Skip to content

might_permit_raw_init: also check arrays #79296

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

Closed
wants to merge 3 commits into from
Closed

might_permit_raw_init: also check arrays #79296

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
2825e53
might_permit_raw_init: also check arrays
nico-abram Nov 22, 2020
2af9121
More readable condition
nico-abram Nov 22, 2020
a6f7780
Reorder tests in panic-uninit-zeroed
nico-abram Nov 22, 2020
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
9 changes: 7 additions & 2 deletions compiler/rustc_target/src/abi/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1162,8 +1162,13 @@ impl<'a, Ty> TyAndLayout<'a, Ty> {
// If we have not found an error yet, we need to recursively descend into fields.
match &self.fields {
FieldsShape::Primitive | FieldsShape::Union { .. } => {}
FieldsShape::Array { .. } => {
// FIXME(#66151): For now, we are conservative and do not check arrays.
FieldsShape::Array { count, .. } => {
if !(*count == 0
|| self.field(cx, 0).to_result()?.might_permit_raw_init(cx, zero)?)
{
// Found non empty array with a type that is unhappy about this kind of initialization
return Ok(false);
}
}
FieldsShape::Arbitrary { offsets, .. } => {
for idx in 0..offsets.len() {
Expand Down
102 changes: 101 additions & 1 deletion src/test/ui/intrinsics/panic-uninitialized-zeroed.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -65,59 +65,111 @@ fn main() {
|| mem::uninitialized::<!>(),
"attempted to instantiate uninhabited type `!`"
);
test_panic_msg(
|| mem::uninitialized::<[!; 2]>(),
"attempted to instantiate uninhabited type `[!; 2]`"
);
test_panic_msg(
|| mem::zeroed::<!>(),
"attempted to instantiate uninhabited type `!`"
);
test_panic_msg(
|| mem::zeroed::<[!; 2]>(),
"attempted to instantiate uninhabited type `[!; 2]`"
);
test_panic_msg(
|| MaybeUninit::<!>::uninit().assume_init(),
"attempted to instantiate uninhabited type `!`"
);
test_panic_msg(
|| MaybeUninit::<[!; 2]>::uninit().assume_init(),
"attempted to instantiate uninhabited type `[!; 2]`"
);

test_panic_msg(
|| mem::uninitialized::<Foo>(),
"attempted to instantiate uninhabited type `Foo`"
);
test_panic_msg(
|| mem::uninitialized::<[Foo; 2]>(),
"attempted to instantiate uninhabited type `[Foo; 2]`"
);
test_panic_msg(
|| mem::zeroed::<Foo>(),
"attempted to instantiate uninhabited type `Foo`"
);
test_panic_msg(
|| mem::zeroed::<[Foo; 2]>(),
"attempted to instantiate uninhabited type `[Foo; 2]`"
);
test_panic_msg(
|| MaybeUninit::<Foo>::uninit().assume_init(),
"attempted to instantiate uninhabited type `Foo`"
);
test_panic_msg(
|| MaybeUninit::<[Foo; 2]>::uninit().assume_init(),
"attempted to instantiate uninhabited type `[Foo; 2]`"
);

test_panic_msg(
|| mem::uninitialized::<Bar>(),
"attempted to instantiate uninhabited type `Bar`"
);
test_panic_msg(
|| mem::uninitialized::<[Bar; 4]>(),
"attempted to instantiate uninhabited type `[Bar; 4]`"
);
test_panic_msg(
|| mem::zeroed::<Bar>(),
"attempted to instantiate uninhabited type `Bar`"
);
test_panic_msg(
|| mem::zeroed::<[Bar; 4]>(),
"attempted to instantiate uninhabited type `[Bar; 4]`"
);
test_panic_msg(
|| MaybeUninit::<Bar>::uninit().assume_init(),
"attempted to instantiate uninhabited type `Bar`"
);
test_panic_msg(
|| MaybeUninit::<[Bar; 4]>::uninit().assume_init(),
"attempted to instantiate uninhabited type `[Bar; 4]`"
);

// Types that do not like zero-initialziation
// Types that do not like zero-initialization
test_panic_msg(
|| mem::uninitialized::<fn()>(),
"attempted to leave type `fn()` uninitialized, which is invalid"
);
test_panic_msg(
|| mem::uninitialized::<[fn(); 2]>(),
"attempted to leave type `[fn(); 2]` uninitialized, which is invalid"
);
test_panic_msg(
|| mem::zeroed::<fn()>(),
"attempted to zero-initialize type `fn()`, which is invalid"
);
test_panic_msg(
|| mem::zeroed::<[fn(); 2]>(),
"attempted to zero-initialize type `[fn(); 2]`, which is invalid"
);

test_panic_msg(
|| mem::uninitialized::<*const dyn Send>(),
"attempted to leave type `*const dyn std::marker::Send` uninitialized, which is invalid"
);
test_panic_msg(
|| mem::uninitialized::<[*const dyn Send; 2]>(),
"attempted to leave type `[*const dyn std::marker::Send; 2]` uninitialized, which is invalid"
);
test_panic_msg(
|| mem::zeroed::<*const dyn Send>(),
"attempted to zero-initialize type `*const dyn std::marker::Send`, which is invalid"
);
test_panic_msg(
|| mem::zeroed::<[*const dyn Send; 2]>(),
"attempted to zero-initialize type `[*const dyn std::marker::Send; 2]`, which is invalid"
);

/* FIXME(#66151) we conservatively do not error here yet.
test_panic_msg(
Expand Down Expand Up @@ -146,39 +198,73 @@ fn main() {
"attempted to leave type `(std::ptr::NonNull<u32>, u32, u32)` uninitialized, \
which is invalid"
);
test_panic_msg(
|| mem::uninitialized::<[(NonNull<u32>, u32, u32); 2]>(),
"attempted to leave type `[(std::ptr::NonNull<u32>, u32, u32); 2]` uninitialized, \
which is invalid"
);
test_panic_msg(
|| mem::zeroed::<(NonNull<u32>, u32, u32)>(),
"attempted to zero-initialize type `(std::ptr::NonNull<u32>, u32, u32)`, \
which is invalid"
);
test_panic_msg(
|| mem::zeroed::<[(NonNull<u32>, u32, u32); 2]>(),
"attempted to zero-initialize type `[(std::ptr::NonNull<u32>, u32, u32); 2]`, \
which is invalid"
);

test_panic_msg(
|| mem::uninitialized::<OneVariant_NonZero>(),
"attempted to leave type `OneVariant_NonZero` uninitialized, \
which is invalid"
);
test_panic_msg(
|| mem::uninitialized::<[OneVariant_NonZero; 2]>(),
"attempted to leave type `[OneVariant_NonZero; 2]` uninitialized, \
which is invalid"
);
test_panic_msg(
|| mem::zeroed::<OneVariant_NonZero>(),
"attempted to zero-initialize type `OneVariant_NonZero`, \
which is invalid"
);
test_panic_msg(
|| mem::zeroed::<[OneVariant_NonZero; 2]>(),
"attempted to zero-initialize type `[OneVariant_NonZero; 2]`, \
which is invalid"
);

test_panic_msg(
|| mem::uninitialized::<NoNullVariant>(),
"attempted to leave type `NoNullVariant` uninitialized, \
which is invalid"
);
test_panic_msg(
|| mem::uninitialized::<[NoNullVariant; 2]>(),
"attempted to leave type `[NoNullVariant; 2]` uninitialized, \
which is invalid"
);
test_panic_msg(
|| mem::zeroed::<NoNullVariant>(),
"attempted to zero-initialize type `NoNullVariant`, \
which is invalid"
);
test_panic_msg(
|| mem::zeroed::<[NoNullVariant; 2]>(),
"attempted to zero-initialize type `[NoNullVariant; 2]`, \
which is invalid"
);

// Types that can be zero, but not uninit.
test_panic_msg(
|| mem::uninitialized::<bool>(),
"attempted to leave type `bool` uninitialized, which is invalid"
);
test_panic_msg(
|| mem::uninitialized::<[bool; 2]>(),
"attempted to leave type `[bool; 2]` uninitialized, which is invalid"
);
test_panic_msg(
|| mem::uninitialized::<LR>(),
"attempted to leave type `LR` uninitialized, which is invalid"
Expand All @@ -190,17 +276,31 @@ fn main() {

// Some things that should work.
let _val = mem::zeroed::<bool>();
let _val = mem::zeroed::<[bool; 4]>();
let _val = mem::zeroed::<LR>();
let _val = mem::zeroed::<[LR; 8]>();
let _val = mem::zeroed::<ManuallyDrop<LR>>();
let _val = mem::zeroed::<[ManuallyDrop<LR>; 16]>();
let _val = mem::zeroed::<OneVariant>();
let _val = mem::zeroed::<[OneVariant; 2]>();
let _val = mem::zeroed::<Option<&'static i32>>();
let _val = mem::zeroed::<[Option<&'static i32>; 3]>();
let _val = mem::zeroed::<MaybeUninit<NonNull<u32>>>();
let _val = mem::zeroed::<[MaybeUninit<NonNull<u32>>; 32]>();
let _val = mem::zeroed::<[!; 0]>();
let _val = mem::uninitialized::<MaybeUninit<bool>>();
let _val = mem::uninitialized::<[MaybeUninit<bool>; 1]>();
let _val = mem::uninitialized::<[bool; 0]>();
let _val = mem::uninitialized::<[!; 0]>();
let _val = mem::uninitialized::<[fn(); 0]>();
let _val = mem::uninitialized::<[*const dyn Send; 0]>();

// These are UB because they have not been officially blessed, but we await the resolution
// of <https://github.com/rust-lang/unsafe-code-guidelines/issues/71> before doing
// anything about that.
let _val = mem::uninitialized::<i32>();
let _val = mem::uninitialized::<[i32; 1]>();
let _val = mem::uninitialized::<*const ()>();
let _val = mem::uninitialized::<[*const (); 2]>();
}
}