Line data Source code
1 : /* Declarations for -*- C++ -*- name lookup routines.
2 : Copyright (C) 2003-2023 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 :
27 : /* The datatype used to implement C++ scope. */
28 : struct cp_binding_level;
29 :
30 : /* Nonzero if this binding is for a local scope, as opposed to a class
31 : or namespace scope. */
32 : #define LOCAL_BINDING_P(NODE) ((NODE)->is_local)
33 :
34 : /* True if NODE->value is from a base class of the class which is
35 : currently being defined. */
36 : #define INHERITED_VALUE_BINDING_P(NODE) ((NODE)->value_is_inherited)
37 :
38 : /* The IMPLICIT_TYPEDEF is hidden from ordinary name lookup (it was
39 : injected via a local class's friend decl). The typdef may be in the
40 : VALUE or the TYPE slot. We do not get the situation where the
41 : value and type slots are both filled and both hidden. */
42 : #define HIDDEN_TYPE_BINDING_P(NODE) ((NODE)->type_is_hidden)
43 :
44 : /* Datatype that represents binding established by a declaration between
45 : a name and a C++ entity. */
46 : struct GTY(()) cxx_binding {
47 : /* Link to chain together various bindings for this name. */
48 : cxx_binding *previous;
49 : /* The non-type entity this name is bound to. */
50 : tree value;
51 : /* The type entity this name is bound to. */
52 : tree type;
53 : /* The scope at which this binding was made. */
54 : cp_binding_level *scope;
55 :
56 : bool value_is_inherited : 1;
57 : bool is_local : 1;
58 : bool type_is_hidden : 1;
59 : };
60 :
61 : /* Datatype used to temporarily save C++ bindings (for implicit
62 : instantiations purposes and like). Implemented in decl.cc. */
63 : struct GTY(()) cxx_saved_binding {
64 : /* The name of the current binding. */
65 : tree identifier;
66 : /* The binding we're saving. */
67 : cxx_binding *binding;
68 : tree real_type_value;
69 : };
70 :
71 : /* To support lazy module loading, we squirrel away a section number
72 : (and a couple of flags) in the binding slot of unloaded bindings.
73 : We rely on pointers being aligned and setting the bottom bit to
74 : mark a lazy value. GTY doesn't like an array of union, so we have
75 : a containing struct. */
76 :
77 : struct GTY(()) binding_slot {
78 : union GTY((desc ("%1.is_lazy ()"))) binding_slot_lazy {
79 : tree GTY((tag ("false"))) binding;
80 : } u;
81 :
82 2172414 : operator tree & ()
83 : {
84 0 : gcc_checking_assert (!is_lazy ());
85 2172414 : return u.binding;
86 : }
87 2428525 : binding_slot &operator= (tree t)
88 : {
89 2428525 : u.binding = t;
90 2428525 : return *this;
91 : }
92 7076076 : bool is_lazy () const
93 : {
94 7059186 : return bool (uintptr_t (u.binding) & 1);
95 : }
96 1667003 : void set_lazy (unsigned snum)
97 : {
98 1667003 : gcc_checking_assert (!u.binding);
99 1667003 : u.binding = tree (uintptr_t ((snum << 1) | 1));
100 1667003 : }
101 : void or_lazy (unsigned snum)
102 : {
103 : gcc_checking_assert (is_lazy ());
104 : u.binding = tree (uintptr_t (u.binding) | (snum << 1));
105 : }
106 16890 : unsigned get_lazy () const
107 : {
108 16890 : gcc_checking_assert (is_lazy ());
109 16890 : return unsigned (uintptr_t (u.binding) >> 1);
110 : }
111 : };
112 :
113 : /* Bindings for modules are held in a sparse array. There is always a
114 : current TU slot, others are allocated as needed. By construction
115 : of the importing mechanism we only ever need to append to the
116 : array. Rather than have straight index/slot tuples, we bunch them
117 : up for greater packing.
118 :
119 : The cluster representation packs well on a 64-bit system. */
120 :
121 : #define BINDING_VECTOR_SLOTS_PER_CLUSTER 2
122 : struct binding_index {
123 : unsigned short base;
124 : unsigned short span;
125 : };
126 :
127 : struct GTY(()) binding_cluster
128 : {
129 : binding_index GTY((skip)) indices[BINDING_VECTOR_SLOTS_PER_CLUSTER];
130 : binding_slot slots[BINDING_VECTOR_SLOTS_PER_CLUSTER];
131 : };
132 :
133 : /* These two fields overlay lang flags. So don't use those. */
134 : #define BINDING_VECTOR_ALLOC_CLUSTERS(NODE) \
135 : (BINDING_VECTOR_CHECK (NODE)->base.u.dependence_info.clique)
136 : #define BINDING_VECTOR_NUM_CLUSTERS(NODE) \
137 : (BINDING_VECTOR_CHECK (NODE)->base.u.dependence_info.base)
138 : #define BINDING_VECTOR_CLUSTER_BASE(NODE) \
139 : (((tree_binding_vec *)BINDING_VECTOR_CHECK (NODE))->vec)
140 : #define BINDING_VECTOR_CLUSTER_LAST(NODE) \
141 : (&BINDING_VECTOR_CLUSTER (NODE, BINDING_VECTOR_NUM_CLUSTERS (NODE) - 1))
142 : #define BINDING_VECTOR_CLUSTER(NODE,IX) \
143 : (((tree_binding_vec *)BINDING_VECTOR_CHECK (NODE))->vec[IX])
144 :
145 : struct GTY(()) tree_binding_vec {
146 : struct tree_base base;
147 : tree name;
148 : binding_cluster GTY((length ("%h.base.u.dependence_info.base"))) vec[1];
149 : };
150 :
151 : /* The name of a module vector. */
152 : #define BINDING_VECTOR_NAME(NODE) \
153 : (((tree_binding_vec *)BINDING_VECTOR_CHECK (NODE))->name)
154 :
155 : /* tree_binding_vec does uses base.u.dependence_info.base field for
156 : length. It does not have lang_flag etc available! */
157 :
158 : /* These two flags note if a module-vector contains deduplicated
159 : bindings (i.e. multiple declarations in different imports). */
160 : /* This binding contains duplicate references to a global module
161 : entity. */
162 : #define BINDING_VECTOR_GLOBAL_DUPS_P(NODE) \
163 : (BINDING_VECTOR_CHECK (NODE)->base.static_flag)
164 : /* This binding contains duplicate references to a partioned module
165 : entity. */
166 : #define BINDING_VECTOR_PARTITION_DUPS_P(NODE) \
167 : (BINDING_VECTOR_CHECK (NODE)->base.volatile_flag)
168 :
169 : /* These two flags indicate the provenence of the bindings on this
170 : particular vector slot. We can of course determine this from slot
171 : number, but that's a relatively expensive lookup. This avoids
172 : that when iterating. */
173 : /* This slot is part of the global module (a header unit). */
174 : #define MODULE_BINDING_GLOBAL_P(NODE) \
175 : (OVERLOAD_CHECK (NODE)->base.static_flag)
176 : /* This slot is part of the current module (a partition or primary). */
177 : #define MODULE_BINDING_PARTITION_P(NODE) \
178 : (OVERLOAD_CHECK (NODE)->base.volatile_flag)
179 :
180 : extern void set_identifier_type_value (tree, tree);
181 : extern void push_binding (tree, tree, cp_binding_level*);
182 : extern void pop_local_binding (tree, tree);
183 : extern void pop_bindings_and_leave_scope (void);
184 : extern tree constructor_name (tree);
185 : extern bool constructor_name_p (tree, tree);
186 :
187 : /* The kinds of scopes we recognize. */
188 : enum scope_kind {
189 : sk_block = 0, /* An ordinary block scope. This enumerator must
190 : have the value zero because "cp_binding_level"
191 : is initialized by using "memset" to set the
192 : contents to zero, and the default scope kind
193 : is "sk_block". */
194 : sk_cleanup, /* A scope for (pseudo-)scope for cleanup. It is
195 : pseudo in that it is transparent to name lookup
196 : activities. */
197 : sk_try, /* A try-block. */
198 : sk_catch, /* A catch-block. */
199 : sk_for, /* The scope of the variable declared in a
200 : init-statement. */
201 : sk_cond, /* The scope of the variable declared in the condition
202 : of an if or switch statement. */
203 : sk_stmt_expr, /* GNU statement expression block. */
204 : sk_function_parms, /* The scope containing function parameters. */
205 : sk_class, /* The scope containing the members of a class. */
206 : sk_scoped_enum, /* The scope containing the enumerators of a C++11
207 : scoped enumeration. */
208 : sk_namespace, /* The scope containing the members of a
209 : namespace, including the global scope. */
210 : sk_template_parms, /* A scope for template parameters. */
211 : sk_template_spec, /* Like sk_template_parms, but for an explicit
212 : specialization. Since, by definition, an
213 : explicit specialization is introduced by
214 : "template <>", this scope is always empty. */
215 : sk_transaction, /* A synchronized or atomic statement. */
216 : sk_omp /* An OpenMP structured block. */
217 : };
218 :
219 : struct GTY(()) cp_class_binding {
220 : cxx_binding *base;
221 : /* The bound name. */
222 : tree identifier;
223 : };
224 :
225 : /* For each binding contour we allocate a binding_level structure
226 : which records the names defined in that contour.
227 : Contours include:
228 : 0) the global one
229 : 1) one for each function definition,
230 : where internal declarations of the parameters appear.
231 : 2) one for each compound statement,
232 : to record its declarations.
233 :
234 : The current meaning of a name can be found by searching the levels
235 : from the current one out to the global one.
236 :
237 : Off to the side, may be the class_binding_level. This exists only
238 : to catch class-local declarations. It is otherwise nonexistent.
239 :
240 : Also there may be binding levels that catch cleanups that must be
241 : run when exceptions occur. Thus, to see whether a name is bound in
242 : the current scope, it is not enough to look in the
243 : CURRENT_BINDING_LEVEL. You should use lookup_name_current_level
244 : instead. */
245 :
246 : struct GTY(()) cp_binding_level {
247 : /* A chain of _DECL nodes for all variables, constants, functions,
248 : and typedef types. These are in the reverse of the order
249 : supplied. There may be OVERLOADs on this list, too, but they
250 : are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD. */
251 : tree names;
252 :
253 : /* Using directives. */
254 : vec<tree, va_gc> *using_directives;
255 :
256 : /* For the binding level corresponding to a class, the entities
257 : declared in the class or its base classes. */
258 : vec<cp_class_binding, va_gc> *class_shadowed;
259 :
260 : /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and
261 : is used for all binding levels. The TREE_PURPOSE is the name of
262 : the entity, the TREE_TYPE is the associated type. In addition
263 : the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered
264 : the class. */
265 : tree type_shadowed;
266 :
267 : /* For each level (except not the global one),
268 : a chain of BLOCK nodes for all the levels
269 : that were entered and exited one level down. */
270 : tree blocks;
271 :
272 : /* The entity (namespace, class, function) the scope of which this
273 : binding contour corresponds to. Otherwise NULL. */
274 : tree this_entity;
275 :
276 : /* The binding level which this one is contained in (inherits from). */
277 : cp_binding_level *level_chain;
278 :
279 : /* STATEMENT_LIST for statements in this binding contour.
280 : Only used at present for SK_CLEANUP temporary bindings. */
281 : tree statement_list;
282 :
283 : /* Binding depth at which this level began. */
284 : int binding_depth;
285 :
286 : /* The kind of scope that this object represents. However, a
287 : SK_TEMPLATE_SPEC scope is represented with KIND set to
288 : SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true. */
289 : ENUM_BITFIELD (scope_kind) kind : 4;
290 :
291 : /* True if this scope is an SK_TEMPLATE_SPEC scope. This field is
292 : only valid if KIND == SK_TEMPLATE_PARMS. */
293 : BOOL_BITFIELD explicit_spec_p : 1;
294 :
295 : /* true means make a BLOCK for this level regardless of all else. */
296 : unsigned keep : 1;
297 :
298 : /* Nonzero if this level can safely have additional
299 : cleanup-needing variables added to it. */
300 : unsigned more_cleanups_ok : 1;
301 : unsigned have_cleanups : 1;
302 :
303 : /* Transient state set if this scope is of sk_class kind
304 : and is in the process of defining 'this_entity'. Reset
305 : on leaving the class definition to allow for the scope
306 : to be subsequently re-used as a non-defining scope for
307 : 'this_entity'. */
308 : unsigned defining_class_p : 1;
309 :
310 : /* True for SK_FUNCTION_PARMS of a requires-expression. */
311 : unsigned requires_expression: 1;
312 :
313 : /* 22 bits left to fill a 32-bit word. */
314 : };
315 :
316 : /* The binding level currently in effect. */
317 :
318 : #define current_binding_level \
319 : (*(cfun && cp_function_chain && cp_function_chain->bindings \
320 : ? &cp_function_chain->bindings \
321 : : &scope_chain->bindings))
322 :
323 : /* The binding level of the current class, if any. */
324 :
325 : #define class_binding_level scope_chain->class_bindings
326 :
327 : /* True if SCOPE designates the global scope binding contour. */
328 : #define global_scope_p(SCOPE) \
329 : ((SCOPE) == NAMESPACE_LEVEL (global_namespace))
330 :
331 : extern cp_binding_level *leave_scope (void);
332 : extern bool kept_level_p (void);
333 : extern bool global_bindings_p (void);
334 : extern bool toplevel_bindings_p (void);
335 : extern bool namespace_bindings_p (void);
336 : extern bool local_bindings_p (void);
337 : extern bool template_parm_scope_p (void);
338 : extern scope_kind innermost_scope_kind (void);
339 : extern cp_binding_level *begin_scope (scope_kind, tree);
340 : extern void print_binding_stack (void);
341 : extern void pop_everything (void);
342 : extern void keep_next_level (bool);
343 : extern bool is_ancestor (tree ancestor, tree descendant);
344 : extern bool is_nested_namespace (tree parent, tree descendant,
345 : bool inline_only = false);
346 : extern tree push_scope (tree);
347 : extern void pop_scope (tree);
348 : extern tree push_inner_scope (tree);
349 : extern void pop_inner_scope (tree, tree);
350 : extern void push_binding_level (cp_binding_level *);
351 :
352 : extern bool handle_namespace_attrs (tree, tree);
353 : extern void pushlevel_class (void);
354 : extern void poplevel_class (void);
355 :
356 : /* What kind of scopes name lookup looks in. An enum class so we
357 : don't accidentally mix integers. */
358 : enum class LOOK_where
359 : {
360 : BLOCK = 1 << 0, /* Consider block scopes. */
361 : CLASS = 1 << 1, /* Consider class scopes. */
362 : NAMESPACE = 1 << 2, /* Consider namespace scopes. */
363 :
364 : ALL = BLOCK | CLASS | NAMESPACE,
365 : BLOCK_NAMESPACE = BLOCK | NAMESPACE,
366 : CLASS_NAMESPACE = CLASS | NAMESPACE,
367 : };
368 : constexpr LOOK_where operator| (LOOK_where a, LOOK_where b)
369 : {
370 : return LOOK_where (unsigned (a) | unsigned (b));
371 : }
372 : constexpr LOOK_where operator& (LOOK_where a, LOOK_where b)
373 : {
374 : return LOOK_where (unsigned (a) & unsigned (b));
375 : }
376 :
377 : enum class LOOK_want
378 : {
379 : NORMAL = 0, /* Normal lookup -- non-types can hide implicit types. */
380 : TYPE = 1 << 1, /* We only want TYPE_DECLS. */
381 : NAMESPACE = 1 << 2, /* We only want NAMESPACE_DECLS. */
382 :
383 : HIDDEN_FRIEND = 1 << 3, /* See hidden friends. */
384 : HIDDEN_LAMBDA = 1 << 4, /* See lambda-ignored entities. */
385 :
386 : TYPE_NAMESPACE = TYPE | NAMESPACE, /* Either NAMESPACE or TYPE. */
387 : };
388 : constexpr LOOK_want operator| (LOOK_want a, LOOK_want b)
389 : {
390 : return LOOK_want (unsigned (a) | unsigned (b));
391 : }
392 : constexpr LOOK_want operator& (LOOK_want a, LOOK_want b)
393 : {
394 : return LOOK_want (unsigned (a) & unsigned (b));
395 : }
396 :
397 : extern tree lookup_name (tree, LOOK_where, LOOK_want = LOOK_want::NORMAL);
398 : /* Also declared in c-family/c-common.h. */
399 : extern tree lookup_name (tree name);
400 2450667230 : inline tree lookup_name (tree name, LOOK_want want)
401 : {
402 2450667230 : return lookup_name (name, LOOK_where::ALL, want);
403 : }
404 :
405 : enum class TAG_how
406 : {
407 : CURRENT_ONLY = 0, // Look and insert only in current scope
408 :
409 : GLOBAL = 1, // Unqualified lookup, innermost-non-class insertion
410 :
411 : INNERMOST_NON_CLASS = 2, // Look and insert only into
412 : // innermost-non-class
413 :
414 : HIDDEN_FRIEND = 3, // As INNERMOST_NON_CLASS, but hide it
415 : };
416 :
417 : extern tree lookup_elaborated_type (tree, TAG_how);
418 : extern tree get_namespace_binding (tree ns, tree id);
419 : extern void set_global_binding (tree decl);
420 3961445 : inline tree get_global_binding (tree id)
421 : {
422 3955415 : return get_namespace_binding (NULL_TREE, id);
423 : }
424 : extern tree lookup_qualified_name (tree scope, tree name,
425 : LOOK_want = LOOK_want::NORMAL,
426 : bool = true);
427 : extern tree lookup_qualified_name (tree scope, const char *name,
428 : LOOK_want = LOOK_want::NORMAL,
429 : bool = true);
430 : extern bool pushdecl_class_level (tree);
431 : extern tree pushdecl_namespace_level (tree, bool hiding = false);
432 : extern bool push_class_level_binding (tree, tree);
433 : extern tree get_local_decls ();
434 : extern int function_parm_depth (void);
435 : extern tree cp_namespace_decls (tree);
436 : extern void set_decl_namespace (tree, tree, bool);
437 : extern void push_decl_namespace (tree);
438 : extern void pop_decl_namespace (void);
439 : extern void do_namespace_alias (tree, tree);
440 : extern tree do_class_using_decl (tree, tree);
441 : extern tree lookup_arg_dependent (tree, tree, vec<tree, va_gc> *);
442 : extern tree search_anon_aggr (tree, tree, bool = false);
443 : extern tree get_class_binding_direct (tree, tree, bool want_type = false);
444 : extern tree get_class_binding (tree, tree, bool want_type = false);
445 : extern tree *find_member_slot (tree klass, tree name);
446 : extern tree *add_member_slot (tree klass, tree name);
447 : extern void resort_type_member_vec (void *, void *,
448 : gt_pointer_operator, void *);
449 : extern vec<tree, va_gc> *set_class_bindings (tree, int extra = 0);
450 : extern void insert_late_enum_def_bindings (tree, tree);
451 : extern tree innermost_non_namespace_value (tree);
452 : extern bool decl_in_scope_p (tree);
453 : extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
454 : extern void cp_emit_debug_info_for_using (tree, tree);
455 :
456 : extern void finish_nonmember_using_decl (tree scope, tree name);
457 : extern void finish_using_directive (tree target, tree attribs);
458 : void push_local_extern_decl_alias (tree decl);
459 : extern tree pushdecl (tree, bool hiding = false);
460 : extern tree pushdecl_outermost_localscope (tree);
461 : extern tree pushdecl_top_level (tree);
462 : extern tree pushdecl_top_level_and_finish (tree, tree);
463 : extern tree pushtag (tree, tree, TAG_how = TAG_how::CURRENT_ONLY);
464 : extern int push_namespace (tree, bool make_inline = false);
465 : extern void pop_namespace (void);
466 : extern void push_nested_namespace (tree);
467 : extern void pop_nested_namespace (tree);
468 : extern void push_to_top_level (void);
469 : extern void pop_from_top_level (void);
470 : extern bool maybe_push_to_top_level (tree);
471 : extern void maybe_pop_from_top_level (bool);
472 : extern void push_using_decl_bindings (tree, tree);
473 :
474 : /* Lower level interface for modules. */
475 : extern tree *mergeable_namespace_slots (tree ns, tree name, bool is_attached,
476 : tree *mvec);
477 : extern void add_mergeable_namespace_entity (tree *slot, tree decl);
478 : extern tree lookup_class_binding (tree ctx, tree name);
479 : extern bool import_module_binding (tree ctx, tree name, unsigned mod,
480 : unsigned snum);
481 : extern bool set_module_binding (tree ctx, tree name, unsigned mod,
482 : int mod_glob_flag,
483 : tree value, tree type, tree visible);
484 : extern void add_module_namespace_decl (tree ns, tree decl);
485 :
486 : enum WMB_Flags
487 : {
488 : WMB_None = 0,
489 : WMB_Dups = 1 << 0,
490 : WMB_Export = 1 << 1,
491 : WMB_Using = 1 << 2,
492 : WMB_Hidden = 1 << 3,
493 : };
494 :
495 : extern unsigned walk_module_binding (tree binding, bitmap partitions,
496 : bool (*)(tree decl, WMB_Flags, void *data),
497 : void *data);
498 : extern tree add_imported_namespace (tree ctx, tree name, location_t,
499 : unsigned module,
500 : bool inline_p, bool visible_p);
501 : extern const char *get_cxx_dialect_name (enum cxx_dialect dialect);
502 :
503 : #endif /* GCC_CP_NAME_LOOKUP_H */
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