Re: Symbol versioning question

[Steve Dunham <dunham@cse.msu.edu>]

Ulrich Drepper <drepper@cygnus.com> writes:

> Steve Dunham <dunham@cse.msu.edu> writes:
> 
> > A typical example is that it claims it can't find the symbol
> > "_popen@GLIBC_2.0" referenced by libgpm.so, where libc contains both
> > GLIBC_2.1 and GLIBC_2.0 versions of the symbol.

> There never was a symbol _popen.  If you want answers you have to be
> accurate.

Sorry, I had replaced the libraries on the machine in question.  I've
reproduced in on another machine, details are below.  (The
architecture is sparc.)

foo.c contains:

  main(){}

I compile with:

  gcc foo.c -lgpm

and get:

  /usr/lib/libgpm.so: undefined reference to `popen@@GLIBC_2.0'
  /usr/lib/libgpm.so: undefined reference to `pclose@@GLIBC_2.0'

This happened after moving from glibc-2.0.100 to glibc-2.0.105. 

I'm using binutils 2.9.1.0.15.

"objdump -T /lib/libc-2.0.105.so |grep popen " gives:

0000000000057dc4 g    DF .text  000000000000008c  GLIBC_2.1   _IO_popen
000000000005a154 g    DF .text  000000000000008c (GLIBC_2.0)  popen
0000000000057dc4 g    DF .text  000000000000008c  GLIBC_2.1   popen
000000000005a154 g    DF .text  000000000000008c (GLIBC_2.0)  _IO_popen

"objdump -T libgpm.so |grep popen" gives:

0000000000000000      DF *UND*  000000000000008c  GLIBC_2.0   popen

I get similar problems with:

  gcc foo.c -L/usr/X11R6/lib -lXpm -lX11

/usr/X11R6/lib/libXpm.so: undefined reference to `popen@@GLIBC_2.0'
/usr/X11R6/lib/libXpm.so: undefined reference to `pclose@@GLIBC_2.0'

and with "gcc foo.c -lstdc++":

/usr/lib/libstdc++.so: undefined reference to `_IO_proc_open@@GLIBC_2.0'
/usr/lib/libstdc++.so: undefined reference to `_IO_proc_close@@GLIBC_2.0'

Here, we have:

# objdump -T /lib/libc.so.6 |grep _IO_proc_
0000000000057e50 g    DF .text  00000000000000d0  GLIBC_2.1   _IO_proc_close
0000000000057ba8 g    DF .text  000000000000021c  GLIBC_2.1   _IO_proc_open
0000000000059f38 g    DF .text  000000000000021c (GLIBC_2.0)  _IO_proc_open
000000000005a1e0 g    DF .text  00000000000000d0 (GLIBC_2.0)  _IO_proc_close

and 

# objdump -T /usr/lib/libstdc++.so |grep _IO_proc_
0000000000000000      DF *UND*  000000000000021c  GLIBC_2.0   _IO_proc_open
0000000000000000      DF *UND*  00000000000000d0  GLIBC_2.0   _IO_proc_close

Let me know if you need any other info.


Steve
dunham@cse.msu.edu