444409 - outparam 'this' not written on NS_SUCCEEDED(return value)

Status: RESOLVED FIXED

(Developer Infrastructure :: Source Code Analysis, defect)

Description

[Benjamin Smedberg]

../../../dist/include/string/nsTSubstring.h: In member function ‘void nsAString_internal::SetDataFlags(PRUint32)’:
../../../dist/include/string/nsTSubstring.h:638: warning: outparam 'this' not written on NS_SUCCEEDED(return value)
../../../dist/include/string/nsTSubstring.h:634:   outparam declared here

Something's wrong with the outparam analysis... it's trying to analyze methods which are not supposed to be analyzed, I think. And it's claiming "this" as an outparam, which is even weirder.

Comment 1

[David Mandelin [:dmandelin]]

Attachment: Patch

Argh. Somehow it's always been harder to get right the semantics of the spec for what is an outparam than the high-tech analysis stuff. Anyway, I overhauled that part for the last update, and introduced a bug.

Part of the old bug was that OUTNOFAIL (outparam, function never fails to write it ever) stuff wasn't getting checked, which is bad when it's OUTNOFAIL because the function returns void, because void-returning functions should be checked. But I forgot that OUTNOFAIL was also used for 'this' in string mutators. This is correct when they are callees, but we don't want to analyze them (and the script doesn't analyze them correctly).

Comment 2

[David Mandelin [:dmandelin]]

Pushed.