Bring AC_SUBST(*_CFLAGS) and AC_SUBST(*_LIBS) in the same block of the
corresponding PKG_CHECK_MODULES() call.
Having these variables defined outside of the if tests is more than what
is needed as the corresponding PKG_CHECK_MODULES() might not have been
called at all there.
This is the same logic already used for USB_CFLAGS and USB_LIBS.
Call AC_SUBST unconditionally when specifying --with-* options,
otherwise options like --with-dbusconfdir=DIR or --with-udevdir=DIR have
no effect.
Before this change, configuring with:
$ mkdir build
$ ./configure --disable-systemd \
--prefix=$(pwd)/build \
--with-dbusconfdir=$(pwd)/build/etc
resulted in the option value to be ignored at "make install" time, with
this error:
/bin/mkdir: cannot create directory '/dbus-1/system.d': Permission denied
This is what was going on in configure.ac:
# define the option
AC_ARG_WITH([dbusconfdir] ... [path_dbusconfdir=${withval}])
# when --with-dbusconfdir is NOT used
if (test -z "${path_dbusconfdir}"); then
...
# define the config dir automatically
path_dbusconfdir="`$PKG_CONFIG --variable=sysconfdir dbus-1`"
...
# set DBUS_CONFDIR
AC_SUBST(DBUS_CONFDIR, [${path_dbusconfdir}])
endif
when --with-dbusconfdir=SOMEDIR was used the test above failed, and the
result was that ${path_dbusconfdir} was indeed defined as manually
specified, but DBUS_CONFDIR was not, and the latter was going to be used
in Makefile.am:
dbusdir = @DBUS_CONFDIR@/dbus-1/system.d
The failure in mkdir can be exposed by the use of the "--prefix" option
and by running "make install" as a normal user; when running "make
install" with the root user /dbus-1/system.d would be happily (and
wrongly) created.
By always setting variables relative to --with-* options (like
DBUS_CONFDIR) the cases when --with-someoption=SOMEDIR are used get
covered.
Instead of defining _GNU_SOURCE in each source file (and potentially
forgetting in some), tell the build system we use extensions and let it
define _GNU_SOURCE in config.h.
AM_PROG_MKDIR_P is deprecated since:
configure.ac:23: warning: The 'AM_PROG_MKDIR_P' macro is deprecated, and will soon be removed.
configure.ac:23: You should use the Autoconf-provided 'AC_PROG_MKDIR_P' macro instead,
configure.ac:23: and use '$(MKDIR_P)' instead of '$(mkdir_p)'in your Makefile.am files.
We are already using $(MKDIR_P) so we just need to call the right macro.
Udev is not meant to spawn long-running processes, and as of the next
udev version such processes will be killed.
If using systemd, device activation can be used to get the same effect.
On Arch we have been disabling this rule for a long time, even though we
don't use systemd, as it was causing more problems than it was worth.
