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