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Diffstat (limited to 'rust/bits/src/lib.rs')
| -rw-r--r-- | rust/bits/src/lib.rs | 443 |
1 files changed, 443 insertions, 0 deletions
diff --git a/rust/bits/src/lib.rs b/rust/bits/src/lib.rs new file mode 100644 index 0000000000..d485d6bd11 --- /dev/null +++ b/rust/bits/src/lib.rs @@ -0,0 +1,443 @@ +// SPDX-License-Identifier: MIT or Apache-2.0 or GPL-2.0-or-later + +/// # Definition entry point +/// +/// Define a struct with a single field of type $type. Include public constants +/// for each element listed in braces. +/// +/// The unnamed element at the end, if present, can be used to enlarge the set +/// of valid bits. Bits that are valid but not listed are treated normally for +/// the purpose of arithmetic operations, and are printed with their hexadecimal +/// value. +/// +/// The struct implements the following traits: [`BitAnd`](std::ops::BitAnd), +/// [`BitOr`](std::ops::BitOr), [`BitXor`](std::ops::BitXor), +/// [`Not`](std::ops::Not), [`Sub`](std::ops::Sub); [`Debug`](std::fmt::Debug), +/// [`Display`](std::fmt::Display), [`Binary`](std::fmt::Binary), +/// [`Octal`](std::fmt::Octal), [`LowerHex`](std::fmt::LowerHex), +/// [`UpperHex`](std::fmt::UpperHex); [`From`]`<type>`/[`Into`]`<type>` where +/// type is the type specified in the definition. +/// +/// ## Example +/// +/// ``` +/// # use bits::bits; +/// bits! { +/// pub struct Colors(u8) { +/// BLACK = 0, +/// RED = 1, +/// GREEN = 1 << 1, +/// BLUE = 1 << 2, +/// WHITE = (1 << 0) | (1 << 1) | (1 << 2), +/// } +/// } +/// ``` +/// +/// ``` +/// # use bits::bits; +/// # bits! { pub struct Colors(u8) { BLACK = 0, RED = 1, GREEN = 1 << 1, BLUE = 1 << 2, } } +/// +/// bits! { +/// pub struct Colors8(u8) { +/// BLACK = 0, +/// RED = 1, +/// GREEN = 1 << 1, +/// BLUE = 1 << 2, +/// WHITE = (1 << 0) | (1 << 1) | (1 << 2), +/// +/// _ = 255, +/// } +/// } +/// +/// // The previously defined struct ignores bits not explicitly defined. +/// assert_eq!( +/// Colors::from(255).into_bits(), +/// (Colors::RED | Colors::GREEN | Colors::BLUE).into_bits() +/// ); +/// +/// // Adding "_ = 255" makes it retain other bits as well. +/// assert_eq!(Colors8::from(255).into_bits(), 255); +/// +/// // all() does not include the additional bits, valid_bits() does +/// assert_eq!(Colors8::all().into_bits(), Colors::all().into_bits()); +/// assert_eq!(Colors8::valid_bits().into_bits(), 255); +/// ``` +/// +/// # Evaluation entry point +/// +/// Return a constant corresponding to the boolean expression `$expr`. +/// Identifiers in the expression correspond to values defined for the +/// type `$type`. Supported operators are `!` (unary), `-`, `&`, `^`, `|`. +/// +/// ## Examples +/// +/// ``` +/// # use bits::bits; +/// bits! { +/// pub struct Colors(u8) { +/// BLACK = 0, +/// RED = 1, +/// GREEN = 1 << 1, +/// BLUE = 1 << 2, +/// // same as "WHITE = 7", +/// WHITE = bits!(Self as u8: RED | GREEN | BLUE), +/// } +/// } +/// +/// let rgb = bits! { Colors: RED | GREEN | BLUE }; +/// assert_eq!(rgb, Colors::WHITE); +/// ``` +#[macro_export] +macro_rules! bits { + { + $(#[$struct_meta:meta])* + $struct_vis:vis struct $struct_name:ident($field_vis:vis $type:ty) { + $($(#[$const_meta:meta])* $const:ident = $val:expr),+ + $(,_ = $mask:expr)? + $(,)? + } + } => { + $(#[$struct_meta])* + #[derive(Clone, Copy, PartialEq, Eq)] + #[repr(transparent)] + $struct_vis struct $struct_name($field_vis $type); + + impl $struct_name { + $( #[allow(dead_code)] $(#[$const_meta])* + pub const $const: $struct_name = $struct_name($val); )+ + + #[doc(hidden)] + const VALID__: $type = $( Self::$const.0 )|+ $(|$mask)?; + + #[allow(dead_code)] + #[inline(always)] + pub const fn empty() -> Self { + Self(0) + } + + #[allow(dead_code)] + #[inline(always)] + pub const fn all() -> Self { + Self($( Self::$const.0 )|+) + } + + #[allow(dead_code)] + #[inline(always)] + pub const fn valid_bits() -> Self { + Self(Self::VALID__) + } + + #[allow(dead_code)] + #[inline(always)] + pub const fn valid(val: $type) -> bool { + (val & !Self::VALID__) == 0 + } + + #[allow(dead_code)] + #[inline(always)] + pub const fn any_set(self, mask: Self) -> bool { + (self.0 & mask.0) != 0 + } + + #[allow(dead_code)] + #[inline(always)] + pub const fn all_set(self, mask: Self) -> bool { + (self.0 & mask.0) == mask.0 + } + + #[allow(dead_code)] + #[inline(always)] + pub const fn none_set(self, mask: Self) -> bool { + (self.0 & mask.0) == 0 + } + + #[allow(dead_code)] + #[inline(always)] + pub const fn from_bits(value: $type) -> Self { + $struct_name(value) + } + + #[allow(dead_code)] + #[inline(always)] + pub const fn into_bits(self) -> $type { + self.0 + } + + #[allow(dead_code)] + #[inline(always)] + pub fn set(&mut self, rhs: Self) { + self.0 |= rhs.0; + } + + #[allow(dead_code)] + #[inline(always)] + pub fn clear(&mut self, rhs: Self) { + self.0 &= !rhs.0; + } + + #[allow(dead_code)] + #[inline(always)] + pub fn toggle(&mut self, rhs: Self) { + self.0 ^= rhs.0; + } + + #[allow(dead_code)] + #[inline(always)] + pub const fn intersection(self, rhs: Self) -> Self { + $struct_name(self.0 & rhs.0) + } + + #[allow(dead_code)] + #[inline(always)] + pub const fn difference(self, rhs: Self) -> Self { + $struct_name(self.0 & !rhs.0) + } + + #[allow(dead_code)] + #[inline(always)] + pub const fn symmetric_difference(self, rhs: Self) -> Self { + $struct_name(self.0 ^ rhs.0) + } + + #[allow(dead_code)] + #[inline(always)] + pub const fn union(self, rhs: Self) -> Self { + $struct_name(self.0 | rhs.0) + } + + #[allow(dead_code)] + #[inline(always)] + pub const fn invert(self) -> Self { + $struct_name(self.0 ^ Self::VALID__) + } + } + + impl ::std::fmt::Binary for $struct_name { + fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result { + // If no width, use the highest valid bit + let width = f.width().unwrap_or((Self::VALID__.ilog2() + 1) as usize); + write!(f, "{:0>width$.precision$b}", self.0, + width = width, + precision = f.precision().unwrap_or(width)) + } + } + + impl ::std::fmt::LowerHex for $struct_name { + fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result { + <$type as ::std::fmt::LowerHex>::fmt(&self.0, f) + } + } + + impl ::std::fmt::Octal for $struct_name { + fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result { + <$type as ::std::fmt::Octal>::fmt(&self.0, f) + } + } + + impl ::std::fmt::UpperHex for $struct_name { + fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result { + <$type as ::std::fmt::UpperHex>::fmt(&self.0, f) + } + } + + impl ::std::fmt::Debug for $struct_name { + fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result { + write!(f, "{}({})", stringify!($struct_name), self) + } + } + + impl ::std::fmt::Display for $struct_name { + fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result { + use ::std::fmt::Display; + let mut first = true; + let mut left = self.0; + $(if Self::$const.0.is_power_of_two() && (self & Self::$const).0 != 0 { + if first { first = false } else { Display::fmt(&'|', f)?; } + Display::fmt(stringify!($const), f)?; + left -= Self::$const.0; + })+ + if first { + Display::fmt(&'0', f) + } else if left != 0 { + write!(f, "|{left:#x}") + } else { + Ok(()) + } + } + } + + impl ::std::cmp::PartialEq<$type> for $struct_name { + fn eq(&self, rhs: &$type) -> bool { + self.0 == *rhs + } + } + + impl ::std::ops::BitAnd<$struct_name> for &$struct_name { + type Output = $struct_name; + fn bitand(self, rhs: $struct_name) -> Self::Output { + $struct_name(self.0 & rhs.0) + } + } + + impl ::std::ops::BitAndAssign<$struct_name> for $struct_name { + fn bitand_assign(&mut self, rhs: $struct_name) { + self.0 = self.0 & rhs.0 + } + } + + impl ::std::ops::BitXor<$struct_name> for &$struct_name { + type Output = $struct_name; + fn bitxor(self, rhs: $struct_name) -> Self::Output { + $struct_name(self.0 ^ rhs.0) + } + } + + impl ::std::ops::BitXorAssign<$struct_name> for $struct_name { + fn bitxor_assign(&mut self, rhs: $struct_name) { + self.0 = self.0 ^ rhs.0 + } + } + + impl ::std::ops::BitOr<$struct_name> for &$struct_name { + type Output = $struct_name; + fn bitor(self, rhs: $struct_name) -> Self::Output { + $struct_name(self.0 | rhs.0) + } + } + + impl ::std::ops::BitOrAssign<$struct_name> for $struct_name { + fn bitor_assign(&mut self, rhs: $struct_name) { + self.0 = self.0 | rhs.0 + } + } + + impl ::std::ops::Sub<$struct_name> for &$struct_name { + type Output = $struct_name; + fn sub(self, rhs: $struct_name) -> Self::Output { + $struct_name(self.0 & !rhs.0) + } + } + + impl ::std::ops::SubAssign<$struct_name> for $struct_name { + fn sub_assign(&mut self, rhs: $struct_name) { + self.0 = self.0 - rhs.0 + } + } + + impl ::std::ops::Not for &$struct_name { + type Output = $struct_name; + fn not(self) -> Self::Output { + $struct_name(self.0 ^ $struct_name::VALID__) + } + } + + impl ::std::ops::BitAnd<$struct_name> for $struct_name { + type Output = Self; + fn bitand(self, rhs: Self) -> Self::Output { + $struct_name(self.0 & rhs.0) + } + } + + impl ::std::ops::BitXor<$struct_name> for $struct_name { + type Output = Self; + fn bitxor(self, rhs: Self) -> Self::Output { + $struct_name(self.0 ^ rhs.0) + } + } + + impl ::std::ops::BitOr<$struct_name> for $struct_name { + type Output = Self; + fn bitor(self, rhs: Self) -> Self::Output { + $struct_name(self.0 | rhs.0) + } + } + + impl ::std::ops::Sub<$struct_name> for $struct_name { + type Output = Self; + fn sub(self, rhs: Self) -> Self::Output { + $struct_name(self.0 & !rhs.0) + } + } + + impl ::std::ops::Not for $struct_name { + type Output = Self; + fn not(self) -> Self::Output { + $struct_name(self.0 ^ Self::VALID__) + } + } + + impl From<$struct_name> for $type { + fn from(x: $struct_name) -> $type { + x.0 + } + } + + impl From<$type> for $struct_name { + fn from(x: $type) -> Self { + $struct_name(x & Self::VALID__) + } + } + }; + + { $type:ty: $expr:expr } => { + ::qemu_api_macros::bits_const_internal! { $type @ ($expr) } + }; + + { $type:ty as $int_type:ty: $expr:expr } => { + (::qemu_api_macros::bits_const_internal! { $type @ ($expr) }.into_bits()) as $int_type + }; +} + +#[cfg(test)] +mod test { + bits! { + pub struct InterruptMask(u32) { + OE = 1 << 10, + BE = 1 << 9, + PE = 1 << 8, + FE = 1 << 7, + RT = 1 << 6, + TX = 1 << 5, + RX = 1 << 4, + DSR = 1 << 3, + DCD = 1 << 2, + CTS = 1 << 1, + RI = 1 << 0, + + E = bits!(Self as u32: OE | BE | PE | FE), + MS = bits!(Self as u32: RI | DSR | DCD | CTS), + } + } + + #[test] + pub fn test_not() { + assert_eq!( + !InterruptMask::from(InterruptMask::RT.0), + InterruptMask::E | InterruptMask::MS | InterruptMask::TX | InterruptMask::RX + ); + } + + #[test] + pub fn test_and() { + assert_eq!( + InterruptMask::from(0), + InterruptMask::MS & InterruptMask::OE + ) + } + + #[test] + pub fn test_or() { + assert_eq!( + InterruptMask::E, + InterruptMask::OE | InterruptMask::BE | InterruptMask::PE | InterruptMask::FE + ); + } + + #[test] + pub fn test_xor() { + assert_eq!( + InterruptMask::E ^ InterruptMask::BE, + InterruptMask::OE | InterruptMask::PE | InterruptMask::FE + ); + } +} |