gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright (C) 2001-2013 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 /* The following hooks are documented in langhooks.c.  Must not be
  38    NULL.  */
  39
  40 struct lang_hooks_for_tree_inlining
  41 {
  42   bool (*var_mod_type_p) (tree, tree);
  43 };
  44
  45 /* The following hooks are used by tree-dump.c.  */
  46
  47 struct lang_hooks_for_tree_dump
  48 {
  49   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  50      does not want the usual dumping of the second argument.  */
  51   bool (*dump_tree) (void *, tree);
  52
  53   /* Determine type qualifiers in a language-specific way.  */
  54   int (*type_quals) (const_tree);
  55 };
  56
  57 /* Hooks related to types.  */
  58
  59 struct lang_hooks_for_types
  60 {
  61   /* Return a new type (with the indicated CODE), doing whatever
  62      language-specific processing is required.  */
  63   tree (*make_type) (enum tree_code);
  64
  65   /* Return what kind of RECORD_TYPE this is, mainly for purposes of
  66      debug information.  If not defined, record types are assumed to
  67      be structures.  */
  68   enum classify_record (*classify_record) (tree);
  69
  70   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  71      mode.  */
  72   tree (*type_for_mode) (enum machine_mode, int);
  73
  74   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
  75      integer type with at least that precision.  */
  76   tree (*type_for_size) (unsigned, int);
  77
  78   /* True if the type is an instantiation of a generic type,
  79      e.g. C++ template implicit specializations.  */
  80   bool (*generic_p) (const_tree);
  81
  82   /* Returns the TREE_VEC of elements of a given generic argument pack.  */
  83   tree (*get_argument_pack_elems) (const_tree);
  84
  85   /* Given a type, apply default promotions to unnamed function
  86      arguments and return the new type.  Return the same type if no
  87      change.  Required by any language that supports variadic
  88      arguments.  The default hook dies.  */
  89   tree (*type_promotes_to) (tree);
  90
  91   /* Register TYPE as a builtin type with the indicated NAME.  The
  92      TYPE is placed in the outermost lexical scope.  The semantics
  93      should be analogous to:
  94
  95        typedef TYPE NAME;
  96
  97      in C.  The default hook ignores the declaration.  */
  98   void (*register_builtin_type) (tree, const char *);
  99
 100   /* This routine is called in tree.c to print an error message for
 101      invalid use of an incomplete type.  VALUE is the expression that
 102      was used (or 0 if that isn't known) and TYPE is the type that was
 103      invalid.  */
 104   void (*incomplete_type_error) (const_tree value, const_tree type);
 105
 106   /* Called from assign_temp to return the maximum size, if there is one,
 107      for a type.  */
 108   tree (*max_size) (const_tree);
 109
 110   /* Register language specific type size variables as potentially OpenMP
 111      firstprivate variables.  */
 112   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 113
 114   /* Return true if TYPE is a mappable type.  */
 115   bool (*omp_mappable_type) (tree type);
 116
 117   /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
 118      Called only after doing all language independent checks.
 119      At present, this function is only called when both TYPE1 and TYPE2 are
 120      FUNCTION_TYPEs.  */
 121   bool (*type_hash_eq) (const_tree, const_tree);
 122
 123   /* Return TRUE if TYPE uses a hidden descriptor and fills in information
 124      for the debugger about the array bounds, strides, etc.  */
 125   bool (*get_array_descr_info) (const_tree, struct array_descr_info *);
 126
 127   /* Fill in information for the debugger about the bounds of TYPE.  */
 128   void (*get_subrange_bounds) (const_tree, tree *, tree *);
 129
 130   /* A type descriptive of TYPE's complex layout generated to help the
 131      debugger to decode variable-length or self-referential constructs.
 132      This is only used for the AT_GNAT_descriptive_type DWARF attribute.  */
 133   tree (*descriptive_type) (const_tree);
 134
 135   /* If we requested a pointer to a vector, build up the pointers that
 136      we stripped off while looking for the inner type.  Similarly for
 137      return values from functions.  The argument TYPE is the top of the
 138      chain, and BOTTOM is the new type which we will point to.  */
 139   tree (*reconstruct_complex_type) (tree, tree);
 140 };
 141
 142 /* Language hooks related to Cilk Plus.  */
 143
 144 struct lang_hooks_for_cilkplus
 145 {
 146   /* Returns true if the expression passed in has a spawned function call.  */
 147   bool (*cilk_detect_spawn_and_unwrap) (tree *);
 148
 149   /* Function to add the clean up functions after spawn.  The reason why it is
 150      language dependent is because in C++, it must handle exceptions.  */
 151   void (*install_body_with_frame_cleanup) (tree, tree);
 152
 153   /* Function to gimplify a spawned function call.  Returns enum gimplify
 154      status, but as mentioned in a previous comment, we can't see that type
 155      here, so just return an int.  */
 156   int (*gimplify_cilk_spawn) (tree *, gimple_seq *, gimple_seq *);
 157 };
 158
 159 /* Language hooks related to decls and the symbol table.  */
 160
 161 struct lang_hooks_for_decls
 162 {
 163   /* Return true if we are in the global binding level.  This hook is really
 164      needed only if the language supports variable-sized types at the global
 165      level, i.e. declared outside subprograms.  */
 166   bool (*global_bindings_p) (void);
 167
 168   /* Function to add a decl to the current scope level.  Takes one
 169      argument, a decl to add.  Returns that decl, or, if the same
 170      symbol is already declared, may return a different decl for that
 171      name.  */
 172   tree (*pushdecl) (tree);
 173
 174   /* Returns the chain of decls so far in the current scope level.  */
 175   tree (*getdecls) (void);
 176
 177   /* Returns true if DECL is explicit member function.  */
 178   bool (*function_decl_explicit_p) (tree);
 179
 180   /* Returns True if the parameter is a generic parameter decl
 181      of a generic type, e.g a template template parameter for the C++ FE.  */
 182   bool (*generic_generic_parameter_decl_p) (const_tree);
 183
 184   /* Determine if a function parameter got expanded from a
 185      function parameter pack.  */
 186   bool (*function_parm_expanded_from_pack_p) (tree, tree);
 187
 188   /* Returns the generic declaration of a generic function instantiations.  */
 189   tree (*get_generic_function_decl) (const_tree);
 190
 191   /* Returns true when we should warn for an unused global DECL.
 192      We will already have checked that it has static binding.  */
 193   bool (*warn_unused_global) (const_tree);
 194
 195   /* Obtain a list of globals and do final output on them at end
 196      of compilation */
 197   void (*final_write_globals) (void);
 198
 199   /* True if this decl may be called via a sibcall.  */
 200   bool (*ok_for_sibcall) (const_tree);
 201
 202   /* True if OpenMP should privatize what this DECL points to rather
 203      than the DECL itself.  */
 204   bool (*omp_privatize_by_reference) (const_tree);
 205
 206   /* Return sharing kind if OpenMP sharing attribute of DECL is
 207      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 208   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 209
 210   /* Return decl that should be reported for DEFAULT(NONE) failure
 211      diagnostics.  Usually the DECL passed in.  */
 212   tree (*omp_report_decl) (tree);
 213
 214   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 215      disregarded in OpenMP construct, because it is going to be
 216      remapped during OpenMP lowering.  SHARED is true if DECL
 217      is going to be shared, false if it is going to be privatized.  */
 218   bool (*omp_disregard_value_expr) (tree, bool);
 219
 220   /* Return true if DECL that is shared iff SHARED is true should
 221      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 222   bool (*omp_private_debug_clause) (tree, bool);
 223
 224   /* Return true if DECL in private clause needs
 225      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 226   bool (*omp_private_outer_ref) (tree);
 227
 228   /* Build and return code for a default constructor for DECL in
 229      response to CLAUSE.  OUTER is corresponding outer region's
 230      variable if needed.  Return NULL if nothing to be done.  */
 231   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 232
 233   /* Build and return code for a copy constructor from SRC to DST.  */
 234   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 235
 236   /* Similarly, except use an assignment operator instead.  */
 237   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 238
 239   /* Build and return code destructing DECL.  Return NULL if nothing
 240      to be done.  */
 241   tree (*omp_clause_dtor) (tree clause, tree decl);
 242
 243   /* Do language specific checking on an implicitly determined clause.  */
 244   void (*omp_finish_clause) (tree clause);
 245 };
 246
 247 /* Language hooks related to LTO serialization.  */
 248
 249 struct lang_hooks_for_lto
 250 {
 251   /* Begin a new LTO section named NAME.  */
 252   void (*begin_section) (const char *name);
 253
 254   /* Write DATA of length LEN to the currently open LTO section.  BLOCK is a
 255      pointer to the dynamically allocated memory containing DATA.  The
 256      append_data function is responsible for freeing it when it is no longer
 257      needed.  */
 258   void (*append_data) (const void *data, size_t len, void *block);
 259
 260   /* End the previously begun LTO section.  */
 261   void (*end_section) (void);
 262 };
 263
 264 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 265
 266 struct lang_hooks
 267 {
 268   /* String identifying the front end.  e.g. "GNU C++".  */
 269   const char *name;
 270
 271   /* sizeof (struct lang_identifier), so make_node () creates
 272      identifier nodes long enough for the language-specific slots.  */
 273   size_t identifier_size;
 274
 275   /* Remove any parts of the tree that are used only by the FE. */
 276   void (*free_lang_data) (tree);
 277
 278   /* Determines the size of any language-specific tcc_constant or
 279      tcc_exceptional nodes.  Since it is called from make_node, the
 280      only information available is the tree code.  Expected to die
 281      on unrecognized codes.  */
 282   size_t (*tree_size) (enum tree_code);
 283
 284   /* Return the language mask used for converting argv into a sequence
 285      of options.  */
 286   unsigned int (*option_lang_mask) (void);
 287
 288   /* Initialize variables in an options structure.  */
 289   void (*init_options_struct) (struct gcc_options *opts);
 290
 291   /* After the initialize_diagnostics hook is called, do any simple
 292      initialization needed before any calls to handle_option, other
 293      than that done by the init_options_struct hook.  */
 294   void (*init_options) (unsigned int decoded_options_count,
 295                         struct cl_decoded_option *decoded_options);
 296
 297   /* Callback used to perform language-specific initialization for the
 298      global diagnostic context structure.  */
 299   void (*initialize_diagnostics) (diagnostic_context *);
 300
 301   /* Return true if a warning should be given about option OPTION,
 302      which is for the wrong language, false if it should be quietly
 303      ignored.  */
 304   bool (*complain_wrong_lang_p) (const struct cl_option *option);
 305
 306   /* Handle the switch CODE, which has real type enum opt_code from
 307      options.h.  If the switch takes an argument, it is passed in ARG
 308      which points to permanent storage.  The handler is responsible for
 309      checking whether ARG is NULL, which indicates that no argument
 310      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 311      for the positive and negative forms respectively.  HANDLERS should
 312      be passed to any recursive handle_option calls.  LOC is the
 313      location of the option.
 314
 315      Return true if the switch is valid, false if invalid.  */
 316   bool (*handle_option) (size_t code, const char *arg, int value, int kind,
 317                          location_t loc,
 318                          const struct cl_option_handlers *handlers);
 319
 320   /* Called when all command line options have been parsed to allow
 321      further processing and initialization
 322
 323      Should return true to indicate that a compiler back-end is
 324      not required, such as with the -E option.
 325
 326      If errorcount is nonzero after this call the compiler exits
 327      immediately and the finish hook is not called.  */
 328   bool (*post_options) (const char **);
 329
 330   /* Called after post_options to initialize the front end.  Return
 331      false to indicate that no further compilation be performed, in
 332      which case the finish hook is called immediately.  */
 333   bool (*init) (void);
 334
 335   /* Called at the end of compilation, as a finalizer.  */
 336   void (*finish) (void);
 337
 338   /* Parses the entire file.  */
 339   void (*parse_file) (void);
 340
 341   /* Determines if it's ok for a function to have no noreturn attribute.  */
 342   bool (*missing_noreturn_ok_p) (tree);
 343
 344   /* Called to obtain the alias set to be used for an expression or type.
 345      Returns -1 if the language does nothing special for it.  */
 346   alias_set_type (*get_alias_set) (tree);
 347
 348   /* Function to finish handling an incomplete decl at the end of
 349      compilation.  Default hook is does nothing.  */
 350   void (*finish_incomplete_decl) (tree);
 351
 352   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 353      DECL_NODE with a newly GC-allocated copy.  */
 354   void (*dup_lang_specific_decl) (tree);
 355
 356   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 357      thing that the assembler should talk about, set
 358      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 359      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 360      assembler does not talk about it.  */
 361   void (*set_decl_assembler_name) (tree);
 362
 363   /* The front end can add its own statistics to -fmem-report with
 364      this hook.  It should output to stderr.  */
 365   void (*print_statistics) (void);
 366
 367   /* Called by print_tree when there is a tree of class tcc_exceptional
 368      that it doesn't know how to display.  */
 369   lang_print_tree_hook print_xnode;
 370
 371   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 372      and IDENTIFIER_NODE nodes.  */
 373   lang_print_tree_hook print_decl;
 374   lang_print_tree_hook print_type;
 375   lang_print_tree_hook print_identifier;
 376
 377   /* Computes the name to use to print a declaration.  DECL is the
 378      non-NULL declaration in question.  VERBOSITY determines what
 379      information will be printed: 0: DECL_NAME, demangled as
 380      necessary.  1: and scope information.  2: and any other
 381      information that might be interesting, such as function parameter
 382      types in C++.  The name is in the internal character set and
 383      needs to be converted to the locale character set of diagnostics,
 384      or to the execution character set for strings such as
 385      __PRETTY_FUNCTION__.  */
 386   const char *(*decl_printable_name) (tree decl, int verbosity);
 387
 388   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 389      information will be printed: 0: DECL_NAME, demangled as
 390      necessary.  1: and scope information.  */
 391   const char *(*dwarf_name) (tree, int verbosity);
 392
 393   /* This compares two types for equivalence ("compatible" in C-based languages).
 394      This routine should only return 1 if it is sure.  It should not be used
 395      in contexts where erroneously returning 0 causes problems.  */
 396   int (*types_compatible_p) (tree x, tree y);
 397
 398   /* Called by report_error_function to print out function name.  */
 399   void (*print_error_function) (diagnostic_context *, const char *,
 400                                 struct diagnostic_info *);
 401
 402   /* Convert a character from the host's to the target's character
 403      set.  The character should be in what C calls the "basic source
 404      character set" (roughly, the set of characters defined by plain
 405      old ASCII).  The default is to return the character unchanged,
 406      which is correct in most circumstances.  Note that both argument
 407      and result should be sign-extended under -fsigned-char,
 408      zero-extended under -fno-signed-char.  */
 409   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 410
 411   /* Pointers to machine-independent attribute tables, for front ends
 412      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 413      table of attributes specific to the language, a table of
 414      attributes common to two or more languages (to allow easy
 415      sharing), and a table of attributes for checking formats.  */
 416   const struct attribute_spec *attribute_table;
 417   const struct attribute_spec *common_attribute_table;
 418   const struct attribute_spec *format_attribute_table;
 419
 420   struct lang_hooks_for_tree_inlining tree_inlining;
 421
 422   struct lang_hooks_for_tree_dump tree_dump;
 423
 424   struct lang_hooks_for_decls decls;
 425
 426   struct lang_hooks_for_types types;
 427
 428   struct lang_hooks_for_cilkplus cilkplus;
 429
 430   struct lang_hooks_for_lto lto;
 431
 432   /* Returns a TREE_VEC of the generic parameters of an instantiation of
 433      a generic type or decl, e.g. C++ template instantiation.  If
 434      TREE_CHAIN of the return value is set, it is an INTEGER_CST
 435      indicating how many of the elements are non-default.  */
 436   tree (*get_innermost_generic_parms) (const_tree);
 437
 438   /* Returns the TREE_VEC of arguments of an instantiation
 439      of a generic type of decl, e.g. C++ template instantiation.  */
 440   tree (*get_innermost_generic_args) (const_tree);
 441
 442   /* Determine if a tree is a function parameter pack.  */
 443   bool (*function_parameter_pack_p) (const_tree);
 444
 445   /* Perform language-specific gimplification on the argument.  Returns an
 446      enum gimplify_status, though we can't see that type here.  */
 447   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 448
 449   /* Do language specific processing in the builtin function DECL  */
 450   tree (*builtin_function) (tree decl);
 451
 452   /* Like builtin_function, but make sure the scope is the external scope.
 453      This is used to delay putting in back end builtin functions until the ISA
 454      that defines the builtin is declared via function specific target options,
 455      which can save memory for machines like the x86_64 that have multiple
 456      ISAs.  If this points to the same function as builtin_function, the
 457      backend must add all of the builtins at program initialization time.  */
 458   tree (*builtin_function_ext_scope) (tree decl);
 459
 460   /* Used to set up the tree_contains_structure array for a frontend. */
 461   void (*init_ts) (void);
 462
 463   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 464      to a contained expression or DECL, possibly updating *TC or *SE
 465      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 466   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 467
 468   /* The EH personality function decl.  */
 469   tree (*eh_personality) (void);
 470
 471   /* Map a type to a runtime object to match type.  */
 472   tree (*eh_runtime_type) (tree);
 473
 474   /* If non-NULL, this is a function that returns a function decl to be
 475      executed if an unhandled exception is propagated out of a cleanup
 476      region.  For example, in C++, an exception thrown by a destructor
 477      during stack unwinding is required to result in a call to
 478      `std::terminate', so the C++ version of this function returns a
 479      FUNCTION_DECL for `std::terminate'.  */
 480   tree (*eh_protect_cleanup_actions) (void);
 481
 482   /* Return true if a stmt can fallthru.  Used by block_may_fallthru
 483      to possibly handle language trees.  */
 484   bool (*block_may_fallthru) (const_tree);
 485
 486   /* True if this language uses __cxa_end_cleanup when the ARM EABI
 487      is enabled.  */
 488   bool eh_use_cxa_end_cleanup;
 489
 490   /* True if this language requires deep unsharing of tree nodes prior to
 491      gimplification.  */
 492   bool deep_unsharing;
 493
 494   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 495      and langhooks.c accordingly.  */
 496 };
 497
 498 /* Each front end provides its own.  */
 499 extern struct lang_hooks lang_hooks;
 500
 501 extern tree add_builtin_function (const char *name, tree type,
 502                                   int function_code, enum built_in_class cl,
 503                                   const char *library_name,
 504                                   tree attrs);
 505
 506 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 507                                             int function_code,
 508                                             enum built_in_class cl,
 509                                             const char *library_name,
 510                                             tree attrs);
 511 extern tree add_builtin_type (const char *name, tree type);
 512
 513 #endif /* GCC_LANG_HOOKS_H */