Fix defer when not calling recover in function with named results.

From-SVN: r178905

libgo/runtime/go-defer.c

@@ -13,7 +13,7 @@
 /* This function is called each time we need to defer a call.  */
 
 void
-__go_defer (void *frame, void (*pfn) (void *), void *arg)
+__go_defer (_Bool *frame, void (*pfn) (void *), void *arg)
 {
   struct __go_defer_stack *n;
 
@@ -34,7 +34,7 @@ __go_defer (void *frame, void (*pfn) (void *), void *arg)
 /* This function is called when we want to undefer the stack.  */
 
 void
-__go_undefer (void *frame)
+__go_undefer (_Bool *frame)
 {
   if (__go_panic_defer == NULL)
     return;
@@ -53,6 +53,12 @@ __go_undefer (void *frame)
 
       __go_panic_defer->__defer = d->__next;
       __go_free (d);
+
+      /* Since we are executing a defer function here, we know we are
+	 returning from the calling function.  If the calling
+	 function, or one of its callees, paniced, then the defer
+	 functions would be executed by __go_panic.  */
+      *frame = 1;
     }
 }
 

libgo/runtime/go-defer.h

@@ -13,9 +13,10 @@ struct __go_defer_stack
   /* The next entry in the stack.  */
   struct __go_defer_stack *__next;
 
-  /* The frame pointer for the function which called this defer
-     statement.  */
-  void *__frame;
+  /* The stack variable for the function which called this defer
+     statement.  This is set to 1 if we are returning from that
+     function, 0 if we are panicing through it.  */
+  _Bool *__frame;
 
   /* The value of the panic stack when this function is deferred.
      This function can not recover this value from the panic stack.

libgo/runtime/go-panic.c

@@ -87,6 +87,12 @@ __go_panic (struct __go_empty_interface arg)
 	      /* __go_unwind_stack should not return.  */
 	      abort ();
 	    }
+
+	  /* Because we executed that defer function by a panic, and
+	     it did not call recover, we know that we are not
+	     returning from the calling function--we are panicing
+	     through it.  */
+	  *d->__frame = 0;
 	}
 
       __go_panic_defer->__defer = d->__next;

libgo/runtime/go-unwind.c

@@ -44,7 +44,7 @@ static const _Unwind_Exception_Class __go_exception_class =
    continue unwinding.  */
 
 void
-__go_check_defer (void *frame)
+__go_check_defer (_Bool *frame)
 {
   struct _Unwind_Exception *hdr;
 
@@ -103,8 +103,12 @@ __go_check_defer (void *frame)
       if (was_recovered)
 	{
 	  /* Just return and continue executing Go code.  */
+	  *frame = 1;
 	  return;
 	}
+
+      /* We are panicing through this function.  */
+      *frame = 0;
     }
   else if (__go_panic_defer->__defer != NULL
 	   && __go_panic_defer->__defer->__pfn == NULL
@@ -118,6 +122,10 @@ __go_check_defer (void *frame)
       d = __go_panic_defer->__defer;
       __go_panic_defer->__defer = d->__next;
       __go_free (d);
+
+      /* We are returning from this function.  */
+      *frame = 1;
+
       return;
     }