1446583 - [WebRTC] Update location for setting trace-pc coverage flags for LibFuzzer

Status: RESOLVED FIXED

(Core :: WebRTC: Signaling, enhancement, P3)

Description

[Christoph Diehl [:posidron]]

Attachment: libfuzzer.coverage.flags.diff

Something must have changed recently in moz.build files which prevented the WebRTC LibFuzzer's in our tree from working correctly / from being covered.

Comment 1

[Nils Ohlmeier [:drno]]

Comment on attachment 8959751 [details] [diff] [review]
libfuzzer.coverage.flags.diff

Review of attachment 8959751 [details] [diff] [review]:
-----------------------------------------------------------------

LGTM

Comment 2

[Christian Holler (:decoder)]

This patch doesn't look right to me. You need the instrumentation flags in every moz.build file that is used to build the target source code, not just those used to build the fuzzing entry point.

Comment 3

[Christian Holler (:decoder)]

For mtransport, you probably need it in media/mtransport/build/moz.build because that defines SOURCES.

The stuff in media/mtransport/third_party/ worries me because that seems to use GYP and while I see the flag here

https://searchfox.org/mozilla-central/rev/6e96a3f1e44e286ddae5fdafab737709741d237a/media/mtransport/third_party/nICEr/nicer.gyp#242

I'm not sure if this is working properly. You should probably make a verbose build and log all the output, then check that all of this third_party stuff is built properly with instrumentation.

For SDP, you need to add it also to media/webrtc/signaling/src/sdp/moz.build because again, that defines SOURCES to be built.

Comment 4

[Christoph Diehl [:posidron]]

Attachment: libfuzzer.coverage.flags.diff

Previously:

* Added flags to 'media/mtransport/fuzztest/moz.build'
* Added flags to 'media/webrtc/signaling/fuzztest/moz.build'

Additionally:

* Added flags to 'media/mtransport/build/moz.build'
* Added flags to 'media/webrtc/signaling/src/sdp/moz.build'

* Added additionally '-fsanitize-coverage=trace-cmp' to:
- 'media/webrtc/signaling/fuzztest/moz.build'
- 'media/webrtc/signaling/src/sdp/moz.build'

* Undo the removal of the flags in:
- media/mtransport/moz.build
- media/webrtc/moz.build

* Verified that 'media/mtransport/third_party/' gets compiled with the provided flags.

Comment 5

[Nils Ohlmeier [:drno]]

Comment on attachment 8959842 [details] [diff] [review]
libfuzzer.coverage.flags.diff

LGTM

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/d5efd6828875
Update location for setting trace-pc coverage flags for LibFuzzer r=drno

Comment 7

[Arthur Iakab [arthur_iakab]]

https://hg.mozilla.org/mozilla-central/rev/d5efd6828875