diff --git a/Makefile.rules b/Makefile.rules
index cb4abafd289..d05970c18ab 100644
--- a/Makefile.rules
+++ b/Makefile.rules
@@ -1713,8 +1713,14 @@ $(ObjDir)/%GenDFAPacketizer.inc.tmp : %.td $(ObjDir)/.dir $(LLVM_TBLGEN)
 	$(Echo) "Building $(<F) DFA packetizer tables with tblgen"
 	$(Verb) $(LLVMTableGen) -gen-dfa-packetizer -o $(call SYSPATH, $@) $<
 
+# Dump all the records to <target>.td.expanded.  This is useful for debugging.
+$(TARGET:%=%.td.expanded): \
+%.td.expanded : %.td $(LLVM_TBLGEN)
+	$(Echo) "Building a fully expanded version of $(<F)"
+	$(Verb) $(LLVMTableGen) -o $(call SYSPATH, $@) $<
+
 clean-local::
-	-$(Verb) $(RM) -f $(INCFiles)
+	-$(Verb) $(RM) -f $(INCFiles) $(TARGET).td.expanded
 
 endif # TARGET