Use `pkg-config' to detect BDW-GC at configure-time.

* configure.in: Use `PKG_CHECK_MODULES' to look for libgc.  This only
  works with GC 7.x+, which is what we want anyway.

diff --git a/configure.in b/configure.in
index 8f249bd..e23f2c6 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -1182,11 +1182,10 @@ main ()
 # Boehm's GC library
 #
 #--------------------------------------------------------------------
-AC_CHECK_LIB([gc], [GC_collect_a_little],
-  [LIBS="-lgc $LIBS"],
-  [AC_MSG_ERROR([`libgc' (Boehm's GC library) not found.])])
-AC_CHECK_HEADER([gc/gc.h], [],
-  [AC_MSG_ERROR([`libgc' (Boehm's GC library) header files not found.])])
+PKG_CHECK_MODULES([BDW_GC], [bdw-gc])
+
+CFLAGS="$BDW_GC_CFLAGS $CFLAGS"
+LIBS="$BDW_GC_LIBS $LIBS"
 
 # `GC_do_blocking ()' is available in GC 7.1 but not declared.
 AC_CHECK_FUNCS([GC_do_blocking])