+# Sync this with checkOS in configure.ac
+ @echo 'cTargetOS :: OS' >> $@
+ @echo '#if linux_TARGET_OS' >> $@
+ @echo 'cTargetOS = Linux' >> $@
+ @echo '#elif freebsd_TARGET_OS' >> $@
+ @echo 'cTargetOS = FreeBSD' >> $@
+ @echo '#elif netbsd_TARGET_OS' >> $@
+ @echo 'cTargetOS = NetBSD' >> $@
+ @echo '#elif openbsd_TARGET_OS' >> $@
+ @echo 'cTargetOS = OpenBSD' >> $@
+ @echo '#elif dragonfly_TARGET_OS' >> $@
+ @echo 'cTargetOS = OtherOS "dragonfly"' >> $@
+ @echo '#elif osf1_TARGET_OS' >> $@
+ @echo 'cTargetOS = OtherOS "osf"' >> $@
+ @echo '#elif osf3_TARGET_OS' >> $@
+ @echo 'cTargetOS = OtherOS "osf"' >> $@
+ @echo '#elif hpux_TARGET_OS' >> $@
+ @echo 'cTargetOS = HPUX' >> $@
+ @echo '#elif linuxaout_TARGET_OS' >> $@
+ @echo 'cTargetOS = Linux' >> $@
+ @echo '#elif kfreebsdgnu_TARGET_OS' >> $@
+ @echo 'cTargetOS = OtherOS "kfreebsdgnu"' >> $@
+ @echo '#elif freebsd2_TARGET_OS' >> $@
+ @echo 'cTargetOS = FreeBSD' >> $@
+ @echo '#elif solaris2_TARGET_OS' >> $@
+ @echo 'cTargetOS = Solaris' >> $@
+ @echo '#elif cygwin32_TARGET_OS' >> $@
+ @echo 'cTargetOS = Windows' >> $@
+ @echo '#elif mingw32_TARGET_OS' >> $@
+ @echo 'cTargetOS = Windows' >> $@
+ @echo '#elif darwin_TARGET_OS' >> $@
+ @echo 'cTargetOS = OSX' >> $@
+ @echo '#elif gnu_TARGET_OS' >> $@
+ @echo 'cTargetOS = OtherOS "gnu"' >> $@
+ @echo '#elif nextstep2_TARGET_OS' >> $@
+ @echo 'cTargetOS = OtherOS "nextstep"' >> $@
+ @echo '#elif nextstep3_TARGET_OS' >> $@
+ @echo 'cTargetOS = OtherOS "nextstep"' >> $@
+ @echo '#elif sunos4_TARGET_OS' >> $@
+ @echo 'cTargetOS = Solaris' >> $@
+ @echo '#elif ultrix_TARGET_OS' >> $@
+ @echo 'cTargetOS = OtherOS "ultrix"' >> $@
+ @echo '#elif irix_TARGET_OS' >> $@
+ @echo 'cTargetOS = IRIX' >> $@
+ @echo '#elif aix_TARGET_OS' >> $@
+ @echo 'cTargetOS = AIX' >> $@
+ @echo '#elif haiku_TARGET_OS' >> $@
+ @echo 'cTargetOS = OtherOS "haiku"' >> $@
+ @echo '#else' >> $@
+ @echo '#error Unknown target OS' >> $@
+ @echo '#endif' >> $@
+ @echo >> $@