gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright (C) 2001-2024 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.cc.  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.cc.  */
  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   /* Do the equivalent of:
  72
  73        typedef struct NAME { FIELDS; } NAME;
  74
  75      associating it with location LOC.  Return the associated RECORD_TYPE.
  76
  77      FIELDS is a list of FIELD_DECLs, in layout order.  */
  78   tree (*simulate_record_decl) (location_t loc, const char *name,
  79                                 array_slice<const tree> fields);
  80
  81   /* Return what kind of RECORD_TYPE this is, mainly for purposes of
  82      debug information.  If not defined, record types are assumed to
  83      be structures.  */
  84   enum classify_record (*classify_record) (tree);
  85
  86   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  87      mode.  */
  88   tree (*type_for_mode) (machine_mode, int);
  89
  90   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
  91      integer type with at least that precision.  */
  92   tree (*type_for_size) (unsigned, int);
  93
  94   /* True if the type is an instantiation of a generic type,
  95      e.g. C++ template implicit specializations.  */
  96   bool (*generic_p) (const_tree);
  97
  98   /* Returns the TREE_VEC of elements of a given generic argument pack.  */
  99   tree (*get_argument_pack_elems) (const_tree);
 100
 101   /* Given a type, apply default promotions to unnamed function
 102      arguments and return the new type.  Return the same type if no
 103      change.  Required by any language that supports variadic
 104      arguments.  The default hook dies.  */
 105   tree (*type_promotes_to) (tree);
 106
 107   /* Register TYPE as a builtin type with the indicated NAME.  The
 108      TYPE is placed in the outermost lexical scope.  The semantics
 109      should be analogous to:
 110
 111        typedef TYPE NAME;
 112
 113      in C.  The default hook ignores the declaration.  */
 114   void (*register_builtin_type) (tree, const char *);
 115
 116   /* This routine is called in tree.cc to print an error message for
 117      invalid use of an incomplete type.  VALUE is the expression that
 118      was used (or 0 if that isn't known) and TYPE is the type that was
 119      invalid.  LOC is the location of the use.  */
 120   void (*incomplete_type_error) (location_t loc, const_tree value,
 121                                  const_tree type);
 122
 123   /* Called from assign_temp to return the maximum size, if there is one,
 124      for a type.  */
 125   tree (*max_size) (const_tree);
 126
 127   /* Register language specific type size variables as potentially OpenMP
 128      firstprivate variables.  */
 129   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 130
 131   /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
 132      Called only after doing all language independent checks.
 133      At present, this function is only called when both TYPE1 and TYPE2 are
 134      FUNCTION_TYPE or METHOD_TYPE.  */
 135   bool (*type_hash_eq) (const_tree, const_tree);
 136
 137   /* If non-NULL, return TYPE1 with any language-specific modifiers copied from
 138      TYPE2.  */
 139   tree (*copy_lang_qualifiers) (const_tree, const_tree);
 140
 141   /* Return TRUE if TYPE uses a hidden descriptor and fills in information
 142      for the debugger about the array bounds, strides, etc.  */
 143   bool (*get_array_descr_info) (const_tree, struct array_descr_info *);
 144
 145   /* Fill in information for the debugger about the bounds of TYPE.  */
 146   void (*get_subrange_bounds) (const_tree, tree *, tree *);
 147
 148   /* Called on INTEGER_TYPEs.  Return NULL_TREE for non-biased types.  For
 149      biased types, return as an INTEGER_CST node the value that is represented
 150      by a physical zero.  */
 151   tree (*get_type_bias) (const_tree);
 152
 153   /* A type descriptive of TYPE's complex layout generated to help the
 154      debugger to decode variable-length or self-referential constructs.
 155      This is only used for the AT_GNAT_descriptive_type DWARF attribute.  */
 156   tree (*descriptive_type) (const_tree);
 157
 158   /* If we requested a pointer to a vector, build up the pointers that
 159      we stripped off while looking for the inner type.  Similarly for
 160      return values from functions.  The argument TYPE is the top of the
 161      chain, and BOTTOM is the new type which we will point to.  */
 162   tree (*reconstruct_complex_type) (tree, tree);
 163
 164   /* Returns the tree that represents the underlying data type used to
 165      implement the enumeration.  The default implementation will just use
 166      type_for_size.  Used in dwarf2out.cc to add a DW_AT_type base type
 167      reference to a DW_TAG_enumeration.  */
 168   tree (*enum_underlying_base_type) (const_tree);
 169
 170   /* Return a type to use in the debug info instead of TYPE, or NULL_TREE to
 171      keep TYPE.  This is useful to keep a single "source type" when the
 172      middle-end uses specialized types, for instance constrained discriminated
 173      types in Ada.  */
 174   tree (*get_debug_type) (const_tree);
 175
 176   /* Return TRUE if TYPE implements a fixed point type and fills in information
 177      for the debugger about scale factor, etc.  */
 178   bool (*get_fixed_point_type_info) (const_tree,
 179                                      struct fixed_point_type_info *);
 180
 181   /* Returns -1 if dwarf ATTR shouldn't be added for TYPE, or the attribute
 182      value otherwise.  */
 183   int (*type_dwarf_attribute) (const_tree, int);
 184
 185   /* Returns a tree for the unit size of T excluding tail padding that
 186      might be used by objects inheriting from T.  */
 187   tree (*unit_size_without_reusable_padding) (tree);
 188
 189   /* Returns type corresponding to FIELD's type when FIELD is a C++ base class
 190      i.e., type without virtual base classes or tail padding.  Returns
 191      NULL_TREE otherwise.  */
 192   tree (*classtype_as_base) (const_tree);
 193 };
 194
 195 /* Language hooks related to decls and the symbol table.  */
 196
 197 struct lang_hooks_for_decls
 198 {
 199   /* Return true if we are in the global binding level.  This hook is really
 200      needed only if the language supports variable-sized types at the global
 201      level, i.e. declared outside subprograms.  */
 202   bool (*global_bindings_p) (void);
 203
 204   /* Function to add a decl to the current scope level.  Takes one
 205      argument, a decl to add.  Returns that decl, or, if the same
 206      symbol is already declared, may return a different decl for that
 207      name.  */
 208   tree (*pushdecl) (tree);
 209
 210   /* Returns the chain of decls so far in the current scope level.  */
 211   tree (*getdecls) (void);
 212
 213   /* Returns -1 if dwarf ATTR shouldn't be added for DECL, or the attribute
 214      value otherwise.  */
 215   int (*decl_dwarf_attribute) (const_tree, int);
 216
 217   /* Returns True if the parameter is a generic parameter decl
 218      of a generic type, e.g a template template parameter for the C++ FE.  */
 219   bool (*generic_generic_parameter_decl_p) (const_tree);
 220
 221   /* Determine if a function parameter got expanded from a
 222      function parameter pack.  */
 223   bool (*function_parm_expanded_from_pack_p) (tree, tree);
 224
 225   /* Returns the generic declaration of a generic function instantiations.  */
 226   tree (*get_generic_function_decl) (const_tree);
 227
 228   /* Returns true when we should warn for an unused global DECL.
 229      We will already have checked that it has static binding.  */
 230   bool (*warn_unused_global) (const_tree);
 231
 232   /* Perform any post compilation-proper parser cleanups and
 233      processing.  This is currently only needed for the C++ parser,
 234      which hopefully can be cleaned up so this hook is no longer
 235      necessary.  */
 236   void (*post_compilation_parsing_cleanups) (void);
 237
 238   /* True if this decl may be called via a sibcall.  */
 239   bool (*ok_for_sibcall) (const_tree);
 240
 241   /* Return a tree for the actual data of an array descriptor - or NULL_TREE
 242      if original tree is not an array descriptor.  If the second argument
 243      is true, only the TREE_TYPE is returned without generating a new tree.  */
 244   tree (*omp_array_data) (tree, bool);
 245
 246   /* Return a tree for the actual data of an array descriptor - or NULL_TREE
 247      if original tree is not an array descriptor.  If the second argument
 248      is true, only the TREE_TYPE is returned without generating a new tree.  */
 249   tree (*omp_array_size) (tree, gimple_seq *pre_p);
 250
 251   /* True if OpenMP should regard this DECL as being a scalar which has Fortran's
 252      allocatable or pointer attribute.  */
 253   bool (*omp_is_allocatable_or_ptr) (const_tree);
 254
 255   /* Check whether this DECL belongs to a Fortran optional argument.
 256      With 'for_present_check' set to false, decls which are optional parameters
 257      themselve are returned as tree - or a NULL_TREE otherwise. Those decls are
 258      always pointers.  With 'for_present_check' set to true, the decl for
 259      checking whether an argument is present is returned; for arguments with
 260      value attribute this is the hidden argument and of BOOLEAN_TYPE.  If the
 261      decl is unrelated to optional arguments, NULL_TREE is returned.  */
 262   tree (*omp_check_optional_argument) (tree, bool);
 263
 264   /* True if OpenMP should privatize what this DECL points to rather
 265      than the DECL itself.  */
 266   bool (*omp_privatize_by_reference) (const_tree);
 267
 268   /* Return sharing kind if OpenMP sharing attribute of DECL is
 269      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 270   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 271
 272   /* Return mapping kind if OpenMP mapping attribute of DECL is
 273      predetermined, OMP_CLAUSE_DEFAULTMAP_CATEGORY_UNSPECIFIED otherwise.  */
 274   enum omp_clause_defaultmap_kind (*omp_predetermined_mapping) (tree);
 275
 276   /* Return decl that should be reported for DEFAULT(NONE) failure
 277      diagnostics.  Usually the DECL passed in.  */
 278   tree (*omp_report_decl) (tree);
 279
 280   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 281      disregarded in OpenMP construct, because it is going to be
 282      remapped during OpenMP lowering.  SHARED is true if DECL
 283      is going to be shared, false if it is going to be privatized.  */
 284   bool (*omp_disregard_value_expr) (tree, bool);
 285
 286   /* Return true if DECL that is shared iff SHARED is true should
 287      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 288   bool (*omp_private_debug_clause) (tree, bool);
 289
 290   /* Return true if DECL in private clause needs
 291      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 292   bool (*omp_private_outer_ref) (tree);
 293
 294   /* Build and return code for a default constructor for DECL in
 295      response to CLAUSE.  OUTER is corresponding outer region's
 296      variable if needed.  Return NULL if nothing to be done.  */
 297   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 298
 299   /* Build and return code for a copy constructor from SRC to DST.  */
 300   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 301
 302   /* Similarly, except use an assignment operator instead.  */
 303   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 304
 305   /* Build and return code for a constructor of DST that sets it to
 306      SRC + ADD.  */
 307   tree (*omp_clause_linear_ctor) (tree clause, tree dst, tree src, tree add);
 308
 309   /* Build and return code destructing DECL.  Return NULL if nothing
 310      to be done.  */
 311   tree (*omp_clause_dtor) (tree clause, tree decl);
 312
 313   /* Do language specific checking on an implicitly determined clause.  */
 314   void (*omp_finish_clause) (tree clause, gimple_seq *pre_p, bool);
 315
 316   /* Additional language-specific mappings for a decl; returns true
 317      if those may occur.  */
 318   bool (*omp_deep_mapping_p) (const gimple *ctx_stmt, tree clause);
 319
 320   /* Additional language-specific mappings for a decl; returns the
 321      number of additional mappings needed.  */
 322   tree (*omp_deep_mapping_cnt) (const gimple *ctx_stmt, tree clause,
 323                                 gimple_seq *seq);
 324
 325   /* Do the actual additional language-specific mappings for a decl. */
 326   void (*omp_deep_mapping) (const gimple *stmt, tree clause,
 327                             unsigned HOST_WIDE_INT tkind,
 328                             tree data, tree sizes, tree kinds,
 329                             tree offset_data, tree offset, gimple_seq *seq);
 330
 331   /* Return true if DECL is an allocatable variable (for the purpose of
 332      implicit mapping).  */
 333   bool (*omp_allocatable_p) (tree decl);
 334
 335   /* Return true if DECL is a scalar variable (for the purpose of
 336      implicit firstprivatization). If 'ptr_or', pointers and
 337      allocatables are also permitted.  */
 338   bool (*omp_scalar_p) (tree decl, bool ptr_ok);
 339
 340   /* Return true if DECL is a scalar variable with Fortran target but not
 341      allocatable or pointer attribute (for the purpose of implicit mapping).  */
 342   bool (*omp_scalar_target_p) (tree decl);
 343
 344   /* Return a pointer to the tree representing the initializer
 345      expression for the non-local variable DECL.  Return NULL if
 346      DECL is not initialized.  */
 347   tree *(*omp_get_decl_init) (tree decl);
 348
 349   /* Free any extra memory used to hold initializer information for
 350      variable declarations.  omp_get_decl_init must not be called
 351      after calling this.  */
 352   void (*omp_finish_decl_inits) (void);
 353 };
 354
 355 /* Language hooks related to LTO serialization.  */
 356
 357 struct lang_hooks_for_lto
 358 {
 359   /* Begin a new LTO section named NAME.  */
 360   void (*begin_section) (const char *name);
 361
 362   /* Write DATA of length LEN to the currently open LTO section.  BLOCK is a
 363      pointer to the dynamically allocated memory containing DATA.  The
 364      append_data function is responsible for freeing it when it is no longer
 365      needed.  */
 366   void (*append_data) (const void *data, size_t len, void *block);
 367
 368   /* End the previously begun LTO section.  */
 369   void (*end_section) (void);
 370 };
 371
 372 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 373
 374 struct lang_hooks
 375 {
 376   /* String identifying the front end and optionally language standard
 377      version, e.g. "GNU C++98".  */
 378   const char *name;
 379
 380   /* sizeof (struct lang_identifier), so make_node () creates
 381      identifier nodes long enough for the language-specific slots.  */
 382   size_t identifier_size;
 383
 384   /* Remove any parts of the tree that are used only by the FE. */
 385   void (*free_lang_data) (tree);
 386
 387   /* Determines the size of any language-specific tcc_constant,
 388      tcc_exceptional or tcc_type nodes.  Since it is called from
 389      make_node, the only information available is the tree code.
 390      Expected to die on unrecognized codes.  */
 391   size_t (*tree_size) (enum tree_code);
 392
 393   /* Return the language mask used for converting argv into a sequence
 394      of options.  */
 395   unsigned int (*option_lang_mask) (void);
 396
 397   /* Initialize variables in an options structure.  */
 398   void (*init_options_struct) (struct gcc_options *opts);
 399
 400   /* After the initialize_diagnostics hook is called, do any simple
 401      initialization needed before any calls to handle_option, other
 402      than that done by the init_options_struct hook.  */
 403   void (*init_options) (unsigned int decoded_options_count,
 404                         struct cl_decoded_option *decoded_options);
 405
 406   /* Callback used to perform language-specific initialization for the
 407      global diagnostic context structure.  */
 408   void (*initialize_diagnostics) (diagnostic_context *);
 409
 410   /* Beginning the main source file.  */
 411   void (*preprocess_main_file) (cpp_reader *, line_maps *,
 412                                 const line_map_ordinary *);
 413
 414   /* Adjust libcpp options and callbacks.  */
 415   void (*preprocess_options) (cpp_reader *);
 416
 417   /* Undefining a macro.  */
 418   void (*preprocess_undef) (cpp_reader *, location_t, cpp_hashnode *);
 419
 420   /* Observer for preprocessing stream.  */
 421   uintptr_t (*preprocess_token) (cpp_reader *, const cpp_token *, uintptr_t);
 422   /* Various flags it can return about the token.  */
 423   enum PT_flags
 424     {
 425      PT_begin_pragma = 1 << 0
 426     };
 427
 428   /* Register language-specific dumps.  */
 429   void (*register_dumps) (gcc::dump_manager *);
 430
 431   /* Return true if a warning should be given about option OPTION,
 432      which is for the wrong language, false if it should be quietly
 433      ignored.  */
 434   bool (*complain_wrong_lang_p) (const struct cl_option *option);
 435
 436   /* Handle the switch CODE, which has real type enum opt_code from
 437      options.h.  If the switch takes an argument, it is passed in ARG
 438      which points to permanent storage.  The handler is responsible for
 439      checking whether ARG is NULL, which indicates that no argument
 440      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 441      for the positive and negative forms respectively.  HANDLERS should
 442      be passed to any recursive handle_option calls.  LOC is the
 443      location of the option.
 444
 445      Return true if the switch is valid, false if invalid.  */
 446   bool (*handle_option) (size_t code, const char *arg, HOST_WIDE_INT value,
 447                          int kind, location_t loc,
 448                          const struct cl_option_handlers *handlers);
 449
 450   /* Called when all command line options have been parsed to allow
 451      further processing and initialization
 452
 453      Should return true to indicate that a compiler back-end is
 454      not required, such as with the -E option.
 455
 456      If errorcount is nonzero after this call the compiler exits
 457      immediately and the finish hook is not called.  */
 458   bool (*post_options) (const char **);
 459
 460   /* Called after post_options to initialize the front end.  Return
 461      false to indicate that no further compilation be performed, in
 462      which case the finish hook is called immediately.  */
 463   bool (*init) (void);
 464
 465   /* Called at the end of compilation, as a finalizer.  */
 466   void (*finish) (void);
 467
 468   /* Parses the entire file.  */
 469   void (*parse_file) (void);
 470
 471   /* Determines if it's ok for a function to have no noreturn attribute.  */
 472   bool (*missing_noreturn_ok_p) (tree);
 473
 474   /* Called to obtain the alias set to be used for an expression or type.
 475      Returns -1 if the language does nothing special for it.  */
 476   alias_set_type (*get_alias_set) (tree);
 477
 478   /* Function to finish handling an incomplete decl at the end of
 479      compilation.  Default hook is does nothing.  */
 480   void (*finish_incomplete_decl) (tree);
 481
 482   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 483      DECL_NODE with a newly GC-allocated copy.  */
 484   void (*dup_lang_specific_decl) (tree);
 485
 486   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 487      thing that the assembler should talk about, set
 488      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 489      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 490      assembler does not talk about it.  */
 491   void (*set_decl_assembler_name) (tree);
 492
 493   /* Overwrite the DECL_ASSEMBLER_NAME for a node.  The name is being
 494      changed (including to or from NULL_TREE).  */
 495   void (*overwrite_decl_assembler_name) (tree, tree);
 496
 497   /* The front end can add its own statistics to -fmem-report with
 498      this hook.  It should output to stderr.  */
 499   void (*print_statistics) (void);
 500
 501   /* Called by print_tree when there is a tree of class tcc_exceptional
 502      or tcc_constant that it doesn't know how to display.  */
 503   lang_print_tree_hook print_xnode;
 504
 505   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 506      and IDENTIFIER_NODE nodes.  */
 507   lang_print_tree_hook print_decl;
 508   lang_print_tree_hook print_type;
 509   lang_print_tree_hook print_identifier;
 510
 511   /* Computes the name to use to print a declaration.  DECL is the
 512      non-NULL declaration in question.  VERBOSITY determines what
 513      information will be printed: 0: DECL_NAME, demangled as
 514      necessary.  1: and scope information.  2: and any other
 515      information that might be interesting, such as function parameter
 516      types in C++.  The name is in the internal character set and
 517      needs to be converted to the locale character set of diagnostics,
 518      or to the execution character set for strings such as
 519      __PRETTY_FUNCTION__.  */
 520   const char *(*decl_printable_name) (tree decl, int verbosity);
 521
 522   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 523      information will be printed: 0: DECL_NAME, demangled as
 524      necessary.  1: and scope information.  */
 525   const char *(*dwarf_name) (tree, int verbosity);
 526
 527   /* This compares two types for equivalence ("compatible" in C-based languages).
 528      This routine should only return 1 if it is sure.  It should not be used
 529      in contexts where erroneously returning 0 causes problems.  */
 530   int (*types_compatible_p) (tree x, tree y);
 531
 532   /* Called by diagnostic_report_current_function to print out function name
 533      for textual diagnostic output.  */
 534   void (*print_error_function) (diagnostic_text_output_format &,
 535                                 const char *,
 536                                 const struct diagnostic_info *);
 537
 538   /* Convert a character from the host's to the target's character
 539      set.  The character should be in what C calls the "basic source
 540      character set" (roughly, the set of characters defined by plain
 541      old ASCII).  The default is to return the character unchanged,
 542      which is correct in most circumstances.  Note that both argument
 543      and result should be sign-extended under -fsigned-char,
 544      zero-extended under -fno-signed-char.  */
 545   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 546
 547   /* Pointers to machine-independent attribute tables, for front ends
 548      using attribs.cc.  If one is NULL, it is ignored.  Respectively, a
 549      table of attributes specific to the language, a table of
 550      attributes common to two or more languages (to allow easy
 551      sharing), and a table of attributes for checking formats.  */
 552   array_slice<const struct scoped_attribute_specs *const> attribute_table;
 553
 554   struct lang_hooks_for_tree_inlining tree_inlining;
 555
 556   struct lang_hooks_for_tree_dump tree_dump;
 557
 558   struct lang_hooks_for_decls decls;
 559
 560   struct lang_hooks_for_types types;
 561
 562   struct lang_hooks_for_lto lto;
 563
 564   /* Returns a TREE_VEC of the generic parameters of an instantiation of
 565      a generic type or decl, e.g. C++ template instantiation.  If
 566      TREE_CHAIN of the return value is set, it is an INTEGER_CST
 567      indicating how many of the elements are non-default.  */
 568   tree (*get_innermost_generic_parms) (const_tree);
 569
 570   /* Returns the TREE_VEC of arguments of an instantiation
 571      of a generic type of decl, e.g. C++ template instantiation.  */
 572   tree (*get_innermost_generic_args) (const_tree);
 573
 574   /* Determine if a tree is a function parameter pack.  */
 575   bool (*function_parameter_pack_p) (const_tree);
 576
 577   /* Perform language-specific gimplification on the argument.  Returns an
 578      enum gimplify_status, though we can't see that type here.  */
 579   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 580
 581   /* Do language specific processing in the builtin function DECL  */
 582   tree (*builtin_function) (tree decl);
 583
 584   /* Like builtin_function, but make sure the scope is the external scope.
 585      This is used to delay putting in back end builtin functions until the ISA
 586      that defines the builtin is declared via function specific target options,
 587      which can save memory for machines like the x86_64 that have multiple
 588      ISAs.  If this points to the same function as builtin_function, the
 589      backend must add all of the builtins at program initialization time.  */
 590   tree (*builtin_function_ext_scope) (tree decl);
 591
 592   /* Do language-specific processing for target-specific built-in
 593      function DECL, so that it is defined in the global scope (only)
 594      and is available without needing to be explicitly declared.
 595
 596      This is intended for targets that want to inject declarations of
 597      built-in functions into the source language (such as in response
 598      to a pragma) rather than providing them in the source language itself.  */
 599   tree (*simulate_builtin_function_decl) (tree decl);
 600
 601   /* Used to set up the tree_contains_structure array for a frontend. */
 602   void (*init_ts) (void);
 603
 604   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 605      to a contained expression or DECL, possibly updating *TC or *SE
 606      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 607   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 608
 609   /* The EH personality function decl.  */
 610   tree (*eh_personality) (void);
 611
 612   /* Map a type to a runtime object to match type.  */
 613   tree (*eh_runtime_type) (tree);
 614
 615   /* If non-NULL, this is a function that returns a function decl to be
 616      executed if an unhandled exception is propagated out of a cleanup
 617      region.  For example, in C++, an exception thrown by a destructor
 618      during stack unwinding is required to result in a call to
 619      `std::terminate', so the C++ version of this function returns a
 620      FUNCTION_DECL for `std::terminate'.  */
 621   tree (*eh_protect_cleanup_actions) (void);
 622
 623   /* Return true if a stmt can fallthru.  Used by block_may_fallthru
 624      to possibly handle language trees.  */
 625   bool (*block_may_fallthru) (const_tree);
 626
 627   /* True if this language uses __cxa_end_cleanup when the ARM EABI
 628      is enabled.  */
 629   bool eh_use_cxa_end_cleanup;
 630
 631   /* True if this language requires deep unsharing of tree nodes prior to
 632      gimplification.  */
 633   bool deep_unsharing;
 634
 635   /* True if this language may use custom descriptors for nested functions
 636      instead of trampolines.  */
 637   bool custom_function_descriptors;
 638
 639   /* True if this language emits begin stmt notes.  */
 640   bool emits_begin_stmt;
 641
 642   /* Run all lang-specific selftests.  */
 643   void (*run_lang_selftests) (void);
 644
 645   /* Attempt to determine the source location of the substring.
 646      If successful, return NULL and write the source location to *OUT_LOC.
 647      Otherwise return an error message.  Error messages are intended
 648      for GCC developers (to help debugging) rather than for end-users.  */
 649   const char *(*get_substring_location) (const substring_loc &,
 650                                          location_t *out_loc);
 651
 652   /* Invoked before the early_finish debug hook is invoked.  */
 653   void (*finalize_early_debug) (void);
 654
 655   /* Get a value for the SARIF v2.1.0 "artifact.sourceLanguage" property
 656      for FILENAME, or return NULL.
 657      See SARIF v2.1.0 Appendix J for suggested values for common programming
 658      languages.  */
 659   const char *(*get_sarif_source_language) (const char *filename);
 660
 661   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 662      and langhooks.cc accordingly.  */
 663 };
 664
 665 /* Each front end provides its own.  */
 666 extern struct lang_hooks lang_hooks;
 667
 668 extern tree add_builtin_function (const char *name, tree type,
 669                                   int function_code, enum built_in_class cl,
 670                                   const char *library_name,
 671                                   tree attrs);
 672
 673 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 674                                             int function_code,
 675                                             enum built_in_class cl,
 676                                             const char *library_name,
 677                                             tree attrs);
 678 extern tree simulate_builtin_function_decl (location_t, const char *, tree,
 679                                             int, const char *, tree);
 680 extern tree add_builtin_type (const char *name, tree type);
 681
 682 /* Language helper functions.  */
 683
 684 extern bool lang_GNU_C (void);
 685 extern bool lang_GNU_CXX (void);
 686 extern bool lang_GNU_Fortran (void);
 687 extern bool lang_GNU_OBJC (void);
 688
 689 #endif /* GCC_LANG_HOOKS_H */