Re: Problem with istream.seekg() and __mbstate_t

[Craig Rodrigues <rodrigc at mediaone dot net>]

Hi,

According to this message on the glibc mailing list:
http://sources.redhat.com/ml/libc-alpha/2001-02/msg00150.html

the change between glibc 2.1 and glibc 2.2
in terms of mbstate_t vs. __mbstate_t is known.  This directly
affects libstdc++-v3.

So, for the packagers of gcc and libstdc++, ie. Redhat, Mandrake,
etc., etc., can you please make sure that your rpm spec files
have a dependency on the glibc version that libstdc++ was compiled against?

CodeSourcery, can you do this with your daily gcc snapshots?

Thanks.

-- 
Craig Rodrigues        
http://www.gis.net/~craigr    
rodrigc@mediaone.net          





On Sun, Feb 11, 2001 at 10:54:48PM -0500, Craig Rodrigues wrote:
> Hi,
> 
> Compiler: gcc version 2.97 20010211 (experimental)
> Glibc version: GNU C Library stable release version 2.2.1
>                Compiled by GNU CC version 2.96 20000731 (Red Hat Linux 7.0).
>                Compiled on a Linux 2.4.0-0.43.6 system on 2001-01-15. 
> 
> OS:  Redhat Linux 7.0
> 
> 
> Problem:  The following code snippet fails to link:
> 
> ===========================================================================
> #include <iostream>
> using namespace std;
> 
> void seek(istream& i)
> {
>      unsigned long pos = 35;
>      i.seekg(pos);
> }
> 
> int main(int, char **) { return 0; }
> ===========================================================================
> 
> % g++ d.cc
> /tmp/ccx9JhBd.o: In function `seek(std::istream&)':
> /tmp/ccx9JhBd.o(.text+0x3c): undefined reference to `std::istream::seekg(std::fpos<__mbstate_t>)'
> collect2: ld returned 1 exit status
> 
> Doing an nm on libstdc++.so.3, the closest symbol I could find was:
> 00053288 W std::istream::seekg(std::fpos<mbstate_t>)
> 
> __mbstate_t is not defined anywhere in the libstdc++ sources, but
> it seems to be defined in the glibc sources.
> 
> How can I solve this problem?
> 
> Thanks.
> -- 
> Craig Rodrigues        
> http://www.gis.net/~craigr    
> rodrigc@mediaone.net