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   /* Returns nonzero if we are in the global binding level.  Ada
 152      returns -1 for an undocumented reason used in stor-layout.c.  */
 153   int (*global_bindings_p) (void);
 154
 155   /* Function to add a decl to the current scope level.  Takes one
 156      argument, a decl to add.  Returns that decl, or, if the same
 157      symbol is already declared, may return a different decl for that
 158      name.  */
 159   tree (*pushdecl) (tree);
 160
 161   /* Returns the chain of decls so far in the current scope level.  */
 162   tree (*getdecls) (void);
 163
 164   /* Returns true if DECL is explicit member function.  */
 165   bool (*function_decl_explicit_p) (tree);
 166
 167   /* Returns True if the parameter is a generic parameter decl
 168      of a generic type, e.g a template template parameter for the C++ FE.  */
 169   bool (*generic_generic_parameter_decl_p) (const_tree);
 170
 171   /* Determine if a function parameter got expanded from a
 172      function parameter pack.  */
 173   bool (*function_parm_expanded_from_pack_p) (tree, tree);
 174
 175   /* Returns the generic declaration of a generic function instantiations.  */
 176   tree (*get_generic_function_decl) (const_tree);
 177
 178   /* Returns true when we should warn for an unused global DECL.
 179      We will already have checked that it has static binding.  */
 180   bool (*warn_unused_global) (const_tree);
 181
 182   /* Obtain a list of globals and do final output on them at end
 183      of compilation */
 184   void (*final_write_globals) (void);
 185
 186   /* True if this decl may be called via a sibcall.  */
 187   bool (*ok_for_sibcall) (const_tree);
 188
 189   /* True if OpenMP should privatize what this DECL points to rather
 190      than the DECL itself.  */
 191   bool (*omp_privatize_by_reference) (const_tree);
 192
 193   /* Return sharing kind if OpenMP sharing attribute of DECL is
 194      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 195   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 196
 197   /* Return decl that should be reported for DEFAULT(NONE) failure
 198      diagnostics.  Usually the DECL passed in.  */
 199   tree (*omp_report_decl) (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   /* Return the language mask used for converting argv into a sequence
 272      of options.  */
 273   unsigned int (*option_lang_mask) (void);
 274
 275   /* Initialize variables in an options structure.  */
 276   void (*init_options_struct) (struct gcc_options *opts);
 277
 278   /* After the initialize_diagnostics hook is called, do any simple
 279      initialization needed before any calls to handle_option, other
 280      than that done by the init_options_struct hook.  */
 281   void (*init_options) (unsigned int decoded_options_count,
 282                         struct cl_decoded_option *decoded_options);
 283
 284   /* Callback used to perform language-specific initialization for the
 285      global diagnostic context structure.  */
 286   void (*initialize_diagnostics) (diagnostic_context *);
 287
 288   /* Return true if a warning should be given about option OPTION,
 289      which is for the wrong language, false if it should be quietly
 290      ignored.  */
 291   bool (*complain_wrong_lang_p) (const struct cl_option *option);
 292
 293   /* Handle the switch CODE, which has real type enum opt_code from
 294      options.h.  If the switch takes an argument, it is passed in ARG
 295      which points to permanent storage.  The handler is responsible for
 296      checking whether ARG is NULL, which indicates that no argument
 297      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 298      for the positive and negative forms respectively.  HANDLERS should
 299      be passed to any recursive handle_option calls.  LOC is the
 300      location of the option.
 301
 302      Return true if the switch is valid, false if invalid.  */
 303   bool (*handle_option) (size_t code, const char *arg, int value, int kind,
 304                          location_t loc,
 305                          const struct cl_option_handlers *handlers);
 306
 307   /* Called when all command line options have been parsed to allow
 308      further processing and initialization
 309
 310      Should return true to indicate that a compiler back-end is
 311      not required, such as with the -E option.
 312
 313      If errorcount is nonzero after this call the compiler exits
 314      immediately and the finish hook is not called.  */
 315   bool (*post_options) (const char **);
 316
 317   /* Called after post_options to initialize the front end.  Return
 318      false to indicate that no further compilation be performed, in
 319      which case the finish hook is called immediately.  */
 320   bool (*init) (void);
 321
 322   /* Called at the end of compilation, as a finalizer.  */
 323   void (*finish) (void);
 324
 325   /* Parses the entire file.  */
 326   void (*parse_file) (void);
 327
 328   /* Determines if it's ok for a function to have no noreturn attribute.  */
 329   bool (*missing_noreturn_ok_p) (tree);
 330
 331   /* Called to obtain the alias set to be used for an expression or type.
 332      Returns -1 if the language does nothing special for it.  */
 333   alias_set_type (*get_alias_set) (tree);
 334
 335   /* Function to finish handling an incomplete decl at the end of
 336      compilation.  Default hook is does nothing.  */
 337   void (*finish_incomplete_decl) (tree);
 338
 339   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 340      DECL_NODE with a newly GC-allocated copy.  */
 341   void (*dup_lang_specific_decl) (tree);
 342
 343   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 344      thing that the assembler should talk about, set
 345      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 346      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 347      assembler does not talk about it.  */
 348   void (*set_decl_assembler_name) (tree);
 349
 350   /* The front end can add its own statistics to -fmem-report with
 351      this hook.  It should output to stderr.  */
 352   void (*print_statistics) (void);
 353
 354   /* Called by print_tree when there is a tree of class tcc_exceptional
 355      that it doesn't know how to display.  */
 356   lang_print_tree_hook print_xnode;
 357
 358   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 359      and IDENTIFIER_NODE nodes.  */
 360   lang_print_tree_hook print_decl;
 361   lang_print_tree_hook print_type;
 362   lang_print_tree_hook print_identifier;
 363
 364   /* Computes the name to use to print a declaration.  DECL is the
 365      non-NULL declaration in question.  VERBOSITY determines what
 366      information will be printed: 0: DECL_NAME, demangled as
 367      necessary.  1: and scope information.  2: and any other
 368      information that might be interesting, such as function parameter
 369      types in C++.  The name is in the internal character set and
 370      needs to be converted to the locale character set of diagnostics,
 371      or to the execution character set for strings such as
 372      __PRETTY_FUNCTION__.  */
 373   const char *(*decl_printable_name) (tree decl, int verbosity);
 374
 375   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 376      information will be printed: 0: DECL_NAME, demangled as
 377      necessary.  1: and scope information.  */
 378   const char *(*dwarf_name) (tree, int verbosity);
 379
 380   /* This compares two types for equivalence ("compatible" in C-based languages).
 381      This routine should only return 1 if it is sure.  It should not be used
 382      in contexts where erroneously returning 0 causes problems.  */
 383   int (*types_compatible_p) (tree x, tree y);
 384
 385   /* Called by report_error_function to print out function name.  */
 386   void (*print_error_function) (diagnostic_context *, const char *,
 387                                 struct diagnostic_info *);
 388
 389   /* Convert a character from the host's to the target's character
 390      set.  The character should be in what C calls the "basic source
 391      character set" (roughly, the set of characters defined by plain
 392      old ASCII).  The default is to return the character unchanged,
 393      which is correct in most circumstances.  Note that both argument
 394      and result should be sign-extended under -fsigned-char,
 395      zero-extended under -fno-signed-char.  */
 396   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 397
 398   /* Pointers to machine-independent attribute tables, for front ends
 399      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 400      table of attributes specific to the language, a table of
 401      attributes common to two or more languages (to allow easy
 402      sharing), and a table of attributes for checking formats.  */
 403   const struct attribute_spec *attribute_table;
 404   const struct attribute_spec *common_attribute_table;
 405   const struct attribute_spec *format_attribute_table;
 406
 407   struct lang_hooks_for_tree_inlining tree_inlining;
 408
 409   struct lang_hooks_for_callgraph callgraph;
 410
 411   struct lang_hooks_for_tree_dump tree_dump;
 412
 413   struct lang_hooks_for_decls decls;
 414
 415   struct lang_hooks_for_types types;
 416
 417   struct lang_hooks_for_lto lto;
 418
 419   /* Returns the generic parameters of an instantiation of
 420      a generic type or decl, e.g. C++ template instantiation.  */
 421   tree (*get_innermost_generic_parms) (const_tree);
 422
 423   /* Returns the TREE_VEC of arguments of an instantiation
 424      of a generic type of decl, e.g. C++ template instantiation.  */
 425   tree (*get_innermost_generic_args) (const_tree);
 426
 427   /* Determine if a tree is a function parameter pack.  */
 428   bool (*function_parameter_pack_p) (const_tree);
 429
 430   /* Perform language-specific gimplification on the argument.  Returns an
 431      enum gimplify_status, though we can't see that type here.  */
 432   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 433
 434   /* Do language specific processing in the builtin function DECL  */
 435   tree (*builtin_function) (tree decl);
 436
 437   /* Like builtin_function, but make sure the scope is the external scope.
 438      This is used to delay putting in back end builtin functions until the ISA
 439      that defines the builtin is declared via function specific target options,
 440      which can save memory for machines like the x86_64 that have multiple
 441      ISAs.  If this points to the same function as builtin_function, the
 442      backend must add all of the builtins at program initialization time.  */
 443   tree (*builtin_function_ext_scope) (tree decl);
 444
 445   /* Used to set up the tree_contains_structure array for a frontend. */
 446   void (*init_ts) (void);
 447
 448   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 449      to a contained expression or DECL, possibly updating *TC or *SE
 450      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 451   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 452
 453   /* The EH personality function decl.  */
 454   tree (*eh_personality) (void);
 455
 456   /* Map a type to a runtime object to match type.  */
 457   tree (*eh_runtime_type) (tree);
 458
 459   /* If non-NULL, this is a function that returns a function decl to be
 460      executed if an unhandled exception is propagated out of a cleanup
 461      region.  For example, in C++, an exception thrown by a destructor
 462      during stack unwinding is required to result in a call to
 463      `std::terminate', so the C++ version of this function returns a
 464      FUNCTION_DECL for `std::terminate'.  */
 465   tree (*eh_protect_cleanup_actions) (void);
 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   /* Used by pre-parsed header (PPH) to intercept certain tree nodes
 476      created by make_node_stat during parsing.  */
 477   void (*pph_catch_tree) (tree t);
 478   void (*pph_uncatch_tree) (tree t);
 479
 480   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 481      and langhooks.c accordingly.  */
 482 };
 483
 484 /* Each front end provides its own.  */
 485 extern struct lang_hooks lang_hooks;
 486 extern tree add_builtin_function (const char *name, tree type,
 487                                   int function_code, enum built_in_class cl,
 488                                   const char *library_name,
 489                                   tree attrs);
 490
 491 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 492                                             int function_code,
 493                                             enum built_in_class cl,
 494                                             const char *library_name,
 495                                             tree attrs);
 496
 497 #endif /* GCC_LANG_HOOKS_H */