gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright 2001, 2002 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) 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   bool (*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   /* True if this decl may be called via a sibcall.  */
 185   bool (*ok_for_sibcall) PARAMS ((tree));
 186 };
 187
 188 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 189
 190 struct lang_hooks
 191 {
 192   /* String identifying the front end.  e.g. "GNU C++".  */
 193   const char *name;
 194
 195   /* sizeof (struct lang_identifier), so make_node () creates
 196      identifier nodes long enough for the language-specific slots.  */
 197   size_t identifier_size;
 198
 199   /* Determines the size of any language-specific 'x' or 'c' nodes.
 200      Since it is called from make_node, the only information available
 201      is the tree code.  Expected to abort on unrecognized codes.  */
 202   size_t (*tree_size) PARAMS ((enum tree_code));
 203
 204   /* The first callback made to the front end, for simple
 205      initialization needed before any calls to handle_option.  Return
 206      the language mask to filter the switch array with.  */
 207   int (*init_options) PARAMS ((void));
 208
 209   /* Handle the switch CODE, which has real type enum opt_code from
 210      options.h.  If the switch takes an argument, it is passed in ARG
 211      which points to permanent storage.  The handler is resonsible for
 212      checking whether ARG is NULL, which indicates that no argument
 213      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 214      for the positive and negative forms respectively.
 215
 216      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 217      valid and should not be treated as language-independent too.  */
 218   int (*handle_option) (size_t code, const char *arg, int value);
 219
 220   /* Called when all command line options have been parsed to allow
 221      further processing and initialization
 222
 223      Should return true to indicate that a compiler back-end is
 224      not required, such as with the -E option.
 225
 226      If errorcount is nonzero after this call the compiler exits
 227      immediately and the finish hook is not called.  */
 228   bool (*post_options) PARAMS ((const char **));
 229
 230   /* Called after post_options to initialize the front end.  Return
 231      false to indicate that no further compilation be performed, in
 232      which case the finish hook is called immediately.  */
 233   bool (*init) PARAMS ((void));
 234
 235   /* Called at the end of compilation, as a finalizer.  */
 236   void (*finish) PARAMS ((void));
 237
 238   /* Parses the entire file.  The argument is nonzero to cause bison
 239      parsers to dump debugging information during parsing.  */
 240   void (*parse_file) PARAMS ((int));
 241
 242   /* Called immediately after parsing to clear the binding stack.  */
 243   void (*clear_binding_stack) PARAMS ((void));
 244
 245   /* Called to obtain the alias set to be used for an expression or type.
 246      Returns -1 if the language does nothing special for it.  */
 247   HOST_WIDE_INT (*get_alias_set) PARAMS ((tree));
 248
 249   /* Called with an expression that is to be processed as a constant.
 250      Returns either the same expression or a language-independent
 251      constant equivalent to its input.  */
 252   tree (*expand_constant) PARAMS ((tree));
 253
 254   /* Called by expand_expr for language-specific tree codes.
 255      Fourth argument is actually an enum expand_modifier.  */
 256   rtx (*expand_expr) PARAMS ((tree, rtx, enum machine_mode, int));
 257
 258   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 259      operation.
 260
 261      This preparation consists of taking the ordinary representation
 262      of an expression expr and producing a valid tree boolean
 263      expression describing whether expr is nonzero.  We could simply
 264      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 265      but we optimize comparisons, &&, ||, and !.
 266
 267      The result should be an expression of boolean type (if not an
 268      error_mark_node).  */
 269   tree (*truthvalue_conversion) PARAMS ((tree));
 270
 271   /* Possibly apply default attributes to a function (represented by
 272      a FUNCTION_DECL).  */
 273   void (*insert_default_attributes) PARAMS ((tree));
 274
 275   /* Hook called by safe_from_p for language-specific tree codes.  It is
 276      up to the language front-end to install a hook if it has any such
 277      codes that safe_from_p needs to know about.  Since same_from_p will
 278      recursively explore the TREE_OPERANDs of an expression, this hook
 279      should not reexamine those pieces.  This routine may recursively
 280      call safe_from_p; it should always pass `0' as the TOP_P
 281      parameter.  */
 282   int (*safe_from_p) PARAMS ((rtx, tree));
 283
 284   /* Function to finish handling an incomplete decl at the end of
 285      compilation.  Default hook is does nothing.  */
 286   void (*finish_incomplete_decl) PARAMS ((tree));
 287
 288   /* Function used by unsafe_for_reeval.  A non-negative number is
 289      returned directly from unsafe_for_reeval, a negative number falls
 290      through.  The default hook returns a negative number.  */
 291   int (*unsafe_for_reeval) PARAMS ((tree));
 292
 293   /* Mark EXP saying that we need to be able to take the address of
 294      it; it should not be allocated in a register.  Return true if
 295      successful.  */
 296   bool (*mark_addressable) PARAMS ((tree));
 297
 298   /* Hook called by staticp for language-specific tree codes.  */
 299   int (*staticp) PARAMS ((tree));
 300
 301   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 302      DECL_NODE with a newly GC-allocated copy.  */
 303   void (*dup_lang_specific_decl) PARAMS ((tree));
 304
 305   /* Called before its argument, an UNSAVE_EXPR, is to be
 306      unsaved.  Modify it in-place so that all the evaluate only once
 307      things are cleared out.  */
 308   tree (*unsave_expr_now) PARAMS ((tree));
 309
 310   /* Called by expand_expr to build and return the cleanup-expression
 311      for the passed TARGET_EXPR.  Return NULL if there is none.  */
 312   tree (*maybe_build_cleanup) PARAMS ((tree));
 313
 314   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 315      thing that the assembler should talk about, set
 316      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 317      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 318      assembler does not talk about it.  */
 319   void (*set_decl_assembler_name) PARAMS ((tree));
 320
 321   /* Return nonzero if fold-const is free to use bit-field
 322      optimizations, for instance in fold_truthop().  */
 323   bool (*can_use_bit_fields_p) PARAMS ((void));
 324
 325   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
 326   bool honor_readonly;
 327
 328   /* The front end can add its own statistics to -fmem-report with
 329      this hook.  It should output to stderr.  */
 330   void (*print_statistics) PARAMS ((void));
 331
 332   /* Called by print_tree when there is a tree of class 'x' that it
 333      doesn't know how to display.  */
 334   lang_print_tree_hook print_xnode;
 335
 336   /* Called to print language-dependent parts of a class 'd', class
 337      't', and IDENTIFIER_NODE nodes.  */
 338   lang_print_tree_hook print_decl;
 339   lang_print_tree_hook print_type;
 340   lang_print_tree_hook print_identifier;
 341
 342   /* Computes the name to use to print a declaration.  DECL is the
 343      non-NULL declaration in question.  VERBOSITY determines what
 344      information will be printed: 0: DECL_NAME, demangled as
 345      necessary.  1: and scope information.  2: and any other
 346      information that might be interesting, such as function parameter
 347      types in C++.  */
 348   const char *(*decl_printable_name) PARAMS ((tree decl, int verbosity));
 349
 350   /* Called by report_error_function to print out function name.  */
 351   void (*print_error_function) PARAMS ((struct diagnostic_context *,
 352                                         const char *));
 353
 354   /* Called from expr_size to calculate the size of the value of an
 355      expression in a language-dependent way.  Returns a tree for the size
 356      in bytes.  A frontend can call lhd_expr_size to get the default
 357      semantics in cases that it doesn't want to handle specially.  */
 358   tree (*expr_size) PARAMS ((tree));
 359
 360   /* Pointers to machine-independent attribute tables, for front ends
 361      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 362      table of attributes specific to the language, a table of
 363      attributes common to two or more languages (to allow easy
 364      sharing), and a table of attributes for checking formats.  */
 365   const struct attribute_spec *attribute_table;
 366   const struct attribute_spec *common_attribute_table;
 367   const struct attribute_spec *format_attribute_table;
 368
 369   /* Function-related language hooks.  */
 370   struct lang_hooks_for_functions function;
 371
 372   struct lang_hooks_for_tree_inlining tree_inlining;
 373
 374   struct lang_hooks_for_callgraph callgraph;
 375
 376   struct lang_hooks_for_tree_dump tree_dump;
 377
 378   struct lang_hooks_for_decls decls;
 379
 380   struct lang_hooks_for_types types;
 381
 382   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 383      and langhooks.c accordingly.  */
 384 };
 385
 386 /* Each front end provides its own.  */
 387 extern const struct lang_hooks lang_hooks;
 388
 389 #endif /* GCC_LANG_HOOKS_H */