Hi, As :njn announced before [1], we are trying to add MOZ_MUST_USE to all fail-able functions, which is tracking in bug 1268766 [2].
We have bugs to track the progress for each directory. If anyone is interested, please feel free to take any of the bugs. We hope all reviewers also mind the following rules, so that new code may benefit by the static checking. I'll update the style guide to reflect these rules later. The attribute is meant to avoid possible fatal failure. All failure should be handled, reported, asserted, or at least caught by Unused (and better leave a comment, see bug 1301574 [3]). You can find the rule proposed by :njn in the bug comment [4]. Because now we don't need to worry about NS_IMETHOD (see bug 1295825 [5]), we have updated rules: 1. search all *.h and *.idl 2. add [must_use] for *.idl 3. add MOZ_MUST_USE for all functions that return |nsresult| or |bool| in *.h Also with some exceptions: 1. Predicates, getters which return |bool|. 2. IPC method implementation (e.g. bool RecvSomeMessage()). 3. Most callers just check the output parameter. e.g.: nsresult SomeMap::GetValue(const nsString& key, nsString& value); nsString value; rv = map->GetValue(key, value); If it failed, of course |value| will be empty. But if it succeed, |value| may still be empty because the stored value is empty in the first place. So just check |value| is a common idiom. This was also discussed in thread [1], and seems we still have no conclusion. Such grey zone will depend on each reviewers' own judgement. Wei-Cheng Pan [1] https://groups.google.com/forum/#!msg/mozilla.dev.platform/dS5Dz6SfO3w/avzIxb7CBAAJ [2] https://bugzilla.mozilla.org/show_bug.cgi?id=MOZ_MUST_USE [3] https://bugzilla.mozilla.org/show_bug.cgi?id=1301574 [4] https://bugzilla.mozilla.org/show_bug.cgi?id=1268766#c5 [5] https://bugzilla.mozilla.org/show_bug.cgi?id=1295825 _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
