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-family/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 typedef struct GTY(()) cp_label_binding {
 152   /* The bound LABEL_DECL.  */
 153   tree label;
 154   /* The previous IDENTIFIER_LABEL_VALUE.  */
 155   tree prev_value;
 156 } cp_label_binding;
 157
 158 DEF_VEC_O(cp_label_binding);
 159 DEF_VEC_ALLOC_O(cp_label_binding,gc);
 160
 161 /* For each binding contour we allocate a binding_level structure
 162    which records the names defined in that contour.
 163    Contours include:
 164     0) the global one
 165     1) one for each function definition,
 166        where internal declarations of the parameters appear.
 167     2) one for each compound statement,
 168        to record its declarations.
 169
 170    The current meaning of a name can be found by searching the levels
 171    from the current one out to the global one.
 172
 173    Off to the side, may be the class_binding_level.  This exists only
 174    to catch class-local declarations.  It is otherwise nonexistent.
 175
 176    Also there may be binding levels that catch cleanups that must be
 177    run when exceptions occur.  Thus, to see whether a name is bound in
 178    the current scope, it is not enough to look in the
 179    CURRENT_BINDING_LEVEL.  You should use lookup_name_current_level
 180    instead.  */
 181
 182 /* Note that the information in the `names' component of the global contour
 183    is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers.  */
 184
 185 struct GTY(()) cp_binding_level {
 186     /* A chain of _DECL nodes for all variables, constants, functions,
 187        and typedef types.  These are in the reverse of the order
 188        supplied.  There may be OVERLOADs on this list, too, but they
 189        are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 190     tree names;
 191
 192     /* Count of elements in names chain.  */
 193     size_t names_size;
 194
 195     /* A chain of NAMESPACE_DECL nodes.  */
 196     tree namespaces;
 197
 198     /* An array of static functions and variables (for namespaces only) */
 199     VEC(tree,gc) *static_decls;
 200
 201     /* A list of USING_DECL nodes.  */
 202     tree usings;
 203
 204     /* A list of used namespaces. PURPOSE is the namespace,
 205        VALUE the common ancestor with this binding_level's namespace.  */
 206     tree using_directives;
 207
 208     /* For the binding level corresponding to a class, the entities
 209        declared in the class or its base classes.  */
 210     VEC(cp_class_binding,gc) *class_shadowed;
 211
 212     /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 213        is used for all binding levels. The TREE_PURPOSE is the name of
 214        the entity, the TREE_TYPE is the associated type.  In addition
 215        the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
 216        the class.  */
 217     tree type_shadowed;
 218
 219     /* Similar to class_shadowed, but for IDENTIFIER_LABEL_VALUE, and
 220        used for all binding levels.  */
 221     VEC(cp_label_binding,gc) *shadowed_labels;
 222
 223     /* For each level (except not the global one),
 224        a chain of BLOCK nodes for all the levels
 225        that were entered and exited one level down.  */
 226     tree blocks;
 227
 228     /* The entity (namespace, class, function) the scope of which this
 229        binding contour corresponds to.  Otherwise NULL.  */
 230     tree this_entity;
 231
 232     /* The binding level which this one is contained in (inherits from).  */
 233     struct cp_binding_level *level_chain;
 234
 235     /* List of VAR_DECLS saved from a previous for statement.
 236        These would be dead in ISO-conforming code, but might
 237        be referenced in ARM-era code.  */
 238     VEC(tree,gc) *dead_vars_from_for;
 239
 240     /* STATEMENT_LIST for statements in this binding contour.
 241        Only used at present for SK_CLEANUP temporary bindings.  */
 242     tree statement_list;
 243
 244     /* Binding depth at which this level began.  */
 245     int binding_depth;
 246
 247     /* The kind of scope that this object represents.  However, a
 248        SK_TEMPLATE_SPEC scope is represented with KIND set to
 249        SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true.  */
 250     ENUM_BITFIELD (scope_kind) kind : 4;
 251
 252     /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 253        only valid if KIND == SK_TEMPLATE_PARMS.  */
 254     BOOL_BITFIELD explicit_spec_p : 1;
 255
 256     /* true means make a BLOCK for this level regardless of all else.  */
 257     unsigned keep : 1;
 258
 259     /* Nonzero if this level can safely have additional
 260        cleanup-needing variables added to it.  */
 261     unsigned more_cleanups_ok : 1;
 262     unsigned have_cleanups : 1;
 263
 264     /* 24 bits left to fill a 32-bit word.  */
 265   };
 266
 267 /* The binding level currently in effect.  */
 268
 269 #define current_binding_level                   \
 270   (*(cfun && cp_function_chain && cp_function_chain->bindings \
 271    ? &cp_function_chain->bindings               \
 272    : &scope_chain->bindings))
 273
 274 /* The binding level of the current class, if any.  */
 275
 276 #define class_binding_level scope_chain->class_bindings
 277
 278 /* The tree node representing the global scope.  */
 279 extern GTY(()) tree global_namespace;
 280 extern GTY(()) tree global_scope_name;
 281
 282 /* Indicates that there is a type value in some namespace, although
 283    that is not necessarily in scope at the moment.  */
 284
 285 extern GTY(()) tree global_type_node;
 286
 287 /* True if SCOPE designates the global scope binding contour.  */
 288 #define global_scope_p(SCOPE) \
 289   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 290
 291 extern cxx_scope *leave_scope (void);
 292 extern bool kept_level_p (void);
 293 extern int global_bindings_p (void);
 294 extern bool toplevel_bindings_p (void);
 295 extern bool namespace_bindings_p (void);
 296 extern bool template_parm_scope_p (void);
 297 extern scope_kind innermost_scope_kind (void);
 298 extern cxx_scope *begin_scope (scope_kind, tree);
 299 extern void print_binding_stack (void);
 300 extern void push_to_top_level (void);
 301 extern void pop_from_top_level (void);
 302 extern void pop_everything (void);
 303 extern void keep_next_level (bool);
 304 extern bool is_ancestor (tree, tree);
 305 extern tree push_scope (tree);
 306 extern void pop_scope (tree);
 307 extern tree push_inner_scope (tree);
 308 extern void pop_inner_scope (tree, tree);
 309 extern void push_binding_level (struct cp_binding_level *);
 310 \f
 311 extern void push_namespace (tree);
 312 extern void pop_namespace (void);
 313 extern void push_nested_namespace (tree);
 314 extern void pop_nested_namespace (tree);
 315 extern bool handle_namespace_attrs (tree, tree);
 316 extern void pushlevel_class (void);
 317 extern void poplevel_class (void);
 318 extern tree pushdecl_with_scope (tree, cxx_scope *, bool);
 319 extern tree lookup_name_prefer_type (tree, int);
 320 extern tree lookup_name_real (tree, int, int, bool, int, int);
 321 extern tree lookup_type_scope (tree, tag_scope);
 322 extern tree namespace_binding (tree, tree);
 323 extern void set_namespace_binding (tree, tree, tree);
 324 extern bool hidden_name_p (tree);
 325 extern tree remove_hidden_names (tree);
 326 extern tree lookup_qualified_name (tree, tree, bool, bool);
 327 extern tree lookup_name_nonclass (tree);
 328 extern tree lookup_name_innermost_nonclass_level (tree);
 329 extern bool is_local_extern (tree);
 330 extern tree lookup_function_nonclass (tree, VEC(tree,gc) *, bool);
 331 extern void push_local_binding (tree, tree, int);
 332 extern bool pushdecl_class_level (tree);
 333 extern tree pushdecl_namespace_level (tree, bool);
 334 extern bool push_class_level_binding (tree, tree);
 335 extern tree getdecls (void);
 336 extern tree cp_namespace_decls (tree);
 337 extern void set_decl_namespace (tree, tree, bool);
 338 extern void push_decl_namespace (tree);
 339 extern void pop_decl_namespace (void);
 340 extern void do_namespace_alias (tree, tree);
 341 extern void do_toplevel_using_decl (tree, tree, tree);
 342 extern void do_local_using_decl (tree, tree, tree);
 343 extern tree do_class_using_decl (tree, tree);
 344 extern void do_using_directive (tree);
 345 extern tree lookup_arg_dependent (tree, tree, VEC(tree,gc) *, bool);
 346 extern bool is_associated_namespace (tree, tree);
 347 extern void parse_using_directive (tree, tree);
 348 extern tree innermost_non_namespace_value (tree);
 349 extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
 350 extern void cp_emit_debug_info_for_using (tree, tree);
 351
 352 /* Set *DECL to the (non-hidden) declaration for ID at global scope,
 353    if present and return true; otherwise return false.  */
 354
 355 static inline bool
 356 get_global_value_if_present (tree id, tree *decl)
 357 {
 358   tree global_value = namespace_binding (id, global_namespace);
 359   if (global_value)
 360     *decl = global_value;
 361   return global_value != NULL;
 362 }
 363
 364 /* True is the binding of IDENTIFIER at global scope names a type.  */
 365
 366 static inline bool
 367 is_typename_at_global_scope (tree id)
 368 {
 369   tree global_value = namespace_binding (id, global_namespace);
 370
 371   return global_value && TREE_CODE (global_value) == TYPE_DECL;
 372 }
 373
 374 #endif /* GCC_CP_NAME_LOOKUP_H */