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_full (tree);
  98 extern tree constructor_name (tree);
  99 extern bool constructor_name_p (tree, tree);
 100 \f
 101 /* The kinds of scopes we recognize.  */
 102 typedef enum scope_kind {
 103   sk_block = 0,      /* An ordinary block scope.  This enumerator must
 104                         have the value zero because "cp_binding_level"
 105                         is initialized by using "memset" to set the
 106                         contents to zero, and the default scope kind
 107                         is "sk_block".  */
 108   sk_cleanup,        /* A scope for (pseudo-)scope for cleanup.  It is
 109                         peusdo in that it is transparent to name lookup
 110                         activities.  */
 111   sk_try,            /* A try-block.  */
 112   sk_catch,          /* A catch-block.  */
 113   sk_for,            /* The scope of the variable declared in a
 114                         for-init-statement.  */
 115   sk_function_parms, /* The scope containing function parameters.  */
 116   sk_class,          /* The scope containing the members of a class.  */
 117   sk_namespace,      /* The scope containing the members of a
 118                         namespace, including the global scope.  */
 119   sk_template_parms, /* A scope for template parameters.  */
 120   sk_template_spec   /* Like sk_template_parms, but for an explicit
 121                         specialization.  Since, by definition, an
 122                         explicit specialization is introduced by
 123                         "template <>", this scope is always empty.  */
 124 } scope_kind;
 125
 126 /* The scope where the class/struct/union/enum tag applies.  */
 127 typedef enum tag_scope {
 128   ts_current = 0,       /* Current scope only.  This is for the
 129                              class-key identifier;
 130                            case mentioned in [basic.lookup.elab]/2,
 131                            or the class/enum definition
 132                              class-key identifier { ... };  */
 133   ts_global = 1,        /* All scopes.  This is the 3.4.1
 134                            [basic.lookup.unqual] lookup mentioned
 135                            in [basic.lookup.elab]/2.  */
 136   ts_within_enclosing_non_class = 2     /* Search within enclosing non-class
 137                                            only, for friend class lookup
 138                                            according to [namespace.memdef]/3
 139                                            and [class.friend]/9.  */
 140 } tag_scope;
 141
 142 typedef struct cp_class_binding GTY(())
 143 {
 144   cxx_binding base;
 145   /* The bound name.  */
 146   tree identifier;
 147 } cp_class_binding;
 148
 149 DEF_VEC_GC_O(cp_class_binding);
 150
 151 /* For each binding contour we allocate a binding_level structure
 152    which records the names defined in that contour.
 153    Contours include:
 154     0) the global one
 155     1) one for each function definition,
 156        where internal declarations of the parameters appear.
 157     2) one for each compound statement,
 158        to record its declarations.
 159
 160    The current meaning of a name can be found by searching the levels
 161    from the current one out to the global one.
 162
 163    Off to the side, may be the class_binding_level.  This exists only
 164    to catch class-local declarations.  It is otherwise nonexistent.
 165
 166    Also there may be binding levels that catch cleanups that must be
 167    run when exceptions occur.  Thus, to see whether a name is bound in
 168    the current scope, it is not enough to look in the
 169    CURRENT_BINDING_LEVEL.  You should use lookup_name_current_level
 170    instead.  */
 171
 172 /* Note that the information in the `names' component of the global contour
 173    is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers.  */
 174
 175 struct cp_binding_level GTY(())
 176   {
 177     /* A chain of _DECL nodes for all variables, constants, functions,
 178        and typedef types.  These are in the reverse of the order
 179        supplied.  There may be OVERLOADs on this list, too, but they
 180        are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 181     tree names;
 182
 183     /* Count of elements in names chain.  */
 184     size_t names_size;
 185
 186     /* A chain of NAMESPACE_DECL nodes.  */
 187     tree namespaces;
 188
 189     /* An array of static functions and variables (for namespaces only) */
 190     varray_type static_decls;
 191
 192     /* A chain of VTABLE_DECL nodes.  */
 193     tree vtables;
 194
 195     /* A list of USING_DECL nodes.  */
 196     tree usings;
 197
 198     /* A list of used namespaces. PURPOSE is the namespace,
 199        VALUE the common ancestor with this binding_level's namespace.  */
 200     tree using_directives;
 201
 202     /* For the binding level corresponding to a class, the entities
 203        declared in the class or its base classes.  */
 204     VEC(cp_class_binding) *class_shadowed;
 205
 206     /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 207        is used for all binding levels. The TREE_PURPOSE is the name of
 208        the entity, the TREE_TYPE is the associated type.  In addition
 209        the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
 210        the class.  */
 211     tree type_shadowed;
 212
 213     /* A TREE_LIST.  Each TREE_VALUE is the LABEL_DECL for a local
 214        label in this scope.  The TREE_PURPOSE is the previous value of
 215        the IDENTIFIER_LABEL VALUE.  */
 216     tree shadowed_labels;
 217
 218     /* For each level (except not the global one),
 219        a chain of BLOCK nodes for all the levels
 220        that were entered and exited one level down.  */
 221     tree blocks;
 222
 223     /* The entity (namespace, class, function) the scope of which this
 224        binding contour corresponds to.  Otherwise NULL.  */
 225     tree this_entity;
 226
 227     /* The binding level which this one is contained in (inherits from).  */
 228     struct cp_binding_level *level_chain;
 229
 230     /* List of VAR_DECLS saved from a previous for statement.
 231        These would be dead in ISO-conforming code, but might
 232        be referenced in ARM-era code.  These are stored in a
 233        TREE_LIST; the TREE_VALUE is the actual declaration.  */
 234     tree dead_vars_from_for;
 235
 236     /* STATEMENT_LIST for statements in this binding contour.
 237        Only used at present for SK_CLEANUP temporary bindings.  */
 238     tree statement_list;
 239
 240     /* Binding depth at which this level began.  */
 241     int binding_depth;
 242
 243     /* The kind of scope that this object represents.  However, a
 244        SK_TEMPLATE_SPEC scope is represented with KIND set to
 245        SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true.  */
 246     ENUM_BITFIELD (scope_kind) kind : 4;
 247
 248     /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 249        only valid if KIND == SK_TEMPLATE_PARMS.  */
 250     BOOL_BITFIELD explicit_spec_p : 1;
 251
 252     /* true means make a BLOCK for this level regardless of all else.  */
 253     unsigned keep : 1;
 254
 255     /* Nonzero if this level can safely have additional
 256        cleanup-needing variables added to it.  */
 257     unsigned more_cleanups_ok : 1;
 258     unsigned have_cleanups : 1;
 259
 260     /* 22 bits left to fill a 32-bit word.  */
 261   };
 262
 263 /* The binding level currently in effect.  */
 264
 265 #define current_binding_level                   \
 266   (*(cfun && cp_function_chain->bindings        \
 267    ? &cp_function_chain->bindings               \
 268    : &scope_chain->bindings))
 269
 270 /* The binding level of the current class, if any.  */
 271
 272 #define class_binding_level scope_chain->class_bindings
 273
 274 /* The tree node representing the global scope.  */
 275 extern GTY(()) tree global_namespace;
 276 extern GTY(()) tree global_scope_name;
 277
 278 /* Indicates that there is a type value in some namespace, although
 279    that is not necessarily in scope at the moment.  */
 280
 281 extern GTY(()) tree global_type_node;
 282
 283 /* True if SCOPE designates the global scope binding contour.  */
 284 #define global_scope_p(SCOPE) \
 285   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 286
 287 extern cxx_scope *leave_scope (void);
 288 extern bool kept_level_p (void);
 289 extern int global_bindings_p (void);
 290 extern bool toplevel_bindings_p (void);
 291 extern bool namespace_bindings_p (void);
 292 extern bool template_parm_scope_p (void);
 293 extern scope_kind innermost_scope_kind (void);
 294 extern cxx_scope *begin_scope (scope_kind, tree);
 295 extern void print_binding_stack (void);
 296 extern void print_binding_level (cxx_scope *);
 297 extern void push_to_top_level (void);
 298 extern void pop_from_top_level (void);
 299 extern void pop_everything (void);
 300 extern void keep_next_level (bool);
 301 extern bool is_ancestor (tree, tree);
 302 extern tree push_scope (tree);
 303 extern void pop_scope (tree);
 304 extern tree push_inner_scope (tree);
 305 extern void pop_inner_scope (tree, tree);
 306 extern void push_binding_level (struct cp_binding_level *);
 307 \f
 308 extern void push_namespace (tree);
 309 extern void pop_namespace (void);
 310 extern void push_nested_namespace (tree);
 311 extern void pop_nested_namespace (tree);
 312 extern void pushlevel_class (void);
 313 extern void poplevel_class (void);
 314 extern tree pushdecl_with_scope (tree, cxx_scope *);
 315 extern tree lookup_name (tree, int);
 316 extern tree lookup_name_real (tree, int, int, bool, int, int);
 317 extern tree lookup_type_scope (tree, tag_scope);
 318 extern tree namespace_binding (tree, tree);
 319 extern void set_namespace_binding (tree, tree, tree);
 320 extern tree lookup_namespace_name (tree, tree);
 321 extern tree lookup_qualified_name (tree, tree, bool, bool);
 322 extern tree lookup_name_nonclass (tree);
 323 extern tree lookup_function_nonclass (tree, tree, bool);
 324 extern void push_local_binding (tree, tree, int);
 325 extern bool pushdecl_class_level (tree);
 326 extern tree pushdecl_namespace_level (tree);
 327 extern bool push_class_level_binding (tree, tree);
 328 extern tree getdecls (void);
 329 extern tree cp_namespace_decls (tree);
 330 extern void set_decl_namespace (tree, tree, bool);
 331 extern tree current_decl_namespace (void);
 332 extern void push_decl_namespace (tree);
 333 extern void pop_decl_namespace (void);
 334 extern void do_namespace_alias (tree, tree);
 335 extern void do_toplevel_using_decl (tree, tree, tree);
 336 extern void do_local_using_decl (tree, tree, tree);
 337 extern tree do_class_using_decl (tree, tree);
 338 extern void do_using_directive (tree);
 339 extern tree lookup_arg_dependent (tree, tree, tree);
 340 extern bool is_associated_namespace (tree, tree);
 341 extern void parse_using_directive (tree, tree);
 342 extern tree innermost_non_namespace_value (tree);
 343 extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
 344
 345 /* Set *DECL to the (non-hidden) declaration for ID at global scope,
 346    if present and return true; otherwise return false.  */
 347
 348 static inline bool
 349 get_global_value_if_present (tree id, tree *decl)
 350 {
 351   tree global_value = namespace_binding (id, global_namespace);
 352   if (global_value)
 353     *decl = global_value;
 354   return global_value != NULL;
 355 }
 356
 357 /* True is the binding of IDENTIFIER at global scope names a type.  */
 358
 359 static inline bool
 360 is_typename_at_global_scope (tree id)
 361 {
 362   tree global_value = namespace_binding (id, global_namespace);
 363
 364   return global_value && TREE_CODE (global_value) == TYPE_DECL;
 365 }
 366
 367 #endif /* GCC_CP_NAME_LOOKUP_H */