From ca1bbbfa47671a9b9aa341a1e5e5a89bf010e0dd Mon Sep 17 00:00:00 2001
From: Adam Sampson <ats@offog.org>
Date: Sat, 10 Apr 2010 21:46:34 +0000
Subject: [PATCH] -XImpredicativeTypes is only available on GHC 6.10+.

This also pulls out the duplicate -fglasgow-exts.
---
 Makefile.am  | 11 ++++++++---
 configure.ac |  1 +
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index 5d7558a..9b3661e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -62,13 +62,18 @@ if GHC68
 #GHC_OPTS += -XTypeSynonymInstances
 
 GHC_OPTS += -XUndecidableInstances
-GHC_OPTS += -XImpredicativeTypes
-GHC_OPTS += -fglasgow-exts
 GHC_OPTS += -fwarn-tabs -fwarn-monomorphism-restriction
 else
-GHC_OPTS +=	-fglasgow-exts -fallow-undecidable-instances
+# GHC 6.7 or earlier.
+GHC_OPTS += -fallow-undecidable-instances
 endif
 
+if GHC610
+GHC_OPTS += -XImpredicativeTypes
+endif
+
+GHC_OPTS += -fglasgow-exts
+
 tock$(EXEEXT): $(BUILT_SOURCES) $(tock_SOURCES) $(config_sources)
 	@MKDIR_P@ obj
 	ghc $(GHC_OPTS) -o tock$(EXEEXT) --make Main -odir obj -hidir obj
diff --git a/configure.ac b/configure.ac
index 94f5eae..837a1ad 100644
--- a/configure.ac
+++ b/configure.ac
@@ -88,6 +88,7 @@ fi
 AC_MSG_RESULT([OK])
 
 AM_CONDITIONAL([GHC68],[test $ghc_version -ge 6008000])
+AM_CONDITIONAL([GHC610],[test $ghc_version -ge 6010000])
 
 AC_DEFUN([AC_PICK_HASKELL_LIB_VER],
 [