Re: LLVM build warnings

[Maxime Villard <max%m00nbsd.net@localhost>]

Le 13/04/2020 à 08:12, Maxime Villard a écrit :
> Le 13/04/2020 à 00:39, Joerg Sonnenberger a écrit :
>> On Sat, Apr 11, 2020 at 01:05:07PM +0200, Maxime Villard wrote:
>>> When testing CFLAGS with LLVM, I often hit warnings like this one:
>>
>> OK, let's take a step back. What *exactly* are you trying to do?
> 
> Well, it's rather simple. Try to build aarch64 with PAC, you get:
> 
> 	--- libkern.o ---
> 	building standard kern library
> 	aarch64--netbsd-clang: error: argument unused during compilation: '-mbranch-protection=pac-ret' [-Werror,-Wunused-command-line-argument]
> 
> The Makefile is here:
> 
> 	https://nxr.netbsd.org/xref/src/sys/arch/aarch64/conf/Makefile.aarch64?r=1.19#46
> 
> I want to compile each kernel object with '-mbranch-protection=pac-ret'.
> 
> Same warning with BTI enabled. And I've basically had this warning
> many times on amd64 when testing new flags.
> 
> Thanks,
> Maxime

Now you also get the warning when building KASAN on LLVM.

So, would you have a better flag to suggest? Because if not, I will disable
the warning.

Thanks,
Maxime