gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright (C) 2001-2014 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 TYPE is a mappable type.  */
 115   bool (*omp_mappable_type) (tree type);
 116
 117   /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
 118      Called only after doing all language independent checks.
 119      At present, this function is only called when both TYPE1 and TYPE2 are
 120      FUNCTION_TYPEs.  */
 121   bool (*type_hash_eq) (const_tree, const_tree);
 122
 123   /* Return TRUE if TYPE uses a hidden descriptor and fills in information
 124      for the debugger about the array bounds, strides, etc.  */
 125   bool (*get_array_descr_info) (const_tree, struct array_descr_info *);
 126
 127   /* Fill in information for the debugger about the bounds of TYPE.  */
 128   void (*get_subrange_bounds) (const_tree, tree *, tree *);
 129
 130   /* A type descriptive of TYPE's complex layout generated to help the
 131      debugger to decode variable-length or self-referential constructs.
 132      This is only used for the AT_GNAT_descriptive_type DWARF attribute.  */
 133   tree (*descriptive_type) (const_tree);
 134
 135   /* If we requested a pointer to a vector, build up the pointers that
 136      we stripped off while looking for the inner type.  Similarly for
 137      return values from functions.  The argument TYPE is the top of the
 138      chain, and BOTTOM is the new type which we will point to.  */
 139   tree (*reconstruct_complex_type) (tree, tree);
 140 };
 141
 142 /* Language hooks related to decls and the symbol table.  */
 143
 144 struct lang_hooks_for_decls
 145 {
 146   /* Return true if we are in the global binding level.  This hook is really
 147      needed only if the language supports variable-sized types at the global
 148      level, i.e. declared outside subprograms.  */
 149   bool (*global_bindings_p) (void);
 150
 151   /* Function to add a decl to the current scope level.  Takes one
 152      argument, a decl to add.  Returns that decl, or, if the same
 153      symbol is already declared, may return a different decl for that
 154      name.  */
 155   tree (*pushdecl) (tree);
 156
 157   /* Returns the chain of decls so far in the current scope level.  */
 158   tree (*getdecls) (void);
 159
 160   /* Returns true if DECL is explicit member function.  */
 161   bool (*function_decl_explicit_p) (tree);
 162
 163   /* Returns True if the parameter is a generic parameter decl
 164      of a generic type, e.g a template template parameter for the C++ FE.  */
 165   bool (*generic_generic_parameter_decl_p) (const_tree);
 166
 167   /* Determine if a function parameter got expanded from a
 168      function parameter pack.  */
 169   bool (*function_parm_expanded_from_pack_p) (tree, tree);
 170
 171   /* Returns the generic declaration of a generic function instantiations.  */
 172   tree (*get_generic_function_decl) (const_tree);
 173
 174   /* Returns true when we should warn for an unused global DECL.
 175      We will already have checked that it has static binding.  */
 176   bool (*warn_unused_global) (const_tree);
 177
 178   /* Obtain a list of globals and do final output on them at end
 179      of compilation */
 180   void (*final_write_globals) (void);
 181
 182   /* True if this decl may be called via a sibcall.  */
 183   bool (*ok_for_sibcall) (const_tree);
 184
 185   /* True if OpenMP should privatize what this DECL points to rather
 186      than the DECL itself.  */
 187   bool (*omp_privatize_by_reference) (const_tree);
 188
 189   /* Return sharing kind if OpenMP sharing attribute of DECL is
 190      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 191   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 192
 193   /* Return decl that should be reported for DEFAULT(NONE) failure
 194      diagnostics.  Usually the DECL passed in.  */
 195   tree (*omp_report_decl) (tree);
 196
 197   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 198      disregarded in OpenMP construct, because it is going to be
 199      remapped during OpenMP lowering.  SHARED is true if DECL
 200      is going to be shared, false if it is going to be privatized.  */
 201   bool (*omp_disregard_value_expr) (tree, bool);
 202
 203   /* Return true if DECL that is shared iff SHARED is true should
 204      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 205   bool (*omp_private_debug_clause) (tree, bool);
 206
 207   /* Return true if DECL in private clause needs
 208      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 209   bool (*omp_private_outer_ref) (tree);
 210
 211   /* Build and return code for a default constructor for DECL in
 212      response to CLAUSE.  OUTER is corresponding outer region's
 213      variable if needed.  Return NULL if nothing to be done.  */
 214   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 215
 216   /* Build and return code for a copy constructor from SRC to DST.  */
 217   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 218
 219   /* Similarly, except use an assignment operator instead.  */
 220   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 221
 222   /* Build and return code destructing DECL.  Return NULL if nothing
 223      to be done.  */
 224   tree (*omp_clause_dtor) (tree clause, tree decl);
 225
 226   /* Do language specific checking on an implicitly determined clause.  */
 227   void (*omp_finish_clause) (tree clause);
 228
 229   /* Return true if language-specific layout is needed.  */
 230   bool (*layout_decl_p) (tree decl, tree type);
 231
 232   /* Perform language-specific layout.
 233      (Should be called only if the layout_decl_p hook is ture.)  */
 234   void (*layout_decl) (tree decl, tree type);
 235 };
 236
 237 /* Language hooks related to LTO serialization.  */
 238
 239 struct lang_hooks_for_lto
 240 {
 241   /* Begin a new LTO section named NAME.  */
 242   void (*begin_section) (const char *name);
 243
 244   /* Write DATA of length LEN to the currently open LTO section.  BLOCK is a
 245      pointer to the dynamically allocated memory containing DATA.  The
 246      append_data function is responsible for freeing it when it is no longer
 247      needed.  */
 248   void (*append_data) (const void *data, size_t len, void *block);
 249
 250   /* End the previously begun LTO section.  */
 251   void (*end_section) (void);
 252 };
 253
 254 /* Language hooks related to UPC.  */
 255
 256 struct lang_hooks_for_upc
 257 {
 258
 259   /* Enable/Disable UPC keywords.  */
 260   void (*toggle_keywords) (bool);
 261
 262   /* For UPC pointers-to-shared that are represented using
 263      a 'struct', declare and define the PTS representation type.  */
 264   void (*pts_struct_init_type) (void);
 265
 266   /* Build a function that will be called by the UPC runtime
 267      to initialize UPC shared variables.  */
 268   void (*build_init_func) (tree);
 269 };
 270
 271 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 272
 273 struct lang_hooks
 274 {
 275   /* String identifying the front end.  e.g. "GNU C++".  */
 276   const char *name;
 277
 278   /* sizeof (struct lang_identifier), so make_node () creates
 279      identifier nodes long enough for the language-specific slots.  */
 280   size_t identifier_size;
 281
 282   /* Remove any parts of the tree that are used only by the FE. */
 283   void (*free_lang_data) (tree);
 284
 285   /* Determines the size of any language-specific tcc_constant or
 286      tcc_exceptional nodes.  Since it is called from make_node, the
 287      only information available is the tree code.  Expected to die
 288      on unrecognized codes.  */
 289   size_t (*tree_size) (enum tree_code);
 290
 291   /* Return the language mask used for converting argv into a sequence
 292      of options.  */
 293   unsigned int (*option_lang_mask) (void);
 294
 295   /* Initialize variables in an options structure.  */
 296   void (*init_options_struct) (struct gcc_options *opts);
 297
 298   /* After the initialize_diagnostics hook is called, do any simple
 299      initialization needed before any calls to handle_option, other
 300      than that done by the init_options_struct hook.  */
 301   void (*init_options) (unsigned int decoded_options_count,
 302                         struct cl_decoded_option *decoded_options);
 303
 304   /* Callback used to perform language-specific initialization for the
 305      global diagnostic context structure.  */
 306   void (*initialize_diagnostics) (diagnostic_context *);
 307
 308   /* Return true if a warning should be given about option OPTION,
 309      which is for the wrong language, false if it should be quietly
 310      ignored.  */
 311   bool (*complain_wrong_lang_p) (const struct cl_option *option);
 312
 313   /* Handle the switch CODE, which has real type enum opt_code from
 314      options.h.  If the switch takes an argument, it is passed in ARG
 315      which points to permanent storage.  The handler is responsible for
 316      checking whether ARG is NULL, which indicates that no argument
 317      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 318      for the positive and negative forms respectively.  HANDLERS should
 319      be passed to any recursive handle_option calls.  LOC is the
 320      location of the option.
 321
 322      Return true if the switch is valid, false if invalid.  */
 323   bool (*handle_option) (size_t code, const char *arg, int value, int kind,
 324                          location_t loc,
 325                          const struct cl_option_handlers *handlers);
 326
 327   /* Called when all command line options have been parsed to allow
 328      further processing and initialization
 329
 330      Should return true to indicate that a compiler back-end is
 331      not required, such as with the -E option.
 332
 333      If errorcount is nonzero after this call the compiler exits
 334      immediately and the finish hook is not called.  */
 335   bool (*post_options) (const char **);
 336
 337   /* Called after post_options to initialize the front end.  Return
 338      false to indicate that no further compilation be performed, in
 339      which case the finish hook is called immediately.  */
 340   bool (*init) (void);
 341
 342   /* Called at the end of compilation, as a finalizer.  */
 343   void (*finish) (void);
 344
 345   /* Parses the entire file.  */
 346   void (*parse_file) (void);
 347
 348   /* Determines if it's ok for a function to have no noreturn attribute.  */
 349   bool (*missing_noreturn_ok_p) (tree);
 350
 351   /* Called to obtain the alias set to be used for an expression or type.
 352      Returns -1 if the language does nothing special for it.  */
 353   alias_set_type (*get_alias_set) (tree);
 354
 355   /* Function to finish handling an incomplete decl at the end of
 356      compilation.  Default hook is does nothing.  */
 357   void (*finish_incomplete_decl) (tree);
 358
 359   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 360      DECL_NODE with a newly GC-allocated copy.  */
 361   void (*dup_lang_specific_decl) (tree);
 362
 363   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 364      thing that the assembler should talk about, set
 365      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 366      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 367      assembler does not talk about it.  */
 368   void (*set_decl_assembler_name) (tree);
 369
 370   /* The front end can add its own statistics to -fmem-report with
 371      this hook.  It should output to stderr.  */
 372   void (*print_statistics) (void);
 373
 374   /* Called by print_tree when there is a tree of class tcc_exceptional
 375      that it doesn't know how to display.  */
 376   lang_print_tree_hook print_xnode;
 377
 378   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 379      and IDENTIFIER_NODE nodes.  */
 380   lang_print_tree_hook print_decl;
 381   lang_print_tree_hook print_type;
 382   lang_print_tree_hook print_identifier;
 383
 384   /* Computes the name to use to print a declaration.  DECL is the
 385      non-NULL declaration in question.  VERBOSITY determines what
 386      information will be printed: 0: DECL_NAME, demangled as
 387      necessary.  1: and scope information.  2: and any other
 388      information that might be interesting, such as function parameter
 389      types in C++.  The name is in the internal character set and
 390      needs to be converted to the locale character set of diagnostics,
 391      or to the execution character set for strings such as
 392      __PRETTY_FUNCTION__.  */
 393   const char *(*decl_printable_name) (tree decl, int verbosity);
 394
 395   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 396      information will be printed: 0: DECL_NAME, demangled as
 397      necessary.  1: and scope information.  */
 398   const char *(*dwarf_name) (tree, int verbosity);
 399
 400   /* This compares two types for equivalence ("compatible" in C-based languages).
 401      This routine should only return 1 if it is sure.  It should not be used
 402      in contexts where erroneously returning 0 causes problems.  */
 403   int (*types_compatible_p) (tree x, tree y);
 404
 405   /* Called by report_error_function to print out function name.  */
 406   void (*print_error_function) (diagnostic_context *, const char *,
 407                                 struct diagnostic_info *);
 408
 409   /* Convert a character from the host's to the target's character
 410      set.  The character should be in what C calls the "basic source
 411      character set" (roughly, the set of characters defined by plain
 412      old ASCII).  The default is to return the character unchanged,
 413      which is correct in most circumstances.  Note that both argument
 414      and result should be sign-extended under -fsigned-char,
 415      zero-extended under -fno-signed-char.  */
 416   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 417
 418   /* Pointers to machine-independent attribute tables, for front ends
 419      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 420      table of attributes specific to the language, a table of
 421      attributes common to two or more languages (to allow easy
 422      sharing), and a table of attributes for checking formats.  */
 423   const struct attribute_spec *attribute_table;
 424   const struct attribute_spec *common_attribute_table;
 425   const struct attribute_spec *format_attribute_table;
 426
 427   struct lang_hooks_for_tree_inlining tree_inlining;
 428
 429   struct lang_hooks_for_tree_dump tree_dump;
 430
 431   struct lang_hooks_for_decls decls;
 432
 433   struct lang_hooks_for_types types;
 434
 435   struct lang_hooks_for_lto lto;
 436
 437   struct lang_hooks_for_upc upc;
 438
 439   /* Returns a TREE_VEC of the generic parameters of an instantiation of
 440      a generic type or decl, e.g. C++ template instantiation.  If
 441      TREE_CHAIN of the return value is set, it is an INTEGER_CST
 442      indicating how many of the elements are non-default.  */
 443   tree (*get_innermost_generic_parms) (const_tree);
 444
 445   /* Returns the TREE_VEC of arguments of an instantiation
 446      of a generic type of decl, e.g. C++ template instantiation.  */
 447   tree (*get_innermost_generic_args) (const_tree);
 448
 449   /* Determine if a tree is a function parameter pack.  */
 450   bool (*function_parameter_pack_p) (const_tree);
 451
 452   /* Perform language-specific gimplification on the argument.  Returns an
 453      enum gimplify_status, though we can't see that type here.  */
 454   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 455
 456   /* Do language specific processing in the builtin function DECL  */
 457   tree (*builtin_function) (tree decl);
 458
 459   /* Like builtin_function, but make sure the scope is the external scope.
 460      This is used to delay putting in back end builtin functions until the ISA
 461      that defines the builtin is declared via function specific target options,
 462      which can save memory for machines like the x86_64 that have multiple
 463      ISAs.  If this points to the same function as builtin_function, the
 464      backend must add all of the builtins at program initialization time.  */
 465   tree (*builtin_function_ext_scope) (tree decl);
 466
 467   /* Used to set up the tree_contains_structure array for a frontend. */
 468   void (*init_ts) (void);
 469
 470   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 471      to a contained expression or DECL, possibly updating *TC or *SE
 472      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 473   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 474
 475   /* The EH personality function decl.  */
 476   tree (*eh_personality) (void);
 477
 478   /* Map a type to a runtime object to match type.  */
 479   tree (*eh_runtime_type) (tree);
 480
 481   /* If non-NULL, this is a function that returns a function decl to be
 482      executed if an unhandled exception is propagated out of a cleanup
 483      region.  For example, in C++, an exception thrown by a destructor
 484      during stack unwinding is required to result in a call to
 485      `std::terminate', so the C++ version of this function returns a
 486      FUNCTION_DECL for `std::terminate'.  */
 487   tree (*eh_protect_cleanup_actions) (void);
 488
 489   /* Return true if a stmt can fallthru.  Used by block_may_fallthru
 490      to possibly handle language trees.  */
 491   bool (*block_may_fallthru) (const_tree);
 492
 493   /* True if this language uses __cxa_end_cleanup when the ARM EABI
 494      is enabled.  */
 495   bool eh_use_cxa_end_cleanup;
 496
 497   /* True if this language requires deep unsharing of tree nodes prior to
 498      gimplification.  */
 499   bool deep_unsharing;
 500
 501   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 502      and langhooks.c accordingly.  */
 503 };
 504
 505 /* Each front end provides its own.  */
 506 extern struct lang_hooks lang_hooks;
 507
 508 extern tree add_builtin_function (const char *name, tree type,
 509                                   int function_code, enum built_in_class cl,
 510                                   const char *library_name,
 511                                   tree attrs);
 512
 513 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 514                                             int function_code,
 515                                             enum built_in_class cl,
 516                                             const char *library_name,
 517                                             tree attrs);
 518 extern tree add_builtin_type (const char *name, tree type);
 519
 520 #endif /* GCC_LANG_HOOKS_H */