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Diffstat (limited to 'vendor/bytemuck/tests/cast_slice_tests.rs')
-rw-r--r-- | vendor/bytemuck/tests/cast_slice_tests.rs | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/vendor/bytemuck/tests/cast_slice_tests.rs b/vendor/bytemuck/tests/cast_slice_tests.rs new file mode 100644 index 0000000..ce6dedc --- /dev/null +++ b/vendor/bytemuck/tests/cast_slice_tests.rs @@ -0,0 +1,197 @@ +#![allow(clippy::unnecessary_cast)] +#![allow(clippy::manual_slice_size_calculation)] + +use core::mem::size_of; + +use bytemuck::*; + +#[test] +fn test_try_cast_slice() { + // some align4 data + let u32_slice: &[u32] = &[4, 5, 6]; + // the same data as align1 + let the_bytes: &[u8] = try_cast_slice(u32_slice).unwrap(); + + assert_eq!( + u32_slice.as_ptr() as *const u32 as usize, + the_bytes.as_ptr() as *const u8 as usize + ); + assert_eq!( + u32_slice.len() * size_of::<u32>(), + the_bytes.len() * size_of::<u8>() + ); + + // by taking one byte off the front, we're definitely mis-aligned for u32. + let mis_aligned_bytes = &the_bytes[1..]; + assert_eq!( + try_cast_slice::<u8, u32>(mis_aligned_bytes), + Err(PodCastError::TargetAlignmentGreaterAndInputNotAligned) + ); + + // by taking one byte off the end, we're aligned but would have slop bytes for + // u32 + let the_bytes_len_minus1 = the_bytes.len() - 1; + let slop_bytes = &the_bytes[..the_bytes_len_minus1]; + assert_eq!( + try_cast_slice::<u8, u32>(slop_bytes), + Err(PodCastError::OutputSliceWouldHaveSlop) + ); + + // if we don't mess with it we can up-alignment cast + try_cast_slice::<u8, u32>(the_bytes).unwrap(); +} + +#[test] +fn test_try_cast_slice_mut() { + // some align4 data + let u32_slice: &mut [u32] = &mut [4, 5, 6]; + let u32_len = u32_slice.len(); + let u32_ptr = u32_slice.as_ptr(); + + // the same data as align1 + let the_bytes: &mut [u8] = try_cast_slice_mut(u32_slice).unwrap(); + let the_bytes_len = the_bytes.len(); + let the_bytes_ptr = the_bytes.as_ptr(); + + assert_eq!( + u32_ptr as *const u32 as usize, + the_bytes_ptr as *const u8 as usize + ); + assert_eq!(u32_len * size_of::<u32>(), the_bytes_len * size_of::<u8>()); + + // by taking one byte off the front, we're definitely mis-aligned for u32. + let mis_aligned_bytes = &mut the_bytes[1..]; + assert_eq!( + try_cast_slice_mut::<u8, u32>(mis_aligned_bytes), + Err(PodCastError::TargetAlignmentGreaterAndInputNotAligned) + ); + + // by taking one byte off the end, we're aligned but would have slop bytes for + // u32 + let the_bytes_len_minus1 = the_bytes.len() - 1; + let slop_bytes = &mut the_bytes[..the_bytes_len_minus1]; + assert_eq!( + try_cast_slice_mut::<u8, u32>(slop_bytes), + Err(PodCastError::OutputSliceWouldHaveSlop) + ); + + // if we don't mess with it we can up-alignment cast + try_cast_slice_mut::<u8, u32>(the_bytes).unwrap(); +} + +#[test] +fn test_types() { + let _: i32 = cast(1.0_f32); + let _: &mut i32 = cast_mut(&mut 1.0_f32); + let _: &i32 = cast_ref(&1.0_f32); + let _: &[i32] = cast_slice(&[1.0_f32]); + let _: &mut [i32] = cast_slice_mut(&mut [1.0_f32]); + // + let _: Result<i32, PodCastError> = try_cast(1.0_f32); + let _: Result<&mut i32, PodCastError> = try_cast_mut(&mut 1.0_f32); + let _: Result<&i32, PodCastError> = try_cast_ref(&1.0_f32); + let _: Result<&[i32], PodCastError> = try_cast_slice(&[1.0_f32]); + let _: Result<&mut [i32], PodCastError> = try_cast_slice_mut(&mut [1.0_f32]); +} + +#[test] +fn test_bytes_of() { + assert_eq!(bytes_of(&0xaabbccdd_u32), &0xaabbccdd_u32.to_ne_bytes()); + assert_eq!( + bytes_of_mut(&mut 0xaabbccdd_u32), + &mut 0xaabbccdd_u32.to_ne_bytes() + ); + let mut a = 0xaabbccdd_u32; + let a_addr = &a as *const _ as usize; + // ensure addresses match. + assert_eq!(bytes_of(&a).as_ptr() as usize, a_addr); + assert_eq!(bytes_of_mut(&mut a).as_ptr() as usize, a_addr); +} + +#[test] +fn test_try_from_bytes() { + let u32s = [0xaabbccdd, 0x11223344_u32]; + let bytes = bytemuck::cast_slice::<u32, u8>(&u32s); + assert_eq!(try_from_bytes::<u32>(&bytes[..4]), Ok(&u32s[0])); + assert_eq!( + try_from_bytes::<u32>(&bytes[..5]), + Err(PodCastError::SizeMismatch) + ); + assert_eq!( + try_from_bytes::<u32>(&bytes[..3]), + Err(PodCastError::SizeMismatch) + ); + assert_eq!( + try_from_bytes::<u32>(&bytes[1..5]), + Err(PodCastError::TargetAlignmentGreaterAndInputNotAligned) + ); +} + +#[test] +fn test_try_from_bytes_mut() { + let mut abcd = 0xaabbccdd; + let mut u32s = [abcd, 0x11223344_u32]; + let bytes = bytemuck::cast_slice_mut::<u32, u8>(&mut u32s); + assert_eq!(try_from_bytes_mut::<u32>(&mut bytes[..4]), Ok(&mut abcd)); + assert_eq!(try_from_bytes_mut::<u32>(&mut bytes[..4]), Ok(&mut abcd)); + assert_eq!( + try_from_bytes_mut::<u32>(&mut bytes[..5]), + Err(PodCastError::SizeMismatch) + ); + assert_eq!( + try_from_bytes_mut::<u32>(&mut bytes[..3]), + Err(PodCastError::SizeMismatch) + ); + assert_eq!( + try_from_bytes::<u32>(&bytes[1..5]), + Err(PodCastError::TargetAlignmentGreaterAndInputNotAligned) + ); +} + +#[test] +fn test_from_bytes() { + let abcd = 0xaabbccdd_u32; + let aligned_bytes = bytemuck::bytes_of(&abcd); + assert_eq!(from_bytes::<u32>(aligned_bytes), &abcd); + assert!(core::ptr::eq(from_bytes(aligned_bytes), &abcd)); +} + +#[test] +fn test_from_bytes_mut() { + let mut a = 0xaabbccdd_u32; + let a_addr = &a as *const _ as usize; + let aligned_bytes = bytemuck::bytes_of_mut(&mut a); + assert_eq!(*from_bytes_mut::<u32>(aligned_bytes), 0xaabbccdd_u32); + assert_eq!( + from_bytes_mut::<u32>(aligned_bytes) as *const u32 as usize, + a_addr + ); +} + +// like #[should_panic], but can be a part of another test, instead of requiring +// it to be it's own test. +macro_rules! should_panic { + ($ex:expr) => { + assert!( + std::panic::catch_unwind(|| { + let _ = $ex; + }) + .is_err(), + concat!("should have panicked: `", stringify!($ex), "`") + ); + }; +} + +#[test] +fn test_panics() { + should_panic!(cast_slice::<u8, u32>(&[1u8, 2u8])); + should_panic!(cast_slice_mut::<u8, u32>(&mut [1u8, 2u8])); + should_panic!(from_bytes::<u32>(&[1u8, 2])); + should_panic!(from_bytes::<u32>(&[1u8, 2, 3, 4, 5])); + should_panic!(from_bytes_mut::<u32>(&mut [1u8, 2])); + should_panic!(from_bytes_mut::<u32>(&mut [1u8, 2, 3, 4, 5])); + // use cast_slice on some u32s to get some align>=4 bytes, so we can know + // we'll give from_bytes unaligned ones. + let aligned_bytes = bytemuck::cast_slice::<u32, u8>(&[0, 0]); + should_panic!(from_bytes::<u32>(&aligned_bytes[1..5])); +} |