[cmake-developers] Add command line options for deprecation message control

[Brad King]

On 09/19/2015 06:32 PM, Michael Scott wrote:
> whether the -W options are intended to only be applicable
> for the message command (and so the current behaviour is correct),
> or whether they should affect all author and deprecated messages
> output by other parts of CMake?

The -Wdev/-Wno-dev options have always been for all messages
output by any part of CMake.  This needs to be preserved/corrected.

> If the current behaviour isn't correct, then one thing to have a
> good think about, is how to handle turning warnings into errors
> when -Werr-dev or -Werr-deprecated (and also the required behaviour
> when -Wno- is used). As some users of IssueMessage do different
> things if an error occurs (and is output), *after* IssueMessage
> is called. So there might need to be a way to signal to the caller
> when a warning has been upgraded to an error because of the users
> options perhaps?

Likely yes.  This may require sweeping changes to address.  We're
too close to the freeze for 3.4 to do this now.  Perhaps we should
simply remove -Werr-dev for now.

Thanks,
-Brad