On 02 Jan 2008 08:54:39 -0800, Ian Lance Taylor <iant@xxxxxxxxxx> wrote: > NightStrike <nightstrike@xxxxxxxxx> writes: > > > I noticed that --with-sysroot is not listed in --help for the top > > level configure, but --with-build-sysroot is. Is that on purpose? > > Should the former not be used at all in place of the latter? > > This is an unfortunate artifact of autoconf --help handling with > recursive configure scripts. You'll see both mentioned in the output > of gcc/configure --help. --with-build-sysroot needs to be handled at > the top level in order to pass down the --sysroot option when > compiling libraries; therefore, it appears in the top level --help > output. --with-sysroot does not need to be handled at the top level; > therefore, it does not appear in the top level --help output. If that's the case, there must be more options as well that are not present in top level's --help that really are options that the user would actually use. I would think that a simple AS_HELP_STRING macro in the top level configure would accomplish this. That, or a blank ARG_WITH macro.. something like: AC_ARG_WITH([sysroot], [AS_HELP_STRING([--with-sysroot], [Sets the sysroot])], [], []) You could list the option in the top level configure, but give it no action. This is a benefit to the user, so that the top level configure --help contains all the options that a user would use.