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                                                           void *));
  52   int (*anon_aggr_type_p) PARAMS ((union tree_node *));
  53   int (*start_inlining) PARAMS ((union tree_node *));
  54   void (*end_inlining) PARAMS ((union tree_node *));
  55   union tree_node *(*convert_parm_for_inlining) PARAMS ((union tree_node *,
  56                                                          union tree_node *,
  57                                                          union tree_node *));
  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) PARAMS ((struct function *));
  66
  67   /* Called when leaving a function.  */
  68   void (*final) PARAMS ((struct function *));
  69
  70   /* Called when entering a nested function.  */
  71   void (*enter_nested) PARAMS ((struct function *));
  72
  73   /* Called when leaving a nested function.  */
  74   void (*leave_nested) PARAMS ((struct function *));
  75 };
  76
  77 /* The following hooks are used by tree-dump.c.  */
  78
  79 struct lang_hooks_for_tree_dump
  80 {
  81   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  82      does not want the usual dumping of the second argument.  */
  83   int (*dump_tree) PARAMS ((void *, tree));
  84
  85   /* Determine type qualifiers in a language-specific way.  */
  86   int (*type_quals) PARAMS ((tree));
  87 };
  88
  89 /* Hooks related to types.  */
  90
  91 struct lang_hooks_for_types
  92 {
  93   /* Return a new type (with the indicated CODE), doing whatever
  94      language-specific processing is required.  */
  95   tree (*make_type) PARAMS ((enum tree_code));
  96
  97   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  98      mode.  */
  99   tree (*type_for_mode) PARAMS ((enum machine_mode, int));
 100
 101   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
 102      integer type with at least that precision.  */
 103   tree (*type_for_size) PARAMS ((unsigned, int));
 104
 105   /* Given an integer type T, return a type like T but unsigned.
 106      If T is unsigned, the value is T.  */
 107   tree (*unsigned_type) PARAMS ((tree));
 108
 109   /* Given an integer type T, return a type like T but signed.
 110      If T is signed, the value is T.  */
 111   tree (*signed_type) PARAMS ((tree));
 112
 113   /* Return a type the same as TYPE except unsigned or signed
 114      according to UNSIGNEDP.  */
 115   tree (*signed_or_unsigned_type) PARAMS ((int, tree));
 116
 117   /* Given a type, apply default promotions to unnamed function
 118      arguments and return the new type.  Return the same type if no
 119      change.  Required by any language that supports variadic
 120      arguments.  The default hook aborts.  */
 121   tree (*type_promotes_to) PARAMS ((tree));
 122
 123   /* This routine is called in tree.c to print an error message for
 124      invalid use of an incomplete type.  VALUE is the expression that
 125      was used (or 0 if that isn't known) and TYPE is the type that was
 126      invalid.  */
 127   void (*incomplete_type_error) PARAMS ((tree value, tree type));
 128 };
 129
 130 /* Language hooks related to decls and the symbol table.  */
 131
 132 struct lang_hooks_for_decls
 133 {
 134   /* Enter a new lexical scope.  Argument is always zero when called
 135      from outside the front end.  */
 136   void (*pushlevel) PARAMS ((int));
 137
 138   /* Exit a lexical scope and return a BINDING for that scope.
 139      Takes three arguments:
 140      KEEP -- nonzero if there were declarations in this scope.
 141      REVERSE -- reverse the order of decls before returning them.
 142      FUNCTIONBODY -- nonzero if this level is the body of a function.  */
 143   tree (*poplevel) PARAMS ((int, int, int));
 144
 145   /* Returns nonzero if we are in the global binding level.  Ada
 146      returns -1 for an undocumented reason used in stor-layout.c.  */
 147   int (*global_bindings_p) PARAMS ((void));
 148
 149   /* Insert BLOCK at the end of the list of subblocks of the
 150      current binding level.  This is used when a BIND_EXPR is expanded,
 151      to handle the BLOCK node inside the BIND_EXPR.  */
 152   void (*insert_block) PARAMS ((tree));
 153
 154   /* Set the BLOCK node for the current scope level.  */
 155   void (*set_block) PARAMS ((tree));
 156
 157   /* Function to add a decl to the current scope level.  Takes one
 158      argument, a decl to add.  Returns that decl, or, if the same
 159      symbol is already declared, may return a different decl for that
 160      name.  */
 161   tree (*pushdecl) PARAMS ((tree));
 162
 163   /* Returns the chain of decls so far in the current scope level.  */
 164   tree (*getdecls) PARAMS ((void));
 165
 166   /* Returns true when we should warn for an unused global DECL.
 167      We will already have checked that it has static binding.  */
 168   bool (*warn_unused_global) PARAMS ((tree));
 169 };
 170
 171 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 172
 173 struct lang_hooks
 174 {
 175   /* String identifying the front end.  e.g. "GNU C++".  */
 176   const char *name;
 177
 178   /* sizeof (struct lang_identifier), so make_node () creates
 179      identifier nodes long enough for the language-specific slots.  */
 180   size_t identifier_size;
 181
 182   /* The first callback made to the front end, for simple
 183      initialization needed before any calls to decode_option.  */
 184   void (*init_options) PARAMS ((void));
 185
 186   /* Function called with an option vector as argument, to decode a
 187      single option (typically starting with -f or -W or +).  It should
 188      return the number of command-line arguments it uses if it handles
 189      the option, or 0 and not complain if it does not recognize the
 190      option.  If this function returns a negative number, then its
 191      absolute value is the number of command-line arguments used, but,
 192      in addition, no language-independent option processing should be
 193      done for this option.  */
 194   int (*decode_option) PARAMS ((int, char **));
 195
 196   /* Called when all command line options have been parsed.  Should do
 197      any required consistency checks, modifications etc.  Complex
 198      initialization should be left to the "init" callback, since GC
 199      and the identifier hashes are set up between now and then.
 200
 201      Should return zero unless the compiler back-end does not need to
 202      be initialized, such as with the -E option.
 203
 204      If errorcount is nonzero after this call the compiler exits
 205      immediately and the finish hook is not called.  */
 206   bool (*post_options) PARAMS ((void));
 207
 208   /* Called after post_options, to initialize the front end.  The main
 209      input filename is passed, which may be NULL; the front end should
 210      return the original filename (e.g. foo.i -> foo.c).  Return NULL
 211      to indicate a serious error of some sort; in that case no
 212      compilation is performed, and the finish hook is called
 213      immediately.  */
 214   const char * (*init) PARAMS ((const char *));
 215
 216   /* Called at the end of compilation, as a finalizer.  */
 217   void (*finish) PARAMS ((void));
 218
 219   /* Parses the entire file.  The argument is nonzero to cause bison
 220      parsers to dump debugging information during parsing.  */
 221   void (*parse_file) PARAMS ((int));
 222
 223   /* Called immediately after parsing to clear the binding stack.  */
 224   void (*clear_binding_stack) PARAMS ((void));
 225
 226   /* Called to obtain the alias set to be used for an expression or type.
 227      Returns -1 if the language does nothing special for it.  */
 228   HOST_WIDE_INT (*get_alias_set) PARAMS ((tree));
 229
 230   /* Called with an expression that is to be processed as a constant.
 231      Returns either the same expression or a language-independent
 232      constant equivalent to its input.  */
 233   tree (*expand_constant) PARAMS ((tree));
 234
 235   /* Called by expand_expr for language-specific tree codes.
 236      Fourth argument is actually an enum expand_modifier.  */
 237   rtx (*expand_expr) PARAMS ((tree, rtx, enum machine_mode, int));
 238
 239   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 240      operation.
 241
 242      This preparation consists of taking the ordinary representation
 243      of an expression expr and producing a valid tree boolean
 244      expression describing whether expr is nonzero.  We could simply
 245      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 246      but we optimize comparisons, &&, ||, and !.
 247
 248      The result should be an expression of boolean type (if not an
 249      error_mark_node).  */
 250   tree (*truthvalue_conversion) PARAMS ((tree));
 251
 252   /* Possibly apply default attributes to a function (represented by
 253      a FUNCTION_DECL).  */
 254   void (*insert_default_attributes) PARAMS ((tree));
 255
 256   /* Hook called by safe_from_p for language-specific tree codes.  It is
 257      up to the language front-end to install a hook if it has any such
 258      codes that safe_from_p needs to know about.  Since same_from_p will
 259      recursively explore the TREE_OPERANDs of an expression, this hook
 260      should not reexamine those pieces.  This routine may recursively
 261      call safe_from_p; it should always pass `0' as the TOP_P
 262      parameter.  */
 263   int (*safe_from_p) PARAMS ((rtx, tree));
 264
 265   /* Function to finish handling an incomplete decl at the end of
 266      compilation.  Default hook is does nothing.  */
 267   void (*finish_incomplete_decl) PARAMS ((tree));
 268
 269   /* Function used by unsafe_for_reeval.  A non-negative number is
 270      returned directly from unsafe_for_reeval, a negative number falls
 271      through.  The default hook returns a negative number.  */
 272   int (*unsafe_for_reeval) PARAMS ((tree));
 273
 274   /* Mark EXP saying that we need to be able to take the address of
 275      it; it should not be allocated in a register.  Return true if
 276      successful.  */
 277   bool (*mark_addressable) PARAMS ((tree));
 278
 279   /* Hook called by staticp for language-specific tree codes.  */
 280   int (*staticp) PARAMS ((tree));
 281
 282   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 283      DECL_NODE with a newly GC-allocated copy.  */
 284   void (*dup_lang_specific_decl) PARAMS ((tree));
 285
 286   /* Called before its argument, an UNSAVE_EXPR, is to be
 287      unsaved.  Modify it in-place so that all the evaluate only once
 288      things are cleared out.  */
 289   tree (*unsave_expr_now) PARAMS ((tree));
 290
 291   /* Called by expand_expr to build and return the cleanup-expression
 292      for the passed TARGET_EXPR.  Return NULL if there is none.  */
 293   tree (*maybe_build_cleanup) PARAMS ((tree));
 294
 295   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 296      thing that the assembler should talk about, set
 297      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 298      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 299      assembler does not talk about it.  */
 300   void (*set_decl_assembler_name) PARAMS ((tree));
 301
 302   /* Return nonzero if fold-const is free to use bit-field
 303      optimizations, for instance in fold_truthop().  */
 304   bool (*can_use_bit_fields_p) PARAMS ((void));
 305
 306   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
 307   bool honor_readonly;
 308
 309   /* The front end can add its own statistics to -fmem-report with
 310      this hook.  It should output to stderr.  */
 311   void (*print_statistics) PARAMS ((void));
 312
 313   /* Called by print_tree when there is a tree of class 'x' that it
 314      doesn't know how to display.  */
 315   lang_print_tree_hook print_xnode;
 316
 317   /* Called to print language-dependent parts of a class 'd', class
 318      't', and IDENTIFIER_NODE nodes.  */
 319   lang_print_tree_hook print_decl;
 320   lang_print_tree_hook print_type;
 321   lang_print_tree_hook print_identifier;
 322
 323   /* Computes the name to use to print a declaration.  DECL is the
 324      non-NULL declaration in question.  VERBOSITY determines what
 325      information will be printed: 0: DECL_NAME, demangled as
 326      necessary.  1: and scope information.  2: and any other
 327      information that might be interesting, such as function parameter
 328      types in C++.  */
 329   const char *(*decl_printable_name) PARAMS ((tree decl, int verbosity));
 330
 331   /* Called by report_error_function to print out function name.  */
 332   void (*print_error_function) PARAMS ((struct diagnostic_context *,
 333                                         const char *));
 334
 335   /* Called from expr_size to calculate the size of the value of an
 336      expression in a language-dependent way.  Returns a tree for the size
 337      in bytes.  A frontend can call lhd_expr_size to get the default
 338      semantics in cases that it doesn't want to handle specially.  */
 339   tree (*expr_size) PARAMS ((tree));
 340
 341   /* Pointers to machine-independent attribute tables, for front ends
 342      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 343      table of attributes specific to the language, a table of
 344      attributes common to two or more languages (to allow easy
 345      sharing), and a table of attributes for checking formats.  */
 346   const struct attribute_spec *attribute_table;
 347   const struct attribute_spec *common_attribute_table;
 348   const struct attribute_spec *format_attribute_table;
 349
 350   /* Function-related language hooks.  */
 351   struct lang_hooks_for_functions function;
 352
 353   struct lang_hooks_for_tree_inlining tree_inlining;
 354
 355   struct lang_hooks_for_tree_dump tree_dump;
 356
 357   struct lang_hooks_for_decls decls;
 358
 359   struct lang_hooks_for_types types;
 360
 361   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 362      and langhooks.c accordingly.  */
 363 };
 364
 365 /* Each front end provides its own.  */
 366 extern const struct lang_hooks lang_hooks;
 367
 368 #endif /* GCC_LANG_HOOKS_H */