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);
  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   /* Nonzero if types that are identical are to be hashed so that only
 145      one copy is kept.  If a language requires unique types for each
 146      user-specified type, such as Ada, this should be set to TRUE.  */
 147   bool hash_types;
 148 };
 149
 150 /* Language hooks related to decls and the symbol table.  */
 151
 152 struct lang_hooks_for_decls
 153 {
 154   /* Enter a new lexical scope.  Argument is always zero when called
 155      from outside the front end.  */
 156   void (*pushlevel) (int);
 157
 158   /* Exit a lexical scope and return a BINDING for that scope.
 159      Takes three arguments:
 160      KEEP -- nonzero if there were declarations in this scope.
 161      REVERSE -- reverse the order of decls before returning them.
 162      FUNCTIONBODY -- nonzero if this level is the body of a function.  */
 163   tree (*poplevel) (int, int, int);
 164
 165   /* Returns nonzero if we are in the global binding level.  Ada
 166      returns -1 for an undocumented reason used in stor-layout.c.  */
 167   int (*global_bindings_p) (void);
 168
 169   /* Insert BLOCK at the end of the list of subblocks of the
 170      current binding level.  This is used when a BIND_EXPR is expanded,
 171      to handle the BLOCK node inside the BIND_EXPR.  */
 172   void (*insert_block) (tree);
 173
 174   /* Set the BLOCK node for the current scope level.  */
 175   void (*set_block) (tree);
 176
 177   /* Function to add a decl to the current scope level.  Takes one
 178      argument, a decl to add.  Returns that decl, or, if the same
 179      symbol is already declared, may return a different decl for that
 180      name.  */
 181   tree (*pushdecl) (tree);
 182
 183   /* Returns the chain of decls so far in the current scope level.  */
 184   tree (*getdecls) (void);
 185
 186   /* Returns true when we should warn for an unused global DECL.
 187      We will already have checked that it has static binding.  */
 188   bool (*warn_unused_global) (tree);
 189
 190   /* Obtain a list of globals and do final output on them at end
 191      of compilation */
 192   void (*final_write_globals) (void);
 193
 194   /* Do necessary preparations before assemble_variable can proceed.  */
 195   void (*prepare_assemble_variable) (tree);
 196
 197   /* True if this decl may be called via a sibcall.  */
 198   bool (*ok_for_sibcall) (tree);
 199 };
 200
 201 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 202
 203 struct lang_hooks
 204 {
 205   /* String identifying the front end.  e.g. "GNU C++".  */
 206   const char *name;
 207
 208   /* sizeof (struct lang_identifier), so make_node () creates
 209      identifier nodes long enough for the language-specific slots.  */
 210   size_t identifier_size;
 211
 212   /* Determines the size of any language-specific 'x' or 'c' nodes.
 213      Since it is called from make_node, the only information available
 214      is the tree code.  Expected to abort on unrecognized codes.  */
 215   size_t (*tree_size) (enum tree_code);
 216
 217   /* The first callback made to the front end, for simple
 218      initialization needed before any calls to handle_option.  Return
 219      the language mask to filter the switch array with.  */
 220   unsigned int (*init_options) (unsigned int argc, const char **argv);
 221
 222   /* Callback used to perform language-specific initialization for the
 223      global diagnostic context structure.  */
 224   void (*initialize_diagnostics) (struct diagnostic_context *);
 225
 226   /* Handle the switch CODE, which has real type enum opt_code from
 227      options.h.  If the switch takes an argument, it is passed in ARG
 228      which points to permanent storage.  The handler is responsible for
 229      checking whether ARG is NULL, which indicates that no argument
 230      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 231      for the positive and negative forms respectively.
 232
 233      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 234      valid and should not be treated as language-independent too.  */
 235   int (*handle_option) (size_t code, const char *arg, int value);
 236
 237   /* Return false to use the default complaint about a missing
 238      argument, otherwise output a complaint and return true.  */
 239   bool (*missing_argument) (const char *opt, size_t code);
 240
 241   /* Called when all command line options have been parsed to allow
 242      further processing and initialization
 243
 244      Should return true to indicate that a compiler back-end is
 245      not required, such as with the -E option.
 246
 247      If errorcount is nonzero after this call the compiler exits
 248      immediately and the finish hook is not called.  */
 249   bool (*post_options) (const char **);
 250
 251   /* Called after post_options to initialize the front end.  Return
 252      false to indicate that no further compilation be performed, in
 253      which case the finish hook is called immediately.  */
 254   bool (*init) (void);
 255
 256   /* Called at the end of compilation, as a finalizer.  */
 257   void (*finish) (void);
 258
 259   /* Parses the entire file.  The argument is nonzero to cause bison
 260      parsers to dump debugging information during parsing.  */
 261   void (*parse_file) (int);
 262
 263   /* Called immediately after parsing to clear the binding stack.  */
 264   void (*clear_binding_stack) (void);
 265
 266   /* Called to obtain the alias set to be used for an expression or type.
 267      Returns -1 if the language does nothing special for it.  */
 268   HOST_WIDE_INT (*get_alias_set) (tree);
 269
 270   /* Called with an expression that is to be processed as a constant.
 271      Returns either the same expression or a language-independent
 272      constant equivalent to its input.  */
 273   tree (*expand_constant) (tree);
 274
 275   /* Called by expand_expr for language-specific tree codes.
 276      Fourth argument is actually an enum expand_modifier.  */
 277   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 278
 279   /* Called by expand_expr to generate the definition of a decl.  Returns
 280      1 if handled, 0 otherwise.  */
 281   int (*expand_decl) (tree);
 282
 283   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 284      operation.
 285
 286      This preparation consists of taking the ordinary representation
 287      of an expression expr and producing a valid tree boolean
 288      expression describing whether expr is nonzero.  We could simply
 289      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 290      but we optimize comparisons, &&, ||, and !.
 291
 292      The result should be an expression of boolean type (if not an
 293      error_mark_node).  */
 294   tree (*truthvalue_conversion) (tree);
 295
 296   /* Hook called by safe_from_p for language-specific tree codes.  It is
 297      up to the language front-end to install a hook if it has any such
 298      codes that safe_from_p needs to know about.  Since same_from_p will
 299      recursively explore the TREE_OPERANDs of an expression, this hook
 300      should not reexamine those pieces.  This routine may recursively
 301      call safe_from_p; it should always pass `0' as the TOP_P
 302      parameter.  */
 303   int (*safe_from_p) (rtx, tree);
 304
 305   /* Function to finish handling an incomplete decl at the end of
 306      compilation.  Default hook is does nothing.  */
 307   void (*finish_incomplete_decl) (tree);
 308
 309   /* Function used by unsafe_for_reeval.  A non-negative number is
 310      returned directly from unsafe_for_reeval, a negative number falls
 311      through.  The default hook returns a negative number.  */
 312   int (*unsafe_for_reeval) (tree);
 313
 314   /* Mark EXP saying that we need to be able to take the address of
 315      it; it should not be allocated in a register.  Return true if
 316      successful.  */
 317   bool (*mark_addressable) (tree);
 318
 319   /* Hook called by staticp for language-specific tree codes.  */
 320   int (*staticp) (tree);
 321
 322   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 323      DECL_NODE with a newly GC-allocated copy.  */
 324   void (*dup_lang_specific_decl) (tree);
 325
 326   /* Called before its argument, an UNSAVE_EXPR, is to be
 327      unsaved.  Modify it in-place so that all the evaluate only once
 328      things are cleared out.  */
 329   tree (*unsave_expr_now) (tree);
 330
 331   /* Called by expand_expr to build and return the cleanup-expression
 332      for the passed TARGET_EXPR.  Return NULL if there is none.  */
 333   tree (*maybe_build_cleanup) (tree);
 334
 335   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 336      thing that the assembler should talk about, set
 337      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 338      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 339      assembler does not talk about it.  */
 340   void (*set_decl_assembler_name) (tree);
 341
 342   /* Return nonzero if fold-const is free to use bit-field
 343      optimizations, for instance in fold_truthop().  */
 344   bool (*can_use_bit_fields_p) (void);
 345
 346   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
 347   bool honor_readonly;
 348
 349   /* Nonzero if this front end does not generate a dummy BLOCK between
 350      the outermost scope of the function and the FUNCTION_DECL.  See
 351      is_body_block in stmt.c, and its callers.  */
 352   bool no_body_blocks;
 353
 354   /* The front end can add its own statistics to -fmem-report with
 355      this hook.  It should output to stderr.  */
 356   void (*print_statistics) (void);
 357
 358   /* Called by print_tree when there is a tree of class 'x' that it
 359      doesn't know how to display.  */
 360   lang_print_tree_hook print_xnode;
 361
 362   /* Called to print language-dependent parts of a class 'd', class
 363      't', and IDENTIFIER_NODE nodes.  */
 364   lang_print_tree_hook print_decl;
 365   lang_print_tree_hook print_type;
 366   lang_print_tree_hook print_identifier;
 367
 368   /* Computes the name to use to print a declaration.  DECL is the
 369      non-NULL declaration in question.  VERBOSITY determines what
 370      information will be printed: 0: DECL_NAME, demangled as
 371      necessary.  1: and scope information.  2: and any other
 372      information that might be interesting, such as function parameter
 373      types in C++.  */
 374   const char *(*decl_printable_name) (tree decl, int verbosity);
 375
 376   /* This compares two types for equivalence ("compatible" in C-based languages).
 377      This routine should only return 1 if it is sure.  It should not be used
 378      in contexts where erroneously returning 0 causes problems.  */
 379   int (*types_compatible_p) (tree x, tree y);
 380
 381   /* Given a CALL_EXPR, return a function decl that is its target.  */
 382   tree (*lang_get_callee_fndecl) (tree);
 383
 384   /* Called by report_error_function to print out function name.  */
 385   void (*print_error_function) (struct diagnostic_context *, const char *);
 386
 387   /* Called from expr_size to calculate the size of the value of an
 388      expression in a language-dependent way.  Returns a tree for the size
 389      in bytes.  A frontend can call lhd_expr_size to get the default
 390      semantics in cases that it doesn't want to handle specially.  */
 391   tree (*expr_size) (tree);
 392
 393   /* Update lang specific fields after duplicating function body.  */
 394   void (*update_decl_after_saving) (tree, void *);
 395
 396   /* Pointers to machine-independent attribute tables, for front ends
 397      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 398      table of attributes specific to the language, a table of
 399      attributes common to two or more languages (to allow easy
 400      sharing), and a table of attributes for checking formats.  */
 401   const struct attribute_spec *attribute_table;
 402   const struct attribute_spec *common_attribute_table;
 403   const struct attribute_spec *format_attribute_table;
 404
 405   /* Function-related language hooks.  */
 406   struct lang_hooks_for_functions function;
 407
 408   struct lang_hooks_for_tree_inlining tree_inlining;
 409
 410   struct lang_hooks_for_callgraph callgraph;
 411
 412   struct lang_hooks_for_tree_dump tree_dump;
 413
 414   struct lang_hooks_for_decls decls;
 415
 416   struct lang_hooks_for_types types;
 417
 418   /* Perform language-specific gimplification on the argument.  Returns an
 419      enum gimplify_status, though we can't see that type here.  */
 420   int (*gimplify_expr) (tree *, tree *, tree *);
 421
 422   /* True if the front end has gimplified the function before running the
 423      inliner, false if the front end generates GENERIC directly.  */
 424   bool gimple_before_inlining;
 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
 433 #endif /* GCC_LANG_HOOKS_H */