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