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
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
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
278 extern bool handle_namespace_attrs (tree, tree);
279 extern void pushlevel_class (void);
280 extern void poplevel_class (void);
281 extern tree lookup_name_prefer_type (tree, int);
282 extern tree lookup_name_real (tree, int, int, bool, int, int);
283 extern tree lookup_type_scope (tree, tag_scope);
284 extern tree get_namespace_binding (tree ns, tree id);
285 extern void set_global_binding (tree decl);
get_global_binding(tree id)286 inline tree get_global_binding (tree id)
287 {
288 return get_namespace_binding (NULL_TREE, id);
289 }
290 extern tree lookup_qualified_name (tree, tree, int = 0, bool = true, /*hidden*/bool = false);
291 extern tree lookup_qualified_name (tree t, const char *p, int = 0, bool = true, bool = false);
292 extern tree lookup_name_nonclass (tree);
293 extern bool is_local_extern (tree);
294 extern bool pushdecl_class_level (tree);
295 extern tree pushdecl_namespace_level (tree, bool);
296 extern bool push_class_level_binding (tree, tree);
297 extern tree get_local_decls ();
298 extern int function_parm_depth (void);
299 extern tree cp_namespace_decls (tree);
300 extern void set_decl_namespace (tree, tree, bool);
301 extern void push_decl_namespace (tree);
302 extern void pop_decl_namespace (void);
303 extern void do_namespace_alias (tree, tree);
304 extern tree do_class_using_decl (tree, tree);
305 extern tree lookup_arg_dependent (tree, tree, vec<tree, va_gc> *);
306 extern tree search_anon_aggr (tree, tree, bool = false);
307 extern tree get_class_binding_direct (tree, tree, bool want_type = false);
308 extern tree get_class_binding (tree, tree, bool want_type = false);
309 extern tree *find_member_slot (tree klass, tree name);
310 extern tree *add_member_slot (tree klass, tree name);
311 extern void resort_type_member_vec (void *, void *,
312 gt_pointer_operator, void *);
313 extern void set_class_bindings (tree, unsigned extra = 0);
314 extern void insert_late_enum_def_bindings (tree, tree);
315 extern tree innermost_non_namespace_value (tree);
316 extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
317 extern void cp_emit_debug_info_for_using (tree, tree);
318
319 extern void finish_nonmember_using_decl (tree scope, tree name);
320 extern void finish_using_directive (tree target, tree attribs);
321 extern tree pushdecl (tree, bool is_friend = false);
322 extern tree pushdecl_outermost_localscope (tree);
323 extern tree pushdecl_top_level (tree, bool is_friend = false);
324 extern tree pushdecl_top_level_and_finish (tree, tree);
325 extern tree pushtag (tree, tree, tag_scope);
326 extern int push_namespace (tree, bool make_inline = false);
327 extern void pop_namespace (void);
328 extern void push_nested_namespace (tree);
329 extern void pop_nested_namespace (tree);
330 extern void push_to_top_level (void);
331 extern void pop_from_top_level (void);
332 extern void maybe_save_operator_binding (tree);
333 extern void push_operator_bindings (void);
334 extern void discard_operator_bindings (tree);
335
336 #endif /* GCC_CP_NAME_LOOKUP_H */
337