1 files changed, 47 insertions, 0 deletions
diff --git a/third_party/rust/nix/src/ucontext.rs b/third_party/rust/nix/src/ucontext.rs
new file mode 100644
index 0000000000..b2a39f7699
--- /dev/null
+++ b/third_party/rust/nix/src/ucontext.rs
@@ -0,0 +1,47 @@
+#[cfg(not(target_env = "musl"))]
+use crate::errno::Errno;
+use crate::sys::signal::SigSet;
+#[cfg(not(target_env = "musl"))]
+use crate::Result;
+#[cfg(not(target_env = "musl"))]
+use std::mem;
+
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
+pub struct UContext {
+    context: libc::ucontext_t,
+}
+
+impl UContext {
+    #[cfg(not(target_env = "musl"))]
+    pub fn get() -> Result<UContext> {
+        let mut context = mem::MaybeUninit::<libc::ucontext_t>::uninit();
+        let res = unsafe { libc::getcontext(context.as_mut_ptr()) };
+        Errno::result(res).map(|_| unsafe {
+            UContext {
+                context: context.assume_init(),
+            }
+        })
+    }
+
+    #[cfg(not(target_env = "musl"))]
+    pub fn set(&self) -> Result<()> {
+        let res = unsafe {
+            libc::setcontext(&self.context as *const libc::ucontext_t)
+        };
+        Errno::result(res).map(drop)
+    }
+
+    pub fn sigmask_mut(&mut self) -> &mut SigSet {
+        unsafe {
+            &mut *(&mut self.context.uc_sigmask as *mut libc::sigset_t
+                as *mut SigSet)
+        }
+    }
+
+    pub fn sigmask(&self) -> &SigSet {
+        unsafe {
+            &*(&self.context.uc_sigmask as *const libc::sigset_t
+                as *const SigSet)
+        }
+    }
+}