gcc/langhooks.h

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