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 when we should warn for an unused global DECL.
 163      We will already have checked that it has static binding.  */
 164   bool (*warn_unused_global) (const_tree);
 165
 166   /* Obtain a list of globals and do final output on them at end
 167      of compilation */
 168   void (*final_write_globals) (void);
 169
 170   /* True if this decl may be called via a sibcall.  */
 171   bool (*ok_for_sibcall) (const_tree);
 172
 173   /* Return the COMDAT group into which this DECL should be placed.
 174      It is known that the DECL belongs in *some* COMDAT group when
 175      this hook is called.  The return value will be used immediately,
 176      but not explicitly deallocated, so implementations should not use
 177      xmalloc to allocate the string returned.  (Typically, the return
 178      value will be the string already stored in an
 179      IDENTIFIER_NODE.)  */
 180   const char * (*comdat_group) (tree);
 181
 182   /* True if OpenMP should privatize what this DECL points to rather
 183      than the DECL itself.  */
 184   bool (*omp_privatize_by_reference) (const_tree);
 185
 186   /* Return sharing kind if OpenMP sharing attribute of DECL is
 187      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 188   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 189
 190   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 191      disregarded in OpenMP construct, because it is going to be
 192      remapped during OpenMP lowering.  SHARED is true if DECL
 193      is going to be shared, false if it is going to be privatized.  */
 194   bool (*omp_disregard_value_expr) (tree, bool);
 195
 196   /* Return true if DECL that is shared iff SHARED is true should
 197      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 198   bool (*omp_private_debug_clause) (tree, bool);
 199
 200   /* Return true if DECL in private clause needs
 201      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 202   bool (*omp_private_outer_ref) (tree);
 203
 204   /* Build and return code for a default constructor for DECL in
 205      response to CLAUSE.  OUTER is corresponding outer region's
 206      variable if needed.  Return NULL if nothing to be done.  */
 207   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 208
 209   /* Build and return code for a copy constructor from SRC to DST.  */
 210   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 211
 212   /* Similarly, except use an assignment operator instead.  */
 213   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 214
 215   /* Build and return code destructing DECL.  Return NULL if nothing
 216      to be done.  */
 217   tree (*omp_clause_dtor) (tree clause, tree decl);
 218
 219   /* Do language specific checking on an implicitly determined clause.  */
 220   void (*omp_finish_clause) (tree clause);
 221 };
 222
 223 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 224
 225 struct lang_hooks
 226 {
 227   /* String identifying the front end.  e.g. "GNU C++".  */
 228   const char *name;
 229
 230   /* sizeof (struct lang_identifier), so make_node () creates
 231      identifier nodes long enough for the language-specific slots.  */
 232   size_t identifier_size;
 233
 234   /* Determines the size of any language-specific tcc_constant or
 235      tcc_exceptional nodes.  Since it is called from make_node, the
 236      only information available is the tree code.  Expected to die
 237      on unrecognized codes.  */
 238   size_t (*tree_size) (enum tree_code);
 239
 240   /* The first callback made to the front end, for simple
 241      initialization needed before any calls to handle_option.  Return
 242      the language mask to filter the switch array with.  */
 243   unsigned int (*init_options) (unsigned int argc, const char **argv);
 244
 245   /* Callback used to perform language-specific initialization for the
 246      global diagnostic context structure.  */
 247   void (*initialize_diagnostics) (struct diagnostic_context *);
 248
 249   /* Handle the switch CODE, which has real type enum opt_code from
 250      options.h.  If the switch takes an argument, it is passed in ARG
 251      which points to permanent storage.  The handler is responsible for
 252      checking whether ARG is NULL, which indicates that no argument
 253      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 254      for the positive and negative forms respectively.
 255
 256      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 257      valid and should not be treated as language-independent too.  */
 258   int (*handle_option) (size_t code, const char *arg, int value);
 259
 260   /* Return false to use the default complaint about a missing
 261      argument, otherwise output a complaint and return true.  */
 262   bool (*missing_argument) (const char *opt, size_t code);
 263
 264   /* Called when all command line options have been parsed to allow
 265      further processing and initialization
 266
 267      Should return true to indicate that a compiler back-end is
 268      not required, such as with the -E option.
 269
 270      If errorcount is nonzero after this call the compiler exits
 271      immediately and the finish hook is not called.  */
 272   bool (*post_options) (const char **);
 273
 274   /* Called after post_options to initialize the front end.  Return
 275      false to indicate that no further compilation be performed, in
 276      which case the finish hook is called immediately.  */
 277   bool (*init) (void);
 278
 279   /* Called at the end of compilation, as a finalizer.  */
 280   void (*finish) (void);
 281
 282   /* Parses the entire file.  The argument is nonzero to cause bison
 283      parsers to dump debugging information during parsing.  */
 284   void (*parse_file) (int);
 285
 286   /* Determines if it's ok for a function to have no noreturn attribute.  */
 287   bool (*missing_noreturn_ok_p) (tree);
 288
 289   /* Called to obtain the alias set to be used for an expression or type.
 290      Returns -1 if the language does nothing special for it.  */
 291   alias_set_type (*get_alias_set) (tree);
 292
 293   /* Called by expand_expr for language-specific tree codes.
 294      Fourth argument is actually an enum expand_modifier.  */
 295   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 296
 297   /* Function to finish handling an incomplete decl at the end of
 298      compilation.  Default hook is does nothing.  */
 299   void (*finish_incomplete_decl) (tree);
 300
 301   /* Mark EXP saying that we need to be able to take the address of
 302      it; it should not be allocated in a register.  Return true if
 303      successful.  */
 304   bool (*mark_addressable) (tree);
 305
 306   /* Hook called by staticp for language-specific tree codes.  */
 307   tree (*staticp) (tree);
 308
 309   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 310      DECL_NODE with a newly GC-allocated copy.  */
 311   void (*dup_lang_specific_decl) (tree);
 312
 313   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 314      thing that the assembler should talk about, set
 315      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 316      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 317      assembler does not talk about it.  */
 318   void (*set_decl_assembler_name) (tree);
 319
 320   /* Nonzero if this front end does not generate a dummy BLOCK between
 321      the outermost scope of the function and the FUNCTION_DECL.  See
 322      is_body_block in stmt.c, and its callers.  */
 323   bool no_body_blocks;
 324
 325   /* The front end can add its own statistics to -fmem-report with
 326      this hook.  It should output to stderr.  */
 327   void (*print_statistics) (void);
 328
 329   /* Called by print_tree when there is a tree of class tcc_exceptional
 330      that it doesn't know how to display.  */
 331   lang_print_tree_hook print_xnode;
 332
 333   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 334      and IDENTIFIER_NODE nodes.  */
 335   lang_print_tree_hook print_decl;
 336   lang_print_tree_hook print_type;
 337   lang_print_tree_hook print_identifier;
 338
 339   /* Computes the name to use to print a declaration.  DECL is the
 340      non-NULL declaration in question.  VERBOSITY determines what
 341      information will be printed: 0: DECL_NAME, demangled as
 342      necessary.  1: and scope information.  2: and any other
 343      information that might be interesting, such as function parameter
 344      types in C++.  */
 345   const char *(*decl_printable_name) (tree decl, int verbosity);
 346
 347   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 348      information will be printed: 0: DECL_NAME, demangled as
 349      necessary.  1: and scope information.  */
 350   const char *(*dwarf_name) (tree, int verbosity);
 351
 352   /* This compares two types for equivalence ("compatible" in C-based languages).
 353      This routine should only return 1 if it is sure.  It should not be used
 354      in contexts where erroneously returning 0 causes problems.  */
 355   int (*types_compatible_p) (tree x, tree y);
 356
 357   /* Called by report_error_function to print out function name.  */
 358   void (*print_error_function) (struct diagnostic_context *, const char *,
 359                                 struct diagnostic_info *);
 360
 361   /* Called from expr_size to calculate the size of the value of an
 362      expression in a language-dependent way.  Returns a tree for the size
 363      in bytes.  A frontend can call lhd_expr_size to get the default
 364      semantics in cases that it doesn't want to handle specially.  */
 365   tree (*expr_size) (const_tree);
 366
 367   /* Convert a character from the host's to the target's character
 368      set.  The character should be in what C calls the "basic source
 369      character set" (roughly, the set of characters defined by plain
 370      old ASCII).  The default is to return the character unchanged,
 371      which is correct in most circumstances.  Note that both argument
 372      and result should be sign-extended under -fsigned-char,
 373      zero-extended under -fno-signed-char.  */
 374   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 375
 376   /* Pointers to machine-independent attribute tables, for front ends
 377      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 378      table of attributes specific to the language, a table of
 379      attributes common to two or more languages (to allow easy
 380      sharing), and a table of attributes for checking formats.  */
 381   const struct attribute_spec *attribute_table;
 382   const struct attribute_spec *common_attribute_table;
 383   const struct attribute_spec *format_attribute_table;
 384
 385   struct lang_hooks_for_tree_inlining tree_inlining;
 386
 387   struct lang_hooks_for_callgraph callgraph;
 388
 389   struct lang_hooks_for_tree_dump tree_dump;
 390
 391   struct lang_hooks_for_decls decls;
 392
 393   struct lang_hooks_for_types types;
 394
 395   /* Perform language-specific gimplification on the argument.  Returns an
 396      enum gimplify_status, though we can't see that type here.  */
 397   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 398
 399   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 400      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 401   tree (*fold_obj_type_ref) (tree, tree);
 402
 403   /* Do language specific processing in the builtin function DECL  */
 404   tree (*builtin_function) (tree decl);
 405
 406   /* Like builtin_function, but make sure the scope is the external scope.
 407      This is used to delay putting in back end builtin functions until the ISA
 408      that defines the builtin is declared via function specific target options,
 409      which can save memory for machines like the x86_64 that have multiple
 410      ISAs.  If this points to the same function as builtin_function, the
 411      backend must add all of the builtins at program initialization time.  */
 412   tree (*builtin_function_ext_scope) (tree decl);
 413
 414   /* Used to set up the tree_contains_structure array for a frontend. */
 415   void (*init_ts) (void);
 416
 417   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 418      to a contained expression or DECL, possibly updating *TC or *SE
 419      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 420   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 421
 422   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 423      and langhooks.c accordingly.  */
 424 };
 425
 426 /* Each front end provides its own.  */
 427 extern const struct lang_hooks lang_hooks;
 428 extern tree add_builtin_function (const char *name, tree type,
 429                                   int function_code, enum built_in_class cl,
 430                                   const char *library_name,
 431                                   tree attrs);
 432
 433 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 434                                             int function_code,
 435                                             enum built_in_class cl,
 436                                             const char *library_name,
 437                                             tree attrs);
 438
 439 #endif /* GCC_LANG_HOOKS_H */