[libc-commits] [libc] [libc] Provide sys/queue.h (PR #78081)

[Nick Desaulniers via libc-commits]

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@@ -0,0 +1,20 @@
+//===-- Definition of the containerof macro -------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __LLVM_LIBC_MACROS_CONTAINEROF_MACRO_H
+#define __LLVM_LIBC_MACROS_CONTAINEROF_MACRO_H
+
+#include <llvm-libc-macros/offsetof-macro.h>
+
+#define __containerof(ptr, type, member)                                       \
+  ({                                                                           \
+    const __typeof(((type *)0)->member) *__ptr = ptr;                          \
+    (type *)(void *)((const char *)__ptr - offsetof(type, member));            \
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nickdesaulniers wrote:

Note: the Linux kernel has some updates to this macro, such as:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/include/linux/kernel.h?id=c7acec713d14c6ce8a20154f9dfda258d6bcad3b

I don't think we need those per-se at the moment, but I do wonder when we will.

https://github.com/llvm/llvm-project/pull/78081