diff --git a/llvm/include/llvm/CodeGen/AsmPrinter.h b/llvm/include/llvm/CodeGen/AsmPrinter.h
--- a/llvm/include/llvm/CodeGen/AsmPrinter.h
+++ b/llvm/include/llvm/CodeGen/AsmPrinter.h
@@ -639,9 +639,6 @@
   /// Emit 32- or 64-bit value depending on the DWARF format.
   void emitDwarfLengthOrOffset(uint64_t Value) const;
 
-  /// Emit a special value of 0xffffffff if producing 64-bit debugging info.
-  void maybeEmitDwarf64Mark() const;
-
   /// Emit a unit length field. The actual format, DWARF32 or DWARF64, is chosen
   /// according to the settings.
   void emitDwarfUnitLength(uint64_t Length, const Twine &Comment) const;
diff --git a/llvm/include/llvm/MC/MCStreamer.h b/llvm/include/llvm/MC/MCStreamer.h
--- a/llvm/include/llvm/MC/MCStreamer.h
+++ b/llvm/include/llvm/MC/MCStreamer.h
@@ -1079,6 +1079,18 @@
   void Finish(SMLoc EndLoc = SMLoc());
 
   virtual bool mayHaveInstructions(MCSection &Sec) const { return true; }
+
+  /// Emit a special value of 0xffffffff if producing 64-bit debugging info.
+  void maybeEmitDwarf64Mark();
+
+  /// Emit a unit length field. The actual format, DWARF32 or DWARF64, is chosen
+  /// according to the settings.
+  virtual void emitDwarfUnitLength(uint64_t Length, const Twine &Comment);
+
+  /// Emit a unit length field. The actual format, DWARF32 or DWARF64, is chosen
+  /// according to the settings.
+  virtual void emitDwarfUnitLength(const MCSymbol *Hi, const MCSymbol *Lo,
+                                   const Twine &Comment);
 };
 
 /// Create a dummy machine code streamer, which does nothing. This is useful for
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
@@ -198,26 +198,14 @@
   OutStreamer->emitIntValue(Value, getDwarfOffsetByteSize());
 }
 
-void AsmPrinter::maybeEmitDwarf64Mark() const {
-  if (!isDwarf64())
-    return;
-  OutStreamer->AddComment("DWARF64 Mark");
-  OutStreamer->emitInt32(dwarf::DW_LENGTH_DWARF64);
-}
-
 void AsmPrinter::emitDwarfUnitLength(uint64_t Length,
                                      const Twine &Comment) const {
-  assert(isDwarf64() || Length <= dwarf::DW_LENGTH_lo_reserved);
-  maybeEmitDwarf64Mark();
-  OutStreamer->AddComment(Comment);
-  OutStreamer->emitIntValue(Length, getDwarfOffsetByteSize());
+  OutStreamer->emitDwarfUnitLength(Length, Comment);
 }
 
 void AsmPrinter::emitDwarfUnitLength(const MCSymbol *Hi, const MCSymbol *Lo,
                                      const Twine &Comment) const {
-  maybeEmitDwarf64Mark();
-  OutStreamer->AddComment(Comment);
-  OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, getDwarfOffsetByteSize());
+  OutStreamer->emitDwarfUnitLength(Hi, Lo, Comment);
 }
 
 void AsmPrinter::emitCallSiteOffset(const MCSymbol *Hi, const MCSymbol *Lo,
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -991,6 +991,29 @@
   finishImpl();
 }
 
+void MCStreamer::maybeEmitDwarf64Mark() {
+  if (Context.getDwarfFormat() != dwarf::DWARF64)
+    return;
+  AddComment("DWARF64 Mark");
+  emitInt32(dwarf::DW_LENGTH_DWARF64);
+}
+
+void MCStreamer::emitDwarfUnitLength(uint64_t Length, const Twine &Comment) {
+  assert(Context.getDwarfFormat() == dwarf::DWARF64 ||
+         Length <= dwarf::DW_LENGTH_lo_reserved);
+  maybeEmitDwarf64Mark();
+  AddComment(Comment);
+  emitIntValue(Length, dwarf::getDwarfOffsetByteSize(Context.getDwarfFormat()));
+}
+
+void MCStreamer::emitDwarfUnitLength(const MCSymbol *Hi, const MCSymbol *Lo,
+                                     const Twine &Comment) {
+  maybeEmitDwarf64Mark();
+  AddComment(Comment);
+  emitAbsoluteSymbolDiff(
+      Hi, Lo, dwarf::getDwarfOffsetByteSize(Context.getDwarfFormat()));
+}
+
 void MCStreamer::emitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
   visitUsedExpr(*Value);
   Symbol->setVariableValue(Value);
diff --git a/llvm/unittests/CodeGen/AsmPrinterDwarfTest.cpp b/llvm/unittests/CodeGen/AsmPrinterDwarfTest.cpp
--- a/llvm/unittests/CodeGen/AsmPrinterDwarfTest.cpp
+++ b/llvm/unittests/CodeGen/AsmPrinterDwarfTest.cpp
@@ -294,24 +294,6 @@
   EXPECT_EQ(TestPrinter->getAP()->getUnitLengthFieldByteSize(), 12u);
 }
 
-class AsmPrinterMaybeEmitDwarf64MarkTest : public AsmPrinterFixtureBase {};
-
-TEST_F(AsmPrinterMaybeEmitDwarf64MarkTest, DWARF32) {
-  if (!init("x86_64-pc-linux", /*DwarfVersion=*/4, dwarf::DWARF32))
-    return;
-
-  EXPECT_CALL(TestPrinter->getMS(), emitIntValue(_, _)).Times(0);
-  TestPrinter->getAP()->maybeEmitDwarf64Mark();
-}
-
-TEST_F(AsmPrinterMaybeEmitDwarf64MarkTest, DWARF64) {
-  if (!init("x86_64-pc-linux", /*DwarfVersion=*/4, dwarf::DWARF64))
-    return;
-
-  EXPECT_CALL(TestPrinter->getMS(), emitIntValue(dwarf::DW_LENGTH_DWARF64, 4));
-  TestPrinter->getAP()->maybeEmitDwarf64Mark();
-}
-
 class AsmPrinterEmitDwarfUnitLengthAsIntTest : public AsmPrinterFixtureBase {
 protected:
   uint64_t Val = 42;