Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

1 files changed, 511 insertions, 0 deletions

diff --git a/vendor/backtrace/src/symbolize/gimli.rs b/vendor/backtrace/src/symbolize/gimli.rs
new file mode 100644
index 0000000..7f1c6a5
--- /dev/null
+++ b/vendor/backtrace/src/symbolize/gimli.rs
@@ -0,0 +1,511 @@
+//! Support for symbolication using the `gimli` crate on crates.io
+//!
+//! This is the default symbolication implementation for Rust.
+
+use self::gimli::read::EndianSlice;
+use self::gimli::NativeEndian as Endian;
+use self::mmap::Mmap;
+use self::stash::Stash;
+use super::BytesOrWideString;
+use super::ResolveWhat;
+use super::SymbolName;
+use addr2line::gimli;
+use core::convert::TryInto;
+use core::mem;
+use core::u32;
+use libc::c_void;
+use mystd::ffi::OsString;
+use mystd::fs::File;
+use mystd::path::Path;
+use mystd::prelude::v1::*;
+
+#[cfg(backtrace_in_libstd)]
+mod mystd {
+    pub use crate::*;
+}
+#[cfg(not(backtrace_in_libstd))]
+extern crate std as mystd;
+
+cfg_if::cfg_if! {
+    if #[cfg(windows)] {
+        #[path = "gimli/mmap_windows.rs"]
+        mod mmap;
+    } else if #[cfg(any(
+        target_os = "android",
+        target_os = "freebsd",
+        target_os = "fuchsia",
+        target_os = "haiku",
+        target_os = "ios",
+        target_os = "linux",
+        target_os = "macos",
+        target_os = "openbsd",
+        target_os = "solaris",
+        target_os = "illumos",
+    ))] {
+        #[path = "gimli/mmap_unix.rs"]
+        mod mmap;
+    } else {
+        #[path = "gimli/mmap_fake.rs"]
+        mod mmap;
+    }
+}
+
+mod stash;
+
+const MAPPINGS_CACHE_SIZE: usize = 4;
+
+struct Mapping {
+    // 'static lifetime is a lie to hack around lack of support for self-referential structs.
+    cx: Context<'static>,
+    _map: Mmap,
+    stash: Stash,
+}
+
+enum Either<A, B> {
+    #[allow(dead_code)]
+    A(A),
+    B(B),
+}
+
+impl Mapping {
+    /// Creates a `Mapping` by ensuring that the `data` specified is used to
+    /// create a `Context` and it can only borrow from that or the `Stash` of
+    /// decompressed sections or auxiliary data.
+    fn mk<F>(data: Mmap, mk: F) -> Option<Mapping>
+    where
+        F: for<'a> FnOnce(&'a [u8], &'a Stash) -> Option<Context<'a>>,
+    {
+        Mapping::mk_or_other(data, move |data, stash| {
+            let cx = mk(data, stash)?;
+            Some(Either::B(cx))
+        })
+    }
+
+    /// Creates a `Mapping` from `data`, or if the closure decides to, returns a
+    /// different mapping.
+    fn mk_or_other<F>(data: Mmap, mk: F) -> Option<Mapping>
+    where
+        F: for<'a> FnOnce(&'a [u8], &'a Stash) -> Option<Either<Mapping, Context<'a>>>,
+    {
+        let stash = Stash::new();
+        let cx = match mk(&data, &stash)? {
+            Either::A(mapping) => return Some(mapping),
+            Either::B(cx) => cx,
+        };
+        Some(Mapping {
+            // Convert to 'static lifetimes since the symbols should
+            // only borrow `map` and `stash` and we're preserving them below.
+            cx: unsafe { core::mem::transmute::<Context<'_>, Context<'static>>(cx) },
+            _map: data,
+            stash: stash,
+        })
+    }
+}
+
+struct Context<'a> {
+    dwarf: addr2line::Context<EndianSlice<'a, Endian>>,
+    object: Object<'a>,
+    package: Option<gimli::DwarfPackage<EndianSlice<'a, Endian>>>,
+}
+
+impl<'data> Context<'data> {
+    fn new(
+        stash: &'data Stash,
+        object: Object<'data>,
+        sup: Option<Object<'data>>,
+        dwp: Option<Object<'data>>,
+    ) -> Option<Context<'data>> {
+        let mut sections = gimli::Dwarf::load(|id| -> Result<_, ()> {
+            let data = object.section(stash, id.name()).unwrap_or(&[]);
+            Ok(EndianSlice::new(data, Endian))
+        })
+        .ok()?;
+
+        if let Some(sup) = sup {
+            sections
+                .load_sup(|id| -> Result<_, ()> {
+                    let data = sup.section(stash, id.name()).unwrap_or(&[]);
+                    Ok(EndianSlice::new(data, Endian))
+                })
+                .ok()?;
+        }
+        let dwarf = addr2line::Context::from_dwarf(sections).ok()?;
+
+        let mut package = None;
+        if let Some(dwp) = dwp {
+            package = Some(
+                gimli::DwarfPackage::load(
+                    |id| -> Result<_, gimli::Error> {
+                        let data = id
+                            .dwo_name()
+                            .and_then(|name| dwp.section(stash, name))
+                            .unwrap_or(&[]);
+                        Ok(EndianSlice::new(data, Endian))
+                    },
+                    EndianSlice::new(&[], Endian),
+                )
+                .ok()?,
+            );
+        }
+
+        Some(Context {
+            dwarf,
+            object,
+            package,
+        })
+    }
+
+    fn find_frames(
+        &'_ self,
+        stash: &'data Stash,
+        probe: u64,
+    ) -> gimli::Result<addr2line::FrameIter<'_, EndianSlice<'data, Endian>>> {
+        use addr2line::{LookupContinuation, LookupResult};
+
+        let mut l = self.dwarf.find_frames(probe);
+        loop {
+            let (load, continuation) = match l {
+                LookupResult::Output(output) => break output,
+                LookupResult::Load { load, continuation } => (load, continuation),
+            };
+
+            l = continuation.resume(handle_split_dwarf(self.package.as_ref(), stash, load));
+        }
+    }
+}
+
+fn mmap(path: &Path) -> Option<Mmap> {
+    let file = File::open(path).ok()?;
+    let len = file.metadata().ok()?.len().try_into().ok()?;
+    unsafe { Mmap::map(&file, len) }
+}
+
+cfg_if::cfg_if! {
+    if #[cfg(windows)] {
+        mod coff;
+        use self::coff::{handle_split_dwarf, Object};
+    } else if #[cfg(any(
+        target_os = "macos",
+        target_os = "ios",
+        target_os = "tvos",
+        target_os = "watchos",
+    ))] {
+        mod macho;
+        use self::macho::{handle_split_dwarf, Object};
+    } else {
+        mod elf;
+        use self::elf::{handle_split_dwarf, Object};
+    }
+}
+
+cfg_if::cfg_if! {
+    if #[cfg(windows)] {
+        mod libs_windows;
+        use libs_windows::native_libraries;
+    } else if #[cfg(any(
+        target_os = "macos",
+        target_os = "ios",
+        target_os = "tvos",
+        target_os = "watchos",
+    ))] {
+        mod libs_macos;
+        use libs_macos::native_libraries;
+    } else if #[cfg(target_os = "illumos")] {
+        mod libs_illumos;
+        use libs_illumos::native_libraries;
+    } else if #[cfg(all(
+        any(
+            target_os = "linux",
+            target_os = "fuchsia",
+            target_os = "freebsd",
+            target_os = "openbsd",
+            target_os = "netbsd",
+            all(target_os = "android", feature = "dl_iterate_phdr"),
+        ),
+        not(target_env = "uclibc"),
+    ))] {
+        mod libs_dl_iterate_phdr;
+        use libs_dl_iterate_phdr::native_libraries;
+        #[path = "gimli/parse_running_mmaps_unix.rs"]
+        mod parse_running_mmaps;
+    } else if #[cfg(target_env = "libnx")] {
+        mod libs_libnx;
+        use libs_libnx::native_libraries;
+    } else if #[cfg(target_os = "haiku")] {
+        mod libs_haiku;
+        use libs_haiku::native_libraries;
+    } else {
+        // Everything else should doesn't know how to load native libraries.
+        fn native_libraries() -> Vec<Library> {
+            Vec::new()
+        }
+    }
+}
+
+#[derive(Default)]
+struct Cache {
+    /// All known shared libraries that have been loaded.
+    libraries: Vec<Library>,
+
+    /// Mappings cache where we retain parsed dwarf information.
+    ///
+    /// This list has a fixed capacity for its entire lifetime which never
+    /// increases. The `usize` element of each pair is an index into `libraries`
+    /// above where `usize::max_value()` represents the current executable. The
+    /// `Mapping` is corresponding parsed dwarf information.
+    ///
+    /// Note that this is basically an LRU cache and we'll be shifting things
+    /// around in here as we symbolize addresses.
+    mappings: Vec<(usize, Mapping)>,
+}
+
+struct Library {
+    name: OsString,
+    /// Segments of this library loaded into memory, and where they're loaded.
+    segments: Vec<LibrarySegment>,
+    /// The "bias" of this library, typically where it's loaded into memory.
+    /// This value is added to each segment's stated address to get the actual
+    /// virtual memory address that the segment is loaded into. Additionally
+    /// this bias is subtracted from real virtual memory addresses to index into
+    /// debuginfo and the symbol table.
+    bias: usize,
+}
+
+struct LibrarySegment {
+    /// The stated address of this segment in the object file. This is not
+    /// actually where the segment is loaded, but rather this address plus the
+    /// containing library's `bias` is where to find it.
+    stated_virtual_memory_address: usize,
+    /// The size of this segment in memory.
+    len: usize,
+}
+
+// unsafe because this is required to be externally synchronized
+pub unsafe fn clear_symbol_cache() {
+    Cache::with_global(|cache| cache.mappings.clear());
+}
+
+impl Cache {
+    fn new() -> Cache {
+        Cache {
+            mappings: Vec::with_capacity(MAPPINGS_CACHE_SIZE),
+            libraries: native_libraries(),
+        }
+    }
+
+    // unsafe because this is required to be externally synchronized
+    unsafe fn with_global(f: impl FnOnce(&mut Self)) {
+        // A very small, very simple LRU cache for debug info mappings.
+        //
+        // The hit rate should be very high, since the typical stack doesn't cross
+        // between many shared libraries.
+        //
+        // The `addr2line::Context` structures are pretty expensive to create. Its
+        // cost is expected to be amortized by subsequent `locate` queries, which
+        // leverage the structures built when constructing `addr2line::Context`s to
+        // get nice speedups. If we didn't have this cache, that amortization would
+        // never happen, and symbolicating backtraces would be ssssllllooooowwww.
+        static mut MAPPINGS_CACHE: Option<Cache> = None;
+
+        f(MAPPINGS_CACHE.get_or_insert_with(|| Cache::new()))
+    }
+
+    fn avma_to_svma(&self, addr: *const u8) -> Option<(usize, *const u8)> {
+        self.libraries
+            .iter()
+            .enumerate()
+            .filter_map(|(i, lib)| {
+                // First up, test if this `lib` has any segment containing the
+                // `addr` (handling relocation). If this check passes then we
+                // can continue below and actually translate the address.
+                //
+                // Note that we're using `wrapping_add` here to avoid overflow
+                // checks. It's been seen in the wild that the SVMA + bias
+                // computation overflows. It seems a bit odd that would happen
+                // but there's not a huge amount we can do about it other than
+                // probably just ignore those segments since they're likely
+                // pointing off into space. This originally came up in
+                // rust-lang/backtrace-rs#329.
+                if !lib.segments.iter().any(|s| {
+                    let svma = s.stated_virtual_memory_address;
+                    let start = svma.wrapping_add(lib.bias);
+                    let end = start.wrapping_add(s.len);
+                    let address = addr as usize;
+                    start <= address && address < end
+                }) {
+                    return None;
+                }
+
+                // Now that we know `lib` contains `addr`, we can offset with
+                // the bias to find the stated virtual memory address.
+                let svma = (addr as usize).wrapping_sub(lib.bias);
+                Some((i, svma as *const u8))
+            })
+            .next()
+    }
+
+    fn mapping_for_lib<'a>(&'a mut self, lib: usize) -> Option<(&'a mut Context<'a>, &'a Stash)> {
+        let idx = self.mappings.iter().position(|(idx, _)| *idx == lib);
+
+        // Invariant: after this conditional completes without early returning
+        // from an error, the cache entry for this path is at index 0.
+
+        if let Some(idx) = idx {
+            // When the mapping is already in the cache, move it to the front.
+            if idx != 0 {
+                let entry = self.mappings.remove(idx);
+                self.mappings.insert(0, entry);
+            }
+        } else {
+            // When the mapping is not in the cache, create a new mapping,
+            // insert it into the front of the cache, and evict the oldest cache
+            // entry if necessary.
+            let name = &self.libraries[lib].name;
+            let mapping = Mapping::new(name.as_ref())?;
+
+            if self.mappings.len() == MAPPINGS_CACHE_SIZE {
+                self.mappings.pop();
+            }
+
+            self.mappings.insert(0, (lib, mapping));
+        }
+
+        let mapping = &mut self.mappings[0].1;
+        let cx: &'a mut Context<'static> = &mut mapping.cx;
+        let stash: &'a Stash = &mapping.stash;
+        // don't leak the `'static` lifetime, make sure it's scoped to just
+        // ourselves
+        Some((
+            unsafe { mem::transmute::<&'a mut Context<'static>, &'a mut Context<'a>>(cx) },
+            stash,
+        ))
+    }
+}
+
+pub unsafe fn resolve(what: ResolveWhat<'_>, cb: &mut dyn FnMut(&super::Symbol)) {
+    let addr = what.address_or_ip();
+    let mut call = |sym: Symbol<'_>| {
+        // Extend the lifetime of `sym` to `'static` since we are unfortunately
+        // required to here, but it's only ever going out as a reference so no
+        // reference to it should be persisted beyond this frame anyway.
+        let sym = mem::transmute::<Symbol<'_>, Symbol<'static>>(sym);
+        (cb)(&super::Symbol { inner: sym });
+    };
+
+    Cache::with_global(|cache| {
+        let (lib, addr) = match cache.avma_to_svma(addr as *const u8) {
+            Some(pair) => pair,
+            None => return,
+        };
+
+        // Finally, get a cached mapping or create a new mapping for this file, and
+        // evaluate the DWARF info to find the file/line/name for this address.
+        let (cx, stash) = match cache.mapping_for_lib(lib) {
+            Some((cx, stash)) => (cx, stash),
+            None => return,
+        };
+        let mut any_frames = false;
+        if let Ok(mut frames) = cx.find_frames(stash, addr as u64) {
+            while let Ok(Some(frame)) = frames.next() {
+                any_frames = true;
+                let name = match frame.function {
+                    Some(f) => Some(f.name.slice()),
+                    None => cx.object.search_symtab(addr as u64),
+                };
+                call(Symbol::Frame {
+                    addr: addr as *mut c_void,
+                    location: frame.location,
+                    name,
+                });
+            }
+        }
+        if !any_frames {
+            if let Some((object_cx, object_addr)) = cx.object.search_object_map(addr as u64) {
+                if let Ok(mut frames) = object_cx.find_frames(stash, object_addr) {
+                    while let Ok(Some(frame)) = frames.next() {
+                        any_frames = true;
+                        call(Symbol::Frame {
+                            addr: addr as *mut c_void,
+                            location: frame.location,
+                            name: frame.function.map(|f| f.name.slice()),
+                        });
+                    }
+                }
+            }
+        }
+        if !any_frames {
+            if let Some(name) = cx.object.search_symtab(addr as u64) {
+                call(Symbol::Symtab {
+                    addr: addr as *mut c_void,
+                    name,
+                });
+            }
+        }
+    });
+}
+
+pub enum Symbol<'a> {
+    /// We were able to locate frame information for this symbol, and
+    /// `addr2line`'s frame internally has all the nitty gritty details.
+    Frame {
+        addr: *mut c_void,
+        location: Option<addr2line::Location<'a>>,
+        name: Option<&'a [u8]>,
+    },
+    /// Couldn't find debug information, but we found it in the symbol table of
+    /// the elf executable.
+    Symtab { addr: *mut c_void, name: &'a [u8] },
+}
+
+impl Symbol<'_> {
+    pub fn name(&self) -> Option<SymbolName<'_>> {
+        match self {
+            Symbol::Frame { name, .. } => {
+                let name = name.as_ref()?;
+                Some(SymbolName::new(name))
+            }
+            Symbol::Symtab { name, .. } => Some(SymbolName::new(name)),
+        }
+    }
+
+    pub fn addr(&self) -> Option<*mut c_void> {
+        match self {
+            Symbol::Frame { addr, .. } => Some(*addr),
+            Symbol::Symtab { .. } => None,
+        }
+    }
+
+    pub fn filename_raw(&self) -> Option<BytesOrWideString<'_>> {
+        match self {
+            Symbol::Frame { location, .. } => {
+                let file = location.as_ref()?.file?;
+                Some(BytesOrWideString::Bytes(file.as_bytes()))
+            }
+            Symbol::Symtab { .. } => None,
+        }
+    }
+
+    pub fn filename(&self) -> Option<&Path> {
+        match self {
+            Symbol::Frame { location, .. } => {
+                let file = location.as_ref()?.file?;
+                Some(Path::new(file))
+            }
+            Symbol::Symtab { .. } => None,
+        }
+    }
+
+    pub fn lineno(&self) -> Option<u32> {
+        match self {
+            Symbol::Frame { location, .. } => location.as_ref()?.line,
+            Symbol::Symtab { .. } => None,
+        }
+    }
+
+    pub fn colno(&self) -> Option<u32> {
+        match self {
+            Symbol::Frame { location, .. } => location.as_ref()?.column,
+            Symbol::Symtab { .. } => None,
+        }
+    }
+}