http://www.databaseusers.com/article/6047407/Bug%3A+Build+failure+on+Linux+with+clang+libc%2B%2B+(atomic+issues)
https://gist.githubusercontent.com/LnL7/5153b251fd525fe15de69b67e63a6075/raw/7778e9364679093a32dec2908656738e16b6bdcb/clang.patch

diff --git src/dbinc/atomic.h src/dbinc/atomic.h
index 1c714b3..5eb0003 100755
--- src/dbinc/atomic.h
+++ src/dbinc/atomic.h
@@ -73,7 +73,7 @@ typedef struct {
  * These have no memory barriers; the caller must include them when necessary.
  */
 #define	atomic_read(p)		((p)->value)
-#define	atomic_init(p, val)	((p)->value = (val))
+#define	atomic_init_db(p, val)	((p)->value = (val))
 
 #ifdef HAVE_ATOMIC_SUPPORT
 
@@ -226,7 +226,7 @@ static inline int __atomic_compare_exchange_int(
 #define	atomic_add(env, p, val)	((p)->value += (val))
 #define	atomic_compare_exchange(env, p, oldval, newval)		\
 	(DB_ASSERT(env, atomic_read(p) == (oldval)),		\
-	atomic_init(p, (newval)), 1)
+	atomic_init_db(p, (newval)), 1)
 #else
 #define	atomic_inc(env, p)	__atomic_add_int(env, p, 1)
 #define	atomic_dec(env, p)	__atomic_add_int(env, p, -1)
diff --git src/mp/mp_fget.c src/mp/mp_fget.c
index 66b9a65..03b474f 100755
--- src/mp/mp_fget.c
+++ src/mp/mp_fget.c
@@ -650,7 +650,7 @@ alloc:		/* Allocate a new buffer header and data space. */
 
 		/* Initialize enough so we can call __memp_bhfree. */
 		alloc_bhp->flags = 0;
-		atomic_init(&alloc_bhp->ref, 1);
+		atomic_init_db(&alloc_bhp->ref, 1);
 #ifdef DIAGNOSTIC
 		if ((uintptr_t)alloc_bhp->buf & (sizeof(size_t) - 1)) {
 			__db_errx(env, DB_STR("3025",
@@ -965,7 +965,7 @@ alloc:		/* Allocate a new buffer header and data space. */
 			MVCC_MPROTECT(bhp->buf, mfp->pagesize,
 			    PROT_READ);
 
-		atomic_init(&alloc_bhp->ref, 1);
+		atomic_init_db(&alloc_bhp->ref, 1);
 		MUTEX_LOCK(env, alloc_bhp->mtx_buf);
 		alloc_bhp->priority = bhp->priority;
 		alloc_bhp->pgno = bhp->pgno;
diff --git src/mp/mp_mvcc.c src/mp/mp_mvcc.c
index 11cd164..dfcdc2b 100755
--- src/mp/mp_mvcc.c
+++ src/mp/mp_mvcc.c
@@ -281,7 +281,7 @@ __memp_bh_freeze(dbmp, infop, hp, bhp, need_frozenp)
 #else
 	memcpy(frozen_bhp, bhp, SSZA(BH, buf));
 #endif
-	atomic_init(&frozen_bhp->ref, 0);
+	atomic_init_db(&frozen_bhp->ref, 0);
 	if (mutex != MUTEX_INVALID)
 		frozen_bhp->mtx_buf = mutex;
 	else if ((ret = __mutex_alloc(env, MTX_MPOOL_BH,
@@ -440,7 +440,7 @@ __memp_bh_thaw(dbmp, infop, hp, frozen_bhp, alloc_bhp)
 #endif
 		alloc_bhp->mtx_buf = mutex;
 		MUTEX_LOCK(env, alloc_bhp->mtx_buf);
-		atomic_init(&alloc_bhp->ref, 1);
+		atomic_init_db(&alloc_bhp->ref, 1);
 		F_CLR(alloc_bhp, BH_FROZEN);
 	}
 
diff --git src/mp/mp_region.c src/mp/mp_region.c
index e006c87..11b157d 100755
--- src/mp/mp_region.c
+++ src/mp/mp_region.c
@@ -278,7 +278,7 @@ __memp_init(env, dbmp, reginfo_off, htab_buckets, max_nreg)
 			     MTX_MPOOL_FILE_BUCKET, 0, &htab[i].mtx_hash)) != 0)
 				return (ret);
 			SH_TAILQ_INIT(&htab[i].hash_bucket);
-			atomic_init(&htab[i].hash_page_dirty, 0);
+			atomic_init_db(&htab[i].hash_page_dirty, 0);
 		}
 
 		mtx_base = mtx_prev = MUTEX_INVALID;
@@ -332,7 +332,7 @@ no_prealloc:
 		    DB_MUTEX_SHARED, &hp->mtx_hash)) != 0)
 			return (ret);
 		SH_TAILQ_INIT(&hp->hash_bucket);
-		atomic_init(&hp->hash_page_dirty, 0);
+		atomic_init_db(&hp->hash_page_dirty, 0);
 #ifdef HAVE_STATISTICS
 		hp->hash_io_wait = 0;
 		hp->hash_frozen = hp->hash_thawed = hp->hash_frozen_freed = 0;
diff --git src/mutex/mut_method.c src/mutex/mut_method.c
index 5d4b145..19a2489 100755
--- src/mutex/mut_method.c
+++ src/mutex/mut_method.c
@@ -479,7 +479,7 @@ __atomic_compare_exchange_int(env, v, oldval, newval)
 	MUTEX_LOCK(env, mtx);
 	ret = atomic_read(v) == oldval;
 	if (ret)
-		atomic_init(v, newval);
+		atomic_init_db(v, newval);
 	MUTEX_UNLOCK(env, mtx);
 
 	return (ret);
diff --git src/mutex/mut_tas.c src/mutex/mut_tas.c
index a620aa8..046585c 100755
--- src/mutex/mut_tas.c
+++ src/mutex/mut_tas.c
@@ -43,7 +43,7 @@ __db_tas_mutex_init(env, mutex, flags)
 
 #ifdef HAVE_SHARED_LATCHES
 	if (F_ISSET(mutexp, DB_MUTEX_SHARED))
-		atomic_init(&mutexp->sharecount, 0);
+		atomic_init_db(&mutexp->sharecount, 0);
 	else
 #endif
 	if (MUTEX_INIT(&mutexp->tas)) {
@@ -617,7 +617,7 @@ was_not_locked:
 			F_CLR(mutexp, DB_MUTEX_LOCKED);
 			/* Flush flag update before zeroing count */
 			MEMBAR_EXIT();
-			atomic_init(&mutexp->sharecount, 0);
+			atomic_init_db(&mutexp->sharecount, 0);
 		} else {
 			DB_ASSERT(env, sharecount > 0);
 			MEMBAR_EXIT();