Reduce cost of rebuilding hadrian on change to UserSettings

[bgamari]

I suspect that we should do one of the following to reduce the cost of rebuilding Hadrian when UserSettings is changed,

• Compile all of hadrian with -O0 by default
• Add a OPTIONS_GHC -O0 pragma to src/UserSettings.hs
• Add NOINLINE pragmas to the bindings in src/UserSettings.hs

In all cases the goal is to prevent GHC from giving unfoldings to the bindings in UserSettings, meaning that changes will only require a single-module rebuild and relink.

[angerman]

I think the usersettings should be a file read in by hadrian.

I’ve suggested YAML to @hvr ;-)

[angerman]

I should have thought of dhall, not sure why I keep forgetting its name.

[angerman]

Maybe @Gabriel439 has something to say in support or against using dhall for this?

[bgamari]

On November 16, 2017 9:50:37 PM EST, Moritz Angermann notifications@github.com wrote:

Maybe @Gabriel439 has something to say in support or against using dhall for this?

I think there would need to be a very good reason for us to accept a dependency for this.

[Gabriella439]

I have no context here, but since I was cc:ed I'll derail the discussion by recommending Nix instead =P

See: https://github.com/Gabriel439/slides/blob/master/nix-derivation/slides.md

[hvr]

I’ve suggested YAML to @hvr ;-)

:angry: :rage: :anger: :boom: :skull_and_crossbones: ;-)

[snowleopard]

I believe this has been fixed.