Index: include/llvm/DebugInfo/CodeView/TypeRecord.h
===================================================================
--- include/llvm/DebugInfo/CodeView/TypeRecord.h
+++ include/llvm/DebugInfo/CodeView/TypeRecord.h
@@ -946,6 +946,44 @@
   uint32_t LineNumber;
 };
 
+// LF_UDT_MOD_SRC_LINE
+class UdtModSourceLineRecord : public TypeRecord {
+public:
+  UdtModSourceLineRecord(TypeIndex UDT, TypeIndex SourceFile,
+                         uint32_t LineNumber, uint16_t Module)
+      : TypeRecord(TypeRecordKind::UdtSourceLine), UDT(UDT),
+        SourceFile(SourceFile), LineNumber(LineNumber), Module(Module) {}
+
+  bool remapTypeIndices(ArrayRef<TypeIndex> IndexMap);
+
+  static ErrorOr<UdtModSourceLineRecord> deserialize(TypeRecordKind Kind,
+                                                     ArrayRef<uint8_t> &Data) {
+    const Layout *L = nullptr;
+    CV_DESERIALIZE(Data, L);
+
+    return UdtModSourceLineRecord(L->UDT, L->SourceFile, L->LineNumber,
+                                  L->Module);
+  }
+
+  TypeIndex getUDT() const { return UDT; }
+  TypeIndex getSourceFile() const { return SourceFile; }
+  uint32_t getLineNumber() const { return LineNumber; }
+  uint16_t getModule() const { return Module; }
+
+private:
+  struct Layout {
+    TypeIndex UDT;        // The user-defined type
+    TypeIndex SourceFile; // StringID containing the source filename
+    ulittle32_t LineNumber;
+    ulittle16_t Module; // Module that contributes this UDT definition
+  };
+
+  TypeIndex UDT;
+  TypeIndex SourceFile;
+  uint32_t LineNumber;
+  uint16_t Module;
+};
+
 // LF_BUILDINFO
 class BuildInfoRecord : public TypeRecord {
 public:
Index: include/llvm/DebugInfo/CodeView/TypeRecords.def
===================================================================
--- include/llvm/DebugInfo/CodeView/TypeRecords.def
+++ include/llvm/DebugInfo/CodeView/TypeRecords.def
@@ -81,6 +81,7 @@
 TYPE_RECORD_ALIAS(LF_SUBSTR_LIST, 0x1604, StringList, ArgList)
 TYPE_RECORD(LF_STRING_ID, 0x1605, StringId)
 TYPE_RECORD(LF_UDT_SRC_LINE, 0x1606, UdtSourceLine)
+TYPE_RECORD(LF_UDT_MOD_SRC_LINE, 0x1607, UdtModSourceLine)
 
 TYPE_RECORD(LF_METHODLIST, 0x1206, MethodOverloadList)
 
@@ -194,10 +195,6 @@
 CV_TYPE(LF_VECTOR, 0x151b)
 CV_TYPE(LF_MATRIX, 0x151c)
 
-// ID leaf records. Subsequent leaf types may be referenced from .debug$S.
-
-CV_TYPE(LF_UDT_MOD_SRC_LINE, 0x1607)
-
 // Numeric leaf types. These are generally contained in other records, and not
 // encountered in the main type stream.
 
Index: include/llvm/DebugInfo/CodeView/TypeTableBuilder.h
===================================================================
--- include/llvm/DebugInfo/CodeView/TypeTableBuilder.h
+++ include/llvm/DebugInfo/CodeView/TypeTableBuilder.h
@@ -51,6 +51,7 @@
   TypeIndex writeStringId(const StringIdRecord &Record);
   TypeIndex writeVFTable(const VFTableRecord &Record);
   TypeIndex writeUdtSourceLine(const UdtSourceLineRecord &Record);
+  TypeIndex writeUdtModSourceLine(const UdtModSourceLineRecord &Record);
   TypeIndex writeFuncId(const FuncIdRecord &Record);
   TypeIndex writeMemberFuncId(const MemberFuncIdRecord &Record);
   TypeIndex writeBuildInfo(const BuildInfoRecord &Record);
Index: lib/DebugInfo/CodeView/TypeDumper.cpp
===================================================================
--- lib/DebugInfo/CodeView/TypeDumper.cpp
+++ lib/DebugInfo/CodeView/TypeDumper.cpp
@@ -514,6 +514,14 @@
   W.printNumber("LineNumber", Line.getLineNumber());
 }
 
+void CVTypeDumperImpl::visitUdtModSourceLine(TypeLeafKind Leaf,
+                                             UdtModSourceLineRecord &Line) {
+  printTypeIndex("UDT", Line.getUDT());
+  printTypeIndex("SourceFile", Line.getSourceFile());
+  W.printNumber("LineNumber", Line.getLineNumber());
+  W.printNumber("Module", Line.getModule());
+}
+
 void CVTypeDumperImpl::visitBuildInfo(TypeLeafKind Leaf,
                                       BuildInfoRecord &Args) {
   W.printNumber("NumArgs", static_cast<uint32_t>(Args.getArgs().size()));
Index: lib/DebugInfo/CodeView/TypeTableBuilder.cpp
===================================================================
--- lib/DebugInfo/CodeView/TypeTableBuilder.cpp
+++ lib/DebugInfo/CodeView/TypeTableBuilder.cpp
@@ -226,6 +226,16 @@
 }
 
 TypeIndex
+TypeTableBuilder::writeUdtModSourceLine(const UdtModSourceLineRecord &Record) {
+  TypeRecordBuilder Builder(Record.getKind());
+  Builder.writeTypeIndex(Record.getUDT());
+  Builder.writeTypeIndex(Record.getSourceFile());
+  Builder.writeUInt32(Record.getLineNumber());
+  Builder.writeUInt16(Record.getModule());
+  return writeRecord(Builder);
+}
+
+TypeIndex
 TypeTableBuilder::writeFuncId(const FuncIdRecord &Record) {
   TypeRecordBuilder Builder(Record.getKind());
   Builder.writeTypeIndex(Record.getParentScope());