[OE-core] Link issue of virglrenderer on x86 with gcc options '-O2 -fvisibility=default'

[Kang Kai]

On 2019/4/3 上午12:16, Khem Raj wrote:
> On Tue, Apr 2, 2019 at 8:46 AM Kang Kai <Kai.Kang at windriver.com> wrote:
>> Hi Raj,
>>
>> I meet a link problem of virglrenderer with gcc options '-O2
>> -fvisibility=default' configured in local.conf:
>>
>> SELECTED_OPTIMIZATION = "-O2 -fvisibility=default"
>>
>> It fails on qemux86 but succeeds on x86-64.
>>
>> And the error message:
>>
>> | i586-poky-linux-libtool: link: i586-poky-linux-gcc  -m32 -march=i586
>> -fstack-protector-strong  -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security
>> -Werror=
>> format-security
>> --sysroot=/home/kkang/buildarea/Yocto/build-systemd/tmp/work/i586-poky-linux/virglrenderer/0.7.0-r0/recipe-sysroot
>> -shared  -fPIC -DPIC
>>    .libs/virglrenderer.o  *-Wl,--whole-archive* ./.libs/libvrend.a
>> gallium/auxiliary/.libs/libgallium.a *-Wl,--no-whole-archive*  -lm -ldrm
>> -lgbm -lepoxy -lX1
>> 1  -m32 -march=i586 -fstack-protector-strong
>> --sysroot=/home/kkang/buildarea/Yocto/build-systemd/tmp/work/i586-poky-linux/virglrenderer/0.7.0-r0/recipe-
>> sysroot -O2 -Wl,-Bsymbolic -Wl,-O1 -Wl,--hash-style=gnu -Wl,--as-needed
>> -fstack-protector-strong -Wl,-z -Wl,relro -Wl,-z -Wl,now   -pthread
>> -Wl,-soname
>> -Wl,libvirglrenderer.so.0 -o .libs/libvirglrenderer.so.0.2.0
>> |
>> /home/kkang/buildarea/Yocto/build-systemd/tmp/work/i586-poky-linux/virglrenderer/0.7.0-r0/recipe-sysroot-native/usr/bin/i586-poky-linux/../../libexec/
>> i586-poky-linux/gcc/i586-poky-linux/8.3.0/ld:
>> gallium/auxiliary/.libs/libgallium.a(u_cpu_detect.o): relocation
>> R_386_GOTOFF against undefined symbol `ut
>> il_cpu_caps' can not be used when making a shared object
>>
>> It could pass if options -Wl,--whole-archive and -Wl,--no-whole-archive
>> are removed.
>>
>> It says 'relocation R_386_GOTOFF' but when I check the file, it shows
>> relocation type is R_386_GOT32X:
>>
>> $ readelf --relocs ./util/.libs/u_cpu_detect.o | grep util_cpu_caps
>> 00000092  0000102b R_386_GOT32X      00000004   util_cpu_caps
>>
>> AFAIK R_386_GOT32X is not used with PIC. But I don't know why the type
>> is R_386_GOT32X that -fPIC has been applied already?
>>
>> Any suggestion is great appreciated. Thanks.
>>
> it seems you have to build PIC archive for libgallium.a, it might not
> be using the right -fPIC flags during compile/link phase.

Hi Raj,

Thanks a lot.

It turns out that caused by link option '-Bsymbolic'. Replace with 
'-Bdynamic' could resolve the issue. And I'll send a patch to upstream.


Regards,
Kai


>
>> --
>> Kai Kang
>>

-- 
Kai Kang