[OE-core] [PATCH] mdadm: fix gcc8 maybe-uninitialized/format-overflow warning

[Changqing Li]

On 3/21/19 1:06 AM, Khem Raj wrote:
> On Wed, Mar 20, 2019 at 11:00 AM Adrian Bunk <bunk at stusta.de> wrote:
>> On Wed, Mar 20, 2019 at 08:59:39AM -0400, Khem Raj wrote:
>>> On Wed, Mar 20, 2019 at 1:21 AM Adrian Bunk <bunk at stusta.de> wrote:
>>>> On Tue, Mar 19, 2019 at 11:51:47PM -0400, Khem Raj wrote:
>>>>> On Fri, Mar 15, 2019 at 6:45 AM Adrian Bunk <bunk at stusta.de> wrote:
>>>>>> On Tue, Mar 12, 2019 at 05:41:58PM +0800, changqing.li at windriver.com wrote:
>>>>>>> From: Changqing Li <changqing.li at windriver.com>
>>>>>>>
>>>>>>> while compiled with -Werror=maybe-uninitialized/-Werror=format-overflow=,
>>>>>>> it failed
>>>>>>>
>>>>>>> [snip]
>>>>>>> | Incremental.c: In function 'Incremental_container':
>>>>>>> | Incremental.c:1593:3: error: 'mdfd' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>>>>>>> | close(mdfd);
>>>>>>> | ^~~~~~~~~~~
>>>>>>>
>>>>>>> [snip]
>>>>>>> super-intel.c: In function 'apply_takeover_update':
>>>>>>> | super-intel.c:9615:15: error: '%d' directive writing between 1 and 11 bytes into a region of size 7 [-Werror=format-overflow=]
>>>>>>> | " MISSING_%d", du->index);
>>>>>>> | ^~
>>>>>>> ...
>>>>>> I am seeing these warnings only with -Og, are you also seeing them with
>>>>>> -Og (DEBUG_OPTIMIZATION) only?
yes.
>>>>>>
>>>>>> If this is true, I would consider
>>>>>> https://sources.debian.org/src/mdadm/4.1-2/debian/patches/debian-no-Werror.diff/
>>>>>> a better workaround.
>>>>>>
>>>>> This seems a broader brush, I really dont like to relegate Werror if
>>>>> we dont have to, because it will force us
>>>>> to fix the code.
>>>> How are we getting such fixes properly reviewed?
>>>>
>>>> What actually happens is that the easiest change that silences a warning
>>>> gets applied.
>>>>
>>>> And for such bogus -Og only warnings there was no problem in the code,
>>> so then probably a better fix is to add -Wno-error to DEBUG_FLAGS
>>> which will limit it to -Og case, and revert the original fix.

Both DEBUG_OPTIMIZATION and FULL_OPTIMIZATION appended DEBUG_FLAGS.

in order limit it to -Og case,  I will add  -Wno-error to 
DEBUG_OPTIMIZATION, and send a v2.


[snip]

FULL_OPTIMIZATION = "-O2 -pipe ${DEBUG_FLAGS}"

DEBUG_OPTIMIZATION = "-Og ${DEBUG_FLAGS} -pipe"

SELECTED_OPTIMIZATION = "${@d.getVar(oe.utils.vartrue('DEBUG_BUILD', 
'DEBUG_OPTIMIZATION', 'FULL_OPTIMIZATION', d))}"




>> For mdadm this might work, for puzzles it would not.
>>
>> Order matters, and upstream can insert your flags before or after
>> the -Werror. So unfortunately this would not cover all recipes.
>>
> suggestion was not global, but just for this recipe. I still would
> suggest that we disable it only where needed
>
>> cu
>> Adrian
>>
>> --
>>
>>         "Is there not promise of rain?" Ling Tan asked suddenly out
>>          of the darkness. There had been need of rain for many days.
>>         "Only a promise," Lao Er said.
>>                                         Pearl S. Buck - Dragon Seed
>>
-- 
BRs

Sandy(Li Changqing)