On Wed, Apr 24, 2019 at 6:27 AM Nick Desaulniers
<ndesaulniers@xxxxxxxxxx> wrote:
>
> If you want to see if your linker supports a certain flag, then ask the
> linker directly with ld-option (not the compiler with cc-ldoption).
> Checking for linker flag support is an antipattern that complicates the
> usage of various linkers other than bfd via -fuse-ld={bfd|gold|lld}.
>
> Cc: clang-built-linux@xxxxxxxxxxxxxxxx
> Suggested-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> ---
> This should probably wait until all of the call sites have been cleaned
> up.
Indeed.
Please remind me if I forget to apply this.
> Masahiro sent them for arm and arm64, while I sent cleanups for all
> the rest.
Thanks. I did not even notice cc-ldoption were checking
quite old flags.
>
>
> Documentation/kbuild/makefiles.txt | 14 --------------
> scripts/Kbuild.include | 5 -----
> 2 files changed, 19 deletions(-)
>
> diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
> index 03c065855eaf..d65ad5746f94 100644
> --- a/Documentation/kbuild/makefiles.txt
> +++ b/Documentation/kbuild/makefiles.txt
> @@ -437,20 +437,6 @@ more details, with real examples.
> The second argument is optional, and if supplied will be used
> if first argument is not supported.
>
> - cc-ldoption
> - cc-ldoption is used to check if $(CC) when used to link object files
> - supports the given option. An optional second option may be
> - specified if first option are not supported.
> -
> - Example:
> - #arch/x86/kernel/Makefile
> - vsyscall-flags += $(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
> -
> - In the above example, vsyscall-flags will be assigned the option
> - -Wl$(comma)--hash-style=sysv if it is supported by $(CC).
> - The second argument is optional, and if supplied will be used
> - if first argument is not supported.
> -
> as-instr
> as-instr checks if the assembler reports a specific instruction
> and then outputs either option1 or option2
> diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
> index 7484b9d8272f..fbfb37d1bcc8 100644
> --- a/scripts/Kbuild.include
> +++ b/scripts/Kbuild.include
> @@ -138,11 +138,6 @@ cc-disable-warning = $(call try-run,\
> # Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
> cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4))
>
> -# cc-ldoption
> -# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
> -cc-ldoption = $(call try-run,\
> - $(CC) $(1) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
> -
> # ld-option
> # Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
> ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
> --
> 2.21.0.593.g511ec345e18-goog
>
--
Best Regards
Masahiro Yamada
