gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright 2001, 2002, 2003, 2004, 2005 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 /* A print hook for print_tree ().  */
  29 typedef void (*lang_print_tree_hook) (FILE *, tree, int indent);
  30
  31 /* The following hooks are documented in langhooks.c.  Must not be
  32    NULL.  */
  33
  34 struct lang_hooks_for_tree_inlining
  35 {
  36   tree (*walk_subtrees) (tree *, int *,
  37                          tree (*) (tree *, int *, void *),
  38                          void *, struct pointer_set_t*);
  39   int (*cannot_inline_tree_fn) (tree *);
  40   int (*disregard_inline_limits) (tree);
  41   tree (*add_pending_fn_decls) (void *, tree);
  42   int (*auto_var_in_fn_p) (tree, tree);
  43   int (*anon_aggr_type_p) (tree);
  44   bool (*var_mod_type_p) (tree, tree);
  45   int (*start_inlining) (tree);
  46   void (*end_inlining) (tree);
  47   tree (*convert_parm_for_inlining) (tree, tree, tree, int);
  48 };
  49
  50 struct lang_hooks_for_callgraph
  51 {
  52   /* The node passed is a language-specific tree node.  If its contents
  53      are relevant to use of other declarations, mark them.  */
  54   tree (*analyze_expr) (tree *, int *, tree);
  55
  56   /* Produce RTL for function passed as argument.  */
  57   void (*expand_function) (tree);
  58 };
  59
  60 /* Lang hooks for management of language-specific data or status
  61    when entering / leaving functions etc.  */
  62 struct lang_hooks_for_functions
  63 {
  64   /* Called when entering a function.  */
  65   void (*init) (struct function *);
  66
  67   /* Called when leaving a function.  */
  68   void (*final) (struct function *);
  69
  70   /* Called when entering a nested function.  */
  71   void (*enter_nested) (struct function *);
  72
  73   /* Called when leaving a nested function.  */
  74   void (*leave_nested) (struct function *);
  75
  76   /* Determines if it's ok for a function to have no noreturn attribute.  */
  77   bool (*missing_noreturn_ok_p) (tree);
  78 };
  79
  80 /* The following hooks are used by tree-dump.c.  */
  81
  82 struct lang_hooks_for_tree_dump
  83 {
  84   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  85      does not want the usual dumping of the second argument.  */
  86   bool (*dump_tree) (void *, tree);
  87
  88   /* Determine type qualifiers in a language-specific way.  */
  89   int (*type_quals) (tree);
  90 };
  91
  92 /* Hooks related to types.  */
  93
  94 struct lang_hooks_for_types
  95 {
  96   /* Return a new type (with the indicated CODE), doing whatever
  97      language-specific processing is required.  */
  98   tree (*make_type) (enum tree_code);
  99
 100   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
 101      mode.  */
 102   tree (*type_for_mode) (enum machine_mode, int);
 103
 104   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
 105      integer type with at least that precision.  */
 106   tree (*type_for_size) (unsigned, int);
 107
 108   /* Given an integer type T, return a type like T but unsigned.
 109      If T is unsigned, the value is T.  */
 110   tree (*unsigned_type) (tree);
 111
 112   /* Given an integer type T, return a type like T but signed.
 113      If T is signed, the value is T.  */
 114   tree (*signed_type) (tree);
 115
 116   /* Return a type the same as TYPE except unsigned or signed
 117      according to UNSIGNEDP.  */
 118   tree (*signed_or_unsigned_type) (int, tree);
 119
 120   /* Given a type, apply default promotions to unnamed function
 121      arguments and return the new type.  Return the same type if no
 122      change.  Required by any language that supports variadic
 123      arguments.  The default hook dies.  */
 124   tree (*type_promotes_to) (tree);
 125
 126   /* Register TYPE as a builtin type with the indicated NAME.  The
 127      TYPE is placed in the outermost lexical scope.  The semantics
 128      should be analogous to:
 129
 130        typedef TYPE NAME;
 131
 132      in C.  The default hook ignores the declaration.  */
 133   void (*register_builtin_type) (tree, const char *);
 134
 135   /* This routine is called in tree.c to print an error message for
 136      invalid use of an incomplete type.  VALUE is the expression that
 137      was used (or 0 if that isn't known) and TYPE is the type that was
 138      invalid.  */
 139   void (*incomplete_type_error) (tree value, tree type);
 140
 141   /* Called from assign_temp to return the maximum size, if there is one,
 142      for a type.  */
 143   tree (*max_size) (tree);
 144
 145   /* Nonzero if types that are identical are to be hashed so that only
 146      one copy is kept.  If a language requires unique types for each
 147      user-specified type, such as Ada, this should be set to TRUE.  */
 148   bool hash_types;
 149 };
 150
 151 /* Language hooks related to decls and the symbol table.  */
 152
 153 struct lang_hooks_for_decls
 154 {
 155   /* Returns nonzero if we are in the global binding level.  Ada
 156      returns -1 for an undocumented reason used in stor-layout.c.  */
 157   int (*global_bindings_p) (void);
 158
 159   /* Insert BLOCK at the end of the list of subblocks of the
 160      current binding level.  This is used when a BIND_EXPR is expanded,
 161      to handle the BLOCK node inside the BIND_EXPR.  */
 162   void (*insert_block) (tree);
 163
 164   /* Function to add a decl to the current scope level.  Takes one
 165      argument, a decl to add.  Returns that decl, or, if the same
 166      symbol is already declared, may return a different decl for that
 167      name.  */
 168   tree (*pushdecl) (tree);
 169
 170   /* Returns the chain of decls so far in the current scope level.  */
 171   tree (*getdecls) (void);
 172
 173   /* Returns true when we should warn for an unused global DECL.
 174      We will already have checked that it has static binding.  */
 175   bool (*warn_unused_global) (tree);
 176
 177   /* Obtain a list of globals and do final output on them at end
 178      of compilation */
 179   void (*final_write_globals) (void);
 180
 181   /* Do necessary preparations before assemble_variable can proceed.  */
 182   void (*prepare_assemble_variable) (tree);
 183
 184   /* True if this decl may be called via a sibcall.  */
 185   bool (*ok_for_sibcall) (tree);
 186
 187   /* Return the COMDAT group into which this DECL should be placed.
 188      It is known that the DECL belongs in *some* COMDAT group when
 189      this hook is called.  The return value will be used immediately,
 190      but not explicitly deallocated, so implementations should not use
 191      xmalloc to allocate the string returned.  (Typically, the return
 192      value will be the string already stored in an
 193      IDENTIFIER_NODE.)  */
 194   const char * (*comdat_group) (tree);
 195 };
 196
 197 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 198
 199 struct lang_hooks
 200 {
 201   /* String identifying the front end.  e.g. "GNU C++".  */
 202   const char *name;
 203
 204   /* sizeof (struct lang_identifier), so make_node () creates
 205      identifier nodes long enough for the language-specific slots.  */
 206   size_t identifier_size;
 207
 208   /* Determines the size of any language-specific tcc_constant or
 209      tcc_exceptional nodes.  Since it is called from make_node, the
 210      only information available is the tree code.  Expected to die
 211      on unrecognized codes.  */
 212   size_t (*tree_size) (enum tree_code);
 213
 214   /* The first callback made to the front end, for simple
 215      initialization needed before any calls to handle_option.  Return
 216      the language mask to filter the switch array with.  */
 217   unsigned int (*init_options) (unsigned int argc, const char **argv);
 218
 219   /* Callback used to perform language-specific initialization for the
 220      global diagnostic context structure.  */
 221   void (*initialize_diagnostics) (struct diagnostic_context *);
 222
 223   /* Handle the switch CODE, which has real type enum opt_code from
 224      options.h.  If the switch takes an argument, it is passed in ARG
 225      which points to permanent storage.  The handler is responsible for
 226      checking whether ARG is NULL, which indicates that no argument
 227      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 228      for the positive and negative forms respectively.
 229
 230      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 231      valid and should not be treated as language-independent too.  */
 232   int (*handle_option) (size_t code, const char *arg, int value);
 233
 234   /* Return false to use the default complaint about a missing
 235      argument, otherwise output a complaint and return true.  */
 236   bool (*missing_argument) (const char *opt, size_t code);
 237
 238   /* Called when all command line options have been parsed to allow
 239      further processing and initialization
 240
 241      Should return true to indicate that a compiler back-end is
 242      not required, such as with the -E option.
 243
 244      If errorcount is nonzero after this call the compiler exits
 245      immediately and the finish hook is not called.  */
 246   bool (*post_options) (const char **);
 247
 248   /* Called after post_options to initialize the front end.  Return
 249      false to indicate that no further compilation be performed, in
 250      which case the finish hook is called immediately.  */
 251   bool (*init) (void);
 252
 253   /* Called at the end of compilation, as a finalizer.  */
 254   void (*finish) (void);
 255
 256   /* Parses the entire file.  The argument is nonzero to cause bison
 257      parsers to dump debugging information during parsing.  */
 258   void (*parse_file) (int);
 259
 260   /* Called immediately after parsing to clear the binding stack.  */
 261   void (*clear_binding_stack) (void);
 262
 263   /* Called to obtain the alias set to be used for an expression or type.
 264      Returns -1 if the language does nothing special for it.  */
 265   HOST_WIDE_INT (*get_alias_set) (tree);
 266
 267   /* Called with an expression that is to be processed as a constant.
 268      Returns either the same expression or a language-independent
 269      constant equivalent to its input.  */
 270   tree (*expand_constant) (tree);
 271
 272   /* Called by expand_expr for language-specific tree codes.
 273      Fourth argument is actually an enum expand_modifier.  */
 274   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 275
 276   /* Called by expand_expr to generate the definition of a decl.  Returns
 277      1 if handled, 0 otherwise.  */
 278   int (*expand_decl) (tree);
 279
 280   /* Hook called by safe_from_p for language-specific tree codes.  It is
 281      up to the language front-end to install a hook if it has any such
 282      codes that safe_from_p needs to know about.  Since same_from_p will
 283      recursively explore the TREE_OPERANDs of an expression, this hook
 284      should not reexamine those pieces.  This routine may recursively
 285      call safe_from_p; it should always pass `0' as the TOP_P
 286      parameter.  */
 287   int (*safe_from_p) (rtx, tree);
 288
 289   /* Function to finish handling an incomplete decl at the end of
 290      compilation.  Default hook is does nothing.  */
 291   void (*finish_incomplete_decl) (tree);
 292
 293   /* Mark EXP saying that we need to be able to take the address of
 294      it; it should not be allocated in a register.  Return true if
 295      successful.  */
 296   bool (*mark_addressable) (tree);
 297
 298   /* Hook called by staticp for language-specific tree codes.  */
 299   tree (*staticp) (tree);
 300
 301   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 302      DECL_NODE with a newly GC-allocated copy.  */
 303   void (*dup_lang_specific_decl) (tree);
 304
 305   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 306      thing that the assembler should talk about, set
 307      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 308      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 309      assembler does not talk about it.  */
 310   void (*set_decl_assembler_name) (tree);
 311
 312   /* Return nonzero if fold-const is free to use bit-field
 313      optimizations, for instance in fold_truthop().  */
 314   bool (*can_use_bit_fields_p) (void);
 315
 316   /* Nonzero if operations on types narrower than their mode should
 317      have their results reduced to the precision of the type.  */
 318   bool reduce_bit_field_operations;
 319
 320   /* Nonzero if this front end does not generate a dummy BLOCK between
 321      the outermost scope of the function and the FUNCTION_DECL.  See
 322      is_body_block in stmt.c, and its callers.  */
 323   bool no_body_blocks;
 324
 325   /* The front end can add its own statistics to -fmem-report with
 326      this hook.  It should output to stderr.  */
 327   void (*print_statistics) (void);
 328
 329   /* Called by print_tree when there is a tree of class tcc_exceptional
 330      that it doesn't know how to display.  */
 331   lang_print_tree_hook print_xnode;
 332
 333   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 334      and IDENTIFIER_NODE nodes.  */
 335   lang_print_tree_hook print_decl;
 336   lang_print_tree_hook print_type;
 337   lang_print_tree_hook print_identifier;
 338
 339   /* Computes the name to use to print a declaration.  DECL is the
 340      non-NULL declaration in question.  VERBOSITY determines what
 341      information will be printed: 0: DECL_NAME, demangled as
 342      necessary.  1: and scope information.  2: and any other
 343      information that might be interesting, such as function parameter
 344      types in C++.  */
 345   const char *(*decl_printable_name) (tree decl, int verbosity);
 346
 347   /* This compares two types for equivalence ("compatible" in C-based languages).
 348      This routine should only return 1 if it is sure.  It should not be used
 349      in contexts where erroneously returning 0 causes problems.  */
 350   int (*types_compatible_p) (tree x, tree y);
 351
 352   /* Given a CALL_EXPR, return a function decl that is its target.  */
 353   tree (*lang_get_callee_fndecl) (tree);
 354
 355   /* Called by report_error_function to print out function name.  */
 356   void (*print_error_function) (struct diagnostic_context *, const char *);
 357
 358   /* Called from expr_size to calculate the size of the value of an
 359      expression in a language-dependent way.  Returns a tree for the size
 360      in bytes.  A frontend can call lhd_expr_size to get the default
 361      semantics in cases that it doesn't want to handle specially.  */
 362   tree (*expr_size) (tree);
 363
 364   /* Convert a character from the host's to the target's character
 365      set.  The character should be in what C calls the "basic source
 366      character set" (roughly, the set of characters defined by plain
 367      old ASCII).  The default is to return the character unchanged,
 368      which is correct in most circumstances.  Note that both argument
 369      and result should be sign-extended under -fsigned-char,
 370      zero-extended under -fno-signed-char.  */
 371   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 372
 373   /* Pointers to machine-independent attribute tables, for front ends
 374      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 375      table of attributes specific to the language, a table of
 376      attributes common to two or more languages (to allow easy
 377      sharing), and a table of attributes for checking formats.  */
 378   const struct attribute_spec *attribute_table;
 379   const struct attribute_spec *common_attribute_table;
 380   const struct attribute_spec *format_attribute_table;
 381
 382   /* Function-related language hooks.  */
 383   struct lang_hooks_for_functions function;
 384
 385   struct lang_hooks_for_tree_inlining tree_inlining;
 386
 387   struct lang_hooks_for_callgraph callgraph;
 388
 389   struct lang_hooks_for_tree_dump tree_dump;
 390
 391   struct lang_hooks_for_decls decls;
 392
 393   struct lang_hooks_for_types types;
 394
 395   /* Perform language-specific gimplification on the argument.  Returns an
 396      enum gimplify_status, though we can't see that type here.  */
 397   int (*gimplify_expr) (tree *, tree *, tree *);
 398
 399   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 400      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 401   tree (*fold_obj_type_ref) (tree, tree);
 402
 403   /* Return a definition for a builtin function named NAME and whose data type
 404      is TYPE.  TYPE should be a function type with argument types.
 405      FUNCTION_CODE tells later passes how to compile calls to this function.
 406      See tree.h for its possible values.
 407
 408      If LIBRARY_NAME is nonzero, use that for DECL_ASSEMBLER_NAME,
 409      the name to be called if we can't opencode the function.  If
 410      ATTRS is nonzero, use that for the function's attribute list.  */
 411   tree (*builtin_function) (const char *name, tree type, int function_code,
 412                             enum built_in_class bt_class,
 413                             const char *library_name, tree attrs);
 414
 415   /* Used to set up the tree_contains_structure array for a frontend. */
 416   void (*init_ts) (void);
 417
 418   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 419      to a contained expression or DECL, possibly updating *TC, *TI or
 420      *SE if in the process TREE_CONSTANT, TREE_INVARIANT or
 421      TREE_SIDE_EFFECTS need updating.  */
 422   tree (*expr_to_decl) (tree expr, bool *tc, bool *ti, bool *se);
 423
 424   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 425      and langhooks.c accordingly.  */
 426 };
 427
 428 /* Each front end provides its own.  */
 429 extern const struct lang_hooks lang_hooks;
 430
 431 #endif /* GCC_LANG_HOOKS_H */