verify: Clarify assertion message.

[libfirm] / ir / ir / irhooks.c

diff --git a/ir/ir/irhooks.c b/ir/ir/irhooks.c
index 0341f7d..b32b91e 100644 (file)
--- a/ir/ir/irhooks.c
+++ b/ir/ir/irhooks.c
@@ -1,43 +1,63 @@
 /*
- * Project:     libFIRM
- * File name:   ir/ir/irhooks.c
- * Purpose:     Generic hooks for various libFirm functions.
- * Author:      Michael Beck
- * Created:
- * CVS-ID:      $Id$
- * Copyright:   (C) 1998-2005 Universität Karlsruhe
- * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
+ * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
  */
 
 /**
- * @file irhooks.c
- *
- * Generic hooks for various libFirm functions.
- *
- * @author Michael Beck
+ * @file
+ * @brief    Generic hooks for various libFirm functions.
+ * @author   Michael Beck
  */
-#ifdef HAVE_CONFIG_H
 #include "config.h"
-#endif
 
-#include "irhooks.h"
+#include <assert.h>
 
-#ifdef FIRM_ENABLE_HOOKS
+#include "irhooks.h"
 
-/* the hooks */
 hook_entry_t *hooks[hook_last];
 
-/* register a hook */
-void register_hook(hook_type_t hook, hook_entry_t *entry) {
+void register_hook(hook_type_t hook, hook_entry_t *entry)
+{
+  /* check if a hook function is specified. It's a union, so no matter which one */
   if (! entry->hook._hook_turn_into_id)
     return;
 
+  /* hook should not be registered yet */
+  assert(entry->next == NULL && hooks[hook] != entry);
+
   entry->next = hooks[hook];
   hooks[hook] = entry;
 }
 
-#else
+void unregister_hook(hook_type_t hook, hook_entry_t *entry)
+{
+  hook_entry_t *p;
 
-void register_hook(hook_type_t hook, hook_entry_t *entry) {}
+  if (hooks[hook] == entry) {
+    hooks[hook] = entry->next;
+    entry->next = NULL;
+    return;
+  }
+
+  for (p = hooks[hook]; p && p->next != entry; p = p->next) {
+  }
 
-#endif /* FIRM_ENABLE_HOOKS */
+  if (p) {
+    p->next     = entry->next;
+    entry->next = NULL;
+  }
+}