gcc/langhooks.c

   1 /* Default language-specific hooks.
   2    Copyright (C) 2001-2018 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 "target.h"
  25 #include "rtl.h"
  26 #include "tree.h"
  27 #include "timevar.h"
  28 #include "stringpool.h"
  29 #include "diagnostic.h"
  30 #include "intl.h"
  31 #include "toplev.h"
  32 #include "attribs.h"
  33 #include "gimplify.h"
  34 #include "langhooks.h"
  35 #include "tree-diagnostic.h"
  36 #include "output.h"
  37 #include "timevar.h"
  38
  39 /* Do nothing; in many cases the default hook.  */
  40
  41 void
  42 lhd_do_nothing (void)
  43 {
  44 }
  45
  46 /* Do nothing (tree).  */
  47
  48 void
  49 lhd_do_nothing_t (tree ARG_UNUSED (t))
  50 {
  51 }
  52
  53 /* Pass through (tree).  */
  54 tree
  55 lhd_pass_through_t (tree t)
  56 {
  57   return t;
  58 }
  59
  60 /* Do nothing (int, int, int).  Return NULL_TREE.  */
  61
  62 tree
  63 lhd_do_nothing_iii_return_null_tree (int ARG_UNUSED (i),
  64                                      int ARG_UNUSED (j),
  65                                      int ARG_UNUSED (k))
  66 {
  67   return NULL_TREE;
  68 }
  69
  70 /* Do nothing (function).  */
  71
  72 void
  73 lhd_do_nothing_f (struct function * ARG_UNUSED (f))
  74 {
  75 }
  76
  77 /* Do nothing (return NULL_TREE).  */
  78
  79 tree
  80 lhd_return_null_tree (tree ARG_UNUSED (t))
  81 {
  82   return NULL_TREE;
  83 }
  84
  85 /* Do nothing (return NULL_TREE).  */
  86
  87 tree
  88 lhd_return_null_const_tree (const_tree ARG_UNUSED (t))
  89 {
  90   return NULL_TREE;
  91 }
  92
  93 /* The default post options hook.  */
  94
  95 bool
  96 lhd_post_options (const char ** ARG_UNUSED (pfilename))
  97 {
  98   /* Excess precision other than "fast" requires front-end
  99      support.  */
 100   flag_excess_precision_cmdline = EXCESS_PRECISION_FAST;
 101   return false;
 102 }
 103
 104 /* Called from by print-tree.c.  */
 105
 106 void
 107 lhd_print_tree_nothing (FILE * ARG_UNUSED (file),
 108                         tree ARG_UNUSED (node),
 109                         int ARG_UNUSED (indent))
 110 {
 111 }
 112
 113 /* Called from check_global_declaration.  */
 114
 115 bool
 116 lhd_warn_unused_global_decl (const_tree decl)
 117 {
 118   /* This is what used to exist in check_global_declaration.  Probably
 119      not many of these actually apply to non-C languages.  */
 120
 121   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
 122     return false;
 123   if (VAR_P (decl) && TREE_READONLY (decl))
 124     return false;
 125   if (DECL_IN_SYSTEM_HEADER (decl))
 126     return false;
 127
 128   return true;
 129 }
 130
 131 /* Set the DECL_ASSEMBLER_NAME for DECL.  */
 132 void
 133 lhd_set_decl_assembler_name (tree decl)
 134 {
 135   tree id;
 136
 137   /* set_decl_assembler_name may be called on TYPE_DECL to record ODR
 138      name for C++ types.  By default types have no ODR names.  */
 139   if (TREE_CODE (decl) == TYPE_DECL)
 140     return;
 141
 142   /* The language-independent code should never use the
 143      DECL_ASSEMBLER_NAME for lots of DECLs.  Only FUNCTION_DECLs and
 144      VAR_DECLs for variables with static storage duration need a real
 145      DECL_ASSEMBLER_NAME.  */
 146   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
 147               || (VAR_P (decl)
 148                   && (TREE_STATIC (decl)
 149                       || DECL_EXTERNAL (decl)
 150                       || TREE_PUBLIC (decl))));
 151
 152   /* By default, assume the name to use in assembly code is the same
 153      as that used in the source language.  (That's correct for C, and
 154      GCC used to set DECL_ASSEMBLER_NAME to the same value as
 155      DECL_NAME in build_decl, so this choice provides backwards
 156      compatibility with existing front-ends.  This assumption is wrapped
 157      in a target hook, to allow for target-specific modification of the
 158      identifier.
 159
 160      Can't use just the variable's own name for a variable whose scope
 161      is less than the whole compilation.  Concatenate a distinguishing
 162      number - we use the DECL_UID.  */
 163
 164   if (TREE_PUBLIC (decl) || DECL_FILE_SCOPE_P (decl))
 165     id = targetm.mangle_decl_assembler_name (decl, DECL_NAME (decl));
 166   else
 167     {
 168       const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
 169       char *label;
 170
 171       ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
 172       id = get_identifier (label);
 173     }
 174
 175   SET_DECL_ASSEMBLER_NAME (decl, id);
 176 }
 177
 178 /* Forcibly overwrite the DECL_ASSEMBLER_NAME for DECL to NAME.  */
 179 void
 180 lhd_overwrite_decl_assembler_name (tree decl, tree name)
 181 {
 182   DECL_ASSEMBLER_NAME_RAW (decl) = name;
 183 }
 184
 185 /* Type promotion for variable arguments.  */
 186 tree
 187 lhd_type_promotes_to (tree ARG_UNUSED (type))
 188 {
 189   gcc_unreachable ();
 190 }
 191
 192 /* Registration of machine- or os-specific builtin types.  */
 193 void
 194 lhd_register_builtin_type (tree ARG_UNUSED (type),
 195                            const char * ARG_UNUSED (name))
 196 {
 197 }
 198
 199 /* Invalid use of an incomplete type.  */
 200 void
 201 lhd_incomplete_type_error (location_t ARG_UNUSED (loc),
 202                            const_tree ARG_UNUSED (value), const_tree type)
 203 {
 204   gcc_assert (TREE_CODE (type) == ERROR_MARK);
 205   return;
 206 }
 207
 208 /* Provide a default routine for alias sets that always returns -1.  This
 209    is used by languages that don't need to do anything special.  */
 210
 211 alias_set_type
 212 lhd_get_alias_set (tree ARG_UNUSED (t))
 213 {
 214   return -1;
 215 }
 216
 217 /* This is the default decl_printable_name function.  */
 218
 219 const char *
 220 lhd_decl_printable_name (tree decl, int ARG_UNUSED (verbosity))
 221 {
 222   gcc_assert (decl && DECL_NAME (decl));
 223   return IDENTIFIER_POINTER (DECL_NAME (decl));
 224 }
 225
 226 /* This is the default dwarf_name function.  */
 227
 228 const char *
 229 lhd_dwarf_name (tree t, int verbosity)
 230 {
 231   gcc_assert (DECL_P (t));
 232
 233   return lang_hooks.decl_printable_name (t, verbosity);
 234 }
 235
 236 /* This compares two types for equivalence ("compatible" in C-based languages).
 237    This routine should only return 1 if it is sure.  It should not be used
 238    in contexts where erroneously returning 0 causes problems.  */
 239
 240 int
 241 lhd_types_compatible_p (tree x, tree y)
 242 {
 243   return TYPE_MAIN_VARIANT (x) == TYPE_MAIN_VARIANT (y);
 244 }
 245
 246 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
 247    nodes.  Returns nonzero if it does not want the usual dumping of the
 248    second argument.  */
 249
 250 bool
 251 lhd_tree_dump_dump_tree (void *di ATTRIBUTE_UNUSED, tree t ATTRIBUTE_UNUSED)
 252 {
 253   return false;
 254 }
 255
 256 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
 257    language-specific way.  */
 258
 259 int
 260 lhd_tree_dump_type_quals (const_tree t)
 261 {
 262   return TYPE_QUALS (t);
 263 }
 264
 265 /* lang_hooks.gimplify_expr re-writes *EXPR_P into GIMPLE form.  */
 266
 267 int
 268 lhd_gimplify_expr (tree *expr_p ATTRIBUTE_UNUSED,
 269                    gimple_seq *pre_p ATTRIBUTE_UNUSED,
 270                    gimple_seq *post_p ATTRIBUTE_UNUSED)
 271 {
 272   return GS_UNHANDLED;
 273 }
 274
 275 /* lang_hooks.tree_size: Determine the size of a tree with code C,
 276    which is a language-specific tree code in category tcc_constant,
 277    tcc_exceptional or tcc_type.  The default expects never to be called.  */
 278 size_t
 279 lhd_tree_size (enum tree_code c ATTRIBUTE_UNUSED)
 280 {
 281   gcc_unreachable ();
 282 }
 283
 284 /* Return true if decl, which is a function decl, may be called by a
 285    sibcall.  */
 286
 287 bool
 288 lhd_decl_ok_for_sibcall (const_tree decl ATTRIBUTE_UNUSED)
 289 {
 290   return true;
 291 }
 292
 293 /* Generic global declaration processing.  This is meant to be called
 294    by the front-ends at the end of parsing.  C/C++ do their own thing,
 295    but other front-ends may call this.  */
 296
 297 void
 298 global_decl_processing (void)
 299 {
 300   tree globals, decl, *vec;
 301   int len, i;
 302
 303   timevar_stop (TV_PHASE_PARSING);
 304   timevar_start (TV_PHASE_DEFERRED);
 305   /* Really define vars that have had only a tentative definition.
 306      Really output inline functions that must actually be callable
 307      and have not been output so far.  */
 308
 309   globals = lang_hooks.decls.getdecls ();
 310   len = list_length (globals);
 311   vec = XNEWVEC (tree, len);
 312
 313   /* Process the decls in reverse order--earliest first.
 314      Put them into VEC from back to front, then take out from front.  */
 315
 316   for (i = 0, decl = globals; i < len; i++, decl = DECL_CHAIN (decl))
 317     vec[len - i - 1] = decl;
 318
 319   wrapup_global_declarations (vec, len);
 320   timevar_stop (TV_PHASE_DEFERRED);
 321
 322   timevar_start (TV_PHASE_PARSING);
 323   free (vec);
 324 }
 325
 326 /* Called to perform language-specific initialization of CTX.  */
 327 void
 328 lhd_initialize_diagnostics (diagnostic_context *ctx ATTRIBUTE_UNUSED)
 329 {
 330 }
 331
 332 /* Called to register dumps.  */
 333 void
 334 lhd_register_dumps (gcc::dump_manager *)
 335 {
 336 }
 337
 338 /* Called to perform language-specific options initialization.  */
 339 void
 340 lhd_init_options (unsigned int decoded_options_count ATTRIBUTE_UNUSED,
 341                   struct cl_decoded_option *decoded_options ATTRIBUTE_UNUSED)
 342 {
 343 }
 344
 345 /* By default, always complain about options for the wrong language.  */
 346 bool
 347 lhd_complain_wrong_lang_p (const struct cl_option *option ATTRIBUTE_UNUSED)
 348 {
 349   return true;
 350 }
 351
 352 /* By default, no language-specific options are valid.  */
 353 bool
 354 lhd_handle_option (size_t code ATTRIBUTE_UNUSED,
 355                    const char *arg ATTRIBUTE_UNUSED,
 356                    int value ATTRIBUTE_UNUSED, int kind ATTRIBUTE_UNUSED,
 357                    location_t loc ATTRIBUTE_UNUSED,
 358                    const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
 359 {
 360   return false;
 361 }
 362
 363 /* The default function to print out name of current function that caused
 364    an error.  */
 365 void
 366 lhd_print_error_function (diagnostic_context *context, const char *file,
 367                           diagnostic_info *diagnostic)
 368 {
 369   if (diagnostic_last_function_changed (context, diagnostic))
 370     {
 371       const char *old_prefix = context->printer->prefix;
 372       tree abstract_origin = diagnostic_abstract_origin (diagnostic);
 373       char *new_prefix = (file && abstract_origin == NULL)
 374                          ? file_name_as_prefix (context, file) : NULL;
 375
 376       pp_set_prefix (context->printer, new_prefix);
 377
 378       if (current_function_decl == NULL)
 379         pp_printf (context->printer, _("At top level:"));
 380       else
 381         {
 382           tree fndecl, ao;
 383
 384           if (abstract_origin)
 385             {
 386               ao = BLOCK_ABSTRACT_ORIGIN (abstract_origin);
 387               while (TREE_CODE (ao) == BLOCK
 388                      && BLOCK_ABSTRACT_ORIGIN (ao)
 389                      && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
 390                 ao = BLOCK_ABSTRACT_ORIGIN (ao);
 391               gcc_assert (TREE_CODE (ao) == FUNCTION_DECL);
 392               fndecl = ao;
 393             }
 394           else
 395             fndecl = current_function_decl;
 396
 397           if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
 398             pp_printf
 399               (context->printer, _("In member function %qs"),
 400                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 401           else
 402             pp_printf
 403               (context->printer, _("In function %qs"),
 404                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 405
 406           while (abstract_origin)
 407             {
 408               location_t *locus;
 409               tree block = abstract_origin;
 410
 411               locus = &BLOCK_SOURCE_LOCATION (block);
 412               fndecl = NULL;
 413               block = BLOCK_SUPERCONTEXT (block);
 414               while (block && TREE_CODE (block) == BLOCK
 415                      && BLOCK_ABSTRACT_ORIGIN (block))
 416                 {
 417                   ao = BLOCK_ABSTRACT_ORIGIN (block);
 418
 419                   while (TREE_CODE (ao) == BLOCK
 420                          && BLOCK_ABSTRACT_ORIGIN (ao)
 421                          && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
 422                     ao = BLOCK_ABSTRACT_ORIGIN (ao);
 423
 424                   if (TREE_CODE (ao) == FUNCTION_DECL)
 425                     {
 426                       fndecl = ao;
 427                       break;
 428                     }
 429                   else if (TREE_CODE (ao) != BLOCK)
 430                     break;
 431
 432                   block = BLOCK_SUPERCONTEXT (block);
 433                 }
 434               if (fndecl)
 435                 abstract_origin = block;
 436               else
 437                 {
 438                   while (block && TREE_CODE (block) == BLOCK)
 439                     block = BLOCK_SUPERCONTEXT (block);
 440
 441                   if (block && TREE_CODE (block) == FUNCTION_DECL)
 442                     fndecl = block;
 443                   abstract_origin = NULL;
 444                 }
 445               if (fndecl)
 446                 {
 447                   expanded_location s = expand_location (*locus);
 448                   pp_comma (context->printer);
 449                   pp_newline (context->printer);
 450                   if (s.file != NULL)
 451                     {
 452                       if (context->show_column)
 453                         pp_printf (context->printer,
 454                                    _("    inlined from %qs at %r%s:%d:%d%R"),
 455                                    identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
 456                                    "locus", s.file, s.line, s.column);
 457                       else
 458                         pp_printf (context->printer,
 459                                    _("    inlined from %qs at %r%s:%d%R"),
 460                                    identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
 461                                    "locus", s.file, s.line);
 462
 463                     }
 464                   else
 465                     pp_printf (context->printer, _("    inlined from %qs"),
 466                                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 467                 }
 468             }
 469           pp_colon (context->printer);
 470         }
 471
 472       diagnostic_set_last_function (context, diagnostic);
 473       pp_newline_and_flush (context->printer);
 474       context->printer->prefix = old_prefix;
 475       free ((char*) new_prefix);
 476     }
 477 }
 478
 479 tree
 480 lhd_make_node (enum tree_code code)
 481 {
 482   return make_node (code);
 483 }
 484
 485 /* Default implementation of LANG_HOOKS_TYPE_FOR_SIZE.
 486    Return an integer type with PRECISION bits of precision,
 487    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
 488
 489 tree
 490 lhd_type_for_size (unsigned precision, int unsignedp)
 491 {
 492   int i;
 493
 494   if (precision == TYPE_PRECISION (integer_type_node))
 495     return unsignedp ? unsigned_type_node : integer_type_node;
 496
 497   if (precision == TYPE_PRECISION (signed_char_type_node))
 498     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
 499
 500   if (precision == TYPE_PRECISION (short_integer_type_node))
 501     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
 502
 503   if (precision == TYPE_PRECISION (long_integer_type_node))
 504     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
 505
 506   if (precision == TYPE_PRECISION (long_long_integer_type_node))
 507     return unsignedp
 508            ? long_long_unsigned_type_node
 509            : long_long_integer_type_node;
 510
 511   for (i = 0; i < NUM_INT_N_ENTS; i ++)
 512     if (int_n_enabled_p[i]
 513         && precision == int_n_data[i].bitsize)
 514       return (unsignedp ? int_n_trees[i].unsigned_type
 515               : int_n_trees[i].signed_type);
 516
 517   if (precision <= TYPE_PRECISION (intQI_type_node))
 518     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
 519
 520   if (precision <= TYPE_PRECISION (intHI_type_node))
 521     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
 522
 523   if (precision <= TYPE_PRECISION (intSI_type_node))
 524     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
 525
 526   if (precision <= TYPE_PRECISION (intDI_type_node))
 527     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
 528
 529   if (precision <= TYPE_PRECISION (intTI_type_node))
 530     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
 531
 532   return NULL_TREE;
 533 }
 534
 535 HOST_WIDE_INT
 536 lhd_to_target_charset (HOST_WIDE_INT c)
 537 {
 538   return c;
 539 }
 540
 541 tree
 542 lhd_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED, bool *se ATTRIBUTE_UNUSED)
 543 {
 544   return expr;
 545 }
 546
 547 /* Return sharing kind if OpenMP sharing attribute of DECL is
 548    predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 549
 550 enum omp_clause_default_kind
 551 lhd_omp_predetermined_sharing (tree decl ATTRIBUTE_UNUSED)
 552 {
 553   if (DECL_ARTIFICIAL (decl))
 554     return OMP_CLAUSE_DEFAULT_SHARED;
 555   return OMP_CLAUSE_DEFAULT_UNSPECIFIED;
 556 }
 557
 558 /* Generate code to copy SRC to DST.  */
 559
 560 tree
 561 lhd_omp_assignment (tree clause ATTRIBUTE_UNUSED, tree dst, tree src)
 562 {
 563   return build2 (MODIFY_EXPR, TREE_TYPE (dst), dst, src);
 564 }
 565
 566 /* Finalize clause C.  */
 567
 568 void
 569 lhd_omp_finish_clause (tree, gimple_seq *)
 570 {
 571 }
 572
 573 /* Return true if DECL is a scalar variable (for the purpose of
 574    implicit firstprivatization).  */
 575
 576 bool
 577 lhd_omp_scalar_p (tree decl)
 578 {
 579   tree type = TREE_TYPE (decl);
 580   if (TREE_CODE (type) == REFERENCE_TYPE)
 581     type = TREE_TYPE (type);
 582   if (TREE_CODE (type) == COMPLEX_TYPE)
 583     type = TREE_TYPE (type);
 584   if (INTEGRAL_TYPE_P (type)
 585       || SCALAR_FLOAT_TYPE_P (type)
 586       || TREE_CODE (type) == POINTER_TYPE)
 587     return true;
 588   return false;
 589 }
 590
 591 /* Register language specific type size variables as potentially OpenMP
 592    firstprivate variables.  */
 593
 594 void
 595 lhd_omp_firstprivatize_type_sizes (struct gimplify_omp_ctx *c ATTRIBUTE_UNUSED,
 596                                    tree t ATTRIBUTE_UNUSED)
 597 {
 598 }
 599
 600 /* Return true if TYPE is an OpenMP mappable type.  */
 601
 602 bool
 603 lhd_omp_mappable_type (tree type)
 604 {
 605   /* Mappable type has to be complete.  */
 606   if (type == error_mark_node || !COMPLETE_TYPE_P (type))
 607     return false;
 608   return true;
 609 }
 610
 611 /* Common function for add_builtin_function and
 612    add_builtin_function_ext_scope.  */
 613 static tree
 614 add_builtin_function_common (const char *name,
 615                              tree type,
 616                              int function_code,
 617                              enum built_in_class cl,
 618                              const char *library_name,
 619                              tree attrs,
 620                              tree (*hook) (tree))
 621 {
 622   tree   id = get_identifier (name);
 623   tree decl = build_decl (BUILTINS_LOCATION, FUNCTION_DECL, id, type);
 624
 625   TREE_PUBLIC (decl)         = 1;
 626   DECL_EXTERNAL (decl)       = 1;
 627   DECL_BUILT_IN_CLASS (decl) = cl;
 628
 629   DECL_FUNCTION_CODE (decl)  = (enum built_in_function) function_code;
 630
 631   /* DECL_FUNCTION_CODE is a bitfield; verify that the value fits.  */
 632   gcc_assert (DECL_FUNCTION_CODE (decl) == function_code);
 633
 634   if (library_name)
 635     {
 636       tree libname = get_identifier (library_name);
 637
 638       libname = targetm.mangle_decl_assembler_name (decl, libname);
 639       SET_DECL_ASSEMBLER_NAME (decl, libname);
 640     }
 641
 642   /* Possibly apply some default attributes to this built-in function.  */
 643   if (attrs)
 644     decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
 645   else
 646     decl_attributes (&decl, NULL_TREE, 0);
 647
 648   return hook (decl);
 649
 650 }
 651
 652 /* Create a builtin function.  */
 653
 654 tree
 655 add_builtin_function (const char *name,
 656                       tree type,
 657                       int function_code,
 658                       enum built_in_class cl,
 659                       const char *library_name,
 660                       tree attrs)
 661 {
 662   return add_builtin_function_common (name, type, function_code, cl,
 663                                       library_name, attrs,
 664                                       lang_hooks.builtin_function);
 665 }
 666
 667 /* Like add_builtin_function, but make sure the scope is the external scope.
 668    This is used to delay putting in back end builtin functions until the ISA
 669    that defines the builtin is declared via function specific target options,
 670    which can save memory for machines like the x86_64 that have multiple ISAs.
 671    If this points to the same function as builtin_function, the backend must
 672    add all of the builtins at program initialization time.  */
 673
 674 tree
 675 add_builtin_function_ext_scope (const char *name,
 676                                 tree type,
 677                                 int function_code,
 678                                 enum built_in_class cl,
 679                                 const char *library_name,
 680                                 tree attrs)
 681 {
 682   return add_builtin_function_common (name, type, function_code, cl,
 683                                       library_name, attrs,
 684                                       lang_hooks.builtin_function_ext_scope);
 685 }
 686
 687 tree
 688 lhd_builtin_function (tree decl)
 689 {
 690   lang_hooks.decls.pushdecl (decl);
 691   return decl;
 692 }
 693
 694 /* Create a builtin type.  */
 695
 696 tree
 697 add_builtin_type (const char *name, tree type)
 698 {
 699   tree   id = get_identifier (name);
 700   tree decl = build_decl (BUILTINS_LOCATION, TYPE_DECL, id, type);
 701   return lang_hooks.decls.pushdecl (decl);
 702 }
 703
 704 /* LTO hooks.  */
 705
 706 /* Used to save and restore any previously active section.  */
 707 static section *saved_section;
 708
 709
 710 /* Begin a new LTO output section named NAME.  This default implementation
 711    saves the old section and emits assembly code to switch to the new
 712    section.  */
 713
 714 void
 715 lhd_begin_section (const char *name)
 716 {
 717   section *section;
 718
 719   /* Save the old section so we can restore it in lto_end_asm_section.  */
 720   gcc_assert (!saved_section);
 721   saved_section = in_section;
 722   if (!saved_section)
 723     saved_section = text_section;
 724
 725   /* Create a new section and switch to it.  */
 726   section = get_section (name, SECTION_DEBUG | SECTION_EXCLUDE, NULL);
 727   switch_to_section (section);
 728 }
 729
 730
 731 /* Write DATA of length LEN to the current LTO output section.  This default
 732    implementation just calls assemble_string.  */
 733
 734 void
 735 lhd_append_data (const void *data, size_t len, void *)
 736 {
 737   if (data)
 738     {
 739       timevar_push (TV_IPA_LTO_OUTPUT);
 740       assemble_string ((const char *)data, len);
 741       timevar_pop (TV_IPA_LTO_OUTPUT);
 742     }
 743 }
 744
 745
 746 /* Finish the current LTO output section.  This default implementation emits
 747    assembly code to switch to any section previously saved by
 748    lhd_begin_section.  */
 749
 750 void
 751 lhd_end_section (void)
 752 {
 753   if (saved_section)
 754     {
 755       switch_to_section (saved_section);
 756       saved_section = NULL;
 757     }
 758 }
 759
 760 /* Default implementation of enum_underlying_base_type using type_for_size.  */
 761
 762 tree
 763 lhd_enum_underlying_base_type (const_tree enum_type)
 764 {
 765   return lang_hooks.types.type_for_size (TYPE_PRECISION (enum_type),
 766                                          TYPE_UNSIGNED (enum_type));
 767 }
 768
 769 /* Default implementation of LANG_HOOKS_GET_SUBSTRING_LOCATION.  */
 770
 771 const char *
 772 lhd_get_substring_location (const substring_loc &, location_t *)
 773 {
 774   return "unimplemented";
 775 }
 776
 777 /* Default implementation of LANG_HOOKS_DECL_DWARF_ATTRIBUTE.  Don't add
 778    any attributes.  */
 779
 780 int
 781 lhd_decl_dwarf_attribute (const_tree, int)
 782 {
 783   return -1;
 784 }
 785
 786 /* Default implementation of LANG_HOOKS_TYPE_DWARF_ATTRIBUTE.  Don't add
 787    any attributes.  */
 788
 789 int
 790 lhd_type_dwarf_attribute (const_tree, int)
 791 {
 792   return -1;
 793 }
 794
 795 /* Default implementation of LANG_HOOKS_UNIT_SIZE_WITHOUT_REUSABLE_PADDING.
 796    Just return TYPE_SIZE_UNIT unadjusted.  */
 797
 798 tree
 799 lhd_unit_size_without_reusable_padding (tree t)
 800 {
 801   return TYPE_SIZE_UNIT (t);
 802 }
 803
 804 /* Returns true if the current lang_hooks represents the GNU C frontend.  */
 805
 806 bool
 807 lang_GNU_C (void)
 808 {
 809   return (strncmp (lang_hooks.name, "GNU C", 5) == 0
 810           && (lang_hooks.name[5] == '\0' || ISDIGIT (lang_hooks.name[5])));
 811 }
 812
 813 /* Returns true if the current lang_hooks represents the GNU C++ frontend.  */
 814
 815 bool
 816 lang_GNU_CXX (void)
 817 {
 818   return strncmp (lang_hooks.name, "GNU C++", 7) == 0;
 819 }
 820
 821 /* Returns true if the current lang_hooks represents the GNU Fortran frontend.  */
 822
 823 bool
 824 lang_GNU_Fortran (void)
 825 {
 826   return strncmp (lang_hooks.name, "GNU Fortran", 11) == 0;
 827 }
 828
 829 /* Returns true if the current lang_hooks represents the GNU Objective-C
 830    frontend.  */
 831
 832 bool
 833 lang_GNU_OBJC (void)
 834 {
 835   return strncmp (lang_hooks.name, "GNU Objective-C", 15) == 0;
 836 }