With clang -fsanitize=enum, I see the following runtime errors in automated testing on linux64-asan. Seems to be caused by loading of stagefright_MPEG4Metadata.test_case_mp4: dom/media/MediaInfo.cpp:14:11 1 load of value 4294967295, which is not a valid value for type 'TrackInfo::TrackType' media/libstagefright/binding/MP4Metadata.cpp:278:35 1 load of value 4294967295, which is not a valid value for type 'mozill a::TrackInfo::TrackType' media/libstagefright/binding/MP4Metadata.cpp:281:28 1 load of value 4294967295, which is not a valid value for type 'mozill a::TrackInfo::TrackType' media/libstagefright/binding/MP4Metadata.cpp:296:7 1 load of value 4294967295, which is not a valid value for type 'mozill a::TrackInfo::TrackType' media/libstagefright/binding/MP4Metadata.cpp:300:14 1 load of value 4294967295, which is not a valid value for type 'mozill a::TrackInfo::TrackType' media/libstagefright/binding/MP4Metadata.cpp:371:32 1 load of value 4294967295, which is not a valid value for type 'mozill a::TrackInfo::TrackType' media/libstagefright/binding/MP4Metadata.cpp:374:25 1 load of value 4294967295, which is not a valid value for type 'mozill a::TrackInfo::TrackType' media/libstagefright/binding/MP4Metadata.cpp:517:13 1 load of value 4294967295, which is not a valid value for type 'mozill a::TrackInfo::TrackType' media/libstagefright/binding/MP4Metadata.cpp:544:25 1 load of value 4294967295, which is not a valid value for type 'mozill a::TrackInfo::TrackType' media/libstagefright/binding/MP4Metadata.cpp:559:13 1 load of value 4294967295, which is not a valid value for type 'mozill a::TrackInfo::TrackType' media/libstagefright/binding/MP4Metadata.cpp:582:25 1 load of value 4294967295, which is not a valid value for type 'mozill a::TrackInfo::TrackType' media/libstagefright/binding/MP4Metadata.cpp:800:11 1 load of value 4294967295, which is not a valid value for type 'TrackI nfo::TrackType' media/libstagefright/binding/MP4Metadata.cpp:834:24 1 load of value 4294967295, which is not a valid value for type 'mozill a::TrackInfo::TrackType'

Hi Gerald, I'm proposing removing these lines because I'm planning to add -fsanitize=enum in the debug build, and it disallows values outside the enum range. (See bug 1404547.) So those tests will be superfluous.

Comment on attachment 8914833 [details] [diff] [review] 0001-Bug-1405139-Fix-ubsan-runtime-error-for-TrackInfo-Tr.patch Review of attachment 8914833 [details] [diff] [review]: ----------------------------------------------------------------- I think at the time I may have been worried that these calls could be made with a TrackType coming from the (externally-sourced) media itself, and therefore could potentially be unexpected values. But in fact, in all instances I can see, this TrackType is explicitly specified as one of the enum constants in our code. So it should be safe not to worry about handling non-compliant enum values, as they should never happen; and these tests are indeed not necessary. Thank you for submitting this patch.

Thanks for the review!

Pushed by ryanvm@gmail.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/6783b6208ea6 Fix ubsan runtime error for TrackInfo::TrackType. r=gerald