convince gcc that cpu_used et al are always initialized

convince gcc that cpu_used et al are always initialized

Without this, gcc thinks that min_quantizer, max_quantizer and cpu_used
are used uninitialized and emits a warning which is promoted to an error.

BUG=455409
TBR=bbudge

Committed: https://crrev.com/2dc24b537c4fda93db4148c3f5d30bcaea5147d8
Cr-Commit-Position: refs/heads/master@{#342214}

[Mostyn Bramley-Moore, 2015-08-06 06:30:13]

mostynb@opera.com changed reviewers:
+ bbudge@chromium.org, lionel.g.landwerlin@intel.com

[Mostyn Bramley-Moore, 2015-08-06 06:31:21]

@bbudge: PTAL at this gcc fixup for https://codereview.chromium.org/1132833002.

Without this, gcc gives the following warnings which are promoted to errors:

In file included from ../../content/renderer/pepper/video_encoder_shim.cc:20:0:
../../third_party/libvpx/source/libvpx/vpx/vp8cx.h: In member function ‘void
content::VideoEncoderShim::EncoderImpl::Initialize(media::VideoPixelFormat,
const gfx::Size&, media::VideoCodecProfile, uint32)’:
../../third_party/libvpx/source/libvpx/vpx/vp8cx.h:678:262: error: ‘cpu_used’
may be used uninitialized in this function [-Werror=maybe-uninitialized]
 VPX_CTRL_USE_TYPE(VP8E_SET_CPUUSED,            int)
                                                                                
                                                                                
                                                                                
                   ^
../../content/renderer/pepper/video_encoder_shim.cc:161:41: note: ‘cpu_used’ was
declared here
   int32_t min_quantizer, max_quantizer, cpu_used;
                                         ^
../../content/renderer/pepper/video_encoder_shim.cc:181:43: error:
‘max_quantizer’ may be used uninitialized in this function
[-Werror=maybe-uninitialized]
   config_.rc_max_quantizer = max_quantizer;
                                           ^
../../content/renderer/pepper/video_encoder_shim.cc:180:43: error:
‘min_quantizer’ may be used uninitialized in this function
[-Werror=maybe-uninitialized]
   config_.rc_min_quantizer = min_quantizer;
                                           ^
cc1plus: all warnings being treated as errors

[llandwerlin-old, 2015-08-06 09:57:14]

Looks good to me, but I'm not an owner.
Out of curiousity, is it with gcc 5?

Thanks!

On 2015/08/06 06:31:21, Mostyn Bramley-Moore wrote:
> @bbudge: PTAL at this gcc fixup for
https://codereview.chromium.org/1132833002.
> 
> Without this, gcc gives the following warnings which are promoted to errors:
> 
> In file included from
../../content/renderer/pepper/video_encoder_shim.cc:20:0:
> ../../third_party/libvpx/source/libvpx/vpx/vp8cx.h: In member function ‘void
> content::VideoEncoderShim::EncoderImpl::Initialize(media::VideoPixelFormat,
> const gfx::Size&, media::VideoCodecProfile, uint32)’:
> ../../third_party/libvpx/source/libvpx/vpx/vp8cx.h:678:262: error: ‘cpu_used’
> may be used uninitialized in this function [-Werror=maybe-uninitialized]
>  VPX_CTRL_USE_TYPE(VP8E_SET_CPUUSED,            int)
>                                                                               
 
>                                                                               
 
>                                                                               
 
>                    ^
> ../../content/renderer/pepper/video_encoder_shim.cc:161:41: note: ‘cpu_used’
was
> declared here
>    int32_t min_quantizer, max_quantizer, cpu_used;
>                                          ^
> ../../content/renderer/pepper/video_encoder_shim.cc:181:43: error:
> ‘max_quantizer’ may be used uninitialized in this function
> [-Werror=maybe-uninitialized]
>    config_.rc_max_quantizer = max_quantizer;
>                                            ^
> ../../content/renderer/pepper/video_encoder_shim.cc:180:43: error:
> ‘min_quantizer’ may be used uninitialized in this function
> [-Werror=maybe-uninitialized]
>    config_.rc_min_quantizer = min_quantizer;
>                                            ^
> cc1plus: all warnings being treated as errors

[Mostyn Bramley-Moore, 2015-08-06 10:02:16]

On 2015/08/06 09:57:14, llandwerlin wrote:
> Looks good to me, but I'm not an owner.
> Out of curiousity, is it with gcc 5?

I'm using gcc 4.8.4.

[Mostyn Bramley-Moore, 2015-08-06 11:59:51]

The CQ bit was checked by mostynb@opera.com to run a CQ dry run

[commit-bot: I haz the power, 2015-08-06 11:59:58]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1276633004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1276633004/1

[bbudge-google, 2015-08-06 12:26:25]

bbudge@google.com changed reviewers:
+ bbudge@google.com

[bbudge-google, 2015-08-06 12:26:26]

lgtm w/comment

https://codereview.chromium.org/1276633004/diff/1/content/renderer/pepper/vid...
File content/renderer/pepper/video_encoder_shim.cc (right):

https://codereview.chromium.org/1276633004/diff/1/content/renderer/pepper/vid...
content/renderer/pepper/video_encoder_shim.cc:82: *cpu_used =
kVp9DefaultCpuUsed;
nit: Just zero them to make it clear this is an error case.

[Mostyn Bramley-Moore, 2015-08-06 12:30:04]

On 2015/08/06 12:26:26, bbudge-google wrote:
> nit: Just zero them to make it clear this is an error case.

Done- thanks.

[Mostyn Bramley-Moore, 2015-08-06 12:30:06]

The CQ bit was checked by mostynb@opera.com

[Mostyn Bramley-Moore, 2015-08-06 12:30:07]

The patchset sent to the CQ was uploaded after l-g-t-m from bbudge@google.com
Link to the patchset: https://codereview.chromium.org/1276633004/#ps20001
(title: "just zero values")

[commit-bot: I haz the power, 2015-08-06 12:30:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1276633004/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1276633004/20001

[commit-bot: I haz the power, 2015-08-06 12:38:26]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-06 12:38:26]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[Mostyn Bramley-Moore, 2015-08-06 12:40:31]

The CQ bit was checked by mostynb@opera.com

[commit-bot: I haz the power, 2015-08-06 12:40:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1276633004/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1276633004/20001

[commit-bot: I haz the power, 2015-08-06 13:34:10]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-06 13:34:11]

Try jobs failed on following builders:
  win_chromium_x64_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Mostyn Bramley-Moore, 2015-08-06 21:40:29]

The CQ bit was checked by mostynb@opera.com

[commit-bot: I haz the power, 2015-08-06 21:42:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1276633004/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1276633004/20001

[commit-bot: I haz the power, 2015-08-06 22:24:33]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-08-06 22:25:23]

Patchset 2 (id:??) landed as
https://crrev.com/2dc24b537c4fda93db4148c3f5d30bcaea5147d8
Cr-Commit-Position: refs/heads/master@{#342214}