gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007
   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 /* A print hook for print_tree ().  */
  32 typedef void (*lang_print_tree_hook) (FILE *, tree, int indent);
  33
  34 /* The following hooks are documented in langhooks.c.  Must not be
  35    NULL.  */
  36
  37 struct lang_hooks_for_tree_inlining
  38 {
  39   bool (*var_mod_type_p) (tree, tree);
  40 };
  41
  42 struct lang_hooks_for_callgraph
  43 {
  44   /* The node passed is a language-specific tree node.  If its contents
  45      are relevant to use of other declarations, mark them.  */
  46   tree (*analyze_expr) (tree *, int *, tree);
  47
  48   /* Emmit thunks associated to function.  */
  49   void (*emit_associated_thunks) (tree);
  50 };
  51
  52 /* Lang hooks for management of language-specific data or status
  53    when entering / leaving functions etc.  */
  54 struct lang_hooks_for_functions
  55 {
  56   /* Called when entering a function.  */
  57   void (*init) (struct function *);
  58
  59   /* Called when leaving a function.  */
  60   void (*final) (struct function *);
  61
  62   /* Called when entering a nested function.  */
  63   void (*enter_nested) (struct function *);
  64
  65   /* Called when leaving a nested function.  */
  66   void (*leave_nested) (struct function *);
  67
  68   /* Determines if it's ok for a function to have no noreturn attribute.  */
  69   bool (*missing_noreturn_ok_p) (tree);
  70 };
  71
  72 /* The following hooks are used by tree-dump.c.  */
  73
  74 struct lang_hooks_for_tree_dump
  75 {
  76   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  77      does not want the usual dumping of the second argument.  */
  78   bool (*dump_tree) (void *, tree);
  79
  80   /* Determine type qualifiers in a language-specific way.  */
  81   int (*type_quals) (const_tree);
  82 };
  83
  84 /* Hooks related to types.  */
  85
  86 struct lang_hooks_for_types
  87 {
  88   /* Return a new type (with the indicated CODE), doing whatever
  89      language-specific processing is required.  */
  90   tree (*make_type) (enum tree_code);
  91
  92   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  93      mode.  */
  94   tree (*type_for_mode) (enum machine_mode, int);
  95
  96   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
  97      integer type with at least that precision.  */
  98   tree (*type_for_size) (unsigned, int);
  99
 100   /* True if the type is an instantiation of a generic type,
 101      e.g. C++ template implicit specializations.  */
 102   bool (*generic_p) (const_tree);
 103
 104   /* Given a type, apply default promotions to unnamed function
 105      arguments and return the new type.  Return the same type if no
 106      change.  Required by any language that supports variadic
 107      arguments.  The default hook dies.  */
 108   tree (*type_promotes_to) (tree);
 109
 110   /* Register TYPE as a builtin type with the indicated NAME.  The
 111      TYPE is placed in the outermost lexical scope.  The semantics
 112      should be analogous to:
 113
 114        typedef TYPE NAME;
 115
 116      in C.  The default hook ignores the declaration.  */
 117   void (*register_builtin_type) (tree, const char *);
 118
 119   /* This routine is called in tree.c to print an error message for
 120      invalid use of an incomplete type.  VALUE is the expression that
 121      was used (or 0 if that isn't known) and TYPE is the type that was
 122      invalid.  */
 123   void (*incomplete_type_error) (const_tree value, const_tree type);
 124
 125   /* Called from assign_temp to return the maximum size, if there is one,
 126      for a type.  */
 127   tree (*max_size) (const_tree);
 128
 129   /* Register language specific type size variables as potentially OpenMP
 130      firstprivate variables.  */
 131   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 132
 133   /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
 134      Called only after doing all language independent checks.
 135      At present, this function is only called when both TYPE1 and TYPE2 are
 136      FUNCTION_TYPEs.  */
 137   bool (*type_hash_eq) (const_tree, const_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   /* Insert BLOCK at the end of the list of subblocks of the
 154      current binding level.  This is used when a BIND_EXPR is expanded,
 155      to handle the BLOCK node inside the BIND_EXPR.  */
 156   void (*insert_block) (tree);
 157
 158   /* Function to add a decl to the current scope level.  Takes one
 159      argument, a decl to add.  Returns that decl, or, if the same
 160      symbol is already declared, may return a different decl for that
 161      name.  */
 162   tree (*pushdecl) (tree);
 163
 164   /* Returns the chain of decls so far in the current scope level.  */
 165   tree (*getdecls) (void);
 166
 167   /* Returns true when we should warn for an unused global DECL.
 168      We will already have checked that it has static binding.  */
 169   bool (*warn_unused_global) (const_tree);
 170
 171   /* Obtain a list of globals and do final output on them at end
 172      of compilation */
 173   void (*final_write_globals) (void);
 174
 175   /* True if this decl may be called via a sibcall.  */
 176   bool (*ok_for_sibcall) (const_tree);
 177
 178   /* Return the COMDAT group into which this DECL should be placed.
 179      It is known that the DECL belongs in *some* COMDAT group when
 180      this hook is called.  The return value will be used immediately,
 181      but not explicitly deallocated, so implementations should not use
 182      xmalloc to allocate the string returned.  (Typically, the return
 183      value will be the string already stored in an
 184      IDENTIFIER_NODE.)  */
 185   const char * (*comdat_group) (tree);
 186
 187   /* True if OpenMP should privatize what this DECL points to rather
 188      than the DECL itself.  */
 189   bool (*omp_privatize_by_reference) (const_tree);
 190
 191   /* Return sharing kind if OpenMP sharing attribute of DECL is
 192      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 193   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 194
 195   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 196      disregarded in OpenMP construct, because it is going to be
 197      remapped during OpenMP lowering.  SHARED is true if DECL
 198      is going to be shared, false if it is going to be privatized.  */
 199   bool (*omp_disregard_value_expr) (tree, bool);
 200
 201   /* Return true if DECL that is shared iff SHARED is true should
 202      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 203   bool (*omp_private_debug_clause) (tree, bool);
 204
 205   /* Build and return code for a default constructor for DECL in
 206      response to CLAUSE.  Return NULL if nothing to be done.  */
 207   tree (*omp_clause_default_ctor) (tree clause, tree decl);
 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
 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   /* Called immediately after parsing to clear the binding stack.  */
 284   void (*clear_binding_stack) (void);
 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   /* Called with an expression that is to be processed as a constant.
 291      Returns either the same expression or a language-independent
 292      constant equivalent to its input.  */
 293   tree (*expand_constant) (tree);
 294
 295   /* Called by expand_expr for language-specific tree codes.
 296      Fourth argument is actually an enum expand_modifier.  */
 297   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 298
 299   /* Called by expand_expr to generate the definition of a decl.  Returns
 300      1 if handled, 0 otherwise.  */
 301   int (*expand_decl) (tree);
 302
 303   /* Function to finish handling an incomplete decl at the end of
 304      compilation.  Default hook is does nothing.  */
 305   void (*finish_incomplete_decl) (tree);
 306
 307   /* Mark EXP saying that we need to be able to take the address of
 308      it; it should not be allocated in a register.  Return true if
 309      successful.  */
 310   bool (*mark_addressable) (tree);
 311
 312   /* Hook called by staticp for language-specific tree codes.  */
 313   tree (*staticp) (tree);
 314
 315   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 316      DECL_NODE with a newly GC-allocated copy.  */
 317   void (*dup_lang_specific_decl) (tree);
 318
 319   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 320      thing that the assembler should talk about, set
 321      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 322      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 323      assembler does not talk about it.  */
 324   void (*set_decl_assembler_name) (tree);
 325
 326   /* Nonzero if operations on types narrower than their mode should
 327      have their results reduced to the precision of the type.  */
 328   bool reduce_bit_field_operations;
 329
 330   /* Nonzero if this front end does not generate a dummy BLOCK between
 331      the outermost scope of the function and the FUNCTION_DECL.  See
 332      is_body_block in stmt.c, and its callers.  */
 333   bool no_body_blocks;
 334
 335   /* The front end can add its own statistics to -fmem-report with
 336      this hook.  It should output to stderr.  */
 337   void (*print_statistics) (void);
 338
 339   /* Called by print_tree when there is a tree of class tcc_exceptional
 340      that it doesn't know how to display.  */
 341   lang_print_tree_hook print_xnode;
 342
 343   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 344      and IDENTIFIER_NODE nodes.  */
 345   lang_print_tree_hook print_decl;
 346   lang_print_tree_hook print_type;
 347   lang_print_tree_hook print_identifier;
 348
 349   /* Computes the name to use to print a declaration.  DECL is the
 350      non-NULL declaration in question.  VERBOSITY determines what
 351      information will be printed: 0: DECL_NAME, demangled as
 352      necessary.  1: and scope information.  2: and any other
 353      information that might be interesting, such as function parameter
 354      types in C++.  */
 355   const char *(*decl_printable_name) (tree decl, int verbosity);
 356
 357   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 358      information will be printed: 0: DECL_NAME, demangled as
 359      necessary.  1: and scope information.  */
 360   const char *(*dwarf_name) (tree, int verbosity);
 361
 362   /* This compares two types for equivalence ("compatible" in C-based languages).
 363      This routine should only return 1 if it is sure.  It should not be used
 364      in contexts where erroneously returning 0 causes problems.  */
 365   int (*types_compatible_p) (tree x, tree y);
 366
 367   /* Given a CALL_EXPR, return a function decl that is its target.  */
 368   tree (*lang_get_callee_fndecl) (const_tree);
 369
 370   /* Called by report_error_function to print out function name.  */
 371   void (*print_error_function) (struct diagnostic_context *, const char *,
 372                                 struct diagnostic_info *);
 373
 374   /* Called from expr_size to calculate the size of the value of an
 375      expression in a language-dependent way.  Returns a tree for the size
 376      in bytes.  A frontend can call lhd_expr_size to get the default
 377      semantics in cases that it doesn't want to handle specially.  */
 378   tree (*expr_size) (const_tree);
 379
 380   /* Convert a character from the host's to the target's character
 381      set.  The character should be in what C calls the "basic source
 382      character set" (roughly, the set of characters defined by plain
 383      old ASCII).  The default is to return the character unchanged,
 384      which is correct in most circumstances.  Note that both argument
 385      and result should be sign-extended under -fsigned-char,
 386      zero-extended under -fno-signed-char.  */
 387   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 388
 389   /* Pointers to machine-independent attribute tables, for front ends
 390      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 391      table of attributes specific to the language, a table of
 392      attributes common to two or more languages (to allow easy
 393      sharing), and a table of attributes for checking formats.  */
 394   const struct attribute_spec *attribute_table;
 395   const struct attribute_spec *common_attribute_table;
 396   const struct attribute_spec *format_attribute_table;
 397
 398   /* Function-related language hooks.  */
 399   struct lang_hooks_for_functions function;
 400
 401   struct lang_hooks_for_tree_inlining tree_inlining;
 402
 403   struct lang_hooks_for_callgraph callgraph;
 404
 405   struct lang_hooks_for_tree_dump tree_dump;
 406
 407   struct lang_hooks_for_decls decls;
 408
 409   struct lang_hooks_for_types types;
 410
 411   /* Perform language-specific gimplification on the argument.  Returns an
 412      enum gimplify_status, though we can't see that type here.  */
 413   int (*gimplify_expr) (tree *, tree *, tree *);
 414
 415   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 416      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 417   tree (*fold_obj_type_ref) (tree, tree);
 418
 419   /* Do language specific processing in the builtin function DECL  */
 420   tree (*builtin_function) (tree decl);
 421
 422   /* Used to set up the tree_contains_structure array for a frontend. */
 423   void (*init_ts) (void);
 424
 425   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 426      to a contained expression or DECL, possibly updating *TC, *TI or
 427      *SE if in the process TREE_CONSTANT, TREE_INVARIANT or
 428      TREE_SIDE_EFFECTS need updating.  */
 429   tree (*expr_to_decl) (tree expr, bool *tc, bool *ti, bool *se);
 430
 431   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 432      and langhooks.c accordingly.  */
 433 };
 434
 435 /* Each front end provides its own.  */
 436 extern const struct lang_hooks lang_hooks;
 437 extern tree add_builtin_function (const char *name, tree type,
 438                                   int function_code, enum built_in_class cl,
 439                                   const char *library_name,
 440                                   tree attrs);
 441
 442 #endif /* GCC_LANG_HOOKS_H */