`mach build` attempts to parse compiler warnings to a persisted "database." You can view a list of compiler warnings post build by running `mach warnings-list`. The intent behind this feature was to make it easier to find and fix compiler warnings. After all, something out of sight is out of mind.
There have been a few recent changes to increase the visibility of compiler warnings with the expectation being that raising visibility will increase the chances of someone addressing them. After all, a compiler warning is either a) valid and should be fixed or b) invalid and should be ignored. Either way, a compiler warning shouldn't exist. First, `mach build` now prints a list of all parsed compiler warnings at the end of the build. More details are in the commit message: https://hg.mozilla.org/mozilla-central/rev/4abe611696ab Second, Perfherder now records the compiler warning count as a metric. This means we now have alerts when compiler warnings are added or removed, like [1]. And, we can easily see graphs of compiler warnings over time, like [2]. The compiler warnings are also surfaced in the "performance" tab of build jobs on Treeherder, like [3]. The Perfherder alerts and tracking are informational only: nobody will be backing you out merely because you added a compiler warning. While the possibility of doing that now exists, I view that decision as up to the C++ module. I'm not going to advocate for it. So if you feel passionately, take it up with them :) Astute link clickers will note that the count metrics in CI are often noisy - commonly fluctuating by a value of 1-2. I suspect there are race conditions with interleaved process output and/or bugs in the compiler warnings parser/aggregator. Since the values are currently advisory only, I'm very much taking a "perfect is the enemy of good" attitude and have no plans to improve the robustness. [1] https://treeherder.mozilla.org/perf.html#/alerts?id=6700 [2] https://mzl.la/2qFN0me and https://mzl.la/2rAkWR5 [3] https://treeherder.mozilla.org/#/jobs?repo=autoland&selectedJob=100509284 _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
