gcc/cp/name-lookup.h

   1 /* Declarations for C++ name lookup routines.
   2    Copyright (C) 2003, 2004 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_remove_anonymous_types (binding_table);
  50 extern void binding_table_foreach (binding_table, bt_foreach_proc, void *);
  51 extern binding_entry binding_table_find (binding_table, tree);
  52 extern void cxx_remember_type_decls (binding_table);
  53 \f
  54 /* Datatype used to temporarily save C++ bindings (for implicit
  55    instantiations purposes and like).  Implemented in decl.c.  */
  56 typedef struct cxx_saved_binding cxx_saved_binding;
  57
  58 /* Datatype that represents binding established by a declaration between
  59    a name and a C++ entity.  */
  60 typedef struct cxx_binding cxx_binding;
  61
  62 /* The datatype used to implement C++ scope.  */
  63 typedef struct cp_binding_level cxx_scope;
  64
  65 /* Nonzero if this binding is for a local scope, as opposed to a class
  66    or namespace scope.  */
  67 #define LOCAL_BINDING_P(NODE) ((NODE)->is_local)
  68
  69 /* True if NODE->value is from a base class of the class which is
  70    currently being defined.  */
  71 #define INHERITED_VALUE_BINDING_P(NODE) ((NODE)->value_is_inherited)
  72
  73 struct cxx_binding GTY(())
  74 {
  75   /* Link to chain together various bindings for this name.  */
  76   cxx_binding *previous;
  77   /* The non-type entity this name is bound to.  */
  78   tree value;
  79   /* The type entity this name is bound to.  */
  80   tree type;
  81   /* The scope at which this binding was made.  */
  82   cxx_scope *scope;
  83   unsigned value_is_inherited : 1;
  84   unsigned is_local : 1;
  85 };
  86
  87 extern tree identifier_type_value (tree);
  88 extern void set_identifier_type_value (tree, tree);
  89 extern void pop_binding (tree, tree);
  90 extern void clear_identifier_class_values (void);
  91 extern tree constructor_name_full (tree);
  92 extern tree constructor_name (tree);
  93 extern bool constructor_name_p (tree, tree);
  94 \f
  95 /* The kinds of scopes we recognize.  */
  96 typedef enum scope_kind {
  97   sk_block = 0,      /* An ordinary block scope.  This enumerator must
  98                         have the value zero because "cp_binding_level"
  99                         is initialized by using "memset" to set the
 100                         contents to zero, and the default scope kind
 101                         is "sk_block".  */
 102   sk_cleanup,        /* A scope for (pseudo-)scope for cleanup.  It is
 103                         peusdo in that it is transparent to name lookup
 104                         activities.  */
 105   sk_try,            /* A try-block.  */
 106   sk_catch,          /* A catch-block.  */
 107   sk_for,            /* The scope of the variable declared in a
 108                         for-init-statement.  */
 109   sk_function_parms, /* The scope containing function parameters.  */
 110   sk_class,          /* The scope containing the members of a class.  */
 111   sk_namespace,      /* The scope containing the members of a
 112                         namespace, including the global scope.  */
 113   sk_template_parms, /* A scope for template parameters.  */
 114   sk_template_spec   /* Like sk_template_parms, but for an explicit
 115                         specialization.  Since, by definition, an
 116                         explicit specialization is introduced by
 117                         "template <>", this scope is always empty.  */
 118 } scope_kind;
 119
 120 /* For each binding contour we allocate a binding_level structure
 121    which records the names defined in that contour.
 122    Contours include:
 123     0) the global one
 124     1) one for each function definition,
 125        where internal declarations of the parameters appear.
 126     2) one for each compound statement,
 127        to record its declarations.
 128
 129    The current meaning of a name can be found by searching the levels
 130    from the current one out to the global one.
 131
 132    Off to the side, may be the class_binding_level.  This exists only
 133    to catch class-local declarations.  It is otherwise nonexistent.
 134
 135    Also there may be binding levels that catch cleanups that must be
 136    run when exceptions occur.  Thus, to see whether a name is bound in
 137    the current scope, it is not enough to look in the
 138    CURRENT_BINDING_LEVEL.  You should use lookup_name_current_level
 139    instead.  */
 140
 141 /* Note that the information in the `names' component of the global contour
 142    is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers.  */
 143
 144 struct cp_binding_level GTY(())
 145   {
 146     /* A chain of _DECL nodes for all variables, constants, functions,
 147        and typedef types.  These are in the reverse of the order
 148        supplied.  There may be OVERLOADs on this list, too, but they
 149        are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 150     tree names;
 151
 152     /* Count of elements in names chain.  */
 153     size_t names_size;
 154
 155     /* A chain of NAMESPACE_DECL nodes.  */
 156     tree namespaces;
 157
 158     /* An array of static functions and variables (for namespaces only) */
 159     varray_type static_decls;
 160
 161     /* A chain of VTABLE_DECL nodes.  */
 162     tree vtables;
 163
 164     /* A dictionary for looking up user-defined-types.  */
 165     binding_table type_decls;
 166
 167     /* A list of USING_DECL nodes.  */
 168     tree usings;
 169
 170     /* A list of used namespaces. PURPOSE is the namespace,
 171        VALUE the common ancestor with this binding_level's namespace.  */
 172     tree using_directives;
 173
 174     /* If this binding level is the binding level for a class, then
 175        class_shadowed is a TREE_LIST.  The TREE_PURPOSE of each node
 176        is the name of an entity bound in the class.  The TREE_TYPE is
 177        the DECL bound by this name in the class.  */
 178     tree class_shadowed;
 179
 180     /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 181        is used for all binding levels. In addition the TREE_VALUE is the
 182        IDENTIFIER_TYPE_VALUE before we entered the class.  */
 183     tree type_shadowed;
 184
 185     /* A TREE_LIST.  Each TREE_VALUE is the LABEL_DECL for a local
 186        label in this scope.  The TREE_PURPOSE is the previous value of
 187        the IDENTIFIER_LABEL VALUE.  */
 188     tree shadowed_labels;
 189
 190     /* For each level (except not the global one),
 191        a chain of BLOCK nodes for all the levels
 192        that were entered and exited one level down.  */
 193     tree blocks;
 194
 195     /* The entity (namespace, class, function) the scope of which this
 196        binding contour corresponds to.  Otherwise NULL.  */
 197     tree this_entity;
 198
 199     /* The binding level which this one is contained in (inherits from).  */
 200     struct cp_binding_level *level_chain;
 201
 202     /* List of VAR_DECLS saved from a previous for statement.
 203        These would be dead in ISO-conforming code, but might
 204        be referenced in ARM-era code.  These are stored in a
 205        TREE_LIST; the TREE_VALUE is the actual declaration.  */
 206     tree dead_vars_from_for;
 207
 208     /* STATEMENT_LIST for statements in this binding contour.
 209        Only used at present for SK_CLEANUP temporary bindings.  */
 210     tree statement_list;
 211
 212     /* Binding depth at which this level began.  */
 213     int binding_depth;
 214
 215     /* The kind of scope that this object represents.  However, a
 216        SK_TEMPLATE_SPEC scope is represented with KIND set to
 217        SK_TEMPALTE_PARMS and EXPLICIT_SPEC_P set to true.  */
 218     ENUM_BITFIELD (scope_kind) kind : 4;
 219
 220     /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 221        only valid if KIND == SK_TEMPLATE_PARMS.  */
 222     BOOL_BITFIELD explicit_spec_p : 1;
 223
 224     /* true means make a BLOCK for this level regardless of all else.  */
 225     unsigned keep : 1;
 226
 227     /* Nonzero if this level can safely have additional
 228        cleanup-needing variables added to it.  */
 229     unsigned more_cleanups_ok : 1;
 230     unsigned have_cleanups : 1;
 231
 232     /* 22 bits left to fill a 32-bit word.  */
 233   };
 234
 235 /* The binding level currently in effect.  */
 236
 237 #define current_binding_level                   \
 238   (*(cfun && cp_function_chain->bindings        \
 239    ? &cp_function_chain->bindings               \
 240    : &scope_chain->bindings))
 241
 242 /* The binding level of the current class, if any.  */
 243
 244 #define class_binding_level scope_chain->class_bindings
 245
 246 /* The tree node representing the global scope.  */
 247 extern GTY(()) tree global_namespace;
 248 extern GTY(()) tree global_scope_name;
 249
 250 /* Indicates that there is a type value in some namespace, although
 251    that is not necessarily in scope at the moment.  */
 252
 253 extern GTY(()) tree global_type_node;
 254
 255 /* True if SCOPE designates the global scope binding contour.  */
 256 #define global_scope_p(SCOPE) \
 257   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 258
 259 extern cxx_scope *leave_scope (void);
 260 extern bool kept_level_p (void);
 261 extern int global_bindings_p (void);
 262 extern bool toplevel_bindings_p (void);
 263 extern bool namespace_bindings_p (void);
 264 extern bool template_parm_scope_p (void);
 265 extern scope_kind innermost_scope_kind (void);
 266 extern cxx_scope *begin_scope (scope_kind, tree);
 267 extern void print_binding_stack (void);
 268 extern void print_binding_level (cxx_scope *);
 269 extern void push_to_top_level (void);
 270 extern void pop_from_top_level (void);
 271 extern void pop_everything (void);
 272 extern void keep_next_level (bool);
 273 extern bool is_ancestor (tree, tree);
 274 extern bool push_scope (tree);
 275 extern void pop_scope (tree);
 276 \f
 277 extern void push_namespace (tree);
 278 extern void pop_namespace (void);
 279 extern void push_nested_namespace (tree);
 280 extern void pop_nested_namespace (tree);
 281 extern void pushlevel_class (void);
 282 extern void poplevel_class (void);
 283 extern tree pushdecl_with_scope (tree, cxx_scope *);
 284 extern tree lookup_tag (enum tree_code, tree, cxx_scope *, int);
 285 extern tree lookup_tag_reverse (tree, tree);
 286 extern tree lookup_name (tree, int);
 287 extern tree lookup_name_real (tree, int, int, int, int);
 288 extern tree namespace_binding (tree, tree);
 289 extern void set_namespace_binding (tree, tree, tree);
 290 extern tree lookup_namespace_name (tree, tree);
 291 extern tree lookup_qualified_name (tree, tree, bool, bool);
 292 extern tree lookup_name_nonclass (tree);
 293 extern tree lookup_function_nonclass (tree, tree);
 294 extern void push_local_binding (tree, tree, int);
 295 extern int push_class_binding (tree, tree);
 296 extern bool pushdecl_class_level (tree);
 297 extern tree pushdecl_namespace_level (tree);
 298 extern bool push_class_level_binding (tree, tree);
 299 extern void storetags (tree);
 300 extern tree getdecls (void);
 301 extern tree cp_namespace_decls (tree);
 302 extern void set_class_shadows (tree);
 303 extern void set_decl_namespace (tree, tree, bool);
 304 extern tree current_decl_namespace (void);
 305 extern void push_decl_namespace (tree);
 306 extern void pop_decl_namespace (void);
 307 extern void do_namespace_alias (tree, tree);
 308 extern void do_toplevel_using_decl (tree, tree, tree);
 309 extern void do_local_using_decl (tree, tree, tree);
 310 extern tree do_class_using_decl (tree);
 311 extern void do_using_directive (tree);
 312 extern tree lookup_arg_dependent (tree, tree, tree);
 313 extern bool is_associated_namespace (tree, tree);
 314 extern void parse_using_directive (tree, tree);
 315
 316
 317 /* Set *DECL to the (non-hidden) declaration for ID at global scope,
 318    if present and return true; otherwise return false.  */
 319
 320 static inline bool
 321 get_global_value_if_present (tree id, tree *decl)
 322 {
 323   tree global_value = namespace_binding (id, global_namespace);
 324   if (global_value)
 325     *decl = global_value;
 326   return global_value != NULL;
 327 }
 328
 329 /* True is the binding of IDENTIFIER at global scope names a type.  */
 330
 331 static inline bool
 332 is_typename_at_global_scope (tree id)
 333 {
 334   tree global_value = namespace_binding (id, global_namespace);
 335
 336   return global_value && TREE_CODE (global_value) == TYPE_DECL;
 337 }
 338
 339 #endif /* GCC_CP_NAME_LOOKUP_H */