From 7ab42e075ff450251a6372cd9b26905e21be77a3 Mon Sep 17 00:00:00 2001
From: Amara Emerson <amara@apple.com>
Date: Wed, 31 Jul 2024 12:40:27 -0700
Subject: [PATCH] Forward declare OSSpinLockLock on MacOS since it's not
 shipped on the system.

Fixes build errors on some SDKs.

rdar://132607572
---
 compiler-rt/lib/rtsan/rtsan_interceptors.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/compiler-rt/lib/rtsan/rtsan_interceptors.cpp b/compiler-rt/lib/rtsan/rtsan_interceptors.cpp
index 3a65f9d3f779d..e8e7bdf17d822 100644
--- a/compiler-rt/lib/rtsan/rtsan_interceptors.cpp
+++ b/compiler-rt/lib/rtsan/rtsan_interceptors.cpp
@@ -17,6 +17,18 @@
 #include "rtsan/rtsan_context.h"
 
 #if SANITIZER_APPLE
+
+#if TARGET_OS_MAC
+// On MacOS OSSpinLockLock is deprecated and no longer present in the headers,
+// but the symbol still exists on the system. Forward declare here so we
+// don't get compilation errors.
+#include <stdint.h>
+extern "C" {
+typedef int32_t OSSpinLock;
+void OSSpinLockLock(volatile OSSpinLock *__lock);
+}
+#endif
+
 #include <libkern/OSAtomic.h>
 #include <os/lock.h>
 #endif