1 files changed, 17 insertions, 0 deletions
diff --git a/devel/wasi-libc/files/llvm21/__stddef_offsetof.h b/devel/wasi-libc/files/llvm21/__stddef_offsetof.h
new file mode 100644
index 000000000000..84172c6cd273
--- /dev/null
+++ b/devel/wasi-libc/files/llvm21/__stddef_offsetof.h
@@ -0,0 +1,17 @@
+/*===---- __stddef_offsetof.h - Definition of offsetof ---------------------===
+ *
+ * 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
+ *
+ *===-----------------------------------------------------------------------===
+ */
+
+/*
+ * When -fbuiltin-headers-in-system-modules is set this is a non-modular header
+ * and needs to behave as if it was textual.
+ */
+#if !defined(offsetof) ||                                                      \
+    (__has_feature(modules) && !__building_module(_Builtin_stddef))
+#define offsetof(t, d) __builtin_offsetof(t, d)
+#endif