Re: A patch for default version and archive

["H . J . Lu" <hjl at valinux dot com>]

On Wed, Nov 08, 2000 at 01:38:06PM -0800, H . J . Lu wrote:
> On Wed, Nov 08, 2000 at 11:23:06AM -0800, H . J . Lu wrote:
> > When we have default version in an archive, we fail to resolve the
> > reference with only one `@':
> > 
> > # make
> > gcc  -O   -c -o test.o test.c
> > gcc  -O   -c -o foo.o foo.c
> > gcc  -o test1 test.o foo.o
> > ar rv libfoo.a foo.o
> > r - foo.o
> > gcc  -o test2 test.o libfoo.a
> > test.o: In function `main':
> > test.o(.text+0x7): undefined reference to `foo@GLIBC_2.0'
> > collect2: ld returned 1 exit status
> > 
> > I am enclosing a patch and a testcae here.
> > 
> > 
> > -- 
> > H.J. Lu (hjl@gnu.org)
> > ---
> > 2000-11-08  H.J. Lu  <hjl@gnu.org>
> > 
> > 	* elflink.h (elf_link_add_archive_symbols): For the default
> > 	version, check references with only one `@' first.
> > 
> 
> My last patch has a typo. It should be strcpy, not strcat.
> 

Just clarify my patch. The default versioned symbol, foo@@verion1,
will resolve references to foo and foo@verion1. That is how symbol
versioning works. When you do

# gcc ... libfoo.a ...

the linker won't pull in a .o file from libfoo.a unless it sees
references to symbols defined in libfoo.a before reading libfoo.a.
There is a bug in elf_link_add_archive_symbols. When the linker sees
a definition like foo@@verion1, it only checks references to foo. It
misses foo@verion1. That is why

# gcc -o test1 test.o foo.o

works, but

# gcc -o test1 test.o libfoo.a

doesn't. My patch adds the check for references to foo@verion1. Let
me know if there are questions.

Thanks.


H.J.