add documentation

1 files changed, 26 insertions, 2 deletions

diff --git a/src/setjmp/siglongjmp.c b/src/setjmp/siglongjmp.c
index 44b6d6ed..06edc641 100644
--- a/src/setjmp/siglongjmp.c
+++ b/src/setjmp/siglongjmp.c
@@ -1,10 +1,34 @@
 #include <setjmp.h>
+#include "signal.h"
+
+/** restore calling environment with signal mask **/
 
 void siglongjmp(sigjmp_buf env, int val)
 {
-	(void)env; (void)val;
-	/* TODO */
+	/* restor signal mask */
+
+	return longjmp(env, val);
 }
+
+/***
+restores the environment, including the saved signal mask (if any), of a
+previous call to FUNCTION(sigsetjmp) and continues execution at the location of
+the call to FUNCTION(sigsetjmp).
+
+All objects previously accessible at the time of the call to FUNCTION(sigsetjmp)
+have the same values. Non-TYPE(volatile) objects of automatic storage duration
+that have changed since the call to FUNCTION(sigsetjmp) have intederminate
+values.
+
+When execution resumes at the point of the original call to FUNCTION(sigsetjmp),
+the value specified by ARGUMENT(val) is returned. If 0 is specified, then the
+return value is 1.
+***/
+
 /*
+UNDEFINED(There was no previous call to FUNCTION(setjmp))
+UNDEFINED(The function containing the previous call to FUNCTION(setjmp) is no longer executing)
+UNDEFINED(THIS() is called from a nested signal handler)
+
 POSIX(1)
 */