Re: committed: remove redundant -Wall from -Warray-bounds (PR 82063)

[Martin Sebor <msebor@gmail.com>]

On 07/24/2018 03:24 AM, Franz Sirl wrote:
> Am 2018-07-20 um 23:22 schrieb Martin Sebor:
>> As the last observation in PR 82063 Jim points out that
>>
>>    Both -Warray-bounds and -Warray-bounds= are listed in the c.opt
>>    file as being enabled by -Wall, but they are the same option,
>>    and it causes this one option to be processed twice in the
>>    C_handle_option_auto function in the generated options.c file.
>>    It gets set to the same value twice, so it does work as intended,
>>    but this is wasteful.
>>
>> I have removed the redundant -Wall from the first option and
>> committed the change as obvious in r262912.
>
> Hi Martin,
>
> this looks related to PR 68845 and my patch in there. I never posted it
> to gcc-patches because I couldn't find a definitive answer on how
> options duplicated between common.opt and c-family/c.opt are supposed to
> be handled.
> For example, Warray-bounds in common.opt is a separate option (not an
> alias to Warray-bounds=), leading to separate enums for them. Is this
> intended? Warray-bounds seemed to be the only option with an equal sign
> doing it like that at that time. Now Wcast-align is doing the same...
>
> Can you shed some light on this?

-Warray-bounds= (the form that takes an argument) was added in
r219577.  Before then, only the plain form existed.  If I had
to guess, the interplay between the two options (as opposed to
making the latter an alias for the new option) wasn't considered.
I didn't think of it until now either.  Your patch seems like
the right solution to me.  Let me know if you will submit it.
If not, I posted the patch below that touches this area and
that will likely need updating so I can roll your change into
it:

https://gcc.gnu.org/ml/gcc-patches/2018-07/msg01286.html

Martin