Adjust preprocessor symbols for Argon2

Author: utelle

src/argon2/include/argon2.h

@@ -31,12 +31,20 @@ extern "C" {
 #define ARGON2_PUBLIC __attribute__((visibility("default")))
 #define ARGON2_LOCAL __attribute__ ((visibility ("hidden")))
 #elif defined(_MSC_VER)
+#ifndef ARGON2_PUBLIC
 #define ARGON2_PUBLIC __declspec(dllexport)
+#endif
+#ifndef ARGON2_LOCAL
 #define ARGON2_LOCAL
+#endif
 #else
+#ifndef ARGON2_PUBLIC
 #define ARGON2_PUBLIC
+#endif
+#ifndef ARGON2_LOCAL
 #define ARGON2_LOCAL
 #endif
+#endif
 
 /*
  * Argon2 input parameter restrictions

src/argon2/libargon2.c

@@ -1,11 +1,15 @@
 #ifndef ARGON2_API
-#define ARGON2_API
+#define ARGON2_API static
 #endif
 
 #ifndef ARGON2_PRIVATE
 #define ARGON2_PRIVATE static
 #endif
 
+#ifndef ARGON2_PUBLIC
+#define ARGON2_PUBLIC static
+#endif
+
 #ifndef ARGON2_LOCAL
 #define ARGON2_LOCAL static
 #endif