Bug 43619 – Bitmap.h has no default constructor

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Zoltan Herczeg]

The bitmap array is not cleared, and contains a memory garbage after init.

[Zoltan Herczeg]

Created attachment 63718 [details]
patch

[Geoffrey Garen]

Comment on attachment 63718 [details]
patch

Nice catch.

JavaScriptCore/wtf/Bitmap.h:35
 +      Bitmap(bool initializationNeeded = true);
WebKit is moving toward a policy of considering boolean arguments to functions to be a bad design pattern. I think we may eventually discourage or forbid them in our coding style guidelines. The problem with this kind of argument is that it's very hard to tell, at the callsite, exactly what "true" or "false" might mean.

I think you should just remove the boolean argument here.

If we do want to take advantage of an optimized "no initialization" bitmap in the future, let's add an extra constructor akin to the AdoptCFTag constructor for RetainPtr, or the VPtrStealingHackType constructor for JSString.

Otherwise, this patch is great!

[Zoltan Herczeg]

Created attachment 63748 [details]
patch v2

[Eric Seidel (no email)]

Comment on attachment 63748 [details]
patch v2

LGTM.

[Zoltan Herczeg]

Landed in http://trac.webkit.org/changeset/64912
Closing bug.

[Yael]

This is the fix I was about to suggest for https://qtrequirements.europe.nokia.com/browse/BR-4872, just to find that it was already fixed. :-(

[Ademar Reis]

Revision r64912 cherry-picked into qtwebkit-2.1 with commit 67daffa <http://gitorious.org/webkit/qtwebkit/commit/67daffa>