gecko-dev/uriloader/exthandler/mac
Nicholas Nethercote 34dcc7b852 Bug 1299384 - Use MOZ_MUST_USE with NS_warn_if_impl(). r=erahm.
This change avoids lots of false positives for Coverity's CHECKED_RETURN
warning, caused by NS_WARN_IF's current use in both statement-style and
expression-style.

In the case where the code within the NS_WARN_IF has side-effects, I made the
following change.

> NS_WARN_IF(NS_FAILED(FunctionWithSideEffects()));
> -->
> Unused << NS_WARN_IF(NS_FAILED(FunctionWithSideEffects()));

In the case where the code within the NS_WARN_IF lacks side-effects, I made the
following change.

> NS_WARN_IF(!condWithoutSideEffects);
> -->
> NS_WARNING_ASSERTION(condWithoutSideEffects, "msg");

This has two improvements.
- The condition is not evaluated in non-debug builds.
- The sense of the condition is inverted to the familiar "this condition should
  be true" sense used in assertions.

A common variation on the side-effect-free case is the following.

> nsresult rv = Fn();
> NS_WARN_IF_(NS_FAILED(rv));
> -->
> DebugOnly<nsresult rv> = Fn();
> NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "Fn failed");

--HG--
extra : rebase_source : 58788245021096efa8372a9dc1d597a611d45611
2016-09-02 17:12:24 +10:00
..
nsDecodeAppleFile.cpp
nsDecodeAppleFile.h Bug 1293212 - Add MOZ_MUST_USE to prevent potential bugs. r=smaug 2016-08-08 18:16:15 +08:00
nsLocalHandlerAppMac.h
nsLocalHandlerAppMac.mm
nsMIMEInfoMac.h Bug 1293212 - Add MOZ_MUST_USE to prevent potential bugs. r=smaug 2016-08-08 18:16:15 +08:00
nsMIMEInfoMac.mm
nsOSHelperAppService.h Bug 1293212 - Add MOZ_MUST_USE to prevent potential bugs. r=smaug 2016-08-08 18:16:15 +08:00
nsOSHelperAppService.mm Bug 1299384 - Use MOZ_MUST_USE with NS_warn_if_impl(). r=erahm. 2016-09-02 17:12:24 +10:00