[vxworks] PLT to weak symbol

Nathan Sidwell nathan@codesourcery.com
Wed Apr 11 09:56:00 GMT 2007


this patch fixes a problem that vxworks rtp has with weak symbols.  Consider:

app.c
	void Weak (void);
	void (*const ptr) (void) = &Weak;

lib.c
	void __attribute__((weak)) Weak (void) {}

This is what you get with a C++ class that has no key virtual function.  Weak is 
an inline virtual function.

The problem vxworks has is that .rodata (where 'ptr' resides) is relocated by 
the kernel loader, and that doesn't know anything about 'Weak'.  It blithely 
*ignores* the relocation we emit, and we end up with a broken image.

The rtp dynamic loader is responsible for filling in relocs to Weak, but it 
doesn't relocate .rodata and the like.

We already have special code to deal with the non-weak case here, and change the 
reloc for ptr's initializer to refer to .plt, which the kernel loader does know 
about.  This patch makes it do the same thing for weak definitions too.

ok?

nathan
-- 
Nathan Sidwell    ::   http://www.codesourcery.com   ::         CodeSourcery
nathan@codesourcery.com    ::     http://www.planetfall.pwp.blueyonder.co.uk

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