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   /* Produce RTL for function passed as argument.  */
  48   void (*expand_function) (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   /* Nonzero if types that are identical are to be hashed so that only
 133      one copy is kept.  If a language requires unique types for each
 134      user-specified type, such as Ada, this should be set to TRUE.  */
 135   bool hash_types;
 136 };
 137
 138 /* Language hooks related to decls and the symbol table.  */
 139
 140 struct lang_hooks_for_decls
 141 {
 142   /* Returns nonzero if we are in the global binding level.  Ada
 143      returns -1 for an undocumented reason used in stor-layout.c.  */
 144   int (*global_bindings_p) (void);
 145
 146   /* Insert BLOCK at the end of the list of subblocks of the
 147      current binding level.  This is used when a BIND_EXPR is expanded,
 148      to handle the BLOCK node inside the BIND_EXPR.  */
 149   void (*insert_block) (tree);
 150
 151   /* Function to add a decl to the current scope level.  Takes one
 152      argument, a decl to add.  Returns that decl, or, if the same
 153      symbol is already declared, may return a different decl for that
 154      name.  */
 155   tree (*pushdecl) (tree);
 156
 157   /* Returns the chain of decls so far in the current scope level.  */
 158   tree (*getdecls) (void);
 159
 160   /* Returns true when we should warn for an unused global DECL.
 161      We will already have checked that it has static binding.  */
 162   bool (*warn_unused_global) (const_tree);
 163
 164   /* Obtain a list of globals and do final output on them at end
 165      of compilation */
 166   void (*final_write_globals) (void);
 167
 168   /* True if this decl may be called via a sibcall.  */
 169   bool (*ok_for_sibcall) (const_tree);
 170
 171   /* Return the COMDAT group into which this DECL should be placed.
 172      It is known that the DECL belongs in *some* COMDAT group when
 173      this hook is called.  The return value will be used immediately,
 174      but not explicitly deallocated, so implementations should not use
 175      xmalloc to allocate the string returned.  (Typically, the return
 176      value will be the string already stored in an
 177      IDENTIFIER_NODE.)  */
 178   const char * (*comdat_group) (tree);
 179
 180   /* True if OpenMP should privatize what this DECL points to rather
 181      than the DECL itself.  */
 182   bool (*omp_privatize_by_reference) (const_tree);
 183
 184   /* Return sharing kind if OpenMP sharing attribute of DECL is
 185      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 186   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 187
 188   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 189      disregarded in OpenMP construct, because it is going to be
 190      remapped during OpenMP lowering.  SHARED is true if DECL
 191      is going to be shared, false if it is going to be privatized.  */
 192   bool (*omp_disregard_value_expr) (tree, bool);
 193
 194   /* Return true if DECL that is shared iff SHARED is true should
 195      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 196   bool (*omp_private_debug_clause) (tree, bool);
 197
 198   /* Build and return code for a default constructor for DECL in
 199      response to CLAUSE.  Return NULL if nothing to be done.  */
 200   tree (*omp_clause_default_ctor) (tree clause, tree decl);
 201
 202   /* Build and return code for a copy constructor from SRC to DST.  */
 203   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 204
 205   /* Similarly, except use an assignment operator instead.  */
 206   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 207
 208   /* Build and return code destructing DECL.  Return NULL if nothing
 209      to be done.  */
 210   tree (*omp_clause_dtor) (tree clause, tree decl);
 211 };
 212
 213 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 214
 215 struct lang_hooks
 216 {
 217   /* String identifying the front end.  e.g. "GNU C++".  */
 218   const char *name;
 219
 220   /* sizeof (struct lang_identifier), so make_node () creates
 221      identifier nodes long enough for the language-specific slots.  */
 222   size_t identifier_size;
 223
 224   /* Determines the size of any language-specific tcc_constant or
 225      tcc_exceptional nodes.  Since it is called from make_node, the
 226      only information available is the tree code.  Expected to die
 227      on unrecognized codes.  */
 228   size_t (*tree_size) (enum tree_code);
 229
 230   /* The first callback made to the front end, for simple
 231      initialization needed before any calls to handle_option.  Return
 232      the language mask to filter the switch array with.  */
 233   unsigned int (*init_options) (unsigned int argc, const char **argv);
 234
 235   /* Callback used to perform language-specific initialization for the
 236      global diagnostic context structure.  */
 237   void (*initialize_diagnostics) (struct diagnostic_context *);
 238
 239   /* Handle the switch CODE, which has real type enum opt_code from
 240      options.h.  If the switch takes an argument, it is passed in ARG
 241      which points to permanent storage.  The handler is responsible for
 242      checking whether ARG is NULL, which indicates that no argument
 243      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 244      for the positive and negative forms respectively.
 245
 246      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 247      valid and should not be treated as language-independent too.  */
 248   int (*handle_option) (size_t code, const char *arg, int value);
 249
 250   /* Return false to use the default complaint about a missing
 251      argument, otherwise output a complaint and return true.  */
 252   bool (*missing_argument) (const char *opt, size_t code);
 253
 254   /* Called when all command line options have been parsed to allow
 255      further processing and initialization
 256
 257      Should return true to indicate that a compiler back-end is
 258      not required, such as with the -E option.
 259
 260      If errorcount is nonzero after this call the compiler exits
 261      immediately and the finish hook is not called.  */
 262   bool (*post_options) (const char **);
 263
 264   /* Called after post_options to initialize the front end.  Return
 265      false to indicate that no further compilation be performed, in
 266      which case the finish hook is called immediately.  */
 267   bool (*init) (void);
 268
 269   /* Called at the end of compilation, as a finalizer.  */
 270   void (*finish) (void);
 271
 272   /* Parses the entire file.  The argument is nonzero to cause bison
 273      parsers to dump debugging information during parsing.  */
 274   void (*parse_file) (int);
 275
 276   /* Called immediately after parsing to clear the binding stack.  */
 277   void (*clear_binding_stack) (void);
 278
 279   /* Called to obtain the alias set to be used for an expression or type.
 280      Returns -1 if the language does nothing special for it.  */
 281   alias_set_type (*get_alias_set) (tree);
 282
 283   /* Called with an expression that is to be processed as a constant.
 284      Returns either the same expression or a language-independent
 285      constant equivalent to its input.  */
 286   tree (*expand_constant) (tree);
 287
 288   /* Called by expand_expr for language-specific tree codes.
 289      Fourth argument is actually an enum expand_modifier.  */
 290   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 291
 292   /* Called by expand_expr to generate the definition of a decl.  Returns
 293      1 if handled, 0 otherwise.  */
 294   int (*expand_decl) (tree);
 295
 296   /* Function to finish handling an incomplete decl at the end of
 297      compilation.  Default hook is does nothing.  */
 298   void (*finish_incomplete_decl) (tree);
 299
 300   /* Mark EXP saying that we need to be able to take the address of
 301      it; it should not be allocated in a register.  Return true if
 302      successful.  */
 303   bool (*mark_addressable) (tree);
 304
 305   /* Hook called by staticp for language-specific tree codes.  */
 306   tree (*staticp) (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   /* Nonzero if operations on types narrower than their mode should
 320      have their results reduced to the precision of the type.  */
 321   bool reduce_bit_field_operations;
 322
 323   /* Nonzero if this front end does not generate a dummy BLOCK between
 324      the outermost scope of the function and the FUNCTION_DECL.  See
 325      is_body_block in stmt.c, and its callers.  */
 326   bool no_body_blocks;
 327
 328   /* The front end can add its own statistics to -fmem-report with
 329      this hook.  It should output to stderr.  */
 330   void (*print_statistics) (void);
 331
 332   /* Called by print_tree when there is a tree of class tcc_exceptional
 333      that it doesn't know how to display.  */
 334   lang_print_tree_hook print_xnode;
 335
 336   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 337      and IDENTIFIER_NODE nodes.  */
 338   lang_print_tree_hook print_decl;
 339   lang_print_tree_hook print_type;
 340   lang_print_tree_hook print_identifier;
 341
 342   /* Computes the name to use to print a declaration.  DECL is the
 343      non-NULL declaration in question.  VERBOSITY determines what
 344      information will be printed: 0: DECL_NAME, demangled as
 345      necessary.  1: and scope information.  2: and any other
 346      information that might be interesting, such as function parameter
 347      types in C++.  */
 348   const char *(*decl_printable_name) (tree decl, int verbosity);
 349
 350   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 351      information will be printed: 0: DECL_NAME, demangled as
 352      necessary.  1: and scope information.  */
 353   const char *(*dwarf_name) (tree, int verbosity);
 354
 355   /* This compares two types for equivalence ("compatible" in C-based languages).
 356      This routine should only return 1 if it is sure.  It should not be used
 357      in contexts where erroneously returning 0 causes problems.  */
 358   int (*types_compatible_p) (tree x, tree y);
 359
 360   /* Given a CALL_EXPR, return a function decl that is its target.  */
 361   tree (*lang_get_callee_fndecl) (const_tree);
 362
 363   /* Called by report_error_function to print out function name.  */
 364   void (*print_error_function) (struct diagnostic_context *, const char *);
 365
 366   /* Called from expr_size to calculate the size of the value of an
 367      expression in a language-dependent way.  Returns a tree for the size
 368      in bytes.  A frontend can call lhd_expr_size to get the default
 369      semantics in cases that it doesn't want to handle specially.  */
 370   tree (*expr_size) (const_tree);
 371
 372   /* Convert a character from the host's to the target's character
 373      set.  The character should be in what C calls the "basic source
 374      character set" (roughly, the set of characters defined by plain
 375      old ASCII).  The default is to return the character unchanged,
 376      which is correct in most circumstances.  Note that both argument
 377      and result should be sign-extended under -fsigned-char,
 378      zero-extended under -fno-signed-char.  */
 379   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 380
 381   /* Pointers to machine-independent attribute tables, for front ends
 382      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 383      table of attributes specific to the language, a table of
 384      attributes common to two or more languages (to allow easy
 385      sharing), and a table of attributes for checking formats.  */
 386   const struct attribute_spec *attribute_table;
 387   const struct attribute_spec *common_attribute_table;
 388   const struct attribute_spec *format_attribute_table;
 389
 390   /* Function-related language hooks.  */
 391   struct lang_hooks_for_functions function;
 392
 393   struct lang_hooks_for_tree_inlining tree_inlining;
 394
 395   struct lang_hooks_for_callgraph callgraph;
 396
 397   struct lang_hooks_for_tree_dump tree_dump;
 398
 399   struct lang_hooks_for_decls decls;
 400
 401   struct lang_hooks_for_types types;
 402
 403   /* Perform language-specific gimplification on the argument.  Returns an
 404      enum gimplify_status, though we can't see that type here.  */
 405   int (*gimplify_expr) (tree *, tree *, tree *);
 406
 407   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 408      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 409   tree (*fold_obj_type_ref) (tree, tree);
 410
 411   /* Do language specific processing in the builtin function DECL  */
 412   tree (*builtin_function) (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, *TI or
 419      *SE if in the process TREE_CONSTANT, TREE_INVARIANT or
 420      TREE_SIDE_EFFECTS need updating.  */
 421   tree (*expr_to_decl) (tree expr, bool *tc, bool *ti, bool *se);
 422
 423   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 424      and langhooks.c accordingly.  */
 425 };
 426
 427 /* Each front end provides its own.  */
 428 extern const struct lang_hooks lang_hooks;
 429 extern tree add_builtin_function (const char *name, tree type,
 430                                   int function_code, enum built_in_class cl,
 431                                   const char *library_name,
 432                                   tree attrs);
 433
 434 #endif /* GCC_LANG_HOOKS_H */