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,
 519                                          bool *);
 520 static tree handle_flatten_attribute (tree *, tree, tree, int, bool *);
 521 static tree handle_used_attribute (tree *, tree, tree, int, bool *);
 522 static tree handle_unused_attribute (tree *, tree, tree, int, bool *);
 523 static tree handle_externally_visible_attribute (tree *, tree, tree, int,
 524                                                  bool *);
 525 static tree handle_const_attribute (tree *, tree, tree, int, bool *);
 526 static tree handle_transparent_union_attribute (tree *, tree, tree,
 527                                                 int, bool *);
 528 static tree handle_constructor_attribute (tree *, tree, tree, int, bool *);
 529 static tree handle_destructor_attribute (tree *, tree, tree, int, bool *);
 530 static tree handle_mode_attribute (tree *, tree, tree, int, bool *);
 531 static tree handle_section_attribute (tree *, tree, tree, int, bool *);
 532 static tree handle_aligned_attribute (tree *, tree, tree, int, bool *);
 533 static tree handle_weak_attribute (tree *, tree, tree, int, bool *) ;
 534 static tree handle_alias_attribute (tree *, tree, tree, int, bool *);
 535 static tree handle_weakref_attribute (tree *, tree, tree, int, bool *) ;
 536 static tree handle_visibility_attribute (tree *, tree, tree, int,
 537                                          bool *);
 538 static tree handle_tls_model_attribute (tree *, tree, tree, int,
 539                                         bool *);
 540 static tree handle_no_instrument_function_attribute (tree *, tree,
 541                                                      tree, int, bool *);
 542 static tree handle_malloc_attribute (tree *, tree, tree, int, bool *);
 543 static tree handle_returns_twice_attribute (tree *, tree, tree, int, bool *);
 544 static tree handle_no_limit_stack_attribute (tree *, tree, tree, int,
 545                                              bool *);
 546 static tree handle_pure_attribute (tree *, tree, tree, int, bool *);
 547 static tree handle_novops_attribute (tree *, tree, tree, int, bool *);
 548 static tree handle_deprecated_attribute (tree *, tree, tree, int,
 549                                          bool *);
 550 static tree handle_vector_size_attribute (tree *, tree, tree, int,
 551                                           bool *);
 552 static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *);
 553 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
 554 static tree handle_cleanup_attribute (tree *, tree, tree, int, bool *);
 555 static tree handle_warn_unused_result_attribute (tree *, tree, tree, int,
 556                                                  bool *);
 557 static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *);
 558 static tree handle_type_generic_attribute (tree *, tree, tree, int, bool *);
 559 static tree handle_alloc_size_attribute (tree *, tree, tree, int, bool *);
 560
 561 static void check_function_nonnull (tree, int, tree *);
 562 static void check_nonnull_arg (void *, tree, unsigned HOST_WIDE_INT);
 563 static bool nonnull_check_p (tree, unsigned HOST_WIDE_INT);
 564 static bool get_nonnull_operand (tree, unsigned HOST_WIDE_INT *);
 565 static int resort_field_decl_cmp (const void *, const void *);
 566
 567 /* Table of machine-independent attributes common to all C-like languages.  */
 568 const struct attribute_spec c_common_attribute_table[] =
 569 {
 570   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 571   { "packed",                 0, 0, false, false, false,
 572                               handle_packed_attribute },
 573   { "nocommon",               0, 0, true,  false, false,
 574                               handle_nocommon_attribute },
 575   { "common",                 0, 0, true,  false, false,
 576                               handle_common_attribute },
 577   /* FIXME: logically, noreturn attributes should be listed as
 578      "false, true, true" and apply to function types.  But implementing this
 579      would require all the places in the compiler that use TREE_THIS_VOLATILE
 580      on a decl to identify non-returning functions to be located and fixed
 581      to check the function type instead.  */
 582   { "noreturn",               0, 0, true,  false, false,
 583                               handle_noreturn_attribute },
 584   { "volatile",               0, 0, true,  false, false,
 585                               handle_noreturn_attribute },
 586   { "noinline",               0, 0, true,  false, false,
 587                               handle_noinline_attribute },
 588   { "always_inline",          0, 0, true,  false, false,
 589                               handle_always_inline_attribute },
 590   { "gnu_inline",             0, 0, true,  false, false,
 591                               handle_gnu_inline_attribute },
 592   { "flatten",                0, 0, true,  false, false,
 593                               handle_flatten_attribute },
 594   { "used",                   0, 0, true,  false, false,
 595                               handle_used_attribute },
 596   { "unused",                 0, 0, false, false, false,
 597                               handle_unused_attribute },
 598   { "externally_visible",     0, 0, true,  false, false,
 599                               handle_externally_visible_attribute },
 600   /* The same comments as for noreturn attributes apply to const ones.  */
 601   { "const",                  0, 0, true,  false, false,
 602                               handle_const_attribute },
 603   { "transparent_union",      0, 0, false, false, false,
 604                               handle_transparent_union_attribute },
 605   { "constructor",            0, 1, true,  false, false,
 606                               handle_constructor_attribute },
 607   { "destructor",             0, 1, true,  false, false,
 608                               handle_destructor_attribute },
 609   { "mode",                   1, 1, false,  true, false,
 610                               handle_mode_attribute },
 611   { "section",                1, 1, true,  false, false,
 612                               handle_section_attribute },
 613   { "aligned",                0, 1, false, false, false,
 614                               handle_aligned_attribute },
 615   { "weak",                   0, 0, true,  false, false,
 616                               handle_weak_attribute },
 617   { "alias",                  1, 1, true,  false, false,
 618                               handle_alias_attribute },
 619   { "weakref",                0, 1, true,  false, false,
 620                               handle_weakref_attribute },
 621   { "no_instrument_function", 0, 0, true,  false, false,
 622                               handle_no_instrument_function_attribute },
 623   { "malloc",                 0, 0, true,  false, false,
 624                               handle_malloc_attribute },
 625   { "returns_twice",          0, 0, true,  false, false,
 626                               handle_returns_twice_attribute },
 627   { "no_stack_limit",         0, 0, true,  false, false,
 628                               handle_no_limit_stack_attribute },
 629   { "pure",                   0, 0, true,  false, false,
 630                               handle_pure_attribute },
 631   /* For internal use (marking of builtins) only.  The name contains space
 632      to prevent its usage in source code.  */
 633   { "no vops",                0, 0, true,  false, false,
 634                               handle_novops_attribute },
 635   { "deprecated",             0, 0, false, false, false,
 636                               handle_deprecated_attribute },
 637   { "vector_size",            1, 1, false, true, false,
 638                               handle_vector_size_attribute },
 639   { "visibility",             1, 1, false, false, false,
 640                               handle_visibility_attribute },
 641   { "tls_model",              1, 1, true,  false, false,
 642                               handle_tls_model_attribute },
 643   { "nonnull",                0, -1, false, true, true,
 644                               handle_nonnull_attribute },
 645   { "nothrow",                0, 0, true,  false, false,
 646                               handle_nothrow_attribute },
 647   { "may_alias",              0, 0, false, true, false, NULL },
 648   { "cleanup",                1, 1, true, false, false,
 649                               handle_cleanup_attribute },
 650   { "warn_unused_result",     0, 0, false, true, true,
 651                               handle_warn_unused_result_attribute },
 652   { "sentinel",               0, 1, false, true, true,
 653                               handle_sentinel_attribute },
 654   /* For internal use (marking of builtins) only.  The name contains space
 655      to prevent its usage in source code.  */
 656   { "type generic",           0, 0, false, true, true,
 657                               handle_type_generic_attribute },
 658   { "alloc_size",             1, 2, false, true, true,
 659                               handle_alloc_size_attribute },
 660   { "cold",                   0, 0, true,  false, false,
 661                               handle_cold_attribute },
 662   { "hot",                    0, 0, true,  false, false,
 663                               handle_hot_attribute },
 664   { NULL,                     0, 0, false, false, false, NULL }
 665 };
 666
 667 /* Give the specifications for the format attributes, used by C and all
 668    descendants.  */
 669
 670 const struct attribute_spec c_common_format_attribute_table[] =
 671 {
 672   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 673   { "format",                 3, 3, false, true,  true,
 674                               handle_format_attribute },
 675   { "format_arg",             1, 1, false, true,  true,
 676                               handle_format_arg_attribute },
 677   { NULL,                     0, 0, false, false, false, NULL }
 678 };
 679
 680 /* Push current bindings for the function name VAR_DECLS.  */
 681
 682 void
 683 start_fname_decls (void)
 684 {
 685   unsigned ix;
 686   tree saved = NULL_TREE;
 687
 688   for (ix = 0; fname_vars[ix].decl; ix++)
 689     {
 690       tree decl = *fname_vars[ix].decl;
 691
 692       if (decl)
 693         {
 694           saved = tree_cons (decl, build_int_cst (NULL_TREE, ix), saved);
 695           *fname_vars[ix].decl = NULL_TREE;
 696         }
 697     }
 698   if (saved || saved_function_name_decls)
 699     /* Normally they'll have been NULL, so only push if we've got a
 700        stack, or they are non-NULL.  */
 701     saved_function_name_decls = tree_cons (saved, NULL_TREE,
 702                                            saved_function_name_decls);
 703 }
 704
 705 /* Finish up the current bindings, adding them into the current function's
 706    statement tree.  This must be done _before_ finish_stmt_tree is called.
 707    If there is no current function, we must be at file scope and no statements
 708    are involved. Pop the previous bindings.  */
 709
 710 void
 711 finish_fname_decls (void)
 712 {
 713   unsigned ix;
 714   tree stmts = NULL_TREE;
 715   tree stack = saved_function_name_decls;
 716
 717   for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack))
 718     append_to_statement_list (TREE_VALUE (stack), &stmts);
 719
 720   if (stmts)
 721     {
 722       tree *bodyp = &DECL_SAVED_TREE (current_function_decl);
 723
 724       if (TREE_CODE (*bodyp) == BIND_EXPR)
 725         bodyp = &BIND_EXPR_BODY (*bodyp);
 726
 727       append_to_statement_list_force (*bodyp, &stmts);
 728       *bodyp = stmts;
 729     }
 730
 731   for (ix = 0; fname_vars[ix].decl; ix++)
 732     *fname_vars[ix].decl = NULL_TREE;
 733
 734   if (stack)
 735     {
 736       /* We had saved values, restore them.  */
 737       tree saved;
 738
 739       for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved))
 740         {
 741           tree decl = TREE_PURPOSE (saved);
 742           unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved));
 743
 744           *fname_vars[ix].decl = decl;
 745         }
 746       stack = TREE_CHAIN (stack);
 747     }
 748   saved_function_name_decls = stack;
 749 }
 750
 751 /* Return the text name of the current function, suitably prettified
 752    by PRETTY_P.  Return string must be freed by caller.  */
 753
 754 const char *
 755 fname_as_string (int pretty_p)
 756 {
 757   const char *name = "top level";
 758   char *namep;
 759   int vrb = 2;
 760
 761   if (!pretty_p)
 762     {
 763       name = "";
 764       vrb = 0;
 765     }
 766
 767   if (current_function_decl)
 768     name = lang_hooks.decl_printable_name (current_function_decl, vrb);
 769
 770   if (c_lex_string_translate)
 771     {
 772       int len = strlen (name) + 3; /* Two for '"'s.  One for NULL.  */
 773       cpp_string cstr = { 0, 0 }, strname;
 774
 775       namep = XNEWVEC (char, len);
 776       snprintf (namep, len, "\"%s\"", name);
 777       strname.text = (unsigned char *) namep;
 778       strname.len = len - 1;
 779
 780       if (cpp_interpret_string (parse_in, &strname, 1, &cstr, false))
 781         {
 782           XDELETEVEC (namep);
 783           return (const char *) cstr.text;
 784         }
 785     }
 786   else
 787     namep = xstrdup (name);
 788
 789   return namep;
 790 }
 791
 792 /* Expand DECL if it declares an entity not handled by the
 793    common code.  */
 794
 795 int
 796 c_expand_decl (tree decl)
 797 {
 798   if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl))
 799     {
 800       /* Let the back-end know about this variable.  */
 801       if (!anon_aggr_type_p (TREE_TYPE (decl)))
 802         emit_local_var (decl);
 803       else
 804         expand_anon_union_decl (decl, NULL_TREE,
 805                                 DECL_ANON_UNION_ELEMS (decl));
 806     }
 807   else
 808     return 0;
 809
 810   return 1;
 811 }
 812
 813
 814 /* Return the VAR_DECL for a const char array naming the current
 815    function. If the VAR_DECL has not yet been created, create it
 816    now. RID indicates how it should be formatted and IDENTIFIER_NODE
 817    ID is its name (unfortunately C and C++ hold the RID values of
 818    keywords in different places, so we can't derive RID from ID in
 819    this language independent code.  */
 820
 821 tree
 822 fname_decl (unsigned int rid, tree id)
 823 {
 824   unsigned ix;
 825   tree decl = NULL_TREE;
 826
 827   for (ix = 0; fname_vars[ix].decl; ix++)
 828     if (fname_vars[ix].rid == rid)
 829       break;
 830
 831   decl = *fname_vars[ix].decl;
 832   if (!decl)
 833     {
 834       /* If a tree is built here, it would normally have the lineno of
 835          the current statement.  Later this tree will be moved to the
 836          beginning of the function and this line number will be wrong.
 837          To avoid this problem set the lineno to 0 here; that prevents
 838          it from appearing in the RTL.  */
 839       tree stmts;
 840       location_t saved_location = input_location;
 841 #ifdef USE_MAPPED_LOCATION
 842       input_location = UNKNOWN_LOCATION;
 843 #else
 844       input_line = 0;
 845 #endif
 846
 847       stmts = push_stmt_list ();
 848       decl = (*make_fname_decl) (id, fname_vars[ix].pretty);
 849       stmts = pop_stmt_list (stmts);
 850       if (!IS_EMPTY_STMT (stmts))
 851         saved_function_name_decls
 852           = tree_cons (decl, stmts, saved_function_name_decls);
 853       *fname_vars[ix].decl = decl;
 854       input_location = saved_location;
 855     }
 856   if (!ix && !current_function_decl)
 857     pedwarn ("%qD is not defined outside of function scope", decl);
 858
 859   return decl;
 860 }
 861
 862 /* Given a STRING_CST, give it a suitable array-of-chars data type.  */
 863
 864 tree
 865 fix_string_type (tree value)
 866 {
 867   const int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
 868   const int wide_flag = TREE_TYPE (value) == wchar_array_type_node;
 869   int length = TREE_STRING_LENGTH (value);
 870   int nchars;
 871   tree e_type, i_type, a_type;
 872
 873   /* Compute the number of elements, for the array type.  */
 874   nchars = wide_flag ? length / wchar_bytes : length;
 875
 876   /* C89 2.2.4.1, C99 5.2.4.1 (Translation limits).  The analogous
 877      limit in C++98 Annex B is very large (65536) and is not normative,
 878      so we do not diagnose it (warn_overlength_strings is forced off
 879      in c_common_post_options).  */
 880   if (warn_overlength_strings)
 881     {
 882       const int nchars_max = flag_isoc99 ? 4095 : 509;
 883       const int relevant_std = flag_isoc99 ? 99 : 90;
 884       if (nchars - 1 > nchars_max)
 885         /* Translators: The %d after 'ISO C' will be 90 or 99.  Do not
 886            separate the %d from the 'C'.  'ISO' should not be
 887            translated, but it may be moved after 'C%d' in languages
 888            where modifiers follow nouns.  */
 889         pedwarn ("string length %qd is greater than the length %qd "
 890                  "ISO C%d compilers are required to support",
 891                  nchars - 1, nchars_max, relevant_std);
 892     }
 893
 894   /* Create the array type for the string constant.  The ISO C++
 895      standard says that a string literal has type `const char[N]' or
 896      `const wchar_t[N]'.  We use the same logic when invoked as a C
 897      front-end with -Wwrite-strings.
 898      ??? We should change the type of an expression depending on the
 899      state of a warning flag.  We should just be warning -- see how
 900      this is handled in the C++ front-end for the deprecated implicit
 901      conversion from string literals to `char*' or `wchar_t*'.
 902
 903      The C++ front end relies on TYPE_MAIN_VARIANT of a cv-qualified
 904      array type being the unqualified version of that type.
 905      Therefore, if we are constructing an array of const char, we must
 906      construct the matching unqualified array type first.  The C front
 907      end does not require this, but it does no harm, so we do it
 908      unconditionally.  */
 909   e_type = wide_flag ? wchar_type_node : char_type_node;
 910   i_type = build_index_type (build_int_cst (NULL_TREE, nchars - 1));
 911   a_type = build_array_type (e_type, i_type);
 912   if (c_dialect_cxx() || warn_write_strings)
 913     a_type = c_build_qualified_type (a_type, TYPE_QUAL_CONST);
 914
 915   TREE_TYPE (value) = a_type;
 916   TREE_CONSTANT (value) = 1;
 917   TREE_INVARIANT (value) = 1;
 918   TREE_READONLY (value) = 1;
 919   TREE_STATIC (value) = 1;
 920   return value;
 921 }
 922 \f
 923 /* Print a warning if a constant expression had overflow in folding.
 924    Invoke this function on every expression that the language
 925    requires to be a constant expression.
 926    Note the ANSI C standard says it is erroneous for a
 927    constant expression to overflow.  */
 928
 929 void
 930 constant_expression_warning (tree value)
 931 {
 932   if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
 933        || TREE_CODE (value) == FIXED_CST
 934        || TREE_CODE (value) == VECTOR_CST
 935        || TREE_CODE (value) == COMPLEX_CST)
 936       && TREE_OVERFLOW (value)
 937       && warn_overflow
 938       && pedantic)
 939     pedwarn ("overflow in constant expression");
 940 }
 941
 942 /* Print a warning if an expression had overflow in folding and its
 943    operands hadn't.
 944
 945    Invoke this function on every expression that
 946    (1) appears in the source code, and
 947    (2) is a constant expression that overflowed, and
 948    (3) is not already checked by convert_and_check;
 949    however, do not invoke this function on operands of explicit casts
 950    or when the expression is the result of an operator and any operand
 951    already overflowed.  */
 952
 953 void
 954 overflow_warning (tree value)
 955 {
 956   if (skip_evaluation) return;
 957
 958   switch (TREE_CODE (value))
 959     {
 960     case INTEGER_CST:
 961       warning (OPT_Woverflow, "integer overflow in expression");
 962       break;
 963
 964     case REAL_CST:
 965       warning (OPT_Woverflow, "floating point overflow in expression");
 966       break;
 967
 968     case FIXED_CST:
 969       warning (OPT_Woverflow, "fixed-point overflow in expression");
 970       break;
 971
 972     case VECTOR_CST:
 973       warning (OPT_Woverflow, "vector overflow in expression");
 974       break;
 975
 976     case COMPLEX_CST:
 977       if (TREE_CODE (TREE_REALPART (value)) == INTEGER_CST)
 978         warning (OPT_Woverflow, "complex integer overflow in expression");
 979       else if (TREE_CODE (TREE_REALPART (value)) == REAL_CST)
 980         warning (OPT_Woverflow, "complex floating point overflow in expression");
 981       break;
 982
 983     default:
 984       break;
 985     }
 986 }
 987
 988
 989 /* Warn about use of a logical || / && operator being used in a
 990    context where it is likely that the bitwise equivalent was intended
 991    by the programmer. CODE is the TREE_CODE of the operator, ARG1
 992    and ARG2 the arguments.  */
 993
 994 void
 995 warn_logical_operator (enum tree_code code, tree arg1, tree
 996     arg2)
 997 {
 998   switch (code)
 999     {
1000       case TRUTH_ANDIF_EXPR:
1001       case TRUTH_ORIF_EXPR:
1002       case TRUTH_OR_EXPR:
1003       case TRUTH_AND_EXPR:
1004         if (!TREE_NO_WARNING (arg1)
1005             && INTEGRAL_TYPE_P (TREE_TYPE (arg1))
1006             && !CONSTANT_CLASS_P (arg1)
1007             && TREE_CODE (arg2) == INTEGER_CST
1008             && !integer_zerop (arg2))
1009           {
1010             warning (OPT_Wlogical_op,
1011                      "logical %<%s%> with non-zero constant "
1012                      "will always evaluate as true",
1013                      ((code == TRUTH_ANDIF_EXPR)
1014                       || (code == TRUTH_AND_EXPR)) ? "&&" : "||");
1015             TREE_NO_WARNING (arg1) = true;
1016           }
1017         break;
1018       default:
1019         break;
1020     }
1021 }
1022
1023
1024 /* Print a warning about casts that might indicate violation
1025    of strict aliasing rules if -Wstrict-aliasing is used and
1026    strict aliasing mode is in effect. OTYPE is the original
1027    TREE_TYPE of EXPR, and TYPE the type we're casting to. */
1028
1029 bool
1030 strict_aliasing_warning (tree otype, tree type, tree expr)
1031 {
1032   if (!(flag_strict_aliasing && POINTER_TYPE_P (type)
1033         && POINTER_TYPE_P (otype) && !VOID_TYPE_P (TREE_TYPE (type))))
1034     return false;
1035
1036   if ((warn_strict_aliasing > 1) && TREE_CODE (expr) == ADDR_EXPR
1037       && (DECL_P (TREE_OPERAND (expr, 0))
1038           || handled_component_p (TREE_OPERAND (expr, 0))))
1039     {
1040       /* Casting the address of an object to non void pointer. Warn
1041          if the cast breaks type based aliasing.  */
1042       if (!COMPLETE_TYPE_P (TREE_TYPE (type)) && warn_strict_aliasing == 2)
1043         {
1044           warning (OPT_Wstrict_aliasing, "type-punning to incomplete type "
1045                    "might break strict-aliasing rules");
1046           return true;
1047         }
1048       else
1049         {
1050           /* warn_strict_aliasing >= 3.   This includes the default (3).
1051              Only warn if the cast is dereferenced immediately.  */
1052           alias_set_type set1 =
1053             get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0)));
1054           alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1055
1056           if (!alias_sets_conflict_p (set1, set2))
1057             {
1058               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1059                        "pointer will break strict-aliasing rules");
1060               return true;
1061             }
1062           else if (warn_strict_aliasing == 2
1063                    && !alias_sets_must_conflict_p (set1, set2))
1064             {
1065               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1066                        "pointer might break strict-aliasing rules");
1067               return true;
1068             }
1069         }
1070     }
1071   else
1072     if ((warn_strict_aliasing == 1) && !VOID_TYPE_P (TREE_TYPE (otype)))
1073       {
1074         /* At this level, warn for any conversions, even if an address is
1075            not taken in the same statement.  This will likely produce many
1076            false positives, but could be useful to pinpoint problems that
1077            are not revealed at higher levels.  */
1078         alias_set_type set1 = get_alias_set (TREE_TYPE (otype));
1079         alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1080         if (!COMPLETE_TYPE_P (type)
1081             || !alias_sets_must_conflict_p (set1, set2))
1082           {
1083             warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1084                      "pointer might break strict-aliasing rules");
1085             return true;
1086           }
1087       }
1088
1089   return false;
1090 }
1091
1092 /* Print a warning about if (); or if () .. else; constructs
1093    via the special empty statement node that we create.  INNER_THEN
1094    and INNER_ELSE are the statement lists of the if and the else
1095    block.  */
1096
1097 void
1098 empty_if_body_warning (tree inner_then, tree inner_else)
1099 {
1100   if (TREE_CODE (inner_then) == STATEMENT_LIST
1101       && STATEMENT_LIST_TAIL (inner_then))
1102     inner_then = STATEMENT_LIST_TAIL (inner_then)->stmt;
1103
1104   if (inner_else && TREE_CODE (inner_else) == STATEMENT_LIST
1105       && STATEMENT_LIST_TAIL (inner_else))
1106     inner_else = STATEMENT_LIST_TAIL (inner_else)->stmt;
1107
1108   if (IS_EMPTY_STMT (inner_then) && !inner_else)
1109     warning (OPT_Wempty_body, "%Hsuggest braces around empty body "
1110              "in an %<if%> statement", EXPR_LOCUS (inner_then));
1111
1112   else if (inner_else && IS_EMPTY_STMT (inner_else))
1113     warning (OPT_Wempty_body, "%Hsuggest braces around empty body "
1114              "in an %<else%> statement", EXPR_LOCUS (inner_else));
1115 }
1116
1117 /* Warn for unlikely, improbable, or stupid DECL declarations
1118    of `main'.  */
1119
1120 void
1121 check_main_parameter_types (tree decl)
1122 {
1123   tree args;
1124   int argct = 0;
1125
1126   for (args = TYPE_ARG_TYPES (TREE_TYPE (decl)); args;
1127       args = TREE_CHAIN (args))
1128    {
1129      tree type = args ? TREE_VALUE (args) : 0;
1130
1131      if (type == void_type_node || type == error_mark_node )
1132        break;
1133
1134      ++argct;
1135      switch (argct)
1136        {
1137        case 1:
1138          if (TYPE_MAIN_VARIANT (type) != integer_type_node)
1139            pedwarn ("first argument of %q+D should be %<int%>", decl);
1140          break;
1141
1142        case 2:
1143          if (TREE_CODE (type) != POINTER_TYPE
1144              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1145              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1146                  != char_type_node))
1147            pedwarn ("second argument of %q+D should be %<char **%>",
1148                     decl);
1149          break;
1150
1151        case 3:
1152          if (TREE_CODE (type) != POINTER_TYPE
1153              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1154              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1155                  != char_type_node))
1156            pedwarn ("third argument of %q+D should probably be "
1157                     "%<char **%>", decl);
1158          break;
1159        }
1160    }
1161
1162   /* It is intentional that this message does not mention the third
1163     argument because it's only mentioned in an appendix of the
1164     standard.  */
1165   if (argct > 0 && (argct < 2 || argct > 3))
1166    pedwarn ("%q+D takes only zero or two arguments", decl);
1167 }
1168
1169 /* True if vector types T1 and T2 can be converted to each other
1170    without an explicit cast.  If EMIT_LAX_NOTE is true, and T1 and T2
1171    can only be converted with -flax-vector-conversions yet that is not
1172    in effect, emit a note telling the user about that option if such
1173    a note has not previously been emitted.  */
1174 bool
1175 vector_types_convertible_p (const_tree t1, const_tree t2, bool emit_lax_note)
1176 {
1177   static bool emitted_lax_note = false;
1178   bool convertible_lax;
1179
1180   if ((targetm.vector_opaque_p (t1) || targetm.vector_opaque_p (t2))
1181       && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)))
1182     return true;
1183
1184   convertible_lax =
1185     (tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2))
1186      && (TREE_CODE (TREE_TYPE (t1)) != REAL_TYPE ||
1187          TYPE_PRECISION (t1) == TYPE_PRECISION (t2))
1188      && (INTEGRAL_TYPE_P (TREE_TYPE (t1))
1189          == INTEGRAL_TYPE_P (TREE_TYPE (t2))));
1190
1191   if (!convertible_lax || flag_lax_vector_conversions)
1192     return convertible_lax;
1193
1194   if (TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1195       && comptypes (TREE_TYPE (t1), TREE_TYPE (t2)))
1196     return true;
1197
1198   if (emit_lax_note && !emitted_lax_note)
1199     {
1200       emitted_lax_note = true;
1201       inform ("use -flax-vector-conversions to permit "
1202               "conversions between vectors with differing "
1203               "element types or numbers of subparts");
1204     }
1205
1206   return false;
1207 }
1208
1209 /* Warns if the conversion of EXPR to TYPE may alter a value.
1210    This is a helper function for warnings_for_convert_and_check.  */
1211
1212 static void
1213 conversion_warning (tree type, tree expr)
1214 {
1215   bool give_warning = false;
1216
1217   unsigned int formal_prec = TYPE_PRECISION (type);
1218
1219   if (!warn_conversion && !warn_sign_conversion)
1220     return;
1221
1222   if (TREE_CODE (expr) == REAL_CST || TREE_CODE (expr) == INTEGER_CST)
1223     {
1224       /* Warn for real constant that is not an exact integer converted
1225          to integer type.  */
1226       if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
1227           && TREE_CODE (type) == INTEGER_TYPE)
1228         {
1229           if (!real_isinteger (TREE_REAL_CST_PTR (expr), TYPE_MODE (TREE_TYPE (expr))))
1230             give_warning = true;
1231         }
1232       /* Warn for an integer constant that does not fit into integer type.  */
1233       else if (TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
1234                && TREE_CODE (type) == INTEGER_TYPE
1235                && !int_fits_type_p (expr, type))
1236         {
1237           if (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (TREE_TYPE (expr)))
1238             warning (OPT_Wsign_conversion,
1239                      "negative integer implicitly converted to unsigned type");
1240           else if (!TYPE_UNSIGNED (type) && TYPE_UNSIGNED (TREE_TYPE (expr)))
1241             warning (OPT_Wsign_conversion,
1242                      "conversion of unsigned constant value to negative integer");
1243           else
1244             give_warning = true;
1245         }
1246       else if (TREE_CODE (type) == REAL_TYPE)
1247         {
1248           /* Warn for an integer constant that does not fit into real type.  */
1249           if (TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE)
1250             {
1251               REAL_VALUE_TYPE a = real_value_from_int_cst (0, expr);
1252               if (!exact_real_truncate (TYPE_MODE (type), &a))
1253                 give_warning = true;
1254             }
1255           /* Warn for a real constant that does not fit into a smaller
1256              real type.  */
1257           else if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
1258                    && formal_prec < TYPE_PRECISION (TREE_TYPE (expr)))
1259             {
1260               REAL_VALUE_TYPE a = TREE_REAL_CST (expr);
1261               if (!exact_real_truncate (TYPE_MODE (type), &a))
1262                 give_warning = true;
1263             }
1264         }
1265
1266       if (give_warning)
1267         warning (OPT_Wconversion,
1268                  "conversion to %qT alters %qT constant value",
1269                  type, TREE_TYPE (expr));
1270     }
1271   else /* 'expr' is not a constant.  */
1272     {
1273       /* Warn for real types converted to integer types.  */
1274       if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
1275           && TREE_CODE (type) == INTEGER_TYPE)
1276         give_warning = true;
1277
1278       else if (TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
1279                && TREE_CODE (type) == INTEGER_TYPE)
1280         {
1281           /* Warn for integer types converted to smaller integer types.  */
1282           if (formal_prec < TYPE_PRECISION (TREE_TYPE (expr)))
1283             give_warning = true;
1284
1285           /* When they are the same width but different signedness,
1286              then the value may change.  */
1287           else if ((formal_prec == TYPE_PRECISION (TREE_TYPE (expr))
1288                     && TYPE_UNSIGNED (TREE_TYPE (expr)) != TYPE_UNSIGNED (type))
1289                    /* Even when converted to a bigger type, if the type is
1290                       unsigned but expr is signed, then negative values
1291                       will be changed.  */
1292                    || (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (TREE_TYPE (expr))))
1293             warning (OPT_Wsign_conversion,
1294                      "conversion to %qT from %qT may change the sign of the result",
1295                      type, TREE_TYPE (expr));
1296         }
1297
1298       /* Warn for integer types converted to real types if and only if
1299          all the range of values of the integer type cannot be
1300          represented by the real type.  */
1301       else if (TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
1302                && TREE_CODE (type) == REAL_TYPE)
1303         {
1304           tree type_low_bound = TYPE_MIN_VALUE (TREE_TYPE (expr));
1305           tree type_high_bound = TYPE_MAX_VALUE (TREE_TYPE (expr));
1306           REAL_VALUE_TYPE real_low_bound = real_value_from_int_cst (0, type_low_bound);
1307           REAL_VALUE_TYPE real_high_bound = real_value_from_int_cst (0, type_high_bound);
1308
1309           if (!exact_real_truncate (TYPE_MODE (type), &real_low_bound)
1310               || !exact_real_truncate (TYPE_MODE (type), &real_high_bound))
1311             give_warning = true;
1312         }
1313
1314       /* Warn for real types converted to smaller real types.  */
1315       else if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
1316                && TREE_CODE (type) == REAL_TYPE
1317                && formal_prec < TYPE_PRECISION (TREE_TYPE (expr)))
1318         give_warning = true;
1319
1320
1321       if (give_warning)
1322         warning (OPT_Wconversion,
1323                  "conversion to %qT from %qT may alter its value",
1324                  type, TREE_TYPE (expr));
1325     }
1326 }
1327
1328 /* Produce warnings after a conversion. RESULT is the result of
1329    converting EXPR to TYPE.  This is a helper function for
1330    convert_and_check and cp_convert_and_check.  */
1331
1332 void
1333 warnings_for_convert_and_check (tree type, tree expr, tree result)
1334 {
1335   if (TREE_CODE (expr) == INTEGER_CST
1336       && (TREE_CODE (type) == INTEGER_TYPE
1337           || TREE_CODE (type) == ENUMERAL_TYPE)
1338       && !int_fits_type_p (expr, type))
1339     {
1340       /* Do not diagnose overflow in a constant expression merely
1341          because a conversion overflowed.  */
1342       if (TREE_OVERFLOW (result))
1343         TREE_OVERFLOW (result) = TREE_OVERFLOW (expr);
1344
1345       if (TYPE_UNSIGNED (type))
1346         {
1347           /* This detects cases like converting -129 or 256 to
1348              unsigned char.  */
1349           if (!int_fits_type_p (expr, c_common_signed_type (type)))
1350             warning (OPT_Woverflow,
1351                      "large integer implicitly truncated to unsigned type");
1352           else
1353             conversion_warning (type, expr);
1354         }
1355       else if (!int_fits_type_p (expr, c_common_unsigned_type (type)))
1356         warning (OPT_Woverflow,
1357                  "overflow in implicit constant conversion");
1358       /* No warning for converting 0x80000000 to int.  */
1359       else if (pedantic
1360                && (TREE_CODE (TREE_TYPE (expr)) != INTEGER_TYPE
1361                    || TYPE_PRECISION (TREE_TYPE (expr))
1362                    != TYPE_PRECISION (type)))
1363         warning (OPT_Woverflow,
1364                  "overflow in implicit constant conversion");
1365
1366       else
1367         conversion_warning (type, expr);
1368     }
1369   else if ((TREE_CODE (result) == INTEGER_CST
1370             || TREE_CODE (result) == FIXED_CST) && TREE_OVERFLOW (result))
1371     warning (OPT_Woverflow,
1372              "overflow in implicit constant conversion");
1373   else
1374     conversion_warning (type, expr);
1375 }
1376
1377
1378 /* Convert EXPR to TYPE, warning about conversion problems with constants.
1379    Invoke this function on every expression that is converted implicitly,
1380    i.e. because of language rules and not because of an explicit cast.  */
1381
1382 tree
1383 convert_and_check (tree type, tree expr)
1384 {
1385   tree result;
1386
1387   if (TREE_TYPE (expr) == type)
1388     return expr;
1389
1390   result = convert (type, expr);
1391
1392   if (!skip_evaluation && !TREE_OVERFLOW_P (expr) && result != error_mark_node)
1393     warnings_for_convert_and_check (type, expr, result);
1394
1395   return result;
1396 }
1397 \f
1398 /* A node in a list that describes references to variables (EXPR), which are
1399    either read accesses if WRITER is zero, or write accesses, in which case
1400    WRITER is the parent of EXPR.  */
1401 struct tlist
1402 {
1403   struct tlist *next;
1404   tree expr, writer;
1405 };
1406
1407 /* Used to implement a cache the results of a call to verify_tree.  We only
1408    use this for SAVE_EXPRs.  */
1409 struct tlist_cache
1410 {
1411   struct tlist_cache *next;
1412   struct tlist *cache_before_sp;
1413   struct tlist *cache_after_sp;
1414   tree expr;
1415 };
1416
1417 /* Obstack to use when allocating tlist structures, and corresponding
1418    firstobj.  */
1419 static struct obstack tlist_obstack;
1420 static char *tlist_firstobj = 0;
1421
1422 /* Keep track of the identifiers we've warned about, so we can avoid duplicate
1423    warnings.  */
1424 static struct tlist *warned_ids;
1425 /* SAVE_EXPRs need special treatment.  We process them only once and then
1426    cache the results.  */
1427 static struct tlist_cache *save_expr_cache;
1428
1429 static void add_tlist (struct tlist **, struct tlist *, tree, int);
1430 static void merge_tlist (struct tlist **, struct tlist *, int);
1431 static void verify_tree (tree, struct tlist **, struct tlist **, tree);
1432 static int warning_candidate_p (tree);
1433 static void warn_for_collisions (struct tlist *);
1434 static void warn_for_collisions_1 (tree, tree, struct tlist *, int);
1435 static struct tlist *new_tlist (struct tlist *, tree, tree);
1436
1437 /* Create a new struct tlist and fill in its fields.  */
1438 static struct tlist *
1439 new_tlist (struct tlist *next, tree t, tree writer)
1440 {
1441   struct tlist *l;
1442   l = XOBNEW (&tlist_obstack, struct tlist);
1443   l->next = next;
1444   l->expr = t;
1445   l->writer = writer;
1446   return l;
1447 }
1448
1449 /* Add duplicates of the nodes found in ADD to the list *TO.  If EXCLUDE_WRITER
1450    is nonnull, we ignore any node we find which has a writer equal to it.  */
1451
1452 static void
1453 add_tlist (struct tlist **to, struct tlist *add, tree exclude_writer, int copy)
1454 {
1455   while (add)
1456     {
1457       struct tlist *next = add->next;
1458       if (!copy)
1459         add->next = *to;
1460       if (!exclude_writer || add->writer != exclude_writer)
1461         *to = copy ? new_tlist (*to, add->expr, add->writer) : add;
1462       add = next;
1463     }
1464 }
1465
1466 /* Merge the nodes of ADD into TO.  This merging process is done so that for
1467    each variable that already exists in TO, no new node is added; however if
1468    there is a write access recorded in ADD, and an occurrence on TO is only
1469    a read access, then the occurrence in TO will be modified to record the
1470    write.  */
1471
1472 static void
1473 merge_tlist (struct tlist **to, struct tlist *add, int copy)
1474 {
1475   struct tlist **end = to;
1476
1477   while (*end)
1478     end = &(*end)->next;
1479
1480   while (add)
1481     {
1482       int found = 0;
1483       struct tlist *tmp2;
1484       struct tlist *next = add->next;
1485
1486       for (tmp2 = *to; tmp2; tmp2 = tmp2->next)
1487         if (tmp2->expr == add->expr)
1488           {
1489             found = 1;
1490             if (!tmp2->writer)
1491               tmp2->writer = add->writer;
1492           }
1493       if (!found)
1494         {
1495           *end = copy ? add : new_tlist (NULL, add->expr, add->writer);
1496           end = &(*end)->next;
1497           *end = 0;
1498         }
1499       add = next;
1500     }
1501 }
1502
1503 /* WRITTEN is a variable, WRITER is its parent.  Warn if any of the variable
1504    references in list LIST conflict with it, excluding reads if ONLY writers
1505    is nonzero.  */
1506
1507 static void
1508 warn_for_collisions_1 (tree written, tree writer, struct tlist *list,
1509                        int only_writes)
1510 {
1511   struct tlist *tmp;
1512
1513   /* Avoid duplicate warnings.  */
1514   for (tmp = warned_ids; tmp; tmp = tmp->next)
1515     if (tmp->expr == written)
1516       return;
1517
1518   while (list)
1519     {
1520       if (list->expr == written
1521           && list->writer != writer
1522           && (!only_writes || list->writer)
1523           && DECL_NAME (list->expr))
1524         {
1525           warned_ids = new_tlist (warned_ids, written, NULL_TREE);
1526           warning (0, "operation on %qE may be undefined", list->expr);
1527         }
1528       list = list->next;
1529     }
1530 }
1531
1532 /* Given a list LIST of references to variables, find whether any of these
1533    can cause conflicts due to missing sequence points.  */
1534
1535 static void
1536 warn_for_collisions (struct tlist *list)
1537 {
1538   struct tlist *tmp;
1539
1540   for (tmp = list; tmp; tmp = tmp->next)
1541     {
1542       if (tmp->writer)
1543         warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0);
1544     }
1545 }
1546
1547 /* Return nonzero if X is a tree that can be verified by the sequence point
1548    warnings.  */
1549 static int
1550 warning_candidate_p (tree x)
1551 {
1552   return TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == PARM_DECL;
1553 }
1554
1555 /* Walk the tree X, and record accesses to variables.  If X is written by the
1556    parent tree, WRITER is the parent.
1557    We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP.  If this
1558    expression or its only operand forces a sequence point, then everything up
1559    to the sequence point is stored in PBEFORE_SP.  Everything else gets stored
1560    in PNO_SP.
1561    Once we return, we will have emitted warnings if any subexpression before
1562    such a sequence point could be undefined.  On a higher level, however, the
1563    sequence point may not be relevant, and we'll merge the two lists.
1564
1565    Example: (b++, a) + b;
1566    The call that processes the COMPOUND_EXPR will store the increment of B
1567    in PBEFORE_SP, and the use of A in PNO_SP.  The higher-level call that
1568    processes the PLUS_EXPR will need to merge the two lists so that
1569    eventually, all accesses end up on the same list (and we'll warn about the
1570    unordered subexpressions b++ and b.
1571
1572    A note on merging.  If we modify the former example so that our expression
1573    becomes
1574      (b++, b) + a
1575    care must be taken not simply to add all three expressions into the final
1576    PNO_SP list.  The function merge_tlist takes care of that by merging the
1577    before-SP list of the COMPOUND_EXPR into its after-SP list in a special
1578    way, so that no more than one access to B is recorded.  */
1579
1580 static void
1581 verify_tree (tree x, struct tlist **pbefore_sp, struct tlist **pno_sp,
1582              tree writer)
1583 {
1584   struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3;
1585   enum tree_code code;
1586   enum tree_code_class cl;
1587
1588   /* X may be NULL if it is the operand of an empty statement expression
1589      ({ }).  */
1590   if (x == NULL)
1591     return;
1592
1593  restart:
1594   code = TREE_CODE (x);
1595   cl = TREE_CODE_CLASS (code);
1596
1597   if (warning_candidate_p (x))
1598     {
1599       *pno_sp = new_tlist (*pno_sp, x, writer);
1600       return;
1601     }
1602
1603   switch (code)
1604     {
1605     case CONSTRUCTOR:
1606       return;
1607
1608     case COMPOUND_EXPR:
1609     case TRUTH_ANDIF_EXPR:
1610     case TRUTH_ORIF_EXPR:
1611       tmp_before = tmp_nosp = tmp_list3 = 0;
1612       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1613       warn_for_collisions (tmp_nosp);
1614       merge_tlist (pbefore_sp, tmp_before, 0);
1615       merge_tlist (pbefore_sp, tmp_nosp, 0);
1616       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE);
1617       merge_tlist (pbefore_sp, tmp_list3, 0);
1618       return;
1619
1620     case COND_EXPR:
1621       tmp_before = tmp_list2 = 0;
1622       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE);
1623       warn_for_collisions (tmp_list2);
1624       merge_tlist (pbefore_sp, tmp_before, 0);
1625       merge_tlist (pbefore_sp, tmp_list2, 1);
1626
1627       tmp_list3 = tmp_nosp = 0;
1628       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE);
1629       warn_for_collisions (tmp_nosp);
1630       merge_tlist (pbefore_sp, tmp_list3, 0);
1631
1632       tmp_list3 = tmp_list2 = 0;
1633       verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE);
1634       warn_for_collisions (tmp_list2);
1635       merge_tlist (pbefore_sp, tmp_list3, 0);
1636       /* Rather than add both tmp_nosp and tmp_list2, we have to merge the
1637          two first, to avoid warning for (a ? b++ : b++).  */
1638       merge_tlist (&tmp_nosp, tmp_list2, 0);
1639       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1640       return;
1641
1642     case PREDECREMENT_EXPR:
1643     case PREINCREMENT_EXPR:
1644     case POSTDECREMENT_EXPR:
1645     case POSTINCREMENT_EXPR:
1646       verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x);
1647       return;
1648
1649     case MODIFY_EXPR:
1650       tmp_before = tmp_nosp = tmp_list3 = 0;
1651       verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE);
1652       verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x);
1653       /* Expressions inside the LHS are not ordered wrt. the sequence points
1654          in the RHS.  Example:
1655            *a = (a++, 2)
1656          Despite the fact that the modification of "a" is in the before_sp
1657          list (tmp_before), it conflicts with the use of "a" in the LHS.
1658          We can handle this by adding the contents of tmp_list3
1659          to those of tmp_before, and redoing the collision warnings for that
1660          list.  */
1661       add_tlist (&tmp_before, tmp_list3, x, 1);
1662       warn_for_collisions (tmp_before);
1663       /* Exclude the LHS itself here; we first have to merge it into the
1664          tmp_nosp list.  This is done to avoid warning for "a = a"; if we
1665          didn't exclude the LHS, we'd get it twice, once as a read and once
1666          as a write.  */
1667       add_tlist (pno_sp, tmp_list3, x, 0);
1668       warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1);
1669
1670       merge_tlist (pbefore_sp, tmp_before, 0);
1671       if (warning_candidate_p (TREE_OPERAND (x, 0)))
1672         merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0);
1673       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1);
1674       return;
1675
1676     case CALL_EXPR:
1677       /* We need to warn about conflicts among arguments and conflicts between
1678          args and the function address.  Side effects of the function address,
1679          however, are not ordered by the sequence point of the call.  */
1680       {
1681         call_expr_arg_iterator iter;
1682         tree arg;
1683         tmp_before = tmp_nosp = 0;
1684         verify_tree (CALL_EXPR_FN (x), &tmp_before, &tmp_nosp, NULL_TREE);
1685         FOR_EACH_CALL_EXPR_ARG (arg, iter, x)
1686           {
1687             tmp_list2 = tmp_list3 = 0;
1688             verify_tree (arg, &tmp_list2, &tmp_list3, NULL_TREE);
1689             merge_tlist (&tmp_list3, tmp_list2, 0);
1690             add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0);
1691           }
1692         add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0);
1693         warn_for_collisions (tmp_before);
1694         add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0);
1695         return;
1696       }
1697
1698     case TREE_LIST:
1699       /* Scan all the list, e.g. indices of multi dimensional array.  */
1700       while (x)
1701         {
1702           tmp_before = tmp_nosp = 0;
1703           verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE);
1704           merge_tlist (&tmp_nosp, tmp_before, 0);
1705           add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1706           x = TREE_CHAIN (x);
1707         }
1708       return;
1709
1710     case SAVE_EXPR:
1711       {
1712         struct tlist_cache *t;
1713         for (t = save_expr_cache; t; t = t->next)
1714           if (t->expr == x)
1715             break;
1716
1717         if (!t)
1718           {
1719             t = XOBNEW (&tlist_obstack, struct tlist_cache);
1720             t->next = save_expr_cache;
1721             t->expr = x;
1722             save_expr_cache = t;
1723
1724             tmp_before = tmp_nosp = 0;
1725             verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1726             warn_for_collisions (tmp_nosp);
1727
1728             tmp_list3 = 0;
1729             while (tmp_nosp)
1730               {
1731                 struct tlist *t = tmp_nosp;
1732                 tmp_nosp = t->next;
1733                 merge_tlist (&tmp_list3, t, 0);
1734               }
1735             t->cache_before_sp = tmp_before;
1736             t->cache_after_sp = tmp_list3;
1737           }
1738         merge_tlist (pbefore_sp, t->cache_before_sp, 1);
1739         add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1);
1740         return;
1741       }
1742
1743     default:
1744       /* For other expressions, simply recurse on their operands.
1745          Manual tail recursion for unary expressions.
1746          Other non-expressions need not be processed.  */
1747       if (cl == tcc_unary)
1748         {
1749           x = TREE_OPERAND (x, 0);
1750           writer = 0;
1751           goto restart;
1752         }
1753       else if (IS_EXPR_CODE_CLASS (cl))
1754         {
1755           int lp;
1756           int max = TREE_OPERAND_LENGTH (x);
1757           for (lp = 0; lp < max; lp++)
1758             {
1759               tmp_before = tmp_nosp = 0;
1760               verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, 0);
1761               merge_tlist (&tmp_nosp, tmp_before, 0);
1762               add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1763             }
1764         }
1765       return;
1766     }
1767 }
1768
1769 /* Try to warn for undefined behavior in EXPR due to missing sequence
1770    points.  */
1771
1772 void
1773 verify_sequence_points (tree expr)
1774 {
1775   struct tlist *before_sp = 0, *after_sp = 0;
1776
1777   warned_ids = 0;
1778   save_expr_cache = 0;
1779   if (tlist_firstobj == 0)
1780     {
1781       gcc_obstack_init (&tlist_obstack);
1782       tlist_firstobj = (char *) obstack_alloc (&tlist_obstack, 0);
1783     }
1784
1785   verify_tree (expr, &before_sp, &after_sp, 0);
1786   warn_for_collisions (after_sp);
1787   obstack_free (&tlist_obstack, tlist_firstobj);
1788 }
1789 \f
1790 /* Validate the expression after `case' and apply default promotions.  */
1791
1792 static tree
1793 check_case_value (tree value)
1794 {
1795   if (value == NULL_TREE)
1796     return value;
1797
1798   /* ??? Can we ever get nops here for a valid case value?  We
1799      shouldn't for C.  */
1800   STRIP_TYPE_NOPS (value);
1801   /* In C++, the following is allowed:
1802
1803        const int i = 3;
1804        switch (...) { case i: ... }
1805
1806      So, we try to reduce the VALUE to a constant that way.  */
1807   if (c_dialect_cxx ())
1808     {
1809       value = decl_constant_value (value);
1810       STRIP_TYPE_NOPS (value);
1811       value = fold (value);
1812     }
1813
1814   if (TREE_CODE (value) == INTEGER_CST)
1815     /* Promote char or short to int.  */
1816     value = perform_integral_promotions (value);
1817   else if (value != error_mark_node)
1818     {
1819       error ("case label does not reduce to an integer constant");
1820       value = error_mark_node;
1821     }
1822
1823   constant_expression_warning (value);
1824
1825   return value;
1826 }
1827 \f
1828 /* See if the case values LOW and HIGH are in the range of the original
1829    type (i.e. before the default conversion to int) of the switch testing
1830    expression.
1831    TYPE is the promoted type of the testing expression, and ORIG_TYPE is
1832    the type before promoting it.  CASE_LOW_P is a pointer to the lower
1833    bound of the case label, and CASE_HIGH_P is the upper bound or NULL
1834    if the case is not a case range.
1835    The caller has to make sure that we are not called with NULL for
1836    CASE_LOW_P (i.e. the default case).
1837    Returns true if the case label is in range of ORIG_TYPE (saturated or
1838    untouched) or false if the label is out of range.  */
1839
1840 static bool
1841 check_case_bounds (tree type, tree orig_type,
1842                    tree *case_low_p, tree *case_high_p)
1843 {
1844   tree min_value, max_value;
1845   tree case_low = *case_low_p;
1846   tree case_high = case_high_p ? *case_high_p : case_low;
1847
1848   /* If there was a problem with the original type, do nothing.  */
1849   if (orig_type == error_mark_node)
1850     return true;
1851
1852   min_value = TYPE_MIN_VALUE (orig_type);
1853   max_value = TYPE_MAX_VALUE (orig_type);
1854
1855   /* Case label is less than minimum for type.  */
1856   if (tree_int_cst_compare (case_low, min_value) < 0
1857       && tree_int_cst_compare (case_high, min_value) < 0)
1858     {
1859       warning (0, "case label value is less than minimum value for type");
1860       return false;
1861     }
1862
1863   /* Case value is greater than maximum for type.  */
1864   if (tree_int_cst_compare (case_low, max_value) > 0
1865       && tree_int_cst_compare (case_high, max_value) > 0)
1866     {
1867       warning (0, "case label value exceeds maximum value for type");
1868       return false;
1869     }
1870
1871   /* Saturate lower case label value to minimum.  */
1872   if (tree_int_cst_compare (case_high, min_value) >= 0
1873       && tree_int_cst_compare (case_low, min_value) < 0)
1874     {
1875       warning (0, "lower value in case label range"
1876                " less than minimum value for type");
1877       case_low = min_value;
1878     }
1879
1880   /* Saturate upper case label value to maximum.  */
1881   if (tree_int_cst_compare (case_low, max_value) <= 0
1882       && tree_int_cst_compare (case_high, max_value) > 0)
1883     {
1884       warning (0, "upper value in case label range"
1885                " exceeds maximum value for type");
1886       case_high = max_value;
1887     }
1888
1889   if (*case_low_p != case_low)
1890     *case_low_p = convert (type, case_low);
1891   if (case_high_p && *case_high_p != case_high)
1892     *case_high_p = convert (type, case_high);
1893
1894   return true;
1895 }
1896 \f
1897 /* Return an integer type with BITS bits of precision,
1898    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
1899
1900 tree
1901 c_common_type_for_size (unsigned int bits, int unsignedp)
1902 {
1903   if (bits == TYPE_PRECISION (integer_type_node))
1904     return unsignedp ? unsigned_type_node : integer_type_node;
1905
1906   if (bits == TYPE_PRECISION (signed_char_type_node))
1907     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1908
1909   if (bits == TYPE_PRECISION (short_integer_type_node))
1910     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1911
1912   if (bits == TYPE_PRECISION (long_integer_type_node))
1913     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1914
1915   if (bits == TYPE_PRECISION (long_long_integer_type_node))
1916     return (unsignedp ? long_long_unsigned_type_node
1917             : long_long_integer_type_node);
1918
1919   if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
1920     return (unsignedp ? widest_unsigned_literal_type_node
1921             : widest_integer_literal_type_node);
1922
1923   if (bits <= TYPE_PRECISION (intQI_type_node))
1924     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1925
1926   if (bits <= TYPE_PRECISION (intHI_type_node))
1927     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1928
1929   if (bits <= TYPE_PRECISION (intSI_type_node))
1930     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1931
1932   if (bits <= TYPE_PRECISION (intDI_type_node))
1933     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1934
1935   return 0;
1936 }
1937
1938 /* Return a fixed-point type that has at least IBIT ibits and FBIT fbits
1939    that is unsigned if UNSIGNEDP is nonzero, otherwise signed;
1940    and saturating if SATP is nonzero, otherwise not saturating.  */
1941
1942 tree
1943 c_common_fixed_point_type_for_size (unsigned int ibit, unsigned int fbit,
1944                                     int unsignedp, int satp)
1945 {
1946   enum machine_mode mode;
1947   if (ibit == 0)
1948     mode = unsignedp ? UQQmode : QQmode;
1949   else
1950     mode = unsignedp ? UHAmode : HAmode;
1951
1952   for (; mode != VOIDmode; mode = GET_MODE_WIDER_MODE (mode))
1953     if (GET_MODE_IBIT (mode) >= ibit && GET_MODE_FBIT (mode) >= fbit)
1954       break;
1955
1956   if (mode == VOIDmode || !targetm.scalar_mode_supported_p (mode))
1957     {
1958       sorry ("GCC cannot support operators with integer types and "
1959              "fixed-point types that have too many integral and "
1960              "fractional bits together");
1961       return 0;
1962     }
1963
1964   return c_common_type_for_mode (mode, satp);
1965 }
1966
1967 /* Used for communication between c_common_type_for_mode and
1968    c_register_builtin_type.  */
1969 static GTY(()) tree registered_builtin_types;
1970
1971 /* Return a data type that has machine mode MODE.
1972    If the mode is an integer,
1973    then UNSIGNEDP selects between signed and unsigned types.
1974    If the mode is a fixed-point mode,
1975    then UNSIGNEDP selects between saturating and nonsaturating types.  */
1976
1977 tree
1978 c_common_type_for_mode (enum machine_mode mode, int unsignedp)
1979 {
1980   tree t;
1981
1982   if (mode == TYPE_MODE (integer_type_node))
1983     return unsignedp ? unsigned_type_node : integer_type_node;
1984
1985   if (mode == TYPE_MODE (signed_char_type_node))
1986     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1987
1988   if (mode == TYPE_MODE (short_integer_type_node))
1989     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1990
1991   if (mode == TYPE_MODE (long_integer_type_node))
1992     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1993
1994   if (mode == TYPE_MODE (long_long_integer_type_node))
1995     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
1996
1997   if (mode == TYPE_MODE (widest_integer_literal_type_node))
1998     return unsignedp ? widest_unsigned_literal_type_node
1999                      : widest_integer_literal_type_node;
2000
2001   if (mode == QImode)
2002     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2003
2004   if (mode == HImode)
2005     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2006
2007   if (mode == SImode)
2008     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2009
2010   if (mode == DImode)
2011     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2012
2013 #if HOST_BITS_PER_WIDE_INT >= 64
2014   if (mode == TYPE_MODE (intTI_type_node))
2015     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
2016 #endif
2017
2018   if (mode == TYPE_MODE (float_type_node))
2019     return float_type_node;
2020
2021   if (mode == TYPE_MODE (double_type_node))
2022     return double_type_node;
2023
2024   if (mode == TYPE_MODE (long_double_type_node))
2025     return long_double_type_node;
2026
2027   if (mode == TYPE_MODE (void_type_node))
2028     return void_type_node;
2029
2030   if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
2031     return (unsignedp
2032             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2033             : make_signed_type (GET_MODE_PRECISION (mode)));
2034
2035   if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
2036     return (unsignedp
2037             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2038             : make_signed_type (GET_MODE_PRECISION (mode)));
2039
2040   if (COMPLEX_MODE_P (mode))
2041     {
2042       enum machine_mode inner_mode;
2043       tree inner_type;
2044
2045       if (mode == TYPE_MODE (complex_float_type_node))
2046         return complex_float_type_node;
2047       if (mode == TYPE_MODE (complex_double_type_node))
2048         return complex_double_type_node;
2049       if (mode == TYPE_MODE (complex_long_double_type_node))
2050         return complex_long_double_type_node;
2051
2052       if (mode == TYPE_MODE (complex_integer_type_node) && !unsignedp)
2053         return complex_integer_type_node;
2054
2055       inner_mode = GET_MODE_INNER (mode);
2056       inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2057       if (inner_type != NULL_TREE)
2058         return build_complex_type (inner_type);
2059     }
2060   else if (VECTOR_MODE_P (mode))
2061     {
2062       enum machine_mode inner_mode = GET_MODE_INNER (mode);
2063       tree inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2064       if (inner_type != NULL_TREE)
2065         return build_vector_type_for_mode (inner_type, mode);
2066     }
2067
2068   if (mode == TYPE_MODE (dfloat32_type_node))
2069     return dfloat32_type_node;
2070   if (mode == TYPE_MODE (dfloat64_type_node))
2071     return dfloat64_type_node;
2072   if (mode == TYPE_MODE (dfloat128_type_node))
2073     return dfloat128_type_node;
2074
2075   if (ALL_SCALAR_FIXED_POINT_MODE_P (mode))
2076     {
2077       if (mode == TYPE_MODE (short_fract_type_node))
2078         return unsignedp ? sat_short_fract_type_node : short_fract_type_node;
2079       if (mode == TYPE_MODE (fract_type_node))
2080         return unsignedp ? sat_fract_type_node : fract_type_node;
2081       if (mode == TYPE_MODE (long_fract_type_node))
2082         return unsignedp ? sat_long_fract_type_node : long_fract_type_node;
2083       if (mode == TYPE_MODE (long_long_fract_type_node))
2084         return unsignedp ? sat_long_long_fract_type_node
2085                          : long_long_fract_type_node;
2086
2087       if (mode == TYPE_MODE (unsigned_short_fract_type_node))
2088         return unsignedp ? sat_unsigned_short_fract_type_node
2089                          : unsigned_short_fract_type_node;
2090       if (mode == TYPE_MODE (unsigned_fract_type_node))
2091         return unsignedp ? sat_unsigned_fract_type_node
2092                          : unsigned_fract_type_node;
2093       if (mode == TYPE_MODE (unsigned_long_fract_type_node))
2094         return unsignedp ? sat_unsigned_long_fract_type_node
2095                          : unsigned_long_fract_type_node;
2096       if (mode == TYPE_MODE (unsigned_long_long_fract_type_node))
2097         return unsignedp ? sat_unsigned_long_long_fract_type_node
2098                          : unsigned_long_long_fract_type_node;
2099
2100       if (mode == TYPE_MODE (short_accum_type_node))
2101         return unsignedp ? sat_short_accum_type_node : short_accum_type_node;
2102       if (mode == TYPE_MODE (accum_type_node))
2103         return unsignedp ? sat_accum_type_node : accum_type_node;
2104       if (mode == TYPE_MODE (long_accum_type_node))
2105         return unsignedp ? sat_long_accum_type_node : long_accum_type_node;
2106       if (mode == TYPE_MODE (long_long_accum_type_node))
2107         return unsignedp ? sat_long_long_accum_type_node
2108                          : long_long_accum_type_node;
2109
2110       if (mode == TYPE_MODE (unsigned_short_accum_type_node))
2111         return unsignedp ? sat_unsigned_short_accum_type_node
2112                          : unsigned_short_accum_type_node;
2113       if (mode == TYPE_MODE (unsigned_accum_type_node))
2114         return unsignedp ? sat_unsigned_accum_type_node
2115                          : unsigned_accum_type_node;
2116       if (mode == TYPE_MODE (unsigned_long_accum_type_node))
2117         return unsignedp ? sat_unsigned_long_accum_type_node
2118                          : unsigned_long_accum_type_node;
2119       if (mode == TYPE_MODE (unsigned_long_long_accum_type_node))
2120         return unsignedp ? sat_unsigned_long_long_accum_type_node
2121                          : unsigned_long_long_accum_type_node;
2122
2123       if (mode == QQmode)
2124         return unsignedp ? sat_qq_type_node : qq_type_node;
2125       if (mode == HQmode)
2126         return unsignedp ? sat_hq_type_node : hq_type_node;
2127       if (mode == SQmode)
2128         return unsignedp ? sat_sq_type_node : sq_type_node;
2129       if (mode == DQmode)
2130         return unsignedp ? sat_dq_type_node : dq_type_node;
2131       if (mode == TQmode)
2132         return unsignedp ? sat_tq_type_node : tq_type_node;
2133
2134       if (mode == UQQmode)
2135         return unsignedp ? sat_uqq_type_node : uqq_type_node;
2136       if (mode == UHQmode)
2137         return unsignedp ? sat_uhq_type_node : uhq_type_node;
2138       if (mode == USQmode)
2139         return unsignedp ? sat_usq_type_node : usq_type_node;
2140       if (mode == UDQmode)
2141         return unsignedp ? sat_udq_type_node : udq_type_node;
2142       if (mode == UTQmode)
2143         return unsignedp ? sat_utq_type_node : utq_type_node;
2144
2145       if (mode == HAmode)
2146         return unsignedp ? sat_ha_type_node : ha_type_node;
2147       if (mode == SAmode)
2148         return unsignedp ? sat_sa_type_node : sa_type_node;
2149       if (mode == DAmode)
2150         return unsignedp ? sat_da_type_node : da_type_node;
2151       if (mode == TAmode)
2152         return unsignedp ? sat_ta_type_node : ta_type_node;
2153
2154       if (mode == UHAmode)
2155         return unsignedp ? sat_uha_type_node : uha_type_node;
2156       if (mode == USAmode)
2157         return unsignedp ? sat_usa_type_node : usa_type_node;
2158       if (mode == UDAmode)
2159         return unsignedp ? sat_uda_type_node : uda_type_node;
2160       if (mode == UTAmode)
2161         return unsignedp ? sat_uta_type_node : uta_type_node;
2162     }
2163
2164   for (t = registered_builtin_types; t; t = TREE_CHAIN (t))
2165     if (TYPE_MODE (TREE_VALUE (t)) == mode)
2166       return TREE_VALUE (t);
2167
2168   return 0;
2169 }
2170
2171 tree
2172 c_common_unsigned_type (tree type)
2173 {
2174   return c_common_signed_or_unsigned_type (1, type);
2175 }
2176
2177 /* Return a signed type the same as TYPE in other respects.  */
2178
2179 tree
2180 c_common_signed_type (tree type)
2181 {
2182   return c_common_signed_or_unsigned_type (0, type);
2183 }
2184
2185 /* Return a type the same as TYPE except unsigned or
2186    signed according to UNSIGNEDP.  */
2187
2188 tree
2189 c_common_signed_or_unsigned_type (int unsignedp, tree type)
2190 {
2191   tree type1;
2192
2193   /* This block of code emulates the behavior of the old
2194      c_common_unsigned_type. In particular, it returns
2195      long_unsigned_type_node if passed a long, even when a int would
2196      have the same size. This is necessary for warnings to work
2197      correctly in archs where sizeof(int) == sizeof(long) */
2198
2199   type1 = TYPE_MAIN_VARIANT (type);
2200   if (type1 == signed_char_type_node || type1 == char_type_node || type1 == unsigned_char_type_node)
2201     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2202   if (type1 == integer_type_node || type1 == unsigned_type_node)
2203     return unsignedp ? unsigned_type_node : integer_type_node;
2204   if (type1 == short_integer_type_node || type1 == short_unsigned_type_node)
2205     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2206   if (type1 == long_integer_type_node || type1 == long_unsigned_type_node)
2207     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2208   if (type1 == long_long_integer_type_node || type1 == long_long_unsigned_type_node)
2209     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
2210   if (type1 == widest_integer_literal_type_node || type1 == widest_unsigned_literal_type_node)
2211     return unsignedp ? widest_unsigned_literal_type_node : widest_integer_literal_type_node;
2212 #if HOST_BITS_PER_WIDE_INT >= 64
2213   if (type1 == intTI_type_node || type1 == unsigned_intTI_type_node)
2214     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
2215 #endif
2216   if (type1 == intDI_type_node || type1 == unsigned_intDI_type_node)
2217     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2218   if (type1 == intSI_type_node || type1 == unsigned_intSI_type_node)
2219     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2220   if (type1 == intHI_type_node || type1 == unsigned_intHI_type_node)
2221     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2222   if (type1 == intQI_type_node || type1 == unsigned_intQI_type_node)
2223     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2224
2225 #define C_COMMON_FIXED_TYPES(SAT,NAME) \
2226   if (type1 == SAT ## short_ ## NAME ## _type_node \
2227       || type1 == SAT ## unsigned_short_ ## NAME ## _type_node) \
2228     return unsignedp ? SAT ## unsigned_short_ ## NAME ## _type_node \
2229                      : SAT ## short_ ## NAME ## _type_node; \
2230   if (type1 == SAT ## NAME ## _type_node \
2231       || type1 == SAT ## unsigned_ ## NAME ## _type_node) \
2232     return unsignedp ? SAT ## unsigned_ ## NAME ## _type_node \
2233                      : SAT ## NAME ## _type_node; \
2234   if (type1 == SAT ## long_ ## NAME ## _type_node \
2235       || type1 == SAT ## unsigned_long_ ## NAME ## _type_node) \
2236     return unsignedp ? SAT ## unsigned_long_ ## NAME ## _type_node \
2237                      : SAT ## long_ ## NAME ## _type_node; \
2238   if (type1 == SAT ## long_long_ ## NAME ## _type_node \
2239       || type1 == SAT ## unsigned_long_long_ ## NAME ## _type_node) \
2240     return unsignedp ? SAT ## unsigned_long_long_ ## NAME ## _type_node \
2241                      : SAT ## long_long_ ## NAME ## _type_node;
2242
2243 #define C_COMMON_FIXED_MODE_TYPES(SAT,NAME) \
2244   if (type1 == SAT ## NAME ## _type_node \
2245       || type1 == SAT ## u ## NAME ## _type_node) \
2246     return unsignedp ? SAT ## u ## NAME ## _type_node \
2247                      : SAT ## NAME ## _type_node;
2248
2249   C_COMMON_FIXED_TYPES (, fract);
2250   C_COMMON_FIXED_TYPES (sat_, fract);
2251   C_COMMON_FIXED_TYPES (, accum);
2252   C_COMMON_FIXED_TYPES (sat_, accum);
2253
2254   C_COMMON_FIXED_MODE_TYPES (, qq);
2255   C_COMMON_FIXED_MODE_TYPES (, hq);
2256   C_COMMON_FIXED_MODE_TYPES (, sq);
2257   C_COMMON_FIXED_MODE_TYPES (, dq);
2258   C_COMMON_FIXED_MODE_TYPES (, tq);
2259   C_COMMON_FIXED_MODE_TYPES (sat_, qq);
2260   C_COMMON_FIXED_MODE_TYPES (sat_, hq);
2261   C_COMMON_FIXED_MODE_TYPES (sat_, sq);
2262   C_COMMON_FIXED_MODE_TYPES (sat_, dq);
2263   C_COMMON_FIXED_MODE_TYPES (sat_, tq);
2264   C_COMMON_FIXED_MODE_TYPES (, ha);
2265   C_COMMON_FIXED_MODE_TYPES (, sa);
2266   C_COMMON_FIXED_MODE_TYPES (, da);
2267   C_COMMON_FIXED_MODE_TYPES (, ta);
2268   C_COMMON_FIXED_MODE_TYPES (sat_, ha);
2269   C_COMMON_FIXED_MODE_TYPES (sat_, sa);
2270   C_COMMON_FIXED_MODE_TYPES (sat_, da);
2271   C_COMMON_FIXED_MODE_TYPES (sat_, ta);
2272
2273   /* For ENUMERAL_TYPEs in C++, must check the mode of the types, not
2274      the precision; they have precision set to match their range, but
2275      may use a wider mode to match an ABI.  If we change modes, we may
2276      wind up with bad conversions.  For INTEGER_TYPEs in C, must check
2277      the precision as well, so as to yield correct results for
2278      bit-field types.  C++ does not have these separate bit-field
2279      types, and producing a signed or unsigned variant of an
2280      ENUMERAL_TYPE may cause other problems as well.  */
2281
2282   if (!INTEGRAL_TYPE_P (type)
2283       || TYPE_UNSIGNED (type) == unsignedp)
2284     return type;
2285
2286 #define TYPE_OK(node)                                                       \
2287   (TYPE_MODE (type) == TYPE_MODE (node)                                     \
2288    && (c_dialect_cxx () || TYPE_PRECISION (type) == TYPE_PRECISION (node)))
2289   if (TYPE_OK (signed_char_type_node))
2290     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2291   if (TYPE_OK (integer_type_node))
2292     return unsignedp ? unsigned_type_node : integer_type_node;
2293   if (TYPE_OK (short_integer_type_node))
2294     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2295   if (TYPE_OK (long_integer_type_node))
2296     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2297   if (TYPE_OK (long_long_integer_type_node))
2298     return (unsignedp ? long_long_unsigned_type_node
2299             : long_long_integer_type_node);
2300   if (TYPE_OK (widest_integer_literal_type_node))
2301     return (unsignedp ? widest_unsigned_literal_type_node
2302             : widest_integer_literal_type_node);
2303
2304 #if HOST_BITS_PER_WIDE_INT >= 64
2305   if (TYPE_OK (intTI_type_node))
2306     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
2307 #endif
2308   if (TYPE_OK (intDI_type_node))
2309     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2310   if (TYPE_OK (intSI_type_node))
2311     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2312   if (TYPE_OK (intHI_type_node))
2313     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2314   if (TYPE_OK (intQI_type_node))
2315     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2316 #undef TYPE_OK
2317
2318   if (c_dialect_cxx ())
2319     return type;
2320   else
2321     return build_nonstandard_integer_type (TYPE_PRECISION (type), unsignedp);
2322 }
2323
2324 /* Build a bit-field integer type for the given WIDTH and UNSIGNEDP.  */
2325
2326 tree
2327 c_build_bitfield_integer_type (unsigned HOST_WIDE_INT width, int unsignedp)
2328 {
2329   /* Extended integer types of the same width as a standard type have
2330      lesser rank, so those of the same width as int promote to int or
2331      unsigned int and are valid for printf formats expecting int or
2332      unsigned int.  To avoid such special cases, avoid creating
2333      extended integer types for bit-fields if a standard integer type
2334      is available.  */
2335   if (width == TYPE_PRECISION (integer_type_node))
2336     return unsignedp ? unsigned_type_node : integer_type_node;
2337   if (width == TYPE_PRECISION (signed_char_type_node))
2338     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2339   if (width == TYPE_PRECISION (short_integer_type_node))
2340     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2341   if (width == TYPE_PRECISION (long_integer_type_node))
2342     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2343   if (width == TYPE_PRECISION (long_long_integer_type_node))
2344     return (unsignedp ? long_long_unsigned_type_node
2345             : long_long_integer_type_node);
2346   return build_nonstandard_integer_type (width, unsignedp);
2347 }
2348
2349 /* The C version of the register_builtin_type langhook.  */
2350
2351 void
2352 c_register_builtin_type (tree type, const char* name)
2353 {
2354   tree decl;
2355
2356   decl = build_decl (TYPE_DECL, get_identifier (name), type);
2357   DECL_ARTIFICIAL (decl) = 1;
2358   if (!TYPE_NAME (type))
2359     TYPE_NAME (type) = decl;
2360   pushdecl (decl);
2361
2362   registered_builtin_types = tree_cons (0, type, registered_builtin_types);
2363 }
2364
2365 \f
2366 /* Return the minimum number of bits needed to represent VALUE in a
2367    signed or unsigned type, UNSIGNEDP says which.  */
2368
2369 unsigned int
2370 min_precision (tree value, int unsignedp)
2371 {
2372   int log;
2373
2374   /* If the value is negative, compute its negative minus 1.  The latter
2375      adjustment is because the absolute value of the largest negative value
2376      is one larger than the largest positive value.  This is equivalent to
2377      a bit-wise negation, so use that operation instead.  */
2378
2379   if (tree_int_cst_sgn (value) < 0)
2380     value = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (value), value);
2381
2382   /* Return the number of bits needed, taking into account the fact
2383      that we need one more bit for a signed than unsigned type.  */
2384
2385   if (integer_zerop (value))
2386     log = 0;
2387   else
2388     log = tree_floor_log2 (value);
2389
2390   return log + 1 + !unsignedp;
2391 }
2392 \f
2393 /* Print an error message for invalid operands to arith operation
2394    CODE with TYPE0 for operand 0, and TYPE1 for operand 1.  */
2395
2396 void
2397 binary_op_error (enum tree_code code, tree type0, tree type1)
2398 {
2399   const char *opname;
2400
2401   switch (code)
2402     {
2403     case PLUS_EXPR:
2404       opname = "+"; break;
2405     case MINUS_EXPR:
2406       opname = "-"; break;
2407     case MULT_EXPR:
2408       opname = "*"; break;
2409     case MAX_EXPR:
2410       opname = "max"; break;
2411     case MIN_EXPR:
2412       opname = "min"; break;
2413     case EQ_EXPR:
2414       opname = "=="; break;
2415     case NE_EXPR:
2416       opname = "!="; break;
2417     case LE_EXPR:
2418       opname = "<="; break;
2419     case GE_EXPR:
2420       opname = ">="; break;
2421     case LT_EXPR:
2422       opname = "<"; break;
2423     case GT_EXPR:
2424       opname = ">"; break;
2425     case LSHIFT_EXPR:
2426       opname = "<<"; break;
2427     case RSHIFT_EXPR:
2428       opname = ">>"; break;
2429     case TRUNC_MOD_EXPR:
2430     case FLOOR_MOD_EXPR:
2431       opname = "%"; break;
2432     case TRUNC_DIV_EXPR:
2433     case FLOOR_DIV_EXPR:
2434       opname = "/"; break;
2435     case BIT_AND_EXPR:
2436       opname = "&"; break;
2437     case BIT_IOR_EXPR:
2438       opname = "|"; break;
2439     case TRUTH_ANDIF_EXPR:
2440       opname = "&&"; break;
2441     case TRUTH_ORIF_EXPR:
2442       opname = "||"; break;
2443     case BIT_XOR_EXPR:
2444       opname = "^"; break;
2445     default:
2446       gcc_unreachable ();
2447     }
2448   error ("invalid operands to binary %s (have %qT and %qT)", opname,
2449          type0, type1);
2450 }
2451 \f
2452 /* Subroutine of build_binary_op, used for comparison operations.
2453    See if the operands have both been converted from subword integer types
2454    and, if so, perhaps change them both back to their original type.
2455    This function is also responsible for converting the two operands
2456    to the proper common type for comparison.
2457
2458    The arguments of this function are all pointers to local variables
2459    of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
2460    RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.
2461
2462    If this function returns nonzero, it means that the comparison has
2463    a constant value.  What this function returns is an expression for
2464    that value.  */
2465
2466 tree
2467 shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr,
2468                  enum tree_code *rescode_ptr)
2469 {
2470   tree type;
2471   tree op0 = *op0_ptr;
2472   tree op1 = *op1_ptr;
2473   int unsignedp0, unsignedp1;
2474   int real1, real2;
2475   tree primop0, primop1;
2476   enum tree_code code = *rescode_ptr;
2477
2478   /* Throw away any conversions to wider types
2479      already present in the operands.  */
2480
2481   primop0 = get_narrower (op0, &unsignedp0);
2482   primop1 = get_narrower (op1, &unsignedp1);
2483
2484   /* Handle the case that OP0 does not *contain* a conversion
2485      but it *requires* conversion to FINAL_TYPE.  */
2486
2487   if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
2488     unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0));
2489   if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
2490     unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1));
2491
2492   /* If one of the operands must be floated, we cannot optimize.  */
2493   real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
2494   real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
2495
2496   /* If first arg is constant, swap the args (changing operation
2497      so value is preserved), for canonicalization.  Don't do this if
2498      the second arg is 0.  */
2499
2500   if (TREE_CONSTANT (primop0)
2501       && !integer_zerop (primop1) && !real_zerop (primop1)
2502       && !fixed_zerop (primop1))
2503     {
2504       tree tem = primop0;
2505       int temi = unsignedp0;
2506       primop0 = primop1;
2507       primop1 = tem;
2508       tem = op0;
2509       op0 = op1;
2510       op1 = tem;
2511       *op0_ptr = op0;
2512       *op1_ptr = op1;
2513       unsignedp0 = unsignedp1;
2514       unsignedp1 = temi;
2515       temi = real1;
2516       real1 = real2;
2517       real2 = temi;
2518
2519       switch (code)
2520         {
2521         case LT_EXPR:
2522           code = GT_EXPR;
2523           break;
2524         case GT_EXPR:
2525           code = LT_EXPR;
2526           break;
2527         case LE_EXPR:
2528           code = GE_EXPR;
2529           break;
2530         case GE_EXPR:
2531           code = LE_EXPR;
2532           break;
2533         default:
2534           break;
2535         }
2536       *rescode_ptr = code;
2537     }
2538
2539   /* If comparing an integer against a constant more bits wide,
2540      maybe we can deduce a value of 1 or 0 independent of the data.
2541      Or else truncate the constant now
2542      rather than extend the variable at run time.
2543
2544      This is only interesting if the constant is the wider arg.
2545      Also, it is not safe if the constant is unsigned and the
2546      variable arg is signed, since in this case the variable
2547      would be sign-extended and then regarded as unsigned.
2548      Our technique fails in this case because the lowest/highest
2549      possible unsigned results don't follow naturally from the
2550      lowest/highest possible values of the variable operand.
2551      For just EQ_EXPR and NE_EXPR there is another technique that
2552      could be used: see if the constant can be faithfully represented
2553      in the other operand's type, by truncating it and reextending it
2554      and see if that preserves the constant's value.  */
2555
2556   if (!real1 && !real2
2557       && TREE_CODE (TREE_TYPE (primop0)) != FIXED_POINT_TYPE
2558       && TREE_CODE (primop1) == INTEGER_CST
2559       && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
2560     {
2561       int min_gt, max_gt, min_lt, max_lt;
2562       tree maxval, minval;
2563       /* 1 if comparison is nominally unsigned.  */
2564       int unsignedp = TYPE_UNSIGNED (*restype_ptr);
2565       tree val;
2566
2567       type = c_common_signed_or_unsigned_type (unsignedp0,
2568                                                TREE_TYPE (primop0));
2569
2570       maxval = TYPE_MAX_VALUE (type);
2571       minval = TYPE_MIN_VALUE (type);
2572
2573       if (unsignedp && !unsignedp0)
2574         *restype_ptr = c_common_signed_type (*restype_ptr);
2575
2576       if (TREE_TYPE (primop1) != *restype_ptr)
2577         {
2578           /* Convert primop1 to target type, but do not introduce
2579              additional overflow.  We know primop1 is an int_cst.  */
2580           primop1 = force_fit_type_double (*restype_ptr,
2581                                            TREE_INT_CST_LOW (primop1),
2582                                            TREE_INT_CST_HIGH (primop1), 0,
2583                                            TREE_OVERFLOW (primop1));
2584         }
2585       if (type != *restype_ptr)
2586         {
2587           minval = convert (*restype_ptr, minval);
2588           maxval = convert (*restype_ptr, maxval);
2589         }
2590
2591       if (unsignedp && unsignedp0)
2592         {
2593           min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
2594           max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
2595           min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
2596           max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
2597         }
2598       else
2599         {
2600           min_gt = INT_CST_LT (primop1, minval);
2601           max_gt = INT_CST_LT (primop1, maxval);
2602           min_lt = INT_CST_LT (minval, primop1);
2603           max_lt = INT_CST_LT (maxval, primop1);
2604         }
2605
2606       val = 0;
2607       /* This used to be a switch, but Genix compiler can't handle that.  */
2608       if (code == NE_EXPR)
2609         {
2610           if (max_lt || min_gt)
2611             val = truthvalue_true_node;
2612         }
2613       else if (code == EQ_EXPR)
2614         {
2615           if (max_lt || min_gt)
2616             val = truthvalue_false_node;
2617         }
2618       else if (code == LT_EXPR)
2619         {
2620           if (max_lt)
2621             val = truthvalue_true_node;
2622           if (!min_lt)
2623             val = truthvalue_false_node;
2624         }
2625       else if (code == GT_EXPR)
2626         {
2627           if (min_gt)
2628             val = truthvalue_true_node;
2629           if (!max_gt)
2630             val = truthvalue_false_node;
2631         }
2632       else if (code == LE_EXPR)
2633         {
2634           if (!max_gt)
2635             val = truthvalue_true_node;
2636           if (min_gt)
2637             val = truthvalue_false_node;
2638         }
2639       else if (code == GE_EXPR)
2640         {
2641           if (!min_lt)
2642             val = truthvalue_true_node;
2643           if (max_lt)
2644             val = truthvalue_false_node;
2645         }
2646
2647       /* If primop0 was sign-extended and unsigned comparison specd,
2648          we did a signed comparison above using the signed type bounds.
2649          But the comparison we output must be unsigned.
2650
2651          Also, for inequalities, VAL is no good; but if the signed
2652          comparison had *any* fixed result, it follows that the
2653          unsigned comparison just tests the sign in reverse
2654          (positive values are LE, negative ones GE).
2655          So we can generate an unsigned comparison
2656          against an extreme value of the signed type.  */
2657
2658       if (unsignedp && !unsignedp0)
2659         {
2660           if (val != 0)
2661             switch (code)
2662               {
2663               case LT_EXPR:
2664               case GE_EXPR:
2665                 primop1 = TYPE_MIN_VALUE (type);
2666                 val = 0;
2667                 break;
2668
2669               case LE_EXPR:
2670               case GT_EXPR:
2671                 primop1 = TYPE_MAX_VALUE (type);
2672                 val = 0;
2673                 break;
2674
2675               default:
2676                 break;
2677               }
2678           type = c_common_unsigned_type (type);
2679         }
2680
2681       if (TREE_CODE (primop0) != INTEGER_CST)
2682         {
2683           if (val == truthvalue_false_node)
2684             warning (OPT_Wtype_limits, "comparison is always false due to limited range of data type");
2685           if (val == truthvalue_true_node)
2686             warning (OPT_Wtype_limits, "comparison is always true due to limited range of data type");
2687         }
2688
2689       if (val != 0)
2690         {
2691           /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2692           if (TREE_SIDE_EFFECTS (primop0))
2693             return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
2694           return val;
2695         }
2696
2697       /* Value is not predetermined, but do the comparison
2698          in the type of the operand that is not constant.
2699          TYPE is already properly set.  */
2700     }
2701
2702   /* If either arg is decimal float and the other is float, find the
2703      proper common type to use for comparison.  */
2704   else if (real1 && real2
2705            && (DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop0)))
2706                || DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop1)))))
2707     type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
2708
2709   else if (real1 && real2
2710            && (TYPE_PRECISION (TREE_TYPE (primop0))
2711                == TYPE_PRECISION (TREE_TYPE (primop1))))
2712     type = TREE_TYPE (primop0);
2713
2714   /* If args' natural types are both narrower than nominal type
2715      and both extend in the same manner, compare them
2716      in the type of the wider arg.
2717      Otherwise must actually extend both to the nominal
2718      common type lest different ways of extending
2719      alter the result.
2720      (eg, (short)-1 == (unsigned short)-1  should be 0.)  */
2721
2722   else if (unsignedp0 == unsignedp1 && real1 == real2
2723            && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
2724            && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
2725     {
2726       type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
2727       type = c_common_signed_or_unsigned_type (unsignedp0
2728                                                || TYPE_UNSIGNED (*restype_ptr),
2729                                                type);
2730       /* Make sure shorter operand is extended the right way
2731          to match the longer operand.  */
2732       primop0
2733         = convert (c_common_signed_or_unsigned_type (unsignedp0,
2734                                                      TREE_TYPE (primop0)),
2735                    primop0);
2736       primop1
2737         = convert (c_common_signed_or_unsigned_type (unsignedp1,
2738                                                      TREE_TYPE (primop1)),
2739                    primop1);
2740     }
2741   else
2742     {
2743       /* Here we must do the comparison on the nominal type
2744          using the args exactly as we received them.  */
2745       type = *restype_ptr;
2746       primop0 = op0;
2747       primop1 = op1;
2748
2749       if (!real1 && !real2 && integer_zerop (primop1)
2750           && TYPE_UNSIGNED (*restype_ptr))
2751         {
2752           tree value = 0;
2753           switch (code)
2754             {
2755             case GE_EXPR:
2756               /* All unsigned values are >= 0, so we warn.  However,
2757                  if OP0 is a constant that is >= 0, the signedness of
2758                  the comparison isn't an issue, so suppress the
2759                  warning.  */
2760               if (warn_type_limits && !in_system_header
2761                   && !(TREE_CODE (primop0) == INTEGER_CST
2762                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
2763                                                    primop0))))
2764                 warning (OPT_Wtype_limits,
2765                          "comparison of unsigned expression >= 0 is always true");
2766               value = truthvalue_true_node;
2767               break;
2768
2769             case LT_EXPR:
2770               if (warn_type_limits && !in_system_header
2771                   && !(TREE_CODE (primop0) == INTEGER_CST
2772                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
2773                                                    primop0))))
2774                 warning (OPT_Wtype_limits,
2775                          "comparison of unsigned expression < 0 is always false");
2776               value = truthvalue_false_node;
2777               break;
2778
2779             default:
2780               break;
2781             }
2782
2783           if (value != 0)
2784             {
2785               /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2786               if (TREE_SIDE_EFFECTS (primop0))
2787                 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2788                                primop0, value);
2789               return value;
2790             }
2791         }
2792     }
2793
2794   *op0_ptr = convert (type, primop0);
2795   *op1_ptr = convert (type, primop1);
2796
2797   *restype_ptr = truthvalue_type_node;
2798
2799   return 0;
2800 }
2801 \f
2802 /* Return a tree for the sum or difference (RESULTCODE says which)
2803    of pointer PTROP and integer INTOP.  */
2804
2805 tree
2806 pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
2807 {
2808   tree size_exp, ret;
2809
2810   /* The result is a pointer of the same type that is being added.  */
2811   tree result_type = TREE_TYPE (ptrop);
2812
2813   if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
2814     {
2815       if (pedantic || warn_pointer_arith)
2816         pedwarn ("pointer of type %<void *%> used in arithmetic");
2817       size_exp = integer_one_node;
2818     }
2819   else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE)
2820     {
2821       if (pedantic || warn_pointer_arith)
2822         pedwarn ("pointer to a function used in arithmetic");
2823       size_exp = integer_one_node;
2824     }
2825   else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE)
2826     {
2827       if (pedantic || warn_pointer_arith)
2828         pedwarn ("pointer to member function used in arithmetic");
2829       size_exp = integer_one_node;
2830     }
2831   else
2832     size_exp = size_in_bytes (TREE_TYPE (result_type));
2833
2834   /* We are manipulating pointer values, so we don't need to warn
2835      about relying on undefined signed overflow.  We disable the
2836      warning here because we use integer types so fold won't know that
2837      they are really pointers.  */
2838   fold_defer_overflow_warnings ();
2839
2840   /* If what we are about to multiply by the size of the elements
2841      contains a constant term, apply distributive law
2842      and multiply that constant term separately.
2843      This helps produce common subexpressions.  */
2844   if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
2845       && !TREE_CONSTANT (intop)
2846       && TREE_CONSTANT (TREE_OPERAND (intop, 1))
2847       && TREE_CONSTANT (size_exp)
2848       /* If the constant comes from pointer subtraction,
2849          skip this optimization--it would cause an error.  */
2850       && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
2851       /* If the constant is unsigned, and smaller than the pointer size,
2852          then we must skip this optimization.  This is because it could cause
2853          an overflow error if the constant is negative but INTOP is not.  */
2854       && (!TYPE_UNSIGNED (TREE_TYPE (intop))
2855           || (TYPE_PRECISION (TREE_TYPE (intop))
2856               == TYPE_PRECISION (TREE_TYPE (ptrop)))))
2857     {
2858       enum tree_code subcode = resultcode;
2859       tree int_type = TREE_TYPE (intop);
2860       if (TREE_CODE (intop) == MINUS_EXPR)
2861         subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
2862       /* Convert both subexpression types to the type of intop,
2863          because weird cases involving pointer arithmetic
2864          can result in a sum or difference with different type args.  */
2865       ptrop = build_binary_op (subcode, ptrop,
2866                                convert (int_type, TREE_OPERAND (intop, 1)), 1);
2867       intop = convert (int_type, TREE_OPERAND (intop, 0));
2868     }
2869
2870   /* Convert the integer argument to a type the same size as sizetype
2871      so the multiply won't overflow spuriously.  */
2872   if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype)
2873       || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype))
2874     intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype),
2875                                              TYPE_UNSIGNED (sizetype)), intop);
2876
2877   /* Replace the integer argument with a suitable product by the object size.
2878      Do this multiplication as signed, then convert to the appropriate
2879      type for the pointer operation.  */
2880   intop = convert (sizetype,
2881                    build_binary_op (MULT_EXPR, intop,
2882                                     convert (TREE_TYPE (intop), size_exp), 1));
2883
2884   /* Create the sum or difference.  */
2885   if (resultcode == MINUS_EXPR)
2886     intop = fold_build1 (NEGATE_EXPR, sizetype, intop);
2887
2888   ret = fold_build2 (POINTER_PLUS_EXPR, result_type, ptrop, intop);
2889
2890   fold_undefer_and_ignore_overflow_warnings ();
2891
2892   return ret;
2893 }
2894 \f
2895 /* Return whether EXPR is a declaration whose address can never be
2896    NULL.  */
2897
2898 bool
2899 decl_with_nonnull_addr_p (const_tree expr)
2900 {
2901   return (DECL_P (expr)
2902           && (TREE_CODE (expr) == PARM_DECL
2903               || TREE_CODE (expr) == LABEL_DECL
2904               || !DECL_WEAK (expr)));
2905 }
2906
2907 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
2908    or for an `if' or `while' statement or ?..: exp.  It should already
2909    have been validated to be of suitable type; otherwise, a bad
2910    diagnostic may result.
2911
2912    This preparation consists of taking the ordinary
2913    representation of an expression expr and producing a valid tree
2914    boolean expression describing whether expr is nonzero.  We could
2915    simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1),
2916    but we optimize comparisons, &&, ||, and !.
2917
2918    The resulting type should always be `truthvalue_type_node'.  */
2919
2920 tree
2921 c_common_truthvalue_conversion (tree expr)
2922 {
2923   switch (TREE_CODE (expr))
2924     {
2925     case EQ_EXPR:   case NE_EXPR:   case UNEQ_EXPR: case LTGT_EXPR:
2926     case LE_EXPR:   case GE_EXPR:   case LT_EXPR:   case GT_EXPR:
2927     case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR:
2928     case ORDERED_EXPR: case UNORDERED_EXPR:
2929       if (TREE_TYPE (expr) == truthvalue_type_node)
2930         return expr;
2931       return build2 (TREE_CODE (expr), truthvalue_type_node,
2932                      TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1));
2933
2934     case TRUTH_ANDIF_EXPR:
2935     case TRUTH_ORIF_EXPR:
2936     case TRUTH_AND_EXPR:
2937     case TRUTH_OR_EXPR:
2938     case TRUTH_XOR_EXPR:
2939       if (TREE_TYPE (expr) == truthvalue_type_node)
2940         return expr;
2941       return build2 (TREE_CODE (expr), truthvalue_type_node,
2942                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)),
2943                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)));
2944
2945     case TRUTH_NOT_EXPR:
2946       if (TREE_TYPE (expr) == truthvalue_type_node)
2947         return expr;
2948       return build1 (TREE_CODE (expr), truthvalue_type_node,
2949                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)));
2950
2951     case ERROR_MARK:
2952       return expr;
2953
2954     case INTEGER_CST:
2955       return integer_zerop (expr) ? truthvalue_false_node
2956                                   : truthvalue_true_node;
2957
2958     case REAL_CST:
2959       return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0)
2960              ? truthvalue_true_node
2961              : truthvalue_false_node;
2962
2963     case FIXED_CST:
2964       return fixed_compare (NE_EXPR, &TREE_FIXED_CST (expr),
2965                             &FCONST0 (TYPE_MODE (TREE_TYPE (expr))))
2966              ? truthvalue_true_node
2967              : truthvalue_false_node;
2968
2969     case FUNCTION_DECL:
2970       expr = build_unary_op (ADDR_EXPR, expr, 0);
2971       /* Fall through.  */
2972
2973     case ADDR_EXPR:
2974       {
2975         tree inner = TREE_OPERAND (expr, 0);
2976         if (decl_with_nonnull_addr_p (inner))
2977           {
2978             /* Common Ada/Pascal programmer's mistake.  */
2979             warning (OPT_Waddress,
2980                      "the address of %qD will always evaluate as %<true%>",
2981                      inner);
2982             return truthvalue_true_node;
2983           }
2984
2985         /* If we still have a decl, it is possible for its address to
2986            be NULL, so we cannot optimize.  */
2987         if (DECL_P (inner))
2988           {
2989             gcc_assert (DECL_WEAK (inner));
2990             break;
2991           }
2992
2993         if (TREE_SIDE_EFFECTS (inner))
2994           return build2 (COMPOUND_EXPR, truthvalue_type_node,
2995                          inner, truthvalue_true_node);
2996         else
2997           return truthvalue_true_node;
2998       }
2999
3000     case COMPLEX_EXPR:
3001       return build_binary_op ((TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
3002                                ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
3003                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)),
3004                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
3005                               0);
3006
3007     case NEGATE_EXPR:
3008     case ABS_EXPR:
3009     case FLOAT_EXPR:
3010       /* These don't change whether an object is nonzero or zero.  */
3011       return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
3012
3013     case LROTATE_EXPR:
3014     case RROTATE_EXPR:
3015       /* These don't change whether an object is zero or nonzero, but
3016          we can't ignore them if their second arg has side-effects.  */
3017       if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
3018         return build2 (COMPOUND_EXPR, truthvalue_type_node,
3019                        TREE_OPERAND (expr, 1),
3020                        c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)));
3021       else
3022         return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
3023
3024     case COND_EXPR:
3025       /* Distribute the conversion into the arms of a COND_EXPR.  */
3026       return fold_build3 (COND_EXPR, truthvalue_type_node,
3027                 TREE_OPERAND (expr, 0),
3028                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
3029                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 2)));
3030
3031     case CONVERT_EXPR:
3032     case NOP_EXPR:
3033       /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
3034          since that affects how `default_conversion' will behave.  */
3035       if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
3036           || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
3037         break;
3038       /* If this is widening the argument, we can ignore it.  */
3039       if (TYPE_PRECISION (TREE_TYPE (expr))
3040           >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
3041         return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
3042       break;
3043
3044     case MODIFY_EXPR:
3045       if (!TREE_NO_WARNING (expr)
3046           && warn_parentheses)
3047         {
3048           warning (OPT_Wparentheses,
3049                    "suggest parentheses around assignment used as truth value");
3050           TREE_NO_WARNING (expr) = 1;
3051         }
3052       break;
3053
3054     default:
3055       break;
3056     }
3057
3058   if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
3059     {
3060       tree t = save_expr (expr);
3061       return (build_binary_op
3062               ((TREE_SIDE_EFFECTS (expr)
3063                 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
3064         c_common_truthvalue_conversion (build_unary_op (REALPART_EXPR, t, 0)),
3065         c_common_truthvalue_conversion (build_unary_op (IMAGPART_EXPR, t, 0)),
3066                0));
3067     }
3068
3069   if (TREE_CODE (TREE_TYPE (expr)) == FIXED_POINT_TYPE)
3070     {
3071       tree fixed_zero_node = build_fixed (TREE_TYPE (expr),
3072                                           FCONST0 (TYPE_MODE
3073                                                    (TREE_TYPE (expr))));
3074       return build_binary_op (NE_EXPR, expr, fixed_zero_node, 1);
3075     }
3076
3077   return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3078 }
3079 \f
3080 static void def_builtin_1  (enum built_in_function fncode,
3081                             const char *name,
3082                             enum built_in_class fnclass,
3083                             tree fntype, tree libtype,
3084                             bool both_p, bool fallback_p, bool nonansi_p,
3085                             tree fnattrs, bool implicit_p);
3086
3087 /* Make a variant type in the proper way for C/C++, propagating qualifiers
3088    down to the element type of an array.  */
3089
3090 tree
3091 c_build_qualified_type (tree type, int type_quals)
3092 {
3093   if (type == error_mark_node)
3094     return type;
3095
3096   if (TREE_CODE (type) == ARRAY_TYPE)
3097     {
3098       tree t;
3099       tree element_type = c_build_qualified_type (TREE_TYPE (type),
3100                                                   type_quals);
3101
3102       /* See if we already have an identically qualified type.  */
3103       for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
3104         {
3105           if (TYPE_QUALS (strip_array_types (t)) == type_quals
3106               && TYPE_NAME (t) == TYPE_NAME (type)
3107               && TYPE_CONTEXT (t) == TYPE_CONTEXT (type)
3108               && attribute_list_equal (TYPE_ATTRIBUTES (t),
3109                                        TYPE_ATTRIBUTES (type)))
3110             break;
3111         }
3112       if (!t)
3113         {
3114           tree domain = TYPE_DOMAIN (type);
3115
3116           t = build_variant_type_copy (type);
3117           TREE_TYPE (t) = element_type;
3118
3119           if (TYPE_STRUCTURAL_EQUALITY_P (element_type)
3120               || (domain && TYPE_STRUCTURAL_EQUALITY_P (domain)))
3121             SET_TYPE_STRUCTURAL_EQUALITY (t);
3122           else if (TYPE_CANONICAL (element_type) != element_type
3123                    || (domain && TYPE_CANONICAL (domain) != domain))
3124             {
3125               tree unqualified_canon
3126                 = build_array_type (TYPE_CANONICAL (element_type),
3127                                     domain? TYPE_CANONICAL (domain)
3128                                           : NULL_TREE);
3129               TYPE_CANONICAL (t)
3130                 = c_build_qualified_type (unqualified_canon, type_quals);
3131             }
3132           else
3133             TYPE_CANONICAL (t) = t;
3134         }
3135       return t;
3136     }
3137
3138   /* A restrict-qualified pointer type must be a pointer to object or
3139      incomplete type.  Note that the use of POINTER_TYPE_P also allows
3140      REFERENCE_TYPEs, which is appropriate for C++.  */
3141   if ((type_quals & TYPE_QUAL_RESTRICT)
3142       && (!POINTER_TYPE_P (type)
3143           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type))))
3144     {
3145       error ("invalid use of %<restrict%>");
3146       type_quals &= ~TYPE_QUAL_RESTRICT;
3147     }
3148
3149   return build_qualified_type (type, type_quals);
3150 }
3151
3152 /* Apply the TYPE_QUALS to the new DECL.  */
3153
3154 void
3155 c_apply_type_quals_to_decl (int type_quals, tree decl)
3156 {
3157   tree type = TREE_TYPE (decl);
3158
3159   if (type == error_mark_node)
3160     return;
3161
3162   if (((type_quals & TYPE_QUAL_CONST)
3163        || (type && TREE_CODE (type) == REFERENCE_TYPE))
3164       /* An object declared 'const' is only readonly after it is
3165          initialized.  We don't have any way of expressing this currently,
3166          so we need to be conservative and unset TREE_READONLY for types
3167          with constructors.  Otherwise aliasing code will ignore stores in
3168          an inline constructor.  */
3169       && !(type && TYPE_NEEDS_CONSTRUCTING (type)))
3170     TREE_READONLY (decl) = 1;
3171   if (type_quals & TYPE_QUAL_VOLATILE)
3172     {
3173       TREE_SIDE_EFFECTS (decl) = 1;
3174       TREE_THIS_VOLATILE (decl) = 1;
3175     }
3176   if (type_quals & TYPE_QUAL_RESTRICT)
3177     {
3178       while (type && TREE_CODE (type) == ARRAY_TYPE)
3179         /* Allow 'restrict' on arrays of pointers.
3180            FIXME currently we just ignore it.  */
3181         type = TREE_TYPE (type);
3182       if (!type
3183           || !POINTER_TYPE_P (type)
3184           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))
3185         error ("invalid use of %<restrict%>");
3186       else if (flag_strict_aliasing && type == TREE_TYPE (decl))
3187         /* Indicate we need to make a unique alias set for this pointer.
3188            We can't do it here because it might be pointing to an
3189            incomplete type.  */
3190         DECL_POINTER_ALIAS_SET (decl) = -2;
3191     }
3192 }
3193
3194 /* Hash function for the problem of multiple type definitions in
3195    different files.  This must hash all types that will compare
3196    equal via comptypes to the same value.  In practice it hashes
3197    on some of the simple stuff and leaves the details to comptypes.  */
3198
3199 static hashval_t
3200 c_type_hash (const void *p)
3201 {
3202   int i = 0;
3203   int shift, size;
3204   const_tree const t = (const_tree) p;
3205   tree t2;
3206   switch (TREE_CODE (t))
3207     {
3208     /* For pointers, hash on pointee type plus some swizzling.  */
3209     case POINTER_TYPE:
3210       return c_type_hash (TREE_TYPE (t)) ^ 0x3003003;
3211     /* Hash on number of elements and total size.  */
3212     case ENUMERAL_TYPE:
3213       shift = 3;
3214       t2 = TYPE_VALUES (t);
3215       break;
3216     case RECORD_TYPE:
3217       shift = 0;
3218       t2 = TYPE_FIELDS (t);
3219       break;
3220     case QUAL_UNION_TYPE:
3221       shift = 1;
3222       t2 = TYPE_FIELDS (t);
3223       break;
3224     case UNION_TYPE:
3225       shift = 2;
3226       t2 = TYPE_FIELDS (t);
3227       break;
3228     default:
3229       gcc_unreachable ();
3230     }
3231   for (; t2; t2 = TREE_CHAIN (t2))
3232     i++;
3233   size = TREE_INT_CST_LOW (TYPE_SIZE (t));
3234   return ((size << 24) | (i << shift));
3235 }
3236
3237 static GTY((param_is (union tree_node))) htab_t type_hash_table;
3238
3239 /* Return the typed-based alias set for T, which may be an expression
3240    or a type.  Return -1 if we don't do anything special.  */
3241
3242 alias_set_type
3243 c_common_get_alias_set (tree t)
3244 {
3245   tree u;
3246   PTR *slot;
3247
3248   /* Permit type-punning when accessing a union, provided the access
3249      is directly through the union.  For example, this code does not
3250      permit taking the address of a union member and then storing
3251      through it.  Even the type-punning allowed here is a GCC
3252      extension, albeit a common and useful one; the C standard says
3253      that such accesses have implementation-defined behavior.  */
3254   for (u = t;
3255        TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
3256        u = TREE_OPERAND (u, 0))
3257     if (TREE_CODE (u) == COMPONENT_REF
3258         && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
3259       return 0;
3260
3261   /* That's all the expressions we handle specially.  */
3262   if (!TYPE_P (t))
3263     return -1;
3264
3265   /* The C standard guarantees that any object may be accessed via an
3266      lvalue that has character type.  */
3267   if (t == char_type_node
3268       || t == signed_char_type_node
3269       || t == unsigned_char_type_node)
3270     return 0;
3271
3272   /* If it has the may_alias attribute, it can alias anything.  */
3273   if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (t)))
3274     return 0;
3275
3276   /* The C standard specifically allows aliasing between signed and
3277      unsigned variants of the same type.  We treat the signed
3278      variant as canonical.  */
3279   if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t))
3280     {
3281       tree t1 = c_common_signed_type (t);
3282
3283       /* t1 == t can happen for boolean nodes which are always unsigned.  */
3284       if (t1 != t)
3285         return get_alias_set (t1);
3286     }
3287   else if (POINTER_TYPE_P (t))
3288     {
3289       tree t1;
3290
3291       /* Unfortunately, there is no canonical form of a pointer type.
3292          In particular, if we have `typedef int I', then `int *', and
3293          `I *' are different types.  So, we have to pick a canonical
3294          representative.  We do this below.
3295
3296          Technically, this approach is actually more conservative that
3297          it needs to be.  In particular, `const int *' and `int *'
3298          should be in different alias sets, according to the C and C++
3299          standard, since their types are not the same, and so,
3300          technically, an `int **' and `const int **' cannot point at
3301          the same thing.
3302
3303          But, the standard is wrong.  In particular, this code is
3304          legal C++:
3305
3306             int *ip;
3307             int **ipp = &ip;
3308             const int* const* cipp = ipp;
3309
3310          And, it doesn't make sense for that to be legal unless you
3311          can dereference IPP and CIPP.  So, we ignore cv-qualifiers on
3312          the pointed-to types.  This issue has been reported to the
3313          C++ committee.  */
3314       t1 = build_type_no_quals (t);
3315       if (t1 != t)
3316         return get_alias_set (t1);
3317     }
3318
3319   /* Handle the case of multiple type nodes referring to "the same" type,
3320      which occurs with IMA.  These share an alias set.  FIXME:  Currently only
3321      C90 is handled.  (In C99 type compatibility is not transitive, which
3322      complicates things mightily. The alias set splay trees can theoretically
3323      represent this, but insertion is tricky when you consider all the
3324      different orders things might arrive in.) */
3325
3326   if (c_language != clk_c || flag_isoc99)
3327     return -1;
3328
3329   /* Save time if there's only one input file.  */
3330   if (num_in_fnames == 1)
3331     return -1;
3332
3333   /* Pointers need special handling if they point to any type that
3334      needs special handling (below).  */
3335   if (TREE_CODE (t) == POINTER_TYPE)
3336     {
3337       tree t2;
3338       /* Find bottom type under any nested POINTERs.  */
3339       for (t2 = TREE_TYPE (t);
3340            TREE_CODE (t2) == POINTER_TYPE;
3341            t2 = TREE_TYPE (t2))
3342         ;
3343       if (TREE_CODE (t2) != RECORD_TYPE
3344           && TREE_CODE (t2) != ENUMERAL_TYPE
3345           && TREE_CODE (t2) != QUAL_UNION_TYPE
3346           && TREE_CODE (t2) != UNION_TYPE)
3347         return -1;
3348       if (TYPE_SIZE (t2) == 0)
3349         return -1;
3350     }
3351   /* These are the only cases that need special handling.  */
3352   if (TREE_CODE (t) != RECORD_TYPE
3353       && TREE_CODE (t) != ENUMERAL_TYPE
3354       && TREE_CODE (t) != QUAL_UNION_TYPE
3355       && TREE_CODE (t) != UNION_TYPE
3356       && TREE_CODE (t) != POINTER_TYPE)
3357     return -1;
3358   /* Undefined? */
3359   if (TYPE_SIZE (t) == 0)
3360     return -1;
3361
3362   /* Look up t in hash table.  Only one of the compatible types within each
3363      alias set is recorded in the table.  */
3364   if (!type_hash_table)
3365     type_hash_table = htab_create_ggc (1021, c_type_hash,
3366             (htab_eq) lang_hooks.types_compatible_p,
3367             NULL);
3368   slot = htab_find_slot (type_hash_table, t, INSERT);
3369   if (*slot != NULL)
3370     {
3371       TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot);
3372       return TYPE_ALIAS_SET ((tree)*slot);
3373     }
3374   else
3375     /* Our caller will assign and record (in t) a new alias set; all we need
3376        to do is remember t in the hash table.  */
3377     *slot = t;
3378
3379   return -1;
3380 }
3381 \f
3382 /* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where the
3383    second parameter indicates which OPERATOR is being applied.  The COMPLAIN
3384    flag controls whether we should diagnose possibly ill-formed
3385    constructs or not.  */
3386
3387 tree
3388 c_sizeof_or_alignof_type (tree type, bool is_sizeof, int complain)
3389 {
3390   const char *op_name;
3391   tree value = NULL;
3392   enum tree_code type_code = TREE_CODE (type);
3393
3394   op_name = is_sizeof ? "sizeof" : "__alignof__";
3395
3396   if (type_code == FUNCTION_TYPE)
3397     {
3398       if (is_sizeof)
3399         {
3400           if (complain && (pedantic || warn_pointer_arith))
3401             pedwarn ("invalid application of %<sizeof%> to a function type");
3402           value = size_one_node;
3403         }
3404       else
3405         value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);
3406     }
3407   else if (type_code == VOID_TYPE || type_code == ERROR_MARK)
3408     {
3409       if (type_code == VOID_TYPE
3410           && complain && (pedantic || warn_pointer_arith))
3411         pedwarn ("invalid application of %qs to a void type", op_name);
3412       value = size_one_node;
3413     }
3414   else if (!COMPLETE_TYPE_P (type))
3415     {
3416       if (complain)
3417         error ("invalid application of %qs to incomplete type %qT ",
3418                op_name, type);
3419       value = size_zero_node;
3420     }
3421   else
3422     {
3423       if (is_sizeof)
3424         /* Convert in case a char is more than one unit.  */
3425         value = size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
3426                             size_int (TYPE_PRECISION (char_type_node)
3427                                       / BITS_PER_UNIT));
3428       else
3429         value = size_int (TYPE_ALIGN_UNIT (type));
3430     }
3431
3432   /* VALUE will have an integer type with TYPE_IS_SIZETYPE set.
3433      TYPE_IS_SIZETYPE means that certain things (like overflow) will
3434      never happen.  However, this node should really have type
3435      `size_t', which is just a typedef for an ordinary integer type.  */
3436   value = fold_convert (size_type_node, value);
3437   gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value)));
3438
3439   return value;
3440 }
3441
3442 /* Implement the __alignof keyword: Return the minimum required
3443    alignment of EXPR, measured in bytes.  For VAR_DECLs,
3444    FUNCTION_DECLs and FIELD_DECLs return DECL_ALIGN (which can be set
3445    from an "aligned" __attribute__ specification).  */
3446
3447 tree
3448 c_alignof_expr (tree expr)
3449 {
3450   tree t;
3451
3452   if (VAR_OR_FUNCTION_DECL_P (expr))
3453     t = size_int (DECL_ALIGN_UNIT (expr));
3454
3455   else if (TREE_CODE (expr) == COMPONENT_REF
3456            && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1)))
3457     {
3458       error ("%<__alignof%> applied to a bit-field");
3459       t = size_one_node;
3460     }
3461   else if (TREE_CODE (expr) == COMPONENT_REF
3462            && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL)
3463     t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1)));
3464
3465   else if (TREE_CODE (expr) == INDIRECT_REF)
3466     {
3467       tree t = TREE_OPERAND (expr, 0);
3468       tree best = t;
3469       int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
3470
3471       while ((TREE_CODE (t) == NOP_EXPR || TREE_CODE (t) == CONVERT_EXPR)
3472              && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE)
3473         {
3474           int thisalign;
3475
3476           t = TREE_OPERAND (t, 0);
3477           thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
3478           if (thisalign > bestalign)
3479             best = t, bestalign = thisalign;
3480         }
3481       return c_alignof (TREE_TYPE (TREE_TYPE (best)));
3482     }
3483   else
3484     return c_alignof (TREE_TYPE (expr));
3485
3486   return fold_convert (size_type_node, t);
3487 }
3488 \f
3489 /* Handle C and C++ default attributes.  */
3490
3491 enum built_in_attribute
3492 {
3493 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
3494 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
3495 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
3496 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
3497 #include "builtin-attrs.def"
3498 #undef DEF_ATTR_NULL_TREE
3499 #undef DEF_ATTR_INT
3500 #undef DEF_ATTR_IDENT
3501 #undef DEF_ATTR_TREE_LIST
3502   ATTR_LAST
3503 };
3504
3505 static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
3506
3507 static void c_init_attributes (void);
3508
3509 enum c_builtin_type
3510 {
3511 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
3512 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
3513 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
3514 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
3515 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
3516 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
3517 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
3518 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) NAME,
3519 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7) NAME,
3520 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
3521 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
3522 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
3523 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
3524 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
3525 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \
3526   NAME,
3527 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
3528 #include "builtin-types.def"
3529 #undef DEF_PRIMITIVE_TYPE
3530 #undef DEF_FUNCTION_TYPE_0
3531 #undef DEF_FUNCTION_TYPE_1
3532 #undef DEF_FUNCTION_TYPE_2
3533 #undef DEF_FUNCTION_TYPE_3
3534 #undef DEF_FUNCTION_TYPE_4
3535 #undef DEF_FUNCTION_TYPE_5
3536 #undef DEF_FUNCTION_TYPE_6
3537 #undef DEF_FUNCTION_TYPE_7
3538 #undef DEF_FUNCTION_TYPE_VAR_0
3539 #undef DEF_FUNCTION_TYPE_VAR_1
3540 #undef DEF_FUNCTION_TYPE_VAR_2
3541 #undef DEF_FUNCTION_TYPE_VAR_3
3542 #undef DEF_FUNCTION_TYPE_VAR_4
3543 #undef DEF_FUNCTION_TYPE_VAR_5
3544 #undef DEF_POINTER_TYPE
3545   BT_LAST
3546 };
3547
3548 typedef enum c_builtin_type builtin_type;
3549
3550 /* A temporary array for c_common_nodes_and_builtins.  Used in
3551    communication with def_fn_type.  */
3552 static tree builtin_types[(int) BT_LAST + 1];
3553
3554 /* A helper function for c_common_nodes_and_builtins.  Build function type
3555    for DEF with return type RET and N arguments.  If VAR is true, then the
3556    function should be variadic after those N arguments.
3557
3558    Takes special care not to ICE if any of the types involved are
3559    error_mark_node, which indicates that said type is not in fact available
3560    (see builtin_type_for_size).  In which case the function type as a whole
3561    should be error_mark_node.  */
3562
3563 static void
3564 def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...)
3565 {
3566   tree args = NULL, t;
3567   va_list list;
3568   int i;
3569
3570   va_start (list, n);
3571   for (i = 0; i < n; ++i)
3572     {
3573       builtin_type a = va_arg (list, builtin_type);
3574       t = builtin_types[a];
3575       if (t == error_mark_node)
3576         goto egress;
3577       args = tree_cons (NULL_TREE, t, args);
3578     }
3579   va_end (list);
3580
3581   args = nreverse (args);
3582   if (!var)
3583     args = chainon (args, void_list_node);
3584
3585   t = builtin_types[ret];
3586   if (t == error_mark_node)
3587     goto egress;
3588   t = build_function_type (t, args);
3589
3590  egress:
3591   builtin_types[def] = t;
3592 }
3593
3594 /* Build builtin functions common to both C and C++ language
3595    frontends.  */
3596
3597 static void
3598 c_define_builtins (tree va_list_ref_type_node, tree va_list_arg_type_node)
3599 {
3600 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
3601   builtin_types[ENUM] = VALUE;
3602 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
3603   def_fn_type (ENUM, RETURN, 0, 0);
3604 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
3605   def_fn_type (ENUM, RETURN, 0, 1, ARG1);
3606 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
3607   def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
3608 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
3609   def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
3610 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
3611   def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
3612 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
3613   def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
3614 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
3615                             ARG6)                                       \
3616   def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
3617 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
3618                             ARG6, ARG7)                                 \
3619   def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
3620 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
3621   def_fn_type (ENUM, RETURN, 1, 0);
3622 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
3623   def_fn_type (ENUM, RETURN, 1, 1, ARG1);
3624 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
3625   def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
3626 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
3627   def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
3628 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
3629   def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
3630 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
3631   def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
3632 #define DEF_POINTER_TYPE(ENUM, TYPE) \
3633   builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
3634
3635 #include "builtin-types.def"
3636
3637 #undef DEF_PRIMITIVE_TYPE
3638 #undef DEF_FUNCTION_TYPE_1
3639 #undef DEF_FUNCTION_TYPE_2
3640 #undef DEF_FUNCTION_TYPE_3
3641 #undef DEF_FUNCTION_TYPE_4
3642 #undef DEF_FUNCTION_TYPE_5
3643 #undef DEF_FUNCTION_TYPE_6
3644 #undef DEF_FUNCTION_TYPE_VAR_0
3645 #undef DEF_FUNCTION_TYPE_VAR_1
3646 #undef DEF_FUNCTION_TYPE_VAR_2
3647 #undef DEF_FUNCTION_TYPE_VAR_3
3648 #undef DEF_FUNCTION_TYPE_VAR_4
3649 #undef DEF_FUNCTION_TYPE_VAR_5
3650 #undef DEF_POINTER_TYPE
3651   builtin_types[(int) BT_LAST] = NULL_TREE;
3652
3653   c_init_attributes ();
3654
3655 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
3656                     NONANSI_P, ATTRS, IMPLICIT, COND)                   \
3657   if (NAME && COND)                                                     \
3658     def_builtin_1 (ENUM, NAME, CLASS,                                   \
3659                    builtin_types[(int) TYPE],                           \
3660                    builtin_types[(int) LIBTYPE],                        \
3661                    BOTH_P, FALLBACK_P, NONANSI_P,                       \
3662                    built_in_attributes[(int) ATTRS], IMPLICIT);
3663 #include "builtins.def"
3664 #undef DEF_BUILTIN
3665
3666   targetm.init_builtins ();
3667
3668   build_common_builtin_nodes ();
3669
3670   if (flag_mudflap)
3671     mudflap_init ();
3672 }
3673
3674 /* Build tree nodes and builtin functions common to both C and C++ language
3675    frontends.  */
3676
3677 void
3678 c_common_nodes_and_builtins (void)
3679 {
3680   int wchar_type_size;
3681   tree array_domain_type;
3682   tree va_list_ref_type_node;
3683   tree va_list_arg_type_node;
3684
3685   /* Define `int' and `char' first so that dbx will output them first.  */
3686   record_builtin_type (RID_INT, NULL, integer_type_node);
3687   record_builtin_type (RID_CHAR, "char", char_type_node);
3688
3689   /* `signed' is the same as `int'.  FIXME: the declarations of "signed",
3690      "unsigned long", "long long unsigned" and "unsigned short" were in C++
3691      but not C.  Are the conditionals here needed?  */
3692   if (c_dialect_cxx ())
3693     record_builtin_type (RID_SIGNED, NULL, integer_type_node);
3694   record_builtin_type (RID_LONG, "long int", long_integer_type_node);
3695   record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
3696   record_builtin_type (RID_MAX, "long unsigned int",
3697                        long_unsigned_type_node);
3698   if (c_dialect_cxx ())
3699     record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
3700   record_builtin_type (RID_MAX, "long long int",
3701                        long_long_integer_type_node);
3702   record_builtin_type (RID_MAX, "long long unsigned int",
3703                        long_long_unsigned_type_node);
3704   if (c_dialect_cxx ())
3705     record_builtin_type (RID_MAX, "long long unsigned",
3706                          long_long_unsigned_type_node);
3707   record_builtin_type (RID_SHORT, "short int", short_integer_type_node);
3708   record_builtin_type (RID_MAX, "short unsigned int",
3709                        short_unsigned_type_node);
3710   if (c_dialect_cxx ())
3711     record_builtin_type (RID_MAX, "unsigned short",
3712                          short_unsigned_type_node);
3713
3714   /* Define both `signed char' and `unsigned char'.  */
3715   record_builtin_type (RID_MAX, "signed char", signed_char_type_node);
3716   record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node);
3717
3718   /* These are types that c_common_type_for_size and
3719      c_common_type_for_mode use.  */
3720   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3721                                          intQI_type_node));
3722   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3723                                          intHI_type_node));
3724   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3725                                          intSI_type_node));
3726   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3727                                          intDI_type_node));
3728 #if HOST_BITS_PER_WIDE_INT >= 64
3729   if (targetm.scalar_mode_supported_p (TImode))
3730     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3731                                            get_identifier ("__int128_t"),
3732                                            intTI_type_node));
3733 #endif
3734   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3735                                          unsigned_intQI_type_node));
3736   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3737                                          unsigned_intHI_type_node));
3738   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3739                                          unsigned_intSI_type_node));
3740   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3741                                          unsigned_intDI_type_node));
3742 #if HOST_BITS_PER_WIDE_INT >= 64
3743   if (targetm.scalar_mode_supported_p (TImode))
3744     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3745                                            get_identifier ("__uint128_t"),
3746                                            unsigned_intTI_type_node));
3747 #endif
3748
3749   /* Create the widest literal types.  */
3750   widest_integer_literal_type_node
3751     = make_signed_type (HOST_BITS_PER_WIDE_INT * 2);
3752   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3753                                          widest_integer_literal_type_node));
3754
3755   widest_unsigned_literal_type_node
3756     = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2);
3757   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3758                                          widest_unsigned_literal_type_node));
3759
3760   /* `unsigned long' is the standard type for sizeof.
3761      Note that stddef.h uses `unsigned long',
3762      and this must agree, even if long and int are the same size.  */
3763   size_type_node =
3764     TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE)));
3765   signed_size_type_node = c_common_signed_type (size_type_node);
3766   set_sizetype (size_type_node);
3767
3768   pid_type_node =
3769     TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE)));
3770
3771   build_common_tree_nodes_2 (flag_short_double);
3772
3773   record_builtin_type (RID_FLOAT, NULL, float_type_node);
3774   record_builtin_type (RID_DOUBLE, NULL, double_type_node);
3775   record_builtin_type (RID_MAX, "long double", long_double_type_node);
3776
3777   /* Only supported decimal floating point extension if the target
3778      actually supports underlying modes. */
3779   if (targetm.scalar_mode_supported_p (SDmode)
3780       && targetm.scalar_mode_supported_p (DDmode)
3781       && targetm.scalar_mode_supported_p (TDmode))
3782     {
3783       record_builtin_type (RID_DFLOAT32, NULL, dfloat32_type_node);
3784       record_builtin_type (RID_DFLOAT64, NULL, dfloat64_type_node);
3785       record_builtin_type (RID_DFLOAT128, NULL, dfloat128_type_node);
3786     }
3787
3788   if (targetm.fixed_point_supported_p ())
3789     {
3790       record_builtin_type (RID_MAX, "short _Fract", short_fract_type_node);
3791       record_builtin_type (RID_FRACT, NULL, fract_type_node);
3792       record_builtin_type (RID_MAX, "long _Fract", long_fract_type_node);
3793       record_builtin_type (RID_MAX, "long long _Fract",
3794                            long_long_fract_type_node);
3795       record_builtin_type (RID_MAX, "unsigned short _Fract",
3796                            unsigned_short_fract_type_node);
3797       record_builtin_type (RID_MAX, "unsigned _Fract",
3798                            unsigned_fract_type_node);
3799       record_builtin_type (RID_MAX, "unsigned long _Fract",
3800                            unsigned_long_fract_type_node);
3801       record_builtin_type (RID_MAX, "unsigned long long _Fract",
3802                            unsigned_long_long_fract_type_node);
3803       record_builtin_type (RID_MAX, "_Sat short _Fract",
3804                            sat_short_fract_type_node);
3805       record_builtin_type (RID_MAX, "_Sat _Fract", sat_fract_type_node);
3806       record_builtin_type (RID_MAX, "_Sat long _Fract",
3807                            sat_long_fract_type_node);
3808       record_builtin_type (RID_MAX, "_Sat long long _Fract",
3809                            sat_long_long_fract_type_node);
3810       record_builtin_type (RID_MAX, "_Sat unsigned short _Fract",
3811                            sat_unsigned_short_fract_type_node);
3812       record_builtin_type (RID_MAX, "_Sat unsigned _Fract",
3813                            sat_unsigned_fract_type_node);
3814       record_builtin_type (RID_MAX, "_Sat unsigned long _Fract",
3815                            sat_unsigned_long_fract_type_node);
3816       record_builtin_type (RID_MAX, "_Sat unsigned long long _Fract",
3817                            sat_unsigned_long_long_fract_type_node);
3818       record_builtin_type (RID_MAX, "short _Accum", short_accum_type_node);
3819       record_builtin_type (RID_ACCUM, NULL, accum_type_node);
3820       record_builtin_type (RID_MAX, "long _Accum", long_accum_type_node);
3821       record_builtin_type (RID_MAX, "long long _Accum",
3822                            long_long_accum_type_node);
3823       record_builtin_type (RID_MAX, "unsigned short _Accum",
3824                            unsigned_short_accum_type_node);
3825       record_builtin_type (RID_MAX, "unsigned _Accum",
3826                            unsigned_accum_type_node);
3827       record_builtin_type (RID_MAX, "unsigned long _Accum",
3828                            unsigned_long_accum_type_node);
3829       record_builtin_type (RID_MAX, "unsigned long long _Accum",
3830                            unsigned_long_long_accum_type_node);
3831       record_builtin_type (RID_MAX, "_Sat short _Accum",
3832                            sat_short_accum_type_node);
3833       record_builtin_type (RID_MAX, "_Sat _Accum", sat_accum_type_node);
3834       record_builtin_type (RID_MAX, "_Sat long _Accum",
3835                            sat_long_accum_type_node);
3836       record_builtin_type (RID_MAX, "_Sat long long _Accum",
3837                           sat_long_long_accum_type_node);
3838       record_builtin_type (RID_MAX, "_Sat unsigned short _Accum",
3839                            sat_unsigned_short_accum_type_node);
3840       record_builtin_type (RID_MAX, "_Sat unsigned _Accum",
3841                            sat_unsigned_accum_type_node);
3842       record_builtin_type (RID_MAX, "_Sat unsigned long _Accum",
3843                            sat_unsigned_long_accum_type_node);
3844       record_builtin_type (RID_MAX, "_Sat unsigned long long _Accum",
3845                            sat_unsigned_long_long_accum_type_node);
3846
3847     }
3848
3849   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3850                                          get_identifier ("complex int"),
3851                                          complex_integer_type_node));
3852   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3853                                          get_identifier ("complex float"),
3854                                          complex_float_type_node));
3855   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3856                                          get_identifier ("complex double"),
3857                                          complex_double_type_node));
3858   lang_hooks.decls.pushdecl
3859     (build_decl (TYPE_DECL, get_identifier ("complex long double"),
3860                  complex_long_double_type_node));
3861
3862   if (c_dialect_cxx ())
3863     /* For C++, make fileptr_type_node a distinct void * type until
3864        FILE type is defined.  */
3865     fileptr_type_node = build_variant_type_copy (ptr_type_node);
3866
3867   record_builtin_type (RID_VOID, NULL, void_type_node);
3868
3869   /* Set the TYPE_NAME for any variants that were built before
3870      record_builtin_type gave names to the built-in types. */
3871   {
3872     tree void_name = TYPE_NAME (void_type_node);
3873     TYPE_NAME (void_type_node) = NULL_TREE;
3874     TYPE_NAME (build_qualified_type (void_type_node, TYPE_QUAL_CONST))
3875       = void_name;
3876     TYPE_NAME (void_type_node) = void_name;
3877   }
3878
3879   /* This node must not be shared.  */
3880   void_zero_node = make_node (INTEGER_CST);
3881   TREE_TYPE (void_zero_node) = void_type_node;
3882
3883   void_list_node = build_void_list_node ();
3884
3885   /* Make a type to be the domain of a few array types
3886      whose domains don't really matter.
3887      200 is small enough that it always fits in size_t
3888      and large enough that it can hold most function names for the
3889      initializations of __FUNCTION__ and __PRETTY_FUNCTION__.  */
3890   array_domain_type = build_index_type (size_int (200));
3891
3892   /* Make a type for arrays of characters.
3893      With luck nothing will ever really depend on the length of this
3894      array type.  */
3895   char_array_type_node
3896     = build_array_type (char_type_node, array_domain_type);
3897
3898   /* Likewise for arrays of ints.  */
3899   int_array_type_node
3900     = build_array_type (integer_type_node, array_domain_type);
3901
3902   string_type_node = build_pointer_type (char_type_node);
3903   const_string_type_node
3904     = build_pointer_type (build_qualified_type
3905                           (char_type_node, TYPE_QUAL_CONST));
3906
3907   /* This is special for C++ so functions can be overloaded.  */
3908   wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE);
3909   wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node));
3910   wchar_type_size = TYPE_PRECISION (wchar_type_node);
3911   if (c_dialect_cxx ())
3912     {
3913       if (TYPE_UNSIGNED (wchar_type_node))
3914         wchar_type_node = make_unsigned_type (wchar_type_size);
3915       else
3916         wchar_type_node = make_signed_type (wchar_type_size);
3917       record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node);
3918     }
3919   else
3920     {
3921       signed_wchar_type_node = c_common_signed_type (wchar_type_node);
3922       unsigned_wchar_type_node = c_common_unsigned_type (wchar_type_node);
3923     }
3924
3925   /* This is for wide string constants.  */
3926   wchar_array_type_node
3927     = build_array_type (wchar_type_node, array_domain_type);
3928
3929   wint_type_node =
3930     TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE)));
3931
3932   intmax_type_node =
3933     TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE)));
3934   uintmax_type_node =
3935     TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE)));
3936
3937   default_function_type = build_function_type (integer_type_node, NULL_TREE);
3938   ptrdiff_type_node
3939     = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE)));
3940   unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node);
3941
3942   lang_hooks.decls.pushdecl
3943     (build_decl (TYPE_DECL, get_identifier ("__builtin_va_list"),
3944                  va_list_type_node));
3945
3946   if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
3947     {
3948       va_list_arg_type_node = va_list_ref_type_node =
3949         build_pointer_type (TREE_TYPE (va_list_type_node));
3950     }
3951   else
3952     {
3953       va_list_arg_type_node = va_list_type_node;
3954       va_list_ref_type_node = build_reference_type (va_list_type_node);
3955     }
3956
3957   if (!flag_preprocess_only)
3958     c_define_builtins (va_list_ref_type_node, va_list_arg_type_node);
3959
3960   main_identifier_node = get_identifier ("main");
3961
3962   /* Create the built-in __null node.  It is important that this is
3963      not shared.  */
3964   null_node = make_node (INTEGER_CST);
3965   TREE_TYPE (null_node) = c_common_type_for_size (POINTER_SIZE, 0);
3966
3967   /* Since builtin_types isn't gc'ed, don't export these nodes.  */
3968   memset (builtin_types, 0, sizeof (builtin_types));
3969 }
3970
3971 /* Look up the function in built_in_decls that corresponds to DECL
3972    and set ASMSPEC as its user assembler name.  DECL must be a
3973    function decl that declares a builtin.  */
3974
3975 void
3976 set_builtin_user_assembler_name (tree decl, const char *asmspec)
3977 {
3978   tree builtin;
3979   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
3980               && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
3981               && asmspec != 0);
3982
3983   builtin = built_in_decls [DECL_FUNCTION_CODE (decl)];
3984   set_user_assembler_name (builtin, asmspec);
3985   if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMCPY)
3986     init_block_move_fn (asmspec);
3987   else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMSET)
3988     init_block_clear_fn (asmspec);
3989 }
3990
3991 /* The number of named compound-literals generated thus far.  */
3992 static GTY(()) int compound_literal_number;
3993
3994 /* Set DECL_NAME for DECL, a VAR_DECL for a compound-literal.  */
3995
3996 void
3997 set_compound_literal_name (tree decl)
3998 {
3999   char *name;
4000   ASM_FORMAT_PRIVATE_NAME (name, "__compound_literal",
4001                            compound_literal_number);
4002   compound_literal_number++;
4003   DECL_NAME (decl) = get_identifier (name);
4004 }
4005
4006 tree
4007 build_va_arg (tree expr, tree type)
4008 {
4009   return build1 (VA_ARG_EXPR, type, expr);
4010 }
4011
4012
4013 /* Linked list of disabled built-in functions.  */
4014
4015 typedef struct disabled_builtin
4016 {
4017   const char *name;
4018   struct disabled_builtin *next;
4019 } disabled_builtin;
4020 static disabled_builtin *disabled_builtins = NULL;
4021
4022 static bool builtin_function_disabled_p (const char *);
4023
4024 /* Disable a built-in function specified by -fno-builtin-NAME.  If NAME
4025    begins with "__builtin_", give an error.  */
4026
4027 void
4028 disable_builtin_function (const char *name)
4029 {
4030   if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
4031     error ("cannot disable built-in function %qs", name);
4032   else
4033     {
4034       disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin);
4035       new_disabled_builtin->name = name;
4036       new_disabled_builtin->next = disabled_builtins;
4037       disabled_builtins = new_disabled_builtin;
4038     }
4039 }
4040
4041
4042 /* Return true if the built-in function NAME has been disabled, false
4043    otherwise.  */
4044
4045 static bool
4046 builtin_function_disabled_p (const char *name)
4047 {
4048   disabled_builtin *p;
4049   for (p = disabled_builtins; p != NULL; p = p->next)
4050     {
4051       if (strcmp (name, p->name) == 0)
4052         return true;
4053     }
4054   return false;
4055 }
4056
4057
4058 /* Worker for DEF_BUILTIN.
4059    Possibly define a builtin function with one or two names.
4060    Does not declare a non-__builtin_ function if flag_no_builtin, or if
4061    nonansi_p and flag_no_nonansi_builtin.  */
4062
4063 static void
4064 def_builtin_1 (enum built_in_function fncode,
4065                const char *name,
4066                enum built_in_class fnclass,
4067                tree fntype, tree libtype,
4068                bool both_p, bool fallback_p, bool nonansi_p,
4069                tree fnattrs, bool implicit_p)
4070 {
4071   tree decl;
4072   const char *libname;
4073
4074   if (fntype == error_mark_node)
4075     return;
4076
4077   gcc_assert ((!both_p && !fallback_p)
4078               || !strncmp (name, "__builtin_",
4079                            strlen ("__builtin_")));
4080
4081   libname = name + strlen ("__builtin_");
4082   decl = add_builtin_function (name, fntype, fncode, fnclass,
4083                                (fallback_p ? libname : NULL),
4084                                fnattrs);
4085   if (both_p
4086       && !flag_no_builtin && !builtin_function_disabled_p (libname)
4087       && !(nonansi_p && flag_no_nonansi_builtin))
4088     add_builtin_function (libname, libtype, fncode, fnclass,
4089                           NULL, fnattrs);
4090
4091   built_in_decls[(int) fncode] = decl;
4092   if (implicit_p)
4093     implicit_built_in_decls[(int) fncode] = decl;
4094 }
4095 \f
4096 /* Nonzero if the type T promotes to int.  This is (nearly) the
4097    integral promotions defined in ISO C99 6.3.1.1/2.  */
4098
4099 bool
4100 c_promoting_integer_type_p (const_tree t)
4101 {
4102   switch (TREE_CODE (t))
4103     {
4104     case INTEGER_TYPE:
4105       return (TYPE_MAIN_VARIANT (t) == char_type_node
4106               || TYPE_MAIN_VARIANT (t) == signed_char_type_node
4107               || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node
4108               || TYPE_MAIN_VARIANT (t) == short_integer_type_node
4109               || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node
4110               || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node));
4111
4112     case ENUMERAL_TYPE:
4113       /* ??? Technically all enumerations not larger than an int
4114          promote to an int.  But this is used along code paths
4115          that only want to notice a size change.  */
4116       return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node);
4117
4118     case BOOLEAN_TYPE:
4119       return 1;
4120
4121     default:
4122       return 0;
4123     }
4124 }
4125
4126 /* Return 1 if PARMS specifies a fixed number of parameters
4127    and none of their types is affected by default promotions.  */
4128
4129 int
4130 self_promoting_args_p (const_tree parms)
4131 {
4132   const_tree t;
4133   for (t = parms; t; t = TREE_CHAIN (t))
4134     {
4135       tree type = TREE_VALUE (t);
4136
4137       if (type == error_mark_node)
4138         continue;
4139
4140       if (TREE_CHAIN (t) == 0 && type != void_type_node)
4141         return 0;
4142
4143       if (type == 0)
4144         return 0;
4145
4146       if (TYPE_MAIN_VARIANT (type) == float_type_node)
4147         return 0;
4148
4149       if (c_promoting_integer_type_p (type))
4150         return 0;
4151     }
4152   return 1;
4153 }
4154
4155 /* Recursively examines the array elements of TYPE, until a non-array
4156    element type is found.  */
4157
4158 tree
4159 strip_array_types (tree type)
4160 {
4161   while (TREE_CODE (type) == ARRAY_TYPE)
4162     type = TREE_TYPE (type);
4163
4164   return type;
4165 }
4166
4167 /* Recursively remove any '*' or '&' operator from TYPE.  */
4168 tree
4169 strip_pointer_operator (tree t)
4170 {
4171   while (POINTER_TYPE_P (t))
4172     t = TREE_TYPE (t);
4173   return t;
4174 }
4175
4176 /* Recursively remove pointer or array type from TYPE. */
4177 tree
4178 strip_pointer_or_array_types (tree t)
4179 {
4180   while (TREE_CODE (t) == ARRAY_TYPE || POINTER_TYPE_P (t))
4181     t = TREE_TYPE (t);
4182   return t;
4183 }
4184
4185 /* Used to compare case labels.  K1 and K2 are actually tree nodes
4186    representing case labels, or NULL_TREE for a `default' label.
4187    Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
4188    K2, and 0 if K1 and K2 are equal.  */
4189
4190 int
4191 case_compare (splay_tree_key k1, splay_tree_key k2)
4192 {
4193   /* Consider a NULL key (such as arises with a `default' label) to be
4194      smaller than anything else.  */
4195   if (!k1)
4196     return k2 ? -1 : 0;
4197   else if (!k2)
4198     return k1 ? 1 : 0;
4199
4200   return tree_int_cst_compare ((tree) k1, (tree) k2);
4201 }
4202
4203 /* Process a case label for the range LOW_VALUE ... HIGH_VALUE.  If
4204    LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is
4205    actually a `default' label.  If only HIGH_VALUE is NULL_TREE, then
4206    case label was declared using the usual C/C++ syntax, rather than
4207    the GNU case range extension.  CASES is a tree containing all the
4208    case ranges processed so far; COND is the condition for the
4209    switch-statement itself.  Returns the CASE_LABEL_EXPR created, or
4210    ERROR_MARK_NODE if no CASE_LABEL_EXPR is created.  */
4211
4212 tree
4213 c_add_case_label (splay_tree cases, tree cond, tree orig_type,
4214                   tree low_value, tree high_value)
4215 {
4216   tree type;
4217   tree label;
4218   tree case_label;
4219   splay_tree_node node;
4220
4221   /* Create the LABEL_DECL itself.  */
4222   label = create_artificial_label ();
4223
4224   /* If there was an error processing the switch condition, bail now
4225      before we get more confused.  */
4226   if (!cond || cond == error_mark_node)
4227     goto error_out;
4228
4229   if ((low_value && TREE_TYPE (low_value)
4230        && POINTER_TYPE_P (TREE_TYPE (low_value)))
4231       || (high_value && TREE_TYPE (high_value)
4232           && POINTER_TYPE_P (TREE_TYPE (high_value))))
4233     {
4234       error ("pointers are not permitted as case values");
4235       goto error_out;
4236     }
4237
4238   /* Case ranges are a GNU extension.  */
4239   if (high_value && pedantic)
4240     pedwarn ("range expressions in switch statements are non-standard");
4241
4242   type = TREE_TYPE (cond);
4243   if (low_value)
4244     {
4245       low_value = check_case_value (low_value);
4246       low_value = convert_and_check (type, low_value);
4247       if (low_value == error_mark_node)
4248         goto error_out;
4249     }
4250   if (high_value)
4251     {
4252       high_value = check_case_value (high_value);
4253       high_value = convert_and_check (type, high_value);
4254       if (high_value == error_mark_node)
4255         goto error_out;
4256     }
4257
4258   if (low_value && high_value)
4259     {
4260       /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
4261          really a case range, even though it was written that way.
4262          Remove the HIGH_VALUE to simplify later processing.  */
4263       if (tree_int_cst_equal (low_value, high_value))
4264         high_value = NULL_TREE;
4265       else if (!tree_int_cst_lt (low_value, high_value))
4266         warning (0, "empty range specified");
4267     }
4268
4269   /* See if the case is in range of the type of the original testing
4270      expression.  If both low_value and high_value are out of range,
4271      don't insert the case label and return NULL_TREE.  */
4272   if (low_value
4273       && !check_case_bounds (type, orig_type,
4274                              &low_value, high_value ? &high_value : NULL))
4275     return NULL_TREE;
4276
4277   /* Look up the LOW_VALUE in the table of case labels we already
4278      have.  */
4279   node = splay_tree_lookup (cases, (splay_tree_key) low_value);
4280   /* If there was not an exact match, check for overlapping ranges.
4281      There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
4282      that's a `default' label and the only overlap is an exact match.  */
4283   if (!node && (low_value || high_value))
4284     {
4285       splay_tree_node low_bound;
4286       splay_tree_node high_bound;
4287
4288       /* Even though there wasn't an exact match, there might be an
4289          overlap between this case range and another case range.
4290          Since we've (inductively) not allowed any overlapping case
4291          ranges, we simply need to find the greatest low case label
4292          that is smaller that LOW_VALUE, and the smallest low case
4293          label that is greater than LOW_VALUE.  If there is an overlap
4294          it will occur in one of these two ranges.  */
4295       low_bound = splay_tree_predecessor (cases,
4296                                           (splay_tree_key) low_value);
4297       high_bound = splay_tree_successor (cases,
4298                                          (splay_tree_key) low_value);
4299
4300       /* Check to see if the LOW_BOUND overlaps.  It is smaller than
4301          the LOW_VALUE, so there is no need to check unless the
4302          LOW_BOUND is in fact itself a case range.  */
4303       if (low_bound
4304           && CASE_HIGH ((tree) low_bound->value)
4305           && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
4306                                     low_value) >= 0)
4307         node = low_bound;
4308       /* Check to see if the HIGH_BOUND overlaps.  The low end of that
4309          range is bigger than the low end of the current range, so we
4310          are only interested if the current range is a real range, and
4311          not an ordinary case label.  */
4312       else if (high_bound
4313                && high_value
4314                && (tree_int_cst_compare ((tree) high_bound->key,
4315                                          high_value)
4316                    <= 0))
4317         node = high_bound;
4318     }
4319   /* If there was an overlap, issue an error.  */
4320   if (node)
4321     {
4322       tree duplicate = CASE_LABEL ((tree) node->value);
4323
4324       if (high_value)
4325         {
4326           error ("duplicate (or overlapping) case value");
4327           error ("%Jthis is the first entry overlapping that value", duplicate);
4328         }
4329       else if (low_value)
4330         {
4331           error ("duplicate case value") ;
4332           error ("%Jpreviously used here", duplicate);
4333         }
4334       else
4335         {
4336           error ("multiple default labels in one switch");
4337           error ("%Jthis is the first default label", duplicate);
4338         }
4339       goto error_out;
4340     }
4341
4342   /* Add a CASE_LABEL to the statement-tree.  */
4343   case_label = add_stmt (build_case_label (low_value, high_value, label));
4344   /* Register this case label in the splay tree.  */
4345   splay_tree_insert (cases,
4346                      (splay_tree_key) low_value,
4347                      (splay_tree_value) case_label);
4348
4349   return case_label;
4350
4351  error_out:
4352   /* Add a label so that the back-end doesn't think that the beginning of
4353      the switch is unreachable.  Note that we do not add a case label, as
4354      that just leads to duplicates and thence to failure later on.  */
4355   if (!cases->root)
4356     {
4357       tree t = create_artificial_label ();
4358       add_stmt (build_stmt (LABEL_EXPR, t));
4359     }
4360   return error_mark_node;
4361 }
4362
4363 /* Subroutines of c_do_switch_warnings, called via splay_tree_foreach.
4364    Used to verify that case values match up with enumerator values.  */
4365
4366 static void
4367 match_case_to_enum_1 (tree key, tree type, tree label)
4368 {
4369   char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1];
4370
4371   /* ??? Not working too hard to print the double-word value.
4372      Should perhaps be done with %lwd in the diagnostic routines?  */
4373   if (TREE_INT_CST_HIGH (key) == 0)
4374     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED,
4375               TREE_INT_CST_LOW (key));
4376   else if (!TYPE_UNSIGNED (type)
4377            && TREE_INT_CST_HIGH (key) == -1
4378            && TREE_INT_CST_LOW (key) != 0)
4379     snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED,
4380               -TREE_INT_CST_LOW (key));
4381   else
4382     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX,
4383               TREE_INT_CST_HIGH (key), TREE_INT_CST_LOW (key));
4384
4385   if (TYPE_NAME (type) == 0)
4386     warning (0, "%Jcase value %qs not in enumerated type",
4387              CASE_LABEL (label), buf);
4388   else
4389     warning (0, "%Jcase value %qs not in enumerated type %qT",
4390              CASE_LABEL (label), buf, type);
4391 }
4392
4393 /* Subroutine of c_do_switch_warnings, called via splay_tree_foreach.
4394    Used to verify that case values match up with enumerator values.  */
4395
4396 static int
4397 match_case_to_enum (splay_tree_node node, void *data)
4398 {
4399   tree label = (tree) node->value;
4400   tree type = (tree) data;
4401
4402   /* Skip default case.  */
4403   if (!CASE_LOW (label))
4404     return 0;
4405
4406   /* If CASE_LOW_SEEN is not set, that means CASE_LOW did not appear
4407      when we did our enum->case scan.  Reset our scratch bit after.  */
4408   if (!CASE_LOW_SEEN (label))
4409     match_case_to_enum_1 (CASE_LOW (label), type, label);
4410   else
4411     CASE_LOW_SEEN (label) = 0;
4412
4413   /* If CASE_HIGH is non-null, we have a range.  If CASE_HIGH_SEEN is
4414      not set, that means that CASE_HIGH did not appear when we did our
4415      enum->case scan.  Reset our scratch bit after.  */
4416   if (CASE_HIGH (label))
4417     {
4418       if (!CASE_HIGH_SEEN (label))
4419         match_case_to_enum_1 (CASE_HIGH (label), type, label);
4420       else
4421         CASE_HIGH_SEEN (label) = 0;
4422     }
4423
4424   return 0;
4425 }
4426
4427 /* Handle -Wswitch*.  Called from the front end after parsing the
4428    switch construct.  */
4429 /* ??? Should probably be somewhere generic, since other languages
4430    besides C and C++ would want this.  At the moment, however, C/C++
4431    are the only tree-ssa languages that support enumerations at all,
4432    so the point is moot.  */
4433
4434 void
4435 c_do_switch_warnings (splay_tree cases, location_t switch_location,
4436                       tree type, tree cond)
4437 {
4438   splay_tree_node default_node;
4439   splay_tree_node node;
4440   tree chain;
4441
4442   if (!warn_switch && !warn_switch_enum && !warn_switch_default)
4443     return;
4444
4445   default_node = splay_tree_lookup (cases, (splay_tree_key) NULL);
4446   if (!default_node)
4447     warning (OPT_Wswitch_default, "%Hswitch missing default case",
4448              &switch_location);
4449
4450   /* From here on, we only care about about enumerated types.  */
4451   if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
4452     return;
4453
4454   /* If the switch expression was an enumerated type, check that
4455      exactly all enumeration literals are covered by the cases.
4456      The check is made when -Wswitch was specified and there is no
4457      default case, or when -Wswitch-enum was specified.  */
4458
4459   if (!warn_switch_enum
4460       && !(warn_switch && !default_node))
4461     return;
4462
4463   /* Clearing COND if it is not an integer constant simplifies
4464      the tests inside the loop below.  */
4465   if (TREE_CODE (cond) != INTEGER_CST)
4466     cond = NULL_TREE;
4467
4468   /* The time complexity here is O(N*lg(N)) worst case, but for the
4469       common case of monotonically increasing enumerators, it is
4470       O(N), since the nature of the splay tree will keep the next
4471       element adjacent to the root at all times.  */
4472
4473   for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain))
4474     {
4475       tree value = TREE_VALUE (chain);
4476       node = splay_tree_lookup (cases, (splay_tree_key) value);
4477       if (node)
4478         {
4479           /* Mark the CASE_LOW part of the case entry as seen.  */
4480           tree label = (tree) node->value;
4481           CASE_LOW_SEEN (label) = 1;
4482           continue;
4483         }
4484
4485       /* Even though there wasn't an exact match, there might be a
4486          case range which includes the enumator's value.  */
4487       node = splay_tree_predecessor (cases, (splay_tree_key) value);
4488       if (node && CASE_HIGH ((tree) node->value))
4489         {
4490           tree label = (tree) node->value;
4491           int cmp = tree_int_cst_compare (CASE_HIGH (label), value);
4492           if (cmp >= 0)
4493             {
4494               /* If we match the upper bound exactly, mark the CASE_HIGH
4495                  part of the case entry as seen.  */
4496               if (cmp == 0)
4497                 CASE_HIGH_SEEN (label) = 1;
4498               continue;
4499             }
4500         }
4501
4502       /* We've now determined that this enumerated literal isn't
4503          handled by the case labels of the switch statement.  */
4504
4505       /* If the switch expression is a constant, we only really care
4506          about whether that constant is handled by the switch.  */
4507       if (cond && tree_int_cst_compare (cond, value))
4508         continue;
4509
4510       warning (0, "%Henumeration value %qE not handled in switch",
4511                &switch_location, TREE_PURPOSE (chain));
4512     }
4513
4514   /* Warn if there are case expressions that don't correspond to
4515      enumerators.  This can occur since C and C++ don't enforce
4516      type-checking of assignments to enumeration variables.
4517
4518      The time complexity here is now always O(N) worst case, since
4519      we should have marked both the lower bound and upper bound of
4520      every disjoint case label, with CASE_LOW_SEEN and CASE_HIGH_SEEN
4521      above.  This scan also resets those fields.  */
4522   splay_tree_foreach (cases, match_case_to_enum, type);
4523 }
4524
4525 /* Finish an expression taking the address of LABEL (an
4526    IDENTIFIER_NODE).  Returns an expression for the address.  */
4527
4528 tree
4529 finish_label_address_expr (tree label)
4530 {
4531   tree result;
4532
4533   if (pedantic)
4534     pedwarn ("taking the address of a label is non-standard");
4535
4536   if (label == error_mark_node)
4537     return error_mark_node;
4538
4539   label = lookup_label (label);
4540   if (label == NULL_TREE)
4541     result = null_pointer_node;
4542   else
4543     {
4544       TREE_USED (label) = 1;
4545       result = build1 (ADDR_EXPR, ptr_type_node, label);
4546       /* The current function in not necessarily uninlinable.
4547          Computed gotos are incompatible with inlining, but the value
4548          here could be used only in a diagnostic, for example.  */
4549     }
4550
4551   return result;
4552 }
4553
4554 /* Hook used by expand_expr to expand language-specific tree codes.  */
4555 /* The only things that should go here are bits needed to expand
4556    constant initializers.  Everything else should be handled by the
4557    gimplification routines.  */
4558
4559 rtx
4560 c_expand_expr (tree exp, rtx target, enum machine_mode tmode,
4561                int modifier /* Actually enum_modifier.  */,
4562                rtx *alt_rtl)
4563 {
4564   switch (TREE_CODE (exp))
4565     {
4566     case COMPOUND_LITERAL_EXPR:
4567       {
4568         /* Initialize the anonymous variable declared in the compound
4569            literal, then return the variable.  */
4570         tree decl = COMPOUND_LITERAL_EXPR_DECL (exp);
4571         emit_local_var (decl);
4572         return expand_expr_real (decl, target, tmode, modifier, alt_rtl);
4573       }
4574
4575     default:
4576       gcc_unreachable ();
4577     }
4578 }
4579
4580
4581 /* Generate the RTL for the body of FNDECL.  */
4582
4583 void
4584 c_expand_body (tree fndecl)
4585 {
4586   tree_rest_of_compilation (fndecl);
4587 }
4588
4589 /* Hook used by staticp to handle language-specific tree codes.  */
4590
4591 tree
4592 c_staticp (tree exp)
4593 {
4594   return (TREE_CODE (exp) == COMPOUND_LITERAL_EXPR
4595           && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp))
4596           ? exp : NULL);
4597 }
4598 \f
4599
4600 /* Given a boolean expression ARG, return a tree representing an increment
4601    or decrement (as indicated by CODE) of ARG.  The front end must check for
4602    invalid cases (e.g., decrement in C++).  */
4603 tree
4604 boolean_increment (enum tree_code code, tree arg)
4605 {
4606   tree val;
4607   tree true_res = build_int_cst (TREE_TYPE (arg), 1);
4608
4609   arg = stabilize_reference (arg);
4610   switch (code)
4611     {
4612     case PREINCREMENT_EXPR:
4613       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
4614       break;
4615     case POSTINCREMENT_EXPR:
4616       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
4617       arg = save_expr (arg);
4618       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
4619       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
4620       break;
4621     case PREDECREMENT_EXPR:
4622       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
4623                     invert_truthvalue (arg));
4624       break;
4625     case POSTDECREMENT_EXPR:
4626       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
4627                     invert_truthvalue (arg));
4628       arg = save_expr (arg);
4629       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
4630       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
4631       break;
4632     default:
4633       gcc_unreachable ();
4634     }
4635   TREE_SIDE_EFFECTS (val) = 1;
4636   return val;
4637 }
4638 \f
4639 /* Built-in macros for stddef.h, that require macros defined in this
4640    file.  */
4641 void
4642 c_stddef_cpp_builtins(void)
4643 {
4644   builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0);
4645   builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0);
4646   builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0);
4647   builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0);
4648   builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0);
4649   builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0);
4650 }
4651
4652 static void
4653 c_init_attributes (void)
4654 {
4655   /* Fill in the built_in_attributes array.  */
4656 #define DEF_ATTR_NULL_TREE(ENUM)                                \
4657   built_in_attributes[(int) ENUM] = NULL_TREE;
4658 #define DEF_ATTR_INT(ENUM, VALUE)                               \
4659   built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
4660 #define DEF_ATTR_IDENT(ENUM, STRING)                            \
4661   built_in_attributes[(int) ENUM] = get_identifier (STRING);
4662 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
4663   built_in_attributes[(int) ENUM]                       \
4664     = tree_cons (built_in_attributes[(int) PURPOSE],    \
4665                  built_in_attributes[(int) VALUE],      \
4666                  built_in_attributes[(int) CHAIN]);
4667 #include "builtin-attrs.def"
4668 #undef DEF_ATTR_NULL_TREE
4669 #undef DEF_ATTR_INT
4670 #undef DEF_ATTR_IDENT
4671 #undef DEF_ATTR_TREE_LIST
4672 }
4673
4674 /* Attribute handlers common to C front ends.  */
4675
4676 /* Handle a "packed" attribute; arguments as in
4677    struct attribute_spec.handler.  */
4678
4679 static tree
4680 handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4681                          int flags, bool *no_add_attrs)
4682 {
4683   if (TYPE_P (*node))
4684     {
4685       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4686         *node = build_variant_type_copy (*node);
4687       TYPE_PACKED (*node) = 1;
4688     }
4689   else if (TREE_CODE (*node) == FIELD_DECL)
4690     {
4691       if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT)
4692         warning (OPT_Wattributes,
4693                  "%qE attribute ignored for field of type %qT",
4694                  name, TREE_TYPE (*node));
4695       else
4696         DECL_PACKED (*node) = 1;
4697     }
4698   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
4699      used for DECL_REGISTER.  It wouldn't mean anything anyway.
4700      We can't set DECL_PACKED on the type of a TYPE_DECL, because
4701      that changes what the typedef is typing.  */
4702   else
4703     {
4704       warning (OPT_Wattributes, "%qE attribute ignored", name);
4705       *no_add_attrs = true;
4706     }
4707
4708   return NULL_TREE;
4709 }
4710
4711 /* Handle a "nocommon" attribute; arguments as in
4712    struct attribute_spec.handler.  */
4713
4714 static tree
4715 handle_nocommon_attribute (tree *node, tree name,
4716                            tree ARG_UNUSED (args),
4717                            int ARG_UNUSED (flags), bool *no_add_attrs)
4718 {
4719   if (TREE_CODE (*node) == VAR_DECL)
4720     DECL_COMMON (*node) = 0;
4721   else
4722     {
4723       warning (OPT_Wattributes, "%qE attribute ignored", name);
4724       *no_add_attrs = true;
4725     }
4726
4727   return NULL_TREE;
4728 }
4729
4730 /* Handle a "common" attribute; arguments as in
4731    struct attribute_spec.handler.  */
4732
4733 static tree
4734 handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4735                          int ARG_UNUSED (flags), bool *no_add_attrs)
4736 {
4737   if (TREE_CODE (*node) == VAR_DECL)
4738     DECL_COMMON (*node) = 1;
4739   else
4740     {
4741       warning (OPT_Wattributes, "%qE attribute ignored", name);
4742       *no_add_attrs = true;
4743     }
4744
4745   return NULL_TREE;
4746 }
4747
4748 /* Handle a "noreturn" attribute; arguments as in
4749    struct attribute_spec.handler.  */
4750
4751 static tree
4752 handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4753                            int ARG_UNUSED (flags), bool *no_add_attrs)
4754 {
4755   tree type = TREE_TYPE (*node);
4756
4757   /* See FIXME comment in c_common_attribute_table.  */
4758   if (TREE_CODE (*node) == FUNCTION_DECL)
4759     TREE_THIS_VOLATILE (*node) = 1;
4760   else if (TREE_CODE (type) == POINTER_TYPE
4761            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4762     TREE_TYPE (*node)
4763       = build_pointer_type
4764         (build_type_variant (TREE_TYPE (type),
4765                              TYPE_READONLY (TREE_TYPE (type)), 1));
4766   else
4767     {
4768       warning (OPT_Wattributes, "%qE attribute ignored", name);
4769       *no_add_attrs = true;
4770     }
4771
4772   return NULL_TREE;
4773 }
4774
4775 /* Handle a "hot" and attribute; arguments as in
4776    struct attribute_spec.handler.  */
4777
4778 static tree
4779 handle_hot_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4780                           int ARG_UNUSED (flags), bool *no_add_attrs)
4781 {
4782   if (TREE_CODE (*node) == FUNCTION_DECL)
4783     {
4784       if (lookup_attribute ("cold", DECL_ATTRIBUTES (*node)) != NULL)
4785         {
4786           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
4787                    name, "cold");
4788           *no_add_attrs = true;
4789         }
4790       /* Do nothing else, just set the attribute.  We'll get at
4791          it later with lookup_attribute.  */
4792     }
4793   else
4794     {
4795       warning (OPT_Wattributes, "%qE attribute ignored", name);
4796       *no_add_attrs = true;
4797     }
4798
4799   return NULL_TREE;
4800 }
4801 /* Handle a "cold" and attribute; arguments as in
4802    struct attribute_spec.handler.  */
4803
4804 static tree
4805 handle_cold_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4806                        int ARG_UNUSED (flags), bool *no_add_attrs)
4807 {
4808   if (TREE_CODE (*node) == FUNCTION_DECL)
4809     {
4810       if (lookup_attribute ("hot", DECL_ATTRIBUTES (*node)) != NULL)
4811         {
4812           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
4813                    name, "hot");
4814           *no_add_attrs = true;
4815         }
4816       /* Do nothing else, just set the attribute.  We'll get at
4817          it later with lookup_attribute.  */
4818     }
4819   else
4820     {
4821       warning (OPT_Wattributes, "%qE attribute ignored", name);
4822       *no_add_attrs = true;
4823     }
4824
4825   return NULL_TREE;
4826 }
4827
4828 /* Handle a "noinline" attribute; arguments as in
4829    struct attribute_spec.handler.  */
4830
4831 static tree
4832 handle_noinline_attribute (tree *node, tree name,
4833                            tree ARG_UNUSED (args),
4834                            int ARG_UNUSED (flags), bool *no_add_attrs)
4835 {
4836   if (TREE_CODE (*node) == FUNCTION_DECL)
4837     DECL_UNINLINABLE (*node) = 1;
4838   else
4839     {
4840       warning (OPT_Wattributes, "%qE attribute ignored", name);
4841       *no_add_attrs = true;
4842     }
4843
4844   return NULL_TREE;
4845 }
4846
4847 /* Handle a "always_inline" attribute; arguments as in
4848    struct attribute_spec.handler.  */
4849
4850 static tree
4851 handle_always_inline_attribute (tree *node, tree name,
4852                                 tree ARG_UNUSED (args),
4853                                 int ARG_UNUSED (flags),
4854                                 bool *no_add_attrs)
4855 {
4856   if (TREE_CODE (*node) == FUNCTION_DECL)
4857     {
4858       /* Set the attribute and mark it for disregarding inline
4859          limits.  */
4860       DECL_DISREGARD_INLINE_LIMITS (*node) = 1;
4861     }
4862   else
4863     {
4864       warning (OPT_Wattributes, "%qE attribute ignored", name);
4865       *no_add_attrs = true;
4866     }
4867
4868   return NULL_TREE;
4869 }
4870
4871 /* Handle a "gnu_inline" attribute; arguments as in
4872    struct attribute_spec.handler.  */
4873
4874 static tree
4875 handle_gnu_inline_attribute (tree *node, tree name,
4876                              tree ARG_UNUSED (args),
4877                              int ARG_UNUSED (flags),
4878                              bool *no_add_attrs)
4879 {
4880   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
4881     {
4882       /* Do nothing else, just set the attribute.  We'll get at
4883          it later with lookup_attribute.  */
4884     }
4885   else
4886     {
4887       warning (OPT_Wattributes, "%qE attribute ignored", name);
4888       *no_add_attrs = true;
4889     }
4890
4891   return NULL_TREE;
4892 }
4893
4894 /* Handle a "flatten" attribute; arguments as in
4895    struct attribute_spec.handler.  */
4896
4897 static tree
4898 handle_flatten_attribute (tree *node, tree name,
4899                           tree args ATTRIBUTE_UNUSED,
4900                           int flags ATTRIBUTE_UNUSED, bool *no_add_attrs)
4901 {
4902   if (TREE_CODE (*node) == FUNCTION_DECL)
4903     /* Do nothing else, just set the attribute.  We'll get at
4904        it later with lookup_attribute.  */
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
4916 /* Handle a "used" attribute; arguments as in
4917    struct attribute_spec.handler.  */
4918
4919 static tree
4920 handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
4921                        int ARG_UNUSED (flags), bool *no_add_attrs)
4922 {
4923   tree node = *pnode;
4924
4925   if (TREE_CODE (node) == FUNCTION_DECL
4926       || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node)))
4927     {
4928       TREE_USED (node) = 1;
4929       DECL_PRESERVE_P (node) = 1;
4930     }
4931   else
4932     {
4933       warning (OPT_Wattributes, "%qE attribute ignored", name);
4934       *no_add_attrs = true;
4935     }
4936
4937   return NULL_TREE;
4938 }
4939
4940 /* Handle a "unused" attribute; arguments as in
4941    struct attribute_spec.handler.  */
4942
4943 static tree
4944 handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4945                          int flags, bool *no_add_attrs)
4946 {
4947   if (DECL_P (*node))
4948     {
4949       tree decl = *node;
4950
4951       if (TREE_CODE (decl) == PARM_DECL
4952           || TREE_CODE (decl) == VAR_DECL
4953           || TREE_CODE (decl) == FUNCTION_DECL
4954           || TREE_CODE (decl) == LABEL_DECL
4955           || TREE_CODE (decl) == TYPE_DECL)
4956         TREE_USED (decl) = 1;
4957       else
4958         {
4959           warning (OPT_Wattributes, "%qE attribute ignored", name);
4960           *no_add_attrs = true;
4961         }
4962     }
4963   else
4964     {
4965       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4966         *node = build_variant_type_copy (*node);
4967       TREE_USED (*node) = 1;
4968     }
4969
4970   return NULL_TREE;
4971 }
4972
4973 /* Handle a "externally_visible" attribute; arguments as in
4974    struct attribute_spec.handler.  */
4975
4976 static tree
4977 handle_externally_visible_attribute (tree *pnode, tree name,
4978                                      tree ARG_UNUSED (args),
4979                                      int ARG_UNUSED (flags),
4980                                      bool *no_add_attrs)
4981 {
4982   tree node = *pnode;
4983
4984   if (TREE_CODE (node) == FUNCTION_DECL || TREE_CODE (node) == VAR_DECL)
4985     {
4986       if ((!TREE_STATIC (node) && TREE_CODE (node) != FUNCTION_DECL
4987            && !DECL_EXTERNAL (node)) || !TREE_PUBLIC (node))
4988         {
4989           warning (OPT_Wattributes,
4990                    "%qE attribute have effect only on public objects", name);
4991           *no_add_attrs = true;
4992         }
4993     }
4994   else
4995     {
4996       warning (OPT_Wattributes, "%qE attribute ignored", name);
4997       *no_add_attrs = true;
4998     }
4999
5000   return NULL_TREE;
5001 }
5002
5003 /* Handle a "const" attribute; arguments as in
5004    struct attribute_spec.handler.  */
5005
5006 static tree
5007 handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5008                         int ARG_UNUSED (flags), bool *no_add_attrs)
5009 {
5010   tree type = TREE_TYPE (*node);
5011
5012   /* See FIXME comment on noreturn in c_common_attribute_table.  */
5013   if (TREE_CODE (*node) == FUNCTION_DECL)
5014     TREE_READONLY (*node) = 1;
5015   else if (TREE_CODE (type) == POINTER_TYPE
5016            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
5017     TREE_TYPE (*node)
5018       = build_pointer_type
5019         (build_type_variant (TREE_TYPE (type), 1,
5020                              TREE_THIS_VOLATILE (TREE_TYPE (type))));
5021   else
5022     {
5023       warning (OPT_Wattributes, "%qE attribute ignored", name);
5024       *no_add_attrs = true;
5025     }
5026
5027   return NULL_TREE;
5028 }
5029
5030 /* Handle a "transparent_union" attribute; arguments as in
5031    struct attribute_spec.handler.  */
5032
5033 static tree
5034 handle_transparent_union_attribute (tree *node, tree name,
5035                                     tree ARG_UNUSED (args), int flags,
5036                                     bool *no_add_attrs)
5037 {
5038   tree type = NULL;
5039
5040   *no_add_attrs = true;
5041
5042   if (DECL_P (*node))
5043     {
5044       if (TREE_CODE (*node) != TYPE_DECL)
5045         goto ignored;
5046       node = &TREE_TYPE (*node);
5047       type = *node;
5048     }
5049   else if (TYPE_P (*node))
5050     type = *node;
5051   else
5052     goto ignored;
5053
5054   if (TREE_CODE (type) == UNION_TYPE)
5055     {
5056       /* When IN_PLACE is set, leave the check for FIELDS and MODE to
5057          the code in finish_struct.  */
5058       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5059         {
5060           if (TYPE_FIELDS (type) == NULL_TREE
5061               || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type)))
5062             goto ignored;
5063
5064           /* A type variant isn't good enough, since we don't a cast
5065              to such a type removed as a no-op.  */
5066           *node = type = build_duplicate_type (type);
5067         }
5068
5069       TYPE_TRANSPARENT_UNION (type) = 1;
5070       return NULL_TREE;
5071     }
5072
5073  ignored:
5074   warning (OPT_Wattributes, "%qE attribute ignored", name);
5075   return NULL_TREE;
5076 }
5077
5078 /* Subroutine of handle_{con,de}structor_attribute.  Evaluate ARGS to
5079    get the requested priority for a constructor or destructor,
5080    possibly issuing diagnostics for invalid or reserved
5081    priorities.  */
5082
5083 static priority_type
5084 get_priority (tree args, bool is_destructor)
5085 {
5086   HOST_WIDE_INT pri;
5087   tree arg;
5088
5089   if (!args)
5090     return DEFAULT_INIT_PRIORITY;
5091
5092   if (!SUPPORTS_INIT_PRIORITY)
5093     {
5094       if (is_destructor)
5095         error ("destructor priorities are not supported");
5096       else
5097         error ("constructor priorities are not supported");
5098       return DEFAULT_INIT_PRIORITY;
5099     }
5100
5101   arg = TREE_VALUE (args);
5102   if (!host_integerp (arg, /*pos=*/0)
5103       || !INTEGRAL_TYPE_P (TREE_TYPE (arg)))
5104     goto invalid;
5105
5106   pri = tree_low_cst (TREE_VALUE (args), /*pos=*/0);
5107   if (pri < 0 || pri > MAX_INIT_PRIORITY)
5108     goto invalid;
5109
5110   if (pri <= MAX_RESERVED_INIT_PRIORITY)
5111     {
5112       if (is_destructor)
5113         warning (0,
5114                  "destructor priorities from 0 to %d are reserved "
5115                  "for the implementation",
5116                  MAX_RESERVED_INIT_PRIORITY);
5117       else
5118         warning (0,
5119                  "constructor priorities from 0 to %d are reserved "
5120                  "for the implementation",
5121                  MAX_RESERVED_INIT_PRIORITY);
5122     }
5123   return pri;
5124
5125  invalid:
5126   if (is_destructor)
5127     error ("destructor priorities must be integers from 0 to %d inclusive",
5128            MAX_INIT_PRIORITY);
5129   else
5130     error ("constructor priorities must be integers from 0 to %d inclusive",
5131            MAX_INIT_PRIORITY);
5132   return DEFAULT_INIT_PRIORITY;
5133 }
5134
5135 /* Handle a "constructor" attribute; arguments as in
5136    struct attribute_spec.handler.  */
5137
5138 static tree
5139 handle_constructor_attribute (tree *node, tree name, tree args,
5140                               int ARG_UNUSED (flags),
5141                               bool *no_add_attrs)
5142 {
5143   tree decl = *node;
5144   tree type = TREE_TYPE (decl);
5145
5146   if (TREE_CODE (decl) == FUNCTION_DECL
5147       && TREE_CODE (type) == FUNCTION_TYPE
5148       && decl_function_context (decl) == 0)
5149     {
5150       priority_type priority;
5151       DECL_STATIC_CONSTRUCTOR (decl) = 1;
5152       priority = get_priority (args, /*is_destructor=*/false);
5153       SET_DECL_INIT_PRIORITY (decl, priority);
5154       TREE_USED (decl) = 1;
5155     }
5156   else
5157     {
5158       warning (OPT_Wattributes, "%qE attribute ignored", name);
5159       *no_add_attrs = true;
5160     }
5161
5162   return NULL_TREE;
5163 }
5164
5165 /* Handle a "destructor" attribute; arguments as in
5166    struct attribute_spec.handler.  */
5167
5168 static tree
5169 handle_destructor_attribute (tree *node, tree name, tree args,
5170                              int ARG_UNUSED (flags),
5171                              bool *no_add_attrs)
5172 {
5173   tree decl = *node;
5174   tree type = TREE_TYPE (decl);
5175
5176   if (TREE_CODE (decl) == FUNCTION_DECL
5177       && TREE_CODE (type) == FUNCTION_TYPE
5178       && decl_function_context (decl) == 0)
5179     {
5180       priority_type priority;
5181       DECL_STATIC_DESTRUCTOR (decl) = 1;
5182       priority = get_priority (args, /*is_destructor=*/true);
5183       SET_DECL_FINI_PRIORITY (decl, priority);
5184       TREE_USED (decl) = 1;
5185     }
5186   else
5187     {
5188       warning (OPT_Wattributes, "%qE attribute ignored", name);
5189       *no_add_attrs = true;
5190     }
5191
5192   return NULL_TREE;
5193 }
5194
5195 /* Handle a "mode" attribute; arguments as in
5196    struct attribute_spec.handler.  */
5197
5198 static tree
5199 handle_mode_attribute (tree *node, tree name, tree args,
5200                        int ARG_UNUSED (flags), bool *no_add_attrs)
5201 {
5202   tree type = *node;
5203
5204   *no_add_attrs = true;
5205
5206   if (TREE_CODE (TREE_VALUE (args)) != IDENTIFIER_NODE)
5207     warning (OPT_Wattributes, "%qE attribute ignored", name);
5208   else
5209     {
5210       int j;
5211       const char *p = IDENTIFIER_POINTER (TREE_VALUE (args));
5212       int len = strlen (p);
5213       enum machine_mode mode = VOIDmode;
5214       tree typefm;
5215       bool valid_mode;
5216
5217       if (len > 4 && p[0] == '_' && p[1] == '_'
5218           && p[len - 1] == '_' && p[len - 2] == '_')
5219         {
5220           char *newp = (char *) alloca (len - 1);
5221
5222           strcpy (newp, &p[2]);
5223           newp[len - 4] = '\0';
5224           p = newp;
5225         }
5226
5227       /* Change this type to have a type with the specified mode.
5228          First check for the special modes.  */
5229       if (!strcmp (p, "byte"))
5230         mode = byte_mode;
5231       else if (!strcmp (p, "word"))
5232         mode = word_mode;
5233       else if (!strcmp (p, "pointer"))
5234         mode = ptr_mode;
5235       else if (!strcmp (p, "libgcc_cmp_return"))
5236         mode = targetm.libgcc_cmp_return_mode ();
5237       else if (!strcmp (p, "libgcc_shift_count"))
5238         mode = targetm.libgcc_shift_count_mode ();
5239       else
5240         for (j = 0; j < NUM_MACHINE_MODES; j++)
5241           if (!strcmp (p, GET_MODE_NAME (j)))
5242             {
5243               mode = (enum machine_mode) j;
5244               break;
5245             }
5246
5247       if (mode == VOIDmode)
5248         {
5249           error ("unknown machine mode %qs", p);
5250           return NULL_TREE;
5251         }
5252
5253       valid_mode = false;
5254       switch (GET_MODE_CLASS (mode))
5255         {
5256         case MODE_INT:
5257         case MODE_PARTIAL_INT:
5258         case MODE_FLOAT:
5259         case MODE_DECIMAL_FLOAT:
5260         case MODE_FRACT:
5261         case MODE_UFRACT:
5262         case MODE_ACCUM:
5263         case MODE_UACCUM:
5264           valid_mode = targetm.scalar_mode_supported_p (mode);
5265           break;
5266
5267         case MODE_COMPLEX_INT:
5268         case MODE_COMPLEX_FLOAT:
5269           valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode));
5270           break;
5271
5272         case MODE_VECTOR_INT:
5273         case MODE_VECTOR_FLOAT:
5274         case MODE_VECTOR_FRACT:
5275         case MODE_VECTOR_UFRACT:
5276         case MODE_VECTOR_ACCUM:
5277         case MODE_VECTOR_UACCUM:
5278           warning (OPT_Wattributes, "specifying vector types with "
5279                    "__attribute__ ((mode)) is deprecated");
5280           warning (OPT_Wattributes,
5281                    "use __attribute__ ((vector_size)) instead");
5282           valid_mode = vector_mode_valid_p (mode);
5283           break;
5284
5285         default:
5286           break;
5287         }
5288       if (!valid_mode)
5289         {
5290           error ("unable to emulate %qs", p);
5291           return NULL_TREE;
5292         }
5293
5294       if (POINTER_TYPE_P (type))
5295         {
5296           tree (*fn)(tree, enum machine_mode, bool);
5297
5298           if (!targetm.valid_pointer_mode (mode))
5299             {
5300               error ("invalid pointer mode %qs", p);
5301               return NULL_TREE;
5302             }
5303
5304           if (TREE_CODE (type) == POINTER_TYPE)
5305             fn = build_pointer_type_for_mode;
5306           else
5307             fn = build_reference_type_for_mode;
5308           typefm = fn (TREE_TYPE (type), mode, false);
5309         }
5310       else
5311         {
5312           /* For fixed-point modes, we need to test if the signness of type
5313              and the machine mode are consistent.  */
5314           if (ALL_FIXED_POINT_MODE_P (mode)
5315               && TYPE_UNSIGNED (type) != UNSIGNED_FIXED_POINT_MODE_P (mode))
5316             {
5317               error ("signness of type and machine mode %qs don't match", p);
5318               return NULL_TREE;
5319             }
5320           /* For fixed-point modes, we need to pass saturating info.  */
5321           typefm = lang_hooks.types.type_for_mode (mode,
5322                         ALL_FIXED_POINT_MODE_P (mode) ? TYPE_SATURATING (type)
5323                                                       : TYPE_UNSIGNED (type));
5324         }
5325
5326       if (typefm == NULL_TREE)
5327         {
5328           error ("no data type for mode %qs", p);
5329           return NULL_TREE;
5330         }
5331       else if (TREE_CODE (type) == ENUMERAL_TYPE)
5332         {
5333           /* For enumeral types, copy the precision from the integer
5334              type returned above.  If not an INTEGER_TYPE, we can't use
5335              this mode for this type.  */
5336           if (TREE_CODE (typefm) != INTEGER_TYPE)
5337             {
5338               error ("cannot use mode %qs for enumeral types", p);
5339               return NULL_TREE;
5340             }
5341
5342           if (flags & ATTR_FLAG_TYPE_IN_PLACE)
5343             {
5344               TYPE_PRECISION (type) = TYPE_PRECISION (typefm);
5345               typefm = type;
5346             }
5347           else
5348             {
5349               /* We cannot build a type variant, as there's code that assumes
5350                  that TYPE_MAIN_VARIANT has the same mode.  This includes the
5351                  debug generators.  Instead, create a subrange type.  This
5352                  results in all of the enumeral values being emitted only once
5353                  in the original, and the subtype gets them by reference.  */
5354               if (TYPE_UNSIGNED (type))
5355                 typefm = make_unsigned_type (TYPE_PRECISION (typefm));
5356               else
5357                 typefm = make_signed_type (TYPE_PRECISION (typefm));
5358               TREE_TYPE (typefm) = type;
5359             }
5360         }
5361       else if (VECTOR_MODE_P (mode)
5362                ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm))
5363                : TREE_CODE (type) != TREE_CODE (typefm))
5364         {
5365           error ("mode %qs applied to inappropriate type", p);
5366           return NULL_TREE;
5367         }
5368
5369       *node = typefm;
5370     }
5371
5372   return NULL_TREE;
5373 }
5374
5375 /* Handle a "section" attribute; arguments as in
5376    struct attribute_spec.handler.  */
5377
5378 static tree
5379 handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5380                           int ARG_UNUSED (flags), bool *no_add_attrs)
5381 {
5382   tree decl = *node;
5383
5384   if (targetm.have_named_sections)
5385     {
5386       user_defined_section_attribute = true;
5387
5388       if ((TREE_CODE (decl) == FUNCTION_DECL
5389            || TREE_CODE (decl) == VAR_DECL)
5390           && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
5391         {
5392           if (TREE_CODE (decl) == VAR_DECL
5393               && current_function_decl != NULL_TREE
5394               && !TREE_STATIC (decl))
5395             {
5396               error ("%Jsection attribute cannot be specified for "
5397                      "local variables", decl);
5398               *no_add_attrs = true;
5399             }
5400
5401           /* The decl may have already been given a section attribute
5402              from a previous declaration.  Ensure they match.  */
5403           else if (DECL_SECTION_NAME (decl) != NULL_TREE
5404                    && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
5405                               TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
5406             {
5407               error ("section of %q+D conflicts with previous declaration",
5408                      *node);
5409               *no_add_attrs = true;
5410             }
5411           else
5412             DECL_SECTION_NAME (decl) = TREE_VALUE (args);
5413         }
5414       else
5415         {
5416           error ("section attribute not allowed for %q+D", *node);
5417           *no_add_attrs = true;
5418         }
5419     }
5420   else
5421     {
5422       error ("%Jsection attributes are not supported for this target", *node);
5423       *no_add_attrs = true;
5424     }
5425
5426   return NULL_TREE;
5427 }
5428
5429 /* Handle a "aligned" attribute; arguments as in
5430    struct attribute_spec.handler.  */
5431
5432 static tree
5433 handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5434                           int flags, bool *no_add_attrs)
5435 {
5436   tree decl = NULL_TREE;
5437   tree *type = NULL;
5438   int is_type = 0;
5439   tree align_expr = (args ? TREE_VALUE (args)
5440                      : size_int (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
5441   int i;
5442
5443   if (DECL_P (*node))
5444     {
5445       decl = *node;
5446       type = &TREE_TYPE (decl);
5447       is_type = TREE_CODE (*node) == TYPE_DECL;
5448     }
5449   else if (TYPE_P (*node))
5450     type = node, is_type = 1;
5451
5452   if (TREE_CODE (align_expr) != INTEGER_CST)
5453     {
5454       error ("requested alignment is not a constant");
5455       *no_add_attrs = true;
5456     }
5457   else if ((i = tree_log2 (align_expr)) == -1)
5458     {
5459       error ("requested alignment is not a power of 2");
5460       *no_add_attrs = true;
5461     }
5462   else if (i > HOST_BITS_PER_INT - 2)
5463     {
5464       error ("requested alignment is too large");
5465       *no_add_attrs = true;
5466     }
5467   else if (is_type)
5468     {
5469       /* If we have a TYPE_DECL, then copy the type, so that we
5470          don't accidentally modify a builtin type.  See pushdecl.  */
5471       if (decl && TREE_TYPE (decl) != error_mark_node
5472           && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
5473         {
5474           tree tt = TREE_TYPE (decl);
5475           *type = build_variant_type_copy (*type);
5476           DECL_ORIGINAL_TYPE (decl) = tt;
5477           TYPE_NAME (*type) = decl;
5478           TREE_USED (*type) = TREE_USED (decl);
5479           TREE_TYPE (decl) = *type;
5480         }
5481       else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5482         *type = build_variant_type_copy (*type);
5483
5484       TYPE_ALIGN (*type) = (1 << i) * BITS_PER_UNIT;
5485       TYPE_USER_ALIGN (*type) = 1;
5486     }
5487   else if (! VAR_OR_FUNCTION_DECL_P (decl)
5488            && TREE_CODE (decl) != FIELD_DECL)
5489     {
5490       error ("alignment may not be specified for %q+D", decl);
5491       *no_add_attrs = true;
5492     }
5493   else if (TREE_CODE (decl) == FUNCTION_DECL
5494            && DECL_ALIGN (decl) > (1 << i) * BITS_PER_UNIT)
5495     {
5496       if (DECL_USER_ALIGN (decl))
5497         error ("alignment for %q+D was previously specified as %d "
5498                "and may not be decreased", decl,
5499                DECL_ALIGN (decl) / BITS_PER_UNIT);
5500       else
5501         error ("alignment for %q+D must be at least %d", decl,
5502                DECL_ALIGN (decl) / BITS_PER_UNIT);
5503       *no_add_attrs = true;
5504     }
5505   else
5506     {
5507       DECL_ALIGN (decl) = (1 << i) * BITS_PER_UNIT;
5508       DECL_USER_ALIGN (decl) = 1;
5509     }
5510
5511   return NULL_TREE;
5512 }
5513
5514 /* Handle a "weak" attribute; arguments as in
5515    struct attribute_spec.handler.  */
5516
5517 static tree
5518 handle_weak_attribute (tree *node, tree name,
5519                        tree ARG_UNUSED (args),
5520                        int ARG_UNUSED (flags),
5521                        bool * ARG_UNUSED (no_add_attrs))
5522 {
5523   if (TREE_CODE (*node) == FUNCTION_DECL
5524       || TREE_CODE (*node) == VAR_DECL)
5525     declare_weak (*node);
5526   else
5527     warning (OPT_Wattributes, "%qE attribute ignored", name);
5528
5529
5530   return NULL_TREE;
5531 }
5532
5533 /* Handle an "alias" attribute; arguments as in
5534    struct attribute_spec.handler.  */
5535
5536 static tree
5537 handle_alias_attribute (tree *node, tree name, tree args,
5538                         int ARG_UNUSED (flags), bool *no_add_attrs)
5539 {
5540   tree decl = *node;
5541
5542   if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
5543       || (TREE_CODE (decl) != FUNCTION_DECL
5544           && TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl))
5545       /* A static variable declaration is always a tentative definition,
5546          but the alias is a non-tentative definition which overrides.  */
5547       || (TREE_CODE (decl) != FUNCTION_DECL
5548           && ! TREE_PUBLIC (decl) && DECL_INITIAL (decl)))
5549     {
5550       error ("%q+D defined both normally and as an alias", decl);
5551       *no_add_attrs = true;
5552     }
5553
5554   /* Note that the very first time we process a nested declaration,
5555      decl_function_context will not be set.  Indeed, *would* never
5556      be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that
5557      we do below.  After such frobbery, pushdecl would set the context.
5558      In any case, this is never what we want.  */
5559   else if (decl_function_context (decl) == 0 && current_function_decl == NULL)
5560     {
5561       tree id;
5562
5563       id = TREE_VALUE (args);
5564       if (TREE_CODE (id) != STRING_CST)
5565         {
5566           error ("alias argument not a string");
5567           *no_add_attrs = true;
5568           return NULL_TREE;
5569         }
5570       id = get_identifier (TREE_STRING_POINTER (id));
5571       /* This counts as a use of the object pointed to.  */
5572       TREE_USED (id) = 1;
5573
5574       if (TREE_CODE (decl) == FUNCTION_DECL)
5575         DECL_INITIAL (decl) = error_mark_node;
5576       else
5577         {
5578           if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5579             DECL_EXTERNAL (decl) = 1;
5580           else
5581             DECL_EXTERNAL (decl) = 0;
5582           TREE_STATIC (decl) = 1;
5583         }
5584     }
5585   else
5586     {
5587       warning (OPT_Wattributes, "%qE attribute ignored", name);
5588       *no_add_attrs = true;
5589     }
5590
5591   return NULL_TREE;
5592 }
5593
5594 /* Handle a "weakref" attribute; arguments as in struct
5595    attribute_spec.handler.  */
5596
5597 static tree
5598 handle_weakref_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5599                           int flags, bool *no_add_attrs)
5600 {
5601   tree attr = NULL_TREE;
5602
5603   /* We must ignore the attribute when it is associated with
5604      local-scoped decls, since attribute alias is ignored and many
5605      such symbols do not even have a DECL_WEAK field.  */
5606   if (decl_function_context (*node) || current_function_decl)
5607     {
5608       warning (OPT_Wattributes, "%qE attribute ignored", name);
5609       *no_add_attrs = true;
5610       return NULL_TREE;
5611     }
5612
5613   /* The idea here is that `weakref("name")' mutates into `weakref,
5614      alias("name")', and weakref without arguments, in turn,
5615      implicitly adds weak. */
5616
5617   if (args)
5618     {
5619       attr = tree_cons (get_identifier ("alias"), args, attr);
5620       attr = tree_cons (get_identifier ("weakref"), NULL_TREE, attr);
5621
5622       *no_add_attrs = true;
5623
5624       decl_attributes (node, attr, flags);
5625     }
5626   else
5627     {
5628       if (lookup_attribute ("alias", DECL_ATTRIBUTES (*node)))
5629         error ("%Jweakref attribute must appear before alias attribute",
5630                *node);
5631
5632       /* Can't call declare_weak because it wants this to be TREE_PUBLIC,
5633          and that isn't supported; and because it wants to add it to
5634          the list of weak decls, which isn't helpful.  */
5635       DECL_WEAK (*node) = 1;
5636     }
5637
5638   return NULL_TREE;
5639 }
5640
5641 /* Handle an "visibility" attribute; arguments as in
5642    struct attribute_spec.handler.  */
5643
5644 static tree
5645 handle_visibility_attribute (tree *node, tree name, tree args,
5646                              int ARG_UNUSED (flags),
5647                              bool *ARG_UNUSED (no_add_attrs))
5648 {
5649   tree decl = *node;
5650   tree id = TREE_VALUE (args);
5651   enum symbol_visibility vis;
5652
5653   if (TYPE_P (*node))
5654     {
5655       if (TREE_CODE (*node) == ENUMERAL_TYPE)
5656         /* OK */;
5657       else if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE)
5658         {
5659           warning (OPT_Wattributes, "%qE attribute ignored on non-class types",
5660                    name);
5661           return NULL_TREE;
5662         }
5663       else if (TYPE_FIELDS (*node))
5664         {
5665           error ("%qE attribute ignored because %qT is already defined",
5666                  name, *node);
5667           return NULL_TREE;
5668         }
5669     }
5670   else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl))
5671     {
5672       warning (OPT_Wattributes, "%qE attribute ignored", name);
5673       return NULL_TREE;
5674     }
5675
5676   if (TREE_CODE (id) != STRING_CST)
5677     {
5678       error ("visibility argument not a string");
5679       return NULL_TREE;
5680     }
5681
5682   /*  If this is a type, set the visibility on the type decl.  */
5683   if (TYPE_P (decl))
5684     {
5685       decl = TYPE_NAME (decl);
5686       if (!decl)
5687         return NULL_TREE;
5688       if (TREE_CODE (decl) == IDENTIFIER_NODE)
5689         {
5690            warning (OPT_Wattributes, "%qE attribute ignored on types",
5691                     name);
5692            return NULL_TREE;
5693         }
5694     }
5695
5696   if (strcmp (TREE_STRING_POINTER (id), "default") == 0)
5697     vis = VISIBILITY_DEFAULT;
5698   else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0)
5699     vis = VISIBILITY_INTERNAL;
5700   else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0)
5701     vis = VISIBILITY_HIDDEN;
5702   else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0)
5703     vis = VISIBILITY_PROTECTED;
5704   else
5705     {
5706       error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\"");
5707       vis = VISIBILITY_DEFAULT;
5708     }
5709
5710   if (DECL_VISIBILITY_SPECIFIED (decl)
5711       && vis != DECL_VISIBILITY (decl))
5712     {
5713       tree attributes = (TYPE_P (*node)
5714                          ? TYPE_ATTRIBUTES (*node)
5715                          : DECL_ATTRIBUTES (decl));
5716       if (lookup_attribute ("visibility", attributes))
5717         error ("%qD redeclared with different visibility", decl);
5718       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
5719                && lookup_attribute ("dllimport", attributes))
5720         error ("%qD was declared %qs which implies default visibility",
5721                decl, "dllimport");
5722       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
5723                && lookup_attribute ("dllexport", attributes))
5724         error ("%qD was declared %qs which implies default visibility",
5725                decl, "dllexport");
5726     }
5727
5728   DECL_VISIBILITY (decl) = vis;
5729   DECL_VISIBILITY_SPECIFIED (decl) = 1;
5730
5731   /* Go ahead and attach the attribute to the node as well.  This is needed
5732      so we can determine whether we have VISIBILITY_DEFAULT because the
5733      visibility was not specified, or because it was explicitly overridden
5734      from the containing scope.  */
5735
5736   return NULL_TREE;
5737 }
5738
5739 /* Determine the ELF symbol visibility for DECL, which is either a
5740    variable or a function.  It is an error to use this function if a
5741    definition of DECL is not available in this translation unit.
5742    Returns true if the final visibility has been determined by this
5743    function; false if the caller is free to make additional
5744    modifications.  */
5745
5746 bool
5747 c_determine_visibility (tree decl)
5748 {
5749   gcc_assert (TREE_CODE (decl) == VAR_DECL
5750               || TREE_CODE (decl) == FUNCTION_DECL);
5751
5752   /* If the user explicitly specified the visibility with an
5753      attribute, honor that.  DECL_VISIBILITY will have been set during
5754      the processing of the attribute.  We check for an explicit
5755      attribute, rather than just checking DECL_VISIBILITY_SPECIFIED,
5756      to distinguish the use of an attribute from the use of a "#pragma
5757      GCC visibility push(...)"; in the latter case we still want other
5758      considerations to be able to overrule the #pragma.  */
5759   if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl))
5760       || (TARGET_DLLIMPORT_DECL_ATTRIBUTES
5761           && (lookup_attribute ("dllimport", DECL_ATTRIBUTES (decl))
5762               || lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))))
5763     return true;
5764
5765   /* Set default visibility to whatever the user supplied with
5766      visibility_specified depending on #pragma GCC visibility.  */
5767   if (!DECL_VISIBILITY_SPECIFIED (decl))
5768     {
5769       DECL_VISIBILITY (decl) = default_visibility;
5770       DECL_VISIBILITY_SPECIFIED (decl) = visibility_options.inpragma;
5771     }
5772   return false;
5773 }
5774
5775 /* Handle an "tls_model" attribute; arguments as in
5776    struct attribute_spec.handler.  */
5777
5778 static tree
5779 handle_tls_model_attribute (tree *node, tree name, tree args,
5780                             int ARG_UNUSED (flags), bool *no_add_attrs)
5781 {
5782   tree id;
5783   tree decl = *node;
5784   enum tls_model kind;
5785
5786   *no_add_attrs = true;
5787
5788   if (!DECL_THREAD_LOCAL_P (decl))
5789     {
5790       warning (OPT_Wattributes, "%qE attribute ignored", name);
5791       return NULL_TREE;
5792     }
5793
5794   kind = DECL_TLS_MODEL (decl);
5795   id = TREE_VALUE (args);
5796   if (TREE_CODE (id) != STRING_CST)
5797     {
5798       error ("tls_model argument not a string");
5799       return NULL_TREE;
5800     }
5801
5802   if (!strcmp (TREE_STRING_POINTER (id), "local-exec"))
5803     kind = TLS_MODEL_LOCAL_EXEC;
5804   else if (!strcmp (TREE_STRING_POINTER (id), "initial-exec"))
5805     kind = TLS_MODEL_INITIAL_EXEC;
5806   else if (!strcmp (TREE_STRING_POINTER (id), "local-dynamic"))
5807     kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
5808   else if (!strcmp (TREE_STRING_POINTER (id), "global-dynamic"))
5809     kind = TLS_MODEL_GLOBAL_DYNAMIC;
5810   else
5811     error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\"");
5812
5813   DECL_TLS_MODEL (decl) = kind;
5814   return NULL_TREE;
5815 }
5816
5817 /* Handle a "no_instrument_function" attribute; arguments as in
5818    struct attribute_spec.handler.  */
5819
5820 static tree
5821 handle_no_instrument_function_attribute (tree *node, tree name,
5822                                          tree ARG_UNUSED (args),
5823                                          int ARG_UNUSED (flags),
5824                                          bool *no_add_attrs)
5825 {
5826   tree decl = *node;
5827
5828   if (TREE_CODE (decl) != FUNCTION_DECL)
5829     {
5830       error ("%J%qE attribute applies only to functions", decl, name);
5831       *no_add_attrs = true;
5832     }
5833   else if (DECL_INITIAL (decl))
5834     {
5835       error ("%Jcan%'t set %qE attribute after definition", decl, name);
5836       *no_add_attrs = true;
5837     }
5838   else
5839     DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
5840
5841   return NULL_TREE;
5842 }
5843
5844 /* Handle a "malloc" attribute; arguments as in
5845    struct attribute_spec.handler.  */
5846
5847 static tree
5848 handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5849                          int ARG_UNUSED (flags), bool *no_add_attrs)
5850 {
5851   if (TREE_CODE (*node) == FUNCTION_DECL
5852       && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node))))
5853     DECL_IS_MALLOC (*node) = 1;
5854   else
5855     {
5856       warning (OPT_Wattributes, "%qE attribute ignored", name);
5857       *no_add_attrs = true;
5858     }
5859
5860   return NULL_TREE;
5861 }
5862
5863 /* Handle a "alloc_size" attribute; arguments as in
5864    struct attribute_spec.handler.  */
5865
5866 static tree
5867 handle_alloc_size_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5868                              int ARG_UNUSED (flags), bool *no_add_attrs)
5869 {
5870   tree params = TYPE_ARG_TYPES (*node);
5871   unsigned arg_count = 0;
5872
5873   for (; TREE_CHAIN (params); params = TREE_CHAIN (params))
5874     arg_count ++;
5875
5876   for (; args; args = TREE_CHAIN (args))
5877     {
5878       tree position = TREE_VALUE (args);
5879
5880       if (TREE_CODE (position) != INTEGER_CST
5881           || TREE_INT_CST_HIGH (position)
5882           || TREE_INT_CST_LOW (position) < 1
5883           || TREE_INT_CST_LOW (position) > arg_count )
5884         {
5885           warning (OPT_Wattributes,
5886                    "alloc_size parameter outside range");
5887           *no_add_attrs = true;
5888           return NULL_TREE;
5889         }
5890     }
5891   return NULL_TREE;
5892 }
5893
5894 /* Handle a "returns_twice" attribute; arguments as in
5895    struct attribute_spec.handler.  */
5896
5897 static tree
5898 handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5899                          int ARG_UNUSED (flags), bool *no_add_attrs)
5900 {
5901   if (TREE_CODE (*node) == FUNCTION_DECL)
5902     DECL_IS_RETURNS_TWICE (*node) = 1;
5903   else
5904     {
5905       warning (OPT_Wattributes, "%qE attribute ignored", name);
5906       *no_add_attrs = true;
5907     }
5908
5909   return NULL_TREE;
5910 }
5911
5912 /* Handle a "no_limit_stack" attribute; arguments as in
5913    struct attribute_spec.handler.  */
5914
5915 static tree
5916 handle_no_limit_stack_attribute (tree *node, tree name,
5917                                  tree ARG_UNUSED (args),
5918                                  int ARG_UNUSED (flags),
5919                                  bool *no_add_attrs)
5920 {
5921   tree decl = *node;
5922
5923   if (TREE_CODE (decl) != FUNCTION_DECL)
5924     {
5925       error ("%J%qE attribute applies only to functions", decl, name);
5926       *no_add_attrs = true;
5927     }
5928   else if (DECL_INITIAL (decl))
5929     {
5930       error ("%Jcan%'t set %qE attribute after definition", decl, name);
5931       *no_add_attrs = true;
5932     }
5933   else
5934     DECL_NO_LIMIT_STACK (decl) = 1;
5935
5936   return NULL_TREE;
5937 }
5938
5939 /* Handle a "pure" attribute; arguments as in
5940    struct attribute_spec.handler.  */
5941
5942 static tree
5943 handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5944                        int ARG_UNUSED (flags), bool *no_add_attrs)
5945 {
5946   if (TREE_CODE (*node) == FUNCTION_DECL)
5947     DECL_IS_PURE (*node) = 1;
5948   /* ??? TODO: Support types.  */
5949   else
5950     {
5951       warning (OPT_Wattributes, "%qE attribute ignored", name);
5952       *no_add_attrs = true;
5953     }
5954
5955   return NULL_TREE;
5956 }
5957
5958 /* Handle a "no vops" attribute; arguments as in
5959    struct attribute_spec.handler.  */
5960
5961 static tree
5962 handle_novops_attribute (tree *node, tree ARG_UNUSED (name),
5963                          tree ARG_UNUSED (args), int ARG_UNUSED (flags),
5964                          bool *ARG_UNUSED (no_add_attrs))
5965 {
5966   gcc_assert (TREE_CODE (*node) == FUNCTION_DECL);
5967   DECL_IS_NOVOPS (*node) = 1;
5968   return NULL_TREE;
5969 }
5970
5971 /* Handle a "deprecated" attribute; arguments as in
5972    struct attribute_spec.handler.  */
5973
5974 static tree
5975 handle_deprecated_attribute (tree *node, tree name,
5976                              tree ARG_UNUSED (args), int flags,
5977                              bool *no_add_attrs)
5978 {
5979   tree type = NULL_TREE;
5980   int warn = 0;
5981   tree what = NULL_TREE;
5982
5983   if (DECL_P (*node))
5984     {
5985       tree decl = *node;
5986       type = TREE_TYPE (decl);
5987
5988       if (TREE_CODE (decl) == TYPE_DECL
5989           || TREE_CODE (decl) == PARM_DECL
5990           || TREE_CODE (decl) == VAR_DECL
5991           || TREE_CODE (decl) == FUNCTION_DECL
5992           || TREE_CODE (decl) == FIELD_DECL)
5993         TREE_DEPRECATED (decl) = 1;
5994       else
5995         warn = 1;
5996     }
5997   else if (TYPE_P (*node))
5998     {
5999       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6000         *node = build_variant_type_copy (*node);
6001       TREE_DEPRECATED (*node) = 1;
6002       type = *node;
6003     }
6004   else
6005     warn = 1;
6006
6007   if (warn)
6008     {
6009       *no_add_attrs = true;
6010       if (type && TYPE_NAME (type))
6011         {
6012           if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
6013             what = TYPE_NAME (*node);
6014           else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
6015                    && DECL_NAME (TYPE_NAME (type)))
6016             what = DECL_NAME (TYPE_NAME (type));
6017         }
6018       if (what)
6019         warning (OPT_Wattributes, "%qE attribute ignored for %qE", name, what);
6020       else
6021         warning (OPT_Wattributes, "%qE attribute ignored", name);
6022     }
6023
6024   return NULL_TREE;
6025 }
6026
6027 /* Handle a "vector_size" attribute; arguments as in
6028    struct attribute_spec.handler.  */
6029
6030 static tree
6031 handle_vector_size_attribute (tree *node, tree name, tree args,
6032                               int ARG_UNUSED (flags),
6033                               bool *no_add_attrs)
6034 {
6035   unsigned HOST_WIDE_INT vecsize, nunits;
6036   enum machine_mode orig_mode;
6037   tree type = *node, new_type, size;
6038
6039   *no_add_attrs = true;
6040
6041   size = TREE_VALUE (args);
6042
6043   if (!host_integerp (size, 1))
6044     {
6045       warning (OPT_Wattributes, "%qE attribute ignored", name);
6046       return NULL_TREE;
6047     }
6048
6049   /* Get the vector size (in bytes).  */
6050   vecsize = tree_low_cst (size, 1);
6051
6052   /* We need to provide for vector pointers, vector arrays, and
6053      functions returning vectors.  For example:
6054
6055        __attribute__((vector_size(16))) short *foo;
6056
6057      In this case, the mode is SI, but the type being modified is
6058      HI, so we need to look further.  */
6059
6060   while (POINTER_TYPE_P (type)
6061          || TREE_CODE (type) == FUNCTION_TYPE
6062          || TREE_CODE (type) == METHOD_TYPE
6063          || TREE_CODE (type) == ARRAY_TYPE)
6064     type = TREE_TYPE (type);
6065
6066   /* Get the mode of the type being modified.  */
6067   orig_mode = TYPE_MODE (type);
6068
6069   if (TREE_CODE (type) == RECORD_TYPE
6070       || TREE_CODE (type) == UNION_TYPE
6071       || TREE_CODE (type) == VECTOR_TYPE
6072       || (!SCALAR_FLOAT_MODE_P (orig_mode)
6073           && GET_MODE_CLASS (orig_mode) != MODE_INT
6074           && !ALL_SCALAR_FIXED_POINT_MODE_P (orig_mode))
6075       || !host_integerp (TYPE_SIZE_UNIT (type), 1))
6076     {
6077       error ("invalid vector type for attribute %qE", name);
6078       return NULL_TREE;
6079     }
6080
6081   if (vecsize % tree_low_cst (TYPE_SIZE_UNIT (type), 1))
6082     {
6083       error ("vector size not an integral multiple of component size");
6084       return NULL;
6085     }
6086
6087   if (vecsize == 0)
6088     {
6089       error ("zero vector size");
6090       return NULL;
6091     }
6092
6093   /* Calculate how many units fit in the vector.  */
6094   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
6095   if (nunits & (nunits - 1))
6096     {
6097       error ("number of components of the vector not a power of two");
6098       return NULL_TREE;
6099     }
6100
6101   new_type = build_vector_type (type, nunits);
6102
6103   /* Build back pointers if needed.  */
6104   *node = reconstruct_complex_type (*node, new_type);
6105
6106   return NULL_TREE;
6107 }
6108
6109 /* Handle the "nonnull" attribute.  */
6110 static tree
6111 handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
6112                           tree args, int ARG_UNUSED (flags),
6113                           bool *no_add_attrs)
6114 {
6115   tree type = *node;
6116   unsigned HOST_WIDE_INT attr_arg_num;
6117
6118   /* If no arguments are specified, all pointer arguments should be
6119      non-null.  Verify a full prototype is given so that the arguments
6120      will have the correct types when we actually check them later.  */
6121   if (!args)
6122     {
6123       if (!TYPE_ARG_TYPES (type))
6124         {
6125           error ("nonnull attribute without arguments on a non-prototype");
6126           *no_add_attrs = true;
6127         }
6128       return NULL_TREE;
6129     }
6130
6131   /* Argument list specified.  Verify that each argument number references
6132      a pointer argument.  */
6133   for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
6134     {
6135       tree argument;
6136       unsigned HOST_WIDE_INT arg_num = 0, ck_num;
6137
6138       if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
6139         {
6140           error ("nonnull argument has invalid operand number (argument %lu)",
6141                  (unsigned long) attr_arg_num);
6142           *no_add_attrs = true;
6143           return NULL_TREE;
6144         }
6145
6146       argument = TYPE_ARG_TYPES (type);
6147       if (argument)
6148         {
6149           for (ck_num = 1; ; ck_num++)
6150             {
6151               if (!argument || ck_num == arg_num)
6152                 break;
6153               argument = TREE_CHAIN (argument);
6154             }
6155
6156           if (!argument
6157               || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
6158             {
6159               error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)",
6160                      (unsigned long) attr_arg_num, (unsigned long) arg_num);
6161               *no_add_attrs = true;
6162               return NULL_TREE;
6163             }
6164
6165           if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
6166             {
6167               error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)",
6168                    (unsigned long) attr_arg_num, (unsigned long) arg_num);
6169               *no_add_attrs = true;
6170               return NULL_TREE;
6171             }
6172         }
6173     }
6174
6175   return NULL_TREE;
6176 }
6177
6178 /* Check the argument list of a function call for null in argument slots
6179    that are marked as requiring a non-null pointer argument.  The NARGS
6180    arguments are passed in the array ARGARRAY.
6181 */
6182
6183 static void
6184 check_function_nonnull (tree attrs, int nargs, tree *argarray)
6185 {
6186   tree a, args;
6187   int i;
6188
6189   for (a = attrs; a; a = TREE_CHAIN (a))
6190     {
6191       if (is_attribute_p ("nonnull", TREE_PURPOSE (a)))
6192         {
6193           args = TREE_VALUE (a);
6194
6195           /* Walk the argument list.  If we encounter an argument number we
6196              should check for non-null, do it.  If the attribute has no args,
6197              then every pointer argument is checked (in which case the check
6198              for pointer type is done in check_nonnull_arg).  */
6199           for (i = 0; i < nargs; i++)
6200             {
6201               if (!args || nonnull_check_p (args, i + 1))
6202                 check_function_arguments_recurse (check_nonnull_arg, NULL,
6203                                                   argarray[i],
6204                                                   i + 1);
6205             }
6206         }
6207     }
6208 }
6209
6210 /* Check that the Nth argument of a function call (counting backwards
6211    from the end) is a (pointer)0.  The NARGS arguments are passed in the
6212    array ARGARRAY.  */
6213
6214 static void
6215 check_function_sentinel (tree attrs, int nargs, tree *argarray, tree typelist)
6216 {
6217   tree attr = lookup_attribute ("sentinel", attrs);
6218
6219   if (attr)
6220     {
6221       int len = 0;
6222       int pos = 0;
6223       tree sentinel;
6224
6225       /* Skip over the named arguments.  */
6226       while (typelist && len < nargs)
6227         {
6228           typelist = TREE_CHAIN (typelist);
6229           len++;
6230         }
6231
6232       if (TREE_VALUE (attr))
6233         {
6234           tree p = TREE_VALUE (TREE_VALUE (attr));
6235           pos = TREE_INT_CST_LOW (p);
6236         }
6237
6238       /* The sentinel must be one of the varargs, i.e.
6239          in position >= the number of fixed arguments.  */
6240       if ((nargs - 1 - pos) < len)
6241         {
6242           warning (OPT_Wformat,
6243                    "not enough variable arguments to fit a sentinel");
6244           return;
6245         }
6246
6247       /* Validate the sentinel.  */
6248       sentinel = argarray[nargs - 1 - pos];
6249       if ((!POINTER_TYPE_P (TREE_TYPE (sentinel))
6250            || !integer_zerop (sentinel))
6251           /* Although __null (in C++) is only an integer we allow it
6252              nevertheless, as we are guaranteed that it's exactly
6253              as wide as a pointer, and we don't want to force
6254              users to cast the NULL they have written there.
6255              We warn with -Wstrict-null-sentinel, though.  */
6256           && (warn_strict_null_sentinel || null_node != sentinel))
6257         warning (OPT_Wformat, "missing sentinel in function call");
6258     }
6259 }
6260
6261 /* Helper for check_function_nonnull; given a list of operands which
6262    must be non-null in ARGS, determine if operand PARAM_NUM should be
6263    checked.  */
6264
6265 static bool
6266 nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num)
6267 {
6268   unsigned HOST_WIDE_INT arg_num = 0;
6269
6270   for (; args; args = TREE_CHAIN (args))
6271     {
6272       bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num);
6273
6274       gcc_assert (found);
6275
6276       if (arg_num == param_num)
6277         return true;
6278     }
6279   return false;
6280 }
6281
6282 /* Check that the function argument PARAM (which is operand number
6283    PARAM_NUM) is non-null.  This is called by check_function_nonnull
6284    via check_function_arguments_recurse.  */
6285
6286 static void
6287 check_nonnull_arg (void * ARG_UNUSED (ctx), tree param,
6288                    unsigned HOST_WIDE_INT param_num)
6289 {
6290   /* Just skip checking the argument if it's not a pointer.  This can
6291      happen if the "nonnull" attribute was given without an operand
6292      list (which means to check every pointer argument).  */
6293
6294   if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE)
6295     return;
6296
6297   if (integer_zerop (param))
6298     warning (OPT_Wnonnull, "null argument where non-null required "
6299              "(argument %lu)", (unsigned long) param_num);
6300 }
6301
6302 /* Helper for nonnull attribute handling; fetch the operand number
6303    from the attribute argument list.  */
6304
6305 static bool
6306 get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp)
6307 {
6308   /* Verify the arg number is a constant.  */
6309   if (TREE_CODE (arg_num_expr) != INTEGER_CST
6310       || TREE_INT_CST_HIGH (arg_num_expr) != 0)
6311     return false;
6312
6313   *valp = TREE_INT_CST_LOW (arg_num_expr);
6314   return true;
6315 }
6316
6317 /* Handle a "nothrow" attribute; arguments as in
6318    struct attribute_spec.handler.  */
6319
6320 static tree
6321 handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6322                           int ARG_UNUSED (flags), bool *no_add_attrs)
6323 {
6324   if (TREE_CODE (*node) == FUNCTION_DECL)
6325     TREE_NOTHROW (*node) = 1;
6326   /* ??? TODO: Support types.  */
6327   else
6328     {
6329       warning (OPT_Wattributes, "%qE attribute ignored", name);
6330       *no_add_attrs = true;
6331     }
6332
6333   return NULL_TREE;
6334 }
6335
6336 /* Handle a "cleanup" attribute; arguments as in
6337    struct attribute_spec.handler.  */
6338
6339 static tree
6340 handle_cleanup_attribute (tree *node, tree name, tree args,
6341                           int ARG_UNUSED (flags), bool *no_add_attrs)
6342 {
6343   tree decl = *node;
6344   tree cleanup_id, cleanup_decl;
6345
6346   /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do
6347      for global destructors in C++.  This requires infrastructure that
6348      we don't have generically at the moment.  It's also not a feature
6349      we'd be missing too much, since we do have attribute constructor.  */
6350   if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl))
6351     {
6352       warning (OPT_Wattributes, "%qE attribute ignored", name);
6353       *no_add_attrs = true;
6354       return NULL_TREE;
6355     }
6356
6357   /* Verify that the argument is a function in scope.  */
6358   /* ??? We could support pointers to functions here as well, if
6359      that was considered desirable.  */
6360   cleanup_id = TREE_VALUE (args);
6361   if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE)
6362     {
6363       error ("cleanup argument not an identifier");
6364       *no_add_attrs = true;
6365       return NULL_TREE;
6366     }
6367   cleanup_decl = lookup_name (cleanup_id);
6368   if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL)
6369     {
6370       error ("cleanup argument not a function");
6371       *no_add_attrs = true;
6372       return NULL_TREE;
6373     }
6374
6375   /* That the function has proper type is checked with the
6376      eventual call to build_function_call.  */
6377
6378   return NULL_TREE;
6379 }
6380
6381 /* Handle a "warn_unused_result" attribute.  No special handling.  */
6382
6383 static tree
6384 handle_warn_unused_result_attribute (tree *node, tree name,
6385                                tree ARG_UNUSED (args),
6386                                int ARG_UNUSED (flags), bool *no_add_attrs)
6387 {
6388   /* Ignore the attribute for functions not returning any value.  */
6389   if (VOID_TYPE_P (TREE_TYPE (*node)))
6390     {
6391       warning (OPT_Wattributes, "%qE attribute ignored", name);
6392       *no_add_attrs = true;
6393     }
6394
6395   return NULL_TREE;
6396 }
6397
6398 /* Handle a "sentinel" attribute.  */
6399
6400 static tree
6401 handle_sentinel_attribute (tree *node, tree name, tree args,
6402                            int ARG_UNUSED (flags), bool *no_add_attrs)
6403 {
6404   tree params = TYPE_ARG_TYPES (*node);
6405
6406   if (!params)
6407     {
6408       warning (OPT_Wattributes,
6409                "%qE attribute requires prototypes with named arguments", name);
6410       *no_add_attrs = true;
6411     }
6412   else
6413     {
6414       while (TREE_CHAIN (params))
6415         params = TREE_CHAIN (params);
6416
6417       if (VOID_TYPE_P (TREE_VALUE (params)))
6418         {
6419           warning (OPT_Wattributes,
6420                    "%qE attribute only applies to variadic functions", name);
6421           *no_add_attrs = true;
6422         }
6423     }
6424
6425   if (args)
6426     {
6427       tree position = TREE_VALUE (args);
6428
6429       if (TREE_CODE (position) != INTEGER_CST)
6430         {
6431           warning (OPT_Wattributes,
6432                    "requested position is not an integer constant");
6433           *no_add_attrs = true;
6434         }
6435       else
6436         {
6437           if (tree_int_cst_lt (position, integer_zero_node))
6438             {
6439               warning (OPT_Wattributes,
6440                        "requested position is less than zero");
6441               *no_add_attrs = true;
6442             }
6443         }
6444     }
6445
6446   return NULL_TREE;
6447 }
6448
6449 /* Handle a "type_generic" attribute.  */
6450
6451 static tree
6452 handle_type_generic_attribute (tree *node, tree ARG_UNUSED (name),
6453                                tree ARG_UNUSED (args), int ARG_UNUSED (flags),
6454                                bool * ARG_UNUSED (no_add_attrs))
6455 {
6456   /* Ensure we have a function type, with no arguments.  */
6457   gcc_assert (TREE_CODE (*node) == FUNCTION_TYPE && ! TYPE_ARG_TYPES (*node));
6458
6459   return NULL_TREE;
6460 }
6461 \f
6462 /* Check for valid arguments being passed to a function.
6463    ATTRS is a list of attributes.  There are NARGS arguments in the array
6464    ARGARRAY.  TYPELIST is the list of argument types for the function.
6465  */
6466 void
6467 check_function_arguments (tree attrs, int nargs, tree *argarray, tree typelist)
6468 {
6469   /* Check for null being passed in a pointer argument that must be
6470      non-null.  We also need to do this if format checking is enabled.  */
6471
6472   if (warn_nonnull)
6473     check_function_nonnull (attrs, nargs, argarray);
6474
6475   /* Check for errors in format strings.  */
6476
6477   if (warn_format || warn_missing_format_attribute)
6478     check_function_format (attrs, nargs, argarray);
6479
6480   if (warn_format)
6481     check_function_sentinel (attrs, nargs, argarray, typelist);
6482 }
6483
6484 /* Generic argument checking recursion routine.  PARAM is the argument to
6485    be checked.  PARAM_NUM is the number of the argument.  CALLBACK is invoked
6486    once the argument is resolved.  CTX is context for the callback.  */
6487 void
6488 check_function_arguments_recurse (void (*callback)
6489                                   (void *, tree, unsigned HOST_WIDE_INT),
6490                                   void *ctx, tree param,
6491                                   unsigned HOST_WIDE_INT param_num)
6492 {
6493   if ((TREE_CODE (param) == NOP_EXPR || TREE_CODE (param) == CONVERT_EXPR)
6494       && (TYPE_PRECISION (TREE_TYPE (param))
6495           == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (param, 0)))))
6496     {
6497       /* Strip coercion.  */
6498       check_function_arguments_recurse (callback, ctx,
6499                                         TREE_OPERAND (param, 0), param_num);
6500       return;
6501     }
6502
6503   if (TREE_CODE (param) == CALL_EXPR)
6504     {
6505       tree type = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (param)));
6506       tree attrs;
6507       bool found_format_arg = false;
6508
6509       /* See if this is a call to a known internationalization function
6510          that modifies a format arg.  Such a function may have multiple
6511          format_arg attributes (for example, ngettext).  */
6512
6513       for (attrs = TYPE_ATTRIBUTES (type);
6514            attrs;
6515            attrs = TREE_CHAIN (attrs))
6516         if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs)))
6517           {
6518             tree inner_arg;
6519             tree format_num_expr;
6520             int format_num;
6521             int i;
6522             call_expr_arg_iterator iter;
6523
6524             /* Extract the argument number, which was previously checked
6525                to be valid.  */
6526             format_num_expr = TREE_VALUE (TREE_VALUE (attrs));
6527
6528             gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST
6529                         && !TREE_INT_CST_HIGH (format_num_expr));
6530
6531             format_num = TREE_INT_CST_LOW (format_num_expr);
6532
6533             for (inner_arg = first_call_expr_arg (param, &iter), i = 1;
6534                  inner_arg != 0;
6535                  inner_arg = next_call_expr_arg (&iter), i++)
6536               if (i == format_num)
6537                 {
6538                   check_function_arguments_recurse (callback, ctx,
6539                                                     inner_arg, param_num);
6540                   found_format_arg = true;
6541                   break;
6542                 }
6543           }
6544
6545       /* If we found a format_arg attribute and did a recursive check,
6546          we are done with checking this argument.  Otherwise, we continue
6547          and this will be considered a non-literal.  */
6548       if (found_format_arg)
6549         return;
6550     }
6551
6552   if (TREE_CODE (param) == COND_EXPR)
6553     {
6554       /* Check both halves of the conditional expression.  */
6555       check_function_arguments_recurse (callback, ctx,
6556                                         TREE_OPERAND (param, 1), param_num);
6557       check_function_arguments_recurse (callback, ctx,
6558                                         TREE_OPERAND (param, 2), param_num);
6559       return;
6560     }
6561
6562   (*callback) (ctx, param, param_num);
6563 }
6564
6565 /* Function to help qsort sort FIELD_DECLs by name order.  */
6566
6567 int
6568 field_decl_cmp (const void *x_p, const void *y_p)
6569 {
6570   const tree *const x = (const tree *const) x_p;
6571   const tree *const y = (const tree *const) y_p;
6572
6573   if (DECL_NAME (*x) == DECL_NAME (*y))
6574     /* A nontype is "greater" than a type.  */
6575     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
6576   if (DECL_NAME (*x) == NULL_TREE)
6577     return -1;
6578   if (DECL_NAME (*y) == NULL_TREE)
6579     return 1;
6580   if (DECL_NAME (*x) < DECL_NAME (*y))
6581     return -1;
6582   return 1;
6583 }
6584
6585 static struct {
6586   gt_pointer_operator new_value;
6587   void *cookie;
6588 } resort_data;
6589
6590 /* This routine compares two fields like field_decl_cmp but using the
6591 pointer operator in resort_data.  */
6592
6593 static int
6594 resort_field_decl_cmp (const void *x_p, const void *y_p)
6595 {
6596   const tree *const x = (const tree *const) x_p;
6597   const tree *const y = (const tree *const) y_p;
6598
6599   if (DECL_NAME (*x) == DECL_NAME (*y))
6600     /* A nontype is "greater" than a type.  */
6601     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
6602   if (DECL_NAME (*x) == NULL_TREE)
6603     return -1;
6604   if (DECL_NAME (*y) == NULL_TREE)
6605     return 1;
6606   {
6607     tree d1 = DECL_NAME (*x);
6608     tree d2 = DECL_NAME (*y);
6609     resort_data.new_value (&d1, resort_data.cookie);
6610     resort_data.new_value (&d2, resort_data.cookie);
6611     if (d1 < d2)
6612       return -1;
6613   }
6614   return 1;
6615 }
6616
6617 /* Resort DECL_SORTED_FIELDS because pointers have been reordered.  */
6618
6619 void
6620 resort_sorted_fields (void *obj,
6621                       void * ARG_UNUSED (orig_obj),
6622                       gt_pointer_operator new_value,
6623                       void *cookie)
6624 {
6625   struct sorted_fields_type *sf = (struct sorted_fields_type *) obj;
6626   resort_data.new_value = new_value;
6627   resort_data.cookie = cookie;
6628   qsort (&sf->elts[0], sf->len, sizeof (tree),
6629          resort_field_decl_cmp);
6630 }
6631
6632 /* Subroutine of c_parse_error.
6633    Return the result of concatenating LHS and RHS. RHS is really
6634    a string literal, its first character is indicated by RHS_START and
6635    RHS_SIZE is its length (including the terminating NUL character).
6636
6637    The caller is responsible for deleting the returned pointer.  */
6638
6639 static char *
6640 catenate_strings (const char *lhs, const char *rhs_start, int rhs_size)
6641 {
6642   const int lhs_size = strlen (lhs);
6643   char *result = XNEWVEC (char, lhs_size + rhs_size);
6644   strncpy (result, lhs, lhs_size);
6645   strncpy (result + lhs_size, rhs_start, rhs_size);
6646   return result;
6647 }
6648
6649 /* Issue the error given by GMSGID, indicating that it occurred before
6650    TOKEN, which had the associated VALUE.  */
6651
6652 void
6653 c_parse_error (const char *gmsgid, enum cpp_ttype token, tree value)
6654 {
6655 #define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2))
6656
6657   char *message = NULL;
6658
6659   if (token == CPP_EOF)
6660     message = catenate_messages (gmsgid, " at end of input");
6661   else if (token == CPP_CHAR || token == CPP_WCHAR)
6662     {
6663       unsigned int val = TREE_INT_CST_LOW (value);
6664       const char *const ell = (token == CPP_CHAR) ? "" : "L";
6665       if (val <= UCHAR_MAX && ISGRAPH (val))
6666         message = catenate_messages (gmsgid, " before %s'%c'");
6667       else
6668         message = catenate_messages (gmsgid, " before %s'\\x%x'");
6669
6670       error (message, ell, val);
6671       free (message);
6672       message = NULL;
6673     }
6674   else if (token == CPP_STRING || token == CPP_WSTRING)
6675     message = catenate_messages (gmsgid, " before string constant");
6676   else if (token == CPP_NUMBER)
6677     message = catenate_messages (gmsgid, " before numeric constant");
6678   else if (token == CPP_NAME)
6679     {
6680       message = catenate_messages (gmsgid, " before %qE");
6681       error (message, value);
6682       free (message);
6683       message = NULL;
6684     }
6685   else if (token == CPP_PRAGMA)
6686     message = catenate_messages (gmsgid, " before %<#pragma%>");
6687   else if (token == CPP_PRAGMA_EOL)
6688     message = catenate_messages (gmsgid, " before end of line");
6689   else if (token < N_TTYPES)
6690     {
6691       message = catenate_messages (gmsgid, " before %qs token");
6692       error (message, cpp_type2name (token));
6693       free (message);
6694       message = NULL;
6695     }
6696   else
6697     error (gmsgid);
6698
6699   if (message)
6700     {
6701       error (message);
6702       free (message);
6703     }
6704 #undef catenate_messages
6705 }
6706
6707 /* Walk a gimplified function and warn for functions whose return value is
6708    ignored and attribute((warn_unused_result)) is set.  This is done before
6709    inlining, so we don't have to worry about that.  */
6710
6711 void
6712 c_warn_unused_result (tree *top_p)
6713 {
6714   tree t = *top_p;
6715   tree_stmt_iterator i;
6716   tree fdecl, ftype;
6717
6718   switch (TREE_CODE (t))
6719     {
6720     case STATEMENT_LIST:
6721       for (i = tsi_start (*top_p); !tsi_end_p (i); tsi_next (&i))
6722         c_warn_unused_result (tsi_stmt_ptr (i));
6723       break;
6724
6725     case COND_EXPR:
6726       c_warn_unused_result (&COND_EXPR_THEN (t));
6727       c_warn_unused_result (&COND_EXPR_ELSE (t));
6728       break;
6729     case BIND_EXPR:
6730       c_warn_unused_result (&BIND_EXPR_BODY (t));
6731       break;
6732     case TRY_FINALLY_EXPR:
6733     case TRY_CATCH_EXPR:
6734       c_warn_unused_result (&TREE_OPERAND (t, 0));
6735       c_warn_unused_result (&TREE_OPERAND (t, 1));
6736       break;
6737     case CATCH_EXPR:
6738       c_warn_unused_result (&CATCH_BODY (t));
6739       break;
6740     case EH_FILTER_EXPR:
6741       c_warn_unused_result (&EH_FILTER_FAILURE (t));
6742       break;
6743
6744     case CALL_EXPR:
6745       if (TREE_USED (t))
6746         break;
6747
6748       /* This is a naked call, as opposed to a CALL_EXPR nested inside
6749          a MODIFY_EXPR.  All calls whose value is ignored should be
6750          represented like this.  Look for the attribute.  */
6751       fdecl = get_callee_fndecl (t);
6752       if (fdecl)
6753         ftype = TREE_TYPE (fdecl);
6754       else
6755         {
6756           ftype = TREE_TYPE (CALL_EXPR_FN (t));
6757           /* Look past pointer-to-function to the function type itself.  */
6758           ftype = TREE_TYPE (ftype);
6759         }
6760
6761       if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype)))
6762         {
6763           if (fdecl)
6764             warning (0, "%Hignoring return value of %qD, "
6765                      "declared with attribute warn_unused_result",
6766                      EXPR_LOCUS (t), fdecl);
6767           else
6768             warning (0, "%Hignoring return value of function "
6769                      "declared with attribute warn_unused_result",
6770                      EXPR_LOCUS (t));
6771         }
6772       break;
6773
6774     default:
6775       /* Not a container, not a call, or a call whose value is used.  */
6776       break;
6777     }
6778 }
6779
6780 /* Convert a character from the host to the target execution character
6781    set.  cpplib handles this, mostly.  */
6782
6783 HOST_WIDE_INT
6784 c_common_to_target_charset (HOST_WIDE_INT c)
6785 {
6786   /* Character constants in GCC proper are sign-extended under -fsigned-char,
6787      zero-extended under -fno-signed-char.  cpplib insists that characters
6788      and character constants are always unsigned.  Hence we must convert
6789      back and forth.  */
6790   cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1);
6791
6792   uc = cpp_host_to_exec_charset (parse_in, uc);
6793
6794   if (flag_signed_char)
6795     return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE)
6796                                >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE);
6797   else
6798     return uc;
6799 }
6800
6801 /* Build the result of __builtin_offsetof.  EXPR is a nested sequence of
6802    component references, with STOP_REF, or alternatively an INDIRECT_REF of
6803    NULL, at the bottom; much like the traditional rendering of offsetof as a
6804    macro.  Returns the folded and properly cast result.  */
6805
6806 static tree
6807 fold_offsetof_1 (tree expr, tree stop_ref)
6808 {
6809   enum tree_code code = PLUS_EXPR;
6810   tree base, off, t;
6811
6812   if (expr == stop_ref && TREE_CODE (expr) != ERROR_MARK)
6813     return size_zero_node;
6814
6815   switch (TREE_CODE (expr))
6816     {
6817     case ERROR_MARK:
6818       return expr;
6819
6820     case VAR_DECL:
6821       error ("cannot apply %<offsetof%> to static data member %qD", expr);
6822       return error_mark_node;
6823
6824     case CALL_EXPR:
6825       error ("cannot apply %<offsetof%> when %<operator[]%> is overloaded");
6826       return error_mark_node;
6827
6828     case INTEGER_CST:
6829       gcc_assert (integer_zerop (expr));
6830       return size_zero_node;
6831
6832     case NOP_EXPR:
6833     case INDIRECT_REF:
6834       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
6835       gcc_assert (base == error_mark_node || base == size_zero_node);
6836       return base;
6837
6838     case COMPONENT_REF:
6839       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
6840       if (base == error_mark_node)
6841         return base;
6842
6843       t = TREE_OPERAND (expr, 1);
6844       if (DECL_C_BIT_FIELD (t))
6845         {
6846           error ("attempt to take address of bit-field structure "
6847                  "member %qD", t);
6848           return error_mark_node;
6849         }
6850       off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t),
6851                         size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t), 1)
6852                                   / BITS_PER_UNIT));
6853       break;
6854
6855     case ARRAY_REF:
6856       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
6857       if (base == error_mark_node)
6858         return base;
6859
6860       t = TREE_OPERAND (expr, 1);
6861       if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0)
6862         {
6863           code = MINUS_EXPR;
6864           t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t);
6865         }
6866       t = convert (sizetype, t);
6867       off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
6868       break;
6869
6870     case COMPOUND_EXPR:
6871       /* Handle static members of volatile structs.  */
6872       t = TREE_OPERAND (expr, 1);
6873       gcc_assert (TREE_CODE (t) == VAR_DECL);
6874       return fold_offsetof_1 (t, stop_ref);
6875
6876     default:
6877       gcc_unreachable ();
6878     }
6879
6880   return size_binop (code, base, off);
6881 }
6882
6883 tree
6884 fold_offsetof (tree expr, tree stop_ref)
6885 {
6886   /* Convert back from the internal sizetype to size_t.  */
6887   return convert (size_type_node, fold_offsetof_1 (expr, stop_ref));
6888 }
6889
6890 /* Print an error message for an invalid lvalue.  USE says
6891    how the lvalue is being used and so selects the error message.  */
6892
6893 void
6894 lvalue_error (enum lvalue_use use)
6895 {
6896   switch (use)
6897     {
6898     case lv_assign:
6899       error ("lvalue required as left operand of assignment");
6900       break;
6901     case lv_increment:
6902       error ("lvalue required as increment operand");
6903       break;
6904     case lv_decrement:
6905       error ("lvalue required as decrement operand");
6906       break;
6907     case lv_addressof:
6908       error ("lvalue required as unary %<&%> operand");
6909       break;
6910     case lv_asm:
6911       error ("lvalue required in asm statement");
6912       break;
6913     default:
6914       gcc_unreachable ();
6915     }
6916 }
6917 \f
6918 /* *PTYPE is an incomplete array.  Complete it with a domain based on
6919    INITIAL_VALUE.  If INITIAL_VALUE is not present, use 1 if DO_DEFAULT
6920    is true.  Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered,
6921    2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty.  */
6922
6923 int
6924 complete_array_type (tree *ptype, tree initial_value, bool do_default)
6925 {
6926   tree maxindex, type, main_type, elt, unqual_elt;
6927   int failure = 0, quals;
6928   hashval_t hashcode = 0;
6929
6930   maxindex = size_zero_node;
6931   if (initial_value)
6932     {
6933       if (TREE_CODE (initial_value) == STRING_CST)
6934         {
6935           int eltsize
6936             = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value)));
6937           maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1);
6938         }
6939       else if (TREE_CODE (initial_value) == CONSTRUCTOR)
6940         {
6941           VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (initial_value);
6942
6943           if (VEC_empty (constructor_elt, v))
6944             {
6945               if (pedantic)
6946                 failure = 3;
6947               maxindex = integer_minus_one_node;
6948             }
6949           else
6950             {
6951               tree curindex;
6952               unsigned HOST_WIDE_INT cnt;
6953               constructor_elt *ce;
6954
6955               if (VEC_index (constructor_elt, v, 0)->index)
6956                 maxindex = fold_convert (sizetype,
6957                                          VEC_index (constructor_elt,
6958                                                     v, 0)->index);
6959               curindex = maxindex;
6960
6961               for (cnt = 1;
6962                    VEC_iterate (constructor_elt, v, cnt, ce);
6963                    cnt++)
6964                 {
6965                   if (ce->index)
6966                     curindex = fold_convert (sizetype, ce->index);
6967                   else
6968                     curindex = size_binop (PLUS_EXPR, curindex, size_one_node);
6969
6970                   if (tree_int_cst_lt (maxindex, curindex))
6971                     maxindex = curindex;
6972                 }
6973             }
6974         }
6975       else
6976         {
6977           /* Make an error message unless that happened already.  */
6978           if (initial_value != error_mark_node)
6979             failure = 1;
6980         }
6981     }
6982   else
6983     {
6984       failure = 2;
6985       if (!do_default)
6986         return failure;
6987     }
6988
6989   type = *ptype;
6990   elt = TREE_TYPE (type);
6991   quals = TYPE_QUALS (strip_array_types (elt));
6992   if (quals == 0)
6993     unqual_elt = elt;
6994   else
6995     unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
6996
6997   /* Using build_distinct_type_copy and modifying things afterward instead
6998      of using build_array_type to create a new type preserves all of the
6999      TYPE_LANG_FLAG_? bits that the front end may have set.  */
7000   main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
7001   TREE_TYPE (main_type) = unqual_elt;
7002   TYPE_DOMAIN (main_type) = build_index_type (maxindex);
7003   layout_type (main_type);
7004
7005   /* Make sure we have the canonical MAIN_TYPE. */
7006   hashcode = iterative_hash_object (TYPE_HASH (unqual_elt), hashcode);
7007   hashcode = iterative_hash_object (TYPE_HASH (TYPE_DOMAIN (main_type)),
7008                                     hashcode);
7009   main_type = type_hash_canon (hashcode, main_type);
7010
7011   if (quals == 0)
7012     type = main_type;
7013   else
7014     type = c_build_qualified_type (main_type, quals);
7015
7016   *ptype = type;
7017   return failure;
7018 }
7019
7020 \f
7021 /* Used to help initialize the builtin-types.def table.  When a type of
7022    the correct size doesn't exist, use error_mark_node instead of NULL.
7023    The later results in segfaults even when a decl using the type doesn't
7024    get invoked.  */
7025
7026 tree
7027 builtin_type_for_size (int size, bool unsignedp)
7028 {
7029   tree type = lang_hooks.types.type_for_size (size, unsignedp);
7030   return type ? type : error_mark_node;
7031 }
7032
7033 /* A helper function for resolve_overloaded_builtin in resolving the
7034    overloaded __sync_ builtins.  Returns a positive power of 2 if the
7035    first operand of PARAMS is a pointer to a supported data type.
7036    Returns 0 if an error is encountered.  */
7037
7038 static int
7039 sync_resolve_size (tree function, tree params)
7040 {
7041   tree type;
7042   int size;
7043
7044   if (params == NULL)
7045     {
7046       error ("too few arguments to function %qE", function);
7047       return 0;
7048     }
7049
7050   type = TREE_TYPE (TREE_VALUE (params));
7051   if (TREE_CODE (type) != POINTER_TYPE)
7052     goto incompatible;
7053
7054   type = TREE_TYPE (type);
7055   if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
7056     goto incompatible;
7057
7058   size = tree_low_cst (TYPE_SIZE_UNIT (type), 1);
7059   if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16)
7060     return size;
7061
7062  incompatible:
7063   error ("incompatible type for argument %d of %qE", 1, function);
7064   return 0;
7065 }
7066
7067 /* A helper function for resolve_overloaded_builtin.  Adds casts to
7068    PARAMS to make arguments match up with those of FUNCTION.  Drops
7069    the variadic arguments at the end.  Returns false if some error
7070    was encountered; true on success.  */
7071
7072 static bool
7073 sync_resolve_params (tree orig_function, tree function, tree params)
7074 {
7075   tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (function));
7076   tree ptype;
7077   int number;
7078
7079   /* We've declared the implementation functions to use "volatile void *"
7080      as the pointer parameter, so we shouldn't get any complaints from the
7081      call to check_function_arguments what ever type the user used.  */
7082   arg_types = TREE_CHAIN (arg_types);
7083   ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params)));
7084   number = 2;
7085
7086   /* For the rest of the values, we need to cast these to FTYPE, so that we
7087      don't get warnings for passing pointer types, etc.  */
7088   while (arg_types != void_list_node)
7089     {
7090       tree val;
7091
7092       params = TREE_CHAIN (params);
7093       if (params == NULL)
7094         {
7095           error ("too few arguments to function %qE", orig_function);
7096           return false;
7097         }
7098
7099       /* ??? Ideally for the first conversion we'd use convert_for_assignment
7100          so that we get warnings for anything that doesn't match the pointer
7101          type.  This isn't portable across the C and C++ front ends atm.  */
7102       val = TREE_VALUE (params);
7103       val = convert (ptype, val);
7104       val = convert (TREE_VALUE (arg_types), val);
7105       TREE_VALUE (params) = val;
7106
7107       arg_types = TREE_CHAIN (arg_types);
7108       number++;
7109     }
7110
7111   /* The definition of these primitives is variadic, with the remaining
7112      being "an optional list of variables protected by the memory barrier".
7113      No clue what that's supposed to mean, precisely, but we consider all
7114      call-clobbered variables to be protected so we're safe.  */
7115   TREE_CHAIN (params) = NULL;
7116
7117   return true;
7118 }
7119
7120 /* A helper function for resolve_overloaded_builtin.  Adds a cast to
7121    RESULT to make it match the type of the first pointer argument in
7122    PARAMS.  */
7123
7124 static tree
7125 sync_resolve_return (tree params, tree result)
7126 {
7127   tree ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params)));
7128   ptype = TYPE_MAIN_VARIANT (ptype);
7129   return convert (ptype, result);
7130 }
7131
7132 /* Some builtin functions are placeholders for other expressions.  This
7133    function should be called immediately after parsing the call expression
7134    before surrounding code has committed to the type of the expression.
7135
7136    FUNCTION is the DECL that has been invoked; it is known to be a builtin.
7137    PARAMS is the argument list for the call.  The return value is non-null
7138    when expansion is complete, and null if normal processing should
7139    continue.  */
7140
7141 tree
7142 resolve_overloaded_builtin (tree function, tree params)
7143 {
7144   enum built_in_function orig_code = DECL_FUNCTION_CODE (function);
7145   switch (DECL_BUILT_IN_CLASS (function))
7146     {
7147     case BUILT_IN_NORMAL:
7148       break;
7149     case BUILT_IN_MD:
7150       if (targetm.resolve_overloaded_builtin)
7151         return targetm.resolve_overloaded_builtin (function, params);
7152       else
7153         return NULL_TREE;
7154     default:
7155       return NULL_TREE;
7156     }
7157
7158   /* Handle BUILT_IN_NORMAL here.  */
7159   switch (orig_code)
7160     {
7161     case BUILT_IN_FETCH_AND_ADD_N:
7162     case BUILT_IN_FETCH_AND_SUB_N:
7163     case BUILT_IN_FETCH_AND_OR_N:
7164     case BUILT_IN_FETCH_AND_AND_N:
7165     case BUILT_IN_FETCH_AND_XOR_N:
7166     case BUILT_IN_FETCH_AND_NAND_N:
7167     case BUILT_IN_ADD_AND_FETCH_N:
7168     case BUILT_IN_SUB_AND_FETCH_N:
7169     case BUILT_IN_OR_AND_FETCH_N:
7170     case BUILT_IN_AND_AND_FETCH_N:
7171     case BUILT_IN_XOR_AND_FETCH_N:
7172     case BUILT_IN_NAND_AND_FETCH_N:
7173     case BUILT_IN_BOOL_COMPARE_AND_SWAP_N:
7174     case BUILT_IN_VAL_COMPARE_AND_SWAP_N:
7175     case BUILT_IN_LOCK_TEST_AND_SET_N:
7176     case BUILT_IN_LOCK_RELEASE_N:
7177       {
7178         int n = sync_resolve_size (function, params);
7179         tree new_function, result;
7180
7181         if (n == 0)
7182           return error_mark_node;
7183
7184         new_function = built_in_decls[orig_code + exact_log2 (n) + 1];
7185         if (!sync_resolve_params (function, new_function, params))
7186           return error_mark_node;
7187
7188         result = build_function_call (new_function, params);
7189         if (orig_code != BUILT_IN_BOOL_COMPARE_AND_SWAP_N
7190             && orig_code != BUILT_IN_LOCK_RELEASE_N)
7191           result = sync_resolve_return (params, result);
7192
7193         return result;
7194       }
7195
7196     default:
7197       return NULL_TREE;
7198     }
7199 }
7200
7201 /* Ignoring their sign, return true if two scalar types are the same.  */
7202 bool
7203 same_scalar_type_ignoring_signedness (tree t1, tree t2)
7204 {
7205   enum tree_code c1 = TREE_CODE (t1), c2 = TREE_CODE (t2);
7206
7207   gcc_assert ((c1 == INTEGER_TYPE || c1 == REAL_TYPE || c1 == FIXED_POINT_TYPE)
7208               && (c2 == INTEGER_TYPE || c2 == REAL_TYPE
7209                   || c2 == FIXED_POINT_TYPE));
7210
7211   /* Equality works here because c_common_signed_type uses
7212      TYPE_MAIN_VARIANT.  */
7213   return c_common_signed_type (t1)
7214     == c_common_signed_type (t2);
7215 }
7216
7217 /* Check for missing format attributes on function pointers.  LTYPE is
7218    the new type or left-hand side type.  RTYPE is the old type or
7219    right-hand side type.  Returns TRUE if LTYPE is missing the desired
7220    attribute.  */
7221
7222 bool
7223 check_missing_format_attribute (tree ltype, tree rtype)
7224 {
7225   tree const ttr = TREE_TYPE (rtype), ttl = TREE_TYPE (ltype);
7226   tree ra;
7227
7228   for (ra = TYPE_ATTRIBUTES (ttr); ra; ra = TREE_CHAIN (ra))
7229     if (is_attribute_p ("format", TREE_PURPOSE (ra)))
7230       break;
7231   if (ra)
7232     {
7233       tree la;
7234       for (la = TYPE_ATTRIBUTES (ttl); la; la = TREE_CHAIN (la))
7235         if (is_attribute_p ("format", TREE_PURPOSE (la)))
7236           break;
7237       return !la;
7238     }
7239   else
7240     return false;
7241 }
7242
7243 /* Subscripting with type char is likely to lose on a machine where
7244    chars are signed.  So warn on any machine, but optionally.  Don't
7245    warn for unsigned char since that type is safe.  Don't warn for
7246    signed char because anyone who uses that must have done so
7247    deliberately. Furthermore, we reduce the false positive load by
7248    warning only for non-constant value of type char.  */
7249
7250 void
7251 warn_array_subscript_with_type_char (tree index)
7252 {
7253   if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node
7254       && TREE_CODE (index) != INTEGER_CST)
7255     warning (OPT_Wchar_subscripts, "array subscript has type %<char%>");
7256 }
7257
7258 /* Implement -Wparentheses for the unexpected C precedence rules, to
7259    cover cases like x + y << z which readers are likely to
7260    misinterpret.  We have seen an expression in which CODE is a binary
7261    operator used to combine expressions headed by CODE_LEFT and
7262    CODE_RIGHT.  CODE_LEFT and CODE_RIGHT may be ERROR_MARK, which
7263    means that that side of the expression was not formed using a
7264    binary operator, or it was enclosed in parentheses.  */
7265
7266 void
7267 warn_about_parentheses (enum tree_code code, enum tree_code code_left,
7268                         enum tree_code code_right)
7269 {
7270   if (!warn_parentheses)
7271     return;
7272
7273   if (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
7274     {
7275       if (code_left == PLUS_EXPR || code_left == MINUS_EXPR
7276           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7277         warning (OPT_Wparentheses,
7278                  "suggest parentheses around + or - inside shift");
7279     }
7280
7281   if (code == TRUTH_ORIF_EXPR)
7282     {
7283       if (code_left == TRUTH_ANDIF_EXPR
7284           || code_right == TRUTH_ANDIF_EXPR)
7285         warning (OPT_Wparentheses,
7286                  "suggest parentheses around && within ||");
7287     }
7288
7289   if (code == BIT_IOR_EXPR)
7290     {
7291       if (code_left == BIT_AND_EXPR || code_left == BIT_XOR_EXPR
7292           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
7293           || code_right == BIT_AND_EXPR || code_right == BIT_XOR_EXPR
7294           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7295         warning (OPT_Wparentheses,
7296                  "suggest parentheses around arithmetic in operand of |");
7297       /* Check cases like x|y==z */
7298       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7299           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7300         warning (OPT_Wparentheses,
7301                  "suggest parentheses around comparison in operand of |");
7302     }
7303
7304   if (code == BIT_XOR_EXPR)
7305     {
7306       if (code_left == BIT_AND_EXPR
7307           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
7308           || code_right == BIT_AND_EXPR
7309           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7310         warning (OPT_Wparentheses,
7311                  "suggest parentheses around arithmetic in operand of ^");
7312       /* Check cases like x^y==z */
7313       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7314           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7315         warning (OPT_Wparentheses,
7316                  "suggest parentheses around comparison in operand of ^");
7317     }
7318
7319   if (code == BIT_AND_EXPR)
7320     {
7321       if (code_left == PLUS_EXPR || code_left == MINUS_EXPR
7322           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7323         warning (OPT_Wparentheses,
7324                  "suggest parentheses around + or - in operand of &");
7325       /* Check cases like x&y==z */
7326       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7327           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7328         warning (OPT_Wparentheses,
7329                  "suggest parentheses around comparison in operand of &");
7330     }
7331
7332   if (code == EQ_EXPR || code == NE_EXPR)
7333     {
7334       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7335           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7336         warning (OPT_Wparentheses,
7337                  "suggest parentheses around comparison in operand of %s",
7338                  code == EQ_EXPR ? "==" : "!=");
7339     }
7340   else if (TREE_CODE_CLASS (code) == tcc_comparison)
7341     {
7342       if ((TREE_CODE_CLASS (code_left) == tcc_comparison
7343            && code_left != NE_EXPR && code_left != EQ_EXPR)
7344           || (TREE_CODE_CLASS (code_right) == tcc_comparison
7345               && code_right != NE_EXPR && code_right != EQ_EXPR))
7346         warning (OPT_Wparentheses, "comparisons like X<=Y<=Z do not "
7347                  "have their mathematical meaning");
7348     }
7349 }
7350
7351 /* If LABEL (a LABEL_DECL) has not been used, issue a warning.  */
7352
7353 void
7354 warn_for_unused_label (tree label)
7355 {
7356   if (!TREE_USED (label))
7357     {
7358       if (DECL_INITIAL (label))
7359         warning (OPT_Wunused_label, "label %q+D defined but not used", label);
7360       else
7361         warning (OPT_Wunused_label, "label %q+D declared but not defined", label);
7362     }
7363 }
7364
7365 #ifndef TARGET_HAS_TARGETCM
7366 struct gcc_targetcm targetcm = TARGETCM_INITIALIZER;
7367 #endif
7368
7369 /* Warn for division by zero according to the value of DIVISOR.  */
7370
7371 void
7372 warn_for_div_by_zero (tree divisor)
7373 {
7374   /* If DIVISOR is zero, and has integral or fixed-point type, issue a warning
7375      about division by zero.  Do not issue a warning if DIVISOR has a
7376      floating-point type, since we consider 0.0/0.0 a valid way of
7377      generating a NaN.  */
7378   if (skip_evaluation == 0
7379       && (integer_zerop (divisor) || fixed_zerop (divisor)))
7380     warning (OPT_Wdiv_by_zero, "division by zero");
7381 }
7382
7383 #include "gt-c-common.h"