gcc/cp/name-lookup.h

   1 /* Declarations for C++ name lookup routines.
   2    Copyright (C) 2003-2013 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-family/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 GTY(()) binding_entry_s {
  35   binding_entry chain;
  36   tree name;
  37   tree type;
  38 };
  39
  40 /* These macros indicate the initial chains count for binding_table.  */
  41 #define SCOPE_DEFAULT_HT_SIZE           (1 << 3)
  42 #define CLASS_SCOPE_HT_SIZE             (1 << 3)
  43 #define NAMESPACE_ORDINARY_HT_SIZE      (1 << 5)
  44 #define NAMESPACE_STD_HT_SIZE           (1 << 8)
  45 #define GLOBAL_SCOPE_HT_SIZE            (1 << 8)
  46
  47 extern void binding_table_foreach (binding_table, bt_foreach_proc, void *);
  48 extern binding_entry binding_table_find (binding_table, tree);
  49 \f
  50 /* Datatype that represents binding established by a declaration between
  51    a name and a C++ entity.  */
  52 typedef struct cxx_binding cxx_binding;
  53
  54 /* The datatype used to implement C++ scope.  */
  55 typedef struct cp_binding_level cp_binding_level;
  56
  57 /* Nonzero if this binding is for a local scope, as opposed to a class
  58    or namespace scope.  */
  59 #define LOCAL_BINDING_P(NODE) ((NODE)->is_local)
  60
  61 /* True if NODE->value is from a base class of the class which is
  62    currently being defined.  */
  63 #define INHERITED_VALUE_BINDING_P(NODE) ((NODE)->value_is_inherited)
  64
  65 struct GTY(()) cxx_binding {
  66   /* Link to chain together various bindings for this name.  */
  67   cxx_binding *previous;
  68   /* The non-type entity this name is bound to.  */
  69   tree value;
  70   /* The type entity this name is bound to.  */
  71   tree type;
  72   /* The scope at which this binding was made.  */
  73   cp_binding_level *scope;
  74   unsigned value_is_inherited : 1;
  75   unsigned is_local : 1;
  76 };
  77
  78 /* Datatype used to temporarily save C++ bindings (for implicit
  79    instantiations purposes and like).  Implemented in decl.c.  */
  80 typedef struct GTY(()) cxx_saved_binding {
  81   /* The name of the current binding.  */
  82   tree identifier;
  83   /* The binding we're saving.  */
  84   cxx_binding *binding;
  85   tree real_type_value;
  86 } cxx_saved_binding;
  87
  88
  89 extern tree identifier_type_value (tree);
  90 extern void set_identifier_type_value (tree, tree);
  91 extern void pop_binding (tree, tree);
  92 extern tree constructor_name (tree);
  93 extern bool constructor_name_p (tree, tree);
  94 \f
  95 /* The kinds of scopes we recognize.  */
  96 typedef enum scope_kind {
  97   sk_block = 0,      /* An ordinary block scope.  This enumerator must
  98                         have the value zero because "cp_binding_level"
  99                         is initialized by using "memset" to set the
 100                         contents to zero, and the default scope kind
 101                         is "sk_block".  */
 102   sk_cleanup,        /* A scope for (pseudo-)scope for cleanup.  It is
 103                         pseudo in that it is transparent to name lookup
 104                         activities.  */
 105   sk_try,            /* A try-block.  */
 106   sk_catch,          /* A catch-block.  */
 107   sk_for,            /* The scope of the variable declared in a
 108                         for-init-statement.  */
 109   sk_cond,           /* The scope of the variable declared in the condition
 110                         of an if or switch statement.  */
 111   sk_function_parms, /* The scope containing function parameters.  */
 112   sk_class,          /* The scope containing the members of a class.  */
 113   sk_scoped_enum,    /* The scope containing the enumertors of a C++0x
 114                         scoped enumeration.  */
 115   sk_namespace,      /* The scope containing the members of a
 116                         namespace, including the global scope.  */
 117   sk_template_parms, /* A scope for template parameters.  */
 118   sk_template_spec,  /* Like sk_template_parms, but for an explicit
 119                         specialization.  Since, by definition, an
 120                         explicit specialization is introduced by
 121                         "template <>", this scope is always empty.  */
 122   sk_omp             /* An OpenMP structured block.  */
 123 } scope_kind;
 124
 125 /* The scope where the class/struct/union/enum tag applies.  */
 126 typedef enum tag_scope {
 127   ts_current = 0,       /* Current scope only.  This is for the
 128                              class-key identifier;
 129                            case mentioned in [basic.lookup.elab]/2,
 130                            or the class/enum definition
 131                              class-key identifier { ... };  */
 132   ts_global = 1,        /* All scopes.  This is the 3.4.1
 133                            [basic.lookup.unqual] lookup mentioned
 134                            in [basic.lookup.elab]/2.  */
 135   ts_within_enclosing_non_class = 2     /* Search within enclosing non-class
 136                                            only, for friend class lookup
 137                                            according to [namespace.memdef]/3
 138                                            and [class.friend]/9.  */
 139 } tag_scope;
 140
 141 typedef struct GTY(()) cp_class_binding {
 142   cxx_binding *base;
 143   /* The bound name.  */
 144   tree identifier;
 145 } cp_class_binding;
 146
 147
 148 typedef struct GTY(()) cp_label_binding {
 149   /* The bound LABEL_DECL.  */
 150   tree label;
 151   /* The previous IDENTIFIER_LABEL_VALUE.  */
 152   tree prev_value;
 153 } cp_label_binding;
 154
 155
 156 /* For each binding contour we allocate a binding_level structure
 157    which records the names defined in that contour.
 158    Contours include:
 159     0) the global one
 160     1) one for each function definition,
 161        where internal declarations of the parameters appear.
 162     2) one for each compound statement,
 163        to record its declarations.
 164
 165    The current meaning of a name can be found by searching the levels
 166    from the current one out to the global one.
 167
 168    Off to the side, may be the class_binding_level.  This exists only
 169    to catch class-local declarations.  It is otherwise nonexistent.
 170
 171    Also there may be binding levels that catch cleanups that must be
 172    run when exceptions occur.  Thus, to see whether a name is bound in
 173    the current scope, it is not enough to look in the
 174    CURRENT_BINDING_LEVEL.  You should use lookup_name_current_level
 175    instead.  */
 176
 177 /* Note that the information in the `names' component of the global contour
 178    is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers.  */
 179
 180 struct GTY(()) cp_binding_level {
 181   /* A chain of _DECL nodes for all variables, constants, functions,
 182       and typedef types.  These are in the reverse of the order
 183       supplied.  There may be OVERLOADs on this list, too, but they
 184       are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 185   tree names;
 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, va_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, va_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   /* Similar to class_shadowed, but for IDENTIFIER_LABEL_VALUE, and
 212       used for all binding levels.  */
 213   vec<cp_label_binding, va_gc> *shadowed_labels;
 214
 215   /* For each level (except not the global one),
 216       a chain of BLOCK nodes for all the levels
 217       that were entered and exited one level down.  */
 218   tree blocks;
 219
 220   /* The entity (namespace, class, function) the scope of which this
 221       binding contour corresponds to.  Otherwise NULL.  */
 222   tree this_entity;
 223
 224   /* The binding level which this one is contained in (inherits from).  */
 225   cp_binding_level *level_chain;
 226
 227   /* List of VAR_DECLS saved from a previous for statement.
 228       These would be dead in ISO-conforming code, but might
 229       be referenced in ARM-era code.  */
 230   vec<tree, va_gc> *dead_vars_from_for;
 231
 232   /* STATEMENT_LIST for statements in this binding contour.
 233       Only used at present for SK_CLEANUP temporary bindings.  */
 234   tree statement_list;
 235
 236   /* Binding depth at which this level began.  */
 237   int binding_depth;
 238
 239   /* The kind of scope that this object represents.  However, a
 240       SK_TEMPLATE_SPEC scope is represented with KIND set to
 241       SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true.  */
 242   ENUM_BITFIELD (scope_kind) kind : 4;
 243
 244   /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 245       only valid if KIND == SK_TEMPLATE_PARMS.  */
 246   BOOL_BITFIELD explicit_spec_p : 1;
 247
 248   /* true means make a BLOCK for this level regardless of all else.  */
 249   unsigned keep : 1;
 250
 251   /* Nonzero if this level can safely have additional
 252       cleanup-needing variables added to it.  */
 253   unsigned more_cleanups_ok : 1;
 254   unsigned have_cleanups : 1;
 255
 256   /* 24 bits left to fill a 32-bit word.  */
 257 };
 258
 259 /* The binding level currently in effect.  */
 260
 261 #define current_binding_level                   \
 262   (*(cfun && cp_function_chain && cp_function_chain->bindings \
 263    ? &cp_function_chain->bindings               \
 264    : &scope_chain->bindings))
 265
 266 /* The binding level of the current class, if any.  */
 267
 268 #define class_binding_level scope_chain->class_bindings
 269
 270 /* The tree node representing the global scope.  */
 271 extern GTY(()) tree global_namespace;
 272 extern GTY(()) tree global_scope_name;
 273
 274 /* Indicates that there is a type value in some namespace, although
 275    that is not necessarily in scope at the moment.  */
 276
 277 extern GTY(()) tree global_type_node;
 278
 279 /* True if SCOPE designates the global scope binding contour.  */
 280 #define global_scope_p(SCOPE) \
 281   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 282
 283 extern cp_binding_level *leave_scope (void);
 284 extern bool kept_level_p (void);
 285 extern bool global_bindings_p (void);
 286 extern bool toplevel_bindings_p (void);
 287 extern bool namespace_bindings_p (void);
 288 extern bool local_bindings_p (void);
 289 extern bool template_parm_scope_p (void);
 290 extern scope_kind innermost_scope_kind (void);
 291 extern cp_binding_level *begin_scope (scope_kind, tree);
 292 extern void print_binding_stack (void);
 293 extern void push_to_top_level (void);
 294 extern void pop_from_top_level (void);
 295 extern void pop_everything (void);
 296 extern void keep_next_level (bool);
 297 extern bool is_ancestor (tree, tree);
 298 extern tree push_scope (tree);
 299 extern void pop_scope (tree);
 300 extern tree push_inner_scope (tree);
 301 extern void pop_inner_scope (tree, tree);
 302 extern void push_binding_level (cp_binding_level *);
 303 \f
 304 extern void push_namespace (tree);
 305 extern void pop_namespace (void);
 306 extern void push_nested_namespace (tree);
 307 extern void pop_nested_namespace (tree);
 308 extern bool handle_namespace_attrs (tree, tree);
 309 extern void pushlevel_class (void);
 310 extern void poplevel_class (void);
 311 extern tree pushdecl_with_scope (tree, cp_binding_level *, bool);
 312 extern tree lookup_name_prefer_type (tree, int);
 313 extern tree lookup_name_real (tree, int, int, bool, int, int);
 314 extern tree lookup_type_scope (tree, tag_scope);
 315 extern tree namespace_binding (tree, tree);
 316 extern void set_namespace_binding (tree, tree, tree);
 317 extern bool hidden_name_p (tree);
 318 extern tree remove_hidden_names (tree);
 319 extern tree lookup_qualified_name (tree, tree, bool, bool);
 320 extern tree lookup_name_nonclass (tree);
 321 extern tree lookup_name_innermost_nonclass_level (tree);
 322 extern bool is_local_extern (tree);
 323 extern tree lookup_function_nonclass (tree, vec<tree, va_gc> *, bool);
 324 extern void push_local_binding (tree, tree, int);
 325 extern bool pushdecl_class_level (tree);
 326 extern tree pushdecl_namespace_level (tree, bool);
 327 extern bool push_class_level_binding (tree, tree);
 328 extern tree getdecls (void);
 329 extern int function_parm_depth (void);
 330 extern tree cp_namespace_decls (tree);
 331 extern void set_decl_namespace (tree, tree, bool);
 332 extern void push_decl_namespace (tree);
 333 extern void pop_decl_namespace (void);
 334 extern void do_namespace_alias (tree, tree);
 335 extern void do_toplevel_using_decl (tree, tree, tree);
 336 extern void do_local_using_decl (tree, tree, tree);
 337 extern tree do_class_using_decl (tree, tree);
 338 extern void do_using_directive (tree);
 339 extern tree lookup_arg_dependent (tree, tree, vec<tree, va_gc> *, bool);
 340 extern bool is_associated_namespace (tree, tree);
 341 extern void parse_using_directive (tree, tree);
 342 extern tree innermost_non_namespace_value (tree);
 343 extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
 344 extern void cp_emit_debug_info_for_using (tree, tree);
 345
 346 /* Set *DECL to the (non-hidden) declaration for ID at global scope,
 347    if present and return true; otherwise return false.  */
 348
 349 static inline bool
 350 get_global_value_if_present (tree id, tree *decl)
 351 {
 352   tree global_value = namespace_binding (id, global_namespace);
 353   if (global_value)
 354     *decl = global_value;
 355   return global_value != NULL;
 356 }
 357
 358 /* True is the binding of IDENTIFIER at global scope names a type.  */
 359
 360 static inline bool
 361 is_typename_at_global_scope (tree id)
 362 {
 363   tree global_value = namespace_binding (id, global_namespace);
 364
 365   return global_value && TREE_CODE (global_value) == TYPE_DECL;
 366 }
 367
 368 #endif /* GCC_CP_NAME_LOOKUP_H */