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use super::{Context, Mapping, Mmap, 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(Bytes(&map))?;
let endian = macho.endian().ok()?;
let uuid = macho.uuid(endian, data).ok()??;
let parent = path.parent()?;
for entry in parent.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) = load_dsym(&candidates, uuid) {
return Some(mapping);
}
}
let stash = Stash::new();
let inner = super::cx(&stash, Object::parse(macho, endian, data)?)?;
return Some(mk!(Mapping { map, inner, stash }));
fn load_dsym(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 (macho, data) = find_header(Bytes(&map))?;
let endian = macho.endian().ok()?;
let entry_uuid = macho.uuid(endian, data).ok()??;
if entry_uuid != uuid {
continue;
}
let stash = Stash::new();
if let Some(cx) =
Object::parse(macho, endian, data).and_then(|o| super::cx(&stash, o))
{
return Some(mk!(Mapping { map, cx, stash }));
}
}
None
}
}
}
fn find_header(mut data: Bytes<'_>) -> Option<(&'_ Mach, Bytes<'_>)> {
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
}
};
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).ok().map(|h| (h, data))
}
pub struct Object<'a> {
endian: NativeEndian,
data: Bytes<'a>,
dwarf: Option<&'a [MachSection]>,
syms: Vec<(&'a [u8], u64)>,
}
impl<'a> Object<'a> {
fn parse(mach: &'a Mach, endian: NativeEndian, data: Bytes<'a>) -> Option<Object<'a>> {
let mut dwarf = None;
let mut syms = Vec::new();
let mut commands = mach.load_commands(endian, data).ok()?;
while let Ok(Some(command)) = commands.next() {
if let Some((segment, section_data)) = MachSegment::from_command(command).ok()? {
if segment.name() == b"__DWARF" {
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_undefined() {
Some((name, u64::from(nlist.n_value(endian))))
} else {
None
}
})
.collect();
syms.sort_unstable_by_key(|(_, addr)| *addr);
}
}
Some(Object {
endian,
data,
dwarf,
syms,
})
}
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()?.0)
}
pub fn search_symtab<'b>(&'b self, addr: u64) -> Option<&'b [u8]> {
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)
}
}