command line option or other method for determining the front end version of gdc

[Iain Buclaw via D.gnu]

On 24 July 2016 at 19:00, dan via D.gnu <d.gnu at puremagic.com> wrote:
> One of my machines (running ubuntu mate 16.04) did some update and gdc is no
> longer able to compile a library that i like to use (gtkd).
>
> So i want to build a gdc using an earlier front-end to avoid the problem.
>
> However, i don't know what front end is compiled into gdc, so i'm unclear on
> which front-end to try get an earlier version of.
>
> If i run the command
>     gdc --version
> it gives me the gcc version.
>
> The command
>     gdc --verbose --version
> gives a lot more information, but i can't tell the front end version from
> that either.
>
> Even running commands like
>     strings /usr/bin/gdc | grep .....
> doesn't seem to reveal the version.  (I think the version is probably 2.06*
> but '2.06' and '206' do not appear in the strings.)
>
> Nevertheless i'm sure the information must be there.
>
> TIA for any info!

Later versions will write this out during compilation of a file under -v.

  $ gdc -v test.d
  # ...
  version   v2.068.2
  # ...

For earlier versions, there is a universal way to do it in code.

pragma(msg, __VERSION__);