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 /* Lang hooks for management of language-specific data or status
  62    when entering / leaving functions etc.  */
  63 struct lang_hooks_for_functions
  64 {
  65   /* Called when entering a function.  */
  66   void (*init) PARAMS ((struct function *));
  67
  68   /* Called when leaving a function.  */
  69   void (*final) PARAMS ((struct function *));
  70
  71   /* Called when entering a nested function.  */
  72   void (*enter_nested) PARAMS ((struct function *));
  73
  74   /* Called when leaving a nested function.  */
  75   void (*leave_nested) PARAMS ((struct function *));
  76 };
  77
  78 /* The following hooks are used by tree-dump.c.  */
  79
  80 struct lang_hooks_for_tree_dump
  81 {
  82   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  83      does not want the usual dumping of the second argument.  */
  84   int (*dump_tree) PARAMS ((void *, tree));
  85
  86   /* Determine type qualifiers in a language-specific way.  */
  87   int (*type_quals) PARAMS ((tree));
  88 };
  89
  90 /* Hooks related to types.  */
  91
  92 struct lang_hooks_for_types
  93 {
  94   /* Return a new type (with the indicated CODE), doing whatever
  95      language-specific processing is required.  */
  96   tree (*make_type) PARAMS ((enum tree_code));
  97
  98   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  99      mode.  */
 100   tree (*type_for_mode) PARAMS ((enum machine_mode, int));
 101
 102   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
 103      integer type with at least that precision.  */
 104   tree (*type_for_size) PARAMS ((unsigned, int));
 105
 106   /* Given an integer type T, return a type like T but unsigned.
 107      If T is unsigned, the value is T.  */
 108   tree (*unsigned_type) PARAMS ((tree));
 109
 110   /* Given an integer type T, return a type like T but signed.
 111      If T is signed, the value is T.  */
 112   tree (*signed_type) PARAMS ((tree));
 113
 114   /* Return a type the same as TYPE except unsigned or signed
 115      according to UNSIGNEDP.  */
 116   tree (*signed_or_unsigned_type) PARAMS ((int, tree));
 117
 118   /* Given a type, apply default promotions to unnamed function
 119      arguments and return the new type.  Return the same type if no
 120      change.  Required by any language that supports variadic
 121      arguments.  The default hook aborts.  */
 122   tree (*type_promotes_to) PARAMS ((tree));
 123
 124   /* This routine is called in tree.c to print an error message for
 125      invalid use of an incomplete type.  VALUE is the expression that
 126      was used (or 0 if that isn't known) and TYPE is the type that was
 127      invalid.  */
 128   void (*incomplete_type_error) PARAMS ((tree value, tree type));
 129 };
 130
 131 /* Language hooks related to decls and the symbol table.  */
 132
 133 struct lang_hooks_for_decls
 134 {
 135   /* Enter a new lexical scope.  Argument is always zero when called
 136      from outside the front end.  */
 137   void (*pushlevel) PARAMS ((int));
 138
 139   /* Exit a lexical scope and return a BINDING for that scope.
 140      Takes three arguments:
 141      KEEP -- nonzero if there were declarations in this scope.
 142      REVERSE -- reverse the order of decls before returning them.
 143      FUNCTIONBODY -- nonzero if this level is the body of a function.  */
 144   tree (*poplevel) PARAMS ((int, int, int));
 145
 146   /* Returns nonzero if we are in the global binding level.  Ada
 147      returns -1 for an undocumented reason used in stor-layout.c.  */
 148   int (*global_bindings_p) PARAMS ((void));
 149
 150   /* Insert BLOCK at the end of the list of subblocks of the
 151      current binding level.  This is used when a BIND_EXPR is expanded,
 152      to handle the BLOCK node inside the BIND_EXPR.  */
 153   void (*insert_block) PARAMS ((tree));
 154
 155   /* Set the BLOCK node for the current scope level.  */
 156   void (*set_block) PARAMS ((tree));
 157
 158   /* Function to add a decl to the current scope level.  Takes one
 159      argument, a decl to add.  Returns that decl, or, if the same
 160      symbol is already declared, may return a different decl for that
 161      name.  */
 162   tree (*pushdecl) PARAMS ((tree));
 163
 164   /* Returns the chain of decls so far in the current scope level.  */
 165   tree (*getdecls) PARAMS ((void));
 166
 167   /* Returns true when we should warn for an unused global DECL.
 168      We will already have checked that it has static binding.  */
 169   bool (*warn_unused_global) PARAMS ((tree));
 170 };
 171
 172 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 173
 174 struct lang_hooks
 175 {
 176   /* String identifying the front end.  e.g. "GNU C++".  */
 177   const char *name;
 178
 179   /* sizeof (struct lang_identifier), so make_node () creates
 180      identifier nodes long enough for the language-specific slots.  */
 181   size_t identifier_size;
 182
 183   /* The first callback made to the front end, for simple
 184      initialization needed before any calls to decode_option.  */
 185   void (*init_options) PARAMS ((void));
 186
 187   /* Function called with an option vector as argument, to decode a
 188      single option (typically starting with -f or -W or +).  It should
 189      return the number of command-line arguments it uses if it handles
 190      the option, or 0 and not complain if it does not recognize the
 191      option.  If this function returns a negative number, then its
 192      absolute value is the number of command-line arguments used, but,
 193      in addition, no language-independent option processing should be
 194      done for this option.  */
 195   int (*decode_option) PARAMS ((int, char **));
 196
 197   /* Called when all command line options have been parsed.  Should do
 198      any required consistency checks, modifications etc.  Complex
 199      initialization should be left to the "init" callback, since GC
 200      and the identifier hashes are set up between now and then.
 201
 202      Should return zero unless the compiler back-end does not need to
 203      be initialized, such as with the -E option.
 204
 205      If errorcount is nonzero after this call the compiler exits
 206      immediately and the finish hook is not called.  */
 207   bool (*post_options) PARAMS ((void));
 208
 209   /* Called after post_options, to initialize the front end.  The main
 210      input filename is passed, which may be NULL; the front end should
 211      return the original filename (e.g. foo.i -> foo.c).  Return NULL
 212      to indicate a serious error of some sort; in that case no
 213      compilation is performed, and the finish hook is called
 214      immediately.  */
 215   const char * (*init) PARAMS ((const char *));
 216
 217   /* Called at the end of compilation, as a finalizer.  */
 218   void (*finish) PARAMS ((void));
 219
 220   /* Parses the entire file.  The argument is nonzero to cause bison
 221      parsers to dump debugging information during parsing.  */
 222   void (*parse_file) PARAMS ((int));
 223
 224   /* Called immediately after parsing to clear the binding stack.  */
 225   void (*clear_binding_stack) PARAMS ((void));
 226
 227   /* Called to obtain the alias set to be used for an expression or type.
 228      Returns -1 if the language does nothing special for it.  */
 229   HOST_WIDE_INT (*get_alias_set) PARAMS ((tree));
 230
 231   /* Called with an expression that is to be processed as a constant.
 232      Returns either the same expression or a language-independent
 233      constant equivalent to its input.  */
 234   tree (*expand_constant) PARAMS ((tree));
 235
 236   /* Called by expand_expr for language-specific tree codes.
 237      Fourth argument is actually an enum expand_modifier.  */
 238   rtx (*expand_expr) PARAMS ((tree, rtx, enum machine_mode, int));
 239
 240   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 241      operation.
 242
 243      This preparation consists of taking the ordinary representation
 244      of an expression expr and producing a valid tree boolean
 245      expression describing whether expr is nonzero.  We could simply
 246      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 247      but we optimize comparisons, &&, ||, and !.
 248
 249      The result should be an expression of boolean type (if not an
 250      error_mark_node).  */
 251   tree (*truthvalue_conversion) PARAMS ((tree));
 252
 253   /* Possibly apply default attributes to a function (represented by
 254      a FUNCTION_DECL).  */
 255   void (*insert_default_attributes) PARAMS ((tree));
 256
 257   /* Hook called by safe_from_p for language-specific tree codes.  It is
 258      up to the language front-end to install a hook if it has any such
 259      codes that safe_from_p needs to know about.  Since same_from_p will
 260      recursively explore the TREE_OPERANDs of an expression, this hook
 261      should not reexamine those pieces.  This routine may recursively
 262      call safe_from_p; it should always pass `0' as the TOP_P
 263      parameter.  */
 264   int (*safe_from_p) PARAMS ((rtx, tree));
 265
 266   /* Function to finish handling an incomplete decl at the end of
 267      compilation.  Default hook is does nothing.  */
 268   void (*finish_incomplete_decl) PARAMS ((tree));
 269
 270   /* Function used by unsafe_for_reeval.  A non-negative number is
 271      returned directly from unsafe_for_reeval, a negative number falls
 272      through.  The default hook returns a negative number.  */
 273   int (*unsafe_for_reeval) PARAMS ((tree));
 274
 275   /* Mark EXP saying that we need to be able to take the address of
 276      it; it should not be allocated in a register.  Return true if
 277      successful.  */
 278   bool (*mark_addressable) PARAMS ((tree));
 279
 280   /* Hook called by staticp for language-specific tree codes.  */
 281   int (*staticp) PARAMS ((tree));
 282
 283   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 284      DECL_NODE with a newly GC-allocated copy.  */
 285   void (*dup_lang_specific_decl) PARAMS ((tree));
 286
 287   /* Called before its argument, an UNSAVE_EXPR, is to be
 288      unsaved.  Modify it in-place so that all the evaluate only once
 289      things are cleared out.  */
 290   tree (*unsave_expr_now) PARAMS ((tree));
 291
 292   /* Called by expand_expr to build and return the cleanup-expression
 293      for the passed TARGET_EXPR.  Return NULL if there is none.  */
 294   tree (*maybe_build_cleanup) PARAMS ((tree));
 295
 296   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 297      thing that the assembler should talk about, set
 298      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 299      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 300      assembler does not talk about it.  */
 301   void (*set_decl_assembler_name) PARAMS ((tree));
 302
 303   /* Return nonzero if fold-const is free to use bit-field
 304      optimizations, for instance in fold_truthop().  */
 305   bool (*can_use_bit_fields_p) PARAMS ((void));
 306
 307   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
 308   bool honor_readonly;
 309
 310   /* The front end can add its own statistics to -fmem-report with
 311      this hook.  It should output to stderr.  */
 312   void (*print_statistics) PARAMS ((void));
 313
 314   /* Called by print_tree when there is a tree of class 'x' that it
 315      doesn't know how to display.  */
 316   lang_print_tree_hook print_xnode;
 317
 318   /* Called to print language-dependent parts of a class 'd', class
 319      't', and IDENTIFIER_NODE nodes.  */
 320   lang_print_tree_hook print_decl;
 321   lang_print_tree_hook print_type;
 322   lang_print_tree_hook print_identifier;
 323
 324   /* Computes the name to use to print a declaration.  DECL is the
 325      non-NULL declaration in question.  VERBOSITY determines what
 326      information will be printed: 0: DECL_NAME, demangled as
 327      necessary.  1: and scope information.  2: and any other
 328      information that might be interesting, such as function parameter
 329      types in C++.  */
 330   const char *(*decl_printable_name) PARAMS ((tree decl, int verbosity));
 331
 332   /* Called by report_error_function to print out function name.  */
 333   void (*print_error_function) PARAMS ((struct diagnostic_context *,
 334                                         const char *));
 335
 336   /* Called from expr_size to calculate the size of the value of an
 337      expression in a language-dependent way.  Returns a tree for the size
 338      in bytes.  A frontend can call lhd_expr_size to get the default
 339      semantics in cases that it doesn't want to handle specially.  */
 340   tree (*expr_size) PARAMS ((tree));
 341
 342   /* Pointers to machine-independent attribute tables, for front ends
 343      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 344      table of attributes specific to the language, a table of
 345      attributes common to two or more languages (to allow easy
 346      sharing), and a table of attributes for checking formats.  */
 347   const struct attribute_spec *attribute_table;
 348   const struct attribute_spec *common_attribute_table;
 349   const struct attribute_spec *format_attribute_table;
 350
 351   /* Function-related language hooks.  */
 352   struct lang_hooks_for_functions function;
 353
 354   struct lang_hooks_for_tree_inlining tree_inlining;
 355
 356   struct lang_hooks_for_tree_dump tree_dump;
 357
 358   struct lang_hooks_for_decls decls;
 359
 360   struct lang_hooks_for_types types;
 361
 362   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 363      and langhooks.c accordingly.  */
 364 };
 365
 366 /* Each front end provides its own.  */
 367 extern const struct lang_hooks lang_hooks;
 368
 369 #endif /* GCC_LANG_HOOKS_H */