Message 163353 - Python tracker

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In-reply-to
Author	mark.dickinson
Recipients	mark.dickinson, meador.inge
Date	2012年06月21日.17:30:02
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1340299804.63.0.65303748456.issue15119@psf.upfronthosting.co.za>

Content
There are two separate issues here. The first is that the layout that ctypes chooses for a struct of bitfields fails basic sanity checks, like having each bitfield actually fit in the corresponding type. As a result, the C-level bitshifting code used to get bitfields ends up invoking undefined behaviour. A secondary problem is that the ctypes layout doesn't match what the compiler does, at least for the system supplied gcc (4.2) on OS X 10.6. The attached patch fixes the first issue, but not the second.

Content

There are two separate issues here. The first is that the layout that ctypes chooses for a struct of bitfields fails basic sanity checks, like having each bitfield actually fit in the corresponding type. As a result, the C-level bitshifting code used to get bitfields ends up invoking undefined behaviour.
A secondary problem is that the ctypes layout doesn't match what the compiler does, at least for the system supplied gcc (4.2) on OS X 10.6.
The attached patch fixes the first issue, but not the second.

History
Date	User	Action	Args
2012年06月21日 17:30:05	mark.dickinson	set	recipients: + mark.dickinson, meador.inge
2012年06月21日 17:30:04	mark.dickinson	set	messageid: <1340299804.63.0.65303748456.issue15119@psf.upfronthosting.co.za>
2012年06月21日 17:30:03	mark.dickinson	link	issue15119 messages
2012年06月21日 17:30:03	mark.dickinson	create

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