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 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "tm.h"
  25 #include "intl.h"
  26 #include "tree.h"
  27 #include "flags.h"
  28 #include "output.h"
  29 #include "c-pragma.h"
  30 #include "rtl.h"
  31 #include "ggc.h"
  32 #include "varray.h"
  33 #include "expr.h"
  34 #include "c-common.h"
  35 #include "diagnostic.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 "tree-iterator.h"
  45 #include "hashtab.h"
  46 #include "tree-mudflap.h"
  47 #include "opts.h"
  48 #include "real.h"
  49 #include "cgraph.h"
  50 #include "target-def.h"
  51 #include "fixed-value.h"
  52
  53 cpp_reader *parse_in;           /* Declared in c-pragma.h.  */
  54
  55 /* We let tm.h override the types used here, to handle trivial differences
  56    such as the choice of unsigned int or long unsigned int for size_t.
  57    When machines start needing nontrivial differences in the size type,
  58    it would be best to do something here to figure out automatically
  59    from other information what type to use.  */
  60
  61 #ifndef SIZE_TYPE
  62 #define SIZE_TYPE "long unsigned int"
  63 #endif
  64
  65 #ifndef PID_TYPE
  66 #define PID_TYPE "int"
  67 #endif
  68
  69 #ifndef WCHAR_TYPE
  70 #define WCHAR_TYPE "int"
  71 #endif
  72
  73 /* WCHAR_TYPE gets overridden by -fshort-wchar.  */
  74 #define MODIFIED_WCHAR_TYPE \
  75         (flag_short_wchar ? "short unsigned int" : WCHAR_TYPE)
  76
  77 #ifndef PTRDIFF_TYPE
  78 #define PTRDIFF_TYPE "long int"
  79 #endif
  80
  81 #ifndef WINT_TYPE
  82 #define WINT_TYPE "unsigned int"
  83 #endif
  84
  85 #ifndef INTMAX_TYPE
  86 #define INTMAX_TYPE ((INT_TYPE_SIZE == LONG_LONG_TYPE_SIZE)     \
  87                      ? "int"                                    \
  88                      : ((LONG_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \
  89                         ? "long int"                            \
  90                         : "long long int"))
  91 #endif
  92
  93 #ifndef UINTMAX_TYPE
  94 #define UINTMAX_TYPE ((INT_TYPE_SIZE == LONG_LONG_TYPE_SIZE)    \
  95                      ? "unsigned int"                           \
  96                      : ((LONG_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \
  97                         ? "long unsigned int"                   \
  98                         : "long long unsigned int"))
  99 #endif
 100
 101 /* The following symbols are subsumed in the c_global_trees array, and
 102    listed here individually for documentation purposes.
 103
 104    INTEGER_TYPE and REAL_TYPE nodes for the standard data types.
 105
 106         tree short_integer_type_node;
 107         tree long_integer_type_node;
 108         tree long_long_integer_type_node;
 109
 110         tree short_unsigned_type_node;
 111         tree long_unsigned_type_node;
 112         tree long_long_unsigned_type_node;
 113
 114         tree truthvalue_type_node;
 115         tree truthvalue_false_node;
 116         tree truthvalue_true_node;
 117
 118         tree ptrdiff_type_node;
 119
 120         tree unsigned_char_type_node;
 121         tree signed_char_type_node;
 122         tree wchar_type_node;
 123         tree signed_wchar_type_node;
 124         tree unsigned_wchar_type_node;
 125
 126         tree float_type_node;
 127         tree double_type_node;
 128         tree long_double_type_node;
 129
 130         tree complex_integer_type_node;
 131         tree complex_float_type_node;
 132         tree complex_double_type_node;
 133         tree complex_long_double_type_node;
 134
 135         tree dfloat32_type_node;
 136         tree dfloat64_type_node;
 137         tree_dfloat128_type_node;
 138
 139         tree intQI_type_node;
 140         tree intHI_type_node;
 141         tree intSI_type_node;
 142         tree intDI_type_node;
 143         tree intTI_type_node;
 144
 145         tree unsigned_intQI_type_node;
 146         tree unsigned_intHI_type_node;
 147         tree unsigned_intSI_type_node;
 148         tree unsigned_intDI_type_node;
 149         tree unsigned_intTI_type_node;
 150
 151         tree widest_integer_literal_type_node;
 152         tree widest_unsigned_literal_type_node;
 153
 154    Nodes for types `void *' and `const void *'.
 155
 156         tree ptr_type_node, const_ptr_type_node;
 157
 158    Nodes for types `char *' and `const char *'.
 159
 160         tree string_type_node, const_string_type_node;
 161
 162    Type `char[SOMENUMBER]'.
 163    Used when an array of char is needed and the size is irrelevant.
 164
 165         tree char_array_type_node;
 166
 167    Type `int[SOMENUMBER]' or something like it.
 168    Used when an array of int needed and the size is irrelevant.
 169
 170         tree int_array_type_node;
 171
 172    Type `wchar_t[SOMENUMBER]' or something like it.
 173    Used when a wide string literal is created.
 174
 175         tree wchar_array_type_node;
 176
 177    Type `int ()' -- used for implicit declaration of functions.
 178
 179         tree default_function_type;
 180
 181    A VOID_TYPE node, packaged in a TREE_LIST.
 182
 183         tree void_list_node;
 184
 185   The lazily created VAR_DECLs for __FUNCTION__, __PRETTY_FUNCTION__,
 186   and __func__. (C doesn't generate __FUNCTION__ and__PRETTY_FUNCTION__
 187   VAR_DECLS, but C++ does.)
 188
 189         tree function_name_decl_node;
 190         tree pretty_function_name_decl_node;
 191         tree c99_function_name_decl_node;
 192
 193   Stack of nested function name VAR_DECLs.
 194
 195         tree saved_function_name_decls;
 196
 197 */
 198
 199 tree c_global_trees[CTI_MAX];
 200 \f
 201 /* Switches common to the C front ends.  */
 202
 203 /* Nonzero if prepreprocessing only.  */
 204
 205 int flag_preprocess_only;
 206
 207 /* Nonzero means don't output line number information.  */
 208
 209 char flag_no_line_commands;
 210
 211 /* Nonzero causes -E output not to be done, but directives such as
 212    #define that have side effects are still obeyed.  */
 213
 214 char flag_no_output;
 215
 216 /* Nonzero means dump macros in some fashion.  */
 217
 218 char flag_dump_macros;
 219
 220 /* Nonzero means pass #include lines through to the output.  */
 221
 222 char flag_dump_includes;
 223
 224 /* Nonzero means process PCH files while preprocessing.  */
 225
 226 bool flag_pch_preprocess;
 227
 228 /* The file name to which we should write a precompiled header, or
 229    NULL if no header will be written in this compile.  */
 230
 231 const char *pch_file;
 232
 233 /* Nonzero if an ISO standard was selected.  It rejects macros in the
 234    user's namespace.  */
 235 int flag_iso;
 236
 237 /* Nonzero if -undef was given.  It suppresses target built-in macros
 238    and assertions.  */
 239 int flag_undef;
 240
 241 /* Nonzero means don't recognize the non-ANSI builtin functions.  */
 242
 243 int flag_no_builtin;
 244
 245 /* Nonzero means don't recognize the non-ANSI builtin functions.
 246    -ansi sets this.  */
 247
 248 int flag_no_nonansi_builtin;
 249
 250 /* Nonzero means give `double' the same size as `float'.  */
 251
 252 int flag_short_double;
 253
 254 /* Nonzero means give `wchar_t' the same size as `short'.  */
 255
 256 int flag_short_wchar;
 257
 258 /* Nonzero means allow implicit conversions between vectors with
 259    differing numbers of subparts and/or differing element types.  */
 260 int flag_lax_vector_conversions;
 261
 262 /* Nonzero means allow Microsoft extensions without warnings or errors.  */
 263 int flag_ms_extensions;
 264
 265 /* Nonzero means don't recognize the keyword `asm'.  */
 266
 267 int flag_no_asm;
 268
 269 /* Nonzero means to treat bitfields as signed unless they say `unsigned'.  */
 270
 271 int flag_signed_bitfields = 1;
 272
 273 /* Warn about #pragma directives that are not recognized.  */
 274
 275 int warn_unknown_pragmas; /* Tri state variable.  */
 276
 277 /* Warn about format/argument anomalies in calls to formatted I/O functions
 278    (*printf, *scanf, strftime, strfmon, etc.).  */
 279
 280 int warn_format;
 281
 282 /* Warn about using __null (as NULL in C++) as sentinel.  For code compiled
 283    with GCC this doesn't matter as __null is guaranteed to have the right
 284    size.  */
 285
 286 int warn_strict_null_sentinel;
 287
 288 /* Zero means that faster, ...NonNil variants of objc_msgSend...
 289    calls will be used in ObjC; passing nil receivers to such calls
 290    will most likely result in crashes.  */
 291 int flag_nil_receivers = 1;
 292
 293 /* Nonzero means that code generation will be altered to support
 294    "zero-link" execution.  This currently affects ObjC only, but may
 295    affect other languages in the future.  */
 296 int flag_zero_link = 0;
 297
 298 /* Nonzero means emit an '__OBJC, __image_info' for the current translation
 299    unit.  It will inform the ObjC runtime that class definition(s) herein
 300    contained are to replace one(s) previously loaded.  */
 301 int flag_replace_objc_classes = 0;
 302
 303 /* C/ObjC language option variables.  */
 304
 305
 306 /* Nonzero means allow type mismatches in conditional expressions;
 307    just make their values `void'.  */
 308
 309 int flag_cond_mismatch;
 310
 311 /* Nonzero means enable C89 Amendment 1 features.  */
 312
 313 int flag_isoc94;
 314
 315 /* Nonzero means use the ISO C99 dialect of C.  */
 316
 317 int flag_isoc99;
 318
 319 /* Nonzero means that we have builtin functions, and main is an int.  */
 320
 321 int flag_hosted = 1;
 322
 323 /* Warn if main is suspicious.  */
 324
 325 int warn_main;
 326
 327
 328 /* ObjC language option variables.  */
 329
 330
 331 /* Open and close the file for outputting class declarations, if
 332    requested (ObjC).  */
 333
 334 int flag_gen_declaration;
 335
 336 /* Tells the compiler that this is a special run.  Do not perform any
 337    compiling, instead we are to test some platform dependent features
 338    and output a C header file with appropriate definitions.  */
 339
 340 int print_struct_values;
 341
 342 /* Tells the compiler what is the constant string class for Objc.  */
 343
 344 const char *constant_string_class_name;
 345
 346
 347 /* C++ language option variables.  */
 348
 349
 350 /* Nonzero means don't recognize any extension keywords.  */
 351
 352 int flag_no_gnu_keywords;
 353
 354 /* Nonzero means do emit exported implementations of functions even if
 355    they can be inlined.  */
 356
 357 int flag_implement_inlines = 1;
 358
 359 /* Nonzero means that implicit instantiations will be emitted if needed.  */
 360
 361 int flag_implicit_templates = 1;
 362
 363 /* Nonzero means that implicit instantiations of inline templates will be
 364    emitted if needed, even if instantiations of non-inline templates
 365    aren't.  */
 366
 367 int flag_implicit_inline_templates = 1;
 368
 369 /* Nonzero means generate separate instantiation control files and
 370    juggle them at link time.  */
 371
 372 int flag_use_repository;
 373
 374 /* Nonzero if we want to issue diagnostics that the standard says are not
 375    required.  */
 376
 377 int flag_optional_diags = 1;
 378
 379 /* Nonzero means we should attempt to elide constructors when possible.  */
 380
 381 int flag_elide_constructors = 1;
 382
 383 /* Nonzero means that member functions defined in class scope are
 384    inline by default.  */
 385
 386 int flag_default_inline = 1;
 387
 388 /* Controls whether compiler generates 'type descriptor' that give
 389    run-time type information.  */
 390
 391 int flag_rtti = 1;
 392
 393 /* Nonzero if we want to conserve space in the .o files.  We do this
 394    by putting uninitialized data and runtime initialized data into
 395    .common instead of .data at the expense of not flagging multiple
 396    definitions.  */
 397
 398 int flag_conserve_space;
 399
 400 /* Nonzero if we want to obey access control semantics.  */
 401
 402 int flag_access_control = 1;
 403
 404 /* Nonzero if we want to check the return value of new and avoid calling
 405    constructors if it is a null pointer.  */
 406
 407 int flag_check_new;
 408
 409 /* The C++ dialect being used. C++98 is the default.  */
 410
 411 enum cxx_dialect cxx_dialect = cxx98;
 412
 413 /* Nonzero if we want the new ISO rules for pushing a new scope for `for'
 414    initialization variables.
 415    0: Old rules, set by -fno-for-scope.
 416    2: New ISO rules, set by -ffor-scope.
 417    1: Try to implement new ISO rules, but with backup compatibility
 418    (and warnings).  This is the default, for now.  */
 419
 420 int flag_new_for_scope = 1;
 421
 422 /* Nonzero if we want to emit defined symbols with common-like linkage as
 423    weak symbols where possible, in order to conform to C++ semantics.
 424    Otherwise, emit them as local symbols.  */
 425
 426 int flag_weak = 1;
 427
 428 /* 0 means we want the preprocessor to not emit line directives for
 429    the current working directory.  1 means we want it to do it.  -1
 430    means we should decide depending on whether debugging information
 431    is being emitted or not.  */
 432
 433 int flag_working_directory = -1;
 434
 435 /* Nonzero to use __cxa_atexit, rather than atexit, to register
 436    destructors for local statics and global objects.  '2' means it has been
 437    set nonzero as a default, not by a command-line flag.  */
 438
 439 int flag_use_cxa_atexit = DEFAULT_USE_CXA_ATEXIT;
 440
 441 /* Nonzero to use __cxa_get_exception_ptr in C++ exception-handling
 442    code.  '2' means it has not been set explicitly on the command line.  */
 443
 444 int flag_use_cxa_get_exception_ptr = 2;
 445
 446 /* Nonzero means to implement standard semantics for exception
 447    specifications, calling unexpected if an exception is thrown that
 448    doesn't match the specification.  Zero means to treat them as
 449    assertions and optimize accordingly, but not check them.  */
 450
 451 int flag_enforce_eh_specs = 1;
 452
 453 /* Nonzero means to generate thread-safe code for initializing local
 454    statics.  */
 455
 456 int flag_threadsafe_statics = 1;
 457
 458 /* Nonzero means warn about implicit declarations.  */
 459
 460 int warn_implicit = 1;
 461
 462 /* Maximum template instantiation depth.  This limit is rather
 463    arbitrary, but it exists to limit the time it takes to notice
 464    infinite template instantiations.  */
 465
 466 int max_tinst_depth = 500;
 467
 468
 469
 470 /* The elements of `ridpointers' are identifier nodes for the reserved
 471    type names and storage classes.  It is indexed by a RID_... value.  */
 472 tree *ridpointers;
 473
 474 tree (*make_fname_decl) (tree, int);
 475
 476 /* Nonzero means the expression being parsed will never be evaluated.
 477    This is a count, since unevaluated expressions can nest.  */
 478 int skip_evaluation;
 479
 480 /* Information about how a function name is generated.  */
 481 struct fname_var_t
 482 {
 483   tree *const decl;     /* pointer to the VAR_DECL.  */
 484   const unsigned rid;   /* RID number for the identifier.  */
 485   const int pretty;     /* How pretty is it? */
 486 };
 487
 488 /* The three ways of getting then name of the current function.  */
 489
 490 const struct fname_var_t fname_vars[] =
 491 {
 492   /* C99 compliant __func__, must be first.  */
 493   {&c99_function_name_decl_node, RID_C99_FUNCTION_NAME, 0},
 494   /* GCC __FUNCTION__ compliant.  */
 495   {&function_name_decl_node, RID_FUNCTION_NAME, 0},
 496   /* GCC __PRETTY_FUNCTION__ compliant.  */
 497   {&pretty_function_name_decl_node, RID_PRETTY_FUNCTION_NAME, 1},
 498   {NULL, 0, 0},
 499 };
 500
 501 static tree check_case_value (tree);
 502 static bool check_case_bounds (tree, tree, tree *, tree *);
 503
 504 static tree handle_packed_attribute (tree *, tree, tree, int, bool *);
 505 static tree handle_nocommon_attribute (tree *, tree, tree, int, bool *);
 506 static tree handle_common_attribute (tree *, tree, tree, int, bool *);
 507 static tree handle_noreturn_attribute (tree *, tree, tree, int, bool *);
 508 static tree handle_hot_attribute (tree *, tree, tree, int, bool *);
 509 static tree handle_cold_attribute (tree *, tree, tree, int, bool *);
 510 static tree handle_noinline_attribute (tree *, tree, tree, int, bool *);
 511 static tree handle_always_inline_attribute (tree *, tree, tree, int,
 512                                             bool *);
 513 static tree handle_gnu_inline_attribute (tree *, tree, tree, int, bool *);
 514 static tree handle_artificial_attribute (tree *, tree, tree, int, bool *);
 515 static tree handle_flatten_attribute (tree *, tree, tree, int, bool *);
 516 static tree handle_error_attribute (tree *, tree, tree, int, bool *);
 517 static tree handle_used_attribute (tree *, tree, tree, int, bool *);
 518 static tree handle_unused_attribute (tree *, tree, tree, int, bool *);
 519 static tree handle_externally_visible_attribute (tree *, tree, tree, int,
 520                                                  bool *);
 521 static tree handle_const_attribute (tree *, tree, tree, int, bool *);
 522 static tree handle_transparent_union_attribute (tree *, tree, tree,
 523                                                 int, bool *);
 524 static tree handle_constructor_attribute (tree *, tree, tree, int, bool *);
 525 static tree handle_destructor_attribute (tree *, tree, tree, int, bool *);
 526 static tree handle_mode_attribute (tree *, tree, tree, int, bool *);
 527 static tree handle_section_attribute (tree *, tree, tree, int, bool *);
 528 static tree handle_aligned_attribute (tree *, tree, tree, int, bool *);
 529 static tree handle_weak_attribute (tree *, tree, tree, int, bool *) ;
 530 static tree handle_alias_attribute (tree *, tree, tree, int, bool *);
 531 static tree handle_weakref_attribute (tree *, tree, tree, int, bool *) ;
 532 static tree handle_visibility_attribute (tree *, tree, tree, int,
 533                                          bool *);
 534 static tree handle_tls_model_attribute (tree *, tree, tree, int,
 535                                         bool *);
 536 static tree handle_no_instrument_function_attribute (tree *, tree,
 537                                                      tree, int, bool *);
 538 static tree handle_malloc_attribute (tree *, tree, tree, int, bool *);
 539 static tree handle_returns_twice_attribute (tree *, tree, tree, int, bool *);
 540 static tree handle_no_limit_stack_attribute (tree *, tree, tree, int,
 541                                              bool *);
 542 static tree handle_pure_attribute (tree *, tree, tree, int, bool *);
 543 static tree handle_novops_attribute (tree *, tree, tree, int, bool *);
 544 static tree handle_deprecated_attribute (tree *, tree, tree, int,
 545                                          bool *);
 546 static tree handle_vector_size_attribute (tree *, tree, tree, int,
 547                                           bool *);
 548 static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *);
 549 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
 550 static tree handle_cleanup_attribute (tree *, tree, tree, int, bool *);
 551 static tree handle_warn_unused_result_attribute (tree *, tree, tree, int,
 552                                                  bool *);
 553 static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *);
 554 static tree handle_type_generic_attribute (tree *, tree, tree, int, bool *);
 555 static tree handle_alloc_size_attribute (tree *, tree, tree, int, bool *);
 556
 557 static void check_function_nonnull (tree, int, tree *);
 558 static void check_nonnull_arg (void *, tree, unsigned HOST_WIDE_INT);
 559 static bool nonnull_check_p (tree, unsigned HOST_WIDE_INT);
 560 static bool get_nonnull_operand (tree, unsigned HOST_WIDE_INT *);
 561 static int resort_field_decl_cmp (const void *, const void *);
 562
 563 /* Table of machine-independent attributes common to all C-like languages.  */
 564 const struct attribute_spec c_common_attribute_table[] =
 565 {
 566   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 567   { "packed",                 0, 0, false, false, false,
 568                               handle_packed_attribute },
 569   { "nocommon",               0, 0, true,  false, false,
 570                               handle_nocommon_attribute },
 571   { "common",                 0, 0, true,  false, false,
 572                               handle_common_attribute },
 573   /* FIXME: logically, noreturn attributes should be listed as
 574      "false, true, true" and apply to function types.  But implementing this
 575      would require all the places in the compiler that use TREE_THIS_VOLATILE
 576      on a decl to identify non-returning functions to be located and fixed
 577      to check the function type instead.  */
 578   { "noreturn",               0, 0, true,  false, false,
 579                               handle_noreturn_attribute },
 580   { "volatile",               0, 0, true,  false, false,
 581                               handle_noreturn_attribute },
 582   { "noinline",               0, 0, true,  false, false,
 583                               handle_noinline_attribute },
 584   { "always_inline",          0, 0, true,  false, false,
 585                               handle_always_inline_attribute },
 586   { "gnu_inline",             0, 0, true,  false, false,
 587                               handle_gnu_inline_attribute },
 588   { "artificial",             0, 0, true,  false, false,
 589                               handle_artificial_attribute },
 590   { "flatten",                0, 0, true,  false, false,
 591                               handle_flatten_attribute },
 592   { "used",                   0, 0, true,  false, false,
 593                               handle_used_attribute },
 594   { "unused",                 0, 0, false, false, false,
 595                               handle_unused_attribute },
 596   { "externally_visible",     0, 0, true,  false, false,
 597                               handle_externally_visible_attribute },
 598   /* The same comments as for noreturn attributes apply to const ones.  */
 599   { "const",                  0, 0, true,  false, false,
 600                               handle_const_attribute },
 601   { "transparent_union",      0, 0, false, false, false,
 602                               handle_transparent_union_attribute },
 603   { "constructor",            0, 1, true,  false, false,
 604                               handle_constructor_attribute },
 605   { "destructor",             0, 1, true,  false, false,
 606                               handle_destructor_attribute },
 607   { "mode",                   1, 1, false,  true, false,
 608                               handle_mode_attribute },
 609   { "section",                1, 1, true,  false, false,
 610                               handle_section_attribute },
 611   { "aligned",                0, 1, false, false, false,
 612                               handle_aligned_attribute },
 613   { "weak",                   0, 0, true,  false, false,
 614                               handle_weak_attribute },
 615   { "alias",                  1, 1, true,  false, false,
 616                               handle_alias_attribute },
 617   { "weakref",                0, 1, true,  false, false,
 618                               handle_weakref_attribute },
 619   { "no_instrument_function", 0, 0, true,  false, false,
 620                               handle_no_instrument_function_attribute },
 621   { "malloc",                 0, 0, true,  false, false,
 622                               handle_malloc_attribute },
 623   { "returns_twice",          0, 0, true,  false, false,
 624                               handle_returns_twice_attribute },
 625   { "no_stack_limit",         0, 0, true,  false, false,
 626                               handle_no_limit_stack_attribute },
 627   { "pure",                   0, 0, true,  false, false,
 628                               handle_pure_attribute },
 629   /* For internal use (marking of builtins) only.  The name contains space
 630      to prevent its usage in source code.  */
 631   { "no vops",                0, 0, true,  false, false,
 632                               handle_novops_attribute },
 633   { "deprecated",             0, 0, false, false, false,
 634                               handle_deprecated_attribute },
 635   { "vector_size",            1, 1, false, true, false,
 636                               handle_vector_size_attribute },
 637   { "visibility",             1, 1, false, false, false,
 638                               handle_visibility_attribute },
 639   { "tls_model",              1, 1, true,  false, false,
 640                               handle_tls_model_attribute },
 641   { "nonnull",                0, -1, false, true, true,
 642                               handle_nonnull_attribute },
 643   { "nothrow",                0, 0, true,  false, false,
 644                               handle_nothrow_attribute },
 645   { "may_alias",              0, 0, false, true, false, NULL },
 646   { "cleanup",                1, 1, true, false, false,
 647                               handle_cleanup_attribute },
 648   { "warn_unused_result",     0, 0, false, true, true,
 649                               handle_warn_unused_result_attribute },
 650   { "sentinel",               0, 1, false, true, true,
 651                               handle_sentinel_attribute },
 652   /* For internal use (marking of builtins) only.  The name contains space
 653      to prevent its usage in source code.  */
 654   { "type generic",           0, 0, false, true, true,
 655                               handle_type_generic_attribute },
 656   { "alloc_size",             1, 2, false, true, true,
 657                               handle_alloc_size_attribute },
 658   { "cold",                   0, 0, true,  false, false,
 659                               handle_cold_attribute },
 660   { "hot",                    0, 0, true,  false, false,
 661                               handle_hot_attribute },
 662   { "warning",                1, 1, true,  false, false,
 663                               handle_error_attribute },
 664   { "error",                  1, 1, true,  false, false,
 665                               handle_error_attribute },
 666   { NULL,                     0, 0, false, false, false, NULL }
 667 };
 668
 669 /* Give the specifications for the format attributes, used by C and all
 670    descendants.  */
 671
 672 const struct attribute_spec c_common_format_attribute_table[] =
 673 {
 674   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 675   { "format",                 3, 3, false, true,  true,
 676                               handle_format_attribute },
 677   { "format_arg",             1, 1, false, true,  true,
 678                               handle_format_arg_attribute },
 679   { NULL,                     0, 0, false, false, false, NULL }
 680 };
 681
 682 /* Push current bindings for the function name VAR_DECLS.  */
 683
 684 void
 685 start_fname_decls (void)
 686 {
 687   unsigned ix;
 688   tree saved = NULL_TREE;
 689
 690   for (ix = 0; fname_vars[ix].decl; ix++)
 691     {
 692       tree decl = *fname_vars[ix].decl;
 693
 694       if (decl)
 695         {
 696           saved = tree_cons (decl, build_int_cst (NULL_TREE, ix), saved);
 697           *fname_vars[ix].decl = NULL_TREE;
 698         }
 699     }
 700   if (saved || saved_function_name_decls)
 701     /* Normally they'll have been NULL, so only push if we've got a
 702        stack, or they are non-NULL.  */
 703     saved_function_name_decls = tree_cons (saved, NULL_TREE,
 704                                            saved_function_name_decls);
 705 }
 706
 707 /* Finish up the current bindings, adding them into the current function's
 708    statement tree.  This must be done _before_ finish_stmt_tree is called.
 709    If there is no current function, we must be at file scope and no statements
 710    are involved. Pop the previous bindings.  */
 711
 712 void
 713 finish_fname_decls (void)
 714 {
 715   unsigned ix;
 716   tree stmts = NULL_TREE;
 717   tree stack = saved_function_name_decls;
 718
 719   for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack))
 720     append_to_statement_list (TREE_VALUE (stack), &stmts);
 721
 722   if (stmts)
 723     {
 724       tree *bodyp = &DECL_SAVED_TREE (current_function_decl);
 725
 726       if (TREE_CODE (*bodyp) == BIND_EXPR)
 727         bodyp = &BIND_EXPR_BODY (*bodyp);
 728
 729       append_to_statement_list_force (*bodyp, &stmts);
 730       *bodyp = stmts;
 731     }
 732
 733   for (ix = 0; fname_vars[ix].decl; ix++)
 734     *fname_vars[ix].decl = NULL_TREE;
 735
 736   if (stack)
 737     {
 738       /* We had saved values, restore them.  */
 739       tree saved;
 740
 741       for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved))
 742         {
 743           tree decl = TREE_PURPOSE (saved);
 744           unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved));
 745
 746           *fname_vars[ix].decl = decl;
 747         }
 748       stack = TREE_CHAIN (stack);
 749     }
 750   saved_function_name_decls = stack;
 751 }
 752
 753 /* Return the text name of the current function, suitably prettified
 754    by PRETTY_P.  Return string must be freed by caller.  */
 755
 756 const char *
 757 fname_as_string (int pretty_p)
 758 {
 759   const char *name = "top level";
 760   char *namep;
 761   int vrb = 2, len;
 762   cpp_string cstr = { 0, 0 }, strname;
 763
 764   if (!pretty_p)
 765     {
 766       name = "";
 767       vrb = 0;
 768     }
 769
 770   if (current_function_decl)
 771     name = lang_hooks.decl_printable_name (current_function_decl, vrb);
 772
 773   len = strlen (name) + 3; /* Two for '"'s.  One for NULL.  */
 774
 775   namep = XNEWVEC (char, len);
 776   snprintf (namep, len, "\"%s\"", name);
 777   strname.text = (unsigned char *) namep;
 778   strname.len = len - 1;
 779
 780   if (cpp_interpret_string (parse_in, &strname, 1, &cstr, false))
 781     {
 782       XDELETEVEC (namep);
 783       return (const char *) cstr.text;
 784     }
 785
 786   return namep;
 787 }
 788
 789 /* Expand DECL if it declares an entity not handled by the
 790    common code.  */
 791
 792 int
 793 c_expand_decl (tree decl)
 794 {
 795   if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl))
 796     {
 797       /* Let the back-end know about this variable.  */
 798       if (!anon_aggr_type_p (TREE_TYPE (decl)))
 799         emit_local_var (decl);
 800       else
 801         expand_anon_union_decl (decl, NULL_TREE,
 802                                 DECL_ANON_UNION_ELEMS (decl));
 803     }
 804   else
 805     return 0;
 806
 807   return 1;
 808 }
 809
 810
 811 /* Return the VAR_DECL for a const char array naming the current
 812    function. If the VAR_DECL has not yet been created, create it
 813    now. RID indicates how it should be formatted and IDENTIFIER_NODE
 814    ID is its name (unfortunately C and C++ hold the RID values of
 815    keywords in different places, so we can't derive RID from ID in
 816    this language independent code.  */
 817
 818 tree
 819 fname_decl (unsigned int rid, tree id)
 820 {
 821   unsigned ix;
 822   tree decl = NULL_TREE;
 823
 824   for (ix = 0; fname_vars[ix].decl; ix++)
 825     if (fname_vars[ix].rid == rid)
 826       break;
 827
 828   decl = *fname_vars[ix].decl;
 829   if (!decl)
 830     {
 831       /* If a tree is built here, it would normally have the lineno of
 832          the current statement.  Later this tree will be moved to the
 833          beginning of the function and this line number will be wrong.
 834          To avoid this problem set the lineno to 0 here; that prevents
 835          it from appearing in the RTL.  */
 836       tree stmts;
 837       location_t saved_location = input_location;
 838       input_location = UNKNOWN_LOCATION;
 839
 840       stmts = push_stmt_list ();
 841       decl = (*make_fname_decl) (id, fname_vars[ix].pretty);
 842       stmts = pop_stmt_list (stmts);
 843       if (!IS_EMPTY_STMT (stmts))
 844         saved_function_name_decls
 845           = tree_cons (decl, stmts, saved_function_name_decls);
 846       *fname_vars[ix].decl = decl;
 847       input_location = saved_location;
 848     }
 849   if (!ix && !current_function_decl)
 850     pedwarn ("%qD is not defined outside of function scope", decl);
 851
 852   return decl;
 853 }
 854
 855 /* Given a STRING_CST, give it a suitable array-of-chars data type.  */
 856
 857 tree
 858 fix_string_type (tree value)
 859 {
 860   const int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
 861   const int wide_flag = TREE_TYPE (value) == wchar_array_type_node;
 862   int length = TREE_STRING_LENGTH (value);
 863   int nchars;
 864   tree e_type, i_type, a_type;
 865
 866   /* Compute the number of elements, for the array type.  */
 867   nchars = wide_flag ? length / wchar_bytes : length;
 868
 869   /* C89 2.2.4.1, C99 5.2.4.1 (Translation limits).  The analogous
 870      limit in C++98 Annex B is very large (65536) and is not normative,
 871      so we do not diagnose it (warn_overlength_strings is forced off
 872      in c_common_post_options).  */
 873   if (warn_overlength_strings)
 874     {
 875       const int nchars_max = flag_isoc99 ? 4095 : 509;
 876       const int relevant_std = flag_isoc99 ? 99 : 90;
 877       if (nchars - 1 > nchars_max)
 878         /* Translators: The %d after 'ISO C' will be 90 or 99.  Do not
 879            separate the %d from the 'C'.  'ISO' should not be
 880            translated, but it may be moved after 'C%d' in languages
 881            where modifiers follow nouns.  */
 882         pedwarn ("string length %qd is greater than the length %qd "
 883                  "ISO C%d compilers are required to support",
 884                  nchars - 1, nchars_max, relevant_std);
 885     }
 886
 887   /* Create the array type for the string constant.  The ISO C++
 888      standard says that a string literal has type `const char[N]' or
 889      `const wchar_t[N]'.  We use the same logic when invoked as a C
 890      front-end with -Wwrite-strings.
 891      ??? We should change the type of an expression depending on the
 892      state of a warning flag.  We should just be warning -- see how
 893      this is handled in the C++ front-end for the deprecated implicit
 894      conversion from string literals to `char*' or `wchar_t*'.
 895
 896      The C++ front end relies on TYPE_MAIN_VARIANT of a cv-qualified
 897      array type being the unqualified version of that type.
 898      Therefore, if we are constructing an array of const char, we must
 899      construct the matching unqualified array type first.  The C front
 900      end does not require this, but it does no harm, so we do it
 901      unconditionally.  */
 902   e_type = wide_flag ? wchar_type_node : char_type_node;
 903   i_type = build_index_type (build_int_cst (NULL_TREE, nchars - 1));
 904   a_type = build_array_type (e_type, i_type);
 905   if (c_dialect_cxx() || warn_write_strings)
 906     a_type = c_build_qualified_type (a_type, TYPE_QUAL_CONST);
 907
 908   TREE_TYPE (value) = a_type;
 909   TREE_CONSTANT (value) = 1;
 910   TREE_INVARIANT (value) = 1;
 911   TREE_READONLY (value) = 1;
 912   TREE_STATIC (value) = 1;
 913   return value;
 914 }
 915 \f
 916 /* Print a warning if a constant expression had overflow in folding.
 917    Invoke this function on every expression that the language
 918    requires to be a constant expression.
 919    Note the ANSI C standard says it is erroneous for a
 920    constant expression to overflow.  */
 921
 922 void
 923 constant_expression_warning (tree value)
 924 {
 925   if (warn_overflow && pedantic
 926       && (TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
 927           || TREE_CODE (value) == FIXED_CST
 928           || TREE_CODE (value) == VECTOR_CST
 929           || TREE_CODE (value) == COMPLEX_CST)
 930       && TREE_OVERFLOW (value))
 931     pedwarn ("overflow in constant expression");
 932 }
 933
 934 /* The same as above but print an unconditional error.  */
 935 void
 936 constant_expression_error (tree value)
 937 {
 938   if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
 939        || TREE_CODE (value) == FIXED_CST
 940        || TREE_CODE (value) == VECTOR_CST
 941        || TREE_CODE (value) == COMPLEX_CST)
 942       && TREE_OVERFLOW (value))
 943     error ("overflow in constant expression");
 944 }
 945
 946 /* Print a warning if an expression had overflow in folding and its
 947    operands hadn't.
 948
 949    Invoke this function on every expression that
 950    (1) appears in the source code, and
 951    (2) is a constant expression that overflowed, and
 952    (3) is not already checked by convert_and_check;
 953    however, do not invoke this function on operands of explicit casts
 954    or when the expression is the result of an operator and any operand
 955    already overflowed.  */
 956
 957 void
 958 overflow_warning (tree value)
 959 {
 960   if (skip_evaluation) return;
 961
 962   switch (TREE_CODE (value))
 963     {
 964     case INTEGER_CST:
 965       warning (OPT_Woverflow, "integer overflow in expression");
 966       break;
 967
 968     case REAL_CST:
 969       warning (OPT_Woverflow, "floating point overflow in expression");
 970       break;
 971
 972     case FIXED_CST:
 973       warning (OPT_Woverflow, "fixed-point overflow in expression");
 974       break;
 975
 976     case VECTOR_CST:
 977       warning (OPT_Woverflow, "vector overflow in expression");
 978       break;
 979
 980     case COMPLEX_CST:
 981       if (TREE_CODE (TREE_REALPART (value)) == INTEGER_CST)
 982         warning (OPT_Woverflow, "complex integer overflow in expression");
 983       else if (TREE_CODE (TREE_REALPART (value)) == REAL_CST)
 984         warning (OPT_Woverflow, "complex floating point overflow in expression");
 985       break;
 986
 987     default:
 988       break;
 989     }
 990 }
 991
 992
 993 /* Warn about use of a logical || / && operator being used in a
 994    context where it is likely that the bitwise equivalent was intended
 995    by the programmer. CODE is the TREE_CODE of the operator, ARG1
 996    and ARG2 the arguments.  */
 997
 998 void
 999 warn_logical_operator (enum tree_code code, tree arg1, tree
1000     arg2)
1001 {
1002   switch (code)
1003     {
1004       case TRUTH_ANDIF_EXPR:
1005       case TRUTH_ORIF_EXPR:
1006       case TRUTH_OR_EXPR:
1007       case TRUTH_AND_EXPR:
1008         if (!TREE_NO_WARNING (arg1)
1009             && INTEGRAL_TYPE_P (TREE_TYPE (arg1))
1010             && !CONSTANT_CLASS_P (arg1)
1011             && TREE_CODE (arg2) == INTEGER_CST
1012             && !integer_zerop (arg2))
1013           {
1014             warning (OPT_Wlogical_op,
1015                      "logical %<%s%> with non-zero constant "
1016                      "will always evaluate as true",
1017                      ((code == TRUTH_ANDIF_EXPR)
1018                       || (code == TRUTH_AND_EXPR)) ? "&&" : "||");
1019             TREE_NO_WARNING (arg1) = true;
1020           }
1021         break;
1022       default:
1023         break;
1024     }
1025 }
1026
1027
1028 /* Print a warning about casts that might indicate violation
1029    of strict aliasing rules if -Wstrict-aliasing is used and
1030    strict aliasing mode is in effect. OTYPE is the original
1031    TREE_TYPE of EXPR, and TYPE the type we're casting to. */
1032
1033 bool
1034 strict_aliasing_warning (tree otype, tree type, tree expr)
1035 {
1036   if (!(flag_strict_aliasing && POINTER_TYPE_P (type)
1037         && POINTER_TYPE_P (otype) && !VOID_TYPE_P (TREE_TYPE (type))))
1038     return false;
1039
1040   if ((warn_strict_aliasing > 1) && TREE_CODE (expr) == ADDR_EXPR
1041       && (DECL_P (TREE_OPERAND (expr, 0))
1042           || handled_component_p (TREE_OPERAND (expr, 0))))
1043     {
1044       /* Casting the address of an object to non void pointer. Warn
1045          if the cast breaks type based aliasing.  */
1046       if (!COMPLETE_TYPE_P (TREE_TYPE (type)) && warn_strict_aliasing == 2)
1047         {
1048           warning (OPT_Wstrict_aliasing, "type-punning to incomplete type "
1049                    "might break strict-aliasing rules");
1050           return true;
1051         }
1052       else
1053         {
1054           /* warn_strict_aliasing >= 3.   This includes the default (3).
1055              Only warn if the cast is dereferenced immediately.  */
1056           alias_set_type set1 =
1057             get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0)));
1058           alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1059
1060           if (!alias_sets_conflict_p (set1, set2))
1061             {
1062               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1063                        "pointer will break strict-aliasing rules");
1064               return true;
1065             }
1066           else if (warn_strict_aliasing == 2
1067                    && !alias_sets_must_conflict_p (set1, set2))
1068             {
1069               warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1070                        "pointer might break strict-aliasing rules");
1071               return true;
1072             }
1073         }
1074     }
1075   else
1076     if ((warn_strict_aliasing == 1) && !VOID_TYPE_P (TREE_TYPE (otype)))
1077       {
1078         /* At this level, warn for any conversions, even if an address is
1079            not taken in the same statement.  This will likely produce many
1080            false positives, but could be useful to pinpoint problems that
1081            are not revealed at higher levels.  */
1082         alias_set_type set1 = get_alias_set (TREE_TYPE (otype));
1083         alias_set_type set2 = get_alias_set (TREE_TYPE (type));
1084         if (!COMPLETE_TYPE_P (type)
1085             || !alias_sets_must_conflict_p (set1, set2))
1086           {
1087             warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1088                      "pointer might break strict-aliasing rules");
1089             return true;
1090           }
1091       }
1092
1093   return false;
1094 }
1095
1096 /* Print a warning about if (); or if () .. else; constructs
1097    via the special empty statement node that we create.  INNER_THEN
1098    and INNER_ELSE are the statement lists of the if and the else
1099    block.  */
1100
1101 void
1102 empty_if_body_warning (tree inner_then, tree inner_else)
1103 {
1104   if (TREE_CODE (inner_then) == STATEMENT_LIST
1105       && STATEMENT_LIST_TAIL (inner_then))
1106     inner_then = STATEMENT_LIST_TAIL (inner_then)->stmt;
1107
1108   if (inner_else && TREE_CODE (inner_else) == STATEMENT_LIST
1109       && STATEMENT_LIST_TAIL (inner_else))
1110     inner_else = STATEMENT_LIST_TAIL (inner_else)->stmt;
1111
1112   if (IS_EMPTY_STMT (inner_then) && !inner_else)
1113     warning (OPT_Wempty_body, "%Hsuggest braces around empty body "
1114              "in an %<if%> statement", EXPR_LOCUS (inner_then));
1115
1116   else if (inner_else && IS_EMPTY_STMT (inner_else))
1117     warning (OPT_Wempty_body, "%Hsuggest braces around empty body "
1118              "in an %<else%> statement", EXPR_LOCUS (inner_else));
1119 }
1120
1121 /* Warn for unlikely, improbable, or stupid DECL declarations
1122    of `main'.  */
1123
1124 void
1125 check_main_parameter_types (tree decl)
1126 {
1127   tree args;
1128   int argct = 0;
1129
1130   for (args = TYPE_ARG_TYPES (TREE_TYPE (decl)); args;
1131       args = TREE_CHAIN (args))
1132    {
1133      tree type = args ? TREE_VALUE (args) : 0;
1134
1135      if (type == void_type_node || type == error_mark_node )
1136        break;
1137
1138      ++argct;
1139      switch (argct)
1140        {
1141        case 1:
1142          if (TYPE_MAIN_VARIANT (type) != integer_type_node)
1143            pedwarn ("first argument of %q+D should be %<int%>", decl);
1144          break;
1145
1146        case 2:
1147          if (TREE_CODE (type) != POINTER_TYPE
1148              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1149              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1150                  != char_type_node))
1151            pedwarn ("second argument of %q+D should be %<char **%>",
1152                     decl);
1153          break;
1154
1155        case 3:
1156          if (TREE_CODE (type) != POINTER_TYPE
1157              || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
1158              || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
1159                  != char_type_node))
1160            pedwarn ("third argument of %q+D should probably be "
1161                     "%<char **%>", decl);
1162          break;
1163        }
1164    }
1165
1166   /* It is intentional that this message does not mention the third
1167     argument because it's only mentioned in an appendix of the
1168     standard.  */
1169   if (argct > 0 && (argct < 2 || argct > 3))
1170    pedwarn ("%q+D takes only zero or two arguments", decl);
1171 }
1172
1173 /* True if vector types T1 and T2 can be converted to each other
1174    without an explicit cast.  If EMIT_LAX_NOTE is true, and T1 and T2
1175    can only be converted with -flax-vector-conversions yet that is not
1176    in effect, emit a note telling the user about that option if such
1177    a note has not previously been emitted.  */
1178 bool
1179 vector_types_convertible_p (const_tree t1, const_tree t2, bool emit_lax_note)
1180 {
1181   static bool emitted_lax_note = false;
1182   bool convertible_lax;
1183
1184   if ((targetm.vector_opaque_p (t1) || targetm.vector_opaque_p (t2))
1185       && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)))
1186     return true;
1187
1188   convertible_lax =
1189     (tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2))
1190      && (TREE_CODE (TREE_TYPE (t1)) != REAL_TYPE ||
1191          TYPE_PRECISION (t1) == TYPE_PRECISION (t2))
1192      && (INTEGRAL_TYPE_P (TREE_TYPE (t1))
1193          == INTEGRAL_TYPE_P (TREE_TYPE (t2))));
1194
1195   if (!convertible_lax || flag_lax_vector_conversions)
1196     return convertible_lax;
1197
1198   if (TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1199       && lang_hooks.types_compatible_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1200     return true;
1201
1202   if (emit_lax_note && !emitted_lax_note)
1203     {
1204       emitted_lax_note = true;
1205       inform ("use -flax-vector-conversions to permit "
1206               "conversions between vectors with differing "
1207               "element types or numbers of subparts");
1208     }
1209
1210   return false;
1211 }
1212
1213 /* Warns if the conversion of EXPR to TYPE may alter a value.
1214    This is a helper function for warnings_for_convert_and_check.  */
1215
1216 static void
1217 conversion_warning (tree type, tree expr)
1218 {
1219   bool give_warning = false;
1220
1221   unsigned int formal_prec = TYPE_PRECISION (type);
1222
1223   if (!warn_conversion && !warn_sign_conversion)
1224     return;
1225
1226   if (TREE_CODE (expr) == REAL_CST || TREE_CODE (expr) == INTEGER_CST)
1227     {
1228       /* Warn for real constant that is not an exact integer converted
1229          to integer type.  */
1230       if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
1231           && TREE_CODE (type) == INTEGER_TYPE)
1232         {
1233           if (!real_isinteger (TREE_REAL_CST_PTR (expr), TYPE_MODE (TREE_TYPE (expr))))
1234             give_warning = true;
1235         }
1236       /* Warn for an integer constant that does not fit into integer type.  */
1237       else if (TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
1238                && TREE_CODE (type) == INTEGER_TYPE
1239                && !int_fits_type_p (expr, type))
1240         {
1241           if (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (TREE_TYPE (expr)))
1242             warning (OPT_Wsign_conversion,
1243                      "negative integer implicitly converted to unsigned type");
1244           else if (!TYPE_UNSIGNED (type) && TYPE_UNSIGNED (TREE_TYPE (expr)))
1245             warning (OPT_Wsign_conversion,
1246                      "conversion of unsigned constant value to negative integer");
1247           else
1248             give_warning = true;
1249         }
1250       else if (TREE_CODE (type) == REAL_TYPE)
1251         {
1252           /* Warn for an integer constant that does not fit into real type.  */
1253           if (TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE)
1254             {
1255               REAL_VALUE_TYPE a = real_value_from_int_cst (0, expr);
1256               if (!exact_real_truncate (TYPE_MODE (type), &a))
1257                 give_warning = true;
1258             }
1259           /* Warn for a real constant that does not fit into a smaller
1260              real type.  */
1261           else if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
1262                    && formal_prec < TYPE_PRECISION (TREE_TYPE (expr)))
1263             {
1264               REAL_VALUE_TYPE a = TREE_REAL_CST (expr);
1265               if (!exact_real_truncate (TYPE_MODE (type), &a))
1266                 give_warning = true;
1267             }
1268         }
1269
1270       if (give_warning)
1271         warning (OPT_Wconversion,
1272                  "conversion to %qT alters %qT constant value",
1273                  type, TREE_TYPE (expr));
1274     }
1275   else /* 'expr' is not a constant.  */
1276     {
1277       /* Warn for real types converted to integer types.  */
1278       if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
1279           && TREE_CODE (type) == INTEGER_TYPE)
1280         give_warning = true;
1281
1282       else if (TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
1283                && TREE_CODE (type) == INTEGER_TYPE)
1284         {
1285           /* Don't warn about unsigned char y = 0xff, x = (int) y;  */
1286           expr = get_unwidened (expr, 0);
1287
1288           /* Warn for integer types converted to smaller integer types.  */
1289           if (formal_prec < TYPE_PRECISION (TREE_TYPE (expr)))
1290             give_warning = true;
1291
1292           /* When they are the same width but different signedness,
1293              then the value may change.  */
1294           else if ((formal_prec == TYPE_PRECISION (TREE_TYPE (expr))
1295                     && TYPE_UNSIGNED (TREE_TYPE (expr)) != TYPE_UNSIGNED (type))
1296                    /* Even when converted to a bigger type, if the type is
1297                       unsigned but expr is signed, then negative values
1298                       will be changed.  */
1299                    || (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (TREE_TYPE (expr))))
1300             warning (OPT_Wsign_conversion,
1301                      "conversion to %qT from %qT may change the sign of the result",
1302                      type, TREE_TYPE (expr));
1303         }
1304
1305       /* Warn for integer types converted to real types if and only if
1306          all the range of values of the integer type cannot be
1307          represented by the real type.  */
1308       else if (TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
1309                && TREE_CODE (type) == REAL_TYPE)
1310         {
1311           tree type_low_bound = TYPE_MIN_VALUE (TREE_TYPE (expr));
1312           tree type_high_bound = TYPE_MAX_VALUE (TREE_TYPE (expr));
1313           REAL_VALUE_TYPE real_low_bound = real_value_from_int_cst (0, type_low_bound);
1314           REAL_VALUE_TYPE real_high_bound = real_value_from_int_cst (0, type_high_bound);
1315
1316           if (!exact_real_truncate (TYPE_MODE (type), &real_low_bound)
1317               || !exact_real_truncate (TYPE_MODE (type), &real_high_bound))
1318             give_warning = true;
1319         }
1320
1321       /* Warn for real types converted to smaller real types.  */
1322       else if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
1323                && TREE_CODE (type) == REAL_TYPE
1324                && formal_prec < TYPE_PRECISION (TREE_TYPE (expr)))
1325         give_warning = true;
1326
1327
1328       if (give_warning)
1329         warning (OPT_Wconversion,
1330                  "conversion to %qT from %qT may alter its value",
1331                  type, TREE_TYPE (expr));
1332     }
1333 }
1334
1335 /* Produce warnings after a conversion. RESULT is the result of
1336    converting EXPR to TYPE.  This is a helper function for
1337    convert_and_check and cp_convert_and_check.  */
1338
1339 void
1340 warnings_for_convert_and_check (tree type, tree expr, tree result)
1341 {
1342   if (TREE_CODE (expr) == INTEGER_CST
1343       && (TREE_CODE (type) == INTEGER_TYPE
1344           || TREE_CODE (type) == ENUMERAL_TYPE)
1345       && !int_fits_type_p (expr, type))
1346     {
1347       /* Do not diagnose overflow in a constant expression merely
1348          because a conversion overflowed.  */
1349       if (TREE_OVERFLOW (result))
1350         TREE_OVERFLOW (result) = TREE_OVERFLOW (expr);
1351
1352       if (TYPE_UNSIGNED (type))
1353         {
1354           /* This detects cases like converting -129 or 256 to
1355              unsigned char.  */
1356           if (!int_fits_type_p (expr, c_common_signed_type (type)))
1357             warning (OPT_Woverflow,
1358                      "large integer implicitly truncated to unsigned type");
1359           else
1360             conversion_warning (type, expr);
1361         }
1362       else if (!int_fits_type_p (expr, c_common_unsigned_type (type)))
1363         warning (OPT_Woverflow,
1364                  "overflow in implicit constant conversion");
1365       /* No warning for converting 0x80000000 to int.  */
1366       else if (pedantic
1367                && (TREE_CODE (TREE_TYPE (expr)) != INTEGER_TYPE
1368                    || TYPE_PRECISION (TREE_TYPE (expr))
1369                    != TYPE_PRECISION (type)))
1370         warning (OPT_Woverflow,
1371                  "overflow in implicit constant conversion");
1372
1373       else
1374         conversion_warning (type, expr);
1375     }
1376   else if ((TREE_CODE (result) == INTEGER_CST
1377             || TREE_CODE (result) == FIXED_CST) && TREE_OVERFLOW (result))
1378     warning (OPT_Woverflow,
1379              "overflow in implicit constant conversion");
1380   else
1381     conversion_warning (type, expr);
1382 }
1383
1384
1385 /* Convert EXPR to TYPE, warning about conversion problems with constants.
1386    Invoke this function on every expression that is converted implicitly,
1387    i.e. because of language rules and not because of an explicit cast.  */
1388
1389 tree
1390 convert_and_check (tree type, tree expr)
1391 {
1392   tree result;
1393
1394   if (TREE_TYPE (expr) == type)
1395     return expr;
1396
1397   result = convert (type, expr);
1398
1399   if (!skip_evaluation && !TREE_OVERFLOW_P (expr) && result != error_mark_node)
1400     warnings_for_convert_and_check (type, expr, result);
1401
1402   return result;
1403 }
1404 \f
1405 /* A node in a list that describes references to variables (EXPR), which are
1406    either read accesses if WRITER is zero, or write accesses, in which case
1407    WRITER is the parent of EXPR.  */
1408 struct tlist
1409 {
1410   struct tlist *next;
1411   tree expr, writer;
1412 };
1413
1414 /* Used to implement a cache the results of a call to verify_tree.  We only
1415    use this for SAVE_EXPRs.  */
1416 struct tlist_cache
1417 {
1418   struct tlist_cache *next;
1419   struct tlist *cache_before_sp;
1420   struct tlist *cache_after_sp;
1421   tree expr;
1422 };
1423
1424 /* Obstack to use when allocating tlist structures, and corresponding
1425    firstobj.  */
1426 static struct obstack tlist_obstack;
1427 static char *tlist_firstobj = 0;
1428
1429 /* Keep track of the identifiers we've warned about, so we can avoid duplicate
1430    warnings.  */
1431 static struct tlist *warned_ids;
1432 /* SAVE_EXPRs need special treatment.  We process them only once and then
1433    cache the results.  */
1434 static struct tlist_cache *save_expr_cache;
1435
1436 static void add_tlist (struct tlist **, struct tlist *, tree, int);
1437 static void merge_tlist (struct tlist **, struct tlist *, int);
1438 static void verify_tree (tree, struct tlist **, struct tlist **, tree);
1439 static int warning_candidate_p (tree);
1440 static void warn_for_collisions (struct tlist *);
1441 static void warn_for_collisions_1 (tree, tree, struct tlist *, int);
1442 static struct tlist *new_tlist (struct tlist *, tree, tree);
1443
1444 /* Create a new struct tlist and fill in its fields.  */
1445 static struct tlist *
1446 new_tlist (struct tlist *next, tree t, tree writer)
1447 {
1448   struct tlist *l;
1449   l = XOBNEW (&tlist_obstack, struct tlist);
1450   l->next = next;
1451   l->expr = t;
1452   l->writer = writer;
1453   return l;
1454 }
1455
1456 /* Add duplicates of the nodes found in ADD to the list *TO.  If EXCLUDE_WRITER
1457    is nonnull, we ignore any node we find which has a writer equal to it.  */
1458
1459 static void
1460 add_tlist (struct tlist **to, struct tlist *add, tree exclude_writer, int copy)
1461 {
1462   while (add)
1463     {
1464       struct tlist *next = add->next;
1465       if (!copy)
1466         add->next = *to;
1467       if (!exclude_writer || add->writer != exclude_writer)
1468         *to = copy ? new_tlist (*to, add->expr, add->writer) : add;
1469       add = next;
1470     }
1471 }
1472
1473 /* Merge the nodes of ADD into TO.  This merging process is done so that for
1474    each variable that already exists in TO, no new node is added; however if
1475    there is a write access recorded in ADD, and an occurrence on TO is only
1476    a read access, then the occurrence in TO will be modified to record the
1477    write.  */
1478
1479 static void
1480 merge_tlist (struct tlist **to, struct tlist *add, int copy)
1481 {
1482   struct tlist **end = to;
1483
1484   while (*end)
1485     end = &(*end)->next;
1486
1487   while (add)
1488     {
1489       int found = 0;
1490       struct tlist *tmp2;
1491       struct tlist *next = add->next;
1492
1493       for (tmp2 = *to; tmp2; tmp2 = tmp2->next)
1494         if (tmp2->expr == add->expr)
1495           {
1496             found = 1;
1497             if (!tmp2->writer)
1498               tmp2->writer = add->writer;
1499           }
1500       if (!found)
1501         {
1502           *end = copy ? add : new_tlist (NULL, add->expr, add->writer);
1503           end = &(*end)->next;
1504           *end = 0;
1505         }
1506       add = next;
1507     }
1508 }
1509
1510 /* WRITTEN is a variable, WRITER is its parent.  Warn if any of the variable
1511    references in list LIST conflict with it, excluding reads if ONLY writers
1512    is nonzero.  */
1513
1514 static void
1515 warn_for_collisions_1 (tree written, tree writer, struct tlist *list,
1516                        int only_writes)
1517 {
1518   struct tlist *tmp;
1519
1520   /* Avoid duplicate warnings.  */
1521   for (tmp = warned_ids; tmp; tmp = tmp->next)
1522     if (tmp->expr == written)
1523       return;
1524
1525   while (list)
1526     {
1527       if (list->expr == written
1528           && list->writer != writer
1529           && (!only_writes || list->writer)
1530           && DECL_NAME (list->expr))
1531         {
1532           warned_ids = new_tlist (warned_ids, written, NULL_TREE);
1533           warning (OPT_Wsequence_point, "operation on %qE may be undefined",
1534                    list->expr);
1535         }
1536       list = list->next;
1537     }
1538 }
1539
1540 /* Given a list LIST of references to variables, find whether any of these
1541    can cause conflicts due to missing sequence points.  */
1542
1543 static void
1544 warn_for_collisions (struct tlist *list)
1545 {
1546   struct tlist *tmp;
1547
1548   for (tmp = list; tmp; tmp = tmp->next)
1549     {
1550       if (tmp->writer)
1551         warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0);
1552     }
1553 }
1554
1555 /* Return nonzero if X is a tree that can be verified by the sequence point
1556    warnings.  */
1557 static int
1558 warning_candidate_p (tree x)
1559 {
1560   return TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == PARM_DECL;
1561 }
1562
1563 /* Walk the tree X, and record accesses to variables.  If X is written by the
1564    parent tree, WRITER is the parent.
1565    We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP.  If this
1566    expression or its only operand forces a sequence point, then everything up
1567    to the sequence point is stored in PBEFORE_SP.  Everything else gets stored
1568    in PNO_SP.
1569    Once we return, we will have emitted warnings if any subexpression before
1570    such a sequence point could be undefined.  On a higher level, however, the
1571    sequence point may not be relevant, and we'll merge the two lists.
1572
1573    Example: (b++, a) + b;
1574    The call that processes the COMPOUND_EXPR will store the increment of B
1575    in PBEFORE_SP, and the use of A in PNO_SP.  The higher-level call that
1576    processes the PLUS_EXPR will need to merge the two lists so that
1577    eventually, all accesses end up on the same list (and we'll warn about the
1578    unordered subexpressions b++ and b.
1579
1580    A note on merging.  If we modify the former example so that our expression
1581    becomes
1582      (b++, b) + a
1583    care must be taken not simply to add all three expressions into the final
1584    PNO_SP list.  The function merge_tlist takes care of that by merging the
1585    before-SP list of the COMPOUND_EXPR into its after-SP list in a special
1586    way, so that no more than one access to B is recorded.  */
1587
1588 static void
1589 verify_tree (tree x, struct tlist **pbefore_sp, struct tlist **pno_sp,
1590              tree writer)
1591 {
1592   struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3;
1593   enum tree_code code;
1594   enum tree_code_class cl;
1595
1596   /* X may be NULL if it is the operand of an empty statement expression
1597      ({ }).  */
1598   if (x == NULL)
1599     return;
1600
1601  restart:
1602   code = TREE_CODE (x);
1603   cl = TREE_CODE_CLASS (code);
1604
1605   if (warning_candidate_p (x))
1606     {
1607       *pno_sp = new_tlist (*pno_sp, x, writer);
1608       return;
1609     }
1610
1611   switch (code)
1612     {
1613     case CONSTRUCTOR:
1614       return;
1615
1616     case COMPOUND_EXPR:
1617     case TRUTH_ANDIF_EXPR:
1618     case TRUTH_ORIF_EXPR:
1619       tmp_before = tmp_nosp = tmp_list3 = 0;
1620       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1621       warn_for_collisions (tmp_nosp);
1622       merge_tlist (pbefore_sp, tmp_before, 0);
1623       merge_tlist (pbefore_sp, tmp_nosp, 0);
1624       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE);
1625       merge_tlist (pbefore_sp, tmp_list3, 0);
1626       return;
1627
1628     case COND_EXPR:
1629       tmp_before = tmp_list2 = 0;
1630       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE);
1631       warn_for_collisions (tmp_list2);
1632       merge_tlist (pbefore_sp, tmp_before, 0);
1633       merge_tlist (pbefore_sp, tmp_list2, 1);
1634
1635       tmp_list3 = tmp_nosp = 0;
1636       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE);
1637       warn_for_collisions (tmp_nosp);
1638       merge_tlist (pbefore_sp, tmp_list3, 0);
1639
1640       tmp_list3 = tmp_list2 = 0;
1641       verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE);
1642       warn_for_collisions (tmp_list2);
1643       merge_tlist (pbefore_sp, tmp_list3, 0);
1644       /* Rather than add both tmp_nosp and tmp_list2, we have to merge the
1645          two first, to avoid warning for (a ? b++ : b++).  */
1646       merge_tlist (&tmp_nosp, tmp_list2, 0);
1647       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1648       return;
1649
1650     case PREDECREMENT_EXPR:
1651     case PREINCREMENT_EXPR:
1652     case POSTDECREMENT_EXPR:
1653     case POSTINCREMENT_EXPR:
1654       verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x);
1655       return;
1656
1657     case MODIFY_EXPR:
1658       tmp_before = tmp_nosp = tmp_list3 = 0;
1659       verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE);
1660       verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x);
1661       /* Expressions inside the LHS are not ordered wrt. the sequence points
1662          in the RHS.  Example:
1663            *a = (a++, 2)
1664          Despite the fact that the modification of "a" is in the before_sp
1665          list (tmp_before), it conflicts with the use of "a" in the LHS.
1666          We can handle this by adding the contents of tmp_list3
1667          to those of tmp_before, and redoing the collision warnings for that
1668          list.  */
1669       add_tlist (&tmp_before, tmp_list3, x, 1);
1670       warn_for_collisions (tmp_before);
1671       /* Exclude the LHS itself here; we first have to merge it into the
1672          tmp_nosp list.  This is done to avoid warning for "a = a"; if we
1673          didn't exclude the LHS, we'd get it twice, once as a read and once
1674          as a write.  */
1675       add_tlist (pno_sp, tmp_list3, x, 0);
1676       warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1);
1677
1678       merge_tlist (pbefore_sp, tmp_before, 0);
1679       if (warning_candidate_p (TREE_OPERAND (x, 0)))
1680         merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0);
1681       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1);
1682       return;
1683
1684     case CALL_EXPR:
1685       /* We need to warn about conflicts among arguments and conflicts between
1686          args and the function address.  Side effects of the function address,
1687          however, are not ordered by the sequence point of the call.  */
1688       {
1689         call_expr_arg_iterator iter;
1690         tree arg;
1691         tmp_before = tmp_nosp = 0;
1692         verify_tree (CALL_EXPR_FN (x), &tmp_before, &tmp_nosp, NULL_TREE);
1693         FOR_EACH_CALL_EXPR_ARG (arg, iter, x)
1694           {
1695             tmp_list2 = tmp_list3 = 0;
1696             verify_tree (arg, &tmp_list2, &tmp_list3, NULL_TREE);
1697             merge_tlist (&tmp_list3, tmp_list2, 0);
1698             add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0);
1699           }
1700         add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0);
1701         warn_for_collisions (tmp_before);
1702         add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0);
1703         return;
1704       }
1705
1706     case TREE_LIST:
1707       /* Scan all the list, e.g. indices of multi dimensional array.  */
1708       while (x)
1709         {
1710           tmp_before = tmp_nosp = 0;
1711           verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE);
1712           merge_tlist (&tmp_nosp, tmp_before, 0);
1713           add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1714           x = TREE_CHAIN (x);
1715         }
1716       return;
1717
1718     case SAVE_EXPR:
1719       {
1720         struct tlist_cache *t;
1721         for (t = save_expr_cache; t; t = t->next)
1722           if (t->expr == x)
1723             break;
1724
1725         if (!t)
1726           {
1727             t = XOBNEW (&tlist_obstack, struct tlist_cache);
1728             t->next = save_expr_cache;
1729             t->expr = x;
1730             save_expr_cache = t;
1731
1732             tmp_before = tmp_nosp = 0;
1733             verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1734             warn_for_collisions (tmp_nosp);
1735
1736             tmp_list3 = 0;
1737             while (tmp_nosp)
1738               {
1739                 struct tlist *t = tmp_nosp;
1740                 tmp_nosp = t->next;
1741                 merge_tlist (&tmp_list3, t, 0);
1742               }
1743             t->cache_before_sp = tmp_before;
1744             t->cache_after_sp = tmp_list3;
1745           }
1746         merge_tlist (pbefore_sp, t->cache_before_sp, 1);
1747         add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1);
1748         return;
1749       }
1750
1751     default:
1752       /* For other expressions, simply recurse on their operands.
1753          Manual tail recursion for unary expressions.
1754          Other non-expressions need not be processed.  */
1755       if (cl == tcc_unary)
1756         {
1757           x = TREE_OPERAND (x, 0);
1758           writer = 0;
1759           goto restart;
1760         }
1761       else if (IS_EXPR_CODE_CLASS (cl))
1762         {
1763           int lp;
1764           int max = TREE_OPERAND_LENGTH (x);
1765           for (lp = 0; lp < max; lp++)
1766             {
1767               tmp_before = tmp_nosp = 0;
1768               verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, 0);
1769               merge_tlist (&tmp_nosp, tmp_before, 0);
1770               add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1771             }
1772         }
1773       return;
1774     }
1775 }
1776
1777 /* Try to warn for undefined behavior in EXPR due to missing sequence
1778    points.  */
1779
1780 void
1781 verify_sequence_points (tree expr)
1782 {
1783   struct tlist *before_sp = 0, *after_sp = 0;
1784
1785   warned_ids = 0;
1786   save_expr_cache = 0;
1787   if (tlist_firstobj == 0)
1788     {
1789       gcc_obstack_init (&tlist_obstack);
1790       tlist_firstobj = (char *) obstack_alloc (&tlist_obstack, 0);
1791     }
1792
1793   verify_tree (expr, &before_sp, &after_sp, 0);
1794   warn_for_collisions (after_sp);
1795   obstack_free (&tlist_obstack, tlist_firstobj);
1796 }
1797 \f
1798 /* Validate the expression after `case' and apply default promotions.  */
1799
1800 static tree
1801 check_case_value (tree value)
1802 {
1803   if (value == NULL_TREE)
1804     return value;
1805
1806   /* ??? Can we ever get nops here for a valid case value?  We
1807      shouldn't for C.  */
1808   STRIP_TYPE_NOPS (value);
1809   /* In C++, the following is allowed:
1810
1811        const int i = 3;
1812        switch (...) { case i: ... }
1813
1814      So, we try to reduce the VALUE to a constant that way.  */
1815   if (c_dialect_cxx ())
1816     {
1817       value = decl_constant_value (value);
1818       STRIP_TYPE_NOPS (value);
1819       value = fold (value);
1820     }
1821
1822   if (TREE_CODE (value) == INTEGER_CST)
1823     /* Promote char or short to int.  */
1824     value = perform_integral_promotions (value);
1825   else if (value != error_mark_node)
1826     {
1827       error ("case label does not reduce to an integer constant");
1828       value = error_mark_node;
1829     }
1830
1831   constant_expression_warning (value);
1832
1833   return value;
1834 }
1835 \f
1836 /* See if the case values LOW and HIGH are in the range of the original
1837    type (i.e. before the default conversion to int) of the switch testing
1838    expression.
1839    TYPE is the promoted type of the testing expression, and ORIG_TYPE is
1840    the type before promoting it.  CASE_LOW_P is a pointer to the lower
1841    bound of the case label, and CASE_HIGH_P is the upper bound or NULL
1842    if the case is not a case range.
1843    The caller has to make sure that we are not called with NULL for
1844    CASE_LOW_P (i.e. the default case).
1845    Returns true if the case label is in range of ORIG_TYPE (saturated or
1846    untouched) or false if the label is out of range.  */
1847
1848 static bool
1849 check_case_bounds (tree type, tree orig_type,
1850                    tree *case_low_p, tree *case_high_p)
1851 {
1852   tree min_value, max_value;
1853   tree case_low = *case_low_p;
1854   tree case_high = case_high_p ? *case_high_p : case_low;
1855
1856   /* If there was a problem with the original type, do nothing.  */
1857   if (orig_type == error_mark_node)
1858     return true;
1859
1860   min_value = TYPE_MIN_VALUE (orig_type);
1861   max_value = TYPE_MAX_VALUE (orig_type);
1862
1863   /* Case label is less than minimum for type.  */
1864   if (tree_int_cst_compare (case_low, min_value) < 0
1865       && tree_int_cst_compare (case_high, min_value) < 0)
1866     {
1867       warning (0, "case label value is less than minimum value for type");
1868       return false;
1869     }
1870
1871   /* Case value is greater than maximum for type.  */
1872   if (tree_int_cst_compare (case_low, max_value) > 0
1873       && tree_int_cst_compare (case_high, max_value) > 0)
1874     {
1875       warning (0, "case label value exceeds maximum value for type");
1876       return false;
1877     }
1878
1879   /* Saturate lower case label value to minimum.  */
1880   if (tree_int_cst_compare (case_high, min_value) >= 0
1881       && tree_int_cst_compare (case_low, min_value) < 0)
1882     {
1883       warning (0, "lower value in case label range"
1884                " less than minimum value for type");
1885       case_low = min_value;
1886     }
1887
1888   /* Saturate upper case label value to maximum.  */
1889   if (tree_int_cst_compare (case_low, max_value) <= 0
1890       && tree_int_cst_compare (case_high, max_value) > 0)
1891     {
1892       warning (0, "upper value in case label range"
1893                " exceeds maximum value for type");
1894       case_high = max_value;
1895     }
1896
1897   if (*case_low_p != case_low)
1898     *case_low_p = convert (type, case_low);
1899   if (case_high_p && *case_high_p != case_high)
1900     *case_high_p = convert (type, case_high);
1901
1902   return true;
1903 }
1904 \f
1905 /* Return an integer type with BITS bits of precision,
1906    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
1907
1908 tree
1909 c_common_type_for_size (unsigned int bits, int unsignedp)
1910 {
1911   if (bits == TYPE_PRECISION (integer_type_node))
1912     return unsignedp ? unsigned_type_node : integer_type_node;
1913
1914   if (bits == TYPE_PRECISION (signed_char_type_node))
1915     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1916
1917   if (bits == TYPE_PRECISION (short_integer_type_node))
1918     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1919
1920   if (bits == TYPE_PRECISION (long_integer_type_node))
1921     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1922
1923   if (bits == TYPE_PRECISION (long_long_integer_type_node))
1924     return (unsignedp ? long_long_unsigned_type_node
1925             : long_long_integer_type_node);
1926
1927   if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
1928     return (unsignedp ? widest_unsigned_literal_type_node
1929             : widest_integer_literal_type_node);
1930
1931   if (bits <= TYPE_PRECISION (intQI_type_node))
1932     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1933
1934   if (bits <= TYPE_PRECISION (intHI_type_node))
1935     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1936
1937   if (bits <= TYPE_PRECISION (intSI_type_node))
1938     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1939
1940   if (bits <= TYPE_PRECISION (intDI_type_node))
1941     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1942
1943   return 0;
1944 }
1945
1946 /* Return a fixed-point type that has at least IBIT ibits and FBIT fbits
1947    that is unsigned if UNSIGNEDP is nonzero, otherwise signed;
1948    and saturating if SATP is nonzero, otherwise not saturating.  */
1949
1950 tree
1951 c_common_fixed_point_type_for_size (unsigned int ibit, unsigned int fbit,
1952                                     int unsignedp, int satp)
1953 {
1954   enum machine_mode mode;
1955   if (ibit == 0)
1956     mode = unsignedp ? UQQmode : QQmode;
1957   else
1958     mode = unsignedp ? UHAmode : HAmode;
1959
1960   for (; mode != VOIDmode; mode = GET_MODE_WIDER_MODE (mode))
1961     if (GET_MODE_IBIT (mode) >= ibit && GET_MODE_FBIT (mode) >= fbit)
1962       break;
1963
1964   if (mode == VOIDmode || !targetm.scalar_mode_supported_p (mode))
1965     {
1966       sorry ("GCC cannot support operators with integer types and "
1967              "fixed-point types that have too many integral and "
1968              "fractional bits together");
1969       return 0;
1970     }
1971
1972   return c_common_type_for_mode (mode, satp);
1973 }
1974
1975 /* Used for communication between c_common_type_for_mode and
1976    c_register_builtin_type.  */
1977 static GTY(()) tree registered_builtin_types;
1978
1979 /* Return a data type that has machine mode MODE.
1980    If the mode is an integer,
1981    then UNSIGNEDP selects between signed and unsigned types.
1982    If the mode is a fixed-point mode,
1983    then UNSIGNEDP selects between saturating and nonsaturating types.  */
1984
1985 tree
1986 c_common_type_for_mode (enum machine_mode mode, int unsignedp)
1987 {
1988   tree t;
1989
1990   if (mode == TYPE_MODE (integer_type_node))
1991     return unsignedp ? unsigned_type_node : integer_type_node;
1992
1993   if (mode == TYPE_MODE (signed_char_type_node))
1994     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1995
1996   if (mode == TYPE_MODE (short_integer_type_node))
1997     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1998
1999   if (mode == TYPE_MODE (long_integer_type_node))
2000     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2001
2002   if (mode == TYPE_MODE (long_long_integer_type_node))
2003     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
2004
2005   if (mode == TYPE_MODE (widest_integer_literal_type_node))
2006     return unsignedp ? widest_unsigned_literal_type_node
2007                      : widest_integer_literal_type_node;
2008
2009   if (mode == QImode)
2010     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2011
2012   if (mode == HImode)
2013     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2014
2015   if (mode == SImode)
2016     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2017
2018   if (mode == DImode)
2019     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2020
2021 #if HOST_BITS_PER_WIDE_INT >= 64
2022   if (mode == TYPE_MODE (intTI_type_node))
2023     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
2024 #endif
2025
2026   if (mode == TYPE_MODE (float_type_node))
2027     return float_type_node;
2028
2029   if (mode == TYPE_MODE (double_type_node))
2030     return double_type_node;
2031
2032   if (mode == TYPE_MODE (long_double_type_node))
2033     return long_double_type_node;
2034
2035   if (mode == TYPE_MODE (void_type_node))
2036     return void_type_node;
2037
2038   if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
2039     return (unsignedp
2040             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2041             : make_signed_type (GET_MODE_PRECISION (mode)));
2042
2043   if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
2044     return (unsignedp
2045             ? make_unsigned_type (GET_MODE_PRECISION (mode))
2046             : make_signed_type (GET_MODE_PRECISION (mode)));
2047
2048   if (COMPLEX_MODE_P (mode))
2049     {
2050       enum machine_mode inner_mode;
2051       tree inner_type;
2052
2053       if (mode == TYPE_MODE (complex_float_type_node))
2054         return complex_float_type_node;
2055       if (mode == TYPE_MODE (complex_double_type_node))
2056         return complex_double_type_node;
2057       if (mode == TYPE_MODE (complex_long_double_type_node))
2058         return complex_long_double_type_node;
2059
2060       if (mode == TYPE_MODE (complex_integer_type_node) && !unsignedp)
2061         return complex_integer_type_node;
2062
2063       inner_mode = GET_MODE_INNER (mode);
2064       inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2065       if (inner_type != NULL_TREE)
2066         return build_complex_type (inner_type);
2067     }
2068   else if (VECTOR_MODE_P (mode))
2069     {
2070       enum machine_mode inner_mode = GET_MODE_INNER (mode);
2071       tree inner_type = c_common_type_for_mode (inner_mode, unsignedp);
2072       if (inner_type != NULL_TREE)
2073         return build_vector_type_for_mode (inner_type, mode);
2074     }
2075
2076   if (mode == TYPE_MODE (dfloat32_type_node))
2077     return dfloat32_type_node;
2078   if (mode == TYPE_MODE (dfloat64_type_node))
2079     return dfloat64_type_node;
2080   if (mode == TYPE_MODE (dfloat128_type_node))
2081     return dfloat128_type_node;
2082
2083   if (ALL_SCALAR_FIXED_POINT_MODE_P (mode))
2084     {
2085       if (mode == TYPE_MODE (short_fract_type_node))
2086         return unsignedp ? sat_short_fract_type_node : short_fract_type_node;
2087       if (mode == TYPE_MODE (fract_type_node))
2088         return unsignedp ? sat_fract_type_node : fract_type_node;
2089       if (mode == TYPE_MODE (long_fract_type_node))
2090         return unsignedp ? sat_long_fract_type_node : long_fract_type_node;
2091       if (mode == TYPE_MODE (long_long_fract_type_node))
2092         return unsignedp ? sat_long_long_fract_type_node
2093                          : long_long_fract_type_node;
2094
2095       if (mode == TYPE_MODE (unsigned_short_fract_type_node))
2096         return unsignedp ? sat_unsigned_short_fract_type_node
2097                          : unsigned_short_fract_type_node;
2098       if (mode == TYPE_MODE (unsigned_fract_type_node))
2099         return unsignedp ? sat_unsigned_fract_type_node
2100                          : unsigned_fract_type_node;
2101       if (mode == TYPE_MODE (unsigned_long_fract_type_node))
2102         return unsignedp ? sat_unsigned_long_fract_type_node
2103                          : unsigned_long_fract_type_node;
2104       if (mode == TYPE_MODE (unsigned_long_long_fract_type_node))
2105         return unsignedp ? sat_unsigned_long_long_fract_type_node
2106                          : unsigned_long_long_fract_type_node;
2107
2108       if (mode == TYPE_MODE (short_accum_type_node))
2109         return unsignedp ? sat_short_accum_type_node : short_accum_type_node;
2110       if (mode == TYPE_MODE (accum_type_node))
2111         return unsignedp ? sat_accum_type_node : accum_type_node;
2112       if (mode == TYPE_MODE (long_accum_type_node))
2113         return unsignedp ? sat_long_accum_type_node : long_accum_type_node;
2114       if (mode == TYPE_MODE (long_long_accum_type_node))
2115         return unsignedp ? sat_long_long_accum_type_node
2116                          : long_long_accum_type_node;
2117
2118       if (mode == TYPE_MODE (unsigned_short_accum_type_node))
2119         return unsignedp ? sat_unsigned_short_accum_type_node
2120                          : unsigned_short_accum_type_node;
2121       if (mode == TYPE_MODE (unsigned_accum_type_node))
2122         return unsignedp ? sat_unsigned_accum_type_node
2123                          : unsigned_accum_type_node;
2124       if (mode == TYPE_MODE (unsigned_long_accum_type_node))
2125         return unsignedp ? sat_unsigned_long_accum_type_node
2126                          : unsigned_long_accum_type_node;
2127       if (mode == TYPE_MODE (unsigned_long_long_accum_type_node))
2128         return unsignedp ? sat_unsigned_long_long_accum_type_node
2129                          : unsigned_long_long_accum_type_node;
2130
2131       if (mode == QQmode)
2132         return unsignedp ? sat_qq_type_node : qq_type_node;
2133       if (mode == HQmode)
2134         return unsignedp ? sat_hq_type_node : hq_type_node;
2135       if (mode == SQmode)
2136         return unsignedp ? sat_sq_type_node : sq_type_node;
2137       if (mode == DQmode)
2138         return unsignedp ? sat_dq_type_node : dq_type_node;
2139       if (mode == TQmode)
2140         return unsignedp ? sat_tq_type_node : tq_type_node;
2141
2142       if (mode == UQQmode)
2143         return unsignedp ? sat_uqq_type_node : uqq_type_node;
2144       if (mode == UHQmode)
2145         return unsignedp ? sat_uhq_type_node : uhq_type_node;
2146       if (mode == USQmode)
2147         return unsignedp ? sat_usq_type_node : usq_type_node;
2148       if (mode == UDQmode)
2149         return unsignedp ? sat_udq_type_node : udq_type_node;
2150       if (mode == UTQmode)
2151         return unsignedp ? sat_utq_type_node : utq_type_node;
2152
2153       if (mode == HAmode)
2154         return unsignedp ? sat_ha_type_node : ha_type_node;
2155       if (mode == SAmode)
2156         return unsignedp ? sat_sa_type_node : sa_type_node;
2157       if (mode == DAmode)
2158         return unsignedp ? sat_da_type_node : da_type_node;
2159       if (mode == TAmode)
2160         return unsignedp ? sat_ta_type_node : ta_type_node;
2161
2162       if (mode == UHAmode)
2163         return unsignedp ? sat_uha_type_node : uha_type_node;
2164       if (mode == USAmode)
2165         return unsignedp ? sat_usa_type_node : usa_type_node;
2166       if (mode == UDAmode)
2167         return unsignedp ? sat_uda_type_node : uda_type_node;
2168       if (mode == UTAmode)
2169         return unsignedp ? sat_uta_type_node : uta_type_node;
2170     }
2171
2172   for (t = registered_builtin_types; t; t = TREE_CHAIN (t))
2173     if (TYPE_MODE (TREE_VALUE (t)) == mode)
2174       return TREE_VALUE (t);
2175
2176   return 0;
2177 }
2178
2179 tree
2180 c_common_unsigned_type (tree type)
2181 {
2182   return c_common_signed_or_unsigned_type (1, type);
2183 }
2184
2185 /* Return a signed type the same as TYPE in other respects.  */
2186
2187 tree
2188 c_common_signed_type (tree type)
2189 {
2190   return c_common_signed_or_unsigned_type (0, type);
2191 }
2192
2193 /* Return a type the same as TYPE except unsigned or
2194    signed according to UNSIGNEDP.  */
2195
2196 tree
2197 c_common_signed_or_unsigned_type (int unsignedp, tree type)
2198 {
2199   tree type1;
2200
2201   /* This block of code emulates the behavior of the old
2202      c_common_unsigned_type. In particular, it returns
2203      long_unsigned_type_node if passed a long, even when a int would
2204      have the same size. This is necessary for warnings to work
2205      correctly in archs where sizeof(int) == sizeof(long) */
2206
2207   type1 = TYPE_MAIN_VARIANT (type);
2208   if (type1 == signed_char_type_node || type1 == char_type_node || type1 == unsigned_char_type_node)
2209     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2210   if (type1 == integer_type_node || type1 == unsigned_type_node)
2211     return unsignedp ? unsigned_type_node : integer_type_node;
2212   if (type1 == short_integer_type_node || type1 == short_unsigned_type_node)
2213     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2214   if (type1 == long_integer_type_node || type1 == long_unsigned_type_node)
2215     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2216   if (type1 == long_long_integer_type_node || type1 == long_long_unsigned_type_node)
2217     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
2218   if (type1 == widest_integer_literal_type_node || type1 == widest_unsigned_literal_type_node)
2219     return unsignedp ? widest_unsigned_literal_type_node : widest_integer_literal_type_node;
2220 #if HOST_BITS_PER_WIDE_INT >= 64
2221   if (type1 == intTI_type_node || type1 == unsigned_intTI_type_node)
2222     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
2223 #endif
2224   if (type1 == intDI_type_node || type1 == unsigned_intDI_type_node)
2225     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2226   if (type1 == intSI_type_node || type1 == unsigned_intSI_type_node)
2227     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2228   if (type1 == intHI_type_node || type1 == unsigned_intHI_type_node)
2229     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2230   if (type1 == intQI_type_node || type1 == unsigned_intQI_type_node)
2231     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2232
2233 #define C_COMMON_FIXED_TYPES(SAT,NAME) \
2234   if (type1 == SAT ## short_ ## NAME ## _type_node \
2235       || type1 == SAT ## unsigned_short_ ## NAME ## _type_node) \
2236     return unsignedp ? SAT ## unsigned_short_ ## NAME ## _type_node \
2237                      : SAT ## short_ ## NAME ## _type_node; \
2238   if (type1 == SAT ## NAME ## _type_node \
2239       || type1 == SAT ## unsigned_ ## NAME ## _type_node) \
2240     return unsignedp ? SAT ## unsigned_ ## NAME ## _type_node \
2241                      : SAT ## NAME ## _type_node; \
2242   if (type1 == SAT ## long_ ## NAME ## _type_node \
2243       || type1 == SAT ## unsigned_long_ ## NAME ## _type_node) \
2244     return unsignedp ? SAT ## unsigned_long_ ## NAME ## _type_node \
2245                      : SAT ## long_ ## NAME ## _type_node; \
2246   if (type1 == SAT ## long_long_ ## NAME ## _type_node \
2247       || type1 == SAT ## unsigned_long_long_ ## NAME ## _type_node) \
2248     return unsignedp ? SAT ## unsigned_long_long_ ## NAME ## _type_node \
2249                      : SAT ## long_long_ ## NAME ## _type_node;
2250
2251 #define C_COMMON_FIXED_MODE_TYPES(SAT,NAME) \
2252   if (type1 == SAT ## NAME ## _type_node \
2253       || type1 == SAT ## u ## NAME ## _type_node) \
2254     return unsignedp ? SAT ## u ## NAME ## _type_node \
2255                      : SAT ## NAME ## _type_node;
2256
2257   C_COMMON_FIXED_TYPES (, fract);
2258   C_COMMON_FIXED_TYPES (sat_, fract);
2259   C_COMMON_FIXED_TYPES (, accum);
2260   C_COMMON_FIXED_TYPES (sat_, accum);
2261
2262   C_COMMON_FIXED_MODE_TYPES (, qq);
2263   C_COMMON_FIXED_MODE_TYPES (, hq);
2264   C_COMMON_FIXED_MODE_TYPES (, sq);
2265   C_COMMON_FIXED_MODE_TYPES (, dq);
2266   C_COMMON_FIXED_MODE_TYPES (, tq);
2267   C_COMMON_FIXED_MODE_TYPES (sat_, qq);
2268   C_COMMON_FIXED_MODE_TYPES (sat_, hq);
2269   C_COMMON_FIXED_MODE_TYPES (sat_, sq);
2270   C_COMMON_FIXED_MODE_TYPES (sat_, dq);
2271   C_COMMON_FIXED_MODE_TYPES (sat_, tq);
2272   C_COMMON_FIXED_MODE_TYPES (, ha);
2273   C_COMMON_FIXED_MODE_TYPES (, sa);
2274   C_COMMON_FIXED_MODE_TYPES (, da);
2275   C_COMMON_FIXED_MODE_TYPES (, ta);
2276   C_COMMON_FIXED_MODE_TYPES (sat_, ha);
2277   C_COMMON_FIXED_MODE_TYPES (sat_, sa);
2278   C_COMMON_FIXED_MODE_TYPES (sat_, da);
2279   C_COMMON_FIXED_MODE_TYPES (sat_, ta);
2280
2281   /* For ENUMERAL_TYPEs in C++, must check the mode of the types, not
2282      the precision; they have precision set to match their range, but
2283      may use a wider mode to match an ABI.  If we change modes, we may
2284      wind up with bad conversions.  For INTEGER_TYPEs in C, must check
2285      the precision as well, so as to yield correct results for
2286      bit-field types.  C++ does not have these separate bit-field
2287      types, and producing a signed or unsigned variant of an
2288      ENUMERAL_TYPE may cause other problems as well.  */
2289
2290   if (!INTEGRAL_TYPE_P (type)
2291       || TYPE_UNSIGNED (type) == unsignedp)
2292     return type;
2293
2294 #define TYPE_OK(node)                                                       \
2295   (TYPE_MODE (type) == TYPE_MODE (node)                                     \
2296    && (c_dialect_cxx () || TYPE_PRECISION (type) == TYPE_PRECISION (node)))
2297   if (TYPE_OK (signed_char_type_node))
2298     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2299   if (TYPE_OK (integer_type_node))
2300     return unsignedp ? unsigned_type_node : integer_type_node;
2301   if (TYPE_OK (short_integer_type_node))
2302     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2303   if (TYPE_OK (long_integer_type_node))
2304     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2305   if (TYPE_OK (long_long_integer_type_node))
2306     return (unsignedp ? long_long_unsigned_type_node
2307             : long_long_integer_type_node);
2308   if (TYPE_OK (widest_integer_literal_type_node))
2309     return (unsignedp ? widest_unsigned_literal_type_node
2310             : widest_integer_literal_type_node);
2311
2312 #if HOST_BITS_PER_WIDE_INT >= 64
2313   if (TYPE_OK (intTI_type_node))
2314     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
2315 #endif
2316   if (TYPE_OK (intDI_type_node))
2317     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
2318   if (TYPE_OK (intSI_type_node))
2319     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
2320   if (TYPE_OK (intHI_type_node))
2321     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
2322   if (TYPE_OK (intQI_type_node))
2323     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
2324 #undef TYPE_OK
2325
2326   if (c_dialect_cxx ())
2327     return type;
2328   else
2329     return build_nonstandard_integer_type (TYPE_PRECISION (type), unsignedp);
2330 }
2331
2332 /* Build a bit-field integer type for the given WIDTH and UNSIGNEDP.  */
2333
2334 tree
2335 c_build_bitfield_integer_type (unsigned HOST_WIDE_INT width, int unsignedp)
2336 {
2337   /* Extended integer types of the same width as a standard type have
2338      lesser rank, so those of the same width as int promote to int or
2339      unsigned int and are valid for printf formats expecting int or
2340      unsigned int.  To avoid such special cases, avoid creating
2341      extended integer types for bit-fields if a standard integer type
2342      is available.  */
2343   if (width == TYPE_PRECISION (integer_type_node))
2344     return unsignedp ? unsigned_type_node : integer_type_node;
2345   if (width == TYPE_PRECISION (signed_char_type_node))
2346     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
2347   if (width == TYPE_PRECISION (short_integer_type_node))
2348     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
2349   if (width == TYPE_PRECISION (long_integer_type_node))
2350     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
2351   if (width == TYPE_PRECISION (long_long_integer_type_node))
2352     return (unsignedp ? long_long_unsigned_type_node
2353             : long_long_integer_type_node);
2354   return build_nonstandard_integer_type (width, unsignedp);
2355 }
2356
2357 /* The C version of the register_builtin_type langhook.  */
2358
2359 void
2360 c_register_builtin_type (tree type, const char* name)
2361 {
2362   tree decl;
2363
2364   decl = build_decl (TYPE_DECL, get_identifier (name), type);
2365   DECL_ARTIFICIAL (decl) = 1;
2366   if (!TYPE_NAME (type))
2367     TYPE_NAME (type) = decl;
2368   pushdecl (decl);
2369
2370   registered_builtin_types = tree_cons (0, type, registered_builtin_types);
2371 }
2372
2373 \f
2374 /* Return the minimum number of bits needed to represent VALUE in a
2375    signed or unsigned type, UNSIGNEDP says which.  */
2376
2377 unsigned int
2378 min_precision (tree value, int unsignedp)
2379 {
2380   int log;
2381
2382   /* If the value is negative, compute its negative minus 1.  The latter
2383      adjustment is because the absolute value of the largest negative value
2384      is one larger than the largest positive value.  This is equivalent to
2385      a bit-wise negation, so use that operation instead.  */
2386
2387   if (tree_int_cst_sgn (value) < 0)
2388     value = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (value), value);
2389
2390   /* Return the number of bits needed, taking into account the fact
2391      that we need one more bit for a signed than unsigned type.  */
2392
2393   if (integer_zerop (value))
2394     log = 0;
2395   else
2396     log = tree_floor_log2 (value);
2397
2398   return log + 1 + !unsignedp;
2399 }
2400 \f
2401 /* Print an error message for invalid operands to arith operation
2402    CODE with TYPE0 for operand 0, and TYPE1 for operand 1.  */
2403
2404 void
2405 binary_op_error (enum tree_code code, tree type0, tree type1)
2406 {
2407   const char *opname;
2408
2409   switch (code)
2410     {
2411     case PLUS_EXPR:
2412       opname = "+"; break;
2413     case MINUS_EXPR:
2414       opname = "-"; break;
2415     case MULT_EXPR:
2416       opname = "*"; break;
2417     case MAX_EXPR:
2418       opname = "max"; break;
2419     case MIN_EXPR:
2420       opname = "min"; break;
2421     case EQ_EXPR:
2422       opname = "=="; break;
2423     case NE_EXPR:
2424       opname = "!="; break;
2425     case LE_EXPR:
2426       opname = "<="; break;
2427     case GE_EXPR:
2428       opname = ">="; break;
2429     case LT_EXPR:
2430       opname = "<"; break;
2431     case GT_EXPR:
2432       opname = ">"; break;
2433     case LSHIFT_EXPR:
2434       opname = "<<"; break;
2435     case RSHIFT_EXPR:
2436       opname = ">>"; break;
2437     case TRUNC_MOD_EXPR:
2438     case FLOOR_MOD_EXPR:
2439       opname = "%"; break;
2440     case TRUNC_DIV_EXPR:
2441     case FLOOR_DIV_EXPR:
2442       opname = "/"; break;
2443     case BIT_AND_EXPR:
2444       opname = "&"; break;
2445     case BIT_IOR_EXPR:
2446       opname = "|"; break;
2447     case TRUTH_ANDIF_EXPR:
2448       opname = "&&"; break;
2449     case TRUTH_ORIF_EXPR:
2450       opname = "||"; break;
2451     case BIT_XOR_EXPR:
2452       opname = "^"; break;
2453     default:
2454       gcc_unreachable ();
2455     }
2456   error ("invalid operands to binary %s (have %qT and %qT)", opname,
2457          type0, type1);
2458 }
2459 \f
2460 /* Subroutine of build_binary_op, used for comparison operations.
2461    See if the operands have both been converted from subword integer types
2462    and, if so, perhaps change them both back to their original type.
2463    This function is also responsible for converting the two operands
2464    to the proper common type for comparison.
2465
2466    The arguments of this function are all pointers to local variables
2467    of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
2468    RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.
2469
2470    If this function returns nonzero, it means that the comparison has
2471    a constant value.  What this function returns is an expression for
2472    that value.  */
2473
2474 tree
2475 shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr,
2476                  enum tree_code *rescode_ptr)
2477 {
2478   tree type;
2479   tree op0 = *op0_ptr;
2480   tree op1 = *op1_ptr;
2481   int unsignedp0, unsignedp1;
2482   int real1, real2;
2483   tree primop0, primop1;
2484   enum tree_code code = *rescode_ptr;
2485
2486   /* Throw away any conversions to wider types
2487      already present in the operands.  */
2488
2489   primop0 = get_narrower (op0, &unsignedp0);
2490   primop1 = get_narrower (op1, &unsignedp1);
2491
2492   /* Handle the case that OP0 does not *contain* a conversion
2493      but it *requires* conversion to FINAL_TYPE.  */
2494
2495   if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
2496     unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0));
2497   if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
2498     unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1));
2499
2500   /* If one of the operands must be floated, we cannot optimize.  */
2501   real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
2502   real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
2503
2504   /* If first arg is constant, swap the args (changing operation
2505      so value is preserved), for canonicalization.  Don't do this if
2506      the second arg is 0.  */
2507
2508   if (TREE_CONSTANT (primop0)
2509       && !integer_zerop (primop1) && !real_zerop (primop1)
2510       && !fixed_zerop (primop1))
2511     {
2512       tree tem = primop0;
2513       int temi = unsignedp0;
2514       primop0 = primop1;
2515       primop1 = tem;
2516       tem = op0;
2517       op0 = op1;
2518       op1 = tem;
2519       *op0_ptr = op0;
2520       *op1_ptr = op1;
2521       unsignedp0 = unsignedp1;
2522       unsignedp1 = temi;
2523       temi = real1;
2524       real1 = real2;
2525       real2 = temi;
2526
2527       switch (code)
2528         {
2529         case LT_EXPR:
2530           code = GT_EXPR;
2531           break;
2532         case GT_EXPR:
2533           code = LT_EXPR;
2534           break;
2535         case LE_EXPR:
2536           code = GE_EXPR;
2537           break;
2538         case GE_EXPR:
2539           code = LE_EXPR;
2540           break;
2541         default:
2542           break;
2543         }
2544       *rescode_ptr = code;
2545     }
2546
2547   /* If comparing an integer against a constant more bits wide,
2548      maybe we can deduce a value of 1 or 0 independent of the data.
2549      Or else truncate the constant now
2550      rather than extend the variable at run time.
2551
2552      This is only interesting if the constant is the wider arg.
2553      Also, it is not safe if the constant is unsigned and the
2554      variable arg is signed, since in this case the variable
2555      would be sign-extended and then regarded as unsigned.
2556      Our technique fails in this case because the lowest/highest
2557      possible unsigned results don't follow naturally from the
2558      lowest/highest possible values of the variable operand.
2559      For just EQ_EXPR and NE_EXPR there is another technique that
2560      could be used: see if the constant can be faithfully represented
2561      in the other operand's type, by truncating it and reextending it
2562      and see if that preserves the constant's value.  */
2563
2564   if (!real1 && !real2
2565       && TREE_CODE (TREE_TYPE (primop0)) != FIXED_POINT_TYPE
2566       && TREE_CODE (primop1) == INTEGER_CST
2567       && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
2568     {
2569       int min_gt, max_gt, min_lt, max_lt;
2570       tree maxval, minval;
2571       /* 1 if comparison is nominally unsigned.  */
2572       int unsignedp = TYPE_UNSIGNED (*restype_ptr);
2573       tree val;
2574
2575       type = c_common_signed_or_unsigned_type (unsignedp0,
2576                                                TREE_TYPE (primop0));
2577
2578       maxval = TYPE_MAX_VALUE (type);
2579       minval = TYPE_MIN_VALUE (type);
2580
2581       if (unsignedp && !unsignedp0)
2582         *restype_ptr = c_common_signed_type (*restype_ptr);
2583
2584       if (TREE_TYPE (primop1) != *restype_ptr)
2585         {
2586           /* Convert primop1 to target type, but do not introduce
2587              additional overflow.  We know primop1 is an int_cst.  */
2588           primop1 = force_fit_type_double (*restype_ptr,
2589                                            TREE_INT_CST_LOW (primop1),
2590                                            TREE_INT_CST_HIGH (primop1), 0,
2591                                            TREE_OVERFLOW (primop1));
2592         }
2593       if (type != *restype_ptr)
2594         {
2595           minval = convert (*restype_ptr, minval);
2596           maxval = convert (*restype_ptr, maxval);
2597         }
2598
2599       if (unsignedp && unsignedp0)
2600         {
2601           min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
2602           max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
2603           min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
2604           max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
2605         }
2606       else
2607         {
2608           min_gt = INT_CST_LT (primop1, minval);
2609           max_gt = INT_CST_LT (primop1, maxval);
2610           min_lt = INT_CST_LT (minval, primop1);
2611           max_lt = INT_CST_LT (maxval, primop1);
2612         }
2613
2614       val = 0;
2615       /* This used to be a switch, but Genix compiler can't handle that.  */
2616       if (code == NE_EXPR)
2617         {
2618           if (max_lt || min_gt)
2619             val = truthvalue_true_node;
2620         }
2621       else if (code == EQ_EXPR)
2622         {
2623           if (max_lt || min_gt)
2624             val = truthvalue_false_node;
2625         }
2626       else if (code == LT_EXPR)
2627         {
2628           if (max_lt)
2629             val = truthvalue_true_node;
2630           if (!min_lt)
2631             val = truthvalue_false_node;
2632         }
2633       else if (code == GT_EXPR)
2634         {
2635           if (min_gt)
2636             val = truthvalue_true_node;
2637           if (!max_gt)
2638             val = truthvalue_false_node;
2639         }
2640       else if (code == LE_EXPR)
2641         {
2642           if (!max_gt)
2643             val = truthvalue_true_node;
2644           if (min_gt)
2645             val = truthvalue_false_node;
2646         }
2647       else if (code == GE_EXPR)
2648         {
2649           if (!min_lt)
2650             val = truthvalue_true_node;
2651           if (max_lt)
2652             val = truthvalue_false_node;
2653         }
2654
2655       /* If primop0 was sign-extended and unsigned comparison specd,
2656          we did a signed comparison above using the signed type bounds.
2657          But the comparison we output must be unsigned.
2658
2659          Also, for inequalities, VAL is no good; but if the signed
2660          comparison had *any* fixed result, it follows that the
2661          unsigned comparison just tests the sign in reverse
2662          (positive values are LE, negative ones GE).
2663          So we can generate an unsigned comparison
2664          against an extreme value of the signed type.  */
2665
2666       if (unsignedp && !unsignedp0)
2667         {
2668           if (val != 0)
2669             switch (code)
2670               {
2671               case LT_EXPR:
2672               case GE_EXPR:
2673                 primop1 = TYPE_MIN_VALUE (type);
2674                 val = 0;
2675                 break;
2676
2677               case LE_EXPR:
2678               case GT_EXPR:
2679                 primop1 = TYPE_MAX_VALUE (type);
2680                 val = 0;
2681                 break;
2682
2683               default:
2684                 break;
2685               }
2686           type = c_common_unsigned_type (type);
2687         }
2688
2689       if (TREE_CODE (primop0) != INTEGER_CST)
2690         {
2691           if (val == truthvalue_false_node)
2692             warning (OPT_Wtype_limits, "comparison is always false due to limited range of data type");
2693           if (val == truthvalue_true_node)
2694             warning (OPT_Wtype_limits, "comparison is always true due to limited range of data type");
2695         }
2696
2697       if (val != 0)
2698         {
2699           /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2700           if (TREE_SIDE_EFFECTS (primop0))
2701             return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
2702           return val;
2703         }
2704
2705       /* Value is not predetermined, but do the comparison
2706          in the type of the operand that is not constant.
2707          TYPE is already properly set.  */
2708     }
2709
2710   /* If either arg is decimal float and the other is float, find the
2711      proper common type to use for comparison.  */
2712   else if (real1 && real2
2713            && (DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop0)))
2714                || DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop1)))))
2715     type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
2716
2717   else if (real1 && real2
2718            && (TYPE_PRECISION (TREE_TYPE (primop0))
2719                == TYPE_PRECISION (TREE_TYPE (primop1))))
2720     type = TREE_TYPE (primop0);
2721
2722   /* If args' natural types are both narrower than nominal type
2723      and both extend in the same manner, compare them
2724      in the type of the wider arg.
2725      Otherwise must actually extend both to the nominal
2726      common type lest different ways of extending
2727      alter the result.
2728      (eg, (short)-1 == (unsigned short)-1  should be 0.)  */
2729
2730   else if (unsignedp0 == unsignedp1 && real1 == real2
2731            && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
2732            && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
2733     {
2734       type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
2735       type = c_common_signed_or_unsigned_type (unsignedp0
2736                                                || TYPE_UNSIGNED (*restype_ptr),
2737                                                type);
2738       /* Make sure shorter operand is extended the right way
2739          to match the longer operand.  */
2740       primop0
2741         = convert (c_common_signed_or_unsigned_type (unsignedp0,
2742                                                      TREE_TYPE (primop0)),
2743                    primop0);
2744       primop1
2745         = convert (c_common_signed_or_unsigned_type (unsignedp1,
2746                                                      TREE_TYPE (primop1)),
2747                    primop1);
2748     }
2749   else
2750     {
2751       /* Here we must do the comparison on the nominal type
2752          using the args exactly as we received them.  */
2753       type = *restype_ptr;
2754       primop0 = op0;
2755       primop1 = op1;
2756
2757       if (!real1 && !real2 && integer_zerop (primop1)
2758           && TYPE_UNSIGNED (*restype_ptr))
2759         {
2760           tree value = 0;
2761           switch (code)
2762             {
2763             case GE_EXPR:
2764               /* All unsigned values are >= 0, so we warn.  However,
2765                  if OP0 is a constant that is >= 0, the signedness of
2766                  the comparison isn't an issue, so suppress the
2767                  warning.  */
2768               if (warn_type_limits && !in_system_header
2769                   && !(TREE_CODE (primop0) == INTEGER_CST
2770                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
2771                                                    primop0))))
2772                 warning (OPT_Wtype_limits,
2773                          "comparison of unsigned expression >= 0 is always true");
2774               value = truthvalue_true_node;
2775               break;
2776
2777             case LT_EXPR:
2778               if (warn_type_limits && !in_system_header
2779                   && !(TREE_CODE (primop0) == INTEGER_CST
2780                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
2781                                                    primop0))))
2782                 warning (OPT_Wtype_limits,
2783                          "comparison of unsigned expression < 0 is always false");
2784               value = truthvalue_false_node;
2785               break;
2786
2787             default:
2788               break;
2789             }
2790
2791           if (value != 0)
2792             {
2793               /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2794               if (TREE_SIDE_EFFECTS (primop0))
2795                 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2796                                primop0, value);
2797               return value;
2798             }
2799         }
2800     }
2801
2802   *op0_ptr = convert (type, primop0);
2803   *op1_ptr = convert (type, primop1);
2804
2805   *restype_ptr = truthvalue_type_node;
2806
2807   return 0;
2808 }
2809 \f
2810 /* Return a tree for the sum or difference (RESULTCODE says which)
2811    of pointer PTROP and integer INTOP.  */
2812
2813 tree
2814 pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
2815 {
2816   tree size_exp, ret;
2817
2818   /* The result is a pointer of the same type that is being added.  */
2819   tree result_type = TREE_TYPE (ptrop);
2820
2821   if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
2822     {
2823       if (pedantic || warn_pointer_arith)
2824         pedwarn ("pointer of type %<void *%> used in arithmetic");
2825       size_exp = integer_one_node;
2826     }
2827   else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE)
2828     {
2829       if (pedantic || warn_pointer_arith)
2830         pedwarn ("pointer to a function used in arithmetic");
2831       size_exp = integer_one_node;
2832     }
2833   else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE)
2834     {
2835       if (pedantic || warn_pointer_arith)
2836         pedwarn ("pointer to member function used in arithmetic");
2837       size_exp = integer_one_node;
2838     }
2839   else
2840     size_exp = size_in_bytes (TREE_TYPE (result_type));
2841
2842   /* We are manipulating pointer values, so we don't need to warn
2843      about relying on undefined signed overflow.  We disable the
2844      warning here because we use integer types so fold won't know that
2845      they are really pointers.  */
2846   fold_defer_overflow_warnings ();
2847
2848   /* If what we are about to multiply by the size of the elements
2849      contains a constant term, apply distributive law
2850      and multiply that constant term separately.
2851      This helps produce common subexpressions.  */
2852   if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
2853       && !TREE_CONSTANT (intop)
2854       && TREE_CONSTANT (TREE_OPERAND (intop, 1))
2855       && TREE_CONSTANT (size_exp)
2856       /* If the constant comes from pointer subtraction,
2857          skip this optimization--it would cause an error.  */
2858       && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
2859       /* If the constant is unsigned, and smaller than the pointer size,
2860          then we must skip this optimization.  This is because it could cause
2861          an overflow error if the constant is negative but INTOP is not.  */
2862       && (!TYPE_UNSIGNED (TREE_TYPE (intop))
2863           || (TYPE_PRECISION (TREE_TYPE (intop))
2864               == TYPE_PRECISION (TREE_TYPE (ptrop)))))
2865     {
2866       enum tree_code subcode = resultcode;
2867       tree int_type = TREE_TYPE (intop);
2868       if (TREE_CODE (intop) == MINUS_EXPR)
2869         subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
2870       /* Convert both subexpression types to the type of intop,
2871          because weird cases involving pointer arithmetic
2872          can result in a sum or difference with different type args.  */
2873       ptrop = build_binary_op (subcode, ptrop,
2874                                convert (int_type, TREE_OPERAND (intop, 1)), 1);
2875       intop = convert (int_type, TREE_OPERAND (intop, 0));
2876     }
2877
2878   /* Convert the integer argument to a type the same size as sizetype
2879      so the multiply won't overflow spuriously.  */
2880   if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype)
2881       || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype))
2882     intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype),
2883                                              TYPE_UNSIGNED (sizetype)), intop);
2884
2885   /* Replace the integer argument with a suitable product by the object size.
2886      Do this multiplication as signed, then convert to the appropriate
2887      type for the pointer operation.  */
2888   intop = convert (sizetype,
2889                    build_binary_op (MULT_EXPR, intop,
2890                                     convert (TREE_TYPE (intop), size_exp), 1));
2891
2892   /* Create the sum or difference.  */
2893   if (resultcode == MINUS_EXPR)
2894     intop = fold_build1 (NEGATE_EXPR, sizetype, intop);
2895
2896   ret = fold_build2 (POINTER_PLUS_EXPR, result_type, ptrop, intop);
2897
2898   fold_undefer_and_ignore_overflow_warnings ();
2899
2900   return ret;
2901 }
2902 \f
2903 /* Return whether EXPR is a declaration whose address can never be
2904    NULL.  */
2905
2906 bool
2907 decl_with_nonnull_addr_p (const_tree expr)
2908 {
2909   return (DECL_P (expr)
2910           && (TREE_CODE (expr) == PARM_DECL
2911               || TREE_CODE (expr) == LABEL_DECL
2912               || !DECL_WEAK (expr)));
2913 }
2914
2915 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
2916    or for an `if' or `while' statement or ?..: exp.  It should already
2917    have been validated to be of suitable type; otherwise, a bad
2918    diagnostic may result.
2919
2920    This preparation consists of taking the ordinary
2921    representation of an expression expr and producing a valid tree
2922    boolean expression describing whether expr is nonzero.  We could
2923    simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1),
2924    but we optimize comparisons, &&, ||, and !.
2925
2926    The resulting type should always be `truthvalue_type_node'.  */
2927
2928 tree
2929 c_common_truthvalue_conversion (tree expr)
2930 {
2931   switch (TREE_CODE (expr))
2932     {
2933     case EQ_EXPR:   case NE_EXPR:   case UNEQ_EXPR: case LTGT_EXPR:
2934     case LE_EXPR:   case GE_EXPR:   case LT_EXPR:   case GT_EXPR:
2935     case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR:
2936     case ORDERED_EXPR: case UNORDERED_EXPR:
2937       if (TREE_TYPE (expr) == truthvalue_type_node)
2938         return expr;
2939       return build2 (TREE_CODE (expr), truthvalue_type_node,
2940                      TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1));
2941
2942     case TRUTH_ANDIF_EXPR:
2943     case TRUTH_ORIF_EXPR:
2944     case TRUTH_AND_EXPR:
2945     case TRUTH_OR_EXPR:
2946     case TRUTH_XOR_EXPR:
2947       if (TREE_TYPE (expr) == truthvalue_type_node)
2948         return expr;
2949       return build2 (TREE_CODE (expr), truthvalue_type_node,
2950                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)),
2951                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)));
2952
2953     case TRUTH_NOT_EXPR:
2954       if (TREE_TYPE (expr) == truthvalue_type_node)
2955         return expr;
2956       return build1 (TREE_CODE (expr), truthvalue_type_node,
2957                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)));
2958
2959     case ERROR_MARK:
2960       return expr;
2961
2962     case INTEGER_CST:
2963       return integer_zerop (expr) ? truthvalue_false_node
2964                                   : truthvalue_true_node;
2965
2966     case REAL_CST:
2967       return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0)
2968              ? truthvalue_true_node
2969              : truthvalue_false_node;
2970
2971     case FIXED_CST:
2972       return fixed_compare (NE_EXPR, &TREE_FIXED_CST (expr),
2973                             &FCONST0 (TYPE_MODE (TREE_TYPE (expr))))
2974              ? truthvalue_true_node
2975              : truthvalue_false_node;
2976
2977     case FUNCTION_DECL:
2978       expr = build_unary_op (ADDR_EXPR, expr, 0);
2979       /* Fall through.  */
2980
2981     case ADDR_EXPR:
2982       {
2983         tree inner = TREE_OPERAND (expr, 0);
2984         if (decl_with_nonnull_addr_p (inner))
2985           {
2986             /* Common Ada/Pascal programmer's mistake.  */
2987             warning (OPT_Waddress,
2988                      "the address of %qD will always evaluate as %<true%>",
2989                      inner);
2990             return truthvalue_true_node;
2991           }
2992
2993         /* If we still have a decl, it is possible for its address to
2994            be NULL, so we cannot optimize.  */
2995         if (DECL_P (inner))
2996           {
2997             gcc_assert (DECL_WEAK (inner));
2998             break;
2999           }
3000
3001         if (TREE_SIDE_EFFECTS (inner))
3002           return build2 (COMPOUND_EXPR, truthvalue_type_node,
3003                          inner, truthvalue_true_node);
3004         else
3005           return truthvalue_true_node;
3006       }
3007
3008     case COMPLEX_EXPR:
3009       return build_binary_op ((TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
3010                                ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
3011                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)),
3012                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
3013                               0);
3014
3015     case NEGATE_EXPR:
3016     case ABS_EXPR:
3017     case FLOAT_EXPR:
3018       /* These don't change whether an object is nonzero or zero.  */
3019       return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
3020
3021     case LROTATE_EXPR:
3022     case RROTATE_EXPR:
3023       /* These don't change whether an object is zero or nonzero, but
3024          we can't ignore them if their second arg has side-effects.  */
3025       if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
3026         return build2 (COMPOUND_EXPR, truthvalue_type_node,
3027                        TREE_OPERAND (expr, 1),
3028                        c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)));
3029       else
3030         return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
3031
3032     case COND_EXPR:
3033       /* Distribute the conversion into the arms of a COND_EXPR.  */
3034       return fold_build3 (COND_EXPR, truthvalue_type_node,
3035                 TREE_OPERAND (expr, 0),
3036                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
3037                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 2)));
3038
3039     case CONVERT_EXPR:
3040     case NOP_EXPR:
3041       /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
3042          since that affects how `default_conversion' will behave.  */
3043       if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
3044           || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
3045         break;
3046       /* If this is widening the argument, we can ignore it.  */
3047       if (TYPE_PRECISION (TREE_TYPE (expr))
3048           >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
3049         return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
3050       break;
3051
3052     case MODIFY_EXPR:
3053       if (!TREE_NO_WARNING (expr)
3054           && warn_parentheses)
3055         {
3056           warning (OPT_Wparentheses,
3057                    "suggest parentheses around assignment used as truth value");
3058           TREE_NO_WARNING (expr) = 1;
3059         }
3060       break;
3061
3062     default:
3063       break;
3064     }
3065
3066   if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
3067     {
3068       tree t = save_expr (expr);
3069       return (build_binary_op
3070               ((TREE_SIDE_EFFECTS (expr)
3071                 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
3072         c_common_truthvalue_conversion (build_unary_op (REALPART_EXPR, t, 0)),
3073         c_common_truthvalue_conversion (build_unary_op (IMAGPART_EXPR, t, 0)),
3074                0));
3075     }
3076
3077   if (TREE_CODE (TREE_TYPE (expr)) == FIXED_POINT_TYPE)
3078     {
3079       tree fixed_zero_node = build_fixed (TREE_TYPE (expr),
3080                                           FCONST0 (TYPE_MODE
3081                                                    (TREE_TYPE (expr))));
3082       return build_binary_op (NE_EXPR, expr, fixed_zero_node, 1);
3083     }
3084
3085   return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3086 }
3087 \f
3088 static void def_builtin_1  (enum built_in_function fncode,
3089                             const char *name,
3090                             enum built_in_class fnclass,
3091                             tree fntype, tree libtype,
3092                             bool both_p, bool fallback_p, bool nonansi_p,
3093                             tree fnattrs, bool implicit_p);
3094
3095
3096 /* Apply the TYPE_QUALS to the new DECL.  */
3097
3098 void
3099 c_apply_type_quals_to_decl (int type_quals, tree decl)
3100 {
3101   tree type = TREE_TYPE (decl);
3102
3103   if (type == error_mark_node)
3104     return;
3105
3106   if (((type_quals & TYPE_QUAL_CONST)
3107        || (type && TREE_CODE (type) == REFERENCE_TYPE))
3108       /* An object declared 'const' is only readonly after it is
3109          initialized.  We don't have any way of expressing this currently,
3110          so we need to be conservative and unset TREE_READONLY for types
3111          with constructors.  Otherwise aliasing code will ignore stores in
3112          an inline constructor.  */
3113       && !(type && TYPE_NEEDS_CONSTRUCTING (type)))
3114     TREE_READONLY (decl) = 1;
3115   if (type_quals & TYPE_QUAL_VOLATILE)
3116     {
3117       TREE_SIDE_EFFECTS (decl) = 1;
3118       TREE_THIS_VOLATILE (decl) = 1;
3119     }
3120   if (type_quals & TYPE_QUAL_RESTRICT)
3121     {
3122       while (type && TREE_CODE (type) == ARRAY_TYPE)
3123         /* Allow 'restrict' on arrays of pointers.
3124            FIXME currently we just ignore it.  */
3125         type = TREE_TYPE (type);
3126       if (!type
3127           || !POINTER_TYPE_P (type)
3128           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))
3129         error ("invalid use of %<restrict%>");
3130       else if (flag_strict_aliasing && type == TREE_TYPE (decl))
3131         /* Indicate we need to make a unique alias set for this pointer.
3132            We can't do it here because it might be pointing to an
3133            incomplete type.  */
3134         DECL_POINTER_ALIAS_SET (decl) = -2;
3135     }
3136 }
3137
3138 /* Hash function for the problem of multiple type definitions in
3139    different files.  This must hash all types that will compare
3140    equal via comptypes to the same value.  In practice it hashes
3141    on some of the simple stuff and leaves the details to comptypes.  */
3142
3143 static hashval_t
3144 c_type_hash (const void *p)
3145 {
3146   int i = 0;
3147   int shift, size;
3148   const_tree const t = (const_tree) p;
3149   tree t2;
3150   switch (TREE_CODE (t))
3151     {
3152     /* For pointers, hash on pointee type plus some swizzling.  */
3153     case POINTER_TYPE:
3154       return c_type_hash (TREE_TYPE (t)) ^ 0x3003003;
3155     /* Hash on number of elements and total size.  */
3156     case ENUMERAL_TYPE:
3157       shift = 3;
3158       t2 = TYPE_VALUES (t);
3159       break;
3160     case RECORD_TYPE:
3161       shift = 0;
3162       t2 = TYPE_FIELDS (t);
3163       break;
3164     case QUAL_UNION_TYPE:
3165       shift = 1;
3166       t2 = TYPE_FIELDS (t);
3167       break;
3168     case UNION_TYPE:
3169       shift = 2;
3170       t2 = TYPE_FIELDS (t);
3171       break;
3172     default:
3173       gcc_unreachable ();
3174     }
3175   for (; t2; t2 = TREE_CHAIN (t2))
3176     i++;
3177   /* We might have a VLA here.  */
3178   if (TREE_CODE (TYPE_SIZE (t)) != INTEGER_CST)
3179     size = 0;
3180   else
3181     size = TREE_INT_CST_LOW (TYPE_SIZE (t));
3182   return ((size << 24) | (i << shift));
3183 }
3184
3185 static GTY((param_is (union tree_node))) htab_t type_hash_table;
3186
3187 /* Return the typed-based alias set for T, which may be an expression
3188    or a type.  Return -1 if we don't do anything special.  */
3189
3190 alias_set_type
3191 c_common_get_alias_set (tree t)
3192 {
3193   tree u;
3194   PTR *slot;
3195
3196   /* Permit type-punning when accessing a union, provided the access
3197      is directly through the union.  For example, this code does not
3198      permit taking the address of a union member and then storing
3199      through it.  Even the type-punning allowed here is a GCC
3200      extension, albeit a common and useful one; the C standard says
3201      that such accesses have implementation-defined behavior.  */
3202   for (u = t;
3203        TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
3204        u = TREE_OPERAND (u, 0))
3205     if (TREE_CODE (u) == COMPONENT_REF
3206         && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
3207       return 0;
3208
3209   /* That's all the expressions we handle specially.  */
3210   if (!TYPE_P (t))
3211     return -1;
3212
3213   /* The C standard guarantees that any object may be accessed via an
3214      lvalue that has character type.  */
3215   if (t == char_type_node
3216       || t == signed_char_type_node
3217       || t == unsigned_char_type_node)
3218     return 0;
3219
3220   /* If it has the may_alias attribute, it can alias anything.  */
3221   if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (t)))
3222     return 0;
3223
3224   /* The C standard specifically allows aliasing between signed and
3225      unsigned variants of the same type.  We treat the signed
3226      variant as canonical.  */
3227   if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t))
3228     {
3229       tree t1 = c_common_signed_type (t);
3230
3231       /* t1 == t can happen for boolean nodes which are always unsigned.  */
3232       if (t1 != t)
3233         return get_alias_set (t1);
3234     }
3235   else if (POINTER_TYPE_P (t))
3236     {
3237       tree t1;
3238
3239       /* Unfortunately, there is no canonical form of a pointer type.
3240          In particular, if we have `typedef int I', then `int *', and
3241          `I *' are different types.  So, we have to pick a canonical
3242          representative.  We do this below.
3243
3244          Technically, this approach is actually more conservative that
3245          it needs to be.  In particular, `const int *' and `int *'
3246          should be in different alias sets, according to the C and C++
3247          standard, since their types are not the same, and so,
3248          technically, an `int **' and `const int **' cannot point at
3249          the same thing.
3250
3251          But, the standard is wrong.  In particular, this code is
3252          legal C++:
3253
3254             int *ip;
3255             int **ipp = &ip;
3256             const int* const* cipp = ipp;
3257
3258          And, it doesn't make sense for that to be legal unless you
3259          can dereference IPP and CIPP.  So, we ignore cv-qualifiers on
3260          the pointed-to types.  This issue has been reported to the
3261          C++ committee.  */
3262       t1 = build_type_no_quals (t);
3263       if (t1 != t)
3264         return get_alias_set (t1);
3265     }
3266
3267   /* Handle the case of multiple type nodes referring to "the same" type,
3268      which occurs with IMA.  These share an alias set.  FIXME:  Currently only
3269      C90 is handled.  (In C99 type compatibility is not transitive, which
3270      complicates things mightily. The alias set splay trees can theoretically
3271      represent this, but insertion is tricky when you consider all the
3272      different orders things might arrive in.) */
3273
3274   if (c_language != clk_c || flag_isoc99)
3275     return -1;
3276
3277   /* Save time if there's only one input file.  */
3278   if (num_in_fnames == 1)
3279     return -1;
3280
3281   /* Pointers need special handling if they point to any type that
3282      needs special handling (below).  */
3283   if (TREE_CODE (t) == POINTER_TYPE)
3284     {
3285       tree t2;
3286       /* Find bottom type under any nested POINTERs.  */
3287       for (t2 = TREE_TYPE (t);
3288            TREE_CODE (t2) == POINTER_TYPE;
3289            t2 = TREE_TYPE (t2))
3290         ;
3291       if (TREE_CODE (t2) != RECORD_TYPE
3292           && TREE_CODE (t2) != ENUMERAL_TYPE
3293           && TREE_CODE (t2) != QUAL_UNION_TYPE
3294           && TREE_CODE (t2) != UNION_TYPE)
3295         return -1;
3296       if (TYPE_SIZE (t2) == 0)
3297         return -1;
3298     }
3299   /* These are the only cases that need special handling.  */
3300   if (TREE_CODE (t) != RECORD_TYPE
3301       && TREE_CODE (t) != ENUMERAL_TYPE
3302       && TREE_CODE (t) != QUAL_UNION_TYPE
3303       && TREE_CODE (t) != UNION_TYPE
3304       && TREE_CODE (t) != POINTER_TYPE)
3305     return -1;
3306   /* Undefined? */
3307   if (TYPE_SIZE (t) == 0)
3308     return -1;
3309
3310   /* Look up t in hash table.  Only one of the compatible types within each
3311      alias set is recorded in the table.  */
3312   if (!type_hash_table)
3313     type_hash_table = htab_create_ggc (1021, c_type_hash,
3314             (htab_eq) lang_hooks.types_compatible_p,
3315             NULL);
3316   slot = htab_find_slot (type_hash_table, t, INSERT);
3317   if (*slot != NULL)
3318     {
3319       TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot);
3320       return TYPE_ALIAS_SET ((tree)*slot);
3321     }
3322   else
3323     /* Our caller will assign and record (in t) a new alias set; all we need
3324        to do is remember t in the hash table.  */
3325     *slot = t;
3326
3327   return -1;
3328 }
3329 \f
3330 /* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where the
3331    second parameter indicates which OPERATOR is being applied.  The COMPLAIN
3332    flag controls whether we should diagnose possibly ill-formed
3333    constructs or not.  */
3334
3335 tree
3336 c_sizeof_or_alignof_type (tree type, bool is_sizeof, int complain)
3337 {
3338   const char *op_name;
3339   tree value = NULL;
3340   enum tree_code type_code = TREE_CODE (type);
3341
3342   op_name = is_sizeof ? "sizeof" : "__alignof__";
3343
3344   if (type_code == FUNCTION_TYPE)
3345     {
3346       if (is_sizeof)
3347         {
3348           if (complain && (pedantic || warn_pointer_arith))
3349             pedwarn ("invalid application of %<sizeof%> to a function type");
3350           value = size_one_node;
3351         }
3352       else
3353         value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);
3354     }
3355   else if (type_code == VOID_TYPE || type_code == ERROR_MARK)
3356     {
3357       if (type_code == VOID_TYPE
3358           && complain && (pedantic || warn_pointer_arith))
3359         pedwarn ("invalid application of %qs to a void type", op_name);
3360       value = size_one_node;
3361     }
3362   else if (!COMPLETE_TYPE_P (type))
3363     {
3364       if (complain)
3365         error ("invalid application of %qs to incomplete type %qT ",
3366                op_name, type);
3367       value = size_zero_node;
3368     }
3369   else
3370     {
3371       if (is_sizeof)
3372         /* Convert in case a char is more than one unit.  */
3373         value = size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
3374                             size_int (TYPE_PRECISION (char_type_node)
3375                                       / BITS_PER_UNIT));
3376       else
3377         value = size_int (TYPE_ALIGN_UNIT (type));
3378     }
3379
3380   /* VALUE will have an integer type with TYPE_IS_SIZETYPE set.
3381      TYPE_IS_SIZETYPE means that certain things (like overflow) will
3382      never happen.  However, this node should really have type
3383      `size_t', which is just a typedef for an ordinary integer type.  */
3384   value = fold_convert (size_type_node, value);
3385   gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value)));
3386
3387   return value;
3388 }
3389
3390 /* Implement the __alignof keyword: Return the minimum required
3391    alignment of EXPR, measured in bytes.  For VAR_DECLs,
3392    FUNCTION_DECLs and FIELD_DECLs return DECL_ALIGN (which can be set
3393    from an "aligned" __attribute__ specification).  */
3394
3395 tree
3396 c_alignof_expr (tree expr)
3397 {
3398   tree t;
3399
3400   if (VAR_OR_FUNCTION_DECL_P (expr))
3401     t = size_int (DECL_ALIGN_UNIT (expr));
3402
3403   else if (TREE_CODE (expr) == COMPONENT_REF
3404            && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1)))
3405     {
3406       error ("%<__alignof%> applied to a bit-field");
3407       t = size_one_node;
3408     }
3409   else if (TREE_CODE (expr) == COMPONENT_REF
3410            && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL)
3411     t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1)));
3412
3413   else if (TREE_CODE (expr) == INDIRECT_REF)
3414     {
3415       tree t = TREE_OPERAND (expr, 0);
3416       tree best = t;
3417       int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
3418
3419       while ((TREE_CODE (t) == NOP_EXPR || TREE_CODE (t) == CONVERT_EXPR)
3420              && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE)
3421         {
3422           int thisalign;
3423
3424           t = TREE_OPERAND (t, 0);
3425           thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
3426           if (thisalign > bestalign)
3427             best = t, bestalign = thisalign;
3428         }
3429       return c_alignof (TREE_TYPE (TREE_TYPE (best)));
3430     }
3431   else
3432     return c_alignof (TREE_TYPE (expr));
3433
3434   return fold_convert (size_type_node, t);
3435 }
3436 \f
3437 /* Handle C and C++ default attributes.  */
3438
3439 enum built_in_attribute
3440 {
3441 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
3442 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
3443 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
3444 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
3445 #include "builtin-attrs.def"
3446 #undef DEF_ATTR_NULL_TREE
3447 #undef DEF_ATTR_INT
3448 #undef DEF_ATTR_IDENT
3449 #undef DEF_ATTR_TREE_LIST
3450   ATTR_LAST
3451 };
3452
3453 static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
3454
3455 static void c_init_attributes (void);
3456
3457 enum c_builtin_type
3458 {
3459 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
3460 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
3461 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
3462 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
3463 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
3464 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
3465 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
3466 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) NAME,
3467 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7) NAME,
3468 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
3469 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
3470 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
3471 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
3472 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
3473 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \
3474   NAME,
3475 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
3476 #include "builtin-types.def"
3477 #undef DEF_PRIMITIVE_TYPE
3478 #undef DEF_FUNCTION_TYPE_0
3479 #undef DEF_FUNCTION_TYPE_1
3480 #undef DEF_FUNCTION_TYPE_2
3481 #undef DEF_FUNCTION_TYPE_3
3482 #undef DEF_FUNCTION_TYPE_4
3483 #undef DEF_FUNCTION_TYPE_5
3484 #undef DEF_FUNCTION_TYPE_6
3485 #undef DEF_FUNCTION_TYPE_7
3486 #undef DEF_FUNCTION_TYPE_VAR_0
3487 #undef DEF_FUNCTION_TYPE_VAR_1
3488 #undef DEF_FUNCTION_TYPE_VAR_2
3489 #undef DEF_FUNCTION_TYPE_VAR_3
3490 #undef DEF_FUNCTION_TYPE_VAR_4
3491 #undef DEF_FUNCTION_TYPE_VAR_5
3492 #undef DEF_POINTER_TYPE
3493   BT_LAST
3494 };
3495
3496 typedef enum c_builtin_type builtin_type;
3497
3498 /* A temporary array for c_common_nodes_and_builtins.  Used in
3499    communication with def_fn_type.  */
3500 static tree builtin_types[(int) BT_LAST + 1];
3501
3502 /* A helper function for c_common_nodes_and_builtins.  Build function type
3503    for DEF with return type RET and N arguments.  If VAR is true, then the
3504    function should be variadic after those N arguments.
3505
3506    Takes special care not to ICE if any of the types involved are
3507    error_mark_node, which indicates that said type is not in fact available
3508    (see builtin_type_for_size).  In which case the function type as a whole
3509    should be error_mark_node.  */
3510
3511 static void
3512 def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...)
3513 {
3514   tree args = NULL, t;
3515   va_list list;
3516   int i;
3517
3518   va_start (list, n);
3519   for (i = 0; i < n; ++i)
3520     {
3521       builtin_type a = va_arg (list, builtin_type);
3522       t = builtin_types[a];
3523       if (t == error_mark_node)
3524         goto egress;
3525       args = tree_cons (NULL_TREE, t, args);
3526     }
3527   va_end (list);
3528
3529   args = nreverse (args);
3530   if (!var)
3531     args = chainon (args, void_list_node);
3532
3533   t = builtin_types[ret];
3534   if (t == error_mark_node)
3535     goto egress;
3536   t = build_function_type (t, args);
3537
3538  egress:
3539   builtin_types[def] = t;
3540 }
3541
3542 /* Build builtin functions common to both C and C++ language
3543    frontends.  */
3544
3545 static void
3546 c_define_builtins (tree va_list_ref_type_node, tree va_list_arg_type_node)
3547 {
3548 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
3549   builtin_types[ENUM] = VALUE;
3550 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
3551   def_fn_type (ENUM, RETURN, 0, 0);
3552 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
3553   def_fn_type (ENUM, RETURN, 0, 1, ARG1);
3554 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
3555   def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
3556 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
3557   def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
3558 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
3559   def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
3560 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
3561   def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
3562 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
3563                             ARG6)                                       \
3564   def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
3565 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
3566                             ARG6, ARG7)                                 \
3567   def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
3568 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
3569   def_fn_type (ENUM, RETURN, 1, 0);
3570 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
3571   def_fn_type (ENUM, RETURN, 1, 1, ARG1);
3572 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
3573   def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
3574 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
3575   def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
3576 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
3577   def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
3578 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
3579   def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
3580 #define DEF_POINTER_TYPE(ENUM, TYPE) \
3581   builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
3582
3583 #include "builtin-types.def"
3584
3585 #undef DEF_PRIMITIVE_TYPE
3586 #undef DEF_FUNCTION_TYPE_1
3587 #undef DEF_FUNCTION_TYPE_2
3588 #undef DEF_FUNCTION_TYPE_3
3589 #undef DEF_FUNCTION_TYPE_4
3590 #undef DEF_FUNCTION_TYPE_5
3591 #undef DEF_FUNCTION_TYPE_6
3592 #undef DEF_FUNCTION_TYPE_VAR_0
3593 #undef DEF_FUNCTION_TYPE_VAR_1
3594 #undef DEF_FUNCTION_TYPE_VAR_2
3595 #undef DEF_FUNCTION_TYPE_VAR_3
3596 #undef DEF_FUNCTION_TYPE_VAR_4
3597 #undef DEF_FUNCTION_TYPE_VAR_5
3598 #undef DEF_POINTER_TYPE
3599   builtin_types[(int) BT_LAST] = NULL_TREE;
3600
3601   c_init_attributes ();
3602
3603 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
3604                     NONANSI_P, ATTRS, IMPLICIT, COND)                   \
3605   if (NAME && COND)                                                     \
3606     def_builtin_1 (ENUM, NAME, CLASS,                                   \
3607                    builtin_types[(int) TYPE],                           \
3608                    builtin_types[(int) LIBTYPE],                        \
3609                    BOTH_P, FALLBACK_P, NONANSI_P,                       \
3610                    built_in_attributes[(int) ATTRS], IMPLICIT);
3611 #include "builtins.def"
3612 #undef DEF_BUILTIN
3613
3614   targetm.init_builtins ();
3615
3616   build_common_builtin_nodes ();
3617
3618   if (flag_mudflap)
3619     mudflap_init ();
3620 }
3621
3622 /* Build tree nodes and builtin functions common to both C and C++ language
3623    frontends.  */
3624
3625 void
3626 c_common_nodes_and_builtins (void)
3627 {
3628   int wchar_type_size;
3629   tree array_domain_type;
3630   tree va_list_ref_type_node;
3631   tree va_list_arg_type_node;
3632
3633   /* Define `int' and `char' first so that dbx will output them first.  */
3634   record_builtin_type (RID_INT, NULL, integer_type_node);
3635   record_builtin_type (RID_CHAR, "char", char_type_node);
3636
3637   /* `signed' is the same as `int'.  FIXME: the declarations of "signed",
3638      "unsigned long", "long long unsigned" and "unsigned short" were in C++
3639      but not C.  Are the conditionals here needed?  */
3640   if (c_dialect_cxx ())
3641     record_builtin_type (RID_SIGNED, NULL, integer_type_node);
3642   record_builtin_type (RID_LONG, "long int", long_integer_type_node);
3643   record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
3644   record_builtin_type (RID_MAX, "long unsigned int",
3645                        long_unsigned_type_node);
3646   if (c_dialect_cxx ())
3647     record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
3648   record_builtin_type (RID_MAX, "long long int",
3649                        long_long_integer_type_node);
3650   record_builtin_type (RID_MAX, "long long unsigned int",
3651                        long_long_unsigned_type_node);
3652   if (c_dialect_cxx ())
3653     record_builtin_type (RID_MAX, "long long unsigned",
3654                          long_long_unsigned_type_node);
3655   record_builtin_type (RID_SHORT, "short int", short_integer_type_node);
3656   record_builtin_type (RID_MAX, "short unsigned int",
3657                        short_unsigned_type_node);
3658   if (c_dialect_cxx ())
3659     record_builtin_type (RID_MAX, "unsigned short",
3660                          short_unsigned_type_node);
3661
3662   /* Define both `signed char' and `unsigned char'.  */
3663   record_builtin_type (RID_MAX, "signed char", signed_char_type_node);
3664   record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node);
3665
3666   /* These are types that c_common_type_for_size and
3667      c_common_type_for_mode use.  */
3668   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3669                                          intQI_type_node));
3670   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3671                                          intHI_type_node));
3672   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3673                                          intSI_type_node));
3674   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3675                                          intDI_type_node));
3676 #if HOST_BITS_PER_WIDE_INT >= 64
3677   if (targetm.scalar_mode_supported_p (TImode))
3678     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3679                                            get_identifier ("__int128_t"),
3680                                            intTI_type_node));
3681 #endif
3682   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3683                                          unsigned_intQI_type_node));
3684   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3685                                          unsigned_intHI_type_node));
3686   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3687                                          unsigned_intSI_type_node));
3688   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3689                                          unsigned_intDI_type_node));
3690 #if HOST_BITS_PER_WIDE_INT >= 64
3691   if (targetm.scalar_mode_supported_p (TImode))
3692     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3693                                            get_identifier ("__uint128_t"),
3694                                            unsigned_intTI_type_node));
3695 #endif
3696
3697   /* Create the widest literal types.  */
3698   widest_integer_literal_type_node
3699     = make_signed_type (HOST_BITS_PER_WIDE_INT * 2);
3700   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3701                                          widest_integer_literal_type_node));
3702
3703   widest_unsigned_literal_type_node
3704     = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2);
3705   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3706                                          widest_unsigned_literal_type_node));
3707
3708   /* `unsigned long' is the standard type for sizeof.
3709      Note that stddef.h uses `unsigned long',
3710      and this must agree, even if long and int are the same size.  */
3711   size_type_node =
3712     TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE)));
3713   signed_size_type_node = c_common_signed_type (size_type_node);
3714   set_sizetype (size_type_node);
3715
3716   pid_type_node =
3717     TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE)));
3718
3719   build_common_tree_nodes_2 (flag_short_double);
3720
3721   record_builtin_type (RID_FLOAT, NULL, float_type_node);
3722   record_builtin_type (RID_DOUBLE, NULL, double_type_node);
3723   record_builtin_type (RID_MAX, "long double", long_double_type_node);
3724
3725   /* Only supported decimal floating point extension if the target
3726      actually supports underlying modes. */
3727   if (targetm.scalar_mode_supported_p (SDmode)
3728       && targetm.scalar_mode_supported_p (DDmode)
3729       && targetm.scalar_mode_supported_p (TDmode))
3730     {
3731       record_builtin_type (RID_DFLOAT32, NULL, dfloat32_type_node);
3732       record_builtin_type (RID_DFLOAT64, NULL, dfloat64_type_node);
3733       record_builtin_type (RID_DFLOAT128, NULL, dfloat128_type_node);
3734     }
3735
3736   if (targetm.fixed_point_supported_p ())
3737     {
3738       record_builtin_type (RID_MAX, "short _Fract", short_fract_type_node);
3739       record_builtin_type (RID_FRACT, NULL, fract_type_node);
3740       record_builtin_type (RID_MAX, "long _Fract", long_fract_type_node);
3741       record_builtin_type (RID_MAX, "long long _Fract",
3742                            long_long_fract_type_node);
3743       record_builtin_type (RID_MAX, "unsigned short _Fract",
3744                            unsigned_short_fract_type_node);
3745       record_builtin_type (RID_MAX, "unsigned _Fract",
3746                            unsigned_fract_type_node);
3747       record_builtin_type (RID_MAX, "unsigned long _Fract",
3748                            unsigned_long_fract_type_node);
3749       record_builtin_type (RID_MAX, "unsigned long long _Fract",
3750                            unsigned_long_long_fract_type_node);
3751       record_builtin_type (RID_MAX, "_Sat short _Fract",
3752                            sat_short_fract_type_node);
3753       record_builtin_type (RID_MAX, "_Sat _Fract", sat_fract_type_node);
3754       record_builtin_type (RID_MAX, "_Sat long _Fract",
3755                            sat_long_fract_type_node);
3756       record_builtin_type (RID_MAX, "_Sat long long _Fract",
3757                            sat_long_long_fract_type_node);
3758       record_builtin_type (RID_MAX, "_Sat unsigned short _Fract",
3759                            sat_unsigned_short_fract_type_node);
3760       record_builtin_type (RID_MAX, "_Sat unsigned _Fract",
3761                            sat_unsigned_fract_type_node);
3762       record_builtin_type (RID_MAX, "_Sat unsigned long _Fract",
3763                            sat_unsigned_long_fract_type_node);
3764       record_builtin_type (RID_MAX, "_Sat unsigned long long _Fract",
3765                            sat_unsigned_long_long_fract_type_node);
3766       record_builtin_type (RID_MAX, "short _Accum", short_accum_type_node);
3767       record_builtin_type (RID_ACCUM, NULL, accum_type_node);
3768       record_builtin_type (RID_MAX, "long _Accum", long_accum_type_node);
3769       record_builtin_type (RID_MAX, "long long _Accum",
3770                            long_long_accum_type_node);
3771       record_builtin_type (RID_MAX, "unsigned short _Accum",
3772                            unsigned_short_accum_type_node);
3773       record_builtin_type (RID_MAX, "unsigned _Accum",
3774                            unsigned_accum_type_node);
3775       record_builtin_type (RID_MAX, "unsigned long _Accum",
3776                            unsigned_long_accum_type_node);
3777       record_builtin_type (RID_MAX, "unsigned long long _Accum",
3778                            unsigned_long_long_accum_type_node);
3779       record_builtin_type (RID_MAX, "_Sat short _Accum",
3780                            sat_short_accum_type_node);
3781       record_builtin_type (RID_MAX, "_Sat _Accum", sat_accum_type_node);
3782       record_builtin_type (RID_MAX, "_Sat long _Accum",
3783                            sat_long_accum_type_node);
3784       record_builtin_type (RID_MAX, "_Sat long long _Accum",
3785                           sat_long_long_accum_type_node);
3786       record_builtin_type (RID_MAX, "_Sat unsigned short _Accum",
3787                            sat_unsigned_short_accum_type_node);
3788       record_builtin_type (RID_MAX, "_Sat unsigned _Accum",
3789                            sat_unsigned_accum_type_node);
3790       record_builtin_type (RID_MAX, "_Sat unsigned long _Accum",
3791                            sat_unsigned_long_accum_type_node);
3792       record_builtin_type (RID_MAX, "_Sat unsigned long long _Accum",
3793                            sat_unsigned_long_long_accum_type_node);
3794
3795     }
3796
3797   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3798                                          get_identifier ("complex int"),
3799                                          complex_integer_type_node));
3800   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3801                                          get_identifier ("complex float"),
3802                                          complex_float_type_node));
3803   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3804                                          get_identifier ("complex double"),
3805                                          complex_double_type_node));
3806   lang_hooks.decls.pushdecl
3807     (build_decl (TYPE_DECL, get_identifier ("complex long double"),
3808                  complex_long_double_type_node));
3809
3810   if (c_dialect_cxx ())
3811     /* For C++, make fileptr_type_node a distinct void * type until
3812        FILE type is defined.  */
3813     fileptr_type_node = build_variant_type_copy (ptr_type_node);
3814
3815   record_builtin_type (RID_VOID, NULL, void_type_node);
3816
3817   /* Set the TYPE_NAME for any variants that were built before
3818      record_builtin_type gave names to the built-in types. */
3819   {
3820     tree void_name = TYPE_NAME (void_type_node);
3821     TYPE_NAME (void_type_node) = NULL_TREE;
3822     TYPE_NAME (build_qualified_type (void_type_node, TYPE_QUAL_CONST))
3823       = void_name;
3824     TYPE_NAME (void_type_node) = void_name;
3825   }
3826
3827   /* This node must not be shared.  */
3828   void_zero_node = make_node (INTEGER_CST);
3829   TREE_TYPE (void_zero_node) = void_type_node;
3830
3831   void_list_node = build_void_list_node ();
3832
3833   /* Make a type to be the domain of a few array types
3834      whose domains don't really matter.
3835      200 is small enough that it always fits in size_t
3836      and large enough that it can hold most function names for the
3837      initializations of __FUNCTION__ and __PRETTY_FUNCTION__.  */
3838   array_domain_type = build_index_type (size_int (200));
3839
3840   /* Make a type for arrays of characters.
3841      With luck nothing will ever really depend on the length of this
3842      array type.  */
3843   char_array_type_node
3844     = build_array_type (char_type_node, array_domain_type);
3845
3846   /* Likewise for arrays of ints.  */
3847   int_array_type_node
3848     = build_array_type (integer_type_node, array_domain_type);
3849
3850   string_type_node = build_pointer_type (char_type_node);
3851   const_string_type_node
3852     = build_pointer_type (build_qualified_type
3853                           (char_type_node, TYPE_QUAL_CONST));
3854
3855   /* This is special for C++ so functions can be overloaded.  */
3856   wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE);
3857   wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node));
3858   wchar_type_size = TYPE_PRECISION (wchar_type_node);
3859   if (c_dialect_cxx ())
3860     {
3861       if (TYPE_UNSIGNED (wchar_type_node))
3862         wchar_type_node = make_unsigned_type (wchar_type_size);
3863       else
3864         wchar_type_node = make_signed_type (wchar_type_size);
3865       record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node);
3866     }
3867   else
3868     {
3869       signed_wchar_type_node = c_common_signed_type (wchar_type_node);
3870       unsigned_wchar_type_node = c_common_unsigned_type (wchar_type_node);
3871     }
3872
3873   /* This is for wide string constants.  */
3874   wchar_array_type_node
3875     = build_array_type (wchar_type_node, array_domain_type);
3876
3877   wint_type_node =
3878     TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE)));
3879
3880   intmax_type_node =
3881     TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE)));
3882   uintmax_type_node =
3883     TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE)));
3884
3885   default_function_type = build_function_type (integer_type_node, NULL_TREE);
3886   ptrdiff_type_node
3887     = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE)));
3888   unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node);
3889
3890   lang_hooks.decls.pushdecl
3891     (build_decl (TYPE_DECL, get_identifier ("__builtin_va_list"),
3892                  va_list_type_node));
3893
3894   if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
3895     {
3896       va_list_arg_type_node = va_list_ref_type_node =
3897         build_pointer_type (TREE_TYPE (va_list_type_node));
3898     }
3899   else
3900     {
3901       va_list_arg_type_node = va_list_type_node;
3902       va_list_ref_type_node = build_reference_type (va_list_type_node);
3903     }
3904
3905   if (!flag_preprocess_only)
3906     c_define_builtins (va_list_ref_type_node, va_list_arg_type_node);
3907
3908   main_identifier_node = get_identifier ("main");
3909
3910   /* Create the built-in __null node.  It is important that this is
3911      not shared.  */
3912   null_node = make_node (INTEGER_CST);
3913   TREE_TYPE (null_node) = c_common_type_for_size (POINTER_SIZE, 0);
3914
3915   /* Since builtin_types isn't gc'ed, don't export these nodes.  */
3916   memset (builtin_types, 0, sizeof (builtin_types));
3917 }
3918
3919 /* Look up the function in built_in_decls that corresponds to DECL
3920    and set ASMSPEC as its user assembler name.  DECL must be a
3921    function decl that declares a builtin.  */
3922
3923 void
3924 set_builtin_user_assembler_name (tree decl, const char *asmspec)
3925 {
3926   tree builtin;
3927   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
3928               && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
3929               && asmspec != 0);
3930
3931   builtin = built_in_decls [DECL_FUNCTION_CODE (decl)];
3932   set_user_assembler_name (builtin, asmspec);
3933   if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMCPY)
3934     init_block_move_fn (asmspec);
3935   else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMSET)
3936     init_block_clear_fn (asmspec);
3937 }
3938
3939 /* The number of named compound-literals generated thus far.  */
3940 static GTY(()) int compound_literal_number;
3941
3942 /* Set DECL_NAME for DECL, a VAR_DECL for a compound-literal.  */
3943
3944 void
3945 set_compound_literal_name (tree decl)
3946 {
3947   char *name;
3948   ASM_FORMAT_PRIVATE_NAME (name, "__compound_literal",
3949                            compound_literal_number);
3950   compound_literal_number++;
3951   DECL_NAME (decl) = get_identifier (name);
3952 }
3953
3954 tree
3955 build_va_arg (tree expr, tree type)
3956 {
3957   return build1 (VA_ARG_EXPR, type, expr);
3958 }
3959
3960
3961 /* Linked list of disabled built-in functions.  */
3962
3963 typedef struct disabled_builtin
3964 {
3965   const char *name;
3966   struct disabled_builtin *next;
3967 } disabled_builtin;
3968 static disabled_builtin *disabled_builtins = NULL;
3969
3970 static bool builtin_function_disabled_p (const char *);
3971
3972 /* Disable a built-in function specified by -fno-builtin-NAME.  If NAME
3973    begins with "__builtin_", give an error.  */
3974
3975 void
3976 disable_builtin_function (const char *name)
3977 {
3978   if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
3979     error ("cannot disable built-in function %qs", name);
3980   else
3981     {
3982       disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin);
3983       new_disabled_builtin->name = name;
3984       new_disabled_builtin->next = disabled_builtins;
3985       disabled_builtins = new_disabled_builtin;
3986     }
3987 }
3988
3989
3990 /* Return true if the built-in function NAME has been disabled, false
3991    otherwise.  */
3992
3993 static bool
3994 builtin_function_disabled_p (const char *name)
3995 {
3996   disabled_builtin *p;
3997   for (p = disabled_builtins; p != NULL; p = p->next)
3998     {
3999       if (strcmp (name, p->name) == 0)
4000         return true;
4001     }
4002   return false;
4003 }
4004
4005
4006 /* Worker for DEF_BUILTIN.
4007    Possibly define a builtin function with one or two names.
4008    Does not declare a non-__builtin_ function if flag_no_builtin, or if
4009    nonansi_p and flag_no_nonansi_builtin.  */
4010
4011 static void
4012 def_builtin_1 (enum built_in_function fncode,
4013                const char *name,
4014                enum built_in_class fnclass,
4015                tree fntype, tree libtype,
4016                bool both_p, bool fallback_p, bool nonansi_p,
4017                tree fnattrs, bool implicit_p)
4018 {
4019   tree decl;
4020   const char *libname;
4021
4022   if (fntype == error_mark_node)
4023     return;
4024
4025   gcc_assert ((!both_p && !fallback_p)
4026               || !strncmp (name, "__builtin_",
4027                            strlen ("__builtin_")));
4028
4029   libname = name + strlen ("__builtin_");
4030   decl = add_builtin_function (name, fntype, fncode, fnclass,
4031                                (fallback_p ? libname : NULL),
4032                                fnattrs);
4033   if (both_p
4034       && !flag_no_builtin && !builtin_function_disabled_p (libname)
4035       && !(nonansi_p && flag_no_nonansi_builtin))
4036     add_builtin_function (libname, libtype, fncode, fnclass,
4037                           NULL, fnattrs);
4038
4039   built_in_decls[(int) fncode] = decl;
4040   if (implicit_p)
4041     implicit_built_in_decls[(int) fncode] = decl;
4042 }
4043 \f
4044 /* Nonzero if the type T promotes to int.  This is (nearly) the
4045    integral promotions defined in ISO C99 6.3.1.1/2.  */
4046
4047 bool
4048 c_promoting_integer_type_p (const_tree t)
4049 {
4050   switch (TREE_CODE (t))
4051     {
4052     case INTEGER_TYPE:
4053       return (TYPE_MAIN_VARIANT (t) == char_type_node
4054               || TYPE_MAIN_VARIANT (t) == signed_char_type_node
4055               || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node
4056               || TYPE_MAIN_VARIANT (t) == short_integer_type_node
4057               || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node
4058               || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node));
4059
4060     case ENUMERAL_TYPE:
4061       /* ??? Technically all enumerations not larger than an int
4062          promote to an int.  But this is used along code paths
4063          that only want to notice a size change.  */
4064       return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node);
4065
4066     case BOOLEAN_TYPE:
4067       return 1;
4068
4069     default:
4070       return 0;
4071     }
4072 }
4073
4074 /* Return 1 if PARMS specifies a fixed number of parameters
4075    and none of their types is affected by default promotions.  */
4076
4077 int
4078 self_promoting_args_p (const_tree parms)
4079 {
4080   const_tree t;
4081   for (t = parms; t; t = TREE_CHAIN (t))
4082     {
4083       tree type = TREE_VALUE (t);
4084
4085       if (type == error_mark_node)
4086         continue;
4087
4088       if (TREE_CHAIN (t) == 0 && type != void_type_node)
4089         return 0;
4090
4091       if (type == 0)
4092         return 0;
4093
4094       if (TYPE_MAIN_VARIANT (type) == float_type_node)
4095         return 0;
4096
4097       if (c_promoting_integer_type_p (type))
4098         return 0;
4099     }
4100   return 1;
4101 }
4102
4103 /* Recursively examines the array elements of TYPE, until a non-array
4104    element type is found.  */
4105
4106 tree
4107 strip_array_types (tree type)
4108 {
4109   while (TREE_CODE (type) == ARRAY_TYPE)
4110     type = TREE_TYPE (type);
4111
4112   return type;
4113 }
4114
4115 /* Recursively remove any '*' or '&' operator from TYPE.  */
4116 tree
4117 strip_pointer_operator (tree t)
4118 {
4119   while (POINTER_TYPE_P (t))
4120     t = TREE_TYPE (t);
4121   return t;
4122 }
4123
4124 /* Recursively remove pointer or array type from TYPE. */
4125 tree
4126 strip_pointer_or_array_types (tree t)
4127 {
4128   while (TREE_CODE (t) == ARRAY_TYPE || POINTER_TYPE_P (t))
4129     t = TREE_TYPE (t);
4130   return t;
4131 }
4132
4133 /* Used to compare case labels.  K1 and K2 are actually tree nodes
4134    representing case labels, or NULL_TREE for a `default' label.
4135    Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
4136    K2, and 0 if K1 and K2 are equal.  */
4137
4138 int
4139 case_compare (splay_tree_key k1, splay_tree_key k2)
4140 {
4141   /* Consider a NULL key (such as arises with a `default' label) to be
4142      smaller than anything else.  */
4143   if (!k1)
4144     return k2 ? -1 : 0;
4145   else if (!k2)
4146     return k1 ? 1 : 0;
4147
4148   return tree_int_cst_compare ((tree) k1, (tree) k2);
4149 }
4150
4151 /* Process a case label for the range LOW_VALUE ... HIGH_VALUE.  If
4152    LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is
4153    actually a `default' label.  If only HIGH_VALUE is NULL_TREE, then
4154    case label was declared using the usual C/C++ syntax, rather than
4155    the GNU case range extension.  CASES is a tree containing all the
4156    case ranges processed so far; COND is the condition for the
4157    switch-statement itself.  Returns the CASE_LABEL_EXPR created, or
4158    ERROR_MARK_NODE if no CASE_LABEL_EXPR is created.  */
4159
4160 tree
4161 c_add_case_label (splay_tree cases, tree cond, tree orig_type,
4162                   tree low_value, tree high_value)
4163 {
4164   tree type;
4165   tree label;
4166   tree case_label;
4167   splay_tree_node node;
4168
4169   /* Create the LABEL_DECL itself.  */
4170   label = create_artificial_label ();
4171
4172   /* If there was an error processing the switch condition, bail now
4173      before we get more confused.  */
4174   if (!cond || cond == error_mark_node)
4175     goto error_out;
4176
4177   if ((low_value && TREE_TYPE (low_value)
4178        && POINTER_TYPE_P (TREE_TYPE (low_value)))
4179       || (high_value && TREE_TYPE (high_value)
4180           && POINTER_TYPE_P (TREE_TYPE (high_value))))
4181     {
4182       error ("pointers are not permitted as case values");
4183       goto error_out;
4184     }
4185
4186   /* Case ranges are a GNU extension.  */
4187   if (high_value && pedantic)
4188     pedwarn ("range expressions in switch statements are non-standard");
4189
4190   type = TREE_TYPE (cond);
4191   if (low_value)
4192     {
4193       low_value = check_case_value (low_value);
4194       low_value = convert_and_check (type, low_value);
4195       if (low_value == error_mark_node)
4196         goto error_out;
4197     }
4198   if (high_value)
4199     {
4200       high_value = check_case_value (high_value);
4201       high_value = convert_and_check (type, high_value);
4202       if (high_value == error_mark_node)
4203         goto error_out;
4204     }
4205
4206   if (low_value && high_value)
4207     {
4208       /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
4209          really a case range, even though it was written that way.
4210          Remove the HIGH_VALUE to simplify later processing.  */
4211       if (tree_int_cst_equal (low_value, high_value))
4212         high_value = NULL_TREE;
4213       else if (!tree_int_cst_lt (low_value, high_value))
4214         warning (0, "empty range specified");
4215     }
4216
4217   /* See if the case is in range of the type of the original testing
4218      expression.  If both low_value and high_value are out of range,
4219      don't insert the case label and return NULL_TREE.  */
4220   if (low_value
4221       && !check_case_bounds (type, orig_type,
4222                              &low_value, high_value ? &high_value : NULL))
4223     return NULL_TREE;
4224
4225   /* Look up the LOW_VALUE in the table of case labels we already
4226      have.  */
4227   node = splay_tree_lookup (cases, (splay_tree_key) low_value);
4228   /* If there was not an exact match, check for overlapping ranges.
4229      There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
4230      that's a `default' label and the only overlap is an exact match.  */
4231   if (!node && (low_value || high_value))
4232     {
4233       splay_tree_node low_bound;
4234       splay_tree_node high_bound;
4235
4236       /* Even though there wasn't an exact match, there might be an
4237          overlap between this case range and another case range.
4238          Since we've (inductively) not allowed any overlapping case
4239          ranges, we simply need to find the greatest low case label
4240          that is smaller that LOW_VALUE, and the smallest low case
4241          label that is greater than LOW_VALUE.  If there is an overlap
4242          it will occur in one of these two ranges.  */
4243       low_bound = splay_tree_predecessor (cases,
4244                                           (splay_tree_key) low_value);
4245       high_bound = splay_tree_successor (cases,
4246                                          (splay_tree_key) low_value);
4247
4248       /* Check to see if the LOW_BOUND overlaps.  It is smaller than
4249          the LOW_VALUE, so there is no need to check unless the
4250          LOW_BOUND is in fact itself a case range.  */
4251       if (low_bound
4252           && CASE_HIGH ((tree) low_bound->value)
4253           && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
4254                                     low_value) >= 0)
4255         node = low_bound;
4256       /* Check to see if the HIGH_BOUND overlaps.  The low end of that
4257          range is bigger than the low end of the current range, so we
4258          are only interested if the current range is a real range, and
4259          not an ordinary case label.  */
4260       else if (high_bound
4261                && high_value
4262                && (tree_int_cst_compare ((tree) high_bound->key,
4263                                          high_value)
4264                    <= 0))
4265         node = high_bound;
4266     }
4267   /* If there was an overlap, issue an error.  */
4268   if (node)
4269     {
4270       tree duplicate = CASE_LABEL ((tree) node->value);
4271
4272       if (high_value)
4273         {
4274           error ("duplicate (or overlapping) case value");
4275           error ("%Jthis is the first entry overlapping that value", duplicate);
4276         }
4277       else if (low_value)
4278         {
4279           error ("duplicate case value") ;
4280           error ("%Jpreviously used here", duplicate);
4281         }
4282       else
4283         {
4284           error ("multiple default labels in one switch");
4285           error ("%Jthis is the first default label", duplicate);
4286         }
4287       goto error_out;
4288     }
4289
4290   /* Add a CASE_LABEL to the statement-tree.  */
4291   case_label = add_stmt (build_case_label (low_value, high_value, label));
4292   /* Register this case label in the splay tree.  */
4293   splay_tree_insert (cases,
4294                      (splay_tree_key) low_value,
4295                      (splay_tree_value) case_label);
4296
4297   return case_label;
4298
4299  error_out:
4300   /* Add a label so that the back-end doesn't think that the beginning of
4301      the switch is unreachable.  Note that we do not add a case label, as
4302      that just leads to duplicates and thence to failure later on.  */
4303   if (!cases->root)
4304     {
4305       tree t = create_artificial_label ();
4306       add_stmt (build_stmt (LABEL_EXPR, t));
4307     }
4308   return error_mark_node;
4309 }
4310
4311 /* Subroutines of c_do_switch_warnings, called via splay_tree_foreach.
4312    Used to verify that case values match up with enumerator values.  */
4313
4314 static void
4315 match_case_to_enum_1 (tree key, tree type, tree label)
4316 {
4317   char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1];
4318
4319   /* ??? Not working too hard to print the double-word value.
4320      Should perhaps be done with %lwd in the diagnostic routines?  */
4321   if (TREE_INT_CST_HIGH (key) == 0)
4322     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED,
4323               TREE_INT_CST_LOW (key));
4324   else if (!TYPE_UNSIGNED (type)
4325            && TREE_INT_CST_HIGH (key) == -1
4326            && TREE_INT_CST_LOW (key) != 0)
4327     snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED,
4328               -TREE_INT_CST_LOW (key));
4329   else
4330     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX,
4331               TREE_INT_CST_HIGH (key), TREE_INT_CST_LOW (key));
4332
4333   if (TYPE_NAME (type) == 0)
4334     warning (warn_switch ? OPT_Wswitch : OPT_Wswitch_enum,
4335              "%Jcase value %qs not in enumerated type",
4336              CASE_LABEL (label), buf);
4337   else
4338     warning (warn_switch ? OPT_Wswitch : OPT_Wswitch_enum,
4339              "%Jcase value %qs not in enumerated type %qT",
4340              CASE_LABEL (label), buf, type);
4341 }
4342
4343 /* Subroutine of c_do_switch_warnings, called via splay_tree_foreach.
4344    Used to verify that case values match up with enumerator values.  */
4345
4346 static int
4347 match_case_to_enum (splay_tree_node node, void *data)
4348 {
4349   tree label = (tree) node->value;
4350   tree type = (tree) data;
4351
4352   /* Skip default case.  */
4353   if (!CASE_LOW (label))
4354     return 0;
4355
4356   /* If CASE_LOW_SEEN is not set, that means CASE_LOW did not appear
4357      when we did our enum->case scan.  Reset our scratch bit after.  */
4358   if (!CASE_LOW_SEEN (label))
4359     match_case_to_enum_1 (CASE_LOW (label), type, label);
4360   else
4361     CASE_LOW_SEEN (label) = 0;
4362
4363   /* If CASE_HIGH is non-null, we have a range.  If CASE_HIGH_SEEN is
4364      not set, that means that CASE_HIGH did not appear when we did our
4365      enum->case scan.  Reset our scratch bit after.  */
4366   if (CASE_HIGH (label))
4367     {
4368       if (!CASE_HIGH_SEEN (label))
4369         match_case_to_enum_1 (CASE_HIGH (label), type, label);
4370       else
4371         CASE_HIGH_SEEN (label) = 0;
4372     }
4373
4374   return 0;
4375 }
4376
4377 /* Handle -Wswitch*.  Called from the front end after parsing the
4378    switch construct.  */
4379 /* ??? Should probably be somewhere generic, since other languages
4380    besides C and C++ would want this.  At the moment, however, C/C++
4381    are the only tree-ssa languages that support enumerations at all,
4382    so the point is moot.  */
4383
4384 void
4385 c_do_switch_warnings (splay_tree cases, location_t switch_location,
4386                       tree type, tree cond)
4387 {
4388   splay_tree_node default_node;
4389   splay_tree_node node;
4390   tree chain;
4391   int saved_warn_switch;
4392
4393   if (!warn_switch && !warn_switch_enum && !warn_switch_default)
4394     return;
4395
4396   default_node = splay_tree_lookup (cases, (splay_tree_key) NULL);
4397   if (!default_node)
4398     warning (OPT_Wswitch_default, "%Hswitch missing default case",
4399              &switch_location);
4400
4401   /* From here on, we only care about about enumerated types.  */
4402   if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
4403     return;
4404
4405   /* If the switch expression was an enumerated type, check that
4406      exactly all enumeration literals are covered by the cases.
4407      The check is made when -Wswitch was specified and there is no
4408      default case, or when -Wswitch-enum was specified.  */
4409
4410   if (!warn_switch_enum
4411       && !(warn_switch && !default_node))
4412     return;
4413
4414   /* Clearing COND if it is not an integer constant simplifies
4415      the tests inside the loop below.  */
4416   if (TREE_CODE (cond) != INTEGER_CST)
4417     cond = NULL_TREE;
4418
4419   /* The time complexity here is O(N*lg(N)) worst case, but for the
4420       common case of monotonically increasing enumerators, it is
4421       O(N), since the nature of the splay tree will keep the next
4422       element adjacent to the root at all times.  */
4423
4424   for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain))
4425     {
4426       tree value = TREE_VALUE (chain);
4427       node = splay_tree_lookup (cases, (splay_tree_key) value);
4428       if (node)
4429         {
4430           /* Mark the CASE_LOW part of the case entry as seen.  */
4431           tree label = (tree) node->value;
4432           CASE_LOW_SEEN (label) = 1;
4433           continue;
4434         }
4435
4436       /* Even though there wasn't an exact match, there might be a
4437          case range which includes the enumator's value.  */
4438       node = splay_tree_predecessor (cases, (splay_tree_key) value);
4439       if (node && CASE_HIGH ((tree) node->value))
4440         {
4441           tree label = (tree) node->value;
4442           int cmp = tree_int_cst_compare (CASE_HIGH (label), value);
4443           if (cmp >= 0)
4444             {
4445               /* If we match the upper bound exactly, mark the CASE_HIGH
4446                  part of the case entry as seen.  */
4447               if (cmp == 0)
4448                 CASE_HIGH_SEEN (label) = 1;
4449               continue;
4450             }
4451         }
4452
4453       /* We've now determined that this enumerated literal isn't
4454          handled by the case labels of the switch statement.  */
4455
4456       /* If the switch expression is a constant, we only really care
4457          about whether that constant is handled by the switch.  */
4458       if (cond && tree_int_cst_compare (cond, value))
4459         continue;
4460
4461       /* If there is a default_node, the only relevant option is
4462          Wswitch-enum. Otherwise, if both are enabled then we prefer
4463          to warn using -Wswitch because -Wswitch is enabled by -Wall
4464          while -Wswitch-enum is explicit.  */
4465       warning ((default_node || !warn_switch)
4466                ? OPT_Wswitch_enum : OPT_Wswitch,
4467                "%Henumeration value %qE not handled in switch",
4468                &switch_location, TREE_PURPOSE (chain));
4469     }
4470
4471   /* Warn if there are case expressions that don't correspond to
4472      enumerators.  This can occur since C and C++ don't enforce
4473      type-checking of assignments to enumeration variables.
4474
4475      The time complexity here is now always O(N) worst case, since
4476      we should have marked both the lower bound and upper bound of
4477      every disjoint case label, with CASE_LOW_SEEN and CASE_HIGH_SEEN
4478      above.  This scan also resets those fields.  */
4479
4480   /* If there is a default_node, the only relevant option is
4481      Wswitch-enum. Otherwise, if both are enabled then we prefer
4482      to warn using -Wswitch because -Wswitch is enabled by -Wall
4483      while -Wswitch-enum is explicit.  */
4484   saved_warn_switch = warn_switch;
4485   if (default_node)
4486     warn_switch = 0;
4487   splay_tree_foreach (cases, match_case_to_enum, type);
4488   warn_switch = saved_warn_switch;
4489
4490 }
4491
4492 /* Finish an expression taking the address of LABEL (an
4493    IDENTIFIER_NODE).  Returns an expression for the address.  */
4494
4495 tree
4496 finish_label_address_expr (tree label)
4497 {
4498   tree result;
4499
4500   if (pedantic)
4501     pedwarn ("taking the address of a label is non-standard");
4502
4503   if (label == error_mark_node)
4504     return error_mark_node;
4505
4506   label = lookup_label (label);
4507   if (label == NULL_TREE)
4508     result = null_pointer_node;
4509   else
4510     {
4511       TREE_USED (label) = 1;
4512       result = build1 (ADDR_EXPR, ptr_type_node, label);
4513       /* The current function in not necessarily uninlinable.
4514          Computed gotos are incompatible with inlining, but the value
4515          here could be used only in a diagnostic, for example.  */
4516     }
4517
4518   return result;
4519 }
4520
4521 /* Hook used by expand_expr to expand language-specific tree codes.  */
4522 /* The only things that should go here are bits needed to expand
4523    constant initializers.  Everything else should be handled by the
4524    gimplification routines.  */
4525
4526 rtx
4527 c_expand_expr (tree exp, rtx target, enum machine_mode tmode,
4528                int modifier /* Actually enum_modifier.  */,
4529                rtx *alt_rtl)
4530 {
4531   switch (TREE_CODE (exp))
4532     {
4533     case COMPOUND_LITERAL_EXPR:
4534       {
4535         /* Initialize the anonymous variable declared in the compound
4536            literal, then return the variable.  */
4537         tree decl = COMPOUND_LITERAL_EXPR_DECL (exp);
4538         emit_local_var (decl);
4539         return expand_expr_real (decl, target, tmode, modifier, alt_rtl);
4540       }
4541
4542     default:
4543       gcc_unreachable ();
4544     }
4545 }
4546
4547 /* Hook used by staticp to handle language-specific tree codes.  */
4548
4549 tree
4550 c_staticp (tree exp)
4551 {
4552   return (TREE_CODE (exp) == COMPOUND_LITERAL_EXPR
4553           && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp))
4554           ? exp : NULL);
4555 }
4556 \f
4557
4558 /* Given a boolean expression ARG, return a tree representing an increment
4559    or decrement (as indicated by CODE) of ARG.  The front end must check for
4560    invalid cases (e.g., decrement in C++).  */
4561 tree
4562 boolean_increment (enum tree_code code, tree arg)
4563 {
4564   tree val;
4565   tree true_res = build_int_cst (TREE_TYPE (arg), 1);
4566
4567   arg = stabilize_reference (arg);
4568   switch (code)
4569     {
4570     case PREINCREMENT_EXPR:
4571       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
4572       break;
4573     case POSTINCREMENT_EXPR:
4574       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
4575       arg = save_expr (arg);
4576       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
4577       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
4578       break;
4579     case PREDECREMENT_EXPR:
4580       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
4581                     invert_truthvalue (arg));
4582       break;
4583     case POSTDECREMENT_EXPR:
4584       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
4585                     invert_truthvalue (arg));
4586       arg = save_expr (arg);
4587       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
4588       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
4589       break;
4590     default:
4591       gcc_unreachable ();
4592     }
4593   TREE_SIDE_EFFECTS (val) = 1;
4594   return val;
4595 }
4596 \f
4597 /* Built-in macros for stddef.h, that require macros defined in this
4598    file.  */
4599 void
4600 c_stddef_cpp_builtins(void)
4601 {
4602   builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0);
4603   builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0);
4604   builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0);
4605   builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0);
4606   builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0);
4607   builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0);
4608 }
4609
4610 static void
4611 c_init_attributes (void)
4612 {
4613   /* Fill in the built_in_attributes array.  */
4614 #define DEF_ATTR_NULL_TREE(ENUM)                                \
4615   built_in_attributes[(int) ENUM] = NULL_TREE;
4616 #define DEF_ATTR_INT(ENUM, VALUE)                               \
4617   built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
4618 #define DEF_ATTR_IDENT(ENUM, STRING)                            \
4619   built_in_attributes[(int) ENUM] = get_identifier (STRING);
4620 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
4621   built_in_attributes[(int) ENUM]                       \
4622     = tree_cons (built_in_attributes[(int) PURPOSE],    \
4623                  built_in_attributes[(int) VALUE],      \
4624                  built_in_attributes[(int) CHAIN]);
4625 #include "builtin-attrs.def"
4626 #undef DEF_ATTR_NULL_TREE
4627 #undef DEF_ATTR_INT
4628 #undef DEF_ATTR_IDENT
4629 #undef DEF_ATTR_TREE_LIST
4630 }
4631
4632 /* Attribute handlers common to C front ends.  */
4633
4634 /* Handle a "packed" attribute; arguments as in
4635    struct attribute_spec.handler.  */
4636
4637 static tree
4638 handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4639                          int flags, bool *no_add_attrs)
4640 {
4641   if (TYPE_P (*node))
4642     {
4643       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4644         *node = build_variant_type_copy (*node);
4645       TYPE_PACKED (*node) = 1;
4646     }
4647   else if (TREE_CODE (*node) == FIELD_DECL)
4648     {
4649       if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT)
4650         warning (OPT_Wattributes,
4651                  "%qE attribute ignored for field of type %qT",
4652                  name, TREE_TYPE (*node));
4653       else
4654         DECL_PACKED (*node) = 1;
4655     }
4656   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
4657      used for DECL_REGISTER.  It wouldn't mean anything anyway.
4658      We can't set DECL_PACKED on the type of a TYPE_DECL, because
4659      that changes what the typedef is typing.  */
4660   else
4661     {
4662       warning (OPT_Wattributes, "%qE attribute ignored", name);
4663       *no_add_attrs = true;
4664     }
4665
4666   return NULL_TREE;
4667 }
4668
4669 /* Handle a "nocommon" attribute; arguments as in
4670    struct attribute_spec.handler.  */
4671
4672 static tree
4673 handle_nocommon_attribute (tree *node, tree name,
4674                            tree ARG_UNUSED (args),
4675                            int ARG_UNUSED (flags), bool *no_add_attrs)
4676 {
4677   if (TREE_CODE (*node) == VAR_DECL)
4678     DECL_COMMON (*node) = 0;
4679   else
4680     {
4681       warning (OPT_Wattributes, "%qE attribute ignored", name);
4682       *no_add_attrs = true;
4683     }
4684
4685   return NULL_TREE;
4686 }
4687
4688 /* Handle a "common" attribute; arguments as in
4689    struct attribute_spec.handler.  */
4690
4691 static tree
4692 handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4693                          int ARG_UNUSED (flags), bool *no_add_attrs)
4694 {
4695   if (TREE_CODE (*node) == VAR_DECL)
4696     DECL_COMMON (*node) = 1;
4697   else
4698     {
4699       warning (OPT_Wattributes, "%qE attribute ignored", name);
4700       *no_add_attrs = true;
4701     }
4702
4703   return NULL_TREE;
4704 }
4705
4706 /* Handle a "noreturn" attribute; arguments as in
4707    struct attribute_spec.handler.  */
4708
4709 static tree
4710 handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4711                            int ARG_UNUSED (flags), bool *no_add_attrs)
4712 {
4713   tree type = TREE_TYPE (*node);
4714
4715   /* See FIXME comment in c_common_attribute_table.  */
4716   if (TREE_CODE (*node) == FUNCTION_DECL)
4717     TREE_THIS_VOLATILE (*node) = 1;
4718   else if (TREE_CODE (type) == POINTER_TYPE
4719            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4720     TREE_TYPE (*node)
4721       = build_pointer_type
4722         (build_type_variant (TREE_TYPE (type),
4723                              TYPE_READONLY (TREE_TYPE (type)), 1));
4724   else
4725     {
4726       warning (OPT_Wattributes, "%qE attribute ignored", name);
4727       *no_add_attrs = true;
4728     }
4729
4730   return NULL_TREE;
4731 }
4732
4733 /* Handle a "hot" and attribute; arguments as in
4734    struct attribute_spec.handler.  */
4735
4736 static tree
4737 handle_hot_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4738                           int ARG_UNUSED (flags), bool *no_add_attrs)
4739 {
4740   if (TREE_CODE (*node) == FUNCTION_DECL)
4741     {
4742       if (lookup_attribute ("cold", DECL_ATTRIBUTES (*node)) != NULL)
4743         {
4744           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
4745                    name, "cold");
4746           *no_add_attrs = true;
4747         }
4748       /* Do nothing else, just set the attribute.  We'll get at
4749          it later with lookup_attribute.  */
4750     }
4751   else
4752     {
4753       warning (OPT_Wattributes, "%qE attribute ignored", name);
4754       *no_add_attrs = true;
4755     }
4756
4757   return NULL_TREE;
4758 }
4759 /* Handle a "cold" and attribute; arguments as in
4760    struct attribute_spec.handler.  */
4761
4762 static tree
4763 handle_cold_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4764                        int ARG_UNUSED (flags), bool *no_add_attrs)
4765 {
4766   if (TREE_CODE (*node) == FUNCTION_DECL)
4767     {
4768       if (lookup_attribute ("hot", DECL_ATTRIBUTES (*node)) != NULL)
4769         {
4770           warning (OPT_Wattributes, "%qE attribute conflicts with attribute %s",
4771                    name, "hot");
4772           *no_add_attrs = true;
4773         }
4774       /* Do nothing else, just set the attribute.  We'll get at
4775          it later with lookup_attribute.  */
4776     }
4777   else
4778     {
4779       warning (OPT_Wattributes, "%qE attribute ignored", name);
4780       *no_add_attrs = true;
4781     }
4782
4783   return NULL_TREE;
4784 }
4785
4786 /* Handle a "noinline" attribute; arguments as in
4787    struct attribute_spec.handler.  */
4788
4789 static tree
4790 handle_noinline_attribute (tree *node, tree name,
4791                            tree ARG_UNUSED (args),
4792                            int ARG_UNUSED (flags), bool *no_add_attrs)
4793 {
4794   if (TREE_CODE (*node) == FUNCTION_DECL)
4795     DECL_UNINLINABLE (*node) = 1;
4796   else
4797     {
4798       warning (OPT_Wattributes, "%qE attribute ignored", name);
4799       *no_add_attrs = true;
4800     }
4801
4802   return NULL_TREE;
4803 }
4804
4805 /* Handle a "always_inline" attribute; arguments as in
4806    struct attribute_spec.handler.  */
4807
4808 static tree
4809 handle_always_inline_attribute (tree *node, tree name,
4810                                 tree ARG_UNUSED (args),
4811                                 int ARG_UNUSED (flags),
4812                                 bool *no_add_attrs)
4813 {
4814   if (TREE_CODE (*node) == FUNCTION_DECL)
4815     {
4816       /* Set the attribute and mark it for disregarding inline
4817          limits.  */
4818       DECL_DISREGARD_INLINE_LIMITS (*node) = 1;
4819     }
4820   else
4821     {
4822       warning (OPT_Wattributes, "%qE attribute ignored", name);
4823       *no_add_attrs = true;
4824     }
4825
4826   return NULL_TREE;
4827 }
4828
4829 /* Handle a "gnu_inline" attribute; arguments as in
4830    struct attribute_spec.handler.  */
4831
4832 static tree
4833 handle_gnu_inline_attribute (tree *node, tree name,
4834                              tree ARG_UNUSED (args),
4835                              int ARG_UNUSED (flags),
4836                              bool *no_add_attrs)
4837 {
4838   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
4839     {
4840       /* Do nothing else, just set the attribute.  We'll get at
4841          it later with lookup_attribute.  */
4842     }
4843   else
4844     {
4845       warning (OPT_Wattributes, "%qE attribute ignored", name);
4846       *no_add_attrs = true;
4847     }
4848
4849   return NULL_TREE;
4850 }
4851
4852 /* Handle an "artificial" attribute; arguments as in
4853    struct attribute_spec.handler.  */
4854
4855 static tree
4856 handle_artificial_attribute (tree *node, tree name,
4857                              tree ARG_UNUSED (args),
4858                              int ARG_UNUSED (flags),
4859                              bool *no_add_attrs)
4860 {
4861   if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node))
4862     {
4863       /* Do nothing else, just set the attribute.  We'll get at
4864          it later with lookup_attribute.  */
4865     }
4866   else
4867     {
4868       warning (OPT_Wattributes, "%qE attribute ignored", name);
4869       *no_add_attrs = true;
4870     }
4871
4872   return NULL_TREE;
4873 }
4874
4875 /* Handle a "flatten" attribute; arguments as in
4876    struct attribute_spec.handler.  */
4877
4878 static tree
4879 handle_flatten_attribute (tree *node, tree name,
4880                           tree args ATTRIBUTE_UNUSED,
4881                           int flags ATTRIBUTE_UNUSED, bool *no_add_attrs)
4882 {
4883   if (TREE_CODE (*node) == FUNCTION_DECL)
4884     /* Do nothing else, just set the attribute.  We'll get at
4885        it later with lookup_attribute.  */
4886     ;
4887   else
4888     {
4889       warning (OPT_Wattributes, "%qE attribute ignored", name);
4890       *no_add_attrs = true;
4891     }
4892
4893   return NULL_TREE;
4894 }
4895
4896 /* Handle a "warning" or "error" attribute; arguments as in
4897    struct attribute_spec.handler.  */
4898
4899 static tree
4900 handle_error_attribute (tree *node, tree name, tree args,
4901                         int ARG_UNUSED (flags), bool *no_add_attrs)
4902 {
4903   if (TREE_CODE (*node) == FUNCTION_DECL
4904       || TREE_CODE (TREE_VALUE (args)) == STRING_CST)
4905     /* Do nothing else, just set the attribute.  We'll get at
4906        it later with lookup_attribute.  */
4907     ;
4908   else
4909     {
4910       warning (OPT_Wattributes, "%qE attribute ignored", name);
4911       *no_add_attrs = true;
4912     }
4913
4914   return NULL_TREE;
4915 }
4916
4917 /* Handle a "used" attribute; arguments as in
4918    struct attribute_spec.handler.  */
4919
4920 static tree
4921 handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
4922                        int ARG_UNUSED (flags), bool *no_add_attrs)
4923 {
4924   tree node = *pnode;
4925
4926   if (TREE_CODE (node) == FUNCTION_DECL
4927       || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node)))
4928     {
4929       TREE_USED (node) = 1;
4930       DECL_PRESERVE_P (node) = 1;
4931     }
4932   else
4933     {
4934       warning (OPT_Wattributes, "%qE attribute ignored", name);
4935       *no_add_attrs = true;
4936     }
4937
4938   return NULL_TREE;
4939 }
4940
4941 /* Handle a "unused" attribute; arguments as in
4942    struct attribute_spec.handler.  */
4943
4944 static tree
4945 handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4946                          int flags, bool *no_add_attrs)
4947 {
4948   if (DECL_P (*node))
4949     {
4950       tree decl = *node;
4951
4952       if (TREE_CODE (decl) == PARM_DECL
4953           || TREE_CODE (decl) == VAR_DECL
4954           || TREE_CODE (decl) == FUNCTION_DECL
4955           || TREE_CODE (decl) == LABEL_DECL
4956           || TREE_CODE (decl) == TYPE_DECL)
4957         TREE_USED (decl) = 1;
4958       else
4959         {
4960           warning (OPT_Wattributes, "%qE attribute ignored", name);
4961           *no_add_attrs = true;
4962         }
4963     }
4964   else
4965     {
4966       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4967         *node = build_variant_type_copy (*node);
4968       TREE_USED (*node) = 1;
4969     }
4970
4971   return NULL_TREE;
4972 }
4973
4974 /* Handle a "externally_visible" attribute; arguments as in
4975    struct attribute_spec.handler.  */
4976
4977 static tree
4978 handle_externally_visible_attribute (tree *pnode, tree name,
4979                                      tree ARG_UNUSED (args),
4980                                      int ARG_UNUSED (flags),
4981                                      bool *no_add_attrs)
4982 {
4983   tree node = *pnode;
4984
4985   if (TREE_CODE (node) == FUNCTION_DECL || TREE_CODE (node) == VAR_DECL)
4986     {
4987       if ((!TREE_STATIC (node) && TREE_CODE (node) != FUNCTION_DECL
4988            && !DECL_EXTERNAL (node)) || !TREE_PUBLIC (node))
4989         {
4990           warning (OPT_Wattributes,
4991                    "%qE attribute have effect only on public objects", name);
4992           *no_add_attrs = true;
4993         }
4994     }
4995   else
4996     {
4997       warning (OPT_Wattributes, "%qE attribute ignored", name);
4998       *no_add_attrs = true;
4999     }
5000
5001   return NULL_TREE;
5002 }
5003
5004 /* Handle a "const" attribute; arguments as in
5005    struct attribute_spec.handler.  */
5006
5007 static tree
5008 handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5009                         int ARG_UNUSED (flags), bool *no_add_attrs)
5010 {
5011   tree type = TREE_TYPE (*node);
5012
5013   /* See FIXME comment on noreturn in c_common_attribute_table.  */
5014   if (TREE_CODE (*node) == FUNCTION_DECL)
5015     TREE_READONLY (*node) = 1;
5016   else if (TREE_CODE (type) == POINTER_TYPE
5017            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
5018     TREE_TYPE (*node)
5019       = build_pointer_type
5020         (build_type_variant (TREE_TYPE (type), 1,
5021                              TREE_THIS_VOLATILE (TREE_TYPE (type))));
5022   else
5023     {
5024       warning (OPT_Wattributes, "%qE attribute ignored", name);
5025       *no_add_attrs = true;
5026     }
5027
5028   return NULL_TREE;
5029 }
5030
5031 /* Handle a "transparent_union" attribute; arguments as in
5032    struct attribute_spec.handler.  */
5033
5034 static tree
5035 handle_transparent_union_attribute (tree *node, tree name,
5036                                     tree ARG_UNUSED (args), int flags,
5037                                     bool *no_add_attrs)
5038 {
5039   tree type;
5040
5041   *no_add_attrs = true;
5042
5043   if (TREE_CODE (*node) == TYPE_DECL)
5044     node = &TREE_TYPE (*node);
5045   type = *node;
5046
5047   if (TREE_CODE (type) == UNION_TYPE)
5048     {
5049       /* When IN_PLACE is set, leave the check for FIELDS and MODE to
5050          the code in finish_struct.  */
5051       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5052         {
5053           if (TYPE_FIELDS (type) == NULL_TREE
5054               || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type)))
5055             goto ignored;
5056
5057           /* A type variant isn't good enough, since we don't a cast
5058              to such a type removed as a no-op.  */
5059           *node = type = build_duplicate_type (type);
5060         }
5061
5062       TYPE_TRANSPARENT_UNION (type) = 1;
5063       return NULL_TREE;
5064     }
5065
5066  ignored:
5067   warning (OPT_Wattributes, "%qE attribute ignored", name);
5068   return NULL_TREE;
5069 }
5070
5071 /* Subroutine of handle_{con,de}structor_attribute.  Evaluate ARGS to
5072    get the requested priority for a constructor or destructor,
5073    possibly issuing diagnostics for invalid or reserved
5074    priorities.  */
5075
5076 static priority_type
5077 get_priority (tree args, bool is_destructor)
5078 {
5079   HOST_WIDE_INT pri;
5080   tree arg;
5081
5082   if (!args)
5083     return DEFAULT_INIT_PRIORITY;
5084
5085   if (!SUPPORTS_INIT_PRIORITY)
5086     {
5087       if (is_destructor)
5088         error ("destructor priorities are not supported");
5089       else
5090         error ("constructor priorities are not supported");
5091       return DEFAULT_INIT_PRIORITY;
5092     }
5093
5094   arg = TREE_VALUE (args);
5095   if (!host_integerp (arg, /*pos=*/0)
5096       || !INTEGRAL_TYPE_P (TREE_TYPE (arg)))
5097     goto invalid;
5098
5099   pri = tree_low_cst (TREE_VALUE (args), /*pos=*/0);
5100   if (pri < 0 || pri > MAX_INIT_PRIORITY)
5101     goto invalid;
5102
5103   if (pri <= MAX_RESERVED_INIT_PRIORITY)
5104     {
5105       if (is_destructor)
5106         warning (0,
5107                  "destructor priorities from 0 to %d are reserved "
5108                  "for the implementation",
5109                  MAX_RESERVED_INIT_PRIORITY);
5110       else
5111         warning (0,
5112                  "constructor priorities from 0 to %d are reserved "
5113                  "for the implementation",
5114                  MAX_RESERVED_INIT_PRIORITY);
5115     }
5116   return pri;
5117
5118  invalid:
5119   if (is_destructor)
5120     error ("destructor priorities must be integers from 0 to %d inclusive",
5121            MAX_INIT_PRIORITY);
5122   else
5123     error ("constructor priorities must be integers from 0 to %d inclusive",
5124            MAX_INIT_PRIORITY);
5125   return DEFAULT_INIT_PRIORITY;
5126 }
5127
5128 /* Handle a "constructor" attribute; arguments as in
5129    struct attribute_spec.handler.  */
5130
5131 static tree
5132 handle_constructor_attribute (tree *node, tree name, tree args,
5133                               int ARG_UNUSED (flags),
5134                               bool *no_add_attrs)
5135 {
5136   tree decl = *node;
5137   tree type = TREE_TYPE (decl);
5138
5139   if (TREE_CODE (decl) == FUNCTION_DECL
5140       && TREE_CODE (type) == FUNCTION_TYPE
5141       && decl_function_context (decl) == 0)
5142     {
5143       priority_type priority;
5144       DECL_STATIC_CONSTRUCTOR (decl) = 1;
5145       priority = get_priority (args, /*is_destructor=*/false);
5146       SET_DECL_INIT_PRIORITY (decl, priority);
5147       TREE_USED (decl) = 1;
5148     }
5149   else
5150     {
5151       warning (OPT_Wattributes, "%qE attribute ignored", name);
5152       *no_add_attrs = true;
5153     }
5154
5155   return NULL_TREE;
5156 }
5157
5158 /* Handle a "destructor" attribute; arguments as in
5159    struct attribute_spec.handler.  */
5160
5161 static tree
5162 handle_destructor_attribute (tree *node, tree name, tree args,
5163                              int ARG_UNUSED (flags),
5164                              bool *no_add_attrs)
5165 {
5166   tree decl = *node;
5167   tree type = TREE_TYPE (decl);
5168
5169   if (TREE_CODE (decl) == FUNCTION_DECL
5170       && TREE_CODE (type) == FUNCTION_TYPE
5171       && decl_function_context (decl) == 0)
5172     {
5173       priority_type priority;
5174       DECL_STATIC_DESTRUCTOR (decl) = 1;
5175       priority = get_priority (args, /*is_destructor=*/true);
5176       SET_DECL_FINI_PRIORITY (decl, priority);
5177       TREE_USED (decl) = 1;
5178     }
5179   else
5180     {
5181       warning (OPT_Wattributes, "%qE attribute ignored", name);
5182       *no_add_attrs = true;
5183     }
5184
5185   return NULL_TREE;
5186 }
5187
5188 /* Handle a "mode" attribute; arguments as in
5189    struct attribute_spec.handler.  */
5190
5191 static tree
5192 handle_mode_attribute (tree *node, tree name, tree args,
5193                        int ARG_UNUSED (flags), bool *no_add_attrs)
5194 {
5195   tree type = *node;
5196
5197   *no_add_attrs = true;
5198
5199   if (TREE_CODE (TREE_VALUE (args)) != IDENTIFIER_NODE)
5200     warning (OPT_Wattributes, "%qE attribute ignored", name);
5201   else
5202     {
5203       int j;
5204       const char *p = IDENTIFIER_POINTER (TREE_VALUE (args));
5205       int len = strlen (p);
5206       enum machine_mode mode = VOIDmode;
5207       tree typefm;
5208       bool valid_mode;
5209
5210       if (len > 4 && p[0] == '_' && p[1] == '_'
5211           && p[len - 1] == '_' && p[len - 2] == '_')
5212         {
5213           char *newp = (char *) alloca (len - 1);
5214
5215           strcpy (newp, &p[2]);
5216           newp[len - 4] = '\0';
5217           p = newp;
5218         }
5219
5220       /* Change this type to have a type with the specified mode.
5221          First check for the special modes.  */
5222       if (!strcmp (p, "byte"))
5223         mode = byte_mode;
5224       else if (!strcmp (p, "word"))
5225         mode = word_mode;
5226       else if (!strcmp (p, "pointer"))
5227         mode = ptr_mode;
5228       else if (!strcmp (p, "libgcc_cmp_return"))
5229         mode = targetm.libgcc_cmp_return_mode ();
5230       else if (!strcmp (p, "libgcc_shift_count"))
5231         mode = targetm.libgcc_shift_count_mode ();
5232       else
5233         for (j = 0; j < NUM_MACHINE_MODES; j++)
5234           if (!strcmp (p, GET_MODE_NAME (j)))
5235             {
5236               mode = (enum machine_mode) j;
5237               break;
5238             }
5239
5240       if (mode == VOIDmode)
5241         {
5242           error ("unknown machine mode %qs", p);
5243           return NULL_TREE;
5244         }
5245
5246       valid_mode = false;
5247       switch (GET_MODE_CLASS (mode))
5248         {
5249         case MODE_INT:
5250         case MODE_PARTIAL_INT:
5251         case MODE_FLOAT:
5252         case MODE_DECIMAL_FLOAT:
5253         case MODE_FRACT:
5254         case MODE_UFRACT:
5255         case MODE_ACCUM:
5256         case MODE_UACCUM:
5257           valid_mode = targetm.scalar_mode_supported_p (mode);
5258           break;
5259
5260         case MODE_COMPLEX_INT:
5261         case MODE_COMPLEX_FLOAT:
5262           valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode));
5263           break;
5264
5265         case MODE_VECTOR_INT:
5266         case MODE_VECTOR_FLOAT:
5267         case MODE_VECTOR_FRACT:
5268         case MODE_VECTOR_UFRACT:
5269         case MODE_VECTOR_ACCUM:
5270         case MODE_VECTOR_UACCUM:
5271           warning (OPT_Wattributes, "specifying vector types with "
5272                    "__attribute__ ((mode)) is deprecated");
5273           warning (OPT_Wattributes,
5274                    "use __attribute__ ((vector_size)) instead");
5275           valid_mode = vector_mode_valid_p (mode);
5276           break;
5277
5278         default:
5279           break;
5280         }
5281       if (!valid_mode)
5282         {
5283           error ("unable to emulate %qs", p);
5284           return NULL_TREE;
5285         }
5286
5287       if (POINTER_TYPE_P (type))
5288         {
5289           tree (*fn)(tree, enum machine_mode, bool);
5290
5291           if (!targetm.valid_pointer_mode (mode))
5292             {
5293               error ("invalid pointer mode %qs", p);
5294               return NULL_TREE;
5295             }
5296
5297           if (TREE_CODE (type) == POINTER_TYPE)
5298             fn = build_pointer_type_for_mode;
5299           else
5300             fn = build_reference_type_for_mode;
5301           typefm = fn (TREE_TYPE (type), mode, false);
5302         }
5303       else
5304         {
5305           /* For fixed-point modes, we need to test if the signness of type
5306              and the machine mode are consistent.  */
5307           if (ALL_FIXED_POINT_MODE_P (mode)
5308               && TYPE_UNSIGNED (type) != UNSIGNED_FIXED_POINT_MODE_P (mode))
5309             {
5310               error ("signness of type and machine mode %qs don't match", p);
5311               return NULL_TREE;
5312             }
5313           /* For fixed-point modes, we need to pass saturating info.  */
5314           typefm = lang_hooks.types.type_for_mode (mode,
5315                         ALL_FIXED_POINT_MODE_P (mode) ? TYPE_SATURATING (type)
5316                                                       : TYPE_UNSIGNED (type));
5317         }
5318
5319       if (typefm == NULL_TREE)
5320         {
5321           error ("no data type for mode %qs", p);
5322           return NULL_TREE;
5323         }
5324       else if (TREE_CODE (type) == ENUMERAL_TYPE)
5325         {
5326           /* For enumeral types, copy the precision from the integer
5327              type returned above.  If not an INTEGER_TYPE, we can't use
5328              this mode for this type.  */
5329           if (TREE_CODE (typefm) != INTEGER_TYPE)
5330             {
5331               error ("cannot use mode %qs for enumeral types", p);
5332               return NULL_TREE;
5333             }
5334
5335           if (flags & ATTR_FLAG_TYPE_IN_PLACE)
5336             {
5337               TYPE_PRECISION (type) = TYPE_PRECISION (typefm);
5338               typefm = type;
5339             }
5340           else
5341             {
5342               /* We cannot build a type variant, as there's code that assumes
5343                  that TYPE_MAIN_VARIANT has the same mode.  This includes the
5344                  debug generators.  Instead, create a subrange type.  This
5345                  results in all of the enumeral values being emitted only once
5346                  in the original, and the subtype gets them by reference.  */
5347               if (TYPE_UNSIGNED (type))
5348                 typefm = make_unsigned_type (TYPE_PRECISION (typefm));
5349               else
5350                 typefm = make_signed_type (TYPE_PRECISION (typefm));
5351               TREE_TYPE (typefm) = type;
5352             }
5353         }
5354       else if (VECTOR_MODE_P (mode)
5355                ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm))
5356                : TREE_CODE (type) != TREE_CODE (typefm))
5357         {
5358           error ("mode %qs applied to inappropriate type", p);
5359           return NULL_TREE;
5360         }
5361
5362       *node = typefm;
5363     }
5364
5365   return NULL_TREE;
5366 }
5367
5368 /* Handle a "section" attribute; arguments as in
5369    struct attribute_spec.handler.  */
5370
5371 static tree
5372 handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5373                           int ARG_UNUSED (flags), bool *no_add_attrs)
5374 {
5375   tree decl = *node;
5376
5377   if (targetm.have_named_sections)
5378     {
5379       user_defined_section_attribute = true;
5380
5381       if ((TREE_CODE (decl) == FUNCTION_DECL
5382            || TREE_CODE (decl) == VAR_DECL)
5383           && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
5384         {
5385           if (TREE_CODE (decl) == VAR_DECL
5386               && current_function_decl != NULL_TREE
5387               && !TREE_STATIC (decl))
5388             {
5389               error ("%Jsection attribute cannot be specified for "
5390                      "local variables", decl);
5391               *no_add_attrs = true;
5392             }
5393
5394           /* The decl may have already been given a section attribute
5395              from a previous declaration.  Ensure they match.  */
5396           else if (DECL_SECTION_NAME (decl) != NULL_TREE
5397                    && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
5398                               TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
5399             {
5400               error ("section of %q+D conflicts with previous declaration",
5401                      *node);
5402               *no_add_attrs = true;
5403             }
5404           else
5405             DECL_SECTION_NAME (decl) = TREE_VALUE (args);
5406         }
5407       else
5408         {
5409           error ("section attribute not allowed for %q+D", *node);
5410           *no_add_attrs = true;
5411         }
5412     }
5413   else
5414     {
5415       error ("%Jsection attributes are not supported for this target", *node);
5416       *no_add_attrs = true;
5417     }
5418
5419   return NULL_TREE;
5420 }
5421
5422 /* Handle a "aligned" attribute; arguments as in
5423    struct attribute_spec.handler.  */
5424
5425 static tree
5426 handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5427                           int flags, bool *no_add_attrs)
5428 {
5429   tree decl = NULL_TREE;
5430   tree *type = NULL;
5431   int is_type = 0;
5432   tree align_expr = (args ? TREE_VALUE (args)
5433                      : size_int (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
5434   int i;
5435
5436   if (DECL_P (*node))
5437     {
5438       decl = *node;
5439       type = &TREE_TYPE (decl);
5440       is_type = TREE_CODE (*node) == TYPE_DECL;
5441     }
5442   else if (TYPE_P (*node))
5443     type = node, is_type = 1;
5444
5445   if (TREE_CODE (align_expr) != INTEGER_CST)
5446     {
5447       error ("requested alignment is not a constant");
5448       *no_add_attrs = true;
5449     }
5450   else if ((i = tree_log2 (align_expr)) == -1)
5451     {
5452       error ("requested alignment is not a power of 2");
5453       *no_add_attrs = true;
5454     }
5455   else if (i > HOST_BITS_PER_INT - 2)
5456     {
5457       error ("requested alignment is too large");
5458       *no_add_attrs = true;
5459     }
5460   else if (is_type)
5461     {
5462       /* If we have a TYPE_DECL, then copy the type, so that we
5463          don't accidentally modify a builtin type.  See pushdecl.  */
5464       if (decl && TREE_TYPE (decl) != error_mark_node
5465           && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
5466         {
5467           tree tt = TREE_TYPE (decl);
5468           *type = build_variant_type_copy (*type);
5469           DECL_ORIGINAL_TYPE (decl) = tt;
5470           TYPE_NAME (*type) = decl;
5471           TREE_USED (*type) = TREE_USED (decl);
5472           TREE_TYPE (decl) = *type;
5473         }
5474       else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5475         *type = build_variant_type_copy (*type);
5476
5477       TYPE_ALIGN (*type) = (1 << i) * BITS_PER_UNIT;
5478       TYPE_USER_ALIGN (*type) = 1;
5479     }
5480   else if (! VAR_OR_FUNCTION_DECL_P (decl)
5481            && TREE_CODE (decl) != FIELD_DECL)
5482     {
5483       error ("alignment may not be specified for %q+D", decl);
5484       *no_add_attrs = true;
5485     }
5486   else if (TREE_CODE (decl) == FUNCTION_DECL
5487            && DECL_ALIGN (decl) > (1 << i) * BITS_PER_UNIT)
5488     {
5489       if (DECL_USER_ALIGN (decl))
5490         error ("alignment for %q+D was previously specified as %d "
5491                "and may not be decreased", decl,
5492                DECL_ALIGN (decl) / BITS_PER_UNIT);
5493       else
5494         error ("alignment for %q+D must be at least %d", decl,
5495                DECL_ALIGN (decl) / BITS_PER_UNIT);
5496       *no_add_attrs = true;
5497     }
5498   else
5499     {
5500       DECL_ALIGN (decl) = (1 << i) * BITS_PER_UNIT;
5501       DECL_USER_ALIGN (decl) = 1;
5502     }
5503
5504   return NULL_TREE;
5505 }
5506
5507 /* Handle a "weak" attribute; arguments as in
5508    struct attribute_spec.handler.  */
5509
5510 static tree
5511 handle_weak_attribute (tree *node, tree name,
5512                        tree ARG_UNUSED (args),
5513                        int ARG_UNUSED (flags),
5514                        bool * ARG_UNUSED (no_add_attrs))
5515 {
5516   if (TREE_CODE (*node) == FUNCTION_DECL
5517       || TREE_CODE (*node) == VAR_DECL)
5518     declare_weak (*node);
5519   else
5520     warning (OPT_Wattributes, "%qE attribute ignored", name);
5521
5522
5523   return NULL_TREE;
5524 }
5525
5526 /* Handle an "alias" attribute; arguments as in
5527    struct attribute_spec.handler.  */
5528
5529 static tree
5530 handle_alias_attribute (tree *node, tree name, tree args,
5531                         int ARG_UNUSED (flags), bool *no_add_attrs)
5532 {
5533   tree decl = *node;
5534
5535   if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
5536       || (TREE_CODE (decl) != FUNCTION_DECL
5537           && TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl))
5538       /* A static variable declaration is always a tentative definition,
5539          but the alias is a non-tentative definition which overrides.  */
5540       || (TREE_CODE (decl) != FUNCTION_DECL
5541           && ! TREE_PUBLIC (decl) && DECL_INITIAL (decl)))
5542     {
5543       error ("%q+D defined both normally and as an alias", decl);
5544       *no_add_attrs = true;
5545     }
5546
5547   /* Note that the very first time we process a nested declaration,
5548      decl_function_context will not be set.  Indeed, *would* never
5549      be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that
5550      we do below.  After such frobbery, pushdecl would set the context.
5551      In any case, this is never what we want.  */
5552   else if (decl_function_context (decl) == 0 && current_function_decl == NULL)
5553     {
5554       tree id;
5555
5556       id = TREE_VALUE (args);
5557       if (TREE_CODE (id) != STRING_CST)
5558         {
5559           error ("alias argument not a string");
5560           *no_add_attrs = true;
5561           return NULL_TREE;
5562         }
5563       id = get_identifier (TREE_STRING_POINTER (id));
5564       /* This counts as a use of the object pointed to.  */
5565       TREE_USED (id) = 1;
5566
5567       if (TREE_CODE (decl) == FUNCTION_DECL)
5568         DECL_INITIAL (decl) = error_mark_node;
5569       else
5570         {
5571           if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5572             DECL_EXTERNAL (decl) = 1;
5573           else
5574             DECL_EXTERNAL (decl) = 0;
5575           TREE_STATIC (decl) = 1;
5576         }
5577     }
5578   else
5579     {
5580       warning (OPT_Wattributes, "%qE attribute ignored", name);
5581       *no_add_attrs = true;
5582     }
5583
5584   return NULL_TREE;
5585 }
5586
5587 /* Handle a "weakref" attribute; arguments as in struct
5588    attribute_spec.handler.  */
5589
5590 static tree
5591 handle_weakref_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5592                           int flags, bool *no_add_attrs)
5593 {
5594   tree attr = NULL_TREE;
5595
5596   /* We must ignore the attribute when it is associated with
5597      local-scoped decls, since attribute alias is ignored and many
5598      such symbols do not even have a DECL_WEAK field.  */
5599   if (decl_function_context (*node) || current_function_decl)
5600     {
5601       warning (OPT_Wattributes, "%qE attribute ignored", name);
5602       *no_add_attrs = true;
5603       return NULL_TREE;
5604     }
5605
5606   /* The idea here is that `weakref("name")' mutates into `weakref,
5607      alias("name")', and weakref without arguments, in turn,
5608      implicitly adds weak. */
5609
5610   if (args)
5611     {
5612       attr = tree_cons (get_identifier ("alias"), args, attr);
5613       attr = tree_cons (get_identifier ("weakref"), NULL_TREE, attr);
5614
5615       *no_add_attrs = true;
5616
5617       decl_attributes (node, attr, flags);
5618     }
5619   else
5620     {
5621       if (lookup_attribute ("alias", DECL_ATTRIBUTES (*node)))
5622         error ("%Jweakref attribute must appear before alias attribute",
5623                *node);
5624
5625       /* Can't call declare_weak because it wants this to be TREE_PUBLIC,
5626          and that isn't supported; and because it wants to add it to
5627          the list of weak decls, which isn't helpful.  */
5628       DECL_WEAK (*node) = 1;
5629     }
5630
5631   return NULL_TREE;
5632 }
5633
5634 /* Handle an "visibility" attribute; arguments as in
5635    struct attribute_spec.handler.  */
5636
5637 static tree
5638 handle_visibility_attribute (tree *node, tree name, tree args,
5639                              int ARG_UNUSED (flags),
5640                              bool *ARG_UNUSED (no_add_attrs))
5641 {
5642   tree decl = *node;
5643   tree id = TREE_VALUE (args);
5644   enum symbol_visibility vis;
5645
5646   if (TYPE_P (*node))
5647     {
5648       if (TREE_CODE (*node) == ENUMERAL_TYPE)
5649         /* OK */;
5650       else if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE)
5651         {
5652           warning (OPT_Wattributes, "%qE attribute ignored on non-class types",
5653                    name);
5654           return NULL_TREE;
5655         }
5656       else if (TYPE_FIELDS (*node))
5657         {
5658           error ("%qE attribute ignored because %qT is already defined",
5659                  name, *node);
5660           return NULL_TREE;
5661         }
5662     }
5663   else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl))
5664     {
5665       warning (OPT_Wattributes, "%qE attribute ignored", name);
5666       return NULL_TREE;
5667     }
5668
5669   if (TREE_CODE (id) != STRING_CST)
5670     {
5671       error ("visibility argument not a string");
5672       return NULL_TREE;
5673     }
5674
5675   /*  If this is a type, set the visibility on the type decl.  */
5676   if (TYPE_P (decl))
5677     {
5678       decl = TYPE_NAME (decl);
5679       if (!decl)
5680         return NULL_TREE;
5681       if (TREE_CODE (decl) == IDENTIFIER_NODE)
5682         {
5683            warning (OPT_Wattributes, "%qE attribute ignored on types",
5684                     name);
5685            return NULL_TREE;
5686         }
5687     }
5688
5689   if (strcmp (TREE_STRING_POINTER (id), "default") == 0)
5690     vis = VISIBILITY_DEFAULT;
5691   else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0)
5692     vis = VISIBILITY_INTERNAL;
5693   else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0)
5694     vis = VISIBILITY_HIDDEN;
5695   else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0)
5696     vis = VISIBILITY_PROTECTED;
5697   else
5698     {
5699       error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\"");
5700       vis = VISIBILITY_DEFAULT;
5701     }
5702
5703   if (DECL_VISIBILITY_SPECIFIED (decl)
5704       && vis != DECL_VISIBILITY (decl))
5705     {
5706       tree attributes = (TYPE_P (*node)
5707                          ? TYPE_ATTRIBUTES (*node)
5708                          : DECL_ATTRIBUTES (decl));
5709       if (lookup_attribute ("visibility", attributes))
5710         error ("%qD redeclared with different visibility", decl);
5711       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
5712                && lookup_attribute ("dllimport", attributes))
5713         error ("%qD was declared %qs which implies default visibility",
5714                decl, "dllimport");
5715       else if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
5716                && lookup_attribute ("dllexport", attributes))
5717         error ("%qD was declared %qs which implies default visibility",
5718                decl, "dllexport");
5719     }
5720
5721   DECL_VISIBILITY (decl) = vis;
5722   DECL_VISIBILITY_SPECIFIED (decl) = 1;
5723
5724   /* Go ahead and attach the attribute to the node as well.  This is needed
5725      so we can determine whether we have VISIBILITY_DEFAULT because the
5726      visibility was not specified, or because it was explicitly overridden
5727      from the containing scope.  */
5728
5729   return NULL_TREE;
5730 }
5731
5732 /* Determine the ELF symbol visibility for DECL, which is either a
5733    variable or a function.  It is an error to use this function if a
5734    definition of DECL is not available in this translation unit.
5735    Returns true if the final visibility has been determined by this
5736    function; false if the caller is free to make additional
5737    modifications.  */
5738
5739 bool
5740 c_determine_visibility (tree decl)
5741 {
5742   gcc_assert (TREE_CODE (decl) == VAR_DECL
5743               || TREE_CODE (decl) == FUNCTION_DECL);
5744
5745   /* If the user explicitly specified the visibility with an
5746      attribute, honor that.  DECL_VISIBILITY will have been set during
5747      the processing of the attribute.  We check for an explicit
5748      attribute, rather than just checking DECL_VISIBILITY_SPECIFIED,
5749      to distinguish the use of an attribute from the use of a "#pragma
5750      GCC visibility push(...)"; in the latter case we still want other
5751      considerations to be able to overrule the #pragma.  */
5752   if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl))
5753       || (TARGET_DLLIMPORT_DECL_ATTRIBUTES
5754           && (lookup_attribute ("dllimport", DECL_ATTRIBUTES (decl))
5755               || lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))))
5756     return true;
5757
5758   /* Set default visibility to whatever the user supplied with
5759      visibility_specified depending on #pragma GCC visibility.  */
5760   if (!DECL_VISIBILITY_SPECIFIED (decl))
5761     {
5762       DECL_VISIBILITY (decl) = default_visibility;
5763       DECL_VISIBILITY_SPECIFIED (decl) = visibility_options.inpragma;
5764     }
5765   return false;
5766 }
5767
5768 /* Handle an "tls_model" attribute; arguments as in
5769    struct attribute_spec.handler.  */
5770
5771 static tree
5772 handle_tls_model_attribute (tree *node, tree name, tree args,
5773                             int ARG_UNUSED (flags), bool *no_add_attrs)
5774 {
5775   tree id;
5776   tree decl = *node;
5777   enum tls_model kind;
5778
5779   *no_add_attrs = true;
5780
5781   if (!DECL_THREAD_LOCAL_P (decl))
5782     {
5783       warning (OPT_Wattributes, "%qE attribute ignored", name);
5784       return NULL_TREE;
5785     }
5786
5787   kind = DECL_TLS_MODEL (decl);
5788   id = TREE_VALUE (args);
5789   if (TREE_CODE (id) != STRING_CST)
5790     {
5791       error ("tls_model argument not a string");
5792       return NULL_TREE;
5793     }
5794
5795   if (!strcmp (TREE_STRING_POINTER (id), "local-exec"))
5796     kind = TLS_MODEL_LOCAL_EXEC;
5797   else if (!strcmp (TREE_STRING_POINTER (id), "initial-exec"))
5798     kind = TLS_MODEL_INITIAL_EXEC;
5799   else if (!strcmp (TREE_STRING_POINTER (id), "local-dynamic"))
5800     kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
5801   else if (!strcmp (TREE_STRING_POINTER (id), "global-dynamic"))
5802     kind = TLS_MODEL_GLOBAL_DYNAMIC;
5803   else
5804     error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\"");
5805
5806   DECL_TLS_MODEL (decl) = kind;
5807   return NULL_TREE;
5808 }
5809
5810 /* Handle a "no_instrument_function" attribute; arguments as in
5811    struct attribute_spec.handler.  */
5812
5813 static tree
5814 handle_no_instrument_function_attribute (tree *node, tree name,
5815                                          tree ARG_UNUSED (args),
5816                                          int ARG_UNUSED (flags),
5817                                          bool *no_add_attrs)
5818 {
5819   tree decl = *node;
5820
5821   if (TREE_CODE (decl) != FUNCTION_DECL)
5822     {
5823       error ("%J%qE attribute applies only to functions", decl, name);
5824       *no_add_attrs = true;
5825     }
5826   else if (DECL_INITIAL (decl))
5827     {
5828       error ("%Jcan%'t set %qE attribute after definition", decl, name);
5829       *no_add_attrs = true;
5830     }
5831   else
5832     DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
5833
5834   return NULL_TREE;
5835 }
5836
5837 /* Handle a "malloc" attribute; arguments as in
5838    struct attribute_spec.handler.  */
5839
5840 static tree
5841 handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5842                          int ARG_UNUSED (flags), bool *no_add_attrs)
5843 {
5844   if (TREE_CODE (*node) == FUNCTION_DECL
5845       && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node))))
5846     DECL_IS_MALLOC (*node) = 1;
5847   else
5848     {
5849       warning (OPT_Wattributes, "%qE attribute ignored", name);
5850       *no_add_attrs = true;
5851     }
5852
5853   return NULL_TREE;
5854 }
5855
5856 /* Handle a "alloc_size" attribute; arguments as in
5857    struct attribute_spec.handler.  */
5858
5859 static tree
5860 handle_alloc_size_attribute (tree *node, tree ARG_UNUSED (name), tree args,
5861                              int ARG_UNUSED (flags), bool *no_add_attrs)
5862 {
5863   tree params = TYPE_ARG_TYPES (*node);
5864   unsigned arg_count = 0;
5865
5866   for (; TREE_CHAIN (params); params = TREE_CHAIN (params))
5867     arg_count ++;
5868
5869   for (; args; args = TREE_CHAIN (args))
5870     {
5871       tree position = TREE_VALUE (args);
5872
5873       if (TREE_CODE (position) != INTEGER_CST
5874           || TREE_INT_CST_HIGH (position)
5875           || TREE_INT_CST_LOW (position) < 1
5876           || TREE_INT_CST_LOW (position) > arg_count )
5877         {
5878           warning (OPT_Wattributes,
5879                    "alloc_size parameter outside range");
5880           *no_add_attrs = true;
5881           return NULL_TREE;
5882         }
5883     }
5884   return NULL_TREE;
5885 }
5886
5887 /* Handle a "returns_twice" attribute; arguments as in
5888    struct attribute_spec.handler.  */
5889
5890 static tree
5891 handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5892                          int ARG_UNUSED (flags), bool *no_add_attrs)
5893 {
5894   if (TREE_CODE (*node) == FUNCTION_DECL)
5895     DECL_IS_RETURNS_TWICE (*node) = 1;
5896   else
5897     {
5898       warning (OPT_Wattributes, "%qE attribute ignored", name);
5899       *no_add_attrs = true;
5900     }
5901
5902   return NULL_TREE;
5903 }
5904
5905 /* Handle a "no_limit_stack" attribute; arguments as in
5906    struct attribute_spec.handler.  */
5907
5908 static tree
5909 handle_no_limit_stack_attribute (tree *node, tree name,
5910                                  tree ARG_UNUSED (args),
5911                                  int ARG_UNUSED (flags),
5912                                  bool *no_add_attrs)
5913 {
5914   tree decl = *node;
5915
5916   if (TREE_CODE (decl) != FUNCTION_DECL)
5917     {
5918       error ("%J%qE attribute applies only to functions", decl, name);
5919       *no_add_attrs = true;
5920     }
5921   else if (DECL_INITIAL (decl))
5922     {
5923       error ("%Jcan%'t set %qE attribute after definition", decl, name);
5924       *no_add_attrs = true;
5925     }
5926   else
5927     DECL_NO_LIMIT_STACK (decl) = 1;
5928
5929   return NULL_TREE;
5930 }
5931
5932 /* Handle a "pure" attribute; arguments as in
5933    struct attribute_spec.handler.  */
5934
5935 static tree
5936 handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5937                        int ARG_UNUSED (flags), bool *no_add_attrs)
5938 {
5939   if (TREE_CODE (*node) == FUNCTION_DECL)
5940     DECL_IS_PURE (*node) = 1;
5941   /* ??? TODO: Support types.  */
5942   else
5943     {
5944       warning (OPT_Wattributes, "%qE attribute ignored", name);
5945       *no_add_attrs = true;
5946     }
5947
5948   return NULL_TREE;
5949 }
5950
5951 /* Handle a "no vops" attribute; arguments as in
5952    struct attribute_spec.handler.  */
5953
5954 static tree
5955 handle_novops_attribute (tree *node, tree ARG_UNUSED (name),
5956                          tree ARG_UNUSED (args), int ARG_UNUSED (flags),
5957                          bool *ARG_UNUSED (no_add_attrs))
5958 {
5959   gcc_assert (TREE_CODE (*node) == FUNCTION_DECL);
5960   DECL_IS_NOVOPS (*node) = 1;
5961   return NULL_TREE;
5962 }
5963
5964 /* Handle a "deprecated" attribute; arguments as in
5965    struct attribute_spec.handler.  */
5966
5967 static tree
5968 handle_deprecated_attribute (tree *node, tree name,
5969                              tree ARG_UNUSED (args), int flags,
5970                              bool *no_add_attrs)
5971 {
5972   tree type = NULL_TREE;
5973   int warn = 0;
5974   tree what = NULL_TREE;
5975
5976   if (DECL_P (*node))
5977     {
5978       tree decl = *node;
5979       type = TREE_TYPE (decl);
5980
5981       if (TREE_CODE (decl) == TYPE_DECL
5982           || TREE_CODE (decl) == PARM_DECL
5983           || TREE_CODE (decl) == VAR_DECL
5984           || TREE_CODE (decl) == FUNCTION_DECL
5985           || TREE_CODE (decl) == FIELD_DECL)
5986         TREE_DEPRECATED (decl) = 1;
5987       else
5988         warn = 1;
5989     }
5990   else if (TYPE_P (*node))
5991     {
5992       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5993         *node = build_variant_type_copy (*node);
5994       TREE_DEPRECATED (*node) = 1;
5995       type = *node;
5996     }
5997   else
5998     warn = 1;
5999
6000   if (warn)
6001     {
6002       *no_add_attrs = true;
6003       if (type && TYPE_NAME (type))
6004         {
6005           if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
6006             what = TYPE_NAME (*node);
6007           else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
6008                    && DECL_NAME (TYPE_NAME (type)))
6009             what = DECL_NAME (TYPE_NAME (type));
6010         }
6011       if (what)
6012         warning (OPT_Wattributes, "%qE attribute ignored for %qE", name, what);
6013       else
6014         warning (OPT_Wattributes, "%qE attribute ignored", name);
6015     }
6016
6017   return NULL_TREE;
6018 }
6019
6020 /* Handle a "vector_size" attribute; arguments as in
6021    struct attribute_spec.handler.  */
6022
6023 static tree
6024 handle_vector_size_attribute (tree *node, tree name, tree args,
6025                               int ARG_UNUSED (flags),
6026                               bool *no_add_attrs)
6027 {
6028   unsigned HOST_WIDE_INT vecsize, nunits;
6029   enum machine_mode orig_mode;
6030   tree type = *node, new_type, size;
6031
6032   *no_add_attrs = true;
6033
6034   size = TREE_VALUE (args);
6035
6036   if (!host_integerp (size, 1))
6037     {
6038       warning (OPT_Wattributes, "%qE attribute ignored", name);
6039       return NULL_TREE;
6040     }
6041
6042   /* Get the vector size (in bytes).  */
6043   vecsize = tree_low_cst (size, 1);
6044
6045   /* We need to provide for vector pointers, vector arrays, and
6046      functions returning vectors.  For example:
6047
6048        __attribute__((vector_size(16))) short *foo;
6049
6050      In this case, the mode is SI, but the type being modified is
6051      HI, so we need to look further.  */
6052
6053   while (POINTER_TYPE_P (type)
6054          || TREE_CODE (type) == FUNCTION_TYPE
6055          || TREE_CODE (type) == METHOD_TYPE
6056          || TREE_CODE (type) == ARRAY_TYPE
6057          || TREE_CODE (type) == OFFSET_TYPE)
6058     type = TREE_TYPE (type);
6059
6060   /* Get the mode of the type being modified.  */
6061   orig_mode = TYPE_MODE (type);
6062
6063   if ((!INTEGRAL_TYPE_P (type)
6064        && !SCALAR_FLOAT_TYPE_P (type)
6065        && !FIXED_POINT_TYPE_P (type))
6066       || (!SCALAR_FLOAT_MODE_P (orig_mode)
6067           && GET_MODE_CLASS (orig_mode) != MODE_INT
6068           && !ALL_SCALAR_FIXED_POINT_MODE_P (orig_mode))
6069       || !host_integerp (TYPE_SIZE_UNIT (type), 1))
6070     {
6071       error ("invalid vector type for attribute %qE", name);
6072       return NULL_TREE;
6073     }
6074
6075   if (vecsize % tree_low_cst (TYPE_SIZE_UNIT (type), 1))
6076     {
6077       error ("vector size not an integral multiple of component size");
6078       return NULL;
6079     }
6080
6081   if (vecsize == 0)
6082     {
6083       error ("zero vector size");
6084       return NULL;
6085     }
6086
6087   /* Calculate how many units fit in the vector.  */
6088   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
6089   if (nunits & (nunits - 1))
6090     {
6091       error ("number of components of the vector not a power of two");
6092       return NULL_TREE;
6093     }
6094
6095   new_type = build_vector_type (type, nunits);
6096
6097   /* Build back pointers if needed.  */
6098   *node = reconstruct_complex_type (*node, new_type);
6099
6100   return NULL_TREE;
6101 }
6102
6103 /* Handle the "nonnull" attribute.  */
6104 static tree
6105 handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
6106                           tree args, int ARG_UNUSED (flags),
6107                           bool *no_add_attrs)
6108 {
6109   tree type = *node;
6110   unsigned HOST_WIDE_INT attr_arg_num;
6111
6112   /* If no arguments are specified, all pointer arguments should be
6113      non-null.  Verify a full prototype is given so that the arguments
6114      will have the correct types when we actually check them later.  */
6115   if (!args)
6116     {
6117       if (!TYPE_ARG_TYPES (type))
6118         {
6119           error ("nonnull attribute without arguments on a non-prototype");
6120           *no_add_attrs = true;
6121         }
6122       return NULL_TREE;
6123     }
6124
6125   /* Argument list specified.  Verify that each argument number references
6126      a pointer argument.  */
6127   for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
6128     {
6129       tree argument;
6130       unsigned HOST_WIDE_INT arg_num = 0, ck_num;
6131
6132       if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
6133         {
6134           error ("nonnull argument has invalid operand number (argument %lu)",
6135                  (unsigned long) attr_arg_num);
6136           *no_add_attrs = true;
6137           return NULL_TREE;
6138         }
6139
6140       argument = TYPE_ARG_TYPES (type);
6141       if (argument)
6142         {
6143           for (ck_num = 1; ; ck_num++)
6144             {
6145               if (!argument || ck_num == arg_num)
6146                 break;
6147               argument = TREE_CHAIN (argument);
6148             }
6149
6150           if (!argument
6151               || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
6152             {
6153               error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)",
6154                      (unsigned long) attr_arg_num, (unsigned long) arg_num);
6155               *no_add_attrs = true;
6156               return NULL_TREE;
6157             }
6158
6159           if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
6160             {
6161               error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)",
6162                    (unsigned long) attr_arg_num, (unsigned long) arg_num);
6163               *no_add_attrs = true;
6164               return NULL_TREE;
6165             }
6166         }
6167     }
6168
6169   return NULL_TREE;
6170 }
6171
6172 /* Check the argument list of a function call for null in argument slots
6173    that are marked as requiring a non-null pointer argument.  The NARGS
6174    arguments are passed in the array ARGARRAY.
6175 */
6176
6177 static void
6178 check_function_nonnull (tree attrs, int nargs, tree *argarray)
6179 {
6180   tree a, args;
6181   int i;
6182
6183   for (a = attrs; a; a = TREE_CHAIN (a))
6184     {
6185       if (is_attribute_p ("nonnull", TREE_PURPOSE (a)))
6186         {
6187           args = TREE_VALUE (a);
6188
6189           /* Walk the argument list.  If we encounter an argument number we
6190              should check for non-null, do it.  If the attribute has no args,
6191              then every pointer argument is checked (in which case the check
6192              for pointer type is done in check_nonnull_arg).  */
6193           for (i = 0; i < nargs; i++)
6194             {
6195               if (!args || nonnull_check_p (args, i + 1))
6196                 check_function_arguments_recurse (check_nonnull_arg, NULL,
6197                                                   argarray[i],
6198                                                   i + 1);
6199             }
6200         }
6201     }
6202 }
6203
6204 /* Check that the Nth argument of a function call (counting backwards
6205    from the end) is a (pointer)0.  The NARGS arguments are passed in the
6206    array ARGARRAY.  */
6207
6208 static void
6209 check_function_sentinel (tree attrs, int nargs, tree *argarray, tree typelist)
6210 {
6211   tree attr = lookup_attribute ("sentinel", attrs);
6212
6213   if (attr)
6214     {
6215       int len = 0;
6216       int pos = 0;
6217       tree sentinel;
6218
6219       /* Skip over the named arguments.  */
6220       while (typelist && len < nargs)
6221         {
6222           typelist = TREE_CHAIN (typelist);
6223           len++;
6224         }
6225
6226       if (TREE_VALUE (attr))
6227         {
6228           tree p = TREE_VALUE (TREE_VALUE (attr));
6229           pos = TREE_INT_CST_LOW (p);
6230         }
6231
6232       /* The sentinel must be one of the varargs, i.e.
6233          in position >= the number of fixed arguments.  */
6234       if ((nargs - 1 - pos) < len)
6235         {
6236           warning (OPT_Wformat,
6237                    "not enough variable arguments to fit a sentinel");
6238           return;
6239         }
6240
6241       /* Validate the sentinel.  */
6242       sentinel = argarray[nargs - 1 - pos];
6243       if ((!POINTER_TYPE_P (TREE_TYPE (sentinel))
6244            || !integer_zerop (sentinel))
6245           /* Although __null (in C++) is only an integer we allow it
6246              nevertheless, as we are guaranteed that it's exactly
6247              as wide as a pointer, and we don't want to force
6248              users to cast the NULL they have written there.
6249              We warn with -Wstrict-null-sentinel, though.  */
6250           && (warn_strict_null_sentinel || null_node != sentinel))
6251         warning (OPT_Wformat, "missing sentinel in function call");
6252     }
6253 }
6254
6255 /* Helper for check_function_nonnull; given a list of operands which
6256    must be non-null in ARGS, determine if operand PARAM_NUM should be
6257    checked.  */
6258
6259 static bool
6260 nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num)
6261 {
6262   unsigned HOST_WIDE_INT arg_num = 0;
6263
6264   for (; args; args = TREE_CHAIN (args))
6265     {
6266       bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num);
6267
6268       gcc_assert (found);
6269
6270       if (arg_num == param_num)
6271         return true;
6272     }
6273   return false;
6274 }
6275
6276 /* Check that the function argument PARAM (which is operand number
6277    PARAM_NUM) is non-null.  This is called by check_function_nonnull
6278    via check_function_arguments_recurse.  */
6279
6280 static void
6281 check_nonnull_arg (void * ARG_UNUSED (ctx), tree param,
6282                    unsigned HOST_WIDE_INT param_num)
6283 {
6284   /* Just skip checking the argument if it's not a pointer.  This can
6285      happen if the "nonnull" attribute was given without an operand
6286      list (which means to check every pointer argument).  */
6287
6288   if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE)
6289     return;
6290
6291   if (integer_zerop (param))
6292     warning (OPT_Wnonnull, "null argument where non-null required "
6293              "(argument %lu)", (unsigned long) param_num);
6294 }
6295
6296 /* Helper for nonnull attribute handling; fetch the operand number
6297    from the attribute argument list.  */
6298
6299 static bool
6300 get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp)
6301 {
6302   /* Verify the arg number is a constant.  */
6303   if (TREE_CODE (arg_num_expr) != INTEGER_CST
6304       || TREE_INT_CST_HIGH (arg_num_expr) != 0)
6305     return false;
6306
6307   *valp = TREE_INT_CST_LOW (arg_num_expr);
6308   return true;
6309 }
6310
6311 /* Handle a "nothrow" attribute; arguments as in
6312    struct attribute_spec.handler.  */
6313
6314 static tree
6315 handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args),
6316                           int ARG_UNUSED (flags), bool *no_add_attrs)
6317 {
6318   if (TREE_CODE (*node) == FUNCTION_DECL)
6319     TREE_NOTHROW (*node) = 1;
6320   /* ??? TODO: Support types.  */
6321   else
6322     {
6323       warning (OPT_Wattributes, "%qE attribute ignored", name);
6324       *no_add_attrs = true;
6325     }
6326
6327   return NULL_TREE;
6328 }
6329
6330 /* Handle a "cleanup" attribute; arguments as in
6331    struct attribute_spec.handler.  */
6332
6333 static tree
6334 handle_cleanup_attribute (tree *node, tree name, tree args,
6335                           int ARG_UNUSED (flags), bool *no_add_attrs)
6336 {
6337   tree decl = *node;
6338   tree cleanup_id, cleanup_decl;
6339
6340   /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do
6341      for global destructors in C++.  This requires infrastructure that
6342      we don't have generically at the moment.  It's also not a feature
6343      we'd be missing too much, since we do have attribute constructor.  */
6344   if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl))
6345     {
6346       warning (OPT_Wattributes, "%qE attribute ignored", name);
6347       *no_add_attrs = true;
6348       return NULL_TREE;
6349     }
6350
6351   /* Verify that the argument is a function in scope.  */
6352   /* ??? We could support pointers to functions here as well, if
6353      that was considered desirable.  */
6354   cleanup_id = TREE_VALUE (args);
6355   if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE)
6356     {
6357       error ("cleanup argument not an identifier");
6358       *no_add_attrs = true;
6359       return NULL_TREE;
6360     }
6361   cleanup_decl = lookup_name (cleanup_id);
6362   if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL)
6363     {
6364       error ("cleanup argument not a function");
6365       *no_add_attrs = true;
6366       return NULL_TREE;
6367     }
6368
6369   /* That the function has proper type is checked with the
6370      eventual call to build_function_call.  */
6371
6372   return NULL_TREE;
6373 }
6374
6375 /* Handle a "warn_unused_result" attribute.  No special handling.  */
6376
6377 static tree
6378 handle_warn_unused_result_attribute (tree *node, tree name,
6379                                tree ARG_UNUSED (args),
6380                                int ARG_UNUSED (flags), bool *no_add_attrs)
6381 {
6382   /* Ignore the attribute for functions not returning any value.  */
6383   if (VOID_TYPE_P (TREE_TYPE (*node)))
6384     {
6385       warning (OPT_Wattributes, "%qE attribute ignored", name);
6386       *no_add_attrs = true;
6387     }
6388
6389   return NULL_TREE;
6390 }
6391
6392 /* Handle a "sentinel" attribute.  */
6393
6394 static tree
6395 handle_sentinel_attribute (tree *node, tree name, tree args,
6396                            int ARG_UNUSED (flags), bool *no_add_attrs)
6397 {
6398   tree params = TYPE_ARG_TYPES (*node);
6399
6400   if (!params)
6401     {
6402       warning (OPT_Wattributes,
6403                "%qE attribute requires prototypes with named arguments", name);
6404       *no_add_attrs = true;
6405     }
6406   else
6407     {
6408       while (TREE_CHAIN (params))
6409         params = TREE_CHAIN (params);
6410
6411       if (VOID_TYPE_P (TREE_VALUE (params)))
6412         {
6413           warning (OPT_Wattributes,
6414                    "%qE attribute only applies to variadic functions", name);
6415           *no_add_attrs = true;
6416         }
6417     }
6418
6419   if (args)
6420     {
6421       tree position = TREE_VALUE (args);
6422
6423       if (TREE_CODE (position) != INTEGER_CST)
6424         {
6425           warning (OPT_Wattributes,
6426                    "requested position is not an integer constant");
6427           *no_add_attrs = true;
6428         }
6429       else
6430         {
6431           if (tree_int_cst_lt (position, integer_zero_node))
6432             {
6433               warning (OPT_Wattributes,
6434                        "requested position is less than zero");
6435               *no_add_attrs = true;
6436             }
6437         }
6438     }
6439
6440   return NULL_TREE;
6441 }
6442
6443 /* Handle a "type_generic" attribute.  */
6444
6445 static tree
6446 handle_type_generic_attribute (tree *node, tree ARG_UNUSED (name),
6447                                tree ARG_UNUSED (args), int ARG_UNUSED (flags),
6448                                bool * ARG_UNUSED (no_add_attrs))
6449 {
6450   /* Ensure we have a function type, with no arguments.  */
6451   gcc_assert (TREE_CODE (*node) == FUNCTION_TYPE && ! TYPE_ARG_TYPES (*node));
6452
6453   return NULL_TREE;
6454 }
6455 \f
6456 /* Check for valid arguments being passed to a function.
6457    ATTRS is a list of attributes.  There are NARGS arguments in the array
6458    ARGARRAY.  TYPELIST is the list of argument types for the function.
6459  */
6460 void
6461 check_function_arguments (tree attrs, int nargs, tree *argarray, tree typelist)
6462 {
6463   /* Check for null being passed in a pointer argument that must be
6464      non-null.  We also need to do this if format checking is enabled.  */
6465
6466   if (warn_nonnull)
6467     check_function_nonnull (attrs, nargs, argarray);
6468
6469   /* Check for errors in format strings.  */
6470
6471   if (warn_format || warn_missing_format_attribute)
6472     check_function_format (attrs, nargs, argarray);
6473
6474   if (warn_format)
6475     check_function_sentinel (attrs, nargs, argarray, typelist);
6476 }
6477
6478 /* Generic argument checking recursion routine.  PARAM is the argument to
6479    be checked.  PARAM_NUM is the number of the argument.  CALLBACK is invoked
6480    once the argument is resolved.  CTX is context for the callback.  */
6481 void
6482 check_function_arguments_recurse (void (*callback)
6483                                   (void *, tree, unsigned HOST_WIDE_INT),
6484                                   void *ctx, tree param,
6485                                   unsigned HOST_WIDE_INT param_num)
6486 {
6487   if ((TREE_CODE (param) == NOP_EXPR || TREE_CODE (param) == CONVERT_EXPR)
6488       && (TYPE_PRECISION (TREE_TYPE (param))
6489           == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (param, 0)))))
6490     {
6491       /* Strip coercion.  */
6492       check_function_arguments_recurse (callback, ctx,
6493                                         TREE_OPERAND (param, 0), param_num);
6494       return;
6495     }
6496
6497   if (TREE_CODE (param) == CALL_EXPR)
6498     {
6499       tree type = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (param)));
6500       tree attrs;
6501       bool found_format_arg = false;
6502
6503       /* See if this is a call to a known internationalization function
6504          that modifies a format arg.  Such a function may have multiple
6505          format_arg attributes (for example, ngettext).  */
6506
6507       for (attrs = TYPE_ATTRIBUTES (type);
6508            attrs;
6509            attrs = TREE_CHAIN (attrs))
6510         if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs)))
6511           {
6512             tree inner_arg;
6513             tree format_num_expr;
6514             int format_num;
6515             int i;
6516             call_expr_arg_iterator iter;
6517
6518             /* Extract the argument number, which was previously checked
6519                to be valid.  */
6520             format_num_expr = TREE_VALUE (TREE_VALUE (attrs));
6521
6522             gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST
6523                         && !TREE_INT_CST_HIGH (format_num_expr));
6524
6525             format_num = TREE_INT_CST_LOW (format_num_expr);
6526
6527             for (inner_arg = first_call_expr_arg (param, &iter), i = 1;
6528                  inner_arg != 0;
6529                  inner_arg = next_call_expr_arg (&iter), i++)
6530               if (i == format_num)
6531                 {
6532                   check_function_arguments_recurse (callback, ctx,
6533                                                     inner_arg, param_num);
6534                   found_format_arg = true;
6535                   break;
6536                 }
6537           }
6538
6539       /* If we found a format_arg attribute and did a recursive check,
6540          we are done with checking this argument.  Otherwise, we continue
6541          and this will be considered a non-literal.  */
6542       if (found_format_arg)
6543         return;
6544     }
6545
6546   if (TREE_CODE (param) == COND_EXPR)
6547     {
6548       /* Check both halves of the conditional expression.  */
6549       check_function_arguments_recurse (callback, ctx,
6550                                         TREE_OPERAND (param, 1), param_num);
6551       check_function_arguments_recurse (callback, ctx,
6552                                         TREE_OPERAND (param, 2), param_num);
6553       return;
6554     }
6555
6556   (*callback) (ctx, param, param_num);
6557 }
6558
6559 /* Function to help qsort sort FIELD_DECLs by name order.  */
6560
6561 int
6562 field_decl_cmp (const void *x_p, const void *y_p)
6563 {
6564   const tree *const x = (const tree *const) x_p;
6565   const tree *const y = (const tree *const) y_p;
6566
6567   if (DECL_NAME (*x) == DECL_NAME (*y))
6568     /* A nontype is "greater" than a type.  */
6569     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
6570   if (DECL_NAME (*x) == NULL_TREE)
6571     return -1;
6572   if (DECL_NAME (*y) == NULL_TREE)
6573     return 1;
6574   if (DECL_NAME (*x) < DECL_NAME (*y))
6575     return -1;
6576   return 1;
6577 }
6578
6579 static struct {
6580   gt_pointer_operator new_value;
6581   void *cookie;
6582 } resort_data;
6583
6584 /* This routine compares two fields like field_decl_cmp but using the
6585 pointer operator in resort_data.  */
6586
6587 static int
6588 resort_field_decl_cmp (const void *x_p, const void *y_p)
6589 {
6590   const tree *const x = (const tree *const) x_p;
6591   const tree *const y = (const tree *const) y_p;
6592
6593   if (DECL_NAME (*x) == DECL_NAME (*y))
6594     /* A nontype is "greater" than a type.  */
6595     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
6596   if (DECL_NAME (*x) == NULL_TREE)
6597     return -1;
6598   if (DECL_NAME (*y) == NULL_TREE)
6599     return 1;
6600   {
6601     tree d1 = DECL_NAME (*x);
6602     tree d2 = DECL_NAME (*y);
6603     resort_data.new_value (&d1, resort_data.cookie);
6604     resort_data.new_value (&d2, resort_data.cookie);
6605     if (d1 < d2)
6606       return -1;
6607   }
6608   return 1;
6609 }
6610
6611 /* Resort DECL_SORTED_FIELDS because pointers have been reordered.  */
6612
6613 void
6614 resort_sorted_fields (void *obj,
6615                       void * ARG_UNUSED (orig_obj),
6616                       gt_pointer_operator new_value,
6617                       void *cookie)
6618 {
6619   struct sorted_fields_type *sf = (struct sorted_fields_type *) obj;
6620   resort_data.new_value = new_value;
6621   resort_data.cookie = cookie;
6622   qsort (&sf->elts[0], sf->len, sizeof (tree),
6623          resort_field_decl_cmp);
6624 }
6625
6626 /* Subroutine of c_parse_error.
6627    Return the result of concatenating LHS and RHS. RHS is really
6628    a string literal, its first character is indicated by RHS_START and
6629    RHS_SIZE is its length (including the terminating NUL character).
6630
6631    The caller is responsible for deleting the returned pointer.  */
6632
6633 static char *
6634 catenate_strings (const char *lhs, const char *rhs_start, int rhs_size)
6635 {
6636   const int lhs_size = strlen (lhs);
6637   char *result = XNEWVEC (char, lhs_size + rhs_size);
6638   strncpy (result, lhs, lhs_size);
6639   strncpy (result + lhs_size, rhs_start, rhs_size);
6640   return result;
6641 }
6642
6643 /* Issue the error given by GMSGID, indicating that it occurred before
6644    TOKEN, which had the associated VALUE.  */
6645
6646 void
6647 c_parse_error (const char *gmsgid, enum cpp_ttype token, tree value)
6648 {
6649 #define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2))
6650
6651   char *message = NULL;
6652
6653   if (token == CPP_EOF)
6654     message = catenate_messages (gmsgid, " at end of input");
6655   else if (token == CPP_CHAR || token == CPP_WCHAR)
6656     {
6657       unsigned int val = TREE_INT_CST_LOW (value);
6658       const char *const ell = (token == CPP_CHAR) ? "" : "L";
6659       if (val <= UCHAR_MAX && ISGRAPH (val))
6660         message = catenate_messages (gmsgid, " before %s'%c'");
6661       else
6662         message = catenate_messages (gmsgid, " before %s'\\x%x'");
6663
6664       error (message, ell, val);
6665       free (message);
6666       message = NULL;
6667     }
6668   else if (token == CPP_STRING || token == CPP_WSTRING)
6669     message = catenate_messages (gmsgid, " before string constant");
6670   else if (token == CPP_NUMBER)
6671     message = catenate_messages (gmsgid, " before numeric constant");
6672   else if (token == CPP_NAME)
6673     {
6674       message = catenate_messages (gmsgid, " before %qE");
6675       error (message, value);
6676       free (message);
6677       message = NULL;
6678     }
6679   else if (token == CPP_PRAGMA)
6680     message = catenate_messages (gmsgid, " before %<#pragma%>");
6681   else if (token == CPP_PRAGMA_EOL)
6682     message = catenate_messages (gmsgid, " before end of line");
6683   else if (token < N_TTYPES)
6684     {
6685       message = catenate_messages (gmsgid, " before %qs token");
6686       error (message, cpp_type2name (token));
6687       free (message);
6688       message = NULL;
6689     }
6690   else
6691     error (gmsgid);
6692
6693   if (message)
6694     {
6695       error (message);
6696       free (message);
6697     }
6698 #undef catenate_messages
6699 }
6700
6701 /* Walk a gimplified function and warn for functions whose return value is
6702    ignored and attribute((warn_unused_result)) is set.  This is done before
6703    inlining, so we don't have to worry about that.  */
6704
6705 void
6706 c_warn_unused_result (tree *top_p)
6707 {
6708   tree t = *top_p;
6709   tree_stmt_iterator i;
6710   tree fdecl, ftype;
6711
6712   switch (TREE_CODE (t))
6713     {
6714     case STATEMENT_LIST:
6715       for (i = tsi_start (*top_p); !tsi_end_p (i); tsi_next (&i))
6716         c_warn_unused_result (tsi_stmt_ptr (i));
6717       break;
6718
6719     case COND_EXPR:
6720       c_warn_unused_result (&COND_EXPR_THEN (t));
6721       c_warn_unused_result (&COND_EXPR_ELSE (t));
6722       break;
6723     case BIND_EXPR:
6724       c_warn_unused_result (&BIND_EXPR_BODY (t));
6725       break;
6726     case TRY_FINALLY_EXPR:
6727     case TRY_CATCH_EXPR:
6728       c_warn_unused_result (&TREE_OPERAND (t, 0));
6729       c_warn_unused_result (&TREE_OPERAND (t, 1));
6730       break;
6731     case CATCH_EXPR:
6732       c_warn_unused_result (&CATCH_BODY (t));
6733       break;
6734     case EH_FILTER_EXPR:
6735       c_warn_unused_result (&EH_FILTER_FAILURE (t));
6736       break;
6737
6738     case CALL_EXPR:
6739       if (TREE_USED (t))
6740         break;
6741
6742       /* This is a naked call, as opposed to a CALL_EXPR nested inside
6743          a MODIFY_EXPR.  All calls whose value is ignored should be
6744          represented like this.  Look for the attribute.  */
6745       fdecl = get_callee_fndecl (t);
6746       if (fdecl)
6747         ftype = TREE_TYPE (fdecl);
6748       else
6749         {
6750           ftype = TREE_TYPE (CALL_EXPR_FN (t));
6751           /* Look past pointer-to-function to the function type itself.  */
6752           ftype = TREE_TYPE (ftype);
6753         }
6754
6755       if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype)))
6756         {
6757           if (fdecl)
6758             warning (0, "%Hignoring return value of %qD, "
6759                      "declared with attribute warn_unused_result",
6760                      EXPR_LOCUS (t), fdecl);
6761           else
6762             warning (0, "%Hignoring return value of function "
6763                      "declared with attribute warn_unused_result",
6764                      EXPR_LOCUS (t));
6765         }
6766       break;
6767
6768     default:
6769       /* Not a container, not a call, or a call whose value is used.  */
6770       break;
6771     }
6772 }
6773
6774 /* Convert a character from the host to the target execution character
6775    set.  cpplib handles this, mostly.  */
6776
6777 HOST_WIDE_INT
6778 c_common_to_target_charset (HOST_WIDE_INT c)
6779 {
6780   /* Character constants in GCC proper are sign-extended under -fsigned-char,
6781      zero-extended under -fno-signed-char.  cpplib insists that characters
6782      and character constants are always unsigned.  Hence we must convert
6783      back and forth.  */
6784   cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1);
6785
6786   uc = cpp_host_to_exec_charset (parse_in, uc);
6787
6788   if (flag_signed_char)
6789     return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE)
6790                                >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE);
6791   else
6792     return uc;
6793 }
6794
6795 /* Build the result of __builtin_offsetof.  EXPR is a nested sequence of
6796    component references, with STOP_REF, or alternatively an INDIRECT_REF of
6797    NULL, at the bottom; much like the traditional rendering of offsetof as a
6798    macro.  Returns the folded and properly cast result.  */
6799
6800 static tree
6801 fold_offsetof_1 (tree expr, tree stop_ref)
6802 {
6803   enum tree_code code = PLUS_EXPR;
6804   tree base, off, t;
6805
6806   if (expr == stop_ref && TREE_CODE (expr) != ERROR_MARK)
6807     return size_zero_node;
6808
6809   switch (TREE_CODE (expr))
6810     {
6811     case ERROR_MARK:
6812       return expr;
6813
6814     case VAR_DECL:
6815       error ("cannot apply %<offsetof%> to static data member %qD", expr);
6816       return error_mark_node;
6817
6818     case CALL_EXPR:
6819       error ("cannot apply %<offsetof%> when %<operator[]%> is overloaded");
6820       return error_mark_node;
6821
6822     case INTEGER_CST:
6823       gcc_assert (integer_zerop (expr));
6824       return size_zero_node;
6825
6826     case NOP_EXPR:
6827     case INDIRECT_REF:
6828       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
6829       gcc_assert (base == error_mark_node || base == size_zero_node);
6830       return base;
6831
6832     case COMPONENT_REF:
6833       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
6834       if (base == error_mark_node)
6835         return base;
6836
6837       t = TREE_OPERAND (expr, 1);
6838       if (DECL_C_BIT_FIELD (t))
6839         {
6840           error ("attempt to take address of bit-field structure "
6841                  "member %qD", t);
6842           return error_mark_node;
6843         }
6844       off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t),
6845                         size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t), 1)
6846                                   / BITS_PER_UNIT));
6847       break;
6848
6849     case ARRAY_REF:
6850       base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
6851       if (base == error_mark_node)
6852         return base;
6853
6854       t = TREE_OPERAND (expr, 1);
6855       if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0)
6856         {
6857           code = MINUS_EXPR;
6858           t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t);
6859         }
6860       t = convert (sizetype, t);
6861       off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
6862       break;
6863
6864     case COMPOUND_EXPR:
6865       /* Handle static members of volatile structs.  */
6866       t = TREE_OPERAND (expr, 1);
6867       gcc_assert (TREE_CODE (t) == VAR_DECL);
6868       return fold_offsetof_1 (t, stop_ref);
6869
6870     default:
6871       gcc_unreachable ();
6872     }
6873
6874   return size_binop (code, base, off);
6875 }
6876
6877 tree
6878 fold_offsetof (tree expr, tree stop_ref)
6879 {
6880   /* Convert back from the internal sizetype to size_t.  */
6881   return convert (size_type_node, fold_offsetof_1 (expr, stop_ref));
6882 }
6883
6884 /* Print an error message for an invalid lvalue.  USE says
6885    how the lvalue is being used and so selects the error message.  */
6886
6887 void
6888 lvalue_error (enum lvalue_use use)
6889 {
6890   switch (use)
6891     {
6892     case lv_assign:
6893       error ("lvalue required as left operand of assignment");
6894       break;
6895     case lv_increment:
6896       error ("lvalue required as increment operand");
6897       break;
6898     case lv_decrement:
6899       error ("lvalue required as decrement operand");
6900       break;
6901     case lv_addressof:
6902       error ("lvalue required as unary %<&%> operand");
6903       break;
6904     case lv_asm:
6905       error ("lvalue required in asm statement");
6906       break;
6907     default:
6908       gcc_unreachable ();
6909     }
6910 }
6911 \f
6912 /* *PTYPE is an incomplete array.  Complete it with a domain based on
6913    INITIAL_VALUE.  If INITIAL_VALUE is not present, use 1 if DO_DEFAULT
6914    is true.  Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered,
6915    2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty.  */
6916
6917 int
6918 complete_array_type (tree *ptype, tree initial_value, bool do_default)
6919 {
6920   tree maxindex, type, main_type, elt, unqual_elt;
6921   int failure = 0, quals;
6922   hashval_t hashcode = 0;
6923
6924   maxindex = size_zero_node;
6925   if (initial_value)
6926     {
6927       if (TREE_CODE (initial_value) == STRING_CST)
6928         {
6929           int eltsize
6930             = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value)));
6931           maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1);
6932         }
6933       else if (TREE_CODE (initial_value) == CONSTRUCTOR)
6934         {
6935           VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (initial_value);
6936
6937           if (VEC_empty (constructor_elt, v))
6938             {
6939               if (pedantic)
6940                 failure = 3;
6941               maxindex = integer_minus_one_node;
6942             }
6943           else
6944             {
6945               tree curindex;
6946               unsigned HOST_WIDE_INT cnt;
6947               constructor_elt *ce;
6948
6949               if (VEC_index (constructor_elt, v, 0)->index)
6950                 maxindex = fold_convert (sizetype,
6951                                          VEC_index (constructor_elt,
6952                                                     v, 0)->index);
6953               curindex = maxindex;
6954
6955               for (cnt = 1;
6956                    VEC_iterate (constructor_elt, v, cnt, ce);
6957                    cnt++)
6958                 {
6959                   if (ce->index)
6960                     curindex = fold_convert (sizetype, ce->index);
6961                   else
6962                     curindex = size_binop (PLUS_EXPR, curindex, size_one_node);
6963
6964                   if (tree_int_cst_lt (maxindex, curindex))
6965                     maxindex = curindex;
6966                 }
6967             }
6968         }
6969       else
6970         {
6971           /* Make an error message unless that happened already.  */
6972           if (initial_value != error_mark_node)
6973             failure = 1;
6974         }
6975     }
6976   else
6977     {
6978       failure = 2;
6979       if (!do_default)
6980         return failure;
6981     }
6982
6983   type = *ptype;
6984   elt = TREE_TYPE (type);
6985   quals = TYPE_QUALS (strip_array_types (elt));
6986   if (quals == 0)
6987     unqual_elt = elt;
6988   else
6989     unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
6990
6991   /* Using build_distinct_type_copy and modifying things afterward instead
6992      of using build_array_type to create a new type preserves all of the
6993      TYPE_LANG_FLAG_? bits that the front end may have set.  */
6994   main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
6995   TREE_TYPE (main_type) = unqual_elt;
6996   TYPE_DOMAIN (main_type) = build_index_type (maxindex);
6997   layout_type (main_type);
6998
6999   /* Make sure we have the canonical MAIN_TYPE. */
7000   hashcode = iterative_hash_object (TYPE_HASH (unqual_elt), hashcode);
7001   hashcode = iterative_hash_object (TYPE_HASH (TYPE_DOMAIN (main_type)),
7002                                     hashcode);
7003   main_type = type_hash_canon (hashcode, main_type);
7004
7005   /* Fix the canonical type.  */
7006   if (TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (main_type))
7007       || TYPE_STRUCTURAL_EQUALITY_P (TYPE_DOMAIN (main_type)))
7008     SET_TYPE_STRUCTURAL_EQUALITY (main_type);
7009   else if (TYPE_CANONICAL (TREE_TYPE (main_type)) != TREE_TYPE (main_type)
7010            || (TYPE_CANONICAL (TYPE_DOMAIN (main_type))
7011                != TYPE_DOMAIN (main_type)))
7012     TYPE_CANONICAL (main_type)
7013       = build_array_type (TYPE_CANONICAL (TREE_TYPE (main_type)),
7014                           TYPE_CANONICAL (TYPE_DOMAIN (main_type)));
7015   else
7016     TYPE_CANONICAL (main_type) = main_type;
7017
7018   if (quals == 0)
7019     type = main_type;
7020   else
7021     type = c_build_qualified_type (main_type, quals);
7022
7023   if (COMPLETE_TYPE_P (type)
7024       && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST
7025       && TREE_OVERFLOW (TYPE_SIZE_UNIT (type)))
7026     {
7027       error ("size of array is too large");
7028       /* If we proceed with the array type as it is, we'll eventually
7029          crash in tree_low_cst().  */
7030       type = error_mark_node;
7031     }
7032
7033   *ptype = type;
7034   return failure;
7035 }
7036
7037 \f
7038 /* Used to help initialize the builtin-types.def table.  When a type of
7039    the correct size doesn't exist, use error_mark_node instead of NULL.
7040    The later results in segfaults even when a decl using the type doesn't
7041    get invoked.  */
7042
7043 tree
7044 builtin_type_for_size (int size, bool unsignedp)
7045 {
7046   tree type = lang_hooks.types.type_for_size (size, unsignedp);
7047   return type ? type : error_mark_node;
7048 }
7049
7050 /* A helper function for resolve_overloaded_builtin in resolving the
7051    overloaded __sync_ builtins.  Returns a positive power of 2 if the
7052    first operand of PARAMS is a pointer to a supported data type.
7053    Returns 0 if an error is encountered.  */
7054
7055 static int
7056 sync_resolve_size (tree function, tree params)
7057 {
7058   tree type;
7059   int size;
7060
7061   if (params == NULL)
7062     {
7063       error ("too few arguments to function %qE", function);
7064       return 0;
7065     }
7066
7067   type = TREE_TYPE (TREE_VALUE (params));
7068   if (TREE_CODE (type) != POINTER_TYPE)
7069     goto incompatible;
7070
7071   type = TREE_TYPE (type);
7072   if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
7073     goto incompatible;
7074
7075   size = tree_low_cst (TYPE_SIZE_UNIT (type), 1);
7076   if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16)
7077     return size;
7078
7079  incompatible:
7080   error ("incompatible type for argument %d of %qE", 1, function);
7081   return 0;
7082 }
7083
7084 /* A helper function for resolve_overloaded_builtin.  Adds casts to
7085    PARAMS to make arguments match up with those of FUNCTION.  Drops
7086    the variadic arguments at the end.  Returns false if some error
7087    was encountered; true on success.  */
7088
7089 static bool
7090 sync_resolve_params (tree orig_function, tree function, tree params)
7091 {
7092   tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (function));
7093   tree ptype;
7094   int number;
7095
7096   /* We've declared the implementation functions to use "volatile void *"
7097      as the pointer parameter, so we shouldn't get any complaints from the
7098      call to check_function_arguments what ever type the user used.  */
7099   arg_types = TREE_CHAIN (arg_types);
7100   ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params)));
7101   number = 2;
7102
7103   /* For the rest of the values, we need to cast these to FTYPE, so that we
7104      don't get warnings for passing pointer types, etc.  */
7105   while (arg_types != void_list_node)
7106     {
7107       tree val;
7108
7109       params = TREE_CHAIN (params);
7110       if (params == NULL)
7111         {
7112           error ("too few arguments to function %qE", orig_function);
7113           return false;
7114         }
7115
7116       /* ??? Ideally for the first conversion we'd use convert_for_assignment
7117          so that we get warnings for anything that doesn't match the pointer
7118          type.  This isn't portable across the C and C++ front ends atm.  */
7119       val = TREE_VALUE (params);
7120       val = convert (ptype, val);
7121       val = convert (TREE_VALUE (arg_types), val);
7122       TREE_VALUE (params) = val;
7123
7124       arg_types = TREE_CHAIN (arg_types);
7125       number++;
7126     }
7127
7128   /* The definition of these primitives is variadic, with the remaining
7129      being "an optional list of variables protected by the memory barrier".
7130      No clue what that's supposed to mean, precisely, but we consider all
7131      call-clobbered variables to be protected so we're safe.  */
7132   TREE_CHAIN (params) = NULL;
7133
7134   return true;
7135 }
7136
7137 /* A helper function for resolve_overloaded_builtin.  Adds a cast to
7138    RESULT to make it match the type of the first pointer argument in
7139    PARAMS.  */
7140
7141 static tree
7142 sync_resolve_return (tree params, tree result)
7143 {
7144   tree ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params)));
7145   ptype = TYPE_MAIN_VARIANT (ptype);
7146   return convert (ptype, result);
7147 }
7148
7149 /* Some builtin functions are placeholders for other expressions.  This
7150    function should be called immediately after parsing the call expression
7151    before surrounding code has committed to the type of the expression.
7152
7153    FUNCTION is the DECL that has been invoked; it is known to be a builtin.
7154    PARAMS is the argument list for the call.  The return value is non-null
7155    when expansion is complete, and null if normal processing should
7156    continue.  */
7157
7158 tree
7159 resolve_overloaded_builtin (tree function, tree params)
7160 {
7161   enum built_in_function orig_code = DECL_FUNCTION_CODE (function);
7162   switch (DECL_BUILT_IN_CLASS (function))
7163     {
7164     case BUILT_IN_NORMAL:
7165       break;
7166     case BUILT_IN_MD:
7167       if (targetm.resolve_overloaded_builtin)
7168         return targetm.resolve_overloaded_builtin (function, params);
7169       else
7170         return NULL_TREE;
7171     default:
7172       return NULL_TREE;
7173     }
7174
7175   /* Handle BUILT_IN_NORMAL here.  */
7176   switch (orig_code)
7177     {
7178     case BUILT_IN_FETCH_AND_ADD_N:
7179     case BUILT_IN_FETCH_AND_SUB_N:
7180     case BUILT_IN_FETCH_AND_OR_N:
7181     case BUILT_IN_FETCH_AND_AND_N:
7182     case BUILT_IN_FETCH_AND_XOR_N:
7183     case BUILT_IN_FETCH_AND_NAND_N:
7184     case BUILT_IN_ADD_AND_FETCH_N:
7185     case BUILT_IN_SUB_AND_FETCH_N:
7186     case BUILT_IN_OR_AND_FETCH_N:
7187     case BUILT_IN_AND_AND_FETCH_N:
7188     case BUILT_IN_XOR_AND_FETCH_N:
7189     case BUILT_IN_NAND_AND_FETCH_N:
7190     case BUILT_IN_BOOL_COMPARE_AND_SWAP_N:
7191     case BUILT_IN_VAL_COMPARE_AND_SWAP_N:
7192     case BUILT_IN_LOCK_TEST_AND_SET_N:
7193     case BUILT_IN_LOCK_RELEASE_N:
7194       {
7195         int n = sync_resolve_size (function, params);
7196         tree new_function, result;
7197
7198         if (n == 0)
7199           return error_mark_node;
7200
7201         new_function = built_in_decls[orig_code + exact_log2 (n) + 1];
7202         if (!sync_resolve_params (function, new_function, params))
7203           return error_mark_node;
7204
7205         result = build_function_call (new_function, params);
7206         if (orig_code != BUILT_IN_BOOL_COMPARE_AND_SWAP_N
7207             && orig_code != BUILT_IN_LOCK_RELEASE_N)
7208           result = sync_resolve_return (params, result);
7209
7210         return result;
7211       }
7212
7213     default:
7214       return NULL_TREE;
7215     }
7216 }
7217
7218 /* Ignoring their sign, return true if two scalar types are the same.  */
7219 bool
7220 same_scalar_type_ignoring_signedness (tree t1, tree t2)
7221 {
7222   enum tree_code c1 = TREE_CODE (t1), c2 = TREE_CODE (t2);
7223
7224   gcc_assert ((c1 == INTEGER_TYPE || c1 == REAL_TYPE || c1 == FIXED_POINT_TYPE)
7225               && (c2 == INTEGER_TYPE || c2 == REAL_TYPE
7226                   || c2 == FIXED_POINT_TYPE));
7227
7228   /* Equality works here because c_common_signed_type uses
7229      TYPE_MAIN_VARIANT.  */
7230   return c_common_signed_type (t1)
7231     == c_common_signed_type (t2);
7232 }
7233
7234 /* Check for missing format attributes on function pointers.  LTYPE is
7235    the new type or left-hand side type.  RTYPE is the old type or
7236    right-hand side type.  Returns TRUE if LTYPE is missing the desired
7237    attribute.  */
7238
7239 bool
7240 check_missing_format_attribute (tree ltype, tree rtype)
7241 {
7242   tree const ttr = TREE_TYPE (rtype), ttl = TREE_TYPE (ltype);
7243   tree ra;
7244
7245   for (ra = TYPE_ATTRIBUTES (ttr); ra; ra = TREE_CHAIN (ra))
7246     if (is_attribute_p ("format", TREE_PURPOSE (ra)))
7247       break;
7248   if (ra)
7249     {
7250       tree la;
7251       for (la = TYPE_ATTRIBUTES (ttl); la; la = TREE_CHAIN (la))
7252         if (is_attribute_p ("format", TREE_PURPOSE (la)))
7253           break;
7254       return !la;
7255     }
7256   else
7257     return false;
7258 }
7259
7260 /* Subscripting with type char is likely to lose on a machine where
7261    chars are signed.  So warn on any machine, but optionally.  Don't
7262    warn for unsigned char since that type is safe.  Don't warn for
7263    signed char because anyone who uses that must have done so
7264    deliberately. Furthermore, we reduce the false positive load by
7265    warning only for non-constant value of type char.  */
7266
7267 void
7268 warn_array_subscript_with_type_char (tree index)
7269 {
7270   if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node
7271       && TREE_CODE (index) != INTEGER_CST)
7272     warning (OPT_Wchar_subscripts, "array subscript has type %<char%>");
7273 }
7274
7275 /* Implement -Wparentheses for the unexpected C precedence rules, to
7276    cover cases like x + y << z which readers are likely to
7277    misinterpret.  We have seen an expression in which CODE is a binary
7278    operator used to combine expressions headed by CODE_LEFT and
7279    CODE_RIGHT.  CODE_LEFT and CODE_RIGHT may be ERROR_MARK, which
7280    means that that side of the expression was not formed using a
7281    binary operator, or it was enclosed in parentheses.  */
7282
7283 void
7284 warn_about_parentheses (enum tree_code code, enum tree_code code_left,
7285                         enum tree_code code_right)
7286 {
7287   if (!warn_parentheses)
7288     return;
7289
7290   if (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
7291     {
7292       if (code_left == PLUS_EXPR || code_left == MINUS_EXPR
7293           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7294         warning (OPT_Wparentheses,
7295                  "suggest parentheses around + or - inside shift");
7296     }
7297
7298   if (code == TRUTH_ORIF_EXPR)
7299     {
7300       if (code_left == TRUTH_ANDIF_EXPR
7301           || code_right == TRUTH_ANDIF_EXPR)
7302         warning (OPT_Wparentheses,
7303                  "suggest parentheses around && within ||");
7304     }
7305
7306   if (code == BIT_IOR_EXPR)
7307     {
7308       if (code_left == BIT_AND_EXPR || code_left == BIT_XOR_EXPR
7309           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
7310           || code_right == BIT_AND_EXPR || code_right == BIT_XOR_EXPR
7311           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7312         warning (OPT_Wparentheses,
7313                  "suggest parentheses around arithmetic in operand of |");
7314       /* Check cases like x|y==z */
7315       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7316           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7317         warning (OPT_Wparentheses,
7318                  "suggest parentheses around comparison in operand of |");
7319     }
7320
7321   if (code == BIT_XOR_EXPR)
7322     {
7323       if (code_left == BIT_AND_EXPR
7324           || code_left == PLUS_EXPR || code_left == MINUS_EXPR
7325           || code_right == BIT_AND_EXPR
7326           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7327         warning (OPT_Wparentheses,
7328                  "suggest parentheses around arithmetic in operand of ^");
7329       /* Check cases like x^y==z */
7330       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7331           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7332         warning (OPT_Wparentheses,
7333                  "suggest parentheses around comparison in operand of ^");
7334     }
7335
7336   if (code == BIT_AND_EXPR)
7337     {
7338       if (code_left == PLUS_EXPR || code_left == MINUS_EXPR
7339           || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
7340         warning (OPT_Wparentheses,
7341                  "suggest parentheses around + or - in operand of &");
7342       /* Check cases like x&y==z */
7343       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7344           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7345         warning (OPT_Wparentheses,
7346                  "suggest parentheses around comparison in operand of &");
7347     }
7348
7349   if (code == EQ_EXPR || code == NE_EXPR)
7350     {
7351       if (TREE_CODE_CLASS (code_left) == tcc_comparison
7352           || TREE_CODE_CLASS (code_right) == tcc_comparison)
7353         warning (OPT_Wparentheses,
7354                  "suggest parentheses around comparison in operand of %s",
7355                  code == EQ_EXPR ? "==" : "!=");
7356     }
7357   else if (TREE_CODE_CLASS (code) == tcc_comparison)
7358     {
7359       if ((TREE_CODE_CLASS (code_left) == tcc_comparison
7360            && code_left != NE_EXPR && code_left != EQ_EXPR)
7361           || (TREE_CODE_CLASS (code_right) == tcc_comparison
7362               && code_right != NE_EXPR && code_right != EQ_EXPR))
7363         warning (OPT_Wparentheses, "comparisons like X<=Y<=Z do not "
7364                  "have their mathematical meaning");
7365     }
7366 }
7367
7368 /* If LABEL (a LABEL_DECL) has not been used, issue a warning.  */
7369
7370 void
7371 warn_for_unused_label (tree label)
7372 {
7373   if (!TREE_USED (label))
7374     {
7375       if (DECL_INITIAL (label))
7376         warning (OPT_Wunused_label, "label %q+D defined but not used", label);
7377       else
7378         warning (OPT_Wunused_label, "label %q+D declared but not defined", label);
7379     }
7380 }
7381
7382 #ifndef TARGET_HAS_TARGETCM
7383 struct gcc_targetcm targetcm = TARGETCM_INITIALIZER;
7384 #endif
7385
7386 /* Warn for division by zero according to the value of DIVISOR.  */
7387
7388 void
7389 warn_for_div_by_zero (tree divisor)
7390 {
7391   /* If DIVISOR is zero, and has integral or fixed-point type, issue a warning
7392      about division by zero.  Do not issue a warning if DIVISOR has a
7393      floating-point type, since we consider 0.0/0.0 a valid way of
7394      generating a NaN.  */
7395   if (skip_evaluation == 0
7396       && (integer_zerop (divisor) || fixed_zerop (divisor)))
7397     warning (OPT_Wdiv_by_zero, "division by zero");
7398 }
7399
7400 #include "gt-c-common.h"