Categorization of warnings

[tsbockman via Digitalmars-d]

On Monday, 28 March 2016 at 16:21:15 UTC, Johan Engelen wrote:
> I just submitted a PR [1] that catagorizes warnings, such that 
> you can do something like this:
> dmd -w -Wno-not-reachable
> which would error on any warning except the "statement not 
> reachable" warnings (it completely disables that warning).
>
> The motivation for the selective disabling/enabling of warnings 
> was a recent discussion in the Learn forum [2].
>
> Please read about it in detail in the first message of the PR 
> [1].
>
> - Johan
>
> [1]  https://github.com/D-Programming-Language/dmd/pull/5592
> [2]  
> http://forum.dlang.org/thread/baupegcfvumouhgauetk@forum.dlang.org

I think categorizing warnings could be useful, but must point out 
that for the "statement not reachable" problem (DMD 14835), 
specifically, this is not really a good long term solution.

The reason is that Phobos itself contains many statements which 
are "not reachable" according to the compiler's current flawed 
definition. (They aren't detected as such only because the 
constant folding and value range propagation capabilities are 
rather weak currently.)

If Phobos requires a -Wno-not-reachable switch to compile, then 
anything that uses Phobos will likely require the switch, also. 
At that point, it makes more sense to just fix/remove the 
warning, rather than selectively disabling it for some projects.