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Re: [PATCH] Fix UB in dbxout.c (PR debug/84637)
- From: Jeff Law <law at redhat dot com>
- To: Jakub Jelinek <jakub at redhat dot com>, Jim Wilson <wilson at tuliptree dot org>, Richard Biener <rguenther at suse dot de>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Wed, 18 Apr 2018 10:58:54 -0600
- Subject: Re: [PATCH] Fix UB in dbxout.c (PR debug/84637)
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On 04/17/2018 02:54 PM, Jakub Jelinek wrote:
> Hi!
>
> The first hunk is I think rather obvious, -2147483648 should be printed
> as -2147483648 and doesn't need to introduce UB in the compiler while doing
> so. The changes to stabstr_D are analogous, but in addition to that I don't
> see why we should just strip away the upper bits, it is again just a string
> containing decimal digits. What that function implemented is that
> values from -4294967295 to 4294967295 were printed as expected and the rest
> had some bits lost and HOST_WIDE_INT signed minimum invoked UB.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>
> 2018-04-17 Jakub Jelinek <jakub@redhat.com>
>
> PR debug/84637
> * dbxout.c (dbxout_int): Perform negation in unsigned int type.
> (stabstr_D): Change type of unum from unsigned int to
> unsigned HOST_WIDE_INT. Perform negation in unsigned HOST_WIDE_INT
> type.
OK.
jeff