[cmake] Disable GNU Gold linker on Cortex A53

• Component: New Bugs
• Status: RESOLVED FIXED

[Csaba Osztrogonác]

https://bugs.webkit.org/show_bug.cgi?id=138840#c5

The problem is that -mfix-cortex-a53-835769 errata detection is placed
before the gold linker detection. It tries to detect if the default
system linker supports it and later uses gold linker for the real build.

I can't found any commit in trunk gold linker, so the easiest fix is to 
disable gold linker on Cortex A53 to be able to use the necessary workaround.

[Alberto Garcia]

Yeah, that looks like the best solution to me as well.

[Csaba Osztrogonác]

Created attachment 251941 [details]
Patch

WIP patch, I'm going to check it on real hardware.

[Michael Catanzaro]

OK... so CMAKE_DEPENDENT_OPTION is a thing....

There's a typo in the patch: workaroung -> workaround.

[Csaba Osztrogonác]

Created attachment 251961 [details]
Patch

I fixed the mentioned typo, added the necessary include and negated CXX_ACCEPTS_MFIX_CORTEX_A53_835769 in CMAKE_DEPENDENT_OPTION which was wrong in my previous patch. (tested on real hw)

[Alberto Garcia]

(In reply to comment #4)
> Created attachment 251961 [details]
> Patch
> 
> I fixed the mentioned typo, added the necessary include and negated
> CXX_ACCEPTS_MFIX_CORTEX_A53_835769 in CMAKE_DEPENDENT_OPTION which was wrong
> in my previous patch. (tested on real hw)

Looks good to me, thanks for testing it!

[Csaba Osztrogonác]

I asked the authors of the errata fix in BFD linker and they
said that only the BFD linker is supported and they aren't
planning to add this fix to the gold linker.

So this change is really the correct fix.

[Csaba Osztrogonác]

Comment on attachment 251961 [details]
Patch

Clearing flags on attachment: 251961

Committed r183741: <http://trac.webkit.org/changeset/183741>

[Csaba Osztrogonác]

All reviewed patches have been landed.  Closing bug.