On Fri, Aug 22, 2014 at 9:20 AM, Daniel P. Berrange <berra...@redhat.com> wrote: > On Thu, Aug 21, 2014 at 08:10:54PM -0400, John Snow wrote: >> I was running a series of tests on 32 and 64 bit hosts to test for >> endianness and variable width issues when I noticed that I couldn't properly >> perform a build of "make check" against a 32bit target from a 64bit host: >> >> ../../configure --cpu=i386 && make -j4 && make check >> >> This produces some warnings in tests-cutils about overflowing variables that >> are of type guint64. It's been mentioned on the mailing lists before, >> actually: http://lists.gnu.org/archive/html/qemu-devel/2014-05/msg00452.html >> >> The problem is that guint64 is being aliased against "unsigned long", which >> is only 4 bytes instead of the implied 8. This occurs because we link >> against the 64bit headers for glib instead of the 32bit ones when we're >> building for i386 from an x86_64 host. >> >> Our include flags wind up looking like: -I/usr/include/glib-2.0 but >> -I/usr/lib64/glib-2.0/include >> >> I was discussing the problem with Stefan: >> >> On 08/21/2014 05:03 AM, Stefan Hajnoczi wrote: >> >The problem is that pkg-config uses libdir=/usr/lib64 by default on >> >amd64 hosts. It doesn't know that gcc -m32 is being used. >> > >> >This results in glib's 64-bit headers being used where guint64 is just >> >unsigned long. On 32-bit hosts this is incorrect. >> > >> >Two workarounds: >> > >> >1. yum install pkgconfig.i686 and run it instead of pkgconfig.x86_64 >> > >> >2. Use the pkg-config --define-variable libdir=/usr/lib option >> > >> >You can set PKG_CONFIG=path/to/pkg-config.i686 on QEMU's ./configure >> >command-line. >> > >> >This is all distro-specific :(. Any other solutions? >> > >> >Stefan >> > >> >> I am not extremely well versed in configure or pkg-config ninjutsu, but I >> must imagine that the ARCH/cpu variables we are setting in configure could >> help us know to call the 32bit pkg-config instead of the native 64bit >> version and fix this issue. >> >> Does anyone have any good ideas? Surely other projects must have run into >> this elsewhere. > > Distros will install pkg-config .pc files for non-native architectures > in a different location normally. The supported / recommended way to > tell pkg-config to look in these alternative dirs is to set the env > variable PKG_CONFIG_LIBDIR. This replaces the built-in default search > directory that looks for native. > > So on a Fedora / RHELL system, to make pkg-config use 32-bit libs you > want to set > > PKG_CONFIG_LIBDIR=/usr/lib/pkgconfig > > which replaces the default location of /usr/lib64/pkgconfig.
Nice, and Paolo sent me an automated way of doing that: On Fri, Aug 22, 2014 at 12:14:28AM +0200, Paolo Bonzini wrote: > You need to set PKG_CONFIG_LIBDIR to > > /usr/lib/$MULTILIBDIR/pkgconfig > > where MULTILIBDIR is > > if $CC -print-multiarch >/dev/null 2>&1; then > MULTILIBDIR=`$CC -print-multiarch $CFLAGS $CPPFLAGS` > fi > if test -z "$MULTILIBDIR"; then > MULTILIBDIR=`$CC --print-multi-os-directory $CFLAGS $CPPFLAGS` > fi > > This will point at /usr/lib/pkgconfig/glib-2.0.pc instead of > /usr/lib64/pkgconfig/glib-2.0.pc I tested that it works. Stefan
