[oclug] glibc gcc symbol strangeness
Gilles J. Seguin
segg at infonet.ca
Wed Mar 6 00:30:56 EST 2002
Johnathan Hicks wrote:
> I have gcc 2.96 installed as well as 3.0.4, and set symlinks up to determine
> the default. GLIBC was to be the first thing I compiled with gcc3 so I have
> compiled no other libraries and whatnot.
> After I rgrepped the glibc source, I found how that GCC_3.0 symbol/tag got in
> there. I don't understand why it is there though.
> Thanks for stirring my brains! :)
Well, now my brains will collapse
Look at the output of
$ objdump -p /lib/libc.so.6
The short answer is that the dynamic linker need extra info to be able
to perform is job and that this information is provided in a special
those are the Dynamic array tags, that is DT_NULL is there by default
and is a dummy section(not printed). And DT_NEEDED, DT_SONAME, DT_INIT
see figure 5-10
They are called processor-specific semantic,
and are undocumentented.
The section VERDEF has following information
13 0x00 0x0b792650 GCC_3.0
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