[gnome-builder/wip/libide] build: check for clang during configure

[Christian Hergert <chergert src gnome org>]

commit f55174e1fb25ab743a13a29d065116e5df5309fc
Author: Christian Hergert <christian hergert me>
Date:   Wed Feb 11 14:16:50 2015 -0800

    build: check for clang during configure

 build/autotools/autoconf.d/50_dependencies.post-am |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/build/autotools/autoconf.d/50_dependencies.post-am 
b/build/autotools/autoconf.d/50_dependencies.post-am
index 0b336bb..dae1c53 100644
--- a/build/autotools/autoconf.d/50_dependencies.post-am
+++ b/build/autotools/autoconf.d/50_dependencies.post-am
@@ -6,3 +6,10 @@ PKG_CHECK_MODULES(LIBIDE, [gio-2.0 >= 2.43.4
                            gio-unix-2.0 >= 2.43.4
                            libgit2-glib-1.0 >= 0.0.24])
 
+
+AC_PATH_PROG([LLVM_CONFIG], [llvm-config])
+AS_IF([test "x$LLVM_CONFIG" = "x"],[
+    AC_MSG_ERROR([Failed to locate the llvm-config program.])
+])
+CLANG_LDFLAGS=`$LLVM_CONFIG --ldflags`
+AC_SUBST([CLANG_LDFLAGS])