gcc/cp/name-lookup.h

   1 /* Declarations for C++ name lookup routines.
   2    Copyright (C) 2003, 2004, 2005, 2007  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 binding_entry_s GTY(())
  35 {
  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 cxx_binding GTY(())
  67 {
  68   /* Link to chain together various bindings for this name.  */
  69   cxx_binding *previous;
  70   /* The non-type entity this name is bound to.  */
  71   tree value;
  72   /* The type entity this name is bound to.  */
  73   tree type;
  74   /* The scope at which this binding was made.  */
  75   cxx_scope *scope;
  76   unsigned value_is_inherited : 1;
  77   unsigned is_local : 1;
  78 };
  79
  80 /* Datatype used to temporarily save C++ bindings (for implicit
  81    instantiations purposes and like).  Implemented in decl.c.  */
  82 typedef struct cxx_saved_binding GTY(())
  83 {
  84   /* The name of the current binding.  */
  85   tree identifier;
  86   /* The binding we're saving.  */
  87   cxx_binding *binding;
  88   tree real_type_value;
  89 } cxx_saved_binding;
  90
  91 DEF_VEC_O(cxx_saved_binding);
  92 DEF_VEC_ALLOC_O(cxx_saved_binding,gc);
  93
  94 extern tree identifier_type_value (tree);
  95 extern void set_identifier_type_value (tree, tree);
  96 extern void pop_binding (tree, tree);
  97 extern tree constructor_name (tree);
  98 extern bool constructor_name_p (tree, tree);
  99 \f
 100 /* The kinds of scopes we recognize.  */
 101 typedef enum scope_kind {
 102   sk_block = 0,      /* An ordinary block scope.  This enumerator must
 103                         have the value zero because "cp_binding_level"
 104                         is initialized by using "memset" to set the
 105                         contents to zero, and the default scope kind
 106                         is "sk_block".  */
 107   sk_cleanup,        /* A scope for (pseudo-)scope for cleanup.  It is
 108                         pseudo in that it is transparent to name lookup
 109                         activities.  */
 110   sk_try,            /* A try-block.  */
 111   sk_catch,          /* A catch-block.  */
 112   sk_for,            /* The scope of the variable declared in a
 113                         for-init-statement.  */
 114   sk_function_parms, /* The scope containing function parameters.  */
 115   sk_class,          /* The scope containing the members of a class.  */
 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 cp_class_binding GTY(())
 143 {
 144   cxx_binding base;
 145   /* The bound name.  */
 146   tree identifier;
 147 } cp_class_binding;
 148
 149 DEF_VEC_O(cp_class_binding);
 150 DEF_VEC_ALLOC_O(cp_class_binding,gc);
 151
 152 /* For each binding contour we allocate a binding_level structure
 153    which records the names defined in that contour.
 154    Contours include:
 155     0) the global one
 156     1) one for each function definition,
 157        where internal declarations of the parameters appear.
 158     2) one for each compound statement,
 159        to record its declarations.
 160
 161    The current meaning of a name can be found by searching the levels
 162    from the current one out to the global one.
 163
 164    Off to the side, may be the class_binding_level.  This exists only
 165    to catch class-local declarations.  It is otherwise nonexistent.
 166
 167    Also there may be binding levels that catch cleanups that must be
 168    run when exceptions occur.  Thus, to see whether a name is bound in
 169    the current scope, it is not enough to look in the
 170    CURRENT_BINDING_LEVEL.  You should use lookup_name_current_level
 171    instead.  */
 172
 173 /* Note that the information in the `names' component of the global contour
 174    is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers.  */
 175
 176 struct cp_binding_level GTY(())
 177   {
 178     /* A chain of _DECL nodes for all variables, constants, functions,
 179        and typedef types.  These are in the reverse of the order
 180        supplied.  There may be OVERLOADs on this list, too, but they
 181        are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 182     tree names;
 183
 184     /* Count of elements in names chain.  */
 185     size_t names_size;
 186
 187     /* A chain of NAMESPACE_DECL nodes.  */
 188     tree namespaces;
 189
 190     /* An array of static functions and variables (for namespaces only) */
 191     VEC(tree,gc) *static_decls;
 192
 193     /* A list of USING_DECL nodes.  */
 194     tree usings;
 195
 196     /* A list of used namespaces. PURPOSE is the namespace,
 197        VALUE the common ancestor with this binding_level's namespace.  */
 198     tree using_directives;
 199
 200     /* For the binding level corresponding to a class, the entities
 201        declared in the class or its base classes.  */
 202     VEC(cp_class_binding,gc) *class_shadowed;
 203
 204     /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 205        is used for all binding levels. The TREE_PURPOSE is the name of
 206        the entity, the TREE_TYPE is the associated type.  In addition
 207        the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
 208        the class.  */
 209     tree type_shadowed;
 210
 211     /* A TREE_LIST.  Each TREE_VALUE is the LABEL_DECL for a local
 212        label in this scope.  The TREE_PURPOSE is the previous value of
 213        the IDENTIFIER_LABEL VALUE.  */
 214     tree shadowed_labels;
 215
 216     /* For each level (except not the global one),
 217        a chain of BLOCK nodes for all the levels
 218        that were entered and exited one level down.  */
 219     tree blocks;
 220
 221     /* The entity (namespace, class, function) the scope of which this
 222        binding contour corresponds to.  Otherwise NULL.  */
 223     tree this_entity;
 224
 225     /* The binding level which this one is contained in (inherits from).  */
 226     struct cp_binding_level *level_chain;
 227
 228     /* List of VAR_DECLS saved from a previous for statement.
 229        These would be dead in ISO-conforming code, but might
 230        be referenced in ARM-era code.  These are stored in a
 231        TREE_LIST; the TREE_VALUE is the actual declaration.  */
 232     tree dead_vars_from_for;
 233
 234     /* STATEMENT_LIST for statements in this binding contour.
 235        Only used at present for SK_CLEANUP temporary bindings.  */
 236     tree statement_list;
 237
 238     /* Binding depth at which this level began.  */
 239     int binding_depth;
 240
 241     /* The kind of scope that this object represents.  However, a
 242        SK_TEMPLATE_SPEC scope is represented with KIND set to
 243        SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true.  */
 244     ENUM_BITFIELD (scope_kind) kind : 4;
 245
 246     /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 247        only valid if KIND == SK_TEMPLATE_PARMS.  */
 248     BOOL_BITFIELD explicit_spec_p : 1;
 249
 250     /* true means make a BLOCK for this level regardless of all else.  */
 251     unsigned keep : 1;
 252
 253     /* Nonzero if this level can safely have additional
 254        cleanup-needing variables added to it.  */
 255     unsigned more_cleanups_ok : 1;
 256     unsigned have_cleanups : 1;
 257
 258     /* Nonzero if this level has associated visibility which we should pop
 259        when leaving the scope. */
 260     unsigned has_visibility : 1;
 261
 262     /* 23 bits left to fill a 32-bit word.  */
 263   };
 264
 265 /* The binding level currently in effect.  */
 266
 267 #define current_binding_level                   \
 268   (*(cfun && cp_function_chain->bindings        \
 269    ? &cp_function_chain->bindings               \
 270    : &scope_chain->bindings))
 271
 272 /* The binding level of the current class, if any.  */
 273
 274 #define class_binding_level scope_chain->class_bindings
 275
 276 /* The tree node representing the global scope.  */
 277 extern GTY(()) tree global_namespace;
 278 extern GTY(()) tree global_scope_name;
 279
 280 /* Indicates that there is a type value in some namespace, although
 281    that is not necessarily in scope at the moment.  */
 282
 283 extern GTY(()) tree global_type_node;
 284
 285 /* True if SCOPE designates the global scope binding contour.  */
 286 #define global_scope_p(SCOPE) \
 287   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 288
 289 extern cxx_scope *leave_scope (void);
 290 extern bool kept_level_p (void);
 291 extern int global_bindings_p (void);
 292 extern bool toplevel_bindings_p (void);
 293 extern bool namespace_bindings_p (void);
 294 extern bool template_parm_scope_p (void);
 295 extern scope_kind innermost_scope_kind (void);
 296 extern cxx_scope *begin_scope (scope_kind, tree);
 297 extern void print_binding_stack (void);
 298 extern void push_to_top_level (void);
 299 extern void pop_from_top_level (void);
 300 extern void pop_everything (void);
 301 extern void keep_next_level (bool);
 302 extern bool is_ancestor (tree, tree);
 303 extern tree push_scope (tree);
 304 extern void pop_scope (tree);
 305 extern tree push_inner_scope (tree);
 306 extern void pop_inner_scope (tree, tree);
 307 extern void push_binding_level (struct cp_binding_level *);
 308 \f
 309 extern void push_namespace (tree);
 310 extern void push_namespace_with_attribs (tree, tree);
 311 extern void pop_namespace (void);
 312 extern void push_nested_namespace (tree);
 313 extern void pop_nested_namespace (tree);
 314 extern void pushlevel_class (void);
 315 extern void poplevel_class (void);
 316 extern tree pushdecl_with_scope (tree, cxx_scope *, bool);
 317 extern tree lookup_name_prefer_type (tree, int);
 318 extern tree lookup_name_real (tree, int, int, bool, int, int);
 319 extern tree lookup_type_scope (tree, tag_scope);
 320 extern tree namespace_binding (tree, tree);
 321 extern void set_namespace_binding (tree, tree, tree);
 322 extern bool hidden_name_p (tree);
 323 extern tree remove_hidden_names (tree);
 324 extern tree lookup_qualified_name (tree, tree, bool, bool);
 325 extern tree lookup_name_nonclass (tree);
 326 extern tree lookup_function_nonclass (tree, tree, bool);
 327 extern void push_local_binding (tree, tree, int);
 328 extern bool pushdecl_class_level (tree);
 329 extern tree pushdecl_namespace_level (tree, bool);
 330 extern bool push_class_level_binding (tree, tree);
 331 extern tree getdecls (void);
 332 extern tree cp_namespace_decls (tree);
 333 extern void set_decl_namespace (tree, tree, bool);
 334 extern void push_decl_namespace (tree);
 335 extern void pop_decl_namespace (void);
 336 extern void do_namespace_alias (tree, tree);
 337 extern void do_toplevel_using_decl (tree, tree, tree);
 338 extern void do_local_using_decl (tree, tree, tree);
 339 extern tree do_class_using_decl (tree, tree);
 340 extern void do_using_directive (tree);
 341 extern tree lookup_arg_dependent (tree, tree, tree);
 342 extern bool is_associated_namespace (tree, tree);
 343 extern void parse_using_directive (tree, tree);
 344 extern tree innermost_non_namespace_value (tree);
 345 extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
 346 extern void cp_emit_debug_info_for_using (tree, tree);
 347
 348 /* Set *DECL to the (non-hidden) declaration for ID at global scope,
 349    if present and return true; otherwise return false.  */
 350
 351 static inline bool
 352 get_global_value_if_present (tree id, tree *decl)
 353 {
 354   tree global_value = namespace_binding (id, global_namespace);
 355   if (global_value)
 356     *decl = global_value;
 357   return global_value != NULL;
 358 }
 359
 360 /* True is the binding of IDENTIFIER at global scope names a type.  */
 361
 362 static inline bool
 363 is_typename_at_global_scope (tree id)
 364 {
 365   tree global_value = namespace_binding (id, global_namespace);
 366
 367   return global_value && TREE_CODE (global_value) == TYPE_DECL;
 368 }
 369
 370 #endif /* GCC_CP_NAME_LOOKUP_H */