1 files changed, 502 insertions, 0 deletions
diff --git a/vendor/gimli/src/read/reader.rs b/vendor/gimli/src/read/reader.rs
new file mode 100644
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+++ b/vendor/gimli/src/read/reader.rs
@@ -0,0 +1,502 @@
+#[cfg(feature = "read")]
+use alloc::borrow::Cow;
+use core::convert::TryInto;
+use core::fmt::Debug;
+use core::hash::Hash;
+use core::ops::{Add, AddAssign, Sub};
+
+use crate::common::Format;
+use crate::endianity::Endianity;
+use crate::leb128;
+use crate::read::{Error, Result};
+
+/// An identifier for an offset within a section reader.
+///
+/// This is used for error reporting. The meaning of this value is specific to
+/// each reader implementation. The values should be chosen to be unique amongst
+/// all readers. If values are not unique then errors may point to the wrong reader.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct ReaderOffsetId(pub u64);
+
+/// A trait for offsets with a DWARF section.
+///
+/// This allows consumers to choose a size that is appropriate for their address space.
+pub trait ReaderOffset:
+    Debug + Copy + Eq + Ord + Hash + Add<Output = Self> + AddAssign + Sub<Output = Self>
+{
+    /// Convert a u8 to an offset.
+    fn from_u8(offset: u8) -> Self;
+
+    /// Convert a u16 to an offset.
+    fn from_u16(offset: u16) -> Self;
+
+    /// Convert an i16 to an offset.
+    fn from_i16(offset: i16) -> Self;
+
+    /// Convert a u32 to an offset.
+    fn from_u32(offset: u32) -> Self;
+
+    /// Convert a u64 to an offset.
+    ///
+    /// Returns `Error::UnsupportedOffset` if the value is too large.
+    fn from_u64(offset: u64) -> Result<Self>;
+
+    /// Convert an offset to a u64.
+    fn into_u64(self) -> u64;
+
+    /// Wrapping (modular) addition. Computes `self + other`.
+    fn wrapping_add(self, other: Self) -> Self;
+
+    /// Checked subtraction. Computes `self - other`.
+    fn checked_sub(self, other: Self) -> Option<Self>;
+}
+
+impl ReaderOffset for u64 {
+    #[inline]
+    fn from_u8(offset: u8) -> Self {
+        u64::from(offset)
+    }
+
+    #[inline]
+    fn from_u16(offset: u16) -> Self {
+        u64::from(offset)
+    }
+
+    #[inline]
+    fn from_i16(offset: i16) -> Self {
+        offset as u64
+    }
+
+    #[inline]
+    fn from_u32(offset: u32) -> Self {
+        u64::from(offset)
+    }
+
+    #[inline]
+    fn from_u64(offset: u64) -> Result<Self> {
+        Ok(offset)
+    }
+
+    #[inline]
+    fn into_u64(self) -> u64 {
+        self
+    }
+
+    #[inline]
+    fn wrapping_add(self, other: Self) -> Self {
+        self.wrapping_add(other)
+    }
+
+    #[inline]
+    fn checked_sub(self, other: Self) -> Option<Self> {
+        self.checked_sub(other)
+    }
+}
+
+impl ReaderOffset for u32 {
+    #[inline]
+    fn from_u8(offset: u8) -> Self {
+        u32::from(offset)
+    }
+
+    #[inline]
+    fn from_u16(offset: u16) -> Self {
+        u32::from(offset)
+    }
+
+    #[inline]
+    fn from_i16(offset: i16) -> Self {
+        offset as u32
+    }
+
+    #[inline]
+    fn from_u32(offset: u32) -> Self {
+        offset
+    }
+
+    #[inline]
+    fn from_u64(offset64: u64) -> Result<Self> {
+        let offset = offset64 as u32;
+        if u64::from(offset) == offset64 {
+            Ok(offset)
+        } else {
+            Err(Error::UnsupportedOffset)
+        }
+    }
+
+    #[inline]
+    fn into_u64(self) -> u64 {
+        u64::from(self)
+    }
+
+    #[inline]
+    fn wrapping_add(self, other: Self) -> Self {
+        self.wrapping_add(other)
+    }
+
+    #[inline]
+    fn checked_sub(self, other: Self) -> Option<Self> {
+        self.checked_sub(other)
+    }
+}
+
+impl ReaderOffset for usize {
+    #[inline]
+    fn from_u8(offset: u8) -> Self {
+        offset as usize
+    }
+
+    #[inline]
+    fn from_u16(offset: u16) -> Self {
+        offset as usize
+    }
+
+    #[inline]
+    fn from_i16(offset: i16) -> Self {
+        offset as usize
+    }
+
+    #[inline]
+    fn from_u32(offset: u32) -> Self {
+        offset as usize
+    }
+
+    #[inline]
+    fn from_u64(offset64: u64) -> Result<Self> {
+        let offset = offset64 as usize;
+        if offset as u64 == offset64 {
+            Ok(offset)
+        } else {
+            Err(Error::UnsupportedOffset)
+        }
+    }
+
+    #[inline]
+    fn into_u64(self) -> u64 {
+        self as u64
+    }
+
+    #[inline]
+    fn wrapping_add(self, other: Self) -> Self {
+        self.wrapping_add(other)
+    }
+
+    #[inline]
+    fn checked_sub(self, other: Self) -> Option<Self> {
+        self.checked_sub(other)
+    }
+}
+
+#[cfg(not(feature = "read"))]
+pub(crate) mod seal_if_no_alloc {
+    #[derive(Debug)]
+    pub struct Sealed;
+}
+
+/// A trait for reading the data from a DWARF section.
+///
+/// All read operations advance the section offset of the reader
+/// unless specified otherwise.
+///
+/// ## Choosing a `Reader` Implementation
+///
+/// `gimli` comes with a few different `Reader` implementations and lets you
+/// choose the one that is right for your use case. A `Reader` is essentially a
+/// view into the raw bytes that make up some DWARF, but this view might borrow
+/// the underlying data or use reference counting ownership, and it might be
+/// thread safe or not.
+///
+/// | Implementation    | Ownership         | Thread Safe | Notes |
+/// |:------------------|:------------------|:------------|:------|
+/// | [`EndianSlice`](./struct.EndianSlice.html)        | Borrowed          | Yes         | Fastest, but requires that all of your code work with borrows. |
+/// | [`EndianRcSlice`](./struct.EndianRcSlice.html)    | Reference counted | No          | Shared ownership via reference counting, which alleviates the borrow restrictions of `EndianSlice` but imposes reference counting increments and decrements. Cannot be sent across threads, because the reference count is not atomic. |
+/// | [`EndianArcSlice`](./struct.EndianArcSlice.html)  | Reference counted | Yes         | The same as `EndianRcSlice`, but uses atomic reference counting, and therefore reference counting operations are slower but `EndianArcSlice`s may be sent across threads. |
+/// | [`EndianReader<T>`](./struct.EndianReader.html)   | Same as `T`       | Same as `T` | Escape hatch for easily defining your own type of `Reader`. |
+pub trait Reader: Debug + Clone {
+    /// The endianity of bytes that are read.
+    type Endian: Endianity;
+
+    /// The type used for offsets and lengths.
+    type Offset: ReaderOffset;
+
+    /// Return the endianity of bytes that are read.
+    fn endian(&self) -> Self::Endian;
+
+    /// Return the number of bytes remaining.
+    fn len(&self) -> Self::Offset;
+
+    /// Set the number of bytes remaining to zero.
+    fn empty(&mut self);
+
+    /// Set the number of bytes remaining to the specified length.
+    fn truncate(&mut self, len: Self::Offset) -> Result<()>;
+
+    /// Return the offset of this reader's data relative to the start of
+    /// the given base reader's data.
+    ///
+    /// May panic if this reader's data is not contained within the given
+    /// base reader's data.
+    fn offset_from(&self, base: &Self) -> Self::Offset;
+
+    /// Return an identifier for the current reader offset.
+    fn offset_id(&self) -> ReaderOffsetId;
+
+    /// Return the offset corresponding to the given `id` if
+    /// it is associated with this reader.
+    fn lookup_offset_id(&self, id: ReaderOffsetId) -> Option<Self::Offset>;
+
+    /// Find the index of the first occurrence of the given byte.
+    /// The offset of the reader is not changed.
+    fn find(&self, byte: u8) -> Result<Self::Offset>;
+
+    /// Discard the specified number of bytes.
+    fn skip(&mut self, len: Self::Offset) -> Result<()>;
+
+    /// Split a reader in two.
+    ///
+    /// A new reader is returned that can be used to read the next
+    /// `len` bytes, and `self` is advanced so that it reads the remainder.
+    fn split(&mut self, len: Self::Offset) -> Result<Self>;
+
+    /// This trait cannot be implemented if "read" feature is not enabled.
+    ///
+    /// `Reader` trait has a few methods that depend on `alloc` crate.
+    /// Disallowing `Reader` trait implementation prevents a crate that only depends on
+    /// "read-core" from being broken if another crate depending on `gimli` enables
+    /// "read" feature.
+    #[cfg(not(feature = "read"))]
+    fn cannot_implement() -> seal_if_no_alloc::Sealed;
+
+    /// Return all remaining data as a clone-on-write slice.
+    ///
+    /// The slice will be borrowed where possible, but some readers may
+    /// always return an owned vector.
+    ///
+    /// Does not advance the reader.
+    #[cfg(feature = "read")]
+    fn to_slice(&self) -> Result<Cow<[u8]>>;
+
+    /// Convert all remaining data to a clone-on-write string.
+    ///
+    /// The string will be borrowed where possible, but some readers may
+    /// always return an owned string.
+    ///
+    /// Does not advance the reader.
+    ///
+    /// Returns an error if the data contains invalid characters.
+    #[cfg(feature = "read")]
+    fn to_string(&self) -> Result<Cow<str>>;
+
+    /// Convert all remaining data to a clone-on-write string, including invalid characters.
+    ///
+    /// The string will be borrowed where possible, but some readers may
+    /// always return an owned string.
+    ///
+    /// Does not advance the reader.
+    #[cfg(feature = "read")]
+    fn to_string_lossy(&self) -> Result<Cow<str>>;
+
+    /// Read exactly `buf.len()` bytes into `buf`.
+    fn read_slice(&mut self, buf: &mut [u8]) -> Result<()>;
+
+    /// Read a u8 array.
+    #[inline]
+    fn read_u8_array<A>(&mut self) -> Result<A>
+    where
+        A: Sized + Default + AsMut<[u8]>,
+    {
+        let mut val = Default::default();
+        self.read_slice(<A as AsMut<[u8]>>::as_mut(&mut val))?;
+        Ok(val)
+    }
+
+    /// Return true if the number of bytes remaining is zero.
+    #[inline]
+    fn is_empty(&self) -> bool {
+        self.len() == Self::Offset::from_u8(0)
+    }
+
+    /// Read a u8.
+    #[inline]
+    fn read_u8(&mut self) -> Result<u8> {
+        let a: [u8; 1] = self.read_u8_array()?;
+        Ok(a[0])
+    }
+
+    /// Read an i8.
+    #[inline]
+    fn read_i8(&mut self) -> Result<i8> {
+        let a: [u8; 1] = self.read_u8_array()?;
+        Ok(a[0] as i8)
+    }
+
+    /// Read a u16.
+    #[inline]
+    fn read_u16(&mut self) -> Result<u16> {
+        let a: [u8; 2] = self.read_u8_array()?;
+        Ok(self.endian().read_u16(&a))
+    }
+
+    /// Read an i16.
+    #[inline]
+    fn read_i16(&mut self) -> Result<i16> {
+        let a: [u8; 2] = self.read_u8_array()?;
+        Ok(self.endian().read_i16(&a))
+    }
+
+    /// Read a u32.
+    #[inline]
+    fn read_u32(&mut self) -> Result<u32> {
+        let a: [u8; 4] = self.read_u8_array()?;
+        Ok(self.endian().read_u32(&a))
+    }
+
+    /// Read an i32.
+    #[inline]
+    fn read_i32(&mut self) -> Result<i32> {
+        let a: [u8; 4] = self.read_u8_array()?;
+        Ok(self.endian().read_i32(&a))
+    }
+
+    /// Read a u64.
+    #[inline]
+    fn read_u64(&mut self) -> Result<u64> {
+        let a: [u8; 8] = self.read_u8_array()?;
+        Ok(self.endian().read_u64(&a))
+    }
+
+    /// Read an i64.
+    #[inline]
+    fn read_i64(&mut self) -> Result<i64> {
+        let a: [u8; 8] = self.read_u8_array()?;
+        Ok(self.endian().read_i64(&a))
+    }
+
+    /// Read a f32.
+    #[inline]
+    fn read_f32(&mut self) -> Result<f32> {
+        let a: [u8; 4] = self.read_u8_array()?;
+        Ok(self.endian().read_f32(&a))
+    }
+
+    /// Read a f64.
+    #[inline]
+    fn read_f64(&mut self) -> Result<f64> {
+        let a: [u8; 8] = self.read_u8_array()?;
+        Ok(self.endian().read_f64(&a))
+    }
+
+    /// Read an unsigned n-bytes integer u64.
+    ///
+    /// # Panics
+    ///
+    /// Panics when nbytes < 1 or nbytes > 8
+    #[inline]
+    fn read_uint(&mut self, n: usize) -> Result<u64> {
+        let mut buf = [0; 8];
+        self.read_slice(&mut buf[..n])?;
+        Ok(self.endian().read_uint(&buf[..n]))
+    }
+
+    /// Read a null-terminated slice, and return it (excluding the null).
+    fn read_null_terminated_slice(&mut self) -> Result<Self> {
+        let idx = self.find(0)?;
+        let val = self.split(idx)?;
+        self.skip(Self::Offset::from_u8(1))?;
+        Ok(val)
+    }
+
+    /// Skip a LEB128 encoded integer.
+    fn skip_leb128(&mut self) -> Result<()> {
+        leb128::read::skip(self)
+    }
+
+    /// Read an unsigned LEB128 encoded integer.
+    fn read_uleb128(&mut self) -> Result<u64> {
+        leb128::read::unsigned(self)
+    }
+
+    /// Read an unsigned LEB128 encoded u32.
+    fn read_uleb128_u32(&mut self) -> Result<u32> {
+        leb128::read::unsigned(self)?
+            .try_into()
+            .map_err(|_| Error::BadUnsignedLeb128)
+    }
+
+    /// Read an unsigned LEB128 encoded u16.
+    fn read_uleb128_u16(&mut self) -> Result<u16> {
+        leb128::read::u16(self)
+    }
+
+    /// Read a signed LEB128 encoded integer.
+    fn read_sleb128(&mut self) -> Result<i64> {
+        leb128::read::signed(self)
+    }
+
+    /// Read an initial length field.
+    ///
+    /// This field is encoded as either a 32-bit length or
+    /// a 64-bit length, and the returned `Format` indicates which.
+    fn read_initial_length(&mut self) -> Result<(Self::Offset, Format)> {
+        const MAX_DWARF_32_UNIT_LENGTH: u32 = 0xffff_fff0;
+        const DWARF_64_INITIAL_UNIT_LENGTH: u32 = 0xffff_ffff;
+
+        let val = self.read_u32()?;
+        if val < MAX_DWARF_32_UNIT_LENGTH {
+            Ok((Self::Offset::from_u32(val), Format::Dwarf32))
+        } else if val == DWARF_64_INITIAL_UNIT_LENGTH {
+            let val = self.read_u64().and_then(Self::Offset::from_u64)?;
+            Ok((val, Format::Dwarf64))
+        } else {
+            Err(Error::UnknownReservedLength)
+        }
+    }
+
+    /// Read an address-sized integer, and return it as a `u64`.
+    fn read_address(&mut self, address_size: u8) -> Result<u64> {
+        match address_size {
+            1 => self.read_u8().map(u64::from),
+            2 => self.read_u16().map(u64::from),
+            4 => self.read_u32().map(u64::from),
+            8 => self.read_u64(),
+            otherwise => Err(Error::UnsupportedAddressSize(otherwise)),
+        }
+    }
+
+    /// Parse a word-sized integer according to the DWARF format.
+    ///
+    /// These are always used to encode section offsets or lengths,
+    /// and so have a type of `Self::Offset`.
+    fn read_word(&mut self, format: Format) -> Result<Self::Offset> {
+        match format {
+            Format::Dwarf32 => self.read_u32().map(Self::Offset::from_u32),
+            Format::Dwarf64 => self.read_u64().and_then(Self::Offset::from_u64),
+        }
+    }
+
+    /// Parse a word-sized section length according to the DWARF format.
+    #[inline]
+    fn read_length(&mut self, format: Format) -> Result<Self::Offset> {
+        self.read_word(format)
+    }
+
+    /// Parse a word-sized section offset according to the DWARF format.
+    #[inline]
+    fn read_offset(&mut self, format: Format) -> Result<Self::Offset> {
+        self.read_word(format)
+    }
+
+    /// Parse a section offset of the given size.
+    ///
+    /// This is used for `DW_FORM_ref_addr` values in DWARF version 2.
+    fn read_sized_offset(&mut self, size: u8) -> Result<Self::Offset> {
+        match size {
+            1 => self.read_u8().map(u64::from),
+            2 => self.read_u16().map(u64::from),
+            4 => self.read_u32().map(u64::from),
+            8 => self.read_u64(),
+            otherwise => Err(Error::UnsupportedOffsetSize(otherwise)),
+        }
+        .and_then(Self::Offset::from_u64)
+    }
+}