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 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 2, 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 COPYING.  If not, write to the Free
  19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
  20 02110-1301, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "intl.h"
  27 #include "tree.h"
  28 #include "flags.h"
  29 #include "output.h"
  30 #include "c-pragma.h"
  31 #include "rtl.h"
  32 #include "ggc.h"
  33 #include "varray.h"
  34 #include "expr.h"
  35 #include "c-common.h"
  36 #include "diagnostic.h"
  37 #include "tm_p.h"
  38 #include "obstack.h"
  39 #include "cpplib.h"
  40 #include "target.h"
  41 #include "langhooks.h"
  42 #include "tree-inline.h"
  43 #include "c-tree.h"
  44 #include "toplev.h"
  45 #include "tree-iterator.h"
  46 #include "hashtab.h"
  47 #include "tree-mudflap.h"
  48 #include "opts.h"
  49 #include "real.h"
  50 #include "cgraph.h"
  51
  52 cpp_reader *parse_in;           /* Declared in c-pragma.h.  */
  53
  54 /* We let tm.h override the types used here, to handle trivial differences
  55    such as the choice of unsigned int or long unsigned int for size_t.
  56    When machines start needing nontrivial differences in the size type,
  57    it would be best to do something here to figure out automatically
  58    from other information what type to use.  */
  59
  60 #ifndef SIZE_TYPE
  61 #define SIZE_TYPE "long unsigned int"
  62 #endif
  63
  64 #ifndef PID_TYPE
  65 #define PID_TYPE "int"
  66 #endif
  67
  68 #ifndef WCHAR_TYPE
  69 #define WCHAR_TYPE "int"
  70 #endif
  71
  72 /* WCHAR_TYPE gets overridden by -fshort-wchar.  */
  73 #define MODIFIED_WCHAR_TYPE \
  74         (flag_short_wchar ? "short unsigned int" : WCHAR_TYPE)
  75
  76 #ifndef PTRDIFF_TYPE
  77 #define PTRDIFF_TYPE "long int"
  78 #endif
  79
  80 #ifndef WINT_TYPE
  81 #define WINT_TYPE "unsigned int"
  82 #endif
  83
  84 #ifndef INTMAX_TYPE
  85 #define INTMAX_TYPE ((INT_TYPE_SIZE == LONG_LONG_TYPE_SIZE)     \
  86                      ? "int"                                    \
  87                      : ((LONG_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \
  88                         ? "long int"                            \
  89                         : "long long int"))
  90 #endif
  91
  92 #ifndef UINTMAX_TYPE
  93 #define UINTMAX_TYPE ((INT_TYPE_SIZE == LONG_LONG_TYPE_SIZE)    \
  94                      ? "unsigned int"                           \
  95                      : ((LONG_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \
  96                         ? "long unsigned int"                   \
  97                         : "long long unsigned int"))
  98 #endif
  99
 100 /* The following symbols are subsumed in the c_global_trees array, and
 101    listed here individually for documentation purposes.
 102
 103    INTEGER_TYPE and REAL_TYPE nodes for the standard data types.
 104
 105         tree short_integer_type_node;
 106         tree long_integer_type_node;
 107         tree long_long_integer_type_node;
 108
 109         tree short_unsigned_type_node;
 110         tree long_unsigned_type_node;
 111         tree long_long_unsigned_type_node;
 112
 113         tree truthvalue_type_node;
 114         tree truthvalue_false_node;
 115         tree truthvalue_true_node;
 116
 117         tree ptrdiff_type_node;
 118
 119         tree unsigned_char_type_node;
 120         tree signed_char_type_node;
 121         tree wchar_type_node;
 122         tree signed_wchar_type_node;
 123         tree unsigned_wchar_type_node;
 124
 125         tree float_type_node;
 126         tree double_type_node;
 127         tree long_double_type_node;
 128
 129         tree complex_integer_type_node;
 130         tree complex_float_type_node;
 131         tree complex_double_type_node;
 132         tree complex_long_double_type_node;
 133
 134         tree dfloat32_type_node;
 135         tree dfloat64_type_node;
 136         tree_dfloat128_type_node;
 137
 138         tree intQI_type_node;
 139         tree intHI_type_node;
 140         tree intSI_type_node;
 141         tree intDI_type_node;
 142         tree intTI_type_node;
 143
 144         tree unsigned_intQI_type_node;
 145         tree unsigned_intHI_type_node;
 146         tree unsigned_intSI_type_node;
 147         tree unsigned_intDI_type_node;
 148         tree unsigned_intTI_type_node;
 149
 150         tree widest_integer_literal_type_node;
 151         tree widest_unsigned_literal_type_node;
 152
 153    Nodes for types `void *' and `const void *'.
 154
 155         tree ptr_type_node, const_ptr_type_node;
 156
 157    Nodes for types `char *' and `const char *'.
 158
 159         tree string_type_node, const_string_type_node;
 160
 161    Type `char[SOMENUMBER]'.
 162    Used when an array of char is needed and the size is irrelevant.
 163
 164         tree char_array_type_node;
 165
 166    Type `int[SOMENUMBER]' or something like it.
 167    Used when an array of int needed and the size is irrelevant.
 168
 169         tree int_array_type_node;
 170
 171    Type `wchar_t[SOMENUMBER]' or something like it.
 172    Used when a wide string literal is created.
 173
 174         tree wchar_array_type_node;
 175
 176    Type `int ()' -- used for implicit declaration of functions.
 177
 178         tree default_function_type;
 179
 180    A VOID_TYPE node, packaged in a TREE_LIST.
 181
 182         tree void_list_node;
 183
 184   The lazily created VAR_DECLs for __FUNCTION__, __PRETTY_FUNCTION__,
 185   and __func__. (C doesn't generate __FUNCTION__ and__PRETTY_FUNCTION__
 186   VAR_DECLS, but C++ does.)
 187
 188         tree function_name_decl_node;
 189         tree pretty_function_name_decl_node;
 190         tree c99_function_name_decl_node;
 191
 192   Stack of nested function name VAR_DECLs.
 193
 194         tree saved_function_name_decls;
 195
 196 */
 197
 198 tree c_global_trees[CTI_MAX];
 199 \f
 200 /* Switches common to the C front ends.  */
 201
 202 /* Nonzero if prepreprocessing only.  */
 203
 204 int flag_preprocess_only;
 205
 206 /* Nonzero means don't output line number information.  */
 207
 208 char flag_no_line_commands;
 209
 210 /* Nonzero causes -E output not to be done, but directives such as
 211    #define that have side effects are still obeyed.  */
 212
 213 char flag_no_output;
 214
 215 /* Nonzero means dump macros in some fashion.  */
 216
 217 char flag_dump_macros;
 218
 219 /* Nonzero means pass #include lines through to the output.  */
 220
 221 char flag_dump_includes;
 222
 223 /* Nonzero means process PCH files while preprocessing.  */
 224
 225 bool flag_pch_preprocess;
 226
 227 /* The file name to which we should write a precompiled header, or
 228    NULL if no header will be written in this compile.  */
 229
 230 const char *pch_file;
 231
 232 /* Nonzero if an ISO standard was selected.  It rejects macros in the
 233    user's namespace.  */
 234 int flag_iso;
 235
 236 /* Nonzero if -undef was given.  It suppresses target built-in macros
 237    and assertions.  */
 238 int flag_undef;
 239
 240 /* Nonzero means don't recognize the non-ANSI builtin functions.  */
 241
 242 int flag_no_builtin;
 243
 244 /* Nonzero means don't recognize the non-ANSI builtin functions.
 245    -ansi sets this.  */
 246
 247 int flag_no_nonansi_builtin;
 248
 249 /* Nonzero means give `double' the same size as `float'.  */
 250
 251 int flag_short_double;
 252
 253 /* Nonzero means give `wchar_t' the same size as `short'.  */
 254
 255 int flag_short_wchar;
 256
 257 /* Nonzero means allow Microsoft extensions without warnings or errors.  */
 258 int flag_ms_extensions;
 259
 260 /* Nonzero means don't recognize the keyword `asm'.  */
 261
 262 int flag_no_asm;
 263
 264 /* Nonzero means to treat bitfields as signed unless they say `unsigned'.  */
 265
 266 int flag_signed_bitfields = 1;
 267
 268 /* Warn about #pragma directives that are not recognized.  */
 269
 270 int warn_unknown_pragmas; /* Tri state variable.  */
 271
 272 /* Warn about format/argument anomalies in calls to formatted I/O functions
 273    (*printf, *scanf, strftime, strfmon, etc.).  */
 274
 275 int warn_format;
 276
 277 /* Warn about using __null (as NULL in C++) as sentinel.  For code compiled
 278    with GCC this doesn't matter as __null is guaranteed to have the right
 279    size.  */
 280
 281 int warn_strict_null_sentinel;
 282
 283 /* Zero means that faster, ...NonNil variants of objc_msgSend...
 284    calls will be used in ObjC; passing nil receivers to such calls
 285    will most likely result in crashes.  */
 286 int flag_nil_receivers = 1;
 287
 288 /* Nonzero means that code generation will be altered to support
 289    "zero-link" execution.  This currently affects ObjC only, but may
 290    affect other languages in the future.  */
 291 int flag_zero_link = 0;
 292
 293 /* Nonzero means emit an '__OBJC, __image_info' for the current translation
 294    unit.  It will inform the ObjC runtime that class definition(s) herein
 295    contained are to replace one(s) previously loaded.  */
 296 int flag_replace_objc_classes = 0;
 297
 298 /* C/ObjC language option variables.  */
 299
 300
 301 /* Nonzero means allow type mismatches in conditional expressions;
 302    just make their values `void'.  */
 303
 304 int flag_cond_mismatch;
 305
 306 /* Nonzero means enable C89 Amendment 1 features.  */
 307
 308 int flag_isoc94;
 309
 310 /* Nonzero means use the ISO C99 dialect of C.  */
 311
 312 int flag_isoc99;
 313
 314 /* Nonzero means that we have builtin functions, and main is an int.  */
 315
 316 int flag_hosted = 1;
 317
 318 /* Warn if main is suspicious.  */
 319
 320 int warn_main;
 321
 322
 323 /* ObjC language option variables.  */
 324
 325
 326 /* Open and close the file for outputting class declarations, if
 327    requested (ObjC).  */
 328
 329 int flag_gen_declaration;
 330
 331 /* Tells the compiler that this is a special run.  Do not perform any
 332    compiling, instead we are to test some platform dependent features
 333    and output a C header file with appropriate definitions.  */
 334
 335 int print_struct_values;
 336
 337 /* Tells the compiler what is the constant string class for Objc.  */
 338
 339 const char *constant_string_class_name;
 340
 341
 342 /* C++ language option variables.  */
 343
 344
 345 /* Nonzero means don't recognize any extension keywords.  */
 346
 347 int flag_no_gnu_keywords;
 348
 349 /* Nonzero means do emit exported implementations of functions even if
 350    they can be inlined.  */
 351
 352 int flag_implement_inlines = 1;
 353
 354 /* Nonzero means that implicit instantiations will be emitted if needed.  */
 355
 356 int flag_implicit_templates = 1;
 357
 358 /* Nonzero means that implicit instantiations of inline templates will be
 359    emitted if needed, even if instantiations of non-inline templates
 360    aren't.  */
 361
 362 int flag_implicit_inline_templates = 1;
 363
 364 /* Nonzero means generate separate instantiation control files and
 365    juggle them at link time.  */
 366
 367 int flag_use_repository;
 368
 369 /* Nonzero if we want to issue diagnostics that the standard says are not
 370    required.  */
 371
 372 int flag_optional_diags = 1;
 373
 374 /* Nonzero means we should attempt to elide constructors when possible.  */
 375
 376 int flag_elide_constructors = 1;
 377
 378 /* Nonzero means that member functions defined in class scope are
 379    inline by default.  */
 380
 381 int flag_default_inline = 1;
 382
 383 /* Controls whether compiler generates 'type descriptor' that give
 384    run-time type information.  */
 385
 386 int flag_rtti = 1;
 387
 388 /* Nonzero if we want to conserve space in the .o files.  We do this
 389    by putting uninitialized data and runtime initialized data into
 390    .common instead of .data at the expense of not flagging multiple
 391    definitions.  */
 392
 393 int flag_conserve_space;
 394
 395 /* Nonzero if we want to obey access control semantics.  */
 396
 397 int flag_access_control = 1;
 398
 399 /* Nonzero if we want to check the return value of new and avoid calling
 400    constructors if it is a null pointer.  */
 401
 402 int flag_check_new;
 403
 404 /* Nonzero if we want the new ISO rules for pushing a new scope for `for'
 405    initialization variables.
 406    0: Old rules, set by -fno-for-scope.
 407    2: New ISO rules, set by -ffor-scope.
 408    1: Try to implement new ISO rules, but with backup compatibility
 409    (and warnings).  This is the default, for now.  */
 410
 411 int flag_new_for_scope = 1;
 412
 413 /* Nonzero if we want to emit defined symbols with common-like linkage as
 414    weak symbols where possible, in order to conform to C++ semantics.
 415    Otherwise, emit them as local symbols.  */
 416
 417 int flag_weak = 1;
 418
 419 /* 0 means we want the preprocessor to not emit line directives for
 420    the current working directory.  1 means we want it to do it.  -1
 421    means we should decide depending on whether debugging information
 422    is being emitted or not.  */
 423
 424 int flag_working_directory = -1;
 425
 426 /* Nonzero to use __cxa_atexit, rather than atexit, to register
 427    destructors for local statics and global objects.  '2' means it has been
 428    set nonzero as a default, not by a command-line flag.  */
 429
 430 int flag_use_cxa_atexit = DEFAULT_USE_CXA_ATEXIT;
 431
 432 /* Nonzero to use __cxa_get_exception_ptr in C++ exception-handling
 433    code.  '2' means it has not been set explicitly on the command line.  */
 434
 435 int flag_use_cxa_get_exception_ptr = 2;
 436
 437 /* Nonzero means make the default pedwarns warnings instead of errors.
 438    The value of this flag is ignored if -pedantic is specified.  */
 439
 440 int flag_permissive;
 441
 442 /* Nonzero means to implement standard semantics for exception
 443    specifications, calling unexpected if an exception is thrown that
 444    doesn't match the specification.  Zero means to treat them as
 445    assertions and optimize accordingly, but not check them.  */
 446
 447 int flag_enforce_eh_specs = 1;
 448
 449 /* Nonzero means to generate thread-safe code for initializing local
 450    statics.  */
 451
 452 int flag_threadsafe_statics = 1;
 453
 454 /* Nonzero means warn about implicit declarations.  */
 455
 456 int warn_implicit = 1;
 457
 458 /* Maximum template instantiation depth.  This limit is rather
 459    arbitrary, but it exists to limit the time it takes to notice
 460    infinite template instantiations.  */
 461
 462 int max_tinst_depth = 500;
 463
 464
 465
 466 /* The elements of `ridpointers' are identifier nodes for the reserved
 467    type names and storage classes.  It is indexed by a RID_... value.  */
 468 tree *ridpointers;
 469
 470 tree (*make_fname_decl) (tree, int);
 471
 472 /* Nonzero means the expression being parsed will never be evaluated.
 473    This is a count, since unevaluated expressions can nest.  */
 474 int skip_evaluation;
 475
 476 /* Information about how a function name is generated.  */
 477 struct fname_var_t
 478 {
 479   tree *const decl;     /* pointer to the VAR_DECL.  */
 480   const unsigned rid;   /* RID number for the identifier.  */
 481   const int pretty;     /* How pretty is it? */
 482 };
 483
 484 /* The three ways of getting then name of the current function.  */
 485
 486 const struct fname_var_t fname_vars[] =
 487 {
 488   /* C99 compliant __func__, must be first.  */
 489   {&c99_function_name_decl_node, RID_C99_FUNCTION_NAME, 0},
 490   /* GCC __FUNCTION__ compliant.  */
 491   {&function_name_decl_node, RID_FUNCTION_NAME, 0},
 492   /* GCC __PRETTY_FUNCTION__ compliant.  */
 493   {&pretty_function_name_decl_node, RID_PRETTY_FUNCTION_NAME, 1},
 494   {NULL, 0, 0},
 495 };
 496
 497 static int constant_fits_type_p (tree, tree);
 498 static tree check_case_value (tree);
 499 static bool check_case_bounds (tree, tree, tree *, tree *);
 500
 501 static tree handle_packed_attribute (tree *, tree, tree, int, bool *);
 502 static tree handle_nocommon_attribute (tree *, tree, tree, int, bool *);
 503 static tree handle_common_attribute (tree *, tree, tree, int, bool *);
 504 static tree handle_noreturn_attribute (tree *, tree, tree, int, bool *);
 505 static tree handle_noinline_attribute (tree *, tree, tree, int, bool *);
 506 static tree handle_always_inline_attribute (tree *, tree, tree, int,
 507                                             bool *);
 508 static tree handle_flatten_attribute (tree *, tree, tree, int, bool *);
 509 static tree handle_used_attribute (tree *, tree, tree, int, bool *);
 510 static tree handle_unused_attribute (tree *, tree, tree, int, bool *);
 511 static tree handle_externally_visible_attribute (tree *, tree, tree, int,
 512                                                  bool *);
 513 static tree handle_const_attribute (tree *, tree, tree, int, bool *);
 514 static tree handle_transparent_union_attribute (tree *, tree, tree,
 515                                                 int, bool *);
 516 static tree handle_constructor_attribute (tree *, tree, tree, int, bool *);
 517 static tree handle_destructor_attribute (tree *, tree, tree, int, bool *);
 518 static tree handle_mode_attribute (tree *, tree, tree, int, bool *);
 519 static tree handle_section_attribute (tree *, tree, tree, int, bool *);
 520 static tree handle_aligned_attribute (tree *, tree, tree, int, bool *);
 521 static tree handle_weak_attribute (tree *, tree, tree, int, bool *) ;
 522 static tree handle_alias_attribute (tree *, tree, tree, int, bool *);
 523 static tree handle_weakref_attribute (tree *, tree, tree, int, bool *) ;
 524 static tree handle_visibility_attribute (tree *, tree, tree, int,
 525                                          bool *);
 526 static tree handle_tls_model_attribute (tree *, tree, tree, int,
 527                                         bool *);
 528 static tree handle_no_instrument_function_attribute (tree *, tree,
 529                                                      tree, int, bool *);
 530 static tree handle_malloc_attribute (tree *, tree, tree, int, bool *);
 531 static tree handle_returns_twice_attribute (tree *, tree, tree, int, bool *);
 532 static tree handle_no_limit_stack_attribute (tree *, tree, tree, int,
 533                                              bool *);
 534 static tree handle_pure_attribute (tree *, tree, tree, int, bool *);
 535 static tree handle_novops_attribute (tree *, tree, tree, int, bool *);
 536 static tree handle_deprecated_attribute (tree *, tree, tree, int,
 537                                          bool *);
 538 static tree handle_vector_size_attribute (tree *, tree, tree, int,
 539                                           bool *);
 540 static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *);
 541 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
 542 static tree handle_cleanup_attribute (tree *, tree, tree, int, bool *);
 543 static tree handle_warn_unused_result_attribute (tree *, tree, tree, int,
 544                                                  bool *);
 545 static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *);
 546
 547 static void check_function_nonnull (tree, tree);
 548 static void check_nonnull_arg (void *, tree, unsigned HOST_WIDE_INT);
 549 static bool nonnull_check_p (tree, unsigned HOST_WIDE_INT);
 550 static bool get_nonnull_operand (tree, unsigned HOST_WIDE_INT *);
 551 static int resort_field_decl_cmp (const void *, const void *);
 552
 553 /* Table of machine-independent attributes common to all C-like languages.  */
 554 const struct attribute_spec c_common_attribute_table[] =
 555 {
 556   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 557   { "packed",                 0, 0, false, false, false,
 558                               handle_packed_attribute },
 559   { "nocommon",               0, 0, true,  false, false,
 560                               handle_nocommon_attribute },
 561   { "common",                 0, 0, true,  false, false,
 562                               handle_common_attribute },
 563   /* FIXME: logically, noreturn attributes should be listed as
 564      "false, true, true" and apply to function types.  But implementing this
 565      would require all the places in the compiler that use TREE_THIS_VOLATILE
 566      on a decl to identify non-returning functions to be located and fixed
 567      to check the function type instead.  */
 568   { "noreturn",               0, 0, true,  false, false,
 569                               handle_noreturn_attribute },
 570   { "volatile",               0, 0, true,  false, false,
 571                               handle_noreturn_attribute },
 572   { "noinline",               0, 0, true,  false, false,
 573                               handle_noinline_attribute },
 574   { "always_inline",          0, 0, true,  false, false,
 575                               handle_always_inline_attribute },
 576   { "flatten",                0, 0, true,  false, false,
 577                               handle_flatten_attribute },
 578   { "used",                   0, 0, true,  false, false,
 579                               handle_used_attribute },
 580   { "unused",                 0, 0, false, false, false,
 581                               handle_unused_attribute },
 582   { "externally_visible",     0, 0, true,  false, false,
 583                               handle_externally_visible_attribute },
 584   /* The same comments as for noreturn attributes apply to const ones.  */
 585   { "const",                  0, 0, true,  false, false,
 586                               handle_const_attribute },
 587   { "transparent_union",      0, 0, false, false, false,
 588                               handle_transparent_union_attribute },
 589   { "constructor",            0, 0, true,  false, false,
 590                               handle_constructor_attribute },
 591   { "destructor",             0, 0, true,  false, false,
 592                               handle_destructor_attribute },
 593   { "mode",                   1, 1, false,  true, false,
 594                               handle_mode_attribute },
 595   { "section",                1, 1, true,  false, false,
 596                               handle_section_attribute },
 597   { "aligned",                0, 1, false, false, false,
 598                               handle_aligned_attribute },
 599   { "weak",                   0, 0, true,  false, false,
 600                               handle_weak_attribute },
 601   { "alias",                  1, 1, true,  false, false,
 602                               handle_alias_attribute },
 603   { "weakref",                0, 1, true,  false, false,
 604                               handle_weakref_attribute },
 605   { "no_instrument_function", 0, 0, true,  false, false,
 606                               handle_no_instrument_function_attribute },
 607   { "malloc",                 0, 0, true,  false, false,
 608                               handle_malloc_attribute },
 609   { "returns_twice",          0, 0, true,  false, false,
 610                               handle_returns_twice_attribute },
 611   { "no_stack_limit",         0, 0, true,  false, false,
 612                               handle_no_limit_stack_attribute },
 613   { "pure",                   0, 0, true,  false, false,
 614                               handle_pure_attribute },
 615   /* For internal use (marking of builtins) only.  The name contains space
 616      to prevent its usage in source code.  */
 617   { "no vops",                0, 0, true,  false, false,
 618                               handle_novops_attribute },
 619   { "deprecated",             0, 0, false, false, false,
 620                               handle_deprecated_attribute },
 621   { "vector_size",            1, 1, false, true, false,
 622                               handle_vector_size_attribute },
 623   { "visibility",             1, 1, false, false, false,
 624                               handle_visibility_attribute },
 625   { "tls_model",              1, 1, true,  false, false,
 626                               handle_tls_model_attribute },
 627   { "nonnull",                0, -1, false, true, true,
 628                               handle_nonnull_attribute },
 629   { "nothrow",                0, 0, true,  false, false,
 630                               handle_nothrow_attribute },
 631   { "may_alias",              0, 0, false, true, false, NULL },
 632   { "cleanup",                1, 1, true, false, false,
 633                               handle_cleanup_attribute },
 634   { "warn_unused_result",     0, 0, false, true, true,
 635                               handle_warn_unused_result_attribute },
 636   { "sentinel",               0, 1, false, true, true,
 637                               handle_sentinel_attribute },
 638   { NULL,                     0, 0, false, false, false, NULL }
 639 };
 640
 641 /* Give the specifications for the format attributes, used by C and all
 642    descendants.  */
 643
 644 const struct attribute_spec c_common_format_attribute_table[] =
 645 {
 646   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
 647   { "format",                 3, 3, false, true,  true,
 648                               handle_format_attribute },
 649   { "format_arg",             1, 1, false, true,  true,
 650                               handle_format_arg_attribute },
 651   { NULL,                     0, 0, false, false, false, NULL }
 652 };
 653
 654 /* Push current bindings for the function name VAR_DECLS.  */
 655
 656 void
 657 start_fname_decls (void)
 658 {
 659   unsigned ix;
 660   tree saved = NULL_TREE;
 661
 662   for (ix = 0; fname_vars[ix].decl; ix++)
 663     {
 664       tree decl = *fname_vars[ix].decl;
 665
 666       if (decl)
 667         {
 668           saved = tree_cons (decl, build_int_cst (NULL_TREE, ix), saved);
 669           *fname_vars[ix].decl = NULL_TREE;
 670         }
 671     }
 672   if (saved || saved_function_name_decls)
 673     /* Normally they'll have been NULL, so only push if we've got a
 674        stack, or they are non-NULL.  */
 675     saved_function_name_decls = tree_cons (saved, NULL_TREE,
 676                                            saved_function_name_decls);
 677 }
 678
 679 /* Finish up the current bindings, adding them into the current function's
 680    statement tree.  This must be done _before_ finish_stmt_tree is called.
 681    If there is no current function, we must be at file scope and no statements
 682    are involved. Pop the previous bindings.  */
 683
 684 void
 685 finish_fname_decls (void)
 686 {
 687   unsigned ix;
 688   tree stmts = NULL_TREE;
 689   tree stack = saved_function_name_decls;
 690
 691   for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack))
 692     append_to_statement_list (TREE_VALUE (stack), &stmts);
 693
 694   if (stmts)
 695     {
 696       tree *bodyp = &DECL_SAVED_TREE (current_function_decl);
 697
 698       if (TREE_CODE (*bodyp) == BIND_EXPR)
 699         bodyp = &BIND_EXPR_BODY (*bodyp);
 700
 701       append_to_statement_list_force (*bodyp, &stmts);
 702       *bodyp = stmts;
 703     }
 704
 705   for (ix = 0; fname_vars[ix].decl; ix++)
 706     *fname_vars[ix].decl = NULL_TREE;
 707
 708   if (stack)
 709     {
 710       /* We had saved values, restore them.  */
 711       tree saved;
 712
 713       for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved))
 714         {
 715           tree decl = TREE_PURPOSE (saved);
 716           unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved));
 717
 718           *fname_vars[ix].decl = decl;
 719         }
 720       stack = TREE_CHAIN (stack);
 721     }
 722   saved_function_name_decls = stack;
 723 }
 724
 725 /* Return the text name of the current function, suitably prettified
 726    by PRETTY_P.  Return string must be freed by caller.  */
 727
 728 const char *
 729 fname_as_string (int pretty_p)
 730 {
 731   const char *name = "top level";
 732   char *namep;
 733   int vrb = 2;
 734
 735   if (!pretty_p)
 736     {
 737       name = "";
 738       vrb = 0;
 739     }
 740
 741   if (current_function_decl)
 742     name = lang_hooks.decl_printable_name (current_function_decl, vrb);
 743
 744   if (c_lex_string_translate)
 745     {
 746       int len = strlen (name) + 3; /* Two for '"'s.  One for NULL.  */
 747       cpp_string cstr = { 0, 0 }, strname;
 748
 749       namep = XNEWVEC (char, len);
 750       snprintf (namep, len, "\"%s\"", name);
 751       strname.text = (unsigned char *) namep;
 752       strname.len = len - 1;
 753
 754       if (cpp_interpret_string (parse_in, &strname, 1, &cstr, false))
 755         {
 756           XDELETEVEC (namep);
 757           return (char *) cstr.text;
 758         }
 759     }
 760   else
 761     namep = xstrdup (name);
 762
 763   return namep;
 764 }
 765
 766 /* Expand DECL if it declares an entity not handled by the
 767    common code.  */
 768
 769 int
 770 c_expand_decl (tree decl)
 771 {
 772   if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl))
 773     {
 774       /* Let the back-end know about this variable.  */
 775       if (!anon_aggr_type_p (TREE_TYPE (decl)))
 776         emit_local_var (decl);
 777       else
 778         expand_anon_union_decl (decl, NULL_TREE,
 779                                 DECL_ANON_UNION_ELEMS (decl));
 780     }
 781   else
 782     return 0;
 783
 784   return 1;
 785 }
 786
 787
 788 /* Return the VAR_DECL for a const char array naming the current
 789    function. If the VAR_DECL has not yet been created, create it
 790    now. RID indicates how it should be formatted and IDENTIFIER_NODE
 791    ID is its name (unfortunately C and C++ hold the RID values of
 792    keywords in different places, so we can't derive RID from ID in
 793    this language independent code.  */
 794
 795 tree
 796 fname_decl (unsigned int rid, tree id)
 797 {
 798   unsigned ix;
 799   tree decl = NULL_TREE;
 800
 801   for (ix = 0; fname_vars[ix].decl; ix++)
 802     if (fname_vars[ix].rid == rid)
 803       break;
 804
 805   decl = *fname_vars[ix].decl;
 806   if (!decl)
 807     {
 808       /* If a tree is built here, it would normally have the lineno of
 809          the current statement.  Later this tree will be moved to the
 810          beginning of the function and this line number will be wrong.
 811          To avoid this problem set the lineno to 0 here; that prevents
 812          it from appearing in the RTL.  */
 813       tree stmts;
 814       location_t saved_location = input_location;
 815 #ifdef USE_MAPPED_LOCATION
 816       input_location = UNKNOWN_LOCATION;
 817 #else
 818       input_line = 0;
 819 #endif
 820
 821       stmts = push_stmt_list ();
 822       decl = (*make_fname_decl) (id, fname_vars[ix].pretty);
 823       stmts = pop_stmt_list (stmts);
 824       if (!IS_EMPTY_STMT (stmts))
 825         saved_function_name_decls
 826           = tree_cons (decl, stmts, saved_function_name_decls);
 827       *fname_vars[ix].decl = decl;
 828       input_location = saved_location;
 829     }
 830   if (!ix && !current_function_decl)
 831     pedwarn ("%qD is not defined outside of function scope", decl);
 832
 833   return decl;
 834 }
 835
 836 /* Given a STRING_CST, give it a suitable array-of-chars data type.  */
 837
 838 tree
 839 fix_string_type (tree value)
 840 {
 841   const int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
 842   const int wide_flag = TREE_TYPE (value) == wchar_array_type_node;
 843   int length = TREE_STRING_LENGTH (value);
 844   int nchars;
 845   tree e_type, i_type, a_type;
 846
 847   /* Compute the number of elements, for the array type.  */
 848   nchars = wide_flag ? length / wchar_bytes : length;
 849
 850   /* C89 2.2.4.1, C99 5.2.4.1 (Translation limits).  The analogous
 851      limit in C++98 Annex B is very large (65536) and is not normative,
 852      so we do not diagnose it (warn_overlength_strings is forced off
 853      in c_common_post_options).  */
 854   if (warn_overlength_strings)
 855     {
 856       const int nchars_max = flag_isoc99 ? 4095 : 509;
 857       const int relevant_std = flag_isoc99 ? 99 : 90;
 858       if (nchars - 1 > nchars_max)
 859         /* Translators: The %d after 'ISO C' will be 90 or 99.  Do not
 860            separate the %d from the 'C'.  'ISO' should not be
 861            translated, but it may be moved after 'C%d' in languages
 862            where modifiers follow nouns.  */
 863         pedwarn ("string length %qd is greater than the length %qd "
 864                  "ISO C%d compilers are required to support",
 865                  nchars - 1, nchars_max, relevant_std);
 866     }
 867
 868   /* Create the array type for the string constant.  The ISO C++
 869      standard says that a string literal has type `const char[N]' or
 870      `const wchar_t[N]'.  We use the same logic when invoked as a C
 871      front-end with -Wwrite-strings.
 872      ??? We should change the type of an expression depending on the
 873      state of a warning flag.  We should just be warning -- see how
 874      this is handled in the C++ front-end for the deprecated implicit
 875      conversion from string literals to `char*' or `wchar_t*'.
 876
 877      The C++ front end relies on TYPE_MAIN_VARIANT of a cv-qualified
 878      array type being the unqualified version of that type.
 879      Therefore, if we are constructing an array of const char, we must
 880      construct the matching unqualified array type first.  The C front
 881      end does not require this, but it does no harm, so we do it
 882      unconditionally.  */
 883   e_type = wide_flag ? wchar_type_node : char_type_node;
 884   i_type = build_index_type (build_int_cst (NULL_TREE, nchars - 1));
 885   a_type = build_array_type (e_type, i_type);
 886   if (c_dialect_cxx() || warn_write_strings)
 887     a_type = c_build_qualified_type (a_type, TYPE_QUAL_CONST);
 888
 889   TREE_TYPE (value) = a_type;
 890   TREE_CONSTANT (value) = 1;
 891   TREE_INVARIANT (value) = 1;
 892   TREE_READONLY (value) = 1;
 893   TREE_STATIC (value) = 1;
 894   return value;
 895 }
 896 \f
 897 /* Print a warning if a constant expression had overflow in folding.
 898    Invoke this function on every expression that the language
 899    requires to be a constant expression.
 900    Note the ANSI C standard says it is erroneous for a
 901    constant expression to overflow.  */
 902
 903 void
 904 constant_expression_warning (tree value)
 905 {
 906   if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
 907        || TREE_CODE (value) == VECTOR_CST
 908        || TREE_CODE (value) == COMPLEX_CST)
 909       && TREE_CONSTANT_OVERFLOW (value)
 910       && warn_overflow
 911       && pedantic)
 912     pedwarn ("overflow in constant expression");
 913 }
 914
 915 /* Print a warning if an expression had overflow in folding.
 916    Invoke this function on every expression that
 917    (1) appears in the source code, and
 918    (2) might be a constant expression that overflowed, and
 919    (3) is not already checked by convert_and_check;
 920    however, do not invoke this function on operands of explicit casts.  */
 921
 922 void
 923 overflow_warning (tree value)
 924 {
 925   if ((TREE_CODE (value) == INTEGER_CST
 926        || (TREE_CODE (value) == COMPLEX_CST
 927            && TREE_CODE (TREE_REALPART (value)) == INTEGER_CST))
 928       && TREE_OVERFLOW (value))
 929     {
 930       TREE_OVERFLOW (value) = 0;
 931       if (skip_evaluation == 0)
 932         warning (OPT_Woverflow, "integer overflow in expression");
 933     }
 934   else if ((TREE_CODE (value) == REAL_CST
 935             || (TREE_CODE (value) == COMPLEX_CST
 936                 && TREE_CODE (TREE_REALPART (value)) == REAL_CST))
 937            && TREE_OVERFLOW (value))
 938     {
 939       TREE_OVERFLOW (value) = 0;
 940       if (skip_evaluation == 0)
 941         warning (OPT_Woverflow, "floating point overflow in expression");
 942     }
 943   else if (TREE_CODE (value) == VECTOR_CST && TREE_OVERFLOW (value))
 944     {
 945       TREE_OVERFLOW (value) = 0;
 946       if (skip_evaluation == 0)
 947         warning (OPT_Woverflow, "vector overflow in expression");
 948     }
 949 }
 950
 951 /* Print a warning if a large constant is truncated to unsigned,
 952    or if -Wconversion is used and a constant < 0 is converted to unsigned.
 953    Invoke this function on every expression that might be implicitly
 954    converted to an unsigned type.  */
 955
 956 static void
 957 unsigned_conversion_warning (tree result, tree operand)
 958 {
 959   tree type = TREE_TYPE (result);
 960
 961   if (TREE_CODE (operand) == INTEGER_CST
 962       && TREE_CODE (type) == INTEGER_TYPE
 963       && TYPE_UNSIGNED (type)
 964       && skip_evaluation == 0
 965       && !int_fits_type_p (operand, type))
 966     {
 967       if (!int_fits_type_p (operand, c_common_signed_type (type)))
 968         /* This detects cases like converting -129 or 256 to unsigned char.  */
 969         warning (OPT_Woverflow,
 970                  "large integer implicitly truncated to unsigned type");
 971       else
 972         warning (OPT_Wconversion,
 973                  "negative integer implicitly converted to unsigned type");
 974     }
 975 }
 976
 977 /* Print a warning about casts that might indicate violation
 978    of strict aliasing rules if -Wstrict-aliasing is used and
 979    strict aliasing mode is in effect. otype is the original
 980    TREE_TYPE of expr, and type the type we're casting to. */
 981
 982 void
 983 strict_aliasing_warning(tree otype, tree type, tree expr)
 984 {
 985   if (flag_strict_aliasing && warn_strict_aliasing
 986       && POINTER_TYPE_P (type) && POINTER_TYPE_P (otype)
 987       && TREE_CODE (expr) == ADDR_EXPR
 988       && (DECL_P (TREE_OPERAND (expr, 0))
 989           || handled_component_p (TREE_OPERAND (expr, 0)))
 990       && !VOID_TYPE_P (TREE_TYPE (type)))
 991     {
 992       /* Casting the address of an object to non void pointer. Warn
 993          if the cast breaks type based aliasing.  */
 994       if (!COMPLETE_TYPE_P (TREE_TYPE (type)))
 995         warning (OPT_Wstrict_aliasing, "type-punning to incomplete type "
 996                  "might break strict-aliasing rules");
 997       else
 998         {
 999           HOST_WIDE_INT set1 = get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0)));
1000           HOST_WIDE_INT set2 = get_alias_set (TREE_TYPE (type));
1001
1002           if (!alias_sets_conflict_p (set1, set2))
1003             warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1004                      "pointer will break strict-aliasing rules");
1005           else if (warn_strict_aliasing > 1
1006                   && !alias_sets_might_conflict_p (set1, set2))
1007             warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
1008                      "pointer might break strict-aliasing rules");
1009         }
1010     }
1011 }
1012
1013
1014 /* Print a warning about if (); or if () .. else; constructs
1015    via the special empty statement node that we create.  INNER_THEN
1016    and INNER_ELSE are the statement lists of the if and the else
1017    block.  */
1018
1019 void
1020 empty_body_warning (tree inner_then, tree inner_else)
1021 {
1022   if (extra_warnings)
1023     {
1024       if (TREE_CODE (inner_then) == STATEMENT_LIST
1025           && STATEMENT_LIST_TAIL (inner_then))
1026         inner_then = STATEMENT_LIST_TAIL (inner_then)->stmt;
1027
1028       if (inner_else && TREE_CODE (inner_else) == STATEMENT_LIST
1029           && STATEMENT_LIST_TAIL (inner_else))
1030         inner_else = STATEMENT_LIST_TAIL (inner_else)->stmt;
1031
1032       if (IS_EMPTY_STMT (inner_then) && !inner_else)
1033         warning (OPT_Wextra, "%Hempty body in an if-statement",
1034                  EXPR_LOCUS (inner_then));
1035
1036       if (inner_else && IS_EMPTY_STMT (inner_else))
1037         warning (OPT_Wextra, "%Hempty body in an else-statement",
1038                  EXPR_LOCUS (inner_else));
1039    }
1040 }
1041
1042
1043 /* Nonzero if constant C has a value that is permissible
1044    for type TYPE (an INTEGER_TYPE).  */
1045
1046 static int
1047 constant_fits_type_p (tree c, tree type)
1048 {
1049   if (TREE_CODE (c) == INTEGER_CST)
1050     return int_fits_type_p (c, type);
1051
1052   c = convert (type, c);
1053   return !TREE_OVERFLOW (c);
1054 }
1055
1056 /* Nonzero if vector types T1 and T2 can be converted to each other
1057    without an explicit cast.  */
1058 int
1059 vector_types_convertible_p (tree t1, tree t2)
1060 {
1061   return targetm.vector_opaque_p (t1)
1062          || targetm.vector_opaque_p (t2)
1063          || (tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2))
1064              && (TREE_CODE (TREE_TYPE (t1)) != REAL_TYPE ||
1065                  TYPE_PRECISION (t1) == TYPE_PRECISION (t2))
1066              && INTEGRAL_TYPE_P (TREE_TYPE (t1))
1067                 == INTEGRAL_TYPE_P (TREE_TYPE (t2)));
1068 }
1069
1070 /* Convert EXPR to TYPE, warning about conversion problems with constants.
1071    Invoke this function on every expression that is converted implicitly,
1072    i.e. because of language rules and not because of an explicit cast.  */
1073
1074 tree
1075 convert_and_check (tree type, tree expr)
1076 {
1077   tree t = convert (type, expr);
1078   if (TREE_CODE (t) == INTEGER_CST)
1079     {
1080       if (TREE_OVERFLOW (t))
1081         {
1082           TREE_OVERFLOW (t) = 0;
1083
1084           /* Do not diagnose overflow in a constant expression merely
1085              because a conversion overflowed.  */
1086           TREE_CONSTANT_OVERFLOW (t) = CONSTANT_CLASS_P (expr)
1087                                        && TREE_CONSTANT_OVERFLOW (expr);
1088
1089           /* No warning for converting 0x80000000 to int.  */
1090           if (!(TYPE_UNSIGNED (type) < TYPE_UNSIGNED (TREE_TYPE (expr))
1091                 && TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
1092                 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (expr))))
1093             /* If EXPR fits in the unsigned version of TYPE,
1094                don't warn unless pedantic.  */
1095             if ((pedantic
1096                  || TYPE_UNSIGNED (type)
1097                  || !constant_fits_type_p (expr,
1098                                            c_common_unsigned_type (type)))
1099                 && skip_evaluation == 0)
1100               warning (OPT_Woverflow,
1101                        "overflow in implicit constant conversion");
1102         }
1103       else
1104         unsigned_conversion_warning (t, expr);
1105     }
1106   return t;
1107 }
1108 \f
1109 /* A node in a list that describes references to variables (EXPR), which are
1110    either read accesses if WRITER is zero, or write accesses, in which case
1111    WRITER is the parent of EXPR.  */
1112 struct tlist
1113 {
1114   struct tlist *next;
1115   tree expr, writer;
1116 };
1117
1118 /* Used to implement a cache the results of a call to verify_tree.  We only
1119    use this for SAVE_EXPRs.  */
1120 struct tlist_cache
1121 {
1122   struct tlist_cache *next;
1123   struct tlist *cache_before_sp;
1124   struct tlist *cache_after_sp;
1125   tree expr;
1126 };
1127
1128 /* Obstack to use when allocating tlist structures, and corresponding
1129    firstobj.  */
1130 static struct obstack tlist_obstack;
1131 static char *tlist_firstobj = 0;
1132
1133 /* Keep track of the identifiers we've warned about, so we can avoid duplicate
1134    warnings.  */
1135 static struct tlist *warned_ids;
1136 /* SAVE_EXPRs need special treatment.  We process them only once and then
1137    cache the results.  */
1138 static struct tlist_cache *save_expr_cache;
1139
1140 static void add_tlist (struct tlist **, struct tlist *, tree, int);
1141 static void merge_tlist (struct tlist **, struct tlist *, int);
1142 static void verify_tree (tree, struct tlist **, struct tlist **, tree);
1143 static int warning_candidate_p (tree);
1144 static void warn_for_collisions (struct tlist *);
1145 static void warn_for_collisions_1 (tree, tree, struct tlist *, int);
1146 static struct tlist *new_tlist (struct tlist *, tree, tree);
1147
1148 /* Create a new struct tlist and fill in its fields.  */
1149 static struct tlist *
1150 new_tlist (struct tlist *next, tree t, tree writer)
1151 {
1152   struct tlist *l;
1153   l = XOBNEW (&tlist_obstack, struct tlist);
1154   l->next = next;
1155   l->expr = t;
1156   l->writer = writer;
1157   return l;
1158 }
1159
1160 /* Add duplicates of the nodes found in ADD to the list *TO.  If EXCLUDE_WRITER
1161    is nonnull, we ignore any node we find which has a writer equal to it.  */
1162
1163 static void
1164 add_tlist (struct tlist **to, struct tlist *add, tree exclude_writer, int copy)
1165 {
1166   while (add)
1167     {
1168       struct tlist *next = add->next;
1169       if (!copy)
1170         add->next = *to;
1171       if (!exclude_writer || add->writer != exclude_writer)
1172         *to = copy ? new_tlist (*to, add->expr, add->writer) : add;
1173       add = next;
1174     }
1175 }
1176
1177 /* Merge the nodes of ADD into TO.  This merging process is done so that for
1178    each variable that already exists in TO, no new node is added; however if
1179    there is a write access recorded in ADD, and an occurrence on TO is only
1180    a read access, then the occurrence in TO will be modified to record the
1181    write.  */
1182
1183 static void
1184 merge_tlist (struct tlist **to, struct tlist *add, int copy)
1185 {
1186   struct tlist **end = to;
1187
1188   while (*end)
1189     end = &(*end)->next;
1190
1191   while (add)
1192     {
1193       int found = 0;
1194       struct tlist *tmp2;
1195       struct tlist *next = add->next;
1196
1197       for (tmp2 = *to; tmp2; tmp2 = tmp2->next)
1198         if (tmp2->expr == add->expr)
1199           {
1200             found = 1;
1201             if (!tmp2->writer)
1202               tmp2->writer = add->writer;
1203           }
1204       if (!found)
1205         {
1206           *end = copy ? add : new_tlist (NULL, add->expr, add->writer);
1207           end = &(*end)->next;
1208           *end = 0;
1209         }
1210       add = next;
1211     }
1212 }
1213
1214 /* WRITTEN is a variable, WRITER is its parent.  Warn if any of the variable
1215    references in list LIST conflict with it, excluding reads if ONLY writers
1216    is nonzero.  */
1217
1218 static void
1219 warn_for_collisions_1 (tree written, tree writer, struct tlist *list,
1220                        int only_writes)
1221 {
1222   struct tlist *tmp;
1223
1224   /* Avoid duplicate warnings.  */
1225   for (tmp = warned_ids; tmp; tmp = tmp->next)
1226     if (tmp->expr == written)
1227       return;
1228
1229   while (list)
1230     {
1231       if (list->expr == written
1232           && list->writer != writer
1233           && (!only_writes || list->writer)
1234           && DECL_NAME (list->expr))
1235         {
1236           warned_ids = new_tlist (warned_ids, written, NULL_TREE);
1237           warning (0, "operation on %qE may be undefined", list->expr);
1238         }
1239       list = list->next;
1240     }
1241 }
1242
1243 /* Given a list LIST of references to variables, find whether any of these
1244    can cause conflicts due to missing sequence points.  */
1245
1246 static void
1247 warn_for_collisions (struct tlist *list)
1248 {
1249   struct tlist *tmp;
1250
1251   for (tmp = list; tmp; tmp = tmp->next)
1252     {
1253       if (tmp->writer)
1254         warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0);
1255     }
1256 }
1257
1258 /* Return nonzero if X is a tree that can be verified by the sequence point
1259    warnings.  */
1260 static int
1261 warning_candidate_p (tree x)
1262 {
1263   return TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == PARM_DECL;
1264 }
1265
1266 /* Walk the tree X, and record accesses to variables.  If X is written by the
1267    parent tree, WRITER is the parent.
1268    We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP.  If this
1269    expression or its only operand forces a sequence point, then everything up
1270    to the sequence point is stored in PBEFORE_SP.  Everything else gets stored
1271    in PNO_SP.
1272    Once we return, we will have emitted warnings if any subexpression before
1273    such a sequence point could be undefined.  On a higher level, however, the
1274    sequence point may not be relevant, and we'll merge the two lists.
1275
1276    Example: (b++, a) + b;
1277    The call that processes the COMPOUND_EXPR will store the increment of B
1278    in PBEFORE_SP, and the use of A in PNO_SP.  The higher-level call that
1279    processes the PLUS_EXPR will need to merge the two lists so that
1280    eventually, all accesses end up on the same list (and we'll warn about the
1281    unordered subexpressions b++ and b.
1282
1283    A note on merging.  If we modify the former example so that our expression
1284    becomes
1285      (b++, b) + a
1286    care must be taken not simply to add all three expressions into the final
1287    PNO_SP list.  The function merge_tlist takes care of that by merging the
1288    before-SP list of the COMPOUND_EXPR into its after-SP list in a special
1289    way, so that no more than one access to B is recorded.  */
1290
1291 static void
1292 verify_tree (tree x, struct tlist **pbefore_sp, struct tlist **pno_sp,
1293              tree writer)
1294 {
1295   struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3;
1296   enum tree_code code;
1297   enum tree_code_class cl;
1298
1299   /* X may be NULL if it is the operand of an empty statement expression
1300      ({ }).  */
1301   if (x == NULL)
1302     return;
1303
1304  restart:
1305   code = TREE_CODE (x);
1306   cl = TREE_CODE_CLASS (code);
1307
1308   if (warning_candidate_p (x))
1309     {
1310       *pno_sp = new_tlist (*pno_sp, x, writer);
1311       return;
1312     }
1313
1314   switch (code)
1315     {
1316     case CONSTRUCTOR:
1317       return;
1318
1319     case COMPOUND_EXPR:
1320     case TRUTH_ANDIF_EXPR:
1321     case TRUTH_ORIF_EXPR:
1322       tmp_before = tmp_nosp = tmp_list3 = 0;
1323       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1324       warn_for_collisions (tmp_nosp);
1325       merge_tlist (pbefore_sp, tmp_before, 0);
1326       merge_tlist (pbefore_sp, tmp_nosp, 0);
1327       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE);
1328       merge_tlist (pbefore_sp, tmp_list3, 0);
1329       return;
1330
1331     case COND_EXPR:
1332       tmp_before = tmp_list2 = 0;
1333       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE);
1334       warn_for_collisions (tmp_list2);
1335       merge_tlist (pbefore_sp, tmp_before, 0);
1336       merge_tlist (pbefore_sp, tmp_list2, 1);
1337
1338       tmp_list3 = tmp_nosp = 0;
1339       verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE);
1340       warn_for_collisions (tmp_nosp);
1341       merge_tlist (pbefore_sp, tmp_list3, 0);
1342
1343       tmp_list3 = tmp_list2 = 0;
1344       verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE);
1345       warn_for_collisions (tmp_list2);
1346       merge_tlist (pbefore_sp, tmp_list3, 0);
1347       /* Rather than add both tmp_nosp and tmp_list2, we have to merge the
1348          two first, to avoid warning for (a ? b++ : b++).  */
1349       merge_tlist (&tmp_nosp, tmp_list2, 0);
1350       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1351       return;
1352
1353     case PREDECREMENT_EXPR:
1354     case PREINCREMENT_EXPR:
1355     case POSTDECREMENT_EXPR:
1356     case POSTINCREMENT_EXPR:
1357       verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x);
1358       return;
1359
1360     case MODIFY_EXPR:
1361       tmp_before = tmp_nosp = tmp_list3 = 0;
1362       verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE);
1363       verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x);
1364       /* Expressions inside the LHS are not ordered wrt. the sequence points
1365          in the RHS.  Example:
1366            *a = (a++, 2)
1367          Despite the fact that the modification of "a" is in the before_sp
1368          list (tmp_before), it conflicts with the use of "a" in the LHS.
1369          We can handle this by adding the contents of tmp_list3
1370          to those of tmp_before, and redoing the collision warnings for that
1371          list.  */
1372       add_tlist (&tmp_before, tmp_list3, x, 1);
1373       warn_for_collisions (tmp_before);
1374       /* Exclude the LHS itself here; we first have to merge it into the
1375          tmp_nosp list.  This is done to avoid warning for "a = a"; if we
1376          didn't exclude the LHS, we'd get it twice, once as a read and once
1377          as a write.  */
1378       add_tlist (pno_sp, tmp_list3, x, 0);
1379       warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1);
1380
1381       merge_tlist (pbefore_sp, tmp_before, 0);
1382       if (warning_candidate_p (TREE_OPERAND (x, 0)))
1383         merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0);
1384       add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1);
1385       return;
1386
1387     case CALL_EXPR:
1388       /* We need to warn about conflicts among arguments and conflicts between
1389          args and the function address.  Side effects of the function address,
1390          however, are not ordered by the sequence point of the call.  */
1391       tmp_before = tmp_nosp = tmp_list2 = tmp_list3 = 0;
1392       verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1393       if (TREE_OPERAND (x, 1))
1394         verify_tree (TREE_OPERAND (x, 1), &tmp_list2, &tmp_list3, NULL_TREE);
1395       merge_tlist (&tmp_list3, tmp_list2, 0);
1396       add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0);
1397       add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0);
1398       warn_for_collisions (tmp_before);
1399       add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0);
1400       return;
1401
1402     case TREE_LIST:
1403       /* Scan all the list, e.g. indices of multi dimensional array.  */
1404       while (x)
1405         {
1406           tmp_before = tmp_nosp = 0;
1407           verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE);
1408           merge_tlist (&tmp_nosp, tmp_before, 0);
1409           add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1410           x = TREE_CHAIN (x);
1411         }
1412       return;
1413
1414     case SAVE_EXPR:
1415       {
1416         struct tlist_cache *t;
1417         for (t = save_expr_cache; t; t = t->next)
1418           if (t->expr == x)
1419             break;
1420
1421         if (!t)
1422           {
1423             t = XOBNEW (&tlist_obstack, struct tlist_cache);
1424             t->next = save_expr_cache;
1425             t->expr = x;
1426             save_expr_cache = t;
1427
1428             tmp_before = tmp_nosp = 0;
1429             verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
1430             warn_for_collisions (tmp_nosp);
1431
1432             tmp_list3 = 0;
1433             while (tmp_nosp)
1434               {
1435                 struct tlist *t = tmp_nosp;
1436                 tmp_nosp = t->next;
1437                 merge_tlist (&tmp_list3, t, 0);
1438               }
1439             t->cache_before_sp = tmp_before;
1440             t->cache_after_sp = tmp_list3;
1441           }
1442         merge_tlist (pbefore_sp, t->cache_before_sp, 1);
1443         add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1);
1444         return;
1445       }
1446
1447     default:
1448       /* For other expressions, simply recurse on their operands.
1449          Manual tail recursion for unary expressions.
1450          Other non-expressions need not be processed.  */
1451       if (cl == tcc_unary)
1452         {
1453           x = TREE_OPERAND (x, 0);
1454           writer = 0;
1455           goto restart;
1456         }
1457       else if (IS_EXPR_CODE_CLASS (cl))
1458         {
1459           int lp;
1460           int max = TREE_CODE_LENGTH (TREE_CODE (x));
1461           for (lp = 0; lp < max; lp++)
1462             {
1463               tmp_before = tmp_nosp = 0;
1464               verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, 0);
1465               merge_tlist (&tmp_nosp, tmp_before, 0);
1466               add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
1467             }
1468         }
1469       return;
1470     }
1471 }
1472
1473 /* Try to warn for undefined behavior in EXPR due to missing sequence
1474    points.  */
1475
1476 void
1477 verify_sequence_points (tree expr)
1478 {
1479   struct tlist *before_sp = 0, *after_sp = 0;
1480
1481   warned_ids = 0;
1482   save_expr_cache = 0;
1483   if (tlist_firstobj == 0)
1484     {
1485       gcc_obstack_init (&tlist_obstack);
1486       tlist_firstobj = (char *) obstack_alloc (&tlist_obstack, 0);
1487     }
1488
1489   verify_tree (expr, &before_sp, &after_sp, 0);
1490   warn_for_collisions (after_sp);
1491   obstack_free (&tlist_obstack, tlist_firstobj);
1492 }
1493 \f
1494 /* Validate the expression after `case' and apply default promotions.  */
1495
1496 static tree
1497 check_case_value (tree value)
1498 {
1499   if (value == NULL_TREE)
1500     return value;
1501
1502   /* ??? Can we ever get nops here for a valid case value?  We
1503      shouldn't for C.  */
1504   STRIP_TYPE_NOPS (value);
1505   /* In C++, the following is allowed:
1506
1507        const int i = 3;
1508        switch (...) { case i: ... }
1509
1510      So, we try to reduce the VALUE to a constant that way.  */
1511   if (c_dialect_cxx ())
1512     {
1513       value = decl_constant_value (value);
1514       STRIP_TYPE_NOPS (value);
1515       value = fold (value);
1516     }
1517
1518   if (TREE_CODE (value) == INTEGER_CST)
1519     /* Promote char or short to int.  */
1520     value = perform_integral_promotions (value);
1521   else if (value != error_mark_node)
1522     {
1523       error ("case label does not reduce to an integer constant");
1524       value = error_mark_node;
1525     }
1526
1527   constant_expression_warning (value);
1528
1529   return value;
1530 }
1531 \f
1532 /* See if the case values LOW and HIGH are in the range of the original
1533    type (i.e. before the default conversion to int) of the switch testing
1534    expression.
1535    TYPE is the promoted type of the testing expression, and ORIG_TYPE is
1536    the type before promoting it.  CASE_LOW_P is a pointer to the lower
1537    bound of the case label, and CASE_HIGH_P is the upper bound or NULL
1538    if the case is not a case range.
1539    The caller has to make sure that we are not called with NULL for
1540    CASE_LOW_P (i.e. the default case).
1541    Returns true if the case label is in range of ORIG_TYPE (saturated or
1542    untouched) or false if the label is out of range.  */
1543
1544 static bool
1545 check_case_bounds (tree type, tree orig_type,
1546                    tree *case_low_p, tree *case_high_p)
1547 {
1548   tree min_value, max_value;
1549   tree case_low = *case_low_p;
1550   tree case_high = case_high_p ? *case_high_p : case_low;
1551
1552   /* If there was a problem with the original type, do nothing.  */
1553   if (orig_type == error_mark_node)
1554     return true;
1555
1556   min_value = TYPE_MIN_VALUE (orig_type);
1557   max_value = TYPE_MAX_VALUE (orig_type);
1558
1559   /* Case label is less than minimum for type.  */
1560   if (tree_int_cst_compare (case_low, min_value) < 0
1561       && tree_int_cst_compare (case_high, min_value) < 0)
1562     {
1563       warning (0, "case label value is less than minimum value for type");
1564       return false;
1565     }
1566
1567   /* Case value is greater than maximum for type.  */
1568   if (tree_int_cst_compare (case_low, max_value) > 0
1569       && tree_int_cst_compare (case_high, max_value) > 0)
1570     {
1571       warning (0, "case label value exceeds maximum value for type");
1572       return false;
1573     }
1574
1575   /* Saturate lower case label value to minimum.  */
1576   if (tree_int_cst_compare (case_high, min_value) >= 0
1577       && tree_int_cst_compare (case_low, min_value) < 0)
1578     {
1579       warning (0, "lower value in case label range"
1580                " less than minimum value for type");
1581       case_low = min_value;
1582     }
1583
1584   /* Saturate upper case label value to maximum.  */
1585   if (tree_int_cst_compare (case_low, max_value) <= 0
1586       && tree_int_cst_compare (case_high, max_value) > 0)
1587     {
1588       warning (0, "upper value in case label range"
1589                " exceeds maximum value for type");
1590       case_high = max_value;
1591     }
1592
1593   if (*case_low_p != case_low)
1594     *case_low_p = convert (type, case_low);
1595   if (case_high_p && *case_high_p != case_high)
1596     *case_high_p = convert (type, case_high);
1597
1598   return true;
1599 }
1600 \f
1601 /* Return an integer type with BITS bits of precision,
1602    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
1603
1604 tree
1605 c_common_type_for_size (unsigned int bits, int unsignedp)
1606 {
1607   if (bits == TYPE_PRECISION (integer_type_node))
1608     return unsignedp ? unsigned_type_node : integer_type_node;
1609
1610   if (bits == TYPE_PRECISION (signed_char_type_node))
1611     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1612
1613   if (bits == TYPE_PRECISION (short_integer_type_node))
1614     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1615
1616   if (bits == TYPE_PRECISION (long_integer_type_node))
1617     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1618
1619   if (bits == TYPE_PRECISION (long_long_integer_type_node))
1620     return (unsignedp ? long_long_unsigned_type_node
1621             : long_long_integer_type_node);
1622
1623   if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
1624     return (unsignedp ? widest_unsigned_literal_type_node
1625             : widest_integer_literal_type_node);
1626
1627   if (bits <= TYPE_PRECISION (intQI_type_node))
1628     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1629
1630   if (bits <= TYPE_PRECISION (intHI_type_node))
1631     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1632
1633   if (bits <= TYPE_PRECISION (intSI_type_node))
1634     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1635
1636   if (bits <= TYPE_PRECISION (intDI_type_node))
1637     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1638
1639   return 0;
1640 }
1641
1642 /* Used for communication between c_common_type_for_mode and
1643    c_register_builtin_type.  */
1644 static GTY(()) tree registered_builtin_types;
1645
1646 /* Return a data type that has machine mode MODE.
1647    If the mode is an integer,
1648    then UNSIGNEDP selects between signed and unsigned types.  */
1649
1650 tree
1651 c_common_type_for_mode (enum machine_mode mode, int unsignedp)
1652 {
1653   tree t;
1654
1655   if (mode == TYPE_MODE (integer_type_node))
1656     return unsignedp ? unsigned_type_node : integer_type_node;
1657
1658   if (mode == TYPE_MODE (signed_char_type_node))
1659     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1660
1661   if (mode == TYPE_MODE (short_integer_type_node))
1662     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1663
1664   if (mode == TYPE_MODE (long_integer_type_node))
1665     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1666
1667   if (mode == TYPE_MODE (long_long_integer_type_node))
1668     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
1669
1670   if (mode == TYPE_MODE (widest_integer_literal_type_node))
1671     return unsignedp ? widest_unsigned_literal_type_node
1672                      : widest_integer_literal_type_node;
1673
1674   if (mode == QImode)
1675     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1676
1677   if (mode == HImode)
1678     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1679
1680   if (mode == SImode)
1681     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1682
1683   if (mode == DImode)
1684     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1685
1686 #if HOST_BITS_PER_WIDE_INT >= 64
1687   if (mode == TYPE_MODE (intTI_type_node))
1688     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
1689 #endif
1690
1691   if (mode == TYPE_MODE (float_type_node))
1692     return float_type_node;
1693
1694   if (mode == TYPE_MODE (double_type_node))
1695     return double_type_node;
1696
1697   if (mode == TYPE_MODE (long_double_type_node))
1698     return long_double_type_node;
1699
1700   if (mode == TYPE_MODE (void_type_node))
1701     return void_type_node;
1702
1703   if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
1704     return (unsignedp
1705             ? make_unsigned_type (GET_MODE_PRECISION (mode))
1706             : make_signed_type (GET_MODE_PRECISION (mode)));
1707
1708   if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
1709     return (unsignedp
1710             ? make_unsigned_type (GET_MODE_PRECISION (mode))
1711             : make_signed_type (GET_MODE_PRECISION (mode)));
1712
1713   if (COMPLEX_MODE_P (mode))
1714     {
1715       enum machine_mode inner_mode;
1716       tree inner_type;
1717
1718       if (mode == TYPE_MODE (complex_float_type_node))
1719         return complex_float_type_node;
1720       if (mode == TYPE_MODE (complex_double_type_node))
1721         return complex_double_type_node;
1722       if (mode == TYPE_MODE (complex_long_double_type_node))
1723         return complex_long_double_type_node;
1724
1725       if (mode == TYPE_MODE (complex_integer_type_node) && !unsignedp)
1726         return complex_integer_type_node;
1727
1728       inner_mode = GET_MODE_INNER (mode);
1729       inner_type = c_common_type_for_mode (inner_mode, unsignedp);
1730       if (inner_type != NULL_TREE)
1731         return build_complex_type (inner_type);
1732     }
1733   else if (VECTOR_MODE_P (mode))
1734     {
1735       enum machine_mode inner_mode = GET_MODE_INNER (mode);
1736       tree inner_type = c_common_type_for_mode (inner_mode, unsignedp);
1737       if (inner_type != NULL_TREE)
1738         return build_vector_type_for_mode (inner_type, mode);
1739     }
1740
1741   if (mode == TYPE_MODE (dfloat32_type_node))
1742     return dfloat32_type_node;
1743   if (mode == TYPE_MODE (dfloat64_type_node))
1744     return dfloat64_type_node;
1745   if (mode == TYPE_MODE (dfloat128_type_node))
1746     return dfloat128_type_node;
1747
1748   for (t = registered_builtin_types; t; t = TREE_CHAIN (t))
1749     if (TYPE_MODE (TREE_VALUE (t)) == mode)
1750       return TREE_VALUE (t);
1751
1752   return 0;
1753 }
1754
1755 /* Return an unsigned type the same as TYPE in other respects.  */
1756 tree
1757 c_common_unsigned_type (tree type)
1758 {
1759   tree type1 = TYPE_MAIN_VARIANT (type);
1760   if (type1 == signed_char_type_node || type1 == char_type_node)
1761     return unsigned_char_type_node;
1762   if (type1 == integer_type_node)
1763     return unsigned_type_node;
1764   if (type1 == short_integer_type_node)
1765     return short_unsigned_type_node;
1766   if (type1 == long_integer_type_node)
1767     return long_unsigned_type_node;
1768   if (type1 == long_long_integer_type_node)
1769     return long_long_unsigned_type_node;
1770   if (type1 == widest_integer_literal_type_node)
1771     return widest_unsigned_literal_type_node;
1772 #if HOST_BITS_PER_WIDE_INT >= 64
1773   if (type1 == intTI_type_node)
1774     return unsigned_intTI_type_node;
1775 #endif
1776   if (type1 == intDI_type_node)
1777     return unsigned_intDI_type_node;
1778   if (type1 == intSI_type_node)
1779     return unsigned_intSI_type_node;
1780   if (type1 == intHI_type_node)
1781     return unsigned_intHI_type_node;
1782   if (type1 == intQI_type_node)
1783     return unsigned_intQI_type_node;
1784
1785   return c_common_signed_or_unsigned_type (1, type);
1786 }
1787
1788 /* Return a signed type the same as TYPE in other respects.  */
1789
1790 tree
1791 c_common_signed_type (tree type)
1792 {
1793   tree type1 = TYPE_MAIN_VARIANT (type);
1794   if (type1 == unsigned_char_type_node || type1 == char_type_node)
1795     return signed_char_type_node;
1796   if (type1 == unsigned_type_node)
1797     return integer_type_node;
1798   if (type1 == short_unsigned_type_node)
1799     return short_integer_type_node;
1800   if (type1 == long_unsigned_type_node)
1801     return long_integer_type_node;
1802   if (type1 == long_long_unsigned_type_node)
1803     return long_long_integer_type_node;
1804   if (type1 == widest_unsigned_literal_type_node)
1805     return widest_integer_literal_type_node;
1806 #if HOST_BITS_PER_WIDE_INT >= 64
1807   if (type1 == unsigned_intTI_type_node)
1808     return intTI_type_node;
1809 #endif
1810   if (type1 == unsigned_intDI_type_node)
1811     return intDI_type_node;
1812   if (type1 == unsigned_intSI_type_node)
1813     return intSI_type_node;
1814   if (type1 == unsigned_intHI_type_node)
1815     return intHI_type_node;
1816   if (type1 == unsigned_intQI_type_node)
1817     return intQI_type_node;
1818
1819   return c_common_signed_or_unsigned_type (0, type);
1820 }
1821
1822 /* Return a type the same as TYPE except unsigned or
1823    signed according to UNSIGNEDP.  */
1824
1825 tree
1826 c_common_signed_or_unsigned_type (int unsignedp, tree type)
1827 {
1828   if (!INTEGRAL_TYPE_P (type)
1829       || TYPE_UNSIGNED (type) == unsignedp)
1830     return type;
1831
1832   /* For ENUMERAL_TYPEs in C++, must check the mode of the types, not
1833      the precision; they have precision set to match their range, but
1834      may use a wider mode to match an ABI.  If we change modes, we may
1835      wind up with bad conversions.  For INTEGER_TYPEs in C, must check
1836      the precision as well, so as to yield correct results for
1837      bit-field types.  C++ does not have these separate bit-field
1838      types, and producing a signed or unsigned variant of an
1839      ENUMERAL_TYPE may cause other problems as well.  */
1840
1841 #define TYPE_OK(node)                                                       \
1842   (TYPE_MODE (type) == TYPE_MODE (node)                                     \
1843    && (c_dialect_cxx () || TYPE_PRECISION (type) == TYPE_PRECISION (node)))
1844   if (TYPE_OK (signed_char_type_node))
1845     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1846   if (TYPE_OK (integer_type_node))
1847     return unsignedp ? unsigned_type_node : integer_type_node;
1848   if (TYPE_OK (short_integer_type_node))
1849     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1850   if (TYPE_OK (long_integer_type_node))
1851     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1852   if (TYPE_OK (long_long_integer_type_node))
1853     return (unsignedp ? long_long_unsigned_type_node
1854             : long_long_integer_type_node);
1855   if (TYPE_OK (widest_integer_literal_type_node))
1856     return (unsignedp ? widest_unsigned_literal_type_node
1857             : widest_integer_literal_type_node);
1858
1859 #if HOST_BITS_PER_WIDE_INT >= 64
1860   if (TYPE_OK (intTI_type_node))
1861     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
1862 #endif
1863   if (TYPE_OK (intDI_type_node))
1864     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
1865   if (TYPE_OK (intSI_type_node))
1866     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
1867   if (TYPE_OK (intHI_type_node))
1868     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
1869   if (TYPE_OK (intQI_type_node))
1870     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
1871 #undef TYPE_OK
1872
1873   if (c_dialect_cxx ())
1874     return type;
1875   else
1876     return build_nonstandard_integer_type (TYPE_PRECISION (type), unsignedp);
1877 }
1878
1879 /* Build a bit-field integer type for the given WIDTH and UNSIGNEDP.  */
1880
1881 tree
1882 c_build_bitfield_integer_type (unsigned HOST_WIDE_INT width, int unsignedp)
1883 {
1884   /* Extended integer types of the same width as a standard type have
1885      lesser rank, so those of the same width as int promote to int or
1886      unsigned int and are valid for printf formats expecting int or
1887      unsigned int.  To avoid such special cases, avoid creating
1888      extended integer types for bit-fields if a standard integer type
1889      is available.  */
1890   if (width == TYPE_PRECISION (integer_type_node))
1891     return unsignedp ? unsigned_type_node : integer_type_node;
1892   if (width == TYPE_PRECISION (signed_char_type_node))
1893     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
1894   if (width == TYPE_PRECISION (short_integer_type_node))
1895     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
1896   if (width == TYPE_PRECISION (long_integer_type_node))
1897     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
1898   if (width == TYPE_PRECISION (long_long_integer_type_node))
1899     return (unsignedp ? long_long_unsigned_type_node
1900             : long_long_integer_type_node);
1901   return build_nonstandard_integer_type (width, unsignedp);
1902 }
1903
1904 /* The C version of the register_builtin_type langhook.  */
1905
1906 void
1907 c_register_builtin_type (tree type, const char* name)
1908 {
1909   tree decl;
1910
1911   decl = build_decl (TYPE_DECL, get_identifier (name), type);
1912   DECL_ARTIFICIAL (decl) = 1;
1913   if (!TYPE_NAME (type))
1914     TYPE_NAME (type) = decl;
1915   pushdecl (decl);
1916
1917   registered_builtin_types = tree_cons (0, type, registered_builtin_types);
1918 }
1919
1920 \f
1921 /* Return the minimum number of bits needed to represent VALUE in a
1922    signed or unsigned type, UNSIGNEDP says which.  */
1923
1924 unsigned int
1925 min_precision (tree value, int unsignedp)
1926 {
1927   int log;
1928
1929   /* If the value is negative, compute its negative minus 1.  The latter
1930      adjustment is because the absolute value of the largest negative value
1931      is one larger than the largest positive value.  This is equivalent to
1932      a bit-wise negation, so use that operation instead.  */
1933
1934   if (tree_int_cst_sgn (value) < 0)
1935     value = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (value), value);
1936
1937   /* Return the number of bits needed, taking into account the fact
1938      that we need one more bit for a signed than unsigned type.  */
1939
1940   if (integer_zerop (value))
1941     log = 0;
1942   else
1943     log = tree_floor_log2 (value);
1944
1945   return log + 1 + !unsignedp;
1946 }
1947 \f
1948 /* Print an error message for invalid operands to arith operation
1949    CODE.  */
1950
1951 void
1952 binary_op_error (enum tree_code code)
1953 {
1954   const char *opname;
1955
1956   switch (code)
1957     {
1958     case PLUS_EXPR:
1959       opname = "+"; break;
1960     case MINUS_EXPR:
1961       opname = "-"; break;
1962     case MULT_EXPR:
1963       opname = "*"; break;
1964     case MAX_EXPR:
1965       opname = "max"; break;
1966     case MIN_EXPR:
1967       opname = "min"; break;
1968     case EQ_EXPR:
1969       opname = "=="; break;
1970     case NE_EXPR:
1971       opname = "!="; break;
1972     case LE_EXPR:
1973       opname = "<="; break;
1974     case GE_EXPR:
1975       opname = ">="; break;
1976     case LT_EXPR:
1977       opname = "<"; break;
1978     case GT_EXPR:
1979       opname = ">"; break;
1980     case LSHIFT_EXPR:
1981       opname = "<<"; break;
1982     case RSHIFT_EXPR:
1983       opname = ">>"; break;
1984     case TRUNC_MOD_EXPR:
1985     case FLOOR_MOD_EXPR:
1986       opname = "%"; break;
1987     case TRUNC_DIV_EXPR:
1988     case FLOOR_DIV_EXPR:
1989       opname = "/"; break;
1990     case BIT_AND_EXPR:
1991       opname = "&"; break;
1992     case BIT_IOR_EXPR:
1993       opname = "|"; break;
1994     case TRUTH_ANDIF_EXPR:
1995       opname = "&&"; break;
1996     case TRUTH_ORIF_EXPR:
1997       opname = "||"; break;
1998     case BIT_XOR_EXPR:
1999       opname = "^"; break;
2000     default:
2001       gcc_unreachable ();
2002     }
2003   error ("invalid operands to binary %s", opname);
2004 }
2005 \f
2006 /* Subroutine of build_binary_op, used for comparison operations.
2007    See if the operands have both been converted from subword integer types
2008    and, if so, perhaps change them both back to their original type.
2009    This function is also responsible for converting the two operands
2010    to the proper common type for comparison.
2011
2012    The arguments of this function are all pointers to local variables
2013    of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
2014    RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.
2015
2016    If this function returns nonzero, it means that the comparison has
2017    a constant value.  What this function returns is an expression for
2018    that value.  */
2019
2020 tree
2021 shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr,
2022                  enum tree_code *rescode_ptr)
2023 {
2024   tree type;
2025   tree op0 = *op0_ptr;
2026   tree op1 = *op1_ptr;
2027   int unsignedp0, unsignedp1;
2028   int real1, real2;
2029   tree primop0, primop1;
2030   enum tree_code code = *rescode_ptr;
2031
2032   /* Throw away any conversions to wider types
2033      already present in the operands.  */
2034
2035   primop0 = get_narrower (op0, &unsignedp0);
2036   primop1 = get_narrower (op1, &unsignedp1);
2037
2038   /* Handle the case that OP0 does not *contain* a conversion
2039      but it *requires* conversion to FINAL_TYPE.  */
2040
2041   if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
2042     unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0));
2043   if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
2044     unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1));
2045
2046   /* If one of the operands must be floated, we cannot optimize.  */
2047   real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
2048   real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
2049
2050   /* If first arg is constant, swap the args (changing operation
2051      so value is preserved), for canonicalization.  Don't do this if
2052      the second arg is 0.  */
2053
2054   if (TREE_CONSTANT (primop0)
2055       && !integer_zerop (primop1) && !real_zerop (primop1))
2056     {
2057       tree tem = primop0;
2058       int temi = unsignedp0;
2059       primop0 = primop1;
2060       primop1 = tem;
2061       tem = op0;
2062       op0 = op1;
2063       op1 = tem;
2064       *op0_ptr = op0;
2065       *op1_ptr = op1;
2066       unsignedp0 = unsignedp1;
2067       unsignedp1 = temi;
2068       temi = real1;
2069       real1 = real2;
2070       real2 = temi;
2071
2072       switch (code)
2073         {
2074         case LT_EXPR:
2075           code = GT_EXPR;
2076           break;
2077         case GT_EXPR:
2078           code = LT_EXPR;
2079           break;
2080         case LE_EXPR:
2081           code = GE_EXPR;
2082           break;
2083         case GE_EXPR:
2084           code = LE_EXPR;
2085           break;
2086         default:
2087           break;
2088         }
2089       *rescode_ptr = code;
2090     }
2091
2092   /* If comparing an integer against a constant more bits wide,
2093      maybe we can deduce a value of 1 or 0 independent of the data.
2094      Or else truncate the constant now
2095      rather than extend the variable at run time.
2096
2097      This is only interesting if the constant is the wider arg.
2098      Also, it is not safe if the constant is unsigned and the
2099      variable arg is signed, since in this case the variable
2100      would be sign-extended and then regarded as unsigned.
2101      Our technique fails in this case because the lowest/highest
2102      possible unsigned results don't follow naturally from the
2103      lowest/highest possible values of the variable operand.
2104      For just EQ_EXPR and NE_EXPR there is another technique that
2105      could be used: see if the constant can be faithfully represented
2106      in the other operand's type, by truncating it and reextending it
2107      and see if that preserves the constant's value.  */
2108
2109   if (!real1 && !real2
2110       && TREE_CODE (primop1) == INTEGER_CST
2111       && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
2112     {
2113       int min_gt, max_gt, min_lt, max_lt;
2114       tree maxval, minval;
2115       /* 1 if comparison is nominally unsigned.  */
2116       int unsignedp = TYPE_UNSIGNED (*restype_ptr);
2117       tree val;
2118
2119       type = c_common_signed_or_unsigned_type (unsignedp0,
2120                                                TREE_TYPE (primop0));
2121
2122       maxval = TYPE_MAX_VALUE (type);
2123       minval = TYPE_MIN_VALUE (type);
2124
2125       if (unsignedp && !unsignedp0)
2126         *restype_ptr = c_common_signed_type (*restype_ptr);
2127
2128       if (TREE_TYPE (primop1) != *restype_ptr)
2129         {
2130           /* Convert primop1 to target type, but do not introduce
2131              additional overflow.  We know primop1 is an int_cst.  */
2132           tree tmp = build_int_cst_wide (*restype_ptr,
2133                                          TREE_INT_CST_LOW (primop1),
2134                                          TREE_INT_CST_HIGH (primop1));
2135
2136           primop1 = force_fit_type (tmp, 0, TREE_OVERFLOW (primop1),
2137                                     TREE_CONSTANT_OVERFLOW (primop1));
2138         }
2139       if (type != *restype_ptr)
2140         {
2141           minval = convert (*restype_ptr, minval);
2142           maxval = convert (*restype_ptr, maxval);
2143         }
2144
2145       if (unsignedp && unsignedp0)
2146         {
2147           min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
2148           max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
2149           min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
2150           max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
2151         }
2152       else
2153         {
2154           min_gt = INT_CST_LT (primop1, minval);
2155           max_gt = INT_CST_LT (primop1, maxval);
2156           min_lt = INT_CST_LT (minval, primop1);
2157           max_lt = INT_CST_LT (maxval, primop1);
2158         }
2159
2160       val = 0;
2161       /* This used to be a switch, but Genix compiler can't handle that.  */
2162       if (code == NE_EXPR)
2163         {
2164           if (max_lt || min_gt)
2165             val = truthvalue_true_node;
2166         }
2167       else if (code == EQ_EXPR)
2168         {
2169           if (max_lt || min_gt)
2170             val = truthvalue_false_node;
2171         }
2172       else if (code == LT_EXPR)
2173         {
2174           if (max_lt)
2175             val = truthvalue_true_node;
2176           if (!min_lt)
2177             val = truthvalue_false_node;
2178         }
2179       else if (code == GT_EXPR)
2180         {
2181           if (min_gt)
2182             val = truthvalue_true_node;
2183           if (!max_gt)
2184             val = truthvalue_false_node;
2185         }
2186       else if (code == LE_EXPR)
2187         {
2188           if (!max_gt)
2189             val = truthvalue_true_node;
2190           if (min_gt)
2191             val = truthvalue_false_node;
2192         }
2193       else if (code == GE_EXPR)
2194         {
2195           if (!min_lt)
2196             val = truthvalue_true_node;
2197           if (max_lt)
2198             val = truthvalue_false_node;
2199         }
2200
2201       /* If primop0 was sign-extended and unsigned comparison specd,
2202          we did a signed comparison above using the signed type bounds.
2203          But the comparison we output must be unsigned.
2204
2205          Also, for inequalities, VAL is no good; but if the signed
2206          comparison had *any* fixed result, it follows that the
2207          unsigned comparison just tests the sign in reverse
2208          (positive values are LE, negative ones GE).
2209          So we can generate an unsigned comparison
2210          against an extreme value of the signed type.  */
2211
2212       if (unsignedp && !unsignedp0)
2213         {
2214           if (val != 0)
2215             switch (code)
2216               {
2217               case LT_EXPR:
2218               case GE_EXPR:
2219                 primop1 = TYPE_MIN_VALUE (type);
2220                 val = 0;
2221                 break;
2222
2223               case LE_EXPR:
2224               case GT_EXPR:
2225                 primop1 = TYPE_MAX_VALUE (type);
2226                 val = 0;
2227                 break;
2228
2229               default:
2230                 break;
2231               }
2232           type = c_common_unsigned_type (type);
2233         }
2234
2235       if (TREE_CODE (primop0) != INTEGER_CST)
2236         {
2237           if (val == truthvalue_false_node)
2238             warning (0, "comparison is always false due to limited range of data type");
2239           if (val == truthvalue_true_node)
2240             warning (0, "comparison is always true due to limited range of data type");
2241         }
2242
2243       if (val != 0)
2244         {
2245           /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2246           if (TREE_SIDE_EFFECTS (primop0))
2247             return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
2248           return val;
2249         }
2250
2251       /* Value is not predetermined, but do the comparison
2252          in the type of the operand that is not constant.
2253          TYPE is already properly set.  */
2254     }
2255
2256   /* If either arg is decimal float and the other is float, find the
2257      proper common type to use for comparison.  */
2258   else if (real1 && real2
2259            && (DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop0)))
2260                || DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop1)))))
2261     type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
2262
2263   else if (real1 && real2
2264            && (TYPE_PRECISION (TREE_TYPE (primop0))
2265                == TYPE_PRECISION (TREE_TYPE (primop1))))
2266     type = TREE_TYPE (primop0);
2267
2268   /* If args' natural types are both narrower than nominal type
2269      and both extend in the same manner, compare them
2270      in the type of the wider arg.
2271      Otherwise must actually extend both to the nominal
2272      common type lest different ways of extending
2273      alter the result.
2274      (eg, (short)-1 == (unsigned short)-1  should be 0.)  */
2275
2276   else if (unsignedp0 == unsignedp1 && real1 == real2
2277            && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
2278            && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
2279     {
2280       type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
2281       type = c_common_signed_or_unsigned_type (unsignedp0
2282                                                || TYPE_UNSIGNED (*restype_ptr),
2283                                                type);
2284       /* Make sure shorter operand is extended the right way
2285          to match the longer operand.  */
2286       primop0
2287         = convert (c_common_signed_or_unsigned_type (unsignedp0,
2288                                                      TREE_TYPE (primop0)),
2289                    primop0);
2290       primop1
2291         = convert (c_common_signed_or_unsigned_type (unsignedp1,
2292                                                      TREE_TYPE (primop1)),
2293                    primop1);
2294     }
2295   else
2296     {
2297       /* Here we must do the comparison on the nominal type
2298          using the args exactly as we received them.  */
2299       type = *restype_ptr;
2300       primop0 = op0;
2301       primop1 = op1;
2302
2303       if (!real1 && !real2 && integer_zerop (primop1)
2304           && TYPE_UNSIGNED (*restype_ptr))
2305         {
2306           tree value = 0;
2307           switch (code)
2308             {
2309             case GE_EXPR:
2310               /* All unsigned values are >= 0, so we warn if extra warnings
2311                  are requested.  However, if OP0 is a constant that is
2312                  >= 0, the signedness of the comparison isn't an issue,
2313                  so suppress the warning.  */
2314               if (extra_warnings && !in_system_header
2315                   && !(TREE_CODE (primop0) == INTEGER_CST
2316                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
2317                                                    primop0))))
2318                 warning (0, "comparison of unsigned expression >= 0 is always true");
2319               value = truthvalue_true_node;
2320               break;
2321
2322             case LT_EXPR:
2323               if (extra_warnings && !in_system_header
2324                   && !(TREE_CODE (primop0) == INTEGER_CST
2325                        && !TREE_OVERFLOW (convert (c_common_signed_type (type),
2326                                                    primop0))))
2327                 warning (0, "comparison of unsigned expression < 0 is always false");
2328               value = truthvalue_false_node;
2329               break;
2330
2331             default:
2332               break;
2333             }
2334
2335           if (value != 0)
2336             {
2337               /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
2338               if (TREE_SIDE_EFFECTS (primop0))
2339                 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2340                                primop0, value);
2341               return value;
2342             }
2343         }
2344     }
2345
2346   *op0_ptr = convert (type, primop0);
2347   *op1_ptr = convert (type, primop1);
2348
2349   *restype_ptr = truthvalue_type_node;
2350
2351   return 0;
2352 }
2353 \f
2354 /* Return a tree for the sum or difference (RESULTCODE says which)
2355    of pointer PTROP and integer INTOP.  */
2356
2357 tree
2358 pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
2359 {
2360   tree size_exp;
2361
2362   /* The result is a pointer of the same type that is being added.  */
2363
2364   tree result_type = TREE_TYPE (ptrop);
2365
2366   if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
2367     {
2368       if (pedantic || warn_pointer_arith)
2369         pedwarn ("pointer of type %<void *%> used in arithmetic");
2370       size_exp = integer_one_node;
2371     }
2372   else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE)
2373     {
2374       if (pedantic || warn_pointer_arith)
2375         pedwarn ("pointer to a function used in arithmetic");
2376       size_exp = integer_one_node;
2377     }
2378   else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE)
2379     {
2380       if (pedantic || warn_pointer_arith)
2381         pedwarn ("pointer to member function used in arithmetic");
2382       size_exp = integer_one_node;
2383     }
2384   else
2385     size_exp = size_in_bytes (TREE_TYPE (result_type));
2386
2387   /* If what we are about to multiply by the size of the elements
2388      contains a constant term, apply distributive law
2389      and multiply that constant term separately.
2390      This helps produce common subexpressions.  */
2391
2392   if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
2393       && !TREE_CONSTANT (intop)
2394       && TREE_CONSTANT (TREE_OPERAND (intop, 1))
2395       && TREE_CONSTANT (size_exp)
2396       /* If the constant comes from pointer subtraction,
2397          skip this optimization--it would cause an error.  */
2398       && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
2399       /* If the constant is unsigned, and smaller than the pointer size,
2400          then we must skip this optimization.  This is because it could cause
2401          an overflow error if the constant is negative but INTOP is not.  */
2402       && (!TYPE_UNSIGNED (TREE_TYPE (intop))
2403           || (TYPE_PRECISION (TREE_TYPE (intop))
2404               == TYPE_PRECISION (TREE_TYPE (ptrop)))))
2405     {
2406       enum tree_code subcode = resultcode;
2407       tree int_type = TREE_TYPE (intop);
2408       if (TREE_CODE (intop) == MINUS_EXPR)
2409         subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
2410       /* Convert both subexpression types to the type of intop,
2411          because weird cases involving pointer arithmetic
2412          can result in a sum or difference with different type args.  */
2413       ptrop = build_binary_op (subcode, ptrop,
2414                                convert (int_type, TREE_OPERAND (intop, 1)), 1);
2415       intop = convert (int_type, TREE_OPERAND (intop, 0));
2416     }
2417
2418   /* Convert the integer argument to a type the same size as sizetype
2419      so the multiply won't overflow spuriously.  */
2420
2421   if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype)
2422       || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype))
2423     intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype),
2424                                              TYPE_UNSIGNED (sizetype)), intop);
2425
2426   /* Replace the integer argument with a suitable product by the object size.
2427      Do this multiplication as signed, then convert to the appropriate
2428      pointer type (actually unsigned integral).  */
2429
2430   intop = convert (result_type,
2431                    build_binary_op (MULT_EXPR, intop,
2432                                     convert (TREE_TYPE (intop), size_exp), 1));
2433
2434   /* Create the sum or difference.  */
2435   return fold_build2 (resultcode, result_type, ptrop, intop);
2436 }
2437 \f
2438 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
2439    or for an `if' or `while' statement or ?..: exp.  It should already
2440    have been validated to be of suitable type; otherwise, a bad
2441    diagnostic may result.
2442
2443    This preparation consists of taking the ordinary
2444    representation of an expression expr and producing a valid tree
2445    boolean expression describing whether expr is nonzero.  We could
2446    simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1),
2447    but we optimize comparisons, &&, ||, and !.
2448
2449    The resulting type should always be `truthvalue_type_node'.  */
2450
2451 tree
2452 c_common_truthvalue_conversion (tree expr)
2453 {
2454   switch (TREE_CODE (expr))
2455     {
2456     case EQ_EXPR:   case NE_EXPR:   case UNEQ_EXPR: case LTGT_EXPR:
2457     case LE_EXPR:   case GE_EXPR:   case LT_EXPR:   case GT_EXPR:
2458     case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR:
2459     case ORDERED_EXPR: case UNORDERED_EXPR:
2460       if (TREE_TYPE (expr) == truthvalue_type_node)
2461         return expr;
2462       return build2 (TREE_CODE (expr), truthvalue_type_node,
2463                      TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1));
2464
2465     case TRUTH_ANDIF_EXPR:
2466     case TRUTH_ORIF_EXPR:
2467     case TRUTH_AND_EXPR:
2468     case TRUTH_OR_EXPR:
2469     case TRUTH_XOR_EXPR:
2470       if (TREE_TYPE (expr) == truthvalue_type_node)
2471         return expr;
2472       return build2 (TREE_CODE (expr), truthvalue_type_node,
2473                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)),
2474                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)));
2475
2476     case TRUTH_NOT_EXPR:
2477       if (TREE_TYPE (expr) == truthvalue_type_node)
2478         return expr;
2479       return build1 (TREE_CODE (expr), truthvalue_type_node,
2480                  c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)));
2481
2482     case ERROR_MARK:
2483       return expr;
2484
2485     case INTEGER_CST:
2486       /* Avoid integer_zerop to ignore TREE_CONSTANT_OVERFLOW.  */
2487       return (TREE_INT_CST_LOW (expr) != 0 || TREE_INT_CST_HIGH (expr) != 0)
2488              ? truthvalue_true_node
2489              : truthvalue_false_node;
2490
2491     case REAL_CST:
2492       return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0)
2493              ? truthvalue_true_node
2494              : truthvalue_false_node;
2495
2496     case FUNCTION_DECL:
2497       expr = build_unary_op (ADDR_EXPR, expr, 0);
2498       /* Fall through.  */
2499
2500     case ADDR_EXPR:
2501       {
2502         tree inner = TREE_OPERAND (expr, 0);
2503         if (DECL_P (inner)
2504             && (TREE_CODE (inner) == PARM_DECL || !DECL_WEAK (inner)))
2505           {
2506             /* Common Ada/Pascal programmer's mistake.  We always warn
2507                about this since it is so bad.  */
2508             warning (OPT_Walways_true, "the address of %qD, will always evaluate as %<true%>",
2509                      inner);
2510             return truthvalue_true_node;
2511           }
2512
2513         /* If we are taking the address of an external decl, it might be
2514            zero if it is weak, so we cannot optimize.  */
2515         if (DECL_P (inner)
2516             && DECL_EXTERNAL (inner))
2517           break;
2518
2519         if (TREE_SIDE_EFFECTS (inner))
2520           return build2 (COMPOUND_EXPR, truthvalue_type_node,
2521                          inner, truthvalue_true_node);
2522         else
2523           return truthvalue_true_node;
2524       }
2525
2526     case COMPLEX_EXPR:
2527       return build_binary_op ((TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
2528                                ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
2529                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)),
2530                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
2531                               0);
2532
2533     case NEGATE_EXPR:
2534     case ABS_EXPR:
2535     case FLOAT_EXPR:
2536       /* These don't change whether an object is nonzero or zero.  */
2537       return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
2538
2539     case LROTATE_EXPR:
2540     case RROTATE_EXPR:
2541       /* These don't change whether an object is zero or nonzero, but
2542          we can't ignore them if their second arg has side-effects.  */
2543       if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2544         return build2 (COMPOUND_EXPR, truthvalue_type_node,
2545                        TREE_OPERAND (expr, 1),
2546                        c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)));
2547       else
2548         return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
2549
2550     case COND_EXPR:
2551       /* Distribute the conversion into the arms of a COND_EXPR.  */
2552       return fold_build3 (COND_EXPR, truthvalue_type_node,
2553                 TREE_OPERAND (expr, 0),
2554                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
2555                 c_common_truthvalue_conversion (TREE_OPERAND (expr, 2)));
2556
2557     case CONVERT_EXPR:
2558     case NOP_EXPR:
2559       /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
2560          since that affects how `default_conversion' will behave.  */
2561       if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
2562           || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
2563         break;
2564       /* If this is widening the argument, we can ignore it.  */
2565       if (TYPE_PRECISION (TREE_TYPE (expr))
2566           >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
2567         return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
2568       break;
2569
2570     case MODIFY_EXPR:
2571       if (!TREE_NO_WARNING (expr))
2572         warning (OPT_Wparentheses,
2573                  "suggest parentheses around assignment used as truth value");
2574       break;
2575
2576     default:
2577       break;
2578     }
2579
2580   if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
2581     {
2582       tree t = save_expr (expr);
2583       return (build_binary_op
2584               ((TREE_SIDE_EFFECTS (expr)
2585                 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
2586         c_common_truthvalue_conversion (build_unary_op (REALPART_EXPR, t, 0)),
2587         c_common_truthvalue_conversion (build_unary_op (IMAGPART_EXPR, t, 0)),
2588                0));
2589     }
2590
2591   return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
2592 }
2593 \f
2594 static void def_builtin_1  (enum built_in_function fncode,
2595                             const char *name,
2596                             enum built_in_class fnclass,
2597                             tree fntype, tree libtype,
2598                             bool both_p, bool fallback_p, bool nonansi_p,
2599                             tree fnattrs, bool implicit_p);
2600
2601 /* Make a variant type in the proper way for C/C++, propagating qualifiers
2602    down to the element type of an array.  */
2603
2604 tree
2605 c_build_qualified_type (tree type, int type_quals)
2606 {
2607   if (type == error_mark_node)
2608     return type;
2609
2610   if (TREE_CODE (type) == ARRAY_TYPE)
2611     {
2612       tree t;
2613       tree element_type = c_build_qualified_type (TREE_TYPE (type),
2614                                                   type_quals);
2615
2616       /* See if we already have an identically qualified type.  */
2617       for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
2618         {
2619           if (TYPE_QUALS (strip_array_types (t)) == type_quals
2620               && TYPE_NAME (t) == TYPE_NAME (type)
2621               && TYPE_CONTEXT (t) == TYPE_CONTEXT (type)
2622               && attribute_list_equal (TYPE_ATTRIBUTES (t),
2623                                        TYPE_ATTRIBUTES (type)))
2624             break;
2625         }
2626       if (!t)
2627         {
2628           t = build_variant_type_copy (type);
2629           TREE_TYPE (t) = element_type;
2630         }
2631       return t;
2632     }
2633
2634   /* A restrict-qualified pointer type must be a pointer to object or
2635      incomplete type.  Note that the use of POINTER_TYPE_P also allows
2636      REFERENCE_TYPEs, which is appropriate for C++.  */
2637   if ((type_quals & TYPE_QUAL_RESTRICT)
2638       && (!POINTER_TYPE_P (type)
2639           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type))))
2640     {
2641       error ("invalid use of %<restrict%>");
2642       type_quals &= ~TYPE_QUAL_RESTRICT;
2643     }
2644
2645   return build_qualified_type (type, type_quals);
2646 }
2647
2648 /* Apply the TYPE_QUALS to the new DECL.  */
2649
2650 void
2651 c_apply_type_quals_to_decl (int type_quals, tree decl)
2652 {
2653   tree type = TREE_TYPE (decl);
2654
2655   if (type == error_mark_node)
2656     return;
2657
2658   if (((type_quals & TYPE_QUAL_CONST)
2659        || (type && TREE_CODE (type) == REFERENCE_TYPE))
2660       /* An object declared 'const' is only readonly after it is
2661          initialized.  We don't have any way of expressing this currently,
2662          so we need to be conservative and unset TREE_READONLY for types
2663          with constructors.  Otherwise aliasing code will ignore stores in
2664          an inline constructor.  */
2665       && !(type && TYPE_NEEDS_CONSTRUCTING (type)))
2666     TREE_READONLY (decl) = 1;
2667   if (type_quals & TYPE_QUAL_VOLATILE)
2668     {
2669       TREE_SIDE_EFFECTS (decl) = 1;
2670       TREE_THIS_VOLATILE (decl) = 1;
2671     }
2672   if (type_quals & TYPE_QUAL_RESTRICT)
2673     {
2674       while (type && TREE_CODE (type) == ARRAY_TYPE)
2675         /* Allow 'restrict' on arrays of pointers.
2676            FIXME currently we just ignore it.  */
2677         type = TREE_TYPE (type);
2678       if (!type
2679           || !POINTER_TYPE_P (type)
2680           || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))
2681         error ("invalid use of %<restrict%>");
2682       else if (flag_strict_aliasing && type == TREE_TYPE (decl))
2683         /* Indicate we need to make a unique alias set for this pointer.
2684            We can't do it here because it might be pointing to an
2685            incomplete type.  */
2686         DECL_POINTER_ALIAS_SET (decl) = -2;
2687     }
2688 }
2689
2690 /* Hash function for the problem of multiple type definitions in
2691    different files.  This must hash all types that will compare
2692    equal via comptypes to the same value.  In practice it hashes
2693    on some of the simple stuff and leaves the details to comptypes.  */
2694
2695 static hashval_t
2696 c_type_hash (const void *p)
2697 {
2698   int i = 0;
2699   int shift, size;
2700   tree t = (tree) p;
2701   tree t2;
2702   switch (TREE_CODE (t))
2703     {
2704     /* For pointers, hash on pointee type plus some swizzling.  */
2705     case POINTER_TYPE:
2706       return c_type_hash (TREE_TYPE (t)) ^ 0x3003003;
2707     /* Hash on number of elements and total size.  */
2708     case ENUMERAL_TYPE:
2709       shift = 3;
2710       t2 = TYPE_VALUES (t);
2711       break;
2712     case RECORD_TYPE:
2713       shift = 0;
2714       t2 = TYPE_FIELDS (t);
2715       break;
2716     case QUAL_UNION_TYPE:
2717       shift = 1;
2718       t2 = TYPE_FIELDS (t);
2719       break;
2720     case UNION_TYPE:
2721       shift = 2;
2722       t2 = TYPE_FIELDS (t);
2723       break;
2724     default:
2725       gcc_unreachable ();
2726     }
2727   for (; t2; t2 = TREE_CHAIN (t2))
2728     i++;
2729   size = TREE_INT_CST_LOW (TYPE_SIZE (t));
2730   return ((size << 24) | (i << shift));
2731 }
2732
2733 static GTY((param_is (union tree_node))) htab_t type_hash_table;
2734
2735 /* Return the typed-based alias set for T, which may be an expression
2736    or a type.  Return -1 if we don't do anything special.  */
2737
2738 HOST_WIDE_INT
2739 c_common_get_alias_set (tree t)
2740 {
2741   tree u;
2742   PTR *slot;
2743
2744   /* Permit type-punning when accessing a union, provided the access
2745      is directly through the union.  For example, this code does not
2746      permit taking the address of a union member and then storing
2747      through it.  Even the type-punning allowed here is a GCC
2748      extension, albeit a common and useful one; the C standard says
2749      that such accesses have implementation-defined behavior.  */
2750   for (u = t;
2751        TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
2752        u = TREE_OPERAND (u, 0))
2753     if (TREE_CODE (u) == COMPONENT_REF
2754         && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
2755       return 0;
2756
2757   /* That's all the expressions we handle specially.  */
2758   if (!TYPE_P (t))
2759     return -1;
2760
2761   /* The C standard guarantees that any object may be accessed via an
2762      lvalue that has character type.  */
2763   if (t == char_type_node
2764       || t == signed_char_type_node
2765       || t == unsigned_char_type_node)
2766     return 0;
2767
2768   /* If it has the may_alias attribute, it can alias anything.  */
2769   if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (t)))
2770     return 0;
2771
2772   /* The C standard specifically allows aliasing between signed and
2773      unsigned variants of the same type.  We treat the signed
2774      variant as canonical.  */
2775   if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t))
2776     {
2777       tree t1 = c_common_signed_type (t);
2778
2779       /* t1 == t can happen for boolean nodes which are always unsigned.  */
2780       if (t1 != t)
2781         return get_alias_set (t1);
2782     }
2783   else if (POINTER_TYPE_P (t))
2784     {
2785       tree t1;
2786
2787       /* Unfortunately, there is no canonical form of a pointer type.
2788          In particular, if we have `typedef int I', then `int *', and
2789          `I *' are different types.  So, we have to pick a canonical
2790          representative.  We do this below.
2791
2792          Technically, this approach is actually more conservative that
2793          it needs to be.  In particular, `const int *' and `int *'
2794          should be in different alias sets, according to the C and C++
2795          standard, since their types are not the same, and so,
2796          technically, an `int **' and `const int **' cannot point at
2797          the same thing.
2798
2799          But, the standard is wrong.  In particular, this code is
2800          legal C++:
2801
2802             int *ip;
2803             int **ipp = &ip;
2804             const int* const* cipp = ipp;
2805
2806          And, it doesn't make sense for that to be legal unless you
2807          can dereference IPP and CIPP.  So, we ignore cv-qualifiers on
2808          the pointed-to types.  This issue has been reported to the
2809          C++ committee.  */
2810       t1 = build_type_no_quals (t);
2811       if (t1 != t)
2812         return get_alias_set (t1);
2813     }
2814
2815   /* Handle the case of multiple type nodes referring to "the same" type,
2816      which occurs with IMA.  These share an alias set.  FIXME:  Currently only
2817      C90 is handled.  (In C99 type compatibility is not transitive, which
2818      complicates things mightily. The alias set splay trees can theoretically
2819      represent this, but insertion is tricky when you consider all the
2820      different orders things might arrive in.) */
2821
2822   if (c_language != clk_c || flag_isoc99)
2823     return -1;
2824
2825   /* Save time if there's only one input file.  */
2826   if (num_in_fnames == 1)
2827     return -1;
2828
2829   /* Pointers need special handling if they point to any type that
2830      needs special handling (below).  */
2831   if (TREE_CODE (t) == POINTER_TYPE)
2832     {
2833       tree t2;
2834       /* Find bottom type under any nested POINTERs.  */
2835       for (t2 = TREE_TYPE (t);
2836      TREE_CODE (t2) == POINTER_TYPE;
2837      t2 = TREE_TYPE (t2))
2838   ;
2839       if (TREE_CODE (t2) != RECORD_TYPE
2840     && TREE_CODE (t2) != ENUMERAL_TYPE
2841     && TREE_CODE (t2) != QUAL_UNION_TYPE
2842     && TREE_CODE (t2) != UNION_TYPE)
2843   return -1;
2844       if (TYPE_SIZE (t2) == 0)
2845   return -1;
2846     }
2847   /* These are the only cases that need special handling.  */
2848   if (TREE_CODE (t) != RECORD_TYPE
2849       && TREE_CODE (t) != ENUMERAL_TYPE
2850       && TREE_CODE (t) != QUAL_UNION_TYPE
2851       && TREE_CODE (t) != UNION_TYPE
2852       && TREE_CODE (t) != POINTER_TYPE)
2853     return -1;
2854   /* Undefined? */
2855   if (TYPE_SIZE (t) == 0)
2856     return -1;
2857
2858   /* Look up t in hash table.  Only one of the compatible types within each
2859      alias set is recorded in the table.  */
2860   if (!type_hash_table)
2861     type_hash_table = htab_create_ggc (1021, c_type_hash,
2862             (htab_eq) lang_hooks.types_compatible_p,
2863             NULL);
2864   slot = htab_find_slot (type_hash_table, t, INSERT);
2865   if (*slot != NULL)
2866     {
2867       TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot);
2868       return TYPE_ALIAS_SET ((tree)*slot);
2869     }
2870   else
2871     /* Our caller will assign and record (in t) a new alias set; all we need
2872        to do is remember t in the hash table.  */
2873     *slot = t;
2874
2875   return -1;
2876 }
2877 \f
2878 /* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where the
2879    second parameter indicates which OPERATOR is being applied.  The COMPLAIN
2880    flag controls whether we should diagnose possibly ill-formed
2881    constructs or not.  */
2882
2883 tree
2884 c_sizeof_or_alignof_type (tree type, bool is_sizeof, int complain)
2885 {
2886   const char *op_name;
2887   tree value = NULL;
2888   enum tree_code type_code = TREE_CODE (type);
2889
2890   op_name = is_sizeof ? "sizeof" : "__alignof__";
2891
2892   if (type_code == FUNCTION_TYPE)
2893     {
2894       if (is_sizeof)
2895         {
2896           if (complain && (pedantic || warn_pointer_arith))
2897             pedwarn ("invalid application of %<sizeof%> to a function type");
2898           value = size_one_node;
2899         }
2900       else
2901         value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);
2902     }
2903   else if (type_code == VOID_TYPE || type_code == ERROR_MARK)
2904     {
2905       if (type_code == VOID_TYPE
2906           && complain && (pedantic || warn_pointer_arith))
2907         pedwarn ("invalid application of %qs to a void type", op_name);
2908       value = size_one_node;
2909     }
2910   else if (!COMPLETE_TYPE_P (type))
2911     {
2912       if (complain)
2913         error ("invalid application of %qs to incomplete type %qT ",
2914                op_name, type);
2915       value = size_zero_node;
2916     }
2917   else
2918     {
2919       if (is_sizeof)
2920         /* Convert in case a char is more than one unit.  */
2921         value = size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
2922                             size_int (TYPE_PRECISION (char_type_node)
2923                                       / BITS_PER_UNIT));
2924       else
2925         value = size_int (TYPE_ALIGN_UNIT (type));
2926     }
2927
2928   /* VALUE will have an integer type with TYPE_IS_SIZETYPE set.
2929      TYPE_IS_SIZETYPE means that certain things (like overflow) will
2930      never happen.  However, this node should really have type
2931      `size_t', which is just a typedef for an ordinary integer type.  */
2932   value = fold_convert (size_type_node, value);
2933   gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value)));
2934
2935   return value;
2936 }
2937
2938 /* Implement the __alignof keyword: Return the minimum required
2939    alignment of EXPR, measured in bytes.  For VAR_DECL's and
2940    FIELD_DECL's return DECL_ALIGN (which can be set from an
2941    "aligned" __attribute__ specification).  */
2942
2943 tree
2944 c_alignof_expr (tree expr)
2945 {
2946   tree t;
2947
2948   if (TREE_CODE (expr) == VAR_DECL)
2949     t = size_int (DECL_ALIGN_UNIT (expr));
2950
2951   else if (TREE_CODE (expr) == COMPONENT_REF
2952            && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1)))
2953     {
2954       error ("%<__alignof%> applied to a bit-field");
2955       t = size_one_node;
2956     }
2957   else if (TREE_CODE (expr) == COMPONENT_REF
2958            && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL)
2959     t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1)));
2960
2961   else if (TREE_CODE (expr) == INDIRECT_REF)
2962     {
2963       tree t = TREE_OPERAND (expr, 0);
2964       tree best = t;
2965       int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
2966
2967       while ((TREE_CODE (t) == NOP_EXPR || TREE_CODE (t) == CONVERT_EXPR)
2968              && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE)
2969         {
2970           int thisalign;
2971
2972           t = TREE_OPERAND (t, 0);
2973           thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
2974           if (thisalign > bestalign)
2975             best = t, bestalign = thisalign;
2976         }
2977       return c_alignof (TREE_TYPE (TREE_TYPE (best)));
2978     }
2979   else
2980     return c_alignof (TREE_TYPE (expr));
2981
2982   return fold_convert (size_type_node, t);
2983 }
2984 \f
2985 /* Handle C and C++ default attributes.  */
2986
2987 enum built_in_attribute
2988 {
2989 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
2990 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
2991 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
2992 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
2993 #include "builtin-attrs.def"
2994 #undef DEF_ATTR_NULL_TREE
2995 #undef DEF_ATTR_INT
2996 #undef DEF_ATTR_IDENT
2997 #undef DEF_ATTR_TREE_LIST
2998   ATTR_LAST
2999 };
3000
3001 static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
3002
3003 static void c_init_attributes (void);
3004
3005 enum c_builtin_type
3006 {
3007 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
3008 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
3009 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
3010 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
3011 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
3012 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
3013 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
3014 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) NAME,
3015 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7) NAME,
3016 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
3017 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
3018 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
3019 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
3020 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
3021 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \
3022   NAME,
3023 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
3024 #include "builtin-types.def"
3025 #undef DEF_PRIMITIVE_TYPE
3026 #undef DEF_FUNCTION_TYPE_0
3027 #undef DEF_FUNCTION_TYPE_1
3028 #undef DEF_FUNCTION_TYPE_2
3029 #undef DEF_FUNCTION_TYPE_3
3030 #undef DEF_FUNCTION_TYPE_4
3031 #undef DEF_FUNCTION_TYPE_5
3032 #undef DEF_FUNCTION_TYPE_6
3033 #undef DEF_FUNCTION_TYPE_7
3034 #undef DEF_FUNCTION_TYPE_VAR_0
3035 #undef DEF_FUNCTION_TYPE_VAR_1
3036 #undef DEF_FUNCTION_TYPE_VAR_2
3037 #undef DEF_FUNCTION_TYPE_VAR_3
3038 #undef DEF_FUNCTION_TYPE_VAR_4
3039 #undef DEF_FUNCTION_TYPE_VAR_5
3040 #undef DEF_POINTER_TYPE
3041   BT_LAST
3042 };
3043
3044 typedef enum c_builtin_type builtin_type;
3045
3046 /* A temporary array for c_common_nodes_and_builtins.  Used in
3047    communication with def_fn_type.  */
3048 static tree builtin_types[(int) BT_LAST + 1];
3049
3050 /* A helper function for c_common_nodes_and_builtins.  Build function type
3051    for DEF with return type RET and N arguments.  If VAR is true, then the
3052    function should be variadic after those N arguments.
3053
3054    Takes special care not to ICE if any of the types involved are
3055    error_mark_node, which indicates that said type is not in fact available
3056    (see builtin_type_for_size).  In which case the function type as a whole
3057    should be error_mark_node.  */
3058
3059 static void
3060 def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...)
3061 {
3062   tree args = NULL, t;
3063   va_list list;
3064   int i;
3065
3066   va_start (list, n);
3067   for (i = 0; i < n; ++i)
3068     {
3069       builtin_type a = va_arg (list, builtin_type);
3070       t = builtin_types[a];
3071       if (t == error_mark_node)
3072         goto egress;
3073       args = tree_cons (NULL_TREE, t, args);
3074     }
3075   va_end (list);
3076
3077   args = nreverse (args);
3078   if (!var)
3079     args = chainon (args, void_list_node);
3080
3081   t = builtin_types[ret];
3082   if (t == error_mark_node)
3083     goto egress;
3084   t = build_function_type (t, args);
3085
3086  egress:
3087   builtin_types[def] = t;
3088 }
3089
3090 /* Build tree nodes and builtin functions common to both C and C++ language
3091    frontends.  */
3092
3093 void
3094 c_common_nodes_and_builtins (void)
3095 {
3096   int wchar_type_size;
3097   tree array_domain_type;
3098   tree va_list_ref_type_node;
3099   tree va_list_arg_type_node;
3100
3101   /* Define `int' and `char' first so that dbx will output them first.  */
3102   record_builtin_type (RID_INT, NULL, integer_type_node);
3103   record_builtin_type (RID_CHAR, "char", char_type_node);
3104
3105   /* `signed' is the same as `int'.  FIXME: the declarations of "signed",
3106      "unsigned long", "long long unsigned" and "unsigned short" were in C++
3107      but not C.  Are the conditionals here needed?  */
3108   if (c_dialect_cxx ())
3109     record_builtin_type (RID_SIGNED, NULL, integer_type_node);
3110   record_builtin_type (RID_LONG, "long int", long_integer_type_node);
3111   record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
3112   record_builtin_type (RID_MAX, "long unsigned int",
3113                        long_unsigned_type_node);
3114   if (c_dialect_cxx ())
3115     record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
3116   record_builtin_type (RID_MAX, "long long int",
3117                        long_long_integer_type_node);
3118   record_builtin_type (RID_MAX, "long long unsigned int",
3119                        long_long_unsigned_type_node);
3120   if (c_dialect_cxx ())
3121     record_builtin_type (RID_MAX, "long long unsigned",
3122                          long_long_unsigned_type_node);
3123   record_builtin_type (RID_SHORT, "short int", short_integer_type_node);
3124   record_builtin_type (RID_MAX, "short unsigned int",
3125                        short_unsigned_type_node);
3126   if (c_dialect_cxx ())
3127     record_builtin_type (RID_MAX, "unsigned short",
3128                          short_unsigned_type_node);
3129
3130   /* Define both `signed char' and `unsigned char'.  */
3131   record_builtin_type (RID_MAX, "signed char", signed_char_type_node);
3132   record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node);
3133
3134   /* These are types that c_common_type_for_size and
3135      c_common_type_for_mode use.  */
3136   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3137                                          intQI_type_node));
3138   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3139                                          intHI_type_node));
3140   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3141                                          intSI_type_node));
3142   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3143                                          intDI_type_node));
3144 #if HOST_BITS_PER_WIDE_INT >= 64
3145   if (targetm.scalar_mode_supported_p (TImode))
3146     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3147                                            get_identifier ("__int128_t"),
3148                                            intTI_type_node));
3149 #endif
3150   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3151                                          unsigned_intQI_type_node));
3152   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3153                                          unsigned_intHI_type_node));
3154   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3155                                          unsigned_intSI_type_node));
3156   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3157                                          unsigned_intDI_type_node));
3158 #if HOST_BITS_PER_WIDE_INT >= 64
3159   if (targetm.scalar_mode_supported_p (TImode))
3160     lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3161                                            get_identifier ("__uint128_t"),
3162                                            unsigned_intTI_type_node));
3163 #endif
3164
3165   /* Create the widest literal types.  */
3166   widest_integer_literal_type_node
3167     = make_signed_type (HOST_BITS_PER_WIDE_INT * 2);
3168   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3169                                          widest_integer_literal_type_node));
3170
3171   widest_unsigned_literal_type_node
3172     = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2);
3173   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE,
3174                                          widest_unsigned_literal_type_node));
3175
3176   /* `unsigned long' is the standard type for sizeof.
3177      Note that stddef.h uses `unsigned long',
3178      and this must agree, even if long and int are the same size.  */
3179   size_type_node =
3180     TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE)));
3181   signed_size_type_node = c_common_signed_type (size_type_node);
3182   set_sizetype (size_type_node);
3183
3184   pid_type_node =
3185     TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE)));
3186
3187   build_common_tree_nodes_2 (flag_short_double);
3188
3189   record_builtin_type (RID_FLOAT, NULL, float_type_node);
3190   record_builtin_type (RID_DOUBLE, NULL, double_type_node);
3191   record_builtin_type (RID_MAX, "long double", long_double_type_node);
3192
3193   /* Only supported decimal floating point extension if the target
3194      actually supports underlying modes. */
3195   if (targetm.scalar_mode_supported_p (SDmode)
3196       && targetm.scalar_mode_supported_p (DDmode)
3197       && targetm.scalar_mode_supported_p (TDmode))
3198     {
3199       record_builtin_type (RID_DFLOAT32, NULL, dfloat32_type_node);
3200       record_builtin_type (RID_DFLOAT64, NULL, dfloat64_type_node);
3201       record_builtin_type (RID_DFLOAT128, NULL, dfloat128_type_node);
3202     }
3203
3204   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3205                                          get_identifier ("complex int"),
3206                                          complex_integer_type_node));
3207   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3208                                          get_identifier ("complex float"),
3209                                          complex_float_type_node));
3210   lang_hooks.decls.pushdecl (build_decl (TYPE_DECL,
3211                                          get_identifier ("complex double"),
3212                                          complex_double_type_node));
3213   lang_hooks.decls.pushdecl
3214     (build_decl (TYPE_DECL, get_identifier ("complex long double"),
3215                  complex_long_double_type_node));
3216
3217   if (c_dialect_cxx ())
3218     /* For C++, make fileptr_type_node a distinct void * type until
3219        FILE type is defined.  */
3220     fileptr_type_node = build_variant_type_copy (ptr_type_node);
3221
3222   record_builtin_type (RID_VOID, NULL, void_type_node);
3223
3224   /* This node must not be shared.  */
3225   void_zero_node = make_node (INTEGER_CST);
3226   TREE_TYPE (void_zero_node) = void_type_node;
3227
3228   void_list_node = build_void_list_node ();
3229
3230   /* Make a type to be the domain of a few array types
3231      whose domains don't really matter.
3232      200 is small enough that it always fits in size_t
3233      and large enough that it can hold most function names for the
3234      initializations of __FUNCTION__ and __PRETTY_FUNCTION__.  */
3235   array_domain_type = build_index_type (size_int (200));
3236
3237   /* Make a type for arrays of characters.
3238      With luck nothing will ever really depend on the length of this
3239      array type.  */
3240   char_array_type_node
3241     = build_array_type (char_type_node, array_domain_type);
3242
3243   /* Likewise for arrays of ints.  */
3244   int_array_type_node
3245     = build_array_type (integer_type_node, array_domain_type);
3246
3247   string_type_node = build_pointer_type (char_type_node);
3248   const_string_type_node
3249     = build_pointer_type (build_qualified_type
3250                           (char_type_node, TYPE_QUAL_CONST));
3251
3252   /* This is special for C++ so functions can be overloaded.  */
3253   wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE);
3254   wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node));
3255   wchar_type_size = TYPE_PRECISION (wchar_type_node);
3256   if (c_dialect_cxx ())
3257     {
3258       if (TYPE_UNSIGNED (wchar_type_node))
3259         wchar_type_node = make_unsigned_type (wchar_type_size);
3260       else
3261         wchar_type_node = make_signed_type (wchar_type_size);
3262       record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node);
3263     }
3264   else
3265     {
3266       signed_wchar_type_node = c_common_signed_type (wchar_type_node);
3267       unsigned_wchar_type_node = c_common_unsigned_type (wchar_type_node);
3268     }
3269
3270   /* This is for wide string constants.  */
3271   wchar_array_type_node
3272     = build_array_type (wchar_type_node, array_domain_type);
3273
3274   wint_type_node =
3275     TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE)));
3276
3277   intmax_type_node =
3278     TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE)));
3279   uintmax_type_node =
3280     TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE)));
3281
3282   default_function_type = build_function_type (integer_type_node, NULL_TREE);
3283   ptrdiff_type_node
3284     = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE)));
3285   unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node);
3286
3287   lang_hooks.decls.pushdecl
3288     (build_decl (TYPE_DECL, get_identifier ("__builtin_va_list"),
3289                  va_list_type_node));
3290
3291   if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
3292     {
3293       va_list_arg_type_node = va_list_ref_type_node =
3294         build_pointer_type (TREE_TYPE (va_list_type_node));
3295     }
3296   else
3297     {
3298       va_list_arg_type_node = va_list_type_node;
3299       va_list_ref_type_node = build_reference_type (va_list_type_node);
3300     }
3301
3302 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
3303   builtin_types[ENUM] = VALUE;
3304 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
3305   def_fn_type (ENUM, RETURN, 0, 0);
3306 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
3307   def_fn_type (ENUM, RETURN, 0, 1, ARG1);
3308 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
3309   def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
3310 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
3311   def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
3312 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
3313   def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
3314 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
3315   def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
3316 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
3317                             ARG6)                                       \
3318   def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
3319 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
3320                             ARG6, ARG7)                                 \
3321   def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
3322 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
3323   def_fn_type (ENUM, RETURN, 1, 0);
3324 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
3325   def_fn_type (ENUM, RETURN, 1, 1, ARG1);
3326 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
3327   def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
3328 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
3329   def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
3330 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
3331   def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
3332 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
3333   def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
3334 #define DEF_POINTER_TYPE(ENUM, TYPE) \
3335   builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
3336
3337 #include "builtin-types.def"
3338
3339 #undef DEF_PRIMITIVE_TYPE
3340 #undef DEF_FUNCTION_TYPE_1
3341 #undef DEF_FUNCTION_TYPE_2
3342 #undef DEF_FUNCTION_TYPE_3
3343 #undef DEF_FUNCTION_TYPE_4
3344 #undef DEF_FUNCTION_TYPE_5
3345 #undef DEF_FUNCTION_TYPE_6
3346 #undef DEF_FUNCTION_TYPE_VAR_0
3347 #undef DEF_FUNCTION_TYPE_VAR_1
3348 #undef DEF_FUNCTION_TYPE_VAR_2
3349 #undef DEF_FUNCTION_TYPE_VAR_3
3350 #undef DEF_FUNCTION_TYPE_VAR_4
3351 #undef DEF_FUNCTION_TYPE_VAR_5
3352 #undef DEF_POINTER_TYPE
3353   builtin_types[(int) BT_LAST] = NULL_TREE;
3354
3355   c_init_attributes ();
3356
3357 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
3358                     NONANSI_P, ATTRS, IMPLICIT, COND)                   \
3359   if (NAME && COND)                                                     \
3360     def_builtin_1 (ENUM, NAME, CLASS,                                   \
3361                    builtin_types[(int) TYPE],                           \
3362                    builtin_types[(int) LIBTYPE],                        \
3363                    BOTH_P, FALLBACK_P, NONANSI_P,                       \
3364                    built_in_attributes[(int) ATTRS], IMPLICIT);
3365 #include "builtins.def"
3366 #undef DEF_BUILTIN
3367
3368   build_common_builtin_nodes ();
3369
3370   targetm.init_builtins ();
3371   if (flag_mudflap)
3372     mudflap_init ();
3373
3374   main_identifier_node = get_identifier ("main");
3375
3376   /* Create the built-in __null node.  It is important that this is
3377      not shared.  */
3378   null_node = make_node (INTEGER_CST);
3379   TREE_TYPE (null_node) = c_common_type_for_size (POINTER_SIZE, 0);
3380
3381   /* Since builtin_types isn't gc'ed, don't export these nodes.  */
3382   memset (builtin_types, 0, sizeof (builtin_types));
3383 }
3384
3385 /* Look up the function in built_in_decls that corresponds to DECL
3386    and set ASMSPEC as its user assembler name.  DECL must be a
3387    function decl that declares a builtin.  */
3388
3389 void
3390 set_builtin_user_assembler_name (tree decl, const char *asmspec)
3391 {
3392   tree builtin;
3393   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
3394               && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
3395               && asmspec != 0);
3396
3397   builtin = built_in_decls [DECL_FUNCTION_CODE (decl)];
3398   set_user_assembler_name (builtin, asmspec);
3399   if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMCPY)
3400     init_block_move_fn (asmspec);
3401   else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMSET)
3402     init_block_clear_fn (asmspec);
3403 }
3404
3405 /* The number of named compound-literals generated thus far.  */
3406 static GTY(()) int compound_literal_number;
3407
3408 /* Set DECL_NAME for DECL, a VAR_DECL for a compound-literal.  */
3409
3410 void
3411 set_compound_literal_name (tree decl)
3412 {
3413   char *name;
3414   ASM_FORMAT_PRIVATE_NAME (name, "__compound_literal",
3415                            compound_literal_number);
3416   compound_literal_number++;
3417   DECL_NAME (decl) = get_identifier (name);
3418 }
3419
3420 tree
3421 build_va_arg (tree expr, tree type)
3422 {
3423   return build1 (VA_ARG_EXPR, type, expr);
3424 }
3425
3426
3427 /* Linked list of disabled built-in functions.  */
3428
3429 typedef struct disabled_builtin
3430 {
3431   const char *name;
3432   struct disabled_builtin *next;
3433 } disabled_builtin;
3434 static disabled_builtin *disabled_builtins = NULL;
3435
3436 static bool builtin_function_disabled_p (const char *);
3437
3438 /* Disable a built-in function specified by -fno-builtin-NAME.  If NAME
3439    begins with "__builtin_", give an error.  */
3440
3441 void
3442 disable_builtin_function (const char *name)
3443 {
3444   if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
3445     error ("cannot disable built-in function %qs", name);
3446   else
3447     {
3448       disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin);
3449       new_disabled_builtin->name = name;
3450       new_disabled_builtin->next = disabled_builtins;
3451       disabled_builtins = new_disabled_builtin;
3452     }
3453 }
3454
3455
3456 /* Return true if the built-in function NAME has been disabled, false
3457    otherwise.  */
3458
3459 static bool
3460 builtin_function_disabled_p (const char *name)
3461 {
3462   disabled_builtin *p;
3463   for (p = disabled_builtins; p != NULL; p = p->next)
3464     {
3465       if (strcmp (name, p->name) == 0)
3466         return true;
3467     }
3468   return false;
3469 }
3470
3471
3472 /* Worker for DEF_BUILTIN.
3473    Possibly define a builtin function with one or two names.
3474    Does not declare a non-__builtin_ function if flag_no_builtin, or if
3475    nonansi_p and flag_no_nonansi_builtin.  */
3476
3477 static void
3478 def_builtin_1 (enum built_in_function fncode,
3479                const char *name,
3480                enum built_in_class fnclass,
3481                tree fntype, tree libtype,
3482                bool both_p, bool fallback_p, bool nonansi_p,
3483                tree fnattrs, bool implicit_p)
3484 {
3485   tree decl;
3486   const char *libname;
3487
3488   if (fntype == error_mark_node)
3489     return;
3490
3491   gcc_assert ((!both_p && !fallback_p)
3492               || !strncmp (name, "__builtin_",
3493                            strlen ("__builtin_")));
3494
3495   libname = name + strlen ("__builtin_");
3496   decl = lang_hooks.builtin_function (name, fntype, fncode, fnclass,
3497                                       (fallback_p ? libname : NULL),
3498                                       fnattrs);
3499   if (both_p
3500       && !flag_no_builtin && !builtin_function_disabled_p (libname)
3501       && !(nonansi_p && flag_no_nonansi_builtin))
3502     lang_hooks.builtin_function (libname, libtype, fncode, fnclass,
3503                                  NULL, fnattrs);
3504
3505   built_in_decls[(int) fncode] = decl;
3506   if (implicit_p)
3507     implicit_built_in_decls[(int) fncode] = decl;
3508 }
3509 \f
3510 /* Nonzero if the type T promotes to int.  This is (nearly) the
3511    integral promotions defined in ISO C99 6.3.1.1/2.  */
3512
3513 bool
3514 c_promoting_integer_type_p (tree t)
3515 {
3516   switch (TREE_CODE (t))
3517     {
3518     case INTEGER_TYPE:
3519       return (TYPE_MAIN_VARIANT (t) == char_type_node
3520               || TYPE_MAIN_VARIANT (t) == signed_char_type_node
3521               || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node
3522               || TYPE_MAIN_VARIANT (t) == short_integer_type_node
3523               || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node
3524               || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node));
3525
3526     case ENUMERAL_TYPE:
3527       /* ??? Technically all enumerations not larger than an int
3528          promote to an int.  But this is used along code paths
3529          that only want to notice a size change.  */
3530       return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node);
3531
3532     case BOOLEAN_TYPE:
3533       return 1;
3534
3535     default:
3536       return 0;
3537     }
3538 }
3539
3540 /* Return 1 if PARMS specifies a fixed number of parameters
3541    and none of their types is affected by default promotions.  */
3542
3543 int
3544 self_promoting_args_p (tree parms)
3545 {
3546   tree t;
3547   for (t = parms; t; t = TREE_CHAIN (t))
3548     {
3549       tree type = TREE_VALUE (t);
3550
3551       if (type == error_mark_node)
3552         continue;
3553
3554       if (TREE_CHAIN (t) == 0 && type != void_type_node)
3555         return 0;
3556
3557       if (type == 0)
3558         return 0;
3559
3560       if (TYPE_MAIN_VARIANT (type) == float_type_node)
3561         return 0;
3562
3563       if (c_promoting_integer_type_p (type))
3564         return 0;
3565     }
3566   return 1;
3567 }
3568
3569 /* Recursively examines the array elements of TYPE, until a non-array
3570    element type is found.  */
3571
3572 tree
3573 strip_array_types (tree type)
3574 {
3575   while (TREE_CODE (type) == ARRAY_TYPE)
3576     type = TREE_TYPE (type);
3577
3578   return type;
3579 }
3580
3581 /* Recursively remove any '*' or '&' operator from TYPE.  */
3582 tree
3583 strip_pointer_operator (tree t)
3584 {
3585   while (POINTER_TYPE_P (t))
3586     t = TREE_TYPE (t);
3587   return t;
3588 }
3589
3590 /* Used to compare case labels.  K1 and K2 are actually tree nodes
3591    representing case labels, or NULL_TREE for a `default' label.
3592    Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
3593    K2, and 0 if K1 and K2 are equal.  */
3594
3595 int
3596 case_compare (splay_tree_key k1, splay_tree_key k2)
3597 {
3598   /* Consider a NULL key (such as arises with a `default' label) to be
3599      smaller than anything else.  */
3600   if (!k1)
3601     return k2 ? -1 : 0;
3602   else if (!k2)
3603     return k1 ? 1 : 0;
3604
3605   return tree_int_cst_compare ((tree) k1, (tree) k2);
3606 }
3607
3608 /* Process a case label for the range LOW_VALUE ... HIGH_VALUE.  If
3609    LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is
3610    actually a `default' label.  If only HIGH_VALUE is NULL_TREE, then
3611    case label was declared using the usual C/C++ syntax, rather than
3612    the GNU case range extension.  CASES is a tree containing all the
3613    case ranges processed so far; COND is the condition for the
3614    switch-statement itself.  Returns the CASE_LABEL_EXPR created, or
3615    ERROR_MARK_NODE if no CASE_LABEL_EXPR is created.  */
3616
3617 tree
3618 c_add_case_label (splay_tree cases, tree cond, tree orig_type,
3619                   tree low_value, tree high_value)
3620 {
3621   tree type;
3622   tree label;
3623   tree case_label;
3624   splay_tree_node node;
3625
3626   /* Create the LABEL_DECL itself.  */
3627   label = create_artificial_label ();
3628
3629   /* If there was an error processing the switch condition, bail now
3630      before we get more confused.  */
3631   if (!cond || cond == error_mark_node)
3632     goto error_out;
3633
3634   if ((low_value && TREE_TYPE (low_value)
3635        && POINTER_TYPE_P (TREE_TYPE (low_value)))
3636       || (high_value && TREE_TYPE (high_value)
3637           && POINTER_TYPE_P (TREE_TYPE (high_value))))
3638     {
3639       error ("pointers are not permitted as case values");
3640       goto error_out;
3641     }
3642
3643   /* Case ranges are a GNU extension.  */
3644   if (high_value && pedantic)
3645     pedwarn ("range expressions in switch statements are non-standard");
3646
3647   type = TREE_TYPE (cond);
3648   if (low_value)
3649     {
3650       low_value = check_case_value (low_value);
3651       low_value = convert_and_check (type, low_value);
3652       if (low_value == error_mark_node)
3653         goto error_out;
3654     }
3655   if (high_value)
3656     {
3657       high_value = check_case_value (high_value);
3658       high_value = convert_and_check (type, high_value);
3659       if (high_value == error_mark_node)
3660         goto error_out;
3661     }
3662
3663   if (low_value && high_value)
3664     {
3665       /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
3666          really a case range, even though it was written that way.
3667          Remove the HIGH_VALUE to simplify later processing.  */
3668       if (tree_int_cst_equal (low_value, high_value))
3669         high_value = NULL_TREE;
3670       else if (!tree_int_cst_lt (low_value, high_value))
3671         warning (0, "empty range specified");
3672     }
3673
3674   /* See if the case is in range of the type of the original testing
3675      expression.  If both low_value and high_value are out of range,
3676      don't insert the case label and return NULL_TREE.  */
3677   if (low_value
3678       && !check_case_bounds (type, orig_type,
3679                              &low_value, high_value ? &high_value : NULL))
3680     return NULL_TREE;
3681
3682   /* Look up the LOW_VALUE in the table of case labels we already
3683      have.  */
3684   node = splay_tree_lookup (cases, (splay_tree_key) low_value);
3685   /* If there was not an exact match, check for overlapping ranges.
3686      There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
3687      that's a `default' label and the only overlap is an exact match.  */
3688   if (!node && (low_value || high_value))
3689     {
3690       splay_tree_node low_bound;
3691       splay_tree_node high_bound;
3692
3693       /* Even though there wasn't an exact match, there might be an
3694          overlap between this case range and another case range.
3695          Since we've (inductively) not allowed any overlapping case
3696          ranges, we simply need to find the greatest low case label
3697          that is smaller that LOW_VALUE, and the smallest low case
3698          label that is greater than LOW_VALUE.  If there is an overlap
3699          it will occur in one of these two ranges.  */
3700       low_bound = splay_tree_predecessor (cases,
3701                                           (splay_tree_key) low_value);
3702       high_bound = splay_tree_successor (cases,
3703                                          (splay_tree_key) low_value);
3704
3705       /* Check to see if the LOW_BOUND overlaps.  It is smaller than
3706          the LOW_VALUE, so there is no need to check unless the
3707          LOW_BOUND is in fact itself a case range.  */
3708       if (low_bound
3709           && CASE_HIGH ((tree) low_bound->value)
3710           && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
3711                                     low_value) >= 0)
3712         node = low_bound;
3713       /* Check to see if the HIGH_BOUND overlaps.  The low end of that
3714          range is bigger than the low end of the current range, so we
3715          are only interested if the current range is a real range, and
3716          not an ordinary case label.  */
3717       else if (high_bound
3718                && high_value
3719                && (tree_int_cst_compare ((tree) high_bound->key,
3720                                          high_value)
3721                    <= 0))
3722         node = high_bound;
3723     }
3724   /* If there was an overlap, issue an error.  */
3725   if (node)
3726     {
3727       tree duplicate = CASE_LABEL ((tree) node->value);
3728
3729       if (high_value)
3730         {
3731           error ("duplicate (or overlapping) case value");
3732           error ("%Jthis is the first entry overlapping that value", duplicate);
3733         }
3734       else if (low_value)
3735         {
3736           error ("duplicate case value") ;
3737           error ("%Jpreviously used here", duplicate);
3738         }
3739       else
3740         {
3741           error ("multiple default labels in one switch");
3742           error ("%Jthis is the first default label", duplicate);
3743         }
3744       goto error_out;
3745     }
3746
3747   /* Add a CASE_LABEL to the statement-tree.  */
3748   case_label = add_stmt (build_case_label (low_value, high_value, label));
3749   /* Register this case label in the splay tree.  */
3750   splay_tree_insert (cases,
3751                      (splay_tree_key) low_value,
3752                      (splay_tree_value) case_label);
3753
3754   return case_label;
3755
3756  error_out:
3757   /* Add a label so that the back-end doesn't think that the beginning of
3758      the switch is unreachable.  Note that we do not add a case label, as
3759      that just leads to duplicates and thence to failure later on.  */
3760   if (!cases->root)
3761     {
3762       tree t = create_artificial_label ();
3763       add_stmt (build_stmt (LABEL_EXPR, t));
3764     }
3765   return error_mark_node;
3766 }
3767
3768 /* Subroutines of c_do_switch_warnings, called via splay_tree_foreach.
3769    Used to verify that case values match up with enumerator values.  */
3770
3771 static void
3772 match_case_to_enum_1 (tree key, tree type, tree label)
3773 {
3774   char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1];
3775
3776   /* ??? Not working too hard to print the double-word value.
3777      Should perhaps be done with %lwd in the diagnostic routines?  */
3778   if (TREE_INT_CST_HIGH (key) == 0)
3779     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED,
3780               TREE_INT_CST_LOW (key));
3781   else if (!TYPE_UNSIGNED (type)
3782            && TREE_INT_CST_HIGH (key) == -1
3783            && TREE_INT_CST_LOW (key) != 0)
3784     snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED,
3785               -TREE_INT_CST_LOW (key));
3786   else
3787     snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX,
3788               TREE_INT_CST_HIGH (key), TREE_INT_CST_LOW (key));
3789
3790   if (TYPE_NAME (type) == 0)
3791     warning (0, "%Jcase value %qs not in enumerated type",
3792              CASE_LABEL (label), buf);
3793   else
3794     warning (0, "%Jcase value %qs not in enumerated type %qT",
3795              CASE_LABEL (label), buf, type);
3796 }
3797
3798 static int
3799 match_case_to_enum (splay_tree_node node, void *data)
3800 {
3801   tree label = (tree) node->value;
3802   tree type = (tree) data;
3803
3804   /* Skip default case.  */
3805   if (!CASE_LOW (label))
3806     return 0;
3807
3808   /* If TREE_ADDRESSABLE is not set, that means CASE_LOW did not appear
3809      when we did our enum->case scan.  Reset our scratch bit after.  */
3810   if (!TREE_ADDRESSABLE (label))
3811     match_case_to_enum_1 (CASE_LOW (label), type, label);
3812   else
3813     TREE_ADDRESSABLE (label) = 0;
3814
3815   /* If CASE_HIGH is non-null, we have a range.  Here we must search.
3816      Note that the old code in stmt.c did not check for the values in
3817      the range either, just the endpoints.  */
3818   if (CASE_HIGH (label))
3819     {
3820       tree chain, key = CASE_HIGH (label);
3821
3822       for (chain = TYPE_VALUES (type);
3823            chain && !tree_int_cst_equal (key, TREE_VALUE (chain));
3824            chain = TREE_CHAIN (chain))
3825         continue;
3826       if (!chain)
3827         match_case_to_enum_1 (key, type, label);
3828     }
3829
3830   return 0;
3831 }
3832
3833 /* Handle -Wswitch*.  Called from the front end after parsing the
3834    switch construct.  */
3835 /* ??? Should probably be somewhere generic, since other languages
3836    besides C and C++ would want this.  At the moment, however, C/C++
3837    are the only tree-ssa languages that support enumerations at all,
3838    so the point is moot.  */
3839
3840 void
3841 c_do_switch_warnings (splay_tree cases, location_t switch_location,
3842                       tree type, tree cond)
3843 {
3844   splay_tree_node default_node;
3845
3846   if (!warn_switch && !warn_switch_enum && !warn_switch_default)
3847     return;
3848
3849   default_node = splay_tree_lookup (cases, (splay_tree_key) NULL);
3850   if (!default_node)
3851     warning (OPT_Wswitch_default, "%Hswitch missing default case",
3852              &switch_location);
3853
3854   /* If the switch expression was an enumerated type, check that
3855      exactly all enumeration literals are covered by the cases.
3856      The check is made when -Wswitch was specified and there is no
3857      default case, or when -Wswitch-enum was specified.  */
3858   if (((warn_switch && !default_node) || warn_switch_enum)
3859       && type && TREE_CODE (type) == ENUMERAL_TYPE
3860       && TREE_CODE (cond) != INTEGER_CST)
3861     {
3862       tree chain;
3863
3864       /* The time complexity here is O(N*lg(N)) worst case, but for the
3865          common case of monotonically increasing enumerators, it is
3866          O(N), since the nature of the splay tree will keep the next
3867          element adjacent to the root at all times.  */
3868
3869       for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain))
3870         {
3871           splay_tree_node node
3872             = splay_tree_lookup (cases, (splay_tree_key) TREE_VALUE (chain));
3873           if (!node)
3874             {
3875               tree low_value = TREE_VALUE (chain);
3876               splay_tree_node low_bound;
3877               splay_tree_node high_bound;
3878               /* Even though there wasn't an exact match, there might be a
3879                  case range which includes the enumator's value.  */
3880               low_bound = splay_tree_predecessor (cases,
3881                                                   (splay_tree_key) low_value);
3882               high_bound = splay_tree_successor (cases,
3883                                                  (splay_tree_key) low_value);
3884
3885               /* It is smaller than the LOW_VALUE, so there is no need to check
3886                  unless the LOW_BOUND is in fact itself a case range.  */
3887               if (low_bound
3888                   && CASE_HIGH ((tree) low_bound->value)
3889                   && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
3890                                             low_value) >= 0)
3891                 node = low_bound;
3892               /* The low end of that range is bigger than the current value. */
3893               else if (high_bound
3894                        && (tree_int_cst_compare ((tree) high_bound->key,
3895                                                  low_value)
3896                            <= 0))
3897                 node = high_bound;
3898             }
3899           if (node)
3900             {
3901               /* Mark the CASE_LOW part of the case entry as seen, so
3902                  that we save time later.  Choose TREE_ADDRESSABLE
3903                  randomly as a bit that won't have been set to-date.  */
3904               tree label = (tree) node->value;
3905               TREE_ADDRESSABLE (label) = 1;
3906             }
3907           else
3908             {
3909               /* Warn if there are enumerators that don't correspond to
3910                  case expressions.  */
3911               warning (0, "%Henumeration value %qE not handled in switch",
3912                        &switch_location, TREE_PURPOSE (chain));
3913             }
3914         }
3915
3916       /* Warn if there are case expressions that don't correspond to
3917          enumerators.  This can occur since C and C++ don't enforce
3918          type-checking of assignments to enumeration variables.
3919
3920          The time complexity here is O(N**2) worst case, since we've
3921          not sorted the enumeration values.  However, in the absence
3922          of case ranges this is O(N), since all single cases that
3923          corresponded to enumerations have been marked above.  */
3924
3925       splay_tree_foreach (cases, match_case_to_enum, type);
3926     }
3927 }
3928
3929 /* Finish an expression taking the address of LABEL (an
3930    IDENTIFIER_NODE).  Returns an expression for the address.  */
3931
3932 tree
3933 finish_label_address_expr (tree label)
3934 {
3935   tree result;
3936
3937   if (pedantic)
3938     pedwarn ("taking the address of a label is non-standard");
3939
3940   if (label == error_mark_node)
3941     return error_mark_node;
3942
3943   label = lookup_label (label);
3944   if (label == NULL_TREE)
3945     result = null_pointer_node;
3946   else
3947     {
3948       TREE_USED (label) = 1;
3949       result = build1 (ADDR_EXPR, ptr_type_node, label);
3950       /* The current function in not necessarily uninlinable.
3951          Computed gotos are incompatible with inlining, but the value
3952          here could be used only in a diagnostic, for example.  */
3953     }
3954
3955   return result;
3956 }
3957
3958 /* Hook used by expand_expr to expand language-specific tree codes.  */
3959 /* The only things that should go here are bits needed to expand
3960    constant initializers.  Everything else should be handled by the
3961    gimplification routines.  */
3962
3963 rtx
3964 c_expand_expr (tree exp, rtx target, enum machine_mode tmode,
3965                int modifier /* Actually enum_modifier.  */,
3966                rtx *alt_rtl)
3967 {
3968   switch (TREE_CODE (exp))
3969     {
3970     case COMPOUND_LITERAL_EXPR:
3971       {
3972         /* Initialize the anonymous variable declared in the compound
3973            literal, then return the variable.  */
3974         tree decl = COMPOUND_LITERAL_EXPR_DECL (exp);
3975         emit_local_var (decl);
3976         return expand_expr_real (decl, target, tmode, modifier, alt_rtl);
3977       }
3978
3979     default:
3980       gcc_unreachable ();
3981     }
3982 }
3983
3984 /* Hook used by staticp to handle language-specific tree codes.  */
3985
3986 tree
3987 c_staticp (tree exp)
3988 {
3989   return (TREE_CODE (exp) == COMPOUND_LITERAL_EXPR
3990           && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp))
3991           ? exp : NULL);
3992 }
3993 \f
3994
3995 /* Given a boolean expression ARG, return a tree representing an increment
3996    or decrement (as indicated by CODE) of ARG.  The front end must check for
3997    invalid cases (e.g., decrement in C++).  */
3998 tree
3999 boolean_increment (enum tree_code code, tree arg)
4000 {
4001   tree val;
4002   tree true_res = boolean_true_node;
4003
4004   arg = stabilize_reference (arg);
4005   switch (code)
4006     {
4007     case PREINCREMENT_EXPR:
4008       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
4009       break;
4010     case POSTINCREMENT_EXPR:
4011       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res);
4012       arg = save_expr (arg);
4013       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
4014       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
4015       break;
4016     case PREDECREMENT_EXPR:
4017       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
4018                     invert_truthvalue (arg));
4019       break;
4020     case POSTDECREMENT_EXPR:
4021       val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg,
4022                     invert_truthvalue (arg));
4023       arg = save_expr (arg);
4024       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg);
4025       val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val);
4026       break;
4027     default:
4028       gcc_unreachable ();
4029     }
4030   TREE_SIDE_EFFECTS (val) = 1;
4031   return val;
4032 }
4033 \f
4034 /* Built-in macros for stddef.h, that require macros defined in this
4035    file.  */
4036 void
4037 c_stddef_cpp_builtins(void)
4038 {
4039   builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0);
4040   builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0);
4041   builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0);
4042   builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0);
4043   builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0);
4044   builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0);
4045 }
4046
4047 static void
4048 c_init_attributes (void)
4049 {
4050   /* Fill in the built_in_attributes array.  */
4051 #define DEF_ATTR_NULL_TREE(ENUM)                                \
4052   built_in_attributes[(int) ENUM] = NULL_TREE;
4053 #define DEF_ATTR_INT(ENUM, VALUE)                               \
4054   built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
4055 #define DEF_ATTR_IDENT(ENUM, STRING)                            \
4056   built_in_attributes[(int) ENUM] = get_identifier (STRING);
4057 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
4058   built_in_attributes[(int) ENUM]                       \
4059     = tree_cons (built_in_attributes[(int) PURPOSE],    \
4060                  built_in_attributes[(int) VALUE],      \
4061                  built_in_attributes[(int) CHAIN]);
4062 #include "builtin-attrs.def"
4063 #undef DEF_ATTR_NULL_TREE
4064 #undef DEF_ATTR_INT
4065 #undef DEF_ATTR_IDENT
4066 #undef DEF_ATTR_TREE_LIST
4067 }
4068
4069 /* Attribute handlers common to C front ends.  */
4070
4071 /* Handle a "packed" attribute; arguments as in
4072    struct attribute_spec.handler.  */
4073
4074 static tree
4075 handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4076                          int flags, bool *no_add_attrs)
4077 {
4078   if (TYPE_P (*node))
4079     {
4080       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4081         *node = build_variant_type_copy (*node);
4082       TYPE_PACKED (*node) = 1;
4083       if (TYPE_MAIN_VARIANT (*node) == *node)
4084         {
4085           /* If it is the main variant, then pack the other variants
4086              too. This happens in,
4087
4088              struct Foo {
4089                struct Foo const *ptr; // creates a variant w/o packed flag
4090              } __ attribute__((packed)); // packs it now.
4091            */
4092           tree probe;
4093
4094           for (probe = *node; probe; probe = TYPE_NEXT_VARIANT (probe))
4095             TYPE_PACKED (probe) = 1;
4096         }
4097     }
4098   else if (TREE_CODE (*node) == FIELD_DECL)
4099     {
4100       if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT)
4101         warning (OPT_Wattributes,
4102                  "%qE attribute ignored for field of type %qT",
4103                  name, TREE_TYPE (*node));
4104       else
4105         DECL_PACKED (*node) = 1;
4106     }
4107   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
4108      used for DECL_REGISTER.  It wouldn't mean anything anyway.
4109      We can't set DECL_PACKED on the type of a TYPE_DECL, because
4110      that changes what the typedef is typing.  */
4111   else
4112     {
4113       warning (OPT_Wattributes, "%qE attribute ignored", name);
4114       *no_add_attrs = true;
4115     }
4116
4117   return NULL_TREE;
4118 }
4119
4120 /* Handle a "nocommon" attribute; arguments as in
4121    struct attribute_spec.handler.  */
4122
4123 static tree
4124 handle_nocommon_attribute (tree *node, tree name,
4125                            tree ARG_UNUSED (args),
4126                            int ARG_UNUSED (flags), bool *no_add_attrs)
4127 {
4128   if (TREE_CODE (*node) == VAR_DECL)
4129     DECL_COMMON (*node) = 0;
4130   else
4131     {
4132       warning (OPT_Wattributes, "%qE attribute ignored", name);
4133       *no_add_attrs = true;
4134     }
4135
4136   return NULL_TREE;
4137 }
4138
4139 /* Handle a "common" attribute; arguments as in
4140    struct attribute_spec.handler.  */
4141
4142 static tree
4143 handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4144                          int ARG_UNUSED (flags), bool *no_add_attrs)
4145 {
4146   if (TREE_CODE (*node) == VAR_DECL)
4147     DECL_COMMON (*node) = 1;
4148   else
4149     {
4150       warning (OPT_Wattributes, "%qE attribute ignored", name);
4151       *no_add_attrs = true;
4152     }
4153
4154   return NULL_TREE;
4155 }
4156
4157 /* Handle a "noreturn" attribute; arguments as in
4158    struct attribute_spec.handler.  */
4159
4160 static tree
4161 handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4162                            int ARG_UNUSED (flags), bool *no_add_attrs)
4163 {
4164   tree type = TREE_TYPE (*node);
4165
4166   /* See FIXME comment in c_common_attribute_table.  */
4167   if (TREE_CODE (*node) == FUNCTION_DECL)
4168     TREE_THIS_VOLATILE (*node) = 1;
4169   else if (TREE_CODE (type) == POINTER_TYPE
4170            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4171     TREE_TYPE (*node)
4172       = build_pointer_type
4173         (build_type_variant (TREE_TYPE (type),
4174                              TYPE_READONLY (TREE_TYPE (type)), 1));
4175   else
4176     {
4177       warning (OPT_Wattributes, "%qE attribute ignored", name);
4178       *no_add_attrs = true;
4179     }
4180
4181   return NULL_TREE;
4182 }
4183
4184 /* Handle a "noinline" attribute; arguments as in
4185    struct attribute_spec.handler.  */
4186
4187 static tree
4188 handle_noinline_attribute (tree *node, tree name,
4189                            tree ARG_UNUSED (args),
4190                            int ARG_UNUSED (flags), bool *no_add_attrs)
4191 {
4192   if (TREE_CODE (*node) == FUNCTION_DECL)
4193     DECL_UNINLINABLE (*node) = 1;
4194   else
4195     {
4196       warning (OPT_Wattributes, "%qE attribute ignored", name);
4197       *no_add_attrs = true;
4198     }
4199
4200   return NULL_TREE;
4201 }
4202
4203 /* Handle a "always_inline" attribute; arguments as in
4204    struct attribute_spec.handler.  */
4205
4206 static tree
4207 handle_always_inline_attribute (tree *node, tree name,
4208                                 tree ARG_UNUSED (args),
4209                                 int ARG_UNUSED (flags),
4210                                 bool *no_add_attrs)
4211 {
4212   if (TREE_CODE (*node) == FUNCTION_DECL)
4213     {
4214       /* Do nothing else, just set the attribute.  We'll get at
4215          it later with lookup_attribute.  */
4216     }
4217   else
4218     {
4219       warning (OPT_Wattributes, "%qE attribute ignored", name);
4220       *no_add_attrs = true;
4221     }
4222
4223   return NULL_TREE;
4224 }
4225
4226 /* Handle a "flatten" attribute; arguments as in
4227    struct attribute_spec.handler.  */
4228
4229 static tree
4230 handle_flatten_attribute (tree *node, tree name,
4231                           tree args ATTRIBUTE_UNUSED,
4232                           int flags ATTRIBUTE_UNUSED, bool *no_add_attrs)
4233 {
4234   if (TREE_CODE (*node) == FUNCTION_DECL)
4235     /* Do nothing else, just set the attribute.  We'll get at
4236        it later with lookup_attribute.  */
4237     ;
4238   else
4239     {
4240       warning (OPT_Wattributes, "%qE attribute ignored", name);
4241       *no_add_attrs = true;
4242     }
4243
4244   return NULL_TREE;
4245 }
4246
4247
4248 /* Handle a "used" attribute; arguments as in
4249    struct attribute_spec.handler.  */
4250
4251 static tree
4252 handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
4253                        int ARG_UNUSED (flags), bool *no_add_attrs)
4254 {
4255   tree node = *pnode;
4256
4257   if (TREE_CODE (node) == FUNCTION_DECL
4258       || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node)))
4259     {
4260       TREE_USED (node) = 1;
4261       DECL_PRESERVE_P (node) = 1;
4262     }
4263   else
4264     {
4265       warning (OPT_Wattributes, "%qE attribute ignored", name);
4266       *no_add_attrs = true;
4267     }
4268
4269   return NULL_TREE;
4270 }
4271
4272 /* Handle a "unused" attribute; arguments as in
4273    struct attribute_spec.handler.  */
4274
4275 static tree
4276 handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4277                          int flags, bool *no_add_attrs)
4278 {
4279   if (DECL_P (*node))
4280     {
4281       tree decl = *node;
4282
4283       if (TREE_CODE (decl) == PARM_DECL
4284           || TREE_CODE (decl) == VAR_DECL
4285           || TREE_CODE (decl) == FUNCTION_DECL
4286           || TREE_CODE (decl) == LABEL_DECL
4287           || TREE_CODE (decl) == TYPE_DECL)
4288         TREE_USED (decl) = 1;
4289       else
4290         {
4291           warning (OPT_Wattributes, "%qE attribute ignored", name);
4292           *no_add_attrs = true;
4293         }
4294     }
4295   else
4296     {
4297       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4298         *node = build_variant_type_copy (*node);
4299       TREE_USED (*node) = 1;
4300     }
4301
4302   return NULL_TREE;
4303 }
4304
4305 /* Handle a "externally_visible" attribute; arguments as in
4306    struct attribute_spec.handler.  */
4307
4308 static tree
4309 handle_externally_visible_attribute (tree *pnode, tree name,
4310                                      tree ARG_UNUSED (args),
4311                                      int ARG_UNUSED (flags),
4312                                      bool *no_add_attrs)
4313 {
4314   tree node = *pnode;
4315
4316   if ((!TREE_STATIC (node) && TREE_CODE (node) != FUNCTION_DECL)
4317       || !TREE_PUBLIC (node))
4318     {
4319       warning (OPT_Wattributes,
4320                "%qE attribute have effect only on public objects", name);
4321       *no_add_attrs = true;
4322     }
4323   else if (TREE_CODE (node) == FUNCTION_DECL)
4324     {
4325       struct cgraph_node *n = cgraph_node (node);
4326       n->local.externally_visible = true;
4327       if (n->local.finalized)
4328         cgraph_mark_needed_node (n);
4329     }
4330   else if (TREE_CODE (node) == VAR_DECL)
4331     {
4332       struct cgraph_varpool_node *n = cgraph_varpool_node (node);
4333       n->externally_visible = true;
4334       if (n->finalized)
4335         cgraph_varpool_mark_needed_node (n);
4336     }
4337   else
4338     {
4339       warning (OPT_Wattributes, "%qE attribute ignored", name);
4340       *no_add_attrs = true;
4341     }
4342
4343   return NULL_TREE;
4344 }
4345
4346 /* Handle a "const" attribute; arguments as in
4347    struct attribute_spec.handler.  */
4348
4349 static tree
4350 handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4351                         int ARG_UNUSED (flags), bool *no_add_attrs)
4352 {
4353   tree type = TREE_TYPE (*node);
4354
4355   /* See FIXME comment on noreturn in c_common_attribute_table.  */
4356   if (TREE_CODE (*node) == FUNCTION_DECL)
4357     TREE_READONLY (*node) = 1;
4358   else if (TREE_CODE (type) == POINTER_TYPE
4359            && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4360     TREE_TYPE (*node)
4361       = build_pointer_type
4362         (build_type_variant (TREE_TYPE (type), 1,
4363                              TREE_THIS_VOLATILE (TREE_TYPE (type))));
4364   else
4365     {
4366       warning (OPT_Wattributes, "%qE attribute ignored", name);
4367       *no_add_attrs = true;
4368     }
4369
4370   return NULL_TREE;
4371 }
4372
4373 /* Handle a "transparent_union" attribute; arguments as in
4374    struct attribute_spec.handler.  */
4375
4376 static tree
4377 handle_transparent_union_attribute (tree *node, tree name,
4378                                     tree ARG_UNUSED (args), int flags,
4379                                     bool *no_add_attrs)
4380 {
4381   tree type = NULL;
4382
4383   *no_add_attrs = true;
4384
4385   if (DECL_P (*node))
4386     {
4387       if (TREE_CODE (*node) != TYPE_DECL)
4388         goto ignored;
4389       node = &TREE_TYPE (*node);
4390       type = *node;
4391     }
4392   else if (TYPE_P (*node))
4393     type = *node;
4394   else
4395     goto ignored;
4396
4397   if (TREE_CODE (type) == UNION_TYPE)
4398     {
4399       /* When IN_PLACE is set, leave the check for FIELDS and MODE to
4400          the code in finish_struct.  */
4401       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4402         {
4403           if (TYPE_FIELDS (type) == NULL_TREE
4404               || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type)))
4405             goto ignored;
4406
4407           /* A type variant isn't good enough, since we don't a cast
4408              to such a type removed as a no-op.  */
4409           *node = type = build_duplicate_type (type);
4410         }
4411
4412       TYPE_TRANSPARENT_UNION (type) = 1;
4413       return NULL_TREE;
4414     }
4415
4416  ignored:
4417   warning (OPT_Wattributes, "%qE attribute ignored", name);
4418   return NULL_TREE;
4419 }
4420
4421 /* Handle a "constructor" attribute; arguments as in
4422    struct attribute_spec.handler.  */
4423
4424 static tree
4425 handle_constructor_attribute (tree *node, tree name,
4426                               tree ARG_UNUSED (args),
4427                               int ARG_UNUSED (flags),
4428                               bool *no_add_attrs)
4429 {
4430   tree decl = *node;
4431   tree type = TREE_TYPE (decl);
4432
4433   if (TREE_CODE (decl) == FUNCTION_DECL
4434       && TREE_CODE (type) == FUNCTION_TYPE
4435       && decl_function_context (decl) == 0)
4436     {
4437       DECL_STATIC_CONSTRUCTOR (decl) = 1;
4438       TREE_USED (decl) = 1;
4439     }
4440   else
4441     {
4442       warning (OPT_Wattributes, "%qE attribute ignored", name);
4443       *no_add_attrs = true;
4444     }
4445
4446   return NULL_TREE;
4447 }
4448
4449 /* Handle a "destructor" attribute; arguments as in
4450    struct attribute_spec.handler.  */
4451
4452 static tree
4453 handle_destructor_attribute (tree *node, tree name,
4454                              tree ARG_UNUSED (args),
4455                              int ARG_UNUSED (flags),
4456                              bool *no_add_attrs)
4457 {
4458   tree decl = *node;
4459   tree type = TREE_TYPE (decl);
4460
4461   if (TREE_CODE (decl) == FUNCTION_DECL
4462       && TREE_CODE (type) == FUNCTION_TYPE
4463       && decl_function_context (decl) == 0)
4464     {
4465       DECL_STATIC_DESTRUCTOR (decl) = 1;
4466       TREE_USED (decl) = 1;
4467     }
4468   else
4469     {
4470       warning (OPT_Wattributes, "%qE attribute ignored", name);
4471       *no_add_attrs = true;
4472     }
4473
4474   return NULL_TREE;
4475 }
4476
4477 /* Handle a "mode" attribute; arguments as in
4478    struct attribute_spec.handler.  */
4479
4480 static tree
4481 handle_mode_attribute (tree *node, tree name, tree args,
4482                        int ARG_UNUSED (flags), bool *no_add_attrs)
4483 {
4484   tree type = *node;
4485
4486   *no_add_attrs = true;
4487
4488   if (TREE_CODE (TREE_VALUE (args)) != IDENTIFIER_NODE)
4489     warning (OPT_Wattributes, "%qE attribute ignored", name);
4490   else
4491     {
4492       int j;
4493       const char *p = IDENTIFIER_POINTER (TREE_VALUE (args));
4494       int len = strlen (p);
4495       enum machine_mode mode = VOIDmode;
4496       tree typefm;
4497       bool valid_mode;
4498
4499       if (len > 4 && p[0] == '_' && p[1] == '_'
4500           && p[len - 1] == '_' && p[len - 2] == '_')
4501         {
4502           char *newp = (char *) alloca (len - 1);
4503
4504           strcpy (newp, &p[2]);
4505           newp[len - 4] = '\0';
4506           p = newp;
4507         }
4508
4509       /* Change this type to have a type with the specified mode.
4510          First check for the special modes.  */
4511       if (!strcmp (p, "byte"))
4512         mode = byte_mode;
4513       else if (!strcmp (p, "word"))
4514         mode = word_mode;
4515       else if (!strcmp (p, "pointer"))
4516         mode = ptr_mode;
4517       else
4518         for (j = 0; j < NUM_MACHINE_MODES; j++)
4519           if (!strcmp (p, GET_MODE_NAME (j)))
4520             {
4521               mode = (enum machine_mode) j;
4522               break;
4523             }
4524
4525       if (mode == VOIDmode)
4526         {
4527           error ("unknown machine mode %qs", p);
4528           return NULL_TREE;
4529         }
4530
4531       valid_mode = false;
4532       switch (GET_MODE_CLASS (mode))
4533         {
4534         case MODE_INT:
4535         case MODE_PARTIAL_INT:
4536         case MODE_FLOAT:
4537         case MODE_DECIMAL_FLOAT:
4538           valid_mode = targetm.scalar_mode_supported_p (mode);
4539           break;
4540
4541         case MODE_COMPLEX_INT:
4542         case MODE_COMPLEX_FLOAT:
4543           valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode));
4544           break;
4545
4546         case MODE_VECTOR_INT:
4547         case MODE_VECTOR_FLOAT:
4548           warning (OPT_Wattributes, "specifying vector types with "
4549                    "__attribute__ ((mode)) is deprecated");
4550           warning (OPT_Wattributes,
4551                    "use __attribute__ ((vector_size)) instead");
4552           valid_mode = vector_mode_valid_p (mode);
4553           break;
4554
4555         default:
4556           break;
4557         }
4558       if (!valid_mode)
4559         {
4560           error ("unable to emulate %qs", p);
4561           return NULL_TREE;
4562         }
4563
4564       if (POINTER_TYPE_P (type))
4565         {
4566           tree (*fn)(tree, enum machine_mode, bool);
4567
4568           if (!targetm.valid_pointer_mode (mode))
4569             {
4570               error ("invalid pointer mode %qs", p);
4571               return NULL_TREE;
4572             }
4573
4574           if (TREE_CODE (type) == POINTER_TYPE)
4575             fn = build_pointer_type_for_mode;
4576           else
4577             fn = build_reference_type_for_mode;
4578           typefm = fn (TREE_TYPE (type), mode, false);
4579         }
4580       else
4581         typefm = lang_hooks.types.type_for_mode (mode, TYPE_UNSIGNED (type));
4582
4583       if (typefm == NULL_TREE)
4584         {
4585           error ("no data type for mode %qs", p);
4586           return NULL_TREE;
4587         }
4588       else if (TREE_CODE (type) == ENUMERAL_TYPE)
4589         {
4590           /* For enumeral types, copy the precision from the integer
4591              type returned above.  If not an INTEGER_TYPE, we can't use
4592              this mode for this type.  */
4593           if (TREE_CODE (typefm) != INTEGER_TYPE)
4594             {
4595               error ("cannot use mode %qs for enumeral types", p);
4596               return NULL_TREE;
4597             }
4598
4599           if (flags & ATTR_FLAG_TYPE_IN_PLACE)
4600             {
4601               TYPE_PRECISION (type) = TYPE_PRECISION (typefm);
4602               typefm = type;
4603             }
4604           else
4605             {
4606               /* We cannot build a type variant, as there's code that assumes
4607                  that TYPE_MAIN_VARIANT has the same mode.  This includes the
4608                  debug generators.  Instead, create a subrange type.  This
4609                  results in all of the enumeral values being emitted only once
4610                  in the original, and the subtype gets them by reference.  */
4611               if (TYPE_UNSIGNED (type))
4612                 typefm = make_unsigned_type (TYPE_PRECISION (typefm));
4613               else
4614                 typefm = make_signed_type (TYPE_PRECISION (typefm));
4615               TREE_TYPE (typefm) = type;
4616             }
4617         }
4618       else if (VECTOR_MODE_P (mode)
4619                ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm))
4620                : TREE_CODE (type) != TREE_CODE (typefm))
4621         {
4622           error ("mode %qs applied to inappropriate type", p);
4623           return NULL_TREE;
4624         }
4625
4626       *node = typefm;
4627     }
4628
4629   return NULL_TREE;
4630 }
4631
4632 /* Handle a "section" attribute; arguments as in
4633    struct attribute_spec.handler.  */
4634
4635 static tree
4636 handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args,
4637                           int ARG_UNUSED (flags), bool *no_add_attrs)
4638 {
4639   tree decl = *node;
4640
4641   if (targetm.have_named_sections)
4642     {
4643       user_defined_section_attribute = true;
4644
4645       if ((TREE_CODE (decl) == FUNCTION_DECL
4646            || TREE_CODE (decl) == VAR_DECL)
4647           && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
4648         {
4649           if (TREE_CODE (decl) == VAR_DECL
4650               && current_function_decl != NULL_TREE
4651               && !TREE_STATIC (decl))
4652             {
4653               error ("%Jsection attribute cannot be specified for "
4654                      "local variables", decl);
4655               *no_add_attrs = true;
4656             }
4657
4658           /* The decl may have already been given a section attribute
4659              from a previous declaration.  Ensure they match.  */
4660           else if (DECL_SECTION_NAME (decl) != NULL_TREE
4661                    && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
4662                               TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
4663             {
4664               error ("section of %q+D conflicts with previous declaration",
4665                      *node);
4666               *no_add_attrs = true;
4667             }
4668           else
4669             DECL_SECTION_NAME (decl) = TREE_VALUE (args);
4670         }
4671       else
4672         {
4673           error ("section attribute not allowed for %q+D", *node);
4674           *no_add_attrs = true;
4675         }
4676     }
4677   else
4678     {
4679       error ("%Jsection attributes are not supported for this target", *node);
4680       *no_add_attrs = true;
4681     }
4682
4683   return NULL_TREE;
4684 }
4685
4686 /* Handle a "aligned" attribute; arguments as in
4687    struct attribute_spec.handler.  */
4688
4689 static tree
4690 handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args,
4691                           int flags, bool *no_add_attrs)
4692 {
4693   tree decl = NULL_TREE;
4694   tree *type = NULL;
4695   int is_type = 0;
4696   tree align_expr = (args ? TREE_VALUE (args)
4697                      : size_int (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
4698   int i;
4699
4700   if (DECL_P (*node))
4701     {
4702       decl = *node;
4703       type = &TREE_TYPE (decl);
4704       is_type = TREE_CODE (*node) == TYPE_DECL;
4705     }
4706   else if (TYPE_P (*node))
4707     type = node, is_type = 1;
4708
4709   if (TREE_CODE (align_expr) != INTEGER_CST)
4710     {
4711       error ("requested alignment is not a constant");
4712       *no_add_attrs = true;
4713     }
4714   else if ((i = tree_log2 (align_expr)) == -1)
4715     {
4716       error ("requested alignment is not a power of 2");
4717       *no_add_attrs = true;
4718     }
4719   else if (i > HOST_BITS_PER_INT - 2)
4720     {
4721       error ("requested alignment is too large");
4722       *no_add_attrs = true;
4723     }
4724   else if (is_type)
4725     {
4726       /* If we have a TYPE_DECL, then copy the type, so that we
4727          don't accidentally modify a builtin type.  See pushdecl.  */
4728       if (decl && TREE_TYPE (decl) != error_mark_node
4729           && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
4730         {
4731           tree tt = TREE_TYPE (decl);
4732           *type = build_variant_type_copy (*type);
4733           DECL_ORIGINAL_TYPE (decl) = tt;
4734           TYPE_NAME (*type) = decl;
4735           TREE_USED (*type) = TREE_USED (decl);
4736           TREE_TYPE (decl) = *type;
4737         }
4738       else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
4739         *type = build_variant_type_copy (*type);
4740
4741       TYPE_ALIGN (*type) = (1 << i) * BITS_PER_UNIT;
4742       TYPE_USER_ALIGN (*type) = 1;
4743     }
4744   else if (TREE_CODE (decl) != VAR_DECL
4745            && TREE_CODE (decl) != FIELD_DECL)
4746     {
4747       error ("alignment may not be specified for %q+D", decl);
4748       *no_add_attrs = true;
4749     }
4750   else
4751     {
4752       DECL_ALIGN (decl) = (1 << i) * BITS_PER_UNIT;
4753       DECL_USER_ALIGN (decl) = 1;
4754     }
4755
4756   return NULL_TREE;
4757 }
4758
4759 /* Handle a "weak" attribute; arguments as in
4760    struct attribute_spec.handler.  */
4761
4762 static tree
4763 handle_weak_attribute (tree *node, tree ARG_UNUSED (name),
4764                        tree ARG_UNUSED (args),
4765                        int ARG_UNUSED (flags),
4766                        bool * ARG_UNUSED (no_add_attrs))
4767 {
4768   declare_weak (*node);
4769
4770   return NULL_TREE;
4771 }
4772
4773 /* Handle an "alias" attribute; arguments as in
4774    struct attribute_spec.handler.  */
4775
4776 static tree
4777 handle_alias_attribute (tree *node, tree name, tree args,
4778                         int ARG_UNUSED (flags), bool *no_add_attrs)
4779 {
4780   tree decl = *node;
4781
4782   if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
4783       || (TREE_CODE (decl) != FUNCTION_DECL
4784           && TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl))
4785       /* A static variable declaration is always a tentative definition,
4786          but the alias is a non-tentative definition which overrides.  */
4787       || (TREE_CODE (decl) != FUNCTION_DECL
4788           && ! TREE_PUBLIC (decl) && DECL_INITIAL (decl)))
4789     {
4790       error ("%q+D defined both normally and as an alias", decl);
4791       *no_add_attrs = true;
4792     }
4793
4794   /* Note that the very first time we process a nested declaration,
4795      decl_function_context will not be set.  Indeed, *would* never
4796      be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that
4797      we do below.  After such frobbery, pushdecl would set the context.
4798      In any case, this is never what we want.  */
4799   else if (decl_function_context (decl) == 0 && current_function_decl == NULL)
4800     {
4801       tree id;
4802
4803       id = TREE_VALUE (args);
4804       if (TREE_CODE (id) != STRING_CST)
4805         {
4806           error ("alias argument not a string");
4807           *no_add_attrs = true;
4808           return NULL_TREE;
4809         }
4810       id = get_identifier (TREE_STRING_POINTER (id));
4811       /* This counts as a use of the object pointed to.  */
4812       TREE_USED (id) = 1;
4813
4814       if (TREE_CODE (decl) == FUNCTION_DECL)
4815         DECL_INITIAL (decl) = error_mark_node;
4816       else
4817         {
4818           if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
4819             DECL_EXTERNAL (decl) = 1;
4820           else
4821             DECL_EXTERNAL (decl) = 0;
4822           TREE_STATIC (decl) = 1;
4823         }
4824     }
4825   else
4826     {
4827       warning (OPT_Wattributes, "%qE attribute ignored", name);
4828       *no_add_attrs = true;
4829     }
4830
4831   return NULL_TREE;
4832 }
4833
4834 /* Handle a "weakref" attribute; arguments as in struct
4835    attribute_spec.handler.  */
4836
4837 static tree
4838 handle_weakref_attribute (tree *node, tree ARG_UNUSED (name), tree args,
4839                           int flags, bool *no_add_attrs)
4840 {
4841   tree attr = NULL_TREE;
4842
4843   /* The idea here is that `weakref("name")' mutates into `weakref,
4844      alias("name")', and weakref without arguments, in turn,
4845      implicitly adds weak. */
4846
4847   if (args)
4848     {
4849       attr = tree_cons (get_identifier ("alias"), args, attr);
4850       attr = tree_cons (get_identifier ("weakref"), NULL_TREE, attr);
4851
4852       *no_add_attrs = true;
4853
4854       decl_attributes (node, attr, flags);
4855     }
4856   else
4857     {
4858       if (lookup_attribute ("alias", DECL_ATTRIBUTES (*node)))
4859         error ("%Jweakref attribute must appear before alias attribute",
4860                *node);
4861
4862       /* Can't call declare_weak because it wants this to be TREE_PUBLIC,
4863          and that isn't supported; and because it wants to add it to
4864          the list of weak decls, which isn't helpful.  */
4865       DECL_WEAK (*node) = 1;
4866     }
4867
4868   return NULL_TREE;
4869 }
4870
4871 /* Handle an "visibility" attribute; arguments as in
4872    struct attribute_spec.handler.  */
4873
4874 static tree
4875 handle_visibility_attribute (tree *node, tree name, tree args,
4876                              int ARG_UNUSED (flags),
4877                              bool *no_add_attrs)
4878 {
4879   tree decl = *node;
4880   tree id = TREE_VALUE (args);
4881
4882   *no_add_attrs = true;
4883
4884   if (TYPE_P (*node))
4885     {
4886       if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE)
4887        {
4888          warning (OPT_Wattributes, "%qE attribute ignored on non-class types",
4889                   name);
4890          return NULL_TREE;
4891        }
4892     }
4893   else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl))
4894     {
4895       warning (OPT_Wattributes, "%qE attribute ignored", name);
4896       return NULL_TREE;
4897     }
4898
4899   if (TREE_CODE (id) != STRING_CST)
4900     {
4901       error ("visibility argument not a string");
4902       return NULL_TREE;
4903     }
4904
4905   /*  If this is a type, set the visibility on the type decl.  */
4906   if (TYPE_P (decl))
4907     {
4908       decl = TYPE_NAME (decl);
4909       if (!decl)
4910         return NULL_TREE;
4911       if (TREE_CODE (decl) == IDENTIFIER_NODE)
4912         {
4913            warning (OPT_Wattributes, "%qE attribute ignored on types",
4914                     name);
4915            return NULL_TREE;
4916         }
4917     }
4918
4919   if (strcmp (TREE_STRING_POINTER (id), "default") == 0)
4920     DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
4921   else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0)
4922     DECL_VISIBILITY (decl) = VISIBILITY_INTERNAL;
4923   else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0)
4924     DECL_VISIBILITY (decl) = VISIBILITY_HIDDEN;
4925   else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0)
4926     DECL_VISIBILITY (decl) = VISIBILITY_PROTECTED;
4927   else
4928     error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\"");
4929   DECL_VISIBILITY_SPECIFIED (decl) = 1;
4930
4931   /* For decls only, go ahead and attach the attribute to the node as well.
4932      This is needed so we can determine whether we have VISIBILITY_DEFAULT
4933      because the visibility was not specified, or because it was explicitly
4934      overridden from the class visibility.  */
4935   if (DECL_P (*node))
4936     *no_add_attrs = false;
4937
4938   return NULL_TREE;
4939 }
4940
4941 /* Determine the ELF symbol visibility for DECL, which is either a
4942    variable or a function.  It is an error to use this function if a
4943    definition of DECL is not available in this translation unit.
4944    Returns true if the final visibility has been determined by this
4945    function; false if the caller is free to make additional
4946    modifications.  */
4947
4948 bool
4949 c_determine_visibility (tree decl)
4950 {
4951   gcc_assert (TREE_CODE (decl) == VAR_DECL
4952               || TREE_CODE (decl) == FUNCTION_DECL);
4953
4954   /* If the user explicitly specified the visibility with an
4955      attribute, honor that.  DECL_VISIBILITY will have been set during
4956      the processing of the attribute.  We check for an explicit
4957      attribute, rather than just checking DECL_VISIBILITY_SPECIFIED,
4958      to distinguish the use of an attribute from the use of a "#pragma
4959      GCC visibility push(...)"; in the latter case we still want other
4960      considerations to be able to overrule the #pragma.  */
4961   if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl)))
4962     return true;
4963
4964   /* Anything that is exported must have default visibility.  */
4965   if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
4966       && lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))
4967     {
4968       DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
4969       DECL_VISIBILITY_SPECIFIED (decl) = 1;
4970       return true;
4971     }
4972
4973   return false;
4974 }
4975
4976 /* Handle an "tls_model" attribute; arguments as in
4977    struct attribute_spec.handler.  */
4978
4979 static tree
4980 handle_tls_model_attribute (tree *node, tree name, tree args,
4981                             int ARG_UNUSED (flags), bool *no_add_attrs)
4982 {
4983   tree id;
4984   tree decl = *node;
4985   enum tls_model kind;
4986
4987   *no_add_attrs = true;
4988
4989   if (!DECL_THREAD_LOCAL_P (decl))
4990     {
4991       warning (OPT_Wattributes, "%qE attribute ignored", name);
4992       return NULL_TREE;
4993     }
4994
4995   kind = DECL_TLS_MODEL (decl);
4996   id = TREE_VALUE (args);
4997   if (TREE_CODE (id) != STRING_CST)
4998     {
4999       error ("tls_model argument not a string");
5000       return NULL_TREE;
5001     }
5002
5003   if (!strcmp (TREE_STRING_POINTER (id), "local-exec"))
5004     kind = TLS_MODEL_LOCAL_EXEC;
5005   else if (!strcmp (TREE_STRING_POINTER (id), "initial-exec"))
5006     kind = TLS_MODEL_INITIAL_EXEC;
5007   else if (!strcmp (TREE_STRING_POINTER (id), "local-dynamic"))
5008     kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
5009   else if (!strcmp (TREE_STRING_POINTER (id), "global-dynamic"))
5010     kind = TLS_MODEL_GLOBAL_DYNAMIC;
5011   else
5012     error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\"");
5013
5014   DECL_TLS_MODEL (decl) = kind;
5015   return NULL_TREE;
5016 }
5017
5018 /* Handle a "no_instrument_function" attribute; arguments as in
5019    struct attribute_spec.handler.  */
5020
5021 static tree
5022 handle_no_instrument_function_attribute (tree *node, tree name,
5023                                          tree ARG_UNUSED (args),
5024                                          int ARG_UNUSED (flags),
5025                                          bool *no_add_attrs)
5026 {
5027   tree decl = *node;
5028
5029   if (TREE_CODE (decl) != FUNCTION_DECL)
5030     {
5031       error ("%J%qE attribute applies only to functions", decl, name);
5032       *no_add_attrs = true;
5033     }
5034   else if (DECL_INITIAL (decl))
5035     {
5036       error ("%Jcan%'t set %qE attribute after definition", decl, name);
5037       *no_add_attrs = true;
5038     }
5039   else
5040     DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
5041
5042   return NULL_TREE;
5043 }
5044
5045 /* Handle a "malloc" attribute; arguments as in
5046    struct attribute_spec.handler.  */
5047
5048 static tree
5049 handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5050                          int ARG_UNUSED (flags), bool *no_add_attrs)
5051 {
5052   if (TREE_CODE (*node) == FUNCTION_DECL
5053       && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node))))
5054     DECL_IS_MALLOC (*node) = 1;
5055   else
5056     {
5057       warning (OPT_Wattributes, "%qE attribute ignored", name);
5058       *no_add_attrs = true;
5059     }
5060
5061   return NULL_TREE;
5062 }
5063
5064 /* Handle a "returns_twice" attribute; arguments as in
5065    struct attribute_spec.handler.  */
5066
5067 static tree
5068 handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5069                          int ARG_UNUSED (flags), bool *no_add_attrs)
5070 {
5071   if (TREE_CODE (*node) == FUNCTION_DECL)
5072     DECL_IS_RETURNS_TWICE (*node) = 1;
5073   else
5074     {
5075       warning (OPT_Wattributes, "%qE attribute ignored", name);
5076       *no_add_attrs = true;
5077     }
5078
5079   return NULL_TREE;
5080 }
5081
5082 /* Handle a "no_limit_stack" attribute; arguments as in
5083    struct attribute_spec.handler.  */
5084
5085 static tree
5086 handle_no_limit_stack_attribute (tree *node, tree name,
5087                                  tree ARG_UNUSED (args),
5088                                  int ARG_UNUSED (flags),
5089                                  bool *no_add_attrs)
5090 {
5091   tree decl = *node;
5092
5093   if (TREE_CODE (decl) != FUNCTION_DECL)
5094     {
5095       error ("%J%qE attribute applies only to functions", decl, name);
5096       *no_add_attrs = true;
5097     }
5098   else if (DECL_INITIAL (decl))
5099     {
5100       error ("%Jcan%'t set %qE attribute after definition", decl, name);
5101       *no_add_attrs = true;
5102     }
5103   else
5104     DECL_NO_LIMIT_STACK (decl) = 1;
5105
5106   return NULL_TREE;
5107 }
5108
5109 /* Handle a "pure" attribute; arguments as in
5110    struct attribute_spec.handler.  */
5111
5112 static tree
5113 handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5114                        int ARG_UNUSED (flags), bool *no_add_attrs)
5115 {
5116   if (TREE_CODE (*node) == FUNCTION_DECL)
5117     DECL_IS_PURE (*node) = 1;
5118   /* ??? TODO: Support types.  */
5119   else
5120     {
5121       warning (OPT_Wattributes, "%qE attribute ignored", name);
5122       *no_add_attrs = true;
5123     }
5124
5125   return NULL_TREE;
5126 }
5127
5128 /* Handle a "no vops" attribute; arguments as in
5129    struct attribute_spec.handler.  */
5130
5131 static tree
5132 handle_novops_attribute (tree *node, tree ARG_UNUSED (name),
5133                          tree ARG_UNUSED (args), int ARG_UNUSED (flags),
5134                          bool *ARG_UNUSED (no_add_attrs))
5135 {
5136   gcc_assert (TREE_CODE (*node) == FUNCTION_DECL);
5137   DECL_IS_NOVOPS (*node) = 1;
5138   return NULL_TREE;
5139 }
5140
5141 /* Handle a "deprecated" attribute; arguments as in
5142    struct attribute_spec.handler.  */
5143
5144 static tree
5145 handle_deprecated_attribute (tree *node, tree name,
5146                              tree ARG_UNUSED (args), int flags,
5147                              bool *no_add_attrs)
5148 {
5149   tree type = NULL_TREE;
5150   int warn = 0;
5151   tree what = NULL_TREE;
5152
5153   if (DECL_P (*node))
5154     {
5155       tree decl = *node;
5156       type = TREE_TYPE (decl);
5157
5158       if (TREE_CODE (decl) == TYPE_DECL
5159           || TREE_CODE (decl) == PARM_DECL
5160           || TREE_CODE (decl) == VAR_DECL
5161           || TREE_CODE (decl) == FUNCTION_DECL
5162           || TREE_CODE (decl) == FIELD_DECL)
5163         TREE_DEPRECATED (decl) = 1;
5164       else
5165         warn = 1;
5166     }
5167   else if (TYPE_P (*node))
5168     {
5169       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
5170         *node = build_variant_type_copy (*node);
5171       TREE_DEPRECATED (*node) = 1;
5172       type = *node;
5173     }
5174   else
5175     warn = 1;
5176
5177   if (warn)
5178     {
5179       *no_add_attrs = true;
5180       if (type && TYPE_NAME (type))
5181         {
5182           if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
5183             what = TYPE_NAME (*node);
5184           else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
5185                    && DECL_NAME (TYPE_NAME (type)))
5186             what = DECL_NAME (TYPE_NAME (type));
5187         }
5188       if (what)
5189         warning (OPT_Wattributes, "%qE attribute ignored for %qE", name, what);
5190       else
5191         warning (OPT_Wattributes, "%qE attribute ignored", name);
5192     }
5193
5194   return NULL_TREE;
5195 }
5196
5197 /* Handle a "vector_size" attribute; arguments as in
5198    struct attribute_spec.handler.  */
5199
5200 static tree
5201 handle_vector_size_attribute (tree *node, tree name, tree args,
5202                               int ARG_UNUSED (flags),
5203                               bool *no_add_attrs)
5204 {
5205   unsigned HOST_WIDE_INT vecsize, nunits;
5206   enum machine_mode orig_mode;
5207   tree type = *node, new_type, size;
5208
5209   *no_add_attrs = true;
5210
5211   size = TREE_VALUE (args);
5212
5213   if (!host_integerp (size, 1))
5214     {
5215       warning (OPT_Wattributes, "%qE attribute ignored", name);
5216       return NULL_TREE;
5217     }
5218
5219   /* Get the vector size (in bytes).  */
5220   vecsize = tree_low_cst (size, 1);
5221
5222   /* We need to provide for vector pointers, vector arrays, and
5223      functions returning vectors.  For example:
5224
5225        __attribute__((vector_size(16))) short *foo;
5226
5227      In this case, the mode is SI, but the type being modified is
5228      HI, so we need to look further.  */
5229
5230   while (POINTER_TYPE_P (type)
5231          || TREE_CODE (type) == FUNCTION_TYPE
5232          || TREE_CODE (type) == METHOD_TYPE
5233          || TREE_CODE (type) == ARRAY_TYPE)
5234     type = TREE_TYPE (type);
5235
5236   /* Get the mode of the type being modified.  */
5237   orig_mode = TYPE_MODE (type);
5238
5239   if (TREE_CODE (type) == RECORD_TYPE
5240       || (!SCALAR_FLOAT_MODE_P (orig_mode)
5241           && GET_MODE_CLASS (orig_mode) != MODE_INT)
5242       || !host_integerp (TYPE_SIZE_UNIT (type), 1))
5243     {
5244       error ("invalid vector type for attribute %qE", name);
5245       return NULL_TREE;
5246     }
5247
5248   if (vecsize % tree_low_cst (TYPE_SIZE_UNIT (type), 1))
5249     {
5250       error ("vector size not an integral multiple of component size");
5251       return NULL;
5252     }
5253
5254   if (vecsize == 0)
5255     {
5256       error ("zero vector size");
5257       return NULL;
5258     }
5259
5260   /* Calculate how many units fit in the vector.  */
5261   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
5262   if (nunits & (nunits - 1))
5263     {
5264       error ("number of components of the vector not a power of two");
5265       return NULL_TREE;
5266     }
5267
5268   new_type = build_vector_type (type, nunits);
5269
5270   /* Build back pointers if needed.  */
5271   *node = reconstruct_complex_type (*node, new_type);
5272
5273   return NULL_TREE;
5274 }
5275
5276 /* Handle the "nonnull" attribute.  */
5277 static tree
5278 handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
5279                           tree args, int ARG_UNUSED (flags),
5280                           bool *no_add_attrs)
5281 {
5282   tree type = *node;
5283   unsigned HOST_WIDE_INT attr_arg_num;
5284
5285   /* If no arguments are specified, all pointer arguments should be
5286      non-null.  Verify a full prototype is given so that the arguments
5287      will have the correct types when we actually check them later.  */
5288   if (!args)
5289     {
5290       if (!TYPE_ARG_TYPES (type))
5291         {
5292           error ("nonnull attribute without arguments on a non-prototype");
5293           *no_add_attrs = true;
5294         }
5295       return NULL_TREE;
5296     }
5297
5298   /* Argument list specified.  Verify that each argument number references
5299      a pointer argument.  */
5300   for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
5301     {
5302       tree argument;
5303       unsigned HOST_WIDE_INT arg_num = 0, ck_num;
5304
5305       if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
5306         {
5307           error ("nonnull argument has invalid operand number (argument %lu)",
5308                  (unsigned long) attr_arg_num);
5309           *no_add_attrs = true;
5310           return NULL_TREE;
5311         }
5312
5313       argument = TYPE_ARG_TYPES (type);
5314       if (argument)
5315         {
5316           for (ck_num = 1; ; ck_num++)
5317             {
5318               if (!argument || ck_num == arg_num)
5319                 break;
5320               argument = TREE_CHAIN (argument);
5321             }
5322
5323           if (!argument
5324               || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
5325             {
5326               error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)",
5327                      (unsigned long) attr_arg_num, (unsigned long) arg_num);
5328               *no_add_attrs = true;
5329               return NULL_TREE;
5330             }
5331
5332           if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
5333             {
5334               error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)",
5335                    (unsigned long) attr_arg_num, (unsigned long) arg_num);
5336               *no_add_attrs = true;
5337               return NULL_TREE;
5338             }
5339         }
5340     }
5341
5342   return NULL_TREE;
5343 }
5344
5345 /* Check the argument list of a function call for null in argument slots
5346    that are marked as requiring a non-null pointer argument.  */
5347
5348 static void
5349 check_function_nonnull (tree attrs, tree params)
5350 {
5351   tree a, args, param;
5352   int param_num;
5353
5354   for (a = attrs; a; a = TREE_CHAIN (a))
5355     {
5356       if (is_attribute_p ("nonnull", TREE_PURPOSE (a)))
5357         {
5358           args = TREE_VALUE (a);
5359
5360           /* Walk the argument list.  If we encounter an argument number we
5361              should check for non-null, do it.  If the attribute has no args,
5362              then every pointer argument is checked (in which case the check
5363              for pointer type is done in check_nonnull_arg).  */
5364           for (param = params, param_num = 1; ;
5365                param_num++, param = TREE_CHAIN (param))
5366             {
5367               if (!param)
5368         break;
5369               if (!args || nonnull_check_p (args, param_num))
5370         check_function_arguments_recurse (check_nonnull_arg, NULL,
5371                                           TREE_VALUE (param),
5372                                           param_num);
5373             }
5374         }
5375     }
5376 }
5377
5378 /* Check that the Nth argument of a function call (counting backwards
5379    from the end) is a (pointer)0.  */
5380
5381 static void
5382 check_function_sentinel (tree attrs, tree params, tree typelist)
5383 {
5384   tree attr = lookup_attribute ("sentinel", attrs);
5385
5386   if (attr)
5387     {
5388       /* Skip over the named arguments.  */
5389       while (typelist && params)
5390       {
5391         typelist = TREE_CHAIN (typelist);
5392         params = TREE_CHAIN (params);
5393       }
5394
5395       if (typelist || !params)
5396         warning (OPT_Wformat,
5397                  "not enough variable arguments to fit a sentinel");
5398       else
5399         {
5400           tree sentinel, end;
5401           unsigned pos = 0;
5402
5403           if (TREE_VALUE (attr))
5404             {
5405               tree p = TREE_VALUE (TREE_VALUE (attr));
5406               pos = TREE_INT_CST_LOW (p);
5407             }
5408
5409           sentinel = end = params;
5410
5411           /* Advance `end' ahead of `sentinel' by `pos' positions.  */
5412           while (pos > 0 && TREE_CHAIN (end))
5413             {
5414               pos--;
5415               end = TREE_CHAIN (end);
5416             }
5417           if (pos > 0)
5418             {
5419               warning (OPT_Wformat,
5420                        "not enough variable arguments to fit a sentinel");
5421               return;
5422             }
5423
5424           /* Now advance both until we find the last parameter.  */
5425           while (TREE_CHAIN (end))
5426             {
5427               end = TREE_CHAIN (end);
5428               sentinel = TREE_CHAIN (sentinel);
5429             }
5430
5431           /* Validate the sentinel.  */
5432           if ((!POINTER_TYPE_P (TREE_TYPE (TREE_VALUE (sentinel)))
5433                || !integer_zerop (TREE_VALUE (sentinel)))
5434               /* Although __null (in C++) is only an integer we allow it
5435                  nevertheless, as we are guaranteed that it's exactly
5436                  as wide as a pointer, and we don't want to force
5437                  users to cast the NULL they have written there.
5438                  We warn with -Wstrict-null-sentinel, though.  */
5439               && (warn_strict_null_sentinel
5440                   || null_node != TREE_VALUE (sentinel)))
5441             warning (OPT_Wformat, "missing sentinel in function call");
5442         }
5443     }
5444 }
5445
5446 /* Helper for check_function_nonnull; given a list of operands which
5447    must be non-null in ARGS, determine if operand PARAM_NUM should be
5448    checked.  */
5449
5450 static bool
5451 nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num)
5452 {
5453   unsigned HOST_WIDE_INT arg_num = 0;
5454
5455   for (; args; args = TREE_CHAIN (args))
5456     {
5457       bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num);
5458
5459       gcc_assert (found);
5460
5461       if (arg_num == param_num)
5462         return true;
5463     }
5464   return false;
5465 }
5466
5467 /* Check that the function argument PARAM (which is operand number
5468    PARAM_NUM) is non-null.  This is called by check_function_nonnull
5469    via check_function_arguments_recurse.  */
5470
5471 static void
5472 check_nonnull_arg (void * ARG_UNUSED (ctx), tree param,
5473                    unsigned HOST_WIDE_INT param_num)
5474 {
5475   /* Just skip checking the argument if it's not a pointer.  This can
5476      happen if the "nonnull" attribute was given without an operand
5477      list (which means to check every pointer argument).  */
5478
5479   if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE)
5480     return;
5481
5482   if (integer_zerop (param))
5483     warning (OPT_Wnonnull, "null argument where non-null required "
5484              "(argument %lu)", (unsigned long) param_num);
5485 }
5486
5487 /* Helper for nonnull attribute handling; fetch the operand number
5488    from the attribute argument list.  */
5489
5490 static bool
5491 get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp)
5492 {
5493   /* Verify the arg number is a constant.  */
5494   if (TREE_CODE (arg_num_expr) != INTEGER_CST
5495       || TREE_INT_CST_HIGH (arg_num_expr) != 0)
5496     return false;
5497
5498   *valp = TREE_INT_CST_LOW (arg_num_expr);
5499   return true;
5500 }
5501
5502 /* Handle a "nothrow" attribute; arguments as in
5503    struct attribute_spec.handler.  */
5504
5505 static tree
5506 handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5507                           int ARG_UNUSED (flags), bool *no_add_attrs)
5508 {
5509   if (TREE_CODE (*node) == FUNCTION_DECL)
5510     TREE_NOTHROW (*node) = 1;
5511   /* ??? TODO: Support types.  */
5512   else
5513     {
5514       warning (OPT_Wattributes, "%qE attribute ignored", name);
5515       *no_add_attrs = true;
5516     }
5517
5518   return NULL_TREE;
5519 }
5520
5521 /* Handle a "cleanup" attribute; arguments as in
5522    struct attribute_spec.handler.  */
5523
5524 static tree
5525 handle_cleanup_attribute (tree *node, tree name, tree args,
5526                           int ARG_UNUSED (flags), bool *no_add_attrs)
5527 {
5528   tree decl = *node;
5529   tree cleanup_id, cleanup_decl;
5530
5531   /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do
5532      for global destructors in C++.  This requires infrastructure that
5533      we don't have generically at the moment.  It's also not a feature
5534      we'd be missing too much, since we do have attribute constructor.  */
5535   if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl))
5536     {
5537       warning (OPT_Wattributes, "%qE attribute ignored", name);
5538       *no_add_attrs = true;
5539       return NULL_TREE;
5540     }
5541
5542   /* Verify that the argument is a function in scope.  */
5543   /* ??? We could support pointers to functions here as well, if
5544      that was considered desirable.  */
5545   cleanup_id = TREE_VALUE (args);
5546   if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE)
5547     {
5548       error ("cleanup argument not an identifier");
5549       *no_add_attrs = true;
5550       return NULL_TREE;
5551     }
5552   cleanup_decl = lookup_name (cleanup_id);
5553   if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL)
5554     {
5555       error ("cleanup argument not a function");
5556       *no_add_attrs = true;
5557       return NULL_TREE;
5558     }
5559
5560   /* That the function has proper type is checked with the
5561      eventual call to build_function_call.  */
5562
5563   return NULL_TREE;
5564 }
5565
5566 /* Handle a "warn_unused_result" attribute.  No special handling.  */
5567
5568 static tree
5569 handle_warn_unused_result_attribute (tree *node, tree name,
5570                                tree ARG_UNUSED (args),
5571                                int ARG_UNUSED (flags), bool *no_add_attrs)
5572 {
5573   /* Ignore the attribute for functions not returning any value.  */
5574   if (VOID_TYPE_P (TREE_TYPE (*node)))
5575     {
5576       warning (OPT_Wattributes, "%qE attribute ignored", name);
5577       *no_add_attrs = true;
5578     }
5579
5580   return NULL_TREE;
5581 }
5582
5583 /* Handle a "sentinel" attribute.  */
5584
5585 static tree
5586 handle_sentinel_attribute (tree *node, tree name, tree args,
5587                            int ARG_UNUSED (flags), bool *no_add_attrs)
5588 {
5589   tree params = TYPE_ARG_TYPES (*node);
5590
5591   if (!params)
5592     {
5593       warning (OPT_Wattributes,
5594                "%qE attribute requires prototypes with named arguments", name);
5595       *no_add_attrs = true;
5596     }
5597   else
5598     {
5599       while (TREE_CHAIN (params))
5600         params = TREE_CHAIN (params);
5601
5602       if (VOID_TYPE_P (TREE_VALUE (params)))
5603         {
5604           warning (OPT_Wattributes,
5605                    "%qE attribute only applies to variadic functions", name);
5606           *no_add_attrs = true;
5607         }
5608     }
5609
5610   if (args)
5611     {
5612       tree position = TREE_VALUE (args);
5613
5614       if (TREE_CODE (position) != INTEGER_CST)
5615         {
5616           warning (0, "requested position is not an integer constant");
5617           *no_add_attrs = true;
5618         }
5619       else
5620         {
5621           if (tree_int_cst_lt (position, integer_zero_node))
5622             {
5623               warning (0, "requested position is less than zero");
5624               *no_add_attrs = true;
5625             }
5626         }
5627     }
5628
5629   return NULL_TREE;
5630 }
5631 \f
5632 /* Check for valid arguments being passed to a function.  */
5633 void
5634 check_function_arguments (tree attrs, tree params, tree typelist)
5635 {
5636   /* Check for null being passed in a pointer argument that must be
5637      non-null.  We also need to do this if format checking is enabled.  */
5638
5639   if (warn_nonnull)
5640     check_function_nonnull (attrs, params);
5641
5642   /* Check for errors in format strings.  */
5643
5644   if (warn_format || warn_missing_format_attribute)
5645       check_function_format (attrs, params);
5646
5647   if (warn_format)
5648     check_function_sentinel (attrs, params, typelist);
5649 }
5650
5651 /* Generic argument checking recursion routine.  PARAM is the argument to
5652    be checked.  PARAM_NUM is the number of the argument.  CALLBACK is invoked
5653    once the argument is resolved.  CTX is context for the callback.  */
5654 void
5655 check_function_arguments_recurse (void (*callback)
5656                                   (void *, tree, unsigned HOST_WIDE_INT),
5657                                   void *ctx, tree param,
5658                                   unsigned HOST_WIDE_INT param_num)
5659 {
5660   if ((TREE_CODE (param) == NOP_EXPR || TREE_CODE (param) == CONVERT_EXPR)
5661       && (TYPE_PRECISION (TREE_TYPE (param))
5662           == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (param, 0)))))
5663     {
5664       /* Strip coercion.  */
5665       check_function_arguments_recurse (callback, ctx,
5666                                         TREE_OPERAND (param, 0), param_num);
5667       return;
5668     }
5669
5670   if (TREE_CODE (param) == CALL_EXPR)
5671     {
5672       tree type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (param, 0)));
5673       tree attrs;
5674       bool found_format_arg = false;
5675
5676       /* See if this is a call to a known internationalization function
5677          that modifies a format arg.  Such a function may have multiple
5678          format_arg attributes (for example, ngettext).  */
5679
5680       for (attrs = TYPE_ATTRIBUTES (type);
5681            attrs;
5682            attrs = TREE_CHAIN (attrs))
5683         if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs)))
5684           {
5685             tree inner_args;
5686             tree format_num_expr;
5687             int format_num;
5688             int i;
5689
5690             /* Extract the argument number, which was previously checked
5691                to be valid.  */
5692             format_num_expr = TREE_VALUE (TREE_VALUE (attrs));
5693
5694             gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST
5695                         && !TREE_INT_CST_HIGH (format_num_expr));
5696
5697             format_num = TREE_INT_CST_LOW (format_num_expr);
5698
5699             for (inner_args = TREE_OPERAND (param, 1), i = 1;
5700                  inner_args != 0;
5701                  inner_args = TREE_CHAIN (inner_args), i++)
5702               if (i == format_num)
5703                 {
5704                   check_function_arguments_recurse (callback, ctx,
5705                                                     TREE_VALUE (inner_args),
5706                                                     param_num);
5707                   found_format_arg = true;
5708                   break;
5709                 }
5710           }
5711
5712       /* If we found a format_arg attribute and did a recursive check,
5713          we are done with checking this argument.  Otherwise, we continue
5714          and this will be considered a non-literal.  */
5715       if (found_format_arg)
5716         return;
5717     }
5718
5719   if (TREE_CODE (param) == COND_EXPR)
5720     {
5721       /* Check both halves of the conditional expression.  */
5722       check_function_arguments_recurse (callback, ctx,
5723                                         TREE_OPERAND (param, 1), param_num);
5724       check_function_arguments_recurse (callback, ctx,
5725                                         TREE_OPERAND (param, 2), param_num);
5726       return;
5727     }
5728
5729   (*callback) (ctx, param, param_num);
5730 }
5731
5732 /* Function to help qsort sort FIELD_DECLs by name order.  */
5733
5734 int
5735 field_decl_cmp (const void *x_p, const void *y_p)
5736 {
5737   const tree *const x = (const tree *const) x_p;
5738   const tree *const y = (const tree *const) y_p;
5739
5740   if (DECL_NAME (*x) == DECL_NAME (*y))
5741     /* A nontype is "greater" than a type.  */
5742     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
5743   if (DECL_NAME (*x) == NULL_TREE)
5744     return -1;
5745   if (DECL_NAME (*y) == NULL_TREE)
5746     return 1;
5747   if (DECL_NAME (*x) < DECL_NAME (*y))
5748     return -1;
5749   return 1;
5750 }
5751
5752 static struct {
5753   gt_pointer_operator new_value;
5754   void *cookie;
5755 } resort_data;
5756
5757 /* This routine compares two fields like field_decl_cmp but using the
5758 pointer operator in resort_data.  */
5759
5760 static int
5761 resort_field_decl_cmp (const void *x_p, const void *y_p)
5762 {
5763   const tree *const x = (const tree *const) x_p;
5764   const tree *const y = (const tree *const) y_p;
5765
5766   if (DECL_NAME (*x) == DECL_NAME (*y))
5767     /* A nontype is "greater" than a type.  */
5768     return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL);
5769   if (DECL_NAME (*x) == NULL_TREE)
5770     return -1;
5771   if (DECL_NAME (*y) == NULL_TREE)
5772     return 1;
5773   {
5774     tree d1 = DECL_NAME (*x);
5775     tree d2 = DECL_NAME (*y);
5776     resort_data.new_value (&d1, resort_data.cookie);
5777     resort_data.new_value (&d2, resort_data.cookie);
5778     if (d1 < d2)
5779       return -1;
5780   }
5781   return 1;
5782 }
5783
5784 /* Resort DECL_SORTED_FIELDS because pointers have been reordered.  */
5785
5786 void
5787 resort_sorted_fields (void *obj,
5788                       void * ARG_UNUSED (orig_obj),
5789                       gt_pointer_operator new_value,
5790                       void *cookie)
5791 {
5792   struct sorted_fields_type *sf = (struct sorted_fields_type *) obj;
5793   resort_data.new_value = new_value;
5794   resort_data.cookie = cookie;
5795   qsort (&sf->elts[0], sf->len, sizeof (tree),
5796          resort_field_decl_cmp);
5797 }
5798
5799 /* Subroutine of c_parse_error.
5800    Return the result of concatenating LHS and RHS. RHS is really
5801    a string literal, its first character is indicated by RHS_START and
5802    RHS_SIZE is its length (including the terminating NUL character).
5803
5804    The caller is responsible for deleting the returned pointer.  */
5805
5806 static char *
5807 catenate_strings (const char *lhs, const char *rhs_start, int rhs_size)
5808 {
5809   const int lhs_size = strlen (lhs);
5810   char *result = XNEWVEC (char, lhs_size + rhs_size);
5811   strncpy (result, lhs, lhs_size);
5812   strncpy (result + lhs_size, rhs_start, rhs_size);
5813   return result;
5814 }
5815
5816 /* Issue the error given by GMSGID, indicating that it occurred before
5817    TOKEN, which had the associated VALUE.  */
5818
5819 void
5820 c_parse_error (const char *gmsgid, enum cpp_ttype token, tree value)
5821 {
5822 #define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2))
5823
5824   char *message = NULL;
5825
5826   if (token == CPP_EOF)
5827     message = catenate_messages (gmsgid, " at end of input");
5828   else if (token == CPP_CHAR || token == CPP_WCHAR)
5829     {
5830       unsigned int val = TREE_INT_CST_LOW (value);
5831       const char *const ell = (token == CPP_CHAR) ? "" : "L";
5832       if (val <= UCHAR_MAX && ISGRAPH (val))
5833         message = catenate_messages (gmsgid, " before %s'%c'");
5834       else
5835         message = catenate_messages (gmsgid, " before %s'\\x%x'");
5836
5837       error (message, ell, val);
5838       free (message);
5839       message = NULL;
5840     }
5841   else if (token == CPP_STRING || token == CPP_WSTRING)
5842     message = catenate_messages (gmsgid, " before string constant");
5843   else if (token == CPP_NUMBER)
5844     message = catenate_messages (gmsgid, " before numeric constant");
5845   else if (token == CPP_NAME)
5846     {
5847       message = catenate_messages (gmsgid, " before %qE");
5848       error (message, value);
5849       free (message);
5850       message = NULL;
5851     }
5852   else if (token == CPP_PRAGMA)
5853     message = catenate_messages (gmsgid, " before %<#pragma%>");
5854   else if (token == CPP_PRAGMA_EOL)
5855     message = catenate_messages (gmsgid, " before end of line");
5856   else if (token < N_TTYPES)
5857     {
5858       message = catenate_messages (gmsgid, " before %qs token");
5859       error (message, cpp_type2name (token));
5860       free (message);
5861       message = NULL;
5862     }
5863   else
5864     error (gmsgid);
5865
5866   if (message)
5867     {
5868       error (message);
5869       free (message);
5870     }
5871 #undef catenate_messages
5872 }
5873
5874 /* Walk a gimplified function and warn for functions whose return value is
5875    ignored and attribute((warn_unused_result)) is set.  This is done before
5876    inlining, so we don't have to worry about that.  */
5877
5878 void
5879 c_warn_unused_result (tree *top_p)
5880 {
5881   tree t = *top_p;
5882   tree_stmt_iterator i;
5883   tree fdecl, ftype;
5884
5885   switch (TREE_CODE (t))
5886     {
5887     case STATEMENT_LIST:
5888       for (i = tsi_start (*top_p); !tsi_end_p (i); tsi_next (&i))
5889         c_warn_unused_result (tsi_stmt_ptr (i));
5890       break;
5891
5892     case COND_EXPR:
5893       c_warn_unused_result (&COND_EXPR_THEN (t));
5894       c_warn_unused_result (&COND_EXPR_ELSE (t));
5895       break;
5896     case BIND_EXPR:
5897       c_warn_unused_result (&BIND_EXPR_BODY (t));
5898       break;
5899     case TRY_FINALLY_EXPR:
5900     case TRY_CATCH_EXPR:
5901       c_warn_unused_result (&TREE_OPERAND (t, 0));
5902       c_warn_unused_result (&TREE_OPERAND (t, 1));
5903       break;
5904     case CATCH_EXPR:
5905       c_warn_unused_result (&CATCH_BODY (t));
5906       break;
5907     case EH_FILTER_EXPR:
5908       c_warn_unused_result (&EH_FILTER_FAILURE (t));
5909       break;
5910
5911     case CALL_EXPR:
5912       if (TREE_USED (t))
5913         break;
5914
5915       /* This is a naked call, as opposed to a CALL_EXPR nested inside
5916          a MODIFY_EXPR.  All calls whose value is ignored should be
5917          represented like this.  Look for the attribute.  */
5918       fdecl = get_callee_fndecl (t);
5919       if (fdecl)
5920         ftype = TREE_TYPE (fdecl);
5921       else
5922         {
5923           ftype = TREE_TYPE (TREE_OPERAND (t, 0));
5924           /* Look past pointer-to-function to the function type itself.  */
5925           ftype = TREE_TYPE (ftype);
5926         }
5927
5928       if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype)))
5929         {
5930           if (fdecl)
5931             warning (0, "%Hignoring return value of %qD, "
5932                      "declared with attribute warn_unused_result",
5933                      EXPR_LOCUS (t), fdecl);
5934           else
5935             warning (0, "%Hignoring return value of function "
5936                      "declared with attribute warn_unused_result",
5937                      EXPR_LOCUS (t));
5938         }
5939       break;
5940
5941     default:
5942       /* Not a container, not a call, or a call whose value is used.  */
5943       break;
5944     }
5945 }
5946
5947 /* Convert a character from the host to the target execution character
5948    set.  cpplib handles this, mostly.  */
5949
5950 HOST_WIDE_INT
5951 c_common_to_target_charset (HOST_WIDE_INT c)
5952 {
5953   /* Character constants in GCC proper are sign-extended under -fsigned-char,
5954      zero-extended under -fno-signed-char.  cpplib insists that characters
5955      and character constants are always unsigned.  Hence we must convert
5956      back and forth.  */
5957   cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1);
5958
5959   uc = cpp_host_to_exec_charset (parse_in, uc);
5960
5961   if (flag_signed_char)
5962     return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE)
5963                                >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE);
5964   else
5965     return uc;
5966 }
5967
5968 /* Build the result of __builtin_offsetof.  EXPR is a nested sequence of
5969    component references, with an INDIRECT_REF at the bottom; much like
5970    the traditional rendering of offsetof as a macro.  Returns the folded
5971    and properly cast result.  */
5972
5973 static tree
5974 fold_offsetof_1 (tree expr)
5975 {
5976   enum tree_code code = PLUS_EXPR;
5977   tree base, off, t;
5978
5979   switch (TREE_CODE (expr))
5980     {
5981     case ERROR_MARK:
5982       return expr;
5983
5984     case INDIRECT_REF:
5985       return size_zero_node;
5986
5987     case COMPONENT_REF:
5988       base = fold_offsetof_1 (TREE_OPERAND (expr, 0));
5989       if (base == error_mark_node)
5990         return base;
5991
5992       t = TREE_OPERAND (expr, 1);
5993       if (DECL_C_BIT_FIELD (t))
5994         {
5995           error ("attempt to take address of bit-field structure "
5996                  "member %qD", t);
5997           return error_mark_node;
5998         }
5999       off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t),
6000                         size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t), 1)
6001                                   / BITS_PER_UNIT));
6002       break;
6003
6004     case ARRAY_REF:
6005       base = fold_offsetof_1 (TREE_OPERAND (expr, 0));
6006       if (base == error_mark_node)
6007         return base;
6008
6009       t = TREE_OPERAND (expr, 1);
6010       if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0)
6011         {
6012           code = MINUS_EXPR;
6013           t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t);
6014         }
6015       t = convert (sizetype, t);
6016       off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
6017       break;
6018
6019     default:
6020       gcc_unreachable ();
6021     }
6022
6023   return size_binop (code, base, off);
6024 }
6025
6026 tree
6027 fold_offsetof (tree expr)
6028 {
6029   /* Convert back from the internal sizetype to size_t.  */
6030   return convert (size_type_node, fold_offsetof_1 (expr));
6031 }
6032
6033 /* Print an error message for an invalid lvalue.  USE says
6034    how the lvalue is being used and so selects the error message.  */
6035
6036 void
6037 lvalue_error (enum lvalue_use use)
6038 {
6039   switch (use)
6040     {
6041     case lv_assign:
6042       error ("lvalue required as left operand of assignment");
6043       break;
6044     case lv_increment:
6045       error ("lvalue required as increment operand");
6046       break;
6047     case lv_decrement:
6048       error ("lvalue required as decrement operand");
6049       break;
6050     case lv_addressof:
6051       error ("lvalue required as unary %<&%> operand");
6052       break;
6053     case lv_asm:
6054       error ("lvalue required in asm statement");
6055       break;
6056     default:
6057       gcc_unreachable ();
6058     }
6059 }
6060 \f
6061 /* *PTYPE is an incomplete array.  Complete it with a domain based on
6062    INITIAL_VALUE.  If INITIAL_VALUE is not present, use 1 if DO_DEFAULT
6063    is true.  Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered,
6064    2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty.  */
6065
6066 int
6067 complete_array_type (tree *ptype, tree initial_value, bool do_default)
6068 {
6069   tree maxindex, type, main_type, elt, unqual_elt;
6070   int failure = 0, quals;
6071
6072   maxindex = size_zero_node;
6073   if (initial_value)
6074     {
6075       if (TREE_CODE (initial_value) == STRING_CST)
6076         {
6077           int eltsize
6078             = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value)));
6079           maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1);
6080         }
6081       else if (TREE_CODE (initial_value) == CONSTRUCTOR)
6082         {
6083           VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (initial_value);
6084
6085           if (VEC_empty (constructor_elt, v))
6086             {
6087               if (pedantic)
6088                 failure = 3;
6089               maxindex = integer_minus_one_node;
6090             }
6091           else
6092             {
6093               tree curindex;
6094               unsigned HOST_WIDE_INT cnt;
6095               constructor_elt *ce;
6096
6097               if (VEC_index (constructor_elt, v, 0)->index)
6098                 maxindex = fold_convert (sizetype,
6099                                          VEC_index (constructor_elt,
6100                                                     v, 0)->index);
6101               curindex = maxindex;
6102
6103               for (cnt = 1;
6104                    VEC_iterate (constructor_elt, v, cnt, ce);
6105                    cnt++)
6106                 {
6107                   if (ce->index)
6108                     curindex = fold_convert (sizetype, ce->index);
6109                   else
6110                     curindex = size_binop (PLUS_EXPR, curindex, size_one_node);
6111
6112                   if (tree_int_cst_lt (maxindex, curindex))
6113                     maxindex = curindex;
6114                 }
6115             }
6116         }
6117       else
6118         {
6119           /* Make an error message unless that happened already.  */
6120           if (initial_value != error_mark_node)
6121             failure = 1;
6122         }
6123     }
6124   else
6125     {
6126       failure = 2;
6127       if (!do_default)
6128         return failure;
6129     }
6130
6131   type = *ptype;
6132   elt = TREE_TYPE (type);
6133   quals = TYPE_QUALS (strip_array_types (elt));
6134   if (quals == 0)
6135     unqual_elt = elt;
6136   else
6137     unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
6138
6139   /* Using build_distinct_type_copy and modifying things afterward instead
6140      of using build_array_type to create a new type preserves all of the
6141      TYPE_LANG_FLAG_? bits that the front end may have set.  */
6142   main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
6143   TREE_TYPE (main_type) = unqual_elt;
6144   TYPE_DOMAIN (main_type) = build_index_type (maxindex);
6145   layout_type (main_type);
6146
6147   if (quals == 0)
6148     type = main_type;
6149   else
6150     type = c_build_qualified_type (main_type, quals);
6151
6152   *ptype = type;
6153   return failure;
6154 }
6155
6156 \f
6157 /* Used to help initialize the builtin-types.def table.  When a type of
6158    the correct size doesn't exist, use error_mark_node instead of NULL.
6159    The later results in segfaults even when a decl using the type doesn't
6160    get invoked.  */
6161
6162 tree
6163 builtin_type_for_size (int size, bool unsignedp)
6164 {
6165   tree type = lang_hooks.types.type_for_size (size, unsignedp);
6166   return type ? type : error_mark_node;
6167 }
6168
6169 /* A helper function for resolve_overloaded_builtin in resolving the
6170    overloaded __sync_ builtins.  Returns a positive power of 2 if the
6171    first operand of PARAMS is a pointer to a supported data type.
6172    Returns 0 if an error is encountered.  */
6173
6174 static int
6175 sync_resolve_size (tree function, tree params)
6176 {
6177   tree type;
6178   int size;
6179
6180   if (params == NULL)
6181     {
6182       error ("too few arguments to function %qE", function);
6183       return 0;
6184     }
6185
6186   type = TREE_TYPE (TREE_VALUE (params));
6187   if (TREE_CODE (type) != POINTER_TYPE)
6188     goto incompatible;
6189
6190   type = TREE_TYPE (type);
6191   if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
6192     goto incompatible;
6193
6194   size = tree_low_cst (TYPE_SIZE_UNIT (type), 1);
6195   if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16)
6196     return size;
6197
6198  incompatible:
6199   error ("incompatible type for argument %d of %qE", 1, function);
6200   return 0;
6201 }
6202
6203 /* A helper function for resolve_overloaded_builtin.  Adds casts to
6204    PARAMS to make arguments match up with those of FUNCTION.  Drops
6205    the variadic arguments at the end.  Returns false if some error
6206    was encountered; true on success.  */
6207
6208 static bool
6209 sync_resolve_params (tree orig_function, tree function, tree params)
6210 {
6211   tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (function));
6212   tree ptype;
6213   int number;
6214
6215   /* We've declared the implementation functions to use "volatile void *"
6216      as the pointer parameter, so we shouldn't get any complaints from the
6217      call to check_function_arguments what ever type the user used.  */
6218   arg_types = TREE_CHAIN (arg_types);
6219   ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params)));
6220   number = 2;
6221
6222   /* For the rest of the values, we need to cast these to FTYPE, so that we
6223      don't get warnings for passing pointer types, etc.  */
6224   while (arg_types != void_list_node)
6225     {
6226       tree val;
6227
6228       params = TREE_CHAIN (params);
6229       if (params == NULL)
6230         {
6231           error ("too few arguments to function %qE", orig_function);
6232           return false;
6233         }
6234
6235       /* ??? Ideally for the first conversion we'd use convert_for_assignment
6236          so that we get warnings for anything that doesn't match the pointer
6237          type.  This isn't portable across the C and C++ front ends atm.  */
6238       val = TREE_VALUE (params);
6239       val = convert (ptype, val);
6240       val = convert (TREE_VALUE (arg_types), val);
6241       TREE_VALUE (params) = val;
6242
6243       arg_types = TREE_CHAIN (arg_types);
6244       number++;
6245     }
6246
6247   /* The definition of these primitives is variadic, with the remaining
6248      being "an optional list of variables protected by the memory barrier".
6249      No clue what that's supposed to mean, precisely, but we consider all
6250      call-clobbered variables to be protected so we're safe.  */
6251   TREE_CHAIN (params) = NULL;
6252
6253   return true;
6254 }
6255
6256 /* A helper function for resolve_overloaded_builtin.  Adds a cast to
6257    RESULT to make it match the type of the first pointer argument in
6258    PARAMS.  */
6259
6260 static tree
6261 sync_resolve_return (tree params, tree result)
6262 {
6263   tree ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params)));
6264   ptype = TYPE_MAIN_VARIANT (ptype);
6265   return convert (ptype, result);
6266 }
6267
6268 /* Some builtin functions are placeholders for other expressions.  This
6269    function should be called immediately after parsing the call expression
6270    before surrounding code has committed to the type of the expression.
6271
6272    FUNCTION is the DECL that has been invoked; it is known to be a builtin.
6273    PARAMS is the argument list for the call.  The return value is non-null
6274    when expansion is complete, and null if normal processing should
6275    continue.  */
6276
6277 tree
6278 resolve_overloaded_builtin (tree function, tree params)
6279 {
6280   enum built_in_function orig_code = DECL_FUNCTION_CODE (function);
6281   switch (DECL_BUILT_IN_CLASS (function))
6282     {
6283     case BUILT_IN_NORMAL:
6284       break;
6285     case BUILT_IN_MD:
6286       if (targetm.resolve_overloaded_builtin)
6287         return targetm.resolve_overloaded_builtin (function, params);
6288       else
6289         return NULL_TREE;
6290     default:
6291       return NULL_TREE;
6292     }
6293
6294   /* Handle BUILT_IN_NORMAL here.  */
6295   switch (orig_code)
6296     {
6297     case BUILT_IN_FETCH_AND_ADD_N:
6298     case BUILT_IN_FETCH_AND_SUB_N:
6299     case BUILT_IN_FETCH_AND_OR_N:
6300     case BUILT_IN_FETCH_AND_AND_N:
6301     case BUILT_IN_FETCH_AND_XOR_N:
6302     case BUILT_IN_FETCH_AND_NAND_N:
6303     case BUILT_IN_ADD_AND_FETCH_N:
6304     case BUILT_IN_SUB_AND_FETCH_N:
6305     case BUILT_IN_OR_AND_FETCH_N:
6306     case BUILT_IN_AND_AND_FETCH_N:
6307     case BUILT_IN_XOR_AND_FETCH_N:
6308     case BUILT_IN_NAND_AND_FETCH_N:
6309     case BUILT_IN_BOOL_COMPARE_AND_SWAP_N:
6310     case BUILT_IN_VAL_COMPARE_AND_SWAP_N:
6311     case BUILT_IN_LOCK_TEST_AND_SET_N:
6312     case BUILT_IN_LOCK_RELEASE_N:
6313       {
6314         int n = sync_resolve_size (function, params);
6315         tree new_function, result;
6316
6317         if (n == 0)
6318           return error_mark_node;
6319
6320         new_function = built_in_decls[orig_code + exact_log2 (n) + 1];
6321         if (!sync_resolve_params (function, new_function, params))
6322           return error_mark_node;
6323
6324         result = build_function_call (new_function, params);
6325         if (orig_code != BUILT_IN_BOOL_COMPARE_AND_SWAP_N
6326             && orig_code != BUILT_IN_LOCK_RELEASE_N)
6327           result = sync_resolve_return (params, result);
6328
6329         return result;
6330       }
6331
6332     default:
6333       return NULL_TREE;
6334     }
6335 }
6336
6337 /* Ignoring their sign, return true if two scalar types are the same.  */
6338 bool
6339 same_scalar_type_ignoring_signedness (tree t1, tree t2)
6340 {
6341   enum tree_code c1 = TREE_CODE (t1), c2 = TREE_CODE (t2);
6342
6343   gcc_assert ((c1 == INTEGER_TYPE || c1 == REAL_TYPE)
6344               && (c2 == INTEGER_TYPE || c2 == REAL_TYPE));
6345
6346   /* Equality works here because c_common_signed_type uses
6347      TYPE_MAIN_VARIANT.  */
6348   return lang_hooks.types.signed_type (t1)
6349     == lang_hooks.types.signed_type (t2);
6350 }
6351
6352 /* Check for missing format attributes on function pointers.  LTYPE is
6353    the new type or left-hand side type.  RTYPE is the old type or
6354    right-hand side type.  Returns TRUE if LTYPE is missing the desired
6355    attribute.  */
6356
6357 bool
6358 check_missing_format_attribute (tree ltype, tree rtype)
6359 {
6360   tree const ttr = TREE_TYPE (rtype), ttl = TREE_TYPE (ltype);
6361   tree ra;
6362
6363   for (ra = TYPE_ATTRIBUTES (ttr); ra; ra = TREE_CHAIN (ra))
6364     if (is_attribute_p ("format", TREE_PURPOSE (ra)))
6365       break;
6366   if (ra)
6367     {
6368       tree la;
6369       for (la = TYPE_ATTRIBUTES (ttl); la; la = TREE_CHAIN (la))
6370         if (is_attribute_p ("format", TREE_PURPOSE (la)))
6371           break;
6372       return !la;
6373     }
6374   else
6375     return false;
6376 }
6377
6378 /* Subscripting with type char is likely to lose on a machine where
6379    chars are signed.  So warn on any machine, but optionally.  Don't
6380    warn for unsigned char since that type is safe.  Don't warn for
6381    signed char because anyone who uses that must have done so
6382    deliberately. Furthermore, we reduce the false positive load by
6383    warning only for non-constant value of type char.  */
6384
6385 void
6386 warn_array_subscript_with_type_char (tree index)
6387 {
6388   if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node
6389       && TREE_CODE (index) != INTEGER_CST)
6390     warning (OPT_Wchar_subscripts, "array subscript has type %<char%>");
6391 }
6392
6393
6394 #include "gt-c-common.h"