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
  28 struct gimplify_omp_ctx;
  29
  30 /* A print hook for print_tree ().  */
  31 typedef void (*lang_print_tree_hook) (FILE *, tree, int indent);
  32
  33 /* The following hooks are documented in langhooks.c.  Must not be
  34    NULL.  */
  35
  36 struct lang_hooks_for_tree_inlining
  37 {
  38   bool (*var_mod_type_p) (tree, tree);
  39 };
  40
  41 struct lang_hooks_for_callgraph
  42 {
  43   /* The node passed is a language-specific tree node.  If its contents
  44      are relevant to use of other declarations, mark them.  */
  45   tree (*analyze_expr) (tree *, int *, tree);
  46
  47   /* Emmit thunks associated to function.  */
  48   void (*emit_associated_thunks) (tree);
  49 };
  50
  51 /* Lang hooks for management of language-specific data or status
  52    when entering / leaving functions etc.  */
  53 struct lang_hooks_for_functions
  54 {
  55   /* Called when entering a function.  */
  56   void (*init) (struct function *);
  57
  58   /* Called when leaving a function.  */
  59   void (*final) (struct function *);
  60
  61   /* Called when entering a nested function.  */
  62   void (*enter_nested) (struct function *);
  63
  64   /* Called when leaving a nested function.  */
  65   void (*leave_nested) (struct function *);
  66
  67   /* Determines if it's ok for a function to have no noreturn attribute.  */
  68   bool (*missing_noreturn_ok_p) (tree);
  69 };
  70
  71 /* The following hooks are used by tree-dump.c.  */
  72
  73 struct lang_hooks_for_tree_dump
  74 {
  75   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  76      does not want the usual dumping of the second argument.  */
  77   bool (*dump_tree) (void *, tree);
  78
  79   /* Determine type qualifiers in a language-specific way.  */
  80   int (*type_quals) (const_tree);
  81 };
  82
  83 /* Hooks related to types.  */
  84
  85 struct lang_hooks_for_types
  86 {
  87   /* Return a new type (with the indicated CODE), doing whatever
  88      language-specific processing is required.  */
  89   tree (*make_type) (enum tree_code);
  90
  91   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  92      mode.  */
  93   tree (*type_for_mode) (enum machine_mode, int);
  94
  95   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
  96      integer type with at least that precision.  */
  97   tree (*type_for_size) (unsigned, int);
  98
  99   /* True if the type is an instantiation of a generic type,
 100      e.g. C++ template implicit specializations.  */
 101   bool (*generic_p) (const_tree);
 102
 103   /* Given a type, apply default promotions to unnamed function
 104      arguments and return the new type.  Return the same type if no
 105      change.  Required by any language that supports variadic
 106      arguments.  The default hook dies.  */
 107   tree (*type_promotes_to) (tree);
 108
 109   /* Register TYPE as a builtin type with the indicated NAME.  The
 110      TYPE is placed in the outermost lexical scope.  The semantics
 111      should be analogous to:
 112
 113        typedef TYPE NAME;
 114
 115      in C.  The default hook ignores the declaration.  */
 116   void (*register_builtin_type) (tree, const char *);
 117
 118   /* This routine is called in tree.c to print an error message for
 119      invalid use of an incomplete type.  VALUE is the expression that
 120      was used (or 0 if that isn't known) and TYPE is the type that was
 121      invalid.  */
 122   void (*incomplete_type_error) (const_tree value, const_tree type);
 123
 124   /* Called from assign_temp to return the maximum size, if there is one,
 125      for a type.  */
 126   tree (*max_size) (const_tree);
 127
 128   /* Register language specific type size variables as potentially OpenMP
 129      firstprivate variables.  */
 130   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 131
 132   /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
 133      Called only after doing all language independent checks.
 134      At present, this function is only called when both TYPE1 and TYPE2 are
 135      FUNCTION_TYPEs.  */
 136   bool (*type_hash_eq) (const_tree, const_tree);
 137
 138   /* Nonzero if types that are identical are to be hashed so that only
 139      one copy is kept.  If a language requires unique types for each
 140      user-specified type, such as Ada, this should be set to TRUE.  */
 141   bool hash_types;
 142 };
 143
 144 /* Language hooks related to decls and the symbol table.  */
 145
 146 struct lang_hooks_for_decls
 147 {
 148   /* Returns nonzero if we are in the global binding level.  Ada
 149      returns -1 for an undocumented reason used in stor-layout.c.  */
 150   int (*global_bindings_p) (void);
 151
 152   /* Insert BLOCK at the end of the list of subblocks of the
 153      current binding level.  This is used when a BIND_EXPR is expanded,
 154      to handle the BLOCK node inside the BIND_EXPR.  */
 155   void (*insert_block) (tree);
 156
 157   /* Function to add a decl to the current scope level.  Takes one
 158      argument, a decl to add.  Returns that decl, or, if the same
 159      symbol is already declared, may return a different decl for that
 160      name.  */
 161   tree (*pushdecl) (tree);
 162
 163   /* Returns the chain of decls so far in the current scope level.  */
 164   tree (*getdecls) (void);
 165
 166   /* Returns true when we should warn for an unused global DECL.
 167      We will already have checked that it has static binding.  */
 168   bool (*warn_unused_global) (const_tree);
 169
 170   /* Obtain a list of globals and do final output on them at end
 171      of compilation */
 172   void (*final_write_globals) (void);
 173
 174   /* True if this decl may be called via a sibcall.  */
 175   bool (*ok_for_sibcall) (const_tree);
 176
 177   /* Return the COMDAT group into which this DECL should be placed.
 178      It is known that the DECL belongs in *some* COMDAT group when
 179      this hook is called.  The return value will be used immediately,
 180      but not explicitly deallocated, so implementations should not use
 181      xmalloc to allocate the string returned.  (Typically, the return
 182      value will be the string already stored in an
 183      IDENTIFIER_NODE.)  */
 184   const char * (*comdat_group) (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   /* Build and return code for a default constructor for DECL in
 205      response to CLAUSE.  Return NULL if nothing to be done.  */
 206   tree (*omp_clause_default_ctor) (tree clause, tree decl);
 207
 208   /* Build and return code for a copy constructor from SRC to DST.  */
 209   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 210
 211   /* Similarly, except use an assignment operator instead.  */
 212   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 213
 214   /* Build and return code destructing DECL.  Return NULL if nothing
 215      to be done.  */
 216   tree (*omp_clause_dtor) (tree clause, tree decl);
 217 };
 218
 219 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 220
 221 struct lang_hooks
 222 {
 223   /* String identifying the front end.  e.g. "GNU C++".  */
 224   const char *name;
 225
 226   /* sizeof (struct lang_identifier), so make_node () creates
 227      identifier nodes long enough for the language-specific slots.  */
 228   size_t identifier_size;
 229
 230   /* Determines the size of any language-specific tcc_constant or
 231      tcc_exceptional nodes.  Since it is called from make_node, the
 232      only information available is the tree code.  Expected to die
 233      on unrecognized codes.  */
 234   size_t (*tree_size) (enum tree_code);
 235
 236   /* The first callback made to the front end, for simple
 237      initialization needed before any calls to handle_option.  Return
 238      the language mask to filter the switch array with.  */
 239   unsigned int (*init_options) (unsigned int argc, const char **argv);
 240
 241   /* Callback used to perform language-specific initialization for the
 242      global diagnostic context structure.  */
 243   void (*initialize_diagnostics) (struct diagnostic_context *);
 244
 245   /* Handle the switch CODE, which has real type enum opt_code from
 246      options.h.  If the switch takes an argument, it is passed in ARG
 247      which points to permanent storage.  The handler is responsible for
 248      checking whether ARG is NULL, which indicates that no argument
 249      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 250      for the positive and negative forms respectively.
 251
 252      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 253      valid and should not be treated as language-independent too.  */
 254   int (*handle_option) (size_t code, const char *arg, int value);
 255
 256   /* Return false to use the default complaint about a missing
 257      argument, otherwise output a complaint and return true.  */
 258   bool (*missing_argument) (const char *opt, size_t code);
 259
 260   /* Called when all command line options have been parsed to allow
 261      further processing and initialization
 262
 263      Should return true to indicate that a compiler back-end is
 264      not required, such as with the -E option.
 265
 266      If errorcount is nonzero after this call the compiler exits
 267      immediately and the finish hook is not called.  */
 268   bool (*post_options) (const char **);
 269
 270   /* Called after post_options to initialize the front end.  Return
 271      false to indicate that no further compilation be performed, in
 272      which case the finish hook is called immediately.  */
 273   bool (*init) (void);
 274
 275   /* Called at the end of compilation, as a finalizer.  */
 276   void (*finish) (void);
 277
 278   /* Parses the entire file.  The argument is nonzero to cause bison
 279      parsers to dump debugging information during parsing.  */
 280   void (*parse_file) (int);
 281
 282   /* Called immediately after parsing to clear the binding stack.  */
 283   void (*clear_binding_stack) (void);
 284
 285   /* Called to obtain the alias set to be used for an expression or type.
 286      Returns -1 if the language does nothing special for it.  */
 287   alias_set_type (*get_alias_set) (tree);
 288
 289   /* Called with an expression that is to be processed as a constant.
 290      Returns either the same expression or a language-independent
 291      constant equivalent to its input.  */
 292   tree (*expand_constant) (tree);
 293
 294   /* Called by expand_expr for language-specific tree codes.
 295      Fourth argument is actually an enum expand_modifier.  */
 296   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 297
 298   /* Called by expand_expr to generate the definition of a decl.  Returns
 299      1 if handled, 0 otherwise.  */
 300   int (*expand_decl) (tree);
 301
 302   /* Function to finish handling an incomplete decl at the end of
 303      compilation.  Default hook is does nothing.  */
 304   void (*finish_incomplete_decl) (tree);
 305
 306   /* Mark EXP saying that we need to be able to take the address of
 307      it; it should not be allocated in a register.  Return true if
 308      successful.  */
 309   bool (*mark_addressable) (tree);
 310
 311   /* Hook called by staticp for language-specific tree codes.  */
 312   tree (*staticp) (tree);
 313
 314   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 315      DECL_NODE with a newly GC-allocated copy.  */
 316   void (*dup_lang_specific_decl) (tree);
 317
 318   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 319      thing that the assembler should talk about, set
 320      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 321      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 322      assembler does not talk about it.  */
 323   void (*set_decl_assembler_name) (tree);
 324
 325   /* Nonzero if operations on types narrower than their mode should
 326      have their results reduced to the precision of the type.  */
 327   bool reduce_bit_field_operations;
 328
 329   /* Nonzero if this front end does not generate a dummy BLOCK between
 330      the outermost scope of the function and the FUNCTION_DECL.  See
 331      is_body_block in stmt.c, and its callers.  */
 332   bool no_body_blocks;
 333
 334   /* The front end can add its own statistics to -fmem-report with
 335      this hook.  It should output to stderr.  */
 336   void (*print_statistics) (void);
 337
 338   /* Called by print_tree when there is a tree of class tcc_exceptional
 339      that it doesn't know how to display.  */
 340   lang_print_tree_hook print_xnode;
 341
 342   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 343      and IDENTIFIER_NODE nodes.  */
 344   lang_print_tree_hook print_decl;
 345   lang_print_tree_hook print_type;
 346   lang_print_tree_hook print_identifier;
 347
 348   /* Computes the name to use to print a declaration.  DECL is the
 349      non-NULL declaration in question.  VERBOSITY determines what
 350      information will be printed: 0: DECL_NAME, demangled as
 351      necessary.  1: and scope information.  2: and any other
 352      information that might be interesting, such as function parameter
 353      types in C++.  */
 354   const char *(*decl_printable_name) (tree decl, int verbosity);
 355
 356   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 357      information will be printed: 0: DECL_NAME, demangled as
 358      necessary.  1: and scope information.  */
 359   const char *(*dwarf_name) (tree, int verbosity);
 360
 361   /* This compares two types for equivalence ("compatible" in C-based languages).
 362      This routine should only return 1 if it is sure.  It should not be used
 363      in contexts where erroneously returning 0 causes problems.  */
 364   int (*types_compatible_p) (tree x, tree y);
 365
 366   /* Given a CALL_EXPR, return a function decl that is its target.  */
 367   tree (*lang_get_callee_fndecl) (const_tree);
 368
 369   /* Called by report_error_function to print out function name.  */
 370   void (*print_error_function) (struct diagnostic_context *, const char *);
 371
 372   /* Called from expr_size to calculate the size of the value of an
 373      expression in a language-dependent way.  Returns a tree for the size
 374      in bytes.  A frontend can call lhd_expr_size to get the default
 375      semantics in cases that it doesn't want to handle specially.  */
 376   tree (*expr_size) (const_tree);
 377
 378   /* Convert a character from the host's to the target's character
 379      set.  The character should be in what C calls the "basic source
 380      character set" (roughly, the set of characters defined by plain
 381      old ASCII).  The default is to return the character unchanged,
 382      which is correct in most circumstances.  Note that both argument
 383      and result should be sign-extended under -fsigned-char,
 384      zero-extended under -fno-signed-char.  */
 385   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 386
 387   /* Pointers to machine-independent attribute tables, for front ends
 388      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 389      table of attributes specific to the language, a table of
 390      attributes common to two or more languages (to allow easy
 391      sharing), and a table of attributes for checking formats.  */
 392   const struct attribute_spec *attribute_table;
 393   const struct attribute_spec *common_attribute_table;
 394   const struct attribute_spec *format_attribute_table;
 395
 396   /* Function-related language hooks.  */
 397   struct lang_hooks_for_functions function;
 398
 399   struct lang_hooks_for_tree_inlining tree_inlining;
 400
 401   struct lang_hooks_for_callgraph callgraph;
 402
 403   struct lang_hooks_for_tree_dump tree_dump;
 404
 405   struct lang_hooks_for_decls decls;
 406
 407   struct lang_hooks_for_types types;
 408
 409   /* Perform language-specific gimplification on the argument.  Returns an
 410      enum gimplify_status, though we can't see that type here.  */
 411   int (*gimplify_expr) (tree *, tree *, tree *);
 412
 413   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 414      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 415   tree (*fold_obj_type_ref) (tree, tree);
 416
 417   /* Do language specific processing in the builtin function DECL  */
 418   tree (*builtin_function) (tree decl);
 419
 420   /* Used to set up the tree_contains_structure array for a frontend. */
 421   void (*init_ts) (void);
 422
 423   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 424      to a contained expression or DECL, possibly updating *TC, *TI or
 425      *SE if in the process TREE_CONSTANT, TREE_INVARIANT or
 426      TREE_SIDE_EFFECTS need updating.  */
 427   tree (*expr_to_decl) (tree expr, bool *tc, bool *ti, bool *se);
 428
 429   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 430      and langhooks.c accordingly.  */
 431 };
 432
 433 /* Each front end provides its own.  */
 434 extern const struct lang_hooks lang_hooks;
 435 extern tree add_builtin_function (const char *name, tree type,
 436                                   int function_code, enum built_in_class cl,
 437                                   const char *library_name,
 438                                   tree attrs);
 439
 440 #endif /* GCC_LANG_HOOKS_H */