Adding upstream version 124.0.1.upstream/124.0.1

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

9 files changed, 2902 insertions, 0 deletions

diff --git a/third_party/rust/object/src/read/macho/dyld_cache.rs b/third_party/rust/object/src/read/macho/dyld_cache.rs
new file mode 100644
index 0000000000..68f27f5491
--- /dev/null
+++ b/third_party/rust/object/src/read/macho/dyld_cache.rs
@@ -0,0 +1,343 @@
+use alloc::vec::Vec;
+use core::slice;
+
+use crate::read::{Error, File, ReadError, ReadRef, Result};
+use crate::{macho, Architecture, Endian, Endianness};
+
+/// A parsed representation of the dyld shared cache.
+#[derive(Debug)]
+pub struct DyldCache<'data, E = Endianness, R = &'data [u8]>
+where
+    E: Endian,
+    R: ReadRef<'data>,
+{
+    endian: E,
+    data: R,
+    subcaches: Vec<DyldSubCache<'data, E, R>>,
+    mappings: &'data [macho::DyldCacheMappingInfo<E>],
+    images: &'data [macho::DyldCacheImageInfo<E>],
+    arch: Architecture,
+}
+
+/// Information about a subcache.
+#[derive(Debug)]
+pub struct DyldSubCache<'data, E = Endianness, R = &'data [u8]>
+where
+    E: Endian,
+    R: ReadRef<'data>,
+{
+    data: R,
+    mappings: &'data [macho::DyldCacheMappingInfo<E>],
+}
+
+// This is the offset of the images_across_all_subcaches_count field.
+const MIN_HEADER_SIZE_SUBCACHES: u32 = 0x1c4;
+
+impl<'data, E, R> DyldCache<'data, E, R>
+where
+    E: Endian,
+    R: ReadRef<'data>,
+{
+    /// Parse the raw dyld shared cache data.
+    /// For shared caches from macOS 12 / iOS 15 and above, the subcache files need to be
+    /// supplied as well, in the correct order, with the .symbols subcache last (if present).
+    /// For example, data would be the data for dyld_shared_cache_x86_64,
+    /// and subcache_data would be the data for [dyld_shared_cache_x86_64.1, dyld_shared_cache_x86_64.2, ...]
+    pub fn parse(data: R, subcache_data: &[R]) -> Result<Self> {
+        let header = macho::DyldCacheHeader::parse(data)?;
+        let (arch, endian) = header.parse_magic()?;
+        let mappings = header.mappings(endian, data)?;
+
+        let symbols_subcache_uuid = header.symbols_subcache_uuid(endian);
+        let subcaches_info = header.subcaches(endian, data)?.unwrap_or(&[]);
+
+        if subcache_data.len() != subcaches_info.len() + symbols_subcache_uuid.is_some() as usize {
+            return Err(Error("Incorrect number of SubCaches"));
+        }
+
+        // Split out the .symbols subcache data from the other subcaches.
+        let (symbols_subcache_data_and_uuid, subcache_data) =
+            if let Some(symbols_uuid) = symbols_subcache_uuid {
+                let (sym_data, rest_data) = subcache_data.split_last().unwrap();
+                (Some((*sym_data, symbols_uuid)), rest_data)
+            } else {
+                (None, subcache_data)
+            };
+
+        // Read the regular SubCaches (.1, .2, ...), if present.
+        let mut subcaches = Vec::new();
+        for (&data, info) in subcache_data.iter().zip(subcaches_info.iter()) {
+            let sc_header = macho::DyldCacheHeader::<E>::parse(data)?;
+            if sc_header.uuid != info.uuid {
+                return Err(Error("Unexpected SubCache UUID"));
+            }
+            let mappings = sc_header.mappings(endian, data)?;
+            subcaches.push(DyldSubCache { data, mappings });
+        }
+
+        // Read the .symbols SubCache, if present.
+        // Other than the UUID verification, the symbols SubCache is currently unused.
+        let _symbols_subcache = match symbols_subcache_data_and_uuid {
+            Some((data, uuid)) => {
+                let sc_header = macho::DyldCacheHeader::<E>::parse(data)?;
+                if sc_header.uuid != uuid {
+                    return Err(Error("Unexpected .symbols SubCache UUID"));
+                }
+                let mappings = sc_header.mappings(endian, data)?;
+                Some(DyldSubCache { data, mappings })
+            }
+            None => None,
+        };
+
+        let images = header.images(endian, data)?;
+        Ok(DyldCache {
+            endian,
+            data,
+            subcaches,
+            mappings,
+            images,
+            arch,
+        })
+    }
+
+    /// Get the architecture type of the file.
+    pub fn architecture(&self) -> Architecture {
+        self.arch
+    }
+
+    /// Get the endianness of the file.
+    #[inline]
+    pub fn endianness(&self) -> Endianness {
+        if self.is_little_endian() {
+            Endianness::Little
+        } else {
+            Endianness::Big
+        }
+    }
+
+    /// Return true if the file is little endian, false if it is big endian.
+    pub fn is_little_endian(&self) -> bool {
+        self.endian.is_little_endian()
+    }
+
+    /// Iterate over the images in this cache.
+    pub fn images<'cache>(&'cache self) -> DyldCacheImageIterator<'data, 'cache, E, R> {
+        DyldCacheImageIterator {
+            cache: self,
+            iter: self.images.iter(),
+        }
+    }
+
+    /// Find the address in a mapping and return the cache or subcache data it was found in,
+    /// together with the translated file offset.
+    pub fn data_and_offset_for_address(&self, address: u64) -> Option<(R, u64)> {
+        if let Some(file_offset) = address_to_file_offset(address, self.endian, self.mappings) {
+            return Some((self.data, file_offset));
+        }
+        for subcache in &self.subcaches {
+            if let Some(file_offset) =
+                address_to_file_offset(address, self.endian, subcache.mappings)
+            {
+                return Some((subcache.data, file_offset));
+            }
+        }
+        None
+    }
+}
+
+/// An iterator over all the images (dylibs) in the dyld shared cache.
+#[derive(Debug)]
+pub struct DyldCacheImageIterator<'data, 'cache, E = Endianness, R = &'data [u8]>
+where
+    E: Endian,
+    R: ReadRef<'data>,
+{
+    cache: &'cache DyldCache<'data, E, R>,
+    iter: slice::Iter<'data, macho::DyldCacheImageInfo<E>>,
+}
+
+impl<'data, 'cache, E, R> Iterator for DyldCacheImageIterator<'data, 'cache, E, R>
+where
+    E: Endian,
+    R: ReadRef<'data>,
+{
+    type Item = DyldCacheImage<'data, 'cache, E, R>;
+
+    fn next(&mut self) -> Option<DyldCacheImage<'data, 'cache, E, R>> {
+        let image_info = self.iter.next()?;
+        Some(DyldCacheImage {
+            cache: self.cache,
+            image_info,
+        })
+    }
+}
+
+/// One image (dylib) from inside the dyld shared cache.
+#[derive(Debug)]
+pub struct DyldCacheImage<'data, 'cache, E = Endianness, R = &'data [u8]>
+where
+    E: Endian,
+    R: ReadRef<'data>,
+{
+    pub(crate) cache: &'cache DyldCache<'data, E, R>,
+    image_info: &'data macho::DyldCacheImageInfo<E>,
+}
+
+impl<'data, 'cache, E, R> DyldCacheImage<'data, 'cache, E, R>
+where
+    E: Endian,
+    R: ReadRef<'data>,
+{
+    /// The file system path of this image.
+    pub fn path(&self) -> Result<&'data str> {
+        let path = self.image_info.path(self.cache.endian, self.cache.data)?;
+        // The path should always be ascii, so from_utf8 should always succeed.
+        let path = core::str::from_utf8(path).map_err(|_| Error("Path string not valid utf-8"))?;
+        Ok(path)
+    }
+
+    /// The subcache data which contains the Mach-O header for this image,
+    /// together with the file offset at which this image starts.
+    pub fn image_data_and_offset(&self) -> Result<(R, u64)> {
+        let address = self.image_info.address.get(self.cache.endian);
+        self.cache
+            .data_and_offset_for_address(address)
+            .ok_or(Error("Address not found in any mapping"))
+    }
+
+    /// Parse this image into an Object.
+    pub fn parse_object(&self) -> Result<File<'data, R>> {
+        File::parse_dyld_cache_image(self)
+    }
+}
+
+impl<E: Endian> macho::DyldCacheHeader<E> {
+    /// Read the dyld cache header.
+    pub fn parse<'data, R: ReadRef<'data>>(data: R) -> Result<&'data Self> {
+        data.read_at::<macho::DyldCacheHeader<E>>(0)
+            .read_error("Invalid dyld cache header size or alignment")
+    }
+
+    /// Returns (arch, endian) based on the magic string.
+    pub fn parse_magic(&self) -> Result<(Architecture, E)> {
+        let (arch, is_big_endian) = match &self.magic {
+            b"dyld_v1    i386\0" => (Architecture::I386, false),
+            b"dyld_v1  x86_64\0" => (Architecture::X86_64, false),
+            b"dyld_v1 x86_64h\0" => (Architecture::X86_64, false),
+            b"dyld_v1     ppc\0" => (Architecture::PowerPc, true),
+            b"dyld_v1   armv6\0" => (Architecture::Arm, false),
+            b"dyld_v1   armv7\0" => (Architecture::Arm, false),
+            b"dyld_v1  armv7f\0" => (Architecture::Arm, false),
+            b"dyld_v1  armv7s\0" => (Architecture::Arm, false),
+            b"dyld_v1  armv7k\0" => (Architecture::Arm, false),
+            b"dyld_v1   arm64\0" => (Architecture::Aarch64, false),
+            b"dyld_v1  arm64e\0" => (Architecture::Aarch64, false),
+            _ => return Err(Error("Unrecognized dyld cache magic")),
+        };
+        let endian =
+            E::from_big_endian(is_big_endian).read_error("Unsupported dyld cache endian")?;
+        Ok((arch, endian))
+    }
+
+    /// Return the mapping information table.
+    pub fn mappings<'data, R: ReadRef<'data>>(
+        &self,
+        endian: E,
+        data: R,
+    ) -> Result<&'data [macho::DyldCacheMappingInfo<E>]> {
+        data.read_slice_at::<macho::DyldCacheMappingInfo<E>>(
+            self.mapping_offset.get(endian).into(),
+            self.mapping_count.get(endian) as usize,
+        )
+        .read_error("Invalid dyld cache mapping size or alignment")
+    }
+
+    /// Return the information about subcaches, if present.
+    pub fn subcaches<'data, R: ReadRef<'data>>(
+        &self,
+        endian: E,
+        data: R,
+    ) -> Result<Option<&'data [macho::DyldSubCacheInfo<E>]>> {
+        if self.mapping_offset.get(endian) >= MIN_HEADER_SIZE_SUBCACHES {
+            let subcaches = data
+                .read_slice_at::<macho::DyldSubCacheInfo<E>>(
+                    self.subcaches_offset.get(endian).into(),
+                    self.subcaches_count.get(endian) as usize,
+                )
+                .read_error("Invalid dyld subcaches size or alignment")?;
+            Ok(Some(subcaches))
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Return the UUID for the .symbols subcache, if present.
+    pub fn symbols_subcache_uuid(&self, endian: E) -> Option<[u8; 16]> {
+        if self.mapping_offset.get(endian) >= MIN_HEADER_SIZE_SUBCACHES {
+            let uuid = self.symbols_subcache_uuid;
+            if uuid != [0; 16] {
+                return Some(uuid);
+            }
+        }
+        None
+    }
+
+    /// Return the image information table.
+    pub fn images<'data, R: ReadRef<'data>>(
+        &self,
+        endian: E,
+        data: R,
+    ) -> Result<&'data [macho::DyldCacheImageInfo<E>]> {
+        if self.mapping_offset.get(endian) >= MIN_HEADER_SIZE_SUBCACHES {
+            data.read_slice_at::<macho::DyldCacheImageInfo<E>>(
+                self.images_across_all_subcaches_offset.get(endian).into(),
+                self.images_across_all_subcaches_count.get(endian) as usize,
+            )
+            .read_error("Invalid dyld cache image size or alignment")
+        } else {
+            data.read_slice_at::<macho::DyldCacheImageInfo<E>>(
+                self.images_offset.get(endian).into(),
+                self.images_count.get(endian) as usize,
+            )
+            .read_error("Invalid dyld cache image size or alignment")
+        }
+    }
+}
+
+impl<E: Endian> macho::DyldCacheImageInfo<E> {
+    /// The file system path of this image.
+    pub fn path<'data, R: ReadRef<'data>>(&self, endian: E, data: R) -> Result<&'data [u8]> {
+        let r_start = self.path_file_offset.get(endian).into();
+        let r_end = data.len().read_error("Couldn't get data len()")?;
+        data.read_bytes_at_until(r_start..r_end, 0)
+            .read_error("Couldn't read dyld cache image path")
+    }
+
+    /// Find the file offset of the image by looking up its address in the mappings.
+    pub fn file_offset(
+        &self,
+        endian: E,
+        mappings: &[macho::DyldCacheMappingInfo<E>],
+    ) -> Result<u64> {
+        let address = self.address.get(endian);
+        address_to_file_offset(address, endian, mappings)
+            .read_error("Invalid dyld cache image address")
+    }
+}
+
+/// Find the file offset of the image by looking up its address in the mappings.
+pub fn address_to_file_offset<E: Endian>(
+    address: u64,
+    endian: E,
+    mappings: &[macho::DyldCacheMappingInfo<E>],
+) -> Option<u64> {
+    for mapping in mappings {
+        let mapping_address = mapping.address.get(endian);
+        if address >= mapping_address
+            && address < mapping_address.wrapping_add(mapping.size.get(endian))
+        {
+            return Some(address - mapping_address + mapping.file_offset.get(endian));
+        }
+    }
+    None
+}
diff --git a/third_party/rust/object/src/read/macho/fat.rs b/third_party/rust/object/src/read/macho/fat.rs
new file mode 100644
index 0000000000..d4301b7e11
--- /dev/null
+++ b/third_party/rust/object/src/read/macho/fat.rs
@@ -0,0 +1,122 @@
+use crate::read::{Architecture, Error, ReadError, ReadRef, Result};
+use crate::{macho, BigEndian, Pod};
+
+pub use macho::{FatArch32, FatArch64, FatHeader};
+
+impl FatHeader {
+    /// Attempt to parse a fat header.
+    ///
+    /// Does not validate the magic value.
+    pub fn parse<'data, R: ReadRef<'data>>(file: R) -> Result<&'data FatHeader> {
+        file.read_at::<FatHeader>(0)
+            .read_error("Invalid fat header size or alignment")
+    }
+
+    /// Attempt to parse a fat header and 32-bit fat arches.
+    pub fn parse_arch32<'data, R: ReadRef<'data>>(file: R) -> Result<&'data [FatArch32]> {
+        let mut offset = 0;
+        let header = file
+            .read::<FatHeader>(&mut offset)
+            .read_error("Invalid fat header size or alignment")?;
+        if header.magic.get(BigEndian) != macho::FAT_MAGIC {
+            return Err(Error("Invalid 32-bit fat magic"));
+        }
+        file.read_slice::<FatArch32>(&mut offset, header.nfat_arch.get(BigEndian) as usize)
+            .read_error("Invalid nfat_arch")
+    }
+
+    /// Attempt to parse a fat header and 64-bit fat arches.
+    pub fn parse_arch64<'data, R: ReadRef<'data>>(file: R) -> Result<&'data [FatArch64]> {
+        let mut offset = 0;
+        let header = file
+            .read::<FatHeader>(&mut offset)
+            .read_error("Invalid fat header size or alignment")?;
+        if header.magic.get(BigEndian) != macho::FAT_MAGIC_64 {
+            return Err(Error("Invalid 64-bit fat magic"));
+        }
+        file.read_slice::<FatArch64>(&mut offset, header.nfat_arch.get(BigEndian) as usize)
+            .read_error("Invalid nfat_arch")
+    }
+}
+
+/// A trait for generic access to `FatArch32` and `FatArch64`.
+#[allow(missing_docs)]
+pub trait FatArch: Pod {
+    type Word: Into<u64>;
+
+    fn cputype(&self) -> u32;
+    fn cpusubtype(&self) -> u32;
+    fn offset(&self) -> Self::Word;
+    fn size(&self) -> Self::Word;
+    fn align(&self) -> u32;
+
+    fn architecture(&self) -> Architecture {
+        match self.cputype() {
+            macho::CPU_TYPE_ARM => Architecture::Arm,
+            macho::CPU_TYPE_ARM64 => Architecture::Aarch64,
+            macho::CPU_TYPE_X86 => Architecture::I386,
+            macho::CPU_TYPE_X86_64 => Architecture::X86_64,
+            macho::CPU_TYPE_MIPS => Architecture::Mips,
+            macho::CPU_TYPE_POWERPC => Architecture::PowerPc,
+            macho::CPU_TYPE_POWERPC64 => Architecture::PowerPc64,
+            _ => Architecture::Unknown,
+        }
+    }
+
+    fn file_range(&self) -> (u64, u64) {
+        (self.offset().into(), self.size().into())
+    }
+
+    fn data<'data, R: ReadRef<'data>>(&self, file: R) -> Result<&'data [u8]> {
+        file.read_bytes_at(self.offset().into(), self.size().into())
+            .read_error("Invalid fat arch offset or size")
+    }
+}
+
+impl FatArch for FatArch32 {
+    type Word = u32;
+
+    fn cputype(&self) -> u32 {
+        self.cputype.get(BigEndian)
+    }
+
+    fn cpusubtype(&self) -> u32 {
+        self.cpusubtype.get(BigEndian)
+    }
+
+    fn offset(&self) -> Self::Word {
+        self.offset.get(BigEndian)
+    }
+
+    fn size(&self) -> Self::Word {
+        self.size.get(BigEndian)
+    }
+
+    fn align(&self) -> u32 {
+        self.align.get(BigEndian)
+    }
+}
+
+impl FatArch for FatArch64 {
+    type Word = u64;
+
+    fn cputype(&self) -> u32 {
+        self.cputype.get(BigEndian)
+    }
+
+    fn cpusubtype(&self) -> u32 {
+        self.cpusubtype.get(BigEndian)
+    }
+
+    fn offset(&self) -> Self::Word {
+        self.offset.get(BigEndian)
+    }
+
+    fn size(&self) -> Self::Word {
+        self.size.get(BigEndian)
+    }
+
+    fn align(&self) -> u32 {
+        self.align.get(BigEndian)
+    }
+}
diff --git a/third_party/rust/object/src/read/macho/file.rs b/third_party/rust/object/src/read/macho/file.rs
new file mode 100644
index 0000000000..368c28bbd2
--- /dev/null
+++ b/third_party/rust/object/src/read/macho/file.rs
@@ -0,0 +1,731 @@
+use alloc::vec::Vec;
+use core::fmt::Debug;
+use core::{mem, str};
+
+use crate::read::{
+    self, Architecture, ComdatKind, Error, Export, FileFlags, Import, NoDynamicRelocationIterator,
+    Object, ObjectComdat, ObjectKind, ObjectMap, ObjectSection, ReadError, ReadRef, Result,
+    SectionIndex, SymbolIndex,
+};
+use crate::{endian, macho, BigEndian, ByteString, Endian, Endianness, Pod};
+
+use super::{
+    DyldCacheImage, LoadCommandIterator, MachOSection, MachOSectionInternal, MachOSectionIterator,
+    MachOSegment, MachOSegmentInternal, MachOSegmentIterator, MachOSymbol, MachOSymbolIterator,
+    MachOSymbolTable, Nlist, Section, Segment, SymbolTable,
+};
+
+/// A 32-bit Mach-O object file.
+pub type MachOFile32<'data, Endian = Endianness, R = &'data [u8]> =
+    MachOFile<'data, macho::MachHeader32<Endian>, R>;
+/// A 64-bit Mach-O object file.
+pub type MachOFile64<'data, Endian = Endianness, R = &'data [u8]> =
+    MachOFile<'data, macho::MachHeader64<Endian>, R>;
+
+/// A partially parsed Mach-O file.
+///
+/// Most of the functionality of this type is provided by the `Object` trait implementation.
+#[derive(Debug)]
+pub struct MachOFile<'data, Mach, R = &'data [u8]>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    pub(super) endian: Mach::Endian,
+    pub(super) data: R,
+    pub(super) header_offset: u64,
+    pub(super) header: &'data Mach,
+    pub(super) segments: Vec<MachOSegmentInternal<'data, Mach, R>>,
+    pub(super) sections: Vec<MachOSectionInternal<'data, Mach>>,
+    pub(super) symbols: SymbolTable<'data, Mach, R>,
+}
+
+impl<'data, Mach, R> MachOFile<'data, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    /// Parse the raw Mach-O file data.
+    pub fn parse(data: R) -> Result<Self> {
+        let header = Mach::parse(data, 0)?;
+        let endian = header.endian()?;
+
+        // Build a list of segments and sections to make some operations more efficient.
+        let mut segments = Vec::new();
+        let mut sections = Vec::new();
+        let mut symbols = SymbolTable::default();
+        if let Ok(mut commands) = header.load_commands(endian, data, 0) {
+            while let Ok(Some(command)) = commands.next() {
+                if let Some((segment, section_data)) = Mach::Segment::from_command(command)? {
+                    let segment_index = segments.len();
+                    segments.push(MachOSegmentInternal { segment, data });
+                    for section in segment.sections(endian, section_data)? {
+                        let index = SectionIndex(sections.len() + 1);
+                        sections.push(MachOSectionInternal::parse(index, segment_index, section));
+                    }
+                } else if let Some(symtab) = command.symtab()? {
+                    symbols = symtab.symbols(endian, data)?;
+                }
+            }
+        }
+
+        Ok(MachOFile {
+            endian,
+            data,
+            header_offset: 0,
+            header,
+            segments,
+            sections,
+            symbols,
+        })
+    }
+
+    /// Parse the Mach-O file for the given image from the dyld shared cache.
+    /// This will read different sections from different subcaches, if necessary.
+    pub fn parse_dyld_cache_image<'cache, E: Endian>(
+        image: &DyldCacheImage<'data, 'cache, E, R>,
+    ) -> Result<Self> {
+        let (data, header_offset) = image.image_data_and_offset()?;
+        let header = Mach::parse(data, header_offset)?;
+        let endian = header.endian()?;
+
+        // Build a list of sections to make some operations more efficient.
+        // Also build a list of segments, because we need to remember which ReadRef
+        // to read each section's data from. Only the DyldCache knows this information,
+        // and we won't have access to it once we've exited this function.
+        let mut segments = Vec::new();
+        let mut sections = Vec::new();
+        let mut linkedit_data: Option<R> = None;
+        let mut symtab = None;
+        if let Ok(mut commands) = header.load_commands(endian, data, header_offset) {
+            while let Ok(Some(command)) = commands.next() {
+                if let Some((segment, section_data)) = Mach::Segment::from_command(command)? {
+                    // Each segment can be stored in a different subcache. Get the segment's
+                    // address and look it up in the cache mappings, to find the correct cache data.
+                    let addr = segment.vmaddr(endian).into();
+                    let (data, _offset) = image
+                        .cache
+                        .data_and_offset_for_address(addr)
+                        .read_error("Could not find segment data in dyld shared cache")?;
+                    if segment.name() == macho::SEG_LINKEDIT.as_bytes() {
+                        linkedit_data = Some(data);
+                    }
+                    let segment_index = segments.len();
+                    segments.push(MachOSegmentInternal { segment, data });
+
+                    for section in segment.sections(endian, section_data)? {
+                        let index = SectionIndex(sections.len() + 1);
+                        sections.push(MachOSectionInternal::parse(index, segment_index, section));
+                    }
+                } else if let Some(st) = command.symtab()? {
+                    symtab = Some(st);
+                }
+            }
+        }
+
+        // The symbols are found in the __LINKEDIT segment, so make sure to read them from the
+        // correct subcache.
+        let symbols = match (symtab, linkedit_data) {
+            (Some(symtab), Some(linkedit_data)) => symtab.symbols(endian, linkedit_data)?,
+            _ => SymbolTable::default(),
+        };
+
+        Ok(MachOFile {
+            endian,
+            data,
+            header_offset,
+            header,
+            segments,
+            sections,
+            symbols,
+        })
+    }
+
+    /// Return the section at the given index.
+    #[inline]
+    pub(super) fn section_internal(
+        &self,
+        index: SectionIndex,
+    ) -> Result<&MachOSectionInternal<'data, Mach>> {
+        index
+            .0
+            .checked_sub(1)
+            .and_then(|index| self.sections.get(index))
+            .read_error("Invalid Mach-O section index")
+    }
+
+    pub(super) fn segment_internal(
+        &self,
+        index: usize,
+    ) -> Result<&MachOSegmentInternal<'data, Mach, R>> {
+        self.segments
+            .get(index)
+            .read_error("Invalid Mach-O segment index")
+    }
+}
+
+impl<'data, Mach, R> read::private::Sealed for MachOFile<'data, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+}
+
+impl<'data, 'file, Mach, R> Object<'data, 'file> for MachOFile<'data, Mach, R>
+where
+    'data: 'file,
+    Mach: MachHeader,
+    R: 'file + ReadRef<'data>,
+{
+    type Segment = MachOSegment<'data, 'file, Mach, R>;
+    type SegmentIterator = MachOSegmentIterator<'data, 'file, Mach, R>;
+    type Section = MachOSection<'data, 'file, Mach, R>;
+    type SectionIterator = MachOSectionIterator<'data, 'file, Mach, R>;
+    type Comdat = MachOComdat<'data, 'file, Mach, R>;
+    type ComdatIterator = MachOComdatIterator<'data, 'file, Mach, R>;
+    type Symbol = MachOSymbol<'data, 'file, Mach, R>;
+    type SymbolIterator = MachOSymbolIterator<'data, 'file, Mach, R>;
+    type SymbolTable = MachOSymbolTable<'data, 'file, Mach, R>;
+    type DynamicRelocationIterator = NoDynamicRelocationIterator;
+
+    fn architecture(&self) -> Architecture {
+        match self.header.cputype(self.endian) {
+            macho::CPU_TYPE_ARM => Architecture::Arm,
+            macho::CPU_TYPE_ARM64 => Architecture::Aarch64,
+            macho::CPU_TYPE_ARM64_32 => Architecture::Aarch64_Ilp32,
+            macho::CPU_TYPE_X86 => Architecture::I386,
+            macho::CPU_TYPE_X86_64 => Architecture::X86_64,
+            macho::CPU_TYPE_MIPS => Architecture::Mips,
+            macho::CPU_TYPE_POWERPC => Architecture::PowerPc,
+            macho::CPU_TYPE_POWERPC64 => Architecture::PowerPc64,
+            _ => Architecture::Unknown,
+        }
+    }
+
+    #[inline]
+    fn is_little_endian(&self) -> bool {
+        self.header.is_little_endian()
+    }
+
+    #[inline]
+    fn is_64(&self) -> bool {
+        self.header.is_type_64()
+    }
+
+    fn kind(&self) -> ObjectKind {
+        match self.header.filetype(self.endian) {
+            macho::MH_OBJECT => ObjectKind::Relocatable,
+            macho::MH_EXECUTE => ObjectKind::Executable,
+            macho::MH_CORE => ObjectKind::Core,
+            macho::MH_DYLIB => ObjectKind::Dynamic,
+            _ => ObjectKind::Unknown,
+        }
+    }
+
+    fn segments(&'file self) -> MachOSegmentIterator<'data, 'file, Mach, R> {
+        MachOSegmentIterator {
+            file: self,
+            iter: self.segments.iter(),
+        }
+    }
+
+    fn section_by_name_bytes(
+        &'file self,
+        section_name: &[u8],
+    ) -> Option<MachOSection<'data, 'file, Mach, R>> {
+        // Translate the "." prefix to the "__" prefix used by OSX/Mach-O, eg
+        // ".debug_info" to "__debug_info", and limit to 16 bytes total.
+        let system_name = if section_name.starts_with(b".") {
+            if section_name.len() > 15 {
+                Some(&section_name[1..15])
+            } else {
+                Some(&section_name[1..])
+            }
+        } else {
+            None
+        };
+        let cmp_section_name = |section: &MachOSection<'data, 'file, Mach, R>| {
+            section
+                .name_bytes()
+                .map(|name| {
+                    section_name == name
+                        || system_name
+                            .filter(|system_name| {
+                                name.starts_with(b"__") && name[2..] == **system_name
+                            })
+                            .is_some()
+                })
+                .unwrap_or(false)
+        };
+
+        self.sections().find(cmp_section_name)
+    }
+
+    fn section_by_index(
+        &'file self,
+        index: SectionIndex,
+    ) -> Result<MachOSection<'data, 'file, Mach, R>> {
+        let internal = *self.section_internal(index)?;
+        Ok(MachOSection {
+            file: self,
+            internal,
+        })
+    }
+
+    fn sections(&'file self) -> MachOSectionIterator<'data, 'file, Mach, R> {
+        MachOSectionIterator {
+            file: self,
+            iter: self.sections.iter(),
+        }
+    }
+
+    fn comdats(&'file self) -> MachOComdatIterator<'data, 'file, Mach, R> {
+        MachOComdatIterator { file: self }
+    }
+
+    fn symbol_by_index(
+        &'file self,
+        index: SymbolIndex,
+    ) -> Result<MachOSymbol<'data, 'file, Mach, R>> {
+        let nlist = self.symbols.symbol(index.0)?;
+        MachOSymbol::new(self, index, nlist).read_error("Unsupported Mach-O symbol index")
+    }
+
+    fn symbols(&'file self) -> MachOSymbolIterator<'data, 'file, Mach, R> {
+        MachOSymbolIterator {
+            file: self,
+            index: 0,
+        }
+    }
+
+    #[inline]
+    fn symbol_table(&'file self) -> Option<MachOSymbolTable<'data, 'file, Mach, R>> {
+        Some(MachOSymbolTable { file: self })
+    }
+
+    fn dynamic_symbols(&'file self) -> MachOSymbolIterator<'data, 'file, Mach, R> {
+        MachOSymbolIterator {
+            file: self,
+            index: self.symbols.len(),
+        }
+    }
+
+    #[inline]
+    fn dynamic_symbol_table(&'file self) -> Option<MachOSymbolTable<'data, 'file, Mach, R>> {
+        None
+    }
+
+    fn object_map(&'file self) -> ObjectMap<'data> {
+        self.symbols.object_map(self.endian)
+    }
+
+    fn imports(&self) -> Result<Vec<Import<'data>>> {
+        let mut dysymtab = None;
+        let mut libraries = Vec::new();
+        let twolevel = self.header.flags(self.endian) & macho::MH_TWOLEVEL != 0;
+        if twolevel {
+            libraries.push(&[][..]);
+        }
+        let mut commands = self
+            .header
+            .load_commands(self.endian, self.data, self.header_offset)?;
+        while let Some(command) = commands.next()? {
+            if let Some(command) = command.dysymtab()? {
+                dysymtab = Some(command);
+            }
+            if twolevel {
+                if let Some(dylib) = command.dylib()? {
+                    libraries.push(command.string(self.endian, dylib.dylib.name)?);
+                }
+            }
+        }
+
+        let mut imports = Vec::new();
+        if let Some(dysymtab) = dysymtab {
+            let index = dysymtab.iundefsym.get(self.endian) as usize;
+            let number = dysymtab.nundefsym.get(self.endian) as usize;
+            for i in index..(index.wrapping_add(number)) {
+                let symbol = self.symbols.symbol(i)?;
+                let name = symbol.name(self.endian, self.symbols.strings())?;
+                let library = if twolevel {
+                    libraries
+                        .get(symbol.library_ordinal(self.endian) as usize)
+                        .copied()
+                        .read_error("Invalid Mach-O symbol library ordinal")?
+                } else {
+                    &[]
+                };
+                imports.push(Import {
+                    name: ByteString(name),
+                    library: ByteString(library),
+                });
+            }
+        }
+        Ok(imports)
+    }
+
+    fn exports(&self) -> Result<Vec<Export<'data>>> {
+        let mut dysymtab = None;
+        let mut commands = self
+            .header
+            .load_commands(self.endian, self.data, self.header_offset)?;
+        while let Some(command) = commands.next()? {
+            if let Some(command) = command.dysymtab()? {
+                dysymtab = Some(command);
+                break;
+            }
+        }
+
+        let mut exports = Vec::new();
+        if let Some(dysymtab) = dysymtab {
+            let index = dysymtab.iextdefsym.get(self.endian) as usize;
+            let number = dysymtab.nextdefsym.get(self.endian) as usize;
+            for i in index..(index.wrapping_add(number)) {
+                let symbol = self.symbols.symbol(i)?;
+                let name = symbol.name(self.endian, self.symbols.strings())?;
+                let address = symbol.n_value(self.endian).into();
+                exports.push(Export {
+                    name: ByteString(name),
+                    address,
+                });
+            }
+        }
+        Ok(exports)
+    }
+
+    #[inline]
+    fn dynamic_relocations(&'file self) -> Option<NoDynamicRelocationIterator> {
+        None
+    }
+
+    fn has_debug_symbols(&self) -> bool {
+        self.section_by_name(".debug_info").is_some()
+    }
+
+    fn mach_uuid(&self) -> Result<Option<[u8; 16]>> {
+        self.header.uuid(self.endian, self.data, self.header_offset)
+    }
+
+    fn relative_address_base(&self) -> u64 {
+        0
+    }
+
+    fn entry(&self) -> u64 {
+        if let Ok(mut commands) =
+            self.header
+                .load_commands(self.endian, self.data, self.header_offset)
+        {
+            while let Ok(Some(command)) = commands.next() {
+                if let Ok(Some(command)) = command.entry_point() {
+                    return command.entryoff.get(self.endian);
+                }
+            }
+        }
+        0
+    }
+
+    fn flags(&self) -> FileFlags {
+        FileFlags::MachO {
+            flags: self.header.flags(self.endian),
+        }
+    }
+}
+
+/// An iterator over the COMDAT section groups of a `MachOFile64`.
+pub type MachOComdatIterator32<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOComdatIterator<'data, 'file, macho::MachHeader32<Endian>, R>;
+/// An iterator over the COMDAT section groups of a `MachOFile64`.
+pub type MachOComdatIterator64<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOComdatIterator<'data, 'file, macho::MachHeader64<Endian>, R>;
+
+/// An iterator over the COMDAT section groups of a `MachOFile`.
+#[derive(Debug)]
+pub struct MachOComdatIterator<'data, 'file, Mach, R = &'data [u8]>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    #[allow(unused)]
+    file: &'file MachOFile<'data, Mach, R>,
+}
+
+impl<'data, 'file, Mach, R> Iterator for MachOComdatIterator<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    type Item = MachOComdat<'data, 'file, Mach, R>;
+
+    #[inline]
+    fn next(&mut self) -> Option<Self::Item> {
+        None
+    }
+}
+
+/// A COMDAT section group of a `MachOFile32`.
+pub type MachOComdat32<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOComdat<'data, 'file, macho::MachHeader32<Endian>, R>;
+
+/// A COMDAT section group of a `MachOFile64`.
+pub type MachOComdat64<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOComdat<'data, 'file, macho::MachHeader64<Endian>, R>;
+
+/// A COMDAT section group of a `MachOFile`.
+#[derive(Debug)]
+pub struct MachOComdat<'data, 'file, Mach, R = &'data [u8]>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    #[allow(unused)]
+    file: &'file MachOFile<'data, Mach, R>,
+}
+
+impl<'data, 'file, Mach, R> read::private::Sealed for MachOComdat<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+}
+
+impl<'data, 'file, Mach, R> ObjectComdat<'data> for MachOComdat<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    type SectionIterator = MachOComdatSectionIterator<'data, 'file, Mach, R>;
+
+    #[inline]
+    fn kind(&self) -> ComdatKind {
+        unreachable!();
+    }
+
+    #[inline]
+    fn symbol(&self) -> SymbolIndex {
+        unreachable!();
+    }
+
+    #[inline]
+    fn name_bytes(&self) -> Result<&[u8]> {
+        unreachable!();
+    }
+
+    #[inline]
+    fn name(&self) -> Result<&str> {
+        unreachable!();
+    }
+
+    #[inline]
+    fn sections(&self) -> Self::SectionIterator {
+        unreachable!();
+    }
+}
+
+/// An iterator over the sections in a COMDAT section group of a `MachOFile32`.
+pub type MachOComdatSectionIterator32<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOComdatSectionIterator<'data, 'file, macho::MachHeader32<Endian>, R>;
+/// An iterator over the sections in a COMDAT section group of a `MachOFile64`.
+pub type MachOComdatSectionIterator64<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOComdatSectionIterator<'data, 'file, macho::MachHeader64<Endian>, R>;
+
+/// An iterator over the sections in a COMDAT section group of a `MachOFile`.
+#[derive(Debug)]
+pub struct MachOComdatSectionIterator<'data, 'file, Mach, R = &'data [u8]>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    #[allow(unused)]
+    file: &'file MachOFile<'data, Mach, R>,
+}
+
+impl<'data, 'file, Mach, R> Iterator for MachOComdatSectionIterator<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    type Item = SectionIndex;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        None
+    }
+}
+
+/// A trait for generic access to `MachHeader32` and `MachHeader64`.
+#[allow(missing_docs)]
+pub trait MachHeader: Debug + Pod {
+    type Word: Into<u64>;
+    type Endian: endian::Endian;
+    type Segment: Segment<Endian = Self::Endian, Section = Self::Section>;
+    type Section: Section<Endian = Self::Endian>;
+    type Nlist: Nlist<Endian = Self::Endian>;
+
+    /// Return true if this type is a 64-bit header.
+    ///
+    /// This is a property of the type, not a value in the header data.
+    fn is_type_64(&self) -> bool;
+
+    /// Return true if the `magic` field signifies big-endian.
+    fn is_big_endian(&self) -> bool;
+
+    /// Return true if the `magic` field signifies little-endian.
+    fn is_little_endian(&self) -> bool;
+
+    fn magic(&self) -> u32;
+    fn cputype(&self, endian: Self::Endian) -> u32;
+    fn cpusubtype(&self, endian: Self::Endian) -> u32;
+    fn filetype(&self, endian: Self::Endian) -> u32;
+    fn ncmds(&self, endian: Self::Endian) -> u32;
+    fn sizeofcmds(&self, endian: Self::Endian) -> u32;
+    fn flags(&self, endian: Self::Endian) -> u32;
+
+    // Provided methods.
+
+    /// Read the file header.
+    ///
+    /// Also checks that the magic field in the file header is a supported format.
+    fn parse<'data, R: ReadRef<'data>>(data: R, offset: u64) -> read::Result<&'data Self> {
+        let header = data
+            .read_at::<Self>(offset)
+            .read_error("Invalid Mach-O header size or alignment")?;
+        if !header.is_supported() {
+            return Err(Error("Unsupported Mach-O header"));
+        }
+        Ok(header)
+    }
+
+    fn is_supported(&self) -> bool {
+        self.is_little_endian() || self.is_big_endian()
+    }
+
+    fn endian(&self) -> Result<Self::Endian> {
+        Self::Endian::from_big_endian(self.is_big_endian()).read_error("Unsupported Mach-O endian")
+    }
+
+    fn load_commands<'data, R: ReadRef<'data>>(
+        &self,
+        endian: Self::Endian,
+        data: R,
+        header_offset: u64,
+    ) -> Result<LoadCommandIterator<'data, Self::Endian>> {
+        let data = data
+            .read_bytes_at(
+                header_offset + mem::size_of::<Self>() as u64,
+                self.sizeofcmds(endian).into(),
+            )
+            .read_error("Invalid Mach-O load command table size")?;
+        Ok(LoadCommandIterator::new(endian, data, self.ncmds(endian)))
+    }
+
+    /// Return the UUID from the `LC_UUID` load command, if one is present.
+    fn uuid<'data, R: ReadRef<'data>>(
+        &self,
+        endian: Self::Endian,
+        data: R,
+        header_offset: u64,
+    ) -> Result<Option<[u8; 16]>> {
+        let mut commands = self.load_commands(endian, data, header_offset)?;
+        while let Some(command) = commands.next()? {
+            if let Ok(Some(uuid)) = command.uuid() {
+                return Ok(Some(uuid.uuid));
+            }
+        }
+        Ok(None)
+    }
+}
+
+impl<Endian: endian::Endian> MachHeader for macho::MachHeader32<Endian> {
+    type Word = u32;
+    type Endian = Endian;
+    type Segment = macho::SegmentCommand32<Endian>;
+    type Section = macho::Section32<Endian>;
+    type Nlist = macho::Nlist32<Endian>;
+
+    fn is_type_64(&self) -> bool {
+        false
+    }
+
+    fn is_big_endian(&self) -> bool {
+        self.magic() == macho::MH_MAGIC
+    }
+
+    fn is_little_endian(&self) -> bool {
+        self.magic() == macho::MH_CIGAM
+    }
+
+    fn magic(&self) -> u32 {
+        self.magic.get(BigEndian)
+    }
+
+    fn cputype(&self, endian: Self::Endian) -> u32 {
+        self.cputype.get(endian)
+    }
+
+    fn cpusubtype(&self, endian: Self::Endian) -> u32 {
+        self.cpusubtype.get(endian)
+    }
+
+    fn filetype(&self, endian: Self::Endian) -> u32 {
+        self.filetype.get(endian)
+    }
+
+    fn ncmds(&self, endian: Self::Endian) -> u32 {
+        self.ncmds.get(endian)
+    }
+
+    fn sizeofcmds(&self, endian: Self::Endian) -> u32 {
+        self.sizeofcmds.get(endian)
+    }
+
+    fn flags(&self, endian: Self::Endian) -> u32 {
+        self.flags.get(endian)
+    }
+}
+
+impl<Endian: endian::Endian> MachHeader for macho::MachHeader64<Endian> {
+    type Word = u64;
+    type Endian = Endian;
+    type Segment = macho::SegmentCommand64<Endian>;
+    type Section = macho::Section64<Endian>;
+    type Nlist = macho::Nlist64<Endian>;
+
+    fn is_type_64(&self) -> bool {
+        true
+    }
+
+    fn is_big_endian(&self) -> bool {
+        self.magic() == macho::MH_MAGIC_64
+    }
+
+    fn is_little_endian(&self) -> bool {
+        self.magic() == macho::MH_CIGAM_64
+    }
+
+    fn magic(&self) -> u32 {
+        self.magic.get(BigEndian)
+    }
+
+    fn cputype(&self, endian: Self::Endian) -> u32 {
+        self.cputype.get(endian)
+    }
+
+    fn cpusubtype(&self, endian: Self::Endian) -> u32 {
+        self.cpusubtype.get(endian)
+    }
+
+    fn filetype(&self, endian: Self::Endian) -> u32 {
+        self.filetype.get(endian)
+    }
+
+    fn ncmds(&self, endian: Self::Endian) -> u32 {
+        self.ncmds.get(endian)
+    }
+
+    fn sizeofcmds(&self, endian: Self::Endian) -> u32 {
+        self.sizeofcmds.get(endian)
+    }
+
+    fn flags(&self, endian: Self::Endian) -> u32 {
+        self.flags.get(endian)
+    }
+}
diff --git a/third_party/rust/object/src/read/macho/load_command.rs b/third_party/rust/object/src/read/macho/load_command.rs
new file mode 100644
index 0000000000..e9af89d8bf
--- /dev/null
+++ b/third_party/rust/object/src/read/macho/load_command.rs
@@ -0,0 +1,373 @@
+use core::marker::PhantomData;
+use core::mem;
+
+use crate::endian::Endian;
+use crate::macho;
+use crate::pod::Pod;
+use crate::read::macho::{MachHeader, SymbolTable};
+use crate::read::{Bytes, Error, ReadError, ReadRef, Result, StringTable};
+
+/// An iterator over the load commands of a `MachHeader`.
+#[derive(Debug, Default, Clone, Copy)]
+pub struct LoadCommandIterator<'data, E: Endian> {
+    endian: E,
+    data: Bytes<'data>,
+    ncmds: u32,
+}
+
+impl<'data, E: Endian> LoadCommandIterator<'data, E> {
+    pub(super) fn new(endian: E, data: &'data [u8], ncmds: u32) -> Self {
+        LoadCommandIterator {
+            endian,
+            data: Bytes(data),
+            ncmds,
+        }
+    }
+
+    /// Return the next load command.
+    pub fn next(&mut self) -> Result<Option<LoadCommandData<'data, E>>> {
+        if self.ncmds == 0 {
+            return Ok(None);
+        }
+        let header = self
+            .data
+            .read_at::<macho::LoadCommand<E>>(0)
+            .read_error("Invalid Mach-O load command header")?;
+        let cmd = header.cmd.get(self.endian);
+        let cmdsize = header.cmdsize.get(self.endian) as usize;
+        if cmdsize < mem::size_of::<macho::LoadCommand<E>>() {
+            return Err(Error("Invalid Mach-O load command size"));
+        }
+        let data = self
+            .data
+            .read_bytes(cmdsize)
+            .read_error("Invalid Mach-O load command size")?;
+        self.ncmds -= 1;
+        Ok(Some(LoadCommandData {
+            cmd,
+            data,
+            marker: Default::default(),
+        }))
+    }
+}
+
+/// The data for a `LoadCommand`.
+#[derive(Debug, Clone, Copy)]
+pub struct LoadCommandData<'data, E: Endian> {
+    cmd: u32,
+    // Includes the header.
+    data: Bytes<'data>,
+    marker: PhantomData<E>,
+}
+
+impl<'data, E: Endian> LoadCommandData<'data, E> {
+    /// Return the `cmd` field of the `LoadCommand`.
+    ///
+    /// This is one of the `LC_` constants.
+    pub fn cmd(&self) -> u32 {
+        self.cmd
+    }
+
+    /// Return the `cmdsize` field of the `LoadCommand`.
+    pub fn cmdsize(&self) -> u32 {
+        self.data.len() as u32
+    }
+
+    /// Parse the data as the given type.
+    #[inline]
+    pub fn data<T: Pod>(&self) -> Result<&'data T> {
+        self.data
+            .read_at(0)
+            .read_error("Invalid Mach-O command size")
+    }
+
+    /// Raw bytes of this LoadCommand structure.
+    pub fn raw_data(&self) -> &'data [u8] {
+        self.data.0
+    }
+
+    /// Parse a load command string value.
+    ///
+    /// Strings used by load commands are specified by offsets that are
+    /// relative to the load command header.
+    pub fn string(&self, endian: E, s: macho::LcStr<E>) -> Result<&'data [u8]> {
+        self.data
+            .read_string_at(s.offset.get(endian) as usize)
+            .read_error("Invalid load command string offset")
+    }
+
+    /// Parse the command data according to the `cmd` field.
+    pub fn variant(&self) -> Result<LoadCommandVariant<'data, E>> {
+        Ok(match self.cmd {
+            macho::LC_SEGMENT => {
+                let mut data = self.data;
+                let segment = data.read().read_error("Invalid Mach-O command size")?;
+                LoadCommandVariant::Segment32(segment, data.0)
+            }
+            macho::LC_SYMTAB => LoadCommandVariant::Symtab(self.data()?),
+            macho::LC_THREAD | macho::LC_UNIXTHREAD => {
+                let mut data = self.data;
+                let thread = data.read().read_error("Invalid Mach-O command size")?;
+                LoadCommandVariant::Thread(thread, data.0)
+            }
+            macho::LC_DYSYMTAB => LoadCommandVariant::Dysymtab(self.data()?),
+            macho::LC_LOAD_DYLIB
+            | macho::LC_LOAD_WEAK_DYLIB
+            | macho::LC_REEXPORT_DYLIB
+            | macho::LC_LAZY_LOAD_DYLIB
+            | macho::LC_LOAD_UPWARD_DYLIB => LoadCommandVariant::Dylib(self.data()?),
+            macho::LC_ID_DYLIB => LoadCommandVariant::IdDylib(self.data()?),
+            macho::LC_LOAD_DYLINKER => LoadCommandVariant::LoadDylinker(self.data()?),
+            macho::LC_ID_DYLINKER => LoadCommandVariant::IdDylinker(self.data()?),
+            macho::LC_PREBOUND_DYLIB => LoadCommandVariant::PreboundDylib(self.data()?),
+            macho::LC_ROUTINES => LoadCommandVariant::Routines32(self.data()?),
+            macho::LC_SUB_FRAMEWORK => LoadCommandVariant::SubFramework(self.data()?),
+            macho::LC_SUB_UMBRELLA => LoadCommandVariant::SubUmbrella(self.data()?),
+            macho::LC_SUB_CLIENT => LoadCommandVariant::SubClient(self.data()?),
+            macho::LC_SUB_LIBRARY => LoadCommandVariant::SubLibrary(self.data()?),
+            macho::LC_TWOLEVEL_HINTS => LoadCommandVariant::TwolevelHints(self.data()?),
+            macho::LC_PREBIND_CKSUM => LoadCommandVariant::PrebindCksum(self.data()?),
+            macho::LC_SEGMENT_64 => {
+                let mut data = self.data;
+                let segment = data.read().read_error("Invalid Mach-O command size")?;
+                LoadCommandVariant::Segment64(segment, data.0)
+            }
+            macho::LC_ROUTINES_64 => LoadCommandVariant::Routines64(self.data()?),
+            macho::LC_UUID => LoadCommandVariant::Uuid(self.data()?),
+            macho::LC_RPATH => LoadCommandVariant::Rpath(self.data()?),
+            macho::LC_CODE_SIGNATURE
+            | macho::LC_SEGMENT_SPLIT_INFO
+            | macho::LC_FUNCTION_STARTS
+            | macho::LC_DATA_IN_CODE
+            | macho::LC_DYLIB_CODE_SIGN_DRS
+            | macho::LC_LINKER_OPTIMIZATION_HINT
+            | macho::LC_DYLD_EXPORTS_TRIE
+            | macho::LC_DYLD_CHAINED_FIXUPS => LoadCommandVariant::LinkeditData(self.data()?),
+            macho::LC_ENCRYPTION_INFO => LoadCommandVariant::EncryptionInfo32(self.data()?),
+            macho::LC_DYLD_INFO | macho::LC_DYLD_INFO_ONLY => {
+                LoadCommandVariant::DyldInfo(self.data()?)
+            }
+            macho::LC_VERSION_MIN_MACOSX
+            | macho::LC_VERSION_MIN_IPHONEOS
+            | macho::LC_VERSION_MIN_TVOS
+            | macho::LC_VERSION_MIN_WATCHOS => LoadCommandVariant::VersionMin(self.data()?),
+            macho::LC_DYLD_ENVIRONMENT => LoadCommandVariant::DyldEnvironment(self.data()?),
+            macho::LC_MAIN => LoadCommandVariant::EntryPoint(self.data()?),
+            macho::LC_SOURCE_VERSION => LoadCommandVariant::SourceVersion(self.data()?),
+            macho::LC_ENCRYPTION_INFO_64 => LoadCommandVariant::EncryptionInfo64(self.data()?),
+            macho::LC_LINKER_OPTION => LoadCommandVariant::LinkerOption(self.data()?),
+            macho::LC_NOTE => LoadCommandVariant::Note(self.data()?),
+            macho::LC_BUILD_VERSION => LoadCommandVariant::BuildVersion(self.data()?),
+            macho::LC_FILESET_ENTRY => LoadCommandVariant::FilesetEntry(self.data()?),
+            _ => LoadCommandVariant::Other,
+        })
+    }
+
+    /// Try to parse this command as a `SegmentCommand32`.
+    ///
+    /// Returns the segment command and the data containing the sections.
+    pub fn segment_32(self) -> Result<Option<(&'data macho::SegmentCommand32<E>, &'data [u8])>> {
+        if self.cmd == macho::LC_SEGMENT {
+            let mut data = self.data;
+            let segment = data.read().read_error("Invalid Mach-O command size")?;
+            Ok(Some((segment, data.0)))
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Try to parse this command as a `SymtabCommand`.
+    ///
+    /// Returns the segment command and the data containing the sections.
+    pub fn symtab(self) -> Result<Option<&'data macho::SymtabCommand<E>>> {
+        if self.cmd == macho::LC_SYMTAB {
+            Some(self.data()).transpose()
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Try to parse this command as a `DysymtabCommand`.
+    pub fn dysymtab(self) -> Result<Option<&'data macho::DysymtabCommand<E>>> {
+        if self.cmd == macho::LC_DYSYMTAB {
+            Some(self.data()).transpose()
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Try to parse this command as a `DylibCommand`.
+    pub fn dylib(self) -> Result<Option<&'data macho::DylibCommand<E>>> {
+        if self.cmd == macho::LC_LOAD_DYLIB
+            || self.cmd == macho::LC_LOAD_WEAK_DYLIB
+            || self.cmd == macho::LC_REEXPORT_DYLIB
+            || self.cmd == macho::LC_LAZY_LOAD_DYLIB
+            || self.cmd == macho::LC_LOAD_UPWARD_DYLIB
+        {
+            Some(self.data()).transpose()
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Try to parse this command as a `UuidCommand`.
+    pub fn uuid(self) -> Result<Option<&'data macho::UuidCommand<E>>> {
+        if self.cmd == macho::LC_UUID {
+            Some(self.data()).transpose()
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Try to parse this command as a `SegmentCommand64`.
+    pub fn segment_64(self) -> Result<Option<(&'data macho::SegmentCommand64<E>, &'data [u8])>> {
+        if self.cmd == macho::LC_SEGMENT_64 {
+            let mut data = self.data;
+            let command = data.read().read_error("Invalid Mach-O command size")?;
+            Ok(Some((command, data.0)))
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Try to parse this command as a `DyldInfoCommand`.
+    pub fn dyld_info(self) -> Result<Option<&'data macho::DyldInfoCommand<E>>> {
+        if self.cmd == macho::LC_DYLD_INFO || self.cmd == macho::LC_DYLD_INFO_ONLY {
+            Some(self.data()).transpose()
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Try to parse this command as an `EntryPointCommand`.
+    pub fn entry_point(self) -> Result<Option<&'data macho::EntryPointCommand<E>>> {
+        if self.cmd == macho::LC_MAIN {
+            Some(self.data()).transpose()
+        } else {
+            Ok(None)
+        }
+    }
+}
+
+/// A `LoadCommand` that has been interpreted according to its `cmd` field.
+#[derive(Debug, Clone, Copy)]
+#[non_exhaustive]
+pub enum LoadCommandVariant<'data, E: Endian> {
+    /// `LC_SEGMENT`
+    Segment32(&'data macho::SegmentCommand32<E>, &'data [u8]),
+    /// `LC_SYMTAB`
+    Symtab(&'data macho::SymtabCommand<E>),
+    // obsolete: `LC_SYMSEG`
+    //Symseg(&'data macho::SymsegCommand<E>),
+    /// `LC_THREAD` or `LC_UNIXTHREAD`
+    Thread(&'data macho::ThreadCommand<E>, &'data [u8]),
+    // obsolete: `LC_IDFVMLIB` or `LC_LOADFVMLIB`
+    //Fvmlib(&'data macho::FvmlibCommand<E>),
+    // obsolete: `LC_IDENT`
+    //Ident(&'data macho::IdentCommand<E>),
+    // internal: `LC_FVMFILE`
+    //Fvmfile(&'data macho::FvmfileCommand<E>),
+    // internal: `LC_PREPAGE`
+    /// `LC_DYSYMTAB`
+    Dysymtab(&'data macho::DysymtabCommand<E>),
+    /// `LC_LOAD_DYLIB`, `LC_LOAD_WEAK_DYLIB`, `LC_REEXPORT_DYLIB`,
+    /// `LC_LAZY_LOAD_DYLIB`, or `LC_LOAD_UPWARD_DYLIB`
+    Dylib(&'data macho::DylibCommand<E>),
+    /// `LC_ID_DYLIB`
+    IdDylib(&'data macho::DylibCommand<E>),
+    /// `LC_LOAD_DYLINKER`
+    LoadDylinker(&'data macho::DylinkerCommand<E>),
+    /// `LC_ID_DYLINKER`
+    IdDylinker(&'data macho::DylinkerCommand<E>),
+    /// `LC_PREBOUND_DYLIB`
+    PreboundDylib(&'data macho::PreboundDylibCommand<E>),
+    /// `LC_ROUTINES`
+    Routines32(&'data macho::RoutinesCommand32<E>),
+    /// `LC_SUB_FRAMEWORK`
+    SubFramework(&'data macho::SubFrameworkCommand<E>),
+    /// `LC_SUB_UMBRELLA`
+    SubUmbrella(&'data macho::SubUmbrellaCommand<E>),
+    /// `LC_SUB_CLIENT`
+    SubClient(&'data macho::SubClientCommand<E>),
+    /// `LC_SUB_LIBRARY`
+    SubLibrary(&'data macho::SubLibraryCommand<E>),
+    /// `LC_TWOLEVEL_HINTS`
+    TwolevelHints(&'data macho::TwolevelHintsCommand<E>),
+    /// `LC_PREBIND_CKSUM`
+    PrebindCksum(&'data macho::PrebindCksumCommand<E>),
+    /// `LC_SEGMENT_64`
+    Segment64(&'data macho::SegmentCommand64<E>, &'data [u8]),
+    /// `LC_ROUTINES_64`
+    Routines64(&'data macho::RoutinesCommand64<E>),
+    /// `LC_UUID`
+    Uuid(&'data macho::UuidCommand<E>),
+    /// `LC_RPATH`
+    Rpath(&'data macho::RpathCommand<E>),
+    /// `LC_CODE_SIGNATURE`, `LC_SEGMENT_SPLIT_INFO`, `LC_FUNCTION_STARTS`,
+    /// `LC_DATA_IN_CODE`, `LC_DYLIB_CODE_SIGN_DRS`, `LC_LINKER_OPTIMIZATION_HINT`,
+    /// `LC_DYLD_EXPORTS_TRIE`, or `LC_DYLD_CHAINED_FIXUPS`.
+    LinkeditData(&'data macho::LinkeditDataCommand<E>),
+    /// `LC_ENCRYPTION_INFO`
+    EncryptionInfo32(&'data macho::EncryptionInfoCommand32<E>),
+    /// `LC_DYLD_INFO` or `LC_DYLD_INFO_ONLY`
+    DyldInfo(&'data macho::DyldInfoCommand<E>),
+    /// `LC_VERSION_MIN_MACOSX`, `LC_VERSION_MIN_IPHONEOS`, `LC_VERSION_MIN_WATCHOS`,
+    /// or `LC_VERSION_MIN_TVOS`
+    VersionMin(&'data macho::VersionMinCommand<E>),
+    /// `LC_DYLD_ENVIRONMENT`
+    DyldEnvironment(&'data macho::DylinkerCommand<E>),
+    /// `LC_MAIN`
+    EntryPoint(&'data macho::EntryPointCommand<E>),
+    /// `LC_SOURCE_VERSION`
+    SourceVersion(&'data macho::SourceVersionCommand<E>),
+    /// `LC_ENCRYPTION_INFO_64`
+    EncryptionInfo64(&'data macho::EncryptionInfoCommand64<E>),
+    /// `LC_LINKER_OPTION`
+    LinkerOption(&'data macho::LinkerOptionCommand<E>),
+    /// `LC_NOTE`
+    Note(&'data macho::NoteCommand<E>),
+    /// `LC_BUILD_VERSION`
+    BuildVersion(&'data macho::BuildVersionCommand<E>),
+    /// `LC_FILESET_ENTRY`
+    FilesetEntry(&'data macho::FilesetEntryCommand<E>),
+    /// An unrecognized or obsolete load command.
+    Other,
+}
+
+impl<E: Endian> macho::SymtabCommand<E> {
+    /// Return the symbol table that this command references.
+    pub fn symbols<'data, Mach: MachHeader<Endian = E>, R: ReadRef<'data>>(
+        &self,
+        endian: E,
+        data: R,
+    ) -> Result<SymbolTable<'data, Mach, R>> {
+        let symbols = data
+            .read_slice_at(
+                self.symoff.get(endian).into(),
+                self.nsyms.get(endian) as usize,
+            )
+            .read_error("Invalid Mach-O symbol table offset or size")?;
+        let str_start: u64 = self.stroff.get(endian).into();
+        let str_end = str_start
+            .checked_add(self.strsize.get(endian).into())
+            .read_error("Invalid Mach-O string table length")?;
+        let strings = StringTable::new(data, str_start, str_end);
+        Ok(SymbolTable::new(symbols, strings))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::LittleEndian;
+
+    #[test]
+    fn cmd_size_invalid() {
+        let mut commands = LoadCommandIterator::new(LittleEndian, &[0; 8], 10);
+        assert!(commands.next().is_err());
+        let mut commands = LoadCommandIterator::new(LittleEndian, &[0, 0, 0, 0, 7, 0, 0, 0, 0], 10);
+        assert!(commands.next().is_err());
+        let mut commands = LoadCommandIterator::new(LittleEndian, &[0, 0, 0, 0, 8, 0, 0, 0, 0], 10);
+        assert!(commands.next().is_ok());
+    }
+}
diff --git a/third_party/rust/object/src/read/macho/mod.rs b/third_party/rust/object/src/read/macho/mod.rs
new file mode 100644
index 0000000000..f07ed581b6
--- /dev/null
+++ b/third_party/rust/object/src/read/macho/mod.rs
@@ -0,0 +1,30 @@
+//! Support for reading Mach-O files.
+//!
+//! Defines traits to abstract over the difference between 32-bit and 64-bit
+//! Mach-O files, and implements read functionality in terms of these traits.
+//!
+//! Also provides `MachOFile` and related types which implement the `Object` trait.
+
+mod dyld_cache;
+pub use dyld_cache::*;
+
+mod fat;
+pub use fat::*;
+
+mod file;
+pub use file::*;
+
+mod load_command;
+pub use load_command::*;
+
+mod segment;
+pub use segment::*;
+
+mod section;
+pub use section::*;
+
+mod symbol;
+pub use symbol::*;
+
+mod relocation;
+pub use relocation::*;
diff --git a/third_party/rust/object/src/read/macho/relocation.rs b/third_party/rust/object/src/read/macho/relocation.rs
new file mode 100644
index 0000000000..18e22ef706
--- /dev/null
+++ b/third_party/rust/object/src/read/macho/relocation.rs
@@ -0,0 +1,127 @@
+use core::{fmt, slice};
+
+use crate::endian::Endianness;
+use crate::macho;
+use crate::read::{
+    ReadRef, Relocation, RelocationEncoding, RelocationKind, RelocationTarget, SectionIndex,
+    SymbolIndex,
+};
+
+use super::{MachHeader, MachOFile};
+
+/// An iterator over the relocations in a `MachOSection32`.
+pub type MachORelocationIterator32<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachORelocationIterator<'data, 'file, macho::MachHeader32<Endian>, R>;
+/// An iterator over the relocations in a `MachOSection64`.
+pub type MachORelocationIterator64<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachORelocationIterator<'data, 'file, macho::MachHeader64<Endian>, R>;
+
+/// An iterator over the relocations in a `MachOSection`.
+pub struct MachORelocationIterator<'data, 'file, Mach, R = &'data [u8]>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    pub(super) file: &'file MachOFile<'data, Mach, R>,
+    pub(super) relocations: slice::Iter<'data, macho::Relocation<Mach::Endian>>,
+}
+
+impl<'data, 'file, Mach, R> Iterator for MachORelocationIterator<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    type Item = (u64, Relocation);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        loop {
+            let reloc = self.relocations.next()?;
+            let endian = self.file.endian;
+            let cputype = self.file.header.cputype(endian);
+            if reloc.r_scattered(endian, cputype) {
+                // FIXME: handle scattered relocations
+                // We need to add `RelocationTarget::Address` for this.
+                continue;
+            }
+            let reloc = reloc.info(self.file.endian);
+            let mut encoding = RelocationEncoding::Generic;
+            let kind = match cputype {
+                macho::CPU_TYPE_ARM => match (reloc.r_type, reloc.r_pcrel) {
+                    (macho::ARM_RELOC_VANILLA, false) => RelocationKind::Absolute,
+                    _ => RelocationKind::MachO {
+                        value: reloc.r_type,
+                        relative: reloc.r_pcrel,
+                    },
+                },
+                macho::CPU_TYPE_ARM64 | macho::CPU_TYPE_ARM64_32 => {
+                    match (reloc.r_type, reloc.r_pcrel) {
+                        (macho::ARM64_RELOC_UNSIGNED, false) => RelocationKind::Absolute,
+                        _ => RelocationKind::MachO {
+                            value: reloc.r_type,
+                            relative: reloc.r_pcrel,
+                        },
+                    }
+                }
+                macho::CPU_TYPE_X86 => match (reloc.r_type, reloc.r_pcrel) {
+                    (macho::GENERIC_RELOC_VANILLA, false) => RelocationKind::Absolute,
+                    _ => RelocationKind::MachO {
+                        value: reloc.r_type,
+                        relative: reloc.r_pcrel,
+                    },
+                },
+                macho::CPU_TYPE_X86_64 => match (reloc.r_type, reloc.r_pcrel) {
+                    (macho::X86_64_RELOC_UNSIGNED, false) => RelocationKind::Absolute,
+                    (macho::X86_64_RELOC_SIGNED, true) => {
+                        encoding = RelocationEncoding::X86RipRelative;
+                        RelocationKind::Relative
+                    }
+                    (macho::X86_64_RELOC_BRANCH, true) => {
+                        encoding = RelocationEncoding::X86Branch;
+                        RelocationKind::Relative
+                    }
+                    (macho::X86_64_RELOC_GOT, true) => RelocationKind::GotRelative,
+                    (macho::X86_64_RELOC_GOT_LOAD, true) => {
+                        encoding = RelocationEncoding::X86RipRelativeMovq;
+                        RelocationKind::GotRelative
+                    }
+                    _ => RelocationKind::MachO {
+                        value: reloc.r_type,
+                        relative: reloc.r_pcrel,
+                    },
+                },
+                _ => RelocationKind::MachO {
+                    value: reloc.r_type,
+                    relative: reloc.r_pcrel,
+                },
+            };
+            let size = 8 << reloc.r_length;
+            let target = if reloc.r_extern {
+                RelocationTarget::Symbol(SymbolIndex(reloc.r_symbolnum as usize))
+            } else {
+                RelocationTarget::Section(SectionIndex(reloc.r_symbolnum as usize))
+            };
+            let addend = if reloc.r_pcrel { -4 } else { 0 };
+            return Some((
+                reloc.r_address as u64,
+                Relocation {
+                    kind,
+                    encoding,
+                    size,
+                    target,
+                    addend,
+                    implicit_addend: true,
+                },
+            ));
+        }
+    }
+}
+
+impl<'data, 'file, Mach, R> fmt::Debug for MachORelocationIterator<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("MachORelocationIterator").finish()
+    }
+}
diff --git a/third_party/rust/object/src/read/macho/section.rs b/third_party/rust/object/src/read/macho/section.rs
new file mode 100644
index 0000000000..f43a5b83d4
--- /dev/null
+++ b/third_party/rust/object/src/read/macho/section.rs
@@ -0,0 +1,387 @@
+use core::fmt::Debug;
+use core::{fmt, result, slice, str};
+
+use crate::endian::{self, Endianness};
+use crate::macho;
+use crate::pod::Pod;
+use crate::read::{
+    self, CompressedData, CompressedFileRange, ObjectSection, ReadError, ReadRef, Result,
+    SectionFlags, SectionIndex, SectionKind,
+};
+
+use super::{MachHeader, MachOFile, MachORelocationIterator};
+
+/// An iterator over the sections of a `MachOFile32`.
+pub type MachOSectionIterator32<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOSectionIterator<'data, 'file, macho::MachHeader32<Endian>, R>;
+/// An iterator over the sections of a `MachOFile64`.
+pub type MachOSectionIterator64<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOSectionIterator<'data, 'file, macho::MachHeader64<Endian>, R>;
+
+/// An iterator over the sections of a `MachOFile`.
+pub struct MachOSectionIterator<'data, 'file, Mach, R = &'data [u8]>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    pub(super) file: &'file MachOFile<'data, Mach, R>,
+    pub(super) iter: slice::Iter<'file, MachOSectionInternal<'data, Mach>>,
+}
+
+impl<'data, 'file, Mach, R> fmt::Debug for MachOSectionIterator<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        // It's painful to do much better than this
+        f.debug_struct("MachOSectionIterator").finish()
+    }
+}
+
+impl<'data, 'file, Mach, R> Iterator for MachOSectionIterator<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    type Item = MachOSection<'data, 'file, Mach, R>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.iter.next().map(|&internal| MachOSection {
+            file: self.file,
+            internal,
+        })
+    }
+}
+
+/// A section of a `MachOFile32`.
+pub type MachOSection32<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOSection<'data, 'file, macho::MachHeader32<Endian>, R>;
+/// A section of a `MachOFile64`.
+pub type MachOSection64<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOSection<'data, 'file, macho::MachHeader64<Endian>, R>;
+
+/// A section of a `MachOFile`.
+#[derive(Debug)]
+pub struct MachOSection<'data, 'file, Mach, R = &'data [u8]>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    pub(super) file: &'file MachOFile<'data, Mach, R>,
+    pub(super) internal: MachOSectionInternal<'data, Mach>,
+}
+
+impl<'data, 'file, Mach, R> MachOSection<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    fn bytes(&self) -> Result<&'data [u8]> {
+        let segment_index = self.internal.segment_index;
+        let segment = self.file.segment_internal(segment_index)?;
+        self.internal
+            .section
+            .data(self.file.endian, segment.data)
+            .read_error("Invalid Mach-O section size or offset")
+    }
+}
+
+impl<'data, 'file, Mach, R> read::private::Sealed for MachOSection<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+}
+
+impl<'data, 'file, Mach, R> ObjectSection<'data> for MachOSection<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    type RelocationIterator = MachORelocationIterator<'data, 'file, Mach, R>;
+
+    #[inline]
+    fn index(&self) -> SectionIndex {
+        self.internal.index
+    }
+
+    #[inline]
+    fn address(&self) -> u64 {
+        self.internal.section.addr(self.file.endian).into()
+    }
+
+    #[inline]
+    fn size(&self) -> u64 {
+        self.internal.section.size(self.file.endian).into()
+    }
+
+    #[inline]
+    fn align(&self) -> u64 {
+        let align = self.internal.section.align(self.file.endian);
+        if align < 64 {
+            1 << align
+        } else {
+            0
+        }
+    }
+
+    #[inline]
+    fn file_range(&self) -> Option<(u64, u64)> {
+        self.internal.section.file_range(self.file.endian)
+    }
+
+    #[inline]
+    fn data(&self) -> Result<&'data [u8]> {
+        self.bytes()
+    }
+
+    fn data_range(&self, address: u64, size: u64) -> Result<Option<&'data [u8]>> {
+        Ok(read::util::data_range(
+            self.bytes()?,
+            self.address(),
+            address,
+            size,
+        ))
+    }
+
+    #[inline]
+    fn compressed_file_range(&self) -> Result<CompressedFileRange> {
+        Ok(CompressedFileRange::none(self.file_range()))
+    }
+
+    #[inline]
+    fn compressed_data(&self) -> Result<CompressedData<'data>> {
+        self.data().map(CompressedData::none)
+    }
+
+    #[inline]
+    fn name_bytes(&self) -> Result<&[u8]> {
+        Ok(self.internal.section.name())
+    }
+
+    #[inline]
+    fn name(&self) -> Result<&str> {
+        str::from_utf8(self.internal.section.name())
+            .ok()
+            .read_error("Non UTF-8 Mach-O section name")
+    }
+
+    #[inline]
+    fn segment_name_bytes(&self) -> Result<Option<&[u8]>> {
+        Ok(Some(self.internal.section.segment_name()))
+    }
+
+    #[inline]
+    fn segment_name(&self) -> Result<Option<&str>> {
+        Ok(Some(
+            str::from_utf8(self.internal.section.segment_name())
+                .ok()
+                .read_error("Non UTF-8 Mach-O segment name")?,
+        ))
+    }
+
+    fn kind(&self) -> SectionKind {
+        self.internal.kind
+    }
+
+    fn relocations(&self) -> MachORelocationIterator<'data, 'file, Mach, R> {
+        MachORelocationIterator {
+            file: self.file,
+            relocations: self
+                .internal
+                .section
+                .relocations(self.file.endian, self.file.data)
+                .unwrap_or(&[])
+                .iter(),
+        }
+    }
+
+    fn flags(&self) -> SectionFlags {
+        SectionFlags::MachO {
+            flags: self.internal.section.flags(self.file.endian),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+pub(super) struct MachOSectionInternal<'data, Mach: MachHeader> {
+    pub index: SectionIndex,
+    pub segment_index: usize,
+    pub kind: SectionKind,
+    pub section: &'data Mach::Section,
+}
+
+impl<'data, Mach: MachHeader> MachOSectionInternal<'data, Mach> {
+    pub(super) fn parse(
+        index: SectionIndex,
+        segment_index: usize,
+        section: &'data Mach::Section,
+    ) -> Self {
+        // TODO: we don't validate flags, should we?
+        let kind = match (section.segment_name(), section.name()) {
+            (b"__TEXT", b"__text") => SectionKind::Text,
+            (b"__TEXT", b"__const") => SectionKind::ReadOnlyData,
+            (b"__TEXT", b"__cstring") => SectionKind::ReadOnlyString,
+            (b"__TEXT", b"__literal4") => SectionKind::ReadOnlyData,
+            (b"__TEXT", b"__literal8") => SectionKind::ReadOnlyData,
+            (b"__TEXT", b"__literal16") => SectionKind::ReadOnlyData,
+            (b"__TEXT", b"__eh_frame") => SectionKind::ReadOnlyData,
+            (b"__TEXT", b"__gcc_except_tab") => SectionKind::ReadOnlyData,
+            (b"__DATA", b"__data") => SectionKind::Data,
+            (b"__DATA", b"__const") => SectionKind::ReadOnlyData,
+            (b"__DATA", b"__bss") => SectionKind::UninitializedData,
+            (b"__DATA", b"__common") => SectionKind::Common,
+            (b"__DATA", b"__thread_data") => SectionKind::Tls,
+            (b"__DATA", b"__thread_bss") => SectionKind::UninitializedTls,
+            (b"__DATA", b"__thread_vars") => SectionKind::TlsVariables,
+            (b"__DWARF", _) => SectionKind::Debug,
+            _ => SectionKind::Unknown,
+        };
+        MachOSectionInternal {
+            index,
+            segment_index,
+            kind,
+            section,
+        }
+    }
+}
+
+/// A trait for generic access to `Section32` and `Section64`.
+#[allow(missing_docs)]
+pub trait Section: Debug + Pod {
+    type Word: Into<u64>;
+    type Endian: endian::Endian;
+
+    fn sectname(&self) -> &[u8; 16];
+    fn segname(&self) -> &[u8; 16];
+    fn addr(&self, endian: Self::Endian) -> Self::Word;
+    fn size(&self, endian: Self::Endian) -> Self::Word;
+    fn offset(&self, endian: Self::Endian) -> u32;
+    fn align(&self, endian: Self::Endian) -> u32;
+    fn reloff(&self, endian: Self::Endian) -> u32;
+    fn nreloc(&self, endian: Self::Endian) -> u32;
+    fn flags(&self, endian: Self::Endian) -> u32;
+
+    /// Return the `sectname` bytes up until the null terminator.
+    fn name(&self) -> &[u8] {
+        let sectname = &self.sectname()[..];
+        match memchr::memchr(b'\0', sectname) {
+            Some(end) => &sectname[..end],
+            None => sectname,
+        }
+    }
+
+    /// Return the `segname` bytes up until the null terminator.
+    fn segment_name(&self) -> &[u8] {
+        let segname = &self.segname()[..];
+        match memchr::memchr(b'\0', segname) {
+            Some(end) => &segname[..end],
+            None => segname,
+        }
+    }
+
+    /// Return the offset and size of the section in the file.
+    ///
+    /// Returns `None` for sections that have no data in the file.
+    fn file_range(&self, endian: Self::Endian) -> Option<(u64, u64)> {
+        match self.flags(endian) & macho::SECTION_TYPE {
+            macho::S_ZEROFILL | macho::S_GB_ZEROFILL | macho::S_THREAD_LOCAL_ZEROFILL => None,
+            _ => Some((self.offset(endian).into(), self.size(endian).into())),
+        }
+    }
+
+    /// Return the section data.
+    ///
+    /// Returns `Ok(&[])` if the section has no data.
+    /// Returns `Err` for invalid values.
+    fn data<'data, R: ReadRef<'data>>(
+        &self,
+        endian: Self::Endian,
+        data: R,
+    ) -> result::Result<&'data [u8], ()> {
+        if let Some((offset, size)) = self.file_range(endian) {
+            data.read_bytes_at(offset, size)
+        } else {
+            Ok(&[])
+        }
+    }
+
+    /// Return the relocation array.
+    ///
+    /// Returns `Err` for invalid values.
+    fn relocations<'data, R: ReadRef<'data>>(
+        &self,
+        endian: Self::Endian,
+        data: R,
+    ) -> Result<&'data [macho::Relocation<Self::Endian>]> {
+        data.read_slice_at(self.reloff(endian).into(), self.nreloc(endian) as usize)
+            .read_error("Invalid Mach-O relocations offset or number")
+    }
+}
+
+impl<Endian: endian::Endian> Section for macho::Section32<Endian> {
+    type Word = u32;
+    type Endian = Endian;
+
+    fn sectname(&self) -> &[u8; 16] {
+        &self.sectname
+    }
+    fn segname(&self) -> &[u8; 16] {
+        &self.segname
+    }
+    fn addr(&self, endian: Self::Endian) -> Self::Word {
+        self.addr.get(endian)
+    }
+    fn size(&self, endian: Self::Endian) -> Self::Word {
+        self.size.get(endian)
+    }
+    fn offset(&self, endian: Self::Endian) -> u32 {
+        self.offset.get(endian)
+    }
+    fn align(&self, endian: Self::Endian) -> u32 {
+        self.align.get(endian)
+    }
+    fn reloff(&self, endian: Self::Endian) -> u32 {
+        self.reloff.get(endian)
+    }
+    fn nreloc(&self, endian: Self::Endian) -> u32 {
+        self.nreloc.get(endian)
+    }
+    fn flags(&self, endian: Self::Endian) -> u32 {
+        self.flags.get(endian)
+    }
+}
+
+impl<Endian: endian::Endian> Section for macho::Section64<Endian> {
+    type Word = u64;
+    type Endian = Endian;
+
+    fn sectname(&self) -> &[u8; 16] {
+        &self.sectname
+    }
+    fn segname(&self) -> &[u8; 16] {
+        &self.segname
+    }
+    fn addr(&self, endian: Self::Endian) -> Self::Word {
+        self.addr.get(endian)
+    }
+    fn size(&self, endian: Self::Endian) -> Self::Word {
+        self.size.get(endian)
+    }
+    fn offset(&self, endian: Self::Endian) -> u32 {
+        self.offset.get(endian)
+    }
+    fn align(&self, endian: Self::Endian) -> u32 {
+        self.align.get(endian)
+    }
+    fn reloff(&self, endian: Self::Endian) -> u32 {
+        self.reloff.get(endian)
+    }
+    fn nreloc(&self, endian: Self::Endian) -> u32 {
+        self.nreloc.get(endian)
+    }
+    fn flags(&self, endian: Self::Endian) -> u32 {
+        self.flags.get(endian)
+    }
+}
diff --git a/third_party/rust/object/src/read/macho/segment.rs b/third_party/rust/object/src/read/macho/segment.rs
new file mode 100644
index 0000000000..01037e1dd4
--- /dev/null
+++ b/third_party/rust/object/src/read/macho/segment.rs
@@ -0,0 +1,301 @@
+use core::fmt::Debug;
+use core::{result, slice, str};
+
+use crate::endian::{self, Endianness};
+use crate::macho;
+use crate::pod::Pod;
+use crate::read::{self, ObjectSegment, ReadError, ReadRef, Result, SegmentFlags};
+
+use super::{LoadCommandData, MachHeader, MachOFile, Section};
+
+/// An iterator over the segments of a `MachOFile32`.
+pub type MachOSegmentIterator32<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOSegmentIterator<'data, 'file, macho::MachHeader32<Endian>, R>;
+/// An iterator over the segments of a `MachOFile64`.
+pub type MachOSegmentIterator64<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOSegmentIterator<'data, 'file, macho::MachHeader64<Endian>, R>;
+
+/// An iterator over the segments of a `MachOFile`.
+#[derive(Debug)]
+pub struct MachOSegmentIterator<'data, 'file, Mach, R = &'data [u8]>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    pub(super) file: &'file MachOFile<'data, Mach, R>,
+    pub(super) iter: slice::Iter<'file, MachOSegmentInternal<'data, Mach, R>>,
+}
+
+impl<'data, 'file, Mach, R> Iterator for MachOSegmentIterator<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    type Item = MachOSegment<'data, 'file, Mach, R>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.iter.next().map(|internal| MachOSegment {
+            file: self.file,
+            internal,
+        })
+    }
+}
+
+/// A segment of a `MachOFile32`.
+pub type MachOSegment32<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOSegment<'data, 'file, macho::MachHeader32<Endian>, R>;
+/// A segment of a `MachOFile64`.
+pub type MachOSegment64<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOSegment<'data, 'file, macho::MachHeader64<Endian>, R>;
+
+/// A segment of a `MachOFile`.
+#[derive(Debug)]
+pub struct MachOSegment<'data, 'file, Mach, R = &'data [u8]>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    file: &'file MachOFile<'data, Mach, R>,
+    internal: &'file MachOSegmentInternal<'data, Mach, R>,
+}
+
+impl<'data, 'file, Mach, R> MachOSegment<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    fn bytes(&self) -> Result<&'data [u8]> {
+        self.internal
+            .segment
+            .data(self.file.endian, self.file.data)
+            .read_error("Invalid Mach-O segment size or offset")
+    }
+}
+
+impl<'data, 'file, Mach, R> read::private::Sealed for MachOSegment<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+}
+
+impl<'data, 'file, Mach, R> ObjectSegment<'data> for MachOSegment<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    #[inline]
+    fn address(&self) -> u64 {
+        self.internal.segment.vmaddr(self.file.endian).into()
+    }
+
+    #[inline]
+    fn size(&self) -> u64 {
+        self.internal.segment.vmsize(self.file.endian).into()
+    }
+
+    #[inline]
+    fn align(&self) -> u64 {
+        // Page size.
+        0x1000
+    }
+
+    #[inline]
+    fn file_range(&self) -> (u64, u64) {
+        self.internal.segment.file_range(self.file.endian)
+    }
+
+    fn data(&self) -> Result<&'data [u8]> {
+        self.bytes()
+    }
+
+    fn data_range(&self, address: u64, size: u64) -> Result<Option<&'data [u8]>> {
+        Ok(read::util::data_range(
+            self.bytes()?,
+            self.address(),
+            address,
+            size,
+        ))
+    }
+
+    #[inline]
+    fn name_bytes(&self) -> Result<Option<&[u8]>> {
+        Ok(Some(self.internal.segment.name()))
+    }
+
+    #[inline]
+    fn name(&self) -> Result<Option<&str>> {
+        Ok(Some(
+            str::from_utf8(self.internal.segment.name())
+                .ok()
+                .read_error("Non UTF-8 Mach-O segment name")?,
+        ))
+    }
+
+    #[inline]
+    fn flags(&self) -> SegmentFlags {
+        let flags = self.internal.segment.flags(self.file.endian);
+        let maxprot = self.internal.segment.maxprot(self.file.endian);
+        let initprot = self.internal.segment.initprot(self.file.endian);
+        SegmentFlags::MachO {
+            flags,
+            maxprot,
+            initprot,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+pub(super) struct MachOSegmentInternal<'data, Mach: MachHeader, R: ReadRef<'data>> {
+    pub data: R,
+    pub segment: &'data Mach::Segment,
+}
+
+/// A trait for generic access to `SegmentCommand32` and `SegmentCommand64`.
+#[allow(missing_docs)]
+pub trait Segment: Debug + Pod {
+    type Word: Into<u64>;
+    type Endian: endian::Endian;
+    type Section: Section<Endian = Self::Endian>;
+
+    fn from_command(command: LoadCommandData<'_, Self::Endian>) -> Result<Option<(&Self, &[u8])>>;
+
+    fn cmd(&self, endian: Self::Endian) -> u32;
+    fn cmdsize(&self, endian: Self::Endian) -> u32;
+    fn segname(&self) -> &[u8; 16];
+    fn vmaddr(&self, endian: Self::Endian) -> Self::Word;
+    fn vmsize(&self, endian: Self::Endian) -> Self::Word;
+    fn fileoff(&self, endian: Self::Endian) -> Self::Word;
+    fn filesize(&self, endian: Self::Endian) -> Self::Word;
+    fn maxprot(&self, endian: Self::Endian) -> u32;
+    fn initprot(&self, endian: Self::Endian) -> u32;
+    fn nsects(&self, endian: Self::Endian) -> u32;
+    fn flags(&self, endian: Self::Endian) -> u32;
+
+    /// Return the `segname` bytes up until the null terminator.
+    fn name(&self) -> &[u8] {
+        let segname = &self.segname()[..];
+        match memchr::memchr(b'\0', segname) {
+            Some(end) => &segname[..end],
+            None => segname,
+        }
+    }
+
+    /// Return the offset and size of the segment in the file.
+    fn file_range(&self, endian: Self::Endian) -> (u64, u64) {
+        (self.fileoff(endian).into(), self.filesize(endian).into())
+    }
+
+    /// Get the segment data from the file data.
+    ///
+    /// Returns `Err` for invalid values.
+    fn data<'data, R: ReadRef<'data>>(
+        &self,
+        endian: Self::Endian,
+        data: R,
+    ) -> result::Result<&'data [u8], ()> {
+        let (offset, size) = self.file_range(endian);
+        data.read_bytes_at(offset, size)
+    }
+
+    /// Get the array of sections from the data following the segment command.
+    ///
+    /// Returns `Err` for invalid values.
+    fn sections<'data, R: ReadRef<'data>>(
+        &self,
+        endian: Self::Endian,
+        section_data: R,
+    ) -> Result<&'data [Self::Section]> {
+        section_data
+            .read_slice_at(0, self.nsects(endian) as usize)
+            .read_error("Invalid Mach-O number of sections")
+    }
+}
+
+impl<Endian: endian::Endian> Segment for macho::SegmentCommand32<Endian> {
+    type Word = u32;
+    type Endian = Endian;
+    type Section = macho::Section32<Self::Endian>;
+
+    fn from_command(command: LoadCommandData<'_, Self::Endian>) -> Result<Option<(&Self, &[u8])>> {
+        command.segment_32()
+    }
+
+    fn cmd(&self, endian: Self::Endian) -> u32 {
+        self.cmd.get(endian)
+    }
+    fn cmdsize(&self, endian: Self::Endian) -> u32 {
+        self.cmdsize.get(endian)
+    }
+    fn segname(&self) -> &[u8; 16] {
+        &self.segname
+    }
+    fn vmaddr(&self, endian: Self::Endian) -> Self::Word {
+        self.vmaddr.get(endian)
+    }
+    fn vmsize(&self, endian: Self::Endian) -> Self::Word {
+        self.vmsize.get(endian)
+    }
+    fn fileoff(&self, endian: Self::Endian) -> Self::Word {
+        self.fileoff.get(endian)
+    }
+    fn filesize(&self, endian: Self::Endian) -> Self::Word {
+        self.filesize.get(endian)
+    }
+    fn maxprot(&self, endian: Self::Endian) -> u32 {
+        self.maxprot.get(endian)
+    }
+    fn initprot(&self, endian: Self::Endian) -> u32 {
+        self.initprot.get(endian)
+    }
+    fn nsects(&self, endian: Self::Endian) -> u32 {
+        self.nsects.get(endian)
+    }
+    fn flags(&self, endian: Self::Endian) -> u32 {
+        self.flags.get(endian)
+    }
+}
+
+impl<Endian: endian::Endian> Segment for macho::SegmentCommand64<Endian> {
+    type Word = u64;
+    type Endian = Endian;
+    type Section = macho::Section64<Self::Endian>;
+
+    fn from_command(command: LoadCommandData<'_, Self::Endian>) -> Result<Option<(&Self, &[u8])>> {
+        command.segment_64()
+    }
+
+    fn cmd(&self, endian: Self::Endian) -> u32 {
+        self.cmd.get(endian)
+    }
+    fn cmdsize(&self, endian: Self::Endian) -> u32 {
+        self.cmdsize.get(endian)
+    }
+    fn segname(&self) -> &[u8; 16] {
+        &self.segname
+    }
+    fn vmaddr(&self, endian: Self::Endian) -> Self::Word {
+        self.vmaddr.get(endian)
+    }
+    fn vmsize(&self, endian: Self::Endian) -> Self::Word {
+        self.vmsize.get(endian)
+    }
+    fn fileoff(&self, endian: Self::Endian) -> Self::Word {
+        self.fileoff.get(endian)
+    }
+    fn filesize(&self, endian: Self::Endian) -> Self::Word {
+        self.filesize.get(endian)
+    }
+    fn maxprot(&self, endian: Self::Endian) -> u32 {
+        self.maxprot.get(endian)
+    }
+    fn initprot(&self, endian: Self::Endian) -> u32 {
+        self.initprot.get(endian)
+    }
+    fn nsects(&self, endian: Self::Endian) -> u32 {
+        self.nsects.get(endian)
+    }
+    fn flags(&self, endian: Self::Endian) -> u32 {
+        self.flags.get(endian)
+    }
+}
diff --git a/third_party/rust/object/src/read/macho/symbol.rs b/third_party/rust/object/src/read/macho/symbol.rs
new file mode 100644
index 0000000000..ef88521451
--- /dev/null
+++ b/third_party/rust/object/src/read/macho/symbol.rs
@@ -0,0 +1,488 @@
+use alloc::vec::Vec;
+use core::fmt::Debug;
+use core::{fmt, slice, str};
+
+use crate::endian::{self, Endianness};
+use crate::macho;
+use crate::pod::Pod;
+use crate::read::util::StringTable;
+use crate::read::{
+    self, ObjectMap, ObjectMapEntry, ObjectSymbol, ObjectSymbolTable, ReadError, ReadRef, Result,
+    SectionIndex, SectionKind, SymbolFlags, SymbolIndex, SymbolKind, SymbolMap, SymbolMapEntry,
+    SymbolScope, SymbolSection,
+};
+
+use super::{MachHeader, MachOFile};
+
+/// A table of symbol entries in a Mach-O file.
+///
+/// Also includes the string table used for the symbol names.
+#[derive(Debug, Clone, Copy)]
+pub struct SymbolTable<'data, Mach: MachHeader, R = &'data [u8]>
+where
+    R: ReadRef<'data>,
+{
+    symbols: &'data [Mach::Nlist],
+    strings: StringTable<'data, R>,
+}
+
+impl<'data, Mach: MachHeader, R: ReadRef<'data>> Default for SymbolTable<'data, Mach, R> {
+    fn default() -> Self {
+        SymbolTable {
+            symbols: &[],
+            strings: Default::default(),
+        }
+    }
+}
+
+impl<'data, Mach: MachHeader, R: ReadRef<'data>> SymbolTable<'data, Mach, R> {
+    #[inline]
+    pub(super) fn new(symbols: &'data [Mach::Nlist], strings: StringTable<'data, R>) -> Self {
+        SymbolTable { symbols, strings }
+    }
+
+    /// Return the string table used for the symbol names.
+    #[inline]
+    pub fn strings(&self) -> StringTable<'data, R> {
+        self.strings
+    }
+
+    /// Iterate over the symbols.
+    #[inline]
+    pub fn iter(&self) -> slice::Iter<'data, Mach::Nlist> {
+        self.symbols.iter()
+    }
+
+    /// Return true if the symbol table is empty.
+    #[inline]
+    pub fn is_empty(&self) -> bool {
+        self.symbols.is_empty()
+    }
+
+    /// The number of symbols.
+    #[inline]
+    pub fn len(&self) -> usize {
+        self.symbols.len()
+    }
+
+    /// Return the symbol at the given index.
+    pub fn symbol(&self, index: usize) -> Result<&'data Mach::Nlist> {
+        self.symbols
+            .get(index)
+            .read_error("Invalid Mach-O symbol index")
+    }
+
+    /// Construct a map from addresses to a user-defined map entry.
+    pub fn map<Entry: SymbolMapEntry, F: Fn(&'data Mach::Nlist) -> Option<Entry>>(
+        &self,
+        f: F,
+    ) -> SymbolMap<Entry> {
+        let mut symbols = Vec::new();
+        for nlist in self.symbols {
+            if !nlist.is_definition() {
+                continue;
+            }
+            if let Some(entry) = f(nlist) {
+                symbols.push(entry);
+            }
+        }
+        SymbolMap::new(symbols)
+    }
+
+    /// Construct a map from addresses to symbol names and object file names.
+    pub fn object_map(&self, endian: Mach::Endian) -> ObjectMap<'data> {
+        let mut symbols = Vec::new();
+        let mut objects = Vec::new();
+        let mut object = None;
+        let mut current_function = None;
+        // Each module starts with one or two N_SO symbols (path, or directory + filename)
+        // and one N_OSO symbol. The module is terminated by an empty N_SO symbol.
+        for nlist in self.symbols {
+            let n_type = nlist.n_type();
+            if n_type & macho::N_STAB == 0 {
+                continue;
+            }
+            // TODO: includes variables too (N_GSYM, N_STSYM). These may need to get their
+            // address from regular symbols though.
+            match n_type {
+                macho::N_SO => {
+                    object = None;
+                }
+                macho::N_OSO => {
+                    object = None;
+                    if let Ok(name) = nlist.name(endian, self.strings) {
+                        if !name.is_empty() {
+                            object = Some(objects.len());
+                            objects.push(name);
+                        }
+                    }
+                }
+                macho::N_FUN => {
+                    if let Ok(name) = nlist.name(endian, self.strings) {
+                        if !name.is_empty() {
+                            current_function = Some((name, nlist.n_value(endian).into()))
+                        } else if let Some((name, address)) = current_function.take() {
+                            if let Some(object) = object {
+                                symbols.push(ObjectMapEntry {
+                                    address,
+                                    size: nlist.n_value(endian).into(),
+                                    name,
+                                    object,
+                                });
+                            }
+                        }
+                    }
+                }
+                _ => {}
+            }
+        }
+        ObjectMap {
+            symbols: SymbolMap::new(symbols),
+            objects,
+        }
+    }
+}
+
+/// An iterator over the symbols of a `MachOFile32`.
+pub type MachOSymbolTable32<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOSymbolTable<'data, 'file, macho::MachHeader32<Endian>, R>;
+/// An iterator over the symbols of a `MachOFile64`.
+pub type MachOSymbolTable64<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOSymbolTable<'data, 'file, macho::MachHeader64<Endian>, R>;
+
+/// A symbol table of a `MachOFile`.
+#[derive(Debug, Clone, Copy)]
+pub struct MachOSymbolTable<'data, 'file, Mach, R = &'data [u8]>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    pub(super) file: &'file MachOFile<'data, Mach, R>,
+}
+
+impl<'data, 'file, Mach, R> read::private::Sealed for MachOSymbolTable<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+}
+
+impl<'data, 'file, Mach, R> ObjectSymbolTable<'data> for MachOSymbolTable<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    type Symbol = MachOSymbol<'data, 'file, Mach, R>;
+    type SymbolIterator = MachOSymbolIterator<'data, 'file, Mach, R>;
+
+    fn symbols(&self) -> Self::SymbolIterator {
+        MachOSymbolIterator {
+            file: self.file,
+            index: 0,
+        }
+    }
+
+    fn symbol_by_index(&self, index: SymbolIndex) -> Result<Self::Symbol> {
+        let nlist = self.file.symbols.symbol(index.0)?;
+        MachOSymbol::new(self.file, index, nlist).read_error("Unsupported Mach-O symbol index")
+    }
+}
+
+/// An iterator over the symbols of a `MachOFile32`.
+pub type MachOSymbolIterator32<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOSymbolIterator<'data, 'file, macho::MachHeader32<Endian>, R>;
+/// An iterator over the symbols of a `MachOFile64`.
+pub type MachOSymbolIterator64<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOSymbolIterator<'data, 'file, macho::MachHeader64<Endian>, R>;
+
+/// An iterator over the symbols of a `MachOFile`.
+pub struct MachOSymbolIterator<'data, 'file, Mach, R = &'data [u8]>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    pub(super) file: &'file MachOFile<'data, Mach, R>,
+    pub(super) index: usize,
+}
+
+impl<'data, 'file, Mach, R> fmt::Debug for MachOSymbolIterator<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("MachOSymbolIterator").finish()
+    }
+}
+
+impl<'data, 'file, Mach, R> Iterator for MachOSymbolIterator<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    type Item = MachOSymbol<'data, 'file, Mach, R>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        loop {
+            let index = self.index;
+            let nlist = self.file.symbols.symbols.get(index)?;
+            self.index += 1;
+            if let Some(symbol) = MachOSymbol::new(self.file, SymbolIndex(index), nlist) {
+                return Some(symbol);
+            }
+        }
+    }
+}
+
+/// A symbol of a `MachOFile32`.
+pub type MachOSymbol32<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOSymbol<'data, 'file, macho::MachHeader32<Endian>, R>;
+/// A symbol of a `MachOFile64`.
+pub type MachOSymbol64<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    MachOSymbol<'data, 'file, macho::MachHeader64<Endian>, R>;
+
+/// A symbol of a `MachOFile`.
+#[derive(Debug, Clone, Copy)]
+pub struct MachOSymbol<'data, 'file, Mach, R = &'data [u8]>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    file: &'file MachOFile<'data, Mach, R>,
+    index: SymbolIndex,
+    nlist: &'data Mach::Nlist,
+}
+
+impl<'data, 'file, Mach, R> MachOSymbol<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    pub(super) fn new(
+        file: &'file MachOFile<'data, Mach, R>,
+        index: SymbolIndex,
+        nlist: &'data Mach::Nlist,
+    ) -> Option<Self> {
+        if nlist.n_type() & macho::N_STAB != 0 {
+            return None;
+        }
+        Some(MachOSymbol { file, index, nlist })
+    }
+}
+
+impl<'data, 'file, Mach, R> read::private::Sealed for MachOSymbol<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+}
+
+impl<'data, 'file, Mach, R> ObjectSymbol<'data> for MachOSymbol<'data, 'file, Mach, R>
+where
+    Mach: MachHeader,
+    R: ReadRef<'data>,
+{
+    #[inline]
+    fn index(&self) -> SymbolIndex {
+        self.index
+    }
+
+    fn name_bytes(&self) -> Result<&'data [u8]> {
+        self.nlist.name(self.file.endian, self.file.symbols.strings)
+    }
+
+    fn name(&self) -> Result<&'data str> {
+        let name = self.name_bytes()?;
+        str::from_utf8(name)
+            .ok()
+            .read_error("Non UTF-8 Mach-O symbol name")
+    }
+
+    #[inline]
+    fn address(&self) -> u64 {
+        self.nlist.n_value(self.file.endian).into()
+    }
+
+    #[inline]
+    fn size(&self) -> u64 {
+        0
+    }
+
+    fn kind(&self) -> SymbolKind {
+        self.section()
+            .index()
+            .and_then(|index| self.file.section_internal(index).ok())
+            .map(|section| match section.kind {
+                SectionKind::Text => SymbolKind::Text,
+                SectionKind::Data
+                | SectionKind::ReadOnlyData
+                | SectionKind::ReadOnlyString
+                | SectionKind::UninitializedData
+                | SectionKind::Common => SymbolKind::Data,
+                SectionKind::Tls | SectionKind::UninitializedTls | SectionKind::TlsVariables => {
+                    SymbolKind::Tls
+                }
+                _ => SymbolKind::Unknown,
+            })
+            .unwrap_or(SymbolKind::Unknown)
+    }
+
+    fn section(&self) -> SymbolSection {
+        match self.nlist.n_type() & macho::N_TYPE {
+            macho::N_UNDF => SymbolSection::Undefined,
+            macho::N_ABS => SymbolSection::Absolute,
+            macho::N_SECT => {
+                let n_sect = self.nlist.n_sect();
+                if n_sect != 0 {
+                    SymbolSection::Section(SectionIndex(n_sect as usize))
+                } else {
+                    SymbolSection::Unknown
+                }
+            }
+            _ => SymbolSection::Unknown,
+        }
+    }
+
+    #[inline]
+    fn is_undefined(&self) -> bool {
+        self.nlist.n_type() & macho::N_TYPE == macho::N_UNDF
+    }
+
+    #[inline]
+    fn is_definition(&self) -> bool {
+        self.nlist.is_definition()
+    }
+
+    #[inline]
+    fn is_common(&self) -> bool {
+        // Mach-O common symbols are based on section, not symbol
+        false
+    }
+
+    #[inline]
+    fn is_weak(&self) -> bool {
+        self.nlist.n_desc(self.file.endian) & (macho::N_WEAK_REF | macho::N_WEAK_DEF) != 0
+    }
+
+    fn scope(&self) -> SymbolScope {
+        let n_type = self.nlist.n_type();
+        if n_type & macho::N_TYPE == macho::N_UNDF {
+            SymbolScope::Unknown
+        } else if n_type & macho::N_EXT == 0 {
+            SymbolScope::Compilation
+        } else if n_type & macho::N_PEXT != 0 {
+            SymbolScope::Linkage
+        } else {
+            SymbolScope::Dynamic
+        }
+    }
+
+    #[inline]
+    fn is_global(&self) -> bool {
+        self.scope() != SymbolScope::Compilation
+    }
+
+    #[inline]
+    fn is_local(&self) -> bool {
+        self.scope() == SymbolScope::Compilation
+    }
+
+    #[inline]
+    fn flags(&self) -> SymbolFlags<SectionIndex, SymbolIndex> {
+        let n_desc = self.nlist.n_desc(self.file.endian);
+        SymbolFlags::MachO { n_desc }
+    }
+}
+
+/// A trait for generic access to `Nlist32` and `Nlist64`.
+#[allow(missing_docs)]
+pub trait Nlist: Debug + Pod {
+    type Word: Into<u64>;
+    type Endian: endian::Endian;
+
+    fn n_strx(&self, endian: Self::Endian) -> u32;
+    fn n_type(&self) -> u8;
+    fn n_sect(&self) -> u8;
+    fn n_desc(&self, endian: Self::Endian) -> u16;
+    fn n_value(&self, endian: Self::Endian) -> Self::Word;
+
+    fn name<'data, R: ReadRef<'data>>(
+        &self,
+        endian: Self::Endian,
+        strings: StringTable<'data, R>,
+    ) -> Result<&'data [u8]> {
+        strings
+            .get(self.n_strx(endian))
+            .read_error("Invalid Mach-O symbol name offset")
+    }
+
+    /// Return true if this is a STAB symbol.
+    ///
+    /// This determines the meaning of the `n_type` field.
+    fn is_stab(&self) -> bool {
+        self.n_type() & macho::N_STAB != 0
+    }
+
+    /// Return true if this is an undefined symbol.
+    fn is_undefined(&self) -> bool {
+        let n_type = self.n_type();
+        n_type & macho::N_STAB == 0 && n_type & macho::N_TYPE == macho::N_UNDF
+    }
+
+    /// Return true if the symbol is a definition of a function or data object.
+    fn is_definition(&self) -> bool {
+        let n_type = self.n_type();
+        n_type & macho::N_STAB == 0 && n_type & macho::N_TYPE != macho::N_UNDF
+    }
+
+    /// Return the library ordinal.
+    ///
+    /// This is either a 1-based index into the dylib load commands,
+    /// or a special ordinal.
+    #[inline]
+    fn library_ordinal(&self, endian: Self::Endian) -> u8 {
+        (self.n_desc(endian) >> 8) as u8
+    }
+}
+
+impl<Endian: endian::Endian> Nlist for macho::Nlist32<Endian> {
+    type Word = u32;
+    type Endian = Endian;
+
+    fn n_strx(&self, endian: Self::Endian) -> u32 {
+        self.n_strx.get(endian)
+    }
+    fn n_type(&self) -> u8 {
+        self.n_type
+    }
+    fn n_sect(&self) -> u8 {
+        self.n_sect
+    }
+    fn n_desc(&self, endian: Self::Endian) -> u16 {
+        self.n_desc.get(endian)
+    }
+    fn n_value(&self, endian: Self::Endian) -> Self::Word {
+        self.n_value.get(endian)
+    }
+}
+
+impl<Endian: endian::Endian> Nlist for macho::Nlist64<Endian> {
+    type Word = u64;
+    type Endian = Endian;
+
+    fn n_strx(&self, endian: Self::Endian) -> u32 {
+        self.n_strx.get(endian)
+    }
+    fn n_type(&self) -> u8 {
+        self.n_type
+    }
+    fn n_sect(&self) -> u8 {
+        self.n_sect
+    }
+    fn n_desc(&self, endian: Self::Endian) -> u16 {
+        self.n_desc.get(endian)
+    }
+    fn n_value(&self, endian: Self::Endian) -> Self::Word {
+        self.n_value.get(endian)
+    }
+}