Eliminate a hang while loading a sequence of redeclarable entities. In
essence, the redeclaration chain for a class could end up in an
inconsistent state while deserializing multiple declarations in that
chain, where the circular linked list was not, in fact,
circular. Since only two redeclarations of the same entity will get
loaded when we're in this state, restore circularity when both have
been loaded. Fixes <rdar://problem/10324940> / PR11195.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@143037 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index a15dc42..f64aa20 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -278,8 +278,8 @@
}
void ASTDeclReader::VisitTagDecl(TagDecl *TD) {
- VisitTypeDecl(TD);
VisitRedeclarable(TD);
+ VisitTypeDecl(TD);
TD->IdentifierNamespace = Record[Idx++];
TD->setTagKind((TagDecl::TagKind)Record[Idx++]);
TD->setCompleteDefinition(Record[Idx++]);
@@ -340,8 +340,8 @@
}
void ASTDeclReader::VisitFunctionDecl(FunctionDecl *FD) {
- VisitDeclaratorDecl(FD);
VisitRedeclarable(FD);
+ VisitDeclaratorDecl(FD);
ReadDeclarationNameLoc(FD->DNLoc, FD->getDeclName(), Record, Idx);
FD->IdentifierNamespace = Record[Idx++];
@@ -712,8 +712,8 @@
}
void ASTDeclReader::VisitVarDecl(VarDecl *VD) {
- VisitDeclaratorDecl(VD);
VisitRedeclarable(VD);
+ VisitDeclaratorDecl(VD);
VD->VarDeclBits.SClass = (StorageClass)Record[Idx++];
VD->VarDeclBits.SClassAsWritten = (StorageClass)Record[Idx++];
VD->VarDeclBits.ThreadSpecified = Record[Idx++];
@@ -1329,18 +1329,37 @@
// We temporarily set the first (canonical) declaration as the previous one
// which is the one that matters and mark the real previous DeclID to be
// loaded & attached later on.
- D->RedeclLink = typename Redeclarable<T>::PreviousDeclLink(
- cast_or_null<T>(Reader.GetDecl(FirstDeclID)));
+ T *FirstDecl = cast_or_null<T>(Reader.GetDecl(FirstDeclID));
+ D->RedeclLink = typename Redeclarable<T>::PreviousDeclLink(FirstDecl);
if (PreviousDeclID != FirstDeclID)
Reader.PendingPreviousDecls.push_back(std::make_pair(static_cast<T*>(D),
PreviousDeclID));
+
+ // If the first declaration in the chain is in an inconsistent
+ // state where it thinks that it is the only declaration, fix its
+ // redeclaration link now to point at this declaration, so that we have a
+ // proper redeclaration chain.
+ if (FirstDecl->RedeclLink.getPointer() == FirstDecl) {
+ FirstDecl->RedeclLink
+ = typename Redeclarable<T>::LatestDeclLink(static_cast<T*>(D));
+ }
break;
}
- case PointsToLatest:
- D->RedeclLink = typename Redeclarable<T>::LatestDeclLink(
- ReadDeclAs<T>(Record, Idx));
+ case PointsToLatest: {
+ T *LatestDecl = ReadDeclAs<T>(Record, Idx);
+ D->RedeclLink = typename Redeclarable<T>::LatestDeclLink(LatestDecl);
+
+ // If the latest declaration in the chain is in an inconsistent
+ // state where it thinks that it is the only declaration, fix its
+ // redeclaration link now to point at this declaration, so that we have a
+ // proper redeclaration chain.
+ if (LatestDecl->RedeclLink.getPointer() == LatestDecl) {
+ LatestDecl->RedeclLink
+ = typename Redeclarable<T>::PreviousDeclLink(static_cast<T*>(D));
+ }
break;
}
+ }
assert(!(Kind == PointsToPrevious &&
Reader.FirstLatestDeclIDs.find(ThisDeclID) !=
diff --git a/lib/Serialization/ASTWriterDecl.cpp b/lib/Serialization/ASTWriterDecl.cpp
index 2925f49..f613867 100644
--- a/lib/Serialization/ASTWriterDecl.cpp
+++ b/lib/Serialization/ASTWriterDecl.cpp
@@ -198,8 +198,8 @@
}
void ASTDeclWriter::VisitTagDecl(TagDecl *D) {
- VisitTypeDecl(D);
VisitRedeclarable(D);
+ VisitTypeDecl(D);
Record.push_back(D->getIdentifierNamespace());
Record.push_back((unsigned)D->getTagKind()); // FIXME: stable encoding
Record.push_back(D->isCompleteDefinition());
@@ -289,8 +289,8 @@
}
void ASTDeclWriter::VisitFunctionDecl(FunctionDecl *D) {
- VisitDeclaratorDecl(D);
VisitRedeclarable(D);
+ VisitDeclaratorDecl(D);
Writer.AddDeclarationNameLoc(D->DNLoc, D->getDeclName(), Record);
Record.push_back(D->getIdentifierNamespace());
@@ -651,8 +651,8 @@
}
void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
- VisitDeclaratorDecl(D);
VisitRedeclarable(D);
+ VisitDeclaratorDecl(D);
Record.push_back(D->getStorageClass()); // FIXME: stable encoding
Record.push_back(D->getStorageClassAsWritten());
Record.push_back(D->isThreadSpecified());
@@ -1336,6 +1336,8 @@
// Abbreviation for DECL_ENUM
Abv = new BitCodeAbbrev();
Abv->Add(BitCodeAbbrevOp(serialization::DECL_ENUM));
+ // Redeclarable
+ Abv->Add(BitCodeAbbrevOp(0)); // No redeclaration
// Decl
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
@@ -1353,8 +1355,6 @@
// TypeDecl
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
- // Redeclarable
- Abv->Add(BitCodeAbbrevOp(0)); // No redeclaration
// TagDecl
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // IdentifierNamespace
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getTagKind
@@ -1382,6 +1382,8 @@
// Abbreviation for DECL_RECORD
Abv = new BitCodeAbbrev();
Abv->Add(BitCodeAbbrevOp(serialization::DECL_RECORD));
+ // Redeclarable
+ Abv->Add(BitCodeAbbrevOp(0)); // No redeclaration
// Decl
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
@@ -1399,8 +1401,6 @@
// TypeDecl
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
- // Redeclarable
- Abv->Add(BitCodeAbbrevOp(0)); // No redeclaration
// TagDecl
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // IdentifierNamespace
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getTagKind
@@ -1422,6 +1422,8 @@
// Abbreviation for DECL_PARM_VAR
Abv = new BitCodeAbbrev();
Abv->Add(BitCodeAbbrevOp(serialization::DECL_PARM_VAR));
+ // Redeclarable
+ Abv->Add(BitCodeAbbrevOp(0)); // No redeclaration
// Decl
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
@@ -1442,7 +1444,6 @@
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
Abv->Add(BitCodeAbbrevOp(0)); // hasExtInfo
// VarDecl
- Abv->Add(BitCodeAbbrevOp(0)); // No redeclaration
Abv->Add(BitCodeAbbrevOp(0)); // StorageClass
Abv->Add(BitCodeAbbrevOp(0)); // StorageClassAsWritten
Abv->Add(BitCodeAbbrevOp(0)); // isThreadSpecified
@@ -1495,6 +1496,8 @@
// Abbreviation for DECL_VAR
Abv = new BitCodeAbbrev();
Abv->Add(BitCodeAbbrevOp(serialization::DECL_VAR));
+ // Redeclarable
+ Abv->Add(BitCodeAbbrevOp(0)); // No redeclaration
// Decl
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
@@ -1515,7 +1518,6 @@
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
Abv->Add(BitCodeAbbrevOp(0)); // hasExtInfo
// VarDecl
- Abv->Add(BitCodeAbbrevOp(0)); // No redeclaration
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // StorageClass
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // StorageClassAsWritten
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isThreadSpecified