gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright 2001, 2002 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC 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 GNU CC 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 GNU CC; 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) PARAMS ((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   union tree_node *(*walk_subtrees) PARAMS ((union tree_node **, int *,
  37                                              union tree_node *(*)
  38                                              (union tree_node **,
  39                                               int *, void *),
  40                                              void *, void *));
  41   int (*cannot_inline_tree_fn) PARAMS ((union tree_node **));
  42   int (*disregard_inline_limits) PARAMS ((union tree_node *));
  43   union tree_node *(*add_pending_fn_decls) PARAMS ((void *,
  44                                                     union tree_node *));
  45   int (*tree_chain_matters_p) PARAMS ((union tree_node *));
  46   int (*auto_var_in_fn_p) PARAMS ((union tree_node *, union tree_node *));
  47   union tree_node *(*copy_res_decl_for_inlining) PARAMS ((union tree_node *,
  48                                                           union tree_node *,
  49                                                           union tree_node *,
  50                                                           void *, int *,
  51                                                           tree));
  52   int (*anon_aggr_type_p) PARAMS ((union tree_node *));
  53   bool (*var_mod_type_p) PARAMS ((union tree_node *));
  54   int (*start_inlining) PARAMS ((union tree_node *));
  55   void (*end_inlining) PARAMS ((union tree_node *));
  56   union tree_node *(*convert_parm_for_inlining) PARAMS ((union tree_node *,
  57                                                          union tree_node *,
  58                                                          union tree_node *));
  59 };
  60
  61 struct lang_hooks_for_callgraph
  62 {
  63   /* Function passed as argument is needed and will be compiled.
  64      Lower the representation so the calls are explicit.  */
  65   void (*lower_function) PARAMS ((union tree_node *));
  66   /* Produce RTL for function passed as argument.  */
  67   void (*expand_function) PARAMS ((union tree_node *));
  68 };
  69
  70 /* Lang hooks for management of language-specific data or status
  71    when entering / leaving functions etc.  */
  72 struct lang_hooks_for_functions
  73 {
  74   /* Called when entering a function.  */
  75   void (*init) PARAMS ((struct function *));
  76
  77   /* Called when leaving a function.  */
  78   void (*final) PARAMS ((struct function *));
  79
  80   /* Called when entering a nested function.  */
  81   void (*enter_nested) PARAMS ((struct function *));
  82
  83   /* Called when leaving a nested function.  */
  84   void (*leave_nested) PARAMS ((struct function *));
  85 };
  86
  87 /* The following hooks are used by tree-dump.c.  */
  88
  89 struct lang_hooks_for_tree_dump
  90 {
  91   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  92      does not want the usual dumping of the second argument.  */
  93   int (*dump_tree) PARAMS ((void *, tree));
  94
  95   /* Determine type qualifiers in a language-specific way.  */
  96   int (*type_quals) PARAMS ((tree));
  97 };
  98
  99 /* Hooks related to types.  */
 100
 101 struct lang_hooks_for_types
 102 {
 103   /* Return a new type (with the indicated CODE), doing whatever
 104      language-specific processing is required.  */
 105   tree (*make_type) PARAMS ((enum tree_code));
 106
 107   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
 108      mode.  */
 109   tree (*type_for_mode) PARAMS ((enum machine_mode, int));
 110
 111   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
 112      integer type with at least that precision.  */
 113   tree (*type_for_size) PARAMS ((unsigned, int));
 114
 115   /* Given an integer type T, return a type like T but unsigned.
 116      If T is unsigned, the value is T.  */
 117   tree (*unsigned_type) PARAMS ((tree));
 118
 119   /* Given an integer type T, return a type like T but signed.
 120      If T is signed, the value is T.  */
 121   tree (*signed_type) PARAMS ((tree));
 122
 123   /* Return a type the same as TYPE except unsigned or signed
 124      according to UNSIGNEDP.  */
 125   tree (*signed_or_unsigned_type) PARAMS ((int, tree));
 126
 127   /* Given a type, apply default promotions to unnamed function
 128      arguments and return the new type.  Return the same type if no
 129      change.  Required by any language that supports variadic
 130      arguments.  The default hook aborts.  */
 131   tree (*type_promotes_to) PARAMS ((tree));
 132
 133   /* This routine is called in tree.c to print an error message for
 134      invalid use of an incomplete type.  VALUE is the expression that
 135      was used (or 0 if that isn't known) and TYPE is the type that was
 136      invalid.  */
 137   void (*incomplete_type_error) PARAMS ((tree value, tree type));
 138 };
 139
 140 /* Language hooks related to decls and the symbol table.  */
 141
 142 struct lang_hooks_for_decls
 143 {
 144   /* Enter a new lexical scope.  Argument is always zero when called
 145      from outside the front end.  */
 146   void (*pushlevel) PARAMS ((int));
 147
 148   /* Exit a lexical scope and return a BINDING for that scope.
 149      Takes three arguments:
 150      KEEP -- nonzero if there were declarations in this scope.
 151      REVERSE -- reverse the order of decls before returning them.
 152      FUNCTIONBODY -- nonzero if this level is the body of a function.  */
 153   tree (*poplevel) PARAMS ((int, int, int));
 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) PARAMS ((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) PARAMS ((tree));
 163
 164   /* Set the BLOCK node for the current scope level.  */
 165   void (*set_block) PARAMS ((tree));
 166
 167   /* Function to add a decl to the current scope level.  Takes one
 168      argument, a decl to add.  Returns that decl, or, if the same
 169      symbol is already declared, may return a different decl for that
 170      name.  */
 171   tree (*pushdecl) PARAMS ((tree));
 172
 173   /* Returns the chain of decls so far in the current scope level.  */
 174   tree (*getdecls) PARAMS ((void));
 175
 176   /* Returns true when we should warn for an unused global DECL.
 177      We will already have checked that it has static binding.  */
 178   bool (*warn_unused_global) PARAMS ((tree));
 179
 180   /* Obtain a list of globals and do final output on them at end
 181      of compilation */
 182   void (*final_write_globals) PARAMS ((void));
 183 };
 184
 185 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 186
 187 struct lang_hooks
 188 {
 189   /* String identifying the front end.  e.g. "GNU C++".  */
 190   const char *name;
 191
 192   /* sizeof (struct lang_identifier), so make_node () creates
 193      identifier nodes long enough for the language-specific slots.  */
 194   size_t identifier_size;
 195
 196   /* The first callback made to the front end, for simple
 197      initialization needed before any calls to decode_option.  */
 198   void (*init_options) PARAMS ((void));
 199
 200   /* Function called with an option vector as argument, to decode a
 201      single option (typically starting with -f or -W or +).  It should
 202      return the number of command-line arguments it uses if it handles
 203      the option, or 0 and not complain if it does not recognize the
 204      option.  If this function returns a negative number, then its
 205      absolute value is the number of command-line arguments used, but,
 206      in addition, no language-independent option processing should be
 207      done for this option.  */
 208   int (*decode_option) PARAMS ((int, char **));
 209
 210   /* Called when all command line options have been parsed to allow
 211      further processing and initialization
 212
 213      Should return true to indicate that a compiler back-end is
 214      not required, such as with the -E option.
 215
 216      If errorcount is nonzero after this call the compiler exits
 217      immediately and the finish hook is not called.  */
 218   bool (*post_options) PARAMS ((const char **));
 219
 220   /* Called after post_options to initialize the front end.  Return
 221      false to indicate that no further compilation be performed, in
 222      which case the finish hook is called immediately.  */
 223   bool (*init) PARAMS ((void));
 224
 225   /* Called at the end of compilation, as a finalizer.  */
 226   void (*finish) PARAMS ((void));
 227
 228   /* Parses the entire file.  The argument is nonzero to cause bison
 229      parsers to dump debugging information during parsing.  */
 230   void (*parse_file) PARAMS ((int));
 231
 232   /* Called immediately after parsing to clear the binding stack.  */
 233   void (*clear_binding_stack) PARAMS ((void));
 234
 235   /* Called to obtain the alias set to be used for an expression or type.
 236      Returns -1 if the language does nothing special for it.  */
 237   HOST_WIDE_INT (*get_alias_set) PARAMS ((tree));
 238
 239   /* Called with an expression that is to be processed as a constant.
 240      Returns either the same expression or a language-independent
 241      constant equivalent to its input.  */
 242   tree (*expand_constant) PARAMS ((tree));
 243
 244   /* Called by expand_expr for language-specific tree codes.
 245      Fourth argument is actually an enum expand_modifier.  */
 246   rtx (*expand_expr) PARAMS ((tree, rtx, enum machine_mode, int));
 247
 248   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 249      operation.
 250
 251      This preparation consists of taking the ordinary representation
 252      of an expression expr and producing a valid tree boolean
 253      expression describing whether expr is nonzero.  We could simply
 254      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 255      but we optimize comparisons, &&, ||, and !.
 256
 257      The result should be an expression of boolean type (if not an
 258      error_mark_node).  */
 259   tree (*truthvalue_conversion) PARAMS ((tree));
 260
 261   /* Possibly apply default attributes to a function (represented by
 262      a FUNCTION_DECL).  */
 263   void (*insert_default_attributes) PARAMS ((tree));
 264
 265   /* Hook called by safe_from_p for language-specific tree codes.  It is
 266      up to the language front-end to install a hook if it has any such
 267      codes that safe_from_p needs to know about.  Since same_from_p will
 268      recursively explore the TREE_OPERANDs of an expression, this hook
 269      should not reexamine those pieces.  This routine may recursively
 270      call safe_from_p; it should always pass `0' as the TOP_P
 271      parameter.  */
 272   int (*safe_from_p) PARAMS ((rtx, tree));
 273
 274   /* Function to finish handling an incomplete decl at the end of
 275      compilation.  Default hook is does nothing.  */
 276   void (*finish_incomplete_decl) PARAMS ((tree));
 277
 278   /* Function used by unsafe_for_reeval.  A non-negative number is
 279      returned directly from unsafe_for_reeval, a negative number falls
 280      through.  The default hook returns a negative number.  */
 281   int (*unsafe_for_reeval) PARAMS ((tree));
 282
 283   /* Mark EXP saying that we need to be able to take the address of
 284      it; it should not be allocated in a register.  Return true if
 285      successful.  */
 286   bool (*mark_addressable) PARAMS ((tree));
 287
 288   /* Hook called by staticp for language-specific tree codes.  */
 289   int (*staticp) PARAMS ((tree));
 290
 291   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 292      DECL_NODE with a newly GC-allocated copy.  */
 293   void (*dup_lang_specific_decl) PARAMS ((tree));
 294
 295   /* Called before its argument, an UNSAVE_EXPR, is to be
 296      unsaved.  Modify it in-place so that all the evaluate only once
 297      things are cleared out.  */
 298   tree (*unsave_expr_now) PARAMS ((tree));
 299
 300   /* Called by expand_expr to build and return the cleanup-expression
 301      for the passed TARGET_EXPR.  Return NULL if there is none.  */
 302   tree (*maybe_build_cleanup) PARAMS ((tree));
 303
 304   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 305      thing that the assembler should talk about, set
 306      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 307      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 308      assembler does not talk about it.  */
 309   void (*set_decl_assembler_name) PARAMS ((tree));
 310
 311   /* Return nonzero if fold-const is free to use bit-field
 312      optimizations, for instance in fold_truthop().  */
 313   bool (*can_use_bit_fields_p) PARAMS ((void));
 314
 315   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
 316   bool honor_readonly;
 317
 318   /* The front end can add its own statistics to -fmem-report with
 319      this hook.  It should output to stderr.  */
 320   void (*print_statistics) PARAMS ((void));
 321
 322   /* Called by print_tree when there is a tree of class 'x' that it
 323      doesn't know how to display.  */
 324   lang_print_tree_hook print_xnode;
 325
 326   /* Called to print language-dependent parts of a class 'd', class
 327      't', and IDENTIFIER_NODE nodes.  */
 328   lang_print_tree_hook print_decl;
 329   lang_print_tree_hook print_type;
 330   lang_print_tree_hook print_identifier;
 331
 332   /* Computes the name to use to print a declaration.  DECL is the
 333      non-NULL declaration in question.  VERBOSITY determines what
 334      information will be printed: 0: DECL_NAME, demangled as
 335      necessary.  1: and scope information.  2: and any other
 336      information that might be interesting, such as function parameter
 337      types in C++.  */
 338   const char *(*decl_printable_name) PARAMS ((tree decl, int verbosity));
 339
 340   /* Called by report_error_function to print out function name.  */
 341   void (*print_error_function) PARAMS ((struct diagnostic_context *,
 342                                         const char *));
 343
 344   /* Called from expr_size to calculate the size of the value of an
 345      expression in a language-dependent way.  Returns a tree for the size
 346      in bytes.  A frontend can call lhd_expr_size to get the default
 347      semantics in cases that it doesn't want to handle specially.  */
 348   tree (*expr_size) PARAMS ((tree));
 349
 350   /* Pointers to machine-independent attribute tables, for front ends
 351      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 352      table of attributes specific to the language, a table of
 353      attributes common to two or more languages (to allow easy
 354      sharing), and a table of attributes for checking formats.  */
 355   const struct attribute_spec *attribute_table;
 356   const struct attribute_spec *common_attribute_table;
 357   const struct attribute_spec *format_attribute_table;
 358
 359   /* Function-related language hooks.  */
 360   struct lang_hooks_for_functions function;
 361
 362   struct lang_hooks_for_tree_inlining tree_inlining;
 363
 364   struct lang_hooks_for_callgraph callgraph;
 365
 366   struct lang_hooks_for_tree_dump tree_dump;
 367
 368   struct lang_hooks_for_decls decls;
 369
 370   struct lang_hooks_for_types types;
 371
 372   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 373      and langhooks.c accordingly.  */
 374 };
 375
 376 /* Each front end provides its own.  */
 377 extern const struct lang_hooks lang_hooks;
 378
 379 #endif /* GCC_LANG_HOOKS_H */