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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
commit698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch)
tree173a775858bd501c378080a10dca74132f05bc50 /src/test/ui/derives/deriving-with-repr-packed.rs
parentInitial commit. (diff)
downloadrustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz
rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/test/ui/derives/deriving-with-repr-packed.rs')
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diff --git a/src/test/ui/derives/deriving-with-repr-packed.rs b/src/test/ui/derives/deriving-with-repr-packed.rs
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+#![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, 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() {}