Index: include/llvm/IR/DIBuilder.h
===================================================================
--- include/llvm/IR/DIBuilder.h
+++ include/llvm/IR/DIBuilder.h
@@ -757,12 +757,12 @@
                                          const DILocation *DL,
                                          Instruction *InsertBefore);
 
-    /// Replace the vtable holder in the given composite type.
+    /// Replace the vtable holder in the given type.
     ///
     /// If this creates a self reference, it may orphan some unresolved cycles
     /// in the operands of \c T, so \a DIBuilder needs to track that.
     void replaceVTableHolder(DICompositeType *&T,
-                             DICompositeType *VTableHolder);
+                             DIType *VTableHolder);
 
     /// Replace arrays on a composite type.
     ///
Index: lib/CodeGen/AsmPrinter/DwarfUnit.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -960,8 +960,9 @@
 
     // This is outside the DWARF spec, but GDB expects a DW_AT_containing_type
     // inside C++ composite types to point to the base class with the vtable.
-    if (auto *ContainingType =
-            dyn_cast_or_null<DICompositeType>(resolve(CTy->getVTableHolder())))
+    // Rust uses DW_AT_containing_type to link a vtable to the type
+    // for which it was created.
+    if (auto *ContainingType = resolve(CTy->getVTableHolder()))
       addDIEEntry(Buffer, dwarf::DW_AT_containing_type,
                   *getOrCreateTypeDIE(ContainingType));
 
Index: lib/IR/DIBuilder.cpp
===================================================================
--- lib/IR/DIBuilder.cpp
+++ lib/IR/DIBuilder.cpp
@@ -874,7 +874,7 @@
 }
 
 void DIBuilder::replaceVTableHolder(DICompositeType *&T,
-                                    DICompositeType *VTableHolder) {
+                                    DIType *VTableHolder) {
   {
     TypedTrackingMDRef<DICompositeType> N(T);
     N->replaceVTableHolder(VTableHolder);
Index: test/DebugInfo/Generic/containing-type-extension.ll
===================================================================
--- /dev/null
+++ test/DebugInfo/Generic/containing-type-extension.ll
@@ -0,0 +1,39 @@
+; REQUIRES: object-emission
+
+; RUN: %llc_dwarf -O0 -filetype=obj < %s > %t
+; RUN: llvm-dwarfdump -v -debug-info %t | FileCheck %s
+
+; Make sure we correctly handle context of a subprogram being a type identifier.
+; CHECK: [[SP:.*]]: DW_TAG_structure_type
+; CHECK-NOT: TAG
+; CHECK: DW_AT_containing_type [DW_FORM_ref4]
+; CHECK: DW_AT_name [DW_FORM_strp] {{.*}}= "vtable")
+
+; The code doesn't actually matter.
+define i32 @main() #0 !dbg !4 {
+entry:
+  %retval = alloca i32, align 4
+  store i32 0, i32* %retval
+  ret i32 0, !dbg !10
+}
+
+attributes #0 = { nounwind uwtable }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!9, !11}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_Rust, producer: "clang version 3.4 (trunk 185475)", isOptimized: false, emissionKind: FullDebug, file: !1, enums: !2, retainedTypes: !2, globals: !15, imports: !2)
+!1 = !DIFile(filename: "CodeGen/dwarf-version.c", directory: "test")
+!2 = !{}
+!4 = distinct !DISubprogram(name: "main", line: 6, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped | DIFlagMainSubprogram, isOptimized: false, unit: !0, scopeLine: 6, file: !1, scope: !5, type: !6, variables: !2)
+!5 = !DIFile(filename: "CodeGen/dwarf-version.c", directory: "test")
+!6 = !DISubroutineType(types: !7)
+!7 = !{!8}
+!8 = !DIBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!9 = !{i32 2, !"Dwarf Version", i32 4}
+!10 = !DILocation(line: 7, scope: !4)
+!11 = !{i32 1, !"Debug Info Version", i32 3}
+!12 = !DICompositeType(tag: DW_TAG_structure_type, name: "vtable", size: 8, align: 8, elements: !2, identifier: "vtable", vtableHolder: !8)
+!13 = !DIGlobalVariableExpression(var: !14, expr: !DIExpression())
+!14 = !DIGlobalVariable(name: "vtable", linkageName: "vtable", scope: null, file: !1, line: 1, type: !12, isLocal: true, isDefinition: true)
+!15 = !{!13}
Index: unittests/IR/MetadataTest.cpp
===================================================================
--- unittests/IR/MetadataTest.cpp
+++ unittests/IR/MetadataTest.cpp
@@ -1314,6 +1314,11 @@
   EXPECT_EQ(nullptr, N->getVTableHolder());
   N->replaceVTableHolder(VTableHolder);
   EXPECT_EQ(VTableHolder, N->getVTableHolder());
+  // As an extension, the containing type can be anything.  This is
+  // used by Rust to associate vtables with their concrete type.
+  DIType *BasicType = getBasicType("basic");
+  N->replaceVTableHolder(BasicType);
+  EXPECT_EQ(BasicType, N->getVTableHolder());
   N->replaceVTableHolder(nullptr);
   EXPECT_EQ(nullptr, N->getVTableHolder());