gcc/cp/name-lookup.h

   1 /* Declarations for C++ name lookup routines.
   2    Copyright (C) 2003, 2004, 2005, 2007, 2008  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 3, 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 COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef GCC_CP_NAME_LOOKUP_H
  22 #define GCC_CP_NAME_LOOKUP_H
  23
  24 #include "c-common.h"
  25
  26 /* The type of dictionary used to map names to types declared at
  27    a given scope.  */
  28 typedef struct binding_table_s *binding_table;
  29 typedef struct binding_entry_s *binding_entry;
  30
  31 /* The type of a routine repeatedly called by binding_table_foreach.  */
  32 typedef void (*bt_foreach_proc) (binding_entry, void *);
  33
  34 struct GTY(()) binding_entry_s {
  35   binding_entry chain;
  36   tree name;
  37   tree type;
  38 };
  39
  40 /* These macros indicate the initial chains count for binding_table.  */
  41 #define SCOPE_DEFAULT_HT_SIZE           (1 << 3)
  42 #define CLASS_SCOPE_HT_SIZE             (1 << 3)
  43 #define NAMESPACE_ORDINARY_HT_SIZE      (1 << 5)
  44 #define NAMESPACE_STD_HT_SIZE           (1 << 8)
  45 #define GLOBAL_SCOPE_HT_SIZE            (1 << 8)
  46
  47 extern void binding_table_foreach (binding_table, bt_foreach_proc, void *);
  48 extern binding_entry binding_table_find (binding_table, tree);
  49 \f
  50 /* Datatype that represents binding established by a declaration between
  51    a name and a C++ entity.  */
  52 typedef struct cxx_binding cxx_binding;
  53
  54 /* The datatype used to implement C++ scope.  */
  55 typedef struct cp_binding_level cxx_scope;
  56
  57 /* Nonzero if this binding is for a local scope, as opposed to a class
  58    or namespace scope.  */
  59 #define LOCAL_BINDING_P(NODE) ((NODE)->is_local)
  60
  61 /* True if NODE->value is from a base class of the class which is
  62    currently being defined.  */
  63 #define INHERITED_VALUE_BINDING_P(NODE) ((NODE)->value_is_inherited)
  64
  65 struct GTY(()) cxx_binding {
  66   /* Link to chain together various bindings for this name.  */
  67   cxx_binding *previous;
  68   /* The non-type entity this name is bound to.  */
  69   tree value;
  70   /* The type entity this name is bound to.  */
  71   tree type;
  72   /* The scope at which this binding was made.  */
  73   cxx_scope *scope;
  74   unsigned value_is_inherited : 1;
  75   unsigned is_local : 1;
  76 };
  77
  78 /* Datatype used to temporarily save C++ bindings (for implicit
  79    instantiations purposes and like).  Implemented in decl.c.  */
  80 typedef struct GTY(()) cxx_saved_binding {
  81   /* The name of the current binding.  */
  82   tree identifier;
  83   /* The binding we're saving.  */
  84   cxx_binding *binding;
  85   tree real_type_value;
  86 } cxx_saved_binding;
  87
  88 DEF_VEC_O(cxx_saved_binding);
  89 DEF_VEC_ALLOC_O(cxx_saved_binding,gc);
  90
  91 extern tree identifier_type_value (tree);
  92 extern void set_identifier_type_value (tree, tree);
  93 extern void pop_binding (tree, tree);
  94 extern tree constructor_name (tree);
  95 extern bool constructor_name_p (tree, tree);
  96 \f
  97 /* The kinds of scopes we recognize.  */
  98 typedef enum scope_kind {
  99   sk_block = 0,      /* An ordinary block scope.  This enumerator must
 100                         have the value zero because "cp_binding_level"
 101                         is initialized by using "memset" to set the
 102                         contents to zero, and the default scope kind
 103                         is "sk_block".  */
 104   sk_cleanup,        /* A scope for (pseudo-)scope for cleanup.  It is
 105                         pseudo in that it is transparent to name lookup
 106                         activities.  */
 107   sk_try,            /* A try-block.  */
 108   sk_catch,          /* A catch-block.  */
 109   sk_for,            /* The scope of the variable declared in a
 110                         for-init-statement.  */
 111   sk_function_parms, /* The scope containing function parameters.  */
 112   sk_class,          /* The scope containing the members of a class.  */
 113   sk_scoped_enum,    /* The scope containing the enumertors of a C++0x
 114                         scoped enumeration.  */
 115   sk_namespace,      /* The scope containing the members of a
 116                         namespace, including the global scope.  */
 117   sk_template_parms, /* A scope for template parameters.  */
 118   sk_template_spec,  /* Like sk_template_parms, but for an explicit
 119                         specialization.  Since, by definition, an
 120                         explicit specialization is introduced by
 121                         "template <>", this scope is always empty.  */
 122   sk_omp             /* An OpenMP structured block.  */
 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 GTY(()) cp_class_binding {
 142   cxx_binding base;
 143   /* The bound name.  */
 144   tree identifier;
 145 } cp_class_binding;
 146
 147 DEF_VEC_O(cp_class_binding);
 148 DEF_VEC_ALLOC_O(cp_class_binding,gc);
 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 GTY(()) cp_binding_level {
 175     /* A chain of _DECL nodes for all variables, constants, functions,
 176        and typedef types.  These are in the reverse of the order
 177        supplied.  There may be OVERLOADs on this list, too, but they
 178        are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 179     tree names;
 180
 181     /* Count of elements in names chain.  */
 182     size_t names_size;
 183
 184     /* A chain of NAMESPACE_DECL nodes.  */
 185     tree namespaces;
 186
 187     /* An array of static functions and variables (for namespaces only) */
 188     VEC(tree,gc) *static_decls;
 189
 190     /* A list of USING_DECL nodes.  */
 191     tree usings;
 192
 193     /* A list of used namespaces. PURPOSE is the namespace,
 194        VALUE the common ancestor with this binding_level's namespace.  */
 195     tree using_directives;
 196
 197     /* For the binding level corresponding to a class, the entities
 198        declared in the class or its base classes.  */
 199     VEC(cp_class_binding,gc) *class_shadowed;
 200
 201     /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 202        is used for all binding levels. The TREE_PURPOSE is the name of
 203        the entity, the TREE_TYPE is the associated type.  In addition
 204        the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
 205        the class.  */
 206     tree type_shadowed;
 207
 208     /* A TREE_LIST.  Each TREE_VALUE is the LABEL_DECL for a local
 209        label in this scope.  The TREE_PURPOSE is the previous value of
 210        the IDENTIFIER_LABEL VALUE.  */
 211     tree shadowed_labels;
 212
 213     /* For each level (except not the global one),
 214        a chain of BLOCK nodes for all the levels
 215        that were entered and exited one level down.  */
 216     tree blocks;
 217
 218     /* The entity (namespace, class, function) the scope of which this
 219        binding contour corresponds to.  Otherwise NULL.  */
 220     tree this_entity;
 221
 222     /* The binding level which this one is contained in (inherits from).  */
 223     struct cp_binding_level *level_chain;
 224
 225     /* List of VAR_DECLS saved from a previous for statement.
 226        These would be dead in ISO-conforming code, but might
 227        be referenced in ARM-era code.  These are stored in a
 228        TREE_LIST; the TREE_VALUE is the actual declaration.  */
 229     tree dead_vars_from_for;
 230
 231     /* STATEMENT_LIST for statements in this binding contour.
 232        Only used at present for SK_CLEANUP temporary bindings.  */
 233     tree statement_list;
 234
 235     /* Binding depth at which this level began.  */
 236     int binding_depth;
 237
 238     /* The kind of scope that this object represents.  However, a
 239        SK_TEMPLATE_SPEC scope is represented with KIND set to
 240        SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true.  */
 241     ENUM_BITFIELD (scope_kind) kind : 4;
 242
 243     /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 244        only valid if KIND == SK_TEMPLATE_PARMS.  */
 245     BOOL_BITFIELD explicit_spec_p : 1;
 246
 247     /* true means make a BLOCK for this level regardless of all else.  */
 248     unsigned keep : 1;
 249
 250     /* Nonzero if this level can safely have additional
 251        cleanup-needing variables added to it.  */
 252     unsigned more_cleanups_ok : 1;
 253     unsigned have_cleanups : 1;
 254
 255     /* 24 bits left to fill a 32-bit word.  */
 256   };
 257
 258 /* The binding level currently in effect.  */
 259
 260 #define current_binding_level                   \
 261   (*(cfun && cp_function_chain->bindings        \
 262    ? &cp_function_chain->bindings               \
 263    : &scope_chain->bindings))
 264
 265 /* The binding level of the current class, if any.  */
 266
 267 #define class_binding_level scope_chain->class_bindings
 268
 269 /* The tree node representing the global scope.  */
 270 extern GTY(()) tree global_namespace;
 271 extern GTY(()) tree global_scope_name;
 272
 273 /* Indicates that there is a type value in some namespace, although
 274    that is not necessarily in scope at the moment.  */
 275
 276 extern GTY(()) tree global_type_node;
 277
 278 /* True if SCOPE designates the global scope binding contour.  */
 279 #define global_scope_p(SCOPE) \
 280   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 281
 282 extern cxx_scope *leave_scope (void);
 283 extern bool kept_level_p (void);
 284 extern int global_bindings_p (void);
 285 extern bool toplevel_bindings_p (void);
 286 extern bool namespace_bindings_p (void);
 287 extern bool template_parm_scope_p (void);
 288 extern scope_kind innermost_scope_kind (void);
 289 extern cxx_scope *begin_scope (scope_kind, tree);
 290 extern void print_binding_stack (void);
 291 extern void push_to_top_level (void);
 292 extern void pop_from_top_level (void);
 293 extern void pop_everything (void);
 294 extern void keep_next_level (bool);
 295 extern bool is_ancestor (tree, tree);
 296 extern tree push_scope (tree);
 297 extern void pop_scope (tree);
 298 extern tree push_inner_scope (tree);
 299 extern void pop_inner_scope (tree, tree);
 300 extern void push_binding_level (struct cp_binding_level *);
 301 \f
 302 extern void push_namespace (tree);
 303 extern void pop_namespace (void);
 304 extern void push_nested_namespace (tree);
 305 extern void pop_nested_namespace (tree);
 306 extern bool handle_namespace_attrs (tree, tree);
 307 extern void pushlevel_class (void);
 308 extern void poplevel_class (void);
 309 extern tree pushdecl_with_scope (tree, cxx_scope *, bool);
 310 extern tree lookup_name_prefer_type (tree, int);
 311 extern tree lookup_name_real (tree, int, int, bool, int, int);
 312 extern tree lookup_type_scope (tree, tag_scope);
 313 extern tree namespace_binding (tree, tree);
 314 extern void set_namespace_binding (tree, tree, tree);
 315 extern bool hidden_name_p (tree);
 316 extern tree remove_hidden_names (tree);
 317 extern tree lookup_qualified_name (tree, tree, bool, bool);
 318 extern tree lookup_name_nonclass (tree);
 319 extern tree lookup_name_innermost_nonclass_level (tree);
 320 extern tree lookup_function_nonclass (tree, tree, bool);
 321 extern void push_local_binding (tree, tree, int);
 322 extern bool pushdecl_class_level (tree);
 323 extern tree pushdecl_namespace_level (tree, bool);
 324 extern bool push_class_level_binding (tree, tree);
 325 extern tree getdecls (void);
 326 extern tree cp_namespace_decls (tree);
 327 extern void set_decl_namespace (tree, tree, bool);
 328 extern void push_decl_namespace (tree);
 329 extern void pop_decl_namespace (void);
 330 extern void do_namespace_alias (tree, tree);
 331 extern void do_toplevel_using_decl (tree, tree, tree);
 332 extern void do_local_using_decl (tree, tree, tree);
 333 extern tree do_class_using_decl (tree, tree);
 334 extern void do_using_directive (tree);
 335 extern tree lookup_arg_dependent (tree, tree, tree);
 336 extern bool is_associated_namespace (tree, tree);
 337 extern void parse_using_directive (tree, tree);
 338 extern tree innermost_non_namespace_value (tree);
 339 extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
 340 extern void cp_emit_debug_info_for_using (tree, tree);
 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 */