On Sat, Nov 18, 2006 at 11:18:14AM +0100, Georg Baum wrote:
> I use debian unstable, and the autoconf from sarge. That works fine. If you
> have a bit of autoconf knowledge it would be really great if you could
> review our Makefile.am's and find out whether we need to change anything
> (somebody posted a list of things to look for in one of the old threads).
The autoconf 2.60 announcement warns about this:
* Some directory variables have been added, and others adjusted to
changes in the GNU Coding Standards. If your package expands
'$datadir', '$infodir', or '$mandir' anywhere, you need to check your
package, and possibly adjust it accordingly. The nodes 'Changed
Directory Variables' and 'Defining Directories' in the manual have
more information; be sure to read them.
I report below the contents of the two nodes mentioned above.
ATM I have no time to look at this, though.
4.7.3 Changed Directory Variables
---------------------------------
In Autoconf 2.60, the set of directory variables has changed, and the
defaults of some variables have been adjusted (*note Installation
Directory Variables::) to changes in the GNU Coding Standards.
Notably, `datadir', `infodir', and `mandir' are now expressed in terms
of `datarootdir'. If you are upgrading from an earlier Autoconf
version, you may need to adjust your files to ensure that the directory
variables are substituted correctly (*note Defining Directories::), and
that a definition of `datarootdir' is in place. For example, in a
`Makefile.in', adding
datarootdir = @datarootdir@
is usually sufficient. If you use Automake to create `Makefile.in', it
will add this for you.
To help with the transition, Autoconf warns about files that seem to
use `datarootdir' without defining it. In some cases, it then expands
the value of `$datarootdir' in substitutions of the directory
variables. The following example shows such a warning:
$ cat configure.ac
AC_INIT
AC_CONFIG_FILES([Makefile])
AC_OUTPUT
$ cat Makefile.in
prefix = @prefix@
datadir = @datadir@
$ autoconf
$ configure
configure: creating ./config.status
config.status: creating Makefile
config.status: WARNING:
Makefile.in seems to ignore the --datarootdir setting
$ cat Makefile
prefix = /usr/local
datadir = ${prefix}/share
Usually one can easily change the file to accommodate both older and
newer Autoconf releases:
$ cat Makefile.in
prefix = @prefix@
datarootdir = @datarootdir@
datadir = @datadir@
$ configure
configure: creating ./config.status
config.status: creating Makefile
$ cat Makefile
prefix = /usr/local
datarootdir = ${prefix}/share
datadir = ${datarootdir}
In some cases, however, the checks may not be able to detect that a
suitable initialization of `datarootdir' is in place, or they may fail
to detect that such an initialization is necessary in the output file.
If, after auditing your package, there are still spurious `configure'
warnings about `datarootdir', you may add the line
AC_DEFUN([AC_DATAROOTDIR_CHECKED])
to your `configure.ac' to disable the warnings. This is an exception
to the usual rule that you should not define a macro whose name begins
with `AC_' (*note Macro Names::).
19.5 How Do I `#define' Installation Directories?
=================================================
My program needs library files, installed in `datadir' and
similar. If I use
AC_DEFINE_UNQUOTED([DATADIR], [$datadir],
[Define to the read-only architecture-independent
data directory.])
I get
#define DATADIR "${prefix}/share"
As already explained, this behavior is on purpose, mandated by the GNU
Coding Standards, see *Note Installation Directory Variables::. There
are several means to achieve a similar goal:
- Do not use `AC_DEFINE' but use your makefile to pass the actual
value of `datadir' via compilation flags. *Note Installation
Directory Variables::, for the details.
- This solution can be simplified when compiling a program: you may
either extend the `CPPFLAGS':
CPPFLAGS = -DDATADIR='"$(datadir)"' @CPPFLAGS@
or create a dedicated header file:
DISTCLEANFILES = datadir.h
datadir.h: Makefile
echo '#define DATADIR "$(datadir)"' >$@
- Use `AC_DEFINE' but have `configure' compute the literal value of
`datadir' and others. Many people have wrapped macros to automate
this task. For instance, the macro `AC_DEFINE_DIR' from the
Autoconf Macro Archive (http://autoconf-archive.cryp.to/).
This solution does not conform to the GNU Coding Standards.
- Note that all the previous solutions hard wire the absolute name of
these directories in the executables, which is not a good
property. You may try to compute the names relative to `prefix',
and try to find `prefix' at runtime, this way your package is
relocatable. Some macros are already available to address this
issue: see `adl_COMPUTE_RELATIVE_PATHS' and
`adl_COMPUTE_STANDARD_RELATIVE_PATHS' on the Autoconf Macro
Archive (http://autoconf-archive.cryp.to/).
--
Enrico
