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use rustc_apfloat::ieee::{Double, Single};
use rustc_apfloat::Float;
use rustc_errors::{DiagnosticArgValue, IntoDiagnosticArg};
use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
use rustc_target::abi::Size;
use std::fmt;
use std::num::NonZeroU8;
use crate::ty::TyCtxt;
#[derive(Copy, Clone)]
/// A type for representing any integer. Only used for printing.
pub struct ConstInt {
/// The "untyped" variant of `ConstInt`.
int: ScalarInt,
/// Whether the value is of a signed integer type.
signed: bool,
/// Whether the value is a `usize` or `isize` type.
is_ptr_sized_integral: bool,
}
impl ConstInt {
pub fn new(int: ScalarInt, signed: bool, is_ptr_sized_integral: bool) -> Self {
Self { int, signed, is_ptr_sized_integral }
}
}
impl std::fmt::Debug for ConstInt {
fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let Self { int, signed, is_ptr_sized_integral } = *self;
let size = int.size().bytes();
let raw = int.data;
if signed {
let bit_size = size * 8;
let min = 1u128 << (bit_size - 1);
let max = min - 1;
if raw == min {
match (size, is_ptr_sized_integral) {
(_, true) => write!(fmt, "isize::MIN"),
(1, _) => write!(fmt, "i8::MIN"),
(2, _) => write!(fmt, "i16::MIN"),
(4, _) => write!(fmt, "i32::MIN"),
(8, _) => write!(fmt, "i64::MIN"),
(16, _) => write!(fmt, "i128::MIN"),
_ => bug!("ConstInt 0x{:x} with size = {} and signed = {}", raw, size, signed),
}
} else if raw == max {
match (size, is_ptr_sized_integral) {
(_, true) => write!(fmt, "isize::MAX"),
(1, _) => write!(fmt, "i8::MAX"),
(2, _) => write!(fmt, "i16::MAX"),
(4, _) => write!(fmt, "i32::MAX"),
(8, _) => write!(fmt, "i64::MAX"),
(16, _) => write!(fmt, "i128::MAX"),
_ => bug!("ConstInt 0x{:x} with size = {} and signed = {}", raw, size, signed),
}
} else {
match size {
1 => write!(fmt, "{}", raw as i8)?,
2 => write!(fmt, "{}", raw as i16)?,
4 => write!(fmt, "{}", raw as i32)?,
8 => write!(fmt, "{}", raw as i64)?,
16 => write!(fmt, "{}", raw as i128)?,
_ => bug!("ConstInt 0x{:x} with size = {} and signed = {}", raw, size, signed),
}
if fmt.alternate() {
match (size, is_ptr_sized_integral) {
(_, true) => write!(fmt, "_isize")?,
(1, _) => write!(fmt, "_i8")?,
(2, _) => write!(fmt, "_i16")?,
(4, _) => write!(fmt, "_i32")?,
(8, _) => write!(fmt, "_i64")?,
(16, _) => write!(fmt, "_i128")?,
_ => bug!(),
}
}
Ok(())
}
} else {
let max = Size::from_bytes(size).truncate(u128::MAX);
if raw == max {
match (size, is_ptr_sized_integral) {
(_, true) => write!(fmt, "usize::MAX"),
(1, _) => write!(fmt, "u8::MAX"),
(2, _) => write!(fmt, "u16::MAX"),
(4, _) => write!(fmt, "u32::MAX"),
(8, _) => write!(fmt, "u64::MAX"),
(16, _) => write!(fmt, "u128::MAX"),
_ => bug!("ConstInt 0x{:x} with size = {} and signed = {}", raw, size, signed),
}
} else {
match size {
1 => write!(fmt, "{}", raw as u8)?,
2 => write!(fmt, "{}", raw as u16)?,
4 => write!(fmt, "{}", raw as u32)?,
8 => write!(fmt, "{}", raw as u64)?,
16 => write!(fmt, "{}", raw as u128)?,
_ => bug!("ConstInt 0x{:x} with size = {} and signed = {}", raw, size, signed),
}
if fmt.alternate() {
match (size, is_ptr_sized_integral) {
(_, true) => write!(fmt, "_usize")?,
(1, _) => write!(fmt, "_u8")?,
(2, _) => write!(fmt, "_u16")?,
(4, _) => write!(fmt, "_u32")?,
(8, _) => write!(fmt, "_u64")?,
(16, _) => write!(fmt, "_u128")?,
_ => bug!(),
}
}
Ok(())
}
}
}
}
impl IntoDiagnosticArg for ConstInt {
// FIXME this simply uses the Debug impl, but we could probably do better by converting both
// to an inherent method that returns `Cow`.
fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
DiagnosticArgValue::Str(format!("{self:?}").into())
}
}
/// The raw bytes of a simple value.
///
/// This is a packed struct in order to allow this type to be optimally embedded in enums
/// (like Scalar).
#[derive(Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
#[repr(packed)]
pub struct ScalarInt {
/// The first `size` bytes of `data` are the value.
/// Do not try to read less or more bytes than that. The remaining bytes must be 0.
data: u128,
size: NonZeroU8,
}
// Cannot derive these, as the derives take references to the fields, and we
// can't take references to fields of packed structs.
impl<CTX> crate::ty::HashStable<CTX> for ScalarInt {
fn hash_stable(&self, hcx: &mut CTX, hasher: &mut crate::ty::StableHasher) {
// Using a block `{self.data}` here to force a copy instead of using `self.data`
// directly, because `hash_stable` takes `&self` and would thus borrow `self.data`.
// Since `Self` is a packed struct, that would create a possibly unaligned reference,
// which is UB.
{ self.data }.hash_stable(hcx, hasher);
self.size.get().hash_stable(hcx, hasher);
}
}
impl<S: Encoder> Encodable<S> for ScalarInt {
fn encode(&self, s: &mut S) {
let size = self.size.get();
s.emit_u8(size);
s.emit_raw_bytes(&self.data.to_le_bytes()[..size as usize]);
}
}
impl<D: Decoder> Decodable<D> for ScalarInt {
fn decode(d: &mut D) -> ScalarInt {
let mut data = [0u8; 16];
let size = d.read_u8();
data[..size as usize].copy_from_slice(d.read_raw_bytes(size as usize));
ScalarInt { data: u128::from_le_bytes(data), size: NonZeroU8::new(size).unwrap() }
}
}
impl ScalarInt {
pub const TRUE: ScalarInt = ScalarInt { data: 1_u128, size: NonZeroU8::new(1).unwrap() };
pub const FALSE: ScalarInt = ScalarInt { data: 0_u128, size: NonZeroU8::new(1).unwrap() };
#[inline]
pub fn size(self) -> Size {
Size::from_bytes(self.size.get())
}
/// Make sure the `data` fits in `size`.
/// This is guaranteed by all constructors here, but having had this check saved us from
/// bugs many times in the past, so keeping it around is definitely worth it.
#[inline(always)]
fn check_data(self) {
// Using a block `{self.data}` here to force a copy instead of using `self.data`
// directly, because `debug_assert_eq` takes references to its arguments and formatting
// arguments and would thus borrow `self.data`. Since `Self`
// is a packed struct, that would create a possibly unaligned reference, which
// is UB.
debug_assert_eq!(
self.size().truncate(self.data),
{ self.data },
"Scalar value {:#x} exceeds size of {} bytes",
{ self.data },
self.size
);
}
#[inline]
pub fn null(size: Size) -> Self {
Self { data: 0, size: NonZeroU8::new(size.bytes() as u8).unwrap() }
}
#[inline]
pub fn is_null(self) -> bool {
self.data == 0
}
#[inline]
pub fn try_from_uint(i: impl Into<u128>, size: Size) -> Option<Self> {
let data = i.into();
if size.truncate(data) == data {
Some(Self { data, size: NonZeroU8::new(size.bytes() as u8).unwrap() })
} else {
None
}
}
#[inline]
pub fn try_from_int(i: impl Into<i128>, size: Size) -> Option<Self> {
let i = i.into();
// `into` performed sign extension, we have to truncate
let truncated = size.truncate(i as u128);
if size.sign_extend(truncated) as i128 == i {
Some(Self { data: truncated, size: NonZeroU8::new(size.bytes() as u8).unwrap() })
} else {
None
}
}
#[inline]
pub fn try_from_target_usize(i: impl Into<u128>, tcx: TyCtxt<'_>) -> Option<Self> {
Self::try_from_uint(i, tcx.data_layout.pointer_size)
}
#[inline]
pub fn assert_bits(self, target_size: Size) -> u128 {
self.to_bits(target_size).unwrap_or_else(|size| {
bug!("expected int of size {}, but got size {}", target_size.bytes(), size.bytes())
})
}
#[inline]
pub fn to_bits(self, target_size: Size) -> Result<u128, Size> {
assert_ne!(target_size.bytes(), 0, "you should never look at the bits of a ZST");
if target_size.bytes() == u64::from(self.size.get()) {
self.check_data();
Ok(self.data)
} else {
Err(self.size())
}
}
#[inline]
pub fn try_to_target_usize(&self, tcx: TyCtxt<'_>) -> Result<u64, Size> {
Ok(self.to_bits(tcx.data_layout.pointer_size)? as u64)
}
/// Tries to convert the `ScalarInt` to an unsigned integer of the given size.
/// Fails if the size of the `ScalarInt` is not equal to `size` and returns the
/// `ScalarInt`s size in that case.
#[inline]
pub fn try_to_uint(self, size: Size) -> Result<u128, Size> {
self.to_bits(size)
}
// Tries to convert the `ScalarInt` to `bool`. Fails if the `size` of the `ScalarInt`
// in not equal to `Size { raw: 1 }` or if the value is not 0 or 1 and returns the `size`
// value of the `ScalarInt` in that case.
#[inline]
pub fn try_to_bool(self) -> Result<bool, Size> {
match self.try_to_u8()? {
0 => Ok(false),
1 => Ok(true),
_ => Err(self.size()),
}
}
// Tries to convert the `ScalarInt` to `u8`. Fails if the `size` of the `ScalarInt`
// in not equal to `Size { raw: 1 }` and returns the `size` value of the `ScalarInt` in
// that case.
#[inline]
pub fn try_to_u8(self) -> Result<u8, Size> {
self.to_bits(Size::from_bits(8)).map(|v| u8::try_from(v).unwrap())
}
/// Tries to convert the `ScalarInt` to `u16`. Fails if the size of the `ScalarInt`
/// in not equal to `Size { raw: 2 }` and returns the `size` value of the `ScalarInt` in
/// that case.
#[inline]
pub fn try_to_u16(self) -> Result<u16, Size> {
self.to_bits(Size::from_bits(16)).map(|v| u16::try_from(v).unwrap())
}
/// Tries to convert the `ScalarInt` to `u32`. Fails if the `size` of the `ScalarInt`
/// in not equal to `Size { raw: 4 }` and returns the `size` value of the `ScalarInt` in
/// that case.
#[inline]
pub fn try_to_u32(self) -> Result<u32, Size> {
self.to_bits(Size::from_bits(32)).map(|v| u32::try_from(v).unwrap())
}
/// Tries to convert the `ScalarInt` to `u64`. Fails if the `size` of the `ScalarInt`
/// in not equal to `Size { raw: 8 }` and returns the `size` value of the `ScalarInt` in
/// that case.
#[inline]
pub fn try_to_u64(self) -> Result<u64, Size> {
self.to_bits(Size::from_bits(64)).map(|v| u64::try_from(v).unwrap())
}
/// Tries to convert the `ScalarInt` to `u128`. Fails if the `size` of the `ScalarInt`
/// in not equal to `Size { raw: 16 }` and returns the `size` value of the `ScalarInt` in
/// that case.
#[inline]
pub fn try_to_u128(self) -> Result<u128, Size> {
self.to_bits(Size::from_bits(128))
}
/// Tries to convert the `ScalarInt` to a signed integer of the given size.
/// Fails if the size of the `ScalarInt` is not equal to `size` and returns the
/// `ScalarInt`s size in that case.
#[inline]
pub fn try_to_int(self, size: Size) -> Result<i128, Size> {
let b = self.to_bits(size)?;
Ok(size.sign_extend(b) as i128)
}
/// Tries to convert the `ScalarInt` to i8.
/// Fails if the size of the `ScalarInt` is not equal to `Size { raw: 1 }`
/// and returns the `ScalarInt`s size in that case.
pub fn try_to_i8(self) -> Result<i8, Size> {
self.try_to_int(Size::from_bits(8)).map(|v| i8::try_from(v).unwrap())
}
/// Tries to convert the `ScalarInt` to i16.
/// Fails if the size of the `ScalarInt` is not equal to `Size { raw: 2 }`
/// and returns the `ScalarInt`s size in that case.
pub fn try_to_i16(self) -> Result<i16, Size> {
self.try_to_int(Size::from_bits(16)).map(|v| i16::try_from(v).unwrap())
}
/// Tries to convert the `ScalarInt` to i32.
/// Fails if the size of the `ScalarInt` is not equal to `Size { raw: 4 }`
/// and returns the `ScalarInt`s size in that case.
pub fn try_to_i32(self) -> Result<i32, Size> {
self.try_to_int(Size::from_bits(32)).map(|v| i32::try_from(v).unwrap())
}
/// Tries to convert the `ScalarInt` to i64.
/// Fails if the size of the `ScalarInt` is not equal to `Size { raw: 8 }`
/// and returns the `ScalarInt`s size in that case.
pub fn try_to_i64(self) -> Result<i64, Size> {
self.try_to_int(Size::from_bits(64)).map(|v| i64::try_from(v).unwrap())
}
/// Tries to convert the `ScalarInt` to i128.
/// Fails if the size of the `ScalarInt` is not equal to `Size { raw: 16 }`
/// and returns the `ScalarInt`s size in that case.
pub fn try_to_i128(self) -> Result<i128, Size> {
self.try_to_int(Size::from_bits(128))
}
}
macro_rules! from {
($($ty:ty),*) => {
$(
impl From<$ty> for ScalarInt {
#[inline]
fn from(u: $ty) -> Self {
Self {
data: u128::from(u),
size: NonZeroU8::new(std::mem::size_of::<$ty>() as u8).unwrap(),
}
}
}
)*
}
}
macro_rules! try_from {
($($ty:ty),*) => {
$(
impl TryFrom<ScalarInt> for $ty {
type Error = Size;
#[inline]
fn try_from(int: ScalarInt) -> Result<Self, Size> {
// The `unwrap` cannot fail because to_bits (if it succeeds)
// is guaranteed to return a value that fits into the size.
int.to_bits(Size::from_bytes(std::mem::size_of::<$ty>()))
.map(|u| u.try_into().unwrap())
}
}
)*
}
}
from!(u8, u16, u32, u64, u128, bool);
try_from!(u8, u16, u32, u64, u128);
impl TryFrom<ScalarInt> for bool {
type Error = Size;
#[inline]
fn try_from(int: ScalarInt) -> Result<Self, Size> {
int.to_bits(Size::from_bytes(1)).and_then(|u| match u {
0 => Ok(false),
1 => Ok(true),
_ => Err(Size::from_bytes(1)),
})
}
}
impl From<char> for ScalarInt {
#[inline]
fn from(c: char) -> Self {
Self { data: c as u128, size: NonZeroU8::new(std::mem::size_of::<char>() as u8).unwrap() }
}
}
/// Error returned when a conversion from ScalarInt to char fails.
#[derive(Debug)]
pub struct CharTryFromScalarInt;
impl TryFrom<ScalarInt> for char {
type Error = CharTryFromScalarInt;
#[inline]
fn try_from(int: ScalarInt) -> Result<Self, Self::Error> {
let Ok(bits) = int.to_bits(Size::from_bytes(std::mem::size_of::<char>())) else {
return Err(CharTryFromScalarInt);
};
match char::from_u32(bits.try_into().unwrap()) {
Some(c) => Ok(c),
None => Err(CharTryFromScalarInt),
}
}
}
impl From<Single> for ScalarInt {
#[inline]
fn from(f: Single) -> Self {
// We trust apfloat to give us properly truncated data.
Self { data: f.to_bits(), size: NonZeroU8::new((Single::BITS / 8) as u8).unwrap() }
}
}
impl TryFrom<ScalarInt> for Single {
type Error = Size;
#[inline]
fn try_from(int: ScalarInt) -> Result<Self, Size> {
int.to_bits(Size::from_bytes(4)).map(Self::from_bits)
}
}
impl From<Double> for ScalarInt {
#[inline]
fn from(f: Double) -> Self {
// We trust apfloat to give us properly truncated data.
Self { data: f.to_bits(), size: NonZeroU8::new((Double::BITS / 8) as u8).unwrap() }
}
}
impl TryFrom<ScalarInt> for Double {
type Error = Size;
#[inline]
fn try_from(int: ScalarInt) -> Result<Self, Size> {
int.to_bits(Size::from_bytes(8)).map(Self::from_bits)
}
}
impl fmt::Debug for ScalarInt {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
// Dispatch to LowerHex below.
write!(f, "0x{self:x}")
}
}
impl fmt::LowerHex for ScalarInt {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.check_data();
if f.alternate() {
// Like regular ints, alternate flag adds leading `0x`.
write!(f, "0x")?;
}
// Format as hex number wide enough to fit any value of the given `size`.
// So data=20, size=1 will be "0x14", but with size=4 it'll be "0x00000014".
// Using a block `{self.data}` here to force a copy instead of using `self.data`
// directly, because `write!` takes references to its formatting arguments and
// would thus borrow `self.data`. Since `Self`
// is a packed struct, that would create a possibly unaligned reference, which
// is UB.
write!(f, "{:01$x}", { self.data }, self.size.get() as usize * 2)
}
}
impl fmt::UpperHex for ScalarInt {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.check_data();
// Format as hex number wide enough to fit any value of the given `size`.
// So data=20, size=1 will be "0x14", but with size=4 it'll be "0x00000014".
// Using a block `{self.data}` here to force a copy instead of using `self.data`
// directly, because `write!` takes references to its formatting arguments and
// would thus borrow `self.data`. Since `Self`
// is a packed struct, that would create a possibly unaligned reference, which
// is UB.
write!(f, "{:01$X}", { self.data }, self.size.get() as usize * 2)
}
}
impl fmt::Display for ScalarInt {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.check_data();
write!(f, "{}", { self.data })
}
}