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, 2003, 2004, 2005 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, 51 Franklin Street, Fifth Floor, Boston, MA
  20 02110-1301, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "intl.h"
  27 #include "tree.h"
  28 #include "flags.h"
  29 #include "output.h"
  30 #include "c-pragma.h"
  31 #include "rtl.h"
  32 #include "ggc.h"
  33 #include "varray.h"
  34 #include "expr.h"
  35 #include "c-common.h"
  36 #include "diagnostic.h"
  37 #include "tm_p.h"
  38 #include "obstack.h"
  39 #include "cpplib.h"
  40 #include "target.h"
  41 #include "langhooks.h"
  42 #include "tree-inline.h"
  43 #include "c-tree.h"
  44 #include "toplev.h"
  45 #include "tree-iterator.h"
  46 #include "hashtab.h"
  47 #include "tree-mudflap.h"
  48 #include "opts.h"
  49 #include "real.h"
  50 #include "cgraph.h"
  51
  52 cpp_reader *parse_in;           /* Declared in c-pragma.h.  */
  53
  54 /* We let tm.h override the types used here, to handle trivial differences
  55    such as the choice of unsigned int or long unsigned int for size_t.
  56    When machines start needing nontrivial differences in the size type,
  57    it would be best to do something here to figure out automatically
  58    from other information what type to use.  */
  59
  60 #ifndef SIZE_TYPE
  61 #define SIZE_TYPE "long unsigned int"
  62 #endif
  63
  64 #ifndef PID_TYPE
  65 #define PID_TYPE "int"
  66 #endif
  67
  68 #ifndef WCHAR_TYPE
  69 #define WCHAR_TYPE "int"
  70 #endif
  71
  72 /* WCHAR_TYPE gets overridden by -fshort-wchar.  */
  73 #define MODIFIED_WCHAR_TYPE \
  74         (flag_short_wchar ? "short unsigned int" : WCHAR_TYPE)
  75
  76 #ifndef PTRDIFF_TYPE
  77 #define PTRDIFF_TYPE "long int"
  78 #endif
  79
  80 #ifndef WINT_TYPE
  81 #define WINT_TYPE "unsigned int"
  82 #endif
  83
  84 #ifndef INTMAX_TYPE
  85 #define INTMAX_TYPE ((INT_TYPE_SIZE == LONG_LONG_TYPE_SIZE)     \
  86                      ? "int"                                    \
  87                      : ((LONG_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \
  88                         ? "long int"                            \
  89                         : "long long int"))
  90 #endif
  91
  92 #ifndef UINTMAX_TYPE
  93 #define UINTMAX_TYPE ((INT_TYPE_SIZE == LONG_LONG_TYPE_SIZE)    \
  94                      ? "unsigned int"                           \
  95                      : ((LONG_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \
  96                         ? "long unsigned int"                   \
  97                         : "long long unsigned int"))
  98 #endif
  99
 100 /* The following symbols are subsumed in the c_global_trees array, and
 101    listed here individually for documentation purposes.
 102
 103    INTEGER_TYPE and REAL_TYPE nodes for the standard data types.
 104
 105         tree short_integer_type_node;
 106         tree long_integer_type_node;
 107         tree long_long_integer_type_node;
 108
 109         tree short_unsigned_type_node;
 110         tree long_unsigned_type_node;
 111         tree long_long_unsigned_type_node;
 112
 113         tree truthvalue_type_node;
 114         tree truthvalue_false_node;
 115         tree truthvalue_true_node;
 116
 117         tree ptrdiff_type_node;
 118
 119         tree unsigned_char_type_node;
 120         tree signed_char_type_node;
 121         tree wchar_type_node;
 122         tree signed_wchar_type_node;
 123         tree unsigned_wchar_type_node;
 124
 125         tree float_type_node;
 126         tree double_type_node;
 127         tree long_double_type_node;
 128
 129         tree complex_integer_type_node;
 130         tree complex_float_type_node;
 131         tree complex_double_type_node;
 132         tree complex_long_double_type_node;
 133
 134         tree intQI_type_node;
 135         tree intHI_type_node;
 136         tree intSI_type_node;
 137         tree intDI_type_node;
 138         tree intTI_type_node;
 139
 140         tree unsigned_intQI_type_node;
 141         tree unsigned_intHI_type_node;
 142         tree unsigned_intSI_type_node;
 143         tree unsigned_intDI_type_node;
 144         tree unsigned_intTI_type_node;
 145
 146         tree widest_integer_literal_type_node;
 147         tree widest_unsigned_literal_type_node;
 148
 149    Nodes for types `void *' and `const void *'.
 150
 151         tree ptr_type_node, const_ptr_type_node;
 152
 153    Nodes for types `char *' and `const char *'.
 154
 155         tree string_type_node, const_string_type_node;
 156
 157    Type `char[SOMENUMBER]'.
 158    Used when an array of char is needed and the size is irrelevant.
 159
 160         tree char_array_type_node;
 161
 162    Type `int[SOMENUMBER]' or something like it.
 163    Used when an array of int needed and the size is irrelevant.
 164
 165         tree int_array_type_node;
 166
 167    Type `wchar_t[SOMENUMBER]' or something like it.
 168    Used when a wide string literal is created.
 169
 170         tree wchar_array_type_node;
 171
 172    Type `int ()' -- used for implicit declaration of functions.
 173
 174         tree default_function_type;
 175
 176    A VOID_TYPE node, packaged in a TREE_LIST.
 177
 178         tree void_list_node;
 179
 180   The lazily created VAR_DECLs for __FUNCTION__, __PRETTY_FUNCTION__,
 181   and __func__. (C doesn't generate __FUNCTION__ and__PRETTY_FUNCTION__
 182   VAR_DECLS, but C++ does.)
 183
 184         tree function_name_decl_node;
 185         tree pretty_function_name_decl_node;
 186         tree c99_function_name_decl_node;
 187
 188   Stack of nested function name VAR_DECLs.
 189
 190         tree saved_function_name_decls;
 191
 192 */
 193
 194 tree c_global_trees[CTI_MAX];
 195 \f
 196 /* Switches common to the C front ends.  */
 197
 198 /* Nonzero if prepreprocessing only.  */
 199
 200 int flag_preprocess_only;
 201
 202 /* Nonzero means don't output line number information.  */
 203
 204 char flag_no_line_commands;
 205
 206 /* Nonzero causes -E output not to be done, but directives such as
 207    #define that have side effects are still obeyed.  */
 208
 209 char flag_no_output;
 210
 211 /* Nonzero means dump macros in some fashion.  */
 212
 213 char flag_dump_macros;
 214
 215 /* Nonzero means pass #include lines through to the output.  */
 216
 217 char flag_dump_includes;
 218
 219 /* Nonzero means process PCH files while preprocessing.  */
 220
 221 bool flag_pch_preprocess;
 222
 223 /* The file name to which we should write a precompiled header, or
 224    NULL if no header will be written in this compile.  */
 225
 226 const char *pch_file;
 227
 228 /* Nonzero if an ISO standard was selected.  It rejects macros in the
 229    user's namespace.  */
 230 int flag_iso;
 231
 232 /* Nonzero if -undef was given.  It suppresses target built-in macros
 233    and assertions.  */
 234 int flag_undef;
 235
 236 /* Nonzero means don't recognize the non-ANSI builtin functions.  */
 237
 238 int flag_no_builtin;
 239
 240 /* Nonzero means don't recognize the non-ANSI builtin functions.
 241    -ansi sets this.  */
 242
 243 int flag_no_nonansi_builtin;
 244
 245 /* Nonzero means give `double' the same size as `float'.  */
 246
 247 int flag_short_double;
 248
 249 /* Nonzero means give `wchar_t' the same size as `short'.  */
 250
 251 int flag_short_wchar;
 252
 253 /* Nonzero means allow Microsoft extensions without warnings or errors.  */
 254 int flag_ms_extensions;
 255
 256 /* Nonzero means don't recognize the keyword `asm'.  */
 257
 258 int flag_no_asm;
 259
 260 /* Nonzero means give string constants the type `const char *', as mandated
 261    by the standard.  */
 262
 263 int flag_const_strings;
 264
 265 /* Nonzero means to treat bitfields as signed unless they say `unsigned'.  */
 266
 267 int flag_signed_bitfields = 1;
 268
 269 /* Nonzero means warn about deprecated conversion from string constant to
 270    `char *'.  */
 271
 272 int warn_write_strings;
 273
 274 /* Warn about #pragma directives that are not recognized.  */
 275
 276 int warn_unknown_pragmas; /* Tri state variable.  */
 277
 278 /* Warn about format/argument anomalies in calls to formatted I/O functions
 279    (*printf, *scanf, strftime, strfmon, etc.).  */
 280
 281 int warn_format;
 282
 283 /* Warn about using __null (as NULL in C++) as sentinel.  For code compiled
 284    with GCC this doesn't matter as __null is guaranteed to have the right
 285    size.  */
 286
 287 int warn_strict_null_sentinel;
 288
 289 /* Zero means that faster, ...NonNil variants of objc_msgSend...
 290    calls will be used in ObjC; passing nil receivers to such calls
 291    will most likely result in crashes.  */
 292 int flag_nil_receivers = 1;
 293
 294 /* Nonzero means that code generation will be altered to support
 295    "zero-link" execution.  This currently affects ObjC only, but may
 296    affect other languages in the future.  */
 297 int flag_zero_link = 0;
 298
 299 /* Nonzero means emit an '__OBJC, __image_info' for the current translation
 300    unit.  It will inform the ObjC runtime that class definition(s) herein
 301    contained are to replace one(s) previously loaded.  */
 302 int flag_replace_objc_classes = 0;
 303
 304 /* C/ObjC language option variables.  */
 305
 306
 307 /* Nonzero means allow type mismatches in conditional expressions;
 308    just make their values `void'.  */
 309
 310 int flag_cond_mismatch;
 311
 312 /* Nonzero means enable C89 Amendment 1 features.  */
 313
 314 int flag_isoc94;
 315
 316 /* Nonzero means use the ISO C99 dialect of C.  */
 317
 318 int flag_isoc99;
 319
 320 /* Nonzero means that we have builtin functions, and main is an int.  */
 321
 322 int flag_hosted = 1;
 323
 324 /* Warn if main is suspicious.  */
 325
 326 int warn_main;
 327
 328
 329 /* ObjC language option variables.  */
 330
 331
 332 /* Open and close the file for outputting class declarations, if
 333    requested (ObjC).  */
 334
 335 int flag_gen_declaration;
 336
 337 /* Generate code for GNU or NeXT runtime environment.  */
 338
 339 #ifdef NEXT_OBJC_RUNTIME
 340 int flag_next_runtime = 1;
 341 #else
 342 int flag_next_runtime = 0;
 343 #endif
 344
 345 /* Tells the compiler that this is a special run.  Do not perform any
 346    compiling, instead we are to test some platform dependent features
 347    and output a C header file with appropriate definitions.  */
 348
 349 int print_struct_values;
 350
 351 /* ???.  Undocumented.  */
 352
 353 const char *constant_string_class_name;
 354
 355
 356 /* C++ language option variables.  */
 357
 358
 359 /* Nonzero means don't recognize any extension keywords.  */
 360
 361 int flag_no_gnu_keywords;
 362
 363 /* Nonzero means do emit exported implementations of functions even if
 364    they can be inlined.  */
 365
 366 int flag_implement_inlines = 1;
 367
 368 /* Nonzero means that implicit instantiations will be emitted if needed.  */
 369
 370 int flag_implicit_templates = 1;
 371
 372 /* Nonzero means that implicit instantiations of inline templates will be
 373    emitted if needed, even if instantiations of non-inline templates
 374    aren't.  */
 375
 376 int flag_implicit_inline_templates = 1;
 377
 378 /* Nonzero means generate separate instantiation control files and
 379    juggle them at link time.  */
 380
 381 int flag_use_repository;
 382
 383 /* Nonzero if we want to issue diagnostics that the standard says are not
 384    required.  */
 385
 386 int flag_optional_diags = 1;
 387
 388 /* Nonzero means we should attempt to elide constructors when possible.  */
 389
 390 int flag_elide_constructors = 1;
 391
 392 /* Nonzero means that member functions defined in class scope are
 393    inline by default.  */
 394
 395 int flag_default_inline = 1;
 396
 397 /* Controls whether compiler generates 'type descriptor' that give
 398    run-time type information.  */
 399
 400 int flag_rtti = 1;
 401
 402 /* Nonzero if we want to conserve space in the .o files.  We do this
 403    by putting uninitialized data and runtime initialized data into
 404    .common instead of .data at the expense of not flagging multiple
 405    definitions.  */
 406
 407 int flag_conserve_space;
 408
 409 /* Nonzero if we want to obey access control semantics.  */
 410
 411 int flag_access_control = 1;
 412
 413 /* Nonzero if we want to check the return value of new and avoid calling
 414    constructors if it is a null pointer.  */
 415
 416 int flag_check_new;
 417
 418 /* Nonzero if we want the new ISO rules for pushing a new scope for `for'
 419    initialization variables.
 420    0: Old rules, set by -fno-for-scope.
 421    2: New ISO rules, set by -ffor-scope.
 422    1: Try to implement new ISO rules, but with backup compatibility
 423    (and warnings).  This is the default, for now.  */
 424
 425 int flag_new_for_scope = 1;
 426
 427 /* Nonzero if we want to emit defined symbols with common-like linkage as
 428    weak symbols where possible, in order to conform to C++ semantics.
 429    Otherwise, emit them as local symbols.  */
 430
 431 int flag_weak = 1;
 432
 433 /* 0 means we want the preprocessor to not emit line directives for
 434    the current working directory.  1 means we want it to do it.  -1
 435    means we should decide depending on whether debugging information
 436    is being emitted or not.  */
 437
 438 int flag_working_directory = -1;
 439
 440 /* Nonzero to use __cxa_atexit, rather than atexit, to register
 441    destructors for local statics and global objects.  */
 442
 443 int flag_use_cxa_atexit = DEFAULT_USE_CXA_ATEXIT;
 444
 445 /* Nonzero means make the default pedwarns warnings instead of errors.
 446    The value of this flag is ignored if -pedantic is specified.  */
 447
 448 int flag_permissive;
 449
 450 /* Nonzero means to implement standard semantics for exception
 451    specifications, calling unexpected if an exception is thrown that
 452    doesn't match the specification.  Zero means to treat them as
 453    assertions and optimize accordingly, but not check them.  */
 454
 455 int flag_enforce_eh_specs = 1;
 456
 457 /* Nonzero means to generate thread-safe code for initializing local
 458    statics.  */
 459
 460 int flag_threadsafe_statics = 1;
 461
 462 /* Nonzero means warn about implicit declarations.  */
 463
 464 int warn_implicit = 1;
 465
 466 /* Maximum template instantiation depth.  This limit is rather
 467    arbitrary, but it exists to limit the time it takes to notice
 468    infinite template instantiations.  */
 469
 470 int max_tinst_depth = 500;
 471
 472
 473
 474 /* The elements of `ridpointers' are identifier nodes for the reserved
 475    type names and storage classes.  It is indexed by a RID_... value.  */
 476 tree *ridpointers;
 477
 478 tree (*make_fname_decl) (tree, int);
 479
 480 /* Nonzero means the expression being parsed will never be evaluated.
 481    This is a count, since unevaluated expressions can nest.  */
 482 int skip_evaluation;
 483
 484 /* Information about how a function name is generated.  */
 485 struct fname_var_t
 486 {
 487   tree *const decl;     /* pointer to the VAR_DECL.  */
 488   const unsigned rid;   /* RID number for the identifier.  */
 489   const int pretty;     /* How pretty is it? */
 490 };
 491
 492 /* The three ways of getting then name of the current function.  */
 493
 494 const struct fname_var_t fname_vars[] =
 495 {
 496   /* C99 compliant __func__, must be first.  */
 497   {&c99_function_name_decl_node, RID_C99_FUNCTION_NAME, 0},
 498   /* GCC __FUNCTION__ compliant.  */
 499   {&function_name_decl_node, RID_FUNCTION_NAME, 0},
 500   /* GCC __PRETTY_FUNCTION__ compliant.  */
 501   {&pretty_function_name_decl_node, RID_PRETTY_FUNCTION_NAME, 1},
 502   {NULL, 0, 0},
 503 };
 504
 505 static int constant_fits_type_p (tree, tree);
 506 static tree check_case_value (tree);
 507 static bool check_case_bounds (tree, tree, tree *, tree *);
 508
 509 static tree handle_packed_attribute (tree *, tree, tree, int, bool *);
 510 static tree handle_nocommon_attribute (tree *, tree, tree, int, bool *);
 511 static tree handle_common_attribute (tree *, tree, tree, int, bool *);
 512 static tree handle_noreturn_attribute (tree *, tree, tree, int, bool *);
 513 static tree handle_noinline_attribute (tree *, tree, tree, int, bool *);
 514 static tree handle_always_inline_attribute (tree *, tree, tree, int,
 515                                             bool *);
 516 static tree handle_used_attribute (tree *, tree, tree, int, bool *);
 517 static tree handle_unused_attribute (tree *, tree, tree, int, bool *);
 518 static tree handle_externally_visible_attribute (tree *, tree, tree, int,
 519                                                  bool *);
 520 static tree handle_const_attribute (tree *, tree, tree, int, bool *);
 521 static tree handle_transparent_union_attribute (tree *, tree, tree,
 522                                                 int, bool *);
 523 static tree handle_constructor_attribute (tree *, tree, tree, int, bool *);
 524 static tree handle_destructor_attribute (tree *, tree, tree, int, bool *);
 525 static tree handle_mode_attribute (tree *, tree, tree, int, bool *);
 526 static tree handle_section_attribute (tree *, tree, tree, int, bool *);
 527 static tree handle_aligned_attribute (tree *, tree, tree, int, bool *);
 528 static tree handle_weak_attribute (tree *, tree, tree, int, bool *) ;
 529 static tree handle_alias_attribute (tree *, tree, tree, int, bool *);
 530 static tree handle_visibility_attribute (tree *, tree, tree, int,
 531                                          bool *);
 532 static tree handle_tls_model_attribute (tree *, tree, tree, int,
 533                                         bool *);
 534 static tree handle_no_instrument_function_attribute (tree *, tree,
 535                                                      tree, int, bool *);
 536 static tree handle_malloc_attribute (tree *, tree, tree, int, bool *);
 537 static tree handle_returns_twice_attribute (tree *, tree, tree, int, bool *);
 538 static tree handle_no_limit_stack_attribute (tree *, tree, tree, int,
 539                                              bool *);
 540 static tree handle_pure_attribute (tree *, tree, tree, int, bool *);
 541 static tree handle_novops_attribute (tree *, tree, tree, int, bool *);
 542 static tree handle_deprecated_attribute (tree *, tree, tree, int,
 543                                          bool *);
 544 static tree handle_vector_size_attribute (tree *, tree, tree, int,
 545                                           bool *);
 546 static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *);
 547 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
 548 static tree handle_cleanup_attribute (tree *, tree, tree, int, bool *);
 549 static tree handle_warn_unused_result_attribute (tree *, tree, tree, int,
 550                                                  bool *);
 551 static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *);
 552
 553 static void check_function_nonnull (tree, tree);
 554 static void check_nonnull_arg (void *, tree, unsigned HOST_WIDE_INT);
 555 static bool nonnull_check_p (tree, unsigned HOST_WIDE_INT);
 556 static bool get_nonnull_operand (tree, unsigned HOST_WIDE_INT *);
 557 static int resort_field_decl_cmp (const void *, const void *);
 558
 559 /* Table of machine-independent attributes common to all C-like languages.  */
 560 const struct attribute_spec c_common_attribute_table[] =
 561 {
 562   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 563   { "packed",                 0, 0, false, false, false,
 564                               handle_packed_attribute },
 565   { "nocommon",               0, 0, true,  false, false,
 566                               handle_nocommon_attribute },
 567   { "common",                 0, 0, true,  false, false,
 568                               handle_common_attribute },
 569   /* FIXME: logically, noreturn attributes should be listed as
 570      "false, true, true" and apply to function types.  But implementing this
 571      would require all the places in the compiler that use TREE_THIS_VOLATILE
 572      on a decl to identify non-returning functions to be located and fixed
 573      to check the function type instead.  */
 574   { "noreturn",               0, 0, true,  false, false,
 575                               handle_noreturn_attribute },
 576   { "volatile",               0, 0, true,  false, false,
 577                               handle_noreturn_attribute },
 578   { "noinline",               0, 0, true,  false, false,
 579                               handle_noinline_attribute },
 580   { "always_inline",          0, 0, true,  false, false,
 581                               handle_always_inline_attribute },
 582   { "used",                   0, 0, true,  false, false,
 583                               handle_used_attribute },
 584   { "unused",                 0, 0, false, false, false,
 585                               handle_unused_attribute },
 586   { "externally_visible",     0, 0, true,  false, false,
 587                               handle_externally_visible_attribute },
 588   /* The same comments as for noreturn attributes apply to const ones.  */
 589   { "const",                  0, 0, true,  false, false,
 590                               handle_const_attribute },
 591   { "transparent_union",      0, 0, false, false, false,
 592                               handle_transparent_union_attribute },
 593   { "constructor",            0, 0, true,  false, false,
 594                               handle_constructor_attribute },
 595   { "destructor",             0, 0, true,  false, false,
 596                               handle_destructor_attribute },
 597   { "mode",                   1, 1, false,  true, false,
 598                               handle_mode_attribute },
 599   { "section",                1, 1, true,  false, false,
 600                               handle_section_attribute },
 601   { "aligned",                0, 1, false, false, false,
 602                               handle_aligned_attribute },
 603   { "weak",                   0, 0, true,  false, false,
 604                               handle_weak_attribute },
 605   { "alias",                  1, 1, true,  false, false,
 606                               handle_alias_attribute },
 607   { "no_instrument_function", 0, 0, true,  false, false,
 608                               handle_no_instrument_function_attribute },
 609   { "malloc",                 0, 0, true,  false, false,
 610                               handle_malloc_attribute },
 611   { "returns_twice",          0, 0, true,  false, false,
 612                               handle_returns_twice_attribute },
 613   { "no_stack_limit",         0, 0, true,  false, false,
 614                               handle_no_limit_stack_attribute },
 615   { "pure",                   0, 0, true,  false, false,
 616                               handle_pure_attribute },
 617   /* For internal use (marking of builtins) only.  The name contains space
 618      to prevent its usage in source code.  */
 619   { "no vops",                0, 0, true,  false, false,
 620                               handle_novops_attribute },
 621   { "deprecated",             0, 0, false, false, false,
 622                               handle_deprecated_attribute },
 623   { "vector_size",            1, 1, false, true, false,
 624                               handle_vector_size_attribute },
 625   { "visibility",             1, 1, false, false, false,
 626                               handle_visibility_attribute },
 627   { "tls_model",              1, 1, true,  false, false,
 628                               handle_tls_model_attribute },
 629   { "nonnull",                0, -1, false, true, true,
 630                               handle_nonnull_attribute },
 631   { "nothrow",                0, 0, true,  false, false,
 632                               handle_nothrow_attribute },
 633   { "may_alias",              0, 0, false, true, false, NULL },
 634   { "cleanup",                1, 1, true, false, false,
 635                               handle_cleanup_attribute },
 636   { "warn_unused_result",     0, 0, false, true, true,
 637                               handle_warn_unused_result_attribute },
 638   { "sentinel",               0, 1, false, true, true,
 639                               handle_sentinel_attribute },
 640   { NULL,                     0, 0, false, false, false, NULL }
 641 };
 642
 643 /* Give the specifications for the format attributes, used by C and all
 644    descendants.  */
 645
 646 const struct attribute_spec c_common_format_attribute_table[] =
 647 {
 648   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 649   { "format",                 3, 3, false, true,  true,
 650                               handle_format_attribute },
 651   { "format_arg",             1, 1, false, true,  true,
 652                               handle_format_arg_attribute },
 653   { NULL,                     0, 0, false, false, false, NULL }
 654 };
 655
 656 /* Push current bindings for the function name VAR_DECLS.  */
 657
 658 void
 659 start_fname_decls (void)
 660 {
 661   unsigned ix;
 662   tree saved = NULL_TREE;
 663
 664   for (ix = 0; fname_vars[ix].decl; ix++)
 665     {
 666       tree decl = *fname_vars[ix].decl;
 667
 668       if (decl)
 669         {
 670           saved = tree_cons (decl, build_int_cst (NULL_TREE, ix), saved);
 671           *fname_vars[ix].decl = NULL_TREE;
 672         }
 673     }
 674   if (saved || saved_function_name_decls)
 675     /* Normally they'll have been NULL, so only push if we've got a
 676        stack, or they are non-NULL.  */
 677     saved_function_name_decls = tree_cons (saved, NULL_TREE,
 678                                            saved_function_name_decls);
 679 }
 680
 681 /* Finish up the current bindings, adding them into the current function's
 682    statement tree.  This must be done _before_ finish_stmt_tree is called.
 683    If there is no current function, we must be at file scope and no statements
 684    are involved. Pop the previous bindings.  */
 685
 686 void
 687 finish_fname_decls (void)
 688 {
 689   unsigned ix;
 690   tree stmts = NULL_TREE;
 691   tree stack = saved_function_name_decls;
 692
 693   for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack))
 694     append_to_statement_list (TREE_VALUE (stack), &stmts);
 695
 696   if (stmts)
 697     {
 698       tree *bodyp = &DECL_SAVED_TREE (current_function_decl);
 699
 700       if (TREE_CODE (*bodyp) == BIND_EXPR)
 701         bodyp = &BIND_EXPR_BODY (*bodyp);
 702
 703       append_to_statement_list (*bodyp, &stmts);
 704       *bodyp = stmts;
 705     }
 706
 707   for (ix = 0; fname_vars[ix].decl; ix++)
 708     *fname_vars[ix].decl = NULL_TREE;
 709
 710   if (stack)
 711     {
 712       /* We had saved values, restore them.  */
 713       tree saved;
 714
 715       for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved))
 716         {
 717           tree decl = TREE_PURPOSE (saved);
 718           unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved));
 719
 720           *fname_vars[ix].decl = decl;
 721         }
 722       stack = TREE_CHAIN (stack);
 723     }
 724   saved_function_name_decls = stack;
 725 }
 726
 727 /* Return the text name of the current function, suitably prettified
 728    by PRETTY_P.  Return string must be freed by caller.  */
 729
 730 const char *
 731 fname_as_string (int pretty_p)
 732 {
 733   const char *name = "top level";
 734   char *namep;
 735   int vrb = 2;
 736
 737   if (!pretty_p)
 738     {
 739       name = "";
 740       vrb = 0;
 741     }
 742
 743   if (current_function_decl)
 744     name = lang_hooks.decl_printable_name (current_function_decl, vrb);
 745
 746   if (c_lex_string_translate)
 747     {
 748       int len = strlen (name) + 3; /* Two for '"'s.  One for NULL.  */
 749       cpp_string cstr = { 0, 0 }, strname;
 750
 751       namep = XNEWVEC (char, len);
 752       snprintf (namep, len, "\"%s\"", name);
 753       strname.text = (unsigned char *) namep;
 754       strname.len = len - 1;
 755
 756       if (cpp_interpret_string (parse_in, &strname, 1, &cstr, false))
 757         {
 758           XDELETEVEC (namep);
 759           return (char *) cstr.text;
 760         }
 761     }
 762   else
 763     namep = xstrdup (name);
 764
 765   return namep;
 766 }
 767
 768 /* Expand DECL if it declares an entity not handled by the
 769    common code.  */
 770
 771 int
 772 c_expand_decl (tree decl)
 773 {
 774   if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl))
 775     {
 776       /* Let the back-end know about this variable.  */
 777       if (!anon_aggr_type_p (TREE_TYPE (decl)))
 778         emit_local_var (decl);
 779       else
 780         expand_anon_union_decl (decl, NULL_TREE,
 781                                 DECL_ANON_UNION_ELEMS (decl));
 782     }
 783   else
 784     return 0;
 785
 786   return 1;
 787 }
 788
 789
 790 /* Return the VAR_DECL for a const char array naming the current
 791    function. If the VAR_DECL has not yet been created, create it
 792    now. RID indicates how it should be formatted and IDENTIFIER_NODE
 793    ID is its name (unfortunately C and C++ hold the RID values of
 794    keywords in different places, so we can't derive RID from ID in
 795    this language independent code.  */
 796
 797 tree
 798 fname_decl (unsigned int rid, tree id)
 799 {
 800   unsigned ix;
 801   tree decl = NULL_TREE;
 802
 803   for (ix = 0; fname_vars[ix].decl; ix++)
 804     if (fname_vars[ix].rid == rid)
 805       break;
 806
 807   decl = *fname_vars[ix].decl;
 808   if (!decl)
 809     {
 810       /* If a tree is built here, it would normally have the lineno of
 811          the current statement.  Later this tree will be moved to the
 812          beginning of the function and this line number will be wrong.
 813          To avoid this problem set the lineno to 0 here; that prevents
 814          it from appearing in the RTL.  */
 815       tree stmts;
 816       location_t saved_location = input_location;
 817 #ifdef USE_MAPPED_LOCATION
 818       input_location = UNKNOWN_LOCATION;
 819 #else
 820       input_line = 0;
 821 #endif
 822
 823       stmts = push_stmt_list ();
 824       decl = (*make_fname_decl) (id, fname_vars[ix].pretty);
 825       stmts = pop_stmt_list (stmts);
 826       if (!IS_EMPTY_STMT (stmts))
 827         saved_function_name_decls
 828           = tree_cons (decl, stmts, saved_function_name_decls);
 829       *fname_vars[ix].decl = decl;
 830       input_location = saved_location;
 831     }
 832   if (!ix && !current_function_decl)
 833     pedwarn ("%qD is not defined outside of function scope", decl);
 834
 835   return decl;
 836 }
 837
 838 /* Given a STRING_CST, give it a suitable array-of-chars data type.  */
 839
 840 tree
 841 fix_string_type (tree value)
 842 {
 843   const int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
 844   const int wide_flag = TREE_TYPE (value) == wchar_array_type_node;
 845   const int nchars_max = flag_isoc99 ? 4095 : 509;
 846   int length = TREE_STRING_LENGTH (value);
 847   int nchars;
 848   tree e_type, i_type, a_type;
 849
 850   /* Compute the number of elements, for the array type.  */
 851   nchars = wide_flag ? length / wchar_bytes : length;
 852
 853   if (pedantic && nchars - 1 > nchars_max && !c_dialect_cxx ())
 854     pedwarn ("string length %qd is greater than the length %qd ISO C%d compilers are required to support",
 855              nchars - 1, nchars_max, flag_isoc99 ? 99 : 89);
 856
 857   e_type = wide_flag ? wchar_type_node : char_type_node;
 858   /* Create the array type for the string constant.  flag_const_strings
 859      says make the string constant an array of const char so that
 860      copying it to a non-const pointer will get a warning.  For C++,
 861      this is the standard behavior.
 862
 863      The C++ front end relies on TYPE_MAIN_VARIANT of a cv-qualified
 864      array type being the unqualified version of that type.
 865      Therefore, if we are constructing an array of const char, we must
 866      construct the matching unqualified array type first.  The C front
 867      end does not require this, but it does no harm, so we do it
 868      unconditionally.  */
 869   i_type = build_index_type (build_int_cst (NULL_TREE, nchars - 1));
 870   a_type = build_array_type (e_type, i_type);
 871   if (flag_const_strings)
 872     a_type = c_build_qualified_type (a_type, TYPE_QUAL_CONST);
 873
 874   TREE_TYPE (value) = a_type;
 875   TREE_CONSTANT (value) = 1;
 876   TREE_INVARIANT (value) = 1;
 877   TREE_READONLY (value) = 1;
 878   TREE_STATIC (value) = 1;
 879   return value;
 880 }
 881 \f
 882 /* Print a warning if a constant expression had overflow in folding.
 883    Invoke this function on every expression that the language
 884    requires to be a constant expression.
 885    Note the ANSI C standard says it is erroneous for a
 886    constant expression to overflow.  */
 887
 888 void
 889 constant_expression_warning (tree value)
 890 {
 891   if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
 892        || TREE_CODE (value) == VECTOR_CST
 893        || TREE_CODE (value) == COMPLEX_CST)
 894       && TREE_CONSTANT_OVERFLOW (value) && pedantic)
 895     pedwarn ("overflow in constant expression");
 896 }
 897
 898 /* Print a warning if an expression had overflow in folding.
 899    Invoke this function on every expression that
 900    (1) appears in the source code, and
 901    (2) might be a constant expression that overflowed, and
 902    (3) is not already checked by convert_and_check;
 903    however, do not invoke this function on operands of explicit casts.  */
 904
 905 void
 906 overflow_warning (tree value)
 907 {
 908   if ((TREE_CODE (value) == INTEGER_CST
 909        || (TREE_CODE (value) == COMPLEX_CST
 910            && TREE_CODE (TREE_REALPART (value)) == INTEGER_CST))
 911       && TREE_OVERFLOW (value))
 912     {
 913       TREE_OVERFLOW (value) = 0;
 914       if (skip_evaluation == 0)
 915         warning (0, "integer overflow in expression");
 916     }
 917   else if ((TREE_CODE (value) == REAL_CST
 918             || (TREE_CODE (value) == COMPLEX_CST
 919                 && TREE_CODE (TREE_REALPART (value)) == REAL_CST))
 920            && TREE_OVERFLOW (value))
 921     {
 922       TREE_OVERFLOW (value) = 0;
 923       if (skip_evaluation == 0)
 924         warning (0, "floating point overflow in expression");
 925     }
 926   else if (TREE_CODE (value) == VECTOR_CST && TREE_OVERFLOW (value))
 927     {
 928       TREE_OVERFLOW (value) = 0;
 929       if (skip_evaluation == 0)
 930         warning (0, "vector overflow in expression");
 931     }
 932 }
 933
 934 /* Print a warning if a large constant is truncated to unsigned,
 935    or if -Wconversion is used and a constant < 0 is converted to unsigned.
 936    Invoke this function on every expression that might be implicitly
 937    converted to an unsigned type.  */
 938
 939 void
 940 unsigned_conversion_warning (tree result, tree operand)
 941 {
 942   tree type = TREE_TYPE (result);
 943
 944   if (TREE_CODE (operand) == INTEGER_CST
 945       && TREE_CODE (type) == INTEGER_TYPE
 946       && TYPE_UNSIGNED (type)
 947       && skip_evaluation == 0
 948       && !int_fits_type_p (operand, type))
 949     {
 950       if (!int_fits_type_p (operand, c_common_signed_type (type)))
 951         /* This detects cases like converting -129 or 256 to unsigned char.  */
 952         warning (0, "large integer implicitly truncated to unsigned type");
 953       else
 954         warning (OPT_Wconversion,
 955                  "negative integer implicitly converted to unsigned type");
 956     }
 957 }
 958
 959 /* Nonzero if constant C has a value that is permissible
 960    for type TYPE (an INTEGER_TYPE).  */
 961
 962 static int
 963 constant_fits_type_p (tree c, tree type)
 964 {
 965   if (TREE_CODE (c) == INTEGER_CST)
 966     return int_fits_type_p (c, type);
 967
 968   c = convert (type, c);
 969   return !TREE_OVERFLOW (c);
 970 }
 971
 972 /* Nonzero if vector types T1 and T2 can be converted to each other
 973    without an explicit cast.  */
 974 int
 975 vector_types_convertible_p (tree t1, tree t2)
 976 {
 977   return targetm.vector_opaque_p (t1)
 978          || targetm.vector_opaque_p (t2)
 979          || (tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2))
 980              && INTEGRAL_TYPE_P (TREE_TYPE (t1))
 981                 == INTEGRAL_TYPE_P (TREE_TYPE (t2)));
 982 }
 983
 984 /* Convert EXPR to TYPE, warning about conversion problems with constants.
 985    Invoke this function on every expression that is converted implicitly,
 986    i.e. because of language rules and not because of an explicit cast.  */
 987
 988 tree
 989 convert_and_check (tree type, tree expr)
 990 {
 991   tree t = convert (type, expr);
 992   if (TREE_CODE (t) == INTEGER_CST)
 993     {
 994       if (TREE_OVERFLOW (t))
 995         {
 996           TREE_OVERFLOW (t) = 0;
 997
 998           /* Do not diagnose overflow in a constant expression merely
 999              because a conversion overflowed.  */
1000           TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (expr);
1001
1002           /* No warning for converting 0x80000000 to int.  */
1003           if (!(TYPE_UNSIGNED (type) < TYPE_UNSIGNED (TREE_TYPE (expr))
1004                 && TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
1005                 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (expr))))
1006             /* If EXPR fits in the unsigned version of TYPE,
1007                don't warn unless pedantic.  */
1008             if ((pedantic
1009                  || TYPE_UNSIGNED (type)
1010                  || !constant_fits_type_p (expr,
1011                                            c_common_unsigned_type (type)))
1012                 && skip_evaluation == 0)
1013               warning (0, "overflow in implicit constant conversion");
1014         }
1015       else
1016         unsigned_conversion_warning (t, expr);
1017     }
1018   return t;
1019 }
1020 \f
1021 /* A node in a list that describes references to variables (EXPR), which are
1022    either read accesses if WRITER is zero, or write accesses, in which case
1023    WRITER is the parent of EXPR.  */
1024 struct tlist
1025 {
1026   struct tlist *next;
1027   tree expr, writer;
1028 };
1029
1030 /* Used to implement a cache the results of a call to verify_tree.  We only
1031    use this for SAVE_EXPRs.  */
1032 struct tlist_cache
1033 {
1034   struct tlist_cache *next;
1035   struct tlist *cache_before_sp;
1036   struct tlist *cache_after_sp;
1037   tree expr;
1038 };
1039
1040 /* Obstack to use when allocating tlist structures, and corresponding
1041    firstobj.  */
1042 static struct obstack tlist_obstack;
1043 static char *tlist_firstobj = 0;
1044
1045 /* Keep track of the identifiers we've warned about, so we can avoid duplicate
1046    warnings.  */
1047 static struct tlist *warned_ids;
1048 /* SAVE_EXPRs need special treatment.  We process them only once and then
1049    cache the results.  */
1050 static struct tlist_cache *save_expr_cache;
1051
1052 static void add_tlist (struct tlist **, struct tlist *, tree, int);
1053 static void merge_tlist (struct tlist **, struct tlist *, int);
1054 static void verify_tree (tree, struct tlist **, struct tlist **, tree);
1055 static int warning_candidate_p (tree);
1056 static void warn_for_collisions (struct tlist *);
1057 static void warn_for_collisions_1 (tree, tree, struct tlist *, int);
1058 static struct tlist *new_tlist (struct tlist *, tree, tree);
1059
1060 /* Create a new struct tlist and fill in its fields.  */
1061 static struct tlist *
1062 new_tlist (struct tlist *next, tree t, tree writer)
1063 {
1064   struct tlist *l;
1065   l = XOBNEW (&tlist_obstack, struct tlist);
1066   l->next = next;
1067   l->expr = t;
1068   l->writer = writer;
1069   return l;
1070 }
1071
1072 /* Add duplicates of the nodes found in ADD to the list *TO.  If EXCLUDE_WRITER
1073    is nonnull, we ignore any node we find which has a writer equal to it.  */
1074
1075 static void
1076 add_tlist (struct tlist **to, struct tlist *add, tree exclude_writer, int copy)
1077 {
1078   while (add)
1079     {
1080       struct tlist *next = add->next;
1081       if (!copy)
1082         add->next = *to;
1083       if (!exclude_writer || add->writer != exclude_writer)
1084         *to = copy ? new_tlist (*to, add->expr, add->writer) : add;
1085       add = next;
1086     }
1087 }
1088
1089 /* Merge the nodes of ADD into TO.  This merging process is done so that for
1090    each variable that already exists in TO, no new node is added; however if
1091    there is a write access recorded in ADD, and an occurrence on TO is only
1092    a read access, then the occurrence in TO will be modified to record the
1093    write.  */
1094
1095 static void
1096 merge_tlist (struct tlist **to, struct tlist *add, int copy)
1097 {
1098   struct tlist **end = to;
1099
1100   while (*end)
1101     end = &(*end)->next;
1102
1103   while (add)
1104     {
1105       int found = 0;
1106       struct tlist *tmp2;
1107       struct tlist *next = add->next;
1108
1109       for (tmp2 = *to; tmp2; tmp2 = tmp2->next)
1110         if (tmp2->expr == add->expr)
1111           {
1112             found = 1;
1113             if (!tmp2->writer)
1114               tmp2->writer = add->writer;
1115           }
1116       if (!found)
1117         {
1118           *end = copy ? add : new_tlist (NULL, add->expr, add->writer);
1119           end = &(*end)->next;
1120           *end = 0;
1121         }
1122       add = next;
1123     }
1124 }
1125
1126 /* WRITTEN is a variable, WRITER is its parent.  Warn if any of the variable
1127    references in list LIST conflict with it, excluding reads if ONLY writers
1128    is nonzero.  */
1129
1130 static void
1131 warn_for_collisions_1 (tree written, tree writer, struct tlist *list,
1132                        int only_writes)
1133 {
1134   struct tlist *tmp;
1135
1136   /* Avoid duplicate warnings.  */
1137   for (tmp = warned_ids; tmp; tmp = tmp->next)
1138     if (tmp->expr == written)
1139       return;
1140
1141   while (list)
1142     {
1143       if (list->expr == written
1144           && list->writer != writer
1145           && (!only_writes || list->writer)
1146           && DECL_NAME (list->expr))
1147         {
1148           warned_ids = new_tlist (warned_ids, written, NULL_TREE);
1149           warning (0, "operation on %qE may be undefined", list->expr);
1150         }
1151       list = list->next;
1152     }
1153 }
1154
1155 /* Given a list LIST of references to variables, find whether any of these
1156    can cause conflicts due to missing sequence points.  */
1157
1158 static void
1159 warn_for_collisions (struct tlist *list)
1160 {
1161   struct tlist *tmp;
1162
1163   for (tmp = list; tmp; tmp = tmp->next)
1164     {
1165       if (tmp->writer)
1166         warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0);
1167     }
1168 }
1169
1170 /* Return nonzero if X is a tree that can be verified by the sequence point
1171    warnings.  */
1172 static int
1173 warning_candidate_p (tree x)
1174 {
1175   return TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == PARM_DECL;
1176 }
1177
1178 /* Walk the tree X, and record accesses to variables.  If X is written by the
1179    parent tree, WRITER is the parent.
1180    We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP.  If this
1181    expression or its only operand forces a sequence point, then everything up
1182    to the sequence point is stored in PBEFORE_SP.  Everything else gets stored
1183    in PNO_SP.
1184    Once we return, we will have emitted warnings if any subexpression before
1185    such a sequence point could be undefined.  On a higher level, however, the
1186    sequence point may not be relevant, and we'll merge the two lists.
1187
1188    Example: (b++, a) + b;
1189    The call that processes the COMPOUND_EXPR will store the increment of B
1190    in PBEFORE_SP, and the use of A in PNO_SP.  The higher-level call that
1191    processes the PLUS_EXPR will need to merge the two lists so that
1192    eventually, all accesses end up on the same list (and we'll warn about the
1193    unordered subexpressions b++ and b.
1194
1195    A note on merging.  If we modify the former example so that our expression
1196    becomes
1197      (b++, b) + a
1198    care must be taken not simply to add all three expressions into the final
1199    PNO_SP list.  The function merge_tlist takes care of that by merging the
1200    before-SP list of the COMPOUND_EXPR into its after-SP list in a special
1201    way, so that no more than one access to B is recorded.  */
1202
1203 static void
1204 verify_tree (tree x, struct tlist **pbefore_sp, struct tlist **pno_sp,
1205              tree writer)
1206 {
1207   struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3;
1208   enum tree_code code;
1209   enum tree_code_class cl;
1210
1211   /* X may be NULL if it is the operand of an empty statement expression
1212      ({ }).  */
1213   if (x == NULL)
1214     return;
1215
1216  restart:
1217   code = TREE_CODE (x);
1218   cl = TREE_CODE_CLASS (code);
1219
1220   if (warning_candidate_p (x))
1221     {
1222       *pno_sp = new_tlist (*pno_sp, x, writer);
1223       return;
1224     }
1225
1226   switch (code)
1227     {
1228     case CONSTRUCTOR:
1229       return;
1230
1231     case COMPOUND_EXPR:
1232     case TRUTH_ANDIF_EXPR:
1233     case TRUTH_ORIF_EXPR:
1234       tmp_before = tmp_nosp = tmp_list3 = 0;
1235       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1236       warn_for_collisions (tmp_nosp);
1237       merge_tlist (pbefore_sp, tmp_before, 0);
1238       merge_tlist (pbefore_sp, tmp_nosp, 0);
1239       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE);
1240       merge_tlist (pbefore_sp, tmp_list3, 0);
1241       return;
1242
1243     case COND_EXPR:
1244       tmp_before = tmp_list2 = 0;
1245       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE);
1246       warn_for_collisions (tmp_list2);
1247       merge_tlist (pbefore_sp, tmp_before, 0);
1248       merge_tlist (pbefore_sp, tmp_list2, 1);
1249
1250       tmp_list3 = tmp_nosp = 0;
1251       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE);
1252       warn_for_collisions (tmp_nosp);
1253       merge_tlist (pbefore_sp, tmp_list3, 0);
1254
1255       tmp_list3 = tmp_list2 = 0;
1256       verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE);
1257       warn_for_collisions (tmp_list2);
1258       merge_tlist (pbefore_sp, tmp_list3, 0);
1259       /* Rather than add both tmp_nosp and tmp_list2, we have to merge the
1260          two first, to avoid warning for (a ? b++ : b++).  */
1261       merge_tlist (&tmp_nosp, tmp_list2, 0);
1262       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1263       return;
1264
1265     case PREDECREMENT_EXPR:
1266     case PREINCREMENT_EXPR:
1267     case POSTDECREMENT_EXPR:
1268     case POSTINCREMENT_EXPR:
1269       verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x);
1270       return;
1271
1272     case MODIFY_EXPR:
1273       tmp_before = tmp_nosp = tmp_list3 = 0;
1274       verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE);
1275       verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x);
1276       /* Expressions inside the LHS are not ordered wrt. the sequence points
1277          in the RHS.  Example:
1278            *a = (a++, 2)
1279          Despite the fact that the modification of "a" is in the before_sp
1280          list (tmp_before), it conflicts with the use of "a" in the LHS.
1281          We can handle this by adding the contents of tmp_list3
1282          to those of tmp_before, and redoing the collision warnings for that
1283          list.  */
1284       add_tlist (&tmp_before, tmp_list3, x, 1);
1285       warn_for_collisions (tmp_before);
1286       /* Exclude the LHS itself here; we first have to merge it into the
1287          tmp_nosp list.  This is done to avoid warning for "a = a"; if we
1288          didn't exclude the LHS, we'd get it twice, once as a read and once
1289          as a write.  */
1290       add_tlist (pno_sp, tmp_list3, x, 0);
1291       warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1);
1292
1293       merge_tlist (pbefore_sp, tmp_before, 0);
1294       if (warning_candidate_p (TREE_OPERAND (x, 0)))
1295         merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0);
1296       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1);
1297       return;
1298
1299     case CALL_EXPR:
1300       /* We need to warn about conflicts among arguments and conflicts between
1301          args and the function address.  Side effects of the function address,
1302          however, are not ordered by the sequence point of the call.  */
1303       tmp_before = tmp_nosp = tmp_list2 = tmp_list3 = 0;
1304       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1305       if (TREE_OPERAND (x, 1))
1306         verify_tree (TREE_OPERAND (x, 1), &tmp_list2, &tmp_list3, NULL_TREE);
1307       merge_tlist (&tmp_list3, tmp_list2, 0);
1308       add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0);
1309       add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0);
1310       warn_for_collisions (tmp_before);
1311       add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0);
1312       return;
1313
1314     case TREE_LIST:
1315       /* Scan all the list, e.g. indices of multi dimensional array.  */
1316       while (x)
1317         {
1318           tmp_before = tmp_nosp = 0;
1319           verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE);
1320           merge_tlist (&tmp_nosp, tmp_before, 0);
1321           add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1322           x = TREE_CHAIN (x);
1323         }
1324       return;
1325
1326     case SAVE_EXPR:
1327       {
1328         struct tlist_cache *t;
1329         for (t = save_expr_cache; t; t = t->next)
1330           if (t->expr == x)
1331             break;
1332
1333         if (!t)
1334           {
1335             t = XOBNEW (&tlist_obstack, struct tlist_cache);
1336             t->next = save_expr_cache;
1337             t->expr = x;
1338             save_expr_cache = t;
1339
1340             tmp_before = tmp_nosp = 0;
1341             verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1342             warn_for_collisions (tmp_nosp);
1343
1344             tmp_list3 = 0;
1345             while (tmp_nosp)
1346               {
1347                 struct tlist *t = tmp_nosp;
1348                 tmp_nosp = t->next;
1349                 merge_tlist (&tmp_list3, t, 0);
1350               }
1351             t->cache_before_sp = tmp_before;
1352             t->cache_after_sp = tmp_list3;
1353           }
1354         merge_tlist (pbefore_sp, t->cache_before_sp, 1);
1355         add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1);
1356         return;
1357       }
1358
1359     default:
1360       /* For other expressions, simply recurse on their operands.
1361          Manual tail recursion for unary expressions.
1362          Other non-expressions need not be processed.  */
1363       if (cl == tcc_unary)
1364         {
1365           x = TREE_OPERAND (x, 0);
1366           writer = 0;
1367           goto restart;
1368         }
1369       else if (IS_EXPR_CODE_CLASS (cl))
1370         {
1371           int lp;
1372           int max = TREE_CODE_LENGTH (TREE_CODE (x));
1373           for (lp = 0; lp < max; lp++)
1374             {
1375               tmp_before = tmp_nosp = 0;
1376               verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, 0);
1377               merge_tlist (&tmp_nosp, tmp_before, 0);
1378               add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1379             }
1380         }
1381       return;
1382     }
1383 }
1384
1385 /* Try to warn for undefined behavior in EXPR due to missing sequence
1386    points.  */
1387
1388 void
1389 verify_sequence_points (tree expr)
1390 {
1391   struct tlist *before_sp = 0, *after_sp = 0;
1392
1393   warned_ids = 0;
1394   save_expr_cache = 0;
1395   if (tlist_firstobj == 0)
1396     {
1397       gcc_obstack_init (&tlist_obstack);
1398       tlist_firstobj = (char *) obstack_alloc (&tlist_obstack, 0);
1399     }
1400
1401   verify_tree (expr, &before_sp, &after_sp, 0);
1402   warn_for_collisions (after_sp);
1403   obstack_free (&tlist_obstack, tlist_firstobj);
1404 }
1405 \f
1406 /* Validate the expression after `case' and apply default promotions.  */
1407
1408 static tree
1409 check_case_value (tree value)
1410 {
1411   if (value == NULL_TREE)
1412     return value;
1413
1414   /* ??? Can we ever get nops here for a valid case value?  We
1415      shouldn't for C.  */
1416   STRIP_TYPE_NOPS (value);
1417   /* In C++, the following is allowed:
1418
1419        const int i = 3;
1420        switch (...) { case i: ... }
1421
1422      So, we try to reduce the VALUE to a constant that way.  */
1423   if (c_dialect_cxx ())
1424     {
1425       value = decl_constant_value (value);
1426       STRIP_TYPE_NOPS (value);
1427       value = fold (value);
1428     }
1429
1430   if (TREE_CODE (value) == INTEGER_CST)
1431     /* Promote char or short to int.  */
1432     value = perform_integral_promotions (value);
1433   else if (value != error_mark_node)
1434     {
1435       error ("case label does not reduce to an integer constant");
1436       value = error_mark_node;
1437     }
1438
1439   constant_expression_warning (value);
1440
1441   return value;
1442 }
1443 \f
1444 /* See if the case values LOW and HIGH are in the range of the original
1445    type (i.e. before the default conversion to int) of the switch testing
1446    expression.
1447    TYPE is the promoted type of the testing expression, and ORIG_TYPE is
1448    the type before promoting it.  CASE_LOW_P is a pointer to the lower
1449    bound of the case label, and CASE_HIGH_P is the upper bound or NULL
1450    if the case is not a case range.
1451    The caller has to make sure that we are not called with NULL for
1452    CASE_LOW_P (i.e. the default case).
1453    Returns true if the case label is in range of ORIG_TYPE (saturated or
1454    untouched) or false if the label is out of range.  */
1455
1456 static bool
1457 check_case_bounds (tree type, tree orig_type,
1458                    tree *case_low_p, tree *case_high_p)
1459 {
1460   tree min_value, max_value;
1461   tree case_low = *case_low_p;
1462   tree case_high = case_high_p ? *case_high_p : case_low;
1463
1464   /* If there was a problem with the original type, do nothing.  */
1465   if (orig_type == error_mark_node)
1466     return true;
1467
1468   min_value = TYPE_MIN_VALUE (orig_type);
1469   max_value = TYPE_MAX_VALUE (orig_type);
1470
1471   /* Case label is less than minimum for type.  */
1472   if (tree_int_cst_compare (case_low, min_value) < 0
1473       && tree_int_cst_compare (case_high, min_value) < 0)
1474     {
1475       warning (0, "case label value is less than minimum value for type");
1476       return false;
1477     }
1478
1479   /* Case value is greater than maximum for type.  */
1480   if (tree_int_cst_compare (case_low, max_value) > 0
1481       && tree_int_cst_compare (case_high, max_value) > 0)
1482     {
1483       warning (0, "case label value exceeds maximum value for type");
1484       return false;
1485     }
1486
1487   /* Saturate lower case label value to minimum.  */
1488   if (tree_int_cst_compare (case_high, min_value) >= 0
1489       && tree_int_cst_compare (case_low, min_value) < 0)
1490     {
1491       warning (0, "lower value in case label range"
1492                " less than minimum value for type");
1493       case_low = min_value;
1494     }
1495
1496   /* Saturate upper case label value to maximum.  */
1497   if (tree_int_cst_compare (case_low, max_value) <= 0
1498       && tree_int_cst_compare (case_high, max_value) > 0)
1499     {
1500       warning (0, "upper value in case label range"
1501                " exceeds maximum value for type");
1502       case_high = max_value;
1503     }
1504
1505   if (*case_low_p != case_low)
1506     *case_low_p = convert (type, case_low);
1507   if (case_high_p && *case_high_p != case_high)
1508     *case_high_p = convert (type, case_high);
1509
1510   return true;
1511 }
1512 \f
1513 /* Return an integer type with BITS bits of precision,
1514    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
1515
1516 tree
1517 c_common_type_for_size (unsigned int bits, int unsignedp)
1518 {
1519   if (bits == TYPE_PRECISION (integer_type_node))
1520     return unsignedp ? unsigned_type_node : integer_type_node;
1521
1522   if (bits == TYPE_PRECISION (signed_char_type_node))
1523     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1524
1525   if (bits == TYPE_PRECISION (short_integer_type_node))
1526     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1527
1528   if (bits == TYPE_PRECISION (long_integer_type_node))
1529     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1530
1531   if (bits == TYPE_PRECISION (long_long_integer_type_node))
1532     return (unsignedp ? long_long_unsigned_type_node
1533             : long_long_integer_type_node);
1534
1535   if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
1536     return (unsignedp ? widest_unsigned_literal_type_node
1537             : widest_integer_literal_type_node);
1538
1539   if (bits <= TYPE_PRECISION (intQI_type_node))
1540     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1541
1542   if (bits <= TYPE_PRECISION (intHI_type_node))
1543     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1544
1545   if (bits <= TYPE_PRECISION (intSI_type_node))
1546     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1547
1548   if (bits <= TYPE_PRECISION (intDI_type_node))
1549     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1550
1551   return 0;
1552 }
1553
1554 /* Used for communication between c_common_type_for_mode and
1555    c_register_builtin_type.  */
1556 static GTY(()) tree registered_builtin_types;
1557
1558 /* Return a data type that has machine mode MODE.
1559    If the mode is an integer,
1560    then UNSIGNEDP selects between signed and unsigned types.  */
1561
1562 tree
1563 c_common_type_for_mode (enum machine_mode mode, int unsignedp)
1564 {
1565   tree t;
1566
1567   if (mode == TYPE_MODE (integer_type_node))
1568     return unsignedp ? unsigned_type_node : integer_type_node;
1569
1570   if (mode == TYPE_MODE (signed_char_type_node))
1571     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1572
1573   if (mode == TYPE_MODE (short_integer_type_node))
1574     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1575
1576   if (mode == TYPE_MODE (long_integer_type_node))
1577     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1578
1579   if (mode == TYPE_MODE (long_long_integer_type_node))
1580     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
1581
1582   if (mode == TYPE_MODE (widest_integer_literal_type_node))
1583     return unsignedp ? widest_unsigned_literal_type_node
1584                      : widest_integer_literal_type_node;
1585
1586   if (mode == QImode)
1587     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1588
1589   if (mode == HImode)
1590     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1591
1592   if (mode == SImode)
1593     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1594
1595   if (mode == DImode)
1596     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1597
1598 #if HOST_BITS_PER_WIDE_INT >= 64
1599   if (mode == TYPE_MODE (intTI_type_node))
1600     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
1601 #endif
1602
1603   if (mode == TYPE_MODE (float_type_node))
1604     return float_type_node;
1605
1606   if (mode == TYPE_MODE (double_type_node))
1607     return double_type_node;
1608
1609   if (mode == TYPE_MODE (long_double_type_node))
1610     return long_double_type_node;
1611
1612   if (mode == TYPE_MODE (void_type_node))
1613     return void_type_node;
1614
1615   if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
1616     return (unsignedp
1617             ? make_unsigned_type (GET_MODE_PRECISION (mode))
1618             : make_signed_type (GET_MODE_PRECISION (mode)));
1619
1620   if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
1621     return (unsignedp
1622             ? make_unsigned_type (GET_MODE_PRECISION (mode))
1623             : make_signed_type (GET_MODE_PRECISION (mode)));
1624
1625   if (COMPLEX_MODE_P (mode))
1626     {
1627       enum machine_mode inner_mode;
1628       tree inner_type;
1629
1630       if (mode == TYPE_MODE (complex_float_type_node))
1631         return complex_float_type_node;
1632       if (mode == TYPE_MODE (complex_double_type_node))
1633         return complex_double_type_node;
1634       if (mode == TYPE_MODE (complex_long_double_type_node))
1635         return complex_long_double_type_node;
1636
1637       if (mode == TYPE_MODE (complex_integer_type_node) && !unsignedp)
1638         return complex_integer_type_node;
1639
1640       inner_mode = GET_MODE_INNER (mode);
1641       inner_type = c_common_type_for_mode (inner_mode, unsignedp);
1642       if (inner_type != NULL_TREE)
1643         return build_complex_type (inner_type);
1644     }
1645   else if (VECTOR_MODE_P (mode))
1646     {
1647       enum machine_mode inner_mode = GET_MODE_INNER (mode);
1648       tree inner_type = c_common_type_for_mode (inner_mode, unsignedp);
1649       if (inner_type != NULL_TREE)
1650         return build_vector_type_for_mode (inner_type, mode);
1651     }
1652
1653   for (t = registered_builtin_types; t; t = TREE_CHAIN (t))
1654     if (TYPE_MODE (TREE_VALUE (t)) == mode)
1655       return TREE_VALUE (t);
1656
1657   return 0;
1658 }
1659
1660 /* Return an unsigned type the same as TYPE in other respects.  */
1661 tree
1662 c_common_unsigned_type (tree type)
1663 {
1664   tree type1 = TYPE_MAIN_VARIANT (type);
1665   if (type1 == signed_char_type_node || type1 == char_type_node)
1666     return unsigned_char_type_node;
1667   if (type1 == integer_type_node)
1668     return unsigned_type_node;
1669   if (type1 == short_integer_type_node)
1670     return short_unsigned_type_node;
1671   if (type1 == long_integer_type_node)
1672     return long_unsigned_type_node;
1673   if (type1 == long_long_integer_type_node)
1674     return long_long_unsigned_type_node;
1675   if (type1 == widest_integer_literal_type_node)
1676     return widest_unsigned_literal_type_node;
1677 #if HOST_BITS_PER_WIDE_INT >= 64
1678   if (type1 == intTI_type_node)
1679     return unsigned_intTI_type_node;
1680 #endif
1681   if (type1 == intDI_type_node)
1682     return unsigned_intDI_type_node;
1683   if (type1 == intSI_type_node)
1684     return unsigned_intSI_type_node;
1685   if (type1 == intHI_type_node)
1686     return unsigned_intHI_type_node;
1687   if (type1 == intQI_type_node)
1688     return unsigned_intQI_type_node;
1689
1690   return c_common_signed_or_unsigned_type (1, type);
1691 }
1692
1693 /* Return a signed type the same as TYPE in other respects.  */
1694
1695 tree
1696 c_common_signed_type (tree type)
1697 {
1698   tree type1 = TYPE_MAIN_VARIANT (type);
1699   if (type1 == unsigned_char_type_node || type1 == char_type_node)
1700     return signed_char_type_node;
1701   if (type1 == unsigned_type_node)
1702     return integer_type_node;
1703   if (type1 == short_unsigned_type_node)
1704     return short_integer_type_node;
1705   if (type1 == long_unsigned_type_node)
1706     return long_integer_type_node;
1707   if (type1 == long_long_unsigned_type_node)
1708     return long_long_integer_type_node;
1709   if (type1 == widest_unsigned_literal_type_node)
1710     return widest_integer_literal_type_node;
1711 #if HOST_BITS_PER_WIDE_INT >= 64
1712   if (type1 == unsigned_intTI_type_node)
1713     return intTI_type_node;
1714 #endif
1715   if (type1 == unsigned_intDI_type_node)
1716     return intDI_type_node;
1717   if (type1 == unsigned_intSI_type_node)
1718     return intSI_type_node;
1719   if (type1 == unsigned_intHI_type_node)
1720     return intHI_type_node;
1721   if (type1 == unsigned_intQI_type_node)
1722     return intQI_type_node;
1723
1724   return c_common_signed_or_unsigned_type (0, type);
1725 }
1726
1727 /* Return a type the same as TYPE except unsigned or
1728    signed according to UNSIGNEDP.  */
1729
1730 tree
1731 c_common_signed_or_unsigned_type (int unsignedp, tree type)
1732 {
1733   if (!INTEGRAL_TYPE_P (type)
1734       || TYPE_UNSIGNED (type) == unsignedp)
1735     return type;
1736
1737   /* For ENUMERAL_TYPEs in C++, must check the mode of the types, not
1738      the precision; they have precision set to match their range, but
1739      may use a wider mode to match an ABI.  If we change modes, we may
1740      wind up with bad conversions.  For INTEGER_TYPEs in C, must check
1741      the precision as well, so as to yield correct results for
1742      bit-field types.  C++ does not have these separate bit-field
1743      types, and producing a signed or unsigned variant of an
1744      ENUMERAL_TYPE may cause other problems as well.  */
1745
1746 #define TYPE_OK(node)                                                       \
1747   (TYPE_MODE (type) == TYPE_MODE (node)                                     \
1748    && (c_dialect_cxx () || TYPE_PRECISION (type) == TYPE_PRECISION (node)))
1749   if (TYPE_OK (signed_char_type_node))
1750     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1751   if (TYPE_OK (integer_type_node))
1752     return unsignedp ? unsigned_type_node : integer_type_node;
1753   if (TYPE_OK (short_integer_type_node))
1754     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1755   if (TYPE_OK (long_integer_type_node))
1756     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1757   if (TYPE_OK (long_long_integer_type_node))
1758     return (unsignedp ? long_long_unsigned_type_node
1759             : long_long_integer_type_node);
1760   if (TYPE_OK (widest_integer_literal_type_node))
1761     return (unsignedp ? widest_unsigned_literal_type_node
1762             : widest_integer_literal_type_node);
1763
1764 #if HOST_BITS_PER_WIDE_INT >= 64
1765   if (TYPE_OK (intTI_type_node))
1766     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
1767 #endif
1768   if (TYPE_OK (intDI_type_node))
1769     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1770   if (TYPE_OK (intSI_type_node))
1771     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1772   if (TYPE_OK (intHI_type_node))
1773     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1774   if (TYPE_OK (intQI_type_node))
1775     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1776 #undef TYPE_OK
1777
1778   if (c_dialect_cxx ())
1779     return type;
1780   else
1781     return build_nonstandard_integer_type (TYPE_PRECISION (type), unsignedp);
1782 }
1783
1784 /* The C version of the register_builtin_type langhook.  */
1785
1786 void
1787 c_register_builtin_type (tree type, const char* name)
1788 {
1789   tree decl;
1790
1791   decl = build_decl (TYPE_DECL, get_identifier (name), type);
1792   DECL_ARTIFICIAL (decl) = 1;
1793   if (!TYPE_NAME (type))
1794     TYPE_NAME (type) = decl;
1795   pushdecl (decl);
1796
1797   registered_builtin_types = tree_cons (0, type, registered_builtin_types);
1798 }
1799
1800 \f
1801 /* Return the minimum number of bits needed to represent VALUE in a
1802    signed or unsigned type, UNSIGNEDP says which.  */
1803
1804 unsigned int
1805 min_precision (tree value, int unsignedp)
1806 {
1807   int log;
1808
1809   /* If the value is negative, compute its negative minus 1.  The latter
1810      adjustment is because the absolute value of the largest negative value
1811      is one larger than the largest positive value.  This is equivalent to
1812      a bit-wise negation, so use that operation instead.  */
1813
1814   if (tree_int_cst_sgn (value) < 0)
1815     value = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (value), value);
1816
1817   /* Return the number of bits needed, taking into account the fact
1818      that we need one more bit for a signed than unsigned type.  */
1819
1820   if (integer_zerop (value))
1821     log = 0;
1822   else
1823     log = tree_floor_log2 (value);
1824
1825   return log + 1 + !unsignedp;
1826 }
1827 \f
1828 /* Print an error message for invalid operands to arith operation
1829    CODE.  NOP_EXPR is used as a special case (see
1830    c_common_truthvalue_conversion).  */
1831
1832 void
1833 binary_op_error (enum tree_code code)
1834 {
1835   const char *opname;
1836
1837   switch (code)
1838     {
1839     case NOP_EXPR:
1840       error ("invalid truth-value expression");
1841       return;
1842
1843     case PLUS_EXPR:
1844       opname = "+"; break;
1845     case MINUS_EXPR:
1846       opname = "-"; break;
1847     case MULT_EXPR:
1848       opname = "*"; break;
1849     case MAX_EXPR:
1850       opname = "max"; break;
1851     case MIN_EXPR:
1852       opname = "min"; break;
1853     case EQ_EXPR:
1854       opname = "=="; break;
1855     case NE_EXPR:
1856       opname = "!="; break;
1857     case LE_EXPR:
1858       opname = "<="; break;
1859     case GE_EXPR:
1860       opname = ">="; break;
1861     case LT_EXPR:
1862       opname = "<"; break;
1863     case GT_EXPR:
1864       opname = ">"; break;
1865     case LSHIFT_EXPR:
1866       opname = "<<"; break;
1867     case RSHIFT_EXPR:
1868       opname = ">>"; break;
1869     case TRUNC_MOD_EXPR:
1870     case FLOOR_MOD_EXPR:
1871       opname = "%"; break;
1872     case TRUNC_DIV_EXPR:
1873     case FLOOR_DIV_EXPR:
1874       opname = "/"; break;
1875     case BIT_AND_EXPR:
1876       opname = "&"; break;
1877     case BIT_IOR_EXPR:
1878       opname = "|"; break;
1879     case TRUTH_ANDIF_EXPR:
1880       opname = "&&"; break;
1881     case TRUTH_ORIF_EXPR:
1882       opname = "||"; break;
1883     case BIT_XOR_EXPR:
1884       opname = "^"; break;
1885     default:
1886       gcc_unreachable ();
1887     }
1888   error ("invalid operands to binary %s", opname);
1889 }
1890 \f
1891 /* Subroutine of build_binary_op, used for comparison operations.
1892    See if the operands have both been converted from subword integer types
1893    and, if so, perhaps change them both back to their original type.
1894    This function is also responsible for converting the two operands
1895    to the proper common type for comparison.
1896
1897    The arguments of this function are all pointers to local variables
1898    of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
1899    RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.
1900
1901    If this function returns nonzero, it means that the comparison has
1902    a constant value.  What this function returns is an expression for
1903    that value.  */
1904
1905 tree
1906 shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr,
1907                  enum tree_code *rescode_ptr)
1908 {
1909   tree type;
1910   tree op0 = *op0_ptr;
1911   tree op1 = *op1_ptr;
1912   int unsignedp0, unsignedp1;
1913   int real1, real2;
1914   tree primop0, primop1;
1915   enum tree_code code = *rescode_ptr;
1916
1917   /* Throw away any conversions to wider types
1918      already present in the operands.  */
1919
1920   primop0 = get_narrower (op0, &unsignedp0);
1921   primop1 = get_narrower (op1, &unsignedp1);
1922
1923   /* Handle the case that OP0 does not *contain* a conversion
1924      but it *requires* conversion to FINAL_TYPE.  */
1925
1926   if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
1927     unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0));
1928   if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
1929     unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1));
1930
1931   /* If one of the operands must be floated, we cannot optimize.  */
1932   real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
1933   real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
1934
1935   /* If first arg is constant, swap the args (changing operation
1936      so value is preserved), for canonicalization.  Don't do this if
1937      the second arg is 0.  */
1938
1939   if (TREE_CONSTANT (primop0)
1940       && !integer_zerop (primop1) && !real_zerop (primop1))
1941     {
1942       tree tem = primop0;
1943       int temi = unsignedp0;
1944       primop0 = primop1;
1945       primop1 = tem;
1946       tem = op0;
1947       op0 = op1;
1948       op1 = tem;
1949       *op0_ptr = op0;
1950       *op1_ptr = op1;
1951       unsignedp0 = unsignedp1;
1952       unsignedp1 = temi;
1953       temi = real1;
1954       real1 = real2;
1955       real2 = temi;
1956
1957       switch (code)
1958         {
1959         case LT_EXPR:
1960           code = GT_EXPR;
1961           break;
1962         case GT_EXPR:
1963           code = LT_EXPR;
1964           break;
1965         case LE_EXPR:
1966           code = GE_EXPR;
1967           break;
1968         case GE_EXPR:
1969           code = LE_EXPR;
1970           break;
1971         default:
1972           break;
1973         }
1974       *rescode_ptr = code;
1975     }
1976
1977   /* If comparing an integer against a constant more bits wide,
1978      maybe we can deduce a value of 1 or 0 independent of the data.
1979      Or else truncate the constant now
1980      rather than extend the variable at run time.
1981
1982      This is only interesting if the constant is the wider arg.
1983      Also, it is not safe if the constant is unsigned and the
1984      variable arg is signed, since in this case the variable
1985      would be sign-extended and then regarded as unsigned.
1986      Our technique fails in this case because the lowest/highest
1987      possible unsigned results don't follow naturally from the
1988      lowest/highest possible values of the variable operand.
1989      For just EQ_EXPR and NE_EXPR there is another technique that
1990      could be used: see if the constant can be faithfully represented
1991      in the other operand's type, by truncating it and reextending it
1992      and see if that preserves the constant's value.  */
1993
1994   if (!real1 && !real2
1995       && TREE_CODE (primop1) == INTEGER_CST
1996       && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
1997     {
1998       int min_gt, max_gt, min_lt, max_lt;
1999       tree maxval, minval;
2000       /* 1 if comparison is nominally unsigned.  */
2001       int unsignedp = TYPE_UNSIGNED (*restype_ptr);
2002       tree val;
2003
2004       type = c_common_signed_or_unsigned_type (unsignedp0,
2005                                                TREE_TYPE (primop0));
2006
2007       maxval = TYPE_MAX_VALUE (type);
2008       minval = TYPE_MIN_VALUE (type);
2009
2010       if (unsignedp && !unsignedp0)
2011         *restype_ptr = c_common_signed_type (*restype_ptr);
2012
2013       if (TREE_TYPE (primop1) != *restype_ptr)
2014         {
2015           /* Convert primop1 to target type, but do not introduce
2016              additional overflow.  We know primop1 is an int_cst.  */
2017           tree tmp = build_int_cst_wide (*restype_ptr,
2018                                          TREE_INT_CST_LOW (primop1),
2019                                          TREE_INT_CST_HIGH (primop1));
2020
2021           primop1 = force_fit_type (tmp, 0, TREE_OVERFLOW (primop1),
2022                                     TREE_CONSTANT_OVERFLOW (primop1));
2023         }
2024       if (type != *restype_ptr)
2025         {
2026           minval = convert (*restype_ptr, minval);
2027           maxval = convert (*restype_ptr, maxval);
2028         }
2029
2030       if (unsignedp && unsignedp0)
2031         {
2032           min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
2033           max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
2034           min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
2035           max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
2036         }
2037       else
2038         {
2039           min_gt = INT_CST_LT (primop1, minval);
2040           max_gt = INT_CST_LT (primop1, maxval);
2041           min_lt = INT_CST_LT (minval, primop1);
2042           max_lt = INT_CST_LT (maxval, primop1);
2043         }
2044
2045       val = 0;
2046       /* This used to be a switch, but Genix compiler can't handle that.  */
2047       if (code == NE_EXPR)
2048         {
2049           if (max_lt || min_gt)
2050             val = truthvalue_true_node;
2051         }
2052       else if (code == EQ_EXPR)
2053         {
2054           if (max_lt || min_gt)
2055             val = truthvalue_false_node;
2056         }
2057       else if (code == LT_EXPR)
2058         {
2059           if (max_lt)
2060             val = truthvalue_true_node;
2061           if (!min_lt)
2062             val = truthvalue_false_node;
2063         }
2064       else if (code == GT_EXPR)
2065         {
2066           if (min_gt)
2067             val = truthvalue_true_node;
2068           if (!max_gt)
2069             val = truthvalue_false_node;
2070         }
2071       else if (code == LE_EXPR)
2072         {
2073           if (!max_gt)
2074             val = truthvalue_true_node;
2075           if (min_gt)
2076             val = truthvalue_false_node;
2077         }
2078       else if (code == GE_EXPR)
2079         {
2080           if (!min_lt)
2081             val = truthvalue_true_node;
2082           if (max_lt)
2083             val = truthvalue_false_node;
2084         }
2085
2086       /* If primop0 was sign-extended and unsigned comparison specd,
2087          we did a signed comparison above using the signed type bounds.
2088          But the comparison we output must be unsigned.
2089
2090          Also, for inequalities, VAL is no good; but if the signed
2091          comparison had *any* fixed result, it follows that the
2092          unsigned comparison just tests the sign in reverse
2093          (positive values are LE, negative ones GE).
2094          So we can generate an unsigned comparison
2095          against an extreme value of the signed type.  */
2096
2097       if (unsignedp && !unsignedp0)
2098         {
2099           if (val != 0)
2100             switch (code)
2101               {
2102               case LT_EXPR:
2103               case GE_EXPR:
2104                 primop1 = TYPE_MIN_VALUE (type);
2105                 val = 0;
2106                 break;
2107
2108               case LE_EXPR:
2109               case GT_EXPR:
2110                 primop1 = TYPE_MAX_VALUE (type);
2111                 val = 0;
2112                 break;
2113
2114               default:
2115                 break;
2116               }
2117           type = c_common_unsigned_type (type);
2118         }
2119
2120       if (TREE_CODE (primop0) != INTEGER_CST)
2121         {
2122           if (val == truthvalue_false_node)
2123             warning (0, "comparison is always false due to limited range of data type");
2124           if (val == truthvalue_true_node)
2125             warning (0, "comparison is always true due to limited range of data type");
2126         }
2127
2128       if (val != 0)
2129         {
2130           /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2131           if (TREE_SIDE_EFFECTS (primop0))
2132             return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
2133           return val;
2134         }
2135
2136       /* Value is not predetermined, but do the comparison
2137          in the type of the operand that is not constant.
2138          TYPE is already properly set.  */
2139     }
2140   else if (real1 && real2
2141            && (TYPE_PRECISION (TREE_TYPE (primop0))
2142                == TYPE_PRECISION (TREE_TYPE (primop1))))
2143     type = TREE_TYPE (primop0);
2144
2145   /* If args' natural types are both narrower than nominal type
2146      and both extend in the same manner, compare them
2147      in the type of the wider arg.
2148      Otherwise must actually extend both to the nominal
2149      common type lest different ways of extending
2150      alter the result.
2151      (eg, (short)-1 == (unsigned short)-1  should be 0.)  */
2152
2153   else if (unsignedp0 == unsignedp1 && real1 == real2
2154            && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
2155            && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
2156     {
2157       type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
2158       type = c_common_signed_or_unsigned_type (unsignedp0
2159                                                || TYPE_UNSIGNED (*restype_ptr),
2160                                                type);
2161       /* Make sure shorter operand is extended the right way
2162          to match the longer operand.  */
2163       primop0
2164         = convert (c_common_signed_or_unsigned_type (unsignedp0,
2165                                                      TREE_TYPE (primop0)),
2166                    primop0);
2167       primop1
2168         = convert (c_common_signed_or_unsigned_type (unsignedp1,
2169                                                      TREE_TYPE (primop1)),
2170                    primop1);
2171     }
2172   else
2173     {
2174       /* Here we must do the comparison on the nominal type
2175          using the args exactly as we received them.  */
2176       type = *restype_ptr;
2177       primop0 = op0;
2178       primop1 = op1;
2179
2180       if (!real1 && !real2 && integer_zerop (primop1)
2181           && TYPE_UNSIGNED (*restype_ptr))
2182         {
2183           tree value = 0;
2184           switch (code)
2185             {
2186             case GE_EXPR:
2187               /* All unsigned values are >= 0, so we warn if extra warnings
2188                  are requested.  However, if OP0 is a constant that is
2189                  >= 0, the signedness of the comparison isn't an issue,
2190                  so suppress the warning.  */
2191               if (extra_warnings && !in_system_header
2192                   && !(TREE_CODE (primop0) == INTEGER_CST
2193                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
2194                                                    primop0))))
2195                 warning (0, "comparison of unsigned expression >= 0 is always true");
2196               value = truthvalue_true_node;
2197               break;
2198
2199             case LT_EXPR:
2200               if (extra_warnings && !in_system_header
2201                   && !(TREE_CODE (primop0) == INTEGER_CST
2202                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
2203                                                    primop0))))
2204                 warning (0, "comparison of unsigned expression < 0 is always false");
2205               value = truthvalue_false_node;
2206               break;
2207
2208             default:
2209               break;
2210             }
2211
2212           if (value != 0)
2213             {
2214               /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2215               if (TREE_SIDE_EFFECTS (primop0))
2216                 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2217                                primop0, value);
2218               return value;
2219             }
2220         }
2221     }
2222
2223   *op0_ptr = convert (type, primop0);
2224   *op1_ptr = convert (type, primop1);
2225
2226   *restype_ptr = truthvalue_type_node;
2227
2228   return 0;
2229 }
2230 \f
2231 /* Return a tree for the sum or difference (RESULTCODE says which)
2232    of pointer PTROP and integer INTOP.  */
2233
2234 tree
2235 pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
2236 {
2237   tree size_exp;
2238
2239   /* The result is a pointer of the same type that is being added.  */
2240
2241   tree result_type = TREE_TYPE (ptrop);
2242
2243   if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
2244     {
2245       if (pedantic || warn_pointer_arith)
2246         pedwarn ("pointer of type %<void *%> used in arithmetic");
2247       size_exp = integer_one_node;
2248     }
2249   else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE)
2250     {
2251       if (pedantic || warn_pointer_arith)
2252         pedwarn ("pointer to a function used in arithmetic");
2253       size_exp = integer_one_node;
2254     }
2255   else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE)
2256     {
2257       if (pedantic || warn_pointer_arith)
2258         pedwarn ("pointer to member function used in arithmetic");
2259       size_exp = integer_one_node;
2260     }
2261   else
2262     size_exp = size_in_bytes (TREE_TYPE (result_type));
2263
2264   /* If what we are about to multiply by the size of the elements
2265      contains a constant term, apply distributive law
2266      and multiply that constant term separately.
2267      This helps produce common subexpressions.  */
2268
2269   if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
2270       && !TREE_CONSTANT (intop)
2271       && TREE_CONSTANT (TREE_OPERAND (intop, 1))
2272       && TREE_CONSTANT (size_exp)
2273       /* If the constant comes from pointer subtraction,
2274          skip this optimization--it would cause an error.  */
2275       && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
2276       /* If the constant is unsigned, and smaller than the pointer size,
2277          then we must skip this optimization.  This is because it could cause
2278          an overflow error if the constant is negative but INTOP is not.  */
2279       && (!TYPE_UNSIGNED (TREE_TYPE (intop))
2280           || (TYPE_PRECISION (TREE_TYPE (intop))
2281               == TYPE_PRECISION (TREE_TYPE (ptrop)))))
2282     {
2283       enum tree_code subcode = resultcode;
2284       tree int_type = TREE_TYPE (intop);
2285       if (TREE_CODE (intop) == MINUS_EXPR)
2286         subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
2287       /* Convert both subexpression types to the type of intop,
2288          because weird cases involving pointer arithmetic
2289          can result in a sum or difference with different type args.  */
2290       ptrop = build_binary_op (subcode, ptrop,
2291                                convert (int_type, TREE_OPERAND (intop, 1)), 1);
2292       intop = convert (int_type, TREE_OPERAND (intop, 0));
2293     }
2294
2295   /* Convert the integer argument to a type the same size as sizetype
2296      so the multiply won't overflow spuriously.  */
2297
2298   if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype)
2299       || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype))
2300     intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype),
2301                                              TYPE_UNSIGNED (sizetype)), intop);
2302
2303   /* Replace the integer argument with a suitable product by the object size.
2304      Do this multiplication as signed, then convert to the appropriate
2305      pointer type (actually unsigned integral).  */
2306
2307   intop = convert (result_type,
2308                    build_binary_op (MULT_EXPR, intop,
2309                                     convert (TREE_TYPE (intop), size_exp), 1));
2310
2311   /* Create the sum or difference.  */
2312   return fold_build2 (resultcode, result_type, ptrop, intop);
2313 }
2314 \f
2315 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
2316    or for an `if' or `while' statement or ?..: exp.  It should already
2317    have been validated to be of suitable type; otherwise, a bad
2318    diagnostic may result.
2319
2320    This preparation consists of taking the ordinary
2321    representation of an expression expr and producing a valid tree
2322    boolean expression describing whether expr is nonzero.  We could
2323    simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1),
2324    but we optimize comparisons, &&, ||, and !.
2325
2326    The resulting type should always be `truthvalue_type_node'.  */
2327
2328 tree
2329 c_common_truthvalue_conversion (tree expr)
2330 {
2331   switch (TREE_CODE (expr))
2332     {
2333     case EQ_EXPR:   case NE_EXPR:   case UNEQ_EXPR: case LTGT_EXPR:
2334     case LE_EXPR:   case GE_EXPR:   case LT_EXPR:   case GT_EXPR:
2335     case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR:
2336     case ORDERED_EXPR: case UNORDERED_EXPR:
2337       if (TREE_TYPE (expr) == truthvalue_type_node)
2338         return expr;
2339       return build2 (TREE_CODE (expr), truthvalue_type_node,
2340                      TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1));
2341
2342     case TRUTH_ANDIF_EXPR:
2343     case TRUTH_ORIF_EXPR:
2344     case TRUTH_AND_EXPR:
2345     case TRUTH_OR_EXPR:
2346     case TRUTH_XOR_EXPR:
2347       if (TREE_TYPE (expr) == truthvalue_type_node)
2348         return expr;
2349       return build2 (TREE_CODE (expr), truthvalue_type_node,
2350                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)),
2351                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)));
2352
2353     case TRUTH_NOT_EXPR:
2354       if (TREE_TYPE (expr) == truthvalue_type_node)
2355         return expr;
2356       return build1 (TREE_CODE (expr), truthvalue_type_node,
2357                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)));
2358
2359     case ERROR_MARK:
2360       return expr;
2361
2362     case INTEGER_CST:
2363       /* Avoid integer_zerop to ignore TREE_CONSTANT_OVERFLOW.  */
2364       return (TREE_INT_CST_LOW (expr) != 0 || TREE_INT_CST_HIGH (expr) != 0)
2365              ? truthvalue_true_node
2366              : truthvalue_false_node;
2367
2368     case REAL_CST:
2369       return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0)
2370              ? truthvalue_true_node
2371              : truthvalue_false_node;
2372
2373     case FUNCTION_DECL:
2374       expr = build_unary_op (ADDR_EXPR, expr, 0);
2375       /* Fall through.  */
2376
2377     case ADDR_EXPR:
2378       {
2379         if (TREE_CODE (TREE_OPERAND (expr, 0)) == FUNCTION_DECL
2380             && !DECL_WEAK (TREE_OPERAND (expr, 0)))
2381           {
2382             /* Common Ada/Pascal programmer's mistake.  We always warn
2383                about this since it is so bad.  */
2384             warning (0, "the address of %qD, will always evaluate as %<true%>",
2385                      TREE_OPERAND (expr, 0));
2386             return truthvalue_true_node;
2387           }
2388
2389         /* If we are taking the address of an external decl, it might be
2390            zero if it is weak, so we cannot optimize.  */
2391         if (DECL_P (TREE_OPERAND (expr, 0))
2392             && DECL_EXTERNAL (TREE_OPERAND (expr, 0)))
2393           break;
2394
2395         if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 0)))
2396           return build2 (COMPOUND_EXPR, truthvalue_type_node,
2397                          TREE_OPERAND (expr, 0), truthvalue_true_node);
2398         else
2399           return truthvalue_true_node;
2400       }
2401
2402     case COMPLEX_EXPR:
2403       return build_binary_op ((TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
2404                                ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
2405                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)),
2406                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
2407                               0);
2408
2409     case NEGATE_EXPR:
2410     case ABS_EXPR:
2411     case FLOAT_EXPR:
2412       /* These don't change whether an object is nonzero or zero.  */
2413       return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
2414
2415     case LROTATE_EXPR:
2416     case RROTATE_EXPR:
2417       /* These don't change whether an object is zero or nonzero, but
2418          we can't ignore them if their second arg has side-effects.  */
2419       if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2420         return build2 (COMPOUND_EXPR, truthvalue_type_node,
2421                        TREE_OPERAND (expr, 1),
2422                        c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)));
2423       else
2424         return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
2425
2426     case COND_EXPR:
2427       /* Distribute the conversion into the arms of a COND_EXPR.  */
2428       return fold_build3 (COND_EXPR, truthvalue_type_node,
2429                 TREE_OPERAND (expr, 0),
2430                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
2431                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 2)));
2432
2433     case CONVERT_EXPR:
2434       /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
2435          since that affects how `default_conversion' will behave.  */
2436       if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
2437           || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
2438         break;
2439       /* Fall through....  */
2440     case NOP_EXPR:
2441       /* If this is widening the argument, we can ignore it.  */
2442       if (TYPE_PRECISION (TREE_TYPE (expr))
2443           >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
2444         return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
2445       break;
2446
2447     case MINUS_EXPR:
2448       /* Perhaps reduce (x - y) != 0 to (x != y).  The expressions
2449          aren't guaranteed to the be same for modes that can represent
2450          infinity, since if x and y are both +infinity, or both
2451          -infinity, then x - y is not a number.
2452
2453          Note that this transformation is safe when x or y is NaN.
2454          (x - y) is then NaN, and both (x - y) != 0 and x != y will
2455          be false.  */
2456       if (HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (TREE_OPERAND (expr, 0)))))
2457         break;
2458       /* Fall through....  */
2459     case BIT_XOR_EXPR:
2460       /* This and MINUS_EXPR can be changed into a comparison of the
2461          two objects.  */
2462       if (TREE_TYPE (TREE_OPERAND (expr, 0))
2463           == TREE_TYPE (TREE_OPERAND (expr, 1)))
2464         return fold_build2 (NE_EXPR, truthvalue_type_node,
2465                             TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1));
2466       return fold_build2 (NE_EXPR, truthvalue_type_node,
2467                           TREE_OPERAND (expr, 0),
2468                           fold_convert (TREE_TYPE (TREE_OPERAND (expr, 0)),
2469                                         TREE_OPERAND (expr, 1)));
2470
2471     case BIT_AND_EXPR:
2472       if (integer_onep (TREE_OPERAND (expr, 1))
2473           && TREE_TYPE (expr) != truthvalue_type_node)
2474         /* Using convert here would cause infinite recursion.  */
2475         return build1 (NOP_EXPR, truthvalue_type_node, expr);
2476       break;
2477
2478     case MODIFY_EXPR:
2479       if (!TREE_NO_WARNING (expr))
2480         warning (OPT_Wparentheses,
2481                  "suggest parentheses around assignment used as truth value");
2482       break;
2483
2484     default:
2485       break;
2486     }
2487
2488   if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
2489     {
2490       tree t = save_expr (expr);
2491       return (build_binary_op
2492               ((TREE_SIDE_EFFECTS (expr)
2493                 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
2494         c_common_truthvalue_conversion (build_unary_op (REALPART_EXPR, t, 0)),
2495         c_common_truthvalue_conversion (build_unary_op (IMAGPART_EXPR, t, 0)),
2496                0));
2497     }
2498
2499   return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
2500 }
2501 \f
2502 static tree builtin_function_2 (const char *builtin_name, const char *name,
2503                                 tree builtin_type, tree type,
2504                                 enum built_in_function function_code,
2505                                 enum built_in_class cl, int library_name_p,
2506                                 bool nonansi_p,
2507                                 tree attrs);
2508
2509 /* Make a variant type in the proper way for C/C++, propagating qualifiers
2510    down to the element type of an array.  */
2511
2512 tree
2513 c_build_qualified_type (tree type, int type_quals)
2514 {
2515   if (type == error_mark_node)
2516     return type;
2517
2518   if (TREE_CODE (type) == ARRAY_TYPE)
2519     {
2520       tree t;
2521       tree element_type = c_build_qualified_type (TREE_TYPE (type),
2522                                                   type_quals);
2523
2524       /* See if we already have an identically qualified type.  */
2525       for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
2526         {
2527           if (TYPE_QUALS (strip_array_types (t)) == type_quals
2528               && TYPE_NAME (t) == TYPE_NAME (type)
2529               && TYPE_CONTEXT (t) == TYPE_CONTEXT (type)
2530               && attribute_list_equal (TYPE_ATTRIBUTES (t),
2531                                        TYPE_ATTRIBUTES (type)))
2532             break;
2533         }
2534       if (!t)
2535         {
2536           t = build_variant_type_copy (type);
2537           TREE_TYPE (t) = element_type;
2538         }
2539       return t;
2540     }
2541
2542   /* A restrict-qualified pointer type must be a pointer to object or
2543      incomplete type.  Note that the use of POINTER_TYPE_P also allows
2544      REFERENCE_TYPEs, which is appropriate for C++.  */
2545   if ((type_quals & TYPE_QUAL_RESTRICT)
2546       && (!POINTER_TYPE_P (type)
2547           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type))))
2548     {
2549       error ("invalid use of %<restrict%>");
2550       type_quals &= ~TYPE_QUAL_RESTRICT;
2551     }
2552
2553   return build_qualified_type (type, type_quals);
2554 }
2555
2556 /* Apply the TYPE_QUALS to the new DECL.  */
2557
2558 void
2559 c_apply_type_quals_to_decl (int type_quals, tree decl)
2560 {
2561   tree type = TREE_TYPE (decl);
2562
2563   if (type == error_mark_node)
2564     return;
2565
2566   if (((type_quals & TYPE_QUAL_CONST)
2567        || (type && TREE_CODE (type) == REFERENCE_TYPE))
2568       /* An object declared 'const' is only readonly after it is
2569          initialized.  We don't have any way of expressing this currently,
2570          so we need to be conservative and unset TREE_READONLY for types
2571          with constructors.  Otherwise aliasing code will ignore stores in
2572          an inline constructor.  */
2573       && !(type && TYPE_NEEDS_CONSTRUCTING (type)))
2574     TREE_READONLY (decl) = 1;
2575   if (type_quals & TYPE_QUAL_VOLATILE)
2576     {
2577       TREE_SIDE_EFFECTS (decl) = 1;
2578       TREE_THIS_VOLATILE (decl) = 1;
2579     }
2580   if (type_quals & TYPE_QUAL_RESTRICT)
2581     {
2582       while (type && TREE_CODE (type) == ARRAY_TYPE)
2583         /* Allow 'restrict' on arrays of pointers.
2584            FIXME currently we just ignore it.  */
2585         type = TREE_TYPE (type);
2586       if (!type
2587           || !POINTER_TYPE_P (type)
2588           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))
2589         error ("invalid use of %<restrict%>");
2590       else if (flag_strict_aliasing && type == TREE_TYPE (decl))
2591         /* Indicate we need to make a unique alias set for this pointer.
2592            We can't do it here because it might be pointing to an
2593            incomplete type.  */
2594         DECL_POINTER_ALIAS_SET (decl) = -2;
2595     }
2596 }
2597
2598 /* Hash function for the problem of multiple type definitions in
2599    different files.  This must hash all types that will compare
2600    equal via comptypes to the same value.  In practice it hashes
2601    on some of the simple stuff and leaves the details to comptypes.  */
2602
2603 static hashval_t
2604 c_type_hash (const void *p)
2605 {
2606   int i = 0;
2607   int shift, size;
2608   tree t = (tree) p;
2609   tree t2;
2610   switch (TREE_CODE (t))
2611     {
2612     /* For pointers, hash on pointee type plus some swizzling.  */
2613     case POINTER_TYPE:
2614       return c_type_hash (TREE_TYPE (t)) ^ 0x3003003;
2615     /* Hash on number of elements and total size.  */
2616     case ENUMERAL_TYPE:
2617       shift = 3;
2618       t2 = TYPE_VALUES (t);
2619       break;
2620     case RECORD_TYPE:
2621       shift = 0;
2622       t2 = TYPE_FIELDS (t);
2623       break;
2624     case QUAL_UNION_TYPE:
2625       shift = 1;
2626       t2 = TYPE_FIELDS (t);
2627       break;
2628     case UNION_TYPE:
2629       shift = 2;
2630       t2 = TYPE_FIELDS (t);
2631       break;
2632     default:
2633       gcc_unreachable ();
2634     }
2635   for (; t2; t2 = TREE_CHAIN (t2))
2636     i++;
2637   size = TREE_INT_CST_LOW (TYPE_SIZE (t));
2638   return ((size << 24) | (i << shift));
2639 }
2640
2641 static GTY((param_is (union tree_node))) htab_t type_hash_table;
2642
2643 /* Return the typed-based alias set for T, which may be an expression
2644    or a type.  Return -1 if we don't do anything special.  */
2645
2646 HOST_WIDE_INT
2647 c_common_get_alias_set (tree t)
2648 {
2649   tree u;
2650   PTR *slot;
2651
2652   /* Permit type-punning when accessing a union, provided the access
2653      is directly through the union.  For example, this code does not
2654      permit taking the address of a union member and then storing
2655      through it.  Even the type-punning allowed here is a GCC
2656      extension, albeit a common and useful one; the C standard says
2657      that such accesses have implementation-defined behavior.  */
2658   for (u = t;
2659        TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
2660        u = TREE_OPERAND (u, 0))
2661     if (TREE_CODE (u) == COMPONENT_REF
2662         && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
2663       return 0;
2664
2665   /* That's all the expressions we handle specially.  */
2666   if (!TYPE_P (t))
2667     return -1;
2668
2669   /* The C standard guarantees that any object may be accessed via an
2670      lvalue that has character type.  */
2671   if (t == char_type_node
2672       || t == signed_char_type_node
2673       || t == unsigned_char_type_node)
2674     return 0;
2675
2676   /* If it has the may_alias attribute, it can alias anything.  */
2677   if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (t)))
2678     return 0;
2679
2680   /* The C standard specifically allows aliasing between signed and
2681      unsigned variants of the same type.  We treat the signed
2682      variant as canonical.  */
2683   if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t))
2684     {
2685       tree t1 = c_common_signed_type (t);
2686
2687       /* t1 == t can happen for boolean nodes which are always unsigned.  */
2688       if (t1 != t)
2689         return get_alias_set (t1);
2690     }
2691   else if (POINTER_TYPE_P (t))
2692     {
2693       tree t1;
2694
2695       /* Unfortunately, there is no canonical form of a pointer type.
2696          In particular, if we have `typedef int I', then `int *', and
2697          `I *' are different types.  So, we have to pick a canonical
2698          representative.  We do this below.
2699
2700          Technically, this approach is actually more conservative that
2701          it needs to be.  In particular, `const int *' and `int *'
2702          should be in different alias sets, according to the C and C++
2703          standard, since their types are not the same, and so,
2704          technically, an `int **' and `const int **' cannot point at
2705          the same thing.
2706
2707          But, the standard is wrong.  In particular, this code is
2708          legal C++:
2709
2710             int *ip;
2711             int **ipp = &ip;
2712             const int* const* cipp = ipp;
2713
2714          And, it doesn't make sense for that to be legal unless you
2715          can dereference IPP and CIPP.  So, we ignore cv-qualifiers on
2716          the pointed-to types.  This issue has been reported to the
2717          C++ committee.  */
2718       t1 = build_type_no_quals (t);
2719       if (t1 != t)
2720         return get_alias_set (t1);
2721     }
2722
2723   /* Handle the case of multiple type nodes referring to "the same" type,
2724      which occurs with IMA.  These share an alias set.  FIXME:  Currently only
2725      C90 is handled.  (In C99 type compatibility is not transitive, which
2726      complicates things mightily. The alias set splay trees can theoretically
2727      represent this, but insertion is tricky when you consider all the
2728      different orders things might arrive in.) */
2729
2730   if (c_language != clk_c || flag_isoc99)
2731     return -1;
2732
2733   /* Save time if there's only one input file.  */
2734   if (num_in_fnames == 1)
2735     return -1;
2736
2737   /* Pointers need special handling if they point to any type that
2738      needs special handling (below).  */
2739   if (TREE_CODE (t) == POINTER_TYPE)
2740     {
2741       tree t2;
2742       /* Find bottom type under any nested POINTERs.  */
2743       for (t2 = TREE_TYPE (t);
2744      TREE_CODE (t2) == POINTER_TYPE;
2745      t2 = TREE_TYPE (t2))
2746   ;
2747       if (TREE_CODE (t2) != RECORD_TYPE
2748     && TREE_CODE (t2) != ENUMERAL_TYPE
2749     && TREE_CODE (t2) != QUAL_UNION_TYPE
2750     && TREE_CODE (t2) != UNION_TYPE)
2751   return -1;
2752       if (TYPE_SIZE (t2) == 0)
2753   return -1;
2754     }
2755   /* These are the only cases that need special handling.  */
2756   if (TREE_CODE (t) != RECORD_TYPE
2757       && TREE_CODE (t) != ENUMERAL_TYPE
2758       && TREE_CODE (t) != QUAL_UNION_TYPE
2759       && TREE_CODE (t) != UNION_TYPE
2760       && TREE_CODE (t) != POINTER_TYPE)
2761     return -1;
2762   /* Undefined? */
2763   if (TYPE_SIZE (t) == 0)
2764     return -1;
2765
2766   /* Look up t in hash table.  Only one of the compatible types within each
2767      alias set is recorded in the table.  */
2768   if (!type_hash_table)
2769     type_hash_table = htab_create_ggc (1021, c_type_hash,
2770             (htab_eq) lang_hooks.types_compatible_p,
2771             NULL);
2772   slot = htab_find_slot (type_hash_table, t, INSERT);
2773   if (*slot != NULL)
2774     {
2775       TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot);
2776       return TYPE_ALIAS_SET ((tree)*slot);
2777     }
2778   else
2779     /* Our caller will assign and record (in t) a new alias set; all we need
2780        to do is remember t in the hash table.  */
2781     *slot = t;
2782
2783   return -1;
2784 }
2785 \f
2786 /* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where the
2787    second parameter indicates which OPERATOR is being applied.  The COMPLAIN
2788    flag controls whether we should diagnose possibly ill-formed
2789    constructs or not.  */
2790
2791 tree
2792 c_sizeof_or_alignof_type (tree type, bool is_sizeof, int complain)
2793 {
2794   const char *op_name;
2795   tree value = NULL;
2796   enum tree_code type_code = TREE_CODE (type);
2797
2798   op_name = is_sizeof ? "sizeof" : "__alignof__";
2799
2800   if (type_code == FUNCTION_TYPE)
2801     {
2802       if (is_sizeof)
2803         {
2804           if (complain && (pedantic || warn_pointer_arith))
2805             pedwarn ("invalid application of %<sizeof%> to a function type");
2806           value = size_one_node;
2807         }
2808       else
2809         value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);
2810     }
2811   else if (type_code == VOID_TYPE || type_code == ERROR_MARK)
2812     {
2813       if (type_code == VOID_TYPE
2814           && complain && (pedantic || warn_pointer_arith))
2815         pedwarn ("invalid application of %qs to a void type", op_name);
2816       value = size_one_node;
2817     }
2818   else if (!COMPLETE_TYPE_P (type))
2819     {
2820       if (complain)
2821         error ("invalid application of %qs to incomplete type %qT ",
2822                op_name, type);
2823       value = size_zero_node;
2824     }
2825   else
2826     {
2827       if (is_sizeof)
2828         /* Convert in case a char is more than one unit.  */
2829         value = size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
2830                             size_int (TYPE_PRECISION (char_type_node)
2831                                       / BITS_PER_UNIT));
2832       else
2833         value = size_int (TYPE_ALIGN_UNIT (type));
2834     }
2835
2836   /* VALUE will have an integer type with TYPE_IS_SIZETYPE set.
2837      TYPE_IS_SIZETYPE means that certain things (like overflow) will
2838      never happen.  However, this node should really have type
2839      `size_t', which is just a typedef for an ordinary integer type.  */
2840   value = fold_build1 (NOP_EXPR, size_type_node, value);
2841   gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value)));
2842
2843   return value;
2844 }
2845
2846 /* Implement the __alignof keyword: Return the minimum required
2847    alignment of EXPR, measured in bytes.  For VAR_DECL's and
2848    FIELD_DECL's return DECL_ALIGN (which can be set from an
2849    "aligned" __attribute__ specification).  */
2850
2851 tree
2852 c_alignof_expr (tree expr)
2853 {
2854   tree t;
2855
2856   if (TREE_CODE (expr) == VAR_DECL)
2857     t = size_int (DECL_ALIGN_UNIT (expr));
2858
2859   else if (TREE_CODE (expr) == COMPONENT_REF
2860            && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1)))
2861     {
2862       error ("%<__alignof%> applied to a bit-field");
2863       t = size_one_node;
2864     }
2865   else if (TREE_CODE (expr) == COMPONENT_REF
2866            && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL)
2867     t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1)));
2868
2869   else if (TREE_CODE (expr) == INDIRECT_REF)
2870     {
2871       tree t = TREE_OPERAND (expr, 0);
2872       tree best = t;
2873       int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
2874
2875       while (TREE_CODE (t) == NOP_EXPR
2876              && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE)
2877         {
2878           int thisalign;
2879
2880           t = TREE_OPERAND (t, 0);
2881           thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
2882           if (thisalign > bestalign)
2883             best = t, bestalign = thisalign;
2884         }
2885       return c_alignof (TREE_TYPE (TREE_TYPE (best)));
2886     }
2887   else
2888     return c_alignof (TREE_TYPE (expr));
2889
2890   return fold_build1 (NOP_EXPR, size_type_node, t);
2891 }
2892 \f
2893 /* Handle C and C++ default attributes.  */
2894
2895 enum built_in_attribute
2896 {
2897 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
2898 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
2899 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
2900 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
2901 #include "builtin-attrs.def"
2902 #undef DEF_ATTR_NULL_TREE
2903 #undef DEF_ATTR_INT
2904 #undef DEF_ATTR_IDENT
2905 #undef DEF_ATTR_TREE_LIST
2906   ATTR_LAST
2907 };
2908
2909 static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
2910
2911 static void c_init_attributes (void);
2912
2913 /* Build tree nodes and builtin functions common to both C and C++ language
2914    frontends.  */
2915
2916 void
2917 c_common_nodes_and_builtins (void)
2918 {
2919   enum builtin_type
2920   {
2921 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
2922 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
2923 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
2924 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
2925 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
2926 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
2927 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
2928 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) \
2929   NAME,
2930 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
2931 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
2932 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
2933 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
2934 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
2935 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \
2936   NAME,
2937 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
2938 #include "builtin-types.def"
2939 #undef DEF_PRIMITIVE_TYPE
2940 #undef DEF_FUNCTION_TYPE_0
2941 #undef DEF_FUNCTION_TYPE_1
2942 #undef DEF_FUNCTION_TYPE_2
2943 #undef DEF_FUNCTION_TYPE_3
2944 #undef DEF_FUNCTION_TYPE_4
2945 #undef DEF_FUNCTION_TYPE_5
2946 #undef DEF_FUNCTION_TYPE_6
2947 #undef DEF_FUNCTION_TYPE_VAR_0
2948 #undef DEF_FUNCTION_TYPE_VAR_1
2949 #undef DEF_FUNCTION_TYPE_VAR_2
2950 #undef DEF_FUNCTION_TYPE_VAR_3
2951 #undef DEF_FUNCTION_TYPE_VAR_4
2952 #undef DEF_FUNCTION_TYPE_VAR_5
2953 #undef DEF_POINTER_TYPE
2954     BT_LAST
2955   };
2956
2957   typedef enum builtin_type builtin_type;
2958
2959   tree builtin_types[(int) BT_LAST];
2960   int wchar_type_size;
2961   tree array_domain_type;
2962   tree va_list_ref_type_node;
2963   tree va_list_arg_type_node;
2964
2965   /* Define `int' and `char' first so that dbx will output them first.  */
2966   record_builtin_type (RID_INT, NULL, integer_type_node);
2967   record_builtin_type (RID_CHAR, "char", char_type_node);
2968
2969   /* `signed' is the same as `int'.  FIXME: the declarations of "signed",
2970      "unsigned long", "long long unsigned" and "unsigned short" were in C++
2971      but not C.  Are the conditionals here needed?  */
2972   if (c_dialect_cxx ())
2973     record_builtin_type (RID_SIGNED, NULL, integer_type_node);
2974   record_builtin_type (RID_LONG, "long int", long_integer_type_node);
2975   record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
2976   record_builtin_type (RID_MAX, "long unsigned int",
2977                        long_unsigned_type_node);
2978   if (c_dialect_cxx ())
2979     record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
2980   record_builtin_type (RID_MAX, "long long int",
2981                        long_long_integer_type_node);
2982   record_builtin_type (RID_MAX, "long long unsigned int",
2983                        long_long_unsigned_type_node);
2984   if (c_dialect_cxx ())
2985     record_builtin_type (RID_MAX, "long long unsigned",
2986                          long_long_unsigned_type_node);
2987   record_builtin_type (RID_SHORT, "short int", short_integer_type_node);
2988   record_builtin_type (RID_MAX, "short unsigned int",
2989                        short_unsigned_type_node);
2990   if (c_dialect_cxx ())
2991     record_builtin_type (RID_MAX, "unsigned short",
2992                          short_unsigned_type_node);
2993
2994   /* Define both `signed char' and `unsigned char'.  */
2995   record_builtin_type (RID_MAX, "signed char", signed_char_type_node);
2996   record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node);
2997
2998   /* These are types that c_common_type_for_size and
2999      c_common_type_for_mode use.  */
3000   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3001                                          intQI_type_node));
3002   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3003                                          intHI_type_node));
3004   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3005                                          intSI_type_node));
3006   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3007                                          intDI_type_node));
3008 #if HOST_BITS_PER_WIDE_INT >= 64
3009   if (targetm.scalar_mode_supported_p (TImode))
3010     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3011                                            get_identifier ("__int128_t"),
3012                                            intTI_type_node));
3013 #endif
3014   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3015                                          unsigned_intQI_type_node));
3016   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3017                                          unsigned_intHI_type_node));
3018   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3019                                          unsigned_intSI_type_node));
3020   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3021                                          unsigned_intDI_type_node));
3022 #if HOST_BITS_PER_WIDE_INT >= 64
3023   if (targetm.scalar_mode_supported_p (TImode))
3024     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3025                                            get_identifier ("__uint128_t"),
3026                                            unsigned_intTI_type_node));
3027 #endif
3028
3029   /* Create the widest literal types.  */
3030   widest_integer_literal_type_node
3031     = make_signed_type (HOST_BITS_PER_WIDE_INT * 2);
3032   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3033                                          widest_integer_literal_type_node));
3034
3035   widest_unsigned_literal_type_node
3036     = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2);
3037   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3038                                          widest_unsigned_literal_type_node));
3039
3040   /* `unsigned long' is the standard type for sizeof.
3041      Note that stddef.h uses `unsigned long',
3042      and this must agree, even if long and int are the same size.  */
3043   size_type_node =
3044     TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE)));
3045   signed_size_type_node = c_common_signed_type (size_type_node);
3046   set_sizetype (size_type_node);
3047
3048   pid_type_node =
3049     TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE)));
3050
3051   build_common_tree_nodes_2 (flag_short_double);
3052
3053   record_builtin_type (RID_FLOAT, NULL, float_type_node);
3054   record_builtin_type (RID_DOUBLE, NULL, double_type_node);
3055   record_builtin_type (RID_MAX, "long double", long_double_type_node);
3056
3057   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3058                                          get_identifier ("complex int"),
3059                                          complex_integer_type_node));
3060   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3061                                          get_identifier ("complex float"),
3062                                          complex_float_type_node));
3063   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3064                                          get_identifier ("complex double"),
3065                                          complex_double_type_node));
3066   lang_hooks.decls.pushdecl
3067     (build_decl (TYPE_DECL, get_identifier ("complex long double"),
3068                  complex_long_double_type_node));
3069
3070   if (c_dialect_cxx ())
3071     /* For C++, make fileptr_type_node a distinct void * type until
3072        FILE type is defined.  */
3073     fileptr_type_node = build_variant_type_copy (ptr_type_node);
3074
3075   record_builtin_type (RID_VOID, NULL, void_type_node);
3076
3077   /* This node must not be shared.  */
3078   void_zero_node = make_node (INTEGER_CST);
3079   TREE_TYPE (void_zero_node) = void_type_node;
3080
3081   void_list_node = build_void_list_node ();
3082
3083   /* Make a type to be the domain of a few array types
3084      whose domains don't really matter.
3085      200 is small enough that it always fits in size_t
3086      and large enough that it can hold most function names for the
3087      initializations of __FUNCTION__ and __PRETTY_FUNCTION__.  */
3088   array_domain_type = build_index_type (size_int (200));
3089
3090   /* Make a type for arrays of characters.
3091      With luck nothing will ever really depend on the length of this
3092      array type.  */
3093   char_array_type_node
3094     = build_array_type (char_type_node, array_domain_type);
3095
3096   /* Likewise for arrays of ints.  */
3097   int_array_type_node
3098     = build_array_type (integer_type_node, array_domain_type);
3099
3100   string_type_node = build_pointer_type (char_type_node);
3101   const_string_type_node
3102     = build_pointer_type (build_qualified_type
3103                           (char_type_node, TYPE_QUAL_CONST));
3104
3105   /* This is special for C++ so functions can be overloaded.  */
3106   wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE);
3107   wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node));
3108   wchar_type_size = TYPE_PRECISION (wchar_type_node);
3109   if (c_dialect_cxx ())
3110     {
3111       if (TYPE_UNSIGNED (wchar_type_node))
3112         wchar_type_node = make_unsigned_type (wchar_type_size);
3113       else
3114         wchar_type_node = make_signed_type (wchar_type_size);
3115       record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node);
3116     }
3117   else
3118     {
3119       signed_wchar_type_node = c_common_signed_type (wchar_type_node);
3120       unsigned_wchar_type_node = c_common_unsigned_type (wchar_type_node);
3121     }
3122
3123   /* This is for wide string constants.  */
3124   wchar_array_type_node
3125     = build_array_type (wchar_type_node, array_domain_type);
3126
3127   wint_type_node =
3128     TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE)));
3129
3130   intmax_type_node =
3131     TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE)));
3132   uintmax_type_node =
3133     TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE)));
3134
3135   default_function_type = build_function_type (integer_type_node, NULL_TREE);
3136   ptrdiff_type_node
3137     = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE)));
3138   unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node);
3139
3140   lang_hooks.decls.pushdecl
3141     (build_decl (TYPE_DECL, get_identifier ("__builtin_va_list"),
3142                  va_list_type_node));
3143
3144   if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
3145     {
3146       va_list_arg_type_node = va_list_ref_type_node =
3147         build_pointer_type (TREE_TYPE (va_list_type_node));
3148     }
3149   else
3150     {
3151       va_list_arg_type_node = va_list_type_node;
3152       va_list_ref_type_node = build_reference_type (va_list_type_node);
3153     }
3154
3155 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
3156   builtin_types[(int) ENUM] = VALUE;
3157 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN)               \
3158   builtin_types[(int) ENUM]                             \
3159     = build_function_type (builtin_types[(int) RETURN], \
3160                            void_list_node);
3161 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1)                         \
3162   builtin_types[(int) ENUM]                                             \
3163     = build_function_type (builtin_types[(int) RETURN],                 \
3164                            tree_cons (NULL_TREE,                        \
3165                                       builtin_types[(int) ARG1],        \
3166                                       void_list_node));
3167 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2)   \
3168   builtin_types[(int) ENUM]                             \
3169     = build_function_type                               \
3170       (builtin_types[(int) RETURN],                     \
3171        tree_cons (NULL_TREE,                            \
3172                   builtin_types[(int) ARG1],            \
3173                   tree_cons (NULL_TREE,                 \
3174                              builtin_types[(int) ARG2], \
3175                              void_list_node)));
3176 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3)              \
3177   builtin_types[(int) ENUM]                                              \
3178     = build_function_type                                                \
3179       (builtin_types[(int) RETURN],                                      \
3180        tree_cons (NULL_TREE,                                             \
3181                   builtin_types[(int) ARG1],                             \
3182                   tree_cons (NULL_TREE,                                  \
3183                              builtin_types[(int) ARG2],                  \
3184                              tree_cons (NULL_TREE,                       \
3185                                         builtin_types[(int) ARG3],       \
3186                                         void_list_node))));
3187 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4)       \
3188   builtin_types[(int) ENUM]                                             \
3189     = build_function_type                                               \
3190       (builtin_types[(int) RETURN],                                     \
3191        tree_cons (NULL_TREE,                                            \
3192                   builtin_types[(int) ARG1],                            \
3193                   tree_cons (NULL_TREE,                                 \
3194                              builtin_types[(int) ARG2],                 \
3195                              tree_cons                                  \
3196                              (NULL_TREE,                                \
3197                               builtin_types[(int) ARG3],                \
3198                               tree_cons (NULL_TREE,                     \
3199                                          builtin_types[(int) ARG4],     \
3200                                          void_list_node)))));
3201 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
3202   builtin_types[(int) ENUM]                                             \
3203     = build_function_type                                               \
3204       (builtin_types[(int) RETURN],                                     \
3205        tree_cons (NULL_TREE,                                            \
3206                   builtin_types[(int) ARG1],                            \
3207                   tree_cons (NULL_TREE,                                 \
3208                              builtin_types[(int) ARG2],                 \
3209                              tree_cons                                  \
3210                              (NULL_TREE,                                \
3211                               builtin_types[(int) ARG3],                \
3212                               tree_cons (NULL_TREE,                     \
3213                                          builtin_types[(int) ARG4],     \
3214                                          tree_cons (NULL_TREE,          \
3215                                               builtin_types[(int) ARG5],\
3216                                               void_list_node))))));
3217 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
3218                             ARG6)                                       \
3219   builtin_types[(int) ENUM]                                             \
3220     = build_function_type                                               \
3221       (builtin_types[(int) RETURN],                                     \
3222        tree_cons (NULL_TREE,                                            \
3223                   builtin_types[(int) ARG1],                            \
3224                   tree_cons (NULL_TREE,                                 \
3225                              builtin_types[(int) ARG2],                 \
3226                              tree_cons                                  \
3227                              (NULL_TREE,                                \
3228                               builtin_types[(int) ARG3],                \
3229                               tree_cons                                 \
3230                               (NULL_TREE,                               \
3231                                builtin_types[(int) ARG4],               \
3232                                tree_cons (NULL_TREE,                    \
3233                                          builtin_types[(int) ARG5],     \
3234                                          tree_cons (NULL_TREE,          \
3235                                               builtin_types[(int) ARG6],\
3236                                               void_list_node)))))));
3237 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN)                           \
3238   builtin_types[(int) ENUM]                                             \
3239     = build_function_type (builtin_types[(int) RETURN], NULL_TREE);
3240 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1)                      \
3241    builtin_types[(int) ENUM]                                             \
3242     = build_function_type (builtin_types[(int) RETURN],          \
3243                            tree_cons (NULL_TREE,                         \
3244                                       builtin_types[(int) ARG1],         \
3245                                       NULL_TREE));
3246
3247 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2)       \
3248    builtin_types[(int) ENUM]                                    \
3249     = build_function_type                                       \
3250       (builtin_types[(int) RETURN],                             \
3251        tree_cons (NULL_TREE,                                    \
3252                   builtin_types[(int) ARG1],                    \
3253                   tree_cons (NULL_TREE,                         \
3254                              builtin_types[(int) ARG2],         \
3255                              NULL_TREE)));
3256
3257 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3)         \
3258    builtin_types[(int) ENUM]                                            \
3259     = build_function_type                                               \
3260       (builtin_types[(int) RETURN],                                     \
3261        tree_cons (NULL_TREE,                                            \
3262                   builtin_types[(int) ARG1],                            \
3263                   tree_cons (NULL_TREE,                                 \
3264                              builtin_types[(int) ARG2],                 \
3265                              tree_cons (NULL_TREE,                      \
3266                                         builtin_types[(int) ARG3],      \
3267                                         NULL_TREE))));
3268
3269 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4)   \
3270    builtin_types[(int) ENUM]                                            \
3271     = build_function_type                                               \
3272       (builtin_types[(int) RETURN],                                     \
3273        tree_cons (NULL_TREE,                                            \
3274                   builtin_types[(int) ARG1],                            \
3275                   tree_cons (NULL_TREE,                                 \
3276                              builtin_types[(int) ARG2],                 \
3277                              tree_cons (NULL_TREE,                      \
3278                                         builtin_types[(int) ARG3],      \
3279                                         tree_cons (NULL_TREE,           \
3280                                               builtin_types[(int) ARG4],\
3281                                               NULL_TREE)))));
3282
3283 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4,   \
3284                                 ARG5)                                   \
3285    builtin_types[(int) ENUM]                                            \
3286     = build_function_type                                               \
3287       (builtin_types[(int) RETURN],                                     \
3288        tree_cons (NULL_TREE,                                            \
3289                   builtin_types[(int) ARG1],                            \
3290                   tree_cons (NULL_TREE,                                 \
3291                              builtin_types[(int) ARG2],                 \
3292                              tree_cons                                  \
3293                              (NULL_TREE,                                \
3294                               builtin_types[(int) ARG3],                \
3295                               tree_cons (NULL_TREE,                     \
3296                                         builtin_types[(int) ARG4],      \
3297                                         tree_cons (NULL_TREE,           \
3298                                               builtin_types[(int) ARG5],\
3299                                               NULL_TREE))))));
3300
3301 #define DEF_POINTER_TYPE(ENUM, TYPE)                    \
3302   builtin_types[(int) ENUM]                             \
3303     = build_pointer_type (builtin_types[(int) TYPE]);
3304 #include "builtin-types.def"
3305 #undef DEF_PRIMITIVE_TYPE
3306 #undef DEF_FUNCTION_TYPE_1
3307 #undef DEF_FUNCTION_TYPE_2
3308 #undef DEF_FUNCTION_TYPE_3
3309 #undef DEF_FUNCTION_TYPE_4
3310 #undef DEF_FUNCTION_TYPE_5
3311 #undef DEF_FUNCTION_TYPE_6
3312 #undef DEF_FUNCTION_TYPE_VAR_0
3313 #undef DEF_FUNCTION_TYPE_VAR_1
3314 #undef DEF_FUNCTION_TYPE_VAR_2
3315 #undef DEF_FUNCTION_TYPE_VAR_3
3316 #undef DEF_FUNCTION_TYPE_VAR_4
3317 #undef DEF_FUNCTION_TYPE_VAR_5
3318 #undef DEF_POINTER_TYPE
3319
3320   c_init_attributes ();
3321
3322 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
3323                     NONANSI_P, ATTRS, IMPLICIT, COND)                   \
3324   if (NAME && COND)                                                     \
3325     {                                                                   \
3326       tree decl;                                                        \
3327                                                                         \
3328       gcc_assert ((!BOTH_P && !FALLBACK_P)                              \
3329                   || !strncmp (NAME, "__builtin_",                      \
3330                                strlen ("__builtin_")));                 \
3331                                                                         \
3332       if (!BOTH_P)                                                      \
3333         decl = lang_hooks.builtin_function (NAME, builtin_types[TYPE],  \
3334                                  ENUM,                                  \
3335                                  CLASS,                                 \
3336                                  (FALLBACK_P                            \
3337                                   ? (NAME + strlen ("__builtin_"))      \
3338                                   : NULL),                              \
3339                                  built_in_attributes[(int) ATTRS]);     \
3340       else                                                              \
3341         decl = builtin_function_2 (NAME,                                \
3342                                    NAME + strlen ("__builtin_"),        \
3343                                    builtin_types[TYPE],                 \
3344                                    builtin_types[LIBTYPE],              \
3345                                    ENUM,                                \
3346                                    CLASS,                               \
3347                                    FALLBACK_P,                          \
3348                                    NONANSI_P,                           \
3349                                    built_in_attributes[(int) ATTRS]);   \
3350                                                                         \
3351       built_in_decls[(int) ENUM] = decl;                                \
3352       if (IMPLICIT)                                                     \
3353         implicit_built_in_decls[(int) ENUM] = decl;                     \
3354     }
3355 #include "builtins.def"
3356 #undef DEF_BUILTIN
3357
3358   build_common_builtin_nodes ();
3359
3360   targetm.init_builtins ();
3361   if (flag_mudflap)
3362     mudflap_init ();
3363
3364   main_identifier_node = get_identifier ("main");
3365
3366   /* Create the built-in __null node.  It is important that this is
3367      not shared.  */
3368   null_node = make_node (INTEGER_CST);
3369   TREE_TYPE (null_node) = c_common_type_for_size (POINTER_SIZE, 0);
3370 }
3371
3372 /* Look up the function in built_in_decls that corresponds to DECL
3373    and set ASMSPEC as its user assembler name.  DECL must be a
3374    function decl that declares a builtin.  */
3375
3376 void
3377 set_builtin_user_assembler_name (tree decl, const char *asmspec)
3378 {
3379   tree builtin;
3380   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
3381               && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
3382               && asmspec != 0);
3383
3384   builtin = built_in_decls [DECL_FUNCTION_CODE (decl)];
3385   set_user_assembler_name (builtin, asmspec);
3386   if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMCPY)
3387     init_block_move_fn (asmspec);
3388   else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMSET)
3389     init_block_clear_fn (asmspec);
3390 }
3391
3392 tree
3393 build_va_arg (tree expr, tree type)
3394 {
3395   return build1 (VA_ARG_EXPR, type, expr);
3396 }
3397
3398
3399 /* Linked list of disabled built-in functions.  */
3400
3401 typedef struct disabled_builtin
3402 {
3403   const char *name;
3404   struct disabled_builtin *next;
3405 } disabled_builtin;
3406 static disabled_builtin *disabled_builtins = NULL;
3407
3408 static bool builtin_function_disabled_p (const char *);
3409
3410 /* Disable a built-in function specified by -fno-builtin-NAME.  If NAME
3411    begins with "__builtin_", give an error.  */
3412
3413 void
3414 disable_builtin_function (const char *name)
3415 {
3416   if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
3417     error ("cannot disable built-in function %qs", name);
3418   else
3419     {
3420       disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin);
3421       new_disabled_builtin->name = name;
3422       new_disabled_builtin->next = disabled_builtins;
3423       disabled_builtins = new_disabled_builtin;
3424     }
3425 }
3426
3427
3428 /* Return true if the built-in function NAME has been disabled, false
3429    otherwise.  */
3430
3431 static bool
3432 builtin_function_disabled_p (const char *name)
3433 {
3434   disabled_builtin *p;
3435   for (p = disabled_builtins; p != NULL; p = p->next)
3436     {
3437       if (strcmp (name, p->name) == 0)
3438         return true;
3439     }
3440   return false;
3441 }
3442
3443
3444 /* Possibly define a builtin function with one or two names.  BUILTIN_NAME
3445    is an __builtin_-prefixed name; NAME is the ordinary name; one or both
3446    of these may be NULL (though both being NULL is useless).
3447    BUILTIN_TYPE is the type of the __builtin_-prefixed function;
3448    TYPE is the type of the function with the ordinary name.  These
3449    may differ if the ordinary name is declared with a looser type to avoid
3450    conflicts with headers.  FUNCTION_CODE and CL are as for
3451    builtin_function.  If LIBRARY_NAME_P is nonzero, NAME is passed as
3452    the LIBRARY_NAME parameter to builtin_function when declaring BUILTIN_NAME.
3453    If NONANSI_P is true, the name NAME is treated as a non-ANSI name;
3454    ATTRS is the tree list representing the builtin's function attributes.
3455    Returns the declaration of BUILTIN_NAME, if any, otherwise
3456    the declaration of NAME.  Does not declare NAME if flag_no_builtin,
3457    or if NONANSI_P and flag_no_nonansi_builtin.  */
3458
3459 static tree
3460 builtin_function_2 (const char *builtin_name, const char *name,
3461                     tree builtin_type, tree type,
3462                     enum built_in_function function_code,
3463                     enum built_in_class cl, int library_name_p,
3464                     bool nonansi_p, tree attrs)
3465 {
3466   tree bdecl = NULL_TREE;
3467   tree decl = NULL_TREE;
3468
3469   if (builtin_name != 0)
3470     bdecl = lang_hooks.builtin_function (builtin_name, builtin_type,
3471                                          function_code, cl,
3472                                          library_name_p ? name : NULL, attrs);
3473
3474   if (name != 0 && !flag_no_builtin && !builtin_function_disabled_p (name)
3475       && !(nonansi_p && flag_no_nonansi_builtin))
3476     decl = lang_hooks.builtin_function (name, type, function_code, cl,
3477                                         NULL, attrs);
3478
3479   return (bdecl != 0 ? bdecl : decl);
3480 }
3481 \f
3482 /* Nonzero if the type T promotes to int.  This is (nearly) the
3483    integral promotions defined in ISO C99 6.3.1.1/2.  */
3484
3485 bool
3486 c_promoting_integer_type_p (tree t)
3487 {
3488   switch (TREE_CODE (t))
3489     {
3490     case INTEGER_TYPE:
3491       return (TYPE_MAIN_VARIANT (t) == char_type_node
3492               || TYPE_MAIN_VARIANT (t) == signed_char_type_node
3493               || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node
3494               || TYPE_MAIN_VARIANT (t) == short_integer_type_node
3495               || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node
3496               || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node));
3497
3498     case ENUMERAL_TYPE:
3499       /* ??? Technically all enumerations not larger than an int
3500          promote to an int.  But this is used along code paths
3501          that only want to notice a size change.  */
3502       return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node);
3503
3504     case BOOLEAN_TYPE:
3505       return 1;
3506
3507     default:
3508       return 0;
3509     }
3510 }
3511
3512 /* Return 1 if PARMS specifies a fixed number of parameters
3513    and none of their types is affected by default promotions.  */
3514
3515 int
3516 self_promoting_args_p (tree parms)
3517 {
3518   tree t;
3519   for (t = parms; t; t = TREE_CHAIN (t))
3520     {
3521       tree type = TREE_VALUE (t);
3522
3523       if (TREE_CHAIN (t) == 0 && type != void_type_node)
3524         return 0;
3525
3526       if (type == 0)
3527         return 0;
3528
3529       if (TYPE_MAIN_VARIANT (type) == float_type_node)
3530         return 0;
3531
3532       if (c_promoting_integer_type_p (type))
3533         return 0;
3534     }
3535   return 1;
3536 }
3537
3538 /* Recursively examines the array elements of TYPE, until a non-array
3539    element type is found.  */
3540
3541 tree
3542 strip_array_types (tree type)
3543 {
3544   while (TREE_CODE (type) == ARRAY_TYPE)
3545     type = TREE_TYPE (type);
3546
3547   return type;
3548 }
3549
3550 /* Recursively remove any '*' or '&' operator from TYPE.  */
3551 tree
3552 strip_pointer_operator (tree t)
3553 {
3554   while (POINTER_TYPE_P (t))
3555     t = TREE_TYPE (t);
3556   return t;
3557 }
3558
3559 /* Used to compare case labels.  K1 and K2 are actually tree nodes
3560    representing case labels, or NULL_TREE for a `default' label.
3561    Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
3562    K2, and 0 if K1 and K2 are equal.  */
3563
3564 int
3565 case_compare (splay_tree_key k1, splay_tree_key k2)
3566 {
3567   /* Consider a NULL key (such as arises with a `default' label) to be
3568      smaller than anything else.  */
3569   if (!k1)
3570     return k2 ? -1 : 0;
3571   else if (!k2)
3572     return k1 ? 1 : 0;
3573
3574   return tree_int_cst_compare ((tree) k1, (tree) k2);
3575 }
3576
3577 /* Process a case label for the range LOW_VALUE ... HIGH_VALUE.  If
3578    LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is
3579    actually a `default' label.  If only HIGH_VALUE is NULL_TREE, then
3580    case label was declared using the usual C/C++ syntax, rather than
3581    the GNU case range extension.  CASES is a tree containing all the
3582    case ranges processed so far; COND is the condition for the
3583    switch-statement itself.  Returns the CASE_LABEL_EXPR created, or
3584    ERROR_MARK_NODE if no CASE_LABEL_EXPR is created.  */
3585
3586 tree
3587 c_add_case_label (splay_tree cases, tree cond, tree orig_type,
3588                   tree low_value, tree high_value)
3589 {
3590   tree type;
3591   tree label;
3592   tree case_label;
3593   splay_tree_node node;
3594
3595   /* Create the LABEL_DECL itself.  */
3596   label = create_artificial_label ();
3597
3598   /* If there was an error processing the switch condition, bail now
3599      before we get more confused.  */
3600   if (!cond || cond == error_mark_node)
3601     goto error_out;
3602
3603   if ((low_value && TREE_TYPE (low_value)
3604        && POINTER_TYPE_P (TREE_TYPE (low_value)))
3605       || (high_value && TREE_TYPE (high_value)
3606           && POINTER_TYPE_P (TREE_TYPE (high_value))))
3607     {
3608       error ("pointers are not permitted as case values");
3609       goto error_out;
3610     }
3611
3612   /* Case ranges are a GNU extension.  */
3613   if (high_value && pedantic)
3614     pedwarn ("range expressions in switch statements are non-standard");
3615
3616   type = TREE_TYPE (cond);
3617   if (low_value)
3618     {
3619       low_value = check_case_value (low_value);
3620       low_value = convert_and_check (type, low_value);
3621     }
3622   if (high_value)
3623     {
3624       high_value = check_case_value (high_value);
3625       high_value = convert_and_check (type, high_value);
3626     }
3627
3628   /* If an error has occurred, bail out now.  */
3629   if (low_value == error_mark_node || high_value == error_mark_node)
3630     goto error_out;
3631
3632   /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
3633      really a case range, even though it was written that way.  Remove
3634      the HIGH_VALUE to simplify later processing.  */
3635   if (tree_int_cst_equal (low_value, high_value))
3636     high_value = NULL_TREE;
3637   if (low_value && high_value
3638       && !tree_int_cst_lt (low_value, high_value))
3639     warning (0, "empty range specified");
3640
3641   /* See if the case is in range of the type of the original testing
3642      expression.  If both low_value and high_value are out of range,
3643      don't insert the case label and return NULL_TREE.  */
3644   if (low_value
3645       && !check_case_bounds (type, orig_type,
3646                              &low_value, high_value ? &high_value : NULL))
3647     return NULL_TREE;
3648
3649   /* Look up the LOW_VALUE in the table of case labels we already
3650      have.  */
3651   node = splay_tree_lookup (cases, (splay_tree_key) low_value);
3652   /* If there was not an exact match, check for overlapping ranges.
3653      There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
3654      that's a `default' label and the only overlap is an exact match.  */
3655   if (!node && (low_value || high_value))
3656     {
3657       splay_tree_node low_bound;
3658       splay_tree_node high_bound;
3659
3660       /* Even though there wasn't an exact match, there might be an
3661          overlap between this case range and another case range.
3662          Since we've (inductively) not allowed any overlapping case
3663          ranges, we simply need to find the greatest low case label
3664          that is smaller that LOW_VALUE, and the smallest low case
3665          label that is greater than LOW_VALUE.  If there is an overlap
3666          it will occur in one of these two ranges.  */
3667       low_bound = splay_tree_predecessor (cases,
3668                                           (splay_tree_key) low_value);
3669       high_bound = splay_tree_successor (cases,
3670                                          (splay_tree_key) low_value);
3671
3672       /* Check to see if the LOW_BOUND overlaps.  It is smaller than
3673          the LOW_VALUE, so there is no need to check unless the
3674          LOW_BOUND is in fact itself a case range.  */
3675       if (low_bound
3676           && CASE_HIGH ((tree) low_bound->value)
3677           && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
3678                                     low_value) >= 0)
3679         node = low_bound;
3680       /* Check to see if the HIGH_BOUND overlaps.  The low end of that
3681          range is bigger than the low end of the current range, so we
3682          are only interested if the current range is a real range, and
3683          not an ordinary case label.  */
3684       else if (high_bound
3685                && high_value
3686                && (tree_int_cst_compare ((tree) high_bound->key,
3687                                          high_value)
3688                    <= 0))
3689         node = high_bound;
3690     }
3691   /* If there was an overlap, issue an error.  */
3692   if (node)
3693     {
3694       tree duplicate = CASE_LABEL ((tree) node->value);
3695
3696       if (high_value)
3697         {
3698           error ("duplicate (or overlapping) case value");
3699           error ("%Jthis is the first entry overlapping that value", duplicate);
3700         }
3701       else if (low_value)
3702         {
3703           error ("duplicate case value") ;
3704           error ("%Jpreviously used here", duplicate);
3705         }
3706       else
3707         {
3708           error ("multiple default labels in one switch");
3709           error ("%Jthis is the first default label", duplicate);
3710         }
3711       goto error_out;
3712     }
3713
3714   /* Add a CASE_LABEL to the statement-tree.  */
3715   case_label = add_stmt (build_case_label (low_value, high_value, label));
3716   /* Register this case label in the splay tree.  */
3717   splay_tree_insert (cases,
3718                      (splay_tree_key) low_value,
3719                      (splay_tree_value) case_label);
3720
3721   return case_label;
3722
3723  error_out:
3724   /* Add a label so that the back-end doesn't think that the beginning of
3725      the switch is unreachable.  Note that we do not add a case label, as
3726      that just leads to duplicates and thence to failure later on.  */
3727   if (!cases->root)
3728     {
3729       tree t = create_artificial_label ();
3730       add_stmt (build_stmt (LABEL_EXPR, t));
3731     }
3732   return error_mark_node;
3733 }
3734
3735 /* Subroutines of c_do_switch_warnings, called via splay_tree_foreach.
3736    Used to verify that case values match up with enumerator values.  */
3737
3738 static void
3739 match_case_to_enum_1 (tree key, tree type, tree label)
3740 {
3741   char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1];
3742
3743   /* ??? Not working too hard to print the double-word value.
3744      Should perhaps be done with %lwd in the diagnostic routines?  */
3745   if (TREE_INT_CST_HIGH (key) == 0)
3746     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED,
3747               TREE_INT_CST_LOW (key));
3748   else if (!TYPE_UNSIGNED (type)
3749            && TREE_INT_CST_HIGH (key) == -1
3750            && TREE_INT_CST_LOW (key) != 0)
3751     snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED,
3752               -TREE_INT_CST_LOW (key));
3753   else
3754     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX,
3755               TREE_INT_CST_HIGH (key), TREE_INT_CST_LOW (key));
3756
3757   if (TYPE_NAME (type) == 0)
3758     warning (0, "%Jcase value %qs not in enumerated type",
3759              CASE_LABEL (label), buf);
3760   else
3761     warning (0, "%Jcase value %qs not in enumerated type %qT",
3762              CASE_LABEL (label), buf, type);
3763 }
3764
3765 static int
3766 match_case_to_enum (splay_tree_node node, void *data)
3767 {
3768   tree label = (tree) node->value;
3769   tree type = (tree) data;
3770
3771   /* Skip default case.  */
3772   if (!CASE_LOW (label))
3773     return 0;
3774
3775   /* If TREE_ADDRESSABLE is not set, that means CASE_LOW did not appear
3776      when we did our enum->case scan.  Reset our scratch bit after.  */
3777   if (!TREE_ADDRESSABLE (label))
3778     match_case_to_enum_1 (CASE_LOW (label), type, label);
3779   else
3780     TREE_ADDRESSABLE (label) = 0;
3781
3782   /* If CASE_HIGH is non-null, we have a range.  Here we must search.
3783      Note that the old code in stmt.c did not check for the values in
3784      the range either, just the endpoints.  */
3785   if (CASE_HIGH (label))
3786     {
3787       tree chain, key = CASE_HIGH (label);
3788
3789       for (chain = TYPE_VALUES (type);
3790            chain && !tree_int_cst_equal (key, TREE_VALUE (chain));
3791            chain = TREE_CHAIN (chain))
3792         continue;
3793       if (!chain)
3794         match_case_to_enum_1 (key, type, label);
3795     }
3796
3797   return 0;
3798 }
3799
3800 /* Handle -Wswitch*.  Called from the front end after parsing the
3801    switch construct.  */
3802 /* ??? Should probably be somewhere generic, since other languages
3803    besides C and C++ would want this.  At the moment, however, C/C++
3804    are the only tree-ssa languages that support enumerations at all,
3805    so the point is moot.  */
3806
3807 void
3808 c_do_switch_warnings (splay_tree cases, location_t switch_location,
3809                       tree type, tree cond)
3810 {
3811   splay_tree_node default_node;
3812
3813   if (!warn_switch && !warn_switch_enum && !warn_switch_default)
3814     return;
3815
3816   default_node = splay_tree_lookup (cases, (splay_tree_key) NULL);
3817   if (!default_node)
3818     warning (OPT_Wswitch_default, "%Hswitch missing default case",
3819              &switch_location);
3820
3821   /* If the switch expression was an enumerated type, check that
3822      exactly all enumeration literals are covered by the cases.
3823      The check is made when -Wswitch was specified and there is no
3824      default case, or when -Wswitch-enum was specified.  */
3825   if (((warn_switch && !default_node) || warn_switch_enum)
3826       && type && TREE_CODE (type) == ENUMERAL_TYPE
3827       && TREE_CODE (cond) != INTEGER_CST)
3828     {
3829       tree chain;
3830
3831       /* The time complexity here is O(N*lg(N)) worst case, but for the
3832          common case of monotonically increasing enumerators, it is
3833          O(N), since the nature of the splay tree will keep the next
3834          element adjacent to the root at all times.  */
3835
3836       for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain))
3837         {
3838           splay_tree_node node
3839             = splay_tree_lookup (cases, (splay_tree_key) TREE_VALUE (chain));
3840
3841           if (node)
3842             {
3843               /* Mark the CASE_LOW part of the case entry as seen, so
3844                  that we save time later.  Choose TREE_ADDRESSABLE
3845                  randomly as a bit that won't have been set to-date.  */
3846               tree label = (tree) node->value;
3847               TREE_ADDRESSABLE (label) = 1;
3848             }
3849           else
3850             {
3851               /* Warn if there are enumerators that don't correspond to
3852                  case expressions.  */
3853               warning (0, "%Henumeration value %qE not handled in switch",
3854                        &switch_location, TREE_PURPOSE (chain));
3855             }
3856         }
3857
3858       /* Warn if there are case expressions that don't correspond to
3859          enumerators.  This can occur since C and C++ don't enforce
3860          type-checking of assignments to enumeration variables.
3861
3862          The time complexity here is O(N**2) worst case, since we've
3863          not sorted the enumeration values.  However, in the absence
3864          of case ranges this is O(N), since all single cases that
3865          corresponded to enumerations have been marked above.  */
3866
3867       splay_tree_foreach (cases, match_case_to_enum, type);
3868     }
3869 }
3870
3871 /* Finish an expression taking the address of LABEL (an
3872    IDENTIFIER_NODE).  Returns an expression for the address.  */
3873
3874 tree
3875 finish_label_address_expr (tree label)
3876 {
3877   tree result;
3878
3879   if (pedantic)
3880     pedwarn ("taking the address of a label is non-standard");
3881
3882   if (label == error_mark_node)
3883     return error_mark_node;
3884
3885   label = lookup_label (label);
3886   if (label == NULL_TREE)
3887     result = null_pointer_node;
3888   else
3889     {
3890       TREE_USED (label) = 1;
3891       result = build1 (ADDR_EXPR, ptr_type_node, label);
3892       /* The current function in not necessarily uninlinable.
3893          Computed gotos are incompatible with inlining, but the value
3894          here could be used only in a diagnostic, for example.  */
3895     }
3896
3897   return result;
3898 }
3899
3900 /* Hook used by expand_expr to expand language-specific tree codes.  */
3901 /* The only things that should go here are bits needed to expand
3902    constant initializers.  Everything else should be handled by the
3903    gimplification routines.  */
3904
3905 rtx
3906 c_expand_expr (tree exp, rtx target, enum machine_mode tmode,
3907                int modifier /* Actually enum_modifier.  */,
3908                rtx *alt_rtl)
3909 {
3910   switch (TREE_CODE (exp))
3911     {
3912     case COMPOUND_LITERAL_EXPR:
3913       {
3914         /* Initialize the anonymous variable declared in the compound
3915            literal, then return the variable.  */
3916         tree decl = COMPOUND_LITERAL_EXPR_DECL (exp);
3917         emit_local_var (decl);
3918         return expand_expr_real (decl, target, tmode, modifier, alt_rtl);
3919       }
3920
3921     default:
3922       gcc_unreachable ();
3923     }
3924 }
3925
3926 /* Hook used by staticp to handle language-specific tree codes.  */
3927
3928 tree
3929 c_staticp (tree exp)
3930 {
3931   return (TREE_CODE (exp) == COMPOUND_LITERAL_EXPR
3932           && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp))
3933           ? exp : NULL);
3934 }
3935 \f
3936
3937 /* Given a boolean expression ARG, return a tree representing an increment
3938    or decrement (as indicated by CODE) of ARG.  The front end must check for
3939    invalid cases (e.g., decrement in C++).  */
3940 tree
3941 boolean_increment (enum tree_code code, tree arg)
3942 {
3943   tree val;
3944   tree true_res = boolean_true_node;
3945
3946   arg = stabilize_reference (arg);
3947   switch (code)
3948     {
3949     case PREINCREMENT_EXPR:
3950       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
3951       break;
3952     case POSTINCREMENT_EXPR:
3953       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
3954       arg = save_expr (arg);
3955       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
3956       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
3957       break;
3958     case PREDECREMENT_EXPR:
3959       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
3960                     invert_truthvalue (arg));
3961       break;
3962     case POSTDECREMENT_EXPR:
3963       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
3964                     invert_truthvalue (arg));
3965       arg = save_expr (arg);
3966       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
3967       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
3968       break;
3969     default:
3970       gcc_unreachable ();
3971     }
3972   TREE_SIDE_EFFECTS (val) = 1;
3973   return val;
3974 }
3975 \f
3976 /* Built-in macros for stddef.h, that require macros defined in this
3977    file.  */
3978 void
3979 c_stddef_cpp_builtins(void)
3980 {
3981   builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0);
3982   builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0);
3983   builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0);
3984   builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0);
3985   builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0);
3986   builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0);
3987 }
3988
3989 static void
3990 c_init_attributes (void)
3991 {
3992   /* Fill in the built_in_attributes array.  */
3993 #define DEF_ATTR_NULL_TREE(ENUM)                                \
3994   built_in_attributes[(int) ENUM] = NULL_TREE;
3995 #define DEF_ATTR_INT(ENUM, VALUE)                               \
3996   built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
3997 #define DEF_ATTR_IDENT(ENUM, STRING)                            \
3998   built_in_attributes[(int) ENUM] = get_identifier (STRING);
3999 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
4000   built_in_attributes[(int) ENUM]                       \
4001     = tree_cons (built_in_attributes[(int) PURPOSE],    \
4002                  built_in_attributes[(int) VALUE],      \
4003                  built_in_attributes[(int) CHAIN]);
4004 #include "builtin-attrs.def"
4005 #undef DEF_ATTR_NULL_TREE
4006 #undef DEF_ATTR_INT
4007 #undef DEF_ATTR_IDENT
4008 #undef DEF_ATTR_TREE_LIST
4009 }
4010
4011 /* Attribute handlers common to C front ends.  */
4012
4013 /* Handle a "packed" attribute; arguments as in
4014    struct attribute_spec.handler.  */
4015
4016 static tree
4017 handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4018                          int flags, bool *no_add_attrs)
4019 {
4020   if (TYPE_P (*node))
4021     {
4022       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4023         *node = build_variant_type_copy (*node);
4024       TYPE_PACKED (*node) = 1;
4025       if (TYPE_MAIN_VARIANT (*node) == *node)
4026         {
4027           /* If it is the main variant, then pack the other variants
4028              too. This happens in,
4029
4030              struct Foo {
4031                struct Foo const *ptr; // creates a variant w/o packed flag
4032                } __ attribute__((packed)); // packs it now.
4033           */
4034           tree probe;
4035
4036           for (probe = *node; probe; probe = TYPE_NEXT_VARIANT (probe))
4037             TYPE_PACKED (probe) = 1;
4038         }
4039
4040     }
4041   else if (TREE_CODE (*node) == FIELD_DECL)
4042     DECL_PACKED (*node) = 1;
4043   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
4044      used for DECL_REGISTER.  It wouldn't mean anything anyway.
4045      We can't set DECL_PACKED on the type of a TYPE_DECL, because
4046      that changes what the typedef is typing.  */
4047   else
4048     {
4049       warning (OPT_Wattributes, "%qE attribute ignored", name);
4050       *no_add_attrs = true;
4051     }
4052
4053   return NULL_TREE;
4054 }
4055
4056 /* Handle a "nocommon" attribute; arguments as in
4057    struct attribute_spec.handler.  */
4058
4059 static tree
4060 handle_nocommon_attribute (tree *node, tree name,
4061                            tree ARG_UNUSED (args),
4062                            int ARG_UNUSED (flags), bool *no_add_attrs)
4063 {
4064   if (TREE_CODE (*node) == VAR_DECL)
4065     DECL_COMMON (*node) = 0;
4066   else
4067     {
4068       warning (OPT_Wattributes, "%qE attribute ignored", name);
4069       *no_add_attrs = true;
4070     }
4071
4072   return NULL_TREE;
4073 }
4074
4075 /* Handle a "common" attribute; arguments as in
4076    struct attribute_spec.handler.  */
4077
4078 static tree
4079 handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4080                          int ARG_UNUSED (flags), bool *no_add_attrs)
4081 {
4082   if (TREE_CODE (*node) == VAR_DECL)
4083     DECL_COMMON (*node) = 1;
4084   else
4085     {
4086       warning (OPT_Wattributes, "%qE attribute ignored", name);
4087       *no_add_attrs = true;
4088     }
4089
4090   return NULL_TREE;
4091 }
4092
4093 /* Handle a "noreturn" attribute; arguments as in
4094    struct attribute_spec.handler.  */
4095
4096 static tree
4097 handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4098                            int ARG_UNUSED (flags), bool *no_add_attrs)
4099 {
4100   tree type = TREE_TYPE (*node);
4101
4102   /* See FIXME comment in c_common_attribute_table.  */
4103   if (TREE_CODE (*node) == FUNCTION_DECL)
4104     TREE_THIS_VOLATILE (*node) = 1;
4105   else if (TREE_CODE (type) == POINTER_TYPE
4106            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4107     TREE_TYPE (*node)
4108       = build_pointer_type
4109         (build_type_variant (TREE_TYPE (type),
4110                              TYPE_READONLY (TREE_TYPE (type)), 1));
4111   else
4112     {
4113       warning (OPT_Wattributes, "%qE attribute ignored", name);
4114       *no_add_attrs = true;
4115     }
4116
4117   return NULL_TREE;
4118 }
4119
4120 /* Handle a "noinline" attribute; arguments as in
4121    struct attribute_spec.handler.  */
4122
4123 static tree
4124 handle_noinline_attribute (tree *node, tree name,
4125                            tree ARG_UNUSED (args),
4126                            int ARG_UNUSED (flags), bool *no_add_attrs)
4127 {
4128   if (TREE_CODE (*node) == FUNCTION_DECL)
4129     DECL_UNINLINABLE (*node) = 1;
4130   else
4131     {
4132       warning (OPT_Wattributes, "%qE attribute ignored", name);
4133       *no_add_attrs = true;
4134     }
4135
4136   return NULL_TREE;
4137 }
4138
4139 /* Handle a "always_inline" attribute; arguments as in
4140    struct attribute_spec.handler.  */
4141
4142 static tree
4143 handle_always_inline_attribute (tree *node, tree name,
4144                                 tree ARG_UNUSED (args),
4145                                 int ARG_UNUSED (flags),
4146                                 bool *no_add_attrs)
4147 {
4148   if (TREE_CODE (*node) == FUNCTION_DECL)
4149     {
4150       /* Do nothing else, just set the attribute.  We'll get at
4151          it later with lookup_attribute.  */
4152     }
4153   else
4154     {
4155       warning (OPT_Wattributes, "%qE attribute ignored", name);
4156       *no_add_attrs = true;
4157     }
4158
4159   return NULL_TREE;
4160 }
4161
4162 /* Handle a "used" attribute; arguments as in
4163    struct attribute_spec.handler.  */
4164
4165 static tree
4166 handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
4167                        int ARG_UNUSED (flags), bool *no_add_attrs)
4168 {
4169   tree node = *pnode;
4170
4171   if (TREE_CODE (node) == FUNCTION_DECL
4172       || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node)))
4173     {
4174       TREE_USED (node) = 1;
4175       DECL_PRESERVE_P (node) = 1;
4176     }
4177   else
4178     {
4179       warning (OPT_Wattributes, "%qE attribute ignored", name);
4180       *no_add_attrs = true;
4181     }
4182
4183   return NULL_TREE;
4184 }
4185
4186 /* Handle a "unused" attribute; arguments as in
4187    struct attribute_spec.handler.  */
4188
4189 static tree
4190 handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4191                          int flags, bool *no_add_attrs)
4192 {
4193   if (DECL_P (*node))
4194     {
4195       tree decl = *node;
4196
4197       if (TREE_CODE (decl) == PARM_DECL
4198           || TREE_CODE (decl) == VAR_DECL
4199           || TREE_CODE (decl) == FUNCTION_DECL
4200           || TREE_CODE (decl) == LABEL_DECL
4201           || TREE_CODE (decl) == TYPE_DECL)
4202         TREE_USED (decl) = 1;
4203       else
4204         {
4205           warning (OPT_Wattributes, "%qE attribute ignored", name);
4206           *no_add_attrs = true;
4207         }
4208     }
4209   else
4210     {
4211       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4212         *node = build_variant_type_copy (*node);
4213       TREE_USED (*node) = 1;
4214     }
4215
4216   return NULL_TREE;
4217 }
4218
4219 /* Handle a "externally_visible" attribute; arguments as in
4220    struct attribute_spec.handler.  */
4221
4222 static tree
4223 handle_externally_visible_attribute (tree *pnode, tree name,
4224                                      tree ARG_UNUSED (args),
4225                                      int ARG_UNUSED (flags),
4226                                      bool *no_add_attrs)
4227 {
4228   tree node = *pnode;
4229
4230   if ((!TREE_STATIC (node) && TREE_CODE (node) != FUNCTION_DECL)
4231       || !TREE_PUBLIC (node))
4232     {
4233       warning (OPT_Wattributes,
4234                "%qE attribute have effect only on public objects", name);
4235       *no_add_attrs = true;
4236     }
4237   else if (TREE_CODE (node) == FUNCTION_DECL)
4238     {
4239       struct cgraph_node *n = cgraph_node (node);
4240       n->local.externally_visible = true;
4241       if (n->local.finalized)
4242         cgraph_mark_needed_node (n);
4243     }
4244   else if (TREE_CODE (node) == VAR_DECL)
4245     {
4246       struct cgraph_varpool_node *n = cgraph_varpool_node (node);
4247       n->externally_visible = true;
4248       if (n->finalized)
4249         cgraph_varpool_mark_needed_node (n);
4250     }
4251   else
4252     {
4253       warning (OPT_Wattributes, "%qE attribute ignored", name);
4254       *no_add_attrs = true;
4255     }
4256
4257   return NULL_TREE;
4258 }
4259
4260 /* Handle a "const" attribute; arguments as in
4261    struct attribute_spec.handler.  */
4262
4263 static tree
4264 handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4265                         int ARG_UNUSED (flags), bool *no_add_attrs)
4266 {
4267   tree type = TREE_TYPE (*node);
4268
4269   /* See FIXME comment on noreturn in c_common_attribute_table.  */
4270   if (TREE_CODE (*node) == FUNCTION_DECL)
4271     TREE_READONLY (*node) = 1;
4272   else if (TREE_CODE (type) == POINTER_TYPE
4273            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4274     TREE_TYPE (*node)
4275       = build_pointer_type
4276         (build_type_variant (TREE_TYPE (type), 1,
4277                              TREE_THIS_VOLATILE (TREE_TYPE (type))));
4278   else
4279     {
4280       warning (OPT_Wattributes, "%qE attribute ignored", name);
4281       *no_add_attrs = true;
4282     }
4283
4284   return NULL_TREE;
4285 }
4286
4287 /* Handle a "transparent_union" attribute; arguments as in
4288    struct attribute_spec.handler.  */
4289
4290 static tree
4291 handle_transparent_union_attribute (tree *node, tree name,
4292                                     tree ARG_UNUSED (args), int flags,
4293                                     bool *no_add_attrs)
4294 {
4295   tree decl = NULL_TREE;
4296   tree *type = NULL;
4297   int is_type = 0;
4298
4299   if (DECL_P (*node))
4300     {
4301       decl = *node;
4302       type = &TREE_TYPE (decl);
4303       is_type = TREE_CODE (*node) == TYPE_DECL;
4304     }
4305   else if (TYPE_P (*node))
4306     type = node, is_type = 1;
4307
4308   if (is_type
4309       && TREE_CODE (*type) == UNION_TYPE
4310       && (decl == 0
4311           || (TYPE_FIELDS (*type) != 0
4312               && TYPE_MODE (*type) == DECL_MODE (TYPE_FIELDS (*type)))))
4313     {
4314       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4315         *type = build_variant_type_copy (*type);
4316       TYPE_TRANSPARENT_UNION (*type) = 1;
4317     }
4318   else if (decl != 0 && TREE_CODE (decl) == PARM_DECL
4319            && TREE_CODE (*type) == UNION_TYPE
4320            && TYPE_MODE (*type) == DECL_MODE (TYPE_FIELDS (*type)))
4321     DECL_TRANSPARENT_UNION (decl) = 1;
4322   else
4323     {
4324       warning (OPT_Wattributes, "%qE attribute ignored", name);
4325       *no_add_attrs = true;
4326     }
4327
4328   return NULL_TREE;
4329 }
4330
4331 /* Handle a "constructor" attribute; arguments as in
4332    struct attribute_spec.handler.  */
4333
4334 static tree
4335 handle_constructor_attribute (tree *node, tree name,
4336                               tree ARG_UNUSED (args),
4337                               int ARG_UNUSED (flags),
4338                               bool *no_add_attrs)
4339 {
4340   tree decl = *node;
4341   tree type = TREE_TYPE (decl);
4342
4343   if (TREE_CODE (decl) == FUNCTION_DECL
4344       && TREE_CODE (type) == FUNCTION_TYPE
4345       && decl_function_context (decl) == 0)
4346     {
4347       DECL_STATIC_CONSTRUCTOR (decl) = 1;
4348       TREE_USED (decl) = 1;
4349     }
4350   else
4351     {
4352       warning (OPT_Wattributes, "%qE attribute ignored", name);
4353       *no_add_attrs = true;
4354     }
4355
4356   return NULL_TREE;
4357 }
4358
4359 /* Handle a "destructor" attribute; arguments as in
4360    struct attribute_spec.handler.  */
4361
4362 static tree
4363 handle_destructor_attribute (tree *node, tree name,
4364                              tree ARG_UNUSED (args),
4365                              int ARG_UNUSED (flags),
4366                              bool *no_add_attrs)
4367 {
4368   tree decl = *node;
4369   tree type = TREE_TYPE (decl);
4370
4371   if (TREE_CODE (decl) == FUNCTION_DECL
4372       && TREE_CODE (type) == FUNCTION_TYPE
4373       && decl_function_context (decl) == 0)
4374     {
4375       DECL_STATIC_DESTRUCTOR (decl) = 1;
4376       TREE_USED (decl) = 1;
4377     }
4378   else
4379     {
4380       warning (OPT_Wattributes, "%qE attribute ignored", name);
4381       *no_add_attrs = true;
4382     }
4383
4384   return NULL_TREE;
4385 }
4386
4387 /* Handle a "mode" attribute; arguments as in
4388    struct attribute_spec.handler.  */
4389
4390 static tree
4391 handle_mode_attribute (tree *node, tree name, tree args,
4392                        int ARG_UNUSED (flags), bool *no_add_attrs)
4393 {
4394   tree type = *node;
4395
4396   *no_add_attrs = true;
4397
4398   if (TREE_CODE (TREE_VALUE (args)) != IDENTIFIER_NODE)
4399     warning (OPT_Wattributes, "%qE attribute ignored", name);
4400   else
4401     {
4402       int j;
4403       const char *p = IDENTIFIER_POINTER (TREE_VALUE (args));
4404       int len = strlen (p);
4405       enum machine_mode mode = VOIDmode;
4406       tree typefm;
4407       bool valid_mode;
4408
4409       if (len > 4 && p[0] == '_' && p[1] == '_'
4410           && p[len - 1] == '_' && p[len - 2] == '_')
4411         {
4412           char *newp = (char *) alloca (len - 1);
4413
4414           strcpy (newp, &p[2]);
4415           newp[len - 4] = '\0';
4416           p = newp;
4417         }
4418
4419       /* Change this type to have a type with the specified mode.
4420          First check for the special modes.  */
4421       if (!strcmp (p, "byte"))
4422         mode = byte_mode;
4423       else if (!strcmp (p, "word"))
4424         mode = word_mode;
4425       else if (!strcmp (p, "pointer"))
4426         mode = ptr_mode;
4427       else
4428         for (j = 0; j < NUM_MACHINE_MODES; j++)
4429           if (!strcmp (p, GET_MODE_NAME (j)))
4430             {
4431               mode = (enum machine_mode) j;
4432               break;
4433             }
4434
4435       if (mode == VOIDmode)
4436         {
4437           error ("unknown machine mode %qs", p);
4438           return NULL_TREE;
4439         }
4440
4441       valid_mode = false;
4442       switch (GET_MODE_CLASS (mode))
4443         {
4444         case MODE_INT:
4445         case MODE_PARTIAL_INT:
4446         case MODE_FLOAT:
4447           valid_mode = targetm.scalar_mode_supported_p (mode);
4448           break;
4449
4450         case MODE_COMPLEX_INT:
4451         case MODE_COMPLEX_FLOAT:
4452           valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode));
4453           break;
4454
4455         case MODE_VECTOR_INT:
4456         case MODE_VECTOR_FLOAT:
4457           warning (OPT_Wattributes, "specifying vector types with "
4458                    "__attribute__ ((mode)) is deprecated");
4459           warning (OPT_Wattributes,
4460                    "use __attribute__ ((vector_size)) instead");
4461           valid_mode = vector_mode_valid_p (mode);
4462           break;
4463
4464         default:
4465           break;
4466         }
4467       if (!valid_mode)
4468         {
4469           error ("unable to emulate %qs", p);
4470           return NULL_TREE;
4471         }
4472
4473       if (POINTER_TYPE_P (type))
4474         {
4475           tree (*fn)(tree, enum machine_mode, bool);
4476
4477           if (!targetm.valid_pointer_mode (mode))
4478             {
4479               error ("invalid pointer mode %qs", p);
4480               return NULL_TREE;
4481             }
4482
4483           if (TREE_CODE (type) == POINTER_TYPE)
4484             fn = build_pointer_type_for_mode;
4485           else
4486             fn = build_reference_type_for_mode;
4487           typefm = fn (TREE_TYPE (type), mode, false);
4488         }
4489       else
4490         typefm = lang_hooks.types.type_for_mode (mode, TYPE_UNSIGNED (type));
4491
4492       if (typefm == NULL_TREE)
4493         {
4494           error ("no data type for mode %qs", p);
4495           return NULL_TREE;
4496         }
4497       else if (TREE_CODE (type) == ENUMERAL_TYPE)
4498         {
4499           /* For enumeral types, copy the precision from the integer
4500              type returned above.  If not an INTEGER_TYPE, we can't use
4501              this mode for this type.  */
4502           if (TREE_CODE (typefm) != INTEGER_TYPE)
4503             {
4504               error ("cannot use mode %qs for enumeral types", p);
4505               return NULL_TREE;
4506             }
4507
4508           if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4509             type = build_variant_type_copy (type);
4510
4511           /* We cannot use layout_type here, because that will attempt
4512              to re-layout all variants, corrupting our original.  */
4513           TYPE_PRECISION (type) = TYPE_PRECISION (typefm);
4514           TYPE_MIN_VALUE (type) = TYPE_MIN_VALUE (typefm);
4515           TYPE_MAX_VALUE (type) = TYPE_MAX_VALUE (typefm);
4516           TYPE_SIZE (type) = TYPE_SIZE (typefm);
4517           TYPE_SIZE_UNIT (type) = TYPE_SIZE_UNIT (typefm);
4518           TYPE_MODE (type) = TYPE_MODE (typefm);
4519           if (!TYPE_USER_ALIGN (type))
4520             TYPE_ALIGN (type) = TYPE_ALIGN (typefm);
4521
4522           typefm = type;
4523         }
4524       else if (VECTOR_MODE_P (mode)
4525                ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm))
4526                : TREE_CODE (type) != TREE_CODE (typefm))
4527         {
4528           error ("mode %qs applied to inappropriate type", p);
4529           return NULL_TREE;
4530         }
4531
4532       *node = typefm;
4533     }
4534
4535   return NULL_TREE;
4536 }
4537
4538 /* Handle a "section" attribute; arguments as in
4539    struct attribute_spec.handler.  */
4540
4541 static tree
4542 handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args,
4543                           int ARG_UNUSED (flags), bool *no_add_attrs)
4544 {
4545   tree decl = *node;
4546
4547   if (targetm.have_named_sections)
4548     {
4549       user_defined_section_attribute = true;
4550
4551       if ((TREE_CODE (decl) == FUNCTION_DECL
4552            || TREE_CODE (decl) == VAR_DECL)
4553           && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
4554         {
4555           if (TREE_CODE (decl) == VAR_DECL
4556               && current_function_decl != NULL_TREE
4557               && !TREE_STATIC (decl))
4558             {
4559               error ("%Jsection attribute cannot be specified for "
4560                      "local variables", decl);
4561               *no_add_attrs = true;
4562             }
4563
4564           /* The decl may have already been given a section attribute
4565              from a previous declaration.  Ensure they match.  */
4566           else if (DECL_SECTION_NAME (decl) != NULL_TREE
4567                    && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
4568                               TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
4569             {
4570               error ("%Jsection of %qD conflicts with previous declaration",
4571                      *node, *node);
4572               *no_add_attrs = true;
4573             }
4574           else
4575             DECL_SECTION_NAME (decl) = TREE_VALUE (args);
4576         }
4577       else
4578         {
4579           error ("%Jsection attribute not allowed for %qD", *node, *node);
4580           *no_add_attrs = true;
4581         }
4582     }
4583   else
4584     {
4585       error ("%Jsection attributes are not supported for this target", *node);
4586       *no_add_attrs = true;
4587     }
4588
4589   return NULL_TREE;
4590 }
4591
4592 /* Handle a "aligned" attribute; arguments as in
4593    struct attribute_spec.handler.  */
4594
4595 static tree
4596 handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args,
4597                           int flags, bool *no_add_attrs)
4598 {
4599   tree decl = NULL_TREE;
4600   tree *type = NULL;
4601   int is_type = 0;
4602   tree align_expr = (args ? TREE_VALUE (args)
4603                      : size_int (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
4604   int i;
4605
4606   if (DECL_P (*node))
4607     {
4608       decl = *node;
4609       type = &TREE_TYPE (decl);
4610       is_type = TREE_CODE (*node) == TYPE_DECL;
4611     }
4612   else if (TYPE_P (*node))
4613     type = node, is_type = 1;
4614
4615   if (TREE_CODE (align_expr) != INTEGER_CST)
4616     {
4617       error ("requested alignment is not a constant");
4618       *no_add_attrs = true;
4619     }
4620   else if ((i = tree_log2 (align_expr)) == -1)
4621     {
4622       error ("requested alignment is not a power of 2");
4623       *no_add_attrs = true;
4624     }
4625   else if (i > HOST_BITS_PER_INT - 2)
4626     {
4627       error ("requested alignment is too large");
4628       *no_add_attrs = true;
4629     }
4630   else if (is_type)
4631     {
4632       /* If we have a TYPE_DECL, then copy the type, so that we
4633          don't accidentally modify a builtin type.  See pushdecl.  */
4634       if (decl && TREE_TYPE (decl) != error_mark_node
4635           && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
4636         {
4637           tree tt = TREE_TYPE (decl);
4638           *type = build_variant_type_copy (*type);
4639           DECL_ORIGINAL_TYPE (decl) = tt;
4640           TYPE_NAME (*type) = decl;
4641           TREE_USED (*type) = TREE_USED (decl);
4642           TREE_TYPE (decl) = *type;
4643         }
4644       else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4645         *type = build_variant_type_copy (*type);
4646
4647       TYPE_ALIGN (*type) = (1 << i) * BITS_PER_UNIT;
4648       TYPE_USER_ALIGN (*type) = 1;
4649     }
4650   else if (TREE_CODE (decl) != VAR_DECL
4651            && TREE_CODE (decl) != FIELD_DECL)
4652     {
4653       error ("%Jalignment may not be specified for %qD", decl, decl);
4654       *no_add_attrs = true;
4655     }
4656   else
4657     {
4658       DECL_ALIGN (decl) = (1 << i) * BITS_PER_UNIT;
4659       DECL_USER_ALIGN (decl) = 1;
4660     }
4661
4662   return NULL_TREE;
4663 }
4664
4665 /* Handle a "weak" attribute; arguments as in
4666    struct attribute_spec.handler.  */
4667
4668 static tree
4669 handle_weak_attribute (tree *node, tree ARG_UNUSED (name),
4670                        tree ARG_UNUSED (args),
4671                        int ARG_UNUSED (flags),
4672                        bool * ARG_UNUSED (no_add_attrs))
4673 {
4674   declare_weak (*node);
4675
4676   return NULL_TREE;
4677 }
4678
4679 /* Handle an "alias" attribute; arguments as in
4680    struct attribute_spec.handler.  */
4681
4682 static tree
4683 handle_alias_attribute (tree *node, tree name, tree args,
4684                         int ARG_UNUSED (flags), bool *no_add_attrs)
4685 {
4686   tree decl = *node;
4687
4688   if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
4689       || (TREE_CODE (decl) != FUNCTION_DECL && !DECL_EXTERNAL (decl)))
4690     {
4691       error ("%J%qD defined both normally and as an alias", decl, decl);
4692       *no_add_attrs = true;
4693     }
4694
4695   /* Note that the very first time we process a nested declaration,
4696      decl_function_context will not be set.  Indeed, *would* never
4697      be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that
4698      we do below.  After such frobbery, pushdecl would set the context.
4699      In any case, this is never what we want.  */
4700   else if (decl_function_context (decl) == 0 && current_function_decl == NULL)
4701     {
4702       tree id;
4703
4704       id = TREE_VALUE (args);
4705       if (TREE_CODE (id) != STRING_CST)
4706         {
4707           error ("alias argument not a string");
4708           *no_add_attrs = true;
4709           return NULL_TREE;
4710         }
4711       id = get_identifier (TREE_STRING_POINTER (id));
4712       /* This counts as a use of the object pointed to.  */
4713       TREE_USED (id) = 1;
4714
4715       if (TREE_CODE (decl) == FUNCTION_DECL)
4716         DECL_INITIAL (decl) = error_mark_node;
4717       else
4718         {
4719           DECL_EXTERNAL (decl) = 0;
4720           TREE_STATIC (decl) = 1;
4721         }
4722     }
4723   else
4724     {
4725       warning (OPT_Wattributes, "%qE attribute ignored", name);
4726       *no_add_attrs = true;
4727     }
4728
4729   return NULL_TREE;
4730 }
4731
4732 /* Handle an "visibility" attribute; arguments as in
4733    struct attribute_spec.handler.  */
4734
4735 static tree
4736 handle_visibility_attribute (tree *node, tree name, tree args,
4737                              int ARG_UNUSED (flags),
4738                              bool *no_add_attrs)
4739 {
4740   tree decl = *node;
4741   tree id = TREE_VALUE (args);
4742
4743   *no_add_attrs = true;
4744
4745   if (TYPE_P (*node))
4746     {
4747       if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE)
4748        {
4749          warning (OPT_Wattributes, "%qE attribute ignored on non-class types",
4750                   name);
4751          return NULL_TREE;
4752        }
4753     }
4754   else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl))
4755     {
4756       warning (OPT_Wattributes, "%qE attribute ignored", name);
4757       return NULL_TREE;
4758     }
4759
4760   if (TREE_CODE (id) != STRING_CST)
4761     {
4762       error ("visibility argument not a string");
4763       return NULL_TREE;
4764     }
4765
4766   /*  If this is a type, set the visibility on the type decl.  */
4767   if (TYPE_P (decl))
4768     {
4769       decl = TYPE_NAME (decl);
4770       if (!decl)
4771         return NULL_TREE;
4772       if (TREE_CODE (decl) == IDENTIFIER_NODE)
4773         {
4774            warning (OPT_Wattributes, "%qE attribute ignored on types",
4775                     name);
4776            return NULL_TREE;
4777         }
4778     }
4779
4780   if (strcmp (TREE_STRING_POINTER (id), "default") == 0)
4781     DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
4782   else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0)
4783     DECL_VISIBILITY (decl) = VISIBILITY_INTERNAL;
4784   else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0)
4785     DECL_VISIBILITY (decl) = VISIBILITY_HIDDEN;
4786   else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0)
4787     DECL_VISIBILITY (decl) = VISIBILITY_PROTECTED;
4788   else
4789     error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\"");
4790   DECL_VISIBILITY_SPECIFIED (decl) = 1;
4791
4792   /* For decls only, go ahead and attach the attribute to the node as well.
4793      This is needed so we can determine whether we have VISIBILITY_DEFAULT
4794      because the visibility was not specified, or because it was explicitly
4795      overridden from the class visibility.  */
4796   if (DECL_P (*node))
4797     *no_add_attrs = false;
4798
4799   return NULL_TREE;
4800 }
4801
4802 /* Determine the ELF symbol visibility for DECL, which is either a
4803    variable or a function.  It is an error to use this function if a
4804    definition of DECL is not available in this translation unit.
4805    Returns true if the final visibility has been determined by this
4806    function; false if the caller is free to make additional
4807    modifications.  */
4808
4809 bool
4810 c_determine_visibility (tree decl)
4811 {
4812   gcc_assert (TREE_CODE (decl) == VAR_DECL
4813               || TREE_CODE (decl) == FUNCTION_DECL);
4814
4815   /* If the user explicitly specified the visibility with an
4816      attribute, honor that.  DECL_VISIBILITY will have been set during
4817      the processing of the attribute.  We check for an explicit
4818      attribute, rather than just checking DECL_VISIBILITY_SPECIFIED,
4819      to distinguish the use of an attribute from the use of a "#pragma
4820      GCC visibility push(...)"; in the latter case we still want other
4821      considerations to be able to overrule the #pragma.  */
4822   if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl)))
4823     return true;
4824
4825   /* Anything that is exported must have default visibility.  */
4826   if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
4827       && lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))
4828     {
4829       DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
4830       DECL_VISIBILITY_SPECIFIED (decl) = 1;
4831       return true;
4832     }
4833
4834   return false;
4835 }
4836
4837 /* Handle an "tls_model" attribute; arguments as in
4838    struct attribute_spec.handler.  */
4839
4840 static tree
4841 handle_tls_model_attribute (tree *node, tree name, tree args,
4842                             int ARG_UNUSED (flags), bool *no_add_attrs)
4843 {
4844   tree decl = *node;
4845
4846   if (!DECL_THREAD_LOCAL (decl))
4847     {
4848       warning (OPT_Wattributes, "%qE attribute ignored", name);
4849       *no_add_attrs = true;
4850     }
4851   else
4852     {
4853       tree id;
4854
4855       id = TREE_VALUE (args);
4856       if (TREE_CODE (id) != STRING_CST)
4857         {
4858           error ("tls_model argument not a string");
4859           *no_add_attrs = true;
4860           return NULL_TREE;
4861         }
4862       if (strcmp (TREE_STRING_POINTER (id), "local-exec")
4863           && strcmp (TREE_STRING_POINTER (id), "initial-exec")
4864           && strcmp (TREE_STRING_POINTER (id), "local-dynamic")
4865           && strcmp (TREE_STRING_POINTER (id), "global-dynamic"))
4866         {
4867           error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\"");
4868           *no_add_attrs = true;
4869           return NULL_TREE;
4870         }
4871     }
4872
4873   return NULL_TREE;
4874 }
4875
4876 /* Handle a "no_instrument_function" attribute; arguments as in
4877    struct attribute_spec.handler.  */
4878
4879 static tree
4880 handle_no_instrument_function_attribute (tree *node, tree name,
4881                                          tree ARG_UNUSED (args),
4882                                          int ARG_UNUSED (flags),
4883                                          bool *no_add_attrs)
4884 {
4885   tree decl = *node;
4886
4887   if (TREE_CODE (decl) != FUNCTION_DECL)
4888     {
4889       error ("%J%qE attribute applies only to functions", decl, name);
4890       *no_add_attrs = true;
4891     }
4892   else if (DECL_INITIAL (decl))
4893     {
4894       error ("%Jcan%'t set %qE attribute after definition", decl, name);
4895       *no_add_attrs = true;
4896     }
4897   else
4898     DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
4899
4900   return NULL_TREE;
4901 }
4902
4903 /* Handle a "malloc" attribute; arguments as in
4904    struct attribute_spec.handler.  */
4905
4906 static tree
4907 handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4908                          int ARG_UNUSED (flags), bool *no_add_attrs)
4909 {
4910   if (TREE_CODE (*node) == FUNCTION_DECL
4911       && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node))))
4912     DECL_IS_MALLOC (*node) = 1;
4913   else
4914     {
4915       warning (OPT_Wattributes, "%qE attribute ignored", name);
4916       *no_add_attrs = true;
4917     }
4918
4919   return NULL_TREE;
4920 }
4921
4922 /* Handle a "returns_twice" attribute; arguments as in
4923    struct attribute_spec.handler.  */
4924
4925 static tree
4926 handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4927                          int ARG_UNUSED (flags), bool *no_add_attrs)
4928 {
4929   if (TREE_CODE (*node) == FUNCTION_DECL)
4930     DECL_IS_RETURNS_TWICE (*node) = 1;
4931   else
4932     {
4933       warning (OPT_Wattributes, "%qE attribute ignored", name);
4934       *no_add_attrs = true;
4935     }
4936
4937   return NULL_TREE;
4938 }
4939
4940 /* Handle a "no_limit_stack" attribute; arguments as in
4941    struct attribute_spec.handler.  */
4942
4943 static tree
4944 handle_no_limit_stack_attribute (tree *node, tree name,
4945                                  tree ARG_UNUSED (args),
4946                                  int ARG_UNUSED (flags),
4947                                  bool *no_add_attrs)
4948 {
4949   tree decl = *node;
4950
4951   if (TREE_CODE (decl) != FUNCTION_DECL)
4952     {
4953       error ("%J%qE attribute applies only to functions", decl, name);
4954       *no_add_attrs = true;
4955     }
4956   else if (DECL_INITIAL (decl))
4957     {
4958       error ("%Jcan%'t set %qE attribute after definition", decl, name);
4959       *no_add_attrs = true;
4960     }
4961   else
4962     DECL_NO_LIMIT_STACK (decl) = 1;
4963
4964   return NULL_TREE;
4965 }
4966
4967 /* Handle a "pure" attribute; arguments as in
4968    struct attribute_spec.handler.  */
4969
4970 static tree
4971 handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4972                        int ARG_UNUSED (flags), bool *no_add_attrs)
4973 {
4974   if (TREE_CODE (*node) == FUNCTION_DECL)
4975     DECL_IS_PURE (*node) = 1;
4976   /* ??? TODO: Support types.  */
4977   else
4978     {
4979       warning (OPT_Wattributes, "%qE attribute ignored", name);
4980       *no_add_attrs = true;
4981     }
4982
4983   return NULL_TREE;
4984 }
4985
4986 /* Handle a "no vops" attribute; arguments as in
4987    struct attribute_spec.handler.  */
4988
4989 static tree
4990 handle_novops_attribute (tree *node, tree ARG_UNUSED (name),
4991                          tree ARG_UNUSED (args), int ARG_UNUSED (flags),
4992                          bool *ARG_UNUSED (no_add_attrs))
4993 {
4994   gcc_assert (TREE_CODE (*node) == FUNCTION_DECL);
4995   DECL_IS_NOVOPS (*node) = 1;
4996   return NULL_TREE;
4997 }
4998
4999 /* Handle a "deprecated" attribute; arguments as in
5000    struct attribute_spec.handler.  */
5001
5002 static tree
5003 handle_deprecated_attribute (tree *node, tree name,
5004                              tree ARG_UNUSED (args), int flags,
5005                              bool *no_add_attrs)
5006 {
5007   tree type = NULL_TREE;
5008   int warn = 0;
5009   tree what = NULL_TREE;
5010
5011   if (DECL_P (*node))
5012     {
5013       tree decl = *node;
5014       type = TREE_TYPE (decl);
5015
5016       if (TREE_CODE (decl) == TYPE_DECL
5017           || TREE_CODE (decl) == PARM_DECL
5018           || TREE_CODE (decl) == VAR_DECL
5019           || TREE_CODE (decl) == FUNCTION_DECL
5020           || TREE_CODE (decl) == FIELD_DECL)
5021         TREE_DEPRECATED (decl) = 1;
5022       else
5023         warn = 1;
5024     }
5025   else if (TYPE_P (*node))
5026     {
5027       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5028         *node = build_variant_type_copy (*node);
5029       TREE_DEPRECATED (*node) = 1;
5030       type = *node;
5031     }
5032   else
5033     warn = 1;
5034
5035   if (warn)
5036     {
5037       *no_add_attrs = true;
5038       if (type && TYPE_NAME (type))
5039         {
5040           if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
5041             what = TYPE_NAME (*node);
5042           else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
5043                    && DECL_NAME (TYPE_NAME (type)))
5044             what = DECL_NAME (TYPE_NAME (type));
5045         }
5046       if (what)
5047         warning (OPT_Wattributes, "%qE attribute ignored for %qE", name, what);
5048       else
5049         warning (OPT_Wattributes, "%qE attribute ignored", name);
5050     }
5051
5052   return NULL_TREE;
5053 }
5054
5055 /* Handle a "vector_size" attribute; arguments as in
5056    struct attribute_spec.handler.  */
5057
5058 static tree
5059 handle_vector_size_attribute (tree *node, tree name, tree args,
5060                               int ARG_UNUSED (flags),
5061                               bool *no_add_attrs)
5062 {
5063   unsigned HOST_WIDE_INT vecsize, nunits;
5064   enum machine_mode orig_mode;
5065   tree type = *node, new_type, size;
5066
5067   *no_add_attrs = true;
5068
5069   size = TREE_VALUE (args);
5070
5071   if (!host_integerp (size, 1))
5072     {
5073       warning (OPT_Wattributes, "%qE attribute ignored", name);
5074       return NULL_TREE;
5075     }
5076
5077   /* Get the vector size (in bytes).  */
5078   vecsize = tree_low_cst (size, 1);
5079
5080   /* We need to provide for vector pointers, vector arrays, and
5081      functions returning vectors.  For example:
5082
5083        __attribute__((vector_size(16))) short *foo;
5084
5085      In this case, the mode is SI, but the type being modified is
5086      HI, so we need to look further.  */
5087
5088   while (POINTER_TYPE_P (type)
5089          || TREE_CODE (type) == FUNCTION_TYPE
5090          || TREE_CODE (type) == METHOD_TYPE
5091          || TREE_CODE (type) == ARRAY_TYPE)
5092     type = TREE_TYPE (type);
5093
5094   /* Get the mode of the type being modified.  */
5095   orig_mode = TYPE_MODE (type);
5096
5097   if (TREE_CODE (type) == RECORD_TYPE
5098       || (GET_MODE_CLASS (orig_mode) != MODE_FLOAT
5099           && GET_MODE_CLASS (orig_mode) != MODE_INT)
5100       || !host_integerp (TYPE_SIZE_UNIT (type), 1))
5101     {
5102       error ("invalid vector type for attribute %qE", name);
5103       return NULL_TREE;
5104     }
5105
5106   /* Calculate how many units fit in the vector.  */
5107   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
5108   if (nunits & (nunits - 1))
5109     {
5110       error ("number of components of the vector not a power of two");
5111       return NULL_TREE;
5112     }
5113
5114   new_type = build_vector_type (type, nunits);
5115
5116   /* Build back pointers if needed.  */
5117   *node = reconstruct_complex_type (*node, new_type);
5118
5119   return NULL_TREE;
5120 }
5121
5122 /* Handle the "nonnull" attribute.  */
5123 static tree
5124 handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
5125                           tree args, int ARG_UNUSED (flags),
5126                           bool *no_add_attrs)
5127 {
5128   tree type = *node;
5129   unsigned HOST_WIDE_INT attr_arg_num;
5130
5131   /* If no arguments are specified, all pointer arguments should be
5132      non-null.  Verify a full prototype is given so that the arguments
5133      will have the correct types when we actually check them later.  */
5134   if (!args)
5135     {
5136       if (!TYPE_ARG_TYPES (type))
5137         {
5138           error ("nonnull attribute without arguments on a non-prototype");
5139           *no_add_attrs = true;
5140         }
5141       return NULL_TREE;
5142     }
5143
5144   /* Argument list specified.  Verify that each argument number references
5145      a pointer argument.  */
5146   for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
5147     {
5148       tree argument;
5149       unsigned HOST_WIDE_INT arg_num = 0, ck_num;
5150
5151       if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
5152         {
5153           error ("nonnull argument has invalid operand number (argument %lu)",
5154                  (unsigned long) attr_arg_num);
5155           *no_add_attrs = true;
5156           return NULL_TREE;
5157         }
5158
5159       argument = TYPE_ARG_TYPES (type);
5160       if (argument)
5161         {
5162           for (ck_num = 1; ; ck_num++)
5163             {
5164               if (!argument || ck_num == arg_num)
5165                 break;
5166               argument = TREE_CHAIN (argument);
5167             }
5168
5169           if (!argument
5170               || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
5171             {
5172               error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)",
5173                      (unsigned long) attr_arg_num, (unsigned long) arg_num);
5174               *no_add_attrs = true;
5175               return NULL_TREE;
5176             }
5177
5178           if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
5179             {
5180               error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)",
5181                    (unsigned long) attr_arg_num, (unsigned long) arg_num);
5182               *no_add_attrs = true;
5183               return NULL_TREE;
5184             }
5185         }
5186     }
5187
5188   return NULL_TREE;
5189 }
5190
5191 /* Check the argument list of a function call for null in argument slots
5192    that are marked as requiring a non-null pointer argument.  */
5193
5194 static void
5195 check_function_nonnull (tree attrs, tree params)
5196 {
5197   tree a, args, param;
5198   int param_num;
5199
5200   for (a = attrs; a; a = TREE_CHAIN (a))
5201     {
5202       if (is_attribute_p ("nonnull", TREE_PURPOSE (a)))
5203         {
5204           args = TREE_VALUE (a);
5205
5206           /* Walk the argument list.  If we encounter an argument number we
5207              should check for non-null, do it.  If the attribute has no args,
5208              then every pointer argument is checked (in which case the check
5209              for pointer type is done in check_nonnull_arg).  */
5210           for (param = params, param_num = 1; ;
5211                param_num++, param = TREE_CHAIN (param))
5212             {
5213               if (!param)
5214         break;
5215               if (!args || nonnull_check_p (args, param_num))
5216         check_function_arguments_recurse (check_nonnull_arg, NULL,
5217                                           TREE_VALUE (param),
5218                                           param_num);
5219             }
5220         }
5221     }
5222 }
5223
5224 /* Check that the Nth argument of a function call (counting backwards
5225    from the end) is a (pointer)0.  */
5226
5227 static void
5228 check_function_sentinel (tree attrs, tree params, tree typelist)
5229 {
5230   tree attr = lookup_attribute ("sentinel", attrs);
5231
5232   if (attr)
5233     {
5234       /* Skip over the named arguments.  */
5235       while (typelist && params)
5236       {
5237         typelist = TREE_CHAIN (typelist);
5238         params = TREE_CHAIN (params);
5239       }
5240
5241       if (typelist || !params)
5242         warning (0, "not enough variable arguments to fit a sentinel");
5243       else
5244         {
5245           tree sentinel, end;
5246           unsigned pos = 0;
5247
5248           if (TREE_VALUE (attr))
5249             {
5250               tree p = TREE_VALUE (TREE_VALUE (attr));
5251               pos = TREE_INT_CST_LOW (p);
5252             }
5253
5254           sentinel = end = params;
5255
5256           /* Advance `end' ahead of `sentinel' by `pos' positions.  */
5257           while (pos > 0 && TREE_CHAIN (end))
5258             {
5259               pos--;
5260               end = TREE_CHAIN (end);
5261             }
5262           if (pos > 0)
5263             {
5264               warning (0, "not enough variable arguments to fit a sentinel");
5265               return;
5266             }
5267
5268           /* Now advance both until we find the last parameter.  */
5269           while (TREE_CHAIN (end))
5270             {
5271               end = TREE_CHAIN (end);
5272               sentinel = TREE_CHAIN (sentinel);
5273             }
5274
5275           /* Validate the sentinel.  */
5276           if ((!POINTER_TYPE_P (TREE_TYPE (TREE_VALUE (sentinel)))
5277                || !integer_zerop (TREE_VALUE (sentinel)))
5278               /* Although __null (in C++) is only an integer we allow it
5279                  nevertheless, as we are guaranteed that it's exactly
5280                  as wide as a pointer, and we don't want to force
5281                  users to cast the NULL they have written there.
5282                  We warn with -Wstrict-null-sentinel, though.  */
5283               && (warn_strict_null_sentinel
5284                   || null_node != TREE_VALUE (sentinel)))
5285             warning (0, "missing sentinel in function call");
5286         }
5287     }
5288 }
5289
5290 /* Helper for check_function_nonnull; given a list of operands which
5291    must be non-null in ARGS, determine if operand PARAM_NUM should be
5292    checked.  */
5293
5294 static bool
5295 nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num)
5296 {
5297   unsigned HOST_WIDE_INT arg_num = 0;
5298
5299   for (; args; args = TREE_CHAIN (args))
5300     {
5301       bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num);
5302
5303       gcc_assert (found);
5304
5305       if (arg_num == param_num)
5306         return true;
5307     }
5308   return false;
5309 }
5310
5311 /* Check that the function argument PARAM (which is operand number
5312    PARAM_NUM) is non-null.  This is called by check_function_nonnull
5313    via check_function_arguments_recurse.  */
5314
5315 static void
5316 check_nonnull_arg (void * ARG_UNUSED (ctx), tree param,
5317                    unsigned HOST_WIDE_INT param_num)
5318 {
5319   /* Just skip checking the argument if it's not a pointer.  This can
5320      happen if the "nonnull" attribute was given without an operand
5321      list (which means to check every pointer argument).  */
5322
5323   if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE)
5324     return;
5325
5326   if (integer_zerop (param))
5327     warning (0, "null argument where non-null required (argument %lu)",
5328              (unsigned long) param_num);
5329 }
5330
5331 /* Helper for nonnull attribute handling; fetch the operand number
5332    from the attribute argument list.  */
5333
5334 static bool
5335 get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp)
5336 {
5337   /* Verify the arg number is a constant.  */
5338   if (TREE_CODE (arg_num_expr) != INTEGER_CST
5339       || TREE_INT_CST_HIGH (arg_num_expr) != 0)
5340     return false;
5341
5342   *valp = TREE_INT_CST_LOW (arg_num_expr);
5343   return true;
5344 }
5345
5346 /* Handle a "nothrow" attribute; arguments as in
5347    struct attribute_spec.handler.  */
5348
5349 static tree
5350 handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5351                           int ARG_UNUSED (flags), bool *no_add_attrs)
5352 {
5353   if (TREE_CODE (*node) == FUNCTION_DECL)
5354     TREE_NOTHROW (*node) = 1;
5355   /* ??? TODO: Support types.  */
5356   else
5357     {
5358       warning (OPT_Wattributes, "%qE attribute ignored", name);
5359       *no_add_attrs = true;
5360     }
5361
5362   return NULL_TREE;
5363 }
5364
5365 /* Handle a "cleanup" attribute; arguments as in
5366    struct attribute_spec.handler.  */
5367
5368 static tree
5369 handle_cleanup_attribute (tree *node, tree name, tree args,
5370                           int ARG_UNUSED (flags), bool *no_add_attrs)
5371 {
5372   tree decl = *node;
5373   tree cleanup_id, cleanup_decl;
5374
5375   /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do
5376      for global destructors in C++.  This requires infrastructure that
5377      we don't have generically at the moment.  It's also not a feature
5378      we'd be missing too much, since we do have attribute constructor.  */
5379   if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl))
5380     {
5381       warning (OPT_Wattributes, "%qE attribute ignored", name);
5382       *no_add_attrs = true;
5383       return NULL_TREE;
5384     }
5385
5386   /* Verify that the argument is a function in scope.  */
5387   /* ??? We could support pointers to functions here as well, if
5388      that was considered desirable.  */
5389   cleanup_id = TREE_VALUE (args);
5390   if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE)
5391     {
5392       error ("cleanup argument not an identifier");
5393       *no_add_attrs = true;
5394       return NULL_TREE;
5395     }
5396   cleanup_decl = lookup_name (cleanup_id);
5397   if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL)
5398     {
5399       error ("cleanup argument not a function");
5400       *no_add_attrs = true;
5401       return NULL_TREE;
5402     }
5403
5404   /* That the function has proper type is checked with the
5405      eventual call to build_function_call.  */
5406
5407   return NULL_TREE;
5408 }
5409
5410 /* Handle a "warn_unused_result" attribute.  No special handling.  */
5411
5412 static tree
5413 handle_warn_unused_result_attribute (tree *node, tree name,
5414                                tree ARG_UNUSED (args),
5415                                int ARG_UNUSED (flags), bool *no_add_attrs)
5416 {
5417   /* Ignore the attribute for functions not returning any value.  */
5418   if (VOID_TYPE_P (TREE_TYPE (*node)))
5419     {
5420       warning (OPT_Wattributes, "%qE attribute ignored", name);
5421       *no_add_attrs = true;
5422     }
5423
5424   return NULL_TREE;
5425 }
5426
5427 /* Handle a "sentinel" attribute.  */
5428
5429 static tree
5430 handle_sentinel_attribute (tree *node, tree name, tree args,
5431                            int ARG_UNUSED (flags), bool *no_add_attrs)
5432 {
5433   tree params = TYPE_ARG_TYPES (*node);
5434
5435   if (!params)
5436     {
5437       warning (OPT_Wattributes,
5438                "%qE attribute requires prototypes with named arguments", name);
5439       *no_add_attrs = true;
5440     }
5441   else
5442     {
5443       while (TREE_CHAIN (params))
5444         params = TREE_CHAIN (params);
5445
5446       if (VOID_TYPE_P (TREE_VALUE (params)))
5447         {
5448           warning (OPT_Wattributes,
5449                    "%qE attribute only applies to variadic functions", name);
5450           *no_add_attrs = true;
5451         }
5452     }
5453
5454   if (args)
5455     {
5456       tree position = TREE_VALUE (args);
5457
5458       if (TREE_CODE (position) != INTEGER_CST)
5459         {
5460           warning (0, "requested position is not an integer constant");
5461           *no_add_attrs = true;
5462         }
5463       else
5464         {
5465           if (tree_int_cst_lt (position, integer_zero_node))
5466             {
5467               warning (0, "requested position is less than zero");
5468               *no_add_attrs = true;
5469             }
5470         }
5471     }
5472
5473   return NULL_TREE;
5474 }
5475 \f
5476 /* Check for valid arguments being passed to a function.  */
5477 void
5478 check_function_arguments (tree attrs, tree params, tree typelist)
5479 {
5480   /* Check for null being passed in a pointer argument that must be
5481      non-null.  We also need to do this if format checking is enabled.  */
5482
5483   if (warn_nonnull)
5484     check_function_nonnull (attrs, params);
5485
5486   /* Check for errors in format strings.  */
5487
5488   if (warn_format)
5489     {
5490       check_function_format (attrs, params);
5491       check_function_sentinel (attrs, params, typelist);
5492     }
5493 }
5494
5495 /* Generic argument checking recursion routine.  PARAM is the argument to
5496    be checked.  PARAM_NUM is the number of the argument.  CALLBACK is invoked
5497    once the argument is resolved.  CTX is context for the callback.  */
5498 void
5499 check_function_arguments_recurse (void (*callback)
5500                                   (void *, tree, unsigned HOST_WIDE_INT),
5501                                   void *ctx, tree param,
5502                                   unsigned HOST_WIDE_INT param_num)
5503 {
5504   if (TREE_CODE (param) == NOP_EXPR)
5505     {
5506       /* Strip coercion.  */
5507       check_function_arguments_recurse (callback, ctx,
5508                                         TREE_OPERAND (param, 0), param_num);
5509       return;
5510     }
5511
5512   if (TREE_CODE (param) == CALL_EXPR)
5513     {
5514       tree type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (param, 0)));
5515       tree attrs;
5516       bool found_format_arg = false;
5517
5518       /* See if this is a call to a known internationalization function
5519          that modifies a format arg.  Such a function may have multiple
5520          format_arg attributes (for example, ngettext).  */
5521
5522       for (attrs = TYPE_ATTRIBUTES (type);
5523            attrs;
5524            attrs = TREE_CHAIN (attrs))
5525         if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs)))
5526           {
5527             tree inner_args;
5528             tree format_num_expr;
5529             int format_num;
5530             int i;
5531
5532             /* Extract the argument number, which was previously checked
5533                to be valid.  */
5534             format_num_expr = TREE_VALUE (TREE_VALUE (attrs));
5535
5536             gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST
5537                         && !TREE_INT_CST_HIGH (format_num_expr));
5538
5539             format_num = TREE_INT_CST_LOW (format_num_expr);
5540
5541             for (inner_args = TREE_OPERAND (param, 1), i = 1;
5542                  inner_args != 0;
5543                  inner_args = TREE_CHAIN (inner_args), i++)
5544               if (i == format_num)
5545                 {
5546                   check_function_arguments_recurse (callback, ctx,
5547                                                     TREE_VALUE (inner_args),
5548                                                     param_num);
5549                   found_format_arg = true;
5550                   break;
5551                 }
5552           }
5553
5554       /* If we found a format_arg attribute and did a recursive check,
5555          we are done with checking this argument.  Otherwise, we continue
5556          and this will be considered a non-literal.  */
5557       if (found_format_arg)
5558         return;
5559     }
5560
5561   if (TREE_CODE (param) == COND_EXPR)
5562     {
5563       /* Check both halves of the conditional expression.  */
5564       check_function_arguments_recurse (callback, ctx,
5565                                         TREE_OPERAND (param, 1), param_num);
5566       check_function_arguments_recurse (callback, ctx,
5567                                         TREE_OPERAND (param, 2), param_num);
5568       return;
5569     }
5570
5571   (*callback) (ctx, param, param_num);
5572 }
5573
5574 /* Function to help qsort sort FIELD_DECLs by name order.  */
5575
5576 int
5577 field_decl_cmp (const void *x_p, const void *y_p)
5578 {
5579   const tree *const x = (const tree *const) x_p;
5580   const tree *const y = (const tree *const) y_p;
5581
5582   if (DECL_NAME (*x) == DECL_NAME (*y))
5583     /* A nontype is "greater" than a type.  */
5584     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
5585   if (DECL_NAME (*x) == NULL_TREE)
5586     return -1;
5587   if (DECL_NAME (*y) == NULL_TREE)
5588     return 1;
5589   if (DECL_NAME (*x) < DECL_NAME (*y))
5590     return -1;
5591   return 1;
5592 }
5593
5594 static struct {
5595   gt_pointer_operator new_value;
5596   void *cookie;
5597 } resort_data;
5598
5599 /* This routine compares two fields like field_decl_cmp but using the
5600 pointer operator in resort_data.  */
5601
5602 static int
5603 resort_field_decl_cmp (const void *x_p, const void *y_p)
5604 {
5605   const tree *const x = (const tree *const) x_p;
5606   const tree *const y = (const tree *const) y_p;
5607
5608   if (DECL_NAME (*x) == DECL_NAME (*y))
5609     /* A nontype is "greater" than a type.  */
5610     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
5611   if (DECL_NAME (*x) == NULL_TREE)
5612     return -1;
5613   if (DECL_NAME (*y) == NULL_TREE)
5614     return 1;
5615   {
5616     tree d1 = DECL_NAME (*x);
5617     tree d2 = DECL_NAME (*y);
5618     resort_data.new_value (&d1, resort_data.cookie);
5619     resort_data.new_value (&d2, resort_data.cookie);
5620     if (d1 < d2)
5621       return -1;
5622   }
5623   return 1;
5624 }
5625
5626 /* Resort DECL_SORTED_FIELDS because pointers have been reordered.  */
5627
5628 void
5629 resort_sorted_fields (void *obj,
5630                       void * ARG_UNUSED (orig_obj),
5631                       gt_pointer_operator new_value,
5632                       void *cookie)
5633 {
5634   struct sorted_fields_type *sf = (struct sorted_fields_type *) obj;
5635   resort_data.new_value = new_value;
5636   resort_data.cookie = cookie;
5637   qsort (&sf->elts[0], sf->len, sizeof (tree),
5638          resort_field_decl_cmp);
5639 }
5640
5641 /* Subroutine of c_parse_error.
5642    Return the result of concatenating LHS and RHS. RHS is really
5643    a string literal, its first character is indicated by RHS_START and
5644    RHS_SIZE is its length (including the terminating NUL character).
5645
5646    The caller is responsible for deleting the returned pointer.  */
5647
5648 static char *
5649 catenate_strings (const char *lhs, const char *rhs_start, int rhs_size)
5650 {
5651   const int lhs_size = strlen (lhs);
5652   char *result = XNEWVEC (char, lhs_size + rhs_size);
5653   strncpy (result, lhs, lhs_size);
5654   strncpy (result + lhs_size, rhs_start, rhs_size);
5655   return result;
5656 }
5657
5658 /* Issue the error given by GMSGID, indicating that it occurred before
5659    TOKEN, which had the associated VALUE.  */
5660
5661 void
5662 c_parse_error (const char *gmsgid, enum cpp_ttype token, tree value)
5663 {
5664 #define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2))
5665
5666   char *message = NULL;
5667
5668   if (token == CPP_EOF)
5669     message = catenate_messages (gmsgid, " at end of input");
5670   else if (token == CPP_CHAR || token == CPP_WCHAR)
5671     {
5672       unsigned int val = TREE_INT_CST_LOW (value);
5673       const char *const ell = (token == CPP_CHAR) ? "" : "L";
5674       if (val <= UCHAR_MAX && ISGRAPH (val))
5675         message = catenate_messages (gmsgid, " before %s'%c'");
5676       else
5677         message = catenate_messages (gmsgid, " before %s'\\x%x'");
5678
5679       error (message, ell, val);
5680       free (message);
5681       message = NULL;
5682     }
5683   else if (token == CPP_STRING || token == CPP_WSTRING)
5684     message = catenate_messages (gmsgid, " before string constant");
5685   else if (token == CPP_NUMBER)
5686     message = catenate_messages (gmsgid, " before numeric constant");
5687   else if (token == CPP_NAME)
5688     {
5689       message = catenate_messages (gmsgid, " before %qE");
5690       error (message, value);
5691       free (message);
5692       message = NULL;
5693     }
5694   else if (token < N_TTYPES)
5695     {
5696       message = catenate_messages (gmsgid, " before %qs token");
5697       error (message, cpp_type2name (token));
5698       free (message);
5699       message = NULL;
5700     }
5701   else
5702     error (gmsgid);
5703
5704   if (message)
5705     {
5706       error (message);
5707       free (message);
5708     }
5709 #undef catenate_messages
5710 }
5711
5712 /* Walk a gimplified function and warn for functions whose return value is
5713    ignored and attribute((warn_unused_result)) is set.  This is done before
5714    inlining, so we don't have to worry about that.  */
5715
5716 void
5717 c_warn_unused_result (tree *top_p)
5718 {
5719   tree t = *top_p;
5720   tree_stmt_iterator i;
5721   tree fdecl, ftype;
5722
5723   switch (TREE_CODE (t))
5724     {
5725     case STATEMENT_LIST:
5726       for (i = tsi_start (*top_p); !tsi_end_p (i); tsi_next (&i))
5727         c_warn_unused_result (tsi_stmt_ptr (i));
5728       break;
5729
5730     case COND_EXPR:
5731       c_warn_unused_result (&COND_EXPR_THEN (t));
5732       c_warn_unused_result (&COND_EXPR_ELSE (t));
5733       break;
5734     case BIND_EXPR:
5735       c_warn_unused_result (&BIND_EXPR_BODY (t));
5736       break;
5737     case TRY_FINALLY_EXPR:
5738     case TRY_CATCH_EXPR:
5739       c_warn_unused_result (&TREE_OPERAND (t, 0));
5740       c_warn_unused_result (&TREE_OPERAND (t, 1));
5741       break;
5742     case CATCH_EXPR:
5743       c_warn_unused_result (&CATCH_BODY (t));
5744       break;
5745     case EH_FILTER_EXPR:
5746       c_warn_unused_result (&EH_FILTER_FAILURE (t));
5747       break;
5748
5749     case CALL_EXPR:
5750       if (TREE_USED (t))
5751         break;
5752
5753       /* This is a naked call, as opposed to a CALL_EXPR nested inside
5754          a MODIFY_EXPR.  All calls whose value is ignored should be
5755          represented like this.  Look for the attribute.  */
5756       fdecl = get_callee_fndecl (t);
5757       if (fdecl)
5758         ftype = TREE_TYPE (fdecl);
5759       else
5760         {
5761           ftype = TREE_TYPE (TREE_OPERAND (t, 0));
5762           /* Look past pointer-to-function to the function type itself.  */
5763           ftype = TREE_TYPE (ftype);
5764         }
5765
5766       if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype)))
5767         {
5768           if (fdecl)
5769             warning (0, "%Hignoring return value of %qD, "
5770                      "declared with attribute warn_unused_result",
5771                      EXPR_LOCUS (t), fdecl);
5772           else
5773             warning (0, "%Hignoring return value of function "
5774                      "declared with attribute warn_unused_result",
5775                      EXPR_LOCUS (t));
5776         }
5777       break;
5778
5779     default:
5780       /* Not a container, not a call, or a call whose value is used.  */
5781       break;
5782     }
5783 }
5784
5785 /* Convert a character from the host to the target execution character
5786    set.  cpplib handles this, mostly.  */
5787
5788 HOST_WIDE_INT
5789 c_common_to_target_charset (HOST_WIDE_INT c)
5790 {
5791   /* Character constants in GCC proper are sign-extended under -fsigned-char,
5792      zero-extended under -fno-signed-char.  cpplib insists that characters
5793      and character constants are always unsigned.  Hence we must convert
5794      back and forth.  */
5795   cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1);
5796
5797   uc = cpp_host_to_exec_charset (parse_in, uc);
5798
5799   if (flag_signed_char)
5800     return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE)
5801                                >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE);
5802   else
5803     return uc;
5804 }
5805
5806 /* Build the result of __builtin_offsetof.  EXPR is a nested sequence of
5807    component references, with an INDIRECT_REF at the bottom; much like
5808    the traditional rendering of offsetof as a macro.  Returns the folded
5809    and properly cast result.  */
5810
5811 static tree
5812 fold_offsetof_1 (tree expr)
5813 {
5814   enum tree_code code = PLUS_EXPR;
5815   tree base, off, t;
5816
5817   switch (TREE_CODE (expr))
5818     {
5819     case ERROR_MARK:
5820       return expr;
5821
5822     case INDIRECT_REF:
5823       return size_zero_node;
5824
5825     case COMPONENT_REF:
5826       base = fold_offsetof_1 (TREE_OPERAND (expr, 0));
5827       if (base == error_mark_node)
5828         return base;
5829
5830       t = TREE_OPERAND (expr, 1);
5831       if (DECL_C_BIT_FIELD (t))
5832         {
5833           error ("attempt to take address of bit-field structure "
5834                  "member %qD", t);
5835           return error_mark_node;
5836         }
5837       off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t),
5838                         size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t), 1)
5839                                   / BITS_PER_UNIT));
5840       break;
5841
5842     case ARRAY_REF:
5843       base = fold_offsetof_1 (TREE_OPERAND (expr, 0));
5844       if (base == error_mark_node)
5845         return base;
5846
5847       t = TREE_OPERAND (expr, 1);
5848       if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0)
5849         {
5850           code = MINUS_EXPR;
5851           t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t);
5852         }
5853       t = convert (sizetype, t);
5854       off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
5855       break;
5856
5857     default:
5858       gcc_unreachable ();
5859     }
5860
5861   return size_binop (code, base, off);
5862 }
5863
5864 tree
5865 fold_offsetof (tree expr)
5866 {
5867   /* Convert back from the internal sizetype to size_t.  */
5868   return convert (size_type_node, fold_offsetof_1 (expr));
5869 }
5870
5871 /* Print an error message for an invalid lvalue.  USE says
5872    how the lvalue is being used and so selects the error message.  */
5873
5874 void
5875 lvalue_error (enum lvalue_use use)
5876 {
5877   switch (use)
5878     {
5879     case lv_assign:
5880       error ("invalid lvalue in assignment");
5881       break;
5882     case lv_increment:
5883       error ("invalid lvalue in increment");
5884       break;
5885     case lv_decrement:
5886       error ("invalid lvalue in decrement");
5887       break;
5888     case lv_addressof:
5889       error ("invalid lvalue in unary %<&%>");
5890       break;
5891     case lv_asm:
5892       error ("invalid lvalue in asm statement");
5893       break;
5894     default:
5895       gcc_unreachable ();
5896     }
5897 }
5898 \f
5899 /* *PTYPE is an incomplete array.  Complete it with a domain based on
5900    INITIAL_VALUE.  If INITIAL_VALUE is not present, use 1 if DO_DEFAULT
5901    is true.  Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered,
5902    2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty.  */
5903
5904 int
5905 complete_array_type (tree *ptype, tree initial_value, bool do_default)
5906 {
5907   tree maxindex, type, main_type, elt, unqual_elt;
5908   int failure = 0, quals;
5909
5910   maxindex = size_zero_node;
5911   if (initial_value)
5912     {
5913       if (TREE_CODE (initial_value) == STRING_CST)
5914         {
5915           int eltsize
5916             = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value)));
5917           maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1);
5918         }
5919       else if (TREE_CODE (initial_value) == CONSTRUCTOR)
5920         {
5921           tree elts = CONSTRUCTOR_ELTS (initial_value);
5922
5923           if (elts == NULL)
5924             {
5925               if (pedantic)
5926                 failure = 3;
5927               maxindex = integer_minus_one_node;
5928             }
5929           else
5930             {
5931               tree curindex;
5932
5933               if (TREE_PURPOSE (elts))
5934                 maxindex = fold_convert (sizetype, TREE_PURPOSE (elts));
5935               curindex = maxindex;
5936
5937               for (elts = TREE_CHAIN (elts); elts; elts = TREE_CHAIN (elts))
5938                 {
5939                   if (TREE_PURPOSE (elts))
5940                     curindex = fold_convert (sizetype, TREE_PURPOSE (elts));
5941                   else
5942                     curindex = size_binop (PLUS_EXPR, curindex, size_one_node);
5943
5944                   if (tree_int_cst_lt (maxindex, curindex))
5945                     maxindex = curindex;
5946                 }
5947             }
5948         }
5949       else
5950         {
5951           /* Make an error message unless that happened already.  */
5952           if (initial_value != error_mark_node)
5953             failure = 1;
5954         }
5955     }
5956   else
5957     {
5958       failure = 2;
5959       if (!do_default)
5960         return failure;
5961     }
5962
5963   type = *ptype;
5964   elt = TREE_TYPE (type);
5965   quals = TYPE_QUALS (strip_array_types (elt));
5966   if (quals == 0)
5967     unqual_elt = elt;
5968   else
5969     unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
5970
5971   /* Using build_distinct_type_copy and modifying things afterward instead
5972      of using build_array_type to create a new type preserves all of the
5973      TYPE_LANG_FLAG_? bits that the front end may have set.  */
5974   main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
5975   TREE_TYPE (main_type) = unqual_elt;
5976   TYPE_DOMAIN (main_type) = build_index_type (maxindex);
5977   layout_type (main_type);
5978
5979   if (quals == 0)
5980     type = main_type;
5981   else
5982     type = c_build_qualified_type (main_type, quals);
5983
5984   *ptype = type;
5985   return failure;
5986 }
5987
5988 \f
5989 /* Used to help initialize the builtin-types.def table.  When a type of
5990    the correct size doesn't exist, use error_mark_node instead of NULL.
5991    The later results in segfaults even when a decl using the type doesn't
5992    get invoked.  */
5993
5994 tree
5995 builtin_type_for_size (int size, bool unsignedp)
5996 {
5997   tree type = lang_hooks.types.type_for_size (size, unsignedp);
5998   return type ? type : error_mark_node;
5999 }
6000
6001 /* A helper function for resolve_overloaded_builtin in resolving the
6002    overloaded __sync_ builtins.  Returns a positive power of 2 if the
6003    first operand of PARAMS is a pointer to a supported data type.
6004    Returns 0 if an error is encountered.  */
6005
6006 static int
6007 sync_resolve_size (tree function, tree params)
6008 {
6009   tree type;
6010   int size;
6011
6012   if (params == NULL)
6013     {
6014       error ("too few arguments to function %qE", function);
6015       return 0;
6016     }
6017
6018   type = TREE_TYPE (TREE_VALUE (params));
6019   if (TREE_CODE (type) != POINTER_TYPE)
6020     goto incompatible;
6021
6022   type = TREE_TYPE (type);
6023   if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
6024     goto incompatible;
6025
6026   size = tree_low_cst (TYPE_SIZE_UNIT (type), 1);
6027   if (size == 1 || size == 2 || size == 4 || size == 8)
6028     return size;
6029
6030  incompatible:
6031   error ("incompatible type for argument %d of %qE", 1, function);
6032   return 0;
6033 }
6034
6035 /* A helper function for resolve_overloaded_builtin.  Adds casts to
6036    PARAMS to make arguments match up with those of FUNCTION.  Drops
6037    the variadic arguments at the end.  Returns false if some error
6038    was encountered; true on success.  */
6039
6040 static bool
6041 sync_resolve_params (tree orig_function, tree function, tree params)
6042 {
6043   tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (function));
6044   tree ptype;
6045   int number;
6046
6047   /* We've declared the implementation functions to use "volatile void *"
6048      as the pointer parameter, so we shouldn't get any complaints from the
6049      call to check_function_arguments what ever type the user used.  */
6050   arg_types = TREE_CHAIN (arg_types);
6051   ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params)));
6052   number = 2;
6053
6054   /* For the rest of the values, we need to cast these to FTYPE, so that we
6055      don't get warnings for passing pointer types, etc.  */
6056   while (arg_types != void_list_node)
6057     {
6058       tree val;
6059
6060       params = TREE_CHAIN (params);
6061       if (params == NULL)
6062         {
6063           error ("too few arguments to function %qE", orig_function);
6064           return false;
6065         }
6066
6067       /* ??? Ideally for the first conversion we'd use convert_for_assignment
6068          so that we get warnings for anything that doesn't match the pointer
6069          type.  This isn't portable across the C and C++ front ends atm.  */
6070       val = TREE_VALUE (params);
6071       val = convert (ptype, val);
6072       val = convert (TREE_VALUE (arg_types), val);
6073       TREE_VALUE (params) = val;
6074
6075       arg_types = TREE_CHAIN (arg_types);
6076       number++;
6077     }
6078
6079   /* The definition of these primitives is variadic, with the remaining
6080      being "an optional list of variables protected by the memory barrier".
6081      No clue what that's supposed to mean, precisely, but we consider all
6082      call-clobbered variables to be protected so we're safe.  */
6083   TREE_CHAIN (params) = NULL;
6084
6085   return true;
6086 }
6087
6088 /* A helper function for resolve_overloaded_builtin.  Adds a cast to
6089    RESULT to make it match the type of the first pointer argument in
6090    PARAMS.  */
6091
6092 static tree
6093 sync_resolve_return (tree params, tree result)
6094 {
6095   tree ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params)));
6096   return convert (ptype, result);
6097 }
6098
6099 /* Some builtin functions are placeholders for other expressions.  This
6100    function should be called immediately after parsing the call expression
6101    before surrounding code has committed to the type of the expression.
6102
6103    FUNCTION is the DECL that has been invoked; it is known to be a builtin.
6104    PARAMS is the argument list for the call.  The return value is non-null
6105    when expansion is complete, and null if normal processing should
6106    continue.  */
6107
6108 tree
6109 resolve_overloaded_builtin (tree function, tree params)
6110 {
6111   enum built_in_function orig_code = DECL_FUNCTION_CODE (function);
6112   switch (DECL_BUILT_IN_CLASS (function))
6113     {
6114     case BUILT_IN_NORMAL:
6115       break;
6116     case BUILT_IN_MD:
6117       if (targetm.resolve_overloaded_builtin)
6118         return targetm.resolve_overloaded_builtin (function, params);
6119       else
6120         return NULL_TREE;
6121     default:
6122       return NULL_TREE;
6123     }
6124
6125   /* Handle BUILT_IN_NORMAL here.  */
6126   switch (orig_code)
6127     {
6128     case BUILT_IN_FETCH_AND_ADD_N:
6129     case BUILT_IN_FETCH_AND_SUB_N:
6130     case BUILT_IN_FETCH_AND_OR_N:
6131     case BUILT_IN_FETCH_AND_AND_N:
6132     case BUILT_IN_FETCH_AND_XOR_N:
6133     case BUILT_IN_FETCH_AND_NAND_N:
6134     case BUILT_IN_ADD_AND_FETCH_N:
6135     case BUILT_IN_SUB_AND_FETCH_N:
6136     case BUILT_IN_OR_AND_FETCH_N:
6137     case BUILT_IN_AND_AND_FETCH_N:
6138     case BUILT_IN_XOR_AND_FETCH_N:
6139     case BUILT_IN_NAND_AND_FETCH_N:
6140     case BUILT_IN_BOOL_COMPARE_AND_SWAP_N:
6141     case BUILT_IN_VAL_COMPARE_AND_SWAP_N:
6142     case BUILT_IN_LOCK_TEST_AND_SET_N:
6143     case BUILT_IN_LOCK_RELEASE_N:
6144       {
6145         int n = sync_resolve_size (function, params);
6146         tree new_function, result;
6147
6148         if (n == 0)
6149           return error_mark_node;
6150
6151         new_function = built_in_decls[orig_code + exact_log2 (n) + 1];
6152         if (!sync_resolve_params (function, new_function, params))
6153           return error_mark_node;
6154
6155         result = build_function_call (new_function, params);
6156         if (orig_code != BUILT_IN_BOOL_COMPARE_AND_SWAP_N
6157             && orig_code != BUILT_IN_LOCK_RELEASE_N)
6158           result = sync_resolve_return (params, result);
6159
6160         return result;
6161       }
6162
6163     default:
6164       return NULL_TREE;
6165     }
6166 }
6167
6168 /* Ignoring their sign, return true if two scalar types are the same.  */
6169 bool
6170 same_scalar_type_ignoring_signedness (tree t1, tree t2)
6171 {
6172   enum tree_code c1 = TREE_CODE (t1), c2 = TREE_CODE (t2);
6173
6174   gcc_assert ((c1 == INTEGER_TYPE || c1 == REAL_TYPE)
6175               && (c2 == INTEGER_TYPE || c2 == REAL_TYPE));
6176
6177   /* Equality works here because c_common_signed_type uses
6178      TYPE_MAIN_VARIANT.  */
6179   return lang_hooks.types.signed_type (t1)
6180     == lang_hooks.types.signed_type (t2);
6181 }
6182
6183 #include "gt-c-common.h"