1 files changed, 324 insertions, 0 deletions
diff --git a/vendor/backtrace/src/symbolize/gimli/macho.rs b/vendor/backtrace/src/symbolize/gimli/macho.rs
new file mode 100644
index 000000000..ec5673843
--- /dev/null
+++ b/vendor/backtrace/src/symbolize/gimli/macho.rs
@@ -0,0 +1,324 @@
+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 {
+    // The loading path for OSX is is so different we just have a completely
+    // different implementation of the function here. On OSX we need to go
+    // probing the filesystem for a bunch of files.
+    pub fn new(path: &Path) -> Option<Mapping> {
+        // First up we need to load the unique UUID which is stored in the macho
+        // header of the file we're reading, specified at `path`.
+        let map = super::mmap(path)?;
+        let (macho, data) = find_header(&map)?;
+        let endian = macho.endian().ok()?;
+        let uuid = macho.uuid(endian, data, 0).ok()?;
+
+        // Next we need to look for a `*.dSYM` file. For now we just probe the
+        // containing directory and look around for something that matches
+        // `*.dSYM`. Once it's found we root through the dwarf resources that it
+        // contains and try to find a macho file which has a matching UUID as
+        // the one of our own file. If we find a match that's the dwarf file we
+        // want to return.
+        if let Some(uuid) = uuid {
+            if let Some(parent) = path.parent() {
+                if let Some(mapping) = Mapping::load_dsym(parent, uuid) {
+                    return Some(mapping);
+                }
+            }
+        }
+
+        // Looks like nothing matched our UUID, so let's at least return our own
+        // file. This should have the symbol table for at least some
+        // symbolication purposes.
+        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> {
+        // Look for files in the `DWARF` directory which have a matching uuid to
+        // the original object file. If we find one then we found the debug
+        // information.
+        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))
+}
+
+// This is used both for executables/libraries and source object files.
+pub struct Object<'a> {
+    endian: NativeEndian,
+    data: &'a [u8],
+    dwarf: Option<&'a [MachSection]>,
+    syms: Vec<(&'a [u8], u64)>,
+    syms_sort_by_name: bool,
+    // Only set for executables/libraries, and not the source object files.
+    object_map: Option<object::ObjectMap<'a>>,
+    // The outer Option is for lazy loading, and the inner Option allows load errors to be cached.
+    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()? {
+                // Object files should have all sections in a single unnamed segment load command.
+                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 {
+                    // We never search object file symbols by address.
+                    // Instead, we already know the symbol name from the executable, and we
+                    // need to search by name to find the matching symbol in the object file.
+                    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".")
+                    && &section_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)
+    }
+
+    /// Try to load a context for an object file.
+    ///
+    /// If dsymutil was not run, then the DWARF may be found in the source object files.
+    pub(super) fn search_object_map<'b>(&'b mut self, addr: u64) -> Option<(&Context<'b>, u64)> {
+        // `object_map` contains a map from addresses to symbols and object paths.
+        // Look up the address and get a mapping for the object.
+        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() {
+            // No cached mapping, so create it.
+            *mapping = Some(object_mapping(object_map.objects().get(object_index)?));
+        }
+        let cx: &'b Context<'static> = &mapping.as_ref()?.as_ref()?.cx;
+        // Don't leak the `'static` lifetime, make sure it's scoped to just ourselves.
+        let cx = unsafe { core::mem::transmute::<&'b Context<'static>, &'b Context<'b>>(cx) };
+
+        // We must translate the address in order to be able to look it up
+        // in the DWARF in the object file.
+        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;
+
+    // `N_OSO` symbol names can be either `/path/to/object.o` or `/path/to/archive.a(object.o)`.
+    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..]))
+}