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[byteorder] Implement core::ops traits #434

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Oct 2, 2023
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[byteorder] Implement core::ops traits #434

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8 changes: 4 additions & 4 deletions Cargo.toml
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Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,7 @@
[package]
edition = "2021"
name = "zerocopy"
version = "0.7.5"
version = "0.7.6"
authors = ["Joshua Liebow-Feeser <joshlf@google.com>"]
description = "Utilities for zero-copy parsing and serialization"
license = "BSD-2-Clause"
Expand Down Expand Up @@ -41,7 +41,7 @@ simd-nightly = ["simd"]
__internal_use_only_features_that_work_on_stable = ["alloc", "derive", "simd"]

[dependencies]
zerocopy-derive = { version = "=0.7.5", path = "zerocopy-derive", optional = true }
zerocopy-derive = { version = "=0.7.6", path = "zerocopy-derive", optional = true }

[dependencies.byteorder]
version = "1.3"
Expand All @@ -52,7 +52,7 @@ optional = true
# zerocopy-derive remain equal, even if the 'derive' feature isn't used.
# See: https://github.com/matklad/macro-dep-test
[target.'cfg(any())'.dependencies]
zerocopy-derive = { version = "=0.7.5", path = "zerocopy-derive" }
zerocopy-derive = { version = "=0.7.6", path = "zerocopy-derive" }

[dev-dependencies]
assert_matches = "1.5"
Expand All @@ -67,4 +67,4 @@ testutil = { path = "testutil" }
# CI test failures.
trybuild = "=1.0.80"
# In tests, unlike in production, zerocopy-derive is not optional
zerocopy-derive = { version = "=0.7.5", path = "zerocopy-derive" }
zerocopy-derive = { version = "=0.7.6", path = "zerocopy-derive" }
270 changes: 254 additions & 16 deletions src/byteorder.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -93,13 +93,12 @@ macro_rules! impl_fmt_traits {
impl_fmt_trait!($name, $native, Display);
};
($name:ident, $native:ident, "unsigned integer") => {
impl_fmt_traits!($name, $native, @all_traits);
impl_fmt_traits!($name, $native, @all_types);
};
($name:ident, $native:ident, "signed integer") => {
impl_fmt_traits!($name, $native, @all_traits);
impl_fmt_traits!($name, $native, @all_types);
};

($name:ident, $native:ident, @all_traits) => {
($name:ident, $native:ident, @all_types) => {
impl_fmt_trait!($name, $native, Display);
impl_fmt_trait!($name, $native, Octal);
impl_fmt_trait!($name, $native, LowerHex);
Expand All @@ -108,6 +107,101 @@ macro_rules! impl_fmt_traits {
};
}

macro_rules! impl_ops_traits {
($name:ident, $native:ident, "floating point number") => {
impl_ops_traits!($name, $native, @all_types);
impl_ops_traits!($name, $native, @signed_integer_floating_point);
};
($name:ident, $native:ident, "unsigned integer") => {
impl_ops_traits!($name, $native, @signed_unsigned_integer);
impl_ops_traits!($name, $native, @all_types);
};
($name:ident, $native:ident, "signed integer") => {
impl_ops_traits!($name, $native, @signed_unsigned_integer);
impl_ops_traits!($name, $native, @signed_integer_floating_point);
impl_ops_traits!($name, $native, @all_types);
};
($name:ident, $native:ident, @signed_unsigned_integer) => {
impl_ops_traits!(@without_byteorder_swap $name, $native, BitAnd, bitand, BitAndAssign, bitand_assign);
impl_ops_traits!(@without_byteorder_swap $name, $native, BitOr, bitor, BitOrAssign, bitor_assign);
impl_ops_traits!(@without_byteorder_swap $name, $native, BitXor, bitxor, BitXorAssign, bitxor_assign);
impl_ops_traits!(@with_byteorder_swap $name, $native, Shl, shl, ShlAssign, shl_assign);
impl_ops_traits!(@with_byteorder_swap $name, $native, Shr, shr, ShrAssign, shr_assign);

impl<O> core::ops::Not for $name<O> {
type Output = $name<O>;

#[inline(always)]
fn not(self) -> $name<O> {
let self_native = $native::from_ne_bytes(self.0);
$name((!self_native).to_ne_bytes(), PhantomData)
}
}
};
($name:ident, $native:ident, @signed_integer_floating_point) => {
impl<O: ByteOrder> core::ops::Neg for $name<O> {
type Output = $name<O>;

#[inline(always)]
fn neg(self) -> $name<O> {
let self_native: $native = self.get();
#[allow(clippy::arithmetic_side_effects)]
$name::<O>::new(-self_native)
}
}
};
($name:ident, $native:ident, @all_types) => {
impl_ops_traits!(@with_byteorder_swap $name, $native, Add, add, AddAssign, add_assign);
impl_ops_traits!(@with_byteorder_swap $name, $native, Div, div, DivAssign, div_assign);
impl_ops_traits!(@with_byteorder_swap $name, $native, Mul, mul, MulAssign, mul_assign);
impl_ops_traits!(@with_byteorder_swap $name, $native, Rem, rem, RemAssign, rem_assign);
impl_ops_traits!(@with_byteorder_swap $name, $native, Sub, sub, SubAssign, sub_assign);
};
(@with_byteorder_swap $name:ident, $native:ident, $trait:ident, $method:ident, $trait_assign:ident, $method_assign:ident) => {
impl<O: ByteOrder> core::ops::$trait for $name<O> {
type Output = $name<O>;

#[inline(always)]
fn $method(self, rhs: $name<O>) -> $name<O> {
let self_native: $native = self.get();
let rhs_native: $native = rhs.get();
let result_native = core::ops::$trait::$method(self_native, rhs_native);
$name::<O>::new(result_native)
}
}

impl<O: ByteOrder> core::ops::$trait_assign for $name<O> {
#[inline(always)]
fn $method_assign(&mut self, rhs: $name<O>) {
*self = core::ops::$trait::$method(*self, rhs);
}
}
};
// Implement traits in terms of the same trait on the native type, but
// without performing a byte order swap. This only works for bitwise
// operations like `&`, `|`, etc.
(@without_byteorder_swap $name:ident, $native:ident, $trait:ident, $method:ident, $trait_assign:ident, $method_assign:ident) => {
impl<O: ByteOrder> core::ops::$trait for $name<O> {
type Output = $name<O>;

#[inline(always)]
fn $method(self, rhs: $name<O>) -> $name<O> {
let self_native = $native::from_ne_bytes(self.0);
let rhs_native = $native::from_ne_bytes(rhs.0);
let result_native = core::ops::$trait::$method(self_native, rhs_native);
$name(result_native.to_ne_bytes(), PhantomData)
}
}

impl<O: ByteOrder> core::ops::$trait_assign for $name<O> {
#[inline(always)]
fn $method_assign(&mut self, rhs: $name<O>) {
*self = core::ops::$trait::$method(*self, rhs);
}
}
};
}

macro_rules! doc_comment {
($x:expr, $($tt:tt)*) => {
#[doc = $x]
Expand Down Expand Up @@ -347,6 +441,7 @@ example of how it can be used for parsing UDP packets.
}

impl_fmt_traits!($name, $native, $number_kind);
impl_ops_traits!($name, $native, $number_kind);

impl<O: ByteOrder> Debug for $name<O> {
#[inline]
Expand Down Expand Up @@ -566,6 +661,14 @@ mod tests {
}

fn is_nan(self) -> bool;

fn checked_add(self, rhs: Self) -> Option<Self>;
fn checked_div(self, rhs: Self) -> Option<Self>;
fn checked_mul(self, rhs: Self) -> Option<Self>;
fn checked_rem(self, rhs: Self) -> Option<Self>;
fn checked_sub(self, rhs: Self) -> Option<Self>;
fn checked_shl(self, rhs: Self) -> Option<Self>;
fn checked_shr(self, rhs: Self) -> Option<Self>;
}

trait ByteArray:
Expand Down Expand Up @@ -618,7 +721,7 @@ mod tests {
}

macro_rules! impl_traits {
($name:ident, $native:ident, $bytes:expr, $sign:ident $(, $is_nan:ident)?) => {
($name:ident, $native:ident, $bytes:expr, $sign:ident $(, @$float:ident)?) => {
impl Native for $native {
// For some types, `0 as $native` is required (for example, when
// `$native` is a floating-point type; `0` is an integer), but
Expand All @@ -631,9 +734,7 @@ mod tests {
type Distribution = Standard;
const DIST: Standard = Standard;

fn is_nan(self) -> bool {
false $(|| self.$is_nan())?
}
impl_traits!(@float_dependent_methods $(@$float)?);
}

impl<O: ByteOrder> ByteOrderType for $name<O> {
Expand Down Expand Up @@ -665,6 +766,26 @@ mod tests {

impl_byte_order_type_unsigned!($name, $sign);
};
(@float_dependent_methods) => {
fn is_nan(self) -> bool { false }
fn checked_add(self, rhs: Self) -> Option<Self> { self.checked_add(rhs) }
fn checked_div(self, rhs: Self) -> Option<Self> { self.checked_div(rhs) }
fn checked_mul(self, rhs: Self) -> Option<Self> { self.checked_mul(rhs) }
fn checked_rem(self, rhs: Self) -> Option<Self> { self.checked_rem(rhs) }
fn checked_sub(self, rhs: Self) -> Option<Self> { self.checked_sub(rhs) }
fn checked_shl(self, rhs: Self) -> Option<Self> { self.checked_shl(rhs.try_into().unwrap_or(u32::MAX)) }
fn checked_shr(self, rhs: Self) -> Option<Self> { self.checked_shr(rhs.try_into().unwrap_or(u32::MAX)) }
};
(@float_dependent_methods @float) => {
fn is_nan(self) -> bool { self.is_nan() }
fn checked_add(self, rhs: Self) -> Option<Self> { Some(self + rhs) }
fn checked_div(self, rhs: Self) -> Option<Self> { Some(self / rhs) }
fn checked_mul(self, rhs: Self) -> Option<Self> { Some(self * rhs) }
fn checked_rem(self, rhs: Self) -> Option<Self> { Some(self % rhs) }
fn checked_sub(self, rhs: Self) -> Option<Self> { Some(self - rhs) }
fn checked_shl(self, _rhs: Self) -> Option<Self> { unimplemented!() }
fn checked_shr(self, _rhs: Self) -> Option<Self> { unimplemented!() }
};
}

impl_traits!(U16, u16, 2, unsigned);
Expand All @@ -675,30 +796,39 @@ mod tests {
impl_traits!(I32, i32, 4, signed);
impl_traits!(I64, i64, 8, signed);
impl_traits!(I128, i128, 16, signed);
impl_traits!(F32, f32, 4, signed, is_nan);
impl_traits!(F64, f64, 8, signed, is_nan);
impl_traits!(F32, f32, 4, signed, @float);
impl_traits!(F64, f64, 8, signed, @float);

macro_rules! call_for_all_types {
macro_rules! call_for_unsigned_types {
($fn:ident, $byteorder:ident) => {
$fn::<U16<$byteorder>>();
$fn::<U32<$byteorder>>();
$fn::<U64<$byteorder>>();
$fn::<U128<$byteorder>>();
};
}

macro_rules! call_for_signed_types {
($fn:ident, $byteorder:ident) => {
$fn::<I16<$byteorder>>();
$fn::<I32<$byteorder>>();
$fn::<I64<$byteorder>>();
$fn::<I128<$byteorder>>();
};
}

macro_rules! call_for_float_types {
($fn:ident, $byteorder:ident) => {
$fn::<F32<$byteorder>>();
$fn::<F64<$byteorder>>();
};
}

macro_rules! call_for_unsigned_types {
macro_rules! call_for_all_types {
($fn:ident, $byteorder:ident) => {
$fn::<U16<$byteorder>>();
$fn::<U32<$byteorder>>();
$fn::<U64<$byteorder>>();
$fn::<U128<$byteorder>>();
call_for_unsigned_types!($fn, $byteorder);
call_for_signed_types!($fn, $byteorder);
call_for_float_types!($fn, $byteorder);
};
}

Expand Down Expand Up @@ -834,6 +964,114 @@ mod tests {
call_for_all_types!(test_non_native_endian, NonNativeEndian);
}

#[cfg_attr(test, test)]
fn test_ops_impls() {
// Test implementations of traits in `core::ops`. Some of these are
// fairly banal, but some are optimized to perform the operation without
// swapping byte order (namely, bit-wise operations which are identical
// regardless of byte order). These are important to test, and while
// we're testing those anyway, it's trivial to test all of the impls.

fn test<T, F, G, H>(op: F, op_native: G, op_native_checked: Option<H>)
where
T: ByteOrderType,
F: Fn(T, T) -> T,
G: Fn(T::Native, T::Native) -> T::Native,
H: Fn(T::Native, T::Native) -> Option<T::Native>,
{
let mut r = SmallRng::seed_from_u64(RNG_SEED);
for _ in 0..RAND_ITERS {
let n0 = T::Native::rand(&mut r);
let n1 = T::Native::rand(&mut r);
let t0 = T::new(n0);
let t1 = T::new(n1);

// If this operation would overflow/underflow, skip it rather
// than attempt to catch and recover from panics.
if matches!(&op_native_checked, Some(checked) if checked(n0, n1).is_none()) {
continue;
}

let n_res = op_native(n0, n1);
let t_res = op(t0, t1);

// For `f32` and `f64`, NaN values are not considered equal to
// themselves. We store `Option<f32>`/`Option<f64>` and store
// NaN as `None` so they can still be compared.
let n_res = (!T::Native::is_nan(n_res)).then(|| n_res);
let t_res = (!T::Native::is_nan(t_res.get())).then(|| t_res.get());
assert_eq!(n_res, t_res);
}
}

macro_rules! test {
(@binary $trait:ident, $method:ident $([$checked_method:ident])?, $($call_for_macros:ident),*) => {{
test!(
@inner $trait,
core::ops::$trait::$method,
core::ops::$trait::$method,
{
#[allow(unused_mut, unused_assignments)]
let mut op_native_checked = None::<fn(T::Native, T::Native) -> Option<T::Native>>;
$(
op_native_checked = Some(T::Native::$checked_method);
)?
op_native_checked
},
$($call_for_macros),*
);
}};
(@unary $trait:ident, $method:ident $([$checked_method:ident])?, $($call_for_macros:ident),*) => {{
test!(
@inner $trait,
|slf, _rhs| core::ops::$trait::$method(slf),
|slf, _rhs| core::ops::$trait::$method(slf),
{
#[allow(unused_mut, unused_assignments)]
let mut op_native_checked = None::<fn(T::Native, T::Native) -> Option<T::Native>>;
$(
op_native_checked = Some(|slf, _rhs| T::Native::$checked_method(slf));
)?
op_native_checked
},
$($call_for_macros),*
);
}};
(@inner $trait:ident, $op:expr, $op_native:expr, $op_native_checked:expr, $($call_for_macros:ident),*) => {{
fn t<T: ByteOrderType + core::ops::$trait<Output = T>>()
where
T::Native: core::ops::$trait<Output = T::Native>,
{
test::<T, _, _, _>(
$op,
$op_native,
$op_native_checked,
);
}

$(
$call_for_macros!(t, NativeEndian);
$call_for_macros!(t, NonNativeEndian);
)*
}};
}

test!(@binary Add, add[checked_add], call_for_all_types);
test!(@binary Div, div[checked_div], call_for_all_types);
test!(@binary Mul, mul[checked_mul], call_for_all_types);
test!(@binary Rem, rem[checked_rem], call_for_all_types);
test!(@binary Sub, sub[checked_sub], call_for_all_types);

test!(@binary BitAnd, bitand, call_for_unsigned_types, call_for_signed_types);
test!(@binary BitOr, bitor, call_for_unsigned_types, call_for_signed_types);
test!(@binary BitXor, bitxor, call_for_unsigned_types, call_for_signed_types);
test!(@binary Shl, shl[checked_shl], call_for_unsigned_types, call_for_signed_types);
test!(@binary Shr, shr[checked_shr], call_for_unsigned_types, call_for_signed_types);

test!(@unary Not, not, call_for_signed_types, call_for_unsigned_types);
test!(@unary Neg, neg, call_for_signed_types, call_for_float_types);
}

#[test]
fn test_debug_impl() {
// Ensure that Debug applies format options to the inner value.
Expand Down