1 files changed, 44 insertions, 0 deletions
diff --git a/library/backtrace/src/symbolize/gimli/mmap_unix.rs b/library/backtrace/src/symbolize/gimli/mmap_unix.rs
new file mode 100644
index 000000000..5806c9f7e
--- /dev/null
+++ b/library/backtrace/src/symbolize/gimli/mmap_unix.rs
@@ -0,0 +1,44 @@
+use super::mystd::fs::File;
+use super::mystd::os::unix::prelude::*;
+use core::ops::Deref;
+use core::ptr;
+use core::slice;
+
+pub struct Mmap {
+    ptr: *mut libc::c_void,
+    len: usize,
+}
+
+impl Mmap {
+    pub unsafe fn map(file: &File, len: usize) -> Option<Mmap> {
+        let ptr = libc::mmap(
+            ptr::null_mut(),
+            len,
+            libc::PROT_READ,
+            libc::MAP_PRIVATE,
+            file.as_raw_fd(),
+            0,
+        );
+        if ptr == libc::MAP_FAILED {
+            return None;
+        }
+        Some(Mmap { ptr, len })
+    }
+}
+
+impl Deref for Mmap {
+    type Target = [u8];
+
+    fn deref(&self) -> &[u8] {
+        unsafe { slice::from_raw_parts(self.ptr as *const u8, self.len) }
+    }
+}
+
+impl Drop for Mmap {
+    fn drop(&mut self) {
+        unsafe {
+            let r = libc::munmap(self.ptr, self.len);
+            debug_assert_eq!(r, 0);
+        }
+    }
+}