Re: Binutils is broken by the linker change

[Alan Modra <amodra at bigpond dot net dot au>]

On Thu, Mar 18, 2004 at 02:51:42PM -0800, H. J. Lu wrote:
> Here is a patch. Basically, a weak definition is treated as strong if
> the other comes from a shared library.

Email lag, sorry.  I committed my patch, but I see you have a different
fix, one that reflects the way ld.so works.  ie. in the testcase you
sent to the list, the weak foo is the one that actually gets called.
The strong foo in a later dynamic lib _doesn't_ override.

Please, please, add this testcase to the ld testsuite!  With weak and
strong foo returning different values or somesuch so you can check
which one is called..

> @@ -887,6 +885,15 @@ _bfd_elf_merge_symbol (bfd *abfd,
>    oldweak = (h->root.type == bfd_link_hash_defweak
>  	     || h->root.type == bfd_link_hash_undefweak);
>  
> +  /* If a new weak definition comes from a regular file and the old
> +     symbol comes from a dynamic library, we treat the new one as
> +     strong.  Further, an old weak definition is treated as strong
> +     when the new symbol comes from a dynamic library.  */
> +  if (newdef && !newdyn && olddyn)
> +    newweak = FALSE;
> +  if (olddef && newdyn)
> +    oldweak = FALSE;
> +
>    /* It's OK to change the type if either the existing symbol or the
>       new symbol is weak.  A type change is also OK if the old symbol
>       is undefined and the new symbol is defined.  */

Is there a reason why you moved this code above the type/size change
code?  Also, I don't think there is any need to add newdef and olddef
to the tests.  That just confuses the meaning of newweak and oldweak.

  /* If a new weak symbol comes from a regular file and the old symbol
     comes from a dynamic library, we treat the new one as strong.
     Similarly, an old weak symbol from a regular file is treated as
     strong when the new symbol comes from a dynamic library.  Further,
     an old weak symbol from a dynamic library is treated as strong if
     the new symbol is from a dynamic library.  This reflects the way
     glibc's ld.so works.  */
  if (!newdyn && olddyn)
    newweak = FALSE;
  if (newdyn)
    oldweak = FALSE;

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre