+AC_MSG_CHECKING(for xlc)
+AC_TRY_COMPILE([],[
+ #ifndef __xlC__
+ # error
+ #endif
+], [compiler_xlc=yes], [compiler_xlc=no])
+AC_MSG_RESULT($compiler_xlc)
+AM_CONDITIONAL(COMPILER_XLC,test $compiler_xlc = yes)
+if test $compiler_xlc = yes -a "$powerpc_darwin" = true; then
+ # the darwin stack-frame-walking code is completely broken on xlc
+ AC_DEFINE(DARWIN_DONT_PARSE_STACK)
+fi
+