  */
 196 int flag_preprocess_only;
 197
 198 /* Nonzero if an ISO standard was selected.  It rejects macros in the
 199    user's namespace.  */
 200 int flag_iso;
 201
 202 /* Nonzero if -undef was given.  It suppresses target built-in macros
 203    and assertions.  */
 204 int flag_undef;
 205
 206 /* Nonzero means don't recognize the non-ANSI builtin functions.  */
 207
 208 int flag_no_builtin;
 209
 210 /* Nonzero means don't recognize the non-ANSI builtin functions.
 211    -ansi sets this.  */
 212
 213 int flag_no_nonansi_builtin;
 214
 215 /* Nonzero means give `double' the same size as `float'.  */
 216
 217 int flag_short_double;
 218
 219 /* Nonzero means give `wchar_t' the same size as `short'.  */
 220
 221 int flag_short_wchar;
 222
 223 /* Nonzero means allow Microsoft extensions without warnings or errors.  */
 224 int flag_ms_extensions;
 225
 226 /* Nonzero means warn about use of multicharacter literals.  */
 227
 228 int warn_multichar = 1;
 229
 230 /* Nonzero means warn about possible violations of sequence point rules.  */
 231
 232 int warn_sequence_point;
 233
 234 /* Nonzero means to warn about compile-time division by zero.  */
 235 int warn_div_by_zero = 1;
 236
 237 /* Warn about NULL being passed to argument slots marked as requiring
 238    non-NULL.  */
 239
 240 int warn_nonnull;
 241
 242 /* The elements of `ridpointers' are identifier nodes for the reserved
 243    type names and storage classes.  It is indexed by a RID_... value.  */
 244 tree *ridpointers;
 245
 246 tree (*make_fname_decl)                PARAMS ((tree, int));
 247
 248 /* If non-NULL, the address of a language-specific function that
 249    returns 1 for language-specific statement codes.  */
 250 int (*lang_statement_code_p)           PARAMS ((enum tree_code));
 251
 252 /* If non-NULL, the address of a language-specific function that takes
 253    any action required right before expand_function_end is called.  */
 254 void (*lang_expand_function_end)       PARAMS ((void));
 255
 256 /* Nonzero means the expression being parsed will never be evaluated.
 257    This is a count, since unevaluated expressions can nest.  */
 258 int skip_evaluation;
 259
 260 /* Information about how a function name is generated.  */
 261 struct fname_var_t
 262 {
 263   tree *const decl;     /* pointer to the VAR_DECL.  */
 264   const unsigned rid;   /* RID number for the identifier.  */
 265   const int pretty;     /* How pretty is it? */
 266 };
 267
 268 /* The three ways of getting then name of the current function.  */
 269
 270 const struct fname_var_t fname_vars[] =
 271 {
 272   /* C99 compliant __func__, must be first.  */
 273   {&c99_function_name_decl_node, RID_C99_FUNCTION_NAME, 0},
 274   /* GCC __FUNCTION__ compliant.  */
 275   {&function_name_decl_node, RID_FUNCTION_NAME, 0},
 276   /* GCC __PRETTY_FUNCTION__ compliant.  */
 277   {&pretty_function_name_decl_node, RID_PRETTY_FUNCTION_NAME, 1},
 278   {NULL, 0, 0},
 279 };
 280
 281 static int constant_fits_type_p         PARAMS ((tree, tree));
 282
 283 /* Keep a stack of if statements.  We record the number of compound
 284    statements seen up to the if keyword, as well as the line number
 285    and file of the if.  If a potentially ambiguous else is seen, that
 286    fact is recorded; the warning is issued when we can be sure that
 287    the enclosing if statement does not have an else branch.  */
 288 typedef struct
 289 {
 290   int compstmt_count;
 291   int line;
 292   const char *file;
 293   int needs_warning;
 294   tree if_stmt;
 295 } if_elt;
 296
 297 static if_elt *if_stack;
 298
 299 /* Amount of space in the if statement stack.  */
 300 static int if_stack_space = 0;
 301
 302 /* Stack pointer.  */
 303 static int if_stack_pointer = 0;
 304
 305 static void cb_register_builtins PARAMS ((cpp_reader *));
 306
 307 static tree handle_packed_attribute     PARAMS ((tree *, tree, tree, int,
 308                                                  bool *));
 309 static tree handle_nocommon_attribute   PARAMS ((tree *, tree, tree, int,
 310                                                  bool *));
 311 static tree handle_common_attribute     PARAMS ((tree *, tree, tree, int,
 312                                                  bool *));
 313 static tree handle_noreturn_attribute   PARAMS ((tree *, tree, tree, int,
 314                                                  bool *));
 315 static tree handle_noinline_attribute   PARAMS ((tree *, tree, tree, int,
 316                                                  bool *));
 317 static tree handle_always_inline_attribute PARAMS ((tree *, tree, tree, int,
 318                                                     bool *));
 319 static tree handle_used_attribute       PARAMS ((tree *, tree, tree, int,
 320                                                  bool *));
 321 static tree handle_unused_attribute     PARAMS ((tree *, tree, tree, int,
 322                                                  bool *));
 323 static tree handle_const_attribute      PARAMS ((tree *, tree, tree, int,
 324                                                  bool *));
 325 static tree handle_transparent_union_attribute PARAMS ((tree *, tree, tree,
 326                                                         int, bool *));
 327 static tree handle_constructor_attribute PARAMS ((tree *, tree, tree, int,
 328                                                   bool *));
 329 static tree handle_destructor_attribute PARAMS ((tree *, tree, tree, int,
 330                                                  bool *));
 331 static tree handle_mode_attribute       PARAMS ((tree *, tree, tree, int,
 332                                                  bool *));
 333 static tree handle_section_attribute    PARAMS ((tree *, tree, tree, int,
 334                                                  bool *));
 335 static tree handle_aligned_attribute    PARAMS ((tree *, tree, tree, int,
 336                                                  bool *));
 337 static tree handle_weak_attribute       PARAMS ((tree *, tree, tree, int,
 338                                                  bool *));
 339 static tree handle_alias_attribute      PARAMS ((tree *, tree, tree, int,
 340                                                  bool *));
 341 static tree handle_visibility_attribute PARAMS ((tree *, tree, tree, int,
 342                                                  bool *));
 343 static tree handle_no_instrument_function_attribute PARAMS ((tree *, tree,
 344                                                              tree, int,
 345                                                              bool *));
 346 static tree handle_malloc_attribute     PARAMS ((tree *, tree, tree, int,
 347                                                  bool *));
 348 static tree handle_no_limit_stack_attribute PARAMS ((tree *, tree, tree, int,
 349                                                      bool *));
 350 static tree handle_pure_attribute       PARAMS ((tree *, tree, tree, int,
 351                                                  bool *));
 352 static tree handle_deprecated_attribute PARAMS ((tree *, tree, tree, int,
 353                                                  bool *));
 354 static tree handle_vector_size_attribute PARAMS ((tree *, tree, tree, int,
 355                                                   bool *));
 356 static tree handle_nonnull_attribute    PARAMS ((tree *, tree, tree, int,
 357                                                  bool *));
 358 static tree handle_nothrow_attribute    PARAMS ((tree *, tree, tree, int,
 359                                                  bool *));
 360 static tree vector_size_helper PARAMS ((tree, tree));
 361
 362 static void check_function_nonnull      PARAMS ((tree, tree));
 363 static void check_nonnull_arg           PARAMS ((void *, tree,
 364                                                  unsigned HOST_WIDE_INT));
 365 static bool nonnull_check_p             PARAMS ((tree, unsigned HOST_WIDE_INT));
 366 static bool get_nonnull_operand         PARAMS ((tree,
 367                                                  unsigned HOST_WIDE_INT *));
 368 void builtin_define_std PARAMS ((const char *));
 369 static void builtin_define_with_value PARAMS ((const char *, const char *,
 370                                                int));
 371 static void builtin_define_type_max PARAMS ((const char *, tree, int));
 372
 373 /* Table of machine-independent attributes common to all C-like languages.  */
 374 const struct attribute_spec c_common_attribute_table[] =
 375 {
 376   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 377   { "packed",                 0, 0, false, false, false,
 378                               handle_packed_attribute },
 379   { "nocommon",               0, 0, true,  false, false,
 380                               handle_nocommon_attribute },
 381   { "common",                 0, 0, true,  false, false,
 382                               handle_common_attribute },
 383   /* FIXME: logically, noreturn attributes should be listed as
 384      "false, true, true" and apply to function types.  But implementing this
 385      would require all the places in the compiler that use TREE_THIS_VOLATILE
 386      on a decl to identify non-returning functions to be located and fixed
 387      to check the function type instead.  */
 388   { "noreturn",               0, 0, true,  false, false,
 389                               handle_noreturn_attribute },
 390   { "volatile",               0, 0, true,  false, false,
 391                               handle_noreturn_attribute },
 392   { "noinline",               0, 0, true,  false, false,
 393                               handle_noinline_attribute },
 394   { "always_inline",          0, 0, true,  false, false,
 395                               handle_always_inline_attribute },
 396   { "used",                   0, 0, true,  false, false,
 397                               handle_used_attribute },
 398   { "unused",                 0, 0, false, false, false,
 399                               handle_unused_attribute },
 400   /* The same comments as for noreturn attributes apply to const ones.  */
 401   { "const",                  0, 0, true,  false, false,
 402                               handle_const_attribute },
 403   { "transparent_union",      0, 0, false, false, false,
 404                               handle_transparent_union_attribute },
 405   { "constructor",            0, 0, true,  false, false,
 406                               handle_constructor_attribute },
 407   { "destructor",             0, 0, true,  false, false,
 408                               handle_destructor_attribute },
 409   { "mode",                   1, 1, false,  true, false,
 410                               handle_mode_attribute },
 411   { "section",                1, 1, true,  false, false,
 412                               handle_section_attribute },
 413   { "aligned",                0, 1, false, false, false,
 414                               handle_aligned_attribute },
 415   { "weak",                   0, 0, true,  false, false,
 416                               handle_weak_attribute },
 417   { "alias",                  1, 1, true,  false, false,
 418                               handle_alias_attribute },
 419   { "no_instrument_function", 0, 0, true,  false, false,
 420                               handle_no_instrument_function_attribute },
 421   { "malloc",                 0, 0, true,  false, false,
 422                               handle_malloc_attribute },
 423   { "no_stack_limit",         0, 0, true,  false, false,
 424                               handle_no_limit_stack_attribute },
 425   { "pure",                   0, 0, true,  false, false,
 426                               handle_pure_attribute },
 427   { "deprecated",             0, 0, false, false, false,
 428                               handle_deprecated_attribute },
 429   { "vector_size",            1, 1, false, true, false,
 430                               handle_vector_size_attribute },
 431   { "visibility",             1, 1, true,  false, false,
 432                               handle_visibility_attribute },
 433   { "nonnull",                0, -1, false, true, true,
 434                               handle_nonnull_attribute },
 435   { "nothrow",                0, 0, true,  false, false,
 436                               handle_nothrow_attribute },
 437   { "may_alias",              0, 0, false, true, false, NULL },
 438   { NULL,                     0, 0, false, false, false, NULL }
 439 };
 440
 441 /* Give the specifications for the format attributes, used by C and all
 442    descendents.  */
 443
 444 const struct attribute_spec c_common_format_attribute_table[] =
 445 {
 446   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 447   { "format",                 3, 3, false, true,  true,
 448                               handle_format_attribute },
 449   { "format_arg",             1, 1, false, true,  true,
 450                               handle_format_arg_attribute },
 451   { NULL,                     0, 0, false, false, false, NULL }
 452 };
 453
 454 /* Record the start of an if-then, and record the start of it
 455    for ambiguous else detection.
 456
 457    COND is the condition for the if-then statement.
 458
 459    IF_STMT is the statement node that has already been created for
 460    this if-then statement.  It is created before parsing the
 461    condition to keep line number information accurate.  */
 462
 463 void
 464 c_expand_start_cond (cond, compstmt_count, if_stmt)
 465      tree cond;
 466      int compstmt_count;
 467      tree if_stmt;
 468 {
 469   /* Make sure there is enough space on the stack.  */
 470   if (if_stack_space == 0)
 471     {
 472       if_stack_space = 10;
 473       if_stack = (if_elt *) xmalloc (10 * sizeof (if_elt));
 474     }
 475   else if (if_stack_space == if_stack_pointer)
 476     {
 477       if_stack_space += 10;
 478       if_stack = (if_elt *) xrealloc (if_stack, if_stack_space * sizeof (if_elt));
 479     }
 480
 481   IF_COND (if_stmt) = cond;
 482   add_stmt (if_stmt);
 483
 484   /* Record this if statement.  */
 485   if_stack[if_stack_pointer].compstmt_count = compstmt_count;
 486   if_stack[if_stack_pointer].file = input_filename;
 487   if_stack[if_stack_pointer].line = lineno;
 488   if_stack[if_stack_pointer].needs_warning = 0;
 489   if_stack[if_stack_pointer].if_stmt = if_stmt;
 490   if_stack_pointer++;
 491 }
 492
 493 /* Called after the then-clause for an if-statement is processed.  */
 494
 495 void
 496 c_finish_then ()
 497 {
 498   tree if_stmt = if_stack[if_stack_pointer - 1].if_stmt;
 499   RECHAIN_STMTS (if_stmt, THEN_CLAUSE (if_stmt));
 500 }
 501
 502 /* Record the end of an if-then.  Optionally warn if a nested
 503    if statement had an ambiguous else clause.  */
 504
 505 void
 506 c_expand_end_cond ()
 507 {
 508   if_stack_pointer--;
 509   if (if_stack[if_stack_pointer].needs_warning)
 510     warning_with_file_and_line (if_stack[if_stack_pointer].file,
 511                                 if_stack[if_stack_pointer].line,
 512                                 "suggest explicit braces to avoid ambiguous `else'");
 513   last_expr_type = NULL_TREE;
 514 }
 515
 516 /* Called between the then-clause and the else-clause
 517    of an if-then-else.  */
 518
 519 void
 520 c_expand_start_else ()
 521 {
 522   /* An ambiguous else warning must be generated for the enclosing if
 523      statement, unless we see an else branch for that one, too.  */
 524   if (warn_parentheses
 525       && if_stack_pointer > 1
 526       && (if_stack[if_stack_pointer - 1].compstmt_count
 527           == if_stack[if_stack_pointer - 2].compstmt_count))
 528     if_stack[if_stack_pointer - 2].needs_warning = 1;
 529
 530   /* Even if a nested if statement had an else branch, it can't be
 531      ambiguous if this one also has an else.  So don't warn in that
 532      case.  Also don't warn for any if statements nested in this else.  */
 533   if_stack[if_stack_pointer - 1].needs_warning = 0;
 534   if_stack[if_stack_pointer - 1].compstmt_count--;
 535 }
 536
 537 /* Called after the else-clause for an if-statement is processed.  */
 538
 539 void
 540 c_finish_else ()
 541 {
 542   tree if_stmt = if_stack[if_stack_pointer - 1].if_stmt;
 543   RECHAIN_STMTS (if_stmt, ELSE_CLAUSE (if_stmt));
 544 }
 545
 546 /* Begin an if-statement.  Returns a newly created IF_STMT if
 547    appropriate.
 548
 549    Unlike the C++ front-end, we do not call add_stmt here; it is
 550    probably safe to do so, but I am not very familiar with this
 551    code so I am being extra careful not to change its behavior
 552    beyond what is strictly necessary for correctness.  */
 553
 554 tree
 555 c_begin_if_stmt ()
 556 {
 557   tree r;
 558   r = build_stmt (IF_STMT, NULL_TREE, NULL_TREE, NULL_TREE);
 559   return r;
 560 }
 561
 562 /* Begin a while statement.  Returns a newly created WHILE_STMT if
 563    appropriate.
 564
 565    Unlike the C++ front-end, we do not call add_stmt here; it is
 566    probably safe to do so, but I am not very familiar with this
 567    code so I am being extra careful not to change its behavior
 568    beyond what is strictly necessary for correctness.  */
 569
 570 tree
 571 c_begin_while_stmt ()
 572 {
 573   tree r;
 574   r = build_stmt (WHILE_STMT, NULL_TREE, NULL_TREE);
 575   return r;
 576 }
 577
 578 void
 579 c_finish_while_stmt_cond (cond, while_stmt)
 580      tree while_stmt;
 581      tree cond;
 582 {
 583   WHILE_COND (while_stmt) = cond;
 584 }
 585
 586 /* Push current bindings for the function name VAR_DECLS.  */
 587
 588 void
 589 start_fname_decls ()
 590 {
 591   unsigned ix;
 592   tree saved = NULL_TREE;
 593
 594   for (ix = 0; fname_vars[ix].decl; ix++)
 595     {
 596       tree decl = *fname_vars[ix].decl;
 597
 598       if (decl)
 599         {
 600           saved = tree_cons (decl, build_int_2 (ix, 0), saved);
 601           *fname_vars[ix].decl = NULL_TREE;
 602         }
 603     }
 604   if (saved || saved_function_name_decls)
 605     /* Normally they'll have been NULL, so only push if we've got a
 606        stack, or they are non-NULL.  */
 607     saved_function_name_decls = tree_cons (saved, NULL_TREE,
 608                                            saved_function_name_decls);
 609 }
 610
 611 /* Finish up the current bindings, adding them into the
 612    current function's statement tree. This is done by wrapping the
 613    function's body in a COMPOUND_STMT containing these decls too. This
 614    must be done _before_ finish_stmt_tree is called. If there is no
 615    current function, we must be at file scope and no statements are
 616    involved. Pop the previous bindings.  */
 617
 618 void
 619 finish_fname_decls ()
 620 {
 621   unsigned ix;
 622   tree body = NULL_TREE;
 623   tree stack = saved_function_name_decls;
 624
 625   for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack))
 626     body = chainon (TREE_VALUE (stack), body);
 627
 628   if (body)
 629     {
 630       /* They were called into existence, so add to statement tree.  */
 631       body = chainon (body,
 632                       TREE_CHAIN (DECL_SAVED_TREE (current_function_decl)));
 633       body = build_stmt (COMPOUND_STMT, body);
 634
 635       COMPOUND_STMT_NO_SCOPE (body) = 1;
 636       TREE_CHAIN (DECL_SAVED_TREE (current_function_decl)) = body;
 637     }
 638
 639   for (ix = 0; fname_vars[ix].decl; ix++)
 640     *fname_vars[ix].decl = NULL_TREE;
 641
 642   if (stack)
 643     {
 644       /* We had saved values, restore them.  */
 645       tree saved;
 646
 647       for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved))
 648         {
 649           tree decl = TREE_PURPOSE (saved);
 650           unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved));
 651
 652           *fname_vars[ix].decl = decl;
 653         }
 654       stack = TREE_CHAIN (stack);
 655     }
 656   saved_function_name_decls = stack;
 657 }
 658
 659 /* Return the text name of the current function, suitable prettified
 660    by PRETTY_P.  */
 661
 662 const char *
 663 fname_as_string (pretty_p)
 664      int pretty_p;
 665 {
 666   const char *name = NULL;
 667
 668   if (pretty_p)
 669     name = (current_function_decl
 670             ? (*lang_hooks.decl_printable_name) (current_function_decl, 2)
 671             : "top level");
 672   else if (current_function_decl && DECL_NAME (current_function_decl))
 673     name = IDENTIFIER_POINTER (DECL_NAME (current_function_decl));
 674   else
 675     name = "";
 676   return name;
 677 }
 678
 679 /* Return the text name of the current function, formatted as
 680    required by the supplied RID value.  */
 681
 682 const char *
 683 fname_string (rid)
 684      unsigned rid;
 685 {
 686   unsigned ix;
 687
 688   for (ix = 0; fname_vars[ix].decl; ix++)
 689     if (fname_vars[ix].rid == rid)
 690       break;
 691   return fname_as_string (fname_vars[ix].pretty);
 692 }
 693
 694 /* Return the VAR_DECL for a const char array naming the current
 695    function. If the VAR_DECL has not yet been created, create it
 696    now. RID indicates how it should be formatted and IDENTIFIER_NODE
 697    ID is its name (unfortunately C and C++ hold the RID values of
 698    keywords in different places, so we can't derive RID from ID in
 699    this language independent code.  */
 700
 701 tree
 702 fname_decl (rid, id)
 703      unsigned rid;
 704      tree id;
 705 {
 706   unsigned ix;
 707   tree decl = NULL_TREE;
 708
 709   for (ix = 0; fname_vars[ix].decl; ix++)
 710     if (fname_vars[ix].rid == rid)
 711       break;
 712
 713   decl = *fname_vars[ix].decl;
 714   if (!decl)
 715     {
 716       tree saved_last_tree = last_tree;
 717
 718       decl = (*make_fname_decl) (id, fname_vars[ix].pretty);
 719       if (last_tree != saved_last_tree)
 720         {
 721           /* We created some statement tree for the decl. This belongs
 722              at the start of the function, so remove it now and reinsert
 723              it after the function is complete.  */
 724           tree stmts = TREE_CHAIN (saved_last_tree);
 725
 726           TREE_CHAIN (saved_last_tree) = NULL_TREE;
 727           last_tree = saved_last_tree;
 728           saved_function_name_decls = tree_cons (decl, stmts,
 729                                                  saved_function_name_decls);
 730         }
 731       *fname_vars[ix].decl = decl;
 732     }
 733   if (!ix && !current_function_decl)
 734     pedwarn_with_decl (decl, "`%s' is not defined outside of function scope");
 735
 736   return decl;
 737 }
 738
 739 /* Given a STRING_CST, give it a suitable array-of-chars data type.  */
 740
 741 tree
 742 fix_string_type (value)
 743       tree value;
 744 {
 745   const int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
 746   const int wide_flag = TREE_TYPE (value) == wchar_array_type_node;
 747   const int nchars_max = flag_isoc99 ? 4095 : 509;
 748   int length = TREE_STRING_LENGTH (value);
 749   int nchars;
 750
 751   /* Compute the number of elements, for the array type.  */
 752   nchars = wide_flag ? length / wchar_bytes : length;
 753
 754   if (pedantic && nchars - 1 > nchars_max && c_language == clk_c)
 755     pedwarn ("string length `%d' is greater than the length `%d' ISO C%d compilers are required to support",
 756              nchars - 1, nchars_max, flag_isoc99 ? 99 : 89);
 757
 758   /* Create the array type for the string constant.
 759      -Wwrite-strings says make the string constant an array of const char
 760      so that copying it to a non-const pointer will get a warning.
 761      For C++, this is the standard behavior.  */
 762   if (flag_const_strings && ! flag_writable_strings)
 763     {
 764       tree elements
 765         = build_type_variant (wide_flag ? wchar_type_node : char_type_node,
 766                               1, 0);
 767       TREE_TYPE (value)
 768         = build_array_type (elements,
 769                             build_index_type (build_int_2 (nchars - 1, 0)));
 770     }
 771   else
 772     TREE_TYPE (value)
 773       = build_array_type (wide_flag ? wchar_type_node : char_type_node,
 774                           build_index_type (build_int_2 (nchars - 1, 0)));
 775
 776   TREE_CONSTANT (value) = 1;
 777   TREE_READONLY (value) = ! flag_writable_strings;
 778   TREE_STATIC (value) = 1;
 779   return value;
 780 }
 781
 782 /* Given a VARRAY of STRING_CST nodes, concatenate them into one
 783    STRING_CST.  */
 784
 785 tree
 786 combine_strings (strings)
 787      varray_type strings;
 788 {
 789   const int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
 790   const int nstrings = VARRAY_ACTIVE_SIZE (strings);
 791   tree value, t;
 792   int length = 1;
 793   int wide_length = 0;
 794   int wide_flag = 0;
 795   int i;
 796   char *p, *q;
 797
 798   /* Don't include the \0 at the end of each substring.  Count wide
 799      strings and ordinary strings separately.  */
 800   for (i = 0; i < nstrings; ++i)
 801     {
 802       t = VARRAY_TREE (strings, i);
 803
 804       if (TREE_TYPE (t) == wchar_array_type_node)
 805         {
 806           wide_length += TREE_STRING_LENGTH (t) - wchar_bytes;
 807           wide_flag = 1;
 808         }
 809       else
 810         {
 811           length += (TREE_STRING_LENGTH (t) - 1);
 812           if (C_ARTIFICIAL_STRING_P (t) && !in_system_header)
 813             warning ("concatenation of string literals with __FUNCTION__ is deprecated");
 814         }
 815     }
 816
 817   /* If anything is wide, the non-wides will be converted,
 818      which makes them take more space.  */
 819   if (wide_flag)
 820     length = length * wchar_bytes + wide_length;
 821
 822   p = xmalloc (length);
 823
 824   /* Copy the individual strings into the new combined string.
 825      If the combined string is wide, convert the chars to ints
 826      for any individual strings that are not wide.  */
 827
 828   q = p;
 829   for (i = 0; i < nstrings; ++i)
 830     {
 831       int len, this_wide;
 832
 833       t = VARRAY_TREE (strings, i);
 834       this_wide = TREE_TYPE (t) == wchar_array_type_node;
 835       len = TREE_STRING_LENGTH (t) - (this_wide ? wchar_bytes : 1);
 836       if (this_wide == wide_flag)
 837         {
 838           memcpy (q, TREE_STRING_POINTER (t), len);
 839           q += len;
 840         }
 841       else
 842         {
 843           const int nzeros = (TYPE_PRECISION (wchar_type_node)
 844                               / BITS_PER_UNIT) - 1;
 845           int j, k;
 846
 847           if (BYTES_BIG_ENDIAN)
 848             {
 849               for (k = 0; k < len; k++)
 850                 {
 851                   for (j = 0; j < nzeros; j++)
 852                     *q++ = 0;
 853                   *q++ = TREE_STRING_POINTER (t)[k];
 854                 }
 855             }
 856           else
 857             {
 858               for (k = 0; k < len; k++)
 859                 {
 860                   *q++ = TREE_STRING_POINTER (t)[k];
 861                   for (j = 0; j < nzeros; j++)
 862                     *q++ = 0;
 863                 }
 864             }
 865         }
 866     }
 867
 868   /* Nul terminate the string.  */
 869   if (wide_flag)
 870     {
 871       for (i = 0; i < wchar_bytes; i++)
 872         *q++ = 0;
 873     }
 874   else
 875     *q = 0;
 876
 877   value = build_string (length, p);
 878   free (p);
 879
 880   if (wide_flag)
 881     TREE_TYPE (value) = wchar_array_type_node;
 882   else
 883     TREE_TYPE (value) = char_array_type_node;
 884
 885   return value;
 886 }
 887 \f
 888 static int is_valid_printf_arglist PARAMS ((tree));
 889 static rtx c_expand_builtin PARAMS ((tree, rtx, enum machine_mode, enum expand_modifier));
 890 static rtx c_expand_builtin_printf PARAMS ((tree, rtx, enum machine_mode,
 891                                             enum expand_modifier, int, int));
 892 static rtx c_expand_builtin_fprintf PARAMS ((tree, rtx, enum machine_mode,
 893                                              enum expand_modifier, int, int));
 894 \f
 895 /* Print a warning if a constant expression had overflow in folding.
 896    Invoke this function on every expression that the language
 897    requires to be a constant expression.
 898    Note the ANSI C standard says it is erroneous for a
 899    constant expression to overflow.  */
 900
 901 void
 902 constant_expression_warning (value)
 903      tree value;
 904 {
 905   if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
 906        || TREE_CODE (value) == VECTOR_CST
 907        || TREE_CODE (value) == COMPLEX_CST)
 908       && TREE_CONSTANT_OVERFLOW (value) && pedantic)
 909     pedwarn ("overflow in constant expression");
 910 }
 911
 912 /* Print a warning if an expression had overflow in folding.
 913    Invoke this function on every expression that
 914    (1) appears in the source code, and
 915    (2) might be a constant expression that overflowed, and
 916    (3) is not already checked by convert_and_check;
 917    however, do not invoke this function on operands of explicit casts.  */
 918
 919 void
 920 overflow_warning (value)
 921      tree value;
 922 {
 923   if ((TREE_CODE (value) == INTEGER_CST
 924        || (TREE_CODE (value) == COMPLEX_CST
 925            && TREE_CODE (TREE_REALPART (value)) == INTEGER_CST))
 926       && TREE_OVERFLOW (value))
 927     {
 928       TREE_OVERFLOW (value) = 0;
 929       if (skip_evaluation == 0)
 930         warning ("integer overflow in expression");
 931     }
 932   else if ((TREE_CODE (value) == REAL_CST
 933             || (TREE_CODE (value) == COMPLEX_CST
 934                 && TREE_CODE (TREE_REALPART (value)) == REAL_CST))
 935            && TREE_OVERFLOW (value))
 936     {
 937       TREE_OVERFLOW (value) = 0;
 938       if (skip_evaluation == 0)
 939         warning ("floating point overflow in expression");
 940     }
 941   else if (TREE_CODE (value) == VECTOR_CST && TREE_OVERFLOW (value))
 942     {
 943       TREE_OVERFLOW (value) = 0;
 944       if (skip_evaluation == 0)
 945         warning ("vector overflow in expression");
 946     }
 947 }
 948
 949 /* Print a warning if a large constant is truncated to unsigned,
 950    or if -Wconversion is used and a constant < 0 is converted to unsigned.
 951    Invoke this function on every expression that might be implicitly
 952    converted to an unsigned type.  */
 953
 954 void
 955 unsigned_conversion_warning (result, operand)
 956      tree result, operand;
 957 {
 958   tree type = TREE_TYPE (result);
 959
 960   if (TREE_CODE (operand) == INTEGER_CST
 961       && TREE_CODE (type) == INTEGER_TYPE
 962       && TREE_UNSIGNED (type)
 963       && skip_evaluation == 0
 964       && !int_fits_type_p (operand, type))
 965     {
 966       if (!int_fits_type_p (operand, c_common_signed_type (type)))
 967         /* This detects cases like converting -129 or 256 to unsigned char.  */
 968         warning ("large integer implicitly truncated to unsigned type");
 969       else if (warn_conversion)
 970         warning ("negative integer implicitly converted to unsigned type");
 971     }
 972 }
 973
 974 /* Nonzero if constant C has a value that is permissible
 975    for type TYPE (an INTEGER_TYPE).  */
 976
 977 static int
 978 constant_fits_type_p (c, type)
 979      tree c, type;
 980 {
 981   if (TREE_CODE (c) == INTEGER_CST)
 982     return int_fits_type_p (c, type);
 983
 984   c = convert (type, c);
 985   return !TREE_OVERFLOW (c);
 986 }
 987
 988 /* Convert EXPR to TYPE, warning about conversion problems with constants.
 989    Invoke this function on every expression that is converted implicitly,
 990    i.e. because of language rules and not because of an explicit cast.  */
 991
 992 tree
 993 convert_and_check (type, expr)
 994      tree type, expr;
 995 {
 996   tree t = convert (type, expr);
 997   if (TREE_CODE (t) == INTEGER_CST)
 998     {
 999       if (TREE_OVERFLOW (t))
1000         {
1001           TREE_OVERFLOW (t) = 0;
1002
1003           /* Do not diagnose overflow in a constant expression merely
1004              because a conversion overflowed.  */
1005           TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (expr);
1006
1007           /* No warning for converting 0x80000000 to int.  */
1008           if (!(TREE_UNSIGNED (type) < TREE_UNSIGNED (TREE_TYPE (expr))
1009                 && TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
1010                 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (expr))))
1011             /* If EXPR fits in the unsigned version of TYPE,
1012                don't warn unless pedantic.  */
1013             if ((pedantic
1014                  || TREE_UNSIGNED (type)
1015                  || ! constant_fits_type_p (expr,
1016                                             c_common_unsigned_type (type)))
1017                 && skip_evaluation == 0)
1018               warning ("overflow in implicit constant conversion");
1019         }
1020       else
1021         unsigned_conversion_warning (t, expr);
1022     }
1023   return t;
1024 }
1025 \f
1026 /* A node in a list that describes references to variables (EXPR), which are
1027    either read accesses if WRITER is zero, or write accesses, in which case
1028    WRITER is the parent of EXPR.  */
1029 struct tlist
1030 {
1031   struct tlist *next;
1032   tree expr, writer;
1033 };
1034
1035 /* Used to implement a cache the results of a call to verify_tree.  We only
1036    use this for SAVE_EXPRs.  */
1037 struct tlist_cache
1038 {
1039   struct tlist_cache *next;
1040   struct tlist *cache_before_sp;
1041   struct tlist *cache_after_sp;
1042   tree expr;
1043 };
1044
1045 /* Obstack to use when allocating tlist structures, and corresponding
1046    firstobj.  */
1047 static struct obstack tlist_obstack;
1048 static char *tlist_firstobj = 0;
1049
1050 /* Keep track of the identifiers we've warned about, so we can avoid duplicate
1051    warnings.  */
1052 static struct tlist *warned_ids;
1053 /* SAVE_EXPRs need special treatment.  We process them only once and then
1054    cache the results.  */
1055 static struct tlist_cache *save_expr_cache;
1056
1057 static void add_tlist PARAMS ((struct tlist **, struct tlist *, tree, int));
1058 static void merge_tlist PARAMS ((struct tlist **, struct tlist *, int));
1059 static void verify_tree PARAMS ((tree, struct tlist **, struct tlist **, tree));
1060 static int warning_candidate_p PARAMS ((tree));
1061 static void warn_for_collisions PARAMS ((struct tlist *));
1062 static void warn_for_collisions_1 PARAMS ((tree, tree, struct tlist *, int));
1063 static struct tlist *new_tlist PARAMS ((struct tlist *, tree, tree));
1064 static void verify_sequence_points PARAMS ((tree));
1065
1066 /* Create a new struct tlist and fill in its fields.  */
1067 static struct tlist *
1068 new_tlist (next, t, writer)
1069      struct tlist *next;
1070      tree t;
1071      tree writer;
1072 {
1073   struct tlist *l;
1074   l = (struct tlist *) obstack_alloc (&tlist_obstack, sizeof *l);
1075   l->next = next;
1076   l->expr = t;
1077   l->writer = writer;
1078   return l;
1079 }
1080
1081 /* Add duplicates of the nodes found in ADD to the list *TO.  If EXCLUDE_WRITER
1082    is nonnull, we ignore any node we find which has a writer equal to it.  */
1083
1084 static void
1085 add_tlist (to, add, exclude_writer, copy)
1086      struct tlist **to;
1087      struct tlist *add;
1088      tree exclude_writer;
1089      int copy;
1090 {
1091   while (add)
1092     {
1093       struct tlist *next = add->next;
1094       if (! copy)
1095         add->next = *to;
1096       if (! exclude_writer || add->writer != exclude_writer)
1097         *to = copy ? new_tlist (*to, add->expr, add->writer) : add;
1098       add = next;
1099     }
1100 }
1101
1102 /* Merge the nodes of ADD into TO.  This merging process is done so that for
1103    each variable that already exists in TO, no new node is added; however if
1104    there is a write access recorded in ADD, and an occurrence on TO is only
1105    a read access, then the occurrence in TO will be modified to record the
1106    write.  */
1107
1108 static void
1109 merge_tlist (to, add, copy)
1110      struct tlist **to;
1111      struct tlist *add;
1112      int copy;
1113 {
1114   struct tlist **end = to;
1115
1116   while (*end)
1117     end = &(*end)->next;
1118
1119   while (add)
1120     {
1121       int found = 0;
1122       struct tlist *tmp2;
1123       struct tlist *next = add->next;
1124
1125       for (tmp2 = *to; tmp2; tmp2 = tmp2->next)
1126         if (tmp2->expr == add->expr)
1127           {
1128             found = 1;
1129             if (! tmp2->writer)
1130               tmp2->writer = add->writer;
1131           }
1132       if (! found)
1133         {
1134           *end = copy ? add : new_tlist (NULL, add->expr, add->writer);
1135           end = &(*end)->next;
1136           *end = 0;
1137         }
1138       add = next;
1139     }
1140 }
1141
1142 /* WRITTEN is a variable, WRITER is its parent.  Warn if any of the variable
1143    references in list LIST conflict with it, excluding reads if ONLY writers
1144    is nonzero.  */
1145
1146 static void
1147 warn_for_collisions_1 (written, writer, list, only_writes)
1148      tree written, writer;
1149      struct tlist *list;
1150      int only_writes;
1151 {
1152   struct tlist *tmp;
1153
1154   /* Avoid duplicate warnings.  */
1155   for (tmp = warned_ids; tmp; tmp = tmp->next)
1156     if (tmp->expr == written)
1157       return;
1158
1159   while (list)
1160     {
1161       if (list->expr == written
1162           && list->writer != writer
1163           && (! only_writes || list->writer))
1164         {
1165           warned_ids = new_tlist (warned_ids, written, NULL_TREE);
1166           warning ("operation on `%s' may be undefined",
1167                    IDENTIFIER_POINTER (DECL_NAME (list->expr)));
1168         }
1169       list = list->next;
1170     }
1171 }
1172
1173 /* Given a list LIST of references to variables, find whether any of these
1174    can cause conflicts due to missing sequence points.  */
1175
1176 static void
1177 warn_for_collisions (list)
1178      struct tlist *list;
1179 {
1180   struct tlist *tmp;
1181
1182   for (tmp = list; tmp; tmp = tmp->next)
1183     {
1184       if (tmp->writer)
1185         warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0);
1186     }
1187 }
1188
1189 /* Return nonzero if X is a tree that can be verified by the sequence point
1190    warnings.  */
1191 static int
1192 warning_candidate_p (x)
1193      tree x;
1194 {
1195   return TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == PARM_DECL;
1196 }
1197
1198 /* Walk the tree X, and record accesses to variables.  If X is written by the
1199    parent tree, WRITER is the parent.
1200    We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP.  If this
1201    expression or its only operand forces a sequence point, then everything up
1202    to the sequence point is stored in PBEFORE_SP.  Everything else gets stored
1203    in PNO_SP.
1204    Once we return, we will have emitted warnings if any subexpression before
1205    such a sequence point could be undefined.  On a higher level, however, the
1206    sequence point may not be relevant, and we'll merge the two lists.
1207
1208    Example: (b++, a) + b;
1209    The call that processes the COMPOUND_EXPR will store the increment of B
1210    in PBEFORE_SP, and the use of A in PNO_SP.  The higher-level call that
1211    processes the PLUS_EXPR will need to merge the two lists so that
1212    eventually, all accesses end up on the same list (and we'll warn about the
1213    unordered subexpressions b++ and b.
1214
1215    A note on merging.  If we modify the former example so that our expression
1216    becomes
1217      (b++, b) + a
1218    care must be taken not simply to add all three expressions into the final
1219    PNO_SP list.  The function merge_tlist takes care of that by merging the
1220    before-SP list of the COMPOUND_EXPR into its after-SP list in a special
1221    way, so that no more than one access to B is recorded.  */
1222
1223 static void
1224 verify_tree (x, pbefore_sp, pno_sp, writer)
1225      tree x;
1226      struct tlist **pbefore_sp, **pno_sp;
1227      tree writer;
1228 {
1229   struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3;
1230   enum tree_code code;
1231   char class;
1232
1233   /* X may be NULL if it is the operand of an empty statement expression
1234      ({ }).  */
1235   if (x == NULL)
1236     return;
1237
1238  restart:
1239   code = TREE_CODE (x);
1240   class = TREE_CODE_CLASS (code);
1241
1242   if (warning_candidate_p (x))
1243     {
1244       *pno_sp = new_tlist (*pno_sp, x, writer);
1245       return;
1246     }
1247
1248   switch (code)
1249     {
1250     case CONSTRUCTOR:
1251       return;
1252
1253     case COMPOUND_EXPR:
1254     case TRUTH_ANDIF_EXPR:
1255     case TRUTH_ORIF_EXPR:
1256       tmp_before = tmp_nosp = tmp_list3 = 0;
1257       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1258       warn_for_collisions (tmp_nosp);
1259       merge_tlist (pbefore_sp, tmp_before, 0);
1260       merge_tlist (pbefore_sp, tmp_nosp, 0);
1261       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE);
1262       merge_tlist (pbefore_sp, tmp_list3, 0);
1263       return;
1264
1265     case COND_EXPR:
1266       tmp_before = tmp_list2 = 0;
1267       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE);
1268       warn_for_collisions (tmp_list2);
1269       merge_tlist (pbefore_sp, tmp_before, 0);
1270       merge_tlist (pbefore_sp, tmp_list2, 1);
1271
1272       tmp_list3 = tmp_nosp = 0;
1273       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE);
1274       warn_for_collisions (tmp_nosp);
1275       merge_tlist (pbefore_sp, tmp_list3, 0);
1276
1277       tmp_list3 = tmp_list2 = 0;
1278       verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE);
1279       warn_for_collisions (tmp_list2);
1280       merge_tlist (pbefore_sp, tmp_list3, 0);
1281       /* Rather than add both tmp_nosp and tmp_list2, we have to merge the
1282          two first, to avoid warning for (a ? b++ : b++).  */
1283       merge_tlist (&tmp_nosp, tmp_list2, 0);
1284       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1285       return;
1286
1287     case PREDECREMENT_EXPR:
1288     case PREINCREMENT_EXPR:
1289     case POSTDECREMENT_EXPR:
1290     case POSTINCREMENT_EXPR:
1291       verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x);
1292       return;
1293
1294     case MODIFY_EXPR:
1295       tmp_before = tmp_nosp = tmp_list3 = 0;
1296       verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE);
1297       verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x);
1298       /* Expressions inside the LHS are not ordered wrt. the sequence points
1299          in the RHS.  Example:
1300            *a = (a++, 2)
1301          Despite the fact that the modification of "a" is in the before_sp
1302          list (tmp_before), it conflicts with the use of "a" in the LHS.
1303          We can handle this by adding the contents of tmp_list3
1304          to those of tmp_before, and redoing the collision warnings for that
1305          list.  */
1306       add_tlist (&tmp_before, tmp_list3, x, 1);
1307       warn_for_collisions (tmp_before);
1308       /* Exclude the LHS itself here; we first have to merge it into the
1309          tmp_nosp list.  This is done to avoid warning for "a = a"; if we
1310          didn't exclude the LHS, we'd get it twice, once as a read and once
1311          as a write.  */
1312       add_tlist (pno_sp, tmp_list3, x, 0);
1313       warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1);
1314
1315       merge_tlist (pbefore_sp, tmp_before, 0);
1316       if (warning_candidate_p (TREE_OPERAND (x, 0)))
1317         merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0);
1318       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1);
1319       return;
1320
1321     case CALL_EXPR:
1322       /* We need to warn about conflicts among arguments and conflicts between
1323          args and the function address.  Side effects of the function address,
1324          however, are not ordered by the sequence point of the call.  */
1325       tmp_before = tmp_nosp = tmp_list2 = tmp_list3 = 0;
1326       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1327       if (TREE_OPERAND (x, 1))
1328         verify_tree (TREE_OPERAND (x, 1), &tmp_list2, &tmp_list3, NULL_TREE);
1329       merge_tlist (&tmp_list3, tmp_list2, 0);
1330       add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0);
1331       add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0);
1332       warn_for_collisions (tmp_before);
1333       add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0);
1334       return;
1335
1336     case TREE_LIST:
1337       /* Scan all the list, e.g. indices of multi dimensional array.  */
1338       while (x)
1339         {
1340           tmp_before = tmp_nosp = 0;
1341           verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE);
1342           merge_tlist (&tmp_nosp, tmp_before, 0);
1343           add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1344           x = TREE_CHAIN (x);
1345         }
1346       return;
1347
1348     case SAVE_EXPR:
1349       {
1350         struct tlist_cache *t;
1351         for (t = save_expr_cache; t; t = t->next)
1352           if (t->expr == x)
1353             break;
1354
1355         if (! t)
1356           {
1357             t = (struct tlist_cache *) obstack_alloc (&tlist_obstack,
1358                                                       sizeof *t);
1359             t->next = save_expr_cache;
1360             t->expr = x;
1361             save_expr_cache = t;
1362
1363             tmp_before = tmp_nosp = 0;
1364             verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1365             warn_for_collisions (tmp_nosp);
1366
1367             tmp_list3 = 0;
1368             while (tmp_nosp)
1369               {
1370                 struct tlist *t = tmp_nosp;
1371                 tmp_nosp = t->next;
1372                 merge_tlist (&tmp_list3, t, 0);
1373               }
1374             t->cache_before_sp = tmp_before;
1375             t->cache_after_sp = tmp_list3;
1376           }
1377         merge_tlist (pbefore_sp, t->cache_before_sp, 1);
1378         add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1);
1379         return;
1380       }
1381     default:
1382       break;
1383     }
1384
1385   if (class == '1')
1386     {
1387       if (first_rtl_op (code) == 0)
1388         return;
1389       x = TREE_OPERAND (x, 0);
1390       writer = 0;
1391       goto restart;
1392     }
1393
1394   switch (class)
1395     {
1396     case 'r':
1397     case '<':
1398     case '2':
1399     case 'b':
1400     case 'e':
1401     case 's':
1402     case 'x':
1403       {
1404         int lp;
1405         int max = first_rtl_op (TREE_CODE (x));
1406         for (lp = 0; lp < max; lp++)
1407           {
1408             tmp_before = tmp_nosp = 0;
1409             verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, NULL_TREE);
1410             merge_tlist (&tmp_nosp, tmp_before, 0);
1411             add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1412           }
1413         break;
1414       }
1415     }
1416 }
1417
1418 /* Try to warn for undefined behaviour in EXPR due to missing sequence
1419    points.  */
1420
1421 static void
1422 verify_sequence_points (expr)
1423      tree expr;
1424 {
1425   struct tlist *before_sp = 0, *after_sp = 0;
1426
1427   warned_ids = 0;
1428   save_expr_cache = 0;
1429   if (tlist_firstobj == 0)
1430     {
1431       gcc_obstack_init (&tlist_obstack);
1432       tlist_firstobj = obstack_alloc (&tlist_obstack, 0);
1433     }
1434
1435   verify_tree (expr, &before_sp, &after_sp, 0);
1436   warn_for_collisions (after_sp);
1437   obstack_free (&tlist_obstack, tlist_firstobj);
1438 }
1439
1440 tree
1441 c_expand_expr_stmt (expr)
1442      tree expr;
1443 {
1444   /* Do default conversion if safe and possibly important,
1445      in case within ({...}).  */
1446   if ((TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE
1447        && (flag_isoc99 || lvalue_p (expr)))
1448       || TREE_CODE (TREE_TYPE (expr)) == FUNCTION_TYPE)
1449     expr = default_conversion (expr);
1450
1451   if (warn_sequence_point)
1452     verify_sequence_points (expr);
1453
1454   if (TREE_TYPE (expr) != error_mark_node
1455       && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr))
1456       && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
1457     error ("expression statement has incomplete type");
1458
1459   last_expr_type = TREE_TYPE (expr);
1460   return add_stmt (build_stmt (EXPR_STMT, expr));
1461 }
1462 \f
1463 /* Validate the expression after `case' and apply default promotions.  */
1464
1465 tree
1466 check_case_value (value)
1467      tree value;
1468 {
1469   if (value == NULL_TREE)
1470     return value;
1471
1472   /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue.  */
1473   STRIP_TYPE_NOPS (value);
1474   /* In C++, the following is allowed:
1475
1476        const int i = 3;
1477        switch (...) { case i: ... }
1478
1479      So, we try to reduce the VALUE to a constant that way.  */
1480   if (c_language == clk_cplusplus)
1481     {
1482       value = decl_constant_value (value);
1483       STRIP_TYPE_NOPS (value);
1484       value = fold (value);
1485     }
1486
1487   if (TREE_CODE (value) != INTEGER_CST
1488       && value != error_mark_node)
1489     {
1490       error ("case label does not reduce to an integer constant");
1491       value = error_mark_node;
1492     }
1493   else
1494     /* Promote char or short to int.  */
1495     value = default_conversion (value);
1496
1497   constant_expression_warning (value);
1498
1499   return value;
1500 }
1501 \f
1502 /* Return an integer type with BITS bits of precision,
1503    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
1504
1505 tree
1506 c_common_type_for_size (bits, unsignedp)
1507      unsigned bits;
1508      int unsignedp;
1509 {
1510   if (bits == TYPE_PRECISION (integer_type_node))
1511     return unsignedp ? unsigned_type_node : integer_type_node;
1512
1513   if (bits == TYPE_PRECISION (signed_char_type_node))
1514     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1515
1516   if (bits == TYPE_PRECISION (short_integer_type_node))
1517     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1518
1519   if (bits == TYPE_PRECISION (long_integer_type_node))
1520     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1521
1522   if (bits == TYPE_PRECISION (long_long_integer_type_node))
1523     return (unsignedp ? long_long_unsigned_type_node
1524             : long_long_integer_type_node);
1525
1526   if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
1527     return (unsignedp ? widest_unsigned_literal_type_node
1528             : widest_integer_literal_type_node);
1529
1530   if (bits <= TYPE_PRECISION (intQI_type_node))
1531     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1532
1533   if (bits <= TYPE_PRECISION (intHI_type_node))
1534     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1535
1536   if (bits <= TYPE_PRECISION (intSI_type_node))
1537     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1538
1539   if (bits <= TYPE_PRECISION (intDI_type_node))
1540     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1541
1542   return 0;
1543 }
1544
1545 /* Return a data type that has machine mode MODE.
1546    If the mode is an integer,
1547    then UNSIGNEDP selects between signed and unsigned types.  */
1548
1549 tree
1550 c_common_type_for_mode (mode, unsignedp)
1551      enum machine_mode mode;
1552      int unsignedp;
1553 {
1554   if (mode == TYPE_MODE (integer_type_node))
1555     return unsignedp ? unsigned_type_node : integer_type_node;
1556
1557   if (mode == TYPE_MODE (signed_char_type_node))
1558     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1559
1560   if (mode == TYPE_MODE (short_integer_type_node))
1561     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1562
1563   if (mode == TYPE_MODE (long_integer_type_node))
1564     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1565
1566   if (mode == TYPE_MODE (long_long_integer_type_node))
1567     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
1568
1569   if (mode == TYPE_MODE (widest_integer_literal_type_node))
1570     return unsignedp ? widest_unsigned_literal_type_node
1571                      : widest_integer_literal_type_node;
1572
1573   if (mode == QImode)
1574     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1575
1576   if (mode == HImode)
1577     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1578
1579   if (mode == SImode)
1580     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1581
1582   if (mode == DImode)
1583     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1584
1585 #if HOST_BITS_PER_WIDE_INT >= 64
1586   if (mode == TYPE_MODE (intTI_type_node))
1587     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
1588 #endif
1589
1590   if (mode == TYPE_MODE (float_type_node))
1591     return float_type_node;
1592
1593   if (mode == TYPE_MODE (double_type_node))
1594     return double_type_node;
1595
1596   if (mode == TYPE_MODE (long_double_type_node))
1597     return long_double_type_node;
1598
1599   if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
1600     return build_pointer_type (char_type_node);
1601
1602   if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
1603     return build_pointer_type (integer_type_node);
1604
1605   switch (mode)
1606     {
1607     case V16QImode:
1608       return unsignedp ? unsigned_V16QI_type_node : V16QI_type_node;
1609     case V8HImode:
1610       return unsignedp ? unsigned_V8HI_type_node : V8HI_type_node;
1611     case V4SImode:
1612       return unsignedp ? unsigned_V4SI_type_node : V4SI_type_node;
1613     case V2DImode:
1614       return unsignedp ? unsigned_V2DI_type_node : V2DI_type_node;
1615     case V2SImode:
1616       return unsignedp ? unsigned_V2SI_type_node : V2SI_type_node;
1617     case V4HImode:
1618       return unsignedp ? unsigned_V4HI_type_node : V4HI_type_node;
1619     case V8QImode:
1620       return unsignedp ? unsigned_V8QI_type_node : V8QI_type_node;
1621     case V16SFmode:
1622       return V16SF_type_node;
1623     case V4SFmode:
1624       return V4SF_type_node;
1625     case V2SFmode:
1626       return V2SF_type_node;
1627     case V2DFmode:
1628       return V2DF_type_node;
1629     default:
1630       break;
1631     }
1632
1633   return 0;
1634 }
1635
1636 /* Return an unsigned type the same as TYPE in other respects.  */
1637 tree
1638 c_common_unsigned_type (type)
1639      tree type;
1640 {
1641   tree type1 = TYPE_MAIN_VARIANT (type);
1642   if (type1 == signed_char_type_node || type1 == char_type_node)
1643     return unsigned_char_type_node;
1644   if (type1 == integer_type_node)
1645     return unsigned_type_node;
1646   if (type1 == short_integer_type_node)
1647     return short_unsigned_type_node;
1648   if (type1 == long_integer_type_node)
1649     return long_unsigned_type_node;
1650   if (type1 == long_long_integer_type_node)
1651     return long_long_unsigned_type_node;
1652   if (type1 == widest_integer_literal_type_node)
1653     return widest_unsigned_literal_type_node;
1654 #if HOST_BITS_PER_WIDE_INT >= 64
1655   if (type1 == intTI_type_node)
1656     return unsigned_intTI_type_node;
1657 #endif
1658   if (type1 == intDI_type_node)
1659     return unsigned_intDI_type_node;
1660   if (type1 == intSI_type_node)
1661     return unsigned_intSI_type_node;
1662   if (type1 == intHI_type_node)
1663     return unsigned_intHI_type_node;
1664   if (type1 == intQI_type_node)
1665     return unsigned_intQI_type_node;
1666
1667   return c_common_signed_or_unsigned_type (1, type);
1668 }
1669
1670 /* Return a signed type the same as TYPE in other respects.  */
1671
1672 tree
1673 c_common_signed_type (type)
1674      tree type;
1675 {
1676   tree type1 = TYPE_MAIN_VARIANT (type);
1677   if (type1 == unsigned_char_type_node || type1 == char_type_node)
1678     return signed_char_type_node;
1679   if (type1 == unsigned_type_node)
1680     return integer_type_node;
1681   if (type1 == short_unsigned_type_node)
1682     return short_integer_type_node;
1683   if (type1 == long_unsigned_type_node)
1684     return long_integer_type_node;
1685   if (type1 == long_long_unsigned_type_node)
1686     return long_long_integer_type_node;
1687   if (type1 == widest_unsigned_literal_type_node)
1688     return widest_integer_literal_type_node;
1689 #if HOST_BITS_PER_WIDE_INT >= 64
1690   if (type1 == unsigned_intTI_type_node)
1691     return intTI_type_node;
1692 #endif
1693   if (type1 == unsigned_intDI_type_node)
1694     return intDI_type_node;
1695   if (type1 == unsigned_intSI_type_node)
1696     return intSI_type_node;
1697   if (type1 == unsigned_intHI_type_node)
1698     return intHI_type_node;
1699   if (type1 == unsigned_intQI_type_node)
1700     return intQI_type_node;
1701
1702   return c_common_signed_or_unsigned_type (0, type);
1703 }
1704
1705 /* Return a type the same as TYPE except unsigned or
1706    signed according to UNSIGNEDP.  */
1707
1708 tree
1709 c_common_signed_or_unsigned_type (unsignedp, type)
1710      int unsignedp;
1711      tree type;
1712 {
1713   if (! INTEGRAL_TYPE_P (type)
1714       || TREE_UNSIGNED (type) == unsignedp)
1715     return type;
1716
1717   if (TYPE_PRECISION (type) == TYPE_PRECISION (signed_char_type_node))
1718     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1719   if (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))
1720     return unsignedp ? unsigned_type_node : integer_type_node;
1721   if (TYPE_PRECISION (type) == TYPE_PRECISION (short_integer_type_node))
1722     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1723   if (TYPE_PRECISION (type) == TYPE_PRECISION (long_integer_type_node))
1724     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1725   if (TYPE_PRECISION (type) == TYPE_PRECISION (long_long_integer_type_node))
1726     return (unsignedp ? long_long_unsigned_type_node
1727             : long_long_integer_type_node);
1728   if (TYPE_PRECISION (type) == TYPE_PRECISION (widest_integer_literal_type_node))
1729     return (unsignedp ? widest_unsigned_literal_type_node
1730             : widest_integer_literal_type_node);
1731
1732 #if HOST_BITS_PER_WIDE_INT >= 64
1733   if (TYPE_PRECISION (type) == TYPE_PRECISION (intTI_type_node))
1734     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
1735 #endif
1736   if (TYPE_PRECISION (type) == TYPE_PRECISION (intDI_type_node))
1737     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1738   if (TYPE_PRECISION (type) == TYPE_PRECISION (intSI_type_node))
1739     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1740   if (TYPE_PRECISION (type) == TYPE_PRECISION (intHI_type_node))
1741     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1742   if (TYPE_PRECISION (type) == TYPE_PRECISION (intQI_type_node))
1743     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1744
1745   return type;
1746 }
1747 \f
1748 /* Return the minimum number of bits needed to represent VALUE in a
1749    signed or unsigned type, UNSIGNEDP says which.  */
1750
1751 unsigned int
1752 min_precision (value, unsignedp)
1753      tree value;
1754      int unsignedp;
1755 {
1756   int log;
1757
1758   /* If the value is negative, compute its negative minus 1.  The latter
1759      adjustment is because the absolute value of the largest negative value
1760      is one larger than the largest positive value.  This is equivalent to
1761      a bit-wise negation, so use that operation instead.  */
1762
1763   if (tree_int_cst_sgn (value) < 0)
1764     value = fold (build1 (BIT_NOT_EXPR, TREE_TYPE (value), value));
1765
1766   /* Return the number of bits needed, taking into account the fact
1767      that we need one more bit for a signed than unsigned type.  */
1768
1769   if (integer_zerop (value))
1770     log = 0;
1771   else
1772     log = tree_floor_log2 (value);
1773
1774   return log + 1 + ! unsignedp;
1775 }
1776 \f
1777 /* Print an error message for invalid operands to arith operation
1778    CODE.  NOP_EXPR is used as a special case (see
1779    c_common_truthvalue_conversion).  */
1780
1781 void
1782 binary_op_error (code)
1783      enum tree_code code;
1784 {
1785   const char *opname;
1786
1787   switch (code)
1788     {
1789     case NOP_EXPR:
1790       error ("invalid truth-value expression");
1791       return;
1792
1793     case PLUS_EXPR:
1794       opname = "+"; break;
1795     case MINUS_EXPR:
1796       opname = "-"; break;
1797     case MULT_EXPR:
1798       opname = "*"; break;
1799     case MAX_EXPR:
1800       opname = "max"; break;
1801     case MIN_EXPR:
1802       opname = "min"; break;
1803     case EQ_EXPR:
1804       opname = "=="; break;
1805     case NE_EXPR:
1806       opname = "!="; break;
1807     case LE_EXPR:
1808       opname = "<="; break;
1809     case GE_EXPR:
1810       opname = ">="; break;
1811     case LT_EXPR:
1812       opname = "<"; break;
1813     case GT_EXPR:
1814       opname = ">"; break;
1815     case LSHIFT_EXPR:
1816       opname = "<<"; break;
1817     case RSHIFT_EXPR:
1818       opname = ">>"; break;
1819     case TRUNC_MOD_EXPR:
1820     case FLOOR_MOD_EXPR:
1821       opname = "%"; break;
1822     case TRUNC_DIV_EXPR:
1823     case FLOOR_DIV_EXPR:
1824       opname = "/"; break;
1825     case BIT_AND_EXPR:
1826       opname = "&"; break;
1827     case BIT_IOR_EXPR:
1828       opname = "|"; break;
1829     case TRUTH_ANDIF_EXPR:
1830       opname = "&&"; break;
1831     case TRUTH_ORIF_EXPR:
1832       opname = "||"; break;
1833     case BIT_XOR_EXPR:
1834       opname = "^"; break;
1835     case LROTATE_EXPR:
1836     case RROTATE_EXPR:
1837       opname = "rotate"; break;
1838     default:
1839       opname = "unknown"; break;
1840     }
1841   error ("invalid operands to binary %s", opname);
1842 }
1843 \f
1844 /* Subroutine of build_binary_op, used for comparison operations.
1845    See if the operands have both been converted from subword integer types
1846    and, if so, perhaps change them both back to their original type.
1847    This function is also responsible for converting the two operands
1848    to the proper common type for comparison.
1849
1850    The arguments of this function are all pointers to local variables
1851    of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
1852    RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.
1853
1854    If this function returns nonzero, it means that the comparison has
1855    a constant value.  What this function returns is an expression for
1856    that value.  */
1857
1858 tree
1859 shorten_compare (op0_ptr, op1_ptr, restype_ptr, rescode_ptr)
1860      tree *op0_ptr, *op1_ptr;
1861      tree *restype_ptr;
1862      enum tree_code *rescode_ptr;
1863 {
1864   tree type;
1865   tree op0 = *op0_ptr;
1866   tree op1 = *op1_ptr;
1867   int unsignedp0, unsignedp1;
1868   int real1, real2;
1869   tree primop0, primop1;
1870   enum tree_code code = *rescode_ptr;
1871
1872   /* Throw away any conversions to wider types
1873      already present in the operands.  */
1874
1875   primop0 = get_narrower (op0, &unsignedp0);
1876   primop1 = get_narrower (op1, &unsignedp1);
1877
1878   /* Handle the case that OP0 does not *contain* a conversion
1879      but it *requires* conversion to FINAL_TYPE.  */
1880
1881   if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
1882     unsignedp0 = TREE_UNSIGNED (TREE_TYPE (op0));
1883   if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
1884     unsignedp1 = TREE_UNSIGNED (TREE_TYPE (op1));
1885
1886   /* If one of the operands must be floated, we cannot optimize.  */
1887   real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
1888   real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
1889
1890   /* If first arg is constant, swap the args (changing operation
1891      so value is preserved), for canonicalization.  Don't do this if
1892      the second arg is 0.  */
1893
1894   if (TREE_CONSTANT (primop0)
1895       && ! integer_zerop (primop1) && ! real_zerop (primop1))
1896     {
1897       tree tem = primop0;
1898       int temi = unsignedp0;
1899       primop0 = primop1;
1900       primop1 = tem;
1901       tem = op0;
1902       op0 = op1;
1903       op1 = tem;
1904       *op0_ptr = op0;
1905       *op1_ptr = op1;
1906       unsignedp0 = unsignedp1;
1907       unsignedp1 = temi;
1908       temi = real1;
1909       real1 = real2;
1910       real2 = temi;
1911
1912       switch (code)
1913         {
1914         case LT_EXPR:
1915           code = GT_EXPR;
1916           break;
1917         case GT_EXPR:
1918           code = LT_EXPR;
1919           break;
1920         case LE_EXPR:
1921           code = GE_EXPR;
1922           break;
1923         case GE_EXPR:
1924           code = LE_EXPR;
1925           break;
1926         default:
1927           break;
1928         }
1929       *rescode_ptr = code;
1930     }
1931
1932   /* If comparing an integer against a constant more bits wide,
1933      maybe we can deduce a value of 1 or 0 independent of the data.
1934      Or else truncate the constant now
1935      rather than extend the variable at run time.
1936
1937      This is only interesting if the constant is the wider arg.
1938      Also, it is not safe if the constant is unsigned and the
1939      variable arg is signed, since in this case the variable
1940      would be sign-extended and then regarded as unsigned.
1941      Our technique fails in this case because the lowest/highest
1942      possible unsigned results don't follow naturally from the
1943      lowest/highest possible values of the variable operand.
1944      For just EQ_EXPR and NE_EXPR there is another technique that
1945      could be used: see if the constant can be faithfully represented
1946      in the other operand's type, by truncating it and reextending it
1947      and see if that preserves the constant's value.  */
1948
1949   if (!real1 && !real2
1950       && TREE_CODE (primop1) == INTEGER_CST
1951       && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
1952     {
1953       int min_gt, max_gt, min_lt, max_lt;
1954       tree maxval, minval;
1955       /* 1 if comparison is nominally unsigned.  */
1956       int unsignedp = TREE_UNSIGNED (*restype_ptr);
1957       tree val;
1958
1959       type = c_common_signed_or_unsigned_type (unsignedp0,
1960                                                TREE_TYPE (primop0));
1961
1962       /* If TYPE is an enumeration, then we need to get its min/max
1963          values from it's underlying integral type, not the enumerated
1964          type itself.  */
1965       if (TREE_CODE (type) == ENUMERAL_TYPE)
1966         type = c_common_type_for_size (TYPE_PRECISION (type), unsignedp0);
1967
1968       maxval = TYPE_MAX_VALUE (type);
1969       minval = TYPE_MIN_VALUE (type);
1970
1971       if (unsignedp && !unsignedp0)
1972         *restype_ptr = c_common_signed_type (*restype_ptr);
1973
1974       if (TREE_TYPE (primop1) != *restype_ptr)
1975         primop1 = convert (*restype_ptr, primop1);
1976       if (type != *restype_ptr)
1977         {
1978           minval = convert (*restype_ptr, minval);
1979           maxval = convert (*restype_ptr, maxval);
1980         }
1981
1982       if (unsignedp && unsignedp0)
1983         {
1984           min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
1985           max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
1986           min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
1987           max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
1988         }
1989       else
1990         {
1991           min_gt = INT_CST_LT (primop1, minval);
1992           max_gt = INT_CST_LT (primop1, maxval);
1993           min_lt = INT_CST_LT (minval, primop1);
1994           max_lt = INT_CST_LT (maxval, primop1);
1995         }
1996
1997       val = 0;
1998       /* This used to be a switch, but Genix compiler can't handle that.  */
1999       if (code == NE_EXPR)
2000         {
2001           if (max_lt || min_gt)
2002             val = boolean_true_node;
2003         }
2004       else if (code == EQ_EXPR)
2005         {
2006           if (max_lt || min_gt)
2007             val = boolean_false_node;
2008         }
2009       else if (code == LT_EXPR)
2010         {
2011           if (max_lt)
2012             val = boolean_true_node;
2013           if (!min_lt)
2014             val = boolean_false_node;
2015         }
2016       else if (code == GT_EXPR)
2017         {
2018           if (min_gt)
2019             val = boolean_true_node;
2020           if (!max_gt)
2021             val = boolean_false_node;
2022         }
2023       else if (code == LE_EXPR)
2024         {
2025           if (!max_gt)
2026             val = boolean_true_node;
2027           if (min_gt)
2028             val = boolean_false_node;
2029         }
2030       else if (code == GE_EXPR)
2031         {
2032           if (!min_lt)
2033             val = boolean_true_node;
2034           if (max_lt)
2035             val = boolean_false_node;
2036         }
2037
2038       /* If primop0 was sign-extended and unsigned comparison specd,
2039          we did a signed comparison above using the signed type bounds.
2040          But the comparison we output must be unsigned.
2041
2042          Also, for inequalities, VAL is no good; but if the signed
2043          comparison had *any* fixed result, it follows that the
2044          unsigned comparison just tests the sign in reverse
2045          (positive values are LE, negative ones GE).
2046          So we can generate an unsigned comparison
2047          against an extreme value of the signed type.  */
2048
2049       if (unsignedp && !unsignedp0)
2050         {
2051           if (val != 0)
2052             switch (code)
2053               {
2054               case LT_EXPR:
2055               case GE_EXPR:
2056                 primop1 = TYPE_MIN_VALUE (type);
2057                 val = 0;
2058                 break;
2059
2060               case LE_EXPR:
2061               case GT_EXPR:
2062                 primop1 = TYPE_MAX_VALUE (type);
2063                 val = 0;
2064                 break;
2065
2066               default:
2067                 break;
2068               }
2069           type = c_common_unsigned_type (type);
2070         }
2071
2072       if (TREE_CODE (primop0) != INTEGER_CST)
2073         {
2074           if (val == boolean_false_node)
2075             warning ("comparison is always false due to limited range of data type");
2076           if (val == boolean_true_node)
2077             warning ("comparison is always true due to limited range of data type");
2078         }
2079
2080       if (val != 0)
2081         {
2082           /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2083           if (TREE_SIDE_EFFECTS (primop0))
2084             return build (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
2085           return val;
2086         }
2087
2088       /* Value is not predetermined, but do the comparison
2089          in the type of the operand that is not constant.
2090          TYPE is already properly set.  */
2091     }
2092   else if (real1 && real2
2093            && (TYPE_PRECISION (TREE_TYPE (primop0))
2094                == TYPE_PRECISION (TREE_TYPE (primop1))))
2095     type = TREE_TYPE (primop0);
2096
2097   /* If args' natural types are both narrower than nominal type
2098      and both extend in the same manner, compare them
2099      in the type of the wider arg.
2100      Otherwise must actually extend both to the nominal
2101      common type lest different ways of extending
2102      alter the result.
2103      (eg, (short)-1 == (unsigned short)-1  should be 0.)  */
2104
2105   else if (unsignedp0 == unsignedp1 && real1 == real2
2106            && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
2107            && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
2108     {
2109       type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
2110       type = c_common_signed_or_unsigned_type (unsignedp0
2111                                                || TREE_UNSIGNED (*restype_ptr),
2112                                                type);
2113       /* Make sure shorter operand is extended the right way
2114          to match the longer operand.  */
2115       primop0
2116         = convert (c_common_signed_or_unsigned_type (unsignedp0,
2117                                                      TREE_TYPE (primop0)),
2118                    primop0);
2119       primop1
2120         = convert (c_common_signed_or_unsigned_type (unsignedp1,
2121                                                      TREE_TYPE (primop1)),
2122                    primop1);
2123     }
2124   else
2125     {
2126       /* Here we must do the comparison on the nominal type
2127          using the args exactly as we received them.  */
2128       type = *restype_ptr;
2129       primop0 = op0;
2130       primop1 = op1;
2131
2132       if (!real1 && !real2 && integer_zerop (primop1)
2133           && TREE_UNSIGNED (*restype_ptr))
2134         {
2135           tree value = 0;
2136           switch (code)
2137             {
2138             case GE_EXPR:
2139               /* All unsigned values are >= 0, so we warn if extra warnings
2140                  are requested.  However, if OP0 is a constant that is
2141                  >= 0, the signedness of the comparison isn't an issue,
2142                  so suppress the warning.  */
2143               if (extra_warnings && !in_system_header
2144                   && ! (TREE_CODE (primop0) == INTEGER_CST
2145                         && ! TREE_OVERFLOW (convert (c_common_signed_type (type),
2146                                                      primop0))))
2147                 warning ("comparison of unsigned expression >= 0 is always true");
2148               value = boolean_true_node;
2149               break;
2150
2151             case LT_EXPR:
2152               if (extra_warnings && !in_system_header
2153                   && ! (TREE_CODE (primop0) == INTEGER_CST
2154                         && ! TREE_OVERFLOW (convert (c_common_signed_type (type),
2155                                                      primop0))))
2156                 warning ("comparison of unsigned expression < 0 is always false");
2157               value = boolean_false_node;
2158               break;
2159
2160             default:
2161               break;
2162             }
2163
2164           if (value != 0)
2165             {
2166               /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2167               if (TREE_SIDE_EFFECTS (primop0))
2168                 return build (COMPOUND_EXPR, TREE_TYPE (value),
2169                               primop0, value);
2170               return value;
2171             }
2172         }
2173     }
2174
2175   *op0_ptr = convert (type, primop0);
2176   *op1_ptr = convert (type, primop1);
2177
2178   *restype_ptr = boolean_type_node;
2179
2180   return 0;
2181 }
2182 \f
2183 /* Return a tree for the sum or difference (RESULTCODE says which)
2184    of pointer PTROP and integer INTOP.  */
2185
2186 tree
2187 pointer_int_sum (resultcode, ptrop, intop)
2188      enum tree_code resultcode;
2189      tree ptrop, intop;
2190 {
2191   tree size_exp;
2192
2193   tree result;
2194   tree folded;
2195
2196   /* The result is a pointer of the same type that is being added.  */
2197
2198   tree result_type = TREE_TYPE (ptrop);
2199
2200   if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
2201     {
2202       if (pedantic || warn_pointer_arith)
2203         pedwarn ("pointer of type `void *' used in arithmetic");
2204       size_exp = integer_one_node;
2205     }
2206   else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE)
2207     {
2208       if (pedantic || warn_pointer_arith)
2209         pedwarn ("pointer to a function used in arithmetic");
2210       size_exp = integer_one_node;
2211     }
2212   else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE)
2213     {
2214       if (pedantic || warn_pointer_arith)
2215         pedwarn ("pointer to member function used in arithmetic");
2216       size_exp = integer_one_node;
2217     }
2218   else if (TREE_CODE (TREE_TYPE (result_type)) == OFFSET_TYPE)
2219     {
2220       if (pedantic || warn_pointer_arith)
2221         pedwarn ("pointer to a member used in arithmetic");
2222       size_exp = integer_one_node;
2223     }
2224   else
2225     size_exp = size_in_bytes (TREE_TYPE (result_type));
2226
2227   /* If what we are about to multiply by the size of the elements
2228      contains a constant term, apply distributive law
2229      and multiply that constant term separately.
2230      This helps produce common subexpressions.  */
2231
2232   if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
2233       && ! TREE_CONSTANT (intop)
2234       && TREE_CONSTANT (TREE_OPERAND (intop, 1))
2235       && TREE_CONSTANT (size_exp)
2236       /* If the constant comes from pointer subtraction,
2237          skip this optimization--it would cause an error.  */
2238       && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
2239       /* If the constant is unsigned, and smaller than the pointer size,
2240          then we must skip this optimization.  This is because it could cause
2241          an overflow error if the constant is negative but INTOP is not.  */
2242       && (! TREE_UNSIGNED (TREE_TYPE (intop))
2243           || (TYPE_PRECISION (TREE_TYPE (intop))
2244               == TYPE_PRECISION (TREE_TYPE (ptrop)))))
2245     {
2246       enum tree_code subcode = resultcode;
2247       tree int_type = TREE_TYPE (intop);
2248       if (TREE_CODE (intop) == MINUS_EXPR)
2249         subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
2250       /* Convert both subexpression types to the type of intop,
2251          because weird cases involving pointer arithmetic
2252          can result in a sum or difference with different type args.  */
2253       ptrop = build_binary_op (subcode, ptrop,
2254                                convert (int_type, TREE_OPERAND (intop, 1)), 1);
2255       intop = convert (int_type, TREE_OPERAND (intop, 0));
2256     }
2257
2258   /* Convert the integer argument to a type the same size as sizetype
2259      so the multiply won't overflow spuriously.  */
2260
2261   if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype)
2262       || TREE_UNSIGNED (TREE_TYPE (intop)) != TREE_UNSIGNED (sizetype))
2263     intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype),
2264                                              TREE_UNSIGNED (sizetype)), intop);
2265
2266   /* Replace the integer argument with a suitable product by the object size.
2267      Do this multiplication as signed, then convert to the appropriate
2268      pointer type (actually unsigned integral).  */
2269
2270   intop = convert (result_type,
2271                    build_binary_op (MULT_EXPR, intop,
2272                                     convert (TREE_TYPE (intop), size_exp), 1));
2273
2274   /* Create the sum or difference.  */
2275
2276   result = build (resultcode, result_type, ptrop, intop);
2277
2278   folded = fold (result);
2279   if (folded == result)
2280     TREE_CONSTANT (folded) = TREE_CONSTANT (ptrop) & TREE_CONSTANT (intop);
2281   return folded;
2282 }
2283 \f
2284 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
2285    or validate its data type for an `if' or `while' statement or ?..: exp.
2286
2287    This preparation consists of taking the ordinary
2288    representation of an expression expr and producing a valid tree
2289    boolean expression describing whether expr is nonzero.  We could
2290    simply always do build_binary_op (NE_EXPR, expr, boolean_false_node, 1),
2291    but we optimize comparisons, &&, ||, and !.
2292
2293    The resulting type should always be `boolean_type_node'.  */
2294
2295 tree
2296 c_common_truthvalue_conversion (expr)
2297      tree expr;
2298 {
2299   if (TREE_CODE (expr) == ERROR_MARK)
2300     return expr;
2301
2302 #if 0 /* This appears to be wrong for C++.  */
2303   /* These really should return error_mark_node after 2.4 is stable.
2304      But not all callers handle ERROR_MARK properly.  */
2305   switch (TREE_CODE (TREE_TYPE (expr)))
2306     {
2307     case RECORD_TYPE:
2308       error ("struct type value used where scalar is required");
2309       return boolean_false_node;
2310
2311     case UNION_TYPE:
2312       error ("union type value used where scalar is required");
2313       return boolean_false_node;
2314
2315     case ARRAY_TYPE:
2316       error ("array type value used where scalar is required");
2317       return boolean_false_node;
2318
2319     default:
2320       break;
2321     }
2322 #endif /* 0 */
2323
2324   switch (TREE_CODE (expr))
2325     {
2326     case EQ_EXPR:
2327     case NE_EXPR: case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
2328     case TRUTH_ANDIF_EXPR:
2329     case TRUTH_ORIF_EXPR:
2330     case TRUTH_AND_EXPR:
2331     case TRUTH_OR_EXPR:
2332     case TRUTH_XOR_EXPR:
2333     case TRUTH_NOT_EXPR:
2334       TREE_TYPE (expr) = boolean_type_node;
2335       return expr;
2336
2337     case ERROR_MARK:
2338       return expr;
2339
2340     case INTEGER_CST:
2341       return integer_zerop (expr) ? boolean_false_node : boolean_true_node;
2342
2343     case REAL_CST:
2344       return real_zerop (expr) ? boolean_false_node : boolean_true_node;
2345
2346     case ADDR_EXPR:
2347       /* If we are taking the address of an external decl, it might be zero
2348          if it is weak, so we cannot optimize.  */
2349       if (DECL_P (TREE_OPERAND (expr, 0))
2350           && DECL_EXTERNAL (TREE_OPERAND (expr, 0)))
2351         break;
2352
2353       if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 0)))
2354         return build (COMPOUND_EXPR, boolean_type_node,
2355                       TREE_OPERAND (expr, 0), boolean_true_node);
2356       else
2357         return boolean_true_node;
2358
2359     case COMPLEX_EXPR:
2360       return build_binary_op ((TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
2361                                ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
2362                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)),
2363                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
2364                               0);
2365
2366     case NEGATE_EXPR:
2367     case ABS_EXPR:
2368     case FLOAT_EXPR:
2369     case FFS_EXPR:
2370       /* These don't change whether an object is non-zero or zero.  */
2371       return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
2372
2373     case LROTATE_EXPR:
2374     case RROTATE_EXPR:
2375       /* These don't change whether an object is zero or non-zero, but
2376          we can't ignore them if their second arg has side-effects.  */
2377       if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2378         return build (COMPOUND_EXPR, boolean_type_node, TREE_OPERAND (expr, 1),
2379                       c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)));
2380       else
2381         return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
2382
2383     case COND_EXPR:
2384       /* Distribute the conversion into the arms of a COND_EXPR.  */
2385       return fold (build (COND_EXPR, boolean_type_node, TREE_OPERAND (expr, 0),
2386                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
2387                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 2))));
2388
2389     case CONVERT_EXPR:
2390       /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
2391          since that affects how `default_conversion' will behave.  */
2392       if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
2393           || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
2394         break;
2395       /* fall through...  */
2396     case NOP_EXPR:
2397       /* If this is widening the argument, we can ignore it.  */
2398       if (TYPE_PRECISION (TREE_TYPE (expr))
2399           >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
2400         return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
2401       break;
2402
2403     case MINUS_EXPR:
2404       /* Perhaps reduce (x - y) != 0 to (x != y).  The expressions
2405          aren't guaranteed to the be same for modes that can represent
2406          infinity, since if x and y are both +infinity, or both
2407          -infinity, then x - y is not a number.
2408
2409          Note that this transformation is safe when x or y is NaN.
2410          (x - y) is then NaN, and both (x - y) != 0 and x != y will
2411          be false.  */
2412       if (HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (TREE_OPERAND (expr, 0)))))
2413         break;
2414       /* fall through...  */
2415     case BIT_XOR_EXPR:
2416       /* This and MINUS_EXPR can be changed into a comparison of the
2417          two objects.  */
2418       if (TREE_TYPE (TREE_OPERAND (expr, 0))
2419           == TREE_TYPE (TREE_OPERAND (expr, 1)))
2420         return build_binary_op (NE_EXPR, TREE_OPERAND (expr, 0),
2421                                 TREE_OPERAND (expr, 1), 1);
2422       return build_binary_op (NE_EXPR, TREE_OPERAND (expr, 0),
2423                               fold (build1 (NOP_EXPR,
2424                                             TREE_TYPE (TREE_OPERAND (expr, 0)),
2425                                             TREE_OPERAND (expr, 1))), 1);
2426
2427     case BIT_AND_EXPR:
2428       if (integer_onep (TREE_OPERAND (expr, 1))
2429           && TREE_TYPE (expr) != boolean_type_node)
2430         /* Using convert here would cause infinite recursion.  */
2431         return build1 (NOP_EXPR, boolean_type_node, expr);
2432       break;
2433
2434     case MODIFY_EXPR:
2435       if (warn_parentheses && C_EXP_ORIGINAL_CODE (expr) == MODIFY_EXPR)
2436         warning ("suggest parentheses around assignment used as truth value");
2437       break;
2438
2439     default:
2440       break;
2441     }
2442
2443   if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
2444     {
2445       tree t = save_expr (expr);
2446       return (build_binary_op
2447               ((TREE_SIDE_EFFECTS (expr)
2448                 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
2449         c_common_truthvalue_conversion (build_unary_op (REALPART_EXPR, t, 0)),
2450         c_common_truthvalue_conversion (build_unary_op (IMAGPART_EXPR, t, 0)),
2451                0));
2452     }
2453
2454   return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
2455 }
2456 \f
2457 static tree builtin_function_2 PARAMS ((const char *, const char *, tree, tree,
2458                                         int, enum built_in_class, int, int,
2459                                         int));
2460
2461 /* Make a variant type in the proper way for C/C++, propagating qualifiers
2462    down to the element type of an array.  */
2463
2464 tree
2465 c_build_qualified_type (type, type_quals)
2466      tree type;
2467      int type_quals;
2468 {
2469   /* A restrict-qualified pointer type must be a pointer to object or
2470      incomplete type.  Note that the use of POINTER_TYPE_P also allows
2471      REFERENCE_TYPEs, which is appropriate for C++.  Unfortunately,
2472      the C++ front-end also use POINTER_TYPE for pointer-to-member
2473      values, so even though it should be illegal to use `restrict'
2474      with such an entity we don't flag that here.  Thus, special case
2475      code for that case is required in the C++ front-end.  */
2476   if ((type_quals & TYPE_QUAL_RESTRICT)
2477       && (!POINTER_TYPE_P (type)
2478           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type))))
2479     {
2480       error ("invalid use of `restrict'");
2481       type_quals &= ~TYPE_QUAL_RESTRICT;
2482     }
2483
2484   if (TREE_CODE (type) == ARRAY_TYPE)
2485     return build_array_type (c_build_qualified_type (TREE_TYPE (type),
2486                                                      type_quals),
2487                              TYPE_DOMAIN (type));
2488   return build_qualified_type (type, type_quals);
2489 }
2490
2491 /* Apply the TYPE_QUALS to the new DECL.  */
2492
2493 void
2494 c_apply_type_quals_to_decl (type_quals, decl)
2495      int type_quals;
2496      tree decl;
2497 {
2498   if ((type_quals & TYPE_QUAL_CONST)
2499       || (TREE_TYPE (decl)
2500           && TREE_CODE (TREE_TYPE (decl)) == REFERENCE_TYPE))
2501     TREE_READONLY (decl) = 1;
2502   if (type_quals & TYPE_QUAL_VOLATILE)
2503     {
2504       TREE_SIDE_EFFECTS (decl) = 1;
2505       TREE_THIS_VOLATILE (decl) = 1;
2506     }
2507   if (type_quals & TYPE_QUAL_RESTRICT)
2508     {
2509       if (!TREE_TYPE (decl)
2510           || !POINTER_TYPE_P (TREE_TYPE (decl))
2511           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (TREE_TYPE (decl))))
2512         error ("invalid use of `restrict'");
2513       else if (flag_strict_aliasing)
2514         /* Indicate we need to make a unique alias set for this pointer.
2515            We can't do it here because it might be pointing to an
2516            incomplete type.  */
2517         DECL_POINTER_ALIAS_SET (decl) = -2;
2518     }
2519 }
2520
2521 /* Return the typed-based alias set for T, which may be an expression
2522    or a type.  Return -1 if we don't do anything special.  */
2523
2524 HOST_WIDE_INT
2525 c_common_get_alias_set (t)
2526      tree t;
2527 {
2528   tree u;
2529
2530   /* Permit type-punning when accessing a union, provided the access
2531      is directly through the union.  For example, this code does not
2532      permit taking the address of a union member and then storing
2533      through it.  Even the type-punning allowed here is a GCC
2534      extension, albeit a common and useful one; the C standard says
2535      that such accesses have implementation-defined behavior.  */
2536   for (u = t;
2537        TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
2538        u = TREE_OPERAND (u, 0))
2539     if (TREE_CODE (u) == COMPONENT_REF
2540         && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
2541       return 0;
2542
2543   /* That's all the expressions we handle specially.  */
2544   if (! TYPE_P (t))
2545     return -1;
2546
2547   /* The C standard guarantess that any object may be accessed via an
2548      lvalue that has character type.  */
2549   if (t == char_type_node
2550       || t == signed_char_type_node
2551       || t == unsigned_char_type_node)
2552     return 0;
2553
2554   /* If it has the may_alias attribute, it can alias anything.  */
2555   if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (t)))
2556     return 0;
2557
2558   /* The C standard specifically allows aliasing between signed and
2559      unsigned variants of the same type.  We treat the signed
2560      variant as canonical.  */
2561   if (TREE_CODE (t) == INTEGER_TYPE && TREE_UNSIGNED (t))
2562     {
2563       tree t1 = c_common_signed_type (t);
2564
2565       /* t1 == t can happen for boolean nodes which are always unsigned.  */
2566       if (t1 != t)
2567         return get_alias_set (t1);
2568     }
2569   else if (POINTER_TYPE_P (t))
2570     {
2571       tree t1;
2572
2573       /* Unfortunately, there is no canonical form of a pointer type.
2574          In particular, if we have `typedef int I', then `int *', and
2575          `I *' are different types.  So, we have to pick a canonical
2576          representative.  We do this below.
2577
2578          Technically, this approach is actually more conservative that
2579          it needs to be.  In particular, `const int *' and `int *'
2580          should be in different alias sets, according to the C and C++
2581          standard, since their types are not the same, and so,
2582          technically, an `int **' and `const int **' cannot point at
2583          the same thing.
2584
2585          But, the standard is wrong.  In particular, this code is
2586          legal C++:
2587
2588             int *ip;
2589             int **ipp = &ip;
2590             const int* const* cipp = &ipp;
2591
2592          And, it doesn't make sense for that to be legal unless you
2593          can dereference IPP and CIPP.  So, we ignore cv-qualifiers on
2594          the pointed-to types.  This issue has been reported to the
2595          C++ committee.  */
2596       t1 = build_type_no_quals (t);
2597       if (t1 != t)
2598         return get_alias_set (t1);
2599     }
2600
2601   return -1;
2602 }
2603 \f
2604 /* Implement the __alignof keyword: Return the minimum required
2605    alignment of TYPE, measured in bytes.  */
2606
2607 tree
2608 c_alignof (type)
2609      tree type;
2610 {
2611   enum tree_code code = TREE_CODE (type);
2612   tree t;
2613
2614   /* In C++, sizeof applies to the referent.  Handle alignof the same way.  */
2615   if (code == REFERENCE_TYPE)
2616     {
2617       type = TREE_TYPE (type);
2618       code = TREE_CODE (type);
2619     }
2620
2621   if (code == FUNCTION_TYPE)
2622     t = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);
2623   else if (code == VOID_TYPE || code == ERROR_MARK)
2624     t = size_one_node;
2625   else if (!COMPLETE_TYPE_P (type))
2626     {
2627       error ("__alignof__ applied to an incomplete type");
2628       t = size_zero_node;
2629     }
2630   else
2631     t = size_int (TYPE_ALIGN (type) / BITS_PER_UNIT);
2632
2633   return fold (build1 (NOP_EXPR, c_size_type_node, t));
2634 }
2635
2636 /* Implement the __alignof keyword: Return the minimum required
2637    alignment of EXPR, measured in bytes.  For VAR_DECL's and
2638    FIELD_DECL's return DECL_ALIGN (which can be set from an
2639    "aligned" __attribute__ specification).  */
2640
2641 tree
2642 c_alignof_expr (expr)
2643      tree expr;
2644 {
2645   tree t;
2646
2647   if (TREE_CODE (expr) == VAR_DECL)
2648     t = size_int (DECL_ALIGN (expr) / BITS_PER_UNIT);
2649
2650   else if (TREE_CODE (expr) == COMPONENT_REF
2651            && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1)))
2652     {
2653       error ("`__alignof' applied to a bit-field");
2654       t = size_one_node;
2655     }
2656   else if (TREE_CODE (expr) == COMPONENT_REF
2657            && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL)
2658     t = size_int (DECL_ALIGN (TREE_OPERAND (expr, 1)) / BITS_PER_UNIT);
2659
2660   else if (TREE_CODE (expr) == INDIRECT_REF)
2661     {
2662       tree t = TREE_OPERAND (expr, 0);
2663       tree best = t;
2664       int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
2665
2666       while (TREE_CODE (t) == NOP_EXPR
2667              && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE)
2668         {
2669           int thisalign;
2670
2671           t = TREE_OPERAND (t, 0);
2672           thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
2673           if (thisalign > bestalign)
2674             best = t, bestalign = thisalign;
2675         }
2676       return c_alignof (TREE_TYPE (TREE_TYPE (best)));
2677     }
2678   else
2679     return c_alignof (TREE_TYPE (expr));
2680
2681   return fold (build1 (NOP_EXPR, c_size_type_node, t));
2682 }
2683 \f
2684 /* Build tree nodes and builtin functions common to both C and C++ language
2685    frontends.  */
2686
2687 void
2688 c_common_nodes_and_builtins ()
2689 {
2690   enum builtin_type
2691   {
2692 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
2693 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
2694 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
2695 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
2696 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
2697 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
2698 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
2699 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
2700 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
2701 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
2702 #include "builtin-types.def"
2703 #undef DEF_PRIMITIVE_TYPE
2704 #undef DEF_FUNCTION_TYPE_0
2705 #undef DEF_FUNCTION_TYPE_1
2706 #undef DEF_FUNCTION_TYPE_2
2707 #undef DEF_FUNCTION_TYPE_3
2708 #undef DEF_FUNCTION_TYPE_4
2709 #undef DEF_FUNCTION_TYPE_VAR_0
2710 #undef DEF_FUNCTION_TYPE_VAR_1
2711 #undef DEF_FUNCTION_TYPE_VAR_2
2712 #undef DEF_POINTER_TYPE
2713     BT_LAST
2714   };
2715
2716   typedef enum builtin_type builtin_type;
2717
2718   tree builtin_types[(int) BT_LAST];
2719   int wchar_type_size;
2720   tree array_domain_type;
2721   tree va_list_ref_type_node;
2722   tree va_list_arg_type_node;
2723
2724   /* Define `int' and `char' first so that dbx will output them first.  */
2725   record_builtin_type (RID_INT, NULL, integer_type_node);
2726   record_builtin_type (RID_CHAR, "char", char_type_node);
2727
2728   /* `signed' is the same as `int'.  FIXME: the declarations of "signed",
2729      "unsigned long", "long long unsigned" and "unsigned short" were in C++
2730      but not C.  Are the conditionals here needed?  */
2731   if (c_language == clk_cplusplus)
2732     record_builtin_type (RID_SIGNED, NULL, integer_type_node);
2733   record_builtin_type (RID_LONG, "long int", long_integer_type_node);
2734   record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
2735   record_builtin_type (RID_MAX, "long unsigned int",
2736                        long_unsigned_type_node);
2737   if (c_language == clk_cplusplus)
2738     record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
2739   record_builtin_type (RID_MAX, "long long int",
2740                        long_long_integer_type_node);
2741   record_builtin_type (RID_MAX, "long long unsigned int",
2742                        long_long_unsigned_type_node);
2743   if (c_language == clk_cplusplus)
2744     record_builtin_type (RID_MAX, "long long unsigned",
2745                          long_long_unsigned_type_node);
2746   record_builtin_type (RID_SHORT, "short int", short_integer_type_node);
2747   record_builtin_type (RID_MAX, "short unsigned int",
2748                        short_unsigned_type_node);
2749   if (c_language == clk_cplusplus)
2750     record_builtin_type (RID_MAX, "unsigned short",
2751                          short_unsigned_type_node);
2752
2753   /* Define both `signed char' and `unsigned char'.  */
2754   record_builtin_type (RID_MAX, "signed char", signed_char_type_node);
2755   record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node);
2756
2757   /* These are types that c_common_type_for_size and
2758      c_common_type_for_mode use.  */
2759   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL, NULL_TREE,
2760                                             intQI_type_node));
2761   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL, NULL_TREE,
2762                                             intHI_type_node));
2763   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL, NULL_TREE,
2764                                             intSI_type_node));
2765   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL, NULL_TREE,
2766                                             intDI_type_node));
2767 #if HOST_BITS_PER_WIDE_INT >= 64
2768   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL,
2769                                             get_identifier ("__int128_t"),
2770                                             intTI_type_node));
2771 #endif
2772   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL, NULL_TREE,
2773                                             unsigned_intQI_type_node));
2774   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL, NULL_TREE,
2775                                             unsigned_intHI_type_node));
2776   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL, NULL_TREE,
2777                                             unsigned_intSI_type_node));
2778   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL, NULL_TREE,
2779                                             unsigned_intDI_type_node));
2780 #if HOST_BITS_PER_WIDE_INT >= 64
2781   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL,
2782                                             get_identifier ("__uint128_t"),
2783                                             unsigned_intTI_type_node));
2784 #endif
2785
2786   /* Create the widest literal types.  */
2787   widest_integer_literal_type_node
2788     = make_signed_type (HOST_BITS_PER_WIDE_INT * 2);
2789   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL, NULL_TREE,
2790                                             widest_integer_literal_type_node));
2791
2792   widest_unsigned_literal_type_node
2793     = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2);
2794   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL, NULL_TREE,
2795                                             widest_unsigned_literal_type_node));
2796
2797   /* `unsigned long' is the standard type for sizeof.
2798      Note that stddef.h uses `unsigned long',
2799      and this must agree, even if long and int are the same size.  */
2800   c_size_type_node =
2801     TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE)));
2802   signed_size_type_node = c_common_signed_type (c_size_type_node);
2803   set_sizetype (c_size_type_node);
2804
2805   build_common_tree_nodes_2 (flag_short_double);
2806
2807   record_builtin_type (RID_FLOAT, NULL, float_type_node);
2808   record_builtin_type (RID_DOUBLE, NULL, double_type_node);
2809   record_builtin_type (RID_MAX, "long double", long_double_type_node);
2810
2811   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL,
2812                                             get_identifier ("complex int"),
2813                                             complex_integer_type_node));
2814   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL,
2815                                             get_identifier ("complex float"),
2816                                             complex_float_type_node));
2817   (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL,
2818                                             get_identifier ("complex double"),
2819                                             complex_double_type_node));
2820   (*lang_hooks.decls.pushdecl)
2821     (build_decl (TYPE_DECL, get_identifier ("complex long double"),
2822                  complex_long_double_type_node));
2823
2824   /* Types which are common to the fortran compiler and libf2c.  When
2825      changing these, you also need to be concerned with f/com.h.  */
2826
2827   if (TYPE_PRECISION (float_type_node)
2828       == TYPE_PRECISION (long_integer_type_node))
2829     {
2830       g77_integer_type_node = long_integer_type_node;
2831       g77_uinteger_type_node = long_unsigned_type_node;
2832     }
2833   else if (TYPE_PRECISION (float_type_node)
2834            == TYPE_PRECISION (integer_type_node))
2835     {
2836       g77_integer_type_node = integer_type_node;
2837       g77_uinteger_type_node = unsigned_type_node;
2838     }
2839   else
2840     g77_integer_type_node = g77_uinteger_type_node = NULL_TREE;
2841
2842   if (g77_integer_type_node != NULL_TREE)
2843     {
2844       (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL,
2845                                                 get_identifier ("__g77_integer"),
2846                                                 g77_integer_type_node));
2847       (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL,
2848                                                 get_identifier ("__g77_uinteger"),
2849                                                 g77_uinteger_type_node));
2850     }
2851
2852   if (TYPE_PRECISION (float_type_node) * 2
2853       == TYPE_PRECISION (long_integer_type_node))
2854     {
2855       g77_longint_type_node = long_integer_type_node;
2856       g77_ulongint_type_node = long_unsigned_type_node;
2857     }
2858   else if (TYPE_PRECISION (float_type_node) * 2
2859            == TYPE_PRECISION (long_long_integer_type_node))
2860     {
2861       g77_longint_type_node = long_long_integer_type_node;
2862       g77_ulongint_type_node = long_long_unsigned_type_node;
2863     }
2864   else
2865     g77_longint_type_node = g77_ulongint_type_node = NULL_TREE;
2866
2867   if (g77_longint_type_node != NULL_TREE)
2868     {
2869       (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL,
2870                                                 get_identifier ("__g77_longint"),
2871                                                 g77_longint_type_node));
2872       (*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL,
2873                                                 get_identifier ("__g77_ulongint"),
2874                                                 g77_ulongint_type_node));
2875     }
2876
2877   record_builtin_type (RID_VOID, NULL, void_type_node);
2878
2879   void_zero_node = build_int_2 (0, 0);
2880   TREE_TYPE (void_zero_node) = void_type_node;
2881
2882   void_list_node = build_void_list_node ();
2883
2884   /* Make a type to be the domain of a few array types
2885      whose domains don't really matter.
2886      200 is small enough that it always fits in size_t
2887      and large enough that it can hold most function names for the
2888      initializations of __FUNCTION__ and __PRETTY_FUNCTION__.  */
2889   array_domain_type = build_index_type (size_int (200));
2890
2891   /* Make a type for arrays of characters.
2892      With luck nothing will ever really depend on the length of this
2893      array type.  */
2894   char_array_type_node
2895     = build_array_type (char_type_node, array_domain_type);
2896
2897   /* Likewise for arrays of ints.  */
2898   int_array_type_node
2899     = build_array_type (integer_type_node, array_domain_type);
2900
2901   string_type_node = build_pointer_type (char_type_node);
2902   const_string_type_node
2903     = build_pointer_type (build_qualified_type
2904                           (char_type_node, TYPE_QUAL_CONST));
2905
2906   (*targetm.init_builtins) ();
2907
2908   /* This is special for C++ so functions can be overloaded.  */
2909   wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE);
2910   wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node));
2911   wchar_type_size = TYPE_PRECISION (wchar_type_node);
2912   if (c_language == clk_cplusplus)
2913     {
2914       if (TREE_UNSIGNED (wchar_type_node))
2915         wchar_type_node = make_unsigned_type (wchar_type_size);
2916       else
2917         wchar_type_node = make_signed_type (wchar_type_size);
2918       record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node);
2919     }
2920   else
2921     {
2922       signed_wchar_type_node = c_common_signed_type (wchar_type_node);
2923       unsigned_wchar_type_node = c_common_unsigned_type (wchar_type_node);
2924     }
2925
2926   /* This is for wide string constants.  */
2927   wchar_array_type_node
2928     = build_array_type (wchar_type_node, array_domain_type);
2929
2930   wint_type_node =
2931     TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE)));
2932
2933   intmax_type_node =
2934     TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE)));
2935   uintmax_type_node =
2936     TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE)));
2937
2938   default_function_type = build_function_type (integer_type_node, NULL_TREE);
2939   ptrdiff_type_node
2940     = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE)));
2941   unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node);
2942
2943   (*lang_hooks.decls.pushdecl)
2944     (build_decl (TYPE_DECL, get_identifier ("__builtin_va_list"),
2945                  va_list_type_node));
2946
2947   (*lang_hooks.decls.pushdecl)
2948     (build_decl (TYPE_DECL, get_identifier ("__builtin_ptrdiff_t"),
2949                  ptrdiff_type_node));
2950
2951   (*lang_hooks.decls.pushdecl)
2952     (build_decl (TYPE_DECL, get_identifier ("__builtin_size_t"),
2953                  sizetype));
2954
2955   if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
2956     {
2957       va_list_arg_type_node = va_list_ref_type_node =
2958         build_pointer_type (TREE_TYPE (va_list_type_node));
2959     }
2960   else
2961     {
2962       va_list_arg_type_node = va_list_type_node;
2963       va_list_ref_type_node = build_reference_type (va_list_type_node);
2964     }
2965
2966 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
2967   builtin_types[(int) ENUM] = VALUE;
2968 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN)               \
2969   builtin_types[(int) ENUM]                             \
2970     = build_function_type (builtin_types[(int) RETURN], \
2971                            void_list_node);
2972 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1)                         \
2973   builtin_types[(int) ENUM]                                             \
2974     = build_function_type (builtin_types[(int) RETURN],                 \
2975                            tree_cons (NULL_TREE,                        \
2976                                       builtin_types[(int) ARG1],        \
2977                                       void_list_node));
2978 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2)   \
2979   builtin_types[(int) ENUM]                             \
2980     = build_function_type                               \
2981       (builtin_types[(int) RETURN],                     \
2982        tree_cons (NULL_TREE,                            \
2983                   builtin_types[(int) ARG1],            \
2984                   tree_cons (NULL_TREE,                 \
2985                              builtin_types[(int) ARG2], \
2986                              void_list_node)));
2987 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3)              \
2988   builtin_types[(int) ENUM]                                              \
2989     = build_function_type                                                \
2990       (builtin_types[(int) RETURN],                                      \
2991        tree_cons (NULL_TREE,                                             \
2992                   builtin_types[(int) ARG1],                             \
2993                   tree_cons (NULL_TREE,                                  \
2994                              builtin_types[(int) ARG2],                  \
2995                              tree_cons (NULL_TREE,                       \
2996                                         builtin_types[(int) ARG3],       \
2997                                         void_list_node))));
2998 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4)       \
2999   builtin_types[(int) ENUM]                                             \
3000     = build_function_type                                               \
3001       (builtin_types[(int) RETURN],                                     \
3002        tree_cons (NULL_TREE,                                            \
3003                   builtin_types[(int) ARG1],                            \
3004                   tree_cons (NULL_TREE,                                 \
3005                              builtin_types[(int) ARG2],                 \
3006                              tree_cons                                  \
3007                              (NULL_TREE,                                \
3008                               builtin_types[(int) ARG3],                \
3009                               tree_cons (NULL_TREE,                     \
3010                                          builtin_types[(int) ARG4],     \
3011                                          void_list_node)))));
3012 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN)                           \
3013   builtin_types[(int) ENUM]                                             \
3014     = build_function_type (builtin_types[(int) RETURN], NULL_TREE);
3015 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1)                      \
3016    builtin_types[(int) ENUM]                                             \
3017     = build_function_type (builtin_types[(int) RETURN],                  \
3018                            tree_cons (NULL_TREE,                         \
3019                                       builtin_types[(int) ARG1],         \
3020                                       NULL_TREE));
3021
3022 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2)       \
3023    builtin_types[(int) ENUM]                                    \
3024     = build_function_type                                       \
3025       (builtin_types[(int) RETURN],                             \
3026        tree_cons (NULL_TREE,                                    \
3027                   builtin_types[(int) ARG1],                    \
3028                   tree_cons (NULL_TREE,                         \
3029                              builtin_types[(int) ARG2],         \
3030                              NULL_TREE)));
3031 #define DEF_POINTER_TYPE(ENUM, TYPE)                    \
3032   builtin_types[(int) ENUM]                             \
3033     = build_pointer_type (builtin_types[(int) TYPE]);
3034 #include "builtin-types.def"
3035 #undef DEF_PRIMITIVE_TYPE
3036 #undef DEF_FUNCTION_TYPE_1
3037 #undef DEF_FUNCTION_TYPE_2
3038 #undef DEF_FUNCTION_TYPE_3
3039 #undef DEF_FUNCTION_TYPE_4
3040 #undef DEF_FUNCTION_TYPE_VAR_0
3041 #undef DEF_FUNCTION_TYPE_VAR_1
3042 #undef DEF_POINTER_TYPE
3043
3044 #define DEF_BUILTIN(ENUM, NAME, CLASS,                                  \
3045                     TYPE, LIBTYPE, BOTH_P, FALLBACK_P, NONANSI_P)       \
3046   if (NAME)                                                             \
3047     {                                                                   \
3048       tree decl;                                                        \
3049                                                                         \
3050       if (strncmp (NAME, "__builtin_", strlen ("__builtin_")) != 0)     \
3051         abort ();                                                       \
3052                                                                         \
3053       if (!BOTH_P)                                                      \
3054         decl = builtin_function (NAME, builtin_types[TYPE], ENUM,       \
3055                                  CLASS,                                 \
3056                                  (FALLBACK_P                            \
3057                                   ? (NAME + strlen ("__builtin_"))      \
3058                                   : NULL));                             \
3059       else                                                              \
3060         decl = builtin_function_2 (NAME,                                \
3061                                    NAME + strlen ("__builtin_"),        \
3062                                    builtin_types[TYPE],                 \
3063                                    builtin_types[LIBTYPE],              \
3064                                    ENUM,                                \
3065                                    CLASS,                               \
3066                                    FALLBACK_P,                          \
3067                                    NONANSI_P,                           \
3068                                    /*noreturn_p=*/0);                   \
3069                                                                         \
3070       built_in_decls[(int) ENUM] = decl;                                \
3071     }
3072 #include "builtins.def"
3073 #undef DEF_BUILTIN
3074
3075   /* Declare _exit and _Exit just to mark them as non-returning.  */
3076   builtin_function_2 (NULL, "_exit", NULL_TREE,
3077                       builtin_types[BT_FN_VOID_INT],
3078                       0, NOT_BUILT_IN, 0, 1, 1);
3079   builtin_function_2 (NULL, "_Exit", NULL_TREE,
3080                       builtin_types[BT_FN_VOID_INT],
3081                       0, NOT_BUILT_IN, 0, !flag_isoc99, 1);
3082
3083   /* Declare these functions non-returning
3084      to avoid spurious "control drops through" warnings.  */
3085   builtin_function_2 (NULL, "abort",
3086                       NULL_TREE, ((c_language == clk_cplusplus)
3087                                   ? builtin_types[BT_FN_VOID]
3088                                   : builtin_types[BT_FN_VOID_VAR]),
3089                       0, NOT_BUILT_IN, 0, 0, 1);
3090
3091   builtin_function_2 (NULL, "exit",
3092                       NULL_TREE, ((c_language == clk_cplusplus)
3093                                   ? builtin_types[BT_FN_VOID_INT]
3094                                   : builtin_types[BT_FN_VOID_VAR]),
3095                       0, NOT_BUILT_IN, 0, 0, 1);
3096
3097   main_identifier_node = get_identifier ("main");
3098 }
3099
3100 tree
3101 build_va_arg (expr, type)
3102      tree expr, type;
3103 {
3104   return build1 (VA_ARG_EXPR, type, expr);
3105 }
3106
3107
3108 /* Linked list of disabled built-in functions.  */
3109
3110 typedef struct disabled_builtin
3111 {
3112   const char *name;
3113   struct disabled_builtin *next;
3114 } disabled_builtin;
3115 static disabled_builtin *disabled_builtins = NULL;
3116
3117 static bool builtin_function_disabled_p PARAMS ((const char *));
3118
3119 /* Disable a built-in function specified by -fno-builtin-NAME.  If NAME
3120    begins with "__builtin_", give an error.  */
3121
3122 void
3123 disable_builtin_function (name)
3124      const char *name;
3125 {
3126   if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
3127     error ("cannot disable built-in function `%s'", name);
3128   else
3129     {
3130       disabled_builtin *new = xmalloc (sizeof (disabled_builtin));
3131       new->name = name;
3132       new->next = disabled_builtins;
3133       disabled_builtins = new;
3134     }
3135 }
3136
3137
3138 /* Return true if the built-in function NAME has been disabled, false
3139    otherwise.  */
3140
3141 static bool
3142 builtin_function_disabled_p (name)
3143      const char *name;
3144 {
3145   disabled_builtin *p;
3146   for (p = disabled_builtins; p != NULL; p = p->next)
3147     {
3148       if (strcmp (name, p->name) == 0)
3149         return true;
3150     }
3151   return false;
3152 }
3153
3154
3155 /* Possibly define a builtin function with one or two names.  BUILTIN_NAME
3156    is an __builtin_-prefixed name; NAME is the ordinary name; one or both
3157    of these may be NULL (though both being NULL is useless).
3158    BUILTIN_TYPE is the type of the __builtin_-prefixed function;
3159    TYPE is the type of the function with the ordinary name.  These
3160    may differ if the ordinary name is declared with a looser type to avoid
3161    conflicts with headers.  FUNCTION_CODE and CLASS are as for
3162    builtin_function.  If LIBRARY_NAME_P is nonzero, NAME is passed as
3163    the LIBRARY_NAME parameter to builtin_function when declaring BUILTIN_NAME.
3164    If NONANSI_P is nonzero, the name NAME is treated as a non-ANSI name; if
3165    NORETURN_P is nonzero, the function is marked as non-returning.
3166    Returns the declaration of BUILTIN_NAME, if any, otherwise
3167    the declaration of NAME.  Does not declare NAME if flag_no_builtin,
3168    or if NONANSI_P and flag_no_nonansi_builtin.  */
3169
3170 static tree
3171 builtin_function_2 (builtin_name, name, builtin_type, type, function_code,
3172                     class, library_name_p, nonansi_p, noreturn_p)
3173      const char *builtin_name;
3174      const char *name;
3175      tree builtin_type;
3176      tree type;
3177      int function_code;
3178      enum built_in_class class;
3179      int library_name_p;
3180      int nonansi_p;
3181      int noreturn_p;
3182 {
3183   tree bdecl = NULL_TREE;
3184   tree decl = NULL_TREE;
3185   if (builtin_name != 0)
3186     {
3187       bdecl = builtin_function (builtin_name, builtin_type, function_code,
3188                                 class, library_name_p ? name : NULL);
3189       if (noreturn_p)
3190         {
3191           TREE_THIS_VOLATILE (bdecl) = 1;
3192           TREE_SIDE_EFFECTS (bdecl) = 1;
3193         }
3194     }
3195   if (name != 0 && !flag_no_builtin && !builtin_function_disabled_p (name)
3196       && !(nonansi_p && flag_no_nonansi_builtin))
3197     {
3198       decl = builtin_function (name, type, function_code, class, NULL);
3199       if (nonansi_p)
3200         DECL_BUILT_IN_NONANSI (decl) = 1;
3201       if (noreturn_p)
3202         {
3203           TREE_THIS_VOLATILE (decl) = 1;
3204           TREE_SIDE_EFFECTS (decl) = 1;
3205         }
3206     }
3207   return (bdecl != 0 ? bdecl : decl);
3208 }
3209 \f
3210 /* Nonzero if the type T promotes to int.  This is (nearly) the
3211    integral promotions defined in ISO C99 6.3.1.1/2.  */
3212
3213 bool
3214 c_promoting_integer_type_p (t)
3215      tree t;
3216 {
3217   switch (TREE_CODE (t))
3218     {
3219     case INTEGER_TYPE:
3220       return (TYPE_MAIN_VARIANT (t) == char_type_node
3221               || TYPE_MAIN_VARIANT (t) == signed_char_type_node
3222               || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node
3223               || TYPE_MAIN_VARIANT (t) == short_integer_type_node
3224               || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node
3225               || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node));
3226
3227     case ENUMERAL_TYPE:
3228       /* ??? Technically all enumerations not larger than an int
3229          promote to an int.  But this is used along code paths
3230          that only want to notice a size change.  */
3231       return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node);
3232
3233     case BOOLEAN_TYPE:
3234       return 1;
3235
3236     default:
3237       return 0;
3238     }
3239 }
3240
3241 /* Return 1 if PARMS specifies a fixed number of parameters
3242    and none of their types is affected by default promotions.  */
3243
3244 int
3245 self_promoting_args_p (parms)
3246      tree parms;
3247 {
3248   tree t;
3249   for (t = parms; t; t = TREE_CHAIN (t))
3250     {
3251       tree type = TREE_VALUE (t);
3252
3253       if (TREE_CHAIN (t) == 0 && type != void_type_node)
3254         return 0;
3255
3256       if (type == 0)
3257         return 0;
3258
3259       if (TYPE_MAIN_VARIANT (type) == float_type_node)
3260         return 0;
3261
3262       if (c_promoting_integer_type_p (type))
3263         return 0;
3264     }
3265   return 1;
3266 }
3267
3268 /* Recursively examines the array elements of TYPE, until a non-array
3269    element type is found.  */
3270
3271 tree
3272 strip_array_types (type)
3273      tree type;
3274 {
3275   while (TREE_CODE (type) == ARRAY_TYPE)
3276     type = TREE_TYPE (type);
3277
3278   return type;
3279 }
3280
3281 static tree expand_unordered_cmp PARAMS ((tree, tree, enum tree_code,
3282                                           enum tree_code));
3283
3284 /* Expand a call to an unordered comparison function such as
3285    __builtin_isgreater().  FUNCTION is the function's declaration and
3286    PARAMS a list of the values passed.  For __builtin_isunordered(),
3287    UNORDERED_CODE is UNORDERED_EXPR and ORDERED_CODE is NOP_EXPR.  In
3288    other cases, UNORDERED_CODE and ORDERED_CODE are comparison codes
3289    that give the opposite of the desired result.  UNORDERED_CODE is
3290    used for modes that can hold NaNs and ORDERED_CODE is used for the
3291    rest.  */
3292
3293 static tree
3294 expand_unordered_cmp (function, params, unordered_code, ordered_code)
3295      tree function, params;
3296      enum tree_code unordered_code, ordered_code;
3297 {
3298   tree arg0, arg1, type;
3299   enum tree_code code0, code1;
3300
3301   /* Check that we have exactly two arguments.  */
3302   if (params == 0 || TREE_CHAIN (params) == 0)
3303     {
3304       error ("too few arguments to function `%s'",
3305              IDENTIFIER_POINTER (DECL_NAME (function)));
3306       return error_mark_node;
3307     }
3308   else if (TREE_CHAIN (TREE_CHAIN (params)) != 0)
3309     {
3310       error ("too many arguments to function `%s'",
3311              IDENTIFIER_POINTER (DECL_NAME (function)));
3312       return error_mark_node;
3313     }
3314
3315   arg0 = TREE_VALUE (params);
3316   arg1 = TREE_VALUE (TREE_CHAIN (params));
3317
3318   code0 = TREE_CODE (TREE_TYPE (arg0));
3319   code1 = TREE_CODE (TREE_TYPE (arg1));
3320
3321   /* Make sure that the arguments have a common type of REAL.  */
3322   type = 0;
3323   if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3324       && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3325     type = common_type (TREE_TYPE (arg0), TREE_TYPE (arg1));
3326
3327   if (type == 0 || TREE_CODE (type) != REAL_TYPE)
3328     {
3329       error ("non-floating-point argument to function `%s'",
3330              IDENTIFIER_POINTER (DECL_NAME (function)));
3331       return error_mark_node;
3332     }
3333
3334   if (unordered_code == UNORDERED_EXPR)
3335     {
3336       if (MODE_HAS_NANS (TYPE_MODE (type)))
3337         return build_binary_op (unordered_code,
3338                                 convert (type, arg0),
3339                                 convert (type, arg1),
3340                                 0);
3341       else
3342         return integer_zero_node;
3343     }
3344
3345   return build_unary_op (TRUTH_NOT_EXPR,
3346                          build_binary_op (MODE_HAS_NANS (TYPE_MODE (type))
3347                                           ? unordered_code
3348                                           : ordered_code,
3349                                           convert (type, arg0),
3350                                           convert (type, arg1),
3351                                           0),
3352                          0);
3353 }
3354
3355
3356 /* Recognize certain built-in functions so we can make tree-codes
3357    other than CALL_EXPR.  We do this when it enables fold-const.c
3358    to do something useful.  */
3359 /* ??? By rights this should go in builtins.c, but only C and C++
3360    implement build_{binary,unary}_op.  Not exactly sure what bits
3361    of functionality are actually needed from those functions, or
3362    where the similar functionality exists in the other front ends.  */
3363
3364 tree
3365 expand_tree_builtin (function, params, coerced_params)
3366      tree function, params, coerced_params;
3367 {
3368   if (DECL_BUILT_IN_CLASS (function) != BUILT_IN_NORMAL)
3369     return NULL_TREE;
3370
3371   switch (DECL_FUNCTION_CODE (function))
3372     {
3373     case BUILT_IN_ABS:
3374     case BUILT_IN_LABS:
3375     case BUILT_IN_LLABS:
3376     case BUILT_IN_IMAXABS:
3377     case BUILT_IN_FABS:
3378     case BUILT_IN_FABSL:
3379     case BUILT_IN_FABSF:
3380       if (coerced_params == 0)
3381         return integer_zero_node;
3382       return build_unary_op (ABS_EXPR, TREE_VALUE (coerced_params), 0);
3383
3384     case BUILT_IN_CONJ:
3385     case BUILT_IN_CONJF:
3386     case BUILT_IN_CONJL:
3387       if (coerced_params == 0)
3388         return integer_zero_node;
3389       return build_unary_op (CONJ_EXPR, TREE_VALUE (coerced_params), 0);
3390
3391     case BUILT_IN_CREAL:
3392     case BUILT_IN_CREALF:
3393     case BUILT_IN_CREALL:
3394       if (coerced_params == 0)
3395         return integer_zero_node;
3396       return build_unary_op (REALPART_EXPR, TREE_VALUE (coerced_params), 0);
3397
3398     case BUILT_IN_CIMAG:
3399     case BUILT_IN_CIMAGF:
3400     case BUILT_IN_CIMAGL:
3401       if (coerced_params == 0)
3402         return integer_zero_node;
3403       return build_unary_op (IMAGPART_EXPR, TREE_VALUE (coerced_params), 0);
3404
3405     case BUILT_IN_ISGREATER:
3406       return expand_unordered_cmp (function, params, UNLE_EXPR, LE_EXPR);
3407
3408     case BUILT_IN_ISGREATEREQUAL:
3409       return expand_unordered_cmp (function, params, UNLT_EXPR, LT_EXPR);
3410
3411     case BUILT_IN_ISLESS:
3412       return expand_unordered_cmp (function, params, UNGE_EXPR, GE_EXPR);
3413
3414     case BUILT_IN_ISLESSEQUAL:
3415       return expand_unordered_cmp (function, params, UNGT_EXPR, GT_EXPR);
3416
3417     case BUILT_IN_ISLESSGREATER:
3418       return expand_unordered_cmp (function, params, UNEQ_EXPR, EQ_EXPR);
3419
3420     case BUILT_IN_ISUNORDERED:
3421       return expand_unordered_cmp (function, params, UNORDERED_EXPR, NOP_EXPR);
3422
3423     default:
3424       break;
3425     }
3426
3427   return NULL_TREE;
3428 }
3429
3430 /* Returns non-zero if CODE is the code for a statement.  */
3431
3432 int
3433 statement_code_p (code)
3434      enum tree_code code;
3435 {
3436   switch (code)
3437     {
3438     case CLEANUP_STMT:
3439     case EXPR_STMT:
3440     case COMPOUND_STMT:
3441     case DECL_STMT:
3442     case IF_STMT:
3443     case FOR_STMT:
3444     case WHILE_STMT:
3445     case DO_STMT:
3446     case RETURN_STMT:
3447     case BREAK_STMT:
3448     case CONTINUE_STMT:
3449     case SCOPE_STMT:
3450     case SWITCH_STMT:
3451     case GOTO_STMT:
3452     case LABEL_STMT:
3453     case ASM_STMT:
3454     case FILE_STMT:
3455     case CASE_LABEL:
3456       return 1;
3457
3458     default:
3459       if (lang_statement_code_p)
3460         return (*lang_statement_code_p) (code);
3461       return 0;
3462     }
3463 }
3464
3465 /* Walk the statement tree, rooted at *tp.  Apply FUNC to all the
3466    sub-trees of *TP in a pre-order traversal.  FUNC is called with the
3467    DATA and the address of each sub-tree.  If FUNC returns a non-NULL
3468    value, the traversal is aborted, and the value returned by FUNC is
3469    returned.  If FUNC sets WALK_SUBTREES to zero, then the subtrees of
3470    the node being visited are not walked.
3471
3472    We don't need a without_duplicates variant of this one because the
3473    statement tree is a tree, not a graph.  */
3474
3475 tree
3476 walk_stmt_tree (tp, func, data)
3477      tree *tp;
3478      walk_tree_fn func;
3479      void *data;
3480 {
3481   enum tree_code code;
3482   int walk_subtrees;
3483   tree result;
3484   int i, len;
3485
3486 #define WALK_SUBTREE(NODE)                              \
3487   do                                                    \
3488     {                                                   \
3489       result = walk_stmt_tree (&(NODE), func, data);    \
3490       if (result)                                       \
3491         return result;                                  \
3492     }                                                   \
3493   while (0)
3494
3495   /* Skip empty subtrees.  */
3496   if (!*tp)
3497     return NULL_TREE;
3498
3499   /* Skip subtrees below non-statement nodes.  */
3500   if (!statement_code_p (TREE_CODE (*tp)))
3501     return NULL_TREE;
3502
3503   /* Call the function.  */
3504   walk_subtrees = 1;
3505   result = (*func) (tp, &walk_subtrees, data);
3506
3507   /* If we found something, return it.  */
3508   if (result)
3509     return result;
3510
3511   /* FUNC may have modified the tree, recheck that we're looking at a
3512      statement node.  */
3513   code = TREE_CODE (*tp);
3514   if (!statement_code_p (code))
3515     return NULL_TREE;
3516
3517   /* Visit the subtrees unless FUNC decided that there was nothing
3518      interesting below this point in the tree.  */
3519   if (walk_subtrees)
3520     {
3521       /* Walk over all the sub-trees of this operand.  Statement nodes
3522          never contain RTL, and we needn't worry about TARGET_EXPRs.  */
3523       len = TREE_CODE_LENGTH (code);
3524
3525       /* Go through the subtrees.  We need to do this in forward order so
3526          that the scope of a FOR_EXPR is handled properly.  */
3527       for (i = 0; i < len; ++i)
3528         WALK_SUBTREE (TREE_OPERAND (*tp, i));
3529     }
3530
3531   /* Finally visit the chain.  This can be tail-recursion optimized if
3532      we write it this way.  */
3533   return walk_stmt_tree (&TREE_CHAIN (*tp), func, data);
3534
3535 #undef WALK_SUBTREE
3536 }
3537
3538 /* Used to compare case labels.  K1 and K2 are actually tree nodes
3539    representing case labels, or NULL_TREE for a `default' label.
3540    Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
3541    K2, and 0 if K1 and K2 are equal.  */
3542
3543 int
3544 case_compare (k1, k2)
3545      splay_tree_key k1;
3546      splay_tree_key k2;
3547 {
3548   /* Consider a NULL key (such as arises with a `default' label) to be
3549      smaller than anything else.  */
3550   if (!k1)
3551     return k2 ? -1 : 0;
3552   else if (!k2)
3553     return k1 ? 1 : 0;
3554
3555   return tree_int_cst_compare ((tree) k1, (tree) k2);
3556 }
3557
3558 /* Process a case label for the range LOW_VALUE ... HIGH_VALUE.  If
3559    LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is
3560    actually a `default' label.  If only HIGH_VALUE is NULL_TREE, then
3561    case label was declared using the usual C/C++ syntax, rather than
3562    the GNU case range extension.  CASES is a tree containing all the
3563    case ranges processed so far; COND is the condition for the
3564    switch-statement itself.  Returns the CASE_LABEL created, or
3565    ERROR_MARK_NODE if no CASE_LABEL is created.  */
3566
3567 tree
3568 c_add_case_label (cases, cond, low_value, high_value)
3569      splay_tree cases;
3570      tree cond;
3571      tree low_value;
3572      tree high_value;
3573 {
3574   tree type;
3575   tree label;
3576   tree case_label;
3577   splay_tree_node node;
3578
3579   /* Create the LABEL_DECL itself.  */
3580   label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
3581   DECL_CONTEXT (label) = current_function_decl;
3582
3583   /* If there was an error processing the switch condition, bail now
3584      before we get more confused.  */
3585   if (!cond || cond == error_mark_node)
3586     {
3587       /* Add a label anyhow so that the back-end doesn't think that
3588          the beginning of the switch is unreachable.  */
3589       if (!cases->root)
3590         add_stmt (build_case_label (NULL_TREE, NULL_TREE, label));
3591       return error_mark_node;
3592     }
3593
3594   if ((low_value && TREE_TYPE (low_value)
3595        && POINTER_TYPE_P (TREE_TYPE (low_value)))
3596       || (high_value && TREE_TYPE (high_value)
3597           && POINTER_TYPE_P (TREE_TYPE (high_value))))
3598     error ("pointers are not permitted as case values");
3599
3600   /* Case ranges are a GNU extension.  */
3601   if (high_value && pedantic)
3602     {
3603       if (c_language == clk_cplusplus)
3604         pedwarn ("ISO C++ forbids range expressions in switch statements");
3605       else
3606         pedwarn ("ISO C forbids range expressions in switch statements");
3607     }
3608
3609   type = TREE_TYPE (cond);
3610   if (low_value)
3611     {
3612       low_value = check_case_value (low_value);
3613       low_value = convert_and_check (type, low_value);
3614     }
3615   if (high_value)
3616     {
3617       high_value = check_case_value (high_value);
3618       high_value = convert_and_check (type, high_value);
3619     }
3620
3621   /* If an error has occurred, bail out now.  */
3622   if (low_value == error_mark_node || high_value == error_mark_node)
3623     {
3624       if (!cases->root)
3625         add_stmt (build_case_label (NULL_TREE, NULL_TREE, label));
3626       return error_mark_node;
3627     }
3628
3629   /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
3630      really a case range, even though it was written that way.  Remove
3631      the HIGH_VALUE to simplify later processing.  */
3632   if (tree_int_cst_equal (low_value, high_value))
3633     high_value = NULL_TREE;
3634   if (low_value && high_value
3635       && !tree_int_cst_lt (low_value, high_value))
3636     warning ("empty range specified");
3637
3638   /* Look up the LOW_VALUE in the table of case labels we already
3639      have.  */
3640   node = splay_tree_lookup (cases, (splay_tree_key) low_value);
3641   /* If there was not an exact match, check for overlapping ranges.
3642      There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
3643      that's a `default' label and the only overlap is an exact match.  */
3644   if (!node && (low_value || high_value))
3645     {
3646       splay_tree_node low_bound;
3647       splay_tree_node high_bound;
3648
3649       /* Even though there wasn't an exact match, there might be an
3650          overlap between this case range and another case range.
3651          Since we've (inductively) not allowed any overlapping case
3652          ranges, we simply need to find the greatest low case label
3653          that is smaller that LOW_VALUE, and the smallest low case
3654          label that is greater than LOW_VALUE.  If there is an overlap
3655          it will occur in one of these two ranges.  */
3656       low_bound = splay_tree_predecessor (cases,
3657                                           (splay_tree_key) low_value);
3658       high_bound = splay_tree_successor (cases,
3659                                          (splay_tree_key) low_value);
3660
3661       /* Check to see if the LOW_BOUND overlaps.  It is smaller than
3662          the LOW_VALUE, so there is no need to check unless the
3663          LOW_BOUND is in fact itself a case range.  */
3664       if (low_bound
3665           && CASE_HIGH ((tree) low_bound->value)
3666           && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
3667                                     low_value) >= 0)
3668         node = low_bound;
3669       /* Check to see if the HIGH_BOUND overlaps.  The low end of that
3670          range is bigger than the low end of the current range, so we
3671          are only interested if the current range is a real range, and
3672          not an ordinary case label.  */
3673       else if (high_bound
3674                && high_value
3675                && (tree_int_cst_compare ((tree) high_bound->key,
3676                                          high_value)
3677                    <= 0))
3678         node = high_bound;
3679     }
3680   /* If there was an overlap, issue an error.  */
3681   if (node)
3682     {
3683       tree duplicate = CASE_LABEL_DECL ((tree) node->value);
3684
3685       if (high_value)
3686         {
3687           error ("duplicate (or overlapping) case value");
3688           error_with_decl (duplicate,
3689                            "this is the first entry overlapping that value");
3690         }
3691       else if (low_value)
3692         {
3693           error ("duplicate case value") ;
3694           error_with_decl (duplicate, "previously used here");
3695         }
3696       else
3697         {
3698           error ("multiple default labels in one switch");
3699           error_with_decl (duplicate, "this is the first default label");
3700         }
3701       if (!cases->root)
3702         add_stmt (build_case_label (NULL_TREE, NULL_TREE, label));
3703     }
3704
3705   /* Add a CASE_LABEL to the statement-tree.  */
3706   case_label = add_stmt (build_case_label (low_value, high_value, label));
3707   /* Register this case label in the splay tree.  */
3708   splay_tree_insert (cases,
3709                      (splay_tree_key) low_value,
3710                      (splay_tree_value) case_label);
3711
3712   return case_label;
3713 }
3714
3715 /* Finish an expression taking the address of LABEL.  Returns an
3716    expression for the address.  */
3717
3718 tree
3719 finish_label_address_expr (label)
3720      tree label;
3721 {
3722   tree result;
3723
3724   if (pedantic)
3725     {
3726       if (c_language == clk_cplusplus)
3727         pedwarn ("ISO C++ forbids taking the address of a label");
3728       else
3729         pedwarn ("ISO C forbids taking the address of a label");
3730     }
3731
3732   label = lookup_label (label);
3733   if (label == NULL_TREE)
3734     result = null_pointer_node;
3735   else
3736     {
3737       TREE_USED (label) = 1;
3738       result = build1 (ADDR_EXPR, ptr_type_node, label);
3739       TREE_CONSTANT (result) = 1;
3740       /* The current function in not necessarily uninlinable.
3741          Computed gotos are incompatible with inlining, but the value
3742          here could be used only in a diagnostic, for example.  */
3743     }
3744
3745   return result;
3746 }
3747
3748 /* Hook used by expand_expr to expand language-specific tree codes.  */
3749
3750 rtx
3751 c_expand_expr (exp, target, tmode, modifier)
3752      tree exp;
3753      rtx target;
3754      enum machine_mode tmode;
3755      int modifier;  /* Actually enum_modifier.  */
3756 {
3757   switch (TREE_CODE (exp))
3758     {
3759     case STMT_EXPR:
3760       {
3761         tree rtl_expr;
3762         rtx result;
3763         bool preserve_result = false;
3764
3765         /* Since expand_expr_stmt calls free_temp_slots after every
3766            expression statement, we must call push_temp_slots here.
3767            Otherwise, any temporaries in use now would be considered
3768            out-of-scope after the first EXPR_STMT from within the
3769            STMT_EXPR.  */
3770         push_temp_slots ();
3771         rtl_expr = expand_start_stmt_expr (!STMT_EXPR_NO_SCOPE (exp));
3772
3773         /* If we want the result of this expression, find the last
3774            EXPR_STMT in the COMPOUND_STMT and mark it as addressable.  */
3775         if (target != const0_rtx
3776             && TREE_CODE (STMT_EXPR_STMT (exp)) == COMPOUND_STMT
3777             && TREE_CODE (COMPOUND_BODY (STMT_EXPR_STMT (exp))) == SCOPE_STMT)
3778           {
3779             tree expr = COMPOUND_BODY (STMT_EXPR_STMT (exp));
3780             tree last = TREE_CHAIN (expr);
3781
3782             while (TREE_CHAIN (last))
3783               {
3784                 expr = last;
3785                 last = TREE_CHAIN (last);
3786               }
3787
3788             if (TREE_CODE (last) == SCOPE_STMT
3789                 && TREE_CODE (expr) == EXPR_STMT)
3790               {
3791                 TREE_ADDRESSABLE (expr) = 1;
3792                 preserve_result = true;
3793               }
3794           }
3795
3796         expand_stmt (STMT_EXPR_STMT (exp));
3797         expand_end_stmt_expr (rtl_expr);
3798
3799         result = expand_expr (rtl_expr, target, tmode, modifier);
3800         if (preserve_result && GET_CODE (result) == MEM)
3801           {
3802             if (GET_MODE (result) != BLKmode)
3803               result = copy_to_reg (result);
3804             else
3805               preserve_temp_slots (result);
3806           }
3807
3808         /* If the statment-expression does not have a scope, then the
3809            new temporaries we created within it must live beyond the
3810            statement-expression.  */
3811         if (STMT_EXPR_NO_SCOPE (exp))
3812           preserve_temp_slots (NULL_RTX);
3813
3814         pop_temp_slots ();
3815         return result;
3816       }
3817       break;
3818
3819     case CALL_EXPR:
3820       {
3821         if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
3822             && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
3823                 == FUNCTION_DECL)
3824             && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
3825             && (DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
3826                 == BUILT_IN_FRONTEND))
3827           return c_expand_builtin (exp, target, tmode, modifier);
3828         else
3829           abort ();
3830       }
3831       break;
3832
3833     case COMPOUND_LITERAL_EXPR:
3834       {
3835         /* Initialize the anonymous variable declared in the compound
3836            literal, then return the variable.  */
3837         tree decl = COMPOUND_LITERAL_EXPR_DECL (exp);
3838         emit_local_var (decl);
3839         return expand_expr (decl, target, tmode, modifier);
3840       }
3841
3842     default:
3843       abort ();
3844     }
3845
3846   abort ();
3847   return NULL;
3848 }
3849
3850 /* Hook used by safe_from_p to handle language-specific tree codes.  */
3851
3852 int
3853 c_safe_from_p (target, exp)
3854      rtx target;
3855      tree exp;
3856 {
3857   /* We can see statements here when processing the body of a
3858      statement-expression.  For a declaration statement declaring a
3859      variable, look at the variable's initializer.  */
3860   if (TREE_CODE (exp) == DECL_STMT)
3861     {
3862       tree decl = DECL_STMT_DECL (exp);
3863
3864       if (TREE_CODE (decl) == VAR_DECL
3865           && DECL_INITIAL (decl)
3866           && !safe_from_p (target, DECL_INITIAL (decl), /*top_p=*/0))
3867         return 0;
3868     }
3869
3870   /* For any statement, we must follow the statement-chain.  */
3871   if (statement_code_p (TREE_CODE (exp)) && TREE_CHAIN (exp))
3872     return safe_from_p (target, TREE_CHAIN (exp), /*top_p=*/0);
3873
3874   /* Assume everything else is safe.  */
3875   return 1;
3876 }
3877
3878 /* Hook used by unsafe_for_reeval to handle language-specific tree codes.  */
3879
3880 int
3881 c_common_unsafe_for_reeval (exp)
3882      tree exp;
3883 {
3884   /* Statement expressions may not be reevaluated, likewise compound
3885      literals.  */
3886   if (TREE_CODE (exp) == STMT_EXPR
3887       || TREE_CODE (exp) == COMPOUND_LITERAL_EXPR)
3888     return 2;
3889
3890   /* Walk all other expressions.  */
3891   return -1;
3892 }
3893
3894 /* Hook used by staticp to handle language-specific tree codes.  */
3895
3896 int
3897 c_staticp (exp)
3898      tree exp;
3899 {
3900   if (TREE_CODE (exp) == COMPOUND_LITERAL_EXPR
3901       && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp)))
3902     return 1;
3903   return 0;
3904 }
3905
3906 #define CALLED_AS_BUILT_IN(NODE) \
3907    (!strncmp (IDENTIFIER_POINTER (DECL_NAME (NODE)), "__builtin_", 10))
3908
3909 static rtx
3910 c_expand_builtin (exp, target, tmode, modifier)
3911      tree exp;
3912      rtx target;
3913      enum machine_mode tmode;
3914      enum expand_modifier modifier;
3915 {
3916   tree type = TREE_TYPE (exp);
3917   tree fndecl = TREE_OPERAND (TREE_OPERAND (exp, 0), 0);
3918   tree arglist = TREE_OPERAND (exp, 1);
3919   enum built_in_function fcode = DECL_FUNCTION_CODE (fndecl);
3920   enum tree_code code = TREE_CODE (exp);
3921   const int ignore = (target == const0_rtx
3922                       || ((code == NON_LVALUE_EXPR || code == NOP_EXPR
3923                            || code == CONVERT_EXPR || code == REFERENCE_EXPR
3924                            || code == COND_EXPR)
3925                           && TREE_CODE (type) == VOID_TYPE));
3926
3927   if (! optimize && ! CALLED_AS_BUILT_IN (fndecl))
3928     return expand_call (exp, target, ignore);
3929
3930   switch (fcode)
3931     {
3932     case BUILT_IN_PRINTF:
3933       target = c_expand_builtin_printf (arglist, target, tmode,
3934                                         modifier, ignore, /*unlocked=*/ 0);
3935       if (target)
3936         return target;
3937       break;
3938
3939     case BUILT_IN_PRINTF_UNLOCKED:
3940       target = c_expand_builtin_printf (arglist, target, tmode,
3941                                         modifier, ignore, /*unlocked=*/ 1);
3942       if (target)
3943         return target;
3944       break;
3945
3946     case BUILT_IN_FPRINTF:
3947       target = c_expand_builtin_fprintf (arglist, target, tmode,
3948                                          modifier, ignore, /*unlocked=*/ 0);
3949       if (target)
3950         return target;
3951       break;
3952
3953     case BUILT_IN_FPRINTF_UNLOCKED:
3954       target = c_expand_builtin_fprintf (arglist, target, tmode,
3955                                          modifier, ignore, /*unlocked=*/ 1);
3956       if (target)
3957         return target;
3958       break;
3959
3960     default:                    /* just do library call, if unknown builtin */
3961       error ("built-in function `%s' not currently supported",
3962              IDENTIFIER_POINTER (DECL_NAME (fndecl)));
3963     }
3964
3965   /* The switch statement above can drop through to cause the function
3966      to be called normally.  */
3967   return expand_call (exp, target, ignore);
3968 }
3969
3970 /* Check an arglist to *printf for problems.  The arglist should start
3971    at the format specifier, with the remaining arguments immediately
3972    following it.  */
3973 static int
3974 is_valid_printf_arglist (arglist)
3975      tree arglist;
3976 {
3977   /* Save this value so we can restore it later.  */
3978   const int SAVE_pedantic = pedantic;
3979   int diagnostic_occurred = 0;
3980   tree attrs;
3981
3982   /* Set this to a known value so the user setting won't affect code
3983      generation.  */
3984   pedantic = 1;
3985   /* Check to make sure there are no format specifier errors.  */
3986   attrs = tree_cons (get_identifier ("format"),
3987                      tree_cons (NULL_TREE,
3988                                 get_identifier ("printf"),
3989                                 tree_cons (NULL_TREE,
3990                                            integer_one_node,
3991                                            tree_cons (NULL_TREE,
3992                                                       build_int_2 (2, 0),
3993                                                       NULL_TREE))),
3994                      NULL_TREE);
3995   check_function_format (&diagnostic_occurred, attrs, arglist);
3996
3997   /* Restore the value of `pedantic'.  */
3998   pedantic = SAVE_pedantic;
3999
4000   /* If calling `check_function_format_ptr' produces a warning, we
4001      return false, otherwise we return true.  */
4002   return ! diagnostic_occurred;
4003 }
4004
4005 /* If the arguments passed to printf are suitable for optimizations,
4006    we attempt to transform the call.  */
4007 static rtx
4008 c_expand_builtin_printf (arglist, target, tmode, modifier, ignore, unlocked)
4009      tree arglist;
4010      rtx target;
4011      enum machine_mode tmode;
4012      enum expand_modifier modifier;
4013      int ignore;
4014      int unlocked;
4015 {
4016   tree fn_putchar = unlocked ?
4017     built_in_decls[BUILT_IN_PUTCHAR_UNLOCKED] : built_in_decls[BUILT_IN_PUTCHAR];
4018   tree fn_puts = unlocked ?
4019     built_in_decls[BUILT_IN_PUTS_UNLOCKED] : built_in_decls[BUILT_IN_PUTS];
4020   tree fn, format_arg, stripped_string;
4021
4022   /* If the return value is used, or the replacement _DECL isn't
4023      initialized, don't do the transformation.  */
4024   if (!ignore || !fn_putchar || !fn_puts)
4025     return 0;
4026
4027   /* Verify the required arguments in the original call.  */
4028   if (arglist == 0
4029       || (TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) != POINTER_TYPE))
4030     return 0;
4031
4032   /* Check the specifier vs. the parameters.  */
4033   if (!is_valid_printf_arglist (arglist))
4034     return 0;
4035
4036   format_arg = TREE_VALUE (arglist);
4037   stripped_string = format_arg;
4038   STRIP_NOPS (stripped_string);
4039   if (stripped_string && TREE_CODE (stripped_string) == ADDR_EXPR)
4040     stripped_string = TREE_OPERAND (stripped_string, 0);
4041
4042   /* If the format specifier isn't a STRING_CST, punt.  */
4043   if (TREE_CODE (stripped_string) != STRING_CST)
4044     return 0;
4045
4046   /* OK!  We can attempt optimization.  */
4047
4048   /* If the format specifier was "%s\n", call __builtin_puts(arg2).  */
4049   if (strcmp (TREE_STRING_POINTER (stripped_string), "%s\n") == 0)
4050     {
4051       arglist = TREE_CHAIN (arglist);
4052       fn = fn_puts;
4053     }
4054   /* If the format specifier was "%c", call __builtin_putchar (arg2).  */
4055   else if (strcmp (TREE_STRING_POINTER (stripped_string), "%c") == 0)
4056     {
4057       arglist = TREE_CHAIN (arglist);
4058       fn = fn_putchar;
4059     }
4060   else
4061     {
4062       /* We can't handle anything else with % args or %% ... yet.  */
4063       if (strchr (TREE_STRING_POINTER (stripped_string), '%'))
4064         return 0;
4065
4066       /* If the resulting constant string has a length of 1, call
4067          putchar.  Note, TREE_STRING_LENGTH includes the terminating
4068          NULL in its count.  */
4069       if (TREE_STRING_LENGTH (stripped_string) == 2)
4070         {
4071           /* Given printf("c"), (where c is any one character,)
4072              convert "c"[0] to an int and pass that to the replacement
4073              function.  */
4074           arglist = build_int_2 (TREE_STRING_POINTER (stripped_string)[0], 0);
4075           arglist = build_tree_list (NULL_TREE, arglist);
4076
4077           fn = fn_putchar;
4078         }
4079       /* If the resulting constant was "string\n", call
4080          __builtin_puts("string").  Ensure "string" has at least one
4081          character besides the trailing \n.  Note, TREE_STRING_LENGTH
4082          includes the terminating NULL in its count.  */
4083       else if (TREE_STRING_LENGTH (stripped_string) > 2
4084                && TREE_STRING_POINTER (stripped_string)
4085                [TREE_STRING_LENGTH (stripped_string) - 2] == '\n')
4086         {
4087           /* Create a NULL-terminated string that's one char shorter
4088              than the original, stripping off the trailing '\n'.  */
4089           const int newlen = TREE_STRING_LENGTH (stripped_string) - 1;
4090           char *newstr = (char *) alloca (newlen);
4091           memcpy (newstr, TREE_STRING_POINTER (stripped_string), newlen - 1);
4092           newstr[newlen - 1] = 0;
4093
4094           arglist = fix_string_type (build_string (newlen, newstr));
4095           arglist = build_tree_list (NULL_TREE, arglist);
4096           fn = fn_puts;
4097         }
4098       else
4099         /* We'd like to arrange to call fputs(string) here, but we
4100            need stdout and don't have a way to get it ... yet.  */
4101         return 0;
4102     }
4103
4104   return expand_expr (build_function_call (fn, arglist),
4105                       (ignore ? const0_rtx : target),
4106                       tmode, modifier);
4107 }
4108
4109 /* If the arguments passed to fprintf are suitable for optimizations,
4110    we attempt to transform the call.  */
4111 static rtx
4112 c_expand_builtin_fprintf (arglist, target, tmode, modifier, ignore, unlocked)
4113      tree arglist;
4114      rtx target;
4115      enum machine_mode tmode;
4116      enum expand_modifier modifier;
4117      int ignore;
4118      int unlocked;
4119 {
4120   tree fn_fputc = unlocked ?
4121     built_in_decls[BUILT_IN_FPUTC_UNLOCKED] : built_in_decls[BUILT_IN_FPUTC];
4122   tree fn_fputs = unlocked ?
4123     built_in_decls[BUILT_IN_FPUTS_UNLOCKED] : built_in_decls[BUILT_IN_FPUTS];
4124   tree fn, format_arg, stripped_string;
4125
4126   /* If the return value is used, or the replacement _DECL isn't
4127      initialized, don't do the transformation.  */
4128   if (!ignore || !fn_fputc || !fn_fputs)
4129     return 0;
4130
4131   /* Verify the required arguments in the original call.  */
4132   if (arglist == 0
4133       || (TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) != POINTER_TYPE)
4134       || (TREE_CHAIN (arglist) == 0)
4135       || (TREE_CODE (TREE_TYPE (TREE_VALUE (TREE_CHAIN (arglist)))) !=
4136           POINTER_TYPE))
4137     return 0;
4138
4139   /* Check the specifier vs. the parameters.  */
4140   if (!is_valid_printf_arglist (TREE_CHAIN (arglist)))
4141     return 0;
4142
4143   format_arg = TREE_VALUE (TREE_CHAIN (arglist));
4144   stripped_string = format_arg;
4145   STRIP_NOPS (stripped_string);
4146   if (stripped_string && TREE_CODE (stripped_string) == ADDR_EXPR)
4147     stripped_string = TREE_OPERAND (stripped_string, 0);
4148
4149   /* If the format specifier isn't a STRING_CST, punt.  */
4150   if (TREE_CODE (stripped_string) != STRING_CST)
4151     return 0;
4152
4153   /* OK!  We can attempt optimization.  */
4154
4155   /* If the format specifier was "%s", call __builtin_fputs(arg3, arg1).  */
4156   if (strcmp (TREE_STRING_POINTER (stripped_string), "%s") == 0)
4157     {
4158       tree newarglist = build_tree_list (NULL_TREE, TREE_VALUE (arglist));
4159       arglist = tree_cons (NULL_TREE,
4160                            TREE_VALUE (TREE_CHAIN (TREE_CHAIN (arglist))),
4161                            newarglist);
4162       fn = fn_fputs;
4163     }
4164   /* If the format specifier was "%c", call __builtin_fputc (arg3, arg1).  */
4165   else if (strcmp (TREE_STRING_POINTER (stripped_string), "%c") == 0)
4166     {
4167       tree newarglist = build_tree_list (NULL_TREE, TREE_VALUE (arglist));
4168       arglist = tree_cons (NULL_TREE,
4169                            TREE_VALUE (TREE_CHAIN (TREE_CHAIN (arglist))),
4170                            newarglist);
4171       fn = fn_fputc;
4172     }
4173   else
4174     {
4175       /* We can't handle anything else with % args or %% ... yet.  */
4176       if (strchr (TREE_STRING_POINTER (stripped_string), '%'))
4177         return 0;
4178
4179       /* When "string" doesn't contain %, replace all cases of
4180          fprintf(stream,string) with fputs(string,stream).  The fputs
4181          builtin will take take of special cases like length==1.  */
4182       arglist = tree_cons (NULL_TREE, TREE_VALUE (TREE_CHAIN (arglist)),
4183                            build_tree_list (NULL_TREE, TREE_VALUE (arglist)));
4184       fn = fn_fputs;
4185     }
4186
4187   return expand_expr (build_function_call (fn, arglist),
4188                       (ignore ? const0_rtx : target),
4189                       tmode, modifier);
4190 }
4191 \f
4192
4193 /* Given a boolean expression ARG, return a tree representing an increment
4194    or decrement (as indicated by CODE) of ARG.  The front end must check for
4195    invalid cases (e.g., decrement in C++).  */
4196 tree
4197 boolean_increment (code, arg)
4198      enum tree_code code;
4199      tree arg;
4200 {
4201   tree val;
4202   tree true_res = (c_language == clk_cplusplus
4203                    ? boolean_true_node
4204                    : c_bool_true_node);
4205   arg = stabilize_reference (arg);
4206   switch (code)
4207     {
4208     case PREINCREMENT_EXPR:
4209       val = build (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
4210       break;
4211     case POSTINCREMENT_EXPR:
4212       val = build (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
4213       arg = save_expr (arg);
4214       val = build (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
4215       val = build (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
4216       break;
4217     case PREDECREMENT_EXPR:
4218       val = build (MODIFY_EXPR, TREE_TYPE (arg), arg, invert_truthvalue (arg));
4219       break;
4220     case POSTDECREMENT_EXPR:
4221       val = build (MODIFY_EXPR, TREE_TYPE (arg), arg, invert_truthvalue (arg));
4222       arg = save_expr (arg);
4223       val = build (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
4224       val = build (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
4225       break;
4226     default:
4227       abort ();
4228     }
4229   TREE_SIDE_EFFECTS (val) = 1;
4230   return val;
4231 }
4232 \f
4233 /* Handle C and C++ default attributes.  */
4234
4235 enum built_in_attribute
4236 {
4237 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
4238 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
4239 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
4240 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
4241 #define DEF_FN_ATTR(NAME, ATTRS, PREDICATE) /* No entry needed in enum.  */
4242 #include "builtin-attrs.def"
4243 #undef DEF_ATTR_NULL_TREE
4244 #undef DEF_ATTR_INT
4245 #undef DEF_ATTR_IDENT
4246 #undef DEF_ATTR_TREE_LIST
4247 #undef DEF_FN_ATTR
4248   ATTR_LAST
4249 };
4250
4251 static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
4252
4253 static bool c_attrs_initialized = false;
4254
4255 static void c_init_attributes PARAMS ((void));
4256
4257 /* Common initialization before parsing options.  */
4258 void
4259 c_common_init_options (lang)
4260      enum c_language_kind lang;
4261 {
4262   c_language = lang;
4263   parse_in = cpp_create_reader (lang == clk_c || lang == clk_objective_c
4264                                 ? CLK_GNUC89 : CLK_GNUCXX);
4265   if (lang == clk_objective_c)
4266     cpp_get_options (parse_in)->objc = 1;
4267
4268   /* Mark as "unspecified" (see c_common_post_options).  */
4269   flag_bounds_check = -1;
4270 }
4271
4272 /* Post-switch processing.  */
4273 void
4274 c_common_post_options ()
4275 {
4276   cpp_post_options (parse_in);
4277
4278   flag_inline_trees = 1;
4279
4280   /* Use tree inlining if possible.  Function instrumentation is only
4281      done in the RTL level, so we disable tree inlining.  */
4282   if (! flag_instrument_function_entry_exit)
4283     {
4284       if (!flag_no_inline)
4285         flag_no_inline = 1;
4286       if (flag_inline_functions)
4287         {
4288           flag_inline_trees = 2;
4289           flag_inline_functions = 0;
4290         }
4291     }
4292
4293   /* If still "unspecified", make it match -fbounded-pointers.  */
4294   if (flag_bounds_check == -1)
4295     flag_bounds_check = flag_bounded_pointers;
4296
4297   /* Special format checking options don't work without -Wformat; warn if
4298      they are used.  */
4299   if (warn_format_y2k && !warn_format)
4300     warning ("-Wformat-y2k ignored without -Wformat");
4301   if (warn_format_extra_args && !warn_format)
4302     warning ("-Wformat-extra-args ignored without -Wformat");
4303   if (warn_format_zero_length && !warn_format)
4304     warning ("-Wformat-zero-length ignored without -Wformat");
4305   if (warn_format_nonliteral && !warn_format)
4306     warning ("-Wformat-nonliteral ignored without -Wformat");
4307   if (warn_format_security && !warn_format)
4308     warning ("-Wformat-security ignored without -Wformat");
4309   if (warn_missing_format_attribute && !warn_format)
4310     warning ("-Wmissing-format-attribute ignored without -Wformat");
4311
4312   /* If an error has occurred in cpplib, note it so we fail
4313      immediately.  */
4314   errorcount += cpp_errors (parse_in);
4315 }
4316
4317 /* Hook that registers front end and target-specific built-ins.  */
4318 static void
4319 cb_register_builtins (pfile)
4320      cpp_reader *pfile;
4321 {
4322   /* -undef turns off target-specific built-ins.  */
4323   if (flag_undef)
4324     return;
4325
4326   if (c_language == clk_cplusplus)
4327     {
4328       if (SUPPORTS_ONE_ONLY)
4329         cpp_define (pfile, "__GXX_WEAK__=1");
4330       else
4331         cpp_define (pfile, "__GXX_WEAK__=0");
4332     }
4333
4334   /* libgcc needs to know this.  */
4335   if (USING_SJLJ_EXCEPTIONS)
4336     cpp_define (pfile, "__USING_SJLJ_EXCEPTIONS__");
4337
4338   /* stddef.h needs to know these.  */
4339   builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0);
4340   builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0);
4341   builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0);
4342   builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0);
4343
4344   /* limits.h needs to know these.  */
4345   builtin_define_type_max ("__SCHAR_MAX__", signed_char_type_node, 0);
4346   builtin_define_type_max ("__SHRT_MAX__", short_integer_type_node, 0);
4347   builtin_define_type_max ("__INT_MAX__", integer_type_node, 0);
4348   builtin_define_type_max ("__LONG_MAX__", long_integer_type_node, 1);
4349   builtin_define_type_max ("__LONG_LONG_MAX__", long_long_integer_type_node, 2);
4350
4351   {
4352     char buf[8];
4353     sprintf (buf, "%d", (int) TYPE_PRECISION (signed_char_type_node));
4354     builtin_define_with_value ("__CHAR_BIT__", buf, 0);
4355   }
4356
4357   /* For use in assembly language.  */
4358   builtin_define_with_value ("__REGISTER_PREFIX__", REGISTER_PREFIX, 0);
4359   builtin_define_with_value ("__USER_LABEL_PREFIX__", user_label_prefix, 0);
4360
4361   /* Misc.  */
4362   builtin_define_with_value ("__VERSION__", version_string, 1);
4363
4364   /* Other target-independent built-ins determined by command-line
4365      options.  */
4366   if (optimize_size)
4367     cpp_define (pfile, "__OPTIMIZE_SIZE__");
4368   if (optimize)
4369     cpp_define (pfile, "__OPTIMIZE__");
4370
4371   if (flag_hosted)
4372     cpp_define (pfile, "__STDC_HOSTED__=1");
4373   else
4374     cpp_define (pfile, "__STDC_HOSTED__=0");
4375
4376   if (fast_math_flags_set_p ())
4377     cpp_define (pfile, "__FAST_MATH__");
4378   if (flag_no_inline)
4379     cpp_define (pfile, "__NO_INLINE__");
4380
4381   if (flag_iso)
4382     cpp_define (pfile, "__STRICT_ANSI__");
4383
4384   if (!flag_signed_char)
4385     cpp_define (pfile, "__CHAR_UNSIGNED__");
4386
4387   /* A straightforward target hook doesn't work, because of problems
4388      linking that hook's body when part of non-C front ends.  */
4389 # define preprocessing_asm_p() (cpp_get_options (pfile)->lang == CLK_ASM)
4390 # define builtin_define(TXT) cpp_define (pfile, TXT)
4391 # define builtin_assert(TXT) cpp_assert (pfile, TXT)
4392   TARGET_CPU_CPP_BUILTINS ();
4393   TARGET_OS_CPP_BUILTINS ();
4394 }
4395
4396 /* Pass an object-like macro.  If it doesn't lie in the user's
4397    namespace, defines it unconditionally.  Otherwise define a version
4398    with two leading underscores, and another version with two leading
4399    and trailing underscores, and define the original only if an ISO
4400    standard was not nominated.
4401
4402    e.g. passing "unix" defines "__unix", "__unix__" and possibly
4403    "unix".  Passing "_mips" defines "__mips", "__mips__" and possibly
4404    "_mips".  */
4405 void
4406 builtin_define_std (macro)
4407      const char *macro;
4408 {
4409   size_t len = strlen (macro);
4410   char *buff = alloca (len + 5);
4411   char *p = buff + 2;
4412   char *q = p + len;
4413
4414   /* prepend __ (or maybe just _) if in user's namespace.  */
4415   memcpy (p, macro, len + 1);
4416   if (!( *p == '_' && (p[1] == '_' || ISUPPER (p[1]))))
4417     {
4418       if (*p != '_')
4419         *--p = '_';
4420       if (p[1] != '_')
4421         *--p = '_';
4422     }
4423   cpp_define (parse_in, p);
4424
4425   /* If it was in user's namespace...  */
4426   if (p != buff + 2)
4427     {
4428       /* Define the macro with leading and following __.  */
4429       if (q[-1] != '_')
4430         *q++ = '_';
4431       if (q[-2] != '_')
4432         *q++ = '_';
4433       *q = '\0';
4434       cpp_define (parse_in, p);
4435
4436       /* Finally, define the original macro if permitted.  */
4437       if (!flag_iso)
4438         cpp_define (parse_in, macro);
4439     }
4440 }
4441
4442 /* Pass an object-like macro and a value to define it to.  The third
4443    parameter says whether or not to turn the value into a string
4444    constant.  */
4445 static void
4446 builtin_define_with_value (macro, expansion, is_str)
4447      const char *macro;
4448      const char *expansion;
4449      int is_str;
4450 {
4451   char *buf;
4452   size_t mlen = strlen (macro);
4453   size_t elen = strlen (expansion);
4454   size_t extra = 2;  /* space for an = and a NUL */
4455
4456   if (is_str)
4457     extra += 2;  /* space for two quote marks */
4458
4459   buf = alloca (mlen + elen + extra);
4460   if (is_str)
4461     sprintf (buf, "%s=\"%s\"", macro, expansion);
4462   else
4463     sprintf (buf, "%s=%s", macro, expansion);
4464
4465   cpp_define (parse_in, buf);
4466 }
4467
4468 /* Define MAX for TYPE based on the precision of the type, which is assumed
4469    to be signed.  IS_LONG is 1 for type "long" and 2 for "long long".  */
4470
4471 static void
4472 builtin_define_type_max (macro, type, is_long)
4473      const char *macro;
4474      tree type;
4475      int is_long;
4476 {
4477   const char *value;
4478   char *buf;
4479   size_t mlen, vlen, extra;
4480
4481   /* Pre-rendering the values mean we don't have to futz with printing a
4482      multi-word decimal value.  There are also a very limited number of
4483      precisions that we support, so it's really a waste of time.  */
4484   switch (TYPE_PRECISION (type))
4485     {
4486     case 8:
4487       value = "127";
4488       break;
4489     case 16:
4490       value = "32767";
4491       break;
4492     case 32:
4493       value = "2147483647";
4494       break;
4495     case 64:
4496       value = "9223372036854775807";
4497       break;
4498     case 128:
4499       value = "170141183460469231731687303715884105727";
4500       break;
4501     default:
4502       abort ();
4503     }
4504
4505   mlen = strlen (macro);
4506   vlen = strlen (value);
4507   extra = 2 + is_long;
4508   buf = alloca (mlen + vlen + extra);
4509
4510   sprintf (buf, "%s=%s%s", macro, value,
4511            (is_long == 1 ? "L" : is_long == 2 ? "LL" : ""));
4512
4513   cpp_define (parse_in, buf);
4514 }
4515
4516 /* Front end initialization common to C, ObjC and C++.  */
4517 const char *
4518 c_common_init (filename)
4519      const char *filename;
4520 {
4521   cpp_options *options = cpp_get_options (parse_in);
4522
4523   /* Set up preprocessor arithmetic.  Must be done after call to
4524      c_common_nodes_and_builtins for wchar_type_node to be good.  */
4525   options->precision = TYPE_PRECISION (intmax_type_node);
4526   options->char_precision = TYPE_PRECISION (char_type_node);
4527   options->int_precision = TYPE_PRECISION (integer_type_node);
4528   options->wchar_precision = TYPE_PRECISION (wchar_type_node);
4529   options->unsigned_wchar = TREE_UNSIGNED (wchar_type_node);
4530   options->unsigned_char = !flag_signed_char;
4531   options->warn_multichar = warn_multichar;
4532   options->stdc_0_in_system_headers = STDC_0_IN_SYSTEM_HEADERS;
4533
4534   /* We want -Wno-long-long to override -pedantic -std=non-c99
4535      whatever the ordering.  */
4536   options->warn_long_long = warn_long_long && !flag_isoc99 && pedantic;
4537
4538   /* Register preprocessor built-ins before calls to
4539      cpp_main_file.  */
4540   cpp_get_callbacks (parse_in)->register_builtins = cb_register_builtins;
4541
4542   /* NULL is passed up to toplev.c and we exit quickly.  */
4543   if (flag_preprocess_only)
4544     {
4545       cpp_preprocess_file (parse_in);
4546       return NULL;
4547     }
4548
4549   /* Do this before initializing pragmas, as then cpplib's hash table
4550      has been set up.  */
4551   filename = init_c_lex (filename);
4552
4553   init_pragma ();
4554
4555   if (!c_attrs_initialized)
4556     c_init_attributes ();
4557
4558   return filename;
4559 }
4560
4561 /* Common finish hook for the C, ObjC and C++ front ends.  */
4562 void
4563 c_common_finish ()
4564 {
4565   cpp_finish (parse_in);
4566
4567   /* For performance, avoid tearing down cpplib's internal structures.
4568      Call cpp_errors () instead of cpp_destroy ().  */
4569   errorcount += cpp_errors (parse_in);
4570 }
4571
4572 static void
4573 c_init_attributes ()
4574 {
4575   /* Fill in the built_in_attributes array.  */
4576 #define DEF_ATTR_NULL_TREE(ENUM)                \
4577   built_in_attributes[(int) ENUM] = NULL_TREE;
4578 #define DEF_ATTR_INT(ENUM, VALUE)                                            \
4579   built_in_attributes[(int) ENUM] = build_int_2 (VALUE, VALUE < 0 ? -1 : 0);
4580 #define DEF_ATTR_IDENT(ENUM, STRING)                            \
4581   built_in_attributes[(int) ENUM] = get_identifier (STRING);
4582 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
4583   built_in_attributes[(int) ENUM]                       \
4584     = tree_cons (built_in_attributes[(int) PURPOSE],    \
4585                  built_in_attributes[(int) VALUE],      \
4586                  built_in_attributes[(int) CHAIN]);
4587 #define DEF_FN_ATTR(NAME, ATTRS, PREDICATE) /* No initialization needed.  */
4588 #include "builtin-attrs.def"
4589 #undef DEF_ATTR_NULL_TREE
4590 #undef DEF_ATTR_INT
4591 #undef DEF_ATTR_IDENT
4592 #undef DEF_ATTR_TREE_LIST
4593 #undef DEF_FN_ATTR
4594   c_attrs_initialized = true;
4595 }
4596
4597 /* Depending on the name of DECL, apply default attributes to it.  */
4598
4599 void
4600 c_common_insert_default_attributes (decl)
4601      tree decl;
4602 {
4603   tree name = DECL_NAME (decl);
4604
4605   if (!c_attrs_initialized)
4606     c_init_attributes ();
4607
4608 #define DEF_ATTR_NULL_TREE(ENUM) /* Nothing needed after initialization.  */
4609 #define DEF_ATTR_INT(ENUM, VALUE)
4610 #define DEF_ATTR_IDENT(ENUM, STRING)
4611 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN)
4612 #define DEF_FN_ATTR(NAME, ATTRS, PREDICATE)                     \
4613   if ((PREDICATE) && name == built_in_attributes[(int) NAME])   \
4614     decl_attributes (&decl, built_in_attributes[(int) ATTRS],   \
4615                      ATTR_FLAG_BUILT_IN);
4616 #include "builtin-attrs.def"
4617 #undef DEF_ATTR_NULL_TREE
4618 #undef DEF_ATTR_INT
4619 #undef DEF_ATTR_IDENT
4620 #undef DEF_ATTR_TREE_LIST
4621 #undef DEF_FN_ATTR
4622 }
4623
4624 /* Output a -Wshadow warning MSGID about NAME, an IDENTIFIER_NODE, and
4625    additionally give the location of the previous declaration DECL.  */
4626 void
4627 shadow_warning (msgid, name, decl)
4628      const char *msgid;
4629      tree name, decl;
4630 {
4631   warning ("declaration of `%s' shadows %s", IDENTIFIER_POINTER (name), msgid);
4632   warning_with_file_and_line (DECL_SOURCE_FILE (decl),
4633                               DECL_SOURCE_LINE (decl),
4634                               "shadowed declaration is here");
4635 }
4636
4637 /* Attribute handlers common to C front ends.  */
4638
4639 /* Handle a "packed" attribute; arguments as in
4640    struct attribute_spec.handler.  */
4641
4642 static tree
4643 handle_packed_attribute (node, name, args, flags, no_add_attrs)
4644      tree *node;
4645      tree name;
4646      tree args ATTRIBUTE_UNUSED;
4647      int flags;
4648      bool *no_add_attrs;
4649 {
4650   tree *type = NULL;
4651   if (DECL_P (*node))
4652     {
4653       if (TREE_CODE (*node) == TYPE_DECL)
4654         type = &TREE_TYPE (*node);
4655     }
4656   else
4657     type = node;
4658
4659   if (type)
4660     {
4661       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4662         *type = build_type_copy (*type);
4663       TYPE_PACKED (*type) = 1;
4664     }
4665   else if (TREE_CODE (*node) == FIELD_DECL)
4666     DECL_PACKED (*node) = 1;
4667   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
4668      used for DECL_REGISTER.  It wouldn't mean anything anyway.  */
4669   else
4670     {
4671       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
4672       *no_add_attrs = true;
4673     }
4674
4675   return NULL_TREE;
4676 }
4677
4678 /* Handle a "nocommon" attribute; arguments as in
4679    struct attribute_spec.handler.  */
4680
4681 static tree
4682 handle_nocommon_attribute (node, name, args, flags, no_add_attrs)
4683      tree *node;
4684      tree name;
4685      tree args ATTRIBUTE_UNUSED;
4686      int flags ATTRIBUTE_UNUSED;
4687      bool *no_add_attrs;
4688 {
4689   if (TREE_CODE (*node) == VAR_DECL)
4690     DECL_COMMON (*node) = 0;
4691   else
4692     {
4693       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
4694       *no_add_attrs = true;
4695     }
4696
4697   return NULL_TREE;
4698 }
4699
4700 /* Handle a "common" attribute; arguments as in
4701    struct attribute_spec.handler.  */
4702
4703 static tree
4704 handle_common_attribute (node, name, args, flags, no_add_attrs)
4705      tree *node;
4706      tree name;
4707      tree args ATTRIBUTE_UNUSED;
4708      int flags ATTRIBUTE_UNUSED;
4709      bool *no_add_attrs;
4710 {
4711   if (TREE_CODE (*node) == VAR_DECL)
4712     DECL_COMMON (*node) = 1;
4713   else
4714     {
4715       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
4716       *no_add_attrs = true;
4717     }
4718
4719   return NULL_TREE;
4720 }
4721
4722 /* Handle a "noreturn" attribute; arguments as in
4723    struct attribute_spec.handler.  */
4724
4725 static tree
4726 handle_noreturn_attribute (node, name, args, flags, no_add_attrs)
4727      tree *node;
4728      tree name;
4729      tree args ATTRIBUTE_UNUSED;
4730      int flags ATTRIBUTE_UNUSED;
4731      bool *no_add_attrs;
4732 {
4733   tree type = TREE_TYPE (*node);
4734
4735   /* See FIXME comment in c_common_attribute_table.  */
4736   if (TREE_CODE (*node) == FUNCTION_DECL)
4737     TREE_THIS_VOLATILE (*node) = 1;
4738   else if (TREE_CODE (type) == POINTER_TYPE
4739            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4740     TREE_TYPE (*node)
4741       = build_pointer_type
4742         (build_type_variant (TREE_TYPE (type),
4743                              TREE_READONLY (TREE_TYPE (type)), 1));
4744   else
4745     {
4746       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
4747       *no_add_attrs = true;
4748     }
4749
4750   return NULL_TREE;
4751 }
4752
4753 /* Handle a "noinline" attribute; arguments as in
4754    struct attribute_spec.handler.  */
4755
4756 static tree
4757 handle_noinline_attribute (node, name, args, flags, no_add_attrs)
4758      tree *node;
4759      tree name;
4760      tree args ATTRIBUTE_UNUSED;
4761      int flags ATTRIBUTE_UNUSED;
4762      bool *no_add_attrs;
4763 {
4764   if (TREE_CODE (*node) == FUNCTION_DECL)
4765     DECL_UNINLINABLE (*node) = 1;
4766   else
4767     {
4768       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
4769       *no_add_attrs = true;
4770     }
4771
4772   return NULL_TREE;
4773 }
4774
4775 /* Handle a "always_inline" attribute; arguments as in
4776    struct attribute_spec.handler.  */
4777
4778 static tree
4779 handle_always_inline_attribute (node, name, args, flags, no_add_attrs)
4780      tree *node;
4781      tree name;
4782      tree args ATTRIBUTE_UNUSED;
4783      int flags ATTRIBUTE_UNUSED;
4784      bool *no_add_attrs;
4785 {
4786   if (TREE_CODE (*node) == FUNCTION_DECL)
4787     {
4788       /* Do nothing else, just set the attribute.  We'll get at
4789          it later with lookup_attribute.  */
4790     }
4791   else
4792     {
4793       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
4794       *no_add_attrs = true;
4795     }
4796
4797   return NULL_TREE;
4798 }
4799
4800 /* Handle a "used" attribute; arguments as in
4801    struct attribute_spec.handler.  */
4802
4803 static tree
4804 handle_used_attribute (node, name, args, flags, no_add_attrs)
4805      tree *node;
4806      tree name;
4807      tree args ATTRIBUTE_UNUSED;
4808      int flags ATTRIBUTE_UNUSED;
4809      bool *no_add_attrs;
4810 {
4811   if (TREE_CODE (*node) == FUNCTION_DECL)
4812     TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (*node))
4813       = TREE_USED (*node) = 1;
4814   else
4815     {
4816       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
4817       *no_add_attrs = true;
4818     }
4819
4820   return NULL_TREE;
4821 }
4822
4823 /* Handle a "unused" attribute; arguments as in
4824    struct attribute_spec.handler.  */
4825
4826 static tree
4827 handle_unused_attribute (node, name, args, flags, no_add_attrs)
4828      tree *node;
4829      tree name;
4830      tree args ATTRIBUTE_UNUSED;
4831      int flags;
4832      bool *no_add_attrs;
4833 {
4834   if (DECL_P (*node))
4835     {
4836       tree decl = *node;
4837
4838       if (TREE_CODE (decl) == PARM_DECL
4839           || TREE_CODE (decl) == VAR_DECL
4840           || TREE_CODE (decl) == FUNCTION_DECL
4841           || TREE_CODE (decl) == LABEL_DECL
4842           || TREE_CODE (decl) == TYPE_DECL)
4843         TREE_USED (decl) = 1;
4844       else
4845         {
4846           warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
4847           *no_add_attrs = true;
4848         }
4849     }
4850   else
4851     {
4852       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4853         *node = build_type_copy (*node);
4854       TREE_USED (*node) = 1;
4855     }
4856
4857   return NULL_TREE;
4858 }
4859
4860 /* Handle a "const" attribute; arguments as in
4861    struct attribute_spec.handler.  */
4862
4863 static tree
4864 handle_const_attribute (node, name, args, flags, no_add_attrs)
4865      tree *node;
4866      tree name;
4867      tree args ATTRIBUTE_UNUSED;
4868      int flags ATTRIBUTE_UNUSED;
4869      bool *no_add_attrs;
4870 {
4871   tree type = TREE_TYPE (*node);
4872
4873   /* See FIXME comment on noreturn in c_common_attribute_table.  */
4874   if (TREE_CODE (*node) == FUNCTION_DECL)
4875     TREE_READONLY (*node) = 1;
4876   else if (TREE_CODE (type) == POINTER_TYPE
4877            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4878     TREE_TYPE (*node)
4879       = build_pointer_type
4880         (build_type_variant (TREE_TYPE (type), 1,
4881                              TREE_THIS_VOLATILE (TREE_TYPE (type))));
4882   else
4883     {
4884       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
4885       *no_add_attrs = true;
4886     }
4887
4888   return NULL_TREE;
4889 }
4890
4891 /* Handle a "transparent_union" attribute; arguments as in
4892    struct attribute_spec.handler.  */
4893
4894 static tree
4895 handle_transparent_union_attribute (node, name, args, flags, no_add_attrs)
4896      tree *node;
4897      tree name;
4898      tree args ATTRIBUTE_UNUSED;
4899      int flags;
4900      bool *no_add_attrs;
4901 {
4902   tree decl = NULL_TREE;
4903   tree *type = NULL;
4904   int is_type = 0;
4905
4906   if (DECL_P (*node))
4907     {
4908       decl = *node;
4909       type = &TREE_TYPE (decl);
4910       is_type = TREE_CODE (*node) == TYPE_DECL;
4911     }
4912   else if (TYPE_P (*node))
4913     type = node, is_type = 1;
4914
4915   if (is_type
4916       && TREE_CODE (*type) == UNION_TYPE
4917       && (decl == 0
4918           || (TYPE_FIELDS (*type) != 0
4919               && TYPE_MODE (*type) == DECL_MODE (TYPE_FIELDS (*type)))))
4920     {
4921       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4922         *type = build_type_copy (*type);
4923       TYPE_TRANSPARENT_UNION (*type) = 1;
4924     }
4925   else if (decl != 0 && TREE_CODE (decl) == PARM_DECL
4926            && TREE_CODE (*type) == UNION_TYPE
4927            && TYPE_MODE (*type) == DECL_MODE (TYPE_FIELDS (*type)))
4928     DECL_TRANSPARENT_UNION (decl) = 1;
4929   else
4930     {
4931       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
4932       *no_add_attrs = true;
4933     }
4934
4935   return NULL_TREE;
4936 }
4937
4938 /* Handle a "constructor" attribute; arguments as in
4939    struct attribute_spec.handler.  */
4940
4941 static tree
4942 handle_constructor_attribute (node, name, args, flags, no_add_attrs)
4943      tree *node;
4944      tree name;
4945      tree args ATTRIBUTE_UNUSED;
4946      int flags ATTRIBUTE_UNUSED;
4947      bool *no_add_attrs;
4948 {
4949   tree decl = *node;
4950   tree type = TREE_TYPE (decl);
4951
4952   if (TREE_CODE (decl) == FUNCTION_DECL
4953       && TREE_CODE (type) == FUNCTION_TYPE
4954       && decl_function_context (decl) == 0)
4955     {
4956       DECL_STATIC_CONSTRUCTOR (decl) = 1;
4957       TREE_USED (decl) = 1;
4958     }
4959   else
4960     {
4961       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
4962       *no_add_attrs = true;
4963     }
4964
4965   return NULL_TREE;
4966 }
4967
4968 /* Handle a "destructor" attribute; arguments as in
4969    struct attribute_spec.handler.  */
4970
4971 static tree
4972 handle_destructor_attribute (node, name, args, flags, no_add_attrs)
4973      tree *node;
4974      tree name;
4975      tree args ATTRIBUTE_UNUSED;
4976      int flags ATTRIBUTE_UNUSED;
4977      bool *no_add_attrs;
4978 {
4979   tree decl = *node;
4980   tree type = TREE_TYPE (decl);
4981
4982   if (TREE_CODE (decl) == FUNCTION_DECL
4983       && TREE_CODE (type) == FUNCTION_TYPE
4984       && decl_function_context (decl) == 0)
4985     {
4986       DECL_STATIC_DESTRUCTOR (decl) = 1;
4987       TREE_USED (decl) = 1;
4988     }
4989   else
4990     {
4991       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
4992       *no_add_attrs = true;
4993     }
4994
4995   return NULL_TREE;
4996 }
4997
4998 /* Handle a "mode" attribute; arguments as in
4999    struct attribute_spec.handler.  */
5000
5001 static tree
5002 handle_mode_attribute (node, name, args, flags, no_add_attrs)
5003      tree *node;
5004      tree name;
5005      tree args;
5006      int flags ATTRIBUTE_UNUSED;
5007      bool *no_add_attrs;
5008 {
5009   tree type = *node;
5010
5011   *no_add_attrs = true;
5012
5013   if (TREE_CODE (TREE_VALUE (args)) != IDENTIFIER_NODE)
5014     warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
5015   else
5016     {
5017       int j;
5018       const char *p = IDENTIFIER_POINTER (TREE_VALUE (args));
5019       int len = strlen (p);
5020       enum machine_mode mode = VOIDmode;
5021       tree typefm;
5022
5023       if (len > 4 && p[0] == '_' && p[1] == '_'
5024           && p[len - 1] == '_' && p[len - 2] == '_')
5025         {
5026           char *newp = (char *) alloca (len - 1);
5027
5028           strcpy (newp, &p[2]);
5029           newp[len - 4] = '\0';
5030           p = newp;
5031         }
5032
5033       /* Change this type to have a type with the specified mode.
5034          First check for the special modes.  */
5035       if (! strcmp (p, "byte"))
5036         mode = byte_mode;
5037       else if (!strcmp (p, "word"))
5038         mode = word_mode;
5039       else if (! strcmp (p, "pointer"))
5040         mode = ptr_mode;
5041       else
5042         for (j = 0; j < NUM_MACHINE_MODES; j++)
5043           if (!strcmp (p, GET_MODE_NAME (j)))
5044             mode = (enum machine_mode) j;
5045
5046       if (mode == VOIDmode)
5047         error ("unknown machine mode `%s'", p);
5048       else if (0 == (typefm = (*lang_hooks.types.type_for_mode)
5049                      (mode, TREE_UNSIGNED (type))))
5050         error ("no data type for mode `%s'", p);
5051       else
5052         {
5053           /* If this is a vector, make sure we either have hardware
5054              support, or we can emulate it.  */
5055           if ((GET_MODE_CLASS (mode) == MODE_VECTOR_INT
5056                || GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT)
5057               && !vector_mode_valid_p (mode))
5058             {
5059               error ("unable to emulate '%s'", GET_MODE_NAME (mode));
5060               return NULL_TREE;
5061             }
5062
5063           *node = typefm;
5064           /* No need to layout the type here.  The caller should do this.  */
5065         }
5066     }
5067
5068   return NULL_TREE;
5069 }
5070
5071 /* Handle a "section" attribute; arguments as in
5072    struct attribute_spec.handler.  */
5073
5074 static tree
5075 handle_section_attribute (node, name, args, flags, no_add_attrs)
5076      tree *node;
5077      tree name ATTRIBUTE_UNUSED;
5078      tree args;
5079      int flags ATTRIBUTE_UNUSED;
5080      bool *no_add_attrs;
5081 {
5082   tree decl = *node;
5083
5084   if (targetm.have_named_sections)
5085     {
5086       if ((TREE_CODE (decl) == FUNCTION_DECL
5087            || TREE_CODE (decl) == VAR_DECL)
5088           && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
5089         {
5090           if (TREE_CODE (decl) == VAR_DECL
5091               && current_function_decl != NULL_TREE
5092               && ! TREE_STATIC (decl))
5093             {
5094               error_with_decl (decl,
5095                                "section attribute cannot be specified for local variables");
5096               *no_add_attrs = true;
5097             }
5098
5099           /* The decl may have already been given a section attribute
5100              from a previous declaration.  Ensure they match.  */
5101           else if (DECL_SECTION_NAME (decl) != NULL_TREE
5102                    && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
5103                               TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
5104             {
5105               error_with_decl (*node,
5106                                "section of `%s' conflicts with previous declaration");
5107               *no_add_attrs = true;
5108             }
5109           else
5110             DECL_SECTION_NAME (decl) = TREE_VALUE (args);
5111         }
5112       else
5113         {
5114           error_with_decl (*node,
5115                            "section attribute not allowed for `%s'");
5116           *no_add_attrs = true;
5117         }
5118     }
5119   else
5120     {
5121       error_with_decl (*node,
5122                        "section attributes are not supported for this target");
5123       *no_add_attrs = true;
5124     }
5125
5126   return NULL_TREE;
5127 }
5128
5129 /* Handle a "aligned" attribute; arguments as in
5130    struct attribute_spec.handler.  */
5131
5132 static tree
5133 handle_aligned_attribute (node, name, args, flags, no_add_attrs)
5134      tree *node;
5135      tree name ATTRIBUTE_UNUSED;
5136      tree args;
5137      int flags;
5138      bool *no_add_attrs;
5139 {
5140   tree decl = NULL_TREE;
5141   tree *type = NULL;
5142   int is_type = 0;
5143   tree align_expr = (args ? TREE_VALUE (args)
5144                      : size_int (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
5145   int i;
5146
5147   if (DECL_P (*node))
5148     {
5149       decl = *node;
5150       type = &TREE_TYPE (decl);
5151       is_type = TREE_CODE (*node) == TYPE_DECL;
5152     }
5153   else if (TYPE_P (*node))
5154     type = node, is_type = 1;
5155
5156   /* Strip any NOPs of any kind.  */
5157   while (TREE_CODE (align_expr) == NOP_EXPR
5158          || TREE_CODE (align_expr) == CONVERT_EXPR
5159          || TREE_CODE (align_expr) == NON_LVALUE_EXPR)
5160     align_expr = TREE_OPERAND (align_expr, 0);
5161
5162   if (TREE_CODE (align_expr) != INTEGER_CST)
5163     {
5164       error ("requested alignment is not a constant");
5165       *no_add_attrs = true;
5166     }
5167   else if ((i = tree_log2 (align_expr)) == -1)
5168     {
5169       error ("requested alignment is not a power of 2");
5170       *no_add_attrs = true;
5171     }
5172   else if (i > HOST_BITS_PER_INT - 2)
5173     {
5174       error ("requested alignment is too large");
5175       *no_add_attrs = true;
5176     }
5177   else if (is_type)
5178     {
5179       /* If we have a TYPE_DECL, then copy the type, so that we
5180          don't accidentally modify a builtin type.  See pushdecl.  */
5181       if (decl && TREE_TYPE (decl) != error_mark_node
5182           && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
5183         {
5184           tree tt = TREE_TYPE (decl);
5185           *type = build_type_copy (*type);
5186           DECL_ORIGINAL_TYPE (decl) = tt;
5187           TYPE_NAME (*type) = decl;
5188           TREE_USED (*type) = TREE_USED (decl);
5189           TREE_TYPE (decl) = *type;
5190         }
5191       else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5192         *type = build_type_copy (*type);
5193
5194       TYPE_ALIGN (*type) = (1 << i) * BITS_PER_UNIT;
5195       TYPE_USER_ALIGN (*type) = 1;
5196     }
5197   else if (TREE_CODE (decl) != VAR_DECL
5198            && TREE_CODE (decl) != FIELD_DECL)
5199     {
5200       error_with_decl (decl,
5201                        "alignment may not be specified for `%s'");
5202       *no_add_attrs = true;
5203     }
5204   else
5205     {
5206       DECL_ALIGN (decl) = (1 << i) * BITS_PER_UNIT;
5207       DECL_USER_ALIGN (decl) = 1;
5208     }
5209
5210   return NULL_TREE;
5211 }
5212
5213 /* Handle a "weak" attribute; arguments as in
5214    struct attribute_spec.handler.  */
5215
5216 static tree
5217 handle_weak_attribute (node, name, args, flags, no_add_attrs)
5218      tree *node;
5219      tree name ATTRIBUTE_UNUSED;
5220      tree args ATTRIBUTE_UNUSED;
5221      int flags ATTRIBUTE_UNUSED;
5222      bool *no_add_attrs ATTRIBUTE_UNUSED;
5223 {
5224   declare_weak (*node);
5225
5226   return NULL_TREE;
5227 }
5228
5229 /* Handle an "alias" attribute; arguments as in
5230    struct attribute_spec.handler.  */
5231
5232 static tree
5233 handle_alias_attribute (node, name, args, flags, no_add_attrs)
5234      tree *node;
5235      tree name;
5236      tree args;
5237      int flags ATTRIBUTE_UNUSED;
5238      bool *no_add_attrs;
5239 {
5240   tree decl = *node;
5241
5242   if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
5243       || (TREE_CODE (decl) != FUNCTION_DECL && ! DECL_EXTERNAL (decl)))
5244     {
5245       error_with_decl (decl,
5246                        "`%s' defined both normally and as an alias");
5247       *no_add_attrs = true;
5248     }
5249   else if (decl_function_context (decl) == 0)
5250     {
5251       tree id;
5252
5253       id = TREE_VALUE (args);
5254       if (TREE_CODE (id) != STRING_CST)
5255         {
5256           error ("alias arg not a string");
5257           *no_add_attrs = true;
5258           return NULL_TREE;
5259         }
5260       id = get_identifier (TREE_STRING_POINTER (id));
5261       /* This counts as a use of the object pointed to.  */
5262       TREE_USED (id) = 1;
5263
5264       if (TREE_CODE (decl) == FUNCTION_DECL)
5265         DECL_INITIAL (decl) = error_mark_node;
5266       else
5267         DECL_EXTERNAL (decl) = 0;
5268     }
5269   else
5270     {
5271       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
5272       *no_add_attrs = true;
5273     }
5274
5275   return NULL_TREE;
5276 }
5277
5278 /* Handle an "visibility" attribute; arguments as in
5279    struct attribute_spec.handler.  */
5280
5281 static tree
5282 handle_visibility_attribute (node, name, args, flags, no_add_attrs)
5283      tree *node;
5284      tree name;
5285      tree args;
5286      int flags ATTRIBUTE_UNUSED;
5287      bool *no_add_attrs;
5288 {
5289   tree decl = *node;
5290
5291   if (decl_function_context (decl) != 0 || ! TREE_PUBLIC (decl))
5292     {
5293       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
5294       *no_add_attrs = true;
5295     }
5296   else
5297     {
5298       tree id;
5299
5300       id = TREE_VALUE (args);
5301       if (TREE_CODE (id) != STRING_CST)
5302         {
5303           error ("visibility arg not a string");
5304           *no_add_attrs = true;
5305           return NULL_TREE;
5306         }
5307       if (strcmp (TREE_STRING_POINTER (id), "hidden")
5308           && strcmp (TREE_STRING_POINTER (id), "protected")
5309           && strcmp (TREE_STRING_POINTER (id), "internal"))
5310         {
5311           error ("visibility arg must be one of \"hidden\", \"protected\" or \"internal\"");
5312           *no_add_attrs = true;
5313           return NULL_TREE;
5314         }
5315     }
5316
5317   return NULL_TREE;
5318 }
5319
5320 /* Handle a "no_instrument_function" attribute; arguments as in
5321    struct attribute_spec.handler.  */
5322
5323 static tree
5324 handle_no_instrument_function_attribute (node, name, args, flags, no_add_attrs)
5325      tree *node;
5326      tree name;
5327      tree args ATTRIBUTE_UNUSED;
5328      int flags ATTRIBUTE_UNUSED;
5329      bool *no_add_attrs;
5330 {
5331   tree decl = *node;
5332
5333   if (TREE_CODE (decl) != FUNCTION_DECL)
5334     {
5335       error_with_decl (decl,
5336                        "`%s' attribute applies only to functions",
5337                        IDENTIFIER_POINTER (name));
5338       *no_add_attrs = true;
5339     }
5340   else if (DECL_INITIAL (decl))
5341     {
5342       error_with_decl (decl,
5343                        "can't set `%s' attribute after definition",
5344                        IDENTIFIER_POINTER (name));
5345       *no_add_attrs = true;
5346     }
5347   else
5348     DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
5349
5350   return NULL_TREE;
5351 }
5352
5353 /* Handle a "malloc" attribute; arguments as in
5354    struct attribute_spec.handler.  */
5355
5356 static tree
5357 handle_malloc_attribute (node, name, args, flags, no_add_attrs)
5358      tree *node;
5359      tree name;
5360      tree args ATTRIBUTE_UNUSED;
5361      int flags ATTRIBUTE_UNUSED;
5362      bool *no_add_attrs;
5363 {
5364   if (TREE_CODE (*node) == FUNCTION_DECL)
5365     DECL_IS_MALLOC (*node) = 1;
5366   /* ??? TODO: Support types.  */
5367   else
5368     {
5369       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
5370       *no_add_attrs = true;
5371     }
5372
5373   return NULL_TREE;
5374 }
5375
5376 /* Handle a "no_limit_stack" attribute; arguments as in
5377    struct attribute_spec.handler.  */
5378
5379 static tree
5380 handle_no_limit_stack_attribute (node, name, args, flags, no_add_attrs)
5381      tree *node;
5382      tree name;
5383      tree args ATTRIBUTE_UNUSED;
5384      int flags ATTRIBUTE_UNUSED;
5385      bool *no_add_attrs;
5386 {
5387   tree decl = *node;
5388
5389   if (TREE_CODE (decl) != FUNCTION_DECL)
5390     {
5391       error_with_decl (decl,
5392                        "`%s' attribute applies only to functions",
5393                        IDENTIFIER_POINTER (name));
5394       *no_add_attrs = true;
5395     }
5396   else if (DECL_INITIAL (decl))
5397     {
5398       error_with_decl (decl,
5399                        "can't set `%s' attribute after definition",
5400                        IDENTIFIER_POINTER (name));
5401       *no_add_attrs = true;
5402     }
5403   else
5404     DECL_NO_LIMIT_STACK (decl) = 1;
5405
5406   return NULL_TREE;
5407 }
5408
5409 /* Handle a "pure" attribute; arguments as in
5410    struct attribute_spec.handler.  */
5411
5412 static tree
5413 handle_pure_attribute (node, name, args, flags, no_add_attrs)
5414      tree *node;
5415      tree name;
5416      tree args ATTRIBUTE_UNUSED;
5417      int flags ATTRIBUTE_UNUSED;
5418      bool *no_add_attrs;
5419 {
5420   if (TREE_CODE (*node) == FUNCTION_DECL)
5421     DECL_IS_PURE (*node) = 1;
5422   /* ??? TODO: Support types.  */
5423   else
5424     {
5425       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
5426       *no_add_attrs = true;
5427     }
5428
5429   return NULL_TREE;
5430 }
5431
5432 /* Handle a "deprecated" attribute; arguments as in
5433    struct attribute_spec.handler.  */
5434
5435 static tree
5436 handle_deprecated_attribute (node, name, args, flags, no_add_attrs)
5437      tree *node;
5438      tree name;
5439      tree args ATTRIBUTE_UNUSED;
5440      int flags;
5441      bool *no_add_attrs;
5442 {
5443   tree type = NULL_TREE;
5444   int warn = 0;
5445   const char *what = NULL;
5446
5447   if (DECL_P (*node))
5448     {
5449       tree decl = *node;
5450       type = TREE_TYPE (decl);
5451
5452       if (TREE_CODE (decl) == TYPE_DECL
5453           || TREE_CODE (decl) == PARM_DECL
5454           || TREE_CODE (decl) == VAR_DECL
5455           || TREE_CODE (decl) == FUNCTION_DECL
5456           || TREE_CODE (decl) == FIELD_DECL)
5457         TREE_DEPRECATED (decl) = 1;
5458       else
5459         warn = 1;
5460     }
5461   else if (TYPE_P (*node))
5462     {
5463       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5464         *node = build_type_copy (*node);
5465       TREE_DEPRECATED (*node) = 1;
5466       type = *node;
5467     }
5468   else
5469     warn = 1;
5470
5471   if (warn)
5472     {
5473       *no_add_attrs = true;
5474       if (type && TYPE_NAME (type))
5475         {
5476           if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
5477             what = IDENTIFIER_POINTER (TYPE_NAME (*node));
5478           else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
5479                    && DECL_NAME (TYPE_NAME (type)))
5480             what = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type)));
5481         }
5482       if (what)
5483         warning ("`%s' attribute ignored for `%s'",
5484                   IDENTIFIER_POINTER (name), what);
5485       else
5486         warning ("`%s' attribute ignored",
5487                       IDENTIFIER_POINTER (name));
5488     }
5489
5490   return NULL_TREE;
5491 }
5492
5493 /* Keep a list of vector type nodes we created in handle_vector_size_attribute,
5494    to prevent us from duplicating type nodes unnecessarily.
5495    The normal mechanism to prevent duplicates is to use type_hash_canon, but
5496    since we want to distinguish types that are essentially identical (except
5497    for their debug representation), we use a local list here.  */
5498 static tree vector_type_node_list = 0;
5499
5500 /* Handle a "vector_size" attribute; arguments as in
5501    struct attribute_spec.handler.  */
5502
5503 static tree
5504 handle_vector_size_attribute (node, name, args, flags, no_add_attrs)
5505      tree *node;
5506      tree name;
5507      tree args;
5508      int flags ATTRIBUTE_UNUSED;
5509      bool *no_add_attrs;
5510 {
5511   unsigned HOST_WIDE_INT vecsize, nunits;
5512   enum machine_mode mode, orig_mode, new_mode;
5513   tree type = *node, new_type = NULL_TREE;
5514   tree type_list_node;
5515
5516   *no_add_attrs = true;
5517
5518   if (! host_integerp (TREE_VALUE (args), 1))
5519     {
5520       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
5521       return NULL_TREE;
5522     }
5523
5524   /* Get the vector size (in bytes).  */
5525   vecsize = tree_low_cst (TREE_VALUE (args), 1);
5526
5527   /* We need to provide for vector pointers, vector arrays, and
5528      functions returning vectors.  For example:
5529
5530        __attribute__((vector_size(16))) short *foo;
5531
5532      In this case, the mode is SI, but the type being modified is
5533      HI, so we need to look further.  */
5534
5535   while (POINTER_TYPE_P (type)
5536          || TREE_CODE (type) == FUNCTION_TYPE
5537          || TREE_CODE (type) == ARRAY_TYPE)
5538     type = TREE_TYPE (type);
5539
5540   /* Get the mode of the type being modified.  */
5541   orig_mode = TYPE_MODE (type);
5542
5543   if (TREE_CODE (type) == RECORD_TYPE
5544       || (GET_MODE_CLASS (orig_mode) != MODE_FLOAT
5545           && GET_MODE_CLASS (orig_mode) != MODE_INT)
5546       || ! host_integerp (TYPE_SIZE_UNIT (type), 1))
5547     {
5548       error ("invalid vector type for attribute `%s'",
5549              IDENTIFIER_POINTER (name));
5550       return NULL_TREE;
5551     }
5552
5553   /* Calculate how many units fit in the vector.  */
5554   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
5555
5556   /* Find a suitably sized vector.  */
5557   new_mode = VOIDmode;
5558   for (mode = GET_CLASS_NARROWEST_MODE (GET_MODE_CLASS (orig_mode) == MODE_INT
5559                                         ? MODE_VECTOR_INT
5560                                         : MODE_VECTOR_FLOAT);
5561        mode != VOIDmode;
5562        mode = GET_MODE_WIDER_MODE (mode))
5563     if (vecsize == GET_MODE_SIZE (mode)
5564         && nunits == (unsigned HOST_WIDE_INT) GET_MODE_NUNITS (mode))
5565       {
5566         new_mode = mode;
5567         break;
5568       }
5569
5570     if (new_mode == VOIDmode)
5571     {
5572       error ("no vector mode with the size and type specified could be found");
5573       return NULL_TREE;
5574     }
5575
5576   for (type_list_node = vector_type_node_list; type_list_node;
5577        type_list_node = TREE_CHAIN (type_list_node))
5578     {
5579       tree other_type = TREE_VALUE (type_list_node);
5580       tree record = TYPE_DEBUG_REPRESENTATION_TYPE (other_type);
5581       tree fields = TYPE_FIELDS (record);
5582       tree field_type = TREE_TYPE (fields);
5583       tree array_type = TREE_TYPE (field_type);
5584       if (TREE_CODE (fields) != FIELD_DECL
5585           || TREE_CODE (field_type) != ARRAY_TYPE)
5586         abort ();
5587
5588       if (TYPE_MODE (other_type) == mode && type == array_type)
5589         {
5590           new_type = other_type;
5591           break;
5592         }
5593     }
5594
5595   if (new_type == NULL_TREE)
5596     {
5597       tree index, array, rt, list_node;
5598
5599       new_type = (*lang_hooks.types.type_for_mode) (new_mode,
5600                                                     TREE_UNSIGNED (type));
5601
5602       if (!new_type)
5603         {
5604           error ("no vector mode with the size and type specified could be found");
5605           return NULL_TREE;
5606         }
5607
5608       new_type = build_type_copy (new_type);
5609
5610       /* If this is a vector, make sure we either have hardware
5611          support, or we can emulate it.  */
5612       if ((GET_MODE_CLASS (mode) == MODE_VECTOR_INT
5613            || GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT)
5614           && !vector_mode_valid_p (mode))
5615         {
5616           error ("unable to emulate '%s'", GET_MODE_NAME (mode));
5617           return NULL_TREE;
5618         }
5619
5620       /* Set the debug information here, because this is the only
5621          place where we know the underlying type for a vector made
5622          with vector_size.  For debugging purposes we pretend a vector
5623          is an array within a structure.  */
5624       index = build_int_2 (TYPE_VECTOR_SUBPARTS (new_type) - 1, 0);
5625       array = build_array_type (type, build_index_type (index));
5626       rt = make_node (RECORD_TYPE);
5627
5628       TYPE_FIELDS (rt) = build_decl (FIELD_DECL, get_identifier ("f"), array);
5629       DECL_CONTEXT (TYPE_FIELDS (rt)) = rt;
5630       layout_type (rt);
5631       TYPE_DEBUG_REPRESENTATION_TYPE (new_type) = rt;
5632
5633       list_node = build_tree_list (NULL, new_type);
5634       TREE_CHAIN (list_node) = vector_type_node_list;
5635       vector_type_node_list = list_node;
5636     }
5637
5638   /* Build back pointers if needed.  */
5639   *node = vector_size_helper (*node, new_type);
5640
5641   return NULL_TREE;
5642 }
5643
5644 /* HACK.  GROSS.  This is absolutely disgusting.  I wish there was a
5645    better way.
5646
5647    If we requested a pointer to a vector, build up the pointers that
5648    we stripped off while looking for the inner type.  Similarly for
5649    return values from functions.
5650
5651    The argument "type" is the top of the chain, and "bottom" is the
5652    new type which we will point to.  */
5653
5654 static tree
5655 vector_size_helper (type, bottom)
5656      tree type, bottom;
5657 {
5658   tree inner, outer;
5659
5660   if (POINTER_TYPE_P (type))
5661     {
5662       inner = vector_size_helper (TREE_TYPE (type), bottom);
5663       outer = build_pointer_type (inner);
5664     }
5665   else if (TREE_CODE (type) == ARRAY_TYPE)
5666     {
5667       inner = vector_size_helper (TREE_TYPE (type), bottom);
5668       outer = build_array_type (inner, TYPE_VALUES (type));
5669     }
5670   else if (TREE_CODE (type) == FUNCTION_TYPE)
5671     {
5672       inner = vector_size_helper (TREE_TYPE (type), bottom);
5673       outer = build_function_type (inner, TYPE_VALUES (type));
5674     }
5675   else
5676     return bottom;
5677
5678   TREE_READONLY (outer) = TREE_READONLY (type);
5679   TREE_THIS_VOLATILE (outer) = TREE_THIS_VOLATILE (type);
5680
5681   return outer;
5682 }
5683
5684 /* Handle the "nonnull" attribute.  */
5685 static tree
5686 handle_nonnull_attribute (node, name, args, flags, no_add_attrs)
5687      tree *node;
5688      tree name ATTRIBUTE_UNUSED;
5689      tree args;
5690      int flags ATTRIBUTE_UNUSED;
5691      bool *no_add_attrs;
5692 {
5693   tree type = *node;
5694   unsigned HOST_WIDE_INT attr_arg_num;
5695
5696   /* If no arguments are specified, all pointer arguments should be
5697      non-null.  Veryify a full prototype is given so that the arguments
5698      will have the correct types when we actually check them later.  */
5699   if (! args)
5700     {
5701       if (! TYPE_ARG_TYPES (type))
5702         {
5703           error ("nonnull attribute without arguments on a non-prototype");
5704           *no_add_attrs = true;
5705         }
5706       return NULL_TREE;
5707     }
5708
5709   /* Argument list specified.  Verify that each argument number references
5710      a pointer argument.  */
5711   for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
5712     {
5713       tree argument;
5714       unsigned HOST_WIDE_INT arg_num, ck_num;
5715
5716       if (! get_nonnull_operand (TREE_VALUE (args), &arg_num))
5717         {
5718           error ("nonnull argument has invalid operand number (arg %lu)",
5719                  (unsigned long) attr_arg_num);
5720           *no_add_attrs = true;
5721           return NULL_TREE;
5722         }
5723
5724       argument = TYPE_ARG_TYPES (type);
5725       if (argument)
5726         {
5727           for (ck_num = 1; ; ck_num++)
5728             {
5729               if (! argument || ck_num == arg_num)
5730                 break;
5731               argument = TREE_CHAIN (argument);
5732             }
5733
5734           if (! argument
5735               || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
5736             {
5737               error ("nonnull argument with out-of-range operand number (arg %lu, operand %lu)",
5738                      (unsigned long) attr_arg_num, (unsigned long) arg_num);
5739               *no_add_attrs = true;
5740               return NULL_TREE;
5741             }
5742
5743           if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
5744             {
5745               error ("nonnull argument references non-pointer operand (arg %lu, operand %lu)",
5746                    (unsigned long) attr_arg_num, (unsigned long) arg_num);
5747               *no_add_attrs = true;
5748               return NULL_TREE;
5749             }
5750         }
5751     }
5752
5753   return NULL_TREE;
5754 }
5755
5756 /* Check the argument list of a function call for null in argument slots
5757    that are marked as requiring a non-null pointer argument.  */
5758
5759 static void
5760 check_function_nonnull (attrs, params)
5761      tree attrs;
5762      tree params;
5763 {
5764   tree a, args, param;
5765   int param_num;
5766
5767   for (a = attrs; a; a = TREE_CHAIN (a))
5768     {
5769       if (is_attribute_p ("nonnull", TREE_PURPOSE (a)))
5770         {
5771           args = TREE_VALUE (a);
5772
5773           /* Walk the argument list.  If we encounter an argument number we
5774              should check for non-null, do it.  If the attribute has no args,
5775              then every pointer argument is checked (in which case the check
5776              for pointer type is done in check_nonnull_arg).  */
5777           for (param = params, param_num = 1; ;
5778                param_num++, param = TREE_CHAIN (param))
5779             {
5780               if (! param)
5781                 break;
5782               if (! args || nonnull_check_p (args, param_num))
5783                 check_function_arguments_recurse (check_nonnull_arg, NULL,
5784                                                   TREE_VALUE (param),
5785                                                   param_num);
5786             }
5787         }
5788     }
5789 }
5790
5791 /* Helper for check_function_nonnull; given a list of operands which
5792    must be non-null in ARGS, determine if operand PARAM_NUM should be
5793    checked.  */
5794
5795 static bool
5796 nonnull_check_p (args, param_num)
5797      tree args;
5798      unsigned HOST_WIDE_INT param_num;
5799 {
5800   unsigned HOST_WIDE_INT arg_num;
5801
5802   for (; args; args = TREE_CHAIN (args))
5803     {
5804       if (! get_nonnull_operand (TREE_VALUE (args), &arg_num))
5805         abort ();
5806
5807       if (arg_num == param_num)
5808         return true;
5809     }
5810   return false;
5811 }
5812
5813 /* Check that the function argument PARAM (which is operand number
5814    PARAM_NUM) is non-null.  This is called by check_function_nonnull
5815    via check_function_arguments_recurse.  */
5816
5817 static void
5818 check_nonnull_arg (ctx, param, param_num)
5819      void *ctx ATTRIBUTE_UNUSED;
5820      tree param;
5821      unsigned HOST_WIDE_INT param_num;
5822 {
5823   /* Just skip checking the argument if it's not a pointer.  This can
5824      happen if the "nonnull" attribute was given without an operand
5825      list (which means to check every pointer argument).  */
5826
5827   if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE)
5828     return;
5829
5830   if (integer_zerop (param))
5831     warning ("null argument where non-null required (arg %lu)",
5832              (unsigned long) param_num);
5833 }
5834
5835 /* Helper for nonnull attribute handling; fetch the operand number
5836    from the attribute argument list.  */
5837
5838 static bool
5839 get_nonnull_operand (arg_num_expr, valp)
5840      tree arg_num_expr;
5841      unsigned HOST_WIDE_INT *valp;
5842 {
5843   /* Strip any conversions from the arg number and verify they
5844      are constants.  */
5845   while (TREE_CODE (arg_num_expr) == NOP_EXPR
5846          || TREE_CODE (arg_num_expr) == CONVERT_EXPR
5847          || TREE_CODE (arg_num_expr) == NON_LVALUE_EXPR)
5848     arg_num_expr = TREE_OPERAND (arg_num_expr, 0);
5849
5850   if (TREE_CODE (arg_num_expr) != INTEGER_CST
5851       || TREE_INT_CST_HIGH (arg_num_expr) != 0)
5852     return false;
5853
5854   *valp = TREE_INT_CST_LOW (arg_num_expr);
5855   return true;
5856 }
5857
5858 /* Handle a "nothrow" attribute; arguments as in
5859    struct attribute_spec.handler.  */
5860
5861 static tree
5862 handle_nothrow_attribute (node, name, args, flags, no_add_attrs)
5863      tree *node;
5864      tree name;
5865      tree args ATTRIBUTE_UNUSED;
5866      int flags ATTRIBUTE_UNUSED;
5867      bool *no_add_attrs;
5868 {
5869   if (TREE_CODE (*node) == FUNCTION_DECL)
5870     TREE_NOTHROW (*node) = 1;
5871   /* ??? TODO: Support types.  */
5872   else
5873     {
5874       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
5875       *no_add_attrs = true;
5876     }
5877
5878   return NULL_TREE;
5879 }
5880 \f
5881 /* Check for valid arguments being passed to a function.  */
5882 void
5883 check_function_arguments (attrs, params)
5884      tree attrs;
5885      tree params;
5886 {
5887   /* Check for null being passed in a pointer argument that must be
5888      non-null.  We also need to do this if format checking is enabled.  */
5889
5890   if (warn_nonnull)
5891     check_function_nonnull (attrs, params);
5892
5893   /* Check for errors in format strings.  */
5894
5895   if (warn_format)
5896     check_function_format (NULL, attrs, params);
5897 }
5898
5899 /* Generic argument checking recursion routine.  PARAM is the argument to
5900    be checked.  PARAM_NUM is the number of the argument.  CALLBACK is invoked
5901    once the argument is resolved.  CTX is context for the callback.  */
5902 void
5903 check_function_arguments_recurse (callback, ctx, param, param_num)
5904      void (*callback) PARAMS ((void *, tree, unsigned HOST_WIDE_INT));
5905      void *ctx;
5906      tree param;
5907      unsigned HOST_WIDE_INT param_num;
5908 {
5909   if (TREE_CODE (param) == NOP_EXPR)
5910     {
5911       /* Strip coercion.  */
5912       check_function_arguments_recurse (callback, ctx,
5913                                         TREE_OPERAND (param, 0), param_num);
5914       return;
5915     }
5916
5917   if (TREE_CODE (param) == CALL_EXPR)
5918     {
5919       tree type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (param, 0)));
5920       tree attrs;
5921       bool found_format_arg = false;
5922
5923       /* See if this is a call to a known internationalization function
5924          that modifies a format arg.  Such a function may have multiple
5925          format_arg attributes (for example, ngettext).  */
5926
5927       for (attrs = TYPE_ATTRIBUTES (type);
5928            attrs;
5929            attrs = TREE_CHAIN (attrs))
5930         if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs)))
5931           {
5932             tree inner_args;
5933             tree format_num_expr;
5934             int format_num;
5935             int i;
5936
5937             /* Extract the argument number, which was previously checked
5938                to be valid.  */
5939             format_num_expr = TREE_VALUE (TREE_VALUE (attrs));
5940             while (TREE_CODE (format_num_expr) == NOP_EXPR
5941                    || TREE_CODE (format_num_expr) == CONVERT_EXPR
5942                    || TREE_CODE (format_num_expr) == NON_LVALUE_EXPR)
5943               format_num_expr = TREE_OPERAND (format_num_expr, 0);
5944
5945             if (TREE_CODE (format_num_expr) != INTEGER_CST
5946                 || TREE_INT_CST_HIGH (format_num_expr) != 0)
5947               abort ();
5948
5949             format_num = TREE_INT_CST_LOW (format_num_expr);
5950
5951             for (inner_args = TREE_OPERAND (param, 1), i = 1;
5952                  inner_args != 0;
5953                  inner_args = TREE_CHAIN (inner_args), i++)
5954               if (i == format_num)
5955                 {
5956                   check_function_arguments_recurse (callback, ctx,
5957                                                     TREE_VALUE (inner_args),
5958                                                     param_num);
5959                   found_format_arg = true;
5960                   break;
5961                 }
5962           }
5963
5964       /* If we found a format_arg attribute and did a recursive check,
5965          we are done with checking this argument.  Otherwise, we continue
5966          and this will be considered a non-literal.  */
5967       if (found_format_arg)
5968         return;
5969     }
5970
5971   if (TREE_CODE (param) == COND_EXPR)
5972     {
5973       /* Check both halves of the conditional expression.  */
5974       check_function_arguments_recurse (callback, ctx,
5975                                         TREE_OPERAND (param, 1), param_num);
5976       check_function_arguments_recurse (callback, ctx,
5977                                         TREE_OPERAND (param, 2), param_num);
5978       return;
5979     }
5980
5981   (*callback) (ctx, param, param_num);
5982 }
5983
5984 #include "gt-c-common.h"