Reorganize SHA1 checksum code.
diff --git a/lib/bcc/Script.h b/lib/bcc/Script.h
index c794c7b..8f16de5 100644
--- a/lib/bcc/Script.h
+++ b/lib/bcc/Script.h
@@ -53,6 +53,7 @@
     // ReadBC
     char const *sourceBC;
     char const *sourceResName;
+    unsigned char sourceSHA1[20];
     size_t sourceSize;
 
     // ReadModule