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   /* Perform any post compilation-proper parser cleanups and
 188      processing.  This is currently only needed for the C++ parser,
 189      which hopefully can be cleaned up so this hook is no longer
 190      necessary.  */
 191   void (*post_compilation_parsing_cleanups) (void);
 192
 193   /* True if this decl may be called via a sibcall.  */
 194   bool (*ok_for_sibcall) (const_tree);
 195
 196   /* True if OpenMP should privatize what this DECL points to rather
 197      than the DECL itself.  */
 198   bool (*omp_privatize_by_reference) (const_tree);
 199
 200   /* Return sharing kind if OpenMP sharing attribute of DECL is
 201      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 202   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 203
 204   /* Return decl that should be reported for DEFAULT(NONE) failure
 205      diagnostics.  Usually the DECL passed in.  */
 206   tree (*omp_report_decl) (tree);
 207
 208   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 209      disregarded in OpenMP construct, because it is going to be
 210      remapped during OpenMP lowering.  SHARED is true if DECL
 211      is going to be shared, false if it is going to be privatized.  */
 212   bool (*omp_disregard_value_expr) (tree, bool);
 213
 214   /* Return true if DECL that is shared iff SHARED is true should
 215      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 216   bool (*omp_private_debug_clause) (tree, bool);
 217
 218   /* Return true if DECL in private clause needs
 219      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 220   bool (*omp_private_outer_ref) (tree);
 221
 222   /* Build and return code for a default constructor for DECL in
 223      response to CLAUSE.  OUTER is corresponding outer region's
 224      variable if needed.  Return NULL if nothing to be done.  */
 225   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 226
 227   /* Build and return code for a copy constructor from SRC to DST.  */
 228   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 229
 230   /* Similarly, except use an assignment operator instead.  */
 231   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 232
 233   /* Build and return code for a constructor of DST that sets it to
 234      SRC + ADD.  */
 235   tree (*omp_clause_linear_ctor) (tree clause, tree dst, tree src, tree add);
 236
 237   /* Build and return code destructing DECL.  Return NULL if nothing
 238      to be done.  */
 239   tree (*omp_clause_dtor) (tree clause, tree decl);
 240
 241   /* Do language specific checking on an implicitly determined clause.  */
 242   void (*omp_finish_clause) (tree clause, gimple_seq *pre_p);
 243 };
 244
 245 /* Language hooks related to LTO serialization.  */
 246
 247 struct lang_hooks_for_lto
 248 {
 249   /* Begin a new LTO section named NAME.  */
 250   void (*begin_section) (const char *name);
 251
 252   /* Write DATA of length LEN to the currently open LTO section.  BLOCK is a
 253      pointer to the dynamically allocated memory containing DATA.  The
 254      append_data function is responsible for freeing it when it is no longer
 255      needed.  */
 256   void (*append_data) (const void *data, size_t len, void *block);
 257
 258   /* End the previously begun LTO section.  */
 259   void (*end_section) (void);
 260 };
 261
 262 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 263
 264 struct lang_hooks
 265 {
 266   /* String identifying the front end and optionally language standard
 267      version, e.g. "GNU C++98" or "GNU Java".  */
 268   const char *name;
 269
 270   /* sizeof (struct lang_identifier), so make_node () creates
 271      identifier nodes long enough for the language-specific slots.  */
 272   size_t identifier_size;
 273
 274   /* Remove any parts of the tree that are used only by the FE. */
 275   void (*free_lang_data) (tree);
 276
 277   /* Determines the size of any language-specific tcc_constant or
 278      tcc_exceptional nodes.  Since it is called from make_node, the
 279      only information available is the tree code.  Expected to die
 280      on unrecognized codes.  */
 281   size_t (*tree_size) (enum tree_code);
 282
 283   /* Return the language mask used for converting argv into a sequence
 284      of options.  */
 285   unsigned int (*option_lang_mask) (void);
 286
 287   /* Initialize variables in an options structure.  */
 288   void (*init_options_struct) (struct gcc_options *opts);
 289
 290   /* After the initialize_diagnostics hook is called, do any simple
 291      initialization needed before any calls to handle_option, other
 292      than that done by the init_options_struct hook.  */
 293   void (*init_options) (unsigned int decoded_options_count,
 294                         struct cl_decoded_option *decoded_options);
 295
 296   /* Callback used to perform language-specific initialization for the
 297      global diagnostic context structure.  */
 298   void (*initialize_diagnostics) (diagnostic_context *);
 299
 300   /* Return true if a warning should be given about option OPTION,
 301      which is for the wrong language, false if it should be quietly
 302      ignored.  */
 303   bool (*complain_wrong_lang_p) (const struct cl_option *option);
 304
 305   /* Handle the switch CODE, which has real type enum opt_code from
 306      options.h.  If the switch takes an argument, it is passed in ARG
 307      which points to permanent storage.  The handler is responsible for
 308      checking whether ARG is NULL, which indicates that no argument
 309      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 310      for the positive and negative forms respectively.  HANDLERS should
 311      be passed to any recursive handle_option calls.  LOC is the
 312      location of the option.
 313
 314      Return true if the switch is valid, false if invalid.  */
 315   bool (*handle_option) (size_t code, const char *arg, int value, int kind,
 316                          location_t loc,
 317                          const struct cl_option_handlers *handlers);
 318
 319   /* Called when all command line options have been parsed to allow
 320      further processing and initialization
 321
 322      Should return true to indicate that a compiler back-end is
 323      not required, such as with the -E option.
 324
 325      If errorcount is nonzero after this call the compiler exits
 326      immediately and the finish hook is not called.  */
 327   bool (*post_options) (const char **);
 328
 329   /* Called after post_options to initialize the front end.  Return
 330      false to indicate that no further compilation be performed, in
 331      which case the finish hook is called immediately.  */
 332   bool (*init) (void);
 333
 334   /* Called at the end of compilation, as a finalizer.  */
 335   void (*finish) (void);
 336
 337   /* Parses the entire file.  */
 338   void (*parse_file) (void);
 339
 340   /* Determines if it's ok for a function to have no noreturn attribute.  */
 341   bool (*missing_noreturn_ok_p) (tree);
 342
 343   /* Called to obtain the alias set to be used for an expression or type.
 344      Returns -1 if the language does nothing special for it.  */
 345   alias_set_type (*get_alias_set) (tree);
 346
 347   /* Function to finish handling an incomplete decl at the end of
 348      compilation.  Default hook is does nothing.  */
 349   void (*finish_incomplete_decl) (tree);
 350
 351   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 352      DECL_NODE with a newly GC-allocated copy.  */
 353   void (*dup_lang_specific_decl) (tree);
 354
 355   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 356      thing that the assembler should talk about, set
 357      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 358      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 359      assembler does not talk about it.  */
 360   void (*set_decl_assembler_name) (tree);
 361
 362   /* The front end can add its own statistics to -fmem-report with
 363      this hook.  It should output to stderr.  */
 364   void (*print_statistics) (void);
 365
 366   /* Called by print_tree when there is a tree of class tcc_exceptional
 367      that it doesn't know how to display.  */
 368   lang_print_tree_hook print_xnode;
 369
 370   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 371      and IDENTIFIER_NODE nodes.  */
 372   lang_print_tree_hook print_decl;
 373   lang_print_tree_hook print_type;
 374   lang_print_tree_hook print_identifier;
 375
 376   /* Computes the name to use to print a declaration.  DECL is the
 377      non-NULL declaration in question.  VERBOSITY determines what
 378      information will be printed: 0: DECL_NAME, demangled as
 379      necessary.  1: and scope information.  2: and any other
 380      information that might be interesting, such as function parameter
 381      types in C++.  The name is in the internal character set and
 382      needs to be converted to the locale character set of diagnostics,
 383      or to the execution character set for strings such as
 384      __PRETTY_FUNCTION__.  */
 385   const char *(*decl_printable_name) (tree decl, int verbosity);
 386
 387   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 388      information will be printed: 0: DECL_NAME, demangled as
 389      necessary.  1: and scope information.  */
 390   const char *(*dwarf_name) (tree, int verbosity);
 391
 392   /* This compares two types for equivalence ("compatible" in C-based languages).
 393      This routine should only return 1 if it is sure.  It should not be used
 394      in contexts where erroneously returning 0 causes problems.  */
 395   int (*types_compatible_p) (tree x, tree y);
 396
 397   /* Called by report_error_function to print out function name.  */
 398   void (*print_error_function) (diagnostic_context *, const char *,
 399                                 struct diagnostic_info *);
 400
 401   /* Convert a character from the host's to the target's character
 402      set.  The character should be in what C calls the "basic source
 403      character set" (roughly, the set of characters defined by plain
 404      old ASCII).  The default is to return the character unchanged,
 405      which is correct in most circumstances.  Note that both argument
 406      and result should be sign-extended under -fsigned-char,
 407      zero-extended under -fno-signed-char.  */
 408   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 409
 410   /* Pointers to machine-independent attribute tables, for front ends
 411      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 412      table of attributes specific to the language, a table of
 413      attributes common to two or more languages (to allow easy
 414      sharing), and a table of attributes for checking formats.  */
 415   const struct attribute_spec *attribute_table;
 416   const struct attribute_spec *common_attribute_table;
 417   const struct attribute_spec *format_attribute_table;
 418
 419   struct lang_hooks_for_tree_inlining tree_inlining;
 420
 421   struct lang_hooks_for_tree_dump tree_dump;
 422
 423   struct lang_hooks_for_decls decls;
 424
 425   struct lang_hooks_for_types types;
 426
 427   struct lang_hooks_for_lto lto;
 428
 429   /* Returns a TREE_VEC of the generic parameters of an instantiation of
 430      a generic type or decl, e.g. C++ template instantiation.  If
 431      TREE_CHAIN of the return value is set, it is an INTEGER_CST
 432      indicating how many of the elements are non-default.  */
 433   tree (*get_innermost_generic_parms) (const_tree);
 434
 435   /* Returns the TREE_VEC of arguments of an instantiation
 436      of a generic type of decl, e.g. C++ template instantiation.  */
 437   tree (*get_innermost_generic_args) (const_tree);
 438
 439   /* Determine if a tree is a function parameter pack.  */
 440   bool (*function_parameter_pack_p) (const_tree);
 441
 442   /* Perform language-specific gimplification on the argument.  Returns an
 443      enum gimplify_status, though we can't see that type here.  */
 444   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 445
 446   /* Do language specific processing in the builtin function DECL  */
 447   tree (*builtin_function) (tree decl);
 448
 449   /* Like builtin_function, but make sure the scope is the external scope.
 450      This is used to delay putting in back end builtin functions until the ISA
 451      that defines the builtin is declared via function specific target options,
 452      which can save memory for machines like the x86_64 that have multiple
 453      ISAs.  If this points to the same function as builtin_function, the
 454      backend must add all of the builtins at program initialization time.  */
 455   tree (*builtin_function_ext_scope) (tree decl);
 456
 457   /* Used to set up the tree_contains_structure array for a frontend. */
 458   void (*init_ts) (void);
 459
 460   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 461      to a contained expression or DECL, possibly updating *TC or *SE
 462      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 463   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 464
 465   /* The EH personality function decl.  */
 466   tree (*eh_personality) (void);
 467
 468   /* Map a type to a runtime object to match type.  */
 469   tree (*eh_runtime_type) (tree);
 470
 471   /* If non-NULL, this is a function that returns a function decl to be
 472      executed if an unhandled exception is propagated out of a cleanup
 473      region.  For example, in C++, an exception thrown by a destructor
 474      during stack unwinding is required to result in a call to
 475      `std::terminate', so the C++ version of this function returns a
 476      FUNCTION_DECL for `std::terminate'.  */
 477   tree (*eh_protect_cleanup_actions) (void);
 478
 479   /* Return true if a stmt can fallthru.  Used by block_may_fallthru
 480      to possibly handle language trees.  */
 481   bool (*block_may_fallthru) (const_tree);
 482
 483   /* True if this language uses __cxa_end_cleanup when the ARM EABI
 484      is enabled.  */
 485   bool eh_use_cxa_end_cleanup;
 486
 487   /* True if this language requires deep unsharing of tree nodes prior to
 488      gimplification.  */
 489   bool deep_unsharing;
 490
 491   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 492      and langhooks.c accordingly.  */
 493 };
 494
 495 /* Each front end provides its own.  */
 496 extern struct lang_hooks lang_hooks;
 497
 498 extern tree add_builtin_function (const char *name, tree type,
 499                                   int function_code, enum built_in_class cl,
 500                                   const char *library_name,
 501                                   tree attrs);
 502
 503 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 504                                             int function_code,
 505                                             enum built_in_class cl,
 506                                             const char *library_name,
 507                                             tree attrs);
 508 extern tree add_builtin_type (const char *name, tree type);
 509
 510 /* Language helper functions.  */
 511
 512 extern bool lang_GNU_C (void);
 513 extern bool lang_GNU_CXX (void);
 514 extern bool lang_GNU_Fortran (void);
 515
 516 #endif /* GCC_LANG_HOOKS_H */