1 files changed, 19 insertions, 10 deletions

diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index b0b362f4cdb..2cc0d071a96 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -1665,14 +1665,19 @@ void Sema::ActOnBaseSpecifiers(Decl *ClassDecl, CXXBaseSpecifier **Bases,
 
 /// \brief Determine whether the type \p Derived is a C++ class that is
 /// derived from the type \p Base.
-bool Sema::IsDerivedFrom(QualType Derived, QualType Base) {
+bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base) {
   if (!getLangOpts().CPlusPlus)
     return false;
-  
+
   CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
   if (!DerivedRD)
     return false;
   
+  // FIXME: In a modules build, do we need the entire path to be visible for us
+  // to be able to use the inheritance relationship?
+  if (RequireCompleteType(Loc, Derived, 0) && !DerivedRD->isBeingDefined())
+    return false;
+  
   CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
   if (!BaseRD)
     return false;
@@ -1682,13 +1687,13 @@ bool Sema::IsDerivedFrom(QualType Derived, QualType Base) {
   if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
     return false;
 
-  // FIXME: instantiate DerivedRD if necessary.  We need a PoI for this.
-  return DerivedRD->hasDefinition() && DerivedRD->isDerivedFrom(BaseRD);
+  return DerivedRD->isDerivedFrom(BaseRD);
 }
 
 /// \brief Determine whether the type \p Derived is a C++ class that is
 /// derived from the type \p Base.
-bool Sema::IsDerivedFrom(QualType Derived, QualType Base, CXXBasePaths &Paths) {
+bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base,
+                         CXXBasePaths &Paths) {
   if (!getLangOpts().CPlusPlus)
     return false;
   
@@ -1696,6 +1701,9 @@ bool Sema::IsDerivedFrom(QualType Derived, QualType Base, CXXBasePaths &Paths) {
   if (!DerivedRD)
     return false;
   
+  if (RequireCompleteType(Loc, Derived, 0) && !DerivedRD->isBeingDefined())
+    return false;
+  
   CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
   if (!BaseRD)
     return false;
@@ -1747,7 +1755,7 @@ Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
   // explore multiple paths to determine if there is an ambiguity.
   CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
                      /*DetectVirtual=*/false);
-  bool DerivationOkay = IsDerivedFrom(Derived, Base, Paths);
+  bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
   assert(DerivationOkay &&
          "Can only be used with a derived-to-base conversion");
   (void)DerivationOkay;
@@ -1781,7 +1789,7 @@ Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
     // performance isn't as much of an issue.
     Paths.clear();
     Paths.setRecordingPaths(true);
-    bool StillOkay = IsDerivedFrom(Derived, Base, Paths);
+    bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
     assert(StillOkay && "Can only be used with a derived-to-base conversion");
     (void)StillOkay;
 
@@ -2757,7 +2765,8 @@ static bool FindBaseInitializer(Sema &SemaRef,
     // virtual base class.
     CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
                        /*DetectVirtual=*/false);
-    if (SemaRef.IsDerivedFrom(SemaRef.Context.getTypeDeclType(ClassDecl), 
+    if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(),
+                              SemaRef.Context.getTypeDeclType(ClassDecl),
                               BaseType, Paths)) {
       for (CXXBasePaths::paths_iterator Path = Paths.begin();
            Path != Paths.end(); ++Path) {
@@ -7123,7 +7132,7 @@ Decl *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) {
     if (ConvType == ClassType)
       Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used)
         << ClassType;
-    else if (IsDerivedFrom(ClassType, ConvType))
+    else if (IsDerivedFrom(Conversion->getLocation(), ClassType, ConvType))
       Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used)
         <<  ClassType << ConvType;
   } else if (ConvType->isVoidType()) {
@@ -13021,7 +13030,7 @@ bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
 
   if (!Context.hasSameUnqualifiedType(NewClassTy, OldClassTy)) {
     // Check if the new class derives from the old class.
-    if (!IsDerivedFrom(NewClassTy, OldClassTy)) {
+    if (!IsDerivedFrom(New->getLocation(), NewClassTy, OldClassTy)) {
       Diag(New->getLocation(), diag::err_covariant_return_not_derived)
           << New->getDeclName() << NewTy << OldTy
           << New->getReturnTypeSourceRange();