[Qemu-devel] [PATCH] configure: disallow ccache during compile tests

[John Snow <jsnow@redhat.com>]

If the user is using CCACHE during the configuration step,
it may interfere with some of the configuration tests,
particularly the "Is CCACHE interfering with macro analysis" step,
which is a bit of a poetic problem.

1) Disallow CCACHE from reading from the cache during configure,
   but don't disable it to allow us to see if it causes other problems.

2) Force off CCACHE_CPP2 during the ccache test to get a deterministic
   answer over whether or not we need to enable that feature later.

Signed-off-by: John Snow <jsnow@redhat.com>
---
 configure | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/configure b/configure
index 7a1d08d..9c726eb 100755
--- a/configure
+++ b/configure
@@ -8,6 +8,9 @@
 CLICOLOR_FORCE= GREP_OPTIONS=
 unset CLICOLOR_FORCE GREP_OPTIONS
 
+# Don't allow CCACHE, if present, to use cached results of compile tests!
+export CCACHE_RECACHE=yes
+
 # Temporary directory used for files created while
 # configure runs. Since it is in the build directory
 # we can safely blow away any previous version of it
@@ -4412,6 +4415,7 @@ fi
 # check if ccache is interfering with
 # semantic analysis of macros
 
+unset CCACHE_CPP2
 ccache_cpp2=no
 cat > $TMPC << EOF
 static const int Z = 1;
-- 
2.4.3