1 files changed, 69 insertions, 0 deletions
diff --git a/libgo/runtime/go-defer.c b/libgo/runtime/go-defer.c
new file mode 100644
index 000000000..6425f0586
--- /dev/null
+++ b/libgo/runtime/go-defer.c
@@ -0,0 +1,69 @@
+/* go-defer.c -- manage the defer stack.
+
+   Copyright 2009 The Go Authors. All rights reserved.
+   Use of this source code is governed by a BSD-style
+   license that can be found in the LICENSE file.  */
+
+#include <stddef.h>
+
+#include "go-alloc.h"
+#include "go-panic.h"
+#include "go-defer.h"
+
+/* This function is called each time we need to defer a call.  */
+
+void
+__go_defer (void *frame, void (*pfn) (void *), void *arg)
+{
+  struct __go_defer_stack *n;
+
+  if (__go_panic_defer == NULL)
+    __go_panic_defer = ((struct __go_panic_defer_struct *)
+			__go_alloc (sizeof (struct __go_panic_defer_struct)));
+
+  n = (struct __go_defer_stack *) __go_alloc (sizeof (struct __go_defer_stack));
+  n->__next = __go_panic_defer->__defer;
+  n->__frame = frame;
+  n->__panic = __go_panic_defer->__panic;
+  n->__pfn = pfn;
+  n->__arg = arg;
+  n->__retaddr = NULL;
+  __go_panic_defer->__defer = n;
+}
+
+/* This function is called when we want to undefer the stack.  */
+
+void
+__go_undefer (void *frame)
+{
+  if (__go_panic_defer == NULL)
+    return;
+  while (__go_panic_defer->__defer != NULL
+	 && __go_panic_defer->__defer->__frame == frame)
+    {
+      struct __go_defer_stack *d;
+      void (*pfn) (void *);
+
+      d = __go_panic_defer->__defer;
+      pfn = d->__pfn;
+      d->__pfn = NULL;
+
+      if (pfn != NULL)
+	(*pfn) (d->__arg);
+
+      __go_panic_defer->__defer = d->__next;
+      __go_free (d);
+    }
+}
+
+/* This function is called to record the address to which the deferred
+   function returns.  This may in turn be checked by __go_can_recover.
+   The frontend relies on this function returning false.  */
+
+_Bool
+__go_set_defer_retaddr (void *retaddr)
+{
+  if (__go_panic_defer != NULL && __go_panic_defer->__defer != NULL)
+    __go_panic_defer->__defer->__retaddr = retaddr;
+  return 0;
+}