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, 2 insertions, 1 deletions

diff --git a/hash.cxx b/hash.cxx
index de8fd3d2..61caa356 100644
--- a/hash.cxx
+++ b/hash.cxx
@@ -223,7 +223,8 @@ find_stapconf_hash (systemtap_session& s, const hash& base)
   if (!create_hashdir(s, result, hashdir))
     return;
 
-  s.stapconf_path = hashdir + "/stapconf_" + result;
+  s.stapconf_name = "stapconf_" + result + ".h";
+  s.stapconf_path = hashdir + "/" + s.stapconf_name;
 }