Patchwork Get rid of Werror=maybe-uninitialized in res_send.c.

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Submitter Stefan Liebler
Date Dec. 3, 2019, 8:50 a.m.
Message ID <03d65724-d69b-d553-18a5-dece072e5a45@linux.ibm.com>
Download mbox | patch
Permalink /patch/36457/
State Committed
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Comments

Stefan Liebler - Dec. 3, 2019, 8:50 a.m.
Hi,

the commit 446997ff1433d33452b81dfa9e626b8dccf101a4 introduced
this new usage of resplen. If build with gcc 9 -march>=z13 on s390x,
the following warning occurs:
res_send.c: In function ‘__res_context_send’:
res_send.c:539:6: error: ‘resplen’ may be used uninitialized in this 
function [-Werror=maybe-uninitialized]
539 |   if (resplen > HFIXEDSZ)
|      ^

Therefore this patch adds a further DIAG_IGNORE_NEEDS_COMMENT in the
same way as it was previously done for usages of resplen or n.
See commit d1bc2cbbed9aea2017ef941f63c8786571da5b4f.

Bye
Stefan
Stefan Liebler - Dec. 9, 2019, 1 p.m.
On 12/3/19 9:50 AM, Stefan Liebler wrote:
> Hi,
> 
> the commit 446997ff1433d33452b81dfa9e626b8dccf101a4 introduced
> this new usage of resplen. If build with gcc 9 -march>=z13 on s390x,
> the following warning occurs:
> res_send.c: In function ‘__res_context_send’:
> res_send.c:539:6: error: ‘resplen’ may be used uninitialized in this 
> function [-Werror=maybe-uninitialized]
> 539 |   if (resplen > HFIXEDSZ)
> |      ^
> 
> Therefore this patch adds a further DIAG_IGNORE_NEEDS_COMMENT in the
> same way as it was previously done for usages of resplen or n.
> See commit d1bc2cbbed9aea2017ef941f63c8786571da5b4f.
> 
> Bye
> Stefan

ping
Stefan Liebler - Dec. 13, 2019, 12:43 p.m.
On 12/9/19 2:00 PM, Stefan Liebler wrote:
> On 12/3/19 9:50 AM, Stefan Liebler wrote:
>> Hi,
>>
>> the commit 446997ff1433d33452b81dfa9e626b8dccf101a4 introduced
>> this new usage of resplen. If build with gcc 9 -march>=z13 on s390x,
>> the following warning occurs:
>> res_send.c: In function ‘__res_context_send’:
>> res_send.c:539:6: error: ‘resplen’ may be used uninitialized in this 
>> function [-Werror=maybe-uninitialized]
>> 539 |   if (resplen > HFIXEDSZ)
>> |      ^
>>
>> Therefore this patch adds a further DIAG_IGNORE_NEEDS_COMMENT in the
>> same way as it was previously done for usages of resplen or n.
>> See commit d1bc2cbbed9aea2017ef941f63c8786571da5b4f.
>>
>> Bye
>> Stefan
> 
> ping
> 
ping
Stefan Liebler - Jan. 8, 2020, 7:47 a.m.
On 12/13/19 1:43 PM, Stefan Liebler wrote:
> On 12/9/19 2:00 PM, Stefan Liebler wrote:
>> On 12/3/19 9:50 AM, Stefan Liebler wrote:
>>> Hi,
>>>
>>> the commit 446997ff1433d33452b81dfa9e626b8dccf101a4 introduced
>>> this new usage of resplen. If build with gcc 9 -march>=z13 on s390x,
>>> the following warning occurs:
>>> res_send.c: In function ‘__res_context_send’:
>>> res_send.c:539:6: error: ‘resplen’ may be used uninitialized in this 
>>> function [-Werror=maybe-uninitialized]
>>> 539 |   if (resplen > HFIXEDSZ)
>>> |      ^
>>>
>>> Therefore this patch adds a further DIAG_IGNORE_NEEDS_COMMENT in the
>>> same way as it was previously done for usages of resplen or n.
>>> See commit d1bc2cbbed9aea2017ef941f63c8786571da5b4f.
>>>
>>> Bye
>>> Stefan
>>
>> ping
>>
> ping
> 
ping
Stefan Liebler - Jan. 14, 2020, 8:22 a.m.
On 1/8/20 8:47 AM, Stefan Liebler wrote:
> On 12/13/19 1:43 PM, Stefan Liebler wrote:
>> On 12/9/19 2:00 PM, Stefan Liebler wrote:
>>> On 12/3/19 9:50 AM, Stefan Liebler wrote:
>>>> Hi,
>>>>
>>>> the commit 446997ff1433d33452b81dfa9e626b8dccf101a4 introduced
>>>> this new usage of resplen. If build with gcc 9 -march>=z13 on s390x,
>>>> the following warning occurs:
>>>> res_send.c: In function ‘__res_context_send’:
>>>> res_send.c:539:6: error: ‘resplen’ may be used uninitialized in this 
>>>> function [-Werror=maybe-uninitialized]
>>>> 539 |   if (resplen > HFIXEDSZ)
>>>> |      ^
>>>>
>>>> Therefore this patch adds a further DIAG_IGNORE_NEEDS_COMMENT in the
>>>> same way as it was previously done for usages of resplen or n.
>>>> See commit d1bc2cbbed9aea2017ef941f63c8786571da5b4f.
>>>>
>>>> Bye
>>>> Stefan
>>>
>>> ping
>>>
>> ping
>>
> ping
> 
ping
Stefan Liebler - Jan. 20, 2020, 8:17 a.m.
On 1/14/20 9:22 AM, Stefan Liebler wrote:
> On 1/8/20 8:47 AM, Stefan Liebler wrote:
>> On 12/13/19 1:43 PM, Stefan Liebler wrote:
>>> On 12/9/19 2:00 PM, Stefan Liebler wrote:
>>>> On 12/3/19 9:50 AM, Stefan Liebler wrote:
>>>>> Hi,
>>>>>
>>>>> the commit 446997ff1433d33452b81dfa9e626b8dccf101a4 introduced
>>>>> this new usage of resplen. If build with gcc 9 -march>=z13 on s390x,
>>>>> the following warning occurs:
>>>>> res_send.c: In function ‘__res_context_send’:
>>>>> res_send.c:539:6: error: ‘resplen’ may be used uninitialized in 
>>>>> this function [-Werror=maybe-uninitialized]
>>>>> 539 |   if (resplen > HFIXEDSZ)
>>>>> |      ^
>>>>>
>>>>> Therefore this patch adds a further DIAG_IGNORE_NEEDS_COMMENT in the
>>>>> same way as it was previously done for usages of resplen or n.
>>>>> See commit d1bc2cbbed9aea2017ef941f63c8786571da5b4f.
>>>>>
>>>>> Bye
>>>>> Stefan
>>>>
>>>> ping
>>>>
>>> ping
>>>
>> ping
>>
> ping
> 
ping
Siddhesh Poyarekar - Jan. 20, 2020, 8:27 a.m.
On 03/12/19 2:20 pm, Stefan Liebler wrote:
> Hi,
> 
> the commit 446997ff1433d33452b81dfa9e626b8dccf101a4 introduced
> this new usage of resplen. If build with gcc 9 -march>=z13 on s390x,
> the following warning occurs:
> res_send.c: In function ‘__res_context_send’:
> res_send.c:539:6: error: ‘resplen’ may be used uninitialized in this
> function [-Werror=maybe-uninitialized]
> 539 |   if (resplen > HFIXEDSZ)
> |      ^
> 
> Therefore this patch adds a further DIAG_IGNORE_NEEDS_COMMENT in the
> same way as it was previously done for usages of resplen or n.
> See commit d1bc2cbbed9aea2017ef941f63c8786571da5b4f.

This is fine.  OK to commit to master.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

PS: Please send patches inline (using git send-email) since it's easier
to add review comments that way.
Stefan Liebler - Jan. 20, 2020, 10:02 a.m.
On 1/20/20 9:27 AM, Siddhesh Poyarekar wrote:
> On 03/12/19 2:20 pm, Stefan Liebler wrote:
>> Hi,
>>
>> the commit 446997ff1433d33452b81dfa9e626b8dccf101a4 introduced
>> this new usage of resplen. If build with gcc 9 -march>=z13 on s390x,
>> the following warning occurs:
>> res_send.c: In function ‘__res_context_send’:
>> res_send.c:539:6: error: ‘resplen’ may be used uninitialized in this
>> function [-Werror=maybe-uninitialized]
>> 539 |   if (resplen > HFIXEDSZ)
>> |      ^
>>
>> Therefore this patch adds a further DIAG_IGNORE_NEEDS_COMMENT in the
>> same way as it was previously done for usages of resplen or n.
>> See commit d1bc2cbbed9aea2017ef941f63c8786571da5b4f.
> 
> This is fine.  OK to commit to master.
> 
> Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
> 
> PS: Please send patches inline (using git send-email) since it's easier
> to add review comments that way.
> 

Okay.

Committed.

Thanks.
Stefan

Patch

commit bfd6a9fcd4fbbd19eb67b868a27f83c801e2e725
Author: Stefan Liebler <stli@linux.ibm.com>
Date:   Mon Dec 2 13:11:52 2019 +0100

    Get rid of Werror=maybe-uninitialized in res_send.c.
    
    The commit 446997ff1433d33452b81dfa9e626b8dccf101a4 introduced
    this new usage of resplen. If build with gcc 9 -march>=z13 on s390x,
    the following warning occurs:
    res_send.c: In function ‘__res_context_send’:
    res_send.c:539:6: error: ‘resplen’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
      539 |   if (resplen > HFIXEDSZ)
          |      ^
    
    Therefore this patch adds a further DIAG_IGNORE_NEEDS_COMMENT in the
    same way as it was previously done for usages of resplen or n.
    See commit d1bc2cbbed9aea2017ef941f63c8786571da5b4f.

diff --git a/resolv/res_send.c b/resolv/res_send.c
index fce810031f..975985f13a 100644
--- a/resolv/res_send.c
+++ b/resolv/res_send.c
@@ -534,6 +534,9 @@  __res_context_send (struct resolv_context *ctx,
 
 		resplen = n;
 
+		/* See comment at the declaration of n.  Note: resplen = n;  */
+		DIAG_PUSH_NEEDS_COMMENT;
+		DIAG_IGNORE_NEEDS_COMMENT (9, "-Wmaybe-uninitialized");
 		/* Mask the AD bit in both responses unless it is
 		   marked trusted.  */
 		if (resplen > HFIXEDSZ)
@@ -543,6 +546,7 @@  __res_context_send (struct resolv_context *ctx,
 		    else
 		      mask_ad_bit (ctx, ans);
 		  }
+		DIAG_POP_NEEDS_COMMENT;
 		if (resplen2 != NULL && *resplen2 > HFIXEDSZ)
 		  mask_ad_bit (ctx, *ansp2);