gcc/cp/name-lookup.h

   1 /* Declarations for C++ name lookup routines.
   2    Copyright (C) 2003, 2004 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, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, 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_remove_anonymous_types (binding_table);
  50 extern void binding_table_foreach (binding_table, bt_foreach_proc, void *);
  51 extern binding_entry binding_table_find (binding_table, tree);
  52 extern void cxx_remember_type_decls (binding_table);
  53 \f
  54 /* Datatype that represents binding established by a declaration between
  55    a name and a C++ entity.  */
  56 typedef struct cxx_binding cxx_binding;
  57
  58 /* The datatype used to implement C++ scope.  */
  59 typedef struct cp_binding_level cxx_scope;
  60
  61 /* Nonzero if this binding is for a local scope, as opposed to a class
  62    or namespace scope.  */
  63 #define LOCAL_BINDING_P(NODE) ((NODE)->is_local)
  64
  65 /* True if NODE->value is from a base class of the class which is
  66    currently being defined.  */
  67 #define INHERITED_VALUE_BINDING_P(NODE) ((NODE)->value_is_inherited)
  68
  69 struct cxx_binding GTY(())
  70 {
  71   /* Link to chain together various bindings for this name.  */
  72   cxx_binding *previous;
  73   /* The non-type entity this name is bound to.  */
  74   tree value;
  75   /* The type entity this name is bound to.  */
  76   tree type;
  77   /* The scope at which this binding was made.  */
  78   cxx_scope *scope;
  79   unsigned value_is_inherited : 1;
  80   unsigned is_local : 1;
  81 };
  82
  83 /* Datatype used to temporarily save C++ bindings (for implicit
  84    instantiations purposes and like).  Implemented in decl.c.  */
  85 typedef struct cxx_saved_binding GTY(())
  86 {
  87   /* The name of the current binding.  */
  88   tree identifier;
  89   /* The binding we're saving.  */
  90   cxx_binding *binding;
  91   tree class_value;
  92   tree real_type_value;
  93 } cxx_saved_binding;
  94
  95 DEF_VEC_O(cxx_saved_binding);
  96
  97 extern tree identifier_type_value (tree);
  98 extern void set_identifier_type_value (tree, tree);
  99 extern void pop_binding (tree, tree);
 100 extern void clear_identifier_class_values (void);
 101 extern tree constructor_name_full (tree);
 102 extern tree constructor_name (tree);
 103 extern bool constructor_name_p (tree, tree);
 104 \f
 105 /* The kinds of scopes we recognize.  */
 106 typedef enum scope_kind {
 107   sk_block = 0,      /* An ordinary block scope.  This enumerator must
 108                         have the value zero because "cp_binding_level"
 109                         is initialized by using "memset" to set the
 110                         contents to zero, and the default scope kind
 111                         is "sk_block".  */
 112   sk_cleanup,        /* A scope for (pseudo-)scope for cleanup.  It is
 113                         peusdo in that it is transparent to name lookup
 114                         activities.  */
 115   sk_try,            /* A try-block.  */
 116   sk_catch,          /* A catch-block.  */
 117   sk_for,            /* The scope of the variable declared in a
 118                         for-init-statement.  */
 119   sk_function_parms, /* The scope containing function parameters.  */
 120   sk_class,          /* The scope containing the members of a class.  */
 121   sk_namespace,      /* The scope containing the members of a
 122                         namespace, including the global scope.  */
 123   sk_template_parms, /* A scope for template parameters.  */
 124   sk_template_spec   /* Like sk_template_parms, but for an explicit
 125                         specialization.  Since, by definition, an
 126                         explicit specialization is introduced by
 127                         "template <>", this scope is always empty.  */
 128 } scope_kind;
 129
 130 typedef struct cp_class_binding GTY(())
 131 {
 132   cxx_binding base;
 133   /* The bound name.  */
 134   tree identifier;
 135 } cp_class_binding;
 136
 137 DEF_VEC_O(cp_class_binding);
 138
 139 /* For each binding contour we allocate a binding_level structure
 140    which records the names defined in that contour.
 141    Contours include:
 142     0) the global one
 143     1) one for each function definition,
 144        where internal declarations of the parameters appear.
 145     2) one for each compound statement,
 146        to record its declarations.
 147
 148    The current meaning of a name can be found by searching the levels
 149    from the current one out to the global one.
 150
 151    Off to the side, may be the class_binding_level.  This exists only
 152    to catch class-local declarations.  It is otherwise nonexistent.
 153
 154    Also there may be binding levels that catch cleanups that must be
 155    run when exceptions occur.  Thus, to see whether a name is bound in
 156    the current scope, it is not enough to look in the
 157    CURRENT_BINDING_LEVEL.  You should use lookup_name_current_level
 158    instead.  */
 159
 160 /* Note that the information in the `names' component of the global contour
 161    is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers.  */
 162
 163 struct cp_binding_level GTY(())
 164   {
 165     /* A chain of _DECL nodes for all variables, constants, functions,
 166        and typedef types.  These are in the reverse of the order
 167        supplied.  There may be OVERLOADs on this list, too, but they
 168        are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 169     tree names;
 170
 171     /* Count of elements in names chain.  */
 172     size_t names_size;
 173
 174     /* A chain of NAMESPACE_DECL nodes.  */
 175     tree namespaces;
 176
 177     /* An array of static functions and variables (for namespaces only) */
 178     varray_type static_decls;
 179
 180     /* A chain of VTABLE_DECL nodes.  */
 181     tree vtables;
 182
 183     /* A dictionary for looking up user-defined-types.  */
 184     binding_table type_decls;
 185
 186     /* A list of USING_DECL nodes.  */
 187     tree usings;
 188
 189     /* A list of used namespaces. PURPOSE is the namespace,
 190        VALUE the common ancestor with this binding_level's namespace.  */
 191     tree using_directives;
 192
 193     /* For the binding level corresponding to a class, the entities
 194        declared in the class or its base classes.  */
 195     VEC(cp_class_binding) *class_shadowed;
 196
 197     /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 198        is used for all binding levels. The TREE_PURPOSE is the name of
 199        the entity, the TREE_TYPE is the associated type.  In addition
 200        the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
 201        the class.  */
 202     tree type_shadowed;
 203
 204     /* A TREE_LIST.  Each TREE_VALUE is the LABEL_DECL for a local
 205        label in this scope.  The TREE_PURPOSE is the previous value of
 206        the IDENTIFIER_LABEL VALUE.  */
 207     tree shadowed_labels;
 208
 209     /* For each level (except not the global one),
 210        a chain of BLOCK nodes for all the levels
 211        that were entered and exited one level down.  */
 212     tree blocks;
 213
 214     /* The entity (namespace, class, function) the scope of which this
 215        binding contour corresponds to.  Otherwise NULL.  */
 216     tree this_entity;
 217
 218     /* The binding level which this one is contained in (inherits from).  */
 219     struct cp_binding_level *level_chain;
 220
 221     /* List of VAR_DECLS saved from a previous for statement.
 222        These would be dead in ISO-conforming code, but might
 223        be referenced in ARM-era code.  These are stored in a
 224        TREE_LIST; the TREE_VALUE is the actual declaration.  */
 225     tree dead_vars_from_for;
 226
 227     /* STATEMENT_LIST for statements in this binding contour.
 228        Only used at present for SK_CLEANUP temporary bindings.  */
 229     tree statement_list;
 230
 231     /* Binding depth at which this level began.  */
 232     int binding_depth;
 233
 234     /* The kind of scope that this object represents.  However, a
 235        SK_TEMPLATE_SPEC scope is represented with KIND set to
 236        SK_TEMPALTE_PARMS and EXPLICIT_SPEC_P set to true.  */
 237     ENUM_BITFIELD (scope_kind) kind : 4;
 238
 239     /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 240        only valid if KIND == SK_TEMPLATE_PARMS.  */
 241     BOOL_BITFIELD explicit_spec_p : 1;
 242
 243     /* true means make a BLOCK for this level regardless of all else.  */
 244     unsigned keep : 1;
 245
 246     /* Nonzero if this level can safely have additional
 247        cleanup-needing variables added to it.  */
 248     unsigned more_cleanups_ok : 1;
 249     unsigned have_cleanups : 1;
 250
 251     /* 22 bits left to fill a 32-bit word.  */
 252   };
 253
 254 /* The binding level currently in effect.  */
 255
 256 #define current_binding_level                   \
 257   (*(cfun && cp_function_chain->bindings        \
 258    ? &cp_function_chain->bindings               \
 259    : &scope_chain->bindings))
 260
 261 /* The binding level of the current class, if any.  */
 262
 263 #define class_binding_level scope_chain->class_bindings
 264
 265 /* The tree node representing the global scope.  */
 266 extern GTY(()) tree global_namespace;
 267 extern GTY(()) tree global_scope_name;
 268
 269 /* Indicates that there is a type value in some namespace, although
 270    that is not necessarily in scope at the moment.  */
 271
 272 extern GTY(()) tree global_type_node;
 273
 274 /* True if SCOPE designates the global scope binding contour.  */
 275 #define global_scope_p(SCOPE) \
 276   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 277
 278 extern cxx_scope *leave_scope (void);
 279 extern bool kept_level_p (void);
 280 extern int global_bindings_p (void);
 281 extern bool toplevel_bindings_p (void);
 282 extern bool namespace_bindings_p (void);
 283 extern bool template_parm_scope_p (void);
 284 extern scope_kind innermost_scope_kind (void);
 285 extern cxx_scope *begin_scope (scope_kind, tree);
 286 extern void print_binding_stack (void);
 287 extern void print_binding_level (cxx_scope *);
 288 extern void push_to_top_level (void);
 289 extern void pop_from_top_level (void);
 290 extern void pop_everything (void);
 291 extern void keep_next_level (bool);
 292 extern bool is_ancestor (tree, tree);
 293 extern bool push_scope (tree);
 294 extern void pop_scope (tree);
 295 extern void push_binding_level (struct cp_binding_level *);
 296 \f
 297 extern void push_namespace (tree);
 298 extern void pop_namespace (void);
 299 extern void push_nested_namespace (tree);
 300 extern void pop_nested_namespace (tree);
 301 extern void pushlevel_class (void);
 302 extern void poplevel_class (void);
 303 extern tree pushdecl_with_scope (tree, cxx_scope *);
 304 extern tree lookup_tag (enum tree_code, tree, cxx_scope *, int);
 305 extern tree lookup_tag_reverse (tree, tree);
 306 extern tree lookup_name (tree, int);
 307 extern tree lookup_name_real (tree, int, int, bool, int, int);
 308 extern tree namespace_binding (tree, tree);
 309 extern void set_namespace_binding (tree, tree, tree);
 310 extern tree lookup_namespace_name (tree, tree);
 311 extern tree lookup_qualified_name (tree, tree, bool, bool);
 312 extern tree lookup_name_nonclass (tree);
 313 extern tree lookup_function_nonclass (tree, tree, bool);
 314 extern void push_local_binding (tree, tree, int);
 315 extern int push_class_binding (tree, tree);
 316 extern bool pushdecl_class_level (tree);
 317 extern tree pushdecl_namespace_level (tree);
 318 extern bool push_class_level_binding (tree, tree);
 319 extern void storetags (tree);
 320 extern tree getdecls (void);
 321 extern tree cp_namespace_decls (tree);
 322 extern void set_decl_namespace (tree, tree, bool);
 323 extern tree current_decl_namespace (void);
 324 extern void push_decl_namespace (tree);
 325 extern void pop_decl_namespace (void);
 326 extern void do_namespace_alias (tree, tree);
 327 extern void do_toplevel_using_decl (tree, tree, tree);
 328 extern void do_local_using_decl (tree, tree, tree);
 329 extern tree do_class_using_decl (tree);
 330 extern void do_using_directive (tree);
 331 extern tree lookup_arg_dependent (tree, tree, tree);
 332 extern bool is_associated_namespace (tree, tree);
 333 extern void parse_using_directive (tree, tree);
 334
 335
 336 /* Set *DECL to the (non-hidden) declaration for ID at global scope,
 337    if present and return true; otherwise return false.  */
 338
 339 static inline bool
 340 get_global_value_if_present (tree id, tree *decl)
 341 {
 342   tree global_value = namespace_binding (id, global_namespace);
 343   if (global_value)
 344     *decl = global_value;
 345   return global_value != NULL;
 346 }
 347
 348 /* True is the binding of IDENTIFIER at global scope names a type.  */
 349
 350 static inline bool
 351 is_typename_at_global_scope (tree id)
 352 {
 353   tree global_value = namespace_binding (id, global_namespace);
 354
 355   return global_value && TREE_CODE (global_value) == TYPE_DECL;
 356 }
 357
 358 #endif /* GCC_CP_NAME_LOOKUP_H */