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