Re: libdrm/amdgpu - Fixup typedef not to hide pointer type
Well thinking more about that what you probably could do is changing the
typedefs to put the pointer into a single element structure.
That should break only when somebody really abused the API and shouldn't
change the ABI.
Regards,
Christian.
Am 16.09.2016 um 11:12 schrieb Christian König:
Am 16.09.2016 um 11:02 schrieb Edward O'Callaghan:
Hi Christian,
On 09/16/2016 06:49 PM, Christian König wrote:
NAK, that is clearly an API breakage.
It should have never been typedef'ed in the first place. Does that mean
we would have to bump version for API change? What is the procedure
there?
Keep it as it is, you can't change it even if we bump the version
number you would break existing userspace.
BTW: Why would we want to stop hiding the type?
Quite a few reasons, I'll start with to justify the change:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/CodingStyle?id=refs/tags/v4.8-rc6#n276
This doesn't apply here, this is a user space library interface and
not the kernel.
The structure types are not defined outside of the library and so you
can't dereference or NULL check them.
Regards,
Christian.
Suppose you have 'amdgpu_semaphore_handle' as typedef of a pointer type
and you had some function 'void f(amdgpu_semaphore_handle * h) {}'.
Suppose now, within 'f()' we deference 'h' and use the result in some
way. The issue is that it is not directly obvious that we have a double
pointer type and so while it maybe the case that '(*h != NULL)' it could
well be the case that '(h == NULL)'.
Kind Regards,
Edward.
Christian.
Am 16.09.2016 um 10:46 schrieb Edward O'Callaghan:
Oops, turns out I mailed to dri-devel by mistake so resending here.
The following series fixes up libdrm/amdgpu such that to not hide
a pointer type behind a typedef.
Please Review,
Edward O'Callaghan (3):
[PATCH 1/3] amdgpu: Fix amdgpu_va_handle typedef not to hide
pointer
[PATCH 2/3] amdgpu: Fix amdgpu_semaphore_handle typedef not to hide
[PATCH 3/3] amdgpu: Fix amdgpu_bo_list_handle typedef not to hide
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Re: libdrm/amdgpu - Fixup typedef not to hide pointer type
Am 16.09.2016 um 11:02 schrieb Edward O'Callaghan:
Hi Christian,
On 09/16/2016 06:49 PM, Christian König wrote:
NAK, that is clearly an API breakage.
It should have never been typedef'ed in the first place. Does that mean
we would have to bump version for API change? What is the procedure there?
Keep it as it is, you can't change it even if we bump the version number
you would break existing userspace.
BTW: Why would we want to stop hiding the type?
Quite a few reasons, I'll start with to justify the change:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/CodingStyle?id=refs/tags/v4.8-rc6#n276
This doesn't apply here, this is a user space library interface and not
the kernel.
The structure types are not defined outside of the library and so you
can't dereference or NULL check them.
Regards,
Christian.
Suppose you have 'amdgpu_semaphore_handle' as typedef of a pointer type
and you had some function 'void f(amdgpu_semaphore_handle * h) {}'.
Suppose now, within 'f()' we deference 'h' and use the result in some
way. The issue is that it is not directly obvious that we have a double
pointer type and so while it maybe the case that '(*h != NULL)' it could
well be the case that '(h == NULL)'.
Kind Regards,
Edward.
Christian.
Am 16.09.2016 um 10:46 schrieb Edward O'Callaghan:
Oops, turns out I mailed to dri-devel by mistake so resending here.
The following series fixes up libdrm/amdgpu such that to not hide
a pointer type behind a typedef.
Please Review,
Edward O'Callaghan (3):
[PATCH 1/3] amdgpu: Fix amdgpu_va_handle typedef not to hide pointer
[PATCH 2/3] amdgpu: Fix amdgpu_semaphore_handle typedef not to hide
[PATCH 3/3] amdgpu: Fix amdgpu_bo_list_handle typedef not to hide
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Re: libdrm/amdgpu - Fixup typedef not to hide pointer type
Hi Christian,
On 09/16/2016 06:49 PM, Christian König wrote:
> NAK, that is clearly an API breakage.
It should have never been typedef'ed in the first place. Does that mean
we would have to bump version for API change? What is the procedure there?
>
> BTW: Why would we want to stop hiding the type?
Quite a few reasons, I'll start with to justify the change:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/CodingStyle?id=refs/tags/v4.8-rc6#n276
Suppose you have 'amdgpu_semaphore_handle' as typedef of a pointer type
and you had some function 'void f(amdgpu_semaphore_handle * h) {}'.
Suppose now, within 'f()' we deference 'h' and use the result in some
way. The issue is that it is not directly obvious that we have a double
pointer type and so while it maybe the case that '(*h != NULL)' it could
well be the case that '(h == NULL)'.
Kind Regards,
Edward.
>
> Christian.
>
> Am 16.09.2016 um 10:46 schrieb Edward O'Callaghan:
>> Oops, turns out I mailed to dri-devel by mistake so resending here.
>>
>> The following series fixes up libdrm/amdgpu such that to not hide
>> a pointer type behind a typedef.
>>
>> Please Review,
>>
>> Edward O'Callaghan (3):
>> [PATCH 1/3] amdgpu: Fix amdgpu_va_handle typedef not to hide pointer
>> [PATCH 2/3] amdgpu: Fix amdgpu_semaphore_handle typedef not to hide
>> [PATCH 3/3] amdgpu: Fix amdgpu_bo_list_handle typedef not to hide
>> ___
>> amd-gfx mailing list
>> amd-gfx@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
>
>
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Re: libdrm/amdgpu - Fixup typedef not to hide pointer type
NAK, that is clearly an API breakage. BTW: Why would we want to stop hiding the type? Christian. Am 16.09.2016 um 10:46 schrieb Edward O'Callaghan: Oops, turns out I mailed to dri-devel by mistake so resending here. The following series fixes up libdrm/amdgpu such that to not hide a pointer type behind a typedef. Please Review, Edward O'Callaghan (3): [PATCH 1/3] amdgpu: Fix amdgpu_va_handle typedef not to hide pointer [PATCH 2/3] amdgpu: Fix amdgpu_semaphore_handle typedef not to hide [PATCH 3/3] amdgpu: Fix amdgpu_bo_list_handle typedef not to hide ___ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx ___ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx
