Re: [PATCH] kconfig: detect LD implementation
On Wed, Mar 16, 2022 at 11:28:48AM +0100, Michal Orzel wrote: > 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 > > --- > > 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. I'm afraid I don't agree. We use head because we only want to match against the first line of the output, and then we use '^' to match at the beginning of such line. Without using head we would end up matching at the beginning of any line present in the output. Thanks, Roger.
Re: [PATCH] kconfig: detect LD implementation
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 > --- > 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 Cheers, Michal
[PATCH] kconfig: detect LD implementation
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 --- 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) -- 2.34.1
