disable C4125 on windows

disable C4125 on windows

warning C4125: decimal digit terminates octal escape sequence

Proto compiler generated code causes lots of warnings on windows.
Example: https://codereview.chromium.org/2743323004

BUG=

Review-Url: https://codereview.chromium.org/2746363004
Cr-Commit-Position: refs/heads/master@{#457237}
Committed: https://chromium.googlesource.com/chromium/src/+/231cffae9f80aa63ef0d77ac2775b0a2268978a4

[aizatsky, 2017-03-15 19:02:56]

aizatsky@chromium.org changed reviewers:
+ pkasting@chromium.org, vitalybuka@chromium.org, xyzzyz@chromium.org

[Vitaly Buka (NO REVIEWS), 2017-03-15 20:08:48]

lgtm

[Peter Kasting, 2017-03-15 20:11:27]

Can we just fix protoc to not do this?

[aizatsky, 2017-03-15 20:15:20]

On 2017/03/15 at 20:11:27, pkasting wrote:
> Can we just fix protoc to not do this?

Maybe, but both proto2 & proto3 generate such code. I'm afraid that is a much
bigger issue overall.

[aizatsky, 2017-03-15 20:16:34]

On 2017/03/15 at 20:15:20, aizatsky wrote:
> On 2017/03/15 at 20:11:27, pkasting wrote:
> > Can we just fix protoc to not do this?
> 
> Maybe, but both proto2 & proto3 generate such code. I'm afraid that is a much
bigger issue overall.

To be more specific, the code in question is descriptor data:

"\001(\0132\004.Tag\"\247\t\n\003Tag\022\027\n\004name\030\001
\001(\0162\t.Tag.Na"                                                            
     
It complains about construct "\0162"


Given that this warning isn't triggered on gcc, I think disabling it on this
file is the easiest thing to do.

[Peter Kasting, 2017-03-15 20:23:37]

LGTM

https://codereview.chromium.org/2746363004/diff/1/third_party/protobuf/proto_...
File third_party/protobuf/proto_library.gni (right):

https://codereview.chromium.org/2746363004/diff/1/third_party/protobuf/proto_...
third_party/protobuf/proto_library.gni:379: # disable: C4125 decimal digit
terminates octal escape sequence
Nit: I suggest adding:

protoc generates such sequences frequently, there's not an obviously superior
replacement behavior, and since this code is autogenerated, the warning will
never catch a legitimate bug.

[aizatsky, 2017-03-15 20:32:28]

The CQ bit was checked by aizatsky@chromium.org

[aizatsky, 2017-03-15 20:32:29]

Thanks for quick workaround. Submitting.

https://codereview.chromium.org/2746363004/diff/1/third_party/protobuf/proto_...
File third_party/protobuf/proto_library.gni (right):

https://codereview.chromium.org/2746363004/diff/1/third_party/protobuf/proto_...
third_party/protobuf/proto_library.gni:379: # disable: C4125 decimal digit
terminates octal escape sequence
On 2017/03/15 at 20:23:37, Peter Kasting wrote:
> Nit: I suggest adding:
> 
> protoc generates such sequences frequently, there's not an obviously superior
replacement behavior, and since this code is autogenerated, the warning will
never catch a legitimate bug.

done.

[aizatsky, 2017-03-15 20:32:29]

The patchset sent to the CQ was uploaded after l-g-t-m from
pkasting@chromium.org, vitalybuka@chromium.org
Link to the patchset: https://codereview.chromium.org/2746363004/#ps20001
(title: "explanatory comment")

[commit-bot: I haz the power, 2017-03-15 20:33:20]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-15 22:28:42]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1489609948554990,
"parent_rev": "65d49b1f6f6d9329554c1b891c0d98e6644d5191", "commit_rev":
"231cffae9f80aa63ef0d77ac2775b0a2268978a4"}

[commit-bot: I haz the power, 2017-03-15 22:29:30]

Description was changed from

==========
disable C4125 on windows

warning C4125: decimal digit terminates octal escape sequence

Proto compiler generated code causes lots of warnings on windows.
Example: https://codereview.chromium.org/2743323004

BUG=
==========

to

==========
disable C4125 on windows

warning C4125: decimal digit terminates octal escape sequence

Proto compiler generated code causes lots of warnings on windows.
Example: https://codereview.chromium.org/2743323004

BUG=

Review-Url: https://codereview.chromium.org/2746363004
Cr-Commit-Position: refs/heads/master@{#457237}
Committed:
https://chromium.googlesource.com/chromium/src/+/231cffae9f80aa63ef0d77ac2775...
==========

[commit-bot: I haz the power, 2017-03-15 22:29:31]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/231cffae9f80aa63ef0d77ac2775...