gcc/cp/name-lookup.h

   1 /* Declarations for C++ name lookup routines.
   2    Copyright (C) 2003-2015 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_bindings_and_leave_scope (void);
  93 extern tree constructor_name (tree);
  94 extern bool constructor_name_p (tree, tree);
  95 \f
  96 /* The kinds of scopes we recognize.  */
  97 typedef enum scope_kind {
  98   sk_block = 0,      /* An ordinary block scope.  This enumerator must
  99                         have the value zero because "cp_binding_level"
 100                         is initialized by using "memset" to set the
 101                         contents to zero, and the default scope kind
 102                         is "sk_block".  */
 103   sk_cleanup,        /* A scope for (pseudo-)scope for cleanup.  It is
 104                         pseudo in that it is transparent to name lookup
 105                         activities.  */
 106   sk_try,            /* A try-block.  */
 107   sk_catch,          /* A catch-block.  */
 108   sk_for,            /* The scope of the variable declared in a
 109                         for-init-statement.  */
 110   sk_cond,           /* The scope of the variable declared in the condition
 111                         of an if or switch statement.  */
 112   sk_function_parms, /* The scope containing function parameters.  */
 113   sk_class,          /* The scope containing the members of a class.  */
 114   sk_scoped_enum,    /* The scope containing the enumertors of a C++0x
 115                         scoped enumeration.  */
 116   sk_namespace,      /* The scope containing the members of a
 117                         namespace, including the global scope.  */
 118   sk_template_parms, /* A scope for template parameters.  */
 119   sk_template_spec,  /* Like sk_template_parms, but for an explicit
 120                         specialization.  Since, by definition, an
 121                         explicit specialization is introduced by
 122                         "template <>", this scope is always empty.  */
 123   sk_omp             /* An OpenMP structured block.  */
 124 } scope_kind;
 125
 126 /* The scope where the class/struct/union/enum tag applies.  */
 127 typedef enum tag_scope {
 128   ts_current = 0,       /* Current scope only.  This is for the
 129                              class-key identifier;
 130                            case mentioned in [basic.lookup.elab]/2,
 131                            or the class/enum definition
 132                              class-key identifier { ... };  */
 133   ts_global = 1,        /* All scopes.  This is the 3.4.1
 134                            [basic.lookup.unqual] lookup mentioned
 135                            in [basic.lookup.elab]/2.  */
 136   ts_within_enclosing_non_class = 2,    /* Search within enclosing non-class
 137                                            only, for friend class lookup
 138                                            according to [namespace.memdef]/3
 139                                            and [class.friend]/9.  */
 140   ts_lambda = 3                 /* Declaring a lambda closure.  */
 141 } tag_scope;
 142
 143 typedef struct GTY(()) cp_class_binding {
 144   cxx_binding *base;
 145   /* The bound name.  */
 146   tree identifier;
 147 } cp_class_binding;
 148
 149
 150 typedef struct GTY(()) cp_label_binding {
 151   /* The bound LABEL_DECL.  */
 152   tree label;
 153   /* The previous IDENTIFIER_LABEL_VALUE.  */
 154   tree prev_value;
 155 } cp_label_binding;
 156
 157
 158 /* For each binding contour we allocate a binding_level structure
 159    which records the names defined in that contour.
 160    Contours include:
 161     0) the global one
 162     1) one for each function definition,
 163        where internal declarations of the parameters appear.
 164     2) one for each compound statement,
 165        to record its declarations.
 166
 167    The current meaning of a name can be found by searching the levels
 168    from the current one out to the global one.
 169
 170    Off to the side, may be the class_binding_level.  This exists only
 171    to catch class-local declarations.  It is otherwise nonexistent.
 172
 173    Also there may be binding levels that catch cleanups that must be
 174    run when exceptions occur.  Thus, to see whether a name is bound in
 175    the current scope, it is not enough to look in the
 176    CURRENT_BINDING_LEVEL.  You should use lookup_name_current_level
 177    instead.  */
 178
 179 /* Note that the information in the `names' component of the global contour
 180    is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers.  */
 181
 182 struct GTY(()) cp_binding_level {
 183   /* A chain of _DECL nodes for all variables, constants, functions,
 184       and typedef types.  These are in the reverse of the order
 185       supplied.  There may be OVERLOADs on this list, too, but they
 186       are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 187   tree names;
 188
 189   /* A chain of NAMESPACE_DECL nodes.  */
 190   tree namespaces;
 191
 192   /* An array of static functions and variables (for namespaces only) */
 193   vec<tree, va_gc> *static_decls;
 194
 195   /* A list of USING_DECL nodes.  */
 196   tree usings;
 197
 198   /* A list of used namespaces. PURPOSE is the namespace,
 199       VALUE the common ancestor with this binding_level's namespace.  */
 200   tree using_directives;
 201
 202   /* For the binding level corresponding to a class, the entities
 203       declared in the class or its base classes.  */
 204   vec<cp_class_binding, va_gc> *class_shadowed;
 205
 206   /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 207       is used for all binding levels. The TREE_PURPOSE is the name of
 208       the entity, the TREE_TYPE is the associated type.  In addition
 209       the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
 210       the class.  */
 211   tree type_shadowed;
 212
 213   /* Similar to class_shadowed, but for IDENTIFIER_LABEL_VALUE, and
 214       used for all binding levels.  */
 215   vec<cp_label_binding, va_gc> *shadowed_labels;
 216
 217   /* For each level (except not the global one),
 218       a chain of BLOCK nodes for all the levels
 219       that were entered and exited one level down.  */
 220   tree blocks;
 221
 222   /* The entity (namespace, class, function) the scope of which this
 223       binding contour corresponds to.  Otherwise NULL.  */
 224   tree this_entity;
 225
 226   /* The binding level which this one is contained in (inherits from).  */
 227   cp_binding_level *level_chain;
 228
 229   /* List of VAR_DECLS saved from a previous for statement.
 230       These would be dead in ISO-conforming code, but might
 231       be referenced in ARM-era code.  */
 232   vec<tree, va_gc> *dead_vars_from_for;
 233
 234   /* STATEMENT_LIST for statements in this binding contour.
 235       Only used at present for SK_CLEANUP temporary bindings.  */
 236   tree statement_list;
 237
 238   /* Binding depth at which this level began.  */
 239   int binding_depth;
 240
 241   /* The kind of scope that this object represents.  However, a
 242       SK_TEMPLATE_SPEC scope is represented with KIND set to
 243       SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true.  */
 244   ENUM_BITFIELD (scope_kind) kind : 4;
 245
 246   /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 247       only valid if KIND == SK_TEMPLATE_PARMS.  */
 248   BOOL_BITFIELD explicit_spec_p : 1;
 249
 250   /* true means make a BLOCK for this level regardless of all else.  */
 251   unsigned keep : 1;
 252
 253   /* Nonzero if this level can safely have additional
 254       cleanup-needing variables added to it.  */
 255   unsigned more_cleanups_ok : 1;
 256   unsigned have_cleanups : 1;
 257
 258   /* Transient state set if this scope is of sk_class kind
 259      and is in the process of defining 'this_entity'.  Reset
 260      on leaving the class definition to allow for the scope
 261      to be subsequently re-used as a non-defining scope for
 262      'this_entity'.  */
 263   unsigned defining_class_p : 1;
 264
 265   /* 23 bits left to fill a 32-bit word.  */
 266 };
 267
 268 /* The binding level currently in effect.  */
 269
 270 #define current_binding_level                   \
 271   (*(cfun && cp_function_chain && cp_function_chain->bindings \
 272    ? &cp_function_chain->bindings               \
 273    : &scope_chain->bindings))
 274
 275 /* The binding level of the current class, if any.  */
 276
 277 #define class_binding_level scope_chain->class_bindings
 278
 279 /* The tree node representing the global scope.  */
 280 extern GTY(()) tree global_namespace;
 281 extern GTY(()) tree global_scope_name;
 282
 283 /* Indicates that there is a type value in some namespace, although
 284    that is not necessarily in scope at the moment.  */
 285
 286 extern GTY(()) tree global_type_node;
 287
 288 /* True if SCOPE designates the global scope binding contour.  */
 289 #define global_scope_p(SCOPE) \
 290   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 291
 292 extern cp_binding_level *leave_scope (void);
 293 extern bool kept_level_p (void);
 294 extern bool global_bindings_p (void);
 295 extern bool toplevel_bindings_p (void);
 296 extern bool namespace_bindings_p (void);
 297 extern bool local_bindings_p (void);
 298 extern bool template_parm_scope_p (void);
 299 extern scope_kind innermost_scope_kind (void);
 300 extern cp_binding_level *begin_scope (scope_kind, tree);
 301 extern void print_binding_stack (void);
 302 extern void push_to_top_level (void);
 303 extern void pop_from_top_level (void);
 304 extern void pop_everything (void);
 305 extern void keep_next_level (bool);
 306 extern bool is_ancestor (tree, tree);
 307 extern tree push_scope (tree);
 308 extern void pop_scope (tree);
 309 extern tree push_inner_scope (tree);
 310 extern void pop_inner_scope (tree, tree);
 311 extern void push_binding_level (cp_binding_level *);
 312 \f
 313 extern void push_namespace (tree);
 314 extern void pop_namespace (void);
 315 extern void push_nested_namespace (tree);
 316 extern void pop_nested_namespace (tree);
 317 extern bool handle_namespace_attrs (tree, tree);
 318 extern void pushlevel_class (void);
 319 extern void poplevel_class (void);
 320 extern tree pushdecl_with_scope (tree, cp_binding_level *, bool);
 321 extern tree lookup_name_prefer_type (tree, int);
 322 extern tree lookup_name_real (tree, int, int, bool, int, int);
 323 extern tree lookup_type_scope (tree, tag_scope);
 324 extern tree namespace_binding (tree, tree);
 325 extern void set_namespace_binding (tree, tree, tree);
 326 extern bool hidden_name_p (tree);
 327 extern tree remove_hidden_names (tree);
 328 extern tree lookup_qualified_name (tree, tree, bool, bool);
 329 extern tree lookup_name_nonclass (tree);
 330 extern tree lookup_name_innermost_nonclass_level (tree);
 331 extern bool is_local_extern (tree);
 332 extern tree lookup_function_nonclass (tree, vec<tree, va_gc> *, bool);
 333 extern void push_local_binding (tree, tree, int);
 334 extern bool pushdecl_class_level (tree);
 335 extern tree pushdecl_namespace_level (tree, bool);
 336 extern bool push_class_level_binding (tree, tree);
 337 extern tree getdecls (void);
 338 extern int function_parm_depth (void);
 339 extern tree cp_namespace_decls (tree);
 340 extern void set_decl_namespace (tree, tree, bool);
 341 extern void push_decl_namespace (tree);
 342 extern void pop_decl_namespace (void);
 343 extern void do_namespace_alias (tree, tree);
 344 extern void do_toplevel_using_decl (tree, tree, tree);
 345 extern void do_local_using_decl (tree, tree, tree);
 346 extern tree do_class_using_decl (tree, tree);
 347 extern void do_using_directive (tree);
 348 extern tree lookup_arg_dependent (tree, tree, vec<tree, va_gc> *);
 349 extern bool is_associated_namespace (tree, tree);
 350 extern void parse_using_directive (tree, tree);
 351 extern tree innermost_non_namespace_value (tree);
 352 extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
 353 extern void cp_emit_debug_info_for_using (tree, tree);
 354
 355 /* Set *DECL to the (non-hidden) declaration for ID at global scope,
 356    if present and return true; otherwise return false.  */
 357
 358 inline bool
 359 get_global_value_if_present (tree id, tree *decl)
 360 {
 361   tree global_value = namespace_binding (id, global_namespace);
 362   if (global_value)
 363     *decl = global_value;
 364   return global_value != NULL;
 365 }
 366
 367 /* True is the binding of IDENTIFIER at global scope names a type.  */
 368
 369 inline bool
 370 is_typename_at_global_scope (tree id)
 371 {
 372   tree global_value = namespace_binding (id, global_namespace);
 373
 374   return global_value && TREE_CODE (global_value) == TYPE_DECL;
 375 }
 376
 377 #endif /* GCC_CP_NAME_LOOKUP_H */