Adding ccache-like output caching to dmd

[Stefan Koch]

On Monday, 28 December 2020 at 23:14:02 UTC, Per Nordlöw wrote:
> Has anyone considered integrating into a `dmd` a ccache-like 
> caching of output files indexed by digests based on
>
> - environment variables,
> - process arguments which, in turn, decide
> - input file contents (including import files detected upon 
> first uncached compile)
> - dmd compiler binary fingerprint
> - ...probably something more I missed
>
> Initial call stores that list alongside content hash and 
> resulting binary(s).
>
> If not, would anyone have any strong objections against adding 
> this?

The issue is that because of string imports you don't know the 
full set of files you are depending on.
which means any change can cause any file to be required.