[llvm-commits] patch: teach deadargelim to work on externally visible functions!

[Rafael Espindola]

> for -m64:
> -       movq    g at GOTPCREL(%rip), %rax
> +       leaq    g(%rip), %rax

This is very odd. Since a protected function can be used from another
library this would create the need to patch the text segment in the
dynamic linker.

Trying to put the resulting .o in a shared library fails when using gnu ld:

gcc -shared -o test.so test.c
/usr/bin/ld: /tmp/ccqwpSKK.o: relocation R_X86_64_32S against `g' can
not be used when making a shared object; recompile with -fPIC
/tmp/ccqwpSKK.o: could not read symbols: Bad value

My take is that protected is broken enough that we can implement a
best effort :-)

>
> BTW I also found this in gcc manpage:
> "Note that due to ISO C++  specification requirements, operator new and
> operator delete must
> always be of default visibility."
>
> Best regards,
> --Edwin
>


Cheers,
-- 
Rafael Ávila de Espíndola