[Boost-users] boost serialization compilation and WCHAR

From: Brian Budge (brian.budge_at_[hidden])
Date: 2006-05-09 23:38:48

Hi all -

I'm running into problems building the serialization library with gcc
4.1.  I tracked it down to a change in libstdc++ for gcc 4.1 from the
gcc 3.x libstdc++.

I'm sure there's a bug, but I'm not sure if it is a boost bug, a
libstdc++ bug, or a gcc 4.1 bug.

boost_1_33_1/boost/config/stdlib/libstdcpp3.hpp says:

#if !defined(_GLIBCPP_USE_WCHAR_T) && !defined(_GLIBCXX_USE_WCHAR_T)
#  define BOOST_NO_CWCHAR
#  define BOOST_NO_CWCTYPE
#  define BOOST_NO_STD_WSTRING
#  define BOOST_NO_STD_WSTREAMBUF
#endif

and indeed, with the 4.1 compiler, neither define is defined.  For 4.1 in file

/usr/lib/gcc/i686-pc-linux-gnu/4.1.0/include/g++-v4/i686-pc-linux-gnu/c++config.h

I have
/* Defined if vfwscanf exists. */
#define _GLIBCXX_HAVE_VFWSCANF 1

/* Defined if vswscanf exists. */
#define _GLIBCXX_HAVE_VSWSCANF 1

/* Defined if vwscanf exists. */
#define _GLIBCXX_HAVE_VWSCANF 1

/* Define to 1 if you have the <wchar.h> header file. */
#define _GLIBCXX_HAVE_WCHAR_H 1

/* Defined if wcstof exists. */
#define _GLIBCXX_HAVE_WCSTOF 1

/* Define to 1 if you have the <wctype.h> header file. */
#define _GLIBCXX_HAVE_WCTYPE_H 1

(no reference to USE_WCHAR_T)

and in

/usr/lib/gcc/i686-pc-linux-gnu/3.4.5/include/g++-v3/i686-pc-linux-gnu/bits/c++config.h

I have
// Define if code specialized for wchar_t should be used.
#define _GLIBCXX_USE_WCHAR_T 1

my fix would be one of three things:

1) in c++config.h
#define _GLIBCXX_USE_WCHAR_T

2) in libstdcpp3.hpp add a test for _GLIBCXX_HAVE_WCHAR_H:
#if !defined(_GLIBCPP_USE_WCHAR_T) && !defined(_GLIBCXX_USE_WCHAR_T)
&& !defined(_GLIBCXX_HAVE_WCHAR_H)
#  define BOOST_NO_CWCHAR
#  define BOOST_NO_CWCTYPE
#  define BOOST_NO_STD_WSTRING
#  define BOOST_NO_STD_WSTREAMBUF
#endif

3) somewhere else
#ifdef _GLIBCXX_HAVE_WCHAR_H
#define _GLIBCXX_USE_WCHAR_T
#endif

What do you guys think?

  Brian