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