gcc/c-common.c

   1 /* Subroutines shared by all languages that are variants of C.
   2    Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
   3    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
   4    Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "intl.h"
  27 #include "tree.h"
  28 #include "flags.h"
  29 #include "output.h"
  30 #include "c-pragma.h"
  31 #include "rtl.h"
  32 #include "ggc.h"
  33 #include "varray.h"
  34 #include "expr.h"
  35 #include "c-common.h"
  36 #include "tm_p.h"
  37 #include "obstack.h"
  38 #include "cpplib.h"
  39 #include "target.h"
  40 #include "langhooks.h"
  41 #include "tree-inline.h"
  42 #include "c-tree.h"
  43 #include "toplev.h"
  44 #include "diagnostic.h"
  45 #include "tree-iterator.h"
  46 #include "hashtab.h"
  47 #include "tree-mudflap.h"
  48 #include "opts.h"
  49 #include "real.h"
  50 #include "cgraph.h"
  51 #include "target-def.h"
  52 #include "gimple.h"
  53 #include "fixed-value.h"
  54 #include "libfuncs.h"
  55
  56 cpp_reader *parse_in;           /* Declared in c-pragma.h.  */
  57
  58 /* The following symbols are subsumed in the c_global_trees array, and
  59    listed here individually for documentation purposes.
  60
  61    INTEGER_TYPE and REAL_TYPE nodes for the standard data types.
  62
  63         tree short_integer_type_node;
  64         tree long_integer_type_node;
  65         tree long_long_integer_type_node;
  66
  67         tree short_unsigned_type_node;
  68         tree long_unsigned_type_node;
  69         tree long_long_unsigned_type_node;
  70
  71         tree truthvalue_type_node;
  72         tree truthvalue_false_node;
  73         tree truthvalue_true_node;
  74
  75         tree ptrdiff_type_node;
  76
  77         tree unsigned_char_type_node;
  78         tree signed_char_type_node;
  79         tree wchar_type_node;
  80
  81         tree char16_type_node;
  82         tree char32_type_node;
  83
  84         tree float_type_node;
  85         tree double_type_node;
  86         tree long_double_type_node;
  87
  88         tree complex_integer_type_node;
  89         tree complex_float_type_node;
  90         tree complex_double_type_node;
  91         tree complex_long_double_type_node;
  92
  93         tree dfloat32_type_node;
  94         tree dfloat64_type_node;
  95         tree_dfloat128_type_node;
  96
  97         tree intQI_type_node;
  98         tree intHI_type_node;
  99         tree intSI_type_node;
 100         tree intDI_type_node;
 101         tree intTI_type_node;
 102
 103         tree unsigned_intQI_type_node;
 104         tree unsigned_intHI_type_node;
 105         tree unsigned_intSI_type_node;
 106         tree unsigned_intDI_type_node;
 107         tree unsigned_intTI_type_node;
 108
 109         tree widest_integer_literal_type_node;
 110         tree widest_unsigned_literal_type_node;
 111
 112    Nodes for types `void *' and `const void *'.
 113
 114         tree ptr_type_node, const_ptr_type_node;
 115
 116    Nodes for types `char *' and `const char *'.
 117
 118         tree string_type_node, const_string_type_node;
 119
 120    Type `char[SOMENUMBER]'.
 121    Used when an array of char is needed and the size is irrelevant.
 122
 123         tree char_array_type_node;
 124
 125    Type `int[SOMENUMBER]' or something like it.
 126    Used when an array of int needed and the size is irrelevant.
 127
 128         tree int_array_type_node;
 129
 130    Type `wchar_t[SOMENUMBER]' or something like it.
 131    Used when a wide string literal is created.
 132
 133         tree wchar_array_type_node;
 134
 135    Type `char16_t[SOMENUMBER]' or something like it.
 136    Used when a UTF-16 string literal is created.
 137
 138         tree char16_array_type_node;
 139
 140    Type `char32_t[SOMENUMBER]' or something like it.
 141    Used when a UTF-32 string literal is created.
 142
 143         tree char32_array_type_node;
 144
 145    Type `int ()' -- used for implicit declaration of functions.
 146
 147         tree default_function_type;
 148
 149    A VOID_TYPE node, packaged in a TREE_LIST.
 150
 151         tree void_list_node;
 152
 153   The lazily created VAR_DECLs for __FUNCTION__, __PRETTY_FUNCTION__,
 154   and __func__. (C doesn't generate __FUNCTION__ and__PRETTY_FUNCTION__
 155   VAR_DECLS, but C++ does.)
 156
 157         tree function_name_decl_node;
 158         tree pretty_function_name_decl_node;
 159         tree c99_function_name_decl_node;
 160
 161   Stack of nested function name VAR_DECLs.
 162
 163         tree saved_function_name_decls;
 164
 165 */
 166
 167 tree c_global_trees[CTI_MAX];
 168 \f
 169 /* Switches common to the C front ends.  */
 170
 171 /* Nonzero if preprocessing only.  */
 172
 173 int flag_preprocess_only;
 174
 175 /* Nonzero means don't output line number information.  */
 176
 177 char flag_no_line_commands;
 178
 179 /* Nonzero causes -E output not to be done, but directives such as
 180    #define that have side effects are still obeyed.  */
 181
 182 char flag_no_output;
 183
 184 /* Nonzero means dump macros in some fashion.  */
 185
 186 char flag_dump_macros;
 187
 188 /* Nonzero means pass #include lines through to the output.  */
 189
 190 char flag_dump_includes;
 191
 192 /* Nonzero means process PCH files while preprocessing.  */
 193
 194 bool flag_pch_preprocess;
 195
 196 /* The file name to which we should write a precompiled header, or
 197    NULL if no header will be written in this compile.  */
 198
 199 const char *pch_file;
 200
 201 /* Nonzero if an ISO standard was selected.  It rejects macros in the
 202    user's namespace.  */
 203 int flag_iso;
 204
 205 /* Nonzero if -undef was given.  It suppresses target built-in macros
 206    and assertions.  */
 207 int flag_undef;
 208
 209 /* Nonzero means don't recognize the non-ANSI builtin functions.  */
 210
 211 int flag_no_builtin;
 212
 213 /* Nonzero means don't recognize the non-ANSI builtin functions.
 214    -ansi sets this.  */
 215
 216 int flag_no_nonansi_builtin;
 217
 218 /* Nonzero means give `double' the same size as `float'.  */
 219
 220 int flag_short_double;
 221
 222 /* Nonzero means give `wchar_t' the same size as `short'.  */
 223
 224 int flag_short_wchar;
 225
 226 /* Nonzero means allow implicit conversions between vectors with
 227    differing numbers of subparts and/or differing element types.  */
 228 int flag_lax_vector_conversions;
 229
 230 /* Nonzero means allow Microsoft extensions without warnings or errors.  */
 231 int flag_ms_extensions;
 232
 233 /* Nonzero means don't recognize the keyword `asm'.  */
 234
 235 int flag_no_asm;
 236
 237 /* Nonzero means to treat bitfields as signed unless they say `unsigned'.  */
 238
 239 int flag_signed_bitfields = 1;
 240
 241 /* Warn about #pragma directives that are not recognized.  */
 242
 243 int warn_unknown_pragmas; /* Tri state variable.  */
 244
 245 /* Warn about format/argument anomalies in calls to formatted I/O functions
 246    (*printf, *scanf, strftime, strfmon, etc.).  */
 247
 248 int warn_format;
 249
 250 /* Warn about using __null (as NULL in C++) as sentinel.  For code compiled
 251    with GCC this doesn't matter as __null is guaranteed to have the right
 252    size.  */
 253
 254 int warn_strict_null_sentinel;
 255
 256 /* Zero means that faster, ...NonNil variants of objc_msgSend...
 257    calls will be used in ObjC; passing nil receivers to such calls
 258    will most likely result in crashes.  */
 259 int flag_nil_receivers = 1;
 260
 261 /* Nonzero means that code generation will be altered to support
 262    "zero-link" execution.  This currently affects ObjC only, but may
 263    affect other languages in the future.  */
 264 int flag_zero_link = 0;
 265
 266 /* Nonzero means emit an '__OBJC, __image_info' for the current translation
 267    unit.  It will inform the ObjC runtime that class definition(s) herein
 268    contained are to replace one(s) previously loaded.  */
 269 int flag_replace_objc_classes = 0;
 270
 271 /* C/ObjC language option variables.  */
 272
 273
 274 /* Nonzero means allow type mismatches in conditional expressions;
 275    just make their values `void'.  */
 276
 277 int flag_cond_mismatch;
 278
 279 /* Nonzero means enable C89 Amendment 1 features.  */
 280
 281 int flag_isoc94;
 282
 283 /* Nonzero means use the ISO C99 dialect of C.  */
 284
 285 int flag_isoc99;
 286
 287 /* Nonzero means that we have builtin functions, and main is an int.  */
 288
 289 int flag_hosted = 1;
 290
 291
 292 /* ObjC language option variables.  */
 293
 294
 295 /* Open and close the file for outputting class declarations, if
 296    requested (ObjC).  */
 297
 298 int flag_gen_declaration;
 299
 300 /* Tells the compiler that this is a special run.  Do not perform any
 301    compiling, instead we are to test some platform dependent features
 302    and output a C header file with appropriate definitions.  */
 303
 304 int print_struct_values;
 305
 306 /* Tells the compiler what is the constant string class for ObjC.  */
 307
 308 const char *constant_string_class_name;
 309
 310
 311 /* C++ language option variables.  */
 312
 313
 314 /* Nonzero means don't recognize any extension keywords.  */
 315
 316 int flag_no_gnu_keywords;
 317
 318 /* Nonzero means do emit exported implementations of functions even if
 319    they can be inlined.  */
 320
 321 int flag_implement_inlines = 1;
 322
 323 /* Nonzero means that implicit instantiations will be emitted if needed.  */
 324
 325 int flag_implicit_templates = 1;
 326
 327 /* Nonzero means that implicit instantiations of inline templates will be
 328    emitted if needed, even if instantiations of non-inline templates
 329    aren't.  */
 330
 331 int flag_implicit_inline_templates = 1;
 332
 333 /* Nonzero means generate separate instantiation control files and
 334    juggle them at link time.  */
 335
 336 int flag_use_repository;
 337
 338 /* Nonzero if we want to issue diagnostics that the standard says are not
 339    required.  */
 340
 341 int flag_optional_diags = 1;
 342
 343 /* Nonzero means we should attempt to elide constructors when possible.  */
 344
 345 int flag_elide_constructors = 1;
 346
 347 /* Nonzero means that member functions defined in class scope are
 348    inline by default.  */
 349
 350 int flag_default_inline = 1;
 351
 352 /* Controls whether compiler generates 'type descriptor' that give
 353    run-time type information.  */
 354
 355 int flag_rtti = 1;
 356
 357 /* Nonzero if we want to conserve space in the .o files.  We do this
 358    by putting uninitialized data and runtime initialized data into
 359    .common instead of .data at the expense of not flagging multiple
 360    definitions.  */
 361
 362 int flag_conserve_space;
 363
 364 /* Nonzero if we want to obey access control semantics.  */
 365
 366 int flag_access_control = 1;
 367
 368 /* Nonzero if we want to check the return value of new and avoid calling
 369    constructors if it is a null pointer.  */
 370
 371 int flag_check_new;
 372
 373 /* The C++ dialect being used. C++98 is the default.  */
 374
 375 enum cxx_dialect cxx_dialect = cxx98;
 376
 377 /* Nonzero if we want the new ISO rules for pushing a new scope for `for'
 378    initialization variables.
 379    0: Old rules, set by -fno-for-scope.
 380    2: New ISO rules, set by -ffor-scope.
 381    1: Try to implement new ISO rules, but with backup compatibility
 382    (and warnings).  This is the default, for now.  */
 383
 384 int flag_new_for_scope = 1;
 385
 386 /* Nonzero if we want to emit defined symbols with common-like linkage as
 387    weak symbols where possible, in order to conform to C++ semantics.
 388    Otherwise, emit them as local symbols.  */
 389
 390 int flag_weak = 1;
 391
 392 /* 0 means we want the preprocessor to not emit line directives for
 393    the current working directory.  1 means we want it to do it.  -1
 394    means we should decide depending on whether debugging information
 395    is being emitted or not.  */
 396
 397 int flag_working_directory = -1;
 398
 399 /* Nonzero to use __cxa_atexit, rather than atexit, to register
 400    destructors for local statics and global objects.  '2' means it has been
 401    set nonzero as a default, not by a command-line flag.  */
 402
 403 int flag_use_cxa_atexit = DEFAULT_USE_CXA_ATEXIT;
 404
 405 /* Nonzero to use __cxa_get_exception_ptr in C++ exception-handling
 406    code.  '2' means it has not been set explicitly on the command line.  */
 407
 408 int flag_use_cxa_get_exception_ptr = 2;
 409
 410 /* Nonzero means to implement standard semantics for exception
 411    specifications, calling unexpected if an exception is thrown that
 412    doesn't match the specification.  Zero means to treat them as
 413    assertions and optimize accordingly, but not check them.  */
 414
 415 int flag_enforce_eh_specs = 1;
 416
 417 /* Nonzero means to generate thread-safe code for initializing local
 418    statics.  */
 419
 420 int flag_threadsafe_statics = 1;
 421
 422 /* Nonzero if we want to pretty-print template specializations as the
 423    template signature followed by the arguments.  */
 424
 425 int flag_pretty_templates = 1;
 426
 427 /* Nonzero means warn about implicit declarations.  */
 428
 429 int warn_implicit = 1;
 430
 431 /* Maximum template instantiation depth.  This limit is rather
 432    arbitrary, but it exists to limit the time it takes to notice
 433    infinite template instantiations.  */
 434
 435 int max_tinst_depth = 500;
 436
 437
 438
 439 /* The elements of `ridpointers' are identifier nodes for the reserved
 440    type names and storage classes.  It is indexed by a RID_... value.  */
 441 tree *ridpointers;
 442
 443 tree (*make_fname_decl) (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_always_inline_attribute (tree *, tree, tree, int,
 486                                             bool *);
 487 static tree handle_gnu_inline_attribute (tree *, tree, tree, int, bool *);
 488 static tree handle_artificial_attribute (tree *, tree, tree, int, bool *);
 489 static tree handle_flatten_attribute (tree *, tree, tree, int, bool *);
 490 static tree handle_error_attribute (tree *, tree, tree, int, bool *);
 491 static tree handle_used_attribute (tree *, tree, tree, int, bool *);
 492 static tree handle_unused_attribute (tree *, tree, tree, int, bool *);
 493 static tree handle_externally_visible_attribute (tree *, tree, tree, int,
 494                                                  bool *);
 495 static tree handle_const_attribute (tree *, tree, tree, int, bool *);
 496 static tree handle_transparent_union_attribute (tree *, tree, tree,
 497                                                 int, bool *);
 498 static tree handle_constructor_attribute (tree *, tree, tree, int, bool *);
 499 static tree handle_destructor_attribute (tree *, tree, tree, int, bool *);
 500 static tree handle_mode_attribute (tree *, tree, tree, int, bool *);
 501 static tree handle_section_attribute (tree *, tree, tree, int, bool *);
 502 static tree handle_aligned_attribute (tree *, tree, tree, int, bool *);
 503 static tree handle_weak_attribute (tree *, tree, tree, int, bool *) ;
 504 static tree handle_alias_attribute (tree *, tree, tree, int, bool *);
 505 static tree handle_weakref_attribute (tree *, tree, tree, int, bool *) ;
 506 static tree handle_visibility_attribute (tree *, tree, tree, int,
 507                                          bool *);
 508 static tree handle_tls_model_attribute (tree *, tree, tree, int,
 509                                         bool *);
 510 static tree handle_no_instrument_function_attribute (tree *, tree,
 511                                                      tree, int, bool *);
 512 static tree handle_malloc_attribute (tree *, tree, tree, int, bool *);
 513 static tree handle_returns_twice_attribute (tree *, tree, tree, int, bool *);
 514 static tree handle_no_limit_stack_attribute (tree *, tree, tree, int,
 515                                              bool *);
 516 static tree handle_pure_attribute (tree *, tree, tree, int, bool *);
 517 static tree handle_novops_attribute (tree *, tree, tree, int, bool *);
 518 static tree handle_deprecated_attribute (tree *, tree, tree, int,
 519                                          bool *);
 520 static tree handle_vector_size_attribute (tree *, tree, tree, int,
 521                                           bool *);
 522 static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *);
 523 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
 524 static tree handle_cleanup_attribute (tree *, tree, tree, int, bool *);
 525 static tree handle_warn_unused_result_attribute (tree *, tree, tree, int,
 526                                                  bool *);
 527 static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *);
 528 static tree handle_type_generic_attribute (tree *, tree, tree, int, bool *);
 529 static tree handle_alloc_size_attribute (tree *, tree, tree, int, bool *);
 530 static tree handle_target_attribute (tree *, tree, tree, int, bool *);
 531 static tree handle_optimize_attribute (tree *, tree, tree, int, bool *);
 532
 533 static void check_function_nonnull (tree, int, tree *);
 534 static void check_nonnull_arg (void *, tree, unsigned HOST_WIDE_INT);
 535 static bool nonnull_check_p (tree, unsigned HOST_WIDE_INT);
 536 static bool get_nonnull_operand (tree, unsigned HOST_WIDE_INT *);
 537 static int resort_field_decl_cmp (const void *, const void *);
 538
 539 /* Reserved words.  The third field is a mask: keywords are disabled
 540    if they match the mask.
 541
 542    Masks for languages:
 543    C --std=c89: D_C99 | D_CXXONLY | D_OBJC | D_CXX_OBJC
 544    C --std=c99: D_CXXONLY | D_OBJC
 545    ObjC is like C except that D_OBJC and D_CXX_OBJC are not set
 546    C++ --std=c98: D_CONLY | D_CXXOX | D_OBJC
 547    C++ --std=c0x: D_CONLY | D_OBJC
 548    ObjC++ is like C++ except that D_OBJC is not set
 549
 550    If -fno-asm is used, D_ASM is added to the mask.  If
 551    -fno-gnu-keywords is used, D_EXT is added.  If -fno-asm and C in
 552    C89 mode, D_EXT89 is added for both -fno-asm and -fno-gnu-keywords.
 553    In C with -Wc++-compat, we warn if D_CXXWARN is set.  */
 554
 555 const struct c_common_resword c_common_reswords[] =
 556 {
 557   { "_Bool",            RID_BOOL,      D_CONLY },
 558   { "_Complex",         RID_COMPLEX,    0 },
 559   { "_Imaginary",       RID_IMAGINARY, D_CONLY },
 560   { "_Decimal32",       RID_DFLOAT32,  D_CONLY | D_EXT },
 561   { "_Decimal64",       RID_DFLOAT64,  D_CONLY | D_EXT },
 562   { "_Decimal128",      RID_DFLOAT128, D_CONLY | D_EXT },
 563   { "_Fract",           RID_FRACT,     D_CONLY | D_EXT },
 564   { "_Accum",           RID_ACCUM,     D_CONLY | D_EXT },
 565   { "_Sat",             RID_SAT,       D_CONLY | D_EXT },
 566   { "__FUNCTION__",     RID_FUNCTION_NAME, 0 },
 567   { "__PRETTY_FUNCTION__", RID_PRETTY_FUNCTION_NAME, 0 },
 568   { "__alignof",        RID_ALIGNOF,    0 },
 569   { "__alignof__",      RID_ALIGNOF,    0 },
 570   { "__asm",            RID_ASM,        0 },
 571   { "__asm__",          RID_ASM,        0 },
 572   { "__attribute",      RID_ATTRIBUTE,  0 },
 573   { "__attribute__",    RID_ATTRIBUTE,  0 },
 574   { "__builtin_choose_expr", RID_CHOOSE_EXPR, D_CONLY },
 575   { "__builtin_offsetof", RID_OFFSETOF, 0 },
 576   { "__builtin_types_compatible_p", RID_TYPES_COMPATIBLE_P, D_CONLY },
 577   { "__builtin_va_arg", RID_VA_ARG,     0 },
 578   { "__complex",        RID_COMPLEX,    0 },
 579   { "__complex__",      RID_COMPLEX,    0 },
 580   { "__const",          RID_CONST,      0 },
 581   { "__const__",        RID_CONST,      0 },
 582   { "__decltype",       RID_DECLTYPE,   D_CXXONLY },
 583   { "__extension__",    RID_EXTENSION,  0 },
 584   { "__func__",         RID_C99_FUNCTION_NAME, 0 },
 585   { "__has_nothrow_assign", RID_HAS_NOTHROW_ASSIGN, D_CXXONLY },
 586   { "__has_nothrow_constructor", RID_HAS_NOTHROW_CONSTRUCTOR, D_CXXONLY },
 587   { "__has_nothrow_copy", RID_HAS_NOTHROW_COPY, D_CXXONLY },
 588   { "__has_trivial_assign", RID_HAS_TRIVIAL_ASSIGN, D_CXXONLY },
 589   { "__has_trivial_constructor", RID_HAS_TRIVIAL_CONSTRUCTOR, D_CXXONLY },
 590   { "__has_trivial_copy", RID_HAS_TRIVIAL_COPY, D_CXXONLY },
 591   { "__has_trivial_destructor", RID_HAS_TRIVIAL_DESTRUCTOR, D_CXXONLY },
 592   { "__has_virtual_destructor", RID_HAS_VIRTUAL_DESTRUCTOR, D_CXXONLY },
 593   { "__is_abstract",    RID_IS_ABSTRACT, D_CXXONLY },
 594   { "__is_base_of",     RID_IS_BASE_OF, D_CXXONLY },
 595   { "__is_class",       RID_IS_CLASS,   D_CXXONLY },
 596   { "__is_convertible_to", RID_IS_CONVERTIBLE_TO, D_CXXONLY },
 597   { "__is_empty",       RID_IS_EMPTY,   D_CXXONLY },
 598   { "__is_enum",        RID_IS_ENUM,    D_CXXONLY },
 599   { "__is_pod",         RID_IS_POD,     D_CXXONLY },
 600   { "__is_polymorphic", RID_IS_POLYMORPHIC, D_CXXONLY },
 601   { "__is_union",       RID_IS_UNION,   D_CXXONLY },
 602   { "__imag",           RID_IMAGPART,   0 },
 603   { "__imag__",         RID_IMAGPART,   0 },
 604   { "__inline",         RID_INLINE,     0 },
 605   { "__inline__",       RID_INLINE,     0 },
 606   { "__label__",        RID_LABEL,      0 },
 607   { "__null",           RID_NULL,       0 },
 608   { "__real",           RID_REALPART,   0 },
 609   { "__real__",         RID_REALPART,   0 },
 610   { "__restrict",       RID_RESTRICT,   0 },
 611   { "__restrict__",     RID_RESTRICT,   0 },
 612   { "__signed",         RID_SIGNED,     0 },
 613   { "__signed__",       RID_SIGNED,     0 },
 614   { "__thread",         RID_THREAD,     0 },
 615   { "__typeof",         RID_TYPEOF,     0 },
 616   { "__typeof__",       RID_TYPEOF,     0 },
 617   { "__volatile",       RID_VOLATILE,   0 },
 618   { "__volatile__",     RID_VOLATILE,   0 },
 619   { "asm",              RID_ASM,        D_ASM },
 620   { "auto",             RID_AUTO,       0 },
 621   { "bool",             RID_BOOL,       D_CXXONLY | D_CXXWARN },
 622   { "break",            RID_BREAK,      0 },
 623   { "case",             RID_CASE,       0 },
 624   { "catch",            RID_CATCH,      D_CXX_OBJC | D_CXXWARN },
 625   { "char",             RID_CHAR,       0 },
 626   { "char16_t",         RID_CHAR16,     D_CXXONLY | D_CXX0X | D_CXXWARN },
 627   { "char32_t",         RID_CHAR32,     D_CXXONLY | D_CXX0X | D_CXXWARN },
 628   { "class",            RID_CLASS,      D_CXX_OBJC | D_CXXWARN },
 629   { "const",            RID_CONST,      0 },
 630   { "const_cast",       RID_CONSTCAST,  D_CXXONLY | D_CXXWARN },
 631   { "continue",         RID_CONTINUE,   0 },
 632   { "decltype",         RID_DECLTYPE,   D_CXXONLY | D_CXX0X | D_CXXWARN },
 633   { "default",          RID_DEFAULT,    0 },
 634   { "delete",           RID_DELETE,     D_CXXONLY | D_CXXWARN },
 635   { "do",               RID_DO,         0 },
 636   { "double",           RID_DOUBLE,     0 },
 637   { "dynamic_cast",     RID_DYNCAST,    D_CXXONLY | D_CXXWARN },
 638   { "else",             RID_ELSE,       0 },
 639   { "enum",             RID_ENUM,       0 },
 640   { "explicit",         RID_EXPLICIT,   D_CXXONLY | D_CXXWARN },
 641   { "export",           RID_EXPORT,     D_CXXONLY | D_CXXWARN },
 642   { "extern",           RID_EXTERN,     0 },
 643   { "false",            RID_FALSE,      D_CXXONLY | D_CXXWARN },
 644   { "float",            RID_FLOAT,      0 },
 645   { "for",              RID_FOR,        0 },
 646   { "friend",           RID_FRIEND,     D_CXXONLY | D_CXXWARN },
 647   { "goto",             RID_GOTO,       0 },
 648   { "if",               RID_IF,         0 },
 649   { "inline",           RID_INLINE,     D_EXT89 },
 650   { "int",              RID_INT,        0 },
 651   { "long",             RID_LONG,       0 },
 652   { "mutable",          RID_MUTABLE,    D_CXXONLY | D_CXXWARN },
 653   { "namespace",        RID_NAMESPACE,  D_CXXONLY | D_CXXWARN },
 654   { "new",              RID_NEW,        D_CXXONLY | D_CXXWARN },
 655   { "operator",         RID_OPERATOR,   D_CXXONLY | D_CXXWARN },
 656   { "private",          RID_PRIVATE,    D_CXX_OBJC | D_CXXWARN },
 657   { "protected",        RID_PROTECTED,  D_CXX_OBJC | D_CXXWARN },
 658   { "public",           RID_PUBLIC,     D_CXX_OBJC | D_CXXWARN },
 659   { "register",         RID_REGISTER,   0 },
 660   { "reinterpret_cast", RID_REINTCAST,  D_CXXONLY | D_CXXWARN },
 661   { "restrict",         RID_RESTRICT,   D_CONLY | D_C99 },
 662   { "return",           RID_RETURN,     0 },
 663   { "short",            RID_SHORT,      0 },
 664   { "signed",           RID_SIGNED,     0 },
 665   { "sizeof",           RID_SIZEOF,     0 },
 666   { "static",           RID_STATIC,     0 },
 667   { "static_assert",    RID_STATIC_ASSERT, D_CXXONLY | D_CXX0X | D_CXXWARN },
 668   { "static_cast",      RID_STATCAST,   D_CXXONLY | D_CXXWARN },
 669   { "struct",           RID_STRUCT,     0 },
 670   { "switch",           RID_SWITCH,     0 },
 671   { "template",         RID_TEMPLATE,   D_CXXONLY | D_CXXWARN },
 672   { "this",             RID_THIS,       D_CXXONLY | D_CXXWARN },
 673   { "throw",            RID_THROW,      D_CXX_OBJC | D_CXXWARN },
 674   { "true",             RID_TRUE,       D_CXXONLY | D_CXXWARN },
 675   { "try",              RID_TRY,        D_CXX_OBJC | D_CXXWARN },
 676   { "typedef",          RID_TYPEDEF,    0 },
 677   { "typename",         RID_TYPENAME,   D_CXXONLY | D_CXXWARN },
 678   { "typeid",           RID_TYPEID,     D_CXXONLY | D_CXXWARN },
 679   { "typeof",           RID_TYPEOF,     D_ASM | D_EXT },
 680   { "union",            RID_UNION,      0 },
 681   { "unsigned",         RID_UNSIGNED,   0 },
 682   { "using",            RID_USING,      D_CXXONLY | D_CXXWARN },
 683   { "virtual",          RID_VIRTUAL,    D_CXXONLY | D_CXXWARN },
 684   { "void",             RID_VOID,       0 },
 685   { "volatile",         RID_VOLATILE,   0 },
 686   { "wchar_t",          RID_WCHAR,      D_CXXONLY },
 687   { "while",            RID_WHILE,      0 },
 688   /* These Objective-C keywords are recognized only immediately after
 689      an '@'.  */
 690   { "compatibility_alias", RID_AT_ALIAS,        D_OBJC },
 691   { "defs",             RID_AT_DEFS,            D_OBJC },
 692   { "encode",           RID_AT_ENCODE,          D_OBJC },
 693   { "end",              RID_AT_END,             D_OBJC },
 694   { "implementation",   RID_AT_IMPLEMENTATION,  D_OBJC },
 695   { "interface",        RID_AT_INTERFACE,       D_OBJC },
 696   { "protocol",         RID_AT_PROTOCOL,        D_OBJC },
 697   { "selector",         RID_AT_SELECTOR,        D_OBJC },
 698   { "finally",          RID_AT_FINALLY,         D_OBJC },
 699   { "synchronized",     RID_AT_SYNCHRONIZED,    D_OBJC },
 700   /* These are recognized only in protocol-qualifier context
 701      (see above) */
 702   { "bycopy",           RID_BYCOPY,             D_OBJC },
 703   { "byref",            RID_BYREF,              D_OBJC },
 704   { "in",               RID_IN,                 D_OBJC },
 705   { "inout",            RID_INOUT,              D_OBJC },
 706   { "oneway",           RID_ONEWAY,             D_OBJC },
 707   { "out",              RID_OUT,                D_OBJC },
 708 };
 709
 710 const unsigned int num_c_common_reswords =
 711   sizeof c_common_reswords / sizeof (struct c_common_resword);
 712
 713 /* Table of machine-independent attributes common to all C-like languages.  */
 714 const struct attribute_spec c_common_attribute_table[] =
 715 {
 716   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 717   { "packed",                 0, 0, false, false, false,
 718                               handle_packed_attribute },
 719   { "nocommon",               0, 0, true,  false, false,
 720                               handle_nocommon_attribute },
 721   { "common",                 0, 0, true,  false, false,
 722                               handle_common_attribute },
 723   /* FIXME: logically, noreturn attributes should be listed as
 724      "false, true, true" and apply to function types.  But implementing this
 725      would require all the places in the compiler that use TREE_THIS_VOLATILE
 726      on a decl to identify non-returning functions to be located and fixed
 727      to check the function type instead.  */
 728   { "noreturn",               0, 0, true,  false, false,
 729                               handle_noreturn_attribute },
 730   { "volatile",               0, 0, true,  false, false,
 731                               handle_noreturn_attribute },
 732   { "noinline",               0, 0, true,  false, false,
 733                               handle_noinline_attribute },
 734   { "always_inline",          0, 0, true,  false, false,
 735                               handle_always_inline_attribute },
 736   { "gnu_inline",             0, 0, true,  false, false,
 737                               handle_gnu_inline_attribute },
 738   { "artificial",             0, 0, true,  false, false,
 739                               handle_artificial_attribute },
 740   { "flatten",                0, 0, true,  false, false,
 741                               handle_flatten_attribute },
 742   { "used",                   0, 0, true,  false, false,
 743                               handle_used_attribute },
 744   { "unused",                 0, 0, false, false, false,
 745                               handle_unused_attribute },
 746   { "externally_visible",     0, 0, true,  false, false,
 747                               handle_externally_visible_attribute },
 748   /* The same comments as for noreturn attributes apply to const ones.  */
 749   { "const",                  0, 0, true,  false, false,
 750                               handle_const_attribute },
 751   { "transparent_union",      0, 0, false, false, false,
 752                               handle_transparent_union_attribute },
 753   { "constructor",            0, 1, true,  false, false,
 754                               handle_constructor_attribute },
 755   { "destructor",             0, 1, true,  false, false,
 756                               handle_destructor_attribute },
 757   { "mode",                   1, 1, false,  true, false,
 758                               handle_mode_attribute },
 759   { "section",                1, 1, true,  false, false,
 760                               handle_section_attribute },
 761   { "aligned",                0, 1, false, false, false,
 762                               handle_aligned_attribute },
 763   { "weak",                   0, 0, true,  false, false,
 764                               handle_weak_attribute },
 765   { "alias",                  1, 1, true,  false, false,
 766                               handle_alias_attribute },
 767   { "weakref",                0, 1, true,  false, false,
 768                               handle_weakref_attribute },
 769   { "no_instrument_function", 0, 0, true,  false, false,
 770                               handle_no_instrument_function_attribute },
 771   { "malloc",                 0, 0, true,  false, false,
 772                               handle_malloc_attribute },
 773   { "returns_twice",          0, 0, true,  false, false,
 774                               handle_returns_twice_attribute },
 775   { "no_stack_limit",         0, 0, true,  false, false,
 776                               handle_no_limit_stack_attribute },
 777   { "pure",                   0, 0, true,  false, false,
 778                               handle_pure_attribute },
 779   /* For internal use (marking of builtins) only.  The name contains space
 780      to prevent its usage in source code.  */
 781   { "no vops",                0, 0, true,  false, false,
 782                               handle_novops_attribute },
 783   { "deprecated",             0, 1, false, false, false,
 784                               handle_deprecated_attribute },
 785   { "vector_size",            1, 1, false, true, false,
 786                               handle_vector_size_attribute },
 787   { "visibility",             1, 1, false, false, false,
 788                               handle_visibility_attribute },
 789   { "tls_model",              1, 1, true,  false, false,
 790                               handle_tls_model_attribute },
 791   { "nonnull",                0, -1, false, true, true,
 792                               handle_nonnull_attribute },
 793   { "nothrow",                0, 0, true,  false, false,
 794                               handle_nothrow_attribute },
 795   { "may_alias",              0, 0, false, true, false, NULL },
 796   { "cleanup",                1, 1, true, false, false,
 797                               handle_cleanup_attribute },
 798   { "warn_unused_result",     0, 0, false, true, true,
 799                               handle_warn_unused_result_attribute },
 800   { "sentinel",               0, 1, false, true, true,
 801                               handle_sentinel_attribute },
 802   /* For internal use (marking of builtins) only.  The name contains space
 803      to prevent its usage in source code.  */
 804   { "type generic",           0, 0, false, true, true,
 805                               handle_type_generic_attribute },
 806   { "alloc_size",             1, 2, false, true, true,
 807                               handle_alloc_size_attribute },
 808   { "cold",                   0, 0, true,  false, false,
 809                               handle_cold_attribute },
 810   { "hot",                    0, 0, true,  false, false,
 811                               handle_hot_attribute },
 812   { "warning",                1, 1, true,  false, false,
 813                               handle_error_attribute },
 814   { "error",                  1, 1, true,  false, false,
 815                               handle_error_attribute },
 816   { "target",                 1, -1, true, false, false,
 817                               handle_target_attribute },
 818   { "optimize",               1, -1, true, false, false,
 819                               handle_optimize_attribute },
 820   { NULL,                     0, 0, false, false, false, NULL }
 821 };
 822
 823 /* Give the specifications for the format attributes, used by C and all
 824    descendants.  */
 825
 826 const struct attribute_spec c_common_format_attribute_table[] =
 827 {
 828   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 829   { "format",                 3, 3, false, true,  true,
 830                               handle_format_attribute },
 831   { "format_arg",             1, 1, false, true,  true,
 832                               handle_format_arg_attribute },
 833   { NULL,                     0, 0, false, false, false, NULL }
 834 };
 835
 836 /* Push current bindings for the function name VAR_DECLS.  */
 837
 838 void
 839 start_fname_decls (void)
 840 {
 841   unsigned ix;
 842   tree saved = NULL_TREE;
 843
 844   for (ix = 0; fname_vars[ix].decl; ix++)
 845     {
 846       tree decl = *fname_vars[ix].decl;
 847
 848       if (decl)
 849         {
 850           saved = tree_cons (decl, build_int_cst (NULL_TREE, ix), saved);
 851           *fname_vars[ix].decl = NULL_TREE;
 852         }
 853     }
 854   if (saved || saved_function_name_decls)
 855     /* Normally they'll have been NULL, so only push if we've got a
 856        stack, or they are non-NULL.  */
 857     saved_function_name_decls = tree_cons (saved, NULL_TREE,
 858                                            saved_function_name_decls);
 859 }
 860
 861 /* Finish up the current bindings, adding them into the current function's
 862    statement tree.  This must be done _before_ finish_stmt_tree is called.
 863    If there is no current function, we must be at file scope and no statements
 864    are involved. Pop the previous bindings.  */
 865
 866 void
 867 finish_fname_decls (void)
 868 {
 869   unsigned ix;
 870   tree stmts = NULL_TREE;
 871   tree stack = saved_function_name_decls;
 872
 873   for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack))
 874     append_to_statement_list (TREE_VALUE (stack), &stmts);
 875
 876   if (stmts)
 877     {
 878       tree *bodyp = &DECL_SAVED_TREE (current_function_decl);
 879
 880       if (TREE_CODE (*bodyp) == BIND_EXPR)
 881         bodyp = &BIND_EXPR_BODY (*bodyp);
 882
 883       append_to_statement_list_force (*bodyp, &stmts);
 884       *bodyp = stmts;
 885     }
 886
 887   for (ix = 0; fname_vars[ix].decl; ix++)
 888     *fname_vars[ix].decl = NULL_TREE;
 889
 890   if (stack)
 891     {
 892       /* We had saved values, restore them.  */
 893       tree saved;
 894
 895       for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved))
 896         {
 897           tree decl = TREE_PURPOSE (saved);
 898           unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved));
 899
 900           *fname_vars[ix].decl = decl;
 901         }
 902       stack = TREE_CHAIN (stack);
 903     }
 904   saved_function_name_decls = stack;
 905 }
 906
 907 /* Return the text name of the current function, suitably prettified
 908    by PRETTY_P.  Return string must be freed by caller.  */
 909
 910 const char *
 911 fname_as_string (int pretty_p)
 912 {
 913   const char *name = "top level";
 914   char *namep;
 915   int vrb = 2, len;
 916   cpp_string cstr = { 0, 0 }, strname;
 917
 918   if (!pretty_p)
 919     {
 920       name = "";
 921       vrb = 0;
 922     }
 923
 924   if (current_function_decl)
 925     name = lang_hooks.decl_printable_name (current_function_decl, vrb);
 926
 927   len = strlen (name) + 3; /* Two for '"'s.  One for NULL.  */
 928
 929   namep = XNEWVEC (char, len);
 930   snprintf (namep, len, "\"%s\"", name);
 931   strname.text = (unsigned char *) namep;
 932   strname.len = len - 1;
 933
 934   if (cpp_interpret_string (parse_in, &strname, 1, &cstr, CPP_STRING))
 935     {
 936       XDELETEVEC (namep);
 937       return (const char *) cstr.text;
 938     }
 939
 940   return namep;
 941 }
 942
 943 /* Return the VAR_DECL for a const char array naming the current
 944    function. If the VAR_DECL has not yet been created, create it
 945    now. RID indicates how it should be formatted and IDENTIFIER_NODE
 946    ID is its name (unfortunately C and C++ hold the RID values of
 947    keywords in different places, so we can't derive RID from ID in
 948    this language independent code. LOC is the location of the
 949    function.  */
 950
 951 tree
 952 fname_decl (location_t loc, unsigned int rid, tree id)
 953 {
 954   unsigned ix;
 955   tree decl = NULL_TREE;
 956
 957   for (ix = 0; fname_vars[ix].decl; ix++)
 958     if (fname_vars[ix].rid == rid)
 959       break;
 960
 961   decl = *fname_vars[ix].decl;
 962   if (!decl)
 963     {
 964       /* If a tree is built here, it would normally have the lineno of
 965          the current statement.  Later this tree will be moved to the
 966          beginning of the function and this line number will be wrong.
 967          To avoid this problem set the lineno to 0 here; that prevents
 968          it from appearing in the RTL.  */
 969       tree stmts;
 970       location_t saved_location = input_location;
 971       input_location = UNKNOWN_LOCATION;
 972
 973       stmts = push_stmt_list ();
 974       decl = (*make_fname_decl) (loc, id, fname_vars[ix].pretty);
 975       stmts = pop_stmt_list (stmts);
 976       if (!IS_EMPTY_STMT (stmts))
 977         saved_function_name_decls
 978           = tree_cons (decl, stmts, saved_function_name_decls);
 979       *fname_vars[ix].decl = decl;
 980       input_location = saved_location;
 981     }
 982   if (!ix && !current_function_decl)
 983     pedwarn (loc, 0, "%qD is not defined outside of function scope", decl);
 984
 985   return decl;
 986 }
 987
 988 /* Given a STRING_CST, give it a suitable array-of-chars data type.  */
 989
 990 tree
 991 fix_string_type (tree value)
 992 {
 993   int length = TREE_STRING_LENGTH (value);
 994   int nchars;
 995   tree e_type, i_type, a_type;
 996
 997   /* Compute the number of elements, for the array type.  */
 998   if (TREE_TYPE (value) == char_array_type_node || !TREE_TYPE (value))
 999     {
1000       nchars = length;
1001       e_type = char_type_node;
1002     }
1003   else if (TREE_TYPE (value) == char16_array_type_node)
1004     {
1005       nchars = length / (TYPE_PRECISION (char16_type_node) / BITS_PER_UNIT);
1006       e_type = char16_type_node;
1007     }
1008   else if (TREE_TYPE (value) == char32_array_type_node)
1009     {
1010       nchars = length / (TYPE_PRECISION (char32_type_node) / BITS_PER_UNIT);
1011       e_type = char32_type_node;
1012     }
1013   else
1014     {
1015       nchars = length / (TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT);
1016       e_type = wchar_type_node;
1017     }
1018
1019   /* C89 2.2.4.1, C99 5.2.4.1 (Translation limits).  The analogous
1020      limit in C++98 Annex B is very large (65536) and is not normative,
1021      so we do not diagnose it (warn_overlength_strings is forced off
1022      in c_common_post_options).  */
1023   if (warn_overlength_strings)
1024     {
1025       const int nchars_max = flag_isoc99 ? 4095 : 509;
1026       const int relevant_std = flag_isoc99 ? 99 : 90;
1027       if (nchars - 1 > nchars_max)
1028         /* Translators: The %d after 'ISO C' will be 90 or 99.  Do not
1029            separate the %d from the 'C'.  'ISO' should not be
1030            translated, but it may be moved after 'C%d' in languages
1031            where modifiers follow nouns.  */
1032         pedwarn (input_location, OPT_Woverlength_strings,
1033                  "string length %qd is greater than the length %qd "
1034                  "ISO C%d compilers are required to support",
1035                  nchars - 1, nchars_max, relevant_std);
1036     }
1037
1038   /* Create the array type for the string constant.  The ISO C++
1039      standard says that a string literal has type `const char[N]' or
1040      `const wchar_t[N]'.  We use the same logic when invoked as a C
1041      front-end with -Wwrite-strings.
1042      ??? We should change the type of an expression depending on the
1043      state of a warning flag.  We should just be warning -- see how
1044      this is handled in the C++ front-end for the deprecated implicit
1045      conversion from string literals to `char*' or `wchar_t*'.
1046
1047      The C++ front end relies on TYPE_MAIN_VARIANT of a cv-qualified
1048      array type being the unqualified version of that type.
1049      Therefore, if we are constructing an array of const char, we must
1050      construct the matching unqualified array type first.  The C front
1051      end does not require this, but it does no harm, so we do it
1052      unconditionally.  */
1053   i_type = build_index_type (build_int_cst (NULL_TREE, nchars - 1));
1054   a_type = build_array_type (e_type, i_type);
1055   if (c_dialect_cxx() || warn_write_strings)
1056     a_type = c_build_qualified_type (a_type, TYPE_QUAL_CONST);
1057
1058   TREE_TYPE (value) = a_type;
1059   TREE_CONSTANT (value) = 1;
1060   TREE_READONLY (value) = 1;
1061   TREE_STATIC (value) = 1;
1062   return value;
1063 }
1064 \f
1065 /* Fully fold EXPR, an expression that was not folded (beyond integer
1066    constant expressions and null pointer constants) when being built
1067    up.  If IN_INIT, this is in a static initializer and certain
1068    changes are made to the folding done.  Clear *MAYBE_CONST if
1069    MAYBE_CONST is not NULL and EXPR is definitely not a constant
1070    expression because it contains an evaluated operator (in C99) or an
1071    operator outside of sizeof returning an integer constant (in C90)
1072    not permitted in constant expressions, or because it contains an
1073    evaluated arithmetic overflow.  (*MAYBE_CONST should typically be
1074    set to true by callers before calling this function.)  Return the
1075    folded expression.  Function arguments have already been folded
1076    before calling this function, as have the contents of SAVE_EXPR,
1077    TARGET_EXPR, BIND_EXPR, VA_ARG_EXPR, OBJ_TYPE_REF and
1078    C_MAYBE_CONST_EXPR.  */
1079
1080 tree
1081 c_fully_fold (tree expr, bool in_init, bool *maybe_const)
1082 {
1083   tree ret;
1084   tree eptype = NULL_TREE;
1085   bool dummy = true;
1086   bool maybe_const_itself = true;
1087
1088   /* This function is not relevant to C++ because C++ folds while
1089      parsing, and may need changes to be correct for C++ when C++
1090      stops folding while parsing.  */
1091   if (c_dialect_cxx ())
1092     gcc_unreachable ();
1093
1094   if (!maybe_const)
1095     maybe_const = &dummy;
1096   if (TREE_CODE (expr) == EXCESS_PRECISION_EXPR)
1097     {
1098       eptype = TREE_TYPE (expr);
1099       expr = TREE_OPERAND (expr, 0);
1100     }
1101   ret = c_fully_fold_internal (expr, in_init, maybe_const,
1102                                &maybe_const_itself);
1103   if (eptype)
1104     ret = fold_convert (eptype, ret);
1105   *maybe_const &= maybe_const_itself;
1106   return ret;
1107 }
1108
1109 /* Internal helper for c_fully_fold.  EXPR and IN_INIT are as for
1110    c_fully_fold.  *MAYBE_CONST_OPERANDS is cleared because of operands
1111    not permitted, while *MAYBE_CONST_ITSELF is cleared because of
1112    arithmetic overflow (for C90, *MAYBE_CONST_OPERANDS is carried from
1113    both evaluated and unevaluated subexpressions while
1114    *MAYBE_CONST_ITSELF is carried from only evaluated
1115    subexpressions).  */
1116
1117 static tree
1118 c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands,
1119                        bool *maybe_const_itself)
1120 {
1121   tree ret = expr;
1122   enum tree_code code = TREE_CODE (expr);
1123   enum tree_code_class kind = TREE_CODE_CLASS (code);
1124   location_t loc = EXPR_LOCATION (expr);
1125   tree op0, op1, op2, op3;
1126   tree orig_op0, orig_op1, orig_op2;
1127   bool op0_const = true, op1_const = true, op2_const = true;
1128   bool op0_const_self = true, op1_const_self = true, op2_const_self = true;
1129   bool nowarning = TREE_NO_WARNING (expr);
1130
1131   /* This function is not relevant to C++ because C++ folds while
1132      parsing, and may need changes to be correct for C++ when C++
1133      stops folding while parsing.  */
1134   if (c_dialect_cxx ())
1135     gcc_unreachable ();
1136
1137   /* Constants, declarations, statements, errors, SAVE_EXPRs and
1138      anything else not counted as an expression cannot usefully be
1139      folded further at this point.  */
1140   if (!IS_EXPR_CODE_CLASS (kind)
1141       || kind == tcc_statement
1142       || code == SAVE_EXPR)
1143     return expr;
1144
1145   /* Operands of variable-length expressions (function calls) have
1146      already been folded, as have __builtin_* function calls, and such
1147      expressions cannot occur in constant expressions.  */
1148   if (kind == tcc_vl_exp)
1149     {
1150       *maybe_const_operands = false;
1151       ret = fold (expr);
1152       goto out;
1153     }
1154
1155   if (code == C_MAYBE_CONST_EXPR)
1156     {
1157       tree pre = C_MAYBE_CONST_EXPR_PRE (expr);
1158       tree inner = C_MAYBE_CONST_EXPR_EXPR (expr);
1159       if (C_MAYBE_CONST_EXPR_NON_CONST (expr))
1160         *maybe_const_operands = false;
1161       if (C_MAYBE_CONST_EXPR_INT_OPERANDS (expr))
1162         *maybe_const_itself = false;
1163       if (pre && !in_init)
1164         ret = build2 (COMPOUND_EXPR, TREE_TYPE (expr), pre, inner);
1165       else
1166         ret = inner;
1167       goto out;
1168     }
1169
1170   /* Assignment, increment, decrement, function call and comma
1171      operators, and statement expressions, cannot occur in constant
1172      expressions if evaluated / outside of sizeof.  (Function calls
1173      were handled above, though VA_ARG_EXPR is treated like a function
1174      call here, and statement expressions are handled through
1175      C_MAYBE_CONST_EXPR to avoid folding inside them.)  */
1176   switch (code)
1177     {
1178     case MODIFY_EXPR:
1179     case PREDECREMENT_EXPR:
1180     case PREINCREMENT_EXPR:
1181     case POSTDECREMENT_EXPR:
1182     case POSTINCREMENT_EXPR:
1183     case COMPOUND_EXPR:
1184       *maybe_const_operands = false;
1185       break;
1186
1187     case VA_ARG_EXPR:
1188     case TARGET_EXPR:
1189     case BIND_EXPR:
1190     case OBJ_TYPE_REF:
1191       *maybe_const_operands = false;
1192       ret = fold (expr);
1193       goto out;
1194
1195     default:
1196       break;
1197     }
1198
1199   /* Fold individual tree codes as appropriate.  */
1200   switch (code)
1201     {
1202     case COMPOUND_LITERAL_EXPR:
1203       /* Any non-constancy will have been marked in a containing
1204          C_MAYBE_CONST_EXPR; there is no more folding to do here.  */
1205       goto out;
1206
1207     case COMPONENT_REF:
1208       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1209       op1 = TREE_OPERAND (expr, 1);
1210       op2 = TREE_OPERAND (expr, 2);
1211       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1212                                    maybe_const_itself);
1213       if (op0 != orig_op0)
1214         ret = build3 (COMPONENT_REF, TREE_TYPE (expr), op0, op1, op2);
1215       if (ret != expr)
1216         {
1217           TREE_READONLY (ret) = TREE_READONLY (expr);
1218           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1219         }
1220       goto out;
1221
1222     case ARRAY_REF:
1223       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1224       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1225       op2 = TREE_OPERAND (expr, 2);
1226       op3 = TREE_OPERAND (expr, 3);
1227       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1228                                    maybe_const_itself);
1229       op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
1230                                    maybe_const_itself);
1231       op1 = decl_constant_value_for_optimization (op1);
1232       if (op0 != orig_op0 || op1 != orig_op1)
1233         ret = build4 (ARRAY_REF, TREE_TYPE (expr), op0, op1, op2, op3);
1234       if (ret != expr)
1235         {
1236           TREE_READONLY (ret) = TREE_READONLY (expr);
1237           TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (expr);
1238           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1239         }
1240       ret = fold (ret);
1241       goto out;
1242
1243     case COMPOUND_EXPR:
1244     case MODIFY_EXPR:
1245     case PREDECREMENT_EXPR:
1246     case PREINCREMENT_EXPR:
1247     case POSTDECREMENT_EXPR:
1248     case POSTINCREMENT_EXPR:
1249     case PLUS_EXPR:
1250     case MINUS_EXPR:
1251     case MULT_EXPR:
1252     case POINTER_PLUS_EXPR:
1253     case TRUNC_DIV_EXPR:
1254     case CEIL_DIV_EXPR:
1255     case FLOOR_DIV_EXPR:
1256     case TRUNC_MOD_EXPR:
1257     case RDIV_EXPR:
1258     case EXACT_DIV_EXPR:
1259     case LSHIFT_EXPR:
1260     case RSHIFT_EXPR:
1261     case BIT_IOR_EXPR:
1262     case BIT_XOR_EXPR:
1263     case BIT_AND_EXPR:
1264     case LT_EXPR:
1265     case LE_EXPR:
1266     case GT_EXPR:
1267     case GE_EXPR:
1268     case EQ_EXPR:
1269     case NE_EXPR:
1270     case COMPLEX_EXPR:
1271     case TRUTH_AND_EXPR:
1272     case TRUTH_OR_EXPR:
1273     case TRUTH_XOR_EXPR:
1274     case UNORDERED_EXPR:
1275     case ORDERED_EXPR:
1276     case UNLT_EXPR:
1277     case UNLE_EXPR:
1278     case UNGT_EXPR:
1279     case UNGE_EXPR:
1280     case UNEQ_EXPR:
1281       /* Binary operations evaluating both arguments (increment and
1282          decrement are binary internally in GCC).  */
1283       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1284       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1285       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1286                                    maybe_const_itself);
1287       if (code != MODIFY_EXPR
1288           && code != PREDECREMENT_EXPR
1289           && code != PREINCREMENT_EXPR
1290           && code != POSTDECREMENT_EXPR
1291           && code != POSTINCREMENT_EXPR)
1292         op0 = decl_constant_value_for_optimization (op0);
1293       /* The RHS of a MODIFY_EXPR was fully folded when building that
1294          expression for the sake of conversion warnings.  */
1295       if (code != MODIFY_EXPR)
1296         op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
1297                                      maybe_const_itself);
1298       op1 = decl_constant_value_for_optimization (op1);
1299       if (op0 != orig_op0 || op1 != orig_op1 || in_init)
1300         ret = in_init
1301           ? fold_build2_initializer (code, TREE_TYPE (expr), op0, op1)
1302           : fold_build2 (code, TREE_TYPE (expr), op0, op1);
1303       else
1304         ret = fold (expr);
1305       goto out;
1306
1307     case INDIRECT_REF:
1308     case FIX_TRUNC_EXPR:
1309     case FLOAT_EXPR:
1310     CASE_CONVERT:
1311     case NON_LVALUE_EXPR:
1312     case NEGATE_EXPR:
1313     case BIT_NOT_EXPR:
1314     case TRUTH_NOT_EXPR:
1315     case ADDR_EXPR:
1316     case CONJ_EXPR:
1317     case REALPART_EXPR:
1318     case IMAGPART_EXPR:
1319       /* Unary operations.  */
1320       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1321       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1322                                    maybe_const_itself);
1323       if (code != ADDR_EXPR && code != REALPART_EXPR && code != IMAGPART_EXPR)
1324         op0 = decl_constant_value_for_optimization (op0);
1325       if (op0 != orig_op0 || in_init)
1326         ret = in_init
1327           ? fold_build1_initializer (code, TREE_TYPE (expr), op0)
1328           : fold_build1 (code, TREE_TYPE (expr), op0);
1329       else
1330         ret = fold (expr);
1331       if (code == INDIRECT_REF
1332           && ret != expr
1333           && TREE_CODE (ret) == INDIRECT_REF)
1334         {
1335           TREE_READONLY (ret) = TREE_READONLY (expr);
1336           TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (expr);
1337           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1338         }
1339       goto out;
1340
1341     case TRUTH_ANDIF_EXPR:
1342     case TRUTH_ORIF_EXPR:
1343       /* Binary operations not necessarily evaluating both
1344          arguments.  */
1345       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1346       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1347       op0 = c_fully_fold_internal (op0, in_init, &op0_const, &op0_const_self);
1348       op1 = c_fully_fold_internal (op1, in_init, &op1_const, &op1_const_self);
1349       if (op0 != orig_op0 || op1 != orig_op1 || in_init)
1350         ret = in_init
1351           ? fold_build2_initializer (code, TREE_TYPE (expr), op0, op1)
1352           : fold_build2 (code, TREE_TYPE (expr), op0, op1);
1353       else
1354         ret = fold (expr);
1355       *maybe_const_operands &= op0_const;
1356       *maybe_const_itself &= op0_const_self;
1357       if (!(flag_isoc99
1358             && op0_const
1359             && op0_const_self
1360             && (code == TRUTH_ANDIF_EXPR
1361                 ? op0 == truthvalue_false_node
1362                 : op0 == truthvalue_true_node)))
1363         *maybe_const_operands &= op1_const;
1364       if (!(op0_const
1365             && op0_const_self
1366             && (code == TRUTH_ANDIF_EXPR
1367                 ? op0 == truthvalue_false_node
1368                 : op0 == truthvalue_true_node)))
1369         *maybe_const_itself &= op1_const_self;
1370       goto out;
1371
1372     case COND_EXPR:
1373       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1374       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1375       orig_op2 = op2 = TREE_OPERAND (expr, 2);
1376       op0 = c_fully_fold_internal (op0, in_init, &op0_const, &op0_const_self);
1377       op1 = c_fully_fold_internal (op1, in_init, &op1_const, &op1_const_self);
1378       op2 = c_fully_fold_internal (op2, in_init, &op2_const, &op2_const_self);
1379       if (op0 != orig_op0 || op1 != orig_op1 || op2 != orig_op2)
1380         ret = fold_build3 (code, TREE_TYPE (expr), op0, op1, op2);
1381       else
1382         ret = fold (expr);
1383       *maybe_const_operands &= op0_const;
1384       *maybe_const_itself &= op0_const_self;
1385       if (!(flag_isoc99
1386             && op0_const
1387             && op0_const_self
1388             && op0 == truthvalue_false_node))
1389         *maybe_const_operands &= op1_const;
1390       if (!(op0_const
1391             && op0_const_self
1392             && op0 == truthvalue_false_node))
1393         *maybe_const_itself &= op1_const_self;
1394       if (!(flag_isoc99
1395             && op0_const
1396             && op0_const_self
1397             && op0 == truthvalue_true_node))
1398         *maybe_const_operands &= op2_const;
1399       if (!(op0_const
1400             && op0_const_self
1401             && op0 == truthvalue_true_node))
1402         *maybe_const_itself &= op2_const_self;
1403       goto out;
1404
1405     case EXCESS_PRECISION_EXPR:
1406       /* Each case where an operand with excess precision may be
1407          encountered must remove the EXCESS_PRECISION_EXPR around
1408          inner operands and possibly put one around the whole
1409          expression or possibly convert to the semantic type (which
1410          c_fully_fold does); we cannot tell at this stage which is
1411          appropriate in any particular case.  */
1412       gcc_unreachable ();
1413
1414     default:
1415       /* Various codes may appear through folding built-in functions
1416          and their arguments.  */
1417       goto out;
1418     }
1419
1420  out:
1421   /* Some folding may introduce NON_LVALUE_EXPRs; all lvalue checks
1422      have been done by this point, so remove them again.  */
1423   nowarning |= TREE_NO_WARNING (ret);
1424   STRIP_TYPE_NOPS (ret);
1425   if (nowarning && !TREE_NO_WARNING (ret))
1426     {
1427       if (!CAN_HAVE_LOCATION_P (ret))
1428         ret = build1 (NOP_EXPR, TREE_TYPE (ret), ret);
1429       TREE_NO_WARNING (ret) = 1;
1430     }
1431   if (ret != expr)
1432     protected_set_expr_location (ret, loc);
1433   return ret;
1434 }
1435
1436 /* If not optimizing, EXP is not a VAR_DECL, or EXP has array type,
1437    return EXP.  Otherwise, return either EXP or its known constant
1438    value (if it has one), but return EXP if EXP has mode BLKmode.  ???
1439    Is the BLKmode test appropriate?  */
1440
1441 tree
1442 decl_constant_value_for_optimization (tree exp)
1443 {
1444   tree ret;
1445
1446   /* This function is only used by C, for c_fully_fold and other
1447      optimization, and may not be correct for C++.  */
1448   if (c_dialect_cxx ())
1449     gcc_unreachable ();
1450
1451   if (!optimize
1452       || TREE_CODE (exp) != VAR_DECL
1453       || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
1454       || DECL_MODE (exp) == BLKmode)
1455     return exp;
1456
1457   ret = decl_constant_value (exp);
1458   /* Avoid unwanted tree sharing between the initializer and current
1459      function's body where the tree can be modified e.g. by the
1460      gimplifier.  */
1461   if (ret != exp && TREE_STATIC (exp))
1462     ret = unshare_expr (ret);
1463   return ret;
1464 }
1465
1466 /* Print a warning if a constant expression had overflow in folding.
1467    Invoke this function on every expression that the language
1468    requires to be a constant expression.
1469    Note the ANSI C standard says it is erroneous for a
1470    constant expression to overflow.  */
1471
1472 void
1473 constant_expression_warning (tree value)
1474 {
1475   if (warn_overflow && pedantic
1476       && (TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
1477           || TREE_CODE (value) == FIXED_CST
1478           || TREE_CODE (value) == VECTOR_CST
1479           || TREE_CODE (value) == COMPLEX_CST)
1480       && TREE_OVERFLOW (value))
1481     pedwarn (input_location, OPT_Woverflow, "overflow in constant expression");
1482 }
1483
1484 /* The same as above but print an unconditional error.  */
1485 void
1486 constant_expression_error (tree value)
1487 {
1488   if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
1489        || TREE_CODE (value) == FIXED_CST
1490        || TREE_CODE (value) == VECTOR_CST
1491        || TREE_CODE (value) == COMPLEX_CST)
1492       && TREE_OVERFLOW (value))
1493     error ("overflow in constant expression");
1494 }
1495
1496 /* Print a warning if an expression had overflow in folding and its
1497    operands hadn't.
1498
1499    Invoke this function on every expression that
1500    (1) appears in the source code, and
1501    (2) is a constant expression that overflowed, and
1502    (3) is not already checked by convert_and_check;
1503    however, do not invoke this function on operands of explicit casts
1504    or when the expression is the result of an operator and any operand
1505    already overflowed.  */
1506
1507 void
1508 overflow_warning (location_t loc, tree value)
1509 {
1510   if (c_inhibit_evaluation_warnings != 0)
1511     return;
1512
1513   switch (TREE_CODE (value))
1514     {
1515     case INTEGER_CST:
1516       warning_at (loc, OPT_Woverflow, "integer overflow in expression");
1517       break;
1518
1519     case REAL_CST:
1520       warning_at (loc, OPT_Woverflow,
1521                   "floating point overflow in expression");
1522       break;
1523
1524     case FIXED_CST:
1525       warning_at (loc, OPT_Woverflow, "fixed-point overflow in expression");
1526       break;
1527
1528     case VECTOR_CST:
1529       warning_at (loc, OPT_Woverflow, "vector overflow in expression");
1530       break;
1531
1532     case COMPLEX_CST:
1533       if (TREE_CODE (TREE_REALPART (value)) == INTEGER_CST)
1534         warning_at (loc, OPT_Woverflow,
1535                     "complex integer overflow in expression");
1536       else if (TREE_CODE (TREE_REALPART (value)) == REAL_CST)
1537         warning_at (loc, OPT_Woverflow,
1538                     "complex floating point overflow in expression");
1539       break;
1540
1541     default:
1542       break;
1543     }
1544 }
1545
1546 /* Warn about uses of logical || / && operator in a context where it
1547    is likely that the bitwise equivalent was intended by the
1548    programmer.  We have seen an expression in which CODE is a binary
1549    operator used to combine expressions OP_LEFT and OP_RIGHT, which before folding
1550    had CODE_LEFT and CODE_RIGHT, into an expression of type TYPE.  */
1551 void
1552 warn_logical_operator (location_t location, enum tree_code code, tree type,
1553                        enum tree_code code_left, tree op_left,
1554                        enum tree_code ARG_UNUSED (code_right), tree op_right)
1555 {
1556   int or_op = (code == TRUTH_ORIF_EXPR || code == TRUTH_OR_EXPR);
1557   int in0_p, in1_p, in_p;
1558   tree low0, low1, low, high0, high1, high, lhs, rhs, tem;
1559   bool strict_overflow_p = false;
1560
1561   if (code != TRUTH_ANDIF_EXPR
1562       && code != TRUTH_AND_EXPR
1563       && code != TRUTH_ORIF_EXPR
1564       && code != TRUTH_OR_EXPR)
1565     return;
1566
1567   /* Warn if &&/|| are being used in a context where it is
1568      likely that the bitwise equivalent was intended by the
1569      programmer. That is, an expression such as op && MASK
1570      where op should not be any boolean expression, nor a
1571      constant, and mask seems to be a non-boolean integer constant.  */
1572   if (!truth_value_p (code_left)
1573       && INTEGRAL_TYPE_P (TREE_TYPE (op_left))
1574       && !CONSTANT_CLASS_P (op_left)
1575       && !TREE_NO_WARNING (op_left)
1576       && TREE_CODE (op_right) == INTEGER_CST
1577       && !integer_zerop (op_right)
1578       && !integer_onep (op_right))
1579     {
1580       if (or_op)
1581         warning_at (location, OPT_Wlogical_op, "logical %<or%>"
1582                     " applied to non-boolean constant");
1583       else
1584         warning_at (location, OPT_Wlogical_op, "logical %<and%>"
1585                     " applied to non-boolean constant");
1586       TREE_NO_WARNING (op_left) = true;
1587       return;
1588     }
1589
1590   /* We do not warn for constants because they are typical of macro
1591      expansions that test for features.  */
1592   if (CONSTANT_CLASS_P (op_left) || CONSTANT_CLASS_P (op_right))
1593     return;
1594
1595   /* This warning only makes sense with logical operands.  */
1596   if (!(truth_value_p (TREE_CODE (op_left))
1597         || INTEGRAL_TYPE_P (TREE_TYPE (op_left)))
1598       || !(truth_value_p (TREE_CODE (op_right))
1599            || INTEGRAL_TYPE_P (TREE_TYPE (op_right))))
1600     return;
1601
1602   lhs = make_range (op_left, &in0_p, &low0, &high0, &strict_overflow_p);
1603   rhs = make_range (op_right, &in1_p, &low1, &high1, &strict_overflow_p);
1604
1605   if (lhs && TREE_CODE (lhs) == C_MAYBE_CONST_EXPR)
1606     lhs = C_MAYBE_CONST_EXPR_EXPR (lhs);
1607
1608   if (rhs && TREE_CODE (rhs) == C_MAYBE_CONST_EXPR)
1609     rhs = C_MAYBE_CONST_EXPR_EXPR (rhs);
1610
1611   /* If this is an OR operation, invert both sides; we will invert
1612      again at the end.  */
1613   if (or_op)
1614     in0_p = !in0_p, in1_p = !in1_p;
1615
1616   /* If both expressions are the same, if we can merge the ranges, and we
1617      can build the range test, return it or it inverted.  */
1618   if (lhs && rhs && operand_equal_p (lhs, rhs, 0)
1619       && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
1620                        in1_p, low1, high1)
1621       && 0 != (tem = build_range_check (type, lhs, in_p, low, high)))
1622     {
1623       if (TREE_CODE (tem) != INTEGER_CST)
1624         return;
1625
1626       if (or_op)
1627         warning_at (location, OPT_Wlogical_op,
1628                     "logical %<or%> "
1629                     "of collectively exhaustive tests is always true");
1630       else
1631         warning_at (location, OPT_Wlogical_op,
1632                     "logical %<and%> "
1633                     "of mutually exclusive tests is always false");
1634     }
1635 }
1636
1637
1638 /* Print a warning about casts that might indicate violation
1639    of strict aliasing rules if -Wstrict-aliasing is used and
1640    strict aliasing mode is in effect. OTYPE is the original
1641    TREE_TYPE of EXPR, and TYPE the type we're casting to. */
1642
1643 bool
1644 strict_aliasing_warning (tree otype, tree type, tree expr)
1645 {
1646   /* Strip pointer conversion chains and get to the correct original type.  */
1647   STRIP_NOPS (expr);
1648   otype = TREE_TYPE (expr);
1649
1650   if (!(flag_strict_aliasing
1651         && POINTER_TYPE_P (type)
1652         && POINTER_TYPE_P (otype)
1653         && !VOID_TYPE_P (TREE_TYPE (type)))
1654       /* If the type we are casting to is a ref-all pointer
1655          dereferencing it is always valid.  */
1656       || TYPE_REF_CAN_ALIAS_ALL (type))
1657     return false;
1658
1659   if ((warn_strict_aliasing > 1) && TREE_CODE (expr) == ADDR_EXPR
1660       && (DECL_P (TREE_OPERAND (expr, 0))
1661           || handled_component_p (TREE_OPERAND (expr, 0))))
1662     {
1663       /* Casting the address of an object to non void pointer. Warn
1664          if the cast breaks type based aliasing.  */
1665       if (!COMPLETE_TYPE_P (TREE_TYPE (type)) && warn_strict_aliasing == 2)
1666         {
1667           warning (OPT_Wstrict_aliasing, "type-punning to incomplete type "
1668                    "might break strict-aliasing rules");
1669           return true;
1670         }
1671       else
1672         {
1673           /* warn_strict_aliasing >= 3.   This includes the default (3).
1674              Only warn if the cast is dereferenced immediately.  */
1675           alias_set_type set1 =
1676             get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0)));
1677           alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1678
1679           if (set1 != set2 && set2 != 0
1680               && (set1 == 0 || !alias_sets_conflict_p (set1, set2)))
1681             {
1682               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1683                        "pointer will break strict-aliasing rules");
1684               return true;
1685             }
1686           else if (warn_strict_aliasing == 2
1687                    && !alias_sets_must_conflict_p (set1, set2))
1688             {
1689               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1690                        "pointer might break strict-aliasing rules");
1691               return true;
1692             }
1693         }
1694     }
1695   else
1696     if ((warn_strict_aliasing == 1) && !VOID_TYPE_P (TREE_TYPE (otype)))
1697       {
1698         /* At this level, warn for any conversions, even if an address is
1699            not taken in the same statement.  This will likely produce many
1700            false positives, but could be useful to pinpoint problems that
1701            are not revealed at higher levels.  */
1702         alias_set_type set1 = get_alias_set (TREE_TYPE (otype));
1703         alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1704         if (!COMPLETE_TYPE_P (type)
1705             || !alias_sets_must_conflict_p (set1, set2))
1706           {
1707             warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1708                      "pointer might break strict-aliasing rules");
1709             return true;
1710           }
1711       }
1712
1713   return false;
1714 }
1715
1716 /* Warn for unlikely, improbable, or stupid DECL declarations
1717    of `main'.  */
1718
1719 void
1720 check_main_parameter_types (tree decl)
1721 {
1722   tree args;
1723   int argct = 0;
1724
1725   for (args = TYPE_ARG_TYPES (TREE_TYPE (decl)); args;
1726       args = TREE_CHAIN (args))
1727    {
1728      tree type = args ? TREE_VALUE (args) : 0;
1729
1730      if (type == void_type_node || type == error_mark_node )
1731        break;
1732
1733      ++argct;
1734      switch (argct)
1735        {
1736        case 1:
1737          if (TYPE_MAIN_VARIANT (type) != integer_type_node)
1738            pedwarn (input_location, OPT_Wmain, "first argument of %q+D should be %<int%>",
1739                     decl);
1740          break;
1741
1742        case 2:
1743          if (TREE_CODE (type) != POINTER_TYPE
1744              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1745              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1746                  != char_type_node))
1747            pedwarn (input_location, OPT_Wmain, "second argument of %q+D should be %<char **%>",
1748                     decl);
1749          break;
1750
1751        case 3:
1752          if (TREE_CODE (type) != POINTER_TYPE
1753              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1754              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1755                  != char_type_node))
1756            pedwarn (input_location, OPT_Wmain, "third argument of %q+D should probably be "
1757                     "%<char **%>", decl);
1758          break;
1759        }
1760    }
1761
1762   /* It is intentional that this message does not mention the third
1763     argument because it's only mentioned in an appendix of the
1764     standard.  */
1765   if (argct > 0 && (argct < 2 || argct > 3))
1766     pedwarn (input_location, OPT_Wmain, "%q+D takes only zero or two arguments", decl);
1767 }
1768
1769 /* True if pointers to distinct types T1 and T2 can be converted to
1770    each other without an explicit cast.  Only returns true for opaque
1771    vector types.  */
1772 bool
1773 vector_targets_convertible_p (const_tree t1, const_tree t2)
1774 {
1775   if (TREE_CODE (t1) == VECTOR_TYPE && TREE_CODE (t2) == VECTOR_TYPE
1776       && (TYPE_VECTOR_OPAQUE (t1) || TYPE_VECTOR_OPAQUE (t2))
1777       && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)))
1778     return true;
1779
1780   return false;
1781 }
1782
1783 /* True if vector types T1 and T2 can be converted to each other
1784    without an explicit cast.  If EMIT_LAX_NOTE is true, and T1 and T2
1785    can only be converted with -flax-vector-conversions yet that is not
1786    in effect, emit a note telling the user about that option if such
1787    a note has not previously been emitted.  */
1788 bool
1789 vector_types_convertible_p (const_tree t1, const_tree t2, bool emit_lax_note)
1790 {
1791   static bool emitted_lax_note = false;
1792   bool convertible_lax;
1793
1794   if ((TYPE_VECTOR_OPAQUE (t1) || TYPE_VECTOR_OPAQUE (t2))
1795       && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)))
1796     return true;
1797
1798   convertible_lax =
1799     (tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2))
1800      && (TREE_CODE (TREE_TYPE (t1)) != REAL_TYPE ||
1801          TYPE_PRECISION (t1) == TYPE_PRECISION (t2))
1802      && (INTEGRAL_TYPE_P (TREE_TYPE (t1))
1803          == INTEGRAL_TYPE_P (TREE_TYPE (t2))));
1804
1805   if (!convertible_lax || flag_lax_vector_conversions)
1806     return convertible_lax;
1807
1808   if (TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1809       && lang_hooks.types_compatible_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1810     return true;
1811
1812   if (emit_lax_note && !emitted_lax_note)
1813     {
1814       emitted_lax_note = true;
1815       inform (input_location, "use -flax-vector-conversions to permit "
1816               "conversions between vectors with differing "
1817               "element types or numbers of subparts");
1818     }
1819
1820   return false;
1821 }
1822
1823 /* This is a helper function of build_binary_op.
1824
1825    For certain operations if both args were extended from the same
1826    smaller type, do the arithmetic in that type and then extend.
1827
1828    BITWISE indicates a bitwise operation.
1829    For them, this optimization is safe only if
1830    both args are zero-extended or both are sign-extended.
1831    Otherwise, we might change the result.
1832    Eg, (short)-1 | (unsigned short)-1 is (int)-1
1833    but calculated in (unsigned short) it would be (unsigned short)-1.
1834 */
1835 tree shorten_binary_op (tree result_type, tree op0, tree op1, bool bitwise)
1836 {
1837   int unsigned0, unsigned1;
1838   tree arg0, arg1;
1839   int uns;
1840   tree type;
1841
1842   /* Cast OP0 and OP1 to RESULT_TYPE.  Doing so prevents
1843      excessive narrowing when we call get_narrower below.  For
1844      example, suppose that OP0 is of unsigned int extended
1845      from signed char and that RESULT_TYPE is long long int.
1846      If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
1847      like
1848
1849      (long long int) (unsigned int) signed_char
1850
1851      which get_narrower would narrow down to
1852
1853      (unsigned int) signed char
1854
1855      If we do not cast OP0 first, get_narrower would return
1856      signed_char, which is inconsistent with the case of the
1857      explicit cast.  */
1858   op0 = convert (result_type, op0);
1859   op1 = convert (result_type, op1);
1860
1861   arg0 = get_narrower (op0, &unsigned0);
1862   arg1 = get_narrower (op1, &unsigned1);
1863
1864   /* UNS is 1 if the operation to be done is an unsigned one.  */
1865   uns = TYPE_UNSIGNED (result_type);
1866
1867   /* Handle the case that OP0 (or OP1) does not *contain* a conversion
1868      but it *requires* conversion to FINAL_TYPE.  */
1869
1870   if ((TYPE_PRECISION (TREE_TYPE (op0))
1871        == TYPE_PRECISION (TREE_TYPE (arg0)))
1872       && TREE_TYPE (op0) != result_type)
1873     unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
1874   if ((TYPE_PRECISION (TREE_TYPE (op1))
1875        == TYPE_PRECISION (TREE_TYPE (arg1)))
1876       && TREE_TYPE (op1) != result_type)
1877     unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
1878
1879   /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE.  */
1880
1881   /* For bitwise operations, signedness of nominal type
1882      does not matter.  Consider only how operands were extended.  */
1883   if (bitwise)
1884     uns = unsigned0;
1885
1886   /* Note that in all three cases below we refrain from optimizing
1887      an unsigned operation on sign-extended args.
1888      That would not be valid.  */
1889
1890   /* Both args variable: if both extended in same way
1891      from same width, do it in that width.
1892      Do it unsigned if args were zero-extended.  */
1893   if ((TYPE_PRECISION (TREE_TYPE (arg0))
1894        < TYPE_PRECISION (result_type))
1895       && (TYPE_PRECISION (TREE_TYPE (arg1))
1896           == TYPE_PRECISION (TREE_TYPE (arg0)))
1897       && unsigned0 == unsigned1
1898       && (unsigned0 || !uns))
1899     return c_common_signed_or_unsigned_type
1900       (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
1901
1902   else if (TREE_CODE (arg0) == INTEGER_CST
1903            && (unsigned1 || !uns)
1904            && (TYPE_PRECISION (TREE_TYPE (arg1))
1905                < TYPE_PRECISION (result_type))
1906            && (type
1907                = c_common_signed_or_unsigned_type (unsigned1,
1908                                                    TREE_TYPE (arg1)))
1909            && !POINTER_TYPE_P (type)
1910            && int_fits_type_p (arg0, type))
1911     return type;
1912
1913   else if (TREE_CODE (arg1) == INTEGER_CST
1914            && (unsigned0 || !uns)
1915            && (TYPE_PRECISION (TREE_TYPE (arg0))
1916                < TYPE_PRECISION (result_type))
1917            && (type
1918                = c_common_signed_or_unsigned_type (unsigned0,
1919                                                    TREE_TYPE (arg0)))
1920            && !POINTER_TYPE_P (type)
1921            && int_fits_type_p (arg1, type))
1922     return type;
1923
1924   return result_type;
1925 }
1926
1927 /* Warns if the conversion of EXPR to TYPE may alter a value.
1928    This is a helper function for warnings_for_convert_and_check.  */
1929
1930 static void
1931 conversion_warning (tree type, tree expr)
1932 {
1933   bool give_warning = false;
1934
1935   int i;
1936   const int expr_num_operands = TREE_OPERAND_LENGTH (expr);
1937   tree expr_type = TREE_TYPE (expr);
1938
1939   if (!warn_conversion && !warn_sign_conversion)
1940     return;
1941
1942   /* If any operand is artificial, then this expression was generated
1943      by the compiler and we do not warn.  */
1944   for (i = 0; i < expr_num_operands; i++)
1945     {
1946       tree op = TREE_OPERAND (expr, i);
1947       if (op && DECL_P (op) && DECL_ARTIFICIAL (op))
1948         return;
1949     }
1950
1951   switch (TREE_CODE (expr))
1952     {
1953     case EQ_EXPR:
1954     case NE_EXPR:
1955     case LE_EXPR:
1956     case GE_EXPR:
1957     case LT_EXPR:
1958     case GT_EXPR:
1959     case TRUTH_ANDIF_EXPR:
1960     case TRUTH_ORIF_EXPR:
1961     case TRUTH_AND_EXPR:
1962     case TRUTH_OR_EXPR:
1963     case TRUTH_XOR_EXPR:
1964     case TRUTH_NOT_EXPR:
1965       /* Conversion from boolean to a signed:1 bit-field (which only
1966          can hold the values 0 and -1) doesn't lose information - but
1967          it does change the value.  */
1968       if (TYPE_PRECISION (type) == 1 && !TYPE_UNSIGNED (type))
1969         warning (OPT_Wconversion,
1970                  "conversion to %qT from boolean expression", type);
1971       return;
1972
1973     case REAL_CST:
1974     case INTEGER_CST:
1975
1976       /* Warn for real constant that is not an exact integer converted
1977          to integer type.  */
1978       if (TREE_CODE (expr_type) == REAL_TYPE
1979           && TREE_CODE (type) == INTEGER_TYPE)
1980         {
1981           if (!real_isinteger (TREE_REAL_CST_PTR (expr), TYPE_MODE (expr_type)))
1982             give_warning = true;
1983         }
1984       /* Warn for an integer constant that does not fit into integer type.  */
1985       else if (TREE_CODE (expr_type) == INTEGER_TYPE
1986                && TREE_CODE (type) == INTEGER_TYPE
1987                && !int_fits_type_p (expr, type))
1988         {
1989           if (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (expr_type)
1990               && tree_int_cst_sgn (expr) < 0)
1991             warning (OPT_Wsign_conversion,
1992                      "negative integer implicitly converted to unsigned type");
1993           else if (!TYPE_UNSIGNED (type) && TYPE_UNSIGNED (expr_type))
1994             warning (OPT_Wsign_conversion,  "conversion of unsigned constant "
1995                      "value to negative integer");
1996           else
1997             give_warning = true;
1998         }
1999       else if (TREE_CODE (type) == REAL_TYPE)
2000         {
2001           /* Warn for an integer constant that does not fit into real type.  */
2002           if (TREE_CODE (expr_type) == INTEGER_TYPE)
2003             {
2004               REAL_VALUE_TYPE a = real_value_from_int_cst (0, expr);
2005               if (!exact_real_truncate (TYPE_MODE (type), &a))
2006                 give_warning = true;
2007             }
2008           /* Warn for a real constant that does not fit into a smaller
2009              real type.  */
2010           else if (TREE_CODE (expr_type) == REAL_TYPE
2011                    && TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2012             {
2013               REAL_VALUE_TYPE a = TREE_REAL_CST (expr);
2014               if (!exact_real_truncate (TYPE_MODE (type), &a))
2015                 give_warning = true;
2016             }
2017         }
2018
2019       if (give_warning)
2020         warning (OPT_Wconversion,
2021                  "conversion to %qT alters %qT constant value",
2022                  type, expr_type);
2023
2024       return;
2025
2026     case COND_EXPR:
2027       {
2028         /* In case of COND_EXPR, if both operands are constants or
2029            COND_EXPR, then we do not care about the type of COND_EXPR,
2030            only about the conversion of each operand.  */
2031         tree op1 = TREE_OPERAND (expr, 1);
2032         tree op2 = TREE_OPERAND (expr, 2);
2033
2034         if ((TREE_CODE (op1) == REAL_CST || TREE_CODE (op1) == INTEGER_CST
2035              || TREE_CODE (op1) == COND_EXPR)
2036             && (TREE_CODE (op2) == REAL_CST || TREE_CODE (op2) == INTEGER_CST
2037                 || TREE_CODE (op2) == COND_EXPR))
2038           {
2039             conversion_warning (type, op1);
2040             conversion_warning (type, op2);
2041             return;
2042           }
2043         /* Fall through.  */
2044       }
2045
2046     default: /* 'expr' is not a constant.  */
2047
2048       /* Warn for real types converted to integer types.  */
2049       if (TREE_CODE (expr_type) == REAL_TYPE
2050           && TREE_CODE (type) == INTEGER_TYPE)
2051         give_warning = true;
2052
2053       else if (TREE_CODE (expr_type) == INTEGER_TYPE
2054                && TREE_CODE (type) == INTEGER_TYPE)
2055         {
2056           /* Don't warn about unsigned char y = 0xff, x = (int) y;  */
2057           expr = get_unwidened (expr, 0);
2058           expr_type = TREE_TYPE (expr);
2059
2060           /* Don't warn for short y; short x = ((int)y & 0xff);  */
2061           if (TREE_CODE (expr) == BIT_AND_EXPR
2062                 || TREE_CODE (expr) == BIT_IOR_EXPR
2063               || TREE_CODE (expr) == BIT_XOR_EXPR)
2064             {
2065               /* If both args were extended from a shortest type,
2066                  use that type if that is safe.  */
2067               expr_type = shorten_binary_op (expr_type,
2068                                              TREE_OPERAND (expr, 0),
2069                                              TREE_OPERAND (expr, 1),
2070                                              /* bitwise */1);
2071
2072               if (TREE_CODE (expr) == BIT_AND_EXPR)
2073                 {
2074                   tree op0 = TREE_OPERAND (expr, 0);
2075                   tree op1 = TREE_OPERAND (expr, 1);
2076                   bool unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
2077                   bool unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
2078
2079                   /* If one of the operands is a non-negative constant
2080                      that fits in the target type, then the type of the
2081                      other operand does not matter. */
2082                   if ((TREE_CODE (op0) == INTEGER_CST
2083                        && int_fits_type_p (op0, c_common_signed_type (type))
2084                        && int_fits_type_p (op0, c_common_unsigned_type (type)))
2085                       || (TREE_CODE (op1) == INTEGER_CST
2086                           && int_fits_type_p (op1, c_common_signed_type (type))
2087                           && int_fits_type_p (op1,
2088                                               c_common_unsigned_type (type))))
2089                     return;
2090                   /* If constant is unsigned and fits in the target
2091                      type, then the result will also fit.  */
2092                   else if ((TREE_CODE (op0) == INTEGER_CST
2093                             && unsigned0
2094                             && int_fits_type_p (op0, type))
2095                            || (TREE_CODE (op1) == INTEGER_CST
2096                                && unsigned1
2097                                && int_fits_type_p (op1, type)))
2098                     return;
2099                 }
2100             }
2101           /* Warn for integer types converted to smaller integer types.  */
2102           if (TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2103             give_warning = true;
2104
2105           /* When they are the same width but different signedness,
2106              then the value may change.  */
2107           else if ((TYPE_PRECISION (type) == TYPE_PRECISION (expr_type)
2108                     && TYPE_UNSIGNED (expr_type) != TYPE_UNSIGNED (type))
2109                    /* Even when converted to a bigger type, if the type is
2110                       unsigned but expr is signed, then negative values
2111                       will be changed.  */
2112                    || (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (expr_type)))
2113             warning (OPT_Wsign_conversion, "conversion to %qT from %qT "
2114                      "may change the sign of the result",
2115                      type, expr_type);
2116         }
2117
2118       /* Warn for integer types converted to real types if and only if
2119          all the range of values of the integer type cannot be
2120          represented by the real type.  */
2121       else if (TREE_CODE (expr_type) == INTEGER_TYPE
2122                && TREE_CODE (type) == REAL_TYPE)
2123         {
2124           tree type_low_bound = TYPE_MIN_VALUE (expr_type);
2125           tree type_high_bound = TYPE_MAX_VALUE (expr_type);
2126           REAL_VALUE_TYPE real_low_bound
2127             = real_value_from_int_cst (0, type_low_bound);
2128           REAL_VALUE_TYPE real_high_bound
2129             = real_value_from_int_cst (0, type_high_bound);
2130
2131           if (!exact_real_truncate (TYPE_MODE (type), &real_low_bound)
2132               || !exact_real_truncate (TYPE_MODE (type), &real_high_bound))
2133             give_warning = true;
2134         }
2135
2136       /* Warn for real types converted to smaller real types.  */
2137       else if (TREE_CODE (expr_type) == REAL_TYPE
2138                && TREE_CODE (type) == REAL_TYPE
2139                && TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2140         give_warning = true;
2141
2142
2143       if (give_warning)
2144         warning (OPT_Wconversion,
2145                  "conversion to %qT from %qT may alter its value",
2146                  type, expr_type);
2147     }
2148 }
2149
2150 /* Produce warnings after a conversion. RESULT is the result of
2151    converting EXPR to TYPE.  This is a helper function for
2152    convert_and_check and cp_convert_and_check.  */
2153
2154 void
2155 warnings_for_convert_and_check (tree type, tree expr, tree result)
2156 {
2157   if (TREE_CODE (expr) == INTEGER_CST
2158       && (TREE_CODE (type) == INTEGER_TYPE
2159           || TREE_CODE (type) == ENUMERAL_TYPE)
2160       && !int_fits_type_p (expr, type))
2161     {
2162       /* Do not diagnose overflow in a constant expression merely
2163          because a conversion overflowed.  */
2164       if (TREE_OVERFLOW (result))
2165         TREE_OVERFLOW (result) = TREE_OVERFLOW (expr);
2166
2167       if (TYPE_UNSIGNED (type))
2168         {
2169           /* This detects cases like converting -129 or 256 to
2170              unsigned char.  */
2171           if (!int_fits_type_p (expr, c_common_signed_type (type)))
2172             warning (OPT_Woverflow,
2173                      "large integer implicitly truncated to unsigned type");
2174           else
2175             conversion_warning (type, expr);
2176         }
2177       else if (!int_fits_type_p (expr, c_common_unsigned_type (type)))
2178         warning (OPT_Woverflow,
2179                  "overflow in implicit constant conversion");
2180       /* No warning for converting 0x80000000 to int.  */
2181       else if (pedantic
2182                && (TREE_CODE (TREE_TYPE (expr)) != INTEGER_TYPE
2183                    || TYPE_PRECISION (TREE_TYPE (expr))
2184                    != TYPE_PRECISION (type)))
2185         warning (OPT_Woverflow,
2186                  "overflow in implicit constant conversion");
2187
2188       else
2189         conversion_warning (type, expr);
2190     }
2191   else if ((TREE_CODE (result) == INTEGER_CST
2192             || TREE_CODE (result) == FIXED_CST) && TREE_OVERFLOW (result))
2193     warning (OPT_Woverflow,
2194              "overflow in implicit constant conversion");
2195   else
2196     conversion_warning (type, expr);
2197 }
2198
2199
2200 /* Convert EXPR to TYPE, warning about conversion problems with constants.
2201    Invoke this function on every expression that is converted implicitly,
2202    i.e. because of language rules and not because of an explicit cast.  */
2203
2204 tree
2205 convert_and_check (tree type, tree expr)
2206 {
2207   tree result;
2208   tree expr_for_warning;
2209
2210   /* Convert from a value with possible excess precision rather than
2211      via the semantic type, but do not warn about values not fitting
2212      exactly in the semantic type.  */
2213   if (TREE_CODE (expr) == EXCESS_PRECISION_EXPR)
2214     {
2215       tree orig_type = TREE_TYPE (expr);
2216       expr = TREE_OPERAND (expr, 0);
2217       expr_for_warning = convert (orig_type, expr);
2218       if (orig_type == type)
2219         return expr_for_warning;
2220     }
2221   else
2222     expr_for_warning = expr;
2223
2224   if (TREE_TYPE (expr) == type)
2225     return expr;
2226
2227   result = convert (type, expr);
2228
2229   if (c_inhibit_evaluation_warnings == 0
2230       && !TREE_OVERFLOW_P (expr)
2231       && result != error_mark_node)
2232     warnings_for_convert_and_check (type, expr_for_warning, result);
2233
2234   return result;
2235 }
2236 \f
2237 /* A node in a list that describes references to variables (EXPR), which are
2238    either read accesses if WRITER is zero, or write accesses, in which case
2239    WRITER is the parent of EXPR.  */
2240 struct tlist
2241 {
2242   struct tlist *next;
2243   tree expr, writer;
2244 };
2245
2246 /* Used to implement a cache the results of a call to verify_tree.  We only
2247    use this for SAVE_EXPRs.  */
2248 struct tlist_cache
2249 {
2250   struct tlist_cache *next;
2251   struct tlist *cache_before_sp;
2252   struct tlist *cache_after_sp;
2253   tree expr;
2254 };
2255
2256 /* Obstack to use when allocating tlist structures, and corresponding
2257    firstobj.  */
2258 static struct obstack tlist_obstack;
2259 static char *tlist_firstobj = 0;
2260
2261 /* Keep track of the identifiers we've warned about, so we can avoid duplicate
2262    warnings.  */
2263 static struct tlist *warned_ids;
2264 /* SAVE_EXPRs need special treatment.  We process them only once and then
2265    cache the results.  */
2266 static struct tlist_cache *save_expr_cache;
2267
2268 static void add_tlist (struct tlist **, struct tlist *, tree, int);
2269 static void merge_tlist (struct tlist **, struct tlist *, int);
2270 static void verify_tree (tree, struct tlist **, struct tlist **, tree);
2271 static int warning_candidate_p (tree);
2272 static bool candidate_equal_p (const_tree, const_tree);
2273 static void warn_for_collisions (struct tlist *);
2274 static void warn_for_collisions_1 (tree, tree, struct tlist *, int);
2275 static struct tlist *new_tlist (struct tlist *, tree, tree);
2276
2277 /* Create a new struct tlist and fill in its fields.  */
2278 static struct tlist *
2279 new_tlist (struct tlist *next, tree t, tree writer)
2280 {
2281   struct tlist *l;
2282   l = XOBNEW (&tlist_obstack, struct tlist);
2283   l->next = next;
2284   l->expr = t;
2285   l->writer = writer;
2286   return l;
2287 }
2288
2289 /* Add duplicates of the nodes found in ADD to the list *TO.  If EXCLUDE_WRITER
2290    is nonnull, we ignore any node we find which has a writer equal to it.  */
2291
2292 static void
2293 add_tlist (struct tlist **to, struct tlist *add, tree exclude_writer, int copy)
2294 {
2295   while (add)
2296     {
2297       struct tlist *next = add->next;
2298       if (!copy)
2299         add->next = *to;
2300       if (!exclude_writer || !candidate_equal_p (add->writer, exclude_writer))
2301         *to = copy ? new_tlist (*to, add->expr, add->writer) : add;
2302       add = next;
2303     }
2304 }
2305
2306 /* Merge the nodes of ADD into TO.  This merging process is done so that for
2307    each variable that already exists in TO, no new node is added; however if
2308    there is a write access recorded in ADD, and an occurrence on TO is only
2309    a read access, then the occurrence in TO will be modified to record the
2310    write.  */
2311
2312 static void
2313 merge_tlist (struct tlist **to, struct tlist *add, int copy)
2314 {
2315   struct tlist **end = to;
2316
2317   while (*end)
2318     end = &(*end)->next;
2319
2320   while (add)
2321     {
2322       int found = 0;
2323       struct tlist *tmp2;
2324       struct tlist *next = add->next;
2325
2326       for (tmp2 = *to; tmp2; tmp2 = tmp2->next)
2327         if (candidate_equal_p (tmp2->expr, add->expr))
2328           {
2329             found = 1;
2330             if (!tmp2->writer)
2331               tmp2->writer = add->writer;
2332           }
2333       if (!found)
2334         {
2335           *end = copy ? add : new_tlist (NULL, add->expr, add->writer);
2336           end = &(*end)->next;
2337           *end = 0;
2338         }
2339       add = next;
2340     }
2341 }
2342
2343 /* WRITTEN is a variable, WRITER is its parent.  Warn if any of the variable
2344    references in list LIST conflict with it, excluding reads if ONLY writers
2345    is nonzero.  */
2346
2347 static void
2348 warn_for_collisions_1 (tree written, tree writer, struct tlist *list,
2349                        int only_writes)
2350 {
2351   struct tlist *tmp;
2352
2353   /* Avoid duplicate warnings.  */
2354   for (tmp = warned_ids; tmp; tmp = tmp->next)
2355     if (candidate_equal_p (tmp->expr, written))
2356       return;
2357
2358   while (list)
2359     {
2360       if (candidate_equal_p (list->expr, written)
2361           && !candidate_equal_p (list->writer, writer)
2362           && (!only_writes || list->writer))
2363         {
2364           warned_ids = new_tlist (warned_ids, written, NULL_TREE);
2365           warning_at (EXPR_HAS_LOCATION (writer)
2366                       ? EXPR_LOCATION (writer) : input_location,
2367                       OPT_Wsequence_point, "operation on %qE may be undefined",
2368                       list->expr);
2369         }
2370       list = list->next;
2371     }
2372 }
2373
2374 /* Given a list LIST of references to variables, find whether any of these
2375    can cause conflicts due to missing sequence points.  */
2376
2377 static void
2378 warn_for_collisions (struct tlist *list)
2379 {
2380   struct tlist *tmp;
2381
2382   for (tmp = list; tmp; tmp = tmp->next)
2383     {
2384       if (tmp->writer)
2385         warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0);
2386     }
2387 }
2388
2389 /* Return nonzero if X is a tree that can be verified by the sequence point
2390    warnings.  */
2391 static int
2392 warning_candidate_p (tree x)
2393 {
2394   /* !VOID_TYPE_P (TREE_TYPE (x)) is workaround for cp/tree.c
2395      (lvalue_p) crash on TRY/CATCH. */
2396   return !(DECL_P (x) && DECL_ARTIFICIAL (x))
2397     && TREE_TYPE (x) && !VOID_TYPE_P (TREE_TYPE (x)) && lvalue_p (x);
2398 }
2399
2400 /* Return nonzero if X and Y appear to be the same candidate (or NULL) */
2401 static bool
2402 candidate_equal_p (const_tree x, const_tree y)
2403 {
2404   return (x == y) || (x && y && operand_equal_p (x, y, 0));
2405 }
2406
2407 /* Walk the tree X, and record accesses to variables.  If X is written by the
2408    parent tree, WRITER is the parent.
2409    We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP.  If this
2410    expression or its only operand forces a sequence point, then everything up
2411    to the sequence point is stored in PBEFORE_SP.  Everything else gets stored
2412    in PNO_SP.
2413    Once we return, we will have emitted warnings if any subexpression before
2414    such a sequence point could be undefined.  On a higher level, however, the
2415    sequence point may not be relevant, and we'll merge the two lists.
2416
2417    Example: (b++, a) + b;
2418    The call that processes the COMPOUND_EXPR will store the increment of B
2419    in PBEFORE_SP, and the use of A in PNO_SP.  The higher-level call that
2420    processes the PLUS_EXPR will need to merge the two lists so that
2421    eventually, all accesses end up on the same list (and we'll warn about the
2422    unordered subexpressions b++ and b.
2423
2424    A note on merging.  If we modify the former example so that our expression
2425    becomes
2426      (b++, b) + a
2427    care must be taken not simply to add all three expressions into the final
2428    PNO_SP list.  The function merge_tlist takes care of that by merging the
2429    before-SP list of the COMPOUND_EXPR into its after-SP list in a special
2430    way, so that no more than one access to B is recorded.  */
2431
2432 static void
2433 verify_tree (tree x, struct tlist **pbefore_sp, struct tlist **pno_sp,
2434              tree writer)
2435 {
2436   struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3;
2437   enum tree_code code;
2438   enum tree_code_class cl;
2439
2440   /* X may be NULL if it is the operand of an empty statement expression
2441      ({ }).  */
2442   if (x == NULL)
2443     return;
2444
2445  restart:
2446   code = TREE_CODE (x);
2447   cl = TREE_CODE_CLASS (code);
2448
2449   if (warning_candidate_p (x))
2450     *pno_sp = new_tlist (*pno_sp, x, writer);
2451
2452   switch (code)
2453     {
2454     case CONSTRUCTOR:
2455       return;
2456
2457     case COMPOUND_EXPR:
2458     case TRUTH_ANDIF_EXPR:
2459     case TRUTH_ORIF_EXPR:
2460       tmp_before = tmp_nosp = tmp_list3 = 0;
2461       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
2462       warn_for_collisions (tmp_nosp);
2463       merge_tlist (pbefore_sp, tmp_before, 0);
2464       merge_tlist (pbefore_sp, tmp_nosp, 0);
2465       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE);
2466       merge_tlist (pbefore_sp, tmp_list3, 0);
2467       return;
2468
2469     case COND_EXPR:
2470       tmp_before = tmp_list2 = 0;
2471       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE);
2472       warn_for_collisions (tmp_list2);
2473       merge_tlist (pbefore_sp, tmp_before, 0);
2474       merge_tlist (pbefore_sp, tmp_list2, 1);
2475
2476       tmp_list3 = tmp_nosp = 0;
2477       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE);
2478       warn_for_collisions (tmp_nosp);
2479       merge_tlist (pbefore_sp, tmp_list3, 0);
2480
2481       tmp_list3 = tmp_list2 = 0;
2482       verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE);
2483       warn_for_collisions (tmp_list2);
2484       merge_tlist (pbefore_sp, tmp_list3, 0);
2485       /* Rather than add both tmp_nosp and tmp_list2, we have to merge the
2486          two first, to avoid warning for (a ? b++ : b++).  */
2487       merge_tlist (&tmp_nosp, tmp_list2, 0);
2488       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2489       return;
2490
2491     case PREDECREMENT_EXPR:
2492     case PREINCREMENT_EXPR:
2493     case POSTDECREMENT_EXPR:
2494     case POSTINCREMENT_EXPR:
2495       verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x);
2496       return;
2497
2498     case MODIFY_EXPR:
2499       tmp_before = tmp_nosp = tmp_list3 = 0;
2500       verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE);
2501       verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x);
2502       /* Expressions inside the LHS are not ordered wrt. the sequence points
2503          in the RHS.  Example:
2504            *a = (a++, 2)
2505          Despite the fact that the modification of "a" is in the before_sp
2506          list (tmp_before), it conflicts with the use of "a" in the LHS.
2507          We can handle this by adding the contents of tmp_list3
2508          to those of tmp_before, and redoing the collision warnings for that
2509          list.  */
2510       add_tlist (&tmp_before, tmp_list3, x, 1);
2511       warn_for_collisions (tmp_before);
2512       /* Exclude the LHS itself here; we first have to merge it into the
2513          tmp_nosp list.  This is done to avoid warning for "a = a"; if we
2514          didn't exclude the LHS, we'd get it twice, once as a read and once
2515          as a write.  */
2516       add_tlist (pno_sp, tmp_list3, x, 0);
2517       warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1);
2518
2519       merge_tlist (pbefore_sp, tmp_before, 0);
2520       if (warning_candidate_p (TREE_OPERAND (x, 0)))
2521         merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0);
2522       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1);
2523       return;
2524
2525     case CALL_EXPR:
2526       /* We need to warn about conflicts among arguments and conflicts between
2527          args and the function address.  Side effects of the function address,
2528          however, are not ordered by the sequence point of the call.  */
2529       {
2530         call_expr_arg_iterator iter;
2531         tree arg;
2532         tmp_before = tmp_nosp = 0;
2533         verify_tree (CALL_EXPR_FN (x), &tmp_before, &tmp_nosp, NULL_TREE);
2534         FOR_EACH_CALL_EXPR_ARG (arg, iter, x)
2535           {
2536             tmp_list2 = tmp_list3 = 0;
2537             verify_tree (arg, &tmp_list2, &tmp_list3, NULL_TREE);
2538             merge_tlist (&tmp_list3, tmp_list2, 0);
2539             add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0);
2540           }
2541         add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0);
2542         warn_for_collisions (tmp_before);
2543         add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0);
2544         return;
2545       }
2546
2547     case TREE_LIST:
2548       /* Scan all the list, e.g. indices of multi dimensional array.  */
2549       while (x)
2550         {
2551           tmp_before = tmp_nosp = 0;
2552           verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE);
2553           merge_tlist (&tmp_nosp, tmp_before, 0);
2554           add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2555           x = TREE_CHAIN (x);
2556         }
2557       return;
2558
2559     case SAVE_EXPR:
2560       {
2561         struct tlist_cache *t;
2562         for (t = save_expr_cache; t; t = t->next)
2563           if (candidate_equal_p (t->expr, x))
2564             break;
2565
2566         if (!t)
2567           {
2568             t = XOBNEW (&tlist_obstack, struct tlist_cache);
2569             t->next = save_expr_cache;
2570             t->expr = x;
2571             save_expr_cache = t;
2572
2573             tmp_before = tmp_nosp = 0;
2574             verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
2575             warn_for_collisions (tmp_nosp);
2576
2577             tmp_list3 = 0;
2578             while (tmp_nosp)
2579               {
2580                 struct tlist *t = tmp_nosp;
2581                 tmp_nosp = t->next;
2582                 merge_tlist (&tmp_list3, t, 0);
2583               }
2584             t->cache_before_sp = tmp_before;
2585             t->cache_after_sp = tmp_list3;
2586           }
2587         merge_tlist (pbefore_sp, t->cache_before_sp, 1);
2588         add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1);
2589         return;
2590       }
2591
2592     case ADDR_EXPR:
2593       x = TREE_OPERAND (x, 0);
2594       if (DECL_P (x))
2595         return;
2596       writer = 0;
2597       goto restart;
2598
2599     default:
2600       /* For other expressions, simply recurse on their operands.
2601          Manual tail recursion for unary expressions.
2602          Other non-expressions need not be processed.  */
2603       if (cl == tcc_unary)
2604         {
2605           x = TREE_OPERAND (x, 0);
2606           writer = 0;
2607           goto restart;
2608         }
2609       else if (IS_EXPR_CODE_CLASS (cl))
2610         {
2611           int lp;
2612           int max = TREE_OPERAND_LENGTH (x);
2613           for (lp = 0; lp < max; lp++)
2614             {
2615               tmp_before = tmp_nosp = 0;
2616               verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, 0);
2617               merge_tlist (&tmp_nosp, tmp_before, 0);
2618               add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2619             }
2620         }
2621       return;
2622     }
2623 }
2624
2625 /* Try to warn for undefined behavior in EXPR due to missing sequence
2626    points.  */
2627
2628 void
2629 verify_sequence_points (tree expr)
2630 {
2631   struct tlist *before_sp = 0, *after_sp = 0;
2632
2633   warned_ids = 0;
2634   save_expr_cache = 0;
2635   if (tlist_firstobj == 0)
2636     {
2637       gcc_obstack_init (&tlist_obstack);
2638       tlist_firstobj = (char *) obstack_alloc (&tlist_obstack, 0);
2639     }
2640
2641   verify_tree (expr, &before_sp, &after_sp, 0);
2642   warn_for_collisions (after_sp);
2643   obstack_free (&tlist_obstack, tlist_firstobj);
2644 }
2645 \f
2646 /* Validate the expression after `case' and apply default promotions.  */
2647
2648 static tree
2649 check_case_value (tree value)
2650 {
2651   if (value == NULL_TREE)
2652     return value;
2653
2654   /* ??? Can we ever get nops here for a valid case value?  We
2655      shouldn't for C.  */
2656   STRIP_TYPE_NOPS (value);
2657   /* In C++, the following is allowed:
2658
2659        const int i = 3;
2660        switch (...) { case i: ... }
2661
2662      So, we try to reduce the VALUE to a constant that way.  */
2663   if (c_dialect_cxx ())
2664     {
2665       value = decl_constant_value (value);
2666       STRIP_TYPE_NOPS (value);
2667       value = fold (value);
2668     }
2669
2670   if (TREE_CODE (value) == INTEGER_CST)
2671     /* Promote char or short to int.  */
2672     value = perform_integral_promotions (value);
2673   else if (value != error_mark_node)
2674     {
2675       error ("case label does not reduce to an integer constant");
2676       value = error_mark_node;
2677     }
2678
2679   constant_expression_warning (value);
2680
2681   return value;
2682 }
2683 \f
2684 /* See if the case values LOW and HIGH are in the range of the original
2685    type (i.e. before the default conversion to int) of the switch testing
2686    expression.
2687    TYPE is the promoted type of the testing expression, and ORIG_TYPE is
2688    the type before promoting it.  CASE_LOW_P is a pointer to the lower
2689    bound of the case label, and CASE_HIGH_P is the upper bound or NULL
2690    if the case is not a case range.
2691    The caller has to make sure that we are not called with NULL for
2692    CASE_LOW_P (i.e. the default case).
2693    Returns true if the case label is in range of ORIG_TYPE (saturated or
2694    untouched) or false if the label is out of range.  */
2695
2696 static bool
2697 check_case_bounds (tree type, tree orig_type,
2698                    tree *case_low_p, tree *case_high_p)
2699 {
2700   tree min_value, max_value;
2701   tree case_low = *case_low_p;
2702   tree case_high = case_high_p ? *case_high_p : case_low;
2703
2704   /* If there was a problem with the original type, do nothing.  */
2705   if (orig_type == error_mark_node)
2706     return true;
2707
2708   min_value = TYPE_MIN_VALUE (orig_type);
2709   max_value = TYPE_MAX_VALUE (orig_type);
2710
2711   /* Case label is less than minimum for type.  */
2712   if (tree_int_cst_compare (case_low, min_value) < 0
2713       && tree_int_cst_compare (case_high, min_value) < 0)
2714     {
2715       warning (0, "case label value is less than minimum value for type");
2716       return false;
2717     }
2718
2719   /* Case value is greater than maximum for type.  */
2720   if (tree_int_cst_compare (case_low, max_value) > 0
2721       && tree_int_cst_compare (case_high, max_value) > 0)
2722     {
2723       warning (0, "case label value exceeds maximum value for type");
2724       return false;
2725     }
2726
2727   /* Saturate lower case label value to minimum.  */
2728   if (tree_int_cst_compare (case_high, min_value) >= 0
2729       && tree_int_cst_compare (case_low, min_value) < 0)
2730     {
2731       warning (0, "lower value in case label range"
2732                " less than minimum value for type");
2733       case_low = min_value;
2734     }
2735
2736   /* Saturate upper case label value to maximum.  */
2737   if (tree_int_cst_compare (case_low, max_value) <= 0
2738       && tree_int_cst_compare (case_high, max_value) > 0)
2739     {
2740       warning (0, "upper value in case label range"
2741                " exceeds maximum value for type");
2742       case_high = max_value;
2743     }
2744
2745   if (*case_low_p != case_low)
2746     *case_low_p = convert (type, case_low);
2747   if (case_high_p && *case_high_p != case_high)
2748     *case_high_p = convert (type, case_high);
2749
2750   return true;
2751 }
2752 \f
2753 /* Return an integer type with BITS bits of precision,
2754    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
2755
2756 tree
2757 c_common_type_for_size (unsigned int bits, int unsignedp)
2758 {
2759   if (bits == TYPE_PRECISION (integer_type_node))
2760     return unsignedp ? unsigned_type_node : integer_type_node;
2761
2762   if (bits == TYPE_PRECISION (signed_char_type_node))
2763     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2764
2765   if (bits == TYPE_PRECISION (short_integer_type_node))
2766     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2767
2768   if (bits == TYPE_PRECISION (long_integer_type_node))
2769     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2770
2771   if (bits == TYPE_PRECISION (long_long_integer_type_node))
2772     return (unsignedp ? long_long_unsigned_type_node
2773             : long_long_integer_type_node);
2774
2775   if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
2776     return (unsignedp ? widest_unsigned_literal_type_node
2777             : widest_integer_literal_type_node);
2778
2779   if (bits <= TYPE_PRECISION (intQI_type_node))
2780     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2781
2782   if (bits <= TYPE_PRECISION (intHI_type_node))
2783     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2784
2785   if (bits <= TYPE_PRECISION (intSI_type_node))
2786     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2787
2788   if (bits <= TYPE_PRECISION (intDI_type_node))
2789     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2790
2791   return 0;
2792 }
2793
2794 /* Return a fixed-point type that has at least IBIT ibits and FBIT fbits
2795    that is unsigned if UNSIGNEDP is nonzero, otherwise signed;
2796    and saturating if SATP is nonzero, otherwise not saturating.  */
2797
2798 tree
2799 c_common_fixed_point_type_for_size (unsigned int ibit, unsigned int fbit,
2800                                     int unsignedp, int satp)
2801 {
2802   enum machine_mode mode;
2803   if (ibit == 0)
2804     mode = unsignedp ? UQQmode : QQmode;
2805   else
2806     mode = unsignedp ? UHAmode : HAmode;
2807
2808   for (; mode != VOIDmode; mode = GET_MODE_WIDER_MODE (mode))
2809     if (GET_MODE_IBIT (mode) >= ibit && GET_MODE_FBIT (mode) >= fbit)
2810       break;
2811
2812   if (mode == VOIDmode || !targetm.scalar_mode_supported_p (mode))
2813     {
2814       sorry ("GCC cannot support operators with integer types and "
2815              "fixed-point types that have too many integral and "
2816              "fractional bits together");
2817       return 0;
2818     }
2819
2820   return c_common_type_for_mode (mode, satp);
2821 }
2822
2823 /* Used for communication between c_common_type_for_mode and
2824    c_register_builtin_type.  */
2825 static GTY(()) tree registered_builtin_types;
2826
2827 /* Return a data type that has machine mode MODE.
2828    If the mode is an integer,
2829    then UNSIGNEDP selects between signed and unsigned types.
2830    If the mode is a fixed-point mode,
2831    then UNSIGNEDP selects between saturating and nonsaturating types.  */
2832
2833 tree
2834 c_common_type_for_mode (enum machine_mode mode, int unsignedp)
2835 {
2836   tree t;
2837
2838   if (mode == TYPE_MODE (integer_type_node))
2839     return unsignedp ? unsigned_type_node : integer_type_node;
2840
2841   if (mode == TYPE_MODE (signed_char_type_node))
2842     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2843
2844   if (mode == TYPE_MODE (short_integer_type_node))
2845     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2846
2847   if (mode == TYPE_MODE (long_integer_type_node))
2848     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2849
2850   if (mode == TYPE_MODE (long_long_integer_type_node))
2851     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
2852
2853   if (mode == TYPE_MODE (widest_integer_literal_type_node))
2854     return unsignedp ? widest_unsigned_literal_type_node
2855                      : widest_integer_literal_type_node;
2856
2857   if (mode == QImode)
2858     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2859
2860   if (mode == HImode)
2861     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2862
2863   if (mode == SImode)
2864     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2865
2866   if (mode == DImode)
2867     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2868
2869 #if HOST_BITS_PER_WIDE_INT >= 64
2870   if (mode == TYPE_MODE (intTI_type_node))
2871     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
2872 #endif
2873
2874   if (mode == TYPE_MODE (float_type_node))
2875     return float_type_node;
2876
2877   if (mode == TYPE_MODE (double_type_node))
2878     return double_type_node;
2879
2880   if (mode == TYPE_MODE (long_double_type_node))
2881     return long_double_type_node;
2882
2883   if (mode == TYPE_MODE (void_type_node))
2884     return void_type_node;
2885
2886   if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
2887     return (unsignedp
2888             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2889             : make_signed_type (GET_MODE_PRECISION (mode)));
2890
2891   if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
2892     return (unsignedp
2893             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2894             : make_signed_type (GET_MODE_PRECISION (mode)));
2895
2896   if (COMPLEX_MODE_P (mode))
2897     {
2898       enum machine_mode inner_mode;
2899       tree inner_type;
2900
2901       if (mode == TYPE_MODE (complex_float_type_node))
2902         return complex_float_type_node;
2903       if (mode == TYPE_MODE (complex_double_type_node))
2904         return complex_double_type_node;
2905       if (mode == TYPE_MODE (complex_long_double_type_node))
2906         return complex_long_double_type_node;
2907
2908       if (mode == TYPE_MODE (complex_integer_type_node) && !unsignedp)
2909         return complex_integer_type_node;
2910
2911       inner_mode = GET_MODE_INNER (mode);
2912       inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2913       if (inner_type != NULL_TREE)
2914         return build_complex_type (inner_type);
2915     }
2916   else if (VECTOR_MODE_P (mode))
2917     {
2918       enum machine_mode inner_mode = GET_MODE_INNER (mode);
2919       tree inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2920       if (inner_type != NULL_TREE)
2921         return build_vector_type_for_mode (inner_type, mode);
2922     }
2923
2924   if (mode == TYPE_MODE (dfloat32_type_node))
2925     return dfloat32_type_node;
2926   if (mode == TYPE_MODE (dfloat64_type_node))
2927     return dfloat64_type_node;
2928   if (mode == TYPE_MODE (dfloat128_type_node))
2929     return dfloat128_type_node;
2930
2931   if (ALL_SCALAR_FIXED_POINT_MODE_P (mode))
2932     {
2933       if (mode == TYPE_MODE (short_fract_type_node))
2934         return unsignedp ? sat_short_fract_type_node : short_fract_type_node;
2935       if (mode == TYPE_MODE (fract_type_node))
2936         return unsignedp ? sat_fract_type_node : fract_type_node;
2937       if (mode == TYPE_MODE (long_fract_type_node))
2938         return unsignedp ? sat_long_fract_type_node : long_fract_type_node;
2939       if (mode == TYPE_MODE (long_long_fract_type_node))
2940         return unsignedp ? sat_long_long_fract_type_node
2941                          : long_long_fract_type_node;
2942
2943       if (mode == TYPE_MODE (unsigned_short_fract_type_node))
2944         return unsignedp ? sat_unsigned_short_fract_type_node
2945                          : unsigned_short_fract_type_node;
2946       if (mode == TYPE_MODE (unsigned_fract_type_node))
2947         return unsignedp ? sat_unsigned_fract_type_node
2948                          : unsigned_fract_type_node;
2949       if (mode == TYPE_MODE (unsigned_long_fract_type_node))
2950         return unsignedp ? sat_unsigned_long_fract_type_node
2951                          : unsigned_long_fract_type_node;
2952       if (mode == TYPE_MODE (unsigned_long_long_fract_type_node))
2953         return unsignedp ? sat_unsigned_long_long_fract_type_node
2954                          : unsigned_long_long_fract_type_node;
2955
2956       if (mode == TYPE_MODE (short_accum_type_node))
2957         return unsignedp ? sat_short_accum_type_node : short_accum_type_node;
2958       if (mode == TYPE_MODE (accum_type_node))
2959         return unsignedp ? sat_accum_type_node : accum_type_node;
2960       if (mode == TYPE_MODE (long_accum_type_node))
2961         return unsignedp ? sat_long_accum_type_node : long_accum_type_node;
2962       if (mode == TYPE_MODE (long_long_accum_type_node))
2963         return unsignedp ? sat_long_long_accum_type_node
2964                          : long_long_accum_type_node;
2965
2966       if (mode == TYPE_MODE (unsigned_short_accum_type_node))
2967         return unsignedp ? sat_unsigned_short_accum_type_node
2968                          : unsigned_short_accum_type_node;
2969       if (mode == TYPE_MODE (unsigned_accum_type_node))
2970         return unsignedp ? sat_unsigned_accum_type_node
2971                          : unsigned_accum_type_node;
2972       if (mode == TYPE_MODE (unsigned_long_accum_type_node))
2973         return unsignedp ? sat_unsigned_long_accum_type_node
2974                          : unsigned_long_accum_type_node;
2975       if (mode == TYPE_MODE (unsigned_long_long_accum_type_node))
2976         return unsignedp ? sat_unsigned_long_long_accum_type_node
2977                          : unsigned_long_long_accum_type_node;
2978
2979       if (mode == QQmode)
2980         return unsignedp ? sat_qq_type_node : qq_type_node;
2981       if (mode == HQmode)
2982         return unsignedp ? sat_hq_type_node : hq_type_node;
2983       if (mode == SQmode)
2984         return unsignedp ? sat_sq_type_node : sq_type_node;
2985       if (mode == DQmode)
2986         return unsignedp ? sat_dq_type_node : dq_type_node;
2987       if (mode == TQmode)
2988         return unsignedp ? sat_tq_type_node : tq_type_node;
2989
2990       if (mode == UQQmode)
2991         return unsignedp ? sat_uqq_type_node : uqq_type_node;
2992       if (mode == UHQmode)
2993         return unsignedp ? sat_uhq_type_node : uhq_type_node;
2994       if (mode == USQmode)
2995         return unsignedp ? sat_usq_type_node : usq_type_node;
2996       if (mode == UDQmode)
2997         return unsignedp ? sat_udq_type_node : udq_type_node;
2998       if (mode == UTQmode)
2999         return unsignedp ? sat_utq_type_node : utq_type_node;
3000
3001       if (mode == HAmode)
3002         return unsignedp ? sat_ha_type_node : ha_type_node;
3003       if (mode == SAmode)
3004         return unsignedp ? sat_sa_type_node : sa_type_node;
3005       if (mode == DAmode)
3006         return unsignedp ? sat_da_type_node : da_type_node;
3007       if (mode == TAmode)
3008         return unsignedp ? sat_ta_type_node : ta_type_node;
3009
3010       if (mode == UHAmode)
3011         return unsignedp ? sat_uha_type_node : uha_type_node;
3012       if (mode == USAmode)
3013         return unsignedp ? sat_usa_type_node : usa_type_node;
3014       if (mode == UDAmode)
3015         return unsignedp ? sat_uda_type_node : uda_type_node;
3016       if (mode == UTAmode)
3017         return unsignedp ? sat_uta_type_node : uta_type_node;
3018     }
3019
3020   for (t = registered_builtin_types; t; t = TREE_CHAIN (t))
3021     if (TYPE_MODE (TREE_VALUE (t)) == mode)
3022       return TREE_VALUE (t);
3023
3024   return 0;
3025 }
3026
3027 tree
3028 c_common_unsigned_type (tree type)
3029 {
3030   return c_common_signed_or_unsigned_type (1, type);
3031 }
3032
3033 /* Return a signed type the same as TYPE in other respects.  */
3034
3035 tree
3036 c_common_signed_type (tree type)
3037 {
3038   return c_common_signed_or_unsigned_type (0, type);
3039 }
3040
3041 /* Return a type the same as TYPE except unsigned or
3042    signed according to UNSIGNEDP.  */
3043
3044 tree
3045 c_common_signed_or_unsigned_type (int unsignedp, tree type)
3046 {
3047   tree type1;
3048
3049   /* This block of code emulates the behavior of the old
3050      c_common_unsigned_type. In particular, it returns
3051      long_unsigned_type_node if passed a long, even when a int would
3052      have the same size. This is necessary for warnings to work
3053      correctly in archs where sizeof(int) == sizeof(long) */
3054
3055   type1 = TYPE_MAIN_VARIANT (type);
3056   if (type1 == signed_char_type_node || type1 == char_type_node || type1 == unsigned_char_type_node)
3057     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3058   if (type1 == integer_type_node || type1 == unsigned_type_node)
3059     return unsignedp ? unsigned_type_node : integer_type_node;
3060   if (type1 == short_integer_type_node || type1 == short_unsigned_type_node)
3061     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3062   if (type1 == long_integer_type_node || type1 == long_unsigned_type_node)
3063     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3064   if (type1 == long_long_integer_type_node || type1 == long_long_unsigned_type_node)
3065     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
3066   if (type1 == widest_integer_literal_type_node || type1 == widest_unsigned_literal_type_node)
3067     return unsignedp ? widest_unsigned_literal_type_node : widest_integer_literal_type_node;
3068 #if HOST_BITS_PER_WIDE_INT >= 64
3069   if (type1 == intTI_type_node || type1 == unsigned_intTI_type_node)
3070     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
3071 #endif
3072   if (type1 == intDI_type_node || type1 == unsigned_intDI_type_node)
3073     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
3074   if (type1 == intSI_type_node || type1 == unsigned_intSI_type_node)
3075     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
3076   if (type1 == intHI_type_node || type1 == unsigned_intHI_type_node)
3077     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
3078   if (type1 == intQI_type_node || type1 == unsigned_intQI_type_node)
3079     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
3080
3081 #define C_COMMON_FIXED_TYPES(NAME)          \
3082   if (type1 == short_ ## NAME ## _type_node \
3083       || type1 == unsigned_short_ ## NAME ## _type_node) \
3084     return unsignedp ? unsigned_short_ ## NAME ## _type_node \
3085                      : short_ ## NAME ## _type_node; \
3086   if (type1 == NAME ## _type_node \
3087       || type1 == unsigned_ ## NAME ## _type_node) \
3088     return unsignedp ? unsigned_ ## NAME ## _type_node \
3089                      : NAME ## _type_node; \
3090   if (type1 == long_ ## NAME ## _type_node \
3091       || type1 == unsigned_long_ ## NAME ## _type_node) \
3092     return unsignedp ? unsigned_long_ ## NAME ## _type_node \
3093                      : long_ ## NAME ## _type_node; \
3094   if (type1 == long_long_ ## NAME ## _type_node \
3095       || type1 == unsigned_long_long_ ## NAME ## _type_node) \
3096     return unsignedp ? unsigned_long_long_ ## NAME ## _type_node \
3097                      : long_long_ ## NAME ## _type_node;
3098
3099 #define C_COMMON_FIXED_MODE_TYPES(NAME) \
3100   if (type1 == NAME ## _type_node \
3101       || type1 == u ## NAME ## _type_node) \
3102     return unsignedp ? u ## NAME ## _type_node \
3103                      : NAME ## _type_node;
3104
3105 #define C_COMMON_FIXED_TYPES_SAT(NAME) \
3106   if (type1 == sat_ ## short_ ## NAME ## _type_node \
3107       || type1 == sat_ ## unsigned_short_ ## NAME ## _type_node) \
3108     return unsignedp ? sat_ ## unsigned_short_ ## NAME ## _type_node \
3109                      : sat_ ## short_ ## NAME ## _type_node; \
3110   if (type1 == sat_ ## NAME ## _type_node \
3111       || type1 == sat_ ## unsigned_ ## NAME ## _type_node) \
3112     return unsignedp ? sat_ ## unsigned_ ## NAME ## _type_node \
3113                      : sat_ ## NAME ## _type_node; \
3114   if (type1 == sat_ ## long_ ## NAME ## _type_node \
3115       || type1 == sat_ ## unsigned_long_ ## NAME ## _type_node) \
3116     return unsignedp ? sat_ ## unsigned_long_ ## NAME ## _type_node \
3117                      : sat_ ## long_ ## NAME ## _type_node; \
3118   if (type1 == sat_ ## long_long_ ## NAME ## _type_node \
3119       || type1 == sat_ ## unsigned_long_long_ ## NAME ## _type_node) \
3120     return unsignedp ? sat_ ## unsigned_long_long_ ## NAME ## _type_node \
3121                      : sat_ ## long_long_ ## NAME ## _type_node;
3122
3123 #define C_COMMON_FIXED_MODE_TYPES_SAT(NAME)     \
3124   if (type1 == sat_ ## NAME ## _type_node \
3125       || type1 == sat_ ## u ## NAME ## _type_node) \
3126     return unsignedp ? sat_ ## u ## NAME ## _type_node \
3127                      : sat_ ## NAME ## _type_node;
3128
3129   C_COMMON_FIXED_TYPES (fract);
3130   C_COMMON_FIXED_TYPES_SAT (fract);
3131   C_COMMON_FIXED_TYPES (accum);
3132   C_COMMON_FIXED_TYPES_SAT (accum);
3133
3134   C_COMMON_FIXED_MODE_TYPES (qq);
3135   C_COMMON_FIXED_MODE_TYPES (hq);
3136   C_COMMON_FIXED_MODE_TYPES (sq);
3137   C_COMMON_FIXED_MODE_TYPES (dq);
3138   C_COMMON_FIXED_MODE_TYPES (tq);
3139   C_COMMON_FIXED_MODE_TYPES_SAT (qq);
3140   C_COMMON_FIXED_MODE_TYPES_SAT (hq);
3141   C_COMMON_FIXED_MODE_TYPES_SAT (sq);
3142   C_COMMON_FIXED_MODE_TYPES_SAT (dq);
3143   C_COMMON_FIXED_MODE_TYPES_SAT (tq);
3144   C_COMMON_FIXED_MODE_TYPES (ha);
3145   C_COMMON_FIXED_MODE_TYPES (sa);
3146   C_COMMON_FIXED_MODE_TYPES (da);
3147   C_COMMON_FIXED_MODE_TYPES (ta);
3148   C_COMMON_FIXED_MODE_TYPES_SAT (ha);
3149   C_COMMON_FIXED_MODE_TYPES_SAT (sa);
3150   C_COMMON_FIXED_MODE_TYPES_SAT (da);
3151   C_COMMON_FIXED_MODE_TYPES_SAT (ta);
3152
3153   /* For ENUMERAL_TYPEs in C++, must check the mode of the types, not
3154      the precision; they have precision set to match their range, but
3155      may use a wider mode to match an ABI.  If we change modes, we may
3156      wind up with bad conversions.  For INTEGER_TYPEs in C, must check
3157      the precision as well, so as to yield correct results for
3158      bit-field types.  C++ does not have these separate bit-field
3159      types, and producing a signed or unsigned variant of an
3160      ENUMERAL_TYPE may cause other problems as well.  */
3161
3162   if (!INTEGRAL_TYPE_P (type)
3163       || TYPE_UNSIGNED (type) == unsignedp)
3164     return type;
3165
3166 #define TYPE_OK(node)                                                       \
3167   (TYPE_MODE (type) == TYPE_MODE (node)                                     \
3168    && TYPE_PRECISION (type) == TYPE_PRECISION (node))
3169   if (TYPE_OK (signed_char_type_node))
3170     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3171   if (TYPE_OK (integer_type_node))
3172     return unsignedp ? unsigned_type_node : integer_type_node;
3173   if (TYPE_OK (short_integer_type_node))
3174     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3175   if (TYPE_OK (long_integer_type_node))
3176     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3177   if (TYPE_OK (long_long_integer_type_node))
3178     return (unsignedp ? long_long_unsigned_type_node
3179             : long_long_integer_type_node);
3180   if (TYPE_OK (widest_integer_literal_type_node))
3181     return (unsignedp ? widest_unsigned_literal_type_node
3182             : widest_integer_literal_type_node);
3183
3184 #if HOST_BITS_PER_WIDE_INT >= 64
3185   if (TYPE_OK (intTI_type_node))
3186     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
3187 #endif
3188   if (TYPE_OK (intDI_type_node))
3189     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
3190   if (TYPE_OK (intSI_type_node))
3191     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
3192   if (TYPE_OK (intHI_type_node))
3193     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
3194   if (TYPE_OK (intQI_type_node))
3195     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
3196 #undef TYPE_OK
3197
3198   return build_nonstandard_integer_type (TYPE_PRECISION (type), unsignedp);
3199 }
3200
3201 /* Build a bit-field integer type for the given WIDTH and UNSIGNEDP.  */
3202
3203 tree
3204 c_build_bitfield_integer_type (unsigned HOST_WIDE_INT width, int unsignedp)
3205 {
3206   /* Extended integer types of the same width as a standard type have
3207      lesser rank, so those of the same width as int promote to int or
3208      unsigned int and are valid for printf formats expecting int or
3209      unsigned int.  To avoid such special cases, avoid creating
3210      extended integer types for bit-fields if a standard integer type
3211      is available.  */
3212   if (width == TYPE_PRECISION (integer_type_node))
3213     return unsignedp ? unsigned_type_node : integer_type_node;
3214   if (width == TYPE_PRECISION (signed_char_type_node))
3215     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3216   if (width == TYPE_PRECISION (short_integer_type_node))
3217     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3218   if (width == TYPE_PRECISION (long_integer_type_node))
3219     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3220   if (width == TYPE_PRECISION (long_long_integer_type_node))
3221     return (unsignedp ? long_long_unsigned_type_node
3222             : long_long_integer_type_node);
3223   return build_nonstandard_integer_type (width, unsignedp);
3224 }
3225
3226 /* The C version of the register_builtin_type langhook.  */
3227
3228 void
3229 c_register_builtin_type (tree type, const char* name)
3230 {
3231   tree decl;
3232
3233   decl = build_decl (UNKNOWN_LOCATION,
3234                      TYPE_DECL, get_identifier (name), type);
3235   DECL_ARTIFICIAL (decl) = 1;
3236   if (!TYPE_NAME (type))
3237     TYPE_NAME (type) = decl;
3238   pushdecl (decl);
3239
3240   registered_builtin_types = tree_cons (0, type, registered_builtin_types);
3241 }
3242 \f
3243 /* Print an error message for invalid operands to arith operation
3244    CODE with TYPE0 for operand 0, and TYPE1 for operand 1.
3245    LOCATION is the location of the message.  */
3246
3247 void
3248 binary_op_error (location_t location, enum tree_code code,
3249                  tree type0, tree type1)
3250 {
3251   const char *opname;
3252
3253   switch (code)
3254     {
3255     case PLUS_EXPR:
3256       opname = "+"; break;
3257     case MINUS_EXPR:
3258       opname = "-"; break;
3259     case MULT_EXPR:
3260       opname = "*"; break;
3261     case MAX_EXPR:
3262       opname = "max"; break;
3263     case MIN_EXPR:
3264       opname = "min"; break;
3265     case EQ_EXPR:
3266       opname = "=="; break;
3267     case NE_EXPR:
3268       opname = "!="; break;
3269     case LE_EXPR:
3270       opname = "<="; break;
3271     case GE_EXPR:
3272       opname = ">="; break;
3273     case LT_EXPR:
3274       opname = "<"; break;
3275     case GT_EXPR:
3276       opname = ">"; break;
3277     case LSHIFT_EXPR:
3278       opname = "<<"; break;
3279     case RSHIFT_EXPR:
3280       opname = ">>"; break;
3281     case TRUNC_MOD_EXPR:
3282     case FLOOR_MOD_EXPR:
3283       opname = "%"; break;
3284     case TRUNC_DIV_EXPR:
3285     case FLOOR_DIV_EXPR:
3286       opname = "/"; break;
3287     case BIT_AND_EXPR:
3288       opname = "&"; break;
3289     case BIT_IOR_EXPR:
3290       opname = "|"; break;
3291     case TRUTH_ANDIF_EXPR:
3292       opname = "&&"; break;
3293     case TRUTH_ORIF_EXPR:
3294       opname = "||"; break;
3295     case BIT_XOR_EXPR:
3296       opname = "^"; break;
3297     default:
3298       gcc_unreachable ();
3299     }
3300   error_at (location,
3301             "invalid operands to binary %s (have %qT and %qT)", opname,
3302             type0, type1);
3303 }
3304 \f
3305 /* Subroutine of build_binary_op, used for comparison operations.
3306    See if the operands have both been converted from subword integer types
3307    and, if so, perhaps change them both back to their original type.
3308    This function is also responsible for converting the two operands
3309    to the proper common type for comparison.
3310
3311    The arguments of this function are all pointers to local variables
3312    of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
3313    RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.
3314
3315    If this function returns nonzero, it means that the comparison has
3316    a constant value.  What this function returns is an expression for
3317    that value.  */
3318
3319 tree
3320 shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr,
3321                  enum tree_code *rescode_ptr)
3322 {
3323   tree type;
3324   tree op0 = *op0_ptr;
3325   tree op1 = *op1_ptr;
3326   int unsignedp0, unsignedp1;
3327   int real1, real2;
3328   tree primop0, primop1;
3329   enum tree_code code = *rescode_ptr;
3330
3331   /* Throw away any conversions to wider types
3332      already present in the operands.  */
3333
3334   primop0 = get_narrower (op0, &unsignedp0);
3335   primop1 = get_narrower (op1, &unsignedp1);
3336
3337   /* Handle the case that OP0 does not *contain* a conversion
3338      but it *requires* conversion to FINAL_TYPE.  */
3339
3340   if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
3341     unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3342   if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
3343     unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3344
3345   /* If one of the operands must be floated, we cannot optimize.  */
3346   real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
3347   real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
3348
3349   /* If first arg is constant, swap the args (changing operation
3350      so value is preserved), for canonicalization.  Don't do this if
3351      the second arg is 0.  */
3352
3353   if (TREE_CONSTANT (primop0)
3354       && !integer_zerop (primop1) && !real_zerop (primop1)
3355       && !fixed_zerop (primop1))
3356     {
3357       tree tem = primop0;
3358       int temi = unsignedp0;
3359       primop0 = primop1;
3360       primop1 = tem;
3361       tem = op0;
3362       op0 = op1;
3363       op1 = tem;
3364       *op0_ptr = op0;
3365       *op1_ptr = op1;
3366       unsignedp0 = unsignedp1;
3367       unsignedp1 = temi;
3368       temi = real1;
3369       real1 = real2;
3370       real2 = temi;
3371
3372       switch (code)
3373         {
3374         case LT_EXPR:
3375           code = GT_EXPR;
3376           break;
3377         case GT_EXPR:
3378           code = LT_EXPR;
3379           break;
3380         case LE_EXPR:
3381           code = GE_EXPR;
3382           break;
3383         case GE_EXPR:
3384           code = LE_EXPR;
3385           break;
3386         default:
3387           break;
3388         }
3389       *rescode_ptr = code;
3390     }
3391
3392   /* If comparing an integer against a constant more bits wide,
3393      maybe we can deduce a value of 1 or 0 independent of the data.
3394      Or else truncate the constant now
3395      rather than extend the variable at run time.
3396
3397      This is only interesting if the constant is the wider arg.
3398      Also, it is not safe if the constant is unsigned and the
3399      variable arg is signed, since in this case the variable
3400      would be sign-extended and then regarded as unsigned.
3401      Our technique fails in this case because the lowest/highest
3402      possible unsigned results don't follow naturally from the
3403      lowest/highest possible values of the variable operand.
3404      For just EQ_EXPR and NE_EXPR there is another technique that
3405      could be used: see if the constant can be faithfully represented
3406      in the other operand's type, by truncating it and reextending it
3407      and see if that preserves the constant's value.  */
3408
3409   if (!real1 && !real2
3410       && TREE_CODE (TREE_TYPE (primop0)) != FIXED_POINT_TYPE
3411       && TREE_CODE (primop1) == INTEGER_CST
3412       && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
3413     {
3414       int min_gt, max_gt, min_lt, max_lt;
3415       tree maxval, minval;
3416       /* 1 if comparison is nominally unsigned.  */
3417       int unsignedp = TYPE_UNSIGNED (*restype_ptr);
3418       tree val;
3419
3420       type = c_common_signed_or_unsigned_type (unsignedp0,
3421                                                TREE_TYPE (primop0));
3422
3423       maxval = TYPE_MAX_VALUE (type);
3424       minval = TYPE_MIN_VALUE (type);
3425
3426       if (unsignedp && !unsignedp0)
3427         *restype_ptr = c_common_signed_type (*restype_ptr);
3428
3429       if (TREE_TYPE (primop1) != *restype_ptr)
3430         {
3431           /* Convert primop1 to target type, but do not introduce
3432              additional overflow.  We know primop1 is an int_cst.  */
3433           primop1 = force_fit_type_double (*restype_ptr,
3434                                            TREE_INT_CST_LOW (primop1),
3435                                            TREE_INT_CST_HIGH (primop1), 0,
3436                                            TREE_OVERFLOW (primop1));
3437         }
3438       if (type != *restype_ptr)
3439         {
3440           minval = convert (*restype_ptr, minval);
3441           maxval = convert (*restype_ptr, maxval);
3442         }
3443
3444       if (unsignedp && unsignedp0)
3445         {
3446           min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
3447           max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
3448           min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
3449           max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
3450         }
3451       else
3452         {
3453           min_gt = INT_CST_LT (primop1, minval);
3454           max_gt = INT_CST_LT (primop1, maxval);
3455           min_lt = INT_CST_LT (minval, primop1);
3456           max_lt = INT_CST_LT (maxval, primop1);
3457         }
3458
3459       val = 0;
3460       /* This used to be a switch, but Genix compiler can't handle that.  */
3461       if (code == NE_EXPR)
3462         {
3463           if (max_lt || min_gt)
3464             val = truthvalue_true_node;
3465         }
3466       else if (code == EQ_EXPR)
3467         {
3468           if (max_lt || min_gt)
3469             val = truthvalue_false_node;
3470         }
3471       else if (code == LT_EXPR)
3472         {
3473           if (max_lt)
3474             val = truthvalue_true_node;
3475           if (!min_lt)
3476             val = truthvalue_false_node;
3477         }
3478       else if (code == GT_EXPR)
3479         {
3480           if (min_gt)
3481             val = truthvalue_true_node;
3482           if (!max_gt)
3483             val = truthvalue_false_node;
3484         }
3485       else if (code == LE_EXPR)
3486         {
3487           if (!max_gt)
3488             val = truthvalue_true_node;
3489           if (min_gt)
3490             val = truthvalue_false_node;
3491         }
3492       else if (code == GE_EXPR)
3493         {
3494           if (!min_lt)
3495             val = truthvalue_true_node;
3496           if (max_lt)
3497             val = truthvalue_false_node;
3498         }
3499
3500       /* If primop0 was sign-extended and unsigned comparison specd,
3501          we did a signed comparison above using the signed type bounds.
3502          But the comparison we output must be unsigned.
3503
3504          Also, for inequalities, VAL is no good; but if the signed
3505          comparison had *any* fixed result, it follows that the
3506          unsigned comparison just tests the sign in reverse
3507          (positive values are LE, negative ones GE).
3508          So we can generate an unsigned comparison
3509          against an extreme value of the signed type.  */
3510
3511       if (unsignedp && !unsignedp0)
3512         {
3513           if (val != 0)
3514             switch (code)
3515               {
3516               case LT_EXPR:
3517               case GE_EXPR:
3518                 primop1 = TYPE_MIN_VALUE (type);
3519                 val = 0;
3520                 break;
3521
3522               case LE_EXPR:
3523               case GT_EXPR:
3524                 primop1 = TYPE_MAX_VALUE (type);
3525                 val = 0;
3526                 break;
3527
3528               default:
3529                 break;
3530               }
3531           type = c_common_unsigned_type (type);
3532         }
3533
3534       if (TREE_CODE (primop0) != INTEGER_CST)
3535         {
3536           if (val == truthvalue_false_node)
3537             warning (OPT_Wtype_limits, "comparison is always false due to limited range of data type");
3538           if (val == truthvalue_true_node)
3539             warning (OPT_Wtype_limits, "comparison is always true due to limited range of data type");
3540         }
3541
3542       if (val != 0)
3543         {
3544           /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
3545           if (TREE_SIDE_EFFECTS (primop0))
3546             return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
3547           return val;
3548         }
3549
3550       /* Value is not predetermined, but do the comparison
3551          in the type of the operand that is not constant.
3552          TYPE is already properly set.  */
3553     }
3554
3555   /* If either arg is decimal float and the other is float, find the
3556      proper common type to use for comparison.  */
3557   else if (real1 && real2
3558            && (DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop0)))
3559                || DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop1)))))
3560     type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
3561
3562   else if (real1 && real2
3563            && (TYPE_PRECISION (TREE_TYPE (primop0))
3564                == TYPE_PRECISION (TREE_TYPE (primop1))))
3565     type = TREE_TYPE (primop0);
3566
3567   /* If args' natural types are both narrower than nominal type
3568      and both extend in the same manner, compare them
3569      in the type of the wider arg.
3570      Otherwise must actually extend both to the nominal
3571      common type lest different ways of extending
3572      alter the result.
3573      (eg, (short)-1 == (unsigned short)-1  should be 0.)  */
3574
3575   else if (unsignedp0 == unsignedp1 && real1 == real2
3576            && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
3577            && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
3578     {
3579       type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
3580       type = c_common_signed_or_unsigned_type (unsignedp0
3581                                                || TYPE_UNSIGNED (*restype_ptr),
3582                                                type);
3583       /* Make sure shorter operand is extended the right way
3584          to match the longer operand.  */
3585       primop0
3586         = convert (c_common_signed_or_unsigned_type (unsignedp0,
3587                                                      TREE_TYPE (primop0)),
3588                    primop0);
3589       primop1
3590         = convert (c_common_signed_or_unsigned_type (unsignedp1,
3591                                                      TREE_TYPE (primop1)),
3592                    primop1);
3593     }
3594   else
3595     {
3596       /* Here we must do the comparison on the nominal type
3597          using the args exactly as we received them.  */
3598       type = *restype_ptr;
3599       primop0 = op0;
3600       primop1 = op1;
3601
3602       if (!real1 && !real2 && integer_zerop (primop1)
3603           && TYPE_UNSIGNED (*restype_ptr))
3604         {
3605           tree value = 0;
3606           switch (code)
3607             {
3608             case GE_EXPR:
3609               /* All unsigned values are >= 0, so we warn.  However,
3610                  if OP0 is a constant that is >= 0, the signedness of
3611                  the comparison isn't an issue, so suppress the
3612                  warning.  */
3613               if (warn_type_limits && !in_system_header
3614                   && !(TREE_CODE (primop0) == INTEGER_CST
3615                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
3616                                                    primop0))))
3617                 warning (OPT_Wtype_limits,
3618                          "comparison of unsigned expression >= 0 is always true");
3619               value = truthvalue_true_node;
3620               break;
3621
3622             case LT_EXPR:
3623               if (warn_type_limits && !in_system_header
3624                   && !(TREE_CODE (primop0) == INTEGER_CST
3625                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
3626                                                    primop0))))
3627                 warning (OPT_Wtype_limits,
3628                          "comparison of unsigned expression < 0 is always false");
3629               value = truthvalue_false_node;
3630               break;
3631
3632             default:
3633               break;
3634             }
3635
3636           if (value != 0)
3637             {
3638               /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
3639               if (TREE_SIDE_EFFECTS (primop0))
3640                 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
3641                                primop0, value);
3642               return value;
3643             }
3644         }
3645     }
3646
3647   *op0_ptr = convert (type, primop0);
3648   *op1_ptr = convert (type, primop1);
3649
3650   *restype_ptr = truthvalue_type_node;
3651
3652   return 0;
3653 }
3654 \f
3655 /* Return a tree for the sum or difference (RESULTCODE says which)
3656    of pointer PTROP and integer INTOP.  */
3657
3658 tree
3659 pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3660 {
3661   tree size_exp, ret;
3662
3663   /* The result is a pointer of the same type that is being added.  */
3664   tree result_type = TREE_TYPE (ptrop);
3665
3666   if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
3667     {
3668       pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3669                "pointer of type %<void *%> used in arithmetic");
3670       size_exp = integer_one_node;
3671     }
3672   else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE)
3673     {
3674       pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3675                "pointer to a function used in arithmetic");
3676       size_exp = integer_one_node;
3677     }
3678   else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE)
3679     {
3680       pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3681                "pointer to member function used in arithmetic");
3682       size_exp = integer_one_node;
3683     }
3684   else
3685     size_exp = size_in_bytes (TREE_TYPE (result_type));
3686
3687   /* We are manipulating pointer values, so we don't need to warn
3688      about relying on undefined signed overflow.  We disable the
3689      warning here because we use integer types so fold won't know that
3690      they are really pointers.  */
3691   fold_defer_overflow_warnings ();
3692
3693   /* If what we are about to multiply by the size of the elements
3694      contains a constant term, apply distributive law
3695      and multiply that constant term separately.
3696      This helps produce common subexpressions.  */
3697   if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
3698       && !TREE_CONSTANT (intop)
3699       && TREE_CONSTANT (TREE_OPERAND (intop, 1))
3700       && TREE_CONSTANT (size_exp)
3701       /* If the constant comes from pointer subtraction,
3702          skip this optimization--it would cause an error.  */
3703       && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
3704       /* If the constant is unsigned, and smaller than the pointer size,
3705          then we must skip this optimization.  This is because it could cause
3706          an overflow error if the constant is negative but INTOP is not.  */
3707       && (!TYPE_UNSIGNED (TREE_TYPE (intop))
3708           || (TYPE_PRECISION (TREE_TYPE (intop))
3709               == TYPE_PRECISION (TREE_TYPE (ptrop)))))
3710     {
3711       enum tree_code subcode = resultcode;
3712       tree int_type = TREE_TYPE (intop);
3713       if (TREE_CODE (intop) == MINUS_EXPR)
3714         subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
3715       /* Convert both subexpression types to the type of intop,
3716          because weird cases involving pointer arithmetic
3717          can result in a sum or difference with different type args.  */
3718       ptrop = build_binary_op (EXPR_LOCATION (TREE_OPERAND (intop, 1)),
3719                                subcode, ptrop,
3720                                convert (int_type, TREE_OPERAND (intop, 1)), 1);
3721       intop = convert (int_type, TREE_OPERAND (intop, 0));
3722     }
3723
3724   /* Convert the integer argument to a type the same size as sizetype
3725      so the multiply won't overflow spuriously.  */
3726   if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype)
3727       || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype))
3728     intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype),
3729                                              TYPE_UNSIGNED (sizetype)), intop);
3730
3731   /* Replace the integer argument with a suitable product by the object size.
3732      Do this multiplication as signed, then convert to the appropriate
3733      type for the pointer operation.  */
3734   intop = convert (sizetype,
3735                    build_binary_op (EXPR_LOCATION (intop),
3736                                     MULT_EXPR, intop,
3737                                     convert (TREE_TYPE (intop), size_exp), 1));
3738
3739   /* Create the sum or difference.  */
3740   if (resultcode == MINUS_EXPR)
3741     intop = fold_build1 (NEGATE_EXPR, sizetype, intop);
3742
3743   ret = fold_build2 (POINTER_PLUS_EXPR, result_type, ptrop, intop);
3744
3745   fold_undefer_and_ignore_overflow_warnings ();
3746
3747   return ret;
3748 }
3749 \f
3750 /* Wrap a SAVE_EXPR around EXPR, if appropriate.  Like save_expr, but
3751    for C folds the inside expression and wraps a C_MAYBE_CONST_EXPR
3752    around the SAVE_EXPR if needed so that c_fully_fold does not need
3753    to look inside SAVE_EXPRs.  */
3754
3755 tree
3756 c_save_expr (tree expr)
3757 {
3758   bool maybe_const = true;
3759   if (c_dialect_cxx ())
3760     return save_expr (expr);
3761   expr = c_fully_fold (expr, false, &maybe_const);
3762   expr = save_expr (expr);
3763   if (!maybe_const)
3764     {
3765       expr = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (expr), NULL, expr);
3766       C_MAYBE_CONST_EXPR_NON_CONST (expr) = 1;
3767     }
3768   return expr;
3769 }
3770
3771 /* Return whether EXPR is a declaration whose address can never be
3772    NULL.  */
3773
3774 bool
3775 decl_with_nonnull_addr_p (const_tree expr)
3776 {
3777   return (DECL_P (expr)
3778           && (TREE_CODE (expr) == PARM_DECL
3779               || TREE_CODE (expr) == LABEL_DECL
3780               || !DECL_WEAK (expr)));
3781 }
3782
3783 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
3784    or for an `if' or `while' statement or ?..: exp.  It should already
3785    have been validated to be of suitable type; otherwise, a bad
3786    diagnostic may result.
3787
3788    The EXPR is located at LOCATION.
3789
3790    This preparation consists of taking the ordinary
3791    representation of an expression expr and producing a valid tree
3792    boolean expression describing whether expr is nonzero.  We could
3793    simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1),
3794    but we optimize comparisons, &&, ||, and !.
3795
3796    The resulting type should always be `truthvalue_type_node'.  */
3797
3798 tree
3799 c_common_truthvalue_conversion (location_t location, tree expr)
3800 {
3801   switch (TREE_CODE (expr))
3802     {
3803     case EQ_EXPR:   case NE_EXPR:   case UNEQ_EXPR: case LTGT_EXPR:
3804     case LE_EXPR:   case GE_EXPR:   case LT_EXPR:   case GT_EXPR:
3805     case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR:
3806     case ORDERED_EXPR: case UNORDERED_EXPR:
3807       if (TREE_TYPE (expr) == truthvalue_type_node)
3808         return expr;
3809       expr = build2 (TREE_CODE (expr), truthvalue_type_node,
3810                      TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1));
3811       goto ret;
3812
3813     case TRUTH_ANDIF_EXPR:
3814     case TRUTH_ORIF_EXPR:
3815     case TRUTH_AND_EXPR:
3816     case TRUTH_OR_EXPR:
3817     case TRUTH_XOR_EXPR:
3818       if (TREE_TYPE (expr) == truthvalue_type_node)
3819         return expr;
3820       expr = build2 (TREE_CODE (expr), truthvalue_type_node,
3821                      c_common_truthvalue_conversion (location,
3822                                                      TREE_OPERAND (expr, 0)),
3823                      c_common_truthvalue_conversion (location,
3824                                                      TREE_OPERAND (expr, 1)));
3825       goto ret;
3826
3827     case TRUTH_NOT_EXPR:
3828       if (TREE_TYPE (expr) == truthvalue_type_node)
3829         return expr;
3830       expr = build1 (TREE_CODE (expr), truthvalue_type_node,
3831                      c_common_truthvalue_conversion (location,
3832                                                      TREE_OPERAND (expr, 0)));
3833       goto ret;
3834
3835     case ERROR_MARK:
3836       return expr;
3837
3838     case INTEGER_CST:
3839       return integer_zerop (expr) ? truthvalue_false_node
3840                                   : truthvalue_true_node;
3841
3842     case REAL_CST:
3843       return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0)
3844              ? truthvalue_true_node
3845              : truthvalue_false_node;
3846
3847     case FIXED_CST:
3848       return fixed_compare (NE_EXPR, &TREE_FIXED_CST (expr),
3849                             &FCONST0 (TYPE_MODE (TREE_TYPE (expr))))
3850              ? truthvalue_true_node
3851              : truthvalue_false_node;
3852
3853     case FUNCTION_DECL:
3854       expr = build_unary_op (location, ADDR_EXPR, expr, 0);
3855       /* Fall through.  */
3856
3857     case ADDR_EXPR:
3858       {
3859         tree inner = TREE_OPERAND (expr, 0);
3860         if (decl_with_nonnull_addr_p (inner))
3861           {
3862             /* Common Ada/Pascal programmer's mistake.  */
3863             warning_at (location,
3864                         OPT_Waddress,
3865                         "the address of %qD will always evaluate as %<true%>",
3866                         inner);
3867             return truthvalue_true_node;
3868           }
3869
3870         /* If we still have a decl, it is possible for its address to
3871            be NULL, so we cannot optimize.  */
3872         if (DECL_P (inner))
3873           {
3874             gcc_assert (DECL_WEAK (inner));
3875             break;
3876           }
3877
3878         if (TREE_SIDE_EFFECTS (inner))
3879           {
3880             expr = build2 (COMPOUND_EXPR, truthvalue_type_node,
3881                            inner, truthvalue_true_node);
3882             goto ret;
3883           }
3884         else
3885           return truthvalue_true_node;
3886       }
3887
3888     case COMPLEX_EXPR:
3889       expr = build_binary_op (EXPR_LOCATION (expr),
3890                               (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
3891                                ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
3892                 c_common_truthvalue_conversion (location,
3893                                                 TREE_OPERAND (expr, 0)),
3894                 c_common_truthvalue_conversion (location,
3895                                                 TREE_OPERAND (expr, 1)),
3896                               0);
3897       goto ret;
3898
3899     case NEGATE_EXPR:
3900     case ABS_EXPR:
3901     case FLOAT_EXPR:
3902     case EXCESS_PRECISION_EXPR:
3903       /* These don't change whether an object is nonzero or zero.  */
3904       return c_common_truthvalue_conversion (location, TREE_OPERAND (expr, 0));
3905
3906     case LROTATE_EXPR:
3907     case RROTATE_EXPR:
3908       /* These don't change whether an object is zero or nonzero, but
3909          we can't ignore them if their second arg has side-effects.  */
3910       if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
3911         {
3912           expr = build2 (COMPOUND_EXPR, truthvalue_type_node,
3913                          TREE_OPERAND (expr, 1),
3914                          c_common_truthvalue_conversion
3915                          (location, TREE_OPERAND (expr, 0)));
3916           goto ret;
3917         }
3918       else
3919         return c_common_truthvalue_conversion (location,
3920                                                TREE_OPERAND (expr, 0));
3921
3922     case COND_EXPR:
3923       /* Distribute the conversion into the arms of a COND_EXPR.  */
3924       if (c_dialect_cxx ())
3925         {
3926           expr = fold_build3 (COND_EXPR, truthvalue_type_node,
3927                               TREE_OPERAND (expr, 0),
3928                               c_common_truthvalue_conversion (location,
3929                                                               TREE_OPERAND (expr,
3930                                                                             1)),
3931                               c_common_truthvalue_conversion (location,
3932                                                               TREE_OPERAND (expr,
3933                                                                             2)));
3934           goto ret;
3935         }
3936       else
3937         {
3938           /* Folding will happen later for C.  */
3939           expr = build3 (COND_EXPR, truthvalue_type_node,
3940                          TREE_OPERAND (expr, 0),
3941                          c_common_truthvalue_conversion (location,
3942                                                          TREE_OPERAND (expr, 1)),
3943                          c_common_truthvalue_conversion (location,
3944                                                          TREE_OPERAND (expr, 2)));
3945           goto ret;
3946         }
3947
3948     CASE_CONVERT:
3949       /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
3950          since that affects how `default_conversion' will behave.  */
3951       if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
3952           || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
3953         break;
3954       /* If this is widening the argument, we can ignore it.  */
3955       if (TYPE_PRECISION (TREE_TYPE (expr))
3956           >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
3957         return c_common_truthvalue_conversion (location,
3958                                                TREE_OPERAND (expr, 0));
3959       break;
3960
3961     case MODIFY_EXPR:
3962       if (!TREE_NO_WARNING (expr)
3963           && warn_parentheses)
3964         {
3965           warning (OPT_Wparentheses,
3966                    "suggest parentheses around assignment used as truth value");
3967           TREE_NO_WARNING (expr) = 1;
3968         }
3969       break;
3970
3971     default:
3972       break;
3973     }
3974
3975   if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
3976     {
3977       tree t = c_save_expr (expr);
3978       expr = (build_binary_op
3979               (EXPR_LOCATION (expr),
3980                (TREE_SIDE_EFFECTS (expr)
3981                 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
3982         c_common_truthvalue_conversion
3983                (location,
3984                 build_unary_op (location, REALPART_EXPR, t, 0)),
3985         c_common_truthvalue_conversion
3986                (location,
3987                 build_unary_op (location, IMAGPART_EXPR, t, 0)),
3988                0));
3989       goto ret;
3990     }
3991
3992   if (TREE_CODE (TREE_TYPE (expr)) == FIXED_POINT_TYPE)
3993     {
3994       tree fixed_zero_node = build_fixed (TREE_TYPE (expr),
3995                                           FCONST0 (TYPE_MODE
3996                                                    (TREE_TYPE (expr))));
3997       return build_binary_op (location, NE_EXPR, expr, fixed_zero_node, 1);
3998     }
3999   else
4000     return build_binary_op (location, NE_EXPR, expr, integer_zero_node, 1);
4001
4002  ret:
4003   protected_set_expr_location (expr, location);
4004   return expr;
4005 }
4006 \f
4007 static void def_builtin_1  (enum built_in_function fncode,
4008                             const char *name,
4009                             enum built_in_class fnclass,
4010                             tree fntype, tree libtype,
4011                             bool both_p, bool fallback_p, bool nonansi_p,
4012                             tree fnattrs, bool implicit_p);
4013
4014
4015 /* Apply the TYPE_QUALS to the new DECL.  */
4016
4017 void
4018 c_apply_type_quals_to_decl (int type_quals, tree decl)
4019 {
4020   tree type = TREE_TYPE (decl);
4021
4022   if (type == error_mark_node)
4023     return;
4024
4025   if (((type_quals & TYPE_QUAL_CONST)
4026        || (type && TREE_CODE (type) == REFERENCE_TYPE))
4027       /* An object declared 'const' is only readonly after it is
4028          initialized.  We don't have any way of expressing this currently,
4029          so we need to be conservative and unset TREE_READONLY for types
4030          with constructors.  Otherwise aliasing code will ignore stores in
4031          an inline constructor.  */
4032       && !(type && TYPE_NEEDS_CONSTRUCTING (type)))
4033     TREE_READONLY (decl) = 1;
4034   if (type_quals & TYPE_QUAL_VOLATILE)
4035     {
4036       TREE_SIDE_EFFECTS (decl) = 1;
4037       TREE_THIS_VOLATILE (decl) = 1;
4038     }
4039   if (type_quals & TYPE_QUAL_RESTRICT)
4040     {
4041       while (type && TREE_CODE (type) == ARRAY_TYPE)
4042         /* Allow 'restrict' on arrays of pointers.
4043            FIXME currently we just ignore it.  */
4044         type = TREE_TYPE (type);
4045       if (!type
4046           || !POINTER_TYPE_P (type)
4047           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))
4048         error ("invalid use of %<restrict%>");
4049       else if (flag_strict_aliasing && type == TREE_TYPE (decl))
4050         /* Indicate we need to make a unique alias set for this pointer.
4051            We can't do it here because it might be pointing to an
4052            incomplete type.  */
4053         DECL_POINTER_ALIAS_SET (decl) = -2;
4054     }
4055 }
4056
4057 /* Hash function for the problem of multiple type definitions in
4058    different files.  This must hash all types that will compare
4059    equal via comptypes to the same value.  In practice it hashes
4060    on some of the simple stuff and leaves the details to comptypes.  */
4061
4062 static hashval_t
4063 c_type_hash (const void *p)
4064 {
4065   int i = 0;
4066   int shift, size;
4067   const_tree const t = (const_tree) p;
4068   tree t2;
4069   switch (TREE_CODE (t))
4070     {
4071     /* For pointers, hash on pointee type plus some swizzling.  */
4072     case POINTER_TYPE:
4073       return c_type_hash (TREE_TYPE (t)) ^ 0x3003003;
4074     /* Hash on number of elements and total size.  */
4075     case ENUMERAL_TYPE:
4076       shift = 3;
4077       t2 = TYPE_VALUES (t);
4078       break;
4079     case RECORD_TYPE:
4080       shift = 0;
4081       t2 = TYPE_FIELDS (t);
4082       break;
4083     case QUAL_UNION_TYPE:
4084       shift = 1;
4085       t2 = TYPE_FIELDS (t);
4086       break;
4087     case UNION_TYPE:
4088       shift = 2;
4089       t2 = TYPE_FIELDS (t);
4090       break;
4091     default:
4092       gcc_unreachable ();
4093     }
4094   for (; t2; t2 = TREE_CHAIN (t2))
4095     i++;
4096   /* We might have a VLA here.  */
4097   if (TREE_CODE (TYPE_SIZE (t)) != INTEGER_CST)
4098     size = 0;
4099   else
4100     size = TREE_INT_CST_LOW (TYPE_SIZE (t));
4101   return ((size << 24) | (i << shift));
4102 }
4103
4104 static GTY((param_is (union tree_node))) htab_t type_hash_table;
4105
4106 /* Return the typed-based alias set for T, which may be an expression
4107    or a type.  Return -1 if we don't do anything special.  */
4108
4109 alias_set_type
4110 c_common_get_alias_set (tree t)
4111 {
4112   tree u;
4113   PTR *slot;
4114
4115   /* Permit type-punning when accessing a union, provided the access
4116      is directly through the union.  For example, this code does not
4117      permit taking the address of a union member and then storing
4118      through it.  Even the type-punning allowed here is a GCC
4119      extension, albeit a common and useful one; the C standard says
4120      that such accesses have implementation-defined behavior.  */
4121   for (u = t;
4122        TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
4123        u = TREE_OPERAND (u, 0))
4124     if (TREE_CODE (u) == COMPONENT_REF
4125         && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
4126       return 0;
4127
4128   /* That's all the expressions we handle specially.  */
4129   if (!TYPE_P (t))
4130     return -1;
4131
4132   /* The C standard guarantees that any object may be accessed via an
4133      lvalue that has character type.  */
4134   if (t == char_type_node
4135       || t == signed_char_type_node
4136       || t == unsigned_char_type_node)
4137     return 0;
4138
4139   /* The C standard specifically allows aliasing between signed and
4140      unsigned variants of the same type.  We treat the signed
4141      variant as canonical.  */
4142   if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t))
4143     {
4144       tree t1 = c_common_signed_type (t);
4145
4146       /* t1 == t can happen for boolean nodes which are always unsigned.  */
4147       if (t1 != t)
4148         return get_alias_set (t1);
4149     }
4150   else if (POINTER_TYPE_P (t))
4151     {
4152       tree t1;
4153
4154       /* Unfortunately, there is no canonical form of a pointer type.
4155          In particular, if we have `typedef int I', then `int *', and
4156          `I *' are different types.  So, we have to pick a canonical
4157          representative.  We do this below.
4158
4159          Technically, this approach is actually more conservative that
4160          it needs to be.  In particular, `const int *' and `int *'
4161          should be in different alias sets, according to the C and C++
4162          standard, since their types are not the same, and so,
4163          technically, an `int **' and `const int **' cannot point at
4164          the same thing.
4165
4166          But, the standard is wrong.  In particular, this code is
4167          legal C++:
4168
4169             int *ip;
4170             int **ipp = &ip;
4171             const int* const* cipp = ipp;
4172
4173          And, it doesn't make sense for that to be legal unless you
4174          can dereference IPP and CIPP.  So, we ignore cv-qualifiers on
4175          the pointed-to types.  This issue has been reported to the
4176          C++ committee.  */
4177       t1 = build_type_no_quals (t);
4178       if (t1 != t)
4179         return get_alias_set (t1);
4180     }
4181
4182   /* Handle the case of multiple type nodes referring to "the same" type,
4183      which occurs with IMA.  These share an alias set.  FIXME:  Currently only
4184      C90 is handled.  (In C99 type compatibility is not transitive, which
4185      complicates things mightily. The alias set splay trees can theoretically
4186      represent this, but insertion is tricky when you consider all the
4187      different orders things might arrive in.) */
4188
4189   if (c_language != clk_c || flag_isoc99)
4190     return -1;
4191
4192   /* Save time if there's only one input file.  */
4193   if (num_in_fnames == 1)
4194     return -1;
4195
4196   /* Pointers need special handling if they point to any type that
4197      needs special handling (below).  */
4198   if (TREE_CODE (t) == POINTER_TYPE)
4199     {
4200       tree t2;
4201       /* Find bottom type under any nested POINTERs.  */
4202       for (t2 = TREE_TYPE (t);
4203            TREE_CODE (t2) == POINTER_TYPE;
4204            t2 = TREE_TYPE (t2))
4205         ;
4206       if (TREE_CODE (t2) != RECORD_TYPE
4207           && TREE_CODE (t2) != ENUMERAL_TYPE
4208           && TREE_CODE (t2) != QUAL_UNION_TYPE
4209           && TREE_CODE (t2) != UNION_TYPE)
4210         return -1;
4211       if (TYPE_SIZE (t2) == 0)
4212         return -1;
4213     }
4214   /* These are the only cases that need special handling.  */
4215   if (TREE_CODE (t) != RECORD_TYPE
4216       && TREE_CODE (t) != ENUMERAL_TYPE
4217       && TREE_CODE (t) != QUAL_UNION_TYPE
4218       && TREE_CODE (t) != UNION_TYPE
4219       && TREE_CODE (t) != POINTER_TYPE)
4220     return -1;
4221   /* Undefined? */
4222   if (TYPE_SIZE (t) == 0)
4223     return -1;
4224
4225   /* Look up t in hash table.  Only one of the compatible types within each
4226      alias set is recorded in the table.  */
4227   if (!type_hash_table)
4228     type_hash_table = htab_create_ggc (1021, c_type_hash,
4229             (htab_eq) lang_hooks.types_compatible_p,
4230             NULL);
4231   slot = htab_find_slot (type_hash_table, t, INSERT);
4232   if (*slot != NULL)
4233     {
4234       TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot);
4235       return TYPE_ALIAS_SET ((tree)*slot);
4236     }
4237   else
4238     /* Our caller will assign and record (in t) a new alias set; all we need
4239        to do is remember t in the hash table.  */
4240     *slot = t;
4241
4242   return -1;
4243 }
4244 \f
4245 /* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where
4246    the second parameter indicates which OPERATOR is being applied.
4247    The COMPLAIN flag controls whether we should diagnose possibly
4248    ill-formed constructs or not.  LOC is the location of the SIZEOF or
4249    TYPEOF operator.  */
4250
4251 tree
4252 c_sizeof_or_alignof_type (location_t loc,
4253                           tree type, bool is_sizeof, int complain)
4254 {
4255   const char *op_name;
4256   tree value = NULL;
4257   enum tree_code type_code = TREE_CODE (type);
4258
4259   op_name = is_sizeof ? "sizeof" : "__alignof__";
4260
4261   if (type_code == FUNCTION_TYPE)
4262     {
4263       if (is_sizeof)
4264         {
4265           if (complain && (pedantic || warn_pointer_arith))
4266             pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
4267                      "invalid application of %<sizeof%> to a function type");
4268           else if (!complain)
4269             return error_mark_node;
4270           value = size_one_node;
4271         }
4272       else
4273         value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);
4274     }
4275   else if (type_code == VOID_TYPE || type_code == ERROR_MARK)
4276     {
4277       if (type_code == VOID_TYPE
4278           && complain && (pedantic || warn_pointer_arith))
4279         pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
4280                  "invalid application of %qs to a void type", op_name);
4281       else if (!complain)
4282         return error_mark_node;
4283       value = size_one_node;
4284     }
4285   else if (!COMPLETE_TYPE_P (type))
4286     {
4287       if (complain)
4288         error_at (loc, "invalid application of %qs to incomplete type %qT ",
4289                   op_name, type);
4290       value = size_zero_node;
4291     }
4292   else
4293     {
4294       if (is_sizeof)
4295         /* Convert in case a char is more than one unit.  */
4296         value = size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
4297                             size_int (TYPE_PRECISION (char_type_node)
4298                                       / BITS_PER_UNIT));
4299       else
4300         value = size_int (TYPE_ALIGN_UNIT (type));
4301     }
4302
4303   /* VALUE will have an integer type with TYPE_IS_SIZETYPE set.
4304      TYPE_IS_SIZETYPE means that certain things (like overflow) will
4305      never happen.  However, this node should really have type
4306      `size_t', which is just a typedef for an ordinary integer type.  */
4307   value = fold_convert (size_type_node, value);
4308   gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value)));
4309
4310   return value;
4311 }
4312
4313 /* Implement the __alignof keyword: Return the minimum required
4314    alignment of EXPR, measured in bytes.  For VAR_DECLs,
4315    FUNCTION_DECLs and FIELD_DECLs return DECL_ALIGN (which can be set
4316    from an "aligned" __attribute__ specification).  LOC is the
4317    location of the ALIGNOF operator.  */
4318
4319 tree
4320 c_alignof_expr (location_t loc, tree expr)
4321 {
4322   tree t;
4323
4324   if (VAR_OR_FUNCTION_DECL_P (expr))
4325     t = size_int (DECL_ALIGN_UNIT (expr));
4326
4327   else if (TREE_CODE (expr) == COMPONENT_REF
4328            && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1)))
4329     {
4330       error_at (loc, "%<__alignof%> applied to a bit-field");
4331       t = size_one_node;
4332     }
4333   else if (TREE_CODE (expr) == COMPONENT_REF
4334            && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL)
4335     t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1)));
4336
4337   else if (TREE_CODE (expr) == INDIRECT_REF)
4338     {
4339       tree t = TREE_OPERAND (expr, 0);
4340       tree best = t;
4341       int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
4342
4343       while (CONVERT_EXPR_P (t)
4344              && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE)
4345         {
4346           int thisalign;
4347
4348           t = TREE_OPERAND (t, 0);
4349           thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
4350           if (thisalign > bestalign)
4351             best = t, bestalign = thisalign;
4352         }
4353       return c_alignof (loc, TREE_TYPE (TREE_TYPE (best)));
4354     }
4355   else
4356     return c_alignof (loc, TREE_TYPE (expr));
4357
4358   return fold_convert (size_type_node, t);
4359 }
4360 \f
4361 /* Handle C and C++ default attributes.  */
4362
4363 enum built_in_attribute
4364 {
4365 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
4366 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
4367 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
4368 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
4369 #include "builtin-attrs.def"
4370 #undef DEF_ATTR_NULL_TREE
4371 #undef DEF_ATTR_INT
4372 #undef DEF_ATTR_IDENT
4373 #undef DEF_ATTR_TREE_LIST
4374   ATTR_LAST
4375 };
4376
4377 static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
4378
4379 static void c_init_attributes (void);
4380
4381 enum c_builtin_type
4382 {
4383 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
4384 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
4385 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
4386 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
4387 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
4388 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
4389 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
4390 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) NAME,
4391 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7) NAME,
4392 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
4393 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
4394 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
4395 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
4396 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
4397 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \
4398   NAME,
4399 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
4400 #include "builtin-types.def"
4401 #undef DEF_PRIMITIVE_TYPE
4402 #undef DEF_FUNCTION_TYPE_0
4403 #undef DEF_FUNCTION_TYPE_1
4404 #undef DEF_FUNCTION_TYPE_2
4405 #undef DEF_FUNCTION_TYPE_3
4406 #undef DEF_FUNCTION_TYPE_4
4407 #undef DEF_FUNCTION_TYPE_5
4408 #undef DEF_FUNCTION_TYPE_6
4409 #undef DEF_FUNCTION_TYPE_7
4410 #undef DEF_FUNCTION_TYPE_VAR_0
4411 #undef DEF_FUNCTION_TYPE_VAR_1
4412 #undef DEF_FUNCTION_TYPE_VAR_2
4413 #undef DEF_FUNCTION_TYPE_VAR_3
4414 #undef DEF_FUNCTION_TYPE_VAR_4
4415 #undef DEF_FUNCTION_TYPE_VAR_5
4416 #undef DEF_POINTER_TYPE
4417   BT_LAST
4418 };
4419
4420 typedef enum c_builtin_type builtin_type;
4421
4422 /* A temporary array for c_common_nodes_and_builtins.  Used in
4423    communication with def_fn_type.  */
4424 static tree builtin_types[(int) BT_LAST + 1];
4425
4426 /* A helper function for c_common_nodes_and_builtins.  Build function type
4427    for DEF with return type RET and N arguments.  If VAR is true, then the
4428    function should be variadic after those N arguments.
4429
4430    Takes special care not to ICE if any of the types involved are
4431    error_mark_node, which indicates that said type is not in fact available
4432    (see builtin_type_for_size).  In which case the function type as a whole
4433    should be error_mark_node.  */
4434
4435 static void
4436 def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...)
4437 {
4438   tree args = NULL, t;
4439   va_list list;
4440   int i;
4441
4442   va_start (list, n);
4443   for (i = 0; i < n; ++i)
4444     {
4445       builtin_type a = (builtin_type) va_arg (list, int);
4446       t = builtin_types[a];
4447       if (t == error_mark_node)
4448         goto egress;
4449       args = tree_cons (NULL_TREE, t, args);
4450     }
4451   va_end (list);
4452
4453   args = nreverse (args);
4454   if (!var)
4455     args = chainon (args, void_list_node);
4456
4457   t = builtin_types[ret];
4458   if (t == error_mark_node)
4459     goto egress;
4460   t = build_function_type (t, args);
4461
4462  egress:
4463   builtin_types[def] = t;
4464 }
4465
4466 /* Build builtin functions common to both C and C++ language
4467    frontends.  */
4468
4469 static void
4470 c_define_builtins (tree va_list_ref_type_node, tree va_list_arg_type_node)
4471 {
4472 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
4473   builtin_types[ENUM] = VALUE;
4474 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
4475   def_fn_type (ENUM, RETURN, 0, 0);
4476 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
4477   def_fn_type (ENUM, RETURN, 0, 1, ARG1);
4478 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
4479   def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
4480 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
4481   def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
4482 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
4483   def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
4484 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
4485   def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
4486 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
4487                             ARG6)                                       \
4488   def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
4489 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
4490                             ARG6, ARG7)                                 \
4491   def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
4492 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
4493   def_fn_type (ENUM, RETURN, 1, 0);
4494 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
4495   def_fn_type (ENUM, RETURN, 1, 1, ARG1);
4496 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
4497   def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
4498 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
4499   def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
4500 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
4501   def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
4502 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
4503   def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
4504 #define DEF_POINTER_TYPE(ENUM, TYPE) \
4505   builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
4506
4507 #include "builtin-types.def"
4508
4509 #undef DEF_PRIMITIVE_TYPE
4510 #undef DEF_FUNCTION_TYPE_1
4511 #undef DEF_FUNCTION_TYPE_2
4512 #undef DEF_FUNCTION_TYPE_3
4513 #undef DEF_FUNCTION_TYPE_4
4514 #undef DEF_FUNCTION_TYPE_5
4515 #undef DEF_FUNCTION_TYPE_6
4516 #undef DEF_FUNCTION_TYPE_VAR_0
4517 #undef DEF_FUNCTION_TYPE_VAR_1
4518 #undef DEF_FUNCTION_TYPE_VAR_2
4519 #undef DEF_FUNCTION_TYPE_VAR_3
4520 #undef DEF_FUNCTION_TYPE_VAR_4
4521 #undef DEF_FUNCTION_TYPE_VAR_5
4522 #undef DEF_POINTER_TYPE
4523   builtin_types[(int) BT_LAST] = NULL_TREE;
4524
4525   c_init_attributes ();
4526
4527 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
4528                     NONANSI_P, ATTRS, IMPLICIT, COND)                   \
4529   if (NAME && COND)                                                     \
4530     def_builtin_1 (ENUM, NAME, CLASS,                                   \
4531                    builtin_types[(int) TYPE],                           \
4532                    builtin_types[(int) LIBTYPE],                        \
4533                    BOTH_P, FALLBACK_P, NONANSI_P,                       \
4534                    built_in_attributes[(int) ATTRS], IMPLICIT);
4535 #include "builtins.def"
4536 #undef DEF_BUILTIN
4537
4538   targetm.init_builtins ();
4539
4540   build_common_builtin_nodes ();
4541
4542   if (flag_mudflap)
4543     mudflap_init ();
4544 }
4545
4546 /* Like get_identifier, but avoid warnings about null arguments when
4547    the argument may be NULL for targets where GCC lacks stdint.h type
4548    information.  */
4549
4550 static inline tree
4551 c_get_ident (const char *id)
4552 {
4553   return get_identifier (id);
4554 }
4555
4556 /* Build tree nodes and builtin functions common to both C and C++ language
4557    frontends.  */
4558
4559 void
4560 c_common_nodes_and_builtins (void)
4561 {
4562   int char16_type_size;
4563   int char32_type_size;
4564   int wchar_type_size;
4565   tree array_domain_type;
4566   tree va_list_ref_type_node;
4567   tree va_list_arg_type_node;
4568
4569   /* Define `int' and `char' first so that dbx will output them first.  */
4570   record_builtin_type (RID_INT, NULL, integer_type_node);
4571   record_builtin_type (RID_CHAR, "char", char_type_node);
4572
4573   /* `signed' is the same as `int'.  FIXME: the declarations of "signed",
4574      "unsigned long", "long long unsigned" and "unsigned short" were in C++
4575      but not C.  Are the conditionals here needed?  */
4576   if (c_dialect_cxx ())
4577     record_builtin_type (RID_SIGNED, NULL, integer_type_node);
4578   record_builtin_type (RID_LONG, "long int", long_integer_type_node);
4579   record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
4580   record_builtin_type (RID_MAX, "long unsigned int",
4581                        long_unsigned_type_node);
4582   if (c_dialect_cxx ())
4583     record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
4584   record_builtin_type (RID_MAX, "long long int",
4585                        long_long_integer_type_node);
4586   record_builtin_type (RID_MAX, "long long unsigned int",
4587                        long_long_unsigned_type_node);
4588   if (c_dialect_cxx ())
4589     record_builtin_type (RID_MAX, "long long unsigned",
4590                          long_long_unsigned_type_node);
4591   record_builtin_type (RID_SHORT, "short int", short_integer_type_node);
4592   record_builtin_type (RID_MAX, "short unsigned int",
4593                        short_unsigned_type_node);
4594   if (c_dialect_cxx ())
4595     record_builtin_type (RID_MAX, "unsigned short",
4596                          short_unsigned_type_node);
4597
4598   /* Define both `signed char' and `unsigned char'.  */
4599   record_builtin_type (RID_MAX, "signed char", signed_char_type_node);
4600   record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node);
4601
4602   /* These are types that c_common_type_for_size and
4603      c_common_type_for_mode use.  */
4604   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4605                                          TYPE_DECL, NULL_TREE,
4606                                          intQI_type_node));
4607   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4608                                          TYPE_DECL, NULL_TREE,
4609                                          intHI_type_node));
4610   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4611                                          TYPE_DECL, NULL_TREE,
4612                                          intSI_type_node));
4613   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4614                                          TYPE_DECL, NULL_TREE,
4615                                          intDI_type_node));
4616 #if HOST_BITS_PER_WIDE_INT >= 64
4617   if (targetm.scalar_mode_supported_p (TImode))
4618     lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4619                                            TYPE_DECL,
4620                                            get_identifier ("__int128_t"),
4621                                            intTI_type_node));
4622 #endif
4623   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4624                                          TYPE_DECL, NULL_TREE,
4625                                          unsigned_intQI_type_node));
4626   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4627                                          TYPE_DECL, NULL_TREE,
4628                                          unsigned_intHI_type_node));
4629   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4630                                          TYPE_DECL, NULL_TREE,
4631                                          unsigned_intSI_type_node));
4632   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4633                                          TYPE_DECL, NULL_TREE,
4634                                          unsigned_intDI_type_node));
4635 #if HOST_BITS_PER_WIDE_INT >= 64
4636   if (targetm.scalar_mode_supported_p (TImode))
4637     lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4638                                            TYPE_DECL,
4639                                            get_identifier ("__uint128_t"),
4640                                            unsigned_intTI_type_node));
4641 #endif
4642
4643   /* Create the widest literal types.  */
4644   widest_integer_literal_type_node
4645     = make_signed_type (HOST_BITS_PER_WIDE_INT * 2);
4646   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4647                                          TYPE_DECL, NULL_TREE,
4648                                          widest_integer_literal_type_node));
4649
4650   widest_unsigned_literal_type_node
4651     = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2);
4652   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4653                                          TYPE_DECL, NULL_TREE,
4654                                          widest_unsigned_literal_type_node));
4655
4656   /* `unsigned long' is the standard type for sizeof.
4657      Note that stddef.h uses `unsigned long',
4658      and this must agree, even if long and int are the same size.  */
4659   size_type_node =
4660     TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE)));
4661   signed_size_type_node = c_common_signed_type (size_type_node);
4662   set_sizetype (size_type_node);
4663
4664   pid_type_node =
4665     TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE)));
4666
4667   build_common_tree_nodes_2 (flag_short_double);
4668
4669   record_builtin_type (RID_FLOAT, NULL, float_type_node);
4670   record_builtin_type (RID_DOUBLE, NULL, double_type_node);
4671   record_builtin_type (RID_MAX, "long double", long_double_type_node);
4672
4673   /* Only supported decimal floating point extension if the target
4674      actually supports underlying modes. */
4675   if (targetm.scalar_mode_supported_p (SDmode)
4676       && targetm.scalar_mode_supported_p (DDmode)
4677       && targetm.scalar_mode_supported_p (TDmode))
4678     {
4679       record_builtin_type (RID_DFLOAT32, NULL, dfloat32_type_node);
4680       record_builtin_type (RID_DFLOAT64, NULL, dfloat64_type_node);
4681       record_builtin_type (RID_DFLOAT128, NULL, dfloat128_type_node);
4682     }
4683
4684   if (targetm.fixed_point_supported_p ())
4685     {
4686       record_builtin_type (RID_MAX, "short _Fract", short_fract_type_node);
4687       record_builtin_type (RID_FRACT, NULL, fract_type_node);
4688       record_builtin_type (RID_MAX, "long _Fract", long_fract_type_node);
4689       record_builtin_type (RID_MAX, "long long _Fract",
4690                            long_long_fract_type_node);
4691       record_builtin_type (RID_MAX, "unsigned short _Fract",
4692                            unsigned_short_fract_type_node);
4693       record_builtin_type (RID_MAX, "unsigned _Fract",
4694                            unsigned_fract_type_node);
4695       record_builtin_type (RID_MAX, "unsigned long _Fract",
4696                            unsigned_long_fract_type_node);
4697       record_builtin_type (RID_MAX, "unsigned long long _Fract",
4698                            unsigned_long_long_fract_type_node);
4699       record_builtin_type (RID_MAX, "_Sat short _Fract",
4700                            sat_short_fract_type_node);
4701       record_builtin_type (RID_MAX, "_Sat _Fract", sat_fract_type_node);
4702       record_builtin_type (RID_MAX, "_Sat long _Fract",
4703                            sat_long_fract_type_node);
4704       record_builtin_type (RID_MAX, "_Sat long long _Fract",
4705                            sat_long_long_fract_type_node);
4706       record_builtin_type (RID_MAX, "_Sat unsigned short _Fract",
4707                            sat_unsigned_short_fract_type_node);
4708       record_builtin_type (RID_MAX, "_Sat unsigned _Fract",
4709                            sat_unsigned_fract_type_node);
4710       record_builtin_type (RID_MAX, "_Sat unsigned long _Fract",
4711                            sat_unsigned_long_fract_type_node);
4712       record_builtin_type (RID_MAX, "_Sat unsigned long long _Fract",
4713                            sat_unsigned_long_long_fract_type_node);
4714       record_builtin_type (RID_MAX, "short _Accum", short_accum_type_node);
4715       record_builtin_type (RID_ACCUM, NULL, accum_type_node);
4716       record_builtin_type (RID_MAX, "long _Accum", long_accum_type_node);
4717       record_builtin_type (RID_MAX, "long long _Accum",
4718                            long_long_accum_type_node);
4719       record_builtin_type (RID_MAX, "unsigned short _Accum",
4720                            unsigned_short_accum_type_node);
4721       record_builtin_type (RID_MAX, "unsigned _Accum",
4722                            unsigned_accum_type_node);
4723       record_builtin_type (RID_MAX, "unsigned long _Accum",
4724                            unsigned_long_accum_type_node);
4725       record_builtin_type (RID_MAX, "unsigned long long _Accum",
4726                            unsigned_long_long_accum_type_node);
4727       record_builtin_type (RID_MAX, "_Sat short _Accum",
4728                            sat_short_accum_type_node);
4729       record_builtin_type (RID_MAX, "_Sat _Accum", sat_accum_type_node);
4730       record_builtin_type (RID_MAX, "_Sat long _Accum",
4731                            sat_long_accum_type_node);
4732       record_builtin_type (RID_MAX, "_Sat long long _Accum",
4733                           sat_long_long_accum_type_node);
4734       record_builtin_type (RID_MAX, "_Sat unsigned short _Accum",
4735                            sat_unsigned_short_accum_type_node);
4736       record_builtin_type (RID_MAX, "_Sat unsigned _Accum",
4737                            sat_unsigned_accum_type_node);
4738       record_builtin_type (RID_MAX, "_Sat unsigned long _Accum",
4739                            sat_unsigned_long_accum_type_node);
4740       record_builtin_type (RID_MAX, "_Sat unsigned long long _Accum",
4741                            sat_unsigned_long_long_accum_type_node);
4742
4743     }
4744
4745   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4746                                          TYPE_DECL,
4747                                          get_identifier ("complex int"),
4748                                          complex_integer_type_node));
4749   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4750                                          TYPE_DECL,
4751                                          get_identifier ("complex float"),
4752                                          complex_float_type_node));
4753   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4754                                          TYPE_DECL,
4755                                          get_identifier ("complex double"),
4756                                          complex_double_type_node));
4757   lang_hooks.decls.pushdecl
4758     (build_decl (UNKNOWN_LOCATION,
4759                  TYPE_DECL, get_identifier ("complex long double"),
4760                  complex_long_double_type_node));
4761
4762   if (c_dialect_cxx ())
4763     /* For C++, make fileptr_type_node a distinct void * type until
4764        FILE type is defined.  */
4765     fileptr_type_node = build_variant_type_copy (ptr_type_node);
4766
4767   record_builtin_type (RID_VOID, NULL, void_type_node);
4768
4769   /* Set the TYPE_NAME for any variants that were built before
4770      record_builtin_type gave names to the built-in types. */
4771   {
4772     tree void_name = TYPE_NAME (void_type_node);
4773     TYPE_NAME (void_type_node) = NULL_TREE;
4774     TYPE_NAME (build_qualified_type (void_type_node, TYPE_QUAL_CONST))
4775       = void_name;
4776     TYPE_NAME (void_type_node) = void_name;
4777   }
4778
4779   /* This node must not be shared.  */
4780   void_zero_node = make_node (INTEGER_CST);
4781   TREE_TYPE (void_zero_node) = void_type_node;
4782
4783   void_list_node = build_void_list_node ();
4784
4785   /* Make a type to be the domain of a few array types
4786      whose domains don't really matter.
4787      200 is small enough that it always fits in size_t
4788      and large enough that it can hold most function names for the
4789      initializations of __FUNCTION__ and __PRETTY_FUNCTION__.  */
4790   array_domain_type = build_index_type (size_int (200));
4791
4792   /* Make a type for arrays of characters.
4793      With luck nothing will ever really depend on the length of this
4794      array type.  */
4795   char_array_type_node
4796     = build_array_type (char_type_node, array_domain_type);
4797
4798   /* Likewise for arrays of ints.  */
4799   int_array_type_node
4800     = build_array_type (integer_type_node, array_domain_type);
4801
4802   string_type_node = build_pointer_type (char_type_node);
4803   const_string_type_node
4804     = build_pointer_type (build_qualified_type
4805                           (char_type_node, TYPE_QUAL_CONST));
4806
4807   /* This is special for C++ so functions can be overloaded.  */
4808   wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE);
4809   wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node));
4810   wchar_type_size = TYPE_PRECISION (wchar_type_node);
4811   underlying_wchar_type_node = wchar_type_node;
4812   if (c_dialect_cxx ())
4813     {
4814       if (TYPE_UNSIGNED (wchar_type_node))
4815         wchar_type_node = make_unsigned_type (wchar_type_size);
4816       else
4817         wchar_type_node = make_signed_type (wchar_type_size);
4818       record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node);
4819     }
4820
4821   /* This is for wide string constants.  */
4822   wchar_array_type_node
4823     = build_array_type (wchar_type_node, array_domain_type);
4824
4825   /* Define 'char16_t'.  */
4826   char16_type_node = get_identifier (CHAR16_TYPE);
4827   char16_type_node = TREE_TYPE (identifier_global_value (char16_type_node));
4828   char16_type_size = TYPE_PRECISION (char16_type_node);
4829   if (c_dialect_cxx ())
4830     {
4831       char16_type_node = make_unsigned_type (char16_type_size);
4832
4833       if (cxx_dialect == cxx0x)
4834         record_builtin_type (RID_CHAR16, "char16_t", char16_type_node);
4835     }
4836
4837   /* This is for UTF-16 string constants.  */
4838   char16_array_type_node
4839     = build_array_type (char16_type_node, array_domain_type);
4840
4841   /* Define 'char32_t'.  */
4842   char32_type_node = get_identifier (CHAR32_TYPE);
4843   char32_type_node = TREE_TYPE (identifier_global_value (char32_type_node));
4844   char32_type_size = TYPE_PRECISION (char32_type_node);
4845   if (c_dialect_cxx ())
4846     {
4847       char32_type_node = make_unsigned_type (char32_type_size);
4848
4849       if (cxx_dialect == cxx0x)
4850         record_builtin_type (RID_CHAR32, "char32_t", char32_type_node);
4851     }
4852
4853   /* This is for UTF-32 string constants.  */
4854   char32_array_type_node
4855     = build_array_type (char32_type_node, array_domain_type);
4856
4857   wint_type_node =
4858     TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE)));
4859
4860   intmax_type_node =
4861     TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE)));
4862   uintmax_type_node =
4863     TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE)));
4864
4865   if (SIG_ATOMIC_TYPE)
4866     sig_atomic_type_node =
4867       TREE_TYPE (identifier_global_value (c_get_ident (SIG_ATOMIC_TYPE)));
4868   if (INT8_TYPE)
4869     int8_type_node =
4870       TREE_TYPE (identifier_global_value (c_get_ident (INT8_TYPE)));
4871   if (INT16_TYPE)
4872     int16_type_node =
4873       TREE_TYPE (identifier_global_value (c_get_ident (INT16_TYPE)));
4874   if (INT32_TYPE)
4875     int32_type_node =
4876       TREE_TYPE (identifier_global_value (c_get_ident (INT32_TYPE)));
4877   if (INT64_TYPE)
4878     int64_type_node =
4879       TREE_TYPE (identifier_global_value (c_get_ident (INT64_TYPE)));
4880   if (UINT8_TYPE)
4881     uint8_type_node =
4882       TREE_TYPE (identifier_global_value (c_get_ident (UINT8_TYPE)));
4883   if (UINT16_TYPE)
4884     uint16_type_node =
4885       TREE_TYPE (identifier_global_value (c_get_ident (UINT16_TYPE)));
4886   if (UINT32_TYPE)
4887     c_uint32_type_node =
4888       TREE_TYPE (identifier_global_value (c_get_ident (UINT32_TYPE)));
4889   if (UINT64_TYPE)
4890     c_uint64_type_node =
4891       TREE_TYPE (identifier_global_value (c_get_ident (UINT64_TYPE)));
4892   if (INT_LEAST8_TYPE)
4893     int_least8_type_node =
4894       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST8_TYPE)));
4895   if (INT_LEAST16_TYPE)
4896     int_least16_type_node =
4897       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST16_TYPE)));
4898   if (INT_LEAST32_TYPE)
4899     int_least32_type_node =
4900       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST32_TYPE)));
4901   if (INT_LEAST64_TYPE)
4902     int_least64_type_node =
4903       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST64_TYPE)));
4904   if (UINT_LEAST8_TYPE)
4905     uint_least8_type_node =
4906       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST8_TYPE)));
4907   if (UINT_LEAST16_TYPE)
4908     uint_least16_type_node =
4909       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST16_TYPE)));
4910   if (UINT_LEAST32_TYPE)
4911     uint_least32_type_node =
4912       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST32_TYPE)));
4913   if (UINT_LEAST64_TYPE)
4914     uint_least64_type_node =
4915       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST64_TYPE)));
4916   if (INT_FAST8_TYPE)
4917     int_fast8_type_node =
4918       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST8_TYPE)));
4919   if (INT_FAST16_TYPE)
4920     int_fast16_type_node =
4921       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST16_TYPE)));
4922   if (INT_FAST32_TYPE)
4923     int_fast32_type_node =
4924       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST32_TYPE)));
4925   if (INT_FAST64_TYPE)
4926     int_fast64_type_node =
4927       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST64_TYPE)));
4928   if (UINT_FAST8_TYPE)
4929     uint_fast8_type_node =
4930       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST8_TYPE)));
4931   if (UINT_FAST16_TYPE)
4932     uint_fast16_type_node =
4933       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST16_TYPE)));
4934   if (UINT_FAST32_TYPE)
4935     uint_fast32_type_node =
4936       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST32_TYPE)));
4937   if (UINT_FAST64_TYPE)
4938     uint_fast64_type_node =
4939       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST64_TYPE)));
4940   if (INTPTR_TYPE)
4941     intptr_type_node =
4942       TREE_TYPE (identifier_global_value (c_get_ident (INTPTR_TYPE)));
4943   if (UINTPTR_TYPE)
4944     uintptr_type_node =
4945       TREE_TYPE (identifier_global_value (c_get_ident (UINTPTR_TYPE)));
4946
4947   default_function_type = build_function_type (integer_type_node, NULL_TREE);
4948   ptrdiff_type_node
4949     = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE)));
4950   unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node);
4951
4952   lang_hooks.decls.pushdecl
4953     (build_decl (UNKNOWN_LOCATION,
4954                  TYPE_DECL, get_identifier ("__builtin_va_list"),
4955                  va_list_type_node));
4956 #ifdef TARGET_ENUM_VA_LIST
4957   {
4958     int l;
4959     const char *pname;
4960     tree ptype;
4961     for (l = 0; TARGET_ENUM_VA_LIST (l, &pname, &ptype); ++l)
4962       {
4963         lang_hooks.decls.pushdecl
4964           (build_decl (UNKNOWN_LOCATION,
4965                        TYPE_DECL, get_identifier (pname),
4966                        ptype));
4967
4968       }
4969   }
4970 #endif
4971
4972   if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
4973     {
4974       va_list_arg_type_node = va_list_ref_type_node =
4975         build_pointer_type (TREE_TYPE (va_list_type_node));
4976     }
4977   else
4978     {
4979       va_list_arg_type_node = va_list_type_node;
4980       va_list_ref_type_node = build_reference_type (va_list_type_node);
4981     }
4982
4983   if (!flag_preprocess_only)
4984     c_define_builtins (va_list_ref_type_node, va_list_arg_type_node);
4985
4986   main_identifier_node = get_identifier ("main");
4987
4988   /* Create the built-in __null node.  It is important that this is
4989      not shared.  */
4990   null_node = make_node (INTEGER_CST);
4991   TREE_TYPE (null_node) = c_common_type_for_size (POINTER_SIZE, 0);
4992
4993   /* Since builtin_types isn't gc'ed, don't export these nodes.  */
4994   memset (builtin_types, 0, sizeof (builtin_types));
4995 }
4996
4997 /* Look up the function in built_in_decls that corresponds to DECL
4998    and set ASMSPEC as its user assembler name.  DECL must be a
4999    function decl that declares a builtin.  */
5000
5001 void
5002 set_builtin_user_assembler_name (tree decl, const char *asmspec)
5003 {
5004   tree builtin;
5005   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
5006               && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
5007               && asmspec != 0);
5008
5009   builtin = built_in_decls [DECL_FUNCTION_CODE (decl)];
5010   set_user_assembler_name (builtin, asmspec);
5011   switch (DECL_FUNCTION_CODE (decl))
5012     {
5013     case BUILT_IN_MEMCPY:
5014       init_block_move_fn (asmspec);
5015       memcpy_libfunc = set_user_assembler_libfunc ("memcpy", asmspec);
5016       break;
5017     case BUILT_IN_MEMSET:
5018       init_block_clear_fn (asmspec);
5019       memset_libfunc = set_user_assembler_libfunc ("memset", asmspec);
5020       break;
5021     case BUILT_IN_MEMMOVE:
5022       memmove_libfunc = set_user_assembler_libfunc ("memmove", asmspec);
5023       break;
5024     case BUILT_IN_MEMCMP:
5025       memcmp_libfunc = set_user_assembler_libfunc ("memcmp", asmspec);
5026       break;
5027     case BUILT_IN_ABORT:
5028       abort_libfunc = set_user_assembler_libfunc ("abort", asmspec);
5029       break;
5030     default:
5031       break;
5032     }
5033 }
5034
5035 /* The number of named compound-literals generated thus far.  */
5036 static GTY(()) int compound_literal_number;
5037
5038 /* Set DECL_NAME for DECL, a VAR_DECL for a compound-literal.  */
5039
5040 void
5041 set_compound_literal_name (tree decl)
5042 {
5043   char *name;
5044   ASM_FORMAT_PRIVATE_NAME (name, "__compound_literal",
5045                            compound_literal_number);
5046   compound_literal_number++;
5047   DECL_NAME (decl) = get_identifier (name);
5048 }
5049
5050 tree
5051 build_va_arg (location_t loc, tree expr, tree type)
5052 {
5053   expr = build1 (VA_ARG_EXPR, type, expr);
5054   SET_EXPR_LOCATION (expr, loc);
5055   return expr;
5056 }
5057
5058
5059 /* Linked list of disabled built-in functions.  */
5060
5061 typedef struct disabled_builtin
5062 {
5063   const char *name;
5064   struct disabled_builtin *next;
5065 } disabled_builtin;
5066 static disabled_builtin *disabled_builtins = NULL;
5067
5068 static bool builtin_function_disabled_p (const char *);
5069
5070 /* Disable a built-in function specified by -fno-builtin-NAME.  If NAME
5071    begins with "__builtin_", give an error.  */
5072
5073 void
5074 disable_builtin_function (const char *name)
5075 {
5076   if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
5077     error ("cannot disable built-in function %qs", name);
5078   else
5079     {
5080       disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin);
5081       new_disabled_builtin->name = name;
5082       new_disabled_builtin->next = disabled_builtins;
5083       disabled_builtins = new_disabled_builtin;
5084     }
5085 }
5086
5087
5088 /* Return true if the built-in function NAME has been disabled, false
5089    otherwise.  */
5090
5091 static bool
5092 builtin_function_disabled_p (const char *name)
5093 {
5094   disabled_builtin *p;
5095   for (p = disabled_builtins; p != NULL; p = p->next)
5096     {
5097       if (strcmp (name, p->name) == 0)
5098         return true;
5099     }
5100   return false;
5101 }
5102
5103
5104 /* Worker for DEF_BUILTIN.
5105    Possibly define a builtin function with one or two names.
5106    Does not declare a non-__builtin_ function if flag_no_builtin, or if
5107    nonansi_p and flag_no_nonansi_builtin.  */
5108
5109 static void
5110 def_builtin_1 (enum built_in_function fncode,
5111                const char *name,
5112                enum built_in_class fnclass,
5113                tree fntype, tree libtype,
5114                bool both_p, bool fallback_p, bool nonansi_p,
5115                tree fnattrs, bool implicit_p)
5116 {
5117   tree decl;
5118   const char *libname;
5119
5120   if (fntype == error_mark_node)
5121     return;
5122
5123   gcc_assert ((!both_p && !fallback_p)
5124               || !strncmp (name, "__builtin_",
5125                            strlen ("__builtin_")));
5126
5127   libname = name + strlen ("__builtin_");
5128   decl = add_builtin_function (name, fntype, fncode, fnclass,
5129                                (fallback_p ? libname : NULL),
5130                                fnattrs);
5131   if (both_p
5132       && !flag_no_builtin && !builtin_function_disabled_p (libname)
5133       && !(nonansi_p && flag_no_nonansi_builtin))
5134     add_builtin_function (libname, libtype, fncode, fnclass,
5135                           NULL, fnattrs);
5136
5137   built_in_decls[(int) fncode] = decl;
5138   if (implicit_p)
5139     implicit_built_in_decls[(int) fncode] = decl;
5140 }
5141 \f
5142 /* Nonzero if the type T promotes to int.  This is (nearly) the
5143    integral promotions defined in ISO C99 6.3.1.1/2.  */
5144
5145 bool
5146 c_promoting_integer_type_p (const_tree t)
5147 {
5148   switch (TREE_CODE (t))
5149     {
5150     case INTEGER_TYPE:
5151       return (TYPE_MAIN_VARIANT (t) == char_type_node
5152               || TYPE_MAIN_VARIANT (t) == signed_char_type_node
5153               || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node
5154               || TYPE_MAIN_VARIANT (t) == short_integer_type_node
5155               || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node
5156               || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node));
5157
5158     case ENUMERAL_TYPE:
5159       /* ??? Technically all enumerations not larger than an int
5160          promote to an int.  But this is used along code paths
5161          that only want to notice a size change.  */
5162       return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node);
5163
5164     case BOOLEAN_TYPE:
5165       return 1;
5166
5167     default:
5168       return 0;
5169     }
5170 }
5171
5172 /* Return 1 if PARMS specifies a fixed number of parameters
5173    and none of their types is affected by default promotions.  */
5174
5175 int
5176 self_promoting_args_p (const_tree parms)
5177 {
5178   const_tree t;
5179   for (t = parms; t; t = TREE_CHAIN (t))
5180     {
5181       tree type = TREE_VALUE (t);
5182
5183       if (type == error_mark_node)
5184         continue;
5185
5186       if (TREE_CHAIN (t) == 0 && type != void_type_node)
5187         return 0;
5188
5189       if (type == 0)
5190         return 0;
5191
5192       if (TYPE_MAIN_VARIANT (type) == float_type_node)
5193         return 0;
5194
5195       if (c_promoting_integer_type_p (type))
5196         return 0;
5197     }
5198   return 1;
5199 }
5200
5201 /* Recursively remove any '*' or '&' operator from TYPE.  */
5202 tree
5203 strip_pointer_operator (tree t)
5204 {
5205   while (POINTER_TYPE_P (t))
5206     t = TREE_TYPE (t);
5207   return t;
5208 }
5209
5210 /* Recursively remove pointer or array type from TYPE. */
5211 tree
5212 strip_pointer_or_array_types (tree t)
5213 {
5214   while (TREE_CODE (t) == ARRAY_TYPE || POINTER_TYPE_P (t))
5215     t = TREE_TYPE (t);
5216   return t;
5217 }
5218
5219 /* Used to compare case labels.  K1 and K2 are actually tree nodes
5220    representing case labels, or NULL_TREE for a `default' label.
5221    Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
5222    K2, and 0 if K1 and K2 are equal.  */
5223
5224 int
5225 case_compare (splay_tree_key k1, splay_tree_key k2)
5226 {
5227   /* Consider a NULL key (such as arises with a `default' label) to be
5228      smaller than anything else.  */
5229   if (!k1)
5230     return k2 ? -1 : 0;
5231   else if (!k2)
5232     return k1 ? 1 : 0;
5233
5234   return tree_int_cst_compare ((tree) k1, (tree) k2);
5235 }
5236
5237 /* Process a case label, located at LOC, for the range LOW_VALUE
5238    ... HIGH_VALUE.  If LOW_VALUE and HIGH_VALUE are both NULL_TREE
5239    then this case label is actually a `default' label.  If only
5240    HIGH_VALUE is NULL_TREE, then case label was declared using the
5241    usual C/C++ syntax, rather than the GNU case range extension.
5242    CASES is a tree containing all the case ranges processed so far;
5243    COND is the condition for the switch-statement itself.  Returns the
5244    CASE_LABEL_EXPR created, or ERROR_MARK_NODE if no CASE_LABEL_EXPR
5245    is created.  */
5246
5247 tree
5248 c_add_case_label (location_t loc, splay_tree cases, tree cond, tree orig_type,
5249                   tree low_value, tree high_value)
5250 {
5251   tree type;
5252   tree label;
5253   tree case_label;
5254   splay_tree_node node;
5255
5256   /* Create the LABEL_DECL itself.  */
5257   label = create_artificial_label (loc);
5258
5259   /* If there was an error processing the switch condition, bail now
5260      before we get more confused.  */
5261   if (!cond || cond == error_mark_node)
5262     goto error_out;
5263
5264   if ((low_value && TREE_TYPE (low_value)
5265        && POINTER_TYPE_P (TREE_TYPE (low_value)))
5266       || (high_value && TREE_TYPE (high_value)
5267           && POINTER_TYPE_P (TREE_TYPE (high_value))))
5268     {
5269       error_at (loc, "pointers are not permitted as case values");
5270       goto error_out;
5271     }
5272
5273   /* Case ranges are a GNU extension.  */
5274   if (high_value)
5275     pedwarn (loc, OPT_pedantic,
5276              "range expressions in switch statements are non-standard");
5277
5278   type = TREE_TYPE (cond);
5279   if (low_value)
5280     {
5281       low_value = check_case_value (low_value);
5282       low_value = convert_and_check (type, low_value);
5283       if (low_value == error_mark_node)
5284         goto error_out;
5285     }
5286   if (high_value)
5287     {
5288       high_value = check_case_value (high_value);
5289       high_value = convert_and_check (type, high_value);
5290       if (high_value == error_mark_node)
5291         goto error_out;
5292     }
5293
5294   if (low_value && high_value)
5295     {
5296       /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
5297          really a case range, even though it was written that way.
5298          Remove the HIGH_VALUE to simplify later processing.  */
5299       if (tree_int_cst_equal (low_value, high_value))
5300         high_value = NULL_TREE;
5301       else if (!tree_int_cst_lt (low_value, high_value))
5302         warning_at (loc, 0, "empty range specified");
5303     }
5304
5305   /* See if the case is in range of the type of the original testing
5306      expression.  If both low_value and high_value are out of range,
5307      don't insert the case label and return NULL_TREE.  */
5308   if (low_value
5309       && !check_case_bounds (type, orig_type,
5310                              &low_value, high_value ? &high_value : NULL))
5311     return NULL_TREE;
5312
5313   /* Look up the LOW_VALUE in the table of case labels we already
5314      have.  */
5315   node = splay_tree_lookup (cases, (splay_tree_key) low_value);
5316   /* If there was not an exact match, check for overlapping ranges.
5317      There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
5318      that's a `default' label and the only overlap is an exact match.  */
5319   if (!node && (low_value || high_value))
5320     {
5321       splay_tree_node low_bound;
5322       splay_tree_node high_bound;
5323
5324       /* Even though there wasn't an exact match, there might be an
5325          overlap between this case range and another case range.
5326          Since we've (inductively) not allowed any overlapping case
5327          ranges, we simply need to find the greatest low case label
5328          that is smaller that LOW_VALUE, and the smallest low case
5329          label that is greater than LOW_VALUE.  If there is an overlap
5330          it will occur in one of these two ranges.  */
5331       low_bound = splay_tree_predecessor (cases,
5332                                           (splay_tree_key) low_value);
5333       high_bound = splay_tree_successor (cases,
5334                                          (splay_tree_key) low_value);
5335
5336       /* Check to see if the LOW_BOUND overlaps.  It is smaller than
5337          the LOW_VALUE, so there is no need to check unless the
5338          LOW_BOUND is in fact itself a case range.  */
5339       if (low_bound
5340           && CASE_HIGH ((tree) low_bound->value)
5341           && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
5342                                     low_value) >= 0)
5343         node = low_bound;
5344       /* Check to see if the HIGH_BOUND overlaps.  The low end of that
5345          range is bigger than the low end of the current range, so we
5346          are only interested if the current range is a real range, and
5347          not an ordinary case label.  */
5348       else if (high_bound
5349                && high_value
5350                && (tree_int_cst_compare ((tree) high_bound->key,
5351                                          high_value)
5352                    <= 0))
5353         node = high_bound;
5354     }
5355   /* If there was an overlap, issue an error.  */
5356   if (node)
5357     {
5358       tree duplicate = CASE_LABEL ((tree) node->value);
5359
5360       if (high_value)
5361         {
5362           error_at (loc, "duplicate (or overlapping) case value");
5363           error_at (DECL_SOURCE_LOCATION (duplicate),
5364                     "this is the first entry overlapping that value");
5365         }
5366       else if (low_value)
5367         {
5368           error_at (loc, "duplicate case value") ;
5369           error_at (DECL_SOURCE_LOCATION (duplicate), "previously used here");
5370         }
5371       else
5372         {
5373           error_at (loc, "multiple default labels in one switch");
5374           error_at (DECL_SOURCE_LOCATION (duplicate),
5375                     "this is the first default label");
5376         }
5377       goto error_out;
5378     }
5379
5380   /* Add a CASE_LABEL to the statement-tree.  */
5381   case_label = add_stmt (build_case_label (loc, low_value, high_value, label));
5382   /* Register this case label in the splay tree.  */
5383   splay_tree_insert (cases,
5384                      (splay_tree_key) low_value,
5385                      (splay_tree_value) case_label);
5386
5387   return case_label;
5388
5389  error_out:
5390   /* Add a label so that the back-end doesn't think that the beginning of
5391      the switch is unreachable.  Note that we do not add a case label, as
5392      that just leads to duplicates and thence to failure later on.  */
5393   if (!cases->root)
5394     {
5395       tree t = create_artificial_label (loc);
5396       add_stmt (build_stmt (loc, LABEL_EXPR, t));
5397     }
5398   return error_mark_node;
5399 }
5400
5401 /* Subroutines of c_do_switch_warnings, called via splay_tree_foreach.
5402    Used to verify that case values match up with enumerator values.  */
5403
5404 static void
5405 match_case_to_enum_1 (tree key, tree type, tree label)
5406 {
5407   char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1];
5408
5409   /* ??? Not working too hard to print the double-word value.
5410      Should perhaps be done with %lwd in the diagnostic routines?  */
5411   if (TREE_INT_CST_HIGH (key) == 0)
5412     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED,
5413               TREE_INT_CST_LOW (key));
5414   else if (!TYPE_UNSIGNED (type)
5415            && TREE_INT_CST_HIGH (key) == -1
5416            && TREE_INT_CST_LOW (key) != 0)
5417     snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED,
5418               -TREE_INT_CST_LOW (key));
5419   else
5420     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX,
5421               (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (key),
5422               (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (key));
5423
5424   if (TYPE_NAME (type) == 0)
5425     warning (warn_switch ? OPT_Wswitch : OPT_Wswitch_enum,
5426              "%Jcase value %qs not in enumerated type",
5427              CASE_LABEL (label), buf);
5428   else
5429     warning (warn_switch ? OPT_Wswitch : OPT_Wswitch_enum,
5430              "%Jcase value %qs not in enumerated type %qT",
5431              CASE_LABEL (label), buf, type);
5432 }
5433
5434 /* Subroutine of c_do_switch_warnings, called via splay_tree_foreach.
5435    Used to verify that case values match up with enumerator values.  */
5436
5437 static int
5438 match_case_to_enum (splay_tree_node node, void *data)
5439 {
5440   tree label = (tree) node->value;
5441   tree type = (tree) data;
5442
5443   /* Skip default case.  */
5444   if (!CASE_LOW (label))
5445     return 0;
5446
5447   /* If CASE_LOW_SEEN is not set, that means CASE_LOW did not appear
5448      when we did our enum->case scan.  Reset our scratch bit after.  */
5449   if (!CASE_LOW_SEEN (label))
5450     match_case_to_enum_1 (CASE_LOW (label), type, label);
5451   else
5452     CASE_LOW_SEEN (label) = 0;
5453
5454   /* If CASE_HIGH is non-null, we have a range.  If CASE_HIGH_SEEN is
5455      not set, that means that CASE_HIGH did not appear when we did our
5456      enum->case scan.  Reset our scratch bit after.  */
5457   if (CASE_HIGH (label))
5458     {
5459       if (!CASE_HIGH_SEEN (label))
5460         match_case_to_enum_1 (CASE_HIGH (label), type, label);
5461       else
5462         CASE_HIGH_SEEN (label) = 0;
5463     }
5464
5465   return 0;
5466 }
5467
5468 /* Handle -Wswitch*.  Called from the front end after parsing the
5469    switch construct.  */
5470 /* ??? Should probably be somewhere generic, since other languages
5471    besides C and C++ would want this.  At the moment, however, C/C++
5472    are the only tree-ssa languages that support enumerations at all,
5473    so the point is moot.  */
5474
5475 void
5476 c_do_switch_warnings (splay_tree cases, location_t switch_location,
5477                       tree type, tree cond)
5478 {
5479   splay_tree_node default_node;
5480   splay_tree_node node;
5481   tree chain;
5482
5483   if (!warn_switch && !warn_switch_enum && !warn_switch_default)
5484     return;
5485
5486   default_node = splay_tree_lookup (cases, (splay_tree_key) NULL);
5487   if (!default_node)
5488     warning (OPT_Wswitch_default, "%Hswitch missing default case",
5489              &switch_location);
5490
5491   /* From here on, we only care about about enumerated types.  */
5492   if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
5493     return;
5494
5495   /* From here on, we only care about -Wswitch and -Wswitch-enum.  */
5496   if (!warn_switch_enum && !warn_switch)
5497     return;
5498
5499   /* Check the cases.  Warn about case values which are not members of
5500      the enumerated type.  For -Wswitch-enum, or for -Wswitch when
5501      there is no default case, check that exactly all enumeration
5502      literals are covered by the cases.  */
5503
5504   /* Clearing COND if it is not an integer constant simplifies
5505      the tests inside the loop below.  */
5506   if (TREE_CODE (cond) != INTEGER_CST)
5507     cond = NULL_TREE;
5508
5509   /* The time complexity here is O(N*lg(N)) worst case, but for the
5510       common case of monotonically increasing enumerators, it is
5511       O(N), since the nature of the splay tree will keep the next
5512       element adjacent to the root at all times.  */
5513
5514   for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain))
5515     {
5516       tree value = TREE_VALUE (chain);
5517       if (TREE_CODE (value) == CONST_DECL)
5518         value = DECL_INITIAL (value);
5519       node = splay_tree_lookup (cases, (splay_tree_key) value);
5520       if (node)
5521         {
5522           /* Mark the CASE_LOW part of the case entry as seen.  */
5523           tree label = (tree) node->value;
5524           CASE_LOW_SEEN (label) = 1;
5525           continue;
5526         }
5527
5528       /* Even though there wasn't an exact match, there might be a
5529          case range which includes the enumerator's value.  */
5530       node = splay_tree_predecessor (cases, (splay_tree_key) value);
5531       if (node && CASE_HIGH ((tree) node->value))
5532         {
5533           tree label = (tree) node->value;
5534           int cmp = tree_int_cst_compare (CASE_HIGH (label), value);
5535           if (cmp >= 0)
5536             {
5537               /* If we match the upper bound exactly, mark the CASE_HIGH
5538                  part of the case entry as seen.  */
5539               if (cmp == 0)
5540                 CASE_HIGH_SEEN (label) = 1;
5541               continue;
5542             }
5543         }
5544
5545       /* We've now determined that this enumerated literal isn't
5546          handled by the case labels of the switch statement.  */
5547
5548       /* If the switch expression is a constant, we only really care
5549          about whether that constant is handled by the switch.  */
5550       if (cond && tree_int_cst_compare (cond, value))
5551         continue;
5552
5553       /* If there is a default_node, the only relevant option is
5554          Wswitch-enum.  Otherwise, if both are enabled then we prefer
5555          to warn using -Wswitch because -Wswitch is enabled by -Wall
5556          while -Wswitch-enum is explicit.  */
5557       warning_at (switch_location,
5558                   (default_node || !warn_switch
5559                    ? OPT_Wswitch_enum
5560                    : OPT_Wswitch),
5561                   "enumeration value %qE not handled in switch",
5562                   TREE_PURPOSE (chain));
5563     }
5564
5565   /* Warn if there are case expressions that don't correspond to
5566      enumerators.  This can occur since C and C++ don't enforce
5567      type-checking of assignments to enumeration variables.
5568
5569      The time complexity here is now always O(N) worst case, since
5570      we should have marked both the lower bound and upper bound of
5571      every disjoint case label, with CASE_LOW_SEEN and CASE_HIGH_SEEN
5572      above.  This scan also resets those fields.  */
5573
5574   splay_tree_foreach (cases, match_case_to_enum, type);
5575 }
5576
5577 /* Finish an expression taking the address of LABEL (an
5578    IDENTIFIER_NODE).  Returns an expression for the address.
5579
5580    LOC is the location for the expression returned.  */
5581
5582 tree
5583 finish_label_address_expr (tree label, location_t loc)
5584 {
5585   tree result;
5586
5587   pedwarn (input_location, OPT_pedantic, "taking the address of a label is non-standard");
5588
5589   if (label == error_mark_node)
5590     return error_mark_node;
5591
5592   label = lookup_label (label);
5593   if (label == NULL_TREE)
5594     result = null_pointer_node;
5595   else
5596     {
5597       TREE_USED (label) = 1;
5598       result = build1 (ADDR_EXPR, ptr_type_node, label);
5599       /* The current function in not necessarily uninlinable.
5600          Computed gotos are incompatible with inlining, but the value
5601          here could be used only in a diagnostic, for example.  */
5602       protected_set_expr_location (result, loc);
5603     }
5604
5605   return result;
5606 }
5607 \f
5608
5609 /* Given a boolean expression ARG, return a tree representing an increment
5610    or decrement (as indicated by CODE) of ARG.  The front end must check for
5611    invalid cases (e.g., decrement in C++).  */
5612 tree
5613 boolean_increment (enum tree_code code, tree arg)
5614 {
5615   tree val;
5616   tree true_res = build_int_cst (TREE_TYPE (arg), 1);
5617
5618   arg = stabilize_reference (arg);
5619   switch (code)
5620     {
5621     case PREINCREMENT_EXPR:
5622       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
5623       break;
5624     case POSTINCREMENT_EXPR:
5625       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
5626       arg = save_expr (arg);
5627       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
5628       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
5629       break;
5630     case PREDECREMENT_EXPR:
5631       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
5632                     invert_truthvalue (arg));
5633       break;
5634     case POSTDECREMENT_EXPR:
5635       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
5636                     invert_truthvalue (arg));
5637       arg = save_expr (arg);
5638       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
5639       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
5640       break;
5641     default:
5642       gcc_unreachable ();
5643     }
5644   TREE_SIDE_EFFECTS (val) = 1;
5645   return val;
5646 }
5647 \f
5648 /* Built-in macros for stddef.h and stdint.h, that require macros
5649    defined in this file.  */
5650 void
5651 c_stddef_cpp_builtins(void)
5652 {
5653   builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0);
5654   builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0);
5655   builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0);
5656   builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0);
5657   builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0);
5658   builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0);
5659   builtin_define_with_value ("__CHAR16_TYPE__", CHAR16_TYPE, 0);
5660   builtin_define_with_value ("__CHAR32_TYPE__", CHAR32_TYPE, 0);
5661   if (SIG_ATOMIC_TYPE)
5662     builtin_define_with_value ("__SIG_ATOMIC_TYPE__", SIG_ATOMIC_TYPE, 0);
5663   if (INT8_TYPE)
5664     builtin_define_with_value ("__INT8_TYPE__", INT8_TYPE, 0);
5665   if (INT16_TYPE)
5666     builtin_define_with_value ("__INT16_TYPE__", INT16_TYPE, 0);
5667   if (INT32_TYPE)
5668     builtin_define_with_value ("__INT32_TYPE__", INT32_TYPE, 0);
5669   if (INT64_TYPE)
5670     builtin_define_with_value ("__INT64_TYPE__", INT64_TYPE, 0);
5671   if (UINT8_TYPE)
5672     builtin_define_with_value ("__UINT8_TYPE__", UINT8_TYPE, 0);
5673   if (UINT16_TYPE)
5674     builtin_define_with_value ("__UINT16_TYPE__", UINT16_TYPE, 0);
5675   if (UINT32_TYPE)
5676     builtin_define_with_value ("__UINT32_TYPE__", UINT32_TYPE, 0);
5677   if (UINT64_TYPE)
5678     builtin_define_with_value ("__UINT64_TYPE__", UINT64_TYPE, 0);
5679   if (INT_LEAST8_TYPE)
5680     builtin_define_with_value ("__INT_LEAST8_TYPE__", INT_LEAST8_TYPE, 0);
5681   if (INT_LEAST16_TYPE)
5682     builtin_define_with_value ("__INT_LEAST16_TYPE__", INT_LEAST16_TYPE, 0);
5683   if (INT_LEAST32_TYPE)
5684     builtin_define_with_value ("__INT_LEAST32_TYPE__", INT_LEAST32_TYPE, 0);
5685   if (INT_LEAST64_TYPE)
5686     builtin_define_with_value ("__INT_LEAST64_TYPE__", INT_LEAST64_TYPE, 0);
5687   if (UINT_LEAST8_TYPE)
5688     builtin_define_with_value ("__UINT_LEAST8_TYPE__", UINT_LEAST8_TYPE, 0);
5689   if (UINT_LEAST16_TYPE)
5690     builtin_define_with_value ("__UINT_LEAST16_TYPE__", UINT_LEAST16_TYPE, 0);
5691   if (UINT_LEAST32_TYPE)
5692     builtin_define_with_value ("__UINT_LEAST32_TYPE__", UINT_LEAST32_TYPE, 0);
5693   if (UINT_LEAST64_TYPE)
5694     builtin_define_with_value ("__UINT_LEAST64_TYPE__", UINT_LEAST64_TYPE, 0);
5695   if (INT_FAST8_TYPE)
5696     builtin_define_with_value ("__INT_FAST8_TYPE__", INT_FAST8_TYPE, 0);
5697   if (INT_FAST16_TYPE)
5698     builtin_define_with_value ("__INT_FAST16_TYPE__", INT_FAST16_TYPE, 0);
5699   if (INT_FAST32_TYPE)
5700     builtin_define_with_value ("__INT_FAST32_TYPE__", INT_FAST32_TYPE, 0);
5701   if (INT_FAST64_TYPE)
5702     builtin_define_with_value ("__INT_FAST64_TYPE__", INT_FAST64_TYPE, 0);
5703   if (UINT_FAST8_TYPE)
5704     builtin_define_with_value ("__UINT_FAST8_TYPE__", UINT_FAST8_TYPE, 0);
5705   if (UINT_FAST16_TYPE)
5706     builtin_define_with_value ("__UINT_FAST16_TYPE__", UINT_FAST16_TYPE, 0);
5707   if (UINT_FAST32_TYPE)
5708     builtin_define_with_value ("__UINT_FAST32_TYPE__", UINT_FAST32_TYPE, 0);
5709   if (UINT_FAST64_TYPE)
5710     builtin_define_with_value ("__UINT_FAST64_TYPE__", UINT_FAST64_TYPE, 0);
5711   if (INTPTR_TYPE)
5712     builtin_define_with_value ("__INTPTR_TYPE__", INTPTR_TYPE, 0);
5713   if (UINTPTR_TYPE)
5714     builtin_define_with_value ("__UINTPTR_TYPE__", UINTPTR_TYPE, 0);
5715 }
5716
5717 static void
5718 c_init_attributes (void)
5719 {
5720   /* Fill in the built_in_attributes array.  */
5721 #define DEF_ATTR_NULL_TREE(ENUM)                                \
5722   built_in_attributes[(int) ENUM] = NULL_TREE;
5723 #define DEF_ATTR_INT(ENUM, VALUE)                               \
5724   built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
5725 #define DEF_ATTR_IDENT(ENUM, STRING)                            \
5726   built_in_attributes[(int) ENUM] = get_identifier (STRING);
5727 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
5728   built_in_attributes[(int) ENUM]                       \
5729     = tree_cons (built_in_attributes[(int) PURPOSE],    \
5730                  built_in_attributes[(int) VALUE],      \
5731                  built_in_attributes[(int) CHAIN]);
5732 #include "builtin-attrs.def"
5733 #undef DEF_ATTR_NULL_TREE
5734 #undef DEF_ATTR_INT
5735 #undef DEF_ATTR_IDENT
5736 #undef DEF_ATTR_TREE_LIST
5737 }
5738
5739 /* Attribute handlers common to C front ends.  */
5740
5741 /* Handle a "packed" attribute; arguments as in
5742    struct attribute_spec.handler.  */
5743
5744 static tree
5745 handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5746                          int flags, bool *no_add_attrs)
5747 {
5748   if (TYPE_P (*node))
5749     {
5750       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5751         *node = build_variant_type_copy (*node);
5752       TYPE_PACKED (*node) = 1;
5753     }
5754   else if (TREE_CODE (*node) == FIELD_DECL)
5755     {
5756       if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT
5757           /* Still pack bitfields.  */
5758           && ! DECL_INITIAL (*node))
5759         warning (OPT_Wattributes,
5760                  "%qE attribute ignored for field of type %qT",
5761                  name, TREE_TYPE (*node));
5762       else
5763         DECL_PACKED (*node) = 1;
5764     }
5765   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
5766      used for DECL_REGISTER.  It wouldn't mean anything anyway.
5767      We can't set DECL_PACKED on the type of a TYPE_DECL, because
5768      that changes what the typedef is typing.  */
5769   else
5770     {
5771       warning (OPT_Wattributes, "%qE attribute ignored", name);
5772       *no_add_attrs = true;
5773     }
5774
5775   return NULL_TREE;
5776 }
5777
5778 /* Handle a "nocommon" attribute; arguments as in
5779    struct attribute_spec.handler.  */
5780
5781 static tree
5782 handle_nocommon_attribute (tree *node, tree name,
5783                            tree ARG_UNUSED (args),
5784                            int ARG_UNUSED (flags), bool *no_add_attrs)
5785 {
5786   if (TREE_CODE (*node) == VAR_DECL)
5787     DECL_COMMON (*node) = 0;
5788   else
5789     {
5790       warning (OPT_Wattributes, "%qE attribute ignored", name);
5791       *no_add_attrs = true;
5792     }
5793
5794   return NULL_TREE;
5795 }
5796
5797 /* Handle a "common" attribute; arguments as in
5798    struct attribute_spec.handler.  */
5799
5800 static tree
5801 handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5802                          int ARG_UNUSED (flags), bool *no_add_attrs)
5803 {
5804   if (TREE_CODE (*node) == VAR_DECL)
5805     DECL_COMMON (*node) = 1;
5806   else
5807     {
5808       warning (OPT_Wattributes, "%qE attribute ignored", name);
5809       *no_add_attrs = true;
5810     }
5811
5812   return NULL_TREE;
5813 }
5814
5815 /* Handle a "noreturn" attribute; arguments as in
5816    struct attribute_spec.handler.  */
5817
5818 static tree
5819 handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5820                            int ARG_UNUSED (flags), bool *no_add_attrs)
5821 {
5822   tree type = TREE_TYPE (*node);
5823
5824   /* See FIXME comment in c_common_attribute_table.  */
5825   if (TREE_CODE (*node) == FUNCTION_DECL)
5826     TREE_THIS_VOLATILE (*node) = 1;
5827   else if (TREE_CODE (type) == POINTER_TYPE
5828            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
5829     TREE_TYPE (*node)
5830       = build_pointer_type
5831         (build_type_variant (TREE_TYPE (type),
5832                              TYPE_READONLY (TREE_TYPE (type)), 1));
5833   else
5834     {
5835       warning (OPT_Wattributes, "%qE attribute ignored", name);
5836       *no_add_attrs = true;
5837     }
5838
5839   return NULL_TREE;
5840 }
5841
5842 /* Handle a "hot" and attribute; arguments as in
5843    struct attribute_spec.handler.  */
5844
5845 static tree
5846 handle_hot_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5847                       int ARG_UNUSED (flags), bool *no_add_attrs)
5848 {
5849   if (TREE_CODE (*node) == FUNCTION_DECL)
5850     {
5851       if (lookup_attribute ("cold", DECL_ATTRIBUTES (*node)) != NULL)
5852         {
5853           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
5854                    name, "cold");
5855           *no_add_attrs = true;
5856         }
5857       /* Most of the rest of the hot processing is done later with
5858          lookup_attribute.  */
5859     }
5860   else
5861     {
5862       warning (OPT_Wattributes, "%qE attribute ignored", name);
5863       *no_add_attrs = true;
5864     }
5865
5866   return NULL_TREE;
5867 }
5868 /* Handle a "cold" and attribute; arguments as in
5869    struct attribute_spec.handler.  */
5870
5871 static tree
5872 handle_cold_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5873                        int ARG_UNUSED (flags), bool *no_add_attrs)
5874 {
5875   if (TREE_CODE (*node) == FUNCTION_DECL)
5876     {
5877       if (lookup_attribute ("hot", DECL_ATTRIBUTES (*node)) != NULL)
5878         {
5879           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
5880                    name, "hot");
5881           *no_add_attrs = true;
5882         }
5883       /* Most of the rest of the cold processing is done later with
5884          lookup_attribute.  */
5885     }
5886   else
5887     {
5888       warning (OPT_Wattributes, "%qE attribute ignored", name);
5889       *no_add_attrs = true;
5890     }
5891
5892   return NULL_TREE;
5893 }
5894
5895 /* Handle a "noinline" attribute; arguments as in
5896    struct attribute_spec.handler.  */
5897
5898 static tree
5899 handle_noinline_attribute (tree *node, tree name,
5900                            tree ARG_UNUSED (args),
5901                            int ARG_UNUSED (flags), bool *no_add_attrs)
5902 {
5903   if (TREE_CODE (*node) == FUNCTION_DECL)
5904     DECL_UNINLINABLE (*node) = 1;
5905   else
5906     {
5907       warning (OPT_Wattributes, "%qE attribute ignored", name);
5908       *no_add_attrs = true;
5909     }
5910
5911   return NULL_TREE;
5912 }
5913
5914 /* Handle a "always_inline" attribute; arguments as in
5915    struct attribute_spec.handler.  */
5916
5917 static tree
5918 handle_always_inline_attribute (tree *node, tree name,
5919                                 tree ARG_UNUSED (args),
5920                                 int ARG_UNUSED (flags),
5921                                 bool *no_add_attrs)
5922 {
5923   if (TREE_CODE (*node) == FUNCTION_DECL)
5924     {
5925       /* Set the attribute and mark it for disregarding inline
5926          limits.  */
5927       DECL_DISREGARD_INLINE_LIMITS (*node) = 1;
5928     }
5929   else
5930     {
5931       warning (OPT_Wattributes, "%qE attribute ignored", name);
5932       *no_add_attrs = true;
5933     }
5934
5935   return NULL_TREE;
5936 }
5937
5938 /* Handle a "gnu_inline" attribute; arguments as in
5939    struct attribute_spec.handler.  */
5940
5941 static tree
5942 handle_gnu_inline_attribute (tree *node, tree name,
5943                              tree ARG_UNUSED (args),
5944                              int ARG_UNUSED (flags),
5945                              bool *no_add_attrs)
5946 {
5947   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
5948     {
5949       /* Do nothing else, just set the attribute.  We'll get at
5950          it later with lookup_attribute.  */
5951     }
5952   else
5953     {
5954       warning (OPT_Wattributes, "%qE attribute ignored", name);
5955       *no_add_attrs = true;
5956     }
5957
5958   return NULL_TREE;
5959 }
5960
5961 /* Handle an "artificial" attribute; arguments as in
5962    struct attribute_spec.handler.  */
5963
5964 static tree
5965 handle_artificial_attribute (tree *node, tree name,
5966                              tree ARG_UNUSED (args),
5967                              int ARG_UNUSED (flags),
5968                              bool *no_add_attrs)
5969 {
5970   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
5971     {
5972       /* Do nothing else, just set the attribute.  We'll get at
5973          it later with lookup_attribute.  */
5974     }
5975   else
5976     {
5977       warning (OPT_Wattributes, "%qE attribute ignored", name);
5978       *no_add_attrs = true;
5979     }
5980
5981   return NULL_TREE;
5982 }
5983
5984 /* Handle a "flatten" attribute; arguments as in
5985    struct attribute_spec.handler.  */
5986
5987 static tree
5988 handle_flatten_attribute (tree *node, tree name,
5989                           tree args ATTRIBUTE_UNUSED,
5990                           int flags ATTRIBUTE_UNUSED, bool *no_add_attrs)
5991 {
5992   if (TREE_CODE (*node) == FUNCTION_DECL)
5993     /* Do nothing else, just set the attribute.  We'll get at
5994        it later with lookup_attribute.  */
5995     ;
5996   else
5997     {
5998       warning (OPT_Wattributes, "%qE attribute ignored", name);
5999       *no_add_attrs = true;
6000     }
6001
6002   return NULL_TREE;
6003 }
6004
6005 /* Handle a "warning" or "error" attribute; arguments as in
6006    struct attribute_spec.handler.  */
6007
6008 static tree
6009 handle_error_attribute (tree *node, tree name, tree args,
6010                         int ARG_UNUSED (flags), bool *no_add_attrs)
6011 {
6012   if (TREE_CODE (*node) == FUNCTION_DECL
6013       || TREE_CODE (TREE_VALUE (args)) == STRING_CST)
6014     /* Do nothing else, just set the attribute.  We'll get at
6015        it later with lookup_attribute.  */
6016     ;
6017   else
6018     {
6019       warning (OPT_Wattributes, "%qE attribute ignored", name);
6020       *no_add_attrs = true;
6021     }
6022
6023   return NULL_TREE;
6024 }
6025
6026 /* Handle a "used" attribute; arguments as in
6027    struct attribute_spec.handler.  */
6028
6029 static tree
6030 handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
6031                        int ARG_UNUSED (flags), bool *no_add_attrs)
6032 {
6033   tree node = *pnode;
6034
6035   if (TREE_CODE (node) == FUNCTION_DECL
6036       || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node)))
6037     {
6038       TREE_USED (node) = 1;
6039       DECL_PRESERVE_P (node) = 1;
6040     }
6041   else
6042     {
6043       warning (OPT_Wattributes, "%qE attribute ignored", name);
6044       *no_add_attrs = true;
6045     }
6046
6047   return NULL_TREE;
6048 }
6049
6050 /* Handle a "unused" attribute; arguments as in
6051    struct attribute_spec.handler.  */
6052
6053 static tree
6054 handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6055                          int flags, bool *no_add_attrs)
6056 {
6057   if (DECL_P (*node))
6058     {
6059       tree decl = *node;
6060
6061       if (TREE_CODE (decl) == PARM_DECL
6062           || TREE_CODE (decl) == VAR_DECL
6063           || TREE_CODE (decl) == FUNCTION_DECL
6064           || TREE_CODE (decl) == LABEL_DECL
6065           || TREE_CODE (decl) == TYPE_DECL)
6066         TREE_USED (decl) = 1;
6067       else
6068         {
6069           warning (OPT_Wattributes, "%qE attribute ignored", name);
6070           *no_add_attrs = true;
6071         }
6072     }
6073   else
6074     {
6075       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6076         *node = build_variant_type_copy (*node);
6077       TREE_USED (*node) = 1;
6078     }
6079
6080   return NULL_TREE;
6081 }
6082
6083 /* Handle a "externally_visible" attribute; arguments as in
6084    struct attribute_spec.handler.  */
6085
6086 static tree
6087 handle_externally_visible_attribute (tree *pnode, tree name,
6088                                      tree ARG_UNUSED (args),
6089                                      int ARG_UNUSED (flags),
6090                                      bool *no_add_attrs)
6091 {
6092   tree node = *pnode;
6093
6094   if (TREE_CODE (node) == FUNCTION_DECL || TREE_CODE (node) == VAR_DECL)
6095     {
6096       if ((!TREE_STATIC (node) && TREE_CODE (node) != FUNCTION_DECL
6097            && !DECL_EXTERNAL (node)) || !TREE_PUBLIC (node))
6098         {
6099           warning (OPT_Wattributes,
6100                    "%qE attribute have effect only on public objects", name);
6101           *no_add_attrs = true;
6102         }
6103     }
6104   else
6105     {
6106       warning (OPT_Wattributes, "%qE attribute ignored", name);
6107       *no_add_attrs = true;
6108     }
6109
6110   return NULL_TREE;
6111 }
6112
6113 /* Handle a "const" attribute; arguments as in
6114    struct attribute_spec.handler.  */
6115
6116 static tree
6117 handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6118                         int ARG_UNUSED (flags), bool *no_add_attrs)
6119 {
6120   tree type = TREE_TYPE (*node);
6121
6122   /* See FIXME comment on noreturn in c_common_attribute_table.  */
6123   if (TREE_CODE (*node) == FUNCTION_DECL)
6124     TREE_READONLY (*node) = 1;
6125   else if (TREE_CODE (type) == POINTER_TYPE
6126            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
6127     TREE_TYPE (*node)
6128       = build_pointer_type
6129         (build_type_variant (TREE_TYPE (type), 1,
6130                              TREE_THIS_VOLATILE (TREE_TYPE (type))));
6131   else
6132     {
6133       warning (OPT_Wattributes, "%qE attribute ignored", name);
6134       *no_add_attrs = true;
6135     }
6136
6137   return NULL_TREE;
6138 }
6139
6140 /* Handle a "transparent_union" attribute; arguments as in
6141    struct attribute_spec.handler.  */
6142
6143 static tree
6144 handle_transparent_union_attribute (tree *node, tree name,
6145                                     tree ARG_UNUSED (args), int flags,
6146                                     bool *no_add_attrs)
6147 {
6148   tree type;
6149
6150   *no_add_attrs = true;
6151
6152   if (TREE_CODE (*node) == TYPE_DECL)
6153     node = &TREE_TYPE (*node);
6154   type = *node;
6155
6156   if (TREE_CODE (type) == UNION_TYPE)
6157     {
6158       /* When IN_PLACE is set, leave the check for FIELDS and MODE to
6159          the code in finish_struct.  */
6160       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6161         {
6162           if (TYPE_FIELDS (type) == NULL_TREE
6163               || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type)))
6164             goto ignored;
6165
6166           /* A type variant isn't good enough, since we don't a cast
6167              to such a type removed as a no-op.  */
6168           *node = type = build_duplicate_type (type);
6169         }
6170
6171       TYPE_TRANSPARENT_UNION (type) = 1;
6172       return NULL_TREE;
6173     }
6174
6175  ignored:
6176   warning (OPT_Wattributes, "%qE attribute ignored", name);
6177   return NULL_TREE;
6178 }
6179
6180 /* Subroutine of handle_{con,de}structor_attribute.  Evaluate ARGS to
6181    get the requested priority for a constructor or destructor,
6182    possibly issuing diagnostics for invalid or reserved
6183    priorities.  */
6184
6185 static priority_type
6186 get_priority (tree args, bool is_destructor)
6187 {
6188   HOST_WIDE_INT pri;
6189   tree arg;
6190
6191   if (!args)
6192     return DEFAULT_INIT_PRIORITY;
6193
6194   if (!SUPPORTS_INIT_PRIORITY)
6195     {
6196       if (is_destructor)
6197         error ("destructor priorities are not supported");
6198       else
6199         error ("constructor priorities are not supported");
6200       return DEFAULT_INIT_PRIORITY;
6201     }
6202
6203   arg = TREE_VALUE (args);
6204   if (!host_integerp (arg, /*pos=*/0)
6205       || !INTEGRAL_TYPE_P (TREE_TYPE (arg)))
6206     goto invalid;
6207
6208   pri = tree_low_cst (TREE_VALUE (args), /*pos=*/0);
6209   if (pri < 0 || pri > MAX_INIT_PRIORITY)
6210     goto invalid;
6211
6212   if (pri <= MAX_RESERVED_INIT_PRIORITY)
6213     {
6214       if (is_destructor)
6215         warning (0,
6216                  "destructor priorities from 0 to %d are reserved "
6217                  "for the implementation",
6218                  MAX_RESERVED_INIT_PRIORITY);
6219       else
6220         warning (0,
6221                  "constructor priorities from 0 to %d are reserved "
6222                  "for the implementation",
6223                  MAX_RESERVED_INIT_PRIORITY);
6224     }
6225   return pri;
6226
6227  invalid:
6228   if (is_destructor)
6229     error ("destructor priorities must be integers from 0 to %d inclusive",
6230            MAX_INIT_PRIORITY);
6231   else
6232     error ("constructor priorities must be integers from 0 to %d inclusive",
6233            MAX_INIT_PRIORITY);
6234   return DEFAULT_INIT_PRIORITY;
6235 }
6236
6237 /* Handle a "constructor" attribute; arguments as in
6238    struct attribute_spec.handler.  */
6239
6240 static tree
6241 handle_constructor_attribute (tree *node, tree name, tree args,
6242                               int ARG_UNUSED (flags),
6243                               bool *no_add_attrs)
6244 {
6245   tree decl = *node;
6246   tree type = TREE_TYPE (decl);
6247
6248   if (TREE_CODE (decl) == FUNCTION_DECL
6249       && TREE_CODE (type) == FUNCTION_TYPE
6250       && decl_function_context (decl) == 0)
6251     {
6252       priority_type priority;
6253       DECL_STATIC_CONSTRUCTOR (decl) = 1;
6254       priority = get_priority (args, /*is_destructor=*/false);
6255       SET_DECL_INIT_PRIORITY (decl, priority);
6256       TREE_USED (decl) = 1;
6257     }
6258   else
6259     {
6260       warning (OPT_Wattributes, "%qE attribute ignored", name);
6261       *no_add_attrs = true;
6262     }
6263
6264   return NULL_TREE;
6265 }
6266
6267 /* Handle a "destructor" attribute; arguments as in
6268    struct attribute_spec.handler.  */
6269
6270 static tree
6271 handle_destructor_attribute (tree *node, tree name, tree args,
6272                              int ARG_UNUSED (flags),
6273                              bool *no_add_attrs)
6274 {
6275   tree decl = *node;
6276   tree type = TREE_TYPE (decl);
6277
6278   if (TREE_CODE (decl) == FUNCTION_DECL
6279       && TREE_CODE (type) == FUNCTION_TYPE
6280       && decl_function_context (decl) == 0)
6281     {
6282       priority_type priority;
6283       DECL_STATIC_DESTRUCTOR (decl) = 1;
6284       priority = get_priority (args, /*is_destructor=*/true);
6285       SET_DECL_FINI_PRIORITY (decl, priority);
6286       TREE_USED (decl) = 1;
6287     }
6288   else
6289     {
6290       warning (OPT_Wattributes, "%qE attribute ignored", name);
6291       *no_add_attrs = true;
6292     }
6293
6294   return NULL_TREE;
6295 }
6296
6297 /* Handle a "mode" attribute; arguments as in
6298    struct attribute_spec.handler.  */
6299
6300 static tree
6301 handle_mode_attribute (tree *node, tree name, tree args,
6302                        int ARG_UNUSED (flags), bool *no_add_attrs)
6303 {
6304   tree type = *node;
6305   tree ident = TREE_VALUE (args);
6306
6307   *no_add_attrs = true;
6308
6309   if (TREE_CODE (ident) != IDENTIFIER_NODE)
6310     warning (OPT_Wattributes, "%qE attribute ignored", name);
6311   else
6312     {
6313       int j;
6314       const char *p = IDENTIFIER_POINTER (ident);
6315       int len = strlen (p);
6316       enum machine_mode mode = VOIDmode;
6317       tree typefm;
6318       bool valid_mode;
6319
6320       if (len > 4 && p[0] == '_' && p[1] == '_'
6321           && p[len - 1] == '_' && p[len - 2] == '_')
6322         {
6323           char *newp = (char *) alloca (len - 1);
6324
6325           strcpy (newp, &p[2]);
6326           newp[len - 4] = '\0';
6327           p = newp;
6328         }
6329
6330       /* Change this type to have a type with the specified mode.
6331          First check for the special modes.  */
6332       if (!strcmp (p, "byte"))
6333         mode = byte_mode;
6334       else if (!strcmp (p, "word"))
6335         mode = word_mode;
6336       else if (!strcmp (p, "pointer"))
6337         mode = ptr_mode;
6338       else if (!strcmp (p, "libgcc_cmp_return"))
6339         mode = targetm.libgcc_cmp_return_mode ();
6340       else if (!strcmp (p, "libgcc_shift_count"))
6341         mode = targetm.libgcc_shift_count_mode ();
6342       else if (!strcmp (p, "unwind_word"))
6343         mode = targetm.unwind_word_mode ();
6344       else
6345         for (j = 0; j < NUM_MACHINE_MODES; j++)
6346           if (!strcmp (p, GET_MODE_NAME (j)))
6347             {
6348               mode = (enum machine_mode) j;
6349               break;
6350             }
6351
6352       if (mode == VOIDmode)
6353         {
6354           error ("unknown machine mode %qE", ident);
6355           return NULL_TREE;
6356         }
6357
6358       valid_mode = false;
6359       switch (GET_MODE_CLASS (mode))
6360         {
6361         case MODE_INT:
6362         case MODE_PARTIAL_INT:
6363         case MODE_FLOAT:
6364         case MODE_DECIMAL_FLOAT:
6365         case MODE_FRACT:
6366         case MODE_UFRACT:
6367         case MODE_ACCUM:
6368         case MODE_UACCUM:
6369           valid_mode = targetm.scalar_mode_supported_p (mode);
6370           break;
6371
6372         case MODE_COMPLEX_INT:
6373         case MODE_COMPLEX_FLOAT:
6374           valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode));
6375           break;
6376
6377         case MODE_VECTOR_INT:
6378         case MODE_VECTOR_FLOAT:
6379         case MODE_VECTOR_FRACT:
6380         case MODE_VECTOR_UFRACT:
6381         case MODE_VECTOR_ACCUM:
6382         case MODE_VECTOR_UACCUM:
6383           warning (OPT_Wattributes, "specifying vector types with "
6384                    "__attribute__ ((mode)) is deprecated");
6385           warning (OPT_Wattributes,
6386                    "use __attribute__ ((vector_size)) instead");
6387           valid_mode = vector_mode_valid_p (mode);
6388           break;
6389
6390         default:
6391           break;
6392         }
6393       if (!valid_mode)
6394         {
6395           error ("unable to emulate %qs", p);
6396           return NULL_TREE;
6397         }
6398
6399       if (POINTER_TYPE_P (type))
6400         {
6401           tree (*fn)(tree, enum machine_mode, bool);
6402
6403           if (!targetm.valid_pointer_mode (mode))
6404             {
6405               error ("invalid pointer mode %qs", p);
6406               return NULL_TREE;
6407             }
6408
6409           if (TREE_CODE (type) == POINTER_TYPE)
6410             fn = build_pointer_type_for_mode;
6411           else
6412             fn = build_reference_type_for_mode;
6413           typefm = fn (TREE_TYPE (type), mode, false);
6414         }
6415       else
6416         {
6417           /* For fixed-point modes, we need to test if the signness of type
6418              and the machine mode are consistent.  */
6419           if (ALL_FIXED_POINT_MODE_P (mode)
6420               && TYPE_UNSIGNED (type) != UNSIGNED_FIXED_POINT_MODE_P (mode))
6421             {
6422               error ("signness of type and machine mode %qs don't match", p);
6423               return NULL_TREE;
6424             }
6425           /* For fixed-point modes, we need to pass saturating info.  */
6426           typefm = lang_hooks.types.type_for_mode (mode,
6427                         ALL_FIXED_POINT_MODE_P (mode) ? TYPE_SATURATING (type)
6428                                                       : TYPE_UNSIGNED (type));
6429         }
6430
6431       if (typefm == NULL_TREE)
6432         {
6433           error ("no data type for mode %qs", p);
6434           return NULL_TREE;
6435         }
6436       else if (TREE_CODE (type) == ENUMERAL_TYPE)
6437         {
6438           /* For enumeral types, copy the precision from the integer
6439              type returned above.  If not an INTEGER_TYPE, we can't use
6440              this mode for this type.  */
6441           if (TREE_CODE (typefm) != INTEGER_TYPE)
6442             {
6443               error ("cannot use mode %qs for enumeral types", p);
6444               return NULL_TREE;
6445             }
6446
6447           if (flags & ATTR_FLAG_TYPE_IN_PLACE)
6448             {
6449               TYPE_PRECISION (type) = TYPE_PRECISION (typefm);
6450               typefm = type;
6451             }
6452           else
6453             {
6454               /* We cannot build a type variant, as there's code that assumes
6455                  that TYPE_MAIN_VARIANT has the same mode.  This includes the
6456                  debug generators.  Instead, create a subrange type.  This
6457                  results in all of the enumeral values being emitted only once
6458                  in the original, and the subtype gets them by reference.  */
6459               if (TYPE_UNSIGNED (type))
6460                 typefm = make_unsigned_type (TYPE_PRECISION (typefm));
6461               else
6462                 typefm = make_signed_type (TYPE_PRECISION (typefm));
6463               TREE_TYPE (typefm) = type;
6464             }
6465         }
6466       else if (VECTOR_MODE_P (mode)
6467                ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm))
6468                : TREE_CODE (type) != TREE_CODE (typefm))
6469         {
6470           error ("mode %qs applied to inappropriate type", p);
6471           return NULL_TREE;
6472         }
6473
6474       *node = typefm;
6475     }
6476
6477   return NULL_TREE;
6478 }
6479
6480 /* Handle a "section" attribute; arguments as in
6481    struct attribute_spec.handler.  */
6482
6483 static tree
6484 handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6485                           int ARG_UNUSED (flags), bool *no_add_attrs)
6486 {
6487   tree decl = *node;
6488
6489   if (targetm.have_named_sections)
6490     {
6491       user_defined_section_attribute = true;
6492
6493       if ((TREE_CODE (decl) == FUNCTION_DECL
6494            || TREE_CODE (decl) == VAR_DECL)
6495           && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
6496         {
6497           if (TREE_CODE (decl) == VAR_DECL
6498               && current_function_decl != NULL_TREE
6499               && !TREE_STATIC (decl))
6500             {
6501               error ("%Jsection attribute cannot be specified for "
6502                      "local variables", decl);
6503               *no_add_attrs = true;
6504             }
6505
6506           /* The decl may have already been given a section attribute
6507              from a previous declaration.  Ensure they match.  */
6508           else if (DECL_SECTION_NAME (decl) != NULL_TREE
6509                    && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
6510                               TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
6511             {
6512               error ("section of %q+D conflicts with previous declaration",
6513                      *node);
6514               *no_add_attrs = true;
6515             }
6516           else if (TREE_CODE (decl) == VAR_DECL
6517                    && !targetm.have_tls && targetm.emutls.tmpl_section
6518                    && DECL_THREAD_LOCAL_P (decl))
6519             {
6520               error ("section of %q+D cannot be overridden", *node);
6521               *no_add_attrs = true;
6522             }
6523           else
6524             DECL_SECTION_NAME (decl) = TREE_VALUE (args);
6525         }
6526       else
6527         {
6528           error ("section attribute not allowed for %q+D", *node);
6529           *no_add_attrs = true;
6530         }
6531     }
6532   else
6533     {
6534       error ("%Jsection attributes are not supported for this target", *node);
6535       *no_add_attrs = true;
6536     }
6537
6538   return NULL_TREE;
6539 }
6540
6541 /* Handle a "aligned" attribute; arguments as in
6542    struct attribute_spec.handler.  */
6543
6544 static tree
6545 handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6546                           int flags, bool *no_add_attrs)
6547 {
6548   tree decl = NULL_TREE;
6549   tree *type = NULL;
6550   int is_type = 0;
6551   tree align_expr = (args ? TREE_VALUE (args)
6552                      : size_int (ATTRIBUTE_ALIGNED_VALUE / BITS_PER_UNIT));
6553   int i;
6554
6555   if (DECL_P (*node))
6556     {
6557       decl = *node;
6558       type = &TREE_TYPE (decl);
6559       is_type = TREE_CODE (*node) == TYPE_DECL;
6560     }
6561   else if (TYPE_P (*node))
6562     type = node, is_type = 1;
6563
6564   if (TREE_CODE (align_expr) != INTEGER_CST)
6565     {
6566       error ("requested alignment is not a constant");
6567       *no_add_attrs = true;
6568     }
6569   else if ((i = tree_log2 (align_expr)) == -1)
6570     {
6571       error ("requested alignment is not a power of 2");
6572       *no_add_attrs = true;
6573     }
6574   else if (i >= HOST_BITS_PER_INT - BITS_PER_UNIT_LOG)
6575     {
6576       error ("requested alignment is too large");
6577       *no_add_attrs = true;
6578     }
6579   else if (is_type)
6580     {
6581       /* If we have a TYPE_DECL, then copy the type, so that we
6582          don't accidentally modify a builtin type.  See pushdecl.  */
6583       if (decl && TREE_TYPE (decl) != error_mark_node
6584           && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
6585         {
6586           tree tt = TREE_TYPE (decl);
6587           *type = build_variant_type_copy (*type);
6588           DECL_ORIGINAL_TYPE (decl) = tt;
6589           TYPE_NAME (*type) = decl;
6590           TREE_USED (*type) = TREE_USED (decl);
6591           TREE_TYPE (decl) = *type;
6592         }
6593       else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6594         *type = build_variant_type_copy (*type);
6595
6596       TYPE_ALIGN (*type) = (1U << i) * BITS_PER_UNIT;
6597       TYPE_USER_ALIGN (*type) = 1;
6598     }
6599   else if (! VAR_OR_FUNCTION_DECL_P (decl)
6600            && TREE_CODE (decl) != FIELD_DECL)
6601     {
6602       error ("alignment may not be specified for %q+D", decl);
6603       *no_add_attrs = true;
6604     }
6605   else if (TREE_CODE (decl) == FUNCTION_DECL
6606            && DECL_ALIGN (decl) > (1U << i) * BITS_PER_UNIT)
6607     {
6608       if (DECL_USER_ALIGN (decl))
6609         error ("alignment for %q+D was previously specified as %d "
6610                "and may not be decreased", decl,
6611                DECL_ALIGN (decl) / BITS_PER_UNIT);
6612       else
6613         error ("alignment for %q+D must be at least %d", decl,
6614                DECL_ALIGN (decl) / BITS_PER_UNIT);
6615       *no_add_attrs = true;
6616     }
6617   else
6618     {
6619       DECL_ALIGN (decl) = (1U << i) * BITS_PER_UNIT;
6620       DECL_USER_ALIGN (decl) = 1;
6621     }
6622
6623   return NULL_TREE;
6624 }
6625
6626 /* Handle a "weak" attribute; arguments as in
6627    struct attribute_spec.handler.  */
6628
6629 static tree
6630 handle_weak_attribute (tree *node, tree name,
6631                        tree ARG_UNUSED (args),
6632                        int ARG_UNUSED (flags),
6633                        bool * ARG_UNUSED (no_add_attrs))
6634 {
6635   if (TREE_CODE (*node) == FUNCTION_DECL
6636       && DECL_DECLARED_INLINE_P (*node))
6637     {
6638       error ("inline function %q+D cannot be declared weak", *node);
6639       *no_add_attrs = true;
6640     }
6641   else if (TREE_CODE (*node) == FUNCTION_DECL
6642            || TREE_CODE (*node) == VAR_DECL)
6643     declare_weak (*node);
6644   else
6645     warning (OPT_Wattributes, "%qE attribute ignored", name);
6646
6647   return NULL_TREE;
6648 }
6649
6650 /* Handle an "alias" attribute; arguments as in
6651    struct attribute_spec.handler.  */
6652
6653 static tree
6654 handle_alias_attribute (tree *node, tree name, tree args,
6655                         int ARG_UNUSED (flags), bool *no_add_attrs)
6656 {
6657   tree decl = *node;
6658
6659   if (TREE_CODE (decl) != FUNCTION_DECL && TREE_CODE (decl) != VAR_DECL)
6660     {
6661       warning (OPT_Wattributes, "%qE attribute ignored", name);
6662       *no_add_attrs = true;
6663     }
6664   else if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
6665       || (TREE_CODE (decl) != FUNCTION_DECL
6666           && TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl))
6667       /* A static variable declaration is always a tentative definition,
6668          but the alias is a non-tentative definition which overrides.  */
6669       || (TREE_CODE (decl) != FUNCTION_DECL
6670           && ! TREE_PUBLIC (decl) && DECL_INITIAL (decl)))
6671     {
6672       error ("%q+D defined both normally and as an alias", decl);
6673       *no_add_attrs = true;
6674     }
6675
6676   /* Note that the very first time we process a nested declaration,
6677      decl_function_context will not be set.  Indeed, *would* never
6678      be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that
6679      we do below.  After such frobbery, pushdecl would set the context.
6680      In any case, this is never what we want.  */
6681   else if (decl_function_context (decl) == 0 && current_function_decl == NULL)
6682     {
6683       tree id;
6684
6685       id = TREE_VALUE (args);
6686       if (TREE_CODE (id) != STRING_CST)
6687         {
6688           error ("alias argument not a string");
6689           *no_add_attrs = true;
6690           return NULL_TREE;
6691         }
6692       id = get_identifier (TREE_STRING_POINTER (id));
6693       /* This counts as a use of the object pointed to.  */
6694       TREE_USED (id) = 1;
6695
6696       if (TREE_CODE (decl) == FUNCTION_DECL)
6697         DECL_INITIAL (decl) = error_mark_node;
6698       else
6699         {
6700           if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
6701             DECL_EXTERNAL (decl) = 1;
6702           else
6703             DECL_EXTERNAL (decl) = 0;
6704           TREE_STATIC (decl) = 1;
6705         }
6706     }
6707   else
6708     {
6709       warning (OPT_Wattributes, "%qE attribute ignored", name);
6710       *no_add_attrs = true;
6711     }
6712
6713   return NULL_TREE;
6714 }
6715
6716 /* Handle a "weakref" attribute; arguments as in struct
6717    attribute_spec.handler.  */
6718
6719 static tree
6720 handle_weakref_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6721                           int flags, bool *no_add_attrs)
6722 {
6723   tree attr = NULL_TREE;
6724
6725   /* We must ignore the attribute when it is associated with
6726      local-scoped decls, since attribute alias is ignored and many
6727      such symbols do not even have a DECL_WEAK field.  */
6728   if (decl_function_context (*node)
6729       || current_function_decl
6730       || (TREE_CODE (*node) != VAR_DECL && TREE_CODE (*node) != FUNCTION_DECL))
6731     {
6732       warning (OPT_Wattributes, "%qE attribute ignored", name);
6733       *no_add_attrs = true;
6734       return NULL_TREE;
6735     }
6736
6737   /* The idea here is that `weakref("name")' mutates into `weakref,
6738      alias("name")', and weakref without arguments, in turn,
6739      implicitly adds weak. */
6740
6741   if (args)
6742     {
6743       attr = tree_cons (get_identifier ("alias"), args, attr);
6744       attr = tree_cons (get_identifier ("weakref"), NULL_TREE, attr);
6745
6746       *no_add_attrs = true;
6747
6748       decl_attributes (node, attr, flags);
6749     }
6750   else
6751     {
6752       if (lookup_attribute ("alias", DECL_ATTRIBUTES (*node)))
6753         error ("%Jweakref attribute must appear before alias attribute",
6754                *node);
6755
6756       /* Can't call declare_weak because it wants this to be TREE_PUBLIC,
6757          and that isn't supported; and because it wants to add it to
6758          the list of weak decls, which isn't helpful.  */
6759       DECL_WEAK (*node) = 1;
6760     }
6761
6762   return NULL_TREE;
6763 }
6764
6765 /* Handle an "visibility" attribute; arguments as in
6766    struct attribute_spec.handler.  */
6767
6768 static tree
6769 handle_visibility_attribute (tree *node, tree name, tree args,
6770                              int ARG_UNUSED (flags),
6771                              bool *ARG_UNUSED (no_add_attrs))
6772 {
6773   tree decl = *node;
6774   tree id = TREE_VALUE (args);
6775   enum symbol_visibility vis;
6776
6777   if (TYPE_P (*node))
6778     {
6779       if (TREE_CODE (*node) == ENUMERAL_TYPE)
6780         /* OK */;
6781       else if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE)
6782         {
6783           warning (OPT_Wattributes, "%qE attribute ignored on non-class types",
6784                    name);
6785           return NULL_TREE;
6786         }
6787       else if (TYPE_FIELDS (*node))
6788         {
6789           error ("%qE attribute ignored because %qT is already defined",
6790                  name, *node);
6791           return NULL_TREE;
6792         }
6793     }
6794   else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl))
6795     {
6796       warning (OPT_Wattributes, "%qE attribute ignored", name);
6797       return NULL_TREE;
6798     }
6799
6800   if (TREE_CODE (id) != STRING_CST)
6801     {
6802       error ("visibility argument not a string");
6803       return NULL_TREE;
6804     }
6805
6806   /*  If this is a type, set the visibility on the type decl.  */
6807   if (TYPE_P (decl))
6808     {
6809       decl = TYPE_NAME (decl);
6810       if (!decl)
6811         return NULL_TREE;
6812       if (TREE_CODE (decl) == IDENTIFIER_NODE)
6813         {
6814            warning (OPT_Wattributes, "%qE attribute ignored on types",
6815                     name);
6816            return NULL_TREE;
6817         }
6818     }
6819
6820   if (strcmp (TREE_STRING_POINTER (id), "default") == 0)
6821     vis = VISIBILITY_DEFAULT;
6822   else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0)
6823     vis = VISIBILITY_INTERNAL;
6824   else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0)
6825     vis = VISIBILITY_HIDDEN;
6826   else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0)
6827     vis = VISIBILITY_PROTECTED;
6828   else
6829     {
6830       error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\"");
6831       vis = VISIBILITY_DEFAULT;
6832     }
6833
6834   if (DECL_VISIBILITY_SPECIFIED (decl)
6835       && vis != DECL_VISIBILITY (decl))
6836     {
6837       tree attributes = (TYPE_P (*node)
6838                          ? TYPE_ATTRIBUTES (*node)
6839                          : DECL_ATTRIBUTES (decl));
6840       if (lookup_attribute ("visibility", attributes))
6841         error ("%qD redeclared with different visibility", decl);
6842       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
6843                && lookup_attribute ("dllimport", attributes))
6844         error ("%qD was declared %qs which implies default visibility",
6845                decl, "dllimport");
6846       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
6847                && lookup_attribute ("dllexport", attributes))
6848         error ("%qD was declared %qs which implies default visibility",
6849                decl, "dllexport");
6850     }
6851
6852   DECL_VISIBILITY (decl) = vis;
6853   DECL_VISIBILITY_SPECIFIED (decl) = 1;
6854
6855   /* Go ahead and attach the attribute to the node as well.  This is needed
6856      so we can determine whether we have VISIBILITY_DEFAULT because the
6857      visibility was not specified, or because it was explicitly overridden
6858      from the containing scope.  */
6859
6860   return NULL_TREE;
6861 }
6862
6863 /* Determine the ELF symbol visibility for DECL, which is either a
6864    variable or a function.  It is an error to use this function if a
6865    definition of DECL is not available in this translation unit.
6866    Returns true if the final visibility has been determined by this
6867    function; false if the caller is free to make additional
6868    modifications.  */
6869
6870 bool
6871 c_determine_visibility (tree decl)
6872 {
6873   gcc_assert (TREE_CODE (decl) == VAR_DECL
6874               || TREE_CODE (decl) == FUNCTION_DECL);
6875
6876   /* If the user explicitly specified the visibility with an
6877      attribute, honor that.  DECL_VISIBILITY will have been set during
6878      the processing of the attribute.  We check for an explicit
6879      attribute, rather than just checking DECL_VISIBILITY_SPECIFIED,
6880      to distinguish the use of an attribute from the use of a "#pragma
6881      GCC visibility push(...)"; in the latter case we still want other
6882      considerations to be able to overrule the #pragma.  */
6883   if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl))
6884       || (TARGET_DLLIMPORT_DECL_ATTRIBUTES
6885           && (lookup_attribute ("dllimport", DECL_ATTRIBUTES (decl))
6886               || lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))))
6887     return true;
6888
6889   /* Set default visibility to whatever the user supplied with
6890      visibility_specified depending on #pragma GCC visibility.  */
6891   if (!DECL_VISIBILITY_SPECIFIED (decl))
6892     {
6893       if (visibility_options.inpragma
6894           || DECL_VISIBILITY (decl) != default_visibility)
6895         {
6896           DECL_VISIBILITY (decl) = default_visibility;
6897           DECL_VISIBILITY_SPECIFIED (decl) = visibility_options.inpragma;
6898           /* If visibility changed and DECL already has DECL_RTL, ensure
6899              symbol flags are updated.  */
6900           if (((TREE_CODE (decl) == VAR_DECL && TREE_STATIC (decl))
6901                || TREE_CODE (decl) == FUNCTION_DECL)
6902               && DECL_RTL_SET_P (decl))
6903             make_decl_rtl (decl);
6904         }
6905     }
6906   return false;
6907 }
6908
6909 /* Handle an "tls_model" attribute; arguments as in
6910    struct attribute_spec.handler.  */
6911
6912 static tree
6913 handle_tls_model_attribute (tree *node, tree name, tree args,
6914                             int ARG_UNUSED (flags), bool *no_add_attrs)
6915 {
6916   tree id;
6917   tree decl = *node;
6918   enum tls_model kind;
6919
6920   *no_add_attrs = true;
6921
6922   if (TREE_CODE (decl) != VAR_DECL || !DECL_THREAD_LOCAL_P (decl))
6923     {
6924       warning (OPT_Wattributes, "%qE attribute ignored", name);
6925       return NULL_TREE;
6926     }
6927
6928   kind = DECL_TLS_MODEL (decl);
6929   id = TREE_VALUE (args);
6930   if (TREE_CODE (id) != STRING_CST)
6931     {
6932       error ("tls_model argument not a string");
6933       return NULL_TREE;
6934     }
6935
6936   if (!strcmp (TREE_STRING_POINTER (id), "local-exec"))
6937     kind = TLS_MODEL_LOCAL_EXEC;
6938   else if (!strcmp (TREE_STRING_POINTER (id), "initial-exec"))
6939     kind = TLS_MODEL_INITIAL_EXEC;
6940   else if (!strcmp (TREE_STRING_POINTER (id), "local-dynamic"))
6941     kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
6942   else if (!strcmp (TREE_STRING_POINTER (id), "global-dynamic"))
6943     kind = TLS_MODEL_GLOBAL_DYNAMIC;
6944   else
6945     error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\"");
6946
6947   DECL_TLS_MODEL (decl) = kind;
6948   return NULL_TREE;
6949 }
6950
6951 /* Handle a "no_instrument_function" attribute; arguments as in
6952    struct attribute_spec.handler.  */
6953
6954 static tree
6955 handle_no_instrument_function_attribute (tree *node, tree name,
6956                                          tree ARG_UNUSED (args),
6957                                          int ARG_UNUSED (flags),
6958                                          bool *no_add_attrs)
6959 {
6960   tree decl = *node;
6961
6962   if (TREE_CODE (decl) != FUNCTION_DECL)
6963     {
6964       error ("%J%qE attribute applies only to functions", decl, name);
6965       *no_add_attrs = true;
6966     }
6967   else if (DECL_INITIAL (decl))
6968     {
6969       error ("%Jcan%'t set %qE attribute after definition", decl, name);
6970       *no_add_attrs = true;
6971     }
6972   else
6973     DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
6974
6975   return NULL_TREE;
6976 }
6977
6978 /* Handle a "malloc" attribute; arguments as in
6979    struct attribute_spec.handler.  */
6980
6981 static tree
6982 handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6983                          int ARG_UNUSED (flags), bool *no_add_attrs)
6984 {
6985   if (TREE_CODE (*node) == FUNCTION_DECL
6986       && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node))))
6987     DECL_IS_MALLOC (*node) = 1;
6988   else
6989     {
6990       warning (OPT_Wattributes, "%qE attribute ignored", name);
6991       *no_add_attrs = true;
6992     }
6993
6994   return NULL_TREE;
6995 }
6996
6997 /* Handle a "alloc_size" attribute; arguments as in
6998    struct attribute_spec.handler.  */
6999
7000 static tree
7001 handle_alloc_size_attribute (tree *node, tree ARG_UNUSED (name), tree args,
7002                              int ARG_UNUSED (flags), bool *no_add_attrs)
7003 {
7004   unsigned arg_count = type_num_arguments (*node);
7005   for (; args; args = TREE_CHAIN (args))
7006     {
7007       tree position = TREE_VALUE (args);
7008
7009       if (TREE_CODE (position) != INTEGER_CST
7010           || TREE_INT_CST_HIGH (position)
7011           || TREE_INT_CST_LOW (position) < 1
7012           || TREE_INT_CST_LOW (position) > arg_count )
7013         {
7014           warning (OPT_Wattributes,
7015                    "alloc_size parameter outside range");
7016           *no_add_attrs = true;
7017           return NULL_TREE;
7018         }
7019     }
7020   return NULL_TREE;
7021 }
7022
7023 /* Handle a "returns_twice" attribute; arguments as in
7024    struct attribute_spec.handler.  */
7025
7026 static tree
7027 handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7028                          int ARG_UNUSED (flags), bool *no_add_attrs)
7029 {
7030   if (TREE_CODE (*node) == FUNCTION_DECL)
7031     DECL_IS_RETURNS_TWICE (*node) = 1;
7032   else
7033     {
7034       warning (OPT_Wattributes, "%qE attribute ignored", name);
7035       *no_add_attrs = true;
7036     }
7037
7038   return NULL_TREE;
7039 }
7040
7041 /* Handle a "no_limit_stack" attribute; arguments as in
7042    struct attribute_spec.handler.  */
7043
7044 static tree
7045 handle_no_limit_stack_attribute (tree *node, tree name,
7046                                  tree ARG_UNUSED (args),
7047                                  int ARG_UNUSED (flags),
7048                                  bool *no_add_attrs)
7049 {
7050   tree decl = *node;
7051
7052   if (TREE_CODE (decl) != FUNCTION_DECL)
7053     {
7054       error ("%J%qE attribute applies only to functions", decl, name);
7055       *no_add_attrs = true;
7056     }
7057   else if (DECL_INITIAL (decl))
7058     {
7059       error ("%Jcan%'t set %qE attribute after definition", decl, name);
7060       *no_add_attrs = true;
7061     }
7062   else
7063     DECL_NO_LIMIT_STACK (decl) = 1;
7064
7065   return NULL_TREE;
7066 }
7067
7068 /* Handle a "pure" attribute; arguments as in
7069    struct attribute_spec.handler.  */
7070
7071 static tree
7072 handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7073                        int ARG_UNUSED (flags), bool *no_add_attrs)
7074 {
7075   if (TREE_CODE (*node) == FUNCTION_DECL)
7076     DECL_PURE_P (*node) = 1;
7077   /* ??? TODO: Support types.  */
7078   else
7079     {
7080       warning (OPT_Wattributes, "%qE attribute ignored", name);
7081       *no_add_attrs = true;
7082     }
7083
7084   return NULL_TREE;
7085 }
7086
7087 /* Handle a "no vops" attribute; arguments as in
7088    struct attribute_spec.handler.  */
7089
7090 static tree
7091 handle_novops_attribute (tree *node, tree ARG_UNUSED (name),
7092                          tree ARG_UNUSED (args), int ARG_UNUSED (flags),
7093                          bool *ARG_UNUSED (no_add_attrs))
7094 {
7095   gcc_assert (TREE_CODE (*node) == FUNCTION_DECL);
7096   DECL_IS_NOVOPS (*node) = 1;
7097   return NULL_TREE;
7098 }
7099
7100 /* Handle a "deprecated" attribute; arguments as in
7101    struct attribute_spec.handler.  */
7102
7103 static tree
7104 handle_deprecated_attribute (tree *node, tree name,
7105                              tree args, int flags,
7106                              bool *no_add_attrs)
7107 {
7108   tree type = NULL_TREE;
7109   int warn = 0;
7110   tree what = NULL_TREE;
7111
7112   if (!args)
7113     *no_add_attrs = true;
7114   else if (TREE_CODE (TREE_VALUE (args)) != STRING_CST)
7115     {
7116       error ("deprecated message is not a string");
7117       *no_add_attrs = true;
7118     }
7119
7120   if (DECL_P (*node))
7121     {
7122       tree decl = *node;
7123       type = TREE_TYPE (decl);
7124
7125       if (TREE_CODE (decl) == TYPE_DECL
7126           || TREE_CODE (decl) == PARM_DECL
7127           || TREE_CODE (decl) == VAR_DECL
7128           || TREE_CODE (decl) == FUNCTION_DECL
7129           || TREE_CODE (decl) == FIELD_DECL)
7130         TREE_DEPRECATED (decl) = 1;
7131       else
7132         warn = 1;
7133     }
7134   else if (TYPE_P (*node))
7135     {
7136       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
7137         *node = build_variant_type_copy (*node);
7138       TREE_DEPRECATED (*node) = 1;
7139       type = *node;
7140     }
7141   else
7142     warn = 1;
7143
7144   if (warn)
7145     {
7146       *no_add_attrs = true;
7147       if (type && TYPE_NAME (type))
7148         {
7149           if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
7150             what = TYPE_NAME (*node);
7151           else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
7152                    && DECL_NAME (TYPE_NAME (type)))
7153             what = DECL_NAME (TYPE_NAME (type));
7154         }
7155       if (what)
7156         warning (OPT_Wattributes, "%qE attribute ignored for %qE", name, what);
7157       else
7158         warning (OPT_Wattributes, "%qE attribute ignored", name);
7159     }
7160
7161   return NULL_TREE;
7162 }
7163
7164 /* Handle a "vector_size" attribute; arguments as in
7165    struct attribute_spec.handler.  */
7166
7167 static tree
7168 handle_vector_size_attribute (tree *node, tree name, tree args,
7169                               int ARG_UNUSED (flags),
7170                               bool *no_add_attrs)
7171 {
7172   unsigned HOST_WIDE_INT vecsize, nunits;
7173   enum machine_mode orig_mode;
7174   tree type = *node, new_type, size;
7175
7176   *no_add_attrs = true;
7177
7178   size = TREE_VALUE (args);
7179
7180   if (!host_integerp (size, 1))
7181     {
7182       warning (OPT_Wattributes, "%qE attribute ignored", name);
7183       return NULL_TREE;
7184     }
7185
7186   /* Get the vector size (in bytes).  */
7187   vecsize = tree_low_cst (size, 1);
7188
7189   /* We need to provide for vector pointers, vector arrays, and
7190      functions returning vectors.  For example:
7191
7192        __attribute__((vector_size(16))) short *foo;
7193
7194      In this case, the mode is SI, but the type being modified is
7195      HI, so we need to look further.  */
7196
7197   while (POINTER_TYPE_P (type)
7198          || TREE_CODE (type) == FUNCTION_TYPE
7199          || TREE_CODE (type) == METHOD_TYPE
7200          || TREE_CODE (type) == ARRAY_TYPE
7201          || TREE_CODE (type) == OFFSET_TYPE)
7202     type = TREE_TYPE (type);
7203
7204   /* Get the mode of the type being modified.  */
7205   orig_mode = TYPE_MODE (type);
7206
7207   if ((!INTEGRAL_TYPE_P (type)
7208        && !SCALAR_FLOAT_TYPE_P (type)
7209        && !FIXED_POINT_TYPE_P (type))
7210       || (!SCALAR_FLOAT_MODE_P (orig_mode)
7211           && GET_MODE_CLASS (orig_mode) != MODE_INT
7212           && !ALL_SCALAR_FIXED_POINT_MODE_P (orig_mode))
7213       || !host_integerp (TYPE_SIZE_UNIT (type), 1)
7214       || TREE_CODE (type) == BOOLEAN_TYPE)
7215     {
7216       error ("invalid vector type for attribute %qE", name);
7217       return NULL_TREE;
7218     }
7219
7220   if (vecsize % tree_low_cst (TYPE_SIZE_UNIT (type), 1))
7221     {
7222       error ("vector size not an integral multiple of component size");
7223       return NULL;
7224     }
7225
7226   if (vecsize == 0)
7227     {
7228       error ("zero vector size");
7229       return NULL;
7230     }
7231
7232   /* Calculate how many units fit in the vector.  */
7233   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
7234   if (nunits & (nunits - 1))
7235     {
7236       error ("number of components of the vector not a power of two");
7237       return NULL_TREE;
7238     }
7239
7240   new_type = build_vector_type (type, nunits);
7241
7242   /* Build back pointers if needed.  */
7243   *node = lang_hooks.types.reconstruct_complex_type (*node, new_type);
7244
7245   return NULL_TREE;
7246 }
7247
7248 /* Handle the "nonnull" attribute.  */
7249 static tree
7250 handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
7251                           tree args, int ARG_UNUSED (flags),
7252                           bool *no_add_attrs)
7253 {
7254   tree type = *node;
7255   unsigned HOST_WIDE_INT attr_arg_num;
7256
7257   /* If no arguments are specified, all pointer arguments should be
7258      non-null.  Verify a full prototype is given so that the arguments
7259      will have the correct types when we actually check them later.  */
7260   if (!args)
7261     {
7262       if (!TYPE_ARG_TYPES (type))
7263         {
7264           error ("nonnull attribute without arguments on a non-prototype");
7265           *no_add_attrs = true;
7266         }
7267       return NULL_TREE;
7268     }
7269
7270   /* Argument list specified.  Verify that each argument number references
7271      a pointer argument.  */
7272   for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
7273     {
7274       tree argument;
7275       unsigned HOST_WIDE_INT arg_num = 0, ck_num;
7276
7277       if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
7278         {
7279           error ("nonnull argument has invalid operand number (argument %lu)",
7280                  (unsigned long) attr_arg_num);
7281           *no_add_attrs = true;
7282           return NULL_TREE;
7283         }
7284
7285       argument = TYPE_ARG_TYPES (type);
7286       if (argument)
7287         {
7288           for (ck_num = 1; ; ck_num++)
7289             {
7290               if (!argument || ck_num == arg_num)
7291                 break;
7292               argument = TREE_CHAIN (argument);
7293             }
7294
7295           if (!argument
7296               || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
7297             {
7298               error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)",
7299                      (unsigned long) attr_arg_num, (unsigned long) arg_num);
7300               *no_add_attrs = true;
7301               return NULL_TREE;
7302             }
7303
7304           if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
7305             {
7306               error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)",
7307                    (unsigned long) attr_arg_num, (unsigned long) arg_num);
7308               *no_add_attrs = true;
7309               return NULL_TREE;
7310             }
7311         }
7312     }
7313
7314   return NULL_TREE;
7315 }
7316
7317 /* Check the argument list of a function call for null in argument slots
7318    that are marked as requiring a non-null pointer argument.  The NARGS
7319    arguments are passed in the array ARGARRAY.
7320 */
7321
7322 static void
7323 check_function_nonnull (tree attrs, int nargs, tree *argarray)
7324 {
7325   tree a, args;
7326   int i;
7327
7328   for (a = attrs; a; a = TREE_CHAIN (a))
7329     {
7330       if (is_attribute_p ("nonnull", TREE_PURPOSE (a)))
7331         {
7332           args = TREE_VALUE (a);
7333
7334           /* Walk the argument list.  If we encounter an argument number we
7335              should check for non-null, do it.  If the attribute has no args,
7336              then every pointer argument is checked (in which case the check
7337              for pointer type is done in check_nonnull_arg).  */
7338           for (i = 0; i < nargs; i++)
7339             {
7340               if (!args || nonnull_check_p (args, i + 1))
7341                 check_function_arguments_recurse (check_nonnull_arg, NULL,
7342                                                   argarray[i],
7343                                                   i + 1);
7344             }
7345         }
7346     }
7347 }
7348
7349 /* Check that the Nth argument of a function call (counting backwards
7350    from the end) is a (pointer)0.  The NARGS arguments are passed in the
7351    array ARGARRAY.  */
7352
7353 static void
7354 check_function_sentinel (tree attrs, int nargs, tree *argarray, tree typelist)
7355 {
7356   tree attr = lookup_attribute ("sentinel", attrs);
7357
7358   if (attr)
7359     {
7360       int len = 0;
7361       int pos = 0;
7362       tree sentinel;
7363
7364       /* Skip over the named arguments.  */
7365       while (typelist && len < nargs)
7366         {
7367           typelist = TREE_CHAIN (typelist);
7368           len++;
7369         }
7370
7371       if (TREE_VALUE (attr))
7372         {
7373           tree p = TREE_VALUE (TREE_VALUE (attr));
7374           pos = TREE_INT_CST_LOW (p);
7375         }
7376
7377       /* The sentinel must be one of the varargs, i.e.
7378          in position >= the number of fixed arguments.  */
7379       if ((nargs - 1 - pos) < len)
7380         {
7381           warning (OPT_Wformat,
7382                    "not enough variable arguments to fit a sentinel");
7383           return;
7384         }
7385
7386       /* Validate the sentinel.  */
7387       sentinel = argarray[nargs - 1 - pos];
7388       if ((!POINTER_TYPE_P (TREE_TYPE (sentinel))
7389            || !integer_zerop (sentinel))
7390           /* Although __null (in C++) is only an integer we allow it
7391              nevertheless, as we are guaranteed that it's exactly
7392              as wide as a pointer, and we don't want to force
7393              users to cast the NULL they have written there.
7394              We warn with -Wstrict-null-sentinel, though.  */
7395           && (warn_strict_null_sentinel || null_node != sentinel))
7396         warning (OPT_Wformat, "missing sentinel in function call");
7397     }
7398 }
7399
7400 /* Helper for check_function_nonnull; given a list of operands which
7401    must be non-null in ARGS, determine if operand PARAM_NUM should be
7402    checked.  */
7403
7404 static bool
7405 nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num)
7406 {
7407   unsigned HOST_WIDE_INT arg_num = 0;
7408
7409   for (; args; args = TREE_CHAIN (args))
7410     {
7411       bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num);
7412
7413       gcc_assert (found);
7414
7415       if (arg_num == param_num)
7416         return true;
7417     }
7418   return false;
7419 }
7420
7421 /* Check that the function argument PARAM (which is operand number
7422    PARAM_NUM) is non-null.  This is called by check_function_nonnull
7423    via check_function_arguments_recurse.  */
7424
7425 static void
7426 check_nonnull_arg (void * ARG_UNUSED (ctx), tree param,
7427                    unsigned HOST_WIDE_INT param_num)
7428 {
7429   /* Just skip checking the argument if it's not a pointer.  This can
7430      happen if the "nonnull" attribute was given without an operand
7431      list (which means to check every pointer argument).  */
7432
7433   if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE)
7434     return;
7435
7436   if (integer_zerop (param))
7437     warning (OPT_Wnonnull, "null argument where non-null required "
7438              "(argument %lu)", (unsigned long) param_num);
7439 }
7440
7441 /* Helper for nonnull attribute handling; fetch the operand number
7442    from the attribute argument list.  */
7443
7444 static bool
7445 get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp)
7446 {
7447   /* Verify the arg number is a constant.  */
7448   if (TREE_CODE (arg_num_expr) != INTEGER_CST
7449       || TREE_INT_CST_HIGH (arg_num_expr) != 0)
7450     return false;
7451
7452   *valp = TREE_INT_CST_LOW (arg_num_expr);
7453   return true;
7454 }
7455
7456 /* Handle a "nothrow" attribute; arguments as in
7457    struct attribute_spec.handler.  */
7458
7459 static tree
7460 handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7461                           int ARG_UNUSED (flags), bool *no_add_attrs)
7462 {
7463   if (TREE_CODE (*node) == FUNCTION_DECL)
7464     TREE_NOTHROW (*node) = 1;
7465   /* ??? TODO: Support types.  */
7466   else
7467     {
7468       warning (OPT_Wattributes, "%qE attribute ignored", name);
7469       *no_add_attrs = true;
7470     }
7471
7472   return NULL_TREE;
7473 }
7474
7475 /* Handle a "cleanup" attribute; arguments as in
7476    struct attribute_spec.handler.  */
7477
7478 static tree
7479 handle_cleanup_attribute (tree *node, tree name, tree args,
7480                           int ARG_UNUSED (flags), bool *no_add_attrs)
7481 {
7482   tree decl = *node;
7483   tree cleanup_id, cleanup_decl;
7484
7485   /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do
7486      for global destructors in C++.  This requires infrastructure that
7487      we don't have generically at the moment.  It's also not a feature
7488      we'd be missing too much, since we do have attribute constructor.  */
7489   if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl))
7490     {
7491       warning (OPT_Wattributes, "%qE attribute ignored", name);
7492       *no_add_attrs = true;
7493       return NULL_TREE;
7494     }
7495
7496   /* Verify that the argument is a function in scope.  */
7497   /* ??? We could support pointers to functions here as well, if
7498      that was considered desirable.  */
7499   cleanup_id = TREE_VALUE (args);
7500   if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE)
7501     {
7502       error ("cleanup argument not an identifier");
7503       *no_add_attrs = true;
7504       return NULL_TREE;
7505     }
7506   cleanup_decl = lookup_name (cleanup_id);
7507   if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL)
7508     {
7509       error ("cleanup argument not a function");
7510       *no_add_attrs = true;
7511       return NULL_TREE;
7512     }
7513
7514   /* That the function has proper type is checked with the
7515      eventual call to build_function_call.  */
7516
7517   return NULL_TREE;
7518 }
7519
7520 /* Handle a "warn_unused_result" attribute.  No special handling.  */
7521
7522 static tree
7523 handle_warn_unused_result_attribute (tree *node, tree name,
7524                                tree ARG_UNUSED (args),
7525                                int ARG_UNUSED (flags), bool *no_add_attrs)
7526 {
7527   /* Ignore the attribute for functions not returning any value.  */
7528   if (VOID_TYPE_P (TREE_TYPE (*node)))
7529     {
7530       warning (OPT_Wattributes, "%qE attribute ignored", name);
7531       *no_add_attrs = true;
7532     }
7533
7534   return NULL_TREE;
7535 }
7536
7537 /* Handle a "sentinel" attribute.  */
7538
7539 static tree
7540 handle_sentinel_attribute (tree *node, tree name, tree args,
7541                            int ARG_UNUSED (flags), bool *no_add_attrs)
7542 {
7543   tree params = TYPE_ARG_TYPES (*node);
7544
7545   if (!params)
7546     {
7547       warning (OPT_Wattributes,
7548                "%qE attribute requires prototypes with named arguments", name);
7549       *no_add_attrs = true;
7550     }
7551   else
7552     {
7553       while (TREE_CHAIN (params))
7554         params = TREE_CHAIN (params);
7555
7556       if (VOID_TYPE_P (TREE_VALUE (params)))
7557         {
7558           warning (OPT_Wattributes,
7559                    "%qE attribute only applies to variadic functions", name);
7560           *no_add_attrs = true;
7561         }
7562     }
7563
7564   if (args)
7565     {
7566       tree position = TREE_VALUE (args);
7567
7568       if (TREE_CODE (position) != INTEGER_CST)
7569         {
7570           warning (OPT_Wattributes,
7571                    "requested position is not an integer constant");
7572           *no_add_attrs = true;
7573         }
7574       else
7575         {
7576           if (tree_int_cst_lt (position, integer_zero_node))
7577             {
7578               warning (OPT_Wattributes,
7579                        "requested position is less than zero");
7580               *no_add_attrs = true;
7581             }
7582         }
7583     }
7584
7585   return NULL_TREE;
7586 }
7587
7588 /* Handle a "type_generic" attribute.  */
7589
7590 static tree
7591 handle_type_generic_attribute (tree *node, tree ARG_UNUSED (name),
7592                                tree ARG_UNUSED (args), int ARG_UNUSED (flags),
7593                                bool * ARG_UNUSED (no_add_attrs))
7594 {
7595   tree params;
7596
7597   /* Ensure we have a function type.  */
7598   gcc_assert (TREE_CODE (*node) == FUNCTION_TYPE);
7599
7600   params = TYPE_ARG_TYPES (*node);
7601   while (params && ! VOID_TYPE_P (TREE_VALUE (params)))
7602     params = TREE_CHAIN (params);
7603
7604   /* Ensure we have a variadic function.  */
7605   gcc_assert (!params);
7606
7607   return NULL_TREE;
7608 }
7609
7610 /* Handle a "target" attribute.  */
7611
7612 static tree
7613 handle_target_attribute (tree *node, tree name, tree args, int flags,
7614                          bool *no_add_attrs)
7615 {
7616   /* Ensure we have a function type.  */
7617   if (TREE_CODE (*node) != FUNCTION_DECL)
7618     {
7619       warning (OPT_Wattributes, "%qE attribute ignored", name);
7620       *no_add_attrs = true;
7621     }
7622   else if (! targetm.target_option.valid_attribute_p (*node, name, args,
7623                                                       flags))
7624     *no_add_attrs = true;
7625
7626   return NULL_TREE;
7627 }
7628
7629 /* Arguments being collected for optimization.  */
7630 typedef const char *const_char_p;               /* For DEF_VEC_P.  */
7631 DEF_VEC_P(const_char_p);
7632 DEF_VEC_ALLOC_P(const_char_p, gc);
7633 static GTY(()) VEC(const_char_p, gc) *optimize_args;
7634
7635
7636 /* Inner function to convert a TREE_LIST to argv string to parse the optimize
7637    options in ARGS.  ATTR_P is true if this is for attribute(optimize), and
7638    false for #pragma GCC optimize.  */
7639
7640 bool
7641 parse_optimize_options (tree args, bool attr_p)
7642 {
7643   bool ret = true;
7644   unsigned opt_argc;
7645   unsigned i;
7646   int saved_flag_strict_aliasing;
7647   const char **opt_argv;
7648   tree ap;
7649
7650   /* Build up argv vector.  Just in case the string is stored away, use garbage
7651      collected strings.  */
7652   VEC_truncate (const_char_p, optimize_args, 0);
7653   VEC_safe_push (const_char_p, gc, optimize_args, NULL);
7654
7655   for (ap = args; ap != NULL_TREE; ap = TREE_CHAIN (ap))
7656     {
7657       tree value = TREE_VALUE (ap);
7658
7659       if (TREE_CODE (value) == INTEGER_CST)
7660         {
7661           char buffer[20];
7662           sprintf (buffer, "-O%ld", (long) TREE_INT_CST_LOW (value));
7663           VEC_safe_push (const_char_p, gc, optimize_args, ggc_strdup (buffer));
7664         }
7665
7666       else if (TREE_CODE (value) == STRING_CST)
7667         {
7668           /* Split string into multiple substrings.  */
7669           size_t len = TREE_STRING_LENGTH (value);
7670           char *p = ASTRDUP (TREE_STRING_POINTER (value));
7671           char *end = p + len;
7672           char *comma;
7673           char *next_p = p;
7674
7675           while (next_p != NULL)
7676             {
7677               size_t len2;
7678               char *q, *r;
7679
7680               p = next_p;
7681               comma = strchr (p, ',');
7682               if (comma)
7683                 {
7684                   len2 = comma - p;
7685                   *comma = '\0';
7686                   next_p = comma+1;
7687                 }
7688               else
7689                 {
7690                   len2 = end - p;
7691                   next_p = NULL;
7692                 }
7693
7694               r = q = (char *) ggc_alloc (len2 + 3);
7695
7696               /* If the user supplied -Oxxx or -fxxx, only allow -Oxxx or -fxxx
7697                  options.  */
7698               if (*p == '-' && p[1] != 'O' && p[1] != 'f')
7699                 {
7700                   ret = false;
7701                   if (attr_p)
7702                     warning (OPT_Wattributes,
7703                              "Bad option %s to optimize attribute.", p);
7704                   else
7705                     warning (OPT_Wpragmas,
7706                              "Bad option %s to pragma attribute", p);
7707                   continue;
7708                 }
7709
7710               if (*p != '-')
7711                 {
7712                   *r++ = '-';
7713
7714                   /* Assume that Ox is -Ox, a numeric value is -Ox, a s by
7715                      itself is -Os, and any other switch begins with a -f.  */
7716                   if ((*p >= '0' && *p <= '9')
7717                       || (p[0] == 's' && p[1] == '\0'))
7718                     *r++ = 'O';
7719                   else if (*p != 'O')
7720                     *r++ = 'f';
7721                 }
7722
7723               memcpy (r, p, len2);
7724               r[len2] = '\0';
7725               VEC_safe_push (const_char_p, gc, optimize_args, q);
7726             }
7727
7728         }
7729     }
7730
7731   opt_argc = VEC_length (const_char_p, optimize_args);
7732   opt_argv = (const char **) alloca (sizeof (char *) * (opt_argc + 1));
7733
7734   for (i = 1; i < opt_argc; i++)
7735     opt_argv[i] = VEC_index (const_char_p, optimize_args, i);
7736
7737   saved_flag_strict_aliasing = flag_strict_aliasing;
7738
7739   /* Now parse the options.  */
7740   decode_options (opt_argc, opt_argv);
7741
7742   /* Don't allow changing -fstrict-aliasing.  */
7743   flag_strict_aliasing = saved_flag_strict_aliasing;
7744
7745   VEC_truncate (const_char_p, optimize_args, 0);
7746   return ret;
7747 }
7748
7749 /* For handling "optimize" attribute. arguments as in
7750    struct attribute_spec.handler.  */
7751
7752 static tree
7753 handle_optimize_attribute (tree *node, tree name, tree args,
7754                            int ARG_UNUSED (flags), bool *no_add_attrs)
7755 {
7756   /* Ensure we have a function type.  */
7757   if (TREE_CODE (*node) != FUNCTION_DECL)
7758     {
7759       warning (OPT_Wattributes, "%qE attribute ignored", name);
7760       *no_add_attrs = true;
7761     }
7762   else
7763     {
7764       struct cl_optimization cur_opts;
7765       tree old_opts = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node);
7766
7767       /* Save current options.  */
7768       cl_optimization_save (&cur_opts);
7769
7770       /* If we previously had some optimization options, use them as the
7771          default.  */
7772       if (old_opts)
7773         cl_optimization_restore (TREE_OPTIMIZATION (old_opts));
7774
7775       /* Parse options, and update the vector.  */
7776       parse_optimize_options (args, true);
7777       DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node)
7778         = build_optimization_node ();
7779
7780       /* Restore current options.  */
7781       cl_optimization_restore (&cur_opts);
7782     }
7783
7784   return NULL_TREE;
7785 }
7786 \f
7787 /* Check for valid arguments being passed to a function.
7788    ATTRS is a list of attributes.  There are NARGS arguments in the array
7789    ARGARRAY.  TYPELIST is the list of argument types for the function.
7790  */
7791 void
7792 check_function_arguments (tree attrs, int nargs, tree *argarray, tree typelist)
7793 {
7794   /* Check for null being passed in a pointer argument that must be
7795      non-null.  We also need to do this if format checking is enabled.  */
7796
7797   if (warn_nonnull)
7798     check_function_nonnull (attrs, nargs, argarray);
7799
7800   /* Check for errors in format strings.  */
7801
7802   if (warn_format || warn_missing_format_attribute)
7803     check_function_format (attrs, nargs, argarray);
7804
7805   if (warn_format)
7806     check_function_sentinel (attrs, nargs, argarray, typelist);
7807 }
7808
7809 /* Generic argument checking recursion routine.  PARAM is the argument to
7810    be checked.  PARAM_NUM is the number of the argument.  CALLBACK is invoked
7811    once the argument is resolved.  CTX is context for the callback.  */
7812 void
7813 check_function_arguments_recurse (void (*callback)
7814                                   (void *, tree, unsigned HOST_WIDE_INT),
7815                                   void *ctx, tree param,
7816                                   unsigned HOST_WIDE_INT param_num)
7817 {
7818   if (CONVERT_EXPR_P (param)
7819       && (TYPE_PRECISION (TREE_TYPE (param))
7820           == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (param, 0)))))
7821     {
7822       /* Strip coercion.  */
7823       check_function_arguments_recurse (callback, ctx,
7824                                         TREE_OPERAND (param, 0), param_num);
7825       return;
7826     }
7827
7828   if (TREE_CODE (param) == CALL_EXPR)
7829     {
7830       tree type = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (param)));
7831       tree attrs;
7832       bool found_format_arg = false;
7833
7834       /* See if this is a call to a known internationalization function
7835          that modifies a format arg.  Such a function may have multiple
7836          format_arg attributes (for example, ngettext).  */
7837
7838       for (attrs = TYPE_ATTRIBUTES (type);
7839            attrs;
7840            attrs = TREE_CHAIN (attrs))
7841         if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs)))
7842           {
7843             tree inner_arg;
7844             tree format_num_expr;
7845             int format_num;
7846             int i;
7847             call_expr_arg_iterator iter;
7848
7849             /* Extract the argument number, which was previously checked
7850                to be valid.  */
7851             format_num_expr = TREE_VALUE (TREE_VALUE (attrs));
7852
7853             gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST
7854                         && !TREE_INT_CST_HIGH (format_num_expr));
7855
7856             format_num = TREE_INT_CST_LOW (format_num_expr);
7857
7858             for (inner_arg = first_call_expr_arg (param, &iter), i = 1;
7859                  inner_arg != 0;
7860                  inner_arg = next_call_expr_arg (&iter), i++)
7861               if (i == format_num)
7862                 {
7863                   check_function_arguments_recurse (callback, ctx,
7864                                                     inner_arg, param_num);
7865                   found_format_arg = true;
7866                   break;
7867                 }
7868           }
7869
7870       /* If we found a format_arg attribute and did a recursive check,
7871          we are done with checking this argument.  Otherwise, we continue
7872          and this will be considered a non-literal.  */
7873       if (found_format_arg)
7874         return;
7875     }
7876
7877   if (TREE_CODE (param) == COND_EXPR)
7878     {
7879       /* Check both halves of the conditional expression.  */
7880       check_function_arguments_recurse (callback, ctx,
7881                                         TREE_OPERAND (param, 1), param_num);
7882       check_function_arguments_recurse (callback, ctx,
7883                                         TREE_OPERAND (param, 2), param_num);
7884       return;
7885     }
7886
7887   (*callback) (ctx, param, param_num);
7888 }
7889
7890 /* Checks the number of arguments NARGS against the required number
7891    REQUIRED and issues an error if there is a mismatch.  Returns true
7892    if the number of arguments is correct, otherwise false.  */
7893
7894 static bool
7895 validate_nargs (tree fndecl, int nargs, int required)
7896 {
7897   if (nargs < required)
7898     {
7899       error ("not enough arguments to function %qE", fndecl);
7900       return false;
7901     }
7902   else if (nargs > required)
7903     {
7904       error ("too many arguments to function %qE", fndecl);
7905       return false;
7906     }
7907   return true;
7908 }
7909
7910 /* Verifies the NARGS arguments ARGS to the builtin function FNDECL.
7911    Returns false if there was an error, otherwise true.  */
7912
7913 bool
7914 check_builtin_function_arguments (tree fndecl, int nargs, tree *args)
7915 {
7916   if (!DECL_BUILT_IN (fndecl)
7917       || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL)
7918     return true;
7919
7920   switch (DECL_FUNCTION_CODE (fndecl))
7921     {
7922     case BUILT_IN_CONSTANT_P:
7923       return validate_nargs (fndecl, nargs, 1);
7924
7925     case BUILT_IN_ISFINITE:
7926     case BUILT_IN_ISINF:
7927     case BUILT_IN_ISINF_SIGN:
7928     case BUILT_IN_ISNAN:
7929     case BUILT_IN_ISNORMAL:
7930       if (validate_nargs (fndecl, nargs, 1))
7931         {
7932           if (TREE_CODE (TREE_TYPE (args[0])) != REAL_TYPE)
7933             {
7934               error ("non-floating-point argument in call to "
7935                      "function %qE", fndecl);
7936               return false;
7937             }
7938           return true;
7939         }
7940       return false;
7941
7942     case BUILT_IN_ISGREATER:
7943     case BUILT_IN_ISGREATEREQUAL:
7944     case BUILT_IN_ISLESS:
7945     case BUILT_IN_ISLESSEQUAL:
7946     case BUILT_IN_ISLESSGREATER:
7947     case BUILT_IN_ISUNORDERED:
7948       if (validate_nargs (fndecl, nargs, 2))
7949         {
7950           enum tree_code code0, code1;
7951           code0 = TREE_CODE (TREE_TYPE (args[0]));
7952           code1 = TREE_CODE (TREE_TYPE (args[1]));
7953           if (!((code0 == REAL_TYPE && code1 == REAL_TYPE)
7954                 || (code0 == REAL_TYPE && code1 == INTEGER_TYPE)
7955                 || (code0 == INTEGER_TYPE && code1 == REAL_TYPE)))
7956             {
7957               error ("non-floating-point arguments in call to "
7958                      "function %qE", fndecl);
7959               return false;
7960             }
7961           return true;
7962         }
7963       return false;
7964
7965     case BUILT_IN_FPCLASSIFY:
7966       if (validate_nargs (fndecl, nargs, 6))
7967         {
7968           unsigned i;
7969
7970           for (i=0; i<5; i++)
7971             if (TREE_CODE (args[i]) != INTEGER_CST)
7972               {
7973                 error ("non-const integer argument %u in call to function %qE",
7974                        i+1, fndecl);
7975                 return false;
7976               }
7977
7978           if (TREE_CODE (TREE_TYPE (args[5])) != REAL_TYPE)
7979             {
7980               error ("non-floating-point argument in call to function %qE",
7981                      fndecl);
7982               return false;
7983             }
7984           return true;
7985         }
7986       return false;
7987
7988     default:
7989       return true;
7990     }
7991 }
7992
7993 /* Function to help qsort sort FIELD_DECLs by name order.  */
7994
7995 int
7996 field_decl_cmp (const void *x_p, const void *y_p)
7997 {
7998   const tree *const x = (const tree *const) x_p;
7999   const tree *const y = (const tree *const) y_p;
8000
8001   if (DECL_NAME (*x) == DECL_NAME (*y))
8002     /* A nontype is "greater" than a type.  */
8003     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
8004   if (DECL_NAME (*x) == NULL_TREE)
8005     return -1;
8006   if (DECL_NAME (*y) == NULL_TREE)
8007     return 1;
8008   if (DECL_NAME (*x) < DECL_NAME (*y))
8009     return -1;
8010   return 1;
8011 }
8012
8013 static struct {
8014   gt_pointer_operator new_value;
8015   void *cookie;
8016 } resort_data;
8017
8018 /* This routine compares two fields like field_decl_cmp but using the
8019 pointer operator in resort_data.  */
8020
8021 static int
8022 resort_field_decl_cmp (const void *x_p, const void *y_p)
8023 {
8024   const tree *const x = (const tree *const) x_p;
8025   const tree *const y = (const tree *const) y_p;
8026
8027   if (DECL_NAME (*x) == DECL_NAME (*y))
8028     /* A nontype is "greater" than a type.  */
8029     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
8030   if (DECL_NAME (*x) == NULL_TREE)
8031     return -1;
8032   if (DECL_NAME (*y) == NULL_TREE)
8033     return 1;
8034   {
8035     tree d1 = DECL_NAME (*x);
8036     tree d2 = DECL_NAME (*y);
8037     resort_data.new_value (&d1, resort_data.cookie);
8038     resort_data.new_value (&d2, resort_data.cookie);
8039     if (d1 < d2)
8040       return -1;
8041   }
8042   return 1;
8043 }
8044
8045 /* Resort DECL_SORTED_FIELDS because pointers have been reordered.  */
8046
8047 void
8048 resort_sorted_fields (void *obj,
8049                       void * ARG_UNUSED (orig_obj),
8050                       gt_pointer_operator new_value,
8051                       void *cookie)
8052 {
8053   struct sorted_fields_type *sf = (struct sorted_fields_type *) obj;
8054   resort_data.new_value = new_value;
8055   resort_data.cookie = cookie;
8056   qsort (&sf->elts[0], sf->len, sizeof (tree),
8057          resort_field_decl_cmp);
8058 }
8059
8060 /* Subroutine of c_parse_error.
8061    Return the result of concatenating LHS and RHS. RHS is really
8062    a string literal, its first character is indicated by RHS_START and
8063    RHS_SIZE is its length (including the terminating NUL character).
8064
8065    The caller is responsible for deleting the returned pointer.  */
8066
8067 static char *
8068 catenate_strings (const char *lhs, const char *rhs_start, int rhs_size)
8069 {
8070   const int lhs_size = strlen (lhs);
8071   char *result = XNEWVEC (char, lhs_size + rhs_size);
8072   strncpy (result, lhs, lhs_size);
8073   strncpy (result + lhs_size, rhs_start, rhs_size);
8074   return result;
8075 }
8076
8077 /* Issue the error given by GMSGID, indicating that it occurred before
8078    TOKEN, which had the associated VALUE.  */
8079
8080 void
8081 c_parse_error (const char *gmsgid, enum cpp_ttype token_type,
8082                tree value, unsigned char token_flags)
8083 {
8084 #define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2))
8085
8086   char *message = NULL;
8087
8088   if (token_type == CPP_EOF)
8089     message = catenate_messages (gmsgid, " at end of input");
8090   else if (token_type == CPP_CHAR
8091            || token_type == CPP_WCHAR
8092            || token_type == CPP_CHAR16
8093            || token_type == CPP_CHAR32)
8094     {
8095       unsigned int val = TREE_INT_CST_LOW (value);
8096       const char *prefix;
8097
8098       switch (token_type)
8099         {
8100         default:
8101           prefix = "";
8102           break;
8103         case CPP_WCHAR:
8104           prefix = "L";
8105           break;
8106         case CPP_CHAR16:
8107           prefix = "u";
8108           break;
8109         case CPP_CHAR32:
8110           prefix = "U";
8111           break;
8112         }
8113
8114       if (val <= UCHAR_MAX && ISGRAPH (val))
8115         message = catenate_messages (gmsgid, " before %s'%c'");
8116       else
8117         message = catenate_messages (gmsgid, " before %s'\\x%x'");
8118
8119       error (message, prefix, val);
8120       free (message);
8121       message = NULL;
8122     }
8123   else if (token_type == CPP_STRING
8124            || token_type == CPP_WSTRING
8125            || token_type == CPP_STRING16
8126            || token_type == CPP_STRING32)
8127     message = catenate_messages (gmsgid, " before string constant");
8128   else if (token_type == CPP_NUMBER)
8129     message = catenate_messages (gmsgid, " before numeric constant");
8130   else if (token_type == CPP_NAME)
8131     {
8132       message = catenate_messages (gmsgid, " before %qE");
8133       error (message, value);
8134       free (message);
8135       message = NULL;
8136     }
8137   else if (token_type == CPP_PRAGMA)
8138     message = catenate_messages (gmsgid, " before %<#pragma%>");
8139   else if (token_type == CPP_PRAGMA_EOL)
8140     message = catenate_messages (gmsgid, " before end of line");
8141   else if (token_type < N_TTYPES)
8142     {
8143       message = catenate_messages (gmsgid, " before %qs token");
8144       error (message, cpp_type2name (token_type, token_flags));
8145       free (message);
8146       message = NULL;
8147     }
8148   else
8149     error (gmsgid);
8150
8151   if (message)
8152     {
8153       error (message);
8154       free (message);
8155     }
8156 #undef catenate_messages
8157 }
8158
8159 /* Callback from cpp_error for PFILE to print diagnostics from the
8160    preprocessor.  The diagnostic is of type LEVEL, at location
8161    LOCATION unless this is after lexing and the compiler's location
8162    should be used instead, with column number possibly overridden by
8163    COLUMN_OVERRIDE if not zero; MSG is the translated message and AP
8164    the arguments.  Returns true if a diagnostic was emitted, false
8165    otherwise.  */
8166
8167 bool
8168 c_cpp_error (cpp_reader *pfile ATTRIBUTE_UNUSED, int level,
8169              location_t location, unsigned int column_override,
8170              const char *msg, va_list *ap)
8171 {
8172   diagnostic_info diagnostic;
8173   diagnostic_t dlevel;
8174   int save_warn_system_headers = warn_system_headers;
8175   bool ret;
8176
8177   switch (level)
8178     {
8179     case CPP_DL_WARNING_SYSHDR:
8180       if (flag_no_output)
8181         return false;
8182       warn_system_headers = 1;
8183       /* Fall through.  */
8184     case CPP_DL_WARNING:
8185       if (flag_no_output)
8186         return false;
8187       dlevel = DK_WARNING;
8188       break;
8189     case CPP_DL_PEDWARN:
8190       if (flag_no_output && !flag_pedantic_errors)
8191         return false;
8192       dlevel = DK_PEDWARN;
8193       break;
8194     case CPP_DL_ERROR:
8195       dlevel = DK_ERROR;
8196       break;
8197     case CPP_DL_ICE:
8198       dlevel = DK_ICE;
8199       break;
8200     case CPP_DL_NOTE:
8201       dlevel = DK_NOTE;
8202       break;
8203     case CPP_DL_FATAL:
8204       dlevel = DK_FATAL;
8205       break;
8206     default:
8207       gcc_unreachable ();
8208     }
8209   if (done_lexing)
8210     location = input_location;
8211   diagnostic_set_info_translated (&diagnostic, msg, ap,
8212                                   location, dlevel);
8213   if (column_override)
8214     diagnostic_override_column (&diagnostic, column_override);
8215   ret = report_diagnostic (&diagnostic);
8216   if (level == CPP_DL_WARNING_SYSHDR)
8217     warn_system_headers = save_warn_system_headers;
8218   return ret;
8219 }
8220
8221 /* Walk a gimplified function and warn for functions whose return value is
8222    ignored and attribute((warn_unused_result)) is set.  This is done before
8223    inlining, so we don't have to worry about that.  */
8224
8225 void
8226 c_warn_unused_result (gimple_seq seq)
8227 {
8228   tree fdecl, ftype;
8229   gimple_stmt_iterator i;
8230
8231   for (i = gsi_start (seq); !gsi_end_p (i); gsi_next (&i))
8232     {
8233       gimple g = gsi_stmt (i);
8234
8235       switch (gimple_code (g))
8236         {
8237         case GIMPLE_BIND:
8238           c_warn_unused_result (gimple_bind_body (g));
8239           break;
8240         case GIMPLE_TRY:
8241           c_warn_unused_result (gimple_try_eval (g));
8242           c_warn_unused_result (gimple_try_cleanup (g));
8243           break;
8244         case GIMPLE_CATCH:
8245           c_warn_unused_result (gimple_catch_handler (g));
8246           break;
8247         case GIMPLE_EH_FILTER:
8248           c_warn_unused_result (gimple_eh_filter_failure (g));
8249           break;
8250
8251         case GIMPLE_CALL:
8252           if (gimple_call_lhs (g))
8253             break;
8254
8255           /* This is a naked call, as opposed to a GIMPLE_CALL with an
8256              LHS.  All calls whose value is ignored should be
8257              represented like this.  Look for the attribute.  */
8258           fdecl = gimple_call_fndecl (g);
8259           ftype = TREE_TYPE (TREE_TYPE (gimple_call_fn (g)));
8260
8261           if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype)))
8262             {
8263               location_t loc = gimple_location (g);
8264
8265               if (fdecl)
8266                 warning (0, "%Hignoring return value of %qD, "
8267                          "declared with attribute warn_unused_result",
8268                          &loc, fdecl);
8269               else
8270                 warning (0, "%Hignoring return value of function "
8271                          "declared with attribute warn_unused_result",
8272                          &loc);
8273             }
8274           break;
8275
8276         default:
8277           /* Not a container, not a call, or a call whose value is used.  */
8278           break;
8279         }
8280     }
8281 }
8282
8283 /* Convert a character from the host to the target execution character
8284    set.  cpplib handles this, mostly.  */
8285
8286 HOST_WIDE_INT
8287 c_common_to_target_charset (HOST_WIDE_INT c)
8288 {
8289   /* Character constants in GCC proper are sign-extended under -fsigned-char,
8290      zero-extended under -fno-signed-char.  cpplib insists that characters
8291      and character constants are always unsigned.  Hence we must convert
8292      back and forth.  */
8293   cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1);
8294
8295   uc = cpp_host_to_exec_charset (parse_in, uc);
8296
8297   if (flag_signed_char)
8298     return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE)
8299                                >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE);
8300   else
8301     return uc;
8302 }
8303
8304 /* Build the result of __builtin_offsetof.  EXPR is a nested sequence of
8305    component references, with STOP_REF, or alternatively an INDIRECT_REF of
8306    NULL, at the bottom; much like the traditional rendering of offsetof as a
8307    macro.  Returns the folded and properly cast result.  */
8308
8309 static tree
8310 fold_offsetof_1 (tree expr, tree stop_ref)
8311 {
8312   enum tree_code code = PLUS_EXPR;
8313   tree base, off, t;
8314
8315   if (expr == stop_ref && TREE_CODE (expr) != ERROR_MARK)
8316     return size_zero_node;
8317
8318   switch (TREE_CODE (expr))
8319     {
8320     case ERROR_MARK:
8321       return expr;
8322
8323     case VAR_DECL:
8324       error ("cannot apply %<offsetof%> to static data member %qD", expr);
8325       return error_mark_node;
8326
8327     case CALL_EXPR:
8328     case TARGET_EXPR:
8329       error ("cannot apply %<offsetof%> when %<operator[]%> is overloaded");
8330       return error_mark_node;
8331
8332     case INTEGER_CST:
8333       gcc_assert (integer_zerop (expr));
8334       return size_zero_node;
8335
8336     case NOP_EXPR:
8337     case INDIRECT_REF:
8338       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
8339       gcc_assert (base == error_mark_node || base == size_zero_node);
8340       return base;
8341
8342     case COMPONENT_REF:
8343       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
8344       if (base == error_mark_node)
8345         return base;
8346
8347       t = TREE_OPERAND (expr, 1);
8348       if (DECL_C_BIT_FIELD (t))
8349         {
8350           error ("attempt to take address of bit-field structure "
8351                  "member %qD", t);
8352           return error_mark_node;
8353         }
8354       off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t),
8355                         size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t), 1)
8356                                   / BITS_PER_UNIT));
8357       break;
8358
8359     case ARRAY_REF:
8360       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
8361       if (base == error_mark_node)
8362         return base;
8363
8364       t = TREE_OPERAND (expr, 1);
8365       if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0)
8366         {
8367           code = MINUS_EXPR;
8368           t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t);
8369         }
8370       t = convert (sizetype, t);
8371       off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
8372       break;
8373
8374     case COMPOUND_EXPR:
8375       /* Handle static members of volatile structs.  */
8376       t = TREE_OPERAND (expr, 1);
8377       gcc_assert (TREE_CODE (t) == VAR_DECL);
8378       return fold_offsetof_1 (t, stop_ref);
8379
8380     default:
8381       gcc_unreachable ();
8382     }
8383
8384   return size_binop (code, base, off);
8385 }
8386
8387 tree
8388 fold_offsetof (tree expr, tree stop_ref)
8389 {
8390   /* Convert back from the internal sizetype to size_t.  */
8391   return convert (size_type_node, fold_offsetof_1 (expr, stop_ref));
8392 }
8393
8394 /* Print an error message for an invalid lvalue.  USE says
8395    how the lvalue is being used and so selects the error message.  */
8396
8397 void
8398 lvalue_error (enum lvalue_use use)
8399 {
8400   switch (use)
8401     {
8402     case lv_assign:
8403       error ("lvalue required as left operand of assignment");
8404       break;
8405     case lv_increment:
8406       error ("lvalue required as increment operand");
8407       break;
8408     case lv_decrement:
8409       error ("lvalue required as decrement operand");
8410       break;
8411     case lv_addressof:
8412       error ("lvalue required as unary %<&%> operand");
8413       break;
8414     case lv_asm:
8415       error ("lvalue required in asm statement");
8416       break;
8417     default:
8418       gcc_unreachable ();
8419     }
8420 }
8421 \f
8422 /* *PTYPE is an incomplete array.  Complete it with a domain based on
8423    INITIAL_VALUE.  If INITIAL_VALUE is not present, use 1 if DO_DEFAULT
8424    is true.  Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered,
8425    2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty.  */
8426
8427 int
8428 complete_array_type (tree *ptype, tree initial_value, bool do_default)
8429 {
8430   tree maxindex, type, main_type, elt, unqual_elt;
8431   int failure = 0, quals;
8432   hashval_t hashcode = 0;
8433
8434   maxindex = size_zero_node;
8435   if (initial_value)
8436     {
8437       if (TREE_CODE (initial_value) == STRING_CST)
8438         {
8439           int eltsize
8440             = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value)));
8441           maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1);
8442         }
8443       else if (TREE_CODE (initial_value) == CONSTRUCTOR)
8444         {
8445           VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (initial_value);
8446
8447           if (VEC_empty (constructor_elt, v))
8448             {
8449               if (pedantic)
8450                 failure = 3;
8451               maxindex = integer_minus_one_node;
8452             }
8453           else
8454             {
8455               tree curindex;
8456               unsigned HOST_WIDE_INT cnt;
8457               constructor_elt *ce;
8458               bool fold_p = false;
8459
8460               if (VEC_index (constructor_elt, v, 0)->index)
8461                 maxindex = fold_convert (sizetype,
8462                                          VEC_index (constructor_elt,
8463                                                     v, 0)->index);
8464               curindex = maxindex;
8465
8466               for (cnt = 1;
8467                    VEC_iterate (constructor_elt, v, cnt, ce);
8468                    cnt++)
8469                 {
8470                   bool curfold_p = false;
8471                   if (ce->index)
8472                     curindex = ce->index, curfold_p = true;
8473                   else
8474                     {
8475                       if (fold_p)
8476                         curindex = fold_convert (sizetype, curindex);
8477                       curindex = size_binop (PLUS_EXPR, curindex, size_one_node);
8478                     }
8479                   if (tree_int_cst_lt (maxindex, curindex))
8480                     maxindex = curindex, fold_p = curfold_p;
8481                 }
8482                if (fold_p)
8483                  maxindex = fold_convert (sizetype, maxindex);
8484             }
8485         }
8486       else
8487         {
8488           /* Make an error message unless that happened already.  */
8489           if (initial_value != error_mark_node)
8490             failure = 1;
8491         }
8492     }
8493   else
8494     {
8495       failure = 2;
8496       if (!do_default)
8497         return failure;
8498     }
8499
8500   type = *ptype;
8501   elt = TREE_TYPE (type);
8502   quals = TYPE_QUALS (strip_array_types (elt));
8503   if (quals == 0)
8504     unqual_elt = elt;
8505   else
8506     unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
8507
8508   /* Using build_distinct_type_copy and modifying things afterward instead
8509      of using build_array_type to create a new type preserves all of the
8510      TYPE_LANG_FLAG_? bits that the front end may have set.  */
8511   main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
8512   TREE_TYPE (main_type) = unqual_elt;
8513   TYPE_DOMAIN (main_type) = build_index_type (maxindex);
8514   layout_type (main_type);
8515
8516   /* Make sure we have the canonical MAIN_TYPE. */
8517   hashcode = iterative_hash_object (TYPE_HASH (unqual_elt), hashcode);
8518   hashcode = iterative_hash_object (TYPE_HASH (TYPE_DOMAIN (main_type)),
8519                                     hashcode);
8520   main_type = type_hash_canon (hashcode, main_type);
8521
8522   /* Fix the canonical type.  */
8523   if (TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (main_type))
8524       || TYPE_STRUCTURAL_EQUALITY_P (TYPE_DOMAIN (main_type)))
8525     SET_TYPE_STRUCTURAL_EQUALITY (main_type);
8526   else if (TYPE_CANONICAL (TREE_TYPE (main_type)) != TREE_TYPE (main_type)
8527            || (TYPE_CANONICAL (TYPE_DOMAIN (main_type))
8528                != TYPE_DOMAIN (main_type)))
8529     TYPE_CANONICAL (main_type)
8530       = build_array_type (TYPE_CANONICAL (TREE_TYPE (main_type)),
8531                           TYPE_CANONICAL (TYPE_DOMAIN (main_type)));
8532   else
8533     TYPE_CANONICAL (main_type) = main_type;
8534
8535   if (quals == 0)
8536     type = main_type;
8537   else
8538     type = c_build_qualified_type (main_type, quals);
8539
8540   if (COMPLETE_TYPE_P (type)
8541       && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST
8542       && TREE_OVERFLOW (TYPE_SIZE_UNIT (type)))
8543     {
8544       error ("size of array is too large");
8545       /* If we proceed with the array type as it is, we'll eventually
8546          crash in tree_low_cst().  */
8547       type = error_mark_node;
8548     }
8549
8550   *ptype = type;
8551   return failure;
8552 }
8553
8554 \f
8555 /* Used to help initialize the builtin-types.def table.  When a type of
8556    the correct size doesn't exist, use error_mark_node instead of NULL.
8557    The later results in segfaults even when a decl using the type doesn't
8558    get invoked.  */
8559
8560 tree
8561 builtin_type_for_size (int size, bool unsignedp)
8562 {
8563   tree type = lang_hooks.types.type_for_size (size, unsignedp);
8564   return type ? type : error_mark_node;
8565 }
8566
8567 /* A helper function for resolve_overloaded_builtin in resolving the
8568    overloaded __sync_ builtins.  Returns a positive power of 2 if the
8569    first operand of PARAMS is a pointer to a supported data type.
8570    Returns 0 if an error is encountered.  */
8571
8572 static int
8573 sync_resolve_size (tree function, VEC(tree,gc) *params)
8574 {
8575   tree type;
8576   int size;
8577
8578   if (VEC_empty (tree, params))
8579     {
8580       error ("too few arguments to function %qE", function);
8581       return 0;
8582     }
8583
8584   type = TREE_TYPE (VEC_index (tree, params, 0));
8585   if (TREE_CODE (type) != POINTER_TYPE)
8586     goto incompatible;
8587
8588   type = TREE_TYPE (type);
8589   if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
8590     goto incompatible;
8591
8592   size = tree_low_cst (TYPE_SIZE_UNIT (type), 1);
8593   if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16)
8594     return size;
8595
8596  incompatible:
8597   error ("incompatible type for argument %d of %qE", 1, function);
8598   return 0;
8599 }
8600
8601 /* A helper function for resolve_overloaded_builtin.  Adds casts to
8602    PARAMS to make arguments match up with those of FUNCTION.  Drops
8603    the variadic arguments at the end.  Returns false if some error
8604    was encountered; true on success.  */
8605
8606 static bool
8607 sync_resolve_params (tree orig_function, tree function, VEC(tree, gc) *params)
8608 {
8609   tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (function));
8610   tree ptype;
8611   int number;
8612   unsigned int parmnum;
8613
8614   /* We've declared the implementation functions to use "volatile void *"
8615      as the pointer parameter, so we shouldn't get any complaints from the
8616      call to check_function_arguments what ever type the user used.  */
8617   arg_types = TREE_CHAIN (arg_types);
8618   ptype = TREE_TYPE (TREE_TYPE (VEC_index (tree, params, 0)));
8619   number = 2;
8620
8621   /* For the rest of the values, we need to cast these to FTYPE, so that we
8622      don't get warnings for passing pointer types, etc.  */
8623   parmnum = 0;
8624   while (arg_types != void_list_node)
8625     {
8626       tree val;
8627
8628       ++parmnum;
8629       if (VEC_length (tree, params) <= parmnum)
8630         {
8631           error ("too few arguments to function %qE", orig_function);
8632           return false;
8633         }
8634
8635       /* ??? Ideally for the first conversion we'd use convert_for_assignment
8636          so that we get warnings for anything that doesn't match the pointer
8637          type.  This isn't portable across the C and C++ front ends atm.  */
8638       val = VEC_index (tree, params, parmnum);
8639       val = convert (ptype, val);
8640       val = convert (TREE_VALUE (arg_types), val);
8641       VEC_replace (tree, params, parmnum, val);
8642
8643       arg_types = TREE_CHAIN (arg_types);
8644       number++;
8645     }
8646
8647   /* The definition of these primitives is variadic, with the remaining
8648      being "an optional list of variables protected by the memory barrier".
8649      No clue what that's supposed to mean, precisely, but we consider all
8650      call-clobbered variables to be protected so we're safe.  */
8651   VEC_truncate (tree, params, parmnum + 1);
8652
8653   return true;
8654 }
8655
8656 /* A helper function for resolve_overloaded_builtin.  Adds a cast to
8657    RESULT to make it match the type of the first pointer argument in
8658    PARAMS.  */
8659
8660 static tree
8661 sync_resolve_return (tree first_param, tree result)
8662 {
8663   tree ptype = TREE_TYPE (TREE_TYPE (first_param));
8664   ptype = TYPE_MAIN_VARIANT (ptype);
8665   return convert (ptype, result);
8666 }
8667
8668 /* Some builtin functions are placeholders for other expressions.  This
8669    function should be called immediately after parsing the call expression
8670    before surrounding code has committed to the type of the expression.
8671
8672    LOC is the location of the builtin call.
8673
8674    FUNCTION is the DECL that has been invoked; it is known to be a builtin.
8675    PARAMS is the argument list for the call.  The return value is non-null
8676    when expansion is complete, and null if normal processing should
8677    continue.  */
8678
8679 tree
8680 resolve_overloaded_builtin (location_t loc, tree function, VEC(tree,gc) *params)
8681 {
8682   enum built_in_function orig_code = DECL_FUNCTION_CODE (function);
8683   switch (DECL_BUILT_IN_CLASS (function))
8684     {
8685     case BUILT_IN_NORMAL:
8686       break;
8687     case BUILT_IN_MD:
8688       if (targetm.resolve_overloaded_builtin)
8689         return targetm.resolve_overloaded_builtin (loc, function, params);
8690       else
8691         return NULL_TREE;
8692     default:
8693       return NULL_TREE;
8694     }
8695
8696   /* Handle BUILT_IN_NORMAL here.  */
8697   switch (orig_code)
8698     {
8699     case BUILT_IN_FETCH_AND_ADD_N:
8700     case BUILT_IN_FETCH_AND_SUB_N:
8701     case BUILT_IN_FETCH_AND_OR_N:
8702     case BUILT_IN_FETCH_AND_AND_N:
8703     case BUILT_IN_FETCH_AND_XOR_N:
8704     case BUILT_IN_FETCH_AND_NAND_N:
8705     case BUILT_IN_ADD_AND_FETCH_N:
8706     case BUILT_IN_SUB_AND_FETCH_N:
8707     case BUILT_IN_OR_AND_FETCH_N:
8708     case BUILT_IN_AND_AND_FETCH_N:
8709     case BUILT_IN_XOR_AND_FETCH_N:
8710     case BUILT_IN_NAND_AND_FETCH_N:
8711     case BUILT_IN_BOOL_COMPARE_AND_SWAP_N:
8712     case BUILT_IN_VAL_COMPARE_AND_SWAP_N:
8713     case BUILT_IN_LOCK_TEST_AND_SET_N:
8714     case BUILT_IN_LOCK_RELEASE_N:
8715       {
8716         int n = sync_resolve_size (function, params);
8717         tree new_function, first_param, result;
8718
8719         if (n == 0)
8720           return error_mark_node;
8721
8722         new_function = built_in_decls[orig_code + exact_log2 (n) + 1];
8723         if (!sync_resolve_params (function, new_function, params))
8724           return error_mark_node;
8725
8726         first_param = VEC_index (tree, params, 0);
8727         result = build_function_call_vec (loc, new_function, params, NULL);
8728         if (orig_code != BUILT_IN_BOOL_COMPARE_AND_SWAP_N
8729             && orig_code != BUILT_IN_LOCK_RELEASE_N)
8730           result = sync_resolve_return (first_param, result);
8731
8732         return result;
8733       }
8734
8735     default:
8736       return NULL_TREE;
8737     }
8738 }
8739
8740 /* Ignoring their sign, return true if two scalar types are the same.  */
8741 bool
8742 same_scalar_type_ignoring_signedness (tree t1, tree t2)
8743 {
8744   enum tree_code c1 = TREE_CODE (t1), c2 = TREE_CODE (t2);
8745
8746   gcc_assert ((c1 == INTEGER_TYPE || c1 == REAL_TYPE || c1 == FIXED_POINT_TYPE)
8747               && (c2 == INTEGER_TYPE || c2 == REAL_TYPE
8748                   || c2 == FIXED_POINT_TYPE));
8749
8750   /* Equality works here because c_common_signed_type uses
8751      TYPE_MAIN_VARIANT.  */
8752   return c_common_signed_type (t1)
8753     == c_common_signed_type (t2);
8754 }
8755
8756 /* Check for missing format attributes on function pointers.  LTYPE is
8757    the new type or left-hand side type.  RTYPE is the old type or
8758    right-hand side type.  Returns TRUE if LTYPE is missing the desired
8759    attribute.  */
8760
8761 bool
8762 check_missing_format_attribute (tree ltype, tree rtype)
8763 {
8764   tree const ttr = TREE_TYPE (rtype), ttl = TREE_TYPE (ltype);
8765   tree ra;
8766
8767   for (ra = TYPE_ATTRIBUTES (ttr); ra; ra = TREE_CHAIN (ra))
8768     if (is_attribute_p ("format", TREE_PURPOSE (ra)))
8769       break;
8770   if (ra)
8771     {
8772       tree la;
8773       for (la = TYPE_ATTRIBUTES (ttl); la; la = TREE_CHAIN (la))
8774         if (is_attribute_p ("format", TREE_PURPOSE (la)))
8775           break;
8776       return !la;
8777     }
8778   else
8779     return false;
8780 }
8781
8782 /* Subscripting with type char is likely to lose on a machine where
8783    chars are signed.  So warn on any machine, but optionally.  Don't
8784    warn for unsigned char since that type is safe.  Don't warn for
8785    signed char because anyone who uses that must have done so
8786    deliberately. Furthermore, we reduce the false positive load by
8787    warning only for non-constant value of type char.  */
8788
8789 void
8790 warn_array_subscript_with_type_char (tree index)
8791 {
8792   if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node
8793       && TREE_CODE (index) != INTEGER_CST)
8794     warning (OPT_Wchar_subscripts, "array subscript has type %<char%>");
8795 }
8796
8797 /* Implement -Wparentheses for the unexpected C precedence rules, to
8798    cover cases like x + y << z which readers are likely to
8799    misinterpret.  We have seen an expression in which CODE is a binary
8800    operator used to combine expressions ARG_LEFT and ARG_RIGHT, which
8801    before folding had CODE_LEFT and CODE_RIGHT.  CODE_LEFT and
8802    CODE_RIGHT may be ERROR_MARK, which means that that side of the
8803    expression was not formed using a binary or unary operator, or it
8804    was enclosed in parentheses.  */
8805
8806 void
8807 warn_about_parentheses (enum tree_code code,
8808                         enum tree_code code_left, tree arg_left,
8809                         enum tree_code code_right, tree arg_right)
8810 {
8811   if (!warn_parentheses)
8812     return;
8813
8814   /* This macro tests that the expression ARG with original tree code
8815      CODE appears to be a boolean expression. or the result of folding a
8816      boolean expression.  */
8817 #define APPEARS_TO_BE_BOOLEAN_EXPR_P(CODE, ARG)                             \
8818         (truth_value_p (TREE_CODE (ARG))                                    \
8819          || TREE_CODE (TREE_TYPE (ARG)) == BOOLEAN_TYPE                     \
8820          /* Folding may create 0 or 1 integers from other expressions.  */  \
8821          || ((CODE) != INTEGER_CST                                          \
8822              && (integer_onep (ARG) || integer_zerop (ARG))))
8823
8824   switch (code)
8825     {
8826     case LSHIFT_EXPR:
8827       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8828         warning (OPT_Wparentheses,
8829                  "suggest parentheses around %<+%> inside %<<<%>");
8830       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8831         warning (OPT_Wparentheses,
8832                  "suggest parentheses around %<-%> inside %<<<%>");
8833       return;
8834
8835     case RSHIFT_EXPR:
8836       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8837         warning (OPT_Wparentheses,
8838                  "suggest parentheses around %<+%> inside %<>>%>");
8839       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8840         warning (OPT_Wparentheses,
8841                  "suggest parentheses around %<-%> inside %<>>%>");
8842       return;
8843
8844     case TRUTH_ORIF_EXPR:
8845       if (code_left == TRUTH_ANDIF_EXPR || code_right == TRUTH_ANDIF_EXPR)
8846         warning (OPT_Wparentheses,
8847                  "suggest parentheses around %<&&%> within %<||%>");
8848       return;
8849
8850     case BIT_IOR_EXPR:
8851       if (code_left == BIT_AND_EXPR || code_left == BIT_XOR_EXPR
8852           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
8853           || code_right == BIT_AND_EXPR || code_right == BIT_XOR_EXPR
8854           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
8855         warning (OPT_Wparentheses,
8856                  "suggest parentheses around arithmetic in operand of %<|%>");
8857       /* Check cases like x|y==z */
8858       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8859                || TREE_CODE_CLASS (code_right) == tcc_comparison)
8860         warning (OPT_Wparentheses,
8861                  "suggest parentheses around comparison in operand of %<|%>");
8862       /* Check cases like !x | y */
8863       else if (code_left == TRUTH_NOT_EXPR
8864                && !APPEARS_TO_BE_BOOLEAN_EXPR_P (code_right, arg_right))
8865         warning (OPT_Wparentheses, "suggest parentheses around operand of "
8866                  "%<!%> or change %<|%> to %<||%> or %<!%> to %<~%>");
8867       return;
8868
8869     case BIT_XOR_EXPR:
8870       if (code_left == BIT_AND_EXPR
8871           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
8872           || code_right == BIT_AND_EXPR
8873           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
8874         warning (OPT_Wparentheses,
8875                  "suggest parentheses around arithmetic in operand of %<^%>");
8876       /* Check cases like x^y==z */
8877       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8878                || TREE_CODE_CLASS (code_right) == tcc_comparison)
8879         warning (OPT_Wparentheses,
8880                  "suggest parentheses around comparison in operand of %<^%>");
8881       return;
8882
8883     case BIT_AND_EXPR:
8884       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8885         warning (OPT_Wparentheses,
8886                  "suggest parentheses around %<+%> in operand of %<&%>");
8887       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8888         warning (OPT_Wparentheses,
8889                  "suggest parentheses around %<-%> in operand of %<&%>");
8890       /* Check cases like x&y==z */
8891       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8892                || TREE_CODE_CLASS (code_right) == tcc_comparison)
8893         warning (OPT_Wparentheses,
8894                  "suggest parentheses around comparison in operand of %<&%>");
8895       /* Check cases like !x & y */
8896       else if (code_left == TRUTH_NOT_EXPR
8897                && !APPEARS_TO_BE_BOOLEAN_EXPR_P (code_right, arg_right))
8898         warning (OPT_Wparentheses, "suggest parentheses around operand of "
8899                  "%<!%> or change %<&%> to %<&&%> or %<!%> to %<~%>");
8900       return;
8901
8902     case EQ_EXPR:
8903       if (TREE_CODE_CLASS (code_left) == tcc_comparison
8904           || TREE_CODE_CLASS (code_right) == tcc_comparison)
8905         warning (OPT_Wparentheses,
8906                  "suggest parentheses around comparison in operand of %<==%>");
8907       return;
8908     case NE_EXPR:
8909       if (TREE_CODE_CLASS (code_left) == tcc_comparison
8910           || TREE_CODE_CLASS (code_right) == tcc_comparison)
8911         warning (OPT_Wparentheses,
8912                  "suggest parentheses around comparison in operand of %<!=%>");
8913       return;
8914
8915     default:
8916       if (TREE_CODE_CLASS (code) == tcc_comparison
8917            && ((TREE_CODE_CLASS (code_left) == tcc_comparison
8918                 && code_left != NE_EXPR && code_left != EQ_EXPR
8919                 && INTEGRAL_TYPE_P (TREE_TYPE (arg_left)))
8920                || (TREE_CODE_CLASS (code_right) == tcc_comparison
8921                    && code_right != NE_EXPR && code_right != EQ_EXPR
8922                    && INTEGRAL_TYPE_P (TREE_TYPE (arg_right)))))
8923         warning (OPT_Wparentheses, "comparisons like %<X<=Y<=Z%> do not "
8924                  "have their mathematical meaning");
8925       return;
8926     }
8927 #undef NOT_A_BOOLEAN_EXPR_P
8928 }
8929
8930 /* If LABEL (a LABEL_DECL) has not been used, issue a warning.  */
8931
8932 void
8933 warn_for_unused_label (tree label)
8934 {
8935   if (!TREE_USED (label))
8936     {
8937       if (DECL_INITIAL (label))
8938         warning (OPT_Wunused_label, "label %q+D defined but not used", label);
8939       else
8940         warning (OPT_Wunused_label, "label %q+D declared but not defined", label);
8941     }
8942 }
8943
8944 #ifndef TARGET_HAS_TARGETCM
8945 struct gcc_targetcm targetcm = TARGETCM_INITIALIZER;
8946 #endif
8947
8948 /* Warn for division by zero according to the value of DIVISOR.  LOC
8949    is the location of the division operator.  */
8950
8951 void
8952 warn_for_div_by_zero (location_t loc, tree divisor)
8953 {
8954   /* If DIVISOR is zero, and has integral or fixed-point type, issue a warning
8955      about division by zero.  Do not issue a warning if DIVISOR has a
8956      floating-point type, since we consider 0.0/0.0 a valid way of
8957      generating a NaN.  */
8958   if (c_inhibit_evaluation_warnings == 0
8959       && (integer_zerop (divisor) || fixed_zerop (divisor)))
8960     warning_at (loc, OPT_Wdiv_by_zero, "division by zero");
8961 }
8962
8963 /* Subroutine of build_binary_op. Give warnings for comparisons
8964    between signed and unsigned quantities that may fail. Do the
8965    checking based on the original operand trees ORIG_OP0 and ORIG_OP1,
8966    so that casts will be considered, but default promotions won't
8967    be.
8968
8969    LOCATION is the location of the comparison operator.
8970
8971    The arguments of this function map directly to local variables
8972    of build_binary_op.  */
8973
8974 void
8975 warn_for_sign_compare (location_t location,
8976                        tree orig_op0, tree orig_op1,
8977                        tree op0, tree op1,
8978                        tree result_type, enum tree_code resultcode)
8979 {
8980   int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
8981   int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
8982   int unsignedp0, unsignedp1;
8983
8984   /* In C++, check for comparison of different enum types.  */
8985   if (c_dialect_cxx()
8986       && TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
8987       && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
8988       && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
8989          != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
8990     {
8991       warning_at (location,
8992                   OPT_Wsign_compare, "comparison between types %qT and %qT",
8993                   TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
8994     }
8995
8996   /* Do not warn if the comparison is being done in a signed type,
8997      since the signed type will only be chosen if it can represent
8998      all the values of the unsigned type.  */
8999   if (!TYPE_UNSIGNED (result_type))
9000     /* OK */;
9001   /* Do not warn if both operands are unsigned.  */
9002   else if (op0_signed == op1_signed)
9003     /* OK */;
9004   else
9005     {
9006       tree sop, uop, base_type;
9007       bool ovf;
9008
9009       if (op0_signed)
9010         sop = orig_op0, uop = orig_op1;
9011       else
9012         sop = orig_op1, uop = orig_op0;
9013
9014       STRIP_TYPE_NOPS (sop);
9015       STRIP_TYPE_NOPS (uop);
9016       base_type = (TREE_CODE (result_type) == COMPLEX_TYPE
9017                    ? TREE_TYPE (result_type) : result_type);
9018
9019       /* Do not warn if the signed quantity is an unsuffixed integer
9020          literal (or some static constant expression involving such
9021          literals or a conditional expression involving such literals)
9022          and it is non-negative.  */
9023       if (tree_expr_nonnegative_warnv_p (sop, &ovf))
9024         /* OK */;
9025       /* Do not warn if the comparison is an equality operation, the
9026          unsigned quantity is an integral constant, and it would fit
9027          in the result if the result were signed.  */
9028       else if (TREE_CODE (uop) == INTEGER_CST
9029                && (resultcode == EQ_EXPR || resultcode == NE_EXPR)
9030                && int_fits_type_p (uop, c_common_signed_type (base_type)))
9031         /* OK */;
9032       /* In C, do not warn if the unsigned quantity is an enumeration
9033          constant and its maximum value would fit in the result if the
9034          result were signed.  */
9035       else if (!c_dialect_cxx() && TREE_CODE (uop) == INTEGER_CST
9036                && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE
9037                && int_fits_type_p (TYPE_MAX_VALUE (TREE_TYPE (uop)),
9038                                    c_common_signed_type (base_type)))
9039         /* OK */;
9040       else
9041         warning_at (location,
9042                     OPT_Wsign_compare,
9043                     "comparison between signed and unsigned integer expressions");
9044     }
9045
9046   /* Warn if two unsigned values are being compared in a size larger
9047      than their original size, and one (and only one) is the result of
9048      a `~' operator.  This comparison will always fail.
9049
9050      Also warn if one operand is a constant, and the constant does not
9051      have all bits set that are set in the ~ operand when it is
9052      extended.  */
9053
9054   op0 = get_narrower (op0, &unsignedp0);
9055   op1 = get_narrower (op1, &unsignedp1);
9056
9057   if ((TREE_CODE (op0) == BIT_NOT_EXPR)
9058       ^ (TREE_CODE (op1) == BIT_NOT_EXPR))
9059     {
9060       if (TREE_CODE (op0) == BIT_NOT_EXPR)
9061         op0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
9062       if (TREE_CODE (op1) == BIT_NOT_EXPR)
9063         op1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
9064
9065       if (host_integerp (op0, 0) || host_integerp (op1, 0))
9066         {
9067           tree primop;
9068           HOST_WIDE_INT constant, mask;
9069           int unsignedp;
9070           unsigned int bits;
9071
9072           if (host_integerp (op0, 0))
9073             {
9074               primop = op1;
9075               unsignedp = unsignedp1;
9076               constant = tree_low_cst (op0, 0);
9077             }
9078           else
9079             {
9080               primop = op0;
9081               unsignedp = unsignedp0;
9082               constant = tree_low_cst (op1, 0);
9083             }
9084
9085           bits = TYPE_PRECISION (TREE_TYPE (primop));
9086           if (bits < TYPE_PRECISION (result_type)
9087               && bits < HOST_BITS_PER_LONG && unsignedp)
9088             {
9089               mask = (~ (HOST_WIDE_INT) 0) << bits;
9090               if ((mask & constant) != mask)
9091                 {
9092                   if (constant == 0)
9093                     warning (OPT_Wsign_compare,
9094                              "promoted ~unsigned is always non-zero");
9095                   else
9096                     warning_at (location, OPT_Wsign_compare,
9097                                 "comparison of promoted ~unsigned with constant");
9098                 }
9099             }
9100         }
9101       else if (unsignedp0 && unsignedp1
9102                && (TYPE_PRECISION (TREE_TYPE (op0))
9103                    < TYPE_PRECISION (result_type))
9104                && (TYPE_PRECISION (TREE_TYPE (op1))
9105                    < TYPE_PRECISION (result_type)))
9106         warning_at (location, OPT_Wsign_compare,
9107                  "comparison of promoted ~unsigned with unsigned");
9108     }
9109 }
9110
9111 /* Setup a TYPE_DECL node as a typedef representation.
9112
9113    X is a TYPE_DECL for a typedef statement.  Create a brand new
9114    ..._TYPE node (which will be just a variant of the existing
9115    ..._TYPE node with identical properties) and then install X
9116    as the TYPE_NAME of this brand new (duplicate) ..._TYPE node.
9117
9118    The whole point here is to end up with a situation where each
9119    and every ..._TYPE node the compiler creates will be uniquely
9120    associated with AT MOST one node representing a typedef name.
9121    This way, even though the compiler substitutes corresponding
9122    ..._TYPE nodes for TYPE_DECL (i.e. "typedef name") nodes very
9123    early on, later parts of the compiler can always do the reverse
9124    translation and get back the corresponding typedef name.  For
9125    example, given:
9126
9127         typedef struct S MY_TYPE;
9128         MY_TYPE object;
9129
9130    Later parts of the compiler might only know that `object' was of
9131    type `struct S' if it were not for code just below.  With this
9132    code however, later parts of the compiler see something like:
9133
9134         struct S' == struct S
9135         typedef struct S' MY_TYPE;
9136         struct S' object;
9137
9138     And they can then deduce (from the node for type struct S') that
9139     the original object declaration was:
9140
9141                 MY_TYPE object;
9142
9143     Being able to do this is important for proper support of protoize,
9144     and also for generating precise symbolic debugging information
9145     which takes full account of the programmer's (typedef) vocabulary.
9146
9147     Obviously, we don't want to generate a duplicate ..._TYPE node if
9148     the TYPE_DECL node that we are now processing really represents a
9149     standard built-in type.  */
9150
9151 void
9152 set_underlying_type (tree x)
9153 {
9154   if (x == error_mark_node)
9155     return;
9156   if (DECL_IS_BUILTIN (x))
9157     {
9158       if (TYPE_NAME (TREE_TYPE (x)) == 0)
9159         TYPE_NAME (TREE_TYPE (x)) = x;
9160     }
9161   else if (TREE_TYPE (x) != error_mark_node
9162            && DECL_ORIGINAL_TYPE (x) == NULL_TREE)
9163     {
9164       tree tt = TREE_TYPE (x);
9165       DECL_ORIGINAL_TYPE (x) = tt;
9166       tt = build_variant_type_copy (tt);
9167       TYPE_STUB_DECL (tt) = TYPE_STUB_DECL (DECL_ORIGINAL_TYPE (x));
9168       TYPE_NAME (tt) = x;
9169       TREE_USED (tt) = TREE_USED (x);
9170       TREE_TYPE (x) = tt;
9171     }
9172 }
9173
9174 /* Returns true if X is a typedef decl.  */
9175
9176 bool
9177 is_typedef_decl (tree x)
9178 {
9179   return (x && TREE_CODE (x) == TYPE_DECL
9180           && DECL_ORIGINAL_TYPE (x) != NULL_TREE);
9181 }
9182
9183 /* The C and C++ parsers both use vectors to hold function arguments.
9184    For efficiency, we keep a cache of unused vectors.  This is the
9185    cache.  */
9186
9187 typedef VEC(tree,gc)* tree_gc_vec;
9188 DEF_VEC_P(tree_gc_vec);
9189 DEF_VEC_ALLOC_P(tree_gc_vec,gc);
9190 static GTY((deletable)) VEC(tree_gc_vec,gc) *tree_vector_cache;
9191
9192 /* Return a new vector from the cache.  If the cache is empty,
9193    allocate a new vector.  These vectors are GC'ed, so it is OK if the
9194    pointer is not released..  */
9195
9196 VEC(tree,gc) *
9197 make_tree_vector (void)
9198 {
9199   if (!VEC_empty (tree_gc_vec, tree_vector_cache))
9200     return VEC_pop (tree_gc_vec, tree_vector_cache);
9201   else
9202     {
9203       /* Passing 0 to VEC_alloc returns NULL, and our callers require
9204          that we always return a non-NULL value.  The vector code uses
9205          4 when growing a NULL vector, so we do too.  */
9206       return VEC_alloc (tree, gc, 4);
9207     }
9208 }
9209
9210 /* Release a vector of trees back to the cache.  */
9211
9212 void
9213 release_tree_vector (VEC(tree,gc) *vec)
9214 {
9215   if (vec != NULL)
9216     {
9217       VEC_truncate (tree, vec, 0);
9218       VEC_safe_push (tree_gc_vec, gc, tree_vector_cache, vec);
9219     }
9220 }
9221
9222 /* Get a new tree vector holding a single tree.  */
9223
9224 VEC(tree,gc) *
9225 make_tree_vector_single (tree t)
9226 {
9227   VEC(tree,gc) *ret = make_tree_vector ();
9228   VEC_quick_push (tree, ret, t);
9229   return ret;
9230 }
9231
9232 /* Get a new tree vector which is a copy of an existing one.  */
9233
9234 VEC(tree,gc) *
9235 make_tree_vector_copy (const VEC(tree,gc) *orig)
9236 {
9237   VEC(tree,gc) *ret;
9238   unsigned int ix;
9239   tree t;
9240
9241   ret = make_tree_vector ();
9242   VEC_reserve (tree, gc, ret, VEC_length (tree, orig));
9243   for (ix = 0; VEC_iterate (tree, orig, ix, t); ++ix)
9244     VEC_quick_push (tree, ret, t);
9245   return ret;
9246 }
9247
9248 #include "gt-c-common.h"