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From: Martin Sebor <msebor@gmail.com>
To: Jeff Law <jeffreyalaw@gmail.com>, gcc-patches <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] correct uninitialized object offset and size computation [PR101494]
Date: Wed, 28 Jul 2021 16:28:38 -0600	[thread overview]
Message-ID: <14ea6066-7451-9f35-fa00-8305ff94fc8c@gmail.com> (raw)
In-Reply-To: <40bca91d-bf71-74c7-0209-5322c45a5278@gmail.com>

On 7/23/21 10:39 AM, Jeff Law wrote:
> 
> 
> On 7/22/2021 3:58 PM, Martin Sebor via Gcc-patches wrote:
>> The code that computes the size of an access to an object in
>> -Wuninitialized is limited to declared objects and so doesn't
>> apply to allocated objects, and doesn't correctly account for
>> an offset into the object and the access size.  This causes
>> false positives.
>>
>> The attached fix tested on x86_64-linux corrects this.
>>
>> Martin
>>
>> gcc-101494.diff
>>
>> Correct uninitialized object offset and size computation [PR101494].
>>
>> Resolves:
>> PR middle-end/101494 - -uninitialized false alarm with memrchr of size 0
>>
>> gcc/ChangeLog:
>>
>> 	PR middle-end/101494
>> 	* tree-ssa-uninit.c (builtin_call_nomodifying_p):
>> 	(check_defs):
>> 	(maybe_warn_operand):
>>
>> gcc/testsuite/ChangeLog:
>>
>> 	PR middle-end/101494
>> 	* gcc.dg/uninit-38.c:
>> 	* gcc.dg/uninit-41.c: New test.
>> 	* gcc.dg/uninit-pr101494.c: New test.
> OK once you complete the ChangeLog entry for the tree-ssa-uninit.c 
> change.  Note this change only modifies maybe_warn_operand.

Whoops.  Fixed and pushed in r12-2583.

Martin

      reply	other threads:[~2021-07-28 22:28 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-22 21:58 Martin Sebor
2021-07-23 16:39 ` Jeff Law
2021-07-28 22:28   ` Martin Sebor [this message]

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