libc: cleanup atexit and put exits() in its own compilation unit

this avoids having to pull in atexit() and its dependencies
(lock(), unlock()) into every program. (as exits() is called
by _main() from main9.s).

1 files changed, 13 insertions, 0 deletions

diff --git a/sys/src/libc/port/exits.c b/sys/src/libc/port/exits.c
new file mode 100644
index 000000000..f4d76a6c6
--- /dev/null
+++ b/sys/src/libc/port/exits.c
@@ -0,0 +1,13 @@
+#include <u.h>
+#include <libc.h>
+
+void (*_onexit)(void);
+
+#pragma profile off
+
+void
+exits(char *s)
+{
+	if(_onexit != nil) (*_onexit)();
+	_exits(s);
+}