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, 2008, 2009
   4    Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "intl.h"
  27 #include "tree.h"
  28 #include "flags.h"
  29 #include "output.h"
  30 #include "c-pragma.h"
  31 #include "rtl.h"
  32 #include "ggc.h"
  33 #include "varray.h"
  34 #include "expr.h"
  35 #include "c-common.h"
  36 #include "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 "diagnostic.h"
  45 #include "tree-iterator.h"
  46 #include "hashtab.h"
  47 #include "tree-mudflap.h"
  48 #include "opts.h"
  49 #include "real.h"
  50 #include "cgraph.h"
  51 #include "target-def.h"
  52 #include "gimple.h"
  53 #include "fixed-value.h"
  54 #include "libfuncs.h"
  55
  56 cpp_reader *parse_in;           /* Declared in c-pragma.h.  */
  57
  58 /* The following symbols are subsumed in the c_global_trees array, and
  59    listed here individually for documentation purposes.
  60
  61    INTEGER_TYPE and REAL_TYPE nodes for the standard data types.
  62
  63         tree short_integer_type_node;
  64         tree long_integer_type_node;
  65         tree long_long_integer_type_node;
  66
  67         tree short_unsigned_type_node;
  68         tree long_unsigned_type_node;
  69         tree long_long_unsigned_type_node;
  70
  71         tree truthvalue_type_node;
  72         tree truthvalue_false_node;
  73         tree truthvalue_true_node;
  74
  75         tree ptrdiff_type_node;
  76
  77         tree unsigned_char_type_node;
  78         tree signed_char_type_node;
  79         tree wchar_type_node;
  80
  81         tree char16_type_node;
  82         tree char32_type_node;
  83
  84         tree float_type_node;
  85         tree double_type_node;
  86         tree long_double_type_node;
  87
  88         tree complex_integer_type_node;
  89         tree complex_float_type_node;
  90         tree complex_double_type_node;
  91         tree complex_long_double_type_node;
  92
  93         tree dfloat32_type_node;
  94         tree dfloat64_type_node;
  95         tree_dfloat128_type_node;
  96
  97         tree intQI_type_node;
  98         tree intHI_type_node;
  99         tree intSI_type_node;
 100         tree intDI_type_node;
 101         tree intTI_type_node;
 102
 103         tree unsigned_intQI_type_node;
 104         tree unsigned_intHI_type_node;
 105         tree unsigned_intSI_type_node;
 106         tree unsigned_intDI_type_node;
 107         tree unsigned_intTI_type_node;
 108
 109         tree widest_integer_literal_type_node;
 110         tree widest_unsigned_literal_type_node;
 111
 112    Nodes for types `void *' and `const void *'.
 113
 114         tree ptr_type_node, const_ptr_type_node;
 115
 116    Nodes for types `char *' and `const char *'.
 117
 118         tree string_type_node, const_string_type_node;
 119
 120    Type `char[SOMENUMBER]'.
 121    Used when an array of char is needed and the size is irrelevant.
 122
 123         tree char_array_type_node;
 124
 125    Type `int[SOMENUMBER]' or something like it.
 126    Used when an array of int needed and the size is irrelevant.
 127
 128         tree int_array_type_node;
 129
 130    Type `wchar_t[SOMENUMBER]' or something like it.
 131    Used when a wide string literal is created.
 132
 133         tree wchar_array_type_node;
 134
 135    Type `char16_t[SOMENUMBER]' or something like it.
 136    Used when a UTF-16 string literal is created.
 137
 138         tree char16_array_type_node;
 139
 140    Type `char32_t[SOMENUMBER]' or something like it.
 141    Used when a UTF-32 string literal is created.
 142
 143         tree char32_array_type_node;
 144
 145    Type `int ()' -- used for implicit declaration of functions.
 146
 147         tree default_function_type;
 148
 149    A VOID_TYPE node, packaged in a TREE_LIST.
 150
 151         tree void_list_node;
 152
 153   The lazily created VAR_DECLs for __FUNCTION__, __PRETTY_FUNCTION__,
 154   and __func__. (C doesn't generate __FUNCTION__ and__PRETTY_FUNCTION__
 155   VAR_DECLS, but C++ does.)
 156
 157         tree function_name_decl_node;
 158         tree pretty_function_name_decl_node;
 159         tree c99_function_name_decl_node;
 160
 161   Stack of nested function name VAR_DECLs.
 162
 163         tree saved_function_name_decls;
 164
 165 */
 166
 167 tree c_global_trees[CTI_MAX];
 168 \f
 169 /* Switches common to the C front ends.  */
 170
 171 /* Nonzero if preprocessing only.  */
 172
 173 int flag_preprocess_only;
 174
 175 /* Nonzero means don't output line number information.  */
 176
 177 char flag_no_line_commands;
 178
 179 /* Nonzero causes -E output not to be done, but directives such as
 180    #define that have side effects are still obeyed.  */
 181
 182 char flag_no_output;
 183
 184 /* Nonzero means dump macros in some fashion.  */
 185
 186 char flag_dump_macros;
 187
 188 /* Nonzero means pass #include lines through to the output.  */
 189
 190 char flag_dump_includes;
 191
 192 /* Nonzero means process PCH files while preprocessing.  */
 193
 194 bool flag_pch_preprocess;
 195
 196 /* The file name to which we should write a precompiled header, or
 197    NULL if no header will be written in this compile.  */
 198
 199 const char *pch_file;
 200
 201 /* Nonzero if an ISO standard was selected.  It rejects macros in the
 202    user's namespace.  */
 203 int flag_iso;
 204
 205 /* Nonzero if -undef was given.  It suppresses target built-in macros
 206    and assertions.  */
 207 int flag_undef;
 208
 209 /* Nonzero means don't recognize the non-ANSI builtin functions.  */
 210
 211 int flag_no_builtin;
 212
 213 /* Nonzero means don't recognize the non-ANSI builtin functions.
 214    -ansi sets this.  */
 215
 216 int flag_no_nonansi_builtin;
 217
 218 /* Nonzero means give `double' the same size as `float'.  */
 219
 220 int flag_short_double;
 221
 222 /* Nonzero means give `wchar_t' the same size as `short'.  */
 223
 224 int flag_short_wchar;
 225
 226 /* Nonzero means allow implicit conversions between vectors with
 227    differing numbers of subparts and/or differing element types.  */
 228 int flag_lax_vector_conversions;
 229
 230 /* Nonzero means allow Microsoft extensions without warnings or errors.  */
 231 int flag_ms_extensions;
 232
 233 /* Nonzero means don't recognize the keyword `asm'.  */
 234
 235 int flag_no_asm;
 236
 237 /* Nonzero means to treat bitfields as signed unless they say `unsigned'.  */
 238
 239 int flag_signed_bitfields = 1;
 240
 241 /* Warn about #pragma directives that are not recognized.  */
 242
 243 int warn_unknown_pragmas; /* Tri state variable.  */
 244
 245 /* Warn about format/argument anomalies in calls to formatted I/O functions
 246    (*printf, *scanf, strftime, strfmon, etc.).  */
 247
 248 int warn_format;
 249
 250 /* Warn about using __null (as NULL in C++) as sentinel.  For code compiled
 251    with GCC this doesn't matter as __null is guaranteed to have the right
 252    size.  */
 253
 254 int warn_strict_null_sentinel;
 255
 256 /* Zero means that faster, ...NonNil variants of objc_msgSend...
 257    calls will be used in ObjC; passing nil receivers to such calls
 258    will most likely result in crashes.  */
 259 int flag_nil_receivers = 1;
 260
 261 /* Nonzero means that code generation will be altered to support
 262    "zero-link" execution.  This currently affects ObjC only, but may
 263    affect other languages in the future.  */
 264 int flag_zero_link = 0;
 265
 266 /* Nonzero means emit an '__OBJC, __image_info' for the current translation
 267    unit.  It will inform the ObjC runtime that class definition(s) herein
 268    contained are to replace one(s) previously loaded.  */
 269 int flag_replace_objc_classes = 0;
 270
 271 /* C/ObjC language option variables.  */
 272
 273
 274 /* Nonzero means allow type mismatches in conditional expressions;
 275    just make their values `void'.  */
 276
 277 int flag_cond_mismatch;
 278
 279 /* Nonzero means enable C89 Amendment 1 features.  */
 280
 281 int flag_isoc94;
 282
 283 /* Nonzero means use the ISO C99 dialect of C.  */
 284
 285 int flag_isoc99;
 286
 287 /* Nonzero means that we have builtin functions, and main is an int.  */
 288
 289 int flag_hosted = 1;
 290
 291
 292 /* ObjC language option variables.  */
 293
 294
 295 /* Open and close the file for outputting class declarations, if
 296    requested (ObjC).  */
 297
 298 int flag_gen_declaration;
 299
 300 /* Tells the compiler that this is a special run.  Do not perform any
 301    compiling, instead we are to test some platform dependent features
 302    and output a C header file with appropriate definitions.  */
 303
 304 int print_struct_values;
 305
 306 /* Tells the compiler what is the constant string class for ObjC.  */
 307
 308 const char *constant_string_class_name;
 309
 310
 311 /* C++ language option variables.  */
 312
 313
 314 /* Nonzero means don't recognize any extension keywords.  */
 315
 316 int flag_no_gnu_keywords;
 317
 318 /* Nonzero means do emit exported implementations of functions even if
 319    they can be inlined.  */
 320
 321 int flag_implement_inlines = 1;
 322
 323 /* Nonzero means that implicit instantiations will be emitted if needed.  */
 324
 325 int flag_implicit_templates = 1;
 326
 327 /* Nonzero means that implicit instantiations of inline templates will be
 328    emitted if needed, even if instantiations of non-inline templates
 329    aren't.  */
 330
 331 int flag_implicit_inline_templates = 1;
 332
 333 /* Nonzero means generate separate instantiation control files and
 334    juggle them at link time.  */
 335
 336 int flag_use_repository;
 337
 338 /* Nonzero if we want to issue diagnostics that the standard says are not
 339    required.  */
 340
 341 int flag_optional_diags = 1;
 342
 343 /* Nonzero means we should attempt to elide constructors when possible.  */
 344
 345 int flag_elide_constructors = 1;
 346
 347 /* Nonzero means that member functions defined in class scope are
 348    inline by default.  */
 349
 350 int flag_default_inline = 1;
 351
 352 /* Controls whether compiler generates 'type descriptor' that give
 353    run-time type information.  */
 354
 355 int flag_rtti = 1;
 356
 357 /* Nonzero if we want to conserve space in the .o files.  We do this
 358    by putting uninitialized data and runtime initialized data into
 359    .common instead of .data at the expense of not flagging multiple
 360    definitions.  */
 361
 362 int flag_conserve_space;
 363
 364 /* Nonzero if we want to obey access control semantics.  */
 365
 366 int flag_access_control = 1;
 367
 368 /* Nonzero if we want to check the return value of new and avoid calling
 369    constructors if it is a null pointer.  */
 370
 371 int flag_check_new;
 372
 373 /* The C++ dialect being used. C++98 is the default.  */
 374
 375 enum cxx_dialect cxx_dialect = cxx98;
 376
 377 /* Nonzero if we want the new ISO rules for pushing a new scope for `for'
 378    initialization variables.
 379    0: Old rules, set by -fno-for-scope.
 380    2: New ISO rules, set by -ffor-scope.
 381    1: Try to implement new ISO rules, but with backup compatibility
 382    (and warnings).  This is the default, for now.  */
 383
 384 int flag_new_for_scope = 1;
 385
 386 /* Nonzero if we want to emit defined symbols with common-like linkage as
 387    weak symbols where possible, in order to conform to C++ semantics.
 388    Otherwise, emit them as local symbols.  */
 389
 390 int flag_weak = 1;
 391
 392 /* 0 means we want the preprocessor to not emit line directives for
 393    the current working directory.  1 means we want it to do it.  -1
 394    means we should decide depending on whether debugging information
 395    is being emitted or not.  */
 396
 397 int flag_working_directory = -1;
 398
 399 /* Nonzero to use __cxa_atexit, rather than atexit, to register
 400    destructors for local statics and global objects.  '2' means it has been
 401    set nonzero as a default, not by a command-line flag.  */
 402
 403 int flag_use_cxa_atexit = DEFAULT_USE_CXA_ATEXIT;
 404
 405 /* Nonzero to use __cxa_get_exception_ptr in C++ exception-handling
 406    code.  '2' means it has not been set explicitly on the command line.  */
 407
 408 int flag_use_cxa_get_exception_ptr = 2;
 409
 410 /* Nonzero means to implement standard semantics for exception
 411    specifications, calling unexpected if an exception is thrown that
 412    doesn't match the specification.  Zero means to treat them as
 413    assertions and optimize accordingly, but not check them.  */
 414
 415 int flag_enforce_eh_specs = 1;
 416
 417 /* Nonzero means to generate thread-safe code for initializing local
 418    statics.  */
 419
 420 int flag_threadsafe_statics = 1;
 421
 422 /* Nonzero if we want to pretty-print template specializations as the
 423    template signature followed by the arguments.  */
 424
 425 int flag_pretty_templates = 1;
 426
 427 /* Nonzero means warn about implicit declarations.  */
 428
 429 int warn_implicit = 1;
 430
 431 /* Maximum template instantiation depth.  This limit is rather
 432    arbitrary, but it exists to limit the time it takes to notice
 433    infinite template instantiations.  */
 434
 435 int max_tinst_depth = 500;
 436
 437
 438
 439 /* The elements of `ridpointers' are identifier nodes for the reserved
 440    type names and storage classes.  It is indexed by a RID_... value.  */
 441 tree *ridpointers;
 442
 443 tree (*make_fname_decl) (tree, int);
 444
 445 /* Nonzero means the expression being parsed will never be evaluated.
 446    This is a count, since unevaluated expressions can nest.  */
 447 int skip_evaluation;
 448
 449 /* Whether lexing has been completed, so subsequent preprocessor
 450    errors should use the compiler's input_location.  */
 451 bool done_lexing = false;
 452
 453 /* Information about how a function name is generated.  */
 454 struct fname_var_t
 455 {
 456   tree *const decl;     /* pointer to the VAR_DECL.  */
 457   const unsigned rid;   /* RID number for the identifier.  */
 458   const int pretty;     /* How pretty is it? */
 459 };
 460
 461 /* The three ways of getting then name of the current function.  */
 462
 463 const struct fname_var_t fname_vars[] =
 464 {
 465   /* C99 compliant __func__, must be first.  */
 466   {&c99_function_name_decl_node, RID_C99_FUNCTION_NAME, 0},
 467   /* GCC __FUNCTION__ compliant.  */
 468   {&function_name_decl_node, RID_FUNCTION_NAME, 0},
 469   /* GCC __PRETTY_FUNCTION__ compliant.  */
 470   {&pretty_function_name_decl_node, RID_PRETTY_FUNCTION_NAME, 1},
 471   {NULL, 0, 0},
 472 };
 473
 474 static tree c_fully_fold_internal (tree expr, bool, bool *, bool *);
 475 static tree check_case_value (tree);
 476 static bool check_case_bounds (tree, tree, tree *, tree *);
 477
 478 static tree handle_packed_attribute (tree *, tree, tree, int, bool *);
 479 static tree handle_nocommon_attribute (tree *, tree, tree, int, bool *);
 480 static tree handle_common_attribute (tree *, tree, tree, int, bool *);
 481 static tree handle_noreturn_attribute (tree *, tree, tree, int, bool *);
 482 static tree handle_hot_attribute (tree *, tree, tree, int, bool *);
 483 static tree handle_cold_attribute (tree *, tree, tree, int, bool *);
 484 static tree handle_noinline_attribute (tree *, tree, tree, int, bool *);
 485 static tree handle_always_inline_attribute (tree *, tree, tree, int,
 486                                             bool *);
 487 static tree handle_gnu_inline_attribute (tree *, tree, tree, int, bool *);
 488 static tree handle_artificial_attribute (tree *, tree, tree, int, bool *);
 489 static tree handle_flatten_attribute (tree *, tree, tree, int, bool *);
 490 static tree handle_error_attribute (tree *, tree, tree, int, bool *);
 491 static tree handle_used_attribute (tree *, tree, tree, int, bool *);
 492 static tree handle_unused_attribute (tree *, tree, tree, int, bool *);
 493 static tree handle_externally_visible_attribute (tree *, tree, tree, int,
 494                                                  bool *);
 495 static tree handle_const_attribute (tree *, tree, tree, int, bool *);
 496 static tree handle_transparent_union_attribute (tree *, tree, tree,
 497                                                 int, bool *);
 498 static tree handle_constructor_attribute (tree *, tree, tree, int, bool *);
 499 static tree handle_destructor_attribute (tree *, tree, tree, int, bool *);
 500 static tree handle_mode_attribute (tree *, tree, tree, int, bool *);
 501 static tree handle_section_attribute (tree *, tree, tree, int, bool *);
 502 static tree handle_aligned_attribute (tree *, tree, tree, int, bool *);
 503 static tree handle_weak_attribute (tree *, tree, tree, int, bool *) ;
 504 static tree handle_alias_attribute (tree *, tree, tree, int, bool *);
 505 static tree handle_weakref_attribute (tree *, tree, tree, int, bool *) ;
 506 static tree handle_visibility_attribute (tree *, tree, tree, int,
 507                                          bool *);
 508 static tree handle_tls_model_attribute (tree *, tree, tree, int,
 509                                         bool *);
 510 static tree handle_no_instrument_function_attribute (tree *, tree,
 511                                                      tree, int, bool *);
 512 static tree handle_malloc_attribute (tree *, tree, tree, int, bool *);
 513 static tree handle_returns_twice_attribute (tree *, tree, tree, int, bool *);
 514 static tree handle_no_limit_stack_attribute (tree *, tree, tree, int,
 515                                              bool *);
 516 static tree handle_pure_attribute (tree *, tree, tree, int, bool *);
 517 static tree handle_novops_attribute (tree *, tree, tree, int, bool *);
 518 static tree handle_deprecated_attribute (tree *, tree, tree, int,
 519                                          bool *);
 520 static tree handle_vector_size_attribute (tree *, tree, tree, int,
 521                                           bool *);
 522 static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *);
 523 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
 524 static tree handle_cleanup_attribute (tree *, tree, tree, int, bool *);
 525 static tree handle_warn_unused_result_attribute (tree *, tree, tree, int,
 526                                                  bool *);
 527 static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *);
 528 static tree handle_type_generic_attribute (tree *, tree, tree, int, bool *);
 529 static tree handle_alloc_size_attribute (tree *, tree, tree, int, bool *);
 530 static tree handle_target_attribute (tree *, tree, tree, int, bool *);
 531 static tree handle_optimize_attribute (tree *, tree, tree, int, bool *);
 532
 533 static void check_function_nonnull (tree, int, tree *);
 534 static void check_nonnull_arg (void *, tree, unsigned HOST_WIDE_INT);
 535 static bool nonnull_check_p (tree, unsigned HOST_WIDE_INT);
 536 static bool get_nonnull_operand (tree, unsigned HOST_WIDE_INT *);
 537 static int resort_field_decl_cmp (const void *, const void *);
 538
 539 /* Reserved words.  The third field is a mask: keywords are disabled
 540    if they match the mask.
 541
 542    Masks for languages:
 543    C --std=c89: D_C99 | D_CXXONLY | D_OBJC | D_CXX_OBJC
 544    C --std=c99: D_CXXONLY | D_OBJC
 545    ObjC is like C except that D_OBJC and D_CXX_OBJC are not set
 546    C++ --std=c98: D_CONLY | D_CXXOX | D_OBJC
 547    C++ --std=c0x: D_CONLY | D_OBJC
 548    ObjC++ is like C++ except that D_OBJC is not set
 549
 550    If -fno-asm is used, D_ASM is added to the mask.  If
 551    -fno-gnu-keywords is used, D_EXT is added.  If -fno-asm and C in
 552    C89 mode, D_EXT89 is added for both -fno-asm and -fno-gnu-keywords.
 553    In C with -Wc++-compat, we warn if D_CXXWARN is set.  */
 554
 555 const struct c_common_resword c_common_reswords[] =
 556 {
 557   { "_Bool",            RID_BOOL,      D_CONLY },
 558   { "_Complex",         RID_COMPLEX,    0 },
 559   { "_Imaginary",       RID_IMAGINARY, D_CONLY },
 560   { "_Decimal32",       RID_DFLOAT32,  D_CONLY | D_EXT },
 561   { "_Decimal64",       RID_DFLOAT64,  D_CONLY | D_EXT },
 562   { "_Decimal128",      RID_DFLOAT128, D_CONLY | D_EXT },
 563   { "_Fract",           RID_FRACT,     D_CONLY | D_EXT },
 564   { "_Accum",           RID_ACCUM,     D_CONLY | D_EXT },
 565   { "_Sat",             RID_SAT,       D_CONLY | D_EXT },
 566   { "__FUNCTION__",     RID_FUNCTION_NAME, 0 },
 567   { "__PRETTY_FUNCTION__", RID_PRETTY_FUNCTION_NAME, 0 },
 568   { "__alignof",        RID_ALIGNOF,    0 },
 569   { "__alignof__",      RID_ALIGNOF,    0 },
 570   { "__asm",            RID_ASM,        0 },
 571   { "__asm__",          RID_ASM,        0 },
 572   { "__attribute",      RID_ATTRIBUTE,  0 },
 573   { "__attribute__",    RID_ATTRIBUTE,  0 },
 574   { "__builtin_choose_expr", RID_CHOOSE_EXPR, D_CONLY },
 575   { "__builtin_offsetof", RID_OFFSETOF, 0 },
 576   { "__builtin_types_compatible_p", RID_TYPES_COMPATIBLE_P, D_CONLY },
 577   { "__builtin_va_arg", RID_VA_ARG,     0 },
 578   { "__complex",        RID_COMPLEX,    0 },
 579   { "__complex__",      RID_COMPLEX,    0 },
 580   { "__const",          RID_CONST,      0 },
 581   { "__const__",        RID_CONST,      0 },
 582   { "__decltype",       RID_DECLTYPE,   D_CXXONLY },
 583   { "__extension__",    RID_EXTENSION,  0 },
 584   { "__func__",         RID_C99_FUNCTION_NAME, 0 },
 585   { "__has_nothrow_assign", RID_HAS_NOTHROW_ASSIGN, D_CXXONLY },
 586   { "__has_nothrow_constructor", RID_HAS_NOTHROW_CONSTRUCTOR, D_CXXONLY },
 587   { "__has_nothrow_copy", RID_HAS_NOTHROW_COPY, D_CXXONLY },
 588   { "__has_trivial_assign", RID_HAS_TRIVIAL_ASSIGN, D_CXXONLY },
 589   { "__has_trivial_constructor", RID_HAS_TRIVIAL_CONSTRUCTOR, D_CXXONLY },
 590   { "__has_trivial_copy", RID_HAS_TRIVIAL_COPY, D_CXXONLY },
 591   { "__has_trivial_destructor", RID_HAS_TRIVIAL_DESTRUCTOR, D_CXXONLY },
 592   { "__has_virtual_destructor", RID_HAS_VIRTUAL_DESTRUCTOR, D_CXXONLY },
 593   { "__is_abstract",    RID_IS_ABSTRACT, D_CXXONLY },
 594   { "__is_base_of",     RID_IS_BASE_OF, D_CXXONLY },
 595   { "__is_class",       RID_IS_CLASS,   D_CXXONLY },
 596   { "__is_convertible_to", RID_IS_CONVERTIBLE_TO, D_CXXONLY },
 597   { "__is_empty",       RID_IS_EMPTY,   D_CXXONLY },
 598   { "__is_enum",        RID_IS_ENUM,    D_CXXONLY },
 599   { "__is_pod",         RID_IS_POD,     D_CXXONLY },
 600   { "__is_polymorphic", RID_IS_POLYMORPHIC, D_CXXONLY },
 601   { "__is_union",       RID_IS_UNION,   D_CXXONLY },
 602   { "__imag",           RID_IMAGPART,   0 },
 603   { "__imag__",         RID_IMAGPART,   0 },
 604   { "__inline",         RID_INLINE,     0 },
 605   { "__inline__",       RID_INLINE,     0 },
 606   { "__label__",        RID_LABEL,      0 },
 607   { "__null",           RID_NULL,       0 },
 608   { "__real",           RID_REALPART,   0 },
 609   { "__real__",         RID_REALPART,   0 },
 610   { "__restrict",       RID_RESTRICT,   0 },
 611   { "__restrict__",     RID_RESTRICT,   0 },
 612   { "__signed",         RID_SIGNED,     0 },
 613   { "__signed__",       RID_SIGNED,     0 },
 614   { "__thread",         RID_THREAD,     0 },
 615   { "__typeof",         RID_TYPEOF,     0 },
 616   { "__typeof__",       RID_TYPEOF,     0 },
 617   { "__volatile",       RID_VOLATILE,   0 },
 618   { "__volatile__",     RID_VOLATILE,   0 },
 619   { "asm",              RID_ASM,        D_ASM },
 620   { "auto",             RID_AUTO,       0 },
 621   { "bool",             RID_BOOL,       D_CXXONLY | D_CXXWARN },
 622   { "break",            RID_BREAK,      0 },
 623   { "case",             RID_CASE,       0 },
 624   { "catch",            RID_CATCH,      D_CXX_OBJC | D_CXXWARN },
 625   { "char",             RID_CHAR,       0 },
 626   { "char16_t",         RID_CHAR16,     D_CXXONLY | D_CXX0X | D_CXXWARN },
 627   { "char32_t",         RID_CHAR32,     D_CXXONLY | D_CXX0X | D_CXXWARN },
 628   { "class",            RID_CLASS,      D_CXX_OBJC | D_CXXWARN },
 629   { "const",            RID_CONST,      0 },
 630   { "const_cast",       RID_CONSTCAST,  D_CXXONLY | D_CXXWARN },
 631   { "continue",         RID_CONTINUE,   0 },
 632   { "decltype",         RID_DECLTYPE,   D_CXXONLY | D_CXX0X | D_CXXWARN },
 633   { "default",          RID_DEFAULT,    0 },
 634   { "delete",           RID_DELETE,     D_CXXONLY | D_CXXWARN },
 635   { "do",               RID_DO,         0 },
 636   { "double",           RID_DOUBLE,     0 },
 637   { "dynamic_cast",     RID_DYNCAST,    D_CXXONLY | D_CXXWARN },
 638   { "else",             RID_ELSE,       0 },
 639   { "enum",             RID_ENUM,       0 },
 640   { "explicit",         RID_EXPLICIT,   D_CXXONLY | D_CXXWARN },
 641   { "export",           RID_EXPORT,     D_CXXONLY | D_CXXWARN },
 642   { "extern",           RID_EXTERN,     0 },
 643   { "false",            RID_FALSE,      D_CXXONLY | D_CXXWARN },
 644   { "float",            RID_FLOAT,      0 },
 645   { "for",              RID_FOR,        0 },
 646   { "friend",           RID_FRIEND,     D_CXXONLY | D_CXXWARN },
 647   { "goto",             RID_GOTO,       0 },
 648   { "if",               RID_IF,         0 },
 649   { "inline",           RID_INLINE,     D_EXT89 },
 650   { "int",              RID_INT,        0 },
 651   { "long",             RID_LONG,       0 },
 652   { "mutable",          RID_MUTABLE,    D_CXXONLY | D_CXXWARN },
 653   { "namespace",        RID_NAMESPACE,  D_CXXONLY | D_CXXWARN },
 654   { "new",              RID_NEW,        D_CXXONLY | D_CXXWARN },
 655   { "operator",         RID_OPERATOR,   D_CXXONLY | D_CXXWARN },
 656   { "private",          RID_PRIVATE,    D_CXX_OBJC | D_CXXWARN },
 657   { "protected",        RID_PROTECTED,  D_CXX_OBJC | D_CXXWARN },
 658   { "public",           RID_PUBLIC,     D_CXX_OBJC | D_CXXWARN },
 659   { "register",         RID_REGISTER,   0 },
 660   { "reinterpret_cast", RID_REINTCAST,  D_CXXONLY | D_CXXWARN },
 661   { "restrict",         RID_RESTRICT,   D_CONLY | D_C99 },
 662   { "return",           RID_RETURN,     0 },
 663   { "short",            RID_SHORT,      0 },
 664   { "signed",           RID_SIGNED,     0 },
 665   { "sizeof",           RID_SIZEOF,     0 },
 666   { "static",           RID_STATIC,     0 },
 667   { "static_assert",    RID_STATIC_ASSERT, D_CXXONLY | D_CXX0X | D_CXXWARN },
 668   { "static_cast",      RID_STATCAST,   D_CXXONLY | D_CXXWARN },
 669   { "struct",           RID_STRUCT,     0 },
 670   { "switch",           RID_SWITCH,     0 },
 671   { "template",         RID_TEMPLATE,   D_CXXONLY | D_CXXWARN },
 672   { "this",             RID_THIS,       D_CXXONLY | D_CXXWARN },
 673   { "throw",            RID_THROW,      D_CXX_OBJC | D_CXXWARN },
 674   { "true",             RID_TRUE,       D_CXXONLY | D_CXXWARN },
 675   { "try",              RID_TRY,        D_CXX_OBJC | D_CXXWARN },
 676   { "typedef",          RID_TYPEDEF,    0 },
 677   { "typename",         RID_TYPENAME,   D_CXXONLY | D_CXXWARN },
 678   { "typeid",           RID_TYPEID,     D_CXXONLY | D_CXXWARN },
 679   { "typeof",           RID_TYPEOF,     D_ASM | D_EXT },
 680   { "union",            RID_UNION,      0 },
 681   { "unsigned",         RID_UNSIGNED,   0 },
 682   { "using",            RID_USING,      D_CXXONLY | D_CXXWARN },
 683   { "virtual",          RID_VIRTUAL,    D_CXXONLY | D_CXXWARN },
 684   { "void",             RID_VOID,       0 },
 685   { "volatile",         RID_VOLATILE,   0 },
 686   { "wchar_t",          RID_WCHAR,      D_CXXONLY },
 687   { "while",            RID_WHILE,      0 },
 688   /* These Objective-C keywords are recognized only immediately after
 689      an '@'.  */
 690   { "compatibility_alias", RID_AT_ALIAS,        D_OBJC },
 691   { "defs",             RID_AT_DEFS,            D_OBJC },
 692   { "encode",           RID_AT_ENCODE,          D_OBJC },
 693   { "end",              RID_AT_END,             D_OBJC },
 694   { "implementation",   RID_AT_IMPLEMENTATION,  D_OBJC },
 695   { "interface",        RID_AT_INTERFACE,       D_OBJC },
 696   { "protocol",         RID_AT_PROTOCOL,        D_OBJC },
 697   { "selector",         RID_AT_SELECTOR,        D_OBJC },
 698   { "finally",          RID_AT_FINALLY,         D_OBJC },
 699   { "synchronized",     RID_AT_SYNCHRONIZED,    D_OBJC },
 700   /* These are recognized only in protocol-qualifier context
 701      (see above) */
 702   { "bycopy",           RID_BYCOPY,             D_OBJC },
 703   { "byref",            RID_BYREF,              D_OBJC },
 704   { "in",               RID_IN,                 D_OBJC },
 705   { "inout",            RID_INOUT,              D_OBJC },
 706   { "oneway",           RID_ONEWAY,             D_OBJC },
 707   { "out",              RID_OUT,                D_OBJC },
 708 };
 709
 710 const unsigned int num_c_common_reswords =
 711   sizeof c_common_reswords / sizeof (struct c_common_resword);
 712
 713 /* Table of machine-independent attributes common to all C-like languages.  */
 714 const struct attribute_spec c_common_attribute_table[] =
 715 {
 716   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 717   { "packed",                 0, 0, false, false, false,
 718                               handle_packed_attribute },
 719   { "nocommon",               0, 0, true,  false, false,
 720                               handle_nocommon_attribute },
 721   { "common",                 0, 0, true,  false, false,
 722                               handle_common_attribute },
 723   /* FIXME: logically, noreturn attributes should be listed as
 724      "false, true, true" and apply to function types.  But implementing this
 725      would require all the places in the compiler that use TREE_THIS_VOLATILE
 726      on a decl to identify non-returning functions to be located and fixed
 727      to check the function type instead.  */
 728   { "noreturn",               0, 0, true,  false, false,
 729                               handle_noreturn_attribute },
 730   { "volatile",               0, 0, true,  false, false,
 731                               handle_noreturn_attribute },
 732   { "noinline",               0, 0, true,  false, false,
 733                               handle_noinline_attribute },
 734   { "always_inline",          0, 0, true,  false, false,
 735                               handle_always_inline_attribute },
 736   { "gnu_inline",             0, 0, true,  false, false,
 737                               handle_gnu_inline_attribute },
 738   { "artificial",             0, 0, true,  false, false,
 739                               handle_artificial_attribute },
 740   { "flatten",                0, 0, true,  false, false,
 741                               handle_flatten_attribute },
 742   { "used",                   0, 0, true,  false, false,
 743                               handle_used_attribute },
 744   { "unused",                 0, 0, false, false, false,
 745                               handle_unused_attribute },
 746   { "externally_visible",     0, 0, true,  false, false,
 747                               handle_externally_visible_attribute },
 748   /* The same comments as for noreturn attributes apply to const ones.  */
 749   { "const",                  0, 0, true,  false, false,
 750                               handle_const_attribute },
 751   { "transparent_union",      0, 0, false, false, false,
 752                               handle_transparent_union_attribute },
 753   { "constructor",            0, 1, true,  false, false,
 754                               handle_constructor_attribute },
 755   { "destructor",             0, 1, true,  false, false,
 756                               handle_destructor_attribute },
 757   { "mode",                   1, 1, false,  true, false,
 758                               handle_mode_attribute },
 759   { "section",                1, 1, true,  false, false,
 760                               handle_section_attribute },
 761   { "aligned",                0, 1, false, false, false,
 762                               handle_aligned_attribute },
 763   { "weak",                   0, 0, true,  false, false,
 764                               handle_weak_attribute },
 765   { "alias",                  1, 1, true,  false, false,
 766                               handle_alias_attribute },
 767   { "weakref",                0, 1, true,  false, false,
 768                               handle_weakref_attribute },
 769   { "no_instrument_function", 0, 0, true,  false, false,
 770                               handle_no_instrument_function_attribute },
 771   { "malloc",                 0, 0, true,  false, false,
 772                               handle_malloc_attribute },
 773   { "returns_twice",          0, 0, true,  false, false,
 774                               handle_returns_twice_attribute },
 775   { "no_stack_limit",         0, 0, true,  false, false,
 776                               handle_no_limit_stack_attribute },
 777   { "pure",                   0, 0, true,  false, false,
 778                               handle_pure_attribute },
 779   /* For internal use (marking of builtins) only.  The name contains space
 780      to prevent its usage in source code.  */
 781   { "no vops",                0, 0, true,  false, false,
 782                               handle_novops_attribute },
 783   { "deprecated",             0, 1, false, false, false,
 784                               handle_deprecated_attribute },
 785   { "vector_size",            1, 1, false, true, false,
 786                               handle_vector_size_attribute },
 787   { "visibility",             1, 1, false, false, false,
 788                               handle_visibility_attribute },
 789   { "tls_model",              1, 1, true,  false, false,
 790                               handle_tls_model_attribute },
 791   { "nonnull",                0, -1, false, true, true,
 792                               handle_nonnull_attribute },
 793   { "nothrow",                0, 0, true,  false, false,
 794                               handle_nothrow_attribute },
 795   { "may_alias",              0, 0, false, true, false, NULL },
 796   { "cleanup",                1, 1, true, false, false,
 797                               handle_cleanup_attribute },
 798   { "warn_unused_result",     0, 0, false, true, true,
 799                               handle_warn_unused_result_attribute },
 800   { "sentinel",               0, 1, false, true, true,
 801                               handle_sentinel_attribute },
 802   /* For internal use (marking of builtins) only.  The name contains space
 803      to prevent its usage in source code.  */
 804   { "type generic",           0, 0, false, true, true,
 805                               handle_type_generic_attribute },
 806   { "alloc_size",             1, 2, false, true, true,
 807                               handle_alloc_size_attribute },
 808   { "cold",                   0, 0, true,  false, false,
 809                               handle_cold_attribute },
 810   { "hot",                    0, 0, true,  false, false,
 811                               handle_hot_attribute },
 812   { "warning",                1, 1, true,  false, false,
 813                               handle_error_attribute },
 814   { "error",                  1, 1, true,  false, false,
 815                               handle_error_attribute },
 816   { "target",                 1, -1, true, false, false,
 817                               handle_target_attribute },
 818   { "optimize",               1, -1, true, false, false,
 819                               handle_optimize_attribute },
 820   { NULL,                     0, 0, false, false, false, NULL }
 821 };
 822
 823 /* Give the specifications for the format attributes, used by C and all
 824    descendants.  */
 825
 826 const struct attribute_spec c_common_format_attribute_table[] =
 827 {
 828   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 829   { "format",                 3, 3, false, true,  true,
 830                               handle_format_attribute },
 831   { "format_arg",             1, 1, false, true,  true,
 832                               handle_format_arg_attribute },
 833   { NULL,                     0, 0, false, false, false, NULL }
 834 };
 835
 836 /* Push current bindings for the function name VAR_DECLS.  */
 837
 838 void
 839 start_fname_decls (void)
 840 {
 841   unsigned ix;
 842   tree saved = NULL_TREE;
 843
 844   for (ix = 0; fname_vars[ix].decl; ix++)
 845     {
 846       tree decl = *fname_vars[ix].decl;
 847
 848       if (decl)
 849         {
 850           saved = tree_cons (decl, build_int_cst (NULL_TREE, ix), saved);
 851           *fname_vars[ix].decl = NULL_TREE;
 852         }
 853     }
 854   if (saved || saved_function_name_decls)
 855     /* Normally they'll have been NULL, so only push if we've got a
 856        stack, or they are non-NULL.  */
 857     saved_function_name_decls = tree_cons (saved, NULL_TREE,
 858                                            saved_function_name_decls);
 859 }
 860
 861 /* Finish up the current bindings, adding them into the current function's
 862    statement tree.  This must be done _before_ finish_stmt_tree is called.
 863    If there is no current function, we must be at file scope and no statements
 864    are involved. Pop the previous bindings.  */
 865
 866 void
 867 finish_fname_decls (void)
 868 {
 869   unsigned ix;
 870   tree stmts = NULL_TREE;
 871   tree stack = saved_function_name_decls;
 872
 873   for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack))
 874     append_to_statement_list (TREE_VALUE (stack), &stmts);
 875
 876   if (stmts)
 877     {
 878       tree *bodyp = &DECL_SAVED_TREE (current_function_decl);
 879
 880       if (TREE_CODE (*bodyp) == BIND_EXPR)
 881         bodyp = &BIND_EXPR_BODY (*bodyp);
 882
 883       append_to_statement_list_force (*bodyp, &stmts);
 884       *bodyp = stmts;
 885     }
 886
 887   for (ix = 0; fname_vars[ix].decl; ix++)
 888     *fname_vars[ix].decl = NULL_TREE;
 889
 890   if (stack)
 891     {
 892       /* We had saved values, restore them.  */
 893       tree saved;
 894
 895       for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved))
 896         {
 897           tree decl = TREE_PURPOSE (saved);
 898           unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved));
 899
 900           *fname_vars[ix].decl = decl;
 901         }
 902       stack = TREE_CHAIN (stack);
 903     }
 904   saved_function_name_decls = stack;
 905 }
 906
 907 /* Return the text name of the current function, suitably prettified
 908    by PRETTY_P.  Return string must be freed by caller.  */
 909
 910 const char *
 911 fname_as_string (int pretty_p)
 912 {
 913   const char *name = "top level";
 914   char *namep;
 915   int vrb = 2, len;
 916   cpp_string cstr = { 0, 0 }, strname;
 917
 918   if (!pretty_p)
 919     {
 920       name = "";
 921       vrb = 0;
 922     }
 923
 924   if (current_function_decl)
 925     name = lang_hooks.decl_printable_name (current_function_decl, vrb);
 926
 927   len = strlen (name) + 3; /* Two for '"'s.  One for NULL.  */
 928
 929   namep = XNEWVEC (char, len);
 930   snprintf (namep, len, "\"%s\"", name);
 931   strname.text = (unsigned char *) namep;
 932   strname.len = len - 1;
 933
 934   if (cpp_interpret_string (parse_in, &strname, 1, &cstr, CPP_STRING))
 935     {
 936       XDELETEVEC (namep);
 937       return (const char *) cstr.text;
 938     }
 939
 940   return namep;
 941 }
 942
 943 /* Return the VAR_DECL for a const char array naming the current
 944    function. If the VAR_DECL has not yet been created, create it
 945    now. RID indicates how it should be formatted and IDENTIFIER_NODE
 946    ID is its name (unfortunately C and C++ hold the RID values of
 947    keywords in different places, so we can't derive RID from ID in
 948    this language independent code. LOC is the location of the
 949    function.  */
 950
 951 tree
 952 fname_decl (location_t loc, unsigned int rid, tree id)
 953 {
 954   unsigned ix;
 955   tree decl = NULL_TREE;
 956
 957   for (ix = 0; fname_vars[ix].decl; ix++)
 958     if (fname_vars[ix].rid == rid)
 959       break;
 960
 961   decl = *fname_vars[ix].decl;
 962   if (!decl)
 963     {
 964       /* If a tree is built here, it would normally have the lineno of
 965          the current statement.  Later this tree will be moved to the
 966          beginning of the function and this line number will be wrong.
 967          To avoid this problem set the lineno to 0 here; that prevents
 968          it from appearing in the RTL.  */
 969       tree stmts;
 970       location_t saved_location = input_location;
 971       input_location = UNKNOWN_LOCATION;
 972
 973       stmts = push_stmt_list ();
 974       decl = (*make_fname_decl) (id, fname_vars[ix].pretty);
 975       stmts = pop_stmt_list (stmts);
 976       if (!IS_EMPTY_STMT (stmts))
 977         saved_function_name_decls
 978           = tree_cons (decl, stmts, saved_function_name_decls);
 979       *fname_vars[ix].decl = decl;
 980       input_location = saved_location;
 981     }
 982   if (!ix && !current_function_decl)
 983     pedwarn (loc, 0, "%qD is not defined outside of function scope", decl);
 984
 985   return decl;
 986 }
 987
 988 /* Given a STRING_CST, give it a suitable array-of-chars data type.  */
 989
 990 tree
 991 fix_string_type (tree value)
 992 {
 993   int length = TREE_STRING_LENGTH (value);
 994   int nchars;
 995   tree e_type, i_type, a_type;
 996
 997   /* Compute the number of elements, for the array type.  */
 998   if (TREE_TYPE (value) == char_array_type_node || !TREE_TYPE (value))
 999     {
1000       nchars = length;
1001       e_type = char_type_node;
1002     }
1003   else if (TREE_TYPE (value) == char16_array_type_node)
1004     {
1005       nchars = length / (TYPE_PRECISION (char16_type_node) / BITS_PER_UNIT);
1006       e_type = char16_type_node;
1007     }
1008   else if (TREE_TYPE (value) == char32_array_type_node)
1009     {
1010       nchars = length / (TYPE_PRECISION (char32_type_node) / BITS_PER_UNIT);
1011       e_type = char32_type_node;
1012     }
1013   else
1014     {
1015       nchars = length / (TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT);
1016       e_type = wchar_type_node;
1017     }
1018
1019   /* C89 2.2.4.1, C99 5.2.4.1 (Translation limits).  The analogous
1020      limit in C++98 Annex B is very large (65536) and is not normative,
1021      so we do not diagnose it (warn_overlength_strings is forced off
1022      in c_common_post_options).  */
1023   if (warn_overlength_strings)
1024     {
1025       const int nchars_max = flag_isoc99 ? 4095 : 509;
1026       const int relevant_std = flag_isoc99 ? 99 : 90;
1027       if (nchars - 1 > nchars_max)
1028         /* Translators: The %d after 'ISO C' will be 90 or 99.  Do not
1029            separate the %d from the 'C'.  'ISO' should not be
1030            translated, but it may be moved after 'C%d' in languages
1031            where modifiers follow nouns.  */
1032         pedwarn (input_location, OPT_Woverlength_strings,
1033                  "string length %qd is greater than the length %qd "
1034                  "ISO C%d compilers are required to support",
1035                  nchars - 1, nchars_max, relevant_std);
1036     }
1037
1038   /* Create the array type for the string constant.  The ISO C++
1039      standard says that a string literal has type `const char[N]' or
1040      `const wchar_t[N]'.  We use the same logic when invoked as a C
1041      front-end with -Wwrite-strings.
1042      ??? We should change the type of an expression depending on the
1043      state of a warning flag.  We should just be warning -- see how
1044      this is handled in the C++ front-end for the deprecated implicit
1045      conversion from string literals to `char*' or `wchar_t*'.
1046
1047      The C++ front end relies on TYPE_MAIN_VARIANT of a cv-qualified
1048      array type being the unqualified version of that type.
1049      Therefore, if we are constructing an array of const char, we must
1050      construct the matching unqualified array type first.  The C front
1051      end does not require this, but it does no harm, so we do it
1052      unconditionally.  */
1053   i_type = build_index_type (build_int_cst (NULL_TREE, nchars - 1));
1054   a_type = build_array_type (e_type, i_type);
1055   if (c_dialect_cxx() || warn_write_strings)
1056     a_type = c_build_qualified_type (a_type, TYPE_QUAL_CONST);
1057
1058   TREE_TYPE (value) = a_type;
1059   TREE_CONSTANT (value) = 1;
1060   TREE_READONLY (value) = 1;
1061   TREE_STATIC (value) = 1;
1062   return value;
1063 }
1064 \f
1065 /* Fully fold EXPR, an expression that was not folded (beyond integer
1066    constant expressions and null pointer constants) when being built
1067    up.  If IN_INIT, this is in a static initializer and certain
1068    changes are made to the folding done.  Clear *MAYBE_CONST if
1069    MAYBE_CONST is not NULL and EXPR is definitely not a constant
1070    expression because it contains an evaluated operator (in C99) or an
1071    operator outside of sizeof returning an integer constant (in C90)
1072    not permitted in constant expressions, or because it contains an
1073    evaluated arithmetic overflow.  (*MAYBE_CONST should typically be
1074    set to true by callers before calling this function.)  Return the
1075    folded expression.  Function arguments have already been folded
1076    before calling this function, as have the contents of SAVE_EXPR,
1077    TARGET_EXPR, BIND_EXPR, VA_ARG_EXPR, OBJ_TYPE_REF and
1078    C_MAYBE_CONST_EXPR.  */
1079
1080 tree
1081 c_fully_fold (tree expr, bool in_init, bool *maybe_const)
1082 {
1083   tree ret;
1084   tree eptype = NULL_TREE;
1085   bool dummy = true;
1086   bool maybe_const_itself = true;
1087
1088   /* This function is not relevant to C++ because C++ folds while
1089      parsing, and may need changes to be correct for C++ when C++
1090      stops folding while parsing.  */
1091   if (c_dialect_cxx ())
1092     gcc_unreachable ();
1093
1094   if (!maybe_const)
1095     maybe_const = &dummy;
1096   if (TREE_CODE (expr) == EXCESS_PRECISION_EXPR)
1097     {
1098       eptype = TREE_TYPE (expr);
1099       expr = TREE_OPERAND (expr, 0);
1100     }
1101   ret = c_fully_fold_internal (expr, in_init, maybe_const,
1102                                &maybe_const_itself);
1103   if (eptype)
1104     ret = fold_convert (eptype, ret);
1105   *maybe_const &= maybe_const_itself;
1106   return ret;
1107 }
1108
1109 /* Internal helper for c_fully_fold.  EXPR and IN_INIT are as for
1110    c_fully_fold.  *MAYBE_CONST_OPERANDS is cleared because of operands
1111    not permitted, while *MAYBE_CONST_ITSELF is cleared because of
1112    arithmetic overflow (for C90, *MAYBE_CONST_OPERANDS is carried from
1113    both evaluated and unevaluated subexpressions while
1114    *MAYBE_CONST_ITSELF is carried from only evaluated
1115    subexpressions).  */
1116
1117 static tree
1118 c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands,
1119                        bool *maybe_const_itself)
1120 {
1121   tree ret = expr;
1122   enum tree_code code = TREE_CODE (expr);
1123   enum tree_code_class kind = TREE_CODE_CLASS (code);
1124   location_t loc = EXPR_LOCATION (expr);
1125   tree op0, op1, op2, op3;
1126   tree orig_op0, orig_op1, orig_op2;
1127   bool op0_const = true, op1_const = true, op2_const = true;
1128   bool op0_const_self = true, op1_const_self = true, op2_const_self = true;
1129   bool nowarning = TREE_NO_WARNING (expr);
1130
1131   /* This function is not relevant to C++ because C++ folds while
1132      parsing, and may need changes to be correct for C++ when C++
1133      stops folding while parsing.  */
1134   if (c_dialect_cxx ())
1135     gcc_unreachable ();
1136
1137   /* Constants, declarations, statements, errors, SAVE_EXPRs and
1138      anything else not counted as an expression cannot usefully be
1139      folded further at this point.  */
1140   if (!IS_EXPR_CODE_CLASS (kind)
1141       || kind == tcc_statement
1142       || code == SAVE_EXPR)
1143     return expr;
1144
1145   /* Operands of variable-length expressions (function calls) have
1146      already been folded, as have __builtin_* function calls, and such
1147      expressions cannot occur in constant expressions.  */
1148   if (kind == tcc_vl_exp)
1149     {
1150       *maybe_const_operands = false;
1151       ret = fold (expr);
1152       goto out;
1153     }
1154
1155   if (code == C_MAYBE_CONST_EXPR)
1156     {
1157       tree pre = C_MAYBE_CONST_EXPR_PRE (expr);
1158       tree inner = C_MAYBE_CONST_EXPR_EXPR (expr);
1159       if (C_MAYBE_CONST_EXPR_NON_CONST (expr))
1160         *maybe_const_operands = false;
1161       if (C_MAYBE_CONST_EXPR_INT_OPERANDS (expr))
1162         *maybe_const_itself = false;
1163       if (pre && !in_init)
1164         ret = build2 (COMPOUND_EXPR, TREE_TYPE (expr), pre, inner);
1165       else
1166         ret = inner;
1167       goto out;
1168     }
1169
1170   /* Assignment, increment, decrement, function call and comma
1171      operators, and statement expressions, cannot occur in constant
1172      expressions if evaluated / outside of sizeof.  (Function calls
1173      were handled above, though VA_ARG_EXPR is treated like a function
1174      call here, and statement expressions are handled through
1175      C_MAYBE_CONST_EXPR to avoid folding inside them.)  */
1176   switch (code)
1177     {
1178     case MODIFY_EXPR:
1179     case PREDECREMENT_EXPR:
1180     case PREINCREMENT_EXPR:
1181     case POSTDECREMENT_EXPR:
1182     case POSTINCREMENT_EXPR:
1183     case COMPOUND_EXPR:
1184       *maybe_const_operands = false;
1185       break;
1186
1187     case VA_ARG_EXPR:
1188     case TARGET_EXPR:
1189     case BIND_EXPR:
1190     case OBJ_TYPE_REF:
1191       *maybe_const_operands = false;
1192       ret = fold (expr);
1193       goto out;
1194
1195     default:
1196       break;
1197     }
1198
1199   /* Fold individual tree codes as appropriate.  */
1200   switch (code)
1201     {
1202     case COMPOUND_LITERAL_EXPR:
1203       /* Any non-constancy will have been marked in a containing
1204          C_MAYBE_CONST_EXPR; there is no more folding to do here.  */
1205       goto out;
1206
1207     case COMPONENT_REF:
1208       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1209       op1 = TREE_OPERAND (expr, 1);
1210       op2 = TREE_OPERAND (expr, 2);
1211       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1212                                    maybe_const_itself);
1213       if (op0 != orig_op0)
1214         ret = build3 (COMPONENT_REF, TREE_TYPE (expr), op0, op1, op2);
1215       if (ret != expr)
1216         {
1217           TREE_READONLY (ret) = TREE_READONLY (expr);
1218           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1219         }
1220       goto out;
1221
1222     case ARRAY_REF:
1223       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1224       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1225       op2 = TREE_OPERAND (expr, 2);
1226       op3 = TREE_OPERAND (expr, 3);
1227       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1228                                    maybe_const_itself);
1229       op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
1230                                    maybe_const_itself);
1231       op1 = decl_constant_value_for_optimization (op1);
1232       if (op0 != orig_op0 || op1 != orig_op1)
1233         ret = build4 (ARRAY_REF, TREE_TYPE (expr), op0, op1, op2, op3);
1234       if (ret != expr)
1235         {
1236           TREE_READONLY (ret) = TREE_READONLY (expr);
1237           TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (expr);
1238           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1239         }
1240       ret = fold (ret);
1241       goto out;
1242
1243     case COMPOUND_EXPR:
1244     case MODIFY_EXPR:
1245     case PREDECREMENT_EXPR:
1246     case PREINCREMENT_EXPR:
1247     case POSTDECREMENT_EXPR:
1248     case POSTINCREMENT_EXPR:
1249     case PLUS_EXPR:
1250     case MINUS_EXPR:
1251     case MULT_EXPR:
1252     case POINTER_PLUS_EXPR:
1253     case TRUNC_DIV_EXPR:
1254     case CEIL_DIV_EXPR:
1255     case FLOOR_DIV_EXPR:
1256     case TRUNC_MOD_EXPR:
1257     case RDIV_EXPR:
1258     case EXACT_DIV_EXPR:
1259     case LSHIFT_EXPR:
1260     case RSHIFT_EXPR:
1261     case BIT_IOR_EXPR:
1262     case BIT_XOR_EXPR:
1263     case BIT_AND_EXPR:
1264     case LT_EXPR:
1265     case LE_EXPR:
1266     case GT_EXPR:
1267     case GE_EXPR:
1268     case EQ_EXPR:
1269     case NE_EXPR:
1270     case COMPLEX_EXPR:
1271     case TRUTH_AND_EXPR:
1272     case TRUTH_OR_EXPR:
1273     case TRUTH_XOR_EXPR:
1274     case UNORDERED_EXPR:
1275     case ORDERED_EXPR:
1276     case UNLT_EXPR:
1277     case UNLE_EXPR:
1278     case UNGT_EXPR:
1279     case UNGE_EXPR:
1280     case UNEQ_EXPR:
1281       /* Binary operations evaluating both arguments (increment and
1282          decrement are binary internally in GCC).  */
1283       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1284       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1285       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1286                                    maybe_const_itself);
1287       if (code != MODIFY_EXPR
1288           && code != PREDECREMENT_EXPR
1289           && code != PREINCREMENT_EXPR
1290           && code != POSTDECREMENT_EXPR
1291           && code != POSTINCREMENT_EXPR)
1292         op0 = decl_constant_value_for_optimization (op0);
1293       /* The RHS of a MODIFY_EXPR was fully folded when building that
1294          expression for the sake of conversion warnings.  */
1295       if (code != MODIFY_EXPR)
1296         op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
1297                                      maybe_const_itself);
1298       op1 = decl_constant_value_for_optimization (op1);
1299       if (op0 != orig_op0 || op1 != orig_op1 || in_init)
1300         ret = in_init
1301           ? fold_build2_initializer (code, TREE_TYPE (expr), op0, op1)
1302           : fold_build2 (code, TREE_TYPE (expr), op0, op1);
1303       else
1304         ret = fold (expr);
1305       goto out;
1306
1307     case INDIRECT_REF:
1308     case FIX_TRUNC_EXPR:
1309     case FLOAT_EXPR:
1310     CASE_CONVERT:
1311     case NON_LVALUE_EXPR:
1312     case NEGATE_EXPR:
1313     case BIT_NOT_EXPR:
1314     case TRUTH_NOT_EXPR:
1315     case ADDR_EXPR:
1316     case CONJ_EXPR:
1317     case REALPART_EXPR:
1318     case IMAGPART_EXPR:
1319       /* Unary operations.  */
1320       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1321       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1322                                    maybe_const_itself);
1323       if (code != ADDR_EXPR && code != REALPART_EXPR && code != IMAGPART_EXPR)
1324         op0 = decl_constant_value_for_optimization (op0);
1325       if (op0 != orig_op0 || in_init)
1326         ret = in_init
1327           ? fold_build1_initializer (code, TREE_TYPE (expr), op0)
1328           : fold_build1 (code, TREE_TYPE (expr), op0);
1329       else
1330         ret = fold (expr);
1331       if (code == INDIRECT_REF
1332           && ret != expr
1333           && TREE_CODE (ret) == INDIRECT_REF)
1334         {
1335           TREE_READONLY (ret) = TREE_READONLY (expr);
1336           TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (expr);
1337           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1338         }
1339       goto out;
1340
1341     case TRUTH_ANDIF_EXPR:
1342     case TRUTH_ORIF_EXPR:
1343       /* Binary operations not necessarily evaluating both
1344          arguments.  */
1345       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1346       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1347       op0 = c_fully_fold_internal (op0, in_init, &op0_const, &op0_const_self);
1348       op1 = c_fully_fold_internal (op1, in_init, &op1_const, &op1_const_self);
1349       if (op0 != orig_op0 || op1 != orig_op1 || in_init)
1350         ret = in_init
1351           ? fold_build2_initializer (code, TREE_TYPE (expr), op0, op1)
1352           : fold_build2 (code, TREE_TYPE (expr), op0, op1);
1353       else
1354         ret = fold (expr);
1355       *maybe_const_operands &= op0_const;
1356       *maybe_const_itself &= op0_const_self;
1357       if (!(flag_isoc99
1358             && op0_const
1359             && op0_const_self
1360             && (code == TRUTH_ANDIF_EXPR
1361                 ? op0 == truthvalue_false_node
1362                 : op0 == truthvalue_true_node)))
1363         *maybe_const_operands &= op1_const;
1364       if (!(op0_const
1365             && op0_const_self
1366             && (code == TRUTH_ANDIF_EXPR
1367                 ? op0 == truthvalue_false_node
1368                 : op0 == truthvalue_true_node)))
1369         *maybe_const_itself &= op1_const_self;
1370       goto out;
1371
1372     case COND_EXPR:
1373       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1374       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1375       orig_op2 = op2 = TREE_OPERAND (expr, 2);
1376       op0 = c_fully_fold_internal (op0, in_init, &op0_const, &op0_const_self);
1377       op1 = c_fully_fold_internal (op1, in_init, &op1_const, &op1_const_self);
1378       op2 = c_fully_fold_internal (op2, in_init, &op2_const, &op2_const_self);
1379       if (op0 != orig_op0 || op1 != orig_op1 || op2 != orig_op2)
1380         ret = fold_build3 (code, TREE_TYPE (expr), op0, op1, op2);
1381       else
1382         ret = fold (expr);
1383       *maybe_const_operands &= op0_const;
1384       *maybe_const_itself &= op0_const_self;
1385       if (!(flag_isoc99
1386             && op0_const
1387             && op0_const_self
1388             && op0 == truthvalue_false_node))
1389         *maybe_const_operands &= op1_const;
1390       if (!(op0_const
1391             && op0_const_self
1392             && op0 == truthvalue_false_node))
1393         *maybe_const_itself &= op1_const_self;
1394       if (!(flag_isoc99
1395             && op0_const
1396             && op0_const_self
1397             && op0 == truthvalue_true_node))
1398         *maybe_const_operands &= op2_const;
1399       if (!(op0_const
1400             && op0_const_self
1401             && op0 == truthvalue_true_node))
1402         *maybe_const_itself &= op2_const_self;
1403       goto out;
1404
1405     case EXCESS_PRECISION_EXPR:
1406       /* Each case where an operand with excess precision may be
1407          encountered must remove the EXCESS_PRECISION_EXPR around
1408          inner operands and possibly put one around the whole
1409          expression or possibly convert to the semantic type (which
1410          c_fully_fold does); we cannot tell at this stage which is
1411          appropriate in any particular case.  */
1412       gcc_unreachable ();
1413
1414     default:
1415       /* Various codes may appear through folding built-in functions
1416          and their arguments.  */
1417       goto out;
1418     }
1419
1420  out:
1421   /* Some folding may introduce NON_LVALUE_EXPRs; all lvalue checks
1422      have been done by this point, so remove them again.  */
1423   nowarning |= TREE_NO_WARNING (ret);
1424   STRIP_TYPE_NOPS (ret);
1425   if (nowarning && !TREE_NO_WARNING (ret))
1426     {
1427       if (!CAN_HAVE_LOCATION_P (ret))
1428         ret = build1 (NOP_EXPR, TREE_TYPE (ret), ret);
1429       TREE_NO_WARNING (ret) = 1;
1430     }
1431   if (ret != expr)
1432     protected_set_expr_location (ret, loc);
1433   return ret;
1434 }
1435
1436 /* If not optimizing, EXP is not a VAR_DECL, or EXP has array type,
1437    return EXP.  Otherwise, return either EXP or its known constant
1438    value (if it has one), but return EXP if EXP has mode BLKmode.  ???
1439    Is the BLKmode test appropriate?  */
1440
1441 tree
1442 decl_constant_value_for_optimization (tree exp)
1443 {
1444   tree ret;
1445
1446   /* This function is only used by C, for c_fully_fold and other
1447      optimization, and may not be correct for C++.  */
1448   if (c_dialect_cxx ())
1449     gcc_unreachable ();
1450
1451   if (!optimize
1452       || TREE_CODE (exp) != VAR_DECL
1453       || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
1454       || DECL_MODE (exp) == BLKmode)
1455     return exp;
1456
1457   ret = decl_constant_value (exp);
1458   /* Avoid unwanted tree sharing between the initializer and current
1459      function's body where the tree can be modified e.g. by the
1460      gimplifier.  */
1461   if (ret != exp && TREE_STATIC (exp))
1462     ret = unshare_expr (ret);
1463   return ret;
1464 }
1465
1466 /* Print a warning if a constant expression had overflow in folding.
1467    Invoke this function on every expression that the language
1468    requires to be a constant expression.
1469    Note the ANSI C standard says it is erroneous for a
1470    constant expression to overflow.  */
1471
1472 void
1473 constant_expression_warning (tree value)
1474 {
1475   if (warn_overflow && pedantic
1476       && (TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
1477           || TREE_CODE (value) == FIXED_CST
1478           || TREE_CODE (value) == VECTOR_CST
1479           || TREE_CODE (value) == COMPLEX_CST)
1480       && TREE_OVERFLOW (value))
1481     pedwarn (input_location, OPT_Woverflow, "overflow in constant expression");
1482 }
1483
1484 /* The same as above but print an unconditional error.  */
1485 void
1486 constant_expression_error (tree value)
1487 {
1488   if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
1489        || TREE_CODE (value) == FIXED_CST
1490        || TREE_CODE (value) == VECTOR_CST
1491        || TREE_CODE (value) == COMPLEX_CST)
1492       && TREE_OVERFLOW (value))
1493     error ("overflow in constant expression");
1494 }
1495
1496 /* Print a warning if an expression had overflow in folding and its
1497    operands hadn't.
1498
1499    Invoke this function on every expression that
1500    (1) appears in the source code, and
1501    (2) is a constant expression that overflowed, and
1502    (3) is not already checked by convert_and_check;
1503    however, do not invoke this function on operands of explicit casts
1504    or when the expression is the result of an operator and any operand
1505    already overflowed.  */
1506
1507 void
1508 overflow_warning (tree value)
1509 {
1510   if (skip_evaluation) return;
1511
1512   switch (TREE_CODE (value))
1513     {
1514     case INTEGER_CST:
1515       warning (OPT_Woverflow, "integer overflow in expression");
1516       break;
1517
1518     case REAL_CST:
1519       warning (OPT_Woverflow, "floating point overflow in expression");
1520       break;
1521
1522     case FIXED_CST:
1523       warning (OPT_Woverflow, "fixed-point overflow in expression");
1524       break;
1525
1526     case VECTOR_CST:
1527       warning (OPT_Woverflow, "vector overflow in expression");
1528       break;
1529
1530     case COMPLEX_CST:
1531       if (TREE_CODE (TREE_REALPART (value)) == INTEGER_CST)
1532         warning (OPT_Woverflow, "complex integer overflow in expression");
1533       else if (TREE_CODE (TREE_REALPART (value)) == REAL_CST)
1534         warning (OPT_Woverflow, "complex floating point overflow in expression");
1535       break;
1536
1537     default:
1538       break;
1539     }
1540 }
1541
1542 /* Warn about uses of logical || / && operator in a context where it
1543    is likely that the bitwise equivalent was intended by the
1544    programmer.  We have seen an expression in which CODE is a binary
1545    operator used to combine expressions OP_LEFT and OP_RIGHT, which before folding
1546    had CODE_LEFT and CODE_RIGHT, into an expression of type TYPE.  */
1547 void
1548 warn_logical_operator (location_t location, enum tree_code code, tree type,
1549                        enum tree_code code_left, tree op_left,
1550                        enum tree_code ARG_UNUSED (code_right), tree op_right)
1551 {
1552   int or_op = (code == TRUTH_ORIF_EXPR || code == TRUTH_OR_EXPR);
1553   int in0_p, in1_p, in_p;
1554   tree low0, low1, low, high0, high1, high, lhs, rhs, tem;
1555   bool strict_overflow_p = false;
1556
1557   if (code != TRUTH_ANDIF_EXPR
1558       && code != TRUTH_AND_EXPR
1559       && code != TRUTH_ORIF_EXPR
1560       && code != TRUTH_OR_EXPR)
1561     return;
1562
1563   /* Warn if &&/|| are being used in a context where it is
1564      likely that the bitwise equivalent was intended by the
1565      programmer. That is, an expression such as op && MASK
1566      where op should not be any boolean expression, nor a
1567      constant, and mask seems to be a non-boolean integer constant.  */
1568   if (!truth_value_p (code_left)
1569       && INTEGRAL_TYPE_P (TREE_TYPE (op_left))
1570       && !CONSTANT_CLASS_P (op_left)
1571       && !TREE_NO_WARNING (op_left)
1572       && TREE_CODE (op_right) == INTEGER_CST
1573       && !integer_zerop (op_right)
1574       && !integer_onep (op_right))
1575     {
1576       if (or_op)
1577         warning_at (location, OPT_Wlogical_op, "logical %<or%>"
1578                     " applied to non-boolean constant");
1579       else
1580         warning_at (location, OPT_Wlogical_op, "logical %<and%>"
1581                     " applied to non-boolean constant");
1582       TREE_NO_WARNING (op_left) = true;
1583       return;
1584     }
1585
1586   /* We do not warn for constants because they are typical of macro
1587      expansions that test for features.  */
1588   if (CONSTANT_CLASS_P (op_left) || CONSTANT_CLASS_P (op_right))
1589     return;
1590
1591   /* This warning only makes sense with logical operands.  */
1592   if (!(truth_value_p (TREE_CODE (op_left))
1593         || INTEGRAL_TYPE_P (TREE_TYPE (op_left)))
1594       || !(truth_value_p (TREE_CODE (op_right))
1595            || INTEGRAL_TYPE_P (TREE_TYPE (op_right))))
1596     return;
1597
1598   lhs = make_range (op_left, &in0_p, &low0, &high0, &strict_overflow_p);
1599   rhs = make_range (op_right, &in1_p, &low1, &high1, &strict_overflow_p);
1600
1601   if (lhs && TREE_CODE (lhs) == C_MAYBE_CONST_EXPR)
1602     lhs = C_MAYBE_CONST_EXPR_EXPR (lhs);
1603
1604   if (rhs && TREE_CODE (rhs) == C_MAYBE_CONST_EXPR)
1605     rhs = C_MAYBE_CONST_EXPR_EXPR (rhs);
1606
1607   /* If this is an OR operation, invert both sides; we will invert
1608      again at the end.  */
1609   if (or_op)
1610     in0_p = !in0_p, in1_p = !in1_p;
1611
1612   /* If both expressions are the same, if we can merge the ranges, and we
1613      can build the range test, return it or it inverted.  */
1614   if (lhs && rhs && operand_equal_p (lhs, rhs, 0)
1615       && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
1616                        in1_p, low1, high1)
1617       && 0 != (tem = build_range_check (type, lhs, in_p, low, high)))
1618     {
1619       if (TREE_CODE (tem) != INTEGER_CST)
1620         return;
1621
1622       if (or_op)
1623         warning_at (location, OPT_Wlogical_op,
1624                     "logical %<or%> "
1625                     "of collectively exhaustive tests is always true");
1626       else
1627         warning_at (location, OPT_Wlogical_op,
1628                     "logical %<and%> "
1629                     "of mutually exclusive tests is always false");
1630     }
1631 }
1632
1633
1634 /* Print a warning about casts that might indicate violation
1635    of strict aliasing rules if -Wstrict-aliasing is used and
1636    strict aliasing mode is in effect. OTYPE is the original
1637    TREE_TYPE of EXPR, and TYPE the type we're casting to. */
1638
1639 bool
1640 strict_aliasing_warning (tree otype, tree type, tree expr)
1641 {
1642   /* Strip pointer conversion chains and get to the correct original type.  */
1643   STRIP_NOPS (expr);
1644   otype = TREE_TYPE (expr);
1645
1646   if (!(flag_strict_aliasing
1647         && POINTER_TYPE_P (type)
1648         && POINTER_TYPE_P (otype)
1649         && !VOID_TYPE_P (TREE_TYPE (type)))
1650       /* If the type we are casting to is a ref-all pointer
1651          dereferencing it is always valid.  */
1652       || TYPE_REF_CAN_ALIAS_ALL (type))
1653     return false;
1654
1655   if ((warn_strict_aliasing > 1) && TREE_CODE (expr) == ADDR_EXPR
1656       && (DECL_P (TREE_OPERAND (expr, 0))
1657           || handled_component_p (TREE_OPERAND (expr, 0))))
1658     {
1659       /* Casting the address of an object to non void pointer. Warn
1660          if the cast breaks type based aliasing.  */
1661       if (!COMPLETE_TYPE_P (TREE_TYPE (type)) && warn_strict_aliasing == 2)
1662         {
1663           warning (OPT_Wstrict_aliasing, "type-punning to incomplete type "
1664                    "might break strict-aliasing rules");
1665           return true;
1666         }
1667       else
1668         {
1669           /* warn_strict_aliasing >= 3.   This includes the default (3).
1670              Only warn if the cast is dereferenced immediately.  */
1671           alias_set_type set1 =
1672             get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0)));
1673           alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1674
1675           if (set1 != set2 && set2 != 0
1676               && (set1 == 0 || !alias_sets_conflict_p (set1, set2)))
1677             {
1678               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1679                        "pointer will break strict-aliasing rules");
1680               return true;
1681             }
1682           else if (warn_strict_aliasing == 2
1683                    && !alias_sets_must_conflict_p (set1, set2))
1684             {
1685               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1686                        "pointer might break strict-aliasing rules");
1687               return true;
1688             }
1689         }
1690     }
1691   else
1692     if ((warn_strict_aliasing == 1) && !VOID_TYPE_P (TREE_TYPE (otype)))
1693       {
1694         /* At this level, warn for any conversions, even if an address is
1695            not taken in the same statement.  This will likely produce many
1696            false positives, but could be useful to pinpoint problems that
1697            are not revealed at higher levels.  */
1698         alias_set_type set1 = get_alias_set (TREE_TYPE (otype));
1699         alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1700         if (!COMPLETE_TYPE_P (type)
1701             || !alias_sets_must_conflict_p (set1, set2))
1702           {
1703             warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1704                      "pointer might break strict-aliasing rules");
1705             return true;
1706           }
1707       }
1708
1709   return false;
1710 }
1711
1712 /* Warn for unlikely, improbable, or stupid DECL declarations
1713    of `main'.  */
1714
1715 void
1716 check_main_parameter_types (tree decl)
1717 {
1718   tree args;
1719   int argct = 0;
1720
1721   for (args = TYPE_ARG_TYPES (TREE_TYPE (decl)); args;
1722       args = TREE_CHAIN (args))
1723    {
1724      tree type = args ? TREE_VALUE (args) : 0;
1725
1726      if (type == void_type_node || type == error_mark_node )
1727        break;
1728
1729      ++argct;
1730      switch (argct)
1731        {
1732        case 1:
1733          if (TYPE_MAIN_VARIANT (type) != integer_type_node)
1734            pedwarn (input_location, OPT_Wmain, "first argument of %q+D should be %<int%>",
1735                     decl);
1736          break;
1737
1738        case 2:
1739          if (TREE_CODE (type) != POINTER_TYPE
1740              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1741              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1742                  != char_type_node))
1743            pedwarn (input_location, OPT_Wmain, "second argument of %q+D should be %<char **%>",
1744                     decl);
1745          break;
1746
1747        case 3:
1748          if (TREE_CODE (type) != POINTER_TYPE
1749              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1750              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1751                  != char_type_node))
1752            pedwarn (input_location, OPT_Wmain, "third argument of %q+D should probably be "
1753                     "%<char **%>", decl);
1754          break;
1755        }
1756    }
1757
1758   /* It is intentional that this message does not mention the third
1759     argument because it's only mentioned in an appendix of the
1760     standard.  */
1761   if (argct > 0 && (argct < 2 || argct > 3))
1762     pedwarn (input_location, OPT_Wmain, "%q+D takes only zero or two arguments", decl);
1763 }
1764
1765 /* True if pointers to distinct types T1 and T2 can be converted to
1766    each other without an explicit cast.  Only returns true for opaque
1767    vector types.  */
1768 bool
1769 vector_targets_convertible_p (const_tree t1, const_tree t2)
1770 {
1771   if (TREE_CODE (t1) == VECTOR_TYPE && TREE_CODE (t2) == VECTOR_TYPE
1772       && (TYPE_VECTOR_OPAQUE (t1) || TYPE_VECTOR_OPAQUE (t2))
1773       && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)))
1774     return true;
1775
1776   return false;
1777 }
1778
1779 /* True if vector types T1 and T2 can be converted to each other
1780    without an explicit cast.  If EMIT_LAX_NOTE is true, and T1 and T2
1781    can only be converted with -flax-vector-conversions yet that is not
1782    in effect, emit a note telling the user about that option if such
1783    a note has not previously been emitted.  */
1784 bool
1785 vector_types_convertible_p (const_tree t1, const_tree t2, bool emit_lax_note)
1786 {
1787   static bool emitted_lax_note = false;
1788   bool convertible_lax;
1789
1790   if ((TYPE_VECTOR_OPAQUE (t1) || TYPE_VECTOR_OPAQUE (t2))
1791       && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)))
1792     return true;
1793
1794   convertible_lax =
1795     (tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2))
1796      && (TREE_CODE (TREE_TYPE (t1)) != REAL_TYPE ||
1797          TYPE_PRECISION (t1) == TYPE_PRECISION (t2))
1798      && (INTEGRAL_TYPE_P (TREE_TYPE (t1))
1799          == INTEGRAL_TYPE_P (TREE_TYPE (t2))));
1800
1801   if (!convertible_lax || flag_lax_vector_conversions)
1802     return convertible_lax;
1803
1804   if (TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1805       && lang_hooks.types_compatible_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1806     return true;
1807
1808   if (emit_lax_note && !emitted_lax_note)
1809     {
1810       emitted_lax_note = true;
1811       inform (input_location, "use -flax-vector-conversions to permit "
1812               "conversions between vectors with differing "
1813               "element types or numbers of subparts");
1814     }
1815
1816   return false;
1817 }
1818
1819 /* This is a helper function of build_binary_op.
1820
1821    For certain operations if both args were extended from the same
1822    smaller type, do the arithmetic in that type and then extend.
1823
1824    BITWISE indicates a bitwise operation.
1825    For them, this optimization is safe only if
1826    both args are zero-extended or both are sign-extended.
1827    Otherwise, we might change the result.
1828    Eg, (short)-1 | (unsigned short)-1 is (int)-1
1829    but calculated in (unsigned short) it would be (unsigned short)-1.
1830 */
1831 tree shorten_binary_op (tree result_type, tree op0, tree op1, bool bitwise)
1832 {
1833   int unsigned0, unsigned1;
1834   tree arg0, arg1;
1835   int uns;
1836   tree type;
1837
1838   /* Cast OP0 and OP1 to RESULT_TYPE.  Doing so prevents
1839      excessive narrowing when we call get_narrower below.  For
1840      example, suppose that OP0 is of unsigned int extended
1841      from signed char and that RESULT_TYPE is long long int.
1842      If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
1843      like
1844
1845      (long long int) (unsigned int) signed_char
1846
1847      which get_narrower would narrow down to
1848
1849      (unsigned int) signed char
1850
1851      If we do not cast OP0 first, get_narrower would return
1852      signed_char, which is inconsistent with the case of the
1853      explicit cast.  */
1854   op0 = convert (result_type, op0);
1855   op1 = convert (result_type, op1);
1856
1857   arg0 = get_narrower (op0, &unsigned0);
1858   arg1 = get_narrower (op1, &unsigned1);
1859
1860   /* UNS is 1 if the operation to be done is an unsigned one.  */
1861   uns = TYPE_UNSIGNED (result_type);
1862
1863   /* Handle the case that OP0 (or OP1) does not *contain* a conversion
1864      but it *requires* conversion to FINAL_TYPE.  */
1865
1866   if ((TYPE_PRECISION (TREE_TYPE (op0))
1867        == TYPE_PRECISION (TREE_TYPE (arg0)))
1868       && TREE_TYPE (op0) != result_type)
1869     unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
1870   if ((TYPE_PRECISION (TREE_TYPE (op1))
1871        == TYPE_PRECISION (TREE_TYPE (arg1)))
1872       && TREE_TYPE (op1) != result_type)
1873     unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
1874
1875   /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE.  */
1876
1877   /* For bitwise operations, signedness of nominal type
1878      does not matter.  Consider only how operands were extended.  */
1879   if (bitwise)
1880     uns = unsigned0;
1881
1882   /* Note that in all three cases below we refrain from optimizing
1883      an unsigned operation on sign-extended args.
1884      That would not be valid.  */
1885
1886   /* Both args variable: if both extended in same way
1887      from same width, do it in that width.
1888      Do it unsigned if args were zero-extended.  */
1889   if ((TYPE_PRECISION (TREE_TYPE (arg0))
1890        < TYPE_PRECISION (result_type))
1891       && (TYPE_PRECISION (TREE_TYPE (arg1))
1892           == TYPE_PRECISION (TREE_TYPE (arg0)))
1893       && unsigned0 == unsigned1
1894       && (unsigned0 || !uns))
1895     return c_common_signed_or_unsigned_type
1896       (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
1897
1898   else if (TREE_CODE (arg0) == INTEGER_CST
1899            && (unsigned1 || !uns)
1900            && (TYPE_PRECISION (TREE_TYPE (arg1))
1901                < TYPE_PRECISION (result_type))
1902            && (type
1903                = c_common_signed_or_unsigned_type (unsigned1,
1904                                                    TREE_TYPE (arg1)))
1905            && !POINTER_TYPE_P (type)
1906            && int_fits_type_p (arg0, type))
1907     return type;
1908
1909   else if (TREE_CODE (arg1) == INTEGER_CST
1910            && (unsigned0 || !uns)
1911            && (TYPE_PRECISION (TREE_TYPE (arg0))
1912                < TYPE_PRECISION (result_type))
1913            && (type
1914                = c_common_signed_or_unsigned_type (unsigned0,
1915                                                    TREE_TYPE (arg0)))
1916            && !POINTER_TYPE_P (type)
1917            && int_fits_type_p (arg1, type))
1918     return type;
1919
1920   return result_type;
1921 }
1922
1923 /* Warns if the conversion of EXPR to TYPE may alter a value.
1924    This is a helper function for warnings_for_convert_and_check.  */
1925
1926 static void
1927 conversion_warning (tree type, tree expr)
1928 {
1929   bool give_warning = false;
1930
1931   int i;
1932   const int expr_num_operands = TREE_OPERAND_LENGTH (expr);
1933   tree expr_type = TREE_TYPE (expr);
1934
1935   if (!warn_conversion && !warn_sign_conversion)
1936     return;
1937
1938   /* If any operand is artificial, then this expression was generated
1939      by the compiler and we do not warn.  */
1940   for (i = 0; i < expr_num_operands; i++)
1941     {
1942       tree op = TREE_OPERAND (expr, i);
1943       if (op && DECL_P (op) && DECL_ARTIFICIAL (op))
1944         return;
1945     }
1946
1947   switch (TREE_CODE (expr))
1948     {
1949     case EQ_EXPR:
1950     case NE_EXPR:
1951     case LE_EXPR:
1952     case GE_EXPR:
1953     case LT_EXPR:
1954     case GT_EXPR:
1955     case TRUTH_ANDIF_EXPR:
1956     case TRUTH_ORIF_EXPR:
1957     case TRUTH_AND_EXPR:
1958     case TRUTH_OR_EXPR:
1959     case TRUTH_XOR_EXPR:
1960     case TRUTH_NOT_EXPR:
1961       /* Conversion from boolean to a signed:1 bit-field (which only
1962          can hold the values 0 and -1) doesn't lose information - but
1963          it does change the value.  */
1964       if (TYPE_PRECISION (type) == 1 && !TYPE_UNSIGNED (type))
1965         warning (OPT_Wconversion,
1966                  "conversion to %qT from boolean expression", type);
1967       return;
1968
1969     case REAL_CST:
1970     case INTEGER_CST:
1971
1972       /* Warn for real constant that is not an exact integer converted
1973          to integer type.  */
1974       if (TREE_CODE (expr_type) == REAL_TYPE
1975           && TREE_CODE (type) == INTEGER_TYPE)
1976         {
1977           if (!real_isinteger (TREE_REAL_CST_PTR (expr), TYPE_MODE (expr_type)))
1978             give_warning = true;
1979         }
1980       /* Warn for an integer constant that does not fit into integer type.  */
1981       else if (TREE_CODE (expr_type) == INTEGER_TYPE
1982                && TREE_CODE (type) == INTEGER_TYPE
1983                && !int_fits_type_p (expr, type))
1984         {
1985           if (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (expr_type)
1986               && tree_int_cst_sgn (expr) < 0)
1987             warning (OPT_Wsign_conversion,
1988                      "negative integer implicitly converted to unsigned type");
1989           else if (!TYPE_UNSIGNED (type) && TYPE_UNSIGNED (expr_type))
1990             warning (OPT_Wsign_conversion,  "conversion of unsigned constant "
1991                      "value to negative integer");
1992           else
1993             give_warning = true;
1994         }
1995       else if (TREE_CODE (type) == REAL_TYPE)
1996         {
1997           /* Warn for an integer constant that does not fit into real type.  */
1998           if (TREE_CODE (expr_type) == INTEGER_TYPE)
1999             {
2000               REAL_VALUE_TYPE a = real_value_from_int_cst (0, expr);
2001               if (!exact_real_truncate (TYPE_MODE (type), &a))
2002                 give_warning = true;
2003             }
2004           /* Warn for a real constant that does not fit into a smaller
2005              real type.  */
2006           else if (TREE_CODE (expr_type) == REAL_TYPE
2007                    && TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2008             {
2009               REAL_VALUE_TYPE a = TREE_REAL_CST (expr);
2010               if (!exact_real_truncate (TYPE_MODE (type), &a))
2011                 give_warning = true;
2012             }
2013         }
2014
2015       if (give_warning)
2016         warning (OPT_Wconversion,
2017                  "conversion to %qT alters %qT constant value",
2018                  type, expr_type);
2019
2020       return;
2021
2022     case COND_EXPR:
2023       {
2024         /* In case of COND_EXPR, if both operands are constants or
2025            COND_EXPR, then we do not care about the type of COND_EXPR,
2026            only about the conversion of each operand.  */
2027         tree op1 = TREE_OPERAND (expr, 1);
2028         tree op2 = TREE_OPERAND (expr, 2);
2029
2030         if ((TREE_CODE (op1) == REAL_CST || TREE_CODE (op1) == INTEGER_CST
2031              || TREE_CODE (op1) == COND_EXPR)
2032             && (TREE_CODE (op2) == REAL_CST || TREE_CODE (op2) == INTEGER_CST
2033                 || TREE_CODE (op2) == COND_EXPR))
2034           {
2035             conversion_warning (type, op1);
2036             conversion_warning (type, op2);
2037             return;
2038           }
2039         /* Fall through.  */
2040       }
2041
2042     default: /* 'expr' is not a constant.  */
2043
2044       /* Warn for real types converted to integer types.  */
2045       if (TREE_CODE (expr_type) == REAL_TYPE
2046           && TREE_CODE (type) == INTEGER_TYPE)
2047         give_warning = true;
2048
2049       else if (TREE_CODE (expr_type) == INTEGER_TYPE
2050                && TREE_CODE (type) == INTEGER_TYPE)
2051         {
2052           /* Don't warn about unsigned char y = 0xff, x = (int) y;  */
2053           expr = get_unwidened (expr, 0);
2054           expr_type = TREE_TYPE (expr);
2055
2056           /* Don't warn for short y; short x = ((int)y & 0xff);  */
2057           if (TREE_CODE (expr) == BIT_AND_EXPR
2058                 || TREE_CODE (expr) == BIT_IOR_EXPR
2059               || TREE_CODE (expr) == BIT_XOR_EXPR)
2060             {
2061               /* If both args were extended from a shortest type,
2062                  use that type if that is safe.  */
2063               expr_type = shorten_binary_op (expr_type,
2064                                              TREE_OPERAND (expr, 0),
2065                                              TREE_OPERAND (expr, 1),
2066                                              /* bitwise */1);
2067
2068               if (TREE_CODE (expr) == BIT_AND_EXPR)
2069                 {
2070                   tree op0 = TREE_OPERAND (expr, 0);
2071                   tree op1 = TREE_OPERAND (expr, 1);
2072                   bool unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
2073                   bool unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
2074
2075                   /* If one of the operands is a non-negative constant
2076                      that fits in the target type, then the type of the
2077                      other operand does not matter. */
2078                   if ((TREE_CODE (op0) == INTEGER_CST
2079                        && int_fits_type_p (op0, c_common_signed_type (type))
2080                        && int_fits_type_p (op0, c_common_unsigned_type (type)))
2081                       || (TREE_CODE (op1) == INTEGER_CST
2082                           && int_fits_type_p (op1, c_common_signed_type (type))
2083                           && int_fits_type_p (op1,
2084                                               c_common_unsigned_type (type))))
2085                     return;
2086                   /* If constant is unsigned and fits in the target
2087                      type, then the result will also fit.  */
2088                   else if ((TREE_CODE (op0) == INTEGER_CST
2089                             && unsigned0
2090                             && int_fits_type_p (op0, type))
2091                            || (TREE_CODE (op1) == INTEGER_CST
2092                                && unsigned1
2093                                && int_fits_type_p (op1, type)))
2094                     return;
2095                 }
2096             }
2097           /* Warn for integer types converted to smaller integer types.  */
2098           if (TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2099             give_warning = true;
2100
2101           /* When they are the same width but different signedness,
2102              then the value may change.  */
2103           else if ((TYPE_PRECISION (type) == TYPE_PRECISION (expr_type)
2104                     && TYPE_UNSIGNED (expr_type) != TYPE_UNSIGNED (type))
2105                    /* Even when converted to a bigger type, if the type is
2106                       unsigned but expr is signed, then negative values
2107                       will be changed.  */
2108                    || (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (expr_type)))
2109             warning (OPT_Wsign_conversion, "conversion to %qT from %qT "
2110                      "may change the sign of the result",
2111                      type, expr_type);
2112         }
2113
2114       /* Warn for integer types converted to real types if and only if
2115          all the range of values of the integer type cannot be
2116          represented by the real type.  */
2117       else if (TREE_CODE (expr_type) == INTEGER_TYPE
2118                && TREE_CODE (type) == REAL_TYPE)
2119         {
2120           tree type_low_bound = TYPE_MIN_VALUE (expr_type);
2121           tree type_high_bound = TYPE_MAX_VALUE (expr_type);
2122           REAL_VALUE_TYPE real_low_bound
2123             = real_value_from_int_cst (0, type_low_bound);
2124           REAL_VALUE_TYPE real_high_bound
2125             = real_value_from_int_cst (0, type_high_bound);
2126
2127           if (!exact_real_truncate (TYPE_MODE (type), &real_low_bound)
2128               || !exact_real_truncate (TYPE_MODE (type), &real_high_bound))
2129             give_warning = true;
2130         }
2131
2132       /* Warn for real types converted to smaller real types.  */
2133       else if (TREE_CODE (expr_type) == REAL_TYPE
2134                && TREE_CODE (type) == REAL_TYPE
2135                && TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2136         give_warning = true;
2137
2138
2139       if (give_warning)
2140         warning (OPT_Wconversion,
2141                  "conversion to %qT from %qT may alter its value",
2142                  type, expr_type);
2143     }
2144 }
2145
2146 /* Produce warnings after a conversion. RESULT is the result of
2147    converting EXPR to TYPE.  This is a helper function for
2148    convert_and_check and cp_convert_and_check.  */
2149
2150 void
2151 warnings_for_convert_and_check (tree type, tree expr, tree result)
2152 {
2153   if (TREE_CODE (expr) == INTEGER_CST
2154       && (TREE_CODE (type) == INTEGER_TYPE
2155           || TREE_CODE (type) == ENUMERAL_TYPE)
2156       && !int_fits_type_p (expr, type))
2157     {
2158       /* Do not diagnose overflow in a constant expression merely
2159          because a conversion overflowed.  */
2160       if (TREE_OVERFLOW (result))
2161         TREE_OVERFLOW (result) = TREE_OVERFLOW (expr);
2162
2163       if (TYPE_UNSIGNED (type))
2164         {
2165           /* This detects cases like converting -129 or 256 to
2166              unsigned char.  */
2167           if (!int_fits_type_p (expr, c_common_signed_type (type)))
2168             warning (OPT_Woverflow,
2169                      "large integer implicitly truncated to unsigned type");
2170           else
2171             conversion_warning (type, expr);
2172         }
2173       else if (!int_fits_type_p (expr, c_common_unsigned_type (type)))
2174         warning (OPT_Woverflow,
2175                  "overflow in implicit constant conversion");
2176       /* No warning for converting 0x80000000 to int.  */
2177       else if (pedantic
2178                && (TREE_CODE (TREE_TYPE (expr)) != INTEGER_TYPE
2179                    || TYPE_PRECISION (TREE_TYPE (expr))
2180                    != TYPE_PRECISION (type)))
2181         warning (OPT_Woverflow,
2182                  "overflow in implicit constant conversion");
2183
2184       else
2185         conversion_warning (type, expr);
2186     }
2187   else if ((TREE_CODE (result) == INTEGER_CST
2188             || TREE_CODE (result) == FIXED_CST) && TREE_OVERFLOW (result))
2189     warning (OPT_Woverflow,
2190              "overflow in implicit constant conversion");
2191   else
2192     conversion_warning (type, expr);
2193 }
2194
2195
2196 /* Convert EXPR to TYPE, warning about conversion problems with constants.
2197    Invoke this function on every expression that is converted implicitly,
2198    i.e. because of language rules and not because of an explicit cast.  */
2199
2200 tree
2201 convert_and_check (tree type, tree expr)
2202 {
2203   tree result;
2204   tree expr_for_warning;
2205
2206   /* Convert from a value with possible excess precision rather than
2207      via the semantic type, but do not warn about values not fitting
2208      exactly in the semantic type.  */
2209   if (TREE_CODE (expr) == EXCESS_PRECISION_EXPR)
2210     {
2211       tree orig_type = TREE_TYPE (expr);
2212       expr = TREE_OPERAND (expr, 0);
2213       expr_for_warning = convert (orig_type, expr);
2214       if (orig_type == type)
2215         return expr_for_warning;
2216     }
2217   else
2218     expr_for_warning = expr;
2219
2220   if (TREE_TYPE (expr) == type)
2221     return expr;
2222
2223   result = convert (type, expr);
2224
2225   if (!skip_evaluation && !TREE_OVERFLOW_P (expr) && result != error_mark_node)
2226     warnings_for_convert_and_check (type, expr_for_warning, result);
2227
2228   return result;
2229 }
2230 \f
2231 /* A node in a list that describes references to variables (EXPR), which are
2232    either read accesses if WRITER is zero, or write accesses, in which case
2233    WRITER is the parent of EXPR.  */
2234 struct tlist
2235 {
2236   struct tlist *next;
2237   tree expr, writer;
2238 };
2239
2240 /* Used to implement a cache the results of a call to verify_tree.  We only
2241    use this for SAVE_EXPRs.  */
2242 struct tlist_cache
2243 {
2244   struct tlist_cache *next;
2245   struct tlist *cache_before_sp;
2246   struct tlist *cache_after_sp;
2247   tree expr;
2248 };
2249
2250 /* Obstack to use when allocating tlist structures, and corresponding
2251    firstobj.  */
2252 static struct obstack tlist_obstack;
2253 static char *tlist_firstobj = 0;
2254
2255 /* Keep track of the identifiers we've warned about, so we can avoid duplicate
2256    warnings.  */
2257 static struct tlist *warned_ids;
2258 /* SAVE_EXPRs need special treatment.  We process them only once and then
2259    cache the results.  */
2260 static struct tlist_cache *save_expr_cache;
2261
2262 static void add_tlist (struct tlist **, struct tlist *, tree, int);
2263 static void merge_tlist (struct tlist **, struct tlist *, int);
2264 static void verify_tree (tree, struct tlist **, struct tlist **, tree);
2265 static int warning_candidate_p (tree);
2266 static bool candidate_equal_p (const_tree, const_tree);
2267 static void warn_for_collisions (struct tlist *);
2268 static void warn_for_collisions_1 (tree, tree, struct tlist *, int);
2269 static struct tlist *new_tlist (struct tlist *, tree, tree);
2270
2271 /* Create a new struct tlist and fill in its fields.  */
2272 static struct tlist *
2273 new_tlist (struct tlist *next, tree t, tree writer)
2274 {
2275   struct tlist *l;
2276   l = XOBNEW (&tlist_obstack, struct tlist);
2277   l->next = next;
2278   l->expr = t;
2279   l->writer = writer;
2280   return l;
2281 }
2282
2283 /* Add duplicates of the nodes found in ADD to the list *TO.  If EXCLUDE_WRITER
2284    is nonnull, we ignore any node we find which has a writer equal to it.  */
2285
2286 static void
2287 add_tlist (struct tlist **to, struct tlist *add, tree exclude_writer, int copy)
2288 {
2289   while (add)
2290     {
2291       struct tlist *next = add->next;
2292       if (!copy)
2293         add->next = *to;
2294       if (!exclude_writer || !candidate_equal_p (add->writer, exclude_writer))
2295         *to = copy ? new_tlist (*to, add->expr, add->writer) : add;
2296       add = next;
2297     }
2298 }
2299
2300 /* Merge the nodes of ADD into TO.  This merging process is done so that for
2301    each variable that already exists in TO, no new node is added; however if
2302    there is a write access recorded in ADD, and an occurrence on TO is only
2303    a read access, then the occurrence in TO will be modified to record the
2304    write.  */
2305
2306 static void
2307 merge_tlist (struct tlist **to, struct tlist *add, int copy)
2308 {
2309   struct tlist **end = to;
2310
2311   while (*end)
2312     end = &(*end)->next;
2313
2314   while (add)
2315     {
2316       int found = 0;
2317       struct tlist *tmp2;
2318       struct tlist *next = add->next;
2319
2320       for (tmp2 = *to; tmp2; tmp2 = tmp2->next)
2321         if (candidate_equal_p (tmp2->expr, add->expr))
2322           {
2323             found = 1;
2324             if (!tmp2->writer)
2325               tmp2->writer = add->writer;
2326           }
2327       if (!found)
2328         {
2329           *end = copy ? add : new_tlist (NULL, add->expr, add->writer);
2330           end = &(*end)->next;
2331           *end = 0;
2332         }
2333       add = next;
2334     }
2335 }
2336
2337 /* WRITTEN is a variable, WRITER is its parent.  Warn if any of the variable
2338    references in list LIST conflict with it, excluding reads if ONLY writers
2339    is nonzero.  */
2340
2341 static void
2342 warn_for_collisions_1 (tree written, tree writer, struct tlist *list,
2343                        int only_writes)
2344 {
2345   struct tlist *tmp;
2346
2347   /* Avoid duplicate warnings.  */
2348   for (tmp = warned_ids; tmp; tmp = tmp->next)
2349     if (candidate_equal_p (tmp->expr, written))
2350       return;
2351
2352   while (list)
2353     {
2354       if (candidate_equal_p (list->expr, written)
2355           && !candidate_equal_p (list->writer, writer)
2356           && (!only_writes || list->writer))
2357         {
2358           warned_ids = new_tlist (warned_ids, written, NULL_TREE);
2359           warning_at (EXPR_HAS_LOCATION (writer)
2360                       ? EXPR_LOCATION (writer) : input_location,
2361                       OPT_Wsequence_point, "operation on %qE may be undefined",
2362                       list->expr);
2363         }
2364       list = list->next;
2365     }
2366 }
2367
2368 /* Given a list LIST of references to variables, find whether any of these
2369    can cause conflicts due to missing sequence points.  */
2370
2371 static void
2372 warn_for_collisions (struct tlist *list)
2373 {
2374   struct tlist *tmp;
2375
2376   for (tmp = list; tmp; tmp = tmp->next)
2377     {
2378       if (tmp->writer)
2379         warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0);
2380     }
2381 }
2382
2383 /* Return nonzero if X is a tree that can be verified by the sequence point
2384    warnings.  */
2385 static int
2386 warning_candidate_p (tree x)
2387 {
2388   /* !VOID_TYPE_P (TREE_TYPE (x)) is workaround for cp/tree.c
2389      (lvalue_p) crash on TRY/CATCH. */
2390   return !(DECL_P (x) && DECL_ARTIFICIAL (x))
2391     && TREE_TYPE (x) && !VOID_TYPE_P (TREE_TYPE (x)) && lvalue_p (x);
2392 }
2393
2394 /* Return nonzero if X and Y appear to be the same candidate (or NULL) */
2395 static bool
2396 candidate_equal_p (const_tree x, const_tree y)
2397 {
2398   return (x == y) || (x && y && operand_equal_p (x, y, 0));
2399 }
2400
2401 /* Walk the tree X, and record accesses to variables.  If X is written by the
2402    parent tree, WRITER is the parent.
2403    We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP.  If this
2404    expression or its only operand forces a sequence point, then everything up
2405    to the sequence point is stored in PBEFORE_SP.  Everything else gets stored
2406    in PNO_SP.
2407    Once we return, we will have emitted warnings if any subexpression before
2408    such a sequence point could be undefined.  On a higher level, however, the
2409    sequence point may not be relevant, and we'll merge the two lists.
2410
2411    Example: (b++, a) + b;
2412    The call that processes the COMPOUND_EXPR will store the increment of B
2413    in PBEFORE_SP, and the use of A in PNO_SP.  The higher-level call that
2414    processes the PLUS_EXPR will need to merge the two lists so that
2415    eventually, all accesses end up on the same list (and we'll warn about the
2416    unordered subexpressions b++ and b.
2417
2418    A note on merging.  If we modify the former example so that our expression
2419    becomes
2420      (b++, b) + a
2421    care must be taken not simply to add all three expressions into the final
2422    PNO_SP list.  The function merge_tlist takes care of that by merging the
2423    before-SP list of the COMPOUND_EXPR into its after-SP list in a special
2424    way, so that no more than one access to B is recorded.  */
2425
2426 static void
2427 verify_tree (tree x, struct tlist **pbefore_sp, struct tlist **pno_sp,
2428              tree writer)
2429 {
2430   struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3;
2431   enum tree_code code;
2432   enum tree_code_class cl;
2433
2434   /* X may be NULL if it is the operand of an empty statement expression
2435      ({ }).  */
2436   if (x == NULL)
2437     return;
2438
2439  restart:
2440   code = TREE_CODE (x);
2441   cl = TREE_CODE_CLASS (code);
2442
2443   if (warning_candidate_p (x))
2444     *pno_sp = new_tlist (*pno_sp, x, writer);
2445
2446   switch (code)
2447     {
2448     case CONSTRUCTOR:
2449       return;
2450
2451     case COMPOUND_EXPR:
2452     case TRUTH_ANDIF_EXPR:
2453     case TRUTH_ORIF_EXPR:
2454       tmp_before = tmp_nosp = tmp_list3 = 0;
2455       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
2456       warn_for_collisions (tmp_nosp);
2457       merge_tlist (pbefore_sp, tmp_before, 0);
2458       merge_tlist (pbefore_sp, tmp_nosp, 0);
2459       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE);
2460       merge_tlist (pbefore_sp, tmp_list3, 0);
2461       return;
2462
2463     case COND_EXPR:
2464       tmp_before = tmp_list2 = 0;
2465       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE);
2466       warn_for_collisions (tmp_list2);
2467       merge_tlist (pbefore_sp, tmp_before, 0);
2468       merge_tlist (pbefore_sp, tmp_list2, 1);
2469
2470       tmp_list3 = tmp_nosp = 0;
2471       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE);
2472       warn_for_collisions (tmp_nosp);
2473       merge_tlist (pbefore_sp, tmp_list3, 0);
2474
2475       tmp_list3 = tmp_list2 = 0;
2476       verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE);
2477       warn_for_collisions (tmp_list2);
2478       merge_tlist (pbefore_sp, tmp_list3, 0);
2479       /* Rather than add both tmp_nosp and tmp_list2, we have to merge the
2480          two first, to avoid warning for (a ? b++ : b++).  */
2481       merge_tlist (&tmp_nosp, tmp_list2, 0);
2482       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2483       return;
2484
2485     case PREDECREMENT_EXPR:
2486     case PREINCREMENT_EXPR:
2487     case POSTDECREMENT_EXPR:
2488     case POSTINCREMENT_EXPR:
2489       verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x);
2490       return;
2491
2492     case MODIFY_EXPR:
2493       tmp_before = tmp_nosp = tmp_list3 = 0;
2494       verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE);
2495       verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x);
2496       /* Expressions inside the LHS are not ordered wrt. the sequence points
2497          in the RHS.  Example:
2498            *a = (a++, 2)
2499          Despite the fact that the modification of "a" is in the before_sp
2500          list (tmp_before), it conflicts with the use of "a" in the LHS.
2501          We can handle this by adding the contents of tmp_list3
2502          to those of tmp_before, and redoing the collision warnings for that
2503          list.  */
2504       add_tlist (&tmp_before, tmp_list3, x, 1);
2505       warn_for_collisions (tmp_before);
2506       /* Exclude the LHS itself here; we first have to merge it into the
2507          tmp_nosp list.  This is done to avoid warning for "a = a"; if we
2508          didn't exclude the LHS, we'd get it twice, once as a read and once
2509          as a write.  */
2510       add_tlist (pno_sp, tmp_list3, x, 0);
2511       warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1);
2512
2513       merge_tlist (pbefore_sp, tmp_before, 0);
2514       if (warning_candidate_p (TREE_OPERAND (x, 0)))
2515         merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0);
2516       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1);
2517       return;
2518
2519     case CALL_EXPR:
2520       /* We need to warn about conflicts among arguments and conflicts between
2521          args and the function address.  Side effects of the function address,
2522          however, are not ordered by the sequence point of the call.  */
2523       {
2524         call_expr_arg_iterator iter;
2525         tree arg;
2526         tmp_before = tmp_nosp = 0;
2527         verify_tree (CALL_EXPR_FN (x), &tmp_before, &tmp_nosp, NULL_TREE);
2528         FOR_EACH_CALL_EXPR_ARG (arg, iter, x)
2529           {
2530             tmp_list2 = tmp_list3 = 0;
2531             verify_tree (arg, &tmp_list2, &tmp_list3, NULL_TREE);
2532             merge_tlist (&tmp_list3, tmp_list2, 0);
2533             add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0);
2534           }
2535         add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0);
2536         warn_for_collisions (tmp_before);
2537         add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0);
2538         return;
2539       }
2540
2541     case TREE_LIST:
2542       /* Scan all the list, e.g. indices of multi dimensional array.  */
2543       while (x)
2544         {
2545           tmp_before = tmp_nosp = 0;
2546           verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE);
2547           merge_tlist (&tmp_nosp, tmp_before, 0);
2548           add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2549           x = TREE_CHAIN (x);
2550         }
2551       return;
2552
2553     case SAVE_EXPR:
2554       {
2555         struct tlist_cache *t;
2556         for (t = save_expr_cache; t; t = t->next)
2557           if (candidate_equal_p (t->expr, x))
2558             break;
2559
2560         if (!t)
2561           {
2562             t = XOBNEW (&tlist_obstack, struct tlist_cache);
2563             t->next = save_expr_cache;
2564             t->expr = x;
2565             save_expr_cache = t;
2566
2567             tmp_before = tmp_nosp = 0;
2568             verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
2569             warn_for_collisions (tmp_nosp);
2570
2571             tmp_list3 = 0;
2572             while (tmp_nosp)
2573               {
2574                 struct tlist *t = tmp_nosp;
2575                 tmp_nosp = t->next;
2576                 merge_tlist (&tmp_list3, t, 0);
2577               }
2578             t->cache_before_sp = tmp_before;
2579             t->cache_after_sp = tmp_list3;
2580           }
2581         merge_tlist (pbefore_sp, t->cache_before_sp, 1);
2582         add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1);
2583         return;
2584       }
2585
2586     case ADDR_EXPR:
2587       x = TREE_OPERAND (x, 0);
2588       if (DECL_P (x))
2589         return;
2590       writer = 0;
2591       goto restart;
2592
2593     default:
2594       /* For other expressions, simply recurse on their operands.
2595          Manual tail recursion for unary expressions.
2596          Other non-expressions need not be processed.  */
2597       if (cl == tcc_unary)
2598         {
2599           x = TREE_OPERAND (x, 0);
2600           writer = 0;
2601           goto restart;
2602         }
2603       else if (IS_EXPR_CODE_CLASS (cl))
2604         {
2605           int lp;
2606           int max = TREE_OPERAND_LENGTH (x);
2607           for (lp = 0; lp < max; lp++)
2608             {
2609               tmp_before = tmp_nosp = 0;
2610               verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, 0);
2611               merge_tlist (&tmp_nosp, tmp_before, 0);
2612               add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2613             }
2614         }
2615       return;
2616     }
2617 }
2618
2619 /* Try to warn for undefined behavior in EXPR due to missing sequence
2620    points.  */
2621
2622 void
2623 verify_sequence_points (tree expr)
2624 {
2625   struct tlist *before_sp = 0, *after_sp = 0;
2626
2627   warned_ids = 0;
2628   save_expr_cache = 0;
2629   if (tlist_firstobj == 0)
2630     {
2631       gcc_obstack_init (&tlist_obstack);
2632       tlist_firstobj = (char *) obstack_alloc (&tlist_obstack, 0);
2633     }
2634
2635   verify_tree (expr, &before_sp, &after_sp, 0);
2636   warn_for_collisions (after_sp);
2637   obstack_free (&tlist_obstack, tlist_firstobj);
2638 }
2639 \f
2640 /* Validate the expression after `case' and apply default promotions.  */
2641
2642 static tree
2643 check_case_value (tree value)
2644 {
2645   if (value == NULL_TREE)
2646     return value;
2647
2648   /* ??? Can we ever get nops here for a valid case value?  We
2649      shouldn't for C.  */
2650   STRIP_TYPE_NOPS (value);
2651   /* In C++, the following is allowed:
2652
2653        const int i = 3;
2654        switch (...) { case i: ... }
2655
2656      So, we try to reduce the VALUE to a constant that way.  */
2657   if (c_dialect_cxx ())
2658     {
2659       value = decl_constant_value (value);
2660       STRIP_TYPE_NOPS (value);
2661       value = fold (value);
2662     }
2663
2664   if (TREE_CODE (value) == INTEGER_CST)
2665     /* Promote char or short to int.  */
2666     value = perform_integral_promotions (value);
2667   else if (value != error_mark_node)
2668     {
2669       error ("case label does not reduce to an integer constant");
2670       value = error_mark_node;
2671     }
2672
2673   constant_expression_warning (value);
2674
2675   return value;
2676 }
2677 \f
2678 /* See if the case values LOW and HIGH are in the range of the original
2679    type (i.e. before the default conversion to int) of the switch testing
2680    expression.
2681    TYPE is the promoted type of the testing expression, and ORIG_TYPE is
2682    the type before promoting it.  CASE_LOW_P is a pointer to the lower
2683    bound of the case label, and CASE_HIGH_P is the upper bound or NULL
2684    if the case is not a case range.
2685    The caller has to make sure that we are not called with NULL for
2686    CASE_LOW_P (i.e. the default case).
2687    Returns true if the case label is in range of ORIG_TYPE (saturated or
2688    untouched) or false if the label is out of range.  */
2689
2690 static bool
2691 check_case_bounds (tree type, tree orig_type,
2692                    tree *case_low_p, tree *case_high_p)
2693 {
2694   tree min_value, max_value;
2695   tree case_low = *case_low_p;
2696   tree case_high = case_high_p ? *case_high_p : case_low;
2697
2698   /* If there was a problem with the original type, do nothing.  */
2699   if (orig_type == error_mark_node)
2700     return true;
2701
2702   min_value = TYPE_MIN_VALUE (orig_type);
2703   max_value = TYPE_MAX_VALUE (orig_type);
2704
2705   /* Case label is less than minimum for type.  */
2706   if (tree_int_cst_compare (case_low, min_value) < 0
2707       && tree_int_cst_compare (case_high, min_value) < 0)
2708     {
2709       warning (0, "case label value is less than minimum value for type");
2710       return false;
2711     }
2712
2713   /* Case value is greater than maximum for type.  */
2714   if (tree_int_cst_compare (case_low, max_value) > 0
2715       && tree_int_cst_compare (case_high, max_value) > 0)
2716     {
2717       warning (0, "case label value exceeds maximum value for type");
2718       return false;
2719     }
2720
2721   /* Saturate lower case label value to minimum.  */
2722   if (tree_int_cst_compare (case_high, min_value) >= 0
2723       && tree_int_cst_compare (case_low, min_value) < 0)
2724     {
2725       warning (0, "lower value in case label range"
2726                " less than minimum value for type");
2727       case_low = min_value;
2728     }
2729
2730   /* Saturate upper case label value to maximum.  */
2731   if (tree_int_cst_compare (case_low, max_value) <= 0
2732       && tree_int_cst_compare (case_high, max_value) > 0)
2733     {
2734       warning (0, "upper value in case label range"
2735                " exceeds maximum value for type");
2736       case_high = max_value;
2737     }
2738
2739   if (*case_low_p != case_low)
2740     *case_low_p = convert (type, case_low);
2741   if (case_high_p && *case_high_p != case_high)
2742     *case_high_p = convert (type, case_high);
2743
2744   return true;
2745 }
2746 \f
2747 /* Return an integer type with BITS bits of precision,
2748    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
2749
2750 tree
2751 c_common_type_for_size (unsigned int bits, int unsignedp)
2752 {
2753   if (bits == TYPE_PRECISION (integer_type_node))
2754     return unsignedp ? unsigned_type_node : integer_type_node;
2755
2756   if (bits == TYPE_PRECISION (signed_char_type_node))
2757     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2758
2759   if (bits == TYPE_PRECISION (short_integer_type_node))
2760     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2761
2762   if (bits == TYPE_PRECISION (long_integer_type_node))
2763     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2764
2765   if (bits == TYPE_PRECISION (long_long_integer_type_node))
2766     return (unsignedp ? long_long_unsigned_type_node
2767             : long_long_integer_type_node);
2768
2769   if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
2770     return (unsignedp ? widest_unsigned_literal_type_node
2771             : widest_integer_literal_type_node);
2772
2773   if (bits <= TYPE_PRECISION (intQI_type_node))
2774     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2775
2776   if (bits <= TYPE_PRECISION (intHI_type_node))
2777     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2778
2779   if (bits <= TYPE_PRECISION (intSI_type_node))
2780     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2781
2782   if (bits <= TYPE_PRECISION (intDI_type_node))
2783     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2784
2785   return 0;
2786 }
2787
2788 /* Return a fixed-point type that has at least IBIT ibits and FBIT fbits
2789    that is unsigned if UNSIGNEDP is nonzero, otherwise signed;
2790    and saturating if SATP is nonzero, otherwise not saturating.  */
2791
2792 tree
2793 c_common_fixed_point_type_for_size (unsigned int ibit, unsigned int fbit,
2794                                     int unsignedp, int satp)
2795 {
2796   enum machine_mode mode;
2797   if (ibit == 0)
2798     mode = unsignedp ? UQQmode : QQmode;
2799   else
2800     mode = unsignedp ? UHAmode : HAmode;
2801
2802   for (; mode != VOIDmode; mode = GET_MODE_WIDER_MODE (mode))
2803     if (GET_MODE_IBIT (mode) >= ibit && GET_MODE_FBIT (mode) >= fbit)
2804       break;
2805
2806   if (mode == VOIDmode || !targetm.scalar_mode_supported_p (mode))
2807     {
2808       sorry ("GCC cannot support operators with integer types and "
2809              "fixed-point types that have too many integral and "
2810              "fractional bits together");
2811       return 0;
2812     }
2813
2814   return c_common_type_for_mode (mode, satp);
2815 }
2816
2817 /* Used for communication between c_common_type_for_mode and
2818    c_register_builtin_type.  */
2819 static GTY(()) tree registered_builtin_types;
2820
2821 /* Return a data type that has machine mode MODE.
2822    If the mode is an integer,
2823    then UNSIGNEDP selects between signed and unsigned types.
2824    If the mode is a fixed-point mode,
2825    then UNSIGNEDP selects between saturating and nonsaturating types.  */
2826
2827 tree
2828 c_common_type_for_mode (enum machine_mode mode, int unsignedp)
2829 {
2830   tree t;
2831
2832   if (mode == TYPE_MODE (integer_type_node))
2833     return unsignedp ? unsigned_type_node : integer_type_node;
2834
2835   if (mode == TYPE_MODE (signed_char_type_node))
2836     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2837
2838   if (mode == TYPE_MODE (short_integer_type_node))
2839     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2840
2841   if (mode == TYPE_MODE (long_integer_type_node))
2842     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2843
2844   if (mode == TYPE_MODE (long_long_integer_type_node))
2845     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
2846
2847   if (mode == TYPE_MODE (widest_integer_literal_type_node))
2848     return unsignedp ? widest_unsigned_literal_type_node
2849                      : widest_integer_literal_type_node;
2850
2851   if (mode == QImode)
2852     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2853
2854   if (mode == HImode)
2855     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2856
2857   if (mode == SImode)
2858     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2859
2860   if (mode == DImode)
2861     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2862
2863 #if HOST_BITS_PER_WIDE_INT >= 64
2864   if (mode == TYPE_MODE (intTI_type_node))
2865     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
2866 #endif
2867
2868   if (mode == TYPE_MODE (float_type_node))
2869     return float_type_node;
2870
2871   if (mode == TYPE_MODE (double_type_node))
2872     return double_type_node;
2873
2874   if (mode == TYPE_MODE (long_double_type_node))
2875     return long_double_type_node;
2876
2877   if (mode == TYPE_MODE (void_type_node))
2878     return void_type_node;
2879
2880   if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
2881     return (unsignedp
2882             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2883             : make_signed_type (GET_MODE_PRECISION (mode)));
2884
2885   if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
2886     return (unsignedp
2887             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2888             : make_signed_type (GET_MODE_PRECISION (mode)));
2889
2890   if (COMPLEX_MODE_P (mode))
2891     {
2892       enum machine_mode inner_mode;
2893       tree inner_type;
2894
2895       if (mode == TYPE_MODE (complex_float_type_node))
2896         return complex_float_type_node;
2897       if (mode == TYPE_MODE (complex_double_type_node))
2898         return complex_double_type_node;
2899       if (mode == TYPE_MODE (complex_long_double_type_node))
2900         return complex_long_double_type_node;
2901
2902       if (mode == TYPE_MODE (complex_integer_type_node) && !unsignedp)
2903         return complex_integer_type_node;
2904
2905       inner_mode = GET_MODE_INNER (mode);
2906       inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2907       if (inner_type != NULL_TREE)
2908         return build_complex_type (inner_type);
2909     }
2910   else if (VECTOR_MODE_P (mode))
2911     {
2912       enum machine_mode inner_mode = GET_MODE_INNER (mode);
2913       tree inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2914       if (inner_type != NULL_TREE)
2915         return build_vector_type_for_mode (inner_type, mode);
2916     }
2917
2918   if (mode == TYPE_MODE (dfloat32_type_node))
2919     return dfloat32_type_node;
2920   if (mode == TYPE_MODE (dfloat64_type_node))
2921     return dfloat64_type_node;
2922   if (mode == TYPE_MODE (dfloat128_type_node))
2923     return dfloat128_type_node;
2924
2925   if (ALL_SCALAR_FIXED_POINT_MODE_P (mode))
2926     {
2927       if (mode == TYPE_MODE (short_fract_type_node))
2928         return unsignedp ? sat_short_fract_type_node : short_fract_type_node;
2929       if (mode == TYPE_MODE (fract_type_node))
2930         return unsignedp ? sat_fract_type_node : fract_type_node;
2931       if (mode == TYPE_MODE (long_fract_type_node))
2932         return unsignedp ? sat_long_fract_type_node : long_fract_type_node;
2933       if (mode == TYPE_MODE (long_long_fract_type_node))
2934         return unsignedp ? sat_long_long_fract_type_node
2935                          : long_long_fract_type_node;
2936
2937       if (mode == TYPE_MODE (unsigned_short_fract_type_node))
2938         return unsignedp ? sat_unsigned_short_fract_type_node
2939                          : unsigned_short_fract_type_node;
2940       if (mode == TYPE_MODE (unsigned_fract_type_node))
2941         return unsignedp ? sat_unsigned_fract_type_node
2942                          : unsigned_fract_type_node;
2943       if (mode == TYPE_MODE (unsigned_long_fract_type_node))
2944         return unsignedp ? sat_unsigned_long_fract_type_node
2945                          : unsigned_long_fract_type_node;
2946       if (mode == TYPE_MODE (unsigned_long_long_fract_type_node))
2947         return unsignedp ? sat_unsigned_long_long_fract_type_node
2948                          : unsigned_long_long_fract_type_node;
2949
2950       if (mode == TYPE_MODE (short_accum_type_node))
2951         return unsignedp ? sat_short_accum_type_node : short_accum_type_node;
2952       if (mode == TYPE_MODE (accum_type_node))
2953         return unsignedp ? sat_accum_type_node : accum_type_node;
2954       if (mode == TYPE_MODE (long_accum_type_node))
2955         return unsignedp ? sat_long_accum_type_node : long_accum_type_node;
2956       if (mode == TYPE_MODE (long_long_accum_type_node))
2957         return unsignedp ? sat_long_long_accum_type_node
2958                          : long_long_accum_type_node;
2959
2960       if (mode == TYPE_MODE (unsigned_short_accum_type_node))
2961         return unsignedp ? sat_unsigned_short_accum_type_node
2962                          : unsigned_short_accum_type_node;
2963       if (mode == TYPE_MODE (unsigned_accum_type_node))
2964         return unsignedp ? sat_unsigned_accum_type_node
2965                          : unsigned_accum_type_node;
2966       if (mode == TYPE_MODE (unsigned_long_accum_type_node))
2967         return unsignedp ? sat_unsigned_long_accum_type_node
2968                          : unsigned_long_accum_type_node;
2969       if (mode == TYPE_MODE (unsigned_long_long_accum_type_node))
2970         return unsignedp ? sat_unsigned_long_long_accum_type_node
2971                          : unsigned_long_long_accum_type_node;
2972
2973       if (mode == QQmode)
2974         return unsignedp ? sat_qq_type_node : qq_type_node;
2975       if (mode == HQmode)
2976         return unsignedp ? sat_hq_type_node : hq_type_node;
2977       if (mode == SQmode)
2978         return unsignedp ? sat_sq_type_node : sq_type_node;
2979       if (mode == DQmode)
2980         return unsignedp ? sat_dq_type_node : dq_type_node;
2981       if (mode == TQmode)
2982         return unsignedp ? sat_tq_type_node : tq_type_node;
2983
2984       if (mode == UQQmode)
2985         return unsignedp ? sat_uqq_type_node : uqq_type_node;
2986       if (mode == UHQmode)
2987         return unsignedp ? sat_uhq_type_node : uhq_type_node;
2988       if (mode == USQmode)
2989         return unsignedp ? sat_usq_type_node : usq_type_node;
2990       if (mode == UDQmode)
2991         return unsignedp ? sat_udq_type_node : udq_type_node;
2992       if (mode == UTQmode)
2993         return unsignedp ? sat_utq_type_node : utq_type_node;
2994
2995       if (mode == HAmode)
2996         return unsignedp ? sat_ha_type_node : ha_type_node;
2997       if (mode == SAmode)
2998         return unsignedp ? sat_sa_type_node : sa_type_node;
2999       if (mode == DAmode)
3000         return unsignedp ? sat_da_type_node : da_type_node;
3001       if (mode == TAmode)
3002         return unsignedp ? sat_ta_type_node : ta_type_node;
3003
3004       if (mode == UHAmode)
3005         return unsignedp ? sat_uha_type_node : uha_type_node;
3006       if (mode == USAmode)
3007         return unsignedp ? sat_usa_type_node : usa_type_node;
3008       if (mode == UDAmode)
3009         return unsignedp ? sat_uda_type_node : uda_type_node;
3010       if (mode == UTAmode)
3011         return unsignedp ? sat_uta_type_node : uta_type_node;
3012     }
3013
3014   for (t = registered_builtin_types; t; t = TREE_CHAIN (t))
3015     if (TYPE_MODE (TREE_VALUE (t)) == mode)
3016       return TREE_VALUE (t);
3017
3018   return 0;
3019 }
3020
3021 tree
3022 c_common_unsigned_type (tree type)
3023 {
3024   return c_common_signed_or_unsigned_type (1, type);
3025 }
3026
3027 /* Return a signed type the same as TYPE in other respects.  */
3028
3029 tree
3030 c_common_signed_type (tree type)
3031 {
3032   return c_common_signed_or_unsigned_type (0, type);
3033 }
3034
3035 /* Return a type the same as TYPE except unsigned or
3036    signed according to UNSIGNEDP.  */
3037
3038 tree
3039 c_common_signed_or_unsigned_type (int unsignedp, tree type)
3040 {
3041   tree type1;
3042
3043   /* This block of code emulates the behavior of the old
3044      c_common_unsigned_type. In particular, it returns
3045      long_unsigned_type_node if passed a long, even when a int would
3046      have the same size. This is necessary for warnings to work
3047      correctly in archs where sizeof(int) == sizeof(long) */
3048
3049   type1 = TYPE_MAIN_VARIANT (type);
3050   if (type1 == signed_char_type_node || type1 == char_type_node || type1 == unsigned_char_type_node)
3051     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3052   if (type1 == integer_type_node || type1 == unsigned_type_node)
3053     return unsignedp ? unsigned_type_node : integer_type_node;
3054   if (type1 == short_integer_type_node || type1 == short_unsigned_type_node)
3055     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3056   if (type1 == long_integer_type_node || type1 == long_unsigned_type_node)
3057     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3058   if (type1 == long_long_integer_type_node || type1 == long_long_unsigned_type_node)
3059     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
3060   if (type1 == widest_integer_literal_type_node || type1 == widest_unsigned_literal_type_node)
3061     return unsignedp ? widest_unsigned_literal_type_node : widest_integer_literal_type_node;
3062 #if HOST_BITS_PER_WIDE_INT >= 64
3063   if (type1 == intTI_type_node || type1 == unsigned_intTI_type_node)
3064     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
3065 #endif
3066   if (type1 == intDI_type_node || type1 == unsigned_intDI_type_node)
3067     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
3068   if (type1 == intSI_type_node || type1 == unsigned_intSI_type_node)
3069     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
3070   if (type1 == intHI_type_node || type1 == unsigned_intHI_type_node)
3071     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
3072   if (type1 == intQI_type_node || type1 == unsigned_intQI_type_node)
3073     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
3074
3075 #define C_COMMON_FIXED_TYPES(NAME)          \
3076   if (type1 == short_ ## NAME ## _type_node \
3077       || type1 == unsigned_short_ ## NAME ## _type_node) \
3078     return unsignedp ? unsigned_short_ ## NAME ## _type_node \
3079                      : short_ ## NAME ## _type_node; \
3080   if (type1 == NAME ## _type_node \
3081       || type1 == unsigned_ ## NAME ## _type_node) \
3082     return unsignedp ? unsigned_ ## NAME ## _type_node \
3083                      : NAME ## _type_node; \
3084   if (type1 == long_ ## NAME ## _type_node \
3085       || type1 == unsigned_long_ ## NAME ## _type_node) \
3086     return unsignedp ? unsigned_long_ ## NAME ## _type_node \
3087                      : long_ ## NAME ## _type_node; \
3088   if (type1 == long_long_ ## NAME ## _type_node \
3089       || type1 == unsigned_long_long_ ## NAME ## _type_node) \
3090     return unsignedp ? unsigned_long_long_ ## NAME ## _type_node \
3091                      : long_long_ ## NAME ## _type_node;
3092
3093 #define C_COMMON_FIXED_MODE_TYPES(NAME) \
3094   if (type1 == NAME ## _type_node \
3095       || type1 == u ## NAME ## _type_node) \
3096     return unsignedp ? u ## NAME ## _type_node \
3097                      : NAME ## _type_node;
3098
3099 #define C_COMMON_FIXED_TYPES_SAT(NAME) \
3100   if (type1 == sat_ ## short_ ## NAME ## _type_node \
3101       || type1 == sat_ ## unsigned_short_ ## NAME ## _type_node) \
3102     return unsignedp ? sat_ ## unsigned_short_ ## NAME ## _type_node \
3103                      : sat_ ## short_ ## NAME ## _type_node; \
3104   if (type1 == sat_ ## NAME ## _type_node \
3105       || type1 == sat_ ## unsigned_ ## NAME ## _type_node) \
3106     return unsignedp ? sat_ ## unsigned_ ## NAME ## _type_node \
3107                      : sat_ ## NAME ## _type_node; \
3108   if (type1 == sat_ ## long_ ## NAME ## _type_node \
3109       || type1 == sat_ ## unsigned_long_ ## NAME ## _type_node) \
3110     return unsignedp ? sat_ ## unsigned_long_ ## NAME ## _type_node \
3111                      : sat_ ## long_ ## NAME ## _type_node; \
3112   if (type1 == sat_ ## long_long_ ## NAME ## _type_node \
3113       || type1 == sat_ ## unsigned_long_long_ ## NAME ## _type_node) \
3114     return unsignedp ? sat_ ## unsigned_long_long_ ## NAME ## _type_node \
3115                      : sat_ ## long_long_ ## NAME ## _type_node;
3116
3117 #define C_COMMON_FIXED_MODE_TYPES_SAT(NAME)     \
3118   if (type1 == sat_ ## NAME ## _type_node \
3119       || type1 == sat_ ## u ## NAME ## _type_node) \
3120     return unsignedp ? sat_ ## u ## NAME ## _type_node \
3121                      : sat_ ## NAME ## _type_node;
3122
3123   C_COMMON_FIXED_TYPES (fract);
3124   C_COMMON_FIXED_TYPES_SAT (fract);
3125   C_COMMON_FIXED_TYPES (accum);
3126   C_COMMON_FIXED_TYPES_SAT (accum);
3127
3128   C_COMMON_FIXED_MODE_TYPES (qq);
3129   C_COMMON_FIXED_MODE_TYPES (hq);
3130   C_COMMON_FIXED_MODE_TYPES (sq);
3131   C_COMMON_FIXED_MODE_TYPES (dq);
3132   C_COMMON_FIXED_MODE_TYPES (tq);
3133   C_COMMON_FIXED_MODE_TYPES_SAT (qq);
3134   C_COMMON_FIXED_MODE_TYPES_SAT (hq);
3135   C_COMMON_FIXED_MODE_TYPES_SAT (sq);
3136   C_COMMON_FIXED_MODE_TYPES_SAT (dq);
3137   C_COMMON_FIXED_MODE_TYPES_SAT (tq);
3138   C_COMMON_FIXED_MODE_TYPES (ha);
3139   C_COMMON_FIXED_MODE_TYPES (sa);
3140   C_COMMON_FIXED_MODE_TYPES (da);
3141   C_COMMON_FIXED_MODE_TYPES (ta);
3142   C_COMMON_FIXED_MODE_TYPES_SAT (ha);
3143   C_COMMON_FIXED_MODE_TYPES_SAT (sa);
3144   C_COMMON_FIXED_MODE_TYPES_SAT (da);
3145   C_COMMON_FIXED_MODE_TYPES_SAT (ta);
3146
3147   /* For ENUMERAL_TYPEs in C++, must check the mode of the types, not
3148      the precision; they have precision set to match their range, but
3149      may use a wider mode to match an ABI.  If we change modes, we may
3150      wind up with bad conversions.  For INTEGER_TYPEs in C, must check
3151      the precision as well, so as to yield correct results for
3152      bit-field types.  C++ does not have these separate bit-field
3153      types, and producing a signed or unsigned variant of an
3154      ENUMERAL_TYPE may cause other problems as well.  */
3155
3156   if (!INTEGRAL_TYPE_P (type)
3157       || TYPE_UNSIGNED (type) == unsignedp)
3158     return type;
3159
3160 #define TYPE_OK(node)                                                       \
3161   (TYPE_MODE (type) == TYPE_MODE (node)                                     \
3162    && TYPE_PRECISION (type) == TYPE_PRECISION (node))
3163   if (TYPE_OK (signed_char_type_node))
3164     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3165   if (TYPE_OK (integer_type_node))
3166     return unsignedp ? unsigned_type_node : integer_type_node;
3167   if (TYPE_OK (short_integer_type_node))
3168     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3169   if (TYPE_OK (long_integer_type_node))
3170     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3171   if (TYPE_OK (long_long_integer_type_node))
3172     return (unsignedp ? long_long_unsigned_type_node
3173             : long_long_integer_type_node);
3174   if (TYPE_OK (widest_integer_literal_type_node))
3175     return (unsignedp ? widest_unsigned_literal_type_node
3176             : widest_integer_literal_type_node);
3177
3178 #if HOST_BITS_PER_WIDE_INT >= 64
3179   if (TYPE_OK (intTI_type_node))
3180     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
3181 #endif
3182   if (TYPE_OK (intDI_type_node))
3183     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
3184   if (TYPE_OK (intSI_type_node))
3185     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
3186   if (TYPE_OK (intHI_type_node))
3187     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
3188   if (TYPE_OK (intQI_type_node))
3189     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
3190 #undef TYPE_OK
3191
3192   return build_nonstandard_integer_type (TYPE_PRECISION (type), unsignedp);
3193 }
3194
3195 /* Build a bit-field integer type for the given WIDTH and UNSIGNEDP.  */
3196
3197 tree
3198 c_build_bitfield_integer_type (unsigned HOST_WIDE_INT width, int unsignedp)
3199 {
3200   /* Extended integer types of the same width as a standard type have
3201      lesser rank, so those of the same width as int promote to int or
3202      unsigned int and are valid for printf formats expecting int or
3203      unsigned int.  To avoid such special cases, avoid creating
3204      extended integer types for bit-fields if a standard integer type
3205      is available.  */
3206   if (width == TYPE_PRECISION (integer_type_node))
3207     return unsignedp ? unsigned_type_node : integer_type_node;
3208   if (width == TYPE_PRECISION (signed_char_type_node))
3209     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3210   if (width == TYPE_PRECISION (short_integer_type_node))
3211     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3212   if (width == TYPE_PRECISION (long_integer_type_node))
3213     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3214   if (width == TYPE_PRECISION (long_long_integer_type_node))
3215     return (unsignedp ? long_long_unsigned_type_node
3216             : long_long_integer_type_node);
3217   return build_nonstandard_integer_type (width, unsignedp);
3218 }
3219
3220 /* The C version of the register_builtin_type langhook.  */
3221
3222 void
3223 c_register_builtin_type (tree type, const char* name)
3224 {
3225   tree decl;
3226
3227   decl = build_decl (TYPE_DECL, get_identifier (name), type);
3228   DECL_ARTIFICIAL (decl) = 1;
3229   if (!TYPE_NAME (type))
3230     TYPE_NAME (type) = decl;
3231   pushdecl (decl);
3232
3233   registered_builtin_types = tree_cons (0, type, registered_builtin_types);
3234 }
3235 \f
3236 /* Print an error message for invalid operands to arith operation
3237    CODE with TYPE0 for operand 0, and TYPE1 for operand 1.
3238    LOCATION is the location of the message.  */
3239
3240 void
3241 binary_op_error (location_t location, enum tree_code code,
3242                  tree type0, tree type1)
3243 {
3244   const char *opname;
3245
3246   switch (code)
3247     {
3248     case PLUS_EXPR:
3249       opname = "+"; break;
3250     case MINUS_EXPR:
3251       opname = "-"; break;
3252     case MULT_EXPR:
3253       opname = "*"; break;
3254     case MAX_EXPR:
3255       opname = "max"; break;
3256     case MIN_EXPR:
3257       opname = "min"; break;
3258     case EQ_EXPR:
3259       opname = "=="; break;
3260     case NE_EXPR:
3261       opname = "!="; break;
3262     case LE_EXPR:
3263       opname = "<="; break;
3264     case GE_EXPR:
3265       opname = ">="; break;
3266     case LT_EXPR:
3267       opname = "<"; break;
3268     case GT_EXPR:
3269       opname = ">"; break;
3270     case LSHIFT_EXPR:
3271       opname = "<<"; break;
3272     case RSHIFT_EXPR:
3273       opname = ">>"; break;
3274     case TRUNC_MOD_EXPR:
3275     case FLOOR_MOD_EXPR:
3276       opname = "%"; break;
3277     case TRUNC_DIV_EXPR:
3278     case FLOOR_DIV_EXPR:
3279       opname = "/"; break;
3280     case BIT_AND_EXPR:
3281       opname = "&"; break;
3282     case BIT_IOR_EXPR:
3283       opname = "|"; break;
3284     case TRUTH_ANDIF_EXPR:
3285       opname = "&&"; break;
3286     case TRUTH_ORIF_EXPR:
3287       opname = "||"; break;
3288     case BIT_XOR_EXPR:
3289       opname = "^"; break;
3290     default:
3291       gcc_unreachable ();
3292     }
3293   error_at (location,
3294             "invalid operands to binary %s (have %qT and %qT)", opname,
3295             type0, type1);
3296 }
3297 \f
3298 /* Subroutine of build_binary_op, used for comparison operations.
3299    See if the operands have both been converted from subword integer types
3300    and, if so, perhaps change them both back to their original type.
3301    This function is also responsible for converting the two operands
3302    to the proper common type for comparison.
3303
3304    The arguments of this function are all pointers to local variables
3305    of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
3306    RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.
3307
3308    If this function returns nonzero, it means that the comparison has
3309    a constant value.  What this function returns is an expression for
3310    that value.  */
3311
3312 tree
3313 shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr,
3314                  enum tree_code *rescode_ptr)
3315 {
3316   tree type;
3317   tree op0 = *op0_ptr;
3318   tree op1 = *op1_ptr;
3319   int unsignedp0, unsignedp1;
3320   int real1, real2;
3321   tree primop0, primop1;
3322   enum tree_code code = *rescode_ptr;
3323
3324   /* Throw away any conversions to wider types
3325      already present in the operands.  */
3326
3327   primop0 = get_narrower (op0, &unsignedp0);
3328   primop1 = get_narrower (op1, &unsignedp1);
3329
3330   /* Handle the case that OP0 does not *contain* a conversion
3331      but it *requires* conversion to FINAL_TYPE.  */
3332
3333   if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
3334     unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3335   if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
3336     unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3337
3338   /* If one of the operands must be floated, we cannot optimize.  */
3339   real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
3340   real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
3341
3342   /* If first arg is constant, swap the args (changing operation
3343      so value is preserved), for canonicalization.  Don't do this if
3344      the second arg is 0.  */
3345
3346   if (TREE_CONSTANT (primop0)
3347       && !integer_zerop (primop1) && !real_zerop (primop1)
3348       && !fixed_zerop (primop1))
3349     {
3350       tree tem = primop0;
3351       int temi = unsignedp0;
3352       primop0 = primop1;
3353       primop1 = tem;
3354       tem = op0;
3355       op0 = op1;
3356       op1 = tem;
3357       *op0_ptr = op0;
3358       *op1_ptr = op1;
3359       unsignedp0 = unsignedp1;
3360       unsignedp1 = temi;
3361       temi = real1;
3362       real1 = real2;
3363       real2 = temi;
3364
3365       switch (code)
3366         {
3367         case LT_EXPR:
3368           code = GT_EXPR;
3369           break;
3370         case GT_EXPR:
3371           code = LT_EXPR;
3372           break;
3373         case LE_EXPR:
3374           code = GE_EXPR;
3375           break;
3376         case GE_EXPR:
3377           code = LE_EXPR;
3378           break;
3379         default:
3380           break;
3381         }
3382       *rescode_ptr = code;
3383     }
3384
3385   /* If comparing an integer against a constant more bits wide,
3386      maybe we can deduce a value of 1 or 0 independent of the data.
3387      Or else truncate the constant now
3388      rather than extend the variable at run time.
3389
3390      This is only interesting if the constant is the wider arg.
3391      Also, it is not safe if the constant is unsigned and the
3392      variable arg is signed, since in this case the variable
3393      would be sign-extended and then regarded as unsigned.
3394      Our technique fails in this case because the lowest/highest
3395      possible unsigned results don't follow naturally from the
3396      lowest/highest possible values of the variable operand.
3397      For just EQ_EXPR and NE_EXPR there is another technique that
3398      could be used: see if the constant can be faithfully represented
3399      in the other operand's type, by truncating it and reextending it
3400      and see if that preserves the constant's value.  */
3401
3402   if (!real1 && !real2
3403       && TREE_CODE (TREE_TYPE (primop0)) != FIXED_POINT_TYPE
3404       && TREE_CODE (primop1) == INTEGER_CST
3405       && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
3406     {
3407       int min_gt, max_gt, min_lt, max_lt;
3408       tree maxval, minval;
3409       /* 1 if comparison is nominally unsigned.  */
3410       int unsignedp = TYPE_UNSIGNED (*restype_ptr);
3411       tree val;
3412
3413       type = c_common_signed_or_unsigned_type (unsignedp0,
3414                                                TREE_TYPE (primop0));
3415
3416       maxval = TYPE_MAX_VALUE (type);
3417       minval = TYPE_MIN_VALUE (type);
3418
3419       if (unsignedp && !unsignedp0)
3420         *restype_ptr = c_common_signed_type (*restype_ptr);
3421
3422       if (TREE_TYPE (primop1) != *restype_ptr)
3423         {
3424           /* Convert primop1 to target type, but do not introduce
3425              additional overflow.  We know primop1 is an int_cst.  */
3426           primop1 = force_fit_type_double (*restype_ptr,
3427                                            TREE_INT_CST_LOW (primop1),
3428                                            TREE_INT_CST_HIGH (primop1), 0,
3429                                            TREE_OVERFLOW (primop1));
3430         }
3431       if (type != *restype_ptr)
3432         {
3433           minval = convert (*restype_ptr, minval);
3434           maxval = convert (*restype_ptr, maxval);
3435         }
3436
3437       if (unsignedp && unsignedp0)
3438         {
3439           min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
3440           max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
3441           min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
3442           max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
3443         }
3444       else
3445         {
3446           min_gt = INT_CST_LT (primop1, minval);
3447           max_gt = INT_CST_LT (primop1, maxval);
3448           min_lt = INT_CST_LT (minval, primop1);
3449           max_lt = INT_CST_LT (maxval, primop1);
3450         }
3451
3452       val = 0;
3453       /* This used to be a switch, but Genix compiler can't handle that.  */
3454       if (code == NE_EXPR)
3455         {
3456           if (max_lt || min_gt)
3457             val = truthvalue_true_node;
3458         }
3459       else if (code == EQ_EXPR)
3460         {
3461           if (max_lt || min_gt)
3462             val = truthvalue_false_node;
3463         }
3464       else if (code == LT_EXPR)
3465         {
3466           if (max_lt)
3467             val = truthvalue_true_node;
3468           if (!min_lt)
3469             val = truthvalue_false_node;
3470         }
3471       else if (code == GT_EXPR)
3472         {
3473           if (min_gt)
3474             val = truthvalue_true_node;
3475           if (!max_gt)
3476             val = truthvalue_false_node;
3477         }
3478       else if (code == LE_EXPR)
3479         {
3480           if (!max_gt)
3481             val = truthvalue_true_node;
3482           if (min_gt)
3483             val = truthvalue_false_node;
3484         }
3485       else if (code == GE_EXPR)
3486         {
3487           if (!min_lt)
3488             val = truthvalue_true_node;
3489           if (max_lt)
3490             val = truthvalue_false_node;
3491         }
3492
3493       /* If primop0 was sign-extended and unsigned comparison specd,
3494          we did a signed comparison above using the signed type bounds.
3495          But the comparison we output must be unsigned.
3496
3497          Also, for inequalities, VAL is no good; but if the signed
3498          comparison had *any* fixed result, it follows that the
3499          unsigned comparison just tests the sign in reverse
3500          (positive values are LE, negative ones GE).
3501          So we can generate an unsigned comparison
3502          against an extreme value of the signed type.  */
3503
3504       if (unsignedp && !unsignedp0)
3505         {
3506           if (val != 0)
3507             switch (code)
3508               {
3509               case LT_EXPR:
3510               case GE_EXPR:
3511                 primop1 = TYPE_MIN_VALUE (type);
3512                 val = 0;
3513                 break;
3514
3515               case LE_EXPR:
3516               case GT_EXPR:
3517                 primop1 = TYPE_MAX_VALUE (type);
3518                 val = 0;
3519                 break;
3520
3521               default:
3522                 break;
3523               }
3524           type = c_common_unsigned_type (type);
3525         }
3526
3527       if (TREE_CODE (primop0) != INTEGER_CST)
3528         {
3529           if (val == truthvalue_false_node)
3530             warning (OPT_Wtype_limits, "comparison is always false due to limited range of data type");
3531           if (val == truthvalue_true_node)
3532             warning (OPT_Wtype_limits, "comparison is always true due to limited range of data type");
3533         }
3534
3535       if (val != 0)
3536         {
3537           /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
3538           if (TREE_SIDE_EFFECTS (primop0))
3539             return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
3540           return val;
3541         }
3542
3543       /* Value is not predetermined, but do the comparison
3544          in the type of the operand that is not constant.
3545          TYPE is already properly set.  */
3546     }
3547
3548   /* If either arg is decimal float and the other is float, find the
3549      proper common type to use for comparison.  */
3550   else if (real1 && real2
3551            && (DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop0)))
3552                || DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop1)))))
3553     type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
3554
3555   else if (real1 && real2
3556            && (TYPE_PRECISION (TREE_TYPE (primop0))
3557                == TYPE_PRECISION (TREE_TYPE (primop1))))
3558     type = TREE_TYPE (primop0);
3559
3560   /* If args' natural types are both narrower than nominal type
3561      and both extend in the same manner, compare them
3562      in the type of the wider arg.
3563      Otherwise must actually extend both to the nominal
3564      common type lest different ways of extending
3565      alter the result.
3566      (eg, (short)-1 == (unsigned short)-1  should be 0.)  */
3567
3568   else if (unsignedp0 == unsignedp1 && real1 == real2
3569            && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
3570            && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
3571     {
3572       type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
3573       type = c_common_signed_or_unsigned_type (unsignedp0
3574                                                || TYPE_UNSIGNED (*restype_ptr),
3575                                                type);
3576       /* Make sure shorter operand is extended the right way
3577          to match the longer operand.  */
3578       primop0
3579         = convert (c_common_signed_or_unsigned_type (unsignedp0,
3580                                                      TREE_TYPE (primop0)),
3581                    primop0);
3582       primop1
3583         = convert (c_common_signed_or_unsigned_type (unsignedp1,
3584                                                      TREE_TYPE (primop1)),
3585                    primop1);
3586     }
3587   else
3588     {
3589       /* Here we must do the comparison on the nominal type
3590          using the args exactly as we received them.  */
3591       type = *restype_ptr;
3592       primop0 = op0;
3593       primop1 = op1;
3594
3595       if (!real1 && !real2 && integer_zerop (primop1)
3596           && TYPE_UNSIGNED (*restype_ptr))
3597         {
3598           tree value = 0;
3599           switch (code)
3600             {
3601             case GE_EXPR:
3602               /* All unsigned values are >= 0, so we warn.  However,
3603                  if OP0 is a constant that is >= 0, the signedness of
3604                  the comparison isn't an issue, so suppress the
3605                  warning.  */
3606               if (warn_type_limits && !in_system_header
3607                   && !(TREE_CODE (primop0) == INTEGER_CST
3608                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
3609                                                    primop0))))
3610                 warning (OPT_Wtype_limits,
3611                          "comparison of unsigned expression >= 0 is always true");
3612               value = truthvalue_true_node;
3613               break;
3614
3615             case LT_EXPR:
3616               if (warn_type_limits && !in_system_header
3617                   && !(TREE_CODE (primop0) == INTEGER_CST
3618                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
3619                                                    primop0))))
3620                 warning (OPT_Wtype_limits,
3621                          "comparison of unsigned expression < 0 is always false");
3622               value = truthvalue_false_node;
3623               break;
3624
3625             default:
3626               break;
3627             }
3628
3629           if (value != 0)
3630             {
3631               /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
3632               if (TREE_SIDE_EFFECTS (primop0))
3633                 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
3634                                primop0, value);
3635               return value;
3636             }
3637         }
3638     }
3639
3640   *op0_ptr = convert (type, primop0);
3641   *op1_ptr = convert (type, primop1);
3642
3643   *restype_ptr = truthvalue_type_node;
3644
3645   return 0;
3646 }
3647 \f
3648 /* Return a tree for the sum or difference (RESULTCODE says which)
3649    of pointer PTROP and integer INTOP.  */
3650
3651 tree
3652 pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3653 {
3654   tree size_exp, ret;
3655
3656   /* The result is a pointer of the same type that is being added.  */
3657   tree result_type = TREE_TYPE (ptrop);
3658
3659   if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
3660     {
3661       pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3662                "pointer of type %<void *%> used in arithmetic");
3663       size_exp = integer_one_node;
3664     }
3665   else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE)
3666     {
3667       pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3668                "pointer to a function used in arithmetic");
3669       size_exp = integer_one_node;
3670     }
3671   else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE)
3672     {
3673       pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3674                "pointer to member function used in arithmetic");
3675       size_exp = integer_one_node;
3676     }
3677   else
3678     size_exp = size_in_bytes (TREE_TYPE (result_type));
3679
3680   /* We are manipulating pointer values, so we don't need to warn
3681      about relying on undefined signed overflow.  We disable the
3682      warning here because we use integer types so fold won't know that
3683      they are really pointers.  */
3684   fold_defer_overflow_warnings ();
3685
3686   /* If what we are about to multiply by the size of the elements
3687      contains a constant term, apply distributive law
3688      and multiply that constant term separately.
3689      This helps produce common subexpressions.  */
3690   if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
3691       && !TREE_CONSTANT (intop)
3692       && TREE_CONSTANT (TREE_OPERAND (intop, 1))
3693       && TREE_CONSTANT (size_exp)
3694       /* If the constant comes from pointer subtraction,
3695          skip this optimization--it would cause an error.  */
3696       && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
3697       /* If the constant is unsigned, and smaller than the pointer size,
3698          then we must skip this optimization.  This is because it could cause
3699          an overflow error if the constant is negative but INTOP is not.  */
3700       && (!TYPE_UNSIGNED (TREE_TYPE (intop))
3701           || (TYPE_PRECISION (TREE_TYPE (intop))
3702               == TYPE_PRECISION (TREE_TYPE (ptrop)))))
3703     {
3704       enum tree_code subcode = resultcode;
3705       tree int_type = TREE_TYPE (intop);
3706       if (TREE_CODE (intop) == MINUS_EXPR)
3707         subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
3708       /* Convert both subexpression types to the type of intop,
3709          because weird cases involving pointer arithmetic
3710          can result in a sum or difference with different type args.  */
3711       ptrop = build_binary_op (EXPR_LOCATION (TREE_OPERAND (intop, 1)),
3712                                subcode, ptrop,
3713                                convert (int_type, TREE_OPERAND (intop, 1)), 1);
3714       intop = convert (int_type, TREE_OPERAND (intop, 0));
3715     }
3716
3717   /* Convert the integer argument to a type the same size as sizetype
3718      so the multiply won't overflow spuriously.  */
3719   if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype)
3720       || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype))
3721     intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype),
3722                                              TYPE_UNSIGNED (sizetype)), intop);
3723
3724   /* Replace the integer argument with a suitable product by the object size.
3725      Do this multiplication as signed, then convert to the appropriate
3726      type for the pointer operation.  */
3727   intop = convert (sizetype,
3728                    build_binary_op (EXPR_LOCATION (intop),
3729                                     MULT_EXPR, intop,
3730                                     convert (TREE_TYPE (intop), size_exp), 1));
3731
3732   /* Create the sum or difference.  */
3733   if (resultcode == MINUS_EXPR)
3734     intop = fold_build1 (NEGATE_EXPR, sizetype, intop);
3735
3736   ret = fold_build2 (POINTER_PLUS_EXPR, result_type, ptrop, intop);
3737
3738   fold_undefer_and_ignore_overflow_warnings ();
3739
3740   return ret;
3741 }
3742 \f
3743 /* Wrap a SAVE_EXPR around EXPR, if appropriate.  Like save_expr, but
3744    for C folds the inside expression and wraps a C_MAYBE_CONST_EXPR
3745    around the SAVE_EXPR if needed so that c_fully_fold does not need
3746    to look inside SAVE_EXPRs.  */
3747
3748 tree
3749 c_save_expr (tree expr)
3750 {
3751   bool maybe_const = true;
3752   if (c_dialect_cxx ())
3753     return save_expr (expr);
3754   expr = c_fully_fold (expr, false, &maybe_const);
3755   expr = save_expr (expr);
3756   if (!maybe_const)
3757     {
3758       expr = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (expr), NULL, expr);
3759       C_MAYBE_CONST_EXPR_NON_CONST (expr) = 1;
3760     }
3761   return expr;
3762 }
3763
3764 /* Return whether EXPR is a declaration whose address can never be
3765    NULL.  */
3766
3767 bool
3768 decl_with_nonnull_addr_p (const_tree expr)
3769 {
3770   return (DECL_P (expr)
3771           && (TREE_CODE (expr) == PARM_DECL
3772               || TREE_CODE (expr) == LABEL_DECL
3773               || !DECL_WEAK (expr)));
3774 }
3775
3776 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
3777    or for an `if' or `while' statement or ?..: exp.  It should already
3778    have been validated to be of suitable type; otherwise, a bad
3779    diagnostic may result.
3780
3781    The EXPR is located at LOCATION.
3782
3783    This preparation consists of taking the ordinary
3784    representation of an expression expr and producing a valid tree
3785    boolean expression describing whether expr is nonzero.  We could
3786    simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1),
3787    but we optimize comparisons, &&, ||, and !.
3788
3789    The resulting type should always be `truthvalue_type_node'.  */
3790
3791 tree
3792 c_common_truthvalue_conversion (location_t location, tree expr)
3793 {
3794   switch (TREE_CODE (expr))
3795     {
3796     case EQ_EXPR:   case NE_EXPR:   case UNEQ_EXPR: case LTGT_EXPR:
3797     case LE_EXPR:   case GE_EXPR:   case LT_EXPR:   case GT_EXPR:
3798     case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR:
3799     case ORDERED_EXPR: case UNORDERED_EXPR:
3800       if (TREE_TYPE (expr) == truthvalue_type_node)
3801         return expr;
3802       return build2 (TREE_CODE (expr), truthvalue_type_node,
3803                      TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1));
3804
3805     case TRUTH_ANDIF_EXPR:
3806     case TRUTH_ORIF_EXPR:
3807     case TRUTH_AND_EXPR:
3808     case TRUTH_OR_EXPR:
3809     case TRUTH_XOR_EXPR:
3810       if (TREE_TYPE (expr) == truthvalue_type_node)
3811         return expr;
3812       return build2 (TREE_CODE (expr), truthvalue_type_node,
3813                  c_common_truthvalue_conversion (location,
3814                                                  TREE_OPERAND (expr, 0)),
3815                  c_common_truthvalue_conversion (location,
3816                                                  TREE_OPERAND (expr, 1)));
3817
3818     case TRUTH_NOT_EXPR:
3819       if (TREE_TYPE (expr) == truthvalue_type_node)
3820         return expr;
3821       return build1 (TREE_CODE (expr), truthvalue_type_node,
3822                  c_common_truthvalue_conversion (location,
3823                                                  TREE_OPERAND (expr, 0)));
3824
3825     case ERROR_MARK:
3826       return expr;
3827
3828     case INTEGER_CST:
3829       return integer_zerop (expr) ? truthvalue_false_node
3830                                   : truthvalue_true_node;
3831
3832     case REAL_CST:
3833       return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0)
3834              ? truthvalue_true_node
3835              : truthvalue_false_node;
3836
3837     case FIXED_CST:
3838       return fixed_compare (NE_EXPR, &TREE_FIXED_CST (expr),
3839                             &FCONST0 (TYPE_MODE (TREE_TYPE (expr))))
3840              ? truthvalue_true_node
3841              : truthvalue_false_node;
3842
3843     case FUNCTION_DECL:
3844       expr = build_unary_op (location, ADDR_EXPR, expr, 0);
3845       /* Fall through.  */
3846
3847     case ADDR_EXPR:
3848       {
3849         tree inner = TREE_OPERAND (expr, 0);
3850         if (decl_with_nonnull_addr_p (inner))
3851           {
3852             /* Common Ada/Pascal programmer's mistake.  */
3853             warning_at (location,
3854                         OPT_Waddress,
3855                         "the address of %qD will always evaluate as %<true%>",
3856                         inner);
3857             return truthvalue_true_node;
3858           }
3859
3860         /* If we still have a decl, it is possible for its address to
3861            be NULL, so we cannot optimize.  */
3862         if (DECL_P (inner))
3863           {
3864             gcc_assert (DECL_WEAK (inner));
3865             break;
3866           }
3867
3868         if (TREE_SIDE_EFFECTS (inner))
3869           return build2 (COMPOUND_EXPR, truthvalue_type_node,
3870                          inner, truthvalue_true_node);
3871         else
3872           return truthvalue_true_node;
3873       }
3874
3875     case COMPLEX_EXPR:
3876       return build_binary_op (EXPR_LOCATION (expr),
3877                               (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
3878                                ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
3879                 c_common_truthvalue_conversion (location,
3880                                                 TREE_OPERAND (expr, 0)),
3881                 c_common_truthvalue_conversion (location,
3882                                                 TREE_OPERAND (expr, 1)),
3883                               0);
3884
3885     case NEGATE_EXPR:
3886     case ABS_EXPR:
3887     case FLOAT_EXPR:
3888     case EXCESS_PRECISION_EXPR:
3889       /* These don't change whether an object is nonzero or zero.  */
3890       return c_common_truthvalue_conversion (location, TREE_OPERAND (expr, 0));
3891
3892     case LROTATE_EXPR:
3893     case RROTATE_EXPR:
3894       /* These don't change whether an object is zero or nonzero, but
3895          we can't ignore them if their second arg has side-effects.  */
3896       if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
3897         return build2 (COMPOUND_EXPR, truthvalue_type_node,
3898                        TREE_OPERAND (expr, 1),
3899                        c_common_truthvalue_conversion
3900                         (location, TREE_OPERAND (expr, 0)));
3901       else
3902         return c_common_truthvalue_conversion (location,
3903                                                TREE_OPERAND (expr, 0));
3904
3905     case COND_EXPR:
3906       /* Distribute the conversion into the arms of a COND_EXPR.  */
3907       if (c_dialect_cxx ())
3908         return fold_build3 (COND_EXPR, truthvalue_type_node,
3909                             TREE_OPERAND (expr, 0),
3910                             c_common_truthvalue_conversion (location,
3911                                                             TREE_OPERAND (expr,
3912                                                                           1)),
3913                             c_common_truthvalue_conversion (location,
3914                                                             TREE_OPERAND (expr,
3915                                                                           2)));
3916       else
3917         /* Folding will happen later for C.  */
3918         return build3 (COND_EXPR, truthvalue_type_node,
3919                        TREE_OPERAND (expr, 0),
3920                        c_common_truthvalue_conversion (location,
3921                                                        TREE_OPERAND (expr, 1)),
3922                        c_common_truthvalue_conversion (location,
3923                                                        TREE_OPERAND (expr, 2)));
3924
3925     CASE_CONVERT:
3926       /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
3927          since that affects how `default_conversion' will behave.  */
3928       if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
3929           || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
3930         break;
3931       /* If this is widening the argument, we can ignore it.  */
3932       if (TYPE_PRECISION (TREE_TYPE (expr))
3933           >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
3934         return c_common_truthvalue_conversion (location,
3935                                                TREE_OPERAND (expr, 0));
3936       break;
3937
3938     case MODIFY_EXPR:
3939       if (!TREE_NO_WARNING (expr)
3940           && warn_parentheses)
3941         {
3942           warning (OPT_Wparentheses,
3943                    "suggest parentheses around assignment used as truth value");
3944           TREE_NO_WARNING (expr) = 1;
3945         }
3946       break;
3947
3948     default:
3949       break;
3950     }
3951
3952   if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
3953     {
3954       tree t = c_save_expr (expr);
3955       return (build_binary_op
3956               (EXPR_LOCATION (expr),
3957                (TREE_SIDE_EFFECTS (expr)
3958                 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
3959         c_common_truthvalue_conversion
3960                (location,
3961                 build_unary_op (location, REALPART_EXPR, t, 0)),
3962         c_common_truthvalue_conversion
3963                (location,
3964                 build_unary_op (location, IMAGPART_EXPR, t, 0)),
3965                0));
3966     }
3967
3968   if (TREE_CODE (TREE_TYPE (expr)) == FIXED_POINT_TYPE)
3969     {
3970       tree fixed_zero_node = build_fixed (TREE_TYPE (expr),
3971                                           FCONST0 (TYPE_MODE
3972                                                    (TREE_TYPE (expr))));
3973       return build_binary_op (location, NE_EXPR, expr, fixed_zero_node, 1);
3974     }
3975
3976   return build_binary_op (location, NE_EXPR, expr, integer_zero_node, 1);
3977 }
3978 \f
3979 static void def_builtin_1  (enum built_in_function fncode,
3980                             const char *name,
3981                             enum built_in_class fnclass,
3982                             tree fntype, tree libtype,
3983                             bool both_p, bool fallback_p, bool nonansi_p,
3984                             tree fnattrs, bool implicit_p);
3985
3986
3987 /* Apply the TYPE_QUALS to the new DECL.  */
3988
3989 void
3990 c_apply_type_quals_to_decl (int type_quals, tree decl)
3991 {
3992   tree type = TREE_TYPE (decl);
3993
3994   if (type == error_mark_node)
3995     return;
3996
3997   if (((type_quals & TYPE_QUAL_CONST)
3998        || (type && TREE_CODE (type) == REFERENCE_TYPE))
3999       /* An object declared 'const' is only readonly after it is
4000          initialized.  We don't have any way of expressing this currently,
4001          so we need to be conservative and unset TREE_READONLY for types
4002          with constructors.  Otherwise aliasing code will ignore stores in
4003          an inline constructor.  */
4004       && !(type && TYPE_NEEDS_CONSTRUCTING (type)))
4005     TREE_READONLY (decl) = 1;
4006   if (type_quals & TYPE_QUAL_VOLATILE)
4007     {
4008       TREE_SIDE_EFFECTS (decl) = 1;
4009       TREE_THIS_VOLATILE (decl) = 1;
4010     }
4011   if (type_quals & TYPE_QUAL_RESTRICT)
4012     {
4013       while (type && TREE_CODE (type) == ARRAY_TYPE)
4014         /* Allow 'restrict' on arrays of pointers.
4015            FIXME currently we just ignore it.  */
4016         type = TREE_TYPE (type);
4017       if (!type
4018           || !POINTER_TYPE_P (type)
4019           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))
4020         error ("invalid use of %<restrict%>");
4021       else if (flag_strict_aliasing && type == TREE_TYPE (decl))
4022         /* Indicate we need to make a unique alias set for this pointer.
4023            We can't do it here because it might be pointing to an
4024            incomplete type.  */
4025         DECL_POINTER_ALIAS_SET (decl) = -2;
4026     }
4027 }
4028
4029 /* Hash function for the problem of multiple type definitions in
4030    different files.  This must hash all types that will compare
4031    equal via comptypes to the same value.  In practice it hashes
4032    on some of the simple stuff and leaves the details to comptypes.  */
4033
4034 static hashval_t
4035 c_type_hash (const void *p)
4036 {
4037   int i = 0;
4038   int shift, size;
4039   const_tree const t = (const_tree) p;
4040   tree t2;
4041   switch (TREE_CODE (t))
4042     {
4043     /* For pointers, hash on pointee type plus some swizzling.  */
4044     case POINTER_TYPE:
4045       return c_type_hash (TREE_TYPE (t)) ^ 0x3003003;
4046     /* Hash on number of elements and total size.  */
4047     case ENUMERAL_TYPE:
4048       shift = 3;
4049       t2 = TYPE_VALUES (t);
4050       break;
4051     case RECORD_TYPE:
4052       shift = 0;
4053       t2 = TYPE_FIELDS (t);
4054       break;
4055     case QUAL_UNION_TYPE:
4056       shift = 1;
4057       t2 = TYPE_FIELDS (t);
4058       break;
4059     case UNION_TYPE:
4060       shift = 2;
4061       t2 = TYPE_FIELDS (t);
4062       break;
4063     default:
4064       gcc_unreachable ();
4065     }
4066   for (; t2; t2 = TREE_CHAIN (t2))
4067     i++;
4068   /* We might have a VLA here.  */
4069   if (TREE_CODE (TYPE_SIZE (t)) != INTEGER_CST)
4070     size = 0;
4071   else
4072     size = TREE_INT_CST_LOW (TYPE_SIZE (t));
4073   return ((size << 24) | (i << shift));
4074 }
4075
4076 static GTY((param_is (union tree_node))) htab_t type_hash_table;
4077
4078 /* Return the typed-based alias set for T, which may be an expression
4079    or a type.  Return -1 if we don't do anything special.  */
4080
4081 alias_set_type
4082 c_common_get_alias_set (tree t)
4083 {
4084   tree u;
4085   PTR *slot;
4086
4087   /* Permit type-punning when accessing a union, provided the access
4088      is directly through the union.  For example, this code does not
4089      permit taking the address of a union member and then storing
4090      through it.  Even the type-punning allowed here is a GCC
4091      extension, albeit a common and useful one; the C standard says
4092      that such accesses have implementation-defined behavior.  */
4093   for (u = t;
4094        TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
4095        u = TREE_OPERAND (u, 0))
4096     if (TREE_CODE (u) == COMPONENT_REF
4097         && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
4098       return 0;
4099
4100   /* That's all the expressions we handle specially.  */
4101   if (!TYPE_P (t))
4102     return -1;
4103
4104   /* The C standard guarantees that any object may be accessed via an
4105      lvalue that has character type.  */
4106   if (t == char_type_node
4107       || t == signed_char_type_node
4108       || t == unsigned_char_type_node)
4109     return 0;
4110
4111   /* The C standard specifically allows aliasing between signed and
4112      unsigned variants of the same type.  We treat the signed
4113      variant as canonical.  */
4114   if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t))
4115     {
4116       tree t1 = c_common_signed_type (t);
4117
4118       /* t1 == t can happen for boolean nodes which are always unsigned.  */
4119       if (t1 != t)
4120         return get_alias_set (t1);
4121     }
4122   else if (POINTER_TYPE_P (t))
4123     {
4124       tree t1;
4125
4126       /* Unfortunately, there is no canonical form of a pointer type.
4127          In particular, if we have `typedef int I', then `int *', and
4128          `I *' are different types.  So, we have to pick a canonical
4129          representative.  We do this below.
4130
4131          Technically, this approach is actually more conservative that
4132          it needs to be.  In particular, `const int *' and `int *'
4133          should be in different alias sets, according to the C and C++
4134          standard, since their types are not the same, and so,
4135          technically, an `int **' and `const int **' cannot point at
4136          the same thing.
4137
4138          But, the standard is wrong.  In particular, this code is
4139          legal C++:
4140
4141             int *ip;
4142             int **ipp = &ip;
4143             const int* const* cipp = ipp;
4144
4145          And, it doesn't make sense for that to be legal unless you
4146          can dereference IPP and CIPP.  So, we ignore cv-qualifiers on
4147          the pointed-to types.  This issue has been reported to the
4148          C++ committee.  */
4149       t1 = build_type_no_quals (t);
4150       if (t1 != t)
4151         return get_alias_set (t1);
4152     }
4153
4154   /* Handle the case of multiple type nodes referring to "the same" type,
4155      which occurs with IMA.  These share an alias set.  FIXME:  Currently only
4156      C90 is handled.  (In C99 type compatibility is not transitive, which
4157      complicates things mightily. The alias set splay trees can theoretically
4158      represent this, but insertion is tricky when you consider all the
4159      different orders things might arrive in.) */
4160
4161   if (c_language != clk_c || flag_isoc99)
4162     return -1;
4163
4164   /* Save time if there's only one input file.  */
4165   if (num_in_fnames == 1)
4166     return -1;
4167
4168   /* Pointers need special handling if they point to any type that
4169      needs special handling (below).  */
4170   if (TREE_CODE (t) == POINTER_TYPE)
4171     {
4172       tree t2;
4173       /* Find bottom type under any nested POINTERs.  */
4174       for (t2 = TREE_TYPE (t);
4175            TREE_CODE (t2) == POINTER_TYPE;
4176            t2 = TREE_TYPE (t2))
4177         ;
4178       if (TREE_CODE (t2) != RECORD_TYPE
4179           && TREE_CODE (t2) != ENUMERAL_TYPE
4180           && TREE_CODE (t2) != QUAL_UNION_TYPE
4181           && TREE_CODE (t2) != UNION_TYPE)
4182         return -1;
4183       if (TYPE_SIZE (t2) == 0)
4184         return -1;
4185     }
4186   /* These are the only cases that need special handling.  */
4187   if (TREE_CODE (t) != RECORD_TYPE
4188       && TREE_CODE (t) != ENUMERAL_TYPE
4189       && TREE_CODE (t) != QUAL_UNION_TYPE
4190       && TREE_CODE (t) != UNION_TYPE
4191       && TREE_CODE (t) != POINTER_TYPE)
4192     return -1;
4193   /* Undefined? */
4194   if (TYPE_SIZE (t) == 0)
4195     return -1;
4196
4197   /* Look up t in hash table.  Only one of the compatible types within each
4198      alias set is recorded in the table.  */
4199   if (!type_hash_table)
4200     type_hash_table = htab_create_ggc (1021, c_type_hash,
4201             (htab_eq) lang_hooks.types_compatible_p,
4202             NULL);
4203   slot = htab_find_slot (type_hash_table, t, INSERT);
4204   if (*slot != NULL)
4205     {
4206       TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot);
4207       return TYPE_ALIAS_SET ((tree)*slot);
4208     }
4209   else
4210     /* Our caller will assign and record (in t) a new alias set; all we need
4211        to do is remember t in the hash table.  */
4212     *slot = t;
4213
4214   return -1;
4215 }
4216 \f
4217 /* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where the
4218    second parameter indicates which OPERATOR is being applied.  The COMPLAIN
4219    flag controls whether we should diagnose possibly ill-formed
4220    constructs or not.  */
4221
4222 tree
4223 c_sizeof_or_alignof_type (tree type, bool is_sizeof, int complain)
4224 {
4225   const char *op_name;
4226   tree value = NULL;
4227   enum tree_code type_code = TREE_CODE (type);
4228
4229   op_name = is_sizeof ? "sizeof" : "__alignof__";
4230
4231   if (type_code == FUNCTION_TYPE)
4232     {
4233       if (is_sizeof)
4234         {
4235           if (complain && (pedantic || warn_pointer_arith))
4236             pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
4237                      "invalid application of %<sizeof%> to a function type");
4238           else if (!complain)
4239             return error_mark_node;
4240           value = size_one_node;
4241         }
4242       else
4243         value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);
4244     }
4245   else if (type_code == VOID_TYPE || type_code == ERROR_MARK)
4246     {
4247       if (type_code == VOID_TYPE
4248           && complain && (pedantic || warn_pointer_arith))
4249         pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
4250                  "invalid application of %qs to a void type", op_name);
4251       else if (!complain)
4252         return error_mark_node;
4253       value = size_one_node;
4254     }
4255   else if (!COMPLETE_TYPE_P (type))
4256     {
4257       if (complain)
4258         error ("invalid application of %qs to incomplete type %qT ",
4259                op_name, type);
4260       value = size_zero_node;
4261     }
4262   else
4263     {
4264       if (is_sizeof)
4265         /* Convert in case a char is more than one unit.  */
4266         value = size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
4267                             size_int (TYPE_PRECISION (char_type_node)
4268                                       / BITS_PER_UNIT));
4269       else
4270         value = size_int (TYPE_ALIGN_UNIT (type));
4271     }
4272
4273   /* VALUE will have an integer type with TYPE_IS_SIZETYPE set.
4274      TYPE_IS_SIZETYPE means that certain things (like overflow) will
4275      never happen.  However, this node should really have type
4276      `size_t', which is just a typedef for an ordinary integer type.  */
4277   value = fold_convert (size_type_node, value);
4278   gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value)));
4279
4280   return value;
4281 }
4282
4283 /* Implement the __alignof keyword: Return the minimum required
4284    alignment of EXPR, measured in bytes.  For VAR_DECLs,
4285    FUNCTION_DECLs and FIELD_DECLs return DECL_ALIGN (which can be set
4286    from an "aligned" __attribute__ specification).  */
4287
4288 tree
4289 c_alignof_expr (tree expr)
4290 {
4291   tree t;
4292
4293   if (VAR_OR_FUNCTION_DECL_P (expr))
4294     t = size_int (DECL_ALIGN_UNIT (expr));
4295
4296   else if (TREE_CODE (expr) == COMPONENT_REF
4297            && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1)))
4298     {
4299       error ("%<__alignof%> applied to a bit-field");
4300       t = size_one_node;
4301     }
4302   else if (TREE_CODE (expr) == COMPONENT_REF
4303            && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL)
4304     t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1)));
4305
4306   else if (TREE_CODE (expr) == INDIRECT_REF)
4307     {
4308       tree t = TREE_OPERAND (expr, 0);
4309       tree best = t;
4310       int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
4311
4312       while (CONVERT_EXPR_P (t)
4313              && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE)
4314         {
4315           int thisalign;
4316
4317           t = TREE_OPERAND (t, 0);
4318           thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
4319           if (thisalign > bestalign)
4320             best = t, bestalign = thisalign;
4321         }
4322       return c_alignof (TREE_TYPE (TREE_TYPE (best)));
4323     }
4324   else
4325     return c_alignof (TREE_TYPE (expr));
4326
4327   return fold_convert (size_type_node, t);
4328 }
4329 \f
4330 /* Handle C and C++ default attributes.  */
4331
4332 enum built_in_attribute
4333 {
4334 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
4335 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
4336 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
4337 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
4338 #include "builtin-attrs.def"
4339 #undef DEF_ATTR_NULL_TREE
4340 #undef DEF_ATTR_INT
4341 #undef DEF_ATTR_IDENT
4342 #undef DEF_ATTR_TREE_LIST
4343   ATTR_LAST
4344 };
4345
4346 static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
4347
4348 static void c_init_attributes (void);
4349
4350 enum c_builtin_type
4351 {
4352 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
4353 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
4354 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
4355 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
4356 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
4357 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
4358 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
4359 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) NAME,
4360 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7) NAME,
4361 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
4362 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
4363 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
4364 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
4365 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
4366 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \
4367   NAME,
4368 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
4369 #include "builtin-types.def"
4370 #undef DEF_PRIMITIVE_TYPE
4371 #undef DEF_FUNCTION_TYPE_0
4372 #undef DEF_FUNCTION_TYPE_1
4373 #undef DEF_FUNCTION_TYPE_2
4374 #undef DEF_FUNCTION_TYPE_3
4375 #undef DEF_FUNCTION_TYPE_4
4376 #undef DEF_FUNCTION_TYPE_5
4377 #undef DEF_FUNCTION_TYPE_6
4378 #undef DEF_FUNCTION_TYPE_7
4379 #undef DEF_FUNCTION_TYPE_VAR_0
4380 #undef DEF_FUNCTION_TYPE_VAR_1
4381 #undef DEF_FUNCTION_TYPE_VAR_2
4382 #undef DEF_FUNCTION_TYPE_VAR_3
4383 #undef DEF_FUNCTION_TYPE_VAR_4
4384 #undef DEF_FUNCTION_TYPE_VAR_5
4385 #undef DEF_POINTER_TYPE
4386   BT_LAST
4387 };
4388
4389 typedef enum c_builtin_type builtin_type;
4390
4391 /* A temporary array for c_common_nodes_and_builtins.  Used in
4392    communication with def_fn_type.  */
4393 static tree builtin_types[(int) BT_LAST + 1];
4394
4395 /* A helper function for c_common_nodes_and_builtins.  Build function type
4396    for DEF with return type RET and N arguments.  If VAR is true, then the
4397    function should be variadic after those N arguments.
4398
4399    Takes special care not to ICE if any of the types involved are
4400    error_mark_node, which indicates that said type is not in fact available
4401    (see builtin_type_for_size).  In which case the function type as a whole
4402    should be error_mark_node.  */
4403
4404 static void
4405 def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...)
4406 {
4407   tree args = NULL, t;
4408   va_list list;
4409   int i;
4410
4411   va_start (list, n);
4412   for (i = 0; i < n; ++i)
4413     {
4414       builtin_type a = (builtin_type) va_arg (list, int);
4415       t = builtin_types[a];
4416       if (t == error_mark_node)
4417         goto egress;
4418       args = tree_cons (NULL_TREE, t, args);
4419     }
4420   va_end (list);
4421
4422   args = nreverse (args);
4423   if (!var)
4424     args = chainon (args, void_list_node);
4425
4426   t = builtin_types[ret];
4427   if (t == error_mark_node)
4428     goto egress;
4429   t = build_function_type (t, args);
4430
4431  egress:
4432   builtin_types[def] = t;
4433 }
4434
4435 /* Build builtin functions common to both C and C++ language
4436    frontends.  */
4437
4438 static void
4439 c_define_builtins (tree va_list_ref_type_node, tree va_list_arg_type_node)
4440 {
4441 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
4442   builtin_types[ENUM] = VALUE;
4443 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
4444   def_fn_type (ENUM, RETURN, 0, 0);
4445 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
4446   def_fn_type (ENUM, RETURN, 0, 1, ARG1);
4447 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
4448   def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
4449 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
4450   def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
4451 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
4452   def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
4453 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
4454   def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
4455 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
4456                             ARG6)                                       \
4457   def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
4458 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
4459                             ARG6, ARG7)                                 \
4460   def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
4461 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
4462   def_fn_type (ENUM, RETURN, 1, 0);
4463 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
4464   def_fn_type (ENUM, RETURN, 1, 1, ARG1);
4465 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
4466   def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
4467 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
4468   def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
4469 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
4470   def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
4471 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
4472   def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
4473 #define DEF_POINTER_TYPE(ENUM, TYPE) \
4474   builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
4475
4476 #include "builtin-types.def"
4477
4478 #undef DEF_PRIMITIVE_TYPE
4479 #undef DEF_FUNCTION_TYPE_1
4480 #undef DEF_FUNCTION_TYPE_2
4481 #undef DEF_FUNCTION_TYPE_3
4482 #undef DEF_FUNCTION_TYPE_4
4483 #undef DEF_FUNCTION_TYPE_5
4484 #undef DEF_FUNCTION_TYPE_6
4485 #undef DEF_FUNCTION_TYPE_VAR_0
4486 #undef DEF_FUNCTION_TYPE_VAR_1
4487 #undef DEF_FUNCTION_TYPE_VAR_2
4488 #undef DEF_FUNCTION_TYPE_VAR_3
4489 #undef DEF_FUNCTION_TYPE_VAR_4
4490 #undef DEF_FUNCTION_TYPE_VAR_5
4491 #undef DEF_POINTER_TYPE
4492   builtin_types[(int) BT_LAST] = NULL_TREE;
4493
4494   c_init_attributes ();
4495
4496 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
4497                     NONANSI_P, ATTRS, IMPLICIT, COND)                   \
4498   if (NAME && COND)                                                     \
4499     def_builtin_1 (ENUM, NAME, CLASS,                                   \
4500                    builtin_types[(int) TYPE],                           \
4501                    builtin_types[(int) LIBTYPE],                        \
4502                    BOTH_P, FALLBACK_P, NONANSI_P,                       \
4503                    built_in_attributes[(int) ATTRS], IMPLICIT);
4504 #include "builtins.def"
4505 #undef DEF_BUILTIN
4506
4507   targetm.init_builtins ();
4508
4509   build_common_builtin_nodes ();
4510
4511   if (flag_mudflap)
4512     mudflap_init ();
4513 }
4514
4515 /* Like get_identifier, but avoid warnings about null arguments when
4516    the argument may be NULL for targets where GCC lacks stdint.h type
4517    information.  */
4518
4519 static inline tree
4520 c_get_ident (const char *id)
4521 {
4522   return get_identifier (id);
4523 }
4524
4525 /* Build tree nodes and builtin functions common to both C and C++ language
4526    frontends.  */
4527
4528 void
4529 c_common_nodes_and_builtins (void)
4530 {
4531   int char16_type_size;
4532   int char32_type_size;
4533   int wchar_type_size;
4534   tree array_domain_type;
4535   tree va_list_ref_type_node;
4536   tree va_list_arg_type_node;
4537
4538   /* Define `int' and `char' first so that dbx will output them first.  */
4539   record_builtin_type (RID_INT, NULL, integer_type_node);
4540   record_builtin_type (RID_CHAR, "char", char_type_node);
4541
4542   /* `signed' is the same as `int'.  FIXME: the declarations of "signed",
4543      "unsigned long", "long long unsigned" and "unsigned short" were in C++
4544      but not C.  Are the conditionals here needed?  */
4545   if (c_dialect_cxx ())
4546     record_builtin_type (RID_SIGNED, NULL, integer_type_node);
4547   record_builtin_type (RID_LONG, "long int", long_integer_type_node);
4548   record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
4549   record_builtin_type (RID_MAX, "long unsigned int",
4550                        long_unsigned_type_node);
4551   if (c_dialect_cxx ())
4552     record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
4553   record_builtin_type (RID_MAX, "long long int",
4554                        long_long_integer_type_node);
4555   record_builtin_type (RID_MAX, "long long unsigned int",
4556                        long_long_unsigned_type_node);
4557   if (c_dialect_cxx ())
4558     record_builtin_type (RID_MAX, "long long unsigned",
4559                          long_long_unsigned_type_node);
4560   record_builtin_type (RID_SHORT, "short int", short_integer_type_node);
4561   record_builtin_type (RID_MAX, "short unsigned int",
4562                        short_unsigned_type_node);
4563   if (c_dialect_cxx ())
4564     record_builtin_type (RID_MAX, "unsigned short",
4565                          short_unsigned_type_node);
4566
4567   /* Define both `signed char' and `unsigned char'.  */
4568   record_builtin_type (RID_MAX, "signed char", signed_char_type_node);
4569   record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node);
4570
4571   /* These are types that c_common_type_for_size and
4572      c_common_type_for_mode use.  */
4573   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
4574                                          intQI_type_node));
4575   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
4576                                          intHI_type_node));
4577   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
4578                                          intSI_type_node));
4579   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
4580                                          intDI_type_node));
4581 #if HOST_BITS_PER_WIDE_INT >= 64
4582   if (targetm.scalar_mode_supported_p (TImode))
4583     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
4584                                            get_identifier ("__int128_t"),
4585                                            intTI_type_node));
4586 #endif
4587   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
4588                                          unsigned_intQI_type_node));
4589   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
4590                                          unsigned_intHI_type_node));
4591   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
4592                                          unsigned_intSI_type_node));
4593   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
4594                                          unsigned_intDI_type_node));
4595 #if HOST_BITS_PER_WIDE_INT >= 64
4596   if (targetm.scalar_mode_supported_p (TImode))
4597     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
4598                                            get_identifier ("__uint128_t"),
4599                                            unsigned_intTI_type_node));
4600 #endif
4601
4602   /* Create the widest literal types.  */
4603   widest_integer_literal_type_node
4604     = make_signed_type (HOST_BITS_PER_WIDE_INT * 2);
4605   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
4606                                          widest_integer_literal_type_node));
4607
4608   widest_unsigned_literal_type_node
4609     = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2);
4610   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
4611                                          widest_unsigned_literal_type_node));
4612
4613   /* `unsigned long' is the standard type for sizeof.
4614      Note that stddef.h uses `unsigned long',
4615      and this must agree, even if long and int are the same size.  */
4616   size_type_node =
4617     TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE)));
4618   signed_size_type_node = c_common_signed_type (size_type_node);
4619   set_sizetype (size_type_node);
4620
4621   pid_type_node =
4622     TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE)));
4623
4624   build_common_tree_nodes_2 (flag_short_double);
4625
4626   record_builtin_type (RID_FLOAT, NULL, float_type_node);
4627   record_builtin_type (RID_DOUBLE, NULL, double_type_node);
4628   record_builtin_type (RID_MAX, "long double", long_double_type_node);
4629
4630   /* Only supported decimal floating point extension if the target
4631      actually supports underlying modes. */
4632   if (targetm.scalar_mode_supported_p (SDmode)
4633       && targetm.scalar_mode_supported_p (DDmode)
4634       && targetm.scalar_mode_supported_p (TDmode))
4635     {
4636       record_builtin_type (RID_DFLOAT32, NULL, dfloat32_type_node);
4637       record_builtin_type (RID_DFLOAT64, NULL, dfloat64_type_node);
4638       record_builtin_type (RID_DFLOAT128, NULL, dfloat128_type_node);
4639     }
4640
4641   if (targetm.fixed_point_supported_p ())
4642     {
4643       record_builtin_type (RID_MAX, "short _Fract", short_fract_type_node);
4644       record_builtin_type (RID_FRACT, NULL, fract_type_node);
4645       record_builtin_type (RID_MAX, "long _Fract", long_fract_type_node);
4646       record_builtin_type (RID_MAX, "long long _Fract",
4647                            long_long_fract_type_node);
4648       record_builtin_type (RID_MAX, "unsigned short _Fract",
4649                            unsigned_short_fract_type_node);
4650       record_builtin_type (RID_MAX, "unsigned _Fract",
4651                            unsigned_fract_type_node);
4652       record_builtin_type (RID_MAX, "unsigned long _Fract",
4653                            unsigned_long_fract_type_node);
4654       record_builtin_type (RID_MAX, "unsigned long long _Fract",
4655                            unsigned_long_long_fract_type_node);
4656       record_builtin_type (RID_MAX, "_Sat short _Fract",
4657                            sat_short_fract_type_node);
4658       record_builtin_type (RID_MAX, "_Sat _Fract", sat_fract_type_node);
4659       record_builtin_type (RID_MAX, "_Sat long _Fract",
4660                            sat_long_fract_type_node);
4661       record_builtin_type (RID_MAX, "_Sat long long _Fract",
4662                            sat_long_long_fract_type_node);
4663       record_builtin_type (RID_MAX, "_Sat unsigned short _Fract",
4664                            sat_unsigned_short_fract_type_node);
4665       record_builtin_type (RID_MAX, "_Sat unsigned _Fract",
4666                            sat_unsigned_fract_type_node);
4667       record_builtin_type (RID_MAX, "_Sat unsigned long _Fract",
4668                            sat_unsigned_long_fract_type_node);
4669       record_builtin_type (RID_MAX, "_Sat unsigned long long _Fract",
4670                            sat_unsigned_long_long_fract_type_node);
4671       record_builtin_type (RID_MAX, "short _Accum", short_accum_type_node);
4672       record_builtin_type (RID_ACCUM, NULL, accum_type_node);
4673       record_builtin_type (RID_MAX, "long _Accum", long_accum_type_node);
4674       record_builtin_type (RID_MAX, "long long _Accum",
4675                            long_long_accum_type_node);
4676       record_builtin_type (RID_MAX, "unsigned short _Accum",
4677                            unsigned_short_accum_type_node);
4678       record_builtin_type (RID_MAX, "unsigned _Accum",
4679                            unsigned_accum_type_node);
4680       record_builtin_type (RID_MAX, "unsigned long _Accum",
4681                            unsigned_long_accum_type_node);
4682       record_builtin_type (RID_MAX, "unsigned long long _Accum",
4683                            unsigned_long_long_accum_type_node);
4684       record_builtin_type (RID_MAX, "_Sat short _Accum",
4685                            sat_short_accum_type_node);
4686       record_builtin_type (RID_MAX, "_Sat _Accum", sat_accum_type_node);
4687       record_builtin_type (RID_MAX, "_Sat long _Accum",
4688                            sat_long_accum_type_node);
4689       record_builtin_type (RID_MAX, "_Sat long long _Accum",
4690                           sat_long_long_accum_type_node);
4691       record_builtin_type (RID_MAX, "_Sat unsigned short _Accum",
4692                            sat_unsigned_short_accum_type_node);
4693       record_builtin_type (RID_MAX, "_Sat unsigned _Accum",
4694                            sat_unsigned_accum_type_node);
4695       record_builtin_type (RID_MAX, "_Sat unsigned long _Accum",
4696                            sat_unsigned_long_accum_type_node);
4697       record_builtin_type (RID_MAX, "_Sat unsigned long long _Accum",
4698                            sat_unsigned_long_long_accum_type_node);
4699
4700     }
4701
4702   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
4703                                          get_identifier ("complex int"),
4704                                          complex_integer_type_node));
4705   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
4706                                          get_identifier ("complex float"),
4707                                          complex_float_type_node));
4708   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
4709                                          get_identifier ("complex double"),
4710                                          complex_double_type_node));
4711   lang_hooks.decls.pushdecl
4712     (build_decl (TYPE_DECL, get_identifier ("complex long double"),
4713                  complex_long_double_type_node));
4714
4715   if (c_dialect_cxx ())
4716     /* For C++, make fileptr_type_node a distinct void * type until
4717        FILE type is defined.  */
4718     fileptr_type_node = build_variant_type_copy (ptr_type_node);
4719
4720   record_builtin_type (RID_VOID, NULL, void_type_node);
4721
4722   /* Set the TYPE_NAME for any variants that were built before
4723      record_builtin_type gave names to the built-in types. */
4724   {
4725     tree void_name = TYPE_NAME (void_type_node);
4726     TYPE_NAME (void_type_node) = NULL_TREE;
4727     TYPE_NAME (build_qualified_type (void_type_node, TYPE_QUAL_CONST))
4728       = void_name;
4729     TYPE_NAME (void_type_node) = void_name;
4730   }
4731
4732   /* This node must not be shared.  */
4733   void_zero_node = make_node (INTEGER_CST);
4734   TREE_TYPE (void_zero_node) = void_type_node;
4735
4736   void_list_node = build_void_list_node ();
4737
4738   /* Make a type to be the domain of a few array types
4739      whose domains don't really matter.
4740      200 is small enough that it always fits in size_t
4741      and large enough that it can hold most function names for the
4742      initializations of __FUNCTION__ and __PRETTY_FUNCTION__.  */
4743   array_domain_type = build_index_type (size_int (200));
4744
4745   /* Make a type for arrays of characters.
4746      With luck nothing will ever really depend on the length of this
4747      array type.  */
4748   char_array_type_node
4749     = build_array_type (char_type_node, array_domain_type);
4750
4751   /* Likewise for arrays of ints.  */
4752   int_array_type_node
4753     = build_array_type (integer_type_node, array_domain_type);
4754
4755   string_type_node = build_pointer_type (char_type_node);
4756   const_string_type_node
4757     = build_pointer_type (build_qualified_type
4758                           (char_type_node, TYPE_QUAL_CONST));
4759
4760   /* This is special for C++ so functions can be overloaded.  */
4761   wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE);
4762   wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node));
4763   wchar_type_size = TYPE_PRECISION (wchar_type_node);
4764   underlying_wchar_type_node = wchar_type_node;
4765   if (c_dialect_cxx ())
4766     {
4767       if (TYPE_UNSIGNED (wchar_type_node))
4768         wchar_type_node = make_unsigned_type (wchar_type_size);
4769       else
4770         wchar_type_node = make_signed_type (wchar_type_size);
4771       record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node);
4772     }
4773
4774   /* This is for wide string constants.  */
4775   wchar_array_type_node
4776     = build_array_type (wchar_type_node, array_domain_type);
4777
4778   /* Define 'char16_t'.  */
4779   char16_type_node = get_identifier (CHAR16_TYPE);
4780   char16_type_node = TREE_TYPE (identifier_global_value (char16_type_node));
4781   char16_type_size = TYPE_PRECISION (char16_type_node);
4782   if (c_dialect_cxx ())
4783     {
4784       char16_type_node = make_unsigned_type (char16_type_size);
4785
4786       if (cxx_dialect == cxx0x)
4787         record_builtin_type (RID_CHAR16, "char16_t", char16_type_node);
4788     }
4789
4790   /* This is for UTF-16 string constants.  */
4791   char16_array_type_node
4792     = build_array_type (char16_type_node, array_domain_type);
4793
4794   /* Define 'char32_t'.  */
4795   char32_type_node = get_identifier (CHAR32_TYPE);
4796   char32_type_node = TREE_TYPE (identifier_global_value (char32_type_node));
4797   char32_type_size = TYPE_PRECISION (char32_type_node);
4798   if (c_dialect_cxx ())
4799     {
4800       char32_type_node = make_unsigned_type (char32_type_size);
4801
4802       if (cxx_dialect == cxx0x)
4803         record_builtin_type (RID_CHAR32, "char32_t", char32_type_node);
4804     }
4805
4806   /* This is for UTF-32 string constants.  */
4807   char32_array_type_node
4808     = build_array_type (char32_type_node, array_domain_type);
4809
4810   wint_type_node =
4811     TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE)));
4812
4813   intmax_type_node =
4814     TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE)));
4815   uintmax_type_node =
4816     TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE)));
4817
4818   if (SIG_ATOMIC_TYPE)
4819     sig_atomic_type_node =
4820       TREE_TYPE (identifier_global_value (c_get_ident (SIG_ATOMIC_TYPE)));
4821   if (INT8_TYPE)
4822     int8_type_node =
4823       TREE_TYPE (identifier_global_value (c_get_ident (INT8_TYPE)));
4824   if (INT16_TYPE)
4825     int16_type_node =
4826       TREE_TYPE (identifier_global_value (c_get_ident (INT16_TYPE)));
4827   if (INT32_TYPE)
4828     int32_type_node =
4829       TREE_TYPE (identifier_global_value (c_get_ident (INT32_TYPE)));
4830   if (INT64_TYPE)
4831     int64_type_node =
4832       TREE_TYPE (identifier_global_value (c_get_ident (INT64_TYPE)));
4833   if (UINT8_TYPE)
4834     uint8_type_node =
4835       TREE_TYPE (identifier_global_value (c_get_ident (UINT8_TYPE)));
4836   if (UINT16_TYPE)
4837     uint16_type_node =
4838       TREE_TYPE (identifier_global_value (c_get_ident (UINT16_TYPE)));
4839   if (UINT32_TYPE)
4840     c_uint32_type_node =
4841       TREE_TYPE (identifier_global_value (c_get_ident (UINT32_TYPE)));
4842   if (UINT64_TYPE)
4843     c_uint64_type_node =
4844       TREE_TYPE (identifier_global_value (c_get_ident (UINT64_TYPE)));
4845   if (INT_LEAST8_TYPE)
4846     int_least8_type_node =
4847       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST8_TYPE)));
4848   if (INT_LEAST16_TYPE)
4849     int_least16_type_node =
4850       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST16_TYPE)));
4851   if (INT_LEAST32_TYPE)
4852     int_least32_type_node =
4853       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST32_TYPE)));
4854   if (INT_LEAST64_TYPE)
4855     int_least64_type_node =
4856       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST64_TYPE)));
4857   if (UINT_LEAST8_TYPE)
4858     uint_least8_type_node =
4859       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST8_TYPE)));
4860   if (UINT_LEAST16_TYPE)
4861     uint_least16_type_node =
4862       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST16_TYPE)));
4863   if (UINT_LEAST32_TYPE)
4864     uint_least32_type_node =
4865       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST32_TYPE)));
4866   if (UINT_LEAST64_TYPE)
4867     uint_least64_type_node =
4868       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST64_TYPE)));
4869   if (INT_FAST8_TYPE)
4870     int_fast8_type_node =
4871       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST8_TYPE)));
4872   if (INT_FAST16_TYPE)
4873     int_fast16_type_node =
4874       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST16_TYPE)));
4875   if (INT_FAST32_TYPE)
4876     int_fast32_type_node =
4877       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST32_TYPE)));
4878   if (INT_FAST64_TYPE)
4879     int_fast64_type_node =
4880       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST64_TYPE)));
4881   if (UINT_FAST8_TYPE)
4882     uint_fast8_type_node =
4883       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST8_TYPE)));
4884   if (UINT_FAST16_TYPE)
4885     uint_fast16_type_node =
4886       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST16_TYPE)));
4887   if (UINT_FAST32_TYPE)
4888     uint_fast32_type_node =
4889       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST32_TYPE)));
4890   if (UINT_FAST64_TYPE)
4891     uint_fast64_type_node =
4892       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST64_TYPE)));
4893   if (INTPTR_TYPE)
4894     intptr_type_node =
4895       TREE_TYPE (identifier_global_value (c_get_ident (INTPTR_TYPE)));
4896   if (UINTPTR_TYPE)
4897     uintptr_type_node =
4898       TREE_TYPE (identifier_global_value (c_get_ident (UINTPTR_TYPE)));
4899
4900   default_function_type = build_function_type (integer_type_node, NULL_TREE);
4901   ptrdiff_type_node
4902     = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE)));
4903   unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node);
4904
4905   lang_hooks.decls.pushdecl
4906     (build_decl (TYPE_DECL, get_identifier ("__builtin_va_list"),
4907                  va_list_type_node));
4908 #ifdef TARGET_ENUM_VA_LIST
4909   {
4910     int l;
4911     const char *pname;
4912     tree ptype;
4913     for (l = 0; TARGET_ENUM_VA_LIST (l, &pname, &ptype); ++l)
4914       {
4915         lang_hooks.decls.pushdecl
4916           (build_decl (TYPE_DECL, get_identifier (pname),
4917                        ptype));
4918
4919       }
4920   }
4921 #endif
4922
4923   if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
4924     {
4925       va_list_arg_type_node = va_list_ref_type_node =
4926         build_pointer_type (TREE_TYPE (va_list_type_node));
4927     }
4928   else
4929     {
4930       va_list_arg_type_node = va_list_type_node;
4931       va_list_ref_type_node = build_reference_type (va_list_type_node);
4932     }
4933
4934   if (!flag_preprocess_only)
4935     c_define_builtins (va_list_ref_type_node, va_list_arg_type_node);
4936
4937   main_identifier_node = get_identifier ("main");
4938
4939   /* Create the built-in __null node.  It is important that this is
4940      not shared.  */
4941   null_node = make_node (INTEGER_CST);
4942   TREE_TYPE (null_node) = c_common_type_for_size (POINTER_SIZE, 0);
4943
4944   /* Since builtin_types isn't gc'ed, don't export these nodes.  */
4945   memset (builtin_types, 0, sizeof (builtin_types));
4946 }
4947
4948 /* Look up the function in built_in_decls that corresponds to DECL
4949    and set ASMSPEC as its user assembler name.  DECL must be a
4950    function decl that declares a builtin.  */
4951
4952 void
4953 set_builtin_user_assembler_name (tree decl, const char *asmspec)
4954 {
4955   tree builtin;
4956   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
4957               && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
4958               && asmspec != 0);
4959
4960   builtin = built_in_decls [DECL_FUNCTION_CODE (decl)];
4961   set_user_assembler_name (builtin, asmspec);
4962   switch (DECL_FUNCTION_CODE (decl))
4963     {
4964     case BUILT_IN_MEMCPY:
4965       init_block_move_fn (asmspec);
4966       memcpy_libfunc = set_user_assembler_libfunc ("memcpy", asmspec);
4967       break;
4968     case BUILT_IN_MEMSET:
4969       init_block_clear_fn (asmspec);
4970       memset_libfunc = set_user_assembler_libfunc ("memset", asmspec);
4971       break;
4972     case BUILT_IN_MEMMOVE:
4973       memmove_libfunc = set_user_assembler_libfunc ("memmove", asmspec);
4974       break;
4975     case BUILT_IN_MEMCMP:
4976       memcmp_libfunc = set_user_assembler_libfunc ("memcmp", asmspec);
4977       break;
4978     case BUILT_IN_ABORT:
4979       abort_libfunc = set_user_assembler_libfunc ("abort", asmspec);
4980       break;
4981     default:
4982       break;
4983     }
4984 }
4985
4986 /* The number of named compound-literals generated thus far.  */
4987 static GTY(()) int compound_literal_number;
4988
4989 /* Set DECL_NAME for DECL, a VAR_DECL for a compound-literal.  */
4990
4991 void
4992 set_compound_literal_name (tree decl)
4993 {
4994   char *name;
4995   ASM_FORMAT_PRIVATE_NAME (name, "__compound_literal",
4996                            compound_literal_number);
4997   compound_literal_number++;
4998   DECL_NAME (decl) = get_identifier (name);
4999 }
5000
5001 tree
5002 build_va_arg (tree expr, tree type)
5003 {
5004   return build1 (VA_ARG_EXPR, type, expr);
5005 }
5006
5007
5008 /* Linked list of disabled built-in functions.  */
5009
5010 typedef struct disabled_builtin
5011 {
5012   const char *name;
5013   struct disabled_builtin *next;
5014 } disabled_builtin;
5015 static disabled_builtin *disabled_builtins = NULL;
5016
5017 static bool builtin_function_disabled_p (const char *);
5018
5019 /* Disable a built-in function specified by -fno-builtin-NAME.  If NAME
5020    begins with "__builtin_", give an error.  */
5021
5022 void
5023 disable_builtin_function (const char *name)
5024 {
5025   if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
5026     error ("cannot disable built-in function %qs", name);
5027   else
5028     {
5029       disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin);
5030       new_disabled_builtin->name = name;
5031       new_disabled_builtin->next = disabled_builtins;
5032       disabled_builtins = new_disabled_builtin;
5033     }
5034 }
5035
5036
5037 /* Return true if the built-in function NAME has been disabled, false
5038    otherwise.  */
5039
5040 static bool
5041 builtin_function_disabled_p (const char *name)
5042 {
5043   disabled_builtin *p;
5044   for (p = disabled_builtins; p != NULL; p = p->next)
5045     {
5046       if (strcmp (name, p->name) == 0)
5047         return true;
5048     }
5049   return false;
5050 }
5051
5052
5053 /* Worker for DEF_BUILTIN.
5054    Possibly define a builtin function with one or two names.
5055    Does not declare a non-__builtin_ function if flag_no_builtin, or if
5056    nonansi_p and flag_no_nonansi_builtin.  */
5057
5058 static void
5059 def_builtin_1 (enum built_in_function fncode,
5060                const char *name,
5061                enum built_in_class fnclass,
5062                tree fntype, tree libtype,
5063                bool both_p, bool fallback_p, bool nonansi_p,
5064                tree fnattrs, bool implicit_p)
5065 {
5066   tree decl;
5067   const char *libname;
5068
5069   if (fntype == error_mark_node)
5070     return;
5071
5072   gcc_assert ((!both_p && !fallback_p)
5073               || !strncmp (name, "__builtin_",
5074                            strlen ("__builtin_")));
5075
5076   libname = name + strlen ("__builtin_");
5077   decl = add_builtin_function (name, fntype, fncode, fnclass,
5078                                (fallback_p ? libname : NULL),
5079                                fnattrs);
5080   if (both_p
5081       && !flag_no_builtin && !builtin_function_disabled_p (libname)
5082       && !(nonansi_p && flag_no_nonansi_builtin))
5083     add_builtin_function (libname, libtype, fncode, fnclass,
5084                           NULL, fnattrs);
5085
5086   built_in_decls[(int) fncode] = decl;
5087   if (implicit_p)
5088     implicit_built_in_decls[(int) fncode] = decl;
5089 }
5090 \f
5091 /* Nonzero if the type T promotes to int.  This is (nearly) the
5092    integral promotions defined in ISO C99 6.3.1.1/2.  */
5093
5094 bool
5095 c_promoting_integer_type_p (const_tree t)
5096 {
5097   switch (TREE_CODE (t))
5098     {
5099     case INTEGER_TYPE:
5100       return (TYPE_MAIN_VARIANT (t) == char_type_node
5101               || TYPE_MAIN_VARIANT (t) == signed_char_type_node
5102               || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node
5103               || TYPE_MAIN_VARIANT (t) == short_integer_type_node
5104               || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node
5105               || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node));
5106
5107     case ENUMERAL_TYPE:
5108       /* ??? Technically all enumerations not larger than an int
5109          promote to an int.  But this is used along code paths
5110          that only want to notice a size change.  */
5111       return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node);
5112
5113     case BOOLEAN_TYPE:
5114       return 1;
5115
5116     default:
5117       return 0;
5118     }
5119 }
5120
5121 /* Return 1 if PARMS specifies a fixed number of parameters
5122    and none of their types is affected by default promotions.  */
5123
5124 int
5125 self_promoting_args_p (const_tree parms)
5126 {
5127   const_tree t;
5128   for (t = parms; t; t = TREE_CHAIN (t))
5129     {
5130       tree type = TREE_VALUE (t);
5131
5132       if (type == error_mark_node)
5133         continue;
5134
5135       if (TREE_CHAIN (t) == 0 && type != void_type_node)
5136         return 0;
5137
5138       if (type == 0)
5139         return 0;
5140
5141       if (TYPE_MAIN_VARIANT (type) == float_type_node)
5142         return 0;
5143
5144       if (c_promoting_integer_type_p (type))
5145         return 0;
5146     }
5147   return 1;
5148 }
5149
5150 /* Recursively remove any '*' or '&' operator from TYPE.  */
5151 tree
5152 strip_pointer_operator (tree t)
5153 {
5154   while (POINTER_TYPE_P (t))
5155     t = TREE_TYPE (t);
5156   return t;
5157 }
5158
5159 /* Recursively remove pointer or array type from TYPE. */
5160 tree
5161 strip_pointer_or_array_types (tree t)
5162 {
5163   while (TREE_CODE (t) == ARRAY_TYPE || POINTER_TYPE_P (t))
5164     t = TREE_TYPE (t);
5165   return t;
5166 }
5167
5168 /* Used to compare case labels.  K1 and K2 are actually tree nodes
5169    representing case labels, or NULL_TREE for a `default' label.
5170    Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
5171    K2, and 0 if K1 and K2 are equal.  */
5172
5173 int
5174 case_compare (splay_tree_key k1, splay_tree_key k2)
5175 {
5176   /* Consider a NULL key (such as arises with a `default' label) to be
5177      smaller than anything else.  */
5178   if (!k1)
5179     return k2 ? -1 : 0;
5180   else if (!k2)
5181     return k1 ? 1 : 0;
5182
5183   return tree_int_cst_compare ((tree) k1, (tree) k2);
5184 }
5185
5186 /* Process a case label for the range LOW_VALUE ... HIGH_VALUE.  If
5187    LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is
5188    actually a `default' label.  If only HIGH_VALUE is NULL_TREE, then
5189    case label was declared using the usual C/C++ syntax, rather than
5190    the GNU case range extension.  CASES is a tree containing all the
5191    case ranges processed so far; COND is the condition for the
5192    switch-statement itself.  Returns the CASE_LABEL_EXPR created, or
5193    ERROR_MARK_NODE if no CASE_LABEL_EXPR is created.  */
5194
5195 tree
5196 c_add_case_label (splay_tree cases, tree cond, tree orig_type,
5197                   tree low_value, tree high_value)
5198 {
5199   tree type;
5200   tree label;
5201   tree case_label;
5202   splay_tree_node node;
5203
5204   /* Create the LABEL_DECL itself.  */
5205   label = create_artificial_label ();
5206
5207   /* If there was an error processing the switch condition, bail now
5208      before we get more confused.  */
5209   if (!cond || cond == error_mark_node)
5210     goto error_out;
5211
5212   if ((low_value && TREE_TYPE (low_value)
5213        && POINTER_TYPE_P (TREE_TYPE (low_value)))
5214       || (high_value && TREE_TYPE (high_value)
5215           && POINTER_TYPE_P (TREE_TYPE (high_value))))
5216     {
5217       error ("pointers are not permitted as case values");
5218       goto error_out;
5219     }
5220
5221   /* Case ranges are a GNU extension.  */
5222   if (high_value)
5223     pedwarn (input_location, OPT_pedantic,
5224              "range expressions in switch statements are non-standard");
5225
5226   type = TREE_TYPE (cond);
5227   if (low_value)
5228     {
5229       low_value = check_case_value (low_value);
5230       low_value = convert_and_check (type, low_value);
5231       if (low_value == error_mark_node)
5232         goto error_out;
5233     }
5234   if (high_value)
5235     {
5236       high_value = check_case_value (high_value);
5237       high_value = convert_and_check (type, high_value);
5238       if (high_value == error_mark_node)
5239         goto error_out;
5240     }
5241
5242   if (low_value && high_value)
5243     {
5244       /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
5245          really a case range, even though it was written that way.
5246          Remove the HIGH_VALUE to simplify later processing.  */
5247       if (tree_int_cst_equal (low_value, high_value))
5248         high_value = NULL_TREE;
5249       else if (!tree_int_cst_lt (low_value, high_value))
5250         warning (0, "empty range specified");
5251     }
5252
5253   /* See if the case is in range of the type of the original testing
5254      expression.  If both low_value and high_value are out of range,
5255      don't insert the case label and return NULL_TREE.  */
5256   if (low_value
5257       && !check_case_bounds (type, orig_type,
5258                              &low_value, high_value ? &high_value : NULL))
5259     return NULL_TREE;
5260
5261   /* Look up the LOW_VALUE in the table of case labels we already
5262      have.  */
5263   node = splay_tree_lookup (cases, (splay_tree_key) low_value);
5264   /* If there was not an exact match, check for overlapping ranges.
5265      There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
5266      that's a `default' label and the only overlap is an exact match.  */
5267   if (!node && (low_value || high_value))
5268     {
5269       splay_tree_node low_bound;
5270       splay_tree_node high_bound;
5271
5272       /* Even though there wasn't an exact match, there might be an
5273          overlap between this case range and another case range.
5274          Since we've (inductively) not allowed any overlapping case
5275          ranges, we simply need to find the greatest low case label
5276          that is smaller that LOW_VALUE, and the smallest low case
5277          label that is greater than LOW_VALUE.  If there is an overlap
5278          it will occur in one of these two ranges.  */
5279       low_bound = splay_tree_predecessor (cases,
5280                                           (splay_tree_key) low_value);
5281       high_bound = splay_tree_successor (cases,
5282                                          (splay_tree_key) low_value);
5283
5284       /* Check to see if the LOW_BOUND overlaps.  It is smaller than
5285          the LOW_VALUE, so there is no need to check unless the
5286          LOW_BOUND is in fact itself a case range.  */
5287       if (low_bound
5288           && CASE_HIGH ((tree) low_bound->value)
5289           && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
5290                                     low_value) >= 0)
5291         node = low_bound;
5292       /* Check to see if the HIGH_BOUND overlaps.  The low end of that
5293          range is bigger than the low end of the current range, so we
5294          are only interested if the current range is a real range, and
5295          not an ordinary case label.  */
5296       else if (high_bound
5297                && high_value
5298                && (tree_int_cst_compare ((tree) high_bound->key,
5299                                          high_value)
5300                    <= 0))
5301         node = high_bound;
5302     }
5303   /* If there was an overlap, issue an error.  */
5304   if (node)
5305     {
5306       tree duplicate = CASE_LABEL ((tree) node->value);
5307
5308       if (high_value)
5309         {
5310           error ("duplicate (or overlapping) case value");
5311           error ("%Jthis is the first entry overlapping that value", duplicate);
5312         }
5313       else if (low_value)
5314         {
5315           error ("duplicate case value") ;
5316           error ("%Jpreviously used here", duplicate);
5317         }
5318       else
5319         {
5320           error ("multiple default labels in one switch");
5321           error ("%Jthis is the first default label", duplicate);
5322         }
5323       goto error_out;
5324     }
5325
5326   /* Add a CASE_LABEL to the statement-tree.  */
5327   case_label = add_stmt (build_case_label (low_value, high_value, label));
5328   /* Register this case label in the splay tree.  */
5329   splay_tree_insert (cases,
5330                      (splay_tree_key) low_value,
5331                      (splay_tree_value) case_label);
5332
5333   return case_label;
5334
5335  error_out:
5336   /* Add a label so that the back-end doesn't think that the beginning of
5337      the switch is unreachable.  Note that we do not add a case label, as
5338      that just leads to duplicates and thence to failure later on.  */
5339   if (!cases->root)
5340     {
5341       tree t = create_artificial_label ();
5342       add_stmt (build_stmt (LABEL_EXPR, t));
5343     }
5344   return error_mark_node;
5345 }
5346
5347 /* Subroutines of c_do_switch_warnings, called via splay_tree_foreach.
5348    Used to verify that case values match up with enumerator values.  */
5349
5350 static void
5351 match_case_to_enum_1 (tree key, tree type, tree label)
5352 {
5353   char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1];
5354
5355   /* ??? Not working too hard to print the double-word value.
5356      Should perhaps be done with %lwd in the diagnostic routines?  */
5357   if (TREE_INT_CST_HIGH (key) == 0)
5358     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED,
5359               TREE_INT_CST_LOW (key));
5360   else if (!TYPE_UNSIGNED (type)
5361            && TREE_INT_CST_HIGH (key) == -1
5362            && TREE_INT_CST_LOW (key) != 0)
5363     snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED,
5364               -TREE_INT_CST_LOW (key));
5365   else
5366     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX,
5367               (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (key),
5368               (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (key));
5369
5370   if (TYPE_NAME (type) == 0)
5371     warning (warn_switch ? OPT_Wswitch : OPT_Wswitch_enum,
5372              "%Jcase value %qs not in enumerated type",
5373              CASE_LABEL (label), buf);
5374   else
5375     warning (warn_switch ? OPT_Wswitch : OPT_Wswitch_enum,
5376              "%Jcase value %qs not in enumerated type %qT",
5377              CASE_LABEL (label), buf, type);
5378 }
5379
5380 /* Subroutine of c_do_switch_warnings, called via splay_tree_foreach.
5381    Used to verify that case values match up with enumerator values.  */
5382
5383 static int
5384 match_case_to_enum (splay_tree_node node, void *data)
5385 {
5386   tree label = (tree) node->value;
5387   tree type = (tree) data;
5388
5389   /* Skip default case.  */
5390   if (!CASE_LOW (label))
5391     return 0;
5392
5393   /* If CASE_LOW_SEEN is not set, that means CASE_LOW did not appear
5394      when we did our enum->case scan.  Reset our scratch bit after.  */
5395   if (!CASE_LOW_SEEN (label))
5396     match_case_to_enum_1 (CASE_LOW (label), type, label);
5397   else
5398     CASE_LOW_SEEN (label) = 0;
5399
5400   /* If CASE_HIGH is non-null, we have a range.  If CASE_HIGH_SEEN is
5401      not set, that means that CASE_HIGH did not appear when we did our
5402      enum->case scan.  Reset our scratch bit after.  */
5403   if (CASE_HIGH (label))
5404     {
5405       if (!CASE_HIGH_SEEN (label))
5406         match_case_to_enum_1 (CASE_HIGH (label), type, label);
5407       else
5408         CASE_HIGH_SEEN (label) = 0;
5409     }
5410
5411   return 0;
5412 }
5413
5414 /* Handle -Wswitch*.  Called from the front end after parsing the
5415    switch construct.  */
5416 /* ??? Should probably be somewhere generic, since other languages
5417    besides C and C++ would want this.  At the moment, however, C/C++
5418    are the only tree-ssa languages that support enumerations at all,
5419    so the point is moot.  */
5420
5421 void
5422 c_do_switch_warnings (splay_tree cases, location_t switch_location,
5423                       tree type, tree cond)
5424 {
5425   splay_tree_node default_node;
5426   splay_tree_node node;
5427   tree chain;
5428   int saved_warn_switch;
5429
5430   if (!warn_switch && !warn_switch_enum && !warn_switch_default)
5431     return;
5432
5433   default_node = splay_tree_lookup (cases, (splay_tree_key) NULL);
5434   if (!default_node)
5435     warning (OPT_Wswitch_default, "%Hswitch missing default case",
5436              &switch_location);
5437
5438   /* From here on, we only care about about enumerated types.  */
5439   if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
5440     return;
5441
5442   /* If the switch expression was an enumerated type, check that
5443      exactly all enumeration literals are covered by the cases.
5444      The check is made when -Wswitch was specified and there is no
5445      default case, or when -Wswitch-enum was specified.  */
5446
5447   if (!warn_switch_enum
5448       && !(warn_switch && !default_node))
5449     return;
5450
5451   /* Clearing COND if it is not an integer constant simplifies
5452      the tests inside the loop below.  */
5453   if (TREE_CODE (cond) != INTEGER_CST)
5454     cond = NULL_TREE;
5455
5456   /* The time complexity here is O(N*lg(N)) worst case, but for the
5457       common case of monotonically increasing enumerators, it is
5458       O(N), since the nature of the splay tree will keep the next
5459       element adjacent to the root at all times.  */
5460
5461   for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain))
5462     {
5463       tree value = TREE_VALUE (chain);
5464       if (TREE_CODE (value) == CONST_DECL)
5465         value = DECL_INITIAL (value);
5466       node = splay_tree_lookup (cases, (splay_tree_key) value);
5467       if (node)
5468         {
5469           /* Mark the CASE_LOW part of the case entry as seen.  */
5470           tree label = (tree) node->value;
5471           CASE_LOW_SEEN (label) = 1;
5472           continue;
5473         }
5474
5475       /* Even though there wasn't an exact match, there might be a
5476          case range which includes the enumerator's value.  */
5477       node = splay_tree_predecessor (cases, (splay_tree_key) value);
5478       if (node && CASE_HIGH ((tree) node->value))
5479         {
5480           tree label = (tree) node->value;
5481           int cmp = tree_int_cst_compare (CASE_HIGH (label), value);
5482           if (cmp >= 0)
5483             {
5484               /* If we match the upper bound exactly, mark the CASE_HIGH
5485                  part of the case entry as seen.  */
5486               if (cmp == 0)
5487                 CASE_HIGH_SEEN (label) = 1;
5488               continue;
5489             }
5490         }
5491
5492       /* We've now determined that this enumerated literal isn't
5493          handled by the case labels of the switch statement.  */
5494
5495       /* If the switch expression is a constant, we only really care
5496          about whether that constant is handled by the switch.  */
5497       if (cond && tree_int_cst_compare (cond, value))
5498         continue;
5499
5500       /* If there is a default_node, the only relevant option is
5501          Wswitch-enum. Otherwise, if both are enabled then we prefer
5502          to warn using -Wswitch because -Wswitch is enabled by -Wall
5503          while -Wswitch-enum is explicit.  */
5504       warning ((default_node || !warn_switch)
5505                ? OPT_Wswitch_enum : OPT_Wswitch,
5506                "%Henumeration value %qE not handled in switch",
5507                &switch_location, TREE_PURPOSE (chain));
5508     }
5509
5510   /* Warn if there are case expressions that don't correspond to
5511      enumerators.  This can occur since C and C++ don't enforce
5512      type-checking of assignments to enumeration variables.
5513
5514      The time complexity here is now always O(N) worst case, since
5515      we should have marked both the lower bound and upper bound of
5516      every disjoint case label, with CASE_LOW_SEEN and CASE_HIGH_SEEN
5517      above.  This scan also resets those fields.  */
5518
5519   /* If there is a default_node, the only relevant option is
5520      Wswitch-enum. Otherwise, if both are enabled then we prefer
5521      to warn using -Wswitch because -Wswitch is enabled by -Wall
5522      while -Wswitch-enum is explicit.  */
5523   saved_warn_switch = warn_switch;
5524   if (default_node)
5525     warn_switch = 0;
5526   splay_tree_foreach (cases, match_case_to_enum, type);
5527   warn_switch = saved_warn_switch;
5528
5529 }
5530
5531 /* Finish an expression taking the address of LABEL (an
5532    IDENTIFIER_NODE).  Returns an expression for the address.
5533
5534    LOC is the location for the expression returned.  */
5535
5536 tree
5537 finish_label_address_expr (tree label, location_t loc)
5538 {
5539   tree result;
5540
5541   pedwarn (input_location, OPT_pedantic, "taking the address of a label is non-standard");
5542
5543   if (label == error_mark_node)
5544     return error_mark_node;
5545
5546   label = lookup_label (label);
5547   if (label == NULL_TREE)
5548     result = null_pointer_node;
5549   else
5550     {
5551       TREE_USED (label) = 1;
5552       result = build1 (ADDR_EXPR, ptr_type_node, label);
5553       /* The current function in not necessarily uninlinable.
5554          Computed gotos are incompatible with inlining, but the value
5555          here could be used only in a diagnostic, for example.  */
5556       protected_set_expr_location (result, loc);
5557     }
5558
5559   return result;
5560 }
5561 \f
5562
5563 /* Given a boolean expression ARG, return a tree representing an increment
5564    or decrement (as indicated by CODE) of ARG.  The front end must check for
5565    invalid cases (e.g., decrement in C++).  */
5566 tree
5567 boolean_increment (enum tree_code code, tree arg)
5568 {
5569   tree val;
5570   tree true_res = build_int_cst (TREE_TYPE (arg), 1);
5571
5572   arg = stabilize_reference (arg);
5573   switch (code)
5574     {
5575     case PREINCREMENT_EXPR:
5576       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
5577       break;
5578     case POSTINCREMENT_EXPR:
5579       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
5580       arg = save_expr (arg);
5581       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
5582       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
5583       break;
5584     case PREDECREMENT_EXPR:
5585       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
5586                     invert_truthvalue (arg));
5587       break;
5588     case POSTDECREMENT_EXPR:
5589       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
5590                     invert_truthvalue (arg));
5591       arg = save_expr (arg);
5592       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
5593       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
5594       break;
5595     default:
5596       gcc_unreachable ();
5597     }
5598   TREE_SIDE_EFFECTS (val) = 1;
5599   return val;
5600 }
5601 \f
5602 /* Built-in macros for stddef.h and stdint.h, that require macros
5603    defined in this file.  */
5604 void
5605 c_stddef_cpp_builtins(void)
5606 {
5607   builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0);
5608   builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0);
5609   builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0);
5610   builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0);
5611   builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0);
5612   builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0);
5613   builtin_define_with_value ("__CHAR16_TYPE__", CHAR16_TYPE, 0);
5614   builtin_define_with_value ("__CHAR32_TYPE__", CHAR32_TYPE, 0);
5615   if (SIG_ATOMIC_TYPE)
5616     builtin_define_with_value ("__SIG_ATOMIC_TYPE__", SIG_ATOMIC_TYPE, 0);
5617   if (INT8_TYPE)
5618     builtin_define_with_value ("__INT8_TYPE__", INT8_TYPE, 0);
5619   if (INT16_TYPE)
5620     builtin_define_with_value ("__INT16_TYPE__", INT16_TYPE, 0);
5621   if (INT32_TYPE)
5622     builtin_define_with_value ("__INT32_TYPE__", INT32_TYPE, 0);
5623   if (INT64_TYPE)
5624     builtin_define_with_value ("__INT64_TYPE__", INT64_TYPE, 0);
5625   if (UINT8_TYPE)
5626     builtin_define_with_value ("__UINT8_TYPE__", UINT8_TYPE, 0);
5627   if (UINT16_TYPE)
5628     builtin_define_with_value ("__UINT16_TYPE__", UINT16_TYPE, 0);
5629   if (UINT32_TYPE)
5630     builtin_define_with_value ("__UINT32_TYPE__", UINT32_TYPE, 0);
5631   if (UINT64_TYPE)
5632     builtin_define_with_value ("__UINT64_TYPE__", UINT64_TYPE, 0);
5633   if (INT_LEAST8_TYPE)
5634     builtin_define_with_value ("__INT_LEAST8_TYPE__", INT_LEAST8_TYPE, 0);
5635   if (INT_LEAST16_TYPE)
5636     builtin_define_with_value ("__INT_LEAST16_TYPE__", INT_LEAST16_TYPE, 0);
5637   if (INT_LEAST32_TYPE)
5638     builtin_define_with_value ("__INT_LEAST32_TYPE__", INT_LEAST32_TYPE, 0);
5639   if (INT_LEAST64_TYPE)
5640     builtin_define_with_value ("__INT_LEAST64_TYPE__", INT_LEAST64_TYPE, 0);
5641   if (UINT_LEAST8_TYPE)
5642     builtin_define_with_value ("__UINT_LEAST8_TYPE__", UINT_LEAST8_TYPE, 0);
5643   if (UINT_LEAST16_TYPE)
5644     builtin_define_with_value ("__UINT_LEAST16_TYPE__", UINT_LEAST16_TYPE, 0);
5645   if (UINT_LEAST32_TYPE)
5646     builtin_define_with_value ("__UINT_LEAST32_TYPE__", UINT_LEAST32_TYPE, 0);
5647   if (UINT_LEAST64_TYPE)
5648     builtin_define_with_value ("__UINT_LEAST64_TYPE__", UINT_LEAST64_TYPE, 0);
5649   if (INT_FAST8_TYPE)
5650     builtin_define_with_value ("__INT_FAST8_TYPE__", INT_FAST8_TYPE, 0);
5651   if (INT_FAST16_TYPE)
5652     builtin_define_with_value ("__INT_FAST16_TYPE__", INT_FAST16_TYPE, 0);
5653   if (INT_FAST32_TYPE)
5654     builtin_define_with_value ("__INT_FAST32_TYPE__", INT_FAST32_TYPE, 0);
5655   if (INT_FAST64_TYPE)
5656     builtin_define_with_value ("__INT_FAST64_TYPE__", INT_FAST64_TYPE, 0);
5657   if (UINT_FAST8_TYPE)
5658     builtin_define_with_value ("__UINT_FAST8_TYPE__", UINT_FAST8_TYPE, 0);
5659   if (UINT_FAST16_TYPE)
5660     builtin_define_with_value ("__UINT_FAST16_TYPE__", UINT_FAST16_TYPE, 0);
5661   if (UINT_FAST32_TYPE)
5662     builtin_define_with_value ("__UINT_FAST32_TYPE__", UINT_FAST32_TYPE, 0);
5663   if (UINT_FAST64_TYPE)
5664     builtin_define_with_value ("__UINT_FAST64_TYPE__", UINT_FAST64_TYPE, 0);
5665   if (INTPTR_TYPE)
5666     builtin_define_with_value ("__INTPTR_TYPE__", INTPTR_TYPE, 0);
5667   if (UINTPTR_TYPE)
5668     builtin_define_with_value ("__UINTPTR_TYPE__", UINTPTR_TYPE, 0);
5669 }
5670
5671 static void
5672 c_init_attributes (void)
5673 {
5674   /* Fill in the built_in_attributes array.  */
5675 #define DEF_ATTR_NULL_TREE(ENUM)                                \
5676   built_in_attributes[(int) ENUM] = NULL_TREE;
5677 #define DEF_ATTR_INT(ENUM, VALUE)                               \
5678   built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
5679 #define DEF_ATTR_IDENT(ENUM, STRING)                            \
5680   built_in_attributes[(int) ENUM] = get_identifier (STRING);
5681 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
5682   built_in_attributes[(int) ENUM]                       \
5683     = tree_cons (built_in_attributes[(int) PURPOSE],    \
5684                  built_in_attributes[(int) VALUE],      \
5685                  built_in_attributes[(int) CHAIN]);
5686 #include "builtin-attrs.def"
5687 #undef DEF_ATTR_NULL_TREE
5688 #undef DEF_ATTR_INT
5689 #undef DEF_ATTR_IDENT
5690 #undef DEF_ATTR_TREE_LIST
5691 }
5692
5693 /* Attribute handlers common to C front ends.  */
5694
5695 /* Handle a "packed" attribute; arguments as in
5696    struct attribute_spec.handler.  */
5697
5698 static tree
5699 handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5700                          int flags, bool *no_add_attrs)
5701 {
5702   if (TYPE_P (*node))
5703     {
5704       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5705         *node = build_variant_type_copy (*node);
5706       TYPE_PACKED (*node) = 1;
5707     }
5708   else if (TREE_CODE (*node) == FIELD_DECL)
5709     {
5710       if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT
5711           /* Still pack bitfields.  */
5712           && ! DECL_INITIAL (*node))
5713         warning (OPT_Wattributes,
5714                  "%qE attribute ignored for field of type %qT",
5715                  name, TREE_TYPE (*node));
5716       else
5717         DECL_PACKED (*node) = 1;
5718     }
5719   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
5720      used for DECL_REGISTER.  It wouldn't mean anything anyway.
5721      We can't set DECL_PACKED on the type of a TYPE_DECL, because
5722      that changes what the typedef is typing.  */
5723   else
5724     {
5725       warning (OPT_Wattributes, "%qE attribute ignored", name);
5726       *no_add_attrs = true;
5727     }
5728
5729   return NULL_TREE;
5730 }
5731
5732 /* Handle a "nocommon" attribute; arguments as in
5733    struct attribute_spec.handler.  */
5734
5735 static tree
5736 handle_nocommon_attribute (tree *node, tree name,
5737                            tree ARG_UNUSED (args),
5738                            int ARG_UNUSED (flags), bool *no_add_attrs)
5739 {
5740   if (TREE_CODE (*node) == VAR_DECL)
5741     DECL_COMMON (*node) = 0;
5742   else
5743     {
5744       warning (OPT_Wattributes, "%qE attribute ignored", name);
5745       *no_add_attrs = true;
5746     }
5747
5748   return NULL_TREE;
5749 }
5750
5751 /* Handle a "common" attribute; arguments as in
5752    struct attribute_spec.handler.  */
5753
5754 static tree
5755 handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5756                          int ARG_UNUSED (flags), bool *no_add_attrs)
5757 {
5758   if (TREE_CODE (*node) == VAR_DECL)
5759     DECL_COMMON (*node) = 1;
5760   else
5761     {
5762       warning (OPT_Wattributes, "%qE attribute ignored", name);
5763       *no_add_attrs = true;
5764     }
5765
5766   return NULL_TREE;
5767 }
5768
5769 /* Handle a "noreturn" attribute; arguments as in
5770    struct attribute_spec.handler.  */
5771
5772 static tree
5773 handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5774                            int ARG_UNUSED (flags), bool *no_add_attrs)
5775 {
5776   tree type = TREE_TYPE (*node);
5777
5778   /* See FIXME comment in c_common_attribute_table.  */
5779   if (TREE_CODE (*node) == FUNCTION_DECL)
5780     TREE_THIS_VOLATILE (*node) = 1;
5781   else if (TREE_CODE (type) == POINTER_TYPE
5782            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
5783     TREE_TYPE (*node)
5784       = build_pointer_type
5785         (build_type_variant (TREE_TYPE (type),
5786                              TYPE_READONLY (TREE_TYPE (type)), 1));
5787   else
5788     {
5789       warning (OPT_Wattributes, "%qE attribute ignored", name);
5790       *no_add_attrs = true;
5791     }
5792
5793   return NULL_TREE;
5794 }
5795
5796 /* Handle a "hot" and attribute; arguments as in
5797    struct attribute_spec.handler.  */
5798
5799 static tree
5800 handle_hot_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5801                       int ARG_UNUSED (flags), bool *no_add_attrs)
5802 {
5803   if (TREE_CODE (*node) == FUNCTION_DECL)
5804     {
5805       if (lookup_attribute ("cold", DECL_ATTRIBUTES (*node)) != NULL)
5806         {
5807           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
5808                    name, "cold");
5809           *no_add_attrs = true;
5810         }
5811       /* Most of the rest of the hot processing is done later with
5812          lookup_attribute.  */
5813     }
5814   else
5815     {
5816       warning (OPT_Wattributes, "%qE attribute ignored", name);
5817       *no_add_attrs = true;
5818     }
5819
5820   return NULL_TREE;
5821 }
5822 /* Handle a "cold" and attribute; arguments as in
5823    struct attribute_spec.handler.  */
5824
5825 static tree
5826 handle_cold_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5827                        int ARG_UNUSED (flags), bool *no_add_attrs)
5828 {
5829   if (TREE_CODE (*node) == FUNCTION_DECL)
5830     {
5831       if (lookup_attribute ("hot", DECL_ATTRIBUTES (*node)) != NULL)
5832         {
5833           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
5834                    name, "hot");
5835           *no_add_attrs = true;
5836         }
5837       /* Most of the rest of the cold processing is done later with
5838          lookup_attribute.  */
5839     }
5840   else
5841     {
5842       warning (OPT_Wattributes, "%qE attribute ignored", name);
5843       *no_add_attrs = true;
5844     }
5845
5846   return NULL_TREE;
5847 }
5848
5849 /* Handle a "noinline" attribute; arguments as in
5850    struct attribute_spec.handler.  */
5851
5852 static tree
5853 handle_noinline_attribute (tree *node, tree name,
5854                            tree ARG_UNUSED (args),
5855                            int ARG_UNUSED (flags), bool *no_add_attrs)
5856 {
5857   if (TREE_CODE (*node) == FUNCTION_DECL)
5858     DECL_UNINLINABLE (*node) = 1;
5859   else
5860     {
5861       warning (OPT_Wattributes, "%qE attribute ignored", name);
5862       *no_add_attrs = true;
5863     }
5864
5865   return NULL_TREE;
5866 }
5867
5868 /* Handle a "always_inline" attribute; arguments as in
5869    struct attribute_spec.handler.  */
5870
5871 static tree
5872 handle_always_inline_attribute (tree *node, tree name,
5873                                 tree ARG_UNUSED (args),
5874                                 int ARG_UNUSED (flags),
5875                                 bool *no_add_attrs)
5876 {
5877   if (TREE_CODE (*node) == FUNCTION_DECL)
5878     {
5879       /* Set the attribute and mark it for disregarding inline
5880          limits.  */
5881       DECL_DISREGARD_INLINE_LIMITS (*node) = 1;
5882     }
5883   else
5884     {
5885       warning (OPT_Wattributes, "%qE attribute ignored", name);
5886       *no_add_attrs = true;
5887     }
5888
5889   return NULL_TREE;
5890 }
5891
5892 /* Handle a "gnu_inline" attribute; arguments as in
5893    struct attribute_spec.handler.  */
5894
5895 static tree
5896 handle_gnu_inline_attribute (tree *node, tree name,
5897                              tree ARG_UNUSED (args),
5898                              int ARG_UNUSED (flags),
5899                              bool *no_add_attrs)
5900 {
5901   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
5902     {
5903       /* Do nothing else, just set the attribute.  We'll get at
5904          it later with lookup_attribute.  */
5905     }
5906   else
5907     {
5908       warning (OPT_Wattributes, "%qE attribute ignored", name);
5909       *no_add_attrs = true;
5910     }
5911
5912   return NULL_TREE;
5913 }
5914
5915 /* Handle an "artificial" attribute; arguments as in
5916    struct attribute_spec.handler.  */
5917
5918 static tree
5919 handle_artificial_attribute (tree *node, tree name,
5920                              tree ARG_UNUSED (args),
5921                              int ARG_UNUSED (flags),
5922                              bool *no_add_attrs)
5923 {
5924   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
5925     {
5926       /* Do nothing else, just set the attribute.  We'll get at
5927          it later with lookup_attribute.  */
5928     }
5929   else
5930     {
5931       warning (OPT_Wattributes, "%qE attribute ignored", name);
5932       *no_add_attrs = true;
5933     }
5934
5935   return NULL_TREE;
5936 }
5937
5938 /* Handle a "flatten" attribute; arguments as in
5939    struct attribute_spec.handler.  */
5940
5941 static tree
5942 handle_flatten_attribute (tree *node, tree name,
5943                           tree args ATTRIBUTE_UNUSED,
5944                           int flags ATTRIBUTE_UNUSED, bool *no_add_attrs)
5945 {
5946   if (TREE_CODE (*node) == FUNCTION_DECL)
5947     /* Do nothing else, just set the attribute.  We'll get at
5948        it later with lookup_attribute.  */
5949     ;
5950   else
5951     {
5952       warning (OPT_Wattributes, "%qE attribute ignored", name);
5953       *no_add_attrs = true;
5954     }
5955
5956   return NULL_TREE;
5957 }
5958
5959 /* Handle a "warning" or "error" attribute; arguments as in
5960    struct attribute_spec.handler.  */
5961
5962 static tree
5963 handle_error_attribute (tree *node, tree name, tree args,
5964                         int ARG_UNUSED (flags), bool *no_add_attrs)
5965 {
5966   if (TREE_CODE (*node) == FUNCTION_DECL
5967       || TREE_CODE (TREE_VALUE (args)) == STRING_CST)
5968     /* Do nothing else, just set the attribute.  We'll get at
5969        it later with lookup_attribute.  */
5970     ;
5971   else
5972     {
5973       warning (OPT_Wattributes, "%qE attribute ignored", name);
5974       *no_add_attrs = true;
5975     }
5976
5977   return NULL_TREE;
5978 }
5979
5980 /* Handle a "used" attribute; arguments as in
5981    struct attribute_spec.handler.  */
5982
5983 static tree
5984 handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
5985                        int ARG_UNUSED (flags), bool *no_add_attrs)
5986 {
5987   tree node = *pnode;
5988
5989   if (TREE_CODE (node) == FUNCTION_DECL
5990       || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node)))
5991     {
5992       TREE_USED (node) = 1;
5993       DECL_PRESERVE_P (node) = 1;
5994     }
5995   else
5996     {
5997       warning (OPT_Wattributes, "%qE attribute ignored", name);
5998       *no_add_attrs = true;
5999     }
6000
6001   return NULL_TREE;
6002 }
6003
6004 /* Handle a "unused" attribute; arguments as in
6005    struct attribute_spec.handler.  */
6006
6007 static tree
6008 handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6009                          int flags, bool *no_add_attrs)
6010 {
6011   if (DECL_P (*node))
6012     {
6013       tree decl = *node;
6014
6015       if (TREE_CODE (decl) == PARM_DECL
6016           || TREE_CODE (decl) == VAR_DECL
6017           || TREE_CODE (decl) == FUNCTION_DECL
6018           || TREE_CODE (decl) == LABEL_DECL
6019           || TREE_CODE (decl) == TYPE_DECL)
6020         TREE_USED (decl) = 1;
6021       else
6022         {
6023           warning (OPT_Wattributes, "%qE attribute ignored", name);
6024           *no_add_attrs = true;
6025         }
6026     }
6027   else
6028     {
6029       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6030         *node = build_variant_type_copy (*node);
6031       TREE_USED (*node) = 1;
6032     }
6033
6034   return NULL_TREE;
6035 }
6036
6037 /* Handle a "externally_visible" attribute; arguments as in
6038    struct attribute_spec.handler.  */
6039
6040 static tree
6041 handle_externally_visible_attribute (tree *pnode, tree name,
6042                                      tree ARG_UNUSED (args),
6043                                      int ARG_UNUSED (flags),
6044                                      bool *no_add_attrs)
6045 {
6046   tree node = *pnode;
6047
6048   if (TREE_CODE (node) == FUNCTION_DECL || TREE_CODE (node) == VAR_DECL)
6049     {
6050       if ((!TREE_STATIC (node) && TREE_CODE (node) != FUNCTION_DECL
6051            && !DECL_EXTERNAL (node)) || !TREE_PUBLIC (node))
6052         {
6053           warning (OPT_Wattributes,
6054                    "%qE attribute have effect only on public objects", name);
6055           *no_add_attrs = true;
6056         }
6057     }
6058   else
6059     {
6060       warning (OPT_Wattributes, "%qE attribute ignored", name);
6061       *no_add_attrs = true;
6062     }
6063
6064   return NULL_TREE;
6065 }
6066
6067 /* Handle a "const" attribute; arguments as in
6068    struct attribute_spec.handler.  */
6069
6070 static tree
6071 handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6072                         int ARG_UNUSED (flags), bool *no_add_attrs)
6073 {
6074   tree type = TREE_TYPE (*node);
6075
6076   /* See FIXME comment on noreturn in c_common_attribute_table.  */
6077   if (TREE_CODE (*node) == FUNCTION_DECL)
6078     TREE_READONLY (*node) = 1;
6079   else if (TREE_CODE (type) == POINTER_TYPE
6080            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
6081     TREE_TYPE (*node)
6082       = build_pointer_type
6083         (build_type_variant (TREE_TYPE (type), 1,
6084                              TREE_THIS_VOLATILE (TREE_TYPE (type))));
6085   else
6086     {
6087       warning (OPT_Wattributes, "%qE attribute ignored", name);
6088       *no_add_attrs = true;
6089     }
6090
6091   return NULL_TREE;
6092 }
6093
6094 /* Handle a "transparent_union" attribute; arguments as in
6095    struct attribute_spec.handler.  */
6096
6097 static tree
6098 handle_transparent_union_attribute (tree *node, tree name,
6099                                     tree ARG_UNUSED (args), int flags,
6100                                     bool *no_add_attrs)
6101 {
6102   tree type;
6103
6104   *no_add_attrs = true;
6105
6106   if (TREE_CODE (*node) == TYPE_DECL)
6107     node = &TREE_TYPE (*node);
6108   type = *node;
6109
6110   if (TREE_CODE (type) == UNION_TYPE)
6111     {
6112       /* When IN_PLACE is set, leave the check for FIELDS and MODE to
6113          the code in finish_struct.  */
6114       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6115         {
6116           if (TYPE_FIELDS (type) == NULL_TREE
6117               || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type)))
6118             goto ignored;
6119
6120           /* A type variant isn't good enough, since we don't a cast
6121              to such a type removed as a no-op.  */
6122           *node = type = build_duplicate_type (type);
6123         }
6124
6125       TYPE_TRANSPARENT_UNION (type) = 1;
6126       return NULL_TREE;
6127     }
6128
6129  ignored:
6130   warning (OPT_Wattributes, "%qE attribute ignored", name);
6131   return NULL_TREE;
6132 }
6133
6134 /* Subroutine of handle_{con,de}structor_attribute.  Evaluate ARGS to
6135    get the requested priority for a constructor or destructor,
6136    possibly issuing diagnostics for invalid or reserved
6137    priorities.  */
6138
6139 static priority_type
6140 get_priority (tree args, bool is_destructor)
6141 {
6142   HOST_WIDE_INT pri;
6143   tree arg;
6144
6145   if (!args)
6146     return DEFAULT_INIT_PRIORITY;
6147
6148   if (!SUPPORTS_INIT_PRIORITY)
6149     {
6150       if (is_destructor)
6151         error ("destructor priorities are not supported");
6152       else
6153         error ("constructor priorities are not supported");
6154       return DEFAULT_INIT_PRIORITY;
6155     }
6156
6157   arg = TREE_VALUE (args);
6158   if (!host_integerp (arg, /*pos=*/0)
6159       || !INTEGRAL_TYPE_P (TREE_TYPE (arg)))
6160     goto invalid;
6161
6162   pri = tree_low_cst (TREE_VALUE (args), /*pos=*/0);
6163   if (pri < 0 || pri > MAX_INIT_PRIORITY)
6164     goto invalid;
6165
6166   if (pri <= MAX_RESERVED_INIT_PRIORITY)
6167     {
6168       if (is_destructor)
6169         warning (0,
6170                  "destructor priorities from 0 to %d are reserved "
6171                  "for the implementation",
6172                  MAX_RESERVED_INIT_PRIORITY);
6173       else
6174         warning (0,
6175                  "constructor priorities from 0 to %d are reserved "
6176                  "for the implementation",
6177                  MAX_RESERVED_INIT_PRIORITY);
6178     }
6179   return pri;
6180
6181  invalid:
6182   if (is_destructor)
6183     error ("destructor priorities must be integers from 0 to %d inclusive",
6184            MAX_INIT_PRIORITY);
6185   else
6186     error ("constructor priorities must be integers from 0 to %d inclusive",
6187            MAX_INIT_PRIORITY);
6188   return DEFAULT_INIT_PRIORITY;
6189 }
6190
6191 /* Handle a "constructor" attribute; arguments as in
6192    struct attribute_spec.handler.  */
6193
6194 static tree
6195 handle_constructor_attribute (tree *node, tree name, tree args,
6196                               int ARG_UNUSED (flags),
6197                               bool *no_add_attrs)
6198 {
6199   tree decl = *node;
6200   tree type = TREE_TYPE (decl);
6201
6202   if (TREE_CODE (decl) == FUNCTION_DECL
6203       && TREE_CODE (type) == FUNCTION_TYPE
6204       && decl_function_context (decl) == 0)
6205     {
6206       priority_type priority;
6207       DECL_STATIC_CONSTRUCTOR (decl) = 1;
6208       priority = get_priority (args, /*is_destructor=*/false);
6209       SET_DECL_INIT_PRIORITY (decl, priority);
6210       TREE_USED (decl) = 1;
6211     }
6212   else
6213     {
6214       warning (OPT_Wattributes, "%qE attribute ignored", name);
6215       *no_add_attrs = true;
6216     }
6217
6218   return NULL_TREE;
6219 }
6220
6221 /* Handle a "destructor" attribute; arguments as in
6222    struct attribute_spec.handler.  */
6223
6224 static tree
6225 handle_destructor_attribute (tree *node, tree name, tree args,
6226                              int ARG_UNUSED (flags),
6227                              bool *no_add_attrs)
6228 {
6229   tree decl = *node;
6230   tree type = TREE_TYPE (decl);
6231
6232   if (TREE_CODE (decl) == FUNCTION_DECL
6233       && TREE_CODE (type) == FUNCTION_TYPE
6234       && decl_function_context (decl) == 0)
6235     {
6236       priority_type priority;
6237       DECL_STATIC_DESTRUCTOR (decl) = 1;
6238       priority = get_priority (args, /*is_destructor=*/true);
6239       SET_DECL_FINI_PRIORITY (decl, priority);
6240       TREE_USED (decl) = 1;
6241     }
6242   else
6243     {
6244       warning (OPT_Wattributes, "%qE attribute ignored", name);
6245       *no_add_attrs = true;
6246     }
6247
6248   return NULL_TREE;
6249 }
6250
6251 /* Handle a "mode" attribute; arguments as in
6252    struct attribute_spec.handler.  */
6253
6254 static tree
6255 handle_mode_attribute (tree *node, tree name, tree args,
6256                        int ARG_UNUSED (flags), bool *no_add_attrs)
6257 {
6258   tree type = *node;
6259   tree ident = TREE_VALUE (args);
6260
6261   *no_add_attrs = true;
6262
6263   if (TREE_CODE (ident) != IDENTIFIER_NODE)
6264     warning (OPT_Wattributes, "%qE attribute ignored", name);
6265   else
6266     {
6267       int j;
6268       const char *p = IDENTIFIER_POINTER (ident);
6269       int len = strlen (p);
6270       enum machine_mode mode = VOIDmode;
6271       tree typefm;
6272       bool valid_mode;
6273
6274       if (len > 4 && p[0] == '_' && p[1] == '_'
6275           && p[len - 1] == '_' && p[len - 2] == '_')
6276         {
6277           char *newp = (char *) alloca (len - 1);
6278
6279           strcpy (newp, &p[2]);
6280           newp[len - 4] = '\0';
6281           p = newp;
6282         }
6283
6284       /* Change this type to have a type with the specified mode.
6285          First check for the special modes.  */
6286       if (!strcmp (p, "byte"))
6287         mode = byte_mode;
6288       else if (!strcmp (p, "word"))
6289         mode = word_mode;
6290       else if (!strcmp (p, "pointer"))
6291         mode = ptr_mode;
6292       else if (!strcmp (p, "libgcc_cmp_return"))
6293         mode = targetm.libgcc_cmp_return_mode ();
6294       else if (!strcmp (p, "libgcc_shift_count"))
6295         mode = targetm.libgcc_shift_count_mode ();
6296       else if (!strcmp (p, "unwind_word"))
6297         mode = targetm.unwind_word_mode ();
6298       else
6299         for (j = 0; j < NUM_MACHINE_MODES; j++)
6300           if (!strcmp (p, GET_MODE_NAME (j)))
6301             {
6302               mode = (enum machine_mode) j;
6303               break;
6304             }
6305
6306       if (mode == VOIDmode)
6307         {
6308           error ("unknown machine mode %qE", ident);
6309           return NULL_TREE;
6310         }
6311
6312       valid_mode = false;
6313       switch (GET_MODE_CLASS (mode))
6314         {
6315         case MODE_INT:
6316         case MODE_PARTIAL_INT:
6317         case MODE_FLOAT:
6318         case MODE_DECIMAL_FLOAT:
6319         case MODE_FRACT:
6320         case MODE_UFRACT:
6321         case MODE_ACCUM:
6322         case MODE_UACCUM:
6323           valid_mode = targetm.scalar_mode_supported_p (mode);
6324           break;
6325
6326         case MODE_COMPLEX_INT:
6327         case MODE_COMPLEX_FLOAT:
6328           valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode));
6329           break;
6330
6331         case MODE_VECTOR_INT:
6332         case MODE_VECTOR_FLOAT:
6333         case MODE_VECTOR_FRACT:
6334         case MODE_VECTOR_UFRACT:
6335         case MODE_VECTOR_ACCUM:
6336         case MODE_VECTOR_UACCUM:
6337           warning (OPT_Wattributes, "specifying vector types with "
6338                    "__attribute__ ((mode)) is deprecated");
6339           warning (OPT_Wattributes,
6340                    "use __attribute__ ((vector_size)) instead");
6341           valid_mode = vector_mode_valid_p (mode);
6342           break;
6343
6344         default:
6345           break;
6346         }
6347       if (!valid_mode)
6348         {
6349           error ("unable to emulate %qs", p);
6350           return NULL_TREE;
6351         }
6352
6353       if (POINTER_TYPE_P (type))
6354         {
6355           tree (*fn)(tree, enum machine_mode, bool);
6356
6357           if (!targetm.valid_pointer_mode (mode))
6358             {
6359               error ("invalid pointer mode %qs", p);
6360               return NULL_TREE;
6361             }
6362
6363           if (TREE_CODE (type) == POINTER_TYPE)
6364             fn = build_pointer_type_for_mode;
6365           else
6366             fn = build_reference_type_for_mode;
6367           typefm = fn (TREE_TYPE (type), mode, false);
6368         }
6369       else
6370         {
6371           /* For fixed-point modes, we need to test if the signness of type
6372              and the machine mode are consistent.  */
6373           if (ALL_FIXED_POINT_MODE_P (mode)
6374               && TYPE_UNSIGNED (type) != UNSIGNED_FIXED_POINT_MODE_P (mode))
6375             {
6376               error ("signness of type and machine mode %qs don't match", p);
6377               return NULL_TREE;
6378             }
6379           /* For fixed-point modes, we need to pass saturating info.  */
6380           typefm = lang_hooks.types.type_for_mode (mode,
6381                         ALL_FIXED_POINT_MODE_P (mode) ? TYPE_SATURATING (type)
6382                                                       : TYPE_UNSIGNED (type));
6383         }
6384
6385       if (typefm == NULL_TREE)
6386         {
6387           error ("no data type for mode %qs", p);
6388           return NULL_TREE;
6389         }
6390       else if (TREE_CODE (type) == ENUMERAL_TYPE)
6391         {
6392           /* For enumeral types, copy the precision from the integer
6393              type returned above.  If not an INTEGER_TYPE, we can't use
6394              this mode for this type.  */
6395           if (TREE_CODE (typefm) != INTEGER_TYPE)
6396             {
6397               error ("cannot use mode %qs for enumeral types", p);
6398               return NULL_TREE;
6399             }
6400
6401           if (flags & ATTR_FLAG_TYPE_IN_PLACE)
6402             {
6403               TYPE_PRECISION (type) = TYPE_PRECISION (typefm);
6404               typefm = type;
6405             }
6406           else
6407             {
6408               /* We cannot build a type variant, as there's code that assumes
6409                  that TYPE_MAIN_VARIANT has the same mode.  This includes the
6410                  debug generators.  Instead, create a subrange type.  This
6411                  results in all of the enumeral values being emitted only once
6412                  in the original, and the subtype gets them by reference.  */
6413               if (TYPE_UNSIGNED (type))
6414                 typefm = make_unsigned_type (TYPE_PRECISION (typefm));
6415               else
6416                 typefm = make_signed_type (TYPE_PRECISION (typefm));
6417               TREE_TYPE (typefm) = type;
6418             }
6419         }
6420       else if (VECTOR_MODE_P (mode)
6421                ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm))
6422                : TREE_CODE (type) != TREE_CODE (typefm))
6423         {
6424           error ("mode %qs applied to inappropriate type", p);
6425           return NULL_TREE;
6426         }
6427
6428       *node = typefm;
6429     }
6430
6431   return NULL_TREE;
6432 }
6433
6434 /* Handle a "section" attribute; arguments as in
6435    struct attribute_spec.handler.  */
6436
6437 static tree
6438 handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6439                           int ARG_UNUSED (flags), bool *no_add_attrs)
6440 {
6441   tree decl = *node;
6442
6443   if (targetm.have_named_sections)
6444     {
6445       user_defined_section_attribute = true;
6446
6447       if ((TREE_CODE (decl) == FUNCTION_DECL
6448            || TREE_CODE (decl) == VAR_DECL)
6449           && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
6450         {
6451           if (TREE_CODE (decl) == VAR_DECL
6452               && current_function_decl != NULL_TREE
6453               && !TREE_STATIC (decl))
6454             {
6455               error ("%Jsection attribute cannot be specified for "
6456                      "local variables", decl);
6457               *no_add_attrs = true;
6458             }
6459
6460           /* The decl may have already been given a section attribute
6461              from a previous declaration.  Ensure they match.  */
6462           else if (DECL_SECTION_NAME (decl) != NULL_TREE
6463                    && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
6464                               TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
6465             {
6466               error ("section of %q+D conflicts with previous declaration",
6467                      *node);
6468               *no_add_attrs = true;
6469             }
6470           else if (TREE_CODE (decl) == VAR_DECL
6471                    && !targetm.have_tls && targetm.emutls.tmpl_section
6472                    && DECL_THREAD_LOCAL_P (decl))
6473             {
6474               error ("section of %q+D cannot be overridden", *node);
6475               *no_add_attrs = true;
6476             }
6477           else
6478             DECL_SECTION_NAME (decl) = TREE_VALUE (args);
6479         }
6480       else
6481         {
6482           error ("section attribute not allowed for %q+D", *node);
6483           *no_add_attrs = true;
6484         }
6485     }
6486   else
6487     {
6488       error ("%Jsection attributes are not supported for this target", *node);
6489       *no_add_attrs = true;
6490     }
6491
6492   return NULL_TREE;
6493 }
6494
6495 /* Handle a "aligned" attribute; arguments as in
6496    struct attribute_spec.handler.  */
6497
6498 static tree
6499 handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6500                           int flags, bool *no_add_attrs)
6501 {
6502   tree decl = NULL_TREE;
6503   tree *type = NULL;
6504   int is_type = 0;
6505   tree align_expr = (args ? TREE_VALUE (args)
6506                      : size_int (ATTRIBUTE_ALIGNED_VALUE / BITS_PER_UNIT));
6507   int i;
6508
6509   if (DECL_P (*node))
6510     {
6511       decl = *node;
6512       type = &TREE_TYPE (decl);
6513       is_type = TREE_CODE (*node) == TYPE_DECL;
6514     }
6515   else if (TYPE_P (*node))
6516     type = node, is_type = 1;
6517
6518   if (TREE_CODE (align_expr) != INTEGER_CST)
6519     {
6520       error ("requested alignment is not a constant");
6521       *no_add_attrs = true;
6522     }
6523   else if ((i = tree_log2 (align_expr)) == -1)
6524     {
6525       error ("requested alignment is not a power of 2");
6526       *no_add_attrs = true;
6527     }
6528   else if (i >= HOST_BITS_PER_INT - BITS_PER_UNIT_LOG)
6529     {
6530       error ("requested alignment is too large");
6531       *no_add_attrs = true;
6532     }
6533   else if (is_type)
6534     {
6535       /* If we have a TYPE_DECL, then copy the type, so that we
6536          don't accidentally modify a builtin type.  See pushdecl.  */
6537       if (decl && TREE_TYPE (decl) != error_mark_node
6538           && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
6539         {
6540           tree tt = TREE_TYPE (decl);
6541           *type = build_variant_type_copy (*type);
6542           DECL_ORIGINAL_TYPE (decl) = tt;
6543           TYPE_NAME (*type) = decl;
6544           TREE_USED (*type) = TREE_USED (decl);
6545           TREE_TYPE (decl) = *type;
6546         }
6547       else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6548         *type = build_variant_type_copy (*type);
6549
6550       TYPE_ALIGN (*type) = (1U << i) * BITS_PER_UNIT;
6551       TYPE_USER_ALIGN (*type) = 1;
6552     }
6553   else if (! VAR_OR_FUNCTION_DECL_P (decl)
6554            && TREE_CODE (decl) != FIELD_DECL)
6555     {
6556       error ("alignment may not be specified for %q+D", decl);
6557       *no_add_attrs = true;
6558     }
6559   else if (TREE_CODE (decl) == FUNCTION_DECL
6560            && DECL_ALIGN (decl) > (1U << i) * BITS_PER_UNIT)
6561     {
6562       if (DECL_USER_ALIGN (decl))
6563         error ("alignment for %q+D was previously specified as %d "
6564                "and may not be decreased", decl,
6565                DECL_ALIGN (decl) / BITS_PER_UNIT);
6566       else
6567         error ("alignment for %q+D must be at least %d", decl,
6568                DECL_ALIGN (decl) / BITS_PER_UNIT);
6569       *no_add_attrs = true;
6570     }
6571   else
6572     {
6573       DECL_ALIGN (decl) = (1U << i) * BITS_PER_UNIT;
6574       DECL_USER_ALIGN (decl) = 1;
6575     }
6576
6577   return NULL_TREE;
6578 }
6579
6580 /* Handle a "weak" attribute; arguments as in
6581    struct attribute_spec.handler.  */
6582
6583 static tree
6584 handle_weak_attribute (tree *node, tree name,
6585                        tree ARG_UNUSED (args),
6586                        int ARG_UNUSED (flags),
6587                        bool * ARG_UNUSED (no_add_attrs))
6588 {
6589   if (TREE_CODE (*node) == FUNCTION_DECL
6590       && DECL_DECLARED_INLINE_P (*node))
6591     {
6592       error ("inline function %q+D cannot be declared weak", *node);
6593       *no_add_attrs = true;
6594     }
6595   else if (TREE_CODE (*node) == FUNCTION_DECL
6596            || TREE_CODE (*node) == VAR_DECL)
6597     declare_weak (*node);
6598   else
6599     warning (OPT_Wattributes, "%qE attribute ignored", name);
6600
6601   return NULL_TREE;
6602 }
6603
6604 /* Handle an "alias" attribute; arguments as in
6605    struct attribute_spec.handler.  */
6606
6607 static tree
6608 handle_alias_attribute (tree *node, tree name, tree args,
6609                         int ARG_UNUSED (flags), bool *no_add_attrs)
6610 {
6611   tree decl = *node;
6612
6613   if (TREE_CODE (decl) != FUNCTION_DECL && TREE_CODE (decl) != VAR_DECL)
6614     {
6615       warning (OPT_Wattributes, "%qE attribute ignored", name);
6616       *no_add_attrs = true;
6617     }
6618   else if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
6619       || (TREE_CODE (decl) != FUNCTION_DECL
6620           && TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl))
6621       /* A static variable declaration is always a tentative definition,
6622          but the alias is a non-tentative definition which overrides.  */
6623       || (TREE_CODE (decl) != FUNCTION_DECL
6624           && ! TREE_PUBLIC (decl) && DECL_INITIAL (decl)))
6625     {
6626       error ("%q+D defined both normally and as an alias", decl);
6627       *no_add_attrs = true;
6628     }
6629
6630   /* Note that the very first time we process a nested declaration,
6631      decl_function_context will not be set.  Indeed, *would* never
6632      be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that
6633      we do below.  After such frobbery, pushdecl would set the context.
6634      In any case, this is never what we want.  */
6635   else if (decl_function_context (decl) == 0 && current_function_decl == NULL)
6636     {
6637       tree id;
6638
6639       id = TREE_VALUE (args);
6640       if (TREE_CODE (id) != STRING_CST)
6641         {
6642           error ("alias argument not a string");
6643           *no_add_attrs = true;
6644           return NULL_TREE;
6645         }
6646       id = get_identifier (TREE_STRING_POINTER (id));
6647       /* This counts as a use of the object pointed to.  */
6648       TREE_USED (id) = 1;
6649
6650       if (TREE_CODE (decl) == FUNCTION_DECL)
6651         DECL_INITIAL (decl) = error_mark_node;
6652       else
6653         {
6654           if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
6655             DECL_EXTERNAL (decl) = 1;
6656           else
6657             DECL_EXTERNAL (decl) = 0;
6658           TREE_STATIC (decl) = 1;
6659         }
6660     }
6661   else
6662     {
6663       warning (OPT_Wattributes, "%qE attribute ignored", name);
6664       *no_add_attrs = true;
6665     }
6666
6667   return NULL_TREE;
6668 }
6669
6670 /* Handle a "weakref" attribute; arguments as in struct
6671    attribute_spec.handler.  */
6672
6673 static tree
6674 handle_weakref_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6675                           int flags, bool *no_add_attrs)
6676 {
6677   tree attr = NULL_TREE;
6678
6679   /* We must ignore the attribute when it is associated with
6680      local-scoped decls, since attribute alias is ignored and many
6681      such symbols do not even have a DECL_WEAK field.  */
6682   if (decl_function_context (*node)
6683       || current_function_decl
6684       || (TREE_CODE (*node) != VAR_DECL && TREE_CODE (*node) != FUNCTION_DECL))
6685     {
6686       warning (OPT_Wattributes, "%qE attribute ignored", name);
6687       *no_add_attrs = true;
6688       return NULL_TREE;
6689     }
6690
6691   /* The idea here is that `weakref("name")' mutates into `weakref,
6692      alias("name")', and weakref without arguments, in turn,
6693      implicitly adds weak. */
6694
6695   if (args)
6696     {
6697       attr = tree_cons (get_identifier ("alias"), args, attr);
6698       attr = tree_cons (get_identifier ("weakref"), NULL_TREE, attr);
6699
6700       *no_add_attrs = true;
6701
6702       decl_attributes (node, attr, flags);
6703     }
6704   else
6705     {
6706       if (lookup_attribute ("alias", DECL_ATTRIBUTES (*node)))
6707         error ("%Jweakref attribute must appear before alias attribute",
6708                *node);
6709
6710       /* Can't call declare_weak because it wants this to be TREE_PUBLIC,
6711          and that isn't supported; and because it wants to add it to
6712          the list of weak decls, which isn't helpful.  */
6713       DECL_WEAK (*node) = 1;
6714     }
6715
6716   return NULL_TREE;
6717 }
6718
6719 /* Handle an "visibility" attribute; arguments as in
6720    struct attribute_spec.handler.  */
6721
6722 static tree
6723 handle_visibility_attribute (tree *node, tree name, tree args,
6724                              int ARG_UNUSED (flags),
6725                              bool *ARG_UNUSED (no_add_attrs))
6726 {
6727   tree decl = *node;
6728   tree id = TREE_VALUE (args);
6729   enum symbol_visibility vis;
6730
6731   if (TYPE_P (*node))
6732     {
6733       if (TREE_CODE (*node) == ENUMERAL_TYPE)
6734         /* OK */;
6735       else if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE)
6736         {
6737           warning (OPT_Wattributes, "%qE attribute ignored on non-class types",
6738                    name);
6739           return NULL_TREE;
6740         }
6741       else if (TYPE_FIELDS (*node))
6742         {
6743           error ("%qE attribute ignored because %qT is already defined",
6744                  name, *node);
6745           return NULL_TREE;
6746         }
6747     }
6748   else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl))
6749     {
6750       warning (OPT_Wattributes, "%qE attribute ignored", name);
6751       return NULL_TREE;
6752     }
6753
6754   if (TREE_CODE (id) != STRING_CST)
6755     {
6756       error ("visibility argument not a string");
6757       return NULL_TREE;
6758     }
6759
6760   /*  If this is a type, set the visibility on the type decl.  */
6761   if (TYPE_P (decl))
6762     {
6763       decl = TYPE_NAME (decl);
6764       if (!decl)
6765         return NULL_TREE;
6766       if (TREE_CODE (decl) == IDENTIFIER_NODE)
6767         {
6768            warning (OPT_Wattributes, "%qE attribute ignored on types",
6769                     name);
6770            return NULL_TREE;
6771         }
6772     }
6773
6774   if (strcmp (TREE_STRING_POINTER (id), "default") == 0)
6775     vis = VISIBILITY_DEFAULT;
6776   else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0)
6777     vis = VISIBILITY_INTERNAL;
6778   else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0)
6779     vis = VISIBILITY_HIDDEN;
6780   else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0)
6781     vis = VISIBILITY_PROTECTED;
6782   else
6783     {
6784       error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\"");
6785       vis = VISIBILITY_DEFAULT;
6786     }
6787
6788   if (DECL_VISIBILITY_SPECIFIED (decl)
6789       && vis != DECL_VISIBILITY (decl))
6790     {
6791       tree attributes = (TYPE_P (*node)
6792                          ? TYPE_ATTRIBUTES (*node)
6793                          : DECL_ATTRIBUTES (decl));
6794       if (lookup_attribute ("visibility", attributes))
6795         error ("%qD redeclared with different visibility", decl);
6796       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
6797                && lookup_attribute ("dllimport", attributes))
6798         error ("%qD was declared %qs which implies default visibility",
6799                decl, "dllimport");
6800       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
6801                && lookup_attribute ("dllexport", attributes))
6802         error ("%qD was declared %qs which implies default visibility",
6803                decl, "dllexport");
6804     }
6805
6806   DECL_VISIBILITY (decl) = vis;
6807   DECL_VISIBILITY_SPECIFIED (decl) = 1;
6808
6809   /* Go ahead and attach the attribute to the node as well.  This is needed
6810      so we can determine whether we have VISIBILITY_DEFAULT because the
6811      visibility was not specified, or because it was explicitly overridden
6812      from the containing scope.  */
6813
6814   return NULL_TREE;
6815 }
6816
6817 /* Determine the ELF symbol visibility for DECL, which is either a
6818    variable or a function.  It is an error to use this function if a
6819    definition of DECL is not available in this translation unit.
6820    Returns true if the final visibility has been determined by this
6821    function; false if the caller is free to make additional
6822    modifications.  */
6823
6824 bool
6825 c_determine_visibility (tree decl)
6826 {
6827   gcc_assert (TREE_CODE (decl) == VAR_DECL
6828               || TREE_CODE (decl) == FUNCTION_DECL);
6829
6830   /* If the user explicitly specified the visibility with an
6831      attribute, honor that.  DECL_VISIBILITY will have been set during
6832      the processing of the attribute.  We check for an explicit
6833      attribute, rather than just checking DECL_VISIBILITY_SPECIFIED,
6834      to distinguish the use of an attribute from the use of a "#pragma
6835      GCC visibility push(...)"; in the latter case we still want other
6836      considerations to be able to overrule the #pragma.  */
6837   if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl))
6838       || (TARGET_DLLIMPORT_DECL_ATTRIBUTES
6839           && (lookup_attribute ("dllimport", DECL_ATTRIBUTES (decl))
6840               || lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))))
6841     return true;
6842
6843   /* Set default visibility to whatever the user supplied with
6844      visibility_specified depending on #pragma GCC visibility.  */
6845   if (!DECL_VISIBILITY_SPECIFIED (decl))
6846     {
6847       if (visibility_options.inpragma
6848           || DECL_VISIBILITY (decl) != default_visibility)
6849         {
6850           DECL_VISIBILITY (decl) = default_visibility;
6851           DECL_VISIBILITY_SPECIFIED (decl) = visibility_options.inpragma;
6852           /* If visibility changed and DECL already has DECL_RTL, ensure
6853              symbol flags are updated.  */
6854           if (((TREE_CODE (decl) == VAR_DECL && TREE_STATIC (decl))
6855                || TREE_CODE (decl) == FUNCTION_DECL)
6856               && DECL_RTL_SET_P (decl))
6857             make_decl_rtl (decl);
6858         }
6859     }
6860   return false;
6861 }
6862
6863 /* Handle an "tls_model" attribute; arguments as in
6864    struct attribute_spec.handler.  */
6865
6866 static tree
6867 handle_tls_model_attribute (tree *node, tree name, tree args,
6868                             int ARG_UNUSED (flags), bool *no_add_attrs)
6869 {
6870   tree id;
6871   tree decl = *node;
6872   enum tls_model kind;
6873
6874   *no_add_attrs = true;
6875
6876   if (TREE_CODE (decl) != VAR_DECL || !DECL_THREAD_LOCAL_P (decl))
6877     {
6878       warning (OPT_Wattributes, "%qE attribute ignored", name);
6879       return NULL_TREE;
6880     }
6881
6882   kind = DECL_TLS_MODEL (decl);
6883   id = TREE_VALUE (args);
6884   if (TREE_CODE (id) != STRING_CST)
6885     {
6886       error ("tls_model argument not a string");
6887       return NULL_TREE;
6888     }
6889
6890   if (!strcmp (TREE_STRING_POINTER (id), "local-exec"))
6891     kind = TLS_MODEL_LOCAL_EXEC;
6892   else if (!strcmp (TREE_STRING_POINTER (id), "initial-exec"))
6893     kind = TLS_MODEL_INITIAL_EXEC;
6894   else if (!strcmp (TREE_STRING_POINTER (id), "local-dynamic"))
6895     kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
6896   else if (!strcmp (TREE_STRING_POINTER (id), "global-dynamic"))
6897     kind = TLS_MODEL_GLOBAL_DYNAMIC;
6898   else
6899     error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\"");
6900
6901   DECL_TLS_MODEL (decl) = kind;
6902   return NULL_TREE;
6903 }
6904
6905 /* Handle a "no_instrument_function" attribute; arguments as in
6906    struct attribute_spec.handler.  */
6907
6908 static tree
6909 handle_no_instrument_function_attribute (tree *node, tree name,
6910                                          tree ARG_UNUSED (args),
6911                                          int ARG_UNUSED (flags),
6912                                          bool *no_add_attrs)
6913 {
6914   tree decl = *node;
6915
6916   if (TREE_CODE (decl) != FUNCTION_DECL)
6917     {
6918       error ("%J%qE attribute applies only to functions", decl, name);
6919       *no_add_attrs = true;
6920     }
6921   else if (DECL_INITIAL (decl))
6922     {
6923       error ("%Jcan%'t set %qE attribute after definition", decl, name);
6924       *no_add_attrs = true;
6925     }
6926   else
6927     DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
6928
6929   return NULL_TREE;
6930 }
6931
6932 /* Handle a "malloc" attribute; arguments as in
6933    struct attribute_spec.handler.  */
6934
6935 static tree
6936 handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6937                          int ARG_UNUSED (flags), bool *no_add_attrs)
6938 {
6939   if (TREE_CODE (*node) == FUNCTION_DECL
6940       && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node))))
6941     DECL_IS_MALLOC (*node) = 1;
6942   else
6943     {
6944       warning (OPT_Wattributes, "%qE attribute ignored", name);
6945       *no_add_attrs = true;
6946     }
6947
6948   return NULL_TREE;
6949 }
6950
6951 /* Handle a "alloc_size" attribute; arguments as in
6952    struct attribute_spec.handler.  */
6953
6954 static tree
6955 handle_alloc_size_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6956                              int ARG_UNUSED (flags), bool *no_add_attrs)
6957 {
6958   unsigned arg_count = type_num_arguments (*node);
6959   for (; args; args = TREE_CHAIN (args))
6960     {
6961       tree position = TREE_VALUE (args);
6962
6963       if (TREE_CODE (position) != INTEGER_CST
6964           || TREE_INT_CST_HIGH (position)
6965           || TREE_INT_CST_LOW (position) < 1
6966           || TREE_INT_CST_LOW (position) > arg_count )
6967         {
6968           warning (OPT_Wattributes,
6969                    "alloc_size parameter outside range");
6970           *no_add_attrs = true;
6971           return NULL_TREE;
6972         }
6973     }
6974   return NULL_TREE;
6975 }
6976
6977 /* Handle a "returns_twice" attribute; arguments as in
6978    struct attribute_spec.handler.  */
6979
6980 static tree
6981 handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6982                          int ARG_UNUSED (flags), bool *no_add_attrs)
6983 {
6984   if (TREE_CODE (*node) == FUNCTION_DECL)
6985     DECL_IS_RETURNS_TWICE (*node) = 1;
6986   else
6987     {
6988       warning (OPT_Wattributes, "%qE attribute ignored", name);
6989       *no_add_attrs = true;
6990     }
6991
6992   return NULL_TREE;
6993 }
6994
6995 /* Handle a "no_limit_stack" attribute; arguments as in
6996    struct attribute_spec.handler.  */
6997
6998 static tree
6999 handle_no_limit_stack_attribute (tree *node, tree name,
7000                                  tree ARG_UNUSED (args),
7001                                  int ARG_UNUSED (flags),
7002                                  bool *no_add_attrs)
7003 {
7004   tree decl = *node;
7005
7006   if (TREE_CODE (decl) != FUNCTION_DECL)
7007     {
7008       error ("%J%qE attribute applies only to functions", decl, name);
7009       *no_add_attrs = true;
7010     }
7011   else if (DECL_INITIAL (decl))
7012     {
7013       error ("%Jcan%'t set %qE attribute after definition", decl, name);
7014       *no_add_attrs = true;
7015     }
7016   else
7017     DECL_NO_LIMIT_STACK (decl) = 1;
7018
7019   return NULL_TREE;
7020 }
7021
7022 /* Handle a "pure" attribute; arguments as in
7023    struct attribute_spec.handler.  */
7024
7025 static tree
7026 handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7027                        int ARG_UNUSED (flags), bool *no_add_attrs)
7028 {
7029   if (TREE_CODE (*node) == FUNCTION_DECL)
7030     DECL_PURE_P (*node) = 1;
7031   /* ??? TODO: Support types.  */
7032   else
7033     {
7034       warning (OPT_Wattributes, "%qE attribute ignored", name);
7035       *no_add_attrs = true;
7036     }
7037
7038   return NULL_TREE;
7039 }
7040
7041 /* Handle a "no vops" attribute; arguments as in
7042    struct attribute_spec.handler.  */
7043
7044 static tree
7045 handle_novops_attribute (tree *node, tree ARG_UNUSED (name),
7046                          tree ARG_UNUSED (args), int ARG_UNUSED (flags),
7047                          bool *ARG_UNUSED (no_add_attrs))
7048 {
7049   gcc_assert (TREE_CODE (*node) == FUNCTION_DECL);
7050   DECL_IS_NOVOPS (*node) = 1;
7051   return NULL_TREE;
7052 }
7053
7054 /* Handle a "deprecated" attribute; arguments as in
7055    struct attribute_spec.handler.  */
7056
7057 static tree
7058 handle_deprecated_attribute (tree *node, tree name,
7059                              tree args, int flags,
7060                              bool *no_add_attrs)
7061 {
7062   tree type = NULL_TREE;
7063   int warn = 0;
7064   tree what = NULL_TREE;
7065
7066   if (!args)
7067     *no_add_attrs = true;
7068   else if (TREE_CODE (TREE_VALUE (args)) != STRING_CST)
7069     {
7070       error ("deprecated message is not a string");
7071       *no_add_attrs = true;
7072     }
7073
7074   if (DECL_P (*node))
7075     {
7076       tree decl = *node;
7077       type = TREE_TYPE (decl);
7078
7079       if (TREE_CODE (decl) == TYPE_DECL
7080           || TREE_CODE (decl) == PARM_DECL
7081           || TREE_CODE (decl) == VAR_DECL
7082           || TREE_CODE (decl) == FUNCTION_DECL
7083           || TREE_CODE (decl) == FIELD_DECL)
7084         TREE_DEPRECATED (decl) = 1;
7085       else
7086         warn = 1;
7087     }
7088   else if (TYPE_P (*node))
7089     {
7090       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
7091         *node = build_variant_type_copy (*node);
7092       TREE_DEPRECATED (*node) = 1;
7093       type = *node;
7094     }
7095   else
7096     warn = 1;
7097
7098   if (warn)
7099     {
7100       *no_add_attrs = true;
7101       if (type && TYPE_NAME (type))
7102         {
7103           if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
7104             what = TYPE_NAME (*node);
7105           else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
7106                    && DECL_NAME (TYPE_NAME (type)))
7107             what = DECL_NAME (TYPE_NAME (type));
7108         }
7109       if (what)
7110         warning (OPT_Wattributes, "%qE attribute ignored for %qE", name, what);
7111       else
7112         warning (OPT_Wattributes, "%qE attribute ignored", name);
7113     }
7114
7115   return NULL_TREE;
7116 }
7117
7118 /* Handle a "vector_size" attribute; arguments as in
7119    struct attribute_spec.handler.  */
7120
7121 static tree
7122 handle_vector_size_attribute (tree *node, tree name, tree args,
7123                               int ARG_UNUSED (flags),
7124                               bool *no_add_attrs)
7125 {
7126   unsigned HOST_WIDE_INT vecsize, nunits;
7127   enum machine_mode orig_mode;
7128   tree type = *node, new_type, size;
7129
7130   *no_add_attrs = true;
7131
7132   size = TREE_VALUE (args);
7133
7134   if (!host_integerp (size, 1))
7135     {
7136       warning (OPT_Wattributes, "%qE attribute ignored", name);
7137       return NULL_TREE;
7138     }
7139
7140   /* Get the vector size (in bytes).  */
7141   vecsize = tree_low_cst (size, 1);
7142
7143   /* We need to provide for vector pointers, vector arrays, and
7144      functions returning vectors.  For example:
7145
7146        __attribute__((vector_size(16))) short *foo;
7147
7148      In this case, the mode is SI, but the type being modified is
7149      HI, so we need to look further.  */
7150
7151   while (POINTER_TYPE_P (type)
7152          || TREE_CODE (type) == FUNCTION_TYPE
7153          || TREE_CODE (type) == METHOD_TYPE
7154          || TREE_CODE (type) == ARRAY_TYPE
7155          || TREE_CODE (type) == OFFSET_TYPE)
7156     type = TREE_TYPE (type);
7157
7158   /* Get the mode of the type being modified.  */
7159   orig_mode = TYPE_MODE (type);
7160
7161   if ((!INTEGRAL_TYPE_P (type)
7162        && !SCALAR_FLOAT_TYPE_P (type)
7163        && !FIXED_POINT_TYPE_P (type))
7164       || (!SCALAR_FLOAT_MODE_P (orig_mode)
7165           && GET_MODE_CLASS (orig_mode) != MODE_INT
7166           && !ALL_SCALAR_FIXED_POINT_MODE_P (orig_mode))
7167       || !host_integerp (TYPE_SIZE_UNIT (type), 1)
7168       || TREE_CODE (type) == BOOLEAN_TYPE)
7169     {
7170       error ("invalid vector type for attribute %qE", name);
7171       return NULL_TREE;
7172     }
7173
7174   if (vecsize % tree_low_cst (TYPE_SIZE_UNIT (type), 1))
7175     {
7176       error ("vector size not an integral multiple of component size");
7177       return NULL;
7178     }
7179
7180   if (vecsize == 0)
7181     {
7182       error ("zero vector size");
7183       return NULL;
7184     }
7185
7186   /* Calculate how many units fit in the vector.  */
7187   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
7188   if (nunits & (nunits - 1))
7189     {
7190       error ("number of components of the vector not a power of two");
7191       return NULL_TREE;
7192     }
7193
7194   new_type = build_vector_type (type, nunits);
7195
7196   /* Build back pointers if needed.  */
7197   *node = lang_hooks.types.reconstruct_complex_type (*node, new_type);
7198
7199   return NULL_TREE;
7200 }
7201
7202 /* Handle the "nonnull" attribute.  */
7203 static tree
7204 handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
7205                           tree args, int ARG_UNUSED (flags),
7206                           bool *no_add_attrs)
7207 {
7208   tree type = *node;
7209   unsigned HOST_WIDE_INT attr_arg_num;
7210
7211   /* If no arguments are specified, all pointer arguments should be
7212      non-null.  Verify a full prototype is given so that the arguments
7213      will have the correct types when we actually check them later.  */
7214   if (!args)
7215     {
7216       if (!TYPE_ARG_TYPES (type))
7217         {
7218           error ("nonnull attribute without arguments on a non-prototype");
7219           *no_add_attrs = true;
7220         }
7221       return NULL_TREE;
7222     }
7223
7224   /* Argument list specified.  Verify that each argument number references
7225      a pointer argument.  */
7226   for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
7227     {
7228       tree argument;
7229       unsigned HOST_WIDE_INT arg_num = 0, ck_num;
7230
7231       if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
7232         {
7233           error ("nonnull argument has invalid operand number (argument %lu)",
7234                  (unsigned long) attr_arg_num);
7235           *no_add_attrs = true;
7236           return NULL_TREE;
7237         }
7238
7239       argument = TYPE_ARG_TYPES (type);
7240       if (argument)
7241         {
7242           for (ck_num = 1; ; ck_num++)
7243             {
7244               if (!argument || ck_num == arg_num)
7245                 break;
7246               argument = TREE_CHAIN (argument);
7247             }
7248
7249           if (!argument
7250               || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
7251             {
7252               error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)",
7253                      (unsigned long) attr_arg_num, (unsigned long) arg_num);
7254               *no_add_attrs = true;
7255               return NULL_TREE;
7256             }
7257
7258           if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
7259             {
7260               error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)",
7261                    (unsigned long) attr_arg_num, (unsigned long) arg_num);
7262               *no_add_attrs = true;
7263               return NULL_TREE;
7264             }
7265         }
7266     }
7267
7268   return NULL_TREE;
7269 }
7270
7271 /* Check the argument list of a function call for null in argument slots
7272    that are marked as requiring a non-null pointer argument.  The NARGS
7273    arguments are passed in the array ARGARRAY.
7274 */
7275
7276 static void
7277 check_function_nonnull (tree attrs, int nargs, tree *argarray)
7278 {
7279   tree a, args;
7280   int i;
7281
7282   for (a = attrs; a; a = TREE_CHAIN (a))
7283     {
7284       if (is_attribute_p ("nonnull", TREE_PURPOSE (a)))
7285         {
7286           args = TREE_VALUE (a);
7287
7288           /* Walk the argument list.  If we encounter an argument number we
7289              should check for non-null, do it.  If the attribute has no args,
7290              then every pointer argument is checked (in which case the check
7291              for pointer type is done in check_nonnull_arg).  */
7292           for (i = 0; i < nargs; i++)
7293             {
7294               if (!args || nonnull_check_p (args, i + 1))
7295                 check_function_arguments_recurse (check_nonnull_arg, NULL,
7296                                                   argarray[i],
7297                                                   i + 1);
7298             }
7299         }
7300     }
7301 }
7302
7303 /* Check that the Nth argument of a function call (counting backwards
7304    from the end) is a (pointer)0.  The NARGS arguments are passed in the
7305    array ARGARRAY.  */
7306
7307 static void
7308 check_function_sentinel (tree attrs, int nargs, tree *argarray, tree typelist)
7309 {
7310   tree attr = lookup_attribute ("sentinel", attrs);
7311
7312   if (attr)
7313     {
7314       int len = 0;
7315       int pos = 0;
7316       tree sentinel;
7317
7318       /* Skip over the named arguments.  */
7319       while (typelist && len < nargs)
7320         {
7321           typelist = TREE_CHAIN (typelist);
7322           len++;
7323         }
7324
7325       if (TREE_VALUE (attr))
7326         {
7327           tree p = TREE_VALUE (TREE_VALUE (attr));
7328           pos = TREE_INT_CST_LOW (p);
7329         }
7330
7331       /* The sentinel must be one of the varargs, i.e.
7332          in position >= the number of fixed arguments.  */
7333       if ((nargs - 1 - pos) < len)
7334         {
7335           warning (OPT_Wformat,
7336                    "not enough variable arguments to fit a sentinel");
7337           return;
7338         }
7339
7340       /* Validate the sentinel.  */
7341       sentinel = argarray[nargs - 1 - pos];
7342       if ((!POINTER_TYPE_P (TREE_TYPE (sentinel))
7343            || !integer_zerop (sentinel))
7344           /* Although __null (in C++) is only an integer we allow it
7345              nevertheless, as we are guaranteed that it's exactly
7346              as wide as a pointer, and we don't want to force
7347              users to cast the NULL they have written there.
7348              We warn with -Wstrict-null-sentinel, though.  */
7349           && (warn_strict_null_sentinel || null_node != sentinel))
7350         warning (OPT_Wformat, "missing sentinel in function call");
7351     }
7352 }
7353
7354 /* Helper for check_function_nonnull; given a list of operands which
7355    must be non-null in ARGS, determine if operand PARAM_NUM should be
7356    checked.  */
7357
7358 static bool
7359 nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num)
7360 {
7361   unsigned HOST_WIDE_INT arg_num = 0;
7362
7363   for (; args; args = TREE_CHAIN (args))
7364     {
7365       bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num);
7366
7367       gcc_assert (found);
7368
7369       if (arg_num == param_num)
7370         return true;
7371     }
7372   return false;
7373 }
7374
7375 /* Check that the function argument PARAM (which is operand number
7376    PARAM_NUM) is non-null.  This is called by check_function_nonnull
7377    via check_function_arguments_recurse.  */
7378
7379 static void
7380 check_nonnull_arg (void * ARG_UNUSED (ctx), tree param,
7381                    unsigned HOST_WIDE_INT param_num)
7382 {
7383   /* Just skip checking the argument if it's not a pointer.  This can
7384      happen if the "nonnull" attribute was given without an operand
7385      list (which means to check every pointer argument).  */
7386
7387   if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE)
7388     return;
7389
7390   if (integer_zerop (param))
7391     warning (OPT_Wnonnull, "null argument where non-null required "
7392              "(argument %lu)", (unsigned long) param_num);
7393 }
7394
7395 /* Helper for nonnull attribute handling; fetch the operand number
7396    from the attribute argument list.  */
7397
7398 static bool
7399 get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp)
7400 {
7401   /* Verify the arg number is a constant.  */
7402   if (TREE_CODE (arg_num_expr) != INTEGER_CST
7403       || TREE_INT_CST_HIGH (arg_num_expr) != 0)
7404     return false;
7405
7406   *valp = TREE_INT_CST_LOW (arg_num_expr);
7407   return true;
7408 }
7409
7410 /* Handle a "nothrow" attribute; arguments as in
7411    struct attribute_spec.handler.  */
7412
7413 static tree
7414 handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7415                           int ARG_UNUSED (flags), bool *no_add_attrs)
7416 {
7417   if (TREE_CODE (*node) == FUNCTION_DECL)
7418     TREE_NOTHROW (*node) = 1;
7419   /* ??? TODO: Support types.  */
7420   else
7421     {
7422       warning (OPT_Wattributes, "%qE attribute ignored", name);
7423       *no_add_attrs = true;
7424     }
7425
7426   return NULL_TREE;
7427 }
7428
7429 /* Handle a "cleanup" attribute; arguments as in
7430    struct attribute_spec.handler.  */
7431
7432 static tree
7433 handle_cleanup_attribute (tree *node, tree name, tree args,
7434                           int ARG_UNUSED (flags), bool *no_add_attrs)
7435 {
7436   tree decl = *node;
7437   tree cleanup_id, cleanup_decl;
7438
7439   /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do
7440      for global destructors in C++.  This requires infrastructure that
7441      we don't have generically at the moment.  It's also not a feature
7442      we'd be missing too much, since we do have attribute constructor.  */
7443   if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl))
7444     {
7445       warning (OPT_Wattributes, "%qE attribute ignored", name);
7446       *no_add_attrs = true;
7447       return NULL_TREE;
7448     }
7449
7450   /* Verify that the argument is a function in scope.  */
7451   /* ??? We could support pointers to functions here as well, if
7452      that was considered desirable.  */
7453   cleanup_id = TREE_VALUE (args);
7454   if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE)
7455     {
7456       error ("cleanup argument not an identifier");
7457       *no_add_attrs = true;
7458       return NULL_TREE;
7459     }
7460   cleanup_decl = lookup_name (cleanup_id);
7461   if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL)
7462     {
7463       error ("cleanup argument not a function");
7464       *no_add_attrs = true;
7465       return NULL_TREE;
7466     }
7467
7468   /* That the function has proper type is checked with the
7469      eventual call to build_function_call.  */
7470
7471   return NULL_TREE;
7472 }
7473
7474 /* Handle a "warn_unused_result" attribute.  No special handling.  */
7475
7476 static tree
7477 handle_warn_unused_result_attribute (tree *node, tree name,
7478                                tree ARG_UNUSED (args),
7479                                int ARG_UNUSED (flags), bool *no_add_attrs)
7480 {
7481   /* Ignore the attribute for functions not returning any value.  */
7482   if (VOID_TYPE_P (TREE_TYPE (*node)))
7483     {
7484       warning (OPT_Wattributes, "%qE attribute ignored", name);
7485       *no_add_attrs = true;
7486     }
7487
7488   return NULL_TREE;
7489 }
7490
7491 /* Handle a "sentinel" attribute.  */
7492
7493 static tree
7494 handle_sentinel_attribute (tree *node, tree name, tree args,
7495                            int ARG_UNUSED (flags), bool *no_add_attrs)
7496 {
7497   tree params = TYPE_ARG_TYPES (*node);
7498
7499   if (!params)
7500     {
7501       warning (OPT_Wattributes,
7502                "%qE attribute requires prototypes with named arguments", name);
7503       *no_add_attrs = true;
7504     }
7505   else
7506     {
7507       while (TREE_CHAIN (params))
7508         params = TREE_CHAIN (params);
7509
7510       if (VOID_TYPE_P (TREE_VALUE (params)))
7511         {
7512           warning (OPT_Wattributes,
7513                    "%qE attribute only applies to variadic functions", name);
7514           *no_add_attrs = true;
7515         }
7516     }
7517
7518   if (args)
7519     {
7520       tree position = TREE_VALUE (args);
7521
7522       if (TREE_CODE (position) != INTEGER_CST)
7523         {
7524           warning (OPT_Wattributes,
7525                    "requested position is not an integer constant");
7526           *no_add_attrs = true;
7527         }
7528       else
7529         {
7530           if (tree_int_cst_lt (position, integer_zero_node))
7531             {
7532               warning (OPT_Wattributes,
7533                        "requested position is less than zero");
7534               *no_add_attrs = true;
7535             }
7536         }
7537     }
7538
7539   return NULL_TREE;
7540 }
7541
7542 /* Handle a "type_generic" attribute.  */
7543
7544 static tree
7545 handle_type_generic_attribute (tree *node, tree ARG_UNUSED (name),
7546                                tree ARG_UNUSED (args), int ARG_UNUSED (flags),
7547                                bool * ARG_UNUSED (no_add_attrs))
7548 {
7549   tree params;
7550
7551   /* Ensure we have a function type.  */
7552   gcc_assert (TREE_CODE (*node) == FUNCTION_TYPE);
7553
7554   params = TYPE_ARG_TYPES (*node);
7555   while (params && ! VOID_TYPE_P (TREE_VALUE (params)))
7556     params = TREE_CHAIN (params);
7557
7558   /* Ensure we have a variadic function.  */
7559   gcc_assert (!params);
7560
7561   return NULL_TREE;
7562 }
7563
7564 /* Handle a "target" attribute.  */
7565
7566 static tree
7567 handle_target_attribute (tree *node, tree name, tree args, int flags,
7568                          bool *no_add_attrs)
7569 {
7570   /* Ensure we have a function type.  */
7571   if (TREE_CODE (*node) != FUNCTION_DECL)
7572     {
7573       warning (OPT_Wattributes, "%qE attribute ignored", name);
7574       *no_add_attrs = true;
7575     }
7576   else if (! targetm.target_option.valid_attribute_p (*node, name, args,
7577                                                       flags))
7578     *no_add_attrs = true;
7579
7580   return NULL_TREE;
7581 }
7582
7583 /* Arguments being collected for optimization.  */
7584 typedef const char *const_char_p;               /* For DEF_VEC_P.  */
7585 DEF_VEC_P(const_char_p);
7586 DEF_VEC_ALLOC_P(const_char_p, gc);
7587 static GTY(()) VEC(const_char_p, gc) *optimize_args;
7588
7589
7590 /* Inner function to convert a TREE_LIST to argv string to parse the optimize
7591    options in ARGS.  ATTR_P is true if this is for attribute(optimize), and
7592    false for #pragma GCC optimize.  */
7593
7594 bool
7595 parse_optimize_options (tree args, bool attr_p)
7596 {
7597   bool ret = true;
7598   unsigned opt_argc;
7599   unsigned i;
7600   int saved_flag_strict_aliasing;
7601   const char **opt_argv;
7602   tree ap;
7603
7604   /* Build up argv vector.  Just in case the string is stored away, use garbage
7605      collected strings.  */
7606   VEC_truncate (const_char_p, optimize_args, 0);
7607   VEC_safe_push (const_char_p, gc, optimize_args, NULL);
7608
7609   for (ap = args; ap != NULL_TREE; ap = TREE_CHAIN (ap))
7610     {
7611       tree value = TREE_VALUE (ap);
7612
7613       if (TREE_CODE (value) == INTEGER_CST)
7614         {
7615           char buffer[20];
7616           sprintf (buffer, "-O%ld", (long) TREE_INT_CST_LOW (value));
7617           VEC_safe_push (const_char_p, gc, optimize_args, ggc_strdup (buffer));
7618         }
7619
7620       else if (TREE_CODE (value) == STRING_CST)
7621         {
7622           /* Split string into multiple substrings.  */
7623           size_t len = TREE_STRING_LENGTH (value);
7624           char *p = ASTRDUP (TREE_STRING_POINTER (value));
7625           char *end = p + len;
7626           char *comma;
7627           char *next_p = p;
7628
7629           while (next_p != NULL)
7630             {
7631               size_t len2;
7632               char *q, *r;
7633
7634               p = next_p;
7635               comma = strchr (p, ',');
7636               if (comma)
7637                 {
7638                   len2 = comma - p;
7639                   *comma = '\0';
7640                   next_p = comma+1;
7641                 }
7642               else
7643                 {
7644                   len2 = end - p;
7645                   next_p = NULL;
7646                 }
7647
7648               r = q = (char *) ggc_alloc (len2 + 3);
7649
7650               /* If the user supplied -Oxxx or -fxxx, only allow -Oxxx or -fxxx
7651                  options.  */
7652               if (*p == '-' && p[1] != 'O' && p[1] != 'f')
7653                 {
7654                   ret = false;
7655                   if (attr_p)
7656                     warning (OPT_Wattributes,
7657                              "Bad option %s to optimize attribute.", p);
7658                   else
7659                     warning (OPT_Wpragmas,
7660                              "Bad option %s to pragma attribute", p);
7661                   continue;
7662                 }
7663
7664               if (*p != '-')
7665                 {
7666                   *r++ = '-';
7667
7668                   /* Assume that Ox is -Ox, a numeric value is -Ox, a s by
7669                      itself is -Os, and any other switch begins with a -f.  */
7670                   if ((*p >= '0' && *p <= '9')
7671                       || (p[0] == 's' && p[1] == '\0'))
7672                     *r++ = 'O';
7673                   else if (*p != 'O')
7674                     *r++ = 'f';
7675                 }
7676
7677               memcpy (r, p, len2);
7678               r[len2] = '\0';
7679               VEC_safe_push (const_char_p, gc, optimize_args, q);
7680             }
7681
7682         }
7683     }
7684
7685   opt_argc = VEC_length (const_char_p, optimize_args);
7686   opt_argv = (const char **) alloca (sizeof (char *) * (opt_argc + 1));
7687
7688   for (i = 1; i < opt_argc; i++)
7689     opt_argv[i] = VEC_index (const_char_p, optimize_args, i);
7690
7691   saved_flag_strict_aliasing = flag_strict_aliasing;
7692
7693   /* Now parse the options.  */
7694   decode_options (opt_argc, opt_argv);
7695
7696   /* Don't allow changing -fstrict-aliasing.  */
7697   flag_strict_aliasing = saved_flag_strict_aliasing;
7698
7699   VEC_truncate (const_char_p, optimize_args, 0);
7700   return ret;
7701 }
7702
7703 /* For handling "optimize" attribute. arguments as in
7704    struct attribute_spec.handler.  */
7705
7706 static tree
7707 handle_optimize_attribute (tree *node, tree name, tree args,
7708                            int ARG_UNUSED (flags), bool *no_add_attrs)
7709 {
7710   /* Ensure we have a function type.  */
7711   if (TREE_CODE (*node) != FUNCTION_DECL)
7712     {
7713       warning (OPT_Wattributes, "%qE attribute ignored", name);
7714       *no_add_attrs = true;
7715     }
7716   else
7717     {
7718       struct cl_optimization cur_opts;
7719       tree old_opts = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node);
7720
7721       /* Save current options.  */
7722       cl_optimization_save (&cur_opts);
7723
7724       /* If we previously had some optimization options, use them as the
7725          default.  */
7726       if (old_opts)
7727         cl_optimization_restore (TREE_OPTIMIZATION (old_opts));
7728
7729       /* Parse options, and update the vector.  */
7730       parse_optimize_options (args, true);
7731       DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node)
7732         = build_optimization_node ();
7733
7734       /* Restore current options.  */
7735       cl_optimization_restore (&cur_opts);
7736     }
7737
7738   return NULL_TREE;
7739 }
7740 \f
7741 /* Check for valid arguments being passed to a function.
7742    ATTRS is a list of attributes.  There are NARGS arguments in the array
7743    ARGARRAY.  TYPELIST is the list of argument types for the function.
7744  */
7745 void
7746 check_function_arguments (tree attrs, int nargs, tree *argarray, tree typelist)
7747 {
7748   /* Check for null being passed in a pointer argument that must be
7749      non-null.  We also need to do this if format checking is enabled.  */
7750
7751   if (warn_nonnull)
7752     check_function_nonnull (attrs, nargs, argarray);
7753
7754   /* Check for errors in format strings.  */
7755
7756   if (warn_format || warn_missing_format_attribute)
7757     check_function_format (attrs, nargs, argarray);
7758
7759   if (warn_format)
7760     check_function_sentinel (attrs, nargs, argarray, typelist);
7761 }
7762
7763 /* Generic argument checking recursion routine.  PARAM is the argument to
7764    be checked.  PARAM_NUM is the number of the argument.  CALLBACK is invoked
7765    once the argument is resolved.  CTX is context for the callback.  */
7766 void
7767 check_function_arguments_recurse (void (*callback)
7768                                   (void *, tree, unsigned HOST_WIDE_INT),
7769                                   void *ctx, tree param,
7770                                   unsigned HOST_WIDE_INT param_num)
7771 {
7772   if (CONVERT_EXPR_P (param)
7773       && (TYPE_PRECISION (TREE_TYPE (param))
7774           == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (param, 0)))))
7775     {
7776       /* Strip coercion.  */
7777       check_function_arguments_recurse (callback, ctx,
7778                                         TREE_OPERAND (param, 0), param_num);
7779       return;
7780     }
7781
7782   if (TREE_CODE (param) == CALL_EXPR)
7783     {
7784       tree type = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (param)));
7785       tree attrs;
7786       bool found_format_arg = false;
7787
7788       /* See if this is a call to a known internationalization function
7789          that modifies a format arg.  Such a function may have multiple
7790          format_arg attributes (for example, ngettext).  */
7791
7792       for (attrs = TYPE_ATTRIBUTES (type);
7793            attrs;
7794            attrs = TREE_CHAIN (attrs))
7795         if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs)))
7796           {
7797             tree inner_arg;
7798             tree format_num_expr;
7799             int format_num;
7800             int i;
7801             call_expr_arg_iterator iter;
7802
7803             /* Extract the argument number, which was previously checked
7804                to be valid.  */
7805             format_num_expr = TREE_VALUE (TREE_VALUE (attrs));
7806
7807             gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST
7808                         && !TREE_INT_CST_HIGH (format_num_expr));
7809
7810             format_num = TREE_INT_CST_LOW (format_num_expr);
7811
7812             for (inner_arg = first_call_expr_arg (param, &iter), i = 1;
7813                  inner_arg != 0;
7814                  inner_arg = next_call_expr_arg (&iter), i++)
7815               if (i == format_num)
7816                 {
7817                   check_function_arguments_recurse (callback, ctx,
7818                                                     inner_arg, param_num);
7819                   found_format_arg = true;
7820                   break;
7821                 }
7822           }
7823
7824       /* If we found a format_arg attribute and did a recursive check,
7825          we are done with checking this argument.  Otherwise, we continue
7826          and this will be considered a non-literal.  */
7827       if (found_format_arg)
7828         return;
7829     }
7830
7831   if (TREE_CODE (param) == COND_EXPR)
7832     {
7833       /* Check both halves of the conditional expression.  */
7834       check_function_arguments_recurse (callback, ctx,
7835                                         TREE_OPERAND (param, 1), param_num);
7836       check_function_arguments_recurse (callback, ctx,
7837                                         TREE_OPERAND (param, 2), param_num);
7838       return;
7839     }
7840
7841   (*callback) (ctx, param, param_num);
7842 }
7843
7844 /* Checks the number of arguments NARGS against the required number
7845    REQUIRED and issues an error if there is a mismatch.  Returns true
7846    if the number of arguments is correct, otherwise false.  */
7847
7848 static bool
7849 validate_nargs (tree fndecl, int nargs, int required)
7850 {
7851   if (nargs < required)
7852     {
7853       error ("not enough arguments to function %qE", fndecl);
7854       return false;
7855     }
7856   else if (nargs > required)
7857     {
7858       error ("too many arguments to function %qE", fndecl);
7859       return false;
7860     }
7861   return true;
7862 }
7863
7864 /* Verifies the NARGS arguments ARGS to the builtin function FNDECL.
7865    Returns false if there was an error, otherwise true.  */
7866
7867 bool
7868 check_builtin_function_arguments (tree fndecl, int nargs, tree *args)
7869 {
7870   if (!DECL_BUILT_IN (fndecl)
7871       || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL)
7872     return true;
7873
7874   switch (DECL_FUNCTION_CODE (fndecl))
7875     {
7876     case BUILT_IN_CONSTANT_P:
7877       return validate_nargs (fndecl, nargs, 1);
7878
7879     case BUILT_IN_ISFINITE:
7880     case BUILT_IN_ISINF:
7881     case BUILT_IN_ISINF_SIGN:
7882     case BUILT_IN_ISNAN:
7883     case BUILT_IN_ISNORMAL:
7884       if (validate_nargs (fndecl, nargs, 1))
7885         {
7886           if (TREE_CODE (TREE_TYPE (args[0])) != REAL_TYPE)
7887             {
7888               error ("non-floating-point argument in call to "
7889                      "function %qE", fndecl);
7890               return false;
7891             }
7892           return true;
7893         }
7894       return false;
7895
7896     case BUILT_IN_ISGREATER:
7897     case BUILT_IN_ISGREATEREQUAL:
7898     case BUILT_IN_ISLESS:
7899     case BUILT_IN_ISLESSEQUAL:
7900     case BUILT_IN_ISLESSGREATER:
7901     case BUILT_IN_ISUNORDERED:
7902       if (validate_nargs (fndecl, nargs, 2))
7903         {
7904           enum tree_code code0, code1;
7905           code0 = TREE_CODE (TREE_TYPE (args[0]));
7906           code1 = TREE_CODE (TREE_TYPE (args[1]));
7907           if (!((code0 == REAL_TYPE && code1 == REAL_TYPE)
7908                 || (code0 == REAL_TYPE && code1 == INTEGER_TYPE)
7909                 || (code0 == INTEGER_TYPE && code1 == REAL_TYPE)))
7910             {
7911               error ("non-floating-point arguments in call to "
7912                      "function %qE", fndecl);
7913               return false;
7914             }
7915           return true;
7916         }
7917       return false;
7918
7919     case BUILT_IN_FPCLASSIFY:
7920       if (validate_nargs (fndecl, nargs, 6))
7921         {
7922           unsigned i;
7923
7924           for (i=0; i<5; i++)
7925             if (TREE_CODE (args[i]) != INTEGER_CST)
7926               {
7927                 error ("non-const integer argument %u in call to function %qE",
7928                        i+1, fndecl);
7929                 return false;
7930               }
7931
7932           if (TREE_CODE (TREE_TYPE (args[5])) != REAL_TYPE)
7933             {
7934               error ("non-floating-point argument in call to function %qE",
7935                      fndecl);
7936               return false;
7937             }
7938           return true;
7939         }
7940       return false;
7941
7942     default:
7943       return true;
7944     }
7945 }
7946
7947 /* Function to help qsort sort FIELD_DECLs by name order.  */
7948
7949 int
7950 field_decl_cmp (const void *x_p, const void *y_p)
7951 {
7952   const tree *const x = (const tree *const) x_p;
7953   const tree *const y = (const tree *const) y_p;
7954
7955   if (DECL_NAME (*x) == DECL_NAME (*y))
7956     /* A nontype is "greater" than a type.  */
7957     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
7958   if (DECL_NAME (*x) == NULL_TREE)
7959     return -1;
7960   if (DECL_NAME (*y) == NULL_TREE)
7961     return 1;
7962   if (DECL_NAME (*x) < DECL_NAME (*y))
7963     return -1;
7964   return 1;
7965 }
7966
7967 static struct {
7968   gt_pointer_operator new_value;
7969   void *cookie;
7970 } resort_data;
7971
7972 /* This routine compares two fields like field_decl_cmp but using the
7973 pointer operator in resort_data.  */
7974
7975 static int
7976 resort_field_decl_cmp (const void *x_p, const void *y_p)
7977 {
7978   const tree *const x = (const tree *const) x_p;
7979   const tree *const y = (const tree *const) y_p;
7980
7981   if (DECL_NAME (*x) == DECL_NAME (*y))
7982     /* A nontype is "greater" than a type.  */
7983     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
7984   if (DECL_NAME (*x) == NULL_TREE)
7985     return -1;
7986   if (DECL_NAME (*y) == NULL_TREE)
7987     return 1;
7988   {
7989     tree d1 = DECL_NAME (*x);
7990     tree d2 = DECL_NAME (*y);
7991     resort_data.new_value (&d1, resort_data.cookie);
7992     resort_data.new_value (&d2, resort_data.cookie);
7993     if (d1 < d2)
7994       return -1;
7995   }
7996   return 1;
7997 }
7998
7999 /* Resort DECL_SORTED_FIELDS because pointers have been reordered.  */
8000
8001 void
8002 resort_sorted_fields (void *obj,
8003                       void * ARG_UNUSED (orig_obj),
8004                       gt_pointer_operator new_value,
8005                       void *cookie)
8006 {
8007   struct sorted_fields_type *sf = (struct sorted_fields_type *) obj;
8008   resort_data.new_value = new_value;
8009   resort_data.cookie = cookie;
8010   qsort (&sf->elts[0], sf->len, sizeof (tree),
8011          resort_field_decl_cmp);
8012 }
8013
8014 /* Subroutine of c_parse_error.
8015    Return the result of concatenating LHS and RHS. RHS is really
8016    a string literal, its first character is indicated by RHS_START and
8017    RHS_SIZE is its length (including the terminating NUL character).
8018
8019    The caller is responsible for deleting the returned pointer.  */
8020
8021 static char *
8022 catenate_strings (const char *lhs, const char *rhs_start, int rhs_size)
8023 {
8024   const int lhs_size = strlen (lhs);
8025   char *result = XNEWVEC (char, lhs_size + rhs_size);
8026   strncpy (result, lhs, lhs_size);
8027   strncpy (result + lhs_size, rhs_start, rhs_size);
8028   return result;
8029 }
8030
8031 /* Issue the error given by GMSGID, indicating that it occurred before
8032    TOKEN, which had the associated VALUE.  */
8033
8034 void
8035 c_parse_error (const char *gmsgid, enum cpp_ttype token_type,
8036                tree value, unsigned char token_flags)
8037 {
8038 #define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2))
8039
8040   char *message = NULL;
8041
8042   if (token_type == CPP_EOF)
8043     message = catenate_messages (gmsgid, " at end of input");
8044   else if (token_type == CPP_CHAR
8045            || token_type == CPP_WCHAR
8046            || token_type == CPP_CHAR16
8047            || token_type == CPP_CHAR32)
8048     {
8049       unsigned int val = TREE_INT_CST_LOW (value);
8050       const char *prefix;
8051
8052       switch (token_type)
8053         {
8054         default:
8055           prefix = "";
8056           break;
8057         case CPP_WCHAR:
8058           prefix = "L";
8059           break;
8060         case CPP_CHAR16:
8061           prefix = "u";
8062           break;
8063         case CPP_CHAR32:
8064           prefix = "U";
8065           break;
8066         }
8067
8068       if (val <= UCHAR_MAX && ISGRAPH (val))
8069         message = catenate_messages (gmsgid, " before %s'%c'");
8070       else
8071         message = catenate_messages (gmsgid, " before %s'\\x%x'");
8072
8073       error (message, prefix, val);
8074       free (message);
8075       message = NULL;
8076     }
8077   else if (token_type == CPP_STRING
8078            || token_type == CPP_WSTRING
8079            || token_type == CPP_STRING16
8080            || token_type == CPP_STRING32)
8081     message = catenate_messages (gmsgid, " before string constant");
8082   else if (token_type == CPP_NUMBER)
8083     message = catenate_messages (gmsgid, " before numeric constant");
8084   else if (token_type == CPP_NAME)
8085     {
8086       message = catenate_messages (gmsgid, " before %qE");
8087       error (message, value);
8088       free (message);
8089       message = NULL;
8090     }
8091   else if (token_type == CPP_PRAGMA)
8092     message = catenate_messages (gmsgid, " before %<#pragma%>");
8093   else if (token_type == CPP_PRAGMA_EOL)
8094     message = catenate_messages (gmsgid, " before end of line");
8095   else if (token_type < N_TTYPES)
8096     {
8097       message = catenate_messages (gmsgid, " before %qs token");
8098       error (message, cpp_type2name (token_type, token_flags));
8099       free (message);
8100       message = NULL;
8101     }
8102   else
8103     error (gmsgid);
8104
8105   if (message)
8106     {
8107       error (message);
8108       free (message);
8109     }
8110 #undef catenate_messages
8111 }
8112
8113 /* Callback from cpp_error for PFILE to print diagnostics from the
8114    preprocessor.  The diagnostic is of type LEVEL, at location
8115    LOCATION unless this is after lexing and the compiler's location
8116    should be used instead, with column number possibly overridden by
8117    COLUMN_OVERRIDE if not zero; MSG is the translated message and AP
8118    the arguments.  Returns true if a diagnostic was emitted, false
8119    otherwise.  */
8120
8121 bool
8122 c_cpp_error (cpp_reader *pfile ATTRIBUTE_UNUSED, int level,
8123              location_t location, unsigned int column_override,
8124              const char *msg, va_list *ap)
8125 {
8126   diagnostic_info diagnostic;
8127   diagnostic_t dlevel;
8128   int save_warn_system_headers = warn_system_headers;
8129   bool ret;
8130
8131   switch (level)
8132     {
8133     case CPP_DL_WARNING_SYSHDR:
8134       if (flag_no_output)
8135         return false;
8136       warn_system_headers = 1;
8137       /* Fall through.  */
8138     case CPP_DL_WARNING:
8139       if (flag_no_output)
8140         return false;
8141       dlevel = DK_WARNING;
8142       break;
8143     case CPP_DL_PEDWARN:
8144       if (flag_no_output && !flag_pedantic_errors)
8145         return false;
8146       dlevel = DK_PEDWARN;
8147       break;
8148     case CPP_DL_ERROR:
8149       dlevel = DK_ERROR;
8150       break;
8151     case CPP_DL_ICE:
8152       dlevel = DK_ICE;
8153       break;
8154     case CPP_DL_NOTE:
8155       dlevel = DK_NOTE;
8156       break;
8157     case CPP_DL_FATAL:
8158       dlevel = DK_FATAL;
8159       break;
8160     default:
8161       gcc_unreachable ();
8162     }
8163   if (done_lexing)
8164     location = input_location;
8165   diagnostic_set_info_translated (&diagnostic, msg, ap,
8166                                   location, dlevel);
8167   if (column_override)
8168     diagnostic_override_column (&diagnostic, column_override);
8169   ret = report_diagnostic (&diagnostic);
8170   if (level == CPP_DL_WARNING_SYSHDR)
8171     warn_system_headers = save_warn_system_headers;
8172   return ret;
8173 }
8174
8175 /* Walk a gimplified function and warn for functions whose return value is
8176    ignored and attribute((warn_unused_result)) is set.  This is done before
8177    inlining, so we don't have to worry about that.  */
8178
8179 void
8180 c_warn_unused_result (gimple_seq seq)
8181 {
8182   tree fdecl, ftype;
8183   gimple_stmt_iterator i;
8184
8185   for (i = gsi_start (seq); !gsi_end_p (i); gsi_next (&i))
8186     {
8187       gimple g = gsi_stmt (i);
8188
8189       switch (gimple_code (g))
8190         {
8191         case GIMPLE_BIND:
8192           c_warn_unused_result (gimple_bind_body (g));
8193           break;
8194         case GIMPLE_TRY:
8195           c_warn_unused_result (gimple_try_eval (g));
8196           c_warn_unused_result (gimple_try_cleanup (g));
8197           break;
8198         case GIMPLE_CATCH:
8199           c_warn_unused_result (gimple_catch_handler (g));
8200           break;
8201         case GIMPLE_EH_FILTER:
8202           c_warn_unused_result (gimple_eh_filter_failure (g));
8203           break;
8204
8205         case GIMPLE_CALL:
8206           if (gimple_call_lhs (g))
8207             break;
8208
8209           /* This is a naked call, as opposed to a GIMPLE_CALL with an
8210              LHS.  All calls whose value is ignored should be
8211              represented like this.  Look for the attribute.  */
8212           fdecl = gimple_call_fndecl (g);
8213           ftype = TREE_TYPE (TREE_TYPE (gimple_call_fn (g)));
8214
8215           if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype)))
8216             {
8217               location_t loc = gimple_location (g);
8218
8219               if (fdecl)
8220                 warning (0, "%Hignoring return value of %qD, "
8221                          "declared with attribute warn_unused_result",
8222                          &loc, fdecl);
8223               else
8224                 warning (0, "%Hignoring return value of function "
8225                          "declared with attribute warn_unused_result",
8226                          &loc);
8227             }
8228           break;
8229
8230         default:
8231           /* Not a container, not a call, or a call whose value is used.  */
8232           break;
8233         }
8234     }
8235 }
8236
8237 /* Convert a character from the host to the target execution character
8238    set.  cpplib handles this, mostly.  */
8239
8240 HOST_WIDE_INT
8241 c_common_to_target_charset (HOST_WIDE_INT c)
8242 {
8243   /* Character constants in GCC proper are sign-extended under -fsigned-char,
8244      zero-extended under -fno-signed-char.  cpplib insists that characters
8245      and character constants are always unsigned.  Hence we must convert
8246      back and forth.  */
8247   cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1);
8248
8249   uc = cpp_host_to_exec_charset (parse_in, uc);
8250
8251   if (flag_signed_char)
8252     return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE)
8253                                >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE);
8254   else
8255     return uc;
8256 }
8257
8258 /* Build the result of __builtin_offsetof.  EXPR is a nested sequence of
8259    component references, with STOP_REF, or alternatively an INDIRECT_REF of
8260    NULL, at the bottom; much like the traditional rendering of offsetof as a
8261    macro.  Returns the folded and properly cast result.  */
8262
8263 static tree
8264 fold_offsetof_1 (tree expr, tree stop_ref)
8265 {
8266   enum tree_code code = PLUS_EXPR;
8267   tree base, off, t;
8268
8269   if (expr == stop_ref && TREE_CODE (expr) != ERROR_MARK)
8270     return size_zero_node;
8271
8272   switch (TREE_CODE (expr))
8273     {
8274     case ERROR_MARK:
8275       return expr;
8276
8277     case VAR_DECL:
8278       error ("cannot apply %<offsetof%> to static data member %qD", expr);
8279       return error_mark_node;
8280
8281     case CALL_EXPR:
8282     case TARGET_EXPR:
8283       error ("cannot apply %<offsetof%> when %<operator[]%> is overloaded");
8284       return error_mark_node;
8285
8286     case INTEGER_CST:
8287       gcc_assert (integer_zerop (expr));
8288       return size_zero_node;
8289
8290     case NOP_EXPR:
8291     case INDIRECT_REF:
8292       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
8293       gcc_assert (base == error_mark_node || base == size_zero_node);
8294       return base;
8295
8296     case COMPONENT_REF:
8297       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
8298       if (base == error_mark_node)
8299         return base;
8300
8301       t = TREE_OPERAND (expr, 1);
8302       if (DECL_C_BIT_FIELD (t))
8303         {
8304           error ("attempt to take address of bit-field structure "
8305                  "member %qD", t);
8306           return error_mark_node;
8307         }
8308       off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t),
8309                         size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t), 1)
8310                                   / BITS_PER_UNIT));
8311       break;
8312
8313     case ARRAY_REF:
8314       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
8315       if (base == error_mark_node)
8316         return base;
8317
8318       t = TREE_OPERAND (expr, 1);
8319       if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0)
8320         {
8321           code = MINUS_EXPR;
8322           t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t);
8323         }
8324       t = convert (sizetype, t);
8325       off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
8326       break;
8327
8328     case COMPOUND_EXPR:
8329       /* Handle static members of volatile structs.  */
8330       t = TREE_OPERAND (expr, 1);
8331       gcc_assert (TREE_CODE (t) == VAR_DECL);
8332       return fold_offsetof_1 (t, stop_ref);
8333
8334     default:
8335       gcc_unreachable ();
8336     }
8337
8338   return size_binop (code, base, off);
8339 }
8340
8341 tree
8342 fold_offsetof (tree expr, tree stop_ref)
8343 {
8344   /* Convert back from the internal sizetype to size_t.  */
8345   return convert (size_type_node, fold_offsetof_1 (expr, stop_ref));
8346 }
8347
8348 /* Print an error message for an invalid lvalue.  USE says
8349    how the lvalue is being used and so selects the error message.  */
8350
8351 void
8352 lvalue_error (enum lvalue_use use)
8353 {
8354   switch (use)
8355     {
8356     case lv_assign:
8357       error ("lvalue required as left operand of assignment");
8358       break;
8359     case lv_increment:
8360       error ("lvalue required as increment operand");
8361       break;
8362     case lv_decrement:
8363       error ("lvalue required as decrement operand");
8364       break;
8365     case lv_addressof:
8366       error ("lvalue required as unary %<&%> operand");
8367       break;
8368     case lv_asm:
8369       error ("lvalue required in asm statement");
8370       break;
8371     default:
8372       gcc_unreachable ();
8373     }
8374 }
8375 \f
8376 /* *PTYPE is an incomplete array.  Complete it with a domain based on
8377    INITIAL_VALUE.  If INITIAL_VALUE is not present, use 1 if DO_DEFAULT
8378    is true.  Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered,
8379    2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty.  */
8380
8381 int
8382 complete_array_type (tree *ptype, tree initial_value, bool do_default)
8383 {
8384   tree maxindex, type, main_type, elt, unqual_elt;
8385   int failure = 0, quals;
8386   hashval_t hashcode = 0;
8387
8388   maxindex = size_zero_node;
8389   if (initial_value)
8390     {
8391       if (TREE_CODE (initial_value) == STRING_CST)
8392         {
8393           int eltsize
8394             = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value)));
8395           maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1);
8396         }
8397       else if (TREE_CODE (initial_value) == CONSTRUCTOR)
8398         {
8399           VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (initial_value);
8400
8401           if (VEC_empty (constructor_elt, v))
8402             {
8403               if (pedantic)
8404                 failure = 3;
8405               maxindex = integer_minus_one_node;
8406             }
8407           else
8408             {
8409               tree curindex;
8410               unsigned HOST_WIDE_INT cnt;
8411               constructor_elt *ce;
8412               bool fold_p = false;
8413
8414               if (VEC_index (constructor_elt, v, 0)->index)
8415                 maxindex = fold_convert (sizetype,
8416                                          VEC_index (constructor_elt,
8417                                                     v, 0)->index);
8418               curindex = maxindex;
8419
8420               for (cnt = 1;
8421                    VEC_iterate (constructor_elt, v, cnt, ce);
8422                    cnt++)
8423                 {
8424                   bool curfold_p = false;
8425                   if (ce->index)
8426                     curindex = ce->index, curfold_p = true;
8427                   else
8428                     {
8429                       if (fold_p)
8430                         curindex = fold_convert (sizetype, curindex);
8431                       curindex = size_binop (PLUS_EXPR, curindex, size_one_node);
8432                     }
8433                   if (tree_int_cst_lt (maxindex, curindex))
8434                     maxindex = curindex, fold_p = curfold_p;
8435                 }
8436                if (fold_p)
8437                  maxindex = fold_convert (sizetype, maxindex);
8438             }
8439         }
8440       else
8441         {
8442           /* Make an error message unless that happened already.  */
8443           if (initial_value != error_mark_node)
8444             failure = 1;
8445         }
8446     }
8447   else
8448     {
8449       failure = 2;
8450       if (!do_default)
8451         return failure;
8452     }
8453
8454   type = *ptype;
8455   elt = TREE_TYPE (type);
8456   quals = TYPE_QUALS (strip_array_types (elt));
8457   if (quals == 0)
8458     unqual_elt = elt;
8459   else
8460     unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
8461
8462   /* Using build_distinct_type_copy and modifying things afterward instead
8463      of using build_array_type to create a new type preserves all of the
8464      TYPE_LANG_FLAG_? bits that the front end may have set.  */
8465   main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
8466   TREE_TYPE (main_type) = unqual_elt;
8467   TYPE_DOMAIN (main_type) = build_index_type (maxindex);
8468   layout_type (main_type);
8469
8470   /* Make sure we have the canonical MAIN_TYPE. */
8471   hashcode = iterative_hash_object (TYPE_HASH (unqual_elt), hashcode);
8472   hashcode = iterative_hash_object (TYPE_HASH (TYPE_DOMAIN (main_type)),
8473                                     hashcode);
8474   main_type = type_hash_canon (hashcode, main_type);
8475
8476   /* Fix the canonical type.  */
8477   if (TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (main_type))
8478       || TYPE_STRUCTURAL_EQUALITY_P (TYPE_DOMAIN (main_type)))
8479     SET_TYPE_STRUCTURAL_EQUALITY (main_type);
8480   else if (TYPE_CANONICAL (TREE_TYPE (main_type)) != TREE_TYPE (main_type)
8481            || (TYPE_CANONICAL (TYPE_DOMAIN (main_type))
8482                != TYPE_DOMAIN (main_type)))
8483     TYPE_CANONICAL (main_type)
8484       = build_array_type (TYPE_CANONICAL (TREE_TYPE (main_type)),
8485                           TYPE_CANONICAL (TYPE_DOMAIN (main_type)));
8486   else
8487     TYPE_CANONICAL (main_type) = main_type;
8488
8489   if (quals == 0)
8490     type = main_type;
8491   else
8492     type = c_build_qualified_type (main_type, quals);
8493
8494   if (COMPLETE_TYPE_P (type)
8495       && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST
8496       && TREE_OVERFLOW (TYPE_SIZE_UNIT (type)))
8497     {
8498       error ("size of array is too large");
8499       /* If we proceed with the array type as it is, we'll eventually
8500          crash in tree_low_cst().  */
8501       type = error_mark_node;
8502     }
8503
8504   *ptype = type;
8505   return failure;
8506 }
8507
8508 \f
8509 /* Used to help initialize the builtin-types.def table.  When a type of
8510    the correct size doesn't exist, use error_mark_node instead of NULL.
8511    The later results in segfaults even when a decl using the type doesn't
8512    get invoked.  */
8513
8514 tree
8515 builtin_type_for_size (int size, bool unsignedp)
8516 {
8517   tree type = lang_hooks.types.type_for_size (size, unsignedp);
8518   return type ? type : error_mark_node;
8519 }
8520
8521 /* A helper function for resolve_overloaded_builtin in resolving the
8522    overloaded __sync_ builtins.  Returns a positive power of 2 if the
8523    first operand of PARAMS is a pointer to a supported data type.
8524    Returns 0 if an error is encountered.  */
8525
8526 static int
8527 sync_resolve_size (tree function, VEC(tree,gc) *params)
8528 {
8529   tree type;
8530   int size;
8531
8532   if (VEC_empty (tree, params))
8533     {
8534       error ("too few arguments to function %qE", function);
8535       return 0;
8536     }
8537
8538   type = TREE_TYPE (VEC_index (tree, params, 0));
8539   if (TREE_CODE (type) != POINTER_TYPE)
8540     goto incompatible;
8541
8542   type = TREE_TYPE (type);
8543   if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
8544     goto incompatible;
8545
8546   size = tree_low_cst (TYPE_SIZE_UNIT (type), 1);
8547   if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16)
8548     return size;
8549
8550  incompatible:
8551   error ("incompatible type for argument %d of %qE", 1, function);
8552   return 0;
8553 }
8554
8555 /* A helper function for resolve_overloaded_builtin.  Adds casts to
8556    PARAMS to make arguments match up with those of FUNCTION.  Drops
8557    the variadic arguments at the end.  Returns false if some error
8558    was encountered; true on success.  */
8559
8560 static bool
8561 sync_resolve_params (tree orig_function, tree function, VEC(tree, gc) *params)
8562 {
8563   tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (function));
8564   tree ptype;
8565   int number;
8566   unsigned int parmnum;
8567
8568   /* We've declared the implementation functions to use "volatile void *"
8569      as the pointer parameter, so we shouldn't get any complaints from the
8570      call to check_function_arguments what ever type the user used.  */
8571   arg_types = TREE_CHAIN (arg_types);
8572   ptype = TREE_TYPE (TREE_TYPE (VEC_index (tree, params, 0)));
8573   number = 2;
8574
8575   /* For the rest of the values, we need to cast these to FTYPE, so that we
8576      don't get warnings for passing pointer types, etc.  */
8577   parmnum = 0;
8578   while (arg_types != void_list_node)
8579     {
8580       tree val;
8581
8582       ++parmnum;
8583       if (VEC_length (tree, params) <= parmnum)
8584         {
8585           error ("too few arguments to function %qE", orig_function);
8586           return false;
8587         }
8588
8589       /* ??? Ideally for the first conversion we'd use convert_for_assignment
8590          so that we get warnings for anything that doesn't match the pointer
8591          type.  This isn't portable across the C and C++ front ends atm.  */
8592       val = VEC_index (tree, params, parmnum);
8593       val = convert (ptype, val);
8594       val = convert (TREE_VALUE (arg_types), val);
8595       VEC_replace (tree, params, parmnum, val);
8596
8597       arg_types = TREE_CHAIN (arg_types);
8598       number++;
8599     }
8600
8601   /* The definition of these primitives is variadic, with the remaining
8602      being "an optional list of variables protected by the memory barrier".
8603      No clue what that's supposed to mean, precisely, but we consider all
8604      call-clobbered variables to be protected so we're safe.  */
8605   VEC_truncate (tree, params, parmnum + 1);
8606
8607   return true;
8608 }
8609
8610 /* A helper function for resolve_overloaded_builtin.  Adds a cast to
8611    RESULT to make it match the type of the first pointer argument in
8612    PARAMS.  */
8613
8614 static tree
8615 sync_resolve_return (tree first_param, tree result)
8616 {
8617   tree ptype = TREE_TYPE (TREE_TYPE (first_param));
8618   ptype = TYPE_MAIN_VARIANT (ptype);
8619   return convert (ptype, result);
8620 }
8621
8622 /* Some builtin functions are placeholders for other expressions.  This
8623    function should be called immediately after parsing the call expression
8624    before surrounding code has committed to the type of the expression.
8625
8626    FUNCTION is the DECL that has been invoked; it is known to be a builtin.
8627    PARAMS is the argument list for the call.  The return value is non-null
8628    when expansion is complete, and null if normal processing should
8629    continue.  */
8630
8631 tree
8632 resolve_overloaded_builtin (tree function, VEC(tree,gc) *params)
8633 {
8634   enum built_in_function orig_code = DECL_FUNCTION_CODE (function);
8635   switch (DECL_BUILT_IN_CLASS (function))
8636     {
8637     case BUILT_IN_NORMAL:
8638       break;
8639     case BUILT_IN_MD:
8640       if (targetm.resolve_overloaded_builtin)
8641         return targetm.resolve_overloaded_builtin (function, params);
8642       else
8643         return NULL_TREE;
8644     default:
8645       return NULL_TREE;
8646     }
8647
8648   /* Handle BUILT_IN_NORMAL here.  */
8649   switch (orig_code)
8650     {
8651     case BUILT_IN_FETCH_AND_ADD_N:
8652     case BUILT_IN_FETCH_AND_SUB_N:
8653     case BUILT_IN_FETCH_AND_OR_N:
8654     case BUILT_IN_FETCH_AND_AND_N:
8655     case BUILT_IN_FETCH_AND_XOR_N:
8656     case BUILT_IN_FETCH_AND_NAND_N:
8657     case BUILT_IN_ADD_AND_FETCH_N:
8658     case BUILT_IN_SUB_AND_FETCH_N:
8659     case BUILT_IN_OR_AND_FETCH_N:
8660     case BUILT_IN_AND_AND_FETCH_N:
8661     case BUILT_IN_XOR_AND_FETCH_N:
8662     case BUILT_IN_NAND_AND_FETCH_N:
8663     case BUILT_IN_BOOL_COMPARE_AND_SWAP_N:
8664     case BUILT_IN_VAL_COMPARE_AND_SWAP_N:
8665     case BUILT_IN_LOCK_TEST_AND_SET_N:
8666     case BUILT_IN_LOCK_RELEASE_N:
8667       {
8668         int n = sync_resolve_size (function, params);
8669         tree new_function, first_param, result;
8670
8671         if (n == 0)
8672           return error_mark_node;
8673
8674         new_function = built_in_decls[orig_code + exact_log2 (n) + 1];
8675         if (!sync_resolve_params (function, new_function, params))
8676           return error_mark_node;
8677
8678         first_param = VEC_index (tree, params, 0);
8679         result = build_function_call_vec (new_function, params, NULL);
8680         if (orig_code != BUILT_IN_BOOL_COMPARE_AND_SWAP_N
8681             && orig_code != BUILT_IN_LOCK_RELEASE_N)
8682           result = sync_resolve_return (first_param, result);
8683
8684         return result;
8685       }
8686
8687     default:
8688       return NULL_TREE;
8689     }
8690 }
8691
8692 /* Ignoring their sign, return true if two scalar types are the same.  */
8693 bool
8694 same_scalar_type_ignoring_signedness (tree t1, tree t2)
8695 {
8696   enum tree_code c1 = TREE_CODE (t1), c2 = TREE_CODE (t2);
8697
8698   gcc_assert ((c1 == INTEGER_TYPE || c1 == REAL_TYPE || c1 == FIXED_POINT_TYPE)
8699               && (c2 == INTEGER_TYPE || c2 == REAL_TYPE
8700                   || c2 == FIXED_POINT_TYPE));
8701
8702   /* Equality works here because c_common_signed_type uses
8703      TYPE_MAIN_VARIANT.  */
8704   return c_common_signed_type (t1)
8705     == c_common_signed_type (t2);
8706 }
8707
8708 /* Check for missing format attributes on function pointers.  LTYPE is
8709    the new type or left-hand side type.  RTYPE is the old type or
8710    right-hand side type.  Returns TRUE if LTYPE is missing the desired
8711    attribute.  */
8712
8713 bool
8714 check_missing_format_attribute (tree ltype, tree rtype)
8715 {
8716   tree const ttr = TREE_TYPE (rtype), ttl = TREE_TYPE (ltype);
8717   tree ra;
8718
8719   for (ra = TYPE_ATTRIBUTES (ttr); ra; ra = TREE_CHAIN (ra))
8720     if (is_attribute_p ("format", TREE_PURPOSE (ra)))
8721       break;
8722   if (ra)
8723     {
8724       tree la;
8725       for (la = TYPE_ATTRIBUTES (ttl); la; la = TREE_CHAIN (la))
8726         if (is_attribute_p ("format", TREE_PURPOSE (la)))
8727           break;
8728       return !la;
8729     }
8730   else
8731     return false;
8732 }
8733
8734 /* Subscripting with type char is likely to lose on a machine where
8735    chars are signed.  So warn on any machine, but optionally.  Don't
8736    warn for unsigned char since that type is safe.  Don't warn for
8737    signed char because anyone who uses that must have done so
8738    deliberately. Furthermore, we reduce the false positive load by
8739    warning only for non-constant value of type char.  */
8740
8741 void
8742 warn_array_subscript_with_type_char (tree index)
8743 {
8744   if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node
8745       && TREE_CODE (index) != INTEGER_CST)
8746     warning (OPT_Wchar_subscripts, "array subscript has type %<char%>");
8747 }
8748
8749 /* Implement -Wparentheses for the unexpected C precedence rules, to
8750    cover cases like x + y << z which readers are likely to
8751    misinterpret.  We have seen an expression in which CODE is a binary
8752    operator used to combine expressions ARG_LEFT and ARG_RIGHT, which
8753    before folding had CODE_LEFT and CODE_RIGHT.  CODE_LEFT and
8754    CODE_RIGHT may be ERROR_MARK, which means that that side of the
8755    expression was not formed using a binary or unary operator, or it
8756    was enclosed in parentheses.  */
8757
8758 void
8759 warn_about_parentheses (enum tree_code code,
8760                         enum tree_code code_left, tree arg_left,
8761                         enum tree_code code_right, tree arg_right)
8762 {
8763   if (!warn_parentheses)
8764     return;
8765
8766   /* This macro tests that the expression ARG with original tree code
8767      CODE appears to be a boolean expression. or the result of folding a
8768      boolean expression.  */
8769 #define APPEARS_TO_BE_BOOLEAN_EXPR_P(CODE, ARG)                             \
8770         (truth_value_p (TREE_CODE (ARG))                                    \
8771          || TREE_CODE (TREE_TYPE (ARG)) == BOOLEAN_TYPE                     \
8772          /* Folding may create 0 or 1 integers from other expressions.  */  \
8773          || ((CODE) != INTEGER_CST                                          \
8774              && (integer_onep (ARG) || integer_zerop (ARG))))
8775
8776   switch (code)
8777     {
8778     case LSHIFT_EXPR:
8779       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8780         warning (OPT_Wparentheses,
8781                  "suggest parentheses around %<+%> inside %<<<%>");
8782       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8783         warning (OPT_Wparentheses,
8784                  "suggest parentheses around %<-%> inside %<<<%>");
8785       return;
8786
8787     case RSHIFT_EXPR:
8788       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8789         warning (OPT_Wparentheses,
8790                  "suggest parentheses around %<+%> inside %<>>%>");
8791       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8792         warning (OPT_Wparentheses,
8793                  "suggest parentheses around %<-%> inside %<>>%>");
8794       return;
8795
8796     case TRUTH_ORIF_EXPR:
8797       if (code_left == TRUTH_ANDIF_EXPR || code_right == TRUTH_ANDIF_EXPR)
8798         warning (OPT_Wparentheses,
8799                  "suggest parentheses around %<&&%> within %<||%>");
8800       return;
8801
8802     case BIT_IOR_EXPR:
8803       if (code_left == BIT_AND_EXPR || code_left == BIT_XOR_EXPR
8804           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
8805           || code_right == BIT_AND_EXPR || code_right == BIT_XOR_EXPR
8806           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
8807         warning (OPT_Wparentheses,
8808                  "suggest parentheses around arithmetic in operand of %<|%>");
8809       /* Check cases like x|y==z */
8810       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8811                || TREE_CODE_CLASS (code_right) == tcc_comparison)
8812         warning (OPT_Wparentheses,
8813                  "suggest parentheses around comparison in operand of %<|%>");
8814       /* Check cases like !x | y */
8815       else if (code_left == TRUTH_NOT_EXPR
8816                && !APPEARS_TO_BE_BOOLEAN_EXPR_P (code_right, arg_right))
8817         warning (OPT_Wparentheses, "suggest parentheses around operand of "
8818                  "%<!%> or change %<|%> to %<||%> or %<!%> to %<~%>");
8819       return;
8820
8821     case BIT_XOR_EXPR:
8822       if (code_left == BIT_AND_EXPR
8823           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
8824           || code_right == BIT_AND_EXPR
8825           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
8826         warning (OPT_Wparentheses,
8827                  "suggest parentheses around arithmetic in operand of %<^%>");
8828       /* Check cases like x^y==z */
8829       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8830                || TREE_CODE_CLASS (code_right) == tcc_comparison)
8831         warning (OPT_Wparentheses,
8832                  "suggest parentheses around comparison in operand of %<^%>");
8833       return;
8834
8835     case BIT_AND_EXPR:
8836       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8837         warning (OPT_Wparentheses,
8838                  "suggest parentheses around %<+%> in operand of %<&%>");
8839       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8840         warning (OPT_Wparentheses,
8841                  "suggest parentheses around %<-%> in operand of %<&%>");
8842       /* Check cases like x&y==z */
8843       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8844                || TREE_CODE_CLASS (code_right) == tcc_comparison)
8845         warning (OPT_Wparentheses,
8846                  "suggest parentheses around comparison in operand of %<&%>");
8847       /* Check cases like !x & y */
8848       else if (code_left == TRUTH_NOT_EXPR
8849                && !APPEARS_TO_BE_BOOLEAN_EXPR_P (code_right, arg_right))
8850         warning (OPT_Wparentheses, "suggest parentheses around operand of "
8851                  "%<!%> or change %<&%> to %<&&%> or %<!%> to %<~%>");
8852       return;
8853
8854     case EQ_EXPR:
8855       if (TREE_CODE_CLASS (code_left) == tcc_comparison
8856           || TREE_CODE_CLASS (code_right) == tcc_comparison)
8857         warning (OPT_Wparentheses,
8858                  "suggest parentheses around comparison in operand of %<==%>");
8859       return;
8860     case NE_EXPR:
8861       if (TREE_CODE_CLASS (code_left) == tcc_comparison
8862           || TREE_CODE_CLASS (code_right) == tcc_comparison)
8863         warning (OPT_Wparentheses,
8864                  "suggest parentheses around comparison in operand of %<!=%>");
8865       return;
8866
8867     default:
8868       if (TREE_CODE_CLASS (code) == tcc_comparison
8869            && ((TREE_CODE_CLASS (code_left) == tcc_comparison
8870                 && code_left != NE_EXPR && code_left != EQ_EXPR
8871                 && INTEGRAL_TYPE_P (TREE_TYPE (arg_left)))
8872                || (TREE_CODE_CLASS (code_right) == tcc_comparison
8873                    && code_right != NE_EXPR && code_right != EQ_EXPR
8874                    && INTEGRAL_TYPE_P (TREE_TYPE (arg_right)))))
8875         warning (OPT_Wparentheses, "comparisons like %<X<=Y<=Z%> do not "
8876                  "have their mathematical meaning");
8877       return;
8878     }
8879 #undef NOT_A_BOOLEAN_EXPR_P
8880 }
8881
8882 /* If LABEL (a LABEL_DECL) has not been used, issue a warning.  */
8883
8884 void
8885 warn_for_unused_label (tree label)
8886 {
8887   if (!TREE_USED (label))
8888     {
8889       if (DECL_INITIAL (label))
8890         warning (OPT_Wunused_label, "label %q+D defined but not used", label);
8891       else
8892         warning (OPT_Wunused_label, "label %q+D declared but not defined", label);
8893     }
8894 }
8895
8896 #ifndef TARGET_HAS_TARGETCM
8897 struct gcc_targetcm targetcm = TARGETCM_INITIALIZER;
8898 #endif
8899
8900 /* Warn for division by zero according to the value of DIVISOR.  LOC
8901    is the location of the division operator.  */
8902
8903 void
8904 warn_for_div_by_zero (location_t loc, tree divisor)
8905 {
8906   /* If DIVISOR is zero, and has integral or fixed-point type, issue a warning
8907      about division by zero.  Do not issue a warning if DIVISOR has a
8908      floating-point type, since we consider 0.0/0.0 a valid way of
8909      generating a NaN.  */
8910   if (skip_evaluation == 0
8911       && (integer_zerop (divisor) || fixed_zerop (divisor)))
8912     warning_at (loc, OPT_Wdiv_by_zero, "division by zero");
8913 }
8914
8915 /* Subroutine of build_binary_op. Give warnings for comparisons
8916    between signed and unsigned quantities that may fail. Do the
8917    checking based on the original operand trees ORIG_OP0 and ORIG_OP1,
8918    so that casts will be considered, but default promotions won't
8919    be.
8920
8921    LOCATION is the location of the comparison operator.
8922
8923    The arguments of this function map directly to local variables
8924    of build_binary_op.  */
8925
8926 void
8927 warn_for_sign_compare (location_t location,
8928                        tree orig_op0, tree orig_op1,
8929                        tree op0, tree op1,
8930                        tree result_type, enum tree_code resultcode)
8931 {
8932   int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
8933   int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
8934   int unsignedp0, unsignedp1;
8935
8936   /* In C++, check for comparison of different enum types.  */
8937   if (c_dialect_cxx()
8938       && TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
8939       && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
8940       && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
8941          != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
8942     {
8943       warning_at (location,
8944                   OPT_Wsign_compare, "comparison between types %qT and %qT",
8945                   TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
8946     }
8947
8948   /* Do not warn if the comparison is being done in a signed type,
8949      since the signed type will only be chosen if it can represent
8950      all the values of the unsigned type.  */
8951   if (!TYPE_UNSIGNED (result_type))
8952     /* OK */;
8953   /* Do not warn if both operands are unsigned.  */
8954   else if (op0_signed == op1_signed)
8955     /* OK */;
8956   else
8957     {
8958       tree sop, uop, base_type;
8959       bool ovf;
8960
8961       if (op0_signed)
8962         sop = orig_op0, uop = orig_op1;
8963       else
8964         sop = orig_op1, uop = orig_op0;
8965
8966       STRIP_TYPE_NOPS (sop);
8967       STRIP_TYPE_NOPS (uop);
8968       base_type = (TREE_CODE (result_type) == COMPLEX_TYPE
8969                    ? TREE_TYPE (result_type) : result_type);
8970
8971       /* Do not warn if the signed quantity is an unsuffixed integer
8972          literal (or some static constant expression involving such
8973          literals or a conditional expression involving such literals)
8974          and it is non-negative.  */
8975       if (tree_expr_nonnegative_warnv_p (sop, &ovf))
8976         /* OK */;
8977       /* Do not warn if the comparison is an equality operation, the
8978          unsigned quantity is an integral constant, and it would fit
8979          in the result if the result were signed.  */
8980       else if (TREE_CODE (uop) == INTEGER_CST
8981                && (resultcode == EQ_EXPR || resultcode == NE_EXPR)
8982                && int_fits_type_p (uop, c_common_signed_type (base_type)))
8983         /* OK */;
8984       /* In C, do not warn if the unsigned quantity is an enumeration
8985          constant and its maximum value would fit in the result if the
8986          result were signed.  */
8987       else if (!c_dialect_cxx() && TREE_CODE (uop) == INTEGER_CST
8988                && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE
8989                && int_fits_type_p (TYPE_MAX_VALUE (TREE_TYPE (uop)),
8990                                    c_common_signed_type (base_type)))
8991         /* OK */;
8992       else
8993         warning_at (location,
8994                     OPT_Wsign_compare,
8995                     "comparison between signed and unsigned integer expressions");
8996     }
8997
8998   /* Warn if two unsigned values are being compared in a size larger
8999      than their original size, and one (and only one) is the result of
9000      a `~' operator.  This comparison will always fail.
9001
9002      Also warn if one operand is a constant, and the constant does not
9003      have all bits set that are set in the ~ operand when it is
9004      extended.  */
9005
9006   op0 = get_narrower (op0, &unsignedp0);
9007   op1 = get_narrower (op1, &unsignedp1);
9008
9009   if ((TREE_CODE (op0) == BIT_NOT_EXPR)
9010       ^ (TREE_CODE (op1) == BIT_NOT_EXPR))
9011     {
9012       if (TREE_CODE (op0) == BIT_NOT_EXPR)
9013         op0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
9014       if (TREE_CODE (op1) == BIT_NOT_EXPR)
9015         op1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
9016
9017       if (host_integerp (op0, 0) || host_integerp (op1, 0))
9018         {
9019           tree primop;
9020           HOST_WIDE_INT constant, mask;
9021           int unsignedp;
9022           unsigned int bits;
9023
9024           if (host_integerp (op0, 0))
9025             {
9026               primop = op1;
9027               unsignedp = unsignedp1;
9028               constant = tree_low_cst (op0, 0);
9029             }
9030           else
9031             {
9032               primop = op0;
9033               unsignedp = unsignedp0;
9034               constant = tree_low_cst (op1, 0);
9035             }
9036
9037           bits = TYPE_PRECISION (TREE_TYPE (primop));
9038           if (bits < TYPE_PRECISION (result_type)
9039               && bits < HOST_BITS_PER_LONG && unsignedp)
9040             {
9041               mask = (~ (HOST_WIDE_INT) 0) << bits;
9042               if ((mask & constant) != mask)
9043                 {
9044                   if (constant == 0)
9045                     warning (OPT_Wsign_compare,
9046                              "promoted ~unsigned is always non-zero");
9047                   else
9048                     warning_at (location, OPT_Wsign_compare,
9049                                 "comparison of promoted ~unsigned with constant");
9050                 }
9051             }
9052         }
9053       else if (unsignedp0 && unsignedp1
9054                && (TYPE_PRECISION (TREE_TYPE (op0))
9055                    < TYPE_PRECISION (result_type))
9056                && (TYPE_PRECISION (TREE_TYPE (op1))
9057                    < TYPE_PRECISION (result_type)))
9058         warning_at (location, OPT_Wsign_compare,
9059                  "comparison of promoted ~unsigned with unsigned");
9060     }
9061 }
9062
9063 /* Setup a TYPE_DECL node as a typedef representation.
9064
9065    X is a TYPE_DECL for a typedef statement.  Create a brand new
9066    ..._TYPE node (which will be just a variant of the existing
9067    ..._TYPE node with identical properties) and then install X
9068    as the TYPE_NAME of this brand new (duplicate) ..._TYPE node.
9069
9070    The whole point here is to end up with a situation where each
9071    and every ..._TYPE node the compiler creates will be uniquely
9072    associated with AT MOST one node representing a typedef name.
9073    This way, even though the compiler substitutes corresponding
9074    ..._TYPE nodes for TYPE_DECL (i.e. "typedef name") nodes very
9075    early on, later parts of the compiler can always do the reverse
9076    translation and get back the corresponding typedef name.  For
9077    example, given:
9078
9079         typedef struct S MY_TYPE;
9080         MY_TYPE object;
9081
9082    Later parts of the compiler might only know that `object' was of
9083    type `struct S' if it were not for code just below.  With this
9084    code however, later parts of the compiler see something like:
9085
9086         struct S' == struct S
9087         typedef struct S' MY_TYPE;
9088         struct S' object;
9089
9090     And they can then deduce (from the node for type struct S') that
9091     the original object declaration was:
9092
9093                 MY_TYPE object;
9094
9095     Being able to do this is important for proper support of protoize,
9096     and also for generating precise symbolic debugging information
9097     which takes full account of the programmer's (typedef) vocabulary.
9098
9099     Obviously, we don't want to generate a duplicate ..._TYPE node if
9100     the TYPE_DECL node that we are now processing really represents a
9101     standard built-in type.  */
9102
9103 void
9104 set_underlying_type (tree x)
9105 {
9106   if (x == error_mark_node)
9107     return;
9108   if (DECL_IS_BUILTIN (x))
9109     {
9110       if (TYPE_NAME (TREE_TYPE (x)) == 0)
9111         TYPE_NAME (TREE_TYPE (x)) = x;
9112     }
9113   else if (TREE_TYPE (x) != error_mark_node
9114            && DECL_ORIGINAL_TYPE (x) == NULL_TREE)
9115     {
9116       tree tt = TREE_TYPE (x);
9117       DECL_ORIGINAL_TYPE (x) = tt;
9118       tt = build_variant_type_copy (tt);
9119       TYPE_STUB_DECL (tt) = TYPE_STUB_DECL (DECL_ORIGINAL_TYPE (x));
9120       TYPE_NAME (tt) = x;
9121       TREE_USED (tt) = TREE_USED (x);
9122       TREE_TYPE (x) = tt;
9123     }
9124 }
9125
9126 /* Returns true if X is a typedef decl.  */
9127
9128 bool
9129 is_typedef_decl (tree x)
9130 {
9131   return (x && TREE_CODE (x) == TYPE_DECL
9132           && DECL_ORIGINAL_TYPE (x) != NULL_TREE);
9133 }
9134
9135 /* The C and C++ parsers both use vectors to hold function arguments.
9136    For efficiency, we keep a cache of unused vectors.  This is the
9137    cache.  */
9138
9139 typedef VEC(tree,gc)* tree_gc_vec;
9140 DEF_VEC_P(tree_gc_vec);
9141 DEF_VEC_ALLOC_P(tree_gc_vec,gc);
9142 static GTY((deletable)) VEC(tree_gc_vec,gc) *tree_vector_cache;
9143
9144 /* Return a new vector from the cache.  If the cache is empty,
9145    allocate a new vector.  These vectors are GC'ed, so it is OK if the
9146    pointer is not released..  */
9147
9148 VEC(tree,gc) *
9149 make_tree_vector (void)
9150 {
9151   if (!VEC_empty (tree_gc_vec, tree_vector_cache))
9152     return VEC_pop (tree_gc_vec, tree_vector_cache);
9153   else
9154     {
9155       /* Passing 0 to VEC_alloc returns NULL, and our callers require
9156          that we always return a non-NULL value.  The vector code uses
9157          4 when growing a NULL vector, so we do too.  */
9158       return VEC_alloc (tree, gc, 4);
9159     }
9160 }
9161
9162 /* Release a vector of trees back to the cache.  */
9163
9164 void
9165 release_tree_vector (VEC(tree,gc) *vec)
9166 {
9167   if (vec != NULL)
9168     {
9169       VEC_truncate (tree, vec, 0);
9170       VEC_safe_push (tree_gc_vec, gc, tree_vector_cache, vec);
9171     }
9172 }
9173
9174 /* Get a new tree vector holding a single tree.  */
9175
9176 VEC(tree,gc) *
9177 make_tree_vector_single (tree t)
9178 {
9179   VEC(tree,gc) *ret = make_tree_vector ();
9180   VEC_quick_push (tree, ret, t);
9181   return ret;
9182 }
9183
9184 /* Get a new tree vector which is a copy of an existing one.  */
9185
9186 VEC(tree,gc) *
9187 make_tree_vector_copy (const VEC(tree,gc) *orig)
9188 {
9189   VEC(tree,gc) *ret;
9190   unsigned int ix;
9191   tree t;
9192
9193   ret = make_tree_vector ();
9194   VEC_reserve (tree, gc, ret, VEC_length (tree, orig));
9195   for (ix = 0; VEC_iterate (tree, orig, ix, t); ++ix)
9196     VEC_quick_push (tree, ret, t);
9197   return ret;
9198 }
9199
9200 #include "gt-c-common.h"