Simon Peyton Jones
Ben
I'm offline, so can't reply on Phab.
Calling mkTypeableBinds in tcRnHsBootDecls isn't quite right, because it'll generate lots of *bindings* whereas all we want is the *Ids* in the GlobalValEnv.
(It's possible that tcg_binds is ignored in the boot-module case, but it's unsavoury to generate the bindings at all. They are generated when we process the main module.)
I suggest the easiest fix is, in mkModIdBinding and mkTypeableTyConBinds, guard the binding-generation with a test for whether isHsBootOrSig is true.
Are you concerned about the bindings being generated at all or merely that they are being added to the typechecking environment? If the latter there is no reason to fear: TcBinds.addTypecheckedBinds (which TcTypeable uses) ensures that no bindings are added to the environment if we are compiling a boot module, addTypecheckedBinds :: TcGblEnv -> [LHsBinds Id] -> TcGblEnv addTypecheckedBinds tcg_env binds | isHsBootOrSig (tcg_src tcg_env) = tcg_env -- Do not add the code for record-selector bindings -- when compiling hs-boot files | otherwise = tcg_env { tcg_binds = foldr unionBags (tcg_binds tcg_env) binds } Of course, we are still doing the work of producing the bindings; if it is this that you are concerned about then I can be more careful in guarding their production. Cheers, - Ben