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 exists to limit the
 432    time it takes to notice infinite template instantiations; the default
 433    value of 1024 is likely to be in the next C++ standard.  */
 434
 435 int max_tinst_depth = 1024;
 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) (location_t, tree, int);
 444
 445 /* Nonzero means don't warn about problems that occur when the code is
 446    executed.  */
 447 int c_inhibit_evaluation_warnings;
 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_noclone_attribute (tree *, tree, tree, int, bool *);
 486 static tree handle_always_inline_attribute (tree *, tree, tree, int,
 487                                             bool *);
 488 static tree handle_gnu_inline_attribute (tree *, tree, tree, int, bool *);
 489 static tree handle_artificial_attribute (tree *, tree, tree, int, bool *);
 490 static tree handle_flatten_attribute (tree *, tree, tree, int, bool *);
 491 static tree handle_error_attribute (tree *, tree, tree, int, bool *);
 492 static tree handle_used_attribute (tree *, tree, tree, int, bool *);
 493 static tree handle_unused_attribute (tree *, tree, tree, int, bool *);
 494 static tree handle_externally_visible_attribute (tree *, tree, tree, int,
 495                                                  bool *);
 496 static tree handle_const_attribute (tree *, tree, tree, int, bool *);
 497 static tree handle_transparent_union_attribute (tree *, tree, tree,
 498                                                 int, bool *);
 499 static tree handle_constructor_attribute (tree *, tree, tree, int, bool *);
 500 static tree handle_destructor_attribute (tree *, tree, tree, int, bool *);
 501 static tree handle_mode_attribute (tree *, tree, tree, int, bool *);
 502 static tree handle_section_attribute (tree *, tree, tree, int, bool *);
 503 static tree handle_aligned_attribute (tree *, tree, tree, int, bool *);
 504 static tree handle_weak_attribute (tree *, tree, tree, int, bool *) ;
 505 static tree handle_alias_attribute (tree *, tree, tree, int, bool *);
 506 static tree handle_weakref_attribute (tree *, tree, tree, int, bool *) ;
 507 static tree handle_visibility_attribute (tree *, tree, tree, int,
 508                                          bool *);
 509 static tree handle_tls_model_attribute (tree *, tree, tree, int,
 510                                         bool *);
 511 static tree handle_no_instrument_function_attribute (tree *, tree,
 512                                                      tree, int, bool *);
 513 static tree handle_malloc_attribute (tree *, tree, tree, int, bool *);
 514 static tree handle_returns_twice_attribute (tree *, tree, tree, int, bool *);
 515 static tree handle_no_limit_stack_attribute (tree *, tree, tree, int,
 516                                              bool *);
 517 static tree handle_pure_attribute (tree *, tree, tree, int, bool *);
 518 static tree handle_novops_attribute (tree *, tree, tree, int, bool *);
 519 static tree handle_deprecated_attribute (tree *, tree, tree, int,
 520                                          bool *);
 521 static tree handle_vector_size_attribute (tree *, tree, tree, int,
 522                                           bool *);
 523 static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *);
 524 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
 525 static tree handle_cleanup_attribute (tree *, tree, tree, int, bool *);
 526 static tree handle_warn_unused_result_attribute (tree *, tree, tree, int,
 527                                                  bool *);
 528 static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *);
 529 static tree handle_type_generic_attribute (tree *, tree, tree, int, bool *);
 530 static tree handle_alloc_size_attribute (tree *, tree, tree, int, bool *);
 531 static tree handle_target_attribute (tree *, tree, tree, int, bool *);
 532 static tree handle_optimize_attribute (tree *, tree, tree, int, bool *);
 533
 534 static void check_function_nonnull (tree, int, tree *);
 535 static void check_nonnull_arg (void *, tree, unsigned HOST_WIDE_INT);
 536 static bool nonnull_check_p (tree, unsigned HOST_WIDE_INT);
 537 static bool get_nonnull_operand (tree, unsigned HOST_WIDE_INT *);
 538 static int resort_field_decl_cmp (const void *, const void *);
 539
 540 /* Reserved words.  The third field is a mask: keywords are disabled
 541    if they match the mask.
 542
 543    Masks for languages:
 544    C --std=c89: D_C99 | D_CXXONLY | D_OBJC | D_CXX_OBJC
 545    C --std=c99: D_CXXONLY | D_OBJC
 546    ObjC is like C except that D_OBJC and D_CXX_OBJC are not set
 547    C++ --std=c98: D_CONLY | D_CXXOX | D_OBJC
 548    C++ --std=c0x: D_CONLY | D_OBJC
 549    ObjC++ is like C++ except that D_OBJC is not set
 550
 551    If -fno-asm is used, D_ASM is added to the mask.  If
 552    -fno-gnu-keywords is used, D_EXT is added.  If -fno-asm and C in
 553    C89 mode, D_EXT89 is added for both -fno-asm and -fno-gnu-keywords.
 554    In C with -Wc++-compat, we warn if D_CXXWARN is set.  */
 555
 556 const struct c_common_resword c_common_reswords[] =
 557 {
 558   { "_Bool",            RID_BOOL,      D_CONLY },
 559   { "_Complex",         RID_COMPLEX,    0 },
 560   { "_Imaginary",       RID_IMAGINARY, D_CONLY },
 561   { "_Decimal32",       RID_DFLOAT32,  D_CONLY | D_EXT },
 562   { "_Decimal64",       RID_DFLOAT64,  D_CONLY | D_EXT },
 563   { "_Decimal128",      RID_DFLOAT128, D_CONLY | D_EXT },
 564   { "_Fract",           RID_FRACT,     D_CONLY | D_EXT },
 565   { "_Accum",           RID_ACCUM,     D_CONLY | D_EXT },
 566   { "_Sat",             RID_SAT,       D_CONLY | D_EXT },
 567   { "__FUNCTION__",     RID_FUNCTION_NAME, 0 },
 568   { "__PRETTY_FUNCTION__", RID_PRETTY_FUNCTION_NAME, 0 },
 569   { "__alignof",        RID_ALIGNOF,    0 },
 570   { "__alignof__",      RID_ALIGNOF,    0 },
 571   { "__asm",            RID_ASM,        0 },
 572   { "__asm__",          RID_ASM,        0 },
 573   { "__attribute",      RID_ATTRIBUTE,  0 },
 574   { "__attribute__",    RID_ATTRIBUTE,  0 },
 575   { "__builtin_choose_expr", RID_CHOOSE_EXPR, D_CONLY },
 576   { "__builtin_offsetof", RID_OFFSETOF, 0 },
 577   { "__builtin_types_compatible_p", RID_TYPES_COMPATIBLE_P, D_CONLY },
 578   { "__builtin_va_arg", RID_VA_ARG,     0 },
 579   { "__complex",        RID_COMPLEX,    0 },
 580   { "__complex__",      RID_COMPLEX,    0 },
 581   { "__const",          RID_CONST,      0 },
 582   { "__const__",        RID_CONST,      0 },
 583   { "__decltype",       RID_DECLTYPE,   D_CXXONLY },
 584   { "__extension__",    RID_EXTENSION,  0 },
 585   { "__func__",         RID_C99_FUNCTION_NAME, 0 },
 586   { "__has_nothrow_assign", RID_HAS_NOTHROW_ASSIGN, D_CXXONLY },
 587   { "__has_nothrow_constructor", RID_HAS_NOTHROW_CONSTRUCTOR, D_CXXONLY },
 588   { "__has_nothrow_copy", RID_HAS_NOTHROW_COPY, D_CXXONLY },
 589   { "__has_trivial_assign", RID_HAS_TRIVIAL_ASSIGN, D_CXXONLY },
 590   { "__has_trivial_constructor", RID_HAS_TRIVIAL_CONSTRUCTOR, D_CXXONLY },
 591   { "__has_trivial_copy", RID_HAS_TRIVIAL_COPY, D_CXXONLY },
 592   { "__has_trivial_destructor", RID_HAS_TRIVIAL_DESTRUCTOR, D_CXXONLY },
 593   { "__has_virtual_destructor", RID_HAS_VIRTUAL_DESTRUCTOR, D_CXXONLY },
 594   { "__is_abstract",    RID_IS_ABSTRACT, D_CXXONLY },
 595   { "__is_base_of",     RID_IS_BASE_OF, D_CXXONLY },
 596   { "__is_class",       RID_IS_CLASS,   D_CXXONLY },
 597   { "__is_convertible_to", RID_IS_CONVERTIBLE_TO, D_CXXONLY },
 598   { "__is_empty",       RID_IS_EMPTY,   D_CXXONLY },
 599   { "__is_enum",        RID_IS_ENUM,    D_CXXONLY },
 600   { "__is_pod",         RID_IS_POD,     D_CXXONLY },
 601   { "__is_polymorphic", RID_IS_POLYMORPHIC, D_CXXONLY },
 602   { "__is_standard_layout", RID_IS_STD_LAYOUT, D_CXXONLY },
 603   { "__is_trivial",     RID_IS_TRIVIAL, D_CXXONLY },
 604   { "__is_union",       RID_IS_UNION,   D_CXXONLY },
 605   { "__imag",           RID_IMAGPART,   0 },
 606   { "__imag__",         RID_IMAGPART,   0 },
 607   { "__inline",         RID_INLINE,     0 },
 608   { "__inline__",       RID_INLINE,     0 },
 609   { "__label__",        RID_LABEL,      0 },
 610   { "__null",           RID_NULL,       0 },
 611   { "__real",           RID_REALPART,   0 },
 612   { "__real__",         RID_REALPART,   0 },
 613   { "__restrict",       RID_RESTRICT,   0 },
 614   { "__restrict__",     RID_RESTRICT,   0 },
 615   { "__signed",         RID_SIGNED,     0 },
 616   { "__signed__",       RID_SIGNED,     0 },
 617   { "__thread",         RID_THREAD,     0 },
 618   { "__typeof",         RID_TYPEOF,     0 },
 619   { "__typeof__",       RID_TYPEOF,     0 },
 620   { "__volatile",       RID_VOLATILE,   0 },
 621   { "__volatile__",     RID_VOLATILE,   0 },
 622   { "alignof",          RID_ALIGNOF,    D_CXXONLY | D_CXX0X | D_CXXWARN },
 623   { "asm",              RID_ASM,        D_ASM },
 624   { "auto",             RID_AUTO,       0 },
 625   { "bool",             RID_BOOL,       D_CXXONLY | D_CXXWARN },
 626   { "break",            RID_BREAK,      0 },
 627   { "case",             RID_CASE,       0 },
 628   { "catch",            RID_CATCH,      D_CXX_OBJC | D_CXXWARN },
 629   { "char",             RID_CHAR,       0 },
 630   { "char16_t",         RID_CHAR16,     D_CXXONLY | D_CXX0X | D_CXXWARN },
 631   { "char32_t",         RID_CHAR32,     D_CXXONLY | D_CXX0X | D_CXXWARN },
 632   { "class",            RID_CLASS,      D_CXX_OBJC | D_CXXWARN },
 633   { "const",            RID_CONST,      0 },
 634   { "constexpr",        RID_CONSTEXPR,  D_CXXONLY | D_CXX0X | D_CXXWARN },
 635   { "const_cast",       RID_CONSTCAST,  D_CXXONLY | D_CXXWARN },
 636   { "continue",         RID_CONTINUE,   0 },
 637   { "decltype",         RID_DECLTYPE,   D_CXXONLY | D_CXX0X | D_CXXWARN },
 638   { "default",          RID_DEFAULT,    0 },
 639   { "delete",           RID_DELETE,     D_CXXONLY | D_CXXWARN },
 640   { "do",               RID_DO,         0 },
 641   { "double",           RID_DOUBLE,     0 },
 642   { "dynamic_cast",     RID_DYNCAST,    D_CXXONLY | D_CXXWARN },
 643   { "else",             RID_ELSE,       0 },
 644   { "enum",             RID_ENUM,       0 },
 645   { "explicit",         RID_EXPLICIT,   D_CXXONLY | D_CXXWARN },
 646   { "export",           RID_EXPORT,     D_CXXONLY | D_CXXWARN },
 647   { "extern",           RID_EXTERN,     0 },
 648   { "false",            RID_FALSE,      D_CXXONLY | D_CXXWARN },
 649   { "float",            RID_FLOAT,      0 },
 650   { "for",              RID_FOR,        0 },
 651   { "friend",           RID_FRIEND,     D_CXXONLY | D_CXXWARN },
 652   { "goto",             RID_GOTO,       0 },
 653   { "if",               RID_IF,         0 },
 654   { "inline",           RID_INLINE,     D_EXT89 },
 655   { "int",              RID_INT,        0 },
 656   { "long",             RID_LONG,       0 },
 657   { "mutable",          RID_MUTABLE,    D_CXXONLY | D_CXXWARN },
 658   { "namespace",        RID_NAMESPACE,  D_CXXONLY | D_CXXWARN },
 659   { "new",              RID_NEW,        D_CXXONLY | D_CXXWARN },
 660   { "operator",         RID_OPERATOR,   D_CXXONLY | D_CXXWARN },
 661   { "private",          RID_PRIVATE,    D_CXX_OBJC | D_CXXWARN },
 662   { "protected",        RID_PROTECTED,  D_CXX_OBJC | D_CXXWARN },
 663   { "public",           RID_PUBLIC,     D_CXX_OBJC | D_CXXWARN },
 664   { "register",         RID_REGISTER,   0 },
 665   { "reinterpret_cast", RID_REINTCAST,  D_CXXONLY | D_CXXWARN },
 666   { "restrict",         RID_RESTRICT,   D_CONLY | D_C99 },
 667   { "return",           RID_RETURN,     0 },
 668   { "short",            RID_SHORT,      0 },
 669   { "signed",           RID_SIGNED,     0 },
 670   { "sizeof",           RID_SIZEOF,     0 },
 671   { "static",           RID_STATIC,     0 },
 672   { "static_assert",    RID_STATIC_ASSERT, D_CXXONLY | D_CXX0X | D_CXXWARN },
 673   { "static_cast",      RID_STATCAST,   D_CXXONLY | D_CXXWARN },
 674   { "struct",           RID_STRUCT,     0 },
 675   { "switch",           RID_SWITCH,     0 },
 676   { "template",         RID_TEMPLATE,   D_CXXONLY | D_CXXWARN },
 677   { "this",             RID_THIS,       D_CXXONLY | D_CXXWARN },
 678   { "throw",            RID_THROW,      D_CXX_OBJC | D_CXXWARN },
 679   { "true",             RID_TRUE,       D_CXXONLY | D_CXXWARN },
 680   { "try",              RID_TRY,        D_CXX_OBJC | D_CXXWARN },
 681   { "typedef",          RID_TYPEDEF,    0 },
 682   { "typename",         RID_TYPENAME,   D_CXXONLY | D_CXXWARN },
 683   { "typeid",           RID_TYPEID,     D_CXXONLY | D_CXXWARN },
 684   { "typeof",           RID_TYPEOF,     D_ASM | D_EXT },
 685   { "union",            RID_UNION,      0 },
 686   { "unsigned",         RID_UNSIGNED,   0 },
 687   { "using",            RID_USING,      D_CXXONLY | D_CXXWARN },
 688   { "virtual",          RID_VIRTUAL,    D_CXXONLY | D_CXXWARN },
 689   { "void",             RID_VOID,       0 },
 690   { "volatile",         RID_VOLATILE,   0 },
 691   { "wchar_t",          RID_WCHAR,      D_CXXONLY },
 692   { "while",            RID_WHILE,      0 },
 693   /* These Objective-C keywords are recognized only immediately after
 694      an '@'.  */
 695   { "compatibility_alias", RID_AT_ALIAS,        D_OBJC },
 696   { "defs",             RID_AT_DEFS,            D_OBJC },
 697   { "encode",           RID_AT_ENCODE,          D_OBJC },
 698   { "end",              RID_AT_END,             D_OBJC },
 699   { "implementation",   RID_AT_IMPLEMENTATION,  D_OBJC },
 700   { "interface",        RID_AT_INTERFACE,       D_OBJC },
 701   { "protocol",         RID_AT_PROTOCOL,        D_OBJC },
 702   { "selector",         RID_AT_SELECTOR,        D_OBJC },
 703   { "finally",          RID_AT_FINALLY,         D_OBJC },
 704   { "synchronized",     RID_AT_SYNCHRONIZED,    D_OBJC },
 705   /* These are recognized only in protocol-qualifier context
 706      (see above) */
 707   { "bycopy",           RID_BYCOPY,             D_OBJC },
 708   { "byref",            RID_BYREF,              D_OBJC },
 709   { "in",               RID_IN,                 D_OBJC },
 710   { "inout",            RID_INOUT,              D_OBJC },
 711   { "oneway",           RID_ONEWAY,             D_OBJC },
 712   { "out",              RID_OUT,                D_OBJC },
 713
 714 #ifdef TARGET_ADDR_SPACE_KEYWORDS
 715   /* Any address space keywords recognized by the target.  */
 716   TARGET_ADDR_SPACE_KEYWORDS,
 717 #endif
 718 };
 719
 720 const unsigned int num_c_common_reswords =
 721   sizeof c_common_reswords / sizeof (struct c_common_resword);
 722
 723 /* Table of machine-independent attributes common to all C-like languages.  */
 724 const struct attribute_spec c_common_attribute_table[] =
 725 {
 726   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 727   { "packed",                 0, 0, false, false, false,
 728                               handle_packed_attribute },
 729   { "nocommon",               0, 0, true,  false, false,
 730                               handle_nocommon_attribute },
 731   { "common",                 0, 0, true,  false, false,
 732                               handle_common_attribute },
 733   /* FIXME: logically, noreturn attributes should be listed as
 734      "false, true, true" and apply to function types.  But implementing this
 735      would require all the places in the compiler that use TREE_THIS_VOLATILE
 736      on a decl to identify non-returning functions to be located and fixed
 737      to check the function type instead.  */
 738   { "noreturn",               0, 0, true,  false, false,
 739                               handle_noreturn_attribute },
 740   { "volatile",               0, 0, true,  false, false,
 741                               handle_noreturn_attribute },
 742   { "noinline",               0, 0, true,  false, false,
 743                               handle_noinline_attribute },
 744   { "noclone",                0, 0, true,  false, false,
 745                               handle_noclone_attribute },
 746   { "always_inline",          0, 0, true,  false, false,
 747                               handle_always_inline_attribute },
 748   { "gnu_inline",             0, 0, true,  false, false,
 749                               handle_gnu_inline_attribute },
 750   { "artificial",             0, 0, true,  false, false,
 751                               handle_artificial_attribute },
 752   { "flatten",                0, 0, true,  false, false,
 753                               handle_flatten_attribute },
 754   { "used",                   0, 0, true,  false, false,
 755                               handle_used_attribute },
 756   { "unused",                 0, 0, false, false, false,
 757                               handle_unused_attribute },
 758   { "externally_visible",     0, 0, true,  false, false,
 759                               handle_externally_visible_attribute },
 760   /* The same comments as for noreturn attributes apply to const ones.  */
 761   { "const",                  0, 0, true,  false, false,
 762                               handle_const_attribute },
 763   { "transparent_union",      0, 0, false, false, false,
 764                               handle_transparent_union_attribute },
 765   { "constructor",            0, 1, true,  false, false,
 766                               handle_constructor_attribute },
 767   { "destructor",             0, 1, true,  false, false,
 768                               handle_destructor_attribute },
 769   { "mode",                   1, 1, false,  true, false,
 770                               handle_mode_attribute },
 771   { "section",                1, 1, true,  false, false,
 772                               handle_section_attribute },
 773   { "aligned",                0, 1, false, false, false,
 774                               handle_aligned_attribute },
 775   { "weak",                   0, 0, true,  false, false,
 776                               handle_weak_attribute },
 777   { "alias",                  1, 1, true,  false, false,
 778                               handle_alias_attribute },
 779   { "weakref",                0, 1, true,  false, false,
 780                               handle_weakref_attribute },
 781   { "no_instrument_function", 0, 0, true,  false, false,
 782                               handle_no_instrument_function_attribute },
 783   { "malloc",                 0, 0, true,  false, false,
 784                               handle_malloc_attribute },
 785   { "returns_twice",          0, 0, true,  false, false,
 786                               handle_returns_twice_attribute },
 787   { "no_stack_limit",         0, 0, true,  false, false,
 788                               handle_no_limit_stack_attribute },
 789   { "pure",                   0, 0, true,  false, false,
 790                               handle_pure_attribute },
 791   /* For internal use (marking of builtins) only.  The name contains space
 792      to prevent its usage in source code.  */
 793   { "no vops",                0, 0, true,  false, false,
 794                               handle_novops_attribute },
 795   { "deprecated",             0, 1, false, false, false,
 796                               handle_deprecated_attribute },
 797   { "vector_size",            1, 1, false, true, false,
 798                               handle_vector_size_attribute },
 799   { "visibility",             1, 1, false, false, false,
 800                               handle_visibility_attribute },
 801   { "tls_model",              1, 1, true,  false, false,
 802                               handle_tls_model_attribute },
 803   { "nonnull",                0, -1, false, true, true,
 804                               handle_nonnull_attribute },
 805   { "nothrow",                0, 0, true,  false, false,
 806                               handle_nothrow_attribute },
 807   { "may_alias",              0, 0, false, true, false, NULL },
 808   { "cleanup",                1, 1, true, false, false,
 809                               handle_cleanup_attribute },
 810   { "warn_unused_result",     0, 0, false, true, true,
 811                               handle_warn_unused_result_attribute },
 812   { "sentinel",               0, 1, false, true, true,
 813                               handle_sentinel_attribute },
 814   /* For internal use (marking of builtins) only.  The name contains space
 815      to prevent its usage in source code.  */
 816   { "type generic",           0, 0, false, true, true,
 817                               handle_type_generic_attribute },
 818   { "alloc_size",             1, 2, false, true, true,
 819                               handle_alloc_size_attribute },
 820   { "cold",                   0, 0, true,  false, false,
 821                               handle_cold_attribute },
 822   { "hot",                    0, 0, true,  false, false,
 823                               handle_hot_attribute },
 824   { "warning",                1, 1, true,  false, false,
 825                               handle_error_attribute },
 826   { "error",                  1, 1, true,  false, false,
 827                               handle_error_attribute },
 828   { "target",                 1, -1, true, false, false,
 829                               handle_target_attribute },
 830   { "optimize",               1, -1, true, false, false,
 831                               handle_optimize_attribute },
 832   { NULL,                     0, 0, false, false, false, NULL }
 833 };
 834
 835 /* Give the specifications for the format attributes, used by C and all
 836    descendants.  */
 837
 838 const struct attribute_spec c_common_format_attribute_table[] =
 839 {
 840   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 841   { "format",                 3, 3, false, true,  true,
 842                               handle_format_attribute },
 843   { "format_arg",             1, 1, false, true,  true,
 844                               handle_format_arg_attribute },
 845   { NULL,                     0, 0, false, false, false, NULL }
 846 };
 847
 848 /* Return identifier for address space AS.  */
 849 const char *
 850 c_addr_space_name (addr_space_t as)
 851 {
 852   unsigned int i;
 853
 854   for (i = 0; i < num_c_common_reswords; i++)
 855     if (c_common_reswords[i].rid == RID_FIRST_ADDR_SPACE + as)
 856       return c_common_reswords[i].word;
 857
 858   gcc_unreachable ();
 859 }
 860
 861 /* Push current bindings for the function name VAR_DECLS.  */
 862
 863 void
 864 start_fname_decls (void)
 865 {
 866   unsigned ix;
 867   tree saved = NULL_TREE;
 868
 869   for (ix = 0; fname_vars[ix].decl; ix++)
 870     {
 871       tree decl = *fname_vars[ix].decl;
 872
 873       if (decl)
 874         {
 875           saved = tree_cons (decl, build_int_cst (NULL_TREE, ix), saved);
 876           *fname_vars[ix].decl = NULL_TREE;
 877         }
 878     }
 879   if (saved || saved_function_name_decls)
 880     /* Normally they'll have been NULL, so only push if we've got a
 881        stack, or they are non-NULL.  */
 882     saved_function_name_decls = tree_cons (saved, NULL_TREE,
 883                                            saved_function_name_decls);
 884 }
 885
 886 /* Finish up the current bindings, adding them into the current function's
 887    statement tree.  This must be done _before_ finish_stmt_tree is called.
 888    If there is no current function, we must be at file scope and no statements
 889    are involved. Pop the previous bindings.  */
 890
 891 void
 892 finish_fname_decls (void)
 893 {
 894   unsigned ix;
 895   tree stmts = NULL_TREE;
 896   tree stack = saved_function_name_decls;
 897
 898   for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack))
 899     append_to_statement_list (TREE_VALUE (stack), &stmts);
 900
 901   if (stmts)
 902     {
 903       tree *bodyp = &DECL_SAVED_TREE (current_function_decl);
 904
 905       if (TREE_CODE (*bodyp) == BIND_EXPR)
 906         bodyp = &BIND_EXPR_BODY (*bodyp);
 907
 908       append_to_statement_list_force (*bodyp, &stmts);
 909       *bodyp = stmts;
 910     }
 911
 912   for (ix = 0; fname_vars[ix].decl; ix++)
 913     *fname_vars[ix].decl = NULL_TREE;
 914
 915   if (stack)
 916     {
 917       /* We had saved values, restore them.  */
 918       tree saved;
 919
 920       for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved))
 921         {
 922           tree decl = TREE_PURPOSE (saved);
 923           unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved));
 924
 925           *fname_vars[ix].decl = decl;
 926         }
 927       stack = TREE_CHAIN (stack);
 928     }
 929   saved_function_name_decls = stack;
 930 }
 931
 932 /* Return the text name of the current function, suitably prettified
 933    by PRETTY_P.  Return string must be freed by caller.  */
 934
 935 const char *
 936 fname_as_string (int pretty_p)
 937 {
 938   const char *name = "top level";
 939   char *namep;
 940   int vrb = 2, len;
 941   cpp_string cstr = { 0, 0 }, strname;
 942
 943   if (!pretty_p)
 944     {
 945       name = "";
 946       vrb = 0;
 947     }
 948
 949   if (current_function_decl)
 950     name = lang_hooks.decl_printable_name (current_function_decl, vrb);
 951
 952   len = strlen (name) + 3; /* Two for '"'s.  One for NULL.  */
 953
 954   namep = XNEWVEC (char, len);
 955   snprintf (namep, len, "\"%s\"", name);
 956   strname.text = (unsigned char *) namep;
 957   strname.len = len - 1;
 958
 959   if (cpp_interpret_string (parse_in, &strname, 1, &cstr, CPP_STRING))
 960     {
 961       XDELETEVEC (namep);
 962       return (const char *) cstr.text;
 963     }
 964
 965   return namep;
 966 }
 967
 968 /* Return the VAR_DECL for a const char array naming the current
 969    function. If the VAR_DECL has not yet been created, create it
 970    now. RID indicates how it should be formatted and IDENTIFIER_NODE
 971    ID is its name (unfortunately C and C++ hold the RID values of
 972    keywords in different places, so we can't derive RID from ID in
 973    this language independent code. LOC is the location of the
 974    function.  */
 975
 976 tree
 977 fname_decl (location_t loc, unsigned int rid, tree id)
 978 {
 979   unsigned ix;
 980   tree decl = NULL_TREE;
 981
 982   for (ix = 0; fname_vars[ix].decl; ix++)
 983     if (fname_vars[ix].rid == rid)
 984       break;
 985
 986   decl = *fname_vars[ix].decl;
 987   if (!decl)
 988     {
 989       /* If a tree is built here, it would normally have the lineno of
 990          the current statement.  Later this tree will be moved to the
 991          beginning of the function and this line number will be wrong.
 992          To avoid this problem set the lineno to 0 here; that prevents
 993          it from appearing in the RTL.  */
 994       tree stmts;
 995       location_t saved_location = input_location;
 996       input_location = UNKNOWN_LOCATION;
 997
 998       stmts = push_stmt_list ();
 999       decl = (*make_fname_decl) (loc, id, fname_vars[ix].pretty);
1000       stmts = pop_stmt_list (stmts);
1001       if (!IS_EMPTY_STMT (stmts))
1002         saved_function_name_decls
1003           = tree_cons (decl, stmts, saved_function_name_decls);
1004       *fname_vars[ix].decl = decl;
1005       input_location = saved_location;
1006     }
1007   if (!ix && !current_function_decl)
1008     pedwarn (loc, 0, "%qD is not defined outside of function scope", decl);
1009
1010   return decl;
1011 }
1012
1013 /* Given a STRING_CST, give it a suitable array-of-chars data type.  */
1014
1015 tree
1016 fix_string_type (tree value)
1017 {
1018   int length = TREE_STRING_LENGTH (value);
1019   int nchars;
1020   tree e_type, i_type, a_type;
1021
1022   /* Compute the number of elements, for the array type.  */
1023   if (TREE_TYPE (value) == char_array_type_node || !TREE_TYPE (value))
1024     {
1025       nchars = length;
1026       e_type = char_type_node;
1027     }
1028   else if (TREE_TYPE (value) == char16_array_type_node)
1029     {
1030       nchars = length / (TYPE_PRECISION (char16_type_node) / BITS_PER_UNIT);
1031       e_type = char16_type_node;
1032     }
1033   else if (TREE_TYPE (value) == char32_array_type_node)
1034     {
1035       nchars = length / (TYPE_PRECISION (char32_type_node) / BITS_PER_UNIT);
1036       e_type = char32_type_node;
1037     }
1038   else
1039     {
1040       nchars = length / (TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT);
1041       e_type = wchar_type_node;
1042     }
1043
1044   /* C89 2.2.4.1, C99 5.2.4.1 (Translation limits).  The analogous
1045      limit in C++98 Annex B is very large (65536) and is not normative,
1046      so we do not diagnose it (warn_overlength_strings is forced off
1047      in c_common_post_options).  */
1048   if (warn_overlength_strings)
1049     {
1050       const int nchars_max = flag_isoc99 ? 4095 : 509;
1051       const int relevant_std = flag_isoc99 ? 99 : 90;
1052       if (nchars - 1 > nchars_max)
1053         /* Translators: The %d after 'ISO C' will be 90 or 99.  Do not
1054            separate the %d from the 'C'.  'ISO' should not be
1055            translated, but it may be moved after 'C%d' in languages
1056            where modifiers follow nouns.  */
1057         pedwarn (input_location, OPT_Woverlength_strings,
1058                  "string length %qd is greater than the length %qd "
1059                  "ISO C%d compilers are required to support",
1060                  nchars - 1, nchars_max, relevant_std);
1061     }
1062
1063   /* Create the array type for the string constant.  The ISO C++
1064      standard says that a string literal has type `const char[N]' or
1065      `const wchar_t[N]'.  We use the same logic when invoked as a C
1066      front-end with -Wwrite-strings.
1067      ??? We should change the type of an expression depending on the
1068      state of a warning flag.  We should just be warning -- see how
1069      this is handled in the C++ front-end for the deprecated implicit
1070      conversion from string literals to `char*' or `wchar_t*'.
1071
1072      The C++ front end relies on TYPE_MAIN_VARIANT of a cv-qualified
1073      array type being the unqualified version of that type.
1074      Therefore, if we are constructing an array of const char, we must
1075      construct the matching unqualified array type first.  The C front
1076      end does not require this, but it does no harm, so we do it
1077      unconditionally.  */
1078   i_type = build_index_type (build_int_cst (NULL_TREE, nchars - 1));
1079   a_type = build_array_type (e_type, i_type);
1080   if (c_dialect_cxx() || warn_write_strings)
1081     a_type = c_build_qualified_type (a_type, TYPE_QUAL_CONST);
1082
1083   TREE_TYPE (value) = a_type;
1084   TREE_CONSTANT (value) = 1;
1085   TREE_READONLY (value) = 1;
1086   TREE_STATIC (value) = 1;
1087   return value;
1088 }
1089 \f
1090 /* Fully fold EXPR, an expression that was not folded (beyond integer
1091    constant expressions and null pointer constants) when being built
1092    up.  If IN_INIT, this is in a static initializer and certain
1093    changes are made to the folding done.  Clear *MAYBE_CONST if
1094    MAYBE_CONST is not NULL and EXPR is definitely not a constant
1095    expression because it contains an evaluated operator (in C99) or an
1096    operator outside of sizeof returning an integer constant (in C90)
1097    not permitted in constant expressions, or because it contains an
1098    evaluated arithmetic overflow.  (*MAYBE_CONST should typically be
1099    set to true by callers before calling this function.)  Return the
1100    folded expression.  Function arguments have already been folded
1101    before calling this function, as have the contents of SAVE_EXPR,
1102    TARGET_EXPR, BIND_EXPR, VA_ARG_EXPR, OBJ_TYPE_REF and
1103    C_MAYBE_CONST_EXPR.  */
1104
1105 tree
1106 c_fully_fold (tree expr, bool in_init, bool *maybe_const)
1107 {
1108   tree ret;
1109   tree eptype = NULL_TREE;
1110   bool dummy = true;
1111   bool maybe_const_itself = true;
1112   location_t loc = EXPR_LOCATION (expr);
1113
1114   /* This function is not relevant to C++ because C++ folds while
1115      parsing, and may need changes to be correct for C++ when C++
1116      stops folding while parsing.  */
1117   if (c_dialect_cxx ())
1118     gcc_unreachable ();
1119
1120   if (!maybe_const)
1121     maybe_const = &dummy;
1122   if (TREE_CODE (expr) == EXCESS_PRECISION_EXPR)
1123     {
1124       eptype = TREE_TYPE (expr);
1125       expr = TREE_OPERAND (expr, 0);
1126     }
1127   ret = c_fully_fold_internal (expr, in_init, maybe_const,
1128                                &maybe_const_itself);
1129   if (eptype)
1130     ret = fold_convert_loc (loc, eptype, ret);
1131   *maybe_const &= maybe_const_itself;
1132   return ret;
1133 }
1134
1135 /* Internal helper for c_fully_fold.  EXPR and IN_INIT are as for
1136    c_fully_fold.  *MAYBE_CONST_OPERANDS is cleared because of operands
1137    not permitted, while *MAYBE_CONST_ITSELF is cleared because of
1138    arithmetic overflow (for C90, *MAYBE_CONST_OPERANDS is carried from
1139    both evaluated and unevaluated subexpressions while
1140    *MAYBE_CONST_ITSELF is carried from only evaluated
1141    subexpressions).  */
1142
1143 static tree
1144 c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands,
1145                        bool *maybe_const_itself)
1146 {
1147   tree ret = expr;
1148   enum tree_code code = TREE_CODE (expr);
1149   enum tree_code_class kind = TREE_CODE_CLASS (code);
1150   location_t loc = EXPR_LOCATION (expr);
1151   tree op0, op1, op2, op3;
1152   tree orig_op0, orig_op1, orig_op2;
1153   bool op0_const = true, op1_const = true, op2_const = true;
1154   bool op0_const_self = true, op1_const_self = true, op2_const_self = true;
1155   bool nowarning = TREE_NO_WARNING (expr);
1156   int unused_p;
1157
1158   /* This function is not relevant to C++ because C++ folds while
1159      parsing, and may need changes to be correct for C++ when C++
1160      stops folding while parsing.  */
1161   if (c_dialect_cxx ())
1162     gcc_unreachable ();
1163
1164   /* Constants, declarations, statements, errors, SAVE_EXPRs and
1165      anything else not counted as an expression cannot usefully be
1166      folded further at this point.  */
1167   if (!IS_EXPR_CODE_CLASS (kind)
1168       || kind == tcc_statement
1169       || code == SAVE_EXPR)
1170     return expr;
1171
1172   /* Operands of variable-length expressions (function calls) have
1173      already been folded, as have __builtin_* function calls, and such
1174      expressions cannot occur in constant expressions.  */
1175   if (kind == tcc_vl_exp)
1176     {
1177       *maybe_const_operands = false;
1178       ret = fold (expr);
1179       goto out;
1180     }
1181
1182   if (code == C_MAYBE_CONST_EXPR)
1183     {
1184       tree pre = C_MAYBE_CONST_EXPR_PRE (expr);
1185       tree inner = C_MAYBE_CONST_EXPR_EXPR (expr);
1186       if (C_MAYBE_CONST_EXPR_NON_CONST (expr))
1187         *maybe_const_operands = false;
1188       if (C_MAYBE_CONST_EXPR_INT_OPERANDS (expr))
1189         *maybe_const_itself = false;
1190       if (pre && !in_init)
1191         ret = build2 (COMPOUND_EXPR, TREE_TYPE (expr), pre, inner);
1192       else
1193         ret = inner;
1194       goto out;
1195     }
1196
1197   /* Assignment, increment, decrement, function call and comma
1198      operators, and statement expressions, cannot occur in constant
1199      expressions if evaluated / outside of sizeof.  (Function calls
1200      were handled above, though VA_ARG_EXPR is treated like a function
1201      call here, and statement expressions are handled through
1202      C_MAYBE_CONST_EXPR to avoid folding inside them.)  */
1203   switch (code)
1204     {
1205     case MODIFY_EXPR:
1206     case PREDECREMENT_EXPR:
1207     case PREINCREMENT_EXPR:
1208     case POSTDECREMENT_EXPR:
1209     case POSTINCREMENT_EXPR:
1210     case COMPOUND_EXPR:
1211       *maybe_const_operands = false;
1212       break;
1213
1214     case VA_ARG_EXPR:
1215     case TARGET_EXPR:
1216     case BIND_EXPR:
1217     case OBJ_TYPE_REF:
1218       *maybe_const_operands = false;
1219       ret = fold (expr);
1220       goto out;
1221
1222     default:
1223       break;
1224     }
1225
1226   /* Fold individual tree codes as appropriate.  */
1227   switch (code)
1228     {
1229     case COMPOUND_LITERAL_EXPR:
1230       /* Any non-constancy will have been marked in a containing
1231          C_MAYBE_CONST_EXPR; there is no more folding to do here.  */
1232       goto out;
1233
1234     case COMPONENT_REF:
1235       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1236       op1 = TREE_OPERAND (expr, 1);
1237       op2 = TREE_OPERAND (expr, 2);
1238       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1239                                    maybe_const_itself);
1240       STRIP_TYPE_NOPS (op0);
1241       if (op0 != orig_op0)
1242         ret = build3 (COMPONENT_REF, TREE_TYPE (expr), op0, op1, op2);
1243       if (ret != expr)
1244         {
1245           TREE_READONLY (ret) = TREE_READONLY (expr);
1246           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1247         }
1248       goto out;
1249
1250     case ARRAY_REF:
1251       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1252       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1253       op2 = TREE_OPERAND (expr, 2);
1254       op3 = TREE_OPERAND (expr, 3);
1255       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1256                                    maybe_const_itself);
1257       STRIP_TYPE_NOPS (op0);
1258       op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
1259                                    maybe_const_itself);
1260       STRIP_TYPE_NOPS (op1);
1261       op1 = decl_constant_value_for_optimization (op1);
1262       if (op0 != orig_op0 || op1 != orig_op1)
1263         ret = build4 (ARRAY_REF, TREE_TYPE (expr), op0, op1, op2, op3);
1264       if (ret != expr)
1265         {
1266           TREE_READONLY (ret) = TREE_READONLY (expr);
1267           TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (expr);
1268           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1269         }
1270       ret = fold (ret);
1271       goto out;
1272
1273     case COMPOUND_EXPR:
1274     case MODIFY_EXPR:
1275     case PREDECREMENT_EXPR:
1276     case PREINCREMENT_EXPR:
1277     case POSTDECREMENT_EXPR:
1278     case POSTINCREMENT_EXPR:
1279     case PLUS_EXPR:
1280     case MINUS_EXPR:
1281     case MULT_EXPR:
1282     case POINTER_PLUS_EXPR:
1283     case TRUNC_DIV_EXPR:
1284     case CEIL_DIV_EXPR:
1285     case FLOOR_DIV_EXPR:
1286     case TRUNC_MOD_EXPR:
1287     case RDIV_EXPR:
1288     case EXACT_DIV_EXPR:
1289     case LSHIFT_EXPR:
1290     case RSHIFT_EXPR:
1291     case BIT_IOR_EXPR:
1292     case BIT_XOR_EXPR:
1293     case BIT_AND_EXPR:
1294     case LT_EXPR:
1295     case LE_EXPR:
1296     case GT_EXPR:
1297     case GE_EXPR:
1298     case EQ_EXPR:
1299     case NE_EXPR:
1300     case COMPLEX_EXPR:
1301     case TRUTH_AND_EXPR:
1302     case TRUTH_OR_EXPR:
1303     case TRUTH_XOR_EXPR:
1304     case UNORDERED_EXPR:
1305     case ORDERED_EXPR:
1306     case UNLT_EXPR:
1307     case UNLE_EXPR:
1308     case UNGT_EXPR:
1309     case UNGE_EXPR:
1310     case UNEQ_EXPR:
1311       /* Binary operations evaluating both arguments (increment and
1312          decrement are binary internally in GCC).  */
1313       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1314       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1315       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1316                                    maybe_const_itself);
1317       STRIP_TYPE_NOPS (op0);
1318       if (code != MODIFY_EXPR
1319           && code != PREDECREMENT_EXPR
1320           && code != PREINCREMENT_EXPR
1321           && code != POSTDECREMENT_EXPR
1322           && code != POSTINCREMENT_EXPR)
1323         op0 = decl_constant_value_for_optimization (op0);
1324       /* The RHS of a MODIFY_EXPR was fully folded when building that
1325          expression for the sake of conversion warnings.  */
1326       if (code != MODIFY_EXPR)
1327         op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
1328                                      maybe_const_itself);
1329       STRIP_TYPE_NOPS (op1);
1330       op1 = decl_constant_value_for_optimization (op1);
1331       if (op0 != orig_op0 || op1 != orig_op1 || in_init)
1332         ret = in_init
1333           ? fold_build2_initializer_loc (loc, code, TREE_TYPE (expr), op0, op1)
1334           : fold_build2_loc (loc, code, TREE_TYPE (expr), op0, op1);
1335       else
1336         ret = fold (expr);
1337       if (TREE_OVERFLOW_P (ret)
1338           && !TREE_OVERFLOW_P (op0)
1339           && !TREE_OVERFLOW_P (op1))
1340         overflow_warning (EXPR_LOCATION (expr), ret);
1341       goto out;
1342
1343     case INDIRECT_REF:
1344     case FIX_TRUNC_EXPR:
1345     case FLOAT_EXPR:
1346     CASE_CONVERT:
1347     case NON_LVALUE_EXPR:
1348     case NEGATE_EXPR:
1349     case BIT_NOT_EXPR:
1350     case TRUTH_NOT_EXPR:
1351     case ADDR_EXPR:
1352     case CONJ_EXPR:
1353     case REALPART_EXPR:
1354     case IMAGPART_EXPR:
1355       /* Unary operations.  */
1356       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1357       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1358                                    maybe_const_itself);
1359       STRIP_TYPE_NOPS (op0);
1360       if (code != ADDR_EXPR && code != REALPART_EXPR && code != IMAGPART_EXPR)
1361         op0 = decl_constant_value_for_optimization (op0);
1362       if (op0 != orig_op0 || in_init)
1363         ret = in_init
1364           ? fold_build1_initializer_loc (loc, code, TREE_TYPE (expr), op0)
1365           : fold_build1_loc (loc, code, TREE_TYPE (expr), op0);
1366       else
1367         ret = fold (expr);
1368       if (code == INDIRECT_REF
1369           && ret != expr
1370           && TREE_CODE (ret) == INDIRECT_REF)
1371         {
1372           TREE_READONLY (ret) = TREE_READONLY (expr);
1373           TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (expr);
1374           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1375         }
1376       switch (code)
1377         {
1378         case FIX_TRUNC_EXPR:
1379         case FLOAT_EXPR:
1380         CASE_CONVERT:
1381           /* Don't warn about explicit conversions.  We will already
1382              have warned about suspect implicit conversions.  */
1383           break;
1384
1385         default:
1386           if (TREE_OVERFLOW_P (ret) && !TREE_OVERFLOW_P (op0))
1387             overflow_warning (EXPR_LOCATION (expr), ret);
1388           break;
1389         }
1390       goto out;
1391
1392     case TRUTH_ANDIF_EXPR:
1393     case TRUTH_ORIF_EXPR:
1394       /* Binary operations not necessarily evaluating both
1395          arguments.  */
1396       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1397       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1398       op0 = c_fully_fold_internal (op0, in_init, &op0_const, &op0_const_self);
1399       STRIP_TYPE_NOPS (op0);
1400
1401       unused_p = (op0 == (code == TRUTH_ANDIF_EXPR
1402                           ? truthvalue_false_node
1403                           : truthvalue_true_node));
1404       c_inhibit_evaluation_warnings += unused_p;
1405       op1 = c_fully_fold_internal (op1, in_init, &op1_const, &op1_const_self);
1406       STRIP_TYPE_NOPS (op1);
1407       c_inhibit_evaluation_warnings -= unused_p;
1408
1409       if (op0 != orig_op0 || op1 != orig_op1 || in_init)
1410         ret = in_init
1411           ? fold_build2_initializer_loc (loc, code, TREE_TYPE (expr), op0, op1)
1412           : fold_build2_loc (loc, code, TREE_TYPE (expr), op0, op1);
1413       else
1414         ret = fold (expr);
1415       *maybe_const_operands &= op0_const;
1416       *maybe_const_itself &= op0_const_self;
1417       if (!(flag_isoc99
1418             && op0_const
1419             && op0_const_self
1420             && (code == TRUTH_ANDIF_EXPR
1421                 ? op0 == truthvalue_false_node
1422                 : op0 == truthvalue_true_node)))
1423         *maybe_const_operands &= op1_const;
1424       if (!(op0_const
1425             && op0_const_self
1426             && (code == TRUTH_ANDIF_EXPR
1427                 ? op0 == truthvalue_false_node
1428                 : op0 == truthvalue_true_node)))
1429         *maybe_const_itself &= op1_const_self;
1430       goto out;
1431
1432     case COND_EXPR:
1433       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1434       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1435       orig_op2 = op2 = TREE_OPERAND (expr, 2);
1436       op0 = c_fully_fold_internal (op0, in_init, &op0_const, &op0_const_self);
1437
1438       STRIP_TYPE_NOPS (op0);
1439       c_inhibit_evaluation_warnings += (op0 == truthvalue_false_node);
1440       op1 = c_fully_fold_internal (op1, in_init, &op1_const, &op1_const_self);
1441       STRIP_TYPE_NOPS (op1);
1442       c_inhibit_evaluation_warnings -= (op0 == truthvalue_false_node);
1443
1444       c_inhibit_evaluation_warnings += (op0 == truthvalue_true_node);
1445       op2 = c_fully_fold_internal (op2, in_init, &op2_const, &op2_const_self);
1446       STRIP_TYPE_NOPS (op2);
1447       c_inhibit_evaluation_warnings -= (op0 == truthvalue_true_node);
1448
1449       if (op0 != orig_op0 || op1 != orig_op1 || op2 != orig_op2)
1450         ret = fold_build3_loc (loc, code, TREE_TYPE (expr), op0, op1, op2);
1451       else
1452         ret = fold (expr);
1453       *maybe_const_operands &= op0_const;
1454       *maybe_const_itself &= op0_const_self;
1455       if (!(flag_isoc99
1456             && op0_const
1457             && op0_const_self
1458             && op0 == truthvalue_false_node))
1459         *maybe_const_operands &= op1_const;
1460       if (!(op0_const
1461             && op0_const_self
1462             && op0 == truthvalue_false_node))
1463         *maybe_const_itself &= op1_const_self;
1464       if (!(flag_isoc99
1465             && op0_const
1466             && op0_const_self
1467             && op0 == truthvalue_true_node))
1468         *maybe_const_operands &= op2_const;
1469       if (!(op0_const
1470             && op0_const_self
1471             && op0 == truthvalue_true_node))
1472         *maybe_const_itself &= op2_const_self;
1473       goto out;
1474
1475     case EXCESS_PRECISION_EXPR:
1476       /* Each case where an operand with excess precision may be
1477          encountered must remove the EXCESS_PRECISION_EXPR around
1478          inner operands and possibly put one around the whole
1479          expression or possibly convert to the semantic type (which
1480          c_fully_fold does); we cannot tell at this stage which is
1481          appropriate in any particular case.  */
1482       gcc_unreachable ();
1483
1484     default:
1485       /* Various codes may appear through folding built-in functions
1486          and their arguments.  */
1487       goto out;
1488     }
1489
1490  out:
1491   /* Some folding may introduce NON_LVALUE_EXPRs; all lvalue checks
1492      have been done by this point, so remove them again.  */
1493   nowarning |= TREE_NO_WARNING (ret);
1494   STRIP_TYPE_NOPS (ret);
1495   if (nowarning && !TREE_NO_WARNING (ret))
1496     {
1497       if (!CAN_HAVE_LOCATION_P (ret))
1498         ret = build1 (NOP_EXPR, TREE_TYPE (ret), ret);
1499       TREE_NO_WARNING (ret) = 1;
1500     }
1501   if (ret != expr)
1502     protected_set_expr_location (ret, loc);
1503   return ret;
1504 }
1505
1506 /* If not optimizing, EXP is not a VAR_DECL, or EXP has array type,
1507    return EXP.  Otherwise, return either EXP or its known constant
1508    value (if it has one), but return EXP if EXP has mode BLKmode.  ???
1509    Is the BLKmode test appropriate?  */
1510
1511 tree
1512 decl_constant_value_for_optimization (tree exp)
1513 {
1514   tree ret;
1515
1516   /* This function is only used by C, for c_fully_fold and other
1517      optimization, and may not be correct for C++.  */
1518   if (c_dialect_cxx ())
1519     gcc_unreachable ();
1520
1521   if (!optimize
1522       || TREE_CODE (exp) != VAR_DECL
1523       || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
1524       || DECL_MODE (exp) == BLKmode)
1525     return exp;
1526
1527   ret = decl_constant_value (exp);
1528   /* Avoid unwanted tree sharing between the initializer and current
1529      function's body where the tree can be modified e.g. by the
1530      gimplifier.  */
1531   if (ret != exp && TREE_STATIC (exp))
1532     ret = unshare_expr (ret);
1533   return ret;
1534 }
1535
1536 /* Print a warning if a constant expression had overflow in folding.
1537    Invoke this function on every expression that the language
1538    requires to be a constant expression.
1539    Note the ANSI C standard says it is erroneous for a
1540    constant expression to overflow.  */
1541
1542 void
1543 constant_expression_warning (tree value)
1544 {
1545   if (warn_overflow && pedantic
1546       && (TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
1547           || TREE_CODE (value) == FIXED_CST
1548           || TREE_CODE (value) == VECTOR_CST
1549           || TREE_CODE (value) == COMPLEX_CST)
1550       && TREE_OVERFLOW (value))
1551     pedwarn (input_location, OPT_Woverflow, "overflow in constant expression");
1552 }
1553
1554 /* The same as above but print an unconditional error.  */
1555 void
1556 constant_expression_error (tree value)
1557 {
1558   if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
1559        || TREE_CODE (value) == FIXED_CST
1560        || TREE_CODE (value) == VECTOR_CST
1561        || TREE_CODE (value) == COMPLEX_CST)
1562       && TREE_OVERFLOW (value))
1563     error ("overflow in constant expression");
1564 }
1565
1566 /* Print a warning if an expression had overflow in folding and its
1567    operands hadn't.
1568
1569    Invoke this function on every expression that
1570    (1) appears in the source code, and
1571    (2) is a constant expression that overflowed, and
1572    (3) is not already checked by convert_and_check;
1573    however, do not invoke this function on operands of explicit casts
1574    or when the expression is the result of an operator and any operand
1575    already overflowed.  */
1576
1577 void
1578 overflow_warning (location_t loc, tree value)
1579 {
1580   if (c_inhibit_evaluation_warnings != 0)
1581     return;
1582
1583   switch (TREE_CODE (value))
1584     {
1585     case INTEGER_CST:
1586       warning_at (loc, OPT_Woverflow, "integer overflow in expression");
1587       break;
1588
1589     case REAL_CST:
1590       warning_at (loc, OPT_Woverflow,
1591                   "floating point overflow in expression");
1592       break;
1593
1594     case FIXED_CST:
1595       warning_at (loc, OPT_Woverflow, "fixed-point overflow in expression");
1596       break;
1597
1598     case VECTOR_CST:
1599       warning_at (loc, OPT_Woverflow, "vector overflow in expression");
1600       break;
1601
1602     case COMPLEX_CST:
1603       if (TREE_CODE (TREE_REALPART (value)) == INTEGER_CST)
1604         warning_at (loc, OPT_Woverflow,
1605                     "complex integer overflow in expression");
1606       else if (TREE_CODE (TREE_REALPART (value)) == REAL_CST)
1607         warning_at (loc, OPT_Woverflow,
1608                     "complex floating point overflow in expression");
1609       break;
1610
1611     default:
1612       break;
1613     }
1614 }
1615
1616 /* Warn about uses of logical || / && operator in a context where it
1617    is likely that the bitwise equivalent was intended by the
1618    programmer.  We have seen an expression in which CODE is a binary
1619    operator used to combine expressions OP_LEFT and OP_RIGHT, which before folding
1620    had CODE_LEFT and CODE_RIGHT, into an expression of type TYPE.  */
1621 void
1622 warn_logical_operator (location_t location, enum tree_code code, tree type,
1623                        enum tree_code code_left, tree op_left,
1624                        enum tree_code ARG_UNUSED (code_right), tree op_right)
1625 {
1626   int or_op = (code == TRUTH_ORIF_EXPR || code == TRUTH_OR_EXPR);
1627   int in0_p, in1_p, in_p;
1628   tree low0, low1, low, high0, high1, high, lhs, rhs, tem;
1629   bool strict_overflow_p = false;
1630
1631   if (code != TRUTH_ANDIF_EXPR
1632       && code != TRUTH_AND_EXPR
1633       && code != TRUTH_ORIF_EXPR
1634       && code != TRUTH_OR_EXPR)
1635     return;
1636
1637   /* Warn if &&/|| are being used in a context where it is
1638      likely that the bitwise equivalent was intended by the
1639      programmer. That is, an expression such as op && MASK
1640      where op should not be any boolean expression, nor a
1641      constant, and mask seems to be a non-boolean integer constant.  */
1642   if (!truth_value_p (code_left)
1643       && INTEGRAL_TYPE_P (TREE_TYPE (op_left))
1644       && !CONSTANT_CLASS_P (op_left)
1645       && !TREE_NO_WARNING (op_left)
1646       && TREE_CODE (op_right) == INTEGER_CST
1647       && !integer_zerop (op_right)
1648       && !integer_onep (op_right))
1649     {
1650       if (or_op)
1651         warning_at (location, OPT_Wlogical_op, "logical %<or%>"
1652                     " applied to non-boolean constant");
1653       else
1654         warning_at (location, OPT_Wlogical_op, "logical %<and%>"
1655                     " applied to non-boolean constant");
1656       TREE_NO_WARNING (op_left) = true;
1657       return;
1658     }
1659
1660   /* We do not warn for constants because they are typical of macro
1661      expansions that test for features.  */
1662   if (CONSTANT_CLASS_P (op_left) || CONSTANT_CLASS_P (op_right))
1663     return;
1664
1665   /* This warning only makes sense with logical operands.  */
1666   if (!(truth_value_p (TREE_CODE (op_left))
1667         || INTEGRAL_TYPE_P (TREE_TYPE (op_left)))
1668       || !(truth_value_p (TREE_CODE (op_right))
1669            || INTEGRAL_TYPE_P (TREE_TYPE (op_right))))
1670     return;
1671
1672   lhs = make_range (op_left, &in0_p, &low0, &high0, &strict_overflow_p);
1673   rhs = make_range (op_right, &in1_p, &low1, &high1, &strict_overflow_p);
1674
1675   if (lhs && TREE_CODE (lhs) == C_MAYBE_CONST_EXPR)
1676     lhs = C_MAYBE_CONST_EXPR_EXPR (lhs);
1677
1678   if (rhs && TREE_CODE (rhs) == C_MAYBE_CONST_EXPR)
1679     rhs = C_MAYBE_CONST_EXPR_EXPR (rhs);
1680
1681   /* If this is an OR operation, invert both sides; we will invert
1682      again at the end.  */
1683   if (or_op)
1684     in0_p = !in0_p, in1_p = !in1_p;
1685
1686   /* If both expressions are the same, if we can merge the ranges, and we
1687      can build the range test, return it or it inverted.  */
1688   if (lhs && rhs && operand_equal_p (lhs, rhs, 0)
1689       && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
1690                        in1_p, low1, high1)
1691       && 0 != (tem = build_range_check (UNKNOWN_LOCATION,
1692                                         type, lhs, in_p, low, high)))
1693     {
1694       if (TREE_CODE (tem) != INTEGER_CST)
1695         return;
1696
1697       if (or_op)
1698         warning_at (location, OPT_Wlogical_op,
1699                     "logical %<or%> "
1700                     "of collectively exhaustive tests is always true");
1701       else
1702         warning_at (location, OPT_Wlogical_op,
1703                     "logical %<and%> "
1704                     "of mutually exclusive tests is always false");
1705     }
1706 }
1707
1708
1709 /* Print a warning about casts that might indicate violation
1710    of strict aliasing rules if -Wstrict-aliasing is used and
1711    strict aliasing mode is in effect. OTYPE is the original
1712    TREE_TYPE of EXPR, and TYPE the type we're casting to. */
1713
1714 bool
1715 strict_aliasing_warning (tree otype, tree type, tree expr)
1716 {
1717   /* Strip pointer conversion chains and get to the correct original type.  */
1718   STRIP_NOPS (expr);
1719   otype = TREE_TYPE (expr);
1720
1721   if (!(flag_strict_aliasing
1722         && POINTER_TYPE_P (type)
1723         && POINTER_TYPE_P (otype)
1724         && !VOID_TYPE_P (TREE_TYPE (type)))
1725       /* If the type we are casting to is a ref-all pointer
1726          dereferencing it is always valid.  */
1727       || TYPE_REF_CAN_ALIAS_ALL (type))
1728     return false;
1729
1730   if ((warn_strict_aliasing > 1) && TREE_CODE (expr) == ADDR_EXPR
1731       && (DECL_P (TREE_OPERAND (expr, 0))
1732           || handled_component_p (TREE_OPERAND (expr, 0))))
1733     {
1734       /* Casting the address of an object to non void pointer. Warn
1735          if the cast breaks type based aliasing.  */
1736       if (!COMPLETE_TYPE_P (TREE_TYPE (type)) && warn_strict_aliasing == 2)
1737         {
1738           warning (OPT_Wstrict_aliasing, "type-punning to incomplete type "
1739                    "might break strict-aliasing rules");
1740           return true;
1741         }
1742       else
1743         {
1744           /* warn_strict_aliasing >= 3.   This includes the default (3).
1745              Only warn if the cast is dereferenced immediately.  */
1746           alias_set_type set1 =
1747             get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0)));
1748           alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1749
1750           if (set1 != set2 && set2 != 0
1751               && (set1 == 0 || !alias_sets_conflict_p (set1, set2)))
1752             {
1753               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1754                        "pointer will break strict-aliasing rules");
1755               return true;
1756             }
1757           else if (warn_strict_aliasing == 2
1758                    && !alias_sets_must_conflict_p (set1, set2))
1759             {
1760               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1761                        "pointer might break strict-aliasing rules");
1762               return true;
1763             }
1764         }
1765     }
1766   else
1767     if ((warn_strict_aliasing == 1) && !VOID_TYPE_P (TREE_TYPE (otype)))
1768       {
1769         /* At this level, warn for any conversions, even if an address is
1770            not taken in the same statement.  This will likely produce many
1771            false positives, but could be useful to pinpoint problems that
1772            are not revealed at higher levels.  */
1773         alias_set_type set1 = get_alias_set (TREE_TYPE (otype));
1774         alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1775         if (!COMPLETE_TYPE_P (type)
1776             || !alias_sets_must_conflict_p (set1, set2))
1777           {
1778             warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1779                      "pointer might break strict-aliasing rules");
1780             return true;
1781           }
1782       }
1783
1784   return false;
1785 }
1786
1787 /* Warn for unlikely, improbable, or stupid DECL declarations
1788    of `main'.  */
1789
1790 void
1791 check_main_parameter_types (tree decl)
1792 {
1793   tree args;
1794   int argct = 0;
1795
1796   for (args = TYPE_ARG_TYPES (TREE_TYPE (decl)); args;
1797       args = TREE_CHAIN (args))
1798    {
1799      tree type = args ? TREE_VALUE (args) : 0;
1800
1801      if (type == void_type_node || type == error_mark_node )
1802        break;
1803
1804      ++argct;
1805      switch (argct)
1806        {
1807        case 1:
1808          if (TYPE_MAIN_VARIANT (type) != integer_type_node)
1809            pedwarn (input_location, OPT_Wmain, "first argument of %q+D should be %<int%>",
1810                     decl);
1811          break;
1812
1813        case 2:
1814          if (TREE_CODE (type) != POINTER_TYPE
1815              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1816              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1817                  != char_type_node))
1818            pedwarn (input_location, OPT_Wmain, "second argument of %q+D should be %<char **%>",
1819                     decl);
1820          break;
1821
1822        case 3:
1823          if (TREE_CODE (type) != POINTER_TYPE
1824              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1825              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1826                  != char_type_node))
1827            pedwarn (input_location, OPT_Wmain, "third argument of %q+D should probably be "
1828                     "%<char **%>", decl);
1829          break;
1830        }
1831    }
1832
1833   /* It is intentional that this message does not mention the third
1834     argument because it's only mentioned in an appendix of the
1835     standard.  */
1836   if (argct > 0 && (argct < 2 || argct > 3))
1837     pedwarn (input_location, OPT_Wmain, "%q+D takes only zero or two arguments", decl);
1838 }
1839
1840 /* True if pointers to distinct types T1 and T2 can be converted to
1841    each other without an explicit cast.  Only returns true for opaque
1842    vector types.  */
1843 bool
1844 vector_targets_convertible_p (const_tree t1, const_tree t2)
1845 {
1846   if (TREE_CODE (t1) == VECTOR_TYPE && TREE_CODE (t2) == VECTOR_TYPE
1847       && (TYPE_VECTOR_OPAQUE (t1) || TYPE_VECTOR_OPAQUE (t2))
1848       && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)))
1849     return true;
1850
1851   return false;
1852 }
1853
1854 /* True if vector types T1 and T2 can be converted to each other
1855    without an explicit cast.  If EMIT_LAX_NOTE is true, and T1 and T2
1856    can only be converted with -flax-vector-conversions yet that is not
1857    in effect, emit a note telling the user about that option if such
1858    a note has not previously been emitted.  */
1859 bool
1860 vector_types_convertible_p (const_tree t1, const_tree t2, bool emit_lax_note)
1861 {
1862   static bool emitted_lax_note = false;
1863   bool convertible_lax;
1864
1865   if ((TYPE_VECTOR_OPAQUE (t1) || TYPE_VECTOR_OPAQUE (t2))
1866       && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)))
1867     return true;
1868
1869   convertible_lax =
1870     (tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2))
1871      && (TREE_CODE (TREE_TYPE (t1)) != REAL_TYPE ||
1872          TYPE_PRECISION (t1) == TYPE_PRECISION (t2))
1873      && (INTEGRAL_TYPE_P (TREE_TYPE (t1))
1874          == INTEGRAL_TYPE_P (TREE_TYPE (t2))));
1875
1876   if (!convertible_lax || flag_lax_vector_conversions)
1877     return convertible_lax;
1878
1879   if (TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1880       && lang_hooks.types_compatible_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1881     return true;
1882
1883   if (emit_lax_note && !emitted_lax_note)
1884     {
1885       emitted_lax_note = true;
1886       inform (input_location, "use -flax-vector-conversions to permit "
1887               "conversions between vectors with differing "
1888               "element types or numbers of subparts");
1889     }
1890
1891   return false;
1892 }
1893
1894 /* This is a helper function of build_binary_op.
1895
1896    For certain operations if both args were extended from the same
1897    smaller type, do the arithmetic in that type and then extend.
1898
1899    BITWISE indicates a bitwise operation.
1900    For them, this optimization is safe only if
1901    both args are zero-extended or both are sign-extended.
1902    Otherwise, we might change the result.
1903    Eg, (short)-1 | (unsigned short)-1 is (int)-1
1904    but calculated in (unsigned short) it would be (unsigned short)-1.
1905 */
1906 tree shorten_binary_op (tree result_type, tree op0, tree op1, bool bitwise)
1907 {
1908   int unsigned0, unsigned1;
1909   tree arg0, arg1;
1910   int uns;
1911   tree type;
1912
1913   /* Cast OP0 and OP1 to RESULT_TYPE.  Doing so prevents
1914      excessive narrowing when we call get_narrower below.  For
1915      example, suppose that OP0 is of unsigned int extended
1916      from signed char and that RESULT_TYPE is long long int.
1917      If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
1918      like
1919
1920      (long long int) (unsigned int) signed_char
1921
1922      which get_narrower would narrow down to
1923
1924      (unsigned int) signed char
1925
1926      If we do not cast OP0 first, get_narrower would return
1927      signed_char, which is inconsistent with the case of the
1928      explicit cast.  */
1929   op0 = convert (result_type, op0);
1930   op1 = convert (result_type, op1);
1931
1932   arg0 = get_narrower (op0, &unsigned0);
1933   arg1 = get_narrower (op1, &unsigned1);
1934
1935   /* UNS is 1 if the operation to be done is an unsigned one.  */
1936   uns = TYPE_UNSIGNED (result_type);
1937
1938   /* Handle the case that OP0 (or OP1) does not *contain* a conversion
1939      but it *requires* conversion to FINAL_TYPE.  */
1940
1941   if ((TYPE_PRECISION (TREE_TYPE (op0))
1942        == TYPE_PRECISION (TREE_TYPE (arg0)))
1943       && TREE_TYPE (op0) != result_type)
1944     unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
1945   if ((TYPE_PRECISION (TREE_TYPE (op1))
1946        == TYPE_PRECISION (TREE_TYPE (arg1)))
1947       && TREE_TYPE (op1) != result_type)
1948     unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
1949
1950   /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE.  */
1951
1952   /* For bitwise operations, signedness of nominal type
1953      does not matter.  Consider only how operands were extended.  */
1954   if (bitwise)
1955     uns = unsigned0;
1956
1957   /* Note that in all three cases below we refrain from optimizing
1958      an unsigned operation on sign-extended args.
1959      That would not be valid.  */
1960
1961   /* Both args variable: if both extended in same way
1962      from same width, do it in that width.
1963      Do it unsigned if args were zero-extended.  */
1964   if ((TYPE_PRECISION (TREE_TYPE (arg0))
1965        < TYPE_PRECISION (result_type))
1966       && (TYPE_PRECISION (TREE_TYPE (arg1))
1967           == TYPE_PRECISION (TREE_TYPE (arg0)))
1968       && unsigned0 == unsigned1
1969       && (unsigned0 || !uns))
1970     return c_common_signed_or_unsigned_type
1971       (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
1972
1973   else if (TREE_CODE (arg0) == INTEGER_CST
1974            && (unsigned1 || !uns)
1975            && (TYPE_PRECISION (TREE_TYPE (arg1))
1976                < TYPE_PRECISION (result_type))
1977            && (type
1978                = c_common_signed_or_unsigned_type (unsigned1,
1979                                                    TREE_TYPE (arg1)))
1980            && !POINTER_TYPE_P (type)
1981            && int_fits_type_p (arg0, type))
1982     return type;
1983
1984   else if (TREE_CODE (arg1) == INTEGER_CST
1985            && (unsigned0 || !uns)
1986            && (TYPE_PRECISION (TREE_TYPE (arg0))
1987                < TYPE_PRECISION (result_type))
1988            && (type
1989                = c_common_signed_or_unsigned_type (unsigned0,
1990                                                    TREE_TYPE (arg0)))
1991            && !POINTER_TYPE_P (type)
1992            && int_fits_type_p (arg1, type))
1993     return type;
1994
1995   return result_type;
1996 }
1997
1998 /* Warns if the conversion of EXPR to TYPE may alter a value.
1999    This is a helper function for warnings_for_convert_and_check.  */
2000
2001 static void
2002 conversion_warning (tree type, tree expr)
2003 {
2004   bool give_warning = false;
2005
2006   int i;
2007   const int expr_num_operands = TREE_OPERAND_LENGTH (expr);
2008   tree expr_type = TREE_TYPE (expr);
2009
2010   if (!warn_conversion && !warn_sign_conversion)
2011     return;
2012
2013   /* If any operand is artificial, then this expression was generated
2014      by the compiler and we do not warn.  */
2015   for (i = 0; i < expr_num_operands; i++)
2016     {
2017       tree op = TREE_OPERAND (expr, i);
2018       if (op && DECL_P (op) && DECL_ARTIFICIAL (op))
2019         return;
2020     }
2021
2022   switch (TREE_CODE (expr))
2023     {
2024     case EQ_EXPR:
2025     case NE_EXPR:
2026     case LE_EXPR:
2027     case GE_EXPR:
2028     case LT_EXPR:
2029     case GT_EXPR:
2030     case TRUTH_ANDIF_EXPR:
2031     case TRUTH_ORIF_EXPR:
2032     case TRUTH_AND_EXPR:
2033     case TRUTH_OR_EXPR:
2034     case TRUTH_XOR_EXPR:
2035     case TRUTH_NOT_EXPR:
2036       /* Conversion from boolean to a signed:1 bit-field (which only
2037          can hold the values 0 and -1) doesn't lose information - but
2038          it does change the value.  */
2039       if (TYPE_PRECISION (type) == 1 && !TYPE_UNSIGNED (type))
2040         warning (OPT_Wconversion,
2041                  "conversion to %qT from boolean expression", type);
2042       return;
2043
2044     case REAL_CST:
2045     case INTEGER_CST:
2046
2047       /* Warn for real constant that is not an exact integer converted
2048          to integer type.  */
2049       if (TREE_CODE (expr_type) == REAL_TYPE
2050           && TREE_CODE (type) == INTEGER_TYPE)
2051         {
2052           if (!real_isinteger (TREE_REAL_CST_PTR (expr), TYPE_MODE (expr_type)))
2053             give_warning = true;
2054         }
2055       /* Warn for an integer constant that does not fit into integer type.  */
2056       else if (TREE_CODE (expr_type) == INTEGER_TYPE
2057                && TREE_CODE (type) == INTEGER_TYPE
2058                && !int_fits_type_p (expr, type))
2059         {
2060           if (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (expr_type)
2061               && tree_int_cst_sgn (expr) < 0)
2062             warning (OPT_Wsign_conversion,
2063                      "negative integer implicitly converted to unsigned type");
2064           else if (!TYPE_UNSIGNED (type) && TYPE_UNSIGNED (expr_type))
2065             warning (OPT_Wsign_conversion,  "conversion of unsigned constant "
2066                      "value to negative integer");
2067           else
2068             give_warning = true;
2069         }
2070       else if (TREE_CODE (type) == REAL_TYPE)
2071         {
2072           /* Warn for an integer constant that does not fit into real type.  */
2073           if (TREE_CODE (expr_type) == INTEGER_TYPE)
2074             {
2075               REAL_VALUE_TYPE a = real_value_from_int_cst (0, expr);
2076               if (!exact_real_truncate (TYPE_MODE (type), &a))
2077                 give_warning = true;
2078             }
2079           /* Warn for a real constant that does not fit into a smaller
2080              real type.  */
2081           else if (TREE_CODE (expr_type) == REAL_TYPE
2082                    && TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2083             {
2084               REAL_VALUE_TYPE a = TREE_REAL_CST (expr);
2085               if (!exact_real_truncate (TYPE_MODE (type), &a))
2086                 give_warning = true;
2087             }
2088         }
2089
2090       if (give_warning)
2091         warning (OPT_Wconversion,
2092                  "conversion to %qT alters %qT constant value",
2093                  type, expr_type);
2094
2095       return;
2096
2097     case COND_EXPR:
2098       {
2099         /* In case of COND_EXPR, if both operands are constants or
2100            COND_EXPR, then we do not care about the type of COND_EXPR,
2101            only about the conversion of each operand.  */
2102         tree op1 = TREE_OPERAND (expr, 1);
2103         tree op2 = TREE_OPERAND (expr, 2);
2104
2105         if ((TREE_CODE (op1) == REAL_CST || TREE_CODE (op1) == INTEGER_CST
2106              || TREE_CODE (op1) == COND_EXPR)
2107             && (TREE_CODE (op2) == REAL_CST || TREE_CODE (op2) == INTEGER_CST
2108                 || TREE_CODE (op2) == COND_EXPR))
2109           {
2110             conversion_warning (type, op1);
2111             conversion_warning (type, op2);
2112             return;
2113           }
2114         /* Fall through.  */
2115       }
2116
2117     default: /* 'expr' is not a constant.  */
2118
2119       /* Warn for real types converted to integer types.  */
2120       if (TREE_CODE (expr_type) == REAL_TYPE
2121           && TREE_CODE (type) == INTEGER_TYPE)
2122         give_warning = true;
2123
2124       else if (TREE_CODE (expr_type) == INTEGER_TYPE
2125                && TREE_CODE (type) == INTEGER_TYPE)
2126         {
2127           /* Don't warn about unsigned char y = 0xff, x = (int) y;  */
2128           expr = get_unwidened (expr, 0);
2129           expr_type = TREE_TYPE (expr);
2130
2131           /* Don't warn for short y; short x = ((int)y & 0xff);  */
2132           if (TREE_CODE (expr) == BIT_AND_EXPR
2133                 || TREE_CODE (expr) == BIT_IOR_EXPR
2134               || TREE_CODE (expr) == BIT_XOR_EXPR)
2135             {
2136               /* If both args were extended from a shortest type,
2137                  use that type if that is safe.  */
2138               expr_type = shorten_binary_op (expr_type,
2139                                              TREE_OPERAND (expr, 0),
2140                                              TREE_OPERAND (expr, 1),
2141                                              /* bitwise */1);
2142
2143               if (TREE_CODE (expr) == BIT_AND_EXPR)
2144                 {
2145                   tree op0 = TREE_OPERAND (expr, 0);
2146                   tree op1 = TREE_OPERAND (expr, 1);
2147                   bool unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
2148                   bool unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
2149
2150                   /* If one of the operands is a non-negative constant
2151                      that fits in the target type, then the type of the
2152                      other operand does not matter. */
2153                   if ((TREE_CODE (op0) == INTEGER_CST
2154                        && int_fits_type_p (op0, c_common_signed_type (type))
2155                        && int_fits_type_p (op0, c_common_unsigned_type (type)))
2156                       || (TREE_CODE (op1) == INTEGER_CST
2157                           && int_fits_type_p (op1, c_common_signed_type (type))
2158                           && int_fits_type_p (op1,
2159                                               c_common_unsigned_type (type))))
2160                     return;
2161                   /* If constant is unsigned and fits in the target
2162                      type, then the result will also fit.  */
2163                   else if ((TREE_CODE (op0) == INTEGER_CST
2164                             && unsigned0
2165                             && int_fits_type_p (op0, type))
2166                            || (TREE_CODE (op1) == INTEGER_CST
2167                                && unsigned1
2168                                && int_fits_type_p (op1, type)))
2169                     return;
2170                 }
2171             }
2172           /* Warn for integer types converted to smaller integer types.  */
2173           if (TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2174             give_warning = true;
2175
2176           /* When they are the same width but different signedness,
2177              then the value may change.  */
2178           else if ((TYPE_PRECISION (type) == TYPE_PRECISION (expr_type)
2179                     && TYPE_UNSIGNED (expr_type) != TYPE_UNSIGNED (type))
2180                    /* Even when converted to a bigger type, if the type is
2181                       unsigned but expr is signed, then negative values
2182                       will be changed.  */
2183                    || (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (expr_type)))
2184             warning (OPT_Wsign_conversion, "conversion to %qT from %qT "
2185                      "may change the sign of the result",
2186                      type, expr_type);
2187         }
2188
2189       /* Warn for integer types converted to real types if and only if
2190          all the range of values of the integer type cannot be
2191          represented by the real type.  */
2192       else if (TREE_CODE (expr_type) == INTEGER_TYPE
2193                && TREE_CODE (type) == REAL_TYPE)
2194         {
2195           tree type_low_bound, type_high_bound;
2196           REAL_VALUE_TYPE real_low_bound, real_high_bound;
2197
2198           /* Don't warn about char y = 0xff; float x = (int) y;  */
2199           expr = get_unwidened (expr, 0);
2200           expr_type = TREE_TYPE (expr);
2201
2202           type_low_bound = TYPE_MIN_VALUE (expr_type);
2203           type_high_bound = TYPE_MAX_VALUE (expr_type);
2204           real_low_bound = real_value_from_int_cst (0, type_low_bound);
2205           real_high_bound = real_value_from_int_cst (0, type_high_bound);
2206
2207           if (!exact_real_truncate (TYPE_MODE (type), &real_low_bound)
2208               || !exact_real_truncate (TYPE_MODE (type), &real_high_bound))
2209             give_warning = true;
2210         }
2211
2212       /* Warn for real types converted to smaller real types.  */
2213       else if (TREE_CODE (expr_type) == REAL_TYPE
2214                && TREE_CODE (type) == REAL_TYPE
2215                && TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2216         give_warning = true;
2217
2218
2219       if (give_warning)
2220         warning (OPT_Wconversion,
2221                  "conversion to %qT from %qT may alter its value",
2222                  type, expr_type);
2223     }
2224 }
2225
2226 /* Produce warnings after a conversion. RESULT is the result of
2227    converting EXPR to TYPE.  This is a helper function for
2228    convert_and_check and cp_convert_and_check.  */
2229
2230 void
2231 warnings_for_convert_and_check (tree type, tree expr, tree result)
2232 {
2233   if (TREE_CODE (expr) == INTEGER_CST
2234       && (TREE_CODE (type) == INTEGER_TYPE
2235           || TREE_CODE (type) == ENUMERAL_TYPE)
2236       && !int_fits_type_p (expr, type))
2237     {
2238       /* Do not diagnose overflow in a constant expression merely
2239          because a conversion overflowed.  */
2240       if (TREE_OVERFLOW (result))
2241         TREE_OVERFLOW (result) = TREE_OVERFLOW (expr);
2242
2243       if (TYPE_UNSIGNED (type))
2244         {
2245           /* This detects cases like converting -129 or 256 to
2246              unsigned char.  */
2247           if (!int_fits_type_p (expr, c_common_signed_type (type)))
2248             warning (OPT_Woverflow,
2249                      "large integer implicitly truncated to unsigned type");
2250           else
2251             conversion_warning (type, expr);
2252         }
2253       else if (!int_fits_type_p (expr, c_common_unsigned_type (type)))
2254         warning (OPT_Woverflow,
2255                  "overflow in implicit constant conversion");
2256       /* No warning for converting 0x80000000 to int.  */
2257       else if (pedantic
2258                && (TREE_CODE (TREE_TYPE (expr)) != INTEGER_TYPE
2259                    || TYPE_PRECISION (TREE_TYPE (expr))
2260                    != TYPE_PRECISION (type)))
2261         warning (OPT_Woverflow,
2262                  "overflow in implicit constant conversion");
2263
2264       else
2265         conversion_warning (type, expr);
2266     }
2267   else if ((TREE_CODE (result) == INTEGER_CST
2268             || TREE_CODE (result) == FIXED_CST) && TREE_OVERFLOW (result))
2269     warning (OPT_Woverflow,
2270              "overflow in implicit constant conversion");
2271   else
2272     conversion_warning (type, expr);
2273 }
2274
2275
2276 /* Convert EXPR to TYPE, warning about conversion problems with constants.
2277    Invoke this function on every expression that is converted implicitly,
2278    i.e. because of language rules and not because of an explicit cast.  */
2279
2280 tree
2281 convert_and_check (tree type, tree expr)
2282 {
2283   tree result;
2284   tree expr_for_warning;
2285
2286   /* Convert from a value with possible excess precision rather than
2287      via the semantic type, but do not warn about values not fitting
2288      exactly in the semantic type.  */
2289   if (TREE_CODE (expr) == EXCESS_PRECISION_EXPR)
2290     {
2291       tree orig_type = TREE_TYPE (expr);
2292       expr = TREE_OPERAND (expr, 0);
2293       expr_for_warning = convert (orig_type, expr);
2294       if (orig_type == type)
2295         return expr_for_warning;
2296     }
2297   else
2298     expr_for_warning = expr;
2299
2300   if (TREE_TYPE (expr) == type)
2301     return expr;
2302
2303   result = convert (type, expr);
2304
2305   if (c_inhibit_evaluation_warnings == 0
2306       && !TREE_OVERFLOW_P (expr)
2307       && result != error_mark_node)
2308     warnings_for_convert_and_check (type, expr_for_warning, result);
2309
2310   return result;
2311 }
2312 \f
2313 /* A node in a list that describes references to variables (EXPR), which are
2314    either read accesses if WRITER is zero, or write accesses, in which case
2315    WRITER is the parent of EXPR.  */
2316 struct tlist
2317 {
2318   struct tlist *next;
2319   tree expr, writer;
2320 };
2321
2322 /* Used to implement a cache the results of a call to verify_tree.  We only
2323    use this for SAVE_EXPRs.  */
2324 struct tlist_cache
2325 {
2326   struct tlist_cache *next;
2327   struct tlist *cache_before_sp;
2328   struct tlist *cache_after_sp;
2329   tree expr;
2330 };
2331
2332 /* Obstack to use when allocating tlist structures, and corresponding
2333    firstobj.  */
2334 static struct obstack tlist_obstack;
2335 static char *tlist_firstobj = 0;
2336
2337 /* Keep track of the identifiers we've warned about, so we can avoid duplicate
2338    warnings.  */
2339 static struct tlist *warned_ids;
2340 /* SAVE_EXPRs need special treatment.  We process them only once and then
2341    cache the results.  */
2342 static struct tlist_cache *save_expr_cache;
2343
2344 static void add_tlist (struct tlist **, struct tlist *, tree, int);
2345 static void merge_tlist (struct tlist **, struct tlist *, int);
2346 static void verify_tree (tree, struct tlist **, struct tlist **, tree);
2347 static int warning_candidate_p (tree);
2348 static bool candidate_equal_p (const_tree, const_tree);
2349 static void warn_for_collisions (struct tlist *);
2350 static void warn_for_collisions_1 (tree, tree, struct tlist *, int);
2351 static struct tlist *new_tlist (struct tlist *, tree, tree);
2352
2353 /* Create a new struct tlist and fill in its fields.  */
2354 static struct tlist *
2355 new_tlist (struct tlist *next, tree t, tree writer)
2356 {
2357   struct tlist *l;
2358   l = XOBNEW (&tlist_obstack, struct tlist);
2359   l->next = next;
2360   l->expr = t;
2361   l->writer = writer;
2362   return l;
2363 }
2364
2365 /* Add duplicates of the nodes found in ADD to the list *TO.  If EXCLUDE_WRITER
2366    is nonnull, we ignore any node we find which has a writer equal to it.  */
2367
2368 static void
2369 add_tlist (struct tlist **to, struct tlist *add, tree exclude_writer, int copy)
2370 {
2371   while (add)
2372     {
2373       struct tlist *next = add->next;
2374       if (!copy)
2375         add->next = *to;
2376       if (!exclude_writer || !candidate_equal_p (add->writer, exclude_writer))
2377         *to = copy ? new_tlist (*to, add->expr, add->writer) : add;
2378       add = next;
2379     }
2380 }
2381
2382 /* Merge the nodes of ADD into TO.  This merging process is done so that for
2383    each variable that already exists in TO, no new node is added; however if
2384    there is a write access recorded in ADD, and an occurrence on TO is only
2385    a read access, then the occurrence in TO will be modified to record the
2386    write.  */
2387
2388 static void
2389 merge_tlist (struct tlist **to, struct tlist *add, int copy)
2390 {
2391   struct tlist **end = to;
2392
2393   while (*end)
2394     end = &(*end)->next;
2395
2396   while (add)
2397     {
2398       int found = 0;
2399       struct tlist *tmp2;
2400       struct tlist *next = add->next;
2401
2402       for (tmp2 = *to; tmp2; tmp2 = tmp2->next)
2403         if (candidate_equal_p (tmp2->expr, add->expr))
2404           {
2405             found = 1;
2406             if (!tmp2->writer)
2407               tmp2->writer = add->writer;
2408           }
2409       if (!found)
2410         {
2411           *end = copy ? add : new_tlist (NULL, add->expr, add->writer);
2412           end = &(*end)->next;
2413           *end = 0;
2414         }
2415       add = next;
2416     }
2417 }
2418
2419 /* WRITTEN is a variable, WRITER is its parent.  Warn if any of the variable
2420    references in list LIST conflict with it, excluding reads if ONLY writers
2421    is nonzero.  */
2422
2423 static void
2424 warn_for_collisions_1 (tree written, tree writer, struct tlist *list,
2425                        int only_writes)
2426 {
2427   struct tlist *tmp;
2428
2429   /* Avoid duplicate warnings.  */
2430   for (tmp = warned_ids; tmp; tmp = tmp->next)
2431     if (candidate_equal_p (tmp->expr, written))
2432       return;
2433
2434   while (list)
2435     {
2436       if (candidate_equal_p (list->expr, written)
2437           && !candidate_equal_p (list->writer, writer)
2438           && (!only_writes || list->writer))
2439         {
2440           warned_ids = new_tlist (warned_ids, written, NULL_TREE);
2441           warning_at (EXPR_HAS_LOCATION (writer)
2442                       ? EXPR_LOCATION (writer) : input_location,
2443                       OPT_Wsequence_point, "operation on %qE may be undefined",
2444                       list->expr);
2445         }
2446       list = list->next;
2447     }
2448 }
2449
2450 /* Given a list LIST of references to variables, find whether any of these
2451    can cause conflicts due to missing sequence points.  */
2452
2453 static void
2454 warn_for_collisions (struct tlist *list)
2455 {
2456   struct tlist *tmp;
2457
2458   for (tmp = list; tmp; tmp = tmp->next)
2459     {
2460       if (tmp->writer)
2461         warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0);
2462     }
2463 }
2464
2465 /* Return nonzero if X is a tree that can be verified by the sequence point
2466    warnings.  */
2467 static int
2468 warning_candidate_p (tree x)
2469 {
2470   /* !VOID_TYPE_P (TREE_TYPE (x)) is workaround for cp/tree.c
2471      (lvalue_p) crash on TRY/CATCH. */
2472   return !(DECL_P (x) && DECL_ARTIFICIAL (x))
2473     && TREE_TYPE (x) && !VOID_TYPE_P (TREE_TYPE (x)) && lvalue_p (x);
2474 }
2475
2476 /* Return nonzero if X and Y appear to be the same candidate (or NULL) */
2477 static bool
2478 candidate_equal_p (const_tree x, const_tree y)
2479 {
2480   return (x == y) || (x && y && operand_equal_p (x, y, 0));
2481 }
2482
2483 /* Walk the tree X, and record accesses to variables.  If X is written by the
2484    parent tree, WRITER is the parent.
2485    We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP.  If this
2486    expression or its only operand forces a sequence point, then everything up
2487    to the sequence point is stored in PBEFORE_SP.  Everything else gets stored
2488    in PNO_SP.
2489    Once we return, we will have emitted warnings if any subexpression before
2490    such a sequence point could be undefined.  On a higher level, however, the
2491    sequence point may not be relevant, and we'll merge the two lists.
2492
2493    Example: (b++, a) + b;
2494    The call that processes the COMPOUND_EXPR will store the increment of B
2495    in PBEFORE_SP, and the use of A in PNO_SP.  The higher-level call that
2496    processes the PLUS_EXPR will need to merge the two lists so that
2497    eventually, all accesses end up on the same list (and we'll warn about the
2498    unordered subexpressions b++ and b.
2499
2500    A note on merging.  If we modify the former example so that our expression
2501    becomes
2502      (b++, b) + a
2503    care must be taken not simply to add all three expressions into the final
2504    PNO_SP list.  The function merge_tlist takes care of that by merging the
2505    before-SP list of the COMPOUND_EXPR into its after-SP list in a special
2506    way, so that no more than one access to B is recorded.  */
2507
2508 static void
2509 verify_tree (tree x, struct tlist **pbefore_sp, struct tlist **pno_sp,
2510              tree writer)
2511 {
2512   struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3;
2513   enum tree_code code;
2514   enum tree_code_class cl;
2515
2516   /* X may be NULL if it is the operand of an empty statement expression
2517      ({ }).  */
2518   if (x == NULL)
2519     return;
2520
2521  restart:
2522   code = TREE_CODE (x);
2523   cl = TREE_CODE_CLASS (code);
2524
2525   if (warning_candidate_p (x))
2526     *pno_sp = new_tlist (*pno_sp, x, writer);
2527
2528   switch (code)
2529     {
2530     case CONSTRUCTOR:
2531       return;
2532
2533     case COMPOUND_EXPR:
2534     case TRUTH_ANDIF_EXPR:
2535     case TRUTH_ORIF_EXPR:
2536       tmp_before = tmp_nosp = tmp_list3 = 0;
2537       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
2538       warn_for_collisions (tmp_nosp);
2539       merge_tlist (pbefore_sp, tmp_before, 0);
2540       merge_tlist (pbefore_sp, tmp_nosp, 0);
2541       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE);
2542       merge_tlist (pbefore_sp, tmp_list3, 0);
2543       return;
2544
2545     case COND_EXPR:
2546       tmp_before = tmp_list2 = 0;
2547       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE);
2548       warn_for_collisions (tmp_list2);
2549       merge_tlist (pbefore_sp, tmp_before, 0);
2550       merge_tlist (pbefore_sp, tmp_list2, 1);
2551
2552       tmp_list3 = tmp_nosp = 0;
2553       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE);
2554       warn_for_collisions (tmp_nosp);
2555       merge_tlist (pbefore_sp, tmp_list3, 0);
2556
2557       tmp_list3 = tmp_list2 = 0;
2558       verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE);
2559       warn_for_collisions (tmp_list2);
2560       merge_tlist (pbefore_sp, tmp_list3, 0);
2561       /* Rather than add both tmp_nosp and tmp_list2, we have to merge the
2562          two first, to avoid warning for (a ? b++ : b++).  */
2563       merge_tlist (&tmp_nosp, tmp_list2, 0);
2564       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2565       return;
2566
2567     case PREDECREMENT_EXPR:
2568     case PREINCREMENT_EXPR:
2569     case POSTDECREMENT_EXPR:
2570     case POSTINCREMENT_EXPR:
2571       verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x);
2572       return;
2573
2574     case MODIFY_EXPR:
2575       tmp_before = tmp_nosp = tmp_list3 = 0;
2576       verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE);
2577       verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x);
2578       /* Expressions inside the LHS are not ordered wrt. the sequence points
2579          in the RHS.  Example:
2580            *a = (a++, 2)
2581          Despite the fact that the modification of "a" is in the before_sp
2582          list (tmp_before), it conflicts with the use of "a" in the LHS.
2583          We can handle this by adding the contents of tmp_list3
2584          to those of tmp_before, and redoing the collision warnings for that
2585          list.  */
2586       add_tlist (&tmp_before, tmp_list3, x, 1);
2587       warn_for_collisions (tmp_before);
2588       /* Exclude the LHS itself here; we first have to merge it into the
2589          tmp_nosp list.  This is done to avoid warning for "a = a"; if we
2590          didn't exclude the LHS, we'd get it twice, once as a read and once
2591          as a write.  */
2592       add_tlist (pno_sp, tmp_list3, x, 0);
2593       warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1);
2594
2595       merge_tlist (pbefore_sp, tmp_before, 0);
2596       if (warning_candidate_p (TREE_OPERAND (x, 0)))
2597         merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0);
2598       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1);
2599       return;
2600
2601     case CALL_EXPR:
2602       /* We need to warn about conflicts among arguments and conflicts between
2603          args and the function address.  Side effects of the function address,
2604          however, are not ordered by the sequence point of the call.  */
2605       {
2606         call_expr_arg_iterator iter;
2607         tree arg;
2608         tmp_before = tmp_nosp = 0;
2609         verify_tree (CALL_EXPR_FN (x), &tmp_before, &tmp_nosp, NULL_TREE);
2610         FOR_EACH_CALL_EXPR_ARG (arg, iter, x)
2611           {
2612             tmp_list2 = tmp_list3 = 0;
2613             verify_tree (arg, &tmp_list2, &tmp_list3, NULL_TREE);
2614             merge_tlist (&tmp_list3, tmp_list2, 0);
2615             add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0);
2616           }
2617         add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0);
2618         warn_for_collisions (tmp_before);
2619         add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0);
2620         return;
2621       }
2622
2623     case TREE_LIST:
2624       /* Scan all the list, e.g. indices of multi dimensional array.  */
2625       while (x)
2626         {
2627           tmp_before = tmp_nosp = 0;
2628           verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE);
2629           merge_tlist (&tmp_nosp, tmp_before, 0);
2630           add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2631           x = TREE_CHAIN (x);
2632         }
2633       return;
2634
2635     case SAVE_EXPR:
2636       {
2637         struct tlist_cache *t;
2638         for (t = save_expr_cache; t; t = t->next)
2639           if (candidate_equal_p (t->expr, x))
2640             break;
2641
2642         if (!t)
2643           {
2644             t = XOBNEW (&tlist_obstack, struct tlist_cache);
2645             t->next = save_expr_cache;
2646             t->expr = x;
2647             save_expr_cache = t;
2648
2649             tmp_before = tmp_nosp = 0;
2650             verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
2651             warn_for_collisions (tmp_nosp);
2652
2653             tmp_list3 = 0;
2654             while (tmp_nosp)
2655               {
2656                 struct tlist *t = tmp_nosp;
2657                 tmp_nosp = t->next;
2658                 merge_tlist (&tmp_list3, t, 0);
2659               }
2660             t->cache_before_sp = tmp_before;
2661             t->cache_after_sp = tmp_list3;
2662           }
2663         merge_tlist (pbefore_sp, t->cache_before_sp, 1);
2664         add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1);
2665         return;
2666       }
2667
2668     case ADDR_EXPR:
2669       x = TREE_OPERAND (x, 0);
2670       if (DECL_P (x))
2671         return;
2672       writer = 0;
2673       goto restart;
2674
2675     default:
2676       /* For other expressions, simply recurse on their operands.
2677          Manual tail recursion for unary expressions.
2678          Other non-expressions need not be processed.  */
2679       if (cl == tcc_unary)
2680         {
2681           x = TREE_OPERAND (x, 0);
2682           writer = 0;
2683           goto restart;
2684         }
2685       else if (IS_EXPR_CODE_CLASS (cl))
2686         {
2687           int lp;
2688           int max = TREE_OPERAND_LENGTH (x);
2689           for (lp = 0; lp < max; lp++)
2690             {
2691               tmp_before = tmp_nosp = 0;
2692               verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, 0);
2693               merge_tlist (&tmp_nosp, tmp_before, 0);
2694               add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2695             }
2696         }
2697       return;
2698     }
2699 }
2700
2701 /* Try to warn for undefined behavior in EXPR due to missing sequence
2702    points.  */
2703
2704 void
2705 verify_sequence_points (tree expr)
2706 {
2707   struct tlist *before_sp = 0, *after_sp = 0;
2708
2709   warned_ids = 0;
2710   save_expr_cache = 0;
2711   if (tlist_firstobj == 0)
2712     {
2713       gcc_obstack_init (&tlist_obstack);
2714       tlist_firstobj = (char *) obstack_alloc (&tlist_obstack, 0);
2715     }
2716
2717   verify_tree (expr, &before_sp, &after_sp, 0);
2718   warn_for_collisions (after_sp);
2719   obstack_free (&tlist_obstack, tlist_firstobj);
2720 }
2721 \f
2722 /* Validate the expression after `case' and apply default promotions.  */
2723
2724 static tree
2725 check_case_value (tree value)
2726 {
2727   if (value == NULL_TREE)
2728     return value;
2729
2730   /* ??? Can we ever get nops here for a valid case value?  We
2731      shouldn't for C.  */
2732   STRIP_TYPE_NOPS (value);
2733   /* In C++, the following is allowed:
2734
2735        const int i = 3;
2736        switch (...) { case i: ... }
2737
2738      So, we try to reduce the VALUE to a constant that way.  */
2739   if (c_dialect_cxx ())
2740     {
2741       value = decl_constant_value (value);
2742       STRIP_TYPE_NOPS (value);
2743       value = fold (value);
2744     }
2745
2746   if (TREE_CODE (value) == INTEGER_CST)
2747     /* Promote char or short to int.  */
2748     value = perform_integral_promotions (value);
2749   else if (value != error_mark_node)
2750     {
2751       error ("case label does not reduce to an integer constant");
2752       value = error_mark_node;
2753     }
2754
2755   constant_expression_warning (value);
2756
2757   return value;
2758 }
2759 \f
2760 /* See if the case values LOW and HIGH are in the range of the original
2761    type (i.e. before the default conversion to int) of the switch testing
2762    expression.
2763    TYPE is the promoted type of the testing expression, and ORIG_TYPE is
2764    the type before promoting it.  CASE_LOW_P is a pointer to the lower
2765    bound of the case label, and CASE_HIGH_P is the upper bound or NULL
2766    if the case is not a case range.
2767    The caller has to make sure that we are not called with NULL for
2768    CASE_LOW_P (i.e. the default case).
2769    Returns true if the case label is in range of ORIG_TYPE (saturated or
2770    untouched) or false if the label is out of range.  */
2771
2772 static bool
2773 check_case_bounds (tree type, tree orig_type,
2774                    tree *case_low_p, tree *case_high_p)
2775 {
2776   tree min_value, max_value;
2777   tree case_low = *case_low_p;
2778   tree case_high = case_high_p ? *case_high_p : case_low;
2779
2780   /* If there was a problem with the original type, do nothing.  */
2781   if (orig_type == error_mark_node)
2782     return true;
2783
2784   min_value = TYPE_MIN_VALUE (orig_type);
2785   max_value = TYPE_MAX_VALUE (orig_type);
2786
2787   /* Case label is less than minimum for type.  */
2788   if (tree_int_cst_compare (case_low, min_value) < 0
2789       && tree_int_cst_compare (case_high, min_value) < 0)
2790     {
2791       warning (0, "case label value is less than minimum value for type");
2792       return false;
2793     }
2794
2795   /* Case value is greater than maximum for type.  */
2796   if (tree_int_cst_compare (case_low, max_value) > 0
2797       && tree_int_cst_compare (case_high, max_value) > 0)
2798     {
2799       warning (0, "case label value exceeds maximum value for type");
2800       return false;
2801     }
2802
2803   /* Saturate lower case label value to minimum.  */
2804   if (tree_int_cst_compare (case_high, min_value) >= 0
2805       && tree_int_cst_compare (case_low, min_value) < 0)
2806     {
2807       warning (0, "lower value in case label range"
2808                " less than minimum value for type");
2809       case_low = min_value;
2810     }
2811
2812   /* Saturate upper case label value to maximum.  */
2813   if (tree_int_cst_compare (case_low, max_value) <= 0
2814       && tree_int_cst_compare (case_high, max_value) > 0)
2815     {
2816       warning (0, "upper value in case label range"
2817                " exceeds maximum value for type");
2818       case_high = max_value;
2819     }
2820
2821   if (*case_low_p != case_low)
2822     *case_low_p = convert (type, case_low);
2823   if (case_high_p && *case_high_p != case_high)
2824     *case_high_p = convert (type, case_high);
2825
2826   return true;
2827 }
2828 \f
2829 /* Return an integer type with BITS bits of precision,
2830    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
2831
2832 tree
2833 c_common_type_for_size (unsigned int bits, int unsignedp)
2834 {
2835   if (bits == TYPE_PRECISION (integer_type_node))
2836     return unsignedp ? unsigned_type_node : integer_type_node;
2837
2838   if (bits == TYPE_PRECISION (signed_char_type_node))
2839     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2840
2841   if (bits == TYPE_PRECISION (short_integer_type_node))
2842     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2843
2844   if (bits == TYPE_PRECISION (long_integer_type_node))
2845     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2846
2847   if (bits == TYPE_PRECISION (long_long_integer_type_node))
2848     return (unsignedp ? long_long_unsigned_type_node
2849             : long_long_integer_type_node);
2850
2851   if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
2852     return (unsignedp ? widest_unsigned_literal_type_node
2853             : widest_integer_literal_type_node);
2854
2855   if (bits <= TYPE_PRECISION (intQI_type_node))
2856     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2857
2858   if (bits <= TYPE_PRECISION (intHI_type_node))
2859     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2860
2861   if (bits <= TYPE_PRECISION (intSI_type_node))
2862     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2863
2864   if (bits <= TYPE_PRECISION (intDI_type_node))
2865     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2866
2867   return 0;
2868 }
2869
2870 /* Return a fixed-point type that has at least IBIT ibits and FBIT fbits
2871    that is unsigned if UNSIGNEDP is nonzero, otherwise signed;
2872    and saturating if SATP is nonzero, otherwise not saturating.  */
2873
2874 tree
2875 c_common_fixed_point_type_for_size (unsigned int ibit, unsigned int fbit,
2876                                     int unsignedp, int satp)
2877 {
2878   enum machine_mode mode;
2879   if (ibit == 0)
2880     mode = unsignedp ? UQQmode : QQmode;
2881   else
2882     mode = unsignedp ? UHAmode : HAmode;
2883
2884   for (; mode != VOIDmode; mode = GET_MODE_WIDER_MODE (mode))
2885     if (GET_MODE_IBIT (mode) >= ibit && GET_MODE_FBIT (mode) >= fbit)
2886       break;
2887
2888   if (mode == VOIDmode || !targetm.scalar_mode_supported_p (mode))
2889     {
2890       sorry ("GCC cannot support operators with integer types and "
2891              "fixed-point types that have too many integral and "
2892              "fractional bits together");
2893       return 0;
2894     }
2895
2896   return c_common_type_for_mode (mode, satp);
2897 }
2898
2899 /* Used for communication between c_common_type_for_mode and
2900    c_register_builtin_type.  */
2901 static GTY(()) tree registered_builtin_types;
2902
2903 /* Return a data type that has machine mode MODE.
2904    If the mode is an integer,
2905    then UNSIGNEDP selects between signed and unsigned types.
2906    If the mode is a fixed-point mode,
2907    then UNSIGNEDP selects between saturating and nonsaturating types.  */
2908
2909 tree
2910 c_common_type_for_mode (enum machine_mode mode, int unsignedp)
2911 {
2912   tree t;
2913
2914   if (mode == TYPE_MODE (integer_type_node))
2915     return unsignedp ? unsigned_type_node : integer_type_node;
2916
2917   if (mode == TYPE_MODE (signed_char_type_node))
2918     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2919
2920   if (mode == TYPE_MODE (short_integer_type_node))
2921     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2922
2923   if (mode == TYPE_MODE (long_integer_type_node))
2924     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2925
2926   if (mode == TYPE_MODE (long_long_integer_type_node))
2927     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
2928
2929   if (mode == TYPE_MODE (widest_integer_literal_type_node))
2930     return unsignedp ? widest_unsigned_literal_type_node
2931                      : widest_integer_literal_type_node;
2932
2933   if (mode == QImode)
2934     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2935
2936   if (mode == HImode)
2937     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2938
2939   if (mode == SImode)
2940     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2941
2942   if (mode == DImode)
2943     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2944
2945 #if HOST_BITS_PER_WIDE_INT >= 64
2946   if (mode == TYPE_MODE (intTI_type_node))
2947     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
2948 #endif
2949
2950   if (mode == TYPE_MODE (float_type_node))
2951     return float_type_node;
2952
2953   if (mode == TYPE_MODE (double_type_node))
2954     return double_type_node;
2955
2956   if (mode == TYPE_MODE (long_double_type_node))
2957     return long_double_type_node;
2958
2959   if (mode == TYPE_MODE (void_type_node))
2960     return void_type_node;
2961
2962   if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
2963     return (unsignedp
2964             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2965             : make_signed_type (GET_MODE_PRECISION (mode)));
2966
2967   if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
2968     return (unsignedp
2969             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2970             : make_signed_type (GET_MODE_PRECISION (mode)));
2971
2972   if (COMPLEX_MODE_P (mode))
2973     {
2974       enum machine_mode inner_mode;
2975       tree inner_type;
2976
2977       if (mode == TYPE_MODE (complex_float_type_node))
2978         return complex_float_type_node;
2979       if (mode == TYPE_MODE (complex_double_type_node))
2980         return complex_double_type_node;
2981       if (mode == TYPE_MODE (complex_long_double_type_node))
2982         return complex_long_double_type_node;
2983
2984       if (mode == TYPE_MODE (complex_integer_type_node) && !unsignedp)
2985         return complex_integer_type_node;
2986
2987       inner_mode = GET_MODE_INNER (mode);
2988       inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2989       if (inner_type != NULL_TREE)
2990         return build_complex_type (inner_type);
2991     }
2992   else if (VECTOR_MODE_P (mode))
2993     {
2994       enum machine_mode inner_mode = GET_MODE_INNER (mode);
2995       tree inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2996       if (inner_type != NULL_TREE)
2997         return build_vector_type_for_mode (inner_type, mode);
2998     }
2999
3000   if (mode == TYPE_MODE (dfloat32_type_node))
3001     return dfloat32_type_node;
3002   if (mode == TYPE_MODE (dfloat64_type_node))
3003     return dfloat64_type_node;
3004   if (mode == TYPE_MODE (dfloat128_type_node))
3005     return dfloat128_type_node;
3006
3007   if (ALL_SCALAR_FIXED_POINT_MODE_P (mode))
3008     {
3009       if (mode == TYPE_MODE (short_fract_type_node))
3010         return unsignedp ? sat_short_fract_type_node : short_fract_type_node;
3011       if (mode == TYPE_MODE (fract_type_node))
3012         return unsignedp ? sat_fract_type_node : fract_type_node;
3013       if (mode == TYPE_MODE (long_fract_type_node))
3014         return unsignedp ? sat_long_fract_type_node : long_fract_type_node;
3015       if (mode == TYPE_MODE (long_long_fract_type_node))
3016         return unsignedp ? sat_long_long_fract_type_node
3017                          : long_long_fract_type_node;
3018
3019       if (mode == TYPE_MODE (unsigned_short_fract_type_node))
3020         return unsignedp ? sat_unsigned_short_fract_type_node
3021                          : unsigned_short_fract_type_node;
3022       if (mode == TYPE_MODE (unsigned_fract_type_node))
3023         return unsignedp ? sat_unsigned_fract_type_node
3024                          : unsigned_fract_type_node;
3025       if (mode == TYPE_MODE (unsigned_long_fract_type_node))
3026         return unsignedp ? sat_unsigned_long_fract_type_node
3027                          : unsigned_long_fract_type_node;
3028       if (mode == TYPE_MODE (unsigned_long_long_fract_type_node))
3029         return unsignedp ? sat_unsigned_long_long_fract_type_node
3030                          : unsigned_long_long_fract_type_node;
3031
3032       if (mode == TYPE_MODE (short_accum_type_node))
3033         return unsignedp ? sat_short_accum_type_node : short_accum_type_node;
3034       if (mode == TYPE_MODE (accum_type_node))
3035         return unsignedp ? sat_accum_type_node : accum_type_node;
3036       if (mode == TYPE_MODE (long_accum_type_node))
3037         return unsignedp ? sat_long_accum_type_node : long_accum_type_node;
3038       if (mode == TYPE_MODE (long_long_accum_type_node))
3039         return unsignedp ? sat_long_long_accum_type_node
3040                          : long_long_accum_type_node;
3041
3042       if (mode == TYPE_MODE (unsigned_short_accum_type_node))
3043         return unsignedp ? sat_unsigned_short_accum_type_node
3044                          : unsigned_short_accum_type_node;
3045       if (mode == TYPE_MODE (unsigned_accum_type_node))
3046         return unsignedp ? sat_unsigned_accum_type_node
3047                          : unsigned_accum_type_node;
3048       if (mode == TYPE_MODE (unsigned_long_accum_type_node))
3049         return unsignedp ? sat_unsigned_long_accum_type_node
3050                          : unsigned_long_accum_type_node;
3051       if (mode == TYPE_MODE (unsigned_long_long_accum_type_node))
3052         return unsignedp ? sat_unsigned_long_long_accum_type_node
3053                          : unsigned_long_long_accum_type_node;
3054
3055       if (mode == QQmode)
3056         return unsignedp ? sat_qq_type_node : qq_type_node;
3057       if (mode == HQmode)
3058         return unsignedp ? sat_hq_type_node : hq_type_node;
3059       if (mode == SQmode)
3060         return unsignedp ? sat_sq_type_node : sq_type_node;
3061       if (mode == DQmode)
3062         return unsignedp ? sat_dq_type_node : dq_type_node;
3063       if (mode == TQmode)
3064         return unsignedp ? sat_tq_type_node : tq_type_node;
3065
3066       if (mode == UQQmode)
3067         return unsignedp ? sat_uqq_type_node : uqq_type_node;
3068       if (mode == UHQmode)
3069         return unsignedp ? sat_uhq_type_node : uhq_type_node;
3070       if (mode == USQmode)
3071         return unsignedp ? sat_usq_type_node : usq_type_node;
3072       if (mode == UDQmode)
3073         return unsignedp ? sat_udq_type_node : udq_type_node;
3074       if (mode == UTQmode)
3075         return unsignedp ? sat_utq_type_node : utq_type_node;
3076
3077       if (mode == HAmode)
3078         return unsignedp ? sat_ha_type_node : ha_type_node;
3079       if (mode == SAmode)
3080         return unsignedp ? sat_sa_type_node : sa_type_node;
3081       if (mode == DAmode)
3082         return unsignedp ? sat_da_type_node : da_type_node;
3083       if (mode == TAmode)
3084         return unsignedp ? sat_ta_type_node : ta_type_node;
3085
3086       if (mode == UHAmode)
3087         return unsignedp ? sat_uha_type_node : uha_type_node;
3088       if (mode == USAmode)
3089         return unsignedp ? sat_usa_type_node : usa_type_node;
3090       if (mode == UDAmode)
3091         return unsignedp ? sat_uda_type_node : uda_type_node;
3092       if (mode == UTAmode)
3093         return unsignedp ? sat_uta_type_node : uta_type_node;
3094     }
3095
3096   for (t = registered_builtin_types; t; t = TREE_CHAIN (t))
3097     if (TYPE_MODE (TREE_VALUE (t)) == mode)
3098       return TREE_VALUE (t);
3099
3100   return 0;
3101 }
3102
3103 tree
3104 c_common_unsigned_type (tree type)
3105 {
3106   return c_common_signed_or_unsigned_type (1, type);
3107 }
3108
3109 /* Return a signed type the same as TYPE in other respects.  */
3110
3111 tree
3112 c_common_signed_type (tree type)
3113 {
3114   return c_common_signed_or_unsigned_type (0, type);
3115 }
3116
3117 /* Return a type the same as TYPE except unsigned or
3118    signed according to UNSIGNEDP.  */
3119
3120 tree
3121 c_common_signed_or_unsigned_type (int unsignedp, tree type)
3122 {
3123   tree type1;
3124
3125   /* This block of code emulates the behavior of the old
3126      c_common_unsigned_type. In particular, it returns
3127      long_unsigned_type_node if passed a long, even when a int would
3128      have the same size. This is necessary for warnings to work
3129      correctly in archs where sizeof(int) == sizeof(long) */
3130
3131   type1 = TYPE_MAIN_VARIANT (type);
3132   if (type1 == signed_char_type_node || type1 == char_type_node || type1 == unsigned_char_type_node)
3133     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3134   if (type1 == integer_type_node || type1 == unsigned_type_node)
3135     return unsignedp ? unsigned_type_node : integer_type_node;
3136   if (type1 == short_integer_type_node || type1 == short_unsigned_type_node)
3137     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3138   if (type1 == long_integer_type_node || type1 == long_unsigned_type_node)
3139     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3140   if (type1 == long_long_integer_type_node || type1 == long_long_unsigned_type_node)
3141     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
3142   if (type1 == widest_integer_literal_type_node || type1 == widest_unsigned_literal_type_node)
3143     return unsignedp ? widest_unsigned_literal_type_node : widest_integer_literal_type_node;
3144 #if HOST_BITS_PER_WIDE_INT >= 64
3145   if (type1 == intTI_type_node || type1 == unsigned_intTI_type_node)
3146     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
3147 #endif
3148   if (type1 == intDI_type_node || type1 == unsigned_intDI_type_node)
3149     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
3150   if (type1 == intSI_type_node || type1 == unsigned_intSI_type_node)
3151     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
3152   if (type1 == intHI_type_node || type1 == unsigned_intHI_type_node)
3153     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
3154   if (type1 == intQI_type_node || type1 == unsigned_intQI_type_node)
3155     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
3156
3157 #define C_COMMON_FIXED_TYPES(NAME)          \
3158   if (type1 == short_ ## NAME ## _type_node \
3159       || type1 == unsigned_short_ ## NAME ## _type_node) \
3160     return unsignedp ? unsigned_short_ ## NAME ## _type_node \
3161                      : short_ ## NAME ## _type_node; \
3162   if (type1 == NAME ## _type_node \
3163       || type1 == unsigned_ ## NAME ## _type_node) \
3164     return unsignedp ? unsigned_ ## NAME ## _type_node \
3165                      : NAME ## _type_node; \
3166   if (type1 == long_ ## NAME ## _type_node \
3167       || type1 == unsigned_long_ ## NAME ## _type_node) \
3168     return unsignedp ? unsigned_long_ ## NAME ## _type_node \
3169                      : long_ ## NAME ## _type_node; \
3170   if (type1 == long_long_ ## NAME ## _type_node \
3171       || type1 == unsigned_long_long_ ## NAME ## _type_node) \
3172     return unsignedp ? unsigned_long_long_ ## NAME ## _type_node \
3173                      : long_long_ ## NAME ## _type_node;
3174
3175 #define C_COMMON_FIXED_MODE_TYPES(NAME) \
3176   if (type1 == NAME ## _type_node \
3177       || type1 == u ## NAME ## _type_node) \
3178     return unsignedp ? u ## NAME ## _type_node \
3179                      : NAME ## _type_node;
3180
3181 #define C_COMMON_FIXED_TYPES_SAT(NAME) \
3182   if (type1 == sat_ ## short_ ## NAME ## _type_node \
3183       || type1 == sat_ ## unsigned_short_ ## NAME ## _type_node) \
3184     return unsignedp ? sat_ ## unsigned_short_ ## NAME ## _type_node \
3185                      : sat_ ## short_ ## NAME ## _type_node; \
3186   if (type1 == sat_ ## NAME ## _type_node \
3187       || type1 == sat_ ## unsigned_ ## NAME ## _type_node) \
3188     return unsignedp ? sat_ ## unsigned_ ## NAME ## _type_node \
3189                      : sat_ ## NAME ## _type_node; \
3190   if (type1 == sat_ ## long_ ## NAME ## _type_node \
3191       || type1 == sat_ ## unsigned_long_ ## NAME ## _type_node) \
3192     return unsignedp ? sat_ ## unsigned_long_ ## NAME ## _type_node \
3193                      : sat_ ## long_ ## NAME ## _type_node; \
3194   if (type1 == sat_ ## long_long_ ## NAME ## _type_node \
3195       || type1 == sat_ ## unsigned_long_long_ ## NAME ## _type_node) \
3196     return unsignedp ? sat_ ## unsigned_long_long_ ## NAME ## _type_node \
3197                      : sat_ ## long_long_ ## NAME ## _type_node;
3198
3199 #define C_COMMON_FIXED_MODE_TYPES_SAT(NAME)     \
3200   if (type1 == sat_ ## NAME ## _type_node \
3201       || type1 == sat_ ## u ## NAME ## _type_node) \
3202     return unsignedp ? sat_ ## u ## NAME ## _type_node \
3203                      : sat_ ## NAME ## _type_node;
3204
3205   C_COMMON_FIXED_TYPES (fract);
3206   C_COMMON_FIXED_TYPES_SAT (fract);
3207   C_COMMON_FIXED_TYPES (accum);
3208   C_COMMON_FIXED_TYPES_SAT (accum);
3209
3210   C_COMMON_FIXED_MODE_TYPES (qq);
3211   C_COMMON_FIXED_MODE_TYPES (hq);
3212   C_COMMON_FIXED_MODE_TYPES (sq);
3213   C_COMMON_FIXED_MODE_TYPES (dq);
3214   C_COMMON_FIXED_MODE_TYPES (tq);
3215   C_COMMON_FIXED_MODE_TYPES_SAT (qq);
3216   C_COMMON_FIXED_MODE_TYPES_SAT (hq);
3217   C_COMMON_FIXED_MODE_TYPES_SAT (sq);
3218   C_COMMON_FIXED_MODE_TYPES_SAT (dq);
3219   C_COMMON_FIXED_MODE_TYPES_SAT (tq);
3220   C_COMMON_FIXED_MODE_TYPES (ha);
3221   C_COMMON_FIXED_MODE_TYPES (sa);
3222   C_COMMON_FIXED_MODE_TYPES (da);
3223   C_COMMON_FIXED_MODE_TYPES (ta);
3224   C_COMMON_FIXED_MODE_TYPES_SAT (ha);
3225   C_COMMON_FIXED_MODE_TYPES_SAT (sa);
3226   C_COMMON_FIXED_MODE_TYPES_SAT (da);
3227   C_COMMON_FIXED_MODE_TYPES_SAT (ta);
3228
3229   /* For ENUMERAL_TYPEs in C++, must check the mode of the types, not
3230      the precision; they have precision set to match their range, but
3231      may use a wider mode to match an ABI.  If we change modes, we may
3232      wind up with bad conversions.  For INTEGER_TYPEs in C, must check
3233      the precision as well, so as to yield correct results for
3234      bit-field types.  C++ does not have these separate bit-field
3235      types, and producing a signed or unsigned variant of an
3236      ENUMERAL_TYPE may cause other problems as well.  */
3237
3238   if (!INTEGRAL_TYPE_P (type)
3239       || TYPE_UNSIGNED (type) == unsignedp)
3240     return type;
3241
3242 #define TYPE_OK(node)                                                       \
3243   (TYPE_MODE (type) == TYPE_MODE (node)                                     \
3244    && TYPE_PRECISION (type) == TYPE_PRECISION (node))
3245   if (TYPE_OK (signed_char_type_node))
3246     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3247   if (TYPE_OK (integer_type_node))
3248     return unsignedp ? unsigned_type_node : integer_type_node;
3249   if (TYPE_OK (short_integer_type_node))
3250     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3251   if (TYPE_OK (long_integer_type_node))
3252     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3253   if (TYPE_OK (long_long_integer_type_node))
3254     return (unsignedp ? long_long_unsigned_type_node
3255             : long_long_integer_type_node);
3256   if (TYPE_OK (widest_integer_literal_type_node))
3257     return (unsignedp ? widest_unsigned_literal_type_node
3258             : widest_integer_literal_type_node);
3259
3260 #if HOST_BITS_PER_WIDE_INT >= 64
3261   if (TYPE_OK (intTI_type_node))
3262     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
3263 #endif
3264   if (TYPE_OK (intDI_type_node))
3265     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
3266   if (TYPE_OK (intSI_type_node))
3267     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
3268   if (TYPE_OK (intHI_type_node))
3269     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
3270   if (TYPE_OK (intQI_type_node))
3271     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
3272 #undef TYPE_OK
3273
3274   return build_nonstandard_integer_type (TYPE_PRECISION (type), unsignedp);
3275 }
3276
3277 /* Build a bit-field integer type for the given WIDTH and UNSIGNEDP.  */
3278
3279 tree
3280 c_build_bitfield_integer_type (unsigned HOST_WIDE_INT width, int unsignedp)
3281 {
3282   /* Extended integer types of the same width as a standard type have
3283      lesser rank, so those of the same width as int promote to int or
3284      unsigned int and are valid for printf formats expecting int or
3285      unsigned int.  To avoid such special cases, avoid creating
3286      extended integer types for bit-fields if a standard integer type
3287      is available.  */
3288   if (width == TYPE_PRECISION (integer_type_node))
3289     return unsignedp ? unsigned_type_node : integer_type_node;
3290   if (width == TYPE_PRECISION (signed_char_type_node))
3291     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3292   if (width == TYPE_PRECISION (short_integer_type_node))
3293     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3294   if (width == TYPE_PRECISION (long_integer_type_node))
3295     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3296   if (width == TYPE_PRECISION (long_long_integer_type_node))
3297     return (unsignedp ? long_long_unsigned_type_node
3298             : long_long_integer_type_node);
3299   return build_nonstandard_integer_type (width, unsignedp);
3300 }
3301
3302 /* The C version of the register_builtin_type langhook.  */
3303
3304 void
3305 c_register_builtin_type (tree type, const char* name)
3306 {
3307   tree decl;
3308
3309   decl = build_decl (UNKNOWN_LOCATION,
3310                      TYPE_DECL, get_identifier (name), type);
3311   DECL_ARTIFICIAL (decl) = 1;
3312   if (!TYPE_NAME (type))
3313     TYPE_NAME (type) = decl;
3314   pushdecl (decl);
3315
3316   registered_builtin_types = tree_cons (0, type, registered_builtin_types);
3317 }
3318 \f
3319 /* Print an error message for invalid operands to arith operation
3320    CODE with TYPE0 for operand 0, and TYPE1 for operand 1.
3321    LOCATION is the location of the message.  */
3322
3323 void
3324 binary_op_error (location_t location, enum tree_code code,
3325                  tree type0, tree type1)
3326 {
3327   const char *opname;
3328
3329   switch (code)
3330     {
3331     case PLUS_EXPR:
3332       opname = "+"; break;
3333     case MINUS_EXPR:
3334       opname = "-"; break;
3335     case MULT_EXPR:
3336       opname = "*"; break;
3337     case MAX_EXPR:
3338       opname = "max"; break;
3339     case MIN_EXPR:
3340       opname = "min"; break;
3341     case EQ_EXPR:
3342       opname = "=="; break;
3343     case NE_EXPR:
3344       opname = "!="; break;
3345     case LE_EXPR:
3346       opname = "<="; break;
3347     case GE_EXPR:
3348       opname = ">="; break;
3349     case LT_EXPR:
3350       opname = "<"; break;
3351     case GT_EXPR:
3352       opname = ">"; break;
3353     case LSHIFT_EXPR:
3354       opname = "<<"; break;
3355     case RSHIFT_EXPR:
3356       opname = ">>"; break;
3357     case TRUNC_MOD_EXPR:
3358     case FLOOR_MOD_EXPR:
3359       opname = "%"; break;
3360     case TRUNC_DIV_EXPR:
3361     case FLOOR_DIV_EXPR:
3362       opname = "/"; break;
3363     case BIT_AND_EXPR:
3364       opname = "&"; break;
3365     case BIT_IOR_EXPR:
3366       opname = "|"; break;
3367     case TRUTH_ANDIF_EXPR:
3368       opname = "&&"; break;
3369     case TRUTH_ORIF_EXPR:
3370       opname = "||"; break;
3371     case BIT_XOR_EXPR:
3372       opname = "^"; break;
3373     default:
3374       gcc_unreachable ();
3375     }
3376   error_at (location,
3377             "invalid operands to binary %s (have %qT and %qT)", opname,
3378             type0, type1);
3379 }
3380 \f
3381 /* Subroutine of build_binary_op, used for comparison operations.
3382    See if the operands have both been converted from subword integer types
3383    and, if so, perhaps change them both back to their original type.
3384    This function is also responsible for converting the two operands
3385    to the proper common type for comparison.
3386
3387    The arguments of this function are all pointers to local variables
3388    of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
3389    RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.
3390
3391    If this function returns nonzero, it means that the comparison has
3392    a constant value.  What this function returns is an expression for
3393    that value.  */
3394
3395 tree
3396 shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr,
3397                  enum tree_code *rescode_ptr)
3398 {
3399   tree type;
3400   tree op0 = *op0_ptr;
3401   tree op1 = *op1_ptr;
3402   int unsignedp0, unsignedp1;
3403   int real1, real2;
3404   tree primop0, primop1;
3405   enum tree_code code = *rescode_ptr;
3406
3407   /* Throw away any conversions to wider types
3408      already present in the operands.  */
3409
3410   primop0 = get_narrower (op0, &unsignedp0);
3411   primop1 = get_narrower (op1, &unsignedp1);
3412
3413   /* Handle the case that OP0 does not *contain* a conversion
3414      but it *requires* conversion to FINAL_TYPE.  */
3415
3416   if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
3417     unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3418   if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
3419     unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3420
3421   /* If one of the operands must be floated, we cannot optimize.  */
3422   real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
3423   real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
3424
3425   /* If first arg is constant, swap the args (changing operation
3426      so value is preserved), for canonicalization.  Don't do this if
3427      the second arg is 0.  */
3428
3429   if (TREE_CONSTANT (primop0)
3430       && !integer_zerop (primop1) && !real_zerop (primop1)
3431       && !fixed_zerop (primop1))
3432     {
3433       tree tem = primop0;
3434       int temi = unsignedp0;
3435       primop0 = primop1;
3436       primop1 = tem;
3437       tem = op0;
3438       op0 = op1;
3439       op1 = tem;
3440       *op0_ptr = op0;
3441       *op1_ptr = op1;
3442       unsignedp0 = unsignedp1;
3443       unsignedp1 = temi;
3444       temi = real1;
3445       real1 = real2;
3446       real2 = temi;
3447
3448       switch (code)
3449         {
3450         case LT_EXPR:
3451           code = GT_EXPR;
3452           break;
3453         case GT_EXPR:
3454           code = LT_EXPR;
3455           break;
3456         case LE_EXPR:
3457           code = GE_EXPR;
3458           break;
3459         case GE_EXPR:
3460           code = LE_EXPR;
3461           break;
3462         default:
3463           break;
3464         }
3465       *rescode_ptr = code;
3466     }
3467
3468   /* If comparing an integer against a constant more bits wide,
3469      maybe we can deduce a value of 1 or 0 independent of the data.
3470      Or else truncate the constant now
3471      rather than extend the variable at run time.
3472
3473      This is only interesting if the constant is the wider arg.
3474      Also, it is not safe if the constant is unsigned and the
3475      variable arg is signed, since in this case the variable
3476      would be sign-extended and then regarded as unsigned.
3477      Our technique fails in this case because the lowest/highest
3478      possible unsigned results don't follow naturally from the
3479      lowest/highest possible values of the variable operand.
3480      For just EQ_EXPR and NE_EXPR there is another technique that
3481      could be used: see if the constant can be faithfully represented
3482      in the other operand's type, by truncating it and reextending it
3483      and see if that preserves the constant's value.  */
3484
3485   if (!real1 && !real2
3486       && TREE_CODE (TREE_TYPE (primop0)) != FIXED_POINT_TYPE
3487       && TREE_CODE (primop1) == INTEGER_CST
3488       && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
3489     {
3490       int min_gt, max_gt, min_lt, max_lt;
3491       tree maxval, minval;
3492       /* 1 if comparison is nominally unsigned.  */
3493       int unsignedp = TYPE_UNSIGNED (*restype_ptr);
3494       tree val;
3495
3496       type = c_common_signed_or_unsigned_type (unsignedp0,
3497                                                TREE_TYPE (primop0));
3498
3499       maxval = TYPE_MAX_VALUE (type);
3500       minval = TYPE_MIN_VALUE (type);
3501
3502       if (unsignedp && !unsignedp0)
3503         *restype_ptr = c_common_signed_type (*restype_ptr);
3504
3505       if (TREE_TYPE (primop1) != *restype_ptr)
3506         {
3507           /* Convert primop1 to target type, but do not introduce
3508              additional overflow.  We know primop1 is an int_cst.  */
3509           primop1 = force_fit_type_double (*restype_ptr,
3510                                            TREE_INT_CST_LOW (primop1),
3511                                            TREE_INT_CST_HIGH (primop1), 0,
3512                                            TREE_OVERFLOW (primop1));
3513         }
3514       if (type != *restype_ptr)
3515         {
3516           minval = convert (*restype_ptr, minval);
3517           maxval = convert (*restype_ptr, maxval);
3518         }
3519
3520       if (unsignedp && unsignedp0)
3521         {
3522           min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
3523           max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
3524           min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
3525           max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
3526         }
3527       else
3528         {
3529           min_gt = INT_CST_LT (primop1, minval);
3530           max_gt = INT_CST_LT (primop1, maxval);
3531           min_lt = INT_CST_LT (minval, primop1);
3532           max_lt = INT_CST_LT (maxval, primop1);
3533         }
3534
3535       val = 0;
3536       /* This used to be a switch, but Genix compiler can't handle that.  */
3537       if (code == NE_EXPR)
3538         {
3539           if (max_lt || min_gt)
3540             val = truthvalue_true_node;
3541         }
3542       else if (code == EQ_EXPR)
3543         {
3544           if (max_lt || min_gt)
3545             val = truthvalue_false_node;
3546         }
3547       else if (code == LT_EXPR)
3548         {
3549           if (max_lt)
3550             val = truthvalue_true_node;
3551           if (!min_lt)
3552             val = truthvalue_false_node;
3553         }
3554       else if (code == GT_EXPR)
3555         {
3556           if (min_gt)
3557             val = truthvalue_true_node;
3558           if (!max_gt)
3559             val = truthvalue_false_node;
3560         }
3561       else if (code == LE_EXPR)
3562         {
3563           if (!max_gt)
3564             val = truthvalue_true_node;
3565           if (min_gt)
3566             val = truthvalue_false_node;
3567         }
3568       else if (code == GE_EXPR)
3569         {
3570           if (!min_lt)
3571             val = truthvalue_true_node;
3572           if (max_lt)
3573             val = truthvalue_false_node;
3574         }
3575
3576       /* If primop0 was sign-extended and unsigned comparison specd,
3577          we did a signed comparison above using the signed type bounds.
3578          But the comparison we output must be unsigned.
3579
3580          Also, for inequalities, VAL is no good; but if the signed
3581          comparison had *any* fixed result, it follows that the
3582          unsigned comparison just tests the sign in reverse
3583          (positive values are LE, negative ones GE).
3584          So we can generate an unsigned comparison
3585          against an extreme value of the signed type.  */
3586
3587       if (unsignedp && !unsignedp0)
3588         {
3589           if (val != 0)
3590             switch (code)
3591               {
3592               case LT_EXPR:
3593               case GE_EXPR:
3594                 primop1 = TYPE_MIN_VALUE (type);
3595                 val = 0;
3596                 break;
3597
3598               case LE_EXPR:
3599               case GT_EXPR:
3600                 primop1 = TYPE_MAX_VALUE (type);
3601                 val = 0;
3602                 break;
3603
3604               default:
3605                 break;
3606               }
3607           type = c_common_unsigned_type (type);
3608         }
3609
3610       if (TREE_CODE (primop0) != INTEGER_CST)
3611         {
3612           if (val == truthvalue_false_node)
3613             warning (OPT_Wtype_limits, "comparison is always false due to limited range of data type");
3614           if (val == truthvalue_true_node)
3615             warning (OPT_Wtype_limits, "comparison is always true due to limited range of data type");
3616         }
3617
3618       if (val != 0)
3619         {
3620           /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
3621           if (TREE_SIDE_EFFECTS (primop0))
3622             return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
3623           return val;
3624         }
3625
3626       /* Value is not predetermined, but do the comparison
3627          in the type of the operand that is not constant.
3628          TYPE is already properly set.  */
3629     }
3630
3631   /* If either arg is decimal float and the other is float, find the
3632      proper common type to use for comparison.  */
3633   else if (real1 && real2
3634            && (DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop0)))
3635                || DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop1)))))
3636     type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
3637
3638   else if (real1 && real2
3639            && (TYPE_PRECISION (TREE_TYPE (primop0))
3640                == TYPE_PRECISION (TREE_TYPE (primop1))))
3641     type = TREE_TYPE (primop0);
3642
3643   /* If args' natural types are both narrower than nominal type
3644      and both extend in the same manner, compare them
3645      in the type of the wider arg.
3646      Otherwise must actually extend both to the nominal
3647      common type lest different ways of extending
3648      alter the result.
3649      (eg, (short)-1 == (unsigned short)-1  should be 0.)  */
3650
3651   else if (unsignedp0 == unsignedp1 && real1 == real2
3652            && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
3653            && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
3654     {
3655       type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
3656       type = c_common_signed_or_unsigned_type (unsignedp0
3657                                                || TYPE_UNSIGNED (*restype_ptr),
3658                                                type);
3659       /* Make sure shorter operand is extended the right way
3660          to match the longer operand.  */
3661       primop0
3662         = convert (c_common_signed_or_unsigned_type (unsignedp0,
3663                                                      TREE_TYPE (primop0)),
3664                    primop0);
3665       primop1
3666         = convert (c_common_signed_or_unsigned_type (unsignedp1,
3667                                                      TREE_TYPE (primop1)),
3668                    primop1);
3669     }
3670   else
3671     {
3672       /* Here we must do the comparison on the nominal type
3673          using the args exactly as we received them.  */
3674       type = *restype_ptr;
3675       primop0 = op0;
3676       primop1 = op1;
3677
3678       if (!real1 && !real2 && integer_zerop (primop1)
3679           && TYPE_UNSIGNED (*restype_ptr))
3680         {
3681           tree value = 0;
3682           switch (code)
3683             {
3684             case GE_EXPR:
3685               /* All unsigned values are >= 0, so we warn.  However,
3686                  if OP0 is a constant that is >= 0, the signedness of
3687                  the comparison isn't an issue, so suppress the
3688                  warning.  */
3689               if (warn_type_limits && !in_system_header
3690                   && !(TREE_CODE (primop0) == INTEGER_CST
3691                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
3692                                                    primop0))))
3693                 warning (OPT_Wtype_limits,
3694                          "comparison of unsigned expression >= 0 is always true");
3695               value = truthvalue_true_node;
3696               break;
3697
3698             case LT_EXPR:
3699               if (warn_type_limits && !in_system_header
3700                   && !(TREE_CODE (primop0) == INTEGER_CST
3701                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
3702                                                    primop0))))
3703                 warning (OPT_Wtype_limits,
3704                          "comparison of unsigned expression < 0 is always false");
3705               value = truthvalue_false_node;
3706               break;
3707
3708             default:
3709               break;
3710             }
3711
3712           if (value != 0)
3713             {
3714               /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
3715               if (TREE_SIDE_EFFECTS (primop0))
3716                 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
3717                                primop0, value);
3718               return value;
3719             }
3720         }
3721     }
3722
3723   *op0_ptr = convert (type, primop0);
3724   *op1_ptr = convert (type, primop1);
3725
3726   *restype_ptr = truthvalue_type_node;
3727
3728   return 0;
3729 }
3730 \f
3731 /* Return a tree for the sum or difference (RESULTCODE says which)
3732    of pointer PTROP and integer INTOP.  */
3733
3734 tree
3735 pointer_int_sum (location_t loc, enum tree_code resultcode,
3736                  tree ptrop, tree intop)
3737 {
3738   tree size_exp, ret;
3739
3740   /* The result is a pointer of the same type that is being added.  */
3741   tree result_type = TREE_TYPE (ptrop);
3742
3743   if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
3744     {
3745       pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3746                "pointer of type %<void *%> used in arithmetic");
3747       size_exp = integer_one_node;
3748     }
3749   else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE)
3750     {
3751       pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3752                "pointer to a function used in arithmetic");
3753       size_exp = integer_one_node;
3754     }
3755   else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE)
3756     {
3757       pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3758                "pointer to member function used in arithmetic");
3759       size_exp = integer_one_node;
3760     }
3761   else
3762     size_exp = size_in_bytes (TREE_TYPE (result_type));
3763
3764   /* We are manipulating pointer values, so we don't need to warn
3765      about relying on undefined signed overflow.  We disable the
3766      warning here because we use integer types so fold won't know that
3767      they are really pointers.  */
3768   fold_defer_overflow_warnings ();
3769
3770   /* If what we are about to multiply by the size of the elements
3771      contains a constant term, apply distributive law
3772      and multiply that constant term separately.
3773      This helps produce common subexpressions.  */
3774   if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
3775       && !TREE_CONSTANT (intop)
3776       && TREE_CONSTANT (TREE_OPERAND (intop, 1))
3777       && TREE_CONSTANT (size_exp)
3778       /* If the constant comes from pointer subtraction,
3779          skip this optimization--it would cause an error.  */
3780       && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
3781       /* If the constant is unsigned, and smaller than the pointer size,
3782          then we must skip this optimization.  This is because it could cause
3783          an overflow error if the constant is negative but INTOP is not.  */
3784       && (!TYPE_UNSIGNED (TREE_TYPE (intop))
3785           || (TYPE_PRECISION (TREE_TYPE (intop))
3786               == TYPE_PRECISION (TREE_TYPE (ptrop)))))
3787     {
3788       enum tree_code subcode = resultcode;
3789       tree int_type = TREE_TYPE (intop);
3790       if (TREE_CODE (intop) == MINUS_EXPR)
3791         subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
3792       /* Convert both subexpression types to the type of intop,
3793          because weird cases involving pointer arithmetic
3794          can result in a sum or difference with different type args.  */
3795       ptrop = build_binary_op (EXPR_LOCATION (TREE_OPERAND (intop, 1)),
3796                                subcode, ptrop,
3797                                convert (int_type, TREE_OPERAND (intop, 1)), 1);
3798       intop = convert (int_type, TREE_OPERAND (intop, 0));
3799     }
3800
3801   /* Convert the integer argument to a type the same size as sizetype
3802      so the multiply won't overflow spuriously.  */
3803   if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype)
3804       || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype))
3805     intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype),
3806                                              TYPE_UNSIGNED (sizetype)), intop);
3807
3808   /* Replace the integer argument with a suitable product by the object size.
3809      Do this multiplication as signed, then convert to the appropriate
3810      type for the pointer operation.  */
3811   intop = convert (sizetype,
3812                    build_binary_op (loc,
3813                                     MULT_EXPR, intop,
3814                                     convert (TREE_TYPE (intop), size_exp), 1));
3815
3816   /* Create the sum or difference.  */
3817   if (resultcode == MINUS_EXPR)
3818     intop = fold_build1_loc (loc, NEGATE_EXPR, sizetype, intop);
3819
3820   ret = fold_build2_loc (loc, POINTER_PLUS_EXPR, result_type, ptrop, intop);
3821
3822   fold_undefer_and_ignore_overflow_warnings ();
3823
3824   return ret;
3825 }
3826 \f
3827 /* Wrap a C_MAYBE_CONST_EXPR around an expression that is fully folded
3828    and if NON_CONST is known not to be permitted in an evaluated part
3829    of a constant expression.  */
3830
3831 tree
3832 c_wrap_maybe_const (tree expr, bool non_const)
3833 {
3834   bool nowarning = TREE_NO_WARNING (expr);
3835   location_t loc = EXPR_LOCATION (expr);
3836
3837   /* This should never be called for C++.  */
3838   if (c_dialect_cxx ())
3839     gcc_unreachable ();
3840
3841   /* The result of folding may have a NOP_EXPR to set TREE_NO_WARNING.  */
3842   STRIP_TYPE_NOPS (expr);
3843   expr = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (expr), NULL, expr);
3844   C_MAYBE_CONST_EXPR_NON_CONST (expr) = non_const;
3845   if (nowarning)
3846     TREE_NO_WARNING (expr) = 1;
3847   protected_set_expr_location (expr, loc);
3848
3849   return expr;
3850 }
3851
3852 /* Wrap a SAVE_EXPR around EXPR, if appropriate.  Like save_expr, but
3853    for C folds the inside expression and wraps a C_MAYBE_CONST_EXPR
3854    around the SAVE_EXPR if needed so that c_fully_fold does not need
3855    to look inside SAVE_EXPRs.  */
3856
3857 tree
3858 c_save_expr (tree expr)
3859 {
3860   bool maybe_const = true;
3861   if (c_dialect_cxx ())
3862     return save_expr (expr);
3863   expr = c_fully_fold (expr, false, &maybe_const);
3864   expr = save_expr (expr);
3865   if (!maybe_const)
3866     expr = c_wrap_maybe_const (expr, true);
3867   return expr;
3868 }
3869
3870 /* Return whether EXPR is a declaration whose address can never be
3871    NULL.  */
3872
3873 bool
3874 decl_with_nonnull_addr_p (const_tree expr)
3875 {
3876   return (DECL_P (expr)
3877           && (TREE_CODE (expr) == PARM_DECL
3878               || TREE_CODE (expr) == LABEL_DECL
3879               || !DECL_WEAK (expr)));
3880 }
3881
3882 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
3883    or for an `if' or `while' statement or ?..: exp.  It should already
3884    have been validated to be of suitable type; otherwise, a bad
3885    diagnostic may result.
3886
3887    The EXPR is located at LOCATION.
3888
3889    This preparation consists of taking the ordinary
3890    representation of an expression expr and producing a valid tree
3891    boolean expression describing whether expr is nonzero.  We could
3892    simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1),
3893    but we optimize comparisons, &&, ||, and !.
3894
3895    The resulting type should always be `truthvalue_type_node'.  */
3896
3897 tree
3898 c_common_truthvalue_conversion (location_t location, tree expr)
3899 {
3900   switch (TREE_CODE (expr))
3901     {
3902     case EQ_EXPR:   case NE_EXPR:   case UNEQ_EXPR: case LTGT_EXPR:
3903     case LE_EXPR:   case GE_EXPR:   case LT_EXPR:   case GT_EXPR:
3904     case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR:
3905     case ORDERED_EXPR: case UNORDERED_EXPR:
3906       if (TREE_TYPE (expr) == truthvalue_type_node)
3907         return expr;
3908       expr = build2 (TREE_CODE (expr), truthvalue_type_node,
3909                      TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1));
3910       goto ret;
3911
3912     case TRUTH_ANDIF_EXPR:
3913     case TRUTH_ORIF_EXPR:
3914     case TRUTH_AND_EXPR:
3915     case TRUTH_OR_EXPR:
3916     case TRUTH_XOR_EXPR:
3917       if (TREE_TYPE (expr) == truthvalue_type_node)
3918         return expr;
3919       expr = build2 (TREE_CODE (expr), truthvalue_type_node,
3920                      c_common_truthvalue_conversion (location,
3921                                                      TREE_OPERAND (expr, 0)),
3922                      c_common_truthvalue_conversion (location,
3923                                                      TREE_OPERAND (expr, 1)));
3924       goto ret;
3925
3926     case TRUTH_NOT_EXPR:
3927       if (TREE_TYPE (expr) == truthvalue_type_node)
3928         return expr;
3929       expr = build1 (TREE_CODE (expr), truthvalue_type_node,
3930                      c_common_truthvalue_conversion (location,
3931                                                      TREE_OPERAND (expr, 0)));
3932       goto ret;
3933
3934     case ERROR_MARK:
3935       return expr;
3936
3937     case INTEGER_CST:
3938       return integer_zerop (expr) ? truthvalue_false_node
3939                                   : truthvalue_true_node;
3940
3941     case REAL_CST:
3942       return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0)
3943              ? truthvalue_true_node
3944              : truthvalue_false_node;
3945
3946     case FIXED_CST:
3947       return fixed_compare (NE_EXPR, &TREE_FIXED_CST (expr),
3948                             &FCONST0 (TYPE_MODE (TREE_TYPE (expr))))
3949              ? truthvalue_true_node
3950              : truthvalue_false_node;
3951
3952     case FUNCTION_DECL:
3953       expr = build_unary_op (location, ADDR_EXPR, expr, 0);
3954       /* Fall through.  */
3955
3956     case ADDR_EXPR:
3957       {
3958         tree inner = TREE_OPERAND (expr, 0);
3959         if (decl_with_nonnull_addr_p (inner))
3960           {
3961             /* Common Ada/Pascal programmer's mistake.  */
3962             warning_at (location,
3963                         OPT_Waddress,
3964                         "the address of %qD will always evaluate as %<true%>",
3965                         inner);
3966             return truthvalue_true_node;
3967           }
3968
3969         /* If we still have a decl, it is possible for its address to
3970            be NULL, so we cannot optimize.  */
3971         if (DECL_P (inner))
3972           {
3973             gcc_assert (DECL_WEAK (inner));
3974             break;
3975           }
3976
3977         if (TREE_SIDE_EFFECTS (inner))
3978           {
3979             expr = build2 (COMPOUND_EXPR, truthvalue_type_node,
3980                            inner, truthvalue_true_node);
3981             goto ret;
3982           }
3983         else
3984           return truthvalue_true_node;
3985       }
3986
3987     case COMPLEX_EXPR:
3988       expr = build_binary_op (EXPR_LOCATION (expr),
3989                               (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
3990                                ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
3991                 c_common_truthvalue_conversion (location,
3992                                                 TREE_OPERAND (expr, 0)),
3993                 c_common_truthvalue_conversion (location,
3994                                                 TREE_OPERAND (expr, 1)),
3995                               0);
3996       goto ret;
3997
3998     case NEGATE_EXPR:
3999     case ABS_EXPR:
4000     case FLOAT_EXPR:
4001     case EXCESS_PRECISION_EXPR:
4002       /* These don't change whether an object is nonzero or zero.  */
4003       return c_common_truthvalue_conversion (location, TREE_OPERAND (expr, 0));
4004
4005     case LROTATE_EXPR:
4006     case RROTATE_EXPR:
4007       /* These don't change whether an object is zero or nonzero, but
4008          we can't ignore them if their second arg has side-effects.  */
4009       if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
4010         {
4011           expr = build2 (COMPOUND_EXPR, truthvalue_type_node,
4012                          TREE_OPERAND (expr, 1),
4013                          c_common_truthvalue_conversion
4014                          (location, TREE_OPERAND (expr, 0)));
4015           goto ret;
4016         }
4017       else
4018         return c_common_truthvalue_conversion (location,
4019                                                TREE_OPERAND (expr, 0));
4020
4021     case COND_EXPR:
4022       /* Distribute the conversion into the arms of a COND_EXPR.  */
4023       if (c_dialect_cxx ())
4024         {
4025           expr = fold_build3_loc (location, COND_EXPR, truthvalue_type_node,
4026                               TREE_OPERAND (expr, 0),
4027                               c_common_truthvalue_conversion (location,
4028                                                               TREE_OPERAND (expr,
4029                                                                             1)),
4030                               c_common_truthvalue_conversion (location,
4031                                                               TREE_OPERAND (expr,
4032                                                                             2)));
4033           goto ret;
4034         }
4035       else
4036         {
4037           /* Folding will happen later for C.  */
4038           expr = build3 (COND_EXPR, truthvalue_type_node,
4039                          TREE_OPERAND (expr, 0),
4040                          c_common_truthvalue_conversion (location,
4041                                                          TREE_OPERAND (expr, 1)),
4042                          c_common_truthvalue_conversion (location,
4043                                                          TREE_OPERAND (expr, 2)));
4044           goto ret;
4045         }
4046
4047     CASE_CONVERT:
4048       /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
4049          since that affects how `default_conversion' will behave.  */
4050       if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
4051           || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
4052         break;
4053       /* If this is widening the argument, we can ignore it.  */
4054       if (TYPE_PRECISION (TREE_TYPE (expr))
4055           >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
4056         return c_common_truthvalue_conversion (location,
4057                                                TREE_OPERAND (expr, 0));
4058       break;
4059
4060     case MODIFY_EXPR:
4061       if (!TREE_NO_WARNING (expr)
4062           && warn_parentheses)
4063         {
4064           warning (OPT_Wparentheses,
4065                    "suggest parentheses around assignment used as truth value");
4066           TREE_NO_WARNING (expr) = 1;
4067         }
4068       break;
4069
4070     default:
4071       break;
4072     }
4073
4074   if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
4075     {
4076       tree t = c_save_expr (expr);
4077       expr = (build_binary_op
4078               (EXPR_LOCATION (expr),
4079                (TREE_SIDE_EFFECTS (expr)
4080                 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
4081         c_common_truthvalue_conversion
4082                (location,
4083                 build_unary_op (location, REALPART_EXPR, t, 0)),
4084         c_common_truthvalue_conversion
4085                (location,
4086                 build_unary_op (location, IMAGPART_EXPR, t, 0)),
4087                0));
4088       goto ret;
4089     }
4090
4091   if (TREE_CODE (TREE_TYPE (expr)) == FIXED_POINT_TYPE)
4092     {
4093       tree fixed_zero_node = build_fixed (TREE_TYPE (expr),
4094                                           FCONST0 (TYPE_MODE
4095                                                    (TREE_TYPE (expr))));
4096       return build_binary_op (location, NE_EXPR, expr, fixed_zero_node, 1);
4097     }
4098   else
4099     return build_binary_op (location, NE_EXPR, expr, integer_zero_node, 1);
4100
4101  ret:
4102   protected_set_expr_location (expr, location);
4103   return expr;
4104 }
4105 \f
4106 static void def_builtin_1  (enum built_in_function fncode,
4107                             const char *name,
4108                             enum built_in_class fnclass,
4109                             tree fntype, tree libtype,
4110                             bool both_p, bool fallback_p, bool nonansi_p,
4111                             tree fnattrs, bool implicit_p);
4112
4113
4114 /* Apply the TYPE_QUALS to the new DECL.  */
4115
4116 void
4117 c_apply_type_quals_to_decl (int type_quals, tree decl)
4118 {
4119   tree type = TREE_TYPE (decl);
4120
4121   if (type == error_mark_node)
4122     return;
4123
4124   if (((type_quals & TYPE_QUAL_CONST)
4125        || (type && TREE_CODE (type) == REFERENCE_TYPE))
4126       /* An object declared 'const' is only readonly after it is
4127          initialized.  We don't have any way of expressing this currently,
4128          so we need to be conservative and unset TREE_READONLY for types
4129          with constructors.  Otherwise aliasing code will ignore stores in
4130          an inline constructor.  */
4131       && !(type && TYPE_NEEDS_CONSTRUCTING (type)))
4132     TREE_READONLY (decl) = 1;
4133   if (type_quals & TYPE_QUAL_VOLATILE)
4134     {
4135       TREE_SIDE_EFFECTS (decl) = 1;
4136       TREE_THIS_VOLATILE (decl) = 1;
4137     }
4138   if (type_quals & TYPE_QUAL_RESTRICT)
4139     {
4140       while (type && TREE_CODE (type) == ARRAY_TYPE)
4141         /* Allow 'restrict' on arrays of pointers.
4142            FIXME currently we just ignore it.  */
4143         type = TREE_TYPE (type);
4144       if (!type
4145           || !POINTER_TYPE_P (type)
4146           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))
4147         error ("invalid use of %<restrict%>");
4148     }
4149 }
4150
4151 /* Hash function for the problem of multiple type definitions in
4152    different files.  This must hash all types that will compare
4153    equal via comptypes to the same value.  In practice it hashes
4154    on some of the simple stuff and leaves the details to comptypes.  */
4155
4156 static hashval_t
4157 c_type_hash (const void *p)
4158 {
4159   int i = 0;
4160   int shift, size;
4161   const_tree const t = (const_tree) p;
4162   tree t2;
4163   switch (TREE_CODE (t))
4164     {
4165     /* For pointers, hash on pointee type plus some swizzling.  */
4166     case POINTER_TYPE:
4167       return c_type_hash (TREE_TYPE (t)) ^ 0x3003003;
4168     /* Hash on number of elements and total size.  */
4169     case ENUMERAL_TYPE:
4170       shift = 3;
4171       t2 = TYPE_VALUES (t);
4172       break;
4173     case RECORD_TYPE:
4174       shift = 0;
4175       t2 = TYPE_FIELDS (t);
4176       break;
4177     case QUAL_UNION_TYPE:
4178       shift = 1;
4179       t2 = TYPE_FIELDS (t);
4180       break;
4181     case UNION_TYPE:
4182       shift = 2;
4183       t2 = TYPE_FIELDS (t);
4184       break;
4185     default:
4186       gcc_unreachable ();
4187     }
4188   for (; t2; t2 = TREE_CHAIN (t2))
4189     i++;
4190   /* We might have a VLA here.  */
4191   if (TREE_CODE (TYPE_SIZE (t)) != INTEGER_CST)
4192     size = 0;
4193   else
4194     size = TREE_INT_CST_LOW (TYPE_SIZE (t));
4195   return ((size << 24) | (i << shift));
4196 }
4197
4198 static GTY((param_is (union tree_node))) htab_t type_hash_table;
4199
4200 /* Return the typed-based alias set for T, which may be an expression
4201    or a type.  Return -1 if we don't do anything special.  */
4202
4203 alias_set_type
4204 c_common_get_alias_set (tree t)
4205 {
4206   tree u;
4207   PTR *slot;
4208
4209   /* For VLAs, use the alias set of the element type rather than the
4210      default of alias set 0 for types compared structurally.  */
4211   if (TYPE_P (t) && TYPE_STRUCTURAL_EQUALITY_P (t))
4212     {
4213       if (TREE_CODE (t) == ARRAY_TYPE)
4214         return get_alias_set (TREE_TYPE (t));
4215       return -1;
4216     }
4217
4218   /* Permit type-punning when accessing a union, provided the access
4219      is directly through the union.  For example, this code does not
4220      permit taking the address of a union member and then storing
4221      through it.  Even the type-punning allowed here is a GCC
4222      extension, albeit a common and useful one; the C standard says
4223      that such accesses have implementation-defined behavior.  */
4224   for (u = t;
4225        TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
4226        u = TREE_OPERAND (u, 0))
4227     if (TREE_CODE (u) == COMPONENT_REF
4228         && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
4229       return 0;
4230
4231   /* That's all the expressions we handle specially.  */
4232   if (!TYPE_P (t))
4233     return -1;
4234
4235   /* The C standard guarantees that any object may be accessed via an
4236      lvalue that has character type.  */
4237   if (t == char_type_node
4238       || t == signed_char_type_node
4239       || t == unsigned_char_type_node)
4240     return 0;
4241
4242   /* The C standard specifically allows aliasing between signed and
4243      unsigned variants of the same type.  We treat the signed
4244      variant as canonical.  */
4245   if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t))
4246     {
4247       tree t1 = c_common_signed_type (t);
4248
4249       /* t1 == t can happen for boolean nodes which are always unsigned.  */
4250       if (t1 != t)
4251         return get_alias_set (t1);
4252     }
4253   else if (POINTER_TYPE_P (t))
4254     {
4255       tree t1;
4256
4257       /* Unfortunately, there is no canonical form of a pointer type.
4258          In particular, if we have `typedef int I', then `int *', and
4259          `I *' are different types.  So, we have to pick a canonical
4260          representative.  We do this below.
4261
4262          Technically, this approach is actually more conservative that
4263          it needs to be.  In particular, `const int *' and `int *'
4264          should be in different alias sets, according to the C and C++
4265          standard, since their types are not the same, and so,
4266          technically, an `int **' and `const int **' cannot point at
4267          the same thing.
4268
4269          But, the standard is wrong.  In particular, this code is
4270          legal C++:
4271
4272             int *ip;
4273             int **ipp = &ip;
4274             const int* const* cipp = ipp;
4275
4276          And, it doesn't make sense for that to be legal unless you
4277          can dereference IPP and CIPP.  So, we ignore cv-qualifiers on
4278          the pointed-to types.  This issue has been reported to the
4279          C++ committee.  */
4280       t1 = build_type_no_quals (t);
4281       if (t1 != t)
4282         return get_alias_set (t1);
4283     }
4284
4285   /* Handle the case of multiple type nodes referring to "the same" type,
4286      which occurs with IMA.  These share an alias set.  FIXME:  Currently only
4287      C90 is handled.  (In C99 type compatibility is not transitive, which
4288      complicates things mightily. The alias set splay trees can theoretically
4289      represent this, but insertion is tricky when you consider all the
4290      different orders things might arrive in.) */
4291
4292   if (c_language != clk_c || flag_isoc99)
4293     return -1;
4294
4295   /* Save time if there's only one input file.  */
4296   if (num_in_fnames == 1)
4297     return -1;
4298
4299   /* Pointers need special handling if they point to any type that
4300      needs special handling (below).  */
4301   if (TREE_CODE (t) == POINTER_TYPE)
4302     {
4303       tree t2;
4304       /* Find bottom type under any nested POINTERs.  */
4305       for (t2 = TREE_TYPE (t);
4306            TREE_CODE (t2) == POINTER_TYPE;
4307            t2 = TREE_TYPE (t2))
4308         ;
4309       if (TREE_CODE (t2) != RECORD_TYPE
4310           && TREE_CODE (t2) != ENUMERAL_TYPE
4311           && TREE_CODE (t2) != QUAL_UNION_TYPE
4312           && TREE_CODE (t2) != UNION_TYPE)
4313         return -1;
4314       if (TYPE_SIZE (t2) == 0)
4315         return -1;
4316     }
4317   /* These are the only cases that need special handling.  */
4318   if (TREE_CODE (t) != RECORD_TYPE
4319       && TREE_CODE (t) != ENUMERAL_TYPE
4320       && TREE_CODE (t) != QUAL_UNION_TYPE
4321       && TREE_CODE (t) != UNION_TYPE
4322       && TREE_CODE (t) != POINTER_TYPE)
4323     return -1;
4324   /* Undefined? */
4325   if (TYPE_SIZE (t) == 0)
4326     return -1;
4327
4328   /* Look up t in hash table.  Only one of the compatible types within each
4329      alias set is recorded in the table.  */
4330   if (!type_hash_table)
4331     type_hash_table = htab_create_ggc (1021, c_type_hash,
4332             (htab_eq) lang_hooks.types_compatible_p,
4333             NULL);
4334   slot = htab_find_slot (type_hash_table, t, INSERT);
4335   if (*slot != NULL)
4336     {
4337       TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot);
4338       return TYPE_ALIAS_SET ((tree)*slot);
4339     }
4340   else
4341     /* Our caller will assign and record (in t) a new alias set; all we need
4342        to do is remember t in the hash table.  */
4343     *slot = t;
4344
4345   return -1;
4346 }
4347 \f
4348 /* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where
4349    the second parameter indicates which OPERATOR is being applied.
4350    The COMPLAIN flag controls whether we should diagnose possibly
4351    ill-formed constructs or not.  LOC is the location of the SIZEOF or
4352    TYPEOF operator.  */
4353
4354 tree
4355 c_sizeof_or_alignof_type (location_t loc,
4356                           tree type, bool is_sizeof, int complain)
4357 {
4358   const char *op_name;
4359   tree value = NULL;
4360   enum tree_code type_code = TREE_CODE (type);
4361
4362   op_name = is_sizeof ? "sizeof" : "__alignof__";
4363
4364   if (type_code == FUNCTION_TYPE)
4365     {
4366       if (is_sizeof)
4367         {
4368           if (complain && (pedantic || warn_pointer_arith))
4369             pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
4370                      "invalid application of %<sizeof%> to a function type");
4371           else if (!complain)
4372             return error_mark_node;
4373           value = size_one_node;
4374         }
4375       else
4376         value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);
4377     }
4378   else if (type_code == VOID_TYPE || type_code == ERROR_MARK)
4379     {
4380       if (type_code == VOID_TYPE
4381           && complain && (pedantic || warn_pointer_arith))
4382         pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
4383                  "invalid application of %qs to a void type", op_name);
4384       else if (!complain)
4385         return error_mark_node;
4386       value = size_one_node;
4387     }
4388   else if (!COMPLETE_TYPE_P (type))
4389     {
4390       if (complain)
4391         error_at (loc, "invalid application of %qs to incomplete type %qT ",
4392                   op_name, type);
4393       value = size_zero_node;
4394     }
4395   else
4396     {
4397       if (is_sizeof)
4398         /* Convert in case a char is more than one unit.  */
4399         value = size_binop_loc (loc, CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
4400                                 size_int (TYPE_PRECISION (char_type_node)
4401                                           / BITS_PER_UNIT));
4402       else
4403         value = size_int (TYPE_ALIGN_UNIT (type));
4404     }
4405
4406   /* VALUE will have an integer type with TYPE_IS_SIZETYPE set.
4407      TYPE_IS_SIZETYPE means that certain things (like overflow) will
4408      never happen.  However, this node should really have type
4409      `size_t', which is just a typedef for an ordinary integer type.  */
4410   value = fold_convert_loc (loc, size_type_node, value);
4411   gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value)));
4412
4413   return value;
4414 }
4415
4416 /* Implement the __alignof keyword: Return the minimum required
4417    alignment of EXPR, measured in bytes.  For VAR_DECLs,
4418    FUNCTION_DECLs and FIELD_DECLs return DECL_ALIGN (which can be set
4419    from an "aligned" __attribute__ specification).  LOC is the
4420    location of the ALIGNOF operator.  */
4421
4422 tree
4423 c_alignof_expr (location_t loc, tree expr)
4424 {
4425   tree t;
4426
4427   if (VAR_OR_FUNCTION_DECL_P (expr))
4428     t = size_int (DECL_ALIGN_UNIT (expr));
4429
4430   else if (TREE_CODE (expr) == COMPONENT_REF
4431            && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1)))
4432     {
4433       error_at (loc, "%<__alignof%> applied to a bit-field");
4434       t = size_one_node;
4435     }
4436   else if (TREE_CODE (expr) == COMPONENT_REF
4437            && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL)
4438     t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1)));
4439
4440   else if (TREE_CODE (expr) == INDIRECT_REF)
4441     {
4442       tree t = TREE_OPERAND (expr, 0);
4443       tree best = t;
4444       int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
4445
4446       while (CONVERT_EXPR_P (t)
4447              && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE)
4448         {
4449           int thisalign;
4450
4451           t = TREE_OPERAND (t, 0);
4452           thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
4453           if (thisalign > bestalign)
4454             best = t, bestalign = thisalign;
4455         }
4456       return c_alignof (loc, TREE_TYPE (TREE_TYPE (best)));
4457     }
4458   else
4459     return c_alignof (loc, TREE_TYPE (expr));
4460
4461   return fold_convert_loc (loc, size_type_node, t);
4462 }
4463 \f
4464 /* Handle C and C++ default attributes.  */
4465
4466 enum built_in_attribute
4467 {
4468 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
4469 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
4470 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
4471 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
4472 #include "builtin-attrs.def"
4473 #undef DEF_ATTR_NULL_TREE
4474 #undef DEF_ATTR_INT
4475 #undef DEF_ATTR_IDENT
4476 #undef DEF_ATTR_TREE_LIST
4477   ATTR_LAST
4478 };
4479
4480 static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
4481
4482 static void c_init_attributes (void);
4483
4484 enum c_builtin_type
4485 {
4486 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
4487 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
4488 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
4489 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
4490 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
4491 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
4492 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
4493 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) NAME,
4494 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7) NAME,
4495 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
4496 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
4497 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
4498 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
4499 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
4500 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \
4501   NAME,
4502 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
4503 #include "builtin-types.def"
4504 #undef DEF_PRIMITIVE_TYPE
4505 #undef DEF_FUNCTION_TYPE_0
4506 #undef DEF_FUNCTION_TYPE_1
4507 #undef DEF_FUNCTION_TYPE_2
4508 #undef DEF_FUNCTION_TYPE_3
4509 #undef DEF_FUNCTION_TYPE_4
4510 #undef DEF_FUNCTION_TYPE_5
4511 #undef DEF_FUNCTION_TYPE_6
4512 #undef DEF_FUNCTION_TYPE_7
4513 #undef DEF_FUNCTION_TYPE_VAR_0
4514 #undef DEF_FUNCTION_TYPE_VAR_1
4515 #undef DEF_FUNCTION_TYPE_VAR_2
4516 #undef DEF_FUNCTION_TYPE_VAR_3
4517 #undef DEF_FUNCTION_TYPE_VAR_4
4518 #undef DEF_FUNCTION_TYPE_VAR_5
4519 #undef DEF_POINTER_TYPE
4520   BT_LAST
4521 };
4522
4523 typedef enum c_builtin_type builtin_type;
4524
4525 /* A temporary array for c_common_nodes_and_builtins.  Used in
4526    communication with def_fn_type.  */
4527 static tree builtin_types[(int) BT_LAST + 1];
4528
4529 /* A helper function for c_common_nodes_and_builtins.  Build function type
4530    for DEF with return type RET and N arguments.  If VAR is true, then the
4531    function should be variadic after those N arguments.
4532
4533    Takes special care not to ICE if any of the types involved are
4534    error_mark_node, which indicates that said type is not in fact available
4535    (see builtin_type_for_size).  In which case the function type as a whole
4536    should be error_mark_node.  */
4537
4538 static void
4539 def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...)
4540 {
4541   tree args = NULL, t;
4542   va_list list;
4543   int i;
4544
4545   va_start (list, n);
4546   for (i = 0; i < n; ++i)
4547     {
4548       builtin_type a = (builtin_type) va_arg (list, int);
4549       t = builtin_types[a];
4550       if (t == error_mark_node)
4551         goto egress;
4552       args = tree_cons (NULL_TREE, t, args);
4553     }
4554   va_end (list);
4555
4556   args = nreverse (args);
4557   if (!var)
4558     args = chainon (args, void_list_node);
4559
4560   t = builtin_types[ret];
4561   if (t == error_mark_node)
4562     goto egress;
4563   t = build_function_type (t, args);
4564
4565  egress:
4566   builtin_types[def] = t;
4567 }
4568
4569 /* Build builtin functions common to both C and C++ language
4570    frontends.  */
4571
4572 static void
4573 c_define_builtins (tree va_list_ref_type_node, tree va_list_arg_type_node)
4574 {
4575 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
4576   builtin_types[ENUM] = VALUE;
4577 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
4578   def_fn_type (ENUM, RETURN, 0, 0);
4579 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
4580   def_fn_type (ENUM, RETURN, 0, 1, ARG1);
4581 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
4582   def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
4583 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
4584   def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
4585 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
4586   def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
4587 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
4588   def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
4589 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
4590                             ARG6)                                       \
4591   def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
4592 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
4593                             ARG6, ARG7)                                 \
4594   def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
4595 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
4596   def_fn_type (ENUM, RETURN, 1, 0);
4597 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
4598   def_fn_type (ENUM, RETURN, 1, 1, ARG1);
4599 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
4600   def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
4601 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
4602   def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
4603 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
4604   def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
4605 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
4606   def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
4607 #define DEF_POINTER_TYPE(ENUM, TYPE) \
4608   builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
4609
4610 #include "builtin-types.def"
4611
4612 #undef DEF_PRIMITIVE_TYPE
4613 #undef DEF_FUNCTION_TYPE_1
4614 #undef DEF_FUNCTION_TYPE_2
4615 #undef DEF_FUNCTION_TYPE_3
4616 #undef DEF_FUNCTION_TYPE_4
4617 #undef DEF_FUNCTION_TYPE_5
4618 #undef DEF_FUNCTION_TYPE_6
4619 #undef DEF_FUNCTION_TYPE_VAR_0
4620 #undef DEF_FUNCTION_TYPE_VAR_1
4621 #undef DEF_FUNCTION_TYPE_VAR_2
4622 #undef DEF_FUNCTION_TYPE_VAR_3
4623 #undef DEF_FUNCTION_TYPE_VAR_4
4624 #undef DEF_FUNCTION_TYPE_VAR_5
4625 #undef DEF_POINTER_TYPE
4626   builtin_types[(int) BT_LAST] = NULL_TREE;
4627
4628   c_init_attributes ();
4629
4630 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
4631                     NONANSI_P, ATTRS, IMPLICIT, COND)                   \
4632   if (NAME && COND)                                                     \
4633     def_builtin_1 (ENUM, NAME, CLASS,                                   \
4634                    builtin_types[(int) TYPE],                           \
4635                    builtin_types[(int) LIBTYPE],                        \
4636                    BOTH_P, FALLBACK_P, NONANSI_P,                       \
4637                    built_in_attributes[(int) ATTRS], IMPLICIT);
4638 #include "builtins.def"
4639 #undef DEF_BUILTIN
4640
4641   targetm.init_builtins ();
4642
4643   build_common_builtin_nodes ();
4644
4645   if (flag_mudflap)
4646     mudflap_init ();
4647 }
4648
4649 /* Like get_identifier, but avoid warnings about null arguments when
4650    the argument may be NULL for targets where GCC lacks stdint.h type
4651    information.  */
4652
4653 static inline tree
4654 c_get_ident (const char *id)
4655 {
4656   return get_identifier (id);
4657 }
4658
4659 /* Build tree nodes and builtin functions common to both C and C++ language
4660    frontends.  */
4661
4662 void
4663 c_common_nodes_and_builtins (void)
4664 {
4665   int char16_type_size;
4666   int char32_type_size;
4667   int wchar_type_size;
4668   tree array_domain_type;
4669   tree va_list_ref_type_node;
4670   tree va_list_arg_type_node;
4671
4672   /* Define `int' and `char' first so that dbx will output them first.  */
4673   record_builtin_type (RID_INT, NULL, integer_type_node);
4674   record_builtin_type (RID_CHAR, "char", char_type_node);
4675
4676   /* `signed' is the same as `int'.  FIXME: the declarations of "signed",
4677      "unsigned long", "long long unsigned" and "unsigned short" were in C++
4678      but not C.  Are the conditionals here needed?  */
4679   if (c_dialect_cxx ())
4680     record_builtin_type (RID_SIGNED, NULL, integer_type_node);
4681   record_builtin_type (RID_LONG, "long int", long_integer_type_node);
4682   record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
4683   record_builtin_type (RID_MAX, "long unsigned int",
4684                        long_unsigned_type_node);
4685   if (c_dialect_cxx ())
4686     record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
4687   record_builtin_type (RID_MAX, "long long int",
4688                        long_long_integer_type_node);
4689   record_builtin_type (RID_MAX, "long long unsigned int",
4690                        long_long_unsigned_type_node);
4691   if (c_dialect_cxx ())
4692     record_builtin_type (RID_MAX, "long long unsigned",
4693                          long_long_unsigned_type_node);
4694   record_builtin_type (RID_SHORT, "short int", short_integer_type_node);
4695   record_builtin_type (RID_MAX, "short unsigned int",
4696                        short_unsigned_type_node);
4697   if (c_dialect_cxx ())
4698     record_builtin_type (RID_MAX, "unsigned short",
4699                          short_unsigned_type_node);
4700
4701   /* Define both `signed char' and `unsigned char'.  */
4702   record_builtin_type (RID_MAX, "signed char", signed_char_type_node);
4703   record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node);
4704
4705   /* These are types that c_common_type_for_size and
4706      c_common_type_for_mode use.  */
4707   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4708                                          TYPE_DECL, NULL_TREE,
4709                                          intQI_type_node));
4710   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4711                                          TYPE_DECL, NULL_TREE,
4712                                          intHI_type_node));
4713   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4714                                          TYPE_DECL, NULL_TREE,
4715                                          intSI_type_node));
4716   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4717                                          TYPE_DECL, NULL_TREE,
4718                                          intDI_type_node));
4719 #if HOST_BITS_PER_WIDE_INT >= 64
4720   if (targetm.scalar_mode_supported_p (TImode))
4721     lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4722                                            TYPE_DECL,
4723                                            get_identifier ("__int128_t"),
4724                                            intTI_type_node));
4725 #endif
4726   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4727                                          TYPE_DECL, NULL_TREE,
4728                                          unsigned_intQI_type_node));
4729   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4730                                          TYPE_DECL, NULL_TREE,
4731                                          unsigned_intHI_type_node));
4732   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4733                                          TYPE_DECL, NULL_TREE,
4734                                          unsigned_intSI_type_node));
4735   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4736                                          TYPE_DECL, NULL_TREE,
4737                                          unsigned_intDI_type_node));
4738 #if HOST_BITS_PER_WIDE_INT >= 64
4739   if (targetm.scalar_mode_supported_p (TImode))
4740     lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4741                                            TYPE_DECL,
4742                                            get_identifier ("__uint128_t"),
4743                                            unsigned_intTI_type_node));
4744 #endif
4745
4746   /* Create the widest literal types.  */
4747   widest_integer_literal_type_node
4748     = make_signed_type (HOST_BITS_PER_WIDE_INT * 2);
4749   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4750                                          TYPE_DECL, NULL_TREE,
4751                                          widest_integer_literal_type_node));
4752
4753   widest_unsigned_literal_type_node
4754     = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2);
4755   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4756                                          TYPE_DECL, NULL_TREE,
4757                                          widest_unsigned_literal_type_node));
4758
4759   /* `unsigned long' is the standard type for sizeof.
4760      Note that stddef.h uses `unsigned long',
4761      and this must agree, even if long and int are the same size.  */
4762   size_type_node =
4763     TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE)));
4764   signed_size_type_node = c_common_signed_type (size_type_node);
4765   set_sizetype (size_type_node);
4766
4767   pid_type_node =
4768     TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE)));
4769
4770   build_common_tree_nodes_2 (flag_short_double);
4771
4772   record_builtin_type (RID_FLOAT, NULL, float_type_node);
4773   record_builtin_type (RID_DOUBLE, NULL, double_type_node);
4774   record_builtin_type (RID_MAX, "long double", long_double_type_node);
4775
4776   /* Only supported decimal floating point extension if the target
4777      actually supports underlying modes. */
4778   if (targetm.scalar_mode_supported_p (SDmode)
4779       && targetm.scalar_mode_supported_p (DDmode)
4780       && targetm.scalar_mode_supported_p (TDmode))
4781     {
4782       record_builtin_type (RID_DFLOAT32, NULL, dfloat32_type_node);
4783       record_builtin_type (RID_DFLOAT64, NULL, dfloat64_type_node);
4784       record_builtin_type (RID_DFLOAT128, NULL, dfloat128_type_node);
4785     }
4786
4787   if (targetm.fixed_point_supported_p ())
4788     {
4789       record_builtin_type (RID_MAX, "short _Fract", short_fract_type_node);
4790       record_builtin_type (RID_FRACT, NULL, fract_type_node);
4791       record_builtin_type (RID_MAX, "long _Fract", long_fract_type_node);
4792       record_builtin_type (RID_MAX, "long long _Fract",
4793                            long_long_fract_type_node);
4794       record_builtin_type (RID_MAX, "unsigned short _Fract",
4795                            unsigned_short_fract_type_node);
4796       record_builtin_type (RID_MAX, "unsigned _Fract",
4797                            unsigned_fract_type_node);
4798       record_builtin_type (RID_MAX, "unsigned long _Fract",
4799                            unsigned_long_fract_type_node);
4800       record_builtin_type (RID_MAX, "unsigned long long _Fract",
4801                            unsigned_long_long_fract_type_node);
4802       record_builtin_type (RID_MAX, "_Sat short _Fract",
4803                            sat_short_fract_type_node);
4804       record_builtin_type (RID_MAX, "_Sat _Fract", sat_fract_type_node);
4805       record_builtin_type (RID_MAX, "_Sat long _Fract",
4806                            sat_long_fract_type_node);
4807       record_builtin_type (RID_MAX, "_Sat long long _Fract",
4808                            sat_long_long_fract_type_node);
4809       record_builtin_type (RID_MAX, "_Sat unsigned short _Fract",
4810                            sat_unsigned_short_fract_type_node);
4811       record_builtin_type (RID_MAX, "_Sat unsigned _Fract",
4812                            sat_unsigned_fract_type_node);
4813       record_builtin_type (RID_MAX, "_Sat unsigned long _Fract",
4814                            sat_unsigned_long_fract_type_node);
4815       record_builtin_type (RID_MAX, "_Sat unsigned long long _Fract",
4816                            sat_unsigned_long_long_fract_type_node);
4817       record_builtin_type (RID_MAX, "short _Accum", short_accum_type_node);
4818       record_builtin_type (RID_ACCUM, NULL, accum_type_node);
4819       record_builtin_type (RID_MAX, "long _Accum", long_accum_type_node);
4820       record_builtin_type (RID_MAX, "long long _Accum",
4821                            long_long_accum_type_node);
4822       record_builtin_type (RID_MAX, "unsigned short _Accum",
4823                            unsigned_short_accum_type_node);
4824       record_builtin_type (RID_MAX, "unsigned _Accum",
4825                            unsigned_accum_type_node);
4826       record_builtin_type (RID_MAX, "unsigned long _Accum",
4827                            unsigned_long_accum_type_node);
4828       record_builtin_type (RID_MAX, "unsigned long long _Accum",
4829                            unsigned_long_long_accum_type_node);
4830       record_builtin_type (RID_MAX, "_Sat short _Accum",
4831                            sat_short_accum_type_node);
4832       record_builtin_type (RID_MAX, "_Sat _Accum", sat_accum_type_node);
4833       record_builtin_type (RID_MAX, "_Sat long _Accum",
4834                            sat_long_accum_type_node);
4835       record_builtin_type (RID_MAX, "_Sat long long _Accum",
4836                           sat_long_long_accum_type_node);
4837       record_builtin_type (RID_MAX, "_Sat unsigned short _Accum",
4838                            sat_unsigned_short_accum_type_node);
4839       record_builtin_type (RID_MAX, "_Sat unsigned _Accum",
4840                            sat_unsigned_accum_type_node);
4841       record_builtin_type (RID_MAX, "_Sat unsigned long _Accum",
4842                            sat_unsigned_long_accum_type_node);
4843       record_builtin_type (RID_MAX, "_Sat unsigned long long _Accum",
4844                            sat_unsigned_long_long_accum_type_node);
4845
4846     }
4847
4848   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4849                                          TYPE_DECL,
4850                                          get_identifier ("complex int"),
4851                                          complex_integer_type_node));
4852   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4853                                          TYPE_DECL,
4854                                          get_identifier ("complex float"),
4855                                          complex_float_type_node));
4856   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4857                                          TYPE_DECL,
4858                                          get_identifier ("complex double"),
4859                                          complex_double_type_node));
4860   lang_hooks.decls.pushdecl
4861     (build_decl (UNKNOWN_LOCATION,
4862                  TYPE_DECL, get_identifier ("complex long double"),
4863                  complex_long_double_type_node));
4864
4865   if (c_dialect_cxx ())
4866     /* For C++, make fileptr_type_node a distinct void * type until
4867        FILE type is defined.  */
4868     fileptr_type_node = build_variant_type_copy (ptr_type_node);
4869
4870   record_builtin_type (RID_VOID, NULL, void_type_node);
4871
4872   /* Set the TYPE_NAME for any variants that were built before
4873      record_builtin_type gave names to the built-in types. */
4874   {
4875     tree void_name = TYPE_NAME (void_type_node);
4876     TYPE_NAME (void_type_node) = NULL_TREE;
4877     TYPE_NAME (build_qualified_type (void_type_node, TYPE_QUAL_CONST))
4878       = void_name;
4879     TYPE_NAME (void_type_node) = void_name;
4880   }
4881
4882   /* This node must not be shared.  */
4883   void_zero_node = make_node (INTEGER_CST);
4884   TREE_TYPE (void_zero_node) = void_type_node;
4885
4886   void_list_node = build_void_list_node ();
4887
4888   /* Make a type to be the domain of a few array types
4889      whose domains don't really matter.
4890      200 is small enough that it always fits in size_t
4891      and large enough that it can hold most function names for the
4892      initializations of __FUNCTION__ and __PRETTY_FUNCTION__.  */
4893   array_domain_type = build_index_type (size_int (200));
4894
4895   /* Make a type for arrays of characters.
4896      With luck nothing will ever really depend on the length of this
4897      array type.  */
4898   char_array_type_node
4899     = build_array_type (char_type_node, array_domain_type);
4900
4901   /* Likewise for arrays of ints.  */
4902   int_array_type_node
4903     = build_array_type (integer_type_node, array_domain_type);
4904
4905   string_type_node = build_pointer_type (char_type_node);
4906   const_string_type_node
4907     = build_pointer_type (build_qualified_type
4908                           (char_type_node, TYPE_QUAL_CONST));
4909
4910   /* This is special for C++ so functions can be overloaded.  */
4911   wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE);
4912   wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node));
4913   wchar_type_size = TYPE_PRECISION (wchar_type_node);
4914   underlying_wchar_type_node = wchar_type_node;
4915   if (c_dialect_cxx ())
4916     {
4917       if (TYPE_UNSIGNED (wchar_type_node))
4918         wchar_type_node = make_unsigned_type (wchar_type_size);
4919       else
4920         wchar_type_node = make_signed_type (wchar_type_size);
4921       record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node);
4922     }
4923
4924   /* This is for wide string constants.  */
4925   wchar_array_type_node
4926     = build_array_type (wchar_type_node, array_domain_type);
4927
4928   /* Define 'char16_t'.  */
4929   char16_type_node = get_identifier (CHAR16_TYPE);
4930   char16_type_node = TREE_TYPE (identifier_global_value (char16_type_node));
4931   char16_type_size = TYPE_PRECISION (char16_type_node);
4932   if (c_dialect_cxx ())
4933     {
4934       char16_type_node = make_unsigned_type (char16_type_size);
4935
4936       if (cxx_dialect == cxx0x)
4937         record_builtin_type (RID_CHAR16, "char16_t", char16_type_node);
4938     }
4939
4940   /* This is for UTF-16 string constants.  */
4941   char16_array_type_node
4942     = build_array_type (char16_type_node, array_domain_type);
4943
4944   /* Define 'char32_t'.  */
4945   char32_type_node = get_identifier (CHAR32_TYPE);
4946   char32_type_node = TREE_TYPE (identifier_global_value (char32_type_node));
4947   char32_type_size = TYPE_PRECISION (char32_type_node);
4948   if (c_dialect_cxx ())
4949     {
4950       char32_type_node = make_unsigned_type (char32_type_size);
4951
4952       if (cxx_dialect == cxx0x)
4953         record_builtin_type (RID_CHAR32, "char32_t", char32_type_node);
4954     }
4955
4956   /* This is for UTF-32 string constants.  */
4957   char32_array_type_node
4958     = build_array_type (char32_type_node, array_domain_type);
4959
4960   wint_type_node =
4961     TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE)));
4962
4963   intmax_type_node =
4964     TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE)));
4965   uintmax_type_node =
4966     TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE)));
4967
4968   if (SIG_ATOMIC_TYPE)
4969     sig_atomic_type_node =
4970       TREE_TYPE (identifier_global_value (c_get_ident (SIG_ATOMIC_TYPE)));
4971   if (INT8_TYPE)
4972     int8_type_node =
4973       TREE_TYPE (identifier_global_value (c_get_ident (INT8_TYPE)));
4974   if (INT16_TYPE)
4975     int16_type_node =
4976       TREE_TYPE (identifier_global_value (c_get_ident (INT16_TYPE)));
4977   if (INT32_TYPE)
4978     int32_type_node =
4979       TREE_TYPE (identifier_global_value (c_get_ident (INT32_TYPE)));
4980   if (INT64_TYPE)
4981     int64_type_node =
4982       TREE_TYPE (identifier_global_value (c_get_ident (INT64_TYPE)));
4983   if (UINT8_TYPE)
4984     uint8_type_node =
4985       TREE_TYPE (identifier_global_value (c_get_ident (UINT8_TYPE)));
4986   if (UINT16_TYPE)
4987     uint16_type_node =
4988       TREE_TYPE (identifier_global_value (c_get_ident (UINT16_TYPE)));
4989   if (UINT32_TYPE)
4990     c_uint32_type_node =
4991       TREE_TYPE (identifier_global_value (c_get_ident (UINT32_TYPE)));
4992   if (UINT64_TYPE)
4993     c_uint64_type_node =
4994       TREE_TYPE (identifier_global_value (c_get_ident (UINT64_TYPE)));
4995   if (INT_LEAST8_TYPE)
4996     int_least8_type_node =
4997       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST8_TYPE)));
4998   if (INT_LEAST16_TYPE)
4999     int_least16_type_node =
5000       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST16_TYPE)));
5001   if (INT_LEAST32_TYPE)
5002     int_least32_type_node =
5003       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST32_TYPE)));
5004   if (INT_LEAST64_TYPE)
5005     int_least64_type_node =
5006       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST64_TYPE)));
5007   if (UINT_LEAST8_TYPE)
5008     uint_least8_type_node =
5009       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST8_TYPE)));
5010   if (UINT_LEAST16_TYPE)
5011     uint_least16_type_node =
5012       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST16_TYPE)));
5013   if (UINT_LEAST32_TYPE)
5014     uint_least32_type_node =
5015       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST32_TYPE)));
5016   if (UINT_LEAST64_TYPE)
5017     uint_least64_type_node =
5018       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST64_TYPE)));
5019   if (INT_FAST8_TYPE)
5020     int_fast8_type_node =
5021       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST8_TYPE)));
5022   if (INT_FAST16_TYPE)
5023     int_fast16_type_node =
5024       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST16_TYPE)));
5025   if (INT_FAST32_TYPE)
5026     int_fast32_type_node =
5027       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST32_TYPE)));
5028   if (INT_FAST64_TYPE)
5029     int_fast64_type_node =
5030       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST64_TYPE)));
5031   if (UINT_FAST8_TYPE)
5032     uint_fast8_type_node =
5033       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST8_TYPE)));
5034   if (UINT_FAST16_TYPE)
5035     uint_fast16_type_node =
5036       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST16_TYPE)));
5037   if (UINT_FAST32_TYPE)
5038     uint_fast32_type_node =
5039       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST32_TYPE)));
5040   if (UINT_FAST64_TYPE)
5041     uint_fast64_type_node =
5042       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST64_TYPE)));
5043   if (INTPTR_TYPE)
5044     intptr_type_node =
5045       TREE_TYPE (identifier_global_value (c_get_ident (INTPTR_TYPE)));
5046   if (UINTPTR_TYPE)
5047     uintptr_type_node =
5048       TREE_TYPE (identifier_global_value (c_get_ident (UINTPTR_TYPE)));
5049
5050   default_function_type = build_function_type (integer_type_node, NULL_TREE);
5051   ptrdiff_type_node
5052     = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE)));
5053   unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node);
5054
5055   lang_hooks.decls.pushdecl
5056     (build_decl (UNKNOWN_LOCATION,
5057                  TYPE_DECL, get_identifier ("__builtin_va_list"),
5058                  va_list_type_node));
5059 #ifdef TARGET_ENUM_VA_LIST
5060   {
5061     int l;
5062     const char *pname;
5063     tree ptype;
5064     for (l = 0; TARGET_ENUM_VA_LIST (l, &pname, &ptype); ++l)
5065       {
5066         lang_hooks.decls.pushdecl
5067           (build_decl (UNKNOWN_LOCATION,
5068                        TYPE_DECL, get_identifier (pname),
5069                        ptype));
5070
5071       }
5072   }
5073 #endif
5074
5075   if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
5076     {
5077       va_list_arg_type_node = va_list_ref_type_node =
5078         build_pointer_type (TREE_TYPE (va_list_type_node));
5079     }
5080   else
5081     {
5082       va_list_arg_type_node = va_list_type_node;
5083       va_list_ref_type_node = build_reference_type (va_list_type_node);
5084     }
5085
5086   if (!flag_preprocess_only)
5087     c_define_builtins (va_list_ref_type_node, va_list_arg_type_node);
5088
5089   main_identifier_node = get_identifier ("main");
5090
5091   /* Create the built-in __null node.  It is important that this is
5092      not shared.  */
5093   null_node = make_node (INTEGER_CST);
5094   TREE_TYPE (null_node) = c_common_type_for_size (POINTER_SIZE, 0);
5095
5096   /* Since builtin_types isn't gc'ed, don't export these nodes.  */
5097   memset (builtin_types, 0, sizeof (builtin_types));
5098 }
5099
5100 /* The number of named compound-literals generated thus far.  */
5101 static GTY(()) int compound_literal_number;
5102
5103 /* Set DECL_NAME for DECL, a VAR_DECL for a compound-literal.  */
5104
5105 void
5106 set_compound_literal_name (tree decl)
5107 {
5108   char *name;
5109   ASM_FORMAT_PRIVATE_NAME (name, "__compound_literal",
5110                            compound_literal_number);
5111   compound_literal_number++;
5112   DECL_NAME (decl) = get_identifier (name);
5113 }
5114
5115 tree
5116 build_va_arg (location_t loc, tree expr, tree type)
5117 {
5118   expr = build1 (VA_ARG_EXPR, type, expr);
5119   SET_EXPR_LOCATION (expr, loc);
5120   return expr;
5121 }
5122
5123
5124 /* Linked list of disabled built-in functions.  */
5125
5126 typedef struct disabled_builtin
5127 {
5128   const char *name;
5129   struct disabled_builtin *next;
5130 } disabled_builtin;
5131 static disabled_builtin *disabled_builtins = NULL;
5132
5133 static bool builtin_function_disabled_p (const char *);
5134
5135 /* Disable a built-in function specified by -fno-builtin-NAME.  If NAME
5136    begins with "__builtin_", give an error.  */
5137
5138 void
5139 disable_builtin_function (const char *name)
5140 {
5141   if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
5142     error ("cannot disable built-in function %qs", name);
5143   else
5144     {
5145       disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin);
5146       new_disabled_builtin->name = name;
5147       new_disabled_builtin->next = disabled_builtins;
5148       disabled_builtins = new_disabled_builtin;
5149     }
5150 }
5151
5152
5153 /* Return true if the built-in function NAME has been disabled, false
5154    otherwise.  */
5155
5156 static bool
5157 builtin_function_disabled_p (const char *name)
5158 {
5159   disabled_builtin *p;
5160   for (p = disabled_builtins; p != NULL; p = p->next)
5161     {
5162       if (strcmp (name, p->name) == 0)
5163         return true;
5164     }
5165   return false;
5166 }
5167
5168
5169 /* Worker for DEF_BUILTIN.
5170    Possibly define a builtin function with one or two names.
5171    Does not declare a non-__builtin_ function if flag_no_builtin, or if
5172    nonansi_p and flag_no_nonansi_builtin.  */
5173
5174 static void
5175 def_builtin_1 (enum built_in_function fncode,
5176                const char *name,
5177                enum built_in_class fnclass,
5178                tree fntype, tree libtype,
5179                bool both_p, bool fallback_p, bool nonansi_p,
5180                tree fnattrs, bool implicit_p)
5181 {
5182   tree decl;
5183   const char *libname;
5184
5185   if (fntype == error_mark_node)
5186     return;
5187
5188   gcc_assert ((!both_p && !fallback_p)
5189               || !strncmp (name, "__builtin_",
5190                            strlen ("__builtin_")));
5191
5192   libname = name + strlen ("__builtin_");
5193   decl = add_builtin_function (name, fntype, fncode, fnclass,
5194                                (fallback_p ? libname : NULL),
5195                                fnattrs);
5196   if (both_p
5197       && !flag_no_builtin && !builtin_function_disabled_p (libname)
5198       && !(nonansi_p && flag_no_nonansi_builtin))
5199     add_builtin_function (libname, libtype, fncode, fnclass,
5200                           NULL, fnattrs);
5201
5202   built_in_decls[(int) fncode] = decl;
5203   if (implicit_p)
5204     implicit_built_in_decls[(int) fncode] = decl;
5205 }
5206 \f
5207 /* Nonzero if the type T promotes to int.  This is (nearly) the
5208    integral promotions defined in ISO C99 6.3.1.1/2.  */
5209
5210 bool
5211 c_promoting_integer_type_p (const_tree t)
5212 {
5213   switch (TREE_CODE (t))
5214     {
5215     case INTEGER_TYPE:
5216       return (TYPE_MAIN_VARIANT (t) == char_type_node
5217               || TYPE_MAIN_VARIANT (t) == signed_char_type_node
5218               || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node
5219               || TYPE_MAIN_VARIANT (t) == short_integer_type_node
5220               || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node
5221               || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node));
5222
5223     case ENUMERAL_TYPE:
5224       /* ??? Technically all enumerations not larger than an int
5225          promote to an int.  But this is used along code paths
5226          that only want to notice a size change.  */
5227       return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node);
5228
5229     case BOOLEAN_TYPE:
5230       return 1;
5231
5232     default:
5233       return 0;
5234     }
5235 }
5236
5237 /* Return 1 if PARMS specifies a fixed number of parameters
5238    and none of their types is affected by default promotions.  */
5239
5240 int
5241 self_promoting_args_p (const_tree parms)
5242 {
5243   const_tree t;
5244   for (t = parms; t; t = TREE_CHAIN (t))
5245     {
5246       tree type = TREE_VALUE (t);
5247
5248       if (type == error_mark_node)
5249         continue;
5250
5251       if (TREE_CHAIN (t) == 0 && type != void_type_node)
5252         return 0;
5253
5254       if (type == 0)
5255         return 0;
5256
5257       if (TYPE_MAIN_VARIANT (type) == float_type_node)
5258         return 0;
5259
5260       if (c_promoting_integer_type_p (type))
5261         return 0;
5262     }
5263   return 1;
5264 }
5265
5266 /* Recursively remove any '*' or '&' operator from TYPE.  */
5267 tree
5268 strip_pointer_operator (tree t)
5269 {
5270   while (POINTER_TYPE_P (t))
5271     t = TREE_TYPE (t);
5272   return t;
5273 }
5274
5275 /* Recursively remove pointer or array type from TYPE. */
5276 tree
5277 strip_pointer_or_array_types (tree t)
5278 {
5279   while (TREE_CODE (t) == ARRAY_TYPE || POINTER_TYPE_P (t))
5280     t = TREE_TYPE (t);
5281   return t;
5282 }
5283
5284 /* Used to compare case labels.  K1 and K2 are actually tree nodes
5285    representing case labels, or NULL_TREE for a `default' label.
5286    Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
5287    K2, and 0 if K1 and K2 are equal.  */
5288
5289 int
5290 case_compare (splay_tree_key k1, splay_tree_key k2)
5291 {
5292   /* Consider a NULL key (such as arises with a `default' label) to be
5293      smaller than anything else.  */
5294   if (!k1)
5295     return k2 ? -1 : 0;
5296   else if (!k2)
5297     return k1 ? 1 : 0;
5298
5299   return tree_int_cst_compare ((tree) k1, (tree) k2);
5300 }
5301
5302 /* Process a case label, located at LOC, for the range LOW_VALUE
5303    ... HIGH_VALUE.  If LOW_VALUE and HIGH_VALUE are both NULL_TREE
5304    then this case label is actually a `default' label.  If only
5305    HIGH_VALUE is NULL_TREE, then case label was declared using the
5306    usual C/C++ syntax, rather than the GNU case range extension.
5307    CASES is a tree containing all the case ranges processed so far;
5308    COND is the condition for the switch-statement itself.  Returns the
5309    CASE_LABEL_EXPR created, or ERROR_MARK_NODE if no CASE_LABEL_EXPR
5310    is created.  */
5311
5312 tree
5313 c_add_case_label (location_t loc, splay_tree cases, tree cond, tree orig_type,
5314                   tree low_value, tree high_value)
5315 {
5316   tree type;
5317   tree label;
5318   tree case_label;
5319   splay_tree_node node;
5320
5321   /* Create the LABEL_DECL itself.  */
5322   label = create_artificial_label (loc);
5323
5324   /* If there was an error processing the switch condition, bail now
5325      before we get more confused.  */
5326   if (!cond || cond == error_mark_node)
5327     goto error_out;
5328
5329   if ((low_value && TREE_TYPE (low_value)
5330        && POINTER_TYPE_P (TREE_TYPE (low_value)))
5331       || (high_value && TREE_TYPE (high_value)
5332           && POINTER_TYPE_P (TREE_TYPE (high_value))))
5333     {
5334       error_at (loc, "pointers are not permitted as case values");
5335       goto error_out;
5336     }
5337
5338   /* Case ranges are a GNU extension.  */
5339   if (high_value)
5340     pedwarn (loc, OPT_pedantic,
5341              "range expressions in switch statements are non-standard");
5342
5343   type = TREE_TYPE (cond);
5344   if (low_value)
5345     {
5346       low_value = check_case_value (low_value);
5347       low_value = convert_and_check (type, low_value);
5348       if (low_value == error_mark_node)
5349         goto error_out;
5350     }
5351   if (high_value)
5352     {
5353       high_value = check_case_value (high_value);
5354       high_value = convert_and_check (type, high_value);
5355       if (high_value == error_mark_node)
5356         goto error_out;
5357     }
5358
5359   if (low_value && high_value)
5360     {
5361       /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
5362          really a case range, even though it was written that way.
5363          Remove the HIGH_VALUE to simplify later processing.  */
5364       if (tree_int_cst_equal (low_value, high_value))
5365         high_value = NULL_TREE;
5366       else if (!tree_int_cst_lt (low_value, high_value))
5367         warning_at (loc, 0, "empty range specified");
5368     }
5369
5370   /* See if the case is in range of the type of the original testing
5371      expression.  If both low_value and high_value are out of range,
5372      don't insert the case label and return NULL_TREE.  */
5373   if (low_value
5374       && !check_case_bounds (type, orig_type,
5375                              &low_value, high_value ? &high_value : NULL))
5376     return NULL_TREE;
5377
5378   /* Look up the LOW_VALUE in the table of case labels we already
5379      have.  */
5380   node = splay_tree_lookup (cases, (splay_tree_key) low_value);
5381   /* If there was not an exact match, check for overlapping ranges.
5382      There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
5383      that's a `default' label and the only overlap is an exact match.  */
5384   if (!node && (low_value || high_value))
5385     {
5386       splay_tree_node low_bound;
5387       splay_tree_node high_bound;
5388
5389       /* Even though there wasn't an exact match, there might be an
5390          overlap between this case range and another case range.
5391          Since we've (inductively) not allowed any overlapping case
5392          ranges, we simply need to find the greatest low case label
5393          that is smaller that LOW_VALUE, and the smallest low case
5394          label that is greater than LOW_VALUE.  If there is an overlap
5395          it will occur in one of these two ranges.  */
5396       low_bound = splay_tree_predecessor (cases,
5397                                           (splay_tree_key) low_value);
5398       high_bound = splay_tree_successor (cases,
5399                                          (splay_tree_key) low_value);
5400
5401       /* Check to see if the LOW_BOUND overlaps.  It is smaller than
5402          the LOW_VALUE, so there is no need to check unless the
5403          LOW_BOUND is in fact itself a case range.  */
5404       if (low_bound
5405           && CASE_HIGH ((tree) low_bound->value)
5406           && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
5407                                     low_value) >= 0)
5408         node = low_bound;
5409       /* Check to see if the HIGH_BOUND overlaps.  The low end of that
5410          range is bigger than the low end of the current range, so we
5411          are only interested if the current range is a real range, and
5412          not an ordinary case label.  */
5413       else if (high_bound
5414                && high_value
5415                && (tree_int_cst_compare ((tree) high_bound->key,
5416                                          high_value)
5417                    <= 0))
5418         node = high_bound;
5419     }
5420   /* If there was an overlap, issue an error.  */
5421   if (node)
5422     {
5423       tree duplicate = CASE_LABEL ((tree) node->value);
5424
5425       if (high_value)
5426         {
5427           error_at (loc, "duplicate (or overlapping) case value");
5428           error_at (DECL_SOURCE_LOCATION (duplicate),
5429                     "this is the first entry overlapping that value");
5430         }
5431       else if (low_value)
5432         {
5433           error_at (loc, "duplicate case value") ;
5434           error_at (DECL_SOURCE_LOCATION (duplicate), "previously used here");
5435         }
5436       else
5437         {
5438           error_at (loc, "multiple default labels in one switch");
5439           error_at (DECL_SOURCE_LOCATION (duplicate),
5440                     "this is the first default label");
5441         }
5442       goto error_out;
5443     }
5444
5445   /* Add a CASE_LABEL to the statement-tree.  */
5446   case_label = add_stmt (build_case_label (loc, low_value, high_value, label));
5447   /* Register this case label in the splay tree.  */
5448   splay_tree_insert (cases,
5449                      (splay_tree_key) low_value,
5450                      (splay_tree_value) case_label);
5451
5452   return case_label;
5453
5454  error_out:
5455   /* Add a label so that the back-end doesn't think that the beginning of
5456      the switch is unreachable.  Note that we do not add a case label, as
5457      that just leads to duplicates and thence to failure later on.  */
5458   if (!cases->root)
5459     {
5460       tree t = create_artificial_label (loc);
5461       add_stmt (build_stmt (loc, LABEL_EXPR, t));
5462     }
5463   return error_mark_node;
5464 }
5465
5466 /* Subroutines of c_do_switch_warnings, called via splay_tree_foreach.
5467    Used to verify that case values match up with enumerator values.  */
5468
5469 static void
5470 match_case_to_enum_1 (tree key, tree type, tree label)
5471 {
5472   char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1];
5473
5474   /* ??? Not working too hard to print the double-word value.
5475      Should perhaps be done with %lwd in the diagnostic routines?  */
5476   if (TREE_INT_CST_HIGH (key) == 0)
5477     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED,
5478               TREE_INT_CST_LOW (key));
5479   else if (!TYPE_UNSIGNED (type)
5480            && TREE_INT_CST_HIGH (key) == -1
5481            && TREE_INT_CST_LOW (key) != 0)
5482     snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED,
5483               -TREE_INT_CST_LOW (key));
5484   else
5485     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX,
5486               (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (key),
5487               (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (key));
5488
5489   if (TYPE_NAME (type) == 0)
5490     warning_at (DECL_SOURCE_LOCATION (CASE_LABEL (label)),
5491                 warn_switch ? OPT_Wswitch : OPT_Wswitch_enum,
5492                 "case value %qs not in enumerated type",
5493                 buf);
5494   else
5495     warning_at (DECL_SOURCE_LOCATION (CASE_LABEL (label)),
5496                 warn_switch ? OPT_Wswitch : OPT_Wswitch_enum,
5497                 "case value %qs not in enumerated type %qT",
5498                 buf, type);
5499 }
5500
5501 /* Subroutine of c_do_switch_warnings, called via splay_tree_foreach.
5502    Used to verify that case values match up with enumerator values.  */
5503
5504 static int
5505 match_case_to_enum (splay_tree_node node, void *data)
5506 {
5507   tree label = (tree) node->value;
5508   tree type = (tree) data;
5509
5510   /* Skip default case.  */
5511   if (!CASE_LOW (label))
5512     return 0;
5513
5514   /* If CASE_LOW_SEEN is not set, that means CASE_LOW did not appear
5515      when we did our enum->case scan.  Reset our scratch bit after.  */
5516   if (!CASE_LOW_SEEN (label))
5517     match_case_to_enum_1 (CASE_LOW (label), type, label);
5518   else
5519     CASE_LOW_SEEN (label) = 0;
5520
5521   /* If CASE_HIGH is non-null, we have a range.  If CASE_HIGH_SEEN is
5522      not set, that means that CASE_HIGH did not appear when we did our
5523      enum->case scan.  Reset our scratch bit after.  */
5524   if (CASE_HIGH (label))
5525     {
5526       if (!CASE_HIGH_SEEN (label))
5527         match_case_to_enum_1 (CASE_HIGH (label), type, label);
5528       else
5529         CASE_HIGH_SEEN (label) = 0;
5530     }
5531
5532   return 0;
5533 }
5534
5535 /* Handle -Wswitch*.  Called from the front end after parsing the
5536    switch construct.  */
5537 /* ??? Should probably be somewhere generic, since other languages
5538    besides C and C++ would want this.  At the moment, however, C/C++
5539    are the only tree-ssa languages that support enumerations at all,
5540    so the point is moot.  */
5541
5542 void
5543 c_do_switch_warnings (splay_tree cases, location_t switch_location,
5544                       tree type, tree cond)
5545 {
5546   splay_tree_node default_node;
5547   splay_tree_node node;
5548   tree chain;
5549
5550   if (!warn_switch && !warn_switch_enum && !warn_switch_default)
5551     return;
5552
5553   default_node = splay_tree_lookup (cases, (splay_tree_key) NULL);
5554   if (!default_node)
5555     warning_at (switch_location, OPT_Wswitch_default,
5556                 "switch missing default case");
5557
5558   /* From here on, we only care about about enumerated types.  */
5559   if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
5560     return;
5561
5562   /* From here on, we only care about -Wswitch and -Wswitch-enum.  */
5563   if (!warn_switch_enum && !warn_switch)
5564     return;
5565
5566   /* Check the cases.  Warn about case values which are not members of
5567      the enumerated type.  For -Wswitch-enum, or for -Wswitch when
5568      there is no default case, check that exactly all enumeration
5569      literals are covered by the cases.  */
5570
5571   /* Clearing COND if it is not an integer constant simplifies
5572      the tests inside the loop below.  */
5573   if (TREE_CODE (cond) != INTEGER_CST)
5574     cond = NULL_TREE;
5575
5576   /* The time complexity here is O(N*lg(N)) worst case, but for the
5577       common case of monotonically increasing enumerators, it is
5578       O(N), since the nature of the splay tree will keep the next
5579       element adjacent to the root at all times.  */
5580
5581   for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain))
5582     {
5583       tree value = TREE_VALUE (chain);
5584       if (TREE_CODE (value) == CONST_DECL)
5585         value = DECL_INITIAL (value);
5586       node = splay_tree_lookup (cases, (splay_tree_key) value);
5587       if (node)
5588         {
5589           /* Mark the CASE_LOW part of the case entry as seen.  */
5590           tree label = (tree) node->value;
5591           CASE_LOW_SEEN (label) = 1;
5592           continue;
5593         }
5594
5595       /* Even though there wasn't an exact match, there might be a
5596          case range which includes the enumerator's value.  */
5597       node = splay_tree_predecessor (cases, (splay_tree_key) value);
5598       if (node && CASE_HIGH ((tree) node->value))
5599         {
5600           tree label = (tree) node->value;
5601           int cmp = tree_int_cst_compare (CASE_HIGH (label), value);
5602           if (cmp >= 0)
5603             {
5604               /* If we match the upper bound exactly, mark the CASE_HIGH
5605                  part of the case entry as seen.  */
5606               if (cmp == 0)
5607                 CASE_HIGH_SEEN (label) = 1;
5608               continue;
5609             }
5610         }
5611
5612       /* We've now determined that this enumerated literal isn't
5613          handled by the case labels of the switch statement.  */
5614
5615       /* If the switch expression is a constant, we only really care
5616          about whether that constant is handled by the switch.  */
5617       if (cond && tree_int_cst_compare (cond, value))
5618         continue;
5619
5620       /* If there is a default_node, the only relevant option is
5621          Wswitch-enum.  Otherwise, if both are enabled then we prefer
5622          to warn using -Wswitch because -Wswitch is enabled by -Wall
5623          while -Wswitch-enum is explicit.  */
5624       warning_at (switch_location,
5625                   (default_node || !warn_switch
5626                    ? OPT_Wswitch_enum
5627                    : OPT_Wswitch),
5628                   "enumeration value %qE not handled in switch",
5629                   TREE_PURPOSE (chain));
5630     }
5631
5632   /* Warn if there are case expressions that don't correspond to
5633      enumerators.  This can occur since C and C++ don't enforce
5634      type-checking of assignments to enumeration variables.
5635
5636      The time complexity here is now always O(N) worst case, since
5637      we should have marked both the lower bound and upper bound of
5638      every disjoint case label, with CASE_LOW_SEEN and CASE_HIGH_SEEN
5639      above.  This scan also resets those fields.  */
5640
5641   splay_tree_foreach (cases, match_case_to_enum, type);
5642 }
5643
5644 /* Finish an expression taking the address of LABEL (an
5645    IDENTIFIER_NODE).  Returns an expression for the address.
5646
5647    LOC is the location for the expression returned.  */
5648
5649 tree
5650 finish_label_address_expr (tree label, location_t loc)
5651 {
5652   tree result;
5653
5654   pedwarn (input_location, OPT_pedantic, "taking the address of a label is non-standard");
5655
5656   if (label == error_mark_node)
5657     return error_mark_node;
5658
5659   label = lookup_label (label);
5660   if (label == NULL_TREE)
5661     result = null_pointer_node;
5662   else
5663     {
5664       TREE_USED (label) = 1;
5665       result = build1 (ADDR_EXPR, ptr_type_node, label);
5666       /* The current function is not necessarily uninlinable.
5667          Computed gotos are incompatible with inlining, but the value
5668          here could be used only in a diagnostic, for example.  */
5669       protected_set_expr_location (result, loc);
5670     }
5671
5672   return result;
5673 }
5674 \f
5675
5676 /* Given a boolean expression ARG, return a tree representing an increment
5677    or decrement (as indicated by CODE) of ARG.  The front end must check for
5678    invalid cases (e.g., decrement in C++).  */
5679 tree
5680 boolean_increment (enum tree_code code, tree arg)
5681 {
5682   tree val;
5683   tree true_res = build_int_cst (TREE_TYPE (arg), 1);
5684
5685   arg = stabilize_reference (arg);
5686   switch (code)
5687     {
5688     case PREINCREMENT_EXPR:
5689       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
5690       break;
5691     case POSTINCREMENT_EXPR:
5692       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
5693       arg = save_expr (arg);
5694       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
5695       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
5696       break;
5697     case PREDECREMENT_EXPR:
5698       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
5699                     invert_truthvalue_loc (input_location, arg));
5700       break;
5701     case POSTDECREMENT_EXPR:
5702       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
5703                     invert_truthvalue_loc (input_location, arg));
5704       arg = save_expr (arg);
5705       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
5706       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
5707       break;
5708     default:
5709       gcc_unreachable ();
5710     }
5711   TREE_SIDE_EFFECTS (val) = 1;
5712   return val;
5713 }
5714 \f
5715 /* Built-in macros for stddef.h and stdint.h, that require macros
5716    defined in this file.  */
5717 void
5718 c_stddef_cpp_builtins(void)
5719 {
5720   builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0);
5721   builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0);
5722   builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0);
5723   builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0);
5724   builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0);
5725   builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0);
5726   builtin_define_with_value ("__CHAR16_TYPE__", CHAR16_TYPE, 0);
5727   builtin_define_with_value ("__CHAR32_TYPE__", CHAR32_TYPE, 0);
5728   if (SIG_ATOMIC_TYPE)
5729     builtin_define_with_value ("__SIG_ATOMIC_TYPE__", SIG_ATOMIC_TYPE, 0);
5730   if (INT8_TYPE)
5731     builtin_define_with_value ("__INT8_TYPE__", INT8_TYPE, 0);
5732   if (INT16_TYPE)
5733     builtin_define_with_value ("__INT16_TYPE__", INT16_TYPE, 0);
5734   if (INT32_TYPE)
5735     builtin_define_with_value ("__INT32_TYPE__", INT32_TYPE, 0);
5736   if (INT64_TYPE)
5737     builtin_define_with_value ("__INT64_TYPE__", INT64_TYPE, 0);
5738   if (UINT8_TYPE)
5739     builtin_define_with_value ("__UINT8_TYPE__", UINT8_TYPE, 0);
5740   if (UINT16_TYPE)
5741     builtin_define_with_value ("__UINT16_TYPE__", UINT16_TYPE, 0);
5742   if (UINT32_TYPE)
5743     builtin_define_with_value ("__UINT32_TYPE__", UINT32_TYPE, 0);
5744   if (UINT64_TYPE)
5745     builtin_define_with_value ("__UINT64_TYPE__", UINT64_TYPE, 0);
5746   if (INT_LEAST8_TYPE)
5747     builtin_define_with_value ("__INT_LEAST8_TYPE__", INT_LEAST8_TYPE, 0);
5748   if (INT_LEAST16_TYPE)
5749     builtin_define_with_value ("__INT_LEAST16_TYPE__", INT_LEAST16_TYPE, 0);
5750   if (INT_LEAST32_TYPE)
5751     builtin_define_with_value ("__INT_LEAST32_TYPE__", INT_LEAST32_TYPE, 0);
5752   if (INT_LEAST64_TYPE)
5753     builtin_define_with_value ("__INT_LEAST64_TYPE__", INT_LEAST64_TYPE, 0);
5754   if (UINT_LEAST8_TYPE)
5755     builtin_define_with_value ("__UINT_LEAST8_TYPE__", UINT_LEAST8_TYPE, 0);
5756   if (UINT_LEAST16_TYPE)
5757     builtin_define_with_value ("__UINT_LEAST16_TYPE__", UINT_LEAST16_TYPE, 0);
5758   if (UINT_LEAST32_TYPE)
5759     builtin_define_with_value ("__UINT_LEAST32_TYPE__", UINT_LEAST32_TYPE, 0);
5760   if (UINT_LEAST64_TYPE)
5761     builtin_define_with_value ("__UINT_LEAST64_TYPE__", UINT_LEAST64_TYPE, 0);
5762   if (INT_FAST8_TYPE)
5763     builtin_define_with_value ("__INT_FAST8_TYPE__", INT_FAST8_TYPE, 0);
5764   if (INT_FAST16_TYPE)
5765     builtin_define_with_value ("__INT_FAST16_TYPE__", INT_FAST16_TYPE, 0);
5766   if (INT_FAST32_TYPE)
5767     builtin_define_with_value ("__INT_FAST32_TYPE__", INT_FAST32_TYPE, 0);
5768   if (INT_FAST64_TYPE)
5769     builtin_define_with_value ("__INT_FAST64_TYPE__", INT_FAST64_TYPE, 0);
5770   if (UINT_FAST8_TYPE)
5771     builtin_define_with_value ("__UINT_FAST8_TYPE__", UINT_FAST8_TYPE, 0);
5772   if (UINT_FAST16_TYPE)
5773     builtin_define_with_value ("__UINT_FAST16_TYPE__", UINT_FAST16_TYPE, 0);
5774   if (UINT_FAST32_TYPE)
5775     builtin_define_with_value ("__UINT_FAST32_TYPE__", UINT_FAST32_TYPE, 0);
5776   if (UINT_FAST64_TYPE)
5777     builtin_define_with_value ("__UINT_FAST64_TYPE__", UINT_FAST64_TYPE, 0);
5778   if (INTPTR_TYPE)
5779     builtin_define_with_value ("__INTPTR_TYPE__", INTPTR_TYPE, 0);
5780   if (UINTPTR_TYPE)
5781     builtin_define_with_value ("__UINTPTR_TYPE__", UINTPTR_TYPE, 0);
5782 }
5783
5784 static void
5785 c_init_attributes (void)
5786 {
5787   /* Fill in the built_in_attributes array.  */
5788 #define DEF_ATTR_NULL_TREE(ENUM)                                \
5789   built_in_attributes[(int) ENUM] = NULL_TREE;
5790 #define DEF_ATTR_INT(ENUM, VALUE)                               \
5791   built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
5792 #define DEF_ATTR_IDENT(ENUM, STRING)                            \
5793   built_in_attributes[(int) ENUM] = get_identifier (STRING);
5794 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
5795   built_in_attributes[(int) ENUM]                       \
5796     = tree_cons (built_in_attributes[(int) PURPOSE],    \
5797                  built_in_attributes[(int) VALUE],      \
5798                  built_in_attributes[(int) CHAIN]);
5799 #include "builtin-attrs.def"
5800 #undef DEF_ATTR_NULL_TREE
5801 #undef DEF_ATTR_INT
5802 #undef DEF_ATTR_IDENT
5803 #undef DEF_ATTR_TREE_LIST
5804 }
5805
5806 /* Attribute handlers common to C front ends.  */
5807
5808 /* Handle a "packed" attribute; arguments as in
5809    struct attribute_spec.handler.  */
5810
5811 static tree
5812 handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5813                          int flags, bool *no_add_attrs)
5814 {
5815   if (TYPE_P (*node))
5816     {
5817       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5818         *node = build_variant_type_copy (*node);
5819       TYPE_PACKED (*node) = 1;
5820     }
5821   else if (TREE_CODE (*node) == FIELD_DECL)
5822     {
5823       if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT
5824           /* Still pack bitfields.  */
5825           && ! DECL_INITIAL (*node))
5826         warning (OPT_Wattributes,
5827                  "%qE attribute ignored for field of type %qT",
5828                  name, TREE_TYPE (*node));
5829       else
5830         DECL_PACKED (*node) = 1;
5831     }
5832   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
5833      used for DECL_REGISTER.  It wouldn't mean anything anyway.
5834      We can't set DECL_PACKED on the type of a TYPE_DECL, because
5835      that changes what the typedef is typing.  */
5836   else
5837     {
5838       warning (OPT_Wattributes, "%qE attribute ignored", name);
5839       *no_add_attrs = true;
5840     }
5841
5842   return NULL_TREE;
5843 }
5844
5845 /* Handle a "nocommon" attribute; arguments as in
5846    struct attribute_spec.handler.  */
5847
5848 static tree
5849 handle_nocommon_attribute (tree *node, tree name,
5850                            tree ARG_UNUSED (args),
5851                            int ARG_UNUSED (flags), bool *no_add_attrs)
5852 {
5853   if (TREE_CODE (*node) == VAR_DECL)
5854     DECL_COMMON (*node) = 0;
5855   else
5856     {
5857       warning (OPT_Wattributes, "%qE attribute ignored", name);
5858       *no_add_attrs = true;
5859     }
5860
5861   return NULL_TREE;
5862 }
5863
5864 /* Handle a "common" attribute; arguments as in
5865    struct attribute_spec.handler.  */
5866
5867 static tree
5868 handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5869                          int ARG_UNUSED (flags), bool *no_add_attrs)
5870 {
5871   if (TREE_CODE (*node) == VAR_DECL)
5872     DECL_COMMON (*node) = 1;
5873   else
5874     {
5875       warning (OPT_Wattributes, "%qE attribute ignored", name);
5876       *no_add_attrs = true;
5877     }
5878
5879   return NULL_TREE;
5880 }
5881
5882 /* Handle a "noreturn" attribute; arguments as in
5883    struct attribute_spec.handler.  */
5884
5885 static tree
5886 handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5887                            int ARG_UNUSED (flags), bool *no_add_attrs)
5888 {
5889   tree type = TREE_TYPE (*node);
5890
5891   /* See FIXME comment in c_common_attribute_table.  */
5892   if (TREE_CODE (*node) == FUNCTION_DECL)
5893     TREE_THIS_VOLATILE (*node) = 1;
5894   else if (TREE_CODE (type) == POINTER_TYPE
5895            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
5896     TREE_TYPE (*node)
5897       = build_pointer_type
5898         (build_type_variant (TREE_TYPE (type),
5899                              TYPE_READONLY (TREE_TYPE (type)), 1));
5900   else
5901     {
5902       warning (OPT_Wattributes, "%qE attribute ignored", name);
5903       *no_add_attrs = true;
5904     }
5905
5906   return NULL_TREE;
5907 }
5908
5909 /* Handle a "hot" and attribute; arguments as in
5910    struct attribute_spec.handler.  */
5911
5912 static tree
5913 handle_hot_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5914                       int ARG_UNUSED (flags), bool *no_add_attrs)
5915 {
5916   if (TREE_CODE (*node) == FUNCTION_DECL)
5917     {
5918       if (lookup_attribute ("cold", DECL_ATTRIBUTES (*node)) != NULL)
5919         {
5920           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
5921                    name, "cold");
5922           *no_add_attrs = true;
5923         }
5924       /* Most of the rest of the hot processing is done later with
5925          lookup_attribute.  */
5926     }
5927   else
5928     {
5929       warning (OPT_Wattributes, "%qE attribute ignored", name);
5930       *no_add_attrs = true;
5931     }
5932
5933   return NULL_TREE;
5934 }
5935 /* Handle a "cold" and attribute; arguments as in
5936    struct attribute_spec.handler.  */
5937
5938 static tree
5939 handle_cold_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5940                        int ARG_UNUSED (flags), bool *no_add_attrs)
5941 {
5942   if (TREE_CODE (*node) == FUNCTION_DECL)
5943     {
5944       if (lookup_attribute ("hot", DECL_ATTRIBUTES (*node)) != NULL)
5945         {
5946           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
5947                    name, "hot");
5948           *no_add_attrs = true;
5949         }
5950       /* Most of the rest of the cold processing is done later with
5951          lookup_attribute.  */
5952     }
5953   else
5954     {
5955       warning (OPT_Wattributes, "%qE attribute ignored", name);
5956       *no_add_attrs = true;
5957     }
5958
5959   return NULL_TREE;
5960 }
5961
5962 /* Handle a "noinline" attribute; arguments as in
5963    struct attribute_spec.handler.  */
5964
5965 static tree
5966 handle_noinline_attribute (tree *node, tree name,
5967                            tree ARG_UNUSED (args),
5968                            int ARG_UNUSED (flags), bool *no_add_attrs)
5969 {
5970   if (TREE_CODE (*node) == FUNCTION_DECL)
5971     DECL_UNINLINABLE (*node) = 1;
5972   else
5973     {
5974       warning (OPT_Wattributes, "%qE attribute ignored", name);
5975       *no_add_attrs = true;
5976     }
5977
5978   return NULL_TREE;
5979 }
5980
5981 /* Handle a "noclone" attribute; arguments as in
5982    struct attribute_spec.handler.  */
5983
5984 static tree
5985 handle_noclone_attribute (tree *node, tree name,
5986                           tree ARG_UNUSED (args),
5987                           int ARG_UNUSED (flags), bool *no_add_attrs)
5988 {
5989   if (TREE_CODE (*node) != FUNCTION_DECL)
5990     {
5991       warning (OPT_Wattributes, "%qE attribute ignored", name);
5992       *no_add_attrs = true;
5993     }
5994
5995   return NULL_TREE;
5996 }
5997
5998 /* Handle a "always_inline" attribute; arguments as in
5999    struct attribute_spec.handler.  */
6000
6001 static tree
6002 handle_always_inline_attribute (tree *node, tree name,
6003                                 tree ARG_UNUSED (args),
6004                                 int ARG_UNUSED (flags),
6005                                 bool *no_add_attrs)
6006 {
6007   if (TREE_CODE (*node) == FUNCTION_DECL)
6008     {
6009       /* Set the attribute and mark it for disregarding inline
6010          limits.  */
6011       DECL_DISREGARD_INLINE_LIMITS (*node) = 1;
6012     }
6013   else
6014     {
6015       warning (OPT_Wattributes, "%qE attribute ignored", name);
6016       *no_add_attrs = true;
6017     }
6018
6019   return NULL_TREE;
6020 }
6021
6022 /* Handle a "gnu_inline" attribute; arguments as in
6023    struct attribute_spec.handler.  */
6024
6025 static tree
6026 handle_gnu_inline_attribute (tree *node, tree name,
6027                              tree ARG_UNUSED (args),
6028                              int ARG_UNUSED (flags),
6029                              bool *no_add_attrs)
6030 {
6031   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
6032     {
6033       /* Do nothing else, just set the attribute.  We'll get at
6034          it later with lookup_attribute.  */
6035     }
6036   else
6037     {
6038       warning (OPT_Wattributes, "%qE attribute ignored", name);
6039       *no_add_attrs = true;
6040     }
6041
6042   return NULL_TREE;
6043 }
6044
6045 /* Handle an "artificial" attribute; arguments as in
6046    struct attribute_spec.handler.  */
6047
6048 static tree
6049 handle_artificial_attribute (tree *node, tree name,
6050                              tree ARG_UNUSED (args),
6051                              int ARG_UNUSED (flags),
6052                              bool *no_add_attrs)
6053 {
6054   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
6055     {
6056       /* Do nothing else, just set the attribute.  We'll get at
6057          it later with lookup_attribute.  */
6058     }
6059   else
6060     {
6061       warning (OPT_Wattributes, "%qE attribute ignored", name);
6062       *no_add_attrs = true;
6063     }
6064
6065   return NULL_TREE;
6066 }
6067
6068 /* Handle a "flatten" attribute; arguments as in
6069    struct attribute_spec.handler.  */
6070
6071 static tree
6072 handle_flatten_attribute (tree *node, tree name,
6073                           tree args ATTRIBUTE_UNUSED,
6074                           int flags ATTRIBUTE_UNUSED, bool *no_add_attrs)
6075 {
6076   if (TREE_CODE (*node) == FUNCTION_DECL)
6077     /* Do nothing else, just set the attribute.  We'll get at
6078        it later with lookup_attribute.  */
6079     ;
6080   else
6081     {
6082       warning (OPT_Wattributes, "%qE attribute ignored", name);
6083       *no_add_attrs = true;
6084     }
6085
6086   return NULL_TREE;
6087 }
6088
6089 /* Handle a "warning" or "error" attribute; arguments as in
6090    struct attribute_spec.handler.  */
6091
6092 static tree
6093 handle_error_attribute (tree *node, tree name, tree args,
6094                         int ARG_UNUSED (flags), bool *no_add_attrs)
6095 {
6096   if (TREE_CODE (*node) == FUNCTION_DECL
6097       || TREE_CODE (TREE_VALUE (args)) == STRING_CST)
6098     /* Do nothing else, just set the attribute.  We'll get at
6099        it later with lookup_attribute.  */
6100     ;
6101   else
6102     {
6103       warning (OPT_Wattributes, "%qE attribute ignored", name);
6104       *no_add_attrs = true;
6105     }
6106
6107   return NULL_TREE;
6108 }
6109
6110 /* Handle a "used" attribute; arguments as in
6111    struct attribute_spec.handler.  */
6112
6113 static tree
6114 handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
6115                        int ARG_UNUSED (flags), bool *no_add_attrs)
6116 {
6117   tree node = *pnode;
6118
6119   if (TREE_CODE (node) == FUNCTION_DECL
6120       || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node)))
6121     {
6122       TREE_USED (node) = 1;
6123       DECL_PRESERVE_P (node) = 1;
6124     }
6125   else
6126     {
6127       warning (OPT_Wattributes, "%qE attribute ignored", name);
6128       *no_add_attrs = true;
6129     }
6130
6131   return NULL_TREE;
6132 }
6133
6134 /* Handle a "unused" attribute; arguments as in
6135    struct attribute_spec.handler.  */
6136
6137 static tree
6138 handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6139                          int flags, bool *no_add_attrs)
6140 {
6141   if (DECL_P (*node))
6142     {
6143       tree decl = *node;
6144
6145       if (TREE_CODE (decl) == PARM_DECL
6146           || TREE_CODE (decl) == VAR_DECL
6147           || TREE_CODE (decl) == FUNCTION_DECL
6148           || TREE_CODE (decl) == LABEL_DECL
6149           || TREE_CODE (decl) == TYPE_DECL)
6150         TREE_USED (decl) = 1;
6151       else
6152         {
6153           warning (OPT_Wattributes, "%qE attribute ignored", name);
6154           *no_add_attrs = true;
6155         }
6156     }
6157   else
6158     {
6159       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6160         *node = build_variant_type_copy (*node);
6161       TREE_USED (*node) = 1;
6162     }
6163
6164   return NULL_TREE;
6165 }
6166
6167 /* Handle a "externally_visible" attribute; arguments as in
6168    struct attribute_spec.handler.  */
6169
6170 static tree
6171 handle_externally_visible_attribute (tree *pnode, tree name,
6172                                      tree ARG_UNUSED (args),
6173                                      int ARG_UNUSED (flags),
6174                                      bool *no_add_attrs)
6175 {
6176   tree node = *pnode;
6177
6178   if (TREE_CODE (node) == FUNCTION_DECL || TREE_CODE (node) == VAR_DECL)
6179     {
6180       if ((!TREE_STATIC (node) && TREE_CODE (node) != FUNCTION_DECL
6181            && !DECL_EXTERNAL (node)) || !TREE_PUBLIC (node))
6182         {
6183           warning (OPT_Wattributes,
6184                    "%qE attribute have effect only on public objects", name);
6185           *no_add_attrs = true;
6186         }
6187     }
6188   else
6189     {
6190       warning (OPT_Wattributes, "%qE attribute ignored", name);
6191       *no_add_attrs = true;
6192     }
6193
6194   return NULL_TREE;
6195 }
6196
6197 /* Handle a "const" attribute; arguments as in
6198    struct attribute_spec.handler.  */
6199
6200 static tree
6201 handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6202                         int ARG_UNUSED (flags), bool *no_add_attrs)
6203 {
6204   tree type = TREE_TYPE (*node);
6205
6206   /* See FIXME comment on noreturn in c_common_attribute_table.  */
6207   if (TREE_CODE (*node) == FUNCTION_DECL)
6208     TREE_READONLY (*node) = 1;
6209   else if (TREE_CODE (type) == POINTER_TYPE
6210            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
6211     TREE_TYPE (*node)
6212       = build_pointer_type
6213         (build_type_variant (TREE_TYPE (type), 1,
6214                              TREE_THIS_VOLATILE (TREE_TYPE (type))));
6215   else
6216     {
6217       warning (OPT_Wattributes, "%qE attribute ignored", name);
6218       *no_add_attrs = true;
6219     }
6220
6221   return NULL_TREE;
6222 }
6223
6224 /* Handle a "transparent_union" attribute; arguments as in
6225    struct attribute_spec.handler.  */
6226
6227 static tree
6228 handle_transparent_union_attribute (tree *node, tree name,
6229                                     tree ARG_UNUSED (args), int flags,
6230                                     bool *no_add_attrs)
6231 {
6232   tree type;
6233
6234   *no_add_attrs = true;
6235
6236   if (TREE_CODE (*node) == TYPE_DECL)
6237     node = &TREE_TYPE (*node);
6238   type = *node;
6239
6240   if (TREE_CODE (type) == UNION_TYPE)
6241     {
6242       /* When IN_PLACE is set, leave the check for FIELDS and MODE to
6243          the code in finish_struct.  */
6244       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6245         {
6246           if (TYPE_FIELDS (type) == NULL_TREE
6247               || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type)))
6248             goto ignored;
6249
6250           /* A type variant isn't good enough, since we don't a cast
6251              to such a type removed as a no-op.  */
6252           *node = type = build_duplicate_type (type);
6253         }
6254
6255       TYPE_TRANSPARENT_AGGR (type) = 1;
6256       return NULL_TREE;
6257     }
6258
6259  ignored:
6260   warning (OPT_Wattributes, "%qE attribute ignored", name);
6261   return NULL_TREE;
6262 }
6263
6264 /* Subroutine of handle_{con,de}structor_attribute.  Evaluate ARGS to
6265    get the requested priority for a constructor or destructor,
6266    possibly issuing diagnostics for invalid or reserved
6267    priorities.  */
6268
6269 static priority_type
6270 get_priority (tree args, bool is_destructor)
6271 {
6272   HOST_WIDE_INT pri;
6273   tree arg;
6274
6275   if (!args)
6276     return DEFAULT_INIT_PRIORITY;
6277
6278   if (!SUPPORTS_INIT_PRIORITY)
6279     {
6280       if (is_destructor)
6281         error ("destructor priorities are not supported");
6282       else
6283         error ("constructor priorities are not supported");
6284       return DEFAULT_INIT_PRIORITY;
6285     }
6286
6287   arg = TREE_VALUE (args);
6288   if (!host_integerp (arg, /*pos=*/0)
6289       || !INTEGRAL_TYPE_P (TREE_TYPE (arg)))
6290     goto invalid;
6291
6292   pri = tree_low_cst (TREE_VALUE (args), /*pos=*/0);
6293   if (pri < 0 || pri > MAX_INIT_PRIORITY)
6294     goto invalid;
6295
6296   if (pri <= MAX_RESERVED_INIT_PRIORITY)
6297     {
6298       if (is_destructor)
6299         warning (0,
6300                  "destructor priorities from 0 to %d are reserved "
6301                  "for the implementation",
6302                  MAX_RESERVED_INIT_PRIORITY);
6303       else
6304         warning (0,
6305                  "constructor priorities from 0 to %d are reserved "
6306                  "for the implementation",
6307                  MAX_RESERVED_INIT_PRIORITY);
6308     }
6309   return pri;
6310
6311  invalid:
6312   if (is_destructor)
6313     error ("destructor priorities must be integers from 0 to %d inclusive",
6314            MAX_INIT_PRIORITY);
6315   else
6316     error ("constructor priorities must be integers from 0 to %d inclusive",
6317            MAX_INIT_PRIORITY);
6318   return DEFAULT_INIT_PRIORITY;
6319 }
6320
6321 /* Handle a "constructor" attribute; arguments as in
6322    struct attribute_spec.handler.  */
6323
6324 static tree
6325 handle_constructor_attribute (tree *node, tree name, tree args,
6326                               int ARG_UNUSED (flags),
6327                               bool *no_add_attrs)
6328 {
6329   tree decl = *node;
6330   tree type = TREE_TYPE (decl);
6331
6332   if (TREE_CODE (decl) == FUNCTION_DECL
6333       && TREE_CODE (type) == FUNCTION_TYPE
6334       && decl_function_context (decl) == 0)
6335     {
6336       priority_type priority;
6337       DECL_STATIC_CONSTRUCTOR (decl) = 1;
6338       priority = get_priority (args, /*is_destructor=*/false);
6339       SET_DECL_INIT_PRIORITY (decl, priority);
6340       TREE_USED (decl) = 1;
6341     }
6342   else
6343     {
6344       warning (OPT_Wattributes, "%qE attribute ignored", name);
6345       *no_add_attrs = true;
6346     }
6347
6348   return NULL_TREE;
6349 }
6350
6351 /* Handle a "destructor" attribute; arguments as in
6352    struct attribute_spec.handler.  */
6353
6354 static tree
6355 handle_destructor_attribute (tree *node, tree name, tree args,
6356                              int ARG_UNUSED (flags),
6357                              bool *no_add_attrs)
6358 {
6359   tree decl = *node;
6360   tree type = TREE_TYPE (decl);
6361
6362   if (TREE_CODE (decl) == FUNCTION_DECL
6363       && TREE_CODE (type) == FUNCTION_TYPE
6364       && decl_function_context (decl) == 0)
6365     {
6366       priority_type priority;
6367       DECL_STATIC_DESTRUCTOR (decl) = 1;
6368       priority = get_priority (args, /*is_destructor=*/true);
6369       SET_DECL_FINI_PRIORITY (decl, priority);
6370       TREE_USED (decl) = 1;
6371     }
6372   else
6373     {
6374       warning (OPT_Wattributes, "%qE attribute ignored", name);
6375       *no_add_attrs = true;
6376     }
6377
6378   return NULL_TREE;
6379 }
6380
6381 /* Handle a "mode" attribute; arguments as in
6382    struct attribute_spec.handler.  */
6383
6384 static tree
6385 handle_mode_attribute (tree *node, tree name, tree args,
6386                        int ARG_UNUSED (flags), bool *no_add_attrs)
6387 {
6388   tree type = *node;
6389   tree ident = TREE_VALUE (args);
6390
6391   *no_add_attrs = true;
6392
6393   if (TREE_CODE (ident) != IDENTIFIER_NODE)
6394     warning (OPT_Wattributes, "%qE attribute ignored", name);
6395   else
6396     {
6397       int j;
6398       const char *p = IDENTIFIER_POINTER (ident);
6399       int len = strlen (p);
6400       enum machine_mode mode = VOIDmode;
6401       tree typefm;
6402       bool valid_mode;
6403
6404       if (len > 4 && p[0] == '_' && p[1] == '_'
6405           && p[len - 1] == '_' && p[len - 2] == '_')
6406         {
6407           char *newp = (char *) alloca (len - 1);
6408
6409           strcpy (newp, &p[2]);
6410           newp[len - 4] = '\0';
6411           p = newp;
6412         }
6413
6414       /* Change this type to have a type with the specified mode.
6415          First check for the special modes.  */
6416       if (!strcmp (p, "byte"))
6417         mode = byte_mode;
6418       else if (!strcmp (p, "word"))
6419         mode = word_mode;
6420       else if (!strcmp (p, "pointer"))
6421         mode = ptr_mode;
6422       else if (!strcmp (p, "libgcc_cmp_return"))
6423         mode = targetm.libgcc_cmp_return_mode ();
6424       else if (!strcmp (p, "libgcc_shift_count"))
6425         mode = targetm.libgcc_shift_count_mode ();
6426       else if (!strcmp (p, "unwind_word"))
6427         mode = targetm.unwind_word_mode ();
6428       else
6429         for (j = 0; j < NUM_MACHINE_MODES; j++)
6430           if (!strcmp (p, GET_MODE_NAME (j)))
6431             {
6432               mode = (enum machine_mode) j;
6433               break;
6434             }
6435
6436       if (mode == VOIDmode)
6437         {
6438           error ("unknown machine mode %qE", ident);
6439           return NULL_TREE;
6440         }
6441
6442       valid_mode = false;
6443       switch (GET_MODE_CLASS (mode))
6444         {
6445         case MODE_INT:
6446         case MODE_PARTIAL_INT:
6447         case MODE_FLOAT:
6448         case MODE_DECIMAL_FLOAT:
6449         case MODE_FRACT:
6450         case MODE_UFRACT:
6451         case MODE_ACCUM:
6452         case MODE_UACCUM:
6453           valid_mode = targetm.scalar_mode_supported_p (mode);
6454           break;
6455
6456         case MODE_COMPLEX_INT:
6457         case MODE_COMPLEX_FLOAT:
6458           valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode));
6459           break;
6460
6461         case MODE_VECTOR_INT:
6462         case MODE_VECTOR_FLOAT:
6463         case MODE_VECTOR_FRACT:
6464         case MODE_VECTOR_UFRACT:
6465         case MODE_VECTOR_ACCUM:
6466         case MODE_VECTOR_UACCUM:
6467           warning (OPT_Wattributes, "specifying vector types with "
6468                    "__attribute__ ((mode)) is deprecated");
6469           warning (OPT_Wattributes,
6470                    "use __attribute__ ((vector_size)) instead");
6471           valid_mode = vector_mode_valid_p (mode);
6472           break;
6473
6474         default:
6475           break;
6476         }
6477       if (!valid_mode)
6478         {
6479           error ("unable to emulate %qs", p);
6480           return NULL_TREE;
6481         }
6482
6483       if (POINTER_TYPE_P (type))
6484         {
6485           addr_space_t as = TYPE_ADDR_SPACE (TREE_TYPE (type));
6486           tree (*fn)(tree, enum machine_mode, bool);
6487
6488           if (!targetm.addr_space.valid_pointer_mode (mode, as))
6489             {
6490               error ("invalid pointer mode %qs", p);
6491               return NULL_TREE;
6492             }
6493
6494           if (TREE_CODE (type) == POINTER_TYPE)
6495             fn = build_pointer_type_for_mode;
6496           else
6497             fn = build_reference_type_for_mode;
6498           typefm = fn (TREE_TYPE (type), mode, false);
6499         }
6500       else
6501         {
6502           /* For fixed-point modes, we need to test if the signness of type
6503              and the machine mode are consistent.  */
6504           if (ALL_FIXED_POINT_MODE_P (mode)
6505               && TYPE_UNSIGNED (type) != UNSIGNED_FIXED_POINT_MODE_P (mode))
6506             {
6507               error ("signness of type and machine mode %qs don't match", p);
6508               return NULL_TREE;
6509             }
6510           /* For fixed-point modes, we need to pass saturating info.  */
6511           typefm = lang_hooks.types.type_for_mode (mode,
6512                         ALL_FIXED_POINT_MODE_P (mode) ? TYPE_SATURATING (type)
6513                                                       : TYPE_UNSIGNED (type));
6514         }
6515
6516       if (typefm == NULL_TREE)
6517         {
6518           error ("no data type for mode %qs", p);
6519           return NULL_TREE;
6520         }
6521       else if (TREE_CODE (type) == ENUMERAL_TYPE)
6522         {
6523           /* For enumeral types, copy the precision from the integer
6524              type returned above.  If not an INTEGER_TYPE, we can't use
6525              this mode for this type.  */
6526           if (TREE_CODE (typefm) != INTEGER_TYPE)
6527             {
6528               error ("cannot use mode %qs for enumeral types", p);
6529               return NULL_TREE;
6530             }
6531
6532           if (flags & ATTR_FLAG_TYPE_IN_PLACE)
6533             {
6534               TYPE_PRECISION (type) = TYPE_PRECISION (typefm);
6535               typefm = type;
6536             }
6537           else
6538             {
6539               /* We cannot build a type variant, as there's code that assumes
6540                  that TYPE_MAIN_VARIANT has the same mode.  This includes the
6541                  debug generators.  Instead, create a subrange type.  This
6542                  results in all of the enumeral values being emitted only once
6543                  in the original, and the subtype gets them by reference.  */
6544               if (TYPE_UNSIGNED (type))
6545                 typefm = make_unsigned_type (TYPE_PRECISION (typefm));
6546               else
6547                 typefm = make_signed_type (TYPE_PRECISION (typefm));
6548               TREE_TYPE (typefm) = type;
6549             }
6550         }
6551       else if (VECTOR_MODE_P (mode)
6552                ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm))
6553                : TREE_CODE (type) != TREE_CODE (typefm))
6554         {
6555           error ("mode %qs applied to inappropriate type", p);
6556           return NULL_TREE;
6557         }
6558
6559       *node = typefm;
6560     }
6561
6562   return NULL_TREE;
6563 }
6564
6565 /* Handle a "section" attribute; arguments as in
6566    struct attribute_spec.handler.  */
6567
6568 static tree
6569 handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6570                           int ARG_UNUSED (flags), bool *no_add_attrs)
6571 {
6572   tree decl = *node;
6573
6574   if (targetm.have_named_sections)
6575     {
6576       user_defined_section_attribute = true;
6577
6578       if ((TREE_CODE (decl) == FUNCTION_DECL
6579            || TREE_CODE (decl) == VAR_DECL)
6580           && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
6581         {
6582           if (TREE_CODE (decl) == VAR_DECL
6583               && current_function_decl != NULL_TREE
6584               && !TREE_STATIC (decl))
6585             {
6586               error_at (DECL_SOURCE_LOCATION (decl),
6587                         "section attribute cannot be specified for "
6588                         "local variables");
6589               *no_add_attrs = true;
6590             }
6591
6592           /* The decl may have already been given a section attribute
6593              from a previous declaration.  Ensure they match.  */
6594           else if (DECL_SECTION_NAME (decl) != NULL_TREE
6595                    && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
6596                               TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
6597             {
6598               error ("section of %q+D conflicts with previous declaration",
6599                      *node);
6600               *no_add_attrs = true;
6601             }
6602           else if (TREE_CODE (decl) == VAR_DECL
6603                    && !targetm.have_tls && targetm.emutls.tmpl_section
6604                    && DECL_THREAD_LOCAL_P (decl))
6605             {
6606               error ("section of %q+D cannot be overridden", *node);
6607               *no_add_attrs = true;
6608             }
6609           else
6610             DECL_SECTION_NAME (decl) = TREE_VALUE (args);
6611         }
6612       else
6613         {
6614           error ("section attribute not allowed for %q+D", *node);
6615           *no_add_attrs = true;
6616         }
6617     }
6618   else
6619     {
6620       error_at (DECL_SOURCE_LOCATION (*node),
6621                 "section attributes are not supported for this target");
6622       *no_add_attrs = true;
6623     }
6624
6625   return NULL_TREE;
6626 }
6627
6628 /* Handle a "aligned" attribute; arguments as in
6629    struct attribute_spec.handler.  */
6630
6631 static tree
6632 handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6633                           int flags, bool *no_add_attrs)
6634 {
6635   tree decl = NULL_TREE;
6636   tree *type = NULL;
6637   int is_type = 0;
6638   tree align_expr = (args ? TREE_VALUE (args)
6639                      : size_int (ATTRIBUTE_ALIGNED_VALUE / BITS_PER_UNIT));
6640   int i;
6641
6642   if (DECL_P (*node))
6643     {
6644       decl = *node;
6645       type = &TREE_TYPE (decl);
6646       is_type = TREE_CODE (*node) == TYPE_DECL;
6647     }
6648   else if (TYPE_P (*node))
6649     type = node, is_type = 1;
6650
6651   if (TREE_CODE (align_expr) != INTEGER_CST)
6652     {
6653       error ("requested alignment is not a constant");
6654       *no_add_attrs = true;
6655     }
6656   else if ((i = tree_log2 (align_expr)) == -1)
6657     {
6658       error ("requested alignment is not a power of 2");
6659       *no_add_attrs = true;
6660     }
6661   else if (i >= HOST_BITS_PER_INT - BITS_PER_UNIT_LOG)
6662     {
6663       error ("requested alignment is too large");
6664       *no_add_attrs = true;
6665     }
6666   else if (is_type)
6667     {
6668       /* If we have a TYPE_DECL, then copy the type, so that we
6669          don't accidentally modify a builtin type.  See pushdecl.  */
6670       if (decl && TREE_TYPE (decl) != error_mark_node
6671           && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
6672         {
6673           tree tt = TREE_TYPE (decl);
6674           *type = build_variant_type_copy (*type);
6675           DECL_ORIGINAL_TYPE (decl) = tt;
6676           TYPE_NAME (*type) = decl;
6677           TREE_USED (*type) = TREE_USED (decl);
6678           TREE_TYPE (decl) = *type;
6679         }
6680       else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6681         *type = build_variant_type_copy (*type);
6682
6683       TYPE_ALIGN (*type) = (1U << i) * BITS_PER_UNIT;
6684       TYPE_USER_ALIGN (*type) = 1;
6685     }
6686   else if (! VAR_OR_FUNCTION_DECL_P (decl)
6687            && TREE_CODE (decl) != FIELD_DECL)
6688     {
6689       error ("alignment may not be specified for %q+D", decl);
6690       *no_add_attrs = true;
6691     }
6692   else if (TREE_CODE (decl) == FUNCTION_DECL
6693            && DECL_ALIGN (decl) > (1U << i) * BITS_PER_UNIT)
6694     {
6695       if (DECL_USER_ALIGN (decl))
6696         error ("alignment for %q+D was previously specified as %d "
6697                "and may not be decreased", decl,
6698                DECL_ALIGN (decl) / BITS_PER_UNIT);
6699       else
6700         error ("alignment for %q+D must be at least %d", decl,
6701                DECL_ALIGN (decl) / BITS_PER_UNIT);
6702       *no_add_attrs = true;
6703     }
6704   else
6705     {
6706       DECL_ALIGN (decl) = (1U << i) * BITS_PER_UNIT;
6707       DECL_USER_ALIGN (decl) = 1;
6708     }
6709
6710   return NULL_TREE;
6711 }
6712
6713 /* Handle a "weak" attribute; arguments as in
6714    struct attribute_spec.handler.  */
6715
6716 static tree
6717 handle_weak_attribute (tree *node, tree name,
6718                        tree ARG_UNUSED (args),
6719                        int ARG_UNUSED (flags),
6720                        bool * ARG_UNUSED (no_add_attrs))
6721 {
6722   if (TREE_CODE (*node) == FUNCTION_DECL
6723       && DECL_DECLARED_INLINE_P (*node))
6724     {
6725       error ("inline function %q+D cannot be declared weak", *node);
6726       *no_add_attrs = true;
6727     }
6728   else if (TREE_CODE (*node) == FUNCTION_DECL
6729            || TREE_CODE (*node) == VAR_DECL)
6730     declare_weak (*node);
6731   else
6732     warning (OPT_Wattributes, "%qE attribute ignored", name);
6733
6734   return NULL_TREE;
6735 }
6736
6737 /* Handle an "alias" attribute; arguments as in
6738    struct attribute_spec.handler.  */
6739
6740 static tree
6741 handle_alias_attribute (tree *node, tree name, tree args,
6742                         int ARG_UNUSED (flags), bool *no_add_attrs)
6743 {
6744   tree decl = *node;
6745
6746   if (TREE_CODE (decl) != FUNCTION_DECL && TREE_CODE (decl) != VAR_DECL)
6747     {
6748       warning (OPT_Wattributes, "%qE attribute ignored", name);
6749       *no_add_attrs = true;
6750     }
6751   else if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
6752       || (TREE_CODE (decl) != FUNCTION_DECL
6753           && TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl))
6754       /* A static variable declaration is always a tentative definition,
6755          but the alias is a non-tentative definition which overrides.  */
6756       || (TREE_CODE (decl) != FUNCTION_DECL
6757           && ! TREE_PUBLIC (decl) && DECL_INITIAL (decl)))
6758     {
6759       error ("%q+D defined both normally and as an alias", decl);
6760       *no_add_attrs = true;
6761     }
6762
6763   /* Note that the very first time we process a nested declaration,
6764      decl_function_context will not be set.  Indeed, *would* never
6765      be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that
6766      we do below.  After such frobbery, pushdecl would set the context.
6767      In any case, this is never what we want.  */
6768   else if (decl_function_context (decl) == 0 && current_function_decl == NULL)
6769     {
6770       tree id;
6771
6772       id = TREE_VALUE (args);
6773       if (TREE_CODE (id) != STRING_CST)
6774         {
6775           error ("alias argument not a string");
6776           *no_add_attrs = true;
6777           return NULL_TREE;
6778         }
6779       id = get_identifier (TREE_STRING_POINTER (id));
6780       /* This counts as a use of the object pointed to.  */
6781       TREE_USED (id) = 1;
6782
6783       if (TREE_CODE (decl) == FUNCTION_DECL)
6784         DECL_INITIAL (decl) = error_mark_node;
6785       else
6786         {
6787           if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
6788             DECL_EXTERNAL (decl) = 1;
6789           else
6790             DECL_EXTERNAL (decl) = 0;
6791           TREE_STATIC (decl) = 1;
6792         }
6793     }
6794   else
6795     {
6796       warning (OPT_Wattributes, "%qE attribute ignored", name);
6797       *no_add_attrs = true;
6798     }
6799
6800   return NULL_TREE;
6801 }
6802
6803 /* Handle a "weakref" attribute; arguments as in struct
6804    attribute_spec.handler.  */
6805
6806 static tree
6807 handle_weakref_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6808                           int flags, bool *no_add_attrs)
6809 {
6810   tree attr = NULL_TREE;
6811
6812   /* We must ignore the attribute when it is associated with
6813      local-scoped decls, since attribute alias is ignored and many
6814      such symbols do not even have a DECL_WEAK field.  */
6815   if (decl_function_context (*node)
6816       || current_function_decl
6817       || (TREE_CODE (*node) != VAR_DECL && TREE_CODE (*node) != FUNCTION_DECL))
6818     {
6819       warning (OPT_Wattributes, "%qE attribute ignored", name);
6820       *no_add_attrs = true;
6821       return NULL_TREE;
6822     }
6823
6824   /* The idea here is that `weakref("name")' mutates into `weakref,
6825      alias("name")', and weakref without arguments, in turn,
6826      implicitly adds weak. */
6827
6828   if (args)
6829     {
6830       attr = tree_cons (get_identifier ("alias"), args, attr);
6831       attr = tree_cons (get_identifier ("weakref"), NULL_TREE, attr);
6832
6833       *no_add_attrs = true;
6834
6835       decl_attributes (node, attr, flags);
6836     }
6837   else
6838     {
6839       if (lookup_attribute ("alias", DECL_ATTRIBUTES (*node)))
6840         error_at (DECL_SOURCE_LOCATION (*node),
6841                   "weakref attribute must appear before alias attribute");
6842
6843       /* Can't call declare_weak because it wants this to be TREE_PUBLIC,
6844          and that isn't supported; and because it wants to add it to
6845          the list of weak decls, which isn't helpful.  */
6846       DECL_WEAK (*node) = 1;
6847     }
6848
6849   return NULL_TREE;
6850 }
6851
6852 /* Handle an "visibility" attribute; arguments as in
6853    struct attribute_spec.handler.  */
6854
6855 static tree
6856 handle_visibility_attribute (tree *node, tree name, tree args,
6857                              int ARG_UNUSED (flags),
6858                              bool *ARG_UNUSED (no_add_attrs))
6859 {
6860   tree decl = *node;
6861   tree id = TREE_VALUE (args);
6862   enum symbol_visibility vis;
6863
6864   if (TYPE_P (*node))
6865     {
6866       if (TREE_CODE (*node) == ENUMERAL_TYPE)
6867         /* OK */;
6868       else if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE)
6869         {
6870           warning (OPT_Wattributes, "%qE attribute ignored on non-class types",
6871                    name);
6872           return NULL_TREE;
6873         }
6874       else if (TYPE_FIELDS (*node))
6875         {
6876           error ("%qE attribute ignored because %qT is already defined",
6877                  name, *node);
6878           return NULL_TREE;
6879         }
6880     }
6881   else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl))
6882     {
6883       warning (OPT_Wattributes, "%qE attribute ignored", name);
6884       return NULL_TREE;
6885     }
6886
6887   if (TREE_CODE (id) != STRING_CST)
6888     {
6889       error ("visibility argument not a string");
6890       return NULL_TREE;
6891     }
6892
6893   /*  If this is a type, set the visibility on the type decl.  */
6894   if (TYPE_P (decl))
6895     {
6896       decl = TYPE_NAME (decl);
6897       if (!decl)
6898         return NULL_TREE;
6899       if (TREE_CODE (decl) == IDENTIFIER_NODE)
6900         {
6901            warning (OPT_Wattributes, "%qE attribute ignored on types",
6902                     name);
6903            return NULL_TREE;
6904         }
6905     }
6906
6907   if (strcmp (TREE_STRING_POINTER (id), "default") == 0)
6908     vis = VISIBILITY_DEFAULT;
6909   else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0)
6910     vis = VISIBILITY_INTERNAL;
6911   else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0)
6912     vis = VISIBILITY_HIDDEN;
6913   else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0)
6914     vis = VISIBILITY_PROTECTED;
6915   else
6916     {
6917       error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\"");
6918       vis = VISIBILITY_DEFAULT;
6919     }
6920
6921   if (DECL_VISIBILITY_SPECIFIED (decl)
6922       && vis != DECL_VISIBILITY (decl))
6923     {
6924       tree attributes = (TYPE_P (*node)
6925                          ? TYPE_ATTRIBUTES (*node)
6926                          : DECL_ATTRIBUTES (decl));
6927       if (lookup_attribute ("visibility", attributes))
6928         error ("%qD redeclared with different visibility", decl);
6929       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
6930                && lookup_attribute ("dllimport", attributes))
6931         error ("%qD was declared %qs which implies default visibility",
6932                decl, "dllimport");
6933       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
6934                && lookup_attribute ("dllexport", attributes))
6935         error ("%qD was declared %qs which implies default visibility",
6936                decl, "dllexport");
6937     }
6938
6939   DECL_VISIBILITY (decl) = vis;
6940   DECL_VISIBILITY_SPECIFIED (decl) = 1;
6941
6942   /* Go ahead and attach the attribute to the node as well.  This is needed
6943      so we can determine whether we have VISIBILITY_DEFAULT because the
6944      visibility was not specified, or because it was explicitly overridden
6945      from the containing scope.  */
6946
6947   return NULL_TREE;
6948 }
6949
6950 /* Determine the ELF symbol visibility for DECL, which is either a
6951    variable or a function.  It is an error to use this function if a
6952    definition of DECL is not available in this translation unit.
6953    Returns true if the final visibility has been determined by this
6954    function; false if the caller is free to make additional
6955    modifications.  */
6956
6957 bool
6958 c_determine_visibility (tree decl)
6959 {
6960   gcc_assert (TREE_CODE (decl) == VAR_DECL
6961               || TREE_CODE (decl) == FUNCTION_DECL);
6962
6963   /* If the user explicitly specified the visibility with an
6964      attribute, honor that.  DECL_VISIBILITY will have been set during
6965      the processing of the attribute.  We check for an explicit
6966      attribute, rather than just checking DECL_VISIBILITY_SPECIFIED,
6967      to distinguish the use of an attribute from the use of a "#pragma
6968      GCC visibility push(...)"; in the latter case we still want other
6969      considerations to be able to overrule the #pragma.  */
6970   if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl))
6971       || (TARGET_DLLIMPORT_DECL_ATTRIBUTES
6972           && (lookup_attribute ("dllimport", DECL_ATTRIBUTES (decl))
6973               || lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))))
6974     return true;
6975
6976   /* Set default visibility to whatever the user supplied with
6977      visibility_specified depending on #pragma GCC visibility.  */
6978   if (!DECL_VISIBILITY_SPECIFIED (decl))
6979     {
6980       if (visibility_options.inpragma
6981           || DECL_VISIBILITY (decl) != default_visibility)
6982         {
6983           DECL_VISIBILITY (decl) = default_visibility;
6984           DECL_VISIBILITY_SPECIFIED (decl) = visibility_options.inpragma;
6985           /* If visibility changed and DECL already has DECL_RTL, ensure
6986              symbol flags are updated.  */
6987           if (((TREE_CODE (decl) == VAR_DECL && TREE_STATIC (decl))
6988                || TREE_CODE (decl) == FUNCTION_DECL)
6989               && DECL_RTL_SET_P (decl))
6990             make_decl_rtl (decl);
6991         }
6992     }
6993   return false;
6994 }
6995
6996 /* Handle an "tls_model" attribute; arguments as in
6997    struct attribute_spec.handler.  */
6998
6999 static tree
7000 handle_tls_model_attribute (tree *node, tree name, tree args,
7001                             int ARG_UNUSED (flags), bool *no_add_attrs)
7002 {
7003   tree id;
7004   tree decl = *node;
7005   enum tls_model kind;
7006
7007   *no_add_attrs = true;
7008
7009   if (TREE_CODE (decl) != VAR_DECL || !DECL_THREAD_LOCAL_P (decl))
7010     {
7011       warning (OPT_Wattributes, "%qE attribute ignored", name);
7012       return NULL_TREE;
7013     }
7014
7015   kind = DECL_TLS_MODEL (decl);
7016   id = TREE_VALUE (args);
7017   if (TREE_CODE (id) != STRING_CST)
7018     {
7019       error ("tls_model argument not a string");
7020       return NULL_TREE;
7021     }
7022
7023   if (!strcmp (TREE_STRING_POINTER (id), "local-exec"))
7024     kind = TLS_MODEL_LOCAL_EXEC;
7025   else if (!strcmp (TREE_STRING_POINTER (id), "initial-exec"))
7026     kind = TLS_MODEL_INITIAL_EXEC;
7027   else if (!strcmp (TREE_STRING_POINTER (id), "local-dynamic"))
7028     kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
7029   else if (!strcmp (TREE_STRING_POINTER (id), "global-dynamic"))
7030     kind = TLS_MODEL_GLOBAL_DYNAMIC;
7031   else
7032     error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\"");
7033
7034   DECL_TLS_MODEL (decl) = kind;
7035   return NULL_TREE;
7036 }
7037
7038 /* Handle a "no_instrument_function" attribute; arguments as in
7039    struct attribute_spec.handler.  */
7040
7041 static tree
7042 handle_no_instrument_function_attribute (tree *node, tree name,
7043                                          tree ARG_UNUSED (args),
7044                                          int ARG_UNUSED (flags),
7045                                          bool *no_add_attrs)
7046 {
7047   tree decl = *node;
7048
7049   if (TREE_CODE (decl) != FUNCTION_DECL)
7050     {
7051       error_at (DECL_SOURCE_LOCATION (decl),
7052                 "%qE attribute applies only to functions", name);
7053       *no_add_attrs = true;
7054     }
7055   else if (DECL_INITIAL (decl))
7056     {
7057       error_at (DECL_SOURCE_LOCATION (decl),
7058                 "can%'t set %qE attribute after definition", name);
7059       *no_add_attrs = true;
7060     }
7061   else
7062     DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
7063
7064   return NULL_TREE;
7065 }
7066
7067 /* Handle a "malloc" attribute; arguments as in
7068    struct attribute_spec.handler.  */
7069
7070 static tree
7071 handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7072                          int ARG_UNUSED (flags), bool *no_add_attrs)
7073 {
7074   if (TREE_CODE (*node) == FUNCTION_DECL
7075       && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node))))
7076     DECL_IS_MALLOC (*node) = 1;
7077   else
7078     {
7079       warning (OPT_Wattributes, "%qE attribute ignored", name);
7080       *no_add_attrs = true;
7081     }
7082
7083   return NULL_TREE;
7084 }
7085
7086 /* Handle a "alloc_size" attribute; arguments as in
7087    struct attribute_spec.handler.  */
7088
7089 static tree
7090 handle_alloc_size_attribute (tree *node, tree ARG_UNUSED (name), tree args,
7091                              int ARG_UNUSED (flags), bool *no_add_attrs)
7092 {
7093   unsigned arg_count = type_num_arguments (*node);
7094   for (; args; args = TREE_CHAIN (args))
7095     {
7096       tree position = TREE_VALUE (args);
7097
7098       if (TREE_CODE (position) != INTEGER_CST
7099           || TREE_INT_CST_HIGH (position)
7100           || TREE_INT_CST_LOW (position) < 1
7101           || TREE_INT_CST_LOW (position) > arg_count )
7102         {
7103           warning (OPT_Wattributes,
7104                    "alloc_size parameter outside range");
7105           *no_add_attrs = true;
7106           return NULL_TREE;
7107         }
7108     }
7109   return NULL_TREE;
7110 }
7111
7112 /* Handle a "returns_twice" attribute; arguments as in
7113    struct attribute_spec.handler.  */
7114
7115 static tree
7116 handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7117                          int ARG_UNUSED (flags), bool *no_add_attrs)
7118 {
7119   if (TREE_CODE (*node) == FUNCTION_DECL)
7120     DECL_IS_RETURNS_TWICE (*node) = 1;
7121   else
7122     {
7123       warning (OPT_Wattributes, "%qE attribute ignored", name);
7124       *no_add_attrs = true;
7125     }
7126
7127   return NULL_TREE;
7128 }
7129
7130 /* Handle a "no_limit_stack" attribute; arguments as in
7131    struct attribute_spec.handler.  */
7132
7133 static tree
7134 handle_no_limit_stack_attribute (tree *node, tree name,
7135                                  tree ARG_UNUSED (args),
7136                                  int ARG_UNUSED (flags),
7137                                  bool *no_add_attrs)
7138 {
7139   tree decl = *node;
7140
7141   if (TREE_CODE (decl) != FUNCTION_DECL)
7142     {
7143       error_at (DECL_SOURCE_LOCATION (decl),
7144              "%qE attribute applies only to functions", name);
7145       *no_add_attrs = true;
7146     }
7147   else if (DECL_INITIAL (decl))
7148     {
7149       error_at (DECL_SOURCE_LOCATION (decl),
7150                 "can%'t set %qE attribute after definition", name);
7151       *no_add_attrs = true;
7152     }
7153   else
7154     DECL_NO_LIMIT_STACK (decl) = 1;
7155
7156   return NULL_TREE;
7157 }
7158
7159 /* Handle a "pure" attribute; arguments as in
7160    struct attribute_spec.handler.  */
7161
7162 static tree
7163 handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7164                        int ARG_UNUSED (flags), bool *no_add_attrs)
7165 {
7166   if (TREE_CODE (*node) == FUNCTION_DECL)
7167     DECL_PURE_P (*node) = 1;
7168   /* ??? TODO: Support types.  */
7169   else
7170     {
7171       warning (OPT_Wattributes, "%qE attribute ignored", name);
7172       *no_add_attrs = true;
7173     }
7174
7175   return NULL_TREE;
7176 }
7177
7178 /* Handle a "no vops" attribute; arguments as in
7179    struct attribute_spec.handler.  */
7180
7181 static tree
7182 handle_novops_attribute (tree *node, tree ARG_UNUSED (name),
7183                          tree ARG_UNUSED (args), int ARG_UNUSED (flags),
7184                          bool *ARG_UNUSED (no_add_attrs))
7185 {
7186   gcc_assert (TREE_CODE (*node) == FUNCTION_DECL);
7187   DECL_IS_NOVOPS (*node) = 1;
7188   return NULL_TREE;
7189 }
7190
7191 /* Handle a "deprecated" attribute; arguments as in
7192    struct attribute_spec.handler.  */
7193
7194 static tree
7195 handle_deprecated_attribute (tree *node, tree name,
7196                              tree args, int flags,
7197                              bool *no_add_attrs)
7198 {
7199   tree type = NULL_TREE;
7200   int warn = 0;
7201   tree what = NULL_TREE;
7202
7203   if (!args)
7204     *no_add_attrs = true;
7205   else if (TREE_CODE (TREE_VALUE (args)) != STRING_CST)
7206     {
7207       error ("deprecated message is not a string");
7208       *no_add_attrs = true;
7209     }
7210
7211   if (DECL_P (*node))
7212     {
7213       tree decl = *node;
7214       type = TREE_TYPE (decl);
7215
7216       if (TREE_CODE (decl) == TYPE_DECL
7217           || TREE_CODE (decl) == PARM_DECL
7218           || TREE_CODE (decl) == VAR_DECL
7219           || TREE_CODE (decl) == FUNCTION_DECL
7220           || TREE_CODE (decl) == FIELD_DECL)
7221         TREE_DEPRECATED (decl) = 1;
7222       else
7223         warn = 1;
7224     }
7225   else if (TYPE_P (*node))
7226     {
7227       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
7228         *node = build_variant_type_copy (*node);
7229       TREE_DEPRECATED (*node) = 1;
7230       type = *node;
7231     }
7232   else
7233     warn = 1;
7234
7235   if (warn)
7236     {
7237       *no_add_attrs = true;
7238       if (type && TYPE_NAME (type))
7239         {
7240           if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
7241             what = TYPE_NAME (*node);
7242           else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
7243                    && DECL_NAME (TYPE_NAME (type)))
7244             what = DECL_NAME (TYPE_NAME (type));
7245         }
7246       if (what)
7247         warning (OPT_Wattributes, "%qE attribute ignored for %qE", name, what);
7248       else
7249         warning (OPT_Wattributes, "%qE attribute ignored", name);
7250     }
7251
7252   return NULL_TREE;
7253 }
7254
7255 /* Handle a "vector_size" attribute; arguments as in
7256    struct attribute_spec.handler.  */
7257
7258 static tree
7259 handle_vector_size_attribute (tree *node, tree name, tree args,
7260                               int ARG_UNUSED (flags),
7261                               bool *no_add_attrs)
7262 {
7263   unsigned HOST_WIDE_INT vecsize, nunits;
7264   enum machine_mode orig_mode;
7265   tree type = *node, new_type, size;
7266
7267   *no_add_attrs = true;
7268
7269   size = TREE_VALUE (args);
7270
7271   if (!host_integerp (size, 1))
7272     {
7273       warning (OPT_Wattributes, "%qE attribute ignored", name);
7274       return NULL_TREE;
7275     }
7276
7277   /* Get the vector size (in bytes).  */
7278   vecsize = tree_low_cst (size, 1);
7279
7280   /* We need to provide for vector pointers, vector arrays, and
7281      functions returning vectors.  For example:
7282
7283        __attribute__((vector_size(16))) short *foo;
7284
7285      In this case, the mode is SI, but the type being modified is
7286      HI, so we need to look further.  */
7287
7288   while (POINTER_TYPE_P (type)
7289          || TREE_CODE (type) == FUNCTION_TYPE
7290          || TREE_CODE (type) == METHOD_TYPE
7291          || TREE_CODE (type) == ARRAY_TYPE
7292          || TREE_CODE (type) == OFFSET_TYPE)
7293     type = TREE_TYPE (type);
7294
7295   /* Get the mode of the type being modified.  */
7296   orig_mode = TYPE_MODE (type);
7297
7298   if ((!INTEGRAL_TYPE_P (type)
7299        && !SCALAR_FLOAT_TYPE_P (type)
7300        && !FIXED_POINT_TYPE_P (type))
7301       || (!SCALAR_FLOAT_MODE_P (orig_mode)
7302           && GET_MODE_CLASS (orig_mode) != MODE_INT
7303           && !ALL_SCALAR_FIXED_POINT_MODE_P (orig_mode))
7304       || !host_integerp (TYPE_SIZE_UNIT (type), 1)
7305       || TREE_CODE (type) == BOOLEAN_TYPE)
7306     {
7307       error ("invalid vector type for attribute %qE", name);
7308       return NULL_TREE;
7309     }
7310
7311   if (vecsize % tree_low_cst (TYPE_SIZE_UNIT (type), 1))
7312     {
7313       error ("vector size not an integral multiple of component size");
7314       return NULL;
7315     }
7316
7317   if (vecsize == 0)
7318     {
7319       error ("zero vector size");
7320       return NULL;
7321     }
7322
7323   /* Calculate how many units fit in the vector.  */
7324   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
7325   if (nunits & (nunits - 1))
7326     {
7327       error ("number of components of the vector not a power of two");
7328       return NULL_TREE;
7329     }
7330
7331   new_type = build_vector_type (type, nunits);
7332
7333   /* Build back pointers if needed.  */
7334   *node = lang_hooks.types.reconstruct_complex_type (*node, new_type);
7335
7336   return NULL_TREE;
7337 }
7338
7339 /* Handle the "nonnull" attribute.  */
7340 static tree
7341 handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
7342                           tree args, int ARG_UNUSED (flags),
7343                           bool *no_add_attrs)
7344 {
7345   tree type = *node;
7346   unsigned HOST_WIDE_INT attr_arg_num;
7347
7348   /* If no arguments are specified, all pointer arguments should be
7349      non-null.  Verify a full prototype is given so that the arguments
7350      will have the correct types when we actually check them later.  */
7351   if (!args)
7352     {
7353       if (!TYPE_ARG_TYPES (type))
7354         {
7355           error ("nonnull attribute without arguments on a non-prototype");
7356           *no_add_attrs = true;
7357         }
7358       return NULL_TREE;
7359     }
7360
7361   /* Argument list specified.  Verify that each argument number references
7362      a pointer argument.  */
7363   for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
7364     {
7365       tree argument;
7366       unsigned HOST_WIDE_INT arg_num = 0, ck_num;
7367
7368       if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
7369         {
7370           error ("nonnull argument has invalid operand number (argument %lu)",
7371                  (unsigned long) attr_arg_num);
7372           *no_add_attrs = true;
7373           return NULL_TREE;
7374         }
7375
7376       argument = TYPE_ARG_TYPES (type);
7377       if (argument)
7378         {
7379           for (ck_num = 1; ; ck_num++)
7380             {
7381               if (!argument || ck_num == arg_num)
7382                 break;
7383               argument = TREE_CHAIN (argument);
7384             }
7385
7386           if (!argument
7387               || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
7388             {
7389               error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)",
7390                      (unsigned long) attr_arg_num, (unsigned long) arg_num);
7391               *no_add_attrs = true;
7392               return NULL_TREE;
7393             }
7394
7395           if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
7396             {
7397               error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)",
7398                    (unsigned long) attr_arg_num, (unsigned long) arg_num);
7399               *no_add_attrs = true;
7400               return NULL_TREE;
7401             }
7402         }
7403     }
7404
7405   return NULL_TREE;
7406 }
7407
7408 /* Check the argument list of a function call for null in argument slots
7409    that are marked as requiring a non-null pointer argument.  The NARGS
7410    arguments are passed in the array ARGARRAY.
7411 */
7412
7413 static void
7414 check_function_nonnull (tree attrs, int nargs, tree *argarray)
7415 {
7416   tree a, args;
7417   int i;
7418
7419   for (a = attrs; a; a = TREE_CHAIN (a))
7420     {
7421       if (is_attribute_p ("nonnull", TREE_PURPOSE (a)))
7422         {
7423           args = TREE_VALUE (a);
7424
7425           /* Walk the argument list.  If we encounter an argument number we
7426              should check for non-null, do it.  If the attribute has no args,
7427              then every pointer argument is checked (in which case the check
7428              for pointer type is done in check_nonnull_arg).  */
7429           for (i = 0; i < nargs; i++)
7430             {
7431               if (!args || nonnull_check_p (args, i + 1))
7432                 check_function_arguments_recurse (check_nonnull_arg, NULL,
7433                                                   argarray[i],
7434                                                   i + 1);
7435             }
7436         }
7437     }
7438 }
7439
7440 /* Check that the Nth argument of a function call (counting backwards
7441    from the end) is a (pointer)0.  The NARGS arguments are passed in the
7442    array ARGARRAY.  */
7443
7444 static void
7445 check_function_sentinel (tree attrs, int nargs, tree *argarray, tree typelist)
7446 {
7447   tree attr = lookup_attribute ("sentinel", attrs);
7448
7449   if (attr)
7450     {
7451       int len = 0;
7452       int pos = 0;
7453       tree sentinel;
7454
7455       /* Skip over the named arguments.  */
7456       while (typelist && len < nargs)
7457         {
7458           typelist = TREE_CHAIN (typelist);
7459           len++;
7460         }
7461
7462       if (TREE_VALUE (attr))
7463         {
7464           tree p = TREE_VALUE (TREE_VALUE (attr));
7465           pos = TREE_INT_CST_LOW (p);
7466         }
7467
7468       /* The sentinel must be one of the varargs, i.e.
7469          in position >= the number of fixed arguments.  */
7470       if ((nargs - 1 - pos) < len)
7471         {
7472           warning (OPT_Wformat,
7473                    "not enough variable arguments to fit a sentinel");
7474           return;
7475         }
7476
7477       /* Validate the sentinel.  */
7478       sentinel = argarray[nargs - 1 - pos];
7479       if ((!POINTER_TYPE_P (TREE_TYPE (sentinel))
7480            || !integer_zerop (sentinel))
7481           /* Although __null (in C++) is only an integer we allow it
7482              nevertheless, as we are guaranteed that it's exactly
7483              as wide as a pointer, and we don't want to force
7484              users to cast the NULL they have written there.
7485              We warn with -Wstrict-null-sentinel, though.  */
7486           && (warn_strict_null_sentinel || null_node != sentinel))
7487         warning (OPT_Wformat, "missing sentinel in function call");
7488     }
7489 }
7490
7491 /* Helper for check_function_nonnull; given a list of operands which
7492    must be non-null in ARGS, determine if operand PARAM_NUM should be
7493    checked.  */
7494
7495 static bool
7496 nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num)
7497 {
7498   unsigned HOST_WIDE_INT arg_num = 0;
7499
7500   for (; args; args = TREE_CHAIN (args))
7501     {
7502       bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num);
7503
7504       gcc_assert (found);
7505
7506       if (arg_num == param_num)
7507         return true;
7508     }
7509   return false;
7510 }
7511
7512 /* Check that the function argument PARAM (which is operand number
7513    PARAM_NUM) is non-null.  This is called by check_function_nonnull
7514    via check_function_arguments_recurse.  */
7515
7516 static void
7517 check_nonnull_arg (void * ARG_UNUSED (ctx), tree param,
7518                    unsigned HOST_WIDE_INT param_num)
7519 {
7520   /* Just skip checking the argument if it's not a pointer.  This can
7521      happen if the "nonnull" attribute was given without an operand
7522      list (which means to check every pointer argument).  */
7523
7524   if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE)
7525     return;
7526
7527   if (integer_zerop (param))
7528     warning (OPT_Wnonnull, "null argument where non-null required "
7529              "(argument %lu)", (unsigned long) param_num);
7530 }
7531
7532 /* Helper for nonnull attribute handling; fetch the operand number
7533    from the attribute argument list.  */
7534
7535 static bool
7536 get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp)
7537 {
7538   /* Verify the arg number is a constant.  */
7539   if (TREE_CODE (arg_num_expr) != INTEGER_CST
7540       || TREE_INT_CST_HIGH (arg_num_expr) != 0)
7541     return false;
7542
7543   *valp = TREE_INT_CST_LOW (arg_num_expr);
7544   return true;
7545 }
7546
7547 /* Handle a "nothrow" attribute; arguments as in
7548    struct attribute_spec.handler.  */
7549
7550 static tree
7551 handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7552                           int ARG_UNUSED (flags), bool *no_add_attrs)
7553 {
7554   if (TREE_CODE (*node) == FUNCTION_DECL)
7555     TREE_NOTHROW (*node) = 1;
7556   /* ??? TODO: Support types.  */
7557   else
7558     {
7559       warning (OPT_Wattributes, "%qE attribute ignored", name);
7560       *no_add_attrs = true;
7561     }
7562
7563   return NULL_TREE;
7564 }
7565
7566 /* Handle a "cleanup" attribute; arguments as in
7567    struct attribute_spec.handler.  */
7568
7569 static tree
7570 handle_cleanup_attribute (tree *node, tree name, tree args,
7571                           int ARG_UNUSED (flags), bool *no_add_attrs)
7572 {
7573   tree decl = *node;
7574   tree cleanup_id, cleanup_decl;
7575
7576   /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do
7577      for global destructors in C++.  This requires infrastructure that
7578      we don't have generically at the moment.  It's also not a feature
7579      we'd be missing too much, since we do have attribute constructor.  */
7580   if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl))
7581     {
7582       warning (OPT_Wattributes, "%qE attribute ignored", name);
7583       *no_add_attrs = true;
7584       return NULL_TREE;
7585     }
7586
7587   /* Verify that the argument is a function in scope.  */
7588   /* ??? We could support pointers to functions here as well, if
7589      that was considered desirable.  */
7590   cleanup_id = TREE_VALUE (args);
7591   if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE)
7592     {
7593       error ("cleanup argument not an identifier");
7594       *no_add_attrs = true;
7595       return NULL_TREE;
7596     }
7597   cleanup_decl = lookup_name (cleanup_id);
7598   if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL)
7599     {
7600       error ("cleanup argument not a function");
7601       *no_add_attrs = true;
7602       return NULL_TREE;
7603     }
7604
7605   /* That the function has proper type is checked with the
7606      eventual call to build_function_call.  */
7607
7608   return NULL_TREE;
7609 }
7610
7611 /* Handle a "warn_unused_result" attribute.  No special handling.  */
7612
7613 static tree
7614 handle_warn_unused_result_attribute (tree *node, tree name,
7615                                tree ARG_UNUSED (args),
7616                                int ARG_UNUSED (flags), bool *no_add_attrs)
7617 {
7618   /* Ignore the attribute for functions not returning any value.  */
7619   if (VOID_TYPE_P (TREE_TYPE (*node)))
7620     {
7621       warning (OPT_Wattributes, "%qE attribute ignored", name);
7622       *no_add_attrs = true;
7623     }
7624
7625   return NULL_TREE;
7626 }
7627
7628 /* Handle a "sentinel" attribute.  */
7629
7630 static tree
7631 handle_sentinel_attribute (tree *node, tree name, tree args,
7632                            int ARG_UNUSED (flags), bool *no_add_attrs)
7633 {
7634   tree params = TYPE_ARG_TYPES (*node);
7635
7636   if (!params)
7637     {
7638       warning (OPT_Wattributes,
7639                "%qE attribute requires prototypes with named arguments", name);
7640       *no_add_attrs = true;
7641     }
7642   else
7643     {
7644       while (TREE_CHAIN (params))
7645         params = TREE_CHAIN (params);
7646
7647       if (VOID_TYPE_P (TREE_VALUE (params)))
7648         {
7649           warning (OPT_Wattributes,
7650                    "%qE attribute only applies to variadic functions", name);
7651           *no_add_attrs = true;
7652         }
7653     }
7654
7655   if (args)
7656     {
7657       tree position = TREE_VALUE (args);
7658
7659       if (TREE_CODE (position) != INTEGER_CST)
7660         {
7661           warning (OPT_Wattributes,
7662                    "requested position is not an integer constant");
7663           *no_add_attrs = true;
7664         }
7665       else
7666         {
7667           if (tree_int_cst_lt (position, integer_zero_node))
7668             {
7669               warning (OPT_Wattributes,
7670                        "requested position is less than zero");
7671               *no_add_attrs = true;
7672             }
7673         }
7674     }
7675
7676   return NULL_TREE;
7677 }
7678
7679 /* Handle a "type_generic" attribute.  */
7680
7681 static tree
7682 handle_type_generic_attribute (tree *node, tree ARG_UNUSED (name),
7683                                tree ARG_UNUSED (args), int ARG_UNUSED (flags),
7684                                bool * ARG_UNUSED (no_add_attrs))
7685 {
7686   tree params;
7687
7688   /* Ensure we have a function type.  */
7689   gcc_assert (TREE_CODE (*node) == FUNCTION_TYPE);
7690
7691   params = TYPE_ARG_TYPES (*node);
7692   while (params && ! VOID_TYPE_P (TREE_VALUE (params)))
7693     params = TREE_CHAIN (params);
7694
7695   /* Ensure we have a variadic function.  */
7696   gcc_assert (!params);
7697
7698   return NULL_TREE;
7699 }
7700
7701 /* Handle a "target" attribute.  */
7702
7703 static tree
7704 handle_target_attribute (tree *node, tree name, tree args, int flags,
7705                          bool *no_add_attrs)
7706 {
7707   /* Ensure we have a function type.  */
7708   if (TREE_CODE (*node) != FUNCTION_DECL)
7709     {
7710       warning (OPT_Wattributes, "%qE attribute ignored", name);
7711       *no_add_attrs = true;
7712     }
7713   else if (! targetm.target_option.valid_attribute_p (*node, name, args,
7714                                                       flags))
7715     *no_add_attrs = true;
7716
7717   return NULL_TREE;
7718 }
7719
7720 /* Arguments being collected for optimization.  */
7721 typedef const char *const_char_p;               /* For DEF_VEC_P.  */
7722 DEF_VEC_P(const_char_p);
7723 DEF_VEC_ALLOC_P(const_char_p, gc);
7724 static GTY(()) VEC(const_char_p, gc) *optimize_args;
7725
7726
7727 /* Inner function to convert a TREE_LIST to argv string to parse the optimize
7728    options in ARGS.  ATTR_P is true if this is for attribute(optimize), and
7729    false for #pragma GCC optimize.  */
7730
7731 bool
7732 parse_optimize_options (tree args, bool attr_p)
7733 {
7734   bool ret = true;
7735   unsigned opt_argc;
7736   unsigned i;
7737   int saved_flag_strict_aliasing;
7738   const char **opt_argv;
7739   tree ap;
7740
7741   /* Build up argv vector.  Just in case the string is stored away, use garbage
7742      collected strings.  */
7743   VEC_truncate (const_char_p, optimize_args, 0);
7744   VEC_safe_push (const_char_p, gc, optimize_args, NULL);
7745
7746   for (ap = args; ap != NULL_TREE; ap = TREE_CHAIN (ap))
7747     {
7748       tree value = TREE_VALUE (ap);
7749
7750       if (TREE_CODE (value) == INTEGER_CST)
7751         {
7752           char buffer[20];
7753           sprintf (buffer, "-O%ld", (long) TREE_INT_CST_LOW (value));
7754           VEC_safe_push (const_char_p, gc, optimize_args, ggc_strdup (buffer));
7755         }
7756
7757       else if (TREE_CODE (value) == STRING_CST)
7758         {
7759           /* Split string into multiple substrings.  */
7760           size_t len = TREE_STRING_LENGTH (value);
7761           char *p = ASTRDUP (TREE_STRING_POINTER (value));
7762           char *end = p + len;
7763           char *comma;
7764           char *next_p = p;
7765
7766           while (next_p != NULL)
7767             {
7768               size_t len2;
7769               char *q, *r;
7770
7771               p = next_p;
7772               comma = strchr (p, ',');
7773               if (comma)
7774                 {
7775                   len2 = comma - p;
7776                   *comma = '\0';
7777                   next_p = comma+1;
7778                 }
7779               else
7780                 {
7781                   len2 = end - p;
7782                   next_p = NULL;
7783                 }
7784
7785               r = q = (char *) ggc_alloc (len2 + 3);
7786
7787               /* If the user supplied -Oxxx or -fxxx, only allow -Oxxx or -fxxx
7788                  options.  */
7789               if (*p == '-' && p[1] != 'O' && p[1] != 'f')
7790                 {
7791                   ret = false;
7792                   if (attr_p)
7793                     warning (OPT_Wattributes,
7794                              "Bad option %s to optimize attribute.", p);
7795                   else
7796                     warning (OPT_Wpragmas,
7797                              "Bad option %s to pragma attribute", p);
7798                   continue;
7799                 }
7800
7801               if (*p != '-')
7802                 {
7803                   *r++ = '-';
7804
7805                   /* Assume that Ox is -Ox, a numeric value is -Ox, a s by
7806                      itself is -Os, and any other switch begins with a -f.  */
7807                   if ((*p >= '0' && *p <= '9')
7808                       || (p[0] == 's' && p[1] == '\0'))
7809                     *r++ = 'O';
7810                   else if (*p != 'O')
7811                     *r++ = 'f';
7812                 }
7813
7814               memcpy (r, p, len2);
7815               r[len2] = '\0';
7816               VEC_safe_push (const_char_p, gc, optimize_args, q);
7817             }
7818
7819         }
7820     }
7821
7822   opt_argc = VEC_length (const_char_p, optimize_args);
7823   opt_argv = (const char **) alloca (sizeof (char *) * (opt_argc + 1));
7824
7825   for (i = 1; i < opt_argc; i++)
7826     opt_argv[i] = VEC_index (const_char_p, optimize_args, i);
7827
7828   saved_flag_strict_aliasing = flag_strict_aliasing;
7829
7830   /* Now parse the options.  */
7831   decode_options (opt_argc, opt_argv);
7832
7833   targetm.override_options_after_change();
7834
7835   /* Don't allow changing -fstrict-aliasing.  */
7836   flag_strict_aliasing = saved_flag_strict_aliasing;
7837
7838   VEC_truncate (const_char_p, optimize_args, 0);
7839   return ret;
7840 }
7841
7842 /* For handling "optimize" attribute. arguments as in
7843    struct attribute_spec.handler.  */
7844
7845 static tree
7846 handle_optimize_attribute (tree *node, tree name, tree args,
7847                            int ARG_UNUSED (flags), bool *no_add_attrs)
7848 {
7849   /* Ensure we have a function type.  */
7850   if (TREE_CODE (*node) != FUNCTION_DECL)
7851     {
7852       warning (OPT_Wattributes, "%qE attribute ignored", name);
7853       *no_add_attrs = true;
7854     }
7855   else
7856     {
7857       struct cl_optimization cur_opts;
7858       tree old_opts = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node);
7859
7860       /* Save current options.  */
7861       cl_optimization_save (&cur_opts);
7862
7863       /* If we previously had some optimization options, use them as the
7864          default.  */
7865       if (old_opts)
7866         cl_optimization_restore (TREE_OPTIMIZATION (old_opts));
7867
7868       /* Parse options, and update the vector.  */
7869       parse_optimize_options (args, true);
7870       DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node)
7871         = build_optimization_node ();
7872
7873       /* Restore current options.  */
7874       cl_optimization_restore (&cur_opts);
7875     }
7876
7877   return NULL_TREE;
7878 }
7879 \f
7880 /* Check for valid arguments being passed to a function.
7881    ATTRS is a list of attributes.  There are NARGS arguments in the array
7882    ARGARRAY.  TYPELIST is the list of argument types for the function.
7883  */
7884 void
7885 check_function_arguments (tree attrs, int nargs, tree *argarray, tree typelist)
7886 {
7887   /* Check for null being passed in a pointer argument that must be
7888      non-null.  We also need to do this if format checking is enabled.  */
7889
7890   if (warn_nonnull)
7891     check_function_nonnull (attrs, nargs, argarray);
7892
7893   /* Check for errors in format strings.  */
7894
7895   if (warn_format || warn_missing_format_attribute)
7896     check_function_format (attrs, nargs, argarray);
7897
7898   if (warn_format)
7899     check_function_sentinel (attrs, nargs, argarray, typelist);
7900 }
7901
7902 /* Generic argument checking recursion routine.  PARAM is the argument to
7903    be checked.  PARAM_NUM is the number of the argument.  CALLBACK is invoked
7904    once the argument is resolved.  CTX is context for the callback.  */
7905 void
7906 check_function_arguments_recurse (void (*callback)
7907                                   (void *, tree, unsigned HOST_WIDE_INT),
7908                                   void *ctx, tree param,
7909                                   unsigned HOST_WIDE_INT param_num)
7910 {
7911   if (CONVERT_EXPR_P (param)
7912       && (TYPE_PRECISION (TREE_TYPE (param))
7913           == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (param, 0)))))
7914     {
7915       /* Strip coercion.  */
7916       check_function_arguments_recurse (callback, ctx,
7917                                         TREE_OPERAND (param, 0), param_num);
7918       return;
7919     }
7920
7921   if (TREE_CODE (param) == CALL_EXPR)
7922     {
7923       tree type = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (param)));
7924       tree attrs;
7925       bool found_format_arg = false;
7926
7927       /* See if this is a call to a known internationalization function
7928          that modifies a format arg.  Such a function may have multiple
7929          format_arg attributes (for example, ngettext).  */
7930
7931       for (attrs = TYPE_ATTRIBUTES (type);
7932            attrs;
7933            attrs = TREE_CHAIN (attrs))
7934         if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs)))
7935           {
7936             tree inner_arg;
7937             tree format_num_expr;
7938             int format_num;
7939             int i;
7940             call_expr_arg_iterator iter;
7941
7942             /* Extract the argument number, which was previously checked
7943                to be valid.  */
7944             format_num_expr = TREE_VALUE (TREE_VALUE (attrs));
7945
7946             gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST
7947                         && !TREE_INT_CST_HIGH (format_num_expr));
7948
7949             format_num = TREE_INT_CST_LOW (format_num_expr);
7950
7951             for (inner_arg = first_call_expr_arg (param, &iter), i = 1;
7952                  inner_arg != 0;
7953                  inner_arg = next_call_expr_arg (&iter), i++)
7954               if (i == format_num)
7955                 {
7956                   check_function_arguments_recurse (callback, ctx,
7957                                                     inner_arg, param_num);
7958                   found_format_arg = true;
7959                   break;
7960                 }
7961           }
7962
7963       /* If we found a format_arg attribute and did a recursive check,
7964          we are done with checking this argument.  Otherwise, we continue
7965          and this will be considered a non-literal.  */
7966       if (found_format_arg)
7967         return;
7968     }
7969
7970   if (TREE_CODE (param) == COND_EXPR)
7971     {
7972       /* Check both halves of the conditional expression.  */
7973       check_function_arguments_recurse (callback, ctx,
7974                                         TREE_OPERAND (param, 1), param_num);
7975       check_function_arguments_recurse (callback, ctx,
7976                                         TREE_OPERAND (param, 2), param_num);
7977       return;
7978     }
7979
7980   (*callback) (ctx, param, param_num);
7981 }
7982
7983 /* Checks for a builtin function FNDECL that the number of arguments
7984    NARGS against the required number REQUIRED and issues an error if
7985    there is a mismatch.  Returns true if the number of arguments is
7986    correct, otherwise false.  */
7987
7988 static bool
7989 builtin_function_validate_nargs (tree fndecl, int nargs, int required)
7990 {
7991   if (nargs < required)
7992     {
7993       error_at (input_location,
7994                 "not enough arguments to function %qE", fndecl);
7995       return false;
7996     }
7997   else if (nargs > required)
7998     {
7999       error_at (input_location,
8000                 "too many arguments to function %qE", fndecl);
8001       return false;
8002     }
8003   return true;
8004 }
8005
8006 /* Verifies the NARGS arguments ARGS to the builtin function FNDECL.
8007    Returns false if there was an error, otherwise true.  */
8008
8009 bool
8010 check_builtin_function_arguments (tree fndecl, int nargs, tree *args)
8011 {
8012   if (!DECL_BUILT_IN (fndecl)
8013       || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL)
8014     return true;
8015
8016   switch (DECL_FUNCTION_CODE (fndecl))
8017     {
8018     case BUILT_IN_CONSTANT_P:
8019       return builtin_function_validate_nargs (fndecl, nargs, 1);
8020
8021     case BUILT_IN_ISFINITE:
8022     case BUILT_IN_ISINF:
8023     case BUILT_IN_ISINF_SIGN:
8024     case BUILT_IN_ISNAN:
8025     case BUILT_IN_ISNORMAL:
8026       if (builtin_function_validate_nargs (fndecl, nargs, 1))
8027         {
8028           if (TREE_CODE (TREE_TYPE (args[0])) != REAL_TYPE)
8029             {
8030               error ("non-floating-point argument in call to "
8031                      "function %qE", fndecl);
8032               return false;
8033             }
8034           return true;
8035         }
8036       return false;
8037
8038     case BUILT_IN_ISGREATER:
8039     case BUILT_IN_ISGREATEREQUAL:
8040     case BUILT_IN_ISLESS:
8041     case BUILT_IN_ISLESSEQUAL:
8042     case BUILT_IN_ISLESSGREATER:
8043     case BUILT_IN_ISUNORDERED:
8044       if (builtin_function_validate_nargs (fndecl, nargs, 2))
8045         {
8046           enum tree_code code0, code1;
8047           code0 = TREE_CODE (TREE_TYPE (args[0]));
8048           code1 = TREE_CODE (TREE_TYPE (args[1]));
8049           if (!((code0 == REAL_TYPE && code1 == REAL_TYPE)
8050                 || (code0 == REAL_TYPE && code1 == INTEGER_TYPE)
8051                 || (code0 == INTEGER_TYPE && code1 == REAL_TYPE)))
8052             {
8053               error ("non-floating-point arguments in call to "
8054                      "function %qE", fndecl);
8055               return false;
8056             }
8057           return true;
8058         }
8059       return false;
8060
8061     case BUILT_IN_FPCLASSIFY:
8062       if (builtin_function_validate_nargs (fndecl, nargs, 6))
8063         {
8064           unsigned i;
8065
8066           for (i=0; i<5; i++)
8067             if (TREE_CODE (args[i]) != INTEGER_CST)
8068               {
8069                 error ("non-const integer argument %u in call to function %qE",
8070                        i+1, fndecl);
8071                 return false;
8072               }
8073
8074           if (TREE_CODE (TREE_TYPE (args[5])) != REAL_TYPE)
8075             {
8076               error ("non-floating-point argument in call to function %qE",
8077                      fndecl);
8078               return false;
8079             }
8080           return true;
8081         }
8082       return false;
8083
8084     default:
8085       return true;
8086     }
8087 }
8088
8089 /* Function to help qsort sort FIELD_DECLs by name order.  */
8090
8091 int
8092 field_decl_cmp (const void *x_p, const void *y_p)
8093 {
8094   const tree *const x = (const tree *const) x_p;
8095   const tree *const y = (const tree *const) y_p;
8096
8097   if (DECL_NAME (*x) == DECL_NAME (*y))
8098     /* A nontype is "greater" than a type.  */
8099     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
8100   if (DECL_NAME (*x) == NULL_TREE)
8101     return -1;
8102   if (DECL_NAME (*y) == NULL_TREE)
8103     return 1;
8104   if (DECL_NAME (*x) < DECL_NAME (*y))
8105     return -1;
8106   return 1;
8107 }
8108
8109 static struct {
8110   gt_pointer_operator new_value;
8111   void *cookie;
8112 } resort_data;
8113
8114 /* This routine compares two fields like field_decl_cmp but using the
8115 pointer operator in resort_data.  */
8116
8117 static int
8118 resort_field_decl_cmp (const void *x_p, const void *y_p)
8119 {
8120   const tree *const x = (const tree *const) x_p;
8121   const tree *const y = (const tree *const) y_p;
8122
8123   if (DECL_NAME (*x) == DECL_NAME (*y))
8124     /* A nontype is "greater" than a type.  */
8125     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
8126   if (DECL_NAME (*x) == NULL_TREE)
8127     return -1;
8128   if (DECL_NAME (*y) == NULL_TREE)
8129     return 1;
8130   {
8131     tree d1 = DECL_NAME (*x);
8132     tree d2 = DECL_NAME (*y);
8133     resort_data.new_value (&d1, resort_data.cookie);
8134     resort_data.new_value (&d2, resort_data.cookie);
8135     if (d1 < d2)
8136       return -1;
8137   }
8138   return 1;
8139 }
8140
8141 /* Resort DECL_SORTED_FIELDS because pointers have been reordered.  */
8142
8143 void
8144 resort_sorted_fields (void *obj,
8145                       void * ARG_UNUSED (orig_obj),
8146                       gt_pointer_operator new_value,
8147                       void *cookie)
8148 {
8149   struct sorted_fields_type *sf = (struct sorted_fields_type *) obj;
8150   resort_data.new_value = new_value;
8151   resort_data.cookie = cookie;
8152   qsort (&sf->elts[0], sf->len, sizeof (tree),
8153          resort_field_decl_cmp);
8154 }
8155
8156 /* Subroutine of c_parse_error.
8157    Return the result of concatenating LHS and RHS. RHS is really
8158    a string literal, its first character is indicated by RHS_START and
8159    RHS_SIZE is its length (including the terminating NUL character).
8160
8161    The caller is responsible for deleting the returned pointer.  */
8162
8163 static char *
8164 catenate_strings (const char *lhs, const char *rhs_start, int rhs_size)
8165 {
8166   const int lhs_size = strlen (lhs);
8167   char *result = XNEWVEC (char, lhs_size + rhs_size);
8168   strncpy (result, lhs, lhs_size);
8169   strncpy (result + lhs_size, rhs_start, rhs_size);
8170   return result;
8171 }
8172
8173 /* Issue the error given by GMSGID, indicating that it occurred before
8174    TOKEN, which had the associated VALUE.  */
8175
8176 void
8177 c_parse_error (const char *gmsgid, enum cpp_ttype token_type,
8178                tree value, unsigned char token_flags)
8179 {
8180 #define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2))
8181
8182   char *message = NULL;
8183
8184   if (token_type == CPP_EOF)
8185     message = catenate_messages (gmsgid, " at end of input");
8186   else if (token_type == CPP_CHAR
8187            || token_type == CPP_WCHAR
8188            || token_type == CPP_CHAR16
8189            || token_type == CPP_CHAR32)
8190     {
8191       unsigned int val = TREE_INT_CST_LOW (value);
8192       const char *prefix;
8193
8194       switch (token_type)
8195         {
8196         default:
8197           prefix = "";
8198           break;
8199         case CPP_WCHAR:
8200           prefix = "L";
8201           break;
8202         case CPP_CHAR16:
8203           prefix = "u";
8204           break;
8205         case CPP_CHAR32:
8206           prefix = "U";
8207           break;
8208         }
8209
8210       if (val <= UCHAR_MAX && ISGRAPH (val))
8211         message = catenate_messages (gmsgid, " before %s'%c'");
8212       else
8213         message = catenate_messages (gmsgid, " before %s'\\x%x'");
8214
8215       error (message, prefix, val);
8216       free (message);
8217       message = NULL;
8218     }
8219   else if (token_type == CPP_STRING
8220            || token_type == CPP_WSTRING
8221            || token_type == CPP_STRING16
8222            || token_type == CPP_STRING32
8223            || token_type == CPP_UTF8STRING)
8224     message = catenate_messages (gmsgid, " before string constant");
8225   else if (token_type == CPP_NUMBER)
8226     message = catenate_messages (gmsgid, " before numeric constant");
8227   else if (token_type == CPP_NAME)
8228     {
8229       message = catenate_messages (gmsgid, " before %qE");
8230       error (message, value);
8231       free (message);
8232       message = NULL;
8233     }
8234   else if (token_type == CPP_PRAGMA)
8235     message = catenate_messages (gmsgid, " before %<#pragma%>");
8236   else if (token_type == CPP_PRAGMA_EOL)
8237     message = catenate_messages (gmsgid, " before end of line");
8238   else if (token_type < N_TTYPES)
8239     {
8240       message = catenate_messages (gmsgid, " before %qs token");
8241       error (message, cpp_type2name (token_type, token_flags));
8242       free (message);
8243       message = NULL;
8244     }
8245   else
8246     error (gmsgid);
8247
8248   if (message)
8249     {
8250       error (message);
8251       free (message);
8252     }
8253 #undef catenate_messages
8254 }
8255
8256 /* Callback from cpp_error for PFILE to print diagnostics from the
8257    preprocessor.  The diagnostic is of type LEVEL, at location
8258    LOCATION unless this is after lexing and the compiler's location
8259    should be used instead, with column number possibly overridden by
8260    COLUMN_OVERRIDE if not zero; MSG is the translated message and AP
8261    the arguments.  Returns true if a diagnostic was emitted, false
8262    otherwise.  */
8263
8264 bool
8265 c_cpp_error (cpp_reader *pfile ATTRIBUTE_UNUSED, int level,
8266              location_t location, unsigned int column_override,
8267              const char *msg, va_list *ap)
8268 {
8269   diagnostic_info diagnostic;
8270   diagnostic_t dlevel;
8271   int save_warn_system_headers = warn_system_headers;
8272   bool ret;
8273
8274   switch (level)
8275     {
8276     case CPP_DL_WARNING_SYSHDR:
8277       if (flag_no_output)
8278         return false;
8279       warn_system_headers = 1;
8280       /* Fall through.  */
8281     case CPP_DL_WARNING:
8282       if (flag_no_output)
8283         return false;
8284       dlevel = DK_WARNING;
8285       break;
8286     case CPP_DL_PEDWARN:
8287       if (flag_no_output && !flag_pedantic_errors)
8288         return false;
8289       dlevel = DK_PEDWARN;
8290       break;
8291     case CPP_DL_ERROR:
8292       dlevel = DK_ERROR;
8293       break;
8294     case CPP_DL_ICE:
8295       dlevel = DK_ICE;
8296       break;
8297     case CPP_DL_NOTE:
8298       dlevel = DK_NOTE;
8299       break;
8300     case CPP_DL_FATAL:
8301       dlevel = DK_FATAL;
8302       break;
8303     default:
8304       gcc_unreachable ();
8305     }
8306   if (done_lexing)
8307     location = input_location;
8308   diagnostic_set_info_translated (&diagnostic, msg, ap,
8309                                   location, dlevel);
8310   if (column_override)
8311     diagnostic_override_column (&diagnostic, column_override);
8312   ret = report_diagnostic (&diagnostic);
8313   if (level == CPP_DL_WARNING_SYSHDR)
8314     warn_system_headers = save_warn_system_headers;
8315   return ret;
8316 }
8317
8318 /* Convert a character from the host to the target execution character
8319    set.  cpplib handles this, mostly.  */
8320
8321 HOST_WIDE_INT
8322 c_common_to_target_charset (HOST_WIDE_INT c)
8323 {
8324   /* Character constants in GCC proper are sign-extended under -fsigned-char,
8325      zero-extended under -fno-signed-char.  cpplib insists that characters
8326      and character constants are always unsigned.  Hence we must convert
8327      back and forth.  */
8328   cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1);
8329
8330   uc = cpp_host_to_exec_charset (parse_in, uc);
8331
8332   if (flag_signed_char)
8333     return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE)
8334                                >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE);
8335   else
8336     return uc;
8337 }
8338
8339 /* Build the result of __builtin_offsetof.  EXPR is a nested sequence of
8340    component references, with STOP_REF, or alternatively an INDIRECT_REF of
8341    NULL, at the bottom; much like the traditional rendering of offsetof as a
8342    macro.  Returns the folded and properly cast result.  */
8343
8344 static tree
8345 fold_offsetof_1 (tree expr, tree stop_ref)
8346 {
8347   enum tree_code code = PLUS_EXPR;
8348   tree base, off, t;
8349
8350   if (expr == stop_ref && TREE_CODE (expr) != ERROR_MARK)
8351     return size_zero_node;
8352
8353   switch (TREE_CODE (expr))
8354     {
8355     case ERROR_MARK:
8356       return expr;
8357
8358     case VAR_DECL:
8359       error ("cannot apply %<offsetof%> to static data member %qD", expr);
8360       return error_mark_node;
8361
8362     case CALL_EXPR:
8363     case TARGET_EXPR:
8364       error ("cannot apply %<offsetof%> when %<operator[]%> is overloaded");
8365       return error_mark_node;
8366
8367     case NOP_EXPR:
8368     case INDIRECT_REF:
8369       if (!integer_zerop (TREE_OPERAND (expr, 0)))
8370         {
8371           error ("cannot apply %<offsetof%> to a non constant address");
8372           return error_mark_node;
8373         }
8374       return size_zero_node;
8375
8376     case COMPONENT_REF:
8377       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
8378       if (base == error_mark_node)
8379         return base;
8380
8381       t = TREE_OPERAND (expr, 1);
8382       if (DECL_C_BIT_FIELD (t))
8383         {
8384           error ("attempt to take address of bit-field structure "
8385                  "member %qD", t);
8386           return error_mark_node;
8387         }
8388       off = size_binop_loc (input_location, PLUS_EXPR, DECL_FIELD_OFFSET (t),
8389                             size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t),
8390                                                     1)
8391                                       / BITS_PER_UNIT));
8392       break;
8393
8394     case ARRAY_REF:
8395       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
8396       if (base == error_mark_node)
8397         return base;
8398
8399       t = TREE_OPERAND (expr, 1);
8400       if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0)
8401         {
8402           code = MINUS_EXPR;
8403           t = fold_build1_loc (input_location, NEGATE_EXPR, TREE_TYPE (t), t);
8404         }
8405       t = convert (sizetype, t);
8406       off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
8407
8408       /* Check if the offset goes beyond the upper bound of the array.  */
8409       if (code == PLUS_EXPR && TREE_CODE (t) == INTEGER_CST)
8410         {
8411           tree upbound = array_ref_up_bound (expr);
8412           if (upbound != NULL_TREE
8413               && TREE_CODE (upbound) == INTEGER_CST
8414               && !tree_int_cst_equal (upbound,
8415                                       TYPE_MAX_VALUE (TREE_TYPE (upbound))))
8416             {
8417               upbound = size_binop (PLUS_EXPR, upbound,
8418                                     build_int_cst (TREE_TYPE (upbound), 1));
8419               if (tree_int_cst_lt (upbound, t))
8420                 {
8421                   tree v;
8422
8423                   for (v = TREE_OPERAND (expr, 0);
8424                        TREE_CODE (v) == COMPONENT_REF;
8425                        v = TREE_OPERAND (v, 0))
8426                     if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
8427                         == RECORD_TYPE)
8428                       {
8429                         tree fld_chain = TREE_CHAIN (TREE_OPERAND (v, 1));
8430                         for (; fld_chain; fld_chain = TREE_CHAIN (fld_chain))
8431                           if (TREE_CODE (fld_chain) == FIELD_DECL)
8432                             break;
8433
8434                         if (fld_chain)
8435                           break;
8436                       }
8437                   /* Don't warn if the array might be considered a poor
8438                      man's flexible array member with a very permissive
8439                      definition thereof.  */
8440                   if (TREE_CODE (v) == ARRAY_REF
8441                       || TREE_CODE (v) == COMPONENT_REF)
8442                     warning (OPT_Warray_bounds,
8443                              "index %E denotes an offset "
8444                              "greater than size of %qT",
8445                              t, TREE_TYPE (TREE_OPERAND (expr, 0)));
8446                 }
8447             }
8448         }
8449       break;
8450
8451     case COMPOUND_EXPR:
8452       /* Handle static members of volatile structs.  */
8453       t = TREE_OPERAND (expr, 1);
8454       gcc_assert (TREE_CODE (t) == VAR_DECL);
8455       return fold_offsetof_1 (t, stop_ref);
8456
8457     default:
8458       gcc_unreachable ();
8459     }
8460
8461   return size_binop (code, base, off);
8462 }
8463
8464 tree
8465 fold_offsetof (tree expr, tree stop_ref)
8466 {
8467   /* Convert back from the internal sizetype to size_t.  */
8468   return convert (size_type_node, fold_offsetof_1 (expr, stop_ref));
8469 }
8470
8471 /* Print an error message for an invalid lvalue.  USE says
8472    how the lvalue is being used and so selects the error message.  */
8473
8474 void
8475 lvalue_error (enum lvalue_use use)
8476 {
8477   switch (use)
8478     {
8479     case lv_assign:
8480       error ("lvalue required as left operand of assignment");
8481       break;
8482     case lv_increment:
8483       error ("lvalue required as increment operand");
8484       break;
8485     case lv_decrement:
8486       error ("lvalue required as decrement operand");
8487       break;
8488     case lv_addressof:
8489       error ("lvalue required as unary %<&%> operand");
8490       break;
8491     case lv_asm:
8492       error ("lvalue required in asm statement");
8493       break;
8494     default:
8495       gcc_unreachable ();
8496     }
8497 }
8498 \f
8499 /* *PTYPE is an incomplete array.  Complete it with a domain based on
8500    INITIAL_VALUE.  If INITIAL_VALUE is not present, use 1 if DO_DEFAULT
8501    is true.  Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered,
8502    2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty.  */
8503
8504 int
8505 complete_array_type (tree *ptype, tree initial_value, bool do_default)
8506 {
8507   tree maxindex, type, main_type, elt, unqual_elt;
8508   int failure = 0, quals;
8509   hashval_t hashcode = 0;
8510
8511   maxindex = size_zero_node;
8512   if (initial_value)
8513     {
8514       if (TREE_CODE (initial_value) == STRING_CST)
8515         {
8516           int eltsize
8517             = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value)));
8518           maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1);
8519         }
8520       else if (TREE_CODE (initial_value) == CONSTRUCTOR)
8521         {
8522           VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (initial_value);
8523
8524           if (VEC_empty (constructor_elt, v))
8525             {
8526               if (pedantic)
8527                 failure = 3;
8528               maxindex = integer_minus_one_node;
8529             }
8530           else
8531             {
8532               tree curindex;
8533               unsigned HOST_WIDE_INT cnt;
8534               constructor_elt *ce;
8535               bool fold_p = false;
8536
8537               if (VEC_index (constructor_elt, v, 0)->index)
8538                 maxindex = fold_convert_loc (input_location, sizetype,
8539                                              VEC_index (constructor_elt,
8540                                                         v, 0)->index);
8541               curindex = maxindex;
8542
8543               for (cnt = 1;
8544                    VEC_iterate (constructor_elt, v, cnt, ce);
8545                    cnt++)
8546                 {
8547                   bool curfold_p = false;
8548                   if (ce->index)
8549                     curindex = ce->index, curfold_p = true;
8550                   else
8551                     {
8552                       if (fold_p)
8553                         curindex = fold_convert (sizetype, curindex);
8554                       curindex = size_binop (PLUS_EXPR, curindex,
8555                                              size_one_node);
8556                     }
8557                   if (tree_int_cst_lt (maxindex, curindex))
8558                     maxindex = curindex, fold_p = curfold_p;
8559                 }
8560                if (fold_p)
8561                  maxindex = fold_convert (sizetype, maxindex);
8562             }
8563         }
8564       else
8565         {
8566           /* Make an error message unless that happened already.  */
8567           if (initial_value != error_mark_node)
8568             failure = 1;
8569         }
8570     }
8571   else
8572     {
8573       failure = 2;
8574       if (!do_default)
8575         return failure;
8576     }
8577
8578   type = *ptype;
8579   elt = TREE_TYPE (type);
8580   quals = TYPE_QUALS (strip_array_types (elt));
8581   if (quals == 0)
8582     unqual_elt = elt;
8583   else
8584     unqual_elt = c_build_qualified_type (elt, KEEP_QUAL_ADDR_SPACE (quals));
8585
8586   /* Using build_distinct_type_copy and modifying things afterward instead
8587      of using build_array_type to create a new type preserves all of the
8588      TYPE_LANG_FLAG_? bits that the front end may have set.  */
8589   main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
8590   TREE_TYPE (main_type) = unqual_elt;
8591   TYPE_DOMAIN (main_type) = build_index_type (maxindex);
8592   layout_type (main_type);
8593
8594   /* Make sure we have the canonical MAIN_TYPE. */
8595   hashcode = iterative_hash_object (TYPE_HASH (unqual_elt), hashcode);
8596   hashcode = iterative_hash_object (TYPE_HASH (TYPE_DOMAIN (main_type)),
8597                                     hashcode);
8598   main_type = type_hash_canon (hashcode, main_type);
8599
8600   /* Fix the canonical type.  */
8601   if (TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (main_type))
8602       || TYPE_STRUCTURAL_EQUALITY_P (TYPE_DOMAIN (main_type)))
8603     SET_TYPE_STRUCTURAL_EQUALITY (main_type);
8604   else if (TYPE_CANONICAL (TREE_TYPE (main_type)) != TREE_TYPE (main_type)
8605            || (TYPE_CANONICAL (TYPE_DOMAIN (main_type))
8606                != TYPE_DOMAIN (main_type)))
8607     TYPE_CANONICAL (main_type)
8608       = build_array_type (TYPE_CANONICAL (TREE_TYPE (main_type)),
8609                           TYPE_CANONICAL (TYPE_DOMAIN (main_type)));
8610   else
8611     TYPE_CANONICAL (main_type) = main_type;
8612
8613   if (quals == 0)
8614     type = main_type;
8615   else
8616     type = c_build_qualified_type (main_type, quals);
8617
8618   if (COMPLETE_TYPE_P (type)
8619       && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST
8620       && TREE_OVERFLOW (TYPE_SIZE_UNIT (type)))
8621     {
8622       error ("size of array is too large");
8623       /* If we proceed with the array type as it is, we'll eventually
8624          crash in tree_low_cst().  */
8625       type = error_mark_node;
8626     }
8627
8628   *ptype = type;
8629   return failure;
8630 }
8631
8632 \f
8633 /* Used to help initialize the builtin-types.def table.  When a type of
8634    the correct size doesn't exist, use error_mark_node instead of NULL.
8635    The later results in segfaults even when a decl using the type doesn't
8636    get invoked.  */
8637
8638 tree
8639 builtin_type_for_size (int size, bool unsignedp)
8640 {
8641   tree type = lang_hooks.types.type_for_size (size, unsignedp);
8642   return type ? type : error_mark_node;
8643 }
8644
8645 /* A helper function for resolve_overloaded_builtin in resolving the
8646    overloaded __sync_ builtins.  Returns a positive power of 2 if the
8647    first operand of PARAMS is a pointer to a supported data type.
8648    Returns 0 if an error is encountered.  */
8649
8650 static int
8651 sync_resolve_size (tree function, VEC(tree,gc) *params)
8652 {
8653   tree type;
8654   int size;
8655
8656   if (VEC_empty (tree, params))
8657     {
8658       error ("too few arguments to function %qE", function);
8659       return 0;
8660     }
8661
8662   type = TREE_TYPE (VEC_index (tree, params, 0));
8663   if (TREE_CODE (type) != POINTER_TYPE)
8664     goto incompatible;
8665
8666   type = TREE_TYPE (type);
8667   if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
8668     goto incompatible;
8669
8670   size = tree_low_cst (TYPE_SIZE_UNIT (type), 1);
8671   if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16)
8672     return size;
8673
8674  incompatible:
8675   error ("incompatible type for argument %d of %qE", 1, function);
8676   return 0;
8677 }
8678
8679 /* A helper function for resolve_overloaded_builtin.  Adds casts to
8680    PARAMS to make arguments match up with those of FUNCTION.  Drops
8681    the variadic arguments at the end.  Returns false if some error
8682    was encountered; true on success.  */
8683
8684 static bool
8685 sync_resolve_params (tree orig_function, tree function, VEC(tree, gc) *params)
8686 {
8687   tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (function));
8688   tree ptype;
8689   int number;
8690   unsigned int parmnum;
8691
8692   /* We've declared the implementation functions to use "volatile void *"
8693      as the pointer parameter, so we shouldn't get any complaints from the
8694      call to check_function_arguments what ever type the user used.  */
8695   arg_types = TREE_CHAIN (arg_types);
8696   ptype = TREE_TYPE (TREE_TYPE (VEC_index (tree, params, 0)));
8697   number = 2;
8698
8699   /* For the rest of the values, we need to cast these to FTYPE, so that we
8700      don't get warnings for passing pointer types, etc.  */
8701   parmnum = 0;
8702   while (arg_types != void_list_node)
8703     {
8704       tree val;
8705
8706       ++parmnum;
8707       if (VEC_length (tree, params) <= parmnum)
8708         {
8709           error ("too few arguments to function %qE", orig_function);
8710           return false;
8711         }
8712
8713       /* ??? Ideally for the first conversion we'd use convert_for_assignment
8714          so that we get warnings for anything that doesn't match the pointer
8715          type.  This isn't portable across the C and C++ front ends atm.  */
8716       val = VEC_index (tree, params, parmnum);
8717       val = convert (ptype, val);
8718       val = convert (TREE_VALUE (arg_types), val);
8719       VEC_replace (tree, params, parmnum, val);
8720
8721       arg_types = TREE_CHAIN (arg_types);
8722       number++;
8723     }
8724
8725   /* The definition of these primitives is variadic, with the remaining
8726      being "an optional list of variables protected by the memory barrier".
8727      No clue what that's supposed to mean, precisely, but we consider all
8728      call-clobbered variables to be protected so we're safe.  */
8729   VEC_truncate (tree, params, parmnum + 1);
8730
8731   return true;
8732 }
8733
8734 /* A helper function for resolve_overloaded_builtin.  Adds a cast to
8735    RESULT to make it match the type of the first pointer argument in
8736    PARAMS.  */
8737
8738 static tree
8739 sync_resolve_return (tree first_param, tree result)
8740 {
8741   tree ptype = TREE_TYPE (TREE_TYPE (first_param));
8742   ptype = TYPE_MAIN_VARIANT (ptype);
8743   return convert (ptype, result);
8744 }
8745
8746 /* Some builtin functions are placeholders for other expressions.  This
8747    function should be called immediately after parsing the call expression
8748    before surrounding code has committed to the type of the expression.
8749
8750    LOC is the location of the builtin call.
8751
8752    FUNCTION is the DECL that has been invoked; it is known to be a builtin.
8753    PARAMS is the argument list for the call.  The return value is non-null
8754    when expansion is complete, and null if normal processing should
8755    continue.  */
8756
8757 tree
8758 resolve_overloaded_builtin (location_t loc, tree function, VEC(tree,gc) *params)
8759 {
8760   enum built_in_function orig_code = DECL_FUNCTION_CODE (function);
8761   switch (DECL_BUILT_IN_CLASS (function))
8762     {
8763     case BUILT_IN_NORMAL:
8764       break;
8765     case BUILT_IN_MD:
8766       if (targetm.resolve_overloaded_builtin)
8767         return targetm.resolve_overloaded_builtin (loc, function, params);
8768       else
8769         return NULL_TREE;
8770     default:
8771       return NULL_TREE;
8772     }
8773
8774   /* Handle BUILT_IN_NORMAL here.  */
8775   switch (orig_code)
8776     {
8777     case BUILT_IN_FETCH_AND_ADD_N:
8778     case BUILT_IN_FETCH_AND_SUB_N:
8779     case BUILT_IN_FETCH_AND_OR_N:
8780     case BUILT_IN_FETCH_AND_AND_N:
8781     case BUILT_IN_FETCH_AND_XOR_N:
8782     case BUILT_IN_FETCH_AND_NAND_N:
8783     case BUILT_IN_ADD_AND_FETCH_N:
8784     case BUILT_IN_SUB_AND_FETCH_N:
8785     case BUILT_IN_OR_AND_FETCH_N:
8786     case BUILT_IN_AND_AND_FETCH_N:
8787     case BUILT_IN_XOR_AND_FETCH_N:
8788     case BUILT_IN_NAND_AND_FETCH_N:
8789     case BUILT_IN_BOOL_COMPARE_AND_SWAP_N:
8790     case BUILT_IN_VAL_COMPARE_AND_SWAP_N:
8791     case BUILT_IN_LOCK_TEST_AND_SET_N:
8792     case BUILT_IN_LOCK_RELEASE_N:
8793       {
8794         int n = sync_resolve_size (function, params);
8795         tree new_function, first_param, result;
8796
8797         if (n == 0)
8798           return error_mark_node;
8799
8800         new_function = built_in_decls[orig_code + exact_log2 (n) + 1];
8801         if (!sync_resolve_params (function, new_function, params))
8802           return error_mark_node;
8803
8804         first_param = VEC_index (tree, params, 0);
8805         result = build_function_call_vec (loc, new_function, params, NULL);
8806         if (orig_code != BUILT_IN_BOOL_COMPARE_AND_SWAP_N
8807             && orig_code != BUILT_IN_LOCK_RELEASE_N)
8808           result = sync_resolve_return (first_param, result);
8809
8810         return result;
8811       }
8812
8813     default:
8814       return NULL_TREE;
8815     }
8816 }
8817
8818 /* Ignoring their sign, return true if two scalar types are the same.  */
8819 bool
8820 same_scalar_type_ignoring_signedness (tree t1, tree t2)
8821 {
8822   enum tree_code c1 = TREE_CODE (t1), c2 = TREE_CODE (t2);
8823
8824   gcc_assert ((c1 == INTEGER_TYPE || c1 == REAL_TYPE || c1 == FIXED_POINT_TYPE)
8825               && (c2 == INTEGER_TYPE || c2 == REAL_TYPE
8826                   || c2 == FIXED_POINT_TYPE));
8827
8828   /* Equality works here because c_common_signed_type uses
8829      TYPE_MAIN_VARIANT.  */
8830   return c_common_signed_type (t1)
8831     == c_common_signed_type (t2);
8832 }
8833
8834 /* Check for missing format attributes on function pointers.  LTYPE is
8835    the new type or left-hand side type.  RTYPE is the old type or
8836    right-hand side type.  Returns TRUE if LTYPE is missing the desired
8837    attribute.  */
8838
8839 bool
8840 check_missing_format_attribute (tree ltype, tree rtype)
8841 {
8842   tree const ttr = TREE_TYPE (rtype), ttl = TREE_TYPE (ltype);
8843   tree ra;
8844
8845   for (ra = TYPE_ATTRIBUTES (ttr); ra; ra = TREE_CHAIN (ra))
8846     if (is_attribute_p ("format", TREE_PURPOSE (ra)))
8847       break;
8848   if (ra)
8849     {
8850       tree la;
8851       for (la = TYPE_ATTRIBUTES (ttl); la; la = TREE_CHAIN (la))
8852         if (is_attribute_p ("format", TREE_PURPOSE (la)))
8853           break;
8854       return !la;
8855     }
8856   else
8857     return false;
8858 }
8859
8860 /* Subscripting with type char is likely to lose on a machine where
8861    chars are signed.  So warn on any machine, but optionally.  Don't
8862    warn for unsigned char since that type is safe.  Don't warn for
8863    signed char because anyone who uses that must have done so
8864    deliberately. Furthermore, we reduce the false positive load by
8865    warning only for non-constant value of type char.  */
8866
8867 void
8868 warn_array_subscript_with_type_char (tree index)
8869 {
8870   if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node
8871       && TREE_CODE (index) != INTEGER_CST)
8872     warning (OPT_Wchar_subscripts, "array subscript has type %<char%>");
8873 }
8874
8875 /* Implement -Wparentheses for the unexpected C precedence rules, to
8876    cover cases like x + y << z which readers are likely to
8877    misinterpret.  We have seen an expression in which CODE is a binary
8878    operator used to combine expressions ARG_LEFT and ARG_RIGHT, which
8879    before folding had CODE_LEFT and CODE_RIGHT.  CODE_LEFT and
8880    CODE_RIGHT may be ERROR_MARK, which means that that side of the
8881    expression was not formed using a binary or unary operator, or it
8882    was enclosed in parentheses.  */
8883
8884 void
8885 warn_about_parentheses (enum tree_code code,
8886                         enum tree_code code_left, tree arg_left,
8887                         enum tree_code code_right, tree arg_right)
8888 {
8889   if (!warn_parentheses)
8890     return;
8891
8892   /* This macro tests that the expression ARG with original tree code
8893      CODE appears to be a boolean expression. or the result of folding a
8894      boolean expression.  */
8895 #define APPEARS_TO_BE_BOOLEAN_EXPR_P(CODE, ARG)                             \
8896         (truth_value_p (TREE_CODE (ARG))                                    \
8897          || TREE_CODE (TREE_TYPE (ARG)) == BOOLEAN_TYPE                     \
8898          /* Folding may create 0 or 1 integers from other expressions.  */  \
8899          || ((CODE) != INTEGER_CST                                          \
8900              && (integer_onep (ARG) || integer_zerop (ARG))))
8901
8902   switch (code)
8903     {
8904     case LSHIFT_EXPR:
8905       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8906         warning (OPT_Wparentheses,
8907                  "suggest parentheses around %<+%> inside %<<<%>");
8908       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8909         warning (OPT_Wparentheses,
8910                  "suggest parentheses around %<-%> inside %<<<%>");
8911       return;
8912
8913     case RSHIFT_EXPR:
8914       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8915         warning (OPT_Wparentheses,
8916                  "suggest parentheses around %<+%> inside %<>>%>");
8917       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8918         warning (OPT_Wparentheses,
8919                  "suggest parentheses around %<-%> inside %<>>%>");
8920       return;
8921
8922     case TRUTH_ORIF_EXPR:
8923       if (code_left == TRUTH_ANDIF_EXPR || code_right == TRUTH_ANDIF_EXPR)
8924         warning (OPT_Wparentheses,
8925                  "suggest parentheses around %<&&%> within %<||%>");
8926       return;
8927
8928     case BIT_IOR_EXPR:
8929       if (code_left == BIT_AND_EXPR || code_left == BIT_XOR_EXPR
8930           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
8931           || code_right == BIT_AND_EXPR || code_right == BIT_XOR_EXPR
8932           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
8933         warning (OPT_Wparentheses,
8934                  "suggest parentheses around arithmetic in operand of %<|%>");
8935       /* Check cases like x|y==z */
8936       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8937                || TREE_CODE_CLASS (code_right) == tcc_comparison)
8938         warning (OPT_Wparentheses,
8939                  "suggest parentheses around comparison in operand of %<|%>");
8940       /* Check cases like !x | y */
8941       else if (code_left == TRUTH_NOT_EXPR
8942                && !APPEARS_TO_BE_BOOLEAN_EXPR_P (code_right, arg_right))
8943         warning (OPT_Wparentheses, "suggest parentheses around operand of "
8944                  "%<!%> or change %<|%> to %<||%> or %<!%> to %<~%>");
8945       return;
8946
8947     case BIT_XOR_EXPR:
8948       if (code_left == BIT_AND_EXPR
8949           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
8950           || code_right == BIT_AND_EXPR
8951           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
8952         warning (OPT_Wparentheses,
8953                  "suggest parentheses around arithmetic in operand of %<^%>");
8954       /* Check cases like x^y==z */
8955       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8956                || TREE_CODE_CLASS (code_right) == tcc_comparison)
8957         warning (OPT_Wparentheses,
8958                  "suggest parentheses around comparison in operand of %<^%>");
8959       return;
8960
8961     case BIT_AND_EXPR:
8962       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8963         warning (OPT_Wparentheses,
8964                  "suggest parentheses around %<+%> in operand of %<&%>");
8965       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8966         warning (OPT_Wparentheses,
8967                  "suggest parentheses around %<-%> in operand of %<&%>");
8968       /* Check cases like x&y==z */
8969       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8970                || TREE_CODE_CLASS (code_right) == tcc_comparison)
8971         warning (OPT_Wparentheses,
8972                  "suggest parentheses around comparison in operand of %<&%>");
8973       /* Check cases like !x & y */
8974       else if (code_left == TRUTH_NOT_EXPR
8975                && !APPEARS_TO_BE_BOOLEAN_EXPR_P (code_right, arg_right))
8976         warning (OPT_Wparentheses, "suggest parentheses around operand of "
8977                  "%<!%> or change %<&%> to %<&&%> or %<!%> to %<~%>");
8978       return;
8979
8980     case EQ_EXPR:
8981       if (TREE_CODE_CLASS (code_left) == tcc_comparison
8982           || TREE_CODE_CLASS (code_right) == tcc_comparison)
8983         warning (OPT_Wparentheses,
8984                  "suggest parentheses around comparison in operand of %<==%>");
8985       return;
8986     case NE_EXPR:
8987       if (TREE_CODE_CLASS (code_left) == tcc_comparison
8988           || TREE_CODE_CLASS (code_right) == tcc_comparison)
8989         warning (OPT_Wparentheses,
8990                  "suggest parentheses around comparison in operand of %<!=%>");
8991       return;
8992
8993     default:
8994       if (TREE_CODE_CLASS (code) == tcc_comparison
8995            && ((TREE_CODE_CLASS (code_left) == tcc_comparison
8996                 && code_left != NE_EXPR && code_left != EQ_EXPR
8997                 && INTEGRAL_TYPE_P (TREE_TYPE (arg_left)))
8998                || (TREE_CODE_CLASS (code_right) == tcc_comparison
8999                    && code_right != NE_EXPR && code_right != EQ_EXPR
9000                    && INTEGRAL_TYPE_P (TREE_TYPE (arg_right)))))
9001         warning (OPT_Wparentheses, "comparisons like %<X<=Y<=Z%> do not "
9002                  "have their mathematical meaning");
9003       return;
9004     }
9005 #undef NOT_A_BOOLEAN_EXPR_P
9006 }
9007
9008 /* If LABEL (a LABEL_DECL) has not been used, issue a warning.  */
9009
9010 void
9011 warn_for_unused_label (tree label)
9012 {
9013   if (!TREE_USED (label))
9014     {
9015       if (DECL_INITIAL (label))
9016         warning (OPT_Wunused_label, "label %q+D defined but not used", label);
9017       else
9018         warning (OPT_Wunused_label, "label %q+D declared but not defined", label);
9019     }
9020 }
9021
9022 #ifndef TARGET_HAS_TARGETCM
9023 struct gcc_targetcm targetcm = TARGETCM_INITIALIZER;
9024 #endif
9025
9026 /* Warn for division by zero according to the value of DIVISOR.  LOC
9027    is the location of the division operator.  */
9028
9029 void
9030 warn_for_div_by_zero (location_t loc, tree divisor)
9031 {
9032   /* If DIVISOR is zero, and has integral or fixed-point type, issue a warning
9033      about division by zero.  Do not issue a warning if DIVISOR has a
9034      floating-point type, since we consider 0.0/0.0 a valid way of
9035      generating a NaN.  */
9036   if (c_inhibit_evaluation_warnings == 0
9037       && (integer_zerop (divisor) || fixed_zerop (divisor)))
9038     warning_at (loc, OPT_Wdiv_by_zero, "division by zero");
9039 }
9040
9041 /* Subroutine of build_binary_op. Give warnings for comparisons
9042    between signed and unsigned quantities that may fail. Do the
9043    checking based on the original operand trees ORIG_OP0 and ORIG_OP1,
9044    so that casts will be considered, but default promotions won't
9045    be.
9046
9047    LOCATION is the location of the comparison operator.
9048
9049    The arguments of this function map directly to local variables
9050    of build_binary_op.  */
9051
9052 void
9053 warn_for_sign_compare (location_t location,
9054                        tree orig_op0, tree orig_op1,
9055                        tree op0, tree op1,
9056                        tree result_type, enum tree_code resultcode)
9057 {
9058   int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
9059   int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
9060   int unsignedp0, unsignedp1;
9061
9062   /* In C++, check for comparison of different enum types.  */
9063   if (c_dialect_cxx()
9064       && TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
9065       && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
9066       && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
9067          != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
9068     {
9069       warning_at (location,
9070                   OPT_Wsign_compare, "comparison between types %qT and %qT",
9071                   TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
9072     }
9073
9074   /* Do not warn if the comparison is being done in a signed type,
9075      since the signed type will only be chosen if it can represent
9076      all the values of the unsigned type.  */
9077   if (!TYPE_UNSIGNED (result_type))
9078     /* OK */;
9079   /* Do not warn if both operands are unsigned.  */
9080   else if (op0_signed == op1_signed)
9081     /* OK */;
9082   else
9083     {
9084       tree sop, uop, base_type;
9085       bool ovf;
9086
9087       if (op0_signed)
9088         sop = orig_op0, uop = orig_op1;
9089       else
9090         sop = orig_op1, uop = orig_op0;
9091
9092       STRIP_TYPE_NOPS (sop);
9093       STRIP_TYPE_NOPS (uop);
9094       base_type = (TREE_CODE (result_type) == COMPLEX_TYPE
9095                    ? TREE_TYPE (result_type) : result_type);
9096
9097       /* Do not warn if the signed quantity is an unsuffixed integer
9098          literal (or some static constant expression involving such
9099          literals or a conditional expression involving such literals)
9100          and it is non-negative.  */
9101       if (tree_expr_nonnegative_warnv_p (sop, &ovf))
9102         /* OK */;
9103       /* Do not warn if the comparison is an equality operation, the
9104          unsigned quantity is an integral constant, and it would fit
9105          in the result if the result were signed.  */
9106       else if (TREE_CODE (uop) == INTEGER_CST
9107                && (resultcode == EQ_EXPR || resultcode == NE_EXPR)
9108                && int_fits_type_p (uop, c_common_signed_type (base_type)))
9109         /* OK */;
9110       /* In C, do not warn if the unsigned quantity is an enumeration
9111          constant and its maximum value would fit in the result if the
9112          result were signed.  */
9113       else if (!c_dialect_cxx() && TREE_CODE (uop) == INTEGER_CST
9114                && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE
9115                && int_fits_type_p (TYPE_MAX_VALUE (TREE_TYPE (uop)),
9116                                    c_common_signed_type (base_type)))
9117         /* OK */;
9118       else
9119         warning_at (location,
9120                     OPT_Wsign_compare,
9121                     "comparison between signed and unsigned integer expressions");
9122     }
9123
9124   /* Warn if two unsigned values are being compared in a size larger
9125      than their original size, and one (and only one) is the result of
9126      a `~' operator.  This comparison will always fail.
9127
9128      Also warn if one operand is a constant, and the constant does not
9129      have all bits set that are set in the ~ operand when it is
9130      extended.  */
9131
9132   op0 = get_narrower (op0, &unsignedp0);
9133   op1 = get_narrower (op1, &unsignedp1);
9134
9135   if ((TREE_CODE (op0) == BIT_NOT_EXPR)
9136       ^ (TREE_CODE (op1) == BIT_NOT_EXPR))
9137     {
9138       if (TREE_CODE (op0) == BIT_NOT_EXPR)
9139         op0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
9140       if (TREE_CODE (op1) == BIT_NOT_EXPR)
9141         op1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
9142
9143       if (host_integerp (op0, 0) || host_integerp (op1, 0))
9144         {
9145           tree primop;
9146           HOST_WIDE_INT constant, mask;
9147           int unsignedp;
9148           unsigned int bits;
9149
9150           if (host_integerp (op0, 0))
9151             {
9152               primop = op1;
9153               unsignedp = unsignedp1;
9154               constant = tree_low_cst (op0, 0);
9155             }
9156           else
9157             {
9158               primop = op0;
9159               unsignedp = unsignedp0;
9160               constant = tree_low_cst (op1, 0);
9161             }
9162
9163           bits = TYPE_PRECISION (TREE_TYPE (primop));
9164           if (bits < TYPE_PRECISION (result_type)
9165               && bits < HOST_BITS_PER_LONG && unsignedp)
9166             {
9167               mask = (~ (HOST_WIDE_INT) 0) << bits;
9168               if ((mask & constant) != mask)
9169                 {
9170                   if (constant == 0)
9171                     warning (OPT_Wsign_compare,
9172                              "promoted ~unsigned is always non-zero");
9173                   else
9174                     warning_at (location, OPT_Wsign_compare,
9175                                 "comparison of promoted ~unsigned with constant");
9176                 }
9177             }
9178         }
9179       else if (unsignedp0 && unsignedp1
9180                && (TYPE_PRECISION (TREE_TYPE (op0))
9181                    < TYPE_PRECISION (result_type))
9182                && (TYPE_PRECISION (TREE_TYPE (op1))
9183                    < TYPE_PRECISION (result_type)))
9184         warning_at (location, OPT_Wsign_compare,
9185                  "comparison of promoted ~unsigned with unsigned");
9186     }
9187 }
9188
9189 /* Setup a TYPE_DECL node as a typedef representation.
9190
9191    X is a TYPE_DECL for a typedef statement.  Create a brand new
9192    ..._TYPE node (which will be just a variant of the existing
9193    ..._TYPE node with identical properties) and then install X
9194    as the TYPE_NAME of this brand new (duplicate) ..._TYPE node.
9195
9196    The whole point here is to end up with a situation where each
9197    and every ..._TYPE node the compiler creates will be uniquely
9198    associated with AT MOST one node representing a typedef name.
9199    This way, even though the compiler substitutes corresponding
9200    ..._TYPE nodes for TYPE_DECL (i.e. "typedef name") nodes very
9201    early on, later parts of the compiler can always do the reverse
9202    translation and get back the corresponding typedef name.  For
9203    example, given:
9204
9205         typedef struct S MY_TYPE;
9206         MY_TYPE object;
9207
9208    Later parts of the compiler might only know that `object' was of
9209    type `struct S' if it were not for code just below.  With this
9210    code however, later parts of the compiler see something like:
9211
9212         struct S' == struct S
9213         typedef struct S' MY_TYPE;
9214         struct S' object;
9215
9216     And they can then deduce (from the node for type struct S') that
9217     the original object declaration was:
9218
9219                 MY_TYPE object;
9220
9221     Being able to do this is important for proper support of protoize,
9222     and also for generating precise symbolic debugging information
9223     which takes full account of the programmer's (typedef) vocabulary.
9224
9225     Obviously, we don't want to generate a duplicate ..._TYPE node if
9226     the TYPE_DECL node that we are now processing really represents a
9227     standard built-in type.  */
9228
9229 void
9230 set_underlying_type (tree x)
9231 {
9232   if (x == error_mark_node)
9233     return;
9234   if (DECL_IS_BUILTIN (x))
9235     {
9236       if (TYPE_NAME (TREE_TYPE (x)) == 0)
9237         TYPE_NAME (TREE_TYPE (x)) = x;
9238     }
9239   else if (TREE_TYPE (x) != error_mark_node
9240            && DECL_ORIGINAL_TYPE (x) == NULL_TREE)
9241     {
9242       tree tt = TREE_TYPE (x);
9243       DECL_ORIGINAL_TYPE (x) = tt;
9244       tt = build_variant_type_copy (tt);
9245       TYPE_STUB_DECL (tt) = TYPE_STUB_DECL (DECL_ORIGINAL_TYPE (x));
9246       TYPE_NAME (tt) = x;
9247       TREE_USED (tt) = TREE_USED (x);
9248       TREE_TYPE (x) = tt;
9249     }
9250 }
9251
9252 /* Returns true if X is a typedef decl.  */
9253
9254 bool
9255 is_typedef_decl (tree x)
9256 {
9257   return (x && TREE_CODE (x) == TYPE_DECL
9258           && DECL_ORIGINAL_TYPE (x) != NULL_TREE);
9259 }
9260
9261 /* Record the types used by the current global variable declaration
9262    being parsed, so that we can decide later to emit their debug info.
9263    Those types are in types_used_by_cur_var_decl, and we are going to
9264    store them in the types_used_by_vars_hash hash table.
9265    DECL is the declaration of the global variable that has been parsed.  */
9266
9267 void
9268 record_types_used_by_current_var_decl (tree decl)
9269 {
9270   gcc_assert (decl && DECL_P (decl) && TREE_STATIC (decl));
9271
9272   if (types_used_by_cur_var_decl)
9273     {
9274       tree node;
9275       for (node = types_used_by_cur_var_decl;
9276            node;
9277            node = TREE_CHAIN (node))
9278       {
9279         tree type = TREE_PURPOSE (node);
9280         types_used_by_var_decl_insert (type, decl);
9281       }
9282       types_used_by_cur_var_decl = NULL;
9283     }
9284 }
9285
9286 /* The C and C++ parsers both use vectors to hold function arguments.
9287    For efficiency, we keep a cache of unused vectors.  This is the
9288    cache.  */
9289
9290 typedef VEC(tree,gc)* tree_gc_vec;
9291 DEF_VEC_P(tree_gc_vec);
9292 DEF_VEC_ALLOC_P(tree_gc_vec,gc);
9293 static GTY((deletable)) VEC(tree_gc_vec,gc) *tree_vector_cache;
9294
9295 /* Return a new vector from the cache.  If the cache is empty,
9296    allocate a new vector.  These vectors are GC'ed, so it is OK if the
9297    pointer is not released..  */
9298
9299 VEC(tree,gc) *
9300 make_tree_vector (void)
9301 {
9302   if (!VEC_empty (tree_gc_vec, tree_vector_cache))
9303     return VEC_pop (tree_gc_vec, tree_vector_cache);
9304   else
9305     {
9306       /* Passing 0 to VEC_alloc returns NULL, and our callers require
9307          that we always return a non-NULL value.  The vector code uses
9308          4 when growing a NULL vector, so we do too.  */
9309       return VEC_alloc (tree, gc, 4);
9310     }
9311 }
9312
9313 /* Release a vector of trees back to the cache.  */
9314
9315 void
9316 release_tree_vector (VEC(tree,gc) *vec)
9317 {
9318   if (vec != NULL)
9319     {
9320       VEC_truncate (tree, vec, 0);
9321       VEC_safe_push (tree_gc_vec, gc, tree_vector_cache, vec);
9322     }
9323 }
9324
9325 /* Get a new tree vector holding a single tree.  */
9326
9327 VEC(tree,gc) *
9328 make_tree_vector_single (tree t)
9329 {
9330   VEC(tree,gc) *ret = make_tree_vector ();
9331   VEC_quick_push (tree, ret, t);
9332   return ret;
9333 }
9334
9335 /* Get a new tree vector which is a copy of an existing one.  */
9336
9337 VEC(tree,gc) *
9338 make_tree_vector_copy (const VEC(tree,gc) *orig)
9339 {
9340   VEC(tree,gc) *ret;
9341   unsigned int ix;
9342   tree t;
9343
9344   ret = make_tree_vector ();
9345   VEC_reserve (tree, gc, ret, VEC_length (tree, orig));
9346   for (ix = 0; VEC_iterate (tree, orig, ix, t); ++ix)
9347     VEC_quick_push (tree, ret, t);
9348   return ret;
9349 }
9350
9351 #include "gt-c-common.h"