diff options
Diffstat (limited to 'tests/ui/transmutability/unions/repr')
4 files changed, 188 insertions, 0 deletions
diff --git a/tests/ui/transmutability/unions/repr/should_handle_align.rs b/tests/ui/transmutability/unions/repr/should_handle_align.rs new file mode 100644 index 000000000..09c13cc4d --- /dev/null +++ b/tests/ui/transmutability/unions/repr/should_handle_align.rs @@ -0,0 +1,47 @@ +// check-pass +//! The presence of an `align(X)` annotation must be accounted for. + +#![crate_type = "lib"] +#![feature(transmutability)] +#![allow(dead_code, incomplete_features, non_camel_case_types)] + +mod assert { + use std::mem::{Assume, BikeshedIntrinsicFrom}; + pub struct Context; + + pub fn is_maybe_transmutable<Src, Dst>() + where + Dst: BikeshedIntrinsicFrom<Src, Context, { + Assume { + alignment: true, + lifetimes: true, + safety: true, + validity: true, + } + }> + {} +} + +fn should_pad_explicitly_aligned_field() { + #[derive(Clone, Copy)] #[repr(u8)] enum V0u8 { V = 0 } + #[derive(Clone, Copy)] #[repr(u8)] enum V1u8 { V = 1 } + + #[repr(C)] + pub union Uninit { + a: (), + b: V1u8, + } + + #[repr(C, align(2))] + pub union align_2 { + a: V0u8, + } + + #[repr(C)] struct ImplicitlyPadded(align_2, V0u8); + #[repr(C)] struct ExplicitlyPadded(V0u8, Uninit, V0u8); + + // An implementation that (incorrectly) does not place a padding byte after + // `align_2` will, incorrectly, reject the following transmutations. + assert::is_maybe_transmutable::<ImplicitlyPadded, ExplicitlyPadded>(); + assert::is_maybe_transmutable::<ExplicitlyPadded, ImplicitlyPadded>(); +} diff --git a/tests/ui/transmutability/unions/repr/should_handle_packed.rs b/tests/ui/transmutability/unions/repr/should_handle_packed.rs new file mode 100644 index 000000000..24c2abd69 --- /dev/null +++ b/tests/ui/transmutability/unions/repr/should_handle_packed.rs @@ -0,0 +1,48 @@ +// check-pass +//! The presence of an `align(X)` annotation must be accounted for. + +#![crate_type = "lib"] +#![feature(transmutability)] +#![allow(dead_code, incomplete_features, non_camel_case_types)] + +mod assert { + use std::mem::{Assume, BikeshedIntrinsicFrom}; + pub struct Context; + + pub fn is_maybe_transmutable<Src, Dst>() + where + Dst: BikeshedIntrinsicFrom<Src, Context, { + Assume { + alignment: true, + lifetimes: true, + safety: true, + validity: true, + } + }> + {} +} + +fn should_pad_explicitly_packed_field() { + #[derive(Clone, Copy)] #[repr(u8)] enum V0u8 { V = 0 } + #[derive(Clone, Copy)] #[repr(u8)] enum V1u8 { V = 1 } + #[derive(Clone, Copy)] #[repr(u8)] enum V2u8 { V = 2 } + #[derive(Clone, Copy)] #[repr(u32)] enum V3u32 { V = 3 } + + #[repr(C)] + pub union Uninit { + a: (), + b: V1u8, + } + + #[repr(C, packed(2))] + pub union Packed { + a: [V3u32; 0], + b: V0u8, + } + + #[repr(C)] struct ImplicitlyPadded(Packed, V2u8); + #[repr(C)] struct ExplicitlyPadded(V0u8, Uninit, V2u8); + + assert::is_maybe_transmutable::<ImplicitlyPadded, ExplicitlyPadded>(); + assert::is_maybe_transmutable::<ExplicitlyPadded, ImplicitlyPadded>(); +} diff --git a/tests/ui/transmutability/unions/repr/should_require_well_defined_layout.rs b/tests/ui/transmutability/unions/repr/should_require_well_defined_layout.rs new file mode 100644 index 000000000..b1d5f71dc --- /dev/null +++ b/tests/ui/transmutability/unions/repr/should_require_well_defined_layout.rs @@ -0,0 +1,44 @@ +//! A struct must have a well-defined layout to participate in a transmutation. + +#![crate_type = "lib"] +#![feature(transmutability)] +#![allow(dead_code, incomplete_features, non_camel_case_types)] + +mod assert { + use std::mem::{Assume, BikeshedIntrinsicFrom}; + pub struct Context; + + pub fn is_maybe_transmutable<Src, Dst>() + where + Dst: BikeshedIntrinsicFrom<Src, Context, { + Assume { + alignment: true, + lifetimes: true, + safety: true, + validity: true, + } + }> + {} +} + +fn should_reject_repr_rust() +{ + union repr_rust { + a: u8 + } + + assert::is_maybe_transmutable::<repr_rust, ()>(); //~ ERROR cannot be safely transmuted + assert::is_maybe_transmutable::<u128, repr_rust>(); //~ ERROR cannot be safely transmuted +} + +fn should_accept_repr_C() +{ + #[repr(C)] + union repr_c { + a: u8 + } + + struct repr_rust; + assert::is_maybe_transmutable::<repr_c, ()>(); + assert::is_maybe_transmutable::<u128, repr_c>(); +} diff --git a/tests/ui/transmutability/unions/repr/should_require_well_defined_layout.stderr b/tests/ui/transmutability/unions/repr/should_require_well_defined_layout.stderr new file mode 100644 index 000000000..523bde85a --- /dev/null +++ b/tests/ui/transmutability/unions/repr/should_require_well_defined_layout.stderr @@ -0,0 +1,49 @@ +error[E0277]: `should_reject_repr_rust::repr_rust` cannot be safely transmuted into `()` in the defining scope of `assert::Context`. + --> $DIR/should_require_well_defined_layout.rs:30:48 + | +LL | assert::is_maybe_transmutable::<repr_rust, ()>(); + | ^^ `should_reject_repr_rust::repr_rust` cannot be safely transmuted into `()` in the defining scope of `assert::Context`. + | + = help: the trait `BikeshedIntrinsicFrom<should_reject_repr_rust::repr_rust, assert::Context, Assume { alignment: true, lifetimes: true, safety: true, validity: true }>` is not implemented for `()` +note: required by a bound in `is_maybe_transmutable` + --> $DIR/should_require_well_defined_layout.rs:13:14 + | +LL | pub fn is_maybe_transmutable<Src, Dst>() + | --------------------- required by a bound in this +LL | where +LL | Dst: BikeshedIntrinsicFrom<Src, Context, { + | ______________^ +LL | | Assume { +LL | | alignment: true, +LL | | lifetimes: true, +... | +LL | | } +LL | | }> + | |__________^ required by this bound in `is_maybe_transmutable` + +error[E0277]: `u128` cannot be safely transmuted into `should_reject_repr_rust::repr_rust` in the defining scope of `assert::Context`. + --> $DIR/should_require_well_defined_layout.rs:31:43 + | +LL | assert::is_maybe_transmutable::<u128, repr_rust>(); + | ^^^^^^^^^ `u128` cannot be safely transmuted into `should_reject_repr_rust::repr_rust` in the defining scope of `assert::Context`. + | + = help: the trait `BikeshedIntrinsicFrom<u128, assert::Context, Assume { alignment: true, lifetimes: true, safety: true, validity: true }>` is not implemented for `should_reject_repr_rust::repr_rust` +note: required by a bound in `is_maybe_transmutable` + --> $DIR/should_require_well_defined_layout.rs:13:14 + | +LL | pub fn is_maybe_transmutable<Src, Dst>() + | --------------------- required by a bound in this +LL | where +LL | Dst: BikeshedIntrinsicFrom<Src, Context, { + | ______________^ +LL | | Assume { +LL | | alignment: true, +LL | | lifetimes: true, +... | +LL | | } +LL | | }> + | |__________^ required by this bound in `is_maybe_transmutable` + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0277`. |