From 218caa410aa38c29984be31a5229b9fa717560ee Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:19:13 +0200 Subject: Merging upstream version 1.68.2+dfsg1. Signed-off-by: Daniel Baumann --- tests/ui/derives/deriving-with-repr-packed.rs | 45 +++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 tests/ui/derives/deriving-with-repr-packed.rs (limited to 'tests/ui/derives/deriving-with-repr-packed.rs') diff --git a/tests/ui/derives/deriving-with-repr-packed.rs b/tests/ui/derives/deriving-with-repr-packed.rs new file mode 100644 index 000000000..3884e3977 --- /dev/null +++ b/tests/ui/derives/deriving-with-repr-packed.rs @@ -0,0 +1,45 @@ +#![deny(unaligned_references)] + +// Check that deriving certain builtin traits on certain packed structs cause +// errors. This happens when the derived trait would need to use a potentially +// misaligned reference. But there are two cases that are allowed: +// - If all the fields within the struct meet the required alignment: 1 for +// `repr(packed)`, or `N` for `repr(packed(N))`. +// - If `Default` is the only trait derived, because it doesn't involve any +// references. + +#[derive(Copy, Clone, Default, PartialEq, Eq)] +//~^ ERROR `Clone` can't be derived on this `#[repr(packed)]` struct with type or const parameters +//~| hard error +//~^^^ ERROR `PartialEq` can't be derived on this `#[repr(packed)]` struct with type or const parameters +//~| hard error +#[repr(packed)] +pub struct Foo(T, T, T); + +#[derive(Default, Hash)] +//~^ ERROR `Hash` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy` +//~| hard error +#[repr(packed)] +pub struct Bar(u32, u32, u32); + +// This one is fine because the field alignment is 1. +#[derive(Default, Hash)] +#[repr(packed)] +pub struct Bar2(u8, i8, bool); + +// This one is fine because the field alignment is 2, matching `packed(2)`. +#[derive(Default, Hash)] +#[repr(packed(2))] +pub struct Bar3(u16, i16, bool); + +// This one is fine because it's not packed. +#[derive(Debug, Default)] +struct Y(usize); + +#[derive(Debug, Default)] +//~^ ERROR `Debug` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy` +//~| hard error +#[repr(packed)] +struct X(Y); + +fn main() {} -- cgit v1.2.3