Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

typeintersect: fix another stack overflow caused by circular constraints #54363

Merged
merged 1 commit into from
May 7, 2024
Merged

typeintersect: fix another stack overflow caused by circular constraints #54363

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
24 changes: 13 additions & 11 deletions src/subtype.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1315,6 +1315,8 @@ static int subtype_tuple(jl_datatype_t *xd, jl_datatype_t *yd, jl_stenv_t *e, in
return ans;
}

static int try_subtype_by_bounds(jl_value_t *a, jl_value_t *b, jl_stenv_t *e);

// `param` means we are currently looking at a parameter of a type constructor
// (as opposed to being outside any type constructor, or comparing variable bounds).
// this is used to record the positions where type variables occur for the
Expand Down Expand Up @@ -1365,7 +1367,8 @@ static int subtype(jl_value_t *x, jl_value_t *y, jl_stenv_t *e, int param)
if (yy) record_var_occurrence(yy, e, param);
if (yr) {
record_var_occurrence(xx, e, param);
return subtype(xx->lb, yy->ub, e, 0);
int trysub = e->intersection ? try_subtype_by_bounds(xx->lb, yy->ub, e) : 0;
return trysub || subtype(xx->lb, yy->ub, e, 0);
}
return var_lt((jl_tvar_t*)x, y, e, param);
}
Expand Down Expand Up @@ -2497,7 +2500,7 @@ static jl_value_t *bound_var_below(jl_tvar_t *tv, jl_varbinding_t *bb, jl_stenv_

static int subtype_by_bounds(jl_value_t *x, jl_value_t *y, jl_stenv_t *e) JL_NOTSAFEPOINT;

// similar to `subtype_by_bounds`, used to avoid stack-overflow caused by circulation constraints.
// similar to `subtype_by_bounds`, used to avoid stack-overflow caused by circular constraints.
static int try_subtype_by_bounds(jl_value_t *a, jl_value_t *b, jl_stenv_t *e)
{
if (jl_is_uniontype(a))
Expand All @@ -2506,22 +2509,21 @@ static int try_subtype_by_bounds(jl_value_t *a, jl_value_t *b, jl_stenv_t *e)
else if (jl_is_uniontype(b))
return try_subtype_by_bounds(a, ((jl_uniontype_t *)b)->a, e) ||
try_subtype_by_bounds(a, ((jl_uniontype_t *)b)->b, e);
else if (jl_egal(a, b))
else if (a == jl_bottom_type || b == (jl_value_t *)jl_any_type || obviously_egal(a, b))
return 1;
else if (!jl_is_typevar(b))
return 0;
jl_varbinding_t *vb = e->vars;
while (vb != NULL) {
if (subtype_by_bounds(b, (jl_value_t *)vb->var, e) && obviously_in_union(a, vb->ub))
return 1;
vb = vb->prev;
}
return 0;
else if (jl_is_typevar(a) && subtype_by_bounds(a, b, e))
return 1;
// check if `Union{a, ...} <: b`.
jl_varbinding_t *vb = lookup(e, (jl_tvar_t *)b);
jl_value_t *blb = vb ? vb->lb : ((jl_tvar_t *)b)->lb;
return obviously_in_union(a, blb);
}

static int try_subtype_in_env(jl_value_t *a, jl_value_t *b, jl_stenv_t *e)
{
if (a == jl_bottom_type || b == (jl_value_t *)jl_any_type || try_subtype_by_bounds(a, b, e))
if (try_subtype_by_bounds(a, b, e))
return 1;
jl_savedenv_t se;
save_env(e, &se, 1);
Expand Down
13 changes: 10 additions & 3 deletions test/subtype.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2336,9 +2336,10 @@ T46784{B<:Val, M<:AbstractMatrix} = Tuple{<:Union{B, <:Val{<:B}}, M, Union{Abstr
#issue 36185
let S = Tuple{Type{T},Array{Union{T,Missing},N}} where {T,N},
T = Tuple{Type{T},Array{Union{T,Nothing},N}} where {T,N}
@testintersect(S, T, !Union{})
@test_broken typeintersect(S, T) != S
@test_broken typeintersect(T, S) != T
I = typeintersect(S, T)
@test I == typeintersect(T, S) != Union{}
@test_broken I <: S
@test_broken I <: T
end

#issue 46736
Expand Down Expand Up @@ -2606,3 +2607,9 @@ let S = Type{T53371{A, B, C, D, E}} where {A, B<:R53371{A}, C<:R53371{A}, D<:R53
T = Type{T53371{A, B, C, D, E} where {A, B<:R53371{A}, C<:R53371{A}, D<:R53371{A}, E<:R53371{A}}}
@test !(S <: T)
end

#issue 54356
let S = Tuple{Val{Val{Union{Val{A2}, A2}}}, Val{Val{Union{Val{A2}, Val{A4}, A4}}}} where {A2, A4<:Union{Val{A2}, A2}},
T = Tuple{Vararg{Val{V}}} where {V}
@testintersect(S, T, !Union{})
end