Enable session-wide code filtering

This will be used to hook to dwarf_builder to all functions and probes
so it can attempt @cast expansion.

* session.h (systemtap_session): Add a vector of update_visitors
that will act as filters for all probes and functions.
* elaborate.cxx (semantic_pass_symbols): Run probes and functions
through each registered code filter.

1 files changed, 5 insertions, 0 deletions

diff --git a/session.h b/session.h
index 6bcebd8b..735ef200 100644
--- a/session.h
+++ b/session.h
@@ -45,6 +45,7 @@ struct translator_output;
 struct unparser;
 struct semantic_error;
 struct module_cache;
+struct update_visitor;
 
 
 // XXX: a generalized form of this descriptor could be associated with
@@ -133,6 +134,10 @@ struct systemtap_session
   stapfile* user_file;
   std::vector<stapfile*> library_files;
 
+  // filters to run over all code before symbol resolution
+  //   e.g. @cast expansion
+  std::vector<update_visitor*> code_filters;
+
   // resolved globals/functions/probes for the run as a whole
   std::vector<stapfile*> files;
   std::vector<vardecl*> globals;