Opened 4 years ago
Last modified 2 months ago
#1131 new defect
Kill ##sys#alias-global-hook with fire
Reported by: | sjamaan | Owned by: | |
---|---|---|---|
Priority: | critical | Milestone: | 5.1 |
Component: | unknown | Version: | 4.9.x |
Keywords: | Cc: | ||
Estimated difficulty: | insane |
Description
The whole concept is broken. Just by studying the code it's easy to come up with bug after bug.
Change History (8)
comment:1 Changed 4 years ago by sjamaan
comment:2 Changed 4 years ago by sjamaan
Ideally, we'd also remove ##sys#mark-imported-symbols while we're at it: it's totally unneccessary, because whether a symbol is imported is an aspect of a particular module, not a global status (if we ignore the toplevel).
comment:3 Changed 4 years ago by sjamaan
Another inconsistency:
(module bar (x) (import scheme) (define x 1)) (module foo () (import chicken) (print (#%+ bar#x 1)))
The above program fails with Warning: reference to possibly unbound identifier `bar#x'. If we add bar to the import list (or remove the reference) it will start working, even though we didn't import the primitive module which includes a binding for + (ie, scheme).
This is due to the (sometimes?) different treatment of ##core#aliased and ##core#primitive.
comment:4 Changed 4 years ago by sjamaan
Looks like the first order of business should be to try and eliminate the special handling of primitives.
comment:5 Changed 3 years ago by sjamaan
- Milestone changed from 4.10.0 to 5.0
We're not going to fix this in the CHICKEN 4 branch, but hopefully in the 5 cycle we'll be able to eventually fix it. I'll assign 5.0 as a milestone even though I'm doubtful we'll make it as soon as that.
comment:6 Changed 20 months ago by sjamaan
- Estimated difficulty set to insane
This is the kind of thing that has to die a death by a thousand cuts. That will make it seem "easy", but it will take a long time before we have everything covered.
comment:7 Changed 13 months ago by sjamaan
- Milestone changed from 5.0 to 5.1
Still needs to die, but we won't manage to do that before 5.0
comment:8 Changed 2 months ago by sjamaan
Another catch, from #1441:
(module undef (undefined) (import scheme) (define undefined 1)) (module expando (do-it) (import scheme) (define-syntax do-it (syntax-rules () ((_) (let-syntax ((final (syntax-rules () ((_ ?x) ?x)))) (final undefined)))))) (import undef expando) ;; Should fail, not print 1, because the let-syntax expansion should rename introduced ;; identifiers from its SE (but input should be looked up here) (print (do-it))
Here's the first:
The following code will compile (or run, in csi). If the module definition for another is removed, it doesn't. Why? Because when another imports foo, ##sys#mark-imported-symbols will mark it as ##core#aliased, which means ##sys#alias-global-hook will simply pass it through whenever it's subsequently referenced.
The question is whether a fully qualified module identifier should work within another module regardless of whether it's been imported. This part should be the first to clean up, because ##core#aliased is only used in a handful of places. Unfortunately it's a bit of a mindfuck, because it is really used all over the place, through ##sys#global-alias-hook.