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 /* Lang hooks for management of language-specific data or status
  58    when entering / leaving functions etc.  */
  59 struct lang_hooks_for_functions
  60 {
  61   /* Called when entering a function.  */
  62   void (*init) (struct function *);
  63
  64   /* Called when leaving a function.  */
  65   void (*final) (struct function *);
  66
  67   /* Called when entering a nested function.  */
  68   void (*enter_nested) (struct function *);
  69
  70   /* Called when leaving a nested function.  */
  71   void (*leave_nested) (struct function *);
  72
  73   /* Determines if it's ok for a function to have no noreturn attribute.  */
  74   bool (*missing_noreturn_ok_p) (tree);
  75 };
  76
  77 /* The following hooks are used by tree-dump.c.  */
  78
  79 struct lang_hooks_for_tree_dump
  80 {
  81   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  82      does not want the usual dumping of the second argument.  */
  83   bool (*dump_tree) (void *, tree);
  84
  85   /* Determine type qualifiers in a language-specific way.  */
  86   int (*type_quals) (const_tree);
  87 };
  88
  89 /* Hooks related to types.  */
  90
  91 struct lang_hooks_for_types
  92 {
  93   /* Return a new type (with the indicated CODE), doing whatever
  94      language-specific processing is required.  */
  95   tree (*make_type) (enum tree_code);
  96
  97   /* Return what kind of RECORD_TYPE this is, mainly for purposes of
  98      debug information.  If not defined, record types are assumed to
  99      be structures.  */
 100   enum classify_record (*classify_record) (tree);
 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   /* True if the type is an instantiation of a generic type,
 111      e.g. C++ template implicit specializations.  */
 112   bool (*generic_p) (const_tree);
 113
 114   /* Given a type, apply default promotions to unnamed function
 115      arguments and return the new type.  Return the same type if no
 116      change.  Required by any language that supports variadic
 117      arguments.  The default hook dies.  */
 118   tree (*type_promotes_to) (tree);
 119
 120   /* Register TYPE as a builtin type with the indicated NAME.  The
 121      TYPE is placed in the outermost lexical scope.  The semantics
 122      should be analogous to:
 123
 124        typedef TYPE NAME;
 125
 126      in C.  The default hook ignores the declaration.  */
 127   void (*register_builtin_type) (tree, const char *);
 128
 129   /* This routine is called in tree.c to print an error message for
 130      invalid use of an incomplete type.  VALUE is the expression that
 131      was used (or 0 if that isn't known) and TYPE is the type that was
 132      invalid.  */
 133   void (*incomplete_type_error) (const_tree value, const_tree type);
 134
 135   /* Called from assign_temp to return the maximum size, if there is one,
 136      for a type.  */
 137   tree (*max_size) (const_tree);
 138
 139   /* Register language specific type size variables as potentially OpenMP
 140      firstprivate variables.  */
 141   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 142
 143   /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
 144      Called only after doing all language independent checks.
 145      At present, this function is only called when both TYPE1 and TYPE2 are
 146      FUNCTION_TYPEs.  */
 147   bool (*type_hash_eq) (const_tree, const_tree);
 148
 149   /* Return TRUE if TYPE uses a hidden descriptor and fills in information
 150      for the debugger about the array bounds, strides, etc.  */
 151   bool (*get_array_descr_info) (const_tree, struct array_descr_info *);
 152
 153   /* Nonzero if types that are identical are to be hashed so that only
 154      one copy is kept.  If a language requires unique types for each
 155      user-specified type, such as Ada, this should be set to TRUE.  */
 156   bool hash_types;
 157 };
 158
 159 /* Language hooks related to decls and the symbol table.  */
 160
 161 struct lang_hooks_for_decls
 162 {
 163   /* Returns nonzero if we are in the global binding level.  Ada
 164      returns -1 for an undocumented reason used in stor-layout.c.  */
 165   int (*global_bindings_p) (void);
 166
 167   /* Insert BLOCK at the end of the list of subblocks of the
 168      current binding level.  This is used when a BIND_EXPR is expanded,
 169      to handle the BLOCK node inside the BIND_EXPR.  */
 170   void (*insert_block) (tree);
 171
 172   /* Function to add a decl to the current scope level.  Takes one
 173      argument, a decl to add.  Returns that decl, or, if the same
 174      symbol is already declared, may return a different decl for that
 175      name.  */
 176   tree (*pushdecl) (tree);
 177
 178   /* Returns the chain of decls so far in the current scope level.  */
 179   tree (*getdecls) (void);
 180
 181   /* Returns true when we should warn for an unused global DECL.
 182      We will already have checked that it has static binding.  */
 183   bool (*warn_unused_global) (const_tree);
 184
 185   /* Obtain a list of globals and do final output on them at end
 186      of compilation */
 187   void (*final_write_globals) (void);
 188
 189   /* True if this decl may be called via a sibcall.  */
 190   bool (*ok_for_sibcall) (const_tree);
 191
 192   /* Return the COMDAT group into which this DECL should be placed.
 193      It is known that the DECL belongs in *some* COMDAT group when
 194      this hook is called.  The return value will be used immediately,
 195      but not explicitly deallocated, so implementations should not use
 196      xmalloc to allocate the string returned.  (Typically, the return
 197      value will be the string already stored in an
 198      IDENTIFIER_NODE.)  */
 199   const char * (*comdat_group) (tree);
 200
 201   /* True if OpenMP should privatize what this DECL points to rather
 202      than the DECL itself.  */
 203   bool (*omp_privatize_by_reference) (const_tree);
 204
 205   /* Return sharing kind if OpenMP sharing attribute of DECL is
 206      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 207   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 208
 209   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 210      disregarded in OpenMP construct, because it is going to be
 211      remapped during OpenMP lowering.  SHARED is true if DECL
 212      is going to be shared, false if it is going to be privatized.  */
 213   bool (*omp_disregard_value_expr) (tree, bool);
 214
 215   /* Return true if DECL that is shared iff SHARED is true should
 216      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 217   bool (*omp_private_debug_clause) (tree, bool);
 218
 219   /* Build and return code for a default constructor for DECL in
 220      response to CLAUSE.  Return NULL if nothing to be done.  */
 221   tree (*omp_clause_default_ctor) (tree clause, tree decl);
 222
 223   /* Build and return code for a copy constructor from SRC to DST.  */
 224   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 225
 226   /* Similarly, except use an assignment operator instead.  */
 227   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 228
 229   /* Build and return code destructing DECL.  Return NULL if nothing
 230      to be done.  */
 231   tree (*omp_clause_dtor) (tree clause, tree decl);
 232 };
 233
 234 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 235
 236 struct lang_hooks
 237 {
 238   /* String identifying the front end.  e.g. "GNU C++".  */
 239   const char *name;
 240
 241   /* sizeof (struct lang_identifier), so make_node () creates
 242      identifier nodes long enough for the language-specific slots.  */
 243   size_t identifier_size;
 244
 245   /* Determines the size of any language-specific tcc_constant or
 246      tcc_exceptional nodes.  Since it is called from make_node, the
 247      only information available is the tree code.  Expected to die
 248      on unrecognized codes.  */
 249   size_t (*tree_size) (enum tree_code);
 250
 251   /* The first callback made to the front end, for simple
 252      initialization needed before any calls to handle_option.  Return
 253      the language mask to filter the switch array with.  */
 254   unsigned int (*init_options) (unsigned int argc, const char **argv);
 255
 256   /* Callback used to perform language-specific initialization for the
 257      global diagnostic context structure.  */
 258   void (*initialize_diagnostics) (struct diagnostic_context *);
 259
 260   /* Handle the switch CODE, which has real type enum opt_code from
 261      options.h.  If the switch takes an argument, it is passed in ARG
 262      which points to permanent storage.  The handler is responsible for
 263      checking whether ARG is NULL, which indicates that no argument
 264      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 265      for the positive and negative forms respectively.
 266
 267      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 268      valid and should not be treated as language-independent too.  */
 269   int (*handle_option) (size_t code, const char *arg, int value);
 270
 271   /* Return false to use the default complaint about a missing
 272      argument, otherwise output a complaint and return true.  */
 273   bool (*missing_argument) (const char *opt, size_t code);
 274
 275   /* Called when all command line options have been parsed to allow
 276      further processing and initialization
 277
 278      Should return true to indicate that a compiler back-end is
 279      not required, such as with the -E option.
 280
 281      If errorcount is nonzero after this call the compiler exits
 282      immediately and the finish hook is not called.  */
 283   bool (*post_options) (const char **);
 284
 285   /* Called after post_options to initialize the front end.  Return
 286      false to indicate that no further compilation be performed, in
 287      which case the finish hook is called immediately.  */
 288   bool (*init) (void);
 289
 290   /* Called at the end of compilation, as a finalizer.  */
 291   void (*finish) (void);
 292
 293   /* Parses the entire file.  The argument is nonzero to cause bison
 294      parsers to dump debugging information during parsing.  */
 295   void (*parse_file) (int);
 296
 297   /* Called to obtain the alias set to be used for an expression or type.
 298      Returns -1 if the language does nothing special for it.  */
 299   alias_set_type (*get_alias_set) (tree);
 300
 301   /* Called by expand_expr for language-specific tree codes.
 302      Fourth argument is actually an enum expand_modifier.  */
 303   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 304
 305   /* Called by expand_expr to generate the definition of a decl.  Returns
 306      1 if handled, 0 otherwise.  */
 307   int (*expand_decl) (tree);
 308
 309   /* Function to finish handling an incomplete decl at the end of
 310      compilation.  Default hook is does nothing.  */
 311   void (*finish_incomplete_decl) (tree);
 312
 313   /* Mark EXP saying that we need to be able to take the address of
 314      it; it should not be allocated in a register.  Return true if
 315      successful.  */
 316   bool (*mark_addressable) (tree);
 317
 318   /* Hook called by staticp for language-specific tree codes.  */
 319   tree (*staticp) (tree);
 320
 321   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 322      DECL_NODE with a newly GC-allocated copy.  */
 323   void (*dup_lang_specific_decl) (tree);
 324
 325   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 326      thing that the assembler should talk about, set
 327      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 328      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 329      assembler does not talk about it.  */
 330   void (*set_decl_assembler_name) (tree);
 331
 332   /* Nonzero if operations on types narrower than their mode should
 333      have their results reduced to the precision of the type.  */
 334   bool reduce_bit_field_operations;
 335
 336   /* Nonzero if this front end does not generate a dummy BLOCK between
 337      the outermost scope of the function and the FUNCTION_DECL.  See
 338      is_body_block in stmt.c, and its callers.  */
 339   bool no_body_blocks;
 340
 341   /* The front end can add its own statistics to -fmem-report with
 342      this hook.  It should output to stderr.  */
 343   void (*print_statistics) (void);
 344
 345   /* Called by print_tree when there is a tree of class tcc_exceptional
 346      that it doesn't know how to display.  */
 347   lang_print_tree_hook print_xnode;
 348
 349   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 350      and IDENTIFIER_NODE nodes.  */
 351   lang_print_tree_hook print_decl;
 352   lang_print_tree_hook print_type;
 353   lang_print_tree_hook print_identifier;
 354
 355   /* Computes the name to use to print a declaration.  DECL is the
 356      non-NULL declaration in question.  VERBOSITY determines what
 357      information will be printed: 0: DECL_NAME, demangled as
 358      necessary.  1: and scope information.  2: and any other
 359      information that might be interesting, such as function parameter
 360      types in C++.  */
 361   const char *(*decl_printable_name) (tree decl, int verbosity);
 362
 363   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 364      information will be printed: 0: DECL_NAME, demangled as
 365      necessary.  1: and scope information.  */
 366   const char *(*dwarf_name) (tree, int verbosity);
 367
 368   /* This compares two types for equivalence ("compatible" in C-based languages).
 369      This routine should only return 1 if it is sure.  It should not be used
 370      in contexts where erroneously returning 0 causes problems.  */
 371   int (*types_compatible_p) (tree x, tree y);
 372
 373   /* Given a CALL_EXPR, return a function decl that is its target.  */
 374   tree (*lang_get_callee_fndecl) (const_tree);
 375
 376   /* Called by report_error_function to print out function name.  */
 377   void (*print_error_function) (struct diagnostic_context *, const char *,
 378                                 struct diagnostic_info *);
 379
 380   /* Called from expr_size to calculate the size of the value of an
 381      expression in a language-dependent way.  Returns a tree for the size
 382      in bytes.  A frontend can call lhd_expr_size to get the default
 383      semantics in cases that it doesn't want to handle specially.  */
 384   tree (*expr_size) (const_tree);
 385
 386   /* Convert a character from the host's to the target's character
 387      set.  The character should be in what C calls the "basic source
 388      character set" (roughly, the set of characters defined by plain
 389      old ASCII).  The default is to return the character unchanged,
 390      which is correct in most circumstances.  Note that both argument
 391      and result should be sign-extended under -fsigned-char,
 392      zero-extended under -fno-signed-char.  */
 393   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 394
 395   /* Pointers to machine-independent attribute tables, for front ends
 396      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 397      table of attributes specific to the language, a table of
 398      attributes common to two or more languages (to allow easy
 399      sharing), and a table of attributes for checking formats.  */
 400   const struct attribute_spec *attribute_table;
 401   const struct attribute_spec *common_attribute_table;
 402   const struct attribute_spec *format_attribute_table;
 403
 404   /* Function-related language hooks.  */
 405   struct lang_hooks_for_functions function;
 406
 407   struct lang_hooks_for_tree_inlining tree_inlining;
 408
 409   struct lang_hooks_for_callgraph callgraph;
 410
 411   struct lang_hooks_for_tree_dump tree_dump;
 412
 413   struct lang_hooks_for_decls decls;
 414
 415   struct lang_hooks_for_types types;
 416
 417   /* Perform language-specific gimplification on the argument.  Returns an
 418      enum gimplify_status, though we can't see that type here.  */
 419   int (*gimplify_expr) (tree *, tree *, tree *);
 420
 421   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 422      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 423   tree (*fold_obj_type_ref) (tree, tree);
 424
 425   /* Do language specific processing in the builtin function DECL  */
 426   tree (*builtin_function) (tree decl);
 427
 428   /* Used to set up the tree_contains_structure array for a frontend. */
 429   void (*init_ts) (void);
 430
 431   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 432      to a contained expression or DECL, possibly updating *TC, *TI or
 433      *SE if in the process TREE_CONSTANT, TREE_INVARIANT or
 434      TREE_SIDE_EFFECTS need updating.  */
 435   tree (*expr_to_decl) (tree expr, bool *tc, bool *ti, bool *se);
 436
 437   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 438      and langhooks.c accordingly.  */
 439 };
 440
 441 /* Each front end provides its own.  */
 442 extern const struct lang_hooks lang_hooks;
 443 extern tree add_builtin_function (const char *name, tree type,
 444                                   int function_code, enum built_in_class cl,
 445                                   const char *library_name,
 446                                   tree attrs);
 447
 448 #endif /* GCC_LANG_HOOKS_H */