Dataflow: Replace stage duplication with parameterised modules.

[aschackmull]

Appears to work, although there are some complaints of the form

Some errors in uninstantiated parameterised modules are not (yet) reported, so non-trivial binding sets on signatures can introduce errors that only future compiler versions will be able to detect

@ginsbach

[ginsbach]

Appears to work, although there are some complaints of the form

Some errors in uninstantiated parameterised modules are not (yet) reported, so non-trivial binding sets on signatures can introduce errors that only future compiler versions will be able to detect

The removal of that error message is currently still blocked by https://github.com/github/semmle-code/pull/42236. Once we have the frontend binding set checker, we can remove the warning and proceed with this.

[ginsbach]

The blocking warning should be gone, now that we merged https://github.com/github/semmle-code/pull/43179 into main.

[hvitved]

LGTM. Please do a DCA run for all languages as well.

[hvitved]

We could add a // TODO: member predicate on `Ap` comment.

[hvitved]

We could add a // TODO: member predicate on `Ap` comment.

[hvitved]

We have two calls to MkStage<Stage1> (and same for other stages), here and in the module Stage2. Perhaps that is OK, as parameterized modules are not generative?

[aschackmull]

That is indeed perfectly fine.

[aschackmull]

DCA looks good, I think.

[hvitved]

💪

[jketema]

DCA looks good, I think.

Agreed for C++. The vim failure is expected (we're working on it).