gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
   3    2011 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef GCC_LANG_HOOKS_H
  22 #define GCC_LANG_HOOKS_H
  23
  24 /* FIXME: This file should be #include-d after tree.h (for enum tree_code).  */
  25
  26 struct diagnostic_info;
  27
  28 struct gimplify_omp_ctx;
  29
  30 struct array_descr_info;
  31
  32 /* A print hook for print_tree ().  */
  33 typedef void (*lang_print_tree_hook) (FILE *, tree, int indent);
  34
  35 enum classify_record
  36   { RECORD_IS_STRUCT, RECORD_IS_CLASS, RECORD_IS_INTERFACE };
  37
  38 /* The following hooks are documented in langhooks.c.  Must not be
  39    NULL.  */
  40
  41 struct lang_hooks_for_tree_inlining
  42 {
  43   bool (*var_mod_type_p) (tree, tree);
  44 };
  45
  46 /* The following hooks are used by tree-dump.c.  */
  47
  48 struct lang_hooks_for_tree_dump
  49 {
  50   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  51      does not want the usual dumping of the second argument.  */
  52   bool (*dump_tree) (void *, tree);
  53
  54   /* Determine type qualifiers in a language-specific way.  */
  55   int (*type_quals) (const_tree);
  56 };
  57
  58 /* Hooks related to types.  */
  59
  60 struct lang_hooks_for_types
  61 {
  62   /* Return a new type (with the indicated CODE), doing whatever
  63      language-specific processing is required.  */
  64   tree (*make_type) (enum tree_code);
  65
  66   /* Return what kind of RECORD_TYPE this is, mainly for purposes of
  67      debug information.  If not defined, record types are assumed to
  68      be structures.  */
  69   enum classify_record (*classify_record) (tree);
  70
  71   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  72      mode.  */
  73   tree (*type_for_mode) (enum machine_mode, int);
  74
  75   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
  76      integer type with at least that precision.  */
  77   tree (*type_for_size) (unsigned, int);
  78
  79   /* True if the type is an instantiation of a generic type,
  80      e.g. C++ template implicit specializations.  */
  81   bool (*generic_p) (const_tree);
  82
  83   /* Returns the TREE_VEC of elements of a given generic argument pack.  */
  84   tree (*get_argument_pack_elems) (const_tree);
  85
  86   /* Given a type, apply default promotions to unnamed function
  87      arguments and return the new type.  Return the same type if no
  88      change.  Required by any language that supports variadic
  89      arguments.  The default hook dies.  */
  90   tree (*type_promotes_to) (tree);
  91
  92   /* Register TYPE as a builtin type with the indicated NAME.  The
  93      TYPE is placed in the outermost lexical scope.  The semantics
  94      should be analogous to:
  95
  96        typedef TYPE NAME;
  97
  98      in C.  The default hook ignores the declaration.  */
  99   void (*register_builtin_type) (tree, const char *);
 100
 101   /* This routine is called in tree.c to print an error message for
 102      invalid use of an incomplete type.  VALUE is the expression that
 103      was used (or 0 if that isn't known) and TYPE is the type that was
 104      invalid.  */
 105   void (*incomplete_type_error) (const_tree value, const_tree type);
 106
 107   /* Called from assign_temp to return the maximum size, if there is one,
 108      for a type.  */
 109   tree (*max_size) (const_tree);
 110
 111   /* Register language specific type size variables as potentially OpenMP
 112      firstprivate variables.  */
 113   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 114
 115   /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
 116      Called only after doing all language independent checks.
 117      At present, this function is only called when both TYPE1 and TYPE2 are
 118      FUNCTION_TYPEs.  */
 119   bool (*type_hash_eq) (const_tree, const_tree);
 120
 121   /* Return TRUE if TYPE uses a hidden descriptor and fills in information
 122      for the debugger about the array bounds, strides, etc.  */
 123   bool (*get_array_descr_info) (const_tree, struct array_descr_info *);
 124
 125   /* Fill in information for the debugger about the bounds of TYPE.  */
 126   void (*get_subrange_bounds) (const_tree, tree *, tree *);
 127
 128   /* A type descriptive of TYPE's complex layout generated to help the
 129      debugger to decode variable-length or self-referential constructs.
 130      This is only used for the AT_GNAT_descriptive_type DWARF attribute.  */
 131   tree (*descriptive_type) (const_tree);
 132
 133   /* If we requested a pointer to a vector, build up the pointers that
 134      we stripped off while looking for the inner type.  Similarly for
 135      return values from functions.  The argument TYPE is the top of the
 136      chain, and BOTTOM is the new type which we will point to.  */
 137   tree (*reconstruct_complex_type) (tree, tree);
 138 };
 139
 140 /* Language hooks related to decls and the symbol table.  */
 141
 142 struct lang_hooks_for_decls
 143 {
 144   /* Return true if we are in the global binding level.  This hook is really
 145      needed only if the language supports variable-sized types at the global
 146      level, i.e. declared outside subprograms.  */
 147   bool (*global_bindings_p) (void);
 148
 149   /* Function to add a decl to the current scope level.  Takes one
 150      argument, a decl to add.  Returns that decl, or, if the same
 151      symbol is already declared, may return a different decl for that
 152      name.  */
 153   tree (*pushdecl) (tree);
 154
 155   /* Returns the chain of decls so far in the current scope level.  */
 156   tree (*getdecls) (void);
 157
 158   /* Returns true if DECL is explicit member function.  */
 159   bool (*function_decl_explicit_p) (tree);
 160
 161   /* Returns True if the parameter is a generic parameter decl
 162      of a generic type, e.g a template template parameter for the C++ FE.  */
 163   bool (*generic_generic_parameter_decl_p) (const_tree);
 164
 165   /* Determine if a function parameter got expanded from a
 166      function parameter pack.  */
 167   bool (*function_parm_expanded_from_pack_p) (tree, tree);
 168
 169   /* Returns the generic declaration of a generic function instantiations.  */
 170   tree (*get_generic_function_decl) (const_tree);
 171
 172   /* Returns true when we should warn for an unused global DECL.
 173      We will already have checked that it has static binding.  */
 174   bool (*warn_unused_global) (const_tree);
 175
 176   /* Obtain a list of globals and do final output on them at end
 177      of compilation */
 178   void (*final_write_globals) (void);
 179
 180   /* True if this decl may be called via a sibcall.  */
 181   bool (*ok_for_sibcall) (const_tree);
 182
 183   /* True if OpenMP should privatize what this DECL points to rather
 184      than the DECL itself.  */
 185   bool (*omp_privatize_by_reference) (const_tree);
 186
 187   /* Return sharing kind if OpenMP sharing attribute of DECL is
 188      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 189   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 190
 191   /* Return decl that should be reported for DEFAULT(NONE) failure
 192      diagnostics.  Usually the DECL passed in.  */
 193   tree (*omp_report_decl) (tree);
 194
 195   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 196      disregarded in OpenMP construct, because it is going to be
 197      remapped during OpenMP lowering.  SHARED is true if DECL
 198      is going to be shared, false if it is going to be privatized.  */
 199   bool (*omp_disregard_value_expr) (tree, bool);
 200
 201   /* Return true if DECL that is shared iff SHARED is true should
 202      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 203   bool (*omp_private_debug_clause) (tree, bool);
 204
 205   /* Return true if DECL in private clause needs
 206      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 207   bool (*omp_private_outer_ref) (tree);
 208
 209   /* Build and return code for a default constructor for DECL in
 210      response to CLAUSE.  OUTER is corresponding outer region's
 211      variable if needed.  Return NULL if nothing to be done.  */
 212   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 213
 214   /* Build and return code for a copy constructor from SRC to DST.  */
 215   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 216
 217   /* Similarly, except use an assignment operator instead.  */
 218   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 219
 220   /* Build and return code destructing DECL.  Return NULL if nothing
 221      to be done.  */
 222   tree (*omp_clause_dtor) (tree clause, tree decl);
 223
 224   /* Do language specific checking on an implicitly determined clause.  */
 225   void (*omp_finish_clause) (tree clause);
 226 };
 227
 228 /* Language hooks related to LTO serialization.  */
 229
 230 struct lang_hooks_for_lto
 231 {
 232   /* Begin a new LTO section named NAME.  */
 233   void (*begin_section) (const char *name);
 234
 235   /* Write DATA of length LEN to the currently open LTO section.  BLOCK is a
 236      pointer to the dynamically allocated memory containing DATA.  The
 237      append_data function is responsible for freeing it when it is no longer
 238      needed.  */
 239   void (*append_data) (const void *data, size_t len, void *block);
 240
 241   /* End the previously begun LTO section.  */
 242   void (*end_section) (void);
 243 };
 244
 245 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 246
 247 struct lang_hooks
 248 {
 249   /* String identifying the front end.  e.g. "GNU C++".  */
 250   const char *name;
 251
 252   /* sizeof (struct lang_identifier), so make_node () creates
 253      identifier nodes long enough for the language-specific slots.  */
 254   size_t identifier_size;
 255
 256   /* Remove any parts of the tree that are used only by the FE. */
 257   void (*free_lang_data) (tree);
 258
 259   /* Determines the size of any language-specific tcc_constant or
 260      tcc_exceptional nodes.  Since it is called from make_node, the
 261      only information available is the tree code.  Expected to die
 262      on unrecognized codes.  */
 263   size_t (*tree_size) (enum tree_code);
 264
 265   /* Return the language mask used for converting argv into a sequence
 266      of options.  */
 267   unsigned int (*option_lang_mask) (void);
 268
 269   /* Initialize variables in an options structure.  */
 270   void (*init_options_struct) (struct gcc_options *opts);
 271
 272   /* After the initialize_diagnostics hook is called, do any simple
 273      initialization needed before any calls to handle_option, other
 274      than that done by the init_options_struct hook.  */
 275   void (*init_options) (unsigned int decoded_options_count,
 276                         struct cl_decoded_option *decoded_options);
 277
 278   /* Callback used to perform language-specific initialization for the
 279      global diagnostic context structure.  */
 280   void (*initialize_diagnostics) (diagnostic_context *);
 281
 282   /* Return true if a warning should be given about option OPTION,
 283      which is for the wrong language, false if it should be quietly
 284      ignored.  */
 285   bool (*complain_wrong_lang_p) (const struct cl_option *option);
 286
 287   /* Handle the switch CODE, which has real type enum opt_code from
 288      options.h.  If the switch takes an argument, it is passed in ARG
 289      which points to permanent storage.  The handler is responsible for
 290      checking whether ARG is NULL, which indicates that no argument
 291      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 292      for the positive and negative forms respectively.  HANDLERS should
 293      be passed to any recursive handle_option calls.  LOC is the
 294      location of the option.
 295
 296      Return true if the switch is valid, false if invalid.  */
 297   bool (*handle_option) (size_t code, const char *arg, int value, int kind,
 298                          location_t loc,
 299                          const struct cl_option_handlers *handlers);
 300
 301   /* Called when all command line options have been parsed to allow
 302      further processing and initialization
 303
 304      Should return true to indicate that a compiler back-end is
 305      not required, such as with the -E option.
 306
 307      If errorcount is nonzero after this call the compiler exits
 308      immediately and the finish hook is not called.  */
 309   bool (*post_options) (const char **);
 310
 311   /* Called after post_options to initialize the front end.  Return
 312      false to indicate that no further compilation be performed, in
 313      which case the finish hook is called immediately.  */
 314   bool (*init) (void);
 315
 316   /* Called at the end of compilation, as a finalizer.  */
 317   void (*finish) (void);
 318
 319   /* Parses the entire file.  */
 320   void (*parse_file) (void);
 321
 322   /* Determines if it's ok for a function to have no noreturn attribute.  */
 323   bool (*missing_noreturn_ok_p) (tree);
 324
 325   /* Called to obtain the alias set to be used for an expression or type.
 326      Returns -1 if the language does nothing special for it.  */
 327   alias_set_type (*get_alias_set) (tree);
 328
 329   /* Function to finish handling an incomplete decl at the end of
 330      compilation.  Default hook is does nothing.  */
 331   void (*finish_incomplete_decl) (tree);
 332
 333   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 334      DECL_NODE with a newly GC-allocated copy.  */
 335   void (*dup_lang_specific_decl) (tree);
 336
 337   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 338      thing that the assembler should talk about, set
 339      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 340      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 341      assembler does not talk about it.  */
 342   void (*set_decl_assembler_name) (tree);
 343
 344   /* The front end can add its own statistics to -fmem-report with
 345      this hook.  It should output to stderr.  */
 346   void (*print_statistics) (void);
 347
 348   /* Called by print_tree when there is a tree of class tcc_exceptional
 349      that it doesn't know how to display.  */
 350   lang_print_tree_hook print_xnode;
 351
 352   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 353      and IDENTIFIER_NODE nodes.  */
 354   lang_print_tree_hook print_decl;
 355   lang_print_tree_hook print_type;
 356   lang_print_tree_hook print_identifier;
 357
 358   /* Computes the name to use to print a declaration.  DECL is the
 359      non-NULL declaration in question.  VERBOSITY determines what
 360      information will be printed: 0: DECL_NAME, demangled as
 361      necessary.  1: and scope information.  2: and any other
 362      information that might be interesting, such as function parameter
 363      types in C++.  The name is in the internal character set and
 364      needs to be converted to the locale character set of diagnostics,
 365      or to the execution character set for strings such as
 366      __PRETTY_FUNCTION__.  */
 367   const char *(*decl_printable_name) (tree decl, int verbosity);
 368
 369   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 370      information will be printed: 0: DECL_NAME, demangled as
 371      necessary.  1: and scope information.  */
 372   const char *(*dwarf_name) (tree, int verbosity);
 373
 374   /* This compares two types for equivalence ("compatible" in C-based languages).
 375      This routine should only return 1 if it is sure.  It should not be used
 376      in contexts where erroneously returning 0 causes problems.  */
 377   int (*types_compatible_p) (tree x, tree y);
 378
 379   /* Called by report_error_function to print out function name.  */
 380   void (*print_error_function) (diagnostic_context *, const char *,
 381                                 struct diagnostic_info *);
 382
 383   /* Convert a character from the host's to the target's character
 384      set.  The character should be in what C calls the "basic source
 385      character set" (roughly, the set of characters defined by plain
 386      old ASCII).  The default is to return the character unchanged,
 387      which is correct in most circumstances.  Note that both argument
 388      and result should be sign-extended under -fsigned-char,
 389      zero-extended under -fno-signed-char.  */
 390   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 391
 392   /* Pointers to machine-independent attribute tables, for front ends
 393      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 394      table of attributes specific to the language, a table of
 395      attributes common to two or more languages (to allow easy
 396      sharing), and a table of attributes for checking formats.  */
 397   const struct attribute_spec *attribute_table;
 398   const struct attribute_spec *common_attribute_table;
 399   const struct attribute_spec *format_attribute_table;
 400
 401   struct lang_hooks_for_tree_inlining tree_inlining;
 402
 403   struct lang_hooks_for_tree_dump tree_dump;
 404
 405   struct lang_hooks_for_decls decls;
 406
 407   struct lang_hooks_for_types types;
 408
 409   struct lang_hooks_for_lto lto;
 410
 411   /* Returns the generic parameters of an instantiation of
 412      a generic type or decl, e.g. C++ template instantiation.  */
 413   tree (*get_innermost_generic_parms) (const_tree);
 414
 415   /* Returns the TREE_VEC of arguments of an instantiation
 416      of a generic type of decl, e.g. C++ template instantiation.  */
 417   tree (*get_innermost_generic_args) (const_tree);
 418
 419   /* Determine if a tree is a function parameter pack.  */
 420   bool (*function_parameter_pack_p) (const_tree);
 421
 422   /* Perform language-specific gimplification on the argument.  Returns an
 423      enum gimplify_status, though we can't see that type here.  */
 424   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 425
 426   /* Do language specific processing in the builtin function DECL  */
 427   tree (*builtin_function) (tree decl);
 428
 429   /* Like builtin_function, but make sure the scope is the external scope.
 430      This is used to delay putting in back end builtin functions until the ISA
 431      that defines the builtin is declared via function specific target options,
 432      which can save memory for machines like the x86_64 that have multiple
 433      ISAs.  If this points to the same function as builtin_function, the
 434      backend must add all of the builtins at program initialization time.  */
 435   tree (*builtin_function_ext_scope) (tree decl);
 436
 437   /* Used to set up the tree_contains_structure array for a frontend. */
 438   void (*init_ts) (void);
 439
 440   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 441      to a contained expression or DECL, possibly updating *TC or *SE
 442      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 443   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 444
 445   /* The EH personality function decl.  */
 446   tree (*eh_personality) (void);
 447
 448   /* Map a type to a runtime object to match type.  */
 449   tree (*eh_runtime_type) (tree);
 450
 451   /* If non-NULL, this is a function that returns a function decl to be
 452      executed if an unhandled exception is propagated out of a cleanup
 453      region.  For example, in C++, an exception thrown by a destructor
 454      during stack unwinding is required to result in a call to
 455      `std::terminate', so the C++ version of this function returns a
 456      FUNCTION_DECL for `std::terminate'.  */
 457   tree (*eh_protect_cleanup_actions) (void);
 458
 459   /* True if this language uses __cxa_end_cleanup when the ARM EABI
 460      is enabled.  */
 461   bool eh_use_cxa_end_cleanup;
 462
 463   /* True if this language requires deep unsharing of tree nodes prior to
 464      gimplification.  */
 465   bool deep_unsharing;
 466
 467   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 468      and langhooks.c accordingly.  */
 469 };
 470
 471 /* Each front end provides its own.  */
 472 extern struct lang_hooks lang_hooks;
 473
 474 extern tree add_builtin_function (const char *name, tree type,
 475                                   int function_code, enum built_in_class cl,
 476                                   const char *library_name,
 477                                   tree attrs);
 478
 479 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 480                                             int function_code,
 481                                             enum built_in_class cl,
 482                                             const char *library_name,
 483                                             tree attrs);
 484 extern tree add_builtin_type (const char *name, tree type);
 485
 486 #endif /* GCC_LANG_HOOKS_H */