gcc/cp/name-lookup.h

   1 /* Declarations for C++ name lookup routines.
   2    Copyright (C) 2003, 2004, 2005  Free Software Foundation, Inc.
   3    Contributed by Gabriel Dos Reis <gdr@integrable-solutions.net>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #ifndef GCC_CP_NAME_LOOKUP_H
  23 #define GCC_CP_NAME_LOOKUP_H
  24
  25 #include "c-common.h"
  26
  27 /* The type of dictionary used to map names to types declared at
  28    a given scope.  */
  29 typedef struct binding_table_s *binding_table;
  30 typedef struct binding_entry_s *binding_entry;
  31
  32 /* The type of a routine repeatedly called by binding_table_foreach.  */
  33 typedef void (*bt_foreach_proc) (binding_entry, void *);
  34
  35 struct binding_entry_s GTY(())
  36 {
  37   binding_entry chain;
  38   tree name;
  39   tree type;
  40 };
  41
  42 /* These macros indicate the initial chains count for binding_table.  */
  43 #define SCOPE_DEFAULT_HT_SIZE                        (1 << 3)
  44 #define CLASS_SCOPE_HT_SIZE                          (1 << 3)
  45 #define NAMESPACE_ORDINARY_HT_SIZE                   (1 << 5)
  46 #define NAMESPACE_STD_HT_SIZE                        (1 << 8)
  47 #define GLOBAL_SCOPE_HT_SIZE                         (1 << 8)
  48
  49 extern void binding_table_foreach (binding_table, bt_foreach_proc, void *);
  50 extern binding_entry binding_table_find (binding_table, tree);
  51 \f
  52 /* Datatype that represents binding established by a declaration between
  53    a name and a C++ entity.  */
  54 typedef struct cxx_binding cxx_binding;
  55
  56 /* The datatype used to implement C++ scope.  */
  57 typedef struct cp_binding_level cxx_scope;
  58
  59 /* Nonzero if this binding is for a local scope, as opposed to a class
  60    or namespace scope.  */
  61 #define LOCAL_BINDING_P(NODE) ((NODE)->is_local)
  62
  63 /* True if NODE->value is from a base class of the class which is
  64    currently being defined.  */
  65 #define INHERITED_VALUE_BINDING_P(NODE) ((NODE)->value_is_inherited)
  66
  67 struct cxx_binding GTY(())
  68 {
  69   /* Link to chain together various bindings for this name.  */
  70   cxx_binding *previous;
  71   /* The non-type entity this name is bound to.  */
  72   tree value;
  73   /* The type entity this name is bound to.  */
  74   tree type;
  75   /* The scope at which this binding was made.  */
  76   cxx_scope *scope;
  77   unsigned value_is_inherited : 1;
  78   unsigned is_local : 1;
  79 };
  80
  81 /* Datatype used to temporarily save C++ bindings (for implicit
  82    instantiations purposes and like).  Implemented in decl.c.  */
  83 typedef struct cxx_saved_binding GTY(())
  84 {
  85   /* The name of the current binding.  */
  86   tree identifier;
  87   /* The binding we're saving.  */
  88   cxx_binding *binding;
  89   tree real_type_value;
  90 } cxx_saved_binding;
  91
  92 DEF_VEC_GC_O(cxx_saved_binding);
  93
  94 extern tree identifier_type_value (tree);
  95 extern void set_identifier_type_value (tree, tree);
  96 extern void pop_binding (tree, tree);
  97 extern tree constructor_name (tree);
  98 extern bool constructor_name_p (tree, tree);
  99 \f
 100 /* The kinds of scopes we recognize.  */
 101 typedef enum scope_kind {
 102   sk_block = 0,      /* An ordinary block scope.  This enumerator must
 103                         have the value zero because "cp_binding_level"
 104                         is initialized by using "memset" to set the
 105                         contents to zero, and the default scope kind
 106                         is "sk_block".  */
 107   sk_cleanup,        /* A scope for (pseudo-)scope for cleanup.  It is
 108                         peusdo in that it is transparent to name lookup
 109                         activities.  */
 110   sk_try,            /* A try-block.  */
 111   sk_catch,          /* A catch-block.  */
 112   sk_for,            /* The scope of the variable declared in a
 113                         for-init-statement.  */
 114   sk_function_parms, /* The scope containing function parameters.  */
 115   sk_class,          /* The scope containing the members of a class.  */
 116   sk_namespace,      /* The scope containing the members of a
 117                         namespace, including the global scope.  */
 118   sk_template_parms, /* A scope for template parameters.  */
 119   sk_template_spec   /* Like sk_template_parms, but for an explicit
 120                         specialization.  Since, by definition, an
 121                         explicit specialization is introduced by
 122                         "template <>", this scope is always empty.  */
 123 } scope_kind;
 124
 125 /* The scope where the class/struct/union/enum tag applies.  */
 126 typedef enum tag_scope {
 127   ts_current = 0,       /* Current scope only.  This is for the
 128                              class-key identifier;
 129                            case mentioned in [basic.lookup.elab]/2,
 130                            or the class/enum definition
 131                              class-key identifier { ... };  */
 132   ts_global = 1,        /* All scopes.  This is the 3.4.1
 133                            [basic.lookup.unqual] lookup mentioned
 134                            in [basic.lookup.elab]/2.  */
 135   ts_within_enclosing_non_class = 2     /* Search within enclosing non-class
 136                                            only, for friend class lookup
 137                                            according to [namespace.memdef]/3
 138                                            and [class.friend]/9.  */
 139 } tag_scope;
 140
 141 typedef struct cp_class_binding GTY(())
 142 {
 143   cxx_binding base;
 144   /* The bound name.  */
 145   tree identifier;
 146 } cp_class_binding;
 147
 148 DEF_VEC_GC_O(cp_class_binding);
 149
 150 /* For each binding contour we allocate a binding_level structure
 151    which records the names defined in that contour.
 152    Contours include:
 153     0) the global one
 154     1) one for each function definition,
 155        where internal declarations of the parameters appear.
 156     2) one for each compound statement,
 157        to record its declarations.
 158
 159    The current meaning of a name can be found by searching the levels
 160    from the current one out to the global one.
 161
 162    Off to the side, may be the class_binding_level.  This exists only
 163    to catch class-local declarations.  It is otherwise nonexistent.
 164
 165    Also there may be binding levels that catch cleanups that must be
 166    run when exceptions occur.  Thus, to see whether a name is bound in
 167    the current scope, it is not enough to look in the
 168    CURRENT_BINDING_LEVEL.  You should use lookup_name_current_level
 169    instead.  */
 170
 171 /* Note that the information in the `names' component of the global contour
 172    is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers.  */
 173
 174 struct cp_binding_level GTY(())
 175   {
 176     /* A chain of _DECL nodes for all variables, constants, functions,
 177        and typedef types.  These are in the reverse of the order
 178        supplied.  There may be OVERLOADs on this list, too, but they
 179        are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 180     tree names;
 181
 182     /* Count of elements in names chain.  */
 183     size_t names_size;
 184
 185     /* A chain of NAMESPACE_DECL nodes.  */
 186     tree namespaces;
 187
 188     /* An array of static functions and variables (for namespaces only) */
 189     varray_type static_decls;
 190
 191     /* A chain of VTABLE_DECL nodes.  */
 192     tree vtables;
 193
 194     /* A list of USING_DECL nodes.  */
 195     tree usings;
 196
 197     /* A list of used namespaces. PURPOSE is the namespace,
 198        VALUE the common ancestor with this binding_level's namespace.  */
 199     tree using_directives;
 200
 201     /* For the binding level corresponding to a class, the entities
 202        declared in the class or its base classes.  */
 203     VEC(cp_class_binding) *class_shadowed;
 204
 205     /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 206        is used for all binding levels. The TREE_PURPOSE is the name of
 207        the entity, the TREE_TYPE is the associated type.  In addition
 208        the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
 209        the class.  */
 210     tree type_shadowed;
 211
 212     /* A TREE_LIST.  Each TREE_VALUE is the LABEL_DECL for a local
 213        label in this scope.  The TREE_PURPOSE is the previous value of
 214        the IDENTIFIER_LABEL VALUE.  */
 215     tree shadowed_labels;
 216
 217     /* For each level (except not the global one),
 218        a chain of BLOCK nodes for all the levels
 219        that were entered and exited one level down.  */
 220     tree blocks;
 221
 222     /* The entity (namespace, class, function) the scope of which this
 223        binding contour corresponds to.  Otherwise NULL.  */
 224     tree this_entity;
 225
 226     /* The binding level which this one is contained in (inherits from).  */
 227     struct cp_binding_level *level_chain;
 228
 229     /* List of VAR_DECLS saved from a previous for statement.
 230        These would be dead in ISO-conforming code, but might
 231        be referenced in ARM-era code.  These are stored in a
 232        TREE_LIST; the TREE_VALUE is the actual declaration.  */
 233     tree dead_vars_from_for;
 234
 235     /* STATEMENT_LIST for statements in this binding contour.
 236        Only used at present for SK_CLEANUP temporary bindings.  */
 237     tree statement_list;
 238
 239     /* Binding depth at which this level began.  */
 240     int binding_depth;
 241
 242     /* The kind of scope that this object represents.  However, a
 243        SK_TEMPLATE_SPEC scope is represented with KIND set to
 244        SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true.  */
 245     ENUM_BITFIELD (scope_kind) kind : 4;
 246
 247     /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 248        only valid if KIND == SK_TEMPLATE_PARMS.  */
 249     BOOL_BITFIELD explicit_spec_p : 1;
 250
 251     /* true means make a BLOCK for this level regardless of all else.  */
 252     unsigned keep : 1;
 253
 254     /* Nonzero if this level can safely have additional
 255        cleanup-needing variables added to it.  */
 256     unsigned more_cleanups_ok : 1;
 257     unsigned have_cleanups : 1;
 258
 259     /* 22 bits left to fill a 32-bit word.  */
 260   };
 261
 262 /* The binding level currently in effect.  */
 263
 264 #define current_binding_level                   \
 265   (*(cfun && cp_function_chain->bindings        \
 266    ? &cp_function_chain->bindings               \
 267    : &scope_chain->bindings))
 268
 269 /* The binding level of the current class, if any.  */
 270
 271 #define class_binding_level scope_chain->class_bindings
 272
 273 /* The tree node representing the global scope.  */
 274 extern GTY(()) tree global_namespace;
 275 extern GTY(()) tree global_scope_name;
 276
 277 /* Indicates that there is a type value in some namespace, although
 278    that is not necessarily in scope at the moment.  */
 279
 280 extern GTY(()) tree global_type_node;
 281
 282 /* True if SCOPE designates the global scope binding contour.  */
 283 #define global_scope_p(SCOPE) \
 284   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 285
 286 extern cxx_scope *leave_scope (void);
 287 extern bool kept_level_p (void);
 288 extern int global_bindings_p (void);
 289 extern bool toplevel_bindings_p (void);
 290 extern bool namespace_bindings_p (void);
 291 extern bool template_parm_scope_p (void);
 292 extern scope_kind innermost_scope_kind (void);
 293 extern cxx_scope *begin_scope (scope_kind, tree);
 294 extern void print_binding_stack (void);
 295 extern void push_to_top_level (void);
 296 extern void pop_from_top_level (void);
 297 extern void pop_everything (void);
 298 extern void keep_next_level (bool);
 299 extern bool is_ancestor (tree, tree);
 300 extern tree push_scope (tree);
 301 extern void pop_scope (tree);
 302 extern tree push_inner_scope (tree);
 303 extern void pop_inner_scope (tree, tree);
 304 extern void push_binding_level (struct cp_binding_level *);
 305 \f
 306 extern void push_namespace (tree);
 307 extern void pop_namespace (void);
 308 extern void push_nested_namespace (tree);
 309 extern void pop_nested_namespace (tree);
 310 extern void pushlevel_class (void);
 311 extern void poplevel_class (void);
 312 extern tree pushdecl_with_scope (tree, cxx_scope *);
 313 extern tree lookup_name (tree, int);
 314 extern tree lookup_name_real (tree, int, int, bool, int, int);
 315 extern tree lookup_type_scope (tree, tag_scope);
 316 extern tree namespace_binding (tree, tree);
 317 extern void set_namespace_binding (tree, tree, tree);
 318 extern tree lookup_namespace_name (tree, tree);
 319 extern tree lookup_qualified_name (tree, tree, bool, bool);
 320 extern tree lookup_name_nonclass (tree);
 321 extern tree lookup_function_nonclass (tree, tree, bool);
 322 extern void push_local_binding (tree, tree, int);
 323 extern bool pushdecl_class_level (tree);
 324 extern tree pushdecl_namespace_level (tree);
 325 extern bool push_class_level_binding (tree, tree);
 326 extern tree getdecls (void);
 327 extern tree cp_namespace_decls (tree);
 328 extern void set_decl_namespace (tree, tree, bool);
 329 extern void push_decl_namespace (tree);
 330 extern void pop_decl_namespace (void);
 331 extern void do_namespace_alias (tree, tree);
 332 extern void do_toplevel_using_decl (tree, tree, tree);
 333 extern void do_local_using_decl (tree, tree, tree);
 334 extern tree do_class_using_decl (tree, tree);
 335 extern void do_using_directive (tree);
 336 extern tree lookup_arg_dependent (tree, tree, tree);
 337 extern bool is_associated_namespace (tree, tree);
 338 extern void parse_using_directive (tree, tree);
 339 extern tree innermost_non_namespace_value (tree);
 340 extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
 341
 342 /* Set *DECL to the (non-hidden) declaration for ID at global scope,
 343    if present and return true; otherwise return false.  */
 344
 345 static inline bool
 346 get_global_value_if_present (tree id, tree *decl)
 347 {
 348   tree global_value = namespace_binding (id, global_namespace);
 349   if (global_value)
 350     *decl = global_value;
 351   return global_value != NULL;
 352 }
 353
 354 /* True is the binding of IDENTIFIER at global scope names a type.  */
 355
 356 static inline bool
 357 is_typename_at_global_scope (tree id)
 358 {
 359   tree global_value = namespace_binding (id, global_namespace);
 360
 361   return global_value && TREE_CODE (global_value) == TYPE_DECL;
 362 }
 363
 364 #endif /* GCC_CP_NAME_LOOKUP_H */