diff options
4 files changed, 64 insertions, 24 deletions
diff --git a/compiler/rustc_mir_transform/src/known_panics_lint.rs b/compiler/rustc_mir_transform/src/known_panics_lint.rs index b8dbf8a759f..b2030efca8f 100644 --- a/compiler/rustc_mir_transform/src/known_panics_lint.rs +++ b/compiler/rustc_mir_transform/src/known_panics_lint.rs @@ -896,13 +896,19 @@ impl CanConstProp { }; for (local, val) in cpv.can_const_prop.iter_enumerated_mut() { let ty = body.local_decls[local].ty; - match tcx.layout_of(param_env.and(ty)) { - Ok(layout) if layout.size < Size::from_bytes(MAX_ALLOC_LIMIT) => {} - // Either the layout fails to compute, then we can't use this local anyway - // or the local is too large, then we don't want to. - _ => { - *val = ConstPropMode::NoPropagation; - continue; + if ty.is_union() { + // Do not const prop unions as they can + // ICE during layout calc + *val = ConstPropMode::NoPropagation; + } else { + match tcx.layout_of(param_env.and(ty)) { + Ok(layout) if layout.size < Size::from_bytes(MAX_ALLOC_LIMIT) => {} + // Either the layout fails to compute, then we can't use this local anyway + // or the local is too large, then we don't want to. + _ => { + *val = ConstPropMode::NoPropagation; + continue; + } } } } diff --git a/tests/crashes/123710.rs b/tests/crashes/123710.rs deleted file mode 100644 index f171fa7cebb..00000000000 --- a/tests/crashes/123710.rs +++ /dev/null @@ -1,17 +0,0 @@ -//@ known-bug: #123710 - -#[repr(packed)] -#[repr(u32)] -enum E { - A, - B, - C, -} - -fn main() { - union InvalidTag { - int: u32, - e: E, - } - let _invalid_tag = InvalidTag { int: 4 }; -} diff --git a/tests/ui/lint/ice-const-prop-unions-known-panics-lint-123710.rs b/tests/ui/lint/ice-const-prop-unions-known-panics-lint-123710.rs new file mode 100644 index 00000000000..2b93d0f8a60 --- /dev/null +++ b/tests/ui/lint/ice-const-prop-unions-known-panics-lint-123710.rs @@ -0,0 +1,22 @@ +// Regression test for issue 123710. +// Tests that the we do not ICE in KnownPanicsLint +// when a union contains an enum with an repr(packed), +// which is a repr not supported for enums + +#[repr(packed)] +//~^ ERROR attribute should be applied to a struct or union +#[repr(u32)] +enum E { + A, + B, + C, +} + +fn main() { + union InvalidTag { + int: u32, + e: E, +//~^ ERROR field must implement `Copy` or be wrapped in `ManuallyDrop<...>` to be used in a union + } + let _invalid_tag = InvalidTag { int: 4 }; +} diff --git a/tests/ui/lint/ice-const-prop-unions-known-panics-lint-123710.stderr b/tests/ui/lint/ice-const-prop-unions-known-panics-lint-123710.stderr new file mode 100644 index 00000000000..44dde6120e8 --- /dev/null +++ b/tests/ui/lint/ice-const-prop-unions-known-panics-lint-123710.stderr @@ -0,0 +1,29 @@ +error[E0517]: attribute should be applied to a struct or union + --> $DIR/ice-const-prop-unions-known-panics-lint-123710.rs:6:8 + | +LL | #[repr(packed)] + | ^^^^^^ +... +LL | / enum E { +LL | | A, +LL | | B, +LL | | C, +LL | | } + | |_- not a struct or union + +error[E0740]: field must implement `Copy` or be wrapped in `ManuallyDrop<...>` to be used in a union + --> $DIR/ice-const-prop-unions-known-panics-lint-123710.rs:18:9 + | +LL | e: E, + | ^^^^ + | + = note: union fields must not have drop side-effects, which is currently enforced via either `Copy` or `ManuallyDrop<...>` +help: wrap the field type in `ManuallyDrop<...>` + | +LL | e: std::mem::ManuallyDrop<E>, + | +++++++++++++++++++++++ + + +error: aborting due to 2 previous errors + +Some errors have detailed explanations: E0517, E0740. +For more information about an error, try `rustc --explain E0517`. |