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, 2006, 2007 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 3, 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 COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "tm.h"
  25 #include "intl.h"
  26 #include "tree.h"
  27 #include "flags.h"
  28 #include "output.h"
  29 #include "c-pragma.h"
  30 #include "rtl.h"
  31 #include "ggc.h"
  32 #include "varray.h"
  33 #include "expr.h"
  34 #include "c-common.h"
  35 #include "diagnostic.h"
  36 #include "tm_p.h"
  37 #include "obstack.h"
  38 #include "cpplib.h"
  39 #include "target.h"
  40 #include "langhooks.h"
  41 #include "tree-inline.h"
  42 #include "c-tree.h"
  43 #include "toplev.h"
  44 #include "tree-iterator.h"
  45 #include "hashtab.h"
  46 #include "tree-mudflap.h"
  47 #include "opts.h"
  48 #include "real.h"
  49 #include "cgraph.h"
  50 #include "target-def.h"
  51 #include "fixed-value.h"
  52
  53 cpp_reader *parse_in;           /* Declared in c-pragma.h.  */
  54
  55 /* We let tm.h override the types used here, to handle trivial differences
  56    such as the choice of unsigned int or long unsigned int for size_t.
  57    When machines start needing nontrivial differences in the size type,
  58    it would be best to do something here to figure out automatically
  59    from other information what type to use.  */
  60
  61 #ifndef SIZE_TYPE
  62 #define SIZE_TYPE "long unsigned int"
  63 #endif
  64
  65 #ifndef PID_TYPE
  66 #define PID_TYPE "int"
  67 #endif
  68
  69 #ifndef WCHAR_TYPE
  70 #define WCHAR_TYPE "int"
  71 #endif
  72
  73 /* WCHAR_TYPE gets overridden by -fshort-wchar.  */
  74 #define MODIFIED_WCHAR_TYPE \
  75         (flag_short_wchar ? "short unsigned int" : WCHAR_TYPE)
  76
  77 #ifndef PTRDIFF_TYPE
  78 #define PTRDIFF_TYPE "long int"
  79 #endif
  80
  81 #ifndef WINT_TYPE
  82 #define WINT_TYPE "unsigned int"
  83 #endif
  84
  85 #ifndef INTMAX_TYPE
  86 #define INTMAX_TYPE ((INT_TYPE_SIZE == LONG_LONG_TYPE_SIZE)     \
  87                      ? "int"                                    \
  88                      : ((LONG_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \
  89                         ? "long int"                            \
  90                         : "long long int"))
  91 #endif
  92
  93 #ifndef UINTMAX_TYPE
  94 #define UINTMAX_TYPE ((INT_TYPE_SIZE == LONG_LONG_TYPE_SIZE)    \
  95                      ? "unsigned int"                           \
  96                      : ((LONG_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \
  97                         ? "long unsigned int"                   \
  98                         : "long long unsigned int"))
  99 #endif
 100
 101 /* The following symbols are subsumed in the c_global_trees array, and
 102    listed here individually for documentation purposes.
 103
 104    INTEGER_TYPE and REAL_TYPE nodes for the standard data types.
 105
 106         tree short_integer_type_node;
 107         tree long_integer_type_node;
 108         tree long_long_integer_type_node;
 109
 110         tree short_unsigned_type_node;
 111         tree long_unsigned_type_node;
 112         tree long_long_unsigned_type_node;
 113
 114         tree truthvalue_type_node;
 115         tree truthvalue_false_node;
 116         tree truthvalue_true_node;
 117
 118         tree ptrdiff_type_node;
 119
 120         tree unsigned_char_type_node;
 121         tree signed_char_type_node;
 122         tree wchar_type_node;
 123         tree signed_wchar_type_node;
 124         tree unsigned_wchar_type_node;
 125
 126         tree float_type_node;
 127         tree double_type_node;
 128         tree long_double_type_node;
 129
 130         tree complex_integer_type_node;
 131         tree complex_float_type_node;
 132         tree complex_double_type_node;
 133         tree complex_long_double_type_node;
 134
 135         tree dfloat32_type_node;
 136         tree dfloat64_type_node;
 137         tree_dfloat128_type_node;
 138
 139         tree intQI_type_node;
 140         tree intHI_type_node;
 141         tree intSI_type_node;
 142         tree intDI_type_node;
 143         tree intTI_type_node;
 144
 145         tree unsigned_intQI_type_node;
 146         tree unsigned_intHI_type_node;
 147         tree unsigned_intSI_type_node;
 148         tree unsigned_intDI_type_node;
 149         tree unsigned_intTI_type_node;
 150
 151         tree widest_integer_literal_type_node;
 152         tree widest_unsigned_literal_type_node;
 153
 154    Nodes for types `void *' and `const void *'.
 155
 156         tree ptr_type_node, const_ptr_type_node;
 157
 158    Nodes for types `char *' and `const char *'.
 159
 160         tree string_type_node, const_string_type_node;
 161
 162    Type `char[SOMENUMBER]'.
 163    Used when an array of char is needed and the size is irrelevant.
 164
 165         tree char_array_type_node;
 166
 167    Type `int[SOMENUMBER]' or something like it.
 168    Used when an array of int needed and the size is irrelevant.
 169
 170         tree int_array_type_node;
 171
 172    Type `wchar_t[SOMENUMBER]' or something like it.
 173    Used when a wide string literal is created.
 174
 175         tree wchar_array_type_node;
 176
 177    Type `int ()' -- used for implicit declaration of functions.
 178
 179         tree default_function_type;
 180
 181    A VOID_TYPE node, packaged in a TREE_LIST.
 182
 183         tree void_list_node;
 184
 185   The lazily created VAR_DECLs for __FUNCTION__, __PRETTY_FUNCTION__,
 186   and __func__. (C doesn't generate __FUNCTION__ and__PRETTY_FUNCTION__
 187   VAR_DECLS, but C++ does.)
 188
 189         tree function_name_decl_node;
 190         tree pretty_function_name_decl_node;
 191         tree c99_function_name_decl_node;
 192
 193   Stack of nested function name VAR_DECLs.
 194
 195         tree saved_function_name_decls;
 196
 197 */
 198
 199 tree c_global_trees[CTI_MAX];
 200 \f
 201 /* Switches common to the C front ends.  */
 202
 203 /* Nonzero if prepreprocessing only.  */
 204
 205 int flag_preprocess_only;
 206
 207 /* Nonzero means don't output line number information.  */
 208
 209 char flag_no_line_commands;
 210
 211 /* Nonzero causes -E output not to be done, but directives such as
 212    #define that have side effects are still obeyed.  */
 213
 214 char flag_no_output;
 215
 216 /* Nonzero means dump macros in some fashion.  */
 217
 218 char flag_dump_macros;
 219
 220 /* Nonzero means pass #include lines through to the output.  */
 221
 222 char flag_dump_includes;
 223
 224 /* Nonzero means process PCH files while preprocessing.  */
 225
 226 bool flag_pch_preprocess;
 227
 228 /* The file name to which we should write a precompiled header, or
 229    NULL if no header will be written in this compile.  */
 230
 231 const char *pch_file;
 232
 233 /* Nonzero if an ISO standard was selected.  It rejects macros in the
 234    user's namespace.  */
 235 int flag_iso;
 236
 237 /* Nonzero if -undef was given.  It suppresses target built-in macros
 238    and assertions.  */
 239 int flag_undef;
 240
 241 /* Nonzero means don't recognize the non-ANSI builtin functions.  */
 242
 243 int flag_no_builtin;
 244
 245 /* Nonzero means don't recognize the non-ANSI builtin functions.
 246    -ansi sets this.  */
 247
 248 int flag_no_nonansi_builtin;
 249
 250 /* Nonzero means give `double' the same size as `float'.  */
 251
 252 int flag_short_double;
 253
 254 /* Nonzero means give `wchar_t' the same size as `short'.  */
 255
 256 int flag_short_wchar;
 257
 258 /* Nonzero means allow implicit conversions between vectors with
 259    differing numbers of subparts and/or differing element types.  */
 260 int flag_lax_vector_conversions;
 261
 262 /* Nonzero means allow Microsoft extensions without warnings or errors.  */
 263 int flag_ms_extensions;
 264
 265 /* Nonzero means don't recognize the keyword `asm'.  */
 266
 267 int flag_no_asm;
 268
 269 /* Nonzero means to treat bitfields as signed unless they say `unsigned'.  */
 270
 271 int flag_signed_bitfields = 1;
 272
 273 /* Warn about #pragma directives that are not recognized.  */
 274
 275 int warn_unknown_pragmas; /* Tri state variable.  */
 276
 277 /* Warn about format/argument anomalies in calls to formatted I/O functions
 278    (*printf, *scanf, strftime, strfmon, etc.).  */
 279
 280 int warn_format;
 281
 282 /* Warn about using __null (as NULL in C++) as sentinel.  For code compiled
 283    with GCC this doesn't matter as __null is guaranteed to have the right
 284    size.  */
 285
 286 int warn_strict_null_sentinel;
 287
 288 /* Zero means that faster, ...NonNil variants of objc_msgSend...
 289    calls will be used in ObjC; passing nil receivers to such calls
 290    will most likely result in crashes.  */
 291 int flag_nil_receivers = 1;
 292
 293 /* Nonzero means that code generation will be altered to support
 294    "zero-link" execution.  This currently affects ObjC only, but may
 295    affect other languages in the future.  */
 296 int flag_zero_link = 0;
 297
 298 /* Nonzero means emit an '__OBJC, __image_info' for the current translation
 299    unit.  It will inform the ObjC runtime that class definition(s) herein
 300    contained are to replace one(s) previously loaded.  */
 301 int flag_replace_objc_classes = 0;
 302
 303 /* C/ObjC language option variables.  */
 304
 305
 306 /* Nonzero means allow type mismatches in conditional expressions;
 307    just make their values `void'.  */
 308
 309 int flag_cond_mismatch;
 310
 311 /* Nonzero means enable C89 Amendment 1 features.  */
 312
 313 int flag_isoc94;
 314
 315 /* Nonzero means use the ISO C99 dialect of C.  */
 316
 317 int flag_isoc99;
 318
 319 /* Nonzero means that we have builtin functions, and main is an int.  */
 320
 321 int flag_hosted = 1;
 322
 323 /* Warn if main is suspicious.  */
 324
 325 int warn_main;
 326
 327
 328 /* ObjC language option variables.  */
 329
 330
 331 /* Open and close the file for outputting class declarations, if
 332    requested (ObjC).  */
 333
 334 int flag_gen_declaration;
 335
 336 /* Tells the compiler that this is a special run.  Do not perform any
 337    compiling, instead we are to test some platform dependent features
 338    and output a C header file with appropriate definitions.  */
 339
 340 int print_struct_values;
 341
 342 /* Tells the compiler what is the constant string class for Objc.  */
 343
 344 const char *constant_string_class_name;
 345
 346
 347 /* C++ language option variables.  */
 348
 349
 350 /* Nonzero means don't recognize any extension keywords.  */
 351
 352 int flag_no_gnu_keywords;
 353
 354 /* Nonzero means do emit exported implementations of functions even if
 355    they can be inlined.  */
 356
 357 int flag_implement_inlines = 1;
 358
 359 /* Nonzero means that implicit instantiations will be emitted if needed.  */
 360
 361 int flag_implicit_templates = 1;
 362
 363 /* Nonzero means that implicit instantiations of inline templates will be
 364    emitted if needed, even if instantiations of non-inline templates
 365    aren't.  */
 366
 367 int flag_implicit_inline_templates = 1;
 368
 369 /* Nonzero means generate separate instantiation control files and
 370    juggle them at link time.  */
 371
 372 int flag_use_repository;
 373
 374 /* Nonzero if we want to issue diagnostics that the standard says are not
 375    required.  */
 376
 377 int flag_optional_diags = 1;
 378
 379 /* Nonzero means we should attempt to elide constructors when possible.  */
 380
 381 int flag_elide_constructors = 1;
 382
 383 /* Nonzero means that member functions defined in class scope are
 384    inline by default.  */
 385
 386 int flag_default_inline = 1;
 387
 388 /* Controls whether compiler generates 'type descriptor' that give
 389    run-time type information.  */
 390
 391 int flag_rtti = 1;
 392
 393 /* Nonzero if we want to conserve space in the .o files.  We do this
 394    by putting uninitialized data and runtime initialized data into
 395    .common instead of .data at the expense of not flagging multiple
 396    definitions.  */
 397
 398 int flag_conserve_space;
 399
 400 /* Nonzero if we want to obey access control semantics.  */
 401
 402 int flag_access_control = 1;
 403
 404 /* Nonzero if we want to check the return value of new and avoid calling
 405    constructors if it is a null pointer.  */
 406
 407 int flag_check_new;
 408
 409 /* The C++ dialect being used. C++98 is the default.  */
 410
 411 enum cxx_dialect cxx_dialect = cxx98;
 412
 413 /* Nonzero if we want the new ISO rules for pushing a new scope for `for'
 414    initialization variables.
 415    0: Old rules, set by -fno-for-scope.
 416    2: New ISO rules, set by -ffor-scope.
 417    1: Try to implement new ISO rules, but with backup compatibility
 418    (and warnings).  This is the default, for now.  */
 419
 420 int flag_new_for_scope = 1;
 421
 422 /* Nonzero if we want to emit defined symbols with common-like linkage as
 423    weak symbols where possible, in order to conform to C++ semantics.
 424    Otherwise, emit them as local symbols.  */
 425
 426 int flag_weak = 1;
 427
 428 /* 0 means we want the preprocessor to not emit line directives for
 429    the current working directory.  1 means we want it to do it.  -1
 430    means we should decide depending on whether debugging information
 431    is being emitted or not.  */
 432
 433 int flag_working_directory = -1;
 434
 435 /* Nonzero to use __cxa_atexit, rather than atexit, to register
 436    destructors for local statics and global objects.  '2' means it has been
 437    set nonzero as a default, not by a command-line flag.  */
 438
 439 int flag_use_cxa_atexit = DEFAULT_USE_CXA_ATEXIT;
 440
 441 /* Nonzero to use __cxa_get_exception_ptr in C++ exception-handling
 442    code.  '2' means it has not been set explicitly on the command line.  */
 443
 444 int flag_use_cxa_get_exception_ptr = 2;
 445
 446 /* Nonzero means make the default pedwarns warnings instead of errors.
 447    The value of this flag is ignored if -pedantic is specified.  */
 448
 449 int flag_permissive;
 450
 451 /* Nonzero means to implement standard semantics for exception
 452    specifications, calling unexpected if an exception is thrown that
 453    doesn't match the specification.  Zero means to treat them as
 454    assertions and optimize accordingly, but not check them.  */
 455
 456 int flag_enforce_eh_specs = 1;
 457
 458 /* Nonzero means to generate thread-safe code for initializing local
 459    statics.  */
 460
 461 int flag_threadsafe_statics = 1;
 462
 463 /* Nonzero means warn about implicit declarations.  */
 464
 465 int warn_implicit = 1;
 466
 467 /* Maximum template instantiation depth.  This limit is rather
 468    arbitrary, but it exists to limit the time it takes to notice
 469    infinite template instantiations.  */
 470
 471 int max_tinst_depth = 500;
 472
 473
 474
 475 /* The elements of `ridpointers' are identifier nodes for the reserved
 476    type names and storage classes.  It is indexed by a RID_... value.  */
 477 tree *ridpointers;
 478
 479 tree (*make_fname_decl) (tree, int);
 480
 481 /* Nonzero means the expression being parsed will never be evaluated.
 482    This is a count, since unevaluated expressions can nest.  */
 483 int skip_evaluation;
 484
 485 /* Information about how a function name is generated.  */
 486 struct fname_var_t
 487 {
 488   tree *const decl;     /* pointer to the VAR_DECL.  */
 489   const unsigned rid;   /* RID number for the identifier.  */
 490   const int pretty;     /* How pretty is it? */
 491 };
 492
 493 /* The three ways of getting then name of the current function.  */
 494
 495 const struct fname_var_t fname_vars[] =
 496 {
 497   /* C99 compliant __func__, must be first.  */
 498   {&c99_function_name_decl_node, RID_C99_FUNCTION_NAME, 0},
 499   /* GCC __FUNCTION__ compliant.  */
 500   {&function_name_decl_node, RID_FUNCTION_NAME, 0},
 501   /* GCC __PRETTY_FUNCTION__ compliant.  */
 502   {&pretty_function_name_decl_node, RID_PRETTY_FUNCTION_NAME, 1},
 503   {NULL, 0, 0},
 504 };
 505
 506 static tree check_case_value (tree);
 507 static bool check_case_bounds (tree, tree, tree *, tree *);
 508
 509 static tree handle_packed_attribute (tree *, tree, tree, int, bool *);
 510 static tree handle_nocommon_attribute (tree *, tree, tree, int, bool *);
 511 static tree handle_common_attribute (tree *, tree, tree, int, bool *);
 512 static tree handle_noreturn_attribute (tree *, tree, tree, int, bool *);
 513 static tree handle_hot_attribute (tree *, tree, tree, int, bool *);
 514 static tree handle_cold_attribute (tree *, tree, tree, int, bool *);
 515 static tree handle_noinline_attribute (tree *, tree, tree, int, bool *);
 516 static tree handle_always_inline_attribute (tree *, tree, tree, int,
 517                                             bool *);
 518 static tree handle_gnu_inline_attribute (tree *, tree, tree, int, bool *);
 519 static tree handle_artificial_attribute (tree *, tree, tree, int, bool *);
 520 static tree handle_flatten_attribute (tree *, tree, tree, int, bool *);
 521 static tree handle_error_attribute (tree *, tree, tree, int, bool *);
 522 static tree handle_used_attribute (tree *, tree, tree, int, bool *);
 523 static tree handle_unused_attribute (tree *, tree, tree, int, bool *);
 524 static tree handle_externally_visible_attribute (tree *, tree, tree, int,
 525                                                  bool *);
 526 static tree handle_const_attribute (tree *, tree, tree, int, bool *);
 527 static tree handle_transparent_union_attribute (tree *, tree, tree,
 528                                                 int, bool *);
 529 static tree handle_constructor_attribute (tree *, tree, tree, int, bool *);
 530 static tree handle_destructor_attribute (tree *, tree, tree, int, bool *);
 531 static tree handle_mode_attribute (tree *, tree, tree, int, bool *);
 532 static tree handle_section_attribute (tree *, tree, tree, int, bool *);
 533 static tree handle_aligned_attribute (tree *, tree, tree, int, bool *);
 534 static tree handle_weak_attribute (tree *, tree, tree, int, bool *) ;
 535 static tree handle_alias_attribute (tree *, tree, tree, int, bool *);
 536 static tree handle_weakref_attribute (tree *, tree, tree, int, bool *) ;
 537 static tree handle_visibility_attribute (tree *, tree, tree, int,
 538                                          bool *);
 539 static tree handle_tls_model_attribute (tree *, tree, tree, int,
 540                                         bool *);
 541 static tree handle_no_instrument_function_attribute (tree *, tree,
 542                                                      tree, int, bool *);
 543 static tree handle_malloc_attribute (tree *, tree, tree, int, bool *);
 544 static tree handle_returns_twice_attribute (tree *, tree, tree, int, bool *);
 545 static tree handle_no_limit_stack_attribute (tree *, tree, tree, int,
 546                                              bool *);
 547 static tree handle_pure_attribute (tree *, tree, tree, int, bool *);
 548 static tree handle_novops_attribute (tree *, tree, tree, int, bool *);
 549 static tree handle_deprecated_attribute (tree *, tree, tree, int,
 550                                          bool *);
 551 static tree handle_vector_size_attribute (tree *, tree, tree, int,
 552                                           bool *);
 553 static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *);
 554 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
 555 static tree handle_cleanup_attribute (tree *, tree, tree, int, bool *);
 556 static tree handle_warn_unused_result_attribute (tree *, tree, tree, int,
 557                                                  bool *);
 558 static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *);
 559 static tree handle_type_generic_attribute (tree *, tree, tree, int, bool *);
 560 static tree handle_alloc_size_attribute (tree *, tree, tree, int, bool *);
 561
 562 static void check_function_nonnull (tree, int, tree *);
 563 static void check_nonnull_arg (void *, tree, unsigned HOST_WIDE_INT);
 564 static bool nonnull_check_p (tree, unsigned HOST_WIDE_INT);
 565 static bool get_nonnull_operand (tree, unsigned HOST_WIDE_INT *);
 566 static int resort_field_decl_cmp (const void *, const void *);
 567
 568 /* Table of machine-independent attributes common to all C-like languages.  */
 569 const struct attribute_spec c_common_attribute_table[] =
 570 {
 571   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 572   { "packed",                 0, 0, false, false, false,
 573                               handle_packed_attribute },
 574   { "nocommon",               0, 0, true,  false, false,
 575                               handle_nocommon_attribute },
 576   { "common",                 0, 0, true,  false, false,
 577                               handle_common_attribute },
 578   /* FIXME: logically, noreturn attributes should be listed as
 579      "false, true, true" and apply to function types.  But implementing this
 580      would require all the places in the compiler that use TREE_THIS_VOLATILE
 581      on a decl to identify non-returning functions to be located and fixed
 582      to check the function type instead.  */
 583   { "noreturn",               0, 0, true,  false, false,
 584                               handle_noreturn_attribute },
 585   { "volatile",               0, 0, true,  false, false,
 586                               handle_noreturn_attribute },
 587   { "noinline",               0, 0, true,  false, false,
 588                               handle_noinline_attribute },
 589   { "always_inline",          0, 0, true,  false, false,
 590                               handle_always_inline_attribute },
 591   { "gnu_inline",             0, 0, true,  false, false,
 592                               handle_gnu_inline_attribute },
 593   { "artificial",             0, 0, true,  false, false,
 594                               handle_artificial_attribute },
 595   { "flatten",                0, 0, true,  false, false,
 596                               handle_flatten_attribute },
 597   { "used",                   0, 0, true,  false, false,
 598                               handle_used_attribute },
 599   { "unused",                 0, 0, false, false, false,
 600                               handle_unused_attribute },
 601   { "externally_visible",     0, 0, true,  false, false,
 602                               handle_externally_visible_attribute },
 603   /* The same comments as for noreturn attributes apply to const ones.  */
 604   { "const",                  0, 0, true,  false, false,
 605                               handle_const_attribute },
 606   { "transparent_union",      0, 0, false, false, false,
 607                               handle_transparent_union_attribute },
 608   { "constructor",            0, 1, true,  false, false,
 609                               handle_constructor_attribute },
 610   { "destructor",             0, 1, true,  false, false,
 611                               handle_destructor_attribute },
 612   { "mode",                   1, 1, false,  true, false,
 613                               handle_mode_attribute },
 614   { "section",                1, 1, true,  false, false,
 615                               handle_section_attribute },
 616   { "aligned",                0, 1, false, false, false,
 617                               handle_aligned_attribute },
 618   { "weak",                   0, 0, true,  false, false,
 619                               handle_weak_attribute },
 620   { "alias",                  1, 1, true,  false, false,
 621                               handle_alias_attribute },
 622   { "weakref",                0, 1, true,  false, false,
 623                               handle_weakref_attribute },
 624   { "no_instrument_function", 0, 0, true,  false, false,
 625                               handle_no_instrument_function_attribute },
 626   { "malloc",                 0, 0, true,  false, false,
 627                               handle_malloc_attribute },
 628   { "returns_twice",          0, 0, true,  false, false,
 629                               handle_returns_twice_attribute },
 630   { "no_stack_limit",         0, 0, true,  false, false,
 631                               handle_no_limit_stack_attribute },
 632   { "pure",                   0, 0, true,  false, false,
 633                               handle_pure_attribute },
 634   /* For internal use (marking of builtins) only.  The name contains space
 635      to prevent its usage in source code.  */
 636   { "no vops",                0, 0, true,  false, false,
 637                               handle_novops_attribute },
 638   { "deprecated",             0, 0, false, false, false,
 639                               handle_deprecated_attribute },
 640   { "vector_size",            1, 1, false, true, false,
 641                               handle_vector_size_attribute },
 642   { "visibility",             1, 1, false, false, false,
 643                               handle_visibility_attribute },
 644   { "tls_model",              1, 1, true,  false, false,
 645                               handle_tls_model_attribute },
 646   { "nonnull",                0, -1, false, true, true,
 647                               handle_nonnull_attribute },
 648   { "nothrow",                0, 0, true,  false, false,
 649                               handle_nothrow_attribute },
 650   { "may_alias",              0, 0, false, true, false, NULL },
 651   { "cleanup",                1, 1, true, false, false,
 652                               handle_cleanup_attribute },
 653   { "warn_unused_result",     0, 0, false, true, true,
 654                               handle_warn_unused_result_attribute },
 655   { "sentinel",               0, 1, false, true, true,
 656                               handle_sentinel_attribute },
 657   /* For internal use (marking of builtins) only.  The name contains space
 658      to prevent its usage in source code.  */
 659   { "type generic",           0, 0, false, true, true,
 660                               handle_type_generic_attribute },
 661   { "alloc_size",             1, 2, false, true, true,
 662                               handle_alloc_size_attribute },
 663   { "cold",                   0, 0, true,  false, false,
 664                               handle_cold_attribute },
 665   { "hot",                    0, 0, true,  false, false,
 666                               handle_hot_attribute },
 667   { "warning",                1, 1, true,  false, false,
 668                               handle_error_attribute },
 669   { "error",                  1, 1, true,  false, false,
 670                               handle_error_attribute },
 671   { NULL,                     0, 0, false, false, false, NULL }
 672 };
 673
 674 /* Give the specifications for the format attributes, used by C and all
 675    descendants.  */
 676
 677 const struct attribute_spec c_common_format_attribute_table[] =
 678 {
 679   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 680   { "format",                 3, 3, false, true,  true,
 681                               handle_format_attribute },
 682   { "format_arg",             1, 1, false, true,  true,
 683                               handle_format_arg_attribute },
 684   { NULL,                     0, 0, false, false, false, NULL }
 685 };
 686
 687 /* Push current bindings for the function name VAR_DECLS.  */
 688
 689 void
 690 start_fname_decls (void)
 691 {
 692   unsigned ix;
 693   tree saved = NULL_TREE;
 694
 695   for (ix = 0; fname_vars[ix].decl; ix++)
 696     {
 697       tree decl = *fname_vars[ix].decl;
 698
 699       if (decl)
 700         {
 701           saved = tree_cons (decl, build_int_cst (NULL_TREE, ix), saved);
 702           *fname_vars[ix].decl = NULL_TREE;
 703         }
 704     }
 705   if (saved || saved_function_name_decls)
 706     /* Normally they'll have been NULL, so only push if we've got a
 707        stack, or they are non-NULL.  */
 708     saved_function_name_decls = tree_cons (saved, NULL_TREE,
 709                                            saved_function_name_decls);
 710 }
 711
 712 /* Finish up the current bindings, adding them into the current function's
 713    statement tree.  This must be done _before_ finish_stmt_tree is called.
 714    If there is no current function, we must be at file scope and no statements
 715    are involved. Pop the previous bindings.  */
 716
 717 void
 718 finish_fname_decls (void)
 719 {
 720   unsigned ix;
 721   tree stmts = NULL_TREE;
 722   tree stack = saved_function_name_decls;
 723
 724   for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack))
 725     append_to_statement_list (TREE_VALUE (stack), &stmts);
 726
 727   if (stmts)
 728     {
 729       tree *bodyp = &DECL_SAVED_TREE (current_function_decl);
 730
 731       if (TREE_CODE (*bodyp) == BIND_EXPR)
 732         bodyp = &BIND_EXPR_BODY (*bodyp);
 733
 734       append_to_statement_list_force (*bodyp, &stmts);
 735       *bodyp = stmts;
 736     }
 737
 738   for (ix = 0; fname_vars[ix].decl; ix++)
 739     *fname_vars[ix].decl = NULL_TREE;
 740
 741   if (stack)
 742     {
 743       /* We had saved values, restore them.  */
 744       tree saved;
 745
 746       for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved))
 747         {
 748           tree decl = TREE_PURPOSE (saved);
 749           unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved));
 750
 751           *fname_vars[ix].decl = decl;
 752         }
 753       stack = TREE_CHAIN (stack);
 754     }
 755   saved_function_name_decls = stack;
 756 }
 757
 758 /* Return the text name of the current function, suitably prettified
 759    by PRETTY_P.  Return string must be freed by caller.  */
 760
 761 const char *
 762 fname_as_string (int pretty_p)
 763 {
 764   const char *name = "top level";
 765   char *namep;
 766   int vrb = 2, len;
 767   cpp_string cstr = { 0, 0 }, strname;
 768
 769   if (!pretty_p)
 770     {
 771       name = "";
 772       vrb = 0;
 773     }
 774
 775   if (current_function_decl)
 776     name = lang_hooks.decl_printable_name (current_function_decl, vrb);
 777
 778   len = strlen (name) + 3; /* Two for '"'s.  One for NULL.  */
 779
 780   namep = XNEWVEC (char, len);
 781   snprintf (namep, len, "\"%s\"", name);
 782   strname.text = (unsigned char *) namep;
 783   strname.len = len - 1;
 784
 785   if (cpp_interpret_string (parse_in, &strname, 1, &cstr, false))
 786     {
 787       XDELETEVEC (namep);
 788       return (const char *) cstr.text;
 789     }
 790
 791   return namep;
 792 }
 793
 794 /* Expand DECL if it declares an entity not handled by the
 795    common code.  */
 796
 797 int
 798 c_expand_decl (tree decl)
 799 {
 800   if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl))
 801     {
 802       /* Let the back-end know about this variable.  */
 803       if (!anon_aggr_type_p (TREE_TYPE (decl)))
 804         emit_local_var (decl);
 805       else
 806         expand_anon_union_decl (decl, NULL_TREE,
 807                                 DECL_ANON_UNION_ELEMS (decl));
 808     }
 809   else
 810     return 0;
 811
 812   return 1;
 813 }
 814
 815
 816 /* Return the VAR_DECL for a const char array naming the current
 817    function. If the VAR_DECL has not yet been created, create it
 818    now. RID indicates how it should be formatted and IDENTIFIER_NODE
 819    ID is its name (unfortunately C and C++ hold the RID values of
 820    keywords in different places, so we can't derive RID from ID in
 821    this language independent code.  */
 822
 823 tree
 824 fname_decl (unsigned int rid, tree id)
 825 {
 826   unsigned ix;
 827   tree decl = NULL_TREE;
 828
 829   for (ix = 0; fname_vars[ix].decl; ix++)
 830     if (fname_vars[ix].rid == rid)
 831       break;
 832
 833   decl = *fname_vars[ix].decl;
 834   if (!decl)
 835     {
 836       /* If a tree is built here, it would normally have the lineno of
 837          the current statement.  Later this tree will be moved to the
 838          beginning of the function and this line number will be wrong.
 839          To avoid this problem set the lineno to 0 here; that prevents
 840          it from appearing in the RTL.  */
 841       tree stmts;
 842       location_t saved_location = input_location;
 843 #ifdef USE_MAPPED_LOCATION
 844       input_location = UNKNOWN_LOCATION;
 845 #else
 846       input_line = 0;
 847 #endif
 848
 849       stmts = push_stmt_list ();
 850       decl = (*make_fname_decl) (id, fname_vars[ix].pretty);
 851       stmts = pop_stmt_list (stmts);
 852       if (!IS_EMPTY_STMT (stmts))
 853         saved_function_name_decls
 854           = tree_cons (decl, stmts, saved_function_name_decls);
 855       *fname_vars[ix].decl = decl;
 856       input_location = saved_location;
 857     }
 858   if (!ix && !current_function_decl)
 859     pedwarn ("%qD is not defined outside of function scope", decl);
 860
 861   return decl;
 862 }
 863
 864 /* Given a STRING_CST, give it a suitable array-of-chars data type.  */
 865
 866 tree
 867 fix_string_type (tree value)
 868 {
 869   const int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
 870   const int wide_flag = TREE_TYPE (value) == wchar_array_type_node;
 871   int length = TREE_STRING_LENGTH (value);
 872   int nchars;
 873   tree e_type, i_type, a_type;
 874
 875   /* Compute the number of elements, for the array type.  */
 876   nchars = wide_flag ? length / wchar_bytes : length;
 877
 878   /* C89 2.2.4.1, C99 5.2.4.1 (Translation limits).  The analogous
 879      limit in C++98 Annex B is very large (65536) and is not normative,
 880      so we do not diagnose it (warn_overlength_strings is forced off
 881      in c_common_post_options).  */
 882   if (warn_overlength_strings)
 883     {
 884       const int nchars_max = flag_isoc99 ? 4095 : 509;
 885       const int relevant_std = flag_isoc99 ? 99 : 90;
 886       if (nchars - 1 > nchars_max)
 887         /* Translators: The %d after 'ISO C' will be 90 or 99.  Do not
 888            separate the %d from the 'C'.  'ISO' should not be
 889            translated, but it may be moved after 'C%d' in languages
 890            where modifiers follow nouns.  */
 891         pedwarn ("string length %qd is greater than the length %qd "
 892                  "ISO C%d compilers are required to support",
 893                  nchars - 1, nchars_max, relevant_std);
 894     }
 895
 896   /* Create the array type for the string constant.  The ISO C++
 897      standard says that a string literal has type `const char[N]' or
 898      `const wchar_t[N]'.  We use the same logic when invoked as a C
 899      front-end with -Wwrite-strings.
 900      ??? We should change the type of an expression depending on the
 901      state of a warning flag.  We should just be warning -- see how
 902      this is handled in the C++ front-end for the deprecated implicit
 903      conversion from string literals to `char*' or `wchar_t*'.
 904
 905      The C++ front end relies on TYPE_MAIN_VARIANT of a cv-qualified
 906      array type being the unqualified version of that type.
 907      Therefore, if we are constructing an array of const char, we must
 908      construct the matching unqualified array type first.  The C front
 909      end does not require this, but it does no harm, so we do it
 910      unconditionally.  */
 911   e_type = wide_flag ? wchar_type_node : char_type_node;
 912   i_type = build_index_type (build_int_cst (NULL_TREE, nchars - 1));
 913   a_type = build_array_type (e_type, i_type);
 914   if (c_dialect_cxx() || warn_write_strings)
 915     a_type = c_build_qualified_type (a_type, TYPE_QUAL_CONST);
 916
 917   TREE_TYPE (value) = a_type;
 918   TREE_CONSTANT (value) = 1;
 919   TREE_INVARIANT (value) = 1;
 920   TREE_READONLY (value) = 1;
 921   TREE_STATIC (value) = 1;
 922   return value;
 923 }
 924 \f
 925 /* Print a warning if a constant expression had overflow in folding.
 926    Invoke this function on every expression that the language
 927    requires to be a constant expression.
 928    Note the ANSI C standard says it is erroneous for a
 929    constant expression to overflow.  */
 930
 931 void
 932 constant_expression_warning (tree value)
 933 {
 934   if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
 935        || TREE_CODE (value) == FIXED_CST
 936        || TREE_CODE (value) == VECTOR_CST
 937        || TREE_CODE (value) == COMPLEX_CST)
 938       && TREE_OVERFLOW (value)
 939       && warn_overflow
 940       && pedantic)
 941     pedwarn ("overflow in constant expression");
 942 }
 943
 944 /* Print a warning if an expression had overflow in folding and its
 945    operands hadn't.
 946
 947    Invoke this function on every expression that
 948    (1) appears in the source code, and
 949    (2) is a constant expression that overflowed, and
 950    (3) is not already checked by convert_and_check;
 951    however, do not invoke this function on operands of explicit casts
 952    or when the expression is the result of an operator and any operand
 953    already overflowed.  */
 954
 955 void
 956 overflow_warning (tree value)
 957 {
 958   if (skip_evaluation) return;
 959
 960   switch (TREE_CODE (value))
 961     {
 962     case INTEGER_CST:
 963       warning (OPT_Woverflow, "integer overflow in expression");
 964       break;
 965
 966     case REAL_CST:
 967       warning (OPT_Woverflow, "floating point overflow in expression");
 968       break;
 969
 970     case FIXED_CST:
 971       warning (OPT_Woverflow, "fixed-point overflow in expression");
 972       break;
 973
 974     case VECTOR_CST:
 975       warning (OPT_Woverflow, "vector overflow in expression");
 976       break;
 977
 978     case COMPLEX_CST:
 979       if (TREE_CODE (TREE_REALPART (value)) == INTEGER_CST)
 980         warning (OPT_Woverflow, "complex integer overflow in expression");
 981       else if (TREE_CODE (TREE_REALPART (value)) == REAL_CST)
 982         warning (OPT_Woverflow, "complex floating point overflow in expression");
 983       break;
 984
 985     default:
 986       break;
 987     }
 988 }
 989
 990
 991 /* Warn about use of a logical || / && operator being used in a
 992    context where it is likely that the bitwise equivalent was intended
 993    by the programmer. CODE is the TREE_CODE of the operator, ARG1
 994    and ARG2 the arguments.  */
 995
 996 void
 997 warn_logical_operator (enum tree_code code, tree arg1, tree
 998     arg2)
 999 {
1000   switch (code)
1001     {
1002       case TRUTH_ANDIF_EXPR:
1003       case TRUTH_ORIF_EXPR:
1004       case TRUTH_OR_EXPR:
1005       case TRUTH_AND_EXPR:
1006         if (!TREE_NO_WARNING (arg1)
1007             && INTEGRAL_TYPE_P (TREE_TYPE (arg1))
1008             && !CONSTANT_CLASS_P (arg1)
1009             && TREE_CODE (arg2) == INTEGER_CST
1010             && !integer_zerop (arg2))
1011           {
1012             warning (OPT_Wlogical_op,
1013                      "logical %<%s%> with non-zero constant "
1014                      "will always evaluate as true",
1015                      ((code == TRUTH_ANDIF_EXPR)
1016                       || (code == TRUTH_AND_EXPR)) ? "&&" : "||");
1017             TREE_NO_WARNING (arg1) = true;
1018           }
1019         break;
1020       default:
1021         break;
1022     }
1023 }
1024
1025
1026 /* Print a warning about casts that might indicate violation
1027    of strict aliasing rules if -Wstrict-aliasing is used and
1028    strict aliasing mode is in effect. OTYPE is the original
1029    TREE_TYPE of EXPR, and TYPE the type we're casting to. */
1030
1031 bool
1032 strict_aliasing_warning (tree otype, tree type, tree expr)
1033 {
1034   if (!(flag_strict_aliasing && POINTER_TYPE_P (type)
1035         && POINTER_TYPE_P (otype) && !VOID_TYPE_P (TREE_TYPE (type))))
1036     return false;
1037
1038   if ((warn_strict_aliasing > 1) && TREE_CODE (expr) == ADDR_EXPR
1039       && (DECL_P (TREE_OPERAND (expr, 0))
1040           || handled_component_p (TREE_OPERAND (expr, 0))))
1041     {
1042       /* Casting the address of an object to non void pointer. Warn
1043          if the cast breaks type based aliasing.  */
1044       if (!COMPLETE_TYPE_P (TREE_TYPE (type)) && warn_strict_aliasing == 2)
1045         {
1046           warning (OPT_Wstrict_aliasing, "type-punning to incomplete type "
1047                    "might break strict-aliasing rules");
1048           return true;
1049         }
1050       else
1051         {
1052           /* warn_strict_aliasing >= 3.   This includes the default (3).
1053              Only warn if the cast is dereferenced immediately.  */
1054           alias_set_type set1 =
1055             get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0)));
1056           alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1057
1058           if (!alias_sets_conflict_p (set1, set2))
1059             {
1060               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1061                        "pointer will break strict-aliasing rules");
1062               return true;
1063             }
1064           else if (warn_strict_aliasing == 2
1065                    && !alias_sets_must_conflict_p (set1, set2))
1066             {
1067               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1068                        "pointer might break strict-aliasing rules");
1069               return true;
1070             }
1071         }
1072     }
1073   else
1074     if ((warn_strict_aliasing == 1) && !VOID_TYPE_P (TREE_TYPE (otype)))
1075       {
1076         /* At this level, warn for any conversions, even if an address is
1077            not taken in the same statement.  This will likely produce many
1078            false positives, but could be useful to pinpoint problems that
1079            are not revealed at higher levels.  */
1080         alias_set_type set1 = get_alias_set (TREE_TYPE (otype));
1081         alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1082         if (!COMPLETE_TYPE_P (type)
1083             || !alias_sets_must_conflict_p (set1, set2))
1084           {
1085             warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1086                      "pointer might break strict-aliasing rules");
1087             return true;
1088           }
1089       }
1090
1091   return false;
1092 }
1093
1094 /* Print a warning about if (); or if () .. else; constructs
1095    via the special empty statement node that we create.  INNER_THEN
1096    and INNER_ELSE are the statement lists of the if and the else
1097    block.  */
1098
1099 void
1100 empty_if_body_warning (tree inner_then, tree inner_else)
1101 {
1102   if (TREE_CODE (inner_then) == STATEMENT_LIST
1103       && STATEMENT_LIST_TAIL (inner_then))
1104     inner_then = STATEMENT_LIST_TAIL (inner_then)->stmt;
1105
1106   if (inner_else && TREE_CODE (inner_else) == STATEMENT_LIST
1107       && STATEMENT_LIST_TAIL (inner_else))
1108     inner_else = STATEMENT_LIST_TAIL (inner_else)->stmt;
1109
1110   if (IS_EMPTY_STMT (inner_then) && !inner_else)
1111     warning (OPT_Wempty_body, "%Hsuggest braces around empty body "
1112              "in an %<if%> statement", EXPR_LOCUS (inner_then));
1113
1114   else if (inner_else && IS_EMPTY_STMT (inner_else))
1115     warning (OPT_Wempty_body, "%Hsuggest braces around empty body "
1116              "in an %<else%> statement", EXPR_LOCUS (inner_else));
1117 }
1118
1119 /* Warn for unlikely, improbable, or stupid DECL declarations
1120    of `main'.  */
1121
1122 void
1123 check_main_parameter_types (tree decl)
1124 {
1125   tree args;
1126   int argct = 0;
1127
1128   for (args = TYPE_ARG_TYPES (TREE_TYPE (decl)); args;
1129       args = TREE_CHAIN (args))
1130    {
1131      tree type = args ? TREE_VALUE (args) : 0;
1132
1133      if (type == void_type_node || type == error_mark_node )
1134        break;
1135
1136      ++argct;
1137      switch (argct)
1138        {
1139        case 1:
1140          if (TYPE_MAIN_VARIANT (type) != integer_type_node)
1141            pedwarn ("first argument of %q+D should be %<int%>", decl);
1142          break;
1143
1144        case 2:
1145          if (TREE_CODE (type) != POINTER_TYPE
1146              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1147              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1148                  != char_type_node))
1149            pedwarn ("second argument of %q+D should be %<char **%>",
1150                     decl);
1151          break;
1152
1153        case 3:
1154          if (TREE_CODE (type) != POINTER_TYPE
1155              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1156              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1157                  != char_type_node))
1158            pedwarn ("third argument of %q+D should probably be "
1159                     "%<char **%>", decl);
1160          break;
1161        }
1162    }
1163
1164   /* It is intentional that this message does not mention the third
1165     argument because it's only mentioned in an appendix of the
1166     standard.  */
1167   if (argct > 0 && (argct < 2 || argct > 3))
1168    pedwarn ("%q+D takes only zero or two arguments", decl);
1169 }
1170
1171 /* True if vector types T1 and T2 can be converted to each other
1172    without an explicit cast.  If EMIT_LAX_NOTE is true, and T1 and T2
1173    can only be converted with -flax-vector-conversions yet that is not
1174    in effect, emit a note telling the user about that option if such
1175    a note has not previously been emitted.  */
1176 bool
1177 vector_types_convertible_p (const_tree t1, const_tree t2, bool emit_lax_note)
1178 {
1179   static bool emitted_lax_note = false;
1180   bool convertible_lax;
1181
1182   if ((targetm.vector_opaque_p (t1) || targetm.vector_opaque_p (t2))
1183       && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)))
1184     return true;
1185
1186   convertible_lax =
1187     (tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2))
1188      && (TREE_CODE (TREE_TYPE (t1)) != REAL_TYPE ||
1189          TYPE_PRECISION (t1) == TYPE_PRECISION (t2))
1190      && (INTEGRAL_TYPE_P (TREE_TYPE (t1))
1191          == INTEGRAL_TYPE_P (TREE_TYPE (t2))));
1192
1193   if (!convertible_lax || flag_lax_vector_conversions)
1194     return convertible_lax;
1195
1196   if (TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1197       && comptypes (TREE_TYPE (t1), TREE_TYPE (t2)))
1198     return true;
1199
1200   if (emit_lax_note && !emitted_lax_note)
1201     {
1202       emitted_lax_note = true;
1203       inform ("use -flax-vector-conversions to permit "
1204               "conversions between vectors with differing "
1205               "element types or numbers of subparts");
1206     }
1207
1208   return false;
1209 }
1210
1211 /* Warns if the conversion of EXPR to TYPE may alter a value.
1212    This is a helper function for warnings_for_convert_and_check.  */
1213
1214 static void
1215 conversion_warning (tree type, tree expr)
1216 {
1217   bool give_warning = false;
1218
1219   unsigned int formal_prec = TYPE_PRECISION (type);
1220
1221   if (!warn_conversion && !warn_sign_conversion)
1222     return;
1223
1224   if (TREE_CODE (expr) == REAL_CST || TREE_CODE (expr) == INTEGER_CST)
1225     {
1226       /* Warn for real constant that is not an exact integer converted
1227          to integer type.  */
1228       if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
1229           && TREE_CODE (type) == INTEGER_TYPE)
1230         {
1231           if (!real_isinteger (TREE_REAL_CST_PTR (expr), TYPE_MODE (TREE_TYPE (expr))))
1232             give_warning = true;
1233         }
1234       /* Warn for an integer constant that does not fit into integer type.  */
1235       else if (TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
1236                && TREE_CODE (type) == INTEGER_TYPE
1237                && !int_fits_type_p (expr, type))
1238         {
1239           if (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (TREE_TYPE (expr)))
1240             warning (OPT_Wsign_conversion,
1241                      "negative integer implicitly converted to unsigned type");
1242           else if (!TYPE_UNSIGNED (type) && TYPE_UNSIGNED (TREE_TYPE (expr)))
1243             warning (OPT_Wsign_conversion,
1244                      "conversion of unsigned constant value to negative integer");
1245           else
1246             give_warning = true;
1247         }
1248       else if (TREE_CODE (type) == REAL_TYPE)
1249         {
1250           /* Warn for an integer constant that does not fit into real type.  */
1251           if (TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE)
1252             {
1253               REAL_VALUE_TYPE a = real_value_from_int_cst (0, expr);
1254               if (!exact_real_truncate (TYPE_MODE (type), &a))
1255                 give_warning = true;
1256             }
1257           /* Warn for a real constant that does not fit into a smaller
1258              real type.  */
1259           else if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
1260                    && formal_prec < TYPE_PRECISION (TREE_TYPE (expr)))
1261             {
1262               REAL_VALUE_TYPE a = TREE_REAL_CST (expr);
1263               if (!exact_real_truncate (TYPE_MODE (type), &a))
1264                 give_warning = true;
1265             }
1266         }
1267
1268       if (give_warning)
1269         warning (OPT_Wconversion,
1270                  "conversion to %qT alters %qT constant value",
1271                  type, TREE_TYPE (expr));
1272     }
1273   else /* 'expr' is not a constant.  */
1274     {
1275       /* Warn for real types converted to integer types.  */
1276       if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
1277           && TREE_CODE (type) == INTEGER_TYPE)
1278         give_warning = true;
1279
1280       else if (TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
1281                && TREE_CODE (type) == INTEGER_TYPE)
1282         {
1283           /* Don't warn about unsigned char y = 0xff, x = (int) y;  */
1284           expr = get_unwidened (expr, 0);
1285
1286           /* Warn for integer types converted to smaller integer types.  */
1287           if (formal_prec < TYPE_PRECISION (TREE_TYPE (expr)))
1288             give_warning = true;
1289
1290           /* When they are the same width but different signedness,
1291              then the value may change.  */
1292           else if ((formal_prec == TYPE_PRECISION (TREE_TYPE (expr))
1293                     && TYPE_UNSIGNED (TREE_TYPE (expr)) != TYPE_UNSIGNED (type))
1294                    /* Even when converted to a bigger type, if the type is
1295                       unsigned but expr is signed, then negative values
1296                       will be changed.  */
1297                    || (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (TREE_TYPE (expr))))
1298             warning (OPT_Wsign_conversion,
1299                      "conversion to %qT from %qT may change the sign of the result",
1300                      type, TREE_TYPE (expr));
1301         }
1302
1303       /* Warn for integer types converted to real types if and only if
1304          all the range of values of the integer type cannot be
1305          represented by the real type.  */
1306       else if (TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
1307                && TREE_CODE (type) == REAL_TYPE)
1308         {
1309           tree type_low_bound = TYPE_MIN_VALUE (TREE_TYPE (expr));
1310           tree type_high_bound = TYPE_MAX_VALUE (TREE_TYPE (expr));
1311           REAL_VALUE_TYPE real_low_bound = real_value_from_int_cst (0, type_low_bound);
1312           REAL_VALUE_TYPE real_high_bound = real_value_from_int_cst (0, type_high_bound);
1313
1314           if (!exact_real_truncate (TYPE_MODE (type), &real_low_bound)
1315               || !exact_real_truncate (TYPE_MODE (type), &real_high_bound))
1316             give_warning = true;
1317         }
1318
1319       /* Warn for real types converted to smaller real types.  */
1320       else if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
1321                && TREE_CODE (type) == REAL_TYPE
1322                && formal_prec < TYPE_PRECISION (TREE_TYPE (expr)))
1323         give_warning = true;
1324
1325
1326       if (give_warning)
1327         warning (OPT_Wconversion,
1328                  "conversion to %qT from %qT may alter its value",
1329                  type, TREE_TYPE (expr));
1330     }
1331 }
1332
1333 /* Produce warnings after a conversion. RESULT is the result of
1334    converting EXPR to TYPE.  This is a helper function for
1335    convert_and_check and cp_convert_and_check.  */
1336
1337 void
1338 warnings_for_convert_and_check (tree type, tree expr, tree result)
1339 {
1340   if (TREE_CODE (expr) == INTEGER_CST
1341       && (TREE_CODE (type) == INTEGER_TYPE
1342           || TREE_CODE (type) == ENUMERAL_TYPE)
1343       && !int_fits_type_p (expr, type))
1344     {
1345       /* Do not diagnose overflow in a constant expression merely
1346          because a conversion overflowed.  */
1347       if (TREE_OVERFLOW (result))
1348         TREE_OVERFLOW (result) = TREE_OVERFLOW (expr);
1349
1350       if (TYPE_UNSIGNED (type))
1351         {
1352           /* This detects cases like converting -129 or 256 to
1353              unsigned char.  */
1354           if (!int_fits_type_p (expr, c_common_signed_type (type)))
1355             warning (OPT_Woverflow,
1356                      "large integer implicitly truncated to unsigned type");
1357           else
1358             conversion_warning (type, expr);
1359         }
1360       else if (!int_fits_type_p (expr, c_common_unsigned_type (type)))
1361         warning (OPT_Woverflow,
1362                  "overflow in implicit constant conversion");
1363       /* No warning for converting 0x80000000 to int.  */
1364       else if (pedantic
1365                && (TREE_CODE (TREE_TYPE (expr)) != INTEGER_TYPE
1366                    || TYPE_PRECISION (TREE_TYPE (expr))
1367                    != TYPE_PRECISION (type)))
1368         warning (OPT_Woverflow,
1369                  "overflow in implicit constant conversion");
1370
1371       else
1372         conversion_warning (type, expr);
1373     }
1374   else if ((TREE_CODE (result) == INTEGER_CST
1375             || TREE_CODE (result) == FIXED_CST) && TREE_OVERFLOW (result))
1376     warning (OPT_Woverflow,
1377              "overflow in implicit constant conversion");
1378   else
1379     conversion_warning (type, expr);
1380 }
1381
1382
1383 /* Convert EXPR to TYPE, warning about conversion problems with constants.
1384    Invoke this function on every expression that is converted implicitly,
1385    i.e. because of language rules and not because of an explicit cast.  */
1386
1387 tree
1388 convert_and_check (tree type, tree expr)
1389 {
1390   tree result;
1391
1392   if (TREE_TYPE (expr) == type)
1393     return expr;
1394
1395   result = convert (type, expr);
1396
1397   if (!skip_evaluation && !TREE_OVERFLOW_P (expr) && result != error_mark_node)
1398     warnings_for_convert_and_check (type, expr, result);
1399
1400   return result;
1401 }
1402 \f
1403 /* A node in a list that describes references to variables (EXPR), which are
1404    either read accesses if WRITER is zero, or write accesses, in which case
1405    WRITER is the parent of EXPR.  */
1406 struct tlist
1407 {
1408   struct tlist *next;
1409   tree expr, writer;
1410 };
1411
1412 /* Used to implement a cache the results of a call to verify_tree.  We only
1413    use this for SAVE_EXPRs.  */
1414 struct tlist_cache
1415 {
1416   struct tlist_cache *next;
1417   struct tlist *cache_before_sp;
1418   struct tlist *cache_after_sp;
1419   tree expr;
1420 };
1421
1422 /* Obstack to use when allocating tlist structures, and corresponding
1423    firstobj.  */
1424 static struct obstack tlist_obstack;
1425 static char *tlist_firstobj = 0;
1426
1427 /* Keep track of the identifiers we've warned about, so we can avoid duplicate
1428    warnings.  */
1429 static struct tlist *warned_ids;
1430 /* SAVE_EXPRs need special treatment.  We process them only once and then
1431    cache the results.  */
1432 static struct tlist_cache *save_expr_cache;
1433
1434 static void add_tlist (struct tlist **, struct tlist *, tree, int);
1435 static void merge_tlist (struct tlist **, struct tlist *, int);
1436 static void verify_tree (tree, struct tlist **, struct tlist **, tree);
1437 static int warning_candidate_p (tree);
1438 static void warn_for_collisions (struct tlist *);
1439 static void warn_for_collisions_1 (tree, tree, struct tlist *, int);
1440 static struct tlist *new_tlist (struct tlist *, tree, tree);
1441
1442 /* Create a new struct tlist and fill in its fields.  */
1443 static struct tlist *
1444 new_tlist (struct tlist *next, tree t, tree writer)
1445 {
1446   struct tlist *l;
1447   l = XOBNEW (&tlist_obstack, struct tlist);
1448   l->next = next;
1449   l->expr = t;
1450   l->writer = writer;
1451   return l;
1452 }
1453
1454 /* Add duplicates of the nodes found in ADD to the list *TO.  If EXCLUDE_WRITER
1455    is nonnull, we ignore any node we find which has a writer equal to it.  */
1456
1457 static void
1458 add_tlist (struct tlist **to, struct tlist *add, tree exclude_writer, int copy)
1459 {
1460   while (add)
1461     {
1462       struct tlist *next = add->next;
1463       if (!copy)
1464         add->next = *to;
1465       if (!exclude_writer || add->writer != exclude_writer)
1466         *to = copy ? new_tlist (*to, add->expr, add->writer) : add;
1467       add = next;
1468     }
1469 }
1470
1471 /* Merge the nodes of ADD into TO.  This merging process is done so that for
1472    each variable that already exists in TO, no new node is added; however if
1473    there is a write access recorded in ADD, and an occurrence on TO is only
1474    a read access, then the occurrence in TO will be modified to record the
1475    write.  */
1476
1477 static void
1478 merge_tlist (struct tlist **to, struct tlist *add, int copy)
1479 {
1480   struct tlist **end = to;
1481
1482   while (*end)
1483     end = &(*end)->next;
1484
1485   while (add)
1486     {
1487       int found = 0;
1488       struct tlist *tmp2;
1489       struct tlist *next = add->next;
1490
1491       for (tmp2 = *to; tmp2; tmp2 = tmp2->next)
1492         if (tmp2->expr == add->expr)
1493           {
1494             found = 1;
1495             if (!tmp2->writer)
1496               tmp2->writer = add->writer;
1497           }
1498       if (!found)
1499         {
1500           *end = copy ? add : new_tlist (NULL, add->expr, add->writer);
1501           end = &(*end)->next;
1502           *end = 0;
1503         }
1504       add = next;
1505     }
1506 }
1507
1508 /* WRITTEN is a variable, WRITER is its parent.  Warn if any of the variable
1509    references in list LIST conflict with it, excluding reads if ONLY writers
1510    is nonzero.  */
1511
1512 static void
1513 warn_for_collisions_1 (tree written, tree writer, struct tlist *list,
1514                        int only_writes)
1515 {
1516   struct tlist *tmp;
1517
1518   /* Avoid duplicate warnings.  */
1519   for (tmp = warned_ids; tmp; tmp = tmp->next)
1520     if (tmp->expr == written)
1521       return;
1522
1523   while (list)
1524     {
1525       if (list->expr == written
1526           && list->writer != writer
1527           && (!only_writes || list->writer)
1528           && DECL_NAME (list->expr))
1529         {
1530           warned_ids = new_tlist (warned_ids, written, NULL_TREE);
1531           warning (0, "operation on %qE may be undefined", list->expr);
1532         }
1533       list = list->next;
1534     }
1535 }
1536
1537 /* Given a list LIST of references to variables, find whether any of these
1538    can cause conflicts due to missing sequence points.  */
1539
1540 static void
1541 warn_for_collisions (struct tlist *list)
1542 {
1543   struct tlist *tmp;
1544
1545   for (tmp = list; tmp; tmp = tmp->next)
1546     {
1547       if (tmp->writer)
1548         warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0);
1549     }
1550 }
1551
1552 /* Return nonzero if X is a tree that can be verified by the sequence point
1553    warnings.  */
1554 static int
1555 warning_candidate_p (tree x)
1556 {
1557   return TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == PARM_DECL;
1558 }
1559
1560 /* Walk the tree X, and record accesses to variables.  If X is written by the
1561    parent tree, WRITER is the parent.
1562    We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP.  If this
1563    expression or its only operand forces a sequence point, then everything up
1564    to the sequence point is stored in PBEFORE_SP.  Everything else gets stored
1565    in PNO_SP.
1566    Once we return, we will have emitted warnings if any subexpression before
1567    such a sequence point could be undefined.  On a higher level, however, the
1568    sequence point may not be relevant, and we'll merge the two lists.
1569
1570    Example: (b++, a) + b;
1571    The call that processes the COMPOUND_EXPR will store the increment of B
1572    in PBEFORE_SP, and the use of A in PNO_SP.  The higher-level call that
1573    processes the PLUS_EXPR will need to merge the two lists so that
1574    eventually, all accesses end up on the same list (and we'll warn about the
1575    unordered subexpressions b++ and b.
1576
1577    A note on merging.  If we modify the former example so that our expression
1578    becomes
1579      (b++, b) + a
1580    care must be taken not simply to add all three expressions into the final
1581    PNO_SP list.  The function merge_tlist takes care of that by merging the
1582    before-SP list of the COMPOUND_EXPR into its after-SP list in a special
1583    way, so that no more than one access to B is recorded.  */
1584
1585 static void
1586 verify_tree (tree x, struct tlist **pbefore_sp, struct tlist **pno_sp,
1587              tree writer)
1588 {
1589   struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3;
1590   enum tree_code code;
1591   enum tree_code_class cl;
1592
1593   /* X may be NULL if it is the operand of an empty statement expression
1594      ({ }).  */
1595   if (x == NULL)
1596     return;
1597
1598  restart:
1599   code = TREE_CODE (x);
1600   cl = TREE_CODE_CLASS (code);
1601
1602   if (warning_candidate_p (x))
1603     {
1604       *pno_sp = new_tlist (*pno_sp, x, writer);
1605       return;
1606     }
1607
1608   switch (code)
1609     {
1610     case CONSTRUCTOR:
1611       return;
1612
1613     case COMPOUND_EXPR:
1614     case TRUTH_ANDIF_EXPR:
1615     case TRUTH_ORIF_EXPR:
1616       tmp_before = tmp_nosp = tmp_list3 = 0;
1617       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1618       warn_for_collisions (tmp_nosp);
1619       merge_tlist (pbefore_sp, tmp_before, 0);
1620       merge_tlist (pbefore_sp, tmp_nosp, 0);
1621       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE);
1622       merge_tlist (pbefore_sp, tmp_list3, 0);
1623       return;
1624
1625     case COND_EXPR:
1626       tmp_before = tmp_list2 = 0;
1627       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE);
1628       warn_for_collisions (tmp_list2);
1629       merge_tlist (pbefore_sp, tmp_before, 0);
1630       merge_tlist (pbefore_sp, tmp_list2, 1);
1631
1632       tmp_list3 = tmp_nosp = 0;
1633       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE);
1634       warn_for_collisions (tmp_nosp);
1635       merge_tlist (pbefore_sp, tmp_list3, 0);
1636
1637       tmp_list3 = tmp_list2 = 0;
1638       verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE);
1639       warn_for_collisions (tmp_list2);
1640       merge_tlist (pbefore_sp, tmp_list3, 0);
1641       /* Rather than add both tmp_nosp and tmp_list2, we have to merge the
1642          two first, to avoid warning for (a ? b++ : b++).  */
1643       merge_tlist (&tmp_nosp, tmp_list2, 0);
1644       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1645       return;
1646
1647     case PREDECREMENT_EXPR:
1648     case PREINCREMENT_EXPR:
1649     case POSTDECREMENT_EXPR:
1650     case POSTINCREMENT_EXPR:
1651       verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x);
1652       return;
1653
1654     case MODIFY_EXPR:
1655       tmp_before = tmp_nosp = tmp_list3 = 0;
1656       verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE);
1657       verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x);
1658       /* Expressions inside the LHS are not ordered wrt. the sequence points
1659          in the RHS.  Example:
1660            *a = (a++, 2)
1661          Despite the fact that the modification of "a" is in the before_sp
1662          list (tmp_before), it conflicts with the use of "a" in the LHS.
1663          We can handle this by adding the contents of tmp_list3
1664          to those of tmp_before, and redoing the collision warnings for that
1665          list.  */
1666       add_tlist (&tmp_before, tmp_list3, x, 1);
1667       warn_for_collisions (tmp_before);
1668       /* Exclude the LHS itself here; we first have to merge it into the
1669          tmp_nosp list.  This is done to avoid warning for "a = a"; if we
1670          didn't exclude the LHS, we'd get it twice, once as a read and once
1671          as a write.  */
1672       add_tlist (pno_sp, tmp_list3, x, 0);
1673       warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1);
1674
1675       merge_tlist (pbefore_sp, tmp_before, 0);
1676       if (warning_candidate_p (TREE_OPERAND (x, 0)))
1677         merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0);
1678       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1);
1679       return;
1680
1681     case CALL_EXPR:
1682       /* We need to warn about conflicts among arguments and conflicts between
1683          args and the function address.  Side effects of the function address,
1684          however, are not ordered by the sequence point of the call.  */
1685       {
1686         call_expr_arg_iterator iter;
1687         tree arg;
1688         tmp_before = tmp_nosp = 0;
1689         verify_tree (CALL_EXPR_FN (x), &tmp_before, &tmp_nosp, NULL_TREE);
1690         FOR_EACH_CALL_EXPR_ARG (arg, iter, x)
1691           {
1692             tmp_list2 = tmp_list3 = 0;
1693             verify_tree (arg, &tmp_list2, &tmp_list3, NULL_TREE);
1694             merge_tlist (&tmp_list3, tmp_list2, 0);
1695             add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0);
1696           }
1697         add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0);
1698         warn_for_collisions (tmp_before);
1699         add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0);
1700         return;
1701       }
1702
1703     case TREE_LIST:
1704       /* Scan all the list, e.g. indices of multi dimensional array.  */
1705       while (x)
1706         {
1707           tmp_before = tmp_nosp = 0;
1708           verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE);
1709           merge_tlist (&tmp_nosp, tmp_before, 0);
1710           add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1711           x = TREE_CHAIN (x);
1712         }
1713       return;
1714
1715     case SAVE_EXPR:
1716       {
1717         struct tlist_cache *t;
1718         for (t = save_expr_cache; t; t = t->next)
1719           if (t->expr == x)
1720             break;
1721
1722         if (!t)
1723           {
1724             t = XOBNEW (&tlist_obstack, struct tlist_cache);
1725             t->next = save_expr_cache;
1726             t->expr = x;
1727             save_expr_cache = t;
1728
1729             tmp_before = tmp_nosp = 0;
1730             verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1731             warn_for_collisions (tmp_nosp);
1732
1733             tmp_list3 = 0;
1734             while (tmp_nosp)
1735               {
1736                 struct tlist *t = tmp_nosp;
1737                 tmp_nosp = t->next;
1738                 merge_tlist (&tmp_list3, t, 0);
1739               }
1740             t->cache_before_sp = tmp_before;
1741             t->cache_after_sp = tmp_list3;
1742           }
1743         merge_tlist (pbefore_sp, t->cache_before_sp, 1);
1744         add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1);
1745         return;
1746       }
1747
1748     default:
1749       /* For other expressions, simply recurse on their operands.
1750          Manual tail recursion for unary expressions.
1751          Other non-expressions need not be processed.  */
1752       if (cl == tcc_unary)
1753         {
1754           x = TREE_OPERAND (x, 0);
1755           writer = 0;
1756           goto restart;
1757         }
1758       else if (IS_EXPR_CODE_CLASS (cl))
1759         {
1760           int lp;
1761           int max = TREE_OPERAND_LENGTH (x);
1762           for (lp = 0; lp < max; lp++)
1763             {
1764               tmp_before = tmp_nosp = 0;
1765               verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, 0);
1766               merge_tlist (&tmp_nosp, tmp_before, 0);
1767               add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1768             }
1769         }
1770       return;
1771     }
1772 }
1773
1774 /* Try to warn for undefined behavior in EXPR due to missing sequence
1775    points.  */
1776
1777 void
1778 verify_sequence_points (tree expr)
1779 {
1780   struct tlist *before_sp = 0, *after_sp = 0;
1781
1782   warned_ids = 0;
1783   save_expr_cache = 0;
1784   if (tlist_firstobj == 0)
1785     {
1786       gcc_obstack_init (&tlist_obstack);
1787       tlist_firstobj = (char *) obstack_alloc (&tlist_obstack, 0);
1788     }
1789
1790   verify_tree (expr, &before_sp, &after_sp, 0);
1791   warn_for_collisions (after_sp);
1792   obstack_free (&tlist_obstack, tlist_firstobj);
1793 }
1794 \f
1795 /* Validate the expression after `case' and apply default promotions.  */
1796
1797 static tree
1798 check_case_value (tree value)
1799 {
1800   if (value == NULL_TREE)
1801     return value;
1802
1803   /* ??? Can we ever get nops here for a valid case value?  We
1804      shouldn't for C.  */
1805   STRIP_TYPE_NOPS (value);
1806   /* In C++, the following is allowed:
1807
1808        const int i = 3;
1809        switch (...) { case i: ... }
1810
1811      So, we try to reduce the VALUE to a constant that way.  */
1812   if (c_dialect_cxx ())
1813     {
1814       value = decl_constant_value (value);
1815       STRIP_TYPE_NOPS (value);
1816       value = fold (value);
1817     }
1818
1819   if (TREE_CODE (value) == INTEGER_CST)
1820     /* Promote char or short to int.  */
1821     value = perform_integral_promotions (value);
1822   else if (value != error_mark_node)
1823     {
1824       error ("case label does not reduce to an integer constant");
1825       value = error_mark_node;
1826     }
1827
1828   constant_expression_warning (value);
1829
1830   return value;
1831 }
1832 \f
1833 /* See if the case values LOW and HIGH are in the range of the original
1834    type (i.e. before the default conversion to int) of the switch testing
1835    expression.
1836    TYPE is the promoted type of the testing expression, and ORIG_TYPE is
1837    the type before promoting it.  CASE_LOW_P is a pointer to the lower
1838    bound of the case label, and CASE_HIGH_P is the upper bound or NULL
1839    if the case is not a case range.
1840    The caller has to make sure that we are not called with NULL for
1841    CASE_LOW_P (i.e. the default case).
1842    Returns true if the case label is in range of ORIG_TYPE (saturated or
1843    untouched) or false if the label is out of range.  */
1844
1845 static bool
1846 check_case_bounds (tree type, tree orig_type,
1847                    tree *case_low_p, tree *case_high_p)
1848 {
1849   tree min_value, max_value;
1850   tree case_low = *case_low_p;
1851   tree case_high = case_high_p ? *case_high_p : case_low;
1852
1853   /* If there was a problem with the original type, do nothing.  */
1854   if (orig_type == error_mark_node)
1855     return true;
1856
1857   min_value = TYPE_MIN_VALUE (orig_type);
1858   max_value = TYPE_MAX_VALUE (orig_type);
1859
1860   /* Case label is less than minimum for type.  */
1861   if (tree_int_cst_compare (case_low, min_value) < 0
1862       && tree_int_cst_compare (case_high, min_value) < 0)
1863     {
1864       warning (0, "case label value is less than minimum value for type");
1865       return false;
1866     }
1867
1868   /* Case value is greater than maximum for type.  */
1869   if (tree_int_cst_compare (case_low, max_value) > 0
1870       && tree_int_cst_compare (case_high, max_value) > 0)
1871     {
1872       warning (0, "case label value exceeds maximum value for type");
1873       return false;
1874     }
1875
1876   /* Saturate lower case label value to minimum.  */
1877   if (tree_int_cst_compare (case_high, min_value) >= 0
1878       && tree_int_cst_compare (case_low, min_value) < 0)
1879     {
1880       warning (0, "lower value in case label range"
1881                " less than minimum value for type");
1882       case_low = min_value;
1883     }
1884
1885   /* Saturate upper case label value to maximum.  */
1886   if (tree_int_cst_compare (case_low, max_value) <= 0
1887       && tree_int_cst_compare (case_high, max_value) > 0)
1888     {
1889       warning (0, "upper value in case label range"
1890                " exceeds maximum value for type");
1891       case_high = max_value;
1892     }
1893
1894   if (*case_low_p != case_low)
1895     *case_low_p = convert (type, case_low);
1896   if (case_high_p && *case_high_p != case_high)
1897     *case_high_p = convert (type, case_high);
1898
1899   return true;
1900 }
1901 \f
1902 /* Return an integer type with BITS bits of precision,
1903    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
1904
1905 tree
1906 c_common_type_for_size (unsigned int bits, int unsignedp)
1907 {
1908   if (bits == TYPE_PRECISION (integer_type_node))
1909     return unsignedp ? unsigned_type_node : integer_type_node;
1910
1911   if (bits == TYPE_PRECISION (signed_char_type_node))
1912     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1913
1914   if (bits == TYPE_PRECISION (short_integer_type_node))
1915     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1916
1917   if (bits == TYPE_PRECISION (long_integer_type_node))
1918     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1919
1920   if (bits == TYPE_PRECISION (long_long_integer_type_node))
1921     return (unsignedp ? long_long_unsigned_type_node
1922             : long_long_integer_type_node);
1923
1924   if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
1925     return (unsignedp ? widest_unsigned_literal_type_node
1926             : widest_integer_literal_type_node);
1927
1928   if (bits <= TYPE_PRECISION (intQI_type_node))
1929     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1930
1931   if (bits <= TYPE_PRECISION (intHI_type_node))
1932     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1933
1934   if (bits <= TYPE_PRECISION (intSI_type_node))
1935     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1936
1937   if (bits <= TYPE_PRECISION (intDI_type_node))
1938     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1939
1940   return 0;
1941 }
1942
1943 /* Return a fixed-point type that has at least IBIT ibits and FBIT fbits
1944    that is unsigned if UNSIGNEDP is nonzero, otherwise signed;
1945    and saturating if SATP is nonzero, otherwise not saturating.  */
1946
1947 tree
1948 c_common_fixed_point_type_for_size (unsigned int ibit, unsigned int fbit,
1949                                     int unsignedp, int satp)
1950 {
1951   enum machine_mode mode;
1952   if (ibit == 0)
1953     mode = unsignedp ? UQQmode : QQmode;
1954   else
1955     mode = unsignedp ? UHAmode : HAmode;
1956
1957   for (; mode != VOIDmode; mode = GET_MODE_WIDER_MODE (mode))
1958     if (GET_MODE_IBIT (mode) >= ibit && GET_MODE_FBIT (mode) >= fbit)
1959       break;
1960
1961   if (mode == VOIDmode || !targetm.scalar_mode_supported_p (mode))
1962     {
1963       sorry ("GCC cannot support operators with integer types and "
1964              "fixed-point types that have too many integral and "
1965              "fractional bits together");
1966       return 0;
1967     }
1968
1969   return c_common_type_for_mode (mode, satp);
1970 }
1971
1972 /* Used for communication between c_common_type_for_mode and
1973    c_register_builtin_type.  */
1974 static GTY(()) tree registered_builtin_types;
1975
1976 /* Return a data type that has machine mode MODE.
1977    If the mode is an integer,
1978    then UNSIGNEDP selects between signed and unsigned types.
1979    If the mode is a fixed-point mode,
1980    then UNSIGNEDP selects between saturating and nonsaturating types.  */
1981
1982 tree
1983 c_common_type_for_mode (enum machine_mode mode, int unsignedp)
1984 {
1985   tree t;
1986
1987   if (mode == TYPE_MODE (integer_type_node))
1988     return unsignedp ? unsigned_type_node : integer_type_node;
1989
1990   if (mode == TYPE_MODE (signed_char_type_node))
1991     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1992
1993   if (mode == TYPE_MODE (short_integer_type_node))
1994     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1995
1996   if (mode == TYPE_MODE (long_integer_type_node))
1997     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1998
1999   if (mode == TYPE_MODE (long_long_integer_type_node))
2000     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
2001
2002   if (mode == TYPE_MODE (widest_integer_literal_type_node))
2003     return unsignedp ? widest_unsigned_literal_type_node
2004                      : widest_integer_literal_type_node;
2005
2006   if (mode == QImode)
2007     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2008
2009   if (mode == HImode)
2010     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2011
2012   if (mode == SImode)
2013     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2014
2015   if (mode == DImode)
2016     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2017
2018 #if HOST_BITS_PER_WIDE_INT >= 64
2019   if (mode == TYPE_MODE (intTI_type_node))
2020     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
2021 #endif
2022
2023   if (mode == TYPE_MODE (float_type_node))
2024     return float_type_node;
2025
2026   if (mode == TYPE_MODE (double_type_node))
2027     return double_type_node;
2028
2029   if (mode == TYPE_MODE (long_double_type_node))
2030     return long_double_type_node;
2031
2032   if (mode == TYPE_MODE (void_type_node))
2033     return void_type_node;
2034
2035   if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
2036     return (unsignedp
2037             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2038             : make_signed_type (GET_MODE_PRECISION (mode)));
2039
2040   if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
2041     return (unsignedp
2042             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2043             : make_signed_type (GET_MODE_PRECISION (mode)));
2044
2045   if (COMPLEX_MODE_P (mode))
2046     {
2047       enum machine_mode inner_mode;
2048       tree inner_type;
2049
2050       if (mode == TYPE_MODE (complex_float_type_node))
2051         return complex_float_type_node;
2052       if (mode == TYPE_MODE (complex_double_type_node))
2053         return complex_double_type_node;
2054       if (mode == TYPE_MODE (complex_long_double_type_node))
2055         return complex_long_double_type_node;
2056
2057       if (mode == TYPE_MODE (complex_integer_type_node) && !unsignedp)
2058         return complex_integer_type_node;
2059
2060       inner_mode = GET_MODE_INNER (mode);
2061       inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2062       if (inner_type != NULL_TREE)
2063         return build_complex_type (inner_type);
2064     }
2065   else if (VECTOR_MODE_P (mode))
2066     {
2067       enum machine_mode inner_mode = GET_MODE_INNER (mode);
2068       tree inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2069       if (inner_type != NULL_TREE)
2070         return build_vector_type_for_mode (inner_type, mode);
2071     }
2072
2073   if (mode == TYPE_MODE (dfloat32_type_node))
2074     return dfloat32_type_node;
2075   if (mode == TYPE_MODE (dfloat64_type_node))
2076     return dfloat64_type_node;
2077   if (mode == TYPE_MODE (dfloat128_type_node))
2078     return dfloat128_type_node;
2079
2080   if (ALL_SCALAR_FIXED_POINT_MODE_P (mode))
2081     {
2082       if (mode == TYPE_MODE (short_fract_type_node))
2083         return unsignedp ? sat_short_fract_type_node : short_fract_type_node;
2084       if (mode == TYPE_MODE (fract_type_node))
2085         return unsignedp ? sat_fract_type_node : fract_type_node;
2086       if (mode == TYPE_MODE (long_fract_type_node))
2087         return unsignedp ? sat_long_fract_type_node : long_fract_type_node;
2088       if (mode == TYPE_MODE (long_long_fract_type_node))
2089         return unsignedp ? sat_long_long_fract_type_node
2090                          : long_long_fract_type_node;
2091
2092       if (mode == TYPE_MODE (unsigned_short_fract_type_node))
2093         return unsignedp ? sat_unsigned_short_fract_type_node
2094                          : unsigned_short_fract_type_node;
2095       if (mode == TYPE_MODE (unsigned_fract_type_node))
2096         return unsignedp ? sat_unsigned_fract_type_node
2097                          : unsigned_fract_type_node;
2098       if (mode == TYPE_MODE (unsigned_long_fract_type_node))
2099         return unsignedp ? sat_unsigned_long_fract_type_node
2100                          : unsigned_long_fract_type_node;
2101       if (mode == TYPE_MODE (unsigned_long_long_fract_type_node))
2102         return unsignedp ? sat_unsigned_long_long_fract_type_node
2103                          : unsigned_long_long_fract_type_node;
2104
2105       if (mode == TYPE_MODE (short_accum_type_node))
2106         return unsignedp ? sat_short_accum_type_node : short_accum_type_node;
2107       if (mode == TYPE_MODE (accum_type_node))
2108         return unsignedp ? sat_accum_type_node : accum_type_node;
2109       if (mode == TYPE_MODE (long_accum_type_node))
2110         return unsignedp ? sat_long_accum_type_node : long_accum_type_node;
2111       if (mode == TYPE_MODE (long_long_accum_type_node))
2112         return unsignedp ? sat_long_long_accum_type_node
2113                          : long_long_accum_type_node;
2114
2115       if (mode == TYPE_MODE (unsigned_short_accum_type_node))
2116         return unsignedp ? sat_unsigned_short_accum_type_node
2117                          : unsigned_short_accum_type_node;
2118       if (mode == TYPE_MODE (unsigned_accum_type_node))
2119         return unsignedp ? sat_unsigned_accum_type_node
2120                          : unsigned_accum_type_node;
2121       if (mode == TYPE_MODE (unsigned_long_accum_type_node))
2122         return unsignedp ? sat_unsigned_long_accum_type_node
2123                          : unsigned_long_accum_type_node;
2124       if (mode == TYPE_MODE (unsigned_long_long_accum_type_node))
2125         return unsignedp ? sat_unsigned_long_long_accum_type_node
2126                          : unsigned_long_long_accum_type_node;
2127
2128       if (mode == QQmode)
2129         return unsignedp ? sat_qq_type_node : qq_type_node;
2130       if (mode == HQmode)
2131         return unsignedp ? sat_hq_type_node : hq_type_node;
2132       if (mode == SQmode)
2133         return unsignedp ? sat_sq_type_node : sq_type_node;
2134       if (mode == DQmode)
2135         return unsignedp ? sat_dq_type_node : dq_type_node;
2136       if (mode == TQmode)
2137         return unsignedp ? sat_tq_type_node : tq_type_node;
2138
2139       if (mode == UQQmode)
2140         return unsignedp ? sat_uqq_type_node : uqq_type_node;
2141       if (mode == UHQmode)
2142         return unsignedp ? sat_uhq_type_node : uhq_type_node;
2143       if (mode == USQmode)
2144         return unsignedp ? sat_usq_type_node : usq_type_node;
2145       if (mode == UDQmode)
2146         return unsignedp ? sat_udq_type_node : udq_type_node;
2147       if (mode == UTQmode)
2148         return unsignedp ? sat_utq_type_node : utq_type_node;
2149
2150       if (mode == HAmode)
2151         return unsignedp ? sat_ha_type_node : ha_type_node;
2152       if (mode == SAmode)
2153         return unsignedp ? sat_sa_type_node : sa_type_node;
2154       if (mode == DAmode)
2155         return unsignedp ? sat_da_type_node : da_type_node;
2156       if (mode == TAmode)
2157         return unsignedp ? sat_ta_type_node : ta_type_node;
2158
2159       if (mode == UHAmode)
2160         return unsignedp ? sat_uha_type_node : uha_type_node;
2161       if (mode == USAmode)
2162         return unsignedp ? sat_usa_type_node : usa_type_node;
2163       if (mode == UDAmode)
2164         return unsignedp ? sat_uda_type_node : uda_type_node;
2165       if (mode == UTAmode)
2166         return unsignedp ? sat_uta_type_node : uta_type_node;
2167     }
2168
2169   for (t = registered_builtin_types; t; t = TREE_CHAIN (t))
2170     if (TYPE_MODE (TREE_VALUE (t)) == mode)
2171       return TREE_VALUE (t);
2172
2173   return 0;
2174 }
2175
2176 tree
2177 c_common_unsigned_type (tree type)
2178 {
2179   return c_common_signed_or_unsigned_type (1, type);
2180 }
2181
2182 /* Return a signed type the same as TYPE in other respects.  */
2183
2184 tree
2185 c_common_signed_type (tree type)
2186 {
2187   return c_common_signed_or_unsigned_type (0, type);
2188 }
2189
2190 /* Return a type the same as TYPE except unsigned or
2191    signed according to UNSIGNEDP.  */
2192
2193 tree
2194 c_common_signed_or_unsigned_type (int unsignedp, tree type)
2195 {
2196   tree type1;
2197
2198   /* This block of code emulates the behavior of the old
2199      c_common_unsigned_type. In particular, it returns
2200      long_unsigned_type_node if passed a long, even when a int would
2201      have the same size. This is necessary for warnings to work
2202      correctly in archs where sizeof(int) == sizeof(long) */
2203
2204   type1 = TYPE_MAIN_VARIANT (type);
2205   if (type1 == signed_char_type_node || type1 == char_type_node || type1 == unsigned_char_type_node)
2206     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2207   if (type1 == integer_type_node || type1 == unsigned_type_node)
2208     return unsignedp ? unsigned_type_node : integer_type_node;
2209   if (type1 == short_integer_type_node || type1 == short_unsigned_type_node)
2210     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2211   if (type1 == long_integer_type_node || type1 == long_unsigned_type_node)
2212     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2213   if (type1 == long_long_integer_type_node || type1 == long_long_unsigned_type_node)
2214     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
2215   if (type1 == widest_integer_literal_type_node || type1 == widest_unsigned_literal_type_node)
2216     return unsignedp ? widest_unsigned_literal_type_node : widest_integer_literal_type_node;
2217 #if HOST_BITS_PER_WIDE_INT >= 64
2218   if (type1 == intTI_type_node || type1 == unsigned_intTI_type_node)
2219     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
2220 #endif
2221   if (type1 == intDI_type_node || type1 == unsigned_intDI_type_node)
2222     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2223   if (type1 == intSI_type_node || type1 == unsigned_intSI_type_node)
2224     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2225   if (type1 == intHI_type_node || type1 == unsigned_intHI_type_node)
2226     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2227   if (type1 == intQI_type_node || type1 == unsigned_intQI_type_node)
2228     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2229
2230 #define C_COMMON_FIXED_TYPES(SAT,NAME) \
2231   if (type1 == SAT ## short_ ## NAME ## _type_node \
2232       || type1 == SAT ## unsigned_short_ ## NAME ## _type_node) \
2233     return unsignedp ? SAT ## unsigned_short_ ## NAME ## _type_node \
2234                      : SAT ## short_ ## NAME ## _type_node; \
2235   if (type1 == SAT ## NAME ## _type_node \
2236       || type1 == SAT ## unsigned_ ## NAME ## _type_node) \
2237     return unsignedp ? SAT ## unsigned_ ## NAME ## _type_node \
2238                      : SAT ## NAME ## _type_node; \
2239   if (type1 == SAT ## long_ ## NAME ## _type_node \
2240       || type1 == SAT ## unsigned_long_ ## NAME ## _type_node) \
2241     return unsignedp ? SAT ## unsigned_long_ ## NAME ## _type_node \
2242                      : SAT ## long_ ## NAME ## _type_node; \
2243   if (type1 == SAT ## long_long_ ## NAME ## _type_node \
2244       || type1 == SAT ## unsigned_long_long_ ## NAME ## _type_node) \
2245     return unsignedp ? SAT ## unsigned_long_long_ ## NAME ## _type_node \
2246                      : SAT ## long_long_ ## NAME ## _type_node;
2247
2248 #define C_COMMON_FIXED_MODE_TYPES(SAT,NAME) \
2249   if (type1 == SAT ## NAME ## _type_node \
2250       || type1 == SAT ## u ## NAME ## _type_node) \
2251     return unsignedp ? SAT ## u ## NAME ## _type_node \
2252                      : SAT ## NAME ## _type_node;
2253
2254   C_COMMON_FIXED_TYPES (, fract);
2255   C_COMMON_FIXED_TYPES (sat_, fract);
2256   C_COMMON_FIXED_TYPES (, accum);
2257   C_COMMON_FIXED_TYPES (sat_, accum);
2258
2259   C_COMMON_FIXED_MODE_TYPES (, qq);
2260   C_COMMON_FIXED_MODE_TYPES (, hq);
2261   C_COMMON_FIXED_MODE_TYPES (, sq);
2262   C_COMMON_FIXED_MODE_TYPES (, dq);
2263   C_COMMON_FIXED_MODE_TYPES (, tq);
2264   C_COMMON_FIXED_MODE_TYPES (sat_, qq);
2265   C_COMMON_FIXED_MODE_TYPES (sat_, hq);
2266   C_COMMON_FIXED_MODE_TYPES (sat_, sq);
2267   C_COMMON_FIXED_MODE_TYPES (sat_, dq);
2268   C_COMMON_FIXED_MODE_TYPES (sat_, tq);
2269   C_COMMON_FIXED_MODE_TYPES (, ha);
2270   C_COMMON_FIXED_MODE_TYPES (, sa);
2271   C_COMMON_FIXED_MODE_TYPES (, da);
2272   C_COMMON_FIXED_MODE_TYPES (, ta);
2273   C_COMMON_FIXED_MODE_TYPES (sat_, ha);
2274   C_COMMON_FIXED_MODE_TYPES (sat_, sa);
2275   C_COMMON_FIXED_MODE_TYPES (sat_, da);
2276   C_COMMON_FIXED_MODE_TYPES (sat_, ta);
2277
2278   /* For ENUMERAL_TYPEs in C++, must check the mode of the types, not
2279      the precision; they have precision set to match their range, but
2280      may use a wider mode to match an ABI.  If we change modes, we may
2281      wind up with bad conversions.  For INTEGER_TYPEs in C, must check
2282      the precision as well, so as to yield correct results for
2283      bit-field types.  C++ does not have these separate bit-field
2284      types, and producing a signed or unsigned variant of an
2285      ENUMERAL_TYPE may cause other problems as well.  */
2286
2287   if (!INTEGRAL_TYPE_P (type)
2288       || TYPE_UNSIGNED (type) == unsignedp)
2289     return type;
2290
2291 #define TYPE_OK(node)                                                       \
2292   (TYPE_MODE (type) == TYPE_MODE (node)                                     \
2293    && (c_dialect_cxx () || TYPE_PRECISION (type) == TYPE_PRECISION (node)))
2294   if (TYPE_OK (signed_char_type_node))
2295     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2296   if (TYPE_OK (integer_type_node))
2297     return unsignedp ? unsigned_type_node : integer_type_node;
2298   if (TYPE_OK (short_integer_type_node))
2299     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2300   if (TYPE_OK (long_integer_type_node))
2301     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2302   if (TYPE_OK (long_long_integer_type_node))
2303     return (unsignedp ? long_long_unsigned_type_node
2304             : long_long_integer_type_node);
2305   if (TYPE_OK (widest_integer_literal_type_node))
2306     return (unsignedp ? widest_unsigned_literal_type_node
2307             : widest_integer_literal_type_node);
2308
2309 #if HOST_BITS_PER_WIDE_INT >= 64
2310   if (TYPE_OK (intTI_type_node))
2311     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
2312 #endif
2313   if (TYPE_OK (intDI_type_node))
2314     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2315   if (TYPE_OK (intSI_type_node))
2316     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2317   if (TYPE_OK (intHI_type_node))
2318     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2319   if (TYPE_OK (intQI_type_node))
2320     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2321 #undef TYPE_OK
2322
2323   if (c_dialect_cxx ())
2324     return type;
2325   else
2326     return build_nonstandard_integer_type (TYPE_PRECISION (type), unsignedp);
2327 }
2328
2329 /* Build a bit-field integer type for the given WIDTH and UNSIGNEDP.  */
2330
2331 tree
2332 c_build_bitfield_integer_type (unsigned HOST_WIDE_INT width, int unsignedp)
2333 {
2334   /* Extended integer types of the same width as a standard type have
2335      lesser rank, so those of the same width as int promote to int or
2336      unsigned int and are valid for printf formats expecting int or
2337      unsigned int.  To avoid such special cases, avoid creating
2338      extended integer types for bit-fields if a standard integer type
2339      is available.  */
2340   if (width == TYPE_PRECISION (integer_type_node))
2341     return unsignedp ? unsigned_type_node : integer_type_node;
2342   if (width == TYPE_PRECISION (signed_char_type_node))
2343     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2344   if (width == TYPE_PRECISION (short_integer_type_node))
2345     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2346   if (width == TYPE_PRECISION (long_integer_type_node))
2347     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2348   if (width == TYPE_PRECISION (long_long_integer_type_node))
2349     return (unsignedp ? long_long_unsigned_type_node
2350             : long_long_integer_type_node);
2351   return build_nonstandard_integer_type (width, unsignedp);
2352 }
2353
2354 /* The C version of the register_builtin_type langhook.  */
2355
2356 void
2357 c_register_builtin_type (tree type, const char* name)
2358 {
2359   tree decl;
2360
2361   decl = build_decl (TYPE_DECL, get_identifier (name), type);
2362   DECL_ARTIFICIAL (decl) = 1;
2363   if (!TYPE_NAME (type))
2364     TYPE_NAME (type) = decl;
2365   pushdecl (decl);
2366
2367   registered_builtin_types = tree_cons (0, type, registered_builtin_types);
2368 }
2369
2370 \f
2371 /* Return the minimum number of bits needed to represent VALUE in a
2372    signed or unsigned type, UNSIGNEDP says which.  */
2373
2374 unsigned int
2375 min_precision (tree value, int unsignedp)
2376 {
2377   int log;
2378
2379   /* If the value is negative, compute its negative minus 1.  The latter
2380      adjustment is because the absolute value of the largest negative value
2381      is one larger than the largest positive value.  This is equivalent to
2382      a bit-wise negation, so use that operation instead.  */
2383
2384   if (tree_int_cst_sgn (value) < 0)
2385     value = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (value), value);
2386
2387   /* Return the number of bits needed, taking into account the fact
2388      that we need one more bit for a signed than unsigned type.  */
2389
2390   if (integer_zerop (value))
2391     log = 0;
2392   else
2393     log = tree_floor_log2 (value);
2394
2395   return log + 1 + !unsignedp;
2396 }
2397 \f
2398 /* Print an error message for invalid operands to arith operation
2399    CODE with TYPE0 for operand 0, and TYPE1 for operand 1.  */
2400
2401 void
2402 binary_op_error (enum tree_code code, tree type0, tree type1)
2403 {
2404   const char *opname;
2405
2406   switch (code)
2407     {
2408     case PLUS_EXPR:
2409       opname = "+"; break;
2410     case MINUS_EXPR:
2411       opname = "-"; break;
2412     case MULT_EXPR:
2413       opname = "*"; break;
2414     case MAX_EXPR:
2415       opname = "max"; break;
2416     case MIN_EXPR:
2417       opname = "min"; break;
2418     case EQ_EXPR:
2419       opname = "=="; break;
2420     case NE_EXPR:
2421       opname = "!="; break;
2422     case LE_EXPR:
2423       opname = "<="; break;
2424     case GE_EXPR:
2425       opname = ">="; break;
2426     case LT_EXPR:
2427       opname = "<"; break;
2428     case GT_EXPR:
2429       opname = ">"; break;
2430     case LSHIFT_EXPR:
2431       opname = "<<"; break;
2432     case RSHIFT_EXPR:
2433       opname = ">>"; break;
2434     case TRUNC_MOD_EXPR:
2435     case FLOOR_MOD_EXPR:
2436       opname = "%"; break;
2437     case TRUNC_DIV_EXPR:
2438     case FLOOR_DIV_EXPR:
2439       opname = "/"; break;
2440     case BIT_AND_EXPR:
2441       opname = "&"; break;
2442     case BIT_IOR_EXPR:
2443       opname = "|"; break;
2444     case TRUTH_ANDIF_EXPR:
2445       opname = "&&"; break;
2446     case TRUTH_ORIF_EXPR:
2447       opname = "||"; break;
2448     case BIT_XOR_EXPR:
2449       opname = "^"; break;
2450     default:
2451       gcc_unreachable ();
2452     }
2453   error ("invalid operands to binary %s (have %qT and %qT)", opname,
2454          type0, type1);
2455 }
2456 \f
2457 /* Subroutine of build_binary_op, used for comparison operations.
2458    See if the operands have both been converted from subword integer types
2459    and, if so, perhaps change them both back to their original type.
2460    This function is also responsible for converting the two operands
2461    to the proper common type for comparison.
2462
2463    The arguments of this function are all pointers to local variables
2464    of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
2465    RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.
2466
2467    If this function returns nonzero, it means that the comparison has
2468    a constant value.  What this function returns is an expression for
2469    that value.  */
2470
2471 tree
2472 shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr,
2473                  enum tree_code *rescode_ptr)
2474 {
2475   tree type;
2476   tree op0 = *op0_ptr;
2477   tree op1 = *op1_ptr;
2478   int unsignedp0, unsignedp1;
2479   int real1, real2;
2480   tree primop0, primop1;
2481   enum tree_code code = *rescode_ptr;
2482
2483   /* Throw away any conversions to wider types
2484      already present in the operands.  */
2485
2486   primop0 = get_narrower (op0, &unsignedp0);
2487   primop1 = get_narrower (op1, &unsignedp1);
2488
2489   /* Handle the case that OP0 does not *contain* a conversion
2490      but it *requires* conversion to FINAL_TYPE.  */
2491
2492   if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
2493     unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0));
2494   if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
2495     unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1));
2496
2497   /* If one of the operands must be floated, we cannot optimize.  */
2498   real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
2499   real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
2500
2501   /* If first arg is constant, swap the args (changing operation
2502      so value is preserved), for canonicalization.  Don't do this if
2503      the second arg is 0.  */
2504
2505   if (TREE_CONSTANT (primop0)
2506       && !integer_zerop (primop1) && !real_zerop (primop1)
2507       && !fixed_zerop (primop1))
2508     {
2509       tree tem = primop0;
2510       int temi = unsignedp0;
2511       primop0 = primop1;
2512       primop1 = tem;
2513       tem = op0;
2514       op0 = op1;
2515       op1 = tem;
2516       *op0_ptr = op0;
2517       *op1_ptr = op1;
2518       unsignedp0 = unsignedp1;
2519       unsignedp1 = temi;
2520       temi = real1;
2521       real1 = real2;
2522       real2 = temi;
2523
2524       switch (code)
2525         {
2526         case LT_EXPR:
2527           code = GT_EXPR;
2528           break;
2529         case GT_EXPR:
2530           code = LT_EXPR;
2531           break;
2532         case LE_EXPR:
2533           code = GE_EXPR;
2534           break;
2535         case GE_EXPR:
2536           code = LE_EXPR;
2537           break;
2538         default:
2539           break;
2540         }
2541       *rescode_ptr = code;
2542     }
2543
2544   /* If comparing an integer against a constant more bits wide,
2545      maybe we can deduce a value of 1 or 0 independent of the data.
2546      Or else truncate the constant now
2547      rather than extend the variable at run time.
2548
2549      This is only interesting if the constant is the wider arg.
2550      Also, it is not safe if the constant is unsigned and the
2551      variable arg is signed, since in this case the variable
2552      would be sign-extended and then regarded as unsigned.
2553      Our technique fails in this case because the lowest/highest
2554      possible unsigned results don't follow naturally from the
2555      lowest/highest possible values of the variable operand.
2556      For just EQ_EXPR and NE_EXPR there is another technique that
2557      could be used: see if the constant can be faithfully represented
2558      in the other operand's type, by truncating it and reextending it
2559      and see if that preserves the constant's value.  */
2560
2561   if (!real1 && !real2
2562       && TREE_CODE (TREE_TYPE (primop0)) != FIXED_POINT_TYPE
2563       && TREE_CODE (primop1) == INTEGER_CST
2564       && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
2565     {
2566       int min_gt, max_gt, min_lt, max_lt;
2567       tree maxval, minval;
2568       /* 1 if comparison is nominally unsigned.  */
2569       int unsignedp = TYPE_UNSIGNED (*restype_ptr);
2570       tree val;
2571
2572       type = c_common_signed_or_unsigned_type (unsignedp0,
2573                                                TREE_TYPE (primop0));
2574
2575       maxval = TYPE_MAX_VALUE (type);
2576       minval = TYPE_MIN_VALUE (type);
2577
2578       if (unsignedp && !unsignedp0)
2579         *restype_ptr = c_common_signed_type (*restype_ptr);
2580
2581       if (TREE_TYPE (primop1) != *restype_ptr)
2582         {
2583           /* Convert primop1 to target type, but do not introduce
2584              additional overflow.  We know primop1 is an int_cst.  */
2585           primop1 = force_fit_type_double (*restype_ptr,
2586                                            TREE_INT_CST_LOW (primop1),
2587                                            TREE_INT_CST_HIGH (primop1), 0,
2588                                            TREE_OVERFLOW (primop1));
2589         }
2590       if (type != *restype_ptr)
2591         {
2592           minval = convert (*restype_ptr, minval);
2593           maxval = convert (*restype_ptr, maxval);
2594         }
2595
2596       if (unsignedp && unsignedp0)
2597         {
2598           min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
2599           max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
2600           min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
2601           max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
2602         }
2603       else
2604         {
2605           min_gt = INT_CST_LT (primop1, minval);
2606           max_gt = INT_CST_LT (primop1, maxval);
2607           min_lt = INT_CST_LT (minval, primop1);
2608           max_lt = INT_CST_LT (maxval, primop1);
2609         }
2610
2611       val = 0;
2612       /* This used to be a switch, but Genix compiler can't handle that.  */
2613       if (code == NE_EXPR)
2614         {
2615           if (max_lt || min_gt)
2616             val = truthvalue_true_node;
2617         }
2618       else if (code == EQ_EXPR)
2619         {
2620           if (max_lt || min_gt)
2621             val = truthvalue_false_node;
2622         }
2623       else if (code == LT_EXPR)
2624         {
2625           if (max_lt)
2626             val = truthvalue_true_node;
2627           if (!min_lt)
2628             val = truthvalue_false_node;
2629         }
2630       else if (code == GT_EXPR)
2631         {
2632           if (min_gt)
2633             val = truthvalue_true_node;
2634           if (!max_gt)
2635             val = truthvalue_false_node;
2636         }
2637       else if (code == LE_EXPR)
2638         {
2639           if (!max_gt)
2640             val = truthvalue_true_node;
2641           if (min_gt)
2642             val = truthvalue_false_node;
2643         }
2644       else if (code == GE_EXPR)
2645         {
2646           if (!min_lt)
2647             val = truthvalue_true_node;
2648           if (max_lt)
2649             val = truthvalue_false_node;
2650         }
2651
2652       /* If primop0 was sign-extended and unsigned comparison specd,
2653          we did a signed comparison above using the signed type bounds.
2654          But the comparison we output must be unsigned.
2655
2656          Also, for inequalities, VAL is no good; but if the signed
2657          comparison had *any* fixed result, it follows that the
2658          unsigned comparison just tests the sign in reverse
2659          (positive values are LE, negative ones GE).
2660          So we can generate an unsigned comparison
2661          against an extreme value of the signed type.  */
2662
2663       if (unsignedp && !unsignedp0)
2664         {
2665           if (val != 0)
2666             switch (code)
2667               {
2668               case LT_EXPR:
2669               case GE_EXPR:
2670                 primop1 = TYPE_MIN_VALUE (type);
2671                 val = 0;
2672                 break;
2673
2674               case LE_EXPR:
2675               case GT_EXPR:
2676                 primop1 = TYPE_MAX_VALUE (type);
2677                 val = 0;
2678                 break;
2679
2680               default:
2681                 break;
2682               }
2683           type = c_common_unsigned_type (type);
2684         }
2685
2686       if (TREE_CODE (primop0) != INTEGER_CST)
2687         {
2688           if (val == truthvalue_false_node)
2689             warning (OPT_Wtype_limits, "comparison is always false due to limited range of data type");
2690           if (val == truthvalue_true_node)
2691             warning (OPT_Wtype_limits, "comparison is always true due to limited range of data type");
2692         }
2693
2694       if (val != 0)
2695         {
2696           /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2697           if (TREE_SIDE_EFFECTS (primop0))
2698             return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
2699           return val;
2700         }
2701
2702       /* Value is not predetermined, but do the comparison
2703          in the type of the operand that is not constant.
2704          TYPE is already properly set.  */
2705     }
2706
2707   /* If either arg is decimal float and the other is float, find the
2708      proper common type to use for comparison.  */
2709   else if (real1 && real2
2710            && (DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop0)))
2711                || DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop1)))))
2712     type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
2713
2714   else if (real1 && real2
2715            && (TYPE_PRECISION (TREE_TYPE (primop0))
2716                == TYPE_PRECISION (TREE_TYPE (primop1))))
2717     type = TREE_TYPE (primop0);
2718
2719   /* If args' natural types are both narrower than nominal type
2720      and both extend in the same manner, compare them
2721      in the type of the wider arg.
2722      Otherwise must actually extend both to the nominal
2723      common type lest different ways of extending
2724      alter the result.
2725      (eg, (short)-1 == (unsigned short)-1  should be 0.)  */
2726
2727   else if (unsignedp0 == unsignedp1 && real1 == real2
2728            && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
2729            && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
2730     {
2731       type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
2732       type = c_common_signed_or_unsigned_type (unsignedp0
2733                                                || TYPE_UNSIGNED (*restype_ptr),
2734                                                type);
2735       /* Make sure shorter operand is extended the right way
2736          to match the longer operand.  */
2737       primop0
2738         = convert (c_common_signed_or_unsigned_type (unsignedp0,
2739                                                      TREE_TYPE (primop0)),
2740                    primop0);
2741       primop1
2742         = convert (c_common_signed_or_unsigned_type (unsignedp1,
2743                                                      TREE_TYPE (primop1)),
2744                    primop1);
2745     }
2746   else
2747     {
2748       /* Here we must do the comparison on the nominal type
2749          using the args exactly as we received them.  */
2750       type = *restype_ptr;
2751       primop0 = op0;
2752       primop1 = op1;
2753
2754       if (!real1 && !real2 && integer_zerop (primop1)
2755           && TYPE_UNSIGNED (*restype_ptr))
2756         {
2757           tree value = 0;
2758           switch (code)
2759             {
2760             case GE_EXPR:
2761               /* All unsigned values are >= 0, so we warn.  However,
2762                  if OP0 is a constant that is >= 0, the signedness of
2763                  the comparison isn't an issue, so suppress the
2764                  warning.  */
2765               if (warn_type_limits && !in_system_header
2766                   && !(TREE_CODE (primop0) == INTEGER_CST
2767                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
2768                                                    primop0))))
2769                 warning (OPT_Wtype_limits,
2770                          "comparison of unsigned expression >= 0 is always true");
2771               value = truthvalue_true_node;
2772               break;
2773
2774             case LT_EXPR:
2775               if (warn_type_limits && !in_system_header
2776                   && !(TREE_CODE (primop0) == INTEGER_CST
2777                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
2778                                                    primop0))))
2779                 warning (OPT_Wtype_limits,
2780                          "comparison of unsigned expression < 0 is always false");
2781               value = truthvalue_false_node;
2782               break;
2783
2784             default:
2785               break;
2786             }
2787
2788           if (value != 0)
2789             {
2790               /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2791               if (TREE_SIDE_EFFECTS (primop0))
2792                 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2793                                primop0, value);
2794               return value;
2795             }
2796         }
2797     }
2798
2799   *op0_ptr = convert (type, primop0);
2800   *op1_ptr = convert (type, primop1);
2801
2802   *restype_ptr = truthvalue_type_node;
2803
2804   return 0;
2805 }
2806 \f
2807 /* Return a tree for the sum or difference (RESULTCODE says which)
2808    of pointer PTROP and integer INTOP.  */
2809
2810 tree
2811 pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
2812 {
2813   tree size_exp, ret;
2814
2815   /* The result is a pointer of the same type that is being added.  */
2816   tree result_type = TREE_TYPE (ptrop);
2817
2818   if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
2819     {
2820       if (pedantic || warn_pointer_arith)
2821         pedwarn ("pointer of type %<void *%> used in arithmetic");
2822       size_exp = integer_one_node;
2823     }
2824   else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE)
2825     {
2826       if (pedantic || warn_pointer_arith)
2827         pedwarn ("pointer to a function used in arithmetic");
2828       size_exp = integer_one_node;
2829     }
2830   else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE)
2831     {
2832       if (pedantic || warn_pointer_arith)
2833         pedwarn ("pointer to member function used in arithmetic");
2834       size_exp = integer_one_node;
2835     }
2836   else
2837     size_exp = size_in_bytes (TREE_TYPE (result_type));
2838
2839   /* We are manipulating pointer values, so we don't need to warn
2840      about relying on undefined signed overflow.  We disable the
2841      warning here because we use integer types so fold won't know that
2842      they are really pointers.  */
2843   fold_defer_overflow_warnings ();
2844
2845   /* If what we are about to multiply by the size of the elements
2846      contains a constant term, apply distributive law
2847      and multiply that constant term separately.
2848      This helps produce common subexpressions.  */
2849   if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
2850       && !TREE_CONSTANT (intop)
2851       && TREE_CONSTANT (TREE_OPERAND (intop, 1))
2852       && TREE_CONSTANT (size_exp)
2853       /* If the constant comes from pointer subtraction,
2854          skip this optimization--it would cause an error.  */
2855       && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
2856       /* If the constant is unsigned, and smaller than the pointer size,
2857          then we must skip this optimization.  This is because it could cause
2858          an overflow error if the constant is negative but INTOP is not.  */
2859       && (!TYPE_UNSIGNED (TREE_TYPE (intop))
2860           || (TYPE_PRECISION (TREE_TYPE (intop))
2861               == TYPE_PRECISION (TREE_TYPE (ptrop)))))
2862     {
2863       enum tree_code subcode = resultcode;
2864       tree int_type = TREE_TYPE (intop);
2865       if (TREE_CODE (intop) == MINUS_EXPR)
2866         subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
2867       /* Convert both subexpression types to the type of intop,
2868          because weird cases involving pointer arithmetic
2869          can result in a sum or difference with different type args.  */
2870       ptrop = build_binary_op (subcode, ptrop,
2871                                convert (int_type, TREE_OPERAND (intop, 1)), 1);
2872       intop = convert (int_type, TREE_OPERAND (intop, 0));
2873     }
2874
2875   /* Convert the integer argument to a type the same size as sizetype
2876      so the multiply won't overflow spuriously.  */
2877   if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype)
2878       || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype))
2879     intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype),
2880                                              TYPE_UNSIGNED (sizetype)), intop);
2881
2882   /* Replace the integer argument with a suitable product by the object size.
2883      Do this multiplication as signed, then convert to the appropriate
2884      type for the pointer operation.  */
2885   intop = convert (sizetype,
2886                    build_binary_op (MULT_EXPR, intop,
2887                                     convert (TREE_TYPE (intop), size_exp), 1));
2888
2889   /* Create the sum or difference.  */
2890   if (resultcode == MINUS_EXPR)
2891     intop = fold_build1 (NEGATE_EXPR, sizetype, intop);
2892
2893   ret = fold_build2 (POINTER_PLUS_EXPR, result_type, ptrop, intop);
2894
2895   fold_undefer_and_ignore_overflow_warnings ();
2896
2897   return ret;
2898 }
2899 \f
2900 /* Return whether EXPR is a declaration whose address can never be
2901    NULL.  */
2902
2903 bool
2904 decl_with_nonnull_addr_p (const_tree expr)
2905 {
2906   return (DECL_P (expr)
2907           && (TREE_CODE (expr) == PARM_DECL
2908               || TREE_CODE (expr) == LABEL_DECL
2909               || !DECL_WEAK (expr)));
2910 }
2911
2912 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
2913    or for an `if' or `while' statement or ?..: exp.  It should already
2914    have been validated to be of suitable type; otherwise, a bad
2915    diagnostic may result.
2916
2917    This preparation consists of taking the ordinary
2918    representation of an expression expr and producing a valid tree
2919    boolean expression describing whether expr is nonzero.  We could
2920    simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1),
2921    but we optimize comparisons, &&, ||, and !.
2922
2923    The resulting type should always be `truthvalue_type_node'.  */
2924
2925 tree
2926 c_common_truthvalue_conversion (tree expr)
2927 {
2928   switch (TREE_CODE (expr))
2929     {
2930     case EQ_EXPR:   case NE_EXPR:   case UNEQ_EXPR: case LTGT_EXPR:
2931     case LE_EXPR:   case GE_EXPR:   case LT_EXPR:   case GT_EXPR:
2932     case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR:
2933     case ORDERED_EXPR: case UNORDERED_EXPR:
2934       if (TREE_TYPE (expr) == truthvalue_type_node)
2935         return expr;
2936       return build2 (TREE_CODE (expr), truthvalue_type_node,
2937                      TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1));
2938
2939     case TRUTH_ANDIF_EXPR:
2940     case TRUTH_ORIF_EXPR:
2941     case TRUTH_AND_EXPR:
2942     case TRUTH_OR_EXPR:
2943     case TRUTH_XOR_EXPR:
2944       if (TREE_TYPE (expr) == truthvalue_type_node)
2945         return expr;
2946       return build2 (TREE_CODE (expr), truthvalue_type_node,
2947                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)),
2948                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)));
2949
2950     case TRUTH_NOT_EXPR:
2951       if (TREE_TYPE (expr) == truthvalue_type_node)
2952         return expr;
2953       return build1 (TREE_CODE (expr), truthvalue_type_node,
2954                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)));
2955
2956     case ERROR_MARK:
2957       return expr;
2958
2959     case INTEGER_CST:
2960       return integer_zerop (expr) ? truthvalue_false_node
2961                                   : truthvalue_true_node;
2962
2963     case REAL_CST:
2964       return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0)
2965              ? truthvalue_true_node
2966              : truthvalue_false_node;
2967
2968     case FIXED_CST:
2969       return fixed_compare (NE_EXPR, &TREE_FIXED_CST (expr),
2970                             &FCONST0 (TYPE_MODE (TREE_TYPE (expr))))
2971              ? truthvalue_true_node
2972              : truthvalue_false_node;
2973
2974     case FUNCTION_DECL:
2975       expr = build_unary_op (ADDR_EXPR, expr, 0);
2976       /* Fall through.  */
2977
2978     case ADDR_EXPR:
2979       {
2980         tree inner = TREE_OPERAND (expr, 0);
2981         if (decl_with_nonnull_addr_p (inner))
2982           {
2983             /* Common Ada/Pascal programmer's mistake.  */
2984             warning (OPT_Waddress,
2985                      "the address of %qD will always evaluate as %<true%>",
2986                      inner);
2987             return truthvalue_true_node;
2988           }
2989
2990         /* If we still have a decl, it is possible for its address to
2991            be NULL, so we cannot optimize.  */
2992         if (DECL_P (inner))
2993           {
2994             gcc_assert (DECL_WEAK (inner));
2995             break;
2996           }
2997
2998         if (TREE_SIDE_EFFECTS (inner))
2999           return build2 (COMPOUND_EXPR, truthvalue_type_node,
3000                          inner, truthvalue_true_node);
3001         else
3002           return truthvalue_true_node;
3003       }
3004
3005     case COMPLEX_EXPR:
3006       return build_binary_op ((TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
3007                                ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
3008                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)),
3009                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
3010                               0);
3011
3012     case NEGATE_EXPR:
3013     case ABS_EXPR:
3014     case FLOAT_EXPR:
3015       /* These don't change whether an object is nonzero or zero.  */
3016       return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
3017
3018     case LROTATE_EXPR:
3019     case RROTATE_EXPR:
3020       /* These don't change whether an object is zero or nonzero, but
3021          we can't ignore them if their second arg has side-effects.  */
3022       if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
3023         return build2 (COMPOUND_EXPR, truthvalue_type_node,
3024                        TREE_OPERAND (expr, 1),
3025                        c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)));
3026       else
3027         return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
3028
3029     case COND_EXPR:
3030       /* Distribute the conversion into the arms of a COND_EXPR.  */
3031       return fold_build3 (COND_EXPR, truthvalue_type_node,
3032                 TREE_OPERAND (expr, 0),
3033                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
3034                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 2)));
3035
3036     case CONVERT_EXPR:
3037     case NOP_EXPR:
3038       /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
3039          since that affects how `default_conversion' will behave.  */
3040       if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
3041           || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
3042         break;
3043       /* If this is widening the argument, we can ignore it.  */
3044       if (TYPE_PRECISION (TREE_TYPE (expr))
3045           >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
3046         return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
3047       break;
3048
3049     case MODIFY_EXPR:
3050       if (!TREE_NO_WARNING (expr)
3051           && warn_parentheses)
3052         {
3053           warning (OPT_Wparentheses,
3054                    "suggest parentheses around assignment used as truth value");
3055           TREE_NO_WARNING (expr) = 1;
3056         }
3057       break;
3058
3059     default:
3060       break;
3061     }
3062
3063   if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
3064     {
3065       tree t = save_expr (expr);
3066       return (build_binary_op
3067               ((TREE_SIDE_EFFECTS (expr)
3068                 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
3069         c_common_truthvalue_conversion (build_unary_op (REALPART_EXPR, t, 0)),
3070         c_common_truthvalue_conversion (build_unary_op (IMAGPART_EXPR, t, 0)),
3071                0));
3072     }
3073
3074   if (TREE_CODE (TREE_TYPE (expr)) == FIXED_POINT_TYPE)
3075     {
3076       tree fixed_zero_node = build_fixed (TREE_TYPE (expr),
3077                                           FCONST0 (TYPE_MODE
3078                                                    (TREE_TYPE (expr))));
3079       return build_binary_op (NE_EXPR, expr, fixed_zero_node, 1);
3080     }
3081
3082   return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3083 }
3084 \f
3085 static void def_builtin_1  (enum built_in_function fncode,
3086                             const char *name,
3087                             enum built_in_class fnclass,
3088                             tree fntype, tree libtype,
3089                             bool both_p, bool fallback_p, bool nonansi_p,
3090                             tree fnattrs, bool implicit_p);
3091
3092
3093 /* Apply the TYPE_QUALS to the new DECL.  */
3094
3095 void
3096 c_apply_type_quals_to_decl (int type_quals, tree decl)
3097 {
3098   tree type = TREE_TYPE (decl);
3099
3100   if (type == error_mark_node)
3101     return;
3102
3103   if (((type_quals & TYPE_QUAL_CONST)
3104        || (type && TREE_CODE (type) == REFERENCE_TYPE))
3105       /* An object declared 'const' is only readonly after it is
3106          initialized.  We don't have any way of expressing this currently,
3107          so we need to be conservative and unset TREE_READONLY for types
3108          with constructors.  Otherwise aliasing code will ignore stores in
3109          an inline constructor.  */
3110       && !(type && TYPE_NEEDS_CONSTRUCTING (type)))
3111     TREE_READONLY (decl) = 1;
3112   if (type_quals & TYPE_QUAL_VOLATILE)
3113     {
3114       TREE_SIDE_EFFECTS (decl) = 1;
3115       TREE_THIS_VOLATILE (decl) = 1;
3116     }
3117   if (type_quals & TYPE_QUAL_RESTRICT)
3118     {
3119       while (type && TREE_CODE (type) == ARRAY_TYPE)
3120         /* Allow 'restrict' on arrays of pointers.
3121            FIXME currently we just ignore it.  */
3122         type = TREE_TYPE (type);
3123       if (!type
3124           || !POINTER_TYPE_P (type)
3125           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))
3126         error ("invalid use of %<restrict%>");
3127       else if (flag_strict_aliasing && type == TREE_TYPE (decl))
3128         /* Indicate we need to make a unique alias set for this pointer.
3129            We can't do it here because it might be pointing to an
3130            incomplete type.  */
3131         DECL_POINTER_ALIAS_SET (decl) = -2;
3132     }
3133 }
3134
3135 /* Hash function for the problem of multiple type definitions in
3136    different files.  This must hash all types that will compare
3137    equal via comptypes to the same value.  In practice it hashes
3138    on some of the simple stuff and leaves the details to comptypes.  */
3139
3140 static hashval_t
3141 c_type_hash (const void *p)
3142 {
3143   int i = 0;
3144   int shift, size;
3145   const_tree const t = (const_tree) p;
3146   tree t2;
3147   switch (TREE_CODE (t))
3148     {
3149     /* For pointers, hash on pointee type plus some swizzling.  */
3150     case POINTER_TYPE:
3151       return c_type_hash (TREE_TYPE (t)) ^ 0x3003003;
3152     /* Hash on number of elements and total size.  */
3153     case ENUMERAL_TYPE:
3154       shift = 3;
3155       t2 = TYPE_VALUES (t);
3156       break;
3157     case RECORD_TYPE:
3158       shift = 0;
3159       t2 = TYPE_FIELDS (t);
3160       break;
3161     case QUAL_UNION_TYPE:
3162       shift = 1;
3163       t2 = TYPE_FIELDS (t);
3164       break;
3165     case UNION_TYPE:
3166       shift = 2;
3167       t2 = TYPE_FIELDS (t);
3168       break;
3169     default:
3170       gcc_unreachable ();
3171     }
3172   for (; t2; t2 = TREE_CHAIN (t2))
3173     i++;
3174   size = TREE_INT_CST_LOW (TYPE_SIZE (t));
3175   return ((size << 24) | (i << shift));
3176 }
3177
3178 static GTY((param_is (union tree_node))) htab_t type_hash_table;
3179
3180 /* Return the typed-based alias set for T, which may be an expression
3181    or a type.  Return -1 if we don't do anything special.  */
3182
3183 alias_set_type
3184 c_common_get_alias_set (tree t)
3185 {
3186   tree u;
3187   PTR *slot;
3188
3189   /* Permit type-punning when accessing a union, provided the access
3190      is directly through the union.  For example, this code does not
3191      permit taking the address of a union member and then storing
3192      through it.  Even the type-punning allowed here is a GCC
3193      extension, albeit a common and useful one; the C standard says
3194      that such accesses have implementation-defined behavior.  */
3195   for (u = t;
3196        TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
3197        u = TREE_OPERAND (u, 0))
3198     if (TREE_CODE (u) == COMPONENT_REF
3199         && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
3200       return 0;
3201
3202   /* That's all the expressions we handle specially.  */
3203   if (!TYPE_P (t))
3204     return -1;
3205
3206   /* The C standard guarantees that any object may be accessed via an
3207      lvalue that has character type.  */
3208   if (t == char_type_node
3209       || t == signed_char_type_node
3210       || t == unsigned_char_type_node)
3211     return 0;
3212
3213   /* If it has the may_alias attribute, it can alias anything.  */
3214   if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (t)))
3215     return 0;
3216
3217   /* The C standard specifically allows aliasing between signed and
3218      unsigned variants of the same type.  We treat the signed
3219      variant as canonical.  */
3220   if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t))
3221     {
3222       tree t1 = c_common_signed_type (t);
3223
3224       /* t1 == t can happen for boolean nodes which are always unsigned.  */
3225       if (t1 != t)
3226         return get_alias_set (t1);
3227     }
3228   else if (POINTER_TYPE_P (t))
3229     {
3230       tree t1;
3231
3232       /* Unfortunately, there is no canonical form of a pointer type.
3233          In particular, if we have `typedef int I', then `int *', and
3234          `I *' are different types.  So, we have to pick a canonical
3235          representative.  We do this below.
3236
3237          Technically, this approach is actually more conservative that
3238          it needs to be.  In particular, `const int *' and `int *'
3239          should be in different alias sets, according to the C and C++
3240          standard, since their types are not the same, and so,
3241          technically, an `int **' and `const int **' cannot point at
3242          the same thing.
3243
3244          But, the standard is wrong.  In particular, this code is
3245          legal C++:
3246
3247             int *ip;
3248             int **ipp = &ip;
3249             const int* const* cipp = ipp;
3250
3251          And, it doesn't make sense for that to be legal unless you
3252          can dereference IPP and CIPP.  So, we ignore cv-qualifiers on
3253          the pointed-to types.  This issue has been reported to the
3254          C++ committee.  */
3255       t1 = build_type_no_quals (t);
3256       if (t1 != t)
3257         return get_alias_set (t1);
3258     }
3259
3260   /* Handle the case of multiple type nodes referring to "the same" type,
3261      which occurs with IMA.  These share an alias set.  FIXME:  Currently only
3262      C90 is handled.  (In C99 type compatibility is not transitive, which
3263      complicates things mightily. The alias set splay trees can theoretically
3264      represent this, but insertion is tricky when you consider all the
3265      different orders things might arrive in.) */
3266
3267   if (c_language != clk_c || flag_isoc99)
3268     return -1;
3269
3270   /* Save time if there's only one input file.  */
3271   if (num_in_fnames == 1)
3272     return -1;
3273
3274   /* Pointers need special handling if they point to any type that
3275      needs special handling (below).  */
3276   if (TREE_CODE (t) == POINTER_TYPE)
3277     {
3278       tree t2;
3279       /* Find bottom type under any nested POINTERs.  */
3280       for (t2 = TREE_TYPE (t);
3281            TREE_CODE (t2) == POINTER_TYPE;
3282            t2 = TREE_TYPE (t2))
3283         ;
3284       if (TREE_CODE (t2) != RECORD_TYPE
3285           && TREE_CODE (t2) != ENUMERAL_TYPE
3286           && TREE_CODE (t2) != QUAL_UNION_TYPE
3287           && TREE_CODE (t2) != UNION_TYPE)
3288         return -1;
3289       if (TYPE_SIZE (t2) == 0)
3290         return -1;
3291     }
3292   /* These are the only cases that need special handling.  */
3293   if (TREE_CODE (t) != RECORD_TYPE
3294       && TREE_CODE (t) != ENUMERAL_TYPE
3295       && TREE_CODE (t) != QUAL_UNION_TYPE
3296       && TREE_CODE (t) != UNION_TYPE
3297       && TREE_CODE (t) != POINTER_TYPE)
3298     return -1;
3299   /* Undefined? */
3300   if (TYPE_SIZE (t) == 0)
3301     return -1;
3302
3303   /* Look up t in hash table.  Only one of the compatible types within each
3304      alias set is recorded in the table.  */
3305   if (!type_hash_table)
3306     type_hash_table = htab_create_ggc (1021, c_type_hash,
3307             (htab_eq) lang_hooks.types_compatible_p,
3308             NULL);
3309   slot = htab_find_slot (type_hash_table, t, INSERT);
3310   if (*slot != NULL)
3311     {
3312       TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot);
3313       return TYPE_ALIAS_SET ((tree)*slot);
3314     }
3315   else
3316     /* Our caller will assign and record (in t) a new alias set; all we need
3317        to do is remember t in the hash table.  */
3318     *slot = t;
3319
3320   return -1;
3321 }
3322 \f
3323 /* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where the
3324    second parameter indicates which OPERATOR is being applied.  The COMPLAIN
3325    flag controls whether we should diagnose possibly ill-formed
3326    constructs or not.  */
3327
3328 tree
3329 c_sizeof_or_alignof_type (tree type, bool is_sizeof, int complain)
3330 {
3331   const char *op_name;
3332   tree value = NULL;
3333   enum tree_code type_code = TREE_CODE (type);
3334
3335   op_name = is_sizeof ? "sizeof" : "__alignof__";
3336
3337   if (type_code == FUNCTION_TYPE)
3338     {
3339       if (is_sizeof)
3340         {
3341           if (complain && (pedantic || warn_pointer_arith))
3342             pedwarn ("invalid application of %<sizeof%> to a function type");
3343           value = size_one_node;
3344         }
3345       else
3346         value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);
3347     }
3348   else if (type_code == VOID_TYPE || type_code == ERROR_MARK)
3349     {
3350       if (type_code == VOID_TYPE
3351           && complain && (pedantic || warn_pointer_arith))
3352         pedwarn ("invalid application of %qs to a void type", op_name);
3353       value = size_one_node;
3354     }
3355   else if (!COMPLETE_TYPE_P (type))
3356     {
3357       if (complain)
3358         error ("invalid application of %qs to incomplete type %qT ",
3359                op_name, type);
3360       value = size_zero_node;
3361     }
3362   else
3363     {
3364       if (is_sizeof)
3365         /* Convert in case a char is more than one unit.  */
3366         value = size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
3367                             size_int (TYPE_PRECISION (char_type_node)
3368                                       / BITS_PER_UNIT));
3369       else
3370         value = size_int (TYPE_ALIGN_UNIT (type));
3371     }
3372
3373   /* VALUE will have an integer type with TYPE_IS_SIZETYPE set.
3374      TYPE_IS_SIZETYPE means that certain things (like overflow) will
3375      never happen.  However, this node should really have type
3376      `size_t', which is just a typedef for an ordinary integer type.  */
3377   value = fold_convert (size_type_node, value);
3378   gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value)));
3379
3380   return value;
3381 }
3382
3383 /* Implement the __alignof keyword: Return the minimum required
3384    alignment of EXPR, measured in bytes.  For VAR_DECLs,
3385    FUNCTION_DECLs and FIELD_DECLs return DECL_ALIGN (which can be set
3386    from an "aligned" __attribute__ specification).  */
3387
3388 tree
3389 c_alignof_expr (tree expr)
3390 {
3391   tree t;
3392
3393   if (VAR_OR_FUNCTION_DECL_P (expr))
3394     t = size_int (DECL_ALIGN_UNIT (expr));
3395
3396   else if (TREE_CODE (expr) == COMPONENT_REF
3397            && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1)))
3398     {
3399       error ("%<__alignof%> applied to a bit-field");
3400       t = size_one_node;
3401     }
3402   else if (TREE_CODE (expr) == COMPONENT_REF
3403            && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL)
3404     t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1)));
3405
3406   else if (TREE_CODE (expr) == INDIRECT_REF)
3407     {
3408       tree t = TREE_OPERAND (expr, 0);
3409       tree best = t;
3410       int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
3411
3412       while ((TREE_CODE (t) == NOP_EXPR || TREE_CODE (t) == CONVERT_EXPR)
3413              && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE)
3414         {
3415           int thisalign;
3416
3417           t = TREE_OPERAND (t, 0);
3418           thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
3419           if (thisalign > bestalign)
3420             best = t, bestalign = thisalign;
3421         }
3422       return c_alignof (TREE_TYPE (TREE_TYPE (best)));
3423     }
3424   else
3425     return c_alignof (TREE_TYPE (expr));
3426
3427   return fold_convert (size_type_node, t);
3428 }
3429 \f
3430 /* Handle C and C++ default attributes.  */
3431
3432 enum built_in_attribute
3433 {
3434 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
3435 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
3436 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
3437 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
3438 #include "builtin-attrs.def"
3439 #undef DEF_ATTR_NULL_TREE
3440 #undef DEF_ATTR_INT
3441 #undef DEF_ATTR_IDENT
3442 #undef DEF_ATTR_TREE_LIST
3443   ATTR_LAST
3444 };
3445
3446 static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
3447
3448 static void c_init_attributes (void);
3449
3450 enum c_builtin_type
3451 {
3452 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
3453 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
3454 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
3455 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
3456 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
3457 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
3458 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
3459 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) NAME,
3460 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7) NAME,
3461 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
3462 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
3463 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
3464 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
3465 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
3466 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \
3467   NAME,
3468 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
3469 #include "builtin-types.def"
3470 #undef DEF_PRIMITIVE_TYPE
3471 #undef DEF_FUNCTION_TYPE_0
3472 #undef DEF_FUNCTION_TYPE_1
3473 #undef DEF_FUNCTION_TYPE_2
3474 #undef DEF_FUNCTION_TYPE_3
3475 #undef DEF_FUNCTION_TYPE_4
3476 #undef DEF_FUNCTION_TYPE_5
3477 #undef DEF_FUNCTION_TYPE_6
3478 #undef DEF_FUNCTION_TYPE_7
3479 #undef DEF_FUNCTION_TYPE_VAR_0
3480 #undef DEF_FUNCTION_TYPE_VAR_1
3481 #undef DEF_FUNCTION_TYPE_VAR_2
3482 #undef DEF_FUNCTION_TYPE_VAR_3
3483 #undef DEF_FUNCTION_TYPE_VAR_4
3484 #undef DEF_FUNCTION_TYPE_VAR_5
3485 #undef DEF_POINTER_TYPE
3486   BT_LAST
3487 };
3488
3489 typedef enum c_builtin_type builtin_type;
3490
3491 /* A temporary array for c_common_nodes_and_builtins.  Used in
3492    communication with def_fn_type.  */
3493 static tree builtin_types[(int) BT_LAST + 1];
3494
3495 /* A helper function for c_common_nodes_and_builtins.  Build function type
3496    for DEF with return type RET and N arguments.  If VAR is true, then the
3497    function should be variadic after those N arguments.
3498
3499    Takes special care not to ICE if any of the types involved are
3500    error_mark_node, which indicates that said type is not in fact available
3501    (see builtin_type_for_size).  In which case the function type as a whole
3502    should be error_mark_node.  */
3503
3504 static void
3505 def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...)
3506 {
3507   tree args = NULL, t;
3508   va_list list;
3509   int i;
3510
3511   va_start (list, n);
3512   for (i = 0; i < n; ++i)
3513     {
3514       builtin_type a = va_arg (list, builtin_type);
3515       t = builtin_types[a];
3516       if (t == error_mark_node)
3517         goto egress;
3518       args = tree_cons (NULL_TREE, t, args);
3519     }
3520   va_end (list);
3521
3522   args = nreverse (args);
3523   if (!var)
3524     args = chainon (args, void_list_node);
3525
3526   t = builtin_types[ret];
3527   if (t == error_mark_node)
3528     goto egress;
3529   t = build_function_type (t, args);
3530
3531  egress:
3532   builtin_types[def] = t;
3533 }
3534
3535 /* Build builtin functions common to both C and C++ language
3536    frontends.  */
3537
3538 static void
3539 c_define_builtins (tree va_list_ref_type_node, tree va_list_arg_type_node)
3540 {
3541 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
3542   builtin_types[ENUM] = VALUE;
3543 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
3544   def_fn_type (ENUM, RETURN, 0, 0);
3545 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
3546   def_fn_type (ENUM, RETURN, 0, 1, ARG1);
3547 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
3548   def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
3549 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
3550   def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
3551 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
3552   def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
3553 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
3554   def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
3555 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
3556                             ARG6)                                       \
3557   def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
3558 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
3559                             ARG6, ARG7)                                 \
3560   def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
3561 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
3562   def_fn_type (ENUM, RETURN, 1, 0);
3563 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
3564   def_fn_type (ENUM, RETURN, 1, 1, ARG1);
3565 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
3566   def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
3567 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
3568   def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
3569 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
3570   def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
3571 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
3572   def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
3573 #define DEF_POINTER_TYPE(ENUM, TYPE) \
3574   builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
3575
3576 #include "builtin-types.def"
3577
3578 #undef DEF_PRIMITIVE_TYPE
3579 #undef DEF_FUNCTION_TYPE_1
3580 #undef DEF_FUNCTION_TYPE_2
3581 #undef DEF_FUNCTION_TYPE_3
3582 #undef DEF_FUNCTION_TYPE_4
3583 #undef DEF_FUNCTION_TYPE_5
3584 #undef DEF_FUNCTION_TYPE_6
3585 #undef DEF_FUNCTION_TYPE_VAR_0
3586 #undef DEF_FUNCTION_TYPE_VAR_1
3587 #undef DEF_FUNCTION_TYPE_VAR_2
3588 #undef DEF_FUNCTION_TYPE_VAR_3
3589 #undef DEF_FUNCTION_TYPE_VAR_4
3590 #undef DEF_FUNCTION_TYPE_VAR_5
3591 #undef DEF_POINTER_TYPE
3592   builtin_types[(int) BT_LAST] = NULL_TREE;
3593
3594   c_init_attributes ();
3595
3596 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
3597                     NONANSI_P, ATTRS, IMPLICIT, COND)                   \
3598   if (NAME && COND)                                                     \
3599     def_builtin_1 (ENUM, NAME, CLASS,                                   \
3600                    builtin_types[(int) TYPE],                           \
3601                    builtin_types[(int) LIBTYPE],                        \
3602                    BOTH_P, FALLBACK_P, NONANSI_P,                       \
3603                    built_in_attributes[(int) ATTRS], IMPLICIT);
3604 #include "builtins.def"
3605 #undef DEF_BUILTIN
3606
3607   targetm.init_builtins ();
3608
3609   build_common_builtin_nodes ();
3610
3611   if (flag_mudflap)
3612     mudflap_init ();
3613 }
3614
3615 /* Build tree nodes and builtin functions common to both C and C++ language
3616    frontends.  */
3617
3618 void
3619 c_common_nodes_and_builtins (void)
3620 {
3621   int wchar_type_size;
3622   tree array_domain_type;
3623   tree va_list_ref_type_node;
3624   tree va_list_arg_type_node;
3625
3626   /* Define `int' and `char' first so that dbx will output them first.  */
3627   record_builtin_type (RID_INT, NULL, integer_type_node);
3628   record_builtin_type (RID_CHAR, "char", char_type_node);
3629
3630   /* `signed' is the same as `int'.  FIXME: the declarations of "signed",
3631      "unsigned long", "long long unsigned" and "unsigned short" were in C++
3632      but not C.  Are the conditionals here needed?  */
3633   if (c_dialect_cxx ())
3634     record_builtin_type (RID_SIGNED, NULL, integer_type_node);
3635   record_builtin_type (RID_LONG, "long int", long_integer_type_node);
3636   record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
3637   record_builtin_type (RID_MAX, "long unsigned int",
3638                        long_unsigned_type_node);
3639   if (c_dialect_cxx ())
3640     record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
3641   record_builtin_type (RID_MAX, "long long int",
3642                        long_long_integer_type_node);
3643   record_builtin_type (RID_MAX, "long long unsigned int",
3644                        long_long_unsigned_type_node);
3645   if (c_dialect_cxx ())
3646     record_builtin_type (RID_MAX, "long long unsigned",
3647                          long_long_unsigned_type_node);
3648   record_builtin_type (RID_SHORT, "short int", short_integer_type_node);
3649   record_builtin_type (RID_MAX, "short unsigned int",
3650                        short_unsigned_type_node);
3651   if (c_dialect_cxx ())
3652     record_builtin_type (RID_MAX, "unsigned short",
3653                          short_unsigned_type_node);
3654
3655   /* Define both `signed char' and `unsigned char'.  */
3656   record_builtin_type (RID_MAX, "signed char", signed_char_type_node);
3657   record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node);
3658
3659   /* These are types that c_common_type_for_size and
3660      c_common_type_for_mode use.  */
3661   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3662                                          intQI_type_node));
3663   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3664                                          intHI_type_node));
3665   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3666                                          intSI_type_node));
3667   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3668                                          intDI_type_node));
3669 #if HOST_BITS_PER_WIDE_INT >= 64
3670   if (targetm.scalar_mode_supported_p (TImode))
3671     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3672                                            get_identifier ("__int128_t"),
3673                                            intTI_type_node));
3674 #endif
3675   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3676                                          unsigned_intQI_type_node));
3677   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3678                                          unsigned_intHI_type_node));
3679   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3680                                          unsigned_intSI_type_node));
3681   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3682                                          unsigned_intDI_type_node));
3683 #if HOST_BITS_PER_WIDE_INT >= 64
3684   if (targetm.scalar_mode_supported_p (TImode))
3685     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3686                                            get_identifier ("__uint128_t"),
3687                                            unsigned_intTI_type_node));
3688 #endif
3689
3690   /* Create the widest literal types.  */
3691   widest_integer_literal_type_node
3692     = make_signed_type (HOST_BITS_PER_WIDE_INT * 2);
3693   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3694                                          widest_integer_literal_type_node));
3695
3696   widest_unsigned_literal_type_node
3697     = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2);
3698   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3699                                          widest_unsigned_literal_type_node));
3700
3701   /* `unsigned long' is the standard type for sizeof.
3702      Note that stddef.h uses `unsigned long',
3703      and this must agree, even if long and int are the same size.  */
3704   size_type_node =
3705     TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE)));
3706   signed_size_type_node = c_common_signed_type (size_type_node);
3707   set_sizetype (size_type_node);
3708
3709   pid_type_node =
3710     TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE)));
3711
3712   build_common_tree_nodes_2 (flag_short_double);
3713
3714   record_builtin_type (RID_FLOAT, NULL, float_type_node);
3715   record_builtin_type (RID_DOUBLE, NULL, double_type_node);
3716   record_builtin_type (RID_MAX, "long double", long_double_type_node);
3717
3718   /* Only supported decimal floating point extension if the target
3719      actually supports underlying modes. */
3720   if (targetm.scalar_mode_supported_p (SDmode)
3721       && targetm.scalar_mode_supported_p (DDmode)
3722       && targetm.scalar_mode_supported_p (TDmode))
3723     {
3724       record_builtin_type (RID_DFLOAT32, NULL, dfloat32_type_node);
3725       record_builtin_type (RID_DFLOAT64, NULL, dfloat64_type_node);
3726       record_builtin_type (RID_DFLOAT128, NULL, dfloat128_type_node);
3727     }
3728
3729   if (targetm.fixed_point_supported_p ())
3730     {
3731       record_builtin_type (RID_MAX, "short _Fract", short_fract_type_node);
3732       record_builtin_type (RID_FRACT, NULL, fract_type_node);
3733       record_builtin_type (RID_MAX, "long _Fract", long_fract_type_node);
3734       record_builtin_type (RID_MAX, "long long _Fract",
3735                            long_long_fract_type_node);
3736       record_builtin_type (RID_MAX, "unsigned short _Fract",
3737                            unsigned_short_fract_type_node);
3738       record_builtin_type (RID_MAX, "unsigned _Fract",
3739                            unsigned_fract_type_node);
3740       record_builtin_type (RID_MAX, "unsigned long _Fract",
3741                            unsigned_long_fract_type_node);
3742       record_builtin_type (RID_MAX, "unsigned long long _Fract",
3743                            unsigned_long_long_fract_type_node);
3744       record_builtin_type (RID_MAX, "_Sat short _Fract",
3745                            sat_short_fract_type_node);
3746       record_builtin_type (RID_MAX, "_Sat _Fract", sat_fract_type_node);
3747       record_builtin_type (RID_MAX, "_Sat long _Fract",
3748                            sat_long_fract_type_node);
3749       record_builtin_type (RID_MAX, "_Sat long long _Fract",
3750                            sat_long_long_fract_type_node);
3751       record_builtin_type (RID_MAX, "_Sat unsigned short _Fract",
3752                            sat_unsigned_short_fract_type_node);
3753       record_builtin_type (RID_MAX, "_Sat unsigned _Fract",
3754                            sat_unsigned_fract_type_node);
3755       record_builtin_type (RID_MAX, "_Sat unsigned long _Fract",
3756                            sat_unsigned_long_fract_type_node);
3757       record_builtin_type (RID_MAX, "_Sat unsigned long long _Fract",
3758                            sat_unsigned_long_long_fract_type_node);
3759       record_builtin_type (RID_MAX, "short _Accum", short_accum_type_node);
3760       record_builtin_type (RID_ACCUM, NULL, accum_type_node);
3761       record_builtin_type (RID_MAX, "long _Accum", long_accum_type_node);
3762       record_builtin_type (RID_MAX, "long long _Accum",
3763                            long_long_accum_type_node);
3764       record_builtin_type (RID_MAX, "unsigned short _Accum",
3765                            unsigned_short_accum_type_node);
3766       record_builtin_type (RID_MAX, "unsigned _Accum",
3767                            unsigned_accum_type_node);
3768       record_builtin_type (RID_MAX, "unsigned long _Accum",
3769                            unsigned_long_accum_type_node);
3770       record_builtin_type (RID_MAX, "unsigned long long _Accum",
3771                            unsigned_long_long_accum_type_node);
3772       record_builtin_type (RID_MAX, "_Sat short _Accum",
3773                            sat_short_accum_type_node);
3774       record_builtin_type (RID_MAX, "_Sat _Accum", sat_accum_type_node);
3775       record_builtin_type (RID_MAX, "_Sat long _Accum",
3776                            sat_long_accum_type_node);
3777       record_builtin_type (RID_MAX, "_Sat long long _Accum",
3778                           sat_long_long_accum_type_node);
3779       record_builtin_type (RID_MAX, "_Sat unsigned short _Accum",
3780                            sat_unsigned_short_accum_type_node);
3781       record_builtin_type (RID_MAX, "_Sat unsigned _Accum",
3782                            sat_unsigned_accum_type_node);
3783       record_builtin_type (RID_MAX, "_Sat unsigned long _Accum",
3784                            sat_unsigned_long_accum_type_node);
3785       record_builtin_type (RID_MAX, "_Sat unsigned long long _Accum",
3786                            sat_unsigned_long_long_accum_type_node);
3787
3788     }
3789
3790   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3791                                          get_identifier ("complex int"),
3792                                          complex_integer_type_node));
3793   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3794                                          get_identifier ("complex float"),
3795                                          complex_float_type_node));
3796   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3797                                          get_identifier ("complex double"),
3798                                          complex_double_type_node));
3799   lang_hooks.decls.pushdecl
3800     (build_decl (TYPE_DECL, get_identifier ("complex long double"),
3801                  complex_long_double_type_node));
3802
3803   if (c_dialect_cxx ())
3804     /* For C++, make fileptr_type_node a distinct void * type until
3805        FILE type is defined.  */
3806     fileptr_type_node = build_variant_type_copy (ptr_type_node);
3807
3808   record_builtin_type (RID_VOID, NULL, void_type_node);
3809
3810   /* Set the TYPE_NAME for any variants that were built before
3811      record_builtin_type gave names to the built-in types. */
3812   {
3813     tree void_name = TYPE_NAME (void_type_node);
3814     TYPE_NAME (void_type_node) = NULL_TREE;
3815     TYPE_NAME (build_qualified_type (void_type_node, TYPE_QUAL_CONST))
3816       = void_name;
3817     TYPE_NAME (void_type_node) = void_name;
3818   }
3819
3820   /* This node must not be shared.  */
3821   void_zero_node = make_node (INTEGER_CST);
3822   TREE_TYPE (void_zero_node) = void_type_node;
3823
3824   void_list_node = build_void_list_node ();
3825
3826   /* Make a type to be the domain of a few array types
3827      whose domains don't really matter.
3828      200 is small enough that it always fits in size_t
3829      and large enough that it can hold most function names for the
3830      initializations of __FUNCTION__ and __PRETTY_FUNCTION__.  */
3831   array_domain_type = build_index_type (size_int (200));
3832
3833   /* Make a type for arrays of characters.
3834      With luck nothing will ever really depend on the length of this
3835      array type.  */
3836   char_array_type_node
3837     = build_array_type (char_type_node, array_domain_type);
3838
3839   /* Likewise for arrays of ints.  */
3840   int_array_type_node
3841     = build_array_type (integer_type_node, array_domain_type);
3842
3843   string_type_node = build_pointer_type (char_type_node);
3844   const_string_type_node
3845     = build_pointer_type (build_qualified_type
3846                           (char_type_node, TYPE_QUAL_CONST));
3847
3848   /* This is special for C++ so functions can be overloaded.  */
3849   wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE);
3850   wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node));
3851   wchar_type_size = TYPE_PRECISION (wchar_type_node);
3852   if (c_dialect_cxx ())
3853     {
3854       if (TYPE_UNSIGNED (wchar_type_node))
3855         wchar_type_node = make_unsigned_type (wchar_type_size);
3856       else
3857         wchar_type_node = make_signed_type (wchar_type_size);
3858       record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node);
3859     }
3860   else
3861     {
3862       signed_wchar_type_node = c_common_signed_type (wchar_type_node);
3863       unsigned_wchar_type_node = c_common_unsigned_type (wchar_type_node);
3864     }
3865
3866   /* This is for wide string constants.  */
3867   wchar_array_type_node
3868     = build_array_type (wchar_type_node, array_domain_type);
3869
3870   wint_type_node =
3871     TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE)));
3872
3873   intmax_type_node =
3874     TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE)));
3875   uintmax_type_node =
3876     TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE)));
3877
3878   default_function_type = build_function_type (integer_type_node, NULL_TREE);
3879   ptrdiff_type_node
3880     = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE)));
3881   unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node);
3882
3883   lang_hooks.decls.pushdecl
3884     (build_decl (TYPE_DECL, get_identifier ("__builtin_va_list"),
3885                  va_list_type_node));
3886
3887   if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
3888     {
3889       va_list_arg_type_node = va_list_ref_type_node =
3890         build_pointer_type (TREE_TYPE (va_list_type_node));
3891     }
3892   else
3893     {
3894       va_list_arg_type_node = va_list_type_node;
3895       va_list_ref_type_node = build_reference_type (va_list_type_node);
3896     }
3897
3898   if (!flag_preprocess_only)
3899     c_define_builtins (va_list_ref_type_node, va_list_arg_type_node);
3900
3901   main_identifier_node = get_identifier ("main");
3902
3903   /* Create the built-in __null node.  It is important that this is
3904      not shared.  */
3905   null_node = make_node (INTEGER_CST);
3906   TREE_TYPE (null_node) = c_common_type_for_size (POINTER_SIZE, 0);
3907
3908   /* Since builtin_types isn't gc'ed, don't export these nodes.  */
3909   memset (builtin_types, 0, sizeof (builtin_types));
3910 }
3911
3912 /* Look up the function in built_in_decls that corresponds to DECL
3913    and set ASMSPEC as its user assembler name.  DECL must be a
3914    function decl that declares a builtin.  */
3915
3916 void
3917 set_builtin_user_assembler_name (tree decl, const char *asmspec)
3918 {
3919   tree builtin;
3920   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
3921               && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
3922               && asmspec != 0);
3923
3924   builtin = built_in_decls [DECL_FUNCTION_CODE (decl)];
3925   set_user_assembler_name (builtin, asmspec);
3926   if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMCPY)
3927     init_block_move_fn (asmspec);
3928   else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMSET)
3929     init_block_clear_fn (asmspec);
3930 }
3931
3932 /* The number of named compound-literals generated thus far.  */
3933 static GTY(()) int compound_literal_number;
3934
3935 /* Set DECL_NAME for DECL, a VAR_DECL for a compound-literal.  */
3936
3937 void
3938 set_compound_literal_name (tree decl)
3939 {
3940   char *name;
3941   ASM_FORMAT_PRIVATE_NAME (name, "__compound_literal",
3942                            compound_literal_number);
3943   compound_literal_number++;
3944   DECL_NAME (decl) = get_identifier (name);
3945 }
3946
3947 tree
3948 build_va_arg (tree expr, tree type)
3949 {
3950   return build1 (VA_ARG_EXPR, type, expr);
3951 }
3952
3953
3954 /* Linked list of disabled built-in functions.  */
3955
3956 typedef struct disabled_builtin
3957 {
3958   const char *name;
3959   struct disabled_builtin *next;
3960 } disabled_builtin;
3961 static disabled_builtin *disabled_builtins = NULL;
3962
3963 static bool builtin_function_disabled_p (const char *);
3964
3965 /* Disable a built-in function specified by -fno-builtin-NAME.  If NAME
3966    begins with "__builtin_", give an error.  */
3967
3968 void
3969 disable_builtin_function (const char *name)
3970 {
3971   if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
3972     error ("cannot disable built-in function %qs", name);
3973   else
3974     {
3975       disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin);
3976       new_disabled_builtin->name = name;
3977       new_disabled_builtin->next = disabled_builtins;
3978       disabled_builtins = new_disabled_builtin;
3979     }
3980 }
3981
3982
3983 /* Return true if the built-in function NAME has been disabled, false
3984    otherwise.  */
3985
3986 static bool
3987 builtin_function_disabled_p (const char *name)
3988 {
3989   disabled_builtin *p;
3990   for (p = disabled_builtins; p != NULL; p = p->next)
3991     {
3992       if (strcmp (name, p->name) == 0)
3993         return true;
3994     }
3995   return false;
3996 }
3997
3998
3999 /* Worker for DEF_BUILTIN.
4000    Possibly define a builtin function with one or two names.
4001    Does not declare a non-__builtin_ function if flag_no_builtin, or if
4002    nonansi_p and flag_no_nonansi_builtin.  */
4003
4004 static void
4005 def_builtin_1 (enum built_in_function fncode,
4006                const char *name,
4007                enum built_in_class fnclass,
4008                tree fntype, tree libtype,
4009                bool both_p, bool fallback_p, bool nonansi_p,
4010                tree fnattrs, bool implicit_p)
4011 {
4012   tree decl;
4013   const char *libname;
4014
4015   if (fntype == error_mark_node)
4016     return;
4017
4018   gcc_assert ((!both_p && !fallback_p)
4019               || !strncmp (name, "__builtin_",
4020                            strlen ("__builtin_")));
4021
4022   libname = name + strlen ("__builtin_");
4023   decl = add_builtin_function (name, fntype, fncode, fnclass,
4024                                (fallback_p ? libname : NULL),
4025                                fnattrs);
4026   if (both_p
4027       && !flag_no_builtin && !builtin_function_disabled_p (libname)
4028       && !(nonansi_p && flag_no_nonansi_builtin))
4029     add_builtin_function (libname, libtype, fncode, fnclass,
4030                           NULL, fnattrs);
4031
4032   built_in_decls[(int) fncode] = decl;
4033   if (implicit_p)
4034     implicit_built_in_decls[(int) fncode] = decl;
4035 }
4036 \f
4037 /* Nonzero if the type T promotes to int.  This is (nearly) the
4038    integral promotions defined in ISO C99 6.3.1.1/2.  */
4039
4040 bool
4041 c_promoting_integer_type_p (const_tree t)
4042 {
4043   switch (TREE_CODE (t))
4044     {
4045     case INTEGER_TYPE:
4046       return (TYPE_MAIN_VARIANT (t) == char_type_node
4047               || TYPE_MAIN_VARIANT (t) == signed_char_type_node
4048               || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node
4049               || TYPE_MAIN_VARIANT (t) == short_integer_type_node
4050               || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node
4051               || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node));
4052
4053     case ENUMERAL_TYPE:
4054       /* ??? Technically all enumerations not larger than an int
4055          promote to an int.  But this is used along code paths
4056          that only want to notice a size change.  */
4057       return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node);
4058
4059     case BOOLEAN_TYPE:
4060       return 1;
4061
4062     default:
4063       return 0;
4064     }
4065 }
4066
4067 /* Return 1 if PARMS specifies a fixed number of parameters
4068    and none of their types is affected by default promotions.  */
4069
4070 int
4071 self_promoting_args_p (const_tree parms)
4072 {
4073   const_tree t;
4074   for (t = parms; t; t = TREE_CHAIN (t))
4075     {
4076       tree type = TREE_VALUE (t);
4077
4078       if (type == error_mark_node)
4079         continue;
4080
4081       if (TREE_CHAIN (t) == 0 && type != void_type_node)
4082         return 0;
4083
4084       if (type == 0)
4085         return 0;
4086
4087       if (TYPE_MAIN_VARIANT (type) == float_type_node)
4088         return 0;
4089
4090       if (c_promoting_integer_type_p (type))
4091         return 0;
4092     }
4093   return 1;
4094 }
4095
4096 /* Recursively examines the array elements of TYPE, until a non-array
4097    element type is found.  */
4098
4099 tree
4100 strip_array_types (tree type)
4101 {
4102   while (TREE_CODE (type) == ARRAY_TYPE)
4103     type = TREE_TYPE (type);
4104
4105   return type;
4106 }
4107
4108 /* Recursively remove any '*' or '&' operator from TYPE.  */
4109 tree
4110 strip_pointer_operator (tree t)
4111 {
4112   while (POINTER_TYPE_P (t))
4113     t = TREE_TYPE (t);
4114   return t;
4115 }
4116
4117 /* Recursively remove pointer or array type from TYPE. */
4118 tree
4119 strip_pointer_or_array_types (tree t)
4120 {
4121   while (TREE_CODE (t) == ARRAY_TYPE || POINTER_TYPE_P (t))
4122     t = TREE_TYPE (t);
4123   return t;
4124 }
4125
4126 /* Used to compare case labels.  K1 and K2 are actually tree nodes
4127    representing case labels, or NULL_TREE for a `default' label.
4128    Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
4129    K2, and 0 if K1 and K2 are equal.  */
4130
4131 int
4132 case_compare (splay_tree_key k1, splay_tree_key k2)
4133 {
4134   /* Consider a NULL key (such as arises with a `default' label) to be
4135      smaller than anything else.  */
4136   if (!k1)
4137     return k2 ? -1 : 0;
4138   else if (!k2)
4139     return k1 ? 1 : 0;
4140
4141   return tree_int_cst_compare ((tree) k1, (tree) k2);
4142 }
4143
4144 /* Process a case label for the range LOW_VALUE ... HIGH_VALUE.  If
4145    LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is
4146    actually a `default' label.  If only HIGH_VALUE is NULL_TREE, then
4147    case label was declared using the usual C/C++ syntax, rather than
4148    the GNU case range extension.  CASES is a tree containing all the
4149    case ranges processed so far; COND is the condition for the
4150    switch-statement itself.  Returns the CASE_LABEL_EXPR created, or
4151    ERROR_MARK_NODE if no CASE_LABEL_EXPR is created.  */
4152
4153 tree
4154 c_add_case_label (splay_tree cases, tree cond, tree orig_type,
4155                   tree low_value, tree high_value)
4156 {
4157   tree type;
4158   tree label;
4159   tree case_label;
4160   splay_tree_node node;
4161
4162   /* Create the LABEL_DECL itself.  */
4163   label = create_artificial_label ();
4164
4165   /* If there was an error processing the switch condition, bail now
4166      before we get more confused.  */
4167   if (!cond || cond == error_mark_node)
4168     goto error_out;
4169
4170   if ((low_value && TREE_TYPE (low_value)
4171        && POINTER_TYPE_P (TREE_TYPE (low_value)))
4172       || (high_value && TREE_TYPE (high_value)
4173           && POINTER_TYPE_P (TREE_TYPE (high_value))))
4174     {
4175       error ("pointers are not permitted as case values");
4176       goto error_out;
4177     }
4178
4179   /* Case ranges are a GNU extension.  */
4180   if (high_value && pedantic)
4181     pedwarn ("range expressions in switch statements are non-standard");
4182
4183   type = TREE_TYPE (cond);
4184   if (low_value)
4185     {
4186       low_value = check_case_value (low_value);
4187       low_value = convert_and_check (type, low_value);
4188       if (low_value == error_mark_node)
4189         goto error_out;
4190     }
4191   if (high_value)
4192     {
4193       high_value = check_case_value (high_value);
4194       high_value = convert_and_check (type, high_value);
4195       if (high_value == error_mark_node)
4196         goto error_out;
4197     }
4198
4199   if (low_value && high_value)
4200     {
4201       /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
4202          really a case range, even though it was written that way.
4203          Remove the HIGH_VALUE to simplify later processing.  */
4204       if (tree_int_cst_equal (low_value, high_value))
4205         high_value = NULL_TREE;
4206       else if (!tree_int_cst_lt (low_value, high_value))
4207         warning (0, "empty range specified");
4208     }
4209
4210   /* See if the case is in range of the type of the original testing
4211      expression.  If both low_value and high_value are out of range,
4212      don't insert the case label and return NULL_TREE.  */
4213   if (low_value
4214       && !check_case_bounds (type, orig_type,
4215                              &low_value, high_value ? &high_value : NULL))
4216     return NULL_TREE;
4217
4218   /* Look up the LOW_VALUE in the table of case labels we already
4219      have.  */
4220   node = splay_tree_lookup (cases, (splay_tree_key) low_value);
4221   /* If there was not an exact match, check for overlapping ranges.
4222      There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
4223      that's a `default' label and the only overlap is an exact match.  */
4224   if (!node && (low_value || high_value))
4225     {
4226       splay_tree_node low_bound;
4227       splay_tree_node high_bound;
4228
4229       /* Even though there wasn't an exact match, there might be an
4230          overlap between this case range and another case range.
4231          Since we've (inductively) not allowed any overlapping case
4232          ranges, we simply need to find the greatest low case label
4233          that is smaller that LOW_VALUE, and the smallest low case
4234          label that is greater than LOW_VALUE.  If there is an overlap
4235          it will occur in one of these two ranges.  */
4236       low_bound = splay_tree_predecessor (cases,
4237                                           (splay_tree_key) low_value);
4238       high_bound = splay_tree_successor (cases,
4239                                          (splay_tree_key) low_value);
4240
4241       /* Check to see if the LOW_BOUND overlaps.  It is smaller than
4242          the LOW_VALUE, so there is no need to check unless the
4243          LOW_BOUND is in fact itself a case range.  */
4244       if (low_bound
4245           && CASE_HIGH ((tree) low_bound->value)
4246           && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
4247                                     low_value) >= 0)
4248         node = low_bound;
4249       /* Check to see if the HIGH_BOUND overlaps.  The low end of that
4250          range is bigger than the low end of the current range, so we
4251          are only interested if the current range is a real range, and
4252          not an ordinary case label.  */
4253       else if (high_bound
4254                && high_value
4255                && (tree_int_cst_compare ((tree) high_bound->key,
4256                                          high_value)
4257                    <= 0))
4258         node = high_bound;
4259     }
4260   /* If there was an overlap, issue an error.  */
4261   if (node)
4262     {
4263       tree duplicate = CASE_LABEL ((tree) node->value);
4264
4265       if (high_value)
4266         {
4267           error ("duplicate (or overlapping) case value");
4268           error ("%Jthis is the first entry overlapping that value", duplicate);
4269         }
4270       else if (low_value)
4271         {
4272           error ("duplicate case value") ;
4273           error ("%Jpreviously used here", duplicate);
4274         }
4275       else
4276         {
4277           error ("multiple default labels in one switch");
4278           error ("%Jthis is the first default label", duplicate);
4279         }
4280       goto error_out;
4281     }
4282
4283   /* Add a CASE_LABEL to the statement-tree.  */
4284   case_label = add_stmt (build_case_label (low_value, high_value, label));
4285   /* Register this case label in the splay tree.  */
4286   splay_tree_insert (cases,
4287                      (splay_tree_key) low_value,
4288                      (splay_tree_value) case_label);
4289
4290   return case_label;
4291
4292  error_out:
4293   /* Add a label so that the back-end doesn't think that the beginning of
4294      the switch is unreachable.  Note that we do not add a case label, as
4295      that just leads to duplicates and thence to failure later on.  */
4296   if (!cases->root)
4297     {
4298       tree t = create_artificial_label ();
4299       add_stmt (build_stmt (LABEL_EXPR, t));
4300     }
4301   return error_mark_node;
4302 }
4303
4304 /* Subroutines of c_do_switch_warnings, called via splay_tree_foreach.
4305    Used to verify that case values match up with enumerator values.  */
4306
4307 static void
4308 match_case_to_enum_1 (tree key, tree type, tree label)
4309 {
4310   char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1];
4311
4312   /* ??? Not working too hard to print the double-word value.
4313      Should perhaps be done with %lwd in the diagnostic routines?  */
4314   if (TREE_INT_CST_HIGH (key) == 0)
4315     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED,
4316               TREE_INT_CST_LOW (key));
4317   else if (!TYPE_UNSIGNED (type)
4318            && TREE_INT_CST_HIGH (key) == -1
4319            && TREE_INT_CST_LOW (key) != 0)
4320     snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED,
4321               -TREE_INT_CST_LOW (key));
4322   else
4323     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX,
4324               TREE_INT_CST_HIGH (key), TREE_INT_CST_LOW (key));
4325
4326   if (TYPE_NAME (type) == 0)
4327     warning (0, "%Jcase value %qs not in enumerated type",
4328              CASE_LABEL (label), buf);
4329   else
4330     warning (0, "%Jcase value %qs not in enumerated type %qT",
4331              CASE_LABEL (label), buf, type);
4332 }
4333
4334 /* Subroutine of c_do_switch_warnings, called via splay_tree_foreach.
4335    Used to verify that case values match up with enumerator values.  */
4336
4337 static int
4338 match_case_to_enum (splay_tree_node node, void *data)
4339 {
4340   tree label = (tree) node->value;
4341   tree type = (tree) data;
4342
4343   /* Skip default case.  */
4344   if (!CASE_LOW (label))
4345     return 0;
4346
4347   /* If CASE_LOW_SEEN is not set, that means CASE_LOW did not appear
4348      when we did our enum->case scan.  Reset our scratch bit after.  */
4349   if (!CASE_LOW_SEEN (label))
4350     match_case_to_enum_1 (CASE_LOW (label), type, label);
4351   else
4352     CASE_LOW_SEEN (label) = 0;
4353
4354   /* If CASE_HIGH is non-null, we have a range.  If CASE_HIGH_SEEN is
4355      not set, that means that CASE_HIGH did not appear when we did our
4356      enum->case scan.  Reset our scratch bit after.  */
4357   if (CASE_HIGH (label))
4358     {
4359       if (!CASE_HIGH_SEEN (label))
4360         match_case_to_enum_1 (CASE_HIGH (label), type, label);
4361       else
4362         CASE_HIGH_SEEN (label) = 0;
4363     }
4364
4365   return 0;
4366 }
4367
4368 /* Handle -Wswitch*.  Called from the front end after parsing the
4369    switch construct.  */
4370 /* ??? Should probably be somewhere generic, since other languages
4371    besides C and C++ would want this.  At the moment, however, C/C++
4372    are the only tree-ssa languages that support enumerations at all,
4373    so the point is moot.  */
4374
4375 void
4376 c_do_switch_warnings (splay_tree cases, location_t switch_location,
4377                       tree type, tree cond)
4378 {
4379   splay_tree_node default_node;
4380   splay_tree_node node;
4381   tree chain;
4382
4383   if (!warn_switch && !warn_switch_enum && !warn_switch_default)
4384     return;
4385
4386   default_node = splay_tree_lookup (cases, (splay_tree_key) NULL);
4387   if (!default_node)
4388     warning (OPT_Wswitch_default, "%Hswitch missing default case",
4389              &switch_location);
4390
4391   /* From here on, we only care about about enumerated types.  */
4392   if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
4393     return;
4394
4395   /* If the switch expression was an enumerated type, check that
4396      exactly all enumeration literals are covered by the cases.
4397      The check is made when -Wswitch was specified and there is no
4398      default case, or when -Wswitch-enum was specified.  */
4399
4400   if (!warn_switch_enum
4401       && !(warn_switch && !default_node))
4402     return;
4403
4404   /* Clearing COND if it is not an integer constant simplifies
4405      the tests inside the loop below.  */
4406   if (TREE_CODE (cond) != INTEGER_CST)
4407     cond = NULL_TREE;
4408
4409   /* The time complexity here is O(N*lg(N)) worst case, but for the
4410       common case of monotonically increasing enumerators, it is
4411       O(N), since the nature of the splay tree will keep the next
4412       element adjacent to the root at all times.  */
4413
4414   for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain))
4415     {
4416       tree value = TREE_VALUE (chain);
4417       node = splay_tree_lookup (cases, (splay_tree_key) value);
4418       if (node)
4419         {
4420           /* Mark the CASE_LOW part of the case entry as seen.  */
4421           tree label = (tree) node->value;
4422           CASE_LOW_SEEN (label) = 1;
4423           continue;
4424         }
4425
4426       /* Even though there wasn't an exact match, there might be a
4427          case range which includes the enumator's value.  */
4428       node = splay_tree_predecessor (cases, (splay_tree_key) value);
4429       if (node && CASE_HIGH ((tree) node->value))
4430         {
4431           tree label = (tree) node->value;
4432           int cmp = tree_int_cst_compare (CASE_HIGH (label), value);
4433           if (cmp >= 0)
4434             {
4435               /* If we match the upper bound exactly, mark the CASE_HIGH
4436                  part of the case entry as seen.  */
4437               if (cmp == 0)
4438                 CASE_HIGH_SEEN (label) = 1;
4439               continue;
4440             }
4441         }
4442
4443       /* We've now determined that this enumerated literal isn't
4444          handled by the case labels of the switch statement.  */
4445
4446       /* If the switch expression is a constant, we only really care
4447          about whether that constant is handled by the switch.  */
4448       if (cond && tree_int_cst_compare (cond, value))
4449         continue;
4450
4451       warning (0, "%Henumeration value %qE not handled in switch",
4452                &switch_location, TREE_PURPOSE (chain));
4453     }
4454
4455   /* Warn if there are case expressions that don't correspond to
4456      enumerators.  This can occur since C and C++ don't enforce
4457      type-checking of assignments to enumeration variables.
4458
4459      The time complexity here is now always O(N) worst case, since
4460      we should have marked both the lower bound and upper bound of
4461      every disjoint case label, with CASE_LOW_SEEN and CASE_HIGH_SEEN
4462      above.  This scan also resets those fields.  */
4463   splay_tree_foreach (cases, match_case_to_enum, type);
4464 }
4465
4466 /* Finish an expression taking the address of LABEL (an
4467    IDENTIFIER_NODE).  Returns an expression for the address.  */
4468
4469 tree
4470 finish_label_address_expr (tree label)
4471 {
4472   tree result;
4473
4474   if (pedantic)
4475     pedwarn ("taking the address of a label is non-standard");
4476
4477   if (label == error_mark_node)
4478     return error_mark_node;
4479
4480   label = lookup_label (label);
4481   if (label == NULL_TREE)
4482     result = null_pointer_node;
4483   else
4484     {
4485       TREE_USED (label) = 1;
4486       result = build1 (ADDR_EXPR, ptr_type_node, label);
4487       /* The current function in not necessarily uninlinable.
4488          Computed gotos are incompatible with inlining, but the value
4489          here could be used only in a diagnostic, for example.  */
4490     }
4491
4492   return result;
4493 }
4494
4495 /* Hook used by expand_expr to expand language-specific tree codes.  */
4496 /* The only things that should go here are bits needed to expand
4497    constant initializers.  Everything else should be handled by the
4498    gimplification routines.  */
4499
4500 rtx
4501 c_expand_expr (tree exp, rtx target, enum machine_mode tmode,
4502                int modifier /* Actually enum_modifier.  */,
4503                rtx *alt_rtl)
4504 {
4505   switch (TREE_CODE (exp))
4506     {
4507     case COMPOUND_LITERAL_EXPR:
4508       {
4509         /* Initialize the anonymous variable declared in the compound
4510            literal, then return the variable.  */
4511         tree decl = COMPOUND_LITERAL_EXPR_DECL (exp);
4512         emit_local_var (decl);
4513         return expand_expr_real (decl, target, tmode, modifier, alt_rtl);
4514       }
4515
4516     default:
4517       gcc_unreachable ();
4518     }
4519 }
4520
4521 /* Hook used by staticp to handle language-specific tree codes.  */
4522
4523 tree
4524 c_staticp (tree exp)
4525 {
4526   return (TREE_CODE (exp) == COMPOUND_LITERAL_EXPR
4527           && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp))
4528           ? exp : NULL);
4529 }
4530 \f
4531
4532 /* Given a boolean expression ARG, return a tree representing an increment
4533    or decrement (as indicated by CODE) of ARG.  The front end must check for
4534    invalid cases (e.g., decrement in C++).  */
4535 tree
4536 boolean_increment (enum tree_code code, tree arg)
4537 {
4538   tree val;
4539   tree true_res = build_int_cst (TREE_TYPE (arg), 1);
4540
4541   arg = stabilize_reference (arg);
4542   switch (code)
4543     {
4544     case PREINCREMENT_EXPR:
4545       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
4546       break;
4547     case POSTINCREMENT_EXPR:
4548       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
4549       arg = save_expr (arg);
4550       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
4551       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
4552       break;
4553     case PREDECREMENT_EXPR:
4554       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
4555                     invert_truthvalue (arg));
4556       break;
4557     case POSTDECREMENT_EXPR:
4558       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
4559                     invert_truthvalue (arg));
4560       arg = save_expr (arg);
4561       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
4562       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
4563       break;
4564     default:
4565       gcc_unreachable ();
4566     }
4567   TREE_SIDE_EFFECTS (val) = 1;
4568   return val;
4569 }
4570 \f
4571 /* Built-in macros for stddef.h, that require macros defined in this
4572    file.  */
4573 void
4574 c_stddef_cpp_builtins(void)
4575 {
4576   builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0);
4577   builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0);
4578   builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0);
4579   builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0);
4580   builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0);
4581   builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0);
4582 }
4583
4584 static void
4585 c_init_attributes (void)
4586 {
4587   /* Fill in the built_in_attributes array.  */
4588 #define DEF_ATTR_NULL_TREE(ENUM)                                \
4589   built_in_attributes[(int) ENUM] = NULL_TREE;
4590 #define DEF_ATTR_INT(ENUM, VALUE)                               \
4591   built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
4592 #define DEF_ATTR_IDENT(ENUM, STRING)                            \
4593   built_in_attributes[(int) ENUM] = get_identifier (STRING);
4594 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
4595   built_in_attributes[(int) ENUM]                       \
4596     = tree_cons (built_in_attributes[(int) PURPOSE],    \
4597                  built_in_attributes[(int) VALUE],      \
4598                  built_in_attributes[(int) CHAIN]);
4599 #include "builtin-attrs.def"
4600 #undef DEF_ATTR_NULL_TREE
4601 #undef DEF_ATTR_INT
4602 #undef DEF_ATTR_IDENT
4603 #undef DEF_ATTR_TREE_LIST
4604 }
4605
4606 /* Attribute handlers common to C front ends.  */
4607
4608 /* Handle a "packed" attribute; arguments as in
4609    struct attribute_spec.handler.  */
4610
4611 static tree
4612 handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4613                          int flags, bool *no_add_attrs)
4614 {
4615   if (TYPE_P (*node))
4616     {
4617       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4618         *node = build_variant_type_copy (*node);
4619       TYPE_PACKED (*node) = 1;
4620     }
4621   else if (TREE_CODE (*node) == FIELD_DECL)
4622     {
4623       if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT)
4624         warning (OPT_Wattributes,
4625                  "%qE attribute ignored for field of type %qT",
4626                  name, TREE_TYPE (*node));
4627       else
4628         DECL_PACKED (*node) = 1;
4629     }
4630   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
4631      used for DECL_REGISTER.  It wouldn't mean anything anyway.
4632      We can't set DECL_PACKED on the type of a TYPE_DECL, because
4633      that changes what the typedef is typing.  */
4634   else
4635     {
4636       warning (OPT_Wattributes, "%qE attribute ignored", name);
4637       *no_add_attrs = true;
4638     }
4639
4640   return NULL_TREE;
4641 }
4642
4643 /* Handle a "nocommon" attribute; arguments as in
4644    struct attribute_spec.handler.  */
4645
4646 static tree
4647 handle_nocommon_attribute (tree *node, tree name,
4648                            tree ARG_UNUSED (args),
4649                            int ARG_UNUSED (flags), bool *no_add_attrs)
4650 {
4651   if (TREE_CODE (*node) == VAR_DECL)
4652     DECL_COMMON (*node) = 0;
4653   else
4654     {
4655       warning (OPT_Wattributes, "%qE attribute ignored", name);
4656       *no_add_attrs = true;
4657     }
4658
4659   return NULL_TREE;
4660 }
4661
4662 /* Handle a "common" attribute; arguments as in
4663    struct attribute_spec.handler.  */
4664
4665 static tree
4666 handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4667                          int ARG_UNUSED (flags), bool *no_add_attrs)
4668 {
4669   if (TREE_CODE (*node) == VAR_DECL)
4670     DECL_COMMON (*node) = 1;
4671   else
4672     {
4673       warning (OPT_Wattributes, "%qE attribute ignored", name);
4674       *no_add_attrs = true;
4675     }
4676
4677   return NULL_TREE;
4678 }
4679
4680 /* Handle a "noreturn" attribute; arguments as in
4681    struct attribute_spec.handler.  */
4682
4683 static tree
4684 handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4685                            int ARG_UNUSED (flags), bool *no_add_attrs)
4686 {
4687   tree type = TREE_TYPE (*node);
4688
4689   /* See FIXME comment in c_common_attribute_table.  */
4690   if (TREE_CODE (*node) == FUNCTION_DECL)
4691     TREE_THIS_VOLATILE (*node) = 1;
4692   else if (TREE_CODE (type) == POINTER_TYPE
4693            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4694     TREE_TYPE (*node)
4695       = build_pointer_type
4696         (build_type_variant (TREE_TYPE (type),
4697                              TYPE_READONLY (TREE_TYPE (type)), 1));
4698   else
4699     {
4700       warning (OPT_Wattributes, "%qE attribute ignored", name);
4701       *no_add_attrs = true;
4702     }
4703
4704   return NULL_TREE;
4705 }
4706
4707 /* Handle a "hot" and attribute; arguments as in
4708    struct attribute_spec.handler.  */
4709
4710 static tree
4711 handle_hot_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4712                           int ARG_UNUSED (flags), bool *no_add_attrs)
4713 {
4714   if (TREE_CODE (*node) == FUNCTION_DECL)
4715     {
4716       if (lookup_attribute ("cold", DECL_ATTRIBUTES (*node)) != NULL)
4717         {
4718           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
4719                    name, "cold");
4720           *no_add_attrs = true;
4721         }
4722       /* Do nothing else, just set the attribute.  We'll get at
4723          it later with lookup_attribute.  */
4724     }
4725   else
4726     {
4727       warning (OPT_Wattributes, "%qE attribute ignored", name);
4728       *no_add_attrs = true;
4729     }
4730
4731   return NULL_TREE;
4732 }
4733 /* Handle a "cold" and attribute; arguments as in
4734    struct attribute_spec.handler.  */
4735
4736 static tree
4737 handle_cold_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4738                        int ARG_UNUSED (flags), bool *no_add_attrs)
4739 {
4740   if (TREE_CODE (*node) == FUNCTION_DECL)
4741     {
4742       if (lookup_attribute ("hot", DECL_ATTRIBUTES (*node)) != NULL)
4743         {
4744           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
4745                    name, "hot");
4746           *no_add_attrs = true;
4747         }
4748       /* Do nothing else, just set the attribute.  We'll get at
4749          it later with lookup_attribute.  */
4750     }
4751   else
4752     {
4753       warning (OPT_Wattributes, "%qE attribute ignored", name);
4754       *no_add_attrs = true;
4755     }
4756
4757   return NULL_TREE;
4758 }
4759
4760 /* Handle a "noinline" attribute; arguments as in
4761    struct attribute_spec.handler.  */
4762
4763 static tree
4764 handle_noinline_attribute (tree *node, tree name,
4765                            tree ARG_UNUSED (args),
4766                            int ARG_UNUSED (flags), bool *no_add_attrs)
4767 {
4768   if (TREE_CODE (*node) == FUNCTION_DECL)
4769     DECL_UNINLINABLE (*node) = 1;
4770   else
4771     {
4772       warning (OPT_Wattributes, "%qE attribute ignored", name);
4773       *no_add_attrs = true;
4774     }
4775
4776   return NULL_TREE;
4777 }
4778
4779 /* Handle a "always_inline" attribute; arguments as in
4780    struct attribute_spec.handler.  */
4781
4782 static tree
4783 handle_always_inline_attribute (tree *node, tree name,
4784                                 tree ARG_UNUSED (args),
4785                                 int ARG_UNUSED (flags),
4786                                 bool *no_add_attrs)
4787 {
4788   if (TREE_CODE (*node) == FUNCTION_DECL)
4789     {
4790       /* Set the attribute and mark it for disregarding inline
4791          limits.  */
4792       DECL_DISREGARD_INLINE_LIMITS (*node) = 1;
4793     }
4794   else
4795     {
4796       warning (OPT_Wattributes, "%qE attribute ignored", name);
4797       *no_add_attrs = true;
4798     }
4799
4800   return NULL_TREE;
4801 }
4802
4803 /* Handle a "gnu_inline" attribute; arguments as in
4804    struct attribute_spec.handler.  */
4805
4806 static tree
4807 handle_gnu_inline_attribute (tree *node, tree name,
4808                              tree ARG_UNUSED (args),
4809                              int ARG_UNUSED (flags),
4810                              bool *no_add_attrs)
4811 {
4812   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
4813     {
4814       /* Do nothing else, just set the attribute.  We'll get at
4815          it later with lookup_attribute.  */
4816     }
4817   else
4818     {
4819       warning (OPT_Wattributes, "%qE attribute ignored", name);
4820       *no_add_attrs = true;
4821     }
4822
4823   return NULL_TREE;
4824 }
4825
4826 /* Handle an "artificial" attribute; arguments as in
4827    struct attribute_spec.handler.  */
4828
4829 static tree
4830 handle_artificial_attribute (tree *node, tree name,
4831                              tree ARG_UNUSED (args),
4832                              int ARG_UNUSED (flags),
4833                              bool *no_add_attrs)
4834 {
4835   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
4836     {
4837       /* Do nothing else, just set the attribute.  We'll get at
4838          it later with lookup_attribute.  */
4839     }
4840   else
4841     {
4842       warning (OPT_Wattributes, "%qE attribute ignored", name);
4843       *no_add_attrs = true;
4844     }
4845
4846   return NULL_TREE;
4847 }
4848
4849 /* Handle a "flatten" attribute; arguments as in
4850    struct attribute_spec.handler.  */
4851
4852 static tree
4853 handle_flatten_attribute (tree *node, tree name,
4854                           tree args ATTRIBUTE_UNUSED,
4855                           int flags ATTRIBUTE_UNUSED, bool *no_add_attrs)
4856 {
4857   if (TREE_CODE (*node) == FUNCTION_DECL)
4858     /* Do nothing else, just set the attribute.  We'll get at
4859        it later with lookup_attribute.  */
4860     ;
4861   else
4862     {
4863       warning (OPT_Wattributes, "%qE attribute ignored", name);
4864       *no_add_attrs = true;
4865     }
4866
4867   return NULL_TREE;
4868 }
4869
4870 /* Handle a "warning" or "error" attribute; arguments as in
4871    struct attribute_spec.handler.  */
4872
4873 static tree
4874 handle_error_attribute (tree *node, tree name, tree args,
4875                         int ARG_UNUSED (flags), bool *no_add_attrs)
4876 {
4877   if (TREE_CODE (*node) == FUNCTION_DECL
4878       || TREE_CODE (TREE_VALUE (args)) == STRING_CST)
4879     /* Do nothing else, just set the attribute.  We'll get at
4880        it later with lookup_attribute.  */
4881     ;
4882   else
4883     {
4884       warning (OPT_Wattributes, "%qE attribute ignored", name);
4885       *no_add_attrs = true;
4886     }
4887
4888   return NULL_TREE;
4889 }
4890
4891 /* Handle a "used" attribute; arguments as in
4892    struct attribute_spec.handler.  */
4893
4894 static tree
4895 handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
4896                        int ARG_UNUSED (flags), bool *no_add_attrs)
4897 {
4898   tree node = *pnode;
4899
4900   if (TREE_CODE (node) == FUNCTION_DECL
4901       || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node)))
4902     {
4903       TREE_USED (node) = 1;
4904       DECL_PRESERVE_P (node) = 1;
4905     }
4906   else
4907     {
4908       warning (OPT_Wattributes, "%qE attribute ignored", name);
4909       *no_add_attrs = true;
4910     }
4911
4912   return NULL_TREE;
4913 }
4914
4915 /* Handle a "unused" attribute; arguments as in
4916    struct attribute_spec.handler.  */
4917
4918 static tree
4919 handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4920                          int flags, bool *no_add_attrs)
4921 {
4922   if (DECL_P (*node))
4923     {
4924       tree decl = *node;
4925
4926       if (TREE_CODE (decl) == PARM_DECL
4927           || TREE_CODE (decl) == VAR_DECL
4928           || TREE_CODE (decl) == FUNCTION_DECL
4929           || TREE_CODE (decl) == LABEL_DECL
4930           || TREE_CODE (decl) == TYPE_DECL)
4931         TREE_USED (decl) = 1;
4932       else
4933         {
4934           warning (OPT_Wattributes, "%qE attribute ignored", name);
4935           *no_add_attrs = true;
4936         }
4937     }
4938   else
4939     {
4940       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4941         *node = build_variant_type_copy (*node);
4942       TREE_USED (*node) = 1;
4943     }
4944
4945   return NULL_TREE;
4946 }
4947
4948 /* Handle a "externally_visible" attribute; arguments as in
4949    struct attribute_spec.handler.  */
4950
4951 static tree
4952 handle_externally_visible_attribute (tree *pnode, tree name,
4953                                      tree ARG_UNUSED (args),
4954                                      int ARG_UNUSED (flags),
4955                                      bool *no_add_attrs)
4956 {
4957   tree node = *pnode;
4958
4959   if (TREE_CODE (node) == FUNCTION_DECL || TREE_CODE (node) == VAR_DECL)
4960     {
4961       if ((!TREE_STATIC (node) && TREE_CODE (node) != FUNCTION_DECL
4962            && !DECL_EXTERNAL (node)) || !TREE_PUBLIC (node))
4963         {
4964           warning (OPT_Wattributes,
4965                    "%qE attribute have effect only on public objects", name);
4966           *no_add_attrs = true;
4967         }
4968     }
4969   else
4970     {
4971       warning (OPT_Wattributes, "%qE attribute ignored", name);
4972       *no_add_attrs = true;
4973     }
4974
4975   return NULL_TREE;
4976 }
4977
4978 /* Handle a "const" attribute; arguments as in
4979    struct attribute_spec.handler.  */
4980
4981 static tree
4982 handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4983                         int ARG_UNUSED (flags), bool *no_add_attrs)
4984 {
4985   tree type = TREE_TYPE (*node);
4986
4987   /* See FIXME comment on noreturn in c_common_attribute_table.  */
4988   if (TREE_CODE (*node) == FUNCTION_DECL)
4989     TREE_READONLY (*node) = 1;
4990   else if (TREE_CODE (type) == POINTER_TYPE
4991            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4992     TREE_TYPE (*node)
4993       = build_pointer_type
4994         (build_type_variant (TREE_TYPE (type), 1,
4995                              TREE_THIS_VOLATILE (TREE_TYPE (type))));
4996   else
4997     {
4998       warning (OPT_Wattributes, "%qE attribute ignored", name);
4999       *no_add_attrs = true;
5000     }
5001
5002   return NULL_TREE;
5003 }
5004
5005 /* Handle a "transparent_union" attribute; arguments as in
5006    struct attribute_spec.handler.  */
5007
5008 static tree
5009 handle_transparent_union_attribute (tree *node, tree name,
5010                                     tree ARG_UNUSED (args), int flags,
5011                                     bool *no_add_attrs)
5012 {
5013   tree type;
5014
5015   *no_add_attrs = true;
5016
5017   if (TREE_CODE (*node) == TYPE_DECL)
5018     node = &TREE_TYPE (*node);
5019   type = *node;
5020
5021   if (TREE_CODE (type) == UNION_TYPE)
5022     {
5023       /* When IN_PLACE is set, leave the check for FIELDS and MODE to
5024          the code in finish_struct.  */
5025       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5026         {
5027           if (TYPE_FIELDS (type) == NULL_TREE
5028               || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type)))
5029             goto ignored;
5030
5031           /* A type variant isn't good enough, since we don't a cast
5032              to such a type removed as a no-op.  */
5033           *node = type = build_duplicate_type (type);
5034         }
5035
5036       TYPE_TRANSPARENT_UNION (type) = 1;
5037       return NULL_TREE;
5038     }
5039
5040  ignored:
5041   warning (OPT_Wattributes, "%qE attribute ignored", name);
5042   return NULL_TREE;
5043 }
5044
5045 /* Subroutine of handle_{con,de}structor_attribute.  Evaluate ARGS to
5046    get the requested priority for a constructor or destructor,
5047    possibly issuing diagnostics for invalid or reserved
5048    priorities.  */
5049
5050 static priority_type
5051 get_priority (tree args, bool is_destructor)
5052 {
5053   HOST_WIDE_INT pri;
5054   tree arg;
5055
5056   if (!args)
5057     return DEFAULT_INIT_PRIORITY;
5058
5059   if (!SUPPORTS_INIT_PRIORITY)
5060     {
5061       if (is_destructor)
5062         error ("destructor priorities are not supported");
5063       else
5064         error ("constructor priorities are not supported");
5065       return DEFAULT_INIT_PRIORITY;
5066     }
5067
5068   arg = TREE_VALUE (args);
5069   if (!host_integerp (arg, /*pos=*/0)
5070       || !INTEGRAL_TYPE_P (TREE_TYPE (arg)))
5071     goto invalid;
5072
5073   pri = tree_low_cst (TREE_VALUE (args), /*pos=*/0);
5074   if (pri < 0 || pri > MAX_INIT_PRIORITY)
5075     goto invalid;
5076
5077   if (pri <= MAX_RESERVED_INIT_PRIORITY)
5078     {
5079       if (is_destructor)
5080         warning (0,
5081                  "destructor priorities from 0 to %d are reserved "
5082                  "for the implementation",
5083                  MAX_RESERVED_INIT_PRIORITY);
5084       else
5085         warning (0,
5086                  "constructor priorities from 0 to %d are reserved "
5087                  "for the implementation",
5088                  MAX_RESERVED_INIT_PRIORITY);
5089     }
5090   return pri;
5091
5092  invalid:
5093   if (is_destructor)
5094     error ("destructor priorities must be integers from 0 to %d inclusive",
5095            MAX_INIT_PRIORITY);
5096   else
5097     error ("constructor priorities must be integers from 0 to %d inclusive",
5098            MAX_INIT_PRIORITY);
5099   return DEFAULT_INIT_PRIORITY;
5100 }
5101
5102 /* Handle a "constructor" attribute; arguments as in
5103    struct attribute_spec.handler.  */
5104
5105 static tree
5106 handle_constructor_attribute (tree *node, tree name, tree args,
5107                               int ARG_UNUSED (flags),
5108                               bool *no_add_attrs)
5109 {
5110   tree decl = *node;
5111   tree type = TREE_TYPE (decl);
5112
5113   if (TREE_CODE (decl) == FUNCTION_DECL
5114       && TREE_CODE (type) == FUNCTION_TYPE
5115       && decl_function_context (decl) == 0)
5116     {
5117       priority_type priority;
5118       DECL_STATIC_CONSTRUCTOR (decl) = 1;
5119       priority = get_priority (args, /*is_destructor=*/false);
5120       SET_DECL_INIT_PRIORITY (decl, priority);
5121       TREE_USED (decl) = 1;
5122     }
5123   else
5124     {
5125       warning (OPT_Wattributes, "%qE attribute ignored", name);
5126       *no_add_attrs = true;
5127     }
5128
5129   return NULL_TREE;
5130 }
5131
5132 /* Handle a "destructor" attribute; arguments as in
5133    struct attribute_spec.handler.  */
5134
5135 static tree
5136 handle_destructor_attribute (tree *node, tree name, tree args,
5137                              int ARG_UNUSED (flags),
5138                              bool *no_add_attrs)
5139 {
5140   tree decl = *node;
5141   tree type = TREE_TYPE (decl);
5142
5143   if (TREE_CODE (decl) == FUNCTION_DECL
5144       && TREE_CODE (type) == FUNCTION_TYPE
5145       && decl_function_context (decl) == 0)
5146     {
5147       priority_type priority;
5148       DECL_STATIC_DESTRUCTOR (decl) = 1;
5149       priority = get_priority (args, /*is_destructor=*/true);
5150       SET_DECL_FINI_PRIORITY (decl, priority);
5151       TREE_USED (decl) = 1;
5152     }
5153   else
5154     {
5155       warning (OPT_Wattributes, "%qE attribute ignored", name);
5156       *no_add_attrs = true;
5157     }
5158
5159   return NULL_TREE;
5160 }
5161
5162 /* Handle a "mode" attribute; arguments as in
5163    struct attribute_spec.handler.  */
5164
5165 static tree
5166 handle_mode_attribute (tree *node, tree name, tree args,
5167                        int ARG_UNUSED (flags), bool *no_add_attrs)
5168 {
5169   tree type = *node;
5170
5171   *no_add_attrs = true;
5172
5173   if (TREE_CODE (TREE_VALUE (args)) != IDENTIFIER_NODE)
5174     warning (OPT_Wattributes, "%qE attribute ignored", name);
5175   else
5176     {
5177       int j;
5178       const char *p = IDENTIFIER_POINTER (TREE_VALUE (args));
5179       int len = strlen (p);
5180       enum machine_mode mode = VOIDmode;
5181       tree typefm;
5182       bool valid_mode;
5183
5184       if (len > 4 && p[0] == '_' && p[1] == '_'
5185           && p[len - 1] == '_' && p[len - 2] == '_')
5186         {
5187           char *newp = (char *) alloca (len - 1);
5188
5189           strcpy (newp, &p[2]);
5190           newp[len - 4] = '\0';
5191           p = newp;
5192         }
5193
5194       /* Change this type to have a type with the specified mode.
5195          First check for the special modes.  */
5196       if (!strcmp (p, "byte"))
5197         mode = byte_mode;
5198       else if (!strcmp (p, "word"))
5199         mode = word_mode;
5200       else if (!strcmp (p, "pointer"))
5201         mode = ptr_mode;
5202       else if (!strcmp (p, "libgcc_cmp_return"))
5203         mode = targetm.libgcc_cmp_return_mode ();
5204       else if (!strcmp (p, "libgcc_shift_count"))
5205         mode = targetm.libgcc_shift_count_mode ();
5206       else
5207         for (j = 0; j < NUM_MACHINE_MODES; j++)
5208           if (!strcmp (p, GET_MODE_NAME (j)))
5209             {
5210               mode = (enum machine_mode) j;
5211               break;
5212             }
5213
5214       if (mode == VOIDmode)
5215         {
5216           error ("unknown machine mode %qs", p);
5217           return NULL_TREE;
5218         }
5219
5220       valid_mode = false;
5221       switch (GET_MODE_CLASS (mode))
5222         {
5223         case MODE_INT:
5224         case MODE_PARTIAL_INT:
5225         case MODE_FLOAT:
5226         case MODE_DECIMAL_FLOAT:
5227         case MODE_FRACT:
5228         case MODE_UFRACT:
5229         case MODE_ACCUM:
5230         case MODE_UACCUM:
5231           valid_mode = targetm.scalar_mode_supported_p (mode);
5232           break;
5233
5234         case MODE_COMPLEX_INT:
5235         case MODE_COMPLEX_FLOAT:
5236           valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode));
5237           break;
5238
5239         case MODE_VECTOR_INT:
5240         case MODE_VECTOR_FLOAT:
5241         case MODE_VECTOR_FRACT:
5242         case MODE_VECTOR_UFRACT:
5243         case MODE_VECTOR_ACCUM:
5244         case MODE_VECTOR_UACCUM:
5245           warning (OPT_Wattributes, "specifying vector types with "
5246                    "__attribute__ ((mode)) is deprecated");
5247           warning (OPT_Wattributes,
5248                    "use __attribute__ ((vector_size)) instead");
5249           valid_mode = vector_mode_valid_p (mode);
5250           break;
5251
5252         default:
5253           break;
5254         }
5255       if (!valid_mode)
5256         {
5257           error ("unable to emulate %qs", p);
5258           return NULL_TREE;
5259         }
5260
5261       if (POINTER_TYPE_P (type))
5262         {
5263           tree (*fn)(tree, enum machine_mode, bool);
5264
5265           if (!targetm.valid_pointer_mode (mode))
5266             {
5267               error ("invalid pointer mode %qs", p);
5268               return NULL_TREE;
5269             }
5270
5271           if (TREE_CODE (type) == POINTER_TYPE)
5272             fn = build_pointer_type_for_mode;
5273           else
5274             fn = build_reference_type_for_mode;
5275           typefm = fn (TREE_TYPE (type), mode, false);
5276         }
5277       else
5278         {
5279           /* For fixed-point modes, we need to test if the signness of type
5280              and the machine mode are consistent.  */
5281           if (ALL_FIXED_POINT_MODE_P (mode)
5282               && TYPE_UNSIGNED (type) != UNSIGNED_FIXED_POINT_MODE_P (mode))
5283             {
5284               error ("signness of type and machine mode %qs don't match", p);
5285               return NULL_TREE;
5286             }
5287           /* For fixed-point modes, we need to pass saturating info.  */
5288           typefm = lang_hooks.types.type_for_mode (mode,
5289                         ALL_FIXED_POINT_MODE_P (mode) ? TYPE_SATURATING (type)
5290                                                       : TYPE_UNSIGNED (type));
5291         }
5292
5293       if (typefm == NULL_TREE)
5294         {
5295           error ("no data type for mode %qs", p);
5296           return NULL_TREE;
5297         }
5298       else if (TREE_CODE (type) == ENUMERAL_TYPE)
5299         {
5300           /* For enumeral types, copy the precision from the integer
5301              type returned above.  If not an INTEGER_TYPE, we can't use
5302              this mode for this type.  */
5303           if (TREE_CODE (typefm) != INTEGER_TYPE)
5304             {
5305               error ("cannot use mode %qs for enumeral types", p);
5306               return NULL_TREE;
5307             }
5308
5309           if (flags & ATTR_FLAG_TYPE_IN_PLACE)
5310             {
5311               TYPE_PRECISION (type) = TYPE_PRECISION (typefm);
5312               typefm = type;
5313             }
5314           else
5315             {
5316               /* We cannot build a type variant, as there's code that assumes
5317                  that TYPE_MAIN_VARIANT has the same mode.  This includes the
5318                  debug generators.  Instead, create a subrange type.  This
5319                  results in all of the enumeral values being emitted only once
5320                  in the original, and the subtype gets them by reference.  */
5321               if (TYPE_UNSIGNED (type))
5322                 typefm = make_unsigned_type (TYPE_PRECISION (typefm));
5323               else
5324                 typefm = make_signed_type (TYPE_PRECISION (typefm));
5325               TREE_TYPE (typefm) = type;
5326             }
5327         }
5328       else if (VECTOR_MODE_P (mode)
5329                ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm))
5330                : TREE_CODE (type) != TREE_CODE (typefm))
5331         {
5332           error ("mode %qs applied to inappropriate type", p);
5333           return NULL_TREE;
5334         }
5335
5336       *node = typefm;
5337     }
5338
5339   return NULL_TREE;
5340 }
5341
5342 /* Handle a "section" attribute; arguments as in
5343    struct attribute_spec.handler.  */
5344
5345 static tree
5346 handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5347                           int ARG_UNUSED (flags), bool *no_add_attrs)
5348 {
5349   tree decl = *node;
5350
5351   if (targetm.have_named_sections)
5352     {
5353       user_defined_section_attribute = true;
5354
5355       if ((TREE_CODE (decl) == FUNCTION_DECL
5356            || TREE_CODE (decl) == VAR_DECL)
5357           && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
5358         {
5359           if (TREE_CODE (decl) == VAR_DECL
5360               && current_function_decl != NULL_TREE
5361               && !TREE_STATIC (decl))
5362             {
5363               error ("%Jsection attribute cannot be specified for "
5364                      "local variables", decl);
5365               *no_add_attrs = true;
5366             }
5367
5368           /* The decl may have already been given a section attribute
5369              from a previous declaration.  Ensure they match.  */
5370           else if (DECL_SECTION_NAME (decl) != NULL_TREE
5371                    && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
5372                               TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
5373             {
5374               error ("section of %q+D conflicts with previous declaration",
5375                      *node);
5376               *no_add_attrs = true;
5377             }
5378           else
5379             DECL_SECTION_NAME (decl) = TREE_VALUE (args);
5380         }
5381       else
5382         {
5383           error ("section attribute not allowed for %q+D", *node);
5384           *no_add_attrs = true;
5385         }
5386     }
5387   else
5388     {
5389       error ("%Jsection attributes are not supported for this target", *node);
5390       *no_add_attrs = true;
5391     }
5392
5393   return NULL_TREE;
5394 }
5395
5396 /* Handle a "aligned" attribute; arguments as in
5397    struct attribute_spec.handler.  */
5398
5399 static tree
5400 handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5401                           int flags, bool *no_add_attrs)
5402 {
5403   tree decl = NULL_TREE;
5404   tree *type = NULL;
5405   int is_type = 0;
5406   tree align_expr = (args ? TREE_VALUE (args)
5407                      : size_int (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
5408   int i;
5409
5410   if (DECL_P (*node))
5411     {
5412       decl = *node;
5413       type = &TREE_TYPE (decl);
5414       is_type = TREE_CODE (*node) == TYPE_DECL;
5415     }
5416   else if (TYPE_P (*node))
5417     type = node, is_type = 1;
5418
5419   if (TREE_CODE (align_expr) != INTEGER_CST)
5420     {
5421       error ("requested alignment is not a constant");
5422       *no_add_attrs = true;
5423     }
5424   else if ((i = tree_log2 (align_expr)) == -1)
5425     {
5426       error ("requested alignment is not a power of 2");
5427       *no_add_attrs = true;
5428     }
5429   else if (i > HOST_BITS_PER_INT - 2)
5430     {
5431       error ("requested alignment is too large");
5432       *no_add_attrs = true;
5433     }
5434   else if (is_type)
5435     {
5436       /* If we have a TYPE_DECL, then copy the type, so that we
5437          don't accidentally modify a builtin type.  See pushdecl.  */
5438       if (decl && TREE_TYPE (decl) != error_mark_node
5439           && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
5440         {
5441           tree tt = TREE_TYPE (decl);
5442           *type = build_variant_type_copy (*type);
5443           DECL_ORIGINAL_TYPE (decl) = tt;
5444           TYPE_NAME (*type) = decl;
5445           TREE_USED (*type) = TREE_USED (decl);
5446           TREE_TYPE (decl) = *type;
5447         }
5448       else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5449         *type = build_variant_type_copy (*type);
5450
5451       TYPE_ALIGN (*type) = (1 << i) * BITS_PER_UNIT;
5452       TYPE_USER_ALIGN (*type) = 1;
5453     }
5454   else if (! VAR_OR_FUNCTION_DECL_P (decl)
5455            && TREE_CODE (decl) != FIELD_DECL)
5456     {
5457       error ("alignment may not be specified for %q+D", decl);
5458       *no_add_attrs = true;
5459     }
5460   else if (TREE_CODE (decl) == FUNCTION_DECL
5461            && DECL_ALIGN (decl) > (1 << i) * BITS_PER_UNIT)
5462     {
5463       if (DECL_USER_ALIGN (decl))
5464         error ("alignment for %q+D was previously specified as %d "
5465                "and may not be decreased", decl,
5466                DECL_ALIGN (decl) / BITS_PER_UNIT);
5467       else
5468         error ("alignment for %q+D must be at least %d", decl,
5469                DECL_ALIGN (decl) / BITS_PER_UNIT);
5470       *no_add_attrs = true;
5471     }
5472   else
5473     {
5474       DECL_ALIGN (decl) = (1 << i) * BITS_PER_UNIT;
5475       DECL_USER_ALIGN (decl) = 1;
5476     }
5477
5478   return NULL_TREE;
5479 }
5480
5481 /* Handle a "weak" attribute; arguments as in
5482    struct attribute_spec.handler.  */
5483
5484 static tree
5485 handle_weak_attribute (tree *node, tree name,
5486                        tree ARG_UNUSED (args),
5487                        int ARG_UNUSED (flags),
5488                        bool * ARG_UNUSED (no_add_attrs))
5489 {
5490   if (TREE_CODE (*node) == FUNCTION_DECL
5491       || TREE_CODE (*node) == VAR_DECL)
5492     declare_weak (*node);
5493   else
5494     warning (OPT_Wattributes, "%qE attribute ignored", name);
5495
5496
5497   return NULL_TREE;
5498 }
5499
5500 /* Handle an "alias" attribute; arguments as in
5501    struct attribute_spec.handler.  */
5502
5503 static tree
5504 handle_alias_attribute (tree *node, tree name, tree args,
5505                         int ARG_UNUSED (flags), bool *no_add_attrs)
5506 {
5507   tree decl = *node;
5508
5509   if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
5510       || (TREE_CODE (decl) != FUNCTION_DECL
5511           && TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl))
5512       /* A static variable declaration is always a tentative definition,
5513          but the alias is a non-tentative definition which overrides.  */
5514       || (TREE_CODE (decl) != FUNCTION_DECL
5515           && ! TREE_PUBLIC (decl) && DECL_INITIAL (decl)))
5516     {
5517       error ("%q+D defined both normally and as an alias", decl);
5518       *no_add_attrs = true;
5519     }
5520
5521   /* Note that the very first time we process a nested declaration,
5522      decl_function_context will not be set.  Indeed, *would* never
5523      be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that
5524      we do below.  After such frobbery, pushdecl would set the context.
5525      In any case, this is never what we want.  */
5526   else if (decl_function_context (decl) == 0 && current_function_decl == NULL)
5527     {
5528       tree id;
5529
5530       id = TREE_VALUE (args);
5531       if (TREE_CODE (id) != STRING_CST)
5532         {
5533           error ("alias argument not a string");
5534           *no_add_attrs = true;
5535           return NULL_TREE;
5536         }
5537       id = get_identifier (TREE_STRING_POINTER (id));
5538       /* This counts as a use of the object pointed to.  */
5539       TREE_USED (id) = 1;
5540
5541       if (TREE_CODE (decl) == FUNCTION_DECL)
5542         DECL_INITIAL (decl) = error_mark_node;
5543       else
5544         {
5545           if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5546             DECL_EXTERNAL (decl) = 1;
5547           else
5548             DECL_EXTERNAL (decl) = 0;
5549           TREE_STATIC (decl) = 1;
5550         }
5551     }
5552   else
5553     {
5554       warning (OPT_Wattributes, "%qE attribute ignored", name);
5555       *no_add_attrs = true;
5556     }
5557
5558   return NULL_TREE;
5559 }
5560
5561 /* Handle a "weakref" attribute; arguments as in struct
5562    attribute_spec.handler.  */
5563
5564 static tree
5565 handle_weakref_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5566                           int flags, bool *no_add_attrs)
5567 {
5568   tree attr = NULL_TREE;
5569
5570   /* We must ignore the attribute when it is associated with
5571      local-scoped decls, since attribute alias is ignored and many
5572      such symbols do not even have a DECL_WEAK field.  */
5573   if (decl_function_context (*node) || current_function_decl)
5574     {
5575       warning (OPT_Wattributes, "%qE attribute ignored", name);
5576       *no_add_attrs = true;
5577       return NULL_TREE;
5578     }
5579
5580   /* The idea here is that `weakref("name")' mutates into `weakref,
5581      alias("name")', and weakref without arguments, in turn,
5582      implicitly adds weak. */
5583
5584   if (args)
5585     {
5586       attr = tree_cons (get_identifier ("alias"), args, attr);
5587       attr = tree_cons (get_identifier ("weakref"), NULL_TREE, attr);
5588
5589       *no_add_attrs = true;
5590
5591       decl_attributes (node, attr, flags);
5592     }
5593   else
5594     {
5595       if (lookup_attribute ("alias", DECL_ATTRIBUTES (*node)))
5596         error ("%Jweakref attribute must appear before alias attribute",
5597                *node);
5598
5599       /* Can't call declare_weak because it wants this to be TREE_PUBLIC,
5600          and that isn't supported; and because it wants to add it to
5601          the list of weak decls, which isn't helpful.  */
5602       DECL_WEAK (*node) = 1;
5603     }
5604
5605   return NULL_TREE;
5606 }
5607
5608 /* Handle an "visibility" attribute; arguments as in
5609    struct attribute_spec.handler.  */
5610
5611 static tree
5612 handle_visibility_attribute (tree *node, tree name, tree args,
5613                              int ARG_UNUSED (flags),
5614                              bool *ARG_UNUSED (no_add_attrs))
5615 {
5616   tree decl = *node;
5617   tree id = TREE_VALUE (args);
5618   enum symbol_visibility vis;
5619
5620   if (TYPE_P (*node))
5621     {
5622       if (TREE_CODE (*node) == ENUMERAL_TYPE)
5623         /* OK */;
5624       else if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE)
5625         {
5626           warning (OPT_Wattributes, "%qE attribute ignored on non-class types",
5627                    name);
5628           return NULL_TREE;
5629         }
5630       else if (TYPE_FIELDS (*node))
5631         {
5632           error ("%qE attribute ignored because %qT is already defined",
5633                  name, *node);
5634           return NULL_TREE;
5635         }
5636     }
5637   else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl))
5638     {
5639       warning (OPT_Wattributes, "%qE attribute ignored", name);
5640       return NULL_TREE;
5641     }
5642
5643   if (TREE_CODE (id) != STRING_CST)
5644     {
5645       error ("visibility argument not a string");
5646       return NULL_TREE;
5647     }
5648
5649   /*  If this is a type, set the visibility on the type decl.  */
5650   if (TYPE_P (decl))
5651     {
5652       decl = TYPE_NAME (decl);
5653       if (!decl)
5654         return NULL_TREE;
5655       if (TREE_CODE (decl) == IDENTIFIER_NODE)
5656         {
5657            warning (OPT_Wattributes, "%qE attribute ignored on types",
5658                     name);
5659            return NULL_TREE;
5660         }
5661     }
5662
5663   if (strcmp (TREE_STRING_POINTER (id), "default") == 0)
5664     vis = VISIBILITY_DEFAULT;
5665   else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0)
5666     vis = VISIBILITY_INTERNAL;
5667   else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0)
5668     vis = VISIBILITY_HIDDEN;
5669   else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0)
5670     vis = VISIBILITY_PROTECTED;
5671   else
5672     {
5673       error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\"");
5674       vis = VISIBILITY_DEFAULT;
5675     }
5676
5677   if (DECL_VISIBILITY_SPECIFIED (decl)
5678       && vis != DECL_VISIBILITY (decl))
5679     {
5680       tree attributes = (TYPE_P (*node)
5681                          ? TYPE_ATTRIBUTES (*node)
5682                          : DECL_ATTRIBUTES (decl));
5683       if (lookup_attribute ("visibility", attributes))
5684         error ("%qD redeclared with different visibility", decl);
5685       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
5686                && lookup_attribute ("dllimport", attributes))
5687         error ("%qD was declared %qs which implies default visibility",
5688                decl, "dllimport");
5689       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
5690                && lookup_attribute ("dllexport", attributes))
5691         error ("%qD was declared %qs which implies default visibility",
5692                decl, "dllexport");
5693     }
5694
5695   DECL_VISIBILITY (decl) = vis;
5696   DECL_VISIBILITY_SPECIFIED (decl) = 1;
5697
5698   /* Go ahead and attach the attribute to the node as well.  This is needed
5699      so we can determine whether we have VISIBILITY_DEFAULT because the
5700      visibility was not specified, or because it was explicitly overridden
5701      from the containing scope.  */
5702
5703   return NULL_TREE;
5704 }
5705
5706 /* Determine the ELF symbol visibility for DECL, which is either a
5707    variable or a function.  It is an error to use this function if a
5708    definition of DECL is not available in this translation unit.
5709    Returns true if the final visibility has been determined by this
5710    function; false if the caller is free to make additional
5711    modifications.  */
5712
5713 bool
5714 c_determine_visibility (tree decl)
5715 {
5716   gcc_assert (TREE_CODE (decl) == VAR_DECL
5717               || TREE_CODE (decl) == FUNCTION_DECL);
5718
5719   /* If the user explicitly specified the visibility with an
5720      attribute, honor that.  DECL_VISIBILITY will have been set during
5721      the processing of the attribute.  We check for an explicit
5722      attribute, rather than just checking DECL_VISIBILITY_SPECIFIED,
5723      to distinguish the use of an attribute from the use of a "#pragma
5724      GCC visibility push(...)"; in the latter case we still want other
5725      considerations to be able to overrule the #pragma.  */
5726   if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl))
5727       || (TARGET_DLLIMPORT_DECL_ATTRIBUTES
5728           && (lookup_attribute ("dllimport", DECL_ATTRIBUTES (decl))
5729               || lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))))
5730     return true;
5731
5732   /* Set default visibility to whatever the user supplied with
5733      visibility_specified depending on #pragma GCC visibility.  */
5734   if (!DECL_VISIBILITY_SPECIFIED (decl))
5735     {
5736       DECL_VISIBILITY (decl) = default_visibility;
5737       DECL_VISIBILITY_SPECIFIED (decl) = visibility_options.inpragma;
5738     }
5739   return false;
5740 }
5741
5742 /* Handle an "tls_model" attribute; arguments as in
5743    struct attribute_spec.handler.  */
5744
5745 static tree
5746 handle_tls_model_attribute (tree *node, tree name, tree args,
5747                             int ARG_UNUSED (flags), bool *no_add_attrs)
5748 {
5749   tree id;
5750   tree decl = *node;
5751   enum tls_model kind;
5752
5753   *no_add_attrs = true;
5754
5755   if (!DECL_THREAD_LOCAL_P (decl))
5756     {
5757       warning (OPT_Wattributes, "%qE attribute ignored", name);
5758       return NULL_TREE;
5759     }
5760
5761   kind = DECL_TLS_MODEL (decl);
5762   id = TREE_VALUE (args);
5763   if (TREE_CODE (id) != STRING_CST)
5764     {
5765       error ("tls_model argument not a string");
5766       return NULL_TREE;
5767     }
5768
5769   if (!strcmp (TREE_STRING_POINTER (id), "local-exec"))
5770     kind = TLS_MODEL_LOCAL_EXEC;
5771   else if (!strcmp (TREE_STRING_POINTER (id), "initial-exec"))
5772     kind = TLS_MODEL_INITIAL_EXEC;
5773   else if (!strcmp (TREE_STRING_POINTER (id), "local-dynamic"))
5774     kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
5775   else if (!strcmp (TREE_STRING_POINTER (id), "global-dynamic"))
5776     kind = TLS_MODEL_GLOBAL_DYNAMIC;
5777   else
5778     error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\"");
5779
5780   DECL_TLS_MODEL (decl) = kind;
5781   return NULL_TREE;
5782 }
5783
5784 /* Handle a "no_instrument_function" attribute; arguments as in
5785    struct attribute_spec.handler.  */
5786
5787 static tree
5788 handle_no_instrument_function_attribute (tree *node, tree name,
5789                                          tree ARG_UNUSED (args),
5790                                          int ARG_UNUSED (flags),
5791                                          bool *no_add_attrs)
5792 {
5793   tree decl = *node;
5794
5795   if (TREE_CODE (decl) != FUNCTION_DECL)
5796     {
5797       error ("%J%qE attribute applies only to functions", decl, name);
5798       *no_add_attrs = true;
5799     }
5800   else if (DECL_INITIAL (decl))
5801     {
5802       error ("%Jcan%'t set %qE attribute after definition", decl, name);
5803       *no_add_attrs = true;
5804     }
5805   else
5806     DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
5807
5808   return NULL_TREE;
5809 }
5810
5811 /* Handle a "malloc" attribute; arguments as in
5812    struct attribute_spec.handler.  */
5813
5814 static tree
5815 handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5816                          int ARG_UNUSED (flags), bool *no_add_attrs)
5817 {
5818   if (TREE_CODE (*node) == FUNCTION_DECL
5819       && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node))))
5820     DECL_IS_MALLOC (*node) = 1;
5821   else
5822     {
5823       warning (OPT_Wattributes, "%qE attribute ignored", name);
5824       *no_add_attrs = true;
5825     }
5826
5827   return NULL_TREE;
5828 }
5829
5830 /* Handle a "alloc_size" attribute; arguments as in
5831    struct attribute_spec.handler.  */
5832
5833 static tree
5834 handle_alloc_size_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5835                              int ARG_UNUSED (flags), bool *no_add_attrs)
5836 {
5837   tree params = TYPE_ARG_TYPES (*node);
5838   unsigned arg_count = 0;
5839
5840   for (; TREE_CHAIN (params); params = TREE_CHAIN (params))
5841     arg_count ++;
5842
5843   for (; args; args = TREE_CHAIN (args))
5844     {
5845       tree position = TREE_VALUE (args);
5846
5847       if (TREE_CODE (position) != INTEGER_CST
5848           || TREE_INT_CST_HIGH (position)
5849           || TREE_INT_CST_LOW (position) < 1
5850           || TREE_INT_CST_LOW (position) > arg_count )
5851         {
5852           warning (OPT_Wattributes,
5853                    "alloc_size parameter outside range");
5854           *no_add_attrs = true;
5855           return NULL_TREE;
5856         }
5857     }
5858   return NULL_TREE;
5859 }
5860
5861 /* Handle a "returns_twice" attribute; arguments as in
5862    struct attribute_spec.handler.  */
5863
5864 static tree
5865 handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5866                          int ARG_UNUSED (flags), bool *no_add_attrs)
5867 {
5868   if (TREE_CODE (*node) == FUNCTION_DECL)
5869     DECL_IS_RETURNS_TWICE (*node) = 1;
5870   else
5871     {
5872       warning (OPT_Wattributes, "%qE attribute ignored", name);
5873       *no_add_attrs = true;
5874     }
5875
5876   return NULL_TREE;
5877 }
5878
5879 /* Handle a "no_limit_stack" attribute; arguments as in
5880    struct attribute_spec.handler.  */
5881
5882 static tree
5883 handle_no_limit_stack_attribute (tree *node, tree name,
5884                                  tree ARG_UNUSED (args),
5885                                  int ARG_UNUSED (flags),
5886                                  bool *no_add_attrs)
5887 {
5888   tree decl = *node;
5889
5890   if (TREE_CODE (decl) != FUNCTION_DECL)
5891     {
5892       error ("%J%qE attribute applies only to functions", decl, name);
5893       *no_add_attrs = true;
5894     }
5895   else if (DECL_INITIAL (decl))
5896     {
5897       error ("%Jcan%'t set %qE attribute after definition", decl, name);
5898       *no_add_attrs = true;
5899     }
5900   else
5901     DECL_NO_LIMIT_STACK (decl) = 1;
5902
5903   return NULL_TREE;
5904 }
5905
5906 /* Handle a "pure" attribute; arguments as in
5907    struct attribute_spec.handler.  */
5908
5909 static tree
5910 handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5911                        int ARG_UNUSED (flags), bool *no_add_attrs)
5912 {
5913   if (TREE_CODE (*node) == FUNCTION_DECL)
5914     DECL_IS_PURE (*node) = 1;
5915   /* ??? TODO: Support types.  */
5916   else
5917     {
5918       warning (OPT_Wattributes, "%qE attribute ignored", name);
5919       *no_add_attrs = true;
5920     }
5921
5922   return NULL_TREE;
5923 }
5924
5925 /* Handle a "no vops" attribute; arguments as in
5926    struct attribute_spec.handler.  */
5927
5928 static tree
5929 handle_novops_attribute (tree *node, tree ARG_UNUSED (name),
5930                          tree ARG_UNUSED (args), int ARG_UNUSED (flags),
5931                          bool *ARG_UNUSED (no_add_attrs))
5932 {
5933   gcc_assert (TREE_CODE (*node) == FUNCTION_DECL);
5934   DECL_IS_NOVOPS (*node) = 1;
5935   return NULL_TREE;
5936 }
5937
5938 /* Handle a "deprecated" attribute; arguments as in
5939    struct attribute_spec.handler.  */
5940
5941 static tree
5942 handle_deprecated_attribute (tree *node, tree name,
5943                              tree ARG_UNUSED (args), int flags,
5944                              bool *no_add_attrs)
5945 {
5946   tree type = NULL_TREE;
5947   int warn = 0;
5948   tree what = NULL_TREE;
5949
5950   if (DECL_P (*node))
5951     {
5952       tree decl = *node;
5953       type = TREE_TYPE (decl);
5954
5955       if (TREE_CODE (decl) == TYPE_DECL
5956           || TREE_CODE (decl) == PARM_DECL
5957           || TREE_CODE (decl) == VAR_DECL
5958           || TREE_CODE (decl) == FUNCTION_DECL
5959           || TREE_CODE (decl) == FIELD_DECL)
5960         TREE_DEPRECATED (decl) = 1;
5961       else
5962         warn = 1;
5963     }
5964   else if (TYPE_P (*node))
5965     {
5966       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5967         *node = build_variant_type_copy (*node);
5968       TREE_DEPRECATED (*node) = 1;
5969       type = *node;
5970     }
5971   else
5972     warn = 1;
5973
5974   if (warn)
5975     {
5976       *no_add_attrs = true;
5977       if (type && TYPE_NAME (type))
5978         {
5979           if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
5980             what = TYPE_NAME (*node);
5981           else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
5982                    && DECL_NAME (TYPE_NAME (type)))
5983             what = DECL_NAME (TYPE_NAME (type));
5984         }
5985       if (what)
5986         warning (OPT_Wattributes, "%qE attribute ignored for %qE", name, what);
5987       else
5988         warning (OPT_Wattributes, "%qE attribute ignored", name);
5989     }
5990
5991   return NULL_TREE;
5992 }
5993
5994 /* Handle a "vector_size" attribute; arguments as in
5995    struct attribute_spec.handler.  */
5996
5997 static tree
5998 handle_vector_size_attribute (tree *node, tree name, tree args,
5999                               int ARG_UNUSED (flags),
6000                               bool *no_add_attrs)
6001 {
6002   unsigned HOST_WIDE_INT vecsize, nunits;
6003   enum machine_mode orig_mode;
6004   tree type = *node, new_type, size;
6005
6006   *no_add_attrs = true;
6007
6008   size = TREE_VALUE (args);
6009
6010   if (!host_integerp (size, 1))
6011     {
6012       warning (OPT_Wattributes, "%qE attribute ignored", name);
6013       return NULL_TREE;
6014     }
6015
6016   /* Get the vector size (in bytes).  */
6017   vecsize = tree_low_cst (size, 1);
6018
6019   /* We need to provide for vector pointers, vector arrays, and
6020      functions returning vectors.  For example:
6021
6022        __attribute__((vector_size(16))) short *foo;
6023
6024      In this case, the mode is SI, but the type being modified is
6025      HI, so we need to look further.  */
6026
6027   while (POINTER_TYPE_P (type)
6028          || TREE_CODE (type) == FUNCTION_TYPE
6029          || TREE_CODE (type) == METHOD_TYPE
6030          || TREE_CODE (type) == ARRAY_TYPE)
6031     type = TREE_TYPE (type);
6032
6033   /* Get the mode of the type being modified.  */
6034   orig_mode = TYPE_MODE (type);
6035
6036   if (TREE_CODE (type) == RECORD_TYPE
6037       || TREE_CODE (type) == UNION_TYPE
6038       || TREE_CODE (type) == VECTOR_TYPE
6039       || (!SCALAR_FLOAT_MODE_P (orig_mode)
6040           && GET_MODE_CLASS (orig_mode) != MODE_INT
6041           && !ALL_SCALAR_FIXED_POINT_MODE_P (orig_mode))
6042       || !host_integerp (TYPE_SIZE_UNIT (type), 1))
6043     {
6044       error ("invalid vector type for attribute %qE", name);
6045       return NULL_TREE;
6046     }
6047
6048   if (vecsize % tree_low_cst (TYPE_SIZE_UNIT (type), 1))
6049     {
6050       error ("vector size not an integral multiple of component size");
6051       return NULL;
6052     }
6053
6054   if (vecsize == 0)
6055     {
6056       error ("zero vector size");
6057       return NULL;
6058     }
6059
6060   /* Calculate how many units fit in the vector.  */
6061   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
6062   if (nunits & (nunits - 1))
6063     {
6064       error ("number of components of the vector not a power of two");
6065       return NULL_TREE;
6066     }
6067
6068   new_type = build_vector_type (type, nunits);
6069
6070   /* Build back pointers if needed.  */
6071   *node = reconstruct_complex_type (*node, new_type);
6072
6073   return NULL_TREE;
6074 }
6075
6076 /* Handle the "nonnull" attribute.  */
6077 static tree
6078 handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
6079                           tree args, int ARG_UNUSED (flags),
6080                           bool *no_add_attrs)
6081 {
6082   tree type = *node;
6083   unsigned HOST_WIDE_INT attr_arg_num;
6084
6085   /* If no arguments are specified, all pointer arguments should be
6086      non-null.  Verify a full prototype is given so that the arguments
6087      will have the correct types when we actually check them later.  */
6088   if (!args)
6089     {
6090       if (!TYPE_ARG_TYPES (type))
6091         {
6092           error ("nonnull attribute without arguments on a non-prototype");
6093           *no_add_attrs = true;
6094         }
6095       return NULL_TREE;
6096     }
6097
6098   /* Argument list specified.  Verify that each argument number references
6099      a pointer argument.  */
6100   for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
6101     {
6102       tree argument;
6103       unsigned HOST_WIDE_INT arg_num = 0, ck_num;
6104
6105       if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
6106         {
6107           error ("nonnull argument has invalid operand number (argument %lu)",
6108                  (unsigned long) attr_arg_num);
6109           *no_add_attrs = true;
6110           return NULL_TREE;
6111         }
6112
6113       argument = TYPE_ARG_TYPES (type);
6114       if (argument)
6115         {
6116           for (ck_num = 1; ; ck_num++)
6117             {
6118               if (!argument || ck_num == arg_num)
6119                 break;
6120               argument = TREE_CHAIN (argument);
6121             }
6122
6123           if (!argument
6124               || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
6125             {
6126               error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)",
6127                      (unsigned long) attr_arg_num, (unsigned long) arg_num);
6128               *no_add_attrs = true;
6129               return NULL_TREE;
6130             }
6131
6132           if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
6133             {
6134               error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)",
6135                    (unsigned long) attr_arg_num, (unsigned long) arg_num);
6136               *no_add_attrs = true;
6137               return NULL_TREE;
6138             }
6139         }
6140     }
6141
6142   return NULL_TREE;
6143 }
6144
6145 /* Check the argument list of a function call for null in argument slots
6146    that are marked as requiring a non-null pointer argument.  The NARGS
6147    arguments are passed in the array ARGARRAY.
6148 */
6149
6150 static void
6151 check_function_nonnull (tree attrs, int nargs, tree *argarray)
6152 {
6153   tree a, args;
6154   int i;
6155
6156   for (a = attrs; a; a = TREE_CHAIN (a))
6157     {
6158       if (is_attribute_p ("nonnull", TREE_PURPOSE (a)))
6159         {
6160           args = TREE_VALUE (a);
6161
6162           /* Walk the argument list.  If we encounter an argument number we
6163              should check for non-null, do it.  If the attribute has no args,
6164              then every pointer argument is checked (in which case the check
6165              for pointer type is done in check_nonnull_arg).  */
6166           for (i = 0; i < nargs; i++)
6167             {
6168               if (!args || nonnull_check_p (args, i + 1))
6169                 check_function_arguments_recurse (check_nonnull_arg, NULL,
6170                                                   argarray[i],
6171                                                   i + 1);
6172             }
6173         }
6174     }
6175 }
6176
6177 /* Check that the Nth argument of a function call (counting backwards
6178    from the end) is a (pointer)0.  The NARGS arguments are passed in the
6179    array ARGARRAY.  */
6180
6181 static void
6182 check_function_sentinel (tree attrs, int nargs, tree *argarray, tree typelist)
6183 {
6184   tree attr = lookup_attribute ("sentinel", attrs);
6185
6186   if (attr)
6187     {
6188       int len = 0;
6189       int pos = 0;
6190       tree sentinel;
6191
6192       /* Skip over the named arguments.  */
6193       while (typelist && len < nargs)
6194         {
6195           typelist = TREE_CHAIN (typelist);
6196           len++;
6197         }
6198
6199       if (TREE_VALUE (attr))
6200         {
6201           tree p = TREE_VALUE (TREE_VALUE (attr));
6202           pos = TREE_INT_CST_LOW (p);
6203         }
6204
6205       /* The sentinel must be one of the varargs, i.e.
6206          in position >= the number of fixed arguments.  */
6207       if ((nargs - 1 - pos) < len)
6208         {
6209           warning (OPT_Wformat,
6210                    "not enough variable arguments to fit a sentinel");
6211           return;
6212         }
6213
6214       /* Validate the sentinel.  */
6215       sentinel = argarray[nargs - 1 - pos];
6216       if ((!POINTER_TYPE_P (TREE_TYPE (sentinel))
6217            || !integer_zerop (sentinel))
6218           /* Although __null (in C++) is only an integer we allow it
6219              nevertheless, as we are guaranteed that it's exactly
6220              as wide as a pointer, and we don't want to force
6221              users to cast the NULL they have written there.
6222              We warn with -Wstrict-null-sentinel, though.  */
6223           && (warn_strict_null_sentinel || null_node != sentinel))
6224         warning (OPT_Wformat, "missing sentinel in function call");
6225     }
6226 }
6227
6228 /* Helper for check_function_nonnull; given a list of operands which
6229    must be non-null in ARGS, determine if operand PARAM_NUM should be
6230    checked.  */
6231
6232 static bool
6233 nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num)
6234 {
6235   unsigned HOST_WIDE_INT arg_num = 0;
6236
6237   for (; args; args = TREE_CHAIN (args))
6238     {
6239       bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num);
6240
6241       gcc_assert (found);
6242
6243       if (arg_num == param_num)
6244         return true;
6245     }
6246   return false;
6247 }
6248
6249 /* Check that the function argument PARAM (which is operand number
6250    PARAM_NUM) is non-null.  This is called by check_function_nonnull
6251    via check_function_arguments_recurse.  */
6252
6253 static void
6254 check_nonnull_arg (void * ARG_UNUSED (ctx), tree param,
6255                    unsigned HOST_WIDE_INT param_num)
6256 {
6257   /* Just skip checking the argument if it's not a pointer.  This can
6258      happen if the "nonnull" attribute was given without an operand
6259      list (which means to check every pointer argument).  */
6260
6261   if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE)
6262     return;
6263
6264   if (integer_zerop (param))
6265     warning (OPT_Wnonnull, "null argument where non-null required "
6266              "(argument %lu)", (unsigned long) param_num);
6267 }
6268
6269 /* Helper for nonnull attribute handling; fetch the operand number
6270    from the attribute argument list.  */
6271
6272 static bool
6273 get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp)
6274 {
6275   /* Verify the arg number is a constant.  */
6276   if (TREE_CODE (arg_num_expr) != INTEGER_CST
6277       || TREE_INT_CST_HIGH (arg_num_expr) != 0)
6278     return false;
6279
6280   *valp = TREE_INT_CST_LOW (arg_num_expr);
6281   return true;
6282 }
6283
6284 /* Handle a "nothrow" attribute; arguments as in
6285    struct attribute_spec.handler.  */
6286
6287 static tree
6288 handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6289                           int ARG_UNUSED (flags), bool *no_add_attrs)
6290 {
6291   if (TREE_CODE (*node) == FUNCTION_DECL)
6292     TREE_NOTHROW (*node) = 1;
6293   /* ??? TODO: Support types.  */
6294   else
6295     {
6296       warning (OPT_Wattributes, "%qE attribute ignored", name);
6297       *no_add_attrs = true;
6298     }
6299
6300   return NULL_TREE;
6301 }
6302
6303 /* Handle a "cleanup" attribute; arguments as in
6304    struct attribute_spec.handler.  */
6305
6306 static tree
6307 handle_cleanup_attribute (tree *node, tree name, tree args,
6308                           int ARG_UNUSED (flags), bool *no_add_attrs)
6309 {
6310   tree decl = *node;
6311   tree cleanup_id, cleanup_decl;
6312
6313   /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do
6314      for global destructors in C++.  This requires infrastructure that
6315      we don't have generically at the moment.  It's also not a feature
6316      we'd be missing too much, since we do have attribute constructor.  */
6317   if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl))
6318     {
6319       warning (OPT_Wattributes, "%qE attribute ignored", name);
6320       *no_add_attrs = true;
6321       return NULL_TREE;
6322     }
6323
6324   /* Verify that the argument is a function in scope.  */
6325   /* ??? We could support pointers to functions here as well, if
6326      that was considered desirable.  */
6327   cleanup_id = TREE_VALUE (args);
6328   if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE)
6329     {
6330       error ("cleanup argument not an identifier");
6331       *no_add_attrs = true;
6332       return NULL_TREE;
6333     }
6334   cleanup_decl = lookup_name (cleanup_id);
6335   if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL)
6336     {
6337       error ("cleanup argument not a function");
6338       *no_add_attrs = true;
6339       return NULL_TREE;
6340     }
6341
6342   /* That the function has proper type is checked with the
6343      eventual call to build_function_call.  */
6344
6345   return NULL_TREE;
6346 }
6347
6348 /* Handle a "warn_unused_result" attribute.  No special handling.  */
6349
6350 static tree
6351 handle_warn_unused_result_attribute (tree *node, tree name,
6352                                tree ARG_UNUSED (args),
6353                                int ARG_UNUSED (flags), bool *no_add_attrs)
6354 {
6355   /* Ignore the attribute for functions not returning any value.  */
6356   if (VOID_TYPE_P (TREE_TYPE (*node)))
6357     {
6358       warning (OPT_Wattributes, "%qE attribute ignored", name);
6359       *no_add_attrs = true;
6360     }
6361
6362   return NULL_TREE;
6363 }
6364
6365 /* Handle a "sentinel" attribute.  */
6366
6367 static tree
6368 handle_sentinel_attribute (tree *node, tree name, tree args,
6369                            int ARG_UNUSED (flags), bool *no_add_attrs)
6370 {
6371   tree params = TYPE_ARG_TYPES (*node);
6372
6373   if (!params)
6374     {
6375       warning (OPT_Wattributes,
6376                "%qE attribute requires prototypes with named arguments", name);
6377       *no_add_attrs = true;
6378     }
6379   else
6380     {
6381       while (TREE_CHAIN (params))
6382         params = TREE_CHAIN (params);
6383
6384       if (VOID_TYPE_P (TREE_VALUE (params)))
6385         {
6386           warning (OPT_Wattributes,
6387                    "%qE attribute only applies to variadic functions", name);
6388           *no_add_attrs = true;
6389         }
6390     }
6391
6392   if (args)
6393     {
6394       tree position = TREE_VALUE (args);
6395
6396       if (TREE_CODE (position) != INTEGER_CST)
6397         {
6398           warning (OPT_Wattributes,
6399                    "requested position is not an integer constant");
6400           *no_add_attrs = true;
6401         }
6402       else
6403         {
6404           if (tree_int_cst_lt (position, integer_zero_node))
6405             {
6406               warning (OPT_Wattributes,
6407                        "requested position is less than zero");
6408               *no_add_attrs = true;
6409             }
6410         }
6411     }
6412
6413   return NULL_TREE;
6414 }
6415
6416 /* Handle a "type_generic" attribute.  */
6417
6418 static tree
6419 handle_type_generic_attribute (tree *node, tree ARG_UNUSED (name),
6420                                tree ARG_UNUSED (args), int ARG_UNUSED (flags),
6421                                bool * ARG_UNUSED (no_add_attrs))
6422 {
6423   /* Ensure we have a function type, with no arguments.  */
6424   gcc_assert (TREE_CODE (*node) == FUNCTION_TYPE && ! TYPE_ARG_TYPES (*node));
6425
6426   return NULL_TREE;
6427 }
6428 \f
6429 /* Check for valid arguments being passed to a function.
6430    ATTRS is a list of attributes.  There are NARGS arguments in the array
6431    ARGARRAY.  TYPELIST is the list of argument types for the function.
6432  */
6433 void
6434 check_function_arguments (tree attrs, int nargs, tree *argarray, tree typelist)
6435 {
6436   /* Check for null being passed in a pointer argument that must be
6437      non-null.  We also need to do this if format checking is enabled.  */
6438
6439   if (warn_nonnull)
6440     check_function_nonnull (attrs, nargs, argarray);
6441
6442   /* Check for errors in format strings.  */
6443
6444   if (warn_format || warn_missing_format_attribute)
6445     check_function_format (attrs, nargs, argarray);
6446
6447   if (warn_format)
6448     check_function_sentinel (attrs, nargs, argarray, typelist);
6449 }
6450
6451 /* Generic argument checking recursion routine.  PARAM is the argument to
6452    be checked.  PARAM_NUM is the number of the argument.  CALLBACK is invoked
6453    once the argument is resolved.  CTX is context for the callback.  */
6454 void
6455 check_function_arguments_recurse (void (*callback)
6456                                   (void *, tree, unsigned HOST_WIDE_INT),
6457                                   void *ctx, tree param,
6458                                   unsigned HOST_WIDE_INT param_num)
6459 {
6460   if ((TREE_CODE (param) == NOP_EXPR || TREE_CODE (param) == CONVERT_EXPR)
6461       && (TYPE_PRECISION (TREE_TYPE (param))
6462           == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (param, 0)))))
6463     {
6464       /* Strip coercion.  */
6465       check_function_arguments_recurse (callback, ctx,
6466                                         TREE_OPERAND (param, 0), param_num);
6467       return;
6468     }
6469
6470   if (TREE_CODE (param) == CALL_EXPR)
6471     {
6472       tree type = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (param)));
6473       tree attrs;
6474       bool found_format_arg = false;
6475
6476       /* See if this is a call to a known internationalization function
6477          that modifies a format arg.  Such a function may have multiple
6478          format_arg attributes (for example, ngettext).  */
6479
6480       for (attrs = TYPE_ATTRIBUTES (type);
6481            attrs;
6482            attrs = TREE_CHAIN (attrs))
6483         if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs)))
6484           {
6485             tree inner_arg;
6486             tree format_num_expr;
6487             int format_num;
6488             int i;
6489             call_expr_arg_iterator iter;
6490
6491             /* Extract the argument number, which was previously checked
6492                to be valid.  */
6493             format_num_expr = TREE_VALUE (TREE_VALUE (attrs));
6494
6495             gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST
6496                         && !TREE_INT_CST_HIGH (format_num_expr));
6497
6498             format_num = TREE_INT_CST_LOW (format_num_expr);
6499
6500             for (inner_arg = first_call_expr_arg (param, &iter), i = 1;
6501                  inner_arg != 0;
6502                  inner_arg = next_call_expr_arg (&iter), i++)
6503               if (i == format_num)
6504                 {
6505                   check_function_arguments_recurse (callback, ctx,
6506                                                     inner_arg, param_num);
6507                   found_format_arg = true;
6508                   break;
6509                 }
6510           }
6511
6512       /* If we found a format_arg attribute and did a recursive check,
6513          we are done with checking this argument.  Otherwise, we continue
6514          and this will be considered a non-literal.  */
6515       if (found_format_arg)
6516         return;
6517     }
6518
6519   if (TREE_CODE (param) == COND_EXPR)
6520     {
6521       /* Check both halves of the conditional expression.  */
6522       check_function_arguments_recurse (callback, ctx,
6523                                         TREE_OPERAND (param, 1), param_num);
6524       check_function_arguments_recurse (callback, ctx,
6525                                         TREE_OPERAND (param, 2), param_num);
6526       return;
6527     }
6528
6529   (*callback) (ctx, param, param_num);
6530 }
6531
6532 /* Function to help qsort sort FIELD_DECLs by name order.  */
6533
6534 int
6535 field_decl_cmp (const void *x_p, const void *y_p)
6536 {
6537   const tree *const x = (const tree *const) x_p;
6538   const tree *const y = (const tree *const) y_p;
6539
6540   if (DECL_NAME (*x) == DECL_NAME (*y))
6541     /* A nontype is "greater" than a type.  */
6542     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
6543   if (DECL_NAME (*x) == NULL_TREE)
6544     return -1;
6545   if (DECL_NAME (*y) == NULL_TREE)
6546     return 1;
6547   if (DECL_NAME (*x) < DECL_NAME (*y))
6548     return -1;
6549   return 1;
6550 }
6551
6552 static struct {
6553   gt_pointer_operator new_value;
6554   void *cookie;
6555 } resort_data;
6556
6557 /* This routine compares two fields like field_decl_cmp but using the
6558 pointer operator in resort_data.  */
6559
6560 static int
6561 resort_field_decl_cmp (const void *x_p, const void *y_p)
6562 {
6563   const tree *const x = (const tree *const) x_p;
6564   const tree *const y = (const tree *const) y_p;
6565
6566   if (DECL_NAME (*x) == DECL_NAME (*y))
6567     /* A nontype is "greater" than a type.  */
6568     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
6569   if (DECL_NAME (*x) == NULL_TREE)
6570     return -1;
6571   if (DECL_NAME (*y) == NULL_TREE)
6572     return 1;
6573   {
6574     tree d1 = DECL_NAME (*x);
6575     tree d2 = DECL_NAME (*y);
6576     resort_data.new_value (&d1, resort_data.cookie);
6577     resort_data.new_value (&d2, resort_data.cookie);
6578     if (d1 < d2)
6579       return -1;
6580   }
6581   return 1;
6582 }
6583
6584 /* Resort DECL_SORTED_FIELDS because pointers have been reordered.  */
6585
6586 void
6587 resort_sorted_fields (void *obj,
6588                       void * ARG_UNUSED (orig_obj),
6589                       gt_pointer_operator new_value,
6590                       void *cookie)
6591 {
6592   struct sorted_fields_type *sf = (struct sorted_fields_type *) obj;
6593   resort_data.new_value = new_value;
6594   resort_data.cookie = cookie;
6595   qsort (&sf->elts[0], sf->len, sizeof (tree),
6596          resort_field_decl_cmp);
6597 }
6598
6599 /* Subroutine of c_parse_error.
6600    Return the result of concatenating LHS and RHS. RHS is really
6601    a string literal, its first character is indicated by RHS_START and
6602    RHS_SIZE is its length (including the terminating NUL character).
6603
6604    The caller is responsible for deleting the returned pointer.  */
6605
6606 static char *
6607 catenate_strings (const char *lhs, const char *rhs_start, int rhs_size)
6608 {
6609   const int lhs_size = strlen (lhs);
6610   char *result = XNEWVEC (char, lhs_size + rhs_size);
6611   strncpy (result, lhs, lhs_size);
6612   strncpy (result + lhs_size, rhs_start, rhs_size);
6613   return result;
6614 }
6615
6616 /* Issue the error given by GMSGID, indicating that it occurred before
6617    TOKEN, which had the associated VALUE.  */
6618
6619 void
6620 c_parse_error (const char *gmsgid, enum cpp_ttype token, tree value)
6621 {
6622 #define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2))
6623
6624   char *message = NULL;
6625
6626   if (token == CPP_EOF)
6627     message = catenate_messages (gmsgid, " at end of input");
6628   else if (token == CPP_CHAR || token == CPP_WCHAR)
6629     {
6630       unsigned int val = TREE_INT_CST_LOW (value);
6631       const char *const ell = (token == CPP_CHAR) ? "" : "L";
6632       if (val <= UCHAR_MAX && ISGRAPH (val))
6633         message = catenate_messages (gmsgid, " before %s'%c'");
6634       else
6635         message = catenate_messages (gmsgid, " before %s'\\x%x'");
6636
6637       error (message, ell, val);
6638       free (message);
6639       message = NULL;
6640     }
6641   else if (token == CPP_STRING || token == CPP_WSTRING)
6642     message = catenate_messages (gmsgid, " before string constant");
6643   else if (token == CPP_NUMBER)
6644     message = catenate_messages (gmsgid, " before numeric constant");
6645   else if (token == CPP_NAME)
6646     {
6647       message = catenate_messages (gmsgid, " before %qE");
6648       error (message, value);
6649       free (message);
6650       message = NULL;
6651     }
6652   else if (token == CPP_PRAGMA)
6653     message = catenate_messages (gmsgid, " before %<#pragma%>");
6654   else if (token == CPP_PRAGMA_EOL)
6655     message = catenate_messages (gmsgid, " before end of line");
6656   else if (token < N_TTYPES)
6657     {
6658       message = catenate_messages (gmsgid, " before %qs token");
6659       error (message, cpp_type2name (token));
6660       free (message);
6661       message = NULL;
6662     }
6663   else
6664     error (gmsgid);
6665
6666   if (message)
6667     {
6668       error (message);
6669       free (message);
6670     }
6671 #undef catenate_messages
6672 }
6673
6674 /* Walk a gimplified function and warn for functions whose return value is
6675    ignored and attribute((warn_unused_result)) is set.  This is done before
6676    inlining, so we don't have to worry about that.  */
6677
6678 void
6679 c_warn_unused_result (tree *top_p)
6680 {
6681   tree t = *top_p;
6682   tree_stmt_iterator i;
6683   tree fdecl, ftype;
6684
6685   switch (TREE_CODE (t))
6686     {
6687     case STATEMENT_LIST:
6688       for (i = tsi_start (*top_p); !tsi_end_p (i); tsi_next (&i))
6689         c_warn_unused_result (tsi_stmt_ptr (i));
6690       break;
6691
6692     case COND_EXPR:
6693       c_warn_unused_result (&COND_EXPR_THEN (t));
6694       c_warn_unused_result (&COND_EXPR_ELSE (t));
6695       break;
6696     case BIND_EXPR:
6697       c_warn_unused_result (&BIND_EXPR_BODY (t));
6698       break;
6699     case TRY_FINALLY_EXPR:
6700     case TRY_CATCH_EXPR:
6701       c_warn_unused_result (&TREE_OPERAND (t, 0));
6702       c_warn_unused_result (&TREE_OPERAND (t, 1));
6703       break;
6704     case CATCH_EXPR:
6705       c_warn_unused_result (&CATCH_BODY (t));
6706       break;
6707     case EH_FILTER_EXPR:
6708       c_warn_unused_result (&EH_FILTER_FAILURE (t));
6709       break;
6710
6711     case CALL_EXPR:
6712       if (TREE_USED (t))
6713         break;
6714
6715       /* This is a naked call, as opposed to a CALL_EXPR nested inside
6716          a MODIFY_EXPR.  All calls whose value is ignored should be
6717          represented like this.  Look for the attribute.  */
6718       fdecl = get_callee_fndecl (t);
6719       if (fdecl)
6720         ftype = TREE_TYPE (fdecl);
6721       else
6722         {
6723           ftype = TREE_TYPE (CALL_EXPR_FN (t));
6724           /* Look past pointer-to-function to the function type itself.  */
6725           ftype = TREE_TYPE (ftype);
6726         }
6727
6728       if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype)))
6729         {
6730           if (fdecl)
6731             warning (0, "%Hignoring return value of %qD, "
6732                      "declared with attribute warn_unused_result",
6733                      EXPR_LOCUS (t), fdecl);
6734           else
6735             warning (0, "%Hignoring return value of function "
6736                      "declared with attribute warn_unused_result",
6737                      EXPR_LOCUS (t));
6738         }
6739       break;
6740
6741     default:
6742       /* Not a container, not a call, or a call whose value is used.  */
6743       break;
6744     }
6745 }
6746
6747 /* Convert a character from the host to the target execution character
6748    set.  cpplib handles this, mostly.  */
6749
6750 HOST_WIDE_INT
6751 c_common_to_target_charset (HOST_WIDE_INT c)
6752 {
6753   /* Character constants in GCC proper are sign-extended under -fsigned-char,
6754      zero-extended under -fno-signed-char.  cpplib insists that characters
6755      and character constants are always unsigned.  Hence we must convert
6756      back and forth.  */
6757   cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1);
6758
6759   uc = cpp_host_to_exec_charset (parse_in, uc);
6760
6761   if (flag_signed_char)
6762     return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE)
6763                                >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE);
6764   else
6765     return uc;
6766 }
6767
6768 /* Build the result of __builtin_offsetof.  EXPR is a nested sequence of
6769    component references, with STOP_REF, or alternatively an INDIRECT_REF of
6770    NULL, at the bottom; much like the traditional rendering of offsetof as a
6771    macro.  Returns the folded and properly cast result.  */
6772
6773 static tree
6774 fold_offsetof_1 (tree expr, tree stop_ref)
6775 {
6776   enum tree_code code = PLUS_EXPR;
6777   tree base, off, t;
6778
6779   if (expr == stop_ref && TREE_CODE (expr) != ERROR_MARK)
6780     return size_zero_node;
6781
6782   switch (TREE_CODE (expr))
6783     {
6784     case ERROR_MARK:
6785       return expr;
6786
6787     case VAR_DECL:
6788       error ("cannot apply %<offsetof%> to static data member %qD", expr);
6789       return error_mark_node;
6790
6791     case CALL_EXPR:
6792       error ("cannot apply %<offsetof%> when %<operator[]%> is overloaded");
6793       return error_mark_node;
6794
6795     case INTEGER_CST:
6796       gcc_assert (integer_zerop (expr));
6797       return size_zero_node;
6798
6799     case NOP_EXPR:
6800     case INDIRECT_REF:
6801       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
6802       gcc_assert (base == error_mark_node || base == size_zero_node);
6803       return base;
6804
6805     case COMPONENT_REF:
6806       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
6807       if (base == error_mark_node)
6808         return base;
6809
6810       t = TREE_OPERAND (expr, 1);
6811       if (DECL_C_BIT_FIELD (t))
6812         {
6813           error ("attempt to take address of bit-field structure "
6814                  "member %qD", t);
6815           return error_mark_node;
6816         }
6817       off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t),
6818                         size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t), 1)
6819                                   / BITS_PER_UNIT));
6820       break;
6821
6822     case ARRAY_REF:
6823       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
6824       if (base == error_mark_node)
6825         return base;
6826
6827       t = TREE_OPERAND (expr, 1);
6828       if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0)
6829         {
6830           code = MINUS_EXPR;
6831           t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t);
6832         }
6833       t = convert (sizetype, t);
6834       off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
6835       break;
6836
6837     case COMPOUND_EXPR:
6838       /* Handle static members of volatile structs.  */
6839       t = TREE_OPERAND (expr, 1);
6840       gcc_assert (TREE_CODE (t) == VAR_DECL);
6841       return fold_offsetof_1 (t, stop_ref);
6842
6843     default:
6844       gcc_unreachable ();
6845     }
6846
6847   return size_binop (code, base, off);
6848 }
6849
6850 tree
6851 fold_offsetof (tree expr, tree stop_ref)
6852 {
6853   /* Convert back from the internal sizetype to size_t.  */
6854   return convert (size_type_node, fold_offsetof_1 (expr, stop_ref));
6855 }
6856
6857 /* Print an error message for an invalid lvalue.  USE says
6858    how the lvalue is being used and so selects the error message.  */
6859
6860 void
6861 lvalue_error (enum lvalue_use use)
6862 {
6863   switch (use)
6864     {
6865     case lv_assign:
6866       error ("lvalue required as left operand of assignment");
6867       break;
6868     case lv_increment:
6869       error ("lvalue required as increment operand");
6870       break;
6871     case lv_decrement:
6872       error ("lvalue required as decrement operand");
6873       break;
6874     case lv_addressof:
6875       error ("lvalue required as unary %<&%> operand");
6876       break;
6877     case lv_asm:
6878       error ("lvalue required in asm statement");
6879       break;
6880     default:
6881       gcc_unreachable ();
6882     }
6883 }
6884 \f
6885 /* *PTYPE is an incomplete array.  Complete it with a domain based on
6886    INITIAL_VALUE.  If INITIAL_VALUE is not present, use 1 if DO_DEFAULT
6887    is true.  Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered,
6888    2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty.  */
6889
6890 int
6891 complete_array_type (tree *ptype, tree initial_value, bool do_default)
6892 {
6893   tree maxindex, type, main_type, elt, unqual_elt;
6894   int failure = 0, quals;
6895   hashval_t hashcode = 0;
6896
6897   maxindex = size_zero_node;
6898   if (initial_value)
6899     {
6900       if (TREE_CODE (initial_value) == STRING_CST)
6901         {
6902           int eltsize
6903             = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value)));
6904           maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1);
6905         }
6906       else if (TREE_CODE (initial_value) == CONSTRUCTOR)
6907         {
6908           VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (initial_value);
6909
6910           if (VEC_empty (constructor_elt, v))
6911             {
6912               if (pedantic)
6913                 failure = 3;
6914               maxindex = integer_minus_one_node;
6915             }
6916           else
6917             {
6918               tree curindex;
6919               unsigned HOST_WIDE_INT cnt;
6920               constructor_elt *ce;
6921
6922               if (VEC_index (constructor_elt, v, 0)->index)
6923                 maxindex = fold_convert (sizetype,
6924                                          VEC_index (constructor_elt,
6925                                                     v, 0)->index);
6926               curindex = maxindex;
6927
6928               for (cnt = 1;
6929                    VEC_iterate (constructor_elt, v, cnt, ce);
6930                    cnt++)
6931                 {
6932                   if (ce->index)
6933                     curindex = fold_convert (sizetype, ce->index);
6934                   else
6935                     curindex = size_binop (PLUS_EXPR, curindex, size_one_node);
6936
6937                   if (tree_int_cst_lt (maxindex, curindex))
6938                     maxindex = curindex;
6939                 }
6940             }
6941         }
6942       else
6943         {
6944           /* Make an error message unless that happened already.  */
6945           if (initial_value != error_mark_node)
6946             failure = 1;
6947         }
6948     }
6949   else
6950     {
6951       failure = 2;
6952       if (!do_default)
6953         return failure;
6954     }
6955
6956   type = *ptype;
6957   elt = TREE_TYPE (type);
6958   quals = TYPE_QUALS (strip_array_types (elt));
6959   if (quals == 0)
6960     unqual_elt = elt;
6961   else
6962     unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
6963
6964   /* Using build_distinct_type_copy and modifying things afterward instead
6965      of using build_array_type to create a new type preserves all of the
6966      TYPE_LANG_FLAG_? bits that the front end may have set.  */
6967   main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
6968   TREE_TYPE (main_type) = unqual_elt;
6969   TYPE_DOMAIN (main_type) = build_index_type (maxindex);
6970   layout_type (main_type);
6971
6972   /* Make sure we have the canonical MAIN_TYPE. */
6973   hashcode = iterative_hash_object (TYPE_HASH (unqual_elt), hashcode);
6974   hashcode = iterative_hash_object (TYPE_HASH (TYPE_DOMAIN (main_type)),
6975                                     hashcode);
6976   main_type = type_hash_canon (hashcode, main_type);
6977
6978   /* Fix the canonical type.  */
6979   if (TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (main_type))
6980       || TYPE_STRUCTURAL_EQUALITY_P (TYPE_DOMAIN (main_type)))
6981     SET_TYPE_STRUCTURAL_EQUALITY (main_type);
6982   else if (TYPE_CANONICAL (TREE_TYPE (main_type)) != TREE_TYPE (main_type)
6983            || (TYPE_CANONICAL (TYPE_DOMAIN (main_type))
6984                != TYPE_DOMAIN (main_type)))
6985     TYPE_CANONICAL (main_type)
6986       = build_array_type (TYPE_CANONICAL (TREE_TYPE (main_type)),
6987                           TYPE_CANONICAL (TYPE_DOMAIN (main_type)));
6988   else
6989     TYPE_CANONICAL (main_type) = main_type;
6990
6991   if (quals == 0)
6992     type = main_type;
6993   else
6994     type = c_build_qualified_type (main_type, quals);
6995
6996   if (COMPLETE_TYPE_P (type)
6997       && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST
6998       && TREE_OVERFLOW (TYPE_SIZE_UNIT (type)))
6999     {
7000       error ("size of array is too large");
7001       /* If we proceed with the array type as it is, we'll eventually
7002          crash in tree_low_cst().  */
7003       type = error_mark_node;
7004     }
7005
7006   *ptype = type;
7007   return failure;
7008 }
7009
7010 \f
7011 /* Used to help initialize the builtin-types.def table.  When a type of
7012    the correct size doesn't exist, use error_mark_node instead of NULL.
7013    The later results in segfaults even when a decl using the type doesn't
7014    get invoked.  */
7015
7016 tree
7017 builtin_type_for_size (int size, bool unsignedp)
7018 {
7019   tree type = lang_hooks.types.type_for_size (size, unsignedp);
7020   return type ? type : error_mark_node;
7021 }
7022
7023 /* A helper function for resolve_overloaded_builtin in resolving the
7024    overloaded __sync_ builtins.  Returns a positive power of 2 if the
7025    first operand of PARAMS is a pointer to a supported data type.
7026    Returns 0 if an error is encountered.  */
7027
7028 static int
7029 sync_resolve_size (tree function, tree params)
7030 {
7031   tree type;
7032   int size;
7033
7034   if (params == NULL)
7035     {
7036       error ("too few arguments to function %qE", function);
7037       return 0;
7038     }
7039
7040   type = TREE_TYPE (TREE_VALUE (params));
7041   if (TREE_CODE (type) != POINTER_TYPE)
7042     goto incompatible;
7043
7044   type = TREE_TYPE (type);
7045   if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
7046     goto incompatible;
7047
7048   size = tree_low_cst (TYPE_SIZE_UNIT (type), 1);
7049   if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16)
7050     return size;
7051
7052  incompatible:
7053   error ("incompatible type for argument %d of %qE", 1, function);
7054   return 0;
7055 }
7056
7057 /* A helper function for resolve_overloaded_builtin.  Adds casts to
7058    PARAMS to make arguments match up with those of FUNCTION.  Drops
7059    the variadic arguments at the end.  Returns false if some error
7060    was encountered; true on success.  */
7061
7062 static bool
7063 sync_resolve_params (tree orig_function, tree function, tree params)
7064 {
7065   tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (function));
7066   tree ptype;
7067   int number;
7068
7069   /* We've declared the implementation functions to use "volatile void *"
7070      as the pointer parameter, so we shouldn't get any complaints from the
7071      call to check_function_arguments what ever type the user used.  */
7072   arg_types = TREE_CHAIN (arg_types);
7073   ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params)));
7074   number = 2;
7075
7076   /* For the rest of the values, we need to cast these to FTYPE, so that we
7077      don't get warnings for passing pointer types, etc.  */
7078   while (arg_types != void_list_node)
7079     {
7080       tree val;
7081
7082       params = TREE_CHAIN (params);
7083       if (params == NULL)
7084         {
7085           error ("too few arguments to function %qE", orig_function);
7086           return false;
7087         }
7088
7089       /* ??? Ideally for the first conversion we'd use convert_for_assignment
7090          so that we get warnings for anything that doesn't match the pointer
7091          type.  This isn't portable across the C and C++ front ends atm.  */
7092       val = TREE_VALUE (params);
7093       val = convert (ptype, val);
7094       val = convert (TREE_VALUE (arg_types), val);
7095       TREE_VALUE (params) = val;
7096
7097       arg_types = TREE_CHAIN (arg_types);
7098       number++;
7099     }
7100
7101   /* The definition of these primitives is variadic, with the remaining
7102      being "an optional list of variables protected by the memory barrier".
7103      No clue what that's supposed to mean, precisely, but we consider all
7104      call-clobbered variables to be protected so we're safe.  */
7105   TREE_CHAIN (params) = NULL;
7106
7107   return true;
7108 }
7109
7110 /* A helper function for resolve_overloaded_builtin.  Adds a cast to
7111    RESULT to make it match the type of the first pointer argument in
7112    PARAMS.  */
7113
7114 static tree
7115 sync_resolve_return (tree params, tree result)
7116 {
7117   tree ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params)));
7118   ptype = TYPE_MAIN_VARIANT (ptype);
7119   return convert (ptype, result);
7120 }
7121
7122 /* Some builtin functions are placeholders for other expressions.  This
7123    function should be called immediately after parsing the call expression
7124    before surrounding code has committed to the type of the expression.
7125
7126    FUNCTION is the DECL that has been invoked; it is known to be a builtin.
7127    PARAMS is the argument list for the call.  The return value is non-null
7128    when expansion is complete, and null if normal processing should
7129    continue.  */
7130
7131 tree
7132 resolve_overloaded_builtin (tree function, tree params)
7133 {
7134   enum built_in_function orig_code = DECL_FUNCTION_CODE (function);
7135   switch (DECL_BUILT_IN_CLASS (function))
7136     {
7137     case BUILT_IN_NORMAL:
7138       break;
7139     case BUILT_IN_MD:
7140       if (targetm.resolve_overloaded_builtin)
7141         return targetm.resolve_overloaded_builtin (function, params);
7142       else
7143         return NULL_TREE;
7144     default:
7145       return NULL_TREE;
7146     }
7147
7148   /* Handle BUILT_IN_NORMAL here.  */
7149   switch (orig_code)
7150     {
7151     case BUILT_IN_FETCH_AND_ADD_N:
7152     case BUILT_IN_FETCH_AND_SUB_N:
7153     case BUILT_IN_FETCH_AND_OR_N:
7154     case BUILT_IN_FETCH_AND_AND_N:
7155     case BUILT_IN_FETCH_AND_XOR_N:
7156     case BUILT_IN_FETCH_AND_NAND_N:
7157     case BUILT_IN_ADD_AND_FETCH_N:
7158     case BUILT_IN_SUB_AND_FETCH_N:
7159     case BUILT_IN_OR_AND_FETCH_N:
7160     case BUILT_IN_AND_AND_FETCH_N:
7161     case BUILT_IN_XOR_AND_FETCH_N:
7162     case BUILT_IN_NAND_AND_FETCH_N:
7163     case BUILT_IN_BOOL_COMPARE_AND_SWAP_N:
7164     case BUILT_IN_VAL_COMPARE_AND_SWAP_N:
7165     case BUILT_IN_LOCK_TEST_AND_SET_N:
7166     case BUILT_IN_LOCK_RELEASE_N:
7167       {
7168         int n = sync_resolve_size (function, params);
7169         tree new_function, result;
7170
7171         if (n == 0)
7172           return error_mark_node;
7173
7174         new_function = built_in_decls[orig_code + exact_log2 (n) + 1];
7175         if (!sync_resolve_params (function, new_function, params))
7176           return error_mark_node;
7177
7178         result = build_function_call (new_function, params);
7179         if (orig_code != BUILT_IN_BOOL_COMPARE_AND_SWAP_N
7180             && orig_code != BUILT_IN_LOCK_RELEASE_N)
7181           result = sync_resolve_return (params, result);
7182
7183         return result;
7184       }
7185
7186     default:
7187       return NULL_TREE;
7188     }
7189 }
7190
7191 /* Ignoring their sign, return true if two scalar types are the same.  */
7192 bool
7193 same_scalar_type_ignoring_signedness (tree t1, tree t2)
7194 {
7195   enum tree_code c1 = TREE_CODE (t1), c2 = TREE_CODE (t2);
7196
7197   gcc_assert ((c1 == INTEGER_TYPE || c1 == REAL_TYPE || c1 == FIXED_POINT_TYPE)
7198               && (c2 == INTEGER_TYPE || c2 == REAL_TYPE
7199                   || c2 == FIXED_POINT_TYPE));
7200
7201   /* Equality works here because c_common_signed_type uses
7202      TYPE_MAIN_VARIANT.  */
7203   return c_common_signed_type (t1)
7204     == c_common_signed_type (t2);
7205 }
7206
7207 /* Check for missing format attributes on function pointers.  LTYPE is
7208    the new type or left-hand side type.  RTYPE is the old type or
7209    right-hand side type.  Returns TRUE if LTYPE is missing the desired
7210    attribute.  */
7211
7212 bool
7213 check_missing_format_attribute (tree ltype, tree rtype)
7214 {
7215   tree const ttr = TREE_TYPE (rtype), ttl = TREE_TYPE (ltype);
7216   tree ra;
7217
7218   for (ra = TYPE_ATTRIBUTES (ttr); ra; ra = TREE_CHAIN (ra))
7219     if (is_attribute_p ("format", TREE_PURPOSE (ra)))
7220       break;
7221   if (ra)
7222     {
7223       tree la;
7224       for (la = TYPE_ATTRIBUTES (ttl); la; la = TREE_CHAIN (la))
7225         if (is_attribute_p ("format", TREE_PURPOSE (la)))
7226           break;
7227       return !la;
7228     }
7229   else
7230     return false;
7231 }
7232
7233 /* Subscripting with type char is likely to lose on a machine where
7234    chars are signed.  So warn on any machine, but optionally.  Don't
7235    warn for unsigned char since that type is safe.  Don't warn for
7236    signed char because anyone who uses that must have done so
7237    deliberately. Furthermore, we reduce the false positive load by
7238    warning only for non-constant value of type char.  */
7239
7240 void
7241 warn_array_subscript_with_type_char (tree index)
7242 {
7243   if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node
7244       && TREE_CODE (index) != INTEGER_CST)
7245     warning (OPT_Wchar_subscripts, "array subscript has type %<char%>");
7246 }
7247
7248 /* Implement -Wparentheses for the unexpected C precedence rules, to
7249    cover cases like x + y << z which readers are likely to
7250    misinterpret.  We have seen an expression in which CODE is a binary
7251    operator used to combine expressions headed by CODE_LEFT and
7252    CODE_RIGHT.  CODE_LEFT and CODE_RIGHT may be ERROR_MARK, which
7253    means that that side of the expression was not formed using a
7254    binary operator, or it was enclosed in parentheses.  */
7255
7256 void
7257 warn_about_parentheses (enum tree_code code, enum tree_code code_left,
7258                         enum tree_code code_right)
7259 {
7260   if (!warn_parentheses)
7261     return;
7262
7263   if (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
7264     {
7265       if (code_left == PLUS_EXPR || code_left == MINUS_EXPR
7266           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7267         warning (OPT_Wparentheses,
7268                  "suggest parentheses around + or - inside shift");
7269     }
7270
7271   if (code == TRUTH_ORIF_EXPR)
7272     {
7273       if (code_left == TRUTH_ANDIF_EXPR
7274           || code_right == TRUTH_ANDIF_EXPR)
7275         warning (OPT_Wparentheses,
7276                  "suggest parentheses around && within ||");
7277     }
7278
7279   if (code == BIT_IOR_EXPR)
7280     {
7281       if (code_left == BIT_AND_EXPR || code_left == BIT_XOR_EXPR
7282           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
7283           || code_right == BIT_AND_EXPR || code_right == BIT_XOR_EXPR
7284           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7285         warning (OPT_Wparentheses,
7286                  "suggest parentheses around arithmetic in operand of |");
7287       /* Check cases like x|y==z */
7288       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7289           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7290         warning (OPT_Wparentheses,
7291                  "suggest parentheses around comparison in operand of |");
7292     }
7293
7294   if (code == BIT_XOR_EXPR)
7295     {
7296       if (code_left == BIT_AND_EXPR
7297           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
7298           || code_right == BIT_AND_EXPR
7299           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7300         warning (OPT_Wparentheses,
7301                  "suggest parentheses around arithmetic in operand of ^");
7302       /* Check cases like x^y==z */
7303       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7304           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7305         warning (OPT_Wparentheses,
7306                  "suggest parentheses around comparison in operand of ^");
7307     }
7308
7309   if (code == BIT_AND_EXPR)
7310     {
7311       if (code_left == PLUS_EXPR || code_left == MINUS_EXPR
7312           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7313         warning (OPT_Wparentheses,
7314                  "suggest parentheses around + or - in operand of &");
7315       /* Check cases like x&y==z */
7316       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7317           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7318         warning (OPT_Wparentheses,
7319                  "suggest parentheses around comparison in operand of &");
7320     }
7321
7322   if (code == EQ_EXPR || code == NE_EXPR)
7323     {
7324       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7325           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7326         warning (OPT_Wparentheses,
7327                  "suggest parentheses around comparison in operand of %s",
7328                  code == EQ_EXPR ? "==" : "!=");
7329     }
7330   else if (TREE_CODE_CLASS (code) == tcc_comparison)
7331     {
7332       if ((TREE_CODE_CLASS (code_left) == tcc_comparison
7333            && code_left != NE_EXPR && code_left != EQ_EXPR)
7334           || (TREE_CODE_CLASS (code_right) == tcc_comparison
7335               && code_right != NE_EXPR && code_right != EQ_EXPR))
7336         warning (OPT_Wparentheses, "comparisons like X<=Y<=Z do not "
7337                  "have their mathematical meaning");
7338     }
7339 }
7340
7341 /* If LABEL (a LABEL_DECL) has not been used, issue a warning.  */
7342
7343 void
7344 warn_for_unused_label (tree label)
7345 {
7346   if (!TREE_USED (label))
7347     {
7348       if (DECL_INITIAL (label))
7349         warning (OPT_Wunused_label, "label %q+D defined but not used", label);
7350       else
7351         warning (OPT_Wunused_label, "label %q+D declared but not defined", label);
7352     }
7353 }
7354
7355 #ifndef TARGET_HAS_TARGETCM
7356 struct gcc_targetcm targetcm = TARGETCM_INITIALIZER;
7357 #endif
7358
7359 /* Warn for division by zero according to the value of DIVISOR.  */
7360
7361 void
7362 warn_for_div_by_zero (tree divisor)
7363 {
7364   /* If DIVISOR is zero, and has integral or fixed-point type, issue a warning
7365      about division by zero.  Do not issue a warning if DIVISOR has a
7366      floating-point type, since we consider 0.0/0.0 a valid way of
7367      generating a NaN.  */
7368   if (skip_evaluation == 0
7369       && (integer_zerop (divisor) || fixed_zerop (divisor)))
7370     warning (OPT_Wdiv_by_zero, "division by zero");
7371 }
7372
7373 #include "gt-c-common.h"