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, 51 Franklin Street, Fifth Floor,
  20 Boston, MA 02110-1301, 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_O(cxx_saved_binding);
  93 DEF_VEC_ALLOC_O(cxx_saved_binding,gc);
  94
  95 extern tree identifier_type_value (tree);
  96 extern void set_identifier_type_value (tree, tree);
  97 extern void pop_binding (tree, 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                         pseudo 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   sk_omp             /* An OpenMP structured block.  */
 125 } scope_kind;
 126
 127 /* The scope where the class/struct/union/enum tag applies.  */
 128 typedef enum tag_scope {
 129   ts_current = 0,       /* Current scope only.  This is for the
 130                              class-key identifier;
 131                            case mentioned in [basic.lookup.elab]/2,
 132                            or the class/enum definition
 133                              class-key identifier { ... };  */
 134   ts_global = 1,        /* All scopes.  This is the 3.4.1
 135                            [basic.lookup.unqual] lookup mentioned
 136                            in [basic.lookup.elab]/2.  */
 137   ts_within_enclosing_non_class = 2     /* Search within enclosing non-class
 138                                            only, for friend class lookup
 139                                            according to [namespace.memdef]/3
 140                                            and [class.friend]/9.  */
 141 } tag_scope;
 142
 143 typedef struct cp_class_binding GTY(())
 144 {
 145   cxx_binding base;
 146   /* The bound name.  */
 147   tree identifier;
 148 } cp_class_binding;
 149
 150 DEF_VEC_O(cp_class_binding);
 151 DEF_VEC_ALLOC_O(cp_class_binding,gc);
 152
 153 /* For each binding contour we allocate a binding_level structure
 154    which records the names defined in that contour.
 155    Contours include:
 156     0) the global one
 157     1) one for each function definition,
 158        where internal declarations of the parameters appear.
 159     2) one for each compound statement,
 160        to record its declarations.
 161
 162    The current meaning of a name can be found by searching the levels
 163    from the current one out to the global one.
 164
 165    Off to the side, may be the class_binding_level.  This exists only
 166    to catch class-local declarations.  It is otherwise nonexistent.
 167
 168    Also there may be binding levels that catch cleanups that must be
 169    run when exceptions occur.  Thus, to see whether a name is bound in
 170    the current scope, it is not enough to look in the
 171    CURRENT_BINDING_LEVEL.  You should use lookup_name_current_level
 172    instead.  */
 173
 174 /* Note that the information in the `names' component of the global contour
 175    is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers.  */
 176
 177 struct cp_binding_level GTY(())
 178   {
 179     /* A chain of _DECL nodes for all variables, constants, functions,
 180        and typedef types.  These are in the reverse of the order
 181        supplied.  There may be OVERLOADs on this list, too, but they
 182        are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 183     tree names;
 184
 185     /* Count of elements in names chain.  */
 186     size_t names_size;
 187
 188     /* A chain of NAMESPACE_DECL nodes.  */
 189     tree namespaces;
 190
 191     /* An array of static functions and variables (for namespaces only) */
 192     VEC(tree,gc) *static_decls;
 193
 194     /* A chain of VTABLE_DECL nodes.  */
 195     tree vtables;
 196
 197     /* A list of USING_DECL nodes.  */
 198     tree usings;
 199
 200     /* A list of used namespaces. PURPOSE is the namespace,
 201        VALUE the common ancestor with this binding_level's namespace.  */
 202     tree using_directives;
 203
 204     /* For the binding level corresponding to a class, the entities
 205        declared in the class or its base classes.  */
 206     VEC(cp_class_binding,gc) *class_shadowed;
 207
 208     /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 209        is used for all binding levels. The TREE_PURPOSE is the name of
 210        the entity, the TREE_TYPE is the associated type.  In addition
 211        the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
 212        the class.  */
 213     tree type_shadowed;
 214
 215     /* A TREE_LIST.  Each TREE_VALUE is the LABEL_DECL for a local
 216        label in this scope.  The TREE_PURPOSE is the previous value of
 217        the IDENTIFIER_LABEL VALUE.  */
 218     tree shadowed_labels;
 219
 220     /* For each level (except not the global one),
 221        a chain of BLOCK nodes for all the levels
 222        that were entered and exited one level down.  */
 223     tree blocks;
 224
 225     /* The entity (namespace, class, function) the scope of which this
 226        binding contour corresponds to.  Otherwise NULL.  */
 227     tree this_entity;
 228
 229     /* The binding level which this one is contained in (inherits from).  */
 230     struct cp_binding_level *level_chain;
 231
 232     /* List of VAR_DECLS saved from a previous for statement.
 233        These would be dead in ISO-conforming code, but might
 234        be referenced in ARM-era code.  These are stored in a
 235        TREE_LIST; the TREE_VALUE is the actual declaration.  */
 236     tree dead_vars_from_for;
 237
 238     /* STATEMENT_LIST for statements in this binding contour.
 239        Only used at present for SK_CLEANUP temporary bindings.  */
 240     tree statement_list;
 241
 242     /* Binding depth at which this level began.  */
 243     int binding_depth;
 244
 245     /* The kind of scope that this object represents.  However, a
 246        SK_TEMPLATE_SPEC scope is represented with KIND set to
 247        SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true.  */
 248     ENUM_BITFIELD (scope_kind) kind : 4;
 249
 250     /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 251        only valid if KIND == SK_TEMPLATE_PARMS.  */
 252     BOOL_BITFIELD explicit_spec_p : 1;
 253
 254     /* true means make a BLOCK for this level regardless of all else.  */
 255     unsigned keep : 1;
 256
 257     /* Nonzero if this level can safely have additional
 258        cleanup-needing variables added to it.  */
 259     unsigned more_cleanups_ok : 1;
 260     unsigned have_cleanups : 1;
 261
 262     /* Nonzero if this level has associated visibility which we should pop
 263        when leaving the scope. */
 264     unsigned has_visibility : 1;
 265
 266     /* 23 bits left to fill a 32-bit word.  */
 267   };
 268
 269 /* The binding level currently in effect.  */
 270
 271 #define current_binding_level                   \
 272   (*(cfun && cp_function_chain->bindings        \
 273    ? &cp_function_chain->bindings               \
 274    : &scope_chain->bindings))
 275
 276 /* The binding level of the current class, if any.  */
 277
 278 #define class_binding_level scope_chain->class_bindings
 279
 280 /* The tree node representing the global scope.  */
 281 extern GTY(()) tree global_namespace;
 282 extern GTY(()) tree global_scope_name;
 283
 284 /* Indicates that there is a type value in some namespace, although
 285    that is not necessarily in scope at the moment.  */
 286
 287 extern GTY(()) tree global_type_node;
 288
 289 /* True if SCOPE designates the global scope binding contour.  */
 290 #define global_scope_p(SCOPE) \
 291   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 292
 293 extern cxx_scope *leave_scope (void);
 294 extern bool kept_level_p (void);
 295 extern int global_bindings_p (void);
 296 extern bool toplevel_bindings_p (void);
 297 extern bool namespace_bindings_p (void);
 298 extern bool template_parm_scope_p (void);
 299 extern scope_kind innermost_scope_kind (void);
 300 extern cxx_scope *begin_scope (scope_kind, tree);
 301 extern void print_binding_stack (void);
 302 extern void push_to_top_level (void);
 303 extern void pop_from_top_level (void);
 304 extern void pop_everything (void);
 305 extern void keep_next_level (bool);
 306 extern bool is_ancestor (tree, tree);
 307 extern tree push_scope (tree);
 308 extern void pop_scope (tree);
 309 extern tree push_inner_scope (tree);
 310 extern void pop_inner_scope (tree, tree);
 311 extern void push_binding_level (struct cp_binding_level *);
 312 \f
 313 extern void push_namespace (tree);
 314 extern void push_namespace_with_attribs (tree, tree);
 315 extern void pop_namespace (void);
 316 extern void push_nested_namespace (tree);
 317 extern void pop_nested_namespace (tree);
 318 extern void pushlevel_class (void);
 319 extern void poplevel_class (void);
 320 extern tree pushdecl_with_scope (tree, cxx_scope *, bool);
 321 extern tree lookup_name_prefer_type (tree, int);
 322 extern tree lookup_name_real (tree, int, int, bool, int, int);
 323 extern tree lookup_type_scope (tree, tag_scope);
 324 extern tree namespace_binding (tree, tree);
 325 extern void set_namespace_binding (tree, tree, tree);
 326 extern bool hidden_name_p (tree);
 327 extern tree remove_hidden_names (tree);
 328 extern tree lookup_qualified_name (tree, tree, bool, bool);
 329 extern tree lookup_name_nonclass (tree);
 330 extern tree lookup_function_nonclass (tree, tree, 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, tree);
 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 */