gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright 2001, 2002, 2003, 2004 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, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, 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 *, void *);
  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   tree (*copy_res_decl_for_inlining) (tree, tree, tree,
  44                                       void *, int *, 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   int (*estimate_num_insns) (tree);
  51 };
  52
  53 struct lang_hooks_for_callgraph
  54 {
  55   /* The node passed is a language-specific tree node.  If its contents
  56      are relevant to use of other declarations, mark them.  */
  57   tree (*analyze_expr) (tree *, int *, tree);
  58
  59   /* Produce RTL for function passed as argument.  */
  60   void (*expand_function) (tree);
  61 };
  62
  63 /* Lang hooks for management of language-specific data or status
  64    when entering / leaving functions etc.  */
  65 struct lang_hooks_for_functions
  66 {
  67   /* Called when entering a function.  */
  68   void (*init) (struct function *);
  69
  70   /* Called when leaving a function.  */
  71   void (*final) (struct function *);
  72
  73   /* Called when entering a nested function.  */
  74   void (*enter_nested) (struct function *);
  75
  76   /* Called when leaving a nested function.  */
  77   void (*leave_nested) (struct function *);
  78
  79   /* Determines if it's ok for a function to have no noreturn attribute.  */
  80   bool (*missing_noreturn_ok_p) (tree);
  81 };
  82
  83 /* The following hooks are used by tree-dump.c.  */
  84
  85 struct lang_hooks_for_tree_dump
  86 {
  87   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  88      does not want the usual dumping of the second argument.  */
  89   bool (*dump_tree) (void *, tree);
  90
  91   /* Determine type qualifiers in a language-specific way.  */
  92   int (*type_quals) (tree);
  93 };
  94
  95 /* Hooks related to types.  */
  96
  97 struct lang_hooks_for_types
  98 {
  99   /* Return a new type (with the indicated CODE), doing whatever
 100      language-specific processing is required.  */
 101   tree (*make_type) (enum tree_code);
 102
 103   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
 104      mode.  */
 105   tree (*type_for_mode) (enum machine_mode, int);
 106
 107   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
 108      integer type with at least that precision.  */
 109   tree (*type_for_size) (unsigned, int);
 110
 111   /* Given an integer type T, return a type like T but unsigned.
 112      If T is unsigned, the value is T.  */
 113   tree (*unsigned_type) (tree);
 114
 115   /* Given an integer type T, return a type like T but signed.
 116      If T is signed, the value is T.  */
 117   tree (*signed_type) (tree);
 118
 119   /* Return a type the same as TYPE except unsigned or signed
 120      according to UNSIGNEDP.  */
 121   tree (*signed_or_unsigned_type) (int, tree);
 122
 123   /* Given a type, apply default promotions to unnamed function
 124      arguments and return the new type.  Return the same type if no
 125      change.  Required by any language that supports variadic
 126      arguments.  The default hook aborts.  */
 127   tree (*type_promotes_to) (tree);
 128
 129   /* Register TYPE as a builtin type with the indicated NAME.  The
 130      TYPE is placed in the outermost lexical scope.  The semantics
 131      should be analogous to:
 132
 133        typedef TYPE NAME;
 134
 135      in C.  The default hook ignores the declaration.  */
 136   void (*register_builtin_type) (tree, const char *);
 137
 138   /* This routine is called in tree.c to print an error message for
 139      invalid use of an incomplete type.  VALUE is the expression that
 140      was used (or 0 if that isn't known) and TYPE is the type that was
 141      invalid.  */
 142   void (*incomplete_type_error) (tree value, tree type);
 143
 144   /* Called from assign_temp to return the maximum size, if there is one,
 145      for a type.  */
 146   tree (*max_size) (tree);
 147
 148   /* Nonzero if types that are identical are to be hashed so that only
 149      one copy is kept.  If a language requires unique types for each
 150      user-specified type, such as Ada, this should be set to TRUE.  */
 151   bool hash_types;
 152 };
 153
 154 /* Language hooks related to decls and the symbol table.  */
 155
 156 struct lang_hooks_for_decls
 157 {
 158   /* Enter a new lexical scope.  Argument is always zero when called
 159      from outside the front end.  */
 160   void (*pushlevel) (int);
 161
 162   /* Exit a lexical scope and return a BINDING for that scope.
 163      Takes three arguments:
 164      KEEP -- nonzero if there were declarations in this scope.
 165      REVERSE -- reverse the order of decls before returning them.
 166      FUNCTIONBODY -- nonzero if this level is the body of a function.  */
 167   tree (*poplevel) (int, int, int);
 168
 169   /* Returns nonzero if we are in the global binding level.  Ada
 170      returns -1 for an undocumented reason used in stor-layout.c.  */
 171   int (*global_bindings_p) (void);
 172
 173   /* Insert BLOCK at the end of the list of subblocks of the
 174      current binding level.  This is used when a BIND_EXPR is expanded,
 175      to handle the BLOCK node inside the BIND_EXPR.  */
 176   void (*insert_block) (tree);
 177
 178   /* Set the BLOCK node for the current scope level.  */
 179   void (*set_block) (tree);
 180
 181   /* Function to add a decl to the current scope level.  Takes one
 182      argument, a decl to add.  Returns that decl, or, if the same
 183      symbol is already declared, may return a different decl for that
 184      name.  */
 185   tree (*pushdecl) (tree);
 186
 187   /* Returns the chain of decls so far in the current scope level.  */
 188   tree (*getdecls) (void);
 189
 190   /* Returns true when we should warn for an unused global DECL.
 191      We will already have checked that it has static binding.  */
 192   bool (*warn_unused_global) (tree);
 193
 194   /* Obtain a list of globals and do final output on them at end
 195      of compilation */
 196   void (*final_write_globals) (void);
 197
 198   /* Do necessary preparations before assemble_variable can proceed.  */
 199   void (*prepare_assemble_variable) (tree);
 200
 201   /* True if this decl may be called via a sibcall.  */
 202   bool (*ok_for_sibcall) (tree);
 203 };
 204
 205 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 206
 207 struct lang_hooks
 208 {
 209   /* String identifying the front end.  e.g. "GNU C++".  */
 210   const char *name;
 211
 212   /* sizeof (struct lang_identifier), so make_node () creates
 213      identifier nodes long enough for the language-specific slots.  */
 214   size_t identifier_size;
 215
 216   /* Determines the size of any language-specific 'x' or 'c' nodes.
 217      Since it is called from make_node, the only information available
 218      is the tree code.  Expected to abort on unrecognized codes.  */
 219   size_t (*tree_size) (enum tree_code);
 220
 221   /* The first callback made to the front end, for simple
 222      initialization needed before any calls to handle_option.  Return
 223      the language mask to filter the switch array with.  */
 224   unsigned int (*init_options) (unsigned int argc, const char **argv);
 225
 226   /* Callback used to perform language-specific initialization for the
 227      global diagnostic context structure.  */
 228   void (*initialize_diagnostics) (struct diagnostic_context *);
 229
 230   /* Handle the switch CODE, which has real type enum opt_code from
 231      options.h.  If the switch takes an argument, it is passed in ARG
 232      which points to permanent storage.  The handler is responsible for
 233      checking whether ARG is NULL, which indicates that no argument
 234      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 235      for the positive and negative forms respectively.
 236
 237      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 238      valid and should not be treated as language-independent too.  */
 239   int (*handle_option) (size_t code, const char *arg, int value);
 240
 241   /* Return false to use the default complaint about a missing
 242      argument, otherwise output a complaint and return true.  */
 243   bool (*missing_argument) (const char *opt, size_t code);
 244
 245   /* Called when all command line options have been parsed to allow
 246      further processing and initialization
 247
 248      Should return true to indicate that a compiler back-end is
 249      not required, such as with the -E option.
 250
 251      If errorcount is nonzero after this call the compiler exits
 252      immediately and the finish hook is not called.  */
 253   bool (*post_options) (const char **);
 254
 255   /* Called after post_options to initialize the front end.  Return
 256      false to indicate that no further compilation be performed, in
 257      which case the finish hook is called immediately.  */
 258   bool (*init) (void);
 259
 260   /* Called at the end of compilation, as a finalizer.  */
 261   void (*finish) (void);
 262
 263   /* Parses the entire file.  The argument is nonzero to cause bison
 264      parsers to dump debugging information during parsing.  */
 265   void (*parse_file) (int);
 266
 267   /* Called immediately after parsing to clear the binding stack.  */
 268   void (*clear_binding_stack) (void);
 269
 270   /* Called to obtain the alias set to be used for an expression or type.
 271      Returns -1 if the language does nothing special for it.  */
 272   HOST_WIDE_INT (*get_alias_set) (tree);
 273
 274   /* Called with an expression that is to be processed as a constant.
 275      Returns either the same expression or a language-independent
 276      constant equivalent to its input.  */
 277   tree (*expand_constant) (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   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 288      operation.
 289
 290      This preparation consists of taking the ordinary representation
 291      of an expression expr and producing a valid tree boolean
 292      expression describing whether expr is nonzero.  We could simply
 293      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 294      but we optimize comparisons, &&, ||, and !.
 295
 296      The result should be an expression of boolean type (if not an
 297      error_mark_node).  */
 298   tree (*truthvalue_conversion) (tree);
 299
 300   /* Hook called by safe_from_p for language-specific tree codes.  It is
 301      up to the language front-end to install a hook if it has any such
 302      codes that safe_from_p needs to know about.  Since same_from_p will
 303      recursively explore the TREE_OPERANDs of an expression, this hook
 304      should not reexamine those pieces.  This routine may recursively
 305      call safe_from_p; it should always pass `0' as the TOP_P
 306      parameter.  */
 307   int (*safe_from_p) (rtx, 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   /* Function used by unsafe_for_reeval.  A non-negative number is
 314      returned directly from unsafe_for_reeval, a negative number falls
 315      through.  The default hook returns a negative number.  */
 316   int (*unsafe_for_reeval) (tree);
 317
 318   /* Mark EXP saying that we need to be able to take the address of
 319      it; it should not be allocated in a register.  Return true if
 320      successful.  */
 321   bool (*mark_addressable) (tree);
 322
 323   /* Hook called by staticp for language-specific tree codes.  */
 324   int (*staticp) (tree);
 325
 326   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 327      DECL_NODE with a newly GC-allocated copy.  */
 328   void (*dup_lang_specific_decl) (tree);
 329
 330   /* Called before its argument, an UNSAVE_EXPR, is to be
 331      unsaved.  Modify it in-place so that all the evaluate only once
 332      things are cleared out.  */
 333   tree (*unsave_expr_now) (tree);
 334
 335   /* Called by expand_expr to build and return the cleanup-expression
 336      for the passed TARGET_EXPR.  Return NULL if there is none.  */
 337   tree (*maybe_build_cleanup) (tree);
 338
 339   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 340      thing that the assembler should talk about, set
 341      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 342      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 343      assembler does not talk about it.  */
 344   void (*set_decl_assembler_name) (tree);
 345
 346   /* Return nonzero if fold-const is free to use bit-field
 347      optimizations, for instance in fold_truthop().  */
 348   bool (*can_use_bit_fields_p) (void);
 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 TYPE_READONLY and TREE_READONLY should always be honored.  */
 355   bool honor_readonly;
 356
 357   /* Nonzero if this front end does not generate a dummy BLOCK between
 358      the outermost scope of the function and the FUNCTION_DECL.  See
 359      is_body_block in stmt.c, and its callers.  */
 360   bool no_body_blocks;
 361
 362   /* The front end can add its own statistics to -fmem-report with
 363      this hook.  It should output to stderr.  */
 364   void (*print_statistics) (void);
 365
 366   /* Called by print_tree when there is a tree of class 'x' that it
 367      doesn't know how to display.  */
 368   lang_print_tree_hook print_xnode;
 369
 370   /* Called to print language-dependent parts of a class 'd', class
 371      't', and IDENTIFIER_NODE nodes.  */
 372   lang_print_tree_hook print_decl;
 373   lang_print_tree_hook print_type;
 374   lang_print_tree_hook print_identifier;
 375
 376   /* Computes the name to use to print a declaration.  DECL is the
 377      non-NULL declaration in question.  VERBOSITY determines what
 378      information will be printed: 0: DECL_NAME, demangled as
 379      necessary.  1: and scope information.  2: and any other
 380      information that might be interesting, such as function parameter
 381      types in C++.  */
 382   const char *(*decl_printable_name) (tree decl, int verbosity);
 383
 384   /* This compares two types for equivalence ("compatible" in C-based languages).
 385      This routine should only return 1 if it is sure.  It should not be used
 386      in contexts where erroneously returning 0 causes problems.  */
 387   int (*types_compatible_p) (tree x, tree y);
 388
 389   /* Given a CALL_EXPR, return a function decl that is its target.  */
 390   tree (*lang_get_callee_fndecl) (tree);
 391
 392   /* Called by report_error_function to print out function name.  */
 393   void (*print_error_function) (struct diagnostic_context *, const char *);
 394
 395   /* Called from expr_size to calculate the size of the value of an
 396      expression in a language-dependent way.  Returns a tree for the size
 397      in bytes.  A frontend can call lhd_expr_size to get the default
 398      semantics in cases that it doesn't want to handle specially.  */
 399   tree (*expr_size) (tree);
 400
 401   /* Update lang specific fields after duplicating function body.  */
 402   void (*update_decl_after_saving) (tree, void *);
 403
 404   /* Pointers to machine-independent attribute tables, for front ends
 405      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 406      table of attributes specific to the language, a table of
 407      attributes common to two or more languages (to allow easy
 408      sharing), and a table of attributes for checking formats.  */
 409   const struct attribute_spec *attribute_table;
 410   const struct attribute_spec *common_attribute_table;
 411   const struct attribute_spec *format_attribute_table;
 412
 413   /* Function-related language hooks.  */
 414   struct lang_hooks_for_functions function;
 415
 416   struct lang_hooks_for_tree_inlining tree_inlining;
 417
 418   struct lang_hooks_for_callgraph callgraph;
 419
 420   struct lang_hooks_for_tree_dump tree_dump;
 421
 422   struct lang_hooks_for_decls decls;
 423
 424   struct lang_hooks_for_types types;
 425
 426   /* Perform language-specific gimplification on the argument.  Returns an
 427      enum gimplify_status, though we can't see that type here.  */
 428   int (*gimplify_expr) (tree *, tree *, tree *);
 429
 430   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 431      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 432   tree (*fold_obj_type_ref) (tree, tree);
 433
 434   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 435      and langhooks.c accordingly.  */
 436 };
 437
 438 /* Each front end provides its own.  */
 439 extern const struct lang_hooks lang_hooks;
 440
 441 #endif /* GCC_LANG_HOOKS_H */