gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
   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   /* 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   /* Nonzero if types that are identical are to be hashed so that only
 140      one copy is kept.  If a language requires unique types for each
 141      user-specified type, such as Ada, this should be set to TRUE.  */
 142   bool hash_types;
 143 };
 144
 145 /* Language hooks related to decls and the symbol table.  */
 146
 147 struct lang_hooks_for_decls
 148 {
 149   /* Returns nonzero if we are in the global binding level.  Ada
 150      returns -1 for an undocumented reason used in stor-layout.c.  */
 151   int (*global_bindings_p) (void);
 152
 153   /* Function to add a decl to the current scope level.  Takes one
 154      argument, a decl to add.  Returns that decl, or, if the same
 155      symbol is already declared, may return a different decl for that
 156      name.  */
 157   tree (*pushdecl) (tree);
 158
 159   /* Returns the chain of decls so far in the current scope level.  */
 160   tree (*getdecls) (void);
 161
 162   /* Returns true if DECL is explicit member function.  */
 163   bool (*function_decl_explicit_p) (tree);
 164
 165   /* Returns true when we should warn for an unused global DECL.
 166      We will already have checked that it has static binding.  */
 167   bool (*warn_unused_global) (const_tree);
 168
 169   /* Obtain a list of globals and do final output on them at end
 170      of compilation */
 171   void (*final_write_globals) (void);
 172
 173   /* True if this decl may be called via a sibcall.  */
 174   bool (*ok_for_sibcall) (const_tree);
 175
 176   /* Return the COMDAT group into which this DECL should be placed.
 177      It is known that the DECL belongs in *some* COMDAT group when
 178      this hook is called.  The return value will be used immediately,
 179      but not explicitly deallocated, so implementations should not use
 180      xmalloc to allocate the string returned.  (Typically, the return
 181      value will be the string already stored in an
 182      IDENTIFIER_NODE.)  */
 183   const char * (*comdat_group) (tree);
 184
 185   /* True if OpenMP should privatize what this DECL points to rather
 186      than the DECL itself.  */
 187   bool (*omp_privatize_by_reference) (const_tree);
 188
 189   /* Return sharing kind if OpenMP sharing attribute of DECL is
 190      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 191   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 192
 193   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 194      disregarded in OpenMP construct, because it is going to be
 195      remapped during OpenMP lowering.  SHARED is true if DECL
 196      is going to be shared, false if it is going to be privatized.  */
 197   bool (*omp_disregard_value_expr) (tree, bool);
 198
 199   /* Return true if DECL that is shared iff SHARED is true should
 200      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 201   bool (*omp_private_debug_clause) (tree, bool);
 202
 203   /* Return true if DECL in private clause needs
 204      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 205   bool (*omp_private_outer_ref) (tree);
 206
 207   /* Build and return code for a default constructor for DECL in
 208      response to CLAUSE.  OUTER is corresponding outer region's
 209      variable if needed.  Return NULL if nothing to be done.  */
 210   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 211
 212   /* Build and return code for a copy constructor from SRC to DST.  */
 213   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 214
 215   /* Similarly, except use an assignment operator instead.  */
 216   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 217
 218   /* Build and return code destructing DECL.  Return NULL if nothing
 219      to be done.  */
 220   tree (*omp_clause_dtor) (tree clause, tree decl);
 221
 222   /* Do language specific checking on an implicitly determined clause.  */
 223   void (*omp_finish_clause) (tree clause);
 224 };
 225
 226 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 227
 228 struct lang_hooks
 229 {
 230   /* String identifying the front end.  e.g. "GNU C++".  */
 231   const char *name;
 232
 233   /* sizeof (struct lang_identifier), so make_node () creates
 234      identifier nodes long enough for the language-specific slots.  */
 235   size_t identifier_size;
 236
 237   /* Determines the size of any language-specific tcc_constant or
 238      tcc_exceptional nodes.  Since it is called from make_node, the
 239      only information available is the tree code.  Expected to die
 240      on unrecognized codes.  */
 241   size_t (*tree_size) (enum tree_code);
 242
 243   /* The first callback made to the front end, for simple
 244      initialization needed before any calls to handle_option.  Return
 245      the language mask to filter the switch array with.  */
 246   unsigned int (*init_options) (unsigned int argc, const char **argv);
 247
 248   /* Callback used to perform language-specific initialization for the
 249      global diagnostic context structure.  */
 250   void (*initialize_diagnostics) (struct diagnostic_context *);
 251
 252   /* Handle the switch CODE, which has real type enum opt_code from
 253      options.h.  If the switch takes an argument, it is passed in ARG
 254      which points to permanent storage.  The handler is responsible for
 255      checking whether ARG is NULL, which indicates that no argument
 256      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 257      for the positive and negative forms respectively.
 258
 259      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 260      valid and should not be treated as language-independent too.  */
 261   int (*handle_option) (size_t code, const char *arg, int value);
 262
 263   /* Return false to use the default complaint about a missing
 264      argument, otherwise output a complaint and return true.  */
 265   bool (*missing_argument) (const char *opt, size_t code);
 266
 267   /* Called when all command line options have been parsed to allow
 268      further processing and initialization
 269
 270      Should return true to indicate that a compiler back-end is
 271      not required, such as with the -E option.
 272
 273      If errorcount is nonzero after this call the compiler exits
 274      immediately and the finish hook is not called.  */
 275   bool (*post_options) (const char **);
 276
 277   /* Called after post_options to initialize the front end.  Return
 278      false to indicate that no further compilation be performed, in
 279      which case the finish hook is called immediately.  */
 280   bool (*init) (void);
 281
 282   /* Called at the end of compilation, as a finalizer.  */
 283   void (*finish) (void);
 284
 285   /* Parses the entire file.  The argument is nonzero to cause bison
 286      parsers to dump debugging information during parsing.  */
 287   void (*parse_file) (int);
 288
 289   /* Determines if it's ok for a function to have no noreturn attribute.  */
 290   bool (*missing_noreturn_ok_p) (tree);
 291
 292   /* Called to obtain the alias set to be used for an expression or type.
 293      Returns -1 if the language does nothing special for it.  */
 294   alias_set_type (*get_alias_set) (tree);
 295
 296   /* Called by expand_expr for language-specific tree codes.
 297      Fourth argument is actually an enum expand_modifier.  */
 298   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 299
 300   /* Function to finish handling an incomplete decl at the end of
 301      compilation.  Default hook is does nothing.  */
 302   void (*finish_incomplete_decl) (tree);
 303
 304   /* Mark EXP saying that we need to be able to take the address of
 305      it; it should not be allocated in a register.  Return true if
 306      successful.  */
 307   bool (*mark_addressable) (tree);
 308
 309   /* Hook called by staticp for language-specific tree codes.  */
 310   tree (*staticp) (tree);
 311
 312   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 313      DECL_NODE with a newly GC-allocated copy.  */
 314   void (*dup_lang_specific_decl) (tree);
 315
 316   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 317      thing that the assembler should talk about, set
 318      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 319      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 320      assembler does not talk about it.  */
 321   void (*set_decl_assembler_name) (tree);
 322
 323   /* The front end can add its own statistics to -fmem-report with
 324      this hook.  It should output to stderr.  */
 325   void (*print_statistics) (void);
 326
 327   /* Called by print_tree when there is a tree of class tcc_exceptional
 328      that it doesn't know how to display.  */
 329   lang_print_tree_hook print_xnode;
 330
 331   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 332      and IDENTIFIER_NODE nodes.  */
 333   lang_print_tree_hook print_decl;
 334   lang_print_tree_hook print_type;
 335   lang_print_tree_hook print_identifier;
 336
 337   /* Computes the name to use to print a declaration.  DECL is the
 338      non-NULL declaration in question.  VERBOSITY determines what
 339      information will be printed: 0: DECL_NAME, demangled as
 340      necessary.  1: and scope information.  2: and any other
 341      information that might be interesting, such as function parameter
 342      types in C++.  */
 343   const char *(*decl_printable_name) (tree decl, int verbosity);
 344
 345   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 346      information will be printed: 0: DECL_NAME, demangled as
 347      necessary.  1: and scope information.  */
 348   const char *(*dwarf_name) (tree, int verbosity);
 349
 350   /* This compares two types for equivalence ("compatible" in C-based languages).
 351      This routine should only return 1 if it is sure.  It should not be used
 352      in contexts where erroneously returning 0 causes problems.  */
 353   int (*types_compatible_p) (tree x, tree y);
 354
 355   /* Called by report_error_function to print out function name.  */
 356   void (*print_error_function) (struct diagnostic_context *, const char *,
 357                                 struct diagnostic_info *);
 358
 359   /* Called from expr_size to calculate the size of the value of an
 360      expression in a language-dependent way.  Returns a tree for the size
 361      in bytes.  A frontend can call lhd_expr_size to get the default
 362      semantics in cases that it doesn't want to handle specially.  */
 363   tree (*expr_size) (const_tree);
 364
 365   /* Convert a character from the host's to the target's character
 366      set.  The character should be in what C calls the "basic source
 367      character set" (roughly, the set of characters defined by plain
 368      old ASCII).  The default is to return the character unchanged,
 369      which is correct in most circumstances.  Note that both argument
 370      and result should be sign-extended under -fsigned-char,
 371      zero-extended under -fno-signed-char.  */
 372   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 373
 374   /* Pointers to machine-independent attribute tables, for front ends
 375      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 376      table of attributes specific to the language, a table of
 377      attributes common to two or more languages (to allow easy
 378      sharing), and a table of attributes for checking formats.  */
 379   const struct attribute_spec *attribute_table;
 380   const struct attribute_spec *common_attribute_table;
 381   const struct attribute_spec *format_attribute_table;
 382
 383   struct lang_hooks_for_tree_inlining tree_inlining;
 384
 385   struct lang_hooks_for_callgraph callgraph;
 386
 387   struct lang_hooks_for_tree_dump tree_dump;
 388
 389   struct lang_hooks_for_decls decls;
 390
 391   struct lang_hooks_for_types types;
 392
 393   /* Perform language-specific gimplification on the argument.  Returns an
 394      enum gimplify_status, though we can't see that type here.  */
 395   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 396
 397   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 398      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 399   tree (*fold_obj_type_ref) (tree, tree);
 400
 401   /* Do language specific processing in the builtin function DECL  */
 402   tree (*builtin_function) (tree decl);
 403
 404   /* Like builtin_function, but make sure the scope is the external scope.
 405      This is used to delay putting in back end builtin functions until the ISA
 406      that defines the builtin is declared via function specific target options,
 407      which can save memory for machines like the x86_64 that have multiple
 408      ISAs.  If this points to the same function as builtin_function, the
 409      backend must add all of the builtins at program initialization time.  */
 410   tree (*builtin_function_ext_scope) (tree decl);
 411
 412   /* Used to set up the tree_contains_structure array for a frontend. */
 413   void (*init_ts) (void);
 414
 415   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 416      to a contained expression or DECL, possibly updating *TC or *SE
 417      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 418   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 419
 420   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 421      and langhooks.c accordingly.  */
 422 };
 423
 424 /* Each front end provides its own.  */
 425 extern const struct lang_hooks lang_hooks;
 426 extern tree add_builtin_function (const char *name, tree type,
 427                                   int function_code, enum built_in_class cl,
 428                                   const char *library_name,
 429                                   tree attrs);
 430
 431 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 432                                             int function_code,
 433                                             enum built_in_class cl,
 434                                             const char *library_name,
 435                                             tree attrs);
 436
 437 #endif /* GCC_LANG_HOOKS_H */