ucontext.h: Import from musl

Copied as is from the official musl git mirror
git://git.musl-libc.org/musl, commit 6fcb440d.

Signed-off-by: Charalampos Mainas <Charalampos.Mainas@neclab.eu>
Reviewed-by: Costin Lupu <costin.lupu@cs.pub.ro>

diff --git a/musl-imported/include/ucontext.h b/musl-imported/include/ucontext.h
new file mode 100644 (file)
index 0000000..3bb776e
--- /dev/null
+++ b/musl-imported/include/ucontext.h
@@ -0,0 +1,25 @@
+#ifndef _UCONTEXT_H
+#define _UCONTEXT_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <features.h>
+
+#include <signal.h>
+
+#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+#define NGREG (sizeof(gregset_t)/sizeof(greg_t))
+#endif
+
+struct __ucontext;
+
+int  getcontext(struct __ucontext *);
+void makecontext(struct __ucontext *, void (*)(void), int, ...);
+int  setcontext(const struct __ucontext *);
+int  swapcontext(struct __ucontext *, const struct __ucontext *);
+
+#ifdef __cplusplus
+}
+#endif
+#endif