Adding a custom installation directory option to Autoconf-generated configure scripts

Question

configure scripts always include something like the following in the help message:

...
By default, `make install' will install all the files in
`/usr/local/bin', `/usr/local/lib' etc.  You can specify
an installation prefix other than `/usr/local' using `--prefix',
for instance `--prefix=$HOME'.

For better control, use the options below.

Fine tuning of the installation directories:
  --bindir=DIR            user executables [EPREFIX/bin]
  --sbindir=DIR           system admin executables [EPREFIX/sbin]
  --libexecdir=DIR        program executables [EPREFIX/libexec]
  --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
  --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
  --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
  --libdir=DIR            object code libraries [EPREFIX/lib]
  --includedir=DIR        C header files [PREFIX/include]
  --oldincludedir=DIR     C header files for non-gcc [/usr/include]
  --datarootdir=DIR       read-only arch.-independent data root [PREFIX/share]
  --datadir=DIR           read-only architecture-independent data [DATAROOTDIR]
  --infodir=DIR           info documentation [DATAROOTDIR/info]
  --localedir=DIR         locale-dependent data [DATAROOTDIR/locale]
  --mandir=DIR            man documentation [DATAROOTDIR/man]
  --docdir=DIR            documentation root
                          [DATAROOTDIR/doc/gedit-line-ending-style-plugin]
  --htmldir=DIR           html documentation [DOCDIR]
  --dvidir=DIR            dvi documentation [DOCDIR]
  --pdfdir=DIR            pdf documentation [DOCDIR]
  --psdir=DIR             ps documentation [DOCDIR]

Program names:
  --program-prefix=PREFIX            prepend PREFIX to installed program names
...

What I would like to do is add "plugindir", to this section, as in:

...
  --dvidir=DIR            dvi documentation [DOCDIR]
  --pdfdir=DIR            pdf documentation [DOCDIR]
  --psdir=DIR             ps documentation [DOCDIR]
  --plugindir=DIR         Gedit plugin files [LIBDIR/gedit-2/plugins]
...

so that users would be able to pass in --plugindir=... to the configure script.

How can I do this?

Vinita

Possible duplicate of Make install, but not to default directories? – Parisi

Answer 1

If I'm correct those paths are set in the share/autoconf/autoconf/general.m4 file. The list is hardcoded so it is difficult to insert things in the list. You can add extra help information using the macro AS_HELP_STRING. There are some examples that add a plugindir, for example in gstreamer, gimp, but those don't have a configurable plugin directory.

Leid

Interesting. Line 1058 of my /usr/share/autoconf/autoconf/general.m4 file is responsible for the "Fine tuning of the installation directories:" line. It does not, however, appear that I can easily add to the "installation directories" section of the configure script help text without modifying general.m4. But, at least I now know. – Vinita

I am not sure which approach of gstreamer and xine you are referring to. But, what I did was adapted a line from general.m4, adding AC_SUBST([plugindir], ['${libdir}/gedit-2/plugins']) to my configure.ac. Then, I specify targets that I want to install to the "plugindir" in the plugin_DATA variable in a Makefile.am. It's not as user-configurable as I was originally going for, but it works well: code.google.com/p/gedit-line-ending-style-plugin/source/browse/… – Vinita

Neither gstreamer nor xine do what the OP was asking. Both set the plugin path without any way for the user to specify. The only way I can see to allow the user to specify a plugin path at configure time is to abuse AC_ARG_WITH, which puts the documentation under "optional packages" rather than "fine tuning of the installation directories." – Winton

general.m4 is an internal file of autoconf, don't mess with it. The link is dead. But from what I see, everybody uses AC_ARG_WITH. Adding an argument without "with" or "enable" is impossible without modifying Autoconf. – Ensphere

Answer 2

Put the following lines in configure.ac, near the beginning:

AC_ARG_WITH([pkgconfigdir],
  [AS_HELP_STRING([--with-pkgconfigdir=DIR], [pkgconfig files])],
  [pkgconfigdir=$withval],
  [pkgconfigdir="\${libdir}/pkgconfig"])
AC_SUBST([pkgconfigdir], [$pkgconfigdir])

Then, in Makefile.am, you can refer to the directory like this:

pkgconfigdir = @pkgconfigdir@
pkgconfig_DATA = mylibrary.pc

Durbar

The second argument is not needed. pkgconfigdir = @pkgconfigdir@ is not needed. It's nice to specify the default in the help. You can use single quotes instead of escaping $. – Ensphere

Answer 3

I think you are on the right track with AC_SUBST.

Additionally, I think you can modify or extend the --help output of configure with AS_HELP_STRING.

See: http://www.gnu.org/s/hello/manual/autoconf/Pretty-Help-Strings.html

Rebecarebecca