[FFmpeg-devel] [PATCH] avutil/opencl: add av_warn_unused_result

[Ganesh Ajjanagadde]

On Fri, Oct 16, 2015 at 8:02 AM, Ganesh Ajjanagadde
<gajjanagadde at gmail.com> wrote:
> On Thu, Oct 15, 2015 at 11:17 PM, highgod0401 <highgod0401 at gmail.com> wrote:
>>
>> From: Ganesh Ajjanagadde
>> Date: 2015-10-16 08:08
>> To: ffmpeg-devel
>> CC: Ganesh Ajjanagadde
>> Subject: [FFmpeg-devel] [PATCH] avutil/opencl: add av_warn_unused_result
>> This will trigger a few warnings. My config does not compile the opencl
>> code, so this is untested.
>>
>> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
>> ---
>>  libavutil/opencl.h | 10 ++++++++++
>>  1 file changed, 10 insertions(+)
>>
>> diff --git a/libavutil/opencl.h b/libavutil/opencl.h
>> index e423e55..6a5b0ab 100644
>> --- a/libavutil/opencl.h
>> +++ b/libavutil/opencl.h
>> @@ -81,6 +81,7 @@ typedef struct {
>>   *
>>   * @return  >=0 on success, a negative error code in case of failure
>>   */
>> +av_warn_unused_result
>>  int av_opencl_get_device_list(AVOpenCLDeviceList **device_list);
>>
>>  /**
>> @@ -108,6 +109,7 @@ void av_opencl_free_device_list(AVOpenCLDeviceList
>> **device_list);
>>   * @return >=0 on success, a negative error code in case of failure
>>   * @see av_opencl_get_option()
>>   */
>> +av_warn_unused_result
>>  int av_opencl_set_option(const char *key, const char *val);
>>
>>  /**
>> @@ -119,6 +121,7 @@ int av_opencl_set_option(const char *key, const char
>> *val);
>>   * @return  >=0 on success, a negative error code in case of failure
>>   * @see av_opencl_set_option()
>>   */
>> +av_warn_unused_result
>>  int av_opencl_get_option(const char *key, uint8_t **out_val);
>>
>>  /**
>> @@ -161,6 +164,7 @@ const char *av_opencl_errstr(cl_int status);
>>   * @param kernel_code    kernel code to be compiled in the OpenCL runtime
>> environment
>>   * @return  >=0 on success, a negative error code in case of failure
>>   */
>> +av_warn_unused_result
>>  int av_opencl_register_kernel_code(const char *kernel_code);
>>
>>  /**
>> @@ -170,6 +174,7 @@ int av_opencl_register_kernel_code(const char
>> *kernel_code);
>>   *                       application program, ignored if set to NULL
>>   * @return >=0 on success, a negative error code in case of failure
>>   */
>> +av_warn_unused_result
>>  int av_opencl_init(AVOpenCLExternalEnv *ext_opencl_env);
>>
>>  /**
>> @@ -205,6 +210,7 @@ cl_command_queue av_opencl_get_command_queue(void);
>>   * @param host_ptr     host pointer of the OpenCL buffer
>>   * @return >=0 on success, a negative error code in case of failure
>>   */
>> +av_warn_unused_result
>>  int av_opencl_buffer_create(cl_mem *cl_buf, size_t cl_buf_size, int flags,
>> void *host_ptr);
>>
>>  /**
>> @@ -215,6 +221,7 @@ int av_opencl_buffer_create(cl_mem *cl_buf, size_t
>> cl_buf_size, int flags, void
>>   * @param buf_size          size in bytes of the source and destination
>> buffers
>>   * @return >=0 on success, a negative error code in case of failure
>>   */
>> +av_warn_unused_result
>>  int av_opencl_buffer_write(cl_mem dst_cl_buf, uint8_t *src_buf, size_t
>> buf_size);
>>
>>  /**
>> @@ -225,6 +232,7 @@ int av_opencl_buffer_write(cl_mem dst_cl_buf, uint8_t
>> *src_buf, size_t buf_size)
>>   * @param buf_size          size in bytes of the source and destination
>> buffers
>>   * @return >=0 on success, a negative error code in case of failure
>>   */
>> +av_warn_unused_result
>>  int av_opencl_buffer_read(uint8_t *dst_buf, cl_mem src_cl_buf, size_t
>> buf_size);
>>
>>  /**
>> @@ -240,6 +248,7 @@ int av_opencl_buffer_read(uint8_t *dst_buf, cl_mem
>> src_cl_buf, size_t buf_size);
>>   * @param src_plane_num      number of source image planes
>>   * @return >=0 on success, a negative error code in case of failure
>>   */
>> +av_warn_unused_result
>>  int av_opencl_buffer_write_image(cl_mem dst_cl_buf, size_t cl_buffer_size,
>> int dst_cl_offset,
>>                                   uint8_t **src_data, int *plane_size, int
>> plane_num);
>>
>> @@ -253,6 +262,7 @@ int av_opencl_buffer_write_image(cl_mem dst_cl_buf,
>> size_t cl_buffer_size, int d
>>   * @param src_cl_buf_size    size in bytes of OpenCL buffer
>>   * @return >=0 on success, a negative error code in case of failure
>>   */
>> +av_warn_unused_result
>>  int av_opencl_buffer_read_image(uint8_t **dst_data, int *plane_size, int
>> plane_num,
>>                                  cl_mem src_cl_buf, size_t cl_buffer_size);
>>
>> --
>> 2.6.1
>>
>> Hi
>>
>> Could I ask a question? Why should we add the av_warn_unused_result?
>
> It is not an absolute necessity, but highly recommended. Basically,
> functions which can fail and propagate error codes need their error
> codes propagated. See the original commit:
> 1d4af04adf99301e21d7364d72f5570f5219083a for its rationale. It already
> has caught quite a few bugs (some of them CIDs), with no introduction
> of false positives yet. As long as one judiciously applies it (and not
> just everywhere), it should be very helpful.
>
> Note that it not only helps FFmpeg, but also users of FFmpeg who use
> our headers: if they do not check the return codes from our API's,
> they will get warnings. By the way, currently it is for GCC, etc -
> maybe there is an equivalent for MSVC etc that someone may add in the
> future (I personally don't care).
>
> I looked at the OpenCL stuff - seems to me like OpenCL can error out
> on this stuff, and the FFmpeg code here does return associated
> AVERROR's. These need to be propagated to whoever uses the API.

To anyone with opencl, ping.

>
>>
>> Thanks
>> Best regards
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