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 const_tree
4168 const_strip_array_types (const_tree type)
4169 {
4170   while (TREE_CODE (type) == ARRAY_TYPE)
4171     type = TREE_TYPE (type);
4172
4173   return type;
4174 }
4175
4176 /* Recursively remove any '*' or '&' operator from TYPE.  */
4177 tree
4178 strip_pointer_operator (tree t)
4179 {
4180   while (POINTER_TYPE_P (t))
4181     t = TREE_TYPE (t);
4182   return t;
4183 }
4184
4185 /* Recursively remove pointer or array type from TYPE. */
4186 tree
4187 strip_pointer_or_array_types (tree t)
4188 {
4189   while (TREE_CODE (t) == ARRAY_TYPE || POINTER_TYPE_P (t))
4190     t = TREE_TYPE (t);
4191   return t;
4192 }
4193
4194 /* Used to compare case labels.  K1 and K2 are actually tree nodes
4195    representing case labels, or NULL_TREE for a `default' label.
4196    Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
4197    K2, and 0 if K1 and K2 are equal.  */
4198
4199 int
4200 case_compare (splay_tree_key k1, splay_tree_key k2)
4201 {
4202   /* Consider a NULL key (such as arises with a `default' label) to be
4203      smaller than anything else.  */
4204   if (!k1)
4205     return k2 ? -1 : 0;
4206   else if (!k2)
4207     return k1 ? 1 : 0;
4208
4209   return tree_int_cst_compare ((tree) k1, (tree) k2);
4210 }
4211
4212 /* Process a case label for the range LOW_VALUE ... HIGH_VALUE.  If
4213    LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is
4214    actually a `default' label.  If only HIGH_VALUE is NULL_TREE, then
4215    case label was declared using the usual C/C++ syntax, rather than
4216    the GNU case range extension.  CASES is a tree containing all the
4217    case ranges processed so far; COND is the condition for the
4218    switch-statement itself.  Returns the CASE_LABEL_EXPR created, or
4219    ERROR_MARK_NODE if no CASE_LABEL_EXPR is created.  */
4220
4221 tree
4222 c_add_case_label (splay_tree cases, tree cond, tree orig_type,
4223                   tree low_value, tree high_value)
4224 {
4225   tree type;
4226   tree label;
4227   tree case_label;
4228   splay_tree_node node;
4229
4230   /* Create the LABEL_DECL itself.  */
4231   label = create_artificial_label ();
4232
4233   /* If there was an error processing the switch condition, bail now
4234      before we get more confused.  */
4235   if (!cond || cond == error_mark_node)
4236     goto error_out;
4237
4238   if ((low_value && TREE_TYPE (low_value)
4239        && POINTER_TYPE_P (TREE_TYPE (low_value)))
4240       || (high_value && TREE_TYPE (high_value)
4241           && POINTER_TYPE_P (TREE_TYPE (high_value))))
4242     {
4243       error ("pointers are not permitted as case values");
4244       goto error_out;
4245     }
4246
4247   /* Case ranges are a GNU extension.  */
4248   if (high_value && pedantic)
4249     pedwarn ("range expressions in switch statements are non-standard");
4250
4251   type = TREE_TYPE (cond);
4252   if (low_value)
4253     {
4254       low_value = check_case_value (low_value);
4255       low_value = convert_and_check (type, low_value);
4256       if (low_value == error_mark_node)
4257         goto error_out;
4258     }
4259   if (high_value)
4260     {
4261       high_value = check_case_value (high_value);
4262       high_value = convert_and_check (type, high_value);
4263       if (high_value == error_mark_node)
4264         goto error_out;
4265     }
4266
4267   if (low_value && high_value)
4268     {
4269       /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
4270          really a case range, even though it was written that way.
4271          Remove the HIGH_VALUE to simplify later processing.  */
4272       if (tree_int_cst_equal (low_value, high_value))
4273         high_value = NULL_TREE;
4274       else if (!tree_int_cst_lt (low_value, high_value))
4275         warning (0, "empty range specified");
4276     }
4277
4278   /* See if the case is in range of the type of the original testing
4279      expression.  If both low_value and high_value are out of range,
4280      don't insert the case label and return NULL_TREE.  */
4281   if (low_value
4282       && !check_case_bounds (type, orig_type,
4283                              &low_value, high_value ? &high_value : NULL))
4284     return NULL_TREE;
4285
4286   /* Look up the LOW_VALUE in the table of case labels we already
4287      have.  */
4288   node = splay_tree_lookup (cases, (splay_tree_key) low_value);
4289   /* If there was not an exact match, check for overlapping ranges.
4290      There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
4291      that's a `default' label and the only overlap is an exact match.  */
4292   if (!node && (low_value || high_value))
4293     {
4294       splay_tree_node low_bound;
4295       splay_tree_node high_bound;
4296
4297       /* Even though there wasn't an exact match, there might be an
4298          overlap between this case range and another case range.
4299          Since we've (inductively) not allowed any overlapping case
4300          ranges, we simply need to find the greatest low case label
4301          that is smaller that LOW_VALUE, and the smallest low case
4302          label that is greater than LOW_VALUE.  If there is an overlap
4303          it will occur in one of these two ranges.  */
4304       low_bound = splay_tree_predecessor (cases,
4305                                           (splay_tree_key) low_value);
4306       high_bound = splay_tree_successor (cases,
4307                                          (splay_tree_key) low_value);
4308
4309       /* Check to see if the LOW_BOUND overlaps.  It is smaller than
4310          the LOW_VALUE, so there is no need to check unless the
4311          LOW_BOUND is in fact itself a case range.  */
4312       if (low_bound
4313           && CASE_HIGH ((tree) low_bound->value)
4314           && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
4315                                     low_value) >= 0)
4316         node = low_bound;
4317       /* Check to see if the HIGH_BOUND overlaps.  The low end of that
4318          range is bigger than the low end of the current range, so we
4319          are only interested if the current range is a real range, and
4320          not an ordinary case label.  */
4321       else if (high_bound
4322                && high_value
4323                && (tree_int_cst_compare ((tree) high_bound->key,
4324                                          high_value)
4325                    <= 0))
4326         node = high_bound;
4327     }
4328   /* If there was an overlap, issue an error.  */
4329   if (node)
4330     {
4331       tree duplicate = CASE_LABEL ((tree) node->value);
4332
4333       if (high_value)
4334         {
4335           error ("duplicate (or overlapping) case value");
4336           error ("%Jthis is the first entry overlapping that value", duplicate);
4337         }
4338       else if (low_value)
4339         {
4340           error ("duplicate case value") ;
4341           error ("%Jpreviously used here", duplicate);
4342         }
4343       else
4344         {
4345           error ("multiple default labels in one switch");
4346           error ("%Jthis is the first default label", duplicate);
4347         }
4348       goto error_out;
4349     }
4350
4351   /* Add a CASE_LABEL to the statement-tree.  */
4352   case_label = add_stmt (build_case_label (low_value, high_value, label));
4353   /* Register this case label in the splay tree.  */
4354   splay_tree_insert (cases,
4355                      (splay_tree_key) low_value,
4356                      (splay_tree_value) case_label);
4357
4358   return case_label;
4359
4360  error_out:
4361   /* Add a label so that the back-end doesn't think that the beginning of
4362      the switch is unreachable.  Note that we do not add a case label, as
4363      that just leads to duplicates and thence to failure later on.  */
4364   if (!cases->root)
4365     {
4366       tree t = create_artificial_label ();
4367       add_stmt (build_stmt (LABEL_EXPR, t));
4368     }
4369   return error_mark_node;
4370 }
4371
4372 /* Subroutines of c_do_switch_warnings, called via splay_tree_foreach.
4373    Used to verify that case values match up with enumerator values.  */
4374
4375 static void
4376 match_case_to_enum_1 (tree key, tree type, tree label)
4377 {
4378   char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1];
4379
4380   /* ??? Not working too hard to print the double-word value.
4381      Should perhaps be done with %lwd in the diagnostic routines?  */
4382   if (TREE_INT_CST_HIGH (key) == 0)
4383     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED,
4384               TREE_INT_CST_LOW (key));
4385   else if (!TYPE_UNSIGNED (type)
4386            && TREE_INT_CST_HIGH (key) == -1
4387            && TREE_INT_CST_LOW (key) != 0)
4388     snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED,
4389               -TREE_INT_CST_LOW (key));
4390   else
4391     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX,
4392               TREE_INT_CST_HIGH (key), TREE_INT_CST_LOW (key));
4393
4394   if (TYPE_NAME (type) == 0)
4395     warning (0, "%Jcase value %qs not in enumerated type",
4396              CASE_LABEL (label), buf);
4397   else
4398     warning (0, "%Jcase value %qs not in enumerated type %qT",
4399              CASE_LABEL (label), buf, type);
4400 }
4401
4402 /* Subroutine of c_do_switch_warnings, called via splay_tree_foreach.
4403    Used to verify that case values match up with enumerator values.  */
4404
4405 static int
4406 match_case_to_enum (splay_tree_node node, void *data)
4407 {
4408   tree label = (tree) node->value;
4409   tree type = (tree) data;
4410
4411   /* Skip default case.  */
4412   if (!CASE_LOW (label))
4413     return 0;
4414
4415   /* If CASE_LOW_SEEN is not set, that means CASE_LOW did not appear
4416      when we did our enum->case scan.  Reset our scratch bit after.  */
4417   if (!CASE_LOW_SEEN (label))
4418     match_case_to_enum_1 (CASE_LOW (label), type, label);
4419   else
4420     CASE_LOW_SEEN (label) = 0;
4421
4422   /* If CASE_HIGH is non-null, we have a range.  If CASE_HIGH_SEEN is
4423      not set, that means that CASE_HIGH did not appear when we did our
4424      enum->case scan.  Reset our scratch bit after.  */
4425   if (CASE_HIGH (label))
4426     {
4427       if (!CASE_HIGH_SEEN (label))
4428         match_case_to_enum_1 (CASE_HIGH (label), type, label);
4429       else
4430         CASE_HIGH_SEEN (label) = 0;
4431     }
4432
4433   return 0;
4434 }
4435
4436 /* Handle -Wswitch*.  Called from the front end after parsing the
4437    switch construct.  */
4438 /* ??? Should probably be somewhere generic, since other languages
4439    besides C and C++ would want this.  At the moment, however, C/C++
4440    are the only tree-ssa languages that support enumerations at all,
4441    so the point is moot.  */
4442
4443 void
4444 c_do_switch_warnings (splay_tree cases, location_t switch_location,
4445                       tree type, tree cond)
4446 {
4447   splay_tree_node default_node;
4448   splay_tree_node node;
4449   tree chain;
4450
4451   if (!warn_switch && !warn_switch_enum && !warn_switch_default)
4452     return;
4453
4454   default_node = splay_tree_lookup (cases, (splay_tree_key) NULL);
4455   if (!default_node)
4456     warning (OPT_Wswitch_default, "%Hswitch missing default case",
4457              &switch_location);
4458
4459   /* From here on, we only care about about enumerated types.  */
4460   if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
4461     return;
4462
4463   /* If the switch expression was an enumerated type, check that
4464      exactly all enumeration literals are covered by the cases.
4465      The check is made when -Wswitch was specified and there is no
4466      default case, or when -Wswitch-enum was specified.  */
4467
4468   if (!warn_switch_enum
4469       && !(warn_switch && !default_node))
4470     return;
4471
4472   /* Clearing COND if it is not an integer constant simplifies
4473      the tests inside the loop below.  */
4474   if (TREE_CODE (cond) != INTEGER_CST)
4475     cond = NULL_TREE;
4476
4477   /* The time complexity here is O(N*lg(N)) worst case, but for the
4478       common case of monotonically increasing enumerators, it is
4479       O(N), since the nature of the splay tree will keep the next
4480       element adjacent to the root at all times.  */
4481
4482   for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain))
4483     {
4484       tree value = TREE_VALUE (chain);
4485       node = splay_tree_lookup (cases, (splay_tree_key) value);
4486       if (node)
4487         {
4488           /* Mark the CASE_LOW part of the case entry as seen.  */
4489           tree label = (tree) node->value;
4490           CASE_LOW_SEEN (label) = 1;
4491           continue;
4492         }
4493
4494       /* Even though there wasn't an exact match, there might be a
4495          case range which includes the enumator's value.  */
4496       node = splay_tree_predecessor (cases, (splay_tree_key) value);
4497       if (node && CASE_HIGH ((tree) node->value))
4498         {
4499           tree label = (tree) node->value;
4500           int cmp = tree_int_cst_compare (CASE_HIGH (label), value);
4501           if (cmp >= 0)
4502             {
4503               /* If we match the upper bound exactly, mark the CASE_HIGH
4504                  part of the case entry as seen.  */
4505               if (cmp == 0)
4506                 CASE_HIGH_SEEN (label) = 1;
4507               continue;
4508             }
4509         }
4510
4511       /* We've now determined that this enumerated literal isn't
4512          handled by the case labels of the switch statement.  */
4513
4514       /* If the switch expression is a constant, we only really care
4515          about whether that constant is handled by the switch.  */
4516       if (cond && tree_int_cst_compare (cond, value))
4517         continue;
4518
4519       warning (0, "%Henumeration value %qE not handled in switch",
4520                &switch_location, TREE_PURPOSE (chain));
4521     }
4522
4523   /* Warn if there are case expressions that don't correspond to
4524      enumerators.  This can occur since C and C++ don't enforce
4525      type-checking of assignments to enumeration variables.
4526
4527      The time complexity here is now always O(N) worst case, since
4528      we should have marked both the lower bound and upper bound of
4529      every disjoint case label, with CASE_LOW_SEEN and CASE_HIGH_SEEN
4530      above.  This scan also resets those fields.  */
4531   splay_tree_foreach (cases, match_case_to_enum, type);
4532 }
4533
4534 /* Finish an expression taking the address of LABEL (an
4535    IDENTIFIER_NODE).  Returns an expression for the address.  */
4536
4537 tree
4538 finish_label_address_expr (tree label)
4539 {
4540   tree result;
4541
4542   if (pedantic)
4543     pedwarn ("taking the address of a label is non-standard");
4544
4545   if (label == error_mark_node)
4546     return error_mark_node;
4547
4548   label = lookup_label (label);
4549   if (label == NULL_TREE)
4550     result = null_pointer_node;
4551   else
4552     {
4553       TREE_USED (label) = 1;
4554       result = build1 (ADDR_EXPR, ptr_type_node, label);
4555       /* The current function in not necessarily uninlinable.
4556          Computed gotos are incompatible with inlining, but the value
4557          here could be used only in a diagnostic, for example.  */
4558     }
4559
4560   return result;
4561 }
4562
4563 /* Hook used by expand_expr to expand language-specific tree codes.  */
4564 /* The only things that should go here are bits needed to expand
4565    constant initializers.  Everything else should be handled by the
4566    gimplification routines.  */
4567
4568 rtx
4569 c_expand_expr (tree exp, rtx target, enum machine_mode tmode,
4570                int modifier /* Actually enum_modifier.  */,
4571                rtx *alt_rtl)
4572 {
4573   switch (TREE_CODE (exp))
4574     {
4575     case COMPOUND_LITERAL_EXPR:
4576       {
4577         /* Initialize the anonymous variable declared in the compound
4578            literal, then return the variable.  */
4579         tree decl = COMPOUND_LITERAL_EXPR_DECL (exp);
4580         emit_local_var (decl);
4581         return expand_expr_real (decl, target, tmode, modifier, alt_rtl);
4582       }
4583
4584     default:
4585       gcc_unreachable ();
4586     }
4587 }
4588
4589
4590 /* Generate the RTL for the body of FNDECL.  */
4591
4592 void
4593 c_expand_body (tree fndecl)
4594 {
4595   tree_rest_of_compilation (fndecl);
4596 }
4597
4598 /* Hook used by staticp to handle language-specific tree codes.  */
4599
4600 tree
4601 c_staticp (tree exp)
4602 {
4603   return (TREE_CODE (exp) == COMPOUND_LITERAL_EXPR
4604           && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp))
4605           ? exp : NULL);
4606 }
4607 \f
4608
4609 /* Given a boolean expression ARG, return a tree representing an increment
4610    or decrement (as indicated by CODE) of ARG.  The front end must check for
4611    invalid cases (e.g., decrement in C++).  */
4612 tree
4613 boolean_increment (enum tree_code code, tree arg)
4614 {
4615   tree val;
4616   tree true_res = build_int_cst (TREE_TYPE (arg), 1);
4617
4618   arg = stabilize_reference (arg);
4619   switch (code)
4620     {
4621     case PREINCREMENT_EXPR:
4622       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
4623       break;
4624     case POSTINCREMENT_EXPR:
4625       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
4626       arg = save_expr (arg);
4627       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
4628       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
4629       break;
4630     case PREDECREMENT_EXPR:
4631       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
4632                     invert_truthvalue (arg));
4633       break;
4634     case POSTDECREMENT_EXPR:
4635       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
4636                     invert_truthvalue (arg));
4637       arg = save_expr (arg);
4638       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
4639       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
4640       break;
4641     default:
4642       gcc_unreachable ();
4643     }
4644   TREE_SIDE_EFFECTS (val) = 1;
4645   return val;
4646 }
4647 \f
4648 /* Built-in macros for stddef.h, that require macros defined in this
4649    file.  */
4650 void
4651 c_stddef_cpp_builtins(void)
4652 {
4653   builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0);
4654   builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0);
4655   builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0);
4656   builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0);
4657   builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0);
4658   builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0);
4659 }
4660
4661 static void
4662 c_init_attributes (void)
4663 {
4664   /* Fill in the built_in_attributes array.  */
4665 #define DEF_ATTR_NULL_TREE(ENUM)                                \
4666   built_in_attributes[(int) ENUM] = NULL_TREE;
4667 #define DEF_ATTR_INT(ENUM, VALUE)                               \
4668   built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
4669 #define DEF_ATTR_IDENT(ENUM, STRING)                            \
4670   built_in_attributes[(int) ENUM] = get_identifier (STRING);
4671 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
4672   built_in_attributes[(int) ENUM]                       \
4673     = tree_cons (built_in_attributes[(int) PURPOSE],    \
4674                  built_in_attributes[(int) VALUE],      \
4675                  built_in_attributes[(int) CHAIN]);
4676 #include "builtin-attrs.def"
4677 #undef DEF_ATTR_NULL_TREE
4678 #undef DEF_ATTR_INT
4679 #undef DEF_ATTR_IDENT
4680 #undef DEF_ATTR_TREE_LIST
4681 }
4682
4683 /* Attribute handlers common to C front ends.  */
4684
4685 /* Handle a "packed" attribute; arguments as in
4686    struct attribute_spec.handler.  */
4687
4688 static tree
4689 handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4690                          int flags, bool *no_add_attrs)
4691 {
4692   if (TYPE_P (*node))
4693     {
4694       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4695         *node = build_variant_type_copy (*node);
4696       TYPE_PACKED (*node) = 1;
4697     }
4698   else if (TREE_CODE (*node) == FIELD_DECL)
4699     {
4700       if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT)
4701         warning (OPT_Wattributes,
4702                  "%qE attribute ignored for field of type %qT",
4703                  name, TREE_TYPE (*node));
4704       else
4705         DECL_PACKED (*node) = 1;
4706     }
4707   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
4708      used for DECL_REGISTER.  It wouldn't mean anything anyway.
4709      We can't set DECL_PACKED on the type of a TYPE_DECL, because
4710      that changes what the typedef is typing.  */
4711   else
4712     {
4713       warning (OPT_Wattributes, "%qE attribute ignored", name);
4714       *no_add_attrs = true;
4715     }
4716
4717   return NULL_TREE;
4718 }
4719
4720 /* Handle a "nocommon" attribute; arguments as in
4721    struct attribute_spec.handler.  */
4722
4723 static tree
4724 handle_nocommon_attribute (tree *node, tree name,
4725                            tree ARG_UNUSED (args),
4726                            int ARG_UNUSED (flags), bool *no_add_attrs)
4727 {
4728   if (TREE_CODE (*node) == VAR_DECL)
4729     DECL_COMMON (*node) = 0;
4730   else
4731     {
4732       warning (OPT_Wattributes, "%qE attribute ignored", name);
4733       *no_add_attrs = true;
4734     }
4735
4736   return NULL_TREE;
4737 }
4738
4739 /* Handle a "common" attribute; arguments as in
4740    struct attribute_spec.handler.  */
4741
4742 static tree
4743 handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4744                          int ARG_UNUSED (flags), bool *no_add_attrs)
4745 {
4746   if (TREE_CODE (*node) == VAR_DECL)
4747     DECL_COMMON (*node) = 1;
4748   else
4749     {
4750       warning (OPT_Wattributes, "%qE attribute ignored", name);
4751       *no_add_attrs = true;
4752     }
4753
4754   return NULL_TREE;
4755 }
4756
4757 /* Handle a "noreturn" attribute; arguments as in
4758    struct attribute_spec.handler.  */
4759
4760 static tree
4761 handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4762                            int ARG_UNUSED (flags), bool *no_add_attrs)
4763 {
4764   tree type = TREE_TYPE (*node);
4765
4766   /* See FIXME comment in c_common_attribute_table.  */
4767   if (TREE_CODE (*node) == FUNCTION_DECL)
4768     TREE_THIS_VOLATILE (*node) = 1;
4769   else if (TREE_CODE (type) == POINTER_TYPE
4770            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4771     TREE_TYPE (*node)
4772       = build_pointer_type
4773         (build_type_variant (TREE_TYPE (type),
4774                              TYPE_READONLY (TREE_TYPE (type)), 1));
4775   else
4776     {
4777       warning (OPT_Wattributes, "%qE attribute ignored", name);
4778       *no_add_attrs = true;
4779     }
4780
4781   return NULL_TREE;
4782 }
4783
4784 /* Handle a "hot" and attribute; arguments as in
4785    struct attribute_spec.handler.  */
4786
4787 static tree
4788 handle_hot_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4789                           int ARG_UNUSED (flags), bool *no_add_attrs)
4790 {
4791   if (TREE_CODE (*node) == FUNCTION_DECL)
4792     {
4793       if (lookup_attribute ("cold", DECL_ATTRIBUTES (*node)) != NULL)
4794         {
4795           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
4796                    name, "cold");
4797           *no_add_attrs = true;
4798         }
4799       /* Do nothing else, just set the attribute.  We'll get at
4800          it later with lookup_attribute.  */
4801     }
4802   else
4803     {
4804       warning (OPT_Wattributes, "%qE attribute ignored", name);
4805       *no_add_attrs = true;
4806     }
4807
4808   return NULL_TREE;
4809 }
4810 /* Handle a "cold" and attribute; arguments as in
4811    struct attribute_spec.handler.  */
4812
4813 static tree
4814 handle_cold_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4815                        int ARG_UNUSED (flags), bool *no_add_attrs)
4816 {
4817   if (TREE_CODE (*node) == FUNCTION_DECL)
4818     {
4819       if (lookup_attribute ("hot", DECL_ATTRIBUTES (*node)) != NULL)
4820         {
4821           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
4822                    name, "hot");
4823           *no_add_attrs = true;
4824         }
4825       /* Do nothing else, just set the attribute.  We'll get at
4826          it later with lookup_attribute.  */
4827     }
4828   else
4829     {
4830       warning (OPT_Wattributes, "%qE attribute ignored", name);
4831       *no_add_attrs = true;
4832     }
4833
4834   return NULL_TREE;
4835 }
4836
4837 /* Handle a "noinline" attribute; arguments as in
4838    struct attribute_spec.handler.  */
4839
4840 static tree
4841 handle_noinline_attribute (tree *node, tree name,
4842                            tree ARG_UNUSED (args),
4843                            int ARG_UNUSED (flags), bool *no_add_attrs)
4844 {
4845   if (TREE_CODE (*node) == FUNCTION_DECL)
4846     DECL_UNINLINABLE (*node) = 1;
4847   else
4848     {
4849       warning (OPT_Wattributes, "%qE attribute ignored", name);
4850       *no_add_attrs = true;
4851     }
4852
4853   return NULL_TREE;
4854 }
4855
4856 /* Handle a "always_inline" attribute; arguments as in
4857    struct attribute_spec.handler.  */
4858
4859 static tree
4860 handle_always_inline_attribute (tree *node, tree name,
4861                                 tree ARG_UNUSED (args),
4862                                 int ARG_UNUSED (flags),
4863                                 bool *no_add_attrs)
4864 {
4865   if (TREE_CODE (*node) == FUNCTION_DECL)
4866     {
4867       /* Set the attribute and mark it for disregarding inline
4868          limits.  */
4869       DECL_DISREGARD_INLINE_LIMITS (*node) = 1;
4870     }
4871   else
4872     {
4873       warning (OPT_Wattributes, "%qE attribute ignored", name);
4874       *no_add_attrs = true;
4875     }
4876
4877   return NULL_TREE;
4878 }
4879
4880 /* Handle a "gnu_inline" attribute; arguments as in
4881    struct attribute_spec.handler.  */
4882
4883 static tree
4884 handle_gnu_inline_attribute (tree *node, tree name,
4885                              tree ARG_UNUSED (args),
4886                              int ARG_UNUSED (flags),
4887                              bool *no_add_attrs)
4888 {
4889   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
4890     {
4891       /* Do nothing else, just set the attribute.  We'll get at
4892          it later with lookup_attribute.  */
4893     }
4894   else
4895     {
4896       warning (OPT_Wattributes, "%qE attribute ignored", name);
4897       *no_add_attrs = true;
4898     }
4899
4900   return NULL_TREE;
4901 }
4902
4903 /* Handle a "flatten" attribute; arguments as in
4904    struct attribute_spec.handler.  */
4905
4906 static tree
4907 handle_flatten_attribute (tree *node, tree name,
4908                           tree args ATTRIBUTE_UNUSED,
4909                           int flags ATTRIBUTE_UNUSED, bool *no_add_attrs)
4910 {
4911   if (TREE_CODE (*node) == FUNCTION_DECL)
4912     /* Do nothing else, just set the attribute.  We'll get at
4913        it later with lookup_attribute.  */
4914     ;
4915   else
4916     {
4917       warning (OPT_Wattributes, "%qE attribute ignored", name);
4918       *no_add_attrs = true;
4919     }
4920
4921   return NULL_TREE;
4922 }
4923
4924
4925 /* Handle a "used" attribute; arguments as in
4926    struct attribute_spec.handler.  */
4927
4928 static tree
4929 handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
4930                        int ARG_UNUSED (flags), bool *no_add_attrs)
4931 {
4932   tree node = *pnode;
4933
4934   if (TREE_CODE (node) == FUNCTION_DECL
4935       || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node)))
4936     {
4937       TREE_USED (node) = 1;
4938       DECL_PRESERVE_P (node) = 1;
4939     }
4940   else
4941     {
4942       warning (OPT_Wattributes, "%qE attribute ignored", name);
4943       *no_add_attrs = true;
4944     }
4945
4946   return NULL_TREE;
4947 }
4948
4949 /* Handle a "unused" attribute; arguments as in
4950    struct attribute_spec.handler.  */
4951
4952 static tree
4953 handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4954                          int flags, bool *no_add_attrs)
4955 {
4956   if (DECL_P (*node))
4957     {
4958       tree decl = *node;
4959
4960       if (TREE_CODE (decl) == PARM_DECL
4961           || TREE_CODE (decl) == VAR_DECL
4962           || TREE_CODE (decl) == FUNCTION_DECL
4963           || TREE_CODE (decl) == LABEL_DECL
4964           || TREE_CODE (decl) == TYPE_DECL)
4965         TREE_USED (decl) = 1;
4966       else
4967         {
4968           warning (OPT_Wattributes, "%qE attribute ignored", name);
4969           *no_add_attrs = true;
4970         }
4971     }
4972   else
4973     {
4974       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4975         *node = build_variant_type_copy (*node);
4976       TREE_USED (*node) = 1;
4977     }
4978
4979   return NULL_TREE;
4980 }
4981
4982 /* Handle a "externally_visible" attribute; arguments as in
4983    struct attribute_spec.handler.  */
4984
4985 static tree
4986 handle_externally_visible_attribute (tree *pnode, tree name,
4987                                      tree ARG_UNUSED (args),
4988                                      int ARG_UNUSED (flags),
4989                                      bool *no_add_attrs)
4990 {
4991   tree node = *pnode;
4992
4993   if (TREE_CODE (node) == FUNCTION_DECL || TREE_CODE (node) == VAR_DECL)
4994     {
4995       if ((!TREE_STATIC (node) && TREE_CODE (node) != FUNCTION_DECL
4996            && !DECL_EXTERNAL (node)) || !TREE_PUBLIC (node))
4997         {
4998           warning (OPT_Wattributes,
4999                    "%qE attribute have effect only on public objects", name);
5000           *no_add_attrs = true;
5001         }
5002     }
5003   else
5004     {
5005       warning (OPT_Wattributes, "%qE attribute ignored", name);
5006       *no_add_attrs = true;
5007     }
5008
5009   return NULL_TREE;
5010 }
5011
5012 /* Handle a "const" attribute; arguments as in
5013    struct attribute_spec.handler.  */
5014
5015 static tree
5016 handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5017                         int ARG_UNUSED (flags), bool *no_add_attrs)
5018 {
5019   tree type = TREE_TYPE (*node);
5020
5021   /* See FIXME comment on noreturn in c_common_attribute_table.  */
5022   if (TREE_CODE (*node) == FUNCTION_DECL)
5023     TREE_READONLY (*node) = 1;
5024   else if (TREE_CODE (type) == POINTER_TYPE
5025            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
5026     TREE_TYPE (*node)
5027       = build_pointer_type
5028         (build_type_variant (TREE_TYPE (type), 1,
5029                              TREE_THIS_VOLATILE (TREE_TYPE (type))));
5030   else
5031     {
5032       warning (OPT_Wattributes, "%qE attribute ignored", name);
5033       *no_add_attrs = true;
5034     }
5035
5036   return NULL_TREE;
5037 }
5038
5039 /* Handle a "transparent_union" attribute; arguments as in
5040    struct attribute_spec.handler.  */
5041
5042 static tree
5043 handle_transparent_union_attribute (tree *node, tree name,
5044                                     tree ARG_UNUSED (args), int flags,
5045                                     bool *no_add_attrs)
5046 {
5047   tree type = NULL;
5048
5049   *no_add_attrs = true;
5050
5051   if (DECL_P (*node))
5052     {
5053       if (TREE_CODE (*node) != TYPE_DECL)
5054         goto ignored;
5055       node = &TREE_TYPE (*node);
5056       type = *node;
5057     }
5058   else if (TYPE_P (*node))
5059     type = *node;
5060   else
5061     goto ignored;
5062
5063   if (TREE_CODE (type) == UNION_TYPE)
5064     {
5065       /* When IN_PLACE is set, leave the check for FIELDS and MODE to
5066          the code in finish_struct.  */
5067       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5068         {
5069           if (TYPE_FIELDS (type) == NULL_TREE
5070               || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type)))
5071             goto ignored;
5072
5073           /* A type variant isn't good enough, since we don't a cast
5074              to such a type removed as a no-op.  */
5075           *node = type = build_duplicate_type (type);
5076         }
5077
5078       TYPE_TRANSPARENT_UNION (type) = 1;
5079       return NULL_TREE;
5080     }
5081
5082  ignored:
5083   warning (OPT_Wattributes, "%qE attribute ignored", name);
5084   return NULL_TREE;
5085 }
5086
5087 /* Subroutine of handle_{con,de}structor_attribute.  Evaluate ARGS to
5088    get the requested priority for a constructor or destructor,
5089    possibly issuing diagnostics for invalid or reserved
5090    priorities.  */
5091
5092 static priority_type
5093 get_priority (tree args, bool is_destructor)
5094 {
5095   HOST_WIDE_INT pri;
5096   tree arg;
5097
5098   if (!args)
5099     return DEFAULT_INIT_PRIORITY;
5100
5101   if (!SUPPORTS_INIT_PRIORITY)
5102     {
5103       if (is_destructor)
5104         error ("destructor priorities are not supported");
5105       else
5106         error ("constructor priorities are not supported");
5107       return DEFAULT_INIT_PRIORITY;
5108     }
5109
5110   arg = TREE_VALUE (args);
5111   if (!host_integerp (arg, /*pos=*/0)
5112       || !INTEGRAL_TYPE_P (TREE_TYPE (arg)))
5113     goto invalid;
5114
5115   pri = tree_low_cst (TREE_VALUE (args), /*pos=*/0);
5116   if (pri < 0 || pri > MAX_INIT_PRIORITY)
5117     goto invalid;
5118
5119   if (pri <= MAX_RESERVED_INIT_PRIORITY)
5120     {
5121       if (is_destructor)
5122         warning (0,
5123                  "destructor priorities from 0 to %d are reserved "
5124                  "for the implementation",
5125                  MAX_RESERVED_INIT_PRIORITY);
5126       else
5127         warning (0,
5128                  "constructor priorities from 0 to %d are reserved "
5129                  "for the implementation",
5130                  MAX_RESERVED_INIT_PRIORITY);
5131     }
5132   return pri;
5133
5134  invalid:
5135   if (is_destructor)
5136     error ("destructor priorities must be integers from 0 to %d inclusive",
5137            MAX_INIT_PRIORITY);
5138   else
5139     error ("constructor priorities must be integers from 0 to %d inclusive",
5140            MAX_INIT_PRIORITY);
5141   return DEFAULT_INIT_PRIORITY;
5142 }
5143
5144 /* Handle a "constructor" attribute; arguments as in
5145    struct attribute_spec.handler.  */
5146
5147 static tree
5148 handle_constructor_attribute (tree *node, tree name, tree args,
5149                               int ARG_UNUSED (flags),
5150                               bool *no_add_attrs)
5151 {
5152   tree decl = *node;
5153   tree type = TREE_TYPE (decl);
5154
5155   if (TREE_CODE (decl) == FUNCTION_DECL
5156       && TREE_CODE (type) == FUNCTION_TYPE
5157       && decl_function_context (decl) == 0)
5158     {
5159       priority_type priority;
5160       DECL_STATIC_CONSTRUCTOR (decl) = 1;
5161       priority = get_priority (args, /*is_destructor=*/false);
5162       SET_DECL_INIT_PRIORITY (decl, priority);
5163       TREE_USED (decl) = 1;
5164     }
5165   else
5166     {
5167       warning (OPT_Wattributes, "%qE attribute ignored", name);
5168       *no_add_attrs = true;
5169     }
5170
5171   return NULL_TREE;
5172 }
5173
5174 /* Handle a "destructor" attribute; arguments as in
5175    struct attribute_spec.handler.  */
5176
5177 static tree
5178 handle_destructor_attribute (tree *node, tree name, tree args,
5179                              int ARG_UNUSED (flags),
5180                              bool *no_add_attrs)
5181 {
5182   tree decl = *node;
5183   tree type = TREE_TYPE (decl);
5184
5185   if (TREE_CODE (decl) == FUNCTION_DECL
5186       && TREE_CODE (type) == FUNCTION_TYPE
5187       && decl_function_context (decl) == 0)
5188     {
5189       priority_type priority;
5190       DECL_STATIC_DESTRUCTOR (decl) = 1;
5191       priority = get_priority (args, /*is_destructor=*/true);
5192       SET_DECL_FINI_PRIORITY (decl, priority);
5193       TREE_USED (decl) = 1;
5194     }
5195   else
5196     {
5197       warning (OPT_Wattributes, "%qE attribute ignored", name);
5198       *no_add_attrs = true;
5199     }
5200
5201   return NULL_TREE;
5202 }
5203
5204 /* Handle a "mode" attribute; arguments as in
5205    struct attribute_spec.handler.  */
5206
5207 static tree
5208 handle_mode_attribute (tree *node, tree name, tree args,
5209                        int ARG_UNUSED (flags), bool *no_add_attrs)
5210 {
5211   tree type = *node;
5212
5213   *no_add_attrs = true;
5214
5215   if (TREE_CODE (TREE_VALUE (args)) != IDENTIFIER_NODE)
5216     warning (OPT_Wattributes, "%qE attribute ignored", name);
5217   else
5218     {
5219       int j;
5220       const char *p = IDENTIFIER_POINTER (TREE_VALUE (args));
5221       int len = strlen (p);
5222       enum machine_mode mode = VOIDmode;
5223       tree typefm;
5224       bool valid_mode;
5225
5226       if (len > 4 && p[0] == '_' && p[1] == '_'
5227           && p[len - 1] == '_' && p[len - 2] == '_')
5228         {
5229           char *newp = (char *) alloca (len - 1);
5230
5231           strcpy (newp, &p[2]);
5232           newp[len - 4] = '\0';
5233           p = newp;
5234         }
5235
5236       /* Change this type to have a type with the specified mode.
5237          First check for the special modes.  */
5238       if (!strcmp (p, "byte"))
5239         mode = byte_mode;
5240       else if (!strcmp (p, "word"))
5241         mode = word_mode;
5242       else if (!strcmp (p, "pointer"))
5243         mode = ptr_mode;
5244       else if (!strcmp (p, "libgcc_cmp_return"))
5245         mode = targetm.libgcc_cmp_return_mode ();
5246       else if (!strcmp (p, "libgcc_shift_count"))
5247         mode = targetm.libgcc_shift_count_mode ();
5248       else
5249         for (j = 0; j < NUM_MACHINE_MODES; j++)
5250           if (!strcmp (p, GET_MODE_NAME (j)))
5251             {
5252               mode = (enum machine_mode) j;
5253               break;
5254             }
5255
5256       if (mode == VOIDmode)
5257         {
5258           error ("unknown machine mode %qs", p);
5259           return NULL_TREE;
5260         }
5261
5262       valid_mode = false;
5263       switch (GET_MODE_CLASS (mode))
5264         {
5265         case MODE_INT:
5266         case MODE_PARTIAL_INT:
5267         case MODE_FLOAT:
5268         case MODE_DECIMAL_FLOAT:
5269         case MODE_FRACT:
5270         case MODE_UFRACT:
5271         case MODE_ACCUM:
5272         case MODE_UACCUM:
5273           valid_mode = targetm.scalar_mode_supported_p (mode);
5274           break;
5275
5276         case MODE_COMPLEX_INT:
5277         case MODE_COMPLEX_FLOAT:
5278           valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode));
5279           break;
5280
5281         case MODE_VECTOR_INT:
5282         case MODE_VECTOR_FLOAT:
5283         case MODE_VECTOR_FRACT:
5284         case MODE_VECTOR_UFRACT:
5285         case MODE_VECTOR_ACCUM:
5286         case MODE_VECTOR_UACCUM:
5287           warning (OPT_Wattributes, "specifying vector types with "
5288                    "__attribute__ ((mode)) is deprecated");
5289           warning (OPT_Wattributes,
5290                    "use __attribute__ ((vector_size)) instead");
5291           valid_mode = vector_mode_valid_p (mode);
5292           break;
5293
5294         default:
5295           break;
5296         }
5297       if (!valid_mode)
5298         {
5299           error ("unable to emulate %qs", p);
5300           return NULL_TREE;
5301         }
5302
5303       if (POINTER_TYPE_P (type))
5304         {
5305           tree (*fn)(tree, enum machine_mode, bool);
5306
5307           if (!targetm.valid_pointer_mode (mode))
5308             {
5309               error ("invalid pointer mode %qs", p);
5310               return NULL_TREE;
5311             }
5312
5313           if (TREE_CODE (type) == POINTER_TYPE)
5314             fn = build_pointer_type_for_mode;
5315           else
5316             fn = build_reference_type_for_mode;
5317           typefm = fn (TREE_TYPE (type), mode, false);
5318         }
5319       else
5320         {
5321           /* For fixed-point modes, we need to test if the signness of type
5322              and the machine mode are consistent.  */
5323           if (ALL_FIXED_POINT_MODE_P (mode)
5324               && TYPE_UNSIGNED (type) != UNSIGNED_FIXED_POINT_MODE_P (mode))
5325             {
5326               error ("signness of type and machine mode %qs don't match", p);
5327               return NULL_TREE;
5328             }
5329           /* For fixed-point modes, we need to pass saturating info.  */
5330           typefm = lang_hooks.types.type_for_mode (mode,
5331                         ALL_FIXED_POINT_MODE_P (mode) ? TYPE_SATURATING (type)
5332                                                       : TYPE_UNSIGNED (type));
5333         }
5334
5335       if (typefm == NULL_TREE)
5336         {
5337           error ("no data type for mode %qs", p);
5338           return NULL_TREE;
5339         }
5340       else if (TREE_CODE (type) == ENUMERAL_TYPE)
5341         {
5342           /* For enumeral types, copy the precision from the integer
5343              type returned above.  If not an INTEGER_TYPE, we can't use
5344              this mode for this type.  */
5345           if (TREE_CODE (typefm) != INTEGER_TYPE)
5346             {
5347               error ("cannot use mode %qs for enumeral types", p);
5348               return NULL_TREE;
5349             }
5350
5351           if (flags & ATTR_FLAG_TYPE_IN_PLACE)
5352             {
5353               TYPE_PRECISION (type) = TYPE_PRECISION (typefm);
5354               typefm = type;
5355             }
5356           else
5357             {
5358               /* We cannot build a type variant, as there's code that assumes
5359                  that TYPE_MAIN_VARIANT has the same mode.  This includes the
5360                  debug generators.  Instead, create a subrange type.  This
5361                  results in all of the enumeral values being emitted only once
5362                  in the original, and the subtype gets them by reference.  */
5363               if (TYPE_UNSIGNED (type))
5364                 typefm = make_unsigned_type (TYPE_PRECISION (typefm));
5365               else
5366                 typefm = make_signed_type (TYPE_PRECISION (typefm));
5367               TREE_TYPE (typefm) = type;
5368             }
5369         }
5370       else if (VECTOR_MODE_P (mode)
5371                ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm))
5372                : TREE_CODE (type) != TREE_CODE (typefm))
5373         {
5374           error ("mode %qs applied to inappropriate type", p);
5375           return NULL_TREE;
5376         }
5377
5378       *node = typefm;
5379     }
5380
5381   return NULL_TREE;
5382 }
5383
5384 /* Handle a "section" attribute; arguments as in
5385    struct attribute_spec.handler.  */
5386
5387 static tree
5388 handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5389                           int ARG_UNUSED (flags), bool *no_add_attrs)
5390 {
5391   tree decl = *node;
5392
5393   if (targetm.have_named_sections)
5394     {
5395       user_defined_section_attribute = true;
5396
5397       if ((TREE_CODE (decl) == FUNCTION_DECL
5398            || TREE_CODE (decl) == VAR_DECL)
5399           && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
5400         {
5401           if (TREE_CODE (decl) == VAR_DECL
5402               && current_function_decl != NULL_TREE
5403               && !TREE_STATIC (decl))
5404             {
5405               error ("%Jsection attribute cannot be specified for "
5406                      "local variables", decl);
5407               *no_add_attrs = true;
5408             }
5409
5410           /* The decl may have already been given a section attribute
5411              from a previous declaration.  Ensure they match.  */
5412           else if (DECL_SECTION_NAME (decl) != NULL_TREE
5413                    && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
5414                               TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
5415             {
5416               error ("section of %q+D conflicts with previous declaration",
5417                      *node);
5418               *no_add_attrs = true;
5419             }
5420           else
5421             DECL_SECTION_NAME (decl) = TREE_VALUE (args);
5422         }
5423       else
5424         {
5425           error ("section attribute not allowed for %q+D", *node);
5426           *no_add_attrs = true;
5427         }
5428     }
5429   else
5430     {
5431       error ("%Jsection attributes are not supported for this target", *node);
5432       *no_add_attrs = true;
5433     }
5434
5435   return NULL_TREE;
5436 }
5437
5438 /* Handle a "aligned" attribute; arguments as in
5439    struct attribute_spec.handler.  */
5440
5441 static tree
5442 handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5443                           int flags, bool *no_add_attrs)
5444 {
5445   tree decl = NULL_TREE;
5446   tree *type = NULL;
5447   int is_type = 0;
5448   tree align_expr = (args ? TREE_VALUE (args)
5449                      : size_int (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
5450   int i;
5451
5452   if (DECL_P (*node))
5453     {
5454       decl = *node;
5455       type = &TREE_TYPE (decl);
5456       is_type = TREE_CODE (*node) == TYPE_DECL;
5457     }
5458   else if (TYPE_P (*node))
5459     type = node, is_type = 1;
5460
5461   if (TREE_CODE (align_expr) != INTEGER_CST)
5462     {
5463       error ("requested alignment is not a constant");
5464       *no_add_attrs = true;
5465     }
5466   else if ((i = tree_log2 (align_expr)) == -1)
5467     {
5468       error ("requested alignment is not a power of 2");
5469       *no_add_attrs = true;
5470     }
5471   else if (i > HOST_BITS_PER_INT - 2)
5472     {
5473       error ("requested alignment is too large");
5474       *no_add_attrs = true;
5475     }
5476   else if (is_type)
5477     {
5478       /* If we have a TYPE_DECL, then copy the type, so that we
5479          don't accidentally modify a builtin type.  See pushdecl.  */
5480       if (decl && TREE_TYPE (decl) != error_mark_node
5481           && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
5482         {
5483           tree tt = TREE_TYPE (decl);
5484           *type = build_variant_type_copy (*type);
5485           DECL_ORIGINAL_TYPE (decl) = tt;
5486           TYPE_NAME (*type) = decl;
5487           TREE_USED (*type) = TREE_USED (decl);
5488           TREE_TYPE (decl) = *type;
5489         }
5490       else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5491         *type = build_variant_type_copy (*type);
5492
5493       TYPE_ALIGN (*type) = (1 << i) * BITS_PER_UNIT;
5494       TYPE_USER_ALIGN (*type) = 1;
5495     }
5496   else if (! VAR_OR_FUNCTION_DECL_P (decl)
5497            && TREE_CODE (decl) != FIELD_DECL)
5498     {
5499       error ("alignment may not be specified for %q+D", decl);
5500       *no_add_attrs = true;
5501     }
5502   else if (TREE_CODE (decl) == FUNCTION_DECL
5503            && DECL_ALIGN (decl) > (1 << i) * BITS_PER_UNIT)
5504     {
5505       if (DECL_USER_ALIGN (decl))
5506         error ("alignment for %q+D was previously specified as %d "
5507                "and may not be decreased", decl,
5508                DECL_ALIGN (decl) / BITS_PER_UNIT);
5509       else
5510         error ("alignment for %q+D must be at least %d", decl,
5511                DECL_ALIGN (decl) / BITS_PER_UNIT);
5512       *no_add_attrs = true;
5513     }
5514   else
5515     {
5516       DECL_ALIGN (decl) = (1 << i) * BITS_PER_UNIT;
5517       DECL_USER_ALIGN (decl) = 1;
5518     }
5519
5520   return NULL_TREE;
5521 }
5522
5523 /* Handle a "weak" attribute; arguments as in
5524    struct attribute_spec.handler.  */
5525
5526 static tree
5527 handle_weak_attribute (tree *node, tree name,
5528                        tree ARG_UNUSED (args),
5529                        int ARG_UNUSED (flags),
5530                        bool * ARG_UNUSED (no_add_attrs))
5531 {
5532   if (TREE_CODE (*node) == FUNCTION_DECL
5533       || TREE_CODE (*node) == VAR_DECL)
5534     declare_weak (*node);
5535   else
5536     warning (OPT_Wattributes, "%qE attribute ignored", name);
5537
5538
5539   return NULL_TREE;
5540 }
5541
5542 /* Handle an "alias" attribute; arguments as in
5543    struct attribute_spec.handler.  */
5544
5545 static tree
5546 handle_alias_attribute (tree *node, tree name, tree args,
5547                         int ARG_UNUSED (flags), bool *no_add_attrs)
5548 {
5549   tree decl = *node;
5550
5551   if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
5552       || (TREE_CODE (decl) != FUNCTION_DECL
5553           && TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl))
5554       /* A static variable declaration is always a tentative definition,
5555          but the alias is a non-tentative definition which overrides.  */
5556       || (TREE_CODE (decl) != FUNCTION_DECL
5557           && ! TREE_PUBLIC (decl) && DECL_INITIAL (decl)))
5558     {
5559       error ("%q+D defined both normally and as an alias", decl);
5560       *no_add_attrs = true;
5561     }
5562
5563   /* Note that the very first time we process a nested declaration,
5564      decl_function_context will not be set.  Indeed, *would* never
5565      be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that
5566      we do below.  After such frobbery, pushdecl would set the context.
5567      In any case, this is never what we want.  */
5568   else if (decl_function_context (decl) == 0 && current_function_decl == NULL)
5569     {
5570       tree id;
5571
5572       id = TREE_VALUE (args);
5573       if (TREE_CODE (id) != STRING_CST)
5574         {
5575           error ("alias argument not a string");
5576           *no_add_attrs = true;
5577           return NULL_TREE;
5578         }
5579       id = get_identifier (TREE_STRING_POINTER (id));
5580       /* This counts as a use of the object pointed to.  */
5581       TREE_USED (id) = 1;
5582
5583       if (TREE_CODE (decl) == FUNCTION_DECL)
5584         DECL_INITIAL (decl) = error_mark_node;
5585       else
5586         {
5587           if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5588             DECL_EXTERNAL (decl) = 1;
5589           else
5590             DECL_EXTERNAL (decl) = 0;
5591           TREE_STATIC (decl) = 1;
5592         }
5593     }
5594   else
5595     {
5596       warning (OPT_Wattributes, "%qE attribute ignored", name);
5597       *no_add_attrs = true;
5598     }
5599
5600   return NULL_TREE;
5601 }
5602
5603 /* Handle a "weakref" attribute; arguments as in struct
5604    attribute_spec.handler.  */
5605
5606 static tree
5607 handle_weakref_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5608                           int flags, bool *no_add_attrs)
5609 {
5610   tree attr = NULL_TREE;
5611
5612   /* We must ignore the attribute when it is associated with
5613      local-scoped decls, since attribute alias is ignored and many
5614      such symbols do not even have a DECL_WEAK field.  */
5615   if (decl_function_context (*node) || current_function_decl)
5616     {
5617       warning (OPT_Wattributes, "%qE attribute ignored", name);
5618       *no_add_attrs = true;
5619       return NULL_TREE;
5620     }
5621
5622   /* The idea here is that `weakref("name")' mutates into `weakref,
5623      alias("name")', and weakref without arguments, in turn,
5624      implicitly adds weak. */
5625
5626   if (args)
5627     {
5628       attr = tree_cons (get_identifier ("alias"), args, attr);
5629       attr = tree_cons (get_identifier ("weakref"), NULL_TREE, attr);
5630
5631       *no_add_attrs = true;
5632
5633       decl_attributes (node, attr, flags);
5634     }
5635   else
5636     {
5637       if (lookup_attribute ("alias", DECL_ATTRIBUTES (*node)))
5638         error ("%Jweakref attribute must appear before alias attribute",
5639                *node);
5640
5641       /* Can't call declare_weak because it wants this to be TREE_PUBLIC,
5642          and that isn't supported; and because it wants to add it to
5643          the list of weak decls, which isn't helpful.  */
5644       DECL_WEAK (*node) = 1;
5645     }
5646
5647   return NULL_TREE;
5648 }
5649
5650 /* Handle an "visibility" attribute; arguments as in
5651    struct attribute_spec.handler.  */
5652
5653 static tree
5654 handle_visibility_attribute (tree *node, tree name, tree args,
5655                              int ARG_UNUSED (flags),
5656                              bool *ARG_UNUSED (no_add_attrs))
5657 {
5658   tree decl = *node;
5659   tree id = TREE_VALUE (args);
5660   enum symbol_visibility vis;
5661
5662   if (TYPE_P (*node))
5663     {
5664       if (TREE_CODE (*node) == ENUMERAL_TYPE)
5665         /* OK */;
5666       else if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE)
5667         {
5668           warning (OPT_Wattributes, "%qE attribute ignored on non-class types",
5669                    name);
5670           return NULL_TREE;
5671         }
5672       else if (TYPE_FIELDS (*node))
5673         {
5674           error ("%qE attribute ignored because %qT is already defined",
5675                  name, *node);
5676           return NULL_TREE;
5677         }
5678     }
5679   else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl))
5680     {
5681       warning (OPT_Wattributes, "%qE attribute ignored", name);
5682       return NULL_TREE;
5683     }
5684
5685   if (TREE_CODE (id) != STRING_CST)
5686     {
5687       error ("visibility argument not a string");
5688       return NULL_TREE;
5689     }
5690
5691   /*  If this is a type, set the visibility on the type decl.  */
5692   if (TYPE_P (decl))
5693     {
5694       decl = TYPE_NAME (decl);
5695       if (!decl)
5696         return NULL_TREE;
5697       if (TREE_CODE (decl) == IDENTIFIER_NODE)
5698         {
5699            warning (OPT_Wattributes, "%qE attribute ignored on types",
5700                     name);
5701            return NULL_TREE;
5702         }
5703     }
5704
5705   if (strcmp (TREE_STRING_POINTER (id), "default") == 0)
5706     vis = VISIBILITY_DEFAULT;
5707   else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0)
5708     vis = VISIBILITY_INTERNAL;
5709   else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0)
5710     vis = VISIBILITY_HIDDEN;
5711   else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0)
5712     vis = VISIBILITY_PROTECTED;
5713   else
5714     {
5715       error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\"");
5716       vis = VISIBILITY_DEFAULT;
5717     }
5718
5719   if (DECL_VISIBILITY_SPECIFIED (decl)
5720       && vis != DECL_VISIBILITY (decl))
5721     {
5722       tree attributes = (TYPE_P (*node)
5723                          ? TYPE_ATTRIBUTES (*node)
5724                          : DECL_ATTRIBUTES (decl));
5725       if (lookup_attribute ("visibility", attributes))
5726         error ("%qD redeclared with different visibility", decl);
5727       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
5728                && lookup_attribute ("dllimport", attributes))
5729         error ("%qD was declared %qs which implies default visibility",
5730                decl, "dllimport");
5731       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
5732                && lookup_attribute ("dllexport", attributes))
5733         error ("%qD was declared %qs which implies default visibility",
5734                decl, "dllexport");
5735     }
5736
5737   DECL_VISIBILITY (decl) = vis;
5738   DECL_VISIBILITY_SPECIFIED (decl) = 1;
5739
5740   /* Go ahead and attach the attribute to the node as well.  This is needed
5741      so we can determine whether we have VISIBILITY_DEFAULT because the
5742      visibility was not specified, or because it was explicitly overridden
5743      from the containing scope.  */
5744
5745   return NULL_TREE;
5746 }
5747
5748 /* Determine the ELF symbol visibility for DECL, which is either a
5749    variable or a function.  It is an error to use this function if a
5750    definition of DECL is not available in this translation unit.
5751    Returns true if the final visibility has been determined by this
5752    function; false if the caller is free to make additional
5753    modifications.  */
5754
5755 bool
5756 c_determine_visibility (tree decl)
5757 {
5758   gcc_assert (TREE_CODE (decl) == VAR_DECL
5759               || TREE_CODE (decl) == FUNCTION_DECL);
5760
5761   /* If the user explicitly specified the visibility with an
5762      attribute, honor that.  DECL_VISIBILITY will have been set during
5763      the processing of the attribute.  We check for an explicit
5764      attribute, rather than just checking DECL_VISIBILITY_SPECIFIED,
5765      to distinguish the use of an attribute from the use of a "#pragma
5766      GCC visibility push(...)"; in the latter case we still want other
5767      considerations to be able to overrule the #pragma.  */
5768   if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl))
5769       || (TARGET_DLLIMPORT_DECL_ATTRIBUTES
5770           && (lookup_attribute ("dllimport", DECL_ATTRIBUTES (decl))
5771               || lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))))
5772     return true;
5773
5774   /* Set default visibility to whatever the user supplied with
5775      visibility_specified depending on #pragma GCC visibility.  */
5776   if (!DECL_VISIBILITY_SPECIFIED (decl))
5777     {
5778       DECL_VISIBILITY (decl) = default_visibility;
5779       DECL_VISIBILITY_SPECIFIED (decl) = visibility_options.inpragma;
5780     }
5781   return false;
5782 }
5783
5784 /* Handle an "tls_model" attribute; arguments as in
5785    struct attribute_spec.handler.  */
5786
5787 static tree
5788 handle_tls_model_attribute (tree *node, tree name, tree args,
5789                             int ARG_UNUSED (flags), bool *no_add_attrs)
5790 {
5791   tree id;
5792   tree decl = *node;
5793   enum tls_model kind;
5794
5795   *no_add_attrs = true;
5796
5797   if (!DECL_THREAD_LOCAL_P (decl))
5798     {
5799       warning (OPT_Wattributes, "%qE attribute ignored", name);
5800       return NULL_TREE;
5801     }
5802
5803   kind = DECL_TLS_MODEL (decl);
5804   id = TREE_VALUE (args);
5805   if (TREE_CODE (id) != STRING_CST)
5806     {
5807       error ("tls_model argument not a string");
5808       return NULL_TREE;
5809     }
5810
5811   if (!strcmp (TREE_STRING_POINTER (id), "local-exec"))
5812     kind = TLS_MODEL_LOCAL_EXEC;
5813   else if (!strcmp (TREE_STRING_POINTER (id), "initial-exec"))
5814     kind = TLS_MODEL_INITIAL_EXEC;
5815   else if (!strcmp (TREE_STRING_POINTER (id), "local-dynamic"))
5816     kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
5817   else if (!strcmp (TREE_STRING_POINTER (id), "global-dynamic"))
5818     kind = TLS_MODEL_GLOBAL_DYNAMIC;
5819   else
5820     error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\"");
5821
5822   DECL_TLS_MODEL (decl) = kind;
5823   return NULL_TREE;
5824 }
5825
5826 /* Handle a "no_instrument_function" attribute; arguments as in
5827    struct attribute_spec.handler.  */
5828
5829 static tree
5830 handle_no_instrument_function_attribute (tree *node, tree name,
5831                                          tree ARG_UNUSED (args),
5832                                          int ARG_UNUSED (flags),
5833                                          bool *no_add_attrs)
5834 {
5835   tree decl = *node;
5836
5837   if (TREE_CODE (decl) != FUNCTION_DECL)
5838     {
5839       error ("%J%qE attribute applies only to functions", decl, name);
5840       *no_add_attrs = true;
5841     }
5842   else if (DECL_INITIAL (decl))
5843     {
5844       error ("%Jcan%'t set %qE attribute after definition", decl, name);
5845       *no_add_attrs = true;
5846     }
5847   else
5848     DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
5849
5850   return NULL_TREE;
5851 }
5852
5853 /* Handle a "malloc" attribute; arguments as in
5854    struct attribute_spec.handler.  */
5855
5856 static tree
5857 handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5858                          int ARG_UNUSED (flags), bool *no_add_attrs)
5859 {
5860   if (TREE_CODE (*node) == FUNCTION_DECL
5861       && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node))))
5862     DECL_IS_MALLOC (*node) = 1;
5863   else
5864     {
5865       warning (OPT_Wattributes, "%qE attribute ignored", name);
5866       *no_add_attrs = true;
5867     }
5868
5869   return NULL_TREE;
5870 }
5871
5872 /* Handle a "alloc_size" attribute; arguments as in
5873    struct attribute_spec.handler.  */
5874
5875 static tree
5876 handle_alloc_size_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5877                              int ARG_UNUSED (flags), bool *no_add_attrs)
5878 {
5879   tree params = TYPE_ARG_TYPES (*node);
5880   unsigned arg_count = 0;
5881
5882   for (; TREE_CHAIN (params); params = TREE_CHAIN (params))
5883     arg_count ++;
5884
5885   for (; args; args = TREE_CHAIN (args))
5886     {
5887       tree position = TREE_VALUE (args);
5888
5889       if (TREE_CODE (position) != INTEGER_CST
5890           || TREE_INT_CST_HIGH (position)
5891           || TREE_INT_CST_LOW (position) < 1
5892           || TREE_INT_CST_LOW (position) > arg_count )
5893         {
5894           warning (OPT_Wattributes,
5895                    "alloc_size parameter outside range");
5896           *no_add_attrs = true;
5897           return NULL_TREE;
5898         }
5899     }
5900   return NULL_TREE;
5901 }
5902
5903 /* Handle a "returns_twice" attribute; arguments as in
5904    struct attribute_spec.handler.  */
5905
5906 static tree
5907 handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5908                          int ARG_UNUSED (flags), bool *no_add_attrs)
5909 {
5910   if (TREE_CODE (*node) == FUNCTION_DECL)
5911     DECL_IS_RETURNS_TWICE (*node) = 1;
5912   else
5913     {
5914       warning (OPT_Wattributes, "%qE attribute ignored", name);
5915       *no_add_attrs = true;
5916     }
5917
5918   return NULL_TREE;
5919 }
5920
5921 /* Handle a "no_limit_stack" attribute; arguments as in
5922    struct attribute_spec.handler.  */
5923
5924 static tree
5925 handle_no_limit_stack_attribute (tree *node, tree name,
5926                                  tree ARG_UNUSED (args),
5927                                  int ARG_UNUSED (flags),
5928                                  bool *no_add_attrs)
5929 {
5930   tree decl = *node;
5931
5932   if (TREE_CODE (decl) != FUNCTION_DECL)
5933     {
5934       error ("%J%qE attribute applies only to functions", decl, name);
5935       *no_add_attrs = true;
5936     }
5937   else if (DECL_INITIAL (decl))
5938     {
5939       error ("%Jcan%'t set %qE attribute after definition", decl, name);
5940       *no_add_attrs = true;
5941     }
5942   else
5943     DECL_NO_LIMIT_STACK (decl) = 1;
5944
5945   return NULL_TREE;
5946 }
5947
5948 /* Handle a "pure" attribute; arguments as in
5949    struct attribute_spec.handler.  */
5950
5951 static tree
5952 handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5953                        int ARG_UNUSED (flags), bool *no_add_attrs)
5954 {
5955   if (TREE_CODE (*node) == FUNCTION_DECL)
5956     DECL_IS_PURE (*node) = 1;
5957   /* ??? TODO: Support types.  */
5958   else
5959     {
5960       warning (OPT_Wattributes, "%qE attribute ignored", name);
5961       *no_add_attrs = true;
5962     }
5963
5964   return NULL_TREE;
5965 }
5966
5967 /* Handle a "no vops" attribute; arguments as in
5968    struct attribute_spec.handler.  */
5969
5970 static tree
5971 handle_novops_attribute (tree *node, tree ARG_UNUSED (name),
5972                          tree ARG_UNUSED (args), int ARG_UNUSED (flags),
5973                          bool *ARG_UNUSED (no_add_attrs))
5974 {
5975   gcc_assert (TREE_CODE (*node) == FUNCTION_DECL);
5976   DECL_IS_NOVOPS (*node) = 1;
5977   return NULL_TREE;
5978 }
5979
5980 /* Handle a "deprecated" attribute; arguments as in
5981    struct attribute_spec.handler.  */
5982
5983 static tree
5984 handle_deprecated_attribute (tree *node, tree name,
5985                              tree ARG_UNUSED (args), int flags,
5986                              bool *no_add_attrs)
5987 {
5988   tree type = NULL_TREE;
5989   int warn = 0;
5990   tree what = NULL_TREE;
5991
5992   if (DECL_P (*node))
5993     {
5994       tree decl = *node;
5995       type = TREE_TYPE (decl);
5996
5997       if (TREE_CODE (decl) == TYPE_DECL
5998           || TREE_CODE (decl) == PARM_DECL
5999           || TREE_CODE (decl) == VAR_DECL
6000           || TREE_CODE (decl) == FUNCTION_DECL
6001           || TREE_CODE (decl) == FIELD_DECL)
6002         TREE_DEPRECATED (decl) = 1;
6003       else
6004         warn = 1;
6005     }
6006   else if (TYPE_P (*node))
6007     {
6008       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6009         *node = build_variant_type_copy (*node);
6010       TREE_DEPRECATED (*node) = 1;
6011       type = *node;
6012     }
6013   else
6014     warn = 1;
6015
6016   if (warn)
6017     {
6018       *no_add_attrs = true;
6019       if (type && TYPE_NAME (type))
6020         {
6021           if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
6022             what = TYPE_NAME (*node);
6023           else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
6024                    && DECL_NAME (TYPE_NAME (type)))
6025             what = DECL_NAME (TYPE_NAME (type));
6026         }
6027       if (what)
6028         warning (OPT_Wattributes, "%qE attribute ignored for %qE", name, what);
6029       else
6030         warning (OPT_Wattributes, "%qE attribute ignored", name);
6031     }
6032
6033   return NULL_TREE;
6034 }
6035
6036 /* Handle a "vector_size" attribute; arguments as in
6037    struct attribute_spec.handler.  */
6038
6039 static tree
6040 handle_vector_size_attribute (tree *node, tree name, tree args,
6041                               int ARG_UNUSED (flags),
6042                               bool *no_add_attrs)
6043 {
6044   unsigned HOST_WIDE_INT vecsize, nunits;
6045   enum machine_mode orig_mode;
6046   tree type = *node, new_type, size;
6047
6048   *no_add_attrs = true;
6049
6050   size = TREE_VALUE (args);
6051
6052   if (!host_integerp (size, 1))
6053     {
6054       warning (OPT_Wattributes, "%qE attribute ignored", name);
6055       return NULL_TREE;
6056     }
6057
6058   /* Get the vector size (in bytes).  */
6059   vecsize = tree_low_cst (size, 1);
6060
6061   /* We need to provide for vector pointers, vector arrays, and
6062      functions returning vectors.  For example:
6063
6064        __attribute__((vector_size(16))) short *foo;
6065
6066      In this case, the mode is SI, but the type being modified is
6067      HI, so we need to look further.  */
6068
6069   while (POINTER_TYPE_P (type)
6070          || TREE_CODE (type) == FUNCTION_TYPE
6071          || TREE_CODE (type) == METHOD_TYPE
6072          || TREE_CODE (type) == ARRAY_TYPE)
6073     type = TREE_TYPE (type);
6074
6075   /* Get the mode of the type being modified.  */
6076   orig_mode = TYPE_MODE (type);
6077
6078   if (TREE_CODE (type) == RECORD_TYPE
6079       || TREE_CODE (type) == UNION_TYPE
6080       || TREE_CODE (type) == VECTOR_TYPE
6081       || (!SCALAR_FLOAT_MODE_P (orig_mode)
6082           && GET_MODE_CLASS (orig_mode) != MODE_INT
6083           && !ALL_SCALAR_FIXED_POINT_MODE_P (orig_mode))
6084       || !host_integerp (TYPE_SIZE_UNIT (type), 1))
6085     {
6086       error ("invalid vector type for attribute %qE", name);
6087       return NULL_TREE;
6088     }
6089
6090   if (vecsize % tree_low_cst (TYPE_SIZE_UNIT (type), 1))
6091     {
6092       error ("vector size not an integral multiple of component size");
6093       return NULL;
6094     }
6095
6096   if (vecsize == 0)
6097     {
6098       error ("zero vector size");
6099       return NULL;
6100     }
6101
6102   /* Calculate how many units fit in the vector.  */
6103   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
6104   if (nunits & (nunits - 1))
6105     {
6106       error ("number of components of the vector not a power of two");
6107       return NULL_TREE;
6108     }
6109
6110   new_type = build_vector_type (type, nunits);
6111
6112   /* Build back pointers if needed.  */
6113   *node = reconstruct_complex_type (*node, new_type);
6114
6115   return NULL_TREE;
6116 }
6117
6118 /* Handle the "nonnull" attribute.  */
6119 static tree
6120 handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
6121                           tree args, int ARG_UNUSED (flags),
6122                           bool *no_add_attrs)
6123 {
6124   tree type = *node;
6125   unsigned HOST_WIDE_INT attr_arg_num;
6126
6127   /* If no arguments are specified, all pointer arguments should be
6128      non-null.  Verify a full prototype is given so that the arguments
6129      will have the correct types when we actually check them later.  */
6130   if (!args)
6131     {
6132       if (!TYPE_ARG_TYPES (type))
6133         {
6134           error ("nonnull attribute without arguments on a non-prototype");
6135           *no_add_attrs = true;
6136         }
6137       return NULL_TREE;
6138     }
6139
6140   /* Argument list specified.  Verify that each argument number references
6141      a pointer argument.  */
6142   for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
6143     {
6144       tree argument;
6145       unsigned HOST_WIDE_INT arg_num = 0, ck_num;
6146
6147       if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
6148         {
6149           error ("nonnull argument has invalid operand number (argument %lu)",
6150                  (unsigned long) attr_arg_num);
6151           *no_add_attrs = true;
6152           return NULL_TREE;
6153         }
6154
6155       argument = TYPE_ARG_TYPES (type);
6156       if (argument)
6157         {
6158           for (ck_num = 1; ; ck_num++)
6159             {
6160               if (!argument || ck_num == arg_num)
6161                 break;
6162               argument = TREE_CHAIN (argument);
6163             }
6164
6165           if (!argument
6166               || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
6167             {
6168               error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)",
6169                      (unsigned long) attr_arg_num, (unsigned long) arg_num);
6170               *no_add_attrs = true;
6171               return NULL_TREE;
6172             }
6173
6174           if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
6175             {
6176               error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)",
6177                    (unsigned long) attr_arg_num, (unsigned long) arg_num);
6178               *no_add_attrs = true;
6179               return NULL_TREE;
6180             }
6181         }
6182     }
6183
6184   return NULL_TREE;
6185 }
6186
6187 /* Check the argument list of a function call for null in argument slots
6188    that are marked as requiring a non-null pointer argument.  The NARGS
6189    arguments are passed in the array ARGARRAY.
6190 */
6191
6192 static void
6193 check_function_nonnull (tree attrs, int nargs, tree *argarray)
6194 {
6195   tree a, args;
6196   int i;
6197
6198   for (a = attrs; a; a = TREE_CHAIN (a))
6199     {
6200       if (is_attribute_p ("nonnull", TREE_PURPOSE (a)))
6201         {
6202           args = TREE_VALUE (a);
6203
6204           /* Walk the argument list.  If we encounter an argument number we
6205              should check for non-null, do it.  If the attribute has no args,
6206              then every pointer argument is checked (in which case the check
6207              for pointer type is done in check_nonnull_arg).  */
6208           for (i = 0; i < nargs; i++)
6209             {
6210               if (!args || nonnull_check_p (args, i + 1))
6211                 check_function_arguments_recurse (check_nonnull_arg, NULL,
6212                                                   argarray[i],
6213                                                   i + 1);
6214             }
6215         }
6216     }
6217 }
6218
6219 /* Check that the Nth argument of a function call (counting backwards
6220    from the end) is a (pointer)0.  The NARGS arguments are passed in the
6221    array ARGARRAY.  */
6222
6223 static void
6224 check_function_sentinel (tree attrs, int nargs, tree *argarray, tree typelist)
6225 {
6226   tree attr = lookup_attribute ("sentinel", attrs);
6227
6228   if (attr)
6229     {
6230       int len = 0;
6231       int pos = 0;
6232       tree sentinel;
6233
6234       /* Skip over the named arguments.  */
6235       while (typelist && len < nargs)
6236         {
6237           typelist = TREE_CHAIN (typelist);
6238           len++;
6239         }
6240
6241       if (TREE_VALUE (attr))
6242         {
6243           tree p = TREE_VALUE (TREE_VALUE (attr));
6244           pos = TREE_INT_CST_LOW (p);
6245         }
6246
6247       /* The sentinel must be one of the varargs, i.e.
6248          in position >= the number of fixed arguments.  */
6249       if ((nargs - 1 - pos) < len)
6250         {
6251           warning (OPT_Wformat,
6252                    "not enough variable arguments to fit a sentinel");
6253           return;
6254         }
6255
6256       /* Validate the sentinel.  */
6257       sentinel = argarray[nargs - 1 - pos];
6258       if ((!POINTER_TYPE_P (TREE_TYPE (sentinel))
6259            || !integer_zerop (sentinel))
6260           /* Although __null (in C++) is only an integer we allow it
6261              nevertheless, as we are guaranteed that it's exactly
6262              as wide as a pointer, and we don't want to force
6263              users to cast the NULL they have written there.
6264              We warn with -Wstrict-null-sentinel, though.  */
6265           && (warn_strict_null_sentinel || null_node != sentinel))
6266         warning (OPT_Wformat, "missing sentinel in function call");
6267     }
6268 }
6269
6270 /* Helper for check_function_nonnull; given a list of operands which
6271    must be non-null in ARGS, determine if operand PARAM_NUM should be
6272    checked.  */
6273
6274 static bool
6275 nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num)
6276 {
6277   unsigned HOST_WIDE_INT arg_num = 0;
6278
6279   for (; args; args = TREE_CHAIN (args))
6280     {
6281       bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num);
6282
6283       gcc_assert (found);
6284
6285       if (arg_num == param_num)
6286         return true;
6287     }
6288   return false;
6289 }
6290
6291 /* Check that the function argument PARAM (which is operand number
6292    PARAM_NUM) is non-null.  This is called by check_function_nonnull
6293    via check_function_arguments_recurse.  */
6294
6295 static void
6296 check_nonnull_arg (void * ARG_UNUSED (ctx), tree param,
6297                    unsigned HOST_WIDE_INT param_num)
6298 {
6299   /* Just skip checking the argument if it's not a pointer.  This can
6300      happen if the "nonnull" attribute was given without an operand
6301      list (which means to check every pointer argument).  */
6302
6303   if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE)
6304     return;
6305
6306   if (integer_zerop (param))
6307     warning (OPT_Wnonnull, "null argument where non-null required "
6308              "(argument %lu)", (unsigned long) param_num);
6309 }
6310
6311 /* Helper for nonnull attribute handling; fetch the operand number
6312    from the attribute argument list.  */
6313
6314 static bool
6315 get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp)
6316 {
6317   /* Verify the arg number is a constant.  */
6318   if (TREE_CODE (arg_num_expr) != INTEGER_CST
6319       || TREE_INT_CST_HIGH (arg_num_expr) != 0)
6320     return false;
6321
6322   *valp = TREE_INT_CST_LOW (arg_num_expr);
6323   return true;
6324 }
6325
6326 /* Handle a "nothrow" attribute; arguments as in
6327    struct attribute_spec.handler.  */
6328
6329 static tree
6330 handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6331                           int ARG_UNUSED (flags), bool *no_add_attrs)
6332 {
6333   if (TREE_CODE (*node) == FUNCTION_DECL)
6334     TREE_NOTHROW (*node) = 1;
6335   /* ??? TODO: Support types.  */
6336   else
6337     {
6338       warning (OPT_Wattributes, "%qE attribute ignored", name);
6339       *no_add_attrs = true;
6340     }
6341
6342   return NULL_TREE;
6343 }
6344
6345 /* Handle a "cleanup" attribute; arguments as in
6346    struct attribute_spec.handler.  */
6347
6348 static tree
6349 handle_cleanup_attribute (tree *node, tree name, tree args,
6350                           int ARG_UNUSED (flags), bool *no_add_attrs)
6351 {
6352   tree decl = *node;
6353   tree cleanup_id, cleanup_decl;
6354
6355   /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do
6356      for global destructors in C++.  This requires infrastructure that
6357      we don't have generically at the moment.  It's also not a feature
6358      we'd be missing too much, since we do have attribute constructor.  */
6359   if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl))
6360     {
6361       warning (OPT_Wattributes, "%qE attribute ignored", name);
6362       *no_add_attrs = true;
6363       return NULL_TREE;
6364     }
6365
6366   /* Verify that the argument is a function in scope.  */
6367   /* ??? We could support pointers to functions here as well, if
6368      that was considered desirable.  */
6369   cleanup_id = TREE_VALUE (args);
6370   if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE)
6371     {
6372       error ("cleanup argument not an identifier");
6373       *no_add_attrs = true;
6374       return NULL_TREE;
6375     }
6376   cleanup_decl = lookup_name (cleanup_id);
6377   if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL)
6378     {
6379       error ("cleanup argument not a function");
6380       *no_add_attrs = true;
6381       return NULL_TREE;
6382     }
6383
6384   /* That the function has proper type is checked with the
6385      eventual call to build_function_call.  */
6386
6387   return NULL_TREE;
6388 }
6389
6390 /* Handle a "warn_unused_result" attribute.  No special handling.  */
6391
6392 static tree
6393 handle_warn_unused_result_attribute (tree *node, tree name,
6394                                tree ARG_UNUSED (args),
6395                                int ARG_UNUSED (flags), bool *no_add_attrs)
6396 {
6397   /* Ignore the attribute for functions not returning any value.  */
6398   if (VOID_TYPE_P (TREE_TYPE (*node)))
6399     {
6400       warning (OPT_Wattributes, "%qE attribute ignored", name);
6401       *no_add_attrs = true;
6402     }
6403
6404   return NULL_TREE;
6405 }
6406
6407 /* Handle a "sentinel" attribute.  */
6408
6409 static tree
6410 handle_sentinel_attribute (tree *node, tree name, tree args,
6411                            int ARG_UNUSED (flags), bool *no_add_attrs)
6412 {
6413   tree params = TYPE_ARG_TYPES (*node);
6414
6415   if (!params)
6416     {
6417       warning (OPT_Wattributes,
6418                "%qE attribute requires prototypes with named arguments", name);
6419       *no_add_attrs = true;
6420     }
6421   else
6422     {
6423       while (TREE_CHAIN (params))
6424         params = TREE_CHAIN (params);
6425
6426       if (VOID_TYPE_P (TREE_VALUE (params)))
6427         {
6428           warning (OPT_Wattributes,
6429                    "%qE attribute only applies to variadic functions", name);
6430           *no_add_attrs = true;
6431         }
6432     }
6433
6434   if (args)
6435     {
6436       tree position = TREE_VALUE (args);
6437
6438       if (TREE_CODE (position) != INTEGER_CST)
6439         {
6440           warning (OPT_Wattributes,
6441                    "requested position is not an integer constant");
6442           *no_add_attrs = true;
6443         }
6444       else
6445         {
6446           if (tree_int_cst_lt (position, integer_zero_node))
6447             {
6448               warning (OPT_Wattributes,
6449                        "requested position is less than zero");
6450               *no_add_attrs = true;
6451             }
6452         }
6453     }
6454
6455   return NULL_TREE;
6456 }
6457
6458 /* Handle a "type_generic" attribute.  */
6459
6460 static tree
6461 handle_type_generic_attribute (tree *node, tree ARG_UNUSED (name),
6462                                tree ARG_UNUSED (args), int ARG_UNUSED (flags),
6463                                bool * ARG_UNUSED (no_add_attrs))
6464 {
6465   /* Ensure we have a function type, with no arguments.  */
6466   gcc_assert (TREE_CODE (*node) == FUNCTION_TYPE && ! TYPE_ARG_TYPES (*node));
6467
6468   return NULL_TREE;
6469 }
6470 \f
6471 /* Check for valid arguments being passed to a function.
6472    ATTRS is a list of attributes.  There are NARGS arguments in the array
6473    ARGARRAY.  TYPELIST is the list of argument types for the function.
6474  */
6475 void
6476 check_function_arguments (tree attrs, int nargs, tree *argarray, tree typelist)
6477 {
6478   /* Check for null being passed in a pointer argument that must be
6479      non-null.  We also need to do this if format checking is enabled.  */
6480
6481   if (warn_nonnull)
6482     check_function_nonnull (attrs, nargs, argarray);
6483
6484   /* Check for errors in format strings.  */
6485
6486   if (warn_format || warn_missing_format_attribute)
6487     check_function_format (attrs, nargs, argarray);
6488
6489   if (warn_format)
6490     check_function_sentinel (attrs, nargs, argarray, typelist);
6491 }
6492
6493 /* Generic argument checking recursion routine.  PARAM is the argument to
6494    be checked.  PARAM_NUM is the number of the argument.  CALLBACK is invoked
6495    once the argument is resolved.  CTX is context for the callback.  */
6496 void
6497 check_function_arguments_recurse (void (*callback)
6498                                   (void *, tree, unsigned HOST_WIDE_INT),
6499                                   void *ctx, tree param,
6500                                   unsigned HOST_WIDE_INT param_num)
6501 {
6502   if ((TREE_CODE (param) == NOP_EXPR || TREE_CODE (param) == CONVERT_EXPR)
6503       && (TYPE_PRECISION (TREE_TYPE (param))
6504           == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (param, 0)))))
6505     {
6506       /* Strip coercion.  */
6507       check_function_arguments_recurse (callback, ctx,
6508                                         TREE_OPERAND (param, 0), param_num);
6509       return;
6510     }
6511
6512   if (TREE_CODE (param) == CALL_EXPR)
6513     {
6514       tree type = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (param)));
6515       tree attrs;
6516       bool found_format_arg = false;
6517
6518       /* See if this is a call to a known internationalization function
6519          that modifies a format arg.  Such a function may have multiple
6520          format_arg attributes (for example, ngettext).  */
6521
6522       for (attrs = TYPE_ATTRIBUTES (type);
6523            attrs;
6524            attrs = TREE_CHAIN (attrs))
6525         if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs)))
6526           {
6527             tree inner_arg;
6528             tree format_num_expr;
6529             int format_num;
6530             int i;
6531             call_expr_arg_iterator iter;
6532
6533             /* Extract the argument number, which was previously checked
6534                to be valid.  */
6535             format_num_expr = TREE_VALUE (TREE_VALUE (attrs));
6536
6537             gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST
6538                         && !TREE_INT_CST_HIGH (format_num_expr));
6539
6540             format_num = TREE_INT_CST_LOW (format_num_expr);
6541
6542             for (inner_arg = first_call_expr_arg (param, &iter), i = 1;
6543                  inner_arg != 0;
6544                  inner_arg = next_call_expr_arg (&iter), i++)
6545               if (i == format_num)
6546                 {
6547                   check_function_arguments_recurse (callback, ctx,
6548                                                     inner_arg, param_num);
6549                   found_format_arg = true;
6550                   break;
6551                 }
6552           }
6553
6554       /* If we found a format_arg attribute and did a recursive check,
6555          we are done with checking this argument.  Otherwise, we continue
6556          and this will be considered a non-literal.  */
6557       if (found_format_arg)
6558         return;
6559     }
6560
6561   if (TREE_CODE (param) == COND_EXPR)
6562     {
6563       /* Check both halves of the conditional expression.  */
6564       check_function_arguments_recurse (callback, ctx,
6565                                         TREE_OPERAND (param, 1), param_num);
6566       check_function_arguments_recurse (callback, ctx,
6567                                         TREE_OPERAND (param, 2), param_num);
6568       return;
6569     }
6570
6571   (*callback) (ctx, param, param_num);
6572 }
6573
6574 /* Function to help qsort sort FIELD_DECLs by name order.  */
6575
6576 int
6577 field_decl_cmp (const void *x_p, const void *y_p)
6578 {
6579   const tree *const x = (const tree *const) x_p;
6580   const tree *const y = (const tree *const) y_p;
6581
6582   if (DECL_NAME (*x) == DECL_NAME (*y))
6583     /* A nontype is "greater" than a type.  */
6584     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
6585   if (DECL_NAME (*x) == NULL_TREE)
6586     return -1;
6587   if (DECL_NAME (*y) == NULL_TREE)
6588     return 1;
6589   if (DECL_NAME (*x) < DECL_NAME (*y))
6590     return -1;
6591   return 1;
6592 }
6593
6594 static struct {
6595   gt_pointer_operator new_value;
6596   void *cookie;
6597 } resort_data;
6598
6599 /* This routine compares two fields like field_decl_cmp but using the
6600 pointer operator in resort_data.  */
6601
6602 static int
6603 resort_field_decl_cmp (const void *x_p, const void *y_p)
6604 {
6605   const tree *const x = (const tree *const) x_p;
6606   const tree *const y = (const tree *const) y_p;
6607
6608   if (DECL_NAME (*x) == DECL_NAME (*y))
6609     /* A nontype is "greater" than a type.  */
6610     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
6611   if (DECL_NAME (*x) == NULL_TREE)
6612     return -1;
6613   if (DECL_NAME (*y) == NULL_TREE)
6614     return 1;
6615   {
6616     tree d1 = DECL_NAME (*x);
6617     tree d2 = DECL_NAME (*y);
6618     resort_data.new_value (&d1, resort_data.cookie);
6619     resort_data.new_value (&d2, resort_data.cookie);
6620     if (d1 < d2)
6621       return -1;
6622   }
6623   return 1;
6624 }
6625
6626 /* Resort DECL_SORTED_FIELDS because pointers have been reordered.  */
6627
6628 void
6629 resort_sorted_fields (void *obj,
6630                       void * ARG_UNUSED (orig_obj),
6631                       gt_pointer_operator new_value,
6632                       void *cookie)
6633 {
6634   struct sorted_fields_type *sf = (struct sorted_fields_type *) obj;
6635   resort_data.new_value = new_value;
6636   resort_data.cookie = cookie;
6637   qsort (&sf->elts[0], sf->len, sizeof (tree),
6638          resort_field_decl_cmp);
6639 }
6640
6641 /* Subroutine of c_parse_error.
6642    Return the result of concatenating LHS and RHS. RHS is really
6643    a string literal, its first character is indicated by RHS_START and
6644    RHS_SIZE is its length (including the terminating NUL character).
6645
6646    The caller is responsible for deleting the returned pointer.  */
6647
6648 static char *
6649 catenate_strings (const char *lhs, const char *rhs_start, int rhs_size)
6650 {
6651   const int lhs_size = strlen (lhs);
6652   char *result = XNEWVEC (char, lhs_size + rhs_size);
6653   strncpy (result, lhs, lhs_size);
6654   strncpy (result + lhs_size, rhs_start, rhs_size);
6655   return result;
6656 }
6657
6658 /* Issue the error given by GMSGID, indicating that it occurred before
6659    TOKEN, which had the associated VALUE.  */
6660
6661 void
6662 c_parse_error (const char *gmsgid, enum cpp_ttype token, tree value)
6663 {
6664 #define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2))
6665
6666   char *message = NULL;
6667
6668   if (token == CPP_EOF)
6669     message = catenate_messages (gmsgid, " at end of input");
6670   else if (token == CPP_CHAR || token == CPP_WCHAR)
6671     {
6672       unsigned int val = TREE_INT_CST_LOW (value);
6673       const char *const ell = (token == CPP_CHAR) ? "" : "L";
6674       if (val <= UCHAR_MAX && ISGRAPH (val))
6675         message = catenate_messages (gmsgid, " before %s'%c'");
6676       else
6677         message = catenate_messages (gmsgid, " before %s'\\x%x'");
6678
6679       error (message, ell, val);
6680       free (message);
6681       message = NULL;
6682     }
6683   else if (token == CPP_STRING || token == CPP_WSTRING)
6684     message = catenate_messages (gmsgid, " before string constant");
6685   else if (token == CPP_NUMBER)
6686     message = catenate_messages (gmsgid, " before numeric constant");
6687   else if (token == CPP_NAME)
6688     {
6689       message = catenate_messages (gmsgid, " before %qE");
6690       error (message, value);
6691       free (message);
6692       message = NULL;
6693     }
6694   else if (token == CPP_PRAGMA)
6695     message = catenate_messages (gmsgid, " before %<#pragma%>");
6696   else if (token == CPP_PRAGMA_EOL)
6697     message = catenate_messages (gmsgid, " before end of line");
6698   else if (token < N_TTYPES)
6699     {
6700       message = catenate_messages (gmsgid, " before %qs token");
6701       error (message, cpp_type2name (token));
6702       free (message);
6703       message = NULL;
6704     }
6705   else
6706     error (gmsgid);
6707
6708   if (message)
6709     {
6710       error (message);
6711       free (message);
6712     }
6713 #undef catenate_messages
6714 }
6715
6716 /* Walk a gimplified function and warn for functions whose return value is
6717    ignored and attribute((warn_unused_result)) is set.  This is done before
6718    inlining, so we don't have to worry about that.  */
6719
6720 void
6721 c_warn_unused_result (tree *top_p)
6722 {
6723   tree t = *top_p;
6724   tree_stmt_iterator i;
6725   tree fdecl, ftype;
6726
6727   switch (TREE_CODE (t))
6728     {
6729     case STATEMENT_LIST:
6730       for (i = tsi_start (*top_p); !tsi_end_p (i); tsi_next (&i))
6731         c_warn_unused_result (tsi_stmt_ptr (i));
6732       break;
6733
6734     case COND_EXPR:
6735       c_warn_unused_result (&COND_EXPR_THEN (t));
6736       c_warn_unused_result (&COND_EXPR_ELSE (t));
6737       break;
6738     case BIND_EXPR:
6739       c_warn_unused_result (&BIND_EXPR_BODY (t));
6740       break;
6741     case TRY_FINALLY_EXPR:
6742     case TRY_CATCH_EXPR:
6743       c_warn_unused_result (&TREE_OPERAND (t, 0));
6744       c_warn_unused_result (&TREE_OPERAND (t, 1));
6745       break;
6746     case CATCH_EXPR:
6747       c_warn_unused_result (&CATCH_BODY (t));
6748       break;
6749     case EH_FILTER_EXPR:
6750       c_warn_unused_result (&EH_FILTER_FAILURE (t));
6751       break;
6752
6753     case CALL_EXPR:
6754       if (TREE_USED (t))
6755         break;
6756
6757       /* This is a naked call, as opposed to a CALL_EXPR nested inside
6758          a MODIFY_EXPR.  All calls whose value is ignored should be
6759          represented like this.  Look for the attribute.  */
6760       fdecl = get_callee_fndecl (t);
6761       if (fdecl)
6762         ftype = TREE_TYPE (fdecl);
6763       else
6764         {
6765           ftype = TREE_TYPE (CALL_EXPR_FN (t));
6766           /* Look past pointer-to-function to the function type itself.  */
6767           ftype = TREE_TYPE (ftype);
6768         }
6769
6770       if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype)))
6771         {
6772           if (fdecl)
6773             warning (0, "%Hignoring return value of %qD, "
6774                      "declared with attribute warn_unused_result",
6775                      EXPR_LOCUS (t), fdecl);
6776           else
6777             warning (0, "%Hignoring return value of function "
6778                      "declared with attribute warn_unused_result",
6779                      EXPR_LOCUS (t));
6780         }
6781       break;
6782
6783     default:
6784       /* Not a container, not a call, or a call whose value is used.  */
6785       break;
6786     }
6787 }
6788
6789 /* Convert a character from the host to the target execution character
6790    set.  cpplib handles this, mostly.  */
6791
6792 HOST_WIDE_INT
6793 c_common_to_target_charset (HOST_WIDE_INT c)
6794 {
6795   /* Character constants in GCC proper are sign-extended under -fsigned-char,
6796      zero-extended under -fno-signed-char.  cpplib insists that characters
6797      and character constants are always unsigned.  Hence we must convert
6798      back and forth.  */
6799   cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1);
6800
6801   uc = cpp_host_to_exec_charset (parse_in, uc);
6802
6803   if (flag_signed_char)
6804     return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE)
6805                                >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE);
6806   else
6807     return uc;
6808 }
6809
6810 /* Build the result of __builtin_offsetof.  EXPR is a nested sequence of
6811    component references, with STOP_REF, or alternatively an INDIRECT_REF of
6812    NULL, at the bottom; much like the traditional rendering of offsetof as a
6813    macro.  Returns the folded and properly cast result.  */
6814
6815 static tree
6816 fold_offsetof_1 (tree expr, tree stop_ref)
6817 {
6818   enum tree_code code = PLUS_EXPR;
6819   tree base, off, t;
6820
6821   if (expr == stop_ref && TREE_CODE (expr) != ERROR_MARK)
6822     return size_zero_node;
6823
6824   switch (TREE_CODE (expr))
6825     {
6826     case ERROR_MARK:
6827       return expr;
6828
6829     case VAR_DECL:
6830       error ("cannot apply %<offsetof%> to static data member %qD", expr);
6831       return error_mark_node;
6832
6833     case CALL_EXPR:
6834       error ("cannot apply %<offsetof%> when %<operator[]%> is overloaded");
6835       return error_mark_node;
6836
6837     case INTEGER_CST:
6838       gcc_assert (integer_zerop (expr));
6839       return size_zero_node;
6840
6841     case NOP_EXPR:
6842     case INDIRECT_REF:
6843       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
6844       gcc_assert (base == error_mark_node || base == size_zero_node);
6845       return base;
6846
6847     case COMPONENT_REF:
6848       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
6849       if (base == error_mark_node)
6850         return base;
6851
6852       t = TREE_OPERAND (expr, 1);
6853       if (DECL_C_BIT_FIELD (t))
6854         {
6855           error ("attempt to take address of bit-field structure "
6856                  "member %qD", t);
6857           return error_mark_node;
6858         }
6859       off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t),
6860                         size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t), 1)
6861                                   / BITS_PER_UNIT));
6862       break;
6863
6864     case ARRAY_REF:
6865       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
6866       if (base == error_mark_node)
6867         return base;
6868
6869       t = TREE_OPERAND (expr, 1);
6870       if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0)
6871         {
6872           code = MINUS_EXPR;
6873           t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t);
6874         }
6875       t = convert (sizetype, t);
6876       off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
6877       break;
6878
6879     case COMPOUND_EXPR:
6880       /* Handle static members of volatile structs.  */
6881       t = TREE_OPERAND (expr, 1);
6882       gcc_assert (TREE_CODE (t) == VAR_DECL);
6883       return fold_offsetof_1 (t, stop_ref);
6884
6885     default:
6886       gcc_unreachable ();
6887     }
6888
6889   return size_binop (code, base, off);
6890 }
6891
6892 tree
6893 fold_offsetof (tree expr, tree stop_ref)
6894 {
6895   /* Convert back from the internal sizetype to size_t.  */
6896   return convert (size_type_node, fold_offsetof_1 (expr, stop_ref));
6897 }
6898
6899 /* Print an error message for an invalid lvalue.  USE says
6900    how the lvalue is being used and so selects the error message.  */
6901
6902 void
6903 lvalue_error (enum lvalue_use use)
6904 {
6905   switch (use)
6906     {
6907     case lv_assign:
6908       error ("lvalue required as left operand of assignment");
6909       break;
6910     case lv_increment:
6911       error ("lvalue required as increment operand");
6912       break;
6913     case lv_decrement:
6914       error ("lvalue required as decrement operand");
6915       break;
6916     case lv_addressof:
6917       error ("lvalue required as unary %<&%> operand");
6918       break;
6919     case lv_asm:
6920       error ("lvalue required in asm statement");
6921       break;
6922     default:
6923       gcc_unreachable ();
6924     }
6925 }
6926 \f
6927 /* *PTYPE is an incomplete array.  Complete it with a domain based on
6928    INITIAL_VALUE.  If INITIAL_VALUE is not present, use 1 if DO_DEFAULT
6929    is true.  Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered,
6930    2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty.  */
6931
6932 int
6933 complete_array_type (tree *ptype, tree initial_value, bool do_default)
6934 {
6935   tree maxindex, type, main_type, elt, unqual_elt;
6936   int failure = 0, quals;
6937   hashval_t hashcode = 0;
6938
6939   maxindex = size_zero_node;
6940   if (initial_value)
6941     {
6942       if (TREE_CODE (initial_value) == STRING_CST)
6943         {
6944           int eltsize
6945             = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value)));
6946           maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1);
6947         }
6948       else if (TREE_CODE (initial_value) == CONSTRUCTOR)
6949         {
6950           VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (initial_value);
6951
6952           if (VEC_empty (constructor_elt, v))
6953             {
6954               if (pedantic)
6955                 failure = 3;
6956               maxindex = integer_minus_one_node;
6957             }
6958           else
6959             {
6960               tree curindex;
6961               unsigned HOST_WIDE_INT cnt;
6962               constructor_elt *ce;
6963
6964               if (VEC_index (constructor_elt, v, 0)->index)
6965                 maxindex = fold_convert (sizetype,
6966                                          VEC_index (constructor_elt,
6967                                                     v, 0)->index);
6968               curindex = maxindex;
6969
6970               for (cnt = 1;
6971                    VEC_iterate (constructor_elt, v, cnt, ce);
6972                    cnt++)
6973                 {
6974                   if (ce->index)
6975                     curindex = fold_convert (sizetype, ce->index);
6976                   else
6977                     curindex = size_binop (PLUS_EXPR, curindex, size_one_node);
6978
6979                   if (tree_int_cst_lt (maxindex, curindex))
6980                     maxindex = curindex;
6981                 }
6982             }
6983         }
6984       else
6985         {
6986           /* Make an error message unless that happened already.  */
6987           if (initial_value != error_mark_node)
6988             failure = 1;
6989         }
6990     }
6991   else
6992     {
6993       failure = 2;
6994       if (!do_default)
6995         return failure;
6996     }
6997
6998   type = *ptype;
6999   elt = TREE_TYPE (type);
7000   quals = TYPE_QUALS (strip_array_types (elt));
7001   if (quals == 0)
7002     unqual_elt = elt;
7003   else
7004     unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
7005
7006   /* Using build_distinct_type_copy and modifying things afterward instead
7007      of using build_array_type to create a new type preserves all of the
7008      TYPE_LANG_FLAG_? bits that the front end may have set.  */
7009   main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
7010   TREE_TYPE (main_type) = unqual_elt;
7011   TYPE_DOMAIN (main_type) = build_index_type (maxindex);
7012   layout_type (main_type);
7013
7014   /* Make sure we have the canonical MAIN_TYPE. */
7015   hashcode = iterative_hash_object (TYPE_HASH (unqual_elt), hashcode);
7016   hashcode = iterative_hash_object (TYPE_HASH (TYPE_DOMAIN (main_type)),
7017                                     hashcode);
7018   main_type = type_hash_canon (hashcode, main_type);
7019
7020   if (quals == 0)
7021     type = main_type;
7022   else
7023     type = c_build_qualified_type (main_type, quals);
7024
7025   *ptype = type;
7026   return failure;
7027 }
7028
7029 \f
7030 /* Used to help initialize the builtin-types.def table.  When a type of
7031    the correct size doesn't exist, use error_mark_node instead of NULL.
7032    The later results in segfaults even when a decl using the type doesn't
7033    get invoked.  */
7034
7035 tree
7036 builtin_type_for_size (int size, bool unsignedp)
7037 {
7038   tree type = lang_hooks.types.type_for_size (size, unsignedp);
7039   return type ? type : error_mark_node;
7040 }
7041
7042 /* A helper function for resolve_overloaded_builtin in resolving the
7043    overloaded __sync_ builtins.  Returns a positive power of 2 if the
7044    first operand of PARAMS is a pointer to a supported data type.
7045    Returns 0 if an error is encountered.  */
7046
7047 static int
7048 sync_resolve_size (tree function, tree params)
7049 {
7050   tree type;
7051   int size;
7052
7053   if (params == NULL)
7054     {
7055       error ("too few arguments to function %qE", function);
7056       return 0;
7057     }
7058
7059   type = TREE_TYPE (TREE_VALUE (params));
7060   if (TREE_CODE (type) != POINTER_TYPE)
7061     goto incompatible;
7062
7063   type = TREE_TYPE (type);
7064   if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
7065     goto incompatible;
7066
7067   size = tree_low_cst (TYPE_SIZE_UNIT (type), 1);
7068   if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16)
7069     return size;
7070
7071  incompatible:
7072   error ("incompatible type for argument %d of %qE", 1, function);
7073   return 0;
7074 }
7075
7076 /* A helper function for resolve_overloaded_builtin.  Adds casts to
7077    PARAMS to make arguments match up with those of FUNCTION.  Drops
7078    the variadic arguments at the end.  Returns false if some error
7079    was encountered; true on success.  */
7080
7081 static bool
7082 sync_resolve_params (tree orig_function, tree function, tree params)
7083 {
7084   tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (function));
7085   tree ptype;
7086   int number;
7087
7088   /* We've declared the implementation functions to use "volatile void *"
7089      as the pointer parameter, so we shouldn't get any complaints from the
7090      call to check_function_arguments what ever type the user used.  */
7091   arg_types = TREE_CHAIN (arg_types);
7092   ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params)));
7093   number = 2;
7094
7095   /* For the rest of the values, we need to cast these to FTYPE, so that we
7096      don't get warnings for passing pointer types, etc.  */
7097   while (arg_types != void_list_node)
7098     {
7099       tree val;
7100
7101       params = TREE_CHAIN (params);
7102       if (params == NULL)
7103         {
7104           error ("too few arguments to function %qE", orig_function);
7105           return false;
7106         }
7107
7108       /* ??? Ideally for the first conversion we'd use convert_for_assignment
7109          so that we get warnings for anything that doesn't match the pointer
7110          type.  This isn't portable across the C and C++ front ends atm.  */
7111       val = TREE_VALUE (params);
7112       val = convert (ptype, val);
7113       val = convert (TREE_VALUE (arg_types), val);
7114       TREE_VALUE (params) = val;
7115
7116       arg_types = TREE_CHAIN (arg_types);
7117       number++;
7118     }
7119
7120   /* The definition of these primitives is variadic, with the remaining
7121      being "an optional list of variables protected by the memory barrier".
7122      No clue what that's supposed to mean, precisely, but we consider all
7123      call-clobbered variables to be protected so we're safe.  */
7124   TREE_CHAIN (params) = NULL;
7125
7126   return true;
7127 }
7128
7129 /* A helper function for resolve_overloaded_builtin.  Adds a cast to
7130    RESULT to make it match the type of the first pointer argument in
7131    PARAMS.  */
7132
7133 static tree
7134 sync_resolve_return (tree params, tree result)
7135 {
7136   tree ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params)));
7137   ptype = TYPE_MAIN_VARIANT (ptype);
7138   return convert (ptype, result);
7139 }
7140
7141 /* Some builtin functions are placeholders for other expressions.  This
7142    function should be called immediately after parsing the call expression
7143    before surrounding code has committed to the type of the expression.
7144
7145    FUNCTION is the DECL that has been invoked; it is known to be a builtin.
7146    PARAMS is the argument list for the call.  The return value is non-null
7147    when expansion is complete, and null if normal processing should
7148    continue.  */
7149
7150 tree
7151 resolve_overloaded_builtin (tree function, tree params)
7152 {
7153   enum built_in_function orig_code = DECL_FUNCTION_CODE (function);
7154   switch (DECL_BUILT_IN_CLASS (function))
7155     {
7156     case BUILT_IN_NORMAL:
7157       break;
7158     case BUILT_IN_MD:
7159       if (targetm.resolve_overloaded_builtin)
7160         return targetm.resolve_overloaded_builtin (function, params);
7161       else
7162         return NULL_TREE;
7163     default:
7164       return NULL_TREE;
7165     }
7166
7167   /* Handle BUILT_IN_NORMAL here.  */
7168   switch (orig_code)
7169     {
7170     case BUILT_IN_FETCH_AND_ADD_N:
7171     case BUILT_IN_FETCH_AND_SUB_N:
7172     case BUILT_IN_FETCH_AND_OR_N:
7173     case BUILT_IN_FETCH_AND_AND_N:
7174     case BUILT_IN_FETCH_AND_XOR_N:
7175     case BUILT_IN_FETCH_AND_NAND_N:
7176     case BUILT_IN_ADD_AND_FETCH_N:
7177     case BUILT_IN_SUB_AND_FETCH_N:
7178     case BUILT_IN_OR_AND_FETCH_N:
7179     case BUILT_IN_AND_AND_FETCH_N:
7180     case BUILT_IN_XOR_AND_FETCH_N:
7181     case BUILT_IN_NAND_AND_FETCH_N:
7182     case BUILT_IN_BOOL_COMPARE_AND_SWAP_N:
7183     case BUILT_IN_VAL_COMPARE_AND_SWAP_N:
7184     case BUILT_IN_LOCK_TEST_AND_SET_N:
7185     case BUILT_IN_LOCK_RELEASE_N:
7186       {
7187         int n = sync_resolve_size (function, params);
7188         tree new_function, result;
7189
7190         if (n == 0)
7191           return error_mark_node;
7192
7193         new_function = built_in_decls[orig_code + exact_log2 (n) + 1];
7194         if (!sync_resolve_params (function, new_function, params))
7195           return error_mark_node;
7196
7197         result = build_function_call (new_function, params);
7198         if (orig_code != BUILT_IN_BOOL_COMPARE_AND_SWAP_N
7199             && orig_code != BUILT_IN_LOCK_RELEASE_N)
7200           result = sync_resolve_return (params, result);
7201
7202         return result;
7203       }
7204
7205     default:
7206       return NULL_TREE;
7207     }
7208 }
7209
7210 /* Ignoring their sign, return true if two scalar types are the same.  */
7211 bool
7212 same_scalar_type_ignoring_signedness (tree t1, tree t2)
7213 {
7214   enum tree_code c1 = TREE_CODE (t1), c2 = TREE_CODE (t2);
7215
7216   gcc_assert ((c1 == INTEGER_TYPE || c1 == REAL_TYPE || c1 == FIXED_POINT_TYPE)
7217               && (c2 == INTEGER_TYPE || c2 == REAL_TYPE
7218                   || c2 == FIXED_POINT_TYPE));
7219
7220   /* Equality works here because c_common_signed_type uses
7221      TYPE_MAIN_VARIANT.  */
7222   return c_common_signed_type (t1)
7223     == c_common_signed_type (t2);
7224 }
7225
7226 /* Check for missing format attributes on function pointers.  LTYPE is
7227    the new type or left-hand side type.  RTYPE is the old type or
7228    right-hand side type.  Returns TRUE if LTYPE is missing the desired
7229    attribute.  */
7230
7231 bool
7232 check_missing_format_attribute (tree ltype, tree rtype)
7233 {
7234   tree const ttr = TREE_TYPE (rtype), ttl = TREE_TYPE (ltype);
7235   tree ra;
7236
7237   for (ra = TYPE_ATTRIBUTES (ttr); ra; ra = TREE_CHAIN (ra))
7238     if (is_attribute_p ("format", TREE_PURPOSE (ra)))
7239       break;
7240   if (ra)
7241     {
7242       tree la;
7243       for (la = TYPE_ATTRIBUTES (ttl); la; la = TREE_CHAIN (la))
7244         if (is_attribute_p ("format", TREE_PURPOSE (la)))
7245           break;
7246       return !la;
7247     }
7248   else
7249     return false;
7250 }
7251
7252 /* Subscripting with type char is likely to lose on a machine where
7253    chars are signed.  So warn on any machine, but optionally.  Don't
7254    warn for unsigned char since that type is safe.  Don't warn for
7255    signed char because anyone who uses that must have done so
7256    deliberately. Furthermore, we reduce the false positive load by
7257    warning only for non-constant value of type char.  */
7258
7259 void
7260 warn_array_subscript_with_type_char (tree index)
7261 {
7262   if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node
7263       && TREE_CODE (index) != INTEGER_CST)
7264     warning (OPT_Wchar_subscripts, "array subscript has type %<char%>");
7265 }
7266
7267 /* Implement -Wparentheses for the unexpected C precedence rules, to
7268    cover cases like x + y << z which readers are likely to
7269    misinterpret.  We have seen an expression in which CODE is a binary
7270    operator used to combine expressions headed by CODE_LEFT and
7271    CODE_RIGHT.  CODE_LEFT and CODE_RIGHT may be ERROR_MARK, which
7272    means that that side of the expression was not formed using a
7273    binary operator, or it was enclosed in parentheses.  */
7274
7275 void
7276 warn_about_parentheses (enum tree_code code, enum tree_code code_left,
7277                         enum tree_code code_right)
7278 {
7279   if (!warn_parentheses)
7280     return;
7281
7282   if (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
7283     {
7284       if (code_left == PLUS_EXPR || code_left == MINUS_EXPR
7285           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7286         warning (OPT_Wparentheses,
7287                  "suggest parentheses around + or - inside shift");
7288     }
7289
7290   if (code == TRUTH_ORIF_EXPR)
7291     {
7292       if (code_left == TRUTH_ANDIF_EXPR
7293           || code_right == TRUTH_ANDIF_EXPR)
7294         warning (OPT_Wparentheses,
7295                  "suggest parentheses around && within ||");
7296     }
7297
7298   if (code == BIT_IOR_EXPR)
7299     {
7300       if (code_left == BIT_AND_EXPR || code_left == BIT_XOR_EXPR
7301           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
7302           || code_right == BIT_AND_EXPR || code_right == BIT_XOR_EXPR
7303           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7304         warning (OPT_Wparentheses,
7305                  "suggest parentheses around arithmetic in operand of |");
7306       /* Check cases like x|y==z */
7307       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7308           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7309         warning (OPT_Wparentheses,
7310                  "suggest parentheses around comparison in operand of |");
7311     }
7312
7313   if (code == BIT_XOR_EXPR)
7314     {
7315       if (code_left == BIT_AND_EXPR
7316           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
7317           || code_right == BIT_AND_EXPR
7318           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7319         warning (OPT_Wparentheses,
7320                  "suggest parentheses around arithmetic in operand of ^");
7321       /* Check cases like x^y==z */
7322       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7323           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7324         warning (OPT_Wparentheses,
7325                  "suggest parentheses around comparison in operand of ^");
7326     }
7327
7328   if (code == BIT_AND_EXPR)
7329     {
7330       if (code_left == PLUS_EXPR || code_left == MINUS_EXPR
7331           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7332         warning (OPT_Wparentheses,
7333                  "suggest parentheses around + or - in operand of &");
7334       /* Check cases like x&y==z */
7335       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7336           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7337         warning (OPT_Wparentheses,
7338                  "suggest parentheses around comparison in operand of &");
7339     }
7340
7341   if (code == EQ_EXPR || code == NE_EXPR)
7342     {
7343       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7344           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7345         warning (OPT_Wparentheses,
7346                  "suggest parentheses around comparison in operand of %s",
7347                  code == EQ_EXPR ? "==" : "!=");
7348     }
7349   else if (TREE_CODE_CLASS (code) == tcc_comparison)
7350     {
7351       if ((TREE_CODE_CLASS (code_left) == tcc_comparison
7352            && code_left != NE_EXPR && code_left != EQ_EXPR)
7353           || (TREE_CODE_CLASS (code_right) == tcc_comparison
7354               && code_right != NE_EXPR && code_right != EQ_EXPR))
7355         warning (OPT_Wparentheses, "comparisons like X<=Y<=Z do not "
7356                  "have their mathematical meaning");
7357     }
7358 }
7359
7360 /* If LABEL (a LABEL_DECL) has not been used, issue a warning.  */
7361
7362 void
7363 warn_for_unused_label (tree label)
7364 {
7365   if (!TREE_USED (label))
7366     {
7367       if (DECL_INITIAL (label))
7368         warning (OPT_Wunused_label, "label %q+D defined but not used", label);
7369       else
7370         warning (OPT_Wunused_label, "label %q+D declared but not defined", label);
7371     }
7372 }
7373
7374 #ifndef TARGET_HAS_TARGETCM
7375 struct gcc_targetcm targetcm = TARGETCM_INITIALIZER;
7376 #endif
7377
7378 /* Warn for division by zero according to the value of DIVISOR.  */
7379
7380 void
7381 warn_for_div_by_zero (tree divisor)
7382 {
7383   /* If DIVISOR is zero, and has integral or fixed-point type, issue a warning
7384      about division by zero.  Do not issue a warning if DIVISOR has a
7385      floating-point type, since we consider 0.0/0.0 a valid way of
7386      generating a NaN.  */
7387   if (skip_evaluation == 0
7388       && (integer_zerop (divisor) || fixed_zerop (divisor)))
7389     warning (OPT_Wdiv_by_zero, "division by zero");
7390 }
7391
7392 #include "gt-c-common.h"