Re: [PATCH v4 0/7] BaseTools: add support for GCC5 in LTO mode

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 1 August 2016 at 04:26, Gao, Liming <liming.gao@intel.com> wrote:
> Ard:
>  My GNU ld (GNU Binutils for Ubuntu) 2.24. Which version you use?
>
> 1. #pragma GCC visibility push (hidden) , GCC5 with GCC49 tool chain pass. GCC5 with GCC5 tool chain failure. Here is failure message.
> GenFw: Elf64Convert.c:424: ScanSections64: Assertion `((BOOLEAN)(0==1))' failed.
> GenFw: ERROR 3000: Invalid
>   Did not find any '.text' section.
> Aborted (core dumped)
>
> 2. #pragma GCC visibility push (protected), GCC5 with GCC49 tool chain failure, GCC5 with GCC5 tool chain pass. Failure message is below.
>

Thanks for checking. The problem with GCC5 is that the fact that
'_ModuleEntryPoint' is also hidden, which confuses the LTO code and
makes it eliminate all input objects. I think this is a bug in LTO,
since the entry point is passed explicitly to the linker using the -e
option. But we still need to work around it.

Since the current issue (#2) is a problem with GCC49, I will propose a
separate patch to fix it by changing the 'protected' to 'hidden'. I
will then add a patch to my GCC5 series as well to work around the LTO
problem.

Thanks,
Ard.