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use super::{Box, Context, Mapping, Path, Stash, Vec};
use core::convert::TryInto;
use object::macho;
use object::read::macho::{MachHeader, Nlist, Section, Segment as _};
use object::{Bytes, NativeEndian};
#[cfg(target_pointer_width = "32")]
type Mach = object::macho::MachHeader32<NativeEndian>;
#[cfg(target_pointer_width = "64")]
type Mach = object::macho::MachHeader64<NativeEndian>;
type MachSegment = <Mach as MachHeader>::Segment;
type MachSection = <Mach as MachHeader>::Section;
type MachNlist = <Mach as MachHeader>::Nlist;
impl Mapping {
pub fn new(path: &Path) -> Option<Mapping> {
let map = super::mmap(path)?;
let (macho, data) = find_header(&map)?;
let endian = macho.endian().ok()?;
let uuid = macho.uuid(endian, data, 0).ok()?;
if let Some(uuid) = uuid {
if let Some(parent) = path.parent() {
if let Some(mapping) = Mapping::load_dsym(parent, uuid) {
return Some(mapping);
}
}
}
Mapping::mk(map, |data, stash| {
let (macho, data) = find_header(data)?;
let endian = macho.endian().ok()?;
let obj = Object::parse(macho, endian, data)?;
Context::new(stash, obj, None)
})
}
fn load_dsym(dir: &Path, uuid: [u8; 16]) -> Option<Mapping> {
for entry in dir.read_dir().ok()? {
let entry = entry.ok()?;
let filename = match entry.file_name().into_string() {
Ok(name) => name,
Err(_) => continue,
};
if !filename.ends_with(".dSYM") {
continue;
}
let candidates = entry.path().join("Contents/Resources/DWARF");
if let Some(mapping) = Mapping::try_dsym_candidate(&candidates, uuid) {
return Some(mapping);
}
}
None
}
fn try_dsym_candidate(dir: &Path, uuid: [u8; 16]) -> Option<Mapping> {
for entry in dir.read_dir().ok()? {
let entry = entry.ok()?;
let map = super::mmap(&entry.path())?;
let candidate = Mapping::mk(map, |data, stash| {
let (macho, data) = find_header(data)?;
let endian = macho.endian().ok()?;
let entry_uuid = macho.uuid(endian, data, 0).ok()??;
if entry_uuid != uuid {
return None;
}
let obj = Object::parse(macho, endian, data)?;
Context::new(stash, obj, None)
});
if let Some(candidate) = candidate {
return Some(candidate);
}
}
None
}
}
fn find_header(data: &'_ [u8]) -> Option<(&'_ Mach, &'_ [u8])> {
use object::endian::BigEndian;
let desired_cpu = || {
if cfg!(target_arch = "x86") {
Some(macho::CPU_TYPE_X86)
} else if cfg!(target_arch = "x86_64") {
Some(macho::CPU_TYPE_X86_64)
} else if cfg!(target_arch = "arm") {
Some(macho::CPU_TYPE_ARM)
} else if cfg!(target_arch = "aarch64") {
Some(macho::CPU_TYPE_ARM64)
} else {
None
}
};
let mut data = Bytes(data);
match data
.clone()
.read::<object::endian::U32<NativeEndian>>()
.ok()?
.get(NativeEndian)
{
macho::MH_MAGIC_64 | macho::MH_CIGAM_64 | macho::MH_MAGIC | macho::MH_CIGAM => {}
macho::FAT_MAGIC | macho::FAT_CIGAM => {
let mut header_data = data;
let endian = BigEndian;
let header = header_data.read::<macho::FatHeader>().ok()?;
let nfat = header.nfat_arch.get(endian);
let arch = (0..nfat)
.filter_map(|_| header_data.read::<macho::FatArch32>().ok())
.find(|arch| desired_cpu() == Some(arch.cputype.get(endian)))?;
let offset = arch.offset.get(endian);
let size = arch.size.get(endian);
data = data
.read_bytes_at(offset.try_into().ok()?, size.try_into().ok()?)
.ok()?;
}
macho::FAT_MAGIC_64 | macho::FAT_CIGAM_64 => {
let mut header_data = data;
let endian = BigEndian;
let header = header_data.read::<macho::FatHeader>().ok()?;
let nfat = header.nfat_arch.get(endian);
let arch = (0..nfat)
.filter_map(|_| header_data.read::<macho::FatArch64>().ok())
.find(|arch| desired_cpu() == Some(arch.cputype.get(endian)))?;
let offset = arch.offset.get(endian);
let size = arch.size.get(endian);
data = data
.read_bytes_at(offset.try_into().ok()?, size.try_into().ok()?)
.ok()?;
}
_ => return None,
}
Mach::parse(data.0, 0).ok().map(|h| (h, data.0))
}
pub struct Object<'a> {
endian: NativeEndian,
data: &'a [u8],
dwarf: Option<&'a [MachSection]>,
syms: Vec<(&'a [u8], u64)>,
syms_sort_by_name: bool,
object_map: Option<object::ObjectMap<'a>>,
object_mappings: Box<[Option<Option<Mapping>>]>,
}
impl<'a> Object<'a> {
fn parse(mach: &'a Mach, endian: NativeEndian, data: &'a [u8]) -> Option<Object<'a>> {
let is_object = mach.filetype(endian) == object::macho::MH_OBJECT;
let mut dwarf = None;
let mut syms = Vec::new();
let mut syms_sort_by_name = false;
let mut commands = mach.load_commands(endian, data, 0).ok()?;
let mut object_map = None;
let mut object_mappings = Vec::new();
while let Ok(Some(command)) = commands.next() {
if let Some((segment, section_data)) = MachSegment::from_command(command).ok()? {
if segment.name() == b"__DWARF" || (is_object && segment.name() == b"") {
dwarf = segment.sections(endian, section_data).ok();
}
} else if let Some(symtab) = command.symtab().ok()? {
let symbols = symtab.symbols::<Mach, _>(endian, data).ok()?;
syms = symbols
.iter()
.filter_map(|nlist: &MachNlist| {
let name = nlist.name(endian, symbols.strings()).ok()?;
if name.len() > 0 && nlist.is_definition() {
Some((name, u64::from(nlist.n_value(endian))))
} else {
None
}
})
.collect();
if is_object {
syms.sort_unstable_by_key(|(name, _)| *name);
syms_sort_by_name = true;
} else {
syms.sort_unstable_by_key(|(_, addr)| *addr);
let map = symbols.object_map(endian);
object_mappings.resize_with(map.objects().len(), || None);
object_map = Some(map);
}
}
}
Some(Object {
endian,
data,
dwarf,
syms,
syms_sort_by_name,
object_map,
object_mappings: object_mappings.into_boxed_slice(),
})
}
pub fn section(&self, _: &Stash, name: &str) -> Option<&'a [u8]> {
let name = name.as_bytes();
let dwarf = self.dwarf?;
let section = dwarf.into_iter().find(|section| {
let section_name = section.name();
section_name == name || {
section_name.starts_with(b"__")
&& name.starts_with(b".")
&& §ion_name[2..] == &name[1..]
}
})?;
Some(section.data(self.endian, self.data).ok()?)
}
pub fn search_symtab<'b>(&'b self, addr: u64) -> Option<&'b [u8]> {
debug_assert!(!self.syms_sort_by_name);
let i = match self.syms.binary_search_by_key(&addr, |(_, addr)| *addr) {
Ok(i) => i,
Err(i) => i.checked_sub(1)?,
};
let (sym, _addr) = self.syms.get(i)?;
Some(sym)
}
pub(super) fn search_object_map<'b>(&'b mut self, addr: u64) -> Option<(&Context<'b>, u64)> {
let object_map = self.object_map.as_ref()?;
let symbol = object_map.get(addr)?;
let object_index = symbol.object_index();
let mapping = self.object_mappings.get_mut(object_index)?;
if mapping.is_none() {
*mapping = Some(object_mapping(object_map.objects().get(object_index)?));
}
let cx: &'b Context<'static> = &mapping.as_ref()?.as_ref()?.cx;
let cx = unsafe { core::mem::transmute::<&'b Context<'static>, &'b Context<'b>>(cx) };
debug_assert!(cx.object.syms.is_empty() || cx.object.syms_sort_by_name);
let i = cx
.object
.syms
.binary_search_by_key(&symbol.name(), |(name, _)| *name)
.ok()?;
let object_symbol = cx.object.syms.get(i)?;
let object_addr = addr
.wrapping_sub(symbol.address())
.wrapping_add(object_symbol.1);
Some((cx, object_addr))
}
}
fn object_mapping(path: &[u8]) -> Option<Mapping> {
use super::mystd::ffi::OsStr;
use super::mystd::os::unix::prelude::*;
let map;
let member_name = if let Some((archive_path, member_name)) = split_archive_path(path) {
map = super::mmap(Path::new(OsStr::from_bytes(archive_path)))?;
Some(member_name)
} else {
map = super::mmap(Path::new(OsStr::from_bytes(path)))?;
None
};
Mapping::mk(map, |data, stash| {
let data = match member_name {
Some(member_name) => {
let archive = object::read::archive::ArchiveFile::parse(data).ok()?;
let member = archive
.members()
.filter_map(Result::ok)
.find(|m| m.name() == member_name)?;
member.data(data).ok()?
}
None => data,
};
let (macho, data) = find_header(data)?;
let endian = macho.endian().ok()?;
let obj = Object::parse(macho, endian, data)?;
Context::new(stash, obj, None)
})
}
fn split_archive_path(path: &[u8]) -> Option<(&[u8], &[u8])> {
let (last, path) = path.split_last()?;
if *last != b')' {
return None;
}
let index = path.iter().position(|&x| x == b'(')?;
let (archive, rest) = path.split_at(index);
Some((archive, &rest[1..]))
}