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Subject: Re: [clang] stack protector and f1f029c7bf
To: Nick Desaulniers <ndesaulniers@google.com>
Cc: Alistair Strachan <astrachan@google.com>,
        Manoj Gupta <manojgupta@google.com>,
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From: "H. Peter Anvin" <hpa@zytor.com>
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Date: Thu, 24 May 2018 14:49:32 -0700
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On 05/24/18 14:12, Nick Desaulniers wrote:
> 
> Looks like those builtins got added to GCC around the 4.9 timeframe:
> https://godbolt.org/g/9VS2E9
> 
> Problematically, it seems that GCC does not have __has_builtin to do
> feature detection:
> https://clang.llvm.org/docs/LanguageExtensions.html#feature-checking-macros
> https://godbolt.org/g/oku8ux
> 

We have support in the kernel build system for doing that, though.

I just added a concurring opinion to the gcc bug report:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66970