Add 'remark' diagnostic type in clang

[Tobias Grosser]

On 02/28/2014 03:40 AM, Arthur O'Dwyer wrote:
> On Thu, Feb 27, 2014 at 6:23 PM, Tobias Grosser <tobias at grosser.es> wrote:
>
>> On 02/26/2014 10:27 PM, Tobias Grosser wrote:
>>
>>> On 02/26/2014 10:19 PM, Chris Lattner wrote:
>>>
>>>> On Feb 26, 2014, at 2:22 AM, Tobias Grosser <tobias at grosser.es> wrote:
>>>>
>>>>>
>>>>>   3) How to enable 'remarks'
>>>>>
>>>>> We need a way to enable 'remark' diagnostics. Quentin proposed to go
>>>>> for an approach similar to the warning flags. Where we control remarks
>>>>> with '-Rvector', '-Rloop-vector', ...
>>>>>
>>>>> I will read a little bit through the existing option system to better
>>>>> understand what it is doing, possibly adding documentation / cleanups
>>>>> on my way. I will come back with a proposal here.
>>>>>
>>>>
>>>> It’s a bit odd, but since these are diagnostics, why not use the
>>>> existing -W flags?  You should be able to -Werror one of these,
>>>> control them with #pragma clang diagnostics, etc.  It doesn’t seem
>>>> like we need more complexity in this space.
>>>>
>>>
>>> Good point. I will prepare the above patches such that they reuse the
>>> existing infrastructure. If we really see a need for further
>>> adjustments, we can do this incrementally.
>>>
>>
>> I just updated the patch to reflect the conclusions of our discussion.
>> Please review for commit.
>>
>> ------------
>> [PATCH] Add 'remark' diagnostic type in 'clang'
>>
>>
>> A 'remark' is information that is not an error or a warning, but rather
>> some additional information provided to the user. In contrast to a 'note' a
>> 'remark' is an independent diagnostic, whereas a 'note' always depends on
>> another diagnostic.
>>
>> A typical use case for remark nodes is information provided to the user,
>> e.g. information provided by the vectorizer about loops that have been
>> vectorized.
>>
>> This patch provides the initial implementation of 'remarks'. It includes
>> the actual definiton of the remark nodes, their printing as well as basic
>> parameter handling. We are reusing the existing diagnostic parameters which
>> means a remark
>> can be enabled with normal '-Wdiagnostic-name' flags and can be upgraded
>> to an error using '-Werror=diagnostic-name'.
>>
>
> For the record, I strongly recommend that the syntax to enable a remark
> should be "-Wremark=diagnostic-name", and that "-Wdiagnostic-name" should
> (continue to) mean "upgrade this diagnostic to a warning".
> However, I have no objection to the current semantics for an initial
> checkin, as long as nobody uses it as an excuse to keep those semantics
> forever.

Hi Arthur,

thanks for your comment. I personally am not sure if we want to ask each 
user to type the long '-Wremark' every time. Also, the preference of 
such a spelling was not discussed in the previous mails. I propose to 
let this settle for a while to get some experience, or if you feel 
strong about this, to start a specific discussion about this one change.
If we get agreement on this one, we can change the implementation 
accordingly.

Cheers,
Tobias2