Index: cmake/modules/TableGen.cmake
===================================================================
--- cmake/modules/TableGen.cmake
+++ cmake/modules/TableGen.cmake
@@ -28,7 +28,8 @@
     COMMAND ${${project}_TABLEGEN_EXE} ${ARGN} -I ${CMAKE_CURRENT_SOURCE_DIR}
     -I ${LLVM_MAIN_SRC_DIR}/lib/Target -I ${LLVM_MAIN_INCLUDE_DIR}
     ${LLVM_TARGET_DEFINITIONS_ABSOLUTE}
-    -o ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.tmp
+    -o ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.tmp ||
+    { rm -f ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.tmp && false \; }
     # The file in LLVM_TARGET_DEFINITIONS may be not in the current
     # directory and local_tds may not contain it, so we must
     # explicitly list it here: