add check for stdatomic.h

Author: JacobBarthelmeh

configure.ac

@@ -100,7 +100,7 @@ else
 fi
 
 
-AC_CHECK_HEADERS([arpa/inet.h fcntl.h limits.h netdb.h netinet/in.h stddef.h time.h sys/ioctl.h sys/socket.h sys/time.h errno.h sys/un.h])
+AC_CHECK_HEADERS([arpa/inet.h fcntl.h limits.h netdb.h netinet/in.h stddef.h time.h sys/ioctl.h sys/socket.h sys/time.h errno.h sys/un.h stdatomic.h])
 AC_CHECK_LIB([network],[socket])
 AC_C_BIGENDIAN
 AC_C___ATOMIC

wolfssl/wolfcrypt/wc_port.h

@@ -307,10 +307,12 @@
     #define WOLFSSL_ATOMIC_OPS
 #endif
 #else
+    #ifdef HAVE_STDATOMIC_H
     /* Default C Implementation */
     #include <stdatomic.h>
     typedef atomic_int wolfSSL_Atomic_Int;
     #define WOLFSSL_ATOMIC_OPS
+    #endif /* HAVE_STDATOMIC_H */
 #endif
 #elif defined(_MSC_VER)
     /* Use MSVC compiler intrinsics for atomic ops */