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   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 aborts.  */
 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
 188 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 189
 190 struct lang_hooks
 191 {
 192   /* String identifying the front end.  e.g. "GNU C++".  */
 193   const char *name;
 194
 195   /* sizeof (struct lang_identifier), so make_node () creates
 196      identifier nodes long enough for the language-specific slots.  */
 197   size_t identifier_size;
 198
 199   /* Determines the size of any language-specific 'x' or 'c' nodes.
 200      Since it is called from make_node, the only information available
 201      is the tree code.  Expected to abort on unrecognized codes.  */
 202   size_t (*tree_size) (enum tree_code);
 203
 204   /* The first callback made to the front end, for simple
 205      initialization needed before any calls to handle_option.  Return
 206      the language mask to filter the switch array with.  */
 207   unsigned int (*init_options) (unsigned int argc, const char **argv);
 208
 209   /* Callback used to perform language-specific initialization for the
 210      global diagnostic context structure.  */
 211   void (*initialize_diagnostics) (struct diagnostic_context *);
 212
 213   /* Handle the switch CODE, which has real type enum opt_code from
 214      options.h.  If the switch takes an argument, it is passed in ARG
 215      which points to permanent storage.  The handler is responsible for
 216      checking whether ARG is NULL, which indicates that no argument
 217      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 218      for the positive and negative forms respectively.
 219
 220      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 221      valid and should not be treated as language-independent too.  */
 222   int (*handle_option) (size_t code, const char *arg, int value);
 223
 224   /* Return false to use the default complaint about a missing
 225      argument, otherwise output a complaint and return true.  */
 226   bool (*missing_argument) (const char *opt, size_t code);
 227
 228   /* Called when all command line options have been parsed to allow
 229      further processing and initialization
 230
 231      Should return true to indicate that a compiler back-end is
 232      not required, such as with the -E option.
 233
 234      If errorcount is nonzero after this call the compiler exits
 235      immediately and the finish hook is not called.  */
 236   bool (*post_options) (const char **);
 237
 238   /* Called after post_options to initialize the front end.  Return
 239      false to indicate that no further compilation be performed, in
 240      which case the finish hook is called immediately.  */
 241   bool (*init) (void);
 242
 243   /* Called at the end of compilation, as a finalizer.  */
 244   void (*finish) (void);
 245
 246   /* Parses the entire file.  The argument is nonzero to cause bison
 247      parsers to dump debugging information during parsing.  */
 248   void (*parse_file) (int);
 249
 250   /* Called immediately after parsing to clear the binding stack.  */
 251   void (*clear_binding_stack) (void);
 252
 253   /* Called to obtain the alias set to be used for an expression or type.
 254      Returns -1 if the language does nothing special for it.  */
 255   HOST_WIDE_INT (*get_alias_set) (tree);
 256
 257   /* Called with an expression that is to be processed as a constant.
 258      Returns either the same expression or a language-independent
 259      constant equivalent to its input.  */
 260   tree (*expand_constant) (tree);
 261
 262   /* Called by expand_expr for language-specific tree codes.
 263      Fourth argument is actually an enum expand_modifier.  */
 264   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 265
 266   /* Called by expand_expr to generate the definition of a decl.  Returns
 267      1 if handled, 0 otherwise.  */
 268   int (*expand_decl) (tree);
 269
 270   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 271      operation.
 272
 273      This preparation consists of taking the ordinary representation
 274      of an expression expr and producing a valid tree boolean
 275      expression describing whether expr is nonzero.  We could simply
 276      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 277      but we optimize comparisons, &&, ||, and !.
 278
 279      The result should be an expression of boolean type (if not an
 280      error_mark_node).  */
 281   tree (*truthvalue_conversion) (tree);
 282
 283   /* Hook called by safe_from_p for language-specific tree codes.  It is
 284      up to the language front-end to install a hook if it has any such
 285      codes that safe_from_p needs to know about.  Since same_from_p will
 286      recursively explore the TREE_OPERANDs of an expression, this hook
 287      should not reexamine those pieces.  This routine may recursively
 288      call safe_from_p; it should always pass `0' as the TOP_P
 289      parameter.  */
 290   int (*safe_from_p) (rtx, tree);
 291
 292   /* Function to finish handling an incomplete decl at the end of
 293      compilation.  Default hook is does nothing.  */
 294   void (*finish_incomplete_decl) (tree);
 295
 296   /* Mark EXP saying that we need to be able to take the address of
 297      it; it should not be allocated in a register.  Return true if
 298      successful.  */
 299   bool (*mark_addressable) (tree);
 300
 301   /* Hook called by staticp for language-specific tree codes.  */
 302   bool (*staticp) (tree);
 303
 304   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 305      DECL_NODE with a newly GC-allocated copy.  */
 306   void (*dup_lang_specific_decl) (tree);
 307
 308   /* Reset argument so that it can be expanded again.
 309      Modify it in-place so that all the evaluate only once
 310      things are cleared out.  */
 311   tree (*unsave_expr_now) (tree);
 312
 313   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 314      thing that the assembler should talk about, set
 315      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 316      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 317      assembler does not talk about it.  */
 318   void (*set_decl_assembler_name) (tree);
 319
 320   /* Return nonzero if fold-const is free to use bit-field
 321      optimizations, for instance in fold_truthop().  */
 322   bool (*can_use_bit_fields_p) (void);
 323
 324   /* Nonzero if operations on types narrower than their mode should
 325      have their results reduced to the precision of the type.  */
 326   bool reduce_bit_field_operations;
 327
 328   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
 329   bool honor_readonly;
 330
 331   /* Nonzero if this front end does not generate a dummy BLOCK between
 332      the outermost scope of the function and the FUNCTION_DECL.  See
 333      is_body_block in stmt.c, and its callers.  */
 334   bool no_body_blocks;
 335
 336   /* The front end can add its own statistics to -fmem-report with
 337      this hook.  It should output to stderr.  */
 338   void (*print_statistics) (void);
 339
 340   /* Called by print_tree when there is a tree of class 'x' that it
 341      doesn't know how to display.  */
 342   lang_print_tree_hook print_xnode;
 343
 344   /* Called to print language-dependent parts of a class 'd', class
 345      't', and IDENTIFIER_NODE nodes.  */
 346   lang_print_tree_hook print_decl;
 347   lang_print_tree_hook print_type;
 348   lang_print_tree_hook print_identifier;
 349
 350   /* Computes the name to use to print a declaration.  DECL is the
 351      non-NULL declaration in question.  VERBOSITY determines what
 352      information will be printed: 0: DECL_NAME, demangled as
 353      necessary.  1: and scope information.  2: and any other
 354      information that might be interesting, such as function parameter
 355      types in C++.  */
 356   const char *(*decl_printable_name) (tree decl, 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) (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) (tree);
 374
 375   /* Pointers to machine-independent attribute tables, for front ends
 376      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 377      table of attributes specific to the language, a table of
 378      attributes common to two or more languages (to allow easy
 379      sharing), and a table of attributes for checking formats.  */
 380   const struct attribute_spec *attribute_table;
 381   const struct attribute_spec *common_attribute_table;
 382   const struct attribute_spec *format_attribute_table;
 383
 384   /* Function-related language hooks.  */
 385   struct lang_hooks_for_functions function;
 386
 387   struct lang_hooks_for_tree_inlining tree_inlining;
 388
 389   struct lang_hooks_for_callgraph callgraph;
 390
 391   struct lang_hooks_for_tree_dump tree_dump;
 392
 393   struct lang_hooks_for_decls decls;
 394
 395   struct lang_hooks_for_types types;
 396
 397   /* Perform language-specific gimplification on the argument.  Returns an
 398      enum gimplify_status, though we can't see that type here.  */
 399   int (*gimplify_expr) (tree *, tree *, tree *);
 400
 401   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 402      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 403   tree (*fold_obj_type_ref) (tree, tree);
 404
 405   /* Return a definition for a builtin function named NAME and whose data type
 406      is TYPE.  TYPE should be a function type with argument types.
 407      FUNCTION_CODE tells later passes how to compile calls to this function.
 408      See tree.h for its possible values.
 409
 410      If LIBRARY_NAME is nonzero, use that for DECL_ASSEMBLER_NAME,
 411      the name to be called if we can't opencode the function.  If
 412      ATTRS is nonzero, use that for the function's attribute list.  */
 413   tree (*builtin_function) (const char *name, tree type, int function_code,
 414                             enum built_in_class class,
 415                             const char *library_name, tree attrs);
 416
 417   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 418      and langhooks.c accordingly.  */
 419 };
 420
 421 /* Each front end provides its own.  */
 422 extern const struct lang_hooks lang_hooks;
 423
 424 #endif /* GCC_LANG_HOOKS_H */