Re: [PATCH 1/4] environ-selftests: Ignore -Wself-move warning

Simon Marchi
2017-06-21T21:05:52Z

On 2017-06-21 22:29, Sergio Durigan Junior wrote:
> On Wednesday, June 21 2017, Simon Marchi wrote:
>
>> clang gives this warning:
>>
>> /home/emaisin/src/binutils-gdb/gdb/unittests/environ-selftests.c:139:7:
>> error: explicitly moving variable of type 'gdb_environ' to itself
>> [-Werror,-Wself-move]
>> env = std::move (env);
>> ~~~ ^ ~~~
>>
>> In this case, ignoring the warning locally is clearly the thing to do,
>> since it warns exactly about the behavior we want to test. We also
>> don't want to disable this globally, because we would want the
>> compiler
>
> "we would want the code compiler to warn"

Oops thanks.

>> if we wrote that in real code.
>>
>> I filed a bug in GCC's bugzilla to suggest to add this warning:
>>
>> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81159
>
> Thanks!
>
>> gdb/ChangeLog:
>>
>> * unittests/environ-selftests.c (run_tests): Ignore -Wself-move
>> warning.
>> ---
>> gdb/unittests/environ-selftests.c | 9 +++++++++
>> 1 file changed, 9 insertions(+)
>>
>> diff --git a/gdb/unittests/environ-selftests.c
>> b/gdb/unittests/environ-selftests.c
>> index ecc3955..6989c5e 100644
>> --- a/gdb/unittests/environ-selftests.c
>> +++ b/gdb/unittests/environ-selftests.c
>> @@ -136,7 +136,16 @@ run_tests ()
>> env.clear ();
>> env.set ("A", "1");
>> SELF_CHECK (strcmp (env.get ("A"), "1") == 0);
>> +
>> +#ifdef __clang__
>> +#pragma clang diagnostic push
>> +#pragma clang diagnostic ignored "-Wself-move"
>> +#endif /* __clang__ */
>> env = std::move (env);
>> +#ifdef __clang__
>> +#pragma clang diagnostic pop
>> +#endif /* __clang__ */
>
> Wow. I know we've discussed this before, but this is ugly :-/.
> Anyway,
> this file is just a unittest, so I'm totally fine with this.

Yeah, I didn't expect to have to put the #ifdefs for __clang__ though.
Without them, gcc emits a warning [-Wunknown-pragma]. We always have
the option to turn -Wunknown-pragma off globally, what do you prefer?