--- a/aclocal.m4
+++ b/aclocal.m4
@@ -353,70 +353,6 @@
   fi
 ])
 dnl
-dnl
-dnl
-dnl OCTAVE_LANG_PROG_NO_CONFDEFS
-AC_DEFUN(OCTAVE_LANG_PROG_NO_CONFDEFS,
-[_AC_LANG_DISPATCH([AC_LANG_PROGRAM], _AC_LANG, [$@])])
-dnl
-dnl Check to see if GNU C++ barfs on #pragma interface/#pragma implementation.
-dnl
-dnl Note that we are using AC_LINK_IFELSE and OCTAVE_LANG_PROG_NO_CONFDEFS
-dnl to prevent autoconf from including confdefs.h ahead of the #pragma
-dnl interface/implementation line.
-dnl
-dnl OCTAVE_CXX_PRAGMA_INTERFACE_IMPLEMENTATION
-AC_DEFUN(OCTAVE_CXX_PRAGMA_INTERFACE_IMPLEMENTATION, [
-  AC_REQUIRE([AC_PROG_CXX])
-  AC_MSG_CHECKING([for C++ support for pragma interface/implementation])
-  AC_CACHE_VAL(octave_cv_cxx_pragma_interface_implementation, [
-    AC_LANG_PUSH(C++)
-    rm -f conftest.h
-    cat > conftest.h <<EOB
-#include <iostream>
-#pragma interface
-template <class T> class A
-{
-public:
-  A (void) {}
-  ~A (void);
-};
-
-class B : public A<int>
-{
-public:
-
-  B (void) : A<int> () { }
-};
-EOB
-    AC_LINK_IFELSE([OCTAVE_LANG_PROG_NO_CONFDEFS([#include "conftest.h"])],
-      [octave_pii_test_1=yes], [octave_pii_test_1=no])
-    rm -f conftest.h
-    cat > conftest.h <<EOB
-#pragma interface
-class A
-{
-public:
-  virtual ~A (void) {}
-};
-EOB
-    AC_LINK_IFELSE([OCTAVE_LANG_PROG_NO_CONFDEFS([#pragma implementation
-#include "conftest.h"])],
-      [octave_pii_test_2=yes], [octave_pii_test_2=no])
-    if test $octave_pii_test_1 = yes && test $octave_pii_test_2 = yes; then
-      octave_cv_cxx_pragma_interface_implementation=yes
-    else
-      octave_cv_cxx_pragma_interface_implementation=no
-    fi
-    AC_LANG_POP(C++)
-  ])
-  AC_MSG_RESULT($octave_cv_cxx_pragma_interface_implementation)
-  if test $octave_cv_cxx_pragma_interface_implementation = no; then
-    XTRA_CXXFLAGS="$XTRA_CXXFLAGS -DNO_PRAGMA_INTERFACE_IMPLEMENTATION=1"
-    AC_SUBST(XTRA_CXXFLAGS)
-  fi
-])
-dnl
 dnl Check for flex
 dnl
 AC_DEFUN(OCTAVE_PROG_FLEX, [