AC_CHECK_LIB and C++ classes

[f18m_217828]

Hi,
  I'm trying to write a test program to use in my configure.ac file 
which I process with autoconf 2.57.

I would like to create a check for testing the presence of the wxXml2 
library which is based on turn on the wxWidgets library.

So I wrote in my configure.ac:


[...]
AC_LANG(C++)

# MY CHECK
AC_MSG_CHECKING([for wxXml2 library...])
AC_LINK_IFELSE([AC_LANG_PROGRAM(
        [[#include <wx/xml2.h>]],
        [[wxXml2::Init();]])],
        ,
        [AC_MSG_ERROR([wxXml2 wrapper library not found, see 
http://wxcode.sourceforge.net/components/wxxml2/index.html])])
[...]


however, the configure script fails because reading the CONFIG.LOG file, 
I can see that the test program generated by the AC_LANG_PROGRAM macro 
is compiled with the command line:

    configure:3009: checking for wxXml2 library...
    configure:3028: g++ -o conftest -g -O2   conftest.cc -lxml2 -lgmp  >&5

obviously the compilation fails because the test program needs to be 
compiled with some additional C flags (e.g. -I/usr/local/include, 
-L/usr/local/lib -lwx -lwxbaseXXXX .... ).

However, I could not find any way to modify the options used by autoconf 
to compile test programs.... how can I do that ?

Does anyone managed to make such thing or something similar ?

Thanks indeed,
Francesco