main/gcc/cp/name-lookup.h

   1 /* Declarations for C++ name lookup routines.
   2    Copyright (C) 2003-2014 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 void pop_global_binding (tree, cxx_binding*);
  93 extern void pop_bindings_and_leave_scope (void);
  94 extern tree constructor_name (tree);
  95 extern bool constructor_name_p (tree, tree);
  96 \f
  97 /* The kinds of scopes we recognize.  */
  98 typedef enum scope_kind {
  99   sk_block = 0,      /* An ordinary block scope.  This enumerator must
 100                         have the value zero because "cp_binding_level"
 101                         is initialized by using "memset" to set the
 102                         contents to zero, and the default scope kind
 103                         is "sk_block".  */
 104   sk_cleanup,        /* A scope for (pseudo-)scope for cleanup.  It is
 105                         pseudo in that it is transparent to name lookup
 106                         activities.  */
 107   sk_try,            /* A try-block.  */
 108   sk_catch,          /* A catch-block.  */
 109   sk_for,            /* The scope of the variable declared in a
 110                         for-init-statement.  */
 111   sk_cond,           /* The scope of the variable declared in the condition
 112                         of an if or switch statement.  */
 113   sk_function_parms, /* The scope containing function parameters.  */
 114   sk_class,          /* The scope containing the members of a class.  */
 115   sk_scoped_enum,    /* The scope containing the enumertors of a C++0x
 116                         scoped enumeration.  */
 117   sk_namespace,      /* The scope containing the members of a
 118                         namespace, including the global scope.  */
 119   sk_template_parms, /* A scope for template parameters.  */
 120   sk_template_spec,  /* Like sk_template_parms, but for an explicit
 121                         specialization.  Since, by definition, an
 122                         explicit specialization is introduced by
 123                         "template <>", this scope is always empty.  */
 124   sk_omp             /* An OpenMP structured block.  */
 125 } scope_kind;
 126
 127 /* The scope where the class/struct/union/enum tag applies.  */
 128 typedef enum tag_scope {
 129   ts_current = 0,       /* Current scope only.  This is for the
 130                              class-key identifier;
 131                            case mentioned in [basic.lookup.elab]/2,
 132                            or the class/enum definition
 133                              class-key identifier { ... };  */
 134   ts_global = 1,        /* All scopes.  This is the 3.4.1
 135                            [basic.lookup.unqual] lookup mentioned
 136                            in [basic.lookup.elab]/2.  */
 137   ts_within_enclosing_non_class = 2,    /* Search within enclosing non-class
 138                                            only, for friend class lookup
 139                                            according to [namespace.memdef]/3
 140                                            and [class.friend]/9.  */
 141   ts_lambda = 3                 /* Declaring a lambda closure.  */
 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
 151 typedef struct GTY(()) cp_label_binding {
 152   /* The bound LABEL_DECL.  */
 153   tree label;
 154   /* The previous IDENTIFIER_LABEL_VALUE.  */
 155   tree prev_value;
 156 } cp_label_binding;
 157
 158
 159 /* For each binding contour we allocate a binding_level structure
 160    which records the names defined in that contour.
 161    Contours include:
 162     0) the global one
 163     1) one for each function definition,
 164        where internal declarations of the parameters appear.
 165     2) one for each compound statement,
 166        to record its declarations.
 167
 168    The current meaning of a name can be found by searching the levels
 169    from the current one out to the global one.
 170
 171    Off to the side, may be the class_binding_level.  This exists only
 172    to catch class-local declarations.  It is otherwise nonexistent.
 173
 174    Also there may be binding levels that catch cleanups that must be
 175    run when exceptions occur.  Thus, to see whether a name is bound in
 176    the current scope, it is not enough to look in the
 177    CURRENT_BINDING_LEVEL.  You should use lookup_name_current_level
 178    instead.  */
 179
 180 /* Note that the information in the `names' component of the global contour
 181    is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers.  */
 182
 183 struct GTY(()) cp_binding_level {
 184   /* A chain of _DECL nodes for all variables, constants, functions,
 185       and typedef types.  These are in the reverse of the order
 186       supplied.  There may be OVERLOADs on this list, too, but they
 187       are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 188   tree names;
 189
 190   /* A chain of NAMESPACE_DECL nodes.  */
 191   tree namespaces;
 192
 193   /* An array of static functions and variables (for namespaces only) */
 194   vec<tree, va_gc> *static_decls;
 195
 196   /* A list of USING_DECL nodes.  */
 197   tree usings;
 198
 199   /* A list of used namespaces. PURPOSE is the namespace,
 200       VALUE the common ancestor with this binding_level's namespace.  */
 201   tree using_directives;
 202
 203   /* For the binding level corresponding to a class, the entities
 204       declared in the class or its base classes.  */
 205   vec<cp_class_binding, va_gc> *class_shadowed;
 206
 207   /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 208       is used for all binding levels. The TREE_PURPOSE is the name of
 209       the entity, the TREE_TYPE is the associated type.  In addition
 210       the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
 211       the class.  */
 212   tree type_shadowed;
 213
 214   /* Similar to class_shadowed, but for IDENTIFIER_LABEL_VALUE, and
 215       used for all binding levels.  */
 216   vec<cp_label_binding, va_gc> *shadowed_labels;
 217
 218   /* For each level (except not the global one),
 219       a chain of BLOCK nodes for all the levels
 220       that were entered and exited one level down.  */
 221   tree blocks;
 222
 223   /* The entity (namespace, class, function) the scope of which this
 224       binding contour corresponds to.  Otherwise NULL.  */
 225   tree this_entity;
 226
 227   /* The binding level which this one is contained in (inherits from).  */
 228   cp_binding_level *level_chain;
 229
 230   /* List of VAR_DECLS saved from a previous for statement.
 231       These would be dead in ISO-conforming code, but might
 232       be referenced in ARM-era code.  */
 233   vec<tree, va_gc> *dead_vars_from_for;
 234
 235   /* STATEMENT_LIST for statements in this binding contour.
 236       Only used at present for SK_CLEANUP temporary bindings.  */
 237   tree statement_list;
 238
 239   /* Binding depth at which this level began.  */
 240   int binding_depth;
 241
 242   /* The kind of scope that this object represents.  However, a
 243       SK_TEMPLATE_SPEC scope is represented with KIND set to
 244       SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true.  */
 245   ENUM_BITFIELD (scope_kind) kind : 4;
 246
 247   /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 248       only valid if KIND == SK_TEMPLATE_PARMS.  */
 249   BOOL_BITFIELD explicit_spec_p : 1;
 250
 251   /* true means make a BLOCK for this level regardless of all else.  */
 252   unsigned keep : 1;
 253
 254   /* Nonzero if this level can safely have additional
 255       cleanup-needing variables added to it.  */
 256   unsigned more_cleanups_ok : 1;
 257   unsigned have_cleanups : 1;
 258
 259   /* Transient state set if this scope is of sk_class kind
 260      and is in the process of defining 'this_entity'.  Reset
 261      on leaving the class definition to allow for the scope
 262      to be subsequently re-used as a non-defining scope for
 263      'this_entity'.  */
 264   unsigned defining_class_p : 1;
 265
 266   /* 23 bits left to fill a 32-bit word.  */
 267 };
 268
 269 /* The binding level currently in effect.  */
 270
 271 #define current_binding_level                   \
 272   (*(cfun && cp_function_chain && cp_function_chain->bindings \
 273    ? &cp_function_chain->bindings               \
 274    : &scope_chain->bindings))
 275
 276 /* The binding level of the current class, if any.  */
 277
 278 #define class_binding_level scope_chain->class_bindings
 279
 280 /* The tree node representing the global scope.  */
 281 extern GTY(()) tree global_namespace;
 282 extern GTY(()) tree global_scope_name;
 283
 284 /* Indicates that there is a type value in some namespace, although
 285    that is not necessarily in scope at the moment.  */
 286
 287 extern GTY(()) tree global_type_node;
 288
 289 /* True if SCOPE designates the global scope binding contour.  */
 290 #define global_scope_p(SCOPE) \
 291   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 292
 293 extern cp_binding_level *leave_scope (void);
 294 extern bool kept_level_p (void);
 295 extern bool global_bindings_p (void);
 296 extern bool toplevel_bindings_p (void);
 297 extern bool namespace_bindings_p (void);
 298 extern bool local_bindings_p (void);
 299 extern bool template_parm_scope_p (void);
 300 extern scope_kind innermost_scope_kind (void);
 301 extern cp_binding_level *begin_scope (scope_kind, tree);
 302 extern void print_binding_stack (void);
 303 extern void push_to_top_level (void);
 304 extern void pop_from_top_level (void);
 305 extern void pop_everything (void);
 306 extern void keep_next_level (bool);
 307 extern bool is_ancestor (tree, tree);
 308 extern tree push_scope (tree);
 309 extern void pop_scope (tree);
 310 extern tree push_inner_scope (tree);
 311 extern void pop_inner_scope (tree, tree);
 312 extern void push_binding_level (cp_binding_level *);
 313 \f
 314 extern void push_namespace (tree);
 315 extern void pop_namespace (void);
 316 extern void push_nested_namespace (tree);
 317 extern void pop_nested_namespace (tree);
 318 extern bool handle_namespace_attrs (tree, tree);
 319 extern void pushlevel_class (void);
 320 extern void poplevel_class (void);
 321 extern tree pushdecl_with_scope (tree, cp_binding_level *, bool);
 322 extern tree lookup_name_prefer_type (tree, int);
 323 extern tree lookup_name_real (tree, int, int, bool, int, int);
 324 extern tree lookup_type_scope (tree, tag_scope);
 325 extern tree namespace_binding (tree, tree);
 326 extern void set_namespace_binding (tree, tree, tree);
 327 extern bool hidden_name_p (tree);
 328 extern tree remove_hidden_names (tree);
 329 extern tree lookup_qualified_name (tree, tree, bool, bool);
 330 extern tree lookup_name_nonclass (tree);
 331 extern tree lookup_name_innermost_nonclass_level (tree);
 332 extern bool is_local_extern (tree);
 333 extern tree lookup_function_nonclass (tree, vec<tree, va_gc> *, bool);
 334 extern void push_local_binding (tree, tree, int);
 335 extern bool pushdecl_class_level (tree);
 336 extern tree pushdecl_namespace_level (tree, bool);
 337 extern bool push_class_level_binding (tree, tree);
 338 extern tree getdecls (void);
 339 extern int function_parm_depth (void);
 340 extern tree cp_namespace_decls (tree);
 341 extern void set_decl_namespace (tree, tree, bool);
 342 extern void push_decl_namespace (tree);
 343 extern void pop_decl_namespace (void);
 344 extern void do_namespace_alias (tree, tree);
 345 extern void do_toplevel_using_decl (tree, tree, tree);
 346 extern void do_local_using_decl (tree, tree, tree);
 347 extern tree do_class_using_decl (tree, tree);
 348 extern void do_using_directive (tree);
 349 extern tree lookup_arg_dependent (tree, tree, vec<tree, va_gc> *);
 350 extern bool is_associated_namespace (tree, tree);
 351 extern void parse_using_directive (tree, tree);
 352 extern tree innermost_non_namespace_value (tree);
 353 extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
 354 extern void cp_emit_debug_info_for_using (tree, tree);
 355
 356 /* Set *DECL to the (non-hidden) declaration for ID at global scope,
 357    if present and return true; otherwise return false.  */
 358
 359 inline bool
 360 get_global_value_if_present (tree id, tree *decl)
 361 {
 362   tree global_value = namespace_binding (id, global_namespace);
 363   if (global_value)
 364     *decl = global_value;
 365   return global_value != NULL;
 366 }
 367
 368 /* True is the binding of IDENTIFIER at global scope names a type.  */
 369
 370 inline bool
 371 is_typename_at_global_scope (tree id)
 372 {
 373   tree global_value = namespace_binding (id, global_namespace);
 374
 375   return global_value && TREE_CODE (global_value) == TYPE_DECL;
 376 }
 377
 378 #endif /* GCC_CP_NAME_LOOKUP_H */