Clean up the autoconf caching

This makes the stapconf caching process quite a bit more transparent.
The options are now cached in a header file as #defines, and this header
file is a normal build dependency instead of calling so many make
$(shell ...) commands.

  * buildrun.cxx (compile_pass): Pull in autoconf options in a header
  of #defines rather than -DXXX, and make that header a build dependency.
  * buildrun.cxx (output_autoconf): New function to consolidate the
  computation of each autoconf test.
  * cache.cxx (add_to_cache, get_from_cache, clean_cache): Start treating
  the stapconf header as a first-class cached item.
  * cache.h: Move definitions of things only needed in cache.cxx
  * hash.cxx (find_stapconf_hash): Generate stapconf_name as a .h now.
  * main.cxx (main): Default the stapconf_name based on getpid().

1 files changed, 1 insertions, 0 deletions

diff --git a/session.h b/session.h
index c55310d3..6bcebd8b 100644
--- a/session.h
+++ b/session.h
@@ -86,6 +86,7 @@ struct systemtap_session
   std::string runtime_path;
   std::string data_path;
   std::string module_name;
+  std::string stapconf_name;
   std::string output_file;
   std::string cmd;
   int target_pid;