yet another C++ implementation bug to work around in Bison

[Paul Eggert]

Nelson H. F. Beebe reported the following problem with Bison 2.1 on
when built on Solaris 7 with /usr/sfw/bin/gcc.

/usr/sfw/bin/g++  -I/usr/local/include  -R/usr/local/lib -L/usr/local/lib -o 
calc++  calc++-scanner.o calc++.o calc++-driver.o calc++-parser.o  
Undefined                       first referenced
 symbol                             in file
std::_Rb_tree_insert_and_rebalance(bool, std::_Rb_tree_node_base*, 
std::_Rb_tree_node_base*, std::_Rb_tree_node_base&)calc++-driver.o
std::_Rb_tree_decrement(std::_Rb_tree_node_base*)calc++-driver.o

This resembles the problem reported by Alen P. of the University of
Waterloo in

http://groups.google.com/group/uw.cs.cs454/msg/4428997110facb36

He gave the following method to reproduce the problem:

http://groups.google.com/group/uw.cs.cs454/msg/056fa89a6ac954de

and I used that idea in the patch shown below, which I installed.
This may not fix the bug, but it shouldn't hurt to filter out C++
implementations that can't do maps properly.

One possible, more drastic fix that comes to mind is that we should
not use C++ at all, as part of our normal build procedure.  It often
causes build failures, and it's not really needed for Bison, so
perhaps the C++ stuff should all get moved to "make check".

2006-02-02  Paul Eggert  <address@hidden>

        More portability fixes for problems summarized by Nelson H. F. Beebe.

        * m4/cxx.m4 (BISON_TEST_FOR_WORKING_CXX_COMPILER): Check that
        '#include <map>' works and that you can apply ++ to iterators.

--- cxx.m4      2 Feb 2006 07:33:13 -0000       1.6
+++ cxx.m4      2 Feb 2006 23:53:07 -0000       1.7
@@ -29,10 +29,18 @@ AC_DEFUN([BISON_TEST_FOR_WORKING_CXX_COM
       [AC_LANG_PROGRAM(
         [#include <cstdlib>
          #include <iostream>
+         #include <map>
          #include <string>
          using namespace std;],
          [std::cerr << "";
-          cout << "";])],
+          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;])],
       [bison_cv_cxx_works=yes],
       [bison_cv_cxx_works=no],
       [bison_cv_cxx_works=cross])