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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:13 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:13 +0000 |
commit | 218caa410aa38c29984be31a5229b9fa717560ee (patch) | |
tree | c54bd55eeb6e4c508940a30e94c0032fbd45d677 /tests/ui/structs-enums/enum-non-c-like-repr-c-and-int.rs | |
parent | Releasing progress-linux version 1.67.1+dfsg1-1~progress7.99u1. (diff) | |
download | rustc-218caa410aa38c29984be31a5229b9fa717560ee.tar.xz rustc-218caa410aa38c29984be31a5229b9fa717560ee.zip |
Merging upstream version 1.68.2+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tests/ui/structs-enums/enum-non-c-like-repr-c-and-int.rs')
-rw-r--r-- | tests/ui/structs-enums/enum-non-c-like-repr-c-and-int.rs | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/tests/ui/structs-enums/enum-non-c-like-repr-c-and-int.rs b/tests/ui/structs-enums/enum-non-c-like-repr-c-and-int.rs new file mode 100644 index 000000000..7d15d607d --- /dev/null +++ b/tests/ui/structs-enums/enum-non-c-like-repr-c-and-int.rs @@ -0,0 +1,173 @@ +// run-pass +// This test deserializes an enum in-place by transmuting to a union that +// should have the same layout, and manipulating the tag and payloads +// independently. This verifies that `repr(some_int)` has a stable representation, +// and that we don't miscompile these kinds of manipulations. + +use std::time::Duration; +use std::mem; + +#[repr(C, u8)] +#[derive(Copy, Clone, Eq, PartialEq, Debug)] +enum MyEnum { + A(u32), // Single primitive value + B { x: u8, y: i16, z: u8 }, // Composite, and the offsets of `y` and `z` + // depend on tag being internal + C, // Empty + D(Option<u32>), // Contains an enum + E(Duration), // Contains a struct +} + +#[repr(C)] +struct MyEnumRepr { + tag: MyEnumTag, + payload: MyEnumPayload, +} + +#[repr(C)] +#[allow(non_snake_case)] +union MyEnumPayload { + A: MyEnumVariantA, + B: MyEnumVariantB, + D: MyEnumVariantD, + E: MyEnumVariantE, +} + +#[repr(u8)] #[derive(Copy, Clone)] enum MyEnumTag { A, B, C, D, E } +#[repr(C)] #[derive(Copy, Clone)] struct MyEnumVariantA(u32); +#[repr(C)] #[derive(Copy, Clone)] struct MyEnumVariantB {x: u8, y: i16, z: u8 } +#[repr(C)] #[derive(Copy, Clone)] struct MyEnumVariantD(Option<u32>); +#[repr(C)] #[derive(Copy, Clone)] struct MyEnumVariantE(Duration); + +fn main() { + let result: Vec<Result<MyEnum, ()>> = vec![ + Ok(MyEnum::A(17)), + Ok(MyEnum::B { x: 206, y: 1145, z: 78 }), + Ok(MyEnum::C), + Err(()), + Ok(MyEnum::D(Some(407))), + Ok(MyEnum::D(None)), + Ok(MyEnum::E(Duration::from_secs(100))), + Err(()), + ]; + + // Binary serialized version of the above (little-endian) + let input: Vec<u8> = vec![ + 0, 17, 0, 0, 0, + 1, 206, 121, 4, 78, + 2, + 8, /* invalid tag value */ + 3, 0, 151, 1, 0, 0, + 3, 1, + 4, 100, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, /* incomplete value */ + ]; + + let mut output = vec![]; + let mut buf = &input[..]; + + unsafe { + // This should be safe, because we don't match on it unless it's fully formed, + // and it doesn't have a destructor. + // + // MyEnum is repr(C, u8) so it is guaranteed to have a separate discriminant and each + // variant can be zero initialized. + let mut dest: MyEnum = mem::zeroed(); + while buf.len() > 0 { + match parse_my_enum(&mut dest, &mut buf) { + Ok(()) => output.push(Ok(dest)), + Err(()) => output.push(Err(())), + } + } + } + + assert_eq!(output, result); +} + +fn parse_my_enum<'a>(dest: &'a mut MyEnum, buf: &mut &[u8]) -> Result<(), ()> { + unsafe { + // Should be correct to do this transmute. + let dest: &'a mut MyEnumRepr = mem::transmute(dest); + let tag = read_u8(buf)?; + + dest.tag = match tag { + 0 => MyEnumTag::A, + 1 => MyEnumTag::B, + 2 => MyEnumTag::C, + 3 => MyEnumTag::D, + 4 => MyEnumTag::E, + _ => return Err(()), + }; + + match dest.tag { + MyEnumTag::A => { + dest.payload.A.0 = read_u32_le(buf)?; + } + MyEnumTag::B => { + dest.payload.B.x = read_u8(buf)?; + dest.payload.B.y = read_u16_le(buf)? as i16; + dest.payload.B.z = read_u8(buf)?; + } + MyEnumTag::C => { + /* do nothing */ + } + MyEnumTag::D => { + let is_some = read_u8(buf)? == 0; + if is_some { + dest.payload.D.0 = Some(read_u32_le(buf)?); + } else { + dest.payload.D.0 = None; + } + } + MyEnumTag::E => { + let secs = read_u64_le(buf)?; + let nanos = read_u32_le(buf)?; + dest.payload.E.0 = Duration::new(secs, nanos); + } + } + Ok(()) + } +} + + + +// reader helpers + +fn read_u64_le(buf: &mut &[u8]) -> Result<u64, ()> { + if buf.len() < 8 { return Err(()) } + let val = (buf[0] as u64) << 0 + | (buf[1] as u64) << 8 + | (buf[2] as u64) << 16 + | (buf[3] as u64) << 24 + | (buf[4] as u64) << 32 + | (buf[5] as u64) << 40 + | (buf[6] as u64) << 48 + | (buf[7] as u64) << 56; + *buf = &buf[8..]; + Ok(val) +} + +fn read_u32_le(buf: &mut &[u8]) -> Result<u32, ()> { + if buf.len() < 4 { return Err(()) } + let val = (buf[0] as u32) << 0 + | (buf[1] as u32) << 8 + | (buf[2] as u32) << 16 + | (buf[3] as u32) << 24; + *buf = &buf[4..]; + Ok(val) +} + +fn read_u16_le(buf: &mut &[u8]) -> Result<u16, ()> { + if buf.len() < 2 { return Err(()) } + let val = (buf[0] as u16) << 0 + | (buf[1] as u16) << 8; + *buf = &buf[2..]; + Ok(val) +} + +fn read_u8(buf: &mut &[u8]) -> Result<u8, ()> { + if buf.len() < 1 { return Err(()) } + let val = buf[0]; + *buf = &buf[1..]; + Ok(val) +} |