gcc/cp/name-lookup.h

   1 /* Declarations for C++ name lookup routines.
   2    Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010
   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 cp_binding_level;
  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   cp_binding_level *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_cond,           /* The scope of the variable declared in the condition
 113                         of an if or switch statement.  */
 114   sk_function_parms, /* The scope containing function parameters.  */
 115   sk_class,          /* The scope containing the members of a class.  */
 116   sk_scoped_enum,    /* The scope containing the enumertors of a C++0x
 117                         scoped enumeration.  */
 118   sk_namespace,      /* The scope containing the members of a
 119                         namespace, including the global scope.  */
 120   sk_template_parms, /* A scope for template parameters.  */
 121   sk_template_spec,  /* Like sk_template_parms, but for an explicit
 122                         specialization.  Since, by definition, an
 123                         explicit specialization is introduced by
 124                         "template <>", this scope is always empty.  */
 125   sk_omp             /* An OpenMP structured block.  */
 126 } scope_kind;
 127
 128 /* The scope where the class/struct/union/enum tag applies.  */
 129 typedef enum tag_scope {
 130   ts_current = 0,       /* Current scope only.  This is for the
 131                              class-key identifier;
 132                            case mentioned in [basic.lookup.elab]/2,
 133                            or the class/enum definition
 134                              class-key identifier { ... };  */
 135   ts_global = 1,        /* All scopes.  This is the 3.4.1
 136                            [basic.lookup.unqual] lookup mentioned
 137                            in [basic.lookup.elab]/2.  */
 138   ts_within_enclosing_non_class = 2     /* Search within enclosing non-class
 139                                            only, for friend class lookup
 140                                            according to [namespace.memdef]/3
 141                                            and [class.friend]/9.  */
 142 } tag_scope;
 143
 144 typedef struct GTY(()) cp_class_binding {
 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 typedef struct GTY(()) cp_label_binding {
 154   /* The bound LABEL_DECL.  */
 155   tree label;
 156   /* The previous IDENTIFIER_LABEL_VALUE.  */
 157   tree prev_value;
 158 } cp_label_binding;
 159
 160 DEF_VEC_O(cp_label_binding);
 161 DEF_VEC_ALLOC_O(cp_label_binding,gc);
 162
 163 /* For each binding contour we allocate a binding_level structure
 164    which records the names defined in that contour.
 165    Contours include:
 166     0) the global one
 167     1) one for each function definition,
 168        where internal declarations of the parameters appear.
 169     2) one for each compound statement,
 170        to record its declarations.
 171
 172    The current meaning of a name can be found by searching the levels
 173    from the current one out to the global one.
 174
 175    Off to the side, may be the class_binding_level.  This exists only
 176    to catch class-local declarations.  It is otherwise nonexistent.
 177
 178    Also there may be binding levels that catch cleanups that must be
 179    run when exceptions occur.  Thus, to see whether a name is bound in
 180    the current scope, it is not enough to look in the
 181    CURRENT_BINDING_LEVEL.  You should use lookup_name_current_level
 182    instead.  */
 183
 184 /* Note that the information in the `names' component of the global contour
 185    is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers.  */
 186
 187 struct GTY(()) cp_binding_level {
 188   /* A chain of _DECL nodes for all variables, constants, functions,
 189       and typedef types.  These are in the reverse of the order
 190       supplied.  There may be OVERLOADs on this list, too, but they
 191       are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 192   tree names;
 193
 194   /* A chain of NAMESPACE_DECL nodes.  */
 195   tree namespaces;
 196
 197   /* An array of static functions and variables (for namespaces only) */
 198   VEC(tree,gc) *static_decls;
 199
 200   /* A list of USING_DECL nodes.  */
 201   tree usings;
 202
 203   /* A list of used namespaces. PURPOSE is the namespace,
 204       VALUE the common ancestor with this binding_level's namespace.  */
 205   tree using_directives;
 206
 207   /* For the binding level corresponding to a class, the entities
 208       declared in the class or its base classes.  */
 209   VEC(cp_class_binding,gc) *class_shadowed;
 210
 211   /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 212       is used for all binding levels. The TREE_PURPOSE is the name of
 213       the entity, the TREE_TYPE is the associated type.  In addition
 214       the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
 215       the class.  */
 216   tree type_shadowed;
 217
 218   /* Similar to class_shadowed, but for IDENTIFIER_LABEL_VALUE, and
 219       used for all binding levels.  */
 220   VEC(cp_label_binding,gc) *shadowed_labels;
 221
 222   /* For each level (except not the global one),
 223       a chain of BLOCK nodes for all the levels
 224       that were entered and exited one level down.  */
 225   tree blocks;
 226
 227   /* The entity (namespace, class, function) the scope of which this
 228       binding contour corresponds to.  Otherwise NULL.  */
 229   tree this_entity;
 230
 231   /* The binding level which this one is contained in (inherits from).  */
 232   cp_binding_level *level_chain;
 233
 234   /* List of VAR_DECLS saved from a previous for statement.
 235       These would be dead in ISO-conforming code, but might
 236       be referenced in ARM-era code.  */
 237   VEC(tree,gc) *dead_vars_from_for;
 238
 239   /* STATEMENT_LIST for statements in this binding contour.
 240       Only used at present for SK_CLEANUP temporary bindings.  */
 241   tree statement_list;
 242
 243   /* Binding depth at which this level began.  */
 244   int binding_depth;
 245
 246   /* The kind of scope that this object represents.  However, a
 247       SK_TEMPLATE_SPEC scope is represented with KIND set to
 248       SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true.  */
 249   ENUM_BITFIELD (scope_kind) kind : 4;
 250
 251   /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 252       only valid if KIND == SK_TEMPLATE_PARMS.  */
 253   BOOL_BITFIELD explicit_spec_p : 1;
 254
 255   /* true means make a BLOCK for this level regardless of all else.  */
 256   unsigned keep : 1;
 257
 258   /* Nonzero if this level can safely have additional
 259       cleanup-needing variables added to it.  */
 260   unsigned more_cleanups_ok : 1;
 261   unsigned have_cleanups : 1;
 262
 263   /* 24 bits left to fill a 32-bit word.  */
 264 };
 265
 266 /* The binding level currently in effect.  */
 267
 268 #define current_binding_level                   \
 269   (*(cfun && cp_function_chain && cp_function_chain->bindings \
 270    ? &cp_function_chain->bindings               \
 271    : &scope_chain->bindings))
 272
 273 /* The binding level of the current class, if any.  */
 274
 275 #define class_binding_level scope_chain->class_bindings
 276
 277 /* The tree node representing the global scope.  */
 278 extern GTY(()) tree global_namespace;
 279 extern GTY(()) tree global_scope_name;
 280
 281 /* Indicates that there is a type value in some namespace, although
 282    that is not necessarily in scope at the moment.  */
 283
 284 extern GTY(()) tree global_type_node;
 285
 286 /* True if SCOPE designates the global scope binding contour.  */
 287 #define global_scope_p(SCOPE) \
 288   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 289
 290 extern cp_binding_level *leave_scope (void);
 291 extern bool kept_level_p (void);
 292 extern bool global_bindings_p (void);
 293 extern bool toplevel_bindings_p (void);
 294 extern bool namespace_bindings_p (void);
 295 extern bool local_bindings_p (void);
 296 extern bool template_parm_scope_p (void);
 297 extern scope_kind innermost_scope_kind (void);
 298 extern cp_binding_level *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 (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, cp_binding_level *, 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 int function_parm_depth (void);
 337 extern tree cp_namespace_decls (tree);
 338 extern void set_decl_namespace (tree, tree, bool);
 339 extern void push_decl_namespace (tree);
 340 extern void pop_decl_namespace (void);
 341 extern void do_namespace_alias (tree, tree);
 342 extern void do_toplevel_using_decl (tree, tree, tree);
 343 extern void do_local_using_decl (tree, tree, tree);
 344 extern tree do_class_using_decl (tree, tree);
 345 extern void do_using_directive (tree);
 346 extern tree lookup_arg_dependent (tree, tree, VEC(tree,gc) *, bool);
 347 extern bool is_associated_namespace (tree, tree);
 348 extern void parse_using_directive (tree, tree);
 349 extern tree innermost_non_namespace_value (tree);
 350 extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
 351 extern void cp_emit_debug_info_for_using (tree, tree);
 352
 353 /* Set *DECL to the (non-hidden) declaration for ID at global scope,
 354    if present and return true; otherwise return false.  */
 355
 356 static inline bool
 357 get_global_value_if_present (tree id, tree *decl)
 358 {
 359   tree global_value = namespace_binding (id, global_namespace);
 360   if (global_value)
 361     *decl = global_value;
 362   return global_value != NULL;
 363 }
 364
 365 /* True is the binding of IDENTIFIER at global scope names a type.  */
 366
 367 static inline bool
 368 is_typename_at_global_scope (tree id)
 369 {
 370   tree global_value = namespace_binding (id, global_namespace);
 371
 372   return global_value && TREE_CODE (global_value) == TYPE_DECL;
 373 }
 374
 375 #endif /* GCC_CP_NAME_LOOKUP_H */