updated build system

cmake/libraries/libsodium.cmake

@@ -1,12 +1,16 @@
 if(PROJECT_ENABLE_LIBSODIUM)
   if(PROJECT_BUILD)
-    add_definitions(-DPROJECT_ENABLE_LIBSODIUM)
-
     pkg_check_modules(SODIUM libsodium=${LIBSODIUM_VERSION} REQUIRED)
 
+    add_definitions(-DPROJECT_ENABLE_LIBSODIUM)
+
     include_directories(BEFORE SYSTEM ${SODIUM_INCLUDE_DIRS})
 
-    link_libraries(${SODIUM_LINK_LIBRARIES})
+    if(PROJECT_IS_MINGW_UNIX AND PROJECT_STATIC_LINK)
+      link_libraries(/mingw64/lib/libsodium.a)
+    else()
+      link_libraries(${SODIUM_LIBRARIES})
+    endif()
   elseif(NOT PROJECT_IS_MINGW OR CMAKE_HOST_WIN32)
     if(PROJECT_IS_MINGW)
       set(LIBSODIUM_TYPE mingw64)