ENH: use full source name for c code as well as c++

Source/cmUnixMakefileGenerator.cxx

@@ -1457,7 +1457,10 @@ void cmUnixMakefileGenerator::OutputSourceObjectBuildRules(std::ostream& fout)
               {
               compileCommand += "$(CMAKE_SHLIB_CFLAGS) ";
               }
-            compileCommand += "$(INCLUDE_FLAGS) -c $< -o $@";
+            compileCommand += "$(INCLUDE_FLAGS) -c ";
+            compileCommand += source->GetFullPath();
+            compileCommand +=+ " -o ";
+            compileCommand += objectFile;
             }
           else
             {