Ensure that the C++ compiler used for testing actually works on a

simple test program; if not, skip the C++-related tests.

tests/atlocal.in

@@ -1,6 +1,6 @@
 # @configure_input@					-*- shell-script -*-
 # Configurable variable values for Bison test suite.
-# Copyright (C) 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
+# Copyright (C) 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
 
 # We need a C compiler.
 CC='@CC@'
@@ -14,9 +14,12 @@ CPPFLAGS="-DHAVE_CONFIG_H=1 -I$abs_top_builddir @CPPFLAGS@"
 # Is the compiler GCC?
 GCC='@GCC@'
 
-# The GCC C++ compiler.
+# The C++ compiler.
 CXX='@CXX@'
 
+# If 'exit 77'; skip all C++ tests; otherwise ':'.
+BISON_CXX_WORKS='@BISON_CXX_WORKS@'
+
 # We want no optimization with C++, too.
 CXXFLAGS='@O0CFLAGS@ @WARNING_CXXFLAGS@ @WERROR_CFLAGS@'
 

tests/local.at

@@ -1,7 +1,7 @@
 # Process this -*- Autotest -*- file with autom4te.
 
 # Macros for the GNU Bison Test suite.
-# Copyright (C) 2003 Free Software Foundation, Inc.
+# Copyright (C) 2003, 2004 Free Software Foundation, Inc.
 
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -175,10 +175,10 @@ m4_define([AT_COMPILE],
 
 # AT_COMPILE_CXX(OUTPUT, [SOURCES = OUTPUT.c])
 # --------------------------------------------
-# If the C++ compiler is not defined, ignore the test.
+# If the C++ compiler does not work, ignore the test.
 m4_define([AT_COMPILE_CXX],
 [AT_KEYWORDS(c++)
-AT_CHECK([$CXX --version || exit 77], 0, ignore, ignore)
+AT_CHECK([$BISON_CXX_WORKS], 0, ignore, ignore)
 AT_CHECK([$CXX $CXXFLAGS $CPPFLAGS m4_default([$2], [$1.c]) -o $1],
          0, [ignore], [ignore])])