Re: About dynamic configure options.
Thanks guys, I actually sent a "solution" much like yours Nick. Don't know why Stefano didn't send my answer. This is what I came up with: AC_DEFUN([TRICK], [m4_divert_text([HELP_CANON], [_ACEOF echo -en "\n* --option=VALDate: `date`" cat <<\_ACEOF])]) TRICK You can see automake's archives for my whole message. Te code above will get hooked at the end of `HELP_CANON' (before the `heredoc' ends), or after the `Fine tuning' options if canonical support macros hasn't been called. Something that did surprise by looking at `general.m4' is that sections such as HELP_CANON, HELP_BEGIN, etc, have all been allocated sequentially, leaving no room for per-project customization. This is just my ignorant's opinion. I'm far from being a m4, autoconf, or automake specialist. Thanks, On 13/12/2012, Nick Bowler wrote: > On 2012-12-13 10:20 -0700, Eric Blake wrote: >> On 12/13/2012 05:58 AM, Stefano Lattarini wrote: >> > On 12/11/2012 12:57 AM, Eduardo Costa wrote: >> >> Is it possible at all to have a configure option whose help message can >> >> expand a >> >> variable, or can otherwise accept the output of a command at >> >> configure-time? >> >> >> >> For example, imagine this as part of the output of `./configure': >> >> >> >> --with-user=userWho to complain to (default X) >> >> >> >> Where X could be, say, the output of the command `whoami'. >> >> >> >> This might be done by usual means (couldn't do it) or just with some >> >> trickery to to inject the string manually at the end of some section >> >> (say HELP_CANON or other), and giving the output of the command on a >> >> new line, so it doesn't get inside the `cat << LABEL ... LABEL' >> >> constructs that seem to be used to output options and help messages. >> >> Unfortunately, it looks like the current setup of autoconf is pretty >> hard-coded to constant strings determined at m4-time; making it use >> shell variables for dynamic output would require quite a bit of patching >> (maybe by introducing new macros such as AC_ARG_WITH_UNQUOTED, to take >> care of the tweaks needed to close the quoted heredoc, open an unquoted >> heredoc to do the substitution, then reopen the quoted heredoc for the >> rest of the script). It sounds like a useful request, though. > > FWIW it's not too hard to hack it: > > AC_ARG_WITH([user], [_ACEOF > # Eschew error handling! > me=`whoami` > cat < m4_newline([AS_HELP_STRING([--with-user], >[Who to complain to (default $me)])])dnl > m4_newline([EOF]) > cat <<\_ACEOF]) > > but that is, of course, relying on internal details of how Autoconf > generates the code to produce --help output. But there remain other > problems: firstly, the --help text appears quite early in the configure > output -- much earlier than the position of AC_ARG_WITH in configure.ac > would imply. This may make it hard to put anything useful in the help > text, without computing it directly in AC_ARG_WITH_UNQUOTED or whatever > (as done in the above example). > > Secondly, regarding this specific example, I don't know if whoami is > universally available. So determining the default username is probably > within the realm of a "full" configure test, with at least one invocation > of AC_CHECK_PROGS. Such a test is almost certainly too much to do before > printing --help output. > > Normally it is sufficient to just write the --help text as a static > string explaining how the default is determined. In the case of a > username like above, I would probably do something like: > > --with-user=userWho to complain to (default: current user) > > and then make the configure script print a line such as: > > Checking which user will receive complaints... nbowler > > Cheers, > -- > Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/) > ___ Autoconf mailing list Autoconf@gnu.org https://lists.gnu.org/mailman/listinfo/autoconf
Re: About dynamic configure options.
On 2012-12-13 10:20 -0700, Eric Blake wrote: > On 12/13/2012 05:58 AM, Stefano Lattarini wrote: > > On 12/11/2012 12:57 AM, Eduardo Costa wrote: > >> Is it possible at all to have a configure option whose help message can > >> expand a > >> variable, or can otherwise accept the output of a command at > >> configure-time? > >> > >> For example, imagine this as part of the output of `./configure': > >> > >> --with-user=userWho to complain to (default X) > >> > >> Where X could be, say, the output of the command `whoami'. > >> > >> This might be done by usual means (couldn't do it) or just with some > >> trickery to to inject the string manually at the end of some section > >> (say HELP_CANON or other), and giving the output of the command on a > >> new line, so it doesn't get inside the `cat << LABEL ... LABEL' > >> constructs that seem to be used to output options and help messages. > > Unfortunately, it looks like the current setup of autoconf is pretty > hard-coded to constant strings determined at m4-time; making it use > shell variables for dynamic output would require quite a bit of patching > (maybe by introducing new macros such as AC_ARG_WITH_UNQUOTED, to take > care of the tweaks needed to close the quoted heredoc, open an unquoted > heredoc to do the substitution, then reopen the quoted heredoc for the > rest of the script). It sounds like a useful request, though. FWIW it's not too hard to hack it: AC_ARG_WITH([user], [_ACEOF # Eschew error handling! me=`whoami` cat
Re: About dynamic configure options.
On 12/13/2012 05:58 AM, Stefano Lattarini wrote: > Hi Eduardo. > > On 12/11/2012 12:57 AM, Eduardo Costa wrote: >> Hi, >> >> Is it possible at all to have a configure option whose help message can >> expand a >> variable, or can otherwise accept the output of a command at configure-time? >> >> For example, imagine this as part of the output of `./configure': >> >> --with-user=userWho to complain to (default X) >> >> Where X could be, say, the output of the command `whoami'. >> >> This might be done by usual means (couldn't do it) or just with some >> trickery to to inject the string manually at the end of some section >> (say HELP_CANON or other), and giving the output of the command on a >> new line, so it doesn't get inside the `cat << LABEL ... LABEL' >> constructs that seem to be used to output options and help messages. Unfortunately, it looks like the current setup of autoconf is pretty hard-coded to constant strings determined at m4-time; making it use shell variables for dynamic output would require quite a bit of patching (maybe by introducing new macros such as AC_ARG_WITH_UNQUOTED, to take care of the tweaks needed to close the quoted heredoc, open an unquoted heredoc to do the substitution, then reopen the quoted heredoc for the rest of the script). It sounds like a useful request, though. -- Eric Blake eblake redhat com+1-919-301-3266 Libvirt virtualization library http://libvirt.org signature.asc Description: OpenPGP digital signature ___ Autoconf mailing list Autoconf@gnu.org https://lists.gnu.org/mailman/listinfo/autoconf
Re: About dynamic configure options.
Hi Eduardo. On 12/11/2012 12:57 AM, Eduardo Costa wrote: > Hi, > > Is it possible at all to have a configure option whose help message can > expand a > variable, or can otherwise accept the output of a command at configure-time? > > For example, imagine this as part of the output of `./configure': > > --with-user=userWho to complain to (default X) > > Where X could be, say, the output of the command `whoami'. > > This might be done by usual means (couldn't do it) or just with some > trickery to to inject the string manually at the end of some section > (say HELP_CANON or other), and giving the output of the command on a > new line, so it doesn't get inside the `cat << LABEL ... LABEL' > constructs that seem to be used to output options and help messages. > > Thanks, > This question really pertains to Autoconf, not Automake. I'm thus forwarding it to the Autoconf list, where somebody might be willing to answer it (I haven't looked at it in detail, since I'm busy with other stuff right now; I might give it a shot in a few days maybe, but no promise). HTH, Stefano ___ Autoconf mailing list Autoconf@gnu.org https://lists.gnu.org/mailman/listinfo/autoconf
