PR11246: Add more granular cache control

There are some module options that require us to disable caching for the
script, but before now this had a global effect.  There are some cache
objects, like tracepoint and @cast query modules, which we would like to
cache even when the script itself needs to be uncached.

* session.h (systemtap_session): New use_script_cache flag.
* main.cxx (main): -m & -k can just disable the script cache.  Failure to
  create the cache directories still disables all caching.
* hash.cxx (create_hashdir): Failure disables all caching.
* cache.cxx (add_to_cache): Failure only toggles the script caching. If
  the stapconf fails though, we don't need to block the .ko reuse.

1 files changed, 1 insertions, 0 deletions

diff --git a/session.h b/session.h
index 18d811e7..f45f6c77 100644
--- a/session.h
+++ b/session.h
@@ -127,6 +127,7 @@ struct systemtap_session
 
   // Cache data
   bool use_cache;
+  bool use_script_cache;
   std::string cache_path;
   std::string hash_path;
   std::string stapconf_path;