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