Index: llvm/tools/clang/lib/CodeGen/CGDebugInfo.h
===================================================================
--- llvm/tools/clang/lib/CodeGen/CGDebugInfo.h
+++ llvm/tools/clang/lib/CodeGen/CGDebugInfo.h
@@ -283,6 +283,9 @@
   /// \brief - Emit C++ using directive.
   void EmitUsingDirective(const UsingDirectiveDecl &UD);
 
+  /// EmitExplicitCastType - Emit the type explicitly casted to.
+  void EmitExplicitCastType(QualType Ty);
+
   /// \brief - Emit C++ using declaration.
   void EmitUsingDecl(const UsingDecl &UD);
 
Index: llvm/tools/clang/lib/CodeGen/CGDebugInfo.cpp
===================================================================
--- llvm/tools/clang/lib/CodeGen/CGDebugInfo.cpp
+++ llvm/tools/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -3347,3 +3347,11 @@
 
   DBuilder.finalize();
 }
+
+void CGDebugInfo::EmitExplicitCastType(QualType Ty) {
+  if (CGM.getCodeGenOpts().getDebugInfo() < CodeGenOptions::LimitedDebugInfo)
+    return;
+  llvm::DIType DieTy = getOrCreateType(Ty, getOrCreateMainFile());
+  // Don't ignore in case of explicit cast where it is referenced indirectly.
+  DBuilder.retainType(DieTy);
+}
Index: llvm/tools/clang/lib/CodeGen/CGExprScalar.cpp
===================================================================
--- llvm/tools/clang/lib/CodeGen/CGExprScalar.cpp
+++ llvm/tools/clang/lib/CodeGen/CGExprScalar.cpp
@@ -274,6 +274,10 @@
   Value *VisitExplicitCastExpr(ExplicitCastExpr *E) {
     if (E->getType()->isVariablyModifiedType())
       CGF.EmitVariablyModifiedType(E->getType());
+
+    if (CGDebugInfo *DI = CGF.getDebugInfo())
+      DI->EmitExplicitCastType(E->getType());
+
     return VisitCastExpr(E);
   }
   Value *VisitCastExpr(CastExpr *E);
Index: llvm/tools/clang/test/CodeGen/Debug-info-explicitcast.c
===================================================================
--- llvm/tools/clang/test/CodeGen/Debug-info-explicitcast.c
+++ llvm/tools/clang/test/CodeGen/Debug-info-explicitcast.c
@@ -0,0 +1,24 @@
+// RUN: %clang_cc1 -emit-llvm -g %s -o - | FileCheck %s
+
+struct S2 {
+  int i;
+};
+void foo2(void *p) { ((struct S2 *)p)->i++; }
+
+
+
+struct S3 {
+  int i;
+};
+void foo3(struct S3 *p) { p->i++; }
+
+union U4 {
+  int i;
+  char c;
+};
+void foo4(void *p) { ((union U4 *)p)->i++; }
+
+// CHECK: DW_TAG_structure_type ] [S2] 
+// CHECK: DW_TAG_union_type ] [U4]
+// CHECK: DW_TAG_structure_type ] [S3]
+