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-rw-r--r--vendor/gimli-0.26.2/src/write/writer.rs497
1 files changed, 497 insertions, 0 deletions
diff --git a/vendor/gimli-0.26.2/src/write/writer.rs b/vendor/gimli-0.26.2/src/write/writer.rs
new file mode 100644
index 000000000..0785d1686
--- /dev/null
+++ b/vendor/gimli-0.26.2/src/write/writer.rs
@@ -0,0 +1,497 @@
+use crate::common::{Format, SectionId};
+use crate::constants;
+use crate::endianity::Endianity;
+use crate::leb128;
+use crate::write::{Address, Error, Result};
+
+/// A trait for writing the data to a DWARF section.
+///
+/// All write operations append to the section unless otherwise specified.
+#[allow(clippy::len_without_is_empty)]
+pub trait Writer {
+ /// The endianity of bytes that are written.
+ type Endian: Endianity;
+
+ /// Return the endianity of bytes that are written.
+ fn endian(&self) -> Self::Endian;
+
+ /// Return the current section length.
+ ///
+ /// This may be used as an offset for future `write_at` calls.
+ fn len(&self) -> usize;
+
+ /// Write a slice.
+ fn write(&mut self, bytes: &[u8]) -> Result<()>;
+
+ /// Write a slice at a given offset.
+ ///
+ /// The write must not extend past the current section length.
+ fn write_at(&mut self, offset: usize, bytes: &[u8]) -> Result<()>;
+
+ /// Write an address.
+ ///
+ /// If the writer supports relocations, then it must provide its own implementation
+ /// of this method.
+ // TODO: use write_reference instead?
+ fn write_address(&mut self, address: Address, size: u8) -> Result<()> {
+ match address {
+ Address::Constant(val) => self.write_udata(val, size),
+ Address::Symbol { .. } => Err(Error::InvalidAddress),
+ }
+ }
+
+ /// Write an address with a `.eh_frame` pointer encoding.
+ ///
+ /// The given size is only used for `DW_EH_PE_absptr` formats.
+ ///
+ /// If the writer supports relocations, then it must provide its own implementation
+ /// of this method.
+ fn write_eh_pointer(
+ &mut self,
+ address: Address,
+ eh_pe: constants::DwEhPe,
+ size: u8,
+ ) -> Result<()> {
+ match address {
+ Address::Constant(val) => {
+ // Indirect doesn't matter here.
+ let val = match eh_pe.application() {
+ constants::DW_EH_PE_absptr => val,
+ constants::DW_EH_PE_pcrel => {
+ // TODO: better handling of sign
+ let offset = self.len() as u64;
+ val.wrapping_sub(offset)
+ }
+ _ => {
+ return Err(Error::UnsupportedPointerEncoding(eh_pe));
+ }
+ };
+ self.write_eh_pointer_data(val, eh_pe.format(), size)
+ }
+ Address::Symbol { .. } => Err(Error::InvalidAddress),
+ }
+ }
+
+ /// Write a value with a `.eh_frame` pointer format.
+ ///
+ /// The given size is only used for `DW_EH_PE_absptr` formats.
+ ///
+ /// This must not be used directly for values that may require relocation.
+ fn write_eh_pointer_data(
+ &mut self,
+ val: u64,
+ format: constants::DwEhPe,
+ size: u8,
+ ) -> Result<()> {
+ match format {
+ constants::DW_EH_PE_absptr => self.write_udata(val, size),
+ constants::DW_EH_PE_uleb128 => self.write_uleb128(val),
+ constants::DW_EH_PE_udata2 => self.write_udata(val, 2),
+ constants::DW_EH_PE_udata4 => self.write_udata(val, 4),
+ constants::DW_EH_PE_udata8 => self.write_udata(val, 8),
+ constants::DW_EH_PE_sleb128 => self.write_sleb128(val as i64),
+ constants::DW_EH_PE_sdata2 => self.write_sdata(val as i64, 2),
+ constants::DW_EH_PE_sdata4 => self.write_sdata(val as i64, 4),
+ constants::DW_EH_PE_sdata8 => self.write_sdata(val as i64, 8),
+ _ => {
+ return Err(Error::UnsupportedPointerEncoding(format));
+ }
+ }
+ }
+
+ /// Write an offset that is relative to the start of the given section.
+ ///
+ /// If the writer supports relocations, then it must provide its own implementation
+ /// of this method.
+ fn write_offset(&mut self, val: usize, _section: SectionId, size: u8) -> Result<()> {
+ self.write_udata(val as u64, size)
+ }
+
+ /// Write an offset that is relative to the start of the given section.
+ ///
+ /// If the writer supports relocations, then it must provide its own implementation
+ /// of this method.
+ fn write_offset_at(
+ &mut self,
+ offset: usize,
+ val: usize,
+ _section: SectionId,
+ size: u8,
+ ) -> Result<()> {
+ self.write_udata_at(offset, val as u64, size)
+ }
+
+ /// Write a reference to a symbol.
+ ///
+ /// If the writer supports symbols, then it must provide its own implementation
+ /// of this method.
+ fn write_reference(&mut self, _symbol: usize, _size: u8) -> Result<()> {
+ Err(Error::InvalidReference)
+ }
+
+ /// Write a u8.
+ fn write_u8(&mut self, val: u8) -> Result<()> {
+ let bytes = [val];
+ self.write(&bytes)
+ }
+
+ /// Write a u16.
+ fn write_u16(&mut self, val: u16) -> Result<()> {
+ let mut bytes = [0; 2];
+ self.endian().write_u16(&mut bytes, val);
+ self.write(&bytes)
+ }
+
+ /// Write a u32.
+ fn write_u32(&mut self, val: u32) -> Result<()> {
+ let mut bytes = [0; 4];
+ self.endian().write_u32(&mut bytes, val);
+ self.write(&bytes)
+ }
+
+ /// Write a u64.
+ fn write_u64(&mut self, val: u64) -> Result<()> {
+ let mut bytes = [0; 8];
+ self.endian().write_u64(&mut bytes, val);
+ self.write(&bytes)
+ }
+
+ /// Write a u8 at the given offset.
+ fn write_u8_at(&mut self, offset: usize, val: u8) -> Result<()> {
+ let bytes = [val];
+ self.write_at(offset, &bytes)
+ }
+
+ /// Write a u16 at the given offset.
+ fn write_u16_at(&mut self, offset: usize, val: u16) -> Result<()> {
+ let mut bytes = [0; 2];
+ self.endian().write_u16(&mut bytes, val);
+ self.write_at(offset, &bytes)
+ }
+
+ /// Write a u32 at the given offset.
+ fn write_u32_at(&mut self, offset: usize, val: u32) -> Result<()> {
+ let mut bytes = [0; 4];
+ self.endian().write_u32(&mut bytes, val);
+ self.write_at(offset, &bytes)
+ }
+
+ /// Write a u64 at the given offset.
+ fn write_u64_at(&mut self, offset: usize, val: u64) -> Result<()> {
+ let mut bytes = [0; 8];
+ self.endian().write_u64(&mut bytes, val);
+ self.write_at(offset, &bytes)
+ }
+
+ /// Write unsigned data of the given size.
+ ///
+ /// Returns an error if the value is too large for the size.
+ /// This must not be used directly for values that may require relocation.
+ fn write_udata(&mut self, val: u64, size: u8) -> Result<()> {
+ match size {
+ 1 => {
+ let write_val = val as u8;
+ if val != u64::from(write_val) {
+ return Err(Error::ValueTooLarge);
+ }
+ self.write_u8(write_val)
+ }
+ 2 => {
+ let write_val = val as u16;
+ if val != u64::from(write_val) {
+ return Err(Error::ValueTooLarge);
+ }
+ self.write_u16(write_val)
+ }
+ 4 => {
+ let write_val = val as u32;
+ if val != u64::from(write_val) {
+ return Err(Error::ValueTooLarge);
+ }
+ self.write_u32(write_val)
+ }
+ 8 => self.write_u64(val),
+ otherwise => Err(Error::UnsupportedWordSize(otherwise)),
+ }
+ }
+
+ /// Write signed data of the given size.
+ ///
+ /// Returns an error if the value is too large for the size.
+ /// This must not be used directly for values that may require relocation.
+ fn write_sdata(&mut self, val: i64, size: u8) -> Result<()> {
+ match size {
+ 1 => {
+ let write_val = val as i8;
+ if val != i64::from(write_val) {
+ return Err(Error::ValueTooLarge);
+ }
+ self.write_u8(write_val as u8)
+ }
+ 2 => {
+ let write_val = val as i16;
+ if val != i64::from(write_val) {
+ return Err(Error::ValueTooLarge);
+ }
+ self.write_u16(write_val as u16)
+ }
+ 4 => {
+ let write_val = val as i32;
+ if val != i64::from(write_val) {
+ return Err(Error::ValueTooLarge);
+ }
+ self.write_u32(write_val as u32)
+ }
+ 8 => self.write_u64(val as u64),
+ otherwise => Err(Error::UnsupportedWordSize(otherwise)),
+ }
+ }
+
+ /// Write a word of the given size at the given offset.
+ ///
+ /// Returns an error if the value is too large for the size.
+ /// This must not be used directly for values that may require relocation.
+ fn write_udata_at(&mut self, offset: usize, val: u64, size: u8) -> Result<()> {
+ match size {
+ 1 => {
+ let write_val = val as u8;
+ if val != u64::from(write_val) {
+ return Err(Error::ValueTooLarge);
+ }
+ self.write_u8_at(offset, write_val)
+ }
+ 2 => {
+ let write_val = val as u16;
+ if val != u64::from(write_val) {
+ return Err(Error::ValueTooLarge);
+ }
+ self.write_u16_at(offset, write_val)
+ }
+ 4 => {
+ let write_val = val as u32;
+ if val != u64::from(write_val) {
+ return Err(Error::ValueTooLarge);
+ }
+ self.write_u32_at(offset, write_val)
+ }
+ 8 => self.write_u64_at(offset, val),
+ otherwise => Err(Error::UnsupportedWordSize(otherwise)),
+ }
+ }
+
+ /// Write an unsigned LEB128 encoded integer.
+ fn write_uleb128(&mut self, val: u64) -> Result<()> {
+ let mut bytes = [0u8; 10];
+ // bytes is long enough so this will never fail.
+ let len = leb128::write::unsigned(&mut { &mut bytes[..] }, val).unwrap();
+ self.write(&bytes[..len])
+ }
+
+ /// Read an unsigned LEB128 encoded integer.
+ fn write_sleb128(&mut self, val: i64) -> Result<()> {
+ let mut bytes = [0u8; 10];
+ // bytes is long enough so this will never fail.
+ let len = leb128::write::signed(&mut { &mut bytes[..] }, val).unwrap();
+ self.write(&bytes[..len])
+ }
+
+ /// Write an initial length according to the given DWARF format.
+ ///
+ /// This will only write a length of zero, since the length isn't
+ /// known yet, and a subsequent call to `write_initial_length_at`
+ /// will write the actual length.
+ fn write_initial_length(&mut self, format: Format) -> Result<InitialLengthOffset> {
+ if format == Format::Dwarf64 {
+ self.write_u32(0xffff_ffff)?;
+ }
+ let offset = InitialLengthOffset(self.len());
+ self.write_udata(0, format.word_size())?;
+ Ok(offset)
+ }
+
+ /// Write an initial length at the given offset according to the given DWARF format.
+ ///
+ /// `write_initial_length` must have previously returned the offset.
+ fn write_initial_length_at(
+ &mut self,
+ offset: InitialLengthOffset,
+ length: u64,
+ format: Format,
+ ) -> Result<()> {
+ self.write_udata_at(offset.0, length, format.word_size())
+ }
+}
+
+/// The offset at which an initial length should be written.
+#[derive(Debug, Clone, Copy)]
+pub struct InitialLengthOffset(usize);
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+ use crate::write;
+ use crate::{BigEndian, LittleEndian};
+ use std::{i64, u64};
+
+ #[test]
+ #[allow(clippy::cyclomatic_complexity)]
+ fn test_writer() {
+ let mut w = write::EndianVec::new(LittleEndian);
+ w.write_address(Address::Constant(0x1122_3344), 4).unwrap();
+ assert_eq!(w.slice(), &[0x44, 0x33, 0x22, 0x11]);
+ assert_eq!(
+ w.write_address(
+ Address::Symbol {
+ symbol: 0,
+ addend: 0
+ },
+ 4
+ ),
+ Err(Error::InvalidAddress)
+ );
+
+ let mut w = write::EndianVec::new(LittleEndian);
+ w.write_offset(0x1122_3344, SectionId::DebugInfo, 4)
+ .unwrap();
+ assert_eq!(w.slice(), &[0x44, 0x33, 0x22, 0x11]);
+ w.write_offset_at(1, 0x5566, SectionId::DebugInfo, 2)
+ .unwrap();
+ assert_eq!(w.slice(), &[0x44, 0x66, 0x55, 0x11]);
+
+ let mut w = write::EndianVec::new(LittleEndian);
+ w.write_u8(0x11).unwrap();
+ w.write_u16(0x2233).unwrap();
+ w.write_u32(0x4455_6677).unwrap();
+ w.write_u64(0x8081_8283_8485_8687).unwrap();
+ #[rustfmt::skip]
+ assert_eq!(w.slice(), &[
+ 0x11,
+ 0x33, 0x22,
+ 0x77, 0x66, 0x55, 0x44,
+ 0x87, 0x86, 0x85, 0x84, 0x83, 0x82, 0x81, 0x80,
+ ]);
+ w.write_u8_at(14, 0x11).unwrap();
+ w.write_u16_at(12, 0x2233).unwrap();
+ w.write_u32_at(8, 0x4455_6677).unwrap();
+ w.write_u64_at(0, 0x8081_8283_8485_8687).unwrap();
+ #[rustfmt::skip]
+ assert_eq!(w.slice(), &[
+ 0x87, 0x86, 0x85, 0x84, 0x83, 0x82, 0x81, 0x80,
+ 0x77, 0x66, 0x55, 0x44,
+ 0x33, 0x22,
+ 0x11,
+ ]);
+
+ let mut w = write::EndianVec::new(BigEndian);
+ w.write_u8(0x11).unwrap();
+ w.write_u16(0x2233).unwrap();
+ w.write_u32(0x4455_6677).unwrap();
+ w.write_u64(0x8081_8283_8485_8687).unwrap();
+ #[rustfmt::skip]
+ assert_eq!(w.slice(), &[
+ 0x11,
+ 0x22, 0x33,
+ 0x44, 0x55, 0x66, 0x77,
+ 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+ ]);
+ w.write_u8_at(14, 0x11).unwrap();
+ w.write_u16_at(12, 0x2233).unwrap();
+ w.write_u32_at(8, 0x4455_6677).unwrap();
+ w.write_u64_at(0, 0x8081_8283_8485_8687).unwrap();
+ #[rustfmt::skip]
+ assert_eq!(w.slice(), &[
+ 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+ 0x44, 0x55, 0x66, 0x77,
+ 0x22, 0x33,
+ 0x11,
+ ]);
+
+ let mut w = write::EndianVec::new(LittleEndian);
+ w.write_udata(0x11, 1).unwrap();
+ w.write_udata(0x2233, 2).unwrap();
+ w.write_udata(0x4455_6677, 4).unwrap();
+ w.write_udata(0x8081_8283_8485_8687, 8).unwrap();
+ #[rustfmt::skip]
+ assert_eq!(w.slice(), &[
+ 0x11,
+ 0x33, 0x22,
+ 0x77, 0x66, 0x55, 0x44,
+ 0x87, 0x86, 0x85, 0x84, 0x83, 0x82, 0x81, 0x80,
+ ]);
+ assert_eq!(w.write_udata(0x100, 1), Err(Error::ValueTooLarge));
+ assert_eq!(w.write_udata(0x1_0000, 2), Err(Error::ValueTooLarge));
+ assert_eq!(w.write_udata(0x1_0000_0000, 4), Err(Error::ValueTooLarge));
+ assert_eq!(w.write_udata(0x00, 3), Err(Error::UnsupportedWordSize(3)));
+ w.write_udata_at(14, 0x11, 1).unwrap();
+ w.write_udata_at(12, 0x2233, 2).unwrap();
+ w.write_udata_at(8, 0x4455_6677, 4).unwrap();
+ w.write_udata_at(0, 0x8081_8283_8485_8687, 8).unwrap();
+ #[rustfmt::skip]
+ assert_eq!(w.slice(), &[
+ 0x87, 0x86, 0x85, 0x84, 0x83, 0x82, 0x81, 0x80,
+ 0x77, 0x66, 0x55, 0x44,
+ 0x33, 0x22,
+ 0x11,
+ ]);
+ assert_eq!(w.write_udata_at(0, 0x100, 1), Err(Error::ValueTooLarge));
+ assert_eq!(w.write_udata_at(0, 0x1_0000, 2), Err(Error::ValueTooLarge));
+ assert_eq!(
+ w.write_udata_at(0, 0x1_0000_0000, 4),
+ Err(Error::ValueTooLarge)
+ );
+ assert_eq!(
+ w.write_udata_at(0, 0x00, 3),
+ Err(Error::UnsupportedWordSize(3))
+ );
+
+ let mut w = write::EndianVec::new(LittleEndian);
+ w.write_uleb128(0).unwrap();
+ assert_eq!(w.slice(), &[0]);
+
+ let mut w = write::EndianVec::new(LittleEndian);
+ w.write_uleb128(u64::MAX).unwrap();
+ assert_eq!(
+ w.slice(),
+ &[0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 1]
+ );
+
+ let mut w = write::EndianVec::new(LittleEndian);
+ w.write_sleb128(0).unwrap();
+ assert_eq!(w.slice(), &[0]);
+
+ let mut w = write::EndianVec::new(LittleEndian);
+ w.write_sleb128(i64::MAX).unwrap();
+ assert_eq!(
+ w.slice(),
+ &[0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0]
+ );
+
+ let mut w = write::EndianVec::new(LittleEndian);
+ w.write_sleb128(i64::MIN).unwrap();
+ assert_eq!(
+ w.slice(),
+ &[0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x7f]
+ );
+
+ let mut w = write::EndianVec::new(LittleEndian);
+ let offset = w.write_initial_length(Format::Dwarf32).unwrap();
+ assert_eq!(w.slice(), &[0, 0, 0, 0]);
+ w.write_initial_length_at(offset, 0x1122_3344, Format::Dwarf32)
+ .unwrap();
+ assert_eq!(w.slice(), &[0x44, 0x33, 0x22, 0x11]);
+ assert_eq!(
+ w.write_initial_length_at(offset, 0x1_0000_0000, Format::Dwarf32),
+ Err(Error::ValueTooLarge)
+ );
+
+ let mut w = write::EndianVec::new(LittleEndian);
+ let offset = w.write_initial_length(Format::Dwarf64).unwrap();
+ assert_eq!(w.slice(), &[0xff, 0xff, 0xff, 0xff, 0, 0, 0, 0, 0, 0, 0, 0]);
+ w.write_initial_length_at(offset, 0x1122_3344_5566_7788, Format::Dwarf64)
+ .unwrap();
+ assert_eq!(
+ w.slice(),
+ &[0xff, 0xff, 0xff, 0xff, 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11]
+ );
+ }
+}
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