gcc/cp/name-lookup.h

   1 /* Declarations for C++ name lookup routines.
   2    Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009
   3    Free Software Foundation, Inc.
   4    Contributed by Gabriel Dos Reis <gdr@integrable-solutions.net>
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  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 GTY(()) binding_entry_s {
  36   binding_entry chain;
  37   tree name;
  38   tree type;
  39 };
  40
  41 /* These macros indicate the initial chains count for binding_table.  */
  42 #define SCOPE_DEFAULT_HT_SIZE           (1 << 3)
  43 #define CLASS_SCOPE_HT_SIZE             (1 << 3)
  44 #define NAMESPACE_ORDINARY_HT_SIZE      (1 << 5)
  45 #define NAMESPACE_STD_HT_SIZE           (1 << 8)
  46 #define GLOBAL_SCOPE_HT_SIZE            (1 << 8)
  47
  48 extern void binding_table_foreach (binding_table, bt_foreach_proc, void *);
  49 extern binding_entry binding_table_find (binding_table, tree);
  50 \f
  51 /* Datatype that represents binding established by a declaration between
  52    a name and a C++ entity.  */
  53 typedef struct cxx_binding cxx_binding;
  54
  55 /* The datatype used to implement C++ scope.  */
  56 typedef struct cp_binding_level cxx_scope;
  57
  58 /* Nonzero if this binding is for a local scope, as opposed to a class
  59    or namespace scope.  */
  60 #define LOCAL_BINDING_P(NODE) ((NODE)->is_local)
  61
  62 /* True if NODE->value is from a base class of the class which is
  63    currently being defined.  */
  64 #define INHERITED_VALUE_BINDING_P(NODE) ((NODE)->value_is_inherited)
  65
  66 struct GTY(()) cxx_binding {
  67   /* Link to chain together various bindings for this name.  */
  68   cxx_binding *previous;
  69   /* The non-type entity this name is bound to.  */
  70   tree value;
  71   /* The type entity this name is bound to.  */
  72   tree type;
  73   /* The scope at which this binding was made.  */
  74   cxx_scope *scope;
  75   unsigned value_is_inherited : 1;
  76   unsigned is_local : 1;
  77 };
  78
  79 /* Datatype used to temporarily save C++ bindings (for implicit
  80    instantiations purposes and like).  Implemented in decl.c.  */
  81 typedef struct GTY(()) cxx_saved_binding {
  82   /* The name of the current binding.  */
  83   tree identifier;
  84   /* The binding we're saving.  */
  85   cxx_binding *binding;
  86   tree real_type_value;
  87 } cxx_saved_binding;
  88
  89 DEF_VEC_O(cxx_saved_binding);
  90 DEF_VEC_ALLOC_O(cxx_saved_binding,gc);
  91
  92 extern tree identifier_type_value (tree);
  93 extern void set_identifier_type_value (tree, tree);
  94 extern void pop_binding (tree, tree);
  95 extern tree constructor_name (tree);
  96 extern bool constructor_name_p (tree, tree);
  97 \f
  98 /* The kinds of scopes we recognize.  */
  99 typedef enum scope_kind {
 100   sk_block = 0,      /* An ordinary block scope.  This enumerator must
 101                         have the value zero because "cp_binding_level"
 102                         is initialized by using "memset" to set the
 103                         contents to zero, and the default scope kind
 104                         is "sk_block".  */
 105   sk_cleanup,        /* A scope for (pseudo-)scope for cleanup.  It is
 106                         pseudo in that it is transparent to name lookup
 107                         activities.  */
 108   sk_try,            /* A try-block.  */
 109   sk_catch,          /* A catch-block.  */
 110   sk_for,            /* The scope of the variable declared in a
 111                         for-init-statement.  */
 112   sk_function_parms, /* The scope containing function parameters.  */
 113   sk_class,          /* The scope containing the members of a class.  */
 114   sk_scoped_enum,    /* The scope containing the enumertors of a C++0x
 115                         scoped enumeration.  */
 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   sk_omp             /* An OpenMP structured block.  */
 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 GTY(()) cp_class_binding {
 143   cxx_binding base;
 144   /* The bound name.  */
 145   tree identifier;
 146 } cp_class_binding;
 147
 148 DEF_VEC_O(cp_class_binding);
 149 DEF_VEC_ALLOC_O(cp_class_binding,gc);
 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 GTY(()) cp_binding_level {
 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     VEC(tree,gc) *static_decls;
 190
 191     /* A list of USING_DECL nodes.  */
 192     tree usings;
 193
 194     /* A list of used namespaces. PURPOSE is the namespace,
 195        VALUE the common ancestor with this binding_level's namespace.  */
 196     tree using_directives;
 197
 198     /* For the binding level corresponding to a class, the entities
 199        declared in the class or its base classes.  */
 200     VEC(cp_class_binding,gc) *class_shadowed;
 201
 202     /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 203        is used for all binding levels. The TREE_PURPOSE is the name of
 204        the entity, the TREE_TYPE is the associated type.  In addition
 205        the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
 206        the class.  */
 207     tree type_shadowed;
 208
 209     /* A TREE_LIST.  Each TREE_VALUE is the LABEL_DECL for a local
 210        label in this scope.  The TREE_PURPOSE is the previous value of
 211        the IDENTIFIER_LABEL VALUE.  */
 212     tree shadowed_labels;
 213
 214     /* For each level (except not the global one),
 215        a chain of BLOCK nodes for all the levels
 216        that were entered and exited one level down.  */
 217     tree blocks;
 218
 219     /* The entity (namespace, class, function) the scope of which this
 220        binding contour corresponds to.  Otherwise NULL.  */
 221     tree this_entity;
 222
 223     /* The binding level which this one is contained in (inherits from).  */
 224     struct cp_binding_level *level_chain;
 225
 226     /* List of VAR_DECLS saved from a previous for statement.
 227        These would be dead in ISO-conforming code, but might
 228        be referenced in ARM-era code.  These are stored in a
 229        TREE_LIST; the TREE_VALUE is the actual declaration.  */
 230     tree dead_vars_from_for;
 231
 232     /* STATEMENT_LIST for statements in this binding contour.
 233        Only used at present for SK_CLEANUP temporary bindings.  */
 234     tree statement_list;
 235
 236     /* Binding depth at which this level began.  */
 237     int binding_depth;
 238
 239     /* The kind of scope that this object represents.  However, a
 240        SK_TEMPLATE_SPEC scope is represented with KIND set to
 241        SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true.  */
 242     ENUM_BITFIELD (scope_kind) kind : 4;
 243
 244     /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 245        only valid if KIND == SK_TEMPLATE_PARMS.  */
 246     BOOL_BITFIELD explicit_spec_p : 1;
 247
 248     /* true means make a BLOCK for this level regardless of all else.  */
 249     unsigned keep : 1;
 250
 251     /* Nonzero if this level can safely have additional
 252        cleanup-needing variables added to it.  */
 253     unsigned more_cleanups_ok : 1;
 254     unsigned have_cleanups : 1;
 255
 256     /* 24 bits left to fill a 32-bit word.  */
 257   };
 258
 259 /* The binding level currently in effect.  */
 260
 261 #define current_binding_level                   \
 262   (*(cfun && cp_function_chain->bindings        \
 263    ? &cp_function_chain->bindings               \
 264    : &scope_chain->bindings))
 265
 266 /* The binding level of the current class, if any.  */
 267
 268 #define class_binding_level scope_chain->class_bindings
 269
 270 /* The tree node representing the global scope.  */
 271 extern GTY(()) tree global_namespace;
 272 extern GTY(()) tree global_scope_name;
 273
 274 /* Indicates that there is a type value in some namespace, although
 275    that is not necessarily in scope at the moment.  */
 276
 277 extern GTY(()) tree global_type_node;
 278
 279 /* True if SCOPE designates the global scope binding contour.  */
 280 #define global_scope_p(SCOPE) \
 281   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 282
 283 extern cxx_scope *leave_scope (void);
 284 extern bool kept_level_p (void);
 285 extern int global_bindings_p (void);
 286 extern bool toplevel_bindings_p (void);
 287 extern bool namespace_bindings_p (void);
 288 extern bool template_parm_scope_p (void);
 289 extern scope_kind innermost_scope_kind (void);
 290 extern cxx_scope *begin_scope (scope_kind, tree);
 291 extern void print_binding_stack (void);
 292 extern void push_to_top_level (void);
 293 extern void pop_from_top_level (void);
 294 extern void pop_everything (void);
 295 extern void keep_next_level (bool);
 296 extern bool is_ancestor (tree, tree);
 297 extern tree push_scope (tree);
 298 extern void pop_scope (tree);
 299 extern tree push_inner_scope (tree);
 300 extern void pop_inner_scope (tree, tree);
 301 extern void push_binding_level (struct cp_binding_level *);
 302 \f
 303 extern void push_namespace (tree);
 304 extern void pop_namespace (void);
 305 extern void push_nested_namespace (tree);
 306 extern void pop_nested_namespace (tree);
 307 extern bool handle_namespace_attrs (tree, tree);
 308 extern void pushlevel_class (void);
 309 extern void poplevel_class (void);
 310 extern tree pushdecl_with_scope (tree, cxx_scope *, bool);
 311 extern tree lookup_name_prefer_type (tree, int);
 312 extern tree lookup_name_real (tree, int, int, bool, int, int);
 313 extern tree lookup_type_scope (tree, tag_scope);
 314 extern tree namespace_binding (tree, tree);
 315 extern void set_namespace_binding (tree, tree, tree);
 316 extern bool hidden_name_p (tree);
 317 extern tree remove_hidden_names (tree);
 318 extern tree lookup_qualified_name (tree, tree, bool, bool);
 319 extern tree lookup_name_nonclass (tree);
 320 extern tree lookup_name_innermost_nonclass_level (tree);
 321 extern tree lookup_function_nonclass (tree, VEC(tree,gc) *, bool);
 322 extern void push_local_binding (tree, tree, int);
 323 extern bool pushdecl_class_level (tree);
 324 extern tree pushdecl_namespace_level (tree, bool);
 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, VEC(tree,gc) *);
 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 extern void cp_emit_debug_info_for_using (tree, tree);
 342
 343 /* Set *DECL to the (non-hidden) declaration for ID at global scope,
 344    if present and return true; otherwise return false.  */
 345
 346 static inline bool
 347 get_global_value_if_present (tree id, tree *decl)
 348 {
 349   tree global_value = namespace_binding (id, global_namespace);
 350   if (global_value)
 351     *decl = global_value;
 352   return global_value != NULL;
 353 }
 354
 355 /* True is the binding of IDENTIFIER at global scope names a type.  */
 356
 357 static inline bool
 358 is_typename_at_global_scope (tree id)
 359 {
 360   tree global_value = namespace_binding (id, global_namespace);
 361
 362   return global_value && TREE_CODE (global_value) == TYPE_DECL;
 363 }
 364
 365 #endif /* GCC_CP_NAME_LOOKUP_H */