[Qemu-devel] ARM build error/warning

[Qemu-devel] ARM build error/warning

[Edgar E. Iglesias]

Hi,

Just a heads up.
I'm seeing a build warning/error on 32bit hosts.

I'm on:
commit dd089c0a1e928fb80ba8a37983c1b0e9232d1c8b
Merge: 42bf25a 30ef3c7
Author: Anthony Liguori <aliguori@amazon.com>
Date:   Sun Jan 12 17:50:52 2014 -0800

gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-2ubuntu1)

Best regards,
Edgar

make: Entering directory `/home/edgari/src/c/qemu/build-qemu'
  CC    aarch64-linux-user/target-arm/cpu.o
/home/edgari/src/c/qemu/qemu/target-arm/cpu.c: In function ‘arm_cpu_register_types’:
/home/edgari/src/c/qemu/qemu/target-arm/cpu.c:1049:5: error: comparison of unsigned expression < 0 is always false [-Werror=type-limits]

Re: [Qemu-devel] ARM build error/warning

[Peter Maydell]

On 13 January 2014 03:24, Edgar E. Iglesias <edgar.iglesias@gmail.com> wrote:
> Hi,
>
> Just a heads up.
> I'm seeing a build warning/error on 32bit hosts.
>
> I'm on:
> commit dd089c0a1e928fb80ba8a37983c1b0e9232d1c8b
> Merge: 42bf25a 30ef3c7
> Author: Anthony Liguori <aliguori@amazon.com>
> Date:   Sun Jan 12 17:50:52 2014 -0800
>
> gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-2ubuntu1)
>
> Best regards,
> Edgar
>
> make: Entering directory `/home/edgari/src/c/qemu/build-qemu'
>   CC    aarch64-linux-user/target-arm/cpu.o
> /home/edgari/src/c/qemu/qemu/target-arm/cpu.c: In function ‘arm_cpu_register_types’:
> /home/edgari/src/c/qemu/qemu/target-arm/cpu.c:1049:5: error: comparison of unsigned expression < 0 is always false [-Werror=type-limits]

Ah, this is because for the aarch64 linux-user target the
32-bit cpus array is empty.

I don't think it's a specific 32-bit hosts issue, it
presumably just depends on whether your C compiler complains
about it or not. I build with 4.6.3, which doesn't.

We had this with cpu64.c too (for a different reason) so
I think the best thing here is just to switch these two
arrays to loop until they hit a terminator rather than
using ARRAY_SIZE.

thanks
-- PMM