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/main.cxx b/main.cxx
index 31ecda33..dbb2a306 100644
--- a/main.cxx
+++ b/main.cxx
@@ -355,6 +355,7 @@ main (int argc, char * const argv [])
   s.buffer_size = 0;
   s.last_pass = 5;
   s.module_name = "stap_" + stringify(getpid());
+  s.stapconf_name = "stapconf_" + stringify(getpid()) + ".h";
   s.output_file = ""; // -o FILE
   s.keep_tmpdir = false;
   s.cmd = "";