1//===- ExternalASTMerger.cpp - Merging External AST Interface ---*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the ExternalASTMerger, which vends a combination of
10// ASTs from several different ASTContext/FileManager pairs
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/AST/ASTContext.h"
15#include "clang/AST/Decl.h"
16#include "clang/AST/DeclCXX.h"
17#include "clang/AST/DeclObjC.h"
18#include "clang/AST/DeclTemplate.h"
19#include "clang/AST/ExternalASTMerger.h"
20
21using namespace clang;
22
23namespace {
24
25template <typename T> struct Source {
26 T t;
27 Source(T t) : t(t) {}
28 operator T() { return t; }
29 template <typename U = T> U &get() { return t; }
30 template <typename U = T> const U &get() const { return t; }
31 template <typename U> operator Source<U>() { return Source<U>(t); }
32};
33
34typedef std::pair<Source<NamedDecl *>, ASTImporter *> Candidate;
35
36/// For the given DC, return the DC that is safe to perform lookups on. This is
37/// the DC we actually want to work with most of the time.
38const DeclContext *CanonicalizeDC(const DeclContext *DC) {
39 if (isa<LinkageSpecDecl>(Val: DC))
40 return DC->getRedeclContext();
41 return DC;
42}
43
44Source<const DeclContext *>
45LookupSameContext(Source<TranslationUnitDecl *> SourceTU, const DeclContext *DC,
46 ASTImporter &ReverseImporter) {
47 DC = CanonicalizeDC(DC);
48 if (DC->isTranslationUnit()) {
49 return SourceTU;
50 }
51 Source<const DeclContext *> SourceParentDC =
52 LookupSameContext(SourceTU, DC: DC->getParent(), ReverseImporter);
53 if (!SourceParentDC) {
54 // If we couldn't find the parent DC in this TranslationUnit, give up.
55 return nullptr;
56 }
57 auto *ND = cast<NamedDecl>(Val: DC);
58 DeclarationName Name = ND->getDeclName();
59 auto SourceNameOrErr = ReverseImporter.Import(FromName: Name);
60 if (!SourceNameOrErr) {
61 llvm::consumeError(Err: SourceNameOrErr.takeError());
62 return nullptr;
63 }
64 Source<DeclarationName> SourceName = *SourceNameOrErr;
65 DeclContext::lookup_result SearchResult =
66 SourceParentDC.get()->lookup(Name: SourceName.get());
67
68 // There are two cases here. First, we might not find the name.
69 // We might also find multiple copies, in which case we have no
70 // guarantee that the one we wanted is the one we pick. (E.g.,
71 // if we have two specializations of the same template it is
72 // very hard to determine which is the one you want.)
73 //
74 // The Origins map fixes this problem by allowing the origin to be
75 // explicitly recorded, so we trigger that recording by returning
76 // nothing (rather than a possibly-inaccurate guess) here.
77 if (SearchResult.isSingleResult()) {
78 NamedDecl *SearchResultDecl = SearchResult.front();
79 if (isa<DeclContext>(Val: SearchResultDecl) &&
80 SearchResultDecl->getKind() == DC->getDeclKind())
81 return cast<DeclContext>(Val: SearchResultDecl)->getPrimaryContext();
82 return nullptr; // This type of lookup is unsupported
83 } else {
84 return nullptr;
85 }
86}
87
88/// A custom implementation of ASTImporter, for ExternalASTMerger's purposes.
89///
90/// There are several modifications:
91///
92/// - It enables lazy lookup (via the HasExternalLexicalStorage flag and a few
93/// others), which instructs Clang to refer to ExternalASTMerger. Also, it
94/// forces MinimalImport to true, which is necessary to make this work.
95/// - It maintains a reverse importer for use with names. This allows lookup of
96/// arbitrary names in the source context.
97/// - It updates the ExternalASTMerger's origin map as needed whenever a
98/// it sees a DeclContext.
99class LazyASTImporter : public ASTImporter {
100private:
101 ExternalASTMerger &Parent;
102 ASTImporter Reverse;
103 const ExternalASTMerger::OriginMap &FromOrigins;
104 /// @see ExternalASTMerger::ImporterSource::Temporary
105 bool TemporarySource;
106 /// Map of imported declarations back to the declarations they originated
107 /// from.
108 llvm::DenseMap<Decl *, Decl *> ToOrigin;
109 /// @see ExternalASTMerger::ImporterSource::Merger
110 ExternalASTMerger *SourceMerger;
111 llvm::raw_ostream &logs() { return Parent.logs(); }
112public:
113 LazyASTImporter(ExternalASTMerger &_Parent, ASTContext &ToContext,
114 FileManager &ToFileManager,
115 const ExternalASTMerger::ImporterSource &S,
116 std::shared_ptr<ASTImporterSharedState> SharedState)
117 : ASTImporter(ToContext, ToFileManager, S.getASTContext(),
118 S.getFileManager(),
119 /*MinimalImport=*/true, SharedState),
120 Parent(_Parent),
121 Reverse(S.getASTContext(), S.getFileManager(), ToContext, ToFileManager,
122 /*MinimalImport=*/true),
123 FromOrigins(S.getOriginMap()), TemporarySource(S.isTemporary()),
124 SourceMerger(S.getMerger()) {}
125
126 llvm::Expected<Decl *> ImportImpl(Decl *FromD) override {
127 if (!TemporarySource || !SourceMerger)
128 return ASTImporter::ImportImpl(From: FromD);
129
130 // If we get here, then this source is importing from a temporary ASTContext
131 // that also has another ExternalASTMerger attached. It could be
132 // possible that the current ExternalASTMerger and the temporary ASTContext
133 // share a common ImporterSource, which means that the temporary
134 // AST could contain declarations that were imported from a source
135 // that this ExternalASTMerger can access directly. Instead of importing
136 // such declarations from the temporary ASTContext, they should instead
137 // be directly imported by this ExternalASTMerger from the original
138 // source. This way the ExternalASTMerger can safely do a minimal import
139 // without creating incomplete declarations originated from a temporary
140 // ASTContext. If we would try to complete such declarations later on, we
141 // would fail to do so as their temporary AST could be deleted (which means
142 // that the missing parts of the minimally imported declaration in that
143 // ASTContext were also deleted).
144 //
145 // The following code tracks back any declaration that needs to be
146 // imported from the temporary ASTContext to a persistent ASTContext.
147 // Then the ExternalASTMerger tries to import from the persistent
148 // ASTContext directly by using the associated ASTImporter. If that
149 // succeeds, this ASTImporter just maps the declarations imported by
150 // the other (persistent) ASTImporter to this (temporary) ASTImporter.
151 // The steps can be visualized like this:
152 //
153 // Target AST <--- 3. Indirect import --- Persistent AST
154 // ^ of persistent decl ^
155 // | |
156 // 1. Current import 2. Tracking back to persistent decl
157 // 4. Map persistent decl |
158 // & pretend we imported. |
159 // | |
160 // Temporary AST -------------------------------'
161
162 // First, ask the ExternalASTMerger of the source where the temporary
163 // declaration originated from.
164 Decl *Persistent = SourceMerger->FindOriginalDecl(D: FromD);
165 // FromD isn't from a persistent AST, so just do a normal import.
166 if (!Persistent)
167 return ASTImporter::ImportImpl(From: FromD);
168 // Now ask the current ExternalASTMerger to try import the persistent
169 // declaration into the target.
170 ASTContext &PersistentCtx = Persistent->getASTContext();
171 ASTImporter &OtherImporter = Parent.ImporterForOrigin(OriginContext&: PersistentCtx);
172 // Check that we never end up in the current Importer again.
173 assert((&PersistentCtx != &getFromContext()) && (&OtherImporter != this) &&
174 "Delegated to same Importer?");
175 auto DeclOrErr = OtherImporter.Import(FromD: Persistent);
176 // Errors when importing the persistent decl are treated as if we
177 // had errors with importing the temporary decl.
178 if (!DeclOrErr)
179 return DeclOrErr.takeError();
180 Decl *D = *DeclOrErr;
181 // Tell the current ASTImporter that this has already been imported
182 // to prevent any further queries for the temporary decl.
183 MapImported(From: FromD, To: D);
184 return D;
185 }
186
187 /// Implements the ASTImporter interface for tracking back a declaration
188 /// to its original declaration it came from.
189 Decl *GetOriginalDecl(Decl *To) override {
190 return ToOrigin.lookup(Val: To);
191 }
192
193 /// Whenever a DeclContext is imported, ensure that ExternalASTSource's origin
194 /// map is kept up to date. Also set the appropriate flags.
195 void Imported(Decl *From, Decl *To) override {
196 ToOrigin[To] = From;
197
198 if (auto *ToDC = dyn_cast<DeclContext>(Val: To)) {
199 const bool LoggingEnabled = Parent.LoggingEnabled();
200 if (LoggingEnabled)
201 logs() << "(ExternalASTMerger*)" << (void*)&Parent
202 << " imported (DeclContext*)" << (void*)ToDC
203 << ", (ASTContext*)" << (void*)&getToContext()
204 << " from (DeclContext*)" << (void*)llvm::cast<DeclContext>(Val: From)
205 << ", (ASTContext*)" << (void*)&getFromContext()
206 << "\n";
207 Source<DeclContext *> FromDC(
208 cast<DeclContext>(Val: From)->getPrimaryContext());
209 if (auto It = FromOrigins.find(x: FromDC);
210 It != FromOrigins.end() &&
211 Parent.HasImporterForOrigin(OriginContext&: *It->second.AST)) {
212 if (LoggingEnabled)
213 logs() << "(ExternalASTMerger*)" << (void *)&Parent
214 << " forced origin (DeclContext*)" << (void *)It->second.DC
215 << ", (ASTContext*)" << (void *)It->second.AST << "\n";
216 Parent.ForceRecordOrigin(ToDC, Origin: It->second);
217 } else {
218 if (LoggingEnabled)
219 logs() << "(ExternalASTMerger*)" << (void*)&Parent
220 << " maybe recording origin (DeclContext*)" << (void*)FromDC
221 << ", (ASTContext*)" << (void*)&getFromContext()
222 << "\n";
223 Parent.MaybeRecordOrigin(ToDC, Origin: {.DC: FromDC, .AST: &getFromContext()});
224 }
225 }
226 if (auto *ToTag = dyn_cast<TagDecl>(Val: To)) {
227 ToTag->setHasExternalLexicalStorage();
228 ToTag->getPrimaryContext()->setMustBuildLookupTable();
229 assert(Parent.CanComplete(ToTag));
230 } else if (auto *ToNamespace = dyn_cast<NamespaceDecl>(Val: To)) {
231 ToNamespace->setHasExternalVisibleStorage();
232 assert(Parent.CanComplete(ToNamespace));
233 } else if (auto *ToContainer = dyn_cast<ObjCContainerDecl>(Val: To)) {
234 ToContainer->setHasExternalLexicalStorage();
235 ToContainer->getPrimaryContext()->setMustBuildLookupTable();
236 assert(Parent.CanComplete(ToContainer));
237 }
238 }
239 ASTImporter &GetReverse() { return Reverse; }
240};
241
242bool HasDeclOfSameType(ArrayRef<Candidate> Decls, const Candidate &C) {
243 if (isa<FunctionDecl>(Val: C.first.get()))
244 return false;
245 return llvm::any_of(Range&: Decls, P: [&](const Candidate &D) {
246 return C.first.get()->getKind() == D.first.get()->getKind();
247 });
248}
249
250} // end namespace
251
252ASTImporter &ExternalASTMerger::ImporterForOrigin(ASTContext &OriginContext) {
253 for (const std::unique_ptr<ASTImporter> &I : Importers)
254 if (&I->getFromContext() == &OriginContext)
255 return *I;
256 llvm_unreachable("We should have an importer for this origin!");
257}
258
259namespace {
260LazyASTImporter &LazyImporterForOrigin(ExternalASTMerger &Merger,
261 ASTContext &OriginContext) {
262 return static_cast<LazyASTImporter &>(
263 Merger.ImporterForOrigin(OriginContext));
264}
265}
266
267bool ExternalASTMerger::HasImporterForOrigin(ASTContext &OriginContext) {
268 for (const std::unique_ptr<ASTImporter> &I : Importers)
269 if (&I->getFromContext() == &OriginContext)
270 return true;
271 return false;
272}
273
274template <typename CallbackType>
275void ExternalASTMerger::ForEachMatchingDC(const DeclContext *DC,
276 CallbackType Callback) {
277 if (auto It = Origins.find(x: DC); It != Origins.end()) {
278 ExternalASTMerger::DCOrigin Origin = It->second;
279 LazyASTImporter &Importer = LazyImporterForOrigin(Merger&: *this, OriginContext&: *Origin.AST);
280 Callback(Importer, Importer.GetReverse(), Origin.DC);
281 } else {
282 bool DidCallback = false;
283 for (const std::unique_ptr<ASTImporter> &Importer : Importers) {
284 Source<TranslationUnitDecl *> SourceTU =
285 Importer->getFromContext().getTranslationUnitDecl();
286 ASTImporter &Reverse =
287 static_cast<LazyASTImporter *>(Importer.get())->GetReverse();
288 if (auto SourceDC = LookupSameContext(SourceTU, DC, ReverseImporter&: Reverse)) {
289 DidCallback = true;
290 if (Callback(*Importer, Reverse, SourceDC))
291 break;
292 }
293 }
294 if (!DidCallback && LoggingEnabled())
295 logs() << "(ExternalASTMerger*)" << (void*)this
296 << " asserting for (DeclContext*)" << (const void*)DC
297 << ", (ASTContext*)" << (void*)&Target.AST
298 << "\n";
299 assert(DidCallback && "Couldn't find a source context matching our DC");
300 }
301}
302
303void ExternalASTMerger::CompleteType(TagDecl *Tag) {
304 assert(Tag->hasExternalLexicalStorage());
305 ForEachMatchingDC(DC: Tag, Callback: [&](ASTImporter &Forward, ASTImporter &Reverse,
306 Source<const DeclContext *> SourceDC) -> bool {
307 auto *SourceTag = const_cast<TagDecl *>(cast<TagDecl>(Val: SourceDC.get()));
308 if (SourceTag->hasExternalLexicalStorage())
309 SourceTag->getASTContext().getExternalSource()->CompleteType(Tag: SourceTag);
310 if (!SourceTag->getDefinition())
311 return false;
312 Forward.MapImported(From: SourceTag, To: Tag);
313 if (llvm::Error Err = Forward.ImportDefinition(From: SourceTag))
314 llvm::consumeError(Err: std::move(Err));
315 Tag->setCompleteDefinition(SourceTag->isCompleteDefinition());
316 return true;
317 });
318}
319
320void ExternalASTMerger::CompleteType(ObjCInterfaceDecl *Interface) {
321 assert(Interface->hasExternalLexicalStorage());
322 ForEachMatchingDC(
323 DC: Interface, Callback: [&](ASTImporter &Forward, ASTImporter &Reverse,
324 Source<const DeclContext *> SourceDC) -> bool {
325 auto *SourceInterface = const_cast<ObjCInterfaceDecl *>(
326 cast<ObjCInterfaceDecl>(Val: SourceDC.get()));
327 if (SourceInterface->hasExternalLexicalStorage())
328 SourceInterface->getASTContext().getExternalSource()->CompleteType(
329 Class: SourceInterface);
330 if (!SourceInterface->getDefinition())
331 return false;
332 Forward.MapImported(From: SourceInterface, To: Interface);
333 if (llvm::Error Err = Forward.ImportDefinition(From: SourceInterface))
334 llvm::consumeError(Err: std::move(Err));
335 return true;
336 });
337}
338
339bool ExternalASTMerger::CanComplete(DeclContext *Interface) {
340 assert(Interface->hasExternalLexicalStorage() ||
341 Interface->hasExternalVisibleStorage());
342 bool FoundMatchingDC = false;
343 ForEachMatchingDC(DC: Interface,
344 Callback: [&](ASTImporter &Forward, ASTImporter &Reverse,
345 Source<const DeclContext *> SourceDC) -> bool {
346 FoundMatchingDC = true;
347 return true;
348 });
349 return FoundMatchingDC;
350}
351
352namespace {
353bool IsSameDC(const DeclContext *D1, const DeclContext *D2) {
354 if (isa<ObjCContainerDecl>(Val: D1) && isa<ObjCContainerDecl>(Val: D2))
355 return true; // There are many cases where Objective-C is ambiguous.
356 if (auto *T1 = dyn_cast<TagDecl>(Val: D1))
357 if (auto *T2 = dyn_cast<TagDecl>(Val: D2))
358 if (T1->getFirstDecl() == T2->getFirstDecl())
359 return true;
360 return D1 == D2 || D1 == CanonicalizeDC(DC: D2);
361}
362}
363
364void ExternalASTMerger::MaybeRecordOrigin(const DeclContext *ToDC,
365 DCOrigin Origin) {
366 LazyASTImporter &Importer = LazyImporterForOrigin(Merger&: *this, OriginContext&: *Origin.AST);
367 ASTImporter &Reverse = Importer.GetReverse();
368 Source<const DeclContext *> FoundFromDC =
369 LookupSameContext(SourceTU: Origin.AST->getTranslationUnitDecl(), DC: ToDC, ReverseImporter&: Reverse);
370 const bool DoRecord = !FoundFromDC || !IsSameDC(D1: FoundFromDC.get(), D2: Origin.DC);
371 if (DoRecord)
372 RecordOriginImpl(ToDC, Origin, importer&: Importer);
373 if (LoggingEnabled())
374 logs() << "(ExternalASTMerger*)" << (void*)this
375 << (DoRecord ? " decided " : " decided NOT")
376 << " to record origin (DeclContext*)" << (void*)Origin.DC
377 << ", (ASTContext*)" << (void*)&Origin.AST
378 << "\n";
379}
380
381void ExternalASTMerger::ForceRecordOrigin(const DeclContext *ToDC,
382 DCOrigin Origin) {
383 RecordOriginImpl(ToDC, Origin, importer&: ImporterForOrigin(OriginContext&: *Origin.AST));
384}
385
386void ExternalASTMerger::RecordOriginImpl(const DeclContext *ToDC, DCOrigin Origin,
387 ASTImporter &Importer) {
388 Origins[ToDC] = Origin;
389 Importer.ASTImporter::MapImported(From: cast<Decl>(Val: Origin.DC), To: const_cast<Decl*>(cast<Decl>(Val: ToDC)));
390}
391
392ExternalASTMerger::ExternalASTMerger(const ImporterTarget &Target,
393 ArrayRef<ImporterSource> Sources)
394 : LogStream(&llvm::nulls()), Target(Target) {
395 SharedState = std::make_shared<ASTImporterSharedState>(
396 args&: *Target.AST.getTranslationUnitDecl());
397 AddSources(Sources);
398}
399
400Decl *ExternalASTMerger::FindOriginalDecl(Decl *D) {
401 assert(&D->getASTContext() == &Target.AST);
402 for (const auto &I : Importers)
403 if (auto Result = I->GetOriginalDecl(To: D))
404 return Result;
405 return nullptr;
406}
407
408void ExternalASTMerger::AddSources(ArrayRef<ImporterSource> Sources) {
409 for (const ImporterSource &S : Sources) {
410 assert(&S.getASTContext() != &Target.AST);
411 // Check that the associated merger actually imports into the source AST.
412 assert(!S.getMerger() || &S.getMerger()->Target.AST == &S.getASTContext());
413 Importers.push_back(x: std::make_unique<LazyASTImporter>(
414 args&: *this, args&: Target.AST, args&: Target.FM, args: S, args&: SharedState));
415 }
416}
417
418void ExternalASTMerger::RemoveSources(ArrayRef<ImporterSource> Sources) {
419 if (LoggingEnabled())
420 for (const ImporterSource &S : Sources)
421 logs() << "(ExternalASTMerger*)" << (void *)this
422 << " removing source (ASTContext*)" << (void *)&S.getASTContext()
423 << "\n";
424 llvm::erase_if(C&: Importers,
425 P: [&Sources](std::unique_ptr<ASTImporter> &Importer) -> bool {
426 for (const ImporterSource &S : Sources) {
427 if (&Importer->getFromContext() == &S.getASTContext())
428 return true;
429 }
430 return false;
431 });
432 for (OriginMap::iterator OI = Origins.begin(), OE = Origins.end(); OI != OE; ) {
433 std::pair<const DeclContext *, DCOrigin> Origin = *OI;
434 bool Erase = false;
435 for (const ImporterSource &S : Sources) {
436 if (&S.getASTContext() == Origin.second.AST) {
437 Erase = true;
438 break;
439 }
440 }
441 if (Erase)
442 OI = Origins.erase(position: OI);
443 else
444 ++OI;
445 }
446}
447
448template <typename DeclTy>
449static bool importSpecializations(DeclTy *D, ASTImporter *Importer) {
450 for (auto *Spec : D->specializations()) {
451 auto ImportedSpecOrError = Importer->Import(Spec);
452 if (!ImportedSpecOrError) {
453 llvm::consumeError(Err: ImportedSpecOrError.takeError());
454 return true;
455 }
456 }
457 return false;
458}
459
460/// Imports specializations from template declarations that can be specialized.
461static bool importSpecializationsIfNeeded(Decl *D, ASTImporter *Importer) {
462 if (!isa<TemplateDecl>(Val: D))
463 return false;
464 if (auto *FunctionTD = dyn_cast<FunctionTemplateDecl>(Val: D))
465 return importSpecializations(D: FunctionTD, Importer);
466 else if (auto *ClassTD = dyn_cast<ClassTemplateDecl>(Val: D))
467 return importSpecializations(D: ClassTD, Importer);
468 else if (auto *VarTD = dyn_cast<VarTemplateDecl>(Val: D))
469 return importSpecializations(D: VarTD, Importer);
470 return false;
471}
472
473bool ExternalASTMerger::FindExternalVisibleDeclsByName(
474 const DeclContext *DC, DeclarationName Name,
475 const DeclContext *OriginalDC) {
476 llvm::SmallVector<NamedDecl *, 1> Decls;
477 llvm::SmallVector<Candidate, 4> Candidates;
478
479 auto FilterFoundDecl = [&Candidates](const Candidate &C) {
480 if (!HasDeclOfSameType(Decls: Candidates, C))
481 Candidates.push_back(Elt: C);
482 };
483
484 ForEachMatchingDC(DC,
485 Callback: [&](ASTImporter &Forward, ASTImporter &Reverse,
486 Source<const DeclContext *> SourceDC) -> bool {
487 auto FromNameOrErr = Reverse.Import(FromName: Name);
488 if (!FromNameOrErr) {
489 llvm::consumeError(Err: FromNameOrErr.takeError());
490 return false;
491 }
492 DeclContextLookupResult Result =
493 SourceDC.get()->lookup(Name: *FromNameOrErr);
494 for (NamedDecl *FromD : Result) {
495 FilterFoundDecl(std::make_pair(x&: FromD, y: &Forward));
496 }
497 return false;
498 });
499
500 if (Candidates.empty())
501 return false;
502
503 Decls.reserve(N: Candidates.size());
504 for (const Candidate &C : Candidates) {
505 Decl *LookupRes = C.first.get();
506 ASTImporter *Importer = C.second;
507 auto NDOrErr = Importer->Import(FromD: LookupRes);
508 NamedDecl *ND = cast<NamedDecl>(Val: llvm::cantFail(ValOrErr: std::move(NDOrErr)));
509 assert(ND);
510 // If we don't import specialization, they are not available via lookup
511 // because the lookup result is imported TemplateDecl and it does not
512 // reference its specializations until they are imported explicitly.
513 bool IsSpecImportFailed =
514 importSpecializationsIfNeeded(D: LookupRes, Importer);
515 assert(!IsSpecImportFailed);
516 (void)IsSpecImportFailed;
517 Decls.push_back(Elt: ND);
518 }
519 SetExternalVisibleDeclsForName(DC, Name, Decls);
520 return true;
521}
522
523void ExternalASTMerger::FindExternalLexicalDecls(
524 const DeclContext *DC, llvm::function_ref<bool(Decl::Kind)> IsKindWeWant,
525 SmallVectorImpl<Decl *> &Result) {
526 ForEachMatchingDC(DC, Callback: [&](ASTImporter &Forward, ASTImporter &Reverse,
527 Source<const DeclContext *> SourceDC) -> bool {
528 for (const Decl *SourceDecl : SourceDC.get()->decls()) {
529 if (IsKindWeWant(SourceDecl->getKind())) {
530 auto ImportedDeclOrErr = Forward.Import(FromD: SourceDecl);
531 if (ImportedDeclOrErr)
532 assert(!(*ImportedDeclOrErr) ||
533 IsSameDC((*ImportedDeclOrErr)->getDeclContext(), DC));
534 else
535 llvm::consumeError(Err: ImportedDeclOrErr.takeError());
536 }
537 }
538 return false;
539 });
540}
541