David Feuer
I started digging back into this today, particularly considering Simon PJ's view that it's a bit odd for optimization flags to imply -fobject-code (specifically because we could potentially support optimization for the bytecode interpreter some day). I'm left even more lost about exactly what we want. I believe it's fairly clear that, as Simon M wrote,
[W]e'll want at least -fignore-optim-changes to be the default, so that GHCi does the expected thing when you have compiled object files.
Based on Simon PJ's comment, I believe we want to *continue* to discard optimization flags when -fobject-code is not enabled. As for my suggestion in (2), I spent the last couple hours attempting to figure out what would be necessary to allow :load *M to load a module interpreted even when using -fobject-code, but found myself utterly lost in the module loading logic. I see that the IIModule constructor is deeply involved in this, but I haven't been able to figure out where/how that interacts with -fobject-code to determine whether the module will actually be loaded interpreted or compiled. Can someone give me a clue?
It seems to me like the place to start would be occurrences of the targetAllowObjCode field of Target. Cheers, - Ben