1 files changed, 107 insertions, 0 deletions
diff --git a/js/src/jsclist.h b/js/src/jsclist.h
new file mode 100644
index 000000000..b8455152c
--- /dev/null
+++ b/js/src/jsclist.h
@@ -0,0 +1,107 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef jsclist_h
+#define jsclist_h
+
+#include "jstypes.h"
+
+/*
+** Circular linked list
+*/
+typedef struct JSCListStr {
+    struct JSCListStr* next;
+    struct JSCListStr* prev;
+} JSCList;
+
+/*
+** Insert element "_e" into the list, before "_l".
+*/
+#define JS_INSERT_BEFORE(_e,_l)  \
+    JS_BEGIN_MACRO               \
+        (_e)->next = (_l);       \
+        (_e)->prev = (_l)->prev; \
+        (_l)->prev->next = (_e); \
+        (_l)->prev = (_e);       \
+    JS_END_MACRO
+
+/*
+** Insert element "_e" into the list, after "_l".
+*/
+#define JS_INSERT_AFTER(_e,_l)   \
+    JS_BEGIN_MACRO               \
+        (_e)->next = (_l)->next; \
+        (_e)->prev = (_l);       \
+        (_l)->next->prev = (_e); \
+        (_l)->next = (_e);       \
+    JS_END_MACRO
+
+/*
+** Return the element following element "_e"
+*/
+#define JS_NEXT_LINK(_e)         \
+        ((_e)->next)
+/*
+** Return the element preceding element "_e"
+*/
+#define JS_PREV_LINK(_e)         \
+        ((_e)->prev)
+
+/*
+** Append an element "_e" to the end of the list "_l"
+*/
+#define JS_APPEND_LINK(_e,_l) JS_INSERT_BEFORE(_e,_l)
+
+/*
+** Insert an element "_e" at the head of the list "_l"
+*/
+#define JS_INSERT_LINK(_e,_l) JS_INSERT_AFTER(_e,_l)
+
+/* Return the head/tail of the list */
+#define JS_LIST_HEAD(_l) (_l)->next
+#define JS_LIST_TAIL(_l) (_l)->prev
+
+/*
+** Remove the element "_e" from it's circular list.
+*/
+#define JS_REMOVE_LINK(_e)             \
+    JS_BEGIN_MACRO                     \
+        (_e)->prev->next = (_e)->next; \
+        (_e)->next->prev = (_e)->prev; \
+    JS_END_MACRO
+
+/*
+** Remove the element "_e" from it's circular list. Also initializes the
+** linkage.
+*/
+#define JS_REMOVE_AND_INIT_LINK(_e)    \
+    JS_BEGIN_MACRO                     \
+        (_e)->prev->next = (_e)->next; \
+        (_e)->next->prev = (_e)->prev; \
+        (_e)->next = (_e);             \
+        (_e)->prev = (_e);             \
+    JS_END_MACRO
+
+/*
+** Return non-zero if the given circular list "_l" is empty, zero if the
+** circular list is not empty
+*/
+#define JS_CLIST_IS_EMPTY(_l) \
+    bool((_l)->next == (_l))
+
+/*
+** Initialize a circular list
+*/
+#define JS_INIT_CLIST(_l)  \
+    JS_BEGIN_MACRO         \
+        (_l)->next = (_l); \
+        (_l)->prev = (_l); \
+    JS_END_MACRO
+
+#define JS_INIT_STATIC_CLIST(_l) \
+    {(_l), (_l)}
+
+#endif /* jsclist_h */