1552363 - [Automated review] Non-static class member field "span.last" is not initialized in this constructor nor in any functions that it calls

Status: RESOLVED FIXED

(Developer Infrastructure :: Source Code Analysis, defect)

Description

[Steve Fink [:sfink] [:s:]]

https://phabricator.services.mozilla.com/D30103?id=105050#inline-185350

This is incorrect. The constructor calls init(), which calls reset(), which assigns the whole 'span' field by copying from another FreeSpan object.

I guess it could be claiming that the firstFreeSpan doesn't always initialize its .last field? I don't know how far it chases through data flow.

Comment 1

[Andi [:andi]]

I see init() being called only in the explicit ctor but in the default one we only set some member variables but we don't set span.

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

The priority flag is not set for this bug.
:sylvestre, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 3

[Andi [:andi]]

Steve what d you think about what I said in my previous message, do you think we should fix this by also initializing span in the default ctor? Otherwise I think we should close this bug.

Comment 4

[Steve Fink [:sfink] [:s:]]

Attachment: Bug 1552363 - Initialize FreeSpan in default constructor

Comment 5

[Steve Fink [:sfink] [:s:]]

Sorry, you are correct, this was a real bug. I don't think it mattered in practice, because init() would always end up getting called, but the analysis is absolutely correct that this produces an opportunity to use the class in a way that would use uninitialized memory.

Thanks!

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/cb6ec14a123a
Initialize FreeSpan in default constructor r=jonco

Comment 7

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/cb6ec14a123a