Mirrors/rust-analyzer
2
0
Fork 0
mirror of https://github.com/rust-lang/rust-analyzer synced 2024-12-27 05:23:24 +00:00
Code Issues Projects Releases Packages Wiki Activity

Auto merge of #16915 - 6d7a:master, r=HKalbasi

Browse source 
fix: Prevent stack overflow in recursive const types

In the evaluation of const values of recursive types certain declarations could cause an endless call-loop within the interpreter (hir-ty’s create_memory_map), which would lead to a stack overflow.
This commit adds a check that prevents values that contain an address in their value (such as TyKind::Ref) from being allocated at the address they contain.
The commit also adds a test for this edge case.
This commit is contained in:
bors 2024-03-24 15:05:14 +00:00
commit 3dfd4c1f4c
2 changed files with 72 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

27
crates/hir-ty/src/consteval/tests.rs
View file

@ -2825,3 +2825,30 @@ fn unsized_local() {
|e| matches!(e, ConstEvalError::MirLowerError(MirLowerError::UnsizedTemporary(_))),
);
}
#[test]
fn recursive_adt() {
check_fail(
r#"
//- minicore: coerce_unsized, index, slice
pub enum TagTree {
Leaf,
Choice(&'static [TagTree]),
}
const GOAL: TagTree = {
const TAG_TREE: TagTree = TagTree::Choice(&[
{
const VARIANT_TAG_TREE: TagTree = TagTree::Choice(
&[
TagTree::Leaf,
],
);
VARIANT_TAG_TREE
},
]);
TAG_TREE
};
"#,
|e| matches!(e, ConstEvalError::MirEvalError(MirEvalError::StackOverflow)),
);
}

51
crates/hir-ty/src/mir/eval.rs
View file

@ -1931,7 +1931,11 @@ impl Evaluator<'_> {
ty: &Ty,
locals: &Locals,
mm: &mut ComplexMemoryMap,
stack_depth_limit: usize,
) -> Result<()> {
if stack_depth_limit.checked_sub(1).is_none() {
return Err(MirEvalError::StackOverflow);
}
match ty.kind(Interner) {
TyKind::Ref(_, _, t) => {
let size = this.size_align_of(t, locals)?;
@ -1970,7 +1974,14 @@ impl Evaluator<'_> {
if let Some(ty) = check_inner {
for i in 0..count {
let offset = element_size * i;
rec(this, &b[offset..offset + element_size], ty, locals, mm)?;
rec(
this,
&b[offset..offset + element_size],
ty,
locals,
mm,
stack_depth_limit - 1,
)?;
}
}
}
@ -1984,7 +1995,14 @@ impl Evaluator<'_> {
let size = this.size_of_sized(inner, locals, "inner of array")?;
for i in 0..len {
let offset = i * size;
rec(this, &bytes[offset..offset + size], inner, locals, mm)?;
rec(
this,
&bytes[offset..offset + size],
inner,
locals,
mm,
stack_depth_limit - 1,
)?;
}
}
chalk_ir::TyKind::Tuple(_, subst) => {
@ -1993,7 +2011,14 @@ impl Evaluator<'_> {
let ty = ty.assert_ty_ref(Interner); // Tuple only has type argument
let offset = layout.fields.offset(id).bytes_usize();
let size = this.layout(ty)?.size.bytes_usize();
rec(this, &bytes[offset..offset + size], ty, locals, mm)?;
rec(
this,
&bytes[offset..offset + size],
ty,
locals,
mm,
stack_depth_limit - 1,
)?;
}
}
chalk_ir::TyKind::Adt(adt, subst) => match adt.0 {
@ -2008,7 +2033,14 @@ impl Evaluator<'_> {
.bytes_usize();
let ty = &field_types[f].clone().substitute(Interner, subst);
let size = this.layout(ty)?.size.bytes_usize();
rec(this, &bytes[offset..offset + size], ty, locals, mm)?;
rec(
this,
&bytes[offset..offset + size],
ty,
locals,
mm,
stack_depth_limit - 1,
)?;
}
}
AdtId::EnumId(e) => {
@ -2027,7 +2059,14 @@ impl Evaluator<'_> {
l.fields.offset(u32::from(f.into_raw()) as usize).bytes_usize();
let ty = &field_types[f].clone().substitute(Interner, subst);
let size = this.layout(ty)?.size.bytes_usize();
rec(this, &bytes[offset..offset + size], ty, locals, mm)?;
rec(
this,
&bytes[offset..offset + size],
ty,
locals,
mm,
stack_depth_limit - 1,
)?;
}
}
}
@ -2038,7 +2077,7 @@ impl Evaluator<'_> {
Ok(())
}
let mut mm = ComplexMemoryMap::default();
rec(self, bytes, ty, locals, &mut mm)?;
rec(self, bytes, ty, locals, &mut mm, self.stack_depth_limit - 1)?;
Ok(mm)
}