gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
   3    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_context;
  27 struct diagnostic_info;
  28
  29 struct gimplify_omp_ctx;
  30
  31 struct array_descr_info;
  32
  33 /* A print hook for print_tree ().  */
  34 typedef void (*lang_print_tree_hook) (FILE *, tree, int indent);
  35
  36 enum classify_record
  37   { RECORD_IS_STRUCT, RECORD_IS_CLASS, RECORD_IS_INTERFACE };
  38
  39 /* The following hooks are documented in langhooks.c.  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 struct lang_hooks_for_callgraph
  48 {
  49   /* The node passed is a language-specific tree node.  If its contents
  50      are relevant to use of other declarations, mark them.  */
  51   tree (*analyze_expr) (tree *, int *);
  52 };
  53
  54 /* The following hooks are used by tree-dump.c.  */
  55
  56 struct lang_hooks_for_tree_dump
  57 {
  58   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  59      does not want the usual dumping of the second argument.  */
  60   bool (*dump_tree) (void *, tree);
  61
  62   /* Determine type qualifiers in a language-specific way.  */
  63   int (*type_quals) (const_tree);
  64 };
  65
  66 /* Hooks related to types.  */
  67
  68 struct lang_hooks_for_types
  69 {
  70   /* Return a new type (with the indicated CODE), doing whatever
  71      language-specific processing is required.  */
  72   tree (*make_type) (enum tree_code);
  73
  74   /* Return what kind of RECORD_TYPE this is, mainly for purposes of
  75      debug information.  If not defined, record types are assumed to
  76      be structures.  */
  77   enum classify_record (*classify_record) (tree);
  78
  79   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  80      mode.  */
  81   tree (*type_for_mode) (enum machine_mode, int);
  82
  83   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
  84      integer type with at least that precision.  */
  85   tree (*type_for_size) (unsigned, int);
  86
  87   /* True if the type is an instantiation of a generic type,
  88      e.g. C++ template implicit specializations.  */
  89   bool (*generic_p) (const_tree);
  90
  91   /* Returns the TREE_VEC of elements of a given generic argument pack.  */
  92   tree (*get_argument_pack_elems) (const_tree);
  93
  94   /* Given a type, apply default promotions to unnamed function
  95      arguments and return the new type.  Return the same type if no
  96      change.  Required by any language that supports variadic
  97      arguments.  The default hook dies.  */
  98   tree (*type_promotes_to) (tree);
  99
 100   /* Register TYPE as a builtin type with the indicated NAME.  The
 101      TYPE is placed in the outermost lexical scope.  The semantics
 102      should be analogous to:
 103
 104        typedef TYPE NAME;
 105
 106      in C.  The default hook ignores the declaration.  */
 107   void (*register_builtin_type) (tree, const char *);
 108
 109   /* This routine is called in tree.c to print an error message for
 110      invalid use of an incomplete type.  VALUE is the expression that
 111      was used (or 0 if that isn't known) and TYPE is the type that was
 112      invalid.  */
 113   void (*incomplete_type_error) (const_tree value, const_tree type);
 114
 115   /* Called from assign_temp to return the maximum size, if there is one,
 116      for a type.  */
 117   tree (*max_size) (const_tree);
 118
 119   /* Register language specific type size variables as potentially OpenMP
 120      firstprivate variables.  */
 121   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 122
 123   /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
 124      Called only after doing all language independent checks.
 125      At present, this function is only called when both TYPE1 and TYPE2 are
 126      FUNCTION_TYPEs.  */
 127   bool (*type_hash_eq) (const_tree, const_tree);
 128
 129   /* Return TRUE if TYPE uses a hidden descriptor and fills in information
 130      for the debugger about the array bounds, strides, etc.  */
 131   bool (*get_array_descr_info) (const_tree, struct array_descr_info *);
 132
 133   /* Fill in information for the debugger about the bounds of TYPE.  */
 134   void (*get_subrange_bounds) (const_tree, tree *, tree *);
 135
 136   /* If we requested a pointer to a vector, build up the pointers that
 137      we stripped off while looking for the inner type.  Similarly for
 138      return values from functions.  The argument TYPE is the top of the
 139      chain, and BOTTOM is the new type which we will point to.  */
 140   tree (*reconstruct_complex_type) (tree, tree);
 141
 142   /* Nonzero if types that are identical are to be hashed so that only
 143      one copy is kept.  If a language requires unique types for each
 144      user-specified type, such as Ada, this should be set to TRUE.  */
 145   bool hash_types;
 146 };
 147
 148 /* Language hooks related to decls and the symbol table.  */
 149
 150 struct lang_hooks_for_decls
 151 {
 152   /* Returns nonzero if we are in the global binding level.  Ada
 153      returns -1 for an undocumented reason used in stor-layout.c.  */
 154   int (*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   /* The first callback made to the front end, for simple
 273      initialization needed before any calls to handle_option.  Return
 274      the language mask to filter the switch array with.  */
 275   unsigned int (*init_options) (unsigned int argc, const char **argv);
 276
 277   /* Callback used to perform language-specific initialization for the
 278      global diagnostic context structure.  */
 279   void (*initialize_diagnostics) (struct diagnostic_context *);
 280
 281   /* Handle the switch CODE, which has real type enum opt_code from
 282      options.h.  If the switch takes an argument, it is passed in ARG
 283      which points to permanent storage.  The handler is responsible for
 284      checking whether ARG is NULL, which indicates that no argument
 285      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 286      for the positive and negative forms respectively.
 287
 288      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 289      valid and should not be treated as language-independent too.  */
 290   int (*handle_option) (size_t code, const char *arg, int value, int kind);
 291
 292   /* Return false to use the default complaint about a missing
 293      argument, otherwise output a complaint and return true.  */
 294   bool (*missing_argument) (const char *opt, size_t code);
 295
 296   /* Called when all command line options have been parsed to allow
 297      further processing and initialization
 298
 299      Should return true to indicate that a compiler back-end is
 300      not required, such as with the -E option.
 301
 302      If errorcount is nonzero after this call the compiler exits
 303      immediately and the finish hook is not called.  */
 304   bool (*post_options) (const char **);
 305
 306   /* Called after post_options to initialize the front end.  Return
 307      false to indicate that no further compilation be performed, in
 308      which case the finish hook is called immediately.  */
 309   bool (*init) (void);
 310
 311   /* Called at the end of compilation, as a finalizer.  */
 312   void (*finish) (void);
 313
 314   /* Parses the entire file.  The argument is nonzero to cause bison
 315      parsers to dump debugging information during parsing.  */
 316   void (*parse_file) (int);
 317
 318   /* Determines if it's ok for a function to have no noreturn attribute.  */
 319   bool (*missing_noreturn_ok_p) (tree);
 320
 321   /* Called to obtain the alias set to be used for an expression or type.
 322      Returns -1 if the language does nothing special for it.  */
 323   alias_set_type (*get_alias_set) (tree);
 324
 325   /* Function to finish handling an incomplete decl at the end of
 326      compilation.  Default hook is does nothing.  */
 327   void (*finish_incomplete_decl) (tree);
 328
 329   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 330      DECL_NODE with a newly GC-allocated copy.  */
 331   void (*dup_lang_specific_decl) (tree);
 332
 333   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 334      thing that the assembler should talk about, set
 335      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 336      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 337      assembler does not talk about it.  */
 338   void (*set_decl_assembler_name) (tree);
 339
 340   /* The front end can add its own statistics to -fmem-report with
 341      this hook.  It should output to stderr.  */
 342   void (*print_statistics) (void);
 343
 344   /* Called by print_tree when there is a tree of class tcc_exceptional
 345      that it doesn't know how to display.  */
 346   lang_print_tree_hook print_xnode;
 347
 348   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 349      and IDENTIFIER_NODE nodes.  */
 350   lang_print_tree_hook print_decl;
 351   lang_print_tree_hook print_type;
 352   lang_print_tree_hook print_identifier;
 353
 354   /* Computes the name to use to print a declaration.  DECL is the
 355      non-NULL declaration in question.  VERBOSITY determines what
 356      information will be printed: 0: DECL_NAME, demangled as
 357      necessary.  1: and scope information.  2: and any other
 358      information that might be interesting, such as function parameter
 359      types in C++.  The name is in the internal character set and
 360      needs to be converted to the locale character set of diagnostics,
 361      or to the execution character set for strings such as
 362      __PRETTY_FUNCTION__.  */
 363   const char *(*decl_printable_name) (tree decl, int verbosity);
 364
 365   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 366      information will be printed: 0: DECL_NAME, demangled as
 367      necessary.  1: and scope information.  */
 368   const char *(*dwarf_name) (tree, int verbosity);
 369
 370   /* This compares two types for equivalence ("compatible" in C-based languages).
 371      This routine should only return 1 if it is sure.  It should not be used
 372      in contexts where erroneously returning 0 causes problems.  */
 373   int (*types_compatible_p) (tree x, tree y);
 374
 375   /* Called by report_error_function to print out function name.  */
 376   void (*print_error_function) (struct diagnostic_context *, const char *,
 377                                 struct diagnostic_info *);
 378
 379   /* Convert a character from the host's to the target's character
 380      set.  The character should be in what C calls the "basic source
 381      character set" (roughly, the set of characters defined by plain
 382      old ASCII).  The default is to return the character unchanged,
 383      which is correct in most circumstances.  Note that both argument
 384      and result should be sign-extended under -fsigned-char,
 385      zero-extended under -fno-signed-char.  */
 386   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 387
 388   /* Pointers to machine-independent attribute tables, for front ends
 389      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 390      table of attributes specific to the language, a table of
 391      attributes common to two or more languages (to allow easy
 392      sharing), and a table of attributes for checking formats.  */
 393   const struct attribute_spec *attribute_table;
 394   const struct attribute_spec *common_attribute_table;
 395   const struct attribute_spec *format_attribute_table;
 396
 397   struct lang_hooks_for_tree_inlining tree_inlining;
 398
 399   struct lang_hooks_for_callgraph callgraph;
 400
 401   struct lang_hooks_for_tree_dump tree_dump;
 402
 403   struct lang_hooks_for_decls decls;
 404
 405   struct lang_hooks_for_types types;
 406
 407   struct lang_hooks_for_lto lto;
 408
 409   /* Returns the generic parameters of an instantiation of
 410      a generic type or decl, e.g. C++ template instantiation.  */
 411   tree (*get_innermost_generic_parms) (const_tree);
 412
 413   /* Returns the TREE_VEC of arguments of an instantiation
 414      of a generic type of decl, e.g. C++ template instantiation.  */
 415   tree (*get_innermost_generic_args) (const_tree);
 416
 417   /* Determine if a tree is a function parameter pack.  */
 418   bool (*function_parameter_pack_p) (const_tree);
 419
 420   /* Perform language-specific gimplification on the argument.  Returns an
 421      enum gimplify_status, though we can't see that type here.  */
 422   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 423
 424   /* Do language specific processing in the builtin function DECL  */
 425   tree (*builtin_function) (tree decl);
 426
 427   /* Like builtin_function, but make sure the scope is the external scope.
 428      This is used to delay putting in back end builtin functions until the ISA
 429      that defines the builtin is declared via function specific target options,
 430      which can save memory for machines like the x86_64 that have multiple
 431      ISAs.  If this points to the same function as builtin_function, the
 432      backend must add all of the builtins at program initialization time.  */
 433   tree (*builtin_function_ext_scope) (tree decl);
 434
 435   /* Used to set up the tree_contains_structure array for a frontend. */
 436   void (*init_ts) (void);
 437
 438   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 439      to a contained expression or DECL, possibly updating *TC or *SE
 440      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 441   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 442
 443   /* The EH personality function decl.  */
 444   tree (*eh_personality) (void);
 445
 446   /* Map a type to a runtime object to match type.  */
 447   tree (*eh_runtime_type) (tree);
 448
 449   /* If non-NULL, this is a function that returns a function decl to be
 450      executed if an unhandled exception is propagated out of a cleanup
 451      region.  For example, in C++, an exception thrown by a destructor
 452      during stack unwinding is required to result in a call to
 453      `std::terminate', so the C++ version of this function returns a
 454      FUNCTION_DECL for `std::terminate'.  */
 455   tree (*eh_protect_cleanup_actions) (void);
 456
 457   /* True if this language uses __cxa_end_cleanup when the ARM EABI
 458      is enabled.  */
 459   bool eh_use_cxa_end_cleanup;
 460
 461   /* True if this language requires deep unsharing of tree nodes prior to
 462      gimplification.  */
 463   bool deep_unsharing;
 464
 465   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 466      and langhooks.c accordingly.  */
 467 };
 468
 469 /* Each front end provides its own.  */
 470 extern struct lang_hooks lang_hooks;
 471 extern tree add_builtin_function (const char *name, tree type,
 472                                   int function_code, enum built_in_class cl,
 473                                   const char *library_name,
 474                                   tree attrs);
 475
 476 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 477                                             int function_code,
 478                                             enum built_in_class cl,
 479                                             const char *library_name,
 480                                             tree attrs);
 481
 482 #endif /* GCC_LANG_HOOKS_H */