Re: [Qemu-devel] [PATCH] w32: Fix build with older gcc (unresolved symbol)

[Igor Mitsyanko]

On 11.05.2013 10:41, Stefan Weil wrote:
> Am 10.05.2013 22:14, schrieb Igor Mitsyanko:
> > On 29.03.2013 21:20, Stefan Weil wrote:
> > > The cross i586-mingw32msvc-gcc 4.4.4 from Debian Squeeze does not
> > > support
> > > __sync_val_compare_and_swap by default.
> > >
> > > Using -march=i686 fixes that and should also result in better code.
> > >
> > > Signed-off-by: Stefan Weil <address@hidden>
> > > ---
> > >
> > > Maybe this modification is also needed for native gcc-4.4 and older
> > > on Linux i386. If yes, we can move the new script code out of the
> > > MinGW conditional code.
> > >
> > > Newer versions of gcc obviously use -march=i686 by default and
> > > don't need the patch, but it also won't do any harm for those
> > > versions.
> > >
> > > Stefan
> > mingw is built with --build=mingw32 and looks like it defaults to
> > -march=i386 (I have gcc version 4.7.2).
> > Default build on windows is broken without this patch, it should be
> > applied to 1.5 probably.
> >
> > Tested-by: Igor Mitsyanko <address@hidden>
> With latest QEMU, -march=i486 is used and there should be no problem.
> If there still is a problem, we have to look for the reason.
>
> Could you please post the output from configure?
>
> Regards,
> Stefan

Right, looks like my configuration has __sync_fetch_and_and but doesn't 
have __sync_val_compare_and_swap. That's why configure check passes but 
build fails:

  LINK  arm-softmmu/qemu-system-armw.exe
../migration.o: In function `migrate_finish_set_state':
g:\qemu_develop_ws\qemu_upstream/migration.c:293: undefined reference to 
`__sync_val_compare_and_swap_4'
g:\qemu_develop_ws\qemu_upstream/migration.c:293: undefined reference to 
`__sync_val_compare_and_swap_4'
g:\qemu_develop_ws\qemu_upstream/migration.c:293: undefined reference to 
`__sync_val_compare_and_swap_4'
collect2.exe: error: ld returned 1 exit status
make[1]: *** [qemu-system-armw.exe] Error 1
make: *** [subdir-arm-softmmu] Error 2

configure.txt
Description: Text document