1 files changed, 283 insertions, 0 deletions
diff --git a/vendor/gimli/src/read/util.rs b/vendor/gimli/src/read/util.rs
new file mode 100644
index 0000000..041ca5a
--- /dev/null
+++ b/vendor/gimli/src/read/util.rs
@@ -0,0 +1,283 @@
+#[cfg(feature = "read")]
+use alloc::boxed::Box;
+#[cfg(feature = "read")]
+use alloc::vec::Vec;
+use core::fmt;
+use core::mem::MaybeUninit;
+use core::ops;
+use core::ptr;
+use core::slice;
+
+mod sealed {
+    /// # Safety
+    /// Implementer must not modify the content in storage.
+    pub unsafe trait Sealed {
+        type Storage;
+
+        fn new_storage() -> Self::Storage;
+
+        fn grow(_storage: &mut Self::Storage, _additional: usize) -> Result<(), CapacityFull> {
+            Err(CapacityFull)
+        }
+    }
+
+    #[derive(Clone, Copy, Debug)]
+    pub struct CapacityFull;
+}
+
+use sealed::*;
+
+/// Marker trait for types that can be used as backing storage when a growable array type is needed.
+///
+/// This trait is sealed and cannot be implemented for types outside this crate.
+pub trait ArrayLike: Sealed {
+    /// Type of the elements being stored.
+    type Item;
+
+    #[doc(hidden)]
+    fn as_slice(storage: &Self::Storage) -> &[MaybeUninit<Self::Item>];
+
+    #[doc(hidden)]
+    fn as_mut_slice(storage: &mut Self::Storage) -> &mut [MaybeUninit<Self::Item>];
+}
+
+// Use macro since const generics can't be used due to MSRV.
+macro_rules! impl_array {
+    () => {};
+    ($n:literal $($rest:tt)*) => {
+        // SAFETY: does not modify the content in storage.
+        unsafe impl<T> Sealed for [T; $n] {
+            type Storage = [MaybeUninit<T>; $n];
+
+            fn new_storage() -> Self::Storage {
+                // SAFETY: An uninitialized `[MaybeUninit<_>; _]` is valid.
+                unsafe { MaybeUninit::uninit().assume_init() }
+            }
+        }
+
+        impl<T> ArrayLike for [T; $n] {
+            type Item = T;
+
+            fn as_slice(storage: &Self::Storage) -> &[MaybeUninit<T>] {
+                storage
+            }
+
+            fn as_mut_slice(storage: &mut Self::Storage) -> &mut [MaybeUninit<T>] {
+                storage
+            }
+        }
+
+        impl_array!($($rest)*);
+    }
+}
+
+#[cfg(feature = "read")]
+macro_rules! impl_box {
+    () => {};
+    ($n:literal $($rest:tt)*) => {
+        // SAFETY: does not modify the content in storage.
+        unsafe impl<T> Sealed for Box<[T; $n]> {
+            type Storage = Box<[MaybeUninit<T>; $n]>;
+
+            fn new_storage() -> Self::Storage {
+                // SAFETY: An uninitialized `[MaybeUninit<_>; _]` is valid.
+                Box::new(unsafe { MaybeUninit::uninit().assume_init() })
+            }
+        }
+
+        impl<T> ArrayLike for Box<[T; $n]> {
+            type Item = T;
+
+            fn as_slice(storage: &Self::Storage) -> &[MaybeUninit<T>] {
+                &storage[..]
+            }
+
+            fn as_mut_slice(storage: &mut Self::Storage) -> &mut [MaybeUninit<T>] {
+                &mut storage[..]
+            }
+        }
+
+        impl_box!($($rest)*);
+    }
+}
+
+impl_array!(0 1 2 3 4 8 16 32 64 128 192);
+#[cfg(feature = "read")]
+impl_box!(0 1 2 3 4 8 16 32 64 128 192);
+
+#[cfg(feature = "read")]
+unsafe impl<T> Sealed for Vec<T> {
+    type Storage = Box<[MaybeUninit<T>]>;
+
+    fn new_storage() -> Self::Storage {
+        Box::new([])
+    }
+
+    fn grow(storage: &mut Self::Storage, additional: usize) -> Result<(), CapacityFull> {
+        let mut vec: Vec<_> = core::mem::replace(storage, Box::new([])).into();
+        vec.reserve(additional);
+        // SAFETY: This is a `Vec` of `MaybeUninit`.
+        unsafe { vec.set_len(vec.capacity()) };
+        *storage = vec.into_boxed_slice();
+        Ok(())
+    }
+}
+
+#[cfg(feature = "read")]
+impl<T> ArrayLike for Vec<T> {
+    type Item = T;
+
+    fn as_slice(storage: &Self::Storage) -> &[MaybeUninit<T>] {
+        storage
+    }
+
+    fn as_mut_slice(storage: &mut Self::Storage) -> &mut [MaybeUninit<T>] {
+        storage
+    }
+}
+
+pub(crate) struct ArrayVec<A: ArrayLike> {
+    storage: A::Storage,
+    len: usize,
+}
+
+impl<A: ArrayLike> ArrayVec<A> {
+    pub fn new() -> Self {
+        Self {
+            storage: A::new_storage(),
+            len: 0,
+        }
+    }
+
+    pub fn clear(&mut self) {
+        let ptr: *mut [A::Item] = &mut **self;
+        // Set length first so the type invariant is upheld even if `drop_in_place` panicks.
+        self.len = 0;
+        // SAFETY: `ptr` contains valid elements only and we "forget" them by setting the length.
+        unsafe { ptr::drop_in_place(ptr) };
+    }
+
+    pub fn try_push(&mut self, value: A::Item) -> Result<(), CapacityFull> {
+        let mut storage = A::as_mut_slice(&mut self.storage);
+        if self.len >= storage.len() {
+            A::grow(&mut self.storage, 1)?;
+            storage = A::as_mut_slice(&mut self.storage);
+        }
+
+        storage[self.len] = MaybeUninit::new(value);
+        self.len += 1;
+        Ok(())
+    }
+
+    pub fn try_insert(&mut self, index: usize, element: A::Item) -> Result<(), CapacityFull> {
+        assert!(index <= self.len);
+
+        let mut storage = A::as_mut_slice(&mut self.storage);
+        if self.len >= storage.len() {
+            A::grow(&mut self.storage, 1)?;
+            storage = A::as_mut_slice(&mut self.storage);
+        }
+
+        // SAFETY: storage[index] is filled later.
+        unsafe {
+            let p = storage.as_mut_ptr().add(index);
+            core::ptr::copy(p as *const _, p.add(1), self.len - index);
+        }
+        storage[index] = MaybeUninit::new(element);
+        self.len += 1;
+        Ok(())
+    }
+
+    pub fn pop(&mut self) -> Option<A::Item> {
+        if self.len == 0 {
+            None
+        } else {
+            self.len -= 1;
+            // SAFETY: this element is valid and we "forget" it by setting the length.
+            Some(unsafe { A::as_slice(&self.storage)[self.len].as_ptr().read() })
+        }
+    }
+
+    pub fn swap_remove(&mut self, index: usize) -> A::Item {
+        assert!(self.len > 0);
+        A::as_mut_slice(&mut self.storage).swap(index, self.len - 1);
+        self.pop().unwrap()
+    }
+}
+
+#[cfg(feature = "read")]
+impl<T> ArrayVec<Vec<T>> {
+    pub fn into_vec(mut self) -> Vec<T> {
+        let len = core::mem::replace(&mut self.len, 0);
+        let storage = core::mem::replace(&mut self.storage, Box::new([]));
+        let slice = Box::leak(storage);
+        debug_assert!(len <= slice.len());
+        // SAFETY: valid elements.
+        unsafe { Vec::from_raw_parts(slice.as_mut_ptr() as *mut T, len, slice.len()) }
+    }
+}
+
+impl<A: ArrayLike> Drop for ArrayVec<A> {
+    fn drop(&mut self) {
+        self.clear();
+    }
+}
+
+impl<A: ArrayLike> Default for ArrayVec<A> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl<A: ArrayLike> ops::Deref for ArrayVec<A> {
+    type Target = [A::Item];
+
+    fn deref(&self) -> &[A::Item] {
+        let slice = &A::as_slice(&self.storage);
+        debug_assert!(self.len <= slice.len());
+        // SAFETY: valid elements.
+        unsafe { slice::from_raw_parts(slice.as_ptr() as _, self.len) }
+    }
+}
+
+impl<A: ArrayLike> ops::DerefMut for ArrayVec<A> {
+    fn deref_mut(&mut self) -> &mut [A::Item] {
+        let slice = &mut A::as_mut_slice(&mut self.storage);
+        debug_assert!(self.len <= slice.len());
+        // SAFETY: valid elements.
+        unsafe { slice::from_raw_parts_mut(slice.as_mut_ptr() as _, self.len) }
+    }
+}
+
+impl<A: ArrayLike> Clone for ArrayVec<A>
+where
+    A::Item: Clone,
+{
+    fn clone(&self) -> Self {
+        let mut new = Self::default();
+        for value in &**self {
+            new.try_push(value.clone()).unwrap();
+        }
+        new
+    }
+}
+
+impl<A: ArrayLike> PartialEq for ArrayVec<A>
+where
+    A::Item: PartialEq,
+{
+    fn eq(&self, other: &Self) -> bool {
+        **self == **other
+    }
+}
+
+impl<A: ArrayLike> Eq for ArrayVec<A> where A::Item: Eq {}
+
+impl<A: ArrayLike> fmt::Debug for ArrayVec<A>
+where
+    A::Item: fmt::Debug,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(&**self, f)
+    }
+}