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_returns_twice_attribute (tree *, tree, tree, int, bool *);
 541 static tree handle_no_limit_stack_attribute (tree *, tree, tree, int,
 542                                              bool *);
 543 static tree handle_pure_attribute (tree *, tree, tree, int, bool *);
 544 static tree handle_novops_attribute (tree *, tree, tree, int, bool *);
 545 static tree handle_deprecated_attribute (tree *, tree, tree, int,
 546                                          bool *);
 547 static tree handle_vector_size_attribute (tree *, tree, tree, int,
 548                                           bool *);
 549 static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *);
 550 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
 551 static tree handle_cleanup_attribute (tree *, tree, tree, int, bool *);
 552 static tree handle_warn_unused_result_attribute (tree *, tree, tree, int,
 553                                                  bool *);
 554 static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *);
 555
 556 static void check_function_nonnull (tree, tree);
 557 static void check_nonnull_arg (void *, tree, unsigned HOST_WIDE_INT);
 558 static bool nonnull_check_p (tree, unsigned HOST_WIDE_INT);
 559 static bool get_nonnull_operand (tree, unsigned HOST_WIDE_INT *);
 560 static int resort_field_decl_cmp (const void *, const void *);
 561
 562 /* Table of machine-independent attributes common to all C-like languages.  */
 563 const struct attribute_spec c_common_attribute_table[] =
 564 {
 565   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 566   { "packed",                 0, 0, false, false, false,
 567                               handle_packed_attribute },
 568   { "nocommon",               0, 0, true,  false, false,
 569                               handle_nocommon_attribute },
 570   { "common",                 0, 0, true,  false, false,
 571                               handle_common_attribute },
 572   /* FIXME: logically, noreturn attributes should be listed as
 573      "false, true, true" and apply to function types.  But implementing this
 574      would require all the places in the compiler that use TREE_THIS_VOLATILE
 575      on a decl to identify non-returning functions to be located and fixed
 576      to check the function type instead.  */
 577   { "noreturn",               0, 0, true,  false, false,
 578                               handle_noreturn_attribute },
 579   { "volatile",               0, 0, true,  false, false,
 580                               handle_noreturn_attribute },
 581   { "noinline",               0, 0, true,  false, false,
 582                               handle_noinline_attribute },
 583   { "always_inline",          0, 0, true,  false, false,
 584                               handle_always_inline_attribute },
 585   { "used",                   0, 0, true,  false, false,
 586                               handle_used_attribute },
 587   { "unused",                 0, 0, false, false, false,
 588                               handle_unused_attribute },
 589   /* The same comments as for noreturn attributes apply to const ones.  */
 590   { "const",                  0, 0, true,  false, false,
 591                               handle_const_attribute },
 592   { "transparent_union",      0, 0, false, false, false,
 593                               handle_transparent_union_attribute },
 594   { "constructor",            0, 0, true,  false, false,
 595                               handle_constructor_attribute },
 596   { "destructor",             0, 0, true,  false, false,
 597                               handle_destructor_attribute },
 598   { "mode",                   1, 1, false,  true, false,
 599                               handle_mode_attribute },
 600   { "section",                1, 1, true,  false, false,
 601                               handle_section_attribute },
 602   { "aligned",                0, 1, false, false, false,
 603                               handle_aligned_attribute },
 604   { "weak",                   0, 0, true,  false, false,
 605                               handle_weak_attribute },
 606   { "alias",                  1, 1, true,  false, false,
 607                               handle_alias_attribute },
 608   { "no_instrument_function", 0, 0, true,  false, false,
 609                               handle_no_instrument_function_attribute },
 610   { "malloc",                 0, 0, true,  false, false,
 611                               handle_malloc_attribute },
 612   { "returns_twice",          0, 0, true,  false, false,
 613                               handle_returns_twice_attribute },
 614   { "no_stack_limit",         0, 0, true,  false, false,
 615                               handle_no_limit_stack_attribute },
 616   { "pure",                   0, 0, true,  false, false,
 617                               handle_pure_attribute },
 618   /* For internal use (marking of builtins) only.  The name contains space
 619      to prevent its usage in source code.  */
 620   { "no vops",                0, 0, true,  false, false,
 621                               handle_novops_attribute },
 622   { "deprecated",             0, 0, false, false, false,
 623                               handle_deprecated_attribute },
 624   { "vector_size",            1, 1, false, true, false,
 625                               handle_vector_size_attribute },
 626   { "visibility",             1, 1, false, false, false,
 627                               handle_visibility_attribute },
 628   { "tls_model",              1, 1, true,  false, false,
 629                               handle_tls_model_attribute },
 630   { "nonnull",                0, -1, false, true, true,
 631                               handle_nonnull_attribute },
 632   { "nothrow",                0, 0, true,  false, false,
 633                               handle_nothrow_attribute },
 634   { "may_alias",              0, 0, false, true, false, NULL },
 635   { "cleanup",                1, 1, true, false, false,
 636                               handle_cleanup_attribute },
 637   { "warn_unused_result",     0, 0, false, true, true,
 638                               handle_warn_unused_result_attribute },
 639   { "sentinel",               0, 1, false, true, true,
 640                               handle_sentinel_attribute },
 641   { NULL,                     0, 0, false, false, false, NULL }
 642 };
 643
 644 /* Give the specifications for the format attributes, used by C and all
 645    descendants.  */
 646
 647 const struct attribute_spec c_common_format_attribute_table[] =
 648 {
 649   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 650   { "format",                 3, 3, false, true,  true,
 651                               handle_format_attribute },
 652   { "format_arg",             1, 1, false, true,  true,
 653                               handle_format_arg_attribute },
 654   { NULL,                     0, 0, false, false, false, NULL }
 655 };
 656
 657 /* Push current bindings for the function name VAR_DECLS.  */
 658
 659 void
 660 start_fname_decls (void)
 661 {
 662   unsigned ix;
 663   tree saved = NULL_TREE;
 664
 665   for (ix = 0; fname_vars[ix].decl; ix++)
 666     {
 667       tree decl = *fname_vars[ix].decl;
 668
 669       if (decl)
 670         {
 671           saved = tree_cons (decl, build_int_cst (NULL_TREE, ix), saved);
 672           *fname_vars[ix].decl = NULL_TREE;
 673         }
 674     }
 675   if (saved || saved_function_name_decls)
 676     /* Normally they'll have been NULL, so only push if we've got a
 677        stack, or they are non-NULL.  */
 678     saved_function_name_decls = tree_cons (saved, NULL_TREE,
 679                                            saved_function_name_decls);
 680 }
 681
 682 /* Finish up the current bindings, adding them into the current function's
 683    statement tree.  This must be done _before_ finish_stmt_tree is called.
 684    If there is no current function, we must be at file scope and no statements
 685    are involved. Pop the previous bindings.  */
 686
 687 void
 688 finish_fname_decls (void)
 689 {
 690   unsigned ix;
 691   tree stmts = NULL_TREE;
 692   tree stack = saved_function_name_decls;
 693
 694   for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack))
 695     append_to_statement_list (TREE_VALUE (stack), &stmts);
 696
 697   if (stmts)
 698     {
 699       tree *bodyp = &DECL_SAVED_TREE (current_function_decl);
 700
 701       if (TREE_CODE (*bodyp) == BIND_EXPR)
 702         bodyp = &BIND_EXPR_BODY (*bodyp);
 703
 704       append_to_statement_list (*bodyp, &stmts);
 705       *bodyp = stmts;
 706     }
 707
 708   for (ix = 0; fname_vars[ix].decl; ix++)
 709     *fname_vars[ix].decl = NULL_TREE;
 710
 711   if (stack)
 712     {
 713       /* We had saved values, restore them.  */
 714       tree saved;
 715
 716       for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved))
 717         {
 718           tree decl = TREE_PURPOSE (saved);
 719           unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved));
 720
 721           *fname_vars[ix].decl = decl;
 722         }
 723       stack = TREE_CHAIN (stack);
 724     }
 725   saved_function_name_decls = stack;
 726 }
 727
 728 /* Return the text name of the current function, suitably prettified
 729    by PRETTY_P.  Return string must be freed by caller.  */
 730
 731 const char *
 732 fname_as_string (int pretty_p)
 733 {
 734   const char *name = "top level";
 735   char *namep;
 736   int vrb = 2;
 737
 738   if (!pretty_p)
 739     {
 740       name = "";
 741       vrb = 0;
 742     }
 743
 744   if (current_function_decl)
 745     name = lang_hooks.decl_printable_name (current_function_decl, vrb);
 746
 747   if (c_lex_string_translate)
 748     {
 749       int len = strlen (name) + 3; /* Two for '"'s.  One for NULL.  */
 750       cpp_string cstr = { 0, 0 }, strname;
 751
 752       namep = XNEWVEC (char, len);
 753       snprintf (namep, len, "\"%s\"", name);
 754       strname.text = (unsigned char *) namep;
 755       strname.len = len - 1;
 756
 757       if (cpp_interpret_string (parse_in, &strname, 1, &cstr, false))
 758         {
 759           XDELETEVEC (namep);
 760           return (char *) cstr.text;
 761         }
 762     }
 763   else
 764     namep = xstrdup (name);
 765
 766   return namep;
 767 }
 768
 769 /* Expand DECL if it declares an entity not handled by the
 770    common code.  */
 771
 772 int
 773 c_expand_decl (tree decl)
 774 {
 775   if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl))
 776     {
 777       /* Let the back-end know about this variable.  */
 778       if (!anon_aggr_type_p (TREE_TYPE (decl)))
 779         emit_local_var (decl);
 780       else
 781         expand_anon_union_decl (decl, NULL_TREE,
 782                                 DECL_ANON_UNION_ELEMS (decl));
 783     }
 784   else
 785     return 0;
 786
 787   return 1;
 788 }
 789
 790
 791 /* Return the VAR_DECL for a const char array naming the current
 792    function. If the VAR_DECL has not yet been created, create it
 793    now. RID indicates how it should be formatted and IDENTIFIER_NODE
 794    ID is its name (unfortunately C and C++ hold the RID values of
 795    keywords in different places, so we can't derive RID from ID in
 796    this language independent code.  */
 797
 798 tree
 799 fname_decl (unsigned int rid, tree id)
 800 {
 801   unsigned ix;
 802   tree decl = NULL_TREE;
 803
 804   for (ix = 0; fname_vars[ix].decl; ix++)
 805     if (fname_vars[ix].rid == rid)
 806       break;
 807
 808   decl = *fname_vars[ix].decl;
 809   if (!decl)
 810     {
 811       /* If a tree is built here, it would normally have the lineno of
 812          the current statement.  Later this tree will be moved to the
 813          beginning of the function and this line number will be wrong.
 814          To avoid this problem set the lineno to 0 here; that prevents
 815          it from appearing in the RTL.  */
 816       tree stmts;
 817       location_t saved_location = input_location;
 818 #ifdef USE_MAPPED_LOCATION
 819       input_location = UNKNOWN_LOCATION;
 820 #else
 821       input_line = 0;
 822 #endif
 823
 824       stmts = push_stmt_list ();
 825       decl = (*make_fname_decl) (id, fname_vars[ix].pretty);
 826       stmts = pop_stmt_list (stmts);
 827       if (!IS_EMPTY_STMT (stmts))
 828         saved_function_name_decls
 829           = tree_cons (decl, stmts, saved_function_name_decls);
 830       *fname_vars[ix].decl = decl;
 831       input_location = saved_location;
 832     }
 833   if (!ix && !current_function_decl)
 834     pedwarn ("%qD is not defined outside of function scope", decl);
 835
 836   return decl;
 837 }
 838
 839 /* Given a STRING_CST, give it a suitable array-of-chars data type.  */
 840
 841 tree
 842 fix_string_type (tree value)
 843 {
 844   const int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
 845   const int wide_flag = TREE_TYPE (value) == wchar_array_type_node;
 846   const int nchars_max = flag_isoc99 ? 4095 : 509;
 847   int length = TREE_STRING_LENGTH (value);
 848   int nchars;
 849   tree e_type, i_type, a_type;
 850
 851   /* Compute the number of elements, for the array type.  */
 852   nchars = wide_flag ? length / wchar_bytes : length;
 853
 854   if (pedantic && nchars - 1 > nchars_max && !c_dialect_cxx ())
 855     pedwarn ("string length %qd is greater than the length %qd ISO C%d compilers are required to support",
 856              nchars - 1, nchars_max, flag_isoc99 ? 99 : 89);
 857
 858   e_type = wide_flag ? wchar_type_node : char_type_node;
 859   /* Create the array type for the string constant.  flag_const_strings
 860      says make the string constant an array of const char so that
 861      copying it to a non-const pointer will get a warning.  For C++,
 862      this is the standard behavior.
 863
 864      The C++ front end relies on TYPE_MAIN_VARIANT of a cv-qualified
 865      array type being the unqualified version of that type.
 866      Therefore, if we are constructing an array of const char, we must
 867      construct the matching unqualified array type first.  The C front
 868      end does not require this, but it does no harm, so we do it
 869      unconditionally.  */
 870   i_type = build_index_type (build_int_cst (NULL_TREE, nchars - 1));
 871   a_type = build_array_type (e_type, i_type);
 872   if (flag_const_strings)
 873     a_type = c_build_qualified_type (a_type, TYPE_QUAL_CONST);
 874
 875   TREE_TYPE (value) = a_type;
 876   TREE_CONSTANT (value) = 1;
 877   TREE_INVARIANT (value) = 1;
 878   TREE_READONLY (value) = 1;
 879   TREE_STATIC (value) = 1;
 880   return value;
 881 }
 882 \f
 883 /* Print a warning if a constant expression had overflow in folding.
 884    Invoke this function on every expression that the language
 885    requires to be a constant expression.
 886    Note the ANSI C standard says it is erroneous for a
 887    constant expression to overflow.  */
 888
 889 void
 890 constant_expression_warning (tree value)
 891 {
 892   if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
 893        || TREE_CODE (value) == VECTOR_CST
 894        || TREE_CODE (value) == COMPLEX_CST)
 895       && TREE_CONSTANT_OVERFLOW (value) && pedantic)
 896     pedwarn ("overflow in constant expression");
 897 }
 898
 899 /* Print a warning if an expression had overflow in folding.
 900    Invoke this function on every expression that
 901    (1) appears in the source code, and
 902    (2) might be a constant expression that overflowed, and
 903    (3) is not already checked by convert_and_check;
 904    however, do not invoke this function on operands of explicit casts.  */
 905
 906 void
 907 overflow_warning (tree value)
 908 {
 909   if ((TREE_CODE (value) == INTEGER_CST
 910        || (TREE_CODE (value) == COMPLEX_CST
 911            && TREE_CODE (TREE_REALPART (value)) == INTEGER_CST))
 912       && TREE_OVERFLOW (value))
 913     {
 914       TREE_OVERFLOW (value) = 0;
 915       if (skip_evaluation == 0)
 916         warning ("integer overflow in expression");
 917     }
 918   else if ((TREE_CODE (value) == REAL_CST
 919             || (TREE_CODE (value) == COMPLEX_CST
 920                 && TREE_CODE (TREE_REALPART (value)) == REAL_CST))
 921            && TREE_OVERFLOW (value))
 922     {
 923       TREE_OVERFLOW (value) = 0;
 924       if (skip_evaluation == 0)
 925         warning ("floating point overflow in expression");
 926     }
 927   else if (TREE_CODE (value) == VECTOR_CST && TREE_OVERFLOW (value))
 928     {
 929       TREE_OVERFLOW (value) = 0;
 930       if (skip_evaluation == 0)
 931         warning ("vector overflow in expression");
 932     }
 933 }
 934
 935 /* Print a warning if a large constant is truncated to unsigned,
 936    or if -Wconversion is used and a constant < 0 is converted to unsigned.
 937    Invoke this function on every expression that might be implicitly
 938    converted to an unsigned type.  */
 939
 940 void
 941 unsigned_conversion_warning (tree result, tree operand)
 942 {
 943   tree type = TREE_TYPE (result);
 944
 945   if (TREE_CODE (operand) == INTEGER_CST
 946       && TREE_CODE (type) == INTEGER_TYPE
 947       && TYPE_UNSIGNED (type)
 948       && skip_evaluation == 0
 949       && !int_fits_type_p (operand, type))
 950     {
 951       if (!int_fits_type_p (operand, c_common_signed_type (type)))
 952         /* This detects cases like converting -129 or 256 to unsigned char.  */
 953         warning ("large integer implicitly truncated to unsigned type");
 954       else if (warn_conversion)
 955         warning ("negative integer implicitly converted to unsigned type");
 956     }
 957 }
 958
 959 /* Nonzero if constant C has a value that is permissible
 960    for type TYPE (an INTEGER_TYPE).  */
 961
 962 static int
 963 constant_fits_type_p (tree c, tree type)
 964 {
 965   if (TREE_CODE (c) == INTEGER_CST)
 966     return int_fits_type_p (c, type);
 967
 968   c = convert (type, c);
 969   return !TREE_OVERFLOW (c);
 970 }
 971
 972 /* Nonzero if vector types T1 and T2 can be converted to each other
 973    without an explicit cast.  */
 974 int
 975 vector_types_convertible_p (tree t1, tree t2)
 976 {
 977   return targetm.vector_opaque_p (t1)
 978          || targetm.vector_opaque_p (t2)
 979          || (tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2))
 980              && INTEGRAL_TYPE_P (TREE_TYPE (t1))
 981                 == INTEGRAL_TYPE_P (TREE_TYPE (t2)));
 982 }
 983
 984 /* Convert EXPR to TYPE, warning about conversion problems with constants.
 985    Invoke this function on every expression that is converted implicitly,
 986    i.e. because of language rules and not because of an explicit cast.  */
 987
 988 tree
 989 convert_and_check (tree type, tree expr)
 990 {
 991   tree t = convert (type, expr);
 992   if (TREE_CODE (t) == INTEGER_CST)
 993     {
 994       if (TREE_OVERFLOW (t))
 995         {
 996           TREE_OVERFLOW (t) = 0;
 997
 998           /* Do not diagnose overflow in a constant expression merely
 999              because a conversion overflowed.  */
1000           TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (expr);
1001
1002           /* No warning for converting 0x80000000 to int.  */
1003           if (!(TYPE_UNSIGNED (type) < TYPE_UNSIGNED (TREE_TYPE (expr))
1004                 && TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
1005                 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (expr))))
1006             /* If EXPR fits in the unsigned version of TYPE,
1007                don't warn unless pedantic.  */
1008             if ((pedantic
1009                  || TYPE_UNSIGNED (type)
1010                  || !constant_fits_type_p (expr,
1011                                            c_common_unsigned_type (type)))
1012                 && skip_evaluation == 0)
1013               warning ("overflow in implicit constant conversion");
1014         }
1015       else
1016         unsigned_conversion_warning (t, expr);
1017     }
1018   return t;
1019 }
1020 \f
1021 /* A node in a list that describes references to variables (EXPR), which are
1022    either read accesses if WRITER is zero, or write accesses, in which case
1023    WRITER is the parent of EXPR.  */
1024 struct tlist
1025 {
1026   struct tlist *next;
1027   tree expr, writer;
1028 };
1029
1030 /* Used to implement a cache the results of a call to verify_tree.  We only
1031    use this for SAVE_EXPRs.  */
1032 struct tlist_cache
1033 {
1034   struct tlist_cache *next;
1035   struct tlist *cache_before_sp;
1036   struct tlist *cache_after_sp;
1037   tree expr;
1038 };
1039
1040 /* Obstack to use when allocating tlist structures, and corresponding
1041    firstobj.  */
1042 static struct obstack tlist_obstack;
1043 static char *tlist_firstobj = 0;
1044
1045 /* Keep track of the identifiers we've warned about, so we can avoid duplicate
1046    warnings.  */
1047 static struct tlist *warned_ids;
1048 /* SAVE_EXPRs need special treatment.  We process them only once and then
1049    cache the results.  */
1050 static struct tlist_cache *save_expr_cache;
1051
1052 static void add_tlist (struct tlist **, struct tlist *, tree, int);
1053 static void merge_tlist (struct tlist **, struct tlist *, int);
1054 static void verify_tree (tree, struct tlist **, struct tlist **, tree);
1055 static int warning_candidate_p (tree);
1056 static void warn_for_collisions (struct tlist *);
1057 static void warn_for_collisions_1 (tree, tree, struct tlist *, int);
1058 static struct tlist *new_tlist (struct tlist *, tree, tree);
1059
1060 /* Create a new struct tlist and fill in its fields.  */
1061 static struct tlist *
1062 new_tlist (struct tlist *next, tree t, tree writer)
1063 {
1064   struct tlist *l;
1065   l = XOBNEW (&tlist_obstack, struct tlist);
1066   l->next = next;
1067   l->expr = t;
1068   l->writer = writer;
1069   return l;
1070 }
1071
1072 /* Add duplicates of the nodes found in ADD to the list *TO.  If EXCLUDE_WRITER
1073    is nonnull, we ignore any node we find which has a writer equal to it.  */
1074
1075 static void
1076 add_tlist (struct tlist **to, struct tlist *add, tree exclude_writer, int copy)
1077 {
1078   while (add)
1079     {
1080       struct tlist *next = add->next;
1081       if (!copy)
1082         add->next = *to;
1083       if (!exclude_writer || add->writer != exclude_writer)
1084         *to = copy ? new_tlist (*to, add->expr, add->writer) : add;
1085       add = next;
1086     }
1087 }
1088
1089 /* Merge the nodes of ADD into TO.  This merging process is done so that for
1090    each variable that already exists in TO, no new node is added; however if
1091    there is a write access recorded in ADD, and an occurrence on TO is only
1092    a read access, then the occurrence in TO will be modified to record the
1093    write.  */
1094
1095 static void
1096 merge_tlist (struct tlist **to, struct tlist *add, int copy)
1097 {
1098   struct tlist **end = to;
1099
1100   while (*end)
1101     end = &(*end)->next;
1102
1103   while (add)
1104     {
1105       int found = 0;
1106       struct tlist *tmp2;
1107       struct tlist *next = add->next;
1108
1109       for (tmp2 = *to; tmp2; tmp2 = tmp2->next)
1110         if (tmp2->expr == add->expr)
1111           {
1112             found = 1;
1113             if (!tmp2->writer)
1114               tmp2->writer = add->writer;
1115           }
1116       if (!found)
1117         {
1118           *end = copy ? add : new_tlist (NULL, add->expr, add->writer);
1119           end = &(*end)->next;
1120           *end = 0;
1121         }
1122       add = next;
1123     }
1124 }
1125
1126 /* WRITTEN is a variable, WRITER is its parent.  Warn if any of the variable
1127    references in list LIST conflict with it, excluding reads if ONLY writers
1128    is nonzero.  */
1129
1130 static void
1131 warn_for_collisions_1 (tree written, tree writer, struct tlist *list,
1132                        int only_writes)
1133 {
1134   struct tlist *tmp;
1135
1136   /* Avoid duplicate warnings.  */
1137   for (tmp = warned_ids; tmp; tmp = tmp->next)
1138     if (tmp->expr == written)
1139       return;
1140
1141   while (list)
1142     {
1143       if (list->expr == written
1144           && list->writer != writer
1145           && (!only_writes || list->writer)
1146           && DECL_NAME (list->expr))
1147         {
1148           warned_ids = new_tlist (warned_ids, written, NULL_TREE);
1149           warning ("operation on %qE may be undefined", list->expr);
1150         }
1151       list = list->next;
1152     }
1153 }
1154
1155 /* Given a list LIST of references to variables, find whether any of these
1156    can cause conflicts due to missing sequence points.  */
1157
1158 static void
1159 warn_for_collisions (struct tlist *list)
1160 {
1161   struct tlist *tmp;
1162
1163   for (tmp = list; tmp; tmp = tmp->next)
1164     {
1165       if (tmp->writer)
1166         warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0);
1167     }
1168 }
1169
1170 /* Return nonzero if X is a tree that can be verified by the sequence point
1171    warnings.  */
1172 static int
1173 warning_candidate_p (tree x)
1174 {
1175   return TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == PARM_DECL;
1176 }
1177
1178 /* Walk the tree X, and record accesses to variables.  If X is written by the
1179    parent tree, WRITER is the parent.
1180    We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP.  If this
1181    expression or its only operand forces a sequence point, then everything up
1182    to the sequence point is stored in PBEFORE_SP.  Everything else gets stored
1183    in PNO_SP.
1184    Once we return, we will have emitted warnings if any subexpression before
1185    such a sequence point could be undefined.  On a higher level, however, the
1186    sequence point may not be relevant, and we'll merge the two lists.
1187
1188    Example: (b++, a) + b;
1189    The call that processes the COMPOUND_EXPR will store the increment of B
1190    in PBEFORE_SP, and the use of A in PNO_SP.  The higher-level call that
1191    processes the PLUS_EXPR will need to merge the two lists so that
1192    eventually, all accesses end up on the same list (and we'll warn about the
1193    unordered subexpressions b++ and b.
1194
1195    A note on merging.  If we modify the former example so that our expression
1196    becomes
1197      (b++, b) + a
1198    care must be taken not simply to add all three expressions into the final
1199    PNO_SP list.  The function merge_tlist takes care of that by merging the
1200    before-SP list of the COMPOUND_EXPR into its after-SP list in a special
1201    way, so that no more than one access to B is recorded.  */
1202
1203 static void
1204 verify_tree (tree x, struct tlist **pbefore_sp, struct tlist **pno_sp,
1205              tree writer)
1206 {
1207   struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3;
1208   enum tree_code code;
1209   enum tree_code_class cl;
1210
1211   /* X may be NULL if it is the operand of an empty statement expression
1212      ({ }).  */
1213   if (x == NULL)
1214     return;
1215
1216  restart:
1217   code = TREE_CODE (x);
1218   cl = TREE_CODE_CLASS (code);
1219
1220   if (warning_candidate_p (x))
1221     {
1222       *pno_sp = new_tlist (*pno_sp, x, writer);
1223       return;
1224     }
1225
1226   switch (code)
1227     {
1228     case CONSTRUCTOR:
1229       return;
1230
1231     case COMPOUND_EXPR:
1232     case TRUTH_ANDIF_EXPR:
1233     case TRUTH_ORIF_EXPR:
1234       tmp_before = tmp_nosp = tmp_list3 = 0;
1235       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1236       warn_for_collisions (tmp_nosp);
1237       merge_tlist (pbefore_sp, tmp_before, 0);
1238       merge_tlist (pbefore_sp, tmp_nosp, 0);
1239       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE);
1240       merge_tlist (pbefore_sp, tmp_list3, 0);
1241       return;
1242
1243     case COND_EXPR:
1244       tmp_before = tmp_list2 = 0;
1245       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE);
1246       warn_for_collisions (tmp_list2);
1247       merge_tlist (pbefore_sp, tmp_before, 0);
1248       merge_tlist (pbefore_sp, tmp_list2, 1);
1249
1250       tmp_list3 = tmp_nosp = 0;
1251       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE);
1252       warn_for_collisions (tmp_nosp);
1253       merge_tlist (pbefore_sp, tmp_list3, 0);
1254
1255       tmp_list3 = tmp_list2 = 0;
1256       verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE);
1257       warn_for_collisions (tmp_list2);
1258       merge_tlist (pbefore_sp, tmp_list3, 0);
1259       /* Rather than add both tmp_nosp and tmp_list2, we have to merge the
1260          two first, to avoid warning for (a ? b++ : b++).  */
1261       merge_tlist (&tmp_nosp, tmp_list2, 0);
1262       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1263       return;
1264
1265     case PREDECREMENT_EXPR:
1266     case PREINCREMENT_EXPR:
1267     case POSTDECREMENT_EXPR:
1268     case POSTINCREMENT_EXPR:
1269       verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x);
1270       return;
1271
1272     case MODIFY_EXPR:
1273       tmp_before = tmp_nosp = tmp_list3 = 0;
1274       verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE);
1275       verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x);
1276       /* Expressions inside the LHS are not ordered wrt. the sequence points
1277          in the RHS.  Example:
1278            *a = (a++, 2)
1279          Despite the fact that the modification of "a" is in the before_sp
1280          list (tmp_before), it conflicts with the use of "a" in the LHS.
1281          We can handle this by adding the contents of tmp_list3
1282          to those of tmp_before, and redoing the collision warnings for that
1283          list.  */
1284       add_tlist (&tmp_before, tmp_list3, x, 1);
1285       warn_for_collisions (tmp_before);
1286       /* Exclude the LHS itself here; we first have to merge it into the
1287          tmp_nosp list.  This is done to avoid warning for "a = a"; if we
1288          didn't exclude the LHS, we'd get it twice, once as a read and once
1289          as a write.  */
1290       add_tlist (pno_sp, tmp_list3, x, 0);
1291       warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1);
1292
1293       merge_tlist (pbefore_sp, tmp_before, 0);
1294       if (warning_candidate_p (TREE_OPERAND (x, 0)))
1295         merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0);
1296       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1);
1297       return;
1298
1299     case CALL_EXPR:
1300       /* We need to warn about conflicts among arguments and conflicts between
1301          args and the function address.  Side effects of the function address,
1302          however, are not ordered by the sequence point of the call.  */
1303       tmp_before = tmp_nosp = tmp_list2 = tmp_list3 = 0;
1304       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1305       if (TREE_OPERAND (x, 1))
1306         verify_tree (TREE_OPERAND (x, 1), &tmp_list2, &tmp_list3, NULL_TREE);
1307       merge_tlist (&tmp_list3, tmp_list2, 0);
1308       add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0);
1309       add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0);
1310       warn_for_collisions (tmp_before);
1311       add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0);
1312       return;
1313
1314     case TREE_LIST:
1315       /* Scan all the list, e.g. indices of multi dimensional array.  */
1316       while (x)
1317         {
1318           tmp_before = tmp_nosp = 0;
1319           verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE);
1320           merge_tlist (&tmp_nosp, tmp_before, 0);
1321           add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1322           x = TREE_CHAIN (x);
1323         }
1324       return;
1325
1326     case SAVE_EXPR:
1327       {
1328         struct tlist_cache *t;
1329         for (t = save_expr_cache; t; t = t->next)
1330           if (t->expr == x)
1331             break;
1332
1333         if (!t)
1334           {
1335             t = XOBNEW (&tlist_obstack, struct tlist_cache);
1336             t->next = save_expr_cache;
1337             t->expr = x;
1338             save_expr_cache = t;
1339
1340             tmp_before = tmp_nosp = 0;
1341             verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1342             warn_for_collisions (tmp_nosp);
1343
1344             tmp_list3 = 0;
1345             while (tmp_nosp)
1346               {
1347                 struct tlist *t = tmp_nosp;
1348                 tmp_nosp = t->next;
1349                 merge_tlist (&tmp_list3, t, 0);
1350               }
1351             t->cache_before_sp = tmp_before;
1352             t->cache_after_sp = tmp_list3;
1353           }
1354         merge_tlist (pbefore_sp, t->cache_before_sp, 1);
1355         add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1);
1356         return;
1357       }
1358
1359     default:
1360       /* For other expressions, simply recurse on their operands.
1361          Manual tail recursion for unary expressions.
1362          Other non-expressions need not be processed.  */
1363       if (cl == tcc_unary)
1364         {
1365           x = TREE_OPERAND (x, 0);
1366           writer = 0;
1367           goto restart;
1368         }
1369       else if (IS_EXPR_CODE_CLASS (cl))
1370         {
1371           int lp;
1372           int max = TREE_CODE_LENGTH (TREE_CODE (x));
1373           for (lp = 0; lp < max; lp++)
1374             {
1375               tmp_before = tmp_nosp = 0;
1376               verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, 0);
1377               merge_tlist (&tmp_nosp, tmp_before, 0);
1378               add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1379             }
1380         }
1381       return;
1382     }
1383 }
1384
1385 /* Try to warn for undefined behavior in EXPR due to missing sequence
1386    points.  */
1387
1388 void
1389 verify_sequence_points (tree expr)
1390 {
1391   struct tlist *before_sp = 0, *after_sp = 0;
1392
1393   warned_ids = 0;
1394   save_expr_cache = 0;
1395   if (tlist_firstobj == 0)
1396     {
1397       gcc_obstack_init (&tlist_obstack);
1398       tlist_firstobj = (char *) obstack_alloc (&tlist_obstack, 0);
1399     }
1400
1401   verify_tree (expr, &before_sp, &after_sp, 0);
1402   warn_for_collisions (after_sp);
1403   obstack_free (&tlist_obstack, tlist_firstobj);
1404 }
1405 \f
1406 /* Validate the expression after `case' and apply default promotions.  */
1407
1408 static tree
1409 check_case_value (tree value)
1410 {
1411   if (value == NULL_TREE)
1412     return value;
1413
1414   /* ??? Can we ever get nops here for a valid case value?  We
1415      shouldn't for C.  */
1416   STRIP_TYPE_NOPS (value);
1417   /* In C++, the following is allowed:
1418
1419        const int i = 3;
1420        switch (...) { case i: ... }
1421
1422      So, we try to reduce the VALUE to a constant that way.  */
1423   if (c_dialect_cxx ())
1424     {
1425       value = decl_constant_value (value);
1426       STRIP_TYPE_NOPS (value);
1427       value = fold (value);
1428     }
1429
1430   if (TREE_CODE (value) == INTEGER_CST)
1431     /* Promote char or short to int.  */
1432     value = perform_integral_promotions (value);
1433   else if (value != error_mark_node)
1434     {
1435       error ("case label does not reduce to an integer constant");
1436       value = error_mark_node;
1437     }
1438
1439   constant_expression_warning (value);
1440
1441   return value;
1442 }
1443 \f
1444 /* See if the case values LOW and HIGH are in the range of the original
1445    type (i.e. before the default conversion to int) of the switch testing
1446    expression.
1447    TYPE is the promoted type of the testing expression, and ORIG_TYPE is
1448    the type before promoting it.  CASE_LOW_P is a pointer to the lower
1449    bound of the case label, and CASE_HIGH_P is the upper bound or NULL
1450    if the case is not a case range.
1451    The caller has to make sure that we are not called with NULL for
1452    CASE_LOW_P (i.e. the default case).
1453    Returns true if the case label is in range of ORIG_TYPE (satured or
1454    untouched) or false if the label is out of range.  */
1455
1456 static bool
1457 check_case_bounds (tree type, tree orig_type,
1458                    tree *case_low_p, tree *case_high_p)
1459 {
1460   tree min_value, max_value;
1461   tree case_low = *case_low_p;
1462   tree case_high = case_high_p ? *case_high_p : case_low;
1463
1464   /* If there was a problem with the original type, do nothing.  */
1465   if (orig_type == error_mark_node)
1466     return true;
1467
1468   min_value = TYPE_MIN_VALUE (orig_type);
1469   max_value = TYPE_MAX_VALUE (orig_type);
1470
1471   /* Case label is less than minimum for type.  */
1472   if (tree_int_cst_compare (case_low, min_value) < 0
1473       && tree_int_cst_compare (case_high, min_value) < 0)
1474     {
1475       warning ("case label value is less than minimum value for type");
1476       return false;
1477     }
1478
1479   /* Case value is greater than maximum for type.  */
1480   if (tree_int_cst_compare (case_low, max_value) > 0
1481       && tree_int_cst_compare (case_high, max_value) > 0)
1482     {
1483       warning ("case label value exceeds maximum value for type");
1484       return false;
1485     }
1486
1487   /* Saturate lower case label value to minimum.  */
1488   if (tree_int_cst_compare (case_high, min_value) >= 0
1489       && tree_int_cst_compare (case_low, min_value) < 0)
1490     {
1491       warning ("lower value in case label range"
1492                " less than minimum value for type");
1493       case_low = min_value;
1494     }
1495
1496   /* Saturate upper case label value to maximum.  */
1497   if (tree_int_cst_compare (case_low, max_value) <= 0
1498       && tree_int_cst_compare (case_high, max_value) > 0)
1499     {
1500       warning ("upper value in case label range"
1501                " exceeds maximum value for type");
1502       case_high = max_value;
1503     }
1504
1505   if (*case_low_p != case_low)
1506     *case_low_p = convert (type, case_low);
1507   if (case_high_p && *case_high_p != case_high)
1508     *case_high_p = convert (type, case_high);
1509
1510   return true;
1511 }
1512 \f
1513 /* Return an integer type with BITS bits of precision,
1514    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
1515
1516 tree
1517 c_common_type_for_size (unsigned int bits, int unsignedp)
1518 {
1519   if (bits == TYPE_PRECISION (integer_type_node))
1520     return unsignedp ? unsigned_type_node : integer_type_node;
1521
1522   if (bits == TYPE_PRECISION (signed_char_type_node))
1523     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1524
1525   if (bits == TYPE_PRECISION (short_integer_type_node))
1526     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1527
1528   if (bits == TYPE_PRECISION (long_integer_type_node))
1529     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1530
1531   if (bits == TYPE_PRECISION (long_long_integer_type_node))
1532     return (unsignedp ? long_long_unsigned_type_node
1533             : long_long_integer_type_node);
1534
1535   if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
1536     return (unsignedp ? widest_unsigned_literal_type_node
1537             : widest_integer_literal_type_node);
1538
1539   if (bits <= TYPE_PRECISION (intQI_type_node))
1540     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1541
1542   if (bits <= TYPE_PRECISION (intHI_type_node))
1543     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1544
1545   if (bits <= TYPE_PRECISION (intSI_type_node))
1546     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1547
1548   if (bits <= TYPE_PRECISION (intDI_type_node))
1549     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1550
1551   return 0;
1552 }
1553
1554 /* Used for communication between c_common_type_for_mode and
1555    c_register_builtin_type.  */
1556 static GTY(()) tree registered_builtin_types;
1557
1558 /* Return a data type that has machine mode MODE.
1559    If the mode is an integer,
1560    then UNSIGNEDP selects between signed and unsigned types.  */
1561
1562 tree
1563 c_common_type_for_mode (enum machine_mode mode, int unsignedp)
1564 {
1565   tree t;
1566
1567   if (mode == TYPE_MODE (integer_type_node))
1568     return unsignedp ? unsigned_type_node : integer_type_node;
1569
1570   if (mode == TYPE_MODE (signed_char_type_node))
1571     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1572
1573   if (mode == TYPE_MODE (short_integer_type_node))
1574     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1575
1576   if (mode == TYPE_MODE (long_integer_type_node))
1577     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1578
1579   if (mode == TYPE_MODE (long_long_integer_type_node))
1580     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
1581
1582   if (mode == TYPE_MODE (widest_integer_literal_type_node))
1583     return unsignedp ? widest_unsigned_literal_type_node
1584                      : widest_integer_literal_type_node;
1585
1586   if (mode == QImode)
1587     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1588
1589   if (mode == HImode)
1590     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1591
1592   if (mode == SImode)
1593     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1594
1595   if (mode == DImode)
1596     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1597
1598 #if HOST_BITS_PER_WIDE_INT >= 64
1599   if (mode == TYPE_MODE (intTI_type_node))
1600     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
1601 #endif
1602
1603   if (mode == TYPE_MODE (float_type_node))
1604     return float_type_node;
1605
1606   if (mode == TYPE_MODE (double_type_node))
1607     return double_type_node;
1608
1609   if (mode == TYPE_MODE (long_double_type_node))
1610     return long_double_type_node;
1611
1612   if (mode == TYPE_MODE (void_type_node))
1613     return void_type_node;
1614
1615   if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
1616     return (unsignedp
1617             ? make_unsigned_type (GET_MODE_PRECISION (mode))
1618             : make_signed_type (GET_MODE_PRECISION (mode)));
1619
1620   if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
1621     return (unsignedp
1622             ? make_unsigned_type (GET_MODE_PRECISION (mode))
1623             : make_signed_type (GET_MODE_PRECISION (mode)));
1624
1625   if (COMPLEX_MODE_P (mode))
1626     {
1627       enum machine_mode inner_mode;
1628       tree inner_type;
1629
1630       if (mode == TYPE_MODE (complex_float_type_node))
1631         return complex_float_type_node;
1632       if (mode == TYPE_MODE (complex_double_type_node))
1633         return complex_double_type_node;
1634       if (mode == TYPE_MODE (complex_long_double_type_node))
1635         return complex_long_double_type_node;
1636
1637       if (mode == TYPE_MODE (complex_integer_type_node) && !unsignedp)
1638         return complex_integer_type_node;
1639
1640       inner_mode = GET_MODE_INNER (mode);
1641       inner_type = c_common_type_for_mode (inner_mode, unsignedp);
1642       if (inner_type != NULL_TREE)
1643         return build_complex_type (inner_type);
1644     }
1645   else if (VECTOR_MODE_P (mode))
1646     {
1647       enum machine_mode inner_mode = GET_MODE_INNER (mode);
1648       tree inner_type = c_common_type_for_mode (inner_mode, unsignedp);
1649       if (inner_type != NULL_TREE)
1650         return build_vector_type_for_mode (inner_type, mode);
1651     }
1652
1653   for (t = registered_builtin_types; t; t = TREE_CHAIN (t))
1654     if (TYPE_MODE (TREE_VALUE (t)) == mode)
1655       return TREE_VALUE (t);
1656
1657   return 0;
1658 }
1659
1660 /* Return an unsigned type the same as TYPE in other respects.  */
1661 tree
1662 c_common_unsigned_type (tree type)
1663 {
1664   tree type1 = TYPE_MAIN_VARIANT (type);
1665   if (type1 == signed_char_type_node || type1 == char_type_node)
1666     return unsigned_char_type_node;
1667   if (type1 == integer_type_node)
1668     return unsigned_type_node;
1669   if (type1 == short_integer_type_node)
1670     return short_unsigned_type_node;
1671   if (type1 == long_integer_type_node)
1672     return long_unsigned_type_node;
1673   if (type1 == long_long_integer_type_node)
1674     return long_long_unsigned_type_node;
1675   if (type1 == widest_integer_literal_type_node)
1676     return widest_unsigned_literal_type_node;
1677 #if HOST_BITS_PER_WIDE_INT >= 64
1678   if (type1 == intTI_type_node)
1679     return unsigned_intTI_type_node;
1680 #endif
1681   if (type1 == intDI_type_node)
1682     return unsigned_intDI_type_node;
1683   if (type1 == intSI_type_node)
1684     return unsigned_intSI_type_node;
1685   if (type1 == intHI_type_node)
1686     return unsigned_intHI_type_node;
1687   if (type1 == intQI_type_node)
1688     return unsigned_intQI_type_node;
1689
1690   return c_common_signed_or_unsigned_type (1, type);
1691 }
1692
1693 /* Return a signed type the same as TYPE in other respects.  */
1694
1695 tree
1696 c_common_signed_type (tree type)
1697 {
1698   tree type1 = TYPE_MAIN_VARIANT (type);
1699   if (type1 == unsigned_char_type_node || type1 == char_type_node)
1700     return signed_char_type_node;
1701   if (type1 == unsigned_type_node)
1702     return integer_type_node;
1703   if (type1 == short_unsigned_type_node)
1704     return short_integer_type_node;
1705   if (type1 == long_unsigned_type_node)
1706     return long_integer_type_node;
1707   if (type1 == long_long_unsigned_type_node)
1708     return long_long_integer_type_node;
1709   if (type1 == widest_unsigned_literal_type_node)
1710     return widest_integer_literal_type_node;
1711 #if HOST_BITS_PER_WIDE_INT >= 64
1712   if (type1 == unsigned_intTI_type_node)
1713     return intTI_type_node;
1714 #endif
1715   if (type1 == unsigned_intDI_type_node)
1716     return intDI_type_node;
1717   if (type1 == unsigned_intSI_type_node)
1718     return intSI_type_node;
1719   if (type1 == unsigned_intHI_type_node)
1720     return intHI_type_node;
1721   if (type1 == unsigned_intQI_type_node)
1722     return intQI_type_node;
1723
1724   return c_common_signed_or_unsigned_type (0, type);
1725 }
1726
1727 /* Return a type the same as TYPE except unsigned or
1728    signed according to UNSIGNEDP.  */
1729
1730 tree
1731 c_common_signed_or_unsigned_type (int unsignedp, tree type)
1732 {
1733   if (!INTEGRAL_TYPE_P (type)
1734       || TYPE_UNSIGNED (type) == unsignedp)
1735     return type;
1736
1737   /* For ENUMERAL_TYPEs in C++, must check the mode of the types, not
1738      the precision; they have precision set to match their range, but
1739      may use a wider mode to match an ABI.  If we change modes, we may
1740      wind up with bad conversions.  For INTEGER_TYPEs in C, must check
1741      the precision as well, so as to yield correct results for
1742      bit-field types.  C++ does not have these separate bit-field
1743      types, and producing a signed or unsigned variant of an
1744      ENUMERAL_TYPE may cause other problems as well.  */
1745
1746 #define TYPE_OK(node)                                                       \
1747   (TYPE_MODE (type) == TYPE_MODE (node)                                     \
1748    && (c_dialect_cxx () || TYPE_PRECISION (type) == TYPE_PRECISION (node)))
1749   if (TYPE_OK (signed_char_type_node))
1750     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1751   if (TYPE_OK (integer_type_node))
1752     return unsignedp ? unsigned_type_node : integer_type_node;
1753   if (TYPE_OK (short_integer_type_node))
1754     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1755   if (TYPE_OK (long_integer_type_node))
1756     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1757   if (TYPE_OK (long_long_integer_type_node))
1758     return (unsignedp ? long_long_unsigned_type_node
1759             : long_long_integer_type_node);
1760   if (TYPE_OK (widest_integer_literal_type_node))
1761     return (unsignedp ? widest_unsigned_literal_type_node
1762             : widest_integer_literal_type_node);
1763
1764 #if HOST_BITS_PER_WIDE_INT >= 64
1765   if (TYPE_OK (intTI_type_node))
1766     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
1767 #endif
1768   if (TYPE_OK (intDI_type_node))
1769     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1770   if (TYPE_OK (intSI_type_node))
1771     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1772   if (TYPE_OK (intHI_type_node))
1773     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1774   if (TYPE_OK (intQI_type_node))
1775     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1776 #undef TYPE_OK
1777
1778   if (c_dialect_cxx ())
1779     return type;
1780   else
1781     return build_nonstandard_integer_type (TYPE_PRECISION (type), unsignedp);
1782 }
1783
1784 /* The C version of the register_builtin_type langhook.  */
1785
1786 void
1787 c_register_builtin_type (tree type, const char* name)
1788 {
1789   tree decl;
1790
1791   decl = build_decl (TYPE_DECL, get_identifier (name), type);
1792   DECL_ARTIFICIAL (decl) = 1;
1793   if (!TYPE_NAME (type))
1794     TYPE_NAME (type) = decl;
1795   pushdecl (decl);
1796
1797   registered_builtin_types = tree_cons (0, type, registered_builtin_types);
1798 }
1799
1800 \f
1801 /* Return the minimum number of bits needed to represent VALUE in a
1802    signed or unsigned type, UNSIGNEDP says which.  */
1803
1804 unsigned int
1805 min_precision (tree value, int unsignedp)
1806 {
1807   int log;
1808
1809   /* If the value is negative, compute its negative minus 1.  The latter
1810      adjustment is because the absolute value of the largest negative value
1811      is one larger than the largest positive value.  This is equivalent to
1812      a bit-wise negation, so use that operation instead.  */
1813
1814   if (tree_int_cst_sgn (value) < 0)
1815     value = fold (build1 (BIT_NOT_EXPR, TREE_TYPE (value), value));
1816
1817   /* Return the number of bits needed, taking into account the fact
1818      that we need one more bit for a signed than unsigned type.  */
1819
1820   if (integer_zerop (value))
1821     log = 0;
1822   else
1823     log = tree_floor_log2 (value);
1824
1825   return log + 1 + !unsignedp;
1826 }
1827 \f
1828 /* Print an error message for invalid operands to arith operation
1829    CODE.  NOP_EXPR is used as a special case (see
1830    c_common_truthvalue_conversion).  */
1831
1832 void
1833 binary_op_error (enum tree_code code)
1834 {
1835   const char *opname;
1836
1837   switch (code)
1838     {
1839     case NOP_EXPR:
1840       error ("invalid truth-value expression");
1841       return;
1842
1843     case PLUS_EXPR:
1844       opname = "+"; break;
1845     case MINUS_EXPR:
1846       opname = "-"; break;
1847     case MULT_EXPR:
1848       opname = "*"; break;
1849     case MAX_EXPR:
1850       opname = "max"; break;
1851     case MIN_EXPR:
1852       opname = "min"; break;
1853     case EQ_EXPR:
1854       opname = "=="; break;
1855     case NE_EXPR:
1856       opname = "!="; break;
1857     case LE_EXPR:
1858       opname = "<="; break;
1859     case GE_EXPR:
1860       opname = ">="; break;
1861     case LT_EXPR:
1862       opname = "<"; break;
1863     case GT_EXPR:
1864       opname = ">"; break;
1865     case LSHIFT_EXPR:
1866       opname = "<<"; break;
1867     case RSHIFT_EXPR:
1868       opname = ">>"; break;
1869     case TRUNC_MOD_EXPR:
1870     case FLOOR_MOD_EXPR:
1871       opname = "%"; break;
1872     case TRUNC_DIV_EXPR:
1873     case FLOOR_DIV_EXPR:
1874       opname = "/"; break;
1875     case BIT_AND_EXPR:
1876       opname = "&"; break;
1877     case BIT_IOR_EXPR:
1878       opname = "|"; break;
1879     case TRUTH_ANDIF_EXPR:
1880       opname = "&&"; break;
1881     case TRUTH_ORIF_EXPR:
1882       opname = "||"; break;
1883     case BIT_XOR_EXPR:
1884       opname = "^"; break;
1885     default:
1886       gcc_unreachable ();
1887     }
1888   error ("invalid operands to binary %s", opname);
1889 }
1890 \f
1891 /* Subroutine of build_binary_op, used for comparison operations.
1892    See if the operands have both been converted from subword integer types
1893    and, if so, perhaps change them both back to their original type.
1894    This function is also responsible for converting the two operands
1895    to the proper common type for comparison.
1896
1897    The arguments of this function are all pointers to local variables
1898    of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
1899    RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.
1900
1901    If this function returns nonzero, it means that the comparison has
1902    a constant value.  What this function returns is an expression for
1903    that value.  */
1904
1905 tree
1906 shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr,
1907                  enum tree_code *rescode_ptr)
1908 {
1909   tree type;
1910   tree op0 = *op0_ptr;
1911   tree op1 = *op1_ptr;
1912   int unsignedp0, unsignedp1;
1913   int real1, real2;
1914   tree primop0, primop1;
1915   enum tree_code code = *rescode_ptr;
1916
1917   /* Throw away any conversions to wider types
1918      already present in the operands.  */
1919
1920   primop0 = get_narrower (op0, &unsignedp0);
1921   primop1 = get_narrower (op1, &unsignedp1);
1922
1923   /* Handle the case that OP0 does not *contain* a conversion
1924      but it *requires* conversion to FINAL_TYPE.  */
1925
1926   if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
1927     unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0));
1928   if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
1929     unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1));
1930
1931   /* If one of the operands must be floated, we cannot optimize.  */
1932   real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
1933   real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
1934
1935   /* If first arg is constant, swap the args (changing operation
1936      so value is preserved), for canonicalization.  Don't do this if
1937      the second arg is 0.  */
1938
1939   if (TREE_CONSTANT (primop0)
1940       && !integer_zerop (primop1) && !real_zerop (primop1))
1941     {
1942       tree tem = primop0;
1943       int temi = unsignedp0;
1944       primop0 = primop1;
1945       primop1 = tem;
1946       tem = op0;
1947       op0 = op1;
1948       op1 = tem;
1949       *op0_ptr = op0;
1950       *op1_ptr = op1;
1951       unsignedp0 = unsignedp1;
1952       unsignedp1 = temi;
1953       temi = real1;
1954       real1 = real2;
1955       real2 = temi;
1956
1957       switch (code)
1958         {
1959         case LT_EXPR:
1960           code = GT_EXPR;
1961           break;
1962         case GT_EXPR:
1963           code = LT_EXPR;
1964           break;
1965         case LE_EXPR:
1966           code = GE_EXPR;
1967           break;
1968         case GE_EXPR:
1969           code = LE_EXPR;
1970           break;
1971         default:
1972           break;
1973         }
1974       *rescode_ptr = code;
1975     }
1976
1977   /* If comparing an integer against a constant more bits wide,
1978      maybe we can deduce a value of 1 or 0 independent of the data.
1979      Or else truncate the constant now
1980      rather than extend the variable at run time.
1981
1982      This is only interesting if the constant is the wider arg.
1983      Also, it is not safe if the constant is unsigned and the
1984      variable arg is signed, since in this case the variable
1985      would be sign-extended and then regarded as unsigned.
1986      Our technique fails in this case because the lowest/highest
1987      possible unsigned results don't follow naturally from the
1988      lowest/highest possible values of the variable operand.
1989      For just EQ_EXPR and NE_EXPR there is another technique that
1990      could be used: see if the constant can be faithfully represented
1991      in the other operand's type, by truncating it and reextending it
1992      and see if that preserves the constant's value.  */
1993
1994   if (!real1 && !real2
1995       && TREE_CODE (primop1) == INTEGER_CST
1996       && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
1997     {
1998       int min_gt, max_gt, min_lt, max_lt;
1999       tree maxval, minval;
2000       /* 1 if comparison is nominally unsigned.  */
2001       int unsignedp = TYPE_UNSIGNED (*restype_ptr);
2002       tree val;
2003
2004       type = c_common_signed_or_unsigned_type (unsignedp0,
2005                                                TREE_TYPE (primop0));
2006
2007       maxval = TYPE_MAX_VALUE (type);
2008       minval = TYPE_MIN_VALUE (type);
2009
2010       if (unsignedp && !unsignedp0)
2011         *restype_ptr = c_common_signed_type (*restype_ptr);
2012
2013       if (TREE_TYPE (primop1) != *restype_ptr)
2014         {
2015           /* Convert primop1 to target type, but do not introduce
2016              additional overflow.  We know primop1 is an int_cst.  */
2017           tree tmp = build_int_cst_wide (*restype_ptr,
2018                                          TREE_INT_CST_LOW (primop1),
2019                                          TREE_INT_CST_HIGH (primop1));
2020
2021           primop1 = force_fit_type (tmp, 0, TREE_OVERFLOW (primop1),
2022                                     TREE_CONSTANT_OVERFLOW (primop1));
2023         }
2024       if (type != *restype_ptr)
2025         {
2026           minval = convert (*restype_ptr, minval);
2027           maxval = convert (*restype_ptr, maxval);
2028         }
2029
2030       if (unsignedp && unsignedp0)
2031         {
2032           min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
2033           max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
2034           min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
2035           max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
2036         }
2037       else
2038         {
2039           min_gt = INT_CST_LT (primop1, minval);
2040           max_gt = INT_CST_LT (primop1, maxval);
2041           min_lt = INT_CST_LT (minval, primop1);
2042           max_lt = INT_CST_LT (maxval, primop1);
2043         }
2044
2045       val = 0;
2046       /* This used to be a switch, but Genix compiler can't handle that.  */
2047       if (code == NE_EXPR)
2048         {
2049           if (max_lt || min_gt)
2050             val = truthvalue_true_node;
2051         }
2052       else if (code == EQ_EXPR)
2053         {
2054           if (max_lt || min_gt)
2055             val = truthvalue_false_node;
2056         }
2057       else if (code == LT_EXPR)
2058         {
2059           if (max_lt)
2060             val = truthvalue_true_node;
2061           if (!min_lt)
2062             val = truthvalue_false_node;
2063         }
2064       else if (code == GT_EXPR)
2065         {
2066           if (min_gt)
2067             val = truthvalue_true_node;
2068           if (!max_gt)
2069             val = truthvalue_false_node;
2070         }
2071       else if (code == LE_EXPR)
2072         {
2073           if (!max_gt)
2074             val = truthvalue_true_node;
2075           if (min_gt)
2076             val = truthvalue_false_node;
2077         }
2078       else if (code == GE_EXPR)
2079         {
2080           if (!min_lt)
2081             val = truthvalue_true_node;
2082           if (max_lt)
2083             val = truthvalue_false_node;
2084         }
2085
2086       /* If primop0 was sign-extended and unsigned comparison specd,
2087          we did a signed comparison above using the signed type bounds.
2088          But the comparison we output must be unsigned.
2089
2090          Also, for inequalities, VAL is no good; but if the signed
2091          comparison had *any* fixed result, it follows that the
2092          unsigned comparison just tests the sign in reverse
2093          (positive values are LE, negative ones GE).
2094          So we can generate an unsigned comparison
2095          against an extreme value of the signed type.  */
2096
2097       if (unsignedp && !unsignedp0)
2098         {
2099           if (val != 0)
2100             switch (code)
2101               {
2102               case LT_EXPR:
2103               case GE_EXPR:
2104                 primop1 = TYPE_MIN_VALUE (type);
2105                 val = 0;
2106                 break;
2107
2108               case LE_EXPR:
2109               case GT_EXPR:
2110                 primop1 = TYPE_MAX_VALUE (type);
2111                 val = 0;
2112                 break;
2113
2114               default:
2115                 break;
2116               }
2117           type = c_common_unsigned_type (type);
2118         }
2119
2120       if (TREE_CODE (primop0) != INTEGER_CST)
2121         {
2122           if (val == truthvalue_false_node)
2123             warning ("comparison is always false due to limited range of data type");
2124           if (val == truthvalue_true_node)
2125             warning ("comparison is always true due to limited range of data type");
2126         }
2127
2128       if (val != 0)
2129         {
2130           /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2131           if (TREE_SIDE_EFFECTS (primop0))
2132             return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
2133           return val;
2134         }
2135
2136       /* Value is not predetermined, but do the comparison
2137          in the type of the operand that is not constant.
2138          TYPE is already properly set.  */
2139     }
2140   else if (real1 && real2
2141            && (TYPE_PRECISION (TREE_TYPE (primop0))
2142                == TYPE_PRECISION (TREE_TYPE (primop1))))
2143     type = TREE_TYPE (primop0);
2144
2145   /* If args' natural types are both narrower than nominal type
2146      and both extend in the same manner, compare them
2147      in the type of the wider arg.
2148      Otherwise must actually extend both to the nominal
2149      common type lest different ways of extending
2150      alter the result.
2151      (eg, (short)-1 == (unsigned short)-1  should be 0.)  */
2152
2153   else if (unsignedp0 == unsignedp1 && real1 == real2
2154            && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
2155            && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
2156     {
2157       type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
2158       type = c_common_signed_or_unsigned_type (unsignedp0
2159                                                || TYPE_UNSIGNED (*restype_ptr),
2160                                                type);
2161       /* Make sure shorter operand is extended the right way
2162          to match the longer operand.  */
2163       primop0
2164         = convert (c_common_signed_or_unsigned_type (unsignedp0,
2165                                                      TREE_TYPE (primop0)),
2166                    primop0);
2167       primop1
2168         = convert (c_common_signed_or_unsigned_type (unsignedp1,
2169                                                      TREE_TYPE (primop1)),
2170                    primop1);
2171     }
2172   else
2173     {
2174       /* Here we must do the comparison on the nominal type
2175          using the args exactly as we received them.  */
2176       type = *restype_ptr;
2177       primop0 = op0;
2178       primop1 = op1;
2179
2180       if (!real1 && !real2 && integer_zerop (primop1)
2181           && TYPE_UNSIGNED (*restype_ptr))
2182         {
2183           tree value = 0;
2184           switch (code)
2185             {
2186             case GE_EXPR:
2187               /* All unsigned values are >= 0, so we warn if extra warnings
2188                  are requested.  However, if OP0 is a constant that is
2189                  >= 0, the signedness of the comparison isn't an issue,
2190                  so suppress the warning.  */
2191               if (extra_warnings && !in_system_header
2192                   && !(TREE_CODE (primop0) == INTEGER_CST
2193                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
2194                                                    primop0))))
2195                 warning ("comparison of unsigned expression >= 0 is always true");
2196               value = truthvalue_true_node;
2197               break;
2198
2199             case LT_EXPR:
2200               if (extra_warnings && !in_system_header
2201                   && !(TREE_CODE (primop0) == INTEGER_CST
2202                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
2203                                                    primop0))))
2204                 warning ("comparison of unsigned expression < 0 is always false");
2205               value = truthvalue_false_node;
2206               break;
2207
2208             default:
2209               break;
2210             }
2211
2212           if (value != 0)
2213             {
2214               /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2215               if (TREE_SIDE_EFFECTS (primop0))
2216                 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2217                                primop0, value);
2218               return value;
2219             }
2220         }
2221     }
2222
2223   *op0_ptr = convert (type, primop0);
2224   *op1_ptr = convert (type, primop1);
2225
2226   *restype_ptr = truthvalue_type_node;
2227
2228   return 0;
2229 }
2230 \f
2231 /* Return a tree for the sum or difference (RESULTCODE says which)
2232    of pointer PTROP and integer INTOP.  */
2233
2234 tree
2235 pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
2236 {
2237   tree size_exp;
2238
2239   /* The result is a pointer of the same type that is being added.  */
2240
2241   tree result_type = TREE_TYPE (ptrop);
2242
2243   if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
2244     {
2245       if (pedantic || warn_pointer_arith)
2246         pedwarn ("pointer of type %<void *%> used in arithmetic");
2247       size_exp = integer_one_node;
2248     }
2249   else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE)
2250     {
2251       if (pedantic || warn_pointer_arith)
2252         pedwarn ("pointer to a function used in arithmetic");
2253       size_exp = integer_one_node;
2254     }
2255   else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE)
2256     {
2257       if (pedantic || warn_pointer_arith)
2258         pedwarn ("pointer to member function used in arithmetic");
2259       size_exp = integer_one_node;
2260     }
2261   else
2262     size_exp = size_in_bytes (TREE_TYPE (result_type));
2263
2264   /* If what we are about to multiply by the size of the elements
2265      contains a constant term, apply distributive law
2266      and multiply that constant term separately.
2267      This helps produce common subexpressions.  */
2268
2269   if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
2270       && !TREE_CONSTANT (intop)
2271       && TREE_CONSTANT (TREE_OPERAND (intop, 1))
2272       && TREE_CONSTANT (size_exp)
2273       /* If the constant comes from pointer subtraction,
2274          skip this optimization--it would cause an error.  */
2275       && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
2276       /* If the constant is unsigned, and smaller than the pointer size,
2277          then we must skip this optimization.  This is because it could cause
2278          an overflow error if the constant is negative but INTOP is not.  */
2279       && (!TYPE_UNSIGNED (TREE_TYPE (intop))
2280           || (TYPE_PRECISION (TREE_TYPE (intop))
2281               == TYPE_PRECISION (TREE_TYPE (ptrop)))))
2282     {
2283       enum tree_code subcode = resultcode;
2284       tree int_type = TREE_TYPE (intop);
2285       if (TREE_CODE (intop) == MINUS_EXPR)
2286         subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
2287       /* Convert both subexpression types to the type of intop,
2288          because weird cases involving pointer arithmetic
2289          can result in a sum or difference with different type args.  */
2290       ptrop = build_binary_op (subcode, ptrop,
2291                                convert (int_type, TREE_OPERAND (intop, 1)), 1);
2292       intop = convert (int_type, TREE_OPERAND (intop, 0));
2293     }
2294
2295   /* Convert the integer argument to a type the same size as sizetype
2296      so the multiply won't overflow spuriously.  */
2297
2298   if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype)
2299       || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype))
2300     intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype),
2301                                              TYPE_UNSIGNED (sizetype)), intop);
2302
2303   /* Replace the integer argument with a suitable product by the object size.
2304      Do this multiplication as signed, then convert to the appropriate
2305      pointer type (actually unsigned integral).  */
2306
2307   intop = convert (result_type,
2308                    build_binary_op (MULT_EXPR, intop,
2309                                     convert (TREE_TYPE (intop), size_exp), 1));
2310
2311   /* Create the sum or difference.  */
2312   return fold (build2 (resultcode, result_type, ptrop, intop));
2313 }
2314 \f
2315 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
2316    or for an `if' or `while' statement or ?..: exp.  It should already
2317    have been validated to be of suitable type; otherwise, a bad
2318    diagnostic may result.
2319
2320    This preparation consists of taking the ordinary
2321    representation of an expression expr and producing a valid tree
2322    boolean expression describing whether expr is nonzero.  We could
2323    simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1),
2324    but we optimize comparisons, &&, ||, and !.
2325
2326    The resulting type should always be `truthvalue_type_node'.  */
2327
2328 tree
2329 c_common_truthvalue_conversion (tree expr)
2330 {
2331   switch (TREE_CODE (expr))
2332     {
2333     case EQ_EXPR:   case NE_EXPR:   case UNEQ_EXPR: case LTGT_EXPR:
2334     case LE_EXPR:   case GE_EXPR:   case LT_EXPR:   case GT_EXPR:
2335     case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR:
2336     case ORDERED_EXPR: case UNORDERED_EXPR:
2337       if (TREE_TYPE (expr) == truthvalue_type_node)
2338         return expr;
2339       return build2 (TREE_CODE (expr), truthvalue_type_node,
2340                      TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1));
2341
2342     case TRUTH_ANDIF_EXPR:
2343     case TRUTH_ORIF_EXPR:
2344     case TRUTH_AND_EXPR:
2345     case TRUTH_OR_EXPR:
2346     case TRUTH_XOR_EXPR:
2347       if (TREE_TYPE (expr) == truthvalue_type_node)
2348         return expr;
2349       return build2 (TREE_CODE (expr), truthvalue_type_node,
2350                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)),
2351                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)));
2352
2353     case TRUTH_NOT_EXPR:
2354       if (TREE_TYPE (expr) == truthvalue_type_node)
2355         return expr;
2356       return build1 (TREE_CODE (expr), truthvalue_type_node,
2357                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)));
2358
2359     case ERROR_MARK:
2360       return expr;
2361
2362     case INTEGER_CST:
2363       /* Avoid integer_zerop to ignore TREE_CONSTANT_OVERFLOW.  */
2364       return (TREE_INT_CST_LOW (expr) != 0 || TREE_INT_CST_HIGH (expr) != 0)
2365              ? truthvalue_true_node
2366              : truthvalue_false_node;
2367
2368     case REAL_CST:
2369       return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0)
2370              ? truthvalue_true_node
2371              : truthvalue_false_node;
2372
2373     case FUNCTION_DECL:
2374       expr = build_unary_op (ADDR_EXPR, expr, 0);
2375       /* Fall through.  */
2376
2377     case ADDR_EXPR:
2378       {
2379         if (TREE_CODE (TREE_OPERAND (expr, 0)) == FUNCTION_DECL
2380             && !DECL_WEAK (TREE_OPERAND (expr, 0)))
2381           {
2382             /* Common Ada/Pascal programmer's mistake.  We always warn
2383                about this since it is so bad.  */
2384             warning ("the address of %qD, will always evaluate as %<true%>",
2385                      TREE_OPERAND (expr, 0));
2386             return truthvalue_true_node;
2387           }
2388
2389         /* If we are taking the address of an external decl, it might be
2390            zero if it is weak, so we cannot optimize.  */
2391         if (DECL_P (TREE_OPERAND (expr, 0))
2392             && DECL_EXTERNAL (TREE_OPERAND (expr, 0)))
2393           break;
2394
2395         if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 0)))
2396           return build2 (COMPOUND_EXPR, truthvalue_type_node,
2397                          TREE_OPERAND (expr, 0), truthvalue_true_node);
2398         else
2399           return truthvalue_true_node;
2400       }
2401
2402     case COMPLEX_EXPR:
2403       return build_binary_op ((TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
2404                                ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
2405                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)),
2406                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
2407                               0);
2408
2409     case NEGATE_EXPR:
2410     case ABS_EXPR:
2411     case FLOAT_EXPR:
2412       /* These don't change whether an object is nonzero or zero.  */
2413       return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
2414
2415     case LROTATE_EXPR:
2416     case RROTATE_EXPR:
2417       /* These don't change whether an object is zero or nonzero, but
2418          we can't ignore them if their second arg has side-effects.  */
2419       if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2420         return build2 (COMPOUND_EXPR, truthvalue_type_node,
2421                        TREE_OPERAND (expr, 1),
2422                        c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)));
2423       else
2424         return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
2425
2426     case COND_EXPR:
2427       /* Distribute the conversion into the arms of a COND_EXPR.  */
2428       return fold (build3 (COND_EXPR, truthvalue_type_node,
2429                 TREE_OPERAND (expr, 0),
2430                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
2431                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 2))));
2432
2433     case CONVERT_EXPR:
2434       /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
2435          since that affects how `default_conversion' will behave.  */
2436       if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
2437           || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
2438         break;
2439       /* Fall through....  */
2440     case NOP_EXPR:
2441       /* If this is widening the argument, we can ignore it.  */
2442       if (TYPE_PRECISION (TREE_TYPE (expr))
2443           >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
2444         return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
2445       break;
2446
2447     case MINUS_EXPR:
2448       /* Perhaps reduce (x - y) != 0 to (x != y).  The expressions
2449          aren't guaranteed to the be same for modes that can represent
2450          infinity, since if x and y are both +infinity, or both
2451          -infinity, then x - y is not a number.
2452
2453          Note that this transformation is safe when x or y is NaN.
2454          (x - y) is then NaN, and both (x - y) != 0 and x != y will
2455          be false.  */
2456       if (HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (TREE_OPERAND (expr, 0)))))
2457         break;
2458       /* Fall through....  */
2459     case BIT_XOR_EXPR:
2460       /* This and MINUS_EXPR can be changed into a comparison of the
2461          two objects.  */
2462       if (TREE_TYPE (TREE_OPERAND (expr, 0))
2463           == TREE_TYPE (TREE_OPERAND (expr, 1)))
2464         return build_binary_op (NE_EXPR, TREE_OPERAND (expr, 0),
2465                                 TREE_OPERAND (expr, 1), 1);
2466       return build_binary_op (NE_EXPR, TREE_OPERAND (expr, 0),
2467                               fold (build1 (NOP_EXPR,
2468                                             TREE_TYPE (TREE_OPERAND (expr, 0)),
2469                                             TREE_OPERAND (expr, 1))), 1);
2470
2471     case BIT_AND_EXPR:
2472       if (integer_onep (TREE_OPERAND (expr, 1))
2473           && TREE_TYPE (expr) != truthvalue_type_node)
2474         /* Using convert here would cause infinite recursion.  */
2475         return build1 (NOP_EXPR, truthvalue_type_node, expr);
2476       break;
2477
2478     case MODIFY_EXPR:
2479       if (warn_parentheses && !TREE_NO_WARNING (expr))
2480         warning ("suggest parentheses around assignment used as truth value");
2481       break;
2482
2483     default:
2484       break;
2485     }
2486
2487   if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
2488     {
2489       tree t = save_expr (expr);
2490       return (build_binary_op
2491               ((TREE_SIDE_EFFECTS (expr)
2492                 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
2493         c_common_truthvalue_conversion (build_unary_op (REALPART_EXPR, t, 0)),
2494         c_common_truthvalue_conversion (build_unary_op (IMAGPART_EXPR, t, 0)),
2495                0));
2496     }
2497
2498   return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
2499 }
2500 \f
2501 static tree builtin_function_2 (const char *builtin_name, const char *name,
2502                                 tree builtin_type, tree type,
2503                                 enum built_in_function function_code,
2504                                 enum built_in_class cl, int library_name_p,
2505                                 bool nonansi_p,
2506                                 tree attrs);
2507
2508 /* Make a variant type in the proper way for C/C++, propagating qualifiers
2509    down to the element type of an array.  */
2510
2511 tree
2512 c_build_qualified_type (tree type, int type_quals)
2513 {
2514   if (type == error_mark_node)
2515     return type;
2516
2517   if (TREE_CODE (type) == ARRAY_TYPE)
2518     {
2519       tree t;
2520       tree element_type = c_build_qualified_type (TREE_TYPE (type),
2521                                                   type_quals);
2522
2523       /* See if we already have an identically qualified type.  */
2524       for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
2525         {
2526           if (TYPE_QUALS (strip_array_types (t)) == type_quals
2527               && TYPE_NAME (t) == TYPE_NAME (type)
2528               && TYPE_CONTEXT (t) == TYPE_CONTEXT (type)
2529               && attribute_list_equal (TYPE_ATTRIBUTES (t),
2530                                        TYPE_ATTRIBUTES (type)))
2531             break;
2532         }
2533       if (!t)
2534         {
2535           t = build_variant_type_copy (type);
2536           TREE_TYPE (t) = element_type;
2537         }
2538       return t;
2539     }
2540
2541   /* A restrict-qualified pointer type must be a pointer to object or
2542      incomplete type.  Note that the use of POINTER_TYPE_P also allows
2543      REFERENCE_TYPEs, which is appropriate for C++.  */
2544   if ((type_quals & TYPE_QUAL_RESTRICT)
2545       && (!POINTER_TYPE_P (type)
2546           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type))))
2547     {
2548       error ("invalid use of %<restrict%>");
2549       type_quals &= ~TYPE_QUAL_RESTRICT;
2550     }
2551
2552   return build_qualified_type (type, type_quals);
2553 }
2554
2555 /* Apply the TYPE_QUALS to the new DECL.  */
2556
2557 void
2558 c_apply_type_quals_to_decl (int type_quals, tree decl)
2559 {
2560   tree type = TREE_TYPE (decl);
2561
2562   if (type == error_mark_node)
2563     return;
2564
2565   if (((type_quals & TYPE_QUAL_CONST)
2566        || (type && TREE_CODE (type) == REFERENCE_TYPE))
2567       /* An object declared 'const' is only readonly after it is
2568          initialized.  We don't have any way of expressing this currently,
2569          so we need to be conservative and unset TREE_READONLY for types
2570          with constructors.  Otherwise aliasing code will ignore stores in
2571          an inline constructor.  */
2572       && !(type && TYPE_NEEDS_CONSTRUCTING (type)))
2573     TREE_READONLY (decl) = 1;
2574   if (type_quals & TYPE_QUAL_VOLATILE)
2575     {
2576       TREE_SIDE_EFFECTS (decl) = 1;
2577       TREE_THIS_VOLATILE (decl) = 1;
2578     }
2579   if (type_quals & TYPE_QUAL_RESTRICT)
2580     {
2581       while (type && TREE_CODE (type) == ARRAY_TYPE)
2582         /* Allow 'restrict' on arrays of pointers.
2583            FIXME currently we just ignore it.  */
2584         type = TREE_TYPE (type);
2585       if (!type
2586           || !POINTER_TYPE_P (type)
2587           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))
2588         error ("invalid use of %<restrict%>");
2589       else if (flag_strict_aliasing && type == TREE_TYPE (decl))
2590         /* Indicate we need to make a unique alias set for this pointer.
2591            We can't do it here because it might be pointing to an
2592            incomplete type.  */
2593         DECL_POINTER_ALIAS_SET (decl) = -2;
2594     }
2595 }
2596
2597 /* Hash function for the problem of multiple type definitions in
2598    different files.  This must hash all types that will compare
2599    equal via comptypes to the same value.  In practice it hashes
2600    on some of the simple stuff and leaves the details to comptypes.  */
2601
2602 static hashval_t
2603 c_type_hash (const void *p)
2604 {
2605   int i = 0;
2606   int shift, size;
2607   tree t = (tree) p;
2608   tree t2;
2609   switch (TREE_CODE (t))
2610     {
2611     /* For pointers, hash on pointee type plus some swizzling.  */
2612     case POINTER_TYPE:
2613       return c_type_hash (TREE_TYPE (t)) ^ 0x3003003;
2614     /* Hash on number of elements and total size.  */
2615     case ENUMERAL_TYPE:
2616       shift = 3;
2617       t2 = TYPE_VALUES (t);
2618       break;
2619     case RECORD_TYPE:
2620       shift = 0;
2621       t2 = TYPE_FIELDS (t);
2622       break;
2623     case QUAL_UNION_TYPE:
2624       shift = 1;
2625       t2 = TYPE_FIELDS (t);
2626       break;
2627     case UNION_TYPE:
2628       shift = 2;
2629       t2 = TYPE_FIELDS (t);
2630       break;
2631     default:
2632       gcc_unreachable ();
2633     }
2634   for (; t2; t2 = TREE_CHAIN (t2))
2635     i++;
2636   size = TREE_INT_CST_LOW (TYPE_SIZE (t));
2637   return ((size << 24) | (i << shift));
2638 }
2639
2640 static GTY((param_is (union tree_node))) htab_t type_hash_table;
2641
2642 /* Return the typed-based alias set for T, which may be an expression
2643    or a type.  Return -1 if we don't do anything special.  */
2644
2645 HOST_WIDE_INT
2646 c_common_get_alias_set (tree t)
2647 {
2648   tree u;
2649   PTR *slot;
2650
2651   /* Permit type-punning when accessing a union, provided the access
2652      is directly through the union.  For example, this code does not
2653      permit taking the address of a union member and then storing
2654      through it.  Even the type-punning allowed here is a GCC
2655      extension, albeit a common and useful one; the C standard says
2656      that such accesses have implementation-defined behavior.  */
2657   for (u = t;
2658        TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
2659        u = TREE_OPERAND (u, 0))
2660     if (TREE_CODE (u) == COMPONENT_REF
2661         && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
2662       return 0;
2663
2664   /* That's all the expressions we handle specially.  */
2665   if (!TYPE_P (t))
2666     return -1;
2667
2668   /* The C standard guarantees that any object may be accessed via an
2669      lvalue that has character type.  */
2670   if (t == char_type_node
2671       || t == signed_char_type_node
2672       || t == unsigned_char_type_node)
2673     return 0;
2674
2675   /* If it has the may_alias attribute, it can alias anything.  */
2676   if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (t)))
2677     return 0;
2678
2679   /* The C standard specifically allows aliasing between signed and
2680      unsigned variants of the same type.  We treat the signed
2681      variant as canonical.  */
2682   if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t))
2683     {
2684       tree t1 = c_common_signed_type (t);
2685
2686       /* t1 == t can happen for boolean nodes which are always unsigned.  */
2687       if (t1 != t)
2688         return get_alias_set (t1);
2689     }
2690   else if (POINTER_TYPE_P (t))
2691     {
2692       tree t1;
2693
2694       /* Unfortunately, there is no canonical form of a pointer type.
2695          In particular, if we have `typedef int I', then `int *', and
2696          `I *' are different types.  So, we have to pick a canonical
2697          representative.  We do this below.
2698
2699          Technically, this approach is actually more conservative that
2700          it needs to be.  In particular, `const int *' and `int *'
2701          should be in different alias sets, according to the C and C++
2702          standard, since their types are not the same, and so,
2703          technically, an `int **' and `const int **' cannot point at
2704          the same thing.
2705
2706          But, the standard is wrong.  In particular, this code is
2707          legal C++:
2708
2709             int *ip;
2710             int **ipp = &ip;
2711             const int* const* cipp = ipp;
2712
2713          And, it doesn't make sense for that to be legal unless you
2714          can dereference IPP and CIPP.  So, we ignore cv-qualifiers on
2715          the pointed-to types.  This issue has been reported to the
2716          C++ committee.  */
2717       t1 = build_type_no_quals (t);
2718       if (t1 != t)
2719         return get_alias_set (t1);
2720     }
2721
2722   /* Handle the case of multiple type nodes referring to "the same" type,
2723      which occurs with IMA.  These share an alias set.  FIXME:  Currently only
2724      C90 is handled.  (In C99 type compatibility is not transitive, which
2725      complicates things mightily. The alias set splay trees can theoretically
2726      represent this, but insertion is tricky when you consider all the
2727      different orders things might arrive in.) */
2728
2729   if (c_language != clk_c || flag_isoc99)
2730     return -1;
2731
2732   /* Save time if there's only one input file.  */
2733   if (num_in_fnames == 1)
2734     return -1;
2735
2736   /* Pointers need special handling if they point to any type that
2737      needs special handling (below).  */
2738   if (TREE_CODE (t) == POINTER_TYPE)
2739     {
2740       tree t2;
2741       /* Find bottom type under any nested POINTERs.  */
2742       for (t2 = TREE_TYPE (t);
2743      TREE_CODE (t2) == POINTER_TYPE;
2744      t2 = TREE_TYPE (t2))
2745   ;
2746       if (TREE_CODE (t2) != RECORD_TYPE
2747     && TREE_CODE (t2) != ENUMERAL_TYPE
2748     && TREE_CODE (t2) != QUAL_UNION_TYPE
2749     && TREE_CODE (t2) != UNION_TYPE)
2750   return -1;
2751       if (TYPE_SIZE (t2) == 0)
2752   return -1;
2753     }
2754   /* These are the only cases that need special handling.  */
2755   if (TREE_CODE (t) != RECORD_TYPE
2756       && TREE_CODE (t) != ENUMERAL_TYPE
2757       && TREE_CODE (t) != QUAL_UNION_TYPE
2758       && TREE_CODE (t) != UNION_TYPE
2759       && TREE_CODE (t) != POINTER_TYPE)
2760     return -1;
2761   /* Undefined? */
2762   if (TYPE_SIZE (t) == 0)
2763     return -1;
2764
2765   /* Look up t in hash table.  Only one of the compatible types within each
2766      alias set is recorded in the table.  */
2767   if (!type_hash_table)
2768     type_hash_table = htab_create_ggc (1021, c_type_hash,
2769             (htab_eq) lang_hooks.types_compatible_p,
2770             NULL);
2771   slot = htab_find_slot (type_hash_table, t, INSERT);
2772   if (*slot != NULL)
2773     {
2774       TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot);
2775       return TYPE_ALIAS_SET ((tree)*slot);
2776     }
2777   else
2778     /* Our caller will assign and record (in t) a new alias set; all we need
2779        to do is remember t in the hash table.  */
2780     *slot = t;
2781
2782   return -1;
2783 }
2784 \f
2785 /* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where the
2786    second parameter indicates which OPERATOR is being applied.  The COMPLAIN
2787    flag controls whether we should diagnose possibly ill-formed
2788    constructs or not.  */
2789 tree
2790 c_sizeof_or_alignof_type (tree type, enum tree_code op, int complain)
2791 {
2792   const char *op_name;
2793   tree value = NULL;
2794   enum tree_code type_code = TREE_CODE (type);
2795
2796   gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
2797   op_name = op == SIZEOF_EXPR ? "sizeof" : "__alignof__";
2798
2799   if (type_code == FUNCTION_TYPE)
2800     {
2801       if (op == SIZEOF_EXPR)
2802         {
2803           if (complain && (pedantic || warn_pointer_arith))
2804             pedwarn ("invalid application of %<sizeof%> to a function type");
2805           value = size_one_node;
2806         }
2807       else
2808         value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);
2809     }
2810   else if (type_code == VOID_TYPE || type_code == ERROR_MARK)
2811     {
2812       if (type_code == VOID_TYPE
2813           && complain && (pedantic || warn_pointer_arith))
2814         pedwarn ("invalid application of %qs to a void type", op_name);
2815       value = size_one_node;
2816     }
2817   else if (!COMPLETE_TYPE_P (type))
2818     {
2819       if (complain)
2820         error ("invalid application of %qs to incomplete type %qT ",
2821                op_name, type);
2822       value = size_zero_node;
2823     }
2824   else
2825     {
2826       if (op == (enum tree_code) SIZEOF_EXPR)
2827         /* Convert in case a char is more than one unit.  */
2828         value = size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
2829                             size_int (TYPE_PRECISION (char_type_node)
2830                                       / BITS_PER_UNIT));
2831       else
2832         value = size_int (TYPE_ALIGN_UNIT (type));
2833     }
2834
2835   /* VALUE will have an integer type with TYPE_IS_SIZETYPE set.
2836      TYPE_IS_SIZETYPE means that certain things (like overflow) will
2837      never happen.  However, this node should really have type
2838      `size_t', which is just a typedef for an ordinary integer type.  */
2839   value = fold (build1 (NOP_EXPR, size_type_node, value));
2840   gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value)));
2841
2842   return value;
2843 }
2844
2845 /* Implement the __alignof keyword: Return the minimum required
2846    alignment of EXPR, measured in bytes.  For VAR_DECL's and
2847    FIELD_DECL's return DECL_ALIGN (which can be set from an
2848    "aligned" __attribute__ specification).  */
2849
2850 tree
2851 c_alignof_expr (tree expr)
2852 {
2853   tree t;
2854
2855   if (TREE_CODE (expr) == VAR_DECL)
2856     t = size_int (DECL_ALIGN_UNIT (expr));
2857
2858   else if (TREE_CODE (expr) == COMPONENT_REF
2859            && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1)))
2860     {
2861       error ("%<__alignof%> applied to a bit-field");
2862       t = size_one_node;
2863     }
2864   else if (TREE_CODE (expr) == COMPONENT_REF
2865            && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL)
2866     t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1)));
2867
2868   else if (TREE_CODE (expr) == INDIRECT_REF)
2869     {
2870       tree t = TREE_OPERAND (expr, 0);
2871       tree best = t;
2872       int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
2873
2874       while (TREE_CODE (t) == NOP_EXPR
2875              && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE)
2876         {
2877           int thisalign;
2878
2879           t = TREE_OPERAND (t, 0);
2880           thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
2881           if (thisalign > bestalign)
2882             best = t, bestalign = thisalign;
2883         }
2884       return c_alignof (TREE_TYPE (TREE_TYPE (best)));
2885     }
2886   else
2887     return c_alignof (TREE_TYPE (expr));
2888
2889   return fold (build1 (NOP_EXPR, size_type_node, t));
2890 }
2891 \f
2892 /* Handle C and C++ default attributes.  */
2893
2894 enum built_in_attribute
2895 {
2896 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
2897 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
2898 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
2899 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
2900 #include "builtin-attrs.def"
2901 #undef DEF_ATTR_NULL_TREE
2902 #undef DEF_ATTR_INT
2903 #undef DEF_ATTR_IDENT
2904 #undef DEF_ATTR_TREE_LIST
2905   ATTR_LAST
2906 };
2907
2908 static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
2909
2910 static void c_init_attributes (void);
2911
2912 /* Build tree nodes and builtin functions common to both C and C++ language
2913    frontends.  */
2914
2915 void
2916 c_common_nodes_and_builtins (void)
2917 {
2918   enum builtin_type
2919   {
2920 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
2921 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
2922 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
2923 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
2924 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
2925 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
2926 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
2927 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
2928 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
2929 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
2930 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
2931 #include "builtin-types.def"
2932 #undef DEF_PRIMITIVE_TYPE
2933 #undef DEF_FUNCTION_TYPE_0
2934 #undef DEF_FUNCTION_TYPE_1
2935 #undef DEF_FUNCTION_TYPE_2
2936 #undef DEF_FUNCTION_TYPE_3
2937 #undef DEF_FUNCTION_TYPE_4
2938 #undef DEF_FUNCTION_TYPE_VAR_0
2939 #undef DEF_FUNCTION_TYPE_VAR_1
2940 #undef DEF_FUNCTION_TYPE_VAR_2
2941 #undef DEF_FUNCTION_TYPE_VAR_3
2942 #undef DEF_POINTER_TYPE
2943     BT_LAST
2944   };
2945
2946   typedef enum builtin_type builtin_type;
2947
2948   tree builtin_types[(int) BT_LAST];
2949   int wchar_type_size;
2950   tree array_domain_type;
2951   tree va_list_ref_type_node;
2952   tree va_list_arg_type_node;
2953
2954   /* Define `int' and `char' first so that dbx will output them first.  */
2955   record_builtin_type (RID_INT, NULL, integer_type_node);
2956   record_builtin_type (RID_CHAR, "char", char_type_node);
2957
2958   /* `signed' is the same as `int'.  FIXME: the declarations of "signed",
2959      "unsigned long", "long long unsigned" and "unsigned short" were in C++
2960      but not C.  Are the conditionals here needed?  */
2961   if (c_dialect_cxx ())
2962     record_builtin_type (RID_SIGNED, NULL, integer_type_node);
2963   record_builtin_type (RID_LONG, "long int", long_integer_type_node);
2964   record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
2965   record_builtin_type (RID_MAX, "long unsigned int",
2966                        long_unsigned_type_node);
2967   if (c_dialect_cxx ())
2968     record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
2969   record_builtin_type (RID_MAX, "long long int",
2970                        long_long_integer_type_node);
2971   record_builtin_type (RID_MAX, "long long unsigned int",
2972                        long_long_unsigned_type_node);
2973   if (c_dialect_cxx ())
2974     record_builtin_type (RID_MAX, "long long unsigned",
2975                          long_long_unsigned_type_node);
2976   record_builtin_type (RID_SHORT, "short int", short_integer_type_node);
2977   record_builtin_type (RID_MAX, "short unsigned int",
2978                        short_unsigned_type_node);
2979   if (c_dialect_cxx ())
2980     record_builtin_type (RID_MAX, "unsigned short",
2981                          short_unsigned_type_node);
2982
2983   /* Define both `signed char' and `unsigned char'.  */
2984   record_builtin_type (RID_MAX, "signed char", signed_char_type_node);
2985   record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node);
2986
2987   /* These are types that c_common_type_for_size and
2988      c_common_type_for_mode use.  */
2989   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
2990                                          intQI_type_node));
2991   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
2992                                          intHI_type_node));
2993   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
2994                                          intSI_type_node));
2995   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
2996                                          intDI_type_node));
2997 #if HOST_BITS_PER_WIDE_INT >= 64
2998   if (targetm.scalar_mode_supported_p (TImode))
2999     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3000                                            get_identifier ("__int128_t"),
3001                                            intTI_type_node));
3002 #endif
3003   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3004                                          unsigned_intQI_type_node));
3005   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3006                                          unsigned_intHI_type_node));
3007   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3008                                          unsigned_intSI_type_node));
3009   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3010                                          unsigned_intDI_type_node));
3011 #if HOST_BITS_PER_WIDE_INT >= 64
3012   if (targetm.scalar_mode_supported_p (TImode))
3013     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3014                                            get_identifier ("__uint128_t"),
3015                                            unsigned_intTI_type_node));
3016 #endif
3017
3018   /* Create the widest literal types.  */
3019   widest_integer_literal_type_node
3020     = make_signed_type (HOST_BITS_PER_WIDE_INT * 2);
3021   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3022                                          widest_integer_literal_type_node));
3023
3024   widest_unsigned_literal_type_node
3025     = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2);
3026   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3027                                          widest_unsigned_literal_type_node));
3028
3029   /* `unsigned long' is the standard type for sizeof.
3030      Note that stddef.h uses `unsigned long',
3031      and this must agree, even if long and int are the same size.  */
3032   size_type_node =
3033     TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE)));
3034   signed_size_type_node = c_common_signed_type (size_type_node);
3035   set_sizetype (size_type_node);
3036
3037   pid_type_node =
3038     TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE)));
3039
3040   build_common_tree_nodes_2 (flag_short_double);
3041
3042   record_builtin_type (RID_FLOAT, NULL, float_type_node);
3043   record_builtin_type (RID_DOUBLE, NULL, double_type_node);
3044   record_builtin_type (RID_MAX, "long double", long_double_type_node);
3045
3046   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3047                                          get_identifier ("complex int"),
3048                                          complex_integer_type_node));
3049   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3050                                          get_identifier ("complex float"),
3051                                          complex_float_type_node));
3052   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3053                                          get_identifier ("complex double"),
3054                                          complex_double_type_node));
3055   lang_hooks.decls.pushdecl
3056     (build_decl (TYPE_DECL, get_identifier ("complex long double"),
3057                  complex_long_double_type_node));
3058
3059   if (c_dialect_cxx ())
3060     /* For C++, make fileptr_type_node a distinct void * type until
3061        FILE type is defined.  */
3062     fileptr_type_node = build_variant_type_copy (ptr_type_node);
3063
3064   record_builtin_type (RID_VOID, NULL, void_type_node);
3065
3066   /* This node must not be shared.  */
3067   void_zero_node = make_node (INTEGER_CST);
3068   TREE_TYPE (void_zero_node) = void_type_node;
3069
3070   void_list_node = build_void_list_node ();
3071
3072   /* Make a type to be the domain of a few array types
3073      whose domains don't really matter.
3074      200 is small enough that it always fits in size_t
3075      and large enough that it can hold most function names for the
3076      initializations of __FUNCTION__ and __PRETTY_FUNCTION__.  */
3077   array_domain_type = build_index_type (size_int (200));
3078
3079   /* Make a type for arrays of characters.
3080      With luck nothing will ever really depend on the length of this
3081      array type.  */
3082   char_array_type_node
3083     = build_array_type (char_type_node, array_domain_type);
3084
3085   /* Likewise for arrays of ints.  */
3086   int_array_type_node
3087     = build_array_type (integer_type_node, array_domain_type);
3088
3089   string_type_node = build_pointer_type (char_type_node);
3090   const_string_type_node
3091     = build_pointer_type (build_qualified_type
3092                           (char_type_node, TYPE_QUAL_CONST));
3093
3094   /* This is special for C++ so functions can be overloaded.  */
3095   wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE);
3096   wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node));
3097   wchar_type_size = TYPE_PRECISION (wchar_type_node);
3098   if (c_dialect_cxx ())
3099     {
3100       if (TYPE_UNSIGNED (wchar_type_node))
3101         wchar_type_node = make_unsigned_type (wchar_type_size);
3102       else
3103         wchar_type_node = make_signed_type (wchar_type_size);
3104       record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node);
3105     }
3106   else
3107     {
3108       signed_wchar_type_node = c_common_signed_type (wchar_type_node);
3109       unsigned_wchar_type_node = c_common_unsigned_type (wchar_type_node);
3110     }
3111
3112   /* This is for wide string constants.  */
3113   wchar_array_type_node
3114     = build_array_type (wchar_type_node, array_domain_type);
3115
3116   wint_type_node =
3117     TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE)));
3118
3119   intmax_type_node =
3120     TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE)));
3121   uintmax_type_node =
3122     TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE)));
3123
3124   default_function_type = build_function_type (integer_type_node, NULL_TREE);
3125   ptrdiff_type_node
3126     = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE)));
3127   unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node);
3128
3129   lang_hooks.decls.pushdecl
3130     (build_decl (TYPE_DECL, get_identifier ("__builtin_va_list"),
3131                  va_list_type_node));
3132
3133   if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
3134     {
3135       va_list_arg_type_node = va_list_ref_type_node =
3136         build_pointer_type (TREE_TYPE (va_list_type_node));
3137     }
3138   else
3139     {
3140       va_list_arg_type_node = va_list_type_node;
3141       va_list_ref_type_node = build_reference_type (va_list_type_node);
3142     }
3143
3144 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
3145   builtin_types[(int) ENUM] = VALUE;
3146 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN)               \
3147   builtin_types[(int) ENUM]                             \
3148     = build_function_type (builtin_types[(int) RETURN], \
3149                            void_list_node);
3150 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1)                         \
3151   builtin_types[(int) ENUM]                                             \
3152     = build_function_type (builtin_types[(int) RETURN],                 \
3153                            tree_cons (NULL_TREE,                        \
3154                                       builtin_types[(int) ARG1],        \
3155                                       void_list_node));
3156 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2)   \
3157   builtin_types[(int) ENUM]                             \
3158     = build_function_type                               \
3159       (builtin_types[(int) RETURN],                     \
3160        tree_cons (NULL_TREE,                            \
3161                   builtin_types[(int) ARG1],            \
3162                   tree_cons (NULL_TREE,                 \
3163                              builtin_types[(int) ARG2], \
3164                              void_list_node)));
3165 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3)              \
3166   builtin_types[(int) ENUM]                                              \
3167     = build_function_type                                                \
3168       (builtin_types[(int) RETURN],                                      \
3169        tree_cons (NULL_TREE,                                             \
3170                   builtin_types[(int) ARG1],                             \
3171                   tree_cons (NULL_TREE,                                  \
3172                              builtin_types[(int) ARG2],                  \
3173                              tree_cons (NULL_TREE,                       \
3174                                         builtin_types[(int) ARG3],       \
3175                                         void_list_node))));
3176 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4)       \
3177   builtin_types[(int) ENUM]                                             \
3178     = build_function_type                                               \
3179       (builtin_types[(int) RETURN],                                     \
3180        tree_cons (NULL_TREE,                                            \
3181                   builtin_types[(int) ARG1],                            \
3182                   tree_cons (NULL_TREE,                                 \
3183                              builtin_types[(int) ARG2],                 \
3184                              tree_cons                                  \
3185                              (NULL_TREE,                                \
3186                               builtin_types[(int) ARG3],                \
3187                               tree_cons (NULL_TREE,                     \
3188                                          builtin_types[(int) ARG4],     \
3189                                          void_list_node)))));
3190 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN)                           \
3191   builtin_types[(int) ENUM]                                             \
3192     = build_function_type (builtin_types[(int) RETURN], NULL_TREE);
3193 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1)                      \
3194    builtin_types[(int) ENUM]                                             \
3195     = build_function_type (builtin_types[(int) RETURN],          \
3196                            tree_cons (NULL_TREE,                         \
3197                                       builtin_types[(int) ARG1],         \
3198                                       NULL_TREE));
3199
3200 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2)       \
3201    builtin_types[(int) ENUM]                                    \
3202     = build_function_type                                       \
3203       (builtin_types[(int) RETURN],                             \
3204        tree_cons (NULL_TREE,                                    \
3205                   builtin_types[(int) ARG1],                    \
3206                   tree_cons (NULL_TREE,                         \
3207                              builtin_types[(int) ARG2],         \
3208                              NULL_TREE)));
3209
3210 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3)         \
3211    builtin_types[(int) ENUM]                                            \
3212     = build_function_type                                               \
3213       (builtin_types[(int) RETURN],                                     \
3214        tree_cons (NULL_TREE,                                            \
3215                   builtin_types[(int) ARG1],                            \
3216                   tree_cons (NULL_TREE,                                 \
3217                              builtin_types[(int) ARG2],                 \
3218                              tree_cons (NULL_TREE,                      \
3219                                         builtin_types[(int) ARG3],      \
3220                                         NULL_TREE))));
3221
3222 #define DEF_POINTER_TYPE(ENUM, TYPE)                    \
3223   builtin_types[(int) ENUM]                             \
3224     = build_pointer_type (builtin_types[(int) TYPE]);
3225 #include "builtin-types.def"
3226 #undef DEF_PRIMITIVE_TYPE
3227 #undef DEF_FUNCTION_TYPE_1
3228 #undef DEF_FUNCTION_TYPE_2
3229 #undef DEF_FUNCTION_TYPE_3
3230 #undef DEF_FUNCTION_TYPE_4
3231 #undef DEF_FUNCTION_TYPE_VAR_0
3232 #undef DEF_FUNCTION_TYPE_VAR_1
3233 #undef DEF_FUNCTION_TYPE_VAR_2
3234 #undef DEF_FUNCTION_TYPE_VAR_3
3235 #undef DEF_POINTER_TYPE
3236
3237   c_init_attributes ();
3238
3239 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
3240                     NONANSI_P, ATTRS, IMPLICIT, COND)                   \
3241   if (NAME && COND)                                                     \
3242     {                                                                   \
3243       tree decl;                                                        \
3244                                                                         \
3245       gcc_assert (!strncmp (NAME, "__builtin_",                         \
3246                             strlen ("__builtin_")));                    \
3247                                                                         \
3248       if (!BOTH_P)                                                      \
3249         decl = lang_hooks.builtin_function (NAME, builtin_types[TYPE],  \
3250                                  ENUM,                                  \
3251                                  CLASS,                                 \
3252                                  (FALLBACK_P                            \
3253                                   ? (NAME + strlen ("__builtin_"))      \
3254                                   : NULL),                              \
3255                                  built_in_attributes[(int) ATTRS]);     \
3256       else                                                              \
3257         decl = builtin_function_2 (NAME,                                \
3258                                    NAME + strlen ("__builtin_"),        \
3259                                    builtin_types[TYPE],                 \
3260                                    builtin_types[LIBTYPE],              \
3261                                    ENUM,                                \
3262                                    CLASS,                               \
3263                                    FALLBACK_P,                          \
3264                                    NONANSI_P,                           \
3265                                    built_in_attributes[(int) ATTRS]);   \
3266                                                                         \
3267       built_in_decls[(int) ENUM] = decl;                                \
3268       if (IMPLICIT)                                                     \
3269         implicit_built_in_decls[(int) ENUM] = decl;                     \
3270     }
3271 #include "builtins.def"
3272 #undef DEF_BUILTIN
3273
3274   build_common_builtin_nodes ();
3275
3276   targetm.init_builtins ();
3277   if (flag_mudflap)
3278     mudflap_init ();
3279
3280   main_identifier_node = get_identifier ("main");
3281 }
3282
3283 /* Look up the function in built_in_decls that corresponds to DECL
3284    and set ASMSPEC as its user assembler name.  DECL must be a
3285    function decl that declares a builtin.  */
3286
3287 void
3288 set_builtin_user_assembler_name (tree decl, const char *asmspec)
3289 {
3290   tree builtin;
3291   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
3292               && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
3293               && asmspec != 0);
3294
3295   builtin = built_in_decls [DECL_FUNCTION_CODE (decl)];
3296   set_user_assembler_name (builtin, asmspec);
3297   if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMCPY)
3298     init_block_move_fn (asmspec);
3299   else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMSET)
3300     init_block_clear_fn (asmspec);
3301 }
3302
3303 tree
3304 build_va_arg (tree expr, tree type)
3305 {
3306   return build1 (VA_ARG_EXPR, type, expr);
3307 }
3308
3309
3310 /* Linked list of disabled built-in functions.  */
3311
3312 typedef struct disabled_builtin
3313 {
3314   const char *name;
3315   struct disabled_builtin *next;
3316 } disabled_builtin;
3317 static disabled_builtin *disabled_builtins = NULL;
3318
3319 static bool builtin_function_disabled_p (const char *);
3320
3321 /* Disable a built-in function specified by -fno-builtin-NAME.  If NAME
3322    begins with "__builtin_", give an error.  */
3323
3324 void
3325 disable_builtin_function (const char *name)
3326 {
3327   if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
3328     error ("cannot disable built-in function %qs", name);
3329   else
3330     {
3331       disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin);
3332       new_disabled_builtin->name = name;
3333       new_disabled_builtin->next = disabled_builtins;
3334       disabled_builtins = new_disabled_builtin;
3335     }
3336 }
3337
3338
3339 /* Return true if the built-in function NAME has been disabled, false
3340    otherwise.  */
3341
3342 static bool
3343 builtin_function_disabled_p (const char *name)
3344 {
3345   disabled_builtin *p;
3346   for (p = disabled_builtins; p != NULL; p = p->next)
3347     {
3348       if (strcmp (name, p->name) == 0)
3349         return true;
3350     }
3351   return false;
3352 }
3353
3354
3355 /* Possibly define a builtin function with one or two names.  BUILTIN_NAME
3356    is an __builtin_-prefixed name; NAME is the ordinary name; one or both
3357    of these may be NULL (though both being NULL is useless).
3358    BUILTIN_TYPE is the type of the __builtin_-prefixed function;
3359    TYPE is the type of the function with the ordinary name.  These
3360    may differ if the ordinary name is declared with a looser type to avoid
3361    conflicts with headers.  FUNCTION_CODE and CL are as for
3362    builtin_function.  If LIBRARY_NAME_P is nonzero, NAME is passed as
3363    the LIBRARY_NAME parameter to builtin_function when declaring BUILTIN_NAME.
3364    If NONANSI_P is true, the name NAME is treated as a non-ANSI name;
3365    ATTRS is the tree list representing the builtin's function attributes.
3366    Returns the declaration of BUILTIN_NAME, if any, otherwise
3367    the declaration of NAME.  Does not declare NAME if flag_no_builtin,
3368    or if NONANSI_P and flag_no_nonansi_builtin.  */
3369
3370 static tree
3371 builtin_function_2 (const char *builtin_name, const char *name,
3372                     tree builtin_type, tree type,
3373                     enum built_in_function function_code,
3374                     enum built_in_class cl, int library_name_p,
3375                     bool nonansi_p, tree attrs)
3376 {
3377   tree bdecl = NULL_TREE;
3378   tree decl = NULL_TREE;
3379
3380   if (builtin_name != 0)
3381     bdecl = lang_hooks.builtin_function (builtin_name, builtin_type,
3382                                          function_code, cl,
3383                                          library_name_p ? name : NULL, attrs);
3384
3385   if (name != 0 && !flag_no_builtin && !builtin_function_disabled_p (name)
3386       && !(nonansi_p && flag_no_nonansi_builtin))
3387     decl = lang_hooks.builtin_function (name, type, function_code, cl,
3388                                         NULL, attrs);
3389
3390   return (bdecl != 0 ? bdecl : decl);
3391 }
3392 \f
3393 /* Nonzero if the type T promotes to int.  This is (nearly) the
3394    integral promotions defined in ISO C99 6.3.1.1/2.  */
3395
3396 bool
3397 c_promoting_integer_type_p (tree t)
3398 {
3399   switch (TREE_CODE (t))
3400     {
3401     case INTEGER_TYPE:
3402       return (TYPE_MAIN_VARIANT (t) == char_type_node
3403               || TYPE_MAIN_VARIANT (t) == signed_char_type_node
3404               || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node
3405               || TYPE_MAIN_VARIANT (t) == short_integer_type_node
3406               || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node
3407               || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node));
3408
3409     case ENUMERAL_TYPE:
3410       /* ??? Technically all enumerations not larger than an int
3411          promote to an int.  But this is used along code paths
3412          that only want to notice a size change.  */
3413       return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node);
3414
3415     case BOOLEAN_TYPE:
3416       return 1;
3417
3418     default:
3419       return 0;
3420     }
3421 }
3422
3423 /* Return 1 if PARMS specifies a fixed number of parameters
3424    and none of their types is affected by default promotions.  */
3425
3426 int
3427 self_promoting_args_p (tree parms)
3428 {
3429   tree t;
3430   for (t = parms; t; t = TREE_CHAIN (t))
3431     {
3432       tree type = TREE_VALUE (t);
3433
3434       if (TREE_CHAIN (t) == 0 && type != void_type_node)
3435         return 0;
3436
3437       if (type == 0)
3438         return 0;
3439
3440       if (TYPE_MAIN_VARIANT (type) == float_type_node)
3441         return 0;
3442
3443       if (c_promoting_integer_type_p (type))
3444         return 0;
3445     }
3446   return 1;
3447 }
3448
3449 /* Recursively examines the array elements of TYPE, until a non-array
3450    element type is found.  */
3451
3452 tree
3453 strip_array_types (tree type)
3454 {
3455   while (TREE_CODE (type) == ARRAY_TYPE)
3456     type = TREE_TYPE (type);
3457
3458   return type;
3459 }
3460
3461 /* Recursively remove any '*' or '&' operator from TYPE.  */
3462 tree
3463 strip_pointer_operator (tree t)
3464 {
3465   while (POINTER_TYPE_P (t))
3466     t = TREE_TYPE (t);
3467   return t;
3468 }
3469
3470 /* Used to compare case labels.  K1 and K2 are actually tree nodes
3471    representing case labels, or NULL_TREE for a `default' label.
3472    Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
3473    K2, and 0 if K1 and K2 are equal.  */
3474
3475 int
3476 case_compare (splay_tree_key k1, splay_tree_key k2)
3477 {
3478   /* Consider a NULL key (such as arises with a `default' label) to be
3479      smaller than anything else.  */
3480   if (!k1)
3481     return k2 ? -1 : 0;
3482   else if (!k2)
3483     return k1 ? 1 : 0;
3484
3485   return tree_int_cst_compare ((tree) k1, (tree) k2);
3486 }
3487
3488 /* Process a case label for the range LOW_VALUE ... HIGH_VALUE.  If
3489    LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is
3490    actually a `default' label.  If only HIGH_VALUE is NULL_TREE, then
3491    case label was declared using the usual C/C++ syntax, rather than
3492    the GNU case range extension.  CASES is a tree containing all the
3493    case ranges processed so far; COND is the condition for the
3494    switch-statement itself.  Returns the CASE_LABEL_EXPR created, or
3495    ERROR_MARK_NODE if no CASE_LABEL_EXPR is created.  */
3496
3497 tree
3498 c_add_case_label (splay_tree cases, tree cond, tree orig_type,
3499                   tree low_value, tree high_value)
3500 {
3501   tree type;
3502   tree label;
3503   tree case_label;
3504   splay_tree_node node;
3505
3506   /* Create the LABEL_DECL itself.  */
3507   label = create_artificial_label ();
3508
3509   /* If there was an error processing the switch condition, bail now
3510      before we get more confused.  */
3511   if (!cond || cond == error_mark_node)
3512     goto error_out;
3513
3514   if ((low_value && TREE_TYPE (low_value)
3515        && POINTER_TYPE_P (TREE_TYPE (low_value)))
3516       || (high_value && TREE_TYPE (high_value)
3517           && POINTER_TYPE_P (TREE_TYPE (high_value))))
3518     {
3519       error ("pointers are not permitted as case values");
3520       goto error_out;
3521     }
3522
3523   /* Case ranges are a GNU extension.  */
3524   if (high_value && pedantic)
3525     pedwarn ("range expressions in switch statements are non-standard");
3526
3527   type = TREE_TYPE (cond);
3528   if (low_value)
3529     {
3530       low_value = check_case_value (low_value);
3531       low_value = convert_and_check (type, low_value);
3532     }
3533   if (high_value)
3534     {
3535       high_value = check_case_value (high_value);
3536       high_value = convert_and_check (type, high_value);
3537     }
3538
3539   /* If an error has occurred, bail out now.  */
3540   if (low_value == error_mark_node || high_value == error_mark_node)
3541     goto error_out;
3542
3543   /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
3544      really a case range, even though it was written that way.  Remove
3545      the HIGH_VALUE to simplify later processing.  */
3546   if (tree_int_cst_equal (low_value, high_value))
3547     high_value = NULL_TREE;
3548   if (low_value && high_value
3549       && !tree_int_cst_lt (low_value, high_value))
3550     warning ("empty range specified");
3551
3552   /* See if the case is in range of the type of the original testing
3553      expression.  If both low_value and high_value are out of range,
3554      don't insert the case label and return NULL_TREE.  */
3555   if (low_value
3556       && !check_case_bounds (type, orig_type,
3557                              &low_value, high_value ? &high_value : NULL))
3558     return NULL_TREE;
3559
3560   /* Look up the LOW_VALUE in the table of case labels we already
3561      have.  */
3562   node = splay_tree_lookup (cases, (splay_tree_key) low_value);
3563   /* If there was not an exact match, check for overlapping ranges.
3564      There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
3565      that's a `default' label and the only overlap is an exact match.  */
3566   if (!node && (low_value || high_value))
3567     {
3568       splay_tree_node low_bound;
3569       splay_tree_node high_bound;
3570
3571       /* Even though there wasn't an exact match, there might be an
3572          overlap between this case range and another case range.
3573          Since we've (inductively) not allowed any overlapping case
3574          ranges, we simply need to find the greatest low case label
3575          that is smaller that LOW_VALUE, and the smallest low case
3576          label that is greater than LOW_VALUE.  If there is an overlap
3577          it will occur in one of these two ranges.  */
3578       low_bound = splay_tree_predecessor (cases,
3579                                           (splay_tree_key) low_value);
3580       high_bound = splay_tree_successor (cases,
3581                                          (splay_tree_key) low_value);
3582
3583       /* Check to see if the LOW_BOUND overlaps.  It is smaller than
3584          the LOW_VALUE, so there is no need to check unless the
3585          LOW_BOUND is in fact itself a case range.  */
3586       if (low_bound
3587           && CASE_HIGH ((tree) low_bound->value)
3588           && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
3589                                     low_value) >= 0)
3590         node = low_bound;
3591       /* Check to see if the HIGH_BOUND overlaps.  The low end of that
3592          range is bigger than the low end of the current range, so we
3593          are only interested if the current range is a real range, and
3594          not an ordinary case label.  */
3595       else if (high_bound
3596                && high_value
3597                && (tree_int_cst_compare ((tree) high_bound->key,
3598                                          high_value)
3599                    <= 0))
3600         node = high_bound;
3601     }
3602   /* If there was an overlap, issue an error.  */
3603   if (node)
3604     {
3605       tree duplicate = CASE_LABEL ((tree) node->value);
3606
3607       if (high_value)
3608         {
3609           error ("duplicate (or overlapping) case value");
3610           error ("%Jthis is the first entry overlapping that value", duplicate);
3611         }
3612       else if (low_value)
3613         {
3614           error ("duplicate case value") ;
3615           error ("%Jpreviously used here", duplicate);
3616         }
3617       else
3618         {
3619           error ("multiple default labels in one switch");
3620           error ("%Jthis is the first default label", duplicate);
3621         }
3622       goto error_out;
3623     }
3624
3625   /* Add a CASE_LABEL to the statement-tree.  */
3626   case_label = add_stmt (build_case_label (low_value, high_value, label));
3627   /* Register this case label in the splay tree.  */
3628   splay_tree_insert (cases,
3629                      (splay_tree_key) low_value,
3630                      (splay_tree_value) case_label);
3631
3632   return case_label;
3633
3634  error_out:
3635   /* Add a label so that the back-end doesn't think that the beginning of
3636      the switch is unreachable.  Note that we do not add a case label, as
3637      that just leads to duplicates and thence to aborts later on.  */
3638   if (!cases->root)
3639     {
3640       tree t = create_artificial_label ();
3641       add_stmt (build_stmt (LABEL_EXPR, t));
3642     }
3643   return error_mark_node;
3644 }
3645
3646 /* Subroutines of c_do_switch_warnings, called via splay_tree_foreach.
3647    Used to verify that case values match up with enumerator values.  */
3648
3649 static void
3650 match_case_to_enum_1 (tree key, tree type, tree label)
3651 {
3652   char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1];
3653
3654   /* ??? Not working too hard to print the double-word value.
3655      Should perhaps be done with %lwd in the diagnostic routines?  */
3656   if (TREE_INT_CST_HIGH (key) == 0)
3657     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED,
3658               TREE_INT_CST_LOW (key));
3659   else if (!TYPE_UNSIGNED (type)
3660            && TREE_INT_CST_HIGH (key) == -1
3661            && TREE_INT_CST_LOW (key) != 0)
3662     snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED,
3663               -TREE_INT_CST_LOW (key));
3664   else
3665     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX,
3666               TREE_INT_CST_HIGH (key), TREE_INT_CST_LOW (key));
3667
3668   if (TYPE_NAME (type) == 0)
3669     warning ("%Jcase value %qs not in enumerated type",
3670              CASE_LABEL (label), buf);
3671   else
3672     warning ("%Jcase value %qs not in enumerated type %qT",
3673              CASE_LABEL (label), buf, type);
3674 }
3675
3676 static int
3677 match_case_to_enum (splay_tree_node node, void *data)
3678 {
3679   tree label = (tree) node->value;
3680   tree type = (tree) data;
3681
3682   /* Skip default case.  */
3683   if (!CASE_LOW (label))
3684     return 0;
3685
3686   /* If TREE_ADDRESSABLE is not set, that means CASE_LOW did not appear
3687      when we did our enum->case scan.  Reset our scratch bit after.  */
3688   if (!TREE_ADDRESSABLE (label))
3689     match_case_to_enum_1 (CASE_LOW (label), type, label);
3690   else
3691     TREE_ADDRESSABLE (label) = 0;
3692
3693   /* If CASE_HIGH is non-null, we have a range.  Here we must search.
3694      Note that the old code in stmt.c did not check for the values in
3695      the range either, just the endpoints.  */
3696   if (CASE_HIGH (label))
3697     {
3698       tree chain, key = CASE_HIGH (label);
3699
3700       for (chain = TYPE_VALUES (type);
3701            chain && !tree_int_cst_equal (key, TREE_VALUE (chain));
3702            chain = TREE_CHAIN (chain))
3703         continue;
3704       if (!chain)
3705         match_case_to_enum_1 (key, type, label);
3706     }
3707
3708   return 0;
3709 }
3710
3711 /* Handle -Wswitch*.  Called from the front end after parsing the
3712    switch construct.  */
3713 /* ??? Should probably be somewhere generic, since other languages
3714    besides C and C++ would want this.  At the moment, however, C/C++
3715    are the only tree-ssa languages that support enumerations at all,
3716    so the point is moot.  */
3717
3718 void
3719 c_do_switch_warnings (splay_tree cases, location_t switch_location,
3720                       tree type, tree cond)
3721 {
3722   splay_tree_node default_node;
3723
3724   if (!warn_switch && !warn_switch_enum && !warn_switch_default)
3725     return;
3726
3727   default_node = splay_tree_lookup (cases, (splay_tree_key) NULL);
3728   if (warn_switch_default && !default_node)
3729     warning ("%Hswitch missing default case", &switch_location);
3730
3731   /* If the switch expression was an enumerated type, check that
3732      exactly all enumeration literals are covered by the cases.
3733      The check is made when -Wswitch was specified and there is no
3734      default case, or when -Wswitch-enum was specified.  */
3735   if (((warn_switch && !default_node) || warn_switch_enum)
3736       && type && TREE_CODE (type) == ENUMERAL_TYPE
3737       && TREE_CODE (cond) != INTEGER_CST)
3738     {
3739       tree chain;
3740
3741       /* The time complexity here is O(N*lg(N)) worst case, but for the
3742          common case of monotonically increasing enumerators, it is
3743          O(N), since the nature of the splay tree will keep the next
3744          element adjacent to the root at all times.  */
3745
3746       for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain))
3747         {
3748           splay_tree_node node
3749             = splay_tree_lookup (cases, (splay_tree_key) TREE_VALUE (chain));
3750
3751           if (node)
3752             {
3753               /* Mark the CASE_LOW part of the case entry as seen, so
3754                  that we save time later.  Choose TREE_ADDRESSABLE
3755                  randomly as a bit that won't have been set to-date.  */
3756               tree label = (tree) node->value;
3757               TREE_ADDRESSABLE (label) = 1;
3758             }
3759           else
3760             {
3761               /* Warn if there are enumerators that don't correspond to
3762                  case expressions.  */
3763               warning ("%Henumeration value %qE not handled in switch",
3764                        &switch_location, TREE_PURPOSE (chain));
3765             }
3766         }
3767
3768       /* Warn if there are case expressions that don't correspond to
3769          enumerators.  This can occur since C and C++ don't enforce
3770          type-checking of assignments to enumeration variables.
3771
3772          The time complexity here is O(N**2) worst case, since we've
3773          not sorted the enumeration values.  However, in the absence
3774          of case ranges this is O(N), since all single cases that
3775          corresponded to enumerations have been marked above.  */
3776
3777       splay_tree_foreach (cases, match_case_to_enum, type);
3778     }
3779 }
3780
3781 /* Finish an expression taking the address of LABEL (an
3782    IDENTIFIER_NODE).  Returns an expression for the address.  */
3783
3784 tree
3785 finish_label_address_expr (tree label)
3786 {
3787   tree result;
3788
3789   if (pedantic)
3790     pedwarn ("taking the address of a label is non-standard");
3791
3792   if (label == error_mark_node)
3793     return error_mark_node;
3794
3795   label = lookup_label (label);
3796   if (label == NULL_TREE)
3797     result = null_pointer_node;
3798   else
3799     {
3800       TREE_USED (label) = 1;
3801       result = build1 (ADDR_EXPR, ptr_type_node, label);
3802       /* The current function in not necessarily uninlinable.
3803          Computed gotos are incompatible with inlining, but the value
3804          here could be used only in a diagnostic, for example.  */
3805     }
3806
3807   return result;
3808 }
3809
3810 /* Hook used by expand_expr to expand language-specific tree codes.  */
3811 /* The only things that should go here are bits needed to expand
3812    constant initializers.  Everything else should be handled by the
3813    gimplification routines.  */
3814
3815 rtx
3816 c_expand_expr (tree exp, rtx target, enum machine_mode tmode,
3817                int modifier /* Actually enum_modifier.  */,
3818                rtx *alt_rtl)
3819 {
3820   switch (TREE_CODE (exp))
3821     {
3822     case COMPOUND_LITERAL_EXPR:
3823       {
3824         /* Initialize the anonymous variable declared in the compound
3825            literal, then return the variable.  */
3826         tree decl = COMPOUND_LITERAL_EXPR_DECL (exp);
3827         emit_local_var (decl);
3828         return expand_expr_real (decl, target, tmode, modifier, alt_rtl);
3829       }
3830
3831     default:
3832       gcc_unreachable ();
3833     }
3834 }
3835
3836 /* Hook used by staticp to handle language-specific tree codes.  */
3837
3838 tree
3839 c_staticp (tree exp)
3840 {
3841   return (TREE_CODE (exp) == COMPOUND_LITERAL_EXPR
3842           && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp))
3843           ? exp : NULL);
3844 }
3845 \f
3846
3847 /* Given a boolean expression ARG, return a tree representing an increment
3848    or decrement (as indicated by CODE) of ARG.  The front end must check for
3849    invalid cases (e.g., decrement in C++).  */
3850 tree
3851 boolean_increment (enum tree_code code, tree arg)
3852 {
3853   tree val;
3854   tree true_res = boolean_true_node;
3855
3856   arg = stabilize_reference (arg);
3857   switch (code)
3858     {
3859     case PREINCREMENT_EXPR:
3860       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
3861       break;
3862     case POSTINCREMENT_EXPR:
3863       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
3864       arg = save_expr (arg);
3865       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
3866       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
3867       break;
3868     case PREDECREMENT_EXPR:
3869       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
3870                     invert_truthvalue (arg));
3871       break;
3872     case POSTDECREMENT_EXPR:
3873       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
3874                     invert_truthvalue (arg));
3875       arg = save_expr (arg);
3876       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
3877       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
3878       break;
3879     default:
3880       gcc_unreachable ();
3881     }
3882   TREE_SIDE_EFFECTS (val) = 1;
3883   return val;
3884 }
3885 \f
3886 /* Built-in macros for stddef.h, that require macros defined in this
3887    file.  */
3888 void
3889 c_stddef_cpp_builtins(void)
3890 {
3891   builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0);
3892   builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0);
3893   builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0);
3894   builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0);
3895   builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0);
3896   builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0);
3897 }
3898
3899 static void
3900 c_init_attributes (void)
3901 {
3902   /* Fill in the built_in_attributes array.  */
3903 #define DEF_ATTR_NULL_TREE(ENUM)                                \
3904   built_in_attributes[(int) ENUM] = NULL_TREE;
3905 #define DEF_ATTR_INT(ENUM, VALUE)                               \
3906   built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
3907 #define DEF_ATTR_IDENT(ENUM, STRING)                            \
3908   built_in_attributes[(int) ENUM] = get_identifier (STRING);
3909 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
3910   built_in_attributes[(int) ENUM]                       \
3911     = tree_cons (built_in_attributes[(int) PURPOSE],    \
3912                  built_in_attributes[(int) VALUE],      \
3913                  built_in_attributes[(int) CHAIN]);
3914 #include "builtin-attrs.def"
3915 #undef DEF_ATTR_NULL_TREE
3916 #undef DEF_ATTR_INT
3917 #undef DEF_ATTR_IDENT
3918 #undef DEF_ATTR_TREE_LIST
3919 }
3920
3921 /* Attribute handlers common to C front ends.  */
3922
3923 /* Handle a "packed" attribute; arguments as in
3924    struct attribute_spec.handler.  */
3925
3926 static tree
3927 handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
3928                          int flags, bool *no_add_attrs)
3929 {
3930   if (TYPE_P (*node))
3931     {
3932       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
3933         *node = build_variant_type_copy (*node);
3934       TYPE_PACKED (*node) = 1;
3935       if (TYPE_MAIN_VARIANT (*node) == *node)
3936         {
3937           /* If it is the main variant, then pack the other variants
3938              too. This happens in,
3939
3940              struct Foo {
3941                struct Foo const *ptr; // creates a variant w/o packed flag
3942                } __ attribute__((packed)); // packs it now.
3943           */
3944           tree probe;
3945
3946           for (probe = *node; probe; probe = TYPE_NEXT_VARIANT (probe))
3947             TYPE_PACKED (probe) = 1;
3948         }
3949
3950     }
3951   else if (TREE_CODE (*node) == FIELD_DECL)
3952     DECL_PACKED (*node) = 1;
3953   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
3954      used for DECL_REGISTER.  It wouldn't mean anything anyway.
3955      We can't set DECL_PACKED on the type of a TYPE_DECL, because
3956      that changes what the typedef is typing.  */
3957   else
3958     {
3959       warning ("%qE attribute ignored", name);
3960       *no_add_attrs = true;
3961     }
3962
3963   return NULL_TREE;
3964 }
3965
3966 /* Handle a "nocommon" attribute; arguments as in
3967    struct attribute_spec.handler.  */
3968
3969 static tree
3970 handle_nocommon_attribute (tree *node, tree name,
3971                            tree ARG_UNUSED (args),
3972                            int ARG_UNUSED (flags), bool *no_add_attrs)
3973 {
3974   if (TREE_CODE (*node) == VAR_DECL)
3975     DECL_COMMON (*node) = 0;
3976   else
3977     {
3978       warning ("%qE attribute ignored", name);
3979       *no_add_attrs = true;
3980     }
3981
3982   return NULL_TREE;
3983 }
3984
3985 /* Handle a "common" attribute; arguments as in
3986    struct attribute_spec.handler.  */
3987
3988 static tree
3989 handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args),
3990                          int ARG_UNUSED (flags), bool *no_add_attrs)
3991 {
3992   if (TREE_CODE (*node) == VAR_DECL)
3993     DECL_COMMON (*node) = 1;
3994   else
3995     {
3996       warning ("%qE attribute ignored", name);
3997       *no_add_attrs = true;
3998     }
3999
4000   return NULL_TREE;
4001 }
4002
4003 /* Handle a "noreturn" attribute; arguments as in
4004    struct attribute_spec.handler.  */
4005
4006 static tree
4007 handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4008                            int ARG_UNUSED (flags), bool *no_add_attrs)
4009 {
4010   tree type = TREE_TYPE (*node);
4011
4012   /* See FIXME comment in c_common_attribute_table.  */
4013   if (TREE_CODE (*node) == FUNCTION_DECL)
4014     TREE_THIS_VOLATILE (*node) = 1;
4015   else if (TREE_CODE (type) == POINTER_TYPE
4016            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4017     TREE_TYPE (*node)
4018       = build_pointer_type
4019         (build_type_variant (TREE_TYPE (type),
4020                              TYPE_READONLY (TREE_TYPE (type)), 1));
4021   else
4022     {
4023       warning ("%qE attribute ignored", name);
4024       *no_add_attrs = true;
4025     }
4026
4027   return NULL_TREE;
4028 }
4029
4030 /* Handle a "noinline" attribute; arguments as in
4031    struct attribute_spec.handler.  */
4032
4033 static tree
4034 handle_noinline_attribute (tree *node, tree name,
4035                            tree ARG_UNUSED (args),
4036                            int ARG_UNUSED (flags), bool *no_add_attrs)
4037 {
4038   if (TREE_CODE (*node) == FUNCTION_DECL)
4039     DECL_UNINLINABLE (*node) = 1;
4040   else
4041     {
4042       warning ("%qE attribute ignored", name);
4043       *no_add_attrs = true;
4044     }
4045
4046   return NULL_TREE;
4047 }
4048
4049 /* Handle a "always_inline" attribute; arguments as in
4050    struct attribute_spec.handler.  */
4051
4052 static tree
4053 handle_always_inline_attribute (tree *node, tree name,
4054                                 tree ARG_UNUSED (args),
4055                                 int ARG_UNUSED (flags),
4056                                 bool *no_add_attrs)
4057 {
4058   if (TREE_CODE (*node) == FUNCTION_DECL)
4059     {
4060       /* Do nothing else, just set the attribute.  We'll get at
4061          it later with lookup_attribute.  */
4062     }
4063   else
4064     {
4065       warning ("%qE attribute ignored", name);
4066       *no_add_attrs = true;
4067     }
4068
4069   return NULL_TREE;
4070 }
4071
4072 /* Handle a "used" attribute; arguments as in
4073    struct attribute_spec.handler.  */
4074
4075 static tree
4076 handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
4077                        int ARG_UNUSED (flags), bool *no_add_attrs)
4078 {
4079   tree node = *pnode;
4080
4081   if (TREE_CODE (node) == FUNCTION_DECL
4082       || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node)))
4083     {
4084       TREE_USED (node) = 1;
4085       DECL_PRESERVE_P (node) = 1;
4086     }
4087   else
4088     {
4089       warning ("%qE attribute ignored", name);
4090       *no_add_attrs = true;
4091     }
4092
4093   return NULL_TREE;
4094 }
4095
4096 /* Handle a "unused" attribute; arguments as in
4097    struct attribute_spec.handler.  */
4098
4099 static tree
4100 handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4101                          int flags, bool *no_add_attrs)
4102 {
4103   if (DECL_P (*node))
4104     {
4105       tree decl = *node;
4106
4107       if (TREE_CODE (decl) == PARM_DECL
4108           || TREE_CODE (decl) == VAR_DECL
4109           || TREE_CODE (decl) == FUNCTION_DECL
4110           || TREE_CODE (decl) == LABEL_DECL
4111           || TREE_CODE (decl) == TYPE_DECL)
4112         TREE_USED (decl) = 1;
4113       else
4114         {
4115           warning ("%qE attribute ignored", name);
4116           *no_add_attrs = true;
4117         }
4118     }
4119   else
4120     {
4121       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4122         *node = build_variant_type_copy (*node);
4123       TREE_USED (*node) = 1;
4124     }
4125
4126   return NULL_TREE;
4127 }
4128
4129 /* Handle a "const" attribute; arguments as in
4130    struct attribute_spec.handler.  */
4131
4132 static tree
4133 handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4134                         int ARG_UNUSED (flags), bool *no_add_attrs)
4135 {
4136   tree type = TREE_TYPE (*node);
4137
4138   /* See FIXME comment on noreturn in c_common_attribute_table.  */
4139   if (TREE_CODE (*node) == FUNCTION_DECL)
4140     TREE_READONLY (*node) = 1;
4141   else if (TREE_CODE (type) == POINTER_TYPE
4142            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4143     TREE_TYPE (*node)
4144       = build_pointer_type
4145         (build_type_variant (TREE_TYPE (type), 1,
4146                              TREE_THIS_VOLATILE (TREE_TYPE (type))));
4147   else
4148     {
4149       warning ("%qE attribute ignored", name);
4150       *no_add_attrs = true;
4151     }
4152
4153   return NULL_TREE;
4154 }
4155
4156 /* Handle a "transparent_union" attribute; arguments as in
4157    struct attribute_spec.handler.  */
4158
4159 static tree
4160 handle_transparent_union_attribute (tree *node, tree name,
4161                                     tree ARG_UNUSED (args), int flags,
4162                                     bool *no_add_attrs)
4163 {
4164   tree decl = NULL_TREE;
4165   tree *type = NULL;
4166   int is_type = 0;
4167
4168   if (DECL_P (*node))
4169     {
4170       decl = *node;
4171       type = &TREE_TYPE (decl);
4172       is_type = TREE_CODE (*node) == TYPE_DECL;
4173     }
4174   else if (TYPE_P (*node))
4175     type = node, is_type = 1;
4176
4177   if (is_type
4178       && TREE_CODE (*type) == UNION_TYPE
4179       && (decl == 0
4180           || (TYPE_FIELDS (*type) != 0
4181               && TYPE_MODE (*type) == DECL_MODE (TYPE_FIELDS (*type)))))
4182     {
4183       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4184         *type = build_variant_type_copy (*type);
4185       TYPE_TRANSPARENT_UNION (*type) = 1;
4186     }
4187   else if (decl != 0 && TREE_CODE (decl) == PARM_DECL
4188            && TREE_CODE (*type) == UNION_TYPE
4189            && TYPE_MODE (*type) == DECL_MODE (TYPE_FIELDS (*type)))
4190     DECL_TRANSPARENT_UNION (decl) = 1;
4191   else
4192     {
4193       warning ("%qE attribute ignored", name);
4194       *no_add_attrs = true;
4195     }
4196
4197   return NULL_TREE;
4198 }
4199
4200 /* Handle a "constructor" attribute; arguments as in
4201    struct attribute_spec.handler.  */
4202
4203 static tree
4204 handle_constructor_attribute (tree *node, tree name,
4205                               tree ARG_UNUSED (args),
4206                               int ARG_UNUSED (flags),
4207                               bool *no_add_attrs)
4208 {
4209   tree decl = *node;
4210   tree type = TREE_TYPE (decl);
4211
4212   if (TREE_CODE (decl) == FUNCTION_DECL
4213       && TREE_CODE (type) == FUNCTION_TYPE
4214       && decl_function_context (decl) == 0)
4215     {
4216       DECL_STATIC_CONSTRUCTOR (decl) = 1;
4217       TREE_USED (decl) = 1;
4218     }
4219   else
4220     {
4221       warning ("%qE attribute ignored", name);
4222       *no_add_attrs = true;
4223     }
4224
4225   return NULL_TREE;
4226 }
4227
4228 /* Handle a "destructor" attribute; arguments as in
4229    struct attribute_spec.handler.  */
4230
4231 static tree
4232 handle_destructor_attribute (tree *node, tree name,
4233                              tree ARG_UNUSED (args),
4234                              int ARG_UNUSED (flags),
4235                              bool *no_add_attrs)
4236 {
4237   tree decl = *node;
4238   tree type = TREE_TYPE (decl);
4239
4240   if (TREE_CODE (decl) == FUNCTION_DECL
4241       && TREE_CODE (type) == FUNCTION_TYPE
4242       && decl_function_context (decl) == 0)
4243     {
4244       DECL_STATIC_DESTRUCTOR (decl) = 1;
4245       TREE_USED (decl) = 1;
4246     }
4247   else
4248     {
4249       warning ("%qE attribute ignored", name);
4250       *no_add_attrs = true;
4251     }
4252
4253   return NULL_TREE;
4254 }
4255
4256 /* Handle a "mode" attribute; arguments as in
4257    struct attribute_spec.handler.  */
4258
4259 static tree
4260 handle_mode_attribute (tree *node, tree name, tree args,
4261                        int ARG_UNUSED (flags), bool *no_add_attrs)
4262 {
4263   tree type = *node;
4264
4265   *no_add_attrs = true;
4266
4267   if (TREE_CODE (TREE_VALUE (args)) != IDENTIFIER_NODE)
4268     warning ("%qE attribute ignored", name);
4269   else
4270     {
4271       int j;
4272       const char *p = IDENTIFIER_POINTER (TREE_VALUE (args));
4273       int len = strlen (p);
4274       enum machine_mode mode = VOIDmode;
4275       tree typefm;
4276       bool valid_mode;
4277
4278       if (len > 4 && p[0] == '_' && p[1] == '_'
4279           && p[len - 1] == '_' && p[len - 2] == '_')
4280         {
4281           char *newp = (char *) alloca (len - 1);
4282
4283           strcpy (newp, &p[2]);
4284           newp[len - 4] = '\0';
4285           p = newp;
4286         }
4287
4288       /* Change this type to have a type with the specified mode.
4289          First check for the special modes.  */
4290       if (!strcmp (p, "byte"))
4291         mode = byte_mode;
4292       else if (!strcmp (p, "word"))
4293         mode = word_mode;
4294       else if (!strcmp (p, "pointer"))
4295         mode = ptr_mode;
4296       else
4297         for (j = 0; j < NUM_MACHINE_MODES; j++)
4298           if (!strcmp (p, GET_MODE_NAME (j)))
4299             {
4300               mode = (enum machine_mode) j;
4301               break;
4302             }
4303
4304       if (mode == VOIDmode)
4305         {
4306           error ("unknown machine mode %qs", p);
4307           return NULL_TREE;
4308         }
4309
4310       valid_mode = false;
4311       switch (GET_MODE_CLASS (mode))
4312         {
4313         case MODE_INT:
4314         case MODE_PARTIAL_INT:
4315         case MODE_FLOAT:
4316           valid_mode = targetm.scalar_mode_supported_p (mode);
4317           break;
4318
4319         case MODE_COMPLEX_INT:
4320         case MODE_COMPLEX_FLOAT:
4321           valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode));
4322           break;
4323
4324         case MODE_VECTOR_INT:
4325         case MODE_VECTOR_FLOAT:
4326           warning ("specifying vector types with __attribute__ ((mode)) "
4327                    "is deprecated");
4328           warning ("use __attribute__ ((vector_size)) instead");
4329           valid_mode = vector_mode_valid_p (mode);
4330           break;
4331
4332         default:
4333           break;
4334         }
4335       if (!valid_mode)
4336         {
4337           error ("unable to emulate %qs", p);
4338           return NULL_TREE;
4339         }
4340
4341       if (POINTER_TYPE_P (type))
4342         {
4343           tree (*fn)(tree, enum machine_mode, bool);
4344
4345           if (!targetm.valid_pointer_mode (mode))
4346             {
4347               error ("invalid pointer mode %qs", p);
4348               return NULL_TREE;
4349             }
4350
4351           if (TREE_CODE (type) == POINTER_TYPE)
4352             fn = build_pointer_type_for_mode;
4353           else
4354             fn = build_reference_type_for_mode;
4355           typefm = fn (TREE_TYPE (type), mode, false);
4356         }
4357       else
4358         typefm = lang_hooks.types.type_for_mode (mode, TYPE_UNSIGNED (type));
4359
4360       if (typefm == NULL_TREE)
4361         {
4362           error ("no data type for mode %qs", p);
4363           return NULL_TREE;
4364         }
4365       else if (TREE_CODE (type) == ENUMERAL_TYPE)
4366         {
4367           /* For enumeral types, copy the precision from the integer
4368              type returned above.  If not an INTEGER_TYPE, we can't use
4369              this mode for this type.  */
4370           if (TREE_CODE (typefm) != INTEGER_TYPE)
4371             {
4372               error ("cannot use mode %qs for enumeral types", p);
4373               return NULL_TREE;
4374             }
4375
4376           if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4377             type = build_variant_type_copy (type);
4378
4379           /* We cannot use layout_type here, because that will attempt
4380              to re-layout all variants, corrupting our original.  */
4381           TYPE_PRECISION (type) = TYPE_PRECISION (typefm);
4382           TYPE_MIN_VALUE (type) = TYPE_MIN_VALUE (typefm);
4383           TYPE_MAX_VALUE (type) = TYPE_MAX_VALUE (typefm);
4384           TYPE_SIZE (type) = TYPE_SIZE (typefm);
4385           TYPE_SIZE_UNIT (type) = TYPE_SIZE_UNIT (typefm);
4386           TYPE_MODE (type) = TYPE_MODE (typefm);
4387           if (!TYPE_USER_ALIGN (type))
4388             TYPE_ALIGN (type) = TYPE_ALIGN (typefm);
4389
4390           typefm = type;
4391         }
4392       else if (VECTOR_MODE_P (mode)
4393                ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm))
4394                : TREE_CODE (type) != TREE_CODE (typefm))
4395         {
4396           error ("mode %qs applied to inappropriate type", p);
4397           return NULL_TREE;
4398         }
4399
4400       *node = typefm;
4401     }
4402
4403   return NULL_TREE;
4404 }
4405
4406 /* Handle a "section" attribute; arguments as in
4407    struct attribute_spec.handler.  */
4408
4409 static tree
4410 handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args,
4411                           int ARG_UNUSED (flags), bool *no_add_attrs)
4412 {
4413   tree decl = *node;
4414
4415   if (targetm.have_named_sections)
4416     {
4417       user_defined_section_attribute = true;
4418
4419       if ((TREE_CODE (decl) == FUNCTION_DECL
4420            || TREE_CODE (decl) == VAR_DECL)
4421           && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
4422         {
4423           if (TREE_CODE (decl) == VAR_DECL
4424               && current_function_decl != NULL_TREE
4425               && !TREE_STATIC (decl))
4426             {
4427               error ("%Jsection attribute cannot be specified for "
4428                      "local variables", decl);
4429               *no_add_attrs = true;
4430             }
4431
4432           /* The decl may have already been given a section attribute
4433              from a previous declaration.  Ensure they match.  */
4434           else if (DECL_SECTION_NAME (decl) != NULL_TREE
4435                    && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
4436                               TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
4437             {
4438               error ("%Jsection of %qD conflicts with previous declaration",
4439                      *node, *node);
4440               *no_add_attrs = true;
4441             }
4442           else
4443             DECL_SECTION_NAME (decl) = TREE_VALUE (args);
4444         }
4445       else
4446         {
4447           error ("%Jsection attribute not allowed for %qD", *node, *node);
4448           *no_add_attrs = true;
4449         }
4450     }
4451   else
4452     {
4453       error ("%Jsection attributes are not supported for this target", *node);
4454       *no_add_attrs = true;
4455     }
4456
4457   return NULL_TREE;
4458 }
4459
4460 /* Handle a "aligned" attribute; arguments as in
4461    struct attribute_spec.handler.  */
4462
4463 static tree
4464 handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args,
4465                           int flags, bool *no_add_attrs)
4466 {
4467   tree decl = NULL_TREE;
4468   tree *type = NULL;
4469   int is_type = 0;
4470   tree align_expr = (args ? TREE_VALUE (args)
4471                      : size_int (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
4472   int i;
4473
4474   if (DECL_P (*node))
4475     {
4476       decl = *node;
4477       type = &TREE_TYPE (decl);
4478       is_type = TREE_CODE (*node) == TYPE_DECL;
4479     }
4480   else if (TYPE_P (*node))
4481     type = node, is_type = 1;
4482
4483   if (TREE_CODE (align_expr) != INTEGER_CST)
4484     {
4485       error ("requested alignment is not a constant");
4486       *no_add_attrs = true;
4487     }
4488   else if ((i = tree_log2 (align_expr)) == -1)
4489     {
4490       error ("requested alignment is not a power of 2");
4491       *no_add_attrs = true;
4492     }
4493   else if (i > HOST_BITS_PER_INT - 2)
4494     {
4495       error ("requested alignment is too large");
4496       *no_add_attrs = true;
4497     }
4498   else if (is_type)
4499     {
4500       /* If we have a TYPE_DECL, then copy the type, so that we
4501          don't accidentally modify a builtin type.  See pushdecl.  */
4502       if (decl && TREE_TYPE (decl) != error_mark_node
4503           && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
4504         {
4505           tree tt = TREE_TYPE (decl);
4506           *type = build_variant_type_copy (*type);
4507           DECL_ORIGINAL_TYPE (decl) = tt;
4508           TYPE_NAME (*type) = decl;
4509           TREE_USED (*type) = TREE_USED (decl);
4510           TREE_TYPE (decl) = *type;
4511         }
4512       else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4513         *type = build_variant_type_copy (*type);
4514
4515       TYPE_ALIGN (*type) = (1 << i) * BITS_PER_UNIT;
4516       TYPE_USER_ALIGN (*type) = 1;
4517     }
4518   else if (TREE_CODE (decl) != VAR_DECL
4519            && TREE_CODE (decl) != FIELD_DECL)
4520     {
4521       error ("%Jalignment may not be specified for %qD", decl, decl);
4522       *no_add_attrs = true;
4523     }
4524   else
4525     {
4526       DECL_ALIGN (decl) = (1 << i) * BITS_PER_UNIT;
4527       DECL_USER_ALIGN (decl) = 1;
4528     }
4529
4530   return NULL_TREE;
4531 }
4532
4533 /* Handle a "weak" attribute; arguments as in
4534    struct attribute_spec.handler.  */
4535
4536 static tree
4537 handle_weak_attribute (tree *node, tree ARG_UNUSED (name),
4538                        tree ARG_UNUSED (args),
4539                        int ARG_UNUSED (flags),
4540                        bool * ARG_UNUSED (no_add_attrs))
4541 {
4542   declare_weak (*node);
4543
4544   return NULL_TREE;
4545 }
4546
4547 /* Handle an "alias" attribute; arguments as in
4548    struct attribute_spec.handler.  */
4549
4550 static tree
4551 handle_alias_attribute (tree *node, tree name, tree args,
4552                         int ARG_UNUSED (flags), bool *no_add_attrs)
4553 {
4554   tree decl = *node;
4555
4556   if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
4557       || (TREE_CODE (decl) != FUNCTION_DECL && !DECL_EXTERNAL (decl)))
4558     {
4559       error ("%J%qD defined both normally and as an alias", decl, decl);
4560       *no_add_attrs = true;
4561     }
4562
4563   /* Note that the very first time we process a nested declaration,
4564      decl_function_context will not be set.  Indeed, *would* never
4565      be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that
4566      we do below.  After such frobbery, pushdecl would set the context.
4567      In any case, this is never what we want.  */
4568   else if (decl_function_context (decl) == 0 && current_function_decl == NULL)
4569     {
4570       tree id;
4571
4572       id = TREE_VALUE (args);
4573       if (TREE_CODE (id) != STRING_CST)
4574         {
4575           error ("alias argument not a string");
4576           *no_add_attrs = true;
4577           return NULL_TREE;
4578         }
4579       id = get_identifier (TREE_STRING_POINTER (id));
4580       /* This counts as a use of the object pointed to.  */
4581       TREE_USED (id) = 1;
4582
4583       if (TREE_CODE (decl) == FUNCTION_DECL)
4584         DECL_INITIAL (decl) = error_mark_node;
4585       else
4586         {
4587           DECL_EXTERNAL (decl) = 0;
4588           TREE_STATIC (decl) = 1;
4589         }
4590     }
4591   else
4592     {
4593       warning ("%qE attribute ignored", name);
4594       *no_add_attrs = true;
4595     }
4596
4597   return NULL_TREE;
4598 }
4599
4600 /* Handle an "visibility" attribute; arguments as in
4601    struct attribute_spec.handler.  */
4602
4603 static tree
4604 handle_visibility_attribute (tree *node, tree name, tree args,
4605                              int ARG_UNUSED (flags),
4606                              bool *no_add_attrs)
4607 {
4608   tree decl = *node;
4609   tree id = TREE_VALUE (args);
4610
4611   *no_add_attrs = true;
4612
4613   if (TYPE_P (*node))
4614     {
4615       if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE)
4616        {
4617          warning ("%qE attribute ignored on non-class types", name);
4618          return NULL_TREE;
4619        }
4620     }
4621   else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl))
4622     {
4623       warning ("%qE attribute ignored", name);
4624       return NULL_TREE;
4625     }
4626
4627   if (TREE_CODE (id) != STRING_CST)
4628     {
4629       error ("visibility argument not a string");
4630       return NULL_TREE;
4631     }
4632
4633   /*  If this is a type, set the visibility on the type decl.  */
4634   if (TYPE_P (decl))
4635     {
4636       decl = TYPE_NAME (decl);
4637       if (!decl)
4638         return NULL_TREE;
4639       if (TREE_CODE (decl) == IDENTIFIER_NODE)
4640         {
4641            warning ("%qE attribute ignored on types",
4642                     name);
4643            return NULL_TREE;
4644         }
4645     }
4646
4647   if (strcmp (TREE_STRING_POINTER (id), "default") == 0)
4648     DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
4649   else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0)
4650     DECL_VISIBILITY (decl) = VISIBILITY_INTERNAL;
4651   else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0)
4652     DECL_VISIBILITY (decl) = VISIBILITY_HIDDEN;
4653   else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0)
4654     DECL_VISIBILITY (decl) = VISIBILITY_PROTECTED;
4655   else
4656     error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\"");
4657   DECL_VISIBILITY_SPECIFIED (decl) = 1;
4658
4659   /* For decls only, go ahead and attach the attribute to the node as well.
4660      This is needed so we can determine whether we have VISIBILITY_DEFAULT
4661      because the visibility was not specified, or because it was explicitly
4662      overridden from the class visibility.  */
4663   if (DECL_P (*node))
4664     *no_add_attrs = false;
4665
4666   return NULL_TREE;
4667 }
4668
4669 /* Determine the ELF symbol visibility for DECL, which is either a
4670    variable or a function.  It is an error to use this function if a
4671    definition of DECL is not available in this translation unit.
4672    Returns true if the final visibility has been determined by this
4673    function; false if the caller is free to make additional
4674    modifications.  */
4675
4676 bool
4677 c_determine_visibility (tree decl)
4678 {
4679   gcc_assert (TREE_CODE (decl) == VAR_DECL
4680               || TREE_CODE (decl) == FUNCTION_DECL);
4681
4682   /* If the user explicitly specified the visibility with an
4683      attribute, honor that.  DECL_VISIBILITY will have been set during
4684      the processing of the attribute.  We check for an explicit
4685      attribute, rather than just checking DECL_VISIBILITY_SPECIFIED,
4686      to distinguish the use of an attribute from the use of a "#pragma
4687      GCC visibility push(...)"; in the latter case we still want other
4688      considerations to be able to overrule the #pragma.  */
4689   if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl)))
4690     return true;
4691
4692   /* Anything that is exported must have default visibility.  */
4693   if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
4694       && lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))
4695     {
4696       DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
4697       DECL_VISIBILITY_SPECIFIED (decl) = 1;
4698       return true;
4699     }
4700
4701   return false;
4702 }
4703
4704 /* Handle an "tls_model" attribute; arguments as in
4705    struct attribute_spec.handler.  */
4706
4707 static tree
4708 handle_tls_model_attribute (tree *node, tree name, tree args,
4709                             int ARG_UNUSED (flags), bool *no_add_attrs)
4710 {
4711   tree decl = *node;
4712
4713   if (!DECL_THREAD_LOCAL (decl))
4714     {
4715       warning ("%qE attribute ignored", name);
4716       *no_add_attrs = true;
4717     }
4718   else
4719     {
4720       tree id;
4721
4722       id = TREE_VALUE (args);
4723       if (TREE_CODE (id) != STRING_CST)
4724         {
4725           error ("tls_model argument not a string");
4726           *no_add_attrs = true;
4727           return NULL_TREE;
4728         }
4729       if (strcmp (TREE_STRING_POINTER (id), "local-exec")
4730           && strcmp (TREE_STRING_POINTER (id), "initial-exec")
4731           && strcmp (TREE_STRING_POINTER (id), "local-dynamic")
4732           && strcmp (TREE_STRING_POINTER (id), "global-dynamic"))
4733         {
4734           error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\"");
4735           *no_add_attrs = true;
4736           return NULL_TREE;
4737         }
4738     }
4739
4740   return NULL_TREE;
4741 }
4742
4743 /* Handle a "no_instrument_function" attribute; arguments as in
4744    struct attribute_spec.handler.  */
4745
4746 static tree
4747 handle_no_instrument_function_attribute (tree *node, tree name,
4748                                          tree ARG_UNUSED (args),
4749                                          int ARG_UNUSED (flags),
4750                                          bool *no_add_attrs)
4751 {
4752   tree decl = *node;
4753
4754   if (TREE_CODE (decl) != FUNCTION_DECL)
4755     {
4756       error ("%J%qE attribute applies only to functions", decl, name);
4757       *no_add_attrs = true;
4758     }
4759   else if (DECL_INITIAL (decl))
4760     {
4761       error ("%Jcan%'t set %qE attribute after definition", decl, name);
4762       *no_add_attrs = true;
4763     }
4764   else
4765     DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
4766
4767   return NULL_TREE;
4768 }
4769
4770 /* Handle a "malloc" attribute; arguments as in
4771    struct attribute_spec.handler.  */
4772
4773 static tree
4774 handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4775                          int ARG_UNUSED (flags), bool *no_add_attrs)
4776 {
4777   if (TREE_CODE (*node) == FUNCTION_DECL
4778       && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node))))
4779     DECL_IS_MALLOC (*node) = 1;
4780   else
4781     {
4782       warning ("%qE attribute ignored", name);
4783       *no_add_attrs = true;
4784     }
4785
4786   return NULL_TREE;
4787 }
4788
4789 /* Handle a "returns_twice" attribute; arguments as in
4790    struct attribute_spec.handler.  */
4791
4792 static tree
4793 handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4794                          int ARG_UNUSED (flags), bool *no_add_attrs)
4795 {
4796   if (TREE_CODE (*node) == FUNCTION_DECL)
4797     DECL_IS_RETURNS_TWICE (*node) = 1;
4798   else
4799     {
4800       warning ("%qE attribute ignored", name);
4801       *no_add_attrs = true;
4802     }
4803
4804   return NULL_TREE;
4805 }
4806
4807 /* Handle a "no_limit_stack" attribute; arguments as in
4808    struct attribute_spec.handler.  */
4809
4810 static tree
4811 handle_no_limit_stack_attribute (tree *node, tree name,
4812                                  tree ARG_UNUSED (args),
4813                                  int ARG_UNUSED (flags),
4814                                  bool *no_add_attrs)
4815 {
4816   tree decl = *node;
4817
4818   if (TREE_CODE (decl) != FUNCTION_DECL)
4819     {
4820       error ("%J%qE attribute applies only to functions", decl, name);
4821       *no_add_attrs = true;
4822     }
4823   else if (DECL_INITIAL (decl))
4824     {
4825       error ("%Jcan%'t set %qE attribute after definition", decl, name);
4826       *no_add_attrs = true;
4827     }
4828   else
4829     DECL_NO_LIMIT_STACK (decl) = 1;
4830
4831   return NULL_TREE;
4832 }
4833
4834 /* Handle a "pure" attribute; arguments as in
4835    struct attribute_spec.handler.  */
4836
4837 static tree
4838 handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4839                        int ARG_UNUSED (flags), bool *no_add_attrs)
4840 {
4841   if (TREE_CODE (*node) == FUNCTION_DECL)
4842     DECL_IS_PURE (*node) = 1;
4843   /* ??? TODO: Support types.  */
4844   else
4845     {
4846       warning ("%qE attribute ignored", name);
4847       *no_add_attrs = true;
4848     }
4849
4850   return NULL_TREE;
4851 }
4852
4853 /* Handle a "no vops" attribute; arguments as in
4854    struct attribute_spec.handler.  */
4855
4856 static tree
4857 handle_novops_attribute (tree *node, tree ARG_UNUSED (name),
4858                          tree ARG_UNUSED (args), int ARG_UNUSED (flags),
4859                          bool *ARG_UNUSED (no_add_attrs))
4860 {
4861   gcc_assert (TREE_CODE (*node) == FUNCTION_DECL);
4862   DECL_IS_NOVOPS (*node) = 1;
4863   return NULL_TREE;
4864 }
4865
4866 /* Handle a "deprecated" attribute; arguments as in
4867    struct attribute_spec.handler.  */
4868
4869 static tree
4870 handle_deprecated_attribute (tree *node, tree name,
4871                              tree ARG_UNUSED (args), int flags,
4872                              bool *no_add_attrs)
4873 {
4874   tree type = NULL_TREE;
4875   int warn = 0;
4876   tree what = NULL_TREE;
4877
4878   if (DECL_P (*node))
4879     {
4880       tree decl = *node;
4881       type = TREE_TYPE (decl);
4882
4883       if (TREE_CODE (decl) == TYPE_DECL
4884           || TREE_CODE (decl) == PARM_DECL
4885           || TREE_CODE (decl) == VAR_DECL
4886           || TREE_CODE (decl) == FUNCTION_DECL
4887           || TREE_CODE (decl) == FIELD_DECL)
4888         TREE_DEPRECATED (decl) = 1;
4889       else
4890         warn = 1;
4891     }
4892   else if (TYPE_P (*node))
4893     {
4894       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4895         *node = build_variant_type_copy (*node);
4896       TREE_DEPRECATED (*node) = 1;
4897       type = *node;
4898     }
4899   else
4900     warn = 1;
4901
4902   if (warn)
4903     {
4904       *no_add_attrs = true;
4905       if (type && TYPE_NAME (type))
4906         {
4907           if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
4908             what = TYPE_NAME (*node);
4909           else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
4910                    && DECL_NAME (TYPE_NAME (type)))
4911             what = DECL_NAME (TYPE_NAME (type));
4912         }
4913       if (what)
4914         warning ("%qE attribute ignored for %qE", name, what);
4915       else
4916         warning ("%qE attribute ignored", name);
4917     }
4918
4919   return NULL_TREE;
4920 }
4921
4922 /* Handle a "vector_size" attribute; arguments as in
4923    struct attribute_spec.handler.  */
4924
4925 static tree
4926 handle_vector_size_attribute (tree *node, tree name, tree args,
4927                               int ARG_UNUSED (flags),
4928                               bool *no_add_attrs)
4929 {
4930   unsigned HOST_WIDE_INT vecsize, nunits;
4931   enum machine_mode orig_mode;
4932   tree type = *node, new_type, size;
4933
4934   *no_add_attrs = true;
4935
4936   size = TREE_VALUE (args);
4937
4938   if (!host_integerp (size, 1))
4939     {
4940       warning ("%qE attribute ignored", name);
4941       return NULL_TREE;
4942     }
4943
4944   /* Get the vector size (in bytes).  */
4945   vecsize = tree_low_cst (size, 1);
4946
4947   /* We need to provide for vector pointers, vector arrays, and
4948      functions returning vectors.  For example:
4949
4950        __attribute__((vector_size(16))) short *foo;
4951
4952      In this case, the mode is SI, but the type being modified is
4953      HI, so we need to look further.  */
4954
4955   while (POINTER_TYPE_P (type)
4956          || TREE_CODE (type) == FUNCTION_TYPE
4957          || TREE_CODE (type) == METHOD_TYPE
4958          || TREE_CODE (type) == ARRAY_TYPE)
4959     type = TREE_TYPE (type);
4960
4961   /* Get the mode of the type being modified.  */
4962   orig_mode = TYPE_MODE (type);
4963
4964   if (TREE_CODE (type) == RECORD_TYPE
4965       || (GET_MODE_CLASS (orig_mode) != MODE_FLOAT
4966           && GET_MODE_CLASS (orig_mode) != MODE_INT)
4967       || !host_integerp (TYPE_SIZE_UNIT (type), 1))
4968     {
4969       error ("invalid vector type for attribute %qE", name);
4970       return NULL_TREE;
4971     }
4972
4973   /* Calculate how many units fit in the vector.  */
4974   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
4975   if (nunits & (nunits - 1))
4976     {
4977       error ("number of components of the vector not a power of two");
4978       return NULL_TREE;
4979     }
4980
4981   new_type = build_vector_type (type, nunits);
4982
4983   /* Build back pointers if needed.  */
4984   *node = reconstruct_complex_type (*node, new_type);
4985
4986   return NULL_TREE;
4987 }
4988
4989 /* Handle the "nonnull" attribute.  */
4990 static tree
4991 handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
4992                           tree args, int ARG_UNUSED (flags),
4993                           bool *no_add_attrs)
4994 {
4995   tree type = *node;
4996   unsigned HOST_WIDE_INT attr_arg_num;
4997
4998   /* If no arguments are specified, all pointer arguments should be
4999      non-null.  Verify a full prototype is given so that the arguments
5000      will have the correct types when we actually check them later.  */
5001   if (!args)
5002     {
5003       if (!TYPE_ARG_TYPES (type))
5004         {
5005           error ("nonnull attribute without arguments on a non-prototype");
5006           *no_add_attrs = true;
5007         }
5008       return NULL_TREE;
5009     }
5010
5011   /* Argument list specified.  Verify that each argument number references
5012      a pointer argument.  */
5013   for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
5014     {
5015       tree argument;
5016       unsigned HOST_WIDE_INT arg_num = 0, ck_num;
5017
5018       if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
5019         {
5020           error ("nonnull argument has invalid operand number (argument %lu)",
5021                  (unsigned long) attr_arg_num);
5022           *no_add_attrs = true;
5023           return NULL_TREE;
5024         }
5025
5026       argument = TYPE_ARG_TYPES (type);
5027       if (argument)
5028         {
5029           for (ck_num = 1; ; ck_num++)
5030             {
5031               if (!argument || ck_num == arg_num)
5032                 break;
5033               argument = TREE_CHAIN (argument);
5034             }
5035
5036           if (!argument
5037               || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
5038             {
5039               error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)",
5040                      (unsigned long) attr_arg_num, (unsigned long) arg_num);
5041               *no_add_attrs = true;
5042               return NULL_TREE;
5043             }
5044
5045           if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
5046             {
5047               error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)",
5048                    (unsigned long) attr_arg_num, (unsigned long) arg_num);
5049               *no_add_attrs = true;
5050               return NULL_TREE;
5051             }
5052         }
5053     }
5054
5055   return NULL_TREE;
5056 }
5057
5058 /* Check the argument list of a function call for null in argument slots
5059    that are marked as requiring a non-null pointer argument.  */
5060
5061 static void
5062 check_function_nonnull (tree attrs, tree params)
5063 {
5064   tree a, args, param;
5065   int param_num;
5066
5067   for (a = attrs; a; a = TREE_CHAIN (a))
5068     {
5069       if (is_attribute_p ("nonnull", TREE_PURPOSE (a)))
5070         {
5071           args = TREE_VALUE (a);
5072
5073           /* Walk the argument list.  If we encounter an argument number we
5074              should check for non-null, do it.  If the attribute has no args,
5075              then every pointer argument is checked (in which case the check
5076              for pointer type is done in check_nonnull_arg).  */
5077           for (param = params, param_num = 1; ;
5078                param_num++, param = TREE_CHAIN (param))
5079             {
5080               if (!param)
5081         break;
5082               if (!args || nonnull_check_p (args, param_num))
5083         check_function_arguments_recurse (check_nonnull_arg, NULL,
5084                                           TREE_VALUE (param),
5085                                           param_num);
5086             }
5087         }
5088     }
5089 }
5090
5091 /* Check that the Nth argument of a function call (counting backwards
5092    from the end) is a (pointer)0.  */
5093
5094 static void
5095 check_function_sentinel (tree attrs, tree params)
5096 {
5097   tree attr = lookup_attribute ("sentinel", attrs);
5098
5099   if (attr)
5100     {
5101       if (!params)
5102         warning ("missing sentinel in function call");
5103       else
5104         {
5105           tree sentinel, end;
5106           unsigned pos = 0;
5107
5108           if (TREE_VALUE (attr))
5109             {
5110               tree p = TREE_VALUE (TREE_VALUE (attr));
5111               pos = TREE_INT_CST_LOW (p);
5112             }
5113
5114           sentinel = end = params;
5115
5116           /* Advance `end' ahead of `sentinel' by `pos' positions.  */
5117           while (pos > 0 && TREE_CHAIN (end))
5118             {
5119               pos--;
5120               end = TREE_CHAIN (end);
5121             }
5122           if (pos > 0)
5123             {
5124               warning ("not enough arguments to fit a sentinel");
5125               return;
5126             }
5127
5128           /* Now advance both until we find the last parameter.  */
5129           while (TREE_CHAIN (end))
5130             {
5131               end = TREE_CHAIN (end);
5132               sentinel = TREE_CHAIN (sentinel);
5133             }
5134
5135           /* Validate the sentinel.  */
5136           if (!POINTER_TYPE_P (TREE_TYPE (TREE_VALUE (sentinel)))
5137               || !integer_zerop (TREE_VALUE (sentinel)))
5138             warning ("missing sentinel in function call");
5139         }
5140     }
5141 }
5142
5143 /* Helper for check_function_nonnull; given a list of operands which
5144    must be non-null in ARGS, determine if operand PARAM_NUM should be
5145    checked.  */
5146
5147 static bool
5148 nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num)
5149 {
5150   unsigned HOST_WIDE_INT arg_num = 0;
5151
5152   for (; args; args = TREE_CHAIN (args))
5153     {
5154       bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num);
5155
5156       gcc_assert (found);
5157
5158       if (arg_num == param_num)
5159         return true;
5160     }
5161   return false;
5162 }
5163
5164 /* Check that the function argument PARAM (which is operand number
5165    PARAM_NUM) is non-null.  This is called by check_function_nonnull
5166    via check_function_arguments_recurse.  */
5167
5168 static void
5169 check_nonnull_arg (void * ARG_UNUSED (ctx), tree param,
5170                    unsigned HOST_WIDE_INT param_num)
5171 {
5172   /* Just skip checking the argument if it's not a pointer.  This can
5173      happen if the "nonnull" attribute was given without an operand
5174      list (which means to check every pointer argument).  */
5175
5176   if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE)
5177     return;
5178
5179   if (integer_zerop (param))
5180     warning ("null argument where non-null required (argument %lu)",
5181              (unsigned long) param_num);
5182 }
5183
5184 /* Helper for nonnull attribute handling; fetch the operand number
5185    from the attribute argument list.  */
5186
5187 static bool
5188 get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp)
5189 {
5190   /* Verify the arg number is a constant.  */
5191   if (TREE_CODE (arg_num_expr) != INTEGER_CST
5192       || TREE_INT_CST_HIGH (arg_num_expr) != 0)
5193     return false;
5194
5195   *valp = TREE_INT_CST_LOW (arg_num_expr);
5196   return true;
5197 }
5198
5199 /* Handle a "nothrow" attribute; arguments as in
5200    struct attribute_spec.handler.  */
5201
5202 static tree
5203 handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5204                           int ARG_UNUSED (flags), bool *no_add_attrs)
5205 {
5206   if (TREE_CODE (*node) == FUNCTION_DECL)
5207     TREE_NOTHROW (*node) = 1;
5208   /* ??? TODO: Support types.  */
5209   else
5210     {
5211       warning ("%qE attribute ignored", name);
5212       *no_add_attrs = true;
5213     }
5214
5215   return NULL_TREE;
5216 }
5217
5218 /* Handle a "cleanup" attribute; arguments as in
5219    struct attribute_spec.handler.  */
5220
5221 static tree
5222 handle_cleanup_attribute (tree *node, tree name, tree args,
5223                           int ARG_UNUSED (flags), bool *no_add_attrs)
5224 {
5225   tree decl = *node;
5226   tree cleanup_id, cleanup_decl;
5227
5228   /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do
5229      for global destructors in C++.  This requires infrastructure that
5230      we don't have generically at the moment.  It's also not a feature
5231      we'd be missing too much, since we do have attribute constructor.  */
5232   if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl))
5233     {
5234       warning ("%qE attribute ignored", name);
5235       *no_add_attrs = true;
5236       return NULL_TREE;
5237     }
5238
5239   /* Verify that the argument is a function in scope.  */
5240   /* ??? We could support pointers to functions here as well, if
5241      that was considered desirable.  */
5242   cleanup_id = TREE_VALUE (args);
5243   if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE)
5244     {
5245       error ("cleanup argument not an identifier");
5246       *no_add_attrs = true;
5247       return NULL_TREE;
5248     }
5249   cleanup_decl = lookup_name (cleanup_id);
5250   if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL)
5251     {
5252       error ("cleanup argument not a function");
5253       *no_add_attrs = true;
5254       return NULL_TREE;
5255     }
5256
5257   /* That the function has proper type is checked with the
5258      eventual call to build_function_call.  */
5259
5260   return NULL_TREE;
5261 }
5262
5263 /* Handle a "warn_unused_result" attribute.  No special handling.  */
5264
5265 static tree
5266 handle_warn_unused_result_attribute (tree *node, tree name,
5267                                tree ARG_UNUSED (args),
5268                                int ARG_UNUSED (flags), bool *no_add_attrs)
5269 {
5270   /* Ignore the attribute for functions not returning any value.  */
5271   if (VOID_TYPE_P (TREE_TYPE (*node)))
5272     {
5273       warning ("%qE attribute ignored", name);
5274       *no_add_attrs = true;
5275     }
5276
5277   return NULL_TREE;
5278 }
5279
5280 /* Handle a "sentinel" attribute.  */
5281
5282 static tree
5283 handle_sentinel_attribute (tree *node, tree name, tree args,
5284                            int ARG_UNUSED (flags), bool *no_add_attrs)
5285 {
5286   tree params = TYPE_ARG_TYPES (*node);
5287
5288   if (!params)
5289     {
5290       warning ("%qE attribute requires prototypes with named arguments", name);
5291       *no_add_attrs = true;
5292     }
5293   else
5294     {
5295       while (TREE_CHAIN (params))
5296         params = TREE_CHAIN (params);
5297
5298       if (VOID_TYPE_P (TREE_VALUE (params)))
5299         {
5300           warning ("%qE attribute only applies to variadic functions", name);
5301           *no_add_attrs = true;
5302         }
5303     }
5304
5305   if (args)
5306     {
5307       tree position = TREE_VALUE (args);
5308
5309       if (TREE_CODE (position) != INTEGER_CST)
5310         {
5311           warning ("requested position is not an integer constant");
5312           *no_add_attrs = true;
5313         }
5314       else
5315         {
5316           if (tree_int_cst_lt (position, integer_zero_node))
5317             {
5318               warning ("requested position is less than zero");
5319               *no_add_attrs = true;
5320             }
5321         }
5322     }
5323
5324   return NULL_TREE;
5325 }
5326 \f
5327 /* Check for valid arguments being passed to a function.  */
5328 void
5329 check_function_arguments (tree attrs, tree params)
5330 {
5331   /* Check for null being passed in a pointer argument that must be
5332      non-null.  We also need to do this if format checking is enabled.  */
5333
5334   if (warn_nonnull)
5335     check_function_nonnull (attrs, params);
5336
5337   /* Check for errors in format strings.  */
5338
5339   if (warn_format)
5340     {
5341       check_function_format (attrs, params);
5342       check_function_sentinel (attrs, params);
5343     }
5344 }
5345
5346 /* Generic argument checking recursion routine.  PARAM is the argument to
5347    be checked.  PARAM_NUM is the number of the argument.  CALLBACK is invoked
5348    once the argument is resolved.  CTX is context for the callback.  */
5349 void
5350 check_function_arguments_recurse (void (*callback)
5351                                   (void *, tree, unsigned HOST_WIDE_INT),
5352                                   void *ctx, tree param,
5353                                   unsigned HOST_WIDE_INT param_num)
5354 {
5355   if (TREE_CODE (param) == NOP_EXPR)
5356     {
5357       /* Strip coercion.  */
5358       check_function_arguments_recurse (callback, ctx,
5359                                         TREE_OPERAND (param, 0), param_num);
5360       return;
5361     }
5362
5363   if (TREE_CODE (param) == CALL_EXPR)
5364     {
5365       tree type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (param, 0)));
5366       tree attrs;
5367       bool found_format_arg = false;
5368
5369       /* See if this is a call to a known internationalization function
5370          that modifies a format arg.  Such a function may have multiple
5371          format_arg attributes (for example, ngettext).  */
5372
5373       for (attrs = TYPE_ATTRIBUTES (type);
5374            attrs;
5375            attrs = TREE_CHAIN (attrs))
5376         if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs)))
5377           {
5378             tree inner_args;
5379             tree format_num_expr;
5380             int format_num;
5381             int i;
5382
5383             /* Extract the argument number, which was previously checked
5384                to be valid.  */
5385             format_num_expr = TREE_VALUE (TREE_VALUE (attrs));
5386
5387             gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST
5388                         && !TREE_INT_CST_HIGH (format_num_expr));
5389
5390             format_num = TREE_INT_CST_LOW (format_num_expr);
5391
5392             for (inner_args = TREE_OPERAND (param, 1), i = 1;
5393                  inner_args != 0;
5394                  inner_args = TREE_CHAIN (inner_args), i++)
5395               if (i == format_num)
5396                 {
5397                   check_function_arguments_recurse (callback, ctx,
5398                                                     TREE_VALUE (inner_args),
5399                                                     param_num);
5400                   found_format_arg = true;
5401                   break;
5402                 }
5403           }
5404
5405       /* If we found a format_arg attribute and did a recursive check,
5406          we are done with checking this argument.  Otherwise, we continue
5407          and this will be considered a non-literal.  */
5408       if (found_format_arg)
5409         return;
5410     }
5411
5412   if (TREE_CODE (param) == COND_EXPR)
5413     {
5414       /* Check both halves of the conditional expression.  */
5415       check_function_arguments_recurse (callback, ctx,
5416                                         TREE_OPERAND (param, 1), param_num);
5417       check_function_arguments_recurse (callback, ctx,
5418                                         TREE_OPERAND (param, 2), param_num);
5419       return;
5420     }
5421
5422   (*callback) (ctx, param, param_num);
5423 }
5424
5425 /* Function to help qsort sort FIELD_DECLs by name order.  */
5426
5427 int
5428 field_decl_cmp (const void *x_p, const void *y_p)
5429 {
5430   const tree *const x = (const tree *const) x_p;
5431   const tree *const y = (const tree *const) y_p;
5432
5433   if (DECL_NAME (*x) == DECL_NAME (*y))
5434     /* A nontype is "greater" than a type.  */
5435     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
5436   if (DECL_NAME (*x) == NULL_TREE)
5437     return -1;
5438   if (DECL_NAME (*y) == NULL_TREE)
5439     return 1;
5440   if (DECL_NAME (*x) < DECL_NAME (*y))
5441     return -1;
5442   return 1;
5443 }
5444
5445 static struct {
5446   gt_pointer_operator new_value;
5447   void *cookie;
5448 } resort_data;
5449
5450 /* This routine compares two fields like field_decl_cmp but using the
5451 pointer operator in resort_data.  */
5452
5453 static int
5454 resort_field_decl_cmp (const void *x_p, const void *y_p)
5455 {
5456   const tree *const x = (const tree *const) x_p;
5457   const tree *const y = (const tree *const) y_p;
5458
5459   if (DECL_NAME (*x) == DECL_NAME (*y))
5460     /* A nontype is "greater" than a type.  */
5461     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
5462   if (DECL_NAME (*x) == NULL_TREE)
5463     return -1;
5464   if (DECL_NAME (*y) == NULL_TREE)
5465     return 1;
5466   {
5467     tree d1 = DECL_NAME (*x);
5468     tree d2 = DECL_NAME (*y);
5469     resort_data.new_value (&d1, resort_data.cookie);
5470     resort_data.new_value (&d2, resort_data.cookie);
5471     if (d1 < d2)
5472       return -1;
5473   }
5474   return 1;
5475 }
5476
5477 /* Resort DECL_SORTED_FIELDS because pointers have been reordered.  */
5478
5479 void
5480 resort_sorted_fields (void *obj,
5481                       void * ARG_UNUSED (orig_obj),
5482                       gt_pointer_operator new_value,
5483                       void *cookie)
5484 {
5485   struct sorted_fields_type *sf = (struct sorted_fields_type *) obj;
5486   resort_data.new_value = new_value;
5487   resort_data.cookie = cookie;
5488   qsort (&sf->elts[0], sf->len, sizeof (tree),
5489          resort_field_decl_cmp);
5490 }
5491
5492 /* Subroutine of c_parse_error.
5493    Return the result of concatenating LHS and RHS. RHS is really
5494    a string literal, its first character is indicated by RHS_START and
5495    RHS_SIZE is its length (including the terminating NUL character).
5496
5497    The caller is responsible for deleting the returned pointer.  */
5498
5499 static char *
5500 catenate_strings (const char *lhs, const char *rhs_start, int rhs_size)
5501 {
5502   const int lhs_size = strlen (lhs);
5503   char *result = XNEWVEC (char, lhs_size + rhs_size);
5504   strncpy (result, lhs, lhs_size);
5505   strncpy (result + lhs_size, rhs_start, rhs_size);
5506   return result;
5507 }
5508
5509 /* Issue the error given by MSGID, indicating that it occurred before
5510    TOKEN, which had the associated VALUE.  */
5511
5512 void
5513 c_parse_error (const char *msgid, enum cpp_ttype token, tree value)
5514 {
5515 #define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2))
5516
5517   char *message = NULL;
5518
5519   if (token == CPP_EOF)
5520     message = catenate_messages (msgid, " at end of input");
5521   else if (token == CPP_CHAR || token == CPP_WCHAR)
5522     {
5523       unsigned int val = TREE_INT_CST_LOW (value);
5524       const char *const ell = (token == CPP_CHAR) ? "" : "L";
5525       if (val <= UCHAR_MAX && ISGRAPH (val))
5526         message = catenate_messages (msgid, " before %s'%c'");
5527       else
5528         message = catenate_messages (msgid, " before %s'\\x%x'");
5529
5530       error (message, ell, val);
5531       free (message);
5532       message = NULL;
5533     }
5534   else if (token == CPP_STRING || token == CPP_WSTRING)
5535     message = catenate_messages (msgid, " before string constant");
5536   else if (token == CPP_NUMBER)
5537     message = catenate_messages (msgid, " before numeric constant");
5538   else if (token == CPP_NAME)
5539     {
5540       message = catenate_messages (msgid, " before %qE");
5541       error (message, value);
5542       free (message);
5543       message = NULL;
5544     }
5545   else if (token < N_TTYPES)
5546     {
5547       message = catenate_messages (msgid, " before %qs token");
5548       error (message, cpp_type2name (token));
5549       free (message);
5550       message = NULL;
5551     }
5552   else
5553     error (msgid);
5554
5555   if (message)
5556     {
5557       error (message);
5558       free (message);
5559     }
5560 #undef catenate_messages
5561 }
5562
5563 /* Walk a gimplified function and warn for functions whose return value is
5564    ignored and attribute((warn_unused_result)) is set.  This is done before
5565    inlining, so we don't have to worry about that.  */
5566
5567 void
5568 c_warn_unused_result (tree *top_p)
5569 {
5570   tree t = *top_p;
5571   tree_stmt_iterator i;
5572   tree fdecl, ftype;
5573
5574   switch (TREE_CODE (t))
5575     {
5576     case STATEMENT_LIST:
5577       for (i = tsi_start (*top_p); !tsi_end_p (i); tsi_next (&i))
5578         c_warn_unused_result (tsi_stmt_ptr (i));
5579       break;
5580
5581     case COND_EXPR:
5582       c_warn_unused_result (&COND_EXPR_THEN (t));
5583       c_warn_unused_result (&COND_EXPR_ELSE (t));
5584       break;
5585     case BIND_EXPR:
5586       c_warn_unused_result (&BIND_EXPR_BODY (t));
5587       break;
5588     case TRY_FINALLY_EXPR:
5589     case TRY_CATCH_EXPR:
5590       c_warn_unused_result (&TREE_OPERAND (t, 0));
5591       c_warn_unused_result (&TREE_OPERAND (t, 1));
5592       break;
5593     case CATCH_EXPR:
5594       c_warn_unused_result (&CATCH_BODY (t));
5595       break;
5596     case EH_FILTER_EXPR:
5597       c_warn_unused_result (&EH_FILTER_FAILURE (t));
5598       break;
5599
5600     case CALL_EXPR:
5601       if (TREE_USED (t))
5602         break;
5603
5604       /* This is a naked call, as opposed to a CALL_EXPR nested inside
5605          a MODIFY_EXPR.  All calls whose value is ignored should be
5606          represented like this.  Look for the attribute.  */
5607       fdecl = get_callee_fndecl (t);
5608       if (fdecl)
5609         ftype = TREE_TYPE (fdecl);
5610       else
5611         {
5612           ftype = TREE_TYPE (TREE_OPERAND (t, 0));
5613           /* Look past pointer-to-function to the function type itself.  */
5614           ftype = TREE_TYPE (ftype);
5615         }
5616
5617       if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype)))
5618         {
5619           if (fdecl)
5620             warning ("%Hignoring return value of %qD, "
5621                      "declared with attribute warn_unused_result",
5622                      EXPR_LOCUS (t), fdecl);
5623           else
5624             warning ("%Hignoring return value of function "
5625                      "declared with attribute warn_unused_result",
5626                      EXPR_LOCUS (t));
5627         }
5628       break;
5629
5630     default:
5631       /* Not a container, not a call, or a call whose value is used.  */
5632       break;
5633     }
5634 }
5635
5636 /* Convert a character from the host to the target execution character
5637    set.  cpplib handles this, mostly.  */
5638
5639 HOST_WIDE_INT
5640 c_common_to_target_charset (HOST_WIDE_INT c)
5641 {
5642   /* Character constants in GCC proper are sign-extended under -fsigned-char,
5643      zero-extended under -fno-signed-char.  cpplib insists that characters
5644      and character constants are always unsigned.  Hence we must convert
5645      back and forth.  */
5646   cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1);
5647
5648   uc = cpp_host_to_exec_charset (parse_in, uc);
5649
5650   if (flag_signed_char)
5651     return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE)
5652                                >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE);
5653   else
5654     return uc;
5655 }
5656
5657 /* Build the result of __builtin_offsetof.  EXPR is a nested sequence of
5658    component references, with an INDIRECT_REF at the bottom; much like
5659    the traditional rendering of offsetof as a macro.  Returns the folded
5660    and properly cast result.  */
5661
5662 static tree
5663 fold_offsetof_1 (tree expr)
5664 {
5665   enum tree_code code = PLUS_EXPR;
5666   tree base, off, t;
5667
5668   switch (TREE_CODE (expr))
5669     {
5670     case ERROR_MARK:
5671       return expr;
5672
5673     case INDIRECT_REF:
5674       return size_zero_node;
5675
5676     case COMPONENT_REF:
5677       base = fold_offsetof_1 (TREE_OPERAND (expr, 0));
5678       if (base == error_mark_node)
5679         return base;
5680
5681       t = TREE_OPERAND (expr, 1);
5682       if (DECL_C_BIT_FIELD (t))
5683         {
5684           error ("attempt to take address of bit-field structure "
5685                  "member %qD", t);
5686           return error_mark_node;
5687         }
5688       off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t),
5689                         size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t), 1)
5690                                   / BITS_PER_UNIT));
5691       break;
5692
5693     case ARRAY_REF:
5694       base = fold_offsetof_1 (TREE_OPERAND (expr, 0));
5695       if (base == error_mark_node)
5696         return base;
5697
5698       t = TREE_OPERAND (expr, 1);
5699       if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0)
5700         {
5701           code = MINUS_EXPR;
5702           t = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
5703         }
5704       t = convert (sizetype, t);
5705       off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
5706       break;
5707
5708     default:
5709       gcc_unreachable ();
5710     }
5711
5712   return size_binop (code, base, off);
5713 }
5714
5715 tree
5716 fold_offsetof (tree expr)
5717 {
5718   /* Convert back from the internal sizetype to size_t.  */
5719   return convert (size_type_node, fold_offsetof_1 (expr));
5720 }
5721
5722 /* Print an error message for an invalid lvalue.  USE says
5723    how the lvalue is being used and so selects the error message.  */
5724
5725 void
5726 lvalue_error (enum lvalue_use use)
5727 {
5728   switch (use)
5729     {
5730     case lv_assign:
5731       error ("invalid lvalue in assignment");
5732       break;
5733     case lv_increment:
5734       error ("invalid lvalue in increment");
5735       break;
5736     case lv_decrement:
5737       error ("invalid lvalue in decrement");
5738       break;
5739     case lv_addressof:
5740       error ("invalid lvalue in unary %<&%>");
5741       break;
5742     case lv_asm:
5743       error ("invalid lvalue in asm statement");
5744       break;
5745     default:
5746       gcc_unreachable ();
5747     }
5748 }
5749 \f
5750 /* *PTYPE is an incomplete array.  Complete it with a domain based on
5751    INITIAL_VALUE.  If INITIAL_VALUE is not present, use 1 if DO_DEFAULT
5752    is true.  Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered,
5753    2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty.  */
5754
5755 int
5756 complete_array_type (tree *ptype, tree initial_value, bool do_default)
5757 {
5758   tree maxindex, type, main_type, elt, unqual_elt;
5759   int failure = 0, quals;
5760
5761   maxindex = size_zero_node;
5762   if (initial_value)
5763     {
5764       if (TREE_CODE (initial_value) == STRING_CST)
5765         {
5766           int eltsize
5767             = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value)));
5768           maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1);
5769         }
5770       else if (TREE_CODE (initial_value) == CONSTRUCTOR)
5771         {
5772           tree elts = CONSTRUCTOR_ELTS (initial_value);
5773
5774           if (elts == NULL)
5775             {
5776               if (pedantic)
5777                 failure = 3;
5778               maxindex = integer_minus_one_node;
5779             }
5780           else
5781             {
5782               tree curindex;
5783
5784               if (TREE_PURPOSE (elts))
5785                 maxindex = fold_convert (sizetype, TREE_PURPOSE (elts));
5786               curindex = maxindex;
5787
5788               for (elts = TREE_CHAIN (elts); elts; elts = TREE_CHAIN (elts))
5789                 {
5790                   if (TREE_PURPOSE (elts))
5791                     curindex = fold_convert (sizetype, TREE_PURPOSE (elts));
5792                   else
5793                     curindex = size_binop (PLUS_EXPR, curindex, size_one_node);
5794
5795                   if (tree_int_cst_lt (maxindex, curindex))
5796                     maxindex = curindex;
5797                 }
5798             }
5799         }
5800       else
5801         {
5802           /* Make an error message unless that happened already.  */
5803           if (initial_value != error_mark_node)
5804             failure = 1;
5805         }
5806     }
5807   else
5808     {
5809       failure = 2;
5810       if (!do_default)
5811         return failure;
5812     }
5813
5814   type = *ptype;
5815   elt = TREE_TYPE (type);
5816   quals = TYPE_QUALS (strip_array_types (elt));
5817   if (quals == 0)
5818     unqual_elt = elt;
5819   else
5820     unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
5821
5822   /* Using build_distinct_type_copy and modifying things afterward instead
5823      of using build_array_type to create a new type preserves all of the
5824      TYPE_LANG_FLAG_? bits that the front end may have set.  */
5825   main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
5826   TREE_TYPE (main_type) = unqual_elt;
5827   TYPE_DOMAIN (main_type) = build_index_type (maxindex);
5828   layout_type (main_type);
5829
5830   if (quals == 0)
5831     type = main_type;
5832   else
5833     type = c_build_qualified_type (main_type, quals);
5834
5835   *ptype = type;
5836   return failure;
5837 }
5838
5839 #include "gt-c-common.h"