gcc/cp/name-lookup.h

   1 /* Declarations for -*- C++ -*- name lookup routines.
   2    Copyright (C) 2003-2020 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_local_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                         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 enumerators of a C++11
 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 /* For each binding contour we allocate a binding_level structure
 152    which records the names defined in that contour.
 153    Contours include:
 154     0) the global one
 155     1) one for each function definition,
 156        where internal declarations of the parameters appear.
 157     2) one for each compound statement,
 158        to record its declarations.
 159
 160    The current meaning of a name can be found by searching the levels
 161    from the current one out to the global one.
 162
 163    Off to the side, may be the class_binding_level.  This exists only
 164    to catch class-local declarations.  It is otherwise nonexistent.
 165
 166    Also there may be binding levels that catch cleanups that must be
 167    run when exceptions occur.  Thus, to see whether a name is bound in
 168    the current scope, it is not enough to look in the
 169    CURRENT_BINDING_LEVEL.  You should use lookup_name_current_level
 170    instead.  */
 171
 172 struct GTY(()) cp_binding_level {
 173   /* A chain of _DECL nodes for all variables, constants, functions,
 174       and typedef types.  These are in the reverse of the order
 175       supplied.  There may be OVERLOADs on this list, too, but they
 176       are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 177   tree names;
 178
 179   /* Using directives.  */
 180   vec<tree, va_gc> *using_directives;
 181
 182   /* For the binding level corresponding to a class, the entities
 183       declared in the class or its base classes.  */
 184   vec<cp_class_binding, va_gc> *class_shadowed;
 185
 186   /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 187       is used for all binding levels. The TREE_PURPOSE is the name of
 188       the entity, the TREE_TYPE is the associated type.  In addition
 189       the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
 190       the class.  */
 191   tree type_shadowed;
 192
 193   /* For each level (except not the global one),
 194       a chain of BLOCK nodes for all the levels
 195       that were entered and exited one level down.  */
 196   tree blocks;
 197
 198   /* The entity (namespace, class, function) the scope of which this
 199       binding contour corresponds to.  Otherwise NULL.  */
 200   tree this_entity;
 201
 202   /* The binding level which this one is contained in (inherits from).  */
 203   cp_binding_level *level_chain;
 204
 205   /* STATEMENT_LIST for statements in this binding contour.
 206       Only used at present for SK_CLEANUP temporary bindings.  */
 207   tree statement_list;
 208
 209   /* Binding depth at which this level began.  */
 210   int binding_depth;
 211
 212   /* The kind of scope that this object represents.  However, a
 213       SK_TEMPLATE_SPEC scope is represented with KIND set to
 214       SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true.  */
 215   ENUM_BITFIELD (scope_kind) kind : 4;
 216
 217   /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 218       only valid if KIND == SK_TEMPLATE_PARMS.  */
 219   BOOL_BITFIELD explicit_spec_p : 1;
 220
 221   /* true means make a BLOCK for this level regardless of all else.  */
 222   unsigned keep : 1;
 223
 224   /* Nonzero if this level can safely have additional
 225       cleanup-needing variables added to it.  */
 226   unsigned more_cleanups_ok : 1;
 227   unsigned have_cleanups : 1;
 228
 229   /* Transient state set if this scope is of sk_class kind
 230      and is in the process of defining 'this_entity'.  Reset
 231      on leaving the class definition to allow for the scope
 232      to be subsequently re-used as a non-defining scope for
 233      'this_entity'.  */
 234   unsigned defining_class_p : 1;
 235
 236   /* true for SK_FUNCTION_PARMS of immediate functions.  */
 237   unsigned immediate_fn_ctx_p : 1;
 238
 239   /* 22 bits left to fill a 32-bit word.  */
 240 };
 241
 242 /* The binding level currently in effect.  */
 243
 244 #define current_binding_level                   \
 245   (*(cfun && cp_function_chain && cp_function_chain->bindings \
 246    ? &cp_function_chain->bindings               \
 247    : &scope_chain->bindings))
 248
 249 /* The binding level of the current class, if any.  */
 250
 251 #define class_binding_level scope_chain->class_bindings
 252
 253 /* True if SCOPE designates the global scope binding contour.  */
 254 #define global_scope_p(SCOPE) \
 255   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 256
 257 extern cp_binding_level *leave_scope (void);
 258 extern bool kept_level_p (void);
 259 extern bool global_bindings_p (void);
 260 extern bool toplevel_bindings_p (void);
 261 extern bool namespace_bindings_p (void);
 262 extern bool local_bindings_p (void);
 263 extern bool template_parm_scope_p (void);
 264 extern scope_kind innermost_scope_kind (void);
 265 extern cp_binding_level *begin_scope (scope_kind, tree);
 266 extern void print_binding_stack (void);
 267 extern void pop_everything (void);
 268 extern void keep_next_level (bool);
 269 extern bool is_ancestor (tree ancestor, tree descendant);
 270 extern bool is_nested_namespace (tree parent, tree descendant,
 271                                  bool inline_only = false);
 272 extern tree push_scope (tree);
 273 extern void pop_scope (tree);
 274 extern tree push_inner_scope (tree);
 275 extern void pop_inner_scope (tree, tree);
 276 extern void push_binding_level (cp_binding_level *);
 277 \f
 278 extern bool handle_namespace_attrs (tree, tree);
 279 extern void pushlevel_class (void);
 280 extern void poplevel_class (void);
 281
 282 /* What kind of scopes name lookup looks in.  An enum class so we
 283    don't accidentally mix integers.  */
 284 enum class LOOK_where
 285 {
 286   BLOCK = 1 << 0,  /* Consider block scopes.  */
 287   CLASS = 1 << 1,  /* Consider class scopes.  */
 288   NAMESPACE = 1 << 2,  /* Consider namespace scopes.  */
 289
 290   ALL = BLOCK | CLASS | NAMESPACE,
 291   BLOCK_NAMESPACE = BLOCK | NAMESPACE,
 292   CLASS_NAMESPACE = CLASS | NAMESPACE,
 293 };
 294 constexpr LOOK_where operator| (LOOK_where a, LOOK_where b)
 295 {
 296   return LOOK_where (unsigned (a) | unsigned (b));
 297 }
 298 constexpr LOOK_where operator& (LOOK_where a, LOOK_where b)
 299 {
 300   return LOOK_where (unsigned (a) & unsigned (b));
 301 }
 302
 303 enum class LOOK_want
 304 {
 305   NORMAL = 0,  /* Normal lookup -- non-types can hide implicit types.  */
 306   TYPE = 1 << 1,  /* We only want TYPE_DECLS.  */
 307   NAMESPACE = 1 << 2,  /* We only want NAMESPACE_DECLS.  */
 308
 309   HIDDEN_FRIEND = 1 << 3, /* See hidden friends.  */
 310   HIDDEN_LAMBDA = 1 << 4,  /* See lambda-ignored entities.  */
 311
 312   TYPE_NAMESPACE = TYPE | NAMESPACE,  /* Either NAMESPACE or TYPE.  */
 313 };
 314 constexpr LOOK_want operator| (LOOK_want a, LOOK_want b)
 315 {
 316   return LOOK_want (unsigned (a) | unsigned (b));
 317 }
 318 constexpr LOOK_want operator& (LOOK_want a, LOOK_want b)
 319 {
 320   return LOOK_want (unsigned (a) & unsigned (b));
 321 }
 322
 323 extern tree lookup_name (tree, LOOK_where, LOOK_want = LOOK_want::NORMAL);
 324 /* Also declared in c-family/c-common.h.  */
 325 extern tree lookup_name (tree name);
 326 inline tree lookup_name (tree name, LOOK_want want)
 327 {
 328   return lookup_name (name, LOOK_where::ALL, want);
 329 }
 330
 331 extern tree lookup_type_scope (tree, tag_scope);
 332 extern tree get_namespace_binding (tree ns, tree id);
 333 extern void set_global_binding (tree decl);
 334 inline tree get_global_binding (tree id)
 335 {
 336   return get_namespace_binding (NULL_TREE, id);
 337 }
 338 extern tree lookup_qualified_name (tree scope, tree name,
 339                                    LOOK_want = LOOK_want::NORMAL,
 340                                    bool = true);
 341 extern tree lookup_qualified_name (tree scope, const char *name,
 342                                    LOOK_want = LOOK_want::NORMAL,
 343                                    bool = true);
 344 extern bool is_local_extern (tree);
 345 extern bool pushdecl_class_level (tree);
 346 extern tree pushdecl_namespace_level (tree, bool);
 347 extern bool push_class_level_binding (tree, tree);
 348 extern tree get_local_decls ();
 349 extern int function_parm_depth (void);
 350 extern tree cp_namespace_decls (tree);
 351 extern void set_decl_namespace (tree, tree, bool);
 352 extern void push_decl_namespace (tree);
 353 extern void pop_decl_namespace (void);
 354 extern void do_namespace_alias (tree, tree);
 355 extern tree do_class_using_decl (tree, tree);
 356 extern tree lookup_arg_dependent (tree, tree, vec<tree, va_gc> *);
 357 extern tree search_anon_aggr (tree, tree, bool = false);
 358 extern tree get_class_binding_direct (tree, tree, bool want_type = false);
 359 extern tree get_class_binding (tree, tree, bool want_type = false);
 360 extern tree *find_member_slot (tree klass, tree name);
 361 extern tree *add_member_slot (tree klass, tree name);
 362 extern void resort_type_member_vec (void *, void *,
 363                                     gt_pointer_operator, void *);
 364 extern void set_class_bindings (tree, unsigned extra = 0);
 365 extern void insert_late_enum_def_bindings (tree, tree);
 366 extern tree innermost_non_namespace_value (tree);
 367 extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
 368 extern void cp_emit_debug_info_for_using (tree, tree);
 369
 370 extern void finish_nonmember_using_decl (tree scope, tree name);
 371 extern void finish_using_directive (tree target, tree attribs);
 372 extern tree pushdecl (tree, bool is_friend = false);
 373 extern tree pushdecl_outermost_localscope (tree);
 374 extern tree pushdecl_top_level (tree, bool is_friend = false);
 375 extern tree pushdecl_top_level_and_finish (tree, tree);
 376 extern tree pushtag (tree, tree, tag_scope);
 377 extern int push_namespace (tree, bool make_inline = false);
 378 extern void pop_namespace (void);
 379 extern void push_nested_namespace (tree);
 380 extern void pop_nested_namespace (tree);
 381 extern void push_to_top_level (void);
 382 extern void pop_from_top_level (void);
 383 extern void maybe_save_operator_binding (tree);
 384 extern void push_operator_bindings (void);
 385 extern void discard_operator_bindings (tree);
 386
 387 #endif /* GCC_CP_NAME_LOOKUP_H */