build: generate libkmod.pc during autoconf

The pkgconfig file is generated at make-time, leading to absolute /usr/include & /usr/lib search paths. The patch lets autoconf handle pkgconfig file subst, like other packages do. (Patch from OpenWrt's contributed packages project.)

---
 Makefile.am  | 3 ---
 configure.ac | 1 +
 2 files changed, 1 insertion(+), 3 deletions(-)

index caf18b6..32aea73 100644
@@ -36,9 +36,6 @@ SED_PROCESS = \
 	-e 's,@zlib_LIBS\@,${zlib_LIBS},g' \
 	< $< > $@ || rm $@
 
-%.pc: %.pc.in Makefile
-	$(SED_PROCESS)
-
 LIBKMOD_CURRENT=4
 LIBKMOD_REVISION=10
 LIBKMOD_AGE=2

index be597b4..8500cad 100644
@@ -250,6 +250,7 @@ AC_SUBST([OUR_LDFLAGS], $with_ldflags)
 AC_CONFIG_FILES([
 	Makefile
 	man/Makefile
+	libkmod/libkmod.pc
 	libkmod/docs/Makefile
 	libkmod/docs/version.xml
 ])

1.9.1

Hi Jeff,

what exactly are you solving here? What's the problem with doing it during make not during configure?
We have it in Makefile.am exactly so it's processed by make, not configure. Make runs after configure so it will use whatever is configured to make the substitution.

$ ./configure --includedir=/tmp/bla
$ make
$ grep includedir= ./libkmod/libkmod.pc
$ includedir=/tmp/bla

others do like we do, too:
https://git.kernel.org/cgit/linux/kernel/git/kay/libabc.git/tree/Makefile.am
http://cgit.freedesktop.org/systemd/systemd/tree/Makefile.am

should they be changed, too?

Lucas De Marchi

Hi Lucas,

It certainly affects cross-compiling. Possibly other stuff.

Here's the relevant part of libkmod.pc when produced during make:

prefix=/usr
exec_prefix=/usr
libdir=/usr/lib
includedir=/usr/include

And during configure:

prefix=/usr
exec_prefix=/usr
libdir=${exec_prefix}/lib
includedir=${prefix}/include

Yes! I was just about to send a fix for systemd, as that burned me too. :-)

(If you check any of the libraries on git.gnome.org, their pkg-config files are generated during configure.)

Thanks,
Jeff

Hi Lucas,

It certainly affects cross-compiling. Possibly other stuff.

Here's the relevant part of libkmod.pc when produced during make:

prefix=/usr
exec_prefix=/usr
libdir=/usr/lib
includedir=/usr/include

And during configure:

prefix=/usr
exec_prefix=/usr
libdir=${exec_prefix}/lib
includedir=${prefix}/include

Yes! I was just about to send a fix for systemd, as that burned me too. :-)

(If you check any of the libraries on git.gnome.org, their pkg-config files are generated during configure.)

Thanks,
Jeff