only perfom when the output is missing

[Faré]

One way to avoid unneeded regeneration in the future without lying
about the dependency would be to modify the script to:
1. Remember in the output the hash of the input.
2. In the regeneration script, have a shortcut that leaves the output
unchanged if the input matches.

That won't help if you have to deal with branches back in time, but in
those cases, you can use touch to reset the .h file to an old date.

—♯ƒ • François-René ÐVB Rideau •Reflection&Cybernethics• http://fare.tunes.org
The greatest lies always come in a thin coating of truth.


On Sat, Apr 17, 2021 at 4:44 PM Attila Lendvai <attila.lendvai at gmail.com> wrote:
>
> thanks for the ideas Robert!
>
>>
>> I was wondering why it was important to avoid the build when the .h file is newer than the .spec file. This shouldn't happen very often, should it? Is it because:
>
>
> the problem is much more down to earth: generating the spec file requires launching a libllvm based external tool called c2ffi. compiling and properly configuring this tool can sometimes consume a day, and the users of e.g. hu.dwim.sdl shouldn't ever need to do that. it's only needed when you want to capture newly added artifacts from the SDL.h files.
>
> one way to avoid this could be to not communicate the dependency to ASDF, and make the .h -> .spec generation manual (this used to be the case). for some reason that feels lame, but not the end of the world either.
>
>> The .h file is getting refreshed too often by something upstream of ASDF? E.g., is make being too eager about rewriting the .h file?
>
>
> the problem is not with too often, but with anything greater than zero, e.g. a git checkout.
>
> - attila