1 files changed, 49 insertions, 0 deletions
diff --git a/ctr-std/src/sys/horizon/backtrace/tracing/backtrace_fn.rs b/ctr-std/src/sys/horizon/backtrace/tracing/backtrace_fn.rs
new file mode 100644
index 0000000..6293eeb
--- /dev/null
+++ b/ctr-std/src/sys/horizon/backtrace/tracing/backtrace_fn.rs
@@ -0,0 +1,49 @@
+// Copyright 2014-2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+/// As always - iOS on arm uses SjLj exceptions and
+/// _Unwind_Backtrace is even not available there. Still,
+/// backtraces could be extracted using a backtrace function,
+/// which thanks god is public
+///
+/// As mentioned in a huge comment block in `super::super`, backtrace
+/// doesn't play well with green threads, so while it is extremely nice and
+/// simple to use it should be used only on iOS devices as the only viable
+/// option.
+
+use io;
+use libc;
+use sys::backtrace::BacktraceContext;
+use sys_common::backtrace::Frame;
+
+#[inline(never)] // if we know this is a function call, we can skip it when
+                 // tracing
+pub fn unwind_backtrace(frames: &mut [Frame])
+    -> io::Result<(usize, BacktraceContext)>
+{
+    const FRAME_LEN: usize = 100;
+    assert!(FRAME_LEN >= frames.len());
+    let mut raw_frames = [::ptr::null_mut(); FRAME_LEN];
+    let nb_frames = unsafe {
+        backtrace(raw_frames.as_mut_ptr(), raw_frames.len() as libc::c_int)
+    } as usize;
+    for (from, to) in raw_frames.iter().zip(frames.iter_mut()).take(nb_frames) {
+        *to = Frame {
+            exact_position: *from as *mut u8,
+            symbol_addr: *from as *mut u8,
+            inline_context: 0,
+        };
+    }
+    Ok((nb_frames as usize, BacktraceContext))
+}
+
+extern {
+    fn backtrace(buf: *mut *mut libc::c_void, sz: libc::c_int) -> libc::c_int;
+}