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// Copyright 2023 The Fuchsia Authors
//
// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
// This file may not be copied, modified, or distributed except according to
// those terms.
// See comment in `include.rs` for why we disable the prelude.
#![no_implicit_prelude]
#![allow(warnings)]
include!("include.rs");
// A struct is `imp::TryFromBytes` if:
// - all fields are `imp::TryFromBytes`
#[test]
fn zst() {
// FIXME(#5): Use `try_transmute` in this test once it's available.
let candidate = ::zerocopy::Ptr::from_ref(&());
let candidate = candidate.forget_aligned();
// SAFETY: `&()` trivially consists entirely of initialized bytes.
let candidate = unsafe { candidate.assume_initialized() };
let is_bit_valid = <() as imp::TryFromBytes>::is_bit_valid(candidate);
imp::assert!(is_bit_valid);
}
#[derive(imp::TryFromBytes)]
#[repr(C)]
struct One {
a: u8,
}
util_assert_impl_all!(One: imp::TryFromBytes);
#[test]
fn one() {
// FIXME(#5): Use `try_transmute` in this test once it's available.
let candidate = ::zerocopy::Ptr::from_ref(&One { a: 42 });
let candidate = candidate.forget_aligned();
// SAFETY: `&One` consists entirely of initialized bytes.
let candidate = unsafe { candidate.assume_initialized() };
let is_bit_valid = <One as imp::TryFromBytes>::is_bit_valid(candidate);
imp::assert!(is_bit_valid);
}
#[derive(imp::TryFromBytes)]
#[repr(C)]
struct Two {
a: bool,
b: (),
}
util_assert_impl_all!(Two: imp::TryFromBytes);
#[test]
fn two() {
// FIXME(#5): Use `try_transmute` in this test once it's available.
let candidate = ::zerocopy::Ptr::from_ref(&Two { a: false, b: () });
let candidate = candidate.forget_aligned();
// SAFETY: `&Two` consists entirely of initialized bytes.
let candidate = unsafe { candidate.assume_initialized() };
let is_bit_valid = <Two as imp::TryFromBytes>::is_bit_valid(candidate);
imp::assert!(is_bit_valid);
}
#[test]
fn two_bad() {
// FIXME(#5): Use `try_transmute` in this test once it's available.
let candidate = ::zerocopy::Ptr::from_ref(&[2u8][..]);
let candidate = candidate.forget_aligned();
// SAFETY: `&Two` consists entirely of initialized bytes.
let candidate = unsafe { candidate.assume_initialized() };
// SAFETY:
// - The cast preserves address and size. As a result, the cast will address
// the same bytes as `c`.
// - The cast preserves provenance.
// - Neither the input nor output types contain any `UnsafeCell`s.
let candidate = unsafe { candidate.cast_unsized_unchecked(|p| p.cast::<Two>()) };
// SAFETY: `candidate`'s referent is as-initialized as `Two`.
let candidate = unsafe { candidate.assume_initialized() };
let is_bit_valid = <Two as imp::TryFromBytes>::is_bit_valid(candidate);
imp::assert!(!is_bit_valid);
}
#[derive(imp::TryFromBytes)]
#[repr(C)]
struct Unsized {
a: [u8],
}
util_assert_impl_all!(Unsized: imp::TryFromBytes);
#[test]
fn un_sized() {
// FIXME(#5): Use `try_transmute` in this test once it's available.
let candidate = ::zerocopy::Ptr::from_ref(&[16, 12, 42][..]);
let candidate = candidate.forget_aligned();
// SAFETY: `&Unsized` consists entirely of initialized bytes.
let candidate = unsafe { candidate.assume_initialized() };
// SAFETY:
// - The cast preserves address and size. As a result, the cast will address
// the same bytes as `c`.
// - The cast preserves provenance.
// - Neither the input nor output types contain any `UnsafeCell`s.
let candidate = unsafe {
candidate.cast_unsized_unchecked(|p| {
let ptr =
imp::core::ptr::NonNull::new_unchecked(p.as_non_null().as_ptr() as *mut Unsized);
::zerocopy::pointer::PtrInner::new(ptr)
})
};
// SAFETY: `candidate`'s referent is as-initialized as `Two`.
let candidate = unsafe { candidate.assume_initialized() };
let is_bit_valid = <Unsized as imp::TryFromBytes>::is_bit_valid(candidate);
imp::assert!(is_bit_valid);
}
#[derive(imp::TryFromBytes)]
#[repr(C)]
struct TypeParams<'a, T: ?imp::Sized, I: imp::Iterator> {
a: I::Item,
b: u8,
c: imp::PhantomData<&'a [u8]>,
d: imp::PhantomData<&'static str>,
e: imp::PhantomData<imp::String>,
f: T,
}
util_assert_impl_all!(TypeParams<'static, (), imp::IntoIter<()>>: imp::TryFromBytes);
util_assert_impl_all!(TypeParams<'static, util::AU16, imp::IntoIter<()>>: imp::TryFromBytes);
util_assert_impl_all!(TypeParams<'static, [util::AU16], imp::IntoIter<()>>: imp::TryFromBytes);
// Deriving `imp::TryFromBytes` should work if the struct has bounded parameters.
#[derive(imp::TryFromBytes)]
#[repr(transparent)]
struct WithParams<'a: 'b, 'b: 'a, T: 'a + 'b + imp::TryFromBytes, const N: usize>(
imp::PhantomData<&'a &'b ()>,
[T],
)
where
'a: 'b,
'b: 'a,
T: 'a + 'b + imp::TryFromBytes;
util_assert_impl_all!(WithParams<'static, 'static, u8, 42>: imp::TryFromBytes);
#[derive(imp::FromBytes)]
#[repr(C)]
struct MaybeFromBytes<T>(T);
#[test]
fn test_maybe_from_bytes() {
// When deriving `FromBytes` on a type with no generic parameters, we emit a
// trivial `is_bit_valid` impl that always returns true. This test confirms
// that we *don't* spuriously do that when generic parameters are present.
let candidate = ::zerocopy::Ptr::from_ref(&[2u8][..]);
let candidate = candidate.bikeshed_recall_initialized_from_bytes();
// SAFETY:
// - The cast preserves address and size. As a result, the cast will address
// the same bytes as `c`.
// - The cast preserves provenance.
// - Neither the input nor output types contain any `UnsafeCell`s.
let candidate =
unsafe { candidate.cast_unsized_unchecked(|p| p.cast::<MaybeFromBytes<bool>>()) };
// SAFETY: `[u8]` consists entirely of initialized bytes.
let candidate = unsafe { candidate.assume_initialized() };
let is_bit_valid = <MaybeFromBytes<bool> as imp::TryFromBytes>::is_bit_valid(candidate);
imp::assert!(!is_bit_valid);
}
#[derive(Debug, PartialEq, Eq, imp::TryFromBytes, imp::Immutable, imp::KnownLayout)]
#[repr(C, packed)]
struct CPacked {
a: u8,
// NOTE: The `u32` type is not guaranteed to have alignment 4, although it
// does on many platforms. However, to fix this would require a custom type
// with a `#[repr(align(4))]` attribute, and `#[repr(packed)]` types are not
// allowed to transitively contain `#[repr(align(...))]` types. Thus, we
// have no choice but to use `u32` here. Luckily, these tests run in CI on
// platforms on which `u32` has alignment 4, so this isn't that big of a
// deal.
b: u32,
}
#[test]
fn c_packed() {
let candidate = &[42u8, 0xFF, 0xFF, 0xFF, 0xFF];
let converted = <CPacked as imp::TryFromBytes>::try_ref_from_bytes(candidate);
imp::assert_eq!(converted, imp::Ok(&CPacked { a: 42, b: u32::MAX }));
}
#[derive(imp::TryFromBytes, imp::KnownLayout, imp::Immutable)]
#[repr(C, packed)]
struct CPackedUnsized {
a: u8,
// NOTE: The `u32` type is not guaranteed to have alignment 4, although it
// does on many platforms. However, to fix this would require a custom type
// with a `#[repr(align(4))]` attribute, and `#[repr(packed)]` types are not
// allowed to transitively contain `#[repr(align(...))]` types. Thus, we
// have no choice but to use `u32` here. Luckily, these tests run in CI on
// platforms on which `u32` has alignment 4, so this isn't that big of a
// deal.
b: [u32],
}
#[test]
fn c_packed_unsized() {
let candidate = &[42u8, 0xFF, 0xFF, 0xFF, 0xFF];
let converted = <CPackedUnsized as imp::TryFromBytes>::try_ref_from_bytes(candidate);
imp::assert!(converted.is_ok());
}
#[derive(imp::TryFromBytes)]
#[repr(packed)]
struct PackedUnsized {
a: u8,
// NOTE: The `u32` type is not guaranteed to have alignment 4, although it
// does on many platforms. However, to fix this would require a custom type
// with a `#[repr(align(4))]` attribute, and `#[repr(packed)]` types are not
// allowed to transitively contain `#[repr(align(...))]` types. Thus, we
// have no choice but to use `u32` here. Luckily, these tests run in CI on
// platforms on which `u32` has alignment 4, so this isn't that big of a
// deal.
b: [u32],
}
#[test]
fn packed_unsized() {
let candidate = &[42u8, 0xFF, 0xFF, 0xFF, 0xFF];
let converted = <CPackedUnsized as imp::TryFromBytes>::try_ref_from_bytes(candidate);
imp::assert!(converted.is_ok());
let candidate = &[42u8, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF];
let converted = <CPackedUnsized as imp::TryFromBytes>::try_ref_from_bytes(candidate);
imp::assert!(converted.is_err());
let candidate = &[42u8, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF];
let converted = <CPackedUnsized as imp::TryFromBytes>::try_ref_from_bytes(candidate);
imp::assert!(converted.is_ok());
}
#[derive(imp::TryFromBytes)]
struct A;
#[derive(imp::TryFromBytes)]
struct B {
a: A,
}