gcc/langhooks.c

   1 /* Default language-specific hooks.
   2    Copyright (C) 2001-2015 Free Software Foundation, Inc.
   3    Contributed by Alexandre Oliva  <aoliva@redhat.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "intl.h"
  25 #include "tm.h"
  26 #include "toplev.h"
  27 #include "hash-set.h"
  28 #include "machmode.h"
  29 #include "vec.h"
  30 #include "double-int.h"
  31 #include "input.h"
  32 #include "alias.h"
  33 #include "symtab.h"
  34 #include "wide-int.h"
  35 #include "inchash.h"
  36 #include "tree.h"
  37 #include "stringpool.h"
  38 #include "attribs.h"
  39 #include "tree-inline.h"
  40 #include "gimplify.h"
  41 #include "rtl.h"
  42 #include "insn-config.h"
  43 #include "flags.h"
  44 #include "langhooks.h"
  45 #include "target.h"
  46 #include "langhooks-def.h"
  47 #include "diagnostic.h"
  48 #include "tree-diagnostic.h"
  49 #include "hash-map.h"
  50 #include "is-a.h"
  51 #include "plugin-api.h"
  52 #include "hard-reg-set.h"
  53 #include "input.h"
  54 #include "function.h"
  55 #include "ipa-ref.h"
  56 #include "cgraph.h"
  57 #include "timevar.h"
  58 #include "output.h"
  59
  60 /* Do nothing; in many cases the default hook.  */
  61
  62 void
  63 lhd_do_nothing (void)
  64 {
  65 }
  66
  67 /* Do nothing (tree).  */
  68
  69 void
  70 lhd_do_nothing_t (tree ARG_UNUSED (t))
  71 {
  72 }
  73
  74 /* Pass through (tree).  */
  75 tree
  76 lhd_pass_through_t (tree t)
  77 {
  78   return t;
  79 }
  80
  81 /* Do nothing (int, int, int).  Return NULL_TREE.  */
  82
  83 tree
  84 lhd_do_nothing_iii_return_null_tree (int ARG_UNUSED (i),
  85                                      int ARG_UNUSED (j),
  86                                      int ARG_UNUSED (k))
  87 {
  88   return NULL_TREE;
  89 }
  90
  91 /* Do nothing (function).  */
  92
  93 void
  94 lhd_do_nothing_f (struct function * ARG_UNUSED (f))
  95 {
  96 }
  97
  98 /* Do nothing (return NULL_TREE).  */
  99
 100 tree
 101 lhd_return_null_tree_v (void)
 102 {
 103   return NULL_TREE;
 104 }
 105
 106 /* Do nothing (return NULL_TREE).  */
 107
 108 tree
 109 lhd_return_null_tree (tree ARG_UNUSED (t))
 110 {
 111   return NULL_TREE;
 112 }
 113
 114 /* Do nothing (return NULL_TREE).  */
 115
 116 tree
 117 lhd_return_null_const_tree (const_tree ARG_UNUSED (t))
 118 {
 119   return NULL_TREE;
 120 }
 121
 122 /* The default post options hook.  */
 123
 124 bool
 125 lhd_post_options (const char ** ARG_UNUSED (pfilename))
 126 {
 127   /* Excess precision other than "fast" requires front-end
 128      support.  */
 129   flag_excess_precision_cmdline = EXCESS_PRECISION_FAST;
 130   return false;
 131 }
 132
 133 /* Called from by print-tree.c.  */
 134
 135 void
 136 lhd_print_tree_nothing (FILE * ARG_UNUSED (file),
 137                         tree ARG_UNUSED (node),
 138                         int ARG_UNUSED (indent))
 139 {
 140 }
 141
 142 /* Called from check_global_declarations.  */
 143
 144 bool
 145 lhd_warn_unused_global_decl (const_tree decl)
 146 {
 147   /* This is what used to exist in check_global_declarations.  Probably
 148      not many of these actually apply to non-C languages.  */
 149
 150   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
 151     return false;
 152   if (TREE_CODE (decl) == VAR_DECL && TREE_READONLY (decl))
 153     return false;
 154   if (DECL_IN_SYSTEM_HEADER (decl))
 155     return false;
 156
 157   return true;
 158 }
 159
 160 /* Set the DECL_ASSEMBLER_NAME for DECL.  */
 161 void
 162 lhd_set_decl_assembler_name (tree decl)
 163 {
 164   tree id;
 165
 166   /* set_decl_assembler_name may be called on TYPE_DECL to record ODR
 167      name for C++ types.  By default types have no ODR names.  */
 168   if (TREE_CODE (decl) == TYPE_DECL)
 169     return;
 170
 171   /* The language-independent code should never use the
 172      DECL_ASSEMBLER_NAME for lots of DECLs.  Only FUNCTION_DECLs and
 173      VAR_DECLs for variables with static storage duration need a real
 174      DECL_ASSEMBLER_NAME.  */
 175   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
 176               || (TREE_CODE (decl) == VAR_DECL
 177                   && (TREE_STATIC (decl)
 178                       || DECL_EXTERNAL (decl)
 179                       || TREE_PUBLIC (decl))));
 180
 181   /* By default, assume the name to use in assembly code is the same
 182      as that used in the source language.  (That's correct for C, and
 183      GCC used to set DECL_ASSEMBLER_NAME to the same value as
 184      DECL_NAME in build_decl, so this choice provides backwards
 185      compatibility with existing front-ends.  This assumption is wrapped
 186      in a target hook, to allow for target-specific modification of the
 187      identifier.
 188
 189      Can't use just the variable's own name for a variable whose scope
 190      is less than the whole compilation.  Concatenate a distinguishing
 191      number - we use the DECL_UID.  */
 192
 193   if (TREE_PUBLIC (decl) || DECL_FILE_SCOPE_P (decl))
 194     id = targetm.mangle_decl_assembler_name (decl, DECL_NAME (decl));
 195   else
 196     {
 197       const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
 198       char *label;
 199
 200       ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
 201       id = get_identifier (label);
 202     }
 203   SET_DECL_ASSEMBLER_NAME (decl, id);
 204
 205 }
 206
 207 /* Type promotion for variable arguments.  */
 208 tree
 209 lhd_type_promotes_to (tree ARG_UNUSED (type))
 210 {
 211   gcc_unreachable ();
 212 }
 213
 214 /* Registration of machine- or os-specific builtin types.  */
 215 void
 216 lhd_register_builtin_type (tree ARG_UNUSED (type),
 217                            const char * ARG_UNUSED (name))
 218 {
 219 }
 220
 221 /* Invalid use of an incomplete type.  */
 222 void
 223 lhd_incomplete_type_error (const_tree ARG_UNUSED (value), const_tree type)
 224 {
 225   gcc_assert (TREE_CODE (type) == ERROR_MARK);
 226   return;
 227 }
 228
 229 /* Provide a default routine for alias sets that always returns -1.  This
 230    is used by languages that don't need to do anything special.  */
 231
 232 alias_set_type
 233 lhd_get_alias_set (tree ARG_UNUSED (t))
 234 {
 235   return -1;
 236 }
 237
 238 /* This is the default decl_printable_name function.  */
 239
 240 const char *
 241 lhd_decl_printable_name (tree decl, int ARG_UNUSED (verbosity))
 242 {
 243   gcc_assert (decl && DECL_NAME (decl));
 244   return IDENTIFIER_POINTER (DECL_NAME (decl));
 245 }
 246
 247 /* This is the default dwarf_name function.  */
 248
 249 const char *
 250 lhd_dwarf_name (tree t, int verbosity)
 251 {
 252   gcc_assert (DECL_P (t));
 253
 254   return lang_hooks.decl_printable_name (t, verbosity);
 255 }
 256
 257 /* This compares two types for equivalence ("compatible" in C-based languages).
 258    This routine should only return 1 if it is sure.  It should not be used
 259    in contexts where erroneously returning 0 causes problems.  */
 260
 261 int
 262 lhd_types_compatible_p (tree x, tree y)
 263 {
 264   return TYPE_MAIN_VARIANT (x) == TYPE_MAIN_VARIANT (y);
 265 }
 266
 267 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
 268    nodes.  Returns nonzero if it does not want the usual dumping of the
 269    second argument.  */
 270
 271 bool
 272 lhd_tree_dump_dump_tree (void *di ATTRIBUTE_UNUSED, tree t ATTRIBUTE_UNUSED)
 273 {
 274   return false;
 275 }
 276
 277 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
 278    language-specific way.  */
 279
 280 int
 281 lhd_tree_dump_type_quals (const_tree t)
 282 {
 283   return TYPE_QUALS (t);
 284 }
 285
 286 /* lang_hooks.gimplify_expr re-writes *EXPR_P into GIMPLE form.  */
 287
 288 int
 289 lhd_gimplify_expr (tree *expr_p ATTRIBUTE_UNUSED,
 290                    gimple_seq *pre_p ATTRIBUTE_UNUSED,
 291                    gimple_seq *post_p ATTRIBUTE_UNUSED)
 292 {
 293   return GS_UNHANDLED;
 294 }
 295
 296 /* lang_hooks.tree_size: Determine the size of a tree with code C,
 297    which is a language-specific tree code in category tcc_constant or
 298    tcc_exceptional.  The default expects never to be called.  */
 299 size_t
 300 lhd_tree_size (enum tree_code c ATTRIBUTE_UNUSED)
 301 {
 302   gcc_unreachable ();
 303 }
 304
 305 /* Return true if decl, which is a function decl, may be called by a
 306    sibcall.  */
 307
 308 bool
 309 lhd_decl_ok_for_sibcall (const_tree decl ATTRIBUTE_UNUSED)
 310 {
 311   return true;
 312 }
 313
 314 /* lang_hooks.decls.final_write_globals: perform final processing on
 315    global variables.  */
 316 void
 317 write_global_declarations (void)
 318 {
 319   tree globals, decl, *vec;
 320   int len, i;
 321
 322   timevar_start (TV_PHASE_DEFERRED);
 323   /* Really define vars that have had only a tentative definition.
 324      Really output inline functions that must actually be callable
 325      and have not been output so far.  */
 326
 327   globals = lang_hooks.decls.getdecls ();
 328   len = list_length (globals);
 329   vec = XNEWVEC (tree, len);
 330
 331   /* Process the decls in reverse order--earliest first.
 332      Put them into VEC from back to front, then take out from front.  */
 333
 334   for (i = 0, decl = globals; i < len; i++, decl = DECL_CHAIN (decl))
 335     vec[len - i - 1] = decl;
 336
 337   wrapup_global_declarations (vec, len);
 338   check_global_declarations (vec, len);
 339   timevar_stop (TV_PHASE_DEFERRED);
 340
 341   timevar_start (TV_PHASE_OPT_GEN);
 342   /* This lang hook is dual-purposed, and also finalizes the
 343      compilation unit.  */
 344   symtab->finalize_compilation_unit ();
 345   timevar_stop (TV_PHASE_OPT_GEN);
 346
 347   timevar_start (TV_PHASE_DBGINFO);
 348   emit_debug_global_declarations (vec, len);
 349   timevar_stop (TV_PHASE_DBGINFO);
 350
 351   /* Clean up.  */
 352   free (vec);
 353 }
 354
 355 /* Called to perform language-specific initialization of CTX.  */
 356 void
 357 lhd_initialize_diagnostics (diagnostic_context *ctx ATTRIBUTE_UNUSED)
 358 {
 359 }
 360
 361 /* Called to perform language-specific options initialization.  */
 362 void
 363 lhd_init_options (unsigned int decoded_options_count ATTRIBUTE_UNUSED,
 364                   struct cl_decoded_option *decoded_options ATTRIBUTE_UNUSED)
 365 {
 366 }
 367
 368 /* By default, always complain about options for the wrong language.  */
 369 bool
 370 lhd_complain_wrong_lang_p (const struct cl_option *option ATTRIBUTE_UNUSED)
 371 {
 372   return true;
 373 }
 374
 375 /* By default, no language-specific options are valid.  */
 376 bool
 377 lhd_handle_option (size_t code ATTRIBUTE_UNUSED,
 378                    const char *arg ATTRIBUTE_UNUSED,
 379                    int value ATTRIBUTE_UNUSED, int kind ATTRIBUTE_UNUSED,
 380                    location_t loc ATTRIBUTE_UNUSED,
 381                    const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
 382 {
 383   return false;
 384 }
 385
 386 /* The default function to print out name of current function that caused
 387    an error.  */
 388 void
 389 lhd_print_error_function (diagnostic_context *context, const char *file,
 390                           diagnostic_info *diagnostic)
 391 {
 392   if (diagnostic_last_function_changed (context, diagnostic))
 393     {
 394       const char *old_prefix = context->printer->prefix;
 395       tree abstract_origin = diagnostic_abstract_origin (diagnostic);
 396       char *new_prefix = (file && abstract_origin == NULL)
 397                          ? file_name_as_prefix (context, file) : NULL;
 398
 399       pp_set_prefix (context->printer, new_prefix);
 400
 401       if (current_function_decl == NULL)
 402         pp_printf (context->printer, _("At top level:"));
 403       else
 404         {
 405           tree fndecl, ao;
 406
 407           if (abstract_origin)
 408             {
 409               ao = BLOCK_ABSTRACT_ORIGIN (abstract_origin);
 410               while (TREE_CODE (ao) == BLOCK
 411                      && BLOCK_ABSTRACT_ORIGIN (ao)
 412                      && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
 413                 ao = BLOCK_ABSTRACT_ORIGIN (ao);
 414               gcc_assert (TREE_CODE (ao) == FUNCTION_DECL);
 415               fndecl = ao;
 416             }
 417           else
 418             fndecl = current_function_decl;
 419
 420           if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
 421             pp_printf
 422               (context->printer, _("In member function %qs"),
 423                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 424           else
 425             pp_printf
 426               (context->printer, _("In function %qs"),
 427                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 428
 429           while (abstract_origin)
 430             {
 431               location_t *locus;
 432               tree block = abstract_origin;
 433
 434               locus = &BLOCK_SOURCE_LOCATION (block);
 435               fndecl = NULL;
 436               block = BLOCK_SUPERCONTEXT (block);
 437               while (block && TREE_CODE (block) == BLOCK
 438                      && BLOCK_ABSTRACT_ORIGIN (block))
 439                 {
 440                   ao = BLOCK_ABSTRACT_ORIGIN (block);
 441
 442                   while (TREE_CODE (ao) == BLOCK
 443                          && BLOCK_ABSTRACT_ORIGIN (ao)
 444                          && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
 445                     ao = BLOCK_ABSTRACT_ORIGIN (ao);
 446
 447                   if (TREE_CODE (ao) == FUNCTION_DECL)
 448                     {
 449                       fndecl = ao;
 450                       break;
 451                     }
 452                   else if (TREE_CODE (ao) != BLOCK)
 453                     break;
 454
 455                   block = BLOCK_SUPERCONTEXT (block);
 456                 }
 457               if (fndecl)
 458                 abstract_origin = block;
 459               else
 460                 {
 461                   while (block && TREE_CODE (block) == BLOCK)
 462                     block = BLOCK_SUPERCONTEXT (block);
 463
 464                   if (block && TREE_CODE (block) == FUNCTION_DECL)
 465                     fndecl = block;
 466                   abstract_origin = NULL;
 467                 }
 468               if (fndecl)
 469                 {
 470                   expanded_location s = expand_location (*locus);
 471                   pp_comma (context->printer);
 472                   pp_newline (context->printer);
 473                   if (s.file != NULL)
 474                     {
 475                       if (context->show_column)
 476                         pp_printf (context->printer,
 477                                    _("    inlined from %qs at %r%s:%d:%d%R"),
 478                                    identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
 479                                    "locus", s.file, s.line, s.column);
 480                       else
 481                         pp_printf (context->printer,
 482                                    _("    inlined from %qs at %r%s:%d%R"),
 483                                    identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
 484                                    "locus", s.file, s.line);
 485
 486                     }
 487                   else
 488                     pp_printf (context->printer, _("    inlined from %qs"),
 489                                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 490                 }
 491             }
 492           pp_colon (context->printer);
 493         }
 494
 495       diagnostic_set_last_function (context, diagnostic);
 496       pp_newline_and_flush (context->printer);
 497       context->printer->prefix = old_prefix;
 498       free ((char*) new_prefix);
 499     }
 500 }
 501
 502 tree
 503 lhd_make_node (enum tree_code code)
 504 {
 505   return make_node (code);
 506 }
 507
 508 HOST_WIDE_INT
 509 lhd_to_target_charset (HOST_WIDE_INT c)
 510 {
 511   return c;
 512 }
 513
 514 tree
 515 lhd_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED, bool *se ATTRIBUTE_UNUSED)
 516 {
 517   return expr;
 518 }
 519
 520 /* Return sharing kind if OpenMP sharing attribute of DECL is
 521    predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 522
 523 enum omp_clause_default_kind
 524 lhd_omp_predetermined_sharing (tree decl ATTRIBUTE_UNUSED)
 525 {
 526   if (DECL_ARTIFICIAL (decl))
 527     return OMP_CLAUSE_DEFAULT_SHARED;
 528   return OMP_CLAUSE_DEFAULT_UNSPECIFIED;
 529 }
 530
 531 /* Generate code to copy SRC to DST.  */
 532
 533 tree
 534 lhd_omp_assignment (tree clause ATTRIBUTE_UNUSED, tree dst, tree src)
 535 {
 536   return build2 (MODIFY_EXPR, TREE_TYPE (dst), dst, src);
 537 }
 538
 539 /* Finalize clause C.  */
 540
 541 void
 542 lhd_omp_finish_clause (tree, gimple_seq *)
 543 {
 544 }
 545
 546 /* Register language specific type size variables as potentially OpenMP
 547    firstprivate variables.  */
 548
 549 void
 550 lhd_omp_firstprivatize_type_sizes (struct gimplify_omp_ctx *c ATTRIBUTE_UNUSED,
 551                                    tree t ATTRIBUTE_UNUSED)
 552 {
 553 }
 554
 555 /* Return true if TYPE is an OpenMP mappable type.  */
 556
 557 bool
 558 lhd_omp_mappable_type (tree type)
 559 {
 560   /* Mappable type has to be complete.  */
 561   if (type == error_mark_node || !COMPLETE_TYPE_P (type))
 562     return false;
 563   return true;
 564 }
 565
 566 /* Common function for add_builtin_function and
 567    add_builtin_function_ext_scope.  */
 568 static tree
 569 add_builtin_function_common (const char *name,
 570                              tree type,
 571                              int function_code,
 572                              enum built_in_class cl,
 573                              const char *library_name,
 574                              tree attrs,
 575                              tree (*hook) (tree))
 576 {
 577   tree   id = get_identifier (name);
 578   tree decl = build_decl (BUILTINS_LOCATION, FUNCTION_DECL, id, type);
 579
 580   TREE_PUBLIC (decl)         = 1;
 581   DECL_EXTERNAL (decl)       = 1;
 582   DECL_BUILT_IN_CLASS (decl) = cl;
 583
 584   DECL_FUNCTION_CODE (decl)  = (enum built_in_function) function_code;
 585
 586   /* DECL_FUNCTION_CODE is a bitfield; verify that the value fits.  */
 587   gcc_assert (DECL_FUNCTION_CODE (decl) == function_code);
 588
 589   if (library_name)
 590     {
 591       tree libname = get_identifier (library_name);
 592       SET_DECL_ASSEMBLER_NAME (decl, libname);
 593     }
 594
 595   /* Possibly apply some default attributes to this built-in function.  */
 596   if (attrs)
 597     decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
 598   else
 599     decl_attributes (&decl, NULL_TREE, 0);
 600
 601   return hook (decl);
 602
 603 }
 604
 605 /* Create a builtin function.  */
 606
 607 tree
 608 add_builtin_function (const char *name,
 609                       tree type,
 610                       int function_code,
 611                       enum built_in_class cl,
 612                       const char *library_name,
 613                       tree attrs)
 614 {
 615   return add_builtin_function_common (name, type, function_code, cl,
 616                                       library_name, attrs,
 617                                       lang_hooks.builtin_function);
 618 }
 619
 620 /* Like add_builtin_function, but make sure the scope is the external scope.
 621    This is used to delay putting in back end builtin functions until the ISA
 622    that defines the builtin is declared via function specific target options,
 623    which can save memory for machines like the x86_64 that have multiple ISAs.
 624    If this points to the same function as builtin_function, the backend must
 625    add all of the builtins at program initialization time.  */
 626
 627 tree
 628 add_builtin_function_ext_scope (const char *name,
 629                                 tree type,
 630                                 int function_code,
 631                                 enum built_in_class cl,
 632                                 const char *library_name,
 633                                 tree attrs)
 634 {
 635   return add_builtin_function_common (name, type, function_code, cl,
 636                                       library_name, attrs,
 637                                       lang_hooks.builtin_function_ext_scope);
 638 }
 639
 640 tree
 641 lhd_builtin_function (tree decl)
 642 {
 643   lang_hooks.decls.pushdecl (decl);
 644   return decl;
 645 }
 646
 647 /* Create a builtin type.  */
 648
 649 tree
 650 add_builtin_type (const char *name, tree type)
 651 {
 652   tree   id = get_identifier (name);
 653   tree decl = build_decl (BUILTINS_LOCATION, TYPE_DECL, id, type);
 654   return lang_hooks.decls.pushdecl (decl);
 655 }
 656
 657 /* LTO hooks.  */
 658
 659 /* Used to save and restore any previously active section.  */
 660 static section *saved_section;
 661
 662
 663 /* Begin a new LTO output section named NAME.  This default implementation
 664    saves the old section and emits assembly code to switch to the new
 665    section.  */
 666
 667 void
 668 lhd_begin_section (const char *name)
 669 {
 670   section *section;
 671
 672   /* Save the old section so we can restore it in lto_end_asm_section.  */
 673   gcc_assert (!saved_section);
 674   saved_section = in_section;
 675   if (!saved_section)
 676     saved_section = text_section;
 677
 678   /* Create a new section and switch to it.  */
 679   section = get_section (name, SECTION_DEBUG | SECTION_EXCLUDE, NULL);
 680   switch_to_section (section);
 681 }
 682
 683
 684 /* Write DATA of length LEN to the current LTO output section.  This default
 685    implementation just calls assemble_string.  */
 686
 687 void
 688 lhd_append_data (const void *data, size_t len, void *)
 689 {
 690   if (data)
 691     assemble_string ((const char *)data, len);
 692 }
 693
 694
 695 /* Finish the current LTO output section.  This default implementation emits
 696    assembly code to switch to any section previously saved by
 697    lhd_begin_section.  */
 698
 699 void
 700 lhd_end_section (void)
 701 {
 702   if (saved_section)
 703     {
 704       switch_to_section (saved_section);
 705       saved_section = NULL;
 706     }
 707 }
 708
 709 /* Default implementation of enum_underlying_base_type using type_for_size.  */
 710
 711 tree
 712 lhd_enum_underlying_base_type (const_tree enum_type)
 713 {
 714   return lang_hooks.types.type_for_size (TYPE_PRECISION (enum_type),
 715                                          TYPE_UNSIGNED (enum_type));
 716 }
 717
 718 /* Returns true if the current lang_hooks represents the GNU C frontend.  */
 719
 720 bool
 721 lang_GNU_C (void)
 722 {
 723   return (strncmp (lang_hooks.name, "GNU C", 5) == 0
 724           && (lang_hooks.name[5] == '\0' || ISDIGIT (lang_hooks.name[5])));
 725 }
 726
 727 /* Returns true if the current lang_hooks represents the GNU C++ frontend.  */
 728
 729 bool
 730 lang_GNU_CXX (void)
 731 {
 732   return strncmp (lang_hooks.name, "GNU C++", 7) == 0;
 733 }