Merging upstream version 1.71.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

2 files changed, 747 insertions, 0 deletions

diff --git a/vendor/cast/src/lib.rs b/vendor/cast/src/lib.rs
new file mode 100644
index 000000000..f1db3fce7
--- /dev/null
+++ b/vendor/cast/src/lib.rs
@@ -0,0 +1,539 @@
+//! Ergonomic, checked cast functions for primitive types
+//!
+//! This crate provides one checked cast function for each numeric primitive.
+//! Use these functions to perform a cast from any other numeric primitive:
+//!
+//! ```
+//! use cast::{u8, u16, Error};
+//!
+//! # fn main() {
+//! // Infallible operations, like integer promotion, are equivalent to a normal
+//! // cast with `as`
+//! assert_eq!(u16(0u8), 0u16);
+//!
+//! // Everything else will return a `Result` depending on the success of the
+//! // operation
+//! assert_eq!(u8(0u16), Ok(0u8));
+//! assert_eq!(u8(256u16), Err(Error::Overflow));
+//! assert_eq!(u8(-1i8), Err(Error::Underflow));
+//! assert_eq!(u8(1. / 0.), Err(Error::Infinite));
+//! assert_eq!(u8(0. / 0.), Err(Error::NaN));
+//! # }
+//! ```
+//!
+//! There are no namespace problems between these functions, the "primitive
+//! modules" in `core`/`std` and the built-in primitive types, so all them can
+//! be in the same scope:
+//!
+//! ```
+//! use std::u8;
+//! use cast::{u8, u16};
+//!
+//! # fn main() {
+//! // `u8` as a type
+//! let x: u8 = 0;
+//! // `u8` as a module
+//! let y = u16(u8::MAX);
+//! // `u8` as a function
+//! let z = u8(y).unwrap();
+//! # }
+//! ```
+//!
+//! The checked cast functionality is also usable with type aliases via the
+//! `cast` static method:
+//!
+//! ```
+//! use std::os::raw::c_ulonglong;
+//! // NOTE avoid shadowing `std::convert::From` - cf. rust-lang/rfcs#1311
+//! use cast::From as _0;
+//!
+//! # fn main() {
+//! assert_eq!(c_ulonglong::cast(0u8), 0u64);
+//! # }
+//! ```
+//!
+//! This crate also provides a `From` trait that can be used, for example,
+//! to create a generic function that accepts any type that can be infallibly
+//! casted to `u32`.
+//!
+//! ```
+//! fn to_u32<T>(x: T) -> u32
+//!     // reads as: "where u32 can be casted from T with output u32"
+//!     where u32: cast::From<T, Output=u32>,
+//! {
+//!     cast::u32(x)
+//! }
+//!
+//! # fn main() {
+//! assert_eq!(to_u32(0u8), 0u32);
+//! assert_eq!(to_u32(1u16), 1u32);
+//! assert_eq!(to_u32(2u32), 2u32);
+//!
+//! // to_u32(-1i32);  // Compile error
+//! # }
+//! ```
+//!
+//! ## Minimal Supported Rust Version
+//!
+//! This crate is guaranteed to compile *as a dependency* on stable Rust 1.31 and up.
+//! It's not guaranteed that `cargo test`-ing this crate follows the MSRV.
+//! It *might* compile on older versions but that may change in any new patch release.
+//!
+//! ## Building without `std`
+//!
+//! This crate can be used without Rust's `std` crate by declaring it as
+//! follows in your `Cargo.toml`:
+//!
+//! ``` toml
+//! cast = { version = "*", default-features = false }
+//! ```
+
+#![allow(const_err)]
+#![cfg_attr(not(feature = "std"), no_std)]
+#![deny(missing_docs)]
+#![deny(unsafe_code)]
+#![deny(warnings)]
+
+#[cfg(test)]
+#[macro_use]
+extern crate quickcheck;
+
+use core::fmt;
+#[cfg(feature = "std")]
+use std::error;
+
+#[cfg(test)]
+mod test;
+
+/// Cast errors
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum Error {
+    /// Infinite value casted to a type that can only represent finite values
+    Infinite,
+    /// NaN value casted to a type that can't represent a NaN value
+    NaN,
+    /// Source value is greater than the maximum value that the destination type
+    /// can hold
+    Overflow,
+    /// Source value is smaller than the minimum value that the destination type
+    /// can hold
+    Underflow,
+}
+
+impl Error {
+    /// A private helper function that implements `description`, because
+    /// `description` is only available when we have `std` enabled.
+    fn description_helper(&self) -> &str {
+        match *self {
+            Error::Infinite => "Cannot store infinite value in finite type",
+            Error::NaN => "Cannot store NaN in type which does not support it",
+            Error::Overflow => "Overflow during numeric conversion",
+            Error::Underflow => "Underflow during numeric conversion",
+        }
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.description_helper())
+    }
+}
+
+#[cfg(feature = "std")]
+impl error::Error for Error {
+    fn description(&self) -> &str {
+        self.description_helper()
+    }
+}
+
+/// The "cast from" operation
+pub trait From<Src> {
+    /// The result of the cast operation: either `Self` or `Result<Self, Error>`
+    type Output;
+
+    /// Checked cast from `Src` to `Self`
+    fn cast(_: Src) -> Self::Output;
+}
+
+macro_rules! fns {
+    ($($ty:ident),+) => {
+        $(
+            /// Checked cast function
+            #[inline]
+            pub fn $ty<T>(x: T) -> <$ty as From<T>>::Output
+                where $ty: From<T>
+            {
+                <$ty as From<T>>::cast(x)
+            }
+         )+
+    }
+}
+
+fns!(f32, f64, i8, i16, i32, i64, isize, u8, u16, u32, u64, usize);
+
+fns!(i128, u128);
+
+/// `$dst` can hold any value of `$src`
+macro_rules! promotion {
+    ($($src:ty => $($dst: ty),+);+;) => {
+        $(
+            $(
+                impl From<$src> for $dst {
+                    type Output = $dst;
+
+                    #[inline]
+                    fn cast(src: $src) -> $dst {
+                        src as $dst
+                    }
+                }
+            )+
+        )+
+    }
+}
+
+/// `$dst` can hold any positive value of `$src`
+macro_rules! half_promotion {
+    ($($src:ty => $($dst:ty),+);+;) => {
+        $(
+            $(
+                impl From<$src> for $dst {
+                    type Output = Result<$dst, Error>;
+
+                    #[inline]
+                    fn cast(src: $src) -> Self::Output {
+                        if src < 0 {
+                            Err(Error::Underflow)
+                        } else {
+                            Ok(src as $dst)
+                        }
+                    }
+                }
+            )+
+        )+
+    }
+}
+
+/// From an unsigned `$src` to a smaller `$dst`
+macro_rules! from_unsigned {
+    ($($src:ident => $($dst:ident),+);+;) => {
+        $(
+            $(
+                impl From<$src> for $dst {
+                    type Output = Result<$dst, Error>;
+
+                    #[inline]
+                    fn cast(src: $src) -> Self::Output {
+                        use core::$dst;
+
+                        if src > $dst::MAX as $src {
+                            Err(Error::Overflow)
+                        } else {
+                            Ok(src as $dst)
+                        }
+                    }
+                }
+            )+
+        )+
+    }
+}
+
+/// From a signed `$src` to a smaller `$dst`
+macro_rules! from_signed {
+    ($($src:ident => $($dst:ident),+);+;) => {
+        $(
+            $(
+                impl From<$src> for $dst {
+                    type Output = Result<$dst, Error>;
+
+                    #[inline]
+                    fn cast(src: $src) -> Self::Output {
+                        use core::$dst;
+
+                        Err(if src < $dst::MIN as $src {
+                            Error::Underflow
+                        } else if src > $dst::MAX as $src {
+                            Error::Overflow
+                        } else {
+                            return Ok(src as $dst);
+                        })
+                    }
+                }
+            )+
+        )+
+    }
+}
+
+/// From a float `$src` to an integer `$dst`
+macro_rules! from_float {
+    ($($src:ident => $($dst:ident),+);+;) => {
+        $(
+            $(
+                impl From<$src> for $dst {
+                    type Output = Result<$dst, Error>;
+
+                    #[inline]
+                    fn cast(src: $src) -> Self::Output {
+                        use core::{$dst, $src};
+
+                        Err(if src != src {
+                            Error::NaN
+                        } else if src == $src::INFINITY ||
+                            src == $src::NEG_INFINITY {
+                            Error::Infinite
+                        } else if {
+                            // this '$dst::BITS' works on 1.31.0 (MSRV)
+                            let dst_bits = core::mem::size_of::<$dst>() as u32 * 8;
+                            let lossless = dst_bits < core::$src::MANTISSA_DIGITS;
+
+                            let max = if lossless {
+                                $dst::MAX as $src
+                            } else {
+                                // we subtract 1 ULP (unit of least precision) here because some
+                                // lossy conversions like `u64::MAX as f64` round *up* and we want
+                                // to avoid the check below evaluating to false in that case
+                                $src::from_bits(($dst::MAX as $src).to_bits() - 1)
+                            };
+
+                            src > max
+                        } {
+                            Error::Overflow
+                        } else if $dst::MIN == 0 {
+                            // when casting to unsigned integer, negative values close to 0 but
+                            // larger than 1.0 should be truncated to 0; this behavior matches
+                            // casting from a float to a signed integer
+                            if src <= -1.0 {
+                                Error::Underflow
+                            } else {
+                                return Ok(src as $dst);
+                            }
+                        } else if src < $dst::MIN as $src {
+                            Error::Underflow
+                        } else  {
+                            return Ok(src as $dst);
+                        })
+                    }
+                }
+            )+
+        )+
+    }
+}
+
+/// From a float `$src` to an integer `$dst`, where $dst is large enough to contain
+/// all values of `$src`. We can't ever overflow here
+macro_rules! from_float_dst {
+    ($($src:ident => $($dst:ident),+);+;) => {
+        $(
+            $(
+                impl From<$src> for $dst {
+                     type Output = Result<$dst, Error>;
+
+                    #[inline]
+                    #[allow(unused_comparisons)]
+                    fn cast(src: $src) -> Self::Output {
+                        use core::{$dst, $src};
+
+                        Err(if src != src {
+                            Error::NaN
+                        } else if src == $src::INFINITY ||
+                            src == $src::NEG_INFINITY {
+                            Error::Infinite
+                        } else if ($dst::MIN == 0) && src <= -1.0 {
+                            Error::Underflow
+                        } else {
+                            return Ok(src as $dst);
+                        })
+                    }
+                }
+            )+
+        )+
+    }
+}
+
+// PLAY TETRIS! ;-)
+
+#[cfg(target_pointer_width = "32")]
+mod _32 {
+    use crate::{Error, From};
+
+    // Signed
+    promotion! {
+        i8    => f32, f64, i8, i16, i32, isize, i64;
+        i16   => f32, f64,     i16, i32, isize, i64;
+        i32   => f32, f64,          i32, isize, i64;
+        isize => f32, f64,          i32, isize, i64;
+        i64   => f32, f64,                      i64;
+    }
+
+    half_promotion! {
+        i8    =>                                     u8, u16, u32, usize, u64;
+        i16   =>                                         u16, u32, usize, u64;
+        i32   =>                                              u32, usize, u64;
+        isize =>                                              u32, usize, u64;
+        i64   =>                                                          u64;
+    }
+
+    from_signed! {
+
+        i16   =>           i8,                       u8;
+        i32   =>           i8, i16,                  u8, u16;
+        isize =>           i8, i16,                  u8, u16;
+        i64   =>           i8, i16, i32, isize,      u8, u16, u32, usize;
+    }
+
+    // Unsigned
+    promotion! {
+        u8    => f32, f64,     i16, i32, isize, i64, u8, u16, u32, usize, u64;
+        u16   => f32, f64,          i32, isize, i64,     u16, u32, usize, u64;
+        u32   => f32, f64,                      i64,          u32, usize, u64;
+        usize => f32, f64,                      i64,          u32, usize, u64;
+        u64   => f32, f64,                                                u64;
+    }
+
+    from_unsigned! {
+        u8    =>           i8;
+        u16   =>           i8, i16,                  u8;
+        u32   =>           i8, i16, i32, isize,      u8, u16;
+        usize =>           i8, i16, i32, isize,      u8, u16;
+        u64   =>           i8, i16, i32, isize, i64, u8, u16, u32, usize;
+    }
+
+    // Float
+    promotion! {
+        f32   => f32, f64;
+        f64   =>      f64;
+    }
+
+    from_float! {
+        f32 =>             i8, i16, i32, isize, i64, u8, u16, u32, usize, u64;
+        f64 =>             i8, i16, i32, isize, i64, u8, u16, u32, usize, u64;
+    }
+}
+
+#[cfg(target_pointer_width = "64")]
+mod _64 {
+    use crate::{Error, From};
+
+    // Signed
+    promotion! {
+        i8    => f32, f64, i8, i16, i32, i64, isize;
+        i16   => f32, f64,     i16, i32, i64, isize;
+        i32   => f32, f64,          i32, i64, isize;
+        i64   => f32, f64,               i64, isize;
+        isize => f32, f64,               i64, isize;
+    }
+
+    half_promotion! {
+        i8    =>                                     u8, u16, u32, u64, usize;
+        i16   =>                                         u16, u32, u64, usize;
+        i32   =>                                              u32, u64, usize;
+        i64   =>                                                   u64, usize;
+        isize =>                                                   u64, usize;
+    }
+
+    from_signed! {
+
+        i16   =>           i8,                       u8;
+        i32   =>           i8, i16,                  u8, u16;
+        i64   =>           i8, i16, i32,             u8, u16, u32;
+        isize =>           i8, i16, i32,             u8, u16, u32;
+    }
+
+    // Unsigned
+    promotion! {
+        u8    => f32, f64,     i16, i32, i64, isize, u8, u16, u32, u64, usize;
+        u16   => f32, f64,          i32, i64, isize,     u16, u32, u64, usize;
+        u32   => f32, f64,               i64, isize,          u32, u64, usize;
+        u64   => f32, f64,                                         u64, usize;
+        usize => f32, f64,                                         u64, usize;
+    }
+
+    from_unsigned! {
+        u8    =>           i8;
+        u16   =>           i8, i16,                  u8;
+        u32   =>           i8, i16, i32,             u8, u16;
+        u64   =>           i8, i16, i32, i64, isize, u8, u16, u32;
+        usize =>           i8, i16, i32, i64, isize, u8, u16, u32;
+    }
+
+    // Float
+    promotion! {
+        f32  => f32, f64;
+        f64  =>      f64;
+    }
+
+    from_float! {
+        f32 =>             i8, i16, i32, i64, isize, u8, u16, u32, u64, usize;
+        f64 =>             i8, i16, i32, i64, isize, u8, u16, u32, u64, usize;
+    }
+}
+
+mod _x128 {
+    use crate::{Error, From};
+
+    // Signed
+    promotion! {
+        i8    =>                              i128;
+        i16   =>                              i128;
+        i32   =>                              i128;
+        i64   =>                              i128;
+        isize =>                              i128;
+        i128  => f32, f64,                    i128;
+    }
+
+    half_promotion! {
+        i8    =>                                                              u128;
+        i16   =>                                                              u128;
+        i32   =>                                                              u128;
+        i64   =>                                                              u128;
+        isize =>                                                              u128;
+        i128  =>                                                              u128;
+    }
+
+    from_signed! {
+        i128  =>           i8, i16, i32, i64,       isize, u8, u16, u32, u64,       usize;
+    }
+
+    // Unsigned
+    promotion! {
+        u8    =>                              i128,                           u128;
+        u16   =>                              i128,                           u128;
+        u32   =>                              i128,                           u128;
+        u64   =>                              i128,                           u128;
+        usize =>                              i128,                           u128;
+        u128  =>      f64,                                                    u128;
+    }
+
+    from_unsigned! {
+        u128 => f32,       i8, i16, i32, i64, i128, isize, u8, u16, u32, u64,       usize;
+    }
+
+    // Float
+    from_float_dst! {
+        f32 =>                                                                u128;
+    }
+
+    from_float! {
+        f32 =>                                i128;
+        f64 =>                                i128,                           u128;
+    }
+}
+
+// The missing piece
+impl From<f64> for f32 {
+    type Output = Result<f32, Error>;
+
+    #[inline]
+    fn cast(src: f64) -> Self::Output {
+        use core::{f32, f64};
+
+        if src != src || src == f64::INFINITY || src == f64::NEG_INFINITY {
+            Ok(src as f32)
+        } else if src < f32::MIN as f64 {
+            Err(Error::Underflow)
+        } else if src > f32::MAX as f64 {
+            Err(Error::Overflow)
+        } else {
+            Ok(src as f32)
+        }
+    }
+}
diff --git a/vendor/cast/src/test.rs b/vendor/cast/src/test.rs
new file mode 100644
index 000000000..161a0220e
--- /dev/null
+++ b/vendor/cast/src/test.rs
@@ -0,0 +1,208 @@
+// If `src` can be promoted to `$dst`, then it must be Ok to cast `dst` back to
+// `$src`
+macro_rules! promote_and_back {
+    ($($src:ident => $($dst:ident),+);+;) => {
+        mod demoting_to {
+            $(
+                mod $src {
+                    mod from {
+                        use crate::From;
+
+                        $(
+                            quickcheck! {
+                                fn $dst(src: $src) -> bool {
+                                    $src::cast($dst::cast(src)).is_ok()
+                                }
+                            }
+                         )+
+                    }
+                }
+             )+
+        }
+    }
+}
+
+#[cfg(target_pointer_width = "32")]
+promote_and_back! {
+    i8    => f32, f64,     i16, i32, isize, i64, i128                            ;
+    i16   => f32, f64,          i32, isize, i64, i128                            ;
+    i32   =>      f64,                      i64, i128                            ;
+    isize =>      f64,                      i64, i128                            ;
+    i64   =>                                     i128                            ;
+    u8    => f32, f64,     i16, i32, isize, i64, i128, u16, u32, usize, u64, u128;
+    u16   => f32, f64,          i32, isize, i64, i128,      u32, usize, u64, u128;
+    u32   =>      f64,                      i64, i128,                  u64, u128;
+    usize =>      f64,                      i64, i128,                  u64, u128;
+    u64   =>                                     i128,                       u128;
+}
+
+#[cfg(target_pointer_width = "64")]
+promote_and_back! {
+    i8    => f32, f64,     i16, i32, i64, isize, i128                            ;
+    i16   => f32, f64,          i32, i64, isize, i128                            ;
+    i32   =>      f64,               i64, isize, i128                            ;
+    i64   =>                                     i128                            ;
+    isize =>                                     i128                            ;
+    u8    => f32, f64,     i16, i32, i64, isize, i128, u16, u32, u64, usize, u128;
+    u16   => f32, f64,          i32, i64, isize, i128,      u32, u64, usize, u128;
+    u32   =>      f64,               i64, isize, i128,           u64, usize, u128;
+    u64   =>                                     i128,                       u128;
+    usize =>                                     i128,                       u128;
+}
+
+// If it's Ok to cast `src` to `$dst`, it must also be Ok to cast `dst` back to
+// `$src`
+macro_rules! symmetric_cast_between {
+    ($($src:ident => $($dst:ident),+);+;) => {
+        mod symmetric_cast_between {
+            $(
+                mod $src {
+                    mod and {
+                        use quickcheck::TestResult;
+
+                        use crate::From;
+
+                        $(
+                            quickcheck! {
+                                fn $dst(src: $src) -> TestResult {
+                                    if let Ok(dst) = $dst::cast(src) {
+                                        TestResult::from_bool(
+                                            $src::cast(dst).is_ok())
+                                    } else {
+                                        TestResult::discard()
+                                    }
+                                }
+                            }
+                         )+
+                    }
+                }
+             )+
+        }
+    }
+}
+
+#[cfg(target_pointer_width = "32")]
+symmetric_cast_between! {
+    u8    =>           i8                      ;
+    u16   =>           i8, i16                 ;
+    u32   =>           i8, i16, i32            ;
+    usize =>           i8, i16, i32            ;
+    u64   =>           i8, i16, i32, i64, isize;
+}
+
+#[cfg(target_pointer_width = "64")]
+symmetric_cast_between! {
+    u8    =>           i8                            ;
+    u16   =>           i8, i16                       ;
+    u32   =>           i8, i16, i32                  ;
+    u64   =>           i8, i16, i32, i64, isize      ;
+    usize =>           i8, i16, i32, i64, isize      ;
+    u128  =>           i8, i16, i32, i64, isize, i128;
+}
+
+macro_rules! from_float {
+    ($($src:ident => $($dst:ident),+);+;) => {
+        $(
+            mod $src {
+                mod inf {
+                    mod to {
+                        use crate::{Error, From};
+
+                        $(
+                            #[test]
+                            fn $dst() {
+                                let _0: $src = 0.;
+                                let _1: $src = 1.;
+                                let inf = _1 / _0;
+                                let neg_inf = -_1 / _0;
+
+                                assert_eq!($dst::cast(inf),
+                                           Err(Error::Infinite));
+                                assert_eq!($dst::cast(neg_inf),
+                                           Err(Error::Infinite));
+                            }
+                         )+
+                    }
+                }
+
+                mod nan {
+                    mod to {
+                        use crate::{Error, From};
+
+                        $(
+                            #[test]
+                            fn $dst() {
+                                let _0: $src = 0.;
+                                let nan = _0 / _0;
+
+                                assert_eq!($dst::cast(nan),
+                                           Err(Error::NaN));
+                            }
+                         )+
+                    }
+                }
+            }
+         )+
+    }
+}
+
+from_float! {
+    f32 => i8, i16, i32, i64, i128, isize, u8, u16, u32, u64, u128, usize;
+    f64 => i8, i16, i32, i64, i128, isize, u8, u16, u32, u64, u128, usize;
+}
+
+#[test]
+fn test_fl_conversion() {
+    use crate::u128;
+    assert_eq!(u128(42.0f32), Ok(42));
+}
+
+#[test]
+fn gh16() {
+    assert_eq!(super::u64(-0.01_f64), Ok(0));
+    assert_eq!(super::u64(-0.99_f32), Ok(0));
+
+    assert_eq!(super::u32(-0.99_f64), Ok(0));
+    assert_eq!(super::u32(-0.01_f32), Ok(0));
+
+    assert_eq!(super::u64(0.01_f64), Ok(0));
+    assert_eq!(super::u64(0.99_f32), Ok(0));
+
+    assert_eq!(super::u32(0.99_f64), Ok(0));
+    assert_eq!(super::u32(0.01_f32), Ok(0));
+}
+
+#[test]
+fn gh15() {
+    assert_eq!(super::u32(32_f32.exp2()), Err(super::Error::Overflow));
+    assert_eq!(super::u32(32_f64.exp2()), Err(super::Error::Overflow));
+
+    assert_eq!(super::u64(64_f32.exp2()), Err(super::Error::Overflow));
+    assert_eq!(super::u64(64_f64.exp2()), Err(super::Error::Overflow));
+
+    assert_eq!(super::u8(8_f32.exp2()), Err(super::Error::Overflow));
+    assert_eq!(super::u8(8_f64.exp2()), Err(super::Error::Overflow));
+
+    assert_eq!(super::u16(16_f32.exp2()), Err(super::Error::Overflow));
+    assert_eq!(super::u16(16_f64.exp2()), Err(super::Error::Overflow));
+}
+
+#[test]
+fn gh23_lossless_integer_max_min_to_float() {
+    // f32::MANTISSA_DIGITS = 24
+    assert_eq!(Ok(u8::MAX), super::u8(255f32));
+    assert_eq!(Ok(u16::MAX), super::u16(65_535f32));
+
+    // f64::MANTISSA_DIGITS = 53
+    assert_eq!(Ok(u8::MAX), super::u8(255f64));
+    assert_eq!(Ok(u16::MAX), super::u16(65_535f64));
+    assert_eq!(Ok(u32::MAX), super::u32(4_294_967_295f64));
+
+    // also check negative values (not part of the original bug)
+    assert_eq!(Ok(i8::MIN), super::i8(-128f32));
+    assert_eq!(Ok(i16::MIN), super::i16(-32_768f32));
+
+    assert_eq!(Ok(i8::MIN), super::i8(-128f64));
+    assert_eq!(Ok(i16::MIN), super::i16(-32_768f64));
+    assert_eq!(Ok(i32::MIN), super::i32(-2_147_483_648f64));
+}