gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright (C) 2001-2015 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) (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   /* Returns the tree that represents the underlying data type used to
 142      implement the enumeration.  The default implementation will just use
 143      type_for_size.  Used in dwarf2out.c to add a DW_AT_type base type
 144      reference to a DW_TAG_enumeration.  */
 145   tree (*enum_underlying_base_type) (const_tree);
 146 };
 147
 148 /* Language hooks related to decls and the symbol table.  */
 149
 150 struct lang_hooks_for_decls
 151 {
 152   /* Return true if we are in the global binding level.  This hook is really
 153      needed only if the language supports variable-sized types at the global
 154      level, i.e. declared outside subprograms.  */
 155   bool (*global_bindings_p) (void);
 156
 157   /* Function to add a decl to the current scope level.  Takes one
 158      argument, a decl to add.  Returns that decl, or, if the same
 159      symbol is already declared, may return a different decl for that
 160      name.  */
 161   tree (*pushdecl) (tree);
 162
 163   /* Returns the chain of decls so far in the current scope level.  */
 164   tree (*getdecls) (void);
 165
 166   /* Returns true if DECL is explicit member function.  */
 167   bool (*function_decl_explicit_p) (tree);
 168
 169   /* Returns true if DECL is C++11 deleted special member function.  */
 170   bool (*function_decl_deleted_p) (tree);
 171
 172   /* Returns True if the parameter is a generic parameter decl
 173      of a generic type, e.g a template template parameter for the C++ FE.  */
 174   bool (*generic_generic_parameter_decl_p) (const_tree);
 175
 176   /* Determine if a function parameter got expanded from a
 177      function parameter pack.  */
 178   bool (*function_parm_expanded_from_pack_p) (tree, tree);
 179
 180   /* Returns the generic declaration of a generic function instantiations.  */
 181   tree (*get_generic_function_decl) (const_tree);
 182
 183   /* Returns true when we should warn for an unused global DECL.
 184      We will already have checked that it has static binding.  */
 185   bool (*warn_unused_global) (const_tree);
 186
 187   /* Obtain a list of globals and do final output on them at end
 188      of compilation */
 189   void (*final_write_globals) (void);
 190
 191   /* True if this decl may be called via a sibcall.  */
 192   bool (*ok_for_sibcall) (const_tree);
 193
 194   /* True if OpenMP should privatize what this DECL points to rather
 195      than the DECL itself.  */
 196   bool (*omp_privatize_by_reference) (const_tree);
 197
 198   /* Return sharing kind if OpenMP sharing attribute of DECL is
 199      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 200   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 201
 202   /* Return decl that should be reported for DEFAULT(NONE) failure
 203      diagnostics.  Usually the DECL passed in.  */
 204   tree (*omp_report_decl) (tree);
 205
 206   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 207      disregarded in OpenMP construct, because it is going to be
 208      remapped during OpenMP lowering.  SHARED is true if DECL
 209      is going to be shared, false if it is going to be privatized.  */
 210   bool (*omp_disregard_value_expr) (tree, bool);
 211
 212   /* Return true if DECL that is shared iff SHARED is true should
 213      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 214   bool (*omp_private_debug_clause) (tree, bool);
 215
 216   /* Return true if DECL in private clause needs
 217      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 218   bool (*omp_private_outer_ref) (tree);
 219
 220   /* Build and return code for a default constructor for DECL in
 221      response to CLAUSE.  OUTER is corresponding outer region's
 222      variable if needed.  Return NULL if nothing to be done.  */
 223   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 224
 225   /* Build and return code for a copy constructor from SRC to DST.  */
 226   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 227
 228   /* Similarly, except use an assignment operator instead.  */
 229   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 230
 231   /* Build and return code for a constructor of DST that sets it to
 232      SRC + ADD.  */
 233   tree (*omp_clause_linear_ctor) (tree clause, tree dst, tree src, tree add);
 234
 235   /* Build and return code destructing DECL.  Return NULL if nothing
 236      to be done.  */
 237   tree (*omp_clause_dtor) (tree clause, tree decl);
 238
 239   /* Do language specific checking on an implicitly determined clause.  */
 240   void (*omp_finish_clause) (tree clause, gimple_seq *pre_p);
 241 };
 242
 243 /* Language hooks related to LTO serialization.  */
 244
 245 struct lang_hooks_for_lto
 246 {
 247   /* Begin a new LTO section named NAME.  */
 248   void (*begin_section) (const char *name);
 249
 250   /* Write DATA of length LEN to the currently open LTO section.  BLOCK is a
 251      pointer to the dynamically allocated memory containing DATA.  The
 252      append_data function is responsible for freeing it when it is no longer
 253      needed.  */
 254   void (*append_data) (const void *data, size_t len, void *block);
 255
 256   /* End the previously begun LTO section.  */
 257   void (*end_section) (void);
 258 };
 259
 260 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 261
 262 struct lang_hooks
 263 {
 264   /* String identifying the front end and optionally language standard
 265      version, e.g. "GNU C++98" or "GNU Java".  */
 266   const char *name;
 267
 268   /* sizeof (struct lang_identifier), so make_node () creates
 269      identifier nodes long enough for the language-specific slots.  */
 270   size_t identifier_size;
 271
 272   /* Remove any parts of the tree that are used only by the FE. */
 273   void (*free_lang_data) (tree);
 274
 275   /* Determines the size of any language-specific tcc_constant or
 276      tcc_exceptional nodes.  Since it is called from make_node, the
 277      only information available is the tree code.  Expected to die
 278      on unrecognized codes.  */
 279   size_t (*tree_size) (enum tree_code);
 280
 281   /* Return the language mask used for converting argv into a sequence
 282      of options.  */
 283   unsigned int (*option_lang_mask) (void);
 284
 285   /* Initialize variables in an options structure.  */
 286   void (*init_options_struct) (struct gcc_options *opts);
 287
 288   /* After the initialize_diagnostics hook is called, do any simple
 289      initialization needed before any calls to handle_option, other
 290      than that done by the init_options_struct hook.  */
 291   void (*init_options) (unsigned int decoded_options_count,
 292                         struct cl_decoded_option *decoded_options);
 293
 294   /* Callback used to perform language-specific initialization for the
 295      global diagnostic context structure.  */
 296   void (*initialize_diagnostics) (diagnostic_context *);
 297
 298   /* Return true if a warning should be given about option OPTION,
 299      which is for the wrong language, false if it should be quietly
 300      ignored.  */
 301   bool (*complain_wrong_lang_p) (const struct cl_option *option);
 302
 303   /* Handle the switch CODE, which has real type enum opt_code from
 304      options.h.  If the switch takes an argument, it is passed in ARG
 305      which points to permanent storage.  The handler is responsible for
 306      checking whether ARG is NULL, which indicates that no argument
 307      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 308      for the positive and negative forms respectively.  HANDLERS should
 309      be passed to any recursive handle_option calls.  LOC is the
 310      location of the option.
 311
 312      Return true if the switch is valid, false if invalid.  */
 313   bool (*handle_option) (size_t code, const char *arg, int value, int kind,
 314                          location_t loc,
 315                          const struct cl_option_handlers *handlers);
 316
 317   /* Called when all command line options have been parsed to allow
 318      further processing and initialization
 319
 320      Should return true to indicate that a compiler back-end is
 321      not required, such as with the -E option.
 322
 323      If errorcount is nonzero after this call the compiler exits
 324      immediately and the finish hook is not called.  */
 325   bool (*post_options) (const char **);
 326
 327   /* Called after post_options to initialize the front end.  Return
 328      false to indicate that no further compilation be performed, in
 329      which case the finish hook is called immediately.  */
 330   bool (*init) (void);
 331
 332   /* Called at the end of compilation, as a finalizer.  */
 333   void (*finish) (void);
 334
 335   /* Parses the entire file.  */
 336   void (*parse_file) (void);
 337
 338   /* Determines if it's ok for a function to have no noreturn attribute.  */
 339   bool (*missing_noreturn_ok_p) (tree);
 340
 341   /* Called to obtain the alias set to be used for an expression or type.
 342      Returns -1 if the language does nothing special for it.  */
 343   alias_set_type (*get_alias_set) (tree);
 344
 345   /* Function to finish handling an incomplete decl at the end of
 346      compilation.  Default hook is does nothing.  */
 347   void (*finish_incomplete_decl) (tree);
 348
 349   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 350      DECL_NODE with a newly GC-allocated copy.  */
 351   void (*dup_lang_specific_decl) (tree);
 352
 353   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 354      thing that the assembler should talk about, set
 355      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 356      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 357      assembler does not talk about it.  */
 358   void (*set_decl_assembler_name) (tree);
 359
 360   /* The front end can add its own statistics to -fmem-report with
 361      this hook.  It should output to stderr.  */
 362   void (*print_statistics) (void);
 363
 364   /* Called by print_tree when there is a tree of class tcc_exceptional
 365      that it doesn't know how to display.  */
 366   lang_print_tree_hook print_xnode;
 367
 368   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 369      and IDENTIFIER_NODE nodes.  */
 370   lang_print_tree_hook print_decl;
 371   lang_print_tree_hook print_type;
 372   lang_print_tree_hook print_identifier;
 373
 374   /* Computes the name to use to print a declaration.  DECL is the
 375      non-NULL declaration in question.  VERBOSITY determines what
 376      information will be printed: 0: DECL_NAME, demangled as
 377      necessary.  1: and scope information.  2: and any other
 378      information that might be interesting, such as function parameter
 379      types in C++.  The name is in the internal character set and
 380      needs to be converted to the locale character set of diagnostics,
 381      or to the execution character set for strings such as
 382      __PRETTY_FUNCTION__.  */
 383   const char *(*decl_printable_name) (tree decl, int verbosity);
 384
 385   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 386      information will be printed: 0: DECL_NAME, demangled as
 387      necessary.  1: and scope information.  */
 388   const char *(*dwarf_name) (tree, int verbosity);
 389
 390   /* This compares two types for equivalence ("compatible" in C-based languages).
 391      This routine should only return 1 if it is sure.  It should not be used
 392      in contexts where erroneously returning 0 causes problems.  */
 393   int (*types_compatible_p) (tree x, tree y);
 394
 395   /* Called by report_error_function to print out function name.  */
 396   void (*print_error_function) (diagnostic_context *, const char *,
 397                                 struct diagnostic_info *);
 398
 399   /* Convert a character from the host's to the target's character
 400      set.  The character should be in what C calls the "basic source
 401      character set" (roughly, the set of characters defined by plain
 402      old ASCII).  The default is to return the character unchanged,
 403      which is correct in most circumstances.  Note that both argument
 404      and result should be sign-extended under -fsigned-char,
 405      zero-extended under -fno-signed-char.  */
 406   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 407
 408   /* Pointers to machine-independent attribute tables, for front ends
 409      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 410      table of attributes specific to the language, a table of
 411      attributes common to two or more languages (to allow easy
 412      sharing), and a table of attributes for checking formats.  */
 413   const struct attribute_spec *attribute_table;
 414   const struct attribute_spec *common_attribute_table;
 415   const struct attribute_spec *format_attribute_table;
 416
 417   struct lang_hooks_for_tree_inlining tree_inlining;
 418
 419   struct lang_hooks_for_tree_dump tree_dump;
 420
 421   struct lang_hooks_for_decls decls;
 422
 423   struct lang_hooks_for_types types;
 424
 425   struct lang_hooks_for_lto lto;
 426
 427   /* Returns a TREE_VEC of the generic parameters of an instantiation of
 428      a generic type or decl, e.g. C++ template instantiation.  If
 429      TREE_CHAIN of the return value is set, it is an INTEGER_CST
 430      indicating how many of the elements are non-default.  */
 431   tree (*get_innermost_generic_parms) (const_tree);
 432
 433   /* Returns the TREE_VEC of arguments of an instantiation
 434      of a generic type of decl, e.g. C++ template instantiation.  */
 435   tree (*get_innermost_generic_args) (const_tree);
 436
 437   /* Determine if a tree is a function parameter pack.  */
 438   bool (*function_parameter_pack_p) (const_tree);
 439
 440   /* Perform language-specific gimplification on the argument.  Returns an
 441      enum gimplify_status, though we can't see that type here.  */
 442   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 443
 444   /* Do language specific processing in the builtin function DECL  */
 445   tree (*builtin_function) (tree decl);
 446
 447   /* Like builtin_function, but make sure the scope is the external scope.
 448      This is used to delay putting in back end builtin functions until the ISA
 449      that defines the builtin is declared via function specific target options,
 450      which can save memory for machines like the x86_64 that have multiple
 451      ISAs.  If this points to the same function as builtin_function, the
 452      backend must add all of the builtins at program initialization time.  */
 453   tree (*builtin_function_ext_scope) (tree decl);
 454
 455   /* Used to set up the tree_contains_structure array for a frontend. */
 456   void (*init_ts) (void);
 457
 458   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 459      to a contained expression or DECL, possibly updating *TC or *SE
 460      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 461   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 462
 463   /* The EH personality function decl.  */
 464   tree (*eh_personality) (void);
 465
 466   /* Map a type to a runtime object to match type.  */
 467   tree (*eh_runtime_type) (tree);
 468
 469   /* If non-NULL, this is a function that returns a function decl to be
 470      executed if an unhandled exception is propagated out of a cleanup
 471      region.  For example, in C++, an exception thrown by a destructor
 472      during stack unwinding is required to result in a call to
 473      `std::terminate', so the C++ version of this function returns a
 474      FUNCTION_DECL for `std::terminate'.  */
 475   tree (*eh_protect_cleanup_actions) (void);
 476
 477   /* Return true if a stmt can fallthru.  Used by block_may_fallthru
 478      to possibly handle language trees.  */
 479   bool (*block_may_fallthru) (const_tree);
 480
 481   /* True if this language uses __cxa_end_cleanup when the ARM EABI
 482      is enabled.  */
 483   bool eh_use_cxa_end_cleanup;
 484
 485   /* True if this language requires deep unsharing of tree nodes prior to
 486      gimplification.  */
 487   bool deep_unsharing;
 488
 489   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 490      and langhooks.c accordingly.  */
 491 };
 492
 493 /* Each front end provides its own.  */
 494 extern struct lang_hooks lang_hooks;
 495
 496 extern tree add_builtin_function (const char *name, tree type,
 497                                   int function_code, enum built_in_class cl,
 498                                   const char *library_name,
 499                                   tree attrs);
 500
 501 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 502                                             int function_code,
 503                                             enum built_in_class cl,
 504                                             const char *library_name,
 505                                             tree attrs);
 506 extern tree add_builtin_type (const char *name, tree type);
 507
 508 /* Language helper functions.  */
 509
 510 extern bool lang_GNU_C (void);
 511 extern bool lang_GNU_CXX (void);
 512
 513 #endif /* GCC_LANG_HOOKS_H */