gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright (C) 2001-2020 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 3, or (at your option)
   9 any later version.
  10
  11 GCC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef GCC_LANG_HOOKS_H
  21 #define GCC_LANG_HOOKS_H
  22
  23 /* FIXME: This file should be #include-d after tree.h (for enum tree_code).  */
  24
  25 struct diagnostic_info;
  26
  27 struct gimplify_omp_ctx;
  28
  29 struct array_descr_info;
  30
  31 /* A print hook for print_tree ().  */
  32 typedef void (*lang_print_tree_hook) (FILE *, tree, int indent);
  33
  34 enum classify_record
  35   { RECORD_IS_STRUCT, RECORD_IS_CLASS, RECORD_IS_INTERFACE };
  36
  37 class substring_loc;
  38
  39 /* The following hooks are documented in langhooks.c.  Must not be
  40    NULL.  */
  41
  42 struct lang_hooks_for_tree_inlining
  43 {
  44   bool (*var_mod_type_p) (tree, tree);
  45 };
  46
  47 /* The following hooks are used by tree-dump.c.  */
  48
  49 struct lang_hooks_for_tree_dump
  50 {
  51   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  52      does not want the usual dumping of the second argument.  */
  53   bool (*dump_tree) (void *, tree);
  54
  55   /* Determine type qualifiers in a language-specific way.  */
  56   int (*type_quals) (const_tree);
  57 };
  58
  59 /* Hooks related to types.  */
  60
  61 struct lang_hooks_for_types
  62 {
  63   /* Return a new type (with the indicated CODE), doing whatever
  64      language-specific processing is required.  */
  65   tree (*make_type) (enum tree_code);
  66
  67   /* Make an enum type with the given name and values, associating
  68      them all with the given source location.  */
  69   tree (*simulate_enum_decl) (location_t, const char *, vec<string_int_pair>);
  70
  71   /* Return what kind of RECORD_TYPE this is, mainly for purposes of
  72      debug information.  If not defined, record types are assumed to
  73      be structures.  */
  74   enum classify_record (*classify_record) (tree);
  75
  76   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  77      mode.  */
  78   tree (*type_for_mode) (machine_mode, int);
  79
  80   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
  81      integer type with at least that precision.  */
  82   tree (*type_for_size) (unsigned, int);
  83
  84   /* True if the type is an instantiation of a generic type,
  85      e.g. C++ template implicit specializations.  */
  86   bool (*generic_p) (const_tree);
  87
  88   /* Returns the TREE_VEC of elements of a given generic argument pack.  */
  89   tree (*get_argument_pack_elems) (const_tree);
  90
  91   /* Given a type, apply default promotions to unnamed function
  92      arguments and return the new type.  Return the same type if no
  93      change.  Required by any language that supports variadic
  94      arguments.  The default hook dies.  */
  95   tree (*type_promotes_to) (tree);
  96
  97   /* Register TYPE as a builtin type with the indicated NAME.  The
  98      TYPE is placed in the outermost lexical scope.  The semantics
  99      should be analogous to:
 100
 101        typedef TYPE NAME;
 102
 103      in C.  The default hook ignores the declaration.  */
 104   void (*register_builtin_type) (tree, const char *);
 105
 106   /* This routine is called in tree.c to print an error message for
 107      invalid use of an incomplete type.  VALUE is the expression that
 108      was used (or 0 if that isn't known) and TYPE is the type that was
 109      invalid.  LOC is the location of the use.  */
 110   void (*incomplete_type_error) (location_t loc, const_tree value,
 111                                  const_tree type);
 112
 113   /* Called from assign_temp to return the maximum size, if there is one,
 114      for a type.  */
 115   tree (*max_size) (const_tree);
 116
 117   /* Register language specific type size variables as potentially OpenMP
 118      firstprivate variables.  */
 119   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 120
 121   /* Return true if TYPE is a mappable type.  */
 122   bool (*omp_mappable_type) (tree type);
 123
 124   /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
 125      Called only after doing all language independent checks.
 126      At present, this function is only called when both TYPE1 and TYPE2 are
 127      FUNCTION_TYPE or METHOD_TYPE.  */
 128   bool (*type_hash_eq) (const_tree, const_tree);
 129
 130   /* If non-NULL, return TYPE1 with any language-specific modifiers copied from
 131      TYPE2.  */
 132   tree (*copy_lang_qualifiers) (const_tree, const_tree);
 133
 134   /* Return TRUE if TYPE uses a hidden descriptor and fills in information
 135      for the debugger about the array bounds, strides, etc.  */
 136   bool (*get_array_descr_info) (const_tree, struct array_descr_info *);
 137
 138   /* Fill in information for the debugger about the bounds of TYPE.  */
 139   void (*get_subrange_bounds) (const_tree, tree *, tree *);
 140
 141   /* Called on INTEGER_TYPEs.  Return NULL_TREE for non-biased types.  For
 142      biased types, return as an INTEGER_CST node the value that is represented
 143      by a physical zero.  */
 144   tree (*get_type_bias) (const_tree);
 145
 146   /* A type descriptive of TYPE's complex layout generated to help the
 147      debugger to decode variable-length or self-referential constructs.
 148      This is only used for the AT_GNAT_descriptive_type DWARF attribute.  */
 149   tree (*descriptive_type) (const_tree);
 150
 151   /* If we requested a pointer to a vector, build up the pointers that
 152      we stripped off while looking for the inner type.  Similarly for
 153      return values from functions.  The argument TYPE is the top of the
 154      chain, and BOTTOM is the new type which we will point to.  */
 155   tree (*reconstruct_complex_type) (tree, tree);
 156
 157   /* Returns the tree that represents the underlying data type used to
 158      implement the enumeration.  The default implementation will just use
 159      type_for_size.  Used in dwarf2out.c to add a DW_AT_type base type
 160      reference to a DW_TAG_enumeration.  */
 161   tree (*enum_underlying_base_type) (const_tree);
 162
 163   /* Return a type to use in the debug info instead of TYPE, or NULL_TREE to
 164      keep TYPE.  This is useful to keep a single "source type" when the
 165      middle-end uses specialized types, for instance constrained discriminated
 166      types in Ada.  */
 167   tree (*get_debug_type) (const_tree);
 168
 169   /* Return TRUE if TYPE implements a fixed point type and fills in information
 170      for the debugger about scale factor, etc.  */
 171   bool (*get_fixed_point_type_info) (const_tree,
 172                                      struct fixed_point_type_info *);
 173
 174   /* Returns -1 if dwarf ATTR shouldn't be added for TYPE, or the attribute
 175      value otherwise.  */
 176   int (*type_dwarf_attribute) (const_tree, int);
 177
 178   /* Returns a tree for the unit size of T excluding tail padding that
 179      might be used by objects inheriting from T.  */
 180   tree (*unit_size_without_reusable_padding) (tree);
 181 };
 182
 183 /* Language hooks related to decls and the symbol table.  */
 184
 185 struct lang_hooks_for_decls
 186 {
 187   /* Return true if we are in the global binding level.  This hook is really
 188      needed only if the language supports variable-sized types at the global
 189      level, i.e. declared outside subprograms.  */
 190   bool (*global_bindings_p) (void);
 191
 192   /* Function to add a decl to the current scope level.  Takes one
 193      argument, a decl to add.  Returns that decl, or, if the same
 194      symbol is already declared, may return a different decl for that
 195      name.  */
 196   tree (*pushdecl) (tree);
 197
 198   /* Returns the chain of decls so far in the current scope level.  */
 199   tree (*getdecls) (void);
 200
 201   /* Returns -1 if dwarf ATTR shouldn't be added for DECL, or the attribute
 202      value otherwise.  */
 203   int (*decl_dwarf_attribute) (const_tree, int);
 204
 205   /* Returns True if the parameter is a generic parameter decl
 206      of a generic type, e.g a template template parameter for the C++ FE.  */
 207   bool (*generic_generic_parameter_decl_p) (const_tree);
 208
 209   /* Determine if a function parameter got expanded from a
 210      function parameter pack.  */
 211   bool (*function_parm_expanded_from_pack_p) (tree, tree);
 212
 213   /* Returns the generic declaration of a generic function instantiations.  */
 214   tree (*get_generic_function_decl) (const_tree);
 215
 216   /* Returns true when we should warn for an unused global DECL.
 217      We will already have checked that it has static binding.  */
 218   bool (*warn_unused_global) (const_tree);
 219
 220   /* Perform any post compilation-proper parser cleanups and
 221      processing.  This is currently only needed for the C++ parser,
 222      which hopefully can be cleaned up so this hook is no longer
 223      necessary.  */
 224   void (*post_compilation_parsing_cleanups) (void);
 225
 226   /* True if this decl may be called via a sibcall.  */
 227   bool (*ok_for_sibcall) (const_tree);
 228
 229   /* Return a tree for the actual data of an array descriptor - or NULL_TREE
 230      if original tree is not an array descriptor.  If the second argument
 231      is true, only the TREE_TYPE is returned without generating a new tree.  */
 232   tree (*omp_array_data) (tree, bool);
 233
 234   /* True if OpenMP should regard this DECL as being a scalar which has Fortran's
 235      allocatable or pointer attribute.  */
 236   bool (*omp_is_allocatable_or_ptr) (const_tree);
 237
 238   /* Check whether this DECL belongs to a Fortran optional argument.
 239      With 'for_present_check' set to false, decls which are optional parameters
 240      themselve are returned as tree - or a NULL_TREE otherwise. Those decls are
 241      always pointers.  With 'for_present_check' set to true, the decl for
 242      checking whether an argument is present is returned; for arguments with
 243      value attribute this is the hidden argument and of BOOLEAN_TYPE.  If the
 244      decl is unrelated to optional arguments, NULL_TREE is returned.  */
 245   tree (*omp_check_optional_argument) (tree, bool);
 246
 247   /* True if OpenMP should privatize what this DECL points to rather
 248      than the DECL itself.  */
 249   bool (*omp_privatize_by_reference) (const_tree);
 250
 251   /* Return sharing kind if OpenMP sharing attribute of DECL is
 252      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 253   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 254
 255   /* Return decl that should be reported for DEFAULT(NONE) failure
 256      diagnostics.  Usually the DECL passed in.  */
 257   tree (*omp_report_decl) (tree);
 258
 259   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 260      disregarded in OpenMP construct, because it is going to be
 261      remapped during OpenMP lowering.  SHARED is true if DECL
 262      is going to be shared, false if it is going to be privatized.  */
 263   bool (*omp_disregard_value_expr) (tree, bool);
 264
 265   /* Return true if DECL that is shared iff SHARED is true should
 266      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 267   bool (*omp_private_debug_clause) (tree, bool);
 268
 269   /* Return true if DECL in private clause needs
 270      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 271   bool (*omp_private_outer_ref) (tree);
 272
 273   /* Build and return code for a default constructor for DECL in
 274      response to CLAUSE.  OUTER is corresponding outer region's
 275      variable if needed.  Return NULL if nothing to be done.  */
 276   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 277
 278   /* Build and return code for a copy constructor from SRC to DST.  */
 279   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 280
 281   /* Similarly, except use an assignment operator instead.  */
 282   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 283
 284   /* Build and return code for a constructor of DST that sets it to
 285      SRC + ADD.  */
 286   tree (*omp_clause_linear_ctor) (tree clause, tree dst, tree src, tree add);
 287
 288   /* Build and return code destructing DECL.  Return NULL if nothing
 289      to be done.  */
 290   tree (*omp_clause_dtor) (tree clause, tree decl);
 291
 292   /* Do language specific checking on an implicitly determined clause.  */
 293   void (*omp_finish_clause) (tree clause, gimple_seq *pre_p);
 294
 295   /* Return true if DECL is a scalar variable (for the purpose of
 296      implicit firstprivatization).  */
 297   bool (*omp_scalar_p) (tree decl);
 298 };
 299
 300 /* Language hooks related to LTO serialization.  */
 301
 302 struct lang_hooks_for_lto
 303 {
 304   /* Begin a new LTO section named NAME.  */
 305   void (*begin_section) (const char *name);
 306
 307   /* Write DATA of length LEN to the currently open LTO section.  BLOCK is a
 308      pointer to the dynamically allocated memory containing DATA.  The
 309      append_data function is responsible for freeing it when it is no longer
 310      needed.  */
 311   void (*append_data) (const void *data, size_t len, void *block);
 312
 313   /* End the previously begun LTO section.  */
 314   void (*end_section) (void);
 315 };
 316
 317 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 318
 319 struct lang_hooks
 320 {
 321   /* String identifying the front end and optionally language standard
 322      version, e.g. "GNU C++98".  */
 323   const char *name;
 324
 325   /* sizeof (struct lang_identifier), so make_node () creates
 326      identifier nodes long enough for the language-specific slots.  */
 327   size_t identifier_size;
 328
 329   /* Remove any parts of the tree that are used only by the FE. */
 330   void (*free_lang_data) (tree);
 331
 332   /* Determines the size of any language-specific tcc_constant,
 333      tcc_exceptional or tcc_type nodes.  Since it is called from
 334      make_node, the only information available is the tree code.
 335      Expected to die on unrecognized codes.  */
 336   size_t (*tree_size) (enum tree_code);
 337
 338   /* Return the language mask used for converting argv into a sequence
 339      of options.  */
 340   unsigned int (*option_lang_mask) (void);
 341
 342   /* Initialize variables in an options structure.  */
 343   void (*init_options_struct) (struct gcc_options *opts);
 344
 345   /* After the initialize_diagnostics hook is called, do any simple
 346      initialization needed before any calls to handle_option, other
 347      than that done by the init_options_struct hook.  */
 348   void (*init_options) (unsigned int decoded_options_count,
 349                         struct cl_decoded_option *decoded_options);
 350
 351   /* Callback used to perform language-specific initialization for the
 352      global diagnostic context structure.  */
 353   void (*initialize_diagnostics) (diagnostic_context *);
 354
 355   /* Register language-specific dumps.  */
 356   void (*register_dumps) (gcc::dump_manager *);
 357
 358   /* Return true if a warning should be given about option OPTION,
 359      which is for the wrong language, false if it should be quietly
 360      ignored.  */
 361   bool (*complain_wrong_lang_p) (const struct cl_option *option);
 362
 363   /* Handle the switch CODE, which has real type enum opt_code from
 364      options.h.  If the switch takes an argument, it is passed in ARG
 365      which points to permanent storage.  The handler is responsible for
 366      checking whether ARG is NULL, which indicates that no argument
 367      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 368      for the positive and negative forms respectively.  HANDLERS should
 369      be passed to any recursive handle_option calls.  LOC is the
 370      location of the option.
 371
 372      Return true if the switch is valid, false if invalid.  */
 373   bool (*handle_option) (size_t code, const char *arg, HOST_WIDE_INT value,
 374                          int kind, location_t loc,
 375                          const struct cl_option_handlers *handlers);
 376
 377   /* Called when all command line options have been parsed to allow
 378      further processing and initialization
 379
 380      Should return true to indicate that a compiler back-end is
 381      not required, such as with the -E option.
 382
 383      If errorcount is nonzero after this call the compiler exits
 384      immediately and the finish hook is not called.  */
 385   bool (*post_options) (const char **);
 386
 387   /* Called after post_options to initialize the front end.  Return
 388      false to indicate that no further compilation be performed, in
 389      which case the finish hook is called immediately.  */
 390   bool (*init) (void);
 391
 392   /* Called at the end of compilation, as a finalizer.  */
 393   void (*finish) (void);
 394
 395   /* Parses the entire file.  */
 396   void (*parse_file) (void);
 397
 398   /* Determines if it's ok for a function to have no noreturn attribute.  */
 399   bool (*missing_noreturn_ok_p) (tree);
 400
 401   /* Called to obtain the alias set to be used for an expression or type.
 402      Returns -1 if the language does nothing special for it.  */
 403   alias_set_type (*get_alias_set) (tree);
 404
 405   /* Function to finish handling an incomplete decl at the end of
 406      compilation.  Default hook is does nothing.  */
 407   void (*finish_incomplete_decl) (tree);
 408
 409   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 410      DECL_NODE with a newly GC-allocated copy.  */
 411   void (*dup_lang_specific_decl) (tree);
 412
 413   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 414      thing that the assembler should talk about, set
 415      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 416      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 417      assembler does not talk about it.  */
 418   void (*set_decl_assembler_name) (tree);
 419
 420   /* Overwrite the DECL_ASSEMBLER_NAME for a node.  The name is being
 421      changed (including to or from NULL_TREE).  */
 422   void (*overwrite_decl_assembler_name) (tree, tree);
 423
 424   /* The front end can add its own statistics to -fmem-report with
 425      this hook.  It should output to stderr.  */
 426   void (*print_statistics) (void);
 427
 428   /* Called by print_tree when there is a tree of class tcc_exceptional
 429      that it doesn't know how to display.  */
 430   lang_print_tree_hook print_xnode;
 431
 432   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 433      and IDENTIFIER_NODE nodes.  */
 434   lang_print_tree_hook print_decl;
 435   lang_print_tree_hook print_type;
 436   lang_print_tree_hook print_identifier;
 437
 438   /* Computes the name to use to print a declaration.  DECL is the
 439      non-NULL declaration in question.  VERBOSITY determines what
 440      information will be printed: 0: DECL_NAME, demangled as
 441      necessary.  1: and scope information.  2: and any other
 442      information that might be interesting, such as function parameter
 443      types in C++.  The name is in the internal character set and
 444      needs to be converted to the locale character set of diagnostics,
 445      or to the execution character set for strings such as
 446      __PRETTY_FUNCTION__.  */
 447   const char *(*decl_printable_name) (tree decl, int verbosity);
 448
 449   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 450      information will be printed: 0: DECL_NAME, demangled as
 451      necessary.  1: and scope information.  */
 452   const char *(*dwarf_name) (tree, int verbosity);
 453
 454   /* This compares two types for equivalence ("compatible" in C-based languages).
 455      This routine should only return 1 if it is sure.  It should not be used
 456      in contexts where erroneously returning 0 causes problems.  */
 457   int (*types_compatible_p) (tree x, tree y);
 458
 459   /* Called by report_error_function to print out function name.  */
 460   void (*print_error_function) (diagnostic_context *, const char *,
 461                                 struct diagnostic_info *);
 462
 463   /* Convert a character from the host's to the target's character
 464      set.  The character should be in what C calls the "basic source
 465      character set" (roughly, the set of characters defined by plain
 466      old ASCII).  The default is to return the character unchanged,
 467      which is correct in most circumstances.  Note that both argument
 468      and result should be sign-extended under -fsigned-char,
 469      zero-extended under -fno-signed-char.  */
 470   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 471
 472   /* Pointers to machine-independent attribute tables, for front ends
 473      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 474      table of attributes specific to the language, a table of
 475      attributes common to two or more languages (to allow easy
 476      sharing), and a table of attributes for checking formats.  */
 477   const struct attribute_spec *attribute_table;
 478   const struct attribute_spec *common_attribute_table;
 479   const struct attribute_spec *format_attribute_table;
 480
 481   struct lang_hooks_for_tree_inlining tree_inlining;
 482
 483   struct lang_hooks_for_tree_dump tree_dump;
 484
 485   struct lang_hooks_for_decls decls;
 486
 487   struct lang_hooks_for_types types;
 488
 489   struct lang_hooks_for_lto lto;
 490
 491   /* Returns a TREE_VEC of the generic parameters of an instantiation of
 492      a generic type or decl, e.g. C++ template instantiation.  If
 493      TREE_CHAIN of the return value is set, it is an INTEGER_CST
 494      indicating how many of the elements are non-default.  */
 495   tree (*get_innermost_generic_parms) (const_tree);
 496
 497   /* Returns the TREE_VEC of arguments of an instantiation
 498      of a generic type of decl, e.g. C++ template instantiation.  */
 499   tree (*get_innermost_generic_args) (const_tree);
 500
 501   /* Determine if a tree is a function parameter pack.  */
 502   bool (*function_parameter_pack_p) (const_tree);
 503
 504   /* Perform language-specific gimplification on the argument.  Returns an
 505      enum gimplify_status, though we can't see that type here.  */
 506   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 507
 508   /* Do language specific processing in the builtin function DECL  */
 509   tree (*builtin_function) (tree decl);
 510
 511   /* Like builtin_function, but make sure the scope is the external scope.
 512      This is used to delay putting in back end builtin functions until the ISA
 513      that defines the builtin is declared via function specific target options,
 514      which can save memory for machines like the x86_64 that have multiple
 515      ISAs.  If this points to the same function as builtin_function, the
 516      backend must add all of the builtins at program initialization time.  */
 517   tree (*builtin_function_ext_scope) (tree decl);
 518
 519   /* Do language-specific processing for target-specific built-in
 520      function DECL, so that it is defined in the global scope (only)
 521      and is available without needing to be explicitly declared.
 522
 523      This is intended for targets that want to inject declarations of
 524      built-in functions into the source language (such as in response
 525      to a pragma) rather than providing them in the source language itself.  */
 526   tree (*simulate_builtin_function_decl) (tree decl);
 527
 528   /* Used to set up the tree_contains_structure array for a frontend. */
 529   void (*init_ts) (void);
 530
 531   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 532      to a contained expression or DECL, possibly updating *TC or *SE
 533      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 534   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 535
 536   /* The EH personality function decl.  */
 537   tree (*eh_personality) (void);
 538
 539   /* Map a type to a runtime object to match type.  */
 540   tree (*eh_runtime_type) (tree);
 541
 542   /* If non-NULL, this is a function that returns a function decl to be
 543      executed if an unhandled exception is propagated out of a cleanup
 544      region.  For example, in C++, an exception thrown by a destructor
 545      during stack unwinding is required to result in a call to
 546      `std::terminate', so the C++ version of this function returns a
 547      FUNCTION_DECL for `std::terminate'.  */
 548   tree (*eh_protect_cleanup_actions) (void);
 549
 550   /* Return true if a stmt can fallthru.  Used by block_may_fallthru
 551      to possibly handle language trees.  */
 552   bool (*block_may_fallthru) (const_tree);
 553
 554   /* True if this language uses __cxa_end_cleanup when the ARM EABI
 555      is enabled.  */
 556   bool eh_use_cxa_end_cleanup;
 557
 558   /* True if this language requires deep unsharing of tree nodes prior to
 559      gimplification.  */
 560   bool deep_unsharing;
 561
 562   /* True if this language may use custom descriptors for nested functions
 563      instead of trampolines.  */
 564   bool custom_function_descriptors;
 565
 566   /* True if this language emits begin stmt notes.  */
 567   bool emits_begin_stmt;
 568
 569   /* Run all lang-specific selftests.  */
 570   void (*run_lang_selftests) (void);
 571
 572   /* Attempt to determine the source location of the substring.
 573      If successful, return NULL and write the source location to *OUT_LOC.
 574      Otherwise return an error message.  Error messages are intended
 575      for GCC developers (to help debugging) rather than for end-users.  */
 576   const char *(*get_substring_location) (const substring_loc &,
 577                                          location_t *out_loc);
 578
 579   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 580      and langhooks.c accordingly.  */
 581 };
 582
 583 /* Each front end provides its own.  */
 584 extern struct lang_hooks lang_hooks;
 585
 586 extern tree add_builtin_function (const char *name, tree type,
 587                                   int function_code, enum built_in_class cl,
 588                                   const char *library_name,
 589                                   tree attrs);
 590
 591 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 592                                             int function_code,
 593                                             enum built_in_class cl,
 594                                             const char *library_name,
 595                                             tree attrs);
 596 extern tree simulate_builtin_function_decl (location_t, const char *, tree,
 597                                             int, const char *, tree);
 598 extern tree add_builtin_type (const char *name, tree type);
 599
 600 /* Language helper functions.  */
 601
 602 extern bool lang_GNU_C (void);
 603 extern bool lang_GNU_CXX (void);
 604 extern bool lang_GNU_Fortran (void);
 605 extern bool lang_GNU_OBJC (void);
 606
 607 #endif /* GCC_LANG_HOOKS_H */