805552 - g++ 4.7 opt builds w/ --enable-warnings-as-errors hit tons of error: variable ‘rv’ set but not used [-Werror=unused-but-set-variable] in /netwerk

Status: RESOLVED FIXED

(Core :: Networking, defect)

Description

[Daniel Holbert [:dholbert]]

Just tried to do an opt build w/ --enable-warnings-as-errors, and I hit a bunch of errors in /netwerk from nsresults whose values are set but not used (only checked in debug builds).

These need to be labeled as DebugOnly. Filing this bug on fixing 'em.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: fix v1

Comment 2

[Jason Duell]

Comment on attachment 675233 [details] [diff] [review]
fix v1

Review of attachment 675233 [details] [diff] [review]:
-----------------------------------------------------------------

::: netwerk/base/src/nsIOService.cpp
@@ -691,5 @@
>          }
>      }
>  
>      nsIIOService *subject = static_cast<nsIIOService *>(this);
> -    nsresult rv;

any reason not to just make keep this as a DebugOnly rv, instead of declaring 3 separate vars in different subscopes?  Not a big deal--either works.

Comment 3

[Daniel Holbert [:dholbert]]

Just for scoping purposes.

In each usage of "rv" in that function, the variable is set & then immediately checked, inside of a restricted "{...}" block, and that value is never used again.  So, no need to let the value leak outside of that scope.  (Plus, there's no perf impact to redeclaring it, since it's DebugOnly anyway.)

Comment 4

[Daniel Holbert [:dholbert]]

Thanks for the quick review turnaround!  Landed:
https://hg.mozilla.org/integration/mozilla-inbound/rev/3dc8241751a9

Comment 5

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/3dc8241751a9