Midl CustomBuild _SelectedFiles;$(BisonDependsOn) %(Filename).tab.cpp %(Filename).tab.h start /B /WAIT /D "%(RootDir)%(Directory)" win_bison.exe [AllOptions] [AdditionalOptions] "%(Filename)%(Extension)" exit /b %errorlevel% %(RootDir)%(Directory)%(OutputFile); Process "%(Filename)%(Extension)" bison file