Re: [PATCH] kconfig: detect LD implementation

[Michal Orzel <michal.orzel@xxxxxxx>]

Hi Roger,

On 14.03.2022 11:55, Roger Pau Monne wrote:
> Detect GNU and LLVM ld implementations. This is required for further
> patches that will introduce diverging behaviour depending on the
> linker implementation in use.
> 
> Note that LLVM ld returns "compatible with GNU linkers" as part of the
> version string, so be on the safe side and use '^' to only match at
> the start of the line in case LLVM ever decides to change the text to
> use "compatible with GNU ld" instead.
> 
> Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> ---
>  xen/Kconfig | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/xen/Kconfig b/xen/Kconfig
> index d134397a0b..e8d5e70d46 100644
> --- a/xen/Kconfig
> +++ b/xen/Kconfig
> @@ -23,6 +23,12 @@ config CLANG_VERSION
>       int
>       default $(shell,$(BASEDIR)/scripts/clang-version.sh $(CC))
>  
> +config LD_IS_GNU
> +     def_bool $(success,$(LD) --version | head -n 1 | grep -q "^GNU ld")
> +> +config LD_IS_LLVM
> +     def_bool $(success,$(LD) --version | head -n 1 | grep -q "^LLD")
> +
>  # -fvisibility=hidden reduces -fpic cost, if it's available
>  config CC_HAS_VISIBILITY_ATTRIBUTE
>       def_bool $(cc-option,-fvisibility=hidden)

NIT: You do not really need to use head especiialy if grep for the beginning of 
a line.
With or without this:
Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>

Cheers,
Michal