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   /* Emit thunks associated to function.  */
  54   void (*emit_associated_thunks) (tree);
  55 };
  56
  57 /* The following hooks are used by tree-dump.c.  */
  58
  59 struct lang_hooks_for_tree_dump
  60 {
  61   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  62      does not want the usual dumping of the second argument.  */
  63   bool (*dump_tree) (void *, tree);
  64
  65   /* Determine type qualifiers in a language-specific way.  */
  66   int (*type_quals) (const_tree);
  67 };
  68
  69 /* Hooks related to types.  */
  70
  71 struct lang_hooks_for_types
  72 {
  73   /* Return a new type (with the indicated CODE), doing whatever
  74      language-specific processing is required.  */
  75   tree (*make_type) (enum tree_code);
  76
  77   /* Return what kind of RECORD_TYPE this is, mainly for purposes of
  78      debug information.  If not defined, record types are assumed to
  79      be structures.  */
  80   enum classify_record (*classify_record) (tree);
  81
  82   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  83      mode.  */
  84   tree (*type_for_mode) (enum machine_mode, int);
  85
  86   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
  87      integer type with at least that precision.  */
  88   tree (*type_for_size) (unsigned, int);
  89
  90   /* True if the type is an instantiation of a generic type,
  91      e.g. C++ template implicit specializations.  */
  92   bool (*generic_p) (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 when we should warn for an unused global DECL.
 169      We will already have checked that it has static binding.  */
 170   bool (*warn_unused_global) (const_tree);
 171
 172   /* Obtain a list of globals and do final output on them at end
 173      of compilation */
 174   void (*final_write_globals) (void);
 175
 176   /* True if this decl may be called via a sibcall.  */
 177   bool (*ok_for_sibcall) (const_tree);
 178
 179   /* True if OpenMP should privatize what this DECL points to rather
 180      than the DECL itself.  */
 181   bool (*omp_privatize_by_reference) (const_tree);
 182
 183   /* Return sharing kind if OpenMP sharing attribute of DECL is
 184      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 185   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 186
 187   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 188      disregarded in OpenMP construct, because it is going to be
 189      remapped during OpenMP lowering.  SHARED is true if DECL
 190      is going to be shared, false if it is going to be privatized.  */
 191   bool (*omp_disregard_value_expr) (tree, bool);
 192
 193   /* Return true if DECL that is shared iff SHARED is true should
 194      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 195   bool (*omp_private_debug_clause) (tree, bool);
 196
 197   /* Return true if DECL in private clause needs
 198      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 199   bool (*omp_private_outer_ref) (tree);
 200
 201   /* Build and return code for a default constructor for DECL in
 202      response to CLAUSE.  OUTER is corresponding outer region's
 203      variable if needed.  Return NULL if nothing to be done.  */
 204   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 205
 206   /* Build and return code for a copy constructor from SRC to DST.  */
 207   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 208
 209   /* Similarly, except use an assignment operator instead.  */
 210   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 211
 212   /* Build and return code destructing DECL.  Return NULL if nothing
 213      to be done.  */
 214   tree (*omp_clause_dtor) (tree clause, tree decl);
 215
 216   /* Do language specific checking on an implicitly determined clause.  */
 217   void (*omp_finish_clause) (tree clause);
 218 };
 219
 220 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 221
 222 struct lang_hooks
 223 {
 224   /* String identifying the front end.  e.g. "GNU C++".  */
 225   const char *name;
 226
 227   /* sizeof (struct lang_identifier), so make_node () creates
 228      identifier nodes long enough for the language-specific slots.  */
 229   size_t identifier_size;
 230
 231   /* Determines the size of any language-specific tcc_constant or
 232      tcc_exceptional nodes.  Since it is called from make_node, the
 233      only information available is the tree code.  Expected to die
 234      on unrecognized codes.  */
 235   size_t (*tree_size) (enum tree_code);
 236
 237   /* The first callback made to the front end, for simple
 238      initialization needed before any calls to handle_option.  Return
 239      the language mask to filter the switch array with.  */
 240   unsigned int (*init_options) (unsigned int argc, const char **argv);
 241
 242   /* Callback used to perform language-specific initialization for the
 243      global diagnostic context structure.  */
 244   void (*initialize_diagnostics) (struct diagnostic_context *);
 245
 246   /* Handle the switch CODE, which has real type enum opt_code from
 247      options.h.  If the switch takes an argument, it is passed in ARG
 248      which points to permanent storage.  The handler is responsible for
 249      checking whether ARG is NULL, which indicates that no argument
 250      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 251      for the positive and negative forms respectively.
 252
 253      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 254      valid and should not be treated as language-independent too.  */
 255   int (*handle_option) (size_t code, const char *arg, int value);
 256
 257   /* Return false to use the default complaint about a missing
 258      argument, otherwise output a complaint and return true.  */
 259   bool (*missing_argument) (const char *opt, size_t code);
 260
 261   /* Called when all command line options have been parsed to allow
 262      further processing and initialization
 263
 264      Should return true to indicate that a compiler back-end is
 265      not required, such as with the -E option.
 266
 267      If errorcount is nonzero after this call the compiler exits
 268      immediately and the finish hook is not called.  */
 269   bool (*post_options) (const char **);
 270
 271   /* Called after post_options to initialize the front end.  Return
 272      false to indicate that no further compilation be performed, in
 273      which case the finish hook is called immediately.  */
 274   bool (*init) (void);
 275
 276   /* Called at the end of compilation, as a finalizer.  */
 277   void (*finish) (void);
 278
 279   /* Parses the entire file.  The argument is nonzero to cause bison
 280      parsers to dump debugging information during parsing.  */
 281   void (*parse_file) (int);
 282
 283   /* Determines if it's ok for a function to have no noreturn attribute.  */
 284   bool (*missing_noreturn_ok_p) (tree);
 285
 286   /* Called to obtain the alias set to be used for an expression or type.
 287      Returns -1 if the language does nothing special for it.  */
 288   alias_set_type (*get_alias_set) (tree);
 289
 290   /* Function to finish handling an incomplete decl at the end of
 291      compilation.  Default hook is does nothing.  */
 292   void (*finish_incomplete_decl) (tree);
 293
 294   /* Mark EXP saying that we need to be able to take the address of
 295      it; it should not be allocated in a register.  Return true if
 296      successful.  */
 297   bool (*mark_addressable) (tree);
 298
 299   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 300      DECL_NODE with a newly GC-allocated copy.  */
 301   void (*dup_lang_specific_decl) (tree);
 302
 303   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 304      thing that the assembler should talk about, set
 305      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 306      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 307      assembler does not talk about it.  */
 308   void (*set_decl_assembler_name) (tree);
 309
 310   /* The front end can add its own statistics to -fmem-report with
 311      this hook.  It should output to stderr.  */
 312   void (*print_statistics) (void);
 313
 314   /* Called by print_tree when there is a tree of class tcc_exceptional
 315      that it doesn't know how to display.  */
 316   lang_print_tree_hook print_xnode;
 317
 318   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 319      and IDENTIFIER_NODE nodes.  */
 320   lang_print_tree_hook print_decl;
 321   lang_print_tree_hook print_type;
 322   lang_print_tree_hook print_identifier;
 323
 324   /* Computes the name to use to print a declaration.  DECL is the
 325      non-NULL declaration in question.  VERBOSITY determines what
 326      information will be printed: 0: DECL_NAME, demangled as
 327      necessary.  1: and scope information.  2: and any other
 328      information that might be interesting, such as function parameter
 329      types in C++.  The name is in the internal character set and
 330      needs to be converted to the locale character set of diagnostics,
 331      or to the execution character set for strings such as
 332      __PRETTY_FUNCTION__.  */
 333   const char *(*decl_printable_name) (tree decl, int verbosity);
 334
 335   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 336      information will be printed: 0: DECL_NAME, demangled as
 337      necessary.  1: and scope information.  */
 338   const char *(*dwarf_name) (tree, int verbosity);
 339
 340   /* This compares two types for equivalence ("compatible" in C-based languages).
 341      This routine should only return 1 if it is sure.  It should not be used
 342      in contexts where erroneously returning 0 causes problems.  */
 343   int (*types_compatible_p) (tree x, tree y);
 344
 345   /* Called by report_error_function to print out function name.  */
 346   void (*print_error_function) (struct diagnostic_context *, const char *,
 347                                 struct diagnostic_info *);
 348
 349   /* Called from expr_size to calculate the size of the value of an
 350      expression in a language-dependent way.  Returns a tree for the size
 351      in bytes.  A frontend can call lhd_expr_size to get the default
 352      semantics in cases that it doesn't want to handle specially.  */
 353   tree (*expr_size) (const_tree);
 354
 355   /* Convert a character from the host's to the target's character
 356      set.  The character should be in what C calls the "basic source
 357      character set" (roughly, the set of characters defined by plain
 358      old ASCII).  The default is to return the character unchanged,
 359      which is correct in most circumstances.  Note that both argument
 360      and result should be sign-extended under -fsigned-char,
 361      zero-extended under -fno-signed-char.  */
 362   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 363
 364   /* Pointers to machine-independent attribute tables, for front ends
 365      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 366      table of attributes specific to the language, a table of
 367      attributes common to two or more languages (to allow easy
 368      sharing), and a table of attributes for checking formats.  */
 369   const struct attribute_spec *attribute_table;
 370   const struct attribute_spec *common_attribute_table;
 371   const struct attribute_spec *format_attribute_table;
 372
 373   struct lang_hooks_for_tree_inlining tree_inlining;
 374
 375   struct lang_hooks_for_callgraph callgraph;
 376
 377   struct lang_hooks_for_tree_dump tree_dump;
 378
 379   struct lang_hooks_for_decls decls;
 380
 381   struct lang_hooks_for_types types;
 382
 383   /* Perform language-specific gimplification on the argument.  Returns an
 384      enum gimplify_status, though we can't see that type here.  */
 385   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 386
 387   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 388      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 389   tree (*fold_obj_type_ref) (tree, tree);
 390
 391   /* Do language specific processing in the builtin function DECL  */
 392   tree (*builtin_function) (tree decl);
 393
 394   /* Like builtin_function, but make sure the scope is the external scope.
 395      This is used to delay putting in back end builtin functions until the ISA
 396      that defines the builtin is declared via function specific target options,
 397      which can save memory for machines like the x86_64 that have multiple
 398      ISAs.  If this points to the same function as builtin_function, the
 399      backend must add all of the builtins at program initialization time.  */
 400   tree (*builtin_function_ext_scope) (tree decl);
 401
 402   /* Used to set up the tree_contains_structure array for a frontend. */
 403   void (*init_ts) (void);
 404
 405   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 406      to a contained expression or DECL, possibly updating *TC or *SE
 407      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 408   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 409
 410   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 411      and langhooks.c accordingly.  */
 412 };
 413
 414 /* Each front end provides its own.  */
 415 extern const struct lang_hooks lang_hooks;
 416 extern tree add_builtin_function (const char *name, tree type,
 417                                   int function_code, enum built_in_class cl,
 418                                   const char *library_name,
 419                                   tree attrs);
 420
 421 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 422                                             int function_code,
 423                                             enum built_in_class cl,
 424                                             const char *library_name,
 425                                             tree attrs);
 426
 427 #endif /* GCC_LANG_HOOKS_H */