2 files changed, 76 insertions, 2 deletions

diff --git a/clang/lib/AST/ODRHash.cpp b/clang/lib/AST/ODRHash.cpp
index 35af0e98a91..b75de54e07f 100644
--- a/clang/lib/AST/ODRHash.cpp
+++ b/clang/lib/AST/ODRHash.cpp
@@ -102,6 +102,10 @@ public:
     }
   }
 
+  void AddQualType(QualType T) {
+    Hash.AddQualType(T);
+  }
+
   void Visit(const Decl *D) {
     ID.AddInteger(D->getKind());
     Inherited::Visit(D);
@@ -112,6 +116,11 @@ public:
     Inherited::VisitNamedDecl(D);
   }
 
+  void VisitValueDecl(const ValueDecl *D) {
+    AddQualType(D->getType());
+    Inherited::VisitValueDecl(D);
+  }
+
   void VisitAccessSpecDecl(const AccessSpecDecl *D) {
     ID.AddInteger(D->getAccess());
     Inherited::VisitAccessSpecDecl(D);
@@ -185,8 +194,59 @@ void ODRHash::AddDecl(const Decl *D) {
   ID.AddInteger(D->getKind());
 }
 
-void ODRHash::AddType(const Type *T) {}
-void ODRHash::AddQualType(QualType T) {}
+// Process a Type pointer.  Add* methods call back into ODRHash while Visit*
+// methods process the relevant parts of the Type.
+class ODRTypeVisitor : public TypeVisitor<ODRTypeVisitor> {
+  typedef TypeVisitor<ODRTypeVisitor> Inherited;
+  llvm::FoldingSetNodeID &ID;
+  ODRHash &Hash;
+
+public:
+  ODRTypeVisitor(llvm::FoldingSetNodeID &ID, ODRHash &Hash)
+      : ID(ID), Hash(Hash) {}
+
+  void AddStmt(Stmt *S) {
+    Hash.AddBoolean(S);
+    if (S) {
+      Hash.AddStmt(S);
+    }
+  }
+
+  void Visit(const Type *T) {
+    ID.AddInteger(T->getTypeClass());
+    Inherited::Visit(T);
+  }
+
+  void VisitType(const Type *T) {}
+
+  void VisitBuiltinType(const BuiltinType *T) {
+    ID.AddInteger(T->getKind());
+    VisitType(T);
+  }
+};
+
+void ODRHash::AddType(const Type *T) {
+  assert(T && "Expecting non-null pointer.");
+  auto Result = TypeMap.insert(std::make_pair(T, TypeMap.size()));
+  ID.AddInteger(Result.first->second);
+  // On first encounter of a Type pointer, process it.  Every time afterwards,
+  // only the index value is needed.
+  if (!Result.second) {
+    return;
+  }
+
+  ODRTypeVisitor(ID, *this).Visit(T);
+}
+
+void ODRHash::AddQualType(QualType T) {
+  AddBoolean(T.isNull());
+  if (T.isNull())
+    return;
+  SplitQualType split = T.split();
+  ID.AddInteger(split.Quals.getAsOpaqueValue());
+  AddType(split.Ty);
+}
+
 void ODRHash::AddBoolean(bool Value) {
   Bools.push_back(Value);
 }
diff --git a/clang/test/Modules/odr_hash.cpp b/clang/test/Modules/odr_hash.cpp
index 2b2a788efc7..7b696346be3 100644
--- a/clang/test/Modules/odr_hash.cpp
+++ b/clang/test/Modules/odr_hash.cpp
@@ -148,6 +148,20 @@ S2 s2;
 // expected-error@second.h:* {{'Field::S2' has different definitions in different modules; first difference is definition in module 'SecondModule' found field 'y'}}
 // expected-note@first.h:* {{but in 'FirstModule' found field 'x'}}
 #endif
+
+#if defined(FIRST)
+struct S3 {
+  double x;
+};
+#elif defined(SECOND)
+struct S3 {
+  int x;
+};
+#else
+S3 s3;
+// expected-error@first.h:* {{'Field::S3::x' from module 'FirstModule' is not present in definition of 'Field::S3' in module 'SecondModule'}}
+// expected-note@second.h:* {{declaration of 'x' does not match}}
+#endif
 }  // namespace Field
 
 // Naive parsing of AST can lead to cycles in processing.  Ensure