fix #22787, another bounds circularity in type intersection#38245
fix #22787, another bounds circularity in type intersection#38245
Conversation
JeffBezanson
added
types and dispatch
JeffBezanson
force-pushed
the
jb/fix22787
branch
from
86609ec to
2ff075e
Compare
|
(The single tester_macos64 failure is in Distributed and appears unrelated.) |
|
(tester_linuxaarch64 timed out with no preceding failures.) |
Sacha0
left a comment
Sacha0
left a comment
There was a problem hiding this comment.
I do not fully understand the context of the changes to intersect and so can't comment meaningfully on those changes, but comparto_var in isolation seems sensical to me and the tests look good. Thanks Jeff! :)
|
If no one beats me to it, and absent objections or requests for time, I plan to merge these changes on November 2 late in the day PT. Thanks again Jeff! |
test/subtype.jl
Outdated
| # for now check that these don't stack overflow | ||
| @test_broken typeintersect(Tuple{Type{Q}, Q, Ref{Q}} where Q<:Ref, | ||
| Tuple{Type{S}, Union{Ref{S}, Ref{R}}, R} where R where S) != Union{} | ||
| @test_broken typeintersect(Tuple{Type{T}, T, Ref{T}} where T, | ||
| Tuple{Type{S}, Ref{S}, S} where S) != Union{} |
There was a problem hiding this comment.
If I'm not mistaken, @test_broken passes, even if they do stack overflow:
Here's an example of these tests passing on master, despite the stack overflow:
julia> # for now check that these don't stack overflow
@test_broken typeintersect(Tuple{Type{Q}, Q, Ref{Q}} where Q<:Ref,
Tuple{Type{S}, Union{Ref{S}, Ref{R}}, R} where R where S) != Union{}
Test Broken
Expression: typeintersect(Tuple{Type{Q}, Q, Ref{Q}} where Q <: Ref, (Tuple{Type{S}, Union{Ref{S}, Ref{R}}, R} where R) where S) != Union{}
julia> @test_broken typeintersect(Tuple{Type{T}, T, Ref{T}} where T,
Tuple{Type{S}, Ref{S}, S} where S) != Union{}
Test Broken
Expression: typeintersect(Tuple{Type{T}, T, Ref{T}} where T, Tuple{Type{S}, Ref{S}, S} where S) != Union{}
julia> # You can see that it's stack overflowing when we remove the `@test_broken`:
@test typeintersect(Tuple{Type{Q}, Q, Ref{Q}} where Q<:Ref,
Tuple{Type{S}, Union{Ref{S}, Ref{R}}, R} where R where S) != Union{}
Error During Test at REPL[4]:2
Test threw exception
Expression: typeintersect(Tuple{Type{Q}, Q, Ref{Q}} where Q <: Ref, (Tuple{Type{S}, Union{Ref{S}, Ref{R}}, R} where R) where S) != Union{}
StackOverflowError:
Stacktrace:
[1] typeintersect(a::Any, b::Any)
@ Base ./reflection.jl:563
[2] top-level scope
@ REPL[4]:2
[3] eval(m::Module, e::Any)
@ Core ./boot.jl:360
...There was a problem hiding this comment.
Maybe you can change to something like this, which would fail if they stack overflow, but still allow the broken intersection test? Thanks!
| # for now check that these don't stack overflow | |
| @test_broken typeintersect(Tuple{Type{Q}, Q, Ref{Q}} where Q<:Ref, | |
| Tuple{Type{S}, Union{Ref{S}, Ref{R}}, R} where R where S) != Union{} | |
| @test_broken typeintersect(Tuple{Type{T}, T, Ref{T}} where T, | |
| Tuple{Type{S}, Ref{S}, S} where S) != Union{} | |
| @testset begin | |
| # These tests don't pass, but for now check that at least they don't stack overflow | |
| t = typeintersect(Tuple{Type{Q}, Q, Ref{Q}} where Q<:Ref, | |
| Tuple{Type{S}, Union{Ref{S}, Ref{R}}, R} where R where S) | |
| @test_broken t != Union{} | |
| t = typeintersect(Tuple{Type{T}, T, Ref{T}} where T, | |
| Tuple{Type{S}, Ref{S}, S} where S) | |
| @test_broken t != Union{} | |
| end |
There was a problem hiding this comment.
The above suggestion passes for me on this branch, and fails on master.
There was a problem hiding this comment.
To stop my head spinning... what's the correct answer to these intersection problems?
There was a problem hiding this comment.
Here's some:
julia> Tuple{Type{Ref}, Ref{Ref}, Ref{Ref}} <: Tuple{Type{T}, Ref{T}, T} where T
true
julia> Tuple{Type{Ref}, Ref{Ref}, Ref{Ref}} <: Tuple{Type{T}, T, Ref{T}} where T
true
julia> Tuple{Type{Ref{<:Ref}}, Ref{Ref{<:Ref}}, Ref{Ref{<:Ref}}} <: Tuple{Type{T}, T, Ref{T}} where T
true
julia> Tuple{Type{Ref{<:Ref}}, Ref{Ref{<:Ref}}, Ref{Ref{<:Ref}}} <: Tuple{Type{T}, T, Ref{T}} where T
true
julia> Tuple{Type{Ref{<:Ref{<:Ref}}}, Ref{Ref{<:Ref{<:Ref}}}, Ref{Ref{<:Ref{<:Ref}}}} <: Tuple{Type{T}, T, Ref{T}} where T
true
julia> Tuple{Type{Ref{<:Ref{<:Ref}}}, Ref{Ref{<:Ref{<:Ref}}}, Ref{Ref{<:Ref{<:Ref}}}} <: Tuple{Type{T}, Ref{T}, T} where T
true
I don't know if there's a general closed-form expression of this, since it seems to be the Union of this out to infinity?
JeffBezanson
force-pushed
the
jb/fix22787
branch
from
2ff075e to
addb20c
Compare
5 participants
Note the added tests are broken, but at least they don't stack overflow. The first test is reduced from the issue. The second test is a simpler version that did not overflow before, but did incorrectly give
Union{}before. That makes me hopeful that this will not make anything worse.