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, 2010
   4    Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "intl.h"
  27 #include "tree.h"
  28 #include "flags.h"
  29 #include "output.h"
  30 #include "c-pragma.h"
  31 #include "rtl.h"
  32 #include "ggc.h"
  33 #include "varray.h"
  34 #include "expr.h"
  35 #include "c-common.h"
  36 #include "tm_p.h"
  37 #include "obstack.h"
  38 #include "cpplib.h"
  39 #include "target.h"
  40 #include "langhooks.h"
  41 #include "tree-inline.h"
  42 #include "c-tree.h"
  43 #include "toplev.h"
  44 #include "diagnostic.h"
  45 #include "tree-iterator.h"
  46 #include "hashtab.h"
  47 #include "tree-mudflap.h"
  48 #include "opts.h"
  49 #include "real.h"
  50 #include "cgraph.h"
  51 #include "target-def.h"
  52 #include "gimple.h"
  53 #include "fixed-value.h"
  54 #include "libfuncs.h"
  55
  56 cpp_reader *parse_in;           /* Declared in c-pragma.h.  */
  57
  58 /* The following symbols are subsumed in the c_global_trees array, and
  59    listed here individually for documentation purposes.
  60
  61    INTEGER_TYPE and REAL_TYPE nodes for the standard data types.
  62
  63         tree short_integer_type_node;
  64         tree long_integer_type_node;
  65         tree long_long_integer_type_node;
  66
  67         tree short_unsigned_type_node;
  68         tree long_unsigned_type_node;
  69         tree long_long_unsigned_type_node;
  70
  71         tree truthvalue_type_node;
  72         tree truthvalue_false_node;
  73         tree truthvalue_true_node;
  74
  75         tree ptrdiff_type_node;
  76
  77         tree unsigned_char_type_node;
  78         tree signed_char_type_node;
  79         tree wchar_type_node;
  80
  81         tree char16_type_node;
  82         tree char32_type_node;
  83
  84         tree float_type_node;
  85         tree double_type_node;
  86         tree long_double_type_node;
  87
  88         tree complex_integer_type_node;
  89         tree complex_float_type_node;
  90         tree complex_double_type_node;
  91         tree complex_long_double_type_node;
  92
  93         tree dfloat32_type_node;
  94         tree dfloat64_type_node;
  95         tree_dfloat128_type_node;
  96
  97         tree intQI_type_node;
  98         tree intHI_type_node;
  99         tree intSI_type_node;
 100         tree intDI_type_node;
 101         tree intTI_type_node;
 102
 103         tree unsigned_intQI_type_node;
 104         tree unsigned_intHI_type_node;
 105         tree unsigned_intSI_type_node;
 106         tree unsigned_intDI_type_node;
 107         tree unsigned_intTI_type_node;
 108
 109         tree widest_integer_literal_type_node;
 110         tree widest_unsigned_literal_type_node;
 111
 112    Nodes for types `void *' and `const void *'.
 113
 114         tree ptr_type_node, const_ptr_type_node;
 115
 116    Nodes for types `char *' and `const char *'.
 117
 118         tree string_type_node, const_string_type_node;
 119
 120    Type `char[SOMENUMBER]'.
 121    Used when an array of char is needed and the size is irrelevant.
 122
 123         tree char_array_type_node;
 124
 125    Type `int[SOMENUMBER]' or something like it.
 126    Used when an array of int needed and the size is irrelevant.
 127
 128         tree int_array_type_node;
 129
 130    Type `wchar_t[SOMENUMBER]' or something like it.
 131    Used when a wide string literal is created.
 132
 133         tree wchar_array_type_node;
 134
 135    Type `char16_t[SOMENUMBER]' or something like it.
 136    Used when a UTF-16 string literal is created.
 137
 138         tree char16_array_type_node;
 139
 140    Type `char32_t[SOMENUMBER]' or something like it.
 141    Used when a UTF-32 string literal is created.
 142
 143         tree char32_array_type_node;
 144
 145    Type `int ()' -- used for implicit declaration of functions.
 146
 147         tree default_function_type;
 148
 149    A VOID_TYPE node, packaged in a TREE_LIST.
 150
 151         tree void_list_node;
 152
 153   The lazily created VAR_DECLs for __FUNCTION__, __PRETTY_FUNCTION__,
 154   and __func__. (C doesn't generate __FUNCTION__ and__PRETTY_FUNCTION__
 155   VAR_DECLS, but C++ does.)
 156
 157         tree function_name_decl_node;
 158         tree pretty_function_name_decl_node;
 159         tree c99_function_name_decl_node;
 160
 161   Stack of nested function name VAR_DECLs.
 162
 163         tree saved_function_name_decls;
 164
 165 */
 166
 167 tree c_global_trees[CTI_MAX];
 168 \f
 169 /* Switches common to the C front ends.  */
 170
 171 /* Nonzero if preprocessing only.  */
 172
 173 int flag_preprocess_only;
 174
 175 /* Nonzero means don't output line number information.  */
 176
 177 char flag_no_line_commands;
 178
 179 /* Nonzero causes -E output not to be done, but directives such as
 180    #define that have side effects are still obeyed.  */
 181
 182 char flag_no_output;
 183
 184 /* Nonzero means dump macros in some fashion.  */
 185
 186 char flag_dump_macros;
 187
 188 /* Nonzero means pass #include lines through to the output.  */
 189
 190 char flag_dump_includes;
 191
 192 /* Nonzero means process PCH files while preprocessing.  */
 193
 194 bool flag_pch_preprocess;
 195
 196 /* The file name to which we should write a precompiled header, or
 197    NULL if no header will be written in this compile.  */
 198
 199 const char *pch_file;
 200
 201 /* Nonzero if an ISO standard was selected.  It rejects macros in the
 202    user's namespace.  */
 203 int flag_iso;
 204
 205 /* Nonzero if -undef was given.  It suppresses target built-in macros
 206    and assertions.  */
 207 int flag_undef;
 208
 209 /* Nonzero means don't recognize the non-ANSI builtin functions.  */
 210
 211 int flag_no_builtin;
 212
 213 /* Nonzero means don't recognize the non-ANSI builtin functions.
 214    -ansi sets this.  */
 215
 216 int flag_no_nonansi_builtin;
 217
 218 /* Nonzero means give `double' the same size as `float'.  */
 219
 220 int flag_short_double;
 221
 222 /* Nonzero means give `wchar_t' the same size as `short'.  */
 223
 224 int flag_short_wchar;
 225
 226 /* Nonzero means allow implicit conversions between vectors with
 227    differing numbers of subparts and/or differing element types.  */
 228 int flag_lax_vector_conversions;
 229
 230 /* Nonzero means allow Microsoft extensions without warnings or errors.  */
 231 int flag_ms_extensions;
 232
 233 /* Nonzero means don't recognize the keyword `asm'.  */
 234
 235 int flag_no_asm;
 236
 237 /* Nonzero means to treat bitfields as signed unless they say `unsigned'.  */
 238
 239 int flag_signed_bitfields = 1;
 240
 241 /* Warn about #pragma directives that are not recognized.  */
 242
 243 int warn_unknown_pragmas; /* Tri state variable.  */
 244
 245 /* Warn about format/argument anomalies in calls to formatted I/O functions
 246    (*printf, *scanf, strftime, strfmon, etc.).  */
 247
 248 int warn_format;
 249
 250 /* Warn about using __null (as NULL in C++) as sentinel.  For code compiled
 251    with GCC this doesn't matter as __null is guaranteed to have the right
 252    size.  */
 253
 254 int warn_strict_null_sentinel;
 255
 256 /* Zero means that faster, ...NonNil variants of objc_msgSend...
 257    calls will be used in ObjC; passing nil receivers to such calls
 258    will most likely result in crashes.  */
 259 int flag_nil_receivers = 1;
 260
 261 /* Nonzero means that code generation will be altered to support
 262    "zero-link" execution.  This currently affects ObjC only, but may
 263    affect other languages in the future.  */
 264 int flag_zero_link = 0;
 265
 266 /* Nonzero means emit an '__OBJC, __image_info' for the current translation
 267    unit.  It will inform the ObjC runtime that class definition(s) herein
 268    contained are to replace one(s) previously loaded.  */
 269 int flag_replace_objc_classes = 0;
 270
 271 /* C/ObjC language option variables.  */
 272
 273
 274 /* Nonzero means allow type mismatches in conditional expressions;
 275    just make their values `void'.  */
 276
 277 int flag_cond_mismatch;
 278
 279 /* Nonzero means enable C89 Amendment 1 features.  */
 280
 281 int flag_isoc94;
 282
 283 /* Nonzero means use the ISO C99 dialect of C.  */
 284
 285 int flag_isoc99;
 286
 287 /* Nonzero means that we have builtin functions, and main is an int.  */
 288
 289 int flag_hosted = 1;
 290
 291
 292 /* ObjC language option variables.  */
 293
 294
 295 /* Open and close the file for outputting class declarations, if
 296    requested (ObjC).  */
 297
 298 int flag_gen_declaration;
 299
 300 /* Tells the compiler that this is a special run.  Do not perform any
 301    compiling, instead we are to test some platform dependent features
 302    and output a C header file with appropriate definitions.  */
 303
 304 int print_struct_values;
 305
 306 /* Tells the compiler what is the constant string class for ObjC.  */
 307
 308 const char *constant_string_class_name;
 309
 310
 311 /* C++ language option variables.  */
 312
 313
 314 /* Nonzero means don't recognize any extension keywords.  */
 315
 316 int flag_no_gnu_keywords;
 317
 318 /* Nonzero means do emit exported implementations of functions even if
 319    they can be inlined.  */
 320
 321 int flag_implement_inlines = 1;
 322
 323 /* Nonzero means that implicit instantiations will be emitted if needed.  */
 324
 325 int flag_implicit_templates = 1;
 326
 327 /* Nonzero means that implicit instantiations of inline templates will be
 328    emitted if needed, even if instantiations of non-inline templates
 329    aren't.  */
 330
 331 int flag_implicit_inline_templates = 1;
 332
 333 /* Nonzero means generate separate instantiation control files and
 334    juggle them at link time.  */
 335
 336 int flag_use_repository;
 337
 338 /* Nonzero if we want to issue diagnostics that the standard says are not
 339    required.  */
 340
 341 int flag_optional_diags = 1;
 342
 343 /* Nonzero means we should attempt to elide constructors when possible.  */
 344
 345 int flag_elide_constructors = 1;
 346
 347 /* Nonzero means that member functions defined in class scope are
 348    inline by default.  */
 349
 350 int flag_default_inline = 1;
 351
 352 /* Controls whether compiler generates 'type descriptor' that give
 353    run-time type information.  */
 354
 355 int flag_rtti = 1;
 356
 357 /* Nonzero if we want to conserve space in the .o files.  We do this
 358    by putting uninitialized data and runtime initialized data into
 359    .common instead of .data at the expense of not flagging multiple
 360    definitions.  */
 361
 362 int flag_conserve_space;
 363
 364 /* Nonzero if we want to obey access control semantics.  */
 365
 366 int flag_access_control = 1;
 367
 368 /* Nonzero if we want to check the return value of new and avoid calling
 369    constructors if it is a null pointer.  */
 370
 371 int flag_check_new;
 372
 373 /* The C++ dialect being used. C++98 is the default.  */
 374
 375 enum cxx_dialect cxx_dialect = cxx98;
 376
 377 /* Nonzero if we want the new ISO rules for pushing a new scope for `for'
 378    initialization variables.
 379    0: Old rules, set by -fno-for-scope.
 380    2: New ISO rules, set by -ffor-scope.
 381    1: Try to implement new ISO rules, but with backup compatibility
 382    (and warnings).  This is the default, for now.  */
 383
 384 int flag_new_for_scope = 1;
 385
 386 /* Nonzero if we want to emit defined symbols with common-like linkage as
 387    weak symbols where possible, in order to conform to C++ semantics.
 388    Otherwise, emit them as local symbols.  */
 389
 390 int flag_weak = 1;
 391
 392 /* 0 means we want the preprocessor to not emit line directives for
 393    the current working directory.  1 means we want it to do it.  -1
 394    means we should decide depending on whether debugging information
 395    is being emitted or not.  */
 396
 397 int flag_working_directory = -1;
 398
 399 /* Nonzero to use __cxa_atexit, rather than atexit, to register
 400    destructors for local statics and global objects.  '2' means it has been
 401    set nonzero as a default, not by a command-line flag.  */
 402
 403 int flag_use_cxa_atexit = DEFAULT_USE_CXA_ATEXIT;
 404
 405 /* Nonzero to use __cxa_get_exception_ptr in C++ exception-handling
 406    code.  '2' means it has not been set explicitly on the command line.  */
 407
 408 int flag_use_cxa_get_exception_ptr = 2;
 409
 410 /* Nonzero means to implement standard semantics for exception
 411    specifications, calling unexpected if an exception is thrown that
 412    doesn't match the specification.  Zero means to treat them as
 413    assertions and optimize accordingly, but not check them.  */
 414
 415 int flag_enforce_eh_specs = 1;
 416
 417 /* Nonzero means to generate thread-safe code for initializing local
 418    statics.  */
 419
 420 int flag_threadsafe_statics = 1;
 421
 422 /* Nonzero if we want to pretty-print template specializations as the
 423    template signature followed by the arguments.  */
 424
 425 int flag_pretty_templates = 1;
 426
 427 /* Nonzero means warn about implicit declarations.  */
 428
 429 int warn_implicit = 1;
 430
 431 /* Maximum template instantiation depth.  This limit exists to limit the
 432    time it takes to notice infinite template instantiations; the default
 433    value of 1024 is likely to be in the next C++ standard.  */
 434
 435 int max_tinst_depth = 1024;
 436
 437
 438
 439 /* The elements of `ridpointers' are identifier nodes for the reserved
 440    type names and storage classes.  It is indexed by a RID_... value.  */
 441 tree *ridpointers;
 442
 443 tree (*make_fname_decl) (location_t, tree, int);
 444
 445 /* Nonzero means don't warn about problems that occur when the code is
 446    executed.  */
 447 int c_inhibit_evaluation_warnings;
 448
 449 /* Whether lexing has been completed, so subsequent preprocessor
 450    errors should use the compiler's input_location.  */
 451 bool done_lexing = false;
 452
 453 /* Information about how a function name is generated.  */
 454 struct fname_var_t
 455 {
 456   tree *const decl;     /* pointer to the VAR_DECL.  */
 457   const unsigned rid;   /* RID number for the identifier.  */
 458   const int pretty;     /* How pretty is it? */
 459 };
 460
 461 /* The three ways of getting then name of the current function.  */
 462
 463 const struct fname_var_t fname_vars[] =
 464 {
 465   /* C99 compliant __func__, must be first.  */
 466   {&c99_function_name_decl_node, RID_C99_FUNCTION_NAME, 0},
 467   /* GCC __FUNCTION__ compliant.  */
 468   {&function_name_decl_node, RID_FUNCTION_NAME, 0},
 469   /* GCC __PRETTY_FUNCTION__ compliant.  */
 470   {&pretty_function_name_decl_node, RID_PRETTY_FUNCTION_NAME, 1},
 471   {NULL, 0, 0},
 472 };
 473
 474 static tree c_fully_fold_internal (tree expr, bool, bool *, bool *);
 475 static tree check_case_value (tree);
 476 static bool check_case_bounds (tree, tree, tree *, tree *);
 477
 478 static tree handle_packed_attribute (tree *, tree, tree, int, bool *);
 479 static tree handle_nocommon_attribute (tree *, tree, tree, int, bool *);
 480 static tree handle_common_attribute (tree *, tree, tree, int, bool *);
 481 static tree handle_noreturn_attribute (tree *, tree, tree, int, bool *);
 482 static tree handle_hot_attribute (tree *, tree, tree, int, bool *);
 483 static tree handle_cold_attribute (tree *, tree, tree, int, bool *);
 484 static tree handle_noinline_attribute (tree *, tree, tree, int, bool *);
 485 static tree handle_noclone_attribute (tree *, tree, tree, int, bool *);
 486 static tree handle_always_inline_attribute (tree *, tree, tree, int,
 487                                             bool *);
 488 static tree handle_gnu_inline_attribute (tree *, tree, tree, int, bool *);
 489 static tree handle_artificial_attribute (tree *, tree, tree, int, bool *);
 490 static tree handle_flatten_attribute (tree *, tree, tree, int, bool *);
 491 static tree handle_error_attribute (tree *, tree, tree, int, bool *);
 492 static tree handle_used_attribute (tree *, tree, tree, int, bool *);
 493 static tree handle_unused_attribute (tree *, tree, tree, int, bool *);
 494 static tree handle_externally_visible_attribute (tree *, tree, tree, int,
 495                                                  bool *);
 496 static tree handle_const_attribute (tree *, tree, tree, int, bool *);
 497 static tree handle_transparent_union_attribute (tree *, tree, tree,
 498                                                 int, bool *);
 499 static tree handle_constructor_attribute (tree *, tree, tree, int, bool *);
 500 static tree handle_destructor_attribute (tree *, tree, tree, int, bool *);
 501 static tree handle_mode_attribute (tree *, tree, tree, int, bool *);
 502 static tree handle_section_attribute (tree *, tree, tree, int, bool *);
 503 static tree handle_aligned_attribute (tree *, tree, tree, int, bool *);
 504 static tree handle_weak_attribute (tree *, tree, tree, int, bool *) ;
 505 static tree handle_alias_attribute (tree *, tree, tree, int, bool *);
 506 static tree handle_weakref_attribute (tree *, tree, tree, int, bool *) ;
 507 static tree handle_visibility_attribute (tree *, tree, tree, int,
 508                                          bool *);
 509 static tree handle_tls_model_attribute (tree *, tree, tree, int,
 510                                         bool *);
 511 static tree handle_no_instrument_function_attribute (tree *, tree,
 512                                                      tree, int, bool *);
 513 static tree handle_malloc_attribute (tree *, tree, tree, int, bool *);
 514 static tree handle_returns_twice_attribute (tree *, tree, tree, int, bool *);
 515 static tree handle_no_limit_stack_attribute (tree *, tree, tree, int,
 516                                              bool *);
 517 static tree handle_pure_attribute (tree *, tree, tree, int, bool *);
 518 static tree handle_novops_attribute (tree *, tree, tree, int, bool *);
 519 static tree handle_deprecated_attribute (tree *, tree, tree, int,
 520                                          bool *);
 521 static tree handle_vector_size_attribute (tree *, tree, tree, int,
 522                                           bool *);
 523 static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *);
 524 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
 525 static tree handle_cleanup_attribute (tree *, tree, tree, int, bool *);
 526 static tree handle_warn_unused_result_attribute (tree *, tree, tree, int,
 527                                                  bool *);
 528 static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *);
 529 static tree handle_type_generic_attribute (tree *, tree, tree, int, bool *);
 530 static tree handle_alloc_size_attribute (tree *, tree, tree, int, bool *);
 531 static tree handle_target_attribute (tree *, tree, tree, int, bool *);
 532 static tree handle_optimize_attribute (tree *, tree, tree, int, bool *);
 533
 534 static void check_function_nonnull (tree, int, tree *);
 535 static void check_nonnull_arg (void *, tree, unsigned HOST_WIDE_INT);
 536 static bool nonnull_check_p (tree, unsigned HOST_WIDE_INT);
 537 static bool get_nonnull_operand (tree, unsigned HOST_WIDE_INT *);
 538 static int resort_field_decl_cmp (const void *, const void *);
 539
 540 /* Reserved words.  The third field is a mask: keywords are disabled
 541    if they match the mask.
 542
 543    Masks for languages:
 544    C --std=c89: D_C99 | D_CXXONLY | D_OBJC | D_CXX_OBJC
 545    C --std=c99: D_CXXONLY | D_OBJC
 546    ObjC is like C except that D_OBJC and D_CXX_OBJC are not set
 547    C++ --std=c98: D_CONLY | D_CXXOX | D_OBJC
 548    C++ --std=c0x: D_CONLY | D_OBJC
 549    ObjC++ is like C++ except that D_OBJC is not set
 550
 551    If -fno-asm is used, D_ASM is added to the mask.  If
 552    -fno-gnu-keywords is used, D_EXT is added.  If -fno-asm and C in
 553    C89 mode, D_EXT89 is added for both -fno-asm and -fno-gnu-keywords.
 554    In C with -Wc++-compat, we warn if D_CXXWARN is set.  */
 555
 556 const struct c_common_resword c_common_reswords[] =
 557 {
 558   { "_Bool",            RID_BOOL,      D_CONLY },
 559   { "_Complex",         RID_COMPLEX,    0 },
 560   { "_Imaginary",       RID_IMAGINARY, D_CONLY },
 561   { "_Decimal32",       RID_DFLOAT32,  D_CONLY | D_EXT },
 562   { "_Decimal64",       RID_DFLOAT64,  D_CONLY | D_EXT },
 563   { "_Decimal128",      RID_DFLOAT128, D_CONLY | D_EXT },
 564   { "_Fract",           RID_FRACT,     D_CONLY | D_EXT },
 565   { "_Accum",           RID_ACCUM,     D_CONLY | D_EXT },
 566   { "_Sat",             RID_SAT,       D_CONLY | D_EXT },
 567   { "__FUNCTION__",     RID_FUNCTION_NAME, 0 },
 568   { "__PRETTY_FUNCTION__", RID_PRETTY_FUNCTION_NAME, 0 },
 569   { "__alignof",        RID_ALIGNOF,    0 },
 570   { "__alignof__",      RID_ALIGNOF,    0 },
 571   { "__asm",            RID_ASM,        0 },
 572   { "__asm__",          RID_ASM,        0 },
 573   { "__attribute",      RID_ATTRIBUTE,  0 },
 574   { "__attribute__",    RID_ATTRIBUTE,  0 },
 575   { "__builtin_choose_expr", RID_CHOOSE_EXPR, D_CONLY },
 576   { "__builtin_offsetof", RID_OFFSETOF, 0 },
 577   { "__builtin_types_compatible_p", RID_TYPES_COMPATIBLE_P, D_CONLY },
 578   { "__builtin_va_arg", RID_VA_ARG,     0 },
 579   { "__complex",        RID_COMPLEX,    0 },
 580   { "__complex__",      RID_COMPLEX,    0 },
 581   { "__const",          RID_CONST,      0 },
 582   { "__const__",        RID_CONST,      0 },
 583   { "__decltype",       RID_DECLTYPE,   D_CXXONLY },
 584   { "__extension__",    RID_EXTENSION,  0 },
 585   { "__func__",         RID_C99_FUNCTION_NAME, 0 },
 586   { "__has_nothrow_assign", RID_HAS_NOTHROW_ASSIGN, D_CXXONLY },
 587   { "__has_nothrow_constructor", RID_HAS_NOTHROW_CONSTRUCTOR, D_CXXONLY },
 588   { "__has_nothrow_copy", RID_HAS_NOTHROW_COPY, D_CXXONLY },
 589   { "__has_trivial_assign", RID_HAS_TRIVIAL_ASSIGN, D_CXXONLY },
 590   { "__has_trivial_constructor", RID_HAS_TRIVIAL_CONSTRUCTOR, D_CXXONLY },
 591   { "__has_trivial_copy", RID_HAS_TRIVIAL_COPY, D_CXXONLY },
 592   { "__has_trivial_destructor", RID_HAS_TRIVIAL_DESTRUCTOR, D_CXXONLY },
 593   { "__has_virtual_destructor", RID_HAS_VIRTUAL_DESTRUCTOR, D_CXXONLY },
 594   { "__is_abstract",    RID_IS_ABSTRACT, D_CXXONLY },
 595   { "__is_base_of",     RID_IS_BASE_OF, D_CXXONLY },
 596   { "__is_class",       RID_IS_CLASS,   D_CXXONLY },
 597   { "__is_convertible_to", RID_IS_CONVERTIBLE_TO, D_CXXONLY },
 598   { "__is_empty",       RID_IS_EMPTY,   D_CXXONLY },
 599   { "__is_enum",        RID_IS_ENUM,    D_CXXONLY },
 600   { "__is_pod",         RID_IS_POD,     D_CXXONLY },
 601   { "__is_polymorphic", RID_IS_POLYMORPHIC, D_CXXONLY },
 602   { "__is_standard_layout", RID_IS_STD_LAYOUT, D_CXXONLY },
 603   { "__is_trivial",     RID_IS_TRIVIAL, D_CXXONLY },
 604   { "__is_union",       RID_IS_UNION,   D_CXXONLY },
 605   { "__imag",           RID_IMAGPART,   0 },
 606   { "__imag__",         RID_IMAGPART,   0 },
 607   { "__inline",         RID_INLINE,     0 },
 608   { "__inline__",       RID_INLINE,     0 },
 609   { "__label__",        RID_LABEL,      0 },
 610   { "__null",           RID_NULL,       0 },
 611   { "__real",           RID_REALPART,   0 },
 612   { "__real__",         RID_REALPART,   0 },
 613   { "__restrict",       RID_RESTRICT,   0 },
 614   { "__restrict__",     RID_RESTRICT,   0 },
 615   { "__signed",         RID_SIGNED,     0 },
 616   { "__signed__",       RID_SIGNED,     0 },
 617   { "__thread",         RID_THREAD,     0 },
 618   { "__typeof",         RID_TYPEOF,     0 },
 619   { "__typeof__",       RID_TYPEOF,     0 },
 620   { "__volatile",       RID_VOLATILE,   0 },
 621   { "__volatile__",     RID_VOLATILE,   0 },
 622   { "alignof",          RID_ALIGNOF,    D_CXXONLY | D_CXX0X | D_CXXWARN },
 623   { "asm",              RID_ASM,        D_ASM },
 624   { "auto",             RID_AUTO,       0 },
 625   { "bool",             RID_BOOL,       D_CXXONLY | D_CXXWARN },
 626   { "break",            RID_BREAK,      0 },
 627   { "case",             RID_CASE,       0 },
 628   { "catch",            RID_CATCH,      D_CXX_OBJC | D_CXXWARN },
 629   { "char",             RID_CHAR,       0 },
 630   { "char16_t",         RID_CHAR16,     D_CXXONLY | D_CXX0X | D_CXXWARN },
 631   { "char32_t",         RID_CHAR32,     D_CXXONLY | D_CXX0X | D_CXXWARN },
 632   { "class",            RID_CLASS,      D_CXX_OBJC | D_CXXWARN },
 633   { "const",            RID_CONST,      0 },
 634   { "constexpr",        RID_CONSTEXPR,  D_CXXONLY | D_CXX0X | D_CXXWARN },
 635   { "const_cast",       RID_CONSTCAST,  D_CXXONLY | D_CXXWARN },
 636   { "continue",         RID_CONTINUE,   0 },
 637   { "decltype",         RID_DECLTYPE,   D_CXXONLY | D_CXX0X | D_CXXWARN },
 638   { "default",          RID_DEFAULT,    0 },
 639   { "delete",           RID_DELETE,     D_CXXONLY | D_CXXWARN },
 640   { "do",               RID_DO,         0 },
 641   { "double",           RID_DOUBLE,     0 },
 642   { "dynamic_cast",     RID_DYNCAST,    D_CXXONLY | D_CXXWARN },
 643   { "else",             RID_ELSE,       0 },
 644   { "enum",             RID_ENUM,       0 },
 645   { "explicit",         RID_EXPLICIT,   D_CXXONLY | D_CXXWARN },
 646   { "export",           RID_EXPORT,     D_CXXONLY | D_CXXWARN },
 647   { "extern",           RID_EXTERN,     0 },
 648   { "false",            RID_FALSE,      D_CXXONLY | D_CXXWARN },
 649   { "float",            RID_FLOAT,      0 },
 650   { "for",              RID_FOR,        0 },
 651   { "friend",           RID_FRIEND,     D_CXXONLY | D_CXXWARN },
 652   { "goto",             RID_GOTO,       0 },
 653   { "if",               RID_IF,         0 },
 654   { "inline",           RID_INLINE,     D_EXT89 },
 655   { "int",              RID_INT,        0 },
 656   { "long",             RID_LONG,       0 },
 657   { "mutable",          RID_MUTABLE,    D_CXXONLY | D_CXXWARN },
 658   { "namespace",        RID_NAMESPACE,  D_CXXONLY | D_CXXWARN },
 659   { "new",              RID_NEW,        D_CXXONLY | D_CXXWARN },
 660   { "operator",         RID_OPERATOR,   D_CXXONLY | D_CXXWARN },
 661   { "private",          RID_PRIVATE,    D_CXX_OBJC | D_CXXWARN },
 662   { "protected",        RID_PROTECTED,  D_CXX_OBJC | D_CXXWARN },
 663   { "public",           RID_PUBLIC,     D_CXX_OBJC | D_CXXWARN },
 664   { "register",         RID_REGISTER,   0 },
 665   { "reinterpret_cast", RID_REINTCAST,  D_CXXONLY | D_CXXWARN },
 666   { "restrict",         RID_RESTRICT,   D_CONLY | D_C99 },
 667   { "return",           RID_RETURN,     0 },
 668   { "short",            RID_SHORT,      0 },
 669   { "signed",           RID_SIGNED,     0 },
 670   { "sizeof",           RID_SIZEOF,     0 },
 671   { "static",           RID_STATIC,     0 },
 672   { "static_assert",    RID_STATIC_ASSERT, D_CXXONLY | D_CXX0X | D_CXXWARN },
 673   { "static_cast",      RID_STATCAST,   D_CXXONLY | D_CXXWARN },
 674   { "struct",           RID_STRUCT,     0 },
 675   { "switch",           RID_SWITCH,     0 },
 676   { "template",         RID_TEMPLATE,   D_CXXONLY | D_CXXWARN },
 677   { "this",             RID_THIS,       D_CXXONLY | D_CXXWARN },
 678   { "throw",            RID_THROW,      D_CXX_OBJC | D_CXXWARN },
 679   { "true",             RID_TRUE,       D_CXXONLY | D_CXXWARN },
 680   { "try",              RID_TRY,        D_CXX_OBJC | D_CXXWARN },
 681   { "typedef",          RID_TYPEDEF,    0 },
 682   { "typename",         RID_TYPENAME,   D_CXXONLY | D_CXXWARN },
 683   { "typeid",           RID_TYPEID,     D_CXXONLY | D_CXXWARN },
 684   { "typeof",           RID_TYPEOF,     D_ASM | D_EXT },
 685   { "union",            RID_UNION,      0 },
 686   { "unsigned",         RID_UNSIGNED,   0 },
 687   { "using",            RID_USING,      D_CXXONLY | D_CXXWARN },
 688   { "virtual",          RID_VIRTUAL,    D_CXXONLY | D_CXXWARN },
 689   { "void",             RID_VOID,       0 },
 690   { "volatile",         RID_VOLATILE,   0 },
 691   { "wchar_t",          RID_WCHAR,      D_CXXONLY },
 692   { "while",            RID_WHILE,      0 },
 693   /* These Objective-C keywords are recognized only immediately after
 694      an '@'.  */
 695   { "compatibility_alias", RID_AT_ALIAS,        D_OBJC },
 696   { "defs",             RID_AT_DEFS,            D_OBJC },
 697   { "encode",           RID_AT_ENCODE,          D_OBJC },
 698   { "end",              RID_AT_END,             D_OBJC },
 699   { "implementation",   RID_AT_IMPLEMENTATION,  D_OBJC },
 700   { "interface",        RID_AT_INTERFACE,       D_OBJC },
 701   { "protocol",         RID_AT_PROTOCOL,        D_OBJC },
 702   { "selector",         RID_AT_SELECTOR,        D_OBJC },
 703   { "finally",          RID_AT_FINALLY,         D_OBJC },
 704   { "synchronized",     RID_AT_SYNCHRONIZED,    D_OBJC },
 705   /* These are recognized only in protocol-qualifier context
 706      (see above) */
 707   { "bycopy",           RID_BYCOPY,             D_OBJC },
 708   { "byref",            RID_BYREF,              D_OBJC },
 709   { "in",               RID_IN,                 D_OBJC },
 710   { "inout",            RID_INOUT,              D_OBJC },
 711   { "oneway",           RID_ONEWAY,             D_OBJC },
 712   { "out",              RID_OUT,                D_OBJC },
 713
 714 #ifdef TARGET_ADDR_SPACE_KEYWORDS
 715   /* Any address space keywords recognized by the target.  */
 716   TARGET_ADDR_SPACE_KEYWORDS,
 717 #endif
 718 };
 719
 720 const unsigned int num_c_common_reswords =
 721   sizeof c_common_reswords / sizeof (struct c_common_resword);
 722
 723 /* Table of machine-independent attributes common to all C-like languages.  */
 724 const struct attribute_spec c_common_attribute_table[] =
 725 {
 726   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 727   { "packed",                 0, 0, false, false, false,
 728                               handle_packed_attribute },
 729   { "nocommon",               0, 0, true,  false, false,
 730                               handle_nocommon_attribute },
 731   { "common",                 0, 0, true,  false, false,
 732                               handle_common_attribute },
 733   /* FIXME: logically, noreturn attributes should be listed as
 734      "false, true, true" and apply to function types.  But implementing this
 735      would require all the places in the compiler that use TREE_THIS_VOLATILE
 736      on a decl to identify non-returning functions to be located and fixed
 737      to check the function type instead.  */
 738   { "noreturn",               0, 0, true,  false, false,
 739                               handle_noreturn_attribute },
 740   { "volatile",               0, 0, true,  false, false,
 741                               handle_noreturn_attribute },
 742   { "noinline",               0, 0, true,  false, false,
 743                               handle_noinline_attribute },
 744   { "noclone",                0, 0, true,  false, false,
 745                               handle_noclone_attribute },
 746   { "always_inline",          0, 0, true,  false, false,
 747                               handle_always_inline_attribute },
 748   { "gnu_inline",             0, 0, true,  false, false,
 749                               handle_gnu_inline_attribute },
 750   { "artificial",             0, 0, true,  false, false,
 751                               handle_artificial_attribute },
 752   { "flatten",                0, 0, true,  false, false,
 753                               handle_flatten_attribute },
 754   { "used",                   0, 0, true,  false, false,
 755                               handle_used_attribute },
 756   { "unused",                 0, 0, false, false, false,
 757                               handle_unused_attribute },
 758   { "externally_visible",     0, 0, true,  false, false,
 759                               handle_externally_visible_attribute },
 760   /* The same comments as for noreturn attributes apply to const ones.  */
 761   { "const",                  0, 0, true,  false, false,
 762                               handle_const_attribute },
 763   { "transparent_union",      0, 0, false, false, false,
 764                               handle_transparent_union_attribute },
 765   { "constructor",            0, 1, true,  false, false,
 766                               handle_constructor_attribute },
 767   { "destructor",             0, 1, true,  false, false,
 768                               handle_destructor_attribute },
 769   { "mode",                   1, 1, false,  true, false,
 770                               handle_mode_attribute },
 771   { "section",                1, 1, true,  false, false,
 772                               handle_section_attribute },
 773   { "aligned",                0, 1, false, false, false,
 774                               handle_aligned_attribute },
 775   { "weak",                   0, 0, true,  false, false,
 776                               handle_weak_attribute },
 777   { "alias",                  1, 1, true,  false, false,
 778                               handle_alias_attribute },
 779   { "weakref",                0, 1, true,  false, false,
 780                               handle_weakref_attribute },
 781   { "no_instrument_function", 0, 0, true,  false, false,
 782                               handle_no_instrument_function_attribute },
 783   { "malloc",                 0, 0, true,  false, false,
 784                               handle_malloc_attribute },
 785   { "returns_twice",          0, 0, true,  false, false,
 786                               handle_returns_twice_attribute },
 787   { "no_stack_limit",         0, 0, true,  false, false,
 788                               handle_no_limit_stack_attribute },
 789   { "pure",                   0, 0, true,  false, false,
 790                               handle_pure_attribute },
 791   /* For internal use (marking of builtins) only.  The name contains space
 792      to prevent its usage in source code.  */
 793   { "no vops",                0, 0, true,  false, false,
 794                               handle_novops_attribute },
 795   { "deprecated",             0, 1, false, false, false,
 796                               handle_deprecated_attribute },
 797   { "vector_size",            1, 1, false, true, false,
 798                               handle_vector_size_attribute },
 799   { "visibility",             1, 1, false, false, false,
 800                               handle_visibility_attribute },
 801   { "tls_model",              1, 1, true,  false, false,
 802                               handle_tls_model_attribute },
 803   { "nonnull",                0, -1, false, true, true,
 804                               handle_nonnull_attribute },
 805   { "nothrow",                0, 0, true,  false, false,
 806                               handle_nothrow_attribute },
 807   { "may_alias",              0, 0, false, true, false, NULL },
 808   { "cleanup",                1, 1, true, false, false,
 809                               handle_cleanup_attribute },
 810   { "warn_unused_result",     0, 0, false, true, true,
 811                               handle_warn_unused_result_attribute },
 812   { "sentinel",               0, 1, false, true, true,
 813                               handle_sentinel_attribute },
 814   /* For internal use (marking of builtins) only.  The name contains space
 815      to prevent its usage in source code.  */
 816   { "type generic",           0, 0, false, true, true,
 817                               handle_type_generic_attribute },
 818   { "alloc_size",             1, 2, false, true, true,
 819                               handle_alloc_size_attribute },
 820   { "cold",                   0, 0, true,  false, false,
 821                               handle_cold_attribute },
 822   { "hot",                    0, 0, true,  false, false,
 823                               handle_hot_attribute },
 824   { "warning",                1, 1, true,  false, false,
 825                               handle_error_attribute },
 826   { "error",                  1, 1, true,  false, false,
 827                               handle_error_attribute },
 828   { "target",                 1, -1, true, false, false,
 829                               handle_target_attribute },
 830   { "optimize",               1, -1, true, false, false,
 831                               handle_optimize_attribute },
 832   { NULL,                     0, 0, false, false, false, NULL }
 833 };
 834
 835 /* Give the specifications for the format attributes, used by C and all
 836    descendants.  */
 837
 838 const struct attribute_spec c_common_format_attribute_table[] =
 839 {
 840   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 841   { "format",                 3, 3, false, true,  true,
 842                               handle_format_attribute },
 843   { "format_arg",             1, 1, false, true,  true,
 844                               handle_format_arg_attribute },
 845   { NULL,                     0, 0, false, false, false, NULL }
 846 };
 847
 848 /* Return identifier for address space AS.  */
 849 const char *
 850 c_addr_space_name (addr_space_t as)
 851 {
 852   unsigned int i;
 853
 854   for (i = 0; i < num_c_common_reswords; i++)
 855     if (c_common_reswords[i].rid == RID_FIRST_ADDR_SPACE + as)
 856       return c_common_reswords[i].word;
 857
 858   gcc_unreachable ();
 859 }
 860
 861 /* Push current bindings for the function name VAR_DECLS.  */
 862
 863 void
 864 start_fname_decls (void)
 865 {
 866   unsigned ix;
 867   tree saved = NULL_TREE;
 868
 869   for (ix = 0; fname_vars[ix].decl; ix++)
 870     {
 871       tree decl = *fname_vars[ix].decl;
 872
 873       if (decl)
 874         {
 875           saved = tree_cons (decl, build_int_cst (NULL_TREE, ix), saved);
 876           *fname_vars[ix].decl = NULL_TREE;
 877         }
 878     }
 879   if (saved || saved_function_name_decls)
 880     /* Normally they'll have been NULL, so only push if we've got a
 881        stack, or they are non-NULL.  */
 882     saved_function_name_decls = tree_cons (saved, NULL_TREE,
 883                                            saved_function_name_decls);
 884 }
 885
 886 /* Finish up the current bindings, adding them into the current function's
 887    statement tree.  This must be done _before_ finish_stmt_tree is called.
 888    If there is no current function, we must be at file scope and no statements
 889    are involved. Pop the previous bindings.  */
 890
 891 void
 892 finish_fname_decls (void)
 893 {
 894   unsigned ix;
 895   tree stmts = NULL_TREE;
 896   tree stack = saved_function_name_decls;
 897
 898   for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack))
 899     append_to_statement_list (TREE_VALUE (stack), &stmts);
 900
 901   if (stmts)
 902     {
 903       tree *bodyp = &DECL_SAVED_TREE (current_function_decl);
 904
 905       if (TREE_CODE (*bodyp) == BIND_EXPR)
 906         bodyp = &BIND_EXPR_BODY (*bodyp);
 907
 908       append_to_statement_list_force (*bodyp, &stmts);
 909       *bodyp = stmts;
 910     }
 911
 912   for (ix = 0; fname_vars[ix].decl; ix++)
 913     *fname_vars[ix].decl = NULL_TREE;
 914
 915   if (stack)
 916     {
 917       /* We had saved values, restore them.  */
 918       tree saved;
 919
 920       for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved))
 921         {
 922           tree decl = TREE_PURPOSE (saved);
 923           unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved));
 924
 925           *fname_vars[ix].decl = decl;
 926         }
 927       stack = TREE_CHAIN (stack);
 928     }
 929   saved_function_name_decls = stack;
 930 }
 931
 932 /* Return the text name of the current function, suitably prettified
 933    by PRETTY_P.  Return string must be freed by caller.  */
 934
 935 const char *
 936 fname_as_string (int pretty_p)
 937 {
 938   const char *name = "top level";
 939   char *namep;
 940   int vrb = 2, len;
 941   cpp_string cstr = { 0, 0 }, strname;
 942
 943   if (!pretty_p)
 944     {
 945       name = "";
 946       vrb = 0;
 947     }
 948
 949   if (current_function_decl)
 950     name = lang_hooks.decl_printable_name (current_function_decl, vrb);
 951
 952   len = strlen (name) + 3; /* Two for '"'s.  One for NULL.  */
 953
 954   namep = XNEWVEC (char, len);
 955   snprintf (namep, len, "\"%s\"", name);
 956   strname.text = (unsigned char *) namep;
 957   strname.len = len - 1;
 958
 959   if (cpp_interpret_string (parse_in, &strname, 1, &cstr, CPP_STRING))
 960     {
 961       XDELETEVEC (namep);
 962       return (const char *) cstr.text;
 963     }
 964
 965   return namep;
 966 }
 967
 968 /* Return the VAR_DECL for a const char array naming the current
 969    function. If the VAR_DECL has not yet been created, create it
 970    now. RID indicates how it should be formatted and IDENTIFIER_NODE
 971    ID is its name (unfortunately C and C++ hold the RID values of
 972    keywords in different places, so we can't derive RID from ID in
 973    this language independent code. LOC is the location of the
 974    function.  */
 975
 976 tree
 977 fname_decl (location_t loc, unsigned int rid, tree id)
 978 {
 979   unsigned ix;
 980   tree decl = NULL_TREE;
 981
 982   for (ix = 0; fname_vars[ix].decl; ix++)
 983     if (fname_vars[ix].rid == rid)
 984       break;
 985
 986   decl = *fname_vars[ix].decl;
 987   if (!decl)
 988     {
 989       /* If a tree is built here, it would normally have the lineno of
 990          the current statement.  Later this tree will be moved to the
 991          beginning of the function and this line number will be wrong.
 992          To avoid this problem set the lineno to 0 here; that prevents
 993          it from appearing in the RTL.  */
 994       tree stmts;
 995       location_t saved_location = input_location;
 996       input_location = UNKNOWN_LOCATION;
 997
 998       stmts = push_stmt_list ();
 999       decl = (*make_fname_decl) (loc, id, fname_vars[ix].pretty);
1000       stmts = pop_stmt_list (stmts);
1001       if (!IS_EMPTY_STMT (stmts))
1002         saved_function_name_decls
1003           = tree_cons (decl, stmts, saved_function_name_decls);
1004       *fname_vars[ix].decl = decl;
1005       input_location = saved_location;
1006     }
1007   if (!ix && !current_function_decl)
1008     pedwarn (loc, 0, "%qD is not defined outside of function scope", decl);
1009
1010   return decl;
1011 }
1012
1013 /* Given a STRING_CST, give it a suitable array-of-chars data type.  */
1014
1015 tree
1016 fix_string_type (tree value)
1017 {
1018   int length = TREE_STRING_LENGTH (value);
1019   int nchars;
1020   tree e_type, i_type, a_type;
1021
1022   /* Compute the number of elements, for the array type.  */
1023   if (TREE_TYPE (value) == char_array_type_node || !TREE_TYPE (value))
1024     {
1025       nchars = length;
1026       e_type = char_type_node;
1027     }
1028   else if (TREE_TYPE (value) == char16_array_type_node)
1029     {
1030       nchars = length / (TYPE_PRECISION (char16_type_node) / BITS_PER_UNIT);
1031       e_type = char16_type_node;
1032     }
1033   else if (TREE_TYPE (value) == char32_array_type_node)
1034     {
1035       nchars = length / (TYPE_PRECISION (char32_type_node) / BITS_PER_UNIT);
1036       e_type = char32_type_node;
1037     }
1038   else
1039     {
1040       nchars = length / (TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT);
1041       e_type = wchar_type_node;
1042     }
1043
1044   /* C89 2.2.4.1, C99 5.2.4.1 (Translation limits).  The analogous
1045      limit in C++98 Annex B is very large (65536) and is not normative,
1046      so we do not diagnose it (warn_overlength_strings is forced off
1047      in c_common_post_options).  */
1048   if (warn_overlength_strings)
1049     {
1050       const int nchars_max = flag_isoc99 ? 4095 : 509;
1051       const int relevant_std = flag_isoc99 ? 99 : 90;
1052       if (nchars - 1 > nchars_max)
1053         /* Translators: The %d after 'ISO C' will be 90 or 99.  Do not
1054            separate the %d from the 'C'.  'ISO' should not be
1055            translated, but it may be moved after 'C%d' in languages
1056            where modifiers follow nouns.  */
1057         pedwarn (input_location, OPT_Woverlength_strings,
1058                  "string length %qd is greater than the length %qd "
1059                  "ISO C%d compilers are required to support",
1060                  nchars - 1, nchars_max, relevant_std);
1061     }
1062
1063   /* Create the array type for the string constant.  The ISO C++
1064      standard says that a string literal has type `const char[N]' or
1065      `const wchar_t[N]'.  We use the same logic when invoked as a C
1066      front-end with -Wwrite-strings.
1067      ??? We should change the type of an expression depending on the
1068      state of a warning flag.  We should just be warning -- see how
1069      this is handled in the C++ front-end for the deprecated implicit
1070      conversion from string literals to `char*' or `wchar_t*'.
1071
1072      The C++ front end relies on TYPE_MAIN_VARIANT of a cv-qualified
1073      array type being the unqualified version of that type.
1074      Therefore, if we are constructing an array of const char, we must
1075      construct the matching unqualified array type first.  The C front
1076      end does not require this, but it does no harm, so we do it
1077      unconditionally.  */
1078   i_type = build_index_type (build_int_cst (NULL_TREE, nchars - 1));
1079   a_type = build_array_type (e_type, i_type);
1080   if (c_dialect_cxx() || warn_write_strings)
1081     a_type = c_build_qualified_type (a_type, TYPE_QUAL_CONST);
1082
1083   TREE_TYPE (value) = a_type;
1084   TREE_CONSTANT (value) = 1;
1085   TREE_READONLY (value) = 1;
1086   TREE_STATIC (value) = 1;
1087   return value;
1088 }
1089 \f
1090 /* Fully fold EXPR, an expression that was not folded (beyond integer
1091    constant expressions and null pointer constants) when being built
1092    up.  If IN_INIT, this is in a static initializer and certain
1093    changes are made to the folding done.  Clear *MAYBE_CONST if
1094    MAYBE_CONST is not NULL and EXPR is definitely not a constant
1095    expression because it contains an evaluated operator (in C99) or an
1096    operator outside of sizeof returning an integer constant (in C90)
1097    not permitted in constant expressions, or because it contains an
1098    evaluated arithmetic overflow.  (*MAYBE_CONST should typically be
1099    set to true by callers before calling this function.)  Return the
1100    folded expression.  Function arguments have already been folded
1101    before calling this function, as have the contents of SAVE_EXPR,
1102    TARGET_EXPR, BIND_EXPR, VA_ARG_EXPR, OBJ_TYPE_REF and
1103    C_MAYBE_CONST_EXPR.  */
1104
1105 tree
1106 c_fully_fold (tree expr, bool in_init, bool *maybe_const)
1107 {
1108   tree ret;
1109   tree eptype = NULL_TREE;
1110   bool dummy = true;
1111   bool maybe_const_itself = true;
1112   location_t loc = EXPR_LOCATION (expr);
1113
1114   /* This function is not relevant to C++ because C++ folds while
1115      parsing, and may need changes to be correct for C++ when C++
1116      stops folding while parsing.  */
1117   if (c_dialect_cxx ())
1118     gcc_unreachable ();
1119
1120   if (!maybe_const)
1121     maybe_const = &dummy;
1122   if (TREE_CODE (expr) == EXCESS_PRECISION_EXPR)
1123     {
1124       eptype = TREE_TYPE (expr);
1125       expr = TREE_OPERAND (expr, 0);
1126     }
1127   ret = c_fully_fold_internal (expr, in_init, maybe_const,
1128                                &maybe_const_itself);
1129   if (eptype)
1130     ret = fold_convert_loc (loc, eptype, ret);
1131   *maybe_const &= maybe_const_itself;
1132   return ret;
1133 }
1134
1135 /* Internal helper for c_fully_fold.  EXPR and IN_INIT are as for
1136    c_fully_fold.  *MAYBE_CONST_OPERANDS is cleared because of operands
1137    not permitted, while *MAYBE_CONST_ITSELF is cleared because of
1138    arithmetic overflow (for C90, *MAYBE_CONST_OPERANDS is carried from
1139    both evaluated and unevaluated subexpressions while
1140    *MAYBE_CONST_ITSELF is carried from only evaluated
1141    subexpressions).  */
1142
1143 static tree
1144 c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands,
1145                        bool *maybe_const_itself)
1146 {
1147   tree ret = expr;
1148   enum tree_code code = TREE_CODE (expr);
1149   enum tree_code_class kind = TREE_CODE_CLASS (code);
1150   location_t loc = EXPR_LOCATION (expr);
1151   tree op0, op1, op2, op3;
1152   tree orig_op0, orig_op1, orig_op2;
1153   bool op0_const = true, op1_const = true, op2_const = true;
1154   bool op0_const_self = true, op1_const_self = true, op2_const_self = true;
1155   bool nowarning = TREE_NO_WARNING (expr);
1156   int unused_p;
1157
1158   /* This function is not relevant to C++ because C++ folds while
1159      parsing, and may need changes to be correct for C++ when C++
1160      stops folding while parsing.  */
1161   if (c_dialect_cxx ())
1162     gcc_unreachable ();
1163
1164   /* Constants, declarations, statements, errors, SAVE_EXPRs and
1165      anything else not counted as an expression cannot usefully be
1166      folded further at this point.  */
1167   if (!IS_EXPR_CODE_CLASS (kind)
1168       || kind == tcc_statement
1169       || code == SAVE_EXPR)
1170     return expr;
1171
1172   /* Operands of variable-length expressions (function calls) have
1173      already been folded, as have __builtin_* function calls, and such
1174      expressions cannot occur in constant expressions.  */
1175   if (kind == tcc_vl_exp)
1176     {
1177       *maybe_const_operands = false;
1178       ret = fold (expr);
1179       goto out;
1180     }
1181
1182   if (code == C_MAYBE_CONST_EXPR)
1183     {
1184       tree pre = C_MAYBE_CONST_EXPR_PRE (expr);
1185       tree inner = C_MAYBE_CONST_EXPR_EXPR (expr);
1186       if (C_MAYBE_CONST_EXPR_NON_CONST (expr))
1187         *maybe_const_operands = false;
1188       if (C_MAYBE_CONST_EXPR_INT_OPERANDS (expr))
1189         *maybe_const_itself = false;
1190       if (pre && !in_init)
1191         ret = build2 (COMPOUND_EXPR, TREE_TYPE (expr), pre, inner);
1192       else
1193         ret = inner;
1194       goto out;
1195     }
1196
1197   /* Assignment, increment, decrement, function call and comma
1198      operators, and statement expressions, cannot occur in constant
1199      expressions if evaluated / outside of sizeof.  (Function calls
1200      were handled above, though VA_ARG_EXPR is treated like a function
1201      call here, and statement expressions are handled through
1202      C_MAYBE_CONST_EXPR to avoid folding inside them.)  */
1203   switch (code)
1204     {
1205     case MODIFY_EXPR:
1206     case PREDECREMENT_EXPR:
1207     case PREINCREMENT_EXPR:
1208     case POSTDECREMENT_EXPR:
1209     case POSTINCREMENT_EXPR:
1210     case COMPOUND_EXPR:
1211       *maybe_const_operands = false;
1212       break;
1213
1214     case VA_ARG_EXPR:
1215     case TARGET_EXPR:
1216     case BIND_EXPR:
1217     case OBJ_TYPE_REF:
1218       *maybe_const_operands = false;
1219       ret = fold (expr);
1220       goto out;
1221
1222     default:
1223       break;
1224     }
1225
1226   /* Fold individual tree codes as appropriate.  */
1227   switch (code)
1228     {
1229     case COMPOUND_LITERAL_EXPR:
1230       /* Any non-constancy will have been marked in a containing
1231          C_MAYBE_CONST_EXPR; there is no more folding to do here.  */
1232       goto out;
1233
1234     case COMPONENT_REF:
1235       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1236       op1 = TREE_OPERAND (expr, 1);
1237       op2 = TREE_OPERAND (expr, 2);
1238       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1239                                    maybe_const_itself);
1240       STRIP_TYPE_NOPS (op0);
1241       if (op0 != orig_op0)
1242         ret = build3 (COMPONENT_REF, TREE_TYPE (expr), op0, op1, op2);
1243       if (ret != expr)
1244         {
1245           TREE_READONLY (ret) = TREE_READONLY (expr);
1246           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1247         }
1248       goto out;
1249
1250     case ARRAY_REF:
1251       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1252       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1253       op2 = TREE_OPERAND (expr, 2);
1254       op3 = TREE_OPERAND (expr, 3);
1255       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1256                                    maybe_const_itself);
1257       STRIP_TYPE_NOPS (op0);
1258       op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
1259                                    maybe_const_itself);
1260       STRIP_TYPE_NOPS (op1);
1261       op1 = decl_constant_value_for_optimization (op1);
1262       if (op0 != orig_op0 || op1 != orig_op1)
1263         ret = build4 (ARRAY_REF, TREE_TYPE (expr), op0, op1, op2, op3);
1264       if (ret != expr)
1265         {
1266           TREE_READONLY (ret) = TREE_READONLY (expr);
1267           TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (expr);
1268           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1269         }
1270       ret = fold (ret);
1271       goto out;
1272
1273     case COMPOUND_EXPR:
1274     case MODIFY_EXPR:
1275     case PREDECREMENT_EXPR:
1276     case PREINCREMENT_EXPR:
1277     case POSTDECREMENT_EXPR:
1278     case POSTINCREMENT_EXPR:
1279     case PLUS_EXPR:
1280     case MINUS_EXPR:
1281     case MULT_EXPR:
1282     case POINTER_PLUS_EXPR:
1283     case TRUNC_DIV_EXPR:
1284     case CEIL_DIV_EXPR:
1285     case FLOOR_DIV_EXPR:
1286     case TRUNC_MOD_EXPR:
1287     case RDIV_EXPR:
1288     case EXACT_DIV_EXPR:
1289     case LSHIFT_EXPR:
1290     case RSHIFT_EXPR:
1291     case BIT_IOR_EXPR:
1292     case BIT_XOR_EXPR:
1293     case BIT_AND_EXPR:
1294     case LT_EXPR:
1295     case LE_EXPR:
1296     case GT_EXPR:
1297     case GE_EXPR:
1298     case EQ_EXPR:
1299     case NE_EXPR:
1300     case COMPLEX_EXPR:
1301     case TRUTH_AND_EXPR:
1302     case TRUTH_OR_EXPR:
1303     case TRUTH_XOR_EXPR:
1304     case UNORDERED_EXPR:
1305     case ORDERED_EXPR:
1306     case UNLT_EXPR:
1307     case UNLE_EXPR:
1308     case UNGT_EXPR:
1309     case UNGE_EXPR:
1310     case UNEQ_EXPR:
1311       /* Binary operations evaluating both arguments (increment and
1312          decrement are binary internally in GCC).  */
1313       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1314       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1315       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1316                                    maybe_const_itself);
1317       STRIP_TYPE_NOPS (op0);
1318       if (code != MODIFY_EXPR
1319           && code != PREDECREMENT_EXPR
1320           && code != PREINCREMENT_EXPR
1321           && code != POSTDECREMENT_EXPR
1322           && code != POSTINCREMENT_EXPR)
1323         op0 = decl_constant_value_for_optimization (op0);
1324       /* The RHS of a MODIFY_EXPR was fully folded when building that
1325          expression for the sake of conversion warnings.  */
1326       if (code != MODIFY_EXPR)
1327         op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
1328                                      maybe_const_itself);
1329       STRIP_TYPE_NOPS (op1);
1330       op1 = decl_constant_value_for_optimization (op1);
1331       if (op0 != orig_op0 || op1 != orig_op1 || in_init)
1332         ret = in_init
1333           ? fold_build2_initializer_loc (loc, code, TREE_TYPE (expr), op0, op1)
1334           : fold_build2_loc (loc, code, TREE_TYPE (expr), op0, op1);
1335       else
1336         ret = fold (expr);
1337       if (TREE_OVERFLOW_P (ret)
1338           && !TREE_OVERFLOW_P (op0)
1339           && !TREE_OVERFLOW_P (op1))
1340         overflow_warning (EXPR_LOCATION (expr), ret);
1341       goto out;
1342
1343     case INDIRECT_REF:
1344     case FIX_TRUNC_EXPR:
1345     case FLOAT_EXPR:
1346     CASE_CONVERT:
1347     case NON_LVALUE_EXPR:
1348     case NEGATE_EXPR:
1349     case BIT_NOT_EXPR:
1350     case TRUTH_NOT_EXPR:
1351     case ADDR_EXPR:
1352     case CONJ_EXPR:
1353     case REALPART_EXPR:
1354     case IMAGPART_EXPR:
1355       /* Unary operations.  */
1356       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1357       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
1358                                    maybe_const_itself);
1359       STRIP_TYPE_NOPS (op0);
1360       if (code != ADDR_EXPR && code != REALPART_EXPR && code != IMAGPART_EXPR)
1361         op0 = decl_constant_value_for_optimization (op0);
1362       if (op0 != orig_op0 || in_init)
1363         ret = in_init
1364           ? fold_build1_initializer_loc (loc, code, TREE_TYPE (expr), op0)
1365           : fold_build1_loc (loc, code, TREE_TYPE (expr), op0);
1366       else
1367         ret = fold (expr);
1368       if (code == INDIRECT_REF
1369           && ret != expr
1370           && TREE_CODE (ret) == INDIRECT_REF)
1371         {
1372           TREE_READONLY (ret) = TREE_READONLY (expr);
1373           TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (expr);
1374           TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
1375         }
1376       switch (code)
1377         {
1378         case FIX_TRUNC_EXPR:
1379         case FLOAT_EXPR:
1380         CASE_CONVERT:
1381           /* Don't warn about explicit conversions.  We will already
1382              have warned about suspect implicit conversions.  */
1383           break;
1384
1385         default:
1386           if (TREE_OVERFLOW_P (ret) && !TREE_OVERFLOW_P (op0))
1387             overflow_warning (EXPR_LOCATION (expr), ret);
1388           break;
1389         }
1390       goto out;
1391
1392     case TRUTH_ANDIF_EXPR:
1393     case TRUTH_ORIF_EXPR:
1394       /* Binary operations not necessarily evaluating both
1395          arguments.  */
1396       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1397       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1398       op0 = c_fully_fold_internal (op0, in_init, &op0_const, &op0_const_self);
1399       STRIP_TYPE_NOPS (op0);
1400
1401       unused_p = (op0 == (code == TRUTH_ANDIF_EXPR
1402                           ? truthvalue_false_node
1403                           : truthvalue_true_node));
1404       c_inhibit_evaluation_warnings += unused_p;
1405       op1 = c_fully_fold_internal (op1, in_init, &op1_const, &op1_const_self);
1406       STRIP_TYPE_NOPS (op1);
1407       c_inhibit_evaluation_warnings -= unused_p;
1408
1409       if (op0 != orig_op0 || op1 != orig_op1 || in_init)
1410         ret = in_init
1411           ? fold_build2_initializer_loc (loc, code, TREE_TYPE (expr), op0, op1)
1412           : fold_build2_loc (loc, code, TREE_TYPE (expr), op0, op1);
1413       else
1414         ret = fold (expr);
1415       *maybe_const_operands &= op0_const;
1416       *maybe_const_itself &= op0_const_self;
1417       if (!(flag_isoc99
1418             && op0_const
1419             && op0_const_self
1420             && (code == TRUTH_ANDIF_EXPR
1421                 ? op0 == truthvalue_false_node
1422                 : op0 == truthvalue_true_node)))
1423         *maybe_const_operands &= op1_const;
1424       if (!(op0_const
1425             && op0_const_self
1426             && (code == TRUTH_ANDIF_EXPR
1427                 ? op0 == truthvalue_false_node
1428                 : op0 == truthvalue_true_node)))
1429         *maybe_const_itself &= op1_const_self;
1430       goto out;
1431
1432     case COND_EXPR:
1433       orig_op0 = op0 = TREE_OPERAND (expr, 0);
1434       orig_op1 = op1 = TREE_OPERAND (expr, 1);
1435       orig_op2 = op2 = TREE_OPERAND (expr, 2);
1436       op0 = c_fully_fold_internal (op0, in_init, &op0_const, &op0_const_self);
1437
1438       STRIP_TYPE_NOPS (op0);
1439       c_inhibit_evaluation_warnings += (op0 == truthvalue_false_node);
1440       op1 = c_fully_fold_internal (op1, in_init, &op1_const, &op1_const_self);
1441       STRIP_TYPE_NOPS (op1);
1442       c_inhibit_evaluation_warnings -= (op0 == truthvalue_false_node);
1443
1444       c_inhibit_evaluation_warnings += (op0 == truthvalue_true_node);
1445       op2 = c_fully_fold_internal (op2, in_init, &op2_const, &op2_const_self);
1446       STRIP_TYPE_NOPS (op2);
1447       c_inhibit_evaluation_warnings -= (op0 == truthvalue_true_node);
1448
1449       if (op0 != orig_op0 || op1 != orig_op1 || op2 != orig_op2)
1450         ret = fold_build3_loc (loc, code, TREE_TYPE (expr), op0, op1, op2);
1451       else
1452         ret = fold (expr);
1453       *maybe_const_operands &= op0_const;
1454       *maybe_const_itself &= op0_const_self;
1455       if (!(flag_isoc99
1456             && op0_const
1457             && op0_const_self
1458             && op0 == truthvalue_false_node))
1459         *maybe_const_operands &= op1_const;
1460       if (!(op0_const
1461             && op0_const_self
1462             && op0 == truthvalue_false_node))
1463         *maybe_const_itself &= op1_const_self;
1464       if (!(flag_isoc99
1465             && op0_const
1466             && op0_const_self
1467             && op0 == truthvalue_true_node))
1468         *maybe_const_operands &= op2_const;
1469       if (!(op0_const
1470             && op0_const_self
1471             && op0 == truthvalue_true_node))
1472         *maybe_const_itself &= op2_const_self;
1473       goto out;
1474
1475     case EXCESS_PRECISION_EXPR:
1476       /* Each case where an operand with excess precision may be
1477          encountered must remove the EXCESS_PRECISION_EXPR around
1478          inner operands and possibly put one around the whole
1479          expression or possibly convert to the semantic type (which
1480          c_fully_fold does); we cannot tell at this stage which is
1481          appropriate in any particular case.  */
1482       gcc_unreachable ();
1483
1484     default:
1485       /* Various codes may appear through folding built-in functions
1486          and their arguments.  */
1487       goto out;
1488     }
1489
1490  out:
1491   /* Some folding may introduce NON_LVALUE_EXPRs; all lvalue checks
1492      have been done by this point, so remove them again.  */
1493   nowarning |= TREE_NO_WARNING (ret);
1494   STRIP_TYPE_NOPS (ret);
1495   if (nowarning && !TREE_NO_WARNING (ret))
1496     {
1497       if (!CAN_HAVE_LOCATION_P (ret))
1498         ret = build1 (NOP_EXPR, TREE_TYPE (ret), ret);
1499       TREE_NO_WARNING (ret) = 1;
1500     }
1501   if (ret != expr)
1502     protected_set_expr_location (ret, loc);
1503   return ret;
1504 }
1505
1506 /* If not optimizing, EXP is not a VAR_DECL, or EXP has array type,
1507    return EXP.  Otherwise, return either EXP or its known constant
1508    value (if it has one), but return EXP if EXP has mode BLKmode.  ???
1509    Is the BLKmode test appropriate?  */
1510
1511 tree
1512 decl_constant_value_for_optimization (tree exp)
1513 {
1514   tree ret;
1515
1516   /* This function is only used by C, for c_fully_fold and other
1517      optimization, and may not be correct for C++.  */
1518   if (c_dialect_cxx ())
1519     gcc_unreachable ();
1520
1521   if (!optimize
1522       || TREE_CODE (exp) != VAR_DECL
1523       || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
1524       || DECL_MODE (exp) == BLKmode)
1525     return exp;
1526
1527   ret = decl_constant_value (exp);
1528   /* Avoid unwanted tree sharing between the initializer and current
1529      function's body where the tree can be modified e.g. by the
1530      gimplifier.  */
1531   if (ret != exp && TREE_STATIC (exp))
1532     ret = unshare_expr (ret);
1533   return ret;
1534 }
1535
1536 /* Print a warning if a constant expression had overflow in folding.
1537    Invoke this function on every expression that the language
1538    requires to be a constant expression.
1539    Note the ANSI C standard says it is erroneous for a
1540    constant expression to overflow.  */
1541
1542 void
1543 constant_expression_warning (tree value)
1544 {
1545   if (warn_overflow && pedantic
1546       && (TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
1547           || TREE_CODE (value) == FIXED_CST
1548           || TREE_CODE (value) == VECTOR_CST
1549           || TREE_CODE (value) == COMPLEX_CST)
1550       && TREE_OVERFLOW (value))
1551     pedwarn (input_location, OPT_Woverflow, "overflow in constant expression");
1552 }
1553
1554 /* The same as above but print an unconditional error.  */
1555 void
1556 constant_expression_error (tree value)
1557 {
1558   if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
1559        || TREE_CODE (value) == FIXED_CST
1560        || TREE_CODE (value) == VECTOR_CST
1561        || TREE_CODE (value) == COMPLEX_CST)
1562       && TREE_OVERFLOW (value))
1563     error ("overflow in constant expression");
1564 }
1565
1566 /* Print a warning if an expression had overflow in folding and its
1567    operands hadn't.
1568
1569    Invoke this function on every expression that
1570    (1) appears in the source code, and
1571    (2) is a constant expression that overflowed, and
1572    (3) is not already checked by convert_and_check;
1573    however, do not invoke this function on operands of explicit casts
1574    or when the expression is the result of an operator and any operand
1575    already overflowed.  */
1576
1577 void
1578 overflow_warning (location_t loc, tree value)
1579 {
1580   if (c_inhibit_evaluation_warnings != 0)
1581     return;
1582
1583   switch (TREE_CODE (value))
1584     {
1585     case INTEGER_CST:
1586       warning_at (loc, OPT_Woverflow, "integer overflow in expression");
1587       break;
1588
1589     case REAL_CST:
1590       warning_at (loc, OPT_Woverflow,
1591                   "floating point overflow in expression");
1592       break;
1593
1594     case FIXED_CST:
1595       warning_at (loc, OPT_Woverflow, "fixed-point overflow in expression");
1596       break;
1597
1598     case VECTOR_CST:
1599       warning_at (loc, OPT_Woverflow, "vector overflow in expression");
1600       break;
1601
1602     case COMPLEX_CST:
1603       if (TREE_CODE (TREE_REALPART (value)) == INTEGER_CST)
1604         warning_at (loc, OPT_Woverflow,
1605                     "complex integer overflow in expression");
1606       else if (TREE_CODE (TREE_REALPART (value)) == REAL_CST)
1607         warning_at (loc, OPT_Woverflow,
1608                     "complex floating point overflow in expression");
1609       break;
1610
1611     default:
1612       break;
1613     }
1614 }
1615
1616 /* Warn about uses of logical || / && operator in a context where it
1617    is likely that the bitwise equivalent was intended by the
1618    programmer.  We have seen an expression in which CODE is a binary
1619    operator used to combine expressions OP_LEFT and OP_RIGHT, which before folding
1620    had CODE_LEFT and CODE_RIGHT, into an expression of type TYPE.  */
1621 void
1622 warn_logical_operator (location_t location, enum tree_code code, tree type,
1623                        enum tree_code code_left, tree op_left,
1624                        enum tree_code ARG_UNUSED (code_right), tree op_right)
1625 {
1626   int or_op = (code == TRUTH_ORIF_EXPR || code == TRUTH_OR_EXPR);
1627   int in0_p, in1_p, in_p;
1628   tree low0, low1, low, high0, high1, high, lhs, rhs, tem;
1629   bool strict_overflow_p = false;
1630
1631   if (code != TRUTH_ANDIF_EXPR
1632       && code != TRUTH_AND_EXPR
1633       && code != TRUTH_ORIF_EXPR
1634       && code != TRUTH_OR_EXPR)
1635     return;
1636
1637   /* Warn if &&/|| are being used in a context where it is
1638      likely that the bitwise equivalent was intended by the
1639      programmer. That is, an expression such as op && MASK
1640      where op should not be any boolean expression, nor a
1641      constant, and mask seems to be a non-boolean integer constant.  */
1642   if (!truth_value_p (code_left)
1643       && INTEGRAL_TYPE_P (TREE_TYPE (op_left))
1644       && !CONSTANT_CLASS_P (op_left)
1645       && !TREE_NO_WARNING (op_left)
1646       && TREE_CODE (op_right) == INTEGER_CST
1647       && !integer_zerop (op_right)
1648       && !integer_onep (op_right))
1649     {
1650       if (or_op)
1651         warning_at (location, OPT_Wlogical_op, "logical %<or%>"
1652                     " applied to non-boolean constant");
1653       else
1654         warning_at (location, OPT_Wlogical_op, "logical %<and%>"
1655                     " applied to non-boolean constant");
1656       TREE_NO_WARNING (op_left) = true;
1657       return;
1658     }
1659
1660   /* We do not warn for constants because they are typical of macro
1661      expansions that test for features.  */
1662   if (CONSTANT_CLASS_P (op_left) || CONSTANT_CLASS_P (op_right))
1663     return;
1664
1665   /* This warning only makes sense with logical operands.  */
1666   if (!(truth_value_p (TREE_CODE (op_left))
1667         || INTEGRAL_TYPE_P (TREE_TYPE (op_left)))
1668       || !(truth_value_p (TREE_CODE (op_right))
1669            || INTEGRAL_TYPE_P (TREE_TYPE (op_right))))
1670     return;
1671
1672   lhs = make_range (op_left, &in0_p, &low0, &high0, &strict_overflow_p);
1673   rhs = make_range (op_right, &in1_p, &low1, &high1, &strict_overflow_p);
1674
1675   if (lhs && TREE_CODE (lhs) == C_MAYBE_CONST_EXPR)
1676     lhs = C_MAYBE_CONST_EXPR_EXPR (lhs);
1677
1678   if (rhs && TREE_CODE (rhs) == C_MAYBE_CONST_EXPR)
1679     rhs = C_MAYBE_CONST_EXPR_EXPR (rhs);
1680
1681   /* If this is an OR operation, invert both sides; we will invert
1682      again at the end.  */
1683   if (or_op)
1684     in0_p = !in0_p, in1_p = !in1_p;
1685
1686   /* If both expressions are the same, if we can merge the ranges, and we
1687      can build the range test, return it or it inverted.  */
1688   if (lhs && rhs && operand_equal_p (lhs, rhs, 0)
1689       && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
1690                        in1_p, low1, high1)
1691       && 0 != (tem = build_range_check (UNKNOWN_LOCATION,
1692                                         type, lhs, in_p, low, high)))
1693     {
1694       if (TREE_CODE (tem) != INTEGER_CST)
1695         return;
1696
1697       if (or_op)
1698         warning_at (location, OPT_Wlogical_op,
1699                     "logical %<or%> "
1700                     "of collectively exhaustive tests is always true");
1701       else
1702         warning_at (location, OPT_Wlogical_op,
1703                     "logical %<and%> "
1704                     "of mutually exclusive tests is always false");
1705     }
1706 }
1707
1708
1709 /* Print a warning about casts that might indicate violation
1710    of strict aliasing rules if -Wstrict-aliasing is used and
1711    strict aliasing mode is in effect. OTYPE is the original
1712    TREE_TYPE of EXPR, and TYPE the type we're casting to. */
1713
1714 bool
1715 strict_aliasing_warning (tree otype, tree type, tree expr)
1716 {
1717   /* Strip pointer conversion chains and get to the correct original type.  */
1718   STRIP_NOPS (expr);
1719   otype = TREE_TYPE (expr);
1720
1721   if (!(flag_strict_aliasing
1722         && POINTER_TYPE_P (type)
1723         && POINTER_TYPE_P (otype)
1724         && !VOID_TYPE_P (TREE_TYPE (type)))
1725       /* If the type we are casting to is a ref-all pointer
1726          dereferencing it is always valid.  */
1727       || TYPE_REF_CAN_ALIAS_ALL (type))
1728     return false;
1729
1730   if ((warn_strict_aliasing > 1) && TREE_CODE (expr) == ADDR_EXPR
1731       && (DECL_P (TREE_OPERAND (expr, 0))
1732           || handled_component_p (TREE_OPERAND (expr, 0))))
1733     {
1734       /* Casting the address of an object to non void pointer. Warn
1735          if the cast breaks type based aliasing.  */
1736       if (!COMPLETE_TYPE_P (TREE_TYPE (type)) && warn_strict_aliasing == 2)
1737         {
1738           warning (OPT_Wstrict_aliasing, "type-punning to incomplete type "
1739                    "might break strict-aliasing rules");
1740           return true;
1741         }
1742       else
1743         {
1744           /* warn_strict_aliasing >= 3.   This includes the default (3).
1745              Only warn if the cast is dereferenced immediately.  */
1746           alias_set_type set1 =
1747             get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0)));
1748           alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1749
1750           if (set1 != set2 && set2 != 0
1751               && (set1 == 0 || !alias_sets_conflict_p (set1, set2)))
1752             {
1753               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1754                        "pointer will break strict-aliasing rules");
1755               return true;
1756             }
1757           else if (warn_strict_aliasing == 2
1758                    && !alias_sets_must_conflict_p (set1, set2))
1759             {
1760               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1761                        "pointer might break strict-aliasing rules");
1762               return true;
1763             }
1764         }
1765     }
1766   else
1767     if ((warn_strict_aliasing == 1) && !VOID_TYPE_P (TREE_TYPE (otype)))
1768       {
1769         /* At this level, warn for any conversions, even if an address is
1770            not taken in the same statement.  This will likely produce many
1771            false positives, but could be useful to pinpoint problems that
1772            are not revealed at higher levels.  */
1773         alias_set_type set1 = get_alias_set (TREE_TYPE (otype));
1774         alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1775         if (!COMPLETE_TYPE_P (type)
1776             || !alias_sets_must_conflict_p (set1, set2))
1777           {
1778             warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1779                      "pointer might break strict-aliasing rules");
1780             return true;
1781           }
1782       }
1783
1784   return false;
1785 }
1786
1787 /* Warn for unlikely, improbable, or stupid DECL declarations
1788    of `main'.  */
1789
1790 void
1791 check_main_parameter_types (tree decl)
1792 {
1793   tree args;
1794   int argct = 0;
1795
1796   for (args = TYPE_ARG_TYPES (TREE_TYPE (decl)); args;
1797       args = TREE_CHAIN (args))
1798    {
1799      tree type = args ? TREE_VALUE (args) : 0;
1800
1801      if (type == void_type_node || type == error_mark_node )
1802        break;
1803
1804      ++argct;
1805      switch (argct)
1806        {
1807        case 1:
1808          if (TYPE_MAIN_VARIANT (type) != integer_type_node)
1809            pedwarn (input_location, OPT_Wmain, "first argument of %q+D should be %<int%>",
1810                     decl);
1811          break;
1812
1813        case 2:
1814          if (TREE_CODE (type) != POINTER_TYPE
1815              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1816              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1817                  != char_type_node))
1818            pedwarn (input_location, OPT_Wmain, "second argument of %q+D should be %<char **%>",
1819                     decl);
1820          break;
1821
1822        case 3:
1823          if (TREE_CODE (type) != POINTER_TYPE
1824              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1825              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1826                  != char_type_node))
1827            pedwarn (input_location, OPT_Wmain, "third argument of %q+D should probably be "
1828                     "%<char **%>", decl);
1829          break;
1830        }
1831    }
1832
1833   /* It is intentional that this message does not mention the third
1834     argument because it's only mentioned in an appendix of the
1835     standard.  */
1836   if (argct > 0 && (argct < 2 || argct > 3))
1837     pedwarn (input_location, OPT_Wmain, "%q+D takes only zero or two arguments", decl);
1838 }
1839
1840 /* True if pointers to distinct types T1 and T2 can be converted to
1841    each other without an explicit cast.  Only returns true for opaque
1842    vector types.  */
1843 bool
1844 vector_targets_convertible_p (const_tree t1, const_tree t2)
1845 {
1846   if (TREE_CODE (t1) == VECTOR_TYPE && TREE_CODE (t2) == VECTOR_TYPE
1847       && (TYPE_VECTOR_OPAQUE (t1) || TYPE_VECTOR_OPAQUE (t2))
1848       && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)))
1849     return true;
1850
1851   return false;
1852 }
1853
1854 /* True if vector types T1 and T2 can be converted to each other
1855    without an explicit cast.  If EMIT_LAX_NOTE is true, and T1 and T2
1856    can only be converted with -flax-vector-conversions yet that is not
1857    in effect, emit a note telling the user about that option if such
1858    a note has not previously been emitted.  */
1859 bool
1860 vector_types_convertible_p (const_tree t1, const_tree t2, bool emit_lax_note)
1861 {
1862   static bool emitted_lax_note = false;
1863   bool convertible_lax;
1864
1865   if ((TYPE_VECTOR_OPAQUE (t1) || TYPE_VECTOR_OPAQUE (t2))
1866       && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)))
1867     return true;
1868
1869   convertible_lax =
1870     (tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2))
1871      && (TREE_CODE (TREE_TYPE (t1)) != REAL_TYPE ||
1872          TYPE_PRECISION (t1) == TYPE_PRECISION (t2))
1873      && (INTEGRAL_TYPE_P (TREE_TYPE (t1))
1874          == INTEGRAL_TYPE_P (TREE_TYPE (t2))));
1875
1876   if (!convertible_lax || flag_lax_vector_conversions)
1877     return convertible_lax;
1878
1879   if (TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1880       && lang_hooks.types_compatible_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1881     return true;
1882
1883   if (emit_lax_note && !emitted_lax_note)
1884     {
1885       emitted_lax_note = true;
1886       inform (input_location, "use -flax-vector-conversions to permit "
1887               "conversions between vectors with differing "
1888               "element types or numbers of subparts");
1889     }
1890
1891   return false;
1892 }
1893
1894 /* This is a helper function of build_binary_op.
1895
1896    For certain operations if both args were extended from the same
1897    smaller type, do the arithmetic in that type and then extend.
1898
1899    BITWISE indicates a bitwise operation.
1900    For them, this optimization is safe only if
1901    both args are zero-extended or both are sign-extended.
1902    Otherwise, we might change the result.
1903    Eg, (short)-1 | (unsigned short)-1 is (int)-1
1904    but calculated in (unsigned short) it would be (unsigned short)-1.
1905 */
1906 tree shorten_binary_op (tree result_type, tree op0, tree op1, bool bitwise)
1907 {
1908   int unsigned0, unsigned1;
1909   tree arg0, arg1;
1910   int uns;
1911   tree type;
1912
1913   /* Cast OP0 and OP1 to RESULT_TYPE.  Doing so prevents
1914      excessive narrowing when we call get_narrower below.  For
1915      example, suppose that OP0 is of unsigned int extended
1916      from signed char and that RESULT_TYPE is long long int.
1917      If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
1918      like
1919
1920      (long long int) (unsigned int) signed_char
1921
1922      which get_narrower would narrow down to
1923
1924      (unsigned int) signed char
1925
1926      If we do not cast OP0 first, get_narrower would return
1927      signed_char, which is inconsistent with the case of the
1928      explicit cast.  */
1929   op0 = convert (result_type, op0);
1930   op1 = convert (result_type, op1);
1931
1932   arg0 = get_narrower (op0, &unsigned0);
1933   arg1 = get_narrower (op1, &unsigned1);
1934
1935   /* UNS is 1 if the operation to be done is an unsigned one.  */
1936   uns = TYPE_UNSIGNED (result_type);
1937
1938   /* Handle the case that OP0 (or OP1) does not *contain* a conversion
1939      but it *requires* conversion to FINAL_TYPE.  */
1940
1941   if ((TYPE_PRECISION (TREE_TYPE (op0))
1942        == TYPE_PRECISION (TREE_TYPE (arg0)))
1943       && TREE_TYPE (op0) != result_type)
1944     unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
1945   if ((TYPE_PRECISION (TREE_TYPE (op1))
1946        == TYPE_PRECISION (TREE_TYPE (arg1)))
1947       && TREE_TYPE (op1) != result_type)
1948     unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
1949
1950   /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE.  */
1951
1952   /* For bitwise operations, signedness of nominal type
1953      does not matter.  Consider only how operands were extended.  */
1954   if (bitwise)
1955     uns = unsigned0;
1956
1957   /* Note that in all three cases below we refrain from optimizing
1958      an unsigned operation on sign-extended args.
1959      That would not be valid.  */
1960
1961   /* Both args variable: if both extended in same way
1962      from same width, do it in that width.
1963      Do it unsigned if args were zero-extended.  */
1964   if ((TYPE_PRECISION (TREE_TYPE (arg0))
1965        < TYPE_PRECISION (result_type))
1966       && (TYPE_PRECISION (TREE_TYPE (arg1))
1967           == TYPE_PRECISION (TREE_TYPE (arg0)))
1968       && unsigned0 == unsigned1
1969       && (unsigned0 || !uns))
1970     return c_common_signed_or_unsigned_type
1971       (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
1972
1973   else if (TREE_CODE (arg0) == INTEGER_CST
1974            && (unsigned1 || !uns)
1975            && (TYPE_PRECISION (TREE_TYPE (arg1))
1976                < TYPE_PRECISION (result_type))
1977            && (type
1978                = c_common_signed_or_unsigned_type (unsigned1,
1979                                                    TREE_TYPE (arg1)))
1980            && !POINTER_TYPE_P (type)
1981            && int_fits_type_p (arg0, type))
1982     return type;
1983
1984   else if (TREE_CODE (arg1) == INTEGER_CST
1985            && (unsigned0 || !uns)
1986            && (TYPE_PRECISION (TREE_TYPE (arg0))
1987                < TYPE_PRECISION (result_type))
1988            && (type
1989                = c_common_signed_or_unsigned_type (unsigned0,
1990                                                    TREE_TYPE (arg0)))
1991            && !POINTER_TYPE_P (type)
1992            && int_fits_type_p (arg1, type))
1993     return type;
1994
1995   return result_type;
1996 }
1997
1998 /* Warns if the conversion of EXPR to TYPE may alter a value.
1999    This is a helper function for warnings_for_convert_and_check.  */
2000
2001 static void
2002 conversion_warning (tree type, tree expr)
2003 {
2004   bool give_warning = false;
2005
2006   int i;
2007   const int expr_num_operands = TREE_OPERAND_LENGTH (expr);
2008   tree expr_type = TREE_TYPE (expr);
2009
2010   if (!warn_conversion && !warn_sign_conversion)
2011     return;
2012
2013   /* If any operand is artificial, then this expression was generated
2014      by the compiler and we do not warn.  */
2015   for (i = 0; i < expr_num_operands; i++)
2016     {
2017       tree op = TREE_OPERAND (expr, i);
2018       if (op && DECL_P (op) && DECL_ARTIFICIAL (op))
2019         return;
2020     }
2021
2022   switch (TREE_CODE (expr))
2023     {
2024     case EQ_EXPR:
2025     case NE_EXPR:
2026     case LE_EXPR:
2027     case GE_EXPR:
2028     case LT_EXPR:
2029     case GT_EXPR:
2030     case TRUTH_ANDIF_EXPR:
2031     case TRUTH_ORIF_EXPR:
2032     case TRUTH_AND_EXPR:
2033     case TRUTH_OR_EXPR:
2034     case TRUTH_XOR_EXPR:
2035     case TRUTH_NOT_EXPR:
2036       /* Conversion from boolean to a signed:1 bit-field (which only
2037          can hold the values 0 and -1) doesn't lose information - but
2038          it does change the value.  */
2039       if (TYPE_PRECISION (type) == 1 && !TYPE_UNSIGNED (type))
2040         warning (OPT_Wconversion,
2041                  "conversion to %qT from boolean expression", type);
2042       return;
2043
2044     case REAL_CST:
2045     case INTEGER_CST:
2046
2047       /* Warn for real constant that is not an exact integer converted
2048          to integer type.  */
2049       if (TREE_CODE (expr_type) == REAL_TYPE
2050           && TREE_CODE (type) == INTEGER_TYPE)
2051         {
2052           if (!real_isinteger (TREE_REAL_CST_PTR (expr), TYPE_MODE (expr_type)))
2053             give_warning = true;
2054         }
2055       /* Warn for an integer constant that does not fit into integer type.  */
2056       else if (TREE_CODE (expr_type) == INTEGER_TYPE
2057                && TREE_CODE (type) == INTEGER_TYPE
2058                && !int_fits_type_p (expr, type))
2059         {
2060           if (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (expr_type)
2061               && tree_int_cst_sgn (expr) < 0)
2062             warning (OPT_Wsign_conversion,
2063                      "negative integer implicitly converted to unsigned type");
2064           else if (!TYPE_UNSIGNED (type) && TYPE_UNSIGNED (expr_type))
2065             warning (OPT_Wsign_conversion,  "conversion of unsigned constant "
2066                      "value to negative integer");
2067           else
2068             give_warning = true;
2069         }
2070       else if (TREE_CODE (type) == REAL_TYPE)
2071         {
2072           /* Warn for an integer constant that does not fit into real type.  */
2073           if (TREE_CODE (expr_type) == INTEGER_TYPE)
2074             {
2075               REAL_VALUE_TYPE a = real_value_from_int_cst (0, expr);
2076               if (!exact_real_truncate (TYPE_MODE (type), &a))
2077                 give_warning = true;
2078             }
2079           /* Warn for a real constant that does not fit into a smaller
2080              real type.  */
2081           else if (TREE_CODE (expr_type) == REAL_TYPE
2082                    && TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2083             {
2084               REAL_VALUE_TYPE a = TREE_REAL_CST (expr);
2085               if (!exact_real_truncate (TYPE_MODE (type), &a))
2086                 give_warning = true;
2087             }
2088         }
2089
2090       if (give_warning)
2091         warning (OPT_Wconversion,
2092                  "conversion to %qT alters %qT constant value",
2093                  type, expr_type);
2094
2095       return;
2096
2097     case COND_EXPR:
2098       {
2099         /* In case of COND_EXPR, if both operands are constants or
2100            COND_EXPR, then we do not care about the type of COND_EXPR,
2101            only about the conversion of each operand.  */
2102         tree op1 = TREE_OPERAND (expr, 1);
2103         tree op2 = TREE_OPERAND (expr, 2);
2104
2105         if ((TREE_CODE (op1) == REAL_CST || TREE_CODE (op1) == INTEGER_CST
2106              || TREE_CODE (op1) == COND_EXPR)
2107             && (TREE_CODE (op2) == REAL_CST || TREE_CODE (op2) == INTEGER_CST
2108                 || TREE_CODE (op2) == COND_EXPR))
2109           {
2110             conversion_warning (type, op1);
2111             conversion_warning (type, op2);
2112             return;
2113           }
2114         /* Fall through.  */
2115       }
2116
2117     default: /* 'expr' is not a constant.  */
2118
2119       /* Warn for real types converted to integer types.  */
2120       if (TREE_CODE (expr_type) == REAL_TYPE
2121           && TREE_CODE (type) == INTEGER_TYPE)
2122         give_warning = true;
2123
2124       else if (TREE_CODE (expr_type) == INTEGER_TYPE
2125                && TREE_CODE (type) == INTEGER_TYPE)
2126         {
2127           /* Don't warn about unsigned char y = 0xff, x = (int) y;  */
2128           expr = get_unwidened (expr, 0);
2129           expr_type = TREE_TYPE (expr);
2130
2131           /* Don't warn for short y; short x = ((int)y & 0xff);  */
2132           if (TREE_CODE (expr) == BIT_AND_EXPR
2133                 || TREE_CODE (expr) == BIT_IOR_EXPR
2134               || TREE_CODE (expr) == BIT_XOR_EXPR)
2135             {
2136               /* If both args were extended from a shortest type,
2137                  use that type if that is safe.  */
2138               expr_type = shorten_binary_op (expr_type,
2139                                              TREE_OPERAND (expr, 0),
2140                                              TREE_OPERAND (expr, 1),
2141                                              /* bitwise */1);
2142
2143               if (TREE_CODE (expr) == BIT_AND_EXPR)
2144                 {
2145                   tree op0 = TREE_OPERAND (expr, 0);
2146                   tree op1 = TREE_OPERAND (expr, 1);
2147                   bool unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
2148                   bool unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
2149
2150                   /* If one of the operands is a non-negative constant
2151                      that fits in the target type, then the type of the
2152                      other operand does not matter. */
2153                   if ((TREE_CODE (op0) == INTEGER_CST
2154                        && int_fits_type_p (op0, c_common_signed_type (type))
2155                        && int_fits_type_p (op0, c_common_unsigned_type (type)))
2156                       || (TREE_CODE (op1) == INTEGER_CST
2157                           && int_fits_type_p (op1, c_common_signed_type (type))
2158                           && int_fits_type_p (op1,
2159                                               c_common_unsigned_type (type))))
2160                     return;
2161                   /* If constant is unsigned and fits in the target
2162                      type, then the result will also fit.  */
2163                   else if ((TREE_CODE (op0) == INTEGER_CST
2164                             && unsigned0
2165                             && int_fits_type_p (op0, type))
2166                            || (TREE_CODE (op1) == INTEGER_CST
2167                                && unsigned1
2168                                && int_fits_type_p (op1, type)))
2169                     return;
2170                 }
2171             }
2172           /* Warn for integer types converted to smaller integer types.  */
2173           if (TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2174             give_warning = true;
2175
2176           /* When they are the same width but different signedness,
2177              then the value may change.  */
2178           else if ((TYPE_PRECISION (type) == TYPE_PRECISION (expr_type)
2179                     && TYPE_UNSIGNED (expr_type) != TYPE_UNSIGNED (type))
2180                    /* Even when converted to a bigger type, if the type is
2181                       unsigned but expr is signed, then negative values
2182                       will be changed.  */
2183                    || (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (expr_type)))
2184             warning (OPT_Wsign_conversion, "conversion to %qT from %qT "
2185                      "may change the sign of the result",
2186                      type, expr_type);
2187         }
2188
2189       /* Warn for integer types converted to real types if and only if
2190          all the range of values of the integer type cannot be
2191          represented by the real type.  */
2192       else if (TREE_CODE (expr_type) == INTEGER_TYPE
2193                && TREE_CODE (type) == REAL_TYPE)
2194         {
2195           tree type_low_bound, type_high_bound;
2196           REAL_VALUE_TYPE real_low_bound, real_high_bound;
2197
2198           /* Don't warn about char y = 0xff; float x = (int) y;  */
2199           expr = get_unwidened (expr, 0);
2200           expr_type = TREE_TYPE (expr);
2201
2202           type_low_bound = TYPE_MIN_VALUE (expr_type);
2203           type_high_bound = TYPE_MAX_VALUE (expr_type);
2204           real_low_bound = real_value_from_int_cst (0, type_low_bound);
2205           real_high_bound = real_value_from_int_cst (0, type_high_bound);
2206
2207           if (!exact_real_truncate (TYPE_MODE (type), &real_low_bound)
2208               || !exact_real_truncate (TYPE_MODE (type), &real_high_bound))
2209             give_warning = true;
2210         }
2211
2212       /* Warn for real types converted to smaller real types.  */
2213       else if (TREE_CODE (expr_type) == REAL_TYPE
2214                && TREE_CODE (type) == REAL_TYPE
2215                && TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
2216         give_warning = true;
2217
2218
2219       if (give_warning)
2220         warning (OPT_Wconversion,
2221                  "conversion to %qT from %qT may alter its value",
2222                  type, expr_type);
2223     }
2224 }
2225
2226 /* Produce warnings after a conversion. RESULT is the result of
2227    converting EXPR to TYPE.  This is a helper function for
2228    convert_and_check and cp_convert_and_check.  */
2229
2230 void
2231 warnings_for_convert_and_check (tree type, tree expr, tree result)
2232 {
2233   if (TREE_CODE (expr) == INTEGER_CST
2234       && (TREE_CODE (type) == INTEGER_TYPE
2235           || TREE_CODE (type) == ENUMERAL_TYPE)
2236       && !int_fits_type_p (expr, type))
2237     {
2238       /* Do not diagnose overflow in a constant expression merely
2239          because a conversion overflowed.  */
2240       if (TREE_OVERFLOW (result))
2241         TREE_OVERFLOW (result) = TREE_OVERFLOW (expr);
2242
2243       if (TYPE_UNSIGNED (type))
2244         {
2245           /* This detects cases like converting -129 or 256 to
2246              unsigned char.  */
2247           if (!int_fits_type_p (expr, c_common_signed_type (type)))
2248             warning (OPT_Woverflow,
2249                      "large integer implicitly truncated to unsigned type");
2250           else
2251             conversion_warning (type, expr);
2252         }
2253       else if (!int_fits_type_p (expr, c_common_unsigned_type (type)))
2254         warning (OPT_Woverflow,
2255                  "overflow in implicit constant conversion");
2256       /* No warning for converting 0x80000000 to int.  */
2257       else if (pedantic
2258                && (TREE_CODE (TREE_TYPE (expr)) != INTEGER_TYPE
2259                    || TYPE_PRECISION (TREE_TYPE (expr))
2260                    != TYPE_PRECISION (type)))
2261         warning (OPT_Woverflow,
2262                  "overflow in implicit constant conversion");
2263
2264       else
2265         conversion_warning (type, expr);
2266     }
2267   else if ((TREE_CODE (result) == INTEGER_CST
2268             || TREE_CODE (result) == FIXED_CST) && TREE_OVERFLOW (result))
2269     warning (OPT_Woverflow,
2270              "overflow in implicit constant conversion");
2271   else
2272     conversion_warning (type, expr);
2273 }
2274
2275
2276 /* Convert EXPR to TYPE, warning about conversion problems with constants.
2277    Invoke this function on every expression that is converted implicitly,
2278    i.e. because of language rules and not because of an explicit cast.  */
2279
2280 tree
2281 convert_and_check (tree type, tree expr)
2282 {
2283   tree result;
2284   tree expr_for_warning;
2285
2286   /* Convert from a value with possible excess precision rather than
2287      via the semantic type, but do not warn about values not fitting
2288      exactly in the semantic type.  */
2289   if (TREE_CODE (expr) == EXCESS_PRECISION_EXPR)
2290     {
2291       tree orig_type = TREE_TYPE (expr);
2292       expr = TREE_OPERAND (expr, 0);
2293       expr_for_warning = convert (orig_type, expr);
2294       if (orig_type == type)
2295         return expr_for_warning;
2296     }
2297   else
2298     expr_for_warning = expr;
2299
2300   if (TREE_TYPE (expr) == type)
2301     return expr;
2302
2303   result = convert (type, expr);
2304
2305   if (c_inhibit_evaluation_warnings == 0
2306       && !TREE_OVERFLOW_P (expr)
2307       && result != error_mark_node)
2308     warnings_for_convert_and_check (type, expr_for_warning, result);
2309
2310   return result;
2311 }
2312 \f
2313 /* A node in a list that describes references to variables (EXPR), which are
2314    either read accesses if WRITER is zero, or write accesses, in which case
2315    WRITER is the parent of EXPR.  */
2316 struct tlist
2317 {
2318   struct tlist *next;
2319   tree expr, writer;
2320 };
2321
2322 /* Used to implement a cache the results of a call to verify_tree.  We only
2323    use this for SAVE_EXPRs.  */
2324 struct tlist_cache
2325 {
2326   struct tlist_cache *next;
2327   struct tlist *cache_before_sp;
2328   struct tlist *cache_after_sp;
2329   tree expr;
2330 };
2331
2332 /* Obstack to use when allocating tlist structures, and corresponding
2333    firstobj.  */
2334 static struct obstack tlist_obstack;
2335 static char *tlist_firstobj = 0;
2336
2337 /* Keep track of the identifiers we've warned about, so we can avoid duplicate
2338    warnings.  */
2339 static struct tlist *warned_ids;
2340 /* SAVE_EXPRs need special treatment.  We process them only once and then
2341    cache the results.  */
2342 static struct tlist_cache *save_expr_cache;
2343
2344 static void add_tlist (struct tlist **, struct tlist *, tree, int);
2345 static void merge_tlist (struct tlist **, struct tlist *, int);
2346 static void verify_tree (tree, struct tlist **, struct tlist **, tree);
2347 static int warning_candidate_p (tree);
2348 static bool candidate_equal_p (const_tree, const_tree);
2349 static void warn_for_collisions (struct tlist *);
2350 static void warn_for_collisions_1 (tree, tree, struct tlist *, int);
2351 static struct tlist *new_tlist (struct tlist *, tree, tree);
2352
2353 /* Create a new struct tlist and fill in its fields.  */
2354 static struct tlist *
2355 new_tlist (struct tlist *next, tree t, tree writer)
2356 {
2357   struct tlist *l;
2358   l = XOBNEW (&tlist_obstack, struct tlist);
2359   l->next = next;
2360   l->expr = t;
2361   l->writer = writer;
2362   return l;
2363 }
2364
2365 /* Add duplicates of the nodes found in ADD to the list *TO.  If EXCLUDE_WRITER
2366    is nonnull, we ignore any node we find which has a writer equal to it.  */
2367
2368 static void
2369 add_tlist (struct tlist **to, struct tlist *add, tree exclude_writer, int copy)
2370 {
2371   while (add)
2372     {
2373       struct tlist *next = add->next;
2374       if (!copy)
2375         add->next = *to;
2376       if (!exclude_writer || !candidate_equal_p (add->writer, exclude_writer))
2377         *to = copy ? new_tlist (*to, add->expr, add->writer) : add;
2378       add = next;
2379     }
2380 }
2381
2382 /* Merge the nodes of ADD into TO.  This merging process is done so that for
2383    each variable that already exists in TO, no new node is added; however if
2384    there is a write access recorded in ADD, and an occurrence on TO is only
2385    a read access, then the occurrence in TO will be modified to record the
2386    write.  */
2387
2388 static void
2389 merge_tlist (struct tlist **to, struct tlist *add, int copy)
2390 {
2391   struct tlist **end = to;
2392
2393   while (*end)
2394     end = &(*end)->next;
2395
2396   while (add)
2397     {
2398       int found = 0;
2399       struct tlist *tmp2;
2400       struct tlist *next = add->next;
2401
2402       for (tmp2 = *to; tmp2; tmp2 = tmp2->next)
2403         if (candidate_equal_p (tmp2->expr, add->expr))
2404           {
2405             found = 1;
2406             if (!tmp2->writer)
2407               tmp2->writer = add->writer;
2408           }
2409       if (!found)
2410         {
2411           *end = copy ? add : new_tlist (NULL, add->expr, add->writer);
2412           end = &(*end)->next;
2413           *end = 0;
2414         }
2415       add = next;
2416     }
2417 }
2418
2419 /* WRITTEN is a variable, WRITER is its parent.  Warn if any of the variable
2420    references in list LIST conflict with it, excluding reads if ONLY writers
2421    is nonzero.  */
2422
2423 static void
2424 warn_for_collisions_1 (tree written, tree writer, struct tlist *list,
2425                        int only_writes)
2426 {
2427   struct tlist *tmp;
2428
2429   /* Avoid duplicate warnings.  */
2430   for (tmp = warned_ids; tmp; tmp = tmp->next)
2431     if (candidate_equal_p (tmp->expr, written))
2432       return;
2433
2434   while (list)
2435     {
2436       if (candidate_equal_p (list->expr, written)
2437           && !candidate_equal_p (list->writer, writer)
2438           && (!only_writes || list->writer))
2439         {
2440           warned_ids = new_tlist (warned_ids, written, NULL_TREE);
2441           warning_at (EXPR_HAS_LOCATION (writer)
2442                       ? EXPR_LOCATION (writer) : input_location,
2443                       OPT_Wsequence_point, "operation on %qE may be undefined",
2444                       list->expr);
2445         }
2446       list = list->next;
2447     }
2448 }
2449
2450 /* Given a list LIST of references to variables, find whether any of these
2451    can cause conflicts due to missing sequence points.  */
2452
2453 static void
2454 warn_for_collisions (struct tlist *list)
2455 {
2456   struct tlist *tmp;
2457
2458   for (tmp = list; tmp; tmp = tmp->next)
2459     {
2460       if (tmp->writer)
2461         warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0);
2462     }
2463 }
2464
2465 /* Return nonzero if X is a tree that can be verified by the sequence point
2466    warnings.  */
2467 static int
2468 warning_candidate_p (tree x)
2469 {
2470   /* !VOID_TYPE_P (TREE_TYPE (x)) is workaround for cp/tree.c
2471      (lvalue_p) crash on TRY/CATCH. */
2472   return !(DECL_P (x) && DECL_ARTIFICIAL (x))
2473     && TREE_TYPE (x) && !VOID_TYPE_P (TREE_TYPE (x)) && lvalue_p (x);
2474 }
2475
2476 /* Return nonzero if X and Y appear to be the same candidate (or NULL) */
2477 static bool
2478 candidate_equal_p (const_tree x, const_tree y)
2479 {
2480   return (x == y) || (x && y && operand_equal_p (x, y, 0));
2481 }
2482
2483 /* Walk the tree X, and record accesses to variables.  If X is written by the
2484    parent tree, WRITER is the parent.
2485    We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP.  If this
2486    expression or its only operand forces a sequence point, then everything up
2487    to the sequence point is stored in PBEFORE_SP.  Everything else gets stored
2488    in PNO_SP.
2489    Once we return, we will have emitted warnings if any subexpression before
2490    such a sequence point could be undefined.  On a higher level, however, the
2491    sequence point may not be relevant, and we'll merge the two lists.
2492
2493    Example: (b++, a) + b;
2494    The call that processes the COMPOUND_EXPR will store the increment of B
2495    in PBEFORE_SP, and the use of A in PNO_SP.  The higher-level call that
2496    processes the PLUS_EXPR will need to merge the two lists so that
2497    eventually, all accesses end up on the same list (and we'll warn about the
2498    unordered subexpressions b++ and b.
2499
2500    A note on merging.  If we modify the former example so that our expression
2501    becomes
2502      (b++, b) + a
2503    care must be taken not simply to add all three expressions into the final
2504    PNO_SP list.  The function merge_tlist takes care of that by merging the
2505    before-SP list of the COMPOUND_EXPR into its after-SP list in a special
2506    way, so that no more than one access to B is recorded.  */
2507
2508 static void
2509 verify_tree (tree x, struct tlist **pbefore_sp, struct tlist **pno_sp,
2510              tree writer)
2511 {
2512   struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3;
2513   enum tree_code code;
2514   enum tree_code_class cl;
2515
2516   /* X may be NULL if it is the operand of an empty statement expression
2517      ({ }).  */
2518   if (x == NULL)
2519     return;
2520
2521  restart:
2522   code = TREE_CODE (x);
2523   cl = TREE_CODE_CLASS (code);
2524
2525   if (warning_candidate_p (x))
2526     *pno_sp = new_tlist (*pno_sp, x, writer);
2527
2528   switch (code)
2529     {
2530     case CONSTRUCTOR:
2531       return;
2532
2533     case COMPOUND_EXPR:
2534     case TRUTH_ANDIF_EXPR:
2535     case TRUTH_ORIF_EXPR:
2536       tmp_before = tmp_nosp = tmp_list3 = 0;
2537       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
2538       warn_for_collisions (tmp_nosp);
2539       merge_tlist (pbefore_sp, tmp_before, 0);
2540       merge_tlist (pbefore_sp, tmp_nosp, 0);
2541       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE);
2542       merge_tlist (pbefore_sp, tmp_list3, 0);
2543       return;
2544
2545     case COND_EXPR:
2546       tmp_before = tmp_list2 = 0;
2547       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE);
2548       warn_for_collisions (tmp_list2);
2549       merge_tlist (pbefore_sp, tmp_before, 0);
2550       merge_tlist (pbefore_sp, tmp_list2, 1);
2551
2552       tmp_list3 = tmp_nosp = 0;
2553       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE);
2554       warn_for_collisions (tmp_nosp);
2555       merge_tlist (pbefore_sp, tmp_list3, 0);
2556
2557       tmp_list3 = tmp_list2 = 0;
2558       verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE);
2559       warn_for_collisions (tmp_list2);
2560       merge_tlist (pbefore_sp, tmp_list3, 0);
2561       /* Rather than add both tmp_nosp and tmp_list2, we have to merge the
2562          two first, to avoid warning for (a ? b++ : b++).  */
2563       merge_tlist (&tmp_nosp, tmp_list2, 0);
2564       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2565       return;
2566
2567     case PREDECREMENT_EXPR:
2568     case PREINCREMENT_EXPR:
2569     case POSTDECREMENT_EXPR:
2570     case POSTINCREMENT_EXPR:
2571       verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x);
2572       return;
2573
2574     case MODIFY_EXPR:
2575       tmp_before = tmp_nosp = tmp_list3 = 0;
2576       verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE);
2577       verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x);
2578       /* Expressions inside the LHS are not ordered wrt. the sequence points
2579          in the RHS.  Example:
2580            *a = (a++, 2)
2581          Despite the fact that the modification of "a" is in the before_sp
2582          list (tmp_before), it conflicts with the use of "a" in the LHS.
2583          We can handle this by adding the contents of tmp_list3
2584          to those of tmp_before, and redoing the collision warnings for that
2585          list.  */
2586       add_tlist (&tmp_before, tmp_list3, x, 1);
2587       warn_for_collisions (tmp_before);
2588       /* Exclude the LHS itself here; we first have to merge it into the
2589          tmp_nosp list.  This is done to avoid warning for "a = a"; if we
2590          didn't exclude the LHS, we'd get it twice, once as a read and once
2591          as a write.  */
2592       add_tlist (pno_sp, tmp_list3, x, 0);
2593       warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1);
2594
2595       merge_tlist (pbefore_sp, tmp_before, 0);
2596       if (warning_candidate_p (TREE_OPERAND (x, 0)))
2597         merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0);
2598       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1);
2599       return;
2600
2601     case CALL_EXPR:
2602       /* We need to warn about conflicts among arguments and conflicts between
2603          args and the function address.  Side effects of the function address,
2604          however, are not ordered by the sequence point of the call.  */
2605       {
2606         call_expr_arg_iterator iter;
2607         tree arg;
2608         tmp_before = tmp_nosp = 0;
2609         verify_tree (CALL_EXPR_FN (x), &tmp_before, &tmp_nosp, NULL_TREE);
2610         FOR_EACH_CALL_EXPR_ARG (arg, iter, x)
2611           {
2612             tmp_list2 = tmp_list3 = 0;
2613             verify_tree (arg, &tmp_list2, &tmp_list3, NULL_TREE);
2614             merge_tlist (&tmp_list3, tmp_list2, 0);
2615             add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0);
2616           }
2617         add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0);
2618         warn_for_collisions (tmp_before);
2619         add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0);
2620         return;
2621       }
2622
2623     case TREE_LIST:
2624       /* Scan all the list, e.g. indices of multi dimensional array.  */
2625       while (x)
2626         {
2627           tmp_before = tmp_nosp = 0;
2628           verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE);
2629           merge_tlist (&tmp_nosp, tmp_before, 0);
2630           add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2631           x = TREE_CHAIN (x);
2632         }
2633       return;
2634
2635     case SAVE_EXPR:
2636       {
2637         struct tlist_cache *t;
2638         for (t = save_expr_cache; t; t = t->next)
2639           if (candidate_equal_p (t->expr, x))
2640             break;
2641
2642         if (!t)
2643           {
2644             t = XOBNEW (&tlist_obstack, struct tlist_cache);
2645             t->next = save_expr_cache;
2646             t->expr = x;
2647             save_expr_cache = t;
2648
2649             tmp_before = tmp_nosp = 0;
2650             verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
2651             warn_for_collisions (tmp_nosp);
2652
2653             tmp_list3 = 0;
2654             while (tmp_nosp)
2655               {
2656                 struct tlist *t = tmp_nosp;
2657                 tmp_nosp = t->next;
2658                 merge_tlist (&tmp_list3, t, 0);
2659               }
2660             t->cache_before_sp = tmp_before;
2661             t->cache_after_sp = tmp_list3;
2662           }
2663         merge_tlist (pbefore_sp, t->cache_before_sp, 1);
2664         add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1);
2665         return;
2666       }
2667
2668     case ADDR_EXPR:
2669       x = TREE_OPERAND (x, 0);
2670       if (DECL_P (x))
2671         return;
2672       writer = 0;
2673       goto restart;
2674
2675     default:
2676       /* For other expressions, simply recurse on their operands.
2677          Manual tail recursion for unary expressions.
2678          Other non-expressions need not be processed.  */
2679       if (cl == tcc_unary)
2680         {
2681           x = TREE_OPERAND (x, 0);
2682           writer = 0;
2683           goto restart;
2684         }
2685       else if (IS_EXPR_CODE_CLASS (cl))
2686         {
2687           int lp;
2688           int max = TREE_OPERAND_LENGTH (x);
2689           for (lp = 0; lp < max; lp++)
2690             {
2691               tmp_before = tmp_nosp = 0;
2692               verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, 0);
2693               merge_tlist (&tmp_nosp, tmp_before, 0);
2694               add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
2695             }
2696         }
2697       return;
2698     }
2699 }
2700
2701 /* Try to warn for undefined behavior in EXPR due to missing sequence
2702    points.  */
2703
2704 void
2705 verify_sequence_points (tree expr)
2706 {
2707   struct tlist *before_sp = 0, *after_sp = 0;
2708
2709   warned_ids = 0;
2710   save_expr_cache = 0;
2711   if (tlist_firstobj == 0)
2712     {
2713       gcc_obstack_init (&tlist_obstack);
2714       tlist_firstobj = (char *) obstack_alloc (&tlist_obstack, 0);
2715     }
2716
2717   verify_tree (expr, &before_sp, &after_sp, 0);
2718   warn_for_collisions (after_sp);
2719   obstack_free (&tlist_obstack, tlist_firstobj);
2720 }
2721 \f
2722 /* Validate the expression after `case' and apply default promotions.  */
2723
2724 static tree
2725 check_case_value (tree value)
2726 {
2727   if (value == NULL_TREE)
2728     return value;
2729
2730   /* ??? Can we ever get nops here for a valid case value?  We
2731      shouldn't for C.  */
2732   STRIP_TYPE_NOPS (value);
2733   /* In C++, the following is allowed:
2734
2735        const int i = 3;
2736        switch (...) { case i: ... }
2737
2738      So, we try to reduce the VALUE to a constant that way.  */
2739   if (c_dialect_cxx ())
2740     {
2741       value = decl_constant_value (value);
2742       STRIP_TYPE_NOPS (value);
2743       value = fold (value);
2744     }
2745
2746   if (TREE_CODE (value) == INTEGER_CST)
2747     /* Promote char or short to int.  */
2748     value = perform_integral_promotions (value);
2749   else if (value != error_mark_node)
2750     {
2751       error ("case label does not reduce to an integer constant");
2752       value = error_mark_node;
2753     }
2754
2755   constant_expression_warning (value);
2756
2757   return value;
2758 }
2759 \f
2760 /* See if the case values LOW and HIGH are in the range of the original
2761    type (i.e. before the default conversion to int) of the switch testing
2762    expression.
2763    TYPE is the promoted type of the testing expression, and ORIG_TYPE is
2764    the type before promoting it.  CASE_LOW_P is a pointer to the lower
2765    bound of the case label, and CASE_HIGH_P is the upper bound or NULL
2766    if the case is not a case range.
2767    The caller has to make sure that we are not called with NULL for
2768    CASE_LOW_P (i.e. the default case).
2769    Returns true if the case label is in range of ORIG_TYPE (saturated or
2770    untouched) or false if the label is out of range.  */
2771
2772 static bool
2773 check_case_bounds (tree type, tree orig_type,
2774                    tree *case_low_p, tree *case_high_p)
2775 {
2776   tree min_value, max_value;
2777   tree case_low = *case_low_p;
2778   tree case_high = case_high_p ? *case_high_p : case_low;
2779
2780   /* If there was a problem with the original type, do nothing.  */
2781   if (orig_type == error_mark_node)
2782     return true;
2783
2784   min_value = TYPE_MIN_VALUE (orig_type);
2785   max_value = TYPE_MAX_VALUE (orig_type);
2786
2787   /* Case label is less than minimum for type.  */
2788   if (tree_int_cst_compare (case_low, min_value) < 0
2789       && tree_int_cst_compare (case_high, min_value) < 0)
2790     {
2791       warning (0, "case label value is less than minimum value for type");
2792       return false;
2793     }
2794
2795   /* Case value is greater than maximum for type.  */
2796   if (tree_int_cst_compare (case_low, max_value) > 0
2797       && tree_int_cst_compare (case_high, max_value) > 0)
2798     {
2799       warning (0, "case label value exceeds maximum value for type");
2800       return false;
2801     }
2802
2803   /* Saturate lower case label value to minimum.  */
2804   if (tree_int_cst_compare (case_high, min_value) >= 0
2805       && tree_int_cst_compare (case_low, min_value) < 0)
2806     {
2807       warning (0, "lower value in case label range"
2808                " less than minimum value for type");
2809       case_low = min_value;
2810     }
2811
2812   /* Saturate upper case label value to maximum.  */
2813   if (tree_int_cst_compare (case_low, max_value) <= 0
2814       && tree_int_cst_compare (case_high, max_value) > 0)
2815     {
2816       warning (0, "upper value in case label range"
2817                " exceeds maximum value for type");
2818       case_high = max_value;
2819     }
2820
2821   if (*case_low_p != case_low)
2822     *case_low_p = convert (type, case_low);
2823   if (case_high_p && *case_high_p != case_high)
2824     *case_high_p = convert (type, case_high);
2825
2826   return true;
2827 }
2828 \f
2829 /* Return an integer type with BITS bits of precision,
2830    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
2831
2832 tree
2833 c_common_type_for_size (unsigned int bits, int unsignedp)
2834 {
2835   if (bits == TYPE_PRECISION (integer_type_node))
2836     return unsignedp ? unsigned_type_node : integer_type_node;
2837
2838   if (bits == TYPE_PRECISION (signed_char_type_node))
2839     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2840
2841   if (bits == TYPE_PRECISION (short_integer_type_node))
2842     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2843
2844   if (bits == TYPE_PRECISION (long_integer_type_node))
2845     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2846
2847   if (bits == TYPE_PRECISION (long_long_integer_type_node))
2848     return (unsignedp ? long_long_unsigned_type_node
2849             : long_long_integer_type_node);
2850
2851   if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
2852     return (unsignedp ? widest_unsigned_literal_type_node
2853             : widest_integer_literal_type_node);
2854
2855   if (bits <= TYPE_PRECISION (intQI_type_node))
2856     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2857
2858   if (bits <= TYPE_PRECISION (intHI_type_node))
2859     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2860
2861   if (bits <= TYPE_PRECISION (intSI_type_node))
2862     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2863
2864   if (bits <= TYPE_PRECISION (intDI_type_node))
2865     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2866
2867   return 0;
2868 }
2869
2870 /* Return a fixed-point type that has at least IBIT ibits and FBIT fbits
2871    that is unsigned if UNSIGNEDP is nonzero, otherwise signed;
2872    and saturating if SATP is nonzero, otherwise not saturating.  */
2873
2874 tree
2875 c_common_fixed_point_type_for_size (unsigned int ibit, unsigned int fbit,
2876                                     int unsignedp, int satp)
2877 {
2878   enum machine_mode mode;
2879   if (ibit == 0)
2880     mode = unsignedp ? UQQmode : QQmode;
2881   else
2882     mode = unsignedp ? UHAmode : HAmode;
2883
2884   for (; mode != VOIDmode; mode = GET_MODE_WIDER_MODE (mode))
2885     if (GET_MODE_IBIT (mode) >= ibit && GET_MODE_FBIT (mode) >= fbit)
2886       break;
2887
2888   if (mode == VOIDmode || !targetm.scalar_mode_supported_p (mode))
2889     {
2890       sorry ("GCC cannot support operators with integer types and "
2891              "fixed-point types that have too many integral and "
2892              "fractional bits together");
2893       return 0;
2894     }
2895
2896   return c_common_type_for_mode (mode, satp);
2897 }
2898
2899 /* Used for communication between c_common_type_for_mode and
2900    c_register_builtin_type.  */
2901 static GTY(()) tree registered_builtin_types;
2902
2903 /* Return a data type that has machine mode MODE.
2904    If the mode is an integer,
2905    then UNSIGNEDP selects between signed and unsigned types.
2906    If the mode is a fixed-point mode,
2907    then UNSIGNEDP selects between saturating and nonsaturating types.  */
2908
2909 tree
2910 c_common_type_for_mode (enum machine_mode mode, int unsignedp)
2911 {
2912   tree t;
2913
2914   if (mode == TYPE_MODE (integer_type_node))
2915     return unsignedp ? unsigned_type_node : integer_type_node;
2916
2917   if (mode == TYPE_MODE (signed_char_type_node))
2918     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2919
2920   if (mode == TYPE_MODE (short_integer_type_node))
2921     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2922
2923   if (mode == TYPE_MODE (long_integer_type_node))
2924     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2925
2926   if (mode == TYPE_MODE (long_long_integer_type_node))
2927     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
2928
2929   if (mode == TYPE_MODE (widest_integer_literal_type_node))
2930     return unsignedp ? widest_unsigned_literal_type_node
2931                      : widest_integer_literal_type_node;
2932
2933   if (mode == QImode)
2934     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2935
2936   if (mode == HImode)
2937     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2938
2939   if (mode == SImode)
2940     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2941
2942   if (mode == DImode)
2943     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2944
2945 #if HOST_BITS_PER_WIDE_INT >= 64
2946   if (mode == TYPE_MODE (intTI_type_node))
2947     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
2948 #endif
2949
2950   if (mode == TYPE_MODE (float_type_node))
2951     return float_type_node;
2952
2953   if (mode == TYPE_MODE (double_type_node))
2954     return double_type_node;
2955
2956   if (mode == TYPE_MODE (long_double_type_node))
2957     return long_double_type_node;
2958
2959   if (mode == TYPE_MODE (void_type_node))
2960     return void_type_node;
2961
2962   if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
2963     return (unsignedp
2964             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2965             : make_signed_type (GET_MODE_PRECISION (mode)));
2966
2967   if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
2968     return (unsignedp
2969             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2970             : make_signed_type (GET_MODE_PRECISION (mode)));
2971
2972   if (COMPLEX_MODE_P (mode))
2973     {
2974       enum machine_mode inner_mode;
2975       tree inner_type;
2976
2977       if (mode == TYPE_MODE (complex_float_type_node))
2978         return complex_float_type_node;
2979       if (mode == TYPE_MODE (complex_double_type_node))
2980         return complex_double_type_node;
2981       if (mode == TYPE_MODE (complex_long_double_type_node))
2982         return complex_long_double_type_node;
2983
2984       if (mode == TYPE_MODE (complex_integer_type_node) && !unsignedp)
2985         return complex_integer_type_node;
2986
2987       inner_mode = GET_MODE_INNER (mode);
2988       inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2989       if (inner_type != NULL_TREE)
2990         return build_complex_type (inner_type);
2991     }
2992   else if (VECTOR_MODE_P (mode))
2993     {
2994       enum machine_mode inner_mode = GET_MODE_INNER (mode);
2995       tree inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2996       if (inner_type != NULL_TREE)
2997         return build_vector_type_for_mode (inner_type, mode);
2998     }
2999
3000   if (mode == TYPE_MODE (dfloat32_type_node))
3001     return dfloat32_type_node;
3002   if (mode == TYPE_MODE (dfloat64_type_node))
3003     return dfloat64_type_node;
3004   if (mode == TYPE_MODE (dfloat128_type_node))
3005     return dfloat128_type_node;
3006
3007   if (ALL_SCALAR_FIXED_POINT_MODE_P (mode))
3008     {
3009       if (mode == TYPE_MODE (short_fract_type_node))
3010         return unsignedp ? sat_short_fract_type_node : short_fract_type_node;
3011       if (mode == TYPE_MODE (fract_type_node))
3012         return unsignedp ? sat_fract_type_node : fract_type_node;
3013       if (mode == TYPE_MODE (long_fract_type_node))
3014         return unsignedp ? sat_long_fract_type_node : long_fract_type_node;
3015       if (mode == TYPE_MODE (long_long_fract_type_node))
3016         return unsignedp ? sat_long_long_fract_type_node
3017                          : long_long_fract_type_node;
3018
3019       if (mode == TYPE_MODE (unsigned_short_fract_type_node))
3020         return unsignedp ? sat_unsigned_short_fract_type_node
3021                          : unsigned_short_fract_type_node;
3022       if (mode == TYPE_MODE (unsigned_fract_type_node))
3023         return unsignedp ? sat_unsigned_fract_type_node
3024                          : unsigned_fract_type_node;
3025       if (mode == TYPE_MODE (unsigned_long_fract_type_node))
3026         return unsignedp ? sat_unsigned_long_fract_type_node
3027                          : unsigned_long_fract_type_node;
3028       if (mode == TYPE_MODE (unsigned_long_long_fract_type_node))
3029         return unsignedp ? sat_unsigned_long_long_fract_type_node
3030                          : unsigned_long_long_fract_type_node;
3031
3032       if (mode == TYPE_MODE (short_accum_type_node))
3033         return unsignedp ? sat_short_accum_type_node : short_accum_type_node;
3034       if (mode == TYPE_MODE (accum_type_node))
3035         return unsignedp ? sat_accum_type_node : accum_type_node;
3036       if (mode == TYPE_MODE (long_accum_type_node))
3037         return unsignedp ? sat_long_accum_type_node : long_accum_type_node;
3038       if (mode == TYPE_MODE (long_long_accum_type_node))
3039         return unsignedp ? sat_long_long_accum_type_node
3040                          : long_long_accum_type_node;
3041
3042       if (mode == TYPE_MODE (unsigned_short_accum_type_node))
3043         return unsignedp ? sat_unsigned_short_accum_type_node
3044                          : unsigned_short_accum_type_node;
3045       if (mode == TYPE_MODE (unsigned_accum_type_node))
3046         return unsignedp ? sat_unsigned_accum_type_node
3047                          : unsigned_accum_type_node;
3048       if (mode == TYPE_MODE (unsigned_long_accum_type_node))
3049         return unsignedp ? sat_unsigned_long_accum_type_node
3050                          : unsigned_long_accum_type_node;
3051       if (mode == TYPE_MODE (unsigned_long_long_accum_type_node))
3052         return unsignedp ? sat_unsigned_long_long_accum_type_node
3053                          : unsigned_long_long_accum_type_node;
3054
3055       if (mode == QQmode)
3056         return unsignedp ? sat_qq_type_node : qq_type_node;
3057       if (mode == HQmode)
3058         return unsignedp ? sat_hq_type_node : hq_type_node;
3059       if (mode == SQmode)
3060         return unsignedp ? sat_sq_type_node : sq_type_node;
3061       if (mode == DQmode)
3062         return unsignedp ? sat_dq_type_node : dq_type_node;
3063       if (mode == TQmode)
3064         return unsignedp ? sat_tq_type_node : tq_type_node;
3065
3066       if (mode == UQQmode)
3067         return unsignedp ? sat_uqq_type_node : uqq_type_node;
3068       if (mode == UHQmode)
3069         return unsignedp ? sat_uhq_type_node : uhq_type_node;
3070       if (mode == USQmode)
3071         return unsignedp ? sat_usq_type_node : usq_type_node;
3072       if (mode == UDQmode)
3073         return unsignedp ? sat_udq_type_node : udq_type_node;
3074       if (mode == UTQmode)
3075         return unsignedp ? sat_utq_type_node : utq_type_node;
3076
3077       if (mode == HAmode)
3078         return unsignedp ? sat_ha_type_node : ha_type_node;
3079       if (mode == SAmode)
3080         return unsignedp ? sat_sa_type_node : sa_type_node;
3081       if (mode == DAmode)
3082         return unsignedp ? sat_da_type_node : da_type_node;
3083       if (mode == TAmode)
3084         return unsignedp ? sat_ta_type_node : ta_type_node;
3085
3086       if (mode == UHAmode)
3087         return unsignedp ? sat_uha_type_node : uha_type_node;
3088       if (mode == USAmode)
3089         return unsignedp ? sat_usa_type_node : usa_type_node;
3090       if (mode == UDAmode)
3091         return unsignedp ? sat_uda_type_node : uda_type_node;
3092       if (mode == UTAmode)
3093         return unsignedp ? sat_uta_type_node : uta_type_node;
3094     }
3095
3096   for (t = registered_builtin_types; t; t = TREE_CHAIN (t))
3097     if (TYPE_MODE (TREE_VALUE (t)) == mode)
3098       return TREE_VALUE (t);
3099
3100   return 0;
3101 }
3102
3103 tree
3104 c_common_unsigned_type (tree type)
3105 {
3106   return c_common_signed_or_unsigned_type (1, type);
3107 }
3108
3109 /* Return a signed type the same as TYPE in other respects.  */
3110
3111 tree
3112 c_common_signed_type (tree type)
3113 {
3114   return c_common_signed_or_unsigned_type (0, type);
3115 }
3116
3117 /* Return a type the same as TYPE except unsigned or
3118    signed according to UNSIGNEDP.  */
3119
3120 tree
3121 c_common_signed_or_unsigned_type (int unsignedp, tree type)
3122 {
3123   tree type1;
3124
3125   /* This block of code emulates the behavior of the old
3126      c_common_unsigned_type. In particular, it returns
3127      long_unsigned_type_node if passed a long, even when a int would
3128      have the same size. This is necessary for warnings to work
3129      correctly in archs where sizeof(int) == sizeof(long) */
3130
3131   type1 = TYPE_MAIN_VARIANT (type);
3132   if (type1 == signed_char_type_node || type1 == char_type_node || type1 == unsigned_char_type_node)
3133     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3134   if (type1 == integer_type_node || type1 == unsigned_type_node)
3135     return unsignedp ? unsigned_type_node : integer_type_node;
3136   if (type1 == short_integer_type_node || type1 == short_unsigned_type_node)
3137     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3138   if (type1 == long_integer_type_node || type1 == long_unsigned_type_node)
3139     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3140   if (type1 == long_long_integer_type_node || type1 == long_long_unsigned_type_node)
3141     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
3142   if (type1 == widest_integer_literal_type_node || type1 == widest_unsigned_literal_type_node)
3143     return unsignedp ? widest_unsigned_literal_type_node : widest_integer_literal_type_node;
3144 #if HOST_BITS_PER_WIDE_INT >= 64
3145   if (type1 == intTI_type_node || type1 == unsigned_intTI_type_node)
3146     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
3147 #endif
3148   if (type1 == intDI_type_node || type1 == unsigned_intDI_type_node)
3149     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
3150   if (type1 == intSI_type_node || type1 == unsigned_intSI_type_node)
3151     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
3152   if (type1 == intHI_type_node || type1 == unsigned_intHI_type_node)
3153     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
3154   if (type1 == intQI_type_node || type1 == unsigned_intQI_type_node)
3155     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
3156
3157 #define C_COMMON_FIXED_TYPES(NAME)          \
3158   if (type1 == short_ ## NAME ## _type_node \
3159       || type1 == unsigned_short_ ## NAME ## _type_node) \
3160     return unsignedp ? unsigned_short_ ## NAME ## _type_node \
3161                      : short_ ## NAME ## _type_node; \
3162   if (type1 == NAME ## _type_node \
3163       || type1 == unsigned_ ## NAME ## _type_node) \
3164     return unsignedp ? unsigned_ ## NAME ## _type_node \
3165                      : NAME ## _type_node; \
3166   if (type1 == long_ ## NAME ## _type_node \
3167       || type1 == unsigned_long_ ## NAME ## _type_node) \
3168     return unsignedp ? unsigned_long_ ## NAME ## _type_node \
3169                      : long_ ## NAME ## _type_node; \
3170   if (type1 == long_long_ ## NAME ## _type_node \
3171       || type1 == unsigned_long_long_ ## NAME ## _type_node) \
3172     return unsignedp ? unsigned_long_long_ ## NAME ## _type_node \
3173                      : long_long_ ## NAME ## _type_node;
3174
3175 #define C_COMMON_FIXED_MODE_TYPES(NAME) \
3176   if (type1 == NAME ## _type_node \
3177       || type1 == u ## NAME ## _type_node) \
3178     return unsignedp ? u ## NAME ## _type_node \
3179                      : NAME ## _type_node;
3180
3181 #define C_COMMON_FIXED_TYPES_SAT(NAME) \
3182   if (type1 == sat_ ## short_ ## NAME ## _type_node \
3183       || type1 == sat_ ## unsigned_short_ ## NAME ## _type_node) \
3184     return unsignedp ? sat_ ## unsigned_short_ ## NAME ## _type_node \
3185                      : sat_ ## short_ ## NAME ## _type_node; \
3186   if (type1 == sat_ ## NAME ## _type_node \
3187       || type1 == sat_ ## unsigned_ ## NAME ## _type_node) \
3188     return unsignedp ? sat_ ## unsigned_ ## NAME ## _type_node \
3189                      : sat_ ## NAME ## _type_node; \
3190   if (type1 == sat_ ## long_ ## NAME ## _type_node \
3191       || type1 == sat_ ## unsigned_long_ ## NAME ## _type_node) \
3192     return unsignedp ? sat_ ## unsigned_long_ ## NAME ## _type_node \
3193                      : sat_ ## long_ ## NAME ## _type_node; \
3194   if (type1 == sat_ ## long_long_ ## NAME ## _type_node \
3195       || type1 == sat_ ## unsigned_long_long_ ## NAME ## _type_node) \
3196     return unsignedp ? sat_ ## unsigned_long_long_ ## NAME ## _type_node \
3197                      : sat_ ## long_long_ ## NAME ## _type_node;
3198
3199 #define C_COMMON_FIXED_MODE_TYPES_SAT(NAME)     \
3200   if (type1 == sat_ ## NAME ## _type_node \
3201       || type1 == sat_ ## u ## NAME ## _type_node) \
3202     return unsignedp ? sat_ ## u ## NAME ## _type_node \
3203                      : sat_ ## NAME ## _type_node;
3204
3205   C_COMMON_FIXED_TYPES (fract);
3206   C_COMMON_FIXED_TYPES_SAT (fract);
3207   C_COMMON_FIXED_TYPES (accum);
3208   C_COMMON_FIXED_TYPES_SAT (accum);
3209
3210   C_COMMON_FIXED_MODE_TYPES (qq);
3211   C_COMMON_FIXED_MODE_TYPES (hq);
3212   C_COMMON_FIXED_MODE_TYPES (sq);
3213   C_COMMON_FIXED_MODE_TYPES (dq);
3214   C_COMMON_FIXED_MODE_TYPES (tq);
3215   C_COMMON_FIXED_MODE_TYPES_SAT (qq);
3216   C_COMMON_FIXED_MODE_TYPES_SAT (hq);
3217   C_COMMON_FIXED_MODE_TYPES_SAT (sq);
3218   C_COMMON_FIXED_MODE_TYPES_SAT (dq);
3219   C_COMMON_FIXED_MODE_TYPES_SAT (tq);
3220   C_COMMON_FIXED_MODE_TYPES (ha);
3221   C_COMMON_FIXED_MODE_TYPES (sa);
3222   C_COMMON_FIXED_MODE_TYPES (da);
3223   C_COMMON_FIXED_MODE_TYPES (ta);
3224   C_COMMON_FIXED_MODE_TYPES_SAT (ha);
3225   C_COMMON_FIXED_MODE_TYPES_SAT (sa);
3226   C_COMMON_FIXED_MODE_TYPES_SAT (da);
3227   C_COMMON_FIXED_MODE_TYPES_SAT (ta);
3228
3229   /* For ENUMERAL_TYPEs in C++, must check the mode of the types, not
3230      the precision; they have precision set to match their range, but
3231      may use a wider mode to match an ABI.  If we change modes, we may
3232      wind up with bad conversions.  For INTEGER_TYPEs in C, must check
3233      the precision as well, so as to yield correct results for
3234      bit-field types.  C++ does not have these separate bit-field
3235      types, and producing a signed or unsigned variant of an
3236      ENUMERAL_TYPE may cause other problems as well.  */
3237
3238   if (!INTEGRAL_TYPE_P (type)
3239       || TYPE_UNSIGNED (type) == unsignedp)
3240     return type;
3241
3242 #define TYPE_OK(node)                                                       \
3243   (TYPE_MODE (type) == TYPE_MODE (node)                                     \
3244    && TYPE_PRECISION (type) == TYPE_PRECISION (node))
3245   if (TYPE_OK (signed_char_type_node))
3246     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3247   if (TYPE_OK (integer_type_node))
3248     return unsignedp ? unsigned_type_node : integer_type_node;
3249   if (TYPE_OK (short_integer_type_node))
3250     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3251   if (TYPE_OK (long_integer_type_node))
3252     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3253   if (TYPE_OK (long_long_integer_type_node))
3254     return (unsignedp ? long_long_unsigned_type_node
3255             : long_long_integer_type_node);
3256   if (TYPE_OK (widest_integer_literal_type_node))
3257     return (unsignedp ? widest_unsigned_literal_type_node
3258             : widest_integer_literal_type_node);
3259
3260 #if HOST_BITS_PER_WIDE_INT >= 64
3261   if (TYPE_OK (intTI_type_node))
3262     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
3263 #endif
3264   if (TYPE_OK (intDI_type_node))
3265     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
3266   if (TYPE_OK (intSI_type_node))
3267     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
3268   if (TYPE_OK (intHI_type_node))
3269     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
3270   if (TYPE_OK (intQI_type_node))
3271     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
3272 #undef TYPE_OK
3273
3274   return build_nonstandard_integer_type (TYPE_PRECISION (type), unsignedp);
3275 }
3276
3277 /* Build a bit-field integer type for the given WIDTH and UNSIGNEDP.  */
3278
3279 tree
3280 c_build_bitfield_integer_type (unsigned HOST_WIDE_INT width, int unsignedp)
3281 {
3282   /* Extended integer types of the same width as a standard type have
3283      lesser rank, so those of the same width as int promote to int or
3284      unsigned int and are valid for printf formats expecting int or
3285      unsigned int.  To avoid such special cases, avoid creating
3286      extended integer types for bit-fields if a standard integer type
3287      is available.  */
3288   if (width == TYPE_PRECISION (integer_type_node))
3289     return unsignedp ? unsigned_type_node : integer_type_node;
3290   if (width == TYPE_PRECISION (signed_char_type_node))
3291     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
3292   if (width == TYPE_PRECISION (short_integer_type_node))
3293     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
3294   if (width == TYPE_PRECISION (long_integer_type_node))
3295     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
3296   if (width == TYPE_PRECISION (long_long_integer_type_node))
3297     return (unsignedp ? long_long_unsigned_type_node
3298             : long_long_integer_type_node);
3299   return build_nonstandard_integer_type (width, unsignedp);
3300 }
3301
3302 /* The C version of the register_builtin_type langhook.  */
3303
3304 void
3305 c_register_builtin_type (tree type, const char* name)
3306 {
3307   tree decl;
3308
3309   decl = build_decl (UNKNOWN_LOCATION,
3310                      TYPE_DECL, get_identifier (name), type);
3311   DECL_ARTIFICIAL (decl) = 1;
3312   if (!TYPE_NAME (type))
3313     TYPE_NAME (type) = decl;
3314   pushdecl (decl);
3315
3316   registered_builtin_types = tree_cons (0, type, registered_builtin_types);
3317 }
3318 \f
3319 /* Print an error message for invalid operands to arith operation
3320    CODE with TYPE0 for operand 0, and TYPE1 for operand 1.
3321    LOCATION is the location of the message.  */
3322
3323 void
3324 binary_op_error (location_t location, enum tree_code code,
3325                  tree type0, tree type1)
3326 {
3327   const char *opname;
3328
3329   switch (code)
3330     {
3331     case PLUS_EXPR:
3332       opname = "+"; break;
3333     case MINUS_EXPR:
3334       opname = "-"; break;
3335     case MULT_EXPR:
3336       opname = "*"; break;
3337     case MAX_EXPR:
3338       opname = "max"; break;
3339     case MIN_EXPR:
3340       opname = "min"; break;
3341     case EQ_EXPR:
3342       opname = "=="; break;
3343     case NE_EXPR:
3344       opname = "!="; break;
3345     case LE_EXPR:
3346       opname = "<="; break;
3347     case GE_EXPR:
3348       opname = ">="; break;
3349     case LT_EXPR:
3350       opname = "<"; break;
3351     case GT_EXPR:
3352       opname = ">"; break;
3353     case LSHIFT_EXPR:
3354       opname = "<<"; break;
3355     case RSHIFT_EXPR:
3356       opname = ">>"; break;
3357     case TRUNC_MOD_EXPR:
3358     case FLOOR_MOD_EXPR:
3359       opname = "%"; break;
3360     case TRUNC_DIV_EXPR:
3361     case FLOOR_DIV_EXPR:
3362       opname = "/"; break;
3363     case BIT_AND_EXPR:
3364       opname = "&"; break;
3365     case BIT_IOR_EXPR:
3366       opname = "|"; break;
3367     case TRUTH_ANDIF_EXPR:
3368       opname = "&&"; break;
3369     case TRUTH_ORIF_EXPR:
3370       opname = "||"; break;
3371     case BIT_XOR_EXPR:
3372       opname = "^"; break;
3373     default:
3374       gcc_unreachable ();
3375     }
3376   error_at (location,
3377             "invalid operands to binary %s (have %qT and %qT)", opname,
3378             type0, type1);
3379 }
3380 \f
3381 /* Subroutine of build_binary_op, used for comparison operations.
3382    See if the operands have both been converted from subword integer types
3383    and, if so, perhaps change them both back to their original type.
3384    This function is also responsible for converting the two operands
3385    to the proper common type for comparison.
3386
3387    The arguments of this function are all pointers to local variables
3388    of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
3389    RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.
3390
3391    If this function returns nonzero, it means that the comparison has
3392    a constant value.  What this function returns is an expression for
3393    that value.  */
3394
3395 tree
3396 shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr,
3397                  enum tree_code *rescode_ptr)
3398 {
3399   tree type;
3400   tree op0 = *op0_ptr;
3401   tree op1 = *op1_ptr;
3402   int unsignedp0, unsignedp1;
3403   int real1, real2;
3404   tree primop0, primop1;
3405   enum tree_code code = *rescode_ptr;
3406
3407   /* Throw away any conversions to wider types
3408      already present in the operands.  */
3409
3410   primop0 = get_narrower (op0, &unsignedp0);
3411   primop1 = get_narrower (op1, &unsignedp1);
3412
3413   /* Handle the case that OP0 does not *contain* a conversion
3414      but it *requires* conversion to FINAL_TYPE.  */
3415
3416   if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
3417     unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3418   if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
3419     unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3420
3421   /* If one of the operands must be floated, we cannot optimize.  */
3422   real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
3423   real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
3424
3425   /* If first arg is constant, swap the args (changing operation
3426      so value is preserved), for canonicalization.  Don't do this if
3427      the second arg is 0.  */
3428
3429   if (TREE_CONSTANT (primop0)
3430       && !integer_zerop (primop1) && !real_zerop (primop1)
3431       && !fixed_zerop (primop1))
3432     {
3433       tree tem = primop0;
3434       int temi = unsignedp0;
3435       primop0 = primop1;
3436       primop1 = tem;
3437       tem = op0;
3438       op0 = op1;
3439       op1 = tem;
3440       *op0_ptr = op0;
3441       *op1_ptr = op1;
3442       unsignedp0 = unsignedp1;
3443       unsignedp1 = temi;
3444       temi = real1;
3445       real1 = real2;
3446       real2 = temi;
3447
3448       switch (code)
3449         {
3450         case LT_EXPR:
3451           code = GT_EXPR;
3452           break;
3453         case GT_EXPR:
3454           code = LT_EXPR;
3455           break;
3456         case LE_EXPR:
3457           code = GE_EXPR;
3458           break;
3459         case GE_EXPR:
3460           code = LE_EXPR;
3461           break;
3462         default:
3463           break;
3464         }
3465       *rescode_ptr = code;
3466     }
3467
3468   /* If comparing an integer against a constant more bits wide,
3469      maybe we can deduce a value of 1 or 0 independent of the data.
3470      Or else truncate the constant now
3471      rather than extend the variable at run time.
3472
3473      This is only interesting if the constant is the wider arg.
3474      Also, it is not safe if the constant is unsigned and the
3475      variable arg is signed, since in this case the variable
3476      would be sign-extended and then regarded as unsigned.
3477      Our technique fails in this case because the lowest/highest
3478      possible unsigned results don't follow naturally from the
3479      lowest/highest possible values of the variable operand.
3480      For just EQ_EXPR and NE_EXPR there is another technique that
3481      could be used: see if the constant can be faithfully represented
3482      in the other operand's type, by truncating it and reextending it
3483      and see if that preserves the constant's value.  */
3484
3485   if (!real1 && !real2
3486       && TREE_CODE (TREE_TYPE (primop0)) != FIXED_POINT_TYPE
3487       && TREE_CODE (primop1) == INTEGER_CST
3488       && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
3489     {
3490       int min_gt, max_gt, min_lt, max_lt;
3491       tree maxval, minval;
3492       /* 1 if comparison is nominally unsigned.  */
3493       int unsignedp = TYPE_UNSIGNED (*restype_ptr);
3494       tree val;
3495
3496       type = c_common_signed_or_unsigned_type (unsignedp0,
3497                                                TREE_TYPE (primop0));
3498
3499       maxval = TYPE_MAX_VALUE (type);
3500       minval = TYPE_MIN_VALUE (type);
3501
3502       if (unsignedp && !unsignedp0)
3503         *restype_ptr = c_common_signed_type (*restype_ptr);
3504
3505       if (TREE_TYPE (primop1) != *restype_ptr)
3506         {
3507           /* Convert primop1 to target type, but do not introduce
3508              additional overflow.  We know primop1 is an int_cst.  */
3509           primop1 = force_fit_type_double (*restype_ptr,
3510                                            TREE_INT_CST_LOW (primop1),
3511                                            TREE_INT_CST_HIGH (primop1), 0,
3512                                            TREE_OVERFLOW (primop1));
3513         }
3514       if (type != *restype_ptr)
3515         {
3516           minval = convert (*restype_ptr, minval);
3517           maxval = convert (*restype_ptr, maxval);
3518         }
3519
3520       if (unsignedp && unsignedp0)
3521         {
3522           min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
3523           max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
3524           min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
3525           max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
3526         }
3527       else
3528         {
3529           min_gt = INT_CST_LT (primop1, minval);
3530           max_gt = INT_CST_LT (primop1, maxval);
3531           min_lt = INT_CST_LT (minval, primop1);
3532           max_lt = INT_CST_LT (maxval, primop1);
3533         }
3534
3535       val = 0;
3536       /* This used to be a switch, but Genix compiler can't handle that.  */
3537       if (code == NE_EXPR)
3538         {
3539           if (max_lt || min_gt)
3540             val = truthvalue_true_node;
3541         }
3542       else if (code == EQ_EXPR)
3543         {
3544           if (max_lt || min_gt)
3545             val = truthvalue_false_node;
3546         }
3547       else if (code == LT_EXPR)
3548         {
3549           if (max_lt)
3550             val = truthvalue_true_node;
3551           if (!min_lt)
3552             val = truthvalue_false_node;
3553         }
3554       else if (code == GT_EXPR)
3555         {
3556           if (min_gt)
3557             val = truthvalue_true_node;
3558           if (!max_gt)
3559             val = truthvalue_false_node;
3560         }
3561       else if (code == LE_EXPR)
3562         {
3563           if (!max_gt)
3564             val = truthvalue_true_node;
3565           if (min_gt)
3566             val = truthvalue_false_node;
3567         }
3568       else if (code == GE_EXPR)
3569         {
3570           if (!min_lt)
3571             val = truthvalue_true_node;
3572           if (max_lt)
3573             val = truthvalue_false_node;
3574         }
3575
3576       /* If primop0 was sign-extended and unsigned comparison specd,
3577          we did a signed comparison above using the signed type bounds.
3578          But the comparison we output must be unsigned.
3579
3580          Also, for inequalities, VAL is no good; but if the signed
3581          comparison had *any* fixed result, it follows that the
3582          unsigned comparison just tests the sign in reverse
3583          (positive values are LE, negative ones GE).
3584          So we can generate an unsigned comparison
3585          against an extreme value of the signed type.  */
3586
3587       if (unsignedp && !unsignedp0)
3588         {
3589           if (val != 0)
3590             switch (code)
3591               {
3592               case LT_EXPR:
3593               case GE_EXPR:
3594                 primop1 = TYPE_MIN_VALUE (type);
3595                 val = 0;
3596                 break;
3597
3598               case LE_EXPR:
3599               case GT_EXPR:
3600                 primop1 = TYPE_MAX_VALUE (type);
3601                 val = 0;
3602                 break;
3603
3604               default:
3605                 break;
3606               }
3607           type = c_common_unsigned_type (type);
3608         }
3609
3610       if (TREE_CODE (primop0) != INTEGER_CST)
3611         {
3612           if (val == truthvalue_false_node)
3613             warning (OPT_Wtype_limits, "comparison is always false due to limited range of data type");
3614           if (val == truthvalue_true_node)
3615             warning (OPT_Wtype_limits, "comparison is always true due to limited range of data type");
3616         }
3617
3618       if (val != 0)
3619         {
3620           /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
3621           if (TREE_SIDE_EFFECTS (primop0))
3622             return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
3623           return val;
3624         }
3625
3626       /* Value is not predetermined, but do the comparison
3627          in the type of the operand that is not constant.
3628          TYPE is already properly set.  */
3629     }
3630
3631   /* If either arg is decimal float and the other is float, find the
3632      proper common type to use for comparison.  */
3633   else if (real1 && real2
3634            && (DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop0)))
3635                || DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop1)))))
3636     type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
3637
3638   else if (real1 && real2
3639            && (TYPE_PRECISION (TREE_TYPE (primop0))
3640                == TYPE_PRECISION (TREE_TYPE (primop1))))
3641     type = TREE_TYPE (primop0);
3642
3643   /* If args' natural types are both narrower than nominal type
3644      and both extend in the same manner, compare them
3645      in the type of the wider arg.
3646      Otherwise must actually extend both to the nominal
3647      common type lest different ways of extending
3648      alter the result.
3649      (eg, (short)-1 == (unsigned short)-1  should be 0.)  */
3650
3651   else if (unsignedp0 == unsignedp1 && real1 == real2
3652            && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
3653            && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
3654     {
3655       type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
3656       type = c_common_signed_or_unsigned_type (unsignedp0
3657                                                || TYPE_UNSIGNED (*restype_ptr),
3658                                                type);
3659       /* Make sure shorter operand is extended the right way
3660          to match the longer operand.  */
3661       primop0
3662         = convert (c_common_signed_or_unsigned_type (unsignedp0,
3663                                                      TREE_TYPE (primop0)),
3664                    primop0);
3665       primop1
3666         = convert (c_common_signed_or_unsigned_type (unsignedp1,
3667                                                      TREE_TYPE (primop1)),
3668                    primop1);
3669     }
3670   else
3671     {
3672       /* Here we must do the comparison on the nominal type
3673          using the args exactly as we received them.  */
3674       type = *restype_ptr;
3675       primop0 = op0;
3676       primop1 = op1;
3677
3678       if (!real1 && !real2 && integer_zerop (primop1)
3679           && TYPE_UNSIGNED (*restype_ptr))
3680         {
3681           tree value = 0;
3682           switch (code)
3683             {
3684             case GE_EXPR:
3685               /* All unsigned values are >= 0, so we warn.  However,
3686                  if OP0 is a constant that is >= 0, the signedness of
3687                  the comparison isn't an issue, so suppress the
3688                  warning.  */
3689               if (warn_type_limits && !in_system_header
3690                   && !(TREE_CODE (primop0) == INTEGER_CST
3691                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
3692                                                    primop0))))
3693                 warning (OPT_Wtype_limits,
3694                          "comparison of unsigned expression >= 0 is always true");
3695               value = truthvalue_true_node;
3696               break;
3697
3698             case LT_EXPR:
3699               if (warn_type_limits && !in_system_header
3700                   && !(TREE_CODE (primop0) == INTEGER_CST
3701                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
3702                                                    primop0))))
3703                 warning (OPT_Wtype_limits,
3704                          "comparison of unsigned expression < 0 is always false");
3705               value = truthvalue_false_node;
3706               break;
3707
3708             default:
3709               break;
3710             }
3711
3712           if (value != 0)
3713             {
3714               /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
3715               if (TREE_SIDE_EFFECTS (primop0))
3716                 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
3717                                primop0, value);
3718               return value;
3719             }
3720         }
3721     }
3722
3723   *op0_ptr = convert (type, primop0);
3724   *op1_ptr = convert (type, primop1);
3725
3726   *restype_ptr = truthvalue_type_node;
3727
3728   return 0;
3729 }
3730 \f
3731 /* Return a tree for the sum or difference (RESULTCODE says which)
3732    of pointer PTROP and integer INTOP.  */
3733
3734 tree
3735 pointer_int_sum (location_t loc, enum tree_code resultcode,
3736                  tree ptrop, tree intop)
3737 {
3738   tree size_exp, ret;
3739
3740   /* The result is a pointer of the same type that is being added.  */
3741   tree result_type = TREE_TYPE (ptrop);
3742
3743   if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
3744     {
3745       pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3746                "pointer of type %<void *%> used in arithmetic");
3747       size_exp = integer_one_node;
3748     }
3749   else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE)
3750     {
3751       pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3752                "pointer to a function used in arithmetic");
3753       size_exp = integer_one_node;
3754     }
3755   else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE)
3756     {
3757       pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3758                "pointer to member function used in arithmetic");
3759       size_exp = integer_one_node;
3760     }
3761   else
3762     size_exp = size_in_bytes (TREE_TYPE (result_type));
3763
3764   /* We are manipulating pointer values, so we don't need to warn
3765      about relying on undefined signed overflow.  We disable the
3766      warning here because we use integer types so fold won't know that
3767      they are really pointers.  */
3768   fold_defer_overflow_warnings ();
3769
3770   /* If what we are about to multiply by the size of the elements
3771      contains a constant term, apply distributive law
3772      and multiply that constant term separately.
3773      This helps produce common subexpressions.  */
3774   if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
3775       && !TREE_CONSTANT (intop)
3776       && TREE_CONSTANT (TREE_OPERAND (intop, 1))
3777       && TREE_CONSTANT (size_exp)
3778       /* If the constant comes from pointer subtraction,
3779          skip this optimization--it would cause an error.  */
3780       && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
3781       /* If the constant is unsigned, and smaller than the pointer size,
3782          then we must skip this optimization.  This is because it could cause
3783          an overflow error if the constant is negative but INTOP is not.  */
3784       && (!TYPE_UNSIGNED (TREE_TYPE (intop))
3785           || (TYPE_PRECISION (TREE_TYPE (intop))
3786               == TYPE_PRECISION (TREE_TYPE (ptrop)))))
3787     {
3788       enum tree_code subcode = resultcode;
3789       tree int_type = TREE_TYPE (intop);
3790       if (TREE_CODE (intop) == MINUS_EXPR)
3791         subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
3792       /* Convert both subexpression types to the type of intop,
3793          because weird cases involving pointer arithmetic
3794          can result in a sum or difference with different type args.  */
3795       ptrop = build_binary_op (EXPR_LOCATION (TREE_OPERAND (intop, 1)),
3796                                subcode, ptrop,
3797                                convert (int_type, TREE_OPERAND (intop, 1)), 1);
3798       intop = convert (int_type, TREE_OPERAND (intop, 0));
3799     }
3800
3801   /* Convert the integer argument to a type the same size as sizetype
3802      so the multiply won't overflow spuriously.  */
3803   if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype)
3804       || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype))
3805     intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype),
3806                                              TYPE_UNSIGNED (sizetype)), intop);
3807
3808   /* Replace the integer argument with a suitable product by the object size.
3809      Do this multiplication as signed, then convert to the appropriate
3810      type for the pointer operation.  */
3811   intop = convert (sizetype,
3812                    build_binary_op (loc,
3813                                     MULT_EXPR, intop,
3814                                     convert (TREE_TYPE (intop), size_exp), 1));
3815
3816   /* Create the sum or difference.  */
3817   if (resultcode == MINUS_EXPR)
3818     intop = fold_build1_loc (loc, NEGATE_EXPR, sizetype, intop);
3819
3820   ret = fold_build2_loc (loc, POINTER_PLUS_EXPR, result_type, ptrop, intop);
3821
3822   fold_undefer_and_ignore_overflow_warnings ();
3823
3824   return ret;
3825 }
3826 \f
3827 /* Wrap a C_MAYBE_CONST_EXPR around an expression that is fully folded
3828    and if NON_CONST is known not to be permitted in an evaluated part
3829    of a constant expression.  */
3830
3831 tree
3832 c_wrap_maybe_const (tree expr, bool non_const)
3833 {
3834   bool nowarning = TREE_NO_WARNING (expr);
3835   location_t loc = EXPR_LOCATION (expr);
3836
3837   /* This should never be called for C++.  */
3838   if (c_dialect_cxx ())
3839     gcc_unreachable ();
3840
3841   /* The result of folding may have a NOP_EXPR to set TREE_NO_WARNING.  */
3842   STRIP_TYPE_NOPS (expr);
3843   expr = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (expr), NULL, expr);
3844   C_MAYBE_CONST_EXPR_NON_CONST (expr) = non_const;
3845   if (nowarning)
3846     TREE_NO_WARNING (expr) = 1;
3847   protected_set_expr_location (expr, loc);
3848
3849   return expr;
3850 }
3851
3852 /* Wrap a SAVE_EXPR around EXPR, if appropriate.  Like save_expr, but
3853    for C folds the inside expression and wraps a C_MAYBE_CONST_EXPR
3854    around the SAVE_EXPR if needed so that c_fully_fold does not need
3855    to look inside SAVE_EXPRs.  */
3856
3857 tree
3858 c_save_expr (tree expr)
3859 {
3860   bool maybe_const = true;
3861   if (c_dialect_cxx ())
3862     return save_expr (expr);
3863   expr = c_fully_fold (expr, false, &maybe_const);
3864   expr = save_expr (expr);
3865   if (!maybe_const)
3866     expr = c_wrap_maybe_const (expr, true);
3867   return expr;
3868 }
3869
3870 /* Return whether EXPR is a declaration whose address can never be
3871    NULL.  */
3872
3873 bool
3874 decl_with_nonnull_addr_p (const_tree expr)
3875 {
3876   return (DECL_P (expr)
3877           && (TREE_CODE (expr) == PARM_DECL
3878               || TREE_CODE (expr) == LABEL_DECL
3879               || !DECL_WEAK (expr)));
3880 }
3881
3882 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
3883    or for an `if' or `while' statement or ?..: exp.  It should already
3884    have been validated to be of suitable type; otherwise, a bad
3885    diagnostic may result.
3886
3887    The EXPR is located at LOCATION.
3888
3889    This preparation consists of taking the ordinary
3890    representation of an expression expr and producing a valid tree
3891    boolean expression describing whether expr is nonzero.  We could
3892    simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1),
3893    but we optimize comparisons, &&, ||, and !.
3894
3895    The resulting type should always be `truthvalue_type_node'.  */
3896
3897 tree
3898 c_common_truthvalue_conversion (location_t location, tree expr)
3899 {
3900   switch (TREE_CODE (expr))
3901     {
3902     case EQ_EXPR:   case NE_EXPR:   case UNEQ_EXPR: case LTGT_EXPR:
3903     case LE_EXPR:   case GE_EXPR:   case LT_EXPR:   case GT_EXPR:
3904     case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR:
3905     case ORDERED_EXPR: case UNORDERED_EXPR:
3906       if (TREE_TYPE (expr) == truthvalue_type_node)
3907         return expr;
3908       expr = build2 (TREE_CODE (expr), truthvalue_type_node,
3909                      TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1));
3910       goto ret;
3911
3912     case TRUTH_ANDIF_EXPR:
3913     case TRUTH_ORIF_EXPR:
3914     case TRUTH_AND_EXPR:
3915     case TRUTH_OR_EXPR:
3916     case TRUTH_XOR_EXPR:
3917       if (TREE_TYPE (expr) == truthvalue_type_node)
3918         return expr;
3919       expr = build2 (TREE_CODE (expr), truthvalue_type_node,
3920                      c_common_truthvalue_conversion (location,
3921                                                      TREE_OPERAND (expr, 0)),
3922                      c_common_truthvalue_conversion (location,
3923                                                      TREE_OPERAND (expr, 1)));
3924       goto ret;
3925
3926     case TRUTH_NOT_EXPR:
3927       if (TREE_TYPE (expr) == truthvalue_type_node)
3928         return expr;
3929       expr = build1 (TREE_CODE (expr), truthvalue_type_node,
3930                      c_common_truthvalue_conversion (location,
3931                                                      TREE_OPERAND (expr, 0)));
3932       goto ret;
3933
3934     case ERROR_MARK:
3935       return expr;
3936
3937     case INTEGER_CST:
3938       return integer_zerop (expr) ? truthvalue_false_node
3939                                   : truthvalue_true_node;
3940
3941     case REAL_CST:
3942       return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0)
3943              ? truthvalue_true_node
3944              : truthvalue_false_node;
3945
3946     case FIXED_CST:
3947       return fixed_compare (NE_EXPR, &TREE_FIXED_CST (expr),
3948                             &FCONST0 (TYPE_MODE (TREE_TYPE (expr))))
3949              ? truthvalue_true_node
3950              : truthvalue_false_node;
3951
3952     case FUNCTION_DECL:
3953       expr = build_unary_op (location, ADDR_EXPR, expr, 0);
3954       /* Fall through.  */
3955
3956     case ADDR_EXPR:
3957       {
3958         tree inner = TREE_OPERAND (expr, 0);
3959         if (decl_with_nonnull_addr_p (inner))
3960           {
3961             /* Common Ada/Pascal programmer's mistake.  */
3962             warning_at (location,
3963                         OPT_Waddress,
3964                         "the address of %qD will always evaluate as %<true%>",
3965                         inner);
3966             return truthvalue_true_node;
3967           }
3968         break;
3969       }
3970
3971     case COMPLEX_EXPR:
3972       expr = build_binary_op (EXPR_LOCATION (expr),
3973                               (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
3974                                ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
3975                 c_common_truthvalue_conversion (location,
3976                                                 TREE_OPERAND (expr, 0)),
3977                 c_common_truthvalue_conversion (location,
3978                                                 TREE_OPERAND (expr, 1)),
3979                               0);
3980       goto ret;
3981
3982     case NEGATE_EXPR:
3983     case ABS_EXPR:
3984     case FLOAT_EXPR:
3985     case EXCESS_PRECISION_EXPR:
3986       /* These don't change whether an object is nonzero or zero.  */
3987       return c_common_truthvalue_conversion (location, TREE_OPERAND (expr, 0));
3988
3989     case LROTATE_EXPR:
3990     case RROTATE_EXPR:
3991       /* These don't change whether an object is zero or nonzero, but
3992          we can't ignore them if their second arg has side-effects.  */
3993       if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
3994         {
3995           expr = build2 (COMPOUND_EXPR, truthvalue_type_node,
3996                          TREE_OPERAND (expr, 1),
3997                          c_common_truthvalue_conversion
3998                          (location, TREE_OPERAND (expr, 0)));
3999           goto ret;
4000         }
4001       else
4002         return c_common_truthvalue_conversion (location,
4003                                                TREE_OPERAND (expr, 0));
4004
4005     case COND_EXPR:
4006       /* Distribute the conversion into the arms of a COND_EXPR.  */
4007       if (c_dialect_cxx ())
4008         {
4009           expr = fold_build3_loc (location, COND_EXPR, truthvalue_type_node,
4010                               TREE_OPERAND (expr, 0),
4011                               c_common_truthvalue_conversion (location,
4012                                                               TREE_OPERAND (expr,
4013                                                                             1)),
4014                               c_common_truthvalue_conversion (location,
4015                                                               TREE_OPERAND (expr,
4016                                                                             2)));
4017           goto ret;
4018         }
4019       else
4020         {
4021           /* Folding will happen later for C.  */
4022           expr = build3 (COND_EXPR, truthvalue_type_node,
4023                          TREE_OPERAND (expr, 0),
4024                          c_common_truthvalue_conversion (location,
4025                                                          TREE_OPERAND (expr, 1)),
4026                          c_common_truthvalue_conversion (location,
4027                                                          TREE_OPERAND (expr, 2)));
4028           goto ret;
4029         }
4030
4031     CASE_CONVERT:
4032       /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
4033          since that affects how `default_conversion' will behave.  */
4034       if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
4035           || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
4036         break;
4037       /* If this is widening the argument, we can ignore it.  */
4038       if (TYPE_PRECISION (TREE_TYPE (expr))
4039           >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
4040         return c_common_truthvalue_conversion (location,
4041                                                TREE_OPERAND (expr, 0));
4042       break;
4043
4044     case MODIFY_EXPR:
4045       if (!TREE_NO_WARNING (expr)
4046           && warn_parentheses)
4047         {
4048           warning (OPT_Wparentheses,
4049                    "suggest parentheses around assignment used as truth value");
4050           TREE_NO_WARNING (expr) = 1;
4051         }
4052       break;
4053
4054     default:
4055       break;
4056     }
4057
4058   if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
4059     {
4060       tree t = c_save_expr (expr);
4061       expr = (build_binary_op
4062               (EXPR_LOCATION (expr),
4063                (TREE_SIDE_EFFECTS (expr)
4064                 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
4065         c_common_truthvalue_conversion
4066                (location,
4067                 build_unary_op (location, REALPART_EXPR, t, 0)),
4068         c_common_truthvalue_conversion
4069                (location,
4070                 build_unary_op (location, IMAGPART_EXPR, t, 0)),
4071                0));
4072       goto ret;
4073     }
4074
4075   if (TREE_CODE (TREE_TYPE (expr)) == FIXED_POINT_TYPE)
4076     {
4077       tree fixed_zero_node = build_fixed (TREE_TYPE (expr),
4078                                           FCONST0 (TYPE_MODE
4079                                                    (TREE_TYPE (expr))));
4080       return build_binary_op (location, NE_EXPR, expr, fixed_zero_node, 1);
4081     }
4082   else
4083     return build_binary_op (location, NE_EXPR, expr, integer_zero_node, 1);
4084
4085  ret:
4086   protected_set_expr_location (expr, location);
4087   return expr;
4088 }
4089 \f
4090 static void def_builtin_1  (enum built_in_function fncode,
4091                             const char *name,
4092                             enum built_in_class fnclass,
4093                             tree fntype, tree libtype,
4094                             bool both_p, bool fallback_p, bool nonansi_p,
4095                             tree fnattrs, bool implicit_p);
4096
4097
4098 /* Apply the TYPE_QUALS to the new DECL.  */
4099
4100 void
4101 c_apply_type_quals_to_decl (int type_quals, tree decl)
4102 {
4103   tree type = TREE_TYPE (decl);
4104
4105   if (type == error_mark_node)
4106     return;
4107
4108   if (((type_quals & TYPE_QUAL_CONST)
4109        || (type && TREE_CODE (type) == REFERENCE_TYPE))
4110       /* An object declared 'const' is only readonly after it is
4111          initialized.  We don't have any way of expressing this currently,
4112          so we need to be conservative and unset TREE_READONLY for types
4113          with constructors.  Otherwise aliasing code will ignore stores in
4114          an inline constructor.  */
4115       && !(type && TYPE_NEEDS_CONSTRUCTING (type)))
4116     TREE_READONLY (decl) = 1;
4117   if (type_quals & TYPE_QUAL_VOLATILE)
4118     {
4119       TREE_SIDE_EFFECTS (decl) = 1;
4120       TREE_THIS_VOLATILE (decl) = 1;
4121     }
4122   if (type_quals & TYPE_QUAL_RESTRICT)
4123     {
4124       while (type && TREE_CODE (type) == ARRAY_TYPE)
4125         /* Allow 'restrict' on arrays of pointers.
4126            FIXME currently we just ignore it.  */
4127         type = TREE_TYPE (type);
4128       if (!type
4129           || !POINTER_TYPE_P (type)
4130           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))
4131         error ("invalid use of %<restrict%>");
4132     }
4133 }
4134
4135 /* Hash function for the problem of multiple type definitions in
4136    different files.  This must hash all types that will compare
4137    equal via comptypes to the same value.  In practice it hashes
4138    on some of the simple stuff and leaves the details to comptypes.  */
4139
4140 static hashval_t
4141 c_type_hash (const void *p)
4142 {
4143   int i = 0;
4144   int shift, size;
4145   const_tree const t = (const_tree) p;
4146   tree t2;
4147   switch (TREE_CODE (t))
4148     {
4149     /* For pointers, hash on pointee type plus some swizzling.  */
4150     case POINTER_TYPE:
4151       return c_type_hash (TREE_TYPE (t)) ^ 0x3003003;
4152     /* Hash on number of elements and total size.  */
4153     case ENUMERAL_TYPE:
4154       shift = 3;
4155       t2 = TYPE_VALUES (t);
4156       break;
4157     case RECORD_TYPE:
4158       shift = 0;
4159       t2 = TYPE_FIELDS (t);
4160       break;
4161     case QUAL_UNION_TYPE:
4162       shift = 1;
4163       t2 = TYPE_FIELDS (t);
4164       break;
4165     case UNION_TYPE:
4166       shift = 2;
4167       t2 = TYPE_FIELDS (t);
4168       break;
4169     default:
4170       gcc_unreachable ();
4171     }
4172   for (; t2; t2 = TREE_CHAIN (t2))
4173     i++;
4174   /* We might have a VLA here.  */
4175   if (TREE_CODE (TYPE_SIZE (t)) != INTEGER_CST)
4176     size = 0;
4177   else
4178     size = TREE_INT_CST_LOW (TYPE_SIZE (t));
4179   return ((size << 24) | (i << shift));
4180 }
4181
4182 static GTY((param_is (union tree_node))) htab_t type_hash_table;
4183
4184 /* Return the typed-based alias set for T, which may be an expression
4185    or a type.  Return -1 if we don't do anything special.  */
4186
4187 alias_set_type
4188 c_common_get_alias_set (tree t)
4189 {
4190   tree u;
4191   PTR *slot;
4192
4193   /* For VLAs, use the alias set of the element type rather than the
4194      default of alias set 0 for types compared structurally.  */
4195   if (TYPE_P (t) && TYPE_STRUCTURAL_EQUALITY_P (t))
4196     {
4197       if (TREE_CODE (t) == ARRAY_TYPE)
4198         return get_alias_set (TREE_TYPE (t));
4199       return -1;
4200     }
4201
4202   /* Permit type-punning when accessing a union, provided the access
4203      is directly through the union.  For example, this code does not
4204      permit taking the address of a union member and then storing
4205      through it.  Even the type-punning allowed here is a GCC
4206      extension, albeit a common and useful one; the C standard says
4207      that such accesses have implementation-defined behavior.  */
4208   for (u = t;
4209        TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
4210        u = TREE_OPERAND (u, 0))
4211     if (TREE_CODE (u) == COMPONENT_REF
4212         && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
4213       return 0;
4214
4215   /* That's all the expressions we handle specially.  */
4216   if (!TYPE_P (t))
4217     return -1;
4218
4219   /* The C standard guarantees that any object may be accessed via an
4220      lvalue that has character type.  */
4221   if (t == char_type_node
4222       || t == signed_char_type_node
4223       || t == unsigned_char_type_node)
4224     return 0;
4225
4226   /* The C standard specifically allows aliasing between signed and
4227      unsigned variants of the same type.  We treat the signed
4228      variant as canonical.  */
4229   if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t))
4230     {
4231       tree t1 = c_common_signed_type (t);
4232
4233       /* t1 == t can happen for boolean nodes which are always unsigned.  */
4234       if (t1 != t)
4235         return get_alias_set (t1);
4236     }
4237   else if (POINTER_TYPE_P (t))
4238     {
4239       tree t1;
4240
4241       /* Unfortunately, there is no canonical form of a pointer type.
4242          In particular, if we have `typedef int I', then `int *', and
4243          `I *' are different types.  So, we have to pick a canonical
4244          representative.  We do this below.
4245
4246          Technically, this approach is actually more conservative that
4247          it needs to be.  In particular, `const int *' and `int *'
4248          should be in different alias sets, according to the C and C++
4249          standard, since their types are not the same, and so,
4250          technically, an `int **' and `const int **' cannot point at
4251          the same thing.
4252
4253          But, the standard is wrong.  In particular, this code is
4254          legal C++:
4255
4256             int *ip;
4257             int **ipp = &ip;
4258             const int* const* cipp = ipp;
4259
4260          And, it doesn't make sense for that to be legal unless you
4261          can dereference IPP and CIPP.  So, we ignore cv-qualifiers on
4262          the pointed-to types.  This issue has been reported to the
4263          C++ committee.  */
4264       t1 = build_type_no_quals (t);
4265       if (t1 != t)
4266         return get_alias_set (t1);
4267     }
4268
4269   /* Handle the case of multiple type nodes referring to "the same" type,
4270      which occurs with IMA.  These share an alias set.  FIXME:  Currently only
4271      C90 is handled.  (In C99 type compatibility is not transitive, which
4272      complicates things mightily. The alias set splay trees can theoretically
4273      represent this, but insertion is tricky when you consider all the
4274      different orders things might arrive in.) */
4275
4276   if (c_language != clk_c || flag_isoc99)
4277     return -1;
4278
4279   /* Save time if there's only one input file.  */
4280   if (num_in_fnames == 1)
4281     return -1;
4282
4283   /* Pointers need special handling if they point to any type that
4284      needs special handling (below).  */
4285   if (TREE_CODE (t) == POINTER_TYPE)
4286     {
4287       tree t2;
4288       /* Find bottom type under any nested POINTERs.  */
4289       for (t2 = TREE_TYPE (t);
4290            TREE_CODE (t2) == POINTER_TYPE;
4291            t2 = TREE_TYPE (t2))
4292         ;
4293       if (TREE_CODE (t2) != RECORD_TYPE
4294           && TREE_CODE (t2) != ENUMERAL_TYPE
4295           && TREE_CODE (t2) != QUAL_UNION_TYPE
4296           && TREE_CODE (t2) != UNION_TYPE)
4297         return -1;
4298       if (TYPE_SIZE (t2) == 0)
4299         return -1;
4300     }
4301   /* These are the only cases that need special handling.  */
4302   if (TREE_CODE (t) != RECORD_TYPE
4303       && TREE_CODE (t) != ENUMERAL_TYPE
4304       && TREE_CODE (t) != QUAL_UNION_TYPE
4305       && TREE_CODE (t) != UNION_TYPE
4306       && TREE_CODE (t) != POINTER_TYPE)
4307     return -1;
4308   /* Undefined? */
4309   if (TYPE_SIZE (t) == 0)
4310     return -1;
4311
4312   /* Look up t in hash table.  Only one of the compatible types within each
4313      alias set is recorded in the table.  */
4314   if (!type_hash_table)
4315     type_hash_table = htab_create_ggc (1021, c_type_hash,
4316             (htab_eq) lang_hooks.types_compatible_p,
4317             NULL);
4318   slot = htab_find_slot (type_hash_table, t, INSERT);
4319   if (*slot != NULL)
4320     {
4321       TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot);
4322       return TYPE_ALIAS_SET ((tree)*slot);
4323     }
4324   else
4325     /* Our caller will assign and record (in t) a new alias set; all we need
4326        to do is remember t in the hash table.  */
4327     *slot = t;
4328
4329   return -1;
4330 }
4331 \f
4332 /* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where
4333    the second parameter indicates which OPERATOR is being applied.
4334    The COMPLAIN flag controls whether we should diagnose possibly
4335    ill-formed constructs or not.  LOC is the location of the SIZEOF or
4336    TYPEOF operator.  */
4337
4338 tree
4339 c_sizeof_or_alignof_type (location_t loc,
4340                           tree type, bool is_sizeof, int complain)
4341 {
4342   const char *op_name;
4343   tree value = NULL;
4344   enum tree_code type_code = TREE_CODE (type);
4345
4346   op_name = is_sizeof ? "sizeof" : "__alignof__";
4347
4348   if (type_code == FUNCTION_TYPE)
4349     {
4350       if (is_sizeof)
4351         {
4352           if (complain && (pedantic || warn_pointer_arith))
4353             pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
4354                      "invalid application of %<sizeof%> to a function type");
4355           else if (!complain)
4356             return error_mark_node;
4357           value = size_one_node;
4358         }
4359       else
4360         value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);
4361     }
4362   else if (type_code == VOID_TYPE || type_code == ERROR_MARK)
4363     {
4364       if (type_code == VOID_TYPE
4365           && complain && (pedantic || warn_pointer_arith))
4366         pedwarn (loc, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
4367                  "invalid application of %qs to a void type", op_name);
4368       else if (!complain)
4369         return error_mark_node;
4370       value = size_one_node;
4371     }
4372   else if (!COMPLETE_TYPE_P (type))
4373     {
4374       if (complain)
4375         error_at (loc, "invalid application of %qs to incomplete type %qT ",
4376                   op_name, type);
4377       value = size_zero_node;
4378     }
4379   else
4380     {
4381       if (is_sizeof)
4382         /* Convert in case a char is more than one unit.  */
4383         value = size_binop_loc (loc, CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
4384                                 size_int (TYPE_PRECISION (char_type_node)
4385                                           / BITS_PER_UNIT));
4386       else
4387         value = size_int (TYPE_ALIGN_UNIT (type));
4388     }
4389
4390   /* VALUE will have an integer type with TYPE_IS_SIZETYPE set.
4391      TYPE_IS_SIZETYPE means that certain things (like overflow) will
4392      never happen.  However, this node should really have type
4393      `size_t', which is just a typedef for an ordinary integer type.  */
4394   value = fold_convert_loc (loc, size_type_node, value);
4395   gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value)));
4396
4397   return value;
4398 }
4399
4400 /* Implement the __alignof keyword: Return the minimum required
4401    alignment of EXPR, measured in bytes.  For VAR_DECLs,
4402    FUNCTION_DECLs and FIELD_DECLs return DECL_ALIGN (which can be set
4403    from an "aligned" __attribute__ specification).  LOC is the
4404    location of the ALIGNOF operator.  */
4405
4406 tree
4407 c_alignof_expr (location_t loc, tree expr)
4408 {
4409   tree t;
4410
4411   if (VAR_OR_FUNCTION_DECL_P (expr))
4412     t = size_int (DECL_ALIGN_UNIT (expr));
4413
4414   else if (TREE_CODE (expr) == COMPONENT_REF
4415            && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1)))
4416     {
4417       error_at (loc, "%<__alignof%> applied to a bit-field");
4418       t = size_one_node;
4419     }
4420   else if (TREE_CODE (expr) == COMPONENT_REF
4421            && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL)
4422     t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1)));
4423
4424   else if (TREE_CODE (expr) == INDIRECT_REF)
4425     {
4426       tree t = TREE_OPERAND (expr, 0);
4427       tree best = t;
4428       int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
4429
4430       while (CONVERT_EXPR_P (t)
4431              && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE)
4432         {
4433           int thisalign;
4434
4435           t = TREE_OPERAND (t, 0);
4436           thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
4437           if (thisalign > bestalign)
4438             best = t, bestalign = thisalign;
4439         }
4440       return c_alignof (loc, TREE_TYPE (TREE_TYPE (best)));
4441     }
4442   else
4443     return c_alignof (loc, TREE_TYPE (expr));
4444
4445   return fold_convert_loc (loc, size_type_node, t);
4446 }
4447 \f
4448 /* Handle C and C++ default attributes.  */
4449
4450 enum built_in_attribute
4451 {
4452 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
4453 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
4454 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
4455 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
4456 #include "builtin-attrs.def"
4457 #undef DEF_ATTR_NULL_TREE
4458 #undef DEF_ATTR_INT
4459 #undef DEF_ATTR_IDENT
4460 #undef DEF_ATTR_TREE_LIST
4461   ATTR_LAST
4462 };
4463
4464 static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
4465
4466 static void c_init_attributes (void);
4467
4468 enum c_builtin_type
4469 {
4470 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
4471 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
4472 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
4473 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
4474 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
4475 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
4476 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
4477 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) NAME,
4478 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7) NAME,
4479 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
4480 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
4481 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
4482 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
4483 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
4484 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \
4485   NAME,
4486 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
4487 #include "builtin-types.def"
4488 #undef DEF_PRIMITIVE_TYPE
4489 #undef DEF_FUNCTION_TYPE_0
4490 #undef DEF_FUNCTION_TYPE_1
4491 #undef DEF_FUNCTION_TYPE_2
4492 #undef DEF_FUNCTION_TYPE_3
4493 #undef DEF_FUNCTION_TYPE_4
4494 #undef DEF_FUNCTION_TYPE_5
4495 #undef DEF_FUNCTION_TYPE_6
4496 #undef DEF_FUNCTION_TYPE_7
4497 #undef DEF_FUNCTION_TYPE_VAR_0
4498 #undef DEF_FUNCTION_TYPE_VAR_1
4499 #undef DEF_FUNCTION_TYPE_VAR_2
4500 #undef DEF_FUNCTION_TYPE_VAR_3
4501 #undef DEF_FUNCTION_TYPE_VAR_4
4502 #undef DEF_FUNCTION_TYPE_VAR_5
4503 #undef DEF_POINTER_TYPE
4504   BT_LAST
4505 };
4506
4507 typedef enum c_builtin_type builtin_type;
4508
4509 /* A temporary array for c_common_nodes_and_builtins.  Used in
4510    communication with def_fn_type.  */
4511 static tree builtin_types[(int) BT_LAST + 1];
4512
4513 /* A helper function for c_common_nodes_and_builtins.  Build function type
4514    for DEF with return type RET and N arguments.  If VAR is true, then the
4515    function should be variadic after those N arguments.
4516
4517    Takes special care not to ICE if any of the types involved are
4518    error_mark_node, which indicates that said type is not in fact available
4519    (see builtin_type_for_size).  In which case the function type as a whole
4520    should be error_mark_node.  */
4521
4522 static void
4523 def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...)
4524 {
4525   tree args = NULL, t;
4526   va_list list;
4527   int i;
4528
4529   va_start (list, n);
4530   for (i = 0; i < n; ++i)
4531     {
4532       builtin_type a = (builtin_type) va_arg (list, int);
4533       t = builtin_types[a];
4534       if (t == error_mark_node)
4535         goto egress;
4536       args = tree_cons (NULL_TREE, t, args);
4537     }
4538   va_end (list);
4539
4540   args = nreverse (args);
4541   if (!var)
4542     args = chainon (args, void_list_node);
4543
4544   t = builtin_types[ret];
4545   if (t == error_mark_node)
4546     goto egress;
4547   t = build_function_type (t, args);
4548
4549  egress:
4550   builtin_types[def] = t;
4551 }
4552
4553 /* Build builtin functions common to both C and C++ language
4554    frontends.  */
4555
4556 static void
4557 c_define_builtins (tree va_list_ref_type_node, tree va_list_arg_type_node)
4558 {
4559 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
4560   builtin_types[ENUM] = VALUE;
4561 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
4562   def_fn_type (ENUM, RETURN, 0, 0);
4563 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
4564   def_fn_type (ENUM, RETURN, 0, 1, ARG1);
4565 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
4566   def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
4567 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
4568   def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
4569 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
4570   def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
4571 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
4572   def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
4573 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
4574                             ARG6)                                       \
4575   def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
4576 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
4577                             ARG6, ARG7)                                 \
4578   def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
4579 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
4580   def_fn_type (ENUM, RETURN, 1, 0);
4581 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
4582   def_fn_type (ENUM, RETURN, 1, 1, ARG1);
4583 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
4584   def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
4585 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
4586   def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
4587 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
4588   def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
4589 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
4590   def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
4591 #define DEF_POINTER_TYPE(ENUM, TYPE) \
4592   builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
4593
4594 #include "builtin-types.def"
4595
4596 #undef DEF_PRIMITIVE_TYPE
4597 #undef DEF_FUNCTION_TYPE_1
4598 #undef DEF_FUNCTION_TYPE_2
4599 #undef DEF_FUNCTION_TYPE_3
4600 #undef DEF_FUNCTION_TYPE_4
4601 #undef DEF_FUNCTION_TYPE_5
4602 #undef DEF_FUNCTION_TYPE_6
4603 #undef DEF_FUNCTION_TYPE_VAR_0
4604 #undef DEF_FUNCTION_TYPE_VAR_1
4605 #undef DEF_FUNCTION_TYPE_VAR_2
4606 #undef DEF_FUNCTION_TYPE_VAR_3
4607 #undef DEF_FUNCTION_TYPE_VAR_4
4608 #undef DEF_FUNCTION_TYPE_VAR_5
4609 #undef DEF_POINTER_TYPE
4610   builtin_types[(int) BT_LAST] = NULL_TREE;
4611
4612   c_init_attributes ();
4613
4614 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
4615                     NONANSI_P, ATTRS, IMPLICIT, COND)                   \
4616   if (NAME && COND)                                                     \
4617     def_builtin_1 (ENUM, NAME, CLASS,                                   \
4618                    builtin_types[(int) TYPE],                           \
4619                    builtin_types[(int) LIBTYPE],                        \
4620                    BOTH_P, FALLBACK_P, NONANSI_P,                       \
4621                    built_in_attributes[(int) ATTRS], IMPLICIT);
4622 #include "builtins.def"
4623 #undef DEF_BUILTIN
4624
4625   targetm.init_builtins ();
4626
4627   build_common_builtin_nodes ();
4628
4629   if (flag_mudflap)
4630     mudflap_init ();
4631 }
4632
4633 /* Like get_identifier, but avoid warnings about null arguments when
4634    the argument may be NULL for targets where GCC lacks stdint.h type
4635    information.  */
4636
4637 static inline tree
4638 c_get_ident (const char *id)
4639 {
4640   return get_identifier (id);
4641 }
4642
4643 /* Build tree nodes and builtin functions common to both C and C++ language
4644    frontends.  */
4645
4646 void
4647 c_common_nodes_and_builtins (void)
4648 {
4649   int char16_type_size;
4650   int char32_type_size;
4651   int wchar_type_size;
4652   tree array_domain_type;
4653   tree va_list_ref_type_node;
4654   tree va_list_arg_type_node;
4655
4656   /* Define `int' and `char' first so that dbx will output them first.  */
4657   record_builtin_type (RID_INT, NULL, integer_type_node);
4658   record_builtin_type (RID_CHAR, "char", char_type_node);
4659
4660   /* `signed' is the same as `int'.  FIXME: the declarations of "signed",
4661      "unsigned long", "long long unsigned" and "unsigned short" were in C++
4662      but not C.  Are the conditionals here needed?  */
4663   if (c_dialect_cxx ())
4664     record_builtin_type (RID_SIGNED, NULL, integer_type_node);
4665   record_builtin_type (RID_LONG, "long int", long_integer_type_node);
4666   record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
4667   record_builtin_type (RID_MAX, "long unsigned int",
4668                        long_unsigned_type_node);
4669   if (c_dialect_cxx ())
4670     record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
4671   record_builtin_type (RID_MAX, "long long int",
4672                        long_long_integer_type_node);
4673   record_builtin_type (RID_MAX, "long long unsigned int",
4674                        long_long_unsigned_type_node);
4675   if (c_dialect_cxx ())
4676     record_builtin_type (RID_MAX, "long long unsigned",
4677                          long_long_unsigned_type_node);
4678   record_builtin_type (RID_SHORT, "short int", short_integer_type_node);
4679   record_builtin_type (RID_MAX, "short unsigned int",
4680                        short_unsigned_type_node);
4681   if (c_dialect_cxx ())
4682     record_builtin_type (RID_MAX, "unsigned short",
4683                          short_unsigned_type_node);
4684
4685   /* Define both `signed char' and `unsigned char'.  */
4686   record_builtin_type (RID_MAX, "signed char", signed_char_type_node);
4687   record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node);
4688
4689   /* These are types that c_common_type_for_size and
4690      c_common_type_for_mode use.  */
4691   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4692                                          TYPE_DECL, NULL_TREE,
4693                                          intQI_type_node));
4694   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4695                                          TYPE_DECL, NULL_TREE,
4696                                          intHI_type_node));
4697   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4698                                          TYPE_DECL, NULL_TREE,
4699                                          intSI_type_node));
4700   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4701                                          TYPE_DECL, NULL_TREE,
4702                                          intDI_type_node));
4703 #if HOST_BITS_PER_WIDE_INT >= 64
4704   if (targetm.scalar_mode_supported_p (TImode))
4705     lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4706                                            TYPE_DECL,
4707                                            get_identifier ("__int128_t"),
4708                                            intTI_type_node));
4709 #endif
4710   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4711                                          TYPE_DECL, NULL_TREE,
4712                                          unsigned_intQI_type_node));
4713   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4714                                          TYPE_DECL, NULL_TREE,
4715                                          unsigned_intHI_type_node));
4716   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4717                                          TYPE_DECL, NULL_TREE,
4718                                          unsigned_intSI_type_node));
4719   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4720                                          TYPE_DECL, NULL_TREE,
4721                                          unsigned_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 ("__uint128_t"),
4727                                            unsigned_intTI_type_node));
4728 #endif
4729
4730   /* Create the widest literal types.  */
4731   widest_integer_literal_type_node
4732     = make_signed_type (HOST_BITS_PER_WIDE_INT * 2);
4733   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4734                                          TYPE_DECL, NULL_TREE,
4735                                          widest_integer_literal_type_node));
4736
4737   widest_unsigned_literal_type_node
4738     = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2);
4739   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4740                                          TYPE_DECL, NULL_TREE,
4741                                          widest_unsigned_literal_type_node));
4742
4743   /* `unsigned long' is the standard type for sizeof.
4744      Note that stddef.h uses `unsigned long',
4745      and this must agree, even if long and int are the same size.  */
4746   size_type_node =
4747     TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE)));
4748   signed_size_type_node = c_common_signed_type (size_type_node);
4749   set_sizetype (size_type_node);
4750
4751   pid_type_node =
4752     TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE)));
4753
4754   build_common_tree_nodes_2 (flag_short_double);
4755
4756   record_builtin_type (RID_FLOAT, NULL, float_type_node);
4757   record_builtin_type (RID_DOUBLE, NULL, double_type_node);
4758   record_builtin_type (RID_MAX, "long double", long_double_type_node);
4759
4760   /* Only supported decimal floating point extension if the target
4761      actually supports underlying modes. */
4762   if (targetm.scalar_mode_supported_p (SDmode)
4763       && targetm.scalar_mode_supported_p (DDmode)
4764       && targetm.scalar_mode_supported_p (TDmode))
4765     {
4766       record_builtin_type (RID_DFLOAT32, NULL, dfloat32_type_node);
4767       record_builtin_type (RID_DFLOAT64, NULL, dfloat64_type_node);
4768       record_builtin_type (RID_DFLOAT128, NULL, dfloat128_type_node);
4769     }
4770
4771   if (targetm.fixed_point_supported_p ())
4772     {
4773       record_builtin_type (RID_MAX, "short _Fract", short_fract_type_node);
4774       record_builtin_type (RID_FRACT, NULL, fract_type_node);
4775       record_builtin_type (RID_MAX, "long _Fract", long_fract_type_node);
4776       record_builtin_type (RID_MAX, "long long _Fract",
4777                            long_long_fract_type_node);
4778       record_builtin_type (RID_MAX, "unsigned short _Fract",
4779                            unsigned_short_fract_type_node);
4780       record_builtin_type (RID_MAX, "unsigned _Fract",
4781                            unsigned_fract_type_node);
4782       record_builtin_type (RID_MAX, "unsigned long _Fract",
4783                            unsigned_long_fract_type_node);
4784       record_builtin_type (RID_MAX, "unsigned long long _Fract",
4785                            unsigned_long_long_fract_type_node);
4786       record_builtin_type (RID_MAX, "_Sat short _Fract",
4787                            sat_short_fract_type_node);
4788       record_builtin_type (RID_MAX, "_Sat _Fract", sat_fract_type_node);
4789       record_builtin_type (RID_MAX, "_Sat long _Fract",
4790                            sat_long_fract_type_node);
4791       record_builtin_type (RID_MAX, "_Sat long long _Fract",
4792                            sat_long_long_fract_type_node);
4793       record_builtin_type (RID_MAX, "_Sat unsigned short _Fract",
4794                            sat_unsigned_short_fract_type_node);
4795       record_builtin_type (RID_MAX, "_Sat unsigned _Fract",
4796                            sat_unsigned_fract_type_node);
4797       record_builtin_type (RID_MAX, "_Sat unsigned long _Fract",
4798                            sat_unsigned_long_fract_type_node);
4799       record_builtin_type (RID_MAX, "_Sat unsigned long long _Fract",
4800                            sat_unsigned_long_long_fract_type_node);
4801       record_builtin_type (RID_MAX, "short _Accum", short_accum_type_node);
4802       record_builtin_type (RID_ACCUM, NULL, accum_type_node);
4803       record_builtin_type (RID_MAX, "long _Accum", long_accum_type_node);
4804       record_builtin_type (RID_MAX, "long long _Accum",
4805                            long_long_accum_type_node);
4806       record_builtin_type (RID_MAX, "unsigned short _Accum",
4807                            unsigned_short_accum_type_node);
4808       record_builtin_type (RID_MAX, "unsigned _Accum",
4809                            unsigned_accum_type_node);
4810       record_builtin_type (RID_MAX, "unsigned long _Accum",
4811                            unsigned_long_accum_type_node);
4812       record_builtin_type (RID_MAX, "unsigned long long _Accum",
4813                            unsigned_long_long_accum_type_node);
4814       record_builtin_type (RID_MAX, "_Sat short _Accum",
4815                            sat_short_accum_type_node);
4816       record_builtin_type (RID_MAX, "_Sat _Accum", sat_accum_type_node);
4817       record_builtin_type (RID_MAX, "_Sat long _Accum",
4818                            sat_long_accum_type_node);
4819       record_builtin_type (RID_MAX, "_Sat long long _Accum",
4820                           sat_long_long_accum_type_node);
4821       record_builtin_type (RID_MAX, "_Sat unsigned short _Accum",
4822                            sat_unsigned_short_accum_type_node);
4823       record_builtin_type (RID_MAX, "_Sat unsigned _Accum",
4824                            sat_unsigned_accum_type_node);
4825       record_builtin_type (RID_MAX, "_Sat unsigned long _Accum",
4826                            sat_unsigned_long_accum_type_node);
4827       record_builtin_type (RID_MAX, "_Sat unsigned long long _Accum",
4828                            sat_unsigned_long_long_accum_type_node);
4829
4830     }
4831
4832   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4833                                          TYPE_DECL,
4834                                          get_identifier ("complex int"),
4835                                          complex_integer_type_node));
4836   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4837                                          TYPE_DECL,
4838                                          get_identifier ("complex float"),
4839                                          complex_float_type_node));
4840   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
4841                                          TYPE_DECL,
4842                                          get_identifier ("complex double"),
4843                                          complex_double_type_node));
4844   lang_hooks.decls.pushdecl
4845     (build_decl (UNKNOWN_LOCATION,
4846                  TYPE_DECL, get_identifier ("complex long double"),
4847                  complex_long_double_type_node));
4848
4849   if (c_dialect_cxx ())
4850     /* For C++, make fileptr_type_node a distinct void * type until
4851        FILE type is defined.  */
4852     fileptr_type_node = build_variant_type_copy (ptr_type_node);
4853
4854   record_builtin_type (RID_VOID, NULL, void_type_node);
4855
4856   /* Set the TYPE_NAME for any variants that were built before
4857      record_builtin_type gave names to the built-in types. */
4858   {
4859     tree void_name = TYPE_NAME (void_type_node);
4860     TYPE_NAME (void_type_node) = NULL_TREE;
4861     TYPE_NAME (build_qualified_type (void_type_node, TYPE_QUAL_CONST))
4862       = void_name;
4863     TYPE_NAME (void_type_node) = void_name;
4864   }
4865
4866   /* This node must not be shared.  */
4867   void_zero_node = make_node (INTEGER_CST);
4868   TREE_TYPE (void_zero_node) = void_type_node;
4869
4870   void_list_node = build_void_list_node ();
4871
4872   /* Make a type to be the domain of a few array types
4873      whose domains don't really matter.
4874      200 is small enough that it always fits in size_t
4875      and large enough that it can hold most function names for the
4876      initializations of __FUNCTION__ and __PRETTY_FUNCTION__.  */
4877   array_domain_type = build_index_type (size_int (200));
4878
4879   /* Make a type for arrays of characters.
4880      With luck nothing will ever really depend on the length of this
4881      array type.  */
4882   char_array_type_node
4883     = build_array_type (char_type_node, array_domain_type);
4884
4885   /* Likewise for arrays of ints.  */
4886   int_array_type_node
4887     = build_array_type (integer_type_node, array_domain_type);
4888
4889   string_type_node = build_pointer_type (char_type_node);
4890   const_string_type_node
4891     = build_pointer_type (build_qualified_type
4892                           (char_type_node, TYPE_QUAL_CONST));
4893
4894   /* This is special for C++ so functions can be overloaded.  */
4895   wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE);
4896   wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node));
4897   wchar_type_size = TYPE_PRECISION (wchar_type_node);
4898   underlying_wchar_type_node = wchar_type_node;
4899   if (c_dialect_cxx ())
4900     {
4901       if (TYPE_UNSIGNED (wchar_type_node))
4902         wchar_type_node = make_unsigned_type (wchar_type_size);
4903       else
4904         wchar_type_node = make_signed_type (wchar_type_size);
4905       record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node);
4906     }
4907
4908   /* This is for wide string constants.  */
4909   wchar_array_type_node
4910     = build_array_type (wchar_type_node, array_domain_type);
4911
4912   /* Define 'char16_t'.  */
4913   char16_type_node = get_identifier (CHAR16_TYPE);
4914   char16_type_node = TREE_TYPE (identifier_global_value (char16_type_node));
4915   char16_type_size = TYPE_PRECISION (char16_type_node);
4916   if (c_dialect_cxx ())
4917     {
4918       char16_type_node = make_unsigned_type (char16_type_size);
4919
4920       if (cxx_dialect == cxx0x)
4921         record_builtin_type (RID_CHAR16, "char16_t", char16_type_node);
4922     }
4923
4924   /* This is for UTF-16 string constants.  */
4925   char16_array_type_node
4926     = build_array_type (char16_type_node, array_domain_type);
4927
4928   /* Define 'char32_t'.  */
4929   char32_type_node = get_identifier (CHAR32_TYPE);
4930   char32_type_node = TREE_TYPE (identifier_global_value (char32_type_node));
4931   char32_type_size = TYPE_PRECISION (char32_type_node);
4932   if (c_dialect_cxx ())
4933     {
4934       char32_type_node = make_unsigned_type (char32_type_size);
4935
4936       if (cxx_dialect == cxx0x)
4937         record_builtin_type (RID_CHAR32, "char32_t", char32_type_node);
4938     }
4939
4940   /* This is for UTF-32 string constants.  */
4941   char32_array_type_node
4942     = build_array_type (char32_type_node, array_domain_type);
4943
4944   wint_type_node =
4945     TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE)));
4946
4947   intmax_type_node =
4948     TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE)));
4949   uintmax_type_node =
4950     TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE)));
4951
4952   if (SIG_ATOMIC_TYPE)
4953     sig_atomic_type_node =
4954       TREE_TYPE (identifier_global_value (c_get_ident (SIG_ATOMIC_TYPE)));
4955   if (INT8_TYPE)
4956     int8_type_node =
4957       TREE_TYPE (identifier_global_value (c_get_ident (INT8_TYPE)));
4958   if (INT16_TYPE)
4959     int16_type_node =
4960       TREE_TYPE (identifier_global_value (c_get_ident (INT16_TYPE)));
4961   if (INT32_TYPE)
4962     int32_type_node =
4963       TREE_TYPE (identifier_global_value (c_get_ident (INT32_TYPE)));
4964   if (INT64_TYPE)
4965     int64_type_node =
4966       TREE_TYPE (identifier_global_value (c_get_ident (INT64_TYPE)));
4967   if (UINT8_TYPE)
4968     uint8_type_node =
4969       TREE_TYPE (identifier_global_value (c_get_ident (UINT8_TYPE)));
4970   if (UINT16_TYPE)
4971     uint16_type_node =
4972       TREE_TYPE (identifier_global_value (c_get_ident (UINT16_TYPE)));
4973   if (UINT32_TYPE)
4974     c_uint32_type_node =
4975       TREE_TYPE (identifier_global_value (c_get_ident (UINT32_TYPE)));
4976   if (UINT64_TYPE)
4977     c_uint64_type_node =
4978       TREE_TYPE (identifier_global_value (c_get_ident (UINT64_TYPE)));
4979   if (INT_LEAST8_TYPE)
4980     int_least8_type_node =
4981       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST8_TYPE)));
4982   if (INT_LEAST16_TYPE)
4983     int_least16_type_node =
4984       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST16_TYPE)));
4985   if (INT_LEAST32_TYPE)
4986     int_least32_type_node =
4987       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST32_TYPE)));
4988   if (INT_LEAST64_TYPE)
4989     int_least64_type_node =
4990       TREE_TYPE (identifier_global_value (c_get_ident (INT_LEAST64_TYPE)));
4991   if (UINT_LEAST8_TYPE)
4992     uint_least8_type_node =
4993       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST8_TYPE)));
4994   if (UINT_LEAST16_TYPE)
4995     uint_least16_type_node =
4996       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST16_TYPE)));
4997   if (UINT_LEAST32_TYPE)
4998     uint_least32_type_node =
4999       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST32_TYPE)));
5000   if (UINT_LEAST64_TYPE)
5001     uint_least64_type_node =
5002       TREE_TYPE (identifier_global_value (c_get_ident (UINT_LEAST64_TYPE)));
5003   if (INT_FAST8_TYPE)
5004     int_fast8_type_node =
5005       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST8_TYPE)));
5006   if (INT_FAST16_TYPE)
5007     int_fast16_type_node =
5008       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST16_TYPE)));
5009   if (INT_FAST32_TYPE)
5010     int_fast32_type_node =
5011       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST32_TYPE)));
5012   if (INT_FAST64_TYPE)
5013     int_fast64_type_node =
5014       TREE_TYPE (identifier_global_value (c_get_ident (INT_FAST64_TYPE)));
5015   if (UINT_FAST8_TYPE)
5016     uint_fast8_type_node =
5017       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST8_TYPE)));
5018   if (UINT_FAST16_TYPE)
5019     uint_fast16_type_node =
5020       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST16_TYPE)));
5021   if (UINT_FAST32_TYPE)
5022     uint_fast32_type_node =
5023       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST32_TYPE)));
5024   if (UINT_FAST64_TYPE)
5025     uint_fast64_type_node =
5026       TREE_TYPE (identifier_global_value (c_get_ident (UINT_FAST64_TYPE)));
5027   if (INTPTR_TYPE)
5028     intptr_type_node =
5029       TREE_TYPE (identifier_global_value (c_get_ident (INTPTR_TYPE)));
5030   if (UINTPTR_TYPE)
5031     uintptr_type_node =
5032       TREE_TYPE (identifier_global_value (c_get_ident (UINTPTR_TYPE)));
5033
5034   default_function_type = build_function_type (integer_type_node, NULL_TREE);
5035   ptrdiff_type_node
5036     = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE)));
5037   unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node);
5038
5039   lang_hooks.decls.pushdecl
5040     (build_decl (UNKNOWN_LOCATION,
5041                  TYPE_DECL, get_identifier ("__builtin_va_list"),
5042                  va_list_type_node));
5043 #ifdef TARGET_ENUM_VA_LIST
5044   {
5045     int l;
5046     const char *pname;
5047     tree ptype;
5048     for (l = 0; TARGET_ENUM_VA_LIST (l, &pname, &ptype); ++l)
5049       {
5050         lang_hooks.decls.pushdecl
5051           (build_decl (UNKNOWN_LOCATION,
5052                        TYPE_DECL, get_identifier (pname),
5053                        ptype));
5054
5055       }
5056   }
5057 #endif
5058
5059   if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
5060     {
5061       va_list_arg_type_node = va_list_ref_type_node =
5062         build_pointer_type (TREE_TYPE (va_list_type_node));
5063     }
5064   else
5065     {
5066       va_list_arg_type_node = va_list_type_node;
5067       va_list_ref_type_node = build_reference_type (va_list_type_node);
5068     }
5069
5070   if (!flag_preprocess_only)
5071     c_define_builtins (va_list_ref_type_node, va_list_arg_type_node);
5072
5073   main_identifier_node = get_identifier ("main");
5074
5075   /* Create the built-in __null node.  It is important that this is
5076      not shared.  */
5077   null_node = make_node (INTEGER_CST);
5078   TREE_TYPE (null_node) = c_common_type_for_size (POINTER_SIZE, 0);
5079
5080   /* Since builtin_types isn't gc'ed, don't export these nodes.  */
5081   memset (builtin_types, 0, sizeof (builtin_types));
5082 }
5083
5084 /* The number of named compound-literals generated thus far.  */
5085 static GTY(()) int compound_literal_number;
5086
5087 /* Set DECL_NAME for DECL, a VAR_DECL for a compound-literal.  */
5088
5089 void
5090 set_compound_literal_name (tree decl)
5091 {
5092   char *name;
5093   ASM_FORMAT_PRIVATE_NAME (name, "__compound_literal",
5094                            compound_literal_number);
5095   compound_literal_number++;
5096   DECL_NAME (decl) = get_identifier (name);
5097 }
5098
5099 tree
5100 build_va_arg (location_t loc, tree expr, tree type)
5101 {
5102   expr = build1 (VA_ARG_EXPR, type, expr);
5103   SET_EXPR_LOCATION (expr, loc);
5104   return expr;
5105 }
5106
5107
5108 /* Linked list of disabled built-in functions.  */
5109
5110 typedef struct disabled_builtin
5111 {
5112   const char *name;
5113   struct disabled_builtin *next;
5114 } disabled_builtin;
5115 static disabled_builtin *disabled_builtins = NULL;
5116
5117 static bool builtin_function_disabled_p (const char *);
5118
5119 /* Disable a built-in function specified by -fno-builtin-NAME.  If NAME
5120    begins with "__builtin_", give an error.  */
5121
5122 void
5123 disable_builtin_function (const char *name)
5124 {
5125   if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
5126     error ("cannot disable built-in function %qs", name);
5127   else
5128     {
5129       disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin);
5130       new_disabled_builtin->name = name;
5131       new_disabled_builtin->next = disabled_builtins;
5132       disabled_builtins = new_disabled_builtin;
5133     }
5134 }
5135
5136
5137 /* Return true if the built-in function NAME has been disabled, false
5138    otherwise.  */
5139
5140 static bool
5141 builtin_function_disabled_p (const char *name)
5142 {
5143   disabled_builtin *p;
5144   for (p = disabled_builtins; p != NULL; p = p->next)
5145     {
5146       if (strcmp (name, p->name) == 0)
5147         return true;
5148     }
5149   return false;
5150 }
5151
5152
5153 /* Worker for DEF_BUILTIN.
5154    Possibly define a builtin function with one or two names.
5155    Does not declare a non-__builtin_ function if flag_no_builtin, or if
5156    nonansi_p and flag_no_nonansi_builtin.  */
5157
5158 static void
5159 def_builtin_1 (enum built_in_function fncode,
5160                const char *name,
5161                enum built_in_class fnclass,
5162                tree fntype, tree libtype,
5163                bool both_p, bool fallback_p, bool nonansi_p,
5164                tree fnattrs, bool implicit_p)
5165 {
5166   tree decl;
5167   const char *libname;
5168
5169   if (fntype == error_mark_node)
5170     return;
5171
5172   gcc_assert ((!both_p && !fallback_p)
5173               || !strncmp (name, "__builtin_",
5174                            strlen ("__builtin_")));
5175
5176   libname = name + strlen ("__builtin_");
5177   decl = add_builtin_function (name, fntype, fncode, fnclass,
5178                                (fallback_p ? libname : NULL),
5179                                fnattrs);
5180   if (both_p
5181       && !flag_no_builtin && !builtin_function_disabled_p (libname)
5182       && !(nonansi_p && flag_no_nonansi_builtin))
5183     add_builtin_function (libname, libtype, fncode, fnclass,
5184                           NULL, fnattrs);
5185
5186   built_in_decls[(int) fncode] = decl;
5187   if (implicit_p)
5188     implicit_built_in_decls[(int) fncode] = decl;
5189 }
5190 \f
5191 /* Nonzero if the type T promotes to int.  This is (nearly) the
5192    integral promotions defined in ISO C99 6.3.1.1/2.  */
5193
5194 bool
5195 c_promoting_integer_type_p (const_tree t)
5196 {
5197   switch (TREE_CODE (t))
5198     {
5199     case INTEGER_TYPE:
5200       return (TYPE_MAIN_VARIANT (t) == char_type_node
5201               || TYPE_MAIN_VARIANT (t) == signed_char_type_node
5202               || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node
5203               || TYPE_MAIN_VARIANT (t) == short_integer_type_node
5204               || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node
5205               || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node));
5206
5207     case ENUMERAL_TYPE:
5208       /* ??? Technically all enumerations not larger than an int
5209          promote to an int.  But this is used along code paths
5210          that only want to notice a size change.  */
5211       return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node);
5212
5213     case BOOLEAN_TYPE:
5214       return 1;
5215
5216     default:
5217       return 0;
5218     }
5219 }
5220
5221 /* Return 1 if PARMS specifies a fixed number of parameters
5222    and none of their types is affected by default promotions.  */
5223
5224 int
5225 self_promoting_args_p (const_tree parms)
5226 {
5227   const_tree t;
5228   for (t = parms; t; t = TREE_CHAIN (t))
5229     {
5230       tree type = TREE_VALUE (t);
5231
5232       if (type == error_mark_node)
5233         continue;
5234
5235       if (TREE_CHAIN (t) == 0 && type != void_type_node)
5236         return 0;
5237
5238       if (type == 0)
5239         return 0;
5240
5241       if (TYPE_MAIN_VARIANT (type) == float_type_node)
5242         return 0;
5243
5244       if (c_promoting_integer_type_p (type))
5245         return 0;
5246     }
5247   return 1;
5248 }
5249
5250 /* Recursively remove any '*' or '&' operator from TYPE.  */
5251 tree
5252 strip_pointer_operator (tree t)
5253 {
5254   while (POINTER_TYPE_P (t))
5255     t = TREE_TYPE (t);
5256   return t;
5257 }
5258
5259 /* Recursively remove pointer or array type from TYPE. */
5260 tree
5261 strip_pointer_or_array_types (tree t)
5262 {
5263   while (TREE_CODE (t) == ARRAY_TYPE || POINTER_TYPE_P (t))
5264     t = TREE_TYPE (t);
5265   return t;
5266 }
5267
5268 /* Used to compare case labels.  K1 and K2 are actually tree nodes
5269    representing case labels, or NULL_TREE for a `default' label.
5270    Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
5271    K2, and 0 if K1 and K2 are equal.  */
5272
5273 int
5274 case_compare (splay_tree_key k1, splay_tree_key k2)
5275 {
5276   /* Consider a NULL key (such as arises with a `default' label) to be
5277      smaller than anything else.  */
5278   if (!k1)
5279     return k2 ? -1 : 0;
5280   else if (!k2)
5281     return k1 ? 1 : 0;
5282
5283   return tree_int_cst_compare ((tree) k1, (tree) k2);
5284 }
5285
5286 /* Process a case label, located at LOC, for the range LOW_VALUE
5287    ... HIGH_VALUE.  If LOW_VALUE and HIGH_VALUE are both NULL_TREE
5288    then this case label is actually a `default' label.  If only
5289    HIGH_VALUE is NULL_TREE, then case label was declared using the
5290    usual C/C++ syntax, rather than the GNU case range extension.
5291    CASES is a tree containing all the case ranges processed so far;
5292    COND is the condition for the switch-statement itself.  Returns the
5293    CASE_LABEL_EXPR created, or ERROR_MARK_NODE if no CASE_LABEL_EXPR
5294    is created.  */
5295
5296 tree
5297 c_add_case_label (location_t loc, splay_tree cases, tree cond, tree orig_type,
5298                   tree low_value, tree high_value)
5299 {
5300   tree type;
5301   tree label;
5302   tree case_label;
5303   splay_tree_node node;
5304
5305   /* Create the LABEL_DECL itself.  */
5306   label = create_artificial_label (loc);
5307
5308   /* If there was an error processing the switch condition, bail now
5309      before we get more confused.  */
5310   if (!cond || cond == error_mark_node)
5311     goto error_out;
5312
5313   if ((low_value && TREE_TYPE (low_value)
5314        && POINTER_TYPE_P (TREE_TYPE (low_value)))
5315       || (high_value && TREE_TYPE (high_value)
5316           && POINTER_TYPE_P (TREE_TYPE (high_value))))
5317     {
5318       error_at (loc, "pointers are not permitted as case values");
5319       goto error_out;
5320     }
5321
5322   /* Case ranges are a GNU extension.  */
5323   if (high_value)
5324     pedwarn (loc, OPT_pedantic,
5325              "range expressions in switch statements are non-standard");
5326
5327   type = TREE_TYPE (cond);
5328   if (low_value)
5329     {
5330       low_value = check_case_value (low_value);
5331       low_value = convert_and_check (type, low_value);
5332       if (low_value == error_mark_node)
5333         goto error_out;
5334     }
5335   if (high_value)
5336     {
5337       high_value = check_case_value (high_value);
5338       high_value = convert_and_check (type, high_value);
5339       if (high_value == error_mark_node)
5340         goto error_out;
5341     }
5342
5343   if (low_value && high_value)
5344     {
5345       /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
5346          really a case range, even though it was written that way.
5347          Remove the HIGH_VALUE to simplify later processing.  */
5348       if (tree_int_cst_equal (low_value, high_value))
5349         high_value = NULL_TREE;
5350       else if (!tree_int_cst_lt (low_value, high_value))
5351         warning_at (loc, 0, "empty range specified");
5352     }
5353
5354   /* See if the case is in range of the type of the original testing
5355      expression.  If both low_value and high_value are out of range,
5356      don't insert the case label and return NULL_TREE.  */
5357   if (low_value
5358       && !check_case_bounds (type, orig_type,
5359                              &low_value, high_value ? &high_value : NULL))
5360     return NULL_TREE;
5361
5362   /* Look up the LOW_VALUE in the table of case labels we already
5363      have.  */
5364   node = splay_tree_lookup (cases, (splay_tree_key) low_value);
5365   /* If there was not an exact match, check for overlapping ranges.
5366      There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
5367      that's a `default' label and the only overlap is an exact match.  */
5368   if (!node && (low_value || high_value))
5369     {
5370       splay_tree_node low_bound;
5371       splay_tree_node high_bound;
5372
5373       /* Even though there wasn't an exact match, there might be an
5374          overlap between this case range and another case range.
5375          Since we've (inductively) not allowed any overlapping case
5376          ranges, we simply need to find the greatest low case label
5377          that is smaller that LOW_VALUE, and the smallest low case
5378          label that is greater than LOW_VALUE.  If there is an overlap
5379          it will occur in one of these two ranges.  */
5380       low_bound = splay_tree_predecessor (cases,
5381                                           (splay_tree_key) low_value);
5382       high_bound = splay_tree_successor (cases,
5383                                          (splay_tree_key) low_value);
5384
5385       /* Check to see if the LOW_BOUND overlaps.  It is smaller than
5386          the LOW_VALUE, so there is no need to check unless the
5387          LOW_BOUND is in fact itself a case range.  */
5388       if (low_bound
5389           && CASE_HIGH ((tree) low_bound->value)
5390           && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
5391                                     low_value) >= 0)
5392         node = low_bound;
5393       /* Check to see if the HIGH_BOUND overlaps.  The low end of that
5394          range is bigger than the low end of the current range, so we
5395          are only interested if the current range is a real range, and
5396          not an ordinary case label.  */
5397       else if (high_bound
5398                && high_value
5399                && (tree_int_cst_compare ((tree) high_bound->key,
5400                                          high_value)
5401                    <= 0))
5402         node = high_bound;
5403     }
5404   /* If there was an overlap, issue an error.  */
5405   if (node)
5406     {
5407       tree duplicate = CASE_LABEL ((tree) node->value);
5408
5409       if (high_value)
5410         {
5411           error_at (loc, "duplicate (or overlapping) case value");
5412           error_at (DECL_SOURCE_LOCATION (duplicate),
5413                     "this is the first entry overlapping that value");
5414         }
5415       else if (low_value)
5416         {
5417           error_at (loc, "duplicate case value") ;
5418           error_at (DECL_SOURCE_LOCATION (duplicate), "previously used here");
5419         }
5420       else
5421         {
5422           error_at (loc, "multiple default labels in one switch");
5423           error_at (DECL_SOURCE_LOCATION (duplicate),
5424                     "this is the first default label");
5425         }
5426       goto error_out;
5427     }
5428
5429   /* Add a CASE_LABEL to the statement-tree.  */
5430   case_label = add_stmt (build_case_label (loc, low_value, high_value, label));
5431   /* Register this case label in the splay tree.  */
5432   splay_tree_insert (cases,
5433                      (splay_tree_key) low_value,
5434                      (splay_tree_value) case_label);
5435
5436   return case_label;
5437
5438  error_out:
5439   /* Add a label so that the back-end doesn't think that the beginning of
5440      the switch is unreachable.  Note that we do not add a case label, as
5441      that just leads to duplicates and thence to failure later on.  */
5442   if (!cases->root)
5443     {
5444       tree t = create_artificial_label (loc);
5445       add_stmt (build_stmt (loc, LABEL_EXPR, t));
5446     }
5447   return error_mark_node;
5448 }
5449
5450 /* Subroutines of c_do_switch_warnings, called via splay_tree_foreach.
5451    Used to verify that case values match up with enumerator values.  */
5452
5453 static void
5454 match_case_to_enum_1 (tree key, tree type, tree label)
5455 {
5456   char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1];
5457
5458   /* ??? Not working too hard to print the double-word value.
5459      Should perhaps be done with %lwd in the diagnostic routines?  */
5460   if (TREE_INT_CST_HIGH (key) == 0)
5461     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED,
5462               TREE_INT_CST_LOW (key));
5463   else if (!TYPE_UNSIGNED (type)
5464            && TREE_INT_CST_HIGH (key) == -1
5465            && TREE_INT_CST_LOW (key) != 0)
5466     snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED,
5467               -TREE_INT_CST_LOW (key));
5468   else
5469     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX,
5470               (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (key),
5471               (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (key));
5472
5473   if (TYPE_NAME (type) == 0)
5474     warning_at (DECL_SOURCE_LOCATION (CASE_LABEL (label)),
5475                 warn_switch ? OPT_Wswitch : OPT_Wswitch_enum,
5476                 "case value %qs not in enumerated type",
5477                 buf);
5478   else
5479     warning_at (DECL_SOURCE_LOCATION (CASE_LABEL (label)),
5480                 warn_switch ? OPT_Wswitch : OPT_Wswitch_enum,
5481                 "case value %qs not in enumerated type %qT",
5482                 buf, type);
5483 }
5484
5485 /* Subroutine of c_do_switch_warnings, called via splay_tree_foreach.
5486    Used to verify that case values match up with enumerator values.  */
5487
5488 static int
5489 match_case_to_enum (splay_tree_node node, void *data)
5490 {
5491   tree label = (tree) node->value;
5492   tree type = (tree) data;
5493
5494   /* Skip default case.  */
5495   if (!CASE_LOW (label))
5496     return 0;
5497
5498   /* If CASE_LOW_SEEN is not set, that means CASE_LOW did not appear
5499      when we did our enum->case scan.  Reset our scratch bit after.  */
5500   if (!CASE_LOW_SEEN (label))
5501     match_case_to_enum_1 (CASE_LOW (label), type, label);
5502   else
5503     CASE_LOW_SEEN (label) = 0;
5504
5505   /* If CASE_HIGH is non-null, we have a range.  If CASE_HIGH_SEEN is
5506      not set, that means that CASE_HIGH did not appear when we did our
5507      enum->case scan.  Reset our scratch bit after.  */
5508   if (CASE_HIGH (label))
5509     {
5510       if (!CASE_HIGH_SEEN (label))
5511         match_case_to_enum_1 (CASE_HIGH (label), type, label);
5512       else
5513         CASE_HIGH_SEEN (label) = 0;
5514     }
5515
5516   return 0;
5517 }
5518
5519 /* Handle -Wswitch*.  Called from the front end after parsing the
5520    switch construct.  */
5521 /* ??? Should probably be somewhere generic, since other languages
5522    besides C and C++ would want this.  At the moment, however, C/C++
5523    are the only tree-ssa languages that support enumerations at all,
5524    so the point is moot.  */
5525
5526 void
5527 c_do_switch_warnings (splay_tree cases, location_t switch_location,
5528                       tree type, tree cond)
5529 {
5530   splay_tree_node default_node;
5531   splay_tree_node node;
5532   tree chain;
5533
5534   if (!warn_switch && !warn_switch_enum && !warn_switch_default)
5535     return;
5536
5537   default_node = splay_tree_lookup (cases, (splay_tree_key) NULL);
5538   if (!default_node)
5539     warning_at (switch_location, OPT_Wswitch_default,
5540                 "switch missing default case");
5541
5542   /* From here on, we only care about about enumerated types.  */
5543   if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
5544     return;
5545
5546   /* From here on, we only care about -Wswitch and -Wswitch-enum.  */
5547   if (!warn_switch_enum && !warn_switch)
5548     return;
5549
5550   /* Check the cases.  Warn about case values which are not members of
5551      the enumerated type.  For -Wswitch-enum, or for -Wswitch when
5552      there is no default case, check that exactly all enumeration
5553      literals are covered by the cases.  */
5554
5555   /* Clearing COND if it is not an integer constant simplifies
5556      the tests inside the loop below.  */
5557   if (TREE_CODE (cond) != INTEGER_CST)
5558     cond = NULL_TREE;
5559
5560   /* The time complexity here is O(N*lg(N)) worst case, but for the
5561       common case of monotonically increasing enumerators, it is
5562       O(N), since the nature of the splay tree will keep the next
5563       element adjacent to the root at all times.  */
5564
5565   for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain))
5566     {
5567       tree value = TREE_VALUE (chain);
5568       if (TREE_CODE (value) == CONST_DECL)
5569         value = DECL_INITIAL (value);
5570       node = splay_tree_lookup (cases, (splay_tree_key) value);
5571       if (node)
5572         {
5573           /* Mark the CASE_LOW part of the case entry as seen.  */
5574           tree label = (tree) node->value;
5575           CASE_LOW_SEEN (label) = 1;
5576           continue;
5577         }
5578
5579       /* Even though there wasn't an exact match, there might be a
5580          case range which includes the enumerator's value.  */
5581       node = splay_tree_predecessor (cases, (splay_tree_key) value);
5582       if (node && CASE_HIGH ((tree) node->value))
5583         {
5584           tree label = (tree) node->value;
5585           int cmp = tree_int_cst_compare (CASE_HIGH (label), value);
5586           if (cmp >= 0)
5587             {
5588               /* If we match the upper bound exactly, mark the CASE_HIGH
5589                  part of the case entry as seen.  */
5590               if (cmp == 0)
5591                 CASE_HIGH_SEEN (label) = 1;
5592               continue;
5593             }
5594         }
5595
5596       /* We've now determined that this enumerated literal isn't
5597          handled by the case labels of the switch statement.  */
5598
5599       /* If the switch expression is a constant, we only really care
5600          about whether that constant is handled by the switch.  */
5601       if (cond && tree_int_cst_compare (cond, value))
5602         continue;
5603
5604       /* If there is a default_node, the only relevant option is
5605          Wswitch-enum.  Otherwise, if both are enabled then we prefer
5606          to warn using -Wswitch because -Wswitch is enabled by -Wall
5607          while -Wswitch-enum is explicit.  */
5608       warning_at (switch_location,
5609                   (default_node || !warn_switch
5610                    ? OPT_Wswitch_enum
5611                    : OPT_Wswitch),
5612                   "enumeration value %qE not handled in switch",
5613                   TREE_PURPOSE (chain));
5614     }
5615
5616   /* Warn if there are case expressions that don't correspond to
5617      enumerators.  This can occur since C and C++ don't enforce
5618      type-checking of assignments to enumeration variables.
5619
5620      The time complexity here is now always O(N) worst case, since
5621      we should have marked both the lower bound and upper bound of
5622      every disjoint case label, with CASE_LOW_SEEN and CASE_HIGH_SEEN
5623      above.  This scan also resets those fields.  */
5624
5625   splay_tree_foreach (cases, match_case_to_enum, type);
5626 }
5627
5628 /* Finish an expression taking the address of LABEL (an
5629    IDENTIFIER_NODE).  Returns an expression for the address.
5630
5631    LOC is the location for the expression returned.  */
5632
5633 tree
5634 finish_label_address_expr (tree label, location_t loc)
5635 {
5636   tree result;
5637
5638   pedwarn (input_location, OPT_pedantic, "taking the address of a label is non-standard");
5639
5640   if (label == error_mark_node)
5641     return error_mark_node;
5642
5643   label = lookup_label (label);
5644   if (label == NULL_TREE)
5645     result = null_pointer_node;
5646   else
5647     {
5648       TREE_USED (label) = 1;
5649       result = build1 (ADDR_EXPR, ptr_type_node, label);
5650       /* The current function is not necessarily uninlinable.
5651          Computed gotos are incompatible with inlining, but the value
5652          here could be used only in a diagnostic, for example.  */
5653       protected_set_expr_location (result, loc);
5654     }
5655
5656   return result;
5657 }
5658 \f
5659
5660 /* Given a boolean expression ARG, return a tree representing an increment
5661    or decrement (as indicated by CODE) of ARG.  The front end must check for
5662    invalid cases (e.g., decrement in C++).  */
5663 tree
5664 boolean_increment (enum tree_code code, tree arg)
5665 {
5666   tree val;
5667   tree true_res = build_int_cst (TREE_TYPE (arg), 1);
5668
5669   arg = stabilize_reference (arg);
5670   switch (code)
5671     {
5672     case PREINCREMENT_EXPR:
5673       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
5674       break;
5675     case POSTINCREMENT_EXPR:
5676       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
5677       arg = save_expr (arg);
5678       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
5679       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
5680       break;
5681     case PREDECREMENT_EXPR:
5682       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
5683                     invert_truthvalue_loc (input_location, arg));
5684       break;
5685     case POSTDECREMENT_EXPR:
5686       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
5687                     invert_truthvalue_loc (input_location, arg));
5688       arg = save_expr (arg);
5689       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
5690       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
5691       break;
5692     default:
5693       gcc_unreachable ();
5694     }
5695   TREE_SIDE_EFFECTS (val) = 1;
5696   return val;
5697 }
5698 \f
5699 /* Built-in macros for stddef.h and stdint.h, that require macros
5700    defined in this file.  */
5701 void
5702 c_stddef_cpp_builtins(void)
5703 {
5704   builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0);
5705   builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0);
5706   builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0);
5707   builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0);
5708   builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0);
5709   builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0);
5710   builtin_define_with_value ("__CHAR16_TYPE__", CHAR16_TYPE, 0);
5711   builtin_define_with_value ("__CHAR32_TYPE__", CHAR32_TYPE, 0);
5712   if (SIG_ATOMIC_TYPE)
5713     builtin_define_with_value ("__SIG_ATOMIC_TYPE__", SIG_ATOMIC_TYPE, 0);
5714   if (INT8_TYPE)
5715     builtin_define_with_value ("__INT8_TYPE__", INT8_TYPE, 0);
5716   if (INT16_TYPE)
5717     builtin_define_with_value ("__INT16_TYPE__", INT16_TYPE, 0);
5718   if (INT32_TYPE)
5719     builtin_define_with_value ("__INT32_TYPE__", INT32_TYPE, 0);
5720   if (INT64_TYPE)
5721     builtin_define_with_value ("__INT64_TYPE__", INT64_TYPE, 0);
5722   if (UINT8_TYPE)
5723     builtin_define_with_value ("__UINT8_TYPE__", UINT8_TYPE, 0);
5724   if (UINT16_TYPE)
5725     builtin_define_with_value ("__UINT16_TYPE__", UINT16_TYPE, 0);
5726   if (UINT32_TYPE)
5727     builtin_define_with_value ("__UINT32_TYPE__", UINT32_TYPE, 0);
5728   if (UINT64_TYPE)
5729     builtin_define_with_value ("__UINT64_TYPE__", UINT64_TYPE, 0);
5730   if (INT_LEAST8_TYPE)
5731     builtin_define_with_value ("__INT_LEAST8_TYPE__", INT_LEAST8_TYPE, 0);
5732   if (INT_LEAST16_TYPE)
5733     builtin_define_with_value ("__INT_LEAST16_TYPE__", INT_LEAST16_TYPE, 0);
5734   if (INT_LEAST32_TYPE)
5735     builtin_define_with_value ("__INT_LEAST32_TYPE__", INT_LEAST32_TYPE, 0);
5736   if (INT_LEAST64_TYPE)
5737     builtin_define_with_value ("__INT_LEAST64_TYPE__", INT_LEAST64_TYPE, 0);
5738   if (UINT_LEAST8_TYPE)
5739     builtin_define_with_value ("__UINT_LEAST8_TYPE__", UINT_LEAST8_TYPE, 0);
5740   if (UINT_LEAST16_TYPE)
5741     builtin_define_with_value ("__UINT_LEAST16_TYPE__", UINT_LEAST16_TYPE, 0);
5742   if (UINT_LEAST32_TYPE)
5743     builtin_define_with_value ("__UINT_LEAST32_TYPE__", UINT_LEAST32_TYPE, 0);
5744   if (UINT_LEAST64_TYPE)
5745     builtin_define_with_value ("__UINT_LEAST64_TYPE__", UINT_LEAST64_TYPE, 0);
5746   if (INT_FAST8_TYPE)
5747     builtin_define_with_value ("__INT_FAST8_TYPE__", INT_FAST8_TYPE, 0);
5748   if (INT_FAST16_TYPE)
5749     builtin_define_with_value ("__INT_FAST16_TYPE__", INT_FAST16_TYPE, 0);
5750   if (INT_FAST32_TYPE)
5751     builtin_define_with_value ("__INT_FAST32_TYPE__", INT_FAST32_TYPE, 0);
5752   if (INT_FAST64_TYPE)
5753     builtin_define_with_value ("__INT_FAST64_TYPE__", INT_FAST64_TYPE, 0);
5754   if (UINT_FAST8_TYPE)
5755     builtin_define_with_value ("__UINT_FAST8_TYPE__", UINT_FAST8_TYPE, 0);
5756   if (UINT_FAST16_TYPE)
5757     builtin_define_with_value ("__UINT_FAST16_TYPE__", UINT_FAST16_TYPE, 0);
5758   if (UINT_FAST32_TYPE)
5759     builtin_define_with_value ("__UINT_FAST32_TYPE__", UINT_FAST32_TYPE, 0);
5760   if (UINT_FAST64_TYPE)
5761     builtin_define_with_value ("__UINT_FAST64_TYPE__", UINT_FAST64_TYPE, 0);
5762   if (INTPTR_TYPE)
5763     builtin_define_with_value ("__INTPTR_TYPE__", INTPTR_TYPE, 0);
5764   if (UINTPTR_TYPE)
5765     builtin_define_with_value ("__UINTPTR_TYPE__", UINTPTR_TYPE, 0);
5766 }
5767
5768 static void
5769 c_init_attributes (void)
5770 {
5771   /* Fill in the built_in_attributes array.  */
5772 #define DEF_ATTR_NULL_TREE(ENUM)                                \
5773   built_in_attributes[(int) ENUM] = NULL_TREE;
5774 #define DEF_ATTR_INT(ENUM, VALUE)                               \
5775   built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
5776 #define DEF_ATTR_IDENT(ENUM, STRING)                            \
5777   built_in_attributes[(int) ENUM] = get_identifier (STRING);
5778 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
5779   built_in_attributes[(int) ENUM]                       \
5780     = tree_cons (built_in_attributes[(int) PURPOSE],    \
5781                  built_in_attributes[(int) VALUE],      \
5782                  built_in_attributes[(int) CHAIN]);
5783 #include "builtin-attrs.def"
5784 #undef DEF_ATTR_NULL_TREE
5785 #undef DEF_ATTR_INT
5786 #undef DEF_ATTR_IDENT
5787 #undef DEF_ATTR_TREE_LIST
5788 }
5789
5790 /* Attribute handlers common to C front ends.  */
5791
5792 /* Handle a "packed" attribute; arguments as in
5793    struct attribute_spec.handler.  */
5794
5795 static tree
5796 handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5797                          int flags, bool *no_add_attrs)
5798 {
5799   if (TYPE_P (*node))
5800     {
5801       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5802         *node = build_variant_type_copy (*node);
5803       TYPE_PACKED (*node) = 1;
5804     }
5805   else if (TREE_CODE (*node) == FIELD_DECL)
5806     {
5807       if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT
5808           /* Still pack bitfields.  */
5809           && ! DECL_INITIAL (*node))
5810         warning (OPT_Wattributes,
5811                  "%qE attribute ignored for field of type %qT",
5812                  name, TREE_TYPE (*node));
5813       else
5814         DECL_PACKED (*node) = 1;
5815     }
5816   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
5817      used for DECL_REGISTER.  It wouldn't mean anything anyway.
5818      We can't set DECL_PACKED on the type of a TYPE_DECL, because
5819      that changes what the typedef is typing.  */
5820   else
5821     {
5822       warning (OPT_Wattributes, "%qE attribute ignored", name);
5823       *no_add_attrs = true;
5824     }
5825
5826   return NULL_TREE;
5827 }
5828
5829 /* Handle a "nocommon" attribute; arguments as in
5830    struct attribute_spec.handler.  */
5831
5832 static tree
5833 handle_nocommon_attribute (tree *node, tree name,
5834                            tree ARG_UNUSED (args),
5835                            int ARG_UNUSED (flags), bool *no_add_attrs)
5836 {
5837   if (TREE_CODE (*node) == VAR_DECL)
5838     DECL_COMMON (*node) = 0;
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 "common" attribute; arguments as in
5849    struct attribute_spec.handler.  */
5850
5851 static tree
5852 handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5853                          int ARG_UNUSED (flags), bool *no_add_attrs)
5854 {
5855   if (TREE_CODE (*node) == VAR_DECL)
5856     DECL_COMMON (*node) = 1;
5857   else
5858     {
5859       warning (OPT_Wattributes, "%qE attribute ignored", name);
5860       *no_add_attrs = true;
5861     }
5862
5863   return NULL_TREE;
5864 }
5865
5866 /* Handle a "noreturn" attribute; arguments as in
5867    struct attribute_spec.handler.  */
5868
5869 static tree
5870 handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5871                            int ARG_UNUSED (flags), bool *no_add_attrs)
5872 {
5873   tree type = TREE_TYPE (*node);
5874
5875   /* See FIXME comment in c_common_attribute_table.  */
5876   if (TREE_CODE (*node) == FUNCTION_DECL)
5877     TREE_THIS_VOLATILE (*node) = 1;
5878   else if (TREE_CODE (type) == POINTER_TYPE
5879            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
5880     TREE_TYPE (*node)
5881       = build_pointer_type
5882         (build_type_variant (TREE_TYPE (type),
5883                              TYPE_READONLY (TREE_TYPE (type)), 1));
5884   else
5885     {
5886       warning (OPT_Wattributes, "%qE attribute ignored", name);
5887       *no_add_attrs = true;
5888     }
5889
5890   return NULL_TREE;
5891 }
5892
5893 /* Handle a "hot" and attribute; arguments as in
5894    struct attribute_spec.handler.  */
5895
5896 static tree
5897 handle_hot_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5898                       int ARG_UNUSED (flags), bool *no_add_attrs)
5899 {
5900   if (TREE_CODE (*node) == FUNCTION_DECL)
5901     {
5902       if (lookup_attribute ("cold", DECL_ATTRIBUTES (*node)) != NULL)
5903         {
5904           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
5905                    name, "cold");
5906           *no_add_attrs = true;
5907         }
5908       /* Most of the rest of the hot processing is done later with
5909          lookup_attribute.  */
5910     }
5911   else
5912     {
5913       warning (OPT_Wattributes, "%qE attribute ignored", name);
5914       *no_add_attrs = true;
5915     }
5916
5917   return NULL_TREE;
5918 }
5919 /* Handle a "cold" and attribute; arguments as in
5920    struct attribute_spec.handler.  */
5921
5922 static tree
5923 handle_cold_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5924                        int ARG_UNUSED (flags), bool *no_add_attrs)
5925 {
5926   if (TREE_CODE (*node) == FUNCTION_DECL)
5927     {
5928       if (lookup_attribute ("hot", DECL_ATTRIBUTES (*node)) != NULL)
5929         {
5930           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
5931                    name, "hot");
5932           *no_add_attrs = true;
5933         }
5934       /* Most of the rest of the cold processing is done later with
5935          lookup_attribute.  */
5936     }
5937   else
5938     {
5939       warning (OPT_Wattributes, "%qE attribute ignored", name);
5940       *no_add_attrs = true;
5941     }
5942
5943   return NULL_TREE;
5944 }
5945
5946 /* Handle a "noinline" attribute; arguments as in
5947    struct attribute_spec.handler.  */
5948
5949 static tree
5950 handle_noinline_attribute (tree *node, tree name,
5951                            tree ARG_UNUSED (args),
5952                            int ARG_UNUSED (flags), bool *no_add_attrs)
5953 {
5954   if (TREE_CODE (*node) == FUNCTION_DECL)
5955     DECL_UNINLINABLE (*node) = 1;
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 "noclone" attribute; arguments as in
5966    struct attribute_spec.handler.  */
5967
5968 static tree
5969 handle_noclone_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     {
5975       warning (OPT_Wattributes, "%qE attribute ignored", name);
5976       *no_add_attrs = true;
5977     }
5978
5979   return NULL_TREE;
5980 }
5981
5982 /* Handle a "always_inline" attribute; arguments as in
5983    struct attribute_spec.handler.  */
5984
5985 static tree
5986 handle_always_inline_attribute (tree *node, tree name,
5987                                 tree ARG_UNUSED (args),
5988                                 int ARG_UNUSED (flags),
5989                                 bool *no_add_attrs)
5990 {
5991   if (TREE_CODE (*node) == FUNCTION_DECL)
5992     {
5993       /* Set the attribute and mark it for disregarding inline
5994          limits.  */
5995       DECL_DISREGARD_INLINE_LIMITS (*node) = 1;
5996     }
5997   else
5998     {
5999       warning (OPT_Wattributes, "%qE attribute ignored", name);
6000       *no_add_attrs = true;
6001     }
6002
6003   return NULL_TREE;
6004 }
6005
6006 /* Handle a "gnu_inline" attribute; arguments as in
6007    struct attribute_spec.handler.  */
6008
6009 static tree
6010 handle_gnu_inline_attribute (tree *node, tree name,
6011                              tree ARG_UNUSED (args),
6012                              int ARG_UNUSED (flags),
6013                              bool *no_add_attrs)
6014 {
6015   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
6016     {
6017       /* Do nothing else, just set the attribute.  We'll get at
6018          it later with lookup_attribute.  */
6019     }
6020   else
6021     {
6022       warning (OPT_Wattributes, "%qE attribute ignored", name);
6023       *no_add_attrs = true;
6024     }
6025
6026   return NULL_TREE;
6027 }
6028
6029 /* Handle an "artificial" attribute; arguments as in
6030    struct attribute_spec.handler.  */
6031
6032 static tree
6033 handle_artificial_attribute (tree *node, tree name,
6034                              tree ARG_UNUSED (args),
6035                              int ARG_UNUSED (flags),
6036                              bool *no_add_attrs)
6037 {
6038   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
6039     {
6040       /* Do nothing else, just set the attribute.  We'll get at
6041          it later with lookup_attribute.  */
6042     }
6043   else
6044     {
6045       warning (OPT_Wattributes, "%qE attribute ignored", name);
6046       *no_add_attrs = true;
6047     }
6048
6049   return NULL_TREE;
6050 }
6051
6052 /* Handle a "flatten" attribute; arguments as in
6053    struct attribute_spec.handler.  */
6054
6055 static tree
6056 handle_flatten_attribute (tree *node, tree name,
6057                           tree args ATTRIBUTE_UNUSED,
6058                           int flags ATTRIBUTE_UNUSED, bool *no_add_attrs)
6059 {
6060   if (TREE_CODE (*node) == FUNCTION_DECL)
6061     /* Do nothing else, just set the attribute.  We'll get at
6062        it later with lookup_attribute.  */
6063     ;
6064   else
6065     {
6066       warning (OPT_Wattributes, "%qE attribute ignored", name);
6067       *no_add_attrs = true;
6068     }
6069
6070   return NULL_TREE;
6071 }
6072
6073 /* Handle a "warning" or "error" attribute; arguments as in
6074    struct attribute_spec.handler.  */
6075
6076 static tree
6077 handle_error_attribute (tree *node, tree name, tree args,
6078                         int ARG_UNUSED (flags), bool *no_add_attrs)
6079 {
6080   if (TREE_CODE (*node) == FUNCTION_DECL
6081       || TREE_CODE (TREE_VALUE (args)) == STRING_CST)
6082     /* Do nothing else, just set the attribute.  We'll get at
6083        it later with lookup_attribute.  */
6084     ;
6085   else
6086     {
6087       warning (OPT_Wattributes, "%qE attribute ignored", name);
6088       *no_add_attrs = true;
6089     }
6090
6091   return NULL_TREE;
6092 }
6093
6094 /* Handle a "used" attribute; arguments as in
6095    struct attribute_spec.handler.  */
6096
6097 static tree
6098 handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
6099                        int ARG_UNUSED (flags), bool *no_add_attrs)
6100 {
6101   tree node = *pnode;
6102
6103   if (TREE_CODE (node) == FUNCTION_DECL
6104       || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node)))
6105     {
6106       TREE_USED (node) = 1;
6107       DECL_PRESERVE_P (node) = 1;
6108     }
6109   else
6110     {
6111       warning (OPT_Wattributes, "%qE attribute ignored", name);
6112       *no_add_attrs = true;
6113     }
6114
6115   return NULL_TREE;
6116 }
6117
6118 /* Handle a "unused" attribute; arguments as in
6119    struct attribute_spec.handler.  */
6120
6121 static tree
6122 handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6123                          int flags, bool *no_add_attrs)
6124 {
6125   if (DECL_P (*node))
6126     {
6127       tree decl = *node;
6128
6129       if (TREE_CODE (decl) == PARM_DECL
6130           || TREE_CODE (decl) == VAR_DECL
6131           || TREE_CODE (decl) == FUNCTION_DECL
6132           || TREE_CODE (decl) == LABEL_DECL
6133           || TREE_CODE (decl) == TYPE_DECL)
6134         TREE_USED (decl) = 1;
6135       else
6136         {
6137           warning (OPT_Wattributes, "%qE attribute ignored", name);
6138           *no_add_attrs = true;
6139         }
6140     }
6141   else
6142     {
6143       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6144         *node = build_variant_type_copy (*node);
6145       TREE_USED (*node) = 1;
6146     }
6147
6148   return NULL_TREE;
6149 }
6150
6151 /* Handle a "externally_visible" attribute; arguments as in
6152    struct attribute_spec.handler.  */
6153
6154 static tree
6155 handle_externally_visible_attribute (tree *pnode, tree name,
6156                                      tree ARG_UNUSED (args),
6157                                      int ARG_UNUSED (flags),
6158                                      bool *no_add_attrs)
6159 {
6160   tree node = *pnode;
6161
6162   if (TREE_CODE (node) == FUNCTION_DECL || TREE_CODE (node) == VAR_DECL)
6163     {
6164       if ((!TREE_STATIC (node) && TREE_CODE (node) != FUNCTION_DECL
6165            && !DECL_EXTERNAL (node)) || !TREE_PUBLIC (node))
6166         {
6167           warning (OPT_Wattributes,
6168                    "%qE attribute have effect only on public objects", name);
6169           *no_add_attrs = true;
6170         }
6171     }
6172   else
6173     {
6174       warning (OPT_Wattributes, "%qE attribute ignored", name);
6175       *no_add_attrs = true;
6176     }
6177
6178   return NULL_TREE;
6179 }
6180
6181 /* Handle a "const" attribute; arguments as in
6182    struct attribute_spec.handler.  */
6183
6184 static tree
6185 handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6186                         int ARG_UNUSED (flags), bool *no_add_attrs)
6187 {
6188   tree type = TREE_TYPE (*node);
6189
6190   /* See FIXME comment on noreturn in c_common_attribute_table.  */
6191   if (TREE_CODE (*node) == FUNCTION_DECL)
6192     TREE_READONLY (*node) = 1;
6193   else if (TREE_CODE (type) == POINTER_TYPE
6194            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
6195     TREE_TYPE (*node)
6196       = build_pointer_type
6197         (build_type_variant (TREE_TYPE (type), 1,
6198                              TREE_THIS_VOLATILE (TREE_TYPE (type))));
6199   else
6200     {
6201       warning (OPT_Wattributes, "%qE attribute ignored", name);
6202       *no_add_attrs = true;
6203     }
6204
6205   return NULL_TREE;
6206 }
6207
6208 /* Handle a "transparent_union" attribute; arguments as in
6209    struct attribute_spec.handler.  */
6210
6211 static tree
6212 handle_transparent_union_attribute (tree *node, tree name,
6213                                     tree ARG_UNUSED (args), int flags,
6214                                     bool *no_add_attrs)
6215 {
6216   tree type;
6217
6218   *no_add_attrs = true;
6219
6220   if (TREE_CODE (*node) == TYPE_DECL)
6221     node = &TREE_TYPE (*node);
6222   type = *node;
6223
6224   if (TREE_CODE (type) == UNION_TYPE)
6225     {
6226       /* When IN_PLACE is set, leave the check for FIELDS and MODE to
6227          the code in finish_struct.  */
6228       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6229         {
6230           if (TYPE_FIELDS (type) == NULL_TREE
6231               || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type)))
6232             goto ignored;
6233
6234           /* A type variant isn't good enough, since we don't a cast
6235              to such a type removed as a no-op.  */
6236           *node = type = build_duplicate_type (type);
6237         }
6238
6239       TYPE_TRANSPARENT_AGGR (type) = 1;
6240       return NULL_TREE;
6241     }
6242
6243  ignored:
6244   warning (OPT_Wattributes, "%qE attribute ignored", name);
6245   return NULL_TREE;
6246 }
6247
6248 /* Subroutine of handle_{con,de}structor_attribute.  Evaluate ARGS to
6249    get the requested priority for a constructor or destructor,
6250    possibly issuing diagnostics for invalid or reserved
6251    priorities.  */
6252
6253 static priority_type
6254 get_priority (tree args, bool is_destructor)
6255 {
6256   HOST_WIDE_INT pri;
6257   tree arg;
6258
6259   if (!args)
6260     return DEFAULT_INIT_PRIORITY;
6261
6262   if (!SUPPORTS_INIT_PRIORITY)
6263     {
6264       if (is_destructor)
6265         error ("destructor priorities are not supported");
6266       else
6267         error ("constructor priorities are not supported");
6268       return DEFAULT_INIT_PRIORITY;
6269     }
6270
6271   arg = TREE_VALUE (args);
6272   if (!host_integerp (arg, /*pos=*/0)
6273       || !INTEGRAL_TYPE_P (TREE_TYPE (arg)))
6274     goto invalid;
6275
6276   pri = tree_low_cst (TREE_VALUE (args), /*pos=*/0);
6277   if (pri < 0 || pri > MAX_INIT_PRIORITY)
6278     goto invalid;
6279
6280   if (pri <= MAX_RESERVED_INIT_PRIORITY)
6281     {
6282       if (is_destructor)
6283         warning (0,
6284                  "destructor priorities from 0 to %d are reserved "
6285                  "for the implementation",
6286                  MAX_RESERVED_INIT_PRIORITY);
6287       else
6288         warning (0,
6289                  "constructor priorities from 0 to %d are reserved "
6290                  "for the implementation",
6291                  MAX_RESERVED_INIT_PRIORITY);
6292     }
6293   return pri;
6294
6295  invalid:
6296   if (is_destructor)
6297     error ("destructor priorities must be integers from 0 to %d inclusive",
6298            MAX_INIT_PRIORITY);
6299   else
6300     error ("constructor priorities must be integers from 0 to %d inclusive",
6301            MAX_INIT_PRIORITY);
6302   return DEFAULT_INIT_PRIORITY;
6303 }
6304
6305 /* Handle a "constructor" attribute; arguments as in
6306    struct attribute_spec.handler.  */
6307
6308 static tree
6309 handle_constructor_attribute (tree *node, tree name, tree args,
6310                               int ARG_UNUSED (flags),
6311                               bool *no_add_attrs)
6312 {
6313   tree decl = *node;
6314   tree type = TREE_TYPE (decl);
6315
6316   if (TREE_CODE (decl) == FUNCTION_DECL
6317       && TREE_CODE (type) == FUNCTION_TYPE
6318       && decl_function_context (decl) == 0)
6319     {
6320       priority_type priority;
6321       DECL_STATIC_CONSTRUCTOR (decl) = 1;
6322       priority = get_priority (args, /*is_destructor=*/false);
6323       SET_DECL_INIT_PRIORITY (decl, priority);
6324       TREE_USED (decl) = 1;
6325     }
6326   else
6327     {
6328       warning (OPT_Wattributes, "%qE attribute ignored", name);
6329       *no_add_attrs = true;
6330     }
6331
6332   return NULL_TREE;
6333 }
6334
6335 /* Handle a "destructor" attribute; arguments as in
6336    struct attribute_spec.handler.  */
6337
6338 static tree
6339 handle_destructor_attribute (tree *node, tree name, tree args,
6340                              int ARG_UNUSED (flags),
6341                              bool *no_add_attrs)
6342 {
6343   tree decl = *node;
6344   tree type = TREE_TYPE (decl);
6345
6346   if (TREE_CODE (decl) == FUNCTION_DECL
6347       && TREE_CODE (type) == FUNCTION_TYPE
6348       && decl_function_context (decl) == 0)
6349     {
6350       priority_type priority;
6351       DECL_STATIC_DESTRUCTOR (decl) = 1;
6352       priority = get_priority (args, /*is_destructor=*/true);
6353       SET_DECL_FINI_PRIORITY (decl, priority);
6354       TREE_USED (decl) = 1;
6355     }
6356   else
6357     {
6358       warning (OPT_Wattributes, "%qE attribute ignored", name);
6359       *no_add_attrs = true;
6360     }
6361
6362   return NULL_TREE;
6363 }
6364
6365 /* Handle a "mode" attribute; arguments as in
6366    struct attribute_spec.handler.  */
6367
6368 static tree
6369 handle_mode_attribute (tree *node, tree name, tree args,
6370                        int ARG_UNUSED (flags), bool *no_add_attrs)
6371 {
6372   tree type = *node;
6373   tree ident = TREE_VALUE (args);
6374
6375   *no_add_attrs = true;
6376
6377   if (TREE_CODE (ident) != IDENTIFIER_NODE)
6378     warning (OPT_Wattributes, "%qE attribute ignored", name);
6379   else
6380     {
6381       int j;
6382       const char *p = IDENTIFIER_POINTER (ident);
6383       int len = strlen (p);
6384       enum machine_mode mode = VOIDmode;
6385       tree typefm;
6386       bool valid_mode;
6387
6388       if (len > 4 && p[0] == '_' && p[1] == '_'
6389           && p[len - 1] == '_' && p[len - 2] == '_')
6390         {
6391           char *newp = (char *) alloca (len - 1);
6392
6393           strcpy (newp, &p[2]);
6394           newp[len - 4] = '\0';
6395           p = newp;
6396         }
6397
6398       /* Change this type to have a type with the specified mode.
6399          First check for the special modes.  */
6400       if (!strcmp (p, "byte"))
6401         mode = byte_mode;
6402       else if (!strcmp (p, "word"))
6403         mode = word_mode;
6404       else if (!strcmp (p, "pointer"))
6405         mode = ptr_mode;
6406       else if (!strcmp (p, "libgcc_cmp_return"))
6407         mode = targetm.libgcc_cmp_return_mode ();
6408       else if (!strcmp (p, "libgcc_shift_count"))
6409         mode = targetm.libgcc_shift_count_mode ();
6410       else if (!strcmp (p, "unwind_word"))
6411         mode = targetm.unwind_word_mode ();
6412       else
6413         for (j = 0; j < NUM_MACHINE_MODES; j++)
6414           if (!strcmp (p, GET_MODE_NAME (j)))
6415             {
6416               mode = (enum machine_mode) j;
6417               break;
6418             }
6419
6420       if (mode == VOIDmode)
6421         {
6422           error ("unknown machine mode %qE", ident);
6423           return NULL_TREE;
6424         }
6425
6426       valid_mode = false;
6427       switch (GET_MODE_CLASS (mode))
6428         {
6429         case MODE_INT:
6430         case MODE_PARTIAL_INT:
6431         case MODE_FLOAT:
6432         case MODE_DECIMAL_FLOAT:
6433         case MODE_FRACT:
6434         case MODE_UFRACT:
6435         case MODE_ACCUM:
6436         case MODE_UACCUM:
6437           valid_mode = targetm.scalar_mode_supported_p (mode);
6438           break;
6439
6440         case MODE_COMPLEX_INT:
6441         case MODE_COMPLEX_FLOAT:
6442           valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode));
6443           break;
6444
6445         case MODE_VECTOR_INT:
6446         case MODE_VECTOR_FLOAT:
6447         case MODE_VECTOR_FRACT:
6448         case MODE_VECTOR_UFRACT:
6449         case MODE_VECTOR_ACCUM:
6450         case MODE_VECTOR_UACCUM:
6451           warning (OPT_Wattributes, "specifying vector types with "
6452                    "__attribute__ ((mode)) is deprecated");
6453           warning (OPT_Wattributes,
6454                    "use __attribute__ ((vector_size)) instead");
6455           valid_mode = vector_mode_valid_p (mode);
6456           break;
6457
6458         default:
6459           break;
6460         }
6461       if (!valid_mode)
6462         {
6463           error ("unable to emulate %qs", p);
6464           return NULL_TREE;
6465         }
6466
6467       if (POINTER_TYPE_P (type))
6468         {
6469           addr_space_t as = TYPE_ADDR_SPACE (TREE_TYPE (type));
6470           tree (*fn)(tree, enum machine_mode, bool);
6471
6472           if (!targetm.addr_space.valid_pointer_mode (mode, as))
6473             {
6474               error ("invalid pointer mode %qs", p);
6475               return NULL_TREE;
6476             }
6477
6478           if (TREE_CODE (type) == POINTER_TYPE)
6479             fn = build_pointer_type_for_mode;
6480           else
6481             fn = build_reference_type_for_mode;
6482           typefm = fn (TREE_TYPE (type), mode, false);
6483         }
6484       else
6485         {
6486           /* For fixed-point modes, we need to test if the signness of type
6487              and the machine mode are consistent.  */
6488           if (ALL_FIXED_POINT_MODE_P (mode)
6489               && TYPE_UNSIGNED (type) != UNSIGNED_FIXED_POINT_MODE_P (mode))
6490             {
6491               error ("signness of type and machine mode %qs don't match", p);
6492               return NULL_TREE;
6493             }
6494           /* For fixed-point modes, we need to pass saturating info.  */
6495           typefm = lang_hooks.types.type_for_mode (mode,
6496                         ALL_FIXED_POINT_MODE_P (mode) ? TYPE_SATURATING (type)
6497                                                       : TYPE_UNSIGNED (type));
6498         }
6499
6500       if (typefm == NULL_TREE)
6501         {
6502           error ("no data type for mode %qs", p);
6503           return NULL_TREE;
6504         }
6505       else if (TREE_CODE (type) == ENUMERAL_TYPE)
6506         {
6507           /* For enumeral types, copy the precision from the integer
6508              type returned above.  If not an INTEGER_TYPE, we can't use
6509              this mode for this type.  */
6510           if (TREE_CODE (typefm) != INTEGER_TYPE)
6511             {
6512               error ("cannot use mode %qs for enumeral types", p);
6513               return NULL_TREE;
6514             }
6515
6516           if (flags & ATTR_FLAG_TYPE_IN_PLACE)
6517             {
6518               TYPE_PRECISION (type) = TYPE_PRECISION (typefm);
6519               typefm = type;
6520             }
6521           else
6522             {
6523               /* We cannot build a type variant, as there's code that assumes
6524                  that TYPE_MAIN_VARIANT has the same mode.  This includes the
6525                  debug generators.  Instead, create a subrange type.  This
6526                  results in all of the enumeral values being emitted only once
6527                  in the original, and the subtype gets them by reference.  */
6528               if (TYPE_UNSIGNED (type))
6529                 typefm = make_unsigned_type (TYPE_PRECISION (typefm));
6530               else
6531                 typefm = make_signed_type (TYPE_PRECISION (typefm));
6532               TREE_TYPE (typefm) = type;
6533             }
6534         }
6535       else if (VECTOR_MODE_P (mode)
6536                ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm))
6537                : TREE_CODE (type) != TREE_CODE (typefm))
6538         {
6539           error ("mode %qs applied to inappropriate type", p);
6540           return NULL_TREE;
6541         }
6542
6543       *node = typefm;
6544     }
6545
6546   return NULL_TREE;
6547 }
6548
6549 /* Handle a "section" attribute; arguments as in
6550    struct attribute_spec.handler.  */
6551
6552 static tree
6553 handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6554                           int ARG_UNUSED (flags), bool *no_add_attrs)
6555 {
6556   tree decl = *node;
6557
6558   if (targetm.have_named_sections)
6559     {
6560       user_defined_section_attribute = true;
6561
6562       if ((TREE_CODE (decl) == FUNCTION_DECL
6563            || TREE_CODE (decl) == VAR_DECL)
6564           && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
6565         {
6566           if (TREE_CODE (decl) == VAR_DECL
6567               && current_function_decl != NULL_TREE
6568               && !TREE_STATIC (decl))
6569             {
6570               error_at (DECL_SOURCE_LOCATION (decl),
6571                         "section attribute cannot be specified for "
6572                         "local variables");
6573               *no_add_attrs = true;
6574             }
6575
6576           /* The decl may have already been given a section attribute
6577              from a previous declaration.  Ensure they match.  */
6578           else if (DECL_SECTION_NAME (decl) != NULL_TREE
6579                    && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
6580                               TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
6581             {
6582               error ("section of %q+D conflicts with previous declaration",
6583                      *node);
6584               *no_add_attrs = true;
6585             }
6586           else if (TREE_CODE (decl) == VAR_DECL
6587                    && !targetm.have_tls && targetm.emutls.tmpl_section
6588                    && DECL_THREAD_LOCAL_P (decl))
6589             {
6590               error ("section of %q+D cannot be overridden", *node);
6591               *no_add_attrs = true;
6592             }
6593           else
6594             DECL_SECTION_NAME (decl) = TREE_VALUE (args);
6595         }
6596       else
6597         {
6598           error ("section attribute not allowed for %q+D", *node);
6599           *no_add_attrs = true;
6600         }
6601     }
6602   else
6603     {
6604       error_at (DECL_SOURCE_LOCATION (*node),
6605                 "section attributes are not supported for this target");
6606       *no_add_attrs = true;
6607     }
6608
6609   return NULL_TREE;
6610 }
6611
6612 /* Handle a "aligned" attribute; arguments as in
6613    struct attribute_spec.handler.  */
6614
6615 static tree
6616 handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6617                           int flags, bool *no_add_attrs)
6618 {
6619   tree decl = NULL_TREE;
6620   tree *type = NULL;
6621   int is_type = 0;
6622   tree align_expr = (args ? TREE_VALUE (args)
6623                      : size_int (ATTRIBUTE_ALIGNED_VALUE / BITS_PER_UNIT));
6624   int i;
6625
6626   if (DECL_P (*node))
6627     {
6628       decl = *node;
6629       type = &TREE_TYPE (decl);
6630       is_type = TREE_CODE (*node) == TYPE_DECL;
6631     }
6632   else if (TYPE_P (*node))
6633     type = node, is_type = 1;
6634
6635   if (TREE_CODE (align_expr) != INTEGER_CST)
6636     {
6637       error ("requested alignment is not a constant");
6638       *no_add_attrs = true;
6639     }
6640   else if ((i = tree_log2 (align_expr)) == -1)
6641     {
6642       error ("requested alignment is not a power of 2");
6643       *no_add_attrs = true;
6644     }
6645   else if (i >= HOST_BITS_PER_INT - BITS_PER_UNIT_LOG)
6646     {
6647       error ("requested alignment is too large");
6648       *no_add_attrs = true;
6649     }
6650   else if (is_type)
6651     {
6652       if ((flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
6653         /* OK, modify the type in place.  */;
6654       /* If we have a TYPE_DECL, then copy the type, so that we
6655          don't accidentally modify a builtin type.  See pushdecl.  */
6656       else if (decl && TREE_TYPE (decl) != error_mark_node
6657                && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
6658         {
6659           tree tt = TREE_TYPE (decl);
6660           *type = build_variant_type_copy (*type);
6661           DECL_ORIGINAL_TYPE (decl) = tt;
6662           TYPE_NAME (*type) = decl;
6663           TREE_USED (*type) = TREE_USED (decl);
6664           TREE_TYPE (decl) = *type;
6665         }
6666       else
6667         *type = build_variant_type_copy (*type);
6668
6669       TYPE_ALIGN (*type) = (1U << i) * BITS_PER_UNIT;
6670       TYPE_USER_ALIGN (*type) = 1;
6671     }
6672   else if (! VAR_OR_FUNCTION_DECL_P (decl)
6673            && TREE_CODE (decl) != FIELD_DECL)
6674     {
6675       error ("alignment may not be specified for %q+D", decl);
6676       *no_add_attrs = true;
6677     }
6678   else if (TREE_CODE (decl) == FUNCTION_DECL
6679            && DECL_ALIGN (decl) > (1U << i) * BITS_PER_UNIT)
6680     {
6681       if (DECL_USER_ALIGN (decl))
6682         error ("alignment for %q+D was previously specified as %d "
6683                "and may not be decreased", decl,
6684                DECL_ALIGN (decl) / BITS_PER_UNIT);
6685       else
6686         error ("alignment for %q+D must be at least %d", decl,
6687                DECL_ALIGN (decl) / BITS_PER_UNIT);
6688       *no_add_attrs = true;
6689     }
6690   else
6691     {
6692       DECL_ALIGN (decl) = (1U << i) * BITS_PER_UNIT;
6693       DECL_USER_ALIGN (decl) = 1;
6694     }
6695
6696   return NULL_TREE;
6697 }
6698
6699 /* Handle a "weak" attribute; arguments as in
6700    struct attribute_spec.handler.  */
6701
6702 static tree
6703 handle_weak_attribute (tree *node, tree name,
6704                        tree ARG_UNUSED (args),
6705                        int ARG_UNUSED (flags),
6706                        bool * ARG_UNUSED (no_add_attrs))
6707 {
6708   if (TREE_CODE (*node) == FUNCTION_DECL
6709       && DECL_DECLARED_INLINE_P (*node))
6710     {
6711       error ("inline function %q+D cannot be declared weak", *node);
6712       *no_add_attrs = true;
6713     }
6714   else if (TREE_CODE (*node) == FUNCTION_DECL
6715            || TREE_CODE (*node) == VAR_DECL)
6716     declare_weak (*node);
6717   else
6718     warning (OPT_Wattributes, "%qE attribute ignored", name);
6719
6720   return NULL_TREE;
6721 }
6722
6723 /* Handle an "alias" attribute; arguments as in
6724    struct attribute_spec.handler.  */
6725
6726 static tree
6727 handle_alias_attribute (tree *node, tree name, tree args,
6728                         int ARG_UNUSED (flags), bool *no_add_attrs)
6729 {
6730   tree decl = *node;
6731
6732   if (TREE_CODE (decl) != FUNCTION_DECL && TREE_CODE (decl) != VAR_DECL)
6733     {
6734       warning (OPT_Wattributes, "%qE attribute ignored", name);
6735       *no_add_attrs = true;
6736     }
6737   else if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
6738       || (TREE_CODE (decl) != FUNCTION_DECL
6739           && TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl))
6740       /* A static variable declaration is always a tentative definition,
6741          but the alias is a non-tentative definition which overrides.  */
6742       || (TREE_CODE (decl) != FUNCTION_DECL
6743           && ! TREE_PUBLIC (decl) && DECL_INITIAL (decl)))
6744     {
6745       error ("%q+D defined both normally and as an alias", decl);
6746       *no_add_attrs = true;
6747     }
6748
6749   /* Note that the very first time we process a nested declaration,
6750      decl_function_context will not be set.  Indeed, *would* never
6751      be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that
6752      we do below.  After such frobbery, pushdecl would set the context.
6753      In any case, this is never what we want.  */
6754   else if (decl_function_context (decl) == 0 && current_function_decl == NULL)
6755     {
6756       tree id;
6757
6758       id = TREE_VALUE (args);
6759       if (TREE_CODE (id) != STRING_CST)
6760         {
6761           error ("alias argument not a string");
6762           *no_add_attrs = true;
6763           return NULL_TREE;
6764         }
6765       id = get_identifier (TREE_STRING_POINTER (id));
6766       /* This counts as a use of the object pointed to.  */
6767       TREE_USED (id) = 1;
6768
6769       if (TREE_CODE (decl) == FUNCTION_DECL)
6770         DECL_INITIAL (decl) = error_mark_node;
6771       else
6772         {
6773           if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
6774             DECL_EXTERNAL (decl) = 1;
6775           else
6776             DECL_EXTERNAL (decl) = 0;
6777           TREE_STATIC (decl) = 1;
6778         }
6779     }
6780   else
6781     {
6782       warning (OPT_Wattributes, "%qE attribute ignored", name);
6783       *no_add_attrs = true;
6784     }
6785
6786   return NULL_TREE;
6787 }
6788
6789 /* Handle a "weakref" attribute; arguments as in struct
6790    attribute_spec.handler.  */
6791
6792 static tree
6793 handle_weakref_attribute (tree *node, tree ARG_UNUSED (name), tree args,
6794                           int flags, bool *no_add_attrs)
6795 {
6796   tree attr = NULL_TREE;
6797
6798   /* We must ignore the attribute when it is associated with
6799      local-scoped decls, since attribute alias is ignored and many
6800      such symbols do not even have a DECL_WEAK field.  */
6801   if (decl_function_context (*node)
6802       || current_function_decl
6803       || (TREE_CODE (*node) != VAR_DECL && TREE_CODE (*node) != FUNCTION_DECL))
6804     {
6805       warning (OPT_Wattributes, "%qE attribute ignored", name);
6806       *no_add_attrs = true;
6807       return NULL_TREE;
6808     }
6809
6810   /* The idea here is that `weakref("name")' mutates into `weakref,
6811      alias("name")', and weakref without arguments, in turn,
6812      implicitly adds weak. */
6813
6814   if (args)
6815     {
6816       attr = tree_cons (get_identifier ("alias"), args, attr);
6817       attr = tree_cons (get_identifier ("weakref"), NULL_TREE, attr);
6818
6819       *no_add_attrs = true;
6820
6821       decl_attributes (node, attr, flags);
6822     }
6823   else
6824     {
6825       if (lookup_attribute ("alias", DECL_ATTRIBUTES (*node)))
6826         error_at (DECL_SOURCE_LOCATION (*node),
6827                   "weakref attribute must appear before alias attribute");
6828
6829       /* Can't call declare_weak because it wants this to be TREE_PUBLIC,
6830          and that isn't supported; and because it wants to add it to
6831          the list of weak decls, which isn't helpful.  */
6832       DECL_WEAK (*node) = 1;
6833     }
6834
6835   return NULL_TREE;
6836 }
6837
6838 /* Handle an "visibility" attribute; arguments as in
6839    struct attribute_spec.handler.  */
6840
6841 static tree
6842 handle_visibility_attribute (tree *node, tree name, tree args,
6843                              int ARG_UNUSED (flags),
6844                              bool *ARG_UNUSED (no_add_attrs))
6845 {
6846   tree decl = *node;
6847   tree id = TREE_VALUE (args);
6848   enum symbol_visibility vis;
6849
6850   if (TYPE_P (*node))
6851     {
6852       if (TREE_CODE (*node) == ENUMERAL_TYPE)
6853         /* OK */;
6854       else if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE)
6855         {
6856           warning (OPT_Wattributes, "%qE attribute ignored on non-class types",
6857                    name);
6858           return NULL_TREE;
6859         }
6860       else if (TYPE_FIELDS (*node))
6861         {
6862           error ("%qE attribute ignored because %qT is already defined",
6863                  name, *node);
6864           return NULL_TREE;
6865         }
6866     }
6867   else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl))
6868     {
6869       warning (OPT_Wattributes, "%qE attribute ignored", name);
6870       return NULL_TREE;
6871     }
6872
6873   if (TREE_CODE (id) != STRING_CST)
6874     {
6875       error ("visibility argument not a string");
6876       return NULL_TREE;
6877     }
6878
6879   /*  If this is a type, set the visibility on the type decl.  */
6880   if (TYPE_P (decl))
6881     {
6882       decl = TYPE_NAME (decl);
6883       if (!decl)
6884         return NULL_TREE;
6885       if (TREE_CODE (decl) == IDENTIFIER_NODE)
6886         {
6887            warning (OPT_Wattributes, "%qE attribute ignored on types",
6888                     name);
6889            return NULL_TREE;
6890         }
6891     }
6892
6893   if (strcmp (TREE_STRING_POINTER (id), "default") == 0)
6894     vis = VISIBILITY_DEFAULT;
6895   else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0)
6896     vis = VISIBILITY_INTERNAL;
6897   else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0)
6898     vis = VISIBILITY_HIDDEN;
6899   else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0)
6900     vis = VISIBILITY_PROTECTED;
6901   else
6902     {
6903       error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\"");
6904       vis = VISIBILITY_DEFAULT;
6905     }
6906
6907   if (DECL_VISIBILITY_SPECIFIED (decl)
6908       && vis != DECL_VISIBILITY (decl))
6909     {
6910       tree attributes = (TYPE_P (*node)
6911                          ? TYPE_ATTRIBUTES (*node)
6912                          : DECL_ATTRIBUTES (decl));
6913       if (lookup_attribute ("visibility", attributes))
6914         error ("%qD redeclared with different visibility", decl);
6915       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
6916                && lookup_attribute ("dllimport", attributes))
6917         error ("%qD was declared %qs which implies default visibility",
6918                decl, "dllimport");
6919       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
6920                && lookup_attribute ("dllexport", attributes))
6921         error ("%qD was declared %qs which implies default visibility",
6922                decl, "dllexport");
6923     }
6924
6925   DECL_VISIBILITY (decl) = vis;
6926   DECL_VISIBILITY_SPECIFIED (decl) = 1;
6927
6928   /* Go ahead and attach the attribute to the node as well.  This is needed
6929      so we can determine whether we have VISIBILITY_DEFAULT because the
6930      visibility was not specified, or because it was explicitly overridden
6931      from the containing scope.  */
6932
6933   return NULL_TREE;
6934 }
6935
6936 /* Determine the ELF symbol visibility for DECL, which is either a
6937    variable or a function.  It is an error to use this function if a
6938    definition of DECL is not available in this translation unit.
6939    Returns true if the final visibility has been determined by this
6940    function; false if the caller is free to make additional
6941    modifications.  */
6942
6943 bool
6944 c_determine_visibility (tree decl)
6945 {
6946   gcc_assert (TREE_CODE (decl) == VAR_DECL
6947               || TREE_CODE (decl) == FUNCTION_DECL);
6948
6949   /* If the user explicitly specified the visibility with an
6950      attribute, honor that.  DECL_VISIBILITY will have been set during
6951      the processing of the attribute.  We check for an explicit
6952      attribute, rather than just checking DECL_VISIBILITY_SPECIFIED,
6953      to distinguish the use of an attribute from the use of a "#pragma
6954      GCC visibility push(...)"; in the latter case we still want other
6955      considerations to be able to overrule the #pragma.  */
6956   if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl))
6957       || (TARGET_DLLIMPORT_DECL_ATTRIBUTES
6958           && (lookup_attribute ("dllimport", DECL_ATTRIBUTES (decl))
6959               || lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))))
6960     return true;
6961
6962   /* Set default visibility to whatever the user supplied with
6963      visibility_specified depending on #pragma GCC visibility.  */
6964   if (!DECL_VISIBILITY_SPECIFIED (decl))
6965     {
6966       if (visibility_options.inpragma
6967           || DECL_VISIBILITY (decl) != default_visibility)
6968         {
6969           DECL_VISIBILITY (decl) = default_visibility;
6970           DECL_VISIBILITY_SPECIFIED (decl) = visibility_options.inpragma;
6971           /* If visibility changed and DECL already has DECL_RTL, ensure
6972              symbol flags are updated.  */
6973           if (((TREE_CODE (decl) == VAR_DECL && TREE_STATIC (decl))
6974                || TREE_CODE (decl) == FUNCTION_DECL)
6975               && DECL_RTL_SET_P (decl))
6976             make_decl_rtl (decl);
6977         }
6978     }
6979   return false;
6980 }
6981
6982 /* Handle an "tls_model" attribute; arguments as in
6983    struct attribute_spec.handler.  */
6984
6985 static tree
6986 handle_tls_model_attribute (tree *node, tree name, tree args,
6987                             int ARG_UNUSED (flags), bool *no_add_attrs)
6988 {
6989   tree id;
6990   tree decl = *node;
6991   enum tls_model kind;
6992
6993   *no_add_attrs = true;
6994
6995   if (TREE_CODE (decl) != VAR_DECL || !DECL_THREAD_LOCAL_P (decl))
6996     {
6997       warning (OPT_Wattributes, "%qE attribute ignored", name);
6998       return NULL_TREE;
6999     }
7000
7001   kind = DECL_TLS_MODEL (decl);
7002   id = TREE_VALUE (args);
7003   if (TREE_CODE (id) != STRING_CST)
7004     {
7005       error ("tls_model argument not a string");
7006       return NULL_TREE;
7007     }
7008
7009   if (!strcmp (TREE_STRING_POINTER (id), "local-exec"))
7010     kind = TLS_MODEL_LOCAL_EXEC;
7011   else if (!strcmp (TREE_STRING_POINTER (id), "initial-exec"))
7012     kind = TLS_MODEL_INITIAL_EXEC;
7013   else if (!strcmp (TREE_STRING_POINTER (id), "local-dynamic"))
7014     kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
7015   else if (!strcmp (TREE_STRING_POINTER (id), "global-dynamic"))
7016     kind = TLS_MODEL_GLOBAL_DYNAMIC;
7017   else
7018     error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\"");
7019
7020   DECL_TLS_MODEL (decl) = kind;
7021   return NULL_TREE;
7022 }
7023
7024 /* Handle a "no_instrument_function" attribute; arguments as in
7025    struct attribute_spec.handler.  */
7026
7027 static tree
7028 handle_no_instrument_function_attribute (tree *node, tree name,
7029                                          tree ARG_UNUSED (args),
7030                                          int ARG_UNUSED (flags),
7031                                          bool *no_add_attrs)
7032 {
7033   tree decl = *node;
7034
7035   if (TREE_CODE (decl) != FUNCTION_DECL)
7036     {
7037       error_at (DECL_SOURCE_LOCATION (decl),
7038                 "%qE attribute applies only to functions", name);
7039       *no_add_attrs = true;
7040     }
7041   else if (DECL_INITIAL (decl))
7042     {
7043       error_at (DECL_SOURCE_LOCATION (decl),
7044                 "can%'t set %qE attribute after definition", name);
7045       *no_add_attrs = true;
7046     }
7047   else
7048     DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
7049
7050   return NULL_TREE;
7051 }
7052
7053 /* Handle a "malloc" attribute; arguments as in
7054    struct attribute_spec.handler.  */
7055
7056 static tree
7057 handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7058                          int ARG_UNUSED (flags), bool *no_add_attrs)
7059 {
7060   if (TREE_CODE (*node) == FUNCTION_DECL
7061       && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node))))
7062     DECL_IS_MALLOC (*node) = 1;
7063   else
7064     {
7065       warning (OPT_Wattributes, "%qE attribute ignored", name);
7066       *no_add_attrs = true;
7067     }
7068
7069   return NULL_TREE;
7070 }
7071
7072 /* Handle a "alloc_size" attribute; arguments as in
7073    struct attribute_spec.handler.  */
7074
7075 static tree
7076 handle_alloc_size_attribute (tree *node, tree ARG_UNUSED (name), tree args,
7077                              int ARG_UNUSED (flags), bool *no_add_attrs)
7078 {
7079   unsigned arg_count = type_num_arguments (*node);
7080   for (; args; args = TREE_CHAIN (args))
7081     {
7082       tree position = TREE_VALUE (args);
7083
7084       if (TREE_CODE (position) != INTEGER_CST
7085           || TREE_INT_CST_HIGH (position)
7086           || TREE_INT_CST_LOW (position) < 1
7087           || TREE_INT_CST_LOW (position) > arg_count )
7088         {
7089           warning (OPT_Wattributes,
7090                    "alloc_size parameter outside range");
7091           *no_add_attrs = true;
7092           return NULL_TREE;
7093         }
7094     }
7095   return NULL_TREE;
7096 }
7097
7098 /* Handle a "returns_twice" attribute; arguments as in
7099    struct attribute_spec.handler.  */
7100
7101 static tree
7102 handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7103                          int ARG_UNUSED (flags), bool *no_add_attrs)
7104 {
7105   if (TREE_CODE (*node) == FUNCTION_DECL)
7106     DECL_IS_RETURNS_TWICE (*node) = 1;
7107   else
7108     {
7109       warning (OPT_Wattributes, "%qE attribute ignored", name);
7110       *no_add_attrs = true;
7111     }
7112
7113   return NULL_TREE;
7114 }
7115
7116 /* Handle a "no_limit_stack" attribute; arguments as in
7117    struct attribute_spec.handler.  */
7118
7119 static tree
7120 handle_no_limit_stack_attribute (tree *node, tree name,
7121                                  tree ARG_UNUSED (args),
7122                                  int ARG_UNUSED (flags),
7123                                  bool *no_add_attrs)
7124 {
7125   tree decl = *node;
7126
7127   if (TREE_CODE (decl) != FUNCTION_DECL)
7128     {
7129       error_at (DECL_SOURCE_LOCATION (decl),
7130              "%qE attribute applies only to functions", name);
7131       *no_add_attrs = true;
7132     }
7133   else if (DECL_INITIAL (decl))
7134     {
7135       error_at (DECL_SOURCE_LOCATION (decl),
7136                 "can%'t set %qE attribute after definition", name);
7137       *no_add_attrs = true;
7138     }
7139   else
7140     DECL_NO_LIMIT_STACK (decl) = 1;
7141
7142   return NULL_TREE;
7143 }
7144
7145 /* Handle a "pure" attribute; arguments as in
7146    struct attribute_spec.handler.  */
7147
7148 static tree
7149 handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7150                        int ARG_UNUSED (flags), bool *no_add_attrs)
7151 {
7152   if (TREE_CODE (*node) == FUNCTION_DECL)
7153     DECL_PURE_P (*node) = 1;
7154   /* ??? TODO: Support types.  */
7155   else
7156     {
7157       warning (OPT_Wattributes, "%qE attribute ignored", name);
7158       *no_add_attrs = true;
7159     }
7160
7161   return NULL_TREE;
7162 }
7163
7164 /* Handle a "no vops" attribute; arguments as in
7165    struct attribute_spec.handler.  */
7166
7167 static tree
7168 handle_novops_attribute (tree *node, tree ARG_UNUSED (name),
7169                          tree ARG_UNUSED (args), int ARG_UNUSED (flags),
7170                          bool *ARG_UNUSED (no_add_attrs))
7171 {
7172   gcc_assert (TREE_CODE (*node) == FUNCTION_DECL);
7173   DECL_IS_NOVOPS (*node) = 1;
7174   return NULL_TREE;
7175 }
7176
7177 /* Handle a "deprecated" attribute; arguments as in
7178    struct attribute_spec.handler.  */
7179
7180 static tree
7181 handle_deprecated_attribute (tree *node, tree name,
7182                              tree args, int flags,
7183                              bool *no_add_attrs)
7184 {
7185   tree type = NULL_TREE;
7186   int warn = 0;
7187   tree what = NULL_TREE;
7188
7189   if (!args)
7190     *no_add_attrs = true;
7191   else if (TREE_CODE (TREE_VALUE (args)) != STRING_CST)
7192     {
7193       error ("deprecated message is not a string");
7194       *no_add_attrs = true;
7195     }
7196
7197   if (DECL_P (*node))
7198     {
7199       tree decl = *node;
7200       type = TREE_TYPE (decl);
7201
7202       if (TREE_CODE (decl) == TYPE_DECL
7203           || TREE_CODE (decl) == PARM_DECL
7204           || TREE_CODE (decl) == VAR_DECL
7205           || TREE_CODE (decl) == FUNCTION_DECL
7206           || TREE_CODE (decl) == FIELD_DECL)
7207         TREE_DEPRECATED (decl) = 1;
7208       else
7209         warn = 1;
7210     }
7211   else if (TYPE_P (*node))
7212     {
7213       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
7214         *node = build_variant_type_copy (*node);
7215       TREE_DEPRECATED (*node) = 1;
7216       type = *node;
7217     }
7218   else
7219     warn = 1;
7220
7221   if (warn)
7222     {
7223       *no_add_attrs = true;
7224       if (type && TYPE_NAME (type))
7225         {
7226           if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
7227             what = TYPE_NAME (*node);
7228           else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
7229                    && DECL_NAME (TYPE_NAME (type)))
7230             what = DECL_NAME (TYPE_NAME (type));
7231         }
7232       if (what)
7233         warning (OPT_Wattributes, "%qE attribute ignored for %qE", name, what);
7234       else
7235         warning (OPT_Wattributes, "%qE attribute ignored", name);
7236     }
7237
7238   return NULL_TREE;
7239 }
7240
7241 /* Handle a "vector_size" attribute; arguments as in
7242    struct attribute_spec.handler.  */
7243
7244 static tree
7245 handle_vector_size_attribute (tree *node, tree name, tree args,
7246                               int ARG_UNUSED (flags),
7247                               bool *no_add_attrs)
7248 {
7249   unsigned HOST_WIDE_INT vecsize, nunits;
7250   enum machine_mode orig_mode;
7251   tree type = *node, new_type, size;
7252
7253   *no_add_attrs = true;
7254
7255   size = TREE_VALUE (args);
7256
7257   if (!host_integerp (size, 1))
7258     {
7259       warning (OPT_Wattributes, "%qE attribute ignored", name);
7260       return NULL_TREE;
7261     }
7262
7263   /* Get the vector size (in bytes).  */
7264   vecsize = tree_low_cst (size, 1);
7265
7266   /* We need to provide for vector pointers, vector arrays, and
7267      functions returning vectors.  For example:
7268
7269        __attribute__((vector_size(16))) short *foo;
7270
7271      In this case, the mode is SI, but the type being modified is
7272      HI, so we need to look further.  */
7273
7274   while (POINTER_TYPE_P (type)
7275          || TREE_CODE (type) == FUNCTION_TYPE
7276          || TREE_CODE (type) == METHOD_TYPE
7277          || TREE_CODE (type) == ARRAY_TYPE
7278          || TREE_CODE (type) == OFFSET_TYPE)
7279     type = TREE_TYPE (type);
7280
7281   /* Get the mode of the type being modified.  */
7282   orig_mode = TYPE_MODE (type);
7283
7284   if ((!INTEGRAL_TYPE_P (type)
7285        && !SCALAR_FLOAT_TYPE_P (type)
7286        && !FIXED_POINT_TYPE_P (type))
7287       || (!SCALAR_FLOAT_MODE_P (orig_mode)
7288           && GET_MODE_CLASS (orig_mode) != MODE_INT
7289           && !ALL_SCALAR_FIXED_POINT_MODE_P (orig_mode))
7290       || !host_integerp (TYPE_SIZE_UNIT (type), 1)
7291       || TREE_CODE (type) == BOOLEAN_TYPE)
7292     {
7293       error ("invalid vector type for attribute %qE", name);
7294       return NULL_TREE;
7295     }
7296
7297   if (vecsize % tree_low_cst (TYPE_SIZE_UNIT (type), 1))
7298     {
7299       error ("vector size not an integral multiple of component size");
7300       return NULL;
7301     }
7302
7303   if (vecsize == 0)
7304     {
7305       error ("zero vector size");
7306       return NULL;
7307     }
7308
7309   /* Calculate how many units fit in the vector.  */
7310   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
7311   if (nunits & (nunits - 1))
7312     {
7313       error ("number of components of the vector not a power of two");
7314       return NULL_TREE;
7315     }
7316
7317   new_type = build_vector_type (type, nunits);
7318
7319   /* Build back pointers if needed.  */
7320   *node = lang_hooks.types.reconstruct_complex_type (*node, new_type);
7321
7322   return NULL_TREE;
7323 }
7324
7325 /* Handle the "nonnull" attribute.  */
7326 static tree
7327 handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
7328                           tree args, int ARG_UNUSED (flags),
7329                           bool *no_add_attrs)
7330 {
7331   tree type = *node;
7332   unsigned HOST_WIDE_INT attr_arg_num;
7333
7334   /* If no arguments are specified, all pointer arguments should be
7335      non-null.  Verify a full prototype is given so that the arguments
7336      will have the correct types when we actually check them later.  */
7337   if (!args)
7338     {
7339       if (!TYPE_ARG_TYPES (type))
7340         {
7341           error ("nonnull attribute without arguments on a non-prototype");
7342           *no_add_attrs = true;
7343         }
7344       return NULL_TREE;
7345     }
7346
7347   /* Argument list specified.  Verify that each argument number references
7348      a pointer argument.  */
7349   for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
7350     {
7351       tree argument;
7352       unsigned HOST_WIDE_INT arg_num = 0, ck_num;
7353
7354       if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
7355         {
7356           error ("nonnull argument has invalid operand number (argument %lu)",
7357                  (unsigned long) attr_arg_num);
7358           *no_add_attrs = true;
7359           return NULL_TREE;
7360         }
7361
7362       argument = TYPE_ARG_TYPES (type);
7363       if (argument)
7364         {
7365           for (ck_num = 1; ; ck_num++)
7366             {
7367               if (!argument || ck_num == arg_num)
7368                 break;
7369               argument = TREE_CHAIN (argument);
7370             }
7371
7372           if (!argument
7373               || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
7374             {
7375               error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)",
7376                      (unsigned long) attr_arg_num, (unsigned long) arg_num);
7377               *no_add_attrs = true;
7378               return NULL_TREE;
7379             }
7380
7381           if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
7382             {
7383               error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)",
7384                    (unsigned long) attr_arg_num, (unsigned long) arg_num);
7385               *no_add_attrs = true;
7386               return NULL_TREE;
7387             }
7388         }
7389     }
7390
7391   return NULL_TREE;
7392 }
7393
7394 /* Check the argument list of a function call for null in argument slots
7395    that are marked as requiring a non-null pointer argument.  The NARGS
7396    arguments are passed in the array ARGARRAY.
7397 */
7398
7399 static void
7400 check_function_nonnull (tree attrs, int nargs, tree *argarray)
7401 {
7402   tree a, args;
7403   int i;
7404
7405   for (a = attrs; a; a = TREE_CHAIN (a))
7406     {
7407       if (is_attribute_p ("nonnull", TREE_PURPOSE (a)))
7408         {
7409           args = TREE_VALUE (a);
7410
7411           /* Walk the argument list.  If we encounter an argument number we
7412              should check for non-null, do it.  If the attribute has no args,
7413              then every pointer argument is checked (in which case the check
7414              for pointer type is done in check_nonnull_arg).  */
7415           for (i = 0; i < nargs; i++)
7416             {
7417               if (!args || nonnull_check_p (args, i + 1))
7418                 check_function_arguments_recurse (check_nonnull_arg, NULL,
7419                                                   argarray[i],
7420                                                   i + 1);
7421             }
7422         }
7423     }
7424 }
7425
7426 /* Check that the Nth argument of a function call (counting backwards
7427    from the end) is a (pointer)0.  The NARGS arguments are passed in the
7428    array ARGARRAY.  */
7429
7430 static void
7431 check_function_sentinel (tree attrs, int nargs, tree *argarray, tree typelist)
7432 {
7433   tree attr = lookup_attribute ("sentinel", attrs);
7434
7435   if (attr)
7436     {
7437       int len = 0;
7438       int pos = 0;
7439       tree sentinel;
7440
7441       /* Skip over the named arguments.  */
7442       while (typelist && len < nargs)
7443         {
7444           typelist = TREE_CHAIN (typelist);
7445           len++;
7446         }
7447
7448       if (TREE_VALUE (attr))
7449         {
7450           tree p = TREE_VALUE (TREE_VALUE (attr));
7451           pos = TREE_INT_CST_LOW (p);
7452         }
7453
7454       /* The sentinel must be one of the varargs, i.e.
7455          in position >= the number of fixed arguments.  */
7456       if ((nargs - 1 - pos) < len)
7457         {
7458           warning (OPT_Wformat,
7459                    "not enough variable arguments to fit a sentinel");
7460           return;
7461         }
7462
7463       /* Validate the sentinel.  */
7464       sentinel = argarray[nargs - 1 - pos];
7465       if ((!POINTER_TYPE_P (TREE_TYPE (sentinel))
7466            || !integer_zerop (sentinel))
7467           /* Although __null (in C++) is only an integer we allow it
7468              nevertheless, as we are guaranteed that it's exactly
7469              as wide as a pointer, and we don't want to force
7470              users to cast the NULL they have written there.
7471              We warn with -Wstrict-null-sentinel, though.  */
7472           && (warn_strict_null_sentinel || null_node != sentinel))
7473         warning (OPT_Wformat, "missing sentinel in function call");
7474     }
7475 }
7476
7477 /* Helper for check_function_nonnull; given a list of operands which
7478    must be non-null in ARGS, determine if operand PARAM_NUM should be
7479    checked.  */
7480
7481 static bool
7482 nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num)
7483 {
7484   unsigned HOST_WIDE_INT arg_num = 0;
7485
7486   for (; args; args = TREE_CHAIN (args))
7487     {
7488       bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num);
7489
7490       gcc_assert (found);
7491
7492       if (arg_num == param_num)
7493         return true;
7494     }
7495   return false;
7496 }
7497
7498 /* Check that the function argument PARAM (which is operand number
7499    PARAM_NUM) is non-null.  This is called by check_function_nonnull
7500    via check_function_arguments_recurse.  */
7501
7502 static void
7503 check_nonnull_arg (void * ARG_UNUSED (ctx), tree param,
7504                    unsigned HOST_WIDE_INT param_num)
7505 {
7506   /* Just skip checking the argument if it's not a pointer.  This can
7507      happen if the "nonnull" attribute was given without an operand
7508      list (which means to check every pointer argument).  */
7509
7510   if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE)
7511     return;
7512
7513   if (integer_zerop (param))
7514     warning (OPT_Wnonnull, "null argument where non-null required "
7515              "(argument %lu)", (unsigned long) param_num);
7516 }
7517
7518 /* Helper for nonnull attribute handling; fetch the operand number
7519    from the attribute argument list.  */
7520
7521 static bool
7522 get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp)
7523 {
7524   /* Verify the arg number is a constant.  */
7525   if (TREE_CODE (arg_num_expr) != INTEGER_CST
7526       || TREE_INT_CST_HIGH (arg_num_expr) != 0)
7527     return false;
7528
7529   *valp = TREE_INT_CST_LOW (arg_num_expr);
7530   return true;
7531 }
7532
7533 /* Handle a "nothrow" attribute; arguments as in
7534    struct attribute_spec.handler.  */
7535
7536 static tree
7537 handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args),
7538                           int ARG_UNUSED (flags), bool *no_add_attrs)
7539 {
7540   if (TREE_CODE (*node) == FUNCTION_DECL)
7541     TREE_NOTHROW (*node) = 1;
7542   /* ??? TODO: Support types.  */
7543   else
7544     {
7545       warning (OPT_Wattributes, "%qE attribute ignored", name);
7546       *no_add_attrs = true;
7547     }
7548
7549   return NULL_TREE;
7550 }
7551
7552 /* Handle a "cleanup" attribute; arguments as in
7553    struct attribute_spec.handler.  */
7554
7555 static tree
7556 handle_cleanup_attribute (tree *node, tree name, tree args,
7557                           int ARG_UNUSED (flags), bool *no_add_attrs)
7558 {
7559   tree decl = *node;
7560   tree cleanup_id, cleanup_decl;
7561
7562   /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do
7563      for global destructors in C++.  This requires infrastructure that
7564      we don't have generically at the moment.  It's also not a feature
7565      we'd be missing too much, since we do have attribute constructor.  */
7566   if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl))
7567     {
7568       warning (OPT_Wattributes, "%qE attribute ignored", name);
7569       *no_add_attrs = true;
7570       return NULL_TREE;
7571     }
7572
7573   /* Verify that the argument is a function in scope.  */
7574   /* ??? We could support pointers to functions here as well, if
7575      that was considered desirable.  */
7576   cleanup_id = TREE_VALUE (args);
7577   if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE)
7578     {
7579       error ("cleanup argument not an identifier");
7580       *no_add_attrs = true;
7581       return NULL_TREE;
7582     }
7583   cleanup_decl = lookup_name (cleanup_id);
7584   if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL)
7585     {
7586       error ("cleanup argument not a function");
7587       *no_add_attrs = true;
7588       return NULL_TREE;
7589     }
7590
7591   /* That the function has proper type is checked with the
7592      eventual call to build_function_call.  */
7593
7594   return NULL_TREE;
7595 }
7596
7597 /* Handle a "warn_unused_result" attribute.  No special handling.  */
7598
7599 static tree
7600 handle_warn_unused_result_attribute (tree *node, tree name,
7601                                tree ARG_UNUSED (args),
7602                                int ARG_UNUSED (flags), bool *no_add_attrs)
7603 {
7604   /* Ignore the attribute for functions not returning any value.  */
7605   if (VOID_TYPE_P (TREE_TYPE (*node)))
7606     {
7607       warning (OPT_Wattributes, "%qE attribute ignored", name);
7608       *no_add_attrs = true;
7609     }
7610
7611   return NULL_TREE;
7612 }
7613
7614 /* Handle a "sentinel" attribute.  */
7615
7616 static tree
7617 handle_sentinel_attribute (tree *node, tree name, tree args,
7618                            int ARG_UNUSED (flags), bool *no_add_attrs)
7619 {
7620   tree params = TYPE_ARG_TYPES (*node);
7621
7622   if (!params)
7623     {
7624       warning (OPT_Wattributes,
7625                "%qE attribute requires prototypes with named arguments", name);
7626       *no_add_attrs = true;
7627     }
7628   else
7629     {
7630       while (TREE_CHAIN (params))
7631         params = TREE_CHAIN (params);
7632
7633       if (VOID_TYPE_P (TREE_VALUE (params)))
7634         {
7635           warning (OPT_Wattributes,
7636                    "%qE attribute only applies to variadic functions", name);
7637           *no_add_attrs = true;
7638         }
7639     }
7640
7641   if (args)
7642     {
7643       tree position = TREE_VALUE (args);
7644
7645       if (TREE_CODE (position) != INTEGER_CST)
7646         {
7647           warning (OPT_Wattributes,
7648                    "requested position is not an integer constant");
7649           *no_add_attrs = true;
7650         }
7651       else
7652         {
7653           if (tree_int_cst_lt (position, integer_zero_node))
7654             {
7655               warning (OPT_Wattributes,
7656                        "requested position is less than zero");
7657               *no_add_attrs = true;
7658             }
7659         }
7660     }
7661
7662   return NULL_TREE;
7663 }
7664
7665 /* Handle a "type_generic" attribute.  */
7666
7667 static tree
7668 handle_type_generic_attribute (tree *node, tree ARG_UNUSED (name),
7669                                tree ARG_UNUSED (args), int ARG_UNUSED (flags),
7670                                bool * ARG_UNUSED (no_add_attrs))
7671 {
7672   tree params;
7673
7674   /* Ensure we have a function type.  */
7675   gcc_assert (TREE_CODE (*node) == FUNCTION_TYPE);
7676
7677   params = TYPE_ARG_TYPES (*node);
7678   while (params && ! VOID_TYPE_P (TREE_VALUE (params)))
7679     params = TREE_CHAIN (params);
7680
7681   /* Ensure we have a variadic function.  */
7682   gcc_assert (!params);
7683
7684   return NULL_TREE;
7685 }
7686
7687 /* Handle a "target" attribute.  */
7688
7689 static tree
7690 handle_target_attribute (tree *node, tree name, tree args, int flags,
7691                          bool *no_add_attrs)
7692 {
7693   /* Ensure we have a function type.  */
7694   if (TREE_CODE (*node) != FUNCTION_DECL)
7695     {
7696       warning (OPT_Wattributes, "%qE attribute ignored", name);
7697       *no_add_attrs = true;
7698     }
7699   else if (! targetm.target_option.valid_attribute_p (*node, name, args,
7700                                                       flags))
7701     *no_add_attrs = true;
7702
7703   return NULL_TREE;
7704 }
7705
7706 /* Arguments being collected for optimization.  */
7707 typedef const char *const_char_p;               /* For DEF_VEC_P.  */
7708 DEF_VEC_P(const_char_p);
7709 DEF_VEC_ALLOC_P(const_char_p, gc);
7710 static GTY(()) VEC(const_char_p, gc) *optimize_args;
7711
7712
7713 /* Inner function to convert a TREE_LIST to argv string to parse the optimize
7714    options in ARGS.  ATTR_P is true if this is for attribute(optimize), and
7715    false for #pragma GCC optimize.  */
7716
7717 bool
7718 parse_optimize_options (tree args, bool attr_p)
7719 {
7720   bool ret = true;
7721   unsigned opt_argc;
7722   unsigned i;
7723   int saved_flag_strict_aliasing;
7724   const char **opt_argv;
7725   tree ap;
7726
7727   /* Build up argv vector.  Just in case the string is stored away, use garbage
7728      collected strings.  */
7729   VEC_truncate (const_char_p, optimize_args, 0);
7730   VEC_safe_push (const_char_p, gc, optimize_args, NULL);
7731
7732   for (ap = args; ap != NULL_TREE; ap = TREE_CHAIN (ap))
7733     {
7734       tree value = TREE_VALUE (ap);
7735
7736       if (TREE_CODE (value) == INTEGER_CST)
7737         {
7738           char buffer[20];
7739           sprintf (buffer, "-O%ld", (long) TREE_INT_CST_LOW (value));
7740           VEC_safe_push (const_char_p, gc, optimize_args, ggc_strdup (buffer));
7741         }
7742
7743       else if (TREE_CODE (value) == STRING_CST)
7744         {
7745           /* Split string into multiple substrings.  */
7746           size_t len = TREE_STRING_LENGTH (value);
7747           char *p = ASTRDUP (TREE_STRING_POINTER (value));
7748           char *end = p + len;
7749           char *comma;
7750           char *next_p = p;
7751
7752           while (next_p != NULL)
7753             {
7754               size_t len2;
7755               char *q, *r;
7756
7757               p = next_p;
7758               comma = strchr (p, ',');
7759               if (comma)
7760                 {
7761                   len2 = comma - p;
7762                   *comma = '\0';
7763                   next_p = comma+1;
7764                 }
7765               else
7766                 {
7767                   len2 = end - p;
7768                   next_p = NULL;
7769                 }
7770
7771               r = q = (char *) ggc_alloc (len2 + 3);
7772
7773               /* If the user supplied -Oxxx or -fxxx, only allow -Oxxx or -fxxx
7774                  options.  */
7775               if (*p == '-' && p[1] != 'O' && p[1] != 'f')
7776                 {
7777                   ret = false;
7778                   if (attr_p)
7779                     warning (OPT_Wattributes,
7780                              "Bad option %s to optimize attribute.", p);
7781                   else
7782                     warning (OPT_Wpragmas,
7783                              "Bad option %s to pragma attribute", p);
7784                   continue;
7785                 }
7786
7787               if (*p != '-')
7788                 {
7789                   *r++ = '-';
7790
7791                   /* Assume that Ox is -Ox, a numeric value is -Ox, a s by
7792                      itself is -Os, and any other switch begins with a -f.  */
7793                   if ((*p >= '0' && *p <= '9')
7794                       || (p[0] == 's' && p[1] == '\0'))
7795                     *r++ = 'O';
7796                   else if (*p != 'O')
7797                     *r++ = 'f';
7798                 }
7799
7800               memcpy (r, p, len2);
7801               r[len2] = '\0';
7802               VEC_safe_push (const_char_p, gc, optimize_args, q);
7803             }
7804
7805         }
7806     }
7807
7808   opt_argc = VEC_length (const_char_p, optimize_args);
7809   opt_argv = (const char **) alloca (sizeof (char *) * (opt_argc + 1));
7810
7811   for (i = 1; i < opt_argc; i++)
7812     opt_argv[i] = VEC_index (const_char_p, optimize_args, i);
7813
7814   saved_flag_strict_aliasing = flag_strict_aliasing;
7815
7816   /* Now parse the options.  */
7817   decode_options (opt_argc, opt_argv);
7818
7819   targetm.override_options_after_change();
7820
7821   /* Don't allow changing -fstrict-aliasing.  */
7822   flag_strict_aliasing = saved_flag_strict_aliasing;
7823
7824   VEC_truncate (const_char_p, optimize_args, 0);
7825   return ret;
7826 }
7827
7828 /* For handling "optimize" attribute. arguments as in
7829    struct attribute_spec.handler.  */
7830
7831 static tree
7832 handle_optimize_attribute (tree *node, tree name, tree args,
7833                            int ARG_UNUSED (flags), bool *no_add_attrs)
7834 {
7835   /* Ensure we have a function type.  */
7836   if (TREE_CODE (*node) != FUNCTION_DECL)
7837     {
7838       warning (OPT_Wattributes, "%qE attribute ignored", name);
7839       *no_add_attrs = true;
7840     }
7841   else
7842     {
7843       struct cl_optimization cur_opts;
7844       tree old_opts = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node);
7845
7846       /* Save current options.  */
7847       cl_optimization_save (&cur_opts);
7848
7849       /* If we previously had some optimization options, use them as the
7850          default.  */
7851       if (old_opts)
7852         cl_optimization_restore (TREE_OPTIMIZATION (old_opts));
7853
7854       /* Parse options, and update the vector.  */
7855       parse_optimize_options (args, true);
7856       DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node)
7857         = build_optimization_node ();
7858
7859       /* Restore current options.  */
7860       cl_optimization_restore (&cur_opts);
7861     }
7862
7863   return NULL_TREE;
7864 }
7865 \f
7866 /* Check for valid arguments being passed to a function.
7867    ATTRS is a list of attributes.  There are NARGS arguments in the array
7868    ARGARRAY.  TYPELIST is the list of argument types for the function.
7869  */
7870 void
7871 check_function_arguments (tree attrs, int nargs, tree *argarray, tree typelist)
7872 {
7873   /* Check for null being passed in a pointer argument that must be
7874      non-null.  We also need to do this if format checking is enabled.  */
7875
7876   if (warn_nonnull)
7877     check_function_nonnull (attrs, nargs, argarray);
7878
7879   /* Check for errors in format strings.  */
7880
7881   if (warn_format || warn_missing_format_attribute)
7882     check_function_format (attrs, nargs, argarray);
7883
7884   if (warn_format)
7885     check_function_sentinel (attrs, nargs, argarray, typelist);
7886 }
7887
7888 /* Generic argument checking recursion routine.  PARAM is the argument to
7889    be checked.  PARAM_NUM is the number of the argument.  CALLBACK is invoked
7890    once the argument is resolved.  CTX is context for the callback.  */
7891 void
7892 check_function_arguments_recurse (void (*callback)
7893                                   (void *, tree, unsigned HOST_WIDE_INT),
7894                                   void *ctx, tree param,
7895                                   unsigned HOST_WIDE_INT param_num)
7896 {
7897   if (CONVERT_EXPR_P (param)
7898       && (TYPE_PRECISION (TREE_TYPE (param))
7899           == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (param, 0)))))
7900     {
7901       /* Strip coercion.  */
7902       check_function_arguments_recurse (callback, ctx,
7903                                         TREE_OPERAND (param, 0), param_num);
7904       return;
7905     }
7906
7907   if (TREE_CODE (param) == CALL_EXPR)
7908     {
7909       tree type = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (param)));
7910       tree attrs;
7911       bool found_format_arg = false;
7912
7913       /* See if this is a call to a known internationalization function
7914          that modifies a format arg.  Such a function may have multiple
7915          format_arg attributes (for example, ngettext).  */
7916
7917       for (attrs = TYPE_ATTRIBUTES (type);
7918            attrs;
7919            attrs = TREE_CHAIN (attrs))
7920         if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs)))
7921           {
7922             tree inner_arg;
7923             tree format_num_expr;
7924             int format_num;
7925             int i;
7926             call_expr_arg_iterator iter;
7927
7928             /* Extract the argument number, which was previously checked
7929                to be valid.  */
7930             format_num_expr = TREE_VALUE (TREE_VALUE (attrs));
7931
7932             gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST
7933                         && !TREE_INT_CST_HIGH (format_num_expr));
7934
7935             format_num = TREE_INT_CST_LOW (format_num_expr);
7936
7937             for (inner_arg = first_call_expr_arg (param, &iter), i = 1;
7938                  inner_arg != 0;
7939                  inner_arg = next_call_expr_arg (&iter), i++)
7940               if (i == format_num)
7941                 {
7942                   check_function_arguments_recurse (callback, ctx,
7943                                                     inner_arg, param_num);
7944                   found_format_arg = true;
7945                   break;
7946                 }
7947           }
7948
7949       /* If we found a format_arg attribute and did a recursive check,
7950          we are done with checking this argument.  Otherwise, we continue
7951          and this will be considered a non-literal.  */
7952       if (found_format_arg)
7953         return;
7954     }
7955
7956   if (TREE_CODE (param) == COND_EXPR)
7957     {
7958       /* Check both halves of the conditional expression.  */
7959       check_function_arguments_recurse (callback, ctx,
7960                                         TREE_OPERAND (param, 1), param_num);
7961       check_function_arguments_recurse (callback, ctx,
7962                                         TREE_OPERAND (param, 2), param_num);
7963       return;
7964     }
7965
7966   (*callback) (ctx, param, param_num);
7967 }
7968
7969 /* Checks for a builtin function FNDECL that the number of arguments
7970    NARGS against the required number REQUIRED and issues an error if
7971    there is a mismatch.  Returns true if the number of arguments is
7972    correct, otherwise false.  */
7973
7974 static bool
7975 builtin_function_validate_nargs (tree fndecl, int nargs, int required)
7976 {
7977   if (nargs < required)
7978     {
7979       error_at (input_location,
7980                 "not enough arguments to function %qE", fndecl);
7981       return false;
7982     }
7983   else if (nargs > required)
7984     {
7985       error_at (input_location,
7986                 "too many arguments to function %qE", fndecl);
7987       return false;
7988     }
7989   return true;
7990 }
7991
7992 /* Verifies the NARGS arguments ARGS to the builtin function FNDECL.
7993    Returns false if there was an error, otherwise true.  */
7994
7995 bool
7996 check_builtin_function_arguments (tree fndecl, int nargs, tree *args)
7997 {
7998   if (!DECL_BUILT_IN (fndecl)
7999       || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL)
8000     return true;
8001
8002   switch (DECL_FUNCTION_CODE (fndecl))
8003     {
8004     case BUILT_IN_CONSTANT_P:
8005       return builtin_function_validate_nargs (fndecl, nargs, 1);
8006
8007     case BUILT_IN_ISFINITE:
8008     case BUILT_IN_ISINF:
8009     case BUILT_IN_ISINF_SIGN:
8010     case BUILT_IN_ISNAN:
8011     case BUILT_IN_ISNORMAL:
8012       if (builtin_function_validate_nargs (fndecl, nargs, 1))
8013         {
8014           if (TREE_CODE (TREE_TYPE (args[0])) != REAL_TYPE)
8015             {
8016               error ("non-floating-point argument in call to "
8017                      "function %qE", fndecl);
8018               return false;
8019             }
8020           return true;
8021         }
8022       return false;
8023
8024     case BUILT_IN_ISGREATER:
8025     case BUILT_IN_ISGREATEREQUAL:
8026     case BUILT_IN_ISLESS:
8027     case BUILT_IN_ISLESSEQUAL:
8028     case BUILT_IN_ISLESSGREATER:
8029     case BUILT_IN_ISUNORDERED:
8030       if (builtin_function_validate_nargs (fndecl, nargs, 2))
8031         {
8032           enum tree_code code0, code1;
8033           code0 = TREE_CODE (TREE_TYPE (args[0]));
8034           code1 = TREE_CODE (TREE_TYPE (args[1]));
8035           if (!((code0 == REAL_TYPE && code1 == REAL_TYPE)
8036                 || (code0 == REAL_TYPE && code1 == INTEGER_TYPE)
8037                 || (code0 == INTEGER_TYPE && code1 == REAL_TYPE)))
8038             {
8039               error ("non-floating-point arguments in call to "
8040                      "function %qE", fndecl);
8041               return false;
8042             }
8043           return true;
8044         }
8045       return false;
8046
8047     case BUILT_IN_FPCLASSIFY:
8048       if (builtin_function_validate_nargs (fndecl, nargs, 6))
8049         {
8050           unsigned i;
8051
8052           for (i=0; i<5; i++)
8053             if (TREE_CODE (args[i]) != INTEGER_CST)
8054               {
8055                 error ("non-const integer argument %u in call to function %qE",
8056                        i+1, fndecl);
8057                 return false;
8058               }
8059
8060           if (TREE_CODE (TREE_TYPE (args[5])) != REAL_TYPE)
8061             {
8062               error ("non-floating-point argument in call to function %qE",
8063                      fndecl);
8064               return false;
8065             }
8066           return true;
8067         }
8068       return false;
8069
8070     default:
8071       return true;
8072     }
8073 }
8074
8075 /* Function to help qsort sort FIELD_DECLs by name order.  */
8076
8077 int
8078 field_decl_cmp (const void *x_p, const void *y_p)
8079 {
8080   const tree *const x = (const tree *const) x_p;
8081   const tree *const y = (const tree *const) y_p;
8082
8083   if (DECL_NAME (*x) == DECL_NAME (*y))
8084     /* A nontype is "greater" than a type.  */
8085     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
8086   if (DECL_NAME (*x) == NULL_TREE)
8087     return -1;
8088   if (DECL_NAME (*y) == NULL_TREE)
8089     return 1;
8090   if (DECL_NAME (*x) < DECL_NAME (*y))
8091     return -1;
8092   return 1;
8093 }
8094
8095 static struct {
8096   gt_pointer_operator new_value;
8097   void *cookie;
8098 } resort_data;
8099
8100 /* This routine compares two fields like field_decl_cmp but using the
8101 pointer operator in resort_data.  */
8102
8103 static int
8104 resort_field_decl_cmp (const void *x_p, const void *y_p)
8105 {
8106   const tree *const x = (const tree *const) x_p;
8107   const tree *const y = (const tree *const) y_p;
8108
8109   if (DECL_NAME (*x) == DECL_NAME (*y))
8110     /* A nontype is "greater" than a type.  */
8111     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
8112   if (DECL_NAME (*x) == NULL_TREE)
8113     return -1;
8114   if (DECL_NAME (*y) == NULL_TREE)
8115     return 1;
8116   {
8117     tree d1 = DECL_NAME (*x);
8118     tree d2 = DECL_NAME (*y);
8119     resort_data.new_value (&d1, resort_data.cookie);
8120     resort_data.new_value (&d2, resort_data.cookie);
8121     if (d1 < d2)
8122       return -1;
8123   }
8124   return 1;
8125 }
8126
8127 /* Resort DECL_SORTED_FIELDS because pointers have been reordered.  */
8128
8129 void
8130 resort_sorted_fields (void *obj,
8131                       void * ARG_UNUSED (orig_obj),
8132                       gt_pointer_operator new_value,
8133                       void *cookie)
8134 {
8135   struct sorted_fields_type *sf = (struct sorted_fields_type *) obj;
8136   resort_data.new_value = new_value;
8137   resort_data.cookie = cookie;
8138   qsort (&sf->elts[0], sf->len, sizeof (tree),
8139          resort_field_decl_cmp);
8140 }
8141
8142 /* Subroutine of c_parse_error.
8143    Return the result of concatenating LHS and RHS. RHS is really
8144    a string literal, its first character is indicated by RHS_START and
8145    RHS_SIZE is its length (including the terminating NUL character).
8146
8147    The caller is responsible for deleting the returned pointer.  */
8148
8149 static char *
8150 catenate_strings (const char *lhs, const char *rhs_start, int rhs_size)
8151 {
8152   const int lhs_size = strlen (lhs);
8153   char *result = XNEWVEC (char, lhs_size + rhs_size);
8154   strncpy (result, lhs, lhs_size);
8155   strncpy (result + lhs_size, rhs_start, rhs_size);
8156   return result;
8157 }
8158
8159 /* Issue the error given by GMSGID, indicating that it occurred before
8160    TOKEN, which had the associated VALUE.  */
8161
8162 void
8163 c_parse_error (const char *gmsgid, enum cpp_ttype token_type,
8164                tree value, unsigned char token_flags)
8165 {
8166 #define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2))
8167
8168   char *message = NULL;
8169
8170   if (token_type == CPP_EOF)
8171     message = catenate_messages (gmsgid, " at end of input");
8172   else if (token_type == CPP_CHAR
8173            || token_type == CPP_WCHAR
8174            || token_type == CPP_CHAR16
8175            || token_type == CPP_CHAR32)
8176     {
8177       unsigned int val = TREE_INT_CST_LOW (value);
8178       const char *prefix;
8179
8180       switch (token_type)
8181         {
8182         default:
8183           prefix = "";
8184           break;
8185         case CPP_WCHAR:
8186           prefix = "L";
8187           break;
8188         case CPP_CHAR16:
8189           prefix = "u";
8190           break;
8191         case CPP_CHAR32:
8192           prefix = "U";
8193           break;
8194         }
8195
8196       if (val <= UCHAR_MAX && ISGRAPH (val))
8197         message = catenate_messages (gmsgid, " before %s'%c'");
8198       else
8199         message = catenate_messages (gmsgid, " before %s'\\x%x'");
8200
8201       error (message, prefix, val);
8202       free (message);
8203       message = NULL;
8204     }
8205   else if (token_type == CPP_STRING
8206            || token_type == CPP_WSTRING
8207            || token_type == CPP_STRING16
8208            || token_type == CPP_STRING32
8209            || token_type == CPP_UTF8STRING)
8210     message = catenate_messages (gmsgid, " before string constant");
8211   else if (token_type == CPP_NUMBER)
8212     message = catenate_messages (gmsgid, " before numeric constant");
8213   else if (token_type == CPP_NAME)
8214     {
8215       message = catenate_messages (gmsgid, " before %qE");
8216       error (message, value);
8217       free (message);
8218       message = NULL;
8219     }
8220   else if (token_type == CPP_PRAGMA)
8221     message = catenate_messages (gmsgid, " before %<#pragma%>");
8222   else if (token_type == CPP_PRAGMA_EOL)
8223     message = catenate_messages (gmsgid, " before end of line");
8224   else if (token_type < N_TTYPES)
8225     {
8226       message = catenate_messages (gmsgid, " before %qs token");
8227       error (message, cpp_type2name (token_type, token_flags));
8228       free (message);
8229       message = NULL;
8230     }
8231   else
8232     error (gmsgid);
8233
8234   if (message)
8235     {
8236       error (message);
8237       free (message);
8238     }
8239 #undef catenate_messages
8240 }
8241
8242 /* Callback from cpp_error for PFILE to print diagnostics from the
8243    preprocessor.  The diagnostic is of type LEVEL, at location
8244    LOCATION unless this is after lexing and the compiler's location
8245    should be used instead, with column number possibly overridden by
8246    COLUMN_OVERRIDE if not zero; MSG is the translated message and AP
8247    the arguments.  Returns true if a diagnostic was emitted, false
8248    otherwise.  */
8249
8250 bool
8251 c_cpp_error (cpp_reader *pfile ATTRIBUTE_UNUSED, int level,
8252              location_t location, unsigned int column_override,
8253              const char *msg, va_list *ap)
8254 {
8255   diagnostic_info diagnostic;
8256   diagnostic_t dlevel;
8257   int save_warn_system_headers = warn_system_headers;
8258   bool ret;
8259
8260   switch (level)
8261     {
8262     case CPP_DL_WARNING_SYSHDR:
8263       if (flag_no_output)
8264         return false;
8265       warn_system_headers = 1;
8266       /* Fall through.  */
8267     case CPP_DL_WARNING:
8268       if (flag_no_output)
8269         return false;
8270       dlevel = DK_WARNING;
8271       break;
8272     case CPP_DL_PEDWARN:
8273       if (flag_no_output && !flag_pedantic_errors)
8274         return false;
8275       dlevel = DK_PEDWARN;
8276       break;
8277     case CPP_DL_ERROR:
8278       dlevel = DK_ERROR;
8279       break;
8280     case CPP_DL_ICE:
8281       dlevel = DK_ICE;
8282       break;
8283     case CPP_DL_NOTE:
8284       dlevel = DK_NOTE;
8285       break;
8286     case CPP_DL_FATAL:
8287       dlevel = DK_FATAL;
8288       break;
8289     default:
8290       gcc_unreachable ();
8291     }
8292   if (done_lexing)
8293     location = input_location;
8294   diagnostic_set_info_translated (&diagnostic, msg, ap,
8295                                   location, dlevel);
8296   if (column_override)
8297     diagnostic_override_column (&diagnostic, column_override);
8298   ret = report_diagnostic (&diagnostic);
8299   if (level == CPP_DL_WARNING_SYSHDR)
8300     warn_system_headers = save_warn_system_headers;
8301   return ret;
8302 }
8303
8304 /* Convert a character from the host to the target execution character
8305    set.  cpplib handles this, mostly.  */
8306
8307 HOST_WIDE_INT
8308 c_common_to_target_charset (HOST_WIDE_INT c)
8309 {
8310   /* Character constants in GCC proper are sign-extended under -fsigned-char,
8311      zero-extended under -fno-signed-char.  cpplib insists that characters
8312      and character constants are always unsigned.  Hence we must convert
8313      back and forth.  */
8314   cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1);
8315
8316   uc = cpp_host_to_exec_charset (parse_in, uc);
8317
8318   if (flag_signed_char)
8319     return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE)
8320                                >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE);
8321   else
8322     return uc;
8323 }
8324
8325 /* Build the result of __builtin_offsetof.  EXPR is a nested sequence of
8326    component references, with STOP_REF, or alternatively an INDIRECT_REF of
8327    NULL, at the bottom; much like the traditional rendering of offsetof as a
8328    macro.  Returns the folded and properly cast result.  */
8329
8330 static tree
8331 fold_offsetof_1 (tree expr, tree stop_ref)
8332 {
8333   enum tree_code code = PLUS_EXPR;
8334   tree base, off, t;
8335
8336   if (expr == stop_ref && TREE_CODE (expr) != ERROR_MARK)
8337     return size_zero_node;
8338
8339   switch (TREE_CODE (expr))
8340     {
8341     case ERROR_MARK:
8342       return expr;
8343
8344     case VAR_DECL:
8345       error ("cannot apply %<offsetof%> to static data member %qD", expr);
8346       return error_mark_node;
8347
8348     case CALL_EXPR:
8349     case TARGET_EXPR:
8350       error ("cannot apply %<offsetof%> when %<operator[]%> is overloaded");
8351       return error_mark_node;
8352
8353     case NOP_EXPR:
8354     case INDIRECT_REF:
8355       if (!integer_zerop (TREE_OPERAND (expr, 0)))
8356         {
8357           error ("cannot apply %<offsetof%> to a non constant address");
8358           return error_mark_node;
8359         }
8360       return size_zero_node;
8361
8362     case COMPONENT_REF:
8363       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
8364       if (base == error_mark_node)
8365         return base;
8366
8367       t = TREE_OPERAND (expr, 1);
8368       if (DECL_C_BIT_FIELD (t))
8369         {
8370           error ("attempt to take address of bit-field structure "
8371                  "member %qD", t);
8372           return error_mark_node;
8373         }
8374       off = size_binop_loc (input_location, PLUS_EXPR, DECL_FIELD_OFFSET (t),
8375                             size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t),
8376                                                     1)
8377                                       / BITS_PER_UNIT));
8378       break;
8379
8380     case ARRAY_REF:
8381       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
8382       if (base == error_mark_node)
8383         return base;
8384
8385       t = TREE_OPERAND (expr, 1);
8386       if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0)
8387         {
8388           code = MINUS_EXPR;
8389           t = fold_build1_loc (input_location, NEGATE_EXPR, TREE_TYPE (t), t);
8390         }
8391       t = convert (sizetype, t);
8392       off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
8393
8394       /* Check if the offset goes beyond the upper bound of the array.  */
8395       if (code == PLUS_EXPR && TREE_CODE (t) == INTEGER_CST)
8396         {
8397           tree upbound = array_ref_up_bound (expr);
8398           if (upbound != NULL_TREE
8399               && TREE_CODE (upbound) == INTEGER_CST
8400               && !tree_int_cst_equal (upbound,
8401                                       TYPE_MAX_VALUE (TREE_TYPE (upbound))))
8402             {
8403               upbound = size_binop (PLUS_EXPR, upbound,
8404                                     build_int_cst (TREE_TYPE (upbound), 1));
8405               if (tree_int_cst_lt (upbound, t))
8406                 {
8407                   tree v;
8408
8409                   for (v = TREE_OPERAND (expr, 0);
8410                        TREE_CODE (v) == COMPONENT_REF;
8411                        v = TREE_OPERAND (v, 0))
8412                     if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
8413                         == RECORD_TYPE)
8414                       {
8415                         tree fld_chain = TREE_CHAIN (TREE_OPERAND (v, 1));
8416                         for (; fld_chain; fld_chain = TREE_CHAIN (fld_chain))
8417                           if (TREE_CODE (fld_chain) == FIELD_DECL)
8418                             break;
8419
8420                         if (fld_chain)
8421                           break;
8422                       }
8423                   /* Don't warn if the array might be considered a poor
8424                      man's flexible array member with a very permissive
8425                      definition thereof.  */
8426                   if (TREE_CODE (v) == ARRAY_REF
8427                       || TREE_CODE (v) == COMPONENT_REF)
8428                     warning (OPT_Warray_bounds,
8429                              "index %E denotes an offset "
8430                              "greater than size of %qT",
8431                              t, TREE_TYPE (TREE_OPERAND (expr, 0)));
8432                 }
8433             }
8434         }
8435       break;
8436
8437     case COMPOUND_EXPR:
8438       /* Handle static members of volatile structs.  */
8439       t = TREE_OPERAND (expr, 1);
8440       gcc_assert (TREE_CODE (t) == VAR_DECL);
8441       return fold_offsetof_1 (t, stop_ref);
8442
8443     default:
8444       gcc_unreachable ();
8445     }
8446
8447   return size_binop (code, base, off);
8448 }
8449
8450 tree
8451 fold_offsetof (tree expr, tree stop_ref)
8452 {
8453   /* Convert back from the internal sizetype to size_t.  */
8454   return convert (size_type_node, fold_offsetof_1 (expr, stop_ref));
8455 }
8456
8457 /* Print an error message for an invalid lvalue.  USE says
8458    how the lvalue is being used and so selects the error message.  */
8459
8460 void
8461 lvalue_error (enum lvalue_use use)
8462 {
8463   switch (use)
8464     {
8465     case lv_assign:
8466       error ("lvalue required as left operand of assignment");
8467       break;
8468     case lv_increment:
8469       error ("lvalue required as increment operand");
8470       break;
8471     case lv_decrement:
8472       error ("lvalue required as decrement operand");
8473       break;
8474     case lv_addressof:
8475       error ("lvalue required as unary %<&%> operand");
8476       break;
8477     case lv_asm:
8478       error ("lvalue required in asm statement");
8479       break;
8480     default:
8481       gcc_unreachable ();
8482     }
8483 }
8484 \f
8485 /* *PTYPE is an incomplete array.  Complete it with a domain based on
8486    INITIAL_VALUE.  If INITIAL_VALUE is not present, use 1 if DO_DEFAULT
8487    is true.  Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered,
8488    2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty.  */
8489
8490 int
8491 complete_array_type (tree *ptype, tree initial_value, bool do_default)
8492 {
8493   tree maxindex, type, main_type, elt, unqual_elt;
8494   int failure = 0, quals;
8495   hashval_t hashcode = 0;
8496
8497   maxindex = size_zero_node;
8498   if (initial_value)
8499     {
8500       if (TREE_CODE (initial_value) == STRING_CST)
8501         {
8502           int eltsize
8503             = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value)));
8504           maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1);
8505         }
8506       else if (TREE_CODE (initial_value) == CONSTRUCTOR)
8507         {
8508           VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (initial_value);
8509
8510           if (VEC_empty (constructor_elt, v))
8511             {
8512               if (pedantic)
8513                 failure = 3;
8514               maxindex = integer_minus_one_node;
8515             }
8516           else
8517             {
8518               tree curindex;
8519               unsigned HOST_WIDE_INT cnt;
8520               constructor_elt *ce;
8521               bool fold_p = false;
8522
8523               if (VEC_index (constructor_elt, v, 0)->index)
8524                 maxindex = fold_convert_loc (input_location, sizetype,
8525                                              VEC_index (constructor_elt,
8526                                                         v, 0)->index);
8527               curindex = maxindex;
8528
8529               for (cnt = 1;
8530                    VEC_iterate (constructor_elt, v, cnt, ce);
8531                    cnt++)
8532                 {
8533                   bool curfold_p = false;
8534                   if (ce->index)
8535                     curindex = ce->index, curfold_p = true;
8536                   else
8537                     {
8538                       if (fold_p)
8539                         curindex = fold_convert (sizetype, curindex);
8540                       curindex = size_binop (PLUS_EXPR, curindex,
8541                                              size_one_node);
8542                     }
8543                   if (tree_int_cst_lt (maxindex, curindex))
8544                     maxindex = curindex, fold_p = curfold_p;
8545                 }
8546                if (fold_p)
8547                  maxindex = fold_convert (sizetype, maxindex);
8548             }
8549         }
8550       else
8551         {
8552           /* Make an error message unless that happened already.  */
8553           if (initial_value != error_mark_node)
8554             failure = 1;
8555         }
8556     }
8557   else
8558     {
8559       failure = 2;
8560       if (!do_default)
8561         return failure;
8562     }
8563
8564   type = *ptype;
8565   elt = TREE_TYPE (type);
8566   quals = TYPE_QUALS (strip_array_types (elt));
8567   if (quals == 0)
8568     unqual_elt = elt;
8569   else
8570     unqual_elt = c_build_qualified_type (elt, KEEP_QUAL_ADDR_SPACE (quals));
8571
8572   /* Using build_distinct_type_copy and modifying things afterward instead
8573      of using build_array_type to create a new type preserves all of the
8574      TYPE_LANG_FLAG_? bits that the front end may have set.  */
8575   main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
8576   TREE_TYPE (main_type) = unqual_elt;
8577   TYPE_DOMAIN (main_type) = build_index_type (maxindex);
8578   layout_type (main_type);
8579
8580   /* Make sure we have the canonical MAIN_TYPE. */
8581   hashcode = iterative_hash_object (TYPE_HASH (unqual_elt), hashcode);
8582   hashcode = iterative_hash_object (TYPE_HASH (TYPE_DOMAIN (main_type)),
8583                                     hashcode);
8584   main_type = type_hash_canon (hashcode, main_type);
8585
8586   /* Fix the canonical type.  */
8587   if (TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (main_type))
8588       || TYPE_STRUCTURAL_EQUALITY_P (TYPE_DOMAIN (main_type)))
8589     SET_TYPE_STRUCTURAL_EQUALITY (main_type);
8590   else if (TYPE_CANONICAL (TREE_TYPE (main_type)) != TREE_TYPE (main_type)
8591            || (TYPE_CANONICAL (TYPE_DOMAIN (main_type))
8592                != TYPE_DOMAIN (main_type)))
8593     TYPE_CANONICAL (main_type)
8594       = build_array_type (TYPE_CANONICAL (TREE_TYPE (main_type)),
8595                           TYPE_CANONICAL (TYPE_DOMAIN (main_type)));
8596   else
8597     TYPE_CANONICAL (main_type) = main_type;
8598
8599   if (quals == 0)
8600     type = main_type;
8601   else
8602     type = c_build_qualified_type (main_type, quals);
8603
8604   if (COMPLETE_TYPE_P (type)
8605       && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST
8606       && TREE_OVERFLOW (TYPE_SIZE_UNIT (type)))
8607     {
8608       error ("size of array is too large");
8609       /* If we proceed with the array type as it is, we'll eventually
8610          crash in tree_low_cst().  */
8611       type = error_mark_node;
8612     }
8613
8614   *ptype = type;
8615   return failure;
8616 }
8617
8618 \f
8619 /* Used to help initialize the builtin-types.def table.  When a type of
8620    the correct size doesn't exist, use error_mark_node instead of NULL.
8621    The later results in segfaults even when a decl using the type doesn't
8622    get invoked.  */
8623
8624 tree
8625 builtin_type_for_size (int size, bool unsignedp)
8626 {
8627   tree type = lang_hooks.types.type_for_size (size, unsignedp);
8628   return type ? type : error_mark_node;
8629 }
8630
8631 /* A helper function for resolve_overloaded_builtin in resolving the
8632    overloaded __sync_ builtins.  Returns a positive power of 2 if the
8633    first operand of PARAMS is a pointer to a supported data type.
8634    Returns 0 if an error is encountered.  */
8635
8636 static int
8637 sync_resolve_size (tree function, VEC(tree,gc) *params)
8638 {
8639   tree type;
8640   int size;
8641
8642   if (VEC_empty (tree, params))
8643     {
8644       error ("too few arguments to function %qE", function);
8645       return 0;
8646     }
8647
8648   type = TREE_TYPE (VEC_index (tree, params, 0));
8649   if (TREE_CODE (type) != POINTER_TYPE)
8650     goto incompatible;
8651
8652   type = TREE_TYPE (type);
8653   if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
8654     goto incompatible;
8655
8656   size = tree_low_cst (TYPE_SIZE_UNIT (type), 1);
8657   if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16)
8658     return size;
8659
8660  incompatible:
8661   error ("incompatible type for argument %d of %qE", 1, function);
8662   return 0;
8663 }
8664
8665 /* A helper function for resolve_overloaded_builtin.  Adds casts to
8666    PARAMS to make arguments match up with those of FUNCTION.  Drops
8667    the variadic arguments at the end.  Returns false if some error
8668    was encountered; true on success.  */
8669
8670 static bool
8671 sync_resolve_params (tree orig_function, tree function, VEC(tree, gc) *params)
8672 {
8673   tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (function));
8674   tree ptype;
8675   int number;
8676   unsigned int parmnum;
8677
8678   /* We've declared the implementation functions to use "volatile void *"
8679      as the pointer parameter, so we shouldn't get any complaints from the
8680      call to check_function_arguments what ever type the user used.  */
8681   arg_types = TREE_CHAIN (arg_types);
8682   ptype = TREE_TYPE (TREE_TYPE (VEC_index (tree, params, 0)));
8683   number = 2;
8684
8685   /* For the rest of the values, we need to cast these to FTYPE, so that we
8686      don't get warnings for passing pointer types, etc.  */
8687   parmnum = 0;
8688   while (arg_types != void_list_node)
8689     {
8690       tree val;
8691
8692       ++parmnum;
8693       if (VEC_length (tree, params) <= parmnum)
8694         {
8695           error ("too few arguments to function %qE", orig_function);
8696           return false;
8697         }
8698
8699       /* ??? Ideally for the first conversion we'd use convert_for_assignment
8700          so that we get warnings for anything that doesn't match the pointer
8701          type.  This isn't portable across the C and C++ front ends atm.  */
8702       val = VEC_index (tree, params, parmnum);
8703       val = convert (ptype, val);
8704       val = convert (TREE_VALUE (arg_types), val);
8705       VEC_replace (tree, params, parmnum, val);
8706
8707       arg_types = TREE_CHAIN (arg_types);
8708       number++;
8709     }
8710
8711   /* The definition of these primitives is variadic, with the remaining
8712      being "an optional list of variables protected by the memory barrier".
8713      No clue what that's supposed to mean, precisely, but we consider all
8714      call-clobbered variables to be protected so we're safe.  */
8715   VEC_truncate (tree, params, parmnum + 1);
8716
8717   return true;
8718 }
8719
8720 /* A helper function for resolve_overloaded_builtin.  Adds a cast to
8721    RESULT to make it match the type of the first pointer argument in
8722    PARAMS.  */
8723
8724 static tree
8725 sync_resolve_return (tree first_param, tree result)
8726 {
8727   tree ptype = TREE_TYPE (TREE_TYPE (first_param));
8728   ptype = TYPE_MAIN_VARIANT (ptype);
8729   return convert (ptype, result);
8730 }
8731
8732 /* Some builtin functions are placeholders for other expressions.  This
8733    function should be called immediately after parsing the call expression
8734    before surrounding code has committed to the type of the expression.
8735
8736    LOC is the location of the builtin call.
8737
8738    FUNCTION is the DECL that has been invoked; it is known to be a builtin.
8739    PARAMS is the argument list for the call.  The return value is non-null
8740    when expansion is complete, and null if normal processing should
8741    continue.  */
8742
8743 tree
8744 resolve_overloaded_builtin (location_t loc, tree function, VEC(tree,gc) *params)
8745 {
8746   enum built_in_function orig_code = DECL_FUNCTION_CODE (function);
8747   switch (DECL_BUILT_IN_CLASS (function))
8748     {
8749     case BUILT_IN_NORMAL:
8750       break;
8751     case BUILT_IN_MD:
8752       if (targetm.resolve_overloaded_builtin)
8753         return targetm.resolve_overloaded_builtin (loc, function, params);
8754       else
8755         return NULL_TREE;
8756     default:
8757       return NULL_TREE;
8758     }
8759
8760   /* Handle BUILT_IN_NORMAL here.  */
8761   switch (orig_code)
8762     {
8763     case BUILT_IN_FETCH_AND_ADD_N:
8764     case BUILT_IN_FETCH_AND_SUB_N:
8765     case BUILT_IN_FETCH_AND_OR_N:
8766     case BUILT_IN_FETCH_AND_AND_N:
8767     case BUILT_IN_FETCH_AND_XOR_N:
8768     case BUILT_IN_FETCH_AND_NAND_N:
8769     case BUILT_IN_ADD_AND_FETCH_N:
8770     case BUILT_IN_SUB_AND_FETCH_N:
8771     case BUILT_IN_OR_AND_FETCH_N:
8772     case BUILT_IN_AND_AND_FETCH_N:
8773     case BUILT_IN_XOR_AND_FETCH_N:
8774     case BUILT_IN_NAND_AND_FETCH_N:
8775     case BUILT_IN_BOOL_COMPARE_AND_SWAP_N:
8776     case BUILT_IN_VAL_COMPARE_AND_SWAP_N:
8777     case BUILT_IN_LOCK_TEST_AND_SET_N:
8778     case BUILT_IN_LOCK_RELEASE_N:
8779       {
8780         int n = sync_resolve_size (function, params);
8781         tree new_function, first_param, result;
8782
8783         if (n == 0)
8784           return error_mark_node;
8785
8786         new_function = built_in_decls[orig_code + exact_log2 (n) + 1];
8787         if (!sync_resolve_params (function, new_function, params))
8788           return error_mark_node;
8789
8790         first_param = VEC_index (tree, params, 0);
8791         result = build_function_call_vec (loc, new_function, params, NULL);
8792         if (orig_code != BUILT_IN_BOOL_COMPARE_AND_SWAP_N
8793             && orig_code != BUILT_IN_LOCK_RELEASE_N)
8794           result = sync_resolve_return (first_param, result);
8795
8796         return result;
8797       }
8798
8799     default:
8800       return NULL_TREE;
8801     }
8802 }
8803
8804 /* Ignoring their sign, return true if two scalar types are the same.  */
8805 bool
8806 same_scalar_type_ignoring_signedness (tree t1, tree t2)
8807 {
8808   enum tree_code c1 = TREE_CODE (t1), c2 = TREE_CODE (t2);
8809
8810   gcc_assert ((c1 == INTEGER_TYPE || c1 == REAL_TYPE || c1 == FIXED_POINT_TYPE)
8811               && (c2 == INTEGER_TYPE || c2 == REAL_TYPE
8812                   || c2 == FIXED_POINT_TYPE));
8813
8814   /* Equality works here because c_common_signed_type uses
8815      TYPE_MAIN_VARIANT.  */
8816   return c_common_signed_type (t1)
8817     == c_common_signed_type (t2);
8818 }
8819
8820 /* Check for missing format attributes on function pointers.  LTYPE is
8821    the new type or left-hand side type.  RTYPE is the old type or
8822    right-hand side type.  Returns TRUE if LTYPE is missing the desired
8823    attribute.  */
8824
8825 bool
8826 check_missing_format_attribute (tree ltype, tree rtype)
8827 {
8828   tree const ttr = TREE_TYPE (rtype), ttl = TREE_TYPE (ltype);
8829   tree ra;
8830
8831   for (ra = TYPE_ATTRIBUTES (ttr); ra; ra = TREE_CHAIN (ra))
8832     if (is_attribute_p ("format", TREE_PURPOSE (ra)))
8833       break;
8834   if (ra)
8835     {
8836       tree la;
8837       for (la = TYPE_ATTRIBUTES (ttl); la; la = TREE_CHAIN (la))
8838         if (is_attribute_p ("format", TREE_PURPOSE (la)))
8839           break;
8840       return !la;
8841     }
8842   else
8843     return false;
8844 }
8845
8846 /* Subscripting with type char is likely to lose on a machine where
8847    chars are signed.  So warn on any machine, but optionally.  Don't
8848    warn for unsigned char since that type is safe.  Don't warn for
8849    signed char because anyone who uses that must have done so
8850    deliberately. Furthermore, we reduce the false positive load by
8851    warning only for non-constant value of type char.  */
8852
8853 void
8854 warn_array_subscript_with_type_char (tree index)
8855 {
8856   if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node
8857       && TREE_CODE (index) != INTEGER_CST)
8858     warning (OPT_Wchar_subscripts, "array subscript has type %<char%>");
8859 }
8860
8861 /* Implement -Wparentheses for the unexpected C precedence rules, to
8862    cover cases like x + y << z which readers are likely to
8863    misinterpret.  We have seen an expression in which CODE is a binary
8864    operator used to combine expressions ARG_LEFT and ARG_RIGHT, which
8865    before folding had CODE_LEFT and CODE_RIGHT.  CODE_LEFT and
8866    CODE_RIGHT may be ERROR_MARK, which means that that side of the
8867    expression was not formed using a binary or unary operator, or it
8868    was enclosed in parentheses.  */
8869
8870 void
8871 warn_about_parentheses (enum tree_code code,
8872                         enum tree_code code_left, tree arg_left,
8873                         enum tree_code code_right, tree arg_right)
8874 {
8875   if (!warn_parentheses)
8876     return;
8877
8878   /* This macro tests that the expression ARG with original tree code
8879      CODE appears to be a boolean expression. or the result of folding a
8880      boolean expression.  */
8881 #define APPEARS_TO_BE_BOOLEAN_EXPR_P(CODE, ARG)                             \
8882         (truth_value_p (TREE_CODE (ARG))                                    \
8883          || TREE_CODE (TREE_TYPE (ARG)) == BOOLEAN_TYPE                     \
8884          /* Folding may create 0 or 1 integers from other expressions.  */  \
8885          || ((CODE) != INTEGER_CST                                          \
8886              && (integer_onep (ARG) || integer_zerop (ARG))))
8887
8888   switch (code)
8889     {
8890     case LSHIFT_EXPR:
8891       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8892         warning (OPT_Wparentheses,
8893                  "suggest parentheses around %<+%> inside %<<<%>");
8894       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8895         warning (OPT_Wparentheses,
8896                  "suggest parentheses around %<-%> inside %<<<%>");
8897       return;
8898
8899     case RSHIFT_EXPR:
8900       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8901         warning (OPT_Wparentheses,
8902                  "suggest parentheses around %<+%> inside %<>>%>");
8903       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8904         warning (OPT_Wparentheses,
8905                  "suggest parentheses around %<-%> inside %<>>%>");
8906       return;
8907
8908     case TRUTH_ORIF_EXPR:
8909       if (code_left == TRUTH_ANDIF_EXPR || code_right == TRUTH_ANDIF_EXPR)
8910         warning (OPT_Wparentheses,
8911                  "suggest parentheses around %<&&%> within %<||%>");
8912       return;
8913
8914     case BIT_IOR_EXPR:
8915       if (code_left == BIT_AND_EXPR || code_left == BIT_XOR_EXPR
8916           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
8917           || code_right == BIT_AND_EXPR || code_right == BIT_XOR_EXPR
8918           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
8919         warning (OPT_Wparentheses,
8920                  "suggest parentheses around arithmetic in operand of %<|%>");
8921       /* Check cases like x|y==z */
8922       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8923                || TREE_CODE_CLASS (code_right) == tcc_comparison)
8924         warning (OPT_Wparentheses,
8925                  "suggest parentheses around comparison in operand of %<|%>");
8926       /* Check cases like !x | y */
8927       else if (code_left == TRUTH_NOT_EXPR
8928                && !APPEARS_TO_BE_BOOLEAN_EXPR_P (code_right, arg_right))
8929         warning (OPT_Wparentheses, "suggest parentheses around operand of "
8930                  "%<!%> or change %<|%> to %<||%> or %<!%> to %<~%>");
8931       return;
8932
8933     case BIT_XOR_EXPR:
8934       if (code_left == BIT_AND_EXPR
8935           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
8936           || code_right == BIT_AND_EXPR
8937           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
8938         warning (OPT_Wparentheses,
8939                  "suggest parentheses around arithmetic in operand of %<^%>");
8940       /* Check cases like x^y==z */
8941       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8942                || TREE_CODE_CLASS (code_right) == tcc_comparison)
8943         warning (OPT_Wparentheses,
8944                  "suggest parentheses around comparison in operand of %<^%>");
8945       return;
8946
8947     case BIT_AND_EXPR:
8948       if (code_left == PLUS_EXPR || code_right == PLUS_EXPR)
8949         warning (OPT_Wparentheses,
8950                  "suggest parentheses around %<+%> in operand of %<&%>");
8951       else if (code_left == MINUS_EXPR || code_right == MINUS_EXPR)
8952         warning (OPT_Wparentheses,
8953                  "suggest parentheses around %<-%> in operand of %<&%>");
8954       /* Check cases like x&y==z */
8955       else if (TREE_CODE_CLASS (code_left) == tcc_comparison
8956                || TREE_CODE_CLASS (code_right) == tcc_comparison)
8957         warning (OPT_Wparentheses,
8958                  "suggest parentheses around comparison in operand of %<&%>");
8959       /* Check cases like !x & y */
8960       else if (code_left == TRUTH_NOT_EXPR
8961                && !APPEARS_TO_BE_BOOLEAN_EXPR_P (code_right, arg_right))
8962         warning (OPT_Wparentheses, "suggest parentheses around operand of "
8963                  "%<!%> or change %<&%> to %<&&%> or %<!%> to %<~%>");
8964       return;
8965
8966     case EQ_EXPR:
8967       if (TREE_CODE_CLASS (code_left) == tcc_comparison
8968           || TREE_CODE_CLASS (code_right) == tcc_comparison)
8969         warning (OPT_Wparentheses,
8970                  "suggest parentheses around comparison in operand of %<==%>");
8971       return;
8972     case NE_EXPR:
8973       if (TREE_CODE_CLASS (code_left) == tcc_comparison
8974           || TREE_CODE_CLASS (code_right) == tcc_comparison)
8975         warning (OPT_Wparentheses,
8976                  "suggest parentheses around comparison in operand of %<!=%>");
8977       return;
8978
8979     default:
8980       if (TREE_CODE_CLASS (code) == tcc_comparison
8981            && ((TREE_CODE_CLASS (code_left) == tcc_comparison
8982                 && code_left != NE_EXPR && code_left != EQ_EXPR
8983                 && INTEGRAL_TYPE_P (TREE_TYPE (arg_left)))
8984                || (TREE_CODE_CLASS (code_right) == tcc_comparison
8985                    && code_right != NE_EXPR && code_right != EQ_EXPR
8986                    && INTEGRAL_TYPE_P (TREE_TYPE (arg_right)))))
8987         warning (OPT_Wparentheses, "comparisons like %<X<=Y<=Z%> do not "
8988                  "have their mathematical meaning");
8989       return;
8990     }
8991 #undef NOT_A_BOOLEAN_EXPR_P
8992 }
8993
8994 /* If LABEL (a LABEL_DECL) has not been used, issue a warning.  */
8995
8996 void
8997 warn_for_unused_label (tree label)
8998 {
8999   if (!TREE_USED (label))
9000     {
9001       if (DECL_INITIAL (label))
9002         warning (OPT_Wunused_label, "label %q+D defined but not used", label);
9003       else
9004         warning (OPT_Wunused_label, "label %q+D declared but not defined", label);
9005     }
9006 }
9007
9008 #ifndef TARGET_HAS_TARGETCM
9009 struct gcc_targetcm targetcm = TARGETCM_INITIALIZER;
9010 #endif
9011
9012 /* Warn for division by zero according to the value of DIVISOR.  LOC
9013    is the location of the division operator.  */
9014
9015 void
9016 warn_for_div_by_zero (location_t loc, tree divisor)
9017 {
9018   /* If DIVISOR is zero, and has integral or fixed-point type, issue a warning
9019      about division by zero.  Do not issue a warning if DIVISOR has a
9020      floating-point type, since we consider 0.0/0.0 a valid way of
9021      generating a NaN.  */
9022   if (c_inhibit_evaluation_warnings == 0
9023       && (integer_zerop (divisor) || fixed_zerop (divisor)))
9024     warning_at (loc, OPT_Wdiv_by_zero, "division by zero");
9025 }
9026
9027 /* Subroutine of build_binary_op. Give warnings for comparisons
9028    between signed and unsigned quantities that may fail. Do the
9029    checking based on the original operand trees ORIG_OP0 and ORIG_OP1,
9030    so that casts will be considered, but default promotions won't
9031    be.
9032
9033    LOCATION is the location of the comparison operator.
9034
9035    The arguments of this function map directly to local variables
9036    of build_binary_op.  */
9037
9038 void
9039 warn_for_sign_compare (location_t location,
9040                        tree orig_op0, tree orig_op1,
9041                        tree op0, tree op1,
9042                        tree result_type, enum tree_code resultcode)
9043 {
9044   int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
9045   int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
9046   int unsignedp0, unsignedp1;
9047
9048   /* In C++, check for comparison of different enum types.  */
9049   if (c_dialect_cxx()
9050       && TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
9051       && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
9052       && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
9053          != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
9054     {
9055       warning_at (location,
9056                   OPT_Wsign_compare, "comparison between types %qT and %qT",
9057                   TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
9058     }
9059
9060   /* Do not warn if the comparison is being done in a signed type,
9061      since the signed type will only be chosen if it can represent
9062      all the values of the unsigned type.  */
9063   if (!TYPE_UNSIGNED (result_type))
9064     /* OK */;
9065   /* Do not warn if both operands are unsigned.  */
9066   else if (op0_signed == op1_signed)
9067     /* OK */;
9068   else
9069     {
9070       tree sop, uop, base_type;
9071       bool ovf;
9072
9073       if (op0_signed)
9074         sop = orig_op0, uop = orig_op1;
9075       else
9076         sop = orig_op1, uop = orig_op0;
9077
9078       STRIP_TYPE_NOPS (sop);
9079       STRIP_TYPE_NOPS (uop);
9080       base_type = (TREE_CODE (result_type) == COMPLEX_TYPE
9081                    ? TREE_TYPE (result_type) : result_type);
9082
9083       /* Do not warn if the signed quantity is an unsuffixed integer
9084          literal (or some static constant expression involving such
9085          literals or a conditional expression involving such literals)
9086          and it is non-negative.  */
9087       if (tree_expr_nonnegative_warnv_p (sop, &ovf))
9088         /* OK */;
9089       /* Do not warn if the comparison is an equality operation, the
9090          unsigned quantity is an integral constant, and it would fit
9091          in the result if the result were signed.  */
9092       else if (TREE_CODE (uop) == INTEGER_CST
9093                && (resultcode == EQ_EXPR || resultcode == NE_EXPR)
9094                && int_fits_type_p (uop, c_common_signed_type (base_type)))
9095         /* OK */;
9096       /* In C, do not warn if the unsigned quantity is an enumeration
9097          constant and its maximum value would fit in the result if the
9098          result were signed.  */
9099       else if (!c_dialect_cxx() && TREE_CODE (uop) == INTEGER_CST
9100                && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE
9101                && int_fits_type_p (TYPE_MAX_VALUE (TREE_TYPE (uop)),
9102                                    c_common_signed_type (base_type)))
9103         /* OK */;
9104       else
9105         warning_at (location,
9106                     OPT_Wsign_compare,
9107                     "comparison between signed and unsigned integer expressions");
9108     }
9109
9110   /* Warn if two unsigned values are being compared in a size larger
9111      than their original size, and one (and only one) is the result of
9112      a `~' operator.  This comparison will always fail.
9113
9114      Also warn if one operand is a constant, and the constant does not
9115      have all bits set that are set in the ~ operand when it is
9116      extended.  */
9117
9118   op0 = get_narrower (op0, &unsignedp0);
9119   op1 = get_narrower (op1, &unsignedp1);
9120
9121   if ((TREE_CODE (op0) == BIT_NOT_EXPR)
9122       ^ (TREE_CODE (op1) == BIT_NOT_EXPR))
9123     {
9124       if (TREE_CODE (op0) == BIT_NOT_EXPR)
9125         op0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
9126       if (TREE_CODE (op1) == BIT_NOT_EXPR)
9127         op1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
9128
9129       if (host_integerp (op0, 0) || host_integerp (op1, 0))
9130         {
9131           tree primop;
9132           HOST_WIDE_INT constant, mask;
9133           int unsignedp;
9134           unsigned int bits;
9135
9136           if (host_integerp (op0, 0))
9137             {
9138               primop = op1;
9139               unsignedp = unsignedp1;
9140               constant = tree_low_cst (op0, 0);
9141             }
9142           else
9143             {
9144               primop = op0;
9145               unsignedp = unsignedp0;
9146               constant = tree_low_cst (op1, 0);
9147             }
9148
9149           bits = TYPE_PRECISION (TREE_TYPE (primop));
9150           if (bits < TYPE_PRECISION (result_type)
9151               && bits < HOST_BITS_PER_LONG && unsignedp)
9152             {
9153               mask = (~ (HOST_WIDE_INT) 0) << bits;
9154               if ((mask & constant) != mask)
9155                 {
9156                   if (constant == 0)
9157                     warning (OPT_Wsign_compare,
9158                              "promoted ~unsigned is always non-zero");
9159                   else
9160                     warning_at (location, OPT_Wsign_compare,
9161                                 "comparison of promoted ~unsigned with constant");
9162                 }
9163             }
9164         }
9165       else if (unsignedp0 && unsignedp1
9166                && (TYPE_PRECISION (TREE_TYPE (op0))
9167                    < TYPE_PRECISION (result_type))
9168                && (TYPE_PRECISION (TREE_TYPE (op1))
9169                    < TYPE_PRECISION (result_type)))
9170         warning_at (location, OPT_Wsign_compare,
9171                  "comparison of promoted ~unsigned with unsigned");
9172     }
9173 }
9174
9175 /* Setup a TYPE_DECL node as a typedef representation.
9176
9177    X is a TYPE_DECL for a typedef statement.  Create a brand new
9178    ..._TYPE node (which will be just a variant of the existing
9179    ..._TYPE node with identical properties) and then install X
9180    as the TYPE_NAME of this brand new (duplicate) ..._TYPE node.
9181
9182    The whole point here is to end up with a situation where each
9183    and every ..._TYPE node the compiler creates will be uniquely
9184    associated with AT MOST one node representing a typedef name.
9185    This way, even though the compiler substitutes corresponding
9186    ..._TYPE nodes for TYPE_DECL (i.e. "typedef name") nodes very
9187    early on, later parts of the compiler can always do the reverse
9188    translation and get back the corresponding typedef name.  For
9189    example, given:
9190
9191         typedef struct S MY_TYPE;
9192         MY_TYPE object;
9193
9194    Later parts of the compiler might only know that `object' was of
9195    type `struct S' if it were not for code just below.  With this
9196    code however, later parts of the compiler see something like:
9197
9198         struct S' == struct S
9199         typedef struct S' MY_TYPE;
9200         struct S' object;
9201
9202     And they can then deduce (from the node for type struct S') that
9203     the original object declaration was:
9204
9205                 MY_TYPE object;
9206
9207     Being able to do this is important for proper support of protoize,
9208     and also for generating precise symbolic debugging information
9209     which takes full account of the programmer's (typedef) vocabulary.
9210
9211     Obviously, we don't want to generate a duplicate ..._TYPE node if
9212     the TYPE_DECL node that we are now processing really represents a
9213     standard built-in type.  */
9214
9215 void
9216 set_underlying_type (tree x)
9217 {
9218   if (x == error_mark_node)
9219     return;
9220   if (DECL_IS_BUILTIN (x))
9221     {
9222       if (TYPE_NAME (TREE_TYPE (x)) == 0)
9223         TYPE_NAME (TREE_TYPE (x)) = x;
9224     }
9225   else if (TREE_TYPE (x) != error_mark_node
9226            && DECL_ORIGINAL_TYPE (x) == NULL_TREE)
9227     {
9228       tree tt = TREE_TYPE (x);
9229       DECL_ORIGINAL_TYPE (x) = tt;
9230       tt = build_variant_type_copy (tt);
9231       TYPE_STUB_DECL (tt) = TYPE_STUB_DECL (DECL_ORIGINAL_TYPE (x));
9232       TYPE_NAME (tt) = x;
9233       TREE_USED (tt) = TREE_USED (x);
9234       TREE_TYPE (x) = tt;
9235     }
9236 }
9237
9238 /* Returns true if X is a typedef decl.  */
9239
9240 bool
9241 is_typedef_decl (tree x)
9242 {
9243   return (x && TREE_CODE (x) == TYPE_DECL
9244           && DECL_ORIGINAL_TYPE (x) != NULL_TREE);
9245 }
9246
9247 /* Record the types used by the current global variable declaration
9248    being parsed, so that we can decide later to emit their debug info.
9249    Those types are in types_used_by_cur_var_decl, and we are going to
9250    store them in the types_used_by_vars_hash hash table.
9251    DECL is the declaration of the global variable that has been parsed.  */
9252
9253 void
9254 record_types_used_by_current_var_decl (tree decl)
9255 {
9256   gcc_assert (decl && DECL_P (decl) && TREE_STATIC (decl));
9257
9258   if (types_used_by_cur_var_decl)
9259     {
9260       tree node;
9261       for (node = types_used_by_cur_var_decl;
9262            node;
9263            node = TREE_CHAIN (node))
9264       {
9265         tree type = TREE_PURPOSE (node);
9266         types_used_by_var_decl_insert (type, decl);
9267       }
9268       types_used_by_cur_var_decl = NULL;
9269     }
9270 }
9271
9272 /* The C and C++ parsers both use vectors to hold function arguments.
9273    For efficiency, we keep a cache of unused vectors.  This is the
9274    cache.  */
9275
9276 typedef VEC(tree,gc)* tree_gc_vec;
9277 DEF_VEC_P(tree_gc_vec);
9278 DEF_VEC_ALLOC_P(tree_gc_vec,gc);
9279 static GTY((deletable)) VEC(tree_gc_vec,gc) *tree_vector_cache;
9280
9281 /* Return a new vector from the cache.  If the cache is empty,
9282    allocate a new vector.  These vectors are GC'ed, so it is OK if the
9283    pointer is not released..  */
9284
9285 VEC(tree,gc) *
9286 make_tree_vector (void)
9287 {
9288   if (!VEC_empty (tree_gc_vec, tree_vector_cache))
9289     return VEC_pop (tree_gc_vec, tree_vector_cache);
9290   else
9291     {
9292       /* Passing 0 to VEC_alloc returns NULL, and our callers require
9293          that we always return a non-NULL value.  The vector code uses
9294          4 when growing a NULL vector, so we do too.  */
9295       return VEC_alloc (tree, gc, 4);
9296     }
9297 }
9298
9299 /* Release a vector of trees back to the cache.  */
9300
9301 void
9302 release_tree_vector (VEC(tree,gc) *vec)
9303 {
9304   if (vec != NULL)
9305     {
9306       VEC_truncate (tree, vec, 0);
9307       VEC_safe_push (tree_gc_vec, gc, tree_vector_cache, vec);
9308     }
9309 }
9310
9311 /* Get a new tree vector holding a single tree.  */
9312
9313 VEC(tree,gc) *
9314 make_tree_vector_single (tree t)
9315 {
9316   VEC(tree,gc) *ret = make_tree_vector ();
9317   VEC_quick_push (tree, ret, t);
9318   return ret;
9319 }
9320
9321 /* Get a new tree vector which is a copy of an existing one.  */
9322
9323 VEC(tree,gc) *
9324 make_tree_vector_copy (const VEC(tree,gc) *orig)
9325 {
9326   VEC(tree,gc) *ret;
9327   unsigned int ix;
9328   tree t;
9329
9330   ret = make_tree_vector ();
9331   VEC_reserve (tree, gc, ret, VEC_length (tree, orig));
9332   for (ix = 0; VEC_iterate (tree, orig, ix, t); ++ix)
9333     VEC_quick_push (tree, ret, t);
9334   return ret;
9335 }
9336
9337 #include "gt-c-common.h"