Recursive value check consider unboxed constructor as having statically known size.

[vicuna]

Original bug ID: 7717
Reporter: @chambart
Assigned to: @chambart
Status: resolved (set by @chambart on 2018-02-01T21:00:04Z)
Resolution: fixed
Priority: normal
Severity: minor
Version: 4.06.0
Fixed in version: 4.07.0+dev/beta2/rc1/rc2
Category: typing

Bug description

The Typecore.classify_expression considers Texp_construct as a construction of statically known size, even for unboxed constructors. The provided example Segfaults.

Steps to reproduce

type a = A of b [@@unboxed]
and b = X of a | Y

let rec a =
A
(if Sys.opaque_identity true then
X a
else
Y)

let v =
match a with
| A (X (A (X v))) ->
v
| _ -> a

[vicuna]

Comment author: @yallop

Thanks for the report, chambart! There's a PR to fix this issue here:

#1593