support LOCK_DEBUG for Windows

ghc/includes/OSThreads.h

@@ -90,6 +90,19 @@ typedef DWORD ThreadLocalKey;
 #if USE_CRITICAL_SECTIONS
 
 typedef CRITICAL_SECTION Mutex;
+
+#ifdef LOCK_DEBUG
+
+#define ACQUIRE_LOCK(mutex) \
+  debugBelch("ACQUIRE_LOCK(0x%p) %s %d\n", mutex,__FILE__,__LINE__); \
+  EnterCriticalSection(mutex)
+#define RELEASE_LOCK(mutex) \
+  debugBelch("RELEASE_LOCK(0x%p) %s %d\n", mutex,__FILE__,__LINE__); \
+  LeaveCriticalSection(mutex)
+#define ASSERT_LOCK_HELD(mutex) /* nothing */
+
+#else
+
 #define ACQUIRE_LOCK(mutex)  EnterCriticalSection(mutex)
 #define RELEASE_LOCK(mutex)  LeaveCriticalSection(mutex)
 
@@ -97,6 +110,8 @@ typedef CRITICAL_SECTION Mutex;
 // the right thing.
 #define ASSERT_LOCK_HELD(mutex) /* nothing */
 
+#endif
+
 #else
 
 typedef HANDLE Mutex;