gcc/cp/name-lookup.h

   1 /* Declarations for C++ name lookup routines.
   2    Copyright (C) 2003-2016 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 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 };
  87
  88
  89 extern tree identifier_type_value (tree);
  90 extern void set_identifier_type_value (tree, tree);
  91 extern void push_binding (tree, tree, cp_binding_level*);
  92 extern void pop_binding (tree, tree);
  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 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_transaction,    /* A synchronized or atomic statement.  */
 125   sk_omp             /* An OpenMP structured block.  */
 126 };
 127
 128 /* The scope where the class/struct/union/enum tag applies.  */
 129 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   ts_lambda = 3                 /* Declaring a lambda closure.  */
 143 };
 144
 145 struct GTY(()) cp_class_binding {
 146   cxx_binding *base;
 147   /* The bound name.  */
 148   tree identifier;
 149 };
 150
 151
 152 struct GTY(()) cp_label_binding {
 153   /* The bound LABEL_DECL.  */
 154   tree label;
 155   /* The previous IDENTIFIER_LABEL_VALUE.  */
 156   tree prev_value;
 157 };
 158
 159
 160 /* For each binding contour we allocate a binding_level structure
 161    which records the names defined in that contour.
 162    Contours include:
 163     0) the global one
 164     1) one for each function definition,
 165        where internal declarations of the parameters appear.
 166     2) one for each compound statement,
 167        to record its declarations.
 168
 169    The current meaning of a name can be found by searching the levels
 170    from the current one out to the global one.
 171
 172    Off to the side, may be the class_binding_level.  This exists only
 173    to catch class-local declarations.  It is otherwise nonexistent.
 174
 175    Also there may be binding levels that catch cleanups that must be
 176    run when exceptions occur.  Thus, to see whether a name is bound in
 177    the current scope, it is not enough to look in the
 178    CURRENT_BINDING_LEVEL.  You should use lookup_name_current_level
 179    instead.  */
 180
 181 /* Note that the information in the `names' component of the global contour
 182    is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers.  */
 183
 184 struct GTY(()) cp_binding_level {
 185   /* A chain of _DECL nodes for all variables, constants, functions,
 186       and typedef types.  These are in the reverse of the order
 187       supplied.  There may be OVERLOADs on this list, too, but they
 188       are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 189   tree names;
 190
 191   /* A chain of NAMESPACE_DECL nodes.  */
 192   tree namespaces;
 193
 194   /* An array of static functions and variables (for namespaces only) */
 195   vec<tree, va_gc> *static_decls;
 196
 197   /* A list of USING_DECL nodes.  */
 198   tree usings;
 199
 200   /* A list of used namespaces. PURPOSE is the namespace,
 201       VALUE the common ancestor with this binding_level's namespace.  */
 202   tree using_directives;
 203
 204   /* For the binding level corresponding to a class, the entities
 205       declared in the class or its base classes.  */
 206   vec<cp_class_binding, va_gc> *class_shadowed;
 207
 208   /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 209       is used for all binding levels. The TREE_PURPOSE is the name of
 210       the entity, the TREE_TYPE is the associated type.  In addition
 211       the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
 212       the class.  */
 213   tree type_shadowed;
 214
 215   /* Similar to class_shadowed, but for IDENTIFIER_LABEL_VALUE, and
 216       used for all binding levels.  */
 217   vec<cp_label_binding, va_gc> *shadowed_labels;
 218
 219   /* For each level (except not the global one),
 220       a chain of BLOCK nodes for all the levels
 221       that were entered and exited one level down.  */
 222   tree blocks;
 223
 224   /* The entity (namespace, class, function) the scope of which this
 225       binding contour corresponds to.  Otherwise NULL.  */
 226   tree this_entity;
 227
 228   /* The binding level which this one is contained in (inherits from).  */
 229   cp_binding_level *level_chain;
 230
 231   /* List of VAR_DECLS saved from a previous for statement.
 232       These would be dead in ISO-conforming code, but might
 233       be referenced in ARM-era code.  */
 234   vec<tree, va_gc> *dead_vars_from_for;
 235
 236   /* STATEMENT_LIST for statements in this binding contour.
 237       Only used at present for SK_CLEANUP temporary bindings.  */
 238   tree statement_list;
 239
 240   /* Binding depth at which this level began.  */
 241   int binding_depth;
 242
 243   /* The kind of scope that this object represents.  However, a
 244       SK_TEMPLATE_SPEC scope is represented with KIND set to
 245       SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true.  */
 246   ENUM_BITFIELD (scope_kind) kind : 4;
 247
 248   /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 249       only valid if KIND == SK_TEMPLATE_PARMS.  */
 250   BOOL_BITFIELD explicit_spec_p : 1;
 251
 252   /* true means make a BLOCK for this level regardless of all else.  */
 253   unsigned keep : 1;
 254
 255   /* Nonzero if this level can safely have additional
 256       cleanup-needing variables added to it.  */
 257   unsigned more_cleanups_ok : 1;
 258   unsigned have_cleanups : 1;
 259
 260   /* Transient state set if this scope is of sk_class kind
 261      and is in the process of defining 'this_entity'.  Reset
 262      on leaving the class definition to allow for the scope
 263      to be subsequently re-used as a non-defining scope for
 264      'this_entity'.  */
 265   unsigned defining_class_p : 1;
 266
 267   /* 23 bits left to fill a 32-bit word.  */
 268 };
 269
 270 /* The binding level currently in effect.  */
 271
 272 #define current_binding_level                   \
 273   (*(cfun && cp_function_chain && cp_function_chain->bindings \
 274    ? &cp_function_chain->bindings               \
 275    : &scope_chain->bindings))
 276
 277 /* The binding level of the current class, if any.  */
 278
 279 #define class_binding_level scope_chain->class_bindings
 280
 281 /* The tree node representing the global scope.  */
 282 extern GTY(()) tree global_namespace;
 283 extern GTY(()) tree global_scope_name;
 284
 285 /* Indicates that there is a type value in some namespace, although
 286    that is not necessarily in scope at the moment.  */
 287
 288 extern GTY(()) tree global_type_node;
 289
 290 /* True if SCOPE designates the global scope binding contour.  */
 291 #define global_scope_p(SCOPE) \
 292   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 293
 294 extern cp_binding_level *leave_scope (void);
 295 extern bool kept_level_p (void);
 296 extern bool global_bindings_p (void);
 297 extern bool toplevel_bindings_p (void);
 298 extern bool namespace_bindings_p (void);
 299 extern bool local_bindings_p (void);
 300 extern bool template_parm_scope_p (void);
 301 extern scope_kind innermost_scope_kind (void);
 302 extern cp_binding_level *begin_scope (scope_kind, tree);
 303 extern void print_binding_stack (void);
 304 extern void push_to_top_level (void);
 305 extern void pop_from_top_level (void);
 306 extern void pop_everything (void);
 307 extern void keep_next_level (bool);
 308 extern bool is_ancestor (tree, tree);
 309 extern tree push_scope (tree);
 310 extern void pop_scope (tree);
 311 extern tree push_inner_scope (tree);
 312 extern void pop_inner_scope (tree, tree);
 313 extern void push_binding_level (cp_binding_level *);
 314 \f
 315 extern bool push_namespace (tree);
 316 extern void pop_namespace (void);
 317 extern void push_nested_namespace (tree);
 318 extern void pop_nested_namespace (tree);
 319 extern bool handle_namespace_attrs (tree, tree);
 320 extern void pushlevel_class (void);
 321 extern void poplevel_class (void);
 322 extern tree pushdecl_with_scope (tree, cp_binding_level *, bool);
 323 extern tree lookup_name_prefer_type (tree, int);
 324 extern tree lookup_name_real (tree, int, int, bool, int, int);
 325 extern tree lookup_type_scope (tree, tag_scope);
 326 extern tree namespace_binding (tree, tree);
 327 extern void set_namespace_binding (tree, tree, tree);
 328 extern bool hidden_name_p (tree);
 329 extern tree remove_hidden_names (tree);
 330 extern tree lookup_qualified_name (tree, tree, int, bool, /*hidden*/bool = false);
 331 extern tree lookup_name_nonclass (tree);
 332 extern tree lookup_name_innermost_nonclass_level (tree);
 333 extern bool is_local_extern (tree);
 334 extern tree lookup_function_nonclass (tree, vec<tree, va_gc> *, bool);
 335 extern void push_local_binding (tree, tree, int);
 336 extern bool pushdecl_class_level (tree);
 337 extern tree pushdecl_namespace_level (tree, bool);
 338 extern bool push_class_level_binding (tree, tree);
 339 extern tree getdecls (void);
 340 extern int function_parm_depth (void);
 341 extern tree cp_namespace_decls (tree);
 342 extern void set_decl_namespace (tree, tree, bool);
 343 extern void push_decl_namespace (tree);
 344 extern void pop_decl_namespace (void);
 345 extern void do_namespace_alias (tree, tree);
 346 extern void do_toplevel_using_decl (tree, tree, tree);
 347 extern void do_local_using_decl (tree, tree, tree);
 348 extern tree do_class_using_decl (tree, tree);
 349 extern void do_using_directive (tree);
 350 extern cp_expr lookup_arg_dependent (tree, tree, vec<tree, va_gc> *);
 351 extern bool is_associated_namespace (tree, tree);
 352 extern void parse_using_directive (tree, tree);
 353 extern tree innermost_non_namespace_value (tree);
 354 extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
 355 extern void cp_emit_debug_info_for_using (tree, tree);
 356
 357 /* Set *DECL to the (non-hidden) declaration for ID at global scope,
 358    if present and return true; otherwise return false.  */
 359
 360 inline bool
 361 get_global_value_if_present (tree id, tree *decl)
 362 {
 363   tree global_value = namespace_binding (id, global_namespace);
 364   if (global_value)
 365     *decl = global_value;
 366   return global_value != NULL;
 367 }
 368
 369 /* True is the binding of IDENTIFIER at global scope names a type.  */
 370
 371 inline bool
 372 is_typename_at_global_scope (tree id)
 373 {
 374   tree global_value = namespace_binding (id, global_namespace);
 375
 376   return global_value && TREE_CODE (global_value) == TYPE_DECL;
 377 }
 378
 379 #endif /* GCC_CP_NAME_LOOKUP_H */