Document that undefined %prec identifier warnings will remain.

[bison.git] / m4 / cxx.m4

diff --git a/m4/cxx.m4 b/m4/cxx.m4
index a8eff8ee04fd016efff68af6481b5ef51c3f9a91..f9c6508e0db355d97b71f60baa554146b8cc49b4 100644 (file)
--- a/m4/cxx.m4
+++ b/m4/cxx.m4
@@ -1,11 +1,11 @@
 # -*- Autoconf -*-
 # Sanity-test a C++ compiler.
 #
-# Copyright (C) 2004, 2006 Free Software Foundation, Inc.
+# Copyright (C) 2004, 2006, 2009-2010 Free Software Foundation, Inc.
 #
-# This program is free software; you can redistribute it and/or modify
+# 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
-# the Free Software Foundation; either version 2 of the License, or
+# the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
@@ -14,9 +14,7 @@
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
-# 02110-1301  USA
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 # Written by Paul Eggert.
 
@@ -25,17 +23,29 @@ AC_DEFUN([BISON_TEST_FOR_WORKING_CXX_COMPILER],
  AC_CACHE_CHECK([whether $CXX builds executables that work],
    bison_cv_cxx_works,
    [AC_LANG_PUSH([C++])
-    AC_RUN_IFELSE(
+    bison_cv_cxx_works=no
+    AC_COMPILE_IFELSE(
       [AC_LANG_PROGRAM(
         [#include <cstdlib>
          #include <iostream>
+         #include <map>
          #include <string>
          using namespace std;],
          [std::cerr << "";
-          cout << "";])],
-      [bison_cv_cxx_works=yes],
-      [bison_cv_cxx_works=no],
-      [bison_cv_cxx_works=cross])
+          cout << "";
+         typedef std::pair<unsigned int, int> uipair;
+         std::map<unsigned int, int> m;
+         std::map<unsigned int, int>::iterator i;
+         m.insert (uipair (4, -4));
+         for (i = m.begin (); i != m.end (); ++i)
+           if (i->first != 4)
+             return 1;])],
+      [AS_IF([AC_TRY_COMMAND([$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_objext $LIBS >&AS_MESSAGE_LOG_FD])],
+        [AS_IF([test "$cross_compiling" = yes],
+           [bison_cv_cxx_works=cross],
+           [AS_IF([AC_TRY_COMMAND(./conftest$ac_exeext)],
+              [bison_cv_cxx_works=yes])])])
+       rm -f conftest$ac_exeext])
     AC_LANG_POP([C++])])
 
  case $bison_cv_cxx_works in