On Mon, Jan 25, 2016 at 02:42:10PM +0000, Peter Maydell wrote: > On 13 November 2015 at 11:31, Daniel P. Berrange <berra...@redhat.com> wrote: > > Developers on 64-bit machines will often try to perform a > > 32-bit build of QEMU by running > > > > ./configure --extra-cflags="-m32" > > > > Unfortunately if PKG_CONFIG_LIBDIR is not set to point to > > the location of the 32-bit pkg-config files, then configure > > will silently pick up the 64-bit pkg-config files and still > > succeed. > > > > This causes a problem for glib because it means QEMU will > > be pulling in /usr/lib64/glib-2.0/include/glibconfig.h > > instead of /usr/lib/glib-2.0/include/glibconfig.h > > > > This causes problems because the 'gsize' type (defined as > > 'unsigned long') will no longer be fully compatible with > > the 'size_t' type (defined as 'unsigned int'). Although > > both are the same size, the compiler refuses to allow > > casts from 'unsigned long *' to 'unsigned int *' as they > > are different pointer types. This results in non-obvious > > compiler errors when building QEMU eg > > > > qga/commands-posix.c: In function ‘qmp_guest_set_user_password’: > > qga/commands-posix.c:1912:55: error: passing argument 2 of > > ‘g_base64_decode’ from incompatible pointer type > > [-Werror=incompatible-pointer-types] > > rawpasswddata = (char *)g_base64_decode(password, &rawpasswdlen); > > ^ > > In file included from /usr/include/glib-2.0/glib.h:35:0, > > from qga/commands-posix.c:14: > > /usr/include/glib-2.0/glib/gbase64.h:52:9: note: expected ‘gsize * {aka > > long unsigned int *}’ but argument is of type ‘size_t * {aka unsigned int > > *}’ > > guchar *g_base64_decode (const gchar *text, > > ^ > > cc1: all warnings being treated as errors > > > > To detect this problem, add a check to configure that > > verifies that GLIB_SIZEOF_SIZE_T matches sizeof(size_t). > > If this fails print a warning suggesting that the dev > > probably needs to set PKG_CONFIG_LIBDIR. > > > > On Fedora x86_64 it passes with any of: > > > > # ./configure > > # PKG_CONFIG_LIBDIR=/usr/lib/pkgconfig ./configure --extra-cflags="-m32" > > # PKG_CONFIG_LIBDIR=/usr/lib64/pkgconfig ./configure --extra-cflags="-m64" > > > > And fails with a mis-match > > > > # PKG_CONFIG_LIBDIR=/usr/lib64/pkgconfig ./configure --extra-cflags="-m32" > > # PKG_CONFIG_LIBDIR=/usr/lib/pkgconfig ./configure --extra-cflags="-m64" > > > > ERROR: sizeof(size_t) doesn't match GLIB_SIZEOF_SIZE_T. > > You probably need to set PKG_CONFIG_LIBDIR > > to point to the right pkg-config files for your > > build target > > > > Signed-off-by: Daniel P. Berrange <berra...@redhat.com> > > I just noticed this never got applied to master -- did it just fall through > the cracks, or is there an issue with it?
AFAIK, no one raised a blocking issue with it. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|