gcc/c-common.c

   1 /* Subroutines shared by all languages that are variants of C.
   2    Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
   3    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
   4    Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "intl.h"
  27 #include "tree.h"
  28 #include "flags.h"
  29 #include "output.h"
  30 #include "c-pragma.h"
  31 #include "rtl.h"
  32 #include "ggc.h"
  33 #include "varray.h"
  34 #include "expr.h"
  35 #include "c-common.h"
  36 #include "tm_p.h"
  37 #include "obstack.h"
  38 #include "cpplib.h"
  39 #include "target.h"
  40 #include "langhooks.h"
  41 #include "tree-inline.h"
  42 #include "c-tree.h"
  43 #include "toplev.h"
  44 #include "diagnostic.h"
  45 #include "tree-iterator.h"
  46 #include "hashtab.h"
  47 #include "tree-mudflap.h"
  48 #include "opts.h"
  49 #include "real.h"
  50 #include "cgraph.h"
  51 #include "target-def.h"
  52 #include "gimple.h"
  53 #include "fixed-value.h"
  54 #include "libfuncs.h"
  55
  56 cpp_reader *parse_in;           /* Declared in c-pragma.h.  */
  57
  58 /* The following symbols are subsumed in the c_global_trees array, and
  59    listed here individually for documentation purposes.
  60
  61    INTEGER_TYPE and REAL_TYPE nodes for the standard data types.
  62
  63         tree short_integer_type_node;
  64         tree long_integer_type_node;
  65         tree long_long_integer_type_node;
  66
  67         tree short_unsigned_type_node;
  68         tree long_unsigned_type_node;
  69         tree long_long_unsigned_type_node;
  70
  71         tree truthvalue_type_node;
  72         tree truthvalue_false_node;
  73         tree truthvalue_true_node;
  74
  75         tree ptrdiff_type_node;
  76
  77         tree unsigned_char_type_node;
  78         tree signed_char_type_node;
  79         tree wchar_type_node;
  80
  81         tree char16_type_node;
  82         tree char32_type_node;
  83
  84         tree float_type_node;
  85         tree double_type_node;
  86         tree long_double_type_node;
  87
  88         tree complex_integer_type_node;
  89         tree complex_float_type_node;
  90         tree complex_double_type_node;
  91         tree complex_long_double_type_node;
  92
  93         tree dfloat32_type_node;
  94         tree dfloat64_type_node;
  95         tree_dfloat128_type_node;
  96
  97         tree intQI_type_node;
  98         tree intHI_type_node;
  99         tree intSI_type_node;
 100         tree intDI_type_node;
 101         tree intTI_type_node;
 102
 103         tree unsigned_intQI_type_node;
 104         tree unsigned_intHI_type_node;
 105         tree unsigned_intSI_type_node;
 106         tree unsigned_intDI_type_node;
 107         tree unsigned_intTI_type_node;
 108
 109         tree widest_integer_literal_type_node;
 110         tree widest_unsigned_literal_type_node;
 111
 112    Nodes for types `void *' and `const void *'.
 113
 114         tree ptr_type_node, const_ptr_type_node;
 115
 116    Nodes for types `char *' and `const char *'.
 117
 118         tree string_type_node, const_string_type_node;
 119
 120    Type `char[SOMENUMBER]'.
 121    Used when an array of char is needed and the size is irrelevant.
 122
 123         tree char_array_type_node;
 124
 125    Type `int[SOMENUMBER]' or something like it.
 126    Used when an array of int needed and the size is irrelevant.
 127
 128         tree int_array_type_node;
 129
 130    Type `wchar_t[SOMENUMBER]' or something like it.
 131    Used when a wide string literal is created.
 132
 133         tree wchar_array_type_node;
 134
 135    Type `char16_t[SOMENUMBER]' or something like it.
 136    Used when a UTF-16 string literal is created.
 137
 138         tree char16_array_type_node;
 139
 140    Type `char32_t[SOMENUMBER]' or something like it.
 141    Used when a UTF-32 string literal is created.
 142
 143         tree char32_array_type_node;
 144
 145    Type `int ()' -- used for implicit declaration of functions.
 146
 147         tree default_function_type;
 148
 149    A VOID_TYPE node, packaged in a TREE_LIST.
 150
 151         tree void_list_node;
 152
 153   The lazily created VAR_DECLs for __FUNCTION__, __PRETTY_FUNCTION__,
 154   and __func__. (C doesn't generate __FUNCTION__ and__PRETTY_FUNCTION__
 155   VAR_DECLS, but C++ does.)
 156
 157         tree function_name_decl_node;
 158         tree pretty_function_name_decl_node;
 159         tree c99_function_name_decl_node;
 160
 161   Stack of nested function name VAR_DECLs.
 162
 163         tree saved_function_name_decls;
 164
 165 */
 166
 167 tree c_global_trees[CTI_MAX];
 168 \f
 169 /* Switches common to the C front ends.  */
 170
 171 /* Nonzero if preprocessing only.  */
 172
 173 int flag_preprocess_only;
 174
 175 /* Nonzero means don't output line number information.  */
 176
 177 char flag_no_line_commands;
 178
 179 /* Nonzero causes -E output not to be done, but directives such as
 180    #define that have side effects are still obeyed.  */
 181
 182 char flag_no_output;
 183
 184 /* Nonzero means dump macros in some fashion.  */
 185
 186 char flag_dump_macros;
 187
 188 /* Nonzero means pass #include lines through to the output.  */
 189
 190 char flag_dump_includes;
 191
 192 /* Nonzero means process PCH files while preprocessing.  */
 193
 194 bool flag_pch_preprocess;
 195
 196 /* The file name to which we should write a precompiled header, or
 197    NULL if no header will be written in this compile.  */
 198
 199 const char *pch_file;
 200
 201 /* Nonzero if an ISO standard was selected.  It rejects macros in the
 202    user's namespace.  */
 203 int flag_iso;
 204
 205 /* Nonzero if -undef was given.  It suppresses target built-in macros
 206    and assertions.  */
 207 int flag_undef;
 208
 209 /* Nonzero means don't recognize the non-ANSI builtin functions.  */
 210
 211 int flag_no_builtin;
 212
 213 /* Nonzero means don't recognize the non-ANSI builtin functions.
 214    -ansi sets this.  */
 215
 216 int flag_no_nonansi_builtin;
 217
 218 /* Nonzero means give `double' the same size as `float'.  */
 219
 220 int flag_short_double;
 221
 222 /* Nonzero means give `wchar_t' the same size as `short'.  */
 223
 224 int flag_short_wchar;
 225
 226 /* Nonzero means allow implicit conversions between vectors with
 227    differing numbers of subparts and/or differing element types.  */
 228 int flag_lax_vector_conversions;
 229
 230 /* Nonzero means allow Microsoft extensions without warnings or errors.  */
 231 int flag_ms_extensions;
 232
 233 /* Nonzero means don't recognize the keyword `asm'.  */
 234
 235 int flag_no_asm;
 236
 237 /* Nonzero means to treat bitfields as signed unless they say `unsigned'.  */
 238
 239 int flag_signed_bitfields = 1;
 240
 241 /* Warn about #pragma directives that are not recognized.  */
 242
 243 int warn_unknown_pragmas; /* Tri state variable.  */
 244
 245 /* Warn about format/argument anomalies in calls to formatted I/O functions
 246    (*printf, *scanf, strftime, strfmon, etc.).  */
 247
 248 int warn_format;
 249
 250 /* Warn about using __null (as NULL in C++) as sentinel.  For code compiled
 251    with GCC this doesn't matter as __null is guaranteed to have the right
 252    size.  */
 253
 254 int warn_strict_null_sentinel;
 255
 256 /* Zero means that faster, ...NonNil variants of objc_msgSend...
 257    calls will be used in ObjC; passing nil receivers to such calls
 258    will most likely result in crashes.  */
 259 int flag_nil_receivers = 1;
 260
 261 /* Nonzero means that code generation will be altered to support
 262    "zero-link" execution.  This currently affects ObjC only, but may
 263    affect other languages in the future.  */
 264 int flag_zero_link = 0;
 265
 266 /* Nonzero means emit an '__OBJC, __image_info' for the current translation
 267    unit.  It will inform the ObjC runtime that class definition(s) herein
 268    contained are to replace one(s) previously loaded.  */
 269 int flag_replace_objc_classes = 0;
 270
 271 /* C/ObjC language option variables.  */
 272
 273
 274 /* Nonzero means allow type mismatches in conditional expressions;
 275    just make their values `void'.  */
 276
 277 int flag_cond_mismatch;
 278
 279 /* Nonzero means enable C89 Amendment 1 features.  */
 280
 281 int flag_isoc94;
 282
 283 /* Nonzero means use the ISO C99 dialect of C.  */
 284
 285 int flag_isoc99;
 286
 287 /* Nonzero means that we have builtin functions, and main is an int.  */
 288
 289 int flag_hosted = 1;
 290
 291
 292 /* ObjC language option variables.  */
 293
 294
 295 /* Open and close the file for outputting class declarations, if
 296    requested (ObjC).  */
 297
 298 int flag_gen_declaration;
 299
 300 /* Tells the compiler that this is a special run.  Do not perform any
 301    compiling, instead we are to test some platform dependent features
 302    and output a C header file with appropriate definitions.  */
 303
 304 int print_struct_values;
 305
 306 /* Tells the compiler what is the constant string class for ObjC.  */
 307
 308 const char *constant_string_class_name;
 309
 310
 311 /* C++ language option variables.  */
 312
 313
 314 /* Nonzero means don't recognize any extension keywords.  */
 315
 316 int flag_no_gnu_keywords;
 317
 318 /* Nonzero means do emit exported implementations of functions even if
 319    they can be inlined.  */
 320
 321 int flag_implement_inlines = 1;
 322
 323 /* Nonzero means that implicit instantiations will be emitted if needed.  */
 324
 325 int flag_implicit_templates = 1;
 326
 327 /* Nonzero means that implicit instantiations of inline templates will be
 328    emitted if needed, even if instantiations of non-inline templates
 329    aren't.  */
 330
 331 int flag_implicit_inline_templates = 1;
 332
 333 /* Nonzero means generate separate instantiation control files and
 334    juggle them at link time.  */
 335
 336 int flag_use_repository;
 337
 338 /* Nonzero if we want to issue diagnostics that the standard says are not
 339    required.  */
 340
 341 int flag_optional_diags = 1;
 342
 343 /* Nonzero means we should attempt to elide constructors when possible.  */
 344
 345 int flag_elide_constructors = 1;
 346
 347 /* Nonzero means that member functions defined in class scope are
 348    inline by default.  */
 349
 350 int flag_default_inline = 1;
 351
 352 /* Controls whether compiler generates 'type descriptor' that give
 353    run-time type information.  */
 354
 355 int flag_rtti = 1;
 356
 357 /* Nonzero if we want to conserve space in the .o files.  We do this
 358    by putting uninitialized data and runtime initialized data into
 359    .common instead of .data at the expense of not flagging multiple
 360    definitions.  */
 361
 362 int flag_conserve_space;
 363
 364 /* Nonzero if we want to obey access control semantics.  */
 365
 366 int flag_access_control = 1;
 367
 368 /* Nonzero if we want to check the return value of new and avoid calling
 369    constructors if it is a null pointer.  */
 370
 371 int flag_check_new;
 372
 373 /* The C++ dialect being used. C++98 is the default.  */
 374
 375 enum cxx_dialect cxx_dialect = cxx98;
 376
 377 /* Nonzero if we want the new ISO rules for pushing a new scope for `for'
 378    initialization variables.
 379    0: Old rules, set by -fno-for-scope.
 380    2: New ISO rules, set by -ffor-scope.
 381    1: Try to implement new ISO rules, but with backup compatibility
 382    (and warnings).  This is the default, for now.  */
 383
 384 int flag_new_for_scope = 1;
 385
 386 /* Nonzero if we want to emit defined symbols with common-like linkage as
 387    weak symbols where possible, in order to conform to C++ semantics.
 388    Otherwise, emit them as local symbols.  */
 389
 390 int flag_weak = 1;
 391
 392 /* 0 means we want the preprocessor to not emit line directives for
 393    the current working directory.  1 means we want it to do it.  -1
 394    means we should decide depending on whether debugging information
 395    is being emitted or not.  */
 396
 397 int flag_working_directory = -1;
 398
 399 /* Nonzero to use __cxa_atexit, rather than atexit, to register
 400    destructors for local statics and global objects.  '2' means it has been
 401    set nonzero as a default, not by a command-line flag.  */
 402
 403 int flag_use_cxa_atexit = DEFAULT_USE_CXA_ATEXIT;
 404
 405 /* Nonzero to use __cxa_get_exception_ptr in C++ exception-handling
 406    code.  '2' means it has not been set explicitly on the command line.  */
 407
 408 int flag_use_cxa_get_exception_ptr = 2;
 409
 410 /* Nonzero means to implement standard semantics for exception
 411    specifications, calling unexpected if an exception is thrown that
 412    doesn't match the specification.  Zero means to treat them as
 413    assertions and optimize accordingly, but not check them.  */
 414
 415 int flag_enforce_eh_specs = 1;
 416
 417 /* Nonzero means to generate thread-safe code for initializing local
 418    statics.  */
 419
 420 int flag_threadsafe_statics = 1;
 421
 422 /* Nonzero if we want to pretty-print template specializations as the
 423    template signature followed by the arguments.  */
 424
 425 int flag_pretty_templates = 1;
 426
 427 /* Nonzero means warn about implicit declarations.  */
 428
 429 int warn_implicit = 1;
 430
 431 /* Maximum template instantiation depth.  This limit exists to limit the
 432    time it takes to notice infinite template instantiations; the default
 433    value of 1024 is likely to be in the next C++ standard.  */
 434
 435 int max_tinst_depth = 1024;
 436
 437
 438
 439 /* The elements of `ridpointers' are identifier nodes for the reserved
 440    type names and storage classes.  It is indexed by a RID_... value.  */
 441 tree *ridpointers;
 442
 443 tree (*make_fname_decl) (location_t, tree, int);
 444
 445 /* Nonzero means don't warn about problems that occur when the code is
 446    executed.  */
 447 int c_inhibit_evaluation_warnings;
 448
 449 /* Whether lexing has been completed, so subsequent preprocessor
 450    errors should use the compiler's input_location.  */
 451 bool done_lexing = false;
 452
 453 /* Information about how a function name is generated.  */
 454 struct fname_var_t
 455 {
 456   tree *const decl;     /* pointer to the VAR_DECL.  */
 457   const unsigned rid;   /* RID number for the identifier.  */
 458   const int pretty;     /* How pretty is it? */
 459 };
 460
 461 /* The three ways of getting then name of the current function.  */
 462
 463 const struct fname_var_t fname_vars[] =
 464 {
 465   /* C99 compliant __func__, must be first.  */
 466   {&c99_function_name_decl_node, RID_C99_FUNCTION_NAME, 0},
 467   /* GCC __FUNCTION__ compliant.  */
 468   {&function_name_decl_node, RID_FUNCTION_NAME, 0},
 469   /* GCC __PRETTY_FUNCTION__ compliant.  */
 470   {&pretty_function_name_decl_node, RID_PRETTY_FUNCTION_NAME, 1},
 471   {NULL, 0, 0},
 472 };
 473
 474 static tree c_fully_fold_internal (tree expr, bool, bool *, bool *);
 475 static tree check_case_value (tree);
 476 static bool check_case_bounds (tree, tree, tree *, tree *);
 477
 478 static tree handle_packed_attribute (tree *, tree, tree, int, bool *);
 479 static tree handle_nocommon_attribute (tree *, tree, tree, int, bool *);
 480 static tree handle_common_attribute (tree *, tree, tree, int, bool *);
 481 static tree handle_noreturn_attribute (tree *, tree, tree, int, bool *);
 482 static tree handle_hot_attribute (tree *, tree, tree, int, bool *);
 483 static tree handle_cold_attribute (tree *, tree, tree, int, bool *);
 484 static tree handle_noinline_attribute (tree *, tree, tree, int, bool *);
 485 static tree handle_noclone_attribute (tree *, tree, tree, int, bool *);
 486 static tree handle_always_inline_attribute (tree *, tree, tree, int,
 487                                             bool *);
 488 static tree handle_gnu_inline_attribute (tree *, tree, tree, int, bool *);
 489 static tree handle_artificial_attribute (tree *, tree, tree, int, bool *);
 490 static tree handle_flatten_attribute (tree *, tree, tree, int, bool *);
 491 static tree handle_error_attribute (tree *, tree, tree, int, bool *);
 492 static tree handle_used_attribute (tree *, tree, tree, int, bool *);
 493 static tree handle_unused_attribute (tree *, tree, tree, int, bool *);
 494 static tree handle_externally_visible_attribute (tree *, tree, tree, int,
 495                                                  bool *);
 496 static tree handle_const_attribute (tree *, tree, tree, int, bool *);
 497 static tree handle_transparent_union_attribute (tree *, tree, tree,
 498                                                 int, bool *);
 499 static tree handle_constructor_attribute (tree *, tree, tree, int, bool *);
 500 static tree handle_destructor_attribute (tree *, tree, tree, int, bool *);
 501 static tree handle_mode_attribute (tree *, tree, tree, int, bool *);
 502 static tree handle_section_attribute (tree *, tree, tree, int, bool *);
 503 static tree handle_aligned_attribute (tree *, tree, tree, int, bool *);
 504 static tree handle_weak_attribute (tree *, tree, tree, int, bool *) ;
 505 static tree handle_alias_attribute (tree *, tree, tree, int, bool *);
 506 static tree handle_weakref_attribute (tree *, tree, tree, int, bool *) ;
 507 static tree handle_visibility_attribute (tree *, tree, tree, int,
 508                                          bool *);
 509 static tree handle_tls_model_attribute (tree *, tree, tree, int,
 510                                         bool *);
 511 static tree handle_no_instrument_function_attribute (tree *, tree,
 512                                                      tree, int, bool *);
 513 static tree handle_malloc_attribute (tree *, tree, tree, int, bool *);
 514 static tree handle_returns_twice_attribute (tree *, tree, tree, int, bool *);
 515 static tree handle_no_limit_stack_attribute (tree *, tree, tree, int,
 516                                              bool *);
 517 static tree handle_pure_attribute (tree *, tree, tree, int, bool *);
 518 static tree handle_novops_attribute (tree *, tree, tree, int, bool *);
 519 static tree handle_deprecated_attribute (tree *, tree, tree, int,
 520                                          bool *);
 521 static tree handle_vector_size_attribute (tree *, tree, tree, int,
 522                                           bool *);
 523 static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *);
 524 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
 525 static tree handle_cleanup_attribute (tree *, tree, tree, int, bool *);
 526 static tree handle_warn_unused_result_attribute (tree *, tree, tree, int,
 527                                                  bool *);
 528 static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *);
 529 static tree handle_type_generic_attribute (tree *, tree, tree, int, bool *);
 530 static tree handle_alloc_size_attribute (tree *, tree, tree, int, bool *);
 531 static tree handle_target_attribute (tree *, tree, tree, int, bool *);
 532 static tree handle_optimize_attribute (tree *, tree, tree, int, bool *);
 533 static tree handle_ifunc_attribute (tree *, tree, tree, int, bool *);
 534
 535 static void check_function_nonnull (tree, int, tree *);
 536 static void check_nonnull_arg (void *, tree, unsigned HOST_WIDE_INT);
 537 static bool nonnull_check_p (tree, unsigned HOST_WIDE_INT);
 538 static bool get_nonnull_operand (tree, unsigned HOST_WIDE_INT *);
 539 static int resort_field_decl_cmp (const void *, const void *);
 540
 541 /* Reserved words.  The third field is a mask: keywords are disabled
 542    if they match the mask.
 543
 544    Masks for languages:
 545    C --std=c89: D_C99 | D_CXXONLY | D_OBJC | D_CXX_OBJC
 546    C --std=c99: D_CXXONLY | D_OBJC
 547    ObjC is like C except that D_OBJC and D_CXX_OBJC are not set
 548    C++ --std=c98: D_CONLY | D_CXXOX | D_OBJC
 549    C++ --std=c0x: D_CONLY | D_OBJC
 550    ObjC++ is like C++ except that D_OBJC is not set
 551
 552    If -fno-asm is used, D_ASM is added to the mask.  If
 553    -fno-gnu-keywords is used, D_EXT is added.  If -fno-asm and C in
 554    C89 mode, D_EXT89 is added for both -fno-asm and -fno-gnu-keywords.
 555    In C with -Wc++-compat, we warn if D_CXXWARN is set.  */
 556
 557 const struct c_common_resword c_common_reswords[] =
 558 {
 559   { "_Bool",            RID_BOOL,      D_CONLY },
 560   { "_Complex",         RID_COMPLEX,    0 },
 561   { "_Imaginary",       RID_IMAGINARY, D_CONLY },
 562   { "_Decimal32",       RID_DFLOAT32,  D_CONLY | D_EXT },
 563   { "_Decimal64",       RID_DFLOAT64,  D_CONLY | D_EXT },
 564   { "_Decimal128",      RID_DFLOAT128, D_CONLY | D_EXT },
 565   { "_Fract",           RID_FRACT,     D_CONLY | D_EXT },
 566   { "_Accum",           RID_ACCUM,     D_CONLY | D_EXT },
 567   { "_Sat",             RID_SAT,       D_CONLY | D_EXT },
 568   { "__FUNCTION__",     RID_FUNCTION_NAME, 0 },
 569   { "__PRETTY_FUNCTION__", RID_PRETTY_FUNCTION_NAME, 0 },
 570   { "__alignof",        RID_ALIGNOF,    0 },
 571   { "__alignof__",      RID_ALIGNOF,    0 },
 572   { "__asm",            RID_ASM,        0 },
 573   { "__asm__",          RID_ASM,        0 },
 574   { "__attribute",      RID_ATTRIBUTE,  0 },
 575   { "__attribute__",    RID_ATTRIBUTE,  0 },
 576   { "__builtin_choose_expr", RID_CHOOSE_EXPR, D_CONLY },
 577   { "__builtin_offsetof", RID_OFFSETOF, 0 },
 578   { "__builtin_types_compatible_p", RID_TYPES_COMPATIBLE_P, D_CONLY },
 579   { "__builtin_va_arg", RID_VA_ARG,     0 },
 580   { "__complex",        RID_COMPLEX,    0 },
 581   { "__complex__",      RID_COMPLEX,    0 },
 582   { "__const",          RID_CONST,      0 },
 583   { "__const__",        RID_CONST,      0 },
 584   { "__decltype",       RID_DECLTYPE,   D_CXXONLY },
 585   { "__extension__",    RID_EXTENSION,  0 },
 586   { "__func__",         RID_C99_FUNCTION_NAME, 0 },
 587   { "__has_nothrow_assign", RID_HAS_NOTHROW_ASSIGN, D_CXXONLY },
 588   { "__has_nothrow_constructor", RID_HAS_NOTHROW_CONSTRUCTOR, D_CXXONLY },
 589   { "__has_nothrow_copy", RID_HAS_NOTHROW_COPY, D_CXXONLY },
 590   { "__has_trivial_assign", RID_HAS_TRIVIAL_ASSIGN, D_CXXONLY },
 591   { "__has_trivial_constructor", RID_HAS_TRIVIAL_CONSTRUCTOR, D_CXXONLY },
 592   { "__has_trivial_copy", RID_HAS_TRIVIAL_COPY, D_CXXONLY },
 593   { "__has_trivial_destructor", RID_HAS_TRIVIAL_DESTRUCTOR, D_CXXONLY },
 594   { "__has_virtual_destructor", RID_HAS_VIRTUAL_DESTRUCTOR, D_CXXONLY },
 595   { "__is_abstract",    RID_IS_ABSTRACT, D_CXXONLY },
 596   { "__is_base_of",     RID_IS_BASE_OF, D_CXXONLY },
 597   { "__is_class",       RID_IS_CLASS,   D_CXXONLY },
 598   { "__is_convertible_to", RID_IS_CONVERTIBLE_TO, D_CXXONLY },
 599   { "__is_empty",       RID_IS_EMPTY,   D_CXXONLY },
 600   { "__is_enum",        RID_IS_ENUM,    D_CXXONLY },
 601   { "__is_pod",         RID_IS_POD,     D_CXXONLY },
 602   { "__is_polymorphic", RID_IS_POLYMORPHIC, D_CXXONLY },
 603   { "__is_standard_layout", RID_IS_STD_LAYOUT, D_CXXONLY },
 604   { "__is_trivial",     RID_IS_TRIVIAL, D_CXXONLY },
 605   { "__is_union",       RID_IS_UNION,   D_CXXONLY },
 606   { "__imag",           RID_IMAGPART,   0 },
 607   { "__imag__",         RID_IMAGPART,   0 },
 608   { "__inline",         RID_INLINE,     0 },
 609   { "__inline__",       RID_INLINE,     0 },
 610   { "__label__",        RID_LABEL,      0 },
 611   { "__null",           RID_NULL,       0 },
 612   { "__real",           RID_REALPART,   0 },
 613   { "__real__",         RID_REALPART,   0 },
 614   { "__restrict",       RID_RESTRICT,   0 },
 615   { "__restrict__",     RID_RESTRICT,   0 },
 616   { "__signed",         RID_SIGNED,     0 },
 617   { "__signed__",       RID_SIGNED,     0 },
 618   { "__thread",         RID_THREAD,     0 },
 619   { "__typeof",         RID_TYPEOF,     0 },
 620   { "__typeof__",       RID_TYPEOF,     0 },
 621   { "__volatile",       RID_VOLATILE,   0 },
 622   { "__volatile__",     RID_VOLATILE,   0 },
 623   { "alignof",          RID_ALIGNOF,    D_CXXONLY | D_CXX0X | D_CXXWARN },
 624   { "asm",              RID_ASM,        D_ASM },
 625   { "auto",             RID_AUTO,       0 },
 626   { "bool",             RID_BOOL,       D_CXXONLY | D_CXXWARN },
 627   { "break",            RID_BREAK,      0 },
 628   { "case",             RID_CASE,       0 },
 629   { "catch",            RID_CATCH,      D_CXX_OBJC | D_CXXWARN },
 630   { "char",             RID_CHAR,       0 },
 631   { "char16_t",         RID_CHAR16,     D_CXXONLY | D_CXX0X | D_CXXWARN },
 632   { "char32_t",         RID_CHAR32,     D_CXXONLY | D_CXX0X | D_CXXWARN },
 633   { "class",            RID_CLASS,      D_CXX_OBJC | D_CXXWARN },
 634   { "const",            RID_CONST,      0 },
 635   { "constexpr",        RID_CONSTEXPR,  D_CXXONLY | D_CXX0X | D_CXXWARN },
 636   { "const_cast",       RID_CONSTCAST,  D_CXXONLY | D_CXXWARN },
 637   { "continue",         RID_CONTINUE,   0 },
 638   { "decltype",         RID_DECLTYPE,   D_CXXONLY | D_CXX0X | D_CXXWARN },
 639   { "default",          RID_DEFAULT,    0 },
 640   { "delete",           RID_DELETE,     D_CXXONLY | D_CXXWARN },
 641   { "do",               RID_DO,         0 },
 642   { "double",           RID_DOUBLE,     0 },
 643   { "dynamic_cast",     RID_DYNCAST,    D_CXXONLY | D_CXXWARN },
 644   { "else",             RID_ELSE,       0 },
 645   { "enum",             RID_ENUM,       0 },
 646   { "explicit",         RID_EXPLICIT,   D_CXXONLY | D_CXXWARN },
 647   { "export",           RID_EXPORT,     D_CXXONLY | D_CXXWARN },
 648   { "extern",           RID_EXTERN,     0 },
 649   { "false",            RID_FALSE,      D_CXXONLY | D_CXXWARN },
 650   { "float",            RID_FLOAT,      0 },
 651   { "for",              RID_FOR,        0 },
 652   { "friend",           RID_FRIEND,     D_CXXONLY | D_CXXWARN },
 653   { "goto",             RID_GOTO,       0 },
 654   { "if",               RID_IF,         0 },
 655   { "inline",           RID_INLINE,     D_EXT89 },
 656   { "int",              RID_INT,        0 },
 657   { "long",             RID_LONG,       0 },
 658   { "mutable",          RID_MUTABLE,    D_CXXONLY | D_CXXWARN },
 659   { "namespace",        RID_NAMESPACE,  D_CXXONLY | D_CXXWARN },
 660   { "new",              RID_NEW,        D_CXXONLY | D_CXXWARN },
 661   { "operator",         RID_OPERATOR,   D_CXXONLY | D_CXXWARN },
 662   { "private",          RID_PRIVATE,    D_CXX_OBJC | D_CXXWARN },
 663   { "protected",        RID_PROTECTED,  D_CXX_OBJC | D_CXXWARN },
 664   { "public",           RID_PUBLIC,     D_CXX_OBJC | D_CXXWARN },
 665   { "register",         RID_REGISTER,   0 },
 666   { "reinterpret_cast", RID_REINTCAST,  D_CXXONLY | D_CXXWARN },
 667   { "restrict",         RID_RESTRICT,   D_CONLY | D_C99 },
 668   { "return",           RID_RETURN,     0 },
 669   { "short",            RID_SHORT,      0 },
 670   { "signed",           RID_SIGNED,     0 },
 671   { "sizeof",           RID_SIZEOF,     0 },
 672   { "static",           RID_STATIC,     0 },
 673   { "static_assert",    RID_STATIC_ASSERT, D_CXXONLY | D_CXX0X | D_CXXWARN },
 674   { "static_cast",      RID_STATCAST,   D_CXXONLY | D_CXXWARN },
 675   { "struct",           RID_STRUCT,     0 },
 676   { "switch",           RID_SWITCH,     0 },
 677   { "template",         RID_TEMPLATE,   D_CXXONLY | D_CXXWARN },
 678   { "this",             RID_THIS,       D_CXXONLY | D_CXXWARN },
 679   { "throw",            RID_THROW,      D_CXX_OBJC | D_CXXWARN },
 680   { "true",             RID_TRUE,       D_CXXONLY | D_CXXWARN },
 681   { "try",              RID_TRY,        D_CXX_OBJC | D_CXXWARN },
 682   { "typedef",          RID_TYPEDEF,    0 },
 683   { "typename",         RID_TYPENAME,   D_CXXONLY | D_CXXWARN },
 684   { "typeid",           RID_TYPEID,     D_CXXONLY | D_CXXWARN },
 685   { "typeof",           RID_TYPEOF,     D_ASM | D_EXT },
 686   { "union",            RID_UNION,      0 },
 687   { "unsigned",         RID_UNSIGNED,   0 },
 688   { "using",            RID_USING,      D_CXXONLY | D_CXXWARN },
 689   { "virtual",          RID_VIRTUAL,    D_CXXONLY | D_CXXWARN },
 690   { "void",             RID_VOID,       0 },
 691   { "volatile",         RID_VOLATILE,   0 },
 692   { "wchar_t",          RID_WCHAR,      D_CXXONLY },
 693   { "while",            RID_WHILE,      0 },
 694   /* These Objective-C keywords are recognized only immediately after
 695      an '@'.  */
 696   { "compatibility_alias", RID_AT_ALIAS,        D_OBJC },
 697   { "defs",             RID_AT_DEFS,            D_OBJC },
 698   { "encode",           RID_AT_ENCODE,          D_OBJC },
 699   { "end",              RID_AT_END,             D_OBJC },
 700   { "implementation",   RID_AT_IMPLEMENTATION,  D_OBJC },
 701   { "interface",        RID_AT_INTERFACE,       D_OBJC },
 702   { "protocol",         RID_AT_PROTOCOL,        D_OBJC },
 703   { "selector",         RID_AT_SELECTOR,        D_OBJC },
 704   { "finally",          RID_AT_FINALLY,         D_OBJC },
 705   { "synchronized",     RID_AT_SYNCHRONIZED,    D_OBJC },
 706   /* These are recognized only in protocol-qualifier context
 707      (see above) */
 708   { "bycopy",           RID_BYCOPY,             D_OBJC },
 709   { "byref",            RID_BYREF,              D_OBJC },
 710   { "in",               RID_IN,                 D_OBJC },
 711   { "inout",            RID_INOUT,              D_OBJC },
 712   { "oneway",           RID_ONEWAY,             D_OBJC },
 713   { "out",              RID_OUT,                D_OBJC },
 714
 715 #ifdef TARGET_ADDR_SPACE_KEYWORDS
 716   /* Any address space keywords recognized by the target.  */
 717   TARGET_ADDR_SPACE_KEYWORDS,
 718 #endif
 719 };
 720
 721 const unsigned int num_c_common_reswords =
 722   sizeof c_common_reswords / sizeof (struct c_common_resword);
 723
 724 /* Table of machine-independent attributes common to all C-like languages.  */
 725 const struct attribute_spec c_common_attribute_table[] =
 726 {
 727   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 728   { "packed",                 0, 0, false, false, false,
 729                               handle_packed_attribute },
 730   { "nocommon",               0, 0, true,  false, false,
 731                               handle_nocommon_attribute },
 732   { "common",                 0, 0, true,  false, false,
 733                               handle_common_attribute },
 734   /* FIXME: logically, noreturn attributes should be listed as
 735      "false, true, true" and apply to function types.  But implementing this
 736      would require all the places in the compiler that use TREE_THIS_VOLATILE
 737      on a decl to identify non-returning functions to be located and fixed
 738      to check the function type instead.  */
 739   { "noreturn",               0, 0, true,  false, false,
 740                               handle_noreturn_attribute },
 741   { "volatile",               0, 0, true,  false, false,
 742                               handle_noreturn_attribute },
 743   { "noinline",               0, 0, true,  false, false,
 744                               handle_noinline_attribute },
 745   { "noclone",                0, 0, true,  false, false,
 746                               handle_noclone_attribute },
 747   { "always_inline",          0, 0, true,  false, false,
 748                               handle_always_inline_attribute },
 749   { "gnu_inline",             0, 0, true,  false, false,
 750                               handle_gnu_inline_attribute },
 751   { "artificial",             0, 0, true,  false, false,
 752                               handle_artificial_attribute },
 753   { "flatten",                0, 0, true,  false, false,
 754                               handle_flatten_attribute },
 755   { "used",                   0, 0, true,  false, false,
 756                               handle_used_attribute },
 757   { "unused",                 0, 0, false, false, false,
 758                               handle_unused_attribute },
 759   { "externally_visible",     0, 0, true,  false, false,
 760                               handle_externally_visible_attribute },
 761   /* The same comments as for noreturn attributes apply to const ones.  */
 762   { "const",                  0, 0, true,  false, false,
 763                               handle_const_attribute },
 764   { "transparent_union",      0, 0, false, false, false,
 765                               handle_transparent_union_attribute },
 766   { "constructor",            0, 1, true,  false, false,
 767                               handle_constructor_attribute },
 768   { "destructor",             0, 1, true,  false, false,
 769                               handle_destructor_attribute },
 770   { "mode",                   1, 1, false,  true, false,
 771                               handle_mode_attribute },
 772   { "section",                1, 1, true,  false, false,
 773                               handle_section_attribute },
 774   { "aligned",                0, 1, false, false, false,
 775                               handle_aligned_attribute },
 776   { "weak",                   0, 0, true,  false, false,
 777                               handle_weak_attribute },
 778   { "alias",                  1, 1, true,  false, false,
 779                               handle_alias_attribute },
 780   { "weakref",                0, 1, true,  false, false,
 781                               handle_weakref_attribute },
 782   { "no_instrument_function", 0, 0, true,  false, false,
 783                               handle_no_instrument_function_attribute },
 784   { "malloc",                 0, 0, true,  false, false,
 785                               handle_malloc_attribute },
 786   { "returns_twice",          0, 0, true,  false, false,
 787                               handle_returns_twice_attribute },
 788   { "no_stack_limit",         0, 0, true,  false, false,
 789                               handle_no_limit_stack_attribute },
 790   { "pure",                   0, 0, true,  false, false,
 791                               handle_pure_attribute },
 792   /* For internal use (marking of builtins) only.  The name contains space
 793      to prevent its usage in source code.  */
 794   { "no vops",                0, 0, true,  false, false,
 795                               handle_novops_attribute },
 796   { "deprecated",             0, 1, false, false, false,
 797                               handle_deprecated_attribute },
 798   { "vector_size",            1, 1, false, true, false,
 799                               handle_vector_size_attribute },
 800   { "visibility",             1, 1, false, false, false,
 801                               handle_visibility_attribute },
 802   { "tls_model",              1, 1, true,  false, false,
 803                               handle_tls_model_attribute },
 804   { "nonnull",                0, -1, false, true, true,
 805                               handle_nonnull_attribute },
 806   { "nothrow",                0, 0, true,  false, false,
 807                               handle_nothrow_attribute },
 808   { "may_alias",              0, 0, false, true, false, NULL },
 809   { "cleanup",                1, 1, true, false, false,
 810                               handle_cleanup_attribute },
 811   { "warn_unused_result",     0, 0, false, true, true,
 812                               handle_warn_unused_result_attribute },
 813   { "sentinel",               0, 1, false, true, true,
 814                               handle_sentinel_attribute },
 815   /* For internal use (marking of builtins) only.  The name contains space
 816      to prevent its usage in source code.  */
 817   { "type generic",           0, 0, false, true, true,
 818                               handle_type_generic_attribute },
 819   { "alloc_size",             1, 2, false, true, true,
 820                               handle_alloc_size_attribute },
 821   { "cold",                   0, 0, true,  false, false,
 822                               handle_cold_attribute },
 823   { "hot",                    0, 0, true,  false, false,
 824                               handle_hot_attribute },
 825   { "warning",                1, 1, true,  false, false,
 826                               handle_error_attribute },
 827   { "error",                  1, 1, true,  false, false,
 828                               handle_error_attribute },
 829   { "target",                 1, -1, true, false, false,
 830                               handle_target_attribute },
 831   { "optimize",               1, -1, true, false, false,
 832                               handle_optimize_attribute },
 833   { "ifunc",                  0, 0, true,  false, false,
 834                               handle_ifunc_attribute },
 835   { NULL,                     0, 0, false, false, false, NULL }
 836 };
 837
 838 /* Give the specifications for the format attributes, used by C and all
 839    descendants.  */
 840
 841 const struct attribute_spec c_common_format_attribute_table[] =
 842 {
 843   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 844   { "format",                 3, 3, false, true,  true,
 845                               handle_format_attribute },
 846   { "format_arg",             1, 1, false, true,  true,
 847                               handle_format_arg_attribute },
 848   { NULL,                     0, 0, false, false, false, NULL }
 849 };
 850
 851 /* Return identifier for address space AS.  */
 852 const char *
 853 c_addr_space_name (addr_space_t as)
 854 {
 855   unsigned int i;
 856
 857   for (i = 0; i < num_c_common_reswords; i++)
 858     if (c_common_reswords[i].rid == RID_FIRST_ADDR_SPACE + as)
 859       return c_common_reswords[i].word;
 860
 861   gcc_unreachable ();
 862 }
 863
 864 /* Push current bindings for the function name VAR_DECLS.  */
 865
 866 void
 867 start_fname_decls (void)
 868 {
 869   unsigned ix;
 870   tree saved = NULL_TREE;
 871
 872   for (ix = 0; fname_vars[ix].decl; ix++)
 873     {
 874       tree decl = *fname_vars[ix].decl;
 875
 876       if (decl)
 877         {
 878           saved = tree_cons (decl, build_int_cst (NULL_TREE, ix), saved);
 879           *fname_vars[ix].decl = NULL_TREE;
 880         }
 881     }
 882   if (saved || saved_function_name_decls)
 883     /* Normally they'll have been NULL, so only push if we've got a
 884        stack, or they are non-NULL.  */
 885     saved_function_name_decls = tree_cons (saved, NULL_TREE,
 886                                            saved_function_name_decls);
 887 }
 888
 889 /* Finish up the current bindings, adding them into the current function's
 890    statement tree.  This must be done _before_ finish_stmt_tree is called.
 891    If there is no current function, we must be at file scope and no statements
 892    are involved. Pop the previous bindings.  */
 893
 894 void
 895 finish_fname_decls (void)
 896 {
 897   unsigned ix;
 898   tree stmts = NULL_TREE;
 899   tree stack = saved_function_name_decls;
 900
 901   for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack))
 902     append_to_statement_list (TREE_VALUE (stack), &stmts);
 903
 904   if (stmts)
 905     {
 906       tree *bodyp = &DECL_SAVED_TREE (current_function_decl);
 907
 908       if (TREE_CODE (*bodyp) == BIND_EXPR)
 909         bodyp = &BIND_EXPR_BODY (*bodyp);
 910
 911       append_to_statement_list_force (*bodyp, &stmts);
 912       *bodyp = stmts;
 913     }
 914
 915   for (ix = 0; fname_vars[ix].decl; ix++)
 916     *fname_vars[ix].decl = NULL_TREE;
 917
 918   if (stack)
 919     {
 920       /* We had saved values, restore them.  */
 921       tree saved;
 922
 923       for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved))
 924         {
 925           tree decl = TREE_PURPOSE (saved);
 926           unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved));
 927
 928           *fname_vars[ix].decl = decl;
 929         }
 930       stack = TREE_CHAIN (stack);
 931     }
 932   saved_function_name_decls = stack;
 933 }
 934
 935 /* Return the text name of the current function, suitably prettified
 936    by PRETTY_P.  Return string must be freed by caller.  */
 937
 938 const char *
 939 fname_as_string (int pretty_p)
 940 {
 941   const char *name = "top level";
 942   char *namep;
 943   int vrb = 2, len;
 944   cpp_string cstr = { 0, 0 }, strname;
 945
 946   if (!pretty_p)
 947     {
 948       name = "";
 949       vrb = 0;
 950     }
 951
 952   if (current_function_decl)
 953     name = lang_hooks.decl_printable_name (current_function_decl, vrb);
 954
 955   len = strlen (name) + 3; /* Two for '"'s.  One for NULL.  */
 956
 957   namep = XNEWVEC (char, len);
 958   snprintf (namep, len, "\"%s\"", name);
 959   strname.text = (unsigned char *) namep;
 960   strname.len = len - 1;
 961
 962   if (cpp_interpret_string (parse_in, &strname, 1, &cstr, CPP_STRING))
 963     {
 964       XDELETEVEC (namep);
 965       return (const char *) cstr.text;
 966     }
 967
 968   return namep;
 969 }
 970
 971 /* Return the VAR_DECL for a const char array naming the current
 972    function. If the VAR_DECL has not yet been created, create it
 973    now. RID indicates how it should be formatted and IDENTIFIER_NODE
 974    ID is its name (unfortunately C and C++ hold the RID values of
 975    keywords in different places, so we can't derive RID from ID in
 976    this language independent code. LOC is the location of the
 977    function.  */
 978
 979 tree
 980 fname_decl (location_t loc, unsigned int rid, tree id)
 981 {
 982   unsigned ix;
 983   tree decl = NULL_TREE;
 984
 985   for (ix = 0; fname_vars[ix].decl; ix++)
 986     if (fname_vars[ix].rid == rid)
 987       break;
 988
 989   decl = *fname_vars[ix].decl;
 990   if (!decl)
 991     {
 992       /* If a tree is built here, it would normally have the lineno of
 993          the current statement.  Later this tree will be moved to the
 994          beginning of the function and this line number will be wrong.
 995          To avoid this problem set the lineno to 0 here; that prevents
 996          it from appearing in the RTL.  */
 997       tree stmts;
 998       location_t saved_location = input_location;
 999       input_location = UNKNOWN_LOCATION;
1000
1001       stmts = push_stmt_list ();
1002       decl = (*make_fname_decl) (loc, id, fname_vars[ix].pretty);
1003       stmts = pop_stmt_list (stmts);
1004       if (!IS_EMPTY_STMT (stmts))
1005         saved_function_name_decls
1006           = tree_cons (decl, stmts, saved_function_name_decls);
1007       *fname_vars[ix].decl = decl;
1008       input_location = saved_location;
1009     }
1010   if (!ix && !current_function_decl)
1011     pedwarn (loc, 0, "%qD is not defined outside of function scope", decl);
1012
1013   return decl;
1014 }
1015
1016 /* Given a STRING_CST, give it a suitable array-of-chars data type.  */
1017
1018 tree
1019 fix_string_type (tree value)
1020 {
1021   int length = TREE_STRING_LENGTH (value);
1022   int nchars;
1023   tree e_type, i_type, a_type;
1024
1025   /* Compute the number of elements, for the array type.  */
1026   if (TREE_TYPE (value) == char_array_type_node || !TREE_TYPE (value))
1027     {
1028       nchars = length;
1029       e_type = char_type_node;
1030     }
1031   else if (TREE_TYPE (value) == char16_array_type_node)
1032     {
1033       nchars = length / (TYPE_PRECISION (char16_type_node) / BITS_PER_UNIT);
1034       e_type = char16_type_node;
1035     }
1036   else if (TREE_TYPE (value) == char32_array_type_node)
1037     {
1038       nchars = length / (TYPE_PRECISION (char32_type_node) / BITS_PER_UNIT);
1039       e_type = char32_type_node;
1040     }
1041   else
1042     {
1043       nchars = length / (TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT);
1044       e_type = wchar_type_node;
1045     }
1046
1047   /* C89 2.2.4.1, C99 5.2.4.1 (Translation limits).  The analogous
1048      limit in C++98 Annex B is very large (65536) and is not normative,
1049      so we do not diagnose it (warn_overlength_strings is forced off
1050      in c_common_post_options).  */
1051   if (warn_overlength_strings)
1052     {
1053       const int nchars_max = flag_isoc99 ? 4095 : 509;
1054       const int relevant_std = flag_isoc99 ? 99 : 90;
1055       if (nchars - 1 > nchars_max)
1056         /* Translators: The %d after 'ISO C' will be 90 or 99.  Do not
1057            separate the %d from the 'C'.  'ISO' should not be
1058            translated, but it may be moved after 'C%d' in languages
1059            where modifiers follow nouns.  */
1060         pedwarn (input_location, OPT_Woverlength_strings,
1061                  "string length %qd is greater than the length %qd "
1062                  "ISO C%d compilers are required to support",
1063                  nchars - 1, nchars_max, relevant_std);
1064     }
1065
1066   /* Create the array type for the string constant.  The ISO C++
1067      standard says that a string literal has type `const char[N]' or
1068      `const wchar_t[N]'.  We use the same logic when invoked as a C
1069      front-end with -Wwrite-strings.
1070      ??? We should change the type of an expression depending on the
1071      state of a warning flag.  We should just be warning -- see how
1072      this is handled in the C++ front-end for the deprecated implicit
1073      conversion from string literals to `char*' or `wchar_t*'.
1074
1075      The C++ front end relies on TYPE_MAIN_VARIANT of a cv-qualified
1076      array type being the unqualified version of that type.
1077      Therefore, if we are constructing an array of const char, we must
1078      construct the matching unqualified array type first.  The C front
1079      end does not require this, but it does no harm, so we do it
1080      unconditionally.  */
1081   i_type = build_index_type (build_int_cst (NULL_TREE, nchars - 1));
1082   a_type = build_array_type (e_type, i_type);
1083   if (c_dialect_cxx() || warn_write_strings)
1084     a_type = c_build_qualified_type (a_type, TYPE_QUAL_CONST);
1085
1086   TREE_TYPE (value) = a_type;
1087   TREE_CONSTANT (value) = 1;
1088   TREE_READONLY (value) = 1;
1089   TREE_STATIC (value) = 1;
1090   return value;
1091 }
1092 \f
1093 /* Fully fold EXPR, an expression that was not folded (beyond integer
1094    constant expressions and null pointer constants) when being built
1095    up.  If IN_INIT, this is in a static initializer and certain
1096    changes are made to the folding done.  Clear *MAYBE_CONST if
1097    MAYBE_CONST is not NULL and EXPR is definitely not a constant
1098    expression because it contains an evaluated operator (in C99) or an
1099    operator outside of sizeof returning an integer constant (in C90)
1100    not permitted in constant expressions, or because it contains an
1101    evaluated arithmetic overflow.  (*MAYBE_CONST should typically be
1102    set to true by callers before calling this function.)  Return the
1103    folded expression.  Function arguments have already been folded
1104    before calling this function, as have the contents of SAVE_EXPR,
1105    TARGET_EXPR, BIND_EXPR, VA_ARG_EXPR, OBJ_TYPE_REF and
1106    C_MAYBE_CONST_EXPR.  */
1107
1108 tree
1109 c_fully_fold (tree expr, bool in_init, bool *maybe_const)
1110 {
1111   tree ret;
1112   tree eptype = NULL_TREE;
1113   bool dummy = true;
1114   bool maybe_const_itself = true;
1115   location_t loc = EXPR_LOCATION (expr);
1116
1117   /* This function is not relevant to C++ because C++ folds while
1118      parsing, and may need changes to be correct for C++ when C++
1119      stops folding while parsing.  */
1120   if (c_dialect_cxx ())
1121     gcc_unreachable ();
1122
1123   if (!maybe_const)
1124     maybe_const = &dummy;
1125   if (TREE_CODE (expr) == EXCESS_PRECISION_EXPR)
1126     {
1127       eptype = TREE_TYPE (expr);
1128       expr = TREE_OPERAND (expr, 0);
1129     }
1130   ret = c_fully_fold_internal (expr, in_init, maybe_const,
1131                                &maybe_const_itself);
1132   if (eptype)
1133     ret = fold_convert_loc (loc, eptype, ret);
1134   *maybe_const &= maybe_const_itself;
1135   return ret;
1136 }
1137
1138 /* Internal helper for c_fully_fold.  EXPR and IN_INIT are as for
1139    c_fully_fold.  *MAYBE_CONST_OPERANDS is cleared because of operands
1140    not permitted, while *MAYBE_CONST_ITSELF is cleared because of
1141    arithmetic overflow (for C90, *MAYBE_CONST_OPERANDS is carried from
1142    both evaluated and unevaluated subexpressions while
1143    *MAYBE_CONST_ITSELF is carried from only evaluated
1144    subexpressions).  */
1145
1146 static tree
1147 c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands,
1148                        bool *maybe_const_itself)
1149 {
1150   tree ret = expr;
1151   enum tree_code code = TREE_CODE (expr);
1152   enum tree_code_class kind = TREE_CODE_CLASS (code);
1153   location_t loc = EXPR_LOCATION (expr);
1154   tree op0, op1, op2, op3;
1155   tree orig_op0, orig_op1, orig_op2;
1156   bool op0_const = true, op1_const = true, op2_const = true;
1157   bool op0_const_self = true, op1_const_self = true, op2_const_self = true;
1158   bool nowarning = TREE_NO_WARNING (expr);
1159   int unused_p;
1160
1161   /* This function is not relevant to C++ because C++ folds while
1162      parsing, and may need changes to be correct for C++ when C++
1163      stops folding while parsing.  */
1164   if (c_dialect_cxx ())
1165     gcc_unreachable ();
1166
1167   /* Constants, declarations, statements, errors, SAVE_EXPRs and
1168      anything else not counted as an expression cannot usefully be
1169      folded further at this point.  */
1170   if (!IS_EXPR_CODE_CLASS (kind)
1171       || kind == tcc_statement
1172       || code == SAVE_EXPR)
1173     return expr;
1174
1175   /* Operands of variable-length expressions (function calls) have
1176      already been folded, as have __builtin_* function calls, and such
1177      expressions cannot occur in constant expressions.  */
1178   if (kind == tcc_vl_exp)
1179     {
1180       *maybe_const_operands = false;
1181       ret = fold (expr);
1182       goto out;
1183     }
1184
1185   if (code == C_MAYBE_CONST_EXPR)
1186     {
1187       tree pre = C_MAYBE_CONST_EXPR_PRE (expr);
1188       tree inner = C_MAYBE_CONST_EXPR_EXPR (expr);
1189       if (C_MAYBE_CONST_EXPR_NON_CONST (expr))
1190         *maybe_const_operands = false;
1191       if (C_MAYBE_CONST_EXPR_INT_OPERANDS (expr))
1192         *maybe_const_itself = false;
1193       if (pre && !in_init)
1194         ret = build2 (COMPOUND_EXPR, TREE_TYPE (expr), pre, inner);
1195       else
1196         ret = inner;
1197       goto out;
1198     }
1199
1200   /* Assignment, increment, decrement, function call and comma
1201      operators, and statement expressions, cannot occur in constant
1202      expressions if evaluated / outside of sizeof.  (Function calls
1203      were handled above, though VA_ARG_EXPR is treated like a function
1204      call here, and statement expressions are handled through
1205      C_MAYBE_CONST_EXPR to avoid folding inside them.)  */
1206   switch (code)
1207     {
1208     case MODIFY_EXPR:
1209     case PREDECREMENT_EXPR:
1210     case PREINCREMENT_EXPR:
1211     case POSTDECREMENT_EXPR:
1212     case POSTINCREMENT_EXPR:
1213     case COMPOUND_EXPR:
1214       *maybe_const_operands = false;
1215       break;
1216
1217     case VA_ARG_EXPR:
1218     case TARGET_EXPR:
1219     case BIND_EXPR:
1220     case OBJ_TYPE_REF:
1221       *maybe_const_operands = false;
1222       ret = fold (expr);
1223       goto out;
1224
1225     default:
1226       break;
1227     }
1228
1229   /* Fold individual tree codes as appropriate.  */
1230   switch (code)
1231     {
1232     case COMPOUND_LITERAL_EXPR:
1233       /* Any non-constancy will have been marked in a containing
1234          C_MAYBE_CONST_EXPR; there is no more folding to do here.  */
1235       goto out;
1236
1237     case COMPONENT_REF:
1238       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1239       op1 = TREE_OPERAND (expr, 1);
1240       op2 = TREE_OPERAND (expr, 2);
1241       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1242                                    maybe_const_itself);
1243       STRIP_TYPE_NOPS (op0);
1244       if (op0 != orig_op0)
1245         ret = build3 (COMPONENT_REF, TREE_TYPE (expr), op0, op1, op2);
1246       if (ret != expr)
1247         {
1248           TREE_READONLY (ret) = TREE_READONLY (expr);
1249           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1250         }
1251       goto out;
1252
1253     case ARRAY_REF:
1254       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1255       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1256       op2 = TREE_OPERAND (expr, 2);
1257       op3 = TREE_OPERAND (expr, 3);
1258       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1259                                    maybe_const_itself);
1260       STRIP_TYPE_NOPS (op0);
1261       op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
1262                                    maybe_const_itself);
1263       STRIP_TYPE_NOPS (op1);
1264       op1 = decl_constant_value_for_optimization (op1);
1265       if (op0 != orig_op0 || op1 != orig_op1)
1266         ret = build4 (ARRAY_REF, TREE_TYPE (expr), op0, op1, op2, op3);
1267       if (ret != expr)
1268         {
1269           TREE_READONLY (ret) = TREE_READONLY (expr);
1270           TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (expr);
1271           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1272         }
1273       ret = fold (ret);
1274       goto out;
1275
1276     case COMPOUND_EXPR:
1277     case MODIFY_EXPR:
1278     case PREDECREMENT_EXPR:
1279     case PREINCREMENT_EXPR:
1280     case POSTDECREMENT_EXPR:
1281     case POSTINCREMENT_EXPR:
1282     case PLUS_EXPR:
1283     case MINUS_EXPR:
1284     case MULT_EXPR:
1285     case POINTER_PLUS_EXPR:
1286     case TRUNC_DIV_EXPR:
1287     case CEIL_DIV_EXPR:
1288     case FLOOR_DIV_EXPR:
1289     case TRUNC_MOD_EXPR:
1290     case RDIV_EXPR:
1291     case EXACT_DIV_EXPR:
1292     case LSHIFT_EXPR:
1293     case RSHIFT_EXPR:
1294     case BIT_IOR_EXPR:
1295     case BIT_XOR_EXPR:
1296     case BIT_AND_EXPR:
1297     case LT_EXPR:
1298     case LE_EXPR:
1299     case GT_EXPR:
1300     case GE_EXPR:
1301     case EQ_EXPR:
1302     case NE_EXPR:
1303     case COMPLEX_EXPR:
1304     case TRUTH_AND_EXPR:
1305     case TRUTH_OR_EXPR:
1306     case TRUTH_XOR_EXPR:
1307     case UNORDERED_EXPR:
1308     case ORDERED_EXPR:
1309     case UNLT_EXPR:
1310     case UNLE_EXPR:
1311     case UNGT_EXPR:
1312     case UNGE_EXPR:
1313     case UNEQ_EXPR:
1314       /* Binary operations evaluating both arguments (increment and
1315          decrement are binary internally in GCC).  */
1316       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1317       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1318       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1319                                    maybe_const_itself);
1320       STRIP_TYPE_NOPS (op0);
1321       if (code != MODIFY_EXPR
1322           && code != PREDECREMENT_EXPR
1323           && code != PREINCREMENT_EXPR
1324           && code != POSTDECREMENT_EXPR
1325           && code != POSTINCREMENT_EXPR)
1326         op0 = decl_constant_value_for_optimization (op0);
1327       /* The RHS of a MODIFY_EXPR was fully folded when building that
1328          expression for the sake of conversion warnings.  */
1329       if (code != MODIFY_EXPR)
1330         op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
1331                                      maybe_const_itself);
1332       STRIP_TYPE_NOPS (op1);
1333       op1 = decl_constant_value_for_optimization (op1);
1334       if (op0 != orig_op0 || op1 != orig_op1 || in_init)
1335         ret = in_init
1336           ? fold_build2_initializer_loc (loc, code, TREE_TYPE (expr), op0, op1)
1337           : fold_build2_loc (loc, code, TREE_TYPE (expr), op0, op1);
1338       else
1339         ret = fold (expr);
1340       if (TREE_OVERFLOW_P (ret)
1341           && !TREE_OVERFLOW_P (op0)
1342           && !TREE_OVERFLOW_P (op1))
1343         overflow_warning (EXPR_LOCATION (expr), ret);
1344       goto out;
1345
1346     case INDIRECT_REF:
1347     case FIX_TRUNC_EXPR:
1348     case FLOAT_EXPR:
1349     CASE_CONVERT:
1350     case NON_LVALUE_EXPR:
1351     case NEGATE_EXPR:
1352     case BIT_NOT_EXPR:
1353     case TRUTH_NOT_EXPR:
1354     case ADDR_EXPR:
1355     case CONJ_EXPR:
1356     case REALPART_EXPR:
1357     case IMAGPART_EXPR:
1358       /* Unary operations.  */
1359       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1360       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1361                                    maybe_const_itself);
1362       STRIP_TYPE_NOPS (op0);
1363       if (code != ADDR_EXPR && code != REALPART_EXPR && code != IMAGPART_EXPR)
1364         op0 = decl_constant_value_for_optimization (op0);
1365       if (op0 != orig_op0 || in_init)
1366         ret = in_init
1367           ? fold_build1_initializer_loc (loc, code, TREE_TYPE (expr), op0)
1368           : fold_build1_loc (loc, code, TREE_TYPE (expr), op0);
1369       else
1370         ret = fold (expr);
1371       if (code == INDIRECT_REF
1372           && ret != expr
1373           && TREE_CODE (ret) == INDIRECT_REF)
1374         {
1375           TREE_READONLY (ret) = TREE_READONLY (expr);
1376           TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (expr);
1377           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1378         }
1379       switch (code)
1380         {
1381         case FIX_TRUNC_EXPR:
1382         case FLOAT_EXPR:
1383         CASE_CONVERT:
1384           /* Don't warn about explicit conversions.  We will already
1385              have warned about suspect implicit conversions.  */
1386           break;
1387
1388         default:
1389           if (TREE_OVERFLOW_P (ret) && !TREE_OVERFLOW_P (op0))
1390             overflow_warning (EXPR_LOCATION (expr), ret);
1391           break;
1392         }
1393       goto out;
1394
1395     case TRUTH_ANDIF_EXPR:
1396     case TRUTH_ORIF_EXPR:
1397       /* Binary operations not necessarily evaluating both
1398          arguments.  */
1399       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1400       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1401       op0 = c_fully_fold_internal (op0, in_init, &op0_const, &op0_const_self);
1402       STRIP_TYPE_NOPS (op0);
1403
1404       unused_p = (op0 == (code == TRUTH_ANDIF_EXPR
1405                           ? truthvalue_false_node
1406                           : truthvalue_true_node));
1407       c_inhibit_evaluation_warnings += unused_p;
1408       op1 = c_fully_fold_internal (op1, in_init, &op1_const, &op1_const_self);
1409       STRIP_TYPE_NOPS (op1);
1410       c_inhibit_evaluation_warnings -= unused_p;
1411
1412       if (op0 != orig_op0 || op1 != orig_op1 || in_init)
1413         ret = in_init
1414           ? fold_build2_initializer_loc (loc, code, TREE_TYPE (expr), op0, op1)
1415           : fold_build2_loc (loc, code, TREE_TYPE (expr), op0, op1);
1416       else
1417         ret = fold (expr);
1418       *maybe_const_operands &= op0_const;
1419       *maybe_const_itself &= op0_const_self;
1420       if (!(flag_isoc99
1421             && op0_const
1422             && op0_const_self
1423             && (code == TRUTH_ANDIF_EXPR
1424                 ? op0 == truthvalue_false_node
1425                 : op0 == truthvalue_true_node)))
1426         *maybe_const_operands &= op1_const;
1427       if (!(op0_const
1428             && op0_const_self
1429             && (code == TRUTH_ANDIF_EXPR
1430                 ? op0 == truthvalue_false_node
1431                 : op0 == truthvalue_true_node)))
1432         *maybe_const_itself &= op1_const_self;
1433       goto out;
1434
1435     case COND_EXPR:
1436       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1437       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1438       orig_op2 = op2 = TREE_OPERAND (expr, 2);
1439       op0 = c_fully_fold_internal (op0, in_init, &op0_const, &op0_const_self);
1440
1441       STRIP_TYPE_NOPS (op0);
1442       c_inhibit_evaluation_warnings += (op0 == truthvalue_false_node);
1443       op1 = c_fully_fold_internal (op1, in_init, &op1_const, &op1_const_self);
1444       STRIP_TYPE_NOPS (op1);
1445       c_inhibit_evaluation_warnings -= (op0 == truthvalue_false_node);
1446
1447       c_inhibit_evaluation_warnings += (op0 == truthvalue_true_node);
1448       op2 = c_fully_fold_internal (op2, in_init, &op2_const, &op2_const_self);
1449       STRIP_TYPE_NOPS (op2);
1450       c_inhibit_evaluation_warnings -= (op0 == truthvalue_true_node);
1451
1452       if (op0 != orig_op0 || op1 != orig_op1 || op2 != orig_op2)
1453         ret = fold_build3_loc (loc, code, TREE_TYPE (expr), op0, op1, op2);
1454       else
1455         ret = fold (expr);
1456       *maybe_const_operands &= op0_const;
1457       *maybe_const_itself &= op0_const_self;
1458       if (!(flag_isoc99
1459             && op0_const
1460             && op0_const_self
1461             && op0 == truthvalue_false_node))
1462         *maybe_const_operands &= op1_const;
1463       if (!(op0_const
1464             && op0_const_self
1465             && op0 == truthvalue_false_node))
1466         *maybe_const_itself &= op1_const_self;
1467       if (!(flag_isoc99
1468             && op0_const
1469             && op0_const_self
1470             && op0 == truthvalue_true_node))
1471         *maybe_const_operands &= op2_const;
1472       if (!(op0_const
1473             && op0_const_self
1474             && op0 == truthvalue_true_node))
1475         *maybe_const_itself &= op2_const_self;
1476       goto out;
1477
1478     case EXCESS_PRECISION_EXPR:
1479       /* Each case where an operand with excess precision may be
1480          encountered must remove the EXCESS_PRECISION_EXPR around
1481          inner operands and possibly put one around the whole
1482          expression or possibly convert to the semantic type (which
1483          c_fully_fold does); we cannot tell at this stage which is
1484          appropriate in any particular case.  */
1485       gcc_unreachable ();
1486
1487     default:
1488       /* Various codes may appear through folding built-in functions
1489          and their arguments.  */
1490       goto out;
1491     }
1492
1493  out:
1494   /* Some folding may introduce NON_LVALUE_EXPRs; all lvalue checks
1495      have been done by this point, so remove them again.  */
1496   nowarning |= TREE_NO_WARNING (ret);
1497   STRIP_TYPE_NOPS (ret);
1498   if (nowarning && !TREE_NO_WARNING (ret))
1499     {
1500       if (!CAN_HAVE_LOCATION_P (ret))
1501         ret = build1 (NOP_EXPR, TREE_TYPE (ret), ret);
1502       TREE_NO_WARNING (ret) = 1;
1503     }
1504   if (ret != expr)
1505     protected_set_expr_location (ret, loc);
1506   return ret;
1507 }
1508
1509 /* If not optimizing, EXP is not a VAR_DECL, or EXP has array type,
1510    return EXP.  Otherwise, return either EXP or its known constant
1511    value (if it has one), but return EXP if EXP has mode BLKmode.  ???
1512    Is the BLKmode test appropriate?  */
1513
1514 tree
1515 decl_constant_value_for_optimization (tree exp)
1516 {
1517   tree ret;
1518
1519   /* This function is only used by C, for c_fully_fold and other
1520      optimization, and may not be correct for C++.  */
1521   if (c_dialect_cxx ())
1522     gcc_unreachable ();
1523
1524   if (!optimize
1525       || TREE_CODE (exp) != VAR_DECL
1526       || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
1527       || DECL_MODE (exp) == BLKmode)
1528     return exp;
1529
1530   ret = decl_constant_value (exp);
1531   /* Avoid unwanted tree sharing between the initializer and current
1532      function's body where the tree can be modified e.g. by the
1533      gimplifier.  */
1534   if (ret != exp && TREE_STATIC (exp))
1535     ret = unshare_expr (ret);
1536   return ret;
1537 }
1538
1539 /* Print a warning if a constant expression had overflow in folding.
1540    Invoke this function on every expression that the language
1541    requires to be a constant expression.
1542    Note the ANSI C standard says it is erroneous for a
1543    constant expression to overflow.  */
1544
1545 void
1546 constant_expression_warning (tree value)
1547 {
1548   if (warn_overflow && pedantic
1549       && (TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
1550           || TREE_CODE (value) == FIXED_CST
1551           || TREE_CODE (value) == VECTOR_CST
1552           || TREE_CODE (value) == COMPLEX_CST)
1553       && TREE_OVERFLOW (value))
1554     pedwarn (input_location, OPT_Woverflow, "overflow in constant expression");
1555 }
1556
1557 /* The same as above but print an unconditional error.  */
1558 void
1559 constant_expression_error (tree value)
1560 {
1561   if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
1562        || TREE_CODE (value) == FIXED_CST
1563        || TREE_CODE (value) == VECTOR_CST
1564        || TREE_CODE (value) == COMPLEX_CST)
1565       && TREE_OVERFLOW (value))
1566     error ("overflow in constant expression");
1567 }
1568
1569 /* Print a warning if an expression had overflow in folding and its
1570    operands hadn't.
1571
1572    Invoke this function on every expression that
1573    (1) appears in the source code, and
1574    (2) is a constant expression that overflowed, and
1575    (3) is not already checked by convert_and_check;
1576    however, do not invoke this function on operands of explicit casts
1577    or when the expression is the result of an operator and any operand
1578    already overflowed.  */
1579
1580 void
1581 overflow_warning (location_t loc, tree value)
1582 {
1583   if (c_inhibit_evaluation_warnings != 0)
1584     return;
1585
1586   switch (TREE_CODE (value))
1587     {
1588     case INTEGER_CST:
1589       warning_at (loc, OPT_Woverflow, "integer overflow in expression");
1590       break;
1591
1592     case REAL_CST:
1593       warning_at (loc, OPT_Woverflow,
1594                   "floating point overflow in expression");
1595       break;
1596
1597     case FIXED_CST:
1598       warning_at (loc, OPT_Woverflow, "fixed-point overflow in expression");
1599       break;
1600
1601     case VECTOR_CST:
1602       warning_at (loc, OPT_Woverflow, "vector overflow in expression");
1603       break;
1604
1605     case COMPLEX_CST:
1606       if (TREE_CODE (TREE_REALPART (value)) == INTEGER_CST)
1607         warning_at (loc, OPT_Woverflow,
1608                     "complex integer overflow in expression");
1609       else if (TREE_CODE (TREE_REALPART (value)) == REAL_CST)
1610         warning_at (loc, OPT_Woverflow,
1611                     "complex floating point overflow in expression");
1612       break;
1613
1614     default:
1615       break;
1616     }
1617 }
1618
1619 /* Warn about uses of logical || / && operator in a context where it
1620    is likely that the bitwise equivalent was intended by the
1621    programmer.  We have seen an expression in which CODE is a binary
1622    operator used to combine expressions OP_LEFT and OP_RIGHT, which before folding
1623    had CODE_LEFT and CODE_RIGHT, into an expression of type TYPE.  */
1624 void
1625 warn_logical_operator (location_t location, enum tree_code code, tree type,
1626                        enum tree_code code_left, tree op_left,
1627                        enum tree_code ARG_UNUSED (code_right), tree op_right)
1628 {
1629   int or_op = (code == TRUTH_ORIF_EXPR || code == TRUTH_OR_EXPR);
1630   int in0_p, in1_p, in_p;
1631   tree low0, low1, low, high0, high1, high, lhs, rhs, tem;
1632   bool strict_overflow_p = false;
1633
1634   if (code != TRUTH_ANDIF_EXPR
1635       && code != TRUTH_AND_EXPR
1636       && code != TRUTH_ORIF_EXPR
1637       && code != TRUTH_OR_EXPR)
1638     return;
1639
1640   /* Warn if &&/|| are being used in a context where it is
1641      likely that the bitwise equivalent was intended by the
1642      programmer. That is, an expression such as op && MASK
1643      where op should not be any boolean expression, nor a
1644      constant, and mask seems to be a non-boolean integer constant.  */
1645   if (!truth_value_p (code_left)
1646       && INTEGRAL_TYPE_P (TREE_TYPE (op_left))
1647       && !CONSTANT_CLASS_P (op_left)
1648       && !TREE_NO_WARNING (op_left)
1649       && TREE_CODE (op_right) == INTEGER_CST
1650       && !integer_zerop (op_right)
1651       && !integer_onep (op_right))
1652     {
1653       if (or_op)
1654         warning_at (location, OPT_Wlogical_op, "logical %<or%>"
1655                     " applied to non-boolean constant");
1656       else
1657         warning_at (location, OPT_Wlogical_op, "logical %<and%>"
1658                     " applied to non-boolean constant");
1659       TREE_NO_WARNING (op_left) = true;
1660       return;
1661     }
1662
1663   /* We do not warn for constants because they are typical of macro
1664      expansions that test for features.  */
1665   if (CONSTANT_CLASS_P (op_left) || CONSTANT_CLASS_P (op_right))
1666     return;
1667
1668   /* This warning only makes sense with logical operands.  */
1669   if (!(truth_value_p (TREE_CODE (op_left))
1670         || INTEGRAL_TYPE_P (TREE_TYPE (op_left)))
1671       || !(truth_value_p (TREE_CODE (op_right))
1672            || INTEGRAL_TYPE_P (TREE_TYPE (op_right))))
1673     return;
1674
1675   lhs = make_range (op_left, &in0_p, &low0, &high0, &strict_overflow_p);
1676   rhs = make_range (op_right, &in1_p, &low1, &high1, &strict_overflow_p);
1677
1678   if (lhs && TREE_CODE (lhs) == C_MAYBE_CONST_EXPR)
1679     lhs = C_MAYBE_CONST_EXPR_EXPR (lhs);
1680
1681   if (rhs && TREE_CODE (rhs) == C_MAYBE_CONST_EXPR)
1682     rhs = C_MAYBE_CONST_EXPR_EXPR (rhs);
1683
1684   /* If this is an OR operation, invert both sides; we will invert
1685      again at the end.  */
1686   if (or_op)
1687     in0_p = !in0_p, in1_p = !in1_p;
1688
1689   /* If both expressions are the same, if we can merge the ranges, and we
1690      can build the range test, return it or it inverted.  */
1691   if (lhs && rhs && operand_equal_p (lhs, rhs, 0)
1692       && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
1693                        in1_p, low1, high1)
1694       && 0 != (tem = build_range_check (UNKNOWN_LOCATION,
1695                                         type, lhs, in_p, low, high)))
1696     {
1697       if (TREE_CODE (tem) != INTEGER_CST)
1698         return;
1699
1700       if (or_op)
1701         warning_at (location, OPT_Wlogical_op,
1702                     "logical %<or%> "
1703                     "of collectively exhaustive tests is always true");
1704       else
1705         warning_at (location, OPT_Wlogical_op,
1706                     "logical %<and%> "
1707                     "of mutually exclusive tests is always false");
1708     }
1709 }
1710
1711
1712 /* Print a warning about casts that might indicate violation
1713    of strict aliasing rules if -Wstrict-aliasing is used and
1714    strict aliasing mode is in effect. OTYPE is the original
1715    TREE_TYPE of EXPR, and TYPE the type we're casting to. */
1716
1717 bool
1718 strict_aliasing_warning (tree otype, tree type, tree expr)
1719 {
1720   /* Strip pointer conversion chains and get to the correct original type.  */
1721   STRIP_NOPS (expr);
1722   otype = TREE_TYPE (expr);
1723
1724   if (!(flag_strict_aliasing
1725         && POINTER_TYPE_P (type)
1726         && POINTER_TYPE_P (otype)
1727         && !VOID_TYPE_P (TREE_TYPE (type)))
1728       /* If the type we are casting to is a ref-all pointer
1729          dereferencing it is always valid.  */
1730       || TYPE_REF_CAN_ALIAS_ALL (type))
1731     return false;
1732
1733   if ((warn_strict_aliasing > 1) && TREE_CODE (expr) == ADDR_EXPR
1734       && (DECL_P (TREE_OPERAND (expr, 0))
1735           || handled_component_p (TREE_OPERAND (expr, 0))))
1736     {
1737       /* Casting the address of an object to non void pointer. Warn
1738          if the cast breaks type based aliasing.  */
1739       if (!COMPLETE_TYPE_P (TREE_TYPE (type)) && warn_strict_aliasing == 2)
1740         {
1741           warning (OPT_Wstrict_aliasing, "type-punning to incomplete type "
1742                    "might break strict-aliasing rules");
1743           return true;
1744         }
1745       else
1746         {
1747           /* warn_strict_aliasing >= 3.   This includes the default (3).
1748              Only warn if the cast is dereferenced immediately.  */
1749           alias_set_type set1 =
1750             get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0)));
1751           alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1752
1753           if (set1 != set2 && set2 != 0
1754               && (set1 == 0 || !alias_sets_conflict_p (set1, set2)))
1755             {
1756               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1757                        "pointer will break strict-aliasing rules");
1758               return true;
1759             }
1760           else if (warn_strict_aliasing == 2
1761                    && !alias_sets_must_conflict_p (set1, set2))
1762             {
1763               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1764                        "pointer might break strict-aliasing rules");
1765               return true;
1766             }
1767         }
1768     }
1769   else
1770     if ((warn_strict_aliasing == 1) && !VOID_TYPE_P (TREE_TYPE (otype)))
1771       {
1772         /* At this level, warn for any conversions, even if an address is
1773            not taken in the same statement.  This will likely produce many
1774            false positives, but could be useful to pinpoint problems that
1775            are not revealed at higher levels.  */
1776         alias_set_type set1 = get_alias_set (TREE_TYPE (otype));
1777         alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1778         if (!COMPLETE_TYPE_P (type)
1779             || !alias_sets_must_conflict_p (set1, set2))
1780           {
1781             warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1782                      "pointer might break strict-aliasing rules");
1783             return true;
1784           }
1785       }
1786
1787   return false;
1788 }
1789
1790 /* Warn for unlikely, improbable, or stupid DECL declarations
1791    of `main'.  */
1792
1793 void
1794 check_main_parameter_types (tree decl)
1795 {
1796   tree args;
1797   int argct = 0;
1798
1799   for (args = TYPE_ARG_TYPES (TREE_TYPE (decl)); args;
1800       args = TREE_CHAIN (args))
1801    {
1802      tree type = args ? TREE_VALUE (args) : 0;
1803
1804      if (type == void_type_node || type == error_mark_node )
1805        break;
1806
1807      ++argct;
1808      switch (argct)
1809        {
1810        case 1:
1811          if (TYPE_MAIN_VARIANT (type) != integer_type_node)
1812            pedwarn (input_location, OPT_Wmain, "first argument of %q+D should be %<int%>",
1813                     decl);
1814          break;
1815
1816        case 2:
1817          if (TREE_CODE (type) != POINTER_TYPE
1818              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1819              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1820                  != char_type_node))
1821            pedwarn (input_location, OPT_Wmain, "second argument of %q+D should be %<char **%>",
1822                     decl);
1823          break;
1824
1825        case 3:
1826          if (TREE_CODE (type) != POINTER_TYPE
1827              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1828              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1829                  != char_type_node))
1830            pedwarn (input_location, OPT_Wmain, "third argument of %q+D should probably be "
1831                     "%<char **%>", decl);
1832          break;
1833        }
1834    }
1835
1836   /* It is intentional that this message does not mention the third
1837     argument because it's only mentioned in an appendix of the
1838     standard.  */
1839   if (argct > 0 && (argct < 2 || argct > 3))
1840     pedwarn (input_location, OPT_Wmain, "%q+D takes only zero or two arguments", decl);
1841 }
1842
1843 /* True if pointers to distinct types T1 and T2 can be converted to
1844    each other without an explicit cast.  Only returns true for opaque
1845    vector types.  */
1846 bool
1847 vector_targets_convertible_p (const_tree t1, const_tree t2)
1848 {
1849   if (TREE_CODE (t1) == VECTOR_TYPE && TREE_CODE (t2) == VECTOR_TYPE
1850       && (TYPE_VECTOR_OPAQUE (t1) || TYPE_VECTOR_OPAQUE (t2))
1851       && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)))
1852     return true;
1853
1854   return false;
1855 }
1856
1857 /* True if vector types T1 and T2 can be converted to each other
1858    without an explicit cast.  If EMIT_LAX_NOTE is true, and T1 and T2
1859    can only be converted with -flax-vector-conversions yet that is not
1860    in effect, emit a note telling the user about that option if such
1861    a note has not previously been emitted.  */
1862 bool
1863 vector_types_convertible_p (const_tree t1, const_tree t2, bool emit_lax_note)
1864 {
1865   static bool emitted_lax_note = false;
1866   bool convertible_lax;
1867
1868   if ((TYPE_VECTOR_OPAQUE (t1) || TYPE_VECTOR_OPAQUE (t2))
1869       && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)))
1870     return true;
1871
1872   convertible_lax =
1873     (tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2))
1874      && (TREE_CODE (TREE_TYPE (t1)) != REAL_TYPE ||
1875          TYPE_PRECISION (t1) == TYPE_PRECISION (t2))
1876      && (INTEGRAL_TYPE_P (TREE_TYPE (t1))
1877          == INTEGRAL_TYPE_P (TREE_TYPE (t2))));
1878
1879   if (!convertible_lax || flag_lax_vector_conversions)
1880     return convertible_lax;
1881
1882   if (TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1883       && lang_hooks.types_compatible_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1884     return true;
1885
1886   if (emit_lax_note && !emitted_lax_note)
1887     {
1888       emitted_lax_note = true;
1889       inform (input_location, "use -flax-vector-conversions to permit "
1890               "conversions between vectors with differing "
1891               "element types or numbers of subparts");
1892     }
1893
1894   return false;
1895 }
1896
1897 /* This is a helper function of build_binary_op.
1898
1899    For certain operations if both args were extended from the same
1900    smaller type, do the arithmetic in that type and then extend.
1901
1902    BITWISE indicates a bitwise operation.
1903    For them, this optimization is safe only if
1904    both args are zero-extended or both are sign-extended.
1905    Otherwise, we might change the result.
1906    Eg, (short)-1 | (unsigned short)-1 is (int)-1
1907    but calculated in (unsigned short) it would be (unsigned short)-1.
1908 */
1909 tree shorten_binary_op (tree result_type, tree op0, tree op1, bool bitwise)
1910 {
1911   int unsigned0, unsigned1;
1912   tree arg0, arg1;
1913   int uns;
1914   tree type;
1915
1916   /* Cast OP0 and OP1 to RESULT_TYPE.  Doing so prevents
1917      excessive narrowing when we call get_narrower below.  For
1918      example, suppose that OP0 is of unsigned int extended
1919      from signed char and that RESULT_TYPE is long long int.
1920      If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
1921      like
1922
1923      (long long int) (unsigned int) signed_char
1924
1925      which get_narrower would narrow down to
1926
1927      (unsigned int) signed char
1928
1929      If we do not cast OP0 first, get_narrower would return
1930      signed_char, which is inconsistent with the case of the
1931      explicit cast.  */
1932   op0 = convert (result_type, op0);
1933   op1 = convert (result_type, op1);
1934
1935   arg0 = get_narrower (op0, &unsigned0);
1936   arg1 = get_narrower (op1, &unsigned1);
1937
1938   /* UNS is 1 if the operation to be done is an unsigned one.  */
1939   uns = TYPE_UNSIGNED (result_type);
1940
1941   /* Handle the case that OP0 (or OP1) does not *contain* a conversion
1942      but it *requires* conversion to FINAL_TYPE.  */
1943
1944   if ((TYPE_PRECISION (TREE_TYPE (op0))
1945        == TYPE_PRECISION (TREE_TYPE (arg0)))
1946       && TREE_TYPE (op0) != result_type)
1947     unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
1948   if ((TYPE_PRECISION (TREE_TYPE (op1))
1949        == TYPE_PRECISION (TREE_TYPE (arg1)))
1950       && TREE_TYPE (op1) != result_type)
1951     unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
1952
1953   /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE.  */
1954
1955   /* For bitwise operations, signedness of nominal type
1956      does not matter.  Consider only how operands were extended.  */
1957   if (bitwise)
1958     uns = unsigned0;
1959
1960   /* Note that in all three cases below we refrain from optimizing
1961      an unsigned operation on sign-extended args.
1962      That would not be valid.  */
1963
1964   /* Both args variable: if both extended in same way
1965      from same width, do it in that width.
1966      Do it unsigned if args were zero-extended.  */
1967   if ((TYPE_PRECISION (TREE_TYPE (arg0))
1968        < TYPE_PRECISION (result_type))
1969       && (TYPE_PRECISION (TREE_TYPE (arg1))
1970           == TYPE_PRECISION (TREE_TYPE (arg0)))
1971       && unsigned0 == unsigned1
1972       && (unsigned0 || !uns))
1973     return c_common_signed_or_unsigned_type
1974       (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
1975
1976   else if (TREE_CODE (arg0) == INTEGER_CST
1977            && (unsigned1 || !uns)
1978            && (TYPE_PRECISION (TREE_TYPE (arg1))
1979                < TYPE_PRECISION (result_type))
1980            && (type
1981                = c_common_signed_or_unsigned_type (unsigned1,
1982                                                    TREE_TYPE (arg1)))
1983            && !POINTER_TYPE_P (type)
1984            && int_fits_type_p (arg0, type))
1985     return type;
1986
1987   else if (TREE_CODE (arg1) == INTEGER_CST
1988            && (unsigned0 || !uns)
1989            && (TYPE_PRECISION (TREE_TYPE (arg0))
1990                < TYPE_PRECISION (result_type))
1991            && (type
1992                = c_common_signed_or_unsigned_type (unsigned0,
1993                                                    TREE_TYPE (arg0)))
1994            && !POINTER_TYPE_P (type)
1995            && int_fits_type_p (arg1, type))
1996     return type;
1997
1998   return result_type;
1999 }
2000
2001 /* Warns if the conversion of EXPR to TYPE may alter a value.
2002    This is a helper function for warnings_for_convert_and_check.  */
2003
2004 static void
2005 conversion_warning (tree type, tree expr)
2006 {
2007   bool give_warning = false;
2008
2009   int i;
2010   const int expr_num_operands = TREE_OPERAND_LENGTH (expr);
2011   tree expr_type = TREE_TYPE (expr);
2012
2013   if (!warn_conversion && !warn_sign_conversion)
2014     return;
2015
2016   /* If any operand is artificial, then this expression was generated
2017      by the compiler and we do not warn.  */
2018   for (i = 0; i < expr_num_operands; i++)
2019     {
2020       tree op = TREE_OPERAND (expr, i);
2021       if (op && DECL_P (op) && DECL_ARTIFICIAL (op))
2022         return;
2023     }
2024
2025   switch (TREE_CODE (expr))
2026     {
2027     case EQ_EXPR:
2028     case NE_EXPR:
2029     case LE_EXPR:
2030     case GE_EXPR:
2031     case LT_EXPR:
2032     case GT_EXPR:
2033     case TRUTH_ANDIF_EXPR:
2034     case TRUTH_ORIF_EXPR:
2035     case TRUTH_AND_EXPR:
2036     case TRUTH_OR_EXPR:
2037     case TRUTH_XOR_EXPR:
2038     case TRUTH_NOT_EXPR:
2039       /* Conversion from boolean to a signed:1 bit-field (which only
2040          can hold the values 0 and -1) doesn't lose information - but
2041          it does change the value.  */
2042       if (TYPE_PRECISION (type) == 1 && !TYPE_UNSIGNED (type))
2043         warning (OPT_Wconversion,
2044                  "conversion to %qT from boolean expression", type);
2045       return;
2046
2047     case REAL_CST:
2048     case INTEGER_CST:
2049
2050       /* Warn for real constant that is not an exact integer converted
2051          to integer type.  */
2052       if (TREE_CODE (expr_type) == REAL_TYPE
2053           && TREE_CODE (type) == INTEGER_TYPE)
2054         {
2055           if (!real_isinteger (TREE_REAL_CST_PTR (expr), TYPE_MODE (expr_type)))
2056             give_warning = true;
2057         }
2058       /* Warn for an integer constant that does not fit into integer type.  */
2059       else if (TREE_CODE (expr_type) == INTEGER_TYPE
2060                && TREE_CODE (type) == INTEGER_TYPE
2061                && !int_fits_type_p (expr, type))
2062         {
2063           if (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (expr_type)
2064               && tree_int_cst_sgn (expr) < 0)
2065             warning (OPT_Wsign_conversion,
2066                      "negative integer implicitly converted to unsigned type");
2067           else if (!TYPE_UNSIGNED (type) && TYPE_UNSIGNED (expr_type))
2068             warning (OPT_Wsign_conversion,  "conversion of unsigned constant "
2069                      "value to negative integer");
2070           else
2071             give_warning = true;
2072         }
2073       else if (TREE_CODE (type) == REAL_TYPE)
2074         {
2075           /* Warn for an integer constant that does not fit into real type.  */
2076           if (TREE_CODE (expr_type) == INTEGER_TYPE)
2077             {
2078               REAL_VALUE_TYPE a = real_value_from_int_cst (0, expr);
2079               if (!exact_real_truncate (TYPE_MODE (type), &a))
2080                 give_warning = true;
2081             }
2082           /* Warn for a real constant that does not fit into a smaller
2083              real type.  */
2084           else if (TREE_CODE (expr_type) == REAL_TYPE
2085                    && TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2086             {
2087               REAL_VALUE_TYPE a = TREE_REAL_CST (expr);
2088               if (!exact_real_truncate (TYPE_MODE (type), &a))
2089                 give_warning = true;
2090             }
2091         }
2092
2093       if (give_warning)
2094         warning (OPT_Wconversion,
2095                  "conversion to %qT alters %qT constant value",
2096                  type, expr_type);
2097
2098       return;
2099
2100     case COND_EXPR:
2101       {
2102         /* In case of COND_EXPR, if both operands are constants or
2103            COND_EXPR, then we do not care about the type of COND_EXPR,
2104            only about the conversion of each operand.  */
2105         tree op1 = TREE_OPERAND (expr, 1);
2106         tree op2 = TREE_OPERAND (expr, 2);
2107
2108         if ((TREE_CODE (op1) == REAL_CST || TREE_CODE (op1) == INTEGER_CST
2109              || TREE_CODE (op1) == COND_EXPR)
2110             && (TREE_CODE (op2) == REAL_CST || TREE_CODE (op2) == INTEGER_CST
2111                 || TREE_CODE (op2) == COND_EXPR))
2112           {
2113             conversion_warning (type, op1);
2114             conversion_warning (type, op2);
2115             return;
2116           }
2117         /* Fall through.  */
2118       }
2119
2120     default: /* 'expr' is not a constant.  */
2121
2122       /* Warn for real types converted to integer types.  */
2123       if (TREE_CODE (expr_type) == REAL_TYPE
2124           && TREE_CODE (type) == INTEGER_TYPE)
2125         give_warning = true;
2126
2127       else if (TREE_CODE (expr_type) == INTEGER_TYPE
2128                && TREE_CODE (type) == INTEGER_TYPE)
2129         {
2130           /* Don't warn about unsigned char y = 0xff, x = (int) y;  */
2131           expr = get_unwidened (expr, 0);
2132           expr_type = TREE_TYPE (expr);
2133
2134           /* Don't warn for short y; short x = ((int)y & 0xff);  */
2135           if (TREE_CODE (expr) == BIT_AND_EXPR
2136                 || TREE_CODE (expr) == BIT_IOR_EXPR
2137               || TREE_CODE (expr) == BIT_XOR_EXPR)
2138             {
2139               /* If both args were extended from a shortest type,
2140                  use that type if that is safe.  */
2141               expr_type = shorten_binary_op (expr_type,
2142                                              TREE_OPERAND (expr, 0),
2143                                              TREE_OPERAND (expr, 1),
2144                                              /* bitwise */1);
2145
2146               if (TREE_CODE (expr) == BIT_AND_EXPR)
2147                 {
2148                   tree op0 = TREE_OPERAND (expr, 0);
2149                   tree op1 = TREE_OPERAND (expr, 1);
2150                   bool unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
2151                   bool unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
2152
2153                   /* If one of the operands is a non-negative constant
2154                      that fits in the target type, then the type of the
2155                      other operand does not matter. */
2156                   if ((TREE_CODE (op0) == INTEGER_CST
2157                        && int_fits_type_p (op0, c_common_signed_type (type))
2158                        && int_fits_type_p (op0, c_common_unsigned_type (type)))
2159                       || (TREE_CODE (op1) == INTEGER_CST
2160                           && int_fits_type_p (op1, c_common_signed_type (type))
2161                           && int_fits_type_p (op1,
2162                                               c_common_unsigned_type (type))))
2163                     return;
2164                   /* If constant is unsigned and fits in the target
2165                      type, then the result will also fit.  */
2166                   else if ((TREE_CODE (op0) == INTEGER_CST
2167                             && unsigned0
2168                             && int_fits_type_p (op0, type))
2169                            || (TREE_CODE (op1) == INTEGER_CST
2170                                && unsigned1
2171                                && int_fits_type_p (op1, type)))
2172                     return;
2173                 }
2174             }
2175           /* Warn for integer types converted to smaller integer types.  */
2176           if (TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2177             give_warning = true;
2178
2179           /* When they are the same width but different signedness,
2180              then the value may change.  */
2181           else if ((TYPE_PRECISION (type) == TYPE_PRECISION (expr_type)
2182                     && TYPE_UNSIGNED (expr_type) != TYPE_UNSIGNED (type))
2183                    /* Even when converted to a bigger type, if the type is
2184                       unsigned but expr is signed, then negative values
2185                       will be changed.  */
2186                    || (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (expr_type)))
2187             warning (OPT_Wsign_conversion, "conversion to %qT from %qT "
2188                      "may change the sign of the result",
2189                      type, expr_type);
2190         }
2191
2192       /* Warn for integer types converted to real types if and only if
2193          all the range of values of the integer type cannot be
2194          represented by the real type.  */
2195       else if (TREE_CODE (expr_type) == INTEGER_TYPE
2196                && TREE_CODE (type) == REAL_TYPE)
2197         {
2198           tree type_low_bound, type_high_bound;
2199           REAL_VALUE_TYPE real_low_bound, real_high_bound;
2200
2201           /* Don't warn about char y = 0xff; float x = (int) y;  */
2202           expr = get_unwidened (expr, 0);
2203           expr_type = TREE_TYPE (expr);
2204
2205           type_low_bound = TYPE_MIN_VALUE (expr_type);
2206           type_high_bound = TYPE_MAX_VALUE (expr_type);
2207           real_low_bound = real_value_from_int_cst (0, type_low_bound);
2208           real_high_bound = real_value_from_int_cst (0, type_high_bound);
2209
2210           if (!exact_real_truncate (TYPE_MODE (type), &real_low_bound)
2211               || !exact_real_truncate (TYPE_MODE (type), &real_high_bound))
2212             give_warning = true;
2213         }
2214
2215       /* Warn for real types converted to smaller real types.  */
2216       else if (TREE_CODE (expr_type) == REAL_TYPE
2217                && TREE_CODE (type) == REAL_TYPE
2218                && TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2219         give_warning = true;
2220
2221
2222       if (give_warning)
2223         warning (OPT_Wconversion,
2224                  "conversion to %qT from %qT may alter its value",
2225                  type, expr_type);
2226     }
2227 }
2228
2229 /* Produce warnings after a conversion. RESULT is the result of
2230    converting EXPR to TYPE.  This is a helper function for
2231    convert_and_check and cp_convert_and_check.  */
2232
2233 void
2234 warnings_for_convert_and_check (tree type, tree expr, tree result)
2235 {
2236   if (TREE_CODE (expr) == INTEGER_CST
2237       && (TREE_CODE (type) == INTEGER_TYPE
2238           || TREE_CODE (type) == ENUMERAL_TYPE)
2239       && !int_fits_type_p (expr, type))
2240     {
2241       /* Do not diagnose overflow in a constant expression merely
2242          because a conversion overflowed.  */
2243       if (TREE_OVERFLOW (result))
2244         TREE_OVERFLOW (result) = TREE_OVERFLOW (expr);
2245
2246       if (TYPE_UNSIGNED (type))
2247         {
2248           /* This detects cases like converting -129 or 256 to
2249              unsigned char.  */
2250           if (!int_fits_type_p (expr, c_common_signed_type (type)))
2251             warning (OPT_Woverflow,
2252                      "large integer implicitly truncated to unsigned type");
2253           else
2254             conversion_warning (type, expr);
2255         }
2256       else if (!int_fits_type_p (expr, c_common_unsigned_type (type)))
2257         warning (OPT_Woverflow,
2258                  "overflow in implicit constant conversion");
2259       /* No warning for converting 0x80000000 to int.  */
2260       else if (pedantic
2261                && (TREE_CODE (TREE_TYPE (expr)) != INTEGER_TYPE
2262                    || TYPE_PRECISION (TREE_TYPE (expr))
2263                    != TYPE_PRECISION (type)))
2264         warning (OPT_Woverflow,
2265                  "overflow in implicit constant conversion");
2266
2267       else
2268         conversion_warning (type, expr);
2269     }
2270   else if ((TREE_CODE (result) == INTEGER_CST
2271             || TREE_CODE (result) == FIXED_CST) && TREE_OVERFLOW (result))
2272     warning (OPT_Woverflow,
2273              "overflow in implicit constant conversion");
2274   else
2275     conversion_warning (type, expr);
2276 }
2277
2278
2279 /* Convert EXPR to TYPE, warning about conversion problems with constants.
2280    Invoke this function on every expression that is converted implicitly,
2281    i.e. because of language rules and not because of an explicit cast.  */
2282
2283 tree
2284 convert_and_check (tree type, tree expr)
2285 {
2286   tree result;
2287   tree expr_for_warning;
2288
2289   /* Convert from a value with possible excess precision rather than
2290      via the semantic type, but do not warn about values not fitting
2291      exactly in the semantic type.  */
2292   if (TREE_CODE (expr) == EXCESS_PRECISION_EXPR)
2293     {
2294       tree orig_type = TREE_TYPE (expr);
2295       expr = TREE_OPERAND (expr, 0);
2296       expr_for_warning = convert (orig_type, expr);
2297       if (orig_type == type)
2298         return expr_for_warning;
2299     }
2300   else
2301     expr_for_warning = expr;
2302
2303   if (TREE_TYPE (expr) == type)
2304     return expr;
2305
2306   result = convert (type, expr);
2307
2308   if (c_inhibit_evaluation_warnings == 0
2309       && !TREE_OVERFLOW_P (expr)
2310       && result != error_mark_node)
2311     warnings_for_convert_and_check (type, expr_for_warning, result);
2312
2313   return result;
2314 }
2315 \f
2316 /* A node in a list that describes references to variables (EXPR), which are
2317    either read accesses if WRITER is zero, or write accesses, in which case
2318    WRITER is the parent of EXPR.  */
2319 struct tlist
2320 {
2321   struct tlist *next;
2322   tree expr, writer;
2323 };
2324
2325 /* Used to implement a cache the results of a call to verify_tree.  We only
2326    use this for SAVE_EXPRs.  */
2327 struct tlist_cache
2328 {
2329   struct tlist_cache *next;
2330   struct tlist *cache_before_sp;
2331   struct tlist *cache_after_sp;
2332   tree expr;
2333 };
2334
2335 /* Obstack to use when allocating tlist structures, and corresponding
2336    firstobj.  */
2337 static struct obstack tlist_obstack;
2338 static char *tlist_firstobj = 0;
2339
2340 /* Keep track of the identifiers we've warned about, so we can avoid duplicate
2341    warnings.  */
2342 static struct tlist *warned_ids;
2343 /* SAVE_EXPRs need special treatment.  We process them only once and then
2344    cache the results.  */
2345 static struct tlist_cache *save_expr_cache;
2346
2347 static void add_tlist (struct tlist **, struct tlist *, tree, int);
2348 static void merge_tlist (struct tlist **, struct tlist *, int);
2349 static void verify_tree (tree, struct tlist **, struct tlist **, tree);
2350 static int warning_candidate_p (tree);
2351 static bool candidate_equal_p (const_tree, const_tree);
2352 static void warn_for_collisions (struct tlist *);
2353 static void warn_for_collisions_1 (tree, tree, struct tlist *, int);
2354 static struct tlist *new_tlist (struct tlist *, tree, tree);
2355
2356 /* Create a new struct tlist and fill in its fields.  */
2357 static struct tlist *
2358 new_tlist (struct tlist *next, tree t, tree writer)
2359 {
2360   struct tlist *l;
2361   l = XOBNEW (&tlist_obstack, struct tlist);
2362   l->next = next;
2363   l->expr = t;
2364   l->writer = writer;
2365   return l;
2366 }
2367
2368 /* Add duplicates of the nodes found in ADD to the list *TO.  If EXCLUDE_WRITER
2369    is nonnull, we ignore any node we find which has a writer equal to it.  */
2370
2371 static void
2372 add_tlist (struct tlist **to, struct tlist *add, tree exclude_writer, int copy)
2373 {
2374   while (add)
2375     {
2376       struct tlist *next = add->next;
2377       if (!copy)
2378         add->next = *to;
2379       if (!exclude_writer || !candidate_equal_p (add->writer, exclude_writer))
2380         *to = copy ? new_tlist (*to, add->expr, add->writer) : add;
2381       add = next;
2382     }
2383 }
2384
2385 /* Merge the nodes of ADD into TO.  This merging process is done so that for
2386    each variable that already exists in TO, no new node is added; however if
2387    there is a write access recorded in ADD, and an occurrence on TO is only
2388    a read access, then the occurrence in TO will be modified to record the
2389    write.  */
2390
2391 static void
2392 merge_tlist (struct tlist **to, struct tlist *add, int copy)
2393 {
2394   struct tlist **end = to;
2395
2396   while (*end)
2397     end = &(*end)->next;
2398
2399   while (add)
2400     {
2401       int found = 0;
2402       struct tlist *tmp2;
2403       struct tlist *next = add->next;
2404
2405       for (tmp2 = *to; tmp2; tmp2 = tmp2->next)
2406         if (candidate_equal_p (tmp2->expr, add->expr))
2407           {
2408             found = 1;
2409             if (!tmp2->writer)
2410               tmp2->writer = add->writer;
2411           }
2412       if (!found)
2413         {
2414           *end = copy ? add : new_tlist (NULL, add->expr, add->writer);
2415           end = &(*end)->next;
2416           *end = 0;
2417         }
2418       add = next;
2419     }
2420 }
2421
2422 /* WRITTEN is a variable, WRITER is its parent.  Warn if any of the variable
2423    references in list LIST conflict with it, excluding reads if ONLY writers
2424    is nonzero.  */
2425
2426 static void
2427 warn_for_collisions_1 (tree written, tree writer, struct tlist *list,
2428                        int only_writes)
2429 {
2430   struct tlist *tmp;
2431
2432   /* Avoid duplicate warnings.  */
2433   for (tmp = warned_ids; tmp; tmp = tmp->next)
2434     if (candidate_equal_p (tmp->expr, written))
2435       return;
2436
2437   while (list)
2438     {
2439       if (candidate_equal_p (list->expr, written)
2440           && !candidate_equal_p (list->writer, writer)
2441           && (!only_writes || list->writer))
2442         {
2443           warned_ids = new_tlist (warned_ids, written, NULL_TREE);
2444           warning_at (EXPR_HAS_LOCATION (writer)
2445                       ? EXPR_LOCATION (writer) : input_location,
2446                       OPT_Wsequence_point, "operation on %qE may be undefined",
2447                       list->expr);
2448         }
2449       list = list->next;
2450     }
2451 }
2452
2453 /* Given a list LIST of references to variables, find whether any of these
2454    can cause conflicts due to missing sequence points.  */
2455
2456 static void
2457 warn_for_collisions (struct tlist *list)
2458 {
2459   struct tlist *tmp;
2460
2461   for (tmp = list; tmp; tmp = tmp->next)
2462     {
2463       if (tmp->writer)
2464         warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0);
2465     }
2466 }
2467
2468 /* Return nonzero if X is a tree that can be verified by the sequence point
2469    warnings.  */
2470 static int
2471 warning_candidate_p (tree x)
2472 {
2473   /* !VOID_TYPE_P (TREE_TYPE (x)) is workaround for cp/tree.c
2474      (lvalue_p) crash on TRY/CATCH. */
2475   return !(DECL_P (x) && DECL_ARTIFICIAL (x))
2476     && TREE_TYPE (x) && !VOID_TYPE_P (TREE_TYPE (x)) && lvalue_p (x);
2477 }
2478
2479 /* Return nonzero if X and Y appear to be the same candidate (or NULL) */
2480 static bool
2481 candidate_equal_p (const_tree x, const_tree y)
2482 {
2483   return (x == y) || (x && y && operand_equal_p (x, y, 0));
2484 }
2485
2486 /* Walk the tree X, and record accesses to variables.  If X is written by the
2487    parent tree, WRITER is the parent.
2488    We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP.  If this
2489    expression or its only operand forces a sequence point, then everything up
2490    to the sequence point is stored in PBEFORE_SP.  Everything else gets stored
2491    in PNO_SP.
2492    Once we return, we will have emitted warnings if any subexpression before
2493    such a sequence point could be undefined.  On a higher level, however, the
2494    sequence point may not be relevant, and we'll merge the two lists.
2495
2496    Example: (b++, a) + b;
2497    The call that processes the COMPOUND_EXPR will store the increment of B
2498    in PBEFORE_SP, and the use of A in PNO_SP.  The higher-level call that
2499    processes the PLUS_EXPR will need to merge the two lists so that
2500    eventually, all accesses end up on the same list (and we'll warn about the
2501    unordered subexpressions b++ and b.
2502
2503    A note on merging.  If we modify the former example so that our expression
2504    becomes
2505      (b++, b) + a
2506    care must be taken not simply to add all three expressions into the final
2507    PNO_SP list.  The function merge_tlist takes care of that by merging the
2508    before-SP list of the COMPOUND_EXPR into its after-SP list in a special
2509    way, so that no more than one access to B is recorded.  */
2510
2511 static void
2512 verify_tree (tree x, struct tlist **pbefore_sp, struct tlist **pno_sp,
2513              tree writer)
2514 {
2515   struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3;
2516   enum tree_code code;
2517   enum tree_code_class cl;
2518
2519   /* X may be NULL if it is the operand of an empty statement expression
2520      ({ }).  */
2521   if (x == NULL)
2522     return;
2523
2524  restart:
2525   code = TREE_CODE (x);
2526   cl = TREE_CODE_CLASS (code);
2527
2528   if (warning_candidate_p (x))
2529     *pno_sp = new_tlist (*pno_sp, x, writer);
2530
2531   switch (code)
2532     {
2533     case CONSTRUCTOR:
2534       return;
2535
2536     case COMPOUND_EXPR:
2537     case TRUTH_ANDIF_EXPR:
2538     case TRUTH_ORIF_EXPR:
2539       tmp_before = tmp_nosp = tmp_list3 = 0;
2540       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
2541       warn_for_collisions (tmp_nosp);
2542       merge_tlist (pbefore_sp, tmp_before, 0);
2543       merge_tlist (pbefore_sp, tmp_nosp, 0);
2544       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE);
2545       merge_tlist (pbefore_sp, tmp_list3, 0);
2546       return;
2547
2548     case COND_EXPR:
2549       tmp_before = tmp_list2 = 0;
2550       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE);
2551       warn_for_collisions (tmp_list2);
2552       merge_tlist (pbefore_sp, tmp_before, 0);
2553       merge_tlist (pbefore_sp, tmp_list2, 1);
2554
2555       tmp_list3 = tmp_nosp = 0;
2556       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE);
2557       warn_for_collisions (tmp_nosp);
2558       merge_tlist (pbefore_sp, tmp_list3, 0);
2559
2560       tmp_list3 = tmp_list2 = 0;
2561       verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE);
2562       warn_for_collisions (tmp_list2);
2563       merge_tlist (pbefore_sp, tmp_list3, 0);
2564       /* Rather than add both tmp_nosp and tmp_list2, we have to merge the
2565          two first, to avoid warning for (a ? b++ : b++).  */
2566       merge_tlist (&tmp_nosp, tmp_list2, 0);
2567       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2568       return;
2569
2570     case PREDECREMENT_EXPR:
2571     case PREINCREMENT_EXPR:
2572     case POSTDECREMENT_EXPR:
2573     case POSTINCREMENT_EXPR:
2574       verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x);
2575       return;
2576
2577     case MODIFY_EXPR:
2578       tmp_before = tmp_nosp = tmp_list3 = 0;
2579       verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE);
2580       verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x);
2581       /* Expressions inside the LHS are not ordered wrt. the sequence points
2582          in the RHS.  Example:
2583            *a = (a++, 2)
2584          Despite the fact that the modification of "a" is in the before_sp
2585          list (tmp_before), it conflicts with the use of "a" in the LHS.
2586          We can handle this by adding the contents of tmp_list3
2587          to those of tmp_before, and redoing the collision warnings for that
2588          list.  */
2589       add_tlist (&tmp_before, tmp_list3, x, 1);
2590       warn_for_collisions (tmp_before);
2591       /* Exclude the LHS itself here; we first have to merge it into the
2592          tmp_nosp list.  This is done to avoid warning for "a = a"; if we
2593          didn't exclude the LHS, we'd get it twice, once as a read and once
2594          as a write.  */
2595       add_tlist (pno_sp, tmp_list3, x, 0);
2596       warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1);
2597
2598       merge_tlist (pbefore_sp, tmp_before, 0);
2599       if (warning_candidate_p (TREE_OPERAND (x, 0)))
2600         merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0);
2601       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1);
2602       return;
2603
2604     case CALL_EXPR:
2605       /* We need to warn about conflicts among arguments and conflicts between
2606          args and the function address.  Side effects of the function address,
2607          however, are not ordered by the sequence point of the call.  */
2608       {
2609         call_expr_arg_iterator iter;
2610         tree arg;
2611         tmp_before = tmp_nosp = 0;
2612         verify_tree (CALL_EXPR_FN (x), &tmp_before, &tmp_nosp, NULL_TREE);
2613         FOR_EACH_CALL_EXPR_ARG (arg, iter, x)
2614           {
2615             tmp_list2 = tmp_list3 = 0;
2616             verify_tree (arg, &tmp_list2, &tmp_list3, NULL_TREE);
2617             merge_tlist (&tmp_list3, tmp_list2, 0);
2618             add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0);
2619           }
2620         add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0);
2621         warn_for_collisions (tmp_before);
2622         add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0);
2623         return;
2624       }
2625
2626     case TREE_LIST:
2627       /* Scan all the list, e.g. indices of multi dimensional array.  */
2628       while (x)
2629         {
2630           tmp_before = tmp_nosp = 0;
2631           verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE);
2632           merge_tlist (&tmp_nosp, tmp_before, 0);
2633           add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2634           x = TREE_CHAIN (x);
2635         }
2636       return;
2637
2638     case SAVE_EXPR:
2639       {
2640         struct tlist_cache *t;
2641         for (t = save_expr_cache; t; t = t->next)
2642           if (candidate_equal_p (t->expr, x))
2643             break;
2644
2645         if (!t)
2646           {
2647             t = XOBNEW (&tlist_obstack, struct tlist_cache);
2648             t->next = save_expr_cache;
2649             t->expr = x;
2650             save_expr_cache = t;
2651
2652             tmp_before = tmp_nosp = 0;
2653             verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
2654             warn_for_collisions (tmp_nosp);
2655
2656             tmp_list3 = 0;
2657             while (tmp_nosp)
2658               {
2659                 struct tlist *t = tmp_nosp;
2660                 tmp_nosp = t->next;
2661                 merge_tlist (&tmp_list3, t, 0);
2662               }
2663             t->cache_before_sp = tmp_before;
2664             t->cache_after_sp = tmp_list3;
2665           }
2666         merge_tlist (pbefore_sp, t->cache_before_sp, 1);
2667         add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1);
2668         return;
2669       }
2670
2671     case ADDR_EXPR:
2672       x = TREE_OPERAND (x, 0);
2673       if (DECL_P (x))
2674         return;
2675       writer = 0;
2676       goto restart;
2677
2678     default:
2679       /* For other expressions, simply recurse on their operands.
2680          Manual tail recursion for unary expressions.
2681          Other non-expressions need not be processed.  */
2682       if (cl == tcc_unary)
2683         {
2684           x = TREE_OPERAND (x, 0);
2685           writer = 0;
2686           goto restart;
2687         }
2688       else if (IS_EXPR_CODE_CLASS (cl))
2689         {
2690           int lp;
2691           int max = TREE_OPERAND_LENGTH (x);
2692           for (lp = 0; lp < max; lp++)
2693             {
2694               tmp_before = tmp_nosp = 0;
2695               verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, 0);
2696               merge_tlist (&tmp_nosp, tmp_before, 0);
2697               add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2698             }
2699         }
2700       return;
2701     }
2702 }
2703
2704 /* Try to warn for undefined behavior in EXPR due to missing sequence
2705    points.  */
2706
2707 void
2708 verify_sequence_points (tree expr)
2709 {
2710   struct tlist *before_sp = 0, *after_sp = 0;
2711
2712   warned_ids = 0;
2713   save_expr_cache = 0;
2714   if (tlist_firstobj == 0)
2715     {
2716       gcc_obstack_init (&tlist_obstack);
2717       tlist_firstobj = (char *) obstack_alloc (&tlist_obstack, 0);
2718     }
2719
2720   verify_tree (expr, &before_sp, &after_sp, 0);
2721   warn_for_collisions (after_sp);
2722   obstack_free (&tlist_obstack, tlist_firstobj);
2723 }
2724 \f
2725 /* Validate the expression after `case' and apply default promotions.  */
2726
2727 static tree
2728 check_case_value (tree value)
2729 {
2730   if (value == NULL_TREE)
2731     return value;
2732
2733   /* ??? Can we ever get nops here for a valid case value?  We
2734      shouldn't for C.  */
2735   STRIP_TYPE_NOPS (value);
2736   /* In C++, the following is allowed:
2737
2738        const int i = 3;
2739        switch (...) { case i: ... }
2740
2741      So, we try to reduce the VALUE to a constant that way.  */
2742   if (c_dialect_cxx ())
2743     {
2744       value = decl_constant_value (value);
2745       STRIP_TYPE_NOPS (value);
2746       value = fold (value);
2747     }
2748
2749   if (TREE_CODE (value) == INTEGER_CST)
2750     /* Promote char or short to int.  */
2751     value = perform_integral_promotions (value);
2752   else if (value != error_mark_node)
2753     {
2754       error ("case label does not reduce to an integer constant");
2755       value = error_mark_node;
2756     }
2757
2758   constant_expression_warning (value);
2759
2760   return value;
2761 }
2762 \f
2763 /* See if the case values LOW and HIGH are in the range of the original
2764    type (i.e. before the default conversion to int) of the switch testing
2765    expression.
2766    TYPE is the promoted type of the testing expression, and ORIG_TYPE is
2767    the type before promoting it.  CASE_LOW_P is a pointer to the lower
2768    bound of the case label, and CASE_HIGH_P is the upper bound or NULL
2769    if the case is not a case range.
2770    The caller has to make sure that we are not called with NULL for
2771    CASE_LOW_P (i.e. the default case).
2772    Returns true if the case label is in range of ORIG_TYPE (saturated or
2773    untouched) or false if the label is out of range.  */
2774
2775 static bool
2776 check_case_bounds (tree type, tree orig_type,
2777                    tree *case_low_p, tree *case_high_p)
2778 {
2779   tree min_value, max_value;
2780   tree case_low = *case_low_p;
2781   tree case_high = case_high_p ? *case_high_p : case_low;
2782
2783   /* If there was a problem with the original type, do nothing.  */
2784   if (orig_type == error_mark_node)
2785     return true;
2786
2787   min_value = TYPE_MIN_VALUE (orig_type);
2788   max_value = TYPE_MAX_VALUE (orig_type);
2789
2790   /* Case label is less than minimum for type.  */
2791   if (tree_int_cst_compare (case_low, min_value) < 0
2792       && tree_int_cst_compare (case_high, min_value) < 0)
2793     {
2794       warning (0, "case label value is less than minimum value for type");
2795       return false;
2796     }
2797
2798   /* Case value is greater than maximum for type.  */
2799   if (tree_int_cst_compare (case_low, max_value) > 0
2800       && tree_int_cst_compare (case_high, max_value) > 0)
2801     {
2802       warning (0, "case label value exceeds maximum value for type");
2803       return false;
2804     }
2805
2806   /* Saturate lower case label value to minimum.  */
2807   if (tree_int_cst_compare (case_high, min_value) >= 0
2808       && tree_int_cst_compare (case_low, min_value) < 0)
2809     {
2810       warning (0, "lower value in case label range"
2811                " less than minimum value for type");
2812       case_low = min_value;
2813     }
2814
2815   /* Saturate upper case label value to maximum.  */
2816   if (tree_int_cst_compare (case_low, max_value) <= 0
2817       && tree_int_cst_compare (case_high, max_value) > 0)
2818     {
2819       warning (0, "upper value in case label range"
2820                " exceeds maximum value for type");
2821       case_high = max_value;
2822     }
2823
2824   if (*case_low_p != case_low)
2825     *case_low_p = convert (type, case_low);
2826   if (case_high_p && *case_high_p != case_high)
2827     *case_high_p = convert (type, case_high);
2828
2829   return true;
2830 }
2831 \f
2832 /* Return an integer type with BITS bits of precision,
2833    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
2834
2835 tree
2836 c_common_type_for_size (unsigned int bits, int unsignedp)
2837 {
2838   if (bits == TYPE_PRECISION (integer_type_node))
2839     return unsignedp ? unsigned_type_node : integer_type_node;
2840
2841   if (bits == TYPE_PRECISION (signed_char_type_node))
2842     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2843
2844   if (bits == TYPE_PRECISION (short_integer_type_node))
2845     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2846
2847   if (bits == TYPE_PRECISION (long_integer_type_node))
2848     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2849
2850   if (bits == TYPE_PRECISION (long_long_integer_type_node))
2851     return (unsignedp ? long_long_unsigned_type_node
2852             : long_long_integer_type_node);
2853
2854   if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
2855     return (unsignedp ? widest_unsigned_literal_type_node
2856             : widest_integer_literal_type_node);
2857
2858   if (bits <= TYPE_PRECISION (intQI_type_node))
2859     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2860
2861   if (bits <= TYPE_PRECISION (intHI_type_node))
2862     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2863
2864   if (bits <= TYPE_PRECISION (intSI_type_node))
2865     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2866
2867   if (bits <= TYPE_PRECISION (intDI_type_node))
2868     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2869
2870   return 0;
2871 }
2872
2873 /* Return a fixed-point type that has at least IBIT ibits and FBIT fbits
2874    that is unsigned if UNSIGNEDP is nonzero, otherwise signed;
2875    and saturating if SATP is nonzero, otherwise not saturating.  */
2876
2877 tree
2878 c_common_fixed_point_type_for_size (unsigned int ibit, unsigned int fbit,
2879                                     int unsignedp, int satp)
2880 {
2881   enum machine_mode mode;
2882   if (ibit == 0)
2883     mode = unsignedp ? UQQmode : QQmode;
2884   else
2885     mode = unsignedp ? UHAmode : HAmode;
2886
2887   for (; mode != VOIDmode; mode = GET_MODE_WIDER_MODE (mode))
2888     if (GET_MODE_IBIT (mode) >= ibit && GET_MODE_FBIT (mode) >= fbit)
2889       break;
2890
2891   if (mode == VOIDmode || !targetm.scalar_mode_supported_p (mode))
2892     {
2893       sorry ("GCC cannot support operators with integer types and "
2894              "fixed-point types that have too many integral and "
2895              "fractional bits together");
2896       return 0;
2897     }
2898
2899   return c_common_type_for_mode (mode, satp);
2900 }
2901
2902 /* Used for communication between c_common_type_for_mode and
2903    c_register_builtin_type.  */
2904 static GTY(()) tree registered_builtin_types;
2905
2906 /* Return a data type that has machine mode MODE.
2907    If the mode is an integer,
2908    then UNSIGNEDP selects between signed and unsigned types.
2909    If the mode is a fixed-point mode,
2910    then UNSIGNEDP selects between saturating and nonsaturating types.  */
2911
2912 tree
2913 c_common_type_for_mode (enum machine_mode mode, int unsignedp)
2914 {
2915   tree t;
2916
2917   if (mode == TYPE_MODE (integer_type_node))
2918     return unsignedp ? unsigned_type_node : integer_type_node;
2919
2920   if (mode == TYPE_MODE (signed_char_type_node))
2921     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2922
2923   if (mode == TYPE_MODE (short_integer_type_node))
2924     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2925
2926   if (mode == TYPE_MODE (long_integer_type_node))
2927     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2928
2929   if (mode == TYPE_MODE (long_long_integer_type_node))
2930     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
2931
2932   if (mode == TYPE_MODE (widest_integer_literal_type_node))
2933     return unsignedp ? widest_unsigned_literal_type_node
2934                      : widest_integer_literal_type_node;
2935
2936   if (mode == QImode)
2937     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2938
2939   if (mode == HImode)
2940     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2941
2942   if (mode == SImode)
2943     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2944
2945   if (mode == DImode)
2946     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2947
2948 #if HOST_BITS_PER_WIDE_INT >= 64
2949   if (mode == TYPE_MODE (intTI_type_node))
2950     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
2951 #endif
2952
2953   if (mode == TYPE_MODE (float_type_node))
2954     return float_type_node;
2955
2956   if (mode == TYPE_MODE (double_type_node))
2957     return double_type_node;
2958
2959   if (mode == TYPE_MODE (long_double_type_node))
2960     return long_double_type_node;
2961
2962   if (mode == TYPE_MODE (void_type_node))
2963     return void_type_node;
2964
2965   if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
2966     return (unsignedp
2967             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2968             : make_signed_type (GET_MODE_PRECISION (mode)));
2969
2970   if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
2971     return (unsignedp
2972             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2973             : make_signed_type (GET_MODE_PRECISION (mode)));
2974
2975   if (COMPLEX_MODE_P (mode))
2976     {
2977       enum machine_mode inner_mode;
2978       tree inner_type;
2979
2980       if (mode == TYPE_MODE (complex_float_type_node))
2981         return complex_float_type_node;
2982       if (mode == TYPE_MODE (complex_double_type_node))
2983         return complex_double_type_node;
2984       if (mode == TYPE_MODE (complex_long_double_type_node))
2985         return complex_long_double_type_node;
2986
2987       if (mode == TYPE_MODE (complex_integer_type_node) && !unsignedp)
2988         return complex_integer_type_node;
2989
2990       inner_mode = GET_MODE_INNER (mode);
2991       inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2992       if (inner_type != NULL_TREE)
2993         return build_complex_type (inner_type);
2994     }
2995   else if (VECTOR_MODE_P (mode))
2996     {
2997       enum machine_mode inner_mode = GET_MODE_INNER (mode);
2998       tree inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2999       if (inner_type != NULL_TREE)
3000         return build_vector_type_for_mode (inner_type, mode);
3001     }
3002
3003   if (mode == TYPE_MODE (dfloat32_type_node))
3004     return dfloat32_type_node;
3005   if (mode == TYPE_MODE (dfloat64_type_node))
3006     return dfloat64_type_node;
3007   if (mode == TYPE_MODE (dfloat128_type_node))
3008     return dfloat128_type_node;
3009
3010   if (ALL_SCALAR_FIXED_POINT_MODE_P (mode))
3011     {
3012       if (mode == TYPE_MODE (short_fract_type_node))
3013         return unsignedp ? sat_short_fract_type_node : short_fract_type_node;
3014       if (mode == TYPE_MODE (fract_type_node))
3015         return unsignedp ? sat_fract_type_node : fract_type_node;
3016       if (mode == TYPE_MODE (long_fract_type_node))
3017         return unsignedp ? sat_long_fract_type_node : long_fract_type_node;
3018       if (mode == TYPE_MODE (long_long_fract_type_node))
3019         return unsignedp ? sat_long_long_fract_type_node
3020                          : long_long_fract_type_node;
3021
3022       if (mode == TYPE_MODE (unsigned_short_fract_type_node))
3023         return unsignedp ? sat_unsigned_short_fract_type_node
3024                          : unsigned_short_fract_type_node;
3025       if (mode == TYPE_MODE (unsigned_fract_type_node))
3026         return unsignedp ? sat_unsigned_fract_type_node
3027                          : unsigned_fract_type_node;
3028       if (mode == TYPE_MODE (unsigned_long_fract_type_node))
3029         return unsignedp ? sat_unsigned_long_fract_type_node
3030                          : unsigned_long_fract_type_node;
3031       if (mode == TYPE_MODE (unsigned_long_long_fract_type_node))
3032         return unsignedp ? sat_unsigned_long_long_fract_type_node
3033                          : unsigned_long_long_fract_type_node;
3034
3035       if (mode == TYPE_MODE (short_accum_type_node))
3036         return unsignedp ? sat_short_accum_type_node : short_accum_type_node;
3037       if (mode == TYPE_MODE (accum_type_node))
3038         return unsignedp ? sat_accum_type_node : accum_type_node;
3039       if (mode == TYPE_MODE (long_accum_type_node))
3040         return unsignedp ? sat_long_accum_type_node : long_accum_type_node;
3041       if (mode == TYPE_MODE (long_long_accum_type_node))
3042         return unsignedp ? sat_long_long_accum_type_node
3043                          : long_long_accum_type_node;
3044
3045       if (mode == TYPE_MODE (unsigned_short_accum_type_node))
3046         return unsignedp ? sat_unsigned_short_accum_type_node
3047                          : unsigned_short_accum_type_node;
3048       if (mode == TYPE_MODE (unsigned_accum_type_node))
3049         return unsignedp ? sat_unsigned_accum_type_node
3050                          : unsigned_accum_type_node;
3051       if (mode == TYPE_MODE (unsigned_long_accum_type_node))
3052         return unsignedp ? sat_unsigned_long_accum_type_node
3053                          : unsigned_long_accum_type_node;
3054       if (mode == TYPE_MODE (unsigned_long_long_accum_type_node))
3055         return unsignedp ? sat_unsigned_long_long_accum_type_node
3056                          : unsigned_long_long_accum_type_node;
3057
3058       if (mode == QQmode)
3059         return unsignedp ? sat_qq_type_node : qq_type_node;
3060       if (mode == HQmode)
3061         return unsignedp ? sat_hq_type_node : hq_type_node;
3062       if (mode == SQmode)
3063         return unsignedp ? sat_sq_type_node : sq_type_node;
3064       if (mode == DQmode)
3065         return unsignedp ? sat_dq_type_node : dq_type_node;
3066       if (mode == TQmode)
3067         return unsignedp ? sat_tq_type_node : tq_type_node;
3068
3069       if (mode == UQQmode)
3070         return unsignedp ? sat_uqq_type_node : uqq_type_node;
3071       if (mode == UHQmode)
3072         return unsignedp ? sat_uhq_type_node : uhq_type_node;
3073       if (mode == USQmode)
3074         return unsignedp ? sat_usq_type_node : usq_type_node;
3075       if (mode == UDQmode)
3076         return unsignedp ? sat_udq_type_node : udq_type_node;
3077       if (mode == UTQmode)
3078         return unsignedp ? sat_utq_type_node : utq_type_node;
3079
3080       if (mode == HAmode)
3081         return unsignedp ? sat_ha_type_node : ha_type_node;
3082       if (mode == SAmode)
3083         return unsignedp ? sat_sa_type_node : sa_type_node;
3084       if (mode == DAmode)
3085         return unsignedp ? sat_da_type_node : da_type_node;
3086       if (mode == TAmode)
3087         return unsignedp ? sat_ta_type_node : ta_type_node;
3088
3089       if (mode == UHAmode)
3090         return unsignedp ? sat_uha_type_node : uha_type_node;
3091       if (mode == USAmode)
3092         return unsignedp ? sat_usa_type_node : usa_type_node;
3093       if (mode == UDAmode)
3094         return unsignedp ? sat_uda_type_node : uda_type_node;
3095       if (mode == UTAmode)
3096         return unsignedp ? sat_uta_type_node : uta_type_node;
3097     }
3098
3099   for (t = registered_builtin_types; t; t = TREE_CHAIN (t))
3100     if (TYPE_MODE (TREE_VALUE (t)) == mode)
3101       return TREE_VALUE (t);
3102
3103   return 0;
3104 }
3105
3106 tree
3107 c_common_unsigned_type (tree type)
3108 {
3109   return c_common_signed_or_unsigned_type (1, type);
3110 }
3111
3112 /* Return a signed type the same as TYPE in other respects.  */
3113
3114 tree
3115 c_common_signed_type (tree type)
3116 {
3117   return c_common_signed_or_unsigned_type (0, type);
3118 }
3119
3120 /* Return a type the same as TYPE except unsigned or
3121    signed according to UNSIGNEDP.  */
3122
3123 tree
3124 c_common_signed_or_unsigned_type (int unsignedp, tree type)
3125 {
3126   tree type1;
3127
3128   /* This block of code emulates the behavior of the old
3129      c_common_unsigned_type. In particular, it returns
3130      long_unsigned_type_node if passed a long, even when a int would
3131      have the same size. This is necessary for warnings to work
3132      correctly in archs where sizeof(int) == sizeof(long) */
3133
3134   type1 = TYPE_MAIN_VARIANT (type);
3135   if (type1 == signed_char_type_node || type1 == char_type_node || type1 == unsigned_char_type_node)
3136     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3137   if (type1 == integer_type_node || type1 == unsigned_type_node)
3138     return unsignedp ? unsigned_type_node : integer_type_node;
3139   if (type1 == short_integer_type_node || type1 == short_unsigned_type_node)
3140     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3141   if (type1 == long_integer_type_node || type1 == long_unsigned_type_node)
3142     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3143   if (type1 == long_long_integer_type_node || type1 == long_long_unsigned_type_node)
3144     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
3145   if (type1 == widest_integer_literal_type_node || type1 == widest_unsigned_literal_type_node)
3146     return unsignedp ? widest_unsigned_literal_type_node : widest_integer_literal_type_node;
3147 #if HOST_BITS_PER_WIDE_INT >= 64
3148   if (type1 == intTI_type_node || type1 == unsigned_intTI_type_node)
3149     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
3150 #endif
3151   if (type1 == intDI_type_node || type1 == unsigned_intDI_type_node)
3152     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
3153   if (type1 == intSI_type_node || type1 == unsigned_intSI_type_node)
3154     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
3155   if (type1 == intHI_type_node || type1 == unsigned_intHI_type_node)
3156     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
3157   if (type1 == intQI_type_node || type1 == unsigned_intQI_type_node)
3158     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
3159
3160 #define C_COMMON_FIXED_TYPES(NAME)          \
3161   if (type1 == short_ ## NAME ## _type_node \
3162       || type1 == unsigned_short_ ## NAME ## _type_node) \
3163     return unsignedp ? unsigned_short_ ## NAME ## _type_node \
3164                      : short_ ## NAME ## _type_node; \
3165   if (type1 == NAME ## _type_node \
3166       || type1 == unsigned_ ## NAME ## _type_node) \
3167     return unsignedp ? unsigned_ ## NAME ## _type_node \
3168                      : NAME ## _type_node; \
3169   if (type1 == long_ ## NAME ## _type_node \
3170       || type1 == unsigned_long_ ## NAME ## _type_node) \
3171     return unsignedp ? unsigned_long_ ## NAME ## _type_node \
3172                      : long_ ## NAME ## _type_node; \
3173   if (type1 == long_long_ ## NAME ## _type_node \
3174       || type1 == unsigned_long_long_ ## NAME ## _type_node) \
3175     return unsignedp ? unsigned_long_long_ ## NAME ## _type_node \
3176                      : long_long_ ## NAME ## _type_node;
3177
3178 #define C_COMMON_FIXED_MODE_TYPES(NAME) \
3179   if (type1 == NAME ## _type_node \
3180       || type1 == u ## NAME ## _type_node) \
3181     return unsignedp ? u ## NAME ## _type_node \
3182                      : NAME ## _type_node;
3183
3184 #define C_COMMON_FIXED_TYPES_SAT(NAME) \
3185   if (type1 == sat_ ## short_ ## NAME ## _type_node \
3186       || type1 == sat_ ## unsigned_short_ ## NAME ## _type_node) \
3187     return unsignedp ? sat_ ## unsigned_short_ ## NAME ## _type_node \
3188                      : sat_ ## short_ ## NAME ## _type_node; \
3189   if (type1 == sat_ ## NAME ## _type_node \
3190       || type1 == sat_ ## unsigned_ ## NAME ## _type_node) \
3191     return unsignedp ? sat_ ## unsigned_ ## NAME ## _type_node \
3192                      : sat_ ## NAME ## _type_node; \
3193   if (type1 == sat_ ## long_ ## NAME ## _type_node \
3194       || type1 == sat_ ## unsigned_long_ ## NAME ## _type_node) \
3195     return unsignedp ? sat_ ## unsigned_long_ ## NAME ## _type_node \
3196                      : sat_ ## long_ ## NAME ## _type_node; \
3197   if (type1 == sat_ ## long_long_ ## NAME ## _type_node \
3198       || type1 == sat_ ## unsigned_long_long_ ## NAME ## _type_node) \
3199     return unsignedp ? sat_ ## unsigned_long_long_ ## NAME ## _type_node \
3200                      : sat_ ## long_long_ ## NAME ## _type_node;
3201
3202 #define C_COMMON_FIXED_MODE_TYPES_SAT(NAME)     \
3203   if (type1 == sat_ ## NAME ## _type_node \
3204       || type1 == sat_ ## u ## NAME ## _type_node) \
3205     return unsignedp ? sat_ ## u ## NAME ## _type_node \
3206                      : sat_ ## NAME ## _type_node;
3207
3208   C_COMMON_FIXED_TYPES (fract);
3209   C_COMMON_FIXED_TYPES_SAT (fract);
3210   C_COMMON_FIXED_TYPES (accum);
3211   C_COMMON_FIXED_TYPES_SAT (accum);
3212
3213   C_COMMON_FIXED_MODE_TYPES (qq);
3214   C_COMMON_FIXED_MODE_TYPES (hq);
3215   C_COMMON_FIXED_MODE_TYPES (sq);
3216   C_COMMON_FIXED_MODE_TYPES (dq);
3217   C_COMMON_FIXED_MODE_TYPES (tq);
3218   C_COMMON_FIXED_MODE_TYPES_SAT (qq);
3219   C_COMMON_FIXED_MODE_TYPES_SAT (hq);
3220   C_COMMON_FIXED_MODE_TYPES_SAT (sq);
3221   C_COMMON_FIXED_MODE_TYPES_SAT (dq);
3222   C_COMMON_FIXED_MODE_TYPES_SAT (tq);
3223   C_COMMON_FIXED_MODE_TYPES (ha);
3224   C_COMMON_FIXED_MODE_TYPES (sa);
3225   C_COMMON_FIXED_MODE_TYPES (da);
3226   C_COMMON_FIXED_MODE_TYPES (ta);
3227   C_COMMON_FIXED_MODE_TYPES_SAT (ha);
3228   C_COMMON_FIXED_MODE_TYPES_SAT (sa);
3229   C_COMMON_FIXED_MODE_TYPES_SAT (da);
3230   C_COMMON_FIXED_MODE_TYPES_SAT (ta);
3231
3232   /* For ENUMERAL_TYPEs in C++, must check the mode of the types, not
3233      the precision; they have precision set to match their range, but
3234      may use a wider mode to match an ABI.  If we change modes, we may
3235      wind up with bad conversions.  For INTEGER_TYPEs in C, must check
3236      the precision as well, so as to yield correct results for
3237      bit-field types.  C++ does not have these separate bit-field
3238      types, and producing a signed or unsigned variant of an
3239      ENUMERAL_TYPE may cause other problems as well.  */
3240
3241   if (!INTEGRAL_TYPE_P (type)
3242       || TYPE_UNSIGNED (type) == unsignedp)
3243     return type;
3244
3245 #define TYPE_OK(node)                                                       \
3246   (TYPE_MODE (type) == TYPE_MODE (node)                                     \
3247    && TYPE_PRECISION (type) == TYPE_PRECISION (node))
3248   if (TYPE_OK (signed_char_type_node))
3249     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3250   if (TYPE_OK (integer_type_node))
3251     return unsignedp ? unsigned_type_node : integer_type_node;
3252   if (TYPE_OK (short_integer_type_node))
3253     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3254   if (TYPE_OK (long_integer_type_node))
3255     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3256   if (TYPE_OK (long_long_integer_type_node))
3257     return (unsignedp ? long_long_unsigned_type_node
3258             : long_long_integer_type_node);
3259   if (TYPE_OK (widest_integer_literal_type_node))
3260     return (unsignedp ? widest_unsigned_literal_type_node
3261             : widest_integer_literal_type_node);
3262
3263 #if HOST_BITS_PER_WIDE_INT >= 64
3264   if (TYPE_OK (intTI_type_node))
3265     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
3266 #endif
3267   if (TYPE_OK (intDI_type_node))
3268     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
3269   if (TYPE_OK (intSI_type_node))
3270     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
3271   if (TYPE_OK (intHI_type_node))
3272     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
3273   if (TYPE_OK (intQI_type_node))
3274     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
3275 #undef TYPE_OK
3276
3277   return build_nonstandard_integer_type (TYPE_PRECISION (type), unsignedp);
3278 }
3279
3280 /* Build a bit-field integer type for the given WIDTH and UNSIGNEDP.  */
3281
3282 tree
3283 c_build_bitfield_integer_type (unsigned HOST_WIDE_INT width, int unsignedp)
3284 {
3285   /* Extended integer types of the same width as a standard type have
3286      lesser rank, so those of the same width as int promote to int or
3287      unsigned int and are valid for printf formats expecting int or
3288      unsigned int.  To avoid such special cases, avoid creating
3289      extended integer types for bit-fields if a standard integer type
3290      is available.  */
3291   if (width == TYPE_PRECISION (integer_type_node))
3292     return unsignedp ? unsigned_type_node : integer_type_node;
3293   if (width == TYPE_PRECISION (signed_char_type_node))
3294     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3295   if (width == TYPE_PRECISION (short_integer_type_node))
3296     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3297   if (width == TYPE_PRECISION (long_integer_type_node))
3298     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3299   if (width == TYPE_PRECISION (long_long_integer_type_node))
3300     return (unsignedp ? long_long_unsigned_type_node
3301             : long_long_integer_type_node);
3302   return build_nonstandard_integer_type (width, unsignedp);
3303 }
3304
3305 /* The C version of the register_builtin_type langhook.  */
3306
3307 void
3308 c_register_builtin_type (tree type, const char* name)
3309 {
3310   tree decl;
3311
3312   decl = build_decl (UNKNOWN_LOCATION,
3313                      TYPE_DECL, get_identifier (name), type);
3314   DECL_ARTIFICIAL (decl) = 1;
3315   if (!TYPE_NAME (type))
3316     TYPE_NAME (type) = decl;
3317   pushdecl (decl);
3318
3319   registered_builtin_types = tree_cons (0, type, registered_builtin_types);
3320 }
3321 \f
3322 /* Print an error message for invalid operands to arith operation
3323    CODE with TYPE0 for operand 0, and TYPE1 for operand 1.
3324    LOCATION is the location of the message.  */
3325
3326 void
3327 binary_op_error (location_t location, enum tree_code code,
3328                  tree type0, tree type1)
3329 {
3330   const char *opname;
3331
3332   switch (code)
3333     {
3334     case PLUS_EXPR:
3335       opname = "+"; break;
3336     case MINUS_EXPR:
3337       opname = "-"; break;
3338     case MULT_EXPR:
3339       opname = "*"; break;
3340     case MAX_EXPR:
3341       opname = "max"; break;
3342     case MIN_EXPR:
3343       opname = "min"; break;
3344     case EQ_EXPR:
3345       opname = "=="; break;
3346     case NE_EXPR:
3347       opname = "!="; break;
3348     case LE_EXPR:
3349       opname = "<="; break;
3350     case GE_EXPR:
3351       opname = ">="; break;
3352     case LT_EXPR:
3353       opname = "<"; break;
3354     case GT_EXPR:
3355       opname = ">"; break;
3356     case LSHIFT_EXPR:
3357       opname = "<<"; break;
3358     case RSHIFT_EXPR:
3359       opname = ">>"; break;
3360     case TRUNC_MOD_EXPR:
3361     case FLOOR_MOD_EXPR:
3362       opname = "%"; break;
3363     case TRUNC_DIV_EXPR:
3364     case FLOOR_DIV_EXPR:
3365       opname = "/"; break;
3366     case BIT_AND_EXPR:
3367       opname = "&"; break;
3368     case BIT_IOR_EXPR:
3369       opname = "|"; break;
3370     case TRUTH_ANDIF_EXPR:
3371       opname = "&&"; break;
3372     case TRUTH_ORIF_EXPR:
3373       opname = "||"; break;
3374     case BIT_XOR_EXPR:
3375       opname = "^"; break;
3376     default:
3377       gcc_unreachable ();
3378     }
3379   error_at (location,
3380             "invalid operands to binary %s (have %qT and %qT)", opname,
3381             type0, type1);
3382 }
3383 \f
3384 /* Subroutine of build_binary_op, used for comparison operations.
3385    See if the operands have both been converted from subword integer types
3386    and, if so, perhaps change them both back to their original type.
3387    This function is also responsible for converting the two operands
3388    to the proper common type for comparison.
3389
3390    The arguments of this function are all pointers to local variables
3391    of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
3392    RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.
3393
3394    If this function returns nonzero, it means that the comparison has
3395    a constant value.  What this function returns is an expression for
3396    that value.  */
3397
3398 tree
3399 shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr,
3400                  enum tree_code *rescode_ptr)
3401 {
3402   tree type;
3403   tree op0 = *op0_ptr;
3404   tree op1 = *op1_ptr;
3405   int unsignedp0, unsignedp1;
3406   int real1, real2;
3407   tree primop0, primop1;
3408   enum tree_code code = *rescode_ptr;
3409
3410   /* Throw away any conversions to wider types
3411      already present in the operands.  */
3412
3413   primop0 = get_narrower (op0, &unsignedp0);
3414   primop1 = get_narrower (op1, &unsignedp1);
3415
3416   /* Handle the case that OP0 does not *contain* a conversion
3417      but it *requires* conversion to FINAL_TYPE.  */
3418
3419   if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
3420     unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3421   if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
3422     unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3423
3424   /* If one of the operands must be floated, we cannot optimize.  */
3425   real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
3426   real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
3427
3428   /* If first arg is constant, swap the args (changing operation
3429      so value is preserved), for canonicalization.  Don't do this if
3430      the second arg is 0.  */
3431
3432   if (TREE_CONSTANT (primop0)
3433       && !integer_zerop (primop1) && !real_zerop (primop1)
3434       && !fixed_zerop (primop1))
3435     {
3436       tree tem = primop0;
3437       int temi = unsignedp0;
3438       primop0 = primop1;
3439       primop1 = tem;
3440       tem = op0;
3441       op0 = op1;
3442       op1 = tem;
3443       *op0_ptr = op0;
3444       *op1_ptr = op1;
3445       unsignedp0 = unsignedp1;
3446       unsignedp1 = temi;
3447       temi = real1;
3448       real1 = real2;
3449       real2 = temi;
3450
3451       switch (code)
3452         {
3453         case LT_EXPR:
3454           code = GT_EXPR;
3455           break;
3456         case GT_EXPR:
3457           code = LT_EXPR;
3458           break;
3459         case LE_EXPR:
3460           code = GE_EXPR;
3461           break;
3462         case GE_EXPR:
3463           code = LE_EXPR;
3464           break;
3465         default:
3466           break;
3467         }
3468       *rescode_ptr = code;
3469     }
3470
3471   /* If comparing an integer against a constant more bits wide,
3472      maybe we can deduce a value of 1 or 0 independent of the data.
3473      Or else truncate the constant now
3474      rather than extend the variable at run time.
3475
3476      This is only interesting if the constant is the wider arg.
3477      Also, it is not safe if the constant is unsigned and the
3478      variable arg is signed, since in this case the variable
3479      would be sign-extended and then regarded as unsigned.
3480      Our technique fails in this case because the lowest/highest
3481      possible unsigned results don't follow naturally from the
3482      lowest/highest possible values of the variable operand.
3483      For just EQ_EXPR and NE_EXPR there is another technique that
3484      could be used: see if the constant can be faithfully represented
3485      in the other operand's type, by truncating it and reextending it
3486      and see if that preserves the constant's value.  */
3487
3488   if (!real1 && !real2
3489       && TREE_CODE (TREE_TYPE (primop0)) != FIXED_POINT_TYPE
3490       && TREE_CODE (primop1) == INTEGER_CST
3491       && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
3492     {
3493       int min_gt, max_gt, min_lt, max_lt;
3494       tree maxval, minval;
3495       /* 1 if comparison is nominally unsigned.  */
3496       int unsignedp = TYPE_UNSIGNED (*restype_ptr);
3497       tree val;
3498
3499       type = c_common_signed_or_unsigned_type (unsignedp0,
3500                                                TREE_TYPE (primop0));
3501
3502       maxval = TYPE_MAX_VALUE (type);
3503       minval = TYPE_MIN_VALUE (type);
3504
3505       if (unsignedp && !unsignedp0)
3506         *restype_ptr = c_common_signed_type (*restype_ptr);
3507
3508       if (TREE_TYPE (primop1) != *restype_ptr)
3509         {
3510           /* Convert primop1 to target type, but do not introduce
3511              additional overflow.  We know primop1 is an int_cst.  */
3512           primop1 = force_fit_type_double (*restype_ptr,
3513                                            TREE_INT_CST_LOW (primop1),
3514                                            TREE_INT_CST_HIGH (primop1), 0,
3515                                            TREE_OVERFLOW (primop1));
3516         }
3517       if (type != *restype_ptr)
3518         {
3519           minval = convert (*restype_ptr, minval);
3520           maxval = convert (*restype_ptr, maxval);
3521         }
3522
3523       if (unsignedp && unsignedp0)
3524         {
3525           min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
3526           max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
3527           min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
3528           max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
3529         }
3530       else
3531         {
3532           min_gt = INT_CST_LT (primop1, minval);
3533           max_gt = INT_CST_LT (primop1, maxval);
3534           min_lt = INT_CST_LT (minval, primop1);
3535           max_lt = INT_CST_LT (maxval, primop1);
3536         }
3537
3538       val = 0;
3539       /* This used to be a switch, but Genix compiler can't handle that.  */
3540       if (code == NE_EXPR)
3541         {
3542           if (max_lt || min_gt)
3543             val = truthvalue_true_node;
3544         }
3545       else if (code == EQ_EXPR)
3546         {
3547           if (max_lt || min_gt)
3548             val = truthvalue_false_node;
3549         }
3550       else if (code == LT_EXPR)
3551         {
3552           if (max_lt)
3553             val = truthvalue_true_node;
3554           if (!min_lt)
3555             val = truthvalue_false_node;
3556         }
3557       else if (code == GT_EXPR)
3558         {
3559           if (min_gt)
3560             val = truthvalue_true_node;
3561           if (!max_gt)
3562             val = truthvalue_false_node;
3563         }
3564       else if (code == LE_EXPR)
3565         {
3566           if (!max_gt)
3567             val = truthvalue_true_node;
3568           if (min_gt)
3569             val = truthvalue_false_node;
3570         }
3571       else if (code == GE_EXPR)
3572         {
3573           if (!min_lt)
3574             val = truthvalue_true_node;
3575           if (max_lt)
3576             val = truthvalue_false_node;
3577         }
3578
3579       /* If primop0 was sign-extended and unsigned comparison specd,
3580          we did a signed comparison above using the signed type bounds.
3581          But the comparison we output must be unsigned.
3582
3583          Also, for inequalities, VAL is no good; but if the signed
3584          comparison had *any* fixed result, it follows that the
3585          unsigned comparison just tests the sign in reverse
3586          (positive values are LE, negative ones GE).
3587          So we can generate an unsigned comparison
3588          against an extreme value of the signed type.  */
3589
3590       if (unsignedp && !unsignedp0)
3591         {
3592           if (val != 0)
3593             switch (code)
3594               {
3595               case LT_EXPR:
3596               case GE_EXPR:
3597                 primop1 = TYPE_MIN_VALUE (type);
3598                 val = 0;
3599                 break;
3600
3601               case LE_EXPR:
3602               case GT_EXPR:
3603                 primop1 = TYPE_MAX_VALUE (type);
3604                 val = 0;
3605                 break;
3606
3607               default:
3608                 break;
3609               }
3610           type = c_common_unsigned_type (type);
3611         }
3612
3613       if (TREE_CODE (primop0) != INTEGER_CST)
3614         {
3615           if (val == truthvalue_false_node)
3616             warning (OPT_Wtype_limits, "comparison is always false due to limited range of data type");
3617           if (val == truthvalue_true_node)
3618             warning (OPT_Wtype_limits, "comparison is always true due to limited range of data type");
3619         }
3620
3621       if (val != 0)
3622         {
3623           /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
3624           if (TREE_SIDE_EFFECTS (primop0))
3625             return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
3626           return val;
3627         }
3628
3629       /* Value is not predetermined, but do the comparison
3630          in the type of the operand that is not constant.
3631          TYPE is already properly set.  */
3632     }
3633
3634   /* If either arg is decimal float and the other is float, find the
3635      proper common type to use for comparison.  */
3636   else if (real1 && real2
3637            && (DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop0)))
3638                || DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop1)))))
3639     type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
3640
3641   else if (real1 && real2
3642            && (TYPE_PRECISION (TREE_TYPE (primop0))
3643                == TYPE_PRECISION (TREE_TYPE (primop1))))
3644     type = TREE_TYPE (primop0);
3645
3646   /* If args' natural types are both narrower than nominal type
3647      and both extend in the same manner, compare them
3648      in the type of the wider arg.
3649      Otherwise must actually extend both to the nominal
3650      common type lest different ways of extending
3651      alter the result.
3652      (eg, (short)-1 == (unsigned short)-1  should be 0.)  */
3653
3654   else if (unsignedp0 == unsignedp1 && real1 == real2
3655            && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
3656            && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
3657     {
3658       type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
3659       type = c_common_signed_or_unsigned_type (unsignedp0
3660                                                || TYPE_UNSIGNED (*restype_ptr),
3661                                                type);
3662       /* Make sure shorter operand is extended the right way
3663          to match the longer operand.  */
3664       primop0
3665         = convert (c_common_signed_or_unsigned_type (unsignedp0,
3666                                                      TREE_TYPE (primop0)),
3667                    primop0);
3668       primop1
3669         = convert (c_common_signed_or_unsigned_type (unsignedp1,
3670                                                      TREE_TYPE (primop1)),
3671                    primop1);
3672     }
3673   else
3674     {
3675       /* Here we must do the comparison on the nominal type
3676          using the args exactly as we received them.  */
3677       type = *restype_ptr;
3678       primop0 = op0;
3679       primop1 = op1;
3680
3681       if (!real1 && !real2 && integer_zerop (primop1)
3682           && TYPE_UNSIGNED (*restype_ptr))
3683         {
3684           tree value = 0;
3685           switch (code)
3686             {
3687             case GE_EXPR:
3688               /* All unsigned values are >= 0, so we warn.  However,
3689                  if OP0 is a constant that is >= 0, the signedness of
3690                  the comparison isn't an issue, so suppress the
3691                  warning.  */
3692               if (warn_type_limits && !in_system_header
3693                   && !(TREE_CODE (primop0) == INTEGER_CST
3694                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
3695                                                    primop0))))
3696                 warning (OPT_Wtype_limits,
3697                          "comparison of unsigned expression >= 0 is always true");
3698               value = truthvalue_true_node;
3699               break;
3700
3701             case LT_EXPR:
3702               if (warn_type_limits && !in_system_header
3703                   && !(TREE_CODE (primop0) == INTEGER_CST
3704                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
3705                                                    primop0))))
3706                 warning (OPT_Wtype_limits,
3707                          "comparison of unsigned expression < 0 is always false");
3708               value = truthvalue_false_node;
3709               break;
3710
3711             default:
3712               break;
3713             }
3714
3715           if (value != 0)
3716             {
3717               /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
3718               if (TREE_SIDE_EFFECTS (primop0))
3719                 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
3720                                primop0, value);
3721               return value;
3722             }
3723         }
3724     }
3725
3726   *op0_ptr = convert (type, primop0);
3727   *op1_ptr = convert (type, primop1);
3728
3729   *restype_ptr = truthvalue_type_node;
3730
3731   return 0;
3732 }
3733 \f
3734 /* Return a tree for the sum or difference (RESULTCODE says which)
3735    of pointer PTROP and integer INTOP.  */
3736
3737 tree
3738 pointer_int_sum (location_t loc, enum tree_code resultcode,
3739                  tree ptrop, tree intop)
3740 {
3741   tree size_exp, ret;
3742
3743   /* The result is a pointer of the same type that is being added.  */
3744   tree result_type = TREE_TYPE (ptrop);
3745
3746   if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
3747     {
3748       pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3749                "pointer of type %<void *%> used in arithmetic");
3750       size_exp = integer_one_node;
3751     }
3752   else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE)
3753     {
3754       pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3755                "pointer to a function used in arithmetic");
3756       size_exp = integer_one_node;
3757     }
3758   else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE)
3759     {
3760       pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3761                "pointer to member function used in arithmetic");
3762       size_exp = integer_one_node;
3763     }
3764   else
3765     size_exp = size_in_bytes (TREE_TYPE (result_type));
3766
3767   /* We are manipulating pointer values, so we don't need to warn
3768      about relying on undefined signed overflow.  We disable the
3769      warning here because we use integer types so fold won't know that
3770      they are really pointers.  */
3771   fold_defer_overflow_warnings ();
3772
3773   /* If what we are about to multiply by the size of the elements
3774      contains a constant term, apply distributive law
3775      and multiply that constant term separately.
3776      This helps produce common subexpressions.  */
3777   if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
3778       && !TREE_CONSTANT (intop)
3779       && TREE_CONSTANT (TREE_OPERAND (intop, 1))
3780       && TREE_CONSTANT (size_exp)
3781       /* If the constant comes from pointer subtraction,
3782          skip this optimization--it would cause an error.  */
3783       && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
3784       /* If the constant is unsigned, and smaller than the pointer size,
3785          then we must skip this optimization.  This is because it could cause
3786          an overflow error if the constant is negative but INTOP is not.  */
3787       && (!TYPE_UNSIGNED (TREE_TYPE (intop))
3788           || (TYPE_PRECISION (TREE_TYPE (intop))
3789               == TYPE_PRECISION (TREE_TYPE (ptrop)))))
3790     {
3791       enum tree_code subcode = resultcode;
3792       tree int_type = TREE_TYPE (intop);
3793       if (TREE_CODE (intop) == MINUS_EXPR)
3794         subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
3795       /* Convert both subexpression types to the type of intop,
3796          because weird cases involving pointer arithmetic
3797          can result in a sum or difference with different type args.  */
3798       ptrop = build_binary_op (EXPR_LOCATION (TREE_OPERAND (intop, 1)),
3799                                subcode, ptrop,
3800                                convert (int_type, TREE_OPERAND (intop, 1)), 1);
3801       intop = convert (int_type, TREE_OPERAND (intop, 0));
3802     }
3803
3804   /* Convert the integer argument to a type the same size as sizetype
3805      so the multiply won't overflow spuriously.  */
3806   if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype)
3807       || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype))
3808     intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype),
3809                                              TYPE_UNSIGNED (sizetype)), intop);
3810
3811   /* Replace the integer argument with a suitable product by the object size.
3812      Do this multiplication as signed, then convert to the appropriate
3813      type for the pointer operation.  */
3814   intop = convert (sizetype,
3815                    build_binary_op (loc,
3816                                     MULT_EXPR, intop,
3817                                     convert (TREE_TYPE (intop), size_exp), 1));
3818
3819   /* Create the sum or difference.  */
3820   if (resultcode == MINUS_EXPR)
3821     intop = fold_build1_loc (loc, NEGATE_EXPR, sizetype, intop);
3822
3823   ret = fold_build2_loc (loc, POINTER_PLUS_EXPR, result_type, ptrop, intop);
3824
3825   fold_undefer_and_ignore_overflow_warnings ();
3826
3827   return ret;
3828 }
3829 \f
3830 /* Wrap a C_MAYBE_CONST_EXPR around an expression that is fully folded
3831    and if NON_CONST is known not to be permitted in an evaluated part
3832    of a constant expression.  */
3833
3834 tree
3835 c_wrap_maybe_const (tree expr, bool non_const)
3836 {
3837   bool nowarning = TREE_NO_WARNING (expr);
3838   location_t loc = EXPR_LOCATION (expr);
3839
3840   /* This should never be called for C++.  */
3841   if (c_dialect_cxx ())
3842     gcc_unreachable ();
3843
3844   /* The result of folding may have a NOP_EXPR to set TREE_NO_WARNING.  */
3845   STRIP_TYPE_NOPS (expr);
3846   expr = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (expr), NULL, expr);
3847   C_MAYBE_CONST_EXPR_NON_CONST (expr) = non_const;
3848   if (nowarning)
3849     TREE_NO_WARNING (expr) = 1;
3850   protected_set_expr_location (expr, loc);
3851
3852   return expr;
3853 }
3854
3855 /* Wrap a SAVE_EXPR around EXPR, if appropriate.  Like save_expr, but
3856    for C folds the inside expression and wraps a C_MAYBE_CONST_EXPR
3857    around the SAVE_EXPR if needed so that c_fully_fold does not need
3858    to look inside SAVE_EXPRs.  */
3859
3860 tree
3861 c_save_expr (tree expr)
3862 {
3863   bool maybe_const = true;
3864   if (c_dialect_cxx ())
3865     return save_expr (expr);
3866   expr = c_fully_fold (expr, false, &maybe_const);
3867   expr = save_expr (expr);
3868   if (!maybe_const)
3869     expr = c_wrap_maybe_const (expr, true);
3870   return expr;
3871 }
3872
3873 /* Return whether EXPR is a declaration whose address can never be
3874    NULL.  */
3875
3876 bool
3877 decl_with_nonnull_addr_p (const_tree expr)
3878 {
3879   return (DECL_P (expr)
3880           && (TREE_CODE (expr) == PARM_DECL
3881               || TREE_CODE (expr) == LABEL_DECL
3882               || !DECL_WEAK (expr)));
3883 }
3884
3885 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
3886    or for an `if' or `while' statement or ?..: exp.  It should already
3887    have been validated to be of suitable type; otherwise, a bad
3888    diagnostic may result.
3889
3890    The EXPR is located at LOCATION.
3891
3892    This preparation consists of taking the ordinary
3893    representation of an expression expr and producing a valid tree
3894    boolean expression describing whether expr is nonzero.  We could
3895    simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1),
3896    but we optimize comparisons, &&, ||, and !.
3897
3898    The resulting type should always be `truthvalue_type_node'.  */
3899
3900 tree
3901 c_common_truthvalue_conversion (location_t location, tree expr)
3902 {
3903   switch (TREE_CODE (expr))
3904     {
3905     case EQ_EXPR:   case NE_EXPR:   case UNEQ_EXPR: case LTGT_EXPR:
3906     case LE_EXPR:   case GE_EXPR:   case LT_EXPR:   case GT_EXPR:
3907     case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR:
3908     case ORDERED_EXPR: case UNORDERED_EXPR:
3909       if (TREE_TYPE (expr) == truthvalue_type_node)
3910         return expr;
3911       expr = build2 (TREE_CODE (expr), truthvalue_type_node,
3912                      TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1));
3913       goto ret;
3914
3915     case TRUTH_ANDIF_EXPR:
3916     case TRUTH_ORIF_EXPR:
3917     case TRUTH_AND_EXPR:
3918     case TRUTH_OR_EXPR:
3919     case TRUTH_XOR_EXPR:
3920       if (TREE_TYPE (expr) == truthvalue_type_node)
3921         return expr;
3922       expr = build2 (TREE_CODE (expr), truthvalue_type_node,
3923                      c_common_truthvalue_conversion (location,
3924                                                      TREE_OPERAND (expr, 0)),
3925                      c_common_truthvalue_conversion (location,
3926                                                      TREE_OPERAND (expr, 1)));
3927       goto ret;
3928
3929     case TRUTH_NOT_EXPR:
3930       if (TREE_TYPE (expr) == truthvalue_type_node)
3931         return expr;
3932       expr = build1 (TREE_CODE (expr), truthvalue_type_node,
3933                      c_common_truthvalue_conversion (location,
3934                                                      TREE_OPERAND (expr, 0)));
3935       goto ret;
3936
3937     case ERROR_MARK:
3938       return expr;
3939
3940     case INTEGER_CST:
3941       return integer_zerop (expr) ? truthvalue_false_node
3942                                   : truthvalue_true_node;
3943
3944     case REAL_CST:
3945       return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0)
3946              ? truthvalue_true_node
3947              : truthvalue_false_node;
3948
3949     case FIXED_CST:
3950       return fixed_compare (NE_EXPR, &TREE_FIXED_CST (expr),
3951                             &FCONST0 (TYPE_MODE (TREE_TYPE (expr))))
3952              ? truthvalue_true_node
3953              : truthvalue_false_node;
3954
3955     case FUNCTION_DECL:
3956       expr = build_unary_op (location, ADDR_EXPR, expr, 0);
3957       /* Fall through.  */
3958
3959     case ADDR_EXPR:
3960       {
3961         tree inner = TREE_OPERAND (expr, 0);
3962         if (decl_with_nonnull_addr_p (inner))
3963           {
3964             /* Common Ada/Pascal programmer's mistake.  */
3965             warning_at (location,
3966                         OPT_Waddress,
3967                         "the address of %qD will always evaluate as %<true%>",
3968                         inner);
3969             return truthvalue_true_node;
3970           }
3971
3972         /* If we still have a decl, it is possible for its address to
3973            be NULL, so we cannot optimize.  */
3974         if (DECL_P (inner))
3975           {
3976             gcc_assert (DECL_WEAK (inner));
3977             break;
3978           }
3979
3980         if (TREE_SIDE_EFFECTS (inner))
3981           {
3982             expr = build2 (COMPOUND_EXPR, truthvalue_type_node,
3983                            inner, truthvalue_true_node);
3984             goto ret;
3985           }
3986         else
3987           return truthvalue_true_node;
3988       }
3989
3990     case COMPLEX_EXPR:
3991       expr = build_binary_op (EXPR_LOCATION (expr),
3992                               (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
3993                                ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
3994                 c_common_truthvalue_conversion (location,
3995                                                 TREE_OPERAND (expr, 0)),
3996                 c_common_truthvalue_conversion (location,
3997                                                 TREE_OPERAND (expr, 1)),
3998                               0);
3999       goto ret;
4000
4001     case NEGATE_EXPR:
4002     case ABS_EXPR:
4003     case FLOAT_EXPR:
4004     case EXCESS_PRECISION_EXPR:
4005       /* These don't change whether an object is nonzero or zero.  */
4006       return c_common_truthvalue_conversion (location, TREE_OPERAND (expr, 0));
4007
4008     case LROTATE_EXPR:
4009     case RROTATE_EXPR:
4010       /* These don't change whether an object is zero or nonzero, but
4011          we can't ignore them if their second arg has side-effects.  */
4012       if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
4013         {
4014           expr = build2 (COMPOUND_EXPR, truthvalue_type_node,
4015                          TREE_OPERAND (expr, 1),
4016                          c_common_truthvalue_conversion
4017                          (location, TREE_OPERAND (expr, 0)));
4018           goto ret;
4019         }
4020       else
4021         return c_common_truthvalue_conversion (location,
4022                                                TREE_OPERAND (expr, 0));
4023
4024     case COND_EXPR:
4025       /* Distribute the conversion into the arms of a COND_EXPR.  */
4026       if (c_dialect_cxx ())
4027         {
4028           expr = fold_build3_loc (location, COND_EXPR, truthvalue_type_node,
4029                               TREE_OPERAND (expr, 0),
4030                               c_common_truthvalue_conversion (location,
4031                                                               TREE_OPERAND (expr,
4032                                                                             1)),
4033                               c_common_truthvalue_conversion (location,
4034                                                               TREE_OPERAND (expr,
4035                                                                             2)));
4036           goto ret;
4037         }
4038       else
4039         {
4040           /* Folding will happen later for C.  */
4041           expr = build3 (COND_EXPR, truthvalue_type_node,
4042                          TREE_OPERAND (expr, 0),
4043                          c_common_truthvalue_conversion (location,
4044                                                          TREE_OPERAND (expr, 1)),
4045                          c_common_truthvalue_conversion (location,
4046                                                          TREE_OPERAND (expr, 2)));
4047           goto ret;
4048         }
4049
4050     CASE_CONVERT:
4051       /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
4052          since that affects how `default_conversion' will behave.  */
4053       if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
4054           || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
4055         break;
4056       /* If this is widening the argument, we can ignore it.  */
4057       if (TYPE_PRECISION (TREE_TYPE (expr))
4058           >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
4059         return c_common_truthvalue_conversion (location,
4060                                                TREE_OPERAND (expr, 0));
4061       break;
4062
4063     case MODIFY_EXPR:
4064       if (!TREE_NO_WARNING (expr)
4065           && warn_parentheses)
4066         {
4067           warning (OPT_Wparentheses,
4068                    "suggest parentheses around assignment used as truth value");
4069           TREE_NO_WARNING (expr) = 1;
4070         }
4071       break;
4072
4073     default:
4074       break;
4075     }
4076
4077   if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
4078     {
4079       tree t = c_save_expr (expr);
4080       expr = (build_binary_op
4081               (EXPR_LOCATION (expr),
4082                (TREE_SIDE_EFFECTS (expr)
4083                 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
4084         c_common_truthvalue_conversion
4085                (location,
4086                 build_unary_op (location, REALPART_EXPR, t, 0)),
4087         c_common_truthvalue_conversion
4088                (location,
4089                 build_unary_op (location, IMAGPART_EXPR, t, 0)),
4090                0));
4091       goto ret;
4092     }
4093
4094   if (TREE_CODE (TREE_TYPE (expr)) == FIXED_POINT_TYPE)
4095     {
4096       tree fixed_zero_node = build_fixed (TREE_TYPE (expr),
4097                                           FCONST0 (TYPE_MODE
4098                                                    (TREE_TYPE (expr))));
4099       return build_binary_op (location, NE_EXPR, expr, fixed_zero_node, 1);
4100     }
4101   else
4102     return build_binary_op (location, NE_EXPR, expr, integer_zero_node, 1);
4103
4104  ret:
4105   protected_set_expr_location (expr, location);
4106   return expr;
4107 }
4108 \f
4109 static void def_builtin_1  (enum built_in_function fncode,
4110                             const char *name,
4111                             enum built_in_class fnclass,
4112                             tree fntype, tree libtype,
4113                             bool both_p, bool fallback_p, bool nonansi_p,
4114                             tree fnattrs, bool implicit_p);
4115
4116
4117 /* Apply the TYPE_QUALS to the new DECL.  */
4118
4119 void
4120 c_apply_type_quals_to_decl (int type_quals, tree decl)
4121 {
4122   tree type = TREE_TYPE (decl);
4123
4124   if (type == error_mark_node)
4125     return;
4126
4127   if (((type_quals & TYPE_QUAL_CONST)
4128        || (type && TREE_CODE (type) == REFERENCE_TYPE))
4129       /* An object declared 'const' is only readonly after it is
4130          initialized.  We don't have any way of expressing this currently,
4131          so we need to be conservative and unset TREE_READONLY for types
4132          with constructors.  Otherwise aliasing code will ignore stores in
4133          an inline constructor.  */
4134       && !(type && TYPE_NEEDS_CONSTRUCTING (type)))
4135     TREE_READONLY (decl) = 1;
4136   if (type_quals & TYPE_QUAL_VOLATILE)
4137     {
4138       TREE_SIDE_EFFECTS (decl) = 1;
4139       TREE_THIS_VOLATILE (decl) = 1;
4140     }
4141   if (type_quals & TYPE_QUAL_RESTRICT)
4142     {
4143       while (type && TREE_CODE (type) == ARRAY_TYPE)
4144         /* Allow 'restrict' on arrays of pointers.
4145            FIXME currently we just ignore it.  */
4146         type = TREE_TYPE (type);
4147       if (!type
4148           || !POINTER_TYPE_P (type)
4149           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))
4150         error ("invalid use of %<restrict%>");
4151     }
4152 }
4153
4154 /* Hash function for the problem of multiple type definitions in
4155    different files.  This must hash all types that will compare
4156    equal via comptypes to the same value.  In practice it hashes
4157    on some of the simple stuff and leaves the details to comptypes.  */
4158
4159 static hashval_t
4160 c_type_hash (const void *p)
4161 {
4162   int i = 0;
4163   int shift, size;
4164   const_tree const t = (const_tree) p;
4165   tree t2;
4166   switch (TREE_CODE (t))
4167     {
4168     /* For pointers, hash on pointee type plus some swizzling.  */
4169     case POINTER_TYPE:
4170       return c_type_hash (TREE_TYPE (t)) ^ 0x3003003;
4171     /* Hash on number of elements and total size.  */
4172     case ENUMERAL_TYPE:
4173       shift = 3;
4174       t2 = TYPE_VALUES (t);
4175       break;
4176     case RECORD_TYPE:
4177       shift = 0;
4178       t2 = TYPE_FIELDS (t);
4179       break;
4180     case QUAL_UNION_TYPE:
4181       shift = 1;
4182       t2 = TYPE_FIELDS (t);
4183       break;
4184     case UNION_TYPE:
4185       shift = 2;
4186       t2 = TYPE_FIELDS (t);
4187       break;
4188     default:
4189       gcc_unreachable ();
4190     }
4191   for (; t2; t2 = TREE_CHAIN (t2))
4192     i++;
4193   /* We might have a VLA here.  */
4194   if (TREE_CODE (TYPE_SIZE (t)) != INTEGER_CST)
4195     size = 0;
4196   else
4197     size = TREE_INT_CST_LOW (TYPE_SIZE (t));
4198   return ((size << 24) | (i << shift));
4199 }
4200
4201 static GTY((param_is (union tree_node))) htab_t type_hash_table;
4202
4203 /* Return the typed-based alias set for T, which may be an expression
4204    or a type.  Return -1 if we don't do anything special.  */
4205
4206 alias_set_type
4207 c_common_get_alias_set (tree t)
4208 {
4209   tree u;
4210   PTR *slot;
4211
4212   /* For VLAs, use the alias set of the element type rather than the
4213      default of alias set 0 for types compared structurally.  */
4214   if (TYPE_P (t) && TYPE_STRUCTURAL_EQUALITY_P (t))
4215     {
4216       if (TREE_CODE (t) == ARRAY_TYPE)
4217         return get_alias_set (TREE_TYPE (t));
4218       return -1;
4219     }
4220
4221   /* Permit type-punning when accessing a union, provided the access
4222      is directly through the union.  For example, this code does not
4223      permit taking the address of a union member and then storing
4224      through it.  Even the type-punning allowed here is a GCC
4225      extension, albeit a common and useful one; the C standard says
4226      that such accesses have implementation-defined behavior.  */
4227   for (u = t;
4228        TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
4229        u = TREE_OPERAND (u, 0))
4230     if (TREE_CODE (u) == COMPONENT_REF
4231         && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
4232       return 0;
4233
4234   /* That's all the expressions we handle specially.  */
4235   if (!TYPE_P (t))
4236     return -1;
4237
4238   /* The C standard guarantees that any object may be accessed via an
4239      lvalue that has character type.  */
4240   if (t == char_type_node
4241       || t == signed_char_type_node
4242       || t == unsigned_char_type_node)
4243     return 0;
4244
4245   /* The C standard specifically allows aliasing between signed and
4246      unsigned variants of the same type.  We treat the signed
4247      variant as canonical.  */
4248   if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t))
4249     {
4250       tree t1 = c_common_signed_type (t);
4251
4252       /* t1 == t can happen for boolean nodes which are always unsigned.  */
4253       if (t1 != t)
4254         return get_alias_set (t1);
4255     }
4256   else if (POINTER_TYPE_P (t))
4257     {
4258       tree t1;
4259
4260       /* Unfortunately, there is no canonical form of a pointer type.
4261          In particular, if we have `typedef int I', then `int *', and
4262          `I *' are different types.  So, we have to pick a canonical
4263          representative.  We do this below.
4264
4265          Technically, this approach is actually more conservative that
4266          it needs to be.  In particular, `const int *' and `int *'
4267          should be in different alias sets, according to the C and C++
4268          standard, since their types are not the same, and so,
4269          technically, an `int **' and `const int **' cannot point at
4270          the same thing.
4271
4272          But, the standard is wrong.  In particular, this code is
4273          legal C++:
4274
4275             int *ip;
4276             int **ipp = &ip;
4277             const int* const* cipp = ipp;
4278
4279          And, it doesn't make sense for that to be legal unless you
4280          can dereference IPP and CIPP.  So, we ignore cv-qualifiers on
4281          the pointed-to types.  This issue has been reported to the
4282          C++ committee.  */
4283       t1 = build_type_no_quals (t);
4284       if (t1 != t)
4285         return get_alias_set (t1);
4286     }
4287
4288   /* Handle the case of multiple type nodes referring to "the same" type,
4289      which occurs with IMA.  These share an alias set.  FIXME:  Currently only
4290      C90 is handled.  (In C99 type compatibility is not transitive, which
4291      complicates things mightily. The alias set splay trees can theoretically
4292      represent this, but insertion is tricky when you consider all the
4293      different orders things might arrive in.) */
4294
4295   if (c_language != clk_c || flag_isoc99)
4296     return -1;
4297
4298   /* Save time if there's only one input file.  */
4299   if (num_in_fnames == 1)
4300     return -1;
4301
4302   /* Pointers need special handling if they point to any type that
4303      needs special handling (below).  */
4304   if (TREE_CODE (t) == POINTER_TYPE)
4305     {
4306       tree t2;
4307       /* Find bottom type under any nested POINTERs.  */
4308       for (t2 = TREE_TYPE (t);
4309            TREE_CODE (t2) == POINTER_TYPE;
4310            t2 = TREE_TYPE (t2))
4311         ;
4312       if (TREE_CODE (t2) != RECORD_TYPE
4313           && TREE_CODE (t2) != ENUMERAL_TYPE
4314           && TREE_CODE (t2) != QUAL_UNION_TYPE
4315           && TREE_CODE (t2) != UNION_TYPE)
4316         return -1;
4317       if (TYPE_SIZE (t2) == 0)
4318         return -1;
4319     }
4320   /* These are the only cases that need special handling.  */
4321   if (TREE_CODE (t) != RECORD_TYPE
4322       && TREE_CODE (t) != ENUMERAL_TYPE
4323       && TREE_CODE (t) != QUAL_UNION_TYPE
4324       && TREE_CODE (t) != UNION_TYPE
4325       && TREE_CODE (t) != POINTER_TYPE)
4326     return -1;
4327   /* Undefined? */
4328   if (TYPE_SIZE (t) == 0)
4329     return -1;
4330
4331   /* Look up t in hash table.  Only one of the compatible types within each
4332      alias set is recorded in the table.  */
4333   if (!type_hash_table)
4334     type_hash_table = htab_create_ggc (1021, c_type_hash,
4335             (htab_eq) lang_hooks.types_compatible_p,
4336             NULL);
4337   slot = htab_find_slot (type_hash_table, t, INSERT);
4338   if (*slot != NULL)
4339     {
4340       TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot);
4341       return TYPE_ALIAS_SET ((tree)*slot);
4342     }
4343   else
4344     /* Our caller will assign and record (in t) a new alias set; all we need
4345        to do is remember t in the hash table.  */
4346     *slot = t;
4347
4348   return -1;
4349 }
4350 \f
4351 /* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where
4352    the second parameter indicates which OPERATOR is being applied.
4353    The COMPLAIN flag controls whether we should diagnose possibly
4354    ill-formed constructs or not.  LOC is the location of the SIZEOF or
4355    TYPEOF operator.  */
4356
4357 tree
4358 c_sizeof_or_alignof_type (location_t loc,
4359                           tree type, bool is_sizeof, int complain)
4360 {
4361   const char *op_name;
4362   tree value = NULL;
4363   enum tree_code type_code = TREE_CODE (type);
4364
4365   op_name = is_sizeof ? "sizeof" : "__alignof__";
4366
4367   if (type_code == FUNCTION_TYPE)
4368     {
4369       if (is_sizeof)
4370         {
4371           if (complain && (pedantic || warn_pointer_arith))
4372             pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
4373                      "invalid application of %<sizeof%> to a function type");
4374           else if (!complain)
4375             return error_mark_node;
4376           value = size_one_node;
4377         }
4378       else
4379         value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);
4380     }
4381   else if (type_code == VOID_TYPE || type_code == ERROR_MARK)
4382     {
4383       if (type_code == VOID_TYPE
4384           && complain && (pedantic || warn_pointer_arith))
4385         pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
4386                  "invalid application of %qs to a void type", op_name);
4387       else if (!complain)
4388         return error_mark_node;
4389       value = size_one_node;
4390     }
4391   else if (!COMPLETE_TYPE_P (type))
4392     {
4393       if (complain)
4394         error_at (loc, "invalid application of %qs to incomplete type %qT ",
4395                   op_name, type);
4396       value = size_zero_node;
4397     }
4398   else
4399     {
4400       if (is_sizeof)
4401         /* Convert in case a char is more than one unit.  */
4402         value = size_binop_loc (loc, CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
4403                                 size_int (TYPE_PRECISION (char_type_node)
4404                                           / BITS_PER_UNIT));
4405       else
4406         value = size_int (TYPE_ALIGN_UNIT (type));
4407     }
4408
4409   /* VALUE will have an integer type with TYPE_IS_SIZETYPE set.
4410      TYPE_IS_SIZETYPE means that certain things (like overflow) will
4411      never happen.  However, this node should really have type
4412      `size_t', which is just a typedef for an ordinary integer type.  */
4413   value = fold_convert_loc (loc, size_type_node, value);
4414   gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value)));
4415
4416   return value;
4417 }
4418
4419 /* Implement the __alignof keyword: Return the minimum required
4420    alignment of EXPR, measured in bytes.  For VAR_DECLs,
4421    FUNCTION_DECLs and FIELD_DECLs return DECL_ALIGN (which can be set
4422    from an "aligned" __attribute__ specification).  LOC is the
4423    location of the ALIGNOF operator.  */
4424
4425 tree
4426 c_alignof_expr (location_t loc, tree expr)
4427 {
4428   tree t;
4429
4430   if (VAR_OR_FUNCTION_DECL_P (expr))
4431     t = size_int (DECL_ALIGN_UNIT (expr));
4432
4433   else if (TREE_CODE (expr) == COMPONENT_REF
4434            && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1)))
4435     {
4436       error_at (loc, "%<__alignof%> applied to a bit-field");
4437       t = size_one_node;
4438     }
4439   else if (TREE_CODE (expr) == COMPONENT_REF
4440            && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL)
4441     t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1)));
4442
4443   else if (TREE_CODE (expr) == INDIRECT_REF)
4444     {
4445       tree t = TREE_OPERAND (expr, 0);
4446       tree best = t;
4447       int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
4448
4449       while (CONVERT_EXPR_P (t)
4450              && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE)
4451         {
4452           int thisalign;
4453
4454           t = TREE_OPERAND (t, 0);
4455           thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
4456           if (thisalign > bestalign)
4457             best = t, bestalign = thisalign;
4458         }
4459       return c_alignof (loc, TREE_TYPE (TREE_TYPE (best)));
4460     }
4461   else
4462     return c_alignof (loc, TREE_TYPE (expr));
4463
4464   return fold_convert_loc (loc, size_type_node, t);
4465 }
4466 \f
4467 /* Handle C and C++ default attributes.  */
4468
4469 enum built_in_attribute
4470 {
4471 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
4472 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
4473 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
4474 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
4475 #include "builtin-attrs.def"
4476 #undef DEF_ATTR_NULL_TREE
4477 #undef DEF_ATTR_INT
4478 #undef DEF_ATTR_IDENT
4479 #undef DEF_ATTR_TREE_LIST
4480   ATTR_LAST
4481 };
4482
4483 static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
4484
4485 static void c_init_attributes (void);
4486
4487 enum c_builtin_type
4488 {
4489 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
4490 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
4491 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
4492 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
4493 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
4494 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
4495 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
4496 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) NAME,
4497 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7) NAME,
4498 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
4499 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
4500 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
4501 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
4502 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
4503 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \
4504   NAME,
4505 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
4506 #include "builtin-types.def"
4507 #undef DEF_PRIMITIVE_TYPE
4508 #undef DEF_FUNCTION_TYPE_0
4509 #undef DEF_FUNCTION_TYPE_1
4510 #undef DEF_FUNCTION_TYPE_2
4511 #undef DEF_FUNCTION_TYPE_3
4512 #undef DEF_FUNCTION_TYPE_4
4513 #undef DEF_FUNCTION_TYPE_5
4514 #undef DEF_FUNCTION_TYPE_6
4515 #undef DEF_FUNCTION_TYPE_7
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   BT_LAST
4524 };
4525
4526 typedef enum c_builtin_type builtin_type;
4527
4528 /* A temporary array for c_common_nodes_and_builtins.  Used in
4529    communication with def_fn_type.  */
4530 static tree builtin_types[(int) BT_LAST + 1];
4531
4532 /* A helper function for c_common_nodes_and_builtins.  Build function type
4533    for DEF with return type RET and N arguments.  If VAR is true, then the
4534    function should be variadic after those N arguments.
4535
4536    Takes special care not to ICE if any of the types involved are
4537    error_mark_node, which indicates that said type is not in fact available
4538    (see builtin_type_for_size).  In which case the function type as a whole
4539    should be error_mark_node.  */
4540
4541 static void
4542 def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...)
4543 {
4544   tree args = NULL, t;
4545   va_list list;
4546   int i;
4547
4548   va_start (list, n);
4549   for (i = 0; i < n; ++i)
4550     {
4551       builtin_type a = (builtin_type) va_arg (list, int);
4552       t = builtin_types[a];
4553       if (t == error_mark_node)
4554         goto egress;
4555       args = tree_cons (NULL_TREE, t, args);
4556     }
4557   va_end (list);
4558
4559   args = nreverse (args);
4560   if (!var)
4561     args = chainon (args, void_list_node);
4562
4563   t = builtin_types[ret];
4564   if (t == error_mark_node)
4565     goto egress;
4566   t = build_function_type (t, args);
4567
4568  egress:
4569   builtin_types[def] = t;
4570 }
4571
4572 /* Build builtin functions common to both C and C++ language
4573    frontends.  */
4574
4575 static void
4576 c_define_builtins (tree va_list_ref_type_node, tree va_list_arg_type_node)
4577 {
4578 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
4579   builtin_types[ENUM] = VALUE;
4580 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
4581   def_fn_type (ENUM, RETURN, 0, 0);
4582 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
4583   def_fn_type (ENUM, RETURN, 0, 1, ARG1);
4584 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
4585   def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
4586 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
4587   def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
4588 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
4589   def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
4590 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
4591   def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
4592 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
4593                             ARG6)                                       \
4594   def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
4595 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
4596                             ARG6, ARG7)                                 \
4597   def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
4598 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
4599   def_fn_type (ENUM, RETURN, 1, 0);
4600 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
4601   def_fn_type (ENUM, RETURN, 1, 1, ARG1);
4602 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
4603   def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
4604 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
4605   def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
4606 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
4607   def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
4608 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
4609   def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
4610 #define DEF_POINTER_TYPE(ENUM, TYPE) \
4611   builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
4612
4613 #include "builtin-types.def"
4614
4615 #undef DEF_PRIMITIVE_TYPE
4616 #undef DEF_FUNCTION_TYPE_1
4617 #undef DEF_FUNCTION_TYPE_2
4618 #undef DEF_FUNCTION_TYPE_3
4619 #undef DEF_FUNCTION_TYPE_4
4620 #undef DEF_FUNCTION_TYPE_5
4621 #undef DEF_FUNCTION_TYPE_6
4622 #undef DEF_FUNCTION_TYPE_VAR_0
4623 #undef DEF_FUNCTION_TYPE_VAR_1
4624 #undef DEF_FUNCTION_TYPE_VAR_2
4625 #undef DEF_FUNCTION_TYPE_VAR_3
4626 #undef DEF_FUNCTION_TYPE_VAR_4
4627 #undef DEF_FUNCTION_TYPE_VAR_5
4628 #undef DEF_POINTER_TYPE
4629   builtin_types[(int) BT_LAST] = NULL_TREE;
4630
4631   c_init_attributes ();
4632
4633 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
4634                     NONANSI_P, ATTRS, IMPLICIT, COND)                   \
4635   if (NAME && COND)                                                     \
4636     def_builtin_1 (ENUM, NAME, CLASS,                                   \
4637                    builtin_types[(int) TYPE],                           \
4638                    builtin_types[(int) LIBTYPE],                        \
4639                    BOTH_P, FALLBACK_P, NONANSI_P,                       \
4640                    built_in_attributes[(int) ATTRS], IMPLICIT);
4641 #include "builtins.def"
4642 #undef DEF_BUILTIN
4643
4644   targetm.init_builtins ();
4645
4646   build_common_builtin_nodes ();
4647
4648   if (flag_mudflap)
4649     mudflap_init ();
4650 }
4651
4652 /* Like get_identifier, but avoid warnings about null arguments when
4653    the argument may be NULL for targets where GCC lacks stdint.h type
4654    information.  */
4655
4656 static inline tree
4657 c_get_ident (const char *id)
4658 {
4659   return get_identifier (id);
4660 }
4661
4662 /* Build tree nodes and builtin functions common to both C and C++ language
4663    frontends.  */
4664
4665 void
4666 c_common_nodes_and_builtins (void)
4667 {
4668   int char16_type_size;
4669   int char32_type_size;
4670   int wchar_type_size;
4671   tree array_domain_type;
4672   tree va_list_ref_type_node;
4673   tree va_list_arg_type_node;
4674
4675   /* Define `int' and `char' first so that dbx will output them first.  */
4676   record_builtin_type (RID_INT, NULL, integer_type_node);
4677   record_builtin_type (RID_CHAR, "char", char_type_node);
4678
4679   /* `signed' is the same as `int'.  FIXME: the declarations of "signed",
4680      "unsigned long", "long long unsigned" and "unsigned short" were in C++
4681      but not C.  Are the conditionals here needed?  */
4682   if (c_dialect_cxx ())
4683     record_builtin_type (RID_SIGNED, NULL, integer_type_node);
4684   record_builtin_type (RID_LONG, "long int", long_integer_type_node);
4685   record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
4686   record_builtin_type (RID_MAX, "long unsigned int",
4687                        long_unsigned_type_node);
4688   if (c_dialect_cxx ())
4689     record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
4690   record_builtin_type (RID_MAX, "long long int",
4691                        long_long_integer_type_node);
4692   record_builtin_type (RID_MAX, "long long unsigned int",
4693                        long_long_unsigned_type_node);
4694   if (c_dialect_cxx ())
4695     record_builtin_type (RID_MAX, "long long unsigned",
4696                          long_long_unsigned_type_node);
4697   record_builtin_type (RID_SHORT, "short int", short_integer_type_node);
4698   record_builtin_type (RID_MAX, "short unsigned int",
4699                        short_unsigned_type_node);
4700   if (c_dialect_cxx ())
4701     record_builtin_type (RID_MAX, "unsigned short",
4702                          short_unsigned_type_node);
4703
4704   /* Define both `signed char' and `unsigned char'.  */
4705   record_builtin_type (RID_MAX, "signed char", signed_char_type_node);
4706   record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node);
4707
4708   /* These are types that c_common_type_for_size and
4709      c_common_type_for_mode use.  */
4710   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4711                                          TYPE_DECL, NULL_TREE,
4712                                          intQI_type_node));
4713   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4714                                          TYPE_DECL, NULL_TREE,
4715                                          intHI_type_node));
4716   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4717                                          TYPE_DECL, NULL_TREE,
4718                                          intSI_type_node));
4719   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4720                                          TYPE_DECL, NULL_TREE,
4721                                          intDI_type_node));
4722 #if HOST_BITS_PER_WIDE_INT >= 64
4723   if (targetm.scalar_mode_supported_p (TImode))
4724     lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4725                                            TYPE_DECL,
4726                                            get_identifier ("__int128_t"),
4727                                            intTI_type_node));
4728 #endif
4729   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4730                                          TYPE_DECL, NULL_TREE,
4731                                          unsigned_intQI_type_node));
4732   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4733                                          TYPE_DECL, NULL_TREE,
4734                                          unsigned_intHI_type_node));
4735   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4736                                          TYPE_DECL, NULL_TREE,
4737                                          unsigned_intSI_type_node));
4738   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4739                                          TYPE_DECL, NULL_TREE,
4740                                          unsigned_intDI_type_node));
4741 #if HOST_BITS_PER_WIDE_INT >= 64
4742   if (targetm.scalar_mode_supported_p (TImode))
4743     lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4744                                            TYPE_DECL,
4745                                            get_identifier ("__uint128_t"),
4746                                            unsigned_intTI_type_node));
4747 #endif
4748
4749   /* Create the widest literal types.  */
4750   widest_integer_literal_type_node
4751     = make_signed_type (HOST_BITS_PER_WIDE_INT * 2);
4752   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4753                                          TYPE_DECL, NULL_TREE,
4754                                          widest_integer_literal_type_node));
4755
4756   widest_unsigned_literal_type_node
4757     = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2);
4758   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4759                                          TYPE_DECL, NULL_TREE,
4760                                          widest_unsigned_literal_type_node));
4761
4762   /* `unsigned long' is the standard type for sizeof.
4763      Note that stddef.h uses `unsigned long',
4764      and this must agree, even if long and int are the same size.  */
4765   size_type_node =
4766     TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE)));
4767   signed_size_type_node = c_common_signed_type (size_type_node);
4768   set_sizetype (size_type_node);
4769
4770   pid_type_node =
4771     TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE)));
4772
4773   build_common_tree_nodes_2 (flag_short_double);
4774
4775   record_builtin_type (RID_FLOAT, NULL, float_type_node);
4776   record_builtin_type (RID_DOUBLE, NULL, double_type_node);
4777   record_builtin_type (RID_MAX, "long double", long_double_type_node);
4778
4779   /* Only supported decimal floating point extension if the target
4780      actually supports underlying modes. */
4781   if (targetm.scalar_mode_supported_p (SDmode)
4782       && targetm.scalar_mode_supported_p (DDmode)
4783       && targetm.scalar_mode_supported_p (TDmode))
4784     {
4785       record_builtin_type (RID_DFLOAT32, NULL, dfloat32_type_node);
4786       record_builtin_type (RID_DFLOAT64, NULL, dfloat64_type_node);
4787       record_builtin_type (RID_DFLOAT128, NULL, dfloat128_type_node);
4788     }
4789
4790   if (targetm.fixed_point_supported_p ())
4791     {
4792       record_builtin_type (RID_MAX, "short _Fract", short_fract_type_node);
4793       record_builtin_type (RID_FRACT, NULL, fract_type_node);
4794       record_builtin_type (RID_MAX, "long _Fract", long_fract_type_node);
4795       record_builtin_type (RID_MAX, "long long _Fract",
4796                            long_long_fract_type_node);
4797       record_builtin_type (RID_MAX, "unsigned short _Fract",
4798                            unsigned_short_fract_type_node);
4799       record_builtin_type (RID_MAX, "unsigned _Fract",
4800                            unsigned_fract_type_node);
4801       record_builtin_type (RID_MAX, "unsigned long _Fract",
4802                            unsigned_long_fract_type_node);
4803       record_builtin_type (RID_MAX, "unsigned long long _Fract",
4804                            unsigned_long_long_fract_type_node);
4805       record_builtin_type (RID_MAX, "_Sat short _Fract",
4806                            sat_short_fract_type_node);
4807       record_builtin_type (RID_MAX, "_Sat _Fract", sat_fract_type_node);
4808       record_builtin_type (RID_MAX, "_Sat long _Fract",
4809                            sat_long_fract_type_node);
4810       record_builtin_type (RID_MAX, "_Sat long long _Fract",
4811                            sat_long_long_fract_type_node);
4812       record_builtin_type (RID_MAX, "_Sat unsigned short _Fract",
4813                            sat_unsigned_short_fract_type_node);
4814       record_builtin_type (RID_MAX, "_Sat unsigned _Fract",
4815                            sat_unsigned_fract_type_node);
4816       record_builtin_type (RID_MAX, "_Sat unsigned long _Fract",
4817                            sat_unsigned_long_fract_type_node);
4818       record_builtin_type (RID_MAX, "_Sat unsigned long long _Fract",
4819                            sat_unsigned_long_long_fract_type_node);
4820       record_builtin_type (RID_MAX, "short _Accum", short_accum_type_node);
4821       record_builtin_type (RID_ACCUM, NULL, accum_type_node);
4822       record_builtin_type (RID_MAX, "long _Accum", long_accum_type_node);
4823       record_builtin_type (RID_MAX, "long long _Accum",
4824                            long_long_accum_type_node);
4825       record_builtin_type (RID_MAX, "unsigned short _Accum",
4826                            unsigned_short_accum_type_node);
4827       record_builtin_type (RID_MAX, "unsigned _Accum",
4828                            unsigned_accum_type_node);
4829       record_builtin_type (RID_MAX, "unsigned long _Accum",
4830                            unsigned_long_accum_type_node);
4831       record_builtin_type (RID_MAX, "unsigned long long _Accum",
4832                            unsigned_long_long_accum_type_node);
4833       record_builtin_type (RID_MAX, "_Sat short _Accum",
4834                            sat_short_accum_type_node);
4835       record_builtin_type (RID_MAX, "_Sat _Accum", sat_accum_type_node);
4836       record_builtin_type (RID_MAX, "_Sat long _Accum",
4837                            sat_long_accum_type_node);
4838       record_builtin_type (RID_MAX, "_Sat long long _Accum",
4839                           sat_long_long_accum_type_node);
4840       record_builtin_type (RID_MAX, "_Sat unsigned short _Accum",
4841                            sat_unsigned_short_accum_type_node);
4842       record_builtin_type (RID_MAX, "_Sat unsigned _Accum",
4843                            sat_unsigned_accum_type_node);
4844       record_builtin_type (RID_MAX, "_Sat unsigned long _Accum",
4845                            sat_unsigned_long_accum_type_node);
4846       record_builtin_type (RID_MAX, "_Sat unsigned long long _Accum",
4847                            sat_unsigned_long_long_accum_type_node);
4848
4849     }
4850
4851   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4852                                          TYPE_DECL,
4853                                          get_identifier ("complex int"),
4854                                          complex_integer_type_node));
4855   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4856                                          TYPE_DECL,
4857                                          get_identifier ("complex float"),
4858                                          complex_float_type_node));
4859   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4860                                          TYPE_DECL,
4861                                          get_identifier ("complex double"),
4862                                          complex_double_type_node));
4863   lang_hooks.decls.pushdecl
4864     (build_decl (UNKNOWN_LOCATION,
4865                  TYPE_DECL, get_identifier ("complex long double"),
4866                  complex_long_double_type_node));
4867
4868   if (c_dialect_cxx ())
4869     /* For C++, make fileptr_type_node a distinct void * type until
4870        FILE type is defined.  */
4871     fileptr_type_node = build_variant_type_copy (ptr_type_node);
4872
4873   record_builtin_type (RID_VOID, NULL, void_type_node);
4874
4875   /* Set the TYPE_NAME for any variants that were built before
4876      record_builtin_type gave names to the built-in types. */
4877   {
4878     tree void_name = TYPE_NAME (void_type_node);
4879     TYPE_NAME (void_type_node) = NULL_TREE;
4880     TYPE_NAME (build_qualified_type (void_type_node, TYPE_QUAL_CONST))
4881       = void_name;
4882     TYPE_NAME (void_type_node) = void_name;
4883   }
4884
4885   /* This node must not be shared.  */
4886   void_zero_node = make_node (INTEGER_CST);
4887   TREE_TYPE (void_zero_node) = void_type_node;
4888
4889   void_list_node = build_void_list_node ();
4890
4891   /* Make a type to be the domain of a few array types
4892      whose domains don't really matter.
4893      200 is small enough that it always fits in size_t
4894      and large enough that it can hold most function names for the
4895      initializations of __FUNCTION__ and __PRETTY_FUNCTION__.  */
4896   array_domain_type = build_index_type (size_int (200));
4897
4898   /* Make a type for arrays of characters.
4899      With luck nothing will ever really depend on the length of this
4900      array type.  */
4901   char_array_type_node
4902     = build_array_type (char_type_node, array_domain_type);
4903
4904   /* Likewise for arrays of ints.  */
4905   int_array_type_node
4906     = build_array_type (integer_type_node, array_domain_type);
4907
4908   string_type_node = build_pointer_type (char_type_node);
4909   const_string_type_node
4910     = build_pointer_type (build_qualified_type
4911                           (char_type_node, TYPE_QUAL_CONST));
4912
4913   /* This is special for C++ so functions can be overloaded.  */
4914   wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE);
4915   wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node));
4916   wchar_type_size = TYPE_PRECISION (wchar_type_node);
4917   underlying_wchar_type_node = wchar_type_node;
4918   if (c_dialect_cxx ())
4919     {
4920       if (TYPE_UNSIGNED (wchar_type_node))
4921         wchar_type_node = make_unsigned_type (wchar_type_size);
4922       else
4923         wchar_type_node = make_signed_type (wchar_type_size);
4924       record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node);
4925     }
4926
4927   /* This is for wide string constants.  */
4928   wchar_array_type_node
4929     = build_array_type (wchar_type_node, array_domain_type);
4930
4931   /* Define 'char16_t'.  */
4932   char16_type_node = get_identifier (CHAR16_TYPE);
4933   char16_type_node = TREE_TYPE (identifier_global_value (char16_type_node));
4934   char16_type_size = TYPE_PRECISION (char16_type_node);
4935   if (c_dialect_cxx ())
4936     {
4937       char16_type_node = make_unsigned_type (char16_type_size);
4938
4939       if (cxx_dialect == cxx0x)
4940         record_builtin_type (RID_CHAR16, "char16_t", char16_type_node);
4941     }
4942
4943   /* This is for UTF-16 string constants.  */
4944   char16_array_type_node
4945     = build_array_type (char16_type_node, array_domain_type);
4946
4947   /* Define 'char32_t'.  */
4948   char32_type_node = get_identifier (CHAR32_TYPE);
4949   char32_type_node = TREE_TYPE (identifier_global_value (char32_type_node));
4950   char32_type_size = TYPE_PRECISION (char32_type_node);
4951   if (c_dialect_cxx ())
4952     {
4953       char32_type_node = make_unsigned_type (char32_type_size);
4954
4955       if (cxx_dialect == cxx0x)
4956         record_builtin_type (RID_CHAR32, "char32_t", char32_type_node);
4957     }
4958
4959   /* This is for UTF-32 string constants.  */
4960   char32_array_type_node
4961     = build_array_type (char32_type_node, array_domain_type);
4962
4963   wint_type_node =
4964     TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE)));
4965
4966   intmax_type_node =
4967     TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE)));
4968   uintmax_type_node =
4969     TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE)));
4970
4971   if (SIG_ATOMIC_TYPE)
4972     sig_atomic_type_node =
4973       TREE_TYPE (identifier_global_value (c_get_ident (SIG_ATOMIC_TYPE)));
4974   if (INT8_TYPE)
4975     int8_type_node =
4976       TREE_TYPE (identifier_global_value (c_get_ident (INT8_TYPE)));
4977   if (INT16_TYPE)
4978     int16_type_node =
4979       TREE_TYPE (identifier_global_value (c_get_ident (INT16_TYPE)));
4980   if (INT32_TYPE)
4981     int32_type_node =
4982       TREE_TYPE (identifier_global_value (c_get_ident (INT32_TYPE)));
4983   if (INT64_TYPE)
4984     int64_type_node =
4985       TREE_TYPE (identifier_global_value (c_get_ident (INT64_TYPE)));
4986   if (UINT8_TYPE)
4987     uint8_type_node =
4988       TREE_TYPE (identifier_global_value (c_get_ident (UINT8_TYPE)));
4989   if (UINT16_TYPE)
4990     uint16_type_node =
4991       TREE_TYPE (identifier_global_value (c_get_ident (UINT16_TYPE)));
4992   if (UINT32_TYPE)
4993     c_uint32_type_node =
4994       TREE_TYPE (identifier_global_value (c_get_ident (UINT32_TYPE)));
4995   if (UINT64_TYPE)
4996     c_uint64_type_node =
4997       TREE_TYPE (identifier_global_value (c_get_ident (UINT64_TYPE)));
4998   if (INT_LEAST8_TYPE)
4999     int_least8_type_node =
5000       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST8_TYPE)));
5001   if (INT_LEAST16_TYPE)
5002     int_least16_type_node =
5003       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST16_TYPE)));
5004   if (INT_LEAST32_TYPE)
5005     int_least32_type_node =
5006       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST32_TYPE)));
5007   if (INT_LEAST64_TYPE)
5008     int_least64_type_node =
5009       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST64_TYPE)));
5010   if (UINT_LEAST8_TYPE)
5011     uint_least8_type_node =
5012       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST8_TYPE)));
5013   if (UINT_LEAST16_TYPE)
5014     uint_least16_type_node =
5015       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST16_TYPE)));
5016   if (UINT_LEAST32_TYPE)
5017     uint_least32_type_node =
5018       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST32_TYPE)));
5019   if (UINT_LEAST64_TYPE)
5020     uint_least64_type_node =
5021       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST64_TYPE)));
5022   if (INT_FAST8_TYPE)
5023     int_fast8_type_node =
5024       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST8_TYPE)));
5025   if (INT_FAST16_TYPE)
5026     int_fast16_type_node =
5027       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST16_TYPE)));
5028   if (INT_FAST32_TYPE)
5029     int_fast32_type_node =
5030       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST32_TYPE)));
5031   if (INT_FAST64_TYPE)
5032     int_fast64_type_node =
5033       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST64_TYPE)));
5034   if (UINT_FAST8_TYPE)
5035     uint_fast8_type_node =
5036       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST8_TYPE)));
5037   if (UINT_FAST16_TYPE)
5038     uint_fast16_type_node =
5039       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST16_TYPE)));
5040   if (UINT_FAST32_TYPE)
5041     uint_fast32_type_node =
5042       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST32_TYPE)));
5043   if (UINT_FAST64_TYPE)
5044     uint_fast64_type_node =
5045       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST64_TYPE)));
5046   if (INTPTR_TYPE)
5047     intptr_type_node =
5048       TREE_TYPE (identifier_global_value (c_get_ident (INTPTR_TYPE)));
5049   if (UINTPTR_TYPE)
5050     uintptr_type_node =
5051       TREE_TYPE (identifier_global_value (c_get_ident (UINTPTR_TYPE)));
5052
5053   default_function_type = build_function_type (integer_type_node, NULL_TREE);
5054   ptrdiff_type_node
5055     = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE)));
5056   unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node);
5057
5058   lang_hooks.decls.pushdecl
5059     (build_decl (UNKNOWN_LOCATION,
5060                  TYPE_DECL, get_identifier ("__builtin_va_list"),
5061                  va_list_type_node));
5062 #ifdef TARGET_ENUM_VA_LIST
5063   {
5064     int l;
5065     const char *pname;
5066     tree ptype;
5067     for (l = 0; TARGET_ENUM_VA_LIST (l, &pname, &ptype); ++l)
5068       {
5069         lang_hooks.decls.pushdecl
5070           (build_decl (UNKNOWN_LOCATION,
5071                        TYPE_DECL, get_identifier (pname),
5072                        ptype));
5073
5074       }
5075   }
5076 #endif
5077
5078   if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
5079     {
5080       va_list_arg_type_node = va_list_ref_type_node =
5081         build_pointer_type (TREE_TYPE (va_list_type_node));
5082     }
5083   else
5084     {
5085       va_list_arg_type_node = va_list_type_node;
5086       va_list_ref_type_node = build_reference_type (va_list_type_node);
5087     }
5088
5089   if (!flag_preprocess_only)
5090     c_define_builtins (va_list_ref_type_node, va_list_arg_type_node);
5091
5092   main_identifier_node = get_identifier ("main");
5093
5094   /* Create the built-in __null node.  It is important that this is
5095      not shared.  */
5096   null_node = make_node (INTEGER_CST);
5097   TREE_TYPE (null_node) = c_common_type_for_size (POINTER_SIZE, 0);
5098
5099   /* Since builtin_types isn't gc'ed, don't export these nodes.  */
5100   memset (builtin_types, 0, sizeof (builtin_types));
5101 }
5102
5103 /* The number of named compound-literals generated thus far.  */
5104 static GTY(()) int compound_literal_number;
5105
5106 /* Set DECL_NAME for DECL, a VAR_DECL for a compound-literal.  */
5107
5108 void
5109 set_compound_literal_name (tree decl)
5110 {
5111   char *name;
5112   ASM_FORMAT_PRIVATE_NAME (name, "__compound_literal",
5113                            compound_literal_number);
5114   compound_literal_number++;
5115   DECL_NAME (decl) = get_identifier (name);
5116 }
5117
5118 tree
5119 build_va_arg (location_t loc, tree expr, tree type)
5120 {
5121   expr = build1 (VA_ARG_EXPR, type, expr);
5122   SET_EXPR_LOCATION (expr, loc);
5123   return expr;
5124 }
5125
5126
5127 /* Linked list of disabled built-in functions.  */
5128
5129 typedef struct disabled_builtin
5130 {
5131   const char *name;
5132   struct disabled_builtin *next;
5133 } disabled_builtin;
5134 static disabled_builtin *disabled_builtins = NULL;
5135
5136 static bool builtin_function_disabled_p (const char *);
5137
5138 /* Disable a built-in function specified by -fno-builtin-NAME.  If NAME
5139    begins with "__builtin_", give an error.  */
5140
5141 void
5142 disable_builtin_function (const char *name)
5143 {
5144   if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
5145     error ("cannot disable built-in function %qs", name);
5146   else
5147     {
5148       disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin);
5149       new_disabled_builtin->name = name;
5150       new_disabled_builtin->next = disabled_builtins;
5151       disabled_builtins = new_disabled_builtin;
5152     }
5153 }
5154
5155
5156 /* Return true if the built-in function NAME has been disabled, false
5157    otherwise.  */
5158
5159 static bool
5160 builtin_function_disabled_p (const char *name)
5161 {
5162   disabled_builtin *p;
5163   for (p = disabled_builtins; p != NULL; p = p->next)
5164     {
5165       if (strcmp (name, p->name) == 0)
5166         return true;
5167     }
5168   return false;
5169 }
5170
5171
5172 /* Worker for DEF_BUILTIN.
5173    Possibly define a builtin function with one or two names.
5174    Does not declare a non-__builtin_ function if flag_no_builtin, or if
5175    nonansi_p and flag_no_nonansi_builtin.  */
5176
5177 static void
5178 def_builtin_1 (enum built_in_function fncode,
5179                const char *name,
5180                enum built_in_class fnclass,
5181                tree fntype, tree libtype,
5182                bool both_p, bool fallback_p, bool nonansi_p,
5183                tree fnattrs, bool implicit_p)
5184 {
5185   tree decl;
5186   const char *libname;
5187
5188   if (fntype == error_mark_node)
5189     return;
5190
5191   gcc_assert ((!both_p && !fallback_p)
5192               || !strncmp (name, "__builtin_",
5193                            strlen ("__builtin_")));
5194
5195   libname = name + strlen ("__builtin_");
5196   decl = add_builtin_function (name, fntype, fncode, fnclass,
5197                                (fallback_p ? libname : NULL),
5198                                fnattrs);
5199   if (both_p
5200       && !flag_no_builtin && !builtin_function_disabled_p (libname)
5201       && !(nonansi_p && flag_no_nonansi_builtin))
5202     add_builtin_function (libname, libtype, fncode, fnclass,
5203                           NULL, fnattrs);
5204
5205   built_in_decls[(int) fncode] = decl;
5206   if (implicit_p)
5207     implicit_built_in_decls[(int) fncode] = decl;
5208 }
5209 \f
5210 /* Nonzero if the type T promotes to int.  This is (nearly) the
5211    integral promotions defined in ISO C99 6.3.1.1/2.  */
5212
5213 bool
5214 c_promoting_integer_type_p (const_tree t)
5215 {
5216   switch (TREE_CODE (t))
5217     {
5218     case INTEGER_TYPE:
5219       return (TYPE_MAIN_VARIANT (t) == char_type_node
5220               || TYPE_MAIN_VARIANT (t) == signed_char_type_node
5221               || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node
5222               || TYPE_MAIN_VARIANT (t) == short_integer_type_node
5223               || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node
5224               || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node));
5225
5226     case ENUMERAL_TYPE:
5227       /* ??? Technically all enumerations not larger than an int
5228          promote to an int.  But this is used along code paths
5229          that only want to notice a size change.  */
5230       return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node);
5231
5232     case BOOLEAN_TYPE:
5233       return 1;
5234
5235     default:
5236       return 0;
5237     }
5238 }
5239
5240 /* Return 1 if PARMS specifies a fixed number of parameters
5241    and none of their types is affected by default promotions.  */
5242
5243 int
5244 self_promoting_args_p (const_tree parms)
5245 {
5246   const_tree t;
5247   for (t = parms; t; t = TREE_CHAIN (t))
5248     {
5249       tree type = TREE_VALUE (t);
5250
5251       if (type == error_mark_node)
5252         continue;
5253
5254       if (TREE_CHAIN (t) == 0 && type != void_type_node)
5255         return 0;
5256
5257       if (type == 0)
5258         return 0;
5259
5260       if (TYPE_MAIN_VARIANT (type) == float_type_node)
5261         return 0;
5262
5263       if (c_promoting_integer_type_p (type))
5264         return 0;
5265     }
5266   return 1;
5267 }
5268
5269 /* Recursively remove any '*' or '&' operator from TYPE.  */
5270 tree
5271 strip_pointer_operator (tree t)
5272 {
5273   while (POINTER_TYPE_P (t))
5274     t = TREE_TYPE (t);
5275   return t;
5276 }
5277
5278 /* Recursively remove pointer or array type from TYPE. */
5279 tree
5280 strip_pointer_or_array_types (tree t)
5281 {
5282   while (TREE_CODE (t) == ARRAY_TYPE || POINTER_TYPE_P (t))
5283     t = TREE_TYPE (t);
5284   return t;
5285 }
5286
5287 /* Used to compare case labels.  K1 and K2 are actually tree nodes
5288    representing case labels, or NULL_TREE for a `default' label.
5289    Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
5290    K2, and 0 if K1 and K2 are equal.  */
5291
5292 int
5293 case_compare (splay_tree_key k1, splay_tree_key k2)
5294 {
5295   /* Consider a NULL key (such as arises with a `default' label) to be
5296      smaller than anything else.  */
5297   if (!k1)
5298     return k2 ? -1 : 0;
5299   else if (!k2)
5300     return k1 ? 1 : 0;
5301
5302   return tree_int_cst_compare ((tree) k1, (tree) k2);
5303 }
5304
5305 /* Process a case label, located at LOC, for the range LOW_VALUE
5306    ... HIGH_VALUE.  If LOW_VALUE and HIGH_VALUE are both NULL_TREE
5307    then this case label is actually a `default' label.  If only
5308    HIGH_VALUE is NULL_TREE, then case label was declared using the
5309    usual C/C++ syntax, rather than the GNU case range extension.
5310    CASES is a tree containing all the case ranges processed so far;
5311    COND is the condition for the switch-statement itself.  Returns the
5312    CASE_LABEL_EXPR created, or ERROR_MARK_NODE if no CASE_LABEL_EXPR
5313    is created.  */
5314
5315 tree
5316 c_add_case_label (location_t loc, splay_tree cases, tree cond, tree orig_type,
5317                   tree low_value, tree high_value)
5318 {
5319   tree type;
5320   tree label;
5321   tree case_label;
5322   splay_tree_node node;
5323
5324   /* Create the LABEL_DECL itself.  */
5325   label = create_artificial_label (loc);
5326
5327   /* If there was an error processing the switch condition, bail now
5328      before we get more confused.  */
5329   if (!cond || cond == error_mark_node)
5330     goto error_out;
5331
5332   if ((low_value && TREE_TYPE (low_value)
5333        && POINTER_TYPE_P (TREE_TYPE (low_value)))
5334       || (high_value && TREE_TYPE (high_value)
5335           && POINTER_TYPE_P (TREE_TYPE (high_value))))
5336     {
5337       error_at (loc, "pointers are not permitted as case values");
5338       goto error_out;
5339     }
5340
5341   /* Case ranges are a GNU extension.  */
5342   if (high_value)
5343     pedwarn (loc, OPT_pedantic,
5344              "range expressions in switch statements are non-standard");
5345
5346   type = TREE_TYPE (cond);
5347   if (low_value)
5348     {
5349       low_value = check_case_value (low_value);
5350       low_value = convert_and_check (type, low_value);
5351       if (low_value == error_mark_node)
5352         goto error_out;
5353     }
5354   if (high_value)
5355     {
5356       high_value = check_case_value (high_value);
5357       high_value = convert_and_check (type, high_value);
5358       if (high_value == error_mark_node)
5359         goto error_out;
5360     }
5361
5362   if (low_value && high_value)
5363     {
5364       /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
5365          really a case range, even though it was written that way.
5366          Remove the HIGH_VALUE to simplify later processing.  */
5367       if (tree_int_cst_equal (low_value, high_value))
5368         high_value = NULL_TREE;
5369       else if (!tree_int_cst_lt (low_value, high_value))
5370         warning_at (loc, 0, "empty range specified");
5371     }
5372
5373   /* See if the case is in range of the type of the original testing
5374      expression.  If both low_value and high_value are out of range,
5375      don't insert the case label and return NULL_TREE.  */
5376   if (low_value
5377       && !check_case_bounds (type, orig_type,
5378                              &low_value, high_value ? &high_value : NULL))
5379     return NULL_TREE;
5380
5381   /* Look up the LOW_VALUE in the table of case labels we already
5382      have.  */
5383   node = splay_tree_lookup (cases, (splay_tree_key) low_value);
5384   /* If there was not an exact match, check for overlapping ranges.
5385      There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
5386      that's a `default' label and the only overlap is an exact match.  */
5387   if (!node && (low_value || high_value))
5388     {
5389       splay_tree_node low_bound;
5390       splay_tree_node high_bound;
5391
5392       /* Even though there wasn't an exact match, there might be an
5393          overlap between this case range and another case range.
5394          Since we've (inductively) not allowed any overlapping case
5395          ranges, we simply need to find the greatest low case label
5396          that is smaller that LOW_VALUE, and the smallest low case
5397          label that is greater than LOW_VALUE.  If there is an overlap
5398          it will occur in one of these two ranges.  */
5399       low_bound = splay_tree_predecessor (cases,
5400                                           (splay_tree_key) low_value);
5401       high_bound = splay_tree_successor (cases,
5402                                          (splay_tree_key) low_value);
5403
5404       /* Check to see if the LOW_BOUND overlaps.  It is smaller than
5405          the LOW_VALUE, so there is no need to check unless the
5406          LOW_BOUND is in fact itself a case range.  */
5407       if (low_bound
5408           && CASE_HIGH ((tree) low_bound->value)
5409           && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
5410                                     low_value) >= 0)
5411         node = low_bound;
5412       /* Check to see if the HIGH_BOUND overlaps.  The low end of that
5413          range is bigger than the low end of the current range, so we
5414          are only interested if the current range is a real range, and
5415          not an ordinary case label.  */
5416       else if (high_bound
5417                && high_value
5418                && (tree_int_cst_compare ((tree) high_bound->key,
5419                                          high_value)
5420                    <= 0))
5421         node = high_bound;
5422     }
5423   /* If there was an overlap, issue an error.  */
5424   if (node)
5425     {
5426       tree duplicate = CASE_LABEL ((tree) node->value);
5427
5428       if (high_value)
5429         {
5430           error_at (loc, "duplicate (or overlapping) case value");
5431           error_at (DECL_SOURCE_LOCATION (duplicate),
5432                     "this is the first entry overlapping that value");
5433         }
5434       else if (low_value)
5435         {
5436           error_at (loc, "duplicate case value") ;
5437           error_at (DECL_SOURCE_LOCATION (duplicate), "previously used here");
5438         }
5439       else
5440         {
5441           error_at (loc, "multiple default labels in one switch");
5442           error_at (DECL_SOURCE_LOCATION (duplicate),
5443                     "this is the first default label");
5444         }
5445       goto error_out;
5446     }
5447
5448   /* Add a CASE_LABEL to the statement-tree.  */
5449   case_label = add_stmt (build_case_label (loc, low_value, high_value, label));
5450   /* Register this case label in the splay tree.  */
5451   splay_tree_insert (cases,
5452                      (splay_tree_key) low_value,
5453                      (splay_tree_value) case_label);
5454
5455   return case_label;
5456
5457  error_out:
5458   /* Add a label so that the back-end doesn't think that the beginning of
5459      the switch is unreachable.  Note that we do not add a case label, as
5460      that just leads to duplicates and thence to failure later on.  */
5461   if (!cases->root)
5462     {
5463       tree t = create_artificial_label (loc);
5464       add_stmt (build_stmt (loc, LABEL_EXPR, t));
5465     }
5466   return error_mark_node;
5467 }
5468
5469 /* Subroutines of c_do_switch_warnings, called via splay_tree_foreach.
5470    Used to verify that case values match up with enumerator values.  */
5471
5472 static void
5473 match_case_to_enum_1 (tree key, tree type, tree label)
5474 {
5475   char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1];
5476
5477   /* ??? Not working too hard to print the double-word value.
5478      Should perhaps be done with %lwd in the diagnostic routines?  */
5479   if (TREE_INT_CST_HIGH (key) == 0)
5480     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED,
5481               TREE_INT_CST_LOW (key));
5482   else if (!TYPE_UNSIGNED (type)
5483            && TREE_INT_CST_HIGH (key) == -1
5484            && TREE_INT_CST_LOW (key) != 0)
5485     snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED,
5486               -TREE_INT_CST_LOW (key));
5487   else
5488     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX,
5489               (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (key),
5490               (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (key));
5491
5492   if (TYPE_NAME (type) == 0)
5493     warning_at (DECL_SOURCE_LOCATION (CASE_LABEL (label)),
5494                 warn_switch ? OPT_Wswitch : OPT_Wswitch_enum,
5495                 "case value %qs not in enumerated type",
5496                 buf);
5497   else
5498     warning_at (DECL_SOURCE_LOCATION (CASE_LABEL (label)),
5499                 warn_switch ? OPT_Wswitch : OPT_Wswitch_enum,
5500                 "case value %qs not in enumerated type %qT",
5501                 buf, type);
5502 }
5503
5504 /* Subroutine of c_do_switch_warnings, called via splay_tree_foreach.
5505    Used to verify that case values match up with enumerator values.  */
5506
5507 static int
5508 match_case_to_enum (splay_tree_node node, void *data)
5509 {
5510   tree label = (tree) node->value;
5511   tree type = (tree) data;
5512
5513   /* Skip default case.  */
5514   if (!CASE_LOW (label))
5515     return 0;
5516
5517   /* If CASE_LOW_SEEN is not set, that means CASE_LOW did not appear
5518      when we did our enum->case scan.  Reset our scratch bit after.  */
5519   if (!CASE_LOW_SEEN (label))
5520     match_case_to_enum_1 (CASE_LOW (label), type, label);
5521   else
5522     CASE_LOW_SEEN (label) = 0;
5523
5524   /* If CASE_HIGH is non-null, we have a range.  If CASE_HIGH_SEEN is
5525      not set, that means that CASE_HIGH did not appear when we did our
5526      enum->case scan.  Reset our scratch bit after.  */
5527   if (CASE_HIGH (label))
5528     {
5529       if (!CASE_HIGH_SEEN (label))
5530         match_case_to_enum_1 (CASE_HIGH (label), type, label);
5531       else
5532         CASE_HIGH_SEEN (label) = 0;
5533     }
5534
5535   return 0;
5536 }
5537
5538 /* Handle -Wswitch*.  Called from the front end after parsing the
5539    switch construct.  */
5540 /* ??? Should probably be somewhere generic, since other languages
5541    besides C and C++ would want this.  At the moment, however, C/C++
5542    are the only tree-ssa languages that support enumerations at all,
5543    so the point is moot.  */
5544
5545 void
5546 c_do_switch_warnings (splay_tree cases, location_t switch_location,
5547                       tree type, tree cond)
5548 {
5549   splay_tree_node default_node;
5550   splay_tree_node node;
5551   tree chain;
5552
5553   if (!warn_switch && !warn_switch_enum && !warn_switch_default)
5554     return;
5555
5556   default_node = splay_tree_lookup (cases, (splay_tree_key) NULL);
5557   if (!default_node)
5558     warning_at (switch_location, OPT_Wswitch_default,
5559                 "switch missing default case");
5560
5561   /* From here on, we only care about about enumerated types.  */
5562   if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
5563     return;
5564
5565   /* From here on, we only care about -Wswitch and -Wswitch-enum.  */
5566   if (!warn_switch_enum && !warn_switch)
5567     return;
5568
5569   /* Check the cases.  Warn about case values which are not members of
5570      the enumerated type.  For -Wswitch-enum, or for -Wswitch when
5571      there is no default case, check that exactly all enumeration
5572      literals are covered by the cases.  */
5573
5574   /* Clearing COND if it is not an integer constant simplifies
5575      the tests inside the loop below.  */
5576   if (TREE_CODE (cond) != INTEGER_CST)
5577     cond = NULL_TREE;
5578
5579   /* The time complexity here is O(N*lg(N)) worst case, but for the
5580       common case of monotonically increasing enumerators, it is
5581       O(N), since the nature of the splay tree will keep the next
5582       element adjacent to the root at all times.  */
5583
5584   for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain))
5585     {
5586       tree value = TREE_VALUE (chain);
5587       if (TREE_CODE (value) == CONST_DECL)
5588         value = DECL_INITIAL (value);
5589       node = splay_tree_lookup (cases, (splay_tree_key) value);
5590       if (node)
5591         {
5592           /* Mark the CASE_LOW part of the case entry as seen.  */
5593           tree label = (tree) node->value;
5594           CASE_LOW_SEEN (label) = 1;
5595           continue;
5596         }
5597
5598       /* Even though there wasn't an exact match, there might be a
5599          case range which includes the enumerator's value.  */
5600       node = splay_tree_predecessor (cases, (splay_tree_key) value);
5601       if (node && CASE_HIGH ((tree) node->value))
5602         {
5603           tree label = (tree) node->value;
5604           int cmp = tree_int_cst_compare (CASE_HIGH (label), value);
5605           if (cmp >= 0)
5606             {
5607               /* If we match the upper bound exactly, mark the CASE_HIGH
5608                  part of the case entry as seen.  */
5609               if (cmp == 0)
5610                 CASE_HIGH_SEEN (label) = 1;
5611               continue;
5612             }
5613         }
5614
5615       /* We've now determined that this enumerated literal isn't
5616          handled by the case labels of the switch statement.  */
5617
5618       /* If the switch expression is a constant, we only really care
5619          about whether that constant is handled by the switch.  */
5620       if (cond && tree_int_cst_compare (cond, value))
5621         continue;
5622
5623       /* If there is a default_node, the only relevant option is
5624          Wswitch-enum.  Otherwise, if both are enabled then we prefer
5625          to warn using -Wswitch because -Wswitch is enabled by -Wall
5626          while -Wswitch-enum is explicit.  */
5627       warning_at (switch_location,
5628                   (default_node || !warn_switch
5629                    ? OPT_Wswitch_enum
5630                    : OPT_Wswitch),
5631                   "enumeration value %qE not handled in switch",
5632                   TREE_PURPOSE (chain));
5633     }
5634
5635   /* Warn if there are case expressions that don't correspond to
5636      enumerators.  This can occur since C and C++ don't enforce
5637      type-checking of assignments to enumeration variables.
5638
5639      The time complexity here is now always O(N) worst case, since
5640      we should have marked both the lower bound and upper bound of
5641      every disjoint case label, with CASE_LOW_SEEN and CASE_HIGH_SEEN
5642      above.  This scan also resets those fields.  */
5643
5644   splay_tree_foreach (cases, match_case_to_enum, type);
5645 }
5646
5647 /* Finish an expression taking the address of LABEL (an
5648    IDENTIFIER_NODE).  Returns an expression for the address.
5649
5650    LOC is the location for the expression returned.  */
5651
5652 tree
5653 finish_label_address_expr (tree label, location_t loc)
5654 {
5655   tree result;
5656
5657   pedwarn (input_location, OPT_pedantic, "taking the address of a label is non-standard");
5658
5659   if (label == error_mark_node)
5660     return error_mark_node;
5661
5662   label = lookup_label (label);
5663   if (label == NULL_TREE)
5664     result = null_pointer_node;
5665   else
5666     {
5667       TREE_USED (label) = 1;
5668       result = build1 (ADDR_EXPR, ptr_type_node, label);
5669       /* The current function is not necessarily uninlinable.
5670          Computed gotos are incompatible with inlining, but the value
5671          here could be used only in a diagnostic, for example.  */
5672       protected_set_expr_location (result, loc);
5673     }
5674
5675   return result;
5676 }
5677 \f
5678
5679 /* Given a boolean expression ARG, return a tree representing an increment
5680    or decrement (as indicated by CODE) of ARG.  The front end must check for
5681    invalid cases (e.g., decrement in C++).  */
5682 tree
5683 boolean_increment (enum tree_code code, tree arg)
5684 {
5685   tree val;
5686   tree true_res = build_int_cst (TREE_TYPE (arg), 1);
5687
5688   arg = stabilize_reference (arg);
5689   switch (code)
5690     {
5691     case PREINCREMENT_EXPR:
5692       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
5693       break;
5694     case POSTINCREMENT_EXPR:
5695       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
5696       arg = save_expr (arg);
5697       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
5698       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
5699       break;
5700     case PREDECREMENT_EXPR:
5701       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
5702                     invert_truthvalue_loc (input_location, arg));
5703       break;
5704     case POSTDECREMENT_EXPR:
5705       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
5706                     invert_truthvalue_loc (input_location, arg));
5707       arg = save_expr (arg);
5708       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
5709       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
5710       break;
5711     default:
5712       gcc_unreachable ();
5713     }
5714   TREE_SIDE_EFFECTS (val) = 1;
5715   return val;
5716 }
5717 \f
5718 /* Built-in macros for stddef.h and stdint.h, that require macros
5719    defined in this file.  */
5720 void
5721 c_stddef_cpp_builtins(void)
5722 {
5723   builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0);
5724   builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0);
5725   builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0);
5726   builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0);
5727   builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0);
5728   builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0);
5729   builtin_define_with_value ("__CHAR16_TYPE__", CHAR16_TYPE, 0);
5730   builtin_define_with_value ("__CHAR32_TYPE__", CHAR32_TYPE, 0);
5731   if (SIG_ATOMIC_TYPE)
5732     builtin_define_with_value ("__SIG_ATOMIC_TYPE__", SIG_ATOMIC_TYPE, 0);
5733   if (INT8_TYPE)
5734     builtin_define_with_value ("__INT8_TYPE__", INT8_TYPE, 0);
5735   if (INT16_TYPE)
5736     builtin_define_with_value ("__INT16_TYPE__", INT16_TYPE, 0);
5737   if (INT32_TYPE)
5738     builtin_define_with_value ("__INT32_TYPE__", INT32_TYPE, 0);
5739   if (INT64_TYPE)
5740     builtin_define_with_value ("__INT64_TYPE__", INT64_TYPE, 0);
5741   if (UINT8_TYPE)
5742     builtin_define_with_value ("__UINT8_TYPE__", UINT8_TYPE, 0);
5743   if (UINT16_TYPE)
5744     builtin_define_with_value ("__UINT16_TYPE__", UINT16_TYPE, 0);
5745   if (UINT32_TYPE)
5746     builtin_define_with_value ("__UINT32_TYPE__", UINT32_TYPE, 0);
5747   if (UINT64_TYPE)
5748     builtin_define_with_value ("__UINT64_TYPE__", UINT64_TYPE, 0);
5749   if (INT_LEAST8_TYPE)
5750     builtin_define_with_value ("__INT_LEAST8_TYPE__", INT_LEAST8_TYPE, 0);
5751   if (INT_LEAST16_TYPE)
5752     builtin_define_with_value ("__INT_LEAST16_TYPE__", INT_LEAST16_TYPE, 0);
5753   if (INT_LEAST32_TYPE)
5754     builtin_define_with_value ("__INT_LEAST32_TYPE__", INT_LEAST32_TYPE, 0);
5755   if (INT_LEAST64_TYPE)
5756     builtin_define_with_value ("__INT_LEAST64_TYPE__", INT_LEAST64_TYPE, 0);
5757   if (UINT_LEAST8_TYPE)
5758     builtin_define_with_value ("__UINT_LEAST8_TYPE__", UINT_LEAST8_TYPE, 0);
5759   if (UINT_LEAST16_TYPE)
5760     builtin_define_with_value ("__UINT_LEAST16_TYPE__", UINT_LEAST16_TYPE, 0);
5761   if (UINT_LEAST32_TYPE)
5762     builtin_define_with_value ("__UINT_LEAST32_TYPE__", UINT_LEAST32_TYPE, 0);
5763   if (UINT_LEAST64_TYPE)
5764     builtin_define_with_value ("__UINT_LEAST64_TYPE__", UINT_LEAST64_TYPE, 0);
5765   if (INT_FAST8_TYPE)
5766     builtin_define_with_value ("__INT_FAST8_TYPE__", INT_FAST8_TYPE, 0);
5767   if (INT_FAST16_TYPE)
5768     builtin_define_with_value ("__INT_FAST16_TYPE__", INT_FAST16_TYPE, 0);
5769   if (INT_FAST32_TYPE)
5770     builtin_define_with_value ("__INT_FAST32_TYPE__", INT_FAST32_TYPE, 0);
5771   if (INT_FAST64_TYPE)
5772     builtin_define_with_value ("__INT_FAST64_TYPE__", INT_FAST64_TYPE, 0);
5773   if (UINT_FAST8_TYPE)
5774     builtin_define_with_value ("__UINT_FAST8_TYPE__", UINT_FAST8_TYPE, 0);
5775   if (UINT_FAST16_TYPE)
5776     builtin_define_with_value ("__UINT_FAST16_TYPE__", UINT_FAST16_TYPE, 0);
5777   if (UINT_FAST32_TYPE)
5778     builtin_define_with_value ("__UINT_FAST32_TYPE__", UINT_FAST32_TYPE, 0);
5779   if (UINT_FAST64_TYPE)
5780     builtin_define_with_value ("__UINT_FAST64_TYPE__", UINT_FAST64_TYPE, 0);
5781   if (INTPTR_TYPE)
5782     builtin_define_with_value ("__INTPTR_TYPE__", INTPTR_TYPE, 0);
5783   if (UINTPTR_TYPE)
5784     builtin_define_with_value ("__UINTPTR_TYPE__", UINTPTR_TYPE, 0);
5785 }
5786
5787 static void
5788 c_init_attributes (void)
5789 {
5790   /* Fill in the built_in_attributes array.  */
5791 #define DEF_ATTR_NULL_TREE(ENUM)                                \
5792   built_in_attributes[(int) ENUM] = NULL_TREE;
5793 #define DEF_ATTR_INT(ENUM, VALUE)                               \
5794   built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
5795 #define DEF_ATTR_IDENT(ENUM, STRING)                            \
5796   built_in_attributes[(int) ENUM] = get_identifier (STRING);
5797 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
5798   built_in_attributes[(int) ENUM]                       \
5799     = tree_cons (built_in_attributes[(int) PURPOSE],    \
5800                  built_in_attributes[(int) VALUE],      \
5801                  built_in_attributes[(int) CHAIN]);
5802 #include "builtin-attrs.def"
5803 #undef DEF_ATTR_NULL_TREE
5804 #undef DEF_ATTR_INT
5805 #undef DEF_ATTR_IDENT
5806 #undef DEF_ATTR_TREE_LIST
5807 }
5808
5809 /* Attribute handlers common to C front ends.  */
5810
5811 /* Handle a "packed" attribute; arguments as in
5812    struct attribute_spec.handler.  */
5813
5814 static tree
5815 handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5816                          int flags, bool *no_add_attrs)
5817 {
5818   if (TYPE_P (*node))
5819     {
5820       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5821         *node = build_variant_type_copy (*node);
5822       TYPE_PACKED (*node) = 1;
5823     }
5824   else if (TREE_CODE (*node) == FIELD_DECL)
5825     {
5826       if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT
5827           /* Still pack bitfields.  */
5828           && ! DECL_INITIAL (*node))
5829         warning (OPT_Wattributes,
5830                  "%qE attribute ignored for field of type %qT",
5831                  name, TREE_TYPE (*node));
5832       else
5833         DECL_PACKED (*node) = 1;
5834     }
5835   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
5836      used for DECL_REGISTER.  It wouldn't mean anything anyway.
5837      We can't set DECL_PACKED on the type of a TYPE_DECL, because
5838      that changes what the typedef is typing.  */
5839   else
5840     {
5841       warning (OPT_Wattributes, "%qE attribute ignored", name);
5842       *no_add_attrs = true;
5843     }
5844
5845   return NULL_TREE;
5846 }
5847
5848 /* Handle a "nocommon" attribute; arguments as in
5849    struct attribute_spec.handler.  */
5850
5851 static tree
5852 handle_nocommon_attribute (tree *node, tree name,
5853                            tree ARG_UNUSED (args),
5854                            int ARG_UNUSED (flags), bool *no_add_attrs)
5855 {
5856   if (TREE_CODE (*node) == VAR_DECL)
5857     DECL_COMMON (*node) = 0;
5858   else
5859     {
5860       warning (OPT_Wattributes, "%qE attribute ignored", name);
5861       *no_add_attrs = true;
5862     }
5863
5864   return NULL_TREE;
5865 }
5866
5867 /* Handle a "common" attribute; arguments as in
5868    struct attribute_spec.handler.  */
5869
5870 static tree
5871 handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5872                          int ARG_UNUSED (flags), bool *no_add_attrs)
5873 {
5874   if (TREE_CODE (*node) == VAR_DECL)
5875     DECL_COMMON (*node) = 1;
5876   else
5877     {
5878       warning (OPT_Wattributes, "%qE attribute ignored", name);
5879       *no_add_attrs = true;
5880     }
5881
5882   return NULL_TREE;
5883 }
5884
5885 /* Handle a "noreturn" attribute; arguments as in
5886    struct attribute_spec.handler.  */
5887
5888 static tree
5889 handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5890                            int ARG_UNUSED (flags), bool *no_add_attrs)
5891 {
5892   tree type = TREE_TYPE (*node);
5893
5894   /* See FIXME comment in c_common_attribute_table.  */
5895   if (TREE_CODE (*node) == FUNCTION_DECL)
5896     TREE_THIS_VOLATILE (*node) = 1;
5897   else if (TREE_CODE (type) == POINTER_TYPE
5898            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
5899     TREE_TYPE (*node)
5900       = build_pointer_type
5901         (build_type_variant (TREE_TYPE (type),
5902                              TYPE_READONLY (TREE_TYPE (type)), 1));
5903   else
5904     {
5905       warning (OPT_Wattributes, "%qE attribute ignored", name);
5906       *no_add_attrs = true;
5907     }
5908
5909   return NULL_TREE;
5910 }
5911
5912 /* Handle a "hot" and attribute; arguments as in
5913    struct attribute_spec.handler.  */
5914
5915 static tree
5916 handle_hot_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5917                       int ARG_UNUSED (flags), bool *no_add_attrs)
5918 {
5919   if (TREE_CODE (*node) == FUNCTION_DECL)
5920     {
5921       if (lookup_attribute ("cold", DECL_ATTRIBUTES (*node)) != NULL)
5922         {
5923           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
5924                    name, "cold");
5925           *no_add_attrs = true;
5926         }
5927       /* Most of the rest of the hot processing is done later with
5928          lookup_attribute.  */
5929     }
5930   else
5931     {
5932       warning (OPT_Wattributes, "%qE attribute ignored", name);
5933       *no_add_attrs = true;
5934     }
5935
5936   return NULL_TREE;
5937 }
5938 /* Handle a "cold" and attribute; arguments as in
5939    struct attribute_spec.handler.  */
5940
5941 static tree
5942 handle_cold_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5943                        int ARG_UNUSED (flags), bool *no_add_attrs)
5944 {
5945   if (TREE_CODE (*node) == FUNCTION_DECL)
5946     {
5947       if (lookup_attribute ("hot", DECL_ATTRIBUTES (*node)) != NULL)
5948         {
5949           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
5950                    name, "hot");
5951           *no_add_attrs = true;
5952         }
5953       /* Most of the rest of the cold processing is done later with
5954          lookup_attribute.  */
5955     }
5956   else
5957     {
5958       warning (OPT_Wattributes, "%qE attribute ignored", name);
5959       *no_add_attrs = true;
5960     }
5961
5962   return NULL_TREE;
5963 }
5964
5965 /* Handle a "noinline" attribute; arguments as in
5966    struct attribute_spec.handler.  */
5967
5968 static tree
5969 handle_noinline_attribute (tree *node, tree name,
5970                            tree ARG_UNUSED (args),
5971                            int ARG_UNUSED (flags), bool *no_add_attrs)
5972 {
5973   if (TREE_CODE (*node) == FUNCTION_DECL)
5974     DECL_UNINLINABLE (*node) = 1;
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 "noclone" attribute; arguments as in
5985    struct attribute_spec.handler.  */
5986
5987 static tree
5988 handle_noclone_attribute (tree *node, tree name,
5989                           tree ARG_UNUSED (args),
5990                           int ARG_UNUSED (flags), bool *no_add_attrs)
5991 {
5992   if (TREE_CODE (*node) != FUNCTION_DECL)
5993     {
5994       warning (OPT_Wattributes, "%qE attribute ignored", name);
5995       *no_add_attrs = true;
5996     }
5997
5998   return NULL_TREE;
5999 }
6000
6001 /* Handle a "always_inline" attribute; arguments as in
6002    struct attribute_spec.handler.  */
6003
6004 static tree
6005 handle_always_inline_attribute (tree *node, tree name,
6006                                 tree ARG_UNUSED (args),
6007                                 int ARG_UNUSED (flags),
6008                                 bool *no_add_attrs)
6009 {
6010   if (TREE_CODE (*node) == FUNCTION_DECL)
6011     {
6012       /* Set the attribute and mark it for disregarding inline
6013          limits.  */
6014       DECL_DISREGARD_INLINE_LIMITS (*node) = 1;
6015     }
6016   else
6017     {
6018       warning (OPT_Wattributes, "%qE attribute ignored", name);
6019       *no_add_attrs = true;
6020     }
6021
6022   return NULL_TREE;
6023 }
6024
6025 /* Handle a "gnu_inline" attribute; arguments as in
6026    struct attribute_spec.handler.  */
6027
6028 static tree
6029 handle_gnu_inline_attribute (tree *node, tree name,
6030                              tree ARG_UNUSED (args),
6031                              int ARG_UNUSED (flags),
6032                              bool *no_add_attrs)
6033 {
6034   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
6035     {
6036       /* Do nothing else, just set the attribute.  We'll get at
6037          it later with lookup_attribute.  */
6038     }
6039   else
6040     {
6041       warning (OPT_Wattributes, "%qE attribute ignored", name);
6042       *no_add_attrs = true;
6043     }
6044
6045   return NULL_TREE;
6046 }
6047
6048 /* Handle an "artificial" attribute; arguments as in
6049    struct attribute_spec.handler.  */
6050
6051 static tree
6052 handle_artificial_attribute (tree *node, tree name,
6053                              tree ARG_UNUSED (args),
6054                              int ARG_UNUSED (flags),
6055                              bool *no_add_attrs)
6056 {
6057   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
6058     {
6059       /* Do nothing else, just set the attribute.  We'll get at
6060          it later with lookup_attribute.  */
6061     }
6062   else
6063     {
6064       warning (OPT_Wattributes, "%qE attribute ignored", name);
6065       *no_add_attrs = true;
6066     }
6067
6068   return NULL_TREE;
6069 }
6070
6071 /* Handle a "flatten" attribute; arguments as in
6072    struct attribute_spec.handler.  */
6073
6074 static tree
6075 handle_flatten_attribute (tree *node, tree name,
6076                           tree args ATTRIBUTE_UNUSED,
6077                           int flags ATTRIBUTE_UNUSED, bool *no_add_attrs)
6078 {
6079   if (TREE_CODE (*node) == FUNCTION_DECL)
6080     /* Do nothing else, just set the attribute.  We'll get at
6081        it later with lookup_attribute.  */
6082     ;
6083   else
6084     {
6085       warning (OPT_Wattributes, "%qE attribute ignored", name);
6086       *no_add_attrs = true;
6087     }
6088
6089   return NULL_TREE;
6090 }
6091
6092 /* Handle a "warning" or "error" attribute; arguments as in
6093    struct attribute_spec.handler.  */
6094
6095 static tree
6096 handle_error_attribute (tree *node, tree name, tree args,
6097                         int ARG_UNUSED (flags), bool *no_add_attrs)
6098 {
6099   if (TREE_CODE (*node) == FUNCTION_DECL
6100       || TREE_CODE (TREE_VALUE (args)) == STRING_CST)
6101     /* Do nothing else, just set the attribute.  We'll get at
6102        it later with lookup_attribute.  */
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 "used" attribute; arguments as in
6114    struct attribute_spec.handler.  */
6115
6116 static tree
6117 handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
6118                        int ARG_UNUSED (flags), bool *no_add_attrs)
6119 {
6120   tree node = *pnode;
6121
6122   if (TREE_CODE (node) == FUNCTION_DECL
6123       || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node)))
6124     {
6125       TREE_USED (node) = 1;
6126       DECL_PRESERVE_P (node) = 1;
6127     }
6128   else
6129     {
6130       warning (OPT_Wattributes, "%qE attribute ignored", name);
6131       *no_add_attrs = true;
6132     }
6133
6134   return NULL_TREE;
6135 }
6136
6137 /* Handle a "unused" attribute; arguments as in
6138    struct attribute_spec.handler.  */
6139
6140 static tree
6141 handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6142                          int flags, bool *no_add_attrs)
6143 {
6144   if (DECL_P (*node))
6145     {
6146       tree decl = *node;
6147
6148       if (TREE_CODE (decl) == PARM_DECL
6149           || TREE_CODE (decl) == VAR_DECL
6150           || TREE_CODE (decl) == FUNCTION_DECL
6151           || TREE_CODE (decl) == LABEL_DECL
6152           || TREE_CODE (decl) == TYPE_DECL)
6153         TREE_USED (decl) = 1;
6154       else
6155         {
6156           warning (OPT_Wattributes, "%qE attribute ignored", name);
6157           *no_add_attrs = true;
6158         }
6159     }
6160   else
6161     {
6162       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6163         *node = build_variant_type_copy (*node);
6164       TREE_USED (*node) = 1;
6165     }
6166
6167   return NULL_TREE;
6168 }
6169
6170 /* Handle a "externally_visible" attribute; arguments as in
6171    struct attribute_spec.handler.  */
6172
6173 static tree
6174 handle_externally_visible_attribute (tree *pnode, tree name,
6175                                      tree ARG_UNUSED (args),
6176                                      int ARG_UNUSED (flags),
6177                                      bool *no_add_attrs)
6178 {
6179   tree node = *pnode;
6180
6181   if (TREE_CODE (node) == FUNCTION_DECL || TREE_CODE (node) == VAR_DECL)
6182     {
6183       if ((!TREE_STATIC (node) && TREE_CODE (node) != FUNCTION_DECL
6184            && !DECL_EXTERNAL (node)) || !TREE_PUBLIC (node))
6185         {
6186           warning (OPT_Wattributes,
6187                    "%qE attribute have effect only on public objects", name);
6188           *no_add_attrs = true;
6189         }
6190     }
6191   else
6192     {
6193       warning (OPT_Wattributes, "%qE attribute ignored", name);
6194       *no_add_attrs = true;
6195     }
6196
6197   return NULL_TREE;
6198 }
6199
6200 /* Handle a "const" attribute; arguments as in
6201    struct attribute_spec.handler.  */
6202
6203 static tree
6204 handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6205                         int ARG_UNUSED (flags), bool *no_add_attrs)
6206 {
6207   tree type = TREE_TYPE (*node);
6208
6209   /* See FIXME comment on noreturn in c_common_attribute_table.  */
6210   if (TREE_CODE (*node) == FUNCTION_DECL)
6211     TREE_READONLY (*node) = 1;
6212   else if (TREE_CODE (type) == POINTER_TYPE
6213            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
6214     TREE_TYPE (*node)
6215       = build_pointer_type
6216         (build_type_variant (TREE_TYPE (type), 1,
6217                              TREE_THIS_VOLATILE (TREE_TYPE (type))));
6218   else
6219     {
6220       warning (OPT_Wattributes, "%qE attribute ignored", name);
6221       *no_add_attrs = true;
6222     }
6223
6224   return NULL_TREE;
6225 }
6226
6227 /* Handle a "transparent_union" attribute; arguments as in
6228    struct attribute_spec.handler.  */
6229
6230 static tree
6231 handle_transparent_union_attribute (tree *node, tree name,
6232                                     tree ARG_UNUSED (args), int flags,
6233                                     bool *no_add_attrs)
6234 {
6235   tree type;
6236
6237   *no_add_attrs = true;
6238
6239   if (TREE_CODE (*node) == TYPE_DECL)
6240     node = &TREE_TYPE (*node);
6241   type = *node;
6242
6243   if (TREE_CODE (type) == UNION_TYPE)
6244     {
6245       /* When IN_PLACE is set, leave the check for FIELDS and MODE to
6246          the code in finish_struct.  */
6247       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6248         {
6249           if (TYPE_FIELDS (type) == NULL_TREE
6250               || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type)))
6251             goto ignored;
6252
6253           /* A type variant isn't good enough, since we don't a cast
6254              to such a type removed as a no-op.  */
6255           *node = type = build_duplicate_type (type);
6256         }
6257
6258       TYPE_TRANSPARENT_AGGR (type) = 1;
6259       return NULL_TREE;
6260     }
6261
6262  ignored:
6263   warning (OPT_Wattributes, "%qE attribute ignored", name);
6264   return NULL_TREE;
6265 }
6266
6267 /* Subroutine of handle_{con,de}structor_attribute.  Evaluate ARGS to
6268    get the requested priority for a constructor or destructor,
6269    possibly issuing diagnostics for invalid or reserved
6270    priorities.  */
6271
6272 static priority_type
6273 get_priority (tree args, bool is_destructor)
6274 {
6275   HOST_WIDE_INT pri;
6276   tree arg;
6277
6278   if (!args)
6279     return DEFAULT_INIT_PRIORITY;
6280
6281   if (!SUPPORTS_INIT_PRIORITY)
6282     {
6283       if (is_destructor)
6284         error ("destructor priorities are not supported");
6285       else
6286         error ("constructor priorities are not supported");
6287       return DEFAULT_INIT_PRIORITY;
6288     }
6289
6290   arg = TREE_VALUE (args);
6291   if (!host_integerp (arg, /*pos=*/0)
6292       || !INTEGRAL_TYPE_P (TREE_TYPE (arg)))
6293     goto invalid;
6294
6295   pri = tree_low_cst (TREE_VALUE (args), /*pos=*/0);
6296   if (pri < 0 || pri > MAX_INIT_PRIORITY)
6297     goto invalid;
6298
6299   if (pri <= MAX_RESERVED_INIT_PRIORITY)
6300     {
6301       if (is_destructor)
6302         warning (0,
6303                  "destructor priorities from 0 to %d are reserved "
6304                  "for the implementation",
6305                  MAX_RESERVED_INIT_PRIORITY);
6306       else
6307         warning (0,
6308                  "constructor priorities from 0 to %d are reserved "
6309                  "for the implementation",
6310                  MAX_RESERVED_INIT_PRIORITY);
6311     }
6312   return pri;
6313
6314  invalid:
6315   if (is_destructor)
6316     error ("destructor priorities must be integers from 0 to %d inclusive",
6317            MAX_INIT_PRIORITY);
6318   else
6319     error ("constructor priorities must be integers from 0 to %d inclusive",
6320            MAX_INIT_PRIORITY);
6321   return DEFAULT_INIT_PRIORITY;
6322 }
6323
6324 /* Handle a "constructor" attribute; arguments as in
6325    struct attribute_spec.handler.  */
6326
6327 static tree
6328 handle_constructor_attribute (tree *node, tree name, tree args,
6329                               int ARG_UNUSED (flags),
6330                               bool *no_add_attrs)
6331 {
6332   tree decl = *node;
6333   tree type = TREE_TYPE (decl);
6334
6335   if (TREE_CODE (decl) == FUNCTION_DECL
6336       && TREE_CODE (type) == FUNCTION_TYPE
6337       && decl_function_context (decl) == 0)
6338     {
6339       priority_type priority;
6340       DECL_STATIC_CONSTRUCTOR (decl) = 1;
6341       priority = get_priority (args, /*is_destructor=*/false);
6342       SET_DECL_INIT_PRIORITY (decl, priority);
6343       TREE_USED (decl) = 1;
6344     }
6345   else
6346     {
6347       warning (OPT_Wattributes, "%qE attribute ignored", name);
6348       *no_add_attrs = true;
6349     }
6350
6351   return NULL_TREE;
6352 }
6353
6354 /* Handle a "destructor" attribute; arguments as in
6355    struct attribute_spec.handler.  */
6356
6357 static tree
6358 handle_destructor_attribute (tree *node, tree name, tree args,
6359                              int ARG_UNUSED (flags),
6360                              bool *no_add_attrs)
6361 {
6362   tree decl = *node;
6363   tree type = TREE_TYPE (decl);
6364
6365   if (TREE_CODE (decl) == FUNCTION_DECL
6366       && TREE_CODE (type) == FUNCTION_TYPE
6367       && decl_function_context (decl) == 0)
6368     {
6369       priority_type priority;
6370       DECL_STATIC_DESTRUCTOR (decl) = 1;
6371       priority = get_priority (args, /*is_destructor=*/true);
6372       SET_DECL_FINI_PRIORITY (decl, priority);
6373       TREE_USED (decl) = 1;
6374     }
6375   else
6376     {
6377       warning (OPT_Wattributes, "%qE attribute ignored", name);
6378       *no_add_attrs = true;
6379     }
6380
6381   return NULL_TREE;
6382 }
6383
6384 /* Handle a "mode" attribute; arguments as in
6385    struct attribute_spec.handler.  */
6386
6387 static tree
6388 handle_mode_attribute (tree *node, tree name, tree args,
6389                        int ARG_UNUSED (flags), bool *no_add_attrs)
6390 {
6391   tree type = *node;
6392   tree ident = TREE_VALUE (args);
6393
6394   *no_add_attrs = true;
6395
6396   if (TREE_CODE (ident) != IDENTIFIER_NODE)
6397     warning (OPT_Wattributes, "%qE attribute ignored", name);
6398   else
6399     {
6400       int j;
6401       const char *p = IDENTIFIER_POINTER (ident);
6402       int len = strlen (p);
6403       enum machine_mode mode = VOIDmode;
6404       tree typefm;
6405       bool valid_mode;
6406
6407       if (len > 4 && p[0] == '_' && p[1] == '_'
6408           && p[len - 1] == '_' && p[len - 2] == '_')
6409         {
6410           char *newp = (char *) alloca (len - 1);
6411
6412           strcpy (newp, &p[2]);
6413           newp[len - 4] = '\0';
6414           p = newp;
6415         }
6416
6417       /* Change this type to have a type with the specified mode.
6418          First check for the special modes.  */
6419       if (!strcmp (p, "byte"))
6420         mode = byte_mode;
6421       else if (!strcmp (p, "word"))
6422         mode = word_mode;
6423       else if (!strcmp (p, "pointer"))
6424         mode = ptr_mode;
6425       else if (!strcmp (p, "libgcc_cmp_return"))
6426         mode = targetm.libgcc_cmp_return_mode ();
6427       else if (!strcmp (p, "libgcc_shift_count"))
6428         mode = targetm.libgcc_shift_count_mode ();
6429       else if (!strcmp (p, "unwind_word"))
6430         mode = targetm.unwind_word_mode ();
6431       else
6432         for (j = 0; j < NUM_MACHINE_MODES; j++)
6433           if (!strcmp (p, GET_MODE_NAME (j)))
6434             {
6435               mode = (enum machine_mode) j;
6436               break;
6437             }
6438
6439       if (mode == VOIDmode)
6440         {
6441           error ("unknown machine mode %qE", ident);
6442           return NULL_TREE;
6443         }
6444
6445       valid_mode = false;
6446       switch (GET_MODE_CLASS (mode))
6447         {
6448         case MODE_INT:
6449         case MODE_PARTIAL_INT:
6450         case MODE_FLOAT:
6451         case MODE_DECIMAL_FLOAT:
6452         case MODE_FRACT:
6453         case MODE_UFRACT:
6454         case MODE_ACCUM:
6455         case MODE_UACCUM:
6456           valid_mode = targetm.scalar_mode_supported_p (mode);
6457           break;
6458
6459         case MODE_COMPLEX_INT:
6460         case MODE_COMPLEX_FLOAT:
6461           valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode));
6462           break;
6463
6464         case MODE_VECTOR_INT:
6465         case MODE_VECTOR_FLOAT:
6466         case MODE_VECTOR_FRACT:
6467         case MODE_VECTOR_UFRACT:
6468         case MODE_VECTOR_ACCUM:
6469         case MODE_VECTOR_UACCUM:
6470           warning (OPT_Wattributes, "specifying vector types with "
6471                    "__attribute__ ((mode)) is deprecated");
6472           warning (OPT_Wattributes,
6473                    "use __attribute__ ((vector_size)) instead");
6474           valid_mode = vector_mode_valid_p (mode);
6475           break;
6476
6477         default:
6478           break;
6479         }
6480       if (!valid_mode)
6481         {
6482           error ("unable to emulate %qs", p);
6483           return NULL_TREE;
6484         }
6485
6486       if (POINTER_TYPE_P (type))
6487         {
6488           addr_space_t as = TYPE_ADDR_SPACE (TREE_TYPE (type));
6489           tree (*fn)(tree, enum machine_mode, bool);
6490
6491           if (!targetm.addr_space.valid_pointer_mode (mode, as))
6492             {
6493               error ("invalid pointer mode %qs", p);
6494               return NULL_TREE;
6495             }
6496
6497           if (TREE_CODE (type) == POINTER_TYPE)
6498             fn = build_pointer_type_for_mode;
6499           else
6500             fn = build_reference_type_for_mode;
6501           typefm = fn (TREE_TYPE (type), mode, false);
6502         }
6503       else
6504         {
6505           /* For fixed-point modes, we need to test if the signness of type
6506              and the machine mode are consistent.  */
6507           if (ALL_FIXED_POINT_MODE_P (mode)
6508               && TYPE_UNSIGNED (type) != UNSIGNED_FIXED_POINT_MODE_P (mode))
6509             {
6510               error ("signness of type and machine mode %qs don't match", p);
6511               return NULL_TREE;
6512             }
6513           /* For fixed-point modes, we need to pass saturating info.  */
6514           typefm = lang_hooks.types.type_for_mode (mode,
6515                         ALL_FIXED_POINT_MODE_P (mode) ? TYPE_SATURATING (type)
6516                                                       : TYPE_UNSIGNED (type));
6517         }
6518
6519       if (typefm == NULL_TREE)
6520         {
6521           error ("no data type for mode %qs", p);
6522           return NULL_TREE;
6523         }
6524       else if (TREE_CODE (type) == ENUMERAL_TYPE)
6525         {
6526           /* For enumeral types, copy the precision from the integer
6527              type returned above.  If not an INTEGER_TYPE, we can't use
6528              this mode for this type.  */
6529           if (TREE_CODE (typefm) != INTEGER_TYPE)
6530             {
6531               error ("cannot use mode %qs for enumeral types", p);
6532               return NULL_TREE;
6533             }
6534
6535           if (flags & ATTR_FLAG_TYPE_IN_PLACE)
6536             {
6537               TYPE_PRECISION (type) = TYPE_PRECISION (typefm);
6538               typefm = type;
6539             }
6540           else
6541             {
6542               /* We cannot build a type variant, as there's code that assumes
6543                  that TYPE_MAIN_VARIANT has the same mode.  This includes the
6544                  debug generators.  Instead, create a subrange type.  This
6545                  results in all of the enumeral values being emitted only once
6546                  in the original, and the subtype gets them by reference.  */
6547               if (TYPE_UNSIGNED (type))
6548                 typefm = make_unsigned_type (TYPE_PRECISION (typefm));
6549               else
6550                 typefm = make_signed_type (TYPE_PRECISION (typefm));
6551               TREE_TYPE (typefm) = type;
6552             }
6553         }
6554       else if (VECTOR_MODE_P (mode)
6555                ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm))
6556                : TREE_CODE (type) != TREE_CODE (typefm))
6557         {
6558           error ("mode %qs applied to inappropriate type", p);
6559           return NULL_TREE;
6560         }
6561
6562       *node = typefm;
6563     }
6564
6565   return NULL_TREE;
6566 }
6567
6568 /* Handle a "section" attribute; arguments as in
6569    struct attribute_spec.handler.  */
6570
6571 static tree
6572 handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6573                           int ARG_UNUSED (flags), bool *no_add_attrs)
6574 {
6575   tree decl = *node;
6576
6577   if (targetm.have_named_sections)
6578     {
6579       user_defined_section_attribute = true;
6580
6581       if ((TREE_CODE (decl) == FUNCTION_DECL
6582            || TREE_CODE (decl) == VAR_DECL)
6583           && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
6584         {
6585           if (TREE_CODE (decl) == VAR_DECL
6586               && current_function_decl != NULL_TREE
6587               && !TREE_STATIC (decl))
6588             {
6589               error_at (DECL_SOURCE_LOCATION (decl),
6590                         "section attribute cannot be specified for "
6591                         "local variables");
6592               *no_add_attrs = true;
6593             }
6594
6595           /* The decl may have already been given a section attribute
6596              from a previous declaration.  Ensure they match.  */
6597           else if (DECL_SECTION_NAME (decl) != NULL_TREE
6598                    && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
6599                               TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
6600             {
6601               error ("section of %q+D conflicts with previous declaration",
6602                      *node);
6603               *no_add_attrs = true;
6604             }
6605           else if (TREE_CODE (decl) == VAR_DECL
6606                    && !targetm.have_tls && targetm.emutls.tmpl_section
6607                    && DECL_THREAD_LOCAL_P (decl))
6608             {
6609               error ("section of %q+D cannot be overridden", *node);
6610               *no_add_attrs = true;
6611             }
6612           else
6613             DECL_SECTION_NAME (decl) = TREE_VALUE (args);
6614         }
6615       else
6616         {
6617           error ("section attribute not allowed for %q+D", *node);
6618           *no_add_attrs = true;
6619         }
6620     }
6621   else
6622     {
6623       error_at (DECL_SOURCE_LOCATION (*node),
6624                 "section attributes are not supported for this target");
6625       *no_add_attrs = true;
6626     }
6627
6628   return NULL_TREE;
6629 }
6630
6631 /* Handle a "aligned" attribute; arguments as in
6632    struct attribute_spec.handler.  */
6633
6634 static tree
6635 handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6636                           int flags, bool *no_add_attrs)
6637 {
6638   tree decl = NULL_TREE;
6639   tree *type = NULL;
6640   int is_type = 0;
6641   tree align_expr = (args ? TREE_VALUE (args)
6642                      : size_int (ATTRIBUTE_ALIGNED_VALUE / BITS_PER_UNIT));
6643   int i;
6644
6645   if (DECL_P (*node))
6646     {
6647       decl = *node;
6648       type = &TREE_TYPE (decl);
6649       is_type = TREE_CODE (*node) == TYPE_DECL;
6650     }
6651   else if (TYPE_P (*node))
6652     type = node, is_type = 1;
6653
6654   if (TREE_CODE (align_expr) != INTEGER_CST)
6655     {
6656       error ("requested alignment is not a constant");
6657       *no_add_attrs = true;
6658     }
6659   else if ((i = tree_log2 (align_expr)) == -1)
6660     {
6661       error ("requested alignment is not a power of 2");
6662       *no_add_attrs = true;
6663     }
6664   else if (i >= HOST_BITS_PER_INT - BITS_PER_UNIT_LOG)
6665     {
6666       error ("requested alignment is too large");
6667       *no_add_attrs = true;
6668     }
6669   else if (is_type)
6670     {
6671       /* If we have a TYPE_DECL, then copy the type, so that we
6672          don't accidentally modify a builtin type.  See pushdecl.  */
6673       if (decl && TREE_TYPE (decl) != error_mark_node
6674           && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
6675         {
6676           tree tt = TREE_TYPE (decl);
6677           *type = build_variant_type_copy (*type);
6678           DECL_ORIGINAL_TYPE (decl) = tt;
6679           TYPE_NAME (*type) = decl;
6680           TREE_USED (*type) = TREE_USED (decl);
6681           TREE_TYPE (decl) = *type;
6682         }
6683       else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6684         *type = build_variant_type_copy (*type);
6685
6686       TYPE_ALIGN (*type) = (1U << i) * BITS_PER_UNIT;
6687       TYPE_USER_ALIGN (*type) = 1;
6688     }
6689   else if (! VAR_OR_FUNCTION_DECL_P (decl)
6690            && TREE_CODE (decl) != FIELD_DECL)
6691     {
6692       error ("alignment may not be specified for %q+D", decl);
6693       *no_add_attrs = true;
6694     }
6695   else if (TREE_CODE (decl) == FUNCTION_DECL
6696            && DECL_ALIGN (decl) > (1U << i) * BITS_PER_UNIT)
6697     {
6698       if (DECL_USER_ALIGN (decl))
6699         error ("alignment for %q+D was previously specified as %d "
6700                "and may not be decreased", decl,
6701                DECL_ALIGN (decl) / BITS_PER_UNIT);
6702       else
6703         error ("alignment for %q+D must be at least %d", decl,
6704                DECL_ALIGN (decl) / BITS_PER_UNIT);
6705       *no_add_attrs = true;
6706     }
6707   else
6708     {
6709       DECL_ALIGN (decl) = (1U << i) * BITS_PER_UNIT;
6710       DECL_USER_ALIGN (decl) = 1;
6711     }
6712
6713   return NULL_TREE;
6714 }
6715
6716 /* Handle a "weak" attribute; arguments as in
6717    struct attribute_spec.handler.  */
6718
6719 static tree
6720 handle_weak_attribute (tree *node, tree name,
6721                        tree ARG_UNUSED (args),
6722                        int ARG_UNUSED (flags),
6723                        bool * ARG_UNUSED (no_add_attrs))
6724 {
6725   if (TREE_CODE (*node) == FUNCTION_DECL
6726       && DECL_DECLARED_INLINE_P (*node))
6727     {
6728       error ("inline function %q+D cannot be declared weak", *node);
6729       *no_add_attrs = true;
6730     }
6731   else if (TREE_CODE (*node) == FUNCTION_DECL
6732            || TREE_CODE (*node) == VAR_DECL)
6733     declare_weak (*node);
6734   else
6735     warning (OPT_Wattributes, "%qE attribute ignored", name);
6736
6737   return NULL_TREE;
6738 }
6739
6740 /* Handle an "ifunc" attribute; arguments as in
6741    struct attribute_spec.handler.  */
6742
6743 static tree
6744 handle_ifunc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6745                         int ARG_UNUSED (flags), bool *no_add_attrs)
6746 {
6747   tree decl = *node;
6748
6749   if (TREE_CODE (decl) == FUNCTION_DECL)
6750     {
6751       /* This is an IFUNC DECL.  */
6752       DECL_IS_IFUNC (decl) = 1;
6753       DECL_UNINLINABLE (decl) = 1;
6754       TREE_USED (decl) = 1;
6755       DECL_PRESERVE_P (decl) = 1;
6756     }
6757   else
6758     {
6759       warning (OPT_Wattributes, "%qE attribute ignored", name);
6760       *no_add_attrs = true;
6761     }
6762
6763   return NULL_TREE;
6764 }
6765
6766 /* Handle an "alias" attribute; arguments as in
6767    struct attribute_spec.handler.  */
6768
6769 static tree
6770 handle_alias_attribute (tree *node, tree name, tree args,
6771                         int ARG_UNUSED (flags), bool *no_add_attrs)
6772 {
6773   tree decl = *node;
6774
6775   if (TREE_CODE (decl) != FUNCTION_DECL && TREE_CODE (decl) != VAR_DECL)
6776     {
6777       warning (OPT_Wattributes, "%qE attribute ignored", name);
6778       *no_add_attrs = true;
6779     }
6780   else if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
6781       || (TREE_CODE (decl) != FUNCTION_DECL
6782           && TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl))
6783       /* A static variable declaration is always a tentative definition,
6784          but the alias is a non-tentative definition which overrides.  */
6785       || (TREE_CODE (decl) != FUNCTION_DECL
6786           && ! TREE_PUBLIC (decl) && DECL_INITIAL (decl)))
6787     {
6788       error ("%q+D defined both normally and as an alias", decl);
6789       *no_add_attrs = true;
6790     }
6791
6792   /* Note that the very first time we process a nested declaration,
6793      decl_function_context will not be set.  Indeed, *would* never
6794      be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that
6795      we do below.  After such frobbery, pushdecl would set the context.
6796      In any case, this is never what we want.  */
6797   else if (decl_function_context (decl) == 0 && current_function_decl == NULL)
6798     {
6799       tree id;
6800
6801       id = TREE_VALUE (args);
6802       if (TREE_CODE (id) != STRING_CST)
6803         {
6804           error ("alias argument not a string");
6805           *no_add_attrs = true;
6806           return NULL_TREE;
6807         }
6808       id = get_identifier (TREE_STRING_POINTER (id));
6809       /* This counts as a use of the object pointed to.  */
6810       TREE_USED (id) = 1;
6811
6812       if (TREE_CODE (decl) == FUNCTION_DECL)
6813         DECL_INITIAL (decl) = error_mark_node;
6814       else
6815         {
6816           if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
6817             DECL_EXTERNAL (decl) = 1;
6818           else
6819             DECL_EXTERNAL (decl) = 0;
6820           TREE_STATIC (decl) = 1;
6821         }
6822     }
6823   else
6824     {
6825       warning (OPT_Wattributes, "%qE attribute ignored", name);
6826       *no_add_attrs = true;
6827     }
6828
6829   return NULL_TREE;
6830 }
6831
6832 /* Handle a "weakref" attribute; arguments as in struct
6833    attribute_spec.handler.  */
6834
6835 static tree
6836 handle_weakref_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6837                           int flags, bool *no_add_attrs)
6838 {
6839   tree attr = NULL_TREE;
6840
6841   /* We must ignore the attribute when it is associated with
6842      local-scoped decls, since attribute alias is ignored and many
6843      such symbols do not even have a DECL_WEAK field.  */
6844   if (decl_function_context (*node)
6845       || current_function_decl
6846       || (TREE_CODE (*node) != VAR_DECL && TREE_CODE (*node) != FUNCTION_DECL))
6847     {
6848       warning (OPT_Wattributes, "%qE attribute ignored", name);
6849       *no_add_attrs = true;
6850       return NULL_TREE;
6851     }
6852
6853   /* The idea here is that `weakref("name")' mutates into `weakref,
6854      alias("name")', and weakref without arguments, in turn,
6855      implicitly adds weak. */
6856
6857   if (args)
6858     {
6859       attr = tree_cons (get_identifier ("alias"), args, attr);
6860       attr = tree_cons (get_identifier ("weakref"), NULL_TREE, attr);
6861
6862       *no_add_attrs = true;
6863
6864       decl_attributes (node, attr, flags);
6865     }
6866   else
6867     {
6868       if (lookup_attribute ("alias", DECL_ATTRIBUTES (*node)))
6869         error_at (DECL_SOURCE_LOCATION (*node),
6870                   "weakref attribute must appear before alias attribute");
6871
6872       /* Can't call declare_weak because it wants this to be TREE_PUBLIC,
6873          and that isn't supported; and because it wants to add it to
6874          the list of weak decls, which isn't helpful.  */
6875       DECL_WEAK (*node) = 1;
6876     }
6877
6878   return NULL_TREE;
6879 }
6880
6881 /* Handle an "visibility" attribute; arguments as in
6882    struct attribute_spec.handler.  */
6883
6884 static tree
6885 handle_visibility_attribute (tree *node, tree name, tree args,
6886                              int ARG_UNUSED (flags),
6887                              bool *ARG_UNUSED (no_add_attrs))
6888 {
6889   tree decl = *node;
6890   tree id = TREE_VALUE (args);
6891   enum symbol_visibility vis;
6892
6893   if (TYPE_P (*node))
6894     {
6895       if (TREE_CODE (*node) == ENUMERAL_TYPE)
6896         /* OK */;
6897       else if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE)
6898         {
6899           warning (OPT_Wattributes, "%qE attribute ignored on non-class types",
6900                    name);
6901           return NULL_TREE;
6902         }
6903       else if (TYPE_FIELDS (*node))
6904         {
6905           error ("%qE attribute ignored because %qT is already defined",
6906                  name, *node);
6907           return NULL_TREE;
6908         }
6909     }
6910   else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl))
6911     {
6912       warning (OPT_Wattributes, "%qE attribute ignored", name);
6913       return NULL_TREE;
6914     }
6915
6916   if (TREE_CODE (id) != STRING_CST)
6917     {
6918       error ("visibility argument not a string");
6919       return NULL_TREE;
6920     }
6921
6922   /*  If this is a type, set the visibility on the type decl.  */
6923   if (TYPE_P (decl))
6924     {
6925       decl = TYPE_NAME (decl);
6926       if (!decl)
6927         return NULL_TREE;
6928       if (TREE_CODE (decl) == IDENTIFIER_NODE)
6929         {
6930            warning (OPT_Wattributes, "%qE attribute ignored on types",
6931                     name);
6932            return NULL_TREE;
6933         }
6934     }
6935
6936   if (strcmp (TREE_STRING_POINTER (id), "default") == 0)
6937     vis = VISIBILITY_DEFAULT;
6938   else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0)
6939     vis = VISIBILITY_INTERNAL;
6940   else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0)
6941     vis = VISIBILITY_HIDDEN;
6942   else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0)
6943     vis = VISIBILITY_PROTECTED;
6944   else
6945     {
6946       error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\"");
6947       vis = VISIBILITY_DEFAULT;
6948     }
6949
6950   if (DECL_VISIBILITY_SPECIFIED (decl)
6951       && vis != DECL_VISIBILITY (decl))
6952     {
6953       tree attributes = (TYPE_P (*node)
6954                          ? TYPE_ATTRIBUTES (*node)
6955                          : DECL_ATTRIBUTES (decl));
6956       if (lookup_attribute ("visibility", attributes))
6957         error ("%qD redeclared with different visibility", decl);
6958       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
6959                && lookup_attribute ("dllimport", attributes))
6960         error ("%qD was declared %qs which implies default visibility",
6961                decl, "dllimport");
6962       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
6963                && lookup_attribute ("dllexport", attributes))
6964         error ("%qD was declared %qs which implies default visibility",
6965                decl, "dllexport");
6966     }
6967
6968   DECL_VISIBILITY (decl) = vis;
6969   DECL_VISIBILITY_SPECIFIED (decl) = 1;
6970
6971   /* Go ahead and attach the attribute to the node as well.  This is needed
6972      so we can determine whether we have VISIBILITY_DEFAULT because the
6973      visibility was not specified, or because it was explicitly overridden
6974      from the containing scope.  */
6975
6976   return NULL_TREE;
6977 }
6978
6979 /* Determine the ELF symbol visibility for DECL, which is either a
6980    variable or a function.  It is an error to use this function if a
6981    definition of DECL is not available in this translation unit.
6982    Returns true if the final visibility has been determined by this
6983    function; false if the caller is free to make additional
6984    modifications.  */
6985
6986 bool
6987 c_determine_visibility (tree decl)
6988 {
6989   gcc_assert (TREE_CODE (decl) == VAR_DECL
6990               || TREE_CODE (decl) == FUNCTION_DECL);
6991
6992   /* If the user explicitly specified the visibility with an
6993      attribute, honor that.  DECL_VISIBILITY will have been set during
6994      the processing of the attribute.  We check for an explicit
6995      attribute, rather than just checking DECL_VISIBILITY_SPECIFIED,
6996      to distinguish the use of an attribute from the use of a "#pragma
6997      GCC visibility push(...)"; in the latter case we still want other
6998      considerations to be able to overrule the #pragma.  */
6999   if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl))
7000       || (TARGET_DLLIMPORT_DECL_ATTRIBUTES
7001           && (lookup_attribute ("dllimport", DECL_ATTRIBUTES (decl))
7002               || lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))))
7003     return true;
7004
7005   /* Set default visibility to whatever the user supplied with
7006      visibility_specified depending on #pragma GCC visibility.  */
7007   if (!DECL_VISIBILITY_SPECIFIED (decl))
7008     {
7009       if (visibility_options.inpragma
7010           || DECL_VISIBILITY (decl) != default_visibility)
7011         {
7012           DECL_VISIBILITY (decl) = default_visibility;
7013           DECL_VISIBILITY_SPECIFIED (decl) = visibility_options.inpragma;
7014           /* If visibility changed and DECL already has DECL_RTL, ensure
7015              symbol flags are updated.  */
7016           if (((TREE_CODE (decl) == VAR_DECL && TREE_STATIC (decl))
7017                || TREE_CODE (decl) == FUNCTION_DECL)
7018               && DECL_RTL_SET_P (decl))
7019             make_decl_rtl (decl);
7020         }
7021     }
7022   return false;
7023 }
7024
7025 /* Handle an "tls_model" attribute; arguments as in
7026    struct attribute_spec.handler.  */
7027
7028 static tree
7029 handle_tls_model_attribute (tree *node, tree name, tree args,
7030                             int ARG_UNUSED (flags), bool *no_add_attrs)
7031 {
7032   tree id;
7033   tree decl = *node;
7034   enum tls_model kind;
7035
7036   *no_add_attrs = true;
7037
7038   if (TREE_CODE (decl) != VAR_DECL || !DECL_THREAD_LOCAL_P (decl))
7039     {
7040       warning (OPT_Wattributes, "%qE attribute ignored", name);
7041       return NULL_TREE;
7042     }
7043
7044   kind = DECL_TLS_MODEL (decl);
7045   id = TREE_VALUE (args);
7046   if (TREE_CODE (id) != STRING_CST)
7047     {
7048       error ("tls_model argument not a string");
7049       return NULL_TREE;
7050     }
7051
7052   if (!strcmp (TREE_STRING_POINTER (id), "local-exec"))
7053     kind = TLS_MODEL_LOCAL_EXEC;
7054   else if (!strcmp (TREE_STRING_POINTER (id), "initial-exec"))
7055     kind = TLS_MODEL_INITIAL_EXEC;
7056   else if (!strcmp (TREE_STRING_POINTER (id), "local-dynamic"))
7057     kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
7058   else if (!strcmp (TREE_STRING_POINTER (id), "global-dynamic"))
7059     kind = TLS_MODEL_GLOBAL_DYNAMIC;
7060   else
7061     error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\"");
7062
7063   DECL_TLS_MODEL (decl) = kind;
7064   return NULL_TREE;
7065 }
7066
7067 /* Handle a "no_instrument_function" attribute; arguments as in
7068    struct attribute_spec.handler.  */
7069
7070 static tree
7071 handle_no_instrument_function_attribute (tree *node, tree name,
7072                                          tree ARG_UNUSED (args),
7073                                          int ARG_UNUSED (flags),
7074                                          bool *no_add_attrs)
7075 {
7076   tree decl = *node;
7077
7078   if (TREE_CODE (decl) != FUNCTION_DECL)
7079     {
7080       error_at (DECL_SOURCE_LOCATION (decl),
7081                 "%qE attribute applies only to functions", name);
7082       *no_add_attrs = true;
7083     }
7084   else if (DECL_INITIAL (decl))
7085     {
7086       error_at (DECL_SOURCE_LOCATION (decl),
7087                 "can%'t set %qE attribute after definition", name);
7088       *no_add_attrs = true;
7089     }
7090   else
7091     DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
7092
7093   return NULL_TREE;
7094 }
7095
7096 /* Handle a "malloc" attribute; arguments as in
7097    struct attribute_spec.handler.  */
7098
7099 static tree
7100 handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7101                          int ARG_UNUSED (flags), bool *no_add_attrs)
7102 {
7103   if (TREE_CODE (*node) == FUNCTION_DECL
7104       && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node))))
7105     DECL_IS_MALLOC (*node) = 1;
7106   else
7107     {
7108       warning (OPT_Wattributes, "%qE attribute ignored", name);
7109       *no_add_attrs = true;
7110     }
7111
7112   return NULL_TREE;
7113 }
7114
7115 /* Handle a "alloc_size" attribute; arguments as in
7116    struct attribute_spec.handler.  */
7117
7118 static tree
7119 handle_alloc_size_attribute (tree *node, tree ARG_UNUSED (name), tree args,
7120                              int ARG_UNUSED (flags), bool *no_add_attrs)
7121 {
7122   unsigned arg_count = type_num_arguments (*node);
7123   for (; args; args = TREE_CHAIN (args))
7124     {
7125       tree position = TREE_VALUE (args);
7126
7127       if (TREE_CODE (position) != INTEGER_CST
7128           || TREE_INT_CST_HIGH (position)
7129           || TREE_INT_CST_LOW (position) < 1
7130           || TREE_INT_CST_LOW (position) > arg_count )
7131         {
7132           warning (OPT_Wattributes,
7133                    "alloc_size parameter outside range");
7134           *no_add_attrs = true;
7135           return NULL_TREE;
7136         }
7137     }
7138   return NULL_TREE;
7139 }
7140
7141 /* Handle a "returns_twice" attribute; arguments as in
7142    struct attribute_spec.handler.  */
7143
7144 static tree
7145 handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7146                          int ARG_UNUSED (flags), bool *no_add_attrs)
7147 {
7148   if (TREE_CODE (*node) == FUNCTION_DECL)
7149     DECL_IS_RETURNS_TWICE (*node) = 1;
7150   else
7151     {
7152       warning (OPT_Wattributes, "%qE attribute ignored", name);
7153       *no_add_attrs = true;
7154     }
7155
7156   return NULL_TREE;
7157 }
7158
7159 /* Handle a "no_limit_stack" attribute; arguments as in
7160    struct attribute_spec.handler.  */
7161
7162 static tree
7163 handle_no_limit_stack_attribute (tree *node, tree name,
7164                                  tree ARG_UNUSED (args),
7165                                  int ARG_UNUSED (flags),
7166                                  bool *no_add_attrs)
7167 {
7168   tree decl = *node;
7169
7170   if (TREE_CODE (decl) != FUNCTION_DECL)
7171     {
7172       error_at (DECL_SOURCE_LOCATION (decl),
7173              "%qE attribute applies only to functions", name);
7174       *no_add_attrs = true;
7175     }
7176   else if (DECL_INITIAL (decl))
7177     {
7178       error_at (DECL_SOURCE_LOCATION (decl),
7179                 "can%'t set %qE attribute after definition", name);
7180       *no_add_attrs = true;
7181     }
7182   else
7183     DECL_NO_LIMIT_STACK (decl) = 1;
7184
7185   return NULL_TREE;
7186 }
7187
7188 /* Handle a "pure" attribute; arguments as in
7189    struct attribute_spec.handler.  */
7190
7191 static tree
7192 handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7193                        int ARG_UNUSED (flags), bool *no_add_attrs)
7194 {
7195   if (TREE_CODE (*node) == FUNCTION_DECL)
7196     DECL_PURE_P (*node) = 1;
7197   /* ??? TODO: Support types.  */
7198   else
7199     {
7200       warning (OPT_Wattributes, "%qE attribute ignored", name);
7201       *no_add_attrs = true;
7202     }
7203
7204   return NULL_TREE;
7205 }
7206
7207 /* Handle a "no vops" attribute; arguments as in
7208    struct attribute_spec.handler.  */
7209
7210 static tree
7211 handle_novops_attribute (tree *node, tree ARG_UNUSED (name),
7212                          tree ARG_UNUSED (args), int ARG_UNUSED (flags),
7213                          bool *ARG_UNUSED (no_add_attrs))
7214 {
7215   gcc_assert (TREE_CODE (*node) == FUNCTION_DECL);
7216   DECL_IS_NOVOPS (*node) = 1;
7217   return NULL_TREE;
7218 }
7219
7220 /* Handle a "deprecated" attribute; arguments as in
7221    struct attribute_spec.handler.  */
7222
7223 static tree
7224 handle_deprecated_attribute (tree *node, tree name,
7225                              tree args, int flags,
7226                              bool *no_add_attrs)
7227 {
7228   tree type = NULL_TREE;
7229   int warn = 0;
7230   tree what = NULL_TREE;
7231
7232   if (!args)
7233     *no_add_attrs = true;
7234   else if (TREE_CODE (TREE_VALUE (args)) != STRING_CST)
7235     {
7236       error ("deprecated message is not a string");
7237       *no_add_attrs = true;
7238     }
7239
7240   if (DECL_P (*node))
7241     {
7242       tree decl = *node;
7243       type = TREE_TYPE (decl);
7244
7245       if (TREE_CODE (decl) == TYPE_DECL
7246           || TREE_CODE (decl) == PARM_DECL
7247           || TREE_CODE (decl) == VAR_DECL
7248           || TREE_CODE (decl) == FUNCTION_DECL
7249           || TREE_CODE (decl) == FIELD_DECL)
7250         TREE_DEPRECATED (decl) = 1;
7251       else
7252         warn = 1;
7253     }
7254   else if (TYPE_P (*node))
7255     {
7256       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
7257         *node = build_variant_type_copy (*node);
7258       TREE_DEPRECATED (*node) = 1;
7259       type = *node;
7260     }
7261   else
7262     warn = 1;
7263
7264   if (warn)
7265     {
7266       *no_add_attrs = true;
7267       if (type && TYPE_NAME (type))
7268         {
7269           if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
7270             what = TYPE_NAME (*node);
7271           else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
7272                    && DECL_NAME (TYPE_NAME (type)))
7273             what = DECL_NAME (TYPE_NAME (type));
7274         }
7275       if (what)
7276         warning (OPT_Wattributes, "%qE attribute ignored for %qE", name, what);
7277       else
7278         warning (OPT_Wattributes, "%qE attribute ignored", name);
7279     }
7280
7281   return NULL_TREE;
7282 }
7283
7284 /* Handle a "vector_size" attribute; arguments as in
7285    struct attribute_spec.handler.  */
7286
7287 static tree
7288 handle_vector_size_attribute (tree *node, tree name, tree args,
7289                               int ARG_UNUSED (flags),
7290                               bool *no_add_attrs)
7291 {
7292   unsigned HOST_WIDE_INT vecsize, nunits;
7293   enum machine_mode orig_mode;
7294   tree type = *node, new_type, size;
7295
7296   *no_add_attrs = true;
7297
7298   size = TREE_VALUE (args);
7299
7300   if (!host_integerp (size, 1))
7301     {
7302       warning (OPT_Wattributes, "%qE attribute ignored", name);
7303       return NULL_TREE;
7304     }
7305
7306   /* Get the vector size (in bytes).  */
7307   vecsize = tree_low_cst (size, 1);
7308
7309   /* We need to provide for vector pointers, vector arrays, and
7310      functions returning vectors.  For example:
7311
7312        __attribute__((vector_size(16))) short *foo;
7313
7314      In this case, the mode is SI, but the type being modified is
7315      HI, so we need to look further.  */
7316
7317   while (POINTER_TYPE_P (type)
7318          || TREE_CODE (type) == FUNCTION_TYPE
7319          || TREE_CODE (type) == METHOD_TYPE
7320          || TREE_CODE (type) == ARRAY_TYPE
7321          || TREE_CODE (type) == OFFSET_TYPE)
7322     type = TREE_TYPE (type);
7323
7324   /* Get the mode of the type being modified.  */
7325   orig_mode = TYPE_MODE (type);
7326
7327   if ((!INTEGRAL_TYPE_P (type)
7328        && !SCALAR_FLOAT_TYPE_P (type)
7329        && !FIXED_POINT_TYPE_P (type))
7330       || (!SCALAR_FLOAT_MODE_P (orig_mode)
7331           && GET_MODE_CLASS (orig_mode) != MODE_INT
7332           && !ALL_SCALAR_FIXED_POINT_MODE_P (orig_mode))
7333       || !host_integerp (TYPE_SIZE_UNIT (type), 1)
7334       || TREE_CODE (type) == BOOLEAN_TYPE)
7335     {
7336       error ("invalid vector type for attribute %qE", name);
7337       return NULL_TREE;
7338     }
7339
7340   if (vecsize % tree_low_cst (TYPE_SIZE_UNIT (type), 1))
7341     {
7342       error ("vector size not an integral multiple of component size");
7343       return NULL;
7344     }
7345
7346   if (vecsize == 0)
7347     {
7348       error ("zero vector size");
7349       return NULL;
7350     }
7351
7352   /* Calculate how many units fit in the vector.  */
7353   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
7354   if (nunits & (nunits - 1))
7355     {
7356       error ("number of components of the vector not a power of two");
7357       return NULL_TREE;
7358     }
7359
7360   new_type = build_vector_type (type, nunits);
7361
7362   /* Build back pointers if needed.  */
7363   *node = lang_hooks.types.reconstruct_complex_type (*node, new_type);
7364
7365   return NULL_TREE;
7366 }
7367
7368 /* Handle the "nonnull" attribute.  */
7369 static tree
7370 handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
7371                           tree args, int ARG_UNUSED (flags),
7372                           bool *no_add_attrs)
7373 {
7374   tree type = *node;
7375   unsigned HOST_WIDE_INT attr_arg_num;
7376
7377   /* If no arguments are specified, all pointer arguments should be
7378      non-null.  Verify a full prototype is given so that the arguments
7379      will have the correct types when we actually check them later.  */
7380   if (!args)
7381     {
7382       if (!TYPE_ARG_TYPES (type))
7383         {
7384           error ("nonnull attribute without arguments on a non-prototype");
7385           *no_add_attrs = true;
7386         }
7387       return NULL_TREE;
7388     }
7389
7390   /* Argument list specified.  Verify that each argument number references
7391      a pointer argument.  */
7392   for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
7393     {
7394       tree argument;
7395       unsigned HOST_WIDE_INT arg_num = 0, ck_num;
7396
7397       if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
7398         {
7399           error ("nonnull argument has invalid operand number (argument %lu)",
7400                  (unsigned long) attr_arg_num);
7401           *no_add_attrs = true;
7402           return NULL_TREE;
7403         }
7404
7405       argument = TYPE_ARG_TYPES (type);
7406       if (argument)
7407         {
7408           for (ck_num = 1; ; ck_num++)
7409             {
7410               if (!argument || ck_num == arg_num)
7411                 break;
7412               argument = TREE_CHAIN (argument);
7413             }
7414
7415           if (!argument
7416               || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
7417             {
7418               error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)",
7419                      (unsigned long) attr_arg_num, (unsigned long) arg_num);
7420               *no_add_attrs = true;
7421               return NULL_TREE;
7422             }
7423
7424           if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
7425             {
7426               error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)",
7427                    (unsigned long) attr_arg_num, (unsigned long) arg_num);
7428               *no_add_attrs = true;
7429               return NULL_TREE;
7430             }
7431         }
7432     }
7433
7434   return NULL_TREE;
7435 }
7436
7437 /* Check the argument list of a function call for null in argument slots
7438    that are marked as requiring a non-null pointer argument.  The NARGS
7439    arguments are passed in the array ARGARRAY.
7440 */
7441
7442 static void
7443 check_function_nonnull (tree attrs, int nargs, tree *argarray)
7444 {
7445   tree a, args;
7446   int i;
7447
7448   for (a = attrs; a; a = TREE_CHAIN (a))
7449     {
7450       if (is_attribute_p ("nonnull", TREE_PURPOSE (a)))
7451         {
7452           args = TREE_VALUE (a);
7453
7454           /* Walk the argument list.  If we encounter an argument number we
7455              should check for non-null, do it.  If the attribute has no args,
7456              then every pointer argument is checked (in which case the check
7457              for pointer type is done in check_nonnull_arg).  */
7458           for (i = 0; i < nargs; i++)
7459             {
7460               if (!args || nonnull_check_p (args, i + 1))
7461                 check_function_arguments_recurse (check_nonnull_arg, NULL,
7462                                                   argarray[i],
7463                                                   i + 1);
7464             }
7465         }
7466     }
7467 }
7468
7469 /* Check that the Nth argument of a function call (counting backwards
7470    from the end) is a (pointer)0.  The NARGS arguments are passed in the
7471    array ARGARRAY.  */
7472
7473 static void
7474 check_function_sentinel (tree attrs, int nargs, tree *argarray, tree typelist)
7475 {
7476   tree attr = lookup_attribute ("sentinel", attrs);
7477
7478   if (attr)
7479     {
7480       int len = 0;
7481       int pos = 0;
7482       tree sentinel;
7483
7484       /* Skip over the named arguments.  */
7485       while (typelist && len < nargs)
7486         {
7487           typelist = TREE_CHAIN (typelist);
7488           len++;
7489         }
7490
7491       if (TREE_VALUE (attr))
7492         {
7493           tree p = TREE_VALUE (TREE_VALUE (attr));
7494           pos = TREE_INT_CST_LOW (p);
7495         }
7496
7497       /* The sentinel must be one of the varargs, i.e.
7498          in position >= the number of fixed arguments.  */
7499       if ((nargs - 1 - pos) < len)
7500         {
7501           warning (OPT_Wformat,
7502                    "not enough variable arguments to fit a sentinel");
7503           return;
7504         }
7505
7506       /* Validate the sentinel.  */
7507       sentinel = argarray[nargs - 1 - pos];
7508       if ((!POINTER_TYPE_P (TREE_TYPE (sentinel))
7509            || !integer_zerop (sentinel))
7510           /* Although __null (in C++) is only an integer we allow it
7511              nevertheless, as we are guaranteed that it's exactly
7512              as wide as a pointer, and we don't want to force
7513              users to cast the NULL they have written there.
7514              We warn with -Wstrict-null-sentinel, though.  */
7515           && (warn_strict_null_sentinel || null_node != sentinel))
7516         warning (OPT_Wformat, "missing sentinel in function call");
7517     }
7518 }
7519
7520 /* Helper for check_function_nonnull; given a list of operands which
7521    must be non-null in ARGS, determine if operand PARAM_NUM should be
7522    checked.  */
7523
7524 static bool
7525 nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num)
7526 {
7527   unsigned HOST_WIDE_INT arg_num = 0;
7528
7529   for (; args; args = TREE_CHAIN (args))
7530     {
7531       bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num);
7532
7533       gcc_assert (found);
7534
7535       if (arg_num == param_num)
7536         return true;
7537     }
7538   return false;
7539 }
7540
7541 /* Check that the function argument PARAM (which is operand number
7542    PARAM_NUM) is non-null.  This is called by check_function_nonnull
7543    via check_function_arguments_recurse.  */
7544
7545 static void
7546 check_nonnull_arg (void * ARG_UNUSED (ctx), tree param,
7547                    unsigned HOST_WIDE_INT param_num)
7548 {
7549   /* Just skip checking the argument if it's not a pointer.  This can
7550      happen if the "nonnull" attribute was given without an operand
7551      list (which means to check every pointer argument).  */
7552
7553   if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE)
7554     return;
7555
7556   if (integer_zerop (param))
7557     warning (OPT_Wnonnull, "null argument where non-null required "
7558              "(argument %lu)", (unsigned long) param_num);
7559 }
7560
7561 /* Helper for nonnull attribute handling; fetch the operand number
7562    from the attribute argument list.  */
7563
7564 static bool
7565 get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp)
7566 {
7567   /* Verify the arg number is a constant.  */
7568   if (TREE_CODE (arg_num_expr) != INTEGER_CST
7569       || TREE_INT_CST_HIGH (arg_num_expr) != 0)
7570     return false;
7571
7572   *valp = TREE_INT_CST_LOW (arg_num_expr);
7573   return true;
7574 }
7575
7576 /* Handle a "nothrow" attribute; arguments as in
7577    struct attribute_spec.handler.  */
7578
7579 static tree
7580 handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7581                           int ARG_UNUSED (flags), bool *no_add_attrs)
7582 {
7583   if (TREE_CODE (*node) == FUNCTION_DECL)
7584     TREE_NOTHROW (*node) = 1;
7585   /* ??? TODO: Support types.  */
7586   else
7587     {
7588       warning (OPT_Wattributes, "%qE attribute ignored", name);
7589       *no_add_attrs = true;
7590     }
7591
7592   return NULL_TREE;
7593 }
7594
7595 /* Handle a "cleanup" attribute; arguments as in
7596    struct attribute_spec.handler.  */
7597
7598 static tree
7599 handle_cleanup_attribute (tree *node, tree name, tree args,
7600                           int ARG_UNUSED (flags), bool *no_add_attrs)
7601 {
7602   tree decl = *node;
7603   tree cleanup_id, cleanup_decl;
7604
7605   /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do
7606      for global destructors in C++.  This requires infrastructure that
7607      we don't have generically at the moment.  It's also not a feature
7608      we'd be missing too much, since we do have attribute constructor.  */
7609   if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl))
7610     {
7611       warning (OPT_Wattributes, "%qE attribute ignored", name);
7612       *no_add_attrs = true;
7613       return NULL_TREE;
7614     }
7615
7616   /* Verify that the argument is a function in scope.  */
7617   /* ??? We could support pointers to functions here as well, if
7618      that was considered desirable.  */
7619   cleanup_id = TREE_VALUE (args);
7620   if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE)
7621     {
7622       error ("cleanup argument not an identifier");
7623       *no_add_attrs = true;
7624       return NULL_TREE;
7625     }
7626   cleanup_decl = lookup_name (cleanup_id);
7627   if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL)
7628     {
7629       error ("cleanup argument not a function");
7630       *no_add_attrs = true;
7631       return NULL_TREE;
7632     }
7633
7634   /* That the function has proper type is checked with the
7635      eventual call to build_function_call.  */
7636
7637   return NULL_TREE;
7638 }
7639
7640 /* Handle a "warn_unused_result" attribute.  No special handling.  */
7641
7642 static tree
7643 handle_warn_unused_result_attribute (tree *node, tree name,
7644                                tree ARG_UNUSED (args),
7645                                int ARG_UNUSED (flags), bool *no_add_attrs)
7646 {
7647   /* Ignore the attribute for functions not returning any value.  */
7648   if (VOID_TYPE_P (TREE_TYPE (*node)))
7649     {
7650       warning (OPT_Wattributes, "%qE attribute ignored", name);
7651       *no_add_attrs = true;
7652     }
7653
7654   return NULL_TREE;
7655 }
7656
7657 /* Handle a "sentinel" attribute.  */
7658
7659 static tree
7660 handle_sentinel_attribute (tree *node, tree name, tree args,
7661                            int ARG_UNUSED (flags), bool *no_add_attrs)
7662 {
7663   tree params = TYPE_ARG_TYPES (*node);
7664
7665   if (!params)
7666     {
7667       warning (OPT_Wattributes,
7668                "%qE attribute requires prototypes with named arguments", name);
7669       *no_add_attrs = true;
7670     }
7671   else
7672     {
7673       while (TREE_CHAIN (params))
7674         params = TREE_CHAIN (params);
7675
7676       if (VOID_TYPE_P (TREE_VALUE (params)))
7677         {
7678           warning (OPT_Wattributes,
7679                    "%qE attribute only applies to variadic functions", name);
7680           *no_add_attrs = true;
7681         }
7682     }
7683
7684   if (args)
7685     {
7686       tree position = TREE_VALUE (args);
7687
7688       if (TREE_CODE (position) != INTEGER_CST)
7689         {
7690           warning (OPT_Wattributes,
7691                    "requested position is not an integer constant");
7692           *no_add_attrs = true;
7693         }
7694       else
7695         {
7696           if (tree_int_cst_lt (position, integer_zero_node))
7697             {
7698               warning (OPT_Wattributes,
7699                        "requested position is less than zero");
7700               *no_add_attrs = true;
7701             }
7702         }
7703     }
7704
7705   return NULL_TREE;
7706 }
7707
7708 /* Handle a "type_generic" attribute.  */
7709
7710 static tree
7711 handle_type_generic_attribute (tree *node, tree ARG_UNUSED (name),
7712                                tree ARG_UNUSED (args), int ARG_UNUSED (flags),
7713                                bool * ARG_UNUSED (no_add_attrs))
7714 {
7715   tree params;
7716
7717   /* Ensure we have a function type.  */
7718   gcc_assert (TREE_CODE (*node) == FUNCTION_TYPE);
7719
7720   params = TYPE_ARG_TYPES (*node);
7721   while (params && ! VOID_TYPE_P (TREE_VALUE (params)))
7722     params = TREE_CHAIN (params);
7723
7724   /* Ensure we have a variadic function.  */
7725   gcc_assert (!params);
7726
7727   return NULL_TREE;
7728 }
7729
7730 /* Handle a "target" attribute.  */
7731
7732 static tree
7733 handle_target_attribute (tree *node, tree name, tree args, int flags,
7734                          bool *no_add_attrs)
7735 {
7736   /* Ensure we have a function type.  */
7737   if (TREE_CODE (*node) != FUNCTION_DECL)
7738     {
7739       warning (OPT_Wattributes, "%qE attribute ignored", name);
7740       *no_add_attrs = true;
7741     }
7742   else if (! targetm.target_option.valid_attribute_p (*node, name, args,
7743                                                       flags))
7744     *no_add_attrs = true;
7745
7746   return NULL_TREE;
7747 }
7748
7749 /* Arguments being collected for optimization.  */
7750 typedef const char *const_char_p;               /* For DEF_VEC_P.  */
7751 DEF_VEC_P(const_char_p);
7752 DEF_VEC_ALLOC_P(const_char_p, gc);
7753 static GTY(()) VEC(const_char_p, gc) *optimize_args;
7754
7755
7756 /* Inner function to convert a TREE_LIST to argv string to parse the optimize
7757    options in ARGS.  ATTR_P is true if this is for attribute(optimize), and
7758    false for #pragma GCC optimize.  */
7759
7760 bool
7761 parse_optimize_options (tree args, bool attr_p)
7762 {
7763   bool ret = true;
7764   unsigned opt_argc;
7765   unsigned i;
7766   int saved_flag_strict_aliasing;
7767   const char **opt_argv;
7768   tree ap;
7769
7770   /* Build up argv vector.  Just in case the string is stored away, use garbage
7771      collected strings.  */
7772   VEC_truncate (const_char_p, optimize_args, 0);
7773   VEC_safe_push (const_char_p, gc, optimize_args, NULL);
7774
7775   for (ap = args; ap != NULL_TREE; ap = TREE_CHAIN (ap))
7776     {
7777       tree value = TREE_VALUE (ap);
7778
7779       if (TREE_CODE (value) == INTEGER_CST)
7780         {
7781           char buffer[20];
7782           sprintf (buffer, "-O%ld", (long) TREE_INT_CST_LOW (value));
7783           VEC_safe_push (const_char_p, gc, optimize_args, ggc_strdup (buffer));
7784         }
7785
7786       else if (TREE_CODE (value) == STRING_CST)
7787         {
7788           /* Split string into multiple substrings.  */
7789           size_t len = TREE_STRING_LENGTH (value);
7790           char *p = ASTRDUP (TREE_STRING_POINTER (value));
7791           char *end = p + len;
7792           char *comma;
7793           char *next_p = p;
7794
7795           while (next_p != NULL)
7796             {
7797               size_t len2;
7798               char *q, *r;
7799
7800               p = next_p;
7801               comma = strchr (p, ',');
7802               if (comma)
7803                 {
7804                   len2 = comma - p;
7805                   *comma = '\0';
7806                   next_p = comma+1;
7807                 }
7808               else
7809                 {
7810                   len2 = end - p;
7811                   next_p = NULL;
7812                 }
7813
7814               r = q = (char *) ggc_alloc (len2 + 3);
7815
7816               /* If the user supplied -Oxxx or -fxxx, only allow -Oxxx or -fxxx
7817                  options.  */
7818               if (*p == '-' && p[1] != 'O' && p[1] != 'f')
7819                 {
7820                   ret = false;
7821                   if (attr_p)
7822                     warning (OPT_Wattributes,
7823                              "Bad option %s to optimize attribute.", p);
7824                   else
7825                     warning (OPT_Wpragmas,
7826                              "Bad option %s to pragma attribute", p);
7827                   continue;
7828                 }
7829
7830               if (*p != '-')
7831                 {
7832                   *r++ = '-';
7833
7834                   /* Assume that Ox is -Ox, a numeric value is -Ox, a s by
7835                      itself is -Os, and any other switch begins with a -f.  */
7836                   if ((*p >= '0' && *p <= '9')
7837                       || (p[0] == 's' && p[1] == '\0'))
7838                     *r++ = 'O';
7839                   else if (*p != 'O')
7840                     *r++ = 'f';
7841                 }
7842
7843               memcpy (r, p, len2);
7844               r[len2] = '\0';
7845               VEC_safe_push (const_char_p, gc, optimize_args, q);
7846             }
7847
7848         }
7849     }
7850
7851   opt_argc = VEC_length (const_char_p, optimize_args);
7852   opt_argv = (const char **) alloca (sizeof (char *) * (opt_argc + 1));
7853
7854   for (i = 1; i < opt_argc; i++)
7855     opt_argv[i] = VEC_index (const_char_p, optimize_args, i);
7856
7857   saved_flag_strict_aliasing = flag_strict_aliasing;
7858
7859   /* Now parse the options.  */
7860   decode_options (opt_argc, opt_argv);
7861
7862   targetm.override_options_after_change();
7863
7864   /* Don't allow changing -fstrict-aliasing.  */
7865   flag_strict_aliasing = saved_flag_strict_aliasing;
7866
7867   VEC_truncate (const_char_p, optimize_args, 0);
7868   return ret;
7869 }
7870
7871 /* For handling "optimize" attribute. arguments as in
7872    struct attribute_spec.handler.  */
7873
7874 static tree
7875 handle_optimize_attribute (tree *node, tree name, tree args,
7876                            int ARG_UNUSED (flags), bool *no_add_attrs)
7877 {
7878   /* Ensure we have a function type.  */
7879   if (TREE_CODE (*node) != FUNCTION_DECL)
7880     {
7881       warning (OPT_Wattributes, "%qE attribute ignored", name);
7882       *no_add_attrs = true;
7883     }
7884   else
7885     {
7886       struct cl_optimization cur_opts;
7887       tree old_opts = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node);
7888
7889       /* Save current options.  */
7890       cl_optimization_save (&cur_opts);
7891
7892       /* If we previously had some optimization options, use them as the
7893          default.  */
7894       if (old_opts)
7895         cl_optimization_restore (TREE_OPTIMIZATION (old_opts));
7896
7897       /* Parse options, and update the vector.  */
7898       parse_optimize_options (args, true);
7899       DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node)
7900         = build_optimization_node ();
7901
7902       /* Restore current options.  */
7903       cl_optimization_restore (&cur_opts);
7904     }
7905
7906   return NULL_TREE;
7907 }
7908 \f
7909 /* Check for valid arguments being passed to a function.
7910    ATTRS is a list of attributes.  There are NARGS arguments in the array
7911    ARGARRAY.  TYPELIST is the list of argument types for the function.
7912  */
7913 void
7914 check_function_arguments (tree attrs, int nargs, tree *argarray, tree typelist)
7915 {
7916   /* Check for null being passed in a pointer argument that must be
7917      non-null.  We also need to do this if format checking is enabled.  */
7918
7919   if (warn_nonnull)
7920     check_function_nonnull (attrs, nargs, argarray);
7921
7922   /* Check for errors in format strings.  */
7923
7924   if (warn_format || warn_missing_format_attribute)
7925     check_function_format (attrs, nargs, argarray);
7926
7927   if (warn_format)
7928     check_function_sentinel (attrs, nargs, argarray, typelist);
7929 }
7930
7931 /* Generic argument checking recursion routine.  PARAM is the argument to
7932    be checked.  PARAM_NUM is the number of the argument.  CALLBACK is invoked
7933    once the argument is resolved.  CTX is context for the callback.  */
7934 void
7935 check_function_arguments_recurse (void (*callback)
7936                                   (void *, tree, unsigned HOST_WIDE_INT),
7937                                   void *ctx, tree param,
7938                                   unsigned HOST_WIDE_INT param_num)
7939 {
7940   if (CONVERT_EXPR_P (param)
7941       && (TYPE_PRECISION (TREE_TYPE (param))
7942           == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (param, 0)))))
7943     {
7944       /* Strip coercion.  */
7945       check_function_arguments_recurse (callback, ctx,
7946                                         TREE_OPERAND (param, 0), param_num);
7947       return;
7948     }
7949
7950   if (TREE_CODE (param) == CALL_EXPR)
7951     {
7952       tree type = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (param)));
7953       tree attrs;
7954       bool found_format_arg = false;
7955
7956       /* See if this is a call to a known internationalization function
7957          that modifies a format arg.  Such a function may have multiple
7958          format_arg attributes (for example, ngettext).  */
7959
7960       for (attrs = TYPE_ATTRIBUTES (type);
7961            attrs;
7962            attrs = TREE_CHAIN (attrs))
7963         if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs)))
7964           {
7965             tree inner_arg;
7966             tree format_num_expr;
7967             int format_num;
7968             int i;
7969             call_expr_arg_iterator iter;
7970
7971             /* Extract the argument number, which was previously checked
7972                to be valid.  */
7973             format_num_expr = TREE_VALUE (TREE_VALUE (attrs));
7974
7975             gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST
7976                         && !TREE_INT_CST_HIGH (format_num_expr));
7977
7978             format_num = TREE_INT_CST_LOW (format_num_expr);
7979
7980             for (inner_arg = first_call_expr_arg (param, &iter), i = 1;
7981                  inner_arg != 0;
7982                  inner_arg = next_call_expr_arg (&iter), i++)
7983               if (i == format_num)
7984                 {
7985                   check_function_arguments_recurse (callback, ctx,
7986                                                     inner_arg, param_num);
7987                   found_format_arg = true;
7988                   break;
7989                 }
7990           }
7991
7992       /* If we found a format_arg attribute and did a recursive check,
7993          we are done with checking this argument.  Otherwise, we continue
7994          and this will be considered a non-literal.  */
7995       if (found_format_arg)
7996         return;
7997     }
7998
7999   if (TREE_CODE (param) == COND_EXPR)
8000     {
8001       /* Check both halves of the conditional expression.  */
8002       check_function_arguments_recurse (callback, ctx,
8003                                         TREE_OPERAND (param, 1), param_num);
8004       check_function_arguments_recurse (callback, ctx,
8005                                         TREE_OPERAND (param, 2), param_num);
8006       return;
8007     }
8008
8009   (*callback) (ctx, param, param_num);
8010 }
8011
8012 /* Checks for a builtin function FNDECL that the number of arguments
8013    NARGS against the required number REQUIRED and issues an error if
8014    there is a mismatch.  Returns true if the number of arguments is
8015    correct, otherwise false.  */
8016
8017 static bool
8018 builtin_function_validate_nargs (tree fndecl, int nargs, int required)
8019 {
8020   if (nargs < required)
8021     {
8022       error_at (input_location,
8023                 "not enough arguments to function %qE", fndecl);
8024       return false;
8025     }
8026   else if (nargs > required)
8027     {
8028       error_at (input_location,
8029                 "too many arguments to function %qE", fndecl);
8030       return false;
8031     }
8032   return true;
8033 }
8034
8035 /* Verifies the NARGS arguments ARGS to the builtin function FNDECL.
8036    Returns false if there was an error, otherwise true.  */
8037
8038 bool
8039 check_builtin_function_arguments (tree fndecl, int nargs, tree *args)
8040 {
8041   if (!DECL_BUILT_IN (fndecl)
8042       || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL)
8043     return true;
8044
8045   switch (DECL_FUNCTION_CODE (fndecl))
8046     {
8047     case BUILT_IN_CONSTANT_P:
8048       return builtin_function_validate_nargs (fndecl, nargs, 1);
8049
8050     case BUILT_IN_ISFINITE:
8051     case BUILT_IN_ISINF:
8052     case BUILT_IN_ISINF_SIGN:
8053     case BUILT_IN_ISNAN:
8054     case BUILT_IN_ISNORMAL:
8055       if (builtin_function_validate_nargs (fndecl, nargs, 1))
8056         {
8057           if (TREE_CODE (TREE_TYPE (args[0])) != REAL_TYPE)
8058             {
8059               error ("non-floating-point argument in call to "
8060                      "function %qE", fndecl);
8061               return false;
8062             }
8063           return true;
8064         }
8065       return false;
8066
8067     case BUILT_IN_ISGREATER:
8068     case BUILT_IN_ISGREATEREQUAL:
8069     case BUILT_IN_ISLESS:
8070     case BUILT_IN_ISLESSEQUAL:
8071     case BUILT_IN_ISLESSGREATER:
8072     case BUILT_IN_ISUNORDERED:
8073       if (builtin_function_validate_nargs (fndecl, nargs, 2))
8074         {
8075           enum tree_code code0, code1;
8076           code0 = TREE_CODE (TREE_TYPE (args[0]));
8077           code1 = TREE_CODE (TREE_TYPE (args[1]));
8078           if (!((code0 == REAL_TYPE && code1 == REAL_TYPE)
8079                 || (code0 == REAL_TYPE && code1 == INTEGER_TYPE)
8080                 || (code0 == INTEGER_TYPE && code1 == REAL_TYPE)))
8081             {
8082               error ("non-floating-point arguments in call to "
8083                      "function %qE", fndecl);
8084               return false;
8085             }
8086           return true;
8087         }
8088       return false;
8089
8090     case BUILT_IN_FPCLASSIFY:
8091       if (builtin_function_validate_nargs (fndecl, nargs, 6))
8092         {
8093           unsigned i;
8094
8095           for (i=0; i<5; i++)
8096             if (TREE_CODE (args[i]) != INTEGER_CST)
8097               {
8098                 error ("non-const integer argument %u in call to function %qE",
8099                        i+1, fndecl);
8100                 return false;
8101               }
8102
8103           if (TREE_CODE (TREE_TYPE (args[5])) != REAL_TYPE)
8104             {
8105               error ("non-floating-point argument in call to function %qE",
8106                      fndecl);
8107               return false;
8108             }
8109           return true;
8110         }
8111       return false;
8112
8113     default:
8114       return true;
8115     }
8116 }
8117
8118 /* Function to help qsort sort FIELD_DECLs by name order.  */
8119
8120 int
8121 field_decl_cmp (const void *x_p, const void *y_p)
8122 {
8123   const tree *const x = (const tree *const) x_p;
8124   const tree *const y = (const tree *const) y_p;
8125
8126   if (DECL_NAME (*x) == DECL_NAME (*y))
8127     /* A nontype is "greater" than a type.  */
8128     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
8129   if (DECL_NAME (*x) == NULL_TREE)
8130     return -1;
8131   if (DECL_NAME (*y) == NULL_TREE)
8132     return 1;
8133   if (DECL_NAME (*x) < DECL_NAME (*y))
8134     return -1;
8135   return 1;
8136 }
8137
8138 static struct {
8139   gt_pointer_operator new_value;
8140   void *cookie;
8141 } resort_data;
8142
8143 /* This routine compares two fields like field_decl_cmp but using the
8144 pointer operator in resort_data.  */
8145
8146 static int
8147 resort_field_decl_cmp (const void *x_p, const void *y_p)
8148 {
8149   const tree *const x = (const tree *const) x_p;
8150   const tree *const y = (const tree *const) y_p;
8151
8152   if (DECL_NAME (*x) == DECL_NAME (*y))
8153     /* A nontype is "greater" than a type.  */
8154     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
8155   if (DECL_NAME (*x) == NULL_TREE)
8156     return -1;
8157   if (DECL_NAME (*y) == NULL_TREE)
8158     return 1;
8159   {
8160     tree d1 = DECL_NAME (*x);
8161     tree d2 = DECL_NAME (*y);
8162     resort_data.new_value (&d1, resort_data.cookie);
8163     resort_data.new_value (&d2, resort_data.cookie);
8164     if (d1 < d2)
8165       return -1;
8166   }
8167   return 1;
8168 }
8169
8170 /* Resort DECL_SORTED_FIELDS because pointers have been reordered.  */
8171
8172 void
8173 resort_sorted_fields (void *obj,
8174                       void * ARG_UNUSED (orig_obj),
8175                       gt_pointer_operator new_value,
8176                       void *cookie)
8177 {
8178   struct sorted_fields_type *sf = (struct sorted_fields_type *) obj;
8179   resort_data.new_value = new_value;
8180   resort_data.cookie = cookie;
8181   qsort (&sf->elts[0], sf->len, sizeof (tree),
8182          resort_field_decl_cmp);
8183 }
8184
8185 /* Subroutine of c_parse_error.
8186    Return the result of concatenating LHS and RHS. RHS is really
8187    a string literal, its first character is indicated by RHS_START and
8188    RHS_SIZE is its length (including the terminating NUL character).
8189
8190    The caller is responsible for deleting the returned pointer.  */
8191
8192 static char *
8193 catenate_strings (const char *lhs, const char *rhs_start, int rhs_size)
8194 {
8195   const int lhs_size = strlen (lhs);
8196   char *result = XNEWVEC (char, lhs_size + rhs_size);
8197   strncpy (result, lhs, lhs_size);
8198   strncpy (result + lhs_size, rhs_start, rhs_size);
8199   return result;
8200 }
8201
8202 /* Issue the error given by GMSGID, indicating that it occurred before
8203    TOKEN, which had the associated VALUE.  */
8204
8205 void
8206 c_parse_error (const char *gmsgid, enum cpp_ttype token_type,
8207                tree value, unsigned char token_flags)
8208 {
8209 #define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2))
8210
8211   char *message = NULL;
8212
8213   if (token_type == CPP_EOF)
8214     message = catenate_messages (gmsgid, " at end of input");
8215   else if (token_type == CPP_CHAR
8216            || token_type == CPP_WCHAR
8217            || token_type == CPP_CHAR16
8218            || token_type == CPP_CHAR32)
8219     {
8220       unsigned int val = TREE_INT_CST_LOW (value);
8221       const char *prefix;
8222
8223       switch (token_type)
8224         {
8225         default:
8226           prefix = "";
8227           break;
8228         case CPP_WCHAR:
8229           prefix = "L";
8230           break;
8231         case CPP_CHAR16:
8232           prefix = "u";
8233           break;
8234         case CPP_CHAR32:
8235           prefix = "U";
8236           break;
8237         }
8238
8239       if (val <= UCHAR_MAX && ISGRAPH (val))
8240         message = catenate_messages (gmsgid, " before %s'%c'");
8241       else
8242         message = catenate_messages (gmsgid, " before %s'\\x%x'");
8243
8244       error (message, prefix, val);
8245       free (message);
8246       message = NULL;
8247     }
8248   else if (token_type == CPP_STRING
8249            || token_type == CPP_WSTRING
8250            || token_type == CPP_STRING16
8251            || token_type == CPP_STRING32
8252            || token_type == CPP_UTF8STRING)
8253     message = catenate_messages (gmsgid, " before string constant");
8254   else if (token_type == CPP_NUMBER)
8255     message = catenate_messages (gmsgid, " before numeric constant");
8256   else if (token_type == CPP_NAME)
8257     {
8258       message = catenate_messages (gmsgid, " before %qE");
8259       error (message, value);
8260       free (message);
8261       message = NULL;
8262     }
8263   else if (token_type == CPP_PRAGMA)
8264     message = catenate_messages (gmsgid, " before %<#pragma%>");
8265   else if (token_type == CPP_PRAGMA_EOL)
8266     message = catenate_messages (gmsgid, " before end of line");
8267   else if (token_type < N_TTYPES)
8268     {
8269       message = catenate_messages (gmsgid, " before %qs token");
8270       error (message, cpp_type2name (token_type, token_flags));
8271       free (message);
8272       message = NULL;
8273     }
8274   else
8275     error (gmsgid);
8276
8277   if (message)
8278     {
8279       error (message);
8280       free (message);
8281     }
8282 #undef catenate_messages
8283 }
8284
8285 /* Callback from cpp_error for PFILE to print diagnostics from the
8286    preprocessor.  The diagnostic is of type LEVEL, at location
8287    LOCATION unless this is after lexing and the compiler's location
8288    should be used instead, with column number possibly overridden by
8289    COLUMN_OVERRIDE if not zero; MSG is the translated message and AP
8290    the arguments.  Returns true if a diagnostic was emitted, false
8291    otherwise.  */
8292
8293 bool
8294 c_cpp_error (cpp_reader *pfile ATTRIBUTE_UNUSED, int level,
8295              location_t location, unsigned int column_override,
8296              const char *msg, va_list *ap)
8297 {
8298   diagnostic_info diagnostic;
8299   diagnostic_t dlevel;
8300   int save_warn_system_headers = warn_system_headers;
8301   bool ret;
8302
8303   switch (level)
8304     {
8305     case CPP_DL_WARNING_SYSHDR:
8306       if (flag_no_output)
8307         return false;
8308       warn_system_headers = 1;
8309       /* Fall through.  */
8310     case CPP_DL_WARNING:
8311       if (flag_no_output)
8312         return false;
8313       dlevel = DK_WARNING;
8314       break;
8315     case CPP_DL_PEDWARN:
8316       if (flag_no_output && !flag_pedantic_errors)
8317         return false;
8318       dlevel = DK_PEDWARN;
8319       break;
8320     case CPP_DL_ERROR:
8321       dlevel = DK_ERROR;
8322       break;
8323     case CPP_DL_ICE:
8324       dlevel = DK_ICE;
8325       break;
8326     case CPP_DL_NOTE:
8327       dlevel = DK_NOTE;
8328       break;
8329     case CPP_DL_FATAL:
8330       dlevel = DK_FATAL;
8331       break;
8332     default:
8333       gcc_unreachable ();
8334     }
8335   if (done_lexing)
8336     location = input_location;
8337   diagnostic_set_info_translated (&diagnostic, msg, ap,
8338                                   location, dlevel);
8339   if (column_override)
8340     diagnostic_override_column (&diagnostic, column_override);
8341   ret = report_diagnostic (&diagnostic);
8342   if (level == CPP_DL_WARNING_SYSHDR)
8343     warn_system_headers = save_warn_system_headers;
8344   return ret;
8345 }
8346
8347 /* Convert a character from the host to the target execution character
8348    set.  cpplib handles this, mostly.  */
8349
8350 HOST_WIDE_INT
8351 c_common_to_target_charset (HOST_WIDE_INT c)
8352 {
8353   /* Character constants in GCC proper are sign-extended under -fsigned-char,
8354      zero-extended under -fno-signed-char.  cpplib insists that characters
8355      and character constants are always unsigned.  Hence we must convert
8356      back and forth.  */
8357   cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1);
8358
8359   uc = cpp_host_to_exec_charset (parse_in, uc);
8360
8361   if (flag_signed_char)
8362     return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE)
8363                                >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE);
8364   else
8365     return uc;
8366 }
8367
8368 /* Build the result of __builtin_offsetof.  EXPR is a nested sequence of
8369    component references, with STOP_REF, or alternatively an INDIRECT_REF of
8370    NULL, at the bottom; much like the traditional rendering of offsetof as a
8371    macro.  Returns the folded and properly cast result.  */
8372
8373 static tree
8374 fold_offsetof_1 (tree expr, tree stop_ref)
8375 {
8376   enum tree_code code = PLUS_EXPR;
8377   tree base, off, t;
8378
8379   if (expr == stop_ref && TREE_CODE (expr) != ERROR_MARK)
8380     return size_zero_node;
8381
8382   switch (TREE_CODE (expr))
8383     {
8384     case ERROR_MARK:
8385       return expr;
8386
8387     case VAR_DECL:
8388       error ("cannot apply %<offsetof%> to static data member %qD", expr);
8389       return error_mark_node;
8390
8391     case CALL_EXPR:
8392     case TARGET_EXPR:
8393       error ("cannot apply %<offsetof%> when %<operator[]%> is overloaded");
8394       return error_mark_node;
8395
8396     case NOP_EXPR:
8397     case INDIRECT_REF:
8398       if (!integer_zerop (TREE_OPERAND (expr, 0)))
8399         {
8400           error ("cannot apply %<offsetof%> to a non constant address");
8401           return error_mark_node;
8402         }
8403       return size_zero_node;
8404
8405     case COMPONENT_REF:
8406       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
8407       if (base == error_mark_node)
8408         return base;
8409
8410       t = TREE_OPERAND (expr, 1);
8411       if (DECL_C_BIT_FIELD (t))
8412         {
8413           error ("attempt to take address of bit-field structure "
8414                  "member %qD", t);
8415           return error_mark_node;
8416         }
8417       off = size_binop_loc (input_location, PLUS_EXPR, DECL_FIELD_OFFSET (t),
8418                             size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t),
8419                                                     1)
8420                                       / BITS_PER_UNIT));
8421       break;
8422
8423     case ARRAY_REF:
8424       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
8425       if (base == error_mark_node)
8426         return base;
8427
8428       t = TREE_OPERAND (expr, 1);
8429       if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0)
8430         {
8431           code = MINUS_EXPR;
8432           t = fold_build1_loc (input_location, NEGATE_EXPR, TREE_TYPE (t), t);
8433         }
8434       t = convert (sizetype, t);
8435       off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
8436
8437       /* Check if the offset goes beyond the upper bound of the array.  */
8438       if (code == PLUS_EXPR && TREE_CODE (t) == INTEGER_CST)
8439         {
8440           tree upbound = array_ref_up_bound (expr);
8441           if (upbound != NULL_TREE
8442               && TREE_CODE (upbound) == INTEGER_CST
8443               && !tree_int_cst_equal (upbound,
8444                                       TYPE_MAX_VALUE (TREE_TYPE (upbound))))
8445             {
8446               upbound = size_binop (PLUS_EXPR, upbound,
8447                                     build_int_cst (TREE_TYPE (upbound), 1));
8448               if (tree_int_cst_lt (upbound, t))
8449                 {
8450                   tree v;
8451
8452                   for (v = TREE_OPERAND (expr, 0);
8453                        TREE_CODE (v) == COMPONENT_REF;
8454                        v = TREE_OPERAND (v, 0))
8455                     if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
8456                         == RECORD_TYPE)
8457                       {
8458                         tree fld_chain = TREE_CHAIN (TREE_OPERAND (v, 1));
8459                         for (; fld_chain; fld_chain = TREE_CHAIN (fld_chain))
8460                           if (TREE_CODE (fld_chain) == FIELD_DECL)
8461                             break;
8462
8463                         if (fld_chain)
8464                           break;
8465                       }
8466                   /* Don't warn if the array might be considered a poor
8467                      man's flexible array member with a very permissive
8468                      definition thereof.  */
8469                   if (TREE_CODE (v) == ARRAY_REF
8470                       || TREE_CODE (v) == COMPONENT_REF)
8471                     warning (OPT_Warray_bounds,
8472                              "index %E denotes an offset "
8473                              "greater than size of %qT",
8474                              t, TREE_TYPE (TREE_OPERAND (expr, 0)));
8475                 }
8476             }
8477         }
8478       break;
8479
8480     case COMPOUND_EXPR:
8481       /* Handle static members of volatile structs.  */
8482       t = TREE_OPERAND (expr, 1);
8483       gcc_assert (TREE_CODE (t) == VAR_DECL);
8484       return fold_offsetof_1 (t, stop_ref);
8485
8486     default:
8487       gcc_unreachable ();
8488     }
8489
8490   return size_binop (code, base, off);
8491 }
8492
8493 tree
8494 fold_offsetof (tree expr, tree stop_ref)
8495 {
8496   /* Convert back from the internal sizetype to size_t.  */
8497   return convert (size_type_node, fold_offsetof_1 (expr, stop_ref));
8498 }
8499
8500 /* Print an error message for an invalid lvalue.  USE says
8501    how the lvalue is being used and so selects the error message.  */
8502
8503 void
8504 lvalue_error (enum lvalue_use use)
8505 {
8506   switch (use)
8507     {
8508     case lv_assign:
8509       error ("lvalue required as left operand of assignment");
8510       break;
8511     case lv_increment:
8512       error ("lvalue required as increment operand");
8513       break;
8514     case lv_decrement:
8515       error ("lvalue required as decrement operand");
8516       break;
8517     case lv_addressof:
8518       error ("lvalue required as unary %<&%> operand");
8519       break;
8520     case lv_asm:
8521       error ("lvalue required in asm statement");
8522       break;
8523     default:
8524       gcc_unreachable ();
8525     }
8526 }
8527 \f
8528 /* *PTYPE is an incomplete array.  Complete it with a domain based on
8529    INITIAL_VALUE.  If INITIAL_VALUE is not present, use 1 if DO_DEFAULT
8530    is true.  Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered,
8531    2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty.  */
8532
8533 int
8534 complete_array_type (tree *ptype, tree initial_value, bool do_default)
8535 {
8536   tree maxindex, type, main_type, elt, unqual_elt;
8537   int failure = 0, quals;
8538   hashval_t hashcode = 0;
8539
8540   maxindex = size_zero_node;
8541   if (initial_value)
8542     {
8543       if (TREE_CODE (initial_value) == STRING_CST)
8544         {
8545           int eltsize
8546             = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value)));
8547           maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1);
8548         }
8549       else if (TREE_CODE (initial_value) == CONSTRUCTOR)
8550         {
8551           VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (initial_value);
8552
8553           if (VEC_empty (constructor_elt, v))
8554             {
8555               if (pedantic)
8556                 failure = 3;
8557               maxindex = integer_minus_one_node;
8558             }
8559           else
8560             {
8561               tree curindex;
8562               unsigned HOST_WIDE_INT cnt;
8563               constructor_elt *ce;
8564               bool fold_p = false;
8565
8566               if (VEC_index (constructor_elt, v, 0)->index)
8567                 maxindex = fold_convert_loc (input_location, sizetype,
8568                                              VEC_index (constructor_elt,
8569                                                         v, 0)->index);
8570               curindex = maxindex;
8571
8572               for (cnt = 1;
8573                    VEC_iterate (constructor_elt, v, cnt, ce);
8574                    cnt++)
8575                 {
8576                   bool curfold_p = false;
8577                   if (ce->index)
8578                     curindex = ce->index, curfold_p = true;
8579                   else
8580                     {
8581                       if (fold_p)
8582                         curindex = fold_convert (sizetype, curindex);
8583                       curindex = size_binop (PLUS_EXPR, curindex,
8584                                              size_one_node);
8585                     }
8586                   if (tree_int_cst_lt (maxindex, curindex))
8587                     maxindex = curindex, fold_p = curfold_p;
8588                 }
8589                if (fold_p)
8590                  maxindex = fold_convert (sizetype, maxindex);
8591             }
8592         }
8593       else
8594         {
8595           /* Make an error message unless that happened already.  */
8596           if (initial_value != error_mark_node)
8597             failure = 1;
8598         }
8599     }
8600   else
8601     {
8602       failure = 2;
8603       if (!do_default)
8604         return failure;
8605     }
8606
8607   type = *ptype;
8608   elt = TREE_TYPE (type);
8609   quals = TYPE_QUALS (strip_array_types (elt));
8610   if (quals == 0)
8611     unqual_elt = elt;
8612   else
8613     unqual_elt = c_build_qualified_type (elt, KEEP_QUAL_ADDR_SPACE (quals));
8614
8615   /* Using build_distinct_type_copy and modifying things afterward instead
8616      of using build_array_type to create a new type preserves all of the
8617      TYPE_LANG_FLAG_? bits that the front end may have set.  */
8618   main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
8619   TREE_TYPE (main_type) = unqual_elt;
8620   TYPE_DOMAIN (main_type) = build_index_type (maxindex);
8621   layout_type (main_type);
8622
8623   /* Make sure we have the canonical MAIN_TYPE. */
8624   hashcode = iterative_hash_object (TYPE_HASH (unqual_elt), hashcode);
8625   hashcode = iterative_hash_object (TYPE_HASH (TYPE_DOMAIN (main_type)),
8626                                     hashcode);
8627   main_type = type_hash_canon (hashcode, main_type);
8628
8629   /* Fix the canonical type.  */
8630   if (TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (main_type))
8631       || TYPE_STRUCTURAL_EQUALITY_P (TYPE_DOMAIN (main_type)))
8632     SET_TYPE_STRUCTURAL_EQUALITY (main_type);
8633   else if (TYPE_CANONICAL (TREE_TYPE (main_type)) != TREE_TYPE (main_type)
8634            || (TYPE_CANONICAL (TYPE_DOMAIN (main_type))
8635                != TYPE_DOMAIN (main_type)))
8636     TYPE_CANONICAL (main_type)
8637       = build_array_type (TYPE_CANONICAL (TREE_TYPE (main_type)),
8638                           TYPE_CANONICAL (TYPE_DOMAIN (main_type)));
8639   else
8640     TYPE_CANONICAL (main_type) = main_type;
8641
8642   if (quals == 0)
8643     type = main_type;
8644   else
8645     type = c_build_qualified_type (main_type, quals);
8646
8647   if (COMPLETE_TYPE_P (type)
8648       && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST
8649       && TREE_OVERFLOW (TYPE_SIZE_UNIT (type)))
8650     {
8651       error ("size of array is too large");
8652       /* If we proceed with the array type as it is, we'll eventually
8653          crash in tree_low_cst().  */
8654       type = error_mark_node;
8655     }
8656
8657   *ptype = type;
8658   return failure;
8659 }
8660
8661 \f
8662 /* Used to help initialize the builtin-types.def table.  When a type of
8663    the correct size doesn't exist, use error_mark_node instead of NULL.
8664    The later results in segfaults even when a decl using the type doesn't
8665    get invoked.  */
8666
8667 tree
8668 builtin_type_for_size (int size, bool unsignedp)
8669 {
8670   tree type = lang_hooks.types.type_for_size (size, unsignedp);
8671   return type ? type : error_mark_node;
8672 }
8673
8674 /* A helper function for resolve_overloaded_builtin in resolving the
8675    overloaded __sync_ builtins.  Returns a positive power of 2 if the
8676    first operand of PARAMS is a pointer to a supported data type.
8677    Returns 0 if an error is encountered.  */
8678
8679 static int
8680 sync_resolve_size (tree function, VEC(tree,gc) *params)
8681 {
8682   tree type;
8683   int size;
8684
8685   if (VEC_empty (tree, params))
8686     {
8687       error ("too few arguments to function %qE", function);
8688       return 0;
8689     }
8690
8691   type = TREE_TYPE (VEC_index (tree, params, 0));
8692   if (TREE_CODE (type) != POINTER_TYPE)
8693     goto incompatible;
8694
8695   type = TREE_TYPE (type);
8696   if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
8697     goto incompatible;
8698
8699   size = tree_low_cst (TYPE_SIZE_UNIT (type), 1);
8700   if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16)
8701     return size;
8702
8703  incompatible:
8704   error ("incompatible type for argument %d of %qE", 1, function);
8705   return 0;
8706 }
8707
8708 /* A helper function for resolve_overloaded_builtin.  Adds casts to
8709    PARAMS to make arguments match up with those of FUNCTION.  Drops
8710    the variadic arguments at the end.  Returns false if some error
8711    was encountered; true on success.  */
8712
8713 static bool
8714 sync_resolve_params (tree orig_function, tree function, VEC(tree, gc) *params)
8715 {
8716   tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (function));
8717   tree ptype;
8718   int number;
8719   unsigned int parmnum;
8720
8721   /* We've declared the implementation functions to use "volatile void *"
8722      as the pointer parameter, so we shouldn't get any complaints from the
8723      call to check_function_arguments what ever type the user used.  */
8724   arg_types = TREE_CHAIN (arg_types);
8725   ptype = TREE_TYPE (TREE_TYPE (VEC_index (tree, params, 0)));
8726   number = 2;
8727
8728   /* For the rest of the values, we need to cast these to FTYPE, so that we
8729      don't get warnings for passing pointer types, etc.  */
8730   parmnum = 0;
8731   while (arg_types != void_list_node)
8732     {
8733       tree val;
8734
8735       ++parmnum;
8736       if (VEC_length (tree, params) <= parmnum)
8737         {
8738           error ("too few arguments to function %qE", orig_function);
8739           return false;
8740         }
8741
8742       /* ??? Ideally for the first conversion we'd use convert_for_assignment
8743          so that we get warnings for anything that doesn't match the pointer
8744          type.  This isn't portable across the C and C++ front ends atm.  */
8745       val = VEC_index (tree, params, parmnum);
8746       val = convert (ptype, val);
8747       val = convert (TREE_VALUE (arg_types), val);
8748       VEC_replace (tree, params, parmnum, val);
8749
8750       arg_types = TREE_CHAIN (arg_types);
8751       number++;
8752     }
8753
8754   /* The definition of these primitives is variadic, with the remaining
8755      being "an optional list of variables protected by the memory barrier".
8756      No clue what that's supposed to mean, precisely, but we consider all
8757      call-clobbered variables to be protected so we're safe.  */
8758   VEC_truncate (tree, params, parmnum + 1);
8759
8760   return true;
8761 }
8762
8763 /* A helper function for resolve_overloaded_builtin.  Adds a cast to
8764    RESULT to make it match the type of the first pointer argument in
8765    PARAMS.  */
8766
8767 static tree
8768 sync_resolve_return (tree first_param, tree result)
8769 {
8770   tree ptype = TREE_TYPE (TREE_TYPE (first_param));
8771   ptype = TYPE_MAIN_VARIANT (ptype);
8772   return convert (ptype, result);
8773 }
8774
8775 /* Some builtin functions are placeholders for other expressions.  This
8776    function should be called immediately after parsing the call expression
8777    before surrounding code has committed to the type of the expression.
8778
8779    LOC is the location of the builtin call.
8780
8781    FUNCTION is the DECL that has been invoked; it is known to be a builtin.
8782    PARAMS is the argument list for the call.  The return value is non-null
8783    when expansion is complete, and null if normal processing should
8784    continue.  */
8785
8786 tree
8787 resolve_overloaded_builtin (location_t loc, tree function, VEC(tree,gc) *params)
8788 {
8789   enum built_in_function orig_code = DECL_FUNCTION_CODE (function);
8790   switch (DECL_BUILT_IN_CLASS (function))
8791     {
8792     case BUILT_IN_NORMAL:
8793       break;
8794     case BUILT_IN_MD:
8795       if (targetm.resolve_overloaded_builtin)
8796         return targetm.resolve_overloaded_builtin (loc, function, params);
8797       else
8798         return NULL_TREE;
8799     default:
8800       return NULL_TREE;
8801     }
8802
8803   /* Handle BUILT_IN_NORMAL here.  */
8804   switch (orig_code)
8805     {
8806     case BUILT_IN_FETCH_AND_ADD_N:
8807     case BUILT_IN_FETCH_AND_SUB_N:
8808     case BUILT_IN_FETCH_AND_OR_N:
8809     case BUILT_IN_FETCH_AND_AND_N:
8810     case BUILT_IN_FETCH_AND_XOR_N:
8811     case BUILT_IN_FETCH_AND_NAND_N:
8812     case BUILT_IN_ADD_AND_FETCH_N:
8813     case BUILT_IN_SUB_AND_FETCH_N:
8814     case BUILT_IN_OR_AND_FETCH_N:
8815     case BUILT_IN_AND_AND_FETCH_N:
8816     case BUILT_IN_XOR_AND_FETCH_N:
8817     case BUILT_IN_NAND_AND_FETCH_N:
8818     case BUILT_IN_BOOL_COMPARE_AND_SWAP_N:
8819     case BUILT_IN_VAL_COMPARE_AND_SWAP_N:
8820     case BUILT_IN_LOCK_TEST_AND_SET_N:
8821     case BUILT_IN_LOCK_RELEASE_N:
8822       {
8823         int n = sync_resolve_size (function, params);
8824         tree new_function, first_param, result;
8825
8826         if (n == 0)
8827           return error_mark_node;
8828
8829         new_function = built_in_decls[orig_code + exact_log2 (n) + 1];
8830         if (!sync_resolve_params (function, new_function, params))
8831           return error_mark_node;
8832
8833         first_param = VEC_index (tree, params, 0);
8834         result = build_function_call_vec (loc, new_function, params, NULL);
8835         if (orig_code != BUILT_IN_BOOL_COMPARE_AND_SWAP_N
8836             && orig_code != BUILT_IN_LOCK_RELEASE_N)
8837           result = sync_resolve_return (first_param, result);
8838
8839         return result;
8840       }
8841
8842     default:
8843       return NULL_TREE;
8844     }
8845 }
8846
8847 /* Ignoring their sign, return true if two scalar types are the same.  */
8848 bool
8849 same_scalar_type_ignoring_signedness (tree t1, tree t2)
8850 {
8851   enum tree_code c1 = TREE_CODE (t1), c2 = TREE_CODE (t2);
8852
8853   gcc_assert ((c1 == INTEGER_TYPE || c1 == REAL_TYPE || c1 == FIXED_POINT_TYPE)
8854               && (c2 == INTEGER_TYPE || c2 == REAL_TYPE
8855                   || c2 == FIXED_POINT_TYPE));
8856
8857   /* Equality works here because c_common_signed_type uses
8858      TYPE_MAIN_VARIANT.  */
8859   return c_common_signed_type (t1)
8860     == c_common_signed_type (t2);
8861 }
8862
8863 /* Check for missing format attributes on function pointers.  LTYPE is
8864    the new type or left-hand side type.  RTYPE is the old type or
8865    right-hand side type.  Returns TRUE if LTYPE is missing the desired
8866    attribute.  */
8867
8868 bool
8869 check_missing_format_attribute (tree ltype, tree rtype)
8870 {
8871   tree const ttr = TREE_TYPE (rtype), ttl = TREE_TYPE (ltype);
8872   tree ra;
8873
8874   for (ra = TYPE_ATTRIBUTES (ttr); ra; ra = TREE_CHAIN (ra))
8875     if (is_attribute_p ("format", TREE_PURPOSE (ra)))
8876       break;
8877   if (ra)
8878     {
8879       tree la;
8880       for (la = TYPE_ATTRIBUTES (ttl); la; la = TREE_CHAIN (la))
8881         if (is_attribute_p ("format", TREE_PURPOSE (la)))
8882           break;
8883       return !la;
8884     }
8885   else
8886     return false;
8887 }
8888
8889 /* Subscripting with type char is likely to lose on a machine where
8890    chars are signed.  So warn on any machine, but optionally.  Don't
8891    warn for unsigned char since that type is safe.  Don't warn for
8892    signed char because anyone who uses that must have done so
8893    deliberately. Furthermore, we reduce the false positive load by
8894    warning only for non-constant value of type char.  */
8895
8896 void
8897 warn_array_subscript_with_type_char (tree index)
8898 {
8899   if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node
8900       && TREE_CODE (index) != INTEGER_CST)
8901     warning (OPT_Wchar_subscripts, "array subscript has type %<char%>");
8902 }
8903
8904 /* Implement -Wparentheses for the unexpected C precedence rules, to
8905    cover cases like x + y << z which readers are likely to
8906    misinterpret.  We have seen an expression in which CODE is a binary
8907    operator used to combine expressions ARG_LEFT and ARG_RIGHT, which
8908    before folding had CODE_LEFT and CODE_RIGHT.  CODE_LEFT and
8909    CODE_RIGHT may be ERROR_MARK, which means that that side of the
8910    expression was not formed using a binary or unary operator, or it
8911    was enclosed in parentheses.  */
8912
8913 void
8914 warn_about_parentheses (enum tree_code code,
8915                         enum tree_code code_left, tree arg_left,
8916                         enum tree_code code_right, tree arg_right)
8917 {
8918   if (!warn_parentheses)
8919     return;
8920
8921   /* This macro tests that the expression ARG with original tree code
8922      CODE appears to be a boolean expression. or the result of folding a
8923      boolean expression.  */
8924 #define APPEARS_TO_BE_BOOLEAN_EXPR_P(CODE, ARG)                             \
8925         (truth_value_p (TREE_CODE (ARG))                                    \
8926          || TREE_CODE (TREE_TYPE (ARG)) == BOOLEAN_TYPE                     \
8927          /* Folding may create 0 or 1 integers from other expressions.  */  \
8928          || ((CODE) != INTEGER_CST                                          \
8929              && (integer_onep (ARG) || integer_zerop (ARG))))
8930
8931   switch (code)
8932     {
8933     case LSHIFT_EXPR:
8934       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8935         warning (OPT_Wparentheses,
8936                  "suggest parentheses around %<+%> inside %<<<%>");
8937       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8938         warning (OPT_Wparentheses,
8939                  "suggest parentheses around %<-%> inside %<<<%>");
8940       return;
8941
8942     case RSHIFT_EXPR:
8943       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8944         warning (OPT_Wparentheses,
8945                  "suggest parentheses around %<+%> inside %<>>%>");
8946       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8947         warning (OPT_Wparentheses,
8948                  "suggest parentheses around %<-%> inside %<>>%>");
8949       return;
8950
8951     case TRUTH_ORIF_EXPR:
8952       if (code_left == TRUTH_ANDIF_EXPR || code_right == TRUTH_ANDIF_EXPR)
8953         warning (OPT_Wparentheses,
8954                  "suggest parentheses around %<&&%> within %<||%>");
8955       return;
8956
8957     case BIT_IOR_EXPR:
8958       if (code_left == BIT_AND_EXPR || code_left == BIT_XOR_EXPR
8959           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
8960           || code_right == BIT_AND_EXPR || code_right == BIT_XOR_EXPR
8961           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
8962         warning (OPT_Wparentheses,
8963                  "suggest parentheses around arithmetic in operand of %<|%>");
8964       /* Check cases like x|y==z */
8965       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8966                || TREE_CODE_CLASS (code_right) == tcc_comparison)
8967         warning (OPT_Wparentheses,
8968                  "suggest parentheses around comparison in operand of %<|%>");
8969       /* Check cases like !x | y */
8970       else if (code_left == TRUTH_NOT_EXPR
8971                && !APPEARS_TO_BE_BOOLEAN_EXPR_P (code_right, arg_right))
8972         warning (OPT_Wparentheses, "suggest parentheses around operand of "
8973                  "%<!%> or change %<|%> to %<||%> or %<!%> to %<~%>");
8974       return;
8975
8976     case BIT_XOR_EXPR:
8977       if (code_left == BIT_AND_EXPR
8978           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
8979           || code_right == BIT_AND_EXPR
8980           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
8981         warning (OPT_Wparentheses,
8982                  "suggest parentheses around arithmetic in operand of %<^%>");
8983       /* Check cases like x^y==z */
8984       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8985                || TREE_CODE_CLASS (code_right) == tcc_comparison)
8986         warning (OPT_Wparentheses,
8987                  "suggest parentheses around comparison in operand of %<^%>");
8988       return;
8989
8990     case BIT_AND_EXPR:
8991       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8992         warning (OPT_Wparentheses,
8993                  "suggest parentheses around %<+%> in operand of %<&%>");
8994       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8995         warning (OPT_Wparentheses,
8996                  "suggest parentheses around %<-%> in operand of %<&%>");
8997       /* Check cases like x&y==z */
8998       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8999                || TREE_CODE_CLASS (code_right) == tcc_comparison)
9000         warning (OPT_Wparentheses,
9001                  "suggest parentheses around comparison in operand of %<&%>");
9002       /* Check cases like !x & y */
9003       else if (code_left == TRUTH_NOT_EXPR
9004                && !APPEARS_TO_BE_BOOLEAN_EXPR_P (code_right, arg_right))
9005         warning (OPT_Wparentheses, "suggest parentheses around operand of "
9006                  "%<!%> or change %<&%> to %<&&%> or %<!%> to %<~%>");
9007       return;
9008
9009     case EQ_EXPR:
9010       if (TREE_CODE_CLASS (code_left) == tcc_comparison
9011           || TREE_CODE_CLASS (code_right) == tcc_comparison)
9012         warning (OPT_Wparentheses,
9013                  "suggest parentheses around comparison in operand of %<==%>");
9014       return;
9015     case NE_EXPR:
9016       if (TREE_CODE_CLASS (code_left) == tcc_comparison
9017           || TREE_CODE_CLASS (code_right) == tcc_comparison)
9018         warning (OPT_Wparentheses,
9019                  "suggest parentheses around comparison in operand of %<!=%>");
9020       return;
9021
9022     default:
9023       if (TREE_CODE_CLASS (code) == tcc_comparison
9024            && ((TREE_CODE_CLASS (code_left) == tcc_comparison
9025                 && code_left != NE_EXPR && code_left != EQ_EXPR
9026                 && INTEGRAL_TYPE_P (TREE_TYPE (arg_left)))
9027                || (TREE_CODE_CLASS (code_right) == tcc_comparison
9028                    && code_right != NE_EXPR && code_right != EQ_EXPR
9029                    && INTEGRAL_TYPE_P (TREE_TYPE (arg_right)))))
9030         warning (OPT_Wparentheses, "comparisons like %<X<=Y<=Z%> do not "
9031                  "have their mathematical meaning");
9032       return;
9033     }
9034 #undef NOT_A_BOOLEAN_EXPR_P
9035 }
9036
9037 /* If LABEL (a LABEL_DECL) has not been used, issue a warning.  */
9038
9039 void
9040 warn_for_unused_label (tree label)
9041 {
9042   if (!TREE_USED (label))
9043     {
9044       if (DECL_INITIAL (label))
9045         warning (OPT_Wunused_label, "label %q+D defined but not used", label);
9046       else
9047         warning (OPT_Wunused_label, "label %q+D declared but not defined", label);
9048     }
9049 }
9050
9051 #ifndef TARGET_HAS_TARGETCM
9052 struct gcc_targetcm targetcm = TARGETCM_INITIALIZER;
9053 #endif
9054
9055 /* Warn for division by zero according to the value of DIVISOR.  LOC
9056    is the location of the division operator.  */
9057
9058 void
9059 warn_for_div_by_zero (location_t loc, tree divisor)
9060 {
9061   /* If DIVISOR is zero, and has integral or fixed-point type, issue a warning
9062      about division by zero.  Do not issue a warning if DIVISOR has a
9063      floating-point type, since we consider 0.0/0.0 a valid way of
9064      generating a NaN.  */
9065   if (c_inhibit_evaluation_warnings == 0
9066       && (integer_zerop (divisor) || fixed_zerop (divisor)))
9067     warning_at (loc, OPT_Wdiv_by_zero, "division by zero");
9068 }
9069
9070 /* Subroutine of build_binary_op. Give warnings for comparisons
9071    between signed and unsigned quantities that may fail. Do the
9072    checking based on the original operand trees ORIG_OP0 and ORIG_OP1,
9073    so that casts will be considered, but default promotions won't
9074    be.
9075
9076    LOCATION is the location of the comparison operator.
9077
9078    The arguments of this function map directly to local variables
9079    of build_binary_op.  */
9080
9081 void
9082 warn_for_sign_compare (location_t location,
9083                        tree orig_op0, tree orig_op1,
9084                        tree op0, tree op1,
9085                        tree result_type, enum tree_code resultcode)
9086 {
9087   int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
9088   int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
9089   int unsignedp0, unsignedp1;
9090
9091   /* In C++, check for comparison of different enum types.  */
9092   if (c_dialect_cxx()
9093       && TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
9094       && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
9095       && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
9096          != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
9097     {
9098       warning_at (location,
9099                   OPT_Wsign_compare, "comparison between types %qT and %qT",
9100                   TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
9101     }
9102
9103   /* Do not warn if the comparison is being done in a signed type,
9104      since the signed type will only be chosen if it can represent
9105      all the values of the unsigned type.  */
9106   if (!TYPE_UNSIGNED (result_type))
9107     /* OK */;
9108   /* Do not warn if both operands are unsigned.  */
9109   else if (op0_signed == op1_signed)
9110     /* OK */;
9111   else
9112     {
9113       tree sop, uop, base_type;
9114       bool ovf;
9115
9116       if (op0_signed)
9117         sop = orig_op0, uop = orig_op1;
9118       else
9119         sop = orig_op1, uop = orig_op0;
9120
9121       STRIP_TYPE_NOPS (sop);
9122       STRIP_TYPE_NOPS (uop);
9123       base_type = (TREE_CODE (result_type) == COMPLEX_TYPE
9124                    ? TREE_TYPE (result_type) : result_type);
9125
9126       /* Do not warn if the signed quantity is an unsuffixed integer
9127          literal (or some static constant expression involving such
9128          literals or a conditional expression involving such literals)
9129          and it is non-negative.  */
9130       if (tree_expr_nonnegative_warnv_p (sop, &ovf))
9131         /* OK */;
9132       /* Do not warn if the comparison is an equality operation, the
9133          unsigned quantity is an integral constant, and it would fit
9134          in the result if the result were signed.  */
9135       else if (TREE_CODE (uop) == INTEGER_CST
9136                && (resultcode == EQ_EXPR || resultcode == NE_EXPR)
9137                && int_fits_type_p (uop, c_common_signed_type (base_type)))
9138         /* OK */;
9139       /* In C, do not warn if the unsigned quantity is an enumeration
9140          constant and its maximum value would fit in the result if the
9141          result were signed.  */
9142       else if (!c_dialect_cxx() && TREE_CODE (uop) == INTEGER_CST
9143                && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE
9144                && int_fits_type_p (TYPE_MAX_VALUE (TREE_TYPE (uop)),
9145                                    c_common_signed_type (base_type)))
9146         /* OK */;
9147       else
9148         warning_at (location,
9149                     OPT_Wsign_compare,
9150                     "comparison between signed and unsigned integer expressions");
9151     }
9152
9153   /* Warn if two unsigned values are being compared in a size larger
9154      than their original size, and one (and only one) is the result of
9155      a `~' operator.  This comparison will always fail.
9156
9157      Also warn if one operand is a constant, and the constant does not
9158      have all bits set that are set in the ~ operand when it is
9159      extended.  */
9160
9161   op0 = get_narrower (op0, &unsignedp0);
9162   op1 = get_narrower (op1, &unsignedp1);
9163
9164   if ((TREE_CODE (op0) == BIT_NOT_EXPR)
9165       ^ (TREE_CODE (op1) == BIT_NOT_EXPR))
9166     {
9167       if (TREE_CODE (op0) == BIT_NOT_EXPR)
9168         op0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
9169       if (TREE_CODE (op1) == BIT_NOT_EXPR)
9170         op1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
9171
9172       if (host_integerp (op0, 0) || host_integerp (op1, 0))
9173         {
9174           tree primop;
9175           HOST_WIDE_INT constant, mask;
9176           int unsignedp;
9177           unsigned int bits;
9178
9179           if (host_integerp (op0, 0))
9180             {
9181               primop = op1;
9182               unsignedp = unsignedp1;
9183               constant = tree_low_cst (op0, 0);
9184             }
9185           else
9186             {
9187               primop = op0;
9188               unsignedp = unsignedp0;
9189               constant = tree_low_cst (op1, 0);
9190             }
9191
9192           bits = TYPE_PRECISION (TREE_TYPE (primop));
9193           if (bits < TYPE_PRECISION (result_type)
9194               && bits < HOST_BITS_PER_LONG && unsignedp)
9195             {
9196               mask = (~ (HOST_WIDE_INT) 0) << bits;
9197               if ((mask & constant) != mask)
9198                 {
9199                   if (constant == 0)
9200                     warning (OPT_Wsign_compare,
9201                              "promoted ~unsigned is always non-zero");
9202                   else
9203                     warning_at (location, OPT_Wsign_compare,
9204                                 "comparison of promoted ~unsigned with constant");
9205                 }
9206             }
9207         }
9208       else if (unsignedp0 && unsignedp1
9209                && (TYPE_PRECISION (TREE_TYPE (op0))
9210                    < TYPE_PRECISION (result_type))
9211                && (TYPE_PRECISION (TREE_TYPE (op1))
9212                    < TYPE_PRECISION (result_type)))
9213         warning_at (location, OPT_Wsign_compare,
9214                  "comparison of promoted ~unsigned with unsigned");
9215     }
9216 }
9217
9218 /* Setup a TYPE_DECL node as a typedef representation.
9219
9220    X is a TYPE_DECL for a typedef statement.  Create a brand new
9221    ..._TYPE node (which will be just a variant of the existing
9222    ..._TYPE node with identical properties) and then install X
9223    as the TYPE_NAME of this brand new (duplicate) ..._TYPE node.
9224
9225    The whole point here is to end up with a situation where each
9226    and every ..._TYPE node the compiler creates will be uniquely
9227    associated with AT MOST one node representing a typedef name.
9228    This way, even though the compiler substitutes corresponding
9229    ..._TYPE nodes for TYPE_DECL (i.e. "typedef name") nodes very
9230    early on, later parts of the compiler can always do the reverse
9231    translation and get back the corresponding typedef name.  For
9232    example, given:
9233
9234         typedef struct S MY_TYPE;
9235         MY_TYPE object;
9236
9237    Later parts of the compiler might only know that `object' was of
9238    type `struct S' if it were not for code just below.  With this
9239    code however, later parts of the compiler see something like:
9240
9241         struct S' == struct S
9242         typedef struct S' MY_TYPE;
9243         struct S' object;
9244
9245     And they can then deduce (from the node for type struct S') that
9246     the original object declaration was:
9247
9248                 MY_TYPE object;
9249
9250     Being able to do this is important for proper support of protoize,
9251     and also for generating precise symbolic debugging information
9252     which takes full account of the programmer's (typedef) vocabulary.
9253
9254     Obviously, we don't want to generate a duplicate ..._TYPE node if
9255     the TYPE_DECL node that we are now processing really represents a
9256     standard built-in type.  */
9257
9258 void
9259 set_underlying_type (tree x)
9260 {
9261   if (x == error_mark_node)
9262     return;
9263   if (DECL_IS_BUILTIN (x))
9264     {
9265       if (TYPE_NAME (TREE_TYPE (x)) == 0)
9266         TYPE_NAME (TREE_TYPE (x)) = x;
9267     }
9268   else if (TREE_TYPE (x) != error_mark_node
9269            && DECL_ORIGINAL_TYPE (x) == NULL_TREE)
9270     {
9271       tree tt = TREE_TYPE (x);
9272       DECL_ORIGINAL_TYPE (x) = tt;
9273       tt = build_variant_type_copy (tt);
9274       TYPE_STUB_DECL (tt) = TYPE_STUB_DECL (DECL_ORIGINAL_TYPE (x));
9275       TYPE_NAME (tt) = x;
9276       TREE_USED (tt) = TREE_USED (x);
9277       TREE_TYPE (x) = tt;
9278     }
9279 }
9280
9281 /* Returns true if X is a typedef decl.  */
9282
9283 bool
9284 is_typedef_decl (tree x)
9285 {
9286   return (x && TREE_CODE (x) == TYPE_DECL
9287           && DECL_ORIGINAL_TYPE (x) != NULL_TREE);
9288 }
9289
9290 /* Record the types used by the current global variable declaration
9291    being parsed, so that we can decide later to emit their debug info.
9292    Those types are in types_used_by_cur_var_decl, and we are going to
9293    store them in the types_used_by_vars_hash hash table.
9294    DECL is the declaration of the global variable that has been parsed.  */
9295
9296 void
9297 record_types_used_by_current_var_decl (tree decl)
9298 {
9299   gcc_assert (decl && DECL_P (decl) && TREE_STATIC (decl));
9300
9301   if (types_used_by_cur_var_decl)
9302     {
9303       tree node;
9304       for (node = types_used_by_cur_var_decl;
9305            node;
9306            node = TREE_CHAIN (node))
9307       {
9308         tree type = TREE_PURPOSE (node);
9309         types_used_by_var_decl_insert (type, decl);
9310       }
9311       types_used_by_cur_var_decl = NULL;
9312     }
9313 }
9314
9315 /* The C and C++ parsers both use vectors to hold function arguments.
9316    For efficiency, we keep a cache of unused vectors.  This is the
9317    cache.  */
9318
9319 typedef VEC(tree,gc)* tree_gc_vec;
9320 DEF_VEC_P(tree_gc_vec);
9321 DEF_VEC_ALLOC_P(tree_gc_vec,gc);
9322 static GTY((deletable)) VEC(tree_gc_vec,gc) *tree_vector_cache;
9323
9324 /* Return a new vector from the cache.  If the cache is empty,
9325    allocate a new vector.  These vectors are GC'ed, so it is OK if the
9326    pointer is not released..  */
9327
9328 VEC(tree,gc) *
9329 make_tree_vector (void)
9330 {
9331   if (!VEC_empty (tree_gc_vec, tree_vector_cache))
9332     return VEC_pop (tree_gc_vec, tree_vector_cache);
9333   else
9334     {
9335       /* Passing 0 to VEC_alloc returns NULL, and our callers require
9336          that we always return a non-NULL value.  The vector code uses
9337          4 when growing a NULL vector, so we do too.  */
9338       return VEC_alloc (tree, gc, 4);
9339     }
9340 }
9341
9342 /* Release a vector of trees back to the cache.  */
9343
9344 void
9345 release_tree_vector (VEC(tree,gc) *vec)
9346 {
9347   if (vec != NULL)
9348     {
9349       VEC_truncate (tree, vec, 0);
9350       VEC_safe_push (tree_gc_vec, gc, tree_vector_cache, vec);
9351     }
9352 }
9353
9354 /* Get a new tree vector holding a single tree.  */
9355
9356 VEC(tree,gc) *
9357 make_tree_vector_single (tree t)
9358 {
9359   VEC(tree,gc) *ret = make_tree_vector ();
9360   VEC_quick_push (tree, ret, t);
9361   return ret;
9362 }
9363
9364 /* Get a new tree vector which is a copy of an existing one.  */
9365
9366 VEC(tree,gc) *
9367 make_tree_vector_copy (const VEC(tree,gc) *orig)
9368 {
9369   VEC(tree,gc) *ret;
9370   unsigned int ix;
9371   tree t;
9372
9373   ret = make_tree_vector ();
9374   VEC_reserve (tree, gc, ret, VEC_length (tree, orig));
9375   for (ix = 0; VEC_iterate (tree, orig, ix, t); ++ix)
9376     VEC_quick_push (tree, ret, t);
9377   return ret;
9378 }
9379
9380 #include "gt-c-common.h"