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   tree (*add_pending_fn_decls) (void *, tree);
  44   int (*auto_var_in_fn_p) (tree, tree);
  45   int (*anon_aggr_type_p) (tree);
  46   bool (*var_mod_type_p) (tree, tree);
  47   int (*start_inlining) (tree);
  48   void (*end_inlining) (tree);
  49   tree (*convert_parm_for_inlining) (tree, tree, tree, int);
  50 };
  51
  52 struct lang_hooks_for_callgraph
  53 {
  54   /* The node passed is a language-specific tree node.  If its contents
  55      are relevant to use of other declarations, mark them.  */
  56   tree (*analyze_expr) (tree *, int *, tree);
  57
  58   /* Produce RTL for function passed as argument.  */
  59   void (*expand_function) (tree);
  60 };
  61
  62 /* Lang hooks for management of language-specific data or status
  63    when entering / leaving functions etc.  */
  64 struct lang_hooks_for_functions
  65 {
  66   /* Called when entering a function.  */
  67   void (*init) (struct function *);
  68
  69   /* Called when leaving a function.  */
  70   void (*final) (struct function *);
  71
  72   /* Called when entering a nested function.  */
  73   void (*enter_nested) (struct function *);
  74
  75   /* Called when leaving a nested function.  */
  76   void (*leave_nested) (struct function *);
  77
  78   /* Determines if it's ok for a function to have no noreturn attribute.  */
  79   bool (*missing_noreturn_ok_p) (tree);
  80 };
  81
  82 /* The following hooks are used by tree-dump.c.  */
  83
  84 struct lang_hooks_for_tree_dump
  85 {
  86   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  87      does not want the usual dumping of the second argument.  */
  88   bool (*dump_tree) (void *, tree);
  89
  90   /* Determine type qualifiers in a language-specific way.  */
  91   int (*type_quals) (tree);
  92 };
  93
  94 /* Hooks related to types.  */
  95
  96 struct lang_hooks_for_types
  97 {
  98   /* Return a new type (with the indicated CODE), doing whatever
  99      language-specific processing is required.  */
 100   tree (*make_type) (enum tree_code);
 101
 102   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
 103      mode.  */
 104   tree (*type_for_mode) (enum machine_mode, int);
 105
 106   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
 107      integer type with at least that precision.  */
 108   tree (*type_for_size) (unsigned, int);
 109
 110   /* Given an integer type T, return a type like T but unsigned.
 111      If T is unsigned, the value is T.  */
 112   tree (*unsigned_type) (tree);
 113
 114   /* Given an integer type T, return a type like T but signed.
 115      If T is signed, the value is T.  */
 116   tree (*signed_type) (tree);
 117
 118   /* Return a type the same as TYPE except unsigned or signed
 119      according to UNSIGNEDP.  */
 120   tree (*signed_or_unsigned_type) (int, 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   /* Do necessary preparations before assemble_variable can proceed.  */
 188   void (*prepare_assemble_variable) (tree);
 189
 190   /* True if this decl may be called via a sibcall.  */
 191   bool (*ok_for_sibcall) (tree);
 192
 193   /* Return the COMDAT group into which this DECL should be placed.
 194      It is known that the DECL belongs in *some* COMDAT group when
 195      this hook is called.  The return value will be used immediately,
 196      but not explicitly deallocated, so implementations should not use
 197      xmalloc to allocate the string returned.  (Typically, the return
 198      value will be the string already stored in an
 199      IDENTIFIER_NODE.)  */
 200   const char * (*comdat_group) (tree);
 201
 202   /* True if OpenMP should privatize what this DECL points to rather
 203      than the DECL itself.  */
 204   bool (*omp_privatize_by_reference) (tree);
 205
 206   /* Return sharing kind if OpenMP sharing attribute of DECL is
 207      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 208   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 209
 210   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 211      disregarded in OpenMP construct, because it is going to be
 212      remapped during OpenMP lowering.  SHARED is true if DECL
 213      is going to be shared, false if it is going to be privatized.  */
 214   bool (*omp_disregard_value_expr) (tree, bool);
 215
 216   /* Return true if DECL that is shared iff SHARED is true should
 217      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 218   bool (*omp_private_debug_clause) (tree, bool);
 219
 220   /* Build and return code for a default constructor for DECL in
 221      response to CLAUSE.  Return NULL if nothing to be done.  */
 222   tree (*omp_clause_default_ctor) (tree clause, tree decl);
 223
 224   /* Build and return code for a copy constructor from SRC to DST.  */
 225   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 226
 227   /* Similarly, except use an assignment operator instead.  */
 228   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 229
 230   /* Build and return code destructing DECL.  Return NULL if nothing
 231      to be done.  */
 232   tree (*omp_clause_dtor) (tree clause, tree decl);
 233 };
 234
 235 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 236
 237 struct lang_hooks
 238 {
 239   /* String identifying the front end.  e.g. "GNU C++".  */
 240   const char *name;
 241
 242   /* sizeof (struct lang_identifier), so make_node () creates
 243      identifier nodes long enough for the language-specific slots.  */
 244   size_t identifier_size;
 245
 246   /* Determines the size of any language-specific tcc_constant or
 247      tcc_exceptional nodes.  Since it is called from make_node, the
 248      only information available is the tree code.  Expected to die
 249      on unrecognized codes.  */
 250   size_t (*tree_size) (enum tree_code);
 251
 252   /* The first callback made to the front end, for simple
 253      initialization needed before any calls to handle_option.  Return
 254      the language mask to filter the switch array with.  */
 255   unsigned int (*init_options) (unsigned int argc, const char **argv);
 256
 257   /* Callback used to perform language-specific initialization for the
 258      global diagnostic context structure.  */
 259   void (*initialize_diagnostics) (struct diagnostic_context *);
 260
 261   /* Handle the switch CODE, which has real type enum opt_code from
 262      options.h.  If the switch takes an argument, it is passed in ARG
 263      which points to permanent storage.  The handler is responsible for
 264      checking whether ARG is NULL, which indicates that no argument
 265      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 266      for the positive and negative forms respectively.
 267
 268      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 269      valid and should not be treated as language-independent too.  */
 270   int (*handle_option) (size_t code, const char *arg, int value);
 271
 272   /* Return false to use the default complaint about a missing
 273      argument, otherwise output a complaint and return true.  */
 274   bool (*missing_argument) (const char *opt, size_t code);
 275
 276   /* Called when all command line options have been parsed to allow
 277      further processing and initialization
 278
 279      Should return true to indicate that a compiler back-end is
 280      not required, such as with the -E option.
 281
 282      If errorcount is nonzero after this call the compiler exits
 283      immediately and the finish hook is not called.  */
 284   bool (*post_options) (const char **);
 285
 286   /* Called after post_options to initialize the front end.  Return
 287      false to indicate that no further compilation be performed, in
 288      which case the finish hook is called immediately.  */
 289   bool (*init) (void);
 290
 291   /* Called at the end of compilation, as a finalizer.  */
 292   void (*finish) (void);
 293
 294   /* Parses the entire file.  The argument is nonzero to cause bison
 295      parsers to dump debugging information during parsing.  */
 296   void (*parse_file) (int);
 297
 298   /* Called immediately after parsing to clear the binding stack.  */
 299   void (*clear_binding_stack) (void);
 300
 301   /* Called to obtain the alias set to be used for an expression or type.
 302      Returns -1 if the language does nothing special for it.  */
 303   HOST_WIDE_INT (*get_alias_set) (tree);
 304
 305   /* Called with an expression that is to be processed as a constant.
 306      Returns either the same expression or a language-independent
 307      constant equivalent to its input.  */
 308   tree (*expand_constant) (tree);
 309
 310   /* Called by expand_expr for language-specific tree codes.
 311      Fourth argument is actually an enum expand_modifier.  */
 312   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 313
 314   /* Called by expand_expr to generate the definition of a decl.  Returns
 315      1 if handled, 0 otherwise.  */
 316   int (*expand_decl) (tree);
 317
 318   /* Hook called by safe_from_p for language-specific tree codes.  It is
 319      up to the language front-end to install a hook if it has any such
 320      codes that safe_from_p needs to know about.  Since same_from_p will
 321      recursively explore the TREE_OPERANDs of an expression, this hook
 322      should not reexamine those pieces.  This routine may recursively
 323      call safe_from_p; it should always pass `0' as the TOP_P
 324      parameter.  */
 325   int (*safe_from_p) (rtx, tree);
 326
 327   /* Function to finish handling an incomplete decl at the end of
 328      compilation.  Default hook is does nothing.  */
 329   void (*finish_incomplete_decl) (tree);
 330
 331   /* Mark EXP saying that we need to be able to take the address of
 332      it; it should not be allocated in a register.  Return true if
 333      successful.  */
 334   bool (*mark_addressable) (tree);
 335
 336   /* Hook called by staticp for language-specific tree codes.  */
 337   tree (*staticp) (tree);
 338
 339   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 340      DECL_NODE with a newly GC-allocated copy.  */
 341   void (*dup_lang_specific_decl) (tree);
 342
 343   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 344      thing that the assembler should talk about, set
 345      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 346      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 347      assembler does not talk about it.  */
 348   void (*set_decl_assembler_name) (tree);
 349
 350   /* Nonzero if operations on types narrower than their mode should
 351      have their results reduced to the precision of the type.  */
 352   bool reduce_bit_field_operations;
 353
 354   /* Nonzero if this front end does not generate a dummy BLOCK between
 355      the outermost scope of the function and the FUNCTION_DECL.  See
 356      is_body_block in stmt.c, and its callers.  */
 357   bool no_body_blocks;
 358
 359   /* The front end can add its own statistics to -fmem-report with
 360      this hook.  It should output to stderr.  */
 361   void (*print_statistics) (void);
 362
 363   /* Called by print_tree when there is a tree of class tcc_exceptional
 364      that it doesn't know how to display.  */
 365   lang_print_tree_hook print_xnode;
 366
 367   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 368      and IDENTIFIER_NODE nodes.  */
 369   lang_print_tree_hook print_decl;
 370   lang_print_tree_hook print_type;
 371   lang_print_tree_hook print_identifier;
 372
 373   /* Computes the name to use to print a declaration.  DECL is the
 374      non-NULL declaration in question.  VERBOSITY determines what
 375      information will be printed: 0: DECL_NAME, demangled as
 376      necessary.  1: and scope information.  2: and any other
 377      information that might be interesting, such as function parameter
 378      types in C++.  */
 379   const char *(*decl_printable_name) (tree decl, int verbosity);
 380
 381   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 382      information will be printed: 0: DECL_NAME, demangled as
 383      necessary.  1: and scope information.  */
 384   const char *(*dwarf_name) (tree, int verbosity);
 385
 386   /* This compares two types for equivalence ("compatible" in C-based languages).
 387      This routine should only return 1 if it is sure.  It should not be used
 388      in contexts where erroneously returning 0 causes problems.  */
 389   int (*types_compatible_p) (tree x, tree y);
 390
 391   /* Given a CALL_EXPR, return a function decl that is its target.  */
 392   tree (*lang_get_callee_fndecl) (tree);
 393
 394   /* Called by report_error_function to print out function name.  */
 395   void (*print_error_function) (struct diagnostic_context *, const char *);
 396
 397   /* Called from expr_size to calculate the size of the value of an
 398      expression in a language-dependent way.  Returns a tree for the size
 399      in bytes.  A frontend can call lhd_expr_size to get the default
 400      semantics in cases that it doesn't want to handle specially.  */
 401   tree (*expr_size) (tree);
 402
 403   /* Convert a character from the host's to the target's character
 404      set.  The character should be in what C calls the "basic source
 405      character set" (roughly, the set of characters defined by plain
 406      old ASCII).  The default is to return the character unchanged,
 407      which is correct in most circumstances.  Note that both argument
 408      and result should be sign-extended under -fsigned-char,
 409      zero-extended under -fno-signed-char.  */
 410   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 411
 412   /* Pointers to machine-independent attribute tables, for front ends
 413      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 414      table of attributes specific to the language, a table of
 415      attributes common to two or more languages (to allow easy
 416      sharing), and a table of attributes for checking formats.  */
 417   const struct attribute_spec *attribute_table;
 418   const struct attribute_spec *common_attribute_table;
 419   const struct attribute_spec *format_attribute_table;
 420
 421   /* Function-related language hooks.  */
 422   struct lang_hooks_for_functions function;
 423
 424   struct lang_hooks_for_tree_inlining tree_inlining;
 425
 426   struct lang_hooks_for_callgraph callgraph;
 427
 428   struct lang_hooks_for_tree_dump tree_dump;
 429
 430   struct lang_hooks_for_decls decls;
 431
 432   struct lang_hooks_for_types types;
 433
 434   /* Perform language-specific gimplification on the argument.  Returns an
 435      enum gimplify_status, though we can't see that type here.  */
 436   int (*gimplify_expr) (tree *, tree *, tree *);
 437
 438   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 439      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 440   tree (*fold_obj_type_ref) (tree, tree);
 441
 442   /* Do language specific processing in the builtin function DECL  */
 443   tree (*builtin_function) (tree decl);
 444
 445   /* Used to set up the tree_contains_structure array for a frontend. */
 446   void (*init_ts) (void);
 447
 448   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 449      to a contained expression or DECL, possibly updating *TC, *TI or
 450      *SE if in the process TREE_CONSTANT, TREE_INVARIANT or
 451      TREE_SIDE_EFFECTS need updating.  */
 452   tree (*expr_to_decl) (tree expr, bool *tc, bool *ti, bool *se);
 453
 454   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 455      and langhooks.c accordingly.  */
 456 };
 457
 458 /* Each front end provides its own.  */
 459 extern const struct lang_hooks lang_hooks;
 460 extern tree add_builtin_function (const char *name, tree type,
 461                                   int function_code, enum built_in_class cl,
 462                                   const char *library_name,
 463                                   tree attrs);
 464
 465 #endif /* GCC_LANG_HOOKS_H */