Opened 13 years ago

Closed 10 years ago

#759 closed defect (fixed)

scrutinizer: extend special case for result-type of "list-ref"/"list-tail" to handle nested "(pair ...)" types

Reported by: felix winkelmann Owned by: evhan
Priority: not urgent at all Milestone:
Component: compiler Version: 4.7.x
Keywords: scrutinizer list-ref list-tail Cc:
Estimated difficulty:


As pointed out by sjamaan, changeset f335156a069b4be8c3ec90c1c3f5bddb076f2759 doesn't handle nested pair types. This should be added.

Change History (2)

comment:1 Changed 10 years ago by evhan

Owner: changed from felix winkelmann to evhan
Status: newassigned

As of 504ec7a30debc416d300157ffb542e660231f08b, nested pair types that have an equivalent (list ...) form are handled correctly (since they're rewritten as such during simplification).

What isn't handled are nested pair types that we can't safely rewrite to (list ...) type forms. So, I think this ticket now boils down to extending the special case s.t. it walks pair type forms as far as possible, too. For example, if foo has type (pair fixnum (pair fixnum *)), (list-ref foo 1) should resolve to type fixnum (even though we don't know for sure whether foo is a proper list).

comment:2 Changed 10 years ago by sjamaan

Resolution: fixed
Status: assignedclosed

Fixed by b946076726a7800301dbf1deac0463829e2498db and more generally/for a few other procedures by the changesets immediately following it.

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