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 | operator tree & () |
83 | { |
84 | gcc_checking_assert (!is_lazy ()); |
85 | return u.binding; |
86 | } |
87 | binding_slot &operator= (tree t) |
88 | { |
89 | u.binding = t; |
90 | return *this; |
91 | } |
92 | bool is_lazy () const |
93 | { |
94 | return bool (uintptr_t (u.binding) & 1); |
95 | } |
96 | void set_lazy (unsigned snum) |
97 | { |
98 | gcc_checking_assert (!u.binding); |
99 | u.binding = tree (uintptr_t ((snum << 1) | 1)); |
100 | } |
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 | unsigned get_lazy () const |
107 | { |
108 | gcc_checking_assert (is_lazy ()); |
109 | 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 | /* True for artificial blocks which should be ignored when finding |
314 | parent scope. */ |
315 | unsigned artificial : 1; |
316 | |
317 | /* 21 bits left to fill a 32-bit word. */ |
318 | }; |
319 | |
320 | /* The binding level currently in effect. */ |
321 | |
322 | #define current_binding_level \ |
323 | (*(cfun && cp_function_chain && cp_function_chain->bindings \ |
324 | ? &cp_function_chain->bindings \ |
325 | : &scope_chain->bindings)) |
326 | |
327 | /* The binding level of the current class, if any. */ |
328 | |
329 | #define class_binding_level scope_chain->class_bindings |
330 | |
331 | /* True if SCOPE designates the global scope binding contour. */ |
332 | #define global_scope_p(SCOPE) \ |
333 | ((SCOPE) == NAMESPACE_LEVEL (global_namespace)) |
334 | |
335 | extern cp_binding_level *leave_scope (void); |
336 | extern bool kept_level_p (void); |
337 | extern bool global_bindings_p (void); |
338 | extern bool toplevel_bindings_p (void); |
339 | extern bool namespace_bindings_p (void); |
340 | extern bool local_bindings_p (void); |
341 | extern bool template_parm_scope_p (void); |
342 | extern scope_kind innermost_scope_kind (void); |
343 | extern cp_binding_level *begin_scope (scope_kind, tree); |
344 | extern void print_binding_stack (void); |
345 | extern void pop_everything (void); |
346 | extern void keep_next_level (bool); |
347 | extern bool is_ancestor (tree ancestor, tree descendant); |
348 | extern bool is_nested_namespace (tree parent, tree descendant, |
349 | bool inline_only = false); |
350 | extern tree push_scope (tree); |
351 | extern void pop_scope (tree); |
352 | extern tree push_inner_scope (tree); |
353 | extern void pop_inner_scope (tree, tree); |
354 | extern void push_binding_level (cp_binding_level *); |
355 | |
356 | extern bool handle_namespace_attrs (tree, tree); |
357 | extern void pushlevel_class (void); |
358 | extern void poplevel_class (void); |
359 | |
360 | /* What kind of scopes name lookup looks in. An enum class so we |
361 | don't accidentally mix integers. */ |
362 | enum class LOOK_where |
363 | { |
364 | BLOCK = 1 << 0, /* Consider block scopes. */ |
365 | CLASS = 1 << 1, /* Consider class scopes. */ |
366 | NAMESPACE = 1 << 2, /* Consider namespace scopes. */ |
367 | |
368 | ALL = BLOCK | CLASS | NAMESPACE, |
369 | BLOCK_NAMESPACE = BLOCK | NAMESPACE, |
370 | CLASS_NAMESPACE = CLASS | NAMESPACE, |
371 | }; |
372 | constexpr LOOK_where operator| (LOOK_where a, LOOK_where b) |
373 | { |
374 | return LOOK_where (unsigned (a) | unsigned (b)); |
375 | } |
376 | constexpr LOOK_where operator& (LOOK_where a, LOOK_where b) |
377 | { |
378 | return LOOK_where (unsigned (a) & unsigned (b)); |
379 | } |
380 | |
381 | enum class LOOK_want |
382 | { |
383 | NORMAL = 0, /* Normal lookup -- non-types can hide implicit types. */ |
384 | TYPE = 1 << 1, /* We only want TYPE_DECLS. */ |
385 | NAMESPACE = 1 << 2, /* We only want NAMESPACE_DECLS. */ |
386 | |
387 | HIDDEN_FRIEND = 1 << 3, /* See hidden friends. */ |
388 | HIDDEN_LAMBDA = 1 << 4, /* See lambda-ignored entities. */ |
389 | |
390 | TYPE_NAMESPACE = TYPE | NAMESPACE, /* Either NAMESPACE or TYPE. */ |
391 | }; |
392 | constexpr LOOK_want operator| (LOOK_want a, LOOK_want b) |
393 | { |
394 | return LOOK_want (unsigned (a) | unsigned (b)); |
395 | } |
396 | constexpr LOOK_want operator& (LOOK_want a, LOOK_want b) |
397 | { |
398 | return LOOK_want (unsigned (a) & unsigned (b)); |
399 | } |
400 | |
401 | extern tree lookup_name (tree, LOOK_where, LOOK_want = LOOK_want::NORMAL); |
402 | /* Also declared in c-family/c-common.h. */ |
403 | extern tree lookup_name (tree name); |
404 | inline tree lookup_name (tree name, LOOK_want want) |
405 | { |
406 | return lookup_name (name, LOOK_where::ALL, want); |
407 | } |
408 | |
409 | enum class TAG_how |
410 | { |
411 | CURRENT_ONLY = 0, // Look and insert only in current scope |
412 | |
413 | GLOBAL = 1, // Unqualified lookup, innermost-non-class insertion |
414 | |
415 | INNERMOST_NON_CLASS = 2, // Look and insert only into |
416 | // innermost-non-class |
417 | |
418 | HIDDEN_FRIEND = 3, // As INNERMOST_NON_CLASS, but hide it |
419 | }; |
420 | |
421 | extern tree lookup_elaborated_type (tree, TAG_how); |
422 | extern tree get_namespace_binding (tree ns, tree id); |
423 | extern void set_global_binding (tree decl); |
424 | inline tree get_global_binding (tree id) |
425 | { |
426 | return get_namespace_binding (NULL_TREE, id); |
427 | } |
428 | extern tree lookup_qualified_name (tree scope, tree name, |
429 | LOOK_want = LOOK_want::NORMAL, |
430 | bool = true); |
431 | extern tree lookup_qualified_name (tree scope, const char *name, |
432 | LOOK_want = LOOK_want::NORMAL, |
433 | bool = true); |
434 | extern bool pushdecl_class_level (tree); |
435 | extern tree pushdecl_namespace_level (tree, bool hiding = false); |
436 | extern bool push_class_level_binding (tree, tree); |
437 | extern tree get_local_decls (); |
438 | extern int function_parm_depth (void); |
439 | extern tree cp_namespace_decls (tree); |
440 | extern void set_decl_namespace (tree, tree, bool); |
441 | extern void push_decl_namespace (tree); |
442 | extern void pop_decl_namespace (void); |
443 | extern void do_namespace_alias (tree, tree); |
444 | extern tree do_class_using_decl (tree, tree); |
445 | extern tree lookup_arg_dependent (tree, tree, vec<tree, va_gc> *); |
446 | extern tree search_anon_aggr (tree, tree, bool = false); |
447 | extern tree get_class_binding_direct (tree, tree, bool want_type = false); |
448 | extern tree get_class_binding (tree, tree, bool want_type = false); |
449 | extern tree *find_member_slot (tree klass, tree name); |
450 | extern tree *add_member_slot (tree klass, tree name); |
451 | extern void resort_type_member_vec (void *, void *, |
452 | gt_pointer_operator, void *); |
453 | extern vec<tree, va_gc> *set_class_bindings (tree, int = 0); |
454 | extern void insert_late_enum_def_bindings (tree, tree); |
455 | extern tree innermost_non_namespace_value (tree); |
456 | extern bool decl_in_scope_p (tree); |
457 | extern cxx_binding *outer_binding (tree, cxx_binding *, bool); |
458 | extern void cp_emit_debug_info_for_using (tree, tree); |
459 | |
460 | extern void finish_nonmember_using_decl (tree scope, tree name); |
461 | extern void finish_using_directive (tree target, tree attribs); |
462 | void push_local_extern_decl_alias (tree decl); |
463 | extern tree pushdecl (tree, bool hiding = false); |
464 | extern tree pushdecl_outermost_localscope (tree); |
465 | extern tree pushdecl_top_level (tree); |
466 | extern tree pushdecl_top_level_and_finish (tree, tree); |
467 | extern tree pushtag (tree, tree, TAG_how = TAG_how::CURRENT_ONLY); |
468 | extern int push_namespace (tree, bool make_inline = false); |
469 | extern void pop_namespace (void); |
470 | extern void push_nested_namespace (tree); |
471 | extern void pop_nested_namespace (tree); |
472 | extern void push_to_top_level (void); |
473 | extern void pop_from_top_level (void); |
474 | extern bool maybe_push_to_top_level (tree); |
475 | extern void maybe_pop_from_top_level (bool); |
476 | extern void push_using_decl_bindings (tree, tree); |
477 | |
478 | /* Lower level interface for modules. */ |
479 | extern tree *mergeable_namespace_slots (tree ns, tree name, bool is_attached, |
480 | tree *mvec); |
481 | extern void add_mergeable_namespace_entity (tree *slot, tree decl); |
482 | extern tree lookup_class_binding (tree ctx, tree name); |
483 | extern bool import_module_binding (tree ctx, tree name, unsigned mod, |
484 | unsigned snum); |
485 | extern bool set_module_binding (tree ctx, tree name, unsigned mod, |
486 | int mod_glob_flag, |
487 | tree value, tree type, tree visible); |
488 | extern void add_module_namespace_decl (tree ns, tree decl); |
489 | |
490 | enum WMB_Flags |
491 | { |
492 | WMB_None = 0, |
493 | WMB_Dups = 1 << 0, |
494 | WMB_Export = 1 << 1, |
495 | WMB_Using = 1 << 2, |
496 | WMB_Hidden = 1 << 3, |
497 | }; |
498 | |
499 | extern unsigned walk_module_binding (tree binding, bitmap partitions, |
500 | bool (*)(tree decl, WMB_Flags, void *data), |
501 | void *data); |
502 | extern tree add_imported_namespace (tree ctx, tree name, location_t, |
503 | unsigned module, |
504 | bool inline_p, bool visible_p); |
505 | extern const char *get_cxx_dialect_name (enum cxx_dialect dialect); |
506 | |
507 | #endif /* GCC_CP_NAME_LOOKUP_H */ |
508 | |