Hello,

I'd like to include the version control revision tag in a program. In the C/C++ world I'd make my build system call the compiler like this:

   g++ -D<MY_REVISION_HERE> .....

so that the revision is available as a preprocessor symbol.

Is there an easy way to achieve the same in D? I can think of convoluted solutions, like making the build system generate a .d file containing a constant with the revision tag, but I'd naturally prefer a simpler solution.

I am using DMD, but a solution that works for other D compilers gets extra credit :-)

Thanks!

LMB

Leandro Motta Barros:

> I'd like to include the version control revision tag in a program. In
> the C/C++ world I'd make my build system call the compiler like this:
>
>    g++ -D<MY_REVISION_HERE> .....

Take a look at -version=...

Bye,
bearophile

On Sunday, 31 March 2013 at 02:00:46 UTC, Leandro Motta Barros wrote:
> Hello,
>
> I'd like to include the version control revision tag in a program. In
> the C/C++ world I'd make my build system call the compiler like this:
>
>    g++ -D<MY_REVISION_HERE> .....
>

D has no preprocessor and no way to define global variables via a cmdline switch. The -version switch can be used conditionally compile in blocks of code but wont help you to "import" a value into your program. You can however use import expressions for this.

See http://dlang.org/expression.html search import expression.

---
immutable Revision = import("revision.data");
---
And tell your VCS to always keep the revision in that file. DMD looks for imports in directories specified by the -J option.

On Sun, Mar 31, 2013 at 10:09 AM, Tobias Pankrath <tobias@pankrath.net> wrote:
> On Sunday, 31 March 2013 at 02:00:46 UTC, Leandro Motta Barros wrote:
>>
>> Hello,
>>
>>
>> I'd like to include the version control revision tag in a program. In the C/C++ world I'd make my build system call the compiler like this:
>>
>>    g++ -D<MY_REVISION_HERE> .....
>>
>
> D has no preprocessor and no way to define global variables via a cmdline switch. The -version switch can be used conditionally compile in blocks of code but wont help you to "import" a value into your program. You can however use import expressions for this.
>
> See http://dlang.org/expression.html search import expression.
>
> ---
> immutable Revision = import("revision.data");
> ---
> And tell your VCS to always keep the revision in that file. DMD looks for imports in directories specified by the -J option.

Hello Tobias,

I have (miss)used import expressions before, but I forgot I could use them here.

Thanks a lot!

LMB