Try to fix building with gcc >= 4.6 on Darwin.

Eg, hydra builds have been failing for some time because (?) of this.
In gcc < 4.6, unrecognized -no-fo options just cause a warning.
In 4.6 and later, they cause an error.

* configure.in: (CPP): Do not unconditionally set it on Darwin.
Instead, try to test if -no-cpp-precomp is accepted.
(CPP_TEST_OPTIONS, SPECIFIED_CPP): New.

Fixes: debbugs:9755

1 files changed, 7 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 9bf19a1ee57..0495e917f21 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2012-05-16  Glenn Morris  <rgm@gnu.org>
+
+        * configure.in: Try to fix building with gcc >= 4.6 on Darwin.
+        (CPP): Do not unconditionally set it on Darwin.
+        Instead, try to test if -no-cpp-precomp is accepted.
+        (CPP_TEST_OPTIONS, SPECIFIED_CPP): New.  (Bug#9755)
+
 2012-05-15  Glenn Morris  <rgm@gnu.org>
 
         * Makefile.in (install-arch-dep): Replace use of MV_DIRS.