gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
   3    2011 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef GCC_LANG_HOOKS_H
  22 #define GCC_LANG_HOOKS_H
  23
  24 /* This file should be #include-d after tree.h.  */
  25
  26 struct diagnostic_info;
  27
  28 struct gimplify_omp_ctx;
  29
  30 struct array_descr_info;
  31
  32 /* A print hook for print_tree ().  */
  33 typedef void (*lang_print_tree_hook) (FILE *, tree, int indent);
  34
  35 enum classify_record
  36   { RECORD_IS_STRUCT, RECORD_IS_CLASS, RECORD_IS_INTERFACE };
  37
  38 /* The following hooks are documented in langhooks.c.  Must not be
  39    NULL.  */
  40
  41 struct lang_hooks_for_tree_inlining
  42 {
  43   bool (*var_mod_type_p) (tree, tree);
  44 };
  45
  46 struct lang_hooks_for_callgraph
  47 {
  48   /* The node passed is a language-specific tree node.  If its contents
  49      are relevant to use of other declarations, mark them.  */
  50   tree (*analyze_expr) (tree *, int *);
  51 };
  52
  53 /* The following hooks are used by tree-dump.c.  */
  54
  55 struct lang_hooks_for_tree_dump
  56 {
  57   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  58      does not want the usual dumping of the second argument.  */
  59   bool (*dump_tree) (void *, tree);
  60
  61   /* Determine type qualifiers in a language-specific way.  */
  62   int (*type_quals) (const_tree);
  63 };
  64
  65 /* Hooks related to types.  */
  66
  67 struct lang_hooks_for_types
  68 {
  69   /* Return a new type (with the indicated CODE), doing whatever
  70      language-specific processing is required.  */
  71   tree (*make_type) (enum tree_code);
  72
  73   /* Return what kind of RECORD_TYPE this is, mainly for purposes of
  74      debug information.  If not defined, record types are assumed to
  75      be structures.  */
  76   enum classify_record (*classify_record) (tree);
  77
  78   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  79      mode.  */
  80   tree (*type_for_mode) (enum machine_mode, int);
  81
  82   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
  83      integer type with at least that precision.  */
  84   tree (*type_for_size) (unsigned, int);
  85
  86   /* True if the type is an instantiation of a generic type,
  87      e.g. C++ template implicit specializations.  */
  88   bool (*generic_p) (const_tree);
  89
  90   /* Returns the TREE_VEC of elements of a given generic argument pack.  */
  91   tree (*get_argument_pack_elems) (const_tree);
  92
  93   /* Given a type, apply default promotions to unnamed function
  94      arguments and return the new type.  Return the same type if no
  95      change.  Required by any language that supports variadic
  96      arguments.  The default hook dies.  */
  97   tree (*type_promotes_to) (tree);
  98
  99   /* Register TYPE as a builtin type with the indicated NAME.  The
 100      TYPE is placed in the outermost lexical scope.  The semantics
 101      should be analogous to:
 102
 103        typedef TYPE NAME;
 104
 105      in C.  The default hook ignores the declaration.  */
 106   void (*register_builtin_type) (tree, const char *);
 107
 108   /* This routine is called in tree.c to print an error message for
 109      invalid use of an incomplete type.  VALUE is the expression that
 110      was used (or 0 if that isn't known) and TYPE is the type that was
 111      invalid.  */
 112   void (*incomplete_type_error) (const_tree value, const_tree type);
 113
 114   /* Called from assign_temp to return the maximum size, if there is one,
 115      for a type.  */
 116   tree (*max_size) (const_tree);
 117
 118   /* Register language specific type size variables as potentially OpenMP
 119      firstprivate variables.  */
 120   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 121
 122   /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
 123      Called only after doing all language independent checks.
 124      At present, this function is only called when both TYPE1 and TYPE2 are
 125      FUNCTION_TYPEs.  */
 126   bool (*type_hash_eq) (const_tree, const_tree);
 127
 128   /* Return TRUE if TYPE uses a hidden descriptor and fills in information
 129      for the debugger about the array bounds, strides, etc.  */
 130   bool (*get_array_descr_info) (const_tree, struct array_descr_info *);
 131
 132   /* Fill in information for the debugger about the bounds of TYPE.  */
 133   void (*get_subrange_bounds) (const_tree, tree *, tree *);
 134
 135   /* A type descriptive of TYPE's complex layout generated to help the
 136      debugger to decode variable-length or self-referential constructs.
 137      This is only used for the AT_GNAT_descriptive_type DWARF attribute.  */
 138   tree (*descriptive_type) (const_tree);
 139
 140   /* If we requested a pointer to a vector, build up the pointers that
 141      we stripped off while looking for the inner type.  Similarly for
 142      return values from functions.  The argument TYPE is the top of the
 143      chain, and BOTTOM is the new type which we will point to.  */
 144   tree (*reconstruct_complex_type) (tree, tree);
 145 };
 146
 147 /* Language hooks related to decls and the symbol table.  */
 148
 149 struct lang_hooks_for_decls
 150 {
 151   /* Return true if we are in the global binding level.  This hook is really
 152      needed only if the language supports variable-sized types at the global
 153      level, i.e. declared outside subprograms.  */
 154   bool (*global_bindings_p) (void);
 155
 156   /* Function to add a decl to the current scope level.  Takes one
 157      argument, a decl to add.  Returns that decl, or, if the same
 158      symbol is already declared, may return a different decl for that
 159      name.  */
 160   tree (*pushdecl) (tree);
 161
 162   /* Returns the chain of decls so far in the current scope level.  */
 163   tree (*getdecls) (void);
 164
 165   /* Returns true if DECL is explicit member function.  */
 166   bool (*function_decl_explicit_p) (tree);
 167
 168   /* Returns True if the parameter is a generic parameter decl
 169      of a generic type, e.g a template template parameter for the C++ FE.  */
 170   bool (*generic_generic_parameter_decl_p) (const_tree);
 171
 172   /* Determine if a function parameter got expanded from a
 173      function parameter pack.  */
 174   bool (*function_parm_expanded_from_pack_p) (tree, tree);
 175
 176   /* Returns the generic declaration of a generic function instantiations.  */
 177   tree (*get_generic_function_decl) (const_tree);
 178
 179   /* Returns true when we should warn for an unused global DECL.
 180      We will already have checked that it has static binding.  */
 181   bool (*warn_unused_global) (const_tree);
 182
 183   /* Obtain a list of globals and do final output on them at end
 184      of compilation */
 185   void (*final_write_globals) (void);
 186
 187   /* True if this decl may be called via a sibcall.  */
 188   bool (*ok_for_sibcall) (const_tree);
 189
 190   /* True if OpenMP should privatize what this DECL points to rather
 191      than the DECL itself.  */
 192   bool (*omp_privatize_by_reference) (const_tree);
 193
 194   /* Return sharing kind if OpenMP sharing attribute of DECL is
 195      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 196   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 197
 198   /* Return decl that should be reported for DEFAULT(NONE) failure
 199      diagnostics.  Usually the DECL passed in.  */
 200   tree (*omp_report_decl) (tree);
 201
 202   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 203      disregarded in OpenMP construct, because it is going to be
 204      remapped during OpenMP lowering.  SHARED is true if DECL
 205      is going to be shared, false if it is going to be privatized.  */
 206   bool (*omp_disregard_value_expr) (tree, bool);
 207
 208   /* Return true if DECL that is shared iff SHARED is true should
 209      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 210   bool (*omp_private_debug_clause) (tree, bool);
 211
 212   /* Return true if DECL in private clause needs
 213      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 214   bool (*omp_private_outer_ref) (tree);
 215
 216   /* Build and return code for a default constructor for DECL in
 217      response to CLAUSE.  OUTER is corresponding outer region's
 218      variable if needed.  Return NULL if nothing to be done.  */
 219   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 220
 221   /* Build and return code for a copy constructor from SRC to DST.  */
 222   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 223
 224   /* Similarly, except use an assignment operator instead.  */
 225   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 226
 227   /* Build and return code destructing DECL.  Return NULL if nothing
 228      to be done.  */
 229   tree (*omp_clause_dtor) (tree clause, tree decl);
 230
 231   /* Do language specific checking on an implicitly determined clause.  */
 232   void (*omp_finish_clause) (tree clause);
 233 };
 234
 235 /* Language hooks related to LTO serialization.  */
 236
 237 struct lang_hooks_for_lto
 238 {
 239   /* Begin a new LTO section named NAME.  */
 240   void (*begin_section) (const char *name);
 241
 242   /* Write DATA of length LEN to the currently open LTO section.  BLOCK is a
 243      pointer to the dynamically allocated memory containing DATA.  The
 244      append_data function is responsible for freeing it when it is no longer
 245      needed.  */
 246   void (*append_data) (const void *data, size_t len, void *block);
 247
 248   /* End the previously begun LTO section.  */
 249   void (*end_section) (void);
 250 };
 251
 252 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 253
 254 struct lang_hooks
 255 {
 256   /* String identifying the front end.  e.g. "GNU C++".  */
 257   const char *name;
 258
 259   /* sizeof (struct lang_identifier), so make_node () creates
 260      identifier nodes long enough for the language-specific slots.  */
 261   size_t identifier_size;
 262
 263   /* Remove any parts of the tree that are used only by the FE. */
 264   void (*free_lang_data) (tree);
 265
 266   /* Determines the size of any language-specific tcc_constant or
 267      tcc_exceptional nodes.  Since it is called from make_node, the
 268      only information available is the tree code.  Expected to die
 269      on unrecognized codes.  */
 270   size_t (*tree_size) (enum tree_code);
 271
 272   /* Return the language mask used for converting argv into a sequence
 273      of options.  */
 274   unsigned int (*option_lang_mask) (void);
 275
 276   /* Initialize variables in an options structure.  */
 277   void (*init_options_struct) (struct gcc_options *opts);
 278
 279   /* After the initialize_diagnostics hook is called, do any simple
 280      initialization needed before any calls to handle_option, other
 281      than that done by the init_options_struct hook.  */
 282   void (*init_options) (unsigned int decoded_options_count,
 283                         struct cl_decoded_option *decoded_options);
 284
 285   /* Callback used to perform language-specific initialization for the
 286      global diagnostic context structure.  */
 287   void (*initialize_diagnostics) (diagnostic_context *);
 288
 289   /* Return true if a warning should be given about option OPTION,
 290      which is for the wrong language, false if it should be quietly
 291      ignored.  */
 292   bool (*complain_wrong_lang_p) (const struct cl_option *option);
 293
 294   /* Handle the switch CODE, which has real type enum opt_code from
 295      options.h.  If the switch takes an argument, it is passed in ARG
 296      which points to permanent storage.  The handler is responsible for
 297      checking whether ARG is NULL, which indicates that no argument
 298      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 299      for the positive and negative forms respectively.  HANDLERS should
 300      be passed to any recursive handle_option calls.  LOC is the
 301      location of the option.
 302
 303      Return true if the switch is valid, false if invalid.  */
 304   bool (*handle_option) (size_t code, const char *arg, int value, int kind,
 305                          location_t loc,
 306                          const struct cl_option_handlers *handlers);
 307
 308   /* Called when all command line options have been parsed to allow
 309      further processing and initialization
 310
 311      Should return true to indicate that a compiler back-end is
 312      not required, such as with the -E option.
 313
 314      If errorcount is nonzero after this call the compiler exits
 315      immediately and the finish hook is not called.  */
 316   bool (*post_options) (const char **);
 317
 318   /* Called after post_options to initialize the front end.  Return
 319      false to indicate that no further compilation be performed, in
 320      which case the finish hook is called immediately.  */
 321   bool (*init) (void);
 322
 323   /* Called at the end of compilation, as a finalizer.  */
 324   void (*finish) (void);
 325
 326   /* Parses the entire file.  */
 327   void (*parse_file) (void);
 328
 329   /* Determines if it's ok for a function to have no noreturn attribute.  */
 330   bool (*missing_noreturn_ok_p) (tree);
 331
 332   /* Called to obtain the alias set to be used for an expression or type.
 333      Returns -1 if the language does nothing special for it.  */
 334   alias_set_type (*get_alias_set) (tree);
 335
 336   /* Function to finish handling an incomplete decl at the end of
 337      compilation.  Default hook is does nothing.  */
 338   void (*finish_incomplete_decl) (tree);
 339
 340   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 341      DECL_NODE with a newly GC-allocated copy.  */
 342   void (*dup_lang_specific_decl) (tree);
 343
 344   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 345      thing that the assembler should talk about, set
 346      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 347      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 348      assembler does not talk about it.  */
 349   void (*set_decl_assembler_name) (tree);
 350
 351   /* The front end can add its own statistics to -fmem-report with
 352      this hook.  It should output to stderr.  */
 353   void (*print_statistics) (void);
 354
 355   /* Called by print_tree when there is a tree of class tcc_exceptional
 356      that it doesn't know how to display.  */
 357   lang_print_tree_hook print_xnode;
 358
 359   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 360      and IDENTIFIER_NODE nodes.  */
 361   lang_print_tree_hook print_decl;
 362   lang_print_tree_hook print_type;
 363   lang_print_tree_hook print_identifier;
 364
 365   /* Computes the name to use to print a declaration.  DECL is the
 366      non-NULL declaration in question.  VERBOSITY determines what
 367      information will be printed: 0: DECL_NAME, demangled as
 368      necessary.  1: and scope information.  2: and any other
 369      information that might be interesting, such as function parameter
 370      types in C++.  The name is in the internal character set and
 371      needs to be converted to the locale character set of diagnostics,
 372      or to the execution character set for strings such as
 373      __PRETTY_FUNCTION__.  */
 374   const char *(*decl_printable_name) (tree decl, int verbosity);
 375
 376   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 377      information will be printed: 0: DECL_NAME, demangled as
 378      necessary.  1: and scope information.  */
 379   const char *(*dwarf_name) (tree, int verbosity);
 380
 381   /* This compares two types for equivalence ("compatible" in C-based languages).
 382      This routine should only return 1 if it is sure.  It should not be used
 383      in contexts where erroneously returning 0 causes problems.  */
 384   int (*types_compatible_p) (tree x, tree y);
 385
 386   /* Called by report_error_function to print out function name.  */
 387   void (*print_error_function) (diagnostic_context *, const char *,
 388                                 struct diagnostic_info *);
 389
 390   /* Convert a character from the host's to the target's character
 391      set.  The character should be in what C calls the "basic source
 392      character set" (roughly, the set of characters defined by plain
 393      old ASCII).  The default is to return the character unchanged,
 394      which is correct in most circumstances.  Note that both argument
 395      and result should be sign-extended under -fsigned-char,
 396      zero-extended under -fno-signed-char.  */
 397   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 398
 399   /* Pointers to machine-independent attribute tables, for front ends
 400      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 401      table of attributes specific to the language, a table of
 402      attributes common to two or more languages (to allow easy
 403      sharing), and a table of attributes for checking formats.  */
 404   const struct attribute_spec *attribute_table;
 405   const struct attribute_spec *common_attribute_table;
 406   const struct attribute_spec *format_attribute_table;
 407
 408   struct lang_hooks_for_tree_inlining tree_inlining;
 409
 410   struct lang_hooks_for_callgraph callgraph;
 411
 412   struct lang_hooks_for_tree_dump tree_dump;
 413
 414   struct lang_hooks_for_decls decls;
 415
 416   struct lang_hooks_for_types types;
 417
 418   struct lang_hooks_for_lto lto;
 419
 420   /* Returns the generic parameters of an instantiation of
 421      a generic type or decl, e.g. C++ template instantiation.  */
 422   tree (*get_innermost_generic_parms) (const_tree);
 423
 424   /* Returns the TREE_VEC of arguments of an instantiation
 425      of a generic type of decl, e.g. C++ template instantiation.  */
 426   tree (*get_innermost_generic_args) (const_tree);
 427
 428   /* Determine if a tree is a function parameter pack.  */
 429   bool (*function_parameter_pack_p) (const_tree);
 430
 431   /* Perform language-specific gimplification on the argument.  Returns an
 432      enum gimplify_status, though we can't see that type here.  */
 433   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 434
 435   /* Do language specific processing in the builtin function DECL  */
 436   tree (*builtin_function) (tree decl);
 437
 438   /* Like builtin_function, but make sure the scope is the external scope.
 439      This is used to delay putting in back end builtin functions until the ISA
 440      that defines the builtin is declared via function specific target options,
 441      which can save memory for machines like the x86_64 that have multiple
 442      ISAs.  If this points to the same function as builtin_function, the
 443      backend must add all of the builtins at program initialization time.  */
 444   tree (*builtin_function_ext_scope) (tree decl);
 445
 446   /* Used to set up the tree_contains_structure array for a frontend. */
 447   void (*init_ts) (void);
 448
 449   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 450      to a contained expression or DECL, possibly updating *TC or *SE
 451      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 452   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 453
 454   /* The EH personality function decl.  */
 455   tree (*eh_personality) (void);
 456
 457   /* Map a type to a runtime object to match type.  */
 458   tree (*eh_runtime_type) (tree);
 459
 460   /* If non-NULL, this is a function that returns a function decl to be
 461      executed if an unhandled exception is propagated out of a cleanup
 462      region.  For example, in C++, an exception thrown by a destructor
 463      during stack unwinding is required to result in a call to
 464      `std::terminate', so the C++ version of this function returns a
 465      FUNCTION_DECL for `std::terminate'.  */
 466   tree (*eh_protect_cleanup_actions) (void);
 467
 468   /* True if this language uses __cxa_end_cleanup when the ARM EABI
 469      is enabled.  */
 470   bool eh_use_cxa_end_cleanup;
 471
 472   /* True if this language requires deep unsharing of tree nodes prior to
 473      gimplification.  */
 474   bool deep_unsharing;
 475
 476   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 477      and langhooks.c accordingly.  */
 478 };
 479
 480 /* Each front end provides its own.  */
 481 extern struct lang_hooks lang_hooks;
 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
 493 #endif /* GCC_LANG_HOOKS_H */