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