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