Ninja: don't set cmcldeps vars to empty string when they are not defined

Modules/CMakeCCompiler.cmake.in

@@ -49,7 +49,5 @@ SET(CMAKE_C_HAS_ISYSROOT "@CMAKE_C_HAS_ISYSROOT@")
 SET(CMAKE_C_IMPLICIT_LINK_LIBRARIES "@CMAKE_C_IMPLICIT_LINK_LIBRARIES@")
 SET(CMAKE_C_IMPLICIT_LINK_DIRECTORIES "@CMAKE_C_IMPLICIT_LINK_DIRECTORIES@")
 
-IF(MSVC_CXX_ARCHITECTURE_ID)
-  SET(CMAKE_CMCLDEPS_EXECUTABLE "@CMAKE_CMCLDEPS_EXECUTABLE@")
-  SET(CMAKE_CL_SHOWINCLUDE_PREFIX "@CMAKE_CL_SHOWINCLUDE_PREFIX@")
-ENDIF()
+@SET_CMAKE_CMCLDEPS_EXECUTABLE@
+@SET_CMAKE_CL_SHOWINCLUDE_PREFIX@

Modules/CMakeCXXCompiler.cmake.in

@@ -50,7 +50,5 @@ SET(CMAKE_CXX_HAS_ISYSROOT "@CMAKE_CXX_HAS_ISYSROOT@")
 SET(CMAKE_CXX_IMPLICIT_LINK_LIBRARIES "@CMAKE_CXX_IMPLICIT_LINK_LIBRARIES@")
 SET(CMAKE_CXX_IMPLICIT_LINK_DIRECTORIES "@CMAKE_CXX_IMPLICIT_LINK_DIRECTORIES@")
 
-IF(MSVC_CXX_ARCHITECTURE_ID)
-  SET(CMAKE_CMCLDEPS_EXECUTABLE "@CMAKE_CMCLDEPS_EXECUTABLE@")
-  SET(CMAKE_CL_SHOWINCLUDE_PREFIX "@CMAKE_CL_SHOWINCLUDE_PREFIX@")
-ENDIF()
+@SET_CMAKE_CMCLDEPS_EXECUTABLE@
+@SET_CMAKE_CL_SHOWINCLUDE_PREFIX@

Modules/CMakeClDeps.cmake

@@ -17,7 +17,7 @@
 # in front of each include path, so it can remove it.
 #
 
-IF(MSVC_C_ARCHITECTURE_ID AND CMAKE_GENERATOR MATCHES "Ninja" AND CMAKE_C_COMPILER)
+IF(MSVC_C_ARCHITECTURE_ID AND CMAKE_GENERATOR MATCHES "Ninja" AND CMAKE_C_COMPILER AND CMAKE_COMMAND)
   STRING(REPLACE "cmake.exe" "cmcldeps.exe"  CMAKE_CMCLDEPS_EXECUTABLE ${CMAKE_COMMAND})
   SET(showdir ${CMAKE_BINARY_DIR}/CMakeFiles/ShowIncludes)
   FILE(WRITE ${showdir}/foo.h "\n")
@@ -29,5 +29,6 @@ IF(MSVC_C_ARCHITECTURE_ID AND CMAKE_GENERATOR MATCHES "Ninja" AND CMAKE_C_COMPIL
   STRING(TOLOWER ${header1} header2)
   STRING(REPLACE ${header2} "" showOut2 ${showOut1})
   STRING(REPLACE "\n" "" showOut3 ${showOut2})
-  SET(CMAKE_CL_SHOWINCLUDE_PREFIX ${showOut3} CACHE STRING "cl.exe's /showInclides prefix" FORCE)
+  SET(SET_CMAKE_CMCLDEPS_EXECUTABLE   "SET(CMAKE_CMCLDEPS_EXECUTABLE \"${CMAKE_CMCLDEPS_EXECUTABLE}\")")
+  SET(SET_CMAKE_CL_SHOWINCLUDE_PREFIX "SET(CMAKE_CL_SHOWINCLUDE_PREFIX \"${showOut3}\")")
 ENDIF()