Re: [Qemu-devel] [PATCH 2/4] monitor: remove target-specific code from monitor.c

[Pavel Butsykin <pbutsykin@odin.com>]

On 08.09.2015 13:13, Fam Zheng wrote:
> On Tue, 09/08 11:54, Paolo Bonzini wrote:
>>
>> On 08/09/2015 09:09, Denis V. Lunev wrote:
>>>   qemu-monitor-info.texi           | 151 +++++++
>> This should be added in patch 4, not now.
>>
>>> +const MonitorDef *target_monitor_defs(void) __attribute__((weak));
>>> +
>>> +const MonitorDef *target_monitor_defs(void)
>>> +{
>>> +    return NULL;
>>> +}
>> Weak symbols do not work on all platforms.  Luckily, making libqemustub
>> a static library gets exactly the same result without the need for weak
>> symbols: the definition from the QEMU object files will hide the stub.
>>
>> You just need to remove __attribute__((weak)), and it should just work.
>>
>> Otherwise, the patches look good to me.  Luiz, do you have time to post
>> a pull request for v4, or do you want to pass HMP maintainership as well
>> to someone else?
> Didn't look at the patch, but Patchew is catching this for cross build:
>
> running command: /tmp/qemu-build/configure --prefix=/var/tmp/qemu-build-install --cross-prefix=x86_64-w64-mingw32- --target-list=x86_64-softmmu,aarch64-softmmu ...
> running command: make -j2 ...
> Failed:
> [snip]
>    CC    aarch64-softmmu/target-arm/kvm-stub.o
>    CC    aarch64-softmmu/target-arm/translate.o
>    CC    aarch64-softmmu/target-arm/op_helper.o
>    CC    aarch64-softmmu/target-arm/helper.o
>    CC    aarch64-softmmu/target-arm/cpu.o
>    CC    aarch64-softmmu/target-arm/neon_helper.o
>    CC    aarch64-softmmu/target-arm/iwmmxt_helper.o
>    CC    aarch64-softmmu/target-arm/gdbstub.o
>    CC    aarch64-softmmu/target-arm/psci.o
>    CC    aarch64-softmmu/target-arm/cpu64.o
>    CC    aarch64-softmmu/target-arm/translate-a64.o
>    CC    aarch64-softmmu/target-arm/helper-a64.o
>    CC    aarch64-softmmu/target-arm/gdbstub64.o
>    CC    aarch64-softmmu/target-arm/crypto_helper.o
>    GEN   trace/generated-helpers.c
>    CC    aarch64-softmmu/gdbstub-xml.o
>    CC    aarch64-softmmu/trace/generated-helpers.o
>    LINK  aarch64-softmmu/qemu-system-aarch64w.exe
> monitor.o: In function `get_monitor_def':
> /tmp/qemu-build/monitor.c:2091: undefined reference to `target_monitor_defs'
> collect2: error: ld returned 1 exit status
> Makefile:184: recipe for target 'qemu-system-aarch64w.exe' failed
> make[1]: *** [qemu-system-aarch64w.exe] Error 1
> Makefile:179: recipe for target 'subdir-aarch64-softmmu' failed
> make: *** [subdir-aarch64-softmmu] Error 2
As it turned out, this reaction occurs when using a weak symbol.