From: Richard Levitte <levitte@openssl.org>
Date: Wed, 24 Aug 2016 11:03:20 +0000 (+0200)
Subject: Check for __GNUC__ to use GNU C atomic buildins
X-Git-Tag: OpenSSL_1_1_0~15
X-Git-Url: https://git.openssl.org/?p=openssl.git;a=commitdiff_plain;h=cb4b54c23b95e4638d643eb349d8d8dfa1cc2fd3

Check for __GNUC__ to use GNU C atomic buildins

Note: we trust any other compiler that fully implements GNU extension
to define __GNUC__

RT#4642

Reviewed-by: Andy Polyakov <appro@openssl.org>
---

diff --git a/crypto/threads_pthread.c b/crypto/threads_pthread.c
index 6f5e812d97..72ea83892b 100644
--- a/crypto/threads_pthread.c
+++ b/crypto/threads_pthread.c
@@ -109,9 +109,9 @@ int CRYPTO_THREAD_compare_id(CRYPTO_THREAD_ID a, CRYPTO_THREAD_ID b)
 
 int CRYPTO_atomic_add(int *val, int amount, int *ret, CRYPTO_RWLOCK *lock)
 {
-#ifdef __ATOMIC_RELAXED
+# if defined(__GNUC__) && defined(__ATOMIC_RELAXED)
     *ret = __atomic_add_fetch(val, amount, __ATOMIC_RELAXED);
-#else
+# else
     if (!CRYPTO_THREAD_write_lock(lock))
         return 0;
 
@@ -120,7 +120,7 @@ int CRYPTO_atomic_add(int *val, int amount, int *ret, CRYPTO_RWLOCK *lock)
 
     if (!CRYPTO_THREAD_unlock(lock))
         return 0;
-#endif
+# endif
 
     return 1;
 }