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   /* Do necessary preparations before assemble_variable can proceed.  */
 185   void (*prepare_assemble_variable) PARAMS ((tree));
 186
 187   /* True if this decl may be called via a sibcall.  */
 188   bool (*ok_for_sibcall) PARAMS ((tree));
 189 };
 190
 191 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 192
 193 struct lang_hooks
 194 {
 195   /* String identifying the front end.  e.g. "GNU C++".  */
 196   const char *name;
 197
 198   /* sizeof (struct lang_identifier), so make_node () creates
 199      identifier nodes long enough for the language-specific slots.  */
 200   size_t identifier_size;
 201
 202   /* Determines the size of any language-specific 'x' or 'c' nodes.
 203      Since it is called from make_node, the only information available
 204      is the tree code.  Expected to abort on unrecognized codes.  */
 205   size_t (*tree_size) PARAMS ((enum tree_code));
 206
 207   /* The first callback made to the front end, for simple
 208      initialization needed before any calls to handle_option.  Return
 209      the language mask to filter the switch array with.  */
 210   int (*init_options) PARAMS ((void));
 211
 212   /* Handle the switch CODE, which has real type enum opt_code from
 213      options.h.  If the switch takes an argument, it is passed in ARG
 214      which points to permanent storage.  The handler is resonsible for
 215      checking whether ARG is NULL, which indicates that no argument
 216      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 217      for the positive and negative forms respectively.
 218
 219      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 220      valid and should not be treated as language-independent too.  */
 221   int (*handle_option) (size_t code, const char *arg, int value);
 222
 223   /* Called when all command line options have been parsed to allow
 224      further processing and initialization
 225
 226      Should return true to indicate that a compiler back-end is
 227      not required, such as with the -E option.
 228
 229      If errorcount is nonzero after this call the compiler exits
 230      immediately and the finish hook is not called.  */
 231   bool (*post_options) PARAMS ((const char **));
 232
 233   /* Called after post_options to initialize the front end.  Return
 234      false to indicate that no further compilation be performed, in
 235      which case the finish hook is called immediately.  */
 236   bool (*init) PARAMS ((void));
 237
 238   /* Called at the end of compilation, as a finalizer.  */
 239   void (*finish) PARAMS ((void));
 240
 241   /* Parses the entire file.  The argument is nonzero to cause bison
 242      parsers to dump debugging information during parsing.  */
 243   void (*parse_file) PARAMS ((int));
 244
 245   /* Called immediately after parsing to clear the binding stack.  */
 246   void (*clear_binding_stack) PARAMS ((void));
 247
 248   /* Called to obtain the alias set to be used for an expression or type.
 249      Returns -1 if the language does nothing special for it.  */
 250   HOST_WIDE_INT (*get_alias_set) PARAMS ((tree));
 251
 252   /* Called with an expression that is to be processed as a constant.
 253      Returns either the same expression or a language-independent
 254      constant equivalent to its input.  */
 255   tree (*expand_constant) PARAMS ((tree));
 256
 257   /* Called by expand_expr for language-specific tree codes.
 258      Fourth argument is actually an enum expand_modifier.  */
 259   rtx (*expand_expr) PARAMS ((tree, rtx, enum machine_mode, int));
 260
 261   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 262      operation.
 263
 264      This preparation consists of taking the ordinary representation
 265      of an expression expr and producing a valid tree boolean
 266      expression describing whether expr is nonzero.  We could simply
 267      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 268      but we optimize comparisons, &&, ||, and !.
 269
 270      The result should be an expression of boolean type (if not an
 271      error_mark_node).  */
 272   tree (*truthvalue_conversion) PARAMS ((tree));
 273
 274   /* Possibly apply default attributes to a function (represented by
 275      a FUNCTION_DECL).  */
 276   void (*insert_default_attributes) PARAMS ((tree));
 277
 278   /* Hook called by safe_from_p for language-specific tree codes.  It is
 279      up to the language front-end to install a hook if it has any such
 280      codes that safe_from_p needs to know about.  Since same_from_p will
 281      recursively explore the TREE_OPERANDs of an expression, this hook
 282      should not reexamine those pieces.  This routine may recursively
 283      call safe_from_p; it should always pass `0' as the TOP_P
 284      parameter.  */
 285   int (*safe_from_p) PARAMS ((rtx, tree));
 286
 287   /* Function to finish handling an incomplete decl at the end of
 288      compilation.  Default hook is does nothing.  */
 289   void (*finish_incomplete_decl) PARAMS ((tree));
 290
 291   /* Function used by unsafe_for_reeval.  A non-negative number is
 292      returned directly from unsafe_for_reeval, a negative number falls
 293      through.  The default hook returns a negative number.  */
 294   int (*unsafe_for_reeval) PARAMS ((tree));
 295
 296   /* Mark EXP saying that we need to be able to take the address of
 297      it; it should not be allocated in a register.  Return true if
 298      successful.  */
 299   bool (*mark_addressable) PARAMS ((tree));
 300
 301   /* Hook called by staticp for language-specific tree codes.  */
 302   int (*staticp) PARAMS ((tree));
 303
 304   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 305      DECL_NODE with a newly GC-allocated copy.  */
 306   void (*dup_lang_specific_decl) PARAMS ((tree));
 307
 308   /* Called before its argument, an UNSAVE_EXPR, is to be
 309      unsaved.  Modify it in-place so that all the evaluate only once
 310      things are cleared out.  */
 311   tree (*unsave_expr_now) PARAMS ((tree));
 312
 313   /* Called by expand_expr to build and return the cleanup-expression
 314      for the passed TARGET_EXPR.  Return NULL if there is none.  */
 315   tree (*maybe_build_cleanup) PARAMS ((tree));
 316
 317   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 318      thing that the assembler should talk about, set
 319      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 320      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 321      assembler does not talk about it.  */
 322   void (*set_decl_assembler_name) PARAMS ((tree));
 323
 324   /* Return nonzero if fold-const is free to use bit-field
 325      optimizations, for instance in fold_truthop().  */
 326   bool (*can_use_bit_fields_p) PARAMS ((void));
 327
 328   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
 329   bool honor_readonly;
 330
 331   /* Nonzero if this front end does not generate a dummy BLOCK between
 332      the outermost scope of the function and the FUNCTION_DECL.  See
 333      is_body_block in stmt.c, and its callers.  */
 334   bool no_body_blocks;
 335
 336   /* The front end can add its own statistics to -fmem-report with
 337      this hook.  It should output to stderr.  */
 338   void (*print_statistics) PARAMS ((void));
 339
 340   /* Called by print_tree when there is a tree of class 'x' that it
 341      doesn't know how to display.  */
 342   lang_print_tree_hook print_xnode;
 343
 344   /* Called to print language-dependent parts of a class 'd', class
 345      't', and IDENTIFIER_NODE nodes.  */
 346   lang_print_tree_hook print_decl;
 347   lang_print_tree_hook print_type;
 348   lang_print_tree_hook print_identifier;
 349
 350   /* Computes the name to use to print a declaration.  DECL is the
 351      non-NULL declaration in question.  VERBOSITY determines what
 352      information will be printed: 0: DECL_NAME, demangled as
 353      necessary.  1: and scope information.  2: and any other
 354      information that might be interesting, such as function parameter
 355      types in C++.  */
 356   const char *(*decl_printable_name) PARAMS ((tree decl, int verbosity));
 357
 358   /* Called by report_error_function to print out function name.  */
 359   void (*print_error_function) PARAMS ((struct diagnostic_context *,
 360                                         const char *));
 361
 362   /* Called from expr_size to calculate the size of the value of an
 363      expression in a language-dependent way.  Returns a tree for the size
 364      in bytes.  A frontend can call lhd_expr_size to get the default
 365      semantics in cases that it doesn't want to handle specially.  */
 366   tree (*expr_size) PARAMS ((tree));
 367
 368   /* Pointers to machine-independent attribute tables, for front ends
 369      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 370      table of attributes specific to the language, a table of
 371      attributes common to two or more languages (to allow easy
 372      sharing), and a table of attributes for checking formats.  */
 373   const struct attribute_spec *attribute_table;
 374   const struct attribute_spec *common_attribute_table;
 375   const struct attribute_spec *format_attribute_table;
 376
 377   /* Function-related language hooks.  */
 378   struct lang_hooks_for_functions function;
 379
 380   struct lang_hooks_for_tree_inlining tree_inlining;
 381
 382   struct lang_hooks_for_callgraph callgraph;
 383
 384   struct lang_hooks_for_tree_dump tree_dump;
 385
 386   struct lang_hooks_for_decls decls;
 387
 388   struct lang_hooks_for_types types;
 389
 390   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 391      and langhooks.c accordingly.  */
 392 };
 393
 394 /* Each front end provides its own.  */
 395 extern const struct lang_hooks lang_hooks;
 396
 397 #endif /* GCC_LANG_HOOKS_H */