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 struct array_descr_info;
  32
  33 /* A print hook for print_tree ().  */
  34 typedef void (*lang_print_tree_hook) (FILE *, tree, int indent);
  35
  36 enum classify_record
  37   { RECORD_IS_STRUCT, RECORD_IS_CLASS, RECORD_IS_INTERFACE };
  38
  39 /* The following hooks are documented in langhooks.c.  Must not be
  40    NULL.  */
  41
  42 struct lang_hooks_for_tree_inlining
  43 {
  44   bool (*var_mod_type_p) (tree, tree);
  45 };
  46
  47 struct lang_hooks_for_callgraph
  48 {
  49   /* The node passed is a language-specific tree node.  If its contents
  50      are relevant to use of other declarations, mark them.  */
  51   tree (*analyze_expr) (tree *, int *);
  52
  53   /* Emit thunks associated to function.  */
  54   void (*emit_associated_thunks) (tree);
  55 };
  56
  57 /* The following hooks are used by tree-dump.c.  */
  58
  59 struct lang_hooks_for_tree_dump
  60 {
  61   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  62      does not want the usual dumping of the second argument.  */
  63   bool (*dump_tree) (void *, tree);
  64
  65   /* Determine type qualifiers in a language-specific way.  */
  66   int (*type_quals) (const_tree);
  67 };
  68
  69 /* Hooks related to types.  */
  70
  71 struct lang_hooks_for_types
  72 {
  73   /* Return a new type (with the indicated CODE), doing whatever
  74      language-specific processing is required.  */
  75   tree (*make_type) (enum tree_code);
  76
  77   /* Return what kind of RECORD_TYPE this is, mainly for purposes of
  78      debug information.  If not defined, record types are assumed to
  79      be structures.  */
  80   enum classify_record (*classify_record) (tree);
  81
  82   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  83      mode.  */
  84   tree (*type_for_mode) (enum machine_mode, int);
  85
  86   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
  87      integer type with at least that precision.  */
  88   tree (*type_for_size) (unsigned, int);
  89
  90   /* True if the type is an instantiation of a generic type,
  91      e.g. C++ template implicit specializations.  */
  92   bool (*generic_p) (const_tree);
  93
  94   /* Given a type, apply default promotions to unnamed function
  95      arguments and return the new type.  Return the same type if no
  96      change.  Required by any language that supports variadic
  97      arguments.  The default hook dies.  */
  98   tree (*type_promotes_to) (tree);
  99
 100   /* Register TYPE as a builtin type with the indicated NAME.  The
 101      TYPE is placed in the outermost lexical scope.  The semantics
 102      should be analogous to:
 103
 104        typedef TYPE NAME;
 105
 106      in C.  The default hook ignores the declaration.  */
 107   void (*register_builtin_type) (tree, const char *);
 108
 109   /* This routine is called in tree.c to print an error message for
 110      invalid use of an incomplete type.  VALUE is the expression that
 111      was used (or 0 if that isn't known) and TYPE is the type that was
 112      invalid.  */
 113   void (*incomplete_type_error) (const_tree value, const_tree type);
 114
 115   /* Called from assign_temp to return the maximum size, if there is one,
 116      for a type.  */
 117   tree (*max_size) (const_tree);
 118
 119   /* Register language specific type size variables as potentially OpenMP
 120      firstprivate variables.  */
 121   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 122
 123   /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
 124      Called only after doing all language independent checks.
 125      At present, this function is only called when both TYPE1 and TYPE2 are
 126      FUNCTION_TYPEs.  */
 127   bool (*type_hash_eq) (const_tree, const_tree);
 128
 129   /* Return TRUE if TYPE uses a hidden descriptor and fills in information
 130      for the debugger about the array bounds, strides, etc.  */
 131   bool (*get_array_descr_info) (const_tree, struct array_descr_info *);
 132
 133   /* Nonzero if types that are identical are to be hashed so that only
 134      one copy is kept.  If a language requires unique types for each
 135      user-specified type, such as Ada, this should be set to TRUE.  */
 136   bool hash_types;
 137 };
 138
 139 /* Language hooks related to decls and the symbol table.  */
 140
 141 struct lang_hooks_for_decls
 142 {
 143   /* Returns nonzero if we are in the global binding level.  Ada
 144      returns -1 for an undocumented reason used in stor-layout.c.  */
 145   int (*global_bindings_p) (void);
 146
 147   /* Function to add a decl to the current scope level.  Takes one
 148      argument, a decl to add.  Returns that decl, or, if the same
 149      symbol is already declared, may return a different decl for that
 150      name.  */
 151   tree (*pushdecl) (tree);
 152
 153   /* Returns the chain of decls so far in the current scope level.  */
 154   tree (*getdecls) (void);
 155
 156   /* Returns true when we should warn for an unused global DECL.
 157      We will already have checked that it has static binding.  */
 158   bool (*warn_unused_global) (const_tree);
 159
 160   /* Obtain a list of globals and do final output on them at end
 161      of compilation */
 162   void (*final_write_globals) (void);
 163
 164   /* True if this decl may be called via a sibcall.  */
 165   bool (*ok_for_sibcall) (const_tree);
 166
 167   /* Return the COMDAT group into which this DECL should be placed.
 168      It is known that the DECL belongs in *some* COMDAT group when
 169      this hook is called.  The return value will be used immediately,
 170      but not explicitly deallocated, so implementations should not use
 171      xmalloc to allocate the string returned.  (Typically, the return
 172      value will be the string already stored in an
 173      IDENTIFIER_NODE.)  */
 174   const char * (*comdat_group) (tree);
 175
 176   /* True if OpenMP should privatize what this DECL points to rather
 177      than the DECL itself.  */
 178   bool (*omp_privatize_by_reference) (const_tree);
 179
 180   /* Return sharing kind if OpenMP sharing attribute of DECL is
 181      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 182   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 183
 184   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 185      disregarded in OpenMP construct, because it is going to be
 186      remapped during OpenMP lowering.  SHARED is true if DECL
 187      is going to be shared, false if it is going to be privatized.  */
 188   bool (*omp_disregard_value_expr) (tree, bool);
 189
 190   /* Return true if DECL that is shared iff SHARED is true should
 191      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 192   bool (*omp_private_debug_clause) (tree, bool);
 193
 194   /* Build and return code for a default constructor for DECL in
 195      response to CLAUSE.  Return NULL if nothing to be done.  */
 196   tree (*omp_clause_default_ctor) (tree clause, tree decl);
 197
 198   /* Build and return code for a copy constructor from SRC to DST.  */
 199   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 200
 201   /* Similarly, except use an assignment operator instead.  */
 202   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 203
 204   /* Build and return code destructing DECL.  Return NULL if nothing
 205      to be done.  */
 206   tree (*omp_clause_dtor) (tree clause, tree decl);
 207 };
 208
 209 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 210
 211 struct lang_hooks
 212 {
 213   /* String identifying the front end.  e.g. "GNU C++".  */
 214   const char *name;
 215
 216   /* sizeof (struct lang_identifier), so make_node () creates
 217      identifier nodes long enough for the language-specific slots.  */
 218   size_t identifier_size;
 219
 220   /* Determines the size of any language-specific tcc_constant or
 221      tcc_exceptional nodes.  Since it is called from make_node, the
 222      only information available is the tree code.  Expected to die
 223      on unrecognized codes.  */
 224   size_t (*tree_size) (enum tree_code);
 225
 226   /* The first callback made to the front end, for simple
 227      initialization needed before any calls to handle_option.  Return
 228      the language mask to filter the switch array with.  */
 229   unsigned int (*init_options) (unsigned int argc, const char **argv);
 230
 231   /* Callback used to perform language-specific initialization for the
 232      global diagnostic context structure.  */
 233   void (*initialize_diagnostics) (struct diagnostic_context *);
 234
 235   /* Handle the switch CODE, which has real type enum opt_code from
 236      options.h.  If the switch takes an argument, it is passed in ARG
 237      which points to permanent storage.  The handler is responsible for
 238      checking whether ARG is NULL, which indicates that no argument
 239      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 240      for the positive and negative forms respectively.
 241
 242      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 243      valid and should not be treated as language-independent too.  */
 244   int (*handle_option) (size_t code, const char *arg, int value);
 245
 246   /* Return false to use the default complaint about a missing
 247      argument, otherwise output a complaint and return true.  */
 248   bool (*missing_argument) (const char *opt, size_t code);
 249
 250   /* Called when all command line options have been parsed to allow
 251      further processing and initialization
 252
 253      Should return true to indicate that a compiler back-end is
 254      not required, such as with the -E option.
 255
 256      If errorcount is nonzero after this call the compiler exits
 257      immediately and the finish hook is not called.  */
 258   bool (*post_options) (const char **);
 259
 260   /* Called after post_options to initialize the front end.  Return
 261      false to indicate that no further compilation be performed, in
 262      which case the finish hook is called immediately.  */
 263   bool (*init) (void);
 264
 265   /* Called at the end of compilation, as a finalizer.  */
 266   void (*finish) (void);
 267
 268   /* Parses the entire file.  The argument is nonzero to cause bison
 269      parsers to dump debugging information during parsing.  */
 270   void (*parse_file) (int);
 271
 272   /* Determines if it's ok for a function to have no noreturn attribute.  */
 273   bool (*missing_noreturn_ok_p) (tree);
 274
 275   /* Called to obtain the alias set to be used for an expression or type.
 276      Returns -1 if the language does nothing special for it.  */
 277   alias_set_type (*get_alias_set) (tree);
 278
 279   /* Called by expand_expr for language-specific tree codes.
 280      Fourth argument is actually an enum expand_modifier.  */
 281   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 282
 283   /* Called by expand_expr to generate the definition of a decl.  Returns
 284      1 if handled, 0 otherwise.  */
 285   int (*expand_decl) (tree);
 286
 287   /* Function to finish handling an incomplete decl at the end of
 288      compilation.  Default hook is does nothing.  */
 289   void (*finish_incomplete_decl) (tree);
 290
 291   /* Mark EXP saying that we need to be able to take the address of
 292      it; it should not be allocated in a register.  Return true if
 293      successful.  */
 294   bool (*mark_addressable) (tree);
 295
 296   /* Hook called by staticp for language-specific tree codes.  */
 297   tree (*staticp) (tree);
 298
 299   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 300      DECL_NODE with a newly GC-allocated copy.  */
 301   void (*dup_lang_specific_decl) (tree);
 302
 303   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 304      thing that the assembler should talk about, set
 305      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 306      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 307      assembler does not talk about it.  */
 308   void (*set_decl_assembler_name) (tree);
 309
 310   /* Nonzero if this front end does not generate a dummy BLOCK between
 311      the outermost scope of the function and the FUNCTION_DECL.  See
 312      is_body_block in stmt.c, and its callers.  */
 313   bool no_body_blocks;
 314
 315   /* The front end can add its own statistics to -fmem-report with
 316      this hook.  It should output to stderr.  */
 317   void (*print_statistics) (void);
 318
 319   /* Called by print_tree when there is a tree of class tcc_exceptional
 320      that it doesn't know how to display.  */
 321   lang_print_tree_hook print_xnode;
 322
 323   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 324      and IDENTIFIER_NODE nodes.  */
 325   lang_print_tree_hook print_decl;
 326   lang_print_tree_hook print_type;
 327   lang_print_tree_hook print_identifier;
 328
 329   /* Computes the name to use to print a declaration.  DECL is the
 330      non-NULL declaration in question.  VERBOSITY determines what
 331      information will be printed: 0: DECL_NAME, demangled as
 332      necessary.  1: and scope information.  2: and any other
 333      information that might be interesting, such as function parameter
 334      types in C++.  */
 335   const char *(*decl_printable_name) (tree decl, int verbosity);
 336
 337   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 338      information will be printed: 0: DECL_NAME, demangled as
 339      necessary.  1: and scope information.  */
 340   const char *(*dwarf_name) (tree, int verbosity);
 341
 342   /* This compares two types for equivalence ("compatible" in C-based languages).
 343      This routine should only return 1 if it is sure.  It should not be used
 344      in contexts where erroneously returning 0 causes problems.  */
 345   int (*types_compatible_p) (tree x, tree y);
 346
 347   /* Given a CALL_EXPR, return a function decl that is its target.  */
 348   tree (*lang_get_callee_fndecl) (const_tree);
 349
 350   /* Called by report_error_function to print out function name.  */
 351   void (*print_error_function) (struct diagnostic_context *, const char *,
 352                                 struct diagnostic_info *);
 353
 354   /* Called from expr_size to calculate the size of the value of an
 355      expression in a language-dependent way.  Returns a tree for the size
 356      in bytes.  A frontend can call lhd_expr_size to get the default
 357      semantics in cases that it doesn't want to handle specially.  */
 358   tree (*expr_size) (const_tree);
 359
 360   /* Convert a character from the host's to the target's character
 361      set.  The character should be in what C calls the "basic source
 362      character set" (roughly, the set of characters defined by plain
 363      old ASCII).  The default is to return the character unchanged,
 364      which is correct in most circumstances.  Note that both argument
 365      and result should be sign-extended under -fsigned-char,
 366      zero-extended under -fno-signed-char.  */
 367   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 368
 369   /* Pointers to machine-independent attribute tables, for front ends
 370      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 371      table of attributes specific to the language, a table of
 372      attributes common to two or more languages (to allow easy
 373      sharing), and a table of attributes for checking formats.  */
 374   const struct attribute_spec *attribute_table;
 375   const struct attribute_spec *common_attribute_table;
 376   const struct attribute_spec *format_attribute_table;
 377
 378   struct lang_hooks_for_tree_inlining tree_inlining;
 379
 380   struct lang_hooks_for_callgraph callgraph;
 381
 382   struct lang_hooks_for_tree_dump tree_dump;
 383
 384   struct lang_hooks_for_decls decls;
 385
 386   struct lang_hooks_for_types types;
 387
 388   /* Perform language-specific gimplification on the argument.  Returns an
 389      enum gimplify_status, though we can't see that type here.  */
 390   int (*gimplify_expr) (tree *, tree *, tree *);
 391
 392   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 393      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 394   tree (*fold_obj_type_ref) (tree, tree);
 395
 396   /* Do language specific processing in the builtin function DECL  */
 397   tree (*builtin_function) (tree decl);
 398
 399   /* Used to set up the tree_contains_structure array for a frontend. */
 400   void (*init_ts) (void);
 401
 402   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 403      to a contained expression or DECL, possibly updating *TC or *SE
 404      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 405   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 406
 407   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 408      and langhooks.c accordingly.  */
 409 };
 410
 411 /* Each front end provides its own.  */
 412 extern const struct lang_hooks lang_hooks;
 413 extern tree add_builtin_function (const char *name, tree type,
 414                                   int function_code, enum built_in_class cl,
 415                                   const char *library_name,
 416                                   tree attrs);
 417
 418 #endif /* GCC_LANG_HOOKS_H */