gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright (C) 2001-2014 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 decls and the symbol table.  */
 143
 144 struct lang_hooks_for_decls
 145 {
 146   /* Return true if we are in the global binding level.  This hook is really
 147      needed only if the language supports variable-sized types at the global
 148      level, i.e. declared outside subprograms.  */
 149   bool (*global_bindings_p) (void);
 150
 151   /* Function to add a decl to the current scope level.  Takes one
 152      argument, a decl to add.  Returns that decl, or, if the same
 153      symbol is already declared, may return a different decl for that
 154      name.  */
 155   tree (*pushdecl) (tree);
 156
 157   /* Returns the chain of decls so far in the current scope level.  */
 158   tree (*getdecls) (void);
 159
 160   /* Returns true if DECL is explicit member function.  */
 161   bool (*function_decl_explicit_p) (tree);
 162
 163   /* Returns True if the parameter is a generic parameter decl
 164      of a generic type, e.g a template template parameter for the C++ FE.  */
 165   bool (*generic_generic_parameter_decl_p) (const_tree);
 166
 167   /* Determine if a function parameter got expanded from a
 168      function parameter pack.  */
 169   bool (*function_parm_expanded_from_pack_p) (tree, tree);
 170
 171   /* Returns the generic declaration of a generic function instantiations.  */
 172   tree (*get_generic_function_decl) (const_tree);
 173
 174   /* Returns true when we should warn for an unused global DECL.
 175      We will already have checked that it has static binding.  */
 176   bool (*warn_unused_global) (const_tree);
 177
 178   /* Obtain a list of globals and do final output on them at end
 179      of compilation */
 180   void (*final_write_globals) (void);
 181
 182   /* True if this decl may be called via a sibcall.  */
 183   bool (*ok_for_sibcall) (const_tree);
 184
 185   /* True if OpenMP should privatize what this DECL points to rather
 186      than the DECL itself.  */
 187   bool (*omp_privatize_by_reference) (const_tree);
 188
 189   /* Return sharing kind if OpenMP sharing attribute of DECL is
 190      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 191   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 192
 193   /* Return decl that should be reported for DEFAULT(NONE) failure
 194      diagnostics.  Usually the DECL passed in.  */
 195   tree (*omp_report_decl) (tree);
 196
 197   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 198      disregarded in OpenMP construct, because it is going to be
 199      remapped during OpenMP lowering.  SHARED is true if DECL
 200      is going to be shared, false if it is going to be privatized.  */
 201   bool (*omp_disregard_value_expr) (tree, bool);
 202
 203   /* Return true if DECL that is shared iff SHARED is true should
 204      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 205   bool (*omp_private_debug_clause) (tree, bool);
 206
 207   /* Return true if DECL in private clause needs
 208      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 209   bool (*omp_private_outer_ref) (tree);
 210
 211   /* Build and return code for a default constructor for DECL in
 212      response to CLAUSE.  OUTER is corresponding outer region's
 213      variable if needed.  Return NULL if nothing to be done.  */
 214   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 215
 216   /* Build and return code for a copy constructor from SRC to DST.  */
 217   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 218
 219   /* Similarly, except use an assignment operator instead.  */
 220   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 221
 222   /* Build and return code destructing DECL.  Return NULL if nothing
 223      to be done.  */
 224   tree (*omp_clause_dtor) (tree clause, tree decl);
 225
 226   /* Do language specific checking on an implicitly determined clause.  */
 227   void (*omp_finish_clause) (tree clause);
 228 };
 229
 230 /* Language hooks related to LTO serialization.  */
 231
 232 struct lang_hooks_for_lto
 233 {
 234   /* Begin a new LTO section named NAME.  */
 235   void (*begin_section) (const char *name);
 236
 237   /* Write DATA of length LEN to the currently open LTO section.  BLOCK is a
 238      pointer to the dynamically allocated memory containing DATA.  The
 239      append_data function is responsible for freeing it when it is no longer
 240      needed.  */
 241   void (*append_data) (const void *data, size_t len, void *block);
 242
 243   /* End the previously begun LTO section.  */
 244   void (*end_section) (void);
 245 };
 246
 247 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 248
 249 struct lang_hooks
 250 {
 251   /* String identifying the front end.  e.g. "GNU C++".  */
 252   const char *name;
 253
 254   /* sizeof (struct lang_identifier), so make_node () creates
 255      identifier nodes long enough for the language-specific slots.  */
 256   size_t identifier_size;
 257
 258   /* Remove any parts of the tree that are used only by the FE. */
 259   void (*free_lang_data) (tree);
 260
 261   /* Determines the size of any language-specific tcc_constant or
 262      tcc_exceptional nodes.  Since it is called from make_node, the
 263      only information available is the tree code.  Expected to die
 264      on unrecognized codes.  */
 265   size_t (*tree_size) (enum tree_code);
 266
 267   /* Return the language mask used for converting argv into a sequence
 268      of options.  */
 269   unsigned int (*option_lang_mask) (void);
 270
 271   /* Initialize variables in an options structure.  */
 272   void (*init_options_struct) (struct gcc_options *opts);
 273
 274   /* After the initialize_diagnostics hook is called, do any simple
 275      initialization needed before any calls to handle_option, other
 276      than that done by the init_options_struct hook.  */
 277   void (*init_options) (unsigned int decoded_options_count,
 278                         struct cl_decoded_option *decoded_options);
 279
 280   /* Callback used to perform language-specific initialization for the
 281      global diagnostic context structure.  */
 282   void (*initialize_diagnostics) (diagnostic_context *);
 283
 284   /* Return true if a warning should be given about option OPTION,
 285      which is for the wrong language, false if it should be quietly
 286      ignored.  */
 287   bool (*complain_wrong_lang_p) (const struct cl_option *option);
 288
 289   /* Handle the switch CODE, which has real type enum opt_code from
 290      options.h.  If the switch takes an argument, it is passed in ARG
 291      which points to permanent storage.  The handler is responsible for
 292      checking whether ARG is NULL, which indicates that no argument
 293      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 294      for the positive and negative forms respectively.  HANDLERS should
 295      be passed to any recursive handle_option calls.  LOC is the
 296      location of the option.
 297
 298      Return true if the switch is valid, false if invalid.  */
 299   bool (*handle_option) (size_t code, const char *arg, int value, int kind,
 300                          location_t loc,
 301                          const struct cl_option_handlers *handlers);
 302
 303   /* Called when all command line options have been parsed to allow
 304      further processing and initialization
 305
 306      Should return true to indicate that a compiler back-end is
 307      not required, such as with the -E option.
 308
 309      If errorcount is nonzero after this call the compiler exits
 310      immediately and the finish hook is not called.  */
 311   bool (*post_options) (const char **);
 312
 313   /* Called after post_options to initialize the front end.  Return
 314      false to indicate that no further compilation be performed, in
 315      which case the finish hook is called immediately.  */
 316   bool (*init) (void);
 317
 318   /* Called at the end of compilation, as a finalizer.  */
 319   void (*finish) (void);
 320
 321   /* Parses the entire file.  */
 322   void (*parse_file) (void);
 323
 324   /* Determines if it's ok for a function to have no noreturn attribute.  */
 325   bool (*missing_noreturn_ok_p) (tree);
 326
 327   /* Called to obtain the alias set to be used for an expression or type.
 328      Returns -1 if the language does nothing special for it.  */
 329   alias_set_type (*get_alias_set) (tree);
 330
 331   /* Function to finish handling an incomplete decl at the end of
 332      compilation.  Default hook is does nothing.  */
 333   void (*finish_incomplete_decl) (tree);
 334
 335   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 336      DECL_NODE with a newly GC-allocated copy.  */
 337   void (*dup_lang_specific_decl) (tree);
 338
 339   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 340      thing that the assembler should talk about, set
 341      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 342      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 343      assembler does not talk about it.  */
 344   void (*set_decl_assembler_name) (tree);
 345
 346   /* The front end can add its own statistics to -fmem-report with
 347      this hook.  It should output to stderr.  */
 348   void (*print_statistics) (void);
 349
 350   /* Called by print_tree when there is a tree of class tcc_exceptional
 351      that it doesn't know how to display.  */
 352   lang_print_tree_hook print_xnode;
 353
 354   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 355      and IDENTIFIER_NODE nodes.  */
 356   lang_print_tree_hook print_decl;
 357   lang_print_tree_hook print_type;
 358   lang_print_tree_hook print_identifier;
 359
 360   /* Computes the name to use to print a declaration.  DECL is the
 361      non-NULL declaration in question.  VERBOSITY determines what
 362      information will be printed: 0: DECL_NAME, demangled as
 363      necessary.  1: and scope information.  2: and any other
 364      information that might be interesting, such as function parameter
 365      types in C++.  The name is in the internal character set and
 366      needs to be converted to the locale character set of diagnostics,
 367      or to the execution character set for strings such as
 368      __PRETTY_FUNCTION__.  */
 369   const char *(*decl_printable_name) (tree decl, int verbosity);
 370
 371   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 372      information will be printed: 0: DECL_NAME, demangled as
 373      necessary.  1: and scope information.  */
 374   const char *(*dwarf_name) (tree, int verbosity);
 375
 376   /* This compares two types for equivalence ("compatible" in C-based languages).
 377      This routine should only return 1 if it is sure.  It should not be used
 378      in contexts where erroneously returning 0 causes problems.  */
 379   int (*types_compatible_p) (tree x, tree y);
 380
 381   /* Called by report_error_function to print out function name.  */
 382   void (*print_error_function) (diagnostic_context *, const char *,
 383                                 struct diagnostic_info *);
 384
 385   /* Convert a character from the host's to the target's character
 386      set.  The character should be in what C calls the "basic source
 387      character set" (roughly, the set of characters defined by plain
 388      old ASCII).  The default is to return the character unchanged,
 389      which is correct in most circumstances.  Note that both argument
 390      and result should be sign-extended under -fsigned-char,
 391      zero-extended under -fno-signed-char.  */
 392   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 393
 394   /* Pointers to machine-independent attribute tables, for front ends
 395      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 396      table of attributes specific to the language, a table of
 397      attributes common to two or more languages (to allow easy
 398      sharing), and a table of attributes for checking formats.  */
 399   const struct attribute_spec *attribute_table;
 400   const struct attribute_spec *common_attribute_table;
 401   const struct attribute_spec *format_attribute_table;
 402
 403   struct lang_hooks_for_tree_inlining tree_inlining;
 404
 405   struct lang_hooks_for_tree_dump tree_dump;
 406
 407   struct lang_hooks_for_decls decls;
 408
 409   struct lang_hooks_for_types types;
 410
 411   struct lang_hooks_for_lto lto;
 412
 413   /* Returns a TREE_VEC of the generic parameters of an instantiation of
 414      a generic type or decl, e.g. C++ template instantiation.  If
 415      TREE_CHAIN of the return value is set, it is an INTEGER_CST
 416      indicating how many of the elements are non-default.  */
 417   tree (*get_innermost_generic_parms) (const_tree);
 418
 419   /* Returns the TREE_VEC of arguments of an instantiation
 420      of a generic type of decl, e.g. C++ template instantiation.  */
 421   tree (*get_innermost_generic_args) (const_tree);
 422
 423   /* Determine if a tree is a function parameter pack.  */
 424   bool (*function_parameter_pack_p) (const_tree);
 425
 426   /* Perform language-specific gimplification on the argument.  Returns an
 427      enum gimplify_status, though we can't see that type here.  */
 428   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 429
 430   /* Do language specific processing in the builtin function DECL  */
 431   tree (*builtin_function) (tree decl);
 432
 433   /* Like builtin_function, but make sure the scope is the external scope.
 434      This is used to delay putting in back end builtin functions until the ISA
 435      that defines the builtin is declared via function specific target options,
 436      which can save memory for machines like the x86_64 that have multiple
 437      ISAs.  If this points to the same function as builtin_function, the
 438      backend must add all of the builtins at program initialization time.  */
 439   tree (*builtin_function_ext_scope) (tree decl);
 440
 441   /* Used to set up the tree_contains_structure array for a frontend. */
 442   void (*init_ts) (void);
 443
 444   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 445      to a contained expression or DECL, possibly updating *TC or *SE
 446      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 447   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 448
 449   /* The EH personality function decl.  */
 450   tree (*eh_personality) (void);
 451
 452   /* Map a type to a runtime object to match type.  */
 453   tree (*eh_runtime_type) (tree);
 454
 455   /* If non-NULL, this is a function that returns a function decl to be
 456      executed if an unhandled exception is propagated out of a cleanup
 457      region.  For example, in C++, an exception thrown by a destructor
 458      during stack unwinding is required to result in a call to
 459      `std::terminate', so the C++ version of this function returns a
 460      FUNCTION_DECL for `std::terminate'.  */
 461   tree (*eh_protect_cleanup_actions) (void);
 462
 463   /* Return true if a stmt can fallthru.  Used by block_may_fallthru
 464      to possibly handle language trees.  */
 465   bool (*block_may_fallthru) (const_tree);
 466
 467   /* True if this language uses __cxa_end_cleanup when the ARM EABI
 468      is enabled.  */
 469   bool eh_use_cxa_end_cleanup;
 470
 471   /* True if this language requires deep unsharing of tree nodes prior to
 472      gimplification.  */
 473   bool deep_unsharing;
 474
 475   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 476      and langhooks.c accordingly.  */
 477 };
 478
 479 /* Each front end provides its own.  */
 480 extern struct lang_hooks lang_hooks;
 481
 482 extern tree add_builtin_function (const char *name, tree type,
 483                                   int function_code, enum built_in_class cl,
 484                                   const char *library_name,
 485                                   tree attrs);
 486
 487 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 488                                             int function_code,
 489                                             enum built_in_class cl,
 490                                             const char *library_name,
 491                                             tree attrs);
 492 extern tree add_builtin_type (const char *name, tree type);
 493
 494 #endif /* GCC_LANG_HOOKS_H */