gcc/langhooks.c

   1 /* Default language-specific hooks.
   2    Copyright (C) 2001-2021 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 #include "stor-layout.h"
  39 #include "cgraph.h"
  40 #include "debug.h"
  41
  42 /* Do nothing; in many cases the default hook.  */
  43
  44 void
  45 lhd_do_nothing (void)
  46 {
  47 }
  48
  49 /* Do nothing (tree).  */
  50
  51 void
  52 lhd_do_nothing_t (tree ARG_UNUSED (t))
  53 {
  54 }
  55
  56 /* Pass through (tree).  */
  57 tree
  58 lhd_pass_through_t (tree t)
  59 {
  60   return t;
  61 }
  62
  63 /* Do nothing (int, int, int).  Return NULL_TREE.  */
  64
  65 tree
  66 lhd_do_nothing_iii_return_null_tree (int ARG_UNUSED (i),
  67                                      int ARG_UNUSED (j),
  68                                      int ARG_UNUSED (k))
  69 {
  70   return NULL_TREE;
  71 }
  72
  73 /* Do nothing (function).  */
  74
  75 void
  76 lhd_do_nothing_f (struct function * ARG_UNUSED (f))
  77 {
  78 }
  79
  80 /* Do nothing (return NULL_TREE).  */
  81
  82 tree
  83 lhd_return_null_tree (tree ARG_UNUSED (t))
  84 {
  85   return NULL_TREE;
  86 }
  87
  88 /* Do nothing (return NULL_TREE).  */
  89
  90 tree
  91 lhd_return_null_const_tree (const_tree ARG_UNUSED (t))
  92 {
  93   return NULL_TREE;
  94 }
  95
  96 /* The default post options hook.  */
  97
  98 bool
  99 lhd_post_options (const char ** ARG_UNUSED (pfilename))
 100 {
 101   /* Excess precision other than "fast" requires front-end
 102      support.  */
 103   flag_excess_precision = EXCESS_PRECISION_FAST;
 104   return false;
 105 }
 106
 107 /* Called from by print-tree.c.  */
 108
 109 void
 110 lhd_print_tree_nothing (FILE * ARG_UNUSED (file),
 111                         tree ARG_UNUSED (node),
 112                         int ARG_UNUSED (indent))
 113 {
 114 }
 115
 116 /* Called from check_global_declaration.  */
 117
 118 bool
 119 lhd_warn_unused_global_decl (const_tree decl)
 120 {
 121   /* This is what used to exist in check_global_declaration.  Probably
 122      not many of these actually apply to non-C languages.  */
 123
 124   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
 125     return false;
 126   if (VAR_P (decl) && TREE_READONLY (decl))
 127     return false;
 128   if (DECL_IN_SYSTEM_HEADER (decl))
 129     return false;
 130
 131   return true;
 132 }
 133
 134 /* Set the DECL_ASSEMBLER_NAME for DECL.  */
 135 void
 136 lhd_set_decl_assembler_name (tree decl)
 137 {
 138   tree id;
 139
 140   /* set_decl_assembler_name may be called on TYPE_DECL to record ODR
 141      name for C++ types.  By default types have no ODR names.  */
 142   if (TREE_CODE (decl) == TYPE_DECL)
 143     return;
 144
 145   /* The language-independent code should never use the
 146      DECL_ASSEMBLER_NAME for lots of DECLs.  Only FUNCTION_DECLs and
 147      VAR_DECLs for variables with static storage duration need a real
 148      DECL_ASSEMBLER_NAME.  */
 149   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
 150               || (VAR_P (decl)
 151                   && (TREE_STATIC (decl)
 152                       || DECL_EXTERNAL (decl)
 153                       || TREE_PUBLIC (decl))));
 154
 155   /* By default, assume the name to use in assembly code is the same
 156      as that used in the source language.  (That's correct for C, and
 157      GCC used to set DECL_ASSEMBLER_NAME to the same value as
 158      DECL_NAME in build_decl, so this choice provides backwards
 159      compatibility with existing front-ends.  This assumption is wrapped
 160      in a target hook, to allow for target-specific modification of the
 161      identifier.
 162
 163      Can't use just the variable's own name for a variable whose scope
 164      is less than the whole compilation.  Concatenate a distinguishing
 165      number.  */
 166
 167   if (TREE_PUBLIC (decl) || DECL_FILE_SCOPE_P (decl))
 168     id = targetm.mangle_decl_assembler_name (decl, DECL_NAME (decl));
 169   else
 170     {
 171       const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
 172       static unsigned long num;
 173       char *label;
 174
 175       ASM_FORMAT_PRIVATE_NAME (label, name, num++);
 176       id = get_identifier (label);
 177     }
 178
 179   SET_DECL_ASSEMBLER_NAME (decl, id);
 180 }
 181
 182 /* Forcibly overwrite the DECL_ASSEMBLER_NAME for DECL to NAME.  */
 183 void
 184 lhd_overwrite_decl_assembler_name (tree decl, tree name)
 185 {
 186   DECL_ASSEMBLER_NAME_RAW (decl) = name;
 187 }
 188
 189 /* Type promotion for variable arguments.  */
 190 tree
 191 lhd_type_promotes_to (tree ARG_UNUSED (type))
 192 {
 193   gcc_unreachable ();
 194 }
 195
 196 /* Registration of machine- or os-specific builtin types.  */
 197 void
 198 lhd_register_builtin_type (tree ARG_UNUSED (type),
 199                            const char * ARG_UNUSED (name))
 200 {
 201 }
 202
 203 /* Invalid use of an incomplete type.  */
 204 void
 205 lhd_incomplete_type_error (location_t ARG_UNUSED (loc),
 206                            const_tree ARG_UNUSED (value), const_tree type)
 207 {
 208   gcc_assert (TREE_CODE (type) == ERROR_MARK);
 209   return;
 210 }
 211
 212 /* Provide a default routine for alias sets that always returns -1.  This
 213    is used by languages that don't need to do anything special.  */
 214
 215 alias_set_type
 216 lhd_get_alias_set (tree ARG_UNUSED (t))
 217 {
 218   return -1;
 219 }
 220
 221 /* This is the default decl_printable_name function.  */
 222
 223 const char *
 224 lhd_decl_printable_name (tree decl, int ARG_UNUSED (verbosity))
 225 {
 226   gcc_assert (decl && DECL_NAME (decl));
 227   return IDENTIFIER_POINTER (DECL_NAME (decl));
 228 }
 229
 230 /* This is the default dwarf_name function.  */
 231
 232 const char *
 233 lhd_dwarf_name (tree t, int verbosity)
 234 {
 235   gcc_assert (DECL_P (t));
 236
 237   return lang_hooks.decl_printable_name (t, verbosity);
 238 }
 239
 240 /* This compares two types for equivalence ("compatible" in C-based languages).
 241    This routine should only return 1 if it is sure.  It should not be used
 242    in contexts where erroneously returning 0 causes problems.  */
 243
 244 int
 245 lhd_types_compatible_p (tree x, tree y)
 246 {
 247   return TYPE_MAIN_VARIANT (x) == TYPE_MAIN_VARIANT (y);
 248 }
 249
 250 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
 251    nodes.  Returns nonzero if it does not want the usual dumping of the
 252    second argument.  */
 253
 254 bool
 255 lhd_tree_dump_dump_tree (void *di ATTRIBUTE_UNUSED, tree t ATTRIBUTE_UNUSED)
 256 {
 257   return false;
 258 }
 259
 260 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
 261    language-specific way.  */
 262
 263 int
 264 lhd_tree_dump_type_quals (const_tree t)
 265 {
 266   return TYPE_QUALS (t);
 267 }
 268
 269 /* lang_hooks.gimplify_expr re-writes *EXPR_P into GIMPLE form.  */
 270
 271 int
 272 lhd_gimplify_expr (tree *expr_p ATTRIBUTE_UNUSED,
 273                    gimple_seq *pre_p ATTRIBUTE_UNUSED,
 274                    gimple_seq *post_p ATTRIBUTE_UNUSED)
 275 {
 276   return GS_UNHANDLED;
 277 }
 278
 279 /* lang_hooks.tree_size: Determine the size of a tree with code C,
 280    which is a language-specific tree code in category tcc_constant,
 281    tcc_exceptional or tcc_type.  The default expects never to be called.  */
 282 size_t
 283 lhd_tree_size (enum tree_code c ATTRIBUTE_UNUSED)
 284 {
 285   gcc_unreachable ();
 286 }
 287
 288 /* Return true if decl, which is a function decl, may be called by a
 289    sibcall.  */
 290
 291 bool
 292 lhd_decl_ok_for_sibcall (const_tree decl ATTRIBUTE_UNUSED)
 293 {
 294   return true;
 295 }
 296
 297 /* Generic global declaration processing.  This is meant to be called
 298    by the front-ends at the end of parsing.  C/C++ do their own thing,
 299    but other front-ends may call this.  */
 300
 301 void
 302 global_decl_processing (void)
 303 {
 304   tree globals, decl, *vec;
 305   int len, i;
 306
 307   timevar_stop (TV_PHASE_PARSING);
 308   timevar_start (TV_PHASE_DEFERRED);
 309   /* Really define vars that have had only a tentative definition.
 310      Really output inline functions that must actually be callable
 311      and have not been output so far.  */
 312
 313   globals = lang_hooks.decls.getdecls ();
 314   len = list_length (globals);
 315   vec = XNEWVEC (tree, len);
 316
 317   /* Process the decls in reverse order--earliest first.
 318      Put them into VEC from back to front, then take out from front.  */
 319
 320   for (i = 0, decl = globals; i < len; i++, decl = DECL_CHAIN (decl))
 321     vec[len - i - 1] = decl;
 322
 323   wrapup_global_declarations (vec, len);
 324   timevar_stop (TV_PHASE_DEFERRED);
 325
 326   timevar_start (TV_PHASE_PARSING);
 327   free (vec);
 328 }
 329
 330 /* Called to perform language-specific initialization of CTX.  */
 331 void
 332 lhd_initialize_diagnostics (diagnostic_context *ctx ATTRIBUTE_UNUSED)
 333 {
 334 }
 335
 336 /* Called to register dumps.  */
 337 void
 338 lhd_register_dumps (gcc::dump_manager *)
 339 {
 340 }
 341
 342 /* Called to perform language-specific options initialization.  */
 343 void
 344 lhd_init_options (unsigned int decoded_options_count ATTRIBUTE_UNUSED,
 345                   struct cl_decoded_option *decoded_options ATTRIBUTE_UNUSED)
 346 {
 347 }
 348
 349 /* By default, always complain about options for the wrong language.  */
 350 bool
 351 lhd_complain_wrong_lang_p (const struct cl_option *option ATTRIBUTE_UNUSED)
 352 {
 353   return true;
 354 }
 355
 356 /* By default, no language-specific options are valid.  */
 357 bool
 358 lhd_handle_option (size_t code ATTRIBUTE_UNUSED,
 359                    const char *arg ATTRIBUTE_UNUSED,
 360                    HOST_WIDE_INT value ATTRIBUTE_UNUSED,
 361                    int kind ATTRIBUTE_UNUSED,
 362                    location_t loc ATTRIBUTE_UNUSED,
 363                    const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
 364 {
 365   return false;
 366 }
 367
 368 /* The default function to print out name of current function that caused
 369    an error.  */
 370 void
 371 lhd_print_error_function (diagnostic_context *context, const char *file,
 372                           diagnostic_info *diagnostic)
 373 {
 374   if (diagnostic_last_function_changed (context, diagnostic))
 375     {
 376       char *old_prefix = pp_take_prefix (context->printer);
 377       tree abstract_origin = diagnostic_abstract_origin (diagnostic);
 378       char *new_prefix = (file && abstract_origin == NULL)
 379                          ? file_name_as_prefix (context, file) : NULL;
 380
 381       pp_set_prefix (context->printer, new_prefix);
 382
 383       if (current_function_decl == NULL)
 384         pp_printf (context->printer, _("At top level:"));
 385       else
 386         {
 387           tree fndecl, ao;
 388
 389           if (abstract_origin)
 390             {
 391               ao = BLOCK_ABSTRACT_ORIGIN (abstract_origin);
 392               gcc_assert (TREE_CODE (ao) == FUNCTION_DECL);
 393               fndecl = ao;
 394             }
 395           else
 396             fndecl = current_function_decl;
 397
 398           if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
 399             pp_printf
 400               (context->printer, _("In member function %qs"),
 401                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 402           else
 403             pp_printf
 404               (context->printer, _("In function %qs"),
 405                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 406
 407           while (abstract_origin)
 408             {
 409               location_t *locus;
 410               tree block = abstract_origin;
 411
 412               locus = &BLOCK_SOURCE_LOCATION (block);
 413               fndecl = NULL;
 414               block = BLOCK_SUPERCONTEXT (block);
 415               while (block && TREE_CODE (block) == BLOCK
 416                      && BLOCK_ABSTRACT_ORIGIN (block))
 417                 {
 418                   ao = BLOCK_ABSTRACT_ORIGIN (block);
 419                   if (TREE_CODE (ao) == FUNCTION_DECL)
 420                     {
 421                       fndecl = ao;
 422                       break;
 423                     }
 424                   else if (TREE_CODE (ao) != BLOCK)
 425                     break;
 426
 427                   block = BLOCK_SUPERCONTEXT (block);
 428                 }
 429               if (fndecl)
 430                 abstract_origin = block;
 431               else
 432                 {
 433                   while (block && TREE_CODE (block) == BLOCK)
 434                     block = BLOCK_SUPERCONTEXT (block);
 435
 436                   if (block && TREE_CODE (block) == FUNCTION_DECL)
 437                     fndecl = block;
 438                   abstract_origin = NULL;
 439                 }
 440               if (fndecl)
 441                 {
 442                   expanded_location s = expand_location (*locus);
 443                   pp_comma (context->printer);
 444                   pp_newline (context->printer);
 445                   if (s.file != NULL)
 446                     {
 447                       if (context->show_column)
 448                         pp_printf (context->printer,
 449                                    _("    inlined from %qs at %r%s:%d:%d%R"),
 450                                    identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
 451                                    "locus", s.file, s.line, s.column);
 452                       else
 453                         pp_printf (context->printer,
 454                                    _("    inlined from %qs at %r%s:%d%R"),
 455                                    identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
 456                                    "locus", s.file, s.line);
 457
 458                     }
 459                   else
 460                     pp_printf (context->printer, _("    inlined from %qs"),
 461                                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 462                 }
 463             }
 464           pp_colon (context->printer);
 465         }
 466
 467       diagnostic_set_last_function (context, diagnostic);
 468       pp_newline_and_flush (context->printer);
 469       context->printer->prefix = old_prefix;
 470       free ((char*) new_prefix);
 471     }
 472 }
 473
 474 tree
 475 lhd_make_node (enum tree_code code)
 476 {
 477   return make_node (code);
 478 }
 479
 480 /* Default implementation of LANG_HOOKS_SIMULATE_ENUM_DECL.  Assume a
 481    simple int-based enumerator (which is all the hook can be used for
 482    at present) and push each decl individually without any decoration.
 483
 484    This definition is suitable for LTO and is generic enough that it
 485    might be reusable elsewhere.  */
 486 tree
 487 lhd_simulate_enum_decl (location_t loc, const char *name,
 488                         vec<string_int_pair> *values_ptr)
 489 {
 490   tree enumtype = lang_hooks.types.make_type (ENUMERAL_TYPE);
 491   tree enumdecl = build_decl (loc, TYPE_DECL, get_identifier (name), enumtype);
 492   TYPE_STUB_DECL (enumtype) = enumdecl;
 493
 494   tree value_chain = NULL_TREE;
 495   string_int_pair *value;
 496   vec<string_int_pair> values = *values_ptr;
 497   unsigned int i;
 498   FOR_EACH_VEC_ELT (values, i, value)
 499     {
 500       tree value_decl = build_decl (loc, CONST_DECL,
 501                                     get_identifier (value->first), enumtype);
 502       DECL_INITIAL (value_decl) = build_int_cst (integer_type_node,
 503                                                  value->second);
 504       lang_hooks.decls.pushdecl (value_decl);
 505       value_chain = tree_cons (value_decl, DECL_INITIAL (value_decl),
 506                                value_chain);
 507     }
 508
 509   TYPE_MIN_VALUE (enumtype) = TYPE_MIN_VALUE (integer_type_node);
 510   TYPE_MAX_VALUE (enumtype) = TYPE_MAX_VALUE (integer_type_node);
 511   SET_TYPE_ALIGN (enumtype, TYPE_ALIGN (integer_type_node));
 512   TYPE_PRECISION (enumtype) = TYPE_PRECISION (integer_type_node);
 513   layout_type (enumtype);
 514   lang_hooks.decls.pushdecl (enumdecl);
 515
 516   return enumtype;
 517 }
 518
 519 /* Default implementation of LANG_HOOKS_TYPE_FOR_SIZE.
 520    Return an integer type with PRECISION bits of precision,
 521    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
 522
 523 tree
 524 lhd_type_for_size (unsigned precision, int unsignedp)
 525 {
 526   int i;
 527
 528   if (precision == TYPE_PRECISION (integer_type_node))
 529     return unsignedp ? unsigned_type_node : integer_type_node;
 530
 531   if (precision == TYPE_PRECISION (signed_char_type_node))
 532     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
 533
 534   if (precision == TYPE_PRECISION (short_integer_type_node))
 535     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
 536
 537   if (precision == TYPE_PRECISION (long_integer_type_node))
 538     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
 539
 540   if (precision == TYPE_PRECISION (long_long_integer_type_node))
 541     return unsignedp
 542            ? long_long_unsigned_type_node
 543            : long_long_integer_type_node;
 544
 545   for (i = 0; i < NUM_INT_N_ENTS; i ++)
 546     if (int_n_enabled_p[i]
 547         && precision == int_n_data[i].bitsize)
 548       return (unsignedp ? int_n_trees[i].unsigned_type
 549               : int_n_trees[i].signed_type);
 550
 551   if (precision <= TYPE_PRECISION (intQI_type_node))
 552     return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
 553
 554   if (precision <= TYPE_PRECISION (intHI_type_node))
 555     return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
 556
 557   if (precision <= TYPE_PRECISION (intSI_type_node))
 558     return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
 559
 560   if (precision <= TYPE_PRECISION (intDI_type_node))
 561     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
 562
 563   if (precision <= TYPE_PRECISION (intTI_type_node))
 564     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
 565
 566   return NULL_TREE;
 567 }
 568
 569 HOST_WIDE_INT
 570 lhd_to_target_charset (HOST_WIDE_INT c)
 571 {
 572   return c;
 573 }
 574
 575 tree
 576 lhd_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED, bool *se ATTRIBUTE_UNUSED)
 577 {
 578   return expr;
 579 }
 580
 581 /* Return sharing kind if OpenMP sharing attribute of DECL is
 582    predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 583
 584 enum omp_clause_default_kind
 585 lhd_omp_predetermined_sharing (tree decl)
 586 {
 587   if (DECL_ARTIFICIAL (decl))
 588     return OMP_CLAUSE_DEFAULT_SHARED;
 589   return OMP_CLAUSE_DEFAULT_UNSPECIFIED;
 590 }
 591
 592 /* Return sharing kind if OpenMP mapping attribute of DECL is
 593    predetermined, OMP_CLAUSE_DEFAULTMAP_CATEGORY_UNSPECIFIED otherwise.  */
 594
 595 enum omp_clause_defaultmap_kind
 596 lhd_omp_predetermined_mapping (tree decl)
 597 {
 598   if (DECL_ARTIFICIAL (decl))
 599     return OMP_CLAUSE_DEFAULTMAP_TO;
 600   return OMP_CLAUSE_DEFAULTMAP_CATEGORY_UNSPECIFIED;
 601 }
 602
 603 /* Generate code to copy SRC to DST.  */
 604
 605 tree
 606 lhd_omp_assignment (tree clause ATTRIBUTE_UNUSED, tree dst, tree src)
 607 {
 608   return build2 (MODIFY_EXPR, TREE_TYPE (dst), dst, src);
 609 }
 610
 611 /* Finalize clause C.  */
 612
 613 void
 614 lhd_omp_finish_clause (tree, gimple_seq *, bool)
 615 {
 616 }
 617
 618 /* Return true if DECL is a scalar variable (for the purpose of
 619    implicit firstprivatization & mapping). Only if alloc_ptr_ok
 620    are allocatables and pointers accepted. */
 621
 622 bool
 623 lhd_omp_scalar_p (tree decl, bool ptr_ok)
 624 {
 625   tree type = TREE_TYPE (decl);
 626   if (TREE_CODE (type) == REFERENCE_TYPE)
 627     type = TREE_TYPE (type);
 628   if (TREE_CODE (type) == COMPLEX_TYPE)
 629     type = TREE_TYPE (type);
 630   if (INTEGRAL_TYPE_P (type)
 631       || SCALAR_FLOAT_TYPE_P (type)
 632       || (ptr_ok && TREE_CODE (type) == POINTER_TYPE))
 633     return true;
 634   return false;
 635 }
 636
 637 /* Return static initializer for DECL.  */
 638
 639 tree *
 640 lhd_omp_get_decl_init (tree decl)
 641 {
 642   return &DECL_INITIAL (decl);
 643 }
 644
 645 /* Free any extra memory used to hold initializer information for
 646    variable declarations.  */
 647
 648 void
 649 lhd_omp_finish_decl_inits (void)
 650 {
 651 }
 652
 653 /* Register language specific type size variables as potentially OpenMP
 654    firstprivate variables.  */
 655
 656 void
 657 lhd_omp_firstprivatize_type_sizes (struct gimplify_omp_ctx *c ATTRIBUTE_UNUSED,
 658                                    tree t ATTRIBUTE_UNUSED)
 659 {
 660 }
 661
 662 /* Return true if TYPE is an OpenMP mappable type.  */
 663
 664 bool
 665 lhd_omp_mappable_type (tree type)
 666 {
 667   /* Mappable type has to be complete.  */
 668   if (type == error_mark_node || !COMPLETE_TYPE_P (type))
 669     return false;
 670   return true;
 671 }
 672
 673 /* Common function for add_builtin_function, add_builtin_function_ext_scope
 674    and simulate_builtin_function_decl.  */
 675
 676 static tree
 677 build_builtin_function (location_t location, const char *name, tree type,
 678                         int function_code, enum built_in_class cl,
 679                         const char *library_name, tree attrs)
 680 {
 681   tree   id = get_identifier (name);
 682   tree decl = build_decl (location, FUNCTION_DECL, id, type);
 683
 684   TREE_PUBLIC (decl)         = 1;
 685   DECL_EXTERNAL (decl)       = 1;
 686
 687   set_decl_built_in_function (decl, cl, function_code);
 688
 689   if (library_name)
 690     {
 691       tree libname = get_identifier (library_name);
 692
 693       libname = targetm.mangle_decl_assembler_name (decl, libname);
 694       SET_DECL_ASSEMBLER_NAME (decl, libname);
 695     }
 696
 697   /* Possibly apply some default attributes to this built-in function.  */
 698   if (attrs)
 699     decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
 700   else
 701     decl_attributes (&decl, NULL_TREE, 0);
 702
 703   return decl;
 704 }
 705
 706 /* Create a builtin function.  */
 707
 708 tree
 709 add_builtin_function (const char *name,
 710                       tree type,
 711                       int function_code,
 712                       enum built_in_class cl,
 713                       const char *library_name,
 714                       tree attrs)
 715 {
 716   tree decl = build_builtin_function (BUILTINS_LOCATION, name, type,
 717                                       function_code, cl, library_name, attrs);
 718   return lang_hooks.builtin_function (decl);
 719 }
 720
 721 /* Like add_builtin_function, but make sure the scope is the external scope.
 722    This is used to delay putting in back end builtin functions until the ISA
 723    that defines the builtin is declared via function specific target options,
 724    which can save memory for machines like the x86_64 that have multiple ISAs.
 725    If this points to the same function as builtin_function, the backend must
 726    add all of the builtins at program initialization time.  */
 727
 728 tree
 729 add_builtin_function_ext_scope (const char *name,
 730                                 tree type,
 731                                 int function_code,
 732                                 enum built_in_class cl,
 733                                 const char *library_name,
 734                                 tree attrs)
 735 {
 736   tree decl = build_builtin_function (BUILTINS_LOCATION, name, type,
 737                                       function_code, cl, library_name, attrs);
 738   return lang_hooks.builtin_function_ext_scope (decl);
 739 }
 740
 741 /* Simulate a declaration of a target-specific built-in function at
 742    location LOCATION, as though it had been declared directly in the
 743    source language.  NAME is the name of the function, TYPE is its function
 744    type, FUNCTION_CODE is the target-specific function code, LIBRARY_NAME
 745    is the name of the underlying library function (NULL if none) and
 746    ATTRS is a list of function attributes.
 747
 748    Return the decl of the declared function.  */
 749
 750 tree
 751 simulate_builtin_function_decl (location_t location, const char *name,
 752                                 tree type, int function_code,
 753                                 const char *library_name, tree attrs)
 754 {
 755   tree decl = build_builtin_function (location, name, type,
 756                                       function_code, BUILT_IN_MD,
 757                                       library_name, attrs);
 758   tree new_decl = lang_hooks.simulate_builtin_function_decl (decl);
 759
 760   /* Give the front end a chance to create a new decl if necessary,
 761      but if the front end discards the decl in favour of a conflicting
 762      (erroneous) previous definition, return the decl that we tried but
 763      failed to add.  This allows the caller to process the returned decl
 764      normally, even though the source code won't be able to use it.  */
 765   if (TREE_CODE (new_decl) == FUNCTION_DECL
 766       && fndecl_built_in_p (new_decl, function_code, BUILT_IN_MD))
 767     return new_decl;
 768
 769   return decl;
 770 }
 771
 772 tree
 773 lhd_builtin_function (tree decl)
 774 {
 775   lang_hooks.decls.pushdecl (decl);
 776   return decl;
 777 }
 778
 779 /* Create a builtin type.  */
 780
 781 tree
 782 add_builtin_type (const char *name, tree type)
 783 {
 784   tree   id = get_identifier (name);
 785   tree decl = build_decl (BUILTINS_LOCATION, TYPE_DECL, id, type);
 786   return lang_hooks.decls.pushdecl (decl);
 787 }
 788
 789 /* LTO hooks.  */
 790
 791 /* Used to save and restore any previously active section.  */
 792 static section *saved_section;
 793
 794
 795 /* Begin a new LTO output section named NAME.  This default implementation
 796    saves the old section and emits assembly code to switch to the new
 797    section.  */
 798
 799 void
 800 lhd_begin_section (const char *name)
 801 {
 802   section *section;
 803
 804   /* Save the old section so we can restore it in lto_end_asm_section.  */
 805   gcc_assert (!saved_section);
 806   saved_section = in_section;
 807   if (!saved_section)
 808     saved_section = text_section;
 809
 810   /* Create a new section and switch to it.  */
 811   section = get_section (name, SECTION_DEBUG | SECTION_EXCLUDE, NULL, true);
 812   switch_to_section (section);
 813 }
 814
 815
 816 /* Write DATA of length LEN to the current LTO output section.  This default
 817    implementation just calls assemble_string.  */
 818
 819 void
 820 lhd_append_data (const void *data, size_t len, void *)
 821 {
 822   if (data)
 823     {
 824       timevar_push (TV_IPA_LTO_OUTPUT);
 825       assemble_string ((const char *)data, len);
 826       timevar_pop (TV_IPA_LTO_OUTPUT);
 827     }
 828 }
 829
 830
 831 /* Finish the current LTO output section.  This default implementation emits
 832    assembly code to switch to any section previously saved by
 833    lhd_begin_section.  */
 834
 835 void
 836 lhd_end_section (void)
 837 {
 838   if (saved_section)
 839     {
 840       switch_to_section (saved_section);
 841       saved_section = NULL;
 842     }
 843 }
 844
 845 /* Default implementation of enum_underlying_base_type using type_for_size.  */
 846
 847 tree
 848 lhd_enum_underlying_base_type (const_tree enum_type)
 849 {
 850   return lang_hooks.types.type_for_size (TYPE_PRECISION (enum_type),
 851                                          TYPE_UNSIGNED (enum_type));
 852 }
 853
 854 /* Default implementation of LANG_HOOKS_GET_SUBSTRING_LOCATION.  */
 855
 856 const char *
 857 lhd_get_substring_location (const substring_loc &, location_t *)
 858 {
 859   return "unimplemented";
 860 }
 861
 862 /* Default implementation of LANG_HOOKS_DECL_DWARF_ATTRIBUTE.  Don't add
 863    any attributes.  */
 864
 865 int
 866 lhd_decl_dwarf_attribute (const_tree, int)
 867 {
 868   return -1;
 869 }
 870
 871 /* Default implementation of LANG_HOOKS_TYPE_DWARF_ATTRIBUTE.  Don't add
 872    any attributes.  */
 873
 874 int
 875 lhd_type_dwarf_attribute (const_tree, int)
 876 {
 877   return -1;
 878 }
 879
 880 /* Default implementation of LANG_HOOKS_UNIT_SIZE_WITHOUT_REUSABLE_PADDING.
 881    Just return TYPE_SIZE_UNIT unadjusted.  */
 882
 883 tree
 884 lhd_unit_size_without_reusable_padding (tree t)
 885 {
 886   return TYPE_SIZE_UNIT (t);
 887 }
 888
 889 /* Default implementation for the finalize_early_debug hook.  */
 890
 891 void
 892 lhd_finalize_early_debug (void)
 893 {
 894   /* Emit early debug for reachable functions, and by consequence,
 895      locally scoped symbols.  */
 896   struct cgraph_node *cnode;
 897   FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (cnode)
 898     (*debug_hooks->early_global_decl) (cnode->decl);
 899 }
 900
 901 /* Returns true if the current lang_hooks represents the GNU C frontend.  */
 902
 903 bool
 904 lang_GNU_C (void)
 905 {
 906   return (startswith (lang_hooks.name, "GNU C")
 907           && (lang_hooks.name[5] == '\0' || ISDIGIT (lang_hooks.name[5])));
 908 }
 909
 910 /* Returns true if the current lang_hooks represents the GNU C++ frontend.  */
 911
 912 bool
 913 lang_GNU_CXX (void)
 914 {
 915   return startswith (lang_hooks.name, "GNU C++");
 916 }
 917
 918 /* Returns true if the current lang_hooks represents the GNU Fortran frontend.  */
 919
 920 bool
 921 lang_GNU_Fortran (void)
 922 {
 923   return startswith (lang_hooks.name, "GNU Fortran");
 924 }
 925
 926 /* Returns true if the current lang_hooks represents the GNU Objective-C
 927    frontend.  */
 928
 929 bool
 930 lang_GNU_OBJC (void)
 931 {
 932   return startswith (lang_hooks.name, "GNU Objective-C");
 933 }