gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GCC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  19 Boston, MA 02110-1301, USA.  */
  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   tree (*walk_subtrees) (tree *, int *,
  39                          tree (*) (tree *, int *, void *),
  40                          void *, struct pointer_set_t*);
  41   int (*cannot_inline_tree_fn) (tree *);
  42   int (*disregard_inline_limits) (tree);
  43   int (*auto_var_in_fn_p) (tree, tree);
  44   bool (*var_mod_type_p) (tree, tree);
  45   tree (*convert_parm_for_inlining) (tree, tree, tree, int);
  46 };
  47
  48 struct lang_hooks_for_callgraph
  49 {
  50   /* The node passed is a language-specific tree node.  If its contents
  51      are relevant to use of other declarations, mark them.  */
  52   tree (*analyze_expr) (tree *, int *, tree);
  53
  54   /* Produce RTL for function passed as argument.  */
  55   void (*expand_function) (tree);
  56 };
  57
  58 /* Lang hooks for management of language-specific data or status
  59    when entering / leaving functions etc.  */
  60 struct lang_hooks_for_functions
  61 {
  62   /* Called when entering a function.  */
  63   void (*init) (struct function *);
  64
  65   /* Called when leaving a function.  */
  66   void (*final) (struct function *);
  67
  68   /* Called when entering a nested function.  */
  69   void (*enter_nested) (struct function *);
  70
  71   /* Called when leaving a nested function.  */
  72   void (*leave_nested) (struct function *);
  73
  74   /* Determines if it's ok for a function to have no noreturn attribute.  */
  75   bool (*missing_noreturn_ok_p) (tree);
  76 };
  77
  78 /* The following hooks are used by tree-dump.c.  */
  79
  80 struct lang_hooks_for_tree_dump
  81 {
  82   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  83      does not want the usual dumping of the second argument.  */
  84   bool (*dump_tree) (void *, tree);
  85
  86   /* Determine type qualifiers in a language-specific way.  */
  87   int (*type_quals) (tree);
  88 };
  89
  90 /* Hooks related to types.  */
  91
  92 struct lang_hooks_for_types
  93 {
  94   /* Return a new type (with the indicated CODE), doing whatever
  95      language-specific processing is required.  */
  96   tree (*make_type) (enum tree_code);
  97
  98   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  99      mode.  */
 100   tree (*type_for_mode) (enum machine_mode, int);
 101
 102   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
 103      integer type with at least that precision.  */
 104   tree (*type_for_size) (unsigned, int);
 105
 106   /* Given an integer type T, return a type like T but unsigned.
 107      If T is unsigned, the value is T.  */
 108   tree (*unsigned_type) (tree);
 109
 110   /* Given an integer type T, return a type like T but signed.
 111      If T is signed, the value is T.  */
 112   tree (*signed_type) (tree);
 113
 114   /* Return a type the same as TYPE except unsigned or signed
 115      according to UNSIGNEDP.  */
 116   tree (*signed_or_unsigned_type) (int, tree);
 117
 118   /* True if the type is an instantiation of a generic type,
 119      e.g. C++ template implicit specializations.  */
 120   bool (*generic_p) (tree);
 121
 122   /* Given a type, apply default promotions to unnamed function
 123      arguments and return the new type.  Return the same type if no
 124      change.  Required by any language that supports variadic
 125      arguments.  The default hook dies.  */
 126   tree (*type_promotes_to) (tree);
 127
 128   /* Register TYPE as a builtin type with the indicated NAME.  The
 129      TYPE is placed in the outermost lexical scope.  The semantics
 130      should be analogous to:
 131
 132        typedef TYPE NAME;
 133
 134      in C.  The default hook ignores the declaration.  */
 135   void (*register_builtin_type) (tree, const char *);
 136
 137   /* This routine is called in tree.c to print an error message for
 138      invalid use of an incomplete type.  VALUE is the expression that
 139      was used (or 0 if that isn't known) and TYPE is the type that was
 140      invalid.  */
 141   void (*incomplete_type_error) (tree value, tree type);
 142
 143   /* Called from assign_temp to return the maximum size, if there is one,
 144      for a type.  */
 145   tree (*max_size) (tree);
 146
 147   /* Register language specific type size variables as potentially OpenMP
 148      firstprivate variables.  */
 149   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 150
 151   /* Nonzero if types that are identical are to be hashed so that only
 152      one copy is kept.  If a language requires unique types for each
 153      user-specified type, such as Ada, this should be set to TRUE.  */
 154   bool hash_types;
 155 };
 156
 157 /* Language hooks related to decls and the symbol table.  */
 158
 159 struct lang_hooks_for_decls
 160 {
 161   /* Returns nonzero if we are in the global binding level.  Ada
 162      returns -1 for an undocumented reason used in stor-layout.c.  */
 163   int (*global_bindings_p) (void);
 164
 165   /* Insert BLOCK at the end of the list of subblocks of the
 166      current binding level.  This is used when a BIND_EXPR is expanded,
 167      to handle the BLOCK node inside the BIND_EXPR.  */
 168   void (*insert_block) (tree);
 169
 170   /* Function to add a decl to the current scope level.  Takes one
 171      argument, a decl to add.  Returns that decl, or, if the same
 172      symbol is already declared, may return a different decl for that
 173      name.  */
 174   tree (*pushdecl) (tree);
 175
 176   /* Returns the chain of decls so far in the current scope level.  */
 177   tree (*getdecls) (void);
 178
 179   /* Returns true when we should warn for an unused global DECL.
 180      We will already have checked that it has static binding.  */
 181   bool (*warn_unused_global) (tree);
 182
 183   /* Obtain a list of globals and do final output on them at end
 184      of compilation */
 185   void (*final_write_globals) (void);
 186
 187   /* True if this decl may be called via a sibcall.  */
 188   bool (*ok_for_sibcall) (tree);
 189
 190   /* Return the COMDAT group into which this DECL should be placed.
 191      It is known that the DECL belongs in *some* COMDAT group when
 192      this hook is called.  The return value will be used immediately,
 193      but not explicitly deallocated, so implementations should not use
 194      xmalloc to allocate the string returned.  (Typically, the return
 195      value will be the string already stored in an
 196      IDENTIFIER_NODE.)  */
 197   const char * (*comdat_group) (tree);
 198
 199   /* True if OpenMP should privatize what this DECL points to rather
 200      than the DECL itself.  */
 201   bool (*omp_privatize_by_reference) (tree);
 202
 203   /* Return sharing kind if OpenMP sharing attribute of DECL is
 204      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 205   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 206
 207   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 208      disregarded in OpenMP construct, because it is going to be
 209      remapped during OpenMP lowering.  SHARED is true if DECL
 210      is going to be shared, false if it is going to be privatized.  */
 211   bool (*omp_disregard_value_expr) (tree, bool);
 212
 213   /* Return true if DECL that is shared iff SHARED is true should
 214      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 215   bool (*omp_private_debug_clause) (tree, bool);
 216
 217   /* Build and return code for a default constructor for DECL in
 218      response to CLAUSE.  Return NULL if nothing to be done.  */
 219   tree (*omp_clause_default_ctor) (tree clause, tree decl);
 220
 221   /* Build and return code for a copy constructor from SRC to DST.  */
 222   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 223
 224   /* Similarly, except use an assignment operator instead.  */
 225   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 226
 227   /* Build and return code destructing DECL.  Return NULL if nothing
 228      to be done.  */
 229   tree (*omp_clause_dtor) (tree clause, tree decl);
 230 };
 231
 232 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 233
 234 struct lang_hooks
 235 {
 236   /* String identifying the front end.  e.g. "GNU C++".  */
 237   const char *name;
 238
 239   /* sizeof (struct lang_identifier), so make_node () creates
 240      identifier nodes long enough for the language-specific slots.  */
 241   size_t identifier_size;
 242
 243   /* Determines the size of any language-specific tcc_constant or
 244      tcc_exceptional nodes.  Since it is called from make_node, the
 245      only information available is the tree code.  Expected to die
 246      on unrecognized codes.  */
 247   size_t (*tree_size) (enum tree_code);
 248
 249   /* The first callback made to the front end, for simple
 250      initialization needed before any calls to handle_option.  Return
 251      the language mask to filter the switch array with.  */
 252   unsigned int (*init_options) (unsigned int argc, const char **argv);
 253
 254   /* Callback used to perform language-specific initialization for the
 255      global diagnostic context structure.  */
 256   void (*initialize_diagnostics) (struct diagnostic_context *);
 257
 258   /* Handle the switch CODE, which has real type enum opt_code from
 259      options.h.  If the switch takes an argument, it is passed in ARG
 260      which points to permanent storage.  The handler is responsible for
 261      checking whether ARG is NULL, which indicates that no argument
 262      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 263      for the positive and negative forms respectively.
 264
 265      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 266      valid and should not be treated as language-independent too.  */
 267   int (*handle_option) (size_t code, const char *arg, int value);
 268
 269   /* Return false to use the default complaint about a missing
 270      argument, otherwise output a complaint and return true.  */
 271   bool (*missing_argument) (const char *opt, size_t code);
 272
 273   /* Called when all command line options have been parsed to allow
 274      further processing and initialization
 275
 276      Should return true to indicate that a compiler back-end is
 277      not required, such as with the -E option.
 278
 279      If errorcount is nonzero after this call the compiler exits
 280      immediately and the finish hook is not called.  */
 281   bool (*post_options) (const char **);
 282
 283   /* Called after post_options to initialize the front end.  Return
 284      false to indicate that no further compilation be performed, in
 285      which case the finish hook is called immediately.  */
 286   bool (*init) (void);
 287
 288   /* Called at the end of compilation, as a finalizer.  */
 289   void (*finish) (void);
 290
 291   /* Parses the entire file.  The argument is nonzero to cause bison
 292      parsers to dump debugging information during parsing.  */
 293   void (*parse_file) (int);
 294
 295   /* Called immediately after parsing to clear the binding stack.  */
 296   void (*clear_binding_stack) (void);
 297
 298   /* Called to obtain the alias set to be used for an expression or type.
 299      Returns -1 if the language does nothing special for it.  */
 300   HOST_WIDE_INT (*get_alias_set) (tree);
 301
 302   /* Called with an expression that is to be processed as a constant.
 303      Returns either the same expression or a language-independent
 304      constant equivalent to its input.  */
 305   tree (*expand_constant) (tree);
 306
 307   /* Called by expand_expr for language-specific tree codes.
 308      Fourth argument is actually an enum expand_modifier.  */
 309   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 310
 311   /* Called by expand_expr to generate the definition of a decl.  Returns
 312      1 if handled, 0 otherwise.  */
 313   int (*expand_decl) (tree);
 314
 315   /* Function to finish handling an incomplete decl at the end of
 316      compilation.  Default hook is does nothing.  */
 317   void (*finish_incomplete_decl) (tree);
 318
 319   /* Mark EXP saying that we need to be able to take the address of
 320      it; it should not be allocated in a register.  Return true if
 321      successful.  */
 322   bool (*mark_addressable) (tree);
 323
 324   /* Hook called by staticp for language-specific tree codes.  */
 325   tree (*staticp) (tree);
 326
 327   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 328      DECL_NODE with a newly GC-allocated copy.  */
 329   void (*dup_lang_specific_decl) (tree);
 330
 331   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 332      thing that the assembler should talk about, set
 333      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 334      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 335      assembler does not talk about it.  */
 336   void (*set_decl_assembler_name) (tree);
 337
 338   /* Nonzero if operations on types narrower than their mode should
 339      have their results reduced to the precision of the type.  */
 340   bool reduce_bit_field_operations;
 341
 342   /* Nonzero if this front end does not generate a dummy BLOCK between
 343      the outermost scope of the function and the FUNCTION_DECL.  See
 344      is_body_block in stmt.c, and its callers.  */
 345   bool no_body_blocks;
 346
 347   /* The front end can add its own statistics to -fmem-report with
 348      this hook.  It should output to stderr.  */
 349   void (*print_statistics) (void);
 350
 351   /* Called by print_tree when there is a tree of class tcc_exceptional
 352      that it doesn't know how to display.  */
 353   lang_print_tree_hook print_xnode;
 354
 355   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 356      and IDENTIFIER_NODE nodes.  */
 357   lang_print_tree_hook print_decl;
 358   lang_print_tree_hook print_type;
 359   lang_print_tree_hook print_identifier;
 360
 361   /* Computes the name to use to print a declaration.  DECL is the
 362      non-NULL declaration in question.  VERBOSITY determines what
 363      information will be printed: 0: DECL_NAME, demangled as
 364      necessary.  1: and scope information.  2: and any other
 365      information that might be interesting, such as function parameter
 366      types in C++.  */
 367   const char *(*decl_printable_name) (tree decl, int verbosity);
 368
 369   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 370      information will be printed: 0: DECL_NAME, demangled as
 371      necessary.  1: and scope information.  */
 372   const char *(*dwarf_name) (tree, int verbosity);
 373
 374   /* This compares two types for equivalence ("compatible" in C-based languages).
 375      This routine should only return 1 if it is sure.  It should not be used
 376      in contexts where erroneously returning 0 causes problems.  */
 377   int (*types_compatible_p) (tree x, tree y);
 378
 379   /* Given a CALL_EXPR, return a function decl that is its target.  */
 380   tree (*lang_get_callee_fndecl) (tree);
 381
 382   /* Called by report_error_function to print out function name.  */
 383   void (*print_error_function) (struct diagnostic_context *, const char *);
 384
 385   /* Called from expr_size to calculate the size of the value of an
 386      expression in a language-dependent way.  Returns a tree for the size
 387      in bytes.  A frontend can call lhd_expr_size to get the default
 388      semantics in cases that it doesn't want to handle specially.  */
 389   tree (*expr_size) (tree);
 390
 391   /* Convert a character from the host's to the target's character
 392      set.  The character should be in what C calls the "basic source
 393      character set" (roughly, the set of characters defined by plain
 394      old ASCII).  The default is to return the character unchanged,
 395      which is correct in most circumstances.  Note that both argument
 396      and result should be sign-extended under -fsigned-char,
 397      zero-extended under -fno-signed-char.  */
 398   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 399
 400   /* Pointers to machine-independent attribute tables, for front ends
 401      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 402      table of attributes specific to the language, a table of
 403      attributes common to two or more languages (to allow easy
 404      sharing), and a table of attributes for checking formats.  */
 405   const struct attribute_spec *attribute_table;
 406   const struct attribute_spec *common_attribute_table;
 407   const struct attribute_spec *format_attribute_table;
 408
 409   /* Function-related language hooks.  */
 410   struct lang_hooks_for_functions function;
 411
 412   struct lang_hooks_for_tree_inlining tree_inlining;
 413
 414   struct lang_hooks_for_callgraph callgraph;
 415
 416   struct lang_hooks_for_tree_dump tree_dump;
 417
 418   struct lang_hooks_for_decls decls;
 419
 420   struct lang_hooks_for_types types;
 421
 422   /* Perform language-specific gimplification on the argument.  Returns an
 423      enum gimplify_status, though we can't see that type here.  */
 424   int (*gimplify_expr) (tree *, tree *, tree *);
 425
 426   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 427      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 428   tree (*fold_obj_type_ref) (tree, tree);
 429
 430   /* Do language specific processing in the builtin function DECL  */
 431   tree (*builtin_function) (tree decl);
 432
 433   /* Used to set up the tree_contains_structure array for a frontend. */
 434   void (*init_ts) (void);
 435
 436   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 437      to a contained expression or DECL, possibly updating *TC, *TI or
 438      *SE if in the process TREE_CONSTANT, TREE_INVARIANT or
 439      TREE_SIDE_EFFECTS need updating.  */
 440   tree (*expr_to_decl) (tree expr, bool *tc, bool *ti, bool *se);
 441
 442   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 443      and langhooks.c accordingly.  */
 444 };
 445
 446 /* Each front end provides its own.  */
 447 extern const struct lang_hooks lang_hooks;
 448 extern tree add_builtin_function (const char *name, tree type,
 449                                   int function_code, enum built_in_class cl,
 450                                   const char *library_name,
 451                                   tree attrs);
 452 extern tree lhd_signed_or_unsigned_type (int unsignedp, tree type);
 453
 454 #endif /* GCC_LANG_HOOKS_H */