Fixing shared library not run properly on Windows

Author: Neko-Box-Coder

Include/runcpp2/PlatformUtil.hpp

@@ -24,6 +24,9 @@ namespace runcpp2
                                 int& outReturnCode,
                                 std::string runDirectory = "");
 
+    #if defined(_WIN32)
+        std::string GetWindowsError();
+    #endif
 
     template <typename T>
     inline bool HasValueFromPlatformMap(const std::unordered_map<PlatformName, T>& map)

Src/runcpp2/PlatformUtil.cpp

@@ -127,3 +127,31 @@ bool runcpp2::RunCommandAndGetOutput(   const std::string& command,
 
     return true;
 }
+
+
+#if defined(_WIN32)
+    //Credit: https://stackoverflow.com/a/17387176
+    std::string runcpp2::GetWindowsError()
+    {
+        //Get the error message ID, if any.
+        DWORD errorMessageID = ::GetLastError();
+        if(errorMessageID == 0) {
+            return std::string(); //No error message has been recorded
+        }
+        
+        LPSTR messageBuffer = nullptr;
+    
+        //Ask Win32 to give us the string version of that message ID.
+        //The parameters we pass in, tell Win32 to create the buffer that holds the message for us (because we don't yet know how long the message string will be).
+        size_t size = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
+                                     NULL, errorMessageID, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPSTR)&messageBuffer, 0, NULL);
+        
+        //Copy the error message into a std::string.
+        std::string message(messageBuffer, size);
+        
+        //Free the Win32's string's buffer.
+        LocalFree(messageBuffer);
+                
+        return message;
+    }
+#endif

Src/runcpp2/runcpp2.cpp

@@ -18,6 +18,17 @@
 extern "C" const uint8_t DefaultScriptInfo[];
 extern "C" const size_t DefaultScriptInfo_size;
 
+//Use for SetDllDirectory
+#if defined(_WIN32)
+    #ifndef WIN32_LEAN_AND_MEAN
+        #define WIN32_LEAN_AND_MEAN
+    #endif
+    #ifndef NOMINMAX
+        #define NOMINMAX
+    #endif
+    #include <windows.h>
+#endif
+
 namespace
 {
     bool CreateLocalBuildDirectory( const std::string& scriptPath, 
@@ -131,6 +142,17 @@ namespace
 
         try
         {
+             //TODO: We might want to use unicode instead for the path
+             #if defined(_WIN32)
+                std::string sharedLibDir = compiledSharedLibPath.parent_path().string();
+                if(SetDllDirectoryA(sharedLibDir.c_str()) == FALSE)
+                {
+                    std::string lastError = runcpp2::GetWindowsError();
+                    ssLOG_ERROR("Failed to set DLL directory: " << lastError);
+                    return false;
+                }
+             #endif
+             
              sharedLib = std::unique_ptr<dylib>(new dylib(  compiledSharedLibPath.string(), 
                                                             dylib::no_filename_decorations));
         }