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   /* Returns the TREE_VEC of elements of a given generic argument pack.  */
  95   tree (*get_argument_pack_elems) (const_tree);
  96
  97   /* Given a type, apply default promotions to unnamed function
  98      arguments and return the new type.  Return the same type if no
  99      change.  Required by any language that supports variadic
 100      arguments.  The default hook dies.  */
 101   tree (*type_promotes_to) (tree);
 102
 103   /* Register TYPE as a builtin type with the indicated NAME.  The
 104      TYPE is placed in the outermost lexical scope.  The semantics
 105      should be analogous to:
 106
 107        typedef TYPE NAME;
 108
 109      in C.  The default hook ignores the declaration.  */
 110   void (*register_builtin_type) (tree, const char *);
 111
 112   /* This routine is called in tree.c to print an error message for
 113      invalid use of an incomplete type.  VALUE is the expression that
 114      was used (or 0 if that isn't known) and TYPE is the type that was
 115      invalid.  */
 116   void (*incomplete_type_error) (const_tree value, const_tree type);
 117
 118   /* Called from assign_temp to return the maximum size, if there is one,
 119      for a type.  */
 120   tree (*max_size) (const_tree);
 121
 122   /* Register language specific type size variables as potentially OpenMP
 123      firstprivate variables.  */
 124   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 125
 126   /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
 127      Called only after doing all language independent checks.
 128      At present, this function is only called when both TYPE1 and TYPE2 are
 129      FUNCTION_TYPEs.  */
 130   bool (*type_hash_eq) (const_tree, const_tree);
 131
 132   /* Return TRUE if TYPE uses a hidden descriptor and fills in information
 133      for the debugger about the array bounds, strides, etc.  */
 134   bool (*get_array_descr_info) (const_tree, struct array_descr_info *);
 135
 136   /* Fill in information for the debugger about the bounds of TYPE.  */
 137   void (*get_subrange_bounds) (const_tree, tree *, tree *);
 138
 139   /* If we requested a pointer to a vector, build up the pointers that
 140      we stripped off while looking for the inner type.  Similarly for
 141      return values from functions.  The argument TYPE is the top of the
 142      chain, and BOTTOM is the new type which we will point to.  */
 143   tree (*reconstruct_complex_type) (tree, tree);
 144
 145   /* Nonzero if types that are identical are to be hashed so that only
 146      one copy is kept.  If a language requires unique types for each
 147      user-specified type, such as Ada, this should be set to TRUE.  */
 148   bool hash_types;
 149 };
 150
 151 /* Language hooks related to decls and the symbol table.  */
 152
 153 struct lang_hooks_for_decls
 154 {
 155   /* Returns nonzero if we are in the global binding level.  Ada
 156      returns -1 for an undocumented reason used in stor-layout.c.  */
 157   int (*global_bindings_p) (void);
 158
 159   /* Function to add a decl to the current scope level.  Takes one
 160      argument, a decl to add.  Returns that decl, or, if the same
 161      symbol is already declared, may return a different decl for that
 162      name.  */
 163   tree (*pushdecl) (tree);
 164
 165   /* Returns the chain of decls so far in the current scope level.  */
 166   tree (*getdecls) (void);
 167
 168   /* Returns true if DECL is explicit member function.  */
 169   bool (*function_decl_explicit_p) (tree);
 170
 171   /* Returns True if the parameter is a generic parameter decl
 172      of a generic type, e.g a template template parameter for the C++ FE.  */
 173   bool (*generic_generic_parameter_decl_p) (const_tree);
 174
 175   /* Returns true when we should warn for an unused global DECL.
 176      We will already have checked that it has static binding.  */
 177   bool (*warn_unused_global) (const_tree);
 178
 179   /* Obtain a list of globals and do final output on them at end
 180      of compilation */
 181   void (*final_write_globals) (void);
 182
 183   /* True if this decl may be called via a sibcall.  */
 184   bool (*ok_for_sibcall) (const_tree);
 185
 186   /* True if OpenMP should privatize what this DECL points to rather
 187      than the DECL itself.  */
 188   bool (*omp_privatize_by_reference) (const_tree);
 189
 190   /* Return sharing kind if OpenMP sharing attribute of DECL is
 191      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 192   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 193
 194   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 195      disregarded in OpenMP construct, because it is going to be
 196      remapped during OpenMP lowering.  SHARED is true if DECL
 197      is going to be shared, false if it is going to be privatized.  */
 198   bool (*omp_disregard_value_expr) (tree, bool);
 199
 200   /* Return true if DECL that is shared iff SHARED is true should
 201      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 202   bool (*omp_private_debug_clause) (tree, bool);
 203
 204   /* Return true if DECL in private clause needs
 205      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 206   bool (*omp_private_outer_ref) (tree);
 207
 208   /* Build and return code for a default constructor for DECL in
 209      response to CLAUSE.  OUTER is corresponding outer region's
 210      variable if needed.  Return NULL if nothing to be done.  */
 211   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 212
 213   /* Build and return code for a copy constructor from SRC to DST.  */
 214   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 215
 216   /* Similarly, except use an assignment operator instead.  */
 217   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 218
 219   /* Build and return code destructing DECL.  Return NULL if nothing
 220      to be done.  */
 221   tree (*omp_clause_dtor) (tree clause, tree decl);
 222
 223   /* Do language specific checking on an implicitly determined clause.  */
 224   void (*omp_finish_clause) (tree clause);
 225 };
 226
 227 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 228
 229 struct lang_hooks
 230 {
 231   /* String identifying the front end.  e.g. "GNU C++".  */
 232   const char *name;
 233
 234   /* sizeof (struct lang_identifier), so make_node () creates
 235      identifier nodes long enough for the language-specific slots.  */
 236   size_t identifier_size;
 237
 238   /* Determines the size of any language-specific tcc_constant or
 239      tcc_exceptional nodes.  Since it is called from make_node, the
 240      only information available is the tree code.  Expected to die
 241      on unrecognized codes.  */
 242   size_t (*tree_size) (enum tree_code);
 243
 244   /* The first callback made to the front end, for simple
 245      initialization needed before any calls to handle_option.  Return
 246      the language mask to filter the switch array with.  */
 247   unsigned int (*init_options) (unsigned int argc, const char **argv);
 248
 249   /* Callback used to perform language-specific initialization for the
 250      global diagnostic context structure.  */
 251   void (*initialize_diagnostics) (struct diagnostic_context *);
 252
 253   /* Handle the switch CODE, which has real type enum opt_code from
 254      options.h.  If the switch takes an argument, it is passed in ARG
 255      which points to permanent storage.  The handler is responsible for
 256      checking whether ARG is NULL, which indicates that no argument
 257      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 258      for the positive and negative forms respectively.
 259
 260      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 261      valid and should not be treated as language-independent too.  */
 262   int (*handle_option) (size_t code, const char *arg, int value);
 263
 264   /* Return false to use the default complaint about a missing
 265      argument, otherwise output a complaint and return true.  */
 266   bool (*missing_argument) (const char *opt, size_t code);
 267
 268   /* Called when all command line options have been parsed to allow
 269      further processing and initialization
 270
 271      Should return true to indicate that a compiler back-end is
 272      not required, such as with the -E option.
 273
 274      If errorcount is nonzero after this call the compiler exits
 275      immediately and the finish hook is not called.  */
 276   bool (*post_options) (const char **);
 277
 278   /* Called after post_options to initialize the front end.  Return
 279      false to indicate that no further compilation be performed, in
 280      which case the finish hook is called immediately.  */
 281   bool (*init) (void);
 282
 283   /* Called at the end of compilation, as a finalizer.  */
 284   void (*finish) (void);
 285
 286   /* Parses the entire file.  The argument is nonzero to cause bison
 287      parsers to dump debugging information during parsing.  */
 288   void (*parse_file) (int);
 289
 290   /* Determines if it's ok for a function to have no noreturn attribute.  */
 291   bool (*missing_noreturn_ok_p) (tree);
 292
 293   /* Called to obtain the alias set to be used for an expression or type.
 294      Returns -1 if the language does nothing special for it.  */
 295   alias_set_type (*get_alias_set) (tree);
 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   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 302      DECL_NODE with a newly GC-allocated copy.  */
 303   void (*dup_lang_specific_decl) (tree);
 304
 305   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 306      thing that the assembler should talk about, set
 307      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 308      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 309      assembler does not talk about it.  */
 310   void (*set_decl_assembler_name) (tree);
 311
 312   /* The front end can add its own statistics to -fmem-report with
 313      this hook.  It should output to stderr.  */
 314   void (*print_statistics) (void);
 315
 316   /* Called by print_tree when there is a tree of class tcc_exceptional
 317      that it doesn't know how to display.  */
 318   lang_print_tree_hook print_xnode;
 319
 320   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 321      and IDENTIFIER_NODE nodes.  */
 322   lang_print_tree_hook print_decl;
 323   lang_print_tree_hook print_type;
 324   lang_print_tree_hook print_identifier;
 325
 326   /* Computes the name to use to print a declaration.  DECL is the
 327      non-NULL declaration in question.  VERBOSITY determines what
 328      information will be printed: 0: DECL_NAME, demangled as
 329      necessary.  1: and scope information.  2: and any other
 330      information that might be interesting, such as function parameter
 331      types in C++.  The name is in the internal character set and
 332      needs to be converted to the locale character set of diagnostics,
 333      or to the execution character set for strings such as
 334      __PRETTY_FUNCTION__.  */
 335   const char *(*decl_printable_name) (tree decl, int verbosity);
 336
 337   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 338      information will be printed: 0: DECL_NAME, demangled as
 339      necessary.  1: and scope information.  */
 340   const char *(*dwarf_name) (tree, int verbosity);
 341
 342   /* This compares two types for equivalence ("compatible" in C-based languages).
 343      This routine should only return 1 if it is sure.  It should not be used
 344      in contexts where erroneously returning 0 causes problems.  */
 345   int (*types_compatible_p) (tree x, tree y);
 346
 347   /* Called by report_error_function to print out function name.  */
 348   void (*print_error_function) (struct diagnostic_context *, const char *,
 349                                 struct diagnostic_info *);
 350
 351   /* Called from expr_size to calculate the size of the value of an
 352      expression in a language-dependent way.  Returns a tree for the size
 353      in bytes.  A frontend can call lhd_expr_size to get the default
 354      semantics in cases that it doesn't want to handle specially.  */
 355   tree (*expr_size) (const_tree);
 356
 357   /* Convert a character from the host's to the target's character
 358      set.  The character should be in what C calls the "basic source
 359      character set" (roughly, the set of characters defined by plain
 360      old ASCII).  The default is to return the character unchanged,
 361      which is correct in most circumstances.  Note that both argument
 362      and result should be sign-extended under -fsigned-char,
 363      zero-extended under -fno-signed-char.  */
 364   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 365
 366   /* Pointers to machine-independent attribute tables, for front ends
 367      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 368      table of attributes specific to the language, a table of
 369      attributes common to two or more languages (to allow easy
 370      sharing), and a table of attributes for checking formats.  */
 371   const struct attribute_spec *attribute_table;
 372   const struct attribute_spec *common_attribute_table;
 373   const struct attribute_spec *format_attribute_table;
 374
 375   struct lang_hooks_for_tree_inlining tree_inlining;
 376
 377   struct lang_hooks_for_callgraph callgraph;
 378
 379   struct lang_hooks_for_tree_dump tree_dump;
 380
 381   struct lang_hooks_for_decls decls;
 382
 383   struct lang_hooks_for_types types;
 384
 385   /* Retuns the generic parameters of an instantiation of
 386      a generic type or decl, e.g. C++ template instantiation.  */
 387   tree (*get_innermost_generic_parms) (const_tree);
 388
 389   /* Returns the TREE_VEC of arguments of an instantiation
 390      of a generic type of decl, e.g. C++ template instantiation.  */
 391   tree (*get_innermost_generic_args) (const_tree);
 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 */