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
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 3, or (at your option)
10any later version.
11
12GCC is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along 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.  */
28typedef struct binding_table_s *binding_table;
29typedef struct binding_entry_s *binding_entry;
30
31/* The type of a routine repeatedly called by binding_table_foreach.  */
32typedef void (*bt_foreach_proc) (binding_entry, void *);
33
34struct 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
47extern void binding_table_foreach (binding_table, bt_foreach_proc, void *);
48extern binding_entry binding_table_find (binding_table, tree);
49
50/* Datatype that represents binding established by a declaration between
51   a name and a C++ entity.  */
52typedef struct cxx_binding cxx_binding;
53
54/* The datatype used to implement C++ scope.  */
55typedef 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
65struct 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.  */
80struct 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
89extern tree identifier_type_value (tree);
90extern void set_identifier_type_value (tree, tree);
91extern void push_binding (tree, tree, cp_binding_level*);
92extern void pop_local_binding (tree, tree);
93extern void pop_bindings_and_leave_scope (void);
94extern tree constructor_name (tree);
95extern bool constructor_name_p (tree, tree);
96
97/* The kinds of scopes we recognize.  */
98enum 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.  */
129enum 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
145struct 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
172struct 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
257extern cp_binding_level *leave_scope (void);
258extern bool kept_level_p (void);
259extern bool global_bindings_p (void);
260extern bool toplevel_bindings_p (void);
261extern bool namespace_bindings_p (void);
262extern bool local_bindings_p (void);
263extern bool template_parm_scope_p (void);
264extern scope_kind innermost_scope_kind (void);
265extern cp_binding_level *begin_scope (scope_kind, tree);
266extern void print_binding_stack	(void);
267extern void pop_everything (void);
268extern void keep_next_level (bool);
269extern bool is_ancestor (tree ancestor, tree descendant);
270extern bool is_nested_namespace (tree parent, tree descendant,
271				 bool inline_only = false);
272extern tree push_scope (tree);
273extern void pop_scope (tree);
274extern tree push_inner_scope (tree);
275extern void pop_inner_scope (tree, tree);
276extern void push_binding_level (cp_binding_level *);
277
278extern bool handle_namespace_attrs (tree, tree);
279extern void pushlevel_class (void);
280extern void poplevel_class (void);
281extern tree lookup_name_prefer_type (tree, int);
282extern tree lookup_name_real (tree, int, int, bool, int, int);
283extern tree lookup_type_scope (tree, tag_scope);
284extern tree get_namespace_binding (tree ns, tree id);
285extern void set_global_binding (tree decl);
286inline tree get_global_binding (tree id)
287{
288  return get_namespace_binding (NULL_TREE, id);
289}
290extern tree lookup_qualified_name (tree, tree, int = 0, bool = true, /*hidden*/bool = false);
291extern tree lookup_qualified_name (tree t, const char *p, int = 0, bool = true, bool = false);
292extern tree lookup_name_nonclass (tree);
293extern bool is_local_extern (tree);
294extern bool pushdecl_class_level (tree);
295extern tree pushdecl_namespace_level (tree, bool);
296extern bool push_class_level_binding (tree, tree);
297extern tree get_local_decls ();
298extern int function_parm_depth (void);
299extern tree cp_namespace_decls (tree);
300extern void set_decl_namespace (tree, tree, bool);
301extern void push_decl_namespace (tree);
302extern void pop_decl_namespace (void);
303extern void do_namespace_alias (tree, tree);
304extern tree do_class_using_decl (tree, tree);
305extern tree lookup_arg_dependent (tree, tree, vec<tree, va_gc> *);
306extern tree search_anon_aggr (tree, tree, bool = false);
307extern tree get_class_binding_direct (tree, tree, bool want_type = false);
308extern tree get_class_binding (tree, tree, bool want_type = false);
309extern tree *find_member_slot (tree klass, tree name);
310extern tree *add_member_slot (tree klass, tree name);
311extern void resort_type_member_vec (void *, void *,
312				    gt_pointer_operator, void *);
313extern void set_class_bindings (tree, unsigned extra = 0);
314extern void insert_late_enum_def_bindings (tree, tree);
315extern tree innermost_non_namespace_value (tree);
316extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
317extern void cp_emit_debug_info_for_using (tree, tree);
318
319extern void finish_nonmember_using_decl (tree scope, tree name);
320extern void finish_using_directive (tree target, tree attribs);
321extern tree pushdecl (tree, bool is_friend = false);
322extern tree pushdecl_outermost_localscope (tree);
323extern tree pushdecl_top_level (tree, bool is_friend = false);
324extern tree pushdecl_top_level_and_finish (tree, tree);
325extern tree pushtag (tree, tree, tag_scope);
326extern int push_namespace (tree, bool make_inline = false);
327extern void pop_namespace (void);
328extern void push_nested_namespace (tree);
329extern void pop_nested_namespace (tree);
330extern void push_to_top_level (void);
331extern void pop_from_top_level (void);
332extern void maybe_save_operator_binding (tree);
333extern void push_operator_bindings (void);
334extern void discard_operator_bindings (tree);
335
336#endif /* GCC_CP_NAME_LOOKUP_H */
337