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