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 };
 143
 144 struct GTY(()) cp_class_binding {
 145   cxx_binding *base;
 146   /* The bound name.  */
 147   tree identifier;
 148 };
 149
 150 /* For each binding contour we allocate a binding_level structure
 151    which records the names defined in that contour.
 152    Contours include:
 153     0) the global one
 154     1) one for each function definition,
 155        where internal declarations of the parameters appear.
 156     2) one for each compound statement,
 157        to record its declarations.
 158
 159    The current meaning of a name can be found by searching the levels
 160    from the current one out to the global one.
 161
 162    Off to the side, may be the class_binding_level.  This exists only
 163    to catch class-local declarations.  It is otherwise nonexistent.
 164
 165    Also there may be binding levels that catch cleanups that must be
 166    run when exceptions occur.  Thus, to see whether a name is bound in
 167    the current scope, it is not enough to look in the
 168    CURRENT_BINDING_LEVEL.  You should use lookup_name_current_level
 169    instead.  */
 170
 171 struct GTY(()) cp_binding_level {
 172   /* A chain of _DECL nodes for all variables, constants, functions,
 173       and typedef types.  These are in the reverse of the order
 174       supplied.  There may be OVERLOADs on this list, too, but they
 175       are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD.  */
 176   tree names;
 177
 178   /* Using directives.  */
 179   vec<tree, va_gc> *using_directives;
 180
 181   /* For the binding level corresponding to a class, the entities
 182       declared in the class or its base classes.  */
 183   vec<cp_class_binding, va_gc> *class_shadowed;
 184
 185   /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
 186       is used for all binding levels. The TREE_PURPOSE is the name of
 187       the entity, the TREE_TYPE is the associated type.  In addition
 188       the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
 189       the class.  */
 190   tree type_shadowed;
 191
 192   /* For each level (except not the global one),
 193       a chain of BLOCK nodes for all the levels
 194       that were entered and exited one level down.  */
 195   tree blocks;
 196
 197   /* The entity (namespace, class, function) the scope of which this
 198       binding contour corresponds to.  Otherwise NULL.  */
 199   tree this_entity;
 200
 201   /* The binding level which this one is contained in (inherits from).  */
 202   cp_binding_level *level_chain;
 203
 204   /* STATEMENT_LIST for statements in this binding contour.
 205       Only used at present for SK_CLEANUP temporary bindings.  */
 206   tree statement_list;
 207
 208   /* Binding depth at which this level began.  */
 209   int binding_depth;
 210
 211   /* The kind of scope that this object represents.  However, a
 212       SK_TEMPLATE_SPEC scope is represented with KIND set to
 213       SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true.  */
 214   ENUM_BITFIELD (scope_kind) kind : 4;
 215
 216   /* True if this scope is an SK_TEMPLATE_SPEC scope.  This field is
 217       only valid if KIND == SK_TEMPLATE_PARMS.  */
 218   BOOL_BITFIELD explicit_spec_p : 1;
 219
 220   /* true means make a BLOCK for this level regardless of all else.  */
 221   unsigned keep : 1;
 222
 223   /* Nonzero if this level can safely have additional
 224       cleanup-needing variables added to it.  */
 225   unsigned more_cleanups_ok : 1;
 226   unsigned have_cleanups : 1;
 227
 228   /* Transient state set if this scope is of sk_class kind
 229      and is in the process of defining 'this_entity'.  Reset
 230      on leaving the class definition to allow for the scope
 231      to be subsequently re-used as a non-defining scope for
 232      'this_entity'.  */
 233   unsigned defining_class_p : 1;
 234
 235   /* true for SK_FUNCTION_PARMS of immediate functions.  */
 236   unsigned immediate_fn_ctx_p : 1;
 237
 238   /* 22 bits left to fill a 32-bit word.  */
 239 };
 240
 241 /* The binding level currently in effect.  */
 242
 243 #define current_binding_level                   \
 244   (*(cfun && cp_function_chain && cp_function_chain->bindings \
 245    ? &cp_function_chain->bindings               \
 246    : &scope_chain->bindings))
 247
 248 /* The binding level of the current class, if any.  */
 249
 250 #define class_binding_level scope_chain->class_bindings
 251
 252 /* True if SCOPE designates the global scope binding contour.  */
 253 #define global_scope_p(SCOPE) \
 254   ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
 255
 256 extern cp_binding_level *leave_scope (void);
 257 extern bool kept_level_p (void);
 258 extern bool global_bindings_p (void);
 259 extern bool toplevel_bindings_p (void);
 260 extern bool namespace_bindings_p (void);
 261 extern bool local_bindings_p (void);
 262 extern bool template_parm_scope_p (void);
 263 extern scope_kind innermost_scope_kind (void);
 264 extern cp_binding_level *begin_scope (scope_kind, tree);
 265 extern void print_binding_stack (void);
 266 extern void pop_everything (void);
 267 extern void keep_next_level (bool);
 268 extern bool is_ancestor (tree ancestor, tree descendant);
 269 extern bool is_nested_namespace (tree parent, tree descendant,
 270                                  bool inline_only = false);
 271 extern tree push_scope (tree);
 272 extern void pop_scope (tree);
 273 extern tree push_inner_scope (tree);
 274 extern void pop_inner_scope (tree, tree);
 275 extern void push_binding_level (cp_binding_level *);
 276 \f
 277 extern bool handle_namespace_attrs (tree, tree);
 278 extern void pushlevel_class (void);
 279 extern void poplevel_class (void);
 280
 281 /* What kind of scopes name lookup looks in.  An enum class so we
 282    don't accidentally mix integers.  */
 283 enum class LOOK_where
 284 {
 285   BLOCK = 1 << 0,  /* Consider block scopes.  */
 286   CLASS = 1 << 1,  /* Consider class scopes.  */
 287   NAMESPACE = 1 << 2,  /* Consider namespace scopes.  */
 288
 289   ALL = BLOCK | CLASS | NAMESPACE,
 290   BLOCK_NAMESPACE = BLOCK | NAMESPACE,
 291   CLASS_NAMESPACE = CLASS | NAMESPACE,
 292 };
 293 constexpr LOOK_where operator| (LOOK_where a, LOOK_where b)
 294 {
 295   return LOOK_where (unsigned (a) | unsigned (b));
 296 }
 297 constexpr LOOK_where operator& (LOOK_where a, LOOK_where b)
 298 {
 299   return LOOK_where (unsigned (a) & unsigned (b));
 300 }
 301
 302 enum class LOOK_want
 303 {
 304   NORMAL = 0,  /* Normal lookup -- non-types can hide implicit types.  */
 305   TYPE = 1 << 1,  /* We only want TYPE_DECLS.  */
 306   NAMESPACE = 1 << 2,  /* We only want NAMESPACE_DECLS.  */
 307
 308   HIDDEN_FRIEND = 1 << 3, /* See hidden friends.  */
 309   HIDDEN_LAMBDA = 1 << 4,  /* See lambda-ignored entities.  */
 310
 311   TYPE_NAMESPACE = TYPE | NAMESPACE,  /* Either NAMESPACE or TYPE.  */
 312 };
 313 constexpr LOOK_want operator| (LOOK_want a, LOOK_want b)
 314 {
 315   return LOOK_want (unsigned (a) | unsigned (b));
 316 }
 317 constexpr LOOK_want operator& (LOOK_want a, LOOK_want b)
 318 {
 319   return LOOK_want (unsigned (a) & unsigned (b));
 320 }
 321
 322 extern tree lookup_name (tree, LOOK_where, LOOK_want = LOOK_want::NORMAL);
 323 /* Also declared in c-family/c-common.h.  */
 324 extern tree lookup_name (tree name);
 325 inline tree lookup_name (tree name, LOOK_want want)
 326 {
 327   return lookup_name (name, LOOK_where::ALL, want);
 328 }
 329
 330 extern tree lookup_type_scope (tree, tag_scope);
 331 extern tree get_namespace_binding (tree ns, tree id);
 332 extern void set_global_binding (tree decl);
 333 inline tree get_global_binding (tree id)
 334 {
 335   return get_namespace_binding (NULL_TREE, id);
 336 }
 337 extern tree lookup_qualified_name (tree scope, tree name,
 338                                    LOOK_want = LOOK_want::NORMAL,
 339                                    bool = true);
 340 extern tree lookup_qualified_name (tree scope, const char *name,
 341                                    LOOK_want = LOOK_want::NORMAL,
 342                                    bool = true);
 343 extern bool is_local_extern (tree);
 344 extern bool pushdecl_class_level (tree);
 345 extern tree pushdecl_namespace_level (tree, bool);
 346 extern bool push_class_level_binding (tree, tree);
 347 extern tree get_local_decls ();
 348 extern int function_parm_depth (void);
 349 extern tree cp_namespace_decls (tree);
 350 extern void set_decl_namespace (tree, tree, bool);
 351 extern void push_decl_namespace (tree);
 352 extern void pop_decl_namespace (void);
 353 extern void do_namespace_alias (tree, tree);
 354 extern tree do_class_using_decl (tree, tree);
 355 extern tree lookup_arg_dependent (tree, tree, vec<tree, va_gc> *);
 356 extern tree search_anon_aggr (tree, tree, bool = false);
 357 extern tree get_class_binding_direct (tree, tree, bool want_type = false);
 358 extern tree get_class_binding (tree, tree, bool want_type = false);
 359 extern tree *find_member_slot (tree klass, tree name);
 360 extern tree *add_member_slot (tree klass, tree name);
 361 extern void resort_type_member_vec (void *, void *,
 362                                     gt_pointer_operator, void *);
 363 extern void set_class_bindings (tree, unsigned extra = 0);
 364 extern void insert_late_enum_def_bindings (tree, tree);
 365 extern tree innermost_non_namespace_value (tree);
 366 extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
 367 extern void cp_emit_debug_info_for_using (tree, tree);
 368
 369 extern void finish_nonmember_using_decl (tree scope, tree name);
 370 extern void finish_using_directive (tree target, tree attribs);
 371 extern tree pushdecl (tree, bool is_friend = false);
 372 extern tree pushdecl_outermost_localscope (tree);
 373 extern tree pushdecl_top_level (tree, bool is_friend = false);
 374 extern tree pushdecl_top_level_and_finish (tree, tree);
 375 extern tree pushtag (tree, tree, tag_scope);
 376 extern int push_namespace (tree, bool make_inline = false);
 377 extern void pop_namespace (void);
 378 extern void push_nested_namespace (tree);
 379 extern void pop_nested_namespace (tree);
 380 extern void push_to_top_level (void);
 381 extern void pop_from_top_level (void);
 382 extern void maybe_save_operator_binding (tree);
 383 extern void push_operator_bindings (void);
 384 extern void discard_operator_bindings (tree);
 385
 386 #endif /* GCC_CP_NAME_LOOKUP_H */