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, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, 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
  51 cpp_reader *parse_in;           /* Declared in c-pragma.h.  */
  52
  53 /* We let tm.h override the types used here, to handle trivial differences
  54    such as the choice of unsigned int or long unsigned int for size_t.
  55    When machines start needing nontrivial differences in the size type,
  56    it would be best to do something here to figure out automatically
  57    from other information what type to use.  */
  58
  59 #ifndef SIZE_TYPE
  60 #define SIZE_TYPE "long unsigned int"
  61 #endif
  62
  63 #ifndef PID_TYPE
  64 #define PID_TYPE "int"
  65 #endif
  66
  67 #ifndef WCHAR_TYPE
  68 #define WCHAR_TYPE "int"
  69 #endif
  70
  71 /* WCHAR_TYPE gets overridden by -fshort-wchar.  */
  72 #define MODIFIED_WCHAR_TYPE \
  73         (flag_short_wchar ? "short unsigned int" : WCHAR_TYPE)
  74
  75 #ifndef PTRDIFF_TYPE
  76 #define PTRDIFF_TYPE "long int"
  77 #endif
  78
  79 #ifndef WINT_TYPE
  80 #define WINT_TYPE "unsigned int"
  81 #endif
  82
  83 #ifndef INTMAX_TYPE
  84 #define INTMAX_TYPE ((INT_TYPE_SIZE == LONG_LONG_TYPE_SIZE)     \
  85                      ? "int"                                    \
  86                      : ((LONG_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \
  87                         ? "long int"                            \
  88                         : "long long int"))
  89 #endif
  90
  91 #ifndef UINTMAX_TYPE
  92 #define UINTMAX_TYPE ((INT_TYPE_SIZE == LONG_LONG_TYPE_SIZE)    \
  93                      ? "unsigned int"                           \
  94                      : ((LONG_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \
  95                         ? "long unsigned int"                   \
  96                         : "long long unsigned int"))
  97 #endif
  98
  99 /* The following symbols are subsumed in the c_global_trees array, and
 100    listed here individually for documentation purposes.
 101
 102    INTEGER_TYPE and REAL_TYPE nodes for the standard data types.
 103
 104         tree short_integer_type_node;
 105         tree long_integer_type_node;
 106         tree long_long_integer_type_node;
 107
 108         tree short_unsigned_type_node;
 109         tree long_unsigned_type_node;
 110         tree long_long_unsigned_type_node;
 111
 112         tree truthvalue_type_node;
 113         tree truthvalue_false_node;
 114         tree truthvalue_true_node;
 115
 116         tree ptrdiff_type_node;
 117
 118         tree unsigned_char_type_node;
 119         tree signed_char_type_node;
 120         tree wchar_type_node;
 121         tree signed_wchar_type_node;
 122         tree unsigned_wchar_type_node;
 123
 124         tree float_type_node;
 125         tree double_type_node;
 126         tree long_double_type_node;
 127
 128         tree complex_integer_type_node;
 129         tree complex_float_type_node;
 130         tree complex_double_type_node;
 131         tree complex_long_double_type_node;
 132
 133         tree intQI_type_node;
 134         tree intHI_type_node;
 135         tree intSI_type_node;
 136         tree intDI_type_node;
 137         tree intTI_type_node;
 138
 139         tree unsigned_intQI_type_node;
 140         tree unsigned_intHI_type_node;
 141         tree unsigned_intSI_type_node;
 142         tree unsigned_intDI_type_node;
 143         tree unsigned_intTI_type_node;
 144
 145         tree widest_integer_literal_type_node;
 146         tree widest_unsigned_literal_type_node;
 147
 148    Nodes for types `void *' and `const void *'.
 149
 150         tree ptr_type_node, const_ptr_type_node;
 151
 152    Nodes for types `char *' and `const char *'.
 153
 154         tree string_type_node, const_string_type_node;
 155
 156    Type `char[SOMENUMBER]'.
 157    Used when an array of char is needed and the size is irrelevant.
 158
 159         tree char_array_type_node;
 160
 161    Type `int[SOMENUMBER]' or something like it.
 162    Used when an array of int needed and the size is irrelevant.
 163
 164         tree int_array_type_node;
 165
 166    Type `wchar_t[SOMENUMBER]' or something like it.
 167    Used when a wide string literal is created.
 168
 169         tree wchar_array_type_node;
 170
 171    Type `int ()' -- used for implicit declaration of functions.
 172
 173         tree default_function_type;
 174
 175    A VOID_TYPE node, packaged in a TREE_LIST.
 176
 177         tree void_list_node;
 178
 179   The lazily created VAR_DECLs for __FUNCTION__, __PRETTY_FUNCTION__,
 180   and __func__. (C doesn't generate __FUNCTION__ and__PRETTY_FUNCTION__
 181   VAR_DECLS, but C++ does.)
 182
 183         tree function_name_decl_node;
 184         tree pretty_function_name_decl_node;
 185         tree c99_function_name_decl_node;
 186
 187   Stack of nested function name VAR_DECLs.
 188
 189         tree saved_function_name_decls;
 190
 191 */
 192
 193 tree c_global_trees[CTI_MAX];
 194
 195 /* TRUE if a code represents a statement.  The front end init
 196    langhook should take care of initialization of this array.  */
 197
 198 bool statement_code_p[MAX_TREE_CODES];
 199 \f
 200 /* Switches common to the C front ends.  */
 201
 202 /* Nonzero if prepreprocessing only.  */
 203
 204 int flag_preprocess_only;
 205
 206 /* Nonzero means don't output line number information.  */
 207
 208 char flag_no_line_commands;
 209
 210 /* Nonzero causes -E output not to be done, but directives such as
 211    #define that have side effects are still obeyed.  */
 212
 213 char flag_no_output;
 214
 215 /* Nonzero means dump macros in some fashion.  */
 216
 217 char flag_dump_macros;
 218
 219 /* Nonzero means pass #include lines through to the output.  */
 220
 221 char flag_dump_includes;
 222
 223 /* Nonzero means process PCH files while preprocessing.  */
 224
 225 bool flag_pch_preprocess;
 226
 227 /* The file name to which we should write a precompiled header, or
 228    NULL if no header will be written in this compile.  */
 229
 230 const char *pch_file;
 231
 232 /* Nonzero if an ISO standard was selected.  It rejects macros in the
 233    user's namespace.  */
 234 int flag_iso;
 235
 236 /* Nonzero if -undef was given.  It suppresses target built-in macros
 237    and assertions.  */
 238 int flag_undef;
 239
 240 /* Nonzero means don't recognize the non-ANSI builtin functions.  */
 241
 242 int flag_no_builtin;
 243
 244 /* Nonzero means don't recognize the non-ANSI builtin functions.
 245    -ansi sets this.  */
 246
 247 int flag_no_nonansi_builtin;
 248
 249 /* Nonzero means give `double' the same size as `float'.  */
 250
 251 int flag_short_double;
 252
 253 /* Nonzero means give `wchar_t' the same size as `short'.  */
 254
 255 int flag_short_wchar;
 256
 257 /* Nonzero means allow Microsoft extensions without warnings or errors.  */
 258 int flag_ms_extensions;
 259
 260 /* Nonzero means don't recognize the keyword `asm'.  */
 261
 262 int flag_no_asm;
 263
 264 /* Nonzero means give string constants the type `const char *', as mandated
 265    by the standard.  */
 266
 267 int flag_const_strings;
 268
 269 /* Nonzero means to treat bitfields as signed unless they say `unsigned'.  */
 270
 271 int flag_signed_bitfields = 1;
 272
 273 /* Nonzero means warn about deprecated conversion from string constant to
 274    `char *'.  */
 275
 276 int warn_write_strings;
 277
 278 /* Warn about #pragma directives that are not recognized.  */
 279
 280 int warn_unknown_pragmas; /* Tri state variable.  */
 281
 282 /* Warn about format/argument anomalies in calls to formatted I/O functions
 283    (*printf, *scanf, strftime, strfmon, etc.).  */
 284
 285 int warn_format;
 286
 287 /* Zero means that faster, ...NonNil variants of objc_msgSend...
 288    calls will be used in ObjC; passing nil receivers to such calls
 289    will most likely result in crashes.  */
 290 int flag_nil_receivers = 1;
 291
 292 /* Nonzero means that we will allow new ObjC exception syntax (@throw,
 293    @try, etc.) in source code.  */
 294 int flag_objc_exceptions = 0;
 295
 296 /* Nonzero means that we generate NeXT setjmp based exceptions.  */
 297 int flag_objc_sjlj_exceptions = -1;
 298
 299 /* Nonzero means that code generation will be altered to support
 300    "zero-link" execution.  This currently affects ObjC only, but may
 301    affect other languages in the future.  */
 302 int flag_zero_link = 0;
 303
 304 /* Nonzero means emit an '__OBJC, __image_info' for the current translation
 305    unit.  It will inform the ObjC runtime that class definition(s) herein
 306    contained are to replace one(s) previously loaded.  */
 307 int flag_replace_objc_classes = 0;
 308
 309 /* C/ObjC language option variables.  */
 310
 311
 312 /* Nonzero means allow type mismatches in conditional expressions;
 313    just make their values `void'.  */
 314
 315 int flag_cond_mismatch;
 316
 317 /* Nonzero means enable C89 Amendment 1 features.  */
 318
 319 int flag_isoc94;
 320
 321 /* Nonzero means use the ISO C99 dialect of C.  */
 322
 323 int flag_isoc99;
 324
 325 /* Nonzero means that we have builtin functions, and main is an int.  */
 326
 327 int flag_hosted = 1;
 328
 329 /* Warn if main is suspicious.  */
 330
 331 int warn_main;
 332
 333
 334 /* ObjC language option variables.  */
 335
 336
 337 /* Open and close the file for outputting class declarations, if
 338    requested (ObjC).  */
 339
 340 int flag_gen_declaration;
 341
 342 /* Generate code for GNU or NeXT runtime environment.  */
 343
 344 #ifdef NEXT_OBJC_RUNTIME
 345 int flag_next_runtime = 1;
 346 #else
 347 int flag_next_runtime = 0;
 348 #endif
 349
 350 /* Tells the compiler that this is a special run.  Do not perform any
 351    compiling, instead we are to test some platform dependent features
 352    and output a C header file with appropriate definitions.  */
 353
 354 int print_struct_values;
 355
 356 /* ???.  Undocumented.  */
 357
 358 const char *constant_string_class_name;
 359
 360
 361 /* C++ language option variables.  */
 362
 363
 364 /* Nonzero means don't recognize any extension keywords.  */
 365
 366 int flag_no_gnu_keywords;
 367
 368 /* Nonzero means do emit exported implementations of functions even if
 369    they can be inlined.  */
 370
 371 int flag_implement_inlines = 1;
 372
 373 /* Nonzero means that implicit instantiations will be emitted if needed.  */
 374
 375 int flag_implicit_templates = 1;
 376
 377 /* Nonzero means that implicit instantiations of inline templates will be
 378    emitted if needed, even if instantiations of non-inline templates
 379    aren't.  */
 380
 381 int flag_implicit_inline_templates = 1;
 382
 383 /* Nonzero means generate separate instantiation control files and
 384    juggle them at link time.  */
 385
 386 int flag_use_repository;
 387
 388 /* Nonzero if we want to issue diagnostics that the standard says are not
 389    required.  */
 390
 391 int flag_optional_diags = 1;
 392
 393 /* Nonzero means we should attempt to elide constructors when possible.  */
 394
 395 int flag_elide_constructors = 1;
 396
 397 /* Nonzero means that member functions defined in class scope are
 398    inline by default.  */
 399
 400 int flag_default_inline = 1;
 401
 402 /* Controls whether compiler generates 'type descriptor' that give
 403    run-time type information.  */
 404
 405 int flag_rtti = 1;
 406
 407 /* Nonzero if we want to conserve space in the .o files.  We do this
 408    by putting uninitialized data and runtime initialized data into
 409    .common instead of .data at the expense of not flagging multiple
 410    definitions.  */
 411
 412 int flag_conserve_space;
 413
 414 /* Nonzero if we want to obey access control semantics.  */
 415
 416 int flag_access_control = 1;
 417
 418 /* Nonzero if we want to check the return value of new and avoid calling
 419    constructors if it is a null pointer.  */
 420
 421 int flag_check_new;
 422
 423 /* Nonzero if we want the new ISO rules for pushing a new scope for `for'
 424    initialization variables.
 425    0: Old rules, set by -fno-for-scope.
 426    2: New ISO rules, set by -ffor-scope.
 427    1: Try to implement new ISO rules, but with backup compatibility
 428    (and warnings).  This is the default, for now.  */
 429
 430 int flag_new_for_scope = 1;
 431
 432 /* Nonzero if we want to emit defined symbols with common-like linkage as
 433    weak symbols where possible, in order to conform to C++ semantics.
 434    Otherwise, emit them as local symbols.  */
 435
 436 int flag_weak = 1;
 437
 438 /* 0 means we want the preprocessor to not emit line directives for
 439    the current working directory.  1 means we want it to do it.  -1
 440    means we should decide depending on whether debugging information
 441    is being emitted or not.  */
 442
 443 int flag_working_directory = -1;
 444
 445 /* Nonzero to use __cxa_atexit, rather than atexit, to register
 446    destructors for local statics and global objects.  */
 447
 448 int flag_use_cxa_atexit = DEFAULT_USE_CXA_ATEXIT;
 449
 450 /* Nonzero means make the default pedwarns warnings instead of errors.
 451    The value of this flag is ignored if -pedantic is specified.  */
 452
 453 int flag_permissive;
 454
 455 /* Nonzero means to implement standard semantics for exception
 456    specifications, calling unexpected if an exception is thrown that
 457    doesn't match the specification.  Zero means to treat them as
 458    assertions and optimize accordingly, but not check them.  */
 459
 460 int flag_enforce_eh_specs = 1;
 461
 462 /* Nonzero means to generate thread-safe code for initializing local
 463    statics.  */
 464
 465 int flag_threadsafe_statics = 1;
 466
 467 /* Nonzero means warn about implicit declarations.  */
 468
 469 int warn_implicit = 1;
 470
 471 /* Maximum template instantiation depth.  This limit is rather
 472    arbitrary, but it exists to limit the time it takes to notice
 473    infinite template instantiations.  */
 474
 475 int max_tinst_depth = 500;
 476
 477
 478
 479 /* The elements of `ridpointers' are identifier nodes for the reserved
 480    type names and storage classes.  It is indexed by a RID_... value.  */
 481 tree *ridpointers;
 482
 483 tree (*make_fname_decl) (tree, int);
 484
 485 /* Nonzero means the expression being parsed will never be evaluated.
 486    This is a count, since unevaluated expressions can nest.  */
 487 int skip_evaluation;
 488
 489 /* Information about how a function name is generated.  */
 490 struct fname_var_t
 491 {
 492   tree *const decl;     /* pointer to the VAR_DECL.  */
 493   const unsigned rid;   /* RID number for the identifier.  */
 494   const int pretty;     /* How pretty is it? */
 495 };
 496
 497 /* The three ways of getting then name of the current function.  */
 498
 499 const struct fname_var_t fname_vars[] =
 500 {
 501   /* C99 compliant __func__, must be first.  */
 502   {&c99_function_name_decl_node, RID_C99_FUNCTION_NAME, 0},
 503   /* GCC __FUNCTION__ compliant.  */
 504   {&function_name_decl_node, RID_FUNCTION_NAME, 0},
 505   /* GCC __PRETTY_FUNCTION__ compliant.  */
 506   {&pretty_function_name_decl_node, RID_PRETTY_FUNCTION_NAME, 1},
 507   {NULL, 0, 0},
 508 };
 509
 510 static int constant_fits_type_p (tree, tree);
 511 static tree check_case_value (tree);
 512 static bool check_case_bounds (tree, tree, tree *, tree *);
 513
 514 static tree handle_packed_attribute (tree *, tree, tree, int, bool *);
 515 static tree handle_nocommon_attribute (tree *, tree, tree, int, bool *);
 516 static tree handle_common_attribute (tree *, tree, tree, int, bool *);
 517 static tree handle_noreturn_attribute (tree *, tree, tree, int, bool *);
 518 static tree handle_noinline_attribute (tree *, tree, tree, int, bool *);
 519 static tree handle_always_inline_attribute (tree *, tree, tree, int,
 520                                             bool *);
 521 static tree handle_used_attribute (tree *, tree, tree, int, bool *);
 522 static tree handle_unused_attribute (tree *, tree, tree, int, bool *);
 523 static tree handle_const_attribute (tree *, tree, tree, int, bool *);
 524 static tree handle_transparent_union_attribute (tree *, tree, tree,
 525                                                 int, bool *);
 526 static tree handle_constructor_attribute (tree *, tree, tree, int, bool *);
 527 static tree handle_destructor_attribute (tree *, tree, tree, int, bool *);
 528 static tree handle_mode_attribute (tree *, tree, tree, int, bool *);
 529 static tree handle_section_attribute (tree *, tree, tree, int, bool *);
 530 static tree handle_aligned_attribute (tree *, tree, tree, int, bool *);
 531 static tree handle_weak_attribute (tree *, tree, tree, int, bool *) ;
 532 static tree handle_alias_attribute (tree *, tree, tree, int, bool *);
 533 static tree handle_visibility_attribute (tree *, tree, tree, int,
 534                                          bool *);
 535 static tree handle_tls_model_attribute (tree *, tree, tree, int,
 536                                         bool *);
 537 static tree handle_no_instrument_function_attribute (tree *, tree,
 538                                                      tree, int, bool *);
 539 static tree handle_malloc_attribute (tree *, tree, tree, int, bool *);
 540 static tree handle_no_limit_stack_attribute (tree *, tree, tree, int,
 541                                              bool *);
 542 static tree handle_pure_attribute (tree *, tree, tree, int, bool *);
 543 static tree handle_deprecated_attribute (tree *, tree, tree, int,
 544                                          bool *);
 545 static tree handle_vector_size_attribute (tree *, tree, tree, int,
 546                                           bool *);
 547 static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *);
 548 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
 549 static tree handle_cleanup_attribute (tree *, tree, tree, int, bool *);
 550 static tree handle_warn_unused_result_attribute (tree *, tree, tree, int,
 551                                                  bool *);
 552 static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *);
 553
 554 static void check_function_nonnull (tree, tree);
 555 static void check_nonnull_arg (void *, tree, unsigned HOST_WIDE_INT);
 556 static bool nonnull_check_p (tree, unsigned HOST_WIDE_INT);
 557 static bool get_nonnull_operand (tree, unsigned HOST_WIDE_INT *);
 558 static int resort_field_decl_cmp (const void *, const void *);
 559
 560 /* Table of machine-independent attributes common to all C-like languages.  */
 561 const struct attribute_spec c_common_attribute_table[] =
 562 {
 563   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 564   { "packed",                 0, 0, false, false, false,
 565                               handle_packed_attribute },
 566   { "nocommon",               0, 0, true,  false, false,
 567                               handle_nocommon_attribute },
 568   { "common",                 0, 0, true,  false, false,
 569                               handle_common_attribute },
 570   /* FIXME: logically, noreturn attributes should be listed as
 571      "false, true, true" and apply to function types.  But implementing this
 572      would require all the places in the compiler that use TREE_THIS_VOLATILE
 573      on a decl to identify non-returning functions to be located and fixed
 574      to check the function type instead.  */
 575   { "noreturn",               0, 0, true,  false, false,
 576                               handle_noreturn_attribute },
 577   { "volatile",               0, 0, true,  false, false,
 578                               handle_noreturn_attribute },
 579   { "noinline",               0, 0, true,  false, false,
 580                               handle_noinline_attribute },
 581   { "always_inline",          0, 0, true,  false, false,
 582                               handle_always_inline_attribute },
 583   { "used",                   0, 0, true,  false, false,
 584                               handle_used_attribute },
 585   { "unused",                 0, 0, false, false, false,
 586                               handle_unused_attribute },
 587   /* The same comments as for noreturn attributes apply to const ones.  */
 588   { "const",                  0, 0, true,  false, false,
 589                               handle_const_attribute },
 590   { "transparent_union",      0, 0, false, false, false,
 591                               handle_transparent_union_attribute },
 592   { "constructor",            0, 0, true,  false, false,
 593                               handle_constructor_attribute },
 594   { "destructor",             0, 0, true,  false, false,
 595                               handle_destructor_attribute },
 596   { "mode",                   1, 1, false,  true, false,
 597                               handle_mode_attribute },
 598   { "section",                1, 1, true,  false, false,
 599                               handle_section_attribute },
 600   { "aligned",                0, 1, false, false, false,
 601                               handle_aligned_attribute },
 602   { "weak",                   0, 0, true,  false, false,
 603                               handle_weak_attribute },
 604   { "alias",                  1, 1, true,  false, false,
 605                               handle_alias_attribute },
 606   { "no_instrument_function", 0, 0, true,  false, false,
 607                               handle_no_instrument_function_attribute },
 608   { "malloc",                 0, 0, true,  false, false,
 609                               handle_malloc_attribute },
 610   { "no_stack_limit",         0, 0, true,  false, false,
 611                               handle_no_limit_stack_attribute },
 612   { "pure",                   0, 0, true,  false, false,
 613                               handle_pure_attribute },
 614   { "deprecated",             0, 0, false, false, false,
 615                               handle_deprecated_attribute },
 616   { "vector_size",            1, 1, false, true, false,
 617                               handle_vector_size_attribute },
 618   { "visibility",             1, 1, false, false, false,
 619                               handle_visibility_attribute },
 620   { "tls_model",              1, 1, true,  false, false,
 621                               handle_tls_model_attribute },
 622   { "nonnull",                0, -1, false, true, true,
 623                               handle_nonnull_attribute },
 624   { "nothrow",                0, 0, true,  false, false,
 625                               handle_nothrow_attribute },
 626   { "may_alias",              0, 0, false, true, false, NULL },
 627   { "cleanup",                1, 1, true, false, false,
 628                               handle_cleanup_attribute },
 629   { "warn_unused_result",     0, 0, false, true, true,
 630                               handle_warn_unused_result_attribute },
 631   { "sentinel",               0, 1, false, true, true,
 632                               handle_sentinel_attribute },
 633   { NULL,                     0, 0, false, false, false, NULL }
 634 };
 635
 636 /* Give the specifications for the format attributes, used by C and all
 637    descendants.  */
 638
 639 const struct attribute_spec c_common_format_attribute_table[] =
 640 {
 641   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 642   { "format",                 3, 3, false, true,  true,
 643                               handle_format_attribute },
 644   { "format_arg",             1, 1, false, true,  true,
 645                               handle_format_arg_attribute },
 646   { NULL,                     0, 0, false, false, false, NULL }
 647 };
 648
 649 /* Push current bindings for the function name VAR_DECLS.  */
 650
 651 void
 652 start_fname_decls (void)
 653 {
 654   unsigned ix;
 655   tree saved = NULL_TREE;
 656
 657   for (ix = 0; fname_vars[ix].decl; ix++)
 658     {
 659       tree decl = *fname_vars[ix].decl;
 660
 661       if (decl)
 662         {
 663           saved = tree_cons (decl, build_int_cst (NULL_TREE, ix), saved);
 664           *fname_vars[ix].decl = NULL_TREE;
 665         }
 666     }
 667   if (saved || saved_function_name_decls)
 668     /* Normally they'll have been NULL, so only push if we've got a
 669        stack, or they are non-NULL.  */
 670     saved_function_name_decls = tree_cons (saved, NULL_TREE,
 671                                            saved_function_name_decls);
 672 }
 673
 674 /* Finish up the current bindings, adding them into the current function's
 675    statement tree.  This must be done _before_ finish_stmt_tree is called.
 676    If there is no current function, we must be at file scope and no statements
 677    are involved. Pop the previous bindings.  */
 678
 679 void
 680 finish_fname_decls (void)
 681 {
 682   unsigned ix;
 683   tree stmts = NULL_TREE;
 684   tree stack = saved_function_name_decls;
 685
 686   for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack))
 687     append_to_statement_list (TREE_VALUE (stack), &stmts);
 688
 689   if (stmts)
 690     {
 691       tree *bodyp = &DECL_SAVED_TREE (current_function_decl);
 692
 693       if (TREE_CODE (*bodyp) == BIND_EXPR)
 694         bodyp = &BIND_EXPR_BODY (*bodyp);
 695
 696       append_to_statement_list (*bodyp, &stmts);
 697       *bodyp = stmts;
 698     }
 699
 700   for (ix = 0; fname_vars[ix].decl; ix++)
 701     *fname_vars[ix].decl = NULL_TREE;
 702
 703   if (stack)
 704     {
 705       /* We had saved values, restore them.  */
 706       tree saved;
 707
 708       for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved))
 709         {
 710           tree decl = TREE_PURPOSE (saved);
 711           unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved));
 712
 713           *fname_vars[ix].decl = decl;
 714         }
 715       stack = TREE_CHAIN (stack);
 716     }
 717   saved_function_name_decls = stack;
 718 }
 719
 720 /* Return the text name of the current function, suitably prettified
 721    by PRETTY_P.  Return string must be freed by caller.  */
 722
 723 const char *
 724 fname_as_string (int pretty_p)
 725 {
 726   const char *name = "top level";
 727   char *namep;
 728   int vrb = 2;
 729
 730   if (!pretty_p)
 731     {
 732       name = "";
 733       vrb = 0;
 734     }
 735
 736   if (current_function_decl)
 737     name = lang_hooks.decl_printable_name (current_function_decl, vrb);
 738
 739   if (c_lex_string_translate)
 740     {
 741       int len = strlen (name) + 3; /* Two for '"'s.  One for NULL.  */
 742       cpp_string cstr = { 0, 0 }, strname;
 743
 744       namep = XNEWVEC (char, len);
 745       snprintf (namep, len, "\"%s\"", name);
 746       strname.text = (unsigned char *) namep;
 747       strname.len = len - 1;
 748
 749       if (cpp_interpret_string (parse_in, &strname, 1, &cstr, false))
 750         {
 751           XDELETEVEC (namep);
 752           return (char *) cstr.text;
 753         }
 754     }
 755   else
 756     namep = xstrdup (name);
 757
 758   return namep;
 759 }
 760
 761 /* Expand DECL if it declares an entity not handled by the
 762    common code.  */
 763
 764 int
 765 c_expand_decl (tree decl)
 766 {
 767   if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl))
 768     {
 769       /* Let the back-end know about this variable.  */
 770       if (!anon_aggr_type_p (TREE_TYPE (decl)))
 771         emit_local_var (decl);
 772       else
 773         expand_anon_union_decl (decl, NULL_TREE,
 774                                 DECL_ANON_UNION_ELEMS (decl));
 775     }
 776   else
 777     return 0;
 778
 779   return 1;
 780 }
 781
 782
 783 /* Return the VAR_DECL for a const char array naming the current
 784    function. If the VAR_DECL has not yet been created, create it
 785    now. RID indicates how it should be formatted and IDENTIFIER_NODE
 786    ID is its name (unfortunately C and C++ hold the RID values of
 787    keywords in different places, so we can't derive RID from ID in
 788    this language independent code.  */
 789
 790 tree
 791 fname_decl (unsigned int rid, tree id)
 792 {
 793   unsigned ix;
 794   tree decl = NULL_TREE;
 795
 796   for (ix = 0; fname_vars[ix].decl; ix++)
 797     if (fname_vars[ix].rid == rid)
 798       break;
 799
 800   decl = *fname_vars[ix].decl;
 801   if (!decl)
 802     {
 803       /* If a tree is built here, it would normally have the lineno of
 804          the current statement.  Later this tree will be moved to the
 805          beginning of the function and this line number will be wrong.
 806          To avoid this problem set the lineno to 0 here; that prevents
 807          it from appearing in the RTL.  */
 808       tree stmts;
 809       location_t saved_location = input_location;
 810 #ifdef USE_MAPPED_LOCATION
 811       input_location = UNKNOWN_LOCATION;
 812 #else
 813       input_line = 0;
 814 #endif
 815
 816       stmts = push_stmt_list ();
 817       decl = (*make_fname_decl) (id, fname_vars[ix].pretty);
 818       stmts = pop_stmt_list (stmts);
 819       if (!IS_EMPTY_STMT (stmts))
 820         saved_function_name_decls
 821           = tree_cons (decl, stmts, saved_function_name_decls);
 822       *fname_vars[ix].decl = decl;
 823       input_location = saved_location;
 824     }
 825   if (!ix && !current_function_decl)
 826     pedwarn ("%qD is not defined outside of function scope", decl);
 827
 828   return decl;
 829 }
 830
 831 /* Given a STRING_CST, give it a suitable array-of-chars data type.  */
 832
 833 tree
 834 fix_string_type (tree value)
 835 {
 836   const int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
 837   const int wide_flag = TREE_TYPE (value) == wchar_array_type_node;
 838   const int nchars_max = flag_isoc99 ? 4095 : 509;
 839   int length = TREE_STRING_LENGTH (value);
 840   int nchars;
 841   tree e_type, i_type, a_type;
 842
 843   /* Compute the number of elements, for the array type.  */
 844   nchars = wide_flag ? length / wchar_bytes : length;
 845
 846   if (pedantic && nchars - 1 > nchars_max && !c_dialect_cxx ())
 847     pedwarn ("string length %qd is greater than the length %qd ISO C%d compilers are required to support",
 848              nchars - 1, nchars_max, flag_isoc99 ? 99 : 89);
 849
 850   e_type = wide_flag ? wchar_type_node : char_type_node;
 851   /* Create the array type for the string constant.  flag_const_strings
 852      says make the string constant an array of const char so that
 853      copying it to a non-const pointer will get a warning.  For C++,
 854      this is the standard behavior.
 855
 856      The C++ front end relies on TYPE_MAIN_VARIANT of a cv-qualified
 857      array type being the unqualified version of that type.
 858      Therefore, if we are constructing an array of const char, we must
 859      construct the matching unqualified array type first.  The C front
 860      end does not require this, but it does no harm, so we do it
 861      unconditionally.  */
 862   i_type = build_index_type (build_int_cst (NULL_TREE, nchars - 1));
 863   a_type = build_array_type (e_type, i_type);
 864   if (flag_const_strings)
 865     a_type = c_build_qualified_type (a_type, TYPE_QUAL_CONST);
 866
 867   TREE_TYPE (value) = a_type;
 868   TREE_CONSTANT (value) = 1;
 869   TREE_INVARIANT (value) = 1;
 870   TREE_READONLY (value) = 1;
 871   TREE_STATIC (value) = 1;
 872   return value;
 873 }
 874 \f
 875 /* Print a warning if a constant expression had overflow in folding.
 876    Invoke this function on every expression that the language
 877    requires to be a constant expression.
 878    Note the ANSI C standard says it is erroneous for a
 879    constant expression to overflow.  */
 880
 881 void
 882 constant_expression_warning (tree value)
 883 {
 884   if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
 885        || TREE_CODE (value) == VECTOR_CST
 886        || TREE_CODE (value) == COMPLEX_CST)
 887       && TREE_CONSTANT_OVERFLOW (value) && pedantic)
 888     pedwarn ("overflow in constant expression");
 889 }
 890
 891 /* Print a warning if an expression had overflow in folding.
 892    Invoke this function on every expression that
 893    (1) appears in the source code, and
 894    (2) might be a constant expression that overflowed, and
 895    (3) is not already checked by convert_and_check;
 896    however, do not invoke this function on operands of explicit casts.  */
 897
 898 void
 899 overflow_warning (tree value)
 900 {
 901   if ((TREE_CODE (value) == INTEGER_CST
 902        || (TREE_CODE (value) == COMPLEX_CST
 903            && TREE_CODE (TREE_REALPART (value)) == INTEGER_CST))
 904       && TREE_OVERFLOW (value))
 905     {
 906       TREE_OVERFLOW (value) = 0;
 907       if (skip_evaluation == 0)
 908         warning ("integer overflow in expression");
 909     }
 910   else if ((TREE_CODE (value) == REAL_CST
 911             || (TREE_CODE (value) == COMPLEX_CST
 912                 && TREE_CODE (TREE_REALPART (value)) == REAL_CST))
 913            && TREE_OVERFLOW (value))
 914     {
 915       TREE_OVERFLOW (value) = 0;
 916       if (skip_evaluation == 0)
 917         warning ("floating point overflow in expression");
 918     }
 919   else if (TREE_CODE (value) == VECTOR_CST && TREE_OVERFLOW (value))
 920     {
 921       TREE_OVERFLOW (value) = 0;
 922       if (skip_evaluation == 0)
 923         warning ("vector overflow in expression");
 924     }
 925 }
 926
 927 /* Print a warning if a large constant is truncated to unsigned,
 928    or if -Wconversion is used and a constant < 0 is converted to unsigned.
 929    Invoke this function on every expression that might be implicitly
 930    converted to an unsigned type.  */
 931
 932 void
 933 unsigned_conversion_warning (tree result, tree operand)
 934 {
 935   tree type = TREE_TYPE (result);
 936
 937   if (TREE_CODE (operand) == INTEGER_CST
 938       && TREE_CODE (type) == INTEGER_TYPE
 939       && TYPE_UNSIGNED (type)
 940       && skip_evaluation == 0
 941       && !int_fits_type_p (operand, type))
 942     {
 943       if (!int_fits_type_p (operand, c_common_signed_type (type)))
 944         /* This detects cases like converting -129 or 256 to unsigned char.  */
 945         warning ("large integer implicitly truncated to unsigned type");
 946       else if (warn_conversion)
 947         warning ("negative integer implicitly converted to unsigned type");
 948     }
 949 }
 950
 951 /* Nonzero if constant C has a value that is permissible
 952    for type TYPE (an INTEGER_TYPE).  */
 953
 954 static int
 955 constant_fits_type_p (tree c, tree type)
 956 {
 957   if (TREE_CODE (c) == INTEGER_CST)
 958     return int_fits_type_p (c, type);
 959
 960   c = convert (type, c);
 961   return !TREE_OVERFLOW (c);
 962 }
 963
 964 /* Nonzero if vector types T1 and T2 can be converted to each other
 965    without an explicit cast.  */
 966 int
 967 vector_types_convertible_p (tree t1, tree t2)
 968 {
 969   return targetm.vector_opaque_p (t1)
 970          || targetm.vector_opaque_p (t2)
 971          || (tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2))
 972              && INTEGRAL_TYPE_P (TREE_TYPE (t1))
 973                 == INTEGRAL_TYPE_P (TREE_TYPE (t2)));
 974 }
 975
 976 /* Convert EXPR to TYPE, warning about conversion problems with constants.
 977    Invoke this function on every expression that is converted implicitly,
 978    i.e. because of language rules and not because of an explicit cast.  */
 979
 980 tree
 981 convert_and_check (tree type, tree expr)
 982 {
 983   tree t = convert (type, expr);
 984   if (TREE_CODE (t) == INTEGER_CST)
 985     {
 986       if (TREE_OVERFLOW (t))
 987         {
 988           TREE_OVERFLOW (t) = 0;
 989
 990           /* Do not diagnose overflow in a constant expression merely
 991              because a conversion overflowed.  */
 992           TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (expr);
 993
 994           /* No warning for converting 0x80000000 to int.  */
 995           if (!(TYPE_UNSIGNED (type) < TYPE_UNSIGNED (TREE_TYPE (expr))
 996                 && TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
 997                 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (expr))))
 998             /* If EXPR fits in the unsigned version of TYPE,
 999                don't warn unless pedantic.  */
1000             if ((pedantic
1001                  || TYPE_UNSIGNED (type)
1002                  || !constant_fits_type_p (expr,
1003                                            c_common_unsigned_type (type)))
1004                 && skip_evaluation == 0)
1005               warning ("overflow in implicit constant conversion");
1006         }
1007       else
1008         unsigned_conversion_warning (t, expr);
1009     }
1010   return t;
1011 }
1012 \f
1013 /* A node in a list that describes references to variables (EXPR), which are
1014    either read accesses if WRITER is zero, or write accesses, in which case
1015    WRITER is the parent of EXPR.  */
1016 struct tlist
1017 {
1018   struct tlist *next;
1019   tree expr, writer;
1020 };
1021
1022 /* Used to implement a cache the results of a call to verify_tree.  We only
1023    use this for SAVE_EXPRs.  */
1024 struct tlist_cache
1025 {
1026   struct tlist_cache *next;
1027   struct tlist *cache_before_sp;
1028   struct tlist *cache_after_sp;
1029   tree expr;
1030 };
1031
1032 /* Obstack to use when allocating tlist structures, and corresponding
1033    firstobj.  */
1034 static struct obstack tlist_obstack;
1035 static char *tlist_firstobj = 0;
1036
1037 /* Keep track of the identifiers we've warned about, so we can avoid duplicate
1038    warnings.  */
1039 static struct tlist *warned_ids;
1040 /* SAVE_EXPRs need special treatment.  We process them only once and then
1041    cache the results.  */
1042 static struct tlist_cache *save_expr_cache;
1043
1044 static void add_tlist (struct tlist **, struct tlist *, tree, int);
1045 static void merge_tlist (struct tlist **, struct tlist *, int);
1046 static void verify_tree (tree, struct tlist **, struct tlist **, tree);
1047 static int warning_candidate_p (tree);
1048 static void warn_for_collisions (struct tlist *);
1049 static void warn_for_collisions_1 (tree, tree, struct tlist *, int);
1050 static struct tlist *new_tlist (struct tlist *, tree, tree);
1051
1052 /* Create a new struct tlist and fill in its fields.  */
1053 static struct tlist *
1054 new_tlist (struct tlist *next, tree t, tree writer)
1055 {
1056   struct tlist *l;
1057   l = XOBNEW (&tlist_obstack, struct tlist);
1058   l->next = next;
1059   l->expr = t;
1060   l->writer = writer;
1061   return l;
1062 }
1063
1064 /* Add duplicates of the nodes found in ADD to the list *TO.  If EXCLUDE_WRITER
1065    is nonnull, we ignore any node we find which has a writer equal to it.  */
1066
1067 static void
1068 add_tlist (struct tlist **to, struct tlist *add, tree exclude_writer, int copy)
1069 {
1070   while (add)
1071     {
1072       struct tlist *next = add->next;
1073       if (!copy)
1074         add->next = *to;
1075       if (!exclude_writer || add->writer != exclude_writer)
1076         *to = copy ? new_tlist (*to, add->expr, add->writer) : add;
1077       add = next;
1078     }
1079 }
1080
1081 /* Merge the nodes of ADD into TO.  This merging process is done so that for
1082    each variable that already exists in TO, no new node is added; however if
1083    there is a write access recorded in ADD, and an occurrence on TO is only
1084    a read access, then the occurrence in TO will be modified to record the
1085    write.  */
1086
1087 static void
1088 merge_tlist (struct tlist **to, struct tlist *add, int copy)
1089 {
1090   struct tlist **end = to;
1091
1092   while (*end)
1093     end = &(*end)->next;
1094
1095   while (add)
1096     {
1097       int found = 0;
1098       struct tlist *tmp2;
1099       struct tlist *next = add->next;
1100
1101       for (tmp2 = *to; tmp2; tmp2 = tmp2->next)
1102         if (tmp2->expr == add->expr)
1103           {
1104             found = 1;
1105             if (!tmp2->writer)
1106               tmp2->writer = add->writer;
1107           }
1108       if (!found)
1109         {
1110           *end = copy ? add : new_tlist (NULL, add->expr, add->writer);
1111           end = &(*end)->next;
1112           *end = 0;
1113         }
1114       add = next;
1115     }
1116 }
1117
1118 /* WRITTEN is a variable, WRITER is its parent.  Warn if any of the variable
1119    references in list LIST conflict with it, excluding reads if ONLY writers
1120    is nonzero.  */
1121
1122 static void
1123 warn_for_collisions_1 (tree written, tree writer, struct tlist *list,
1124                        int only_writes)
1125 {
1126   struct tlist *tmp;
1127
1128   /* Avoid duplicate warnings.  */
1129   for (tmp = warned_ids; tmp; tmp = tmp->next)
1130     if (tmp->expr == written)
1131       return;
1132
1133   while (list)
1134     {
1135       if (list->expr == written
1136           && list->writer != writer
1137           && (!only_writes || list->writer)
1138           && DECL_NAME (list->expr))
1139         {
1140           warned_ids = new_tlist (warned_ids, written, NULL_TREE);
1141           warning ("operation on %qs may be undefined",
1142                    IDENTIFIER_POINTER (DECL_NAME (list->expr)));
1143         }
1144       list = list->next;
1145     }
1146 }
1147
1148 /* Given a list LIST of references to variables, find whether any of these
1149    can cause conflicts due to missing sequence points.  */
1150
1151 static void
1152 warn_for_collisions (struct tlist *list)
1153 {
1154   struct tlist *tmp;
1155
1156   for (tmp = list; tmp; tmp = tmp->next)
1157     {
1158       if (tmp->writer)
1159         warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0);
1160     }
1161 }
1162
1163 /* Return nonzero if X is a tree that can be verified by the sequence point
1164    warnings.  */
1165 static int
1166 warning_candidate_p (tree x)
1167 {
1168   return TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == PARM_DECL;
1169 }
1170
1171 /* Walk the tree X, and record accesses to variables.  If X is written by the
1172    parent tree, WRITER is the parent.
1173    We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP.  If this
1174    expression or its only operand forces a sequence point, then everything up
1175    to the sequence point is stored in PBEFORE_SP.  Everything else gets stored
1176    in PNO_SP.
1177    Once we return, we will have emitted warnings if any subexpression before
1178    such a sequence point could be undefined.  On a higher level, however, the
1179    sequence point may not be relevant, and we'll merge the two lists.
1180
1181    Example: (b++, a) + b;
1182    The call that processes the COMPOUND_EXPR will store the increment of B
1183    in PBEFORE_SP, and the use of A in PNO_SP.  The higher-level call that
1184    processes the PLUS_EXPR will need to merge the two lists so that
1185    eventually, all accesses end up on the same list (and we'll warn about the
1186    unordered subexpressions b++ and b.
1187
1188    A note on merging.  If we modify the former example so that our expression
1189    becomes
1190      (b++, b) + a
1191    care must be taken not simply to add all three expressions into the final
1192    PNO_SP list.  The function merge_tlist takes care of that by merging the
1193    before-SP list of the COMPOUND_EXPR into its after-SP list in a special
1194    way, so that no more than one access to B is recorded.  */
1195
1196 static void
1197 verify_tree (tree x, struct tlist **pbefore_sp, struct tlist **pno_sp,
1198              tree writer)
1199 {
1200   struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3;
1201   enum tree_code code;
1202   enum tree_code_class cl;
1203
1204   /* X may be NULL if it is the operand of an empty statement expression
1205      ({ }).  */
1206   if (x == NULL)
1207     return;
1208
1209  restart:
1210   code = TREE_CODE (x);
1211   cl = TREE_CODE_CLASS (code);
1212
1213   if (warning_candidate_p (x))
1214     {
1215       *pno_sp = new_tlist (*pno_sp, x, writer);
1216       return;
1217     }
1218
1219   switch (code)
1220     {
1221     case CONSTRUCTOR:
1222       return;
1223
1224     case COMPOUND_EXPR:
1225     case TRUTH_ANDIF_EXPR:
1226     case TRUTH_ORIF_EXPR:
1227       tmp_before = tmp_nosp = tmp_list3 = 0;
1228       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1229       warn_for_collisions (tmp_nosp);
1230       merge_tlist (pbefore_sp, tmp_before, 0);
1231       merge_tlist (pbefore_sp, tmp_nosp, 0);
1232       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE);
1233       merge_tlist (pbefore_sp, tmp_list3, 0);
1234       return;
1235
1236     case COND_EXPR:
1237       tmp_before = tmp_list2 = 0;
1238       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE);
1239       warn_for_collisions (tmp_list2);
1240       merge_tlist (pbefore_sp, tmp_before, 0);
1241       merge_tlist (pbefore_sp, tmp_list2, 1);
1242
1243       tmp_list3 = tmp_nosp = 0;
1244       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE);
1245       warn_for_collisions (tmp_nosp);
1246       merge_tlist (pbefore_sp, tmp_list3, 0);
1247
1248       tmp_list3 = tmp_list2 = 0;
1249       verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE);
1250       warn_for_collisions (tmp_list2);
1251       merge_tlist (pbefore_sp, tmp_list3, 0);
1252       /* Rather than add both tmp_nosp and tmp_list2, we have to merge the
1253          two first, to avoid warning for (a ? b++ : b++).  */
1254       merge_tlist (&tmp_nosp, tmp_list2, 0);
1255       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1256       return;
1257
1258     case PREDECREMENT_EXPR:
1259     case PREINCREMENT_EXPR:
1260     case POSTDECREMENT_EXPR:
1261     case POSTINCREMENT_EXPR:
1262       verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x);
1263       return;
1264
1265     case MODIFY_EXPR:
1266       tmp_before = tmp_nosp = tmp_list3 = 0;
1267       verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE);
1268       verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x);
1269       /* Expressions inside the LHS are not ordered wrt. the sequence points
1270          in the RHS.  Example:
1271            *a = (a++, 2)
1272          Despite the fact that the modification of "a" is in the before_sp
1273          list (tmp_before), it conflicts with the use of "a" in the LHS.
1274          We can handle this by adding the contents of tmp_list3
1275          to those of tmp_before, and redoing the collision warnings for that
1276          list.  */
1277       add_tlist (&tmp_before, tmp_list3, x, 1);
1278       warn_for_collisions (tmp_before);
1279       /* Exclude the LHS itself here; we first have to merge it into the
1280          tmp_nosp list.  This is done to avoid warning for "a = a"; if we
1281          didn't exclude the LHS, we'd get it twice, once as a read and once
1282          as a write.  */
1283       add_tlist (pno_sp, tmp_list3, x, 0);
1284       warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1);
1285
1286       merge_tlist (pbefore_sp, tmp_before, 0);
1287       if (warning_candidate_p (TREE_OPERAND (x, 0)))
1288         merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0);
1289       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1);
1290       return;
1291
1292     case CALL_EXPR:
1293       /* We need to warn about conflicts among arguments and conflicts between
1294          args and the function address.  Side effects of the function address,
1295          however, are not ordered by the sequence point of the call.  */
1296       tmp_before = tmp_nosp = tmp_list2 = tmp_list3 = 0;
1297       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1298       if (TREE_OPERAND (x, 1))
1299         verify_tree (TREE_OPERAND (x, 1), &tmp_list2, &tmp_list3, NULL_TREE);
1300       merge_tlist (&tmp_list3, tmp_list2, 0);
1301       add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0);
1302       add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0);
1303       warn_for_collisions (tmp_before);
1304       add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0);
1305       return;
1306
1307     case TREE_LIST:
1308       /* Scan all the list, e.g. indices of multi dimensional array.  */
1309       while (x)
1310         {
1311           tmp_before = tmp_nosp = 0;
1312           verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE);
1313           merge_tlist (&tmp_nosp, tmp_before, 0);
1314           add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1315           x = TREE_CHAIN (x);
1316         }
1317       return;
1318
1319     case SAVE_EXPR:
1320       {
1321         struct tlist_cache *t;
1322         for (t = save_expr_cache; t; t = t->next)
1323           if (t->expr == x)
1324             break;
1325
1326         if (!t)
1327           {
1328             t = XOBNEW (&tlist_obstack, struct tlist_cache);
1329             t->next = save_expr_cache;
1330             t->expr = x;
1331             save_expr_cache = t;
1332
1333             tmp_before = tmp_nosp = 0;
1334             verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1335             warn_for_collisions (tmp_nosp);
1336
1337             tmp_list3 = 0;
1338             while (tmp_nosp)
1339               {
1340                 struct tlist *t = tmp_nosp;
1341                 tmp_nosp = t->next;
1342                 merge_tlist (&tmp_list3, t, 0);
1343               }
1344             t->cache_before_sp = tmp_before;
1345             t->cache_after_sp = tmp_list3;
1346           }
1347         merge_tlist (pbefore_sp, t->cache_before_sp, 1);
1348         add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1);
1349         return;
1350       }
1351
1352     default:
1353       /* For other expressions, simply recurse on their operands.
1354          Manual tail recursion for unary expressions.
1355          Other non-expressions need not be processed.  */
1356       if (cl == tcc_unary)
1357         {
1358           x = TREE_OPERAND (x, 0);
1359           writer = 0;
1360           goto restart;
1361         }
1362       else if (IS_EXPR_CODE_CLASS (cl))
1363         {
1364           int lp;
1365           int max = TREE_CODE_LENGTH (TREE_CODE (x));
1366           for (lp = 0; lp < max; lp++)
1367             {
1368               tmp_before = tmp_nosp = 0;
1369               verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, 0);
1370               merge_tlist (&tmp_nosp, tmp_before, 0);
1371               add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1372             }
1373         }
1374       return;
1375     }
1376 }
1377
1378 /* Try to warn for undefined behavior in EXPR due to missing sequence
1379    points.  */
1380
1381 void
1382 verify_sequence_points (tree expr)
1383 {
1384   struct tlist *before_sp = 0, *after_sp = 0;
1385
1386   warned_ids = 0;
1387   save_expr_cache = 0;
1388   if (tlist_firstobj == 0)
1389     {
1390       gcc_obstack_init (&tlist_obstack);
1391       tlist_firstobj = (char *) obstack_alloc (&tlist_obstack, 0);
1392     }
1393
1394   verify_tree (expr, &before_sp, &after_sp, 0);
1395   warn_for_collisions (after_sp);
1396   obstack_free (&tlist_obstack, tlist_firstobj);
1397 }
1398 \f
1399 /* Validate the expression after `case' and apply default promotions.  */
1400
1401 static tree
1402 check_case_value (tree value)
1403 {
1404   if (value == NULL_TREE)
1405     return value;
1406
1407   /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue.  */
1408   STRIP_TYPE_NOPS (value);
1409   /* In C++, the following is allowed:
1410
1411        const int i = 3;
1412        switch (...) { case i: ... }
1413
1414      So, we try to reduce the VALUE to a constant that way.  */
1415   if (c_dialect_cxx ())
1416     {
1417       value = decl_constant_value (value);
1418       STRIP_TYPE_NOPS (value);
1419       value = fold (value);
1420     }
1421
1422   if (TREE_CODE (value) != INTEGER_CST
1423       && value != error_mark_node)
1424     {
1425       error ("case label does not reduce to an integer constant");
1426       value = error_mark_node;
1427     }
1428   else
1429     /* Promote char or short to int.  */
1430     value = default_conversion (value);
1431
1432   constant_expression_warning (value);
1433
1434   return value;
1435 }
1436 \f
1437 /* See if the case values LOW and HIGH are in the range of the original
1438    type (i.e. before the default conversion to int) of the switch testing
1439    expression.
1440    TYPE is the promoted type of the testing expression, and ORIG_TYPE is
1441    the type before promoting it.  CASE_LOW_P is a pointer to the lower
1442    bound of the case label, and CASE_HIGH_P is the upper bound or NULL
1443    if the case is not a case range.
1444    The caller has to make sure that we are not called with NULL for
1445    CASE_LOW_P (i.e. the default case).
1446    Returns true if the case label is in range of ORIG_TYPE (satured or
1447    untouched) or false if the label is out of range.  */
1448
1449 static bool
1450 check_case_bounds (tree type, tree orig_type,
1451                    tree *case_low_p, tree *case_high_p)
1452 {
1453   tree min_value, max_value;
1454   tree case_low = *case_low_p;
1455   tree case_high = case_high_p ? *case_high_p : case_low;
1456
1457   /* If there was a problem with the original type, do nothing.  */
1458   if (orig_type == error_mark_node)
1459     return true;
1460
1461   min_value = TYPE_MIN_VALUE (orig_type);
1462   max_value = TYPE_MAX_VALUE (orig_type);
1463
1464   /* Case label is less than minimum for type.  */
1465   if (tree_int_cst_compare (case_low, min_value) < 0
1466       && tree_int_cst_compare (case_high, min_value) < 0)
1467     {
1468       warning ("case label value is less than minimum value for type");
1469       return false;
1470     }
1471
1472   /* Case value is greater than maximum for type.  */
1473   if (tree_int_cst_compare (case_low, max_value) > 0
1474       && tree_int_cst_compare (case_high, max_value) > 0)
1475     {
1476       warning ("case label value exceeds maximum value for type");
1477       return false;
1478     }
1479
1480   /* Saturate lower case label value to minimum.  */
1481   if (tree_int_cst_compare (case_high, min_value) >= 0
1482       && tree_int_cst_compare (case_low, min_value) < 0)
1483     {
1484       warning ("lower value in case label range"
1485                " less than minimum value for type");
1486       case_low = min_value;
1487     }
1488
1489   /* Saturate upper case label value to maximum.  */
1490   if (tree_int_cst_compare (case_low, max_value) <= 0
1491       && tree_int_cst_compare (case_high, max_value) > 0)
1492     {
1493       warning ("upper value in case label range"
1494                " exceeds maximum value for type");
1495       case_high = max_value;
1496     }
1497
1498   if (*case_low_p != case_low)
1499     *case_low_p = convert (type, case_low);
1500   if (case_high_p && *case_high_p != case_high)
1501     *case_high_p = convert (type, case_high);
1502
1503   return true;
1504 }
1505 \f
1506 /* Return an integer type with BITS bits of precision,
1507    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
1508
1509 tree
1510 c_common_type_for_size (unsigned int bits, int unsignedp)
1511 {
1512   if (bits == TYPE_PRECISION (integer_type_node))
1513     return unsignedp ? unsigned_type_node : integer_type_node;
1514
1515   if (bits == TYPE_PRECISION (signed_char_type_node))
1516     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1517
1518   if (bits == TYPE_PRECISION (short_integer_type_node))
1519     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1520
1521   if (bits == TYPE_PRECISION (long_integer_type_node))
1522     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1523
1524   if (bits == TYPE_PRECISION (long_long_integer_type_node))
1525     return (unsignedp ? long_long_unsigned_type_node
1526             : long_long_integer_type_node);
1527
1528   if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
1529     return (unsignedp ? widest_unsigned_literal_type_node
1530             : widest_integer_literal_type_node);
1531
1532   if (bits <= TYPE_PRECISION (intQI_type_node))
1533     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1534
1535   if (bits <= TYPE_PRECISION (intHI_type_node))
1536     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1537
1538   if (bits <= TYPE_PRECISION (intSI_type_node))
1539     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1540
1541   if (bits <= TYPE_PRECISION (intDI_type_node))
1542     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1543
1544   return 0;
1545 }
1546
1547 /* Used for communication between c_common_type_for_mode and
1548    c_register_builtin_type.  */
1549 static GTY(()) tree registered_builtin_types;
1550
1551 /* Return a data type that has machine mode MODE.
1552    If the mode is an integer,
1553    then UNSIGNEDP selects between signed and unsigned types.  */
1554
1555 tree
1556 c_common_type_for_mode (enum machine_mode mode, int unsignedp)
1557 {
1558   tree t;
1559
1560   if (mode == TYPE_MODE (integer_type_node))
1561     return unsignedp ? unsigned_type_node : integer_type_node;
1562
1563   if (mode == TYPE_MODE (signed_char_type_node))
1564     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1565
1566   if (mode == TYPE_MODE (short_integer_type_node))
1567     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1568
1569   if (mode == TYPE_MODE (long_integer_type_node))
1570     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1571
1572   if (mode == TYPE_MODE (long_long_integer_type_node))
1573     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
1574
1575   if (mode == TYPE_MODE (widest_integer_literal_type_node))
1576     return unsignedp ? widest_unsigned_literal_type_node
1577                      : widest_integer_literal_type_node;
1578
1579   if (mode == QImode)
1580     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1581
1582   if (mode == HImode)
1583     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1584
1585   if (mode == SImode)
1586     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1587
1588   if (mode == DImode)
1589     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1590
1591 #if HOST_BITS_PER_WIDE_INT >= 64
1592   if (mode == TYPE_MODE (intTI_type_node))
1593     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
1594 #endif
1595
1596   if (mode == TYPE_MODE (float_type_node))
1597     return float_type_node;
1598
1599   if (mode == TYPE_MODE (double_type_node))
1600     return double_type_node;
1601
1602   if (mode == TYPE_MODE (long_double_type_node))
1603     return long_double_type_node;
1604
1605   if (mode == TYPE_MODE (void_type_node))
1606     return void_type_node;
1607
1608   if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
1609     return unsignedp ? make_unsigned_type (mode) : make_signed_type (mode);
1610
1611   if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
1612     return unsignedp ? make_unsigned_type (mode) : make_signed_type (mode);
1613
1614   if (VECTOR_MODE_P (mode))
1615     {
1616       enum machine_mode inner_mode = GET_MODE_INNER (mode);
1617       tree inner_type = c_common_type_for_mode (inner_mode, unsignedp);
1618       if (inner_type != NULL_TREE)
1619         return build_vector_type_for_mode (inner_type, mode);
1620     }
1621
1622   for (t = registered_builtin_types; t; t = TREE_CHAIN (t))
1623     if (TYPE_MODE (TREE_VALUE (t)) == mode)
1624       return TREE_VALUE (t);
1625
1626   return 0;
1627 }
1628
1629 /* Return an unsigned type the same as TYPE in other respects.  */
1630 tree
1631 c_common_unsigned_type (tree type)
1632 {
1633   tree type1 = TYPE_MAIN_VARIANT (type);
1634   if (type1 == signed_char_type_node || type1 == char_type_node)
1635     return unsigned_char_type_node;
1636   if (type1 == integer_type_node)
1637     return unsigned_type_node;
1638   if (type1 == short_integer_type_node)
1639     return short_unsigned_type_node;
1640   if (type1 == long_integer_type_node)
1641     return long_unsigned_type_node;
1642   if (type1 == long_long_integer_type_node)
1643     return long_long_unsigned_type_node;
1644   if (type1 == widest_integer_literal_type_node)
1645     return widest_unsigned_literal_type_node;
1646 #if HOST_BITS_PER_WIDE_INT >= 64
1647   if (type1 == intTI_type_node)
1648     return unsigned_intTI_type_node;
1649 #endif
1650   if (type1 == intDI_type_node)
1651     return unsigned_intDI_type_node;
1652   if (type1 == intSI_type_node)
1653     return unsigned_intSI_type_node;
1654   if (type1 == intHI_type_node)
1655     return unsigned_intHI_type_node;
1656   if (type1 == intQI_type_node)
1657     return unsigned_intQI_type_node;
1658
1659   return c_common_signed_or_unsigned_type (1, type);
1660 }
1661
1662 /* Return a signed type the same as TYPE in other respects.  */
1663
1664 tree
1665 c_common_signed_type (tree type)
1666 {
1667   tree type1 = TYPE_MAIN_VARIANT (type);
1668   if (type1 == unsigned_char_type_node || type1 == char_type_node)
1669     return signed_char_type_node;
1670   if (type1 == unsigned_type_node)
1671     return integer_type_node;
1672   if (type1 == short_unsigned_type_node)
1673     return short_integer_type_node;
1674   if (type1 == long_unsigned_type_node)
1675     return long_integer_type_node;
1676   if (type1 == long_long_unsigned_type_node)
1677     return long_long_integer_type_node;
1678   if (type1 == widest_unsigned_literal_type_node)
1679     return widest_integer_literal_type_node;
1680 #if HOST_BITS_PER_WIDE_INT >= 64
1681   if (type1 == unsigned_intTI_type_node)
1682     return intTI_type_node;
1683 #endif
1684   if (type1 == unsigned_intDI_type_node)
1685     return intDI_type_node;
1686   if (type1 == unsigned_intSI_type_node)
1687     return intSI_type_node;
1688   if (type1 == unsigned_intHI_type_node)
1689     return intHI_type_node;
1690   if (type1 == unsigned_intQI_type_node)
1691     return intQI_type_node;
1692
1693   return c_common_signed_or_unsigned_type (0, type);
1694 }
1695
1696 /* Return a type the same as TYPE except unsigned or
1697    signed according to UNSIGNEDP.  */
1698
1699 tree
1700 c_common_signed_or_unsigned_type (int unsignedp, tree type)
1701 {
1702   if (!INTEGRAL_TYPE_P (type)
1703       || TYPE_UNSIGNED (type) == unsignedp)
1704     return type;
1705
1706   /* For ENUMERAL_TYPEs in C++, must check the mode of the types, not
1707      the precision; they have precision set to match their range, but
1708      may use a wider mode to match an ABI.  If we change modes, we may
1709      wind up with bad conversions.  For INTEGER_TYPEs in C, must check
1710      the precision as well, so as to yield correct results for
1711      bit-field types.  C++ does not have these separate bit-field
1712      types, and producing a signed or unsigned variant of an
1713      ENUMERAL_TYPE may cause other problems as well.  */
1714
1715 #define TYPE_OK(node)                                                       \
1716   (TYPE_MODE (type) == TYPE_MODE (node)                                     \
1717    && (c_dialect_cxx () || TYPE_PRECISION (type) == TYPE_PRECISION (node)))
1718   if (TYPE_OK (signed_char_type_node))
1719     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1720   if (TYPE_OK (integer_type_node))
1721     return unsignedp ? unsigned_type_node : integer_type_node;
1722   if (TYPE_OK (short_integer_type_node))
1723     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1724   if (TYPE_OK (long_integer_type_node))
1725     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1726   if (TYPE_OK (long_long_integer_type_node))
1727     return (unsignedp ? long_long_unsigned_type_node
1728             : long_long_integer_type_node);
1729   if (TYPE_OK (widest_integer_literal_type_node))
1730     return (unsignedp ? widest_unsigned_literal_type_node
1731             : widest_integer_literal_type_node);
1732
1733 #if HOST_BITS_PER_WIDE_INT >= 64
1734   if (TYPE_OK (intTI_type_node))
1735     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
1736 #endif
1737   if (TYPE_OK (intDI_type_node))
1738     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1739   if (TYPE_OK (intSI_type_node))
1740     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1741   if (TYPE_OK (intHI_type_node))
1742     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1743   if (TYPE_OK (intQI_type_node))
1744     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1745 #undef TYPE_OK
1746
1747   if (c_dialect_cxx ())
1748     return type;
1749   else
1750     return build_nonstandard_integer_type (TYPE_PRECISION (type), unsignedp);
1751 }
1752
1753 /* The C version of the register_builtin_type langhook.  */
1754
1755 void
1756 c_register_builtin_type (tree type, const char* name)
1757 {
1758   tree decl;
1759
1760   decl = build_decl (TYPE_DECL, get_identifier (name), type);
1761   DECL_ARTIFICIAL (decl) = 1;
1762   if (!TYPE_NAME (type))
1763     TYPE_NAME (type) = decl;
1764   pushdecl (decl);
1765
1766   registered_builtin_types = tree_cons (0, type, registered_builtin_types);
1767 }
1768
1769 \f
1770 /* Return the minimum number of bits needed to represent VALUE in a
1771    signed or unsigned type, UNSIGNEDP says which.  */
1772
1773 unsigned int
1774 min_precision (tree value, int unsignedp)
1775 {
1776   int log;
1777
1778   /* If the value is negative, compute its negative minus 1.  The latter
1779      adjustment is because the absolute value of the largest negative value
1780      is one larger than the largest positive value.  This is equivalent to
1781      a bit-wise negation, so use that operation instead.  */
1782
1783   if (tree_int_cst_sgn (value) < 0)
1784     value = fold (build1 (BIT_NOT_EXPR, TREE_TYPE (value), value));
1785
1786   /* Return the number of bits needed, taking into account the fact
1787      that we need one more bit for a signed than unsigned type.  */
1788
1789   if (integer_zerop (value))
1790     log = 0;
1791   else
1792     log = tree_floor_log2 (value);
1793
1794   return log + 1 + !unsignedp;
1795 }
1796 \f
1797 /* Print an error message for invalid operands to arith operation
1798    CODE.  NOP_EXPR is used as a special case (see
1799    c_common_truthvalue_conversion).  */
1800
1801 void
1802 binary_op_error (enum tree_code code)
1803 {
1804   const char *opname;
1805
1806   switch (code)
1807     {
1808     case NOP_EXPR:
1809       error ("invalid truth-value expression");
1810       return;
1811
1812     case PLUS_EXPR:
1813       opname = "+"; break;
1814     case MINUS_EXPR:
1815       opname = "-"; break;
1816     case MULT_EXPR:
1817       opname = "*"; break;
1818     case MAX_EXPR:
1819       opname = "max"; break;
1820     case MIN_EXPR:
1821       opname = "min"; break;
1822     case EQ_EXPR:
1823       opname = "=="; break;
1824     case NE_EXPR:
1825       opname = "!="; break;
1826     case LE_EXPR:
1827       opname = "<="; break;
1828     case GE_EXPR:
1829       opname = ">="; break;
1830     case LT_EXPR:
1831       opname = "<"; break;
1832     case GT_EXPR:
1833       opname = ">"; break;
1834     case LSHIFT_EXPR:
1835       opname = "<<"; break;
1836     case RSHIFT_EXPR:
1837       opname = ">>"; break;
1838     case TRUNC_MOD_EXPR:
1839     case FLOOR_MOD_EXPR:
1840       opname = "%"; break;
1841     case TRUNC_DIV_EXPR:
1842     case FLOOR_DIV_EXPR:
1843       opname = "/"; break;
1844     case BIT_AND_EXPR:
1845       opname = "&"; break;
1846     case BIT_IOR_EXPR:
1847       opname = "|"; break;
1848     case TRUTH_ANDIF_EXPR:
1849       opname = "&&"; break;
1850     case TRUTH_ORIF_EXPR:
1851       opname = "||"; break;
1852     case BIT_XOR_EXPR:
1853       opname = "^"; break;
1854     default:
1855       gcc_unreachable ();
1856     }
1857   error ("invalid operands to binary %s", opname);
1858 }
1859 \f
1860 /* Subroutine of build_binary_op, used for comparison operations.
1861    See if the operands have both been converted from subword integer types
1862    and, if so, perhaps change them both back to their original type.
1863    This function is also responsible for converting the two operands
1864    to the proper common type for comparison.
1865
1866    The arguments of this function are all pointers to local variables
1867    of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
1868    RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.
1869
1870    If this function returns nonzero, it means that the comparison has
1871    a constant value.  What this function returns is an expression for
1872    that value.  */
1873
1874 tree
1875 shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr,
1876                  enum tree_code *rescode_ptr)
1877 {
1878   tree type;
1879   tree op0 = *op0_ptr;
1880   tree op1 = *op1_ptr;
1881   int unsignedp0, unsignedp1;
1882   int real1, real2;
1883   tree primop0, primop1;
1884   enum tree_code code = *rescode_ptr;
1885
1886   /* Throw away any conversions to wider types
1887      already present in the operands.  */
1888
1889   primop0 = get_narrower (op0, &unsignedp0);
1890   primop1 = get_narrower (op1, &unsignedp1);
1891
1892   /* Handle the case that OP0 does not *contain* a conversion
1893      but it *requires* conversion to FINAL_TYPE.  */
1894
1895   if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
1896     unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0));
1897   if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
1898     unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1));
1899
1900   /* If one of the operands must be floated, we cannot optimize.  */
1901   real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
1902   real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
1903
1904   /* If first arg is constant, swap the args (changing operation
1905      so value is preserved), for canonicalization.  Don't do this if
1906      the second arg is 0.  */
1907
1908   if (TREE_CONSTANT (primop0)
1909       && !integer_zerop (primop1) && !real_zerop (primop1))
1910     {
1911       tree tem = primop0;
1912       int temi = unsignedp0;
1913       primop0 = primop1;
1914       primop1 = tem;
1915       tem = op0;
1916       op0 = op1;
1917       op1 = tem;
1918       *op0_ptr = op0;
1919       *op1_ptr = op1;
1920       unsignedp0 = unsignedp1;
1921       unsignedp1 = temi;
1922       temi = real1;
1923       real1 = real2;
1924       real2 = temi;
1925
1926       switch (code)
1927         {
1928         case LT_EXPR:
1929           code = GT_EXPR;
1930           break;
1931         case GT_EXPR:
1932           code = LT_EXPR;
1933           break;
1934         case LE_EXPR:
1935           code = GE_EXPR;
1936           break;
1937         case GE_EXPR:
1938           code = LE_EXPR;
1939           break;
1940         default:
1941           break;
1942         }
1943       *rescode_ptr = code;
1944     }
1945
1946   /* If comparing an integer against a constant more bits wide,
1947      maybe we can deduce a value of 1 or 0 independent of the data.
1948      Or else truncate the constant now
1949      rather than extend the variable at run time.
1950
1951      This is only interesting if the constant is the wider arg.
1952      Also, it is not safe if the constant is unsigned and the
1953      variable arg is signed, since in this case the variable
1954      would be sign-extended and then regarded as unsigned.
1955      Our technique fails in this case because the lowest/highest
1956      possible unsigned results don't follow naturally from the
1957      lowest/highest possible values of the variable operand.
1958      For just EQ_EXPR and NE_EXPR there is another technique that
1959      could be used: see if the constant can be faithfully represented
1960      in the other operand's type, by truncating it and reextending it
1961      and see if that preserves the constant's value.  */
1962
1963   if (!real1 && !real2
1964       && TREE_CODE (primop1) == INTEGER_CST
1965       && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
1966     {
1967       int min_gt, max_gt, min_lt, max_lt;
1968       tree maxval, minval;
1969       /* 1 if comparison is nominally unsigned.  */
1970       int unsignedp = TYPE_UNSIGNED (*restype_ptr);
1971       tree val;
1972
1973       type = c_common_signed_or_unsigned_type (unsignedp0,
1974                                                TREE_TYPE (primop0));
1975
1976       maxval = TYPE_MAX_VALUE (type);
1977       minval = TYPE_MIN_VALUE (type);
1978
1979       if (unsignedp && !unsignedp0)
1980         *restype_ptr = c_common_signed_type (*restype_ptr);
1981
1982       if (TREE_TYPE (primop1) != *restype_ptr)
1983         {
1984           /* Convert primop1 to target type, but do not introduce
1985              additional overflow.  We know primop1 is an int_cst.  */
1986           tree tmp = build_int_cst_wide (*restype_ptr,
1987                                          TREE_INT_CST_LOW (primop1),
1988                                          TREE_INT_CST_HIGH (primop1));
1989
1990           primop1 = force_fit_type (tmp, 0, TREE_OVERFLOW (primop1),
1991                                     TREE_CONSTANT_OVERFLOW (primop1));
1992         }
1993       if (type != *restype_ptr)
1994         {
1995           minval = convert (*restype_ptr, minval);
1996           maxval = convert (*restype_ptr, maxval);
1997         }
1998
1999       if (unsignedp && unsignedp0)
2000         {
2001           min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
2002           max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
2003           min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
2004           max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
2005         }
2006       else
2007         {
2008           min_gt = INT_CST_LT (primop1, minval);
2009           max_gt = INT_CST_LT (primop1, maxval);
2010           min_lt = INT_CST_LT (minval, primop1);
2011           max_lt = INT_CST_LT (maxval, primop1);
2012         }
2013
2014       val = 0;
2015       /* This used to be a switch, but Genix compiler can't handle that.  */
2016       if (code == NE_EXPR)
2017         {
2018           if (max_lt || min_gt)
2019             val = truthvalue_true_node;
2020         }
2021       else if (code == EQ_EXPR)
2022         {
2023           if (max_lt || min_gt)
2024             val = truthvalue_false_node;
2025         }
2026       else if (code == LT_EXPR)
2027         {
2028           if (max_lt)
2029             val = truthvalue_true_node;
2030           if (!min_lt)
2031             val = truthvalue_false_node;
2032         }
2033       else if (code == GT_EXPR)
2034         {
2035           if (min_gt)
2036             val = truthvalue_true_node;
2037           if (!max_gt)
2038             val = truthvalue_false_node;
2039         }
2040       else if (code == LE_EXPR)
2041         {
2042           if (!max_gt)
2043             val = truthvalue_true_node;
2044           if (min_gt)
2045             val = truthvalue_false_node;
2046         }
2047       else if (code == GE_EXPR)
2048         {
2049           if (!min_lt)
2050             val = truthvalue_true_node;
2051           if (max_lt)
2052             val = truthvalue_false_node;
2053         }
2054
2055       /* If primop0 was sign-extended and unsigned comparison specd,
2056          we did a signed comparison above using the signed type bounds.
2057          But the comparison we output must be unsigned.
2058
2059          Also, for inequalities, VAL is no good; but if the signed
2060          comparison had *any* fixed result, it follows that the
2061          unsigned comparison just tests the sign in reverse
2062          (positive values are LE, negative ones GE).
2063          So we can generate an unsigned comparison
2064          against an extreme value of the signed type.  */
2065
2066       if (unsignedp && !unsignedp0)
2067         {
2068           if (val != 0)
2069             switch (code)
2070               {
2071               case LT_EXPR:
2072               case GE_EXPR:
2073                 primop1 = TYPE_MIN_VALUE (type);
2074                 val = 0;
2075                 break;
2076
2077               case LE_EXPR:
2078               case GT_EXPR:
2079                 primop1 = TYPE_MAX_VALUE (type);
2080                 val = 0;
2081                 break;
2082
2083               default:
2084                 break;
2085               }
2086           type = c_common_unsigned_type (type);
2087         }
2088
2089       if (TREE_CODE (primop0) != INTEGER_CST)
2090         {
2091           if (val == truthvalue_false_node)
2092             warning ("comparison is always false due to limited range of data type");
2093           if (val == truthvalue_true_node)
2094             warning ("comparison is always true due to limited range of data type");
2095         }
2096
2097       if (val != 0)
2098         {
2099           /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2100           if (TREE_SIDE_EFFECTS (primop0))
2101             return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
2102           return val;
2103         }
2104
2105       /* Value is not predetermined, but do the comparison
2106          in the type of the operand that is not constant.
2107          TYPE is already properly set.  */
2108     }
2109   else if (real1 && real2
2110            && (TYPE_PRECISION (TREE_TYPE (primop0))
2111                == TYPE_PRECISION (TREE_TYPE (primop1))))
2112     type = TREE_TYPE (primop0);
2113
2114   /* If args' natural types are both narrower than nominal type
2115      and both extend in the same manner, compare them
2116      in the type of the wider arg.
2117      Otherwise must actually extend both to the nominal
2118      common type lest different ways of extending
2119      alter the result.
2120      (eg, (short)-1 == (unsigned short)-1  should be 0.)  */
2121
2122   else if (unsignedp0 == unsignedp1 && real1 == real2
2123            && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
2124            && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
2125     {
2126       type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
2127       type = c_common_signed_or_unsigned_type (unsignedp0
2128                                                || TYPE_UNSIGNED (*restype_ptr),
2129                                                type);
2130       /* Make sure shorter operand is extended the right way
2131          to match the longer operand.  */
2132       primop0
2133         = convert (c_common_signed_or_unsigned_type (unsignedp0,
2134                                                      TREE_TYPE (primop0)),
2135                    primop0);
2136       primop1
2137         = convert (c_common_signed_or_unsigned_type (unsignedp1,
2138                                                      TREE_TYPE (primop1)),
2139                    primop1);
2140     }
2141   else
2142     {
2143       /* Here we must do the comparison on the nominal type
2144          using the args exactly as we received them.  */
2145       type = *restype_ptr;
2146       primop0 = op0;
2147       primop1 = op1;
2148
2149       if (!real1 && !real2 && integer_zerop (primop1)
2150           && TYPE_UNSIGNED (*restype_ptr))
2151         {
2152           tree value = 0;
2153           switch (code)
2154             {
2155             case GE_EXPR:
2156               /* All unsigned values are >= 0, so we warn if extra warnings
2157                  are requested.  However, if OP0 is a constant that is
2158                  >= 0, the signedness of the comparison isn't an issue,
2159                  so suppress the warning.  */
2160               if (extra_warnings && !in_system_header
2161                   && !(TREE_CODE (primop0) == INTEGER_CST
2162                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
2163                                                    primop0))))
2164                 warning ("comparison of unsigned expression >= 0 is always true");
2165               value = truthvalue_true_node;
2166               break;
2167
2168             case LT_EXPR:
2169               if (extra_warnings && !in_system_header
2170                   && !(TREE_CODE (primop0) == INTEGER_CST
2171                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
2172                                                    primop0))))
2173                 warning ("comparison of unsigned expression < 0 is always false");
2174               value = truthvalue_false_node;
2175               break;
2176
2177             default:
2178               break;
2179             }
2180
2181           if (value != 0)
2182             {
2183               /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2184               if (TREE_SIDE_EFFECTS (primop0))
2185                 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2186                                primop0, value);
2187               return value;
2188             }
2189         }
2190     }
2191
2192   *op0_ptr = convert (type, primop0);
2193   *op1_ptr = convert (type, primop1);
2194
2195   *restype_ptr = truthvalue_type_node;
2196
2197   return 0;
2198 }
2199 \f
2200 /* Return a tree for the sum or difference (RESULTCODE says which)
2201    of pointer PTROP and integer INTOP.  */
2202
2203 tree
2204 pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
2205 {
2206   tree size_exp;
2207
2208   /* The result is a pointer of the same type that is being added.  */
2209
2210   tree result_type = TREE_TYPE (ptrop);
2211
2212   if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
2213     {
2214       if (pedantic || warn_pointer_arith)
2215         pedwarn ("pointer of type %<void *%> used in arithmetic");
2216       size_exp = integer_one_node;
2217     }
2218   else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE)
2219     {
2220       if (pedantic || warn_pointer_arith)
2221         pedwarn ("pointer to a function used in arithmetic");
2222       size_exp = integer_one_node;
2223     }
2224   else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE)
2225     {
2226       if (pedantic || warn_pointer_arith)
2227         pedwarn ("pointer to member function used in arithmetic");
2228       size_exp = integer_one_node;
2229     }
2230   else
2231     size_exp = size_in_bytes (TREE_TYPE (result_type));
2232
2233   /* If what we are about to multiply by the size of the elements
2234      contains a constant term, apply distributive law
2235      and multiply that constant term separately.
2236      This helps produce common subexpressions.  */
2237
2238   if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
2239       && !TREE_CONSTANT (intop)
2240       && TREE_CONSTANT (TREE_OPERAND (intop, 1))
2241       && TREE_CONSTANT (size_exp)
2242       /* If the constant comes from pointer subtraction,
2243          skip this optimization--it would cause an error.  */
2244       && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
2245       /* If the constant is unsigned, and smaller than the pointer size,
2246          then we must skip this optimization.  This is because it could cause
2247          an overflow error if the constant is negative but INTOP is not.  */
2248       && (!TYPE_UNSIGNED (TREE_TYPE (intop))
2249           || (TYPE_PRECISION (TREE_TYPE (intop))
2250               == TYPE_PRECISION (TREE_TYPE (ptrop)))))
2251     {
2252       enum tree_code subcode = resultcode;
2253       tree int_type = TREE_TYPE (intop);
2254       if (TREE_CODE (intop) == MINUS_EXPR)
2255         subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
2256       /* Convert both subexpression types to the type of intop,
2257          because weird cases involving pointer arithmetic
2258          can result in a sum or difference with different type args.  */
2259       ptrop = build_binary_op (subcode, ptrop,
2260                                convert (int_type, TREE_OPERAND (intop, 1)), 1);
2261       intop = convert (int_type, TREE_OPERAND (intop, 0));
2262     }
2263
2264   /* Convert the integer argument to a type the same size as sizetype
2265      so the multiply won't overflow spuriously.  */
2266
2267   if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype)
2268       || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype))
2269     intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype),
2270                                              TYPE_UNSIGNED (sizetype)), intop);
2271
2272   /* Replace the integer argument with a suitable product by the object size.
2273      Do this multiplication as signed, then convert to the appropriate
2274      pointer type (actually unsigned integral).  */
2275
2276   intop = convert (result_type,
2277                    build_binary_op (MULT_EXPR, intop,
2278                                     convert (TREE_TYPE (intop), size_exp), 1));
2279
2280   /* Create the sum or difference.  */
2281   return fold (build2 (resultcode, result_type, ptrop, intop));
2282 }
2283 \f
2284 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
2285    or validate its data type for an `if' or `while' statement or ?..: exp.
2286
2287    This preparation consists of taking the ordinary
2288    representation of an expression expr and producing a valid tree
2289    boolean expression describing whether expr is nonzero.  We could
2290    simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1),
2291    but we optimize comparisons, &&, ||, and !.
2292
2293    The resulting type should always be `truthvalue_type_node'.  */
2294
2295 tree
2296 c_common_truthvalue_conversion (tree expr)
2297 {
2298   if (TREE_CODE (expr) == ERROR_MARK)
2299     return expr;
2300
2301   if (TREE_CODE (expr) == FUNCTION_DECL)
2302     expr = build_unary_op (ADDR_EXPR, expr, 0);
2303
2304   switch (TREE_CODE (expr))
2305     {
2306     case EQ_EXPR:   case NE_EXPR:   case UNEQ_EXPR: case LTGT_EXPR:
2307     case LE_EXPR:   case GE_EXPR:   case LT_EXPR:   case GT_EXPR:
2308     case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR:
2309     case ORDERED_EXPR: case UNORDERED_EXPR:
2310     case TRUTH_ANDIF_EXPR:
2311     case TRUTH_ORIF_EXPR:
2312     case TRUTH_AND_EXPR:
2313     case TRUTH_OR_EXPR:
2314     case TRUTH_XOR_EXPR:
2315       if (TREE_TYPE (expr) != truthvalue_type_node)
2316         return build2 (TREE_CODE (expr), truthvalue_type_node,
2317                        TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1));
2318       return expr;
2319
2320     case TRUTH_NOT_EXPR:
2321       if (TREE_TYPE (expr) != truthvalue_type_node)
2322         return build1 (TREE_CODE (expr), truthvalue_type_node,
2323                        TREE_OPERAND (expr, 0));
2324       return expr;
2325
2326     case ERROR_MARK:
2327       return expr;
2328
2329     case INTEGER_CST:
2330       /* Avoid integer_zerop to ignore TREE_CONSTANT_OVERFLOW.  */
2331       return (TREE_INT_CST_LOW (expr) != 0 || TREE_INT_CST_HIGH (expr) != 0)
2332              ? truthvalue_true_node
2333              : truthvalue_false_node;
2334
2335     case REAL_CST:
2336       return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0)
2337              ? truthvalue_true_node
2338              : truthvalue_false_node;
2339
2340     case ADDR_EXPR:
2341       {
2342         if (TREE_CODE (TREE_OPERAND (expr, 0)) == FUNCTION_DECL
2343             && !DECL_WEAK (TREE_OPERAND (expr, 0)))
2344           {
2345             /* Common Ada/Pascal programmer's mistake.  We always warn
2346                about this since it is so bad.  */
2347             warning ("the address of %qD, will always evaluate as %<true%>",
2348                      TREE_OPERAND (expr, 0));
2349             return truthvalue_true_node;
2350           }
2351
2352         /* If we are taking the address of an external decl, it might be
2353            zero if it is weak, so we cannot optimize.  */
2354         if (DECL_P (TREE_OPERAND (expr, 0))
2355             && DECL_EXTERNAL (TREE_OPERAND (expr, 0)))
2356           break;
2357
2358         if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 0)))
2359           return build2 (COMPOUND_EXPR, truthvalue_type_node,
2360                          TREE_OPERAND (expr, 0), truthvalue_true_node);
2361         else
2362           return truthvalue_true_node;
2363       }
2364
2365     case COMPLEX_EXPR:
2366       return build_binary_op ((TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
2367                                ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
2368                 lang_hooks.truthvalue_conversion (TREE_OPERAND (expr, 0)),
2369                 lang_hooks.truthvalue_conversion (TREE_OPERAND (expr, 1)),
2370                               0);
2371
2372     case NEGATE_EXPR:
2373     case ABS_EXPR:
2374     case FLOAT_EXPR:
2375       /* These don't change whether an object is nonzero or zero.  */
2376       return lang_hooks.truthvalue_conversion (TREE_OPERAND (expr, 0));
2377
2378     case LROTATE_EXPR:
2379     case RROTATE_EXPR:
2380       /* These don't change whether an object is zero or nonzero, but
2381          we can't ignore them if their second arg has side-effects.  */
2382       if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2383         return build2 (COMPOUND_EXPR, truthvalue_type_node,
2384                        TREE_OPERAND (expr, 1),
2385                        lang_hooks.truthvalue_conversion (TREE_OPERAND (expr, 0)));
2386       else
2387         return lang_hooks.truthvalue_conversion (TREE_OPERAND (expr, 0));
2388
2389     case COND_EXPR:
2390       /* Distribute the conversion into the arms of a COND_EXPR.  */
2391       return fold (build3 (COND_EXPR, truthvalue_type_node,
2392                 TREE_OPERAND (expr, 0),
2393                 lang_hooks.truthvalue_conversion (TREE_OPERAND (expr, 1)),
2394                 lang_hooks.truthvalue_conversion (TREE_OPERAND (expr, 2))));
2395
2396     case CONVERT_EXPR:
2397       /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
2398          since that affects how `default_conversion' will behave.  */
2399       if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
2400           || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
2401         break;
2402       /* Fall through....  */
2403     case NOP_EXPR:
2404       /* If this is widening the argument, we can ignore it.  */
2405       if (TYPE_PRECISION (TREE_TYPE (expr))
2406           >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
2407         return lang_hooks.truthvalue_conversion (TREE_OPERAND (expr, 0));
2408       break;
2409
2410     case MINUS_EXPR:
2411       /* Perhaps reduce (x - y) != 0 to (x != y).  The expressions
2412          aren't guaranteed to the be same for modes that can represent
2413          infinity, since if x and y are both +infinity, or both
2414          -infinity, then x - y is not a number.
2415
2416          Note that this transformation is safe when x or y is NaN.
2417          (x - y) is then NaN, and both (x - y) != 0 and x != y will
2418          be false.  */
2419       if (HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (TREE_OPERAND (expr, 0)))))
2420         break;
2421       /* Fall through....  */
2422     case BIT_XOR_EXPR:
2423       /* This and MINUS_EXPR can be changed into a comparison of the
2424          two objects.  */
2425       if (TREE_TYPE (TREE_OPERAND (expr, 0))
2426           == TREE_TYPE (TREE_OPERAND (expr, 1)))
2427         return build_binary_op (NE_EXPR, TREE_OPERAND (expr, 0),
2428                                 TREE_OPERAND (expr, 1), 1);
2429       return build_binary_op (NE_EXPR, TREE_OPERAND (expr, 0),
2430                               fold (build1 (NOP_EXPR,
2431                                             TREE_TYPE (TREE_OPERAND (expr, 0)),
2432                                             TREE_OPERAND (expr, 1))), 1);
2433
2434     case BIT_AND_EXPR:
2435       if (integer_onep (TREE_OPERAND (expr, 1))
2436           && TREE_TYPE (expr) != truthvalue_type_node)
2437         /* Using convert here would cause infinite recursion.  */
2438         return build1 (NOP_EXPR, truthvalue_type_node, expr);
2439       break;
2440
2441     case MODIFY_EXPR:
2442       if (warn_parentheses && !TREE_NO_WARNING (expr))
2443         warning ("suggest parentheses around assignment used as truth value");
2444       break;
2445
2446     default:
2447       break;
2448     }
2449
2450   if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
2451     {
2452       tree t = save_expr (expr);
2453       return (build_binary_op
2454               ((TREE_SIDE_EFFECTS (expr)
2455                 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
2456         lang_hooks.truthvalue_conversion (build_unary_op (REALPART_EXPR, t, 0)),
2457         lang_hooks.truthvalue_conversion (build_unary_op (IMAGPART_EXPR, t, 0)),
2458                0));
2459     }
2460
2461   return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
2462 }
2463 \f
2464 static tree builtin_function_2 (const char *builtin_name, const char *name,
2465                                 tree builtin_type, tree type,
2466                                 enum built_in_function function_code,
2467                                 enum built_in_class cl, int library_name_p,
2468                                 bool nonansi_p,
2469                                 tree attrs);
2470
2471 /* Make a variant type in the proper way for C/C++, propagating qualifiers
2472    down to the element type of an array.  */
2473
2474 tree
2475 c_build_qualified_type (tree type, int type_quals)
2476 {
2477   if (type == error_mark_node)
2478     return type;
2479
2480   if (TREE_CODE (type) == ARRAY_TYPE)
2481     {
2482       tree t;
2483       tree element_type = c_build_qualified_type (TREE_TYPE (type),
2484                                                   type_quals);
2485
2486       /* See if we already have an identically qualified type.  */
2487       for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
2488         {
2489           if (TYPE_QUALS (strip_array_types (t)) == type_quals
2490               && TYPE_NAME (t) == TYPE_NAME (type)
2491               && TYPE_CONTEXT (t) == TYPE_CONTEXT (type)
2492               && attribute_list_equal (TYPE_ATTRIBUTES (t),
2493                                        TYPE_ATTRIBUTES (type)))
2494             break;
2495         }
2496       if (!t)
2497         {
2498           t = build_variant_type_copy (type);
2499           TREE_TYPE (t) = element_type;
2500         }
2501       return t;
2502     }
2503
2504   /* A restrict-qualified pointer type must be a pointer to object or
2505      incomplete type.  Note that the use of POINTER_TYPE_P also allows
2506      REFERENCE_TYPEs, which is appropriate for C++.  */
2507   if ((type_quals & TYPE_QUAL_RESTRICT)
2508       && (!POINTER_TYPE_P (type)
2509           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type))))
2510     {
2511       error ("invalid use of %<restrict%>");
2512       type_quals &= ~TYPE_QUAL_RESTRICT;
2513     }
2514
2515   return build_qualified_type (type, type_quals);
2516 }
2517
2518 /* Apply the TYPE_QUALS to the new DECL.  */
2519
2520 void
2521 c_apply_type_quals_to_decl (int type_quals, tree decl)
2522 {
2523   tree type = TREE_TYPE (decl);
2524
2525   if (type == error_mark_node)
2526     return;
2527
2528   if (((type_quals & TYPE_QUAL_CONST)
2529        || (type && TREE_CODE (type) == REFERENCE_TYPE))
2530       /* An object declared 'const' is only readonly after it is
2531          initialized.  We don't have any way of expressing this currently,
2532          so we need to be conservative and unset TREE_READONLY for types
2533          with constructors.  Otherwise aliasing code will ignore stores in
2534          an inline constructor.  */
2535       && !(type && TYPE_NEEDS_CONSTRUCTING (type)))
2536     TREE_READONLY (decl) = 1;
2537   if (type_quals & TYPE_QUAL_VOLATILE)
2538     {
2539       TREE_SIDE_EFFECTS (decl) = 1;
2540       TREE_THIS_VOLATILE (decl) = 1;
2541     }
2542   if (type_quals & TYPE_QUAL_RESTRICT)
2543     {
2544       while (type && TREE_CODE (type) == ARRAY_TYPE)
2545         /* Allow 'restrict' on arrays of pointers.
2546            FIXME currently we just ignore it.  */
2547         type = TREE_TYPE (type);
2548       if (!type
2549           || !POINTER_TYPE_P (type)
2550           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))
2551         error ("invalid use of %<restrict%>");
2552       else if (flag_strict_aliasing && type == TREE_TYPE (decl))
2553         /* Indicate we need to make a unique alias set for this pointer.
2554            We can't do it here because it might be pointing to an
2555            incomplete type.  */
2556         DECL_POINTER_ALIAS_SET (decl) = -2;
2557     }
2558 }
2559
2560 /* Hash function for the problem of multiple type definitions in
2561    different files.  This must hash all types that will compare
2562    equal via comptypes to the same value.  In practice it hashes
2563    on some of the simple stuff and leaves the details to comptypes.  */
2564
2565 static hashval_t
2566 c_type_hash (const void *p)
2567 {
2568   int i = 0;
2569   int shift, size;
2570   tree t = (tree) p;
2571   tree t2;
2572   switch (TREE_CODE (t))
2573     {
2574     /* For pointers, hash on pointee type plus some swizzling.  */
2575     case POINTER_TYPE:
2576       return c_type_hash (TREE_TYPE (t)) ^ 0x3003003;
2577     /* Hash on number of elements and total size.  */
2578     case ENUMERAL_TYPE:
2579       shift = 3;
2580       t2 = TYPE_VALUES (t);
2581       break;
2582     case RECORD_TYPE:
2583       shift = 0;
2584       t2 = TYPE_FIELDS (t);
2585       break;
2586     case QUAL_UNION_TYPE:
2587       shift = 1;
2588       t2 = TYPE_FIELDS (t);
2589       break;
2590     case UNION_TYPE:
2591       shift = 2;
2592       t2 = TYPE_FIELDS (t);
2593       break;
2594     default:
2595       gcc_unreachable ();
2596     }
2597   for (; t2; t2 = TREE_CHAIN (t2))
2598     i++;
2599   size = TREE_INT_CST_LOW (TYPE_SIZE (t));
2600   return ((size << 24) | (i << shift));
2601 }
2602
2603 static GTY((param_is (union tree_node))) htab_t type_hash_table;
2604
2605 /* Return the typed-based alias set for T, which may be an expression
2606    or a type.  Return -1 if we don't do anything special.  */
2607
2608 HOST_WIDE_INT
2609 c_common_get_alias_set (tree t)
2610 {
2611   tree u;
2612   PTR *slot;
2613
2614   /* Permit type-punning when accessing a union, provided the access
2615      is directly through the union.  For example, this code does not
2616      permit taking the address of a union member and then storing
2617      through it.  Even the type-punning allowed here is a GCC
2618      extension, albeit a common and useful one; the C standard says
2619      that such accesses have implementation-defined behavior.  */
2620   for (u = t;
2621        TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
2622        u = TREE_OPERAND (u, 0))
2623     if (TREE_CODE (u) == COMPONENT_REF
2624         && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
2625       return 0;
2626
2627   /* That's all the expressions we handle specially.  */
2628   if (!TYPE_P (t))
2629     return -1;
2630
2631   /* The C standard guarantees that any object may be accessed via an
2632      lvalue that has character type.  */
2633   if (t == char_type_node
2634       || t == signed_char_type_node
2635       || t == unsigned_char_type_node)
2636     return 0;
2637
2638   /* If it has the may_alias attribute, it can alias anything.  */
2639   if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (t)))
2640     return 0;
2641
2642   /* The C standard specifically allows aliasing between signed and
2643      unsigned variants of the same type.  We treat the signed
2644      variant as canonical.  */
2645   if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t))
2646     {
2647       tree t1 = c_common_signed_type (t);
2648
2649       /* t1 == t can happen for boolean nodes which are always unsigned.  */
2650       if (t1 != t)
2651         return get_alias_set (t1);
2652     }
2653   else if (POINTER_TYPE_P (t))
2654     {
2655       tree t1;
2656
2657       /* Unfortunately, there is no canonical form of a pointer type.
2658          In particular, if we have `typedef int I', then `int *', and
2659          `I *' are different types.  So, we have to pick a canonical
2660          representative.  We do this below.
2661
2662          Technically, this approach is actually more conservative that
2663          it needs to be.  In particular, `const int *' and `int *'
2664          should be in different alias sets, according to the C and C++
2665          standard, since their types are not the same, and so,
2666          technically, an `int **' and `const int **' cannot point at
2667          the same thing.
2668
2669          But, the standard is wrong.  In particular, this code is
2670          legal C++:
2671
2672             int *ip;
2673             int **ipp = &ip;
2674             const int* const* cipp = ipp;
2675
2676          And, it doesn't make sense for that to be legal unless you
2677          can dereference IPP and CIPP.  So, we ignore cv-qualifiers on
2678          the pointed-to types.  This issue has been reported to the
2679          C++ committee.  */
2680       t1 = build_type_no_quals (t);
2681       if (t1 != t)
2682         return get_alias_set (t1);
2683     }
2684
2685   /* Handle the case of multiple type nodes referring to "the same" type,
2686      which occurs with IMA.  These share an alias set.  FIXME:  Currently only
2687      C90 is handled.  (In C99 type compatibility is not transitive, which
2688      complicates things mightily. The alias set splay trees can theoretically
2689      represent this, but insertion is tricky when you consider all the
2690      different orders things might arrive in.) */
2691
2692   if (c_language != clk_c || flag_isoc99)
2693     return -1;
2694
2695   /* Save time if there's only one input file.  */
2696   if (num_in_fnames == 1)
2697     return -1;
2698
2699   /* Pointers need special handling if they point to any type that
2700      needs special handling (below).  */
2701   if (TREE_CODE (t) == POINTER_TYPE)
2702     {
2703       tree t2;
2704       /* Find bottom type under any nested POINTERs.  */
2705       for (t2 = TREE_TYPE (t);
2706      TREE_CODE (t2) == POINTER_TYPE;
2707      t2 = TREE_TYPE (t2))
2708   ;
2709       if (TREE_CODE (t2) != RECORD_TYPE
2710     && TREE_CODE (t2) != ENUMERAL_TYPE
2711     && TREE_CODE (t2) != QUAL_UNION_TYPE
2712     && TREE_CODE (t2) != UNION_TYPE)
2713   return -1;
2714       if (TYPE_SIZE (t2) == 0)
2715   return -1;
2716     }
2717   /* These are the only cases that need special handling.  */
2718   if (TREE_CODE (t) != RECORD_TYPE
2719       && TREE_CODE (t) != ENUMERAL_TYPE
2720       && TREE_CODE (t) != QUAL_UNION_TYPE
2721       && TREE_CODE (t) != UNION_TYPE
2722       && TREE_CODE (t) != POINTER_TYPE)
2723     return -1;
2724   /* Undefined? */
2725   if (TYPE_SIZE (t) == 0)
2726     return -1;
2727
2728   /* Look up t in hash table.  Only one of the compatible types within each
2729      alias set is recorded in the table.  */
2730   if (!type_hash_table)
2731     type_hash_table = htab_create_ggc (1021, c_type_hash,
2732             (htab_eq) lang_hooks.types_compatible_p,
2733             NULL);
2734   slot = htab_find_slot (type_hash_table, t, INSERT);
2735   if (*slot != NULL)
2736     {
2737       TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot);
2738       return TYPE_ALIAS_SET ((tree)*slot);
2739     }
2740   else
2741     /* Our caller will assign and record (in t) a new alias set; all we need
2742        to do is remember t in the hash table.  */
2743     *slot = t;
2744
2745   return -1;
2746 }
2747 \f
2748 /* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where the
2749    second parameter indicates which OPERATOR is being applied.  The COMPLAIN
2750    flag controls whether we should diagnose possibly ill-formed
2751    constructs or not.  */
2752 tree
2753 c_sizeof_or_alignof_type (tree type, enum tree_code op, int complain)
2754 {
2755   const char *op_name;
2756   tree value = NULL;
2757   enum tree_code type_code = TREE_CODE (type);
2758
2759   gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
2760   op_name = op == SIZEOF_EXPR ? "sizeof" : "__alignof__";
2761
2762   if (type_code == FUNCTION_TYPE)
2763     {
2764       if (op == SIZEOF_EXPR)
2765         {
2766           if (complain && (pedantic || warn_pointer_arith))
2767             pedwarn ("invalid application of %<sizeof%> to a function type");
2768           value = size_one_node;
2769         }
2770       else
2771         value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);
2772     }
2773   else if (type_code == VOID_TYPE || type_code == ERROR_MARK)
2774     {
2775       if (type_code == VOID_TYPE
2776           && complain && (pedantic || warn_pointer_arith))
2777         pedwarn ("invalid application of %qs to a void type", op_name);
2778       value = size_one_node;
2779     }
2780   else if (!COMPLETE_TYPE_P (type))
2781     {
2782       if (complain)
2783         error ("invalid application of %qs to incomplete type %qT ",
2784                op_name, type);
2785       value = size_zero_node;
2786     }
2787   else
2788     {
2789       if (op == (enum tree_code) SIZEOF_EXPR)
2790         /* Convert in case a char is more than one unit.  */
2791         value = size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
2792                             size_int (TYPE_PRECISION (char_type_node)
2793                                       / BITS_PER_UNIT));
2794       else
2795         value = size_int (TYPE_ALIGN_UNIT (type));
2796     }
2797
2798   /* VALUE will have an integer type with TYPE_IS_SIZETYPE set.
2799      TYPE_IS_SIZETYPE means that certain things (like overflow) will
2800      never happen.  However, this node should really have type
2801      `size_t', which is just a typedef for an ordinary integer type.  */
2802   value = fold (build1 (NOP_EXPR, size_type_node, value));
2803   gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value)));
2804
2805   return value;
2806 }
2807
2808 /* Implement the __alignof keyword: Return the minimum required
2809    alignment of EXPR, measured in bytes.  For VAR_DECL's and
2810    FIELD_DECL's return DECL_ALIGN (which can be set from an
2811    "aligned" __attribute__ specification).  */
2812
2813 tree
2814 c_alignof_expr (tree expr)
2815 {
2816   tree t;
2817
2818   if (TREE_CODE (expr) == VAR_DECL)
2819     t = size_int (DECL_ALIGN_UNIT (expr));
2820
2821   else if (TREE_CODE (expr) == COMPONENT_REF
2822            && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1)))
2823     {
2824       error ("%<__alignof%> applied to a bit-field");
2825       t = size_one_node;
2826     }
2827   else if (TREE_CODE (expr) == COMPONENT_REF
2828            && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL)
2829     t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1)));
2830
2831   else if (TREE_CODE (expr) == INDIRECT_REF)
2832     {
2833       tree t = TREE_OPERAND (expr, 0);
2834       tree best = t;
2835       int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
2836
2837       while (TREE_CODE (t) == NOP_EXPR
2838              && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE)
2839         {
2840           int thisalign;
2841
2842           t = TREE_OPERAND (t, 0);
2843           thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
2844           if (thisalign > bestalign)
2845             best = t, bestalign = thisalign;
2846         }
2847       return c_alignof (TREE_TYPE (TREE_TYPE (best)));
2848     }
2849   else
2850     return c_alignof (TREE_TYPE (expr));
2851
2852   return fold (build1 (NOP_EXPR, size_type_node, t));
2853 }
2854 \f
2855 /* Handle C and C++ default attributes.  */
2856
2857 enum built_in_attribute
2858 {
2859 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
2860 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
2861 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
2862 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
2863 #include "builtin-attrs.def"
2864 #undef DEF_ATTR_NULL_TREE
2865 #undef DEF_ATTR_INT
2866 #undef DEF_ATTR_IDENT
2867 #undef DEF_ATTR_TREE_LIST
2868   ATTR_LAST
2869 };
2870
2871 static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
2872
2873 static void c_init_attributes (void);
2874
2875 /* Build tree nodes and builtin functions common to both C and C++ language
2876    frontends.  */
2877
2878 void
2879 c_common_nodes_and_builtins (void)
2880 {
2881   enum builtin_type
2882   {
2883 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
2884 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
2885 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
2886 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
2887 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
2888 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
2889 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
2890 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
2891 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
2892 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
2893 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
2894 #include "builtin-types.def"
2895 #undef DEF_PRIMITIVE_TYPE
2896 #undef DEF_FUNCTION_TYPE_0
2897 #undef DEF_FUNCTION_TYPE_1
2898 #undef DEF_FUNCTION_TYPE_2
2899 #undef DEF_FUNCTION_TYPE_3
2900 #undef DEF_FUNCTION_TYPE_4
2901 #undef DEF_FUNCTION_TYPE_VAR_0
2902 #undef DEF_FUNCTION_TYPE_VAR_1
2903 #undef DEF_FUNCTION_TYPE_VAR_2
2904 #undef DEF_FUNCTION_TYPE_VAR_3
2905 #undef DEF_POINTER_TYPE
2906     BT_LAST
2907   };
2908
2909   typedef enum builtin_type builtin_type;
2910
2911   tree builtin_types[(int) BT_LAST];
2912   int wchar_type_size;
2913   tree array_domain_type;
2914   tree va_list_ref_type_node;
2915   tree va_list_arg_type_node;
2916
2917   /* Define `int' and `char' first so that dbx will output them first.  */
2918   record_builtin_type (RID_INT, NULL, integer_type_node);
2919   record_builtin_type (RID_CHAR, "char", char_type_node);
2920
2921   /* `signed' is the same as `int'.  FIXME: the declarations of "signed",
2922      "unsigned long", "long long unsigned" and "unsigned short" were in C++
2923      but not C.  Are the conditionals here needed?  */
2924   if (c_dialect_cxx ())
2925     record_builtin_type (RID_SIGNED, NULL, integer_type_node);
2926   record_builtin_type (RID_LONG, "long int", long_integer_type_node);
2927   record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
2928   record_builtin_type (RID_MAX, "long unsigned int",
2929                        long_unsigned_type_node);
2930   if (c_dialect_cxx ())
2931     record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
2932   record_builtin_type (RID_MAX, "long long int",
2933                        long_long_integer_type_node);
2934   record_builtin_type (RID_MAX, "long long unsigned int",
2935                        long_long_unsigned_type_node);
2936   if (c_dialect_cxx ())
2937     record_builtin_type (RID_MAX, "long long unsigned",
2938                          long_long_unsigned_type_node);
2939   record_builtin_type (RID_SHORT, "short int", short_integer_type_node);
2940   record_builtin_type (RID_MAX, "short unsigned int",
2941                        short_unsigned_type_node);
2942   if (c_dialect_cxx ())
2943     record_builtin_type (RID_MAX, "unsigned short",
2944                          short_unsigned_type_node);
2945
2946   /* Define both `signed char' and `unsigned char'.  */
2947   record_builtin_type (RID_MAX, "signed char", signed_char_type_node);
2948   record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node);
2949
2950   /* These are types that c_common_type_for_size and
2951      c_common_type_for_mode use.  */
2952   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
2953                                          intQI_type_node));
2954   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
2955                                          intHI_type_node));
2956   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
2957                                          intSI_type_node));
2958   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
2959                                          intDI_type_node));
2960 #if HOST_BITS_PER_WIDE_INT >= 64
2961   if (targetm.scalar_mode_supported_p (TImode))
2962     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
2963                                            get_identifier ("__int128_t"),
2964                                            intTI_type_node));
2965 #endif
2966   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
2967                                          unsigned_intQI_type_node));
2968   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
2969                                          unsigned_intHI_type_node));
2970   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
2971                                          unsigned_intSI_type_node));
2972   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
2973                                          unsigned_intDI_type_node));
2974 #if HOST_BITS_PER_WIDE_INT >= 64
2975   if (targetm.scalar_mode_supported_p (TImode))
2976     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
2977                                            get_identifier ("__uint128_t"),
2978                                            unsigned_intTI_type_node));
2979 #endif
2980
2981   /* Create the widest literal types.  */
2982   widest_integer_literal_type_node
2983     = make_signed_type (HOST_BITS_PER_WIDE_INT * 2);
2984   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
2985                                          widest_integer_literal_type_node));
2986
2987   widest_unsigned_literal_type_node
2988     = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2);
2989   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
2990                                          widest_unsigned_literal_type_node));
2991
2992   /* `unsigned long' is the standard type for sizeof.
2993      Note that stddef.h uses `unsigned long',
2994      and this must agree, even if long and int are the same size.  */
2995   size_type_node =
2996     TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE)));
2997   signed_size_type_node = c_common_signed_type (size_type_node);
2998   set_sizetype (size_type_node);
2999
3000   pid_type_node =
3001     TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE)));
3002
3003   build_common_tree_nodes_2 (flag_short_double);
3004
3005   record_builtin_type (RID_FLOAT, NULL, float_type_node);
3006   record_builtin_type (RID_DOUBLE, NULL, double_type_node);
3007   record_builtin_type (RID_MAX, "long double", long_double_type_node);
3008
3009   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3010                                          get_identifier ("complex int"),
3011                                          complex_integer_type_node));
3012   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3013                                          get_identifier ("complex float"),
3014                                          complex_float_type_node));
3015   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3016                                          get_identifier ("complex double"),
3017                                          complex_double_type_node));
3018   lang_hooks.decls.pushdecl
3019     (build_decl (TYPE_DECL, get_identifier ("complex long double"),
3020                  complex_long_double_type_node));
3021
3022   if (c_dialect_cxx ())
3023     /* For C++, make fileptr_type_node a distinct void * type until
3024        FILE type is defined.  */
3025     fileptr_type_node = build_variant_type_copy (ptr_type_node);
3026
3027   record_builtin_type (RID_VOID, NULL, void_type_node);
3028
3029   /* This node must not be shared.  */
3030   void_zero_node = make_node (INTEGER_CST);
3031   TREE_TYPE (void_zero_node) = void_type_node;
3032
3033   void_list_node = build_void_list_node ();
3034
3035   /* Make a type to be the domain of a few array types
3036      whose domains don't really matter.
3037      200 is small enough that it always fits in size_t
3038      and large enough that it can hold most function names for the
3039      initializations of __FUNCTION__ and __PRETTY_FUNCTION__.  */
3040   array_domain_type = build_index_type (size_int (200));
3041
3042   /* Make a type for arrays of characters.
3043      With luck nothing will ever really depend on the length of this
3044      array type.  */
3045   char_array_type_node
3046     = build_array_type (char_type_node, array_domain_type);
3047
3048   /* Likewise for arrays of ints.  */
3049   int_array_type_node
3050     = build_array_type (integer_type_node, array_domain_type);
3051
3052   string_type_node = build_pointer_type (char_type_node);
3053   const_string_type_node
3054     = build_pointer_type (build_qualified_type
3055                           (char_type_node, TYPE_QUAL_CONST));
3056
3057   /* This is special for C++ so functions can be overloaded.  */
3058   wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE);
3059   wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node));
3060   wchar_type_size = TYPE_PRECISION (wchar_type_node);
3061   if (c_dialect_cxx ())
3062     {
3063       if (TYPE_UNSIGNED (wchar_type_node))
3064         wchar_type_node = make_unsigned_type (wchar_type_size);
3065       else
3066         wchar_type_node = make_signed_type (wchar_type_size);
3067       record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node);
3068     }
3069   else
3070     {
3071       signed_wchar_type_node = c_common_signed_type (wchar_type_node);
3072       unsigned_wchar_type_node = c_common_unsigned_type (wchar_type_node);
3073     }
3074
3075   /* This is for wide string constants.  */
3076   wchar_array_type_node
3077     = build_array_type (wchar_type_node, array_domain_type);
3078
3079   wint_type_node =
3080     TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE)));
3081
3082   intmax_type_node =
3083     TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE)));
3084   uintmax_type_node =
3085     TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE)));
3086
3087   default_function_type = build_function_type (integer_type_node, NULL_TREE);
3088   ptrdiff_type_node
3089     = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE)));
3090   unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node);
3091
3092   lang_hooks.decls.pushdecl
3093     (build_decl (TYPE_DECL, get_identifier ("__builtin_va_list"),
3094                  va_list_type_node));
3095
3096   if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
3097     {
3098       va_list_arg_type_node = va_list_ref_type_node =
3099         build_pointer_type (TREE_TYPE (va_list_type_node));
3100     }
3101   else
3102     {
3103       va_list_arg_type_node = va_list_type_node;
3104       va_list_ref_type_node = build_reference_type (va_list_type_node);
3105     }
3106
3107 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
3108   builtin_types[(int) ENUM] = VALUE;
3109 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN)               \
3110   builtin_types[(int) ENUM]                             \
3111     = build_function_type (builtin_types[(int) RETURN], \
3112                            void_list_node);
3113 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1)                         \
3114   builtin_types[(int) ENUM]                                             \
3115     = build_function_type (builtin_types[(int) RETURN],                 \
3116                            tree_cons (NULL_TREE,                        \
3117                                       builtin_types[(int) ARG1],        \
3118                                       void_list_node));
3119 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2)   \
3120   builtin_types[(int) ENUM]                             \
3121     = build_function_type                               \
3122       (builtin_types[(int) RETURN],                     \
3123        tree_cons (NULL_TREE,                            \
3124                   builtin_types[(int) ARG1],            \
3125                   tree_cons (NULL_TREE,                 \
3126                              builtin_types[(int) ARG2], \
3127                              void_list_node)));
3128 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3)              \
3129   builtin_types[(int) ENUM]                                              \
3130     = build_function_type                                                \
3131       (builtin_types[(int) RETURN],                                      \
3132        tree_cons (NULL_TREE,                                             \
3133                   builtin_types[(int) ARG1],                             \
3134                   tree_cons (NULL_TREE,                                  \
3135                              builtin_types[(int) ARG2],                  \
3136                              tree_cons (NULL_TREE,                       \
3137                                         builtin_types[(int) ARG3],       \
3138                                         void_list_node))));
3139 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4)       \
3140   builtin_types[(int) ENUM]                                             \
3141     = build_function_type                                               \
3142       (builtin_types[(int) RETURN],                                     \
3143        tree_cons (NULL_TREE,                                            \
3144                   builtin_types[(int) ARG1],                            \
3145                   tree_cons (NULL_TREE,                                 \
3146                              builtin_types[(int) ARG2],                 \
3147                              tree_cons                                  \
3148                              (NULL_TREE,                                \
3149                               builtin_types[(int) ARG3],                \
3150                               tree_cons (NULL_TREE,                     \
3151                                          builtin_types[(int) ARG4],     \
3152                                          void_list_node)))));
3153 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN)                           \
3154   builtin_types[(int) ENUM]                                             \
3155     = build_function_type (builtin_types[(int) RETURN], NULL_TREE);
3156 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1)                      \
3157    builtin_types[(int) ENUM]                                             \
3158     = build_function_type (builtin_types[(int) RETURN],          \
3159                            tree_cons (NULL_TREE,                         \
3160                                       builtin_types[(int) ARG1],         \
3161                                       NULL_TREE));
3162
3163 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2)       \
3164    builtin_types[(int) ENUM]                                    \
3165     = build_function_type                                       \
3166       (builtin_types[(int) RETURN],                             \
3167        tree_cons (NULL_TREE,                                    \
3168                   builtin_types[(int) ARG1],                    \
3169                   tree_cons (NULL_TREE,                         \
3170                              builtin_types[(int) ARG2],         \
3171                              NULL_TREE)));
3172
3173 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3)         \
3174    builtin_types[(int) ENUM]                                            \
3175     = build_function_type                                               \
3176       (builtin_types[(int) RETURN],                                     \
3177        tree_cons (NULL_TREE,                                            \
3178                   builtin_types[(int) ARG1],                            \
3179                   tree_cons (NULL_TREE,                                 \
3180                              builtin_types[(int) ARG2],                 \
3181                              tree_cons (NULL_TREE,                      \
3182                                         builtin_types[(int) ARG3],      \
3183                                         NULL_TREE))));
3184
3185 #define DEF_POINTER_TYPE(ENUM, TYPE)                    \
3186   builtin_types[(int) ENUM]                             \
3187     = build_pointer_type (builtin_types[(int) TYPE]);
3188 #include "builtin-types.def"
3189 #undef DEF_PRIMITIVE_TYPE
3190 #undef DEF_FUNCTION_TYPE_1
3191 #undef DEF_FUNCTION_TYPE_2
3192 #undef DEF_FUNCTION_TYPE_3
3193 #undef DEF_FUNCTION_TYPE_4
3194 #undef DEF_FUNCTION_TYPE_VAR_0
3195 #undef DEF_FUNCTION_TYPE_VAR_1
3196 #undef DEF_FUNCTION_TYPE_VAR_2
3197 #undef DEF_FUNCTION_TYPE_VAR_3
3198 #undef DEF_POINTER_TYPE
3199
3200   c_init_attributes ();
3201
3202 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE,                   \
3203                     BOTH_P, FALLBACK_P, NONANSI_P, ATTRS, IMPLICIT)     \
3204   if (NAME)                                                             \
3205     {                                                                   \
3206       tree decl;                                                        \
3207                                                                         \
3208       gcc_assert (!strncmp (NAME, "__builtin_",                         \
3209                             strlen ("__builtin_")));                    \
3210                                                                         \
3211       if (!BOTH_P)                                                      \
3212         decl = lang_hooks.builtin_function (NAME, builtin_types[TYPE],  \
3213                                  ENUM,                                  \
3214                                  CLASS,                                 \
3215                                  (FALLBACK_P                            \
3216                                   ? (NAME + strlen ("__builtin_"))      \
3217                                   : NULL),                              \
3218                                  built_in_attributes[(int) ATTRS]);     \
3219       else                                                              \
3220         decl = builtin_function_2 (NAME,                                \
3221                                    NAME + strlen ("__builtin_"),        \
3222                                    builtin_types[TYPE],                 \
3223                                    builtin_types[LIBTYPE],              \
3224                                    ENUM,                                \
3225                                    CLASS,                               \
3226                                    FALLBACK_P,                          \
3227                                    NONANSI_P,                           \
3228                                    built_in_attributes[(int) ATTRS]);   \
3229                                                                         \
3230       built_in_decls[(int) ENUM] = decl;                                \
3231       if (IMPLICIT)                                                     \
3232         implicit_built_in_decls[(int) ENUM] = decl;                     \
3233     }
3234 #include "builtins.def"
3235 #undef DEF_BUILTIN
3236
3237   targetm.init_builtins ();
3238   if (flag_mudflap)
3239     mudflap_init ();
3240
3241   main_identifier_node = get_identifier ("main");
3242 }
3243
3244 /* Look up the function in built_in_decls that corresponds to DECL
3245    and set ASMSPEC as its user assembler name.  DECL must be a
3246    function decl that declares a builtin. */
3247
3248 void
3249 set_builtin_user_assembler_name (tree decl, const char *asmspec)
3250 {
3251   tree builtin;
3252   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
3253               && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
3254               && asmspec != 0);
3255
3256   builtin = built_in_decls [DECL_FUNCTION_CODE (decl)];
3257   set_user_assembler_name (builtin, asmspec);
3258   if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMCPY)
3259     init_block_move_fn (asmspec);
3260   else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMSET)
3261     init_block_clear_fn (asmspec);
3262 }
3263
3264 tree
3265 build_va_arg (tree expr, tree type)
3266 {
3267   return build1 (VA_ARG_EXPR, type, expr);
3268 }
3269
3270
3271 /* Linked list of disabled built-in functions.  */
3272
3273 typedef struct disabled_builtin
3274 {
3275   const char *name;
3276   struct disabled_builtin *next;
3277 } disabled_builtin;
3278 static disabled_builtin *disabled_builtins = NULL;
3279
3280 static bool builtin_function_disabled_p (const char *);
3281
3282 /* Disable a built-in function specified by -fno-builtin-NAME.  If NAME
3283    begins with "__builtin_", give an error.  */
3284
3285 void
3286 disable_builtin_function (const char *name)
3287 {
3288   if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
3289     error ("cannot disable built-in function %qs", name);
3290   else
3291     {
3292       disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin);
3293       new_disabled_builtin->name = name;
3294       new_disabled_builtin->next = disabled_builtins;
3295       disabled_builtins = new_disabled_builtin;
3296     }
3297 }
3298
3299
3300 /* Return true if the built-in function NAME has been disabled, false
3301    otherwise.  */
3302
3303 static bool
3304 builtin_function_disabled_p (const char *name)
3305 {
3306   disabled_builtin *p;
3307   for (p = disabled_builtins; p != NULL; p = p->next)
3308     {
3309       if (strcmp (name, p->name) == 0)
3310         return true;
3311     }
3312   return false;
3313 }
3314
3315
3316 /* Possibly define a builtin function with one or two names.  BUILTIN_NAME
3317    is an __builtin_-prefixed name; NAME is the ordinary name; one or both
3318    of these may be NULL (though both being NULL is useless).
3319    BUILTIN_TYPE is the type of the __builtin_-prefixed function;
3320    TYPE is the type of the function with the ordinary name.  These
3321    may differ if the ordinary name is declared with a looser type to avoid
3322    conflicts with headers.  FUNCTION_CODE and CL are as for
3323    builtin_function.  If LIBRARY_NAME_P is nonzero, NAME is passed as
3324    the LIBRARY_NAME parameter to builtin_function when declaring BUILTIN_NAME.
3325    If NONANSI_P is true, the name NAME is treated as a non-ANSI name;
3326    ATTRS is the tree list representing the builtin's function attributes.
3327    Returns the declaration of BUILTIN_NAME, if any, otherwise
3328    the declaration of NAME.  Does not declare NAME if flag_no_builtin,
3329    or if NONANSI_P and flag_no_nonansi_builtin.  */
3330
3331 static tree
3332 builtin_function_2 (const char *builtin_name, const char *name,
3333                     tree builtin_type, tree type,
3334                     enum built_in_function function_code,
3335                     enum built_in_class cl, int library_name_p,
3336                     bool nonansi_p, tree attrs)
3337 {
3338   tree bdecl = NULL_TREE;
3339   tree decl = NULL_TREE;
3340
3341   if (builtin_name != 0)
3342     bdecl = lang_hooks.builtin_function (builtin_name, builtin_type,
3343                                          function_code, cl,
3344                                          library_name_p ? name : NULL, attrs);
3345
3346   if (name != 0 && !flag_no_builtin && !builtin_function_disabled_p (name)
3347       && !(nonansi_p && flag_no_nonansi_builtin))
3348     decl = lang_hooks.builtin_function (name, type, function_code, cl,
3349                                         NULL, attrs);
3350
3351   return (bdecl != 0 ? bdecl : decl);
3352 }
3353 \f
3354 /* Nonzero if the type T promotes to int.  This is (nearly) the
3355    integral promotions defined in ISO C99 6.3.1.1/2.  */
3356
3357 bool
3358 c_promoting_integer_type_p (tree t)
3359 {
3360   switch (TREE_CODE (t))
3361     {
3362     case INTEGER_TYPE:
3363       return (TYPE_MAIN_VARIANT (t) == char_type_node
3364               || TYPE_MAIN_VARIANT (t) == signed_char_type_node
3365               || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node
3366               || TYPE_MAIN_VARIANT (t) == short_integer_type_node
3367               || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node
3368               || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node));
3369
3370     case ENUMERAL_TYPE:
3371       /* ??? Technically all enumerations not larger than an int
3372          promote to an int.  But this is used along code paths
3373          that only want to notice a size change.  */
3374       return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node);
3375
3376     case BOOLEAN_TYPE:
3377       return 1;
3378
3379     default:
3380       return 0;
3381     }
3382 }
3383
3384 /* Return 1 if PARMS specifies a fixed number of parameters
3385    and none of their types is affected by default promotions.  */
3386
3387 int
3388 self_promoting_args_p (tree parms)
3389 {
3390   tree t;
3391   for (t = parms; t; t = TREE_CHAIN (t))
3392     {
3393       tree type = TREE_VALUE (t);
3394
3395       if (TREE_CHAIN (t) == 0 && type != void_type_node)
3396         return 0;
3397
3398       if (type == 0)
3399         return 0;
3400
3401       if (TYPE_MAIN_VARIANT (type) == float_type_node)
3402         return 0;
3403
3404       if (c_promoting_integer_type_p (type))
3405         return 0;
3406     }
3407   return 1;
3408 }
3409
3410 /* Recursively examines the array elements of TYPE, until a non-array
3411    element type is found.  */
3412
3413 tree
3414 strip_array_types (tree type)
3415 {
3416   while (TREE_CODE (type) == ARRAY_TYPE)
3417     type = TREE_TYPE (type);
3418
3419   return type;
3420 }
3421
3422 /* Recursively remove any '*' or '&' operator from TYPE.  */
3423 tree
3424 strip_pointer_operator (tree t)
3425 {
3426   while (POINTER_TYPE_P (t))
3427     t = TREE_TYPE (t);
3428   return t;
3429 }
3430
3431 /* Used to compare case labels.  K1 and K2 are actually tree nodes
3432    representing case labels, or NULL_TREE for a `default' label.
3433    Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
3434    K2, and 0 if K1 and K2 are equal.  */
3435
3436 int
3437 case_compare (splay_tree_key k1, splay_tree_key k2)
3438 {
3439   /* Consider a NULL key (such as arises with a `default' label) to be
3440      smaller than anything else.  */
3441   if (!k1)
3442     return k2 ? -1 : 0;
3443   else if (!k2)
3444     return k1 ? 1 : 0;
3445
3446   return tree_int_cst_compare ((tree) k1, (tree) k2);
3447 }
3448
3449 /* Process a case label for the range LOW_VALUE ... HIGH_VALUE.  If
3450    LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is
3451    actually a `default' label.  If only HIGH_VALUE is NULL_TREE, then
3452    case label was declared using the usual C/C++ syntax, rather than
3453    the GNU case range extension.  CASES is a tree containing all the
3454    case ranges processed so far; COND is the condition for the
3455    switch-statement itself.  Returns the CASE_LABEL_EXPR created, or
3456    ERROR_MARK_NODE if no CASE_LABEL_EXPR is created.  */
3457
3458 tree
3459 c_add_case_label (splay_tree cases, tree cond, tree orig_type,
3460                   tree low_value, tree high_value)
3461 {
3462   tree type;
3463   tree label;
3464   tree case_label;
3465   splay_tree_node node;
3466
3467   /* Create the LABEL_DECL itself.  */
3468   label = create_artificial_label ();
3469
3470   /* If there was an error processing the switch condition, bail now
3471      before we get more confused.  */
3472   if (!cond || cond == error_mark_node)
3473     goto error_out;
3474
3475   if ((low_value && TREE_TYPE (low_value)
3476        && POINTER_TYPE_P (TREE_TYPE (low_value)))
3477       || (high_value && TREE_TYPE (high_value)
3478           && POINTER_TYPE_P (TREE_TYPE (high_value))))
3479     error ("pointers are not permitted as case values");
3480
3481   /* Case ranges are a GNU extension.  */
3482   if (high_value && pedantic)
3483     pedwarn ("range expressions in switch statements are non-standard");
3484
3485   type = TREE_TYPE (cond);
3486   if (low_value)
3487     {
3488       low_value = check_case_value (low_value);
3489       low_value = convert_and_check (type, low_value);
3490     }
3491   if (high_value)
3492     {
3493       high_value = check_case_value (high_value);
3494       high_value = convert_and_check (type, high_value);
3495     }
3496
3497   /* If an error has occurred, bail out now.  */
3498   if (low_value == error_mark_node || high_value == error_mark_node)
3499     goto error_out;
3500
3501   /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
3502      really a case range, even though it was written that way.  Remove
3503      the HIGH_VALUE to simplify later processing.  */
3504   if (tree_int_cst_equal (low_value, high_value))
3505     high_value = NULL_TREE;
3506   if (low_value && high_value
3507       && !tree_int_cst_lt (low_value, high_value))
3508     warning ("empty range specified");
3509
3510   /* See if the case is in range of the type of the original testing
3511      expression.  If both low_value and high_value are out of range,
3512      don't insert the case label and return NULL_TREE.  */
3513   if (low_value
3514       && !check_case_bounds (type, orig_type,
3515                              &low_value, high_value ? &high_value : NULL))
3516     return NULL_TREE;
3517
3518   /* Look up the LOW_VALUE in the table of case labels we already
3519      have.  */
3520   node = splay_tree_lookup (cases, (splay_tree_key) low_value);
3521   /* If there was not an exact match, check for overlapping ranges.
3522      There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
3523      that's a `default' label and the only overlap is an exact match.  */
3524   if (!node && (low_value || high_value))
3525     {
3526       splay_tree_node low_bound;
3527       splay_tree_node high_bound;
3528
3529       /* Even though there wasn't an exact match, there might be an
3530          overlap between this case range and another case range.
3531          Since we've (inductively) not allowed any overlapping case
3532          ranges, we simply need to find the greatest low case label
3533          that is smaller that LOW_VALUE, and the smallest low case
3534          label that is greater than LOW_VALUE.  If there is an overlap
3535          it will occur in one of these two ranges.  */
3536       low_bound = splay_tree_predecessor (cases,
3537                                           (splay_tree_key) low_value);
3538       high_bound = splay_tree_successor (cases,
3539                                          (splay_tree_key) low_value);
3540
3541       /* Check to see if the LOW_BOUND overlaps.  It is smaller than
3542          the LOW_VALUE, so there is no need to check unless the
3543          LOW_BOUND is in fact itself a case range.  */
3544       if (low_bound
3545           && CASE_HIGH ((tree) low_bound->value)
3546           && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
3547                                     low_value) >= 0)
3548         node = low_bound;
3549       /* Check to see if the HIGH_BOUND overlaps.  The low end of that
3550          range is bigger than the low end of the current range, so we
3551          are only interested if the current range is a real range, and
3552          not an ordinary case label.  */
3553       else if (high_bound
3554                && high_value
3555                && (tree_int_cst_compare ((tree) high_bound->key,
3556                                          high_value)
3557                    <= 0))
3558         node = high_bound;
3559     }
3560   /* If there was an overlap, issue an error.  */
3561   if (node)
3562     {
3563       tree duplicate = CASE_LABEL ((tree) node->value);
3564
3565       if (high_value)
3566         {
3567           error ("duplicate (or overlapping) case value");
3568           error ("%Jthis is the first entry overlapping that value", duplicate);
3569         }
3570       else if (low_value)
3571         {
3572           error ("duplicate case value") ;
3573           error ("%Jpreviously used here", duplicate);
3574         }
3575       else
3576         {
3577           error ("multiple default labels in one switch");
3578           error ("%Jthis is the first default label", duplicate);
3579         }
3580       goto error_out;
3581     }
3582
3583   /* Add a CASE_LABEL to the statement-tree.  */
3584   case_label = add_stmt (build_case_label (low_value, high_value, label));
3585   /* Register this case label in the splay tree.  */
3586   splay_tree_insert (cases,
3587                      (splay_tree_key) low_value,
3588                      (splay_tree_value) case_label);
3589
3590   return case_label;
3591
3592  error_out:
3593   /* Add a label so that the back-end doesn't think that the beginning of
3594      the switch is unreachable.  Note that we do not add a case label, as
3595      that just leads to duplicates and thence to aborts later on.  */
3596   if (!cases->root)
3597     {
3598       tree t = create_artificial_label ();
3599       add_stmt (build_stmt (LABEL_EXPR, t));
3600     }
3601   return error_mark_node;
3602 }
3603
3604 /* Subroutines of c_do_switch_warnings, called via splay_tree_foreach.
3605    Used to verify that case values match up with enumerator values.  */
3606
3607 static void
3608 match_case_to_enum_1 (tree key, tree type, tree label)
3609 {
3610   char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1];
3611
3612   /* ??? Not working too hard to print the double-word value.
3613      Should perhaps be done with %lwd in the diagnostic routines?  */
3614   if (TREE_INT_CST_HIGH (key) == 0)
3615     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED,
3616               TREE_INT_CST_LOW (key));
3617   else if (!TYPE_UNSIGNED (type)
3618            && TREE_INT_CST_HIGH (key) == -1
3619            && TREE_INT_CST_LOW (key) != 0)
3620     snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED,
3621               -TREE_INT_CST_LOW (key));
3622   else
3623     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX,
3624               TREE_INT_CST_HIGH (key), TREE_INT_CST_LOW (key));
3625
3626   if (TYPE_NAME (type) == 0)
3627     warning ("%Jcase value %qs not in enumerated type",
3628              CASE_LABEL (label), buf);
3629   else
3630     warning ("%Jcase value %qs not in enumerated type %qT",
3631              CASE_LABEL (label), buf, type);
3632 }
3633
3634 static int
3635 match_case_to_enum (splay_tree_node node, void *data)
3636 {
3637   tree label = (tree) node->value;
3638   tree type = (tree) data;
3639
3640   /* Skip default case.  */
3641   if (!CASE_LOW (label))
3642     return 0;
3643
3644   /* If TREE_ADDRESSABLE is not set, that means CASE_LOW did not appear
3645      when we did our enum->case scan.  Reset our scratch bit after.  */
3646   if (!TREE_ADDRESSABLE (label))
3647     match_case_to_enum_1 (CASE_LOW (label), type, label);
3648   else
3649     TREE_ADDRESSABLE (label) = 0;
3650
3651   /* If CASE_HIGH is non-null, we have a range.  Here we must search.
3652      Note that the old code in stmt.c did not check for the values in
3653      the range either, just the endpoints.  */
3654   if (CASE_HIGH (label))
3655     {
3656       tree chain, key = CASE_HIGH (label);
3657
3658       for (chain = TYPE_VALUES (type);
3659            chain && !tree_int_cst_equal (key, TREE_VALUE (chain));
3660            chain = TREE_CHAIN (chain))
3661         continue;
3662       if (!chain)
3663         match_case_to_enum_1 (key, type, label);
3664     }
3665
3666   return 0;
3667 }
3668
3669 /* Handle -Wswitch*.  Called from the front end after parsing the switch
3670    construct.  */
3671 /* ??? Should probably be somewhere generic, since other languages besides
3672    C and C++ would want this.  We'd want to agree on the datastructure,
3673    however, which is a problem.  Alternately, we operate on gimplified
3674    switch_exprs, which I don't especially like.  At the moment, however,
3675    C/C++ are the only tree-ssa languages that support enumerations at all,
3676    so the point is moot.  */
3677
3678 void
3679 c_do_switch_warnings (splay_tree cases, tree switch_stmt)
3680 {
3681   splay_tree_node default_node;
3682   location_t switch_location;
3683   tree type;
3684
3685   if (!warn_switch && !warn_switch_enum && !warn_switch_default)
3686     return;
3687
3688   if (EXPR_HAS_LOCATION (switch_stmt))
3689     switch_location = EXPR_LOCATION (switch_stmt);
3690   else
3691     switch_location = input_location;
3692
3693   type = SWITCH_STMT_TYPE (switch_stmt);
3694
3695   default_node = splay_tree_lookup (cases, (splay_tree_key) NULL);
3696   if (warn_switch_default && !default_node)
3697     warning ("%Hswitch missing default case", &switch_location);
3698
3699   /* If the switch expression was an enumerated type, check that
3700      exactly all enumeration literals are covered by the cases.
3701      The check is made when -Wswitch was specified and there is no
3702      default case, or when -Wswitch-enum was specified.  */
3703   if (((warn_switch && !default_node) || warn_switch_enum)
3704       && type && TREE_CODE (type) == ENUMERAL_TYPE
3705       && TREE_CODE (SWITCH_STMT_COND (switch_stmt)) != INTEGER_CST)
3706     {
3707       tree chain;
3708
3709       /* The time complexity here is O(N*lg(N)) worst case, but for the
3710          common case of monotonically increasing enumerators, it is
3711          O(N), since the nature of the splay tree will keep the next
3712          element adjacent to the root at all times.  */
3713
3714       for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain))
3715         {
3716           splay_tree_node node
3717             = splay_tree_lookup (cases, (splay_tree_key) TREE_VALUE (chain));
3718
3719           if (node)
3720             {
3721               /* Mark the CASE_LOW part of the case entry as seen, so
3722                  that we save time later.  Choose TREE_ADDRESSABLE
3723                  randomly as a bit that won't have been set to-date.  */
3724               tree label = (tree) node->value;
3725               TREE_ADDRESSABLE (label) = 1;
3726             }
3727           else
3728             {
3729               /* Warn if there are enumerators that don't correspond to
3730                  case expressions.  */
3731               warning ("%Henumeration value %qE not handled in switch",
3732                        &switch_location, TREE_PURPOSE (chain));
3733             }
3734         }
3735
3736       /* Warn if there are case expressions that don't correspond to
3737          enumerators.  This can occur since C and C++ don't enforce
3738          type-checking of assignments to enumeration variables.
3739
3740          The time complexity here is O(N**2) worst case, since we've
3741          not sorted the enumeration values.  However, in the absence
3742          of case ranges this is O(N), since all single cases that
3743          corresponded to enumerations have been marked above.  */
3744
3745       splay_tree_foreach (cases, match_case_to_enum, type);
3746     }
3747 }
3748
3749 /* Finish an expression taking the address of LABEL (an
3750    IDENTIFIER_NODE).  Returns an expression for the address.  */
3751
3752 tree
3753 finish_label_address_expr (tree label)
3754 {
3755   tree result;
3756
3757   if (pedantic)
3758     pedwarn ("taking the address of a label is non-standard");
3759
3760   if (label == error_mark_node)
3761     return error_mark_node;
3762
3763   label = lookup_label (label);
3764   if (label == NULL_TREE)
3765     result = null_pointer_node;
3766   else
3767     {
3768       TREE_USED (label) = 1;
3769       result = build1 (ADDR_EXPR, ptr_type_node, label);
3770       /* The current function in not necessarily uninlinable.
3771          Computed gotos are incompatible with inlining, but the value
3772          here could be used only in a diagnostic, for example.  */
3773     }
3774
3775   return result;
3776 }
3777
3778 /* Hook used by expand_expr to expand language-specific tree codes.  */
3779 /* The only things that should go here are bits needed to expand
3780    constant initializers.  Everything else should be handled by the
3781    gimplification routines.  */
3782
3783 rtx
3784 c_expand_expr (tree exp, rtx target, enum machine_mode tmode,
3785                int modifier /* Actually enum_modifier.  */,
3786                rtx *alt_rtl)
3787 {
3788   switch (TREE_CODE (exp))
3789     {
3790     case COMPOUND_LITERAL_EXPR:
3791       {
3792         /* Initialize the anonymous variable declared in the compound
3793            literal, then return the variable.  */
3794         tree decl = COMPOUND_LITERAL_EXPR_DECL (exp);
3795         emit_local_var (decl);
3796         return expand_expr_real (decl, target, tmode, modifier, alt_rtl);
3797       }
3798
3799     default:
3800       gcc_unreachable ();
3801     }
3802 }
3803
3804 /* Hook used by staticp to handle language-specific tree codes.  */
3805
3806 tree
3807 c_staticp (tree exp)
3808 {
3809   return (TREE_CODE (exp) == COMPOUND_LITERAL_EXPR
3810           && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp))
3811           ? exp : NULL);
3812 }
3813 \f
3814
3815 /* Given a boolean expression ARG, return a tree representing an increment
3816    or decrement (as indicated by CODE) of ARG.  The front end must check for
3817    invalid cases (e.g., decrement in C++).  */
3818 tree
3819 boolean_increment (enum tree_code code, tree arg)
3820 {
3821   tree val;
3822   tree true_res = boolean_true_node;
3823
3824   arg = stabilize_reference (arg);
3825   switch (code)
3826     {
3827     case PREINCREMENT_EXPR:
3828       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
3829       break;
3830     case POSTINCREMENT_EXPR:
3831       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
3832       arg = save_expr (arg);
3833       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
3834       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
3835       break;
3836     case PREDECREMENT_EXPR:
3837       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
3838                     invert_truthvalue (arg));
3839       break;
3840     case POSTDECREMENT_EXPR:
3841       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
3842                     invert_truthvalue (arg));
3843       arg = save_expr (arg);
3844       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
3845       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
3846       break;
3847     default:
3848       gcc_unreachable ();
3849     }
3850   TREE_SIDE_EFFECTS (val) = 1;
3851   return val;
3852 }
3853 \f
3854 /* Built-in macros for stddef.h, that require macros defined in this
3855    file.  */
3856 void
3857 c_stddef_cpp_builtins(void)
3858 {
3859   builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0);
3860   builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0);
3861   builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0);
3862   builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0);
3863   builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0);
3864   builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0);
3865 }
3866
3867 static void
3868 c_init_attributes (void)
3869 {
3870   /* Fill in the built_in_attributes array.  */
3871 #define DEF_ATTR_NULL_TREE(ENUM)                                \
3872   built_in_attributes[(int) ENUM] = NULL_TREE;
3873 #define DEF_ATTR_INT(ENUM, VALUE)                               \
3874   built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
3875 #define DEF_ATTR_IDENT(ENUM, STRING)                            \
3876   built_in_attributes[(int) ENUM] = get_identifier (STRING);
3877 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
3878   built_in_attributes[(int) ENUM]                       \
3879     = tree_cons (built_in_attributes[(int) PURPOSE],    \
3880                  built_in_attributes[(int) VALUE],      \
3881                  built_in_attributes[(int) CHAIN]);
3882 #include "builtin-attrs.def"
3883 #undef DEF_ATTR_NULL_TREE
3884 #undef DEF_ATTR_INT
3885 #undef DEF_ATTR_IDENT
3886 #undef DEF_ATTR_TREE_LIST
3887 }
3888
3889 /* Attribute handlers common to C front ends.  */
3890
3891 /* Handle a "packed" attribute; arguments as in
3892    struct attribute_spec.handler.  */
3893
3894 static tree
3895 handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
3896                          int flags, bool *no_add_attrs)
3897 {
3898   if (TYPE_P (*node))
3899     {
3900       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
3901         *node = build_variant_type_copy (*node);
3902       TYPE_PACKED (*node) = 1;
3903       if (TYPE_MAIN_VARIANT (*node) == *node)
3904         {
3905           /* If it is the main variant, then pack the other variants
3906              too. This happens in,
3907
3908              struct Foo {
3909                struct Foo const *ptr; // creates a variant w/o packed flag
3910                } __ attribute__((packed)); // packs it now.
3911           */
3912           tree probe;
3913
3914           for (probe = *node; probe; probe = TYPE_NEXT_VARIANT (probe))
3915             TYPE_PACKED (probe) = 1;
3916         }
3917
3918     }
3919   else if (TREE_CODE (*node) == FIELD_DECL)
3920     DECL_PACKED (*node) = 1;
3921   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
3922      used for DECL_REGISTER.  It wouldn't mean anything anyway.
3923      We can't set DECL_PACKED on the type of a TYPE_DECL, because
3924      that changes what the typedef is typing.  */
3925   else
3926     {
3927       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
3928       *no_add_attrs = true;
3929     }
3930
3931   return NULL_TREE;
3932 }
3933
3934 /* Handle a "nocommon" attribute; arguments as in
3935    struct attribute_spec.handler.  */
3936
3937 static tree
3938 handle_nocommon_attribute (tree *node, tree name,
3939                            tree ARG_UNUSED (args),
3940                            int ARG_UNUSED (flags), bool *no_add_attrs)
3941 {
3942   if (TREE_CODE (*node) == VAR_DECL)
3943     DECL_COMMON (*node) = 0;
3944   else
3945     {
3946       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
3947       *no_add_attrs = true;
3948     }
3949
3950   return NULL_TREE;
3951 }
3952
3953 /* Handle a "common" attribute; arguments as in
3954    struct attribute_spec.handler.  */
3955
3956 static tree
3957 handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args),
3958                          int ARG_UNUSED (flags), bool *no_add_attrs)
3959 {
3960   if (TREE_CODE (*node) == VAR_DECL)
3961     DECL_COMMON (*node) = 1;
3962   else
3963     {
3964       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
3965       *no_add_attrs = true;
3966     }
3967
3968   return NULL_TREE;
3969 }
3970
3971 /* Handle a "noreturn" attribute; arguments as in
3972    struct attribute_spec.handler.  */
3973
3974 static tree
3975 handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
3976                            int ARG_UNUSED (flags), bool *no_add_attrs)
3977 {
3978   tree type = TREE_TYPE (*node);
3979
3980   /* See FIXME comment in c_common_attribute_table.  */
3981   if (TREE_CODE (*node) == FUNCTION_DECL)
3982     TREE_THIS_VOLATILE (*node) = 1;
3983   else if (TREE_CODE (type) == POINTER_TYPE
3984            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
3985     TREE_TYPE (*node)
3986       = build_pointer_type
3987         (build_type_variant (TREE_TYPE (type),
3988                              TYPE_READONLY (TREE_TYPE (type)), 1));
3989   else
3990     {
3991       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
3992       *no_add_attrs = true;
3993     }
3994
3995   return NULL_TREE;
3996 }
3997
3998 /* Handle a "noinline" attribute; arguments as in
3999    struct attribute_spec.handler.  */
4000
4001 static tree
4002 handle_noinline_attribute (tree *node, tree name,
4003                            tree ARG_UNUSED (args),
4004                            int ARG_UNUSED (flags), bool *no_add_attrs)
4005 {
4006   if (TREE_CODE (*node) == FUNCTION_DECL)
4007     DECL_UNINLINABLE (*node) = 1;
4008   else
4009     {
4010       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4011       *no_add_attrs = true;
4012     }
4013
4014   return NULL_TREE;
4015 }
4016
4017 /* Handle a "always_inline" attribute; arguments as in
4018    struct attribute_spec.handler.  */
4019
4020 static tree
4021 handle_always_inline_attribute (tree *node, tree name,
4022                                 tree ARG_UNUSED (args),
4023                                 int ARG_UNUSED (flags),
4024                                 bool *no_add_attrs)
4025 {
4026   if (TREE_CODE (*node) == FUNCTION_DECL)
4027     {
4028       /* Do nothing else, just set the attribute.  We'll get at
4029          it later with lookup_attribute.  */
4030     }
4031   else
4032     {
4033       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4034       *no_add_attrs = true;
4035     }
4036
4037   return NULL_TREE;
4038 }
4039
4040 /* Handle a "used" attribute; arguments as in
4041    struct attribute_spec.handler.  */
4042
4043 static tree
4044 handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
4045                        int ARG_UNUSED (flags), bool *no_add_attrs)
4046 {
4047   tree node = *pnode;
4048
4049   if (TREE_CODE (node) == FUNCTION_DECL
4050       || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node)))
4051     {
4052       TREE_USED (node) = 1;
4053       DECL_PRESERVE_P (node) = 1;
4054     }
4055   else
4056     {
4057       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4058       *no_add_attrs = true;
4059     }
4060
4061   return NULL_TREE;
4062 }
4063
4064 /* Handle a "unused" attribute; arguments as in
4065    struct attribute_spec.handler.  */
4066
4067 static tree
4068 handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4069                          int flags, bool *no_add_attrs)
4070 {
4071   if (DECL_P (*node))
4072     {
4073       tree decl = *node;
4074
4075       if (TREE_CODE (decl) == PARM_DECL
4076           || TREE_CODE (decl) == VAR_DECL
4077           || TREE_CODE (decl) == FUNCTION_DECL
4078           || TREE_CODE (decl) == LABEL_DECL
4079           || TREE_CODE (decl) == TYPE_DECL)
4080         TREE_USED (decl) = 1;
4081       else
4082         {
4083           warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4084           *no_add_attrs = true;
4085         }
4086     }
4087   else
4088     {
4089       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4090         *node = build_variant_type_copy (*node);
4091       TREE_USED (*node) = 1;
4092     }
4093
4094   return NULL_TREE;
4095 }
4096
4097 /* Handle a "const" attribute; arguments as in
4098    struct attribute_spec.handler.  */
4099
4100 static tree
4101 handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4102                         int ARG_UNUSED (flags), bool *no_add_attrs)
4103 {
4104   tree type = TREE_TYPE (*node);
4105
4106   /* See FIXME comment on noreturn in c_common_attribute_table.  */
4107   if (TREE_CODE (*node) == FUNCTION_DECL)
4108     TREE_READONLY (*node) = 1;
4109   else if (TREE_CODE (type) == POINTER_TYPE
4110            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4111     TREE_TYPE (*node)
4112       = build_pointer_type
4113         (build_type_variant (TREE_TYPE (type), 1,
4114                              TREE_THIS_VOLATILE (TREE_TYPE (type))));
4115   else
4116     {
4117       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4118       *no_add_attrs = true;
4119     }
4120
4121   return NULL_TREE;
4122 }
4123
4124 /* Handle a "transparent_union" attribute; arguments as in
4125    struct attribute_spec.handler.  */
4126
4127 static tree
4128 handle_transparent_union_attribute (tree *node, tree name,
4129                                     tree ARG_UNUSED (args), int flags,
4130                                     bool *no_add_attrs)
4131 {
4132   tree decl = NULL_TREE;
4133   tree *type = NULL;
4134   int is_type = 0;
4135
4136   if (DECL_P (*node))
4137     {
4138       decl = *node;
4139       type = &TREE_TYPE (decl);
4140       is_type = TREE_CODE (*node) == TYPE_DECL;
4141     }
4142   else if (TYPE_P (*node))
4143     type = node, is_type = 1;
4144
4145   if (is_type
4146       && TREE_CODE (*type) == UNION_TYPE
4147       && (decl == 0
4148           || (TYPE_FIELDS (*type) != 0
4149               && TYPE_MODE (*type) == DECL_MODE (TYPE_FIELDS (*type)))))
4150     {
4151       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4152         *type = build_variant_type_copy (*type);
4153       TYPE_TRANSPARENT_UNION (*type) = 1;
4154     }
4155   else if (decl != 0 && TREE_CODE (decl) == PARM_DECL
4156            && TREE_CODE (*type) == UNION_TYPE
4157            && TYPE_MODE (*type) == DECL_MODE (TYPE_FIELDS (*type)))
4158     DECL_TRANSPARENT_UNION (decl) = 1;
4159   else
4160     {
4161       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4162       *no_add_attrs = true;
4163     }
4164
4165   return NULL_TREE;
4166 }
4167
4168 /* Handle a "constructor" attribute; arguments as in
4169    struct attribute_spec.handler.  */
4170
4171 static tree
4172 handle_constructor_attribute (tree *node, tree name,
4173                               tree ARG_UNUSED (args),
4174                               int ARG_UNUSED (flags),
4175                               bool *no_add_attrs)
4176 {
4177   tree decl = *node;
4178   tree type = TREE_TYPE (decl);
4179
4180   if (TREE_CODE (decl) == FUNCTION_DECL
4181       && TREE_CODE (type) == FUNCTION_TYPE
4182       && decl_function_context (decl) == 0)
4183     {
4184       DECL_STATIC_CONSTRUCTOR (decl) = 1;
4185       TREE_USED (decl) = 1;
4186     }
4187   else
4188     {
4189       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4190       *no_add_attrs = true;
4191     }
4192
4193   return NULL_TREE;
4194 }
4195
4196 /* Handle a "destructor" attribute; arguments as in
4197    struct attribute_spec.handler.  */
4198
4199 static tree
4200 handle_destructor_attribute (tree *node, tree name,
4201                              tree ARG_UNUSED (args),
4202                              int ARG_UNUSED (flags),
4203                              bool *no_add_attrs)
4204 {
4205   tree decl = *node;
4206   tree type = TREE_TYPE (decl);
4207
4208   if (TREE_CODE (decl) == FUNCTION_DECL
4209       && TREE_CODE (type) == FUNCTION_TYPE
4210       && decl_function_context (decl) == 0)
4211     {
4212       DECL_STATIC_DESTRUCTOR (decl) = 1;
4213       TREE_USED (decl) = 1;
4214     }
4215   else
4216     {
4217       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4218       *no_add_attrs = true;
4219     }
4220
4221   return NULL_TREE;
4222 }
4223
4224 /* Handle a "mode" attribute; arguments as in
4225    struct attribute_spec.handler.  */
4226
4227 static tree
4228 handle_mode_attribute (tree *node, tree name, tree args,
4229                        int ARG_UNUSED (flags), bool *no_add_attrs)
4230 {
4231   tree type = *node;
4232
4233   *no_add_attrs = true;
4234
4235   if (TREE_CODE (TREE_VALUE (args)) != IDENTIFIER_NODE)
4236     warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4237   else
4238     {
4239       int j;
4240       const char *p = IDENTIFIER_POINTER (TREE_VALUE (args));
4241       int len = strlen (p);
4242       enum machine_mode mode = VOIDmode;
4243       tree typefm;
4244       bool valid_mode;
4245
4246       if (len > 4 && p[0] == '_' && p[1] == '_'
4247           && p[len - 1] == '_' && p[len - 2] == '_')
4248         {
4249           char *newp = (char *) alloca (len - 1);
4250
4251           strcpy (newp, &p[2]);
4252           newp[len - 4] = '\0';
4253           p = newp;
4254         }
4255
4256       /* Change this type to have a type with the specified mode.
4257          First check for the special modes.  */
4258       if (!strcmp (p, "byte"))
4259         mode = byte_mode;
4260       else if (!strcmp (p, "word"))
4261         mode = word_mode;
4262       else if (!strcmp (p, "pointer"))
4263         mode = ptr_mode;
4264       else
4265         for (j = 0; j < NUM_MACHINE_MODES; j++)
4266           if (!strcmp (p, GET_MODE_NAME (j)))
4267             {
4268               mode = (enum machine_mode) j;
4269               break;
4270             }
4271
4272       if (mode == VOIDmode)
4273         {
4274           error ("unknown machine mode %qs", p);
4275           return NULL_TREE;
4276         }
4277
4278       valid_mode = false;
4279       switch (GET_MODE_CLASS (mode))
4280         {
4281         case MODE_INT:
4282         case MODE_PARTIAL_INT:
4283         case MODE_FLOAT:
4284           valid_mode = targetm.scalar_mode_supported_p (mode);
4285           break;
4286
4287         case MODE_COMPLEX_INT:
4288         case MODE_COMPLEX_FLOAT:
4289           valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode));
4290           break;
4291
4292         case MODE_VECTOR_INT:
4293         case MODE_VECTOR_FLOAT:
4294           warning ("specifying vector types with __attribute__ ((mode)) "
4295                    "is deprecated");
4296           warning ("use __attribute__ ((vector_size)) instead");
4297           valid_mode = vector_mode_valid_p (mode);
4298           break;
4299
4300         default:
4301           break;
4302         }
4303       if (!valid_mode)
4304         {
4305           error ("unable to emulate %qs", p);
4306           return NULL_TREE;
4307         }
4308
4309       if (POINTER_TYPE_P (type))
4310         {
4311           tree (*fn)(tree, enum machine_mode, bool);
4312
4313           if (!targetm.valid_pointer_mode (mode))
4314             {
4315               error ("invalid pointer mode %qs", p);
4316               return NULL_TREE;
4317             }
4318
4319           if (TREE_CODE (type) == POINTER_TYPE)
4320             fn = build_pointer_type_for_mode;
4321           else
4322             fn = build_reference_type_for_mode;
4323           typefm = fn (TREE_TYPE (type), mode, false);
4324         }
4325       else
4326         typefm = lang_hooks.types.type_for_mode (mode, TYPE_UNSIGNED (type));
4327
4328       if (typefm == NULL_TREE)
4329         {
4330           error ("no data type for mode %qs", p);
4331           return NULL_TREE;
4332         }
4333       else if (TREE_CODE (type) == ENUMERAL_TYPE)
4334         {
4335           /* For enumeral types, copy the precision from the integer
4336              type returned above.  If not an INTEGER_TYPE, we can't use
4337              this mode for this type.  */
4338           if (TREE_CODE (typefm) != INTEGER_TYPE)
4339             {
4340               error ("cannot use mode %qs for enumeral types", p);
4341               return NULL_TREE;
4342             }
4343
4344           if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4345             type = build_variant_type_copy (type);
4346
4347           /* We cannot use layout_type here, because that will attempt
4348              to re-layout all variants, corrupting our original.  */
4349           TYPE_PRECISION (type) = TYPE_PRECISION (typefm);
4350           TYPE_MIN_VALUE (type) = TYPE_MIN_VALUE (typefm);
4351           TYPE_MAX_VALUE (type) = TYPE_MAX_VALUE (typefm);
4352           TYPE_SIZE (type) = TYPE_SIZE (typefm);
4353           TYPE_SIZE_UNIT (type) = TYPE_SIZE_UNIT (typefm);
4354           TYPE_MODE (type) = TYPE_MODE (typefm);
4355           if (!TYPE_USER_ALIGN (type))
4356             TYPE_ALIGN (type) = TYPE_ALIGN (typefm);
4357
4358           typefm = type;
4359         }
4360       else if (VECTOR_MODE_P (mode)
4361                ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm))
4362                : TREE_CODE (type) != TREE_CODE (typefm))
4363         {
4364           error ("mode %qs applied to inappropriate type", p);
4365           return NULL_TREE;
4366         }
4367
4368       *node = typefm;
4369     }
4370
4371   return NULL_TREE;
4372 }
4373
4374 /* Handle a "section" attribute; arguments as in
4375    struct attribute_spec.handler.  */
4376
4377 static tree
4378 handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args,
4379                           int ARG_UNUSED (flags), bool *no_add_attrs)
4380 {
4381   tree decl = *node;
4382
4383   if (targetm.have_named_sections)
4384     {
4385       user_defined_section_attribute = true;
4386
4387       if ((TREE_CODE (decl) == FUNCTION_DECL
4388            || TREE_CODE (decl) == VAR_DECL)
4389           && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
4390         {
4391           if (TREE_CODE (decl) == VAR_DECL
4392               && current_function_decl != NULL_TREE
4393               && !TREE_STATIC (decl))
4394             {
4395               error ("%Jsection attribute cannot be specified for "
4396                      "local variables", decl);
4397               *no_add_attrs = true;
4398             }
4399
4400           /* The decl may have already been given a section attribute
4401              from a previous declaration.  Ensure they match.  */
4402           else if (DECL_SECTION_NAME (decl) != NULL_TREE
4403                    && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
4404                               TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
4405             {
4406               error ("%Jsection of %qD conflicts with previous declaration",
4407                      *node, *node);
4408               *no_add_attrs = true;
4409             }
4410           else
4411             DECL_SECTION_NAME (decl) = TREE_VALUE (args);
4412         }
4413       else
4414         {
4415           error ("%Jsection attribute not allowed for %qD", *node, *node);
4416           *no_add_attrs = true;
4417         }
4418     }
4419   else
4420     {
4421       error ("%Jsection attributes are not supported for this target", *node);
4422       *no_add_attrs = true;
4423     }
4424
4425   return NULL_TREE;
4426 }
4427
4428 /* Handle a "aligned" attribute; arguments as in
4429    struct attribute_spec.handler.  */
4430
4431 static tree
4432 handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args,
4433                           int flags, bool *no_add_attrs)
4434 {
4435   tree decl = NULL_TREE;
4436   tree *type = NULL;
4437   int is_type = 0;
4438   tree align_expr = (args ? TREE_VALUE (args)
4439                      : size_int (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
4440   int i;
4441
4442   if (DECL_P (*node))
4443     {
4444       decl = *node;
4445       type = &TREE_TYPE (decl);
4446       is_type = TREE_CODE (*node) == TYPE_DECL;
4447     }
4448   else if (TYPE_P (*node))
4449     type = node, is_type = 1;
4450
4451   /* Strip any NOPs of any kind.  */
4452   while (TREE_CODE (align_expr) == NOP_EXPR
4453          || TREE_CODE (align_expr) == CONVERT_EXPR
4454          || TREE_CODE (align_expr) == NON_LVALUE_EXPR)
4455     align_expr = TREE_OPERAND (align_expr, 0);
4456
4457   if (TREE_CODE (align_expr) != INTEGER_CST)
4458     {
4459       error ("requested alignment is not a constant");
4460       *no_add_attrs = true;
4461     }
4462   else if ((i = tree_log2 (align_expr)) == -1)
4463     {
4464       error ("requested alignment is not a power of 2");
4465       *no_add_attrs = true;
4466     }
4467   else if (i > HOST_BITS_PER_INT - 2)
4468     {
4469       error ("requested alignment is too large");
4470       *no_add_attrs = true;
4471     }
4472   else if (is_type)
4473     {
4474       /* If we have a TYPE_DECL, then copy the type, so that we
4475          don't accidentally modify a builtin type.  See pushdecl.  */
4476       if (decl && TREE_TYPE (decl) != error_mark_node
4477           && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
4478         {
4479           tree tt = TREE_TYPE (decl);
4480           *type = build_variant_type_copy (*type);
4481           DECL_ORIGINAL_TYPE (decl) = tt;
4482           TYPE_NAME (*type) = decl;
4483           TREE_USED (*type) = TREE_USED (decl);
4484           TREE_TYPE (decl) = *type;
4485         }
4486       else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4487         *type = build_variant_type_copy (*type);
4488
4489       TYPE_ALIGN (*type) = (1 << i) * BITS_PER_UNIT;
4490       TYPE_USER_ALIGN (*type) = 1;
4491     }
4492   else if (TREE_CODE (decl) != VAR_DECL
4493            && TREE_CODE (decl) != FIELD_DECL)
4494     {
4495       error ("%Jalignment may not be specified for %qD", decl, decl);
4496       *no_add_attrs = true;
4497     }
4498   else
4499     {
4500       DECL_ALIGN (decl) = (1 << i) * BITS_PER_UNIT;
4501       DECL_USER_ALIGN (decl) = 1;
4502     }
4503
4504   return NULL_TREE;
4505 }
4506
4507 /* Handle a "weak" attribute; arguments as in
4508    struct attribute_spec.handler.  */
4509
4510 static tree
4511 handle_weak_attribute (tree *node, tree ARG_UNUSED (name),
4512                        tree ARG_UNUSED (args),
4513                        int ARG_UNUSED (flags),
4514                        bool * ARG_UNUSED (no_add_attrs))
4515 {
4516   declare_weak (*node);
4517
4518   return NULL_TREE;
4519 }
4520
4521 /* Handle an "alias" attribute; arguments as in
4522    struct attribute_spec.handler.  */
4523
4524 static tree
4525 handle_alias_attribute (tree *node, tree name, tree args,
4526                         int ARG_UNUSED (flags), bool *no_add_attrs)
4527 {
4528   tree decl = *node;
4529
4530   if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
4531       || (TREE_CODE (decl) != FUNCTION_DECL && !DECL_EXTERNAL (decl)))
4532     {
4533       error ("%J%qD defined both normally and as an alias", decl, decl);
4534       *no_add_attrs = true;
4535     }
4536
4537   /* Note that the very first time we process a nested declaration,
4538      decl_function_context will not be set.  Indeed, *would* never
4539      be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that
4540      we do below.  After such frobbery, pushdecl would set the context.
4541      In any case, this is never what we want.  */
4542   else if (decl_function_context (decl) == 0 && current_function_decl == NULL)
4543     {
4544       tree id;
4545
4546       id = TREE_VALUE (args);
4547       if (TREE_CODE (id) != STRING_CST)
4548         {
4549           error ("alias argument not a string");
4550           *no_add_attrs = true;
4551           return NULL_TREE;
4552         }
4553       id = get_identifier (TREE_STRING_POINTER (id));
4554       /* This counts as a use of the object pointed to.  */
4555       TREE_USED (id) = 1;
4556
4557       if (TREE_CODE (decl) == FUNCTION_DECL)
4558         DECL_INITIAL (decl) = error_mark_node;
4559       else
4560         {
4561           DECL_EXTERNAL (decl) = 0;
4562           TREE_STATIC (decl) = 1;
4563         }
4564     }
4565   else
4566     {
4567       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4568       *no_add_attrs = true;
4569     }
4570
4571   return NULL_TREE;
4572 }
4573
4574 /* Handle an "visibility" attribute; arguments as in
4575    struct attribute_spec.handler.  */
4576
4577 static tree
4578 handle_visibility_attribute (tree *node, tree name, tree args,
4579                              int ARG_UNUSED (flags),
4580                              bool *no_add_attrs)
4581 {
4582   tree decl = *node;
4583   tree id = TREE_VALUE (args);
4584
4585   *no_add_attrs = true;
4586
4587   if (TYPE_P (*node))
4588     {
4589       if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE)
4590        {
4591          warning ("%qs attribute ignored on non-class types",
4592                   IDENTIFIER_POINTER (name));
4593          return NULL_TREE;
4594        }
4595     }
4596   else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl))
4597     {
4598       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4599       return NULL_TREE;
4600     }
4601
4602   if (TREE_CODE (id) != STRING_CST)
4603     {
4604       error ("visibility argument not a string");
4605       return NULL_TREE;
4606     }
4607
4608   /*  If this is a type, set the visibility on the type decl.  */
4609   if (TYPE_P (decl))
4610     {
4611       decl = TYPE_NAME (decl);
4612       if (!decl)
4613         return NULL_TREE;
4614       if (TREE_CODE (decl) == IDENTIFIER_NODE)
4615         {
4616            warning ("%qE attribute ignored on types",
4617                     name);
4618            return NULL_TREE;
4619         }
4620     }
4621
4622   if (strcmp (TREE_STRING_POINTER (id), "default") == 0)
4623     DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
4624   else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0)
4625     DECL_VISIBILITY (decl) = VISIBILITY_INTERNAL;
4626   else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0)
4627     DECL_VISIBILITY (decl) = VISIBILITY_HIDDEN;
4628   else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0)
4629     DECL_VISIBILITY (decl) = VISIBILITY_PROTECTED;
4630   else
4631     error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\"");
4632   DECL_VISIBILITY_SPECIFIED (decl) = 1;
4633
4634   /* For decls only, go ahead and attach the attribute to the node as well.
4635      This is needed so we can determine whether we have VISIBILITY_DEFAULT
4636      because the visibility was not specified, or because it was explicitly
4637      overridden from the class visibility.  */
4638   if (DECL_P (*node))
4639     *no_add_attrs = false;
4640
4641   return NULL_TREE;
4642 }
4643
4644 /* Determine the ELF symbol visibility for DECL, which is either a
4645    variable or a function.  It is an error to use this function if a
4646    definition of DECL is not available in this translation unit.
4647    Returns true if the final visibility has been determined by this
4648    function; false if the caller is free to make additional
4649    modifications.  */
4650
4651 bool
4652 c_determine_visibility (tree decl)
4653 {
4654   gcc_assert (TREE_CODE (decl) == VAR_DECL
4655               || TREE_CODE (decl) == FUNCTION_DECL);
4656
4657   /* If the user explicitly specified the visibility with an
4658      attribute, honor that.  DECL_VISIBILITY will have been set during
4659      the processing of the attribute.  We check for an explicit
4660      attribute, rather than just checking DECL_VISIBILITY_SPECIFIED,
4661      to distinguish the use of an attribute from the use of a "#pragma
4662      GCC visibility push(...)"; in the latter case we still want other
4663      considerations to be able to overrule the #pragma.  */
4664   if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl)))
4665     return true;
4666
4667   /* Anything that is exported must have default visibility.  */
4668   if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
4669       && lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))
4670     {
4671       DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
4672       DECL_VISIBILITY_SPECIFIED (decl) = 1;
4673       return true;
4674     }
4675
4676   return false;
4677 }
4678
4679 /* Handle an "tls_model" attribute; arguments as in
4680    struct attribute_spec.handler.  */
4681
4682 static tree
4683 handle_tls_model_attribute (tree *node, tree name, tree args,
4684                             int ARG_UNUSED (flags), bool *no_add_attrs)
4685 {
4686   tree decl = *node;
4687
4688   if (!DECL_THREAD_LOCAL (decl))
4689     {
4690       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4691       *no_add_attrs = true;
4692     }
4693   else
4694     {
4695       tree id;
4696
4697       id = TREE_VALUE (args);
4698       if (TREE_CODE (id) != STRING_CST)
4699         {
4700           error ("tls_model argument not a string");
4701           *no_add_attrs = true;
4702           return NULL_TREE;
4703         }
4704       if (strcmp (TREE_STRING_POINTER (id), "local-exec")
4705           && strcmp (TREE_STRING_POINTER (id), "initial-exec")
4706           && strcmp (TREE_STRING_POINTER (id), "local-dynamic")
4707           && strcmp (TREE_STRING_POINTER (id), "global-dynamic"))
4708         {
4709           error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\"");
4710           *no_add_attrs = true;
4711           return NULL_TREE;
4712         }
4713     }
4714
4715   return NULL_TREE;
4716 }
4717
4718 /* Handle a "no_instrument_function" attribute; arguments as in
4719    struct attribute_spec.handler.  */
4720
4721 static tree
4722 handle_no_instrument_function_attribute (tree *node, tree name,
4723                                          tree ARG_UNUSED (args),
4724                                          int ARG_UNUSED (flags),
4725                                          bool *no_add_attrs)
4726 {
4727   tree decl = *node;
4728
4729   if (TREE_CODE (decl) != FUNCTION_DECL)
4730     {
4731       error ("%J%qE attribute applies only to functions", decl, name);
4732       *no_add_attrs = true;
4733     }
4734   else if (DECL_INITIAL (decl))
4735     {
4736       error ("%Jcan%'t set %qE attribute after definition", decl, name);
4737       *no_add_attrs = true;
4738     }
4739   else
4740     DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
4741
4742   return NULL_TREE;
4743 }
4744
4745 /* Handle a "malloc" attribute; arguments as in
4746    struct attribute_spec.handler.  */
4747
4748 static tree
4749 handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4750                          int ARG_UNUSED (flags), bool *no_add_attrs)
4751 {
4752   if (TREE_CODE (*node) == FUNCTION_DECL)
4753     DECL_IS_MALLOC (*node) = 1;
4754   /* ??? TODO: Support types.  */
4755   else
4756     {
4757       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4758       *no_add_attrs = true;
4759     }
4760
4761   return NULL_TREE;
4762 }
4763
4764 /* Handle a "no_limit_stack" attribute; arguments as in
4765    struct attribute_spec.handler.  */
4766
4767 static tree
4768 handle_no_limit_stack_attribute (tree *node, tree name,
4769                                  tree ARG_UNUSED (args),
4770                                  int ARG_UNUSED (flags),
4771                                  bool *no_add_attrs)
4772 {
4773   tree decl = *node;
4774
4775   if (TREE_CODE (decl) != FUNCTION_DECL)
4776     {
4777       error ("%J%qE attribute applies only to functions", decl, name);
4778       *no_add_attrs = true;
4779     }
4780   else if (DECL_INITIAL (decl))
4781     {
4782       error ("%Jcan%'t set %qE attribute after definition", decl, name);
4783       *no_add_attrs = true;
4784     }
4785   else
4786     DECL_NO_LIMIT_STACK (decl) = 1;
4787
4788   return NULL_TREE;
4789 }
4790
4791 /* Handle a "pure" attribute; arguments as in
4792    struct attribute_spec.handler.  */
4793
4794 static tree
4795 handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4796                        int ARG_UNUSED (flags), bool *no_add_attrs)
4797 {
4798   if (TREE_CODE (*node) == FUNCTION_DECL)
4799     DECL_IS_PURE (*node) = 1;
4800   /* ??? TODO: Support types.  */
4801   else
4802     {
4803       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4804       *no_add_attrs = true;
4805     }
4806
4807   return NULL_TREE;
4808 }
4809
4810 /* Handle a "deprecated" attribute; arguments as in
4811    struct attribute_spec.handler.  */
4812
4813 static tree
4814 handle_deprecated_attribute (tree *node, tree name,
4815                              tree ARG_UNUSED (args), int flags,
4816                              bool *no_add_attrs)
4817 {
4818   tree type = NULL_TREE;
4819   int warn = 0;
4820   const char *what = NULL;
4821
4822   if (DECL_P (*node))
4823     {
4824       tree decl = *node;
4825       type = TREE_TYPE (decl);
4826
4827       if (TREE_CODE (decl) == TYPE_DECL
4828           || TREE_CODE (decl) == PARM_DECL
4829           || TREE_CODE (decl) == VAR_DECL
4830           || TREE_CODE (decl) == FUNCTION_DECL
4831           || TREE_CODE (decl) == FIELD_DECL)
4832         TREE_DEPRECATED (decl) = 1;
4833       else
4834         warn = 1;
4835     }
4836   else if (TYPE_P (*node))
4837     {
4838       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4839         *node = build_variant_type_copy (*node);
4840       TREE_DEPRECATED (*node) = 1;
4841       type = *node;
4842     }
4843   else
4844     warn = 1;
4845
4846   if (warn)
4847     {
4848       *no_add_attrs = true;
4849       if (type && TYPE_NAME (type))
4850         {
4851           if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
4852             what = IDENTIFIER_POINTER (TYPE_NAME (*node));
4853           else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
4854                    && DECL_NAME (TYPE_NAME (type)))
4855             what = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type)));
4856         }
4857       if (what)
4858         warning ("%qs attribute ignored for %qs",
4859                   IDENTIFIER_POINTER (name), what);
4860       else
4861         warning ("%qs attribute ignored",
4862                       IDENTIFIER_POINTER (name));
4863     }
4864
4865   return NULL_TREE;
4866 }
4867
4868 /* Handle a "vector_size" attribute; arguments as in
4869    struct attribute_spec.handler.  */
4870
4871 static tree
4872 handle_vector_size_attribute (tree *node, tree name, tree args,
4873                               int ARG_UNUSED (flags),
4874                               bool *no_add_attrs)
4875 {
4876   unsigned HOST_WIDE_INT vecsize, nunits;
4877   enum machine_mode orig_mode;
4878   tree type = *node, new_type, size;
4879
4880   *no_add_attrs = true;
4881
4882   /* Stripping NON_LVALUE_EXPR allows declarations such as
4883      typedef short v4si __attribute__((vector_size (4 * sizeof(short)))).  */
4884   size = TREE_VALUE (args);
4885   if (TREE_CODE (size) == NON_LVALUE_EXPR)
4886     size = TREE_OPERAND (size, 0);
4887
4888   if (!host_integerp (size, 1))
4889     {
4890       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
4891       return NULL_TREE;
4892     }
4893
4894   /* Get the vector size (in bytes).  */
4895   vecsize = tree_low_cst (size, 1);
4896
4897   /* We need to provide for vector pointers, vector arrays, and
4898      functions returning vectors.  For example:
4899
4900        __attribute__((vector_size(16))) short *foo;
4901
4902      In this case, the mode is SI, but the type being modified is
4903      HI, so we need to look further.  */
4904
4905   while (POINTER_TYPE_P (type)
4906          || TREE_CODE (type) == FUNCTION_TYPE
4907          || TREE_CODE (type) == METHOD_TYPE
4908          || TREE_CODE (type) == ARRAY_TYPE)
4909     type = TREE_TYPE (type);
4910
4911   /* Get the mode of the type being modified.  */
4912   orig_mode = TYPE_MODE (type);
4913
4914   if (TREE_CODE (type) == RECORD_TYPE
4915       || (GET_MODE_CLASS (orig_mode) != MODE_FLOAT
4916           && GET_MODE_CLASS (orig_mode) != MODE_INT)
4917       || !host_integerp (TYPE_SIZE_UNIT (type), 1))
4918     {
4919       error ("invalid vector type for attribute %qs",
4920              IDENTIFIER_POINTER (name));
4921       return NULL_TREE;
4922     }
4923
4924   /* Calculate how many units fit in the vector.  */
4925   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
4926   if (nunits & (nunits - 1))
4927     {
4928       error ("number of components of the vector not a power of two");
4929       return NULL_TREE;
4930     }
4931
4932   new_type = build_vector_type (type, nunits);
4933
4934   /* Build back pointers if needed.  */
4935   *node = reconstruct_complex_type (*node, new_type);
4936
4937   return NULL_TREE;
4938 }
4939
4940 /* Handle the "nonnull" attribute.  */
4941 static tree
4942 handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
4943                           tree args, int ARG_UNUSED (flags),
4944                           bool *no_add_attrs)
4945 {
4946   tree type = *node;
4947   unsigned HOST_WIDE_INT attr_arg_num;
4948
4949   /* If no arguments are specified, all pointer arguments should be
4950      non-null.  Verify a full prototype is given so that the arguments
4951      will have the correct types when we actually check them later.  */
4952   if (!args)
4953     {
4954       if (!TYPE_ARG_TYPES (type))
4955         {
4956           error ("nonnull attribute without arguments on a non-prototype");
4957           *no_add_attrs = true;
4958         }
4959       return NULL_TREE;
4960     }
4961
4962   /* Argument list specified.  Verify that each argument number references
4963      a pointer argument.  */
4964   for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
4965     {
4966       tree argument;
4967       unsigned HOST_WIDE_INT arg_num = 0, ck_num;
4968
4969       if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
4970         {
4971           error ("nonnull argument has invalid operand number (argument %lu)",
4972                  (unsigned long) attr_arg_num);
4973           *no_add_attrs = true;
4974           return NULL_TREE;
4975         }
4976
4977       argument = TYPE_ARG_TYPES (type);
4978       if (argument)
4979         {
4980           for (ck_num = 1; ; ck_num++)
4981             {
4982               if (!argument || ck_num == arg_num)
4983                 break;
4984               argument = TREE_CHAIN (argument);
4985             }
4986
4987           if (!argument
4988               || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
4989             {
4990               error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)",
4991                      (unsigned long) attr_arg_num, (unsigned long) arg_num);
4992               *no_add_attrs = true;
4993               return NULL_TREE;
4994             }
4995
4996           if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
4997             {
4998               error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)",
4999                    (unsigned long) attr_arg_num, (unsigned long) arg_num);
5000               *no_add_attrs = true;
5001               return NULL_TREE;
5002             }
5003         }
5004     }
5005
5006   return NULL_TREE;
5007 }
5008
5009 /* Check the argument list of a function call for null in argument slots
5010    that are marked as requiring a non-null pointer argument.  */
5011
5012 static void
5013 check_function_nonnull (tree attrs, tree params)
5014 {
5015   tree a, args, param;
5016   int param_num;
5017
5018   for (a = attrs; a; a = TREE_CHAIN (a))
5019     {
5020       if (is_attribute_p ("nonnull", TREE_PURPOSE (a)))
5021         {
5022           args = TREE_VALUE (a);
5023
5024           /* Walk the argument list.  If we encounter an argument number we
5025              should check for non-null, do it.  If the attribute has no args,
5026              then every pointer argument is checked (in which case the check
5027              for pointer type is done in check_nonnull_arg).  */
5028           for (param = params, param_num = 1; ;
5029                param_num++, param = TREE_CHAIN (param))
5030             {
5031               if (!param)
5032         break;
5033               if (!args || nonnull_check_p (args, param_num))
5034         check_function_arguments_recurse (check_nonnull_arg, NULL,
5035                                           TREE_VALUE (param),
5036                                           param_num);
5037             }
5038         }
5039     }
5040 }
5041
5042 /* Check that the Nth argument of a function call (counting backwards
5043    from the end) is a (pointer)0.  */
5044
5045 static void
5046 check_function_sentinel (tree attrs, tree params)
5047 {
5048   tree attr = lookup_attribute ("sentinel", attrs);
5049
5050   if (attr)
5051     {
5052       if (!params)
5053         warning ("missing sentinel in function call");
5054       else
5055         {
5056           tree sentinel, end;
5057           unsigned pos = 0;
5058
5059           if (TREE_VALUE (attr))
5060             {
5061               tree p = TREE_VALUE (TREE_VALUE (attr));
5062               STRIP_NOPS (p);
5063               pos = TREE_INT_CST_LOW (p);
5064             }
5065
5066           sentinel = end = params;
5067
5068           /* Advance `end' ahead of `sentinel' by `pos' positions.  */
5069           while (pos > 0 && TREE_CHAIN (end))
5070             {
5071               pos--;
5072               end = TREE_CHAIN (end);
5073             }
5074           if (pos > 0)
5075             {
5076               warning ("not enough arguments to fit a sentinel");
5077               return;
5078             }
5079
5080           /* Now advance both until we find the last parameter.  */
5081           while (TREE_CHAIN (end))
5082             {
5083               end = TREE_CHAIN (end);
5084               sentinel = TREE_CHAIN (sentinel);
5085             }
5086
5087           /* Validate the sentinel.  */
5088           if (!POINTER_TYPE_P (TREE_TYPE (TREE_VALUE (sentinel)))
5089               || !integer_zerop (TREE_VALUE (sentinel)))
5090             warning ("missing sentinel in function call");
5091         }
5092     }
5093 }
5094
5095 /* Helper for check_function_nonnull; given a list of operands which
5096    must be non-null in ARGS, determine if operand PARAM_NUM should be
5097    checked.  */
5098
5099 static bool
5100 nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num)
5101 {
5102   unsigned HOST_WIDE_INT arg_num = 0;
5103
5104   for (; args; args = TREE_CHAIN (args))
5105     {
5106       bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num);
5107
5108       gcc_assert (found);
5109
5110       if (arg_num == param_num)
5111         return true;
5112     }
5113   return false;
5114 }
5115
5116 /* Check that the function argument PARAM (which is operand number
5117    PARAM_NUM) is non-null.  This is called by check_function_nonnull
5118    via check_function_arguments_recurse.  */
5119
5120 static void
5121 check_nonnull_arg (void * ARG_UNUSED (ctx), tree param,
5122                    unsigned HOST_WIDE_INT param_num)
5123 {
5124   /* Just skip checking the argument if it's not a pointer.  This can
5125      happen if the "nonnull" attribute was given without an operand
5126      list (which means to check every pointer argument).  */
5127
5128   if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE)
5129     return;
5130
5131   if (integer_zerop (param))
5132     warning ("null argument where non-null required (argument %lu)",
5133              (unsigned long) param_num);
5134 }
5135
5136 /* Helper for nonnull attribute handling; fetch the operand number
5137    from the attribute argument list.  */
5138
5139 static bool
5140 get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp)
5141 {
5142   /* Strip any conversions from the arg number and verify they
5143      are constants.  */
5144   while (TREE_CODE (arg_num_expr) == NOP_EXPR
5145          || TREE_CODE (arg_num_expr) == CONVERT_EXPR
5146          || TREE_CODE (arg_num_expr) == NON_LVALUE_EXPR)
5147     arg_num_expr = TREE_OPERAND (arg_num_expr, 0);
5148
5149   if (TREE_CODE (arg_num_expr) != INTEGER_CST
5150       || TREE_INT_CST_HIGH (arg_num_expr) != 0)
5151     return false;
5152
5153   *valp = TREE_INT_CST_LOW (arg_num_expr);
5154   return true;
5155 }
5156
5157 /* Handle a "nothrow" attribute; arguments as in
5158    struct attribute_spec.handler.  */
5159
5160 static tree
5161 handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5162                           int ARG_UNUSED (flags), bool *no_add_attrs)
5163 {
5164   if (TREE_CODE (*node) == FUNCTION_DECL)
5165     TREE_NOTHROW (*node) = 1;
5166   /* ??? TODO: Support types.  */
5167   else
5168     {
5169       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
5170       *no_add_attrs = true;
5171     }
5172
5173   return NULL_TREE;
5174 }
5175
5176 /* Handle a "cleanup" attribute; arguments as in
5177    struct attribute_spec.handler.  */
5178
5179 static tree
5180 handle_cleanup_attribute (tree *node, tree name, tree args,
5181                           int ARG_UNUSED (flags), bool *no_add_attrs)
5182 {
5183   tree decl = *node;
5184   tree cleanup_id, cleanup_decl;
5185
5186   /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do
5187      for global destructors in C++.  This requires infrastructure that
5188      we don't have generically at the moment.  It's also not a feature
5189      we'd be missing too much, since we do have attribute constructor.  */
5190   if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl))
5191     {
5192       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
5193       *no_add_attrs = true;
5194       return NULL_TREE;
5195     }
5196
5197   /* Verify that the argument is a function in scope.  */
5198   /* ??? We could support pointers to functions here as well, if
5199      that was considered desirable.  */
5200   cleanup_id = TREE_VALUE (args);
5201   if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE)
5202     {
5203       error ("cleanup argument not an identifier");
5204       *no_add_attrs = true;
5205       return NULL_TREE;
5206     }
5207   cleanup_decl = lookup_name (cleanup_id);
5208   if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL)
5209     {
5210       error ("cleanup argument not a function");
5211       *no_add_attrs = true;
5212       return NULL_TREE;
5213     }
5214
5215   /* That the function has proper type is checked with the
5216      eventual call to build_function_call.  */
5217
5218   return NULL_TREE;
5219 }
5220
5221 /* Handle a "warn_unused_result" attribute.  No special handling.  */
5222
5223 static tree
5224 handle_warn_unused_result_attribute (tree *node, tree name,
5225                                tree ARG_UNUSED (args),
5226                                int ARG_UNUSED (flags), bool *no_add_attrs)
5227 {
5228   /* Ignore the attribute for functions not returning any value.  */
5229   if (VOID_TYPE_P (TREE_TYPE (*node)))
5230     {
5231       warning ("%qs attribute ignored", IDENTIFIER_POINTER (name));
5232       *no_add_attrs = true;
5233     }
5234
5235   return NULL_TREE;
5236 }
5237
5238 /* Handle a "sentinel" attribute.  */
5239
5240 static tree
5241 handle_sentinel_attribute (tree *node, tree name, tree args,
5242                            int ARG_UNUSED (flags), bool *no_add_attrs)
5243 {
5244   tree params = TYPE_ARG_TYPES (*node);
5245
5246   if (!params)
5247     {
5248       warning ("%qs attribute requires prototypes with named arguments",
5249                IDENTIFIER_POINTER (name));
5250       *no_add_attrs = true;
5251     }
5252   else
5253     {
5254       while (TREE_CHAIN (params))
5255         params = TREE_CHAIN (params);
5256
5257       if (VOID_TYPE_P (TREE_VALUE (params)))
5258         {
5259           warning ("%qs attribute only applies to variadic functions",
5260                    IDENTIFIER_POINTER (name));
5261           *no_add_attrs = true;
5262         }
5263     }
5264
5265   if (args)
5266     {
5267       tree position = TREE_VALUE (args);
5268
5269       STRIP_NOPS (position);
5270       if (TREE_CODE (position) != INTEGER_CST)
5271         {
5272           warning ("requested position is not an integer constant");
5273           *no_add_attrs = true;
5274         }
5275       else
5276         {
5277           if (tree_int_cst_lt (position, integer_zero_node))
5278             {
5279               warning ("requested position is less than zero");
5280               *no_add_attrs = true;
5281             }
5282         }
5283     }
5284
5285   return NULL_TREE;
5286 }
5287 \f
5288 /* Check for valid arguments being passed to a function.  */
5289 void
5290 check_function_arguments (tree attrs, tree params)
5291 {
5292   /* Check for null being passed in a pointer argument that must be
5293      non-null.  We also need to do this if format checking is enabled.  */
5294
5295   if (warn_nonnull)
5296     check_function_nonnull (attrs, params);
5297
5298   /* Check for errors in format strings.  */
5299
5300   if (warn_format)
5301     {
5302       check_function_format (attrs, params);
5303       check_function_sentinel (attrs, params);
5304     }
5305 }
5306
5307 /* Generic argument checking recursion routine.  PARAM is the argument to
5308    be checked.  PARAM_NUM is the number of the argument.  CALLBACK is invoked
5309    once the argument is resolved.  CTX is context for the callback.  */
5310 void
5311 check_function_arguments_recurse (void (*callback)
5312                                   (void *, tree, unsigned HOST_WIDE_INT),
5313                                   void *ctx, tree param,
5314                                   unsigned HOST_WIDE_INT param_num)
5315 {
5316   if (TREE_CODE (param) == NOP_EXPR)
5317     {
5318       /* Strip coercion.  */
5319       check_function_arguments_recurse (callback, ctx,
5320                                         TREE_OPERAND (param, 0), param_num);
5321       return;
5322     }
5323
5324   if (TREE_CODE (param) == CALL_EXPR)
5325     {
5326       tree type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (param, 0)));
5327       tree attrs;
5328       bool found_format_arg = false;
5329
5330       /* See if this is a call to a known internationalization function
5331          that modifies a format arg.  Such a function may have multiple
5332          format_arg attributes (for example, ngettext).  */
5333
5334       for (attrs = TYPE_ATTRIBUTES (type);
5335            attrs;
5336            attrs = TREE_CHAIN (attrs))
5337         if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs)))
5338           {
5339             tree inner_args;
5340             tree format_num_expr;
5341             int format_num;
5342             int i;
5343
5344             /* Extract the argument number, which was previously checked
5345                to be valid.  */
5346             format_num_expr = TREE_VALUE (TREE_VALUE (attrs));
5347             while (TREE_CODE (format_num_expr) == NOP_EXPR
5348                    || TREE_CODE (format_num_expr) == CONVERT_EXPR
5349                    || TREE_CODE (format_num_expr) == NON_LVALUE_EXPR)
5350               format_num_expr = TREE_OPERAND (format_num_expr, 0);
5351
5352             gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST
5353                         && !TREE_INT_CST_HIGH (format_num_expr));
5354
5355             format_num = TREE_INT_CST_LOW (format_num_expr);
5356
5357             for (inner_args = TREE_OPERAND (param, 1), i = 1;
5358                  inner_args != 0;
5359                  inner_args = TREE_CHAIN (inner_args), i++)
5360               if (i == format_num)
5361                 {
5362                   check_function_arguments_recurse (callback, ctx,
5363                                                     TREE_VALUE (inner_args),
5364                                                     param_num);
5365                   found_format_arg = true;
5366                   break;
5367                 }
5368           }
5369
5370       /* If we found a format_arg attribute and did a recursive check,
5371          we are done with checking this argument.  Otherwise, we continue
5372          and this will be considered a non-literal.  */
5373       if (found_format_arg)
5374         return;
5375     }
5376
5377   if (TREE_CODE (param) == COND_EXPR)
5378     {
5379       /* Check both halves of the conditional expression.  */
5380       check_function_arguments_recurse (callback, ctx,
5381                                         TREE_OPERAND (param, 1), param_num);
5382       check_function_arguments_recurse (callback, ctx,
5383                                         TREE_OPERAND (param, 2), param_num);
5384       return;
5385     }
5386
5387   (*callback) (ctx, param, param_num);
5388 }
5389
5390 /* Function to help qsort sort FIELD_DECLs by name order.  */
5391
5392 int
5393 field_decl_cmp (const void *x_p, const void *y_p)
5394 {
5395   const tree *const x = (const tree *const) x_p;
5396   const tree *const y = (const tree *const) y_p;
5397
5398   if (DECL_NAME (*x) == DECL_NAME (*y))
5399     /* A nontype is "greater" than a type.  */
5400     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
5401   if (DECL_NAME (*x) == NULL_TREE)
5402     return -1;
5403   if (DECL_NAME (*y) == NULL_TREE)
5404     return 1;
5405   if (DECL_NAME (*x) < DECL_NAME (*y))
5406     return -1;
5407   return 1;
5408 }
5409
5410 static struct {
5411   gt_pointer_operator new_value;
5412   void *cookie;
5413 } resort_data;
5414
5415 /* This routine compares two fields like field_decl_cmp but using the
5416 pointer operator in resort_data.  */
5417
5418 static int
5419 resort_field_decl_cmp (const void *x_p, const void *y_p)
5420 {
5421   const tree *const x = (const tree *const) x_p;
5422   const tree *const y = (const tree *const) y_p;
5423
5424   if (DECL_NAME (*x) == DECL_NAME (*y))
5425     /* A nontype is "greater" than a type.  */
5426     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
5427   if (DECL_NAME (*x) == NULL_TREE)
5428     return -1;
5429   if (DECL_NAME (*y) == NULL_TREE)
5430     return 1;
5431   {
5432     tree d1 = DECL_NAME (*x);
5433     tree d2 = DECL_NAME (*y);
5434     resort_data.new_value (&d1, resort_data.cookie);
5435     resort_data.new_value (&d2, resort_data.cookie);
5436     if (d1 < d2)
5437       return -1;
5438   }
5439   return 1;
5440 }
5441
5442 /* Resort DECL_SORTED_FIELDS because pointers have been reordered.  */
5443
5444 void
5445 resort_sorted_fields (void *obj,
5446                       void * ARG_UNUSED (orig_obj),
5447                       gt_pointer_operator new_value,
5448                       void *cookie)
5449 {
5450   struct sorted_fields_type *sf = (struct sorted_fields_type *) obj;
5451   resort_data.new_value = new_value;
5452   resort_data.cookie = cookie;
5453   qsort (&sf->elts[0], sf->len, sizeof (tree),
5454          resort_field_decl_cmp);
5455 }
5456
5457 /* Subroutine of c_parse_error.
5458    Return the result of concatenating LHS and RHS. RHS is really
5459    a string literal, its first character is indicated by RHS_START and
5460    RHS_SIZE is its length (including the terminating NUL character).
5461
5462    The caller is responsible for deleting the returned pointer.  */
5463
5464 static char *
5465 catenate_strings (const char *lhs, const char *rhs_start, int rhs_size)
5466 {
5467   const int lhs_size = strlen (lhs);
5468   char *result = XNEWVEC (char, lhs_size + rhs_size);
5469   strncpy (result, lhs, lhs_size);
5470   strncpy (result + lhs_size, rhs_start, rhs_size);
5471   return result;
5472 }
5473
5474 /* Issue the error given by MSGID, indicating that it occurred before
5475    TOKEN, which had the associated VALUE.  */
5476
5477 void
5478 c_parse_error (const char *msgid, enum cpp_ttype token, tree value)
5479 {
5480 #define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2))
5481
5482   char *message = NULL;
5483
5484   if (token == CPP_EOF)
5485     message = catenate_messages (msgid, " at end of input");
5486   else if (token == CPP_CHAR || token == CPP_WCHAR)
5487     {
5488       unsigned int val = TREE_INT_CST_LOW (value);
5489       const char *const ell = (token == CPP_CHAR) ? "" : "L";
5490       if (val <= UCHAR_MAX && ISGRAPH (val))
5491         message = catenate_messages (msgid, " before %s'%c'");
5492       else
5493         message = catenate_messages (msgid, " before %s'\\x%x'");
5494
5495       error (message, ell, val);
5496       free (message);
5497       message = NULL;
5498     }
5499   else if (token == CPP_STRING || token == CPP_WSTRING)
5500     message = catenate_messages (msgid, " before string constant");
5501   else if (token == CPP_NUMBER)
5502     message = catenate_messages (msgid, " before numeric constant");
5503   else if (token == CPP_NAME)
5504     {
5505       message = catenate_messages (msgid, " before %qs");
5506       error (message, IDENTIFIER_POINTER (value));
5507       free (message);
5508       message = NULL;
5509     }
5510   else if (token < N_TTYPES)
5511     {
5512       message = catenate_messages (msgid, " before %qs token");
5513       error (message, cpp_type2name (token));
5514       free (message);
5515       message = NULL;
5516     }
5517   else
5518     error (msgid);
5519
5520   if (message)
5521     {
5522       error (message);
5523       free (message);
5524     }
5525 #undef catenate_messages
5526 }
5527
5528 /* Walk a gimplified function and warn for functions whose return value is
5529    ignored and attribute((warn_unused_result)) is set.  This is done before
5530    inlining, so we don't have to worry about that.  */
5531
5532 void
5533 c_warn_unused_result (tree *top_p)
5534 {
5535   tree t = *top_p;
5536   tree_stmt_iterator i;
5537   tree fdecl, ftype;
5538
5539   switch (TREE_CODE (t))
5540     {
5541     case STATEMENT_LIST:
5542       for (i = tsi_start (*top_p); !tsi_end_p (i); tsi_next (&i))
5543         c_warn_unused_result (tsi_stmt_ptr (i));
5544       break;
5545
5546     case COND_EXPR:
5547       c_warn_unused_result (&COND_EXPR_THEN (t));
5548       c_warn_unused_result (&COND_EXPR_ELSE (t));
5549       break;
5550     case BIND_EXPR:
5551       c_warn_unused_result (&BIND_EXPR_BODY (t));
5552       break;
5553     case TRY_FINALLY_EXPR:
5554     case TRY_CATCH_EXPR:
5555       c_warn_unused_result (&TREE_OPERAND (t, 0));
5556       c_warn_unused_result (&TREE_OPERAND (t, 1));
5557       break;
5558     case CATCH_EXPR:
5559       c_warn_unused_result (&CATCH_BODY (t));
5560       break;
5561     case EH_FILTER_EXPR:
5562       c_warn_unused_result (&EH_FILTER_FAILURE (t));
5563       break;
5564
5565     case CALL_EXPR:
5566       if (TREE_USED (t))
5567         break;
5568
5569       /* This is a naked call, as opposed to a CALL_EXPR nested inside
5570          a MODIFY_EXPR.  All calls whose value is ignored should be
5571          represented like this.  Look for the attribute.  */
5572       fdecl = get_callee_fndecl (t);
5573       if (fdecl)
5574         ftype = TREE_TYPE (fdecl);
5575       else
5576         {
5577           ftype = TREE_TYPE (TREE_OPERAND (t, 0));
5578           /* Look past pointer-to-function to the function type itself.  */
5579           ftype = TREE_TYPE (ftype);
5580         }
5581
5582       if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype)))
5583         {
5584           if (fdecl)
5585             warning ("%Hignoring return value of %qD, "
5586                      "declared with attribute warn_unused_result",
5587                      EXPR_LOCUS (t), fdecl);
5588           else
5589             warning ("%Hignoring return value of function "
5590                      "declared with attribute warn_unused_result",
5591                      EXPR_LOCUS (t));
5592         }
5593       break;
5594
5595     default:
5596       /* Not a container, not a call, or a call whose value is used.  */
5597       break;
5598     }
5599 }
5600
5601 /* Build the result of __builtin_offsetof.  EXPR is a nested sequence of
5602    component references, with an INDIRECT_REF at the bottom; much like
5603    the traditional rendering of offsetof as a macro.  Returns the folded
5604    and properly cast result.  */
5605
5606 static tree
5607 fold_offsetof_1 (tree expr)
5608 {
5609   enum tree_code code = PLUS_EXPR;
5610   tree base, off, t;
5611
5612   switch (TREE_CODE (expr))
5613     {
5614     case ERROR_MARK:
5615       return expr;
5616
5617     case INDIRECT_REF:
5618       return size_zero_node;
5619
5620     case COMPONENT_REF:
5621       base = fold_offsetof_1 (TREE_OPERAND (expr, 0));
5622       if (base == error_mark_node)
5623         return base;
5624
5625       t = TREE_OPERAND (expr, 1);
5626       if (DECL_C_BIT_FIELD (t))
5627         {
5628           error ("attempt to take address of bit-field structure "
5629                  "member %qs", IDENTIFIER_POINTER (DECL_NAME (t)));
5630           return error_mark_node;
5631         }
5632       off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t),
5633                         size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t), 1)
5634                                   / BITS_PER_UNIT));
5635       break;
5636
5637     case ARRAY_REF:
5638       base = fold_offsetof_1 (TREE_OPERAND (expr, 0));
5639       if (base == error_mark_node)
5640         return base;
5641
5642       t = TREE_OPERAND (expr, 1);
5643       if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0)
5644         {
5645           code = MINUS_EXPR;
5646           t = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
5647         }
5648       t = convert (sizetype, t);
5649       off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
5650       break;
5651
5652     default:
5653       gcc_unreachable ();
5654     }
5655
5656   return size_binop (code, base, off);
5657 }
5658
5659 tree
5660 fold_offsetof (tree expr)
5661 {
5662   /* Convert back from the internal sizetype to size_t.  */
5663   return convert (size_type_node, fold_offsetof_1 (expr));
5664 }
5665
5666 /* Return nonzero if REF is an lvalue valid for this language;
5667    otherwise, print an error message and return zero.  USE says
5668    how the lvalue is being used and so selects the error message.  */
5669
5670 int
5671 lvalue_or_else (tree ref, enum lvalue_use use)
5672 {
5673   int win = lvalue_p (ref);
5674
5675   if (!win)
5676     {
5677       switch (use)
5678         {
5679         case lv_assign:
5680           error ("invalid lvalue in assignment");
5681           break;
5682         case lv_increment:
5683           error ("invalid lvalue in increment");
5684           break;
5685         case lv_decrement:
5686           error ("invalid lvalue in decrement");
5687           break;
5688         case lv_addressof:
5689           error ("invalid lvalue in unary %<&%>");
5690           break;
5691         case lv_asm:
5692           error ("invalid lvalue in asm statement");
5693           break;
5694         default:
5695           gcc_unreachable ();
5696         }
5697     }
5698
5699   return win;
5700 }
5701
5702 #include "gt-c-common.h"