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Diffstat (limited to '')
-rw-r--r-- | src/test/ui/structs-enums/align-struct.rs | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/src/test/ui/structs-enums/align-struct.rs b/src/test/ui/structs-enums/align-struct.rs new file mode 100644 index 000000000..27ef990aa --- /dev/null +++ b/src/test/ui/structs-enums/align-struct.rs @@ -0,0 +1,245 @@ +// run-pass +#![allow(dead_code)] +#![feature(box_syntax)] + +use std::mem; + +// Raising alignment +#[repr(align(16))] +#[derive(Clone, Copy, Debug)] +struct Align16(i32); + +// Lowering has no effect +#[repr(align(1))] +struct Align1(i32); + +// Multiple attributes take the max +#[repr(align(4))] +#[repr(align(16))] +#[repr(align(8))] +struct AlignMany(i32); + +// Raising alignment may not alter size. +#[repr(align(8))] +#[allow(dead_code)] +struct Align8Many { + a: i32, + b: i32, + c: i32, + d: u8, +} + +enum Enum { + #[allow(dead_code)] + A(i32), + B(Align16) +} + +// Nested alignment - use `#[repr(C)]` to suppress field reordering for sizeof test +#[repr(C)] +struct Nested { + a: i32, + b: i32, + c: Align16, + d: i8, +} + +#[repr(packed)] +struct Packed(i32); + +#[repr(align(16))] +struct AlignContainsPacked { + a: Packed, + b: Packed, +} + +#[repr(C, packed(4))] +struct Packed4C { + a: u32, + b: u64, +} + +#[repr(align(16))] +struct AlignContainsPacked4C { + a: Packed4C, + b: u64, +} + +// The align limit was originally smaller (2^15). +// Check that it works with big numbers. +#[repr(align(0x10000))] +struct AlignLarge { + stuff: [u8; 0x10000], +} + +union UnionContainsAlign { + a: Align16, + b: f32 +} + +impl Align16 { + // return aligned type + pub fn new(i: i32) -> Align16 { + Align16(i) + } + // pass aligned type + pub fn consume(a: Align16) -> i32 { + a.0 + } +} + +const CONST_ALIGN16: Align16 = Align16(7); +static STATIC_ALIGN16: Align16 = Align16(8); + +// Check the actual address is aligned +fn is_aligned_to<T>(p: &T, align: usize) -> bool { + let addr = p as *const T as usize; + (addr & (align - 1)) == 0 +} + +pub fn main() { + // check alignment and size by type and value + assert_eq!(mem::align_of::<Align16>(), 16); + assert_eq!(mem::size_of::<Align16>(), 16); + + let a = Align16(7); + assert_eq!(a.0, 7); + assert_eq!(mem::align_of_val(&a), 16); + assert_eq!(mem::size_of_val(&a), 16); + + assert!(is_aligned_to(&a, 16)); + + // lowering should have no effect + assert_eq!(mem::align_of::<Align1>(), 4); + assert_eq!(mem::size_of::<Align1>(), 4); + let a = Align1(7); + assert_eq!(a.0, 7); + assert_eq!(mem::align_of_val(&a), 4); + assert_eq!(mem::size_of_val(&a), 4); + assert!(is_aligned_to(&a, 4)); + + // when multiple attributes are specified the max should be used + assert_eq!(mem::align_of::<AlignMany>(), 16); + assert_eq!(mem::size_of::<AlignMany>(), 16); + let a = AlignMany(7); + assert_eq!(a.0, 7); + assert_eq!(mem::align_of_val(&a), 16); + assert_eq!(mem::size_of_val(&a), 16); + assert!(is_aligned_to(&a, 16)); + + // raising alignment should not reduce size + assert_eq!(mem::align_of::<Align8Many>(), 8); + assert_eq!(mem::size_of::<Align8Many>(), 16); + let a = Align8Many { a: 1, b: 2, c: 3, d: 4 }; + assert_eq!(a.a, 1); + assert_eq!(mem::align_of_val(&a), 8); + assert_eq!(mem::size_of_val(&a), 16); + assert!(is_aligned_to(&a, 8)); + + // return type + let a = Align16::new(1); + assert_eq!(mem::align_of_val(&a), 16); + assert_eq!(mem::size_of_val(&a), 16); + assert_eq!(a.0, 1); + assert!(is_aligned_to(&a, 16)); + assert_eq!(Align16::consume(a), 1); + + // check const alignment, size and value + assert_eq!(mem::align_of_val(&CONST_ALIGN16), 16); + assert_eq!(mem::size_of_val(&CONST_ALIGN16), 16); + assert_eq!(CONST_ALIGN16.0, 7); + assert!(is_aligned_to(&CONST_ALIGN16, 16)); + + // check global static alignment, size and value + assert_eq!(mem::align_of_val(&STATIC_ALIGN16), 16); + assert_eq!(mem::size_of_val(&STATIC_ALIGN16), 16); + assert_eq!(STATIC_ALIGN16.0, 8); + assert!(is_aligned_to(&STATIC_ALIGN16, 16)); + + // Note that the size of Nested may change if struct field re-ordering is enabled + assert_eq!(mem::align_of::<Nested>(), 16); + assert_eq!(mem::size_of::<Nested>(), 48); + let a = Nested{ a: 1, b: 2, c: Align16(3), d: 4}; + assert_eq!(mem::align_of_val(&a), 16); + assert_eq!(mem::align_of_val(&a.b), 4); + assert_eq!(mem::align_of_val(&a.c), 16); + assert_eq!(mem::size_of_val(&a), 48); + assert!(is_aligned_to(&a, 16)); + // check the correct fields are indexed + assert_eq!(a.a, 1); + assert_eq!(a.b, 2); + assert_eq!(a.c.0, 3); + assert_eq!(a.d, 4); + + // enum should be aligned to max alignment + assert_eq!(mem::align_of::<Enum>(), 16); + assert_eq!(mem::align_of_val(&Enum::B(Align16(0))), 16); + let e = Enum::B(Align16(15)); + match e { + Enum::B(ref a) => { + assert_eq!(a.0, 15); + assert_eq!(mem::align_of_val(a), 16); + assert_eq!(mem::size_of_val(a), 16); + }, + _ => () + } + assert!(is_aligned_to(&e, 16)); + + // check union alignment + assert_eq!(mem::align_of::<UnionContainsAlign>(), 16); + assert_eq!(mem::size_of::<UnionContainsAlign>(), 16); + let u = UnionContainsAlign { a: Align16(10) }; + unsafe { + assert_eq!(mem::align_of_val(&u.a), 16); + assert_eq!(mem::size_of_val(&u.a), 16); + assert_eq!(u.a.0, 10); + let UnionContainsAlign { a } = u; + assert_eq!(a.0, 10); + } + + // arrays of aligned elements should also be aligned + assert_eq!(mem::align_of::<[Align16;2]>(), 16); + assert_eq!(mem::size_of::<[Align16;2]>(), 32); + + let a = [Align16(0), Align16(1)]; + assert_eq!(mem::align_of_val(&a[0]), 16); + assert_eq!(mem::align_of_val(&a[1]), 16); + assert!(is_aligned_to(&a, 16)); + + // check heap value is aligned + assert_eq!(mem::align_of_val(Box::new(Align16(0)).as_ref()), 16); + + // check heap array is aligned + let a = vec!(Align16(0), Align16(1)); + assert_eq!(mem::align_of_val(&a[0]), 16); + assert_eq!(mem::align_of_val(&a[1]), 16); + + assert_eq!(mem::align_of::<AlignContainsPacked>(), 16); + assert_eq!(mem::size_of::<AlignContainsPacked>(), 16); + let a = AlignContainsPacked { a: Packed(1), b: Packed(2) }; + assert_eq!(mem::align_of_val(&a), 16); + assert_eq!(mem::align_of_val(&a.a), 1); + assert_eq!(mem::align_of_val(&a.b), 1); + assert_eq!(mem::size_of_val(&a), 16); + assert!(is_aligned_to(&a, 16)); + + assert_eq!(mem::align_of::<AlignContainsPacked4C>(), 16); + assert_eq!(mem::size_of::<AlignContainsPacked4C>(), 32); + let a = AlignContainsPacked4C { a: Packed4C{ a: 1, b: 2 }, b: 3 }; + assert_eq!(mem::align_of_val(&a), 16); + assert_eq!(mem::align_of_val(&a.a), 4); + assert_eq!(mem::align_of_val(&a.b), mem::align_of::<u64>()); + assert_eq!(mem::size_of_val(&a), 32); + assert!(is_aligned_to(&a, 16)); + + let mut large = box AlignLarge { + stuff: [0; 0x10000], + }; + large.stuff[0] = 132; + *large.stuff.last_mut().unwrap() = 102; + assert_eq!(large.stuff[0], 132); + assert_eq!(large.stuff.last(), Some(&102)); + assert_eq!(mem::align_of::<AlignLarge>(), 0x10000); + assert_eq!(mem::align_of_val(&*large), 0x10000); + assert!(is_aligned_to(&*large, 0x10000)); +} |