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 (*tree_chain_matters_p) (tree);
  43   int (*auto_var_in_fn_p) (tree, tree);
  44   tree (*copy_res_decl_for_inlining) (tree, tree, tree,
  45                                       void *, int *, tree);
  46   int (*anon_aggr_type_p) (tree);
  47   bool (*var_mod_type_p) (tree);
  48   int (*start_inlining) (tree);
  49   void (*end_inlining) (tree);
  50   tree (*convert_parm_for_inlining) (tree, tree, tree, int);
  51   int (*estimate_num_insns) (tree);
  52 };
  53
  54 struct lang_hooks_for_callgraph
  55 {
  56   /* The node passed is a language-specific tree node.  If its contents
  57      are relevant to use of other declarations, mark them.  */
  58   tree (*analyze_expr) (tree *, int *, tree);
  59
  60   /* Produce RTL for function passed as argument.  */
  61   void (*expand_function) (tree);
  62 };
  63
  64 /* Lang hooks for management of language-specific data or status
  65    when entering / leaving functions etc.  */
  66 struct lang_hooks_for_functions
  67 {
  68   /* Called when entering a function.  */
  69   void (*init) (struct function *);
  70
  71   /* Called when leaving a function.  */
  72   void (*final) (struct function *);
  73
  74   /* Called when entering a nested function.  */
  75   void (*enter_nested) (struct function *);
  76
  77   /* Called when leaving a nested function.  */
  78   void (*leave_nested) (struct function *);
  79 };
  80
  81 /* Lang hooks for rtl code generation.  */
  82 struct lang_hooks_for_rtl_expansion
  83 {
  84   /* Called after expand_function_start, but before expanding the body.  */
  85   void (*start) (void);
  86
  87   /* Called to expand each statement.  */
  88   void (*stmt) (tree);
  89
  90   /* Called after expanding the body but before expand_function_end.  */
  91   void (*end) (void);
  92 };
  93
  94 /* The following hooks are used by tree-dump.c.  */
  95
  96 struct lang_hooks_for_tree_dump
  97 {
  98   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  99      does not want the usual dumping of the second argument.  */
 100   bool (*dump_tree) (void *, tree);
 101
 102   /* Determine type qualifiers in a language-specific way.  */
 103   int (*type_quals) (tree);
 104 };
 105
 106 /* Hooks related to types.  */
 107
 108 struct lang_hooks_for_types
 109 {
 110   /* Return a new type (with the indicated CODE), doing whatever
 111      language-specific processing is required.  */
 112   tree (*make_type) (enum tree_code);
 113
 114   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
 115      mode.  */
 116   tree (*type_for_mode) (enum machine_mode, int);
 117
 118   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
 119      integer type with at least that precision.  */
 120   tree (*type_for_size) (unsigned, int);
 121
 122   /* Given an integer type T, return a type like T but unsigned.
 123      If T is unsigned, the value is T.  */
 124   tree (*unsigned_type) (tree);
 125
 126   /* Given an integer type T, return a type like T but signed.
 127      If T is signed, the value is T.  */
 128   tree (*signed_type) (tree);
 129
 130   /* Return a type the same as TYPE except unsigned or signed
 131      according to UNSIGNEDP.  */
 132   tree (*signed_or_unsigned_type) (int, tree);
 133
 134   /* Given a type, apply default promotions to unnamed function
 135      arguments and return the new type.  Return the same type if no
 136      change.  Required by any language that supports variadic
 137      arguments.  The default hook aborts.  */
 138   tree (*type_promotes_to) (tree);
 139
 140   /* Register TYPE as a builtin type with the indicated NAME.  The
 141      TYPE is placed in the outermost lexical scope.  The semantics
 142      should be analogous to:
 143
 144        typedef TYPE NAME;
 145
 146      in C.  The default hook ignores the declaration.  */
 147   void (*register_builtin_type) (tree, const char *);
 148
 149   /* This routine is called in tree.c to print an error message for
 150      invalid use of an incomplete type.  VALUE is the expression that
 151      was used (or 0 if that isn't known) and TYPE is the type that was
 152      invalid.  */
 153   void (*incomplete_type_error) (tree value, tree type);
 154
 155   /* Nonzero if types that are identical are to be hashed so that only
 156      one copy is kept.  If a language requires unique types for each
 157      user-specified type, such as Ada, this should be set to TRUE.  */
 158   bool hash_types;
 159 };
 160
 161 /* Language hooks related to decls and the symbol table.  */
 162
 163 struct lang_hooks_for_decls
 164 {
 165   /* Enter a new lexical scope.  Argument is always zero when called
 166      from outside the front end.  */
 167   void (*pushlevel) (int);
 168
 169   /* Exit a lexical scope and return a BINDING for that scope.
 170      Takes three arguments:
 171      KEEP -- nonzero if there were declarations in this scope.
 172      REVERSE -- reverse the order of decls before returning them.
 173      FUNCTIONBODY -- nonzero if this level is the body of a function.  */
 174   tree (*poplevel) (int, int, int);
 175
 176   /* Returns nonzero if we are in the global binding level.  Ada
 177      returns -1 for an undocumented reason used in stor-layout.c.  */
 178   int (*global_bindings_p) (void);
 179
 180   /* Insert BLOCK at the end of the list of subblocks of the
 181      current binding level.  This is used when a BIND_EXPR is expanded,
 182      to handle the BLOCK node inside the BIND_EXPR.  */
 183   void (*insert_block) (tree);
 184
 185   /* Set the BLOCK node for the current scope level.  */
 186   void (*set_block) (tree);
 187
 188   /* Function to add a decl to the current scope level.  Takes one
 189      argument, a decl to add.  Returns that decl, or, if the same
 190      symbol is already declared, may return a different decl for that
 191      name.  */
 192   tree (*pushdecl) (tree);
 193
 194   /* Returns the chain of decls so far in the current scope level.  */
 195   tree (*getdecls) (void);
 196
 197   /* Returns true when we should warn for an unused global DECL.
 198      We will already have checked that it has static binding.  */
 199   bool (*warn_unused_global) (tree);
 200
 201   /* Obtain a list of globals and do final output on them at end
 202      of compilation */
 203   void (*final_write_globals) (void);
 204
 205   /* Do necessary preparations before assemble_variable can proceed.  */
 206   void (*prepare_assemble_variable) (tree);
 207
 208   /* True if this decl may be called via a sibcall.  */
 209   bool (*ok_for_sibcall) (tree);
 210 };
 211
 212 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 213
 214 struct lang_hooks
 215 {
 216   /* String identifying the front end.  e.g. "GNU C++".  */
 217   const char *name;
 218
 219   /* sizeof (struct lang_identifier), so make_node () creates
 220      identifier nodes long enough for the language-specific slots.  */
 221   size_t identifier_size;
 222
 223   /* Determines the size of any language-specific 'x' or 'c' nodes.
 224      Since it is called from make_node, the only information available
 225      is the tree code.  Expected to abort on unrecognized codes.  */
 226   size_t (*tree_size) (enum tree_code);
 227
 228   /* The first callback made to the front end, for simple
 229      initialization needed before any calls to handle_option.  Return
 230      the language mask to filter the switch array with.  */
 231   unsigned int (*init_options) (unsigned int argc, const char **argv);
 232
 233   /* Callback used to perform language-specific initialization for the
 234      global diagnostic context structure.  */
 235   void (*initialize_diagnostics) (struct diagnostic_context *);
 236
 237   /* Handle the switch CODE, which has real type enum opt_code from
 238      options.h.  If the switch takes an argument, it is passed in ARG
 239      which points to permanent storage.  The handler is responsible for
 240      checking whether ARG is NULL, which indicates that no argument
 241      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 242      for the positive and negative forms respectively.
 243
 244      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 245      valid and should not be treated as language-independent too.  */
 246   int (*handle_option) (size_t code, const char *arg, int value);
 247
 248   /* Return false to use the default complaint about a missing
 249      argument, otherwise output a complaint and return true.  */
 250   bool (*missing_argument) (const char *opt, size_t code);
 251
 252   /* Called when all command line options have been parsed to allow
 253      further processing and initialization
 254
 255      Should return true to indicate that a compiler back-end is
 256      not required, such as with the -E option.
 257
 258      If errorcount is nonzero after this call the compiler exits
 259      immediately and the finish hook is not called.  */
 260   bool (*post_options) (const char **);
 261
 262   /* Called after post_options to initialize the front end.  Return
 263      false to indicate that no further compilation be performed, in
 264      which case the finish hook is called immediately.  */
 265   bool (*init) (void);
 266
 267   /* Called at the end of compilation, as a finalizer.  */
 268   void (*finish) (void);
 269
 270   /* Parses the entire file.  The argument is nonzero to cause bison
 271      parsers to dump debugging information during parsing.  */
 272   void (*parse_file) (int);
 273
 274   /* Called immediately after parsing to clear the binding stack.  */
 275   void (*clear_binding_stack) (void);
 276
 277   /* Called to obtain the alias set to be used for an expression or type.
 278      Returns -1 if the language does nothing special for it.  */
 279   HOST_WIDE_INT (*get_alias_set) (tree);
 280
 281   /* Called with an expression that is to be processed as a constant.
 282      Returns either the same expression or a language-independent
 283      constant equivalent to its input.  */
 284   tree (*expand_constant) (tree);
 285
 286   /* Called by expand_expr for language-specific tree codes.
 287      Fourth argument is actually an enum expand_modifier.  */
 288   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 289
 290   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 291      operation.
 292
 293      This preparation consists of taking the ordinary representation
 294      of an expression expr and producing a valid tree boolean
 295      expression describing whether expr is nonzero.  We could simply
 296      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 297      but we optimize comparisons, &&, ||, and !.
 298
 299      The result should be an expression of boolean type (if not an
 300      error_mark_node).  */
 301   tree (*truthvalue_conversion) (tree);
 302
 303   /* Hook called by safe_from_p for language-specific tree codes.  It is
 304      up to the language front-end to install a hook if it has any such
 305      codes that safe_from_p needs to know about.  Since same_from_p will
 306      recursively explore the TREE_OPERANDs of an expression, this hook
 307      should not reexamine those pieces.  This routine may recursively
 308      call safe_from_p; it should always pass `0' as the TOP_P
 309      parameter.  */
 310   int (*safe_from_p) (rtx, tree);
 311
 312   /* Function to finish handling an incomplete decl at the end of
 313      compilation.  Default hook is does nothing.  */
 314   void (*finish_incomplete_decl) (tree);
 315
 316   /* Function used by unsafe_for_reeval.  A non-negative number is
 317      returned directly from unsafe_for_reeval, a negative number falls
 318      through.  The default hook returns a negative number.  */
 319   int (*unsafe_for_reeval) (tree);
 320
 321   /* Mark EXP saying that we need to be able to take the address of
 322      it; it should not be allocated in a register.  Return true if
 323      successful.  */
 324   bool (*mark_addressable) (tree);
 325
 326   /* Hook called by staticp for language-specific tree codes.  */
 327   int (*staticp) (tree);
 328
 329   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 330      DECL_NODE with a newly GC-allocated copy.  */
 331   void (*dup_lang_specific_decl) (tree);
 332
 333   /* Called before its argument, an UNSAVE_EXPR, is to be
 334      unsaved.  Modify it in-place so that all the evaluate only once
 335      things are cleared out.  */
 336   tree (*unsave_expr_now) (tree);
 337
 338   /* Called by expand_expr to build and return the cleanup-expression
 339      for the passed TARGET_EXPR.  Return NULL if there is none.  */
 340   tree (*maybe_build_cleanup) (tree);
 341
 342   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 343      thing that the assembler should talk about, set
 344      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 345      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 346      assembler does not talk about it.  */
 347   void (*set_decl_assembler_name) (tree);
 348
 349   /* Return nonzero if fold-const is free to use bit-field
 350      optimizations, for instance in fold_truthop().  */
 351   bool (*can_use_bit_fields_p) (void);
 352
 353   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
 354   bool honor_readonly;
 355
 356   /* Nonzero if this front end does not generate a dummy BLOCK between
 357      the outermost scope of the function and the FUNCTION_DECL.  See
 358      is_body_block in stmt.c, and its callers.  */
 359   bool no_body_blocks;
 360
 361   /* The front end can add its own statistics to -fmem-report with
 362      this hook.  It should output to stderr.  */
 363   void (*print_statistics) (void);
 364
 365   /* Called by print_tree when there is a tree of class 'x' that it
 366      doesn't know how to display.  */
 367   lang_print_tree_hook print_xnode;
 368
 369   /* Called to print language-dependent parts of a class 'd', class
 370      't', and IDENTIFIER_NODE nodes.  */
 371   lang_print_tree_hook print_decl;
 372   lang_print_tree_hook print_type;
 373   lang_print_tree_hook print_identifier;
 374
 375   /* Computes the name to use to print a declaration.  DECL is the
 376      non-NULL declaration in question.  VERBOSITY determines what
 377      information will be printed: 0: DECL_NAME, demangled as
 378      necessary.  1: and scope information.  2: and any other
 379      information that might be interesting, such as function parameter
 380      types in C++.  */
 381   const char *(*decl_printable_name) (tree decl, int verbosity);
 382
 383   /* Given a CALL_EXPR, return a function decl that is its target.  */
 384   tree (*lang_get_callee_fndecl) (tree);
 385
 386   /* Called by report_error_function to print out function name.  */
 387   void (*print_error_function) (struct diagnostic_context *, const char *);
 388
 389   /* Called from expr_size to calculate the size of the value of an
 390      expression in a language-dependent way.  Returns a tree for the size
 391      in bytes.  A frontend can call lhd_expr_size to get the default
 392      semantics in cases that it doesn't want to handle specially.  */
 393   tree (*expr_size) (tree);
 394
 395   /* Called from uninitialized_vars_warning to find out if a variable is
 396      uninitialized based on DECL_INITIAL.  */
 397   bool (*decl_uninit) (tree);
 398
 399   /* Update lang specific fields after duplicating function body.  */
 400   void (*update_decl_after_saving) (tree, void *);
 401
 402   /* Pointers to machine-independent attribute tables, for front ends
 403      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 404      table of attributes specific to the language, a table of
 405      attributes common to two or more languages (to allow easy
 406      sharing), and a table of attributes for checking formats.  */
 407   const struct attribute_spec *attribute_table;
 408   const struct attribute_spec *common_attribute_table;
 409   const struct attribute_spec *format_attribute_table;
 410
 411   /* Function-related language hooks.  */
 412   struct lang_hooks_for_functions function;
 413
 414   struct lang_hooks_for_tree_inlining tree_inlining;
 415
 416   struct lang_hooks_for_callgraph callgraph;
 417
 418   struct lang_hooks_for_tree_dump tree_dump;
 419
 420   struct lang_hooks_for_decls decls;
 421
 422   struct lang_hooks_for_types types;
 423
 424   struct lang_hooks_for_rtl_expansion rtl_expand;
 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 */