How to run lit tests on Mac OSX without gcc?

[Thomas Mader via digitalmars-d-ldc]

On Monday, 28 August 2017 at 06:19:35 UTC, Jacob Carlborg wrote:
> On 2017-08-27 00:31, Thomas Mader wrote:
>
>> You are right and I probably wouldn't be able to get that 
>> merged into upstream this way too.
>> 
>> The thing with Nix is that every dependency need to be fixed 
>> at build time and can't change anymore.
>> I was able to find the code where the path to gcc is searched 
>> for linking and I just replaced "gcc" with "clang" in 
>> driver/tool.cpp.
>> Since the CC environment flag is properly set by nix with the 
>> full path to clang, it can be found and no gcc is needed at 
>> all.
>
> Can you create a symlink called "gcc" pointing to "clang" and 
> package that? To avoid modifying the source code.

This seems to be an unnecessary redirection and isn't the way 
such things are handled in Nix AFAIK.
I need to patch sources any way because there are other inpure 
paths in phobos too.

See the package for dmd for example: 
https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/compilers/dmd/default.nix#L44-L65

But I see that it's a problem to directly use clang because 
without wrapping there might go something wrong.
But if clang wouldn't be supported directly the FreeBSD condition 
would be wrong too.
So with my current knowledge I would suggest that I open a PR to 
add a condition for OSX with clang too.