1 files changed, 25 insertions, 4 deletions
diff --git a/ext/ffi_c/DynamicLibrary.c b/ext/ffi_c/DynamicLibrary.c
index 2e0bf4b..bcbc8de 100644
--- a/ext/ffi_c/DynamicLibrary.c
+++ b/ext/ffi_c/DynamicLibrary.c
@@ -61,6 +61,7 @@ static size_t library_memsize(const void *);
 static VALUE symbol_allocate(VALUE klass);
 static VALUE symbol_new(VALUE library, void* address, VALUE name);
 static void symbol_mark(void *data);
+static void symbol_compact(void *data);
 static size_t symbol_memsize(const void *data);
 
 static const rb_data_type_t rbffi_library_data_type = {
@@ -81,6 +82,7 @@ static const rb_data_type_t library_symbol_data_type = {
         .dmark = symbol_mark,
         .dfree = RUBY_TYPED_DEFAULT_FREE,
         .dsize = symbol_memsize,
+        ffi_compact_callback( symbol_compact )
     },
     .parent = &rbffi_pointer_data_type,
     // IMPORTANT: WB_PROTECTED objects must only use the RB_OBJ_WRITE()
@@ -223,8 +225,19 @@ dl_open(const char* name, int flags)
 static void
 dl_error(char* buf, int size)
 {
-    FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM, NULL, GetLastError(),
-            0, buf, size, NULL);
+    // Get the last error code
+    DWORD error = GetLastError();
+
+    // Get the associated message
+    LPSTR message = NULL;
+    FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER, 
+                   NULL, error, 0, (LPSTR)&message, 0, NULL);
+
+    // Update the passed in buffer
+    snprintf(buf, size, "Failed with error %d: %s", error, message);
+
+    // Free the allocated message
+    LocalFree(message);
 }
 #endif
 
@@ -273,8 +286,16 @@ static void
 symbol_mark(void *data)
 {
     LibrarySymbol *sym = (LibrarySymbol *)data;
-    rb_gc_mark(sym->base.rbParent);
-    rb_gc_mark(sym->name);
+    rb_gc_mark_movable(sym->base.rbParent);
+    rb_gc_mark_movable(sym->name);
+}
+
+static void
+symbol_compact(void *data)
+{
+    LibrarySymbol *sym = (LibrarySymbol *)data;
+    ffi_gc_location(sym->base.rbParent);
+    ffi_gc_location(sym->name);
 }
 
 static size_t