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   /* Emit thunks associated to function.  */
  54   void (*emit_associated_thunks) (tree);
  55 };
  56
  57 /* The following hooks are used by tree-dump.c.  */
  58
  59 struct lang_hooks_for_tree_dump
  60 {
  61   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  62      does not want the usual dumping of the second argument.  */
  63   bool (*dump_tree) (void *, tree);
  64
  65   /* Determine type qualifiers in a language-specific way.  */
  66   int (*type_quals) (const_tree);
  67 };
  68
  69 /* Hooks related to types.  */
  70
  71 struct lang_hooks_for_types
  72 {
  73   /* Return a new type (with the indicated CODE), doing whatever
  74      language-specific processing is required.  */
  75   tree (*make_type) (enum tree_code);
  76
  77   /* Return what kind of RECORD_TYPE this is, mainly for purposes of
  78      debug information.  If not defined, record types are assumed to
  79      be structures.  */
  80   enum classify_record (*classify_record) (tree);
  81
  82   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  83      mode.  */
  84   tree (*type_for_mode) (enum machine_mode, int);
  85
  86   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
  87      integer type with at least that precision.  */
  88   tree (*type_for_size) (unsigned, int);
  89
  90   /* True if the type is an instantiation of a generic type,
  91      e.g. C++ template implicit specializations.  */
  92   bool (*generic_p) (const_tree);
  93
  94   /* Returns the TREE_VEC of elements of a given generic argument pack.  */
  95   tree (*get_argument_pack_elems) (const_tree);
  96
  97   /* Given a type, apply default promotions to unnamed function
  98      arguments and return the new type.  Return the same type if no
  99      change.  Required by any language that supports variadic
 100      arguments.  The default hook dies.  */
 101   tree (*type_promotes_to) (tree);
 102
 103   /* Register TYPE as a builtin type with the indicated NAME.  The
 104      TYPE is placed in the outermost lexical scope.  The semantics
 105      should be analogous to:
 106
 107        typedef TYPE NAME;
 108
 109      in C.  The default hook ignores the declaration.  */
 110   void (*register_builtin_type) (tree, const char *);
 111
 112   /* This routine is called in tree.c to print an error message for
 113      invalid use of an incomplete type.  VALUE is the expression that
 114      was used (or 0 if that isn't known) and TYPE is the type that was
 115      invalid.  */
 116   void (*incomplete_type_error) (const_tree value, const_tree type);
 117
 118   /* Called from assign_temp to return the maximum size, if there is one,
 119      for a type.  */
 120   tree (*max_size) (const_tree);
 121
 122   /* Register language specific type size variables as potentially OpenMP
 123      firstprivate variables.  */
 124   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 125
 126   /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
 127      Called only after doing all language independent checks.
 128      At present, this function is only called when both TYPE1 and TYPE2 are
 129      FUNCTION_TYPEs.  */
 130   bool (*type_hash_eq) (const_tree, const_tree);
 131
 132   /* Return TRUE if TYPE uses a hidden descriptor and fills in information
 133      for the debugger about the array bounds, strides, etc.  */
 134   bool (*get_array_descr_info) (const_tree, struct array_descr_info *);
 135
 136   /* Fill in information for the debugger about the bounds of TYPE.  */
 137   void (*get_subrange_bounds) (const_tree, tree *, tree *);
 138
 139   /* If we requested a pointer to a vector, build up the pointers that
 140      we stripped off while looking for the inner type.  Similarly for
 141      return values from functions.  The argument TYPE is the top of the
 142      chain, and BOTTOM is the new type which we will point to.  */
 143   tree (*reconstruct_complex_type) (tree, tree);
 144
 145   /* Nonzero if types that are identical are to be hashed so that only
 146      one copy is kept.  If a language requires unique types for each
 147      user-specified type, such as Ada, this should be set to TRUE.  */
 148   bool hash_types;
 149 };
 150
 151 /* Language hooks related to decls and the symbol table.  */
 152
 153 struct lang_hooks_for_decls
 154 {
 155   /* Returns nonzero if we are in the global binding level.  Ada
 156      returns -1 for an undocumented reason used in stor-layout.c.  */
 157   int (*global_bindings_p) (void);
 158
 159   /* Function to add a decl to the current scope level.  Takes one
 160      argument, a decl to add.  Returns that decl, or, if the same
 161      symbol is already declared, may return a different decl for that
 162      name.  */
 163   tree (*pushdecl) (tree);
 164
 165   /* Returns the chain of decls so far in the current scope level.  */
 166   tree (*getdecls) (void);
 167
 168   /* Returns true if DECL is explicit member function.  */
 169   bool (*function_decl_explicit_p) (tree);
 170
 171   /* Returns True if the parameter is a generic parameter decl
 172      of a generic type, e.g a template template parameter for the C++ FE.  */
 173   bool (*generic_generic_parameter_decl_p) (const_tree);
 174
 175   /* Determine if a function parameter got expanded from a
 176      function parameter pack.  */
 177   bool (*function_parm_expanded_from_pack_p) (tree, tree);
 178
 179   /* Returns the generic declaration of a generic function instantiations.  */
 180   tree (*get_generic_function_decl) (const_tree);
 181
 182   /* Returns true when we should warn for an unused global DECL.
 183      We will already have checked that it has static binding.  */
 184   bool (*warn_unused_global) (const_tree);
 185
 186   /* Obtain a list of globals and do final output on them at end
 187      of compilation */
 188   void (*final_write_globals) (void);
 189
 190   /* True if this decl may be called via a sibcall.  */
 191   bool (*ok_for_sibcall) (const_tree);
 192
 193   /* True if OpenMP should privatize what this DECL points to rather
 194      than the DECL itself.  */
 195   bool (*omp_privatize_by_reference) (const_tree);
 196
 197   /* Return sharing kind if OpenMP sharing attribute of DECL is
 198      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 199   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 200
 201   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 202      disregarded in OpenMP construct, because it is going to be
 203      remapped during OpenMP lowering.  SHARED is true if DECL
 204      is going to be shared, false if it is going to be privatized.  */
 205   bool (*omp_disregard_value_expr) (tree, bool);
 206
 207   /* Return true if DECL that is shared iff SHARED is true should
 208      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 209   bool (*omp_private_debug_clause) (tree, bool);
 210
 211   /* Return true if DECL in private clause needs
 212      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 213   bool (*omp_private_outer_ref) (tree);
 214
 215   /* Build and return code for a default constructor for DECL in
 216      response to CLAUSE.  OUTER is corresponding outer region's
 217      variable if needed.  Return NULL if nothing to be done.  */
 218   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 219
 220   /* Build and return code for a copy constructor from SRC to DST.  */
 221   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 222
 223   /* Similarly, except use an assignment operator instead.  */
 224   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 225
 226   /* Build and return code destructing DECL.  Return NULL if nothing
 227      to be done.  */
 228   tree (*omp_clause_dtor) (tree clause, tree decl);
 229
 230   /* Do language specific checking on an implicitly determined clause.  */
 231   void (*omp_finish_clause) (tree clause);
 232 };
 233
 234 /* Language hooks related to LTO serialization.  */
 235
 236 struct lang_hooks_for_lto
 237 {
 238   /* Begin a new LTO section named NAME.  */
 239   void (*begin_section) (const char *name);
 240
 241   /* Write DATA of length LEN to the currently open LTO section.  BLOCK is a
 242      pointer to the dynamically allocated memory containing DATA.  The
 243      append_data function is responsible for freeing it when it is no longer
 244      needed.  */
 245   void (*append_data) (const void *data, size_t len, void *block);
 246
 247   /* End the previously begun LTO section.  */
 248   void (*end_section) (void);
 249 };
 250
 251 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 252
 253 struct lang_hooks
 254 {
 255   /* String identifying the front end.  e.g. "GNU C++".  */
 256   const char *name;
 257
 258   /* sizeof (struct lang_identifier), so make_node () creates
 259      identifier nodes long enough for the language-specific slots.  */
 260   size_t identifier_size;
 261
 262   /* Remove any parts of the tree that are used only by the FE. */
 263   void (*free_lang_data) (tree);
 264
 265   /* Determines the size of any language-specific tcc_constant or
 266      tcc_exceptional nodes.  Since it is called from make_node, the
 267      only information available is the tree code.  Expected to die
 268      on unrecognized codes.  */
 269   size_t (*tree_size) (enum tree_code);
 270
 271   /* The first callback made to the front end, for simple
 272      initialization needed before any calls to handle_option.  Return
 273      the language mask to filter the switch array with.  */
 274   unsigned int (*init_options) (unsigned int argc, const char **argv);
 275
 276   /* Callback used to perform language-specific initialization for the
 277      global diagnostic context structure.  */
 278   void (*initialize_diagnostics) (struct diagnostic_context *);
 279
 280   /* Handle the switch CODE, which has real type enum opt_code from
 281      options.h.  If the switch takes an argument, it is passed in ARG
 282      which points to permanent storage.  The handler is responsible for
 283      checking whether ARG is NULL, which indicates that no argument
 284      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 285      for the positive and negative forms respectively.
 286
 287      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 288      valid and should not be treated as language-independent too.  */
 289   int (*handle_option) (size_t code, const char *arg, int value);
 290
 291   /* Return false to use the default complaint about a missing
 292      argument, otherwise output a complaint and return true.  */
 293   bool (*missing_argument) (const char *opt, size_t code);
 294
 295   /* Called when all command line options have been parsed to allow
 296      further processing and initialization
 297
 298      Should return true to indicate that a compiler back-end is
 299      not required, such as with the -E option.
 300
 301      If errorcount is nonzero after this call the compiler exits
 302      immediately and the finish hook is not called.  */
 303   bool (*post_options) (const char **);
 304
 305   /* Called after post_options to initialize the front end.  Return
 306      false to indicate that no further compilation be performed, in
 307      which case the finish hook is called immediately.  */
 308   bool (*init) (void);
 309
 310   /* Called at the end of compilation, as a finalizer.  */
 311   void (*finish) (void);
 312
 313   /* Parses the entire file.  The argument is nonzero to cause bison
 314      parsers to dump debugging information during parsing.  */
 315   void (*parse_file) (int);
 316
 317   /* Determines if it's ok for a function to have no noreturn attribute.  */
 318   bool (*missing_noreturn_ok_p) (tree);
 319
 320   /* Called to obtain the alias set to be used for an expression or type.
 321      Returns -1 if the language does nothing special for it.  */
 322   alias_set_type (*get_alias_set) (tree);
 323
 324   /* Function to finish handling an incomplete decl at the end of
 325      compilation.  Default hook is does nothing.  */
 326   void (*finish_incomplete_decl) (tree);
 327
 328   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 329      DECL_NODE with a newly GC-allocated copy.  */
 330   void (*dup_lang_specific_decl) (tree);
 331
 332   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 333      thing that the assembler should talk about, set
 334      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 335      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 336      assembler does not talk about it.  */
 337   void (*set_decl_assembler_name) (tree);
 338
 339   /* The front end can add its own statistics to -fmem-report with
 340      this hook.  It should output to stderr.  */
 341   void (*print_statistics) (void);
 342
 343   /* Called by print_tree when there is a tree of class tcc_exceptional
 344      that it doesn't know how to display.  */
 345   lang_print_tree_hook print_xnode;
 346
 347   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 348      and IDENTIFIER_NODE nodes.  */
 349   lang_print_tree_hook print_decl;
 350   lang_print_tree_hook print_type;
 351   lang_print_tree_hook print_identifier;
 352
 353   /* Computes the name to use to print a declaration.  DECL is the
 354      non-NULL declaration in question.  VERBOSITY determines what
 355      information will be printed: 0: DECL_NAME, demangled as
 356      necessary.  1: and scope information.  2: and any other
 357      information that might be interesting, such as function parameter
 358      types in C++.  The name is in the internal character set and
 359      needs to be converted to the locale character set of diagnostics,
 360      or to the execution character set for strings such as
 361      __PRETTY_FUNCTION__.  */
 362   const char *(*decl_printable_name) (tree decl, int verbosity);
 363
 364   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 365      information will be printed: 0: DECL_NAME, demangled as
 366      necessary.  1: and scope information.  */
 367   const char *(*dwarf_name) (tree, int verbosity);
 368
 369   /* This compares two types for equivalence ("compatible" in C-based languages).
 370      This routine should only return 1 if it is sure.  It should not be used
 371      in contexts where erroneously returning 0 causes problems.  */
 372   int (*types_compatible_p) (tree x, tree y);
 373
 374   /* Called by report_error_function to print out function name.  */
 375   void (*print_error_function) (struct diagnostic_context *, const char *,
 376                                 struct diagnostic_info *);
 377
 378   /* Convert a character from the host's to the target's character
 379      set.  The character should be in what C calls the "basic source
 380      character set" (roughly, the set of characters defined by plain
 381      old ASCII).  The default is to return the character unchanged,
 382      which is correct in most circumstances.  Note that both argument
 383      and result should be sign-extended under -fsigned-char,
 384      zero-extended under -fno-signed-char.  */
 385   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 386
 387   /* Pointers to machine-independent attribute tables, for front ends
 388      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 389      table of attributes specific to the language, a table of
 390      attributes common to two or more languages (to allow easy
 391      sharing), and a table of attributes for checking formats.  */
 392   const struct attribute_spec *attribute_table;
 393   const struct attribute_spec *common_attribute_table;
 394   const struct attribute_spec *format_attribute_table;
 395
 396   struct lang_hooks_for_tree_inlining tree_inlining;
 397
 398   struct lang_hooks_for_callgraph callgraph;
 399
 400   struct lang_hooks_for_tree_dump tree_dump;
 401
 402   struct lang_hooks_for_decls decls;
 403
 404   struct lang_hooks_for_types types;
 405
 406   struct lang_hooks_for_lto lto;
 407
 408   /* Returns the generic parameters of an instantiation of
 409      a generic type or decl, e.g. C++ template instantiation.  */
 410   tree (*get_innermost_generic_parms) (const_tree);
 411
 412   /* Returns the TREE_VEC of arguments of an instantiation
 413      of a generic type of decl, e.g. C++ template instantiation.  */
 414   tree (*get_innermost_generic_args) (const_tree);
 415
 416   /* Determine if a tree is a function parameter pack.  */
 417   bool (*function_parameter_pack_p) (const_tree);
 418
 419   /* Perform language-specific gimplification on the argument.  Returns an
 420      enum gimplify_status, though we can't see that type here.  */
 421   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 422
 423   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 424      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 425   tree (*fold_obj_type_ref) (tree, tree);
 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   /* True if this language uses __cxa_end_cleanup when the ARM EABI
 453      is enabled.  */
 454   bool eh_use_cxa_end_cleanup;
 455
 456   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 457      and langhooks.c accordingly.  */
 458 };
 459
 460 /* Each front end provides its own.  */
 461 extern struct lang_hooks lang_hooks;
 462 extern tree add_builtin_function (const char *name, tree type,
 463                                   int function_code, enum built_in_class cl,
 464                                   const char *library_name,
 465                                   tree attrs);
 466
 467 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 468                                             int function_code,
 469                                             enum built_in_class cl,
 470                                             const char *library_name,
 471                                             tree attrs);
 472
 473 #endif /* GCC_LANG_HOOKS_H */