Serialize the IDNS for a UsingShadowDecl rather than recomputing it.

Attempting to recompute it are doomed to fail because the IDNS of a declaration
is not necessarily preserved across serialization and deserialization (in turn
because whether a friend declaration is visible depends on whether some prior
non-friend declaration exists).

llvm-svn: 321921

3 files changed, 5 insertions, 3 deletions

diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index 41f2449a9d6..afbc3f315f5 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -2387,10 +2387,10 @@ UsingShadowDecl::UsingShadowDecl(Kind K, ASTContext &C, DeclContext *DC,
                                  SourceLocation Loc, UsingDecl *Using,
                                  NamedDecl *Target)
     : NamedDecl(K, DC, Loc, Using ? Using->getDeclName() : DeclarationName()),
-      redeclarable_base(C), Underlying(Target),
+      redeclarable_base(C), Underlying(),
       UsingOrNextShadow(cast<NamedDecl>(Using)) {
   if (Target)
-    IdentifierNamespace = Target->getIdentifierNamespace();
+    setTargetDecl(Target);
   setImplicit();
 }
 
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index efbaf92a849..0cf9afb0759 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -1500,7 +1500,8 @@ void ASTDeclReader::VisitUsingPackDecl(UsingPackDecl *D) {
 void ASTDeclReader::VisitUsingShadowDecl(UsingShadowDecl *D) {
   RedeclarableResult Redecl = VisitRedeclarable(D);
   VisitNamedDecl(D);
-  D->setTargetDecl(ReadDeclAs<NamedDecl>());
+  D->Underlying = ReadDeclAs<NamedDecl>();
+  D->IdentifierNamespace = Record.readInt();
   D->UsingOrNextShadow = ReadDeclAs<NamedDecl>();
   UsingShadowDecl *Pattern = ReadDeclAs<UsingShadowDecl>();
   if (Pattern)
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index bb72a3b383e..341f0e16075 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -1192,6 +1192,7 @@ void ASTDeclWriter::VisitUsingShadowDecl(UsingShadowDecl *D) {
   VisitRedeclarable(D);
   VisitNamedDecl(D);
   Record.AddDeclRef(D->getTargetDecl());
+  Record.push_back(D->getIdentifierNamespace());
   Record.AddDeclRef(D->UsingOrNextShadow);
   Record.AddDeclRef(Context.getInstantiatedFromUsingShadowDecl(D));
   Code = serialization::DECL_USING_SHADOW;