* [PATCH] kbuild: drop support for cc-ldoption
@ 2019-04-23 21:27 Nick Desaulniers
2019-04-24 3:51 ` Masahiro Yamada
2019-05-20 15:08 ` Masahiro Yamada
0 siblings, 2 replies; 3+ messages in thread
From: Nick Desaulniers @ 2019-04-23 21:27 UTC (permalink / raw)
To: yamada.masahiro, michal.lkml, corbet
Cc: Nick Desaulniers, clang-built-linux, linux-kbuild, linux-doc,
linux-kernel
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@googlegroups.com
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
This should probably wait until all of the call sites have been cleaned
up. Masahiro sent them for arm and arm64, while I sent cleanups for all
the rest.
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] kbuild: drop support for cc-ldoption
2019-04-23 21:27 [PATCH] kbuild: drop support for cc-ldoption Nick Desaulniers
@ 2019-04-24 3:51 ` Masahiro Yamada
2019-05-20 15:08 ` Masahiro Yamada
1 sibling, 0 replies; 3+ messages in thread
From: Masahiro Yamada @ 2019-04-24 3:51 UTC (permalink / raw)
To: Nick Desaulniers
Cc: Michal Marek, Jonathan Corbet, clang-built-linux,
Linux Kbuild mailing list, open list:DOCUMENTATION,
Linux Kernel Mailing List
On Wed, Apr 24, 2019 at 6:27 AM Nick Desaulniers
<ndesaulniers@google.com> 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@googlegroups.com
> Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
> 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
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] kbuild: drop support for cc-ldoption
2019-04-23 21:27 [PATCH] kbuild: drop support for cc-ldoption Nick Desaulniers
2019-04-24 3:51 ` Masahiro Yamada
@ 2019-05-20 15:08 ` Masahiro Yamada
1 sibling, 0 replies; 3+ messages in thread
From: Masahiro Yamada @ 2019-05-20 15:08 UTC (permalink / raw)
To: Nick Desaulniers
Cc: Michal Marek, Jonathan Corbet, clang-built-linux,
Linux Kbuild mailing list, open list:DOCUMENTATION,
Linux Kernel Mailing List
On Wed, Apr 24, 2019 at 6:27 AM Nick Desaulniers
<ndesaulniers@google.com> 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@googlegroups.com
> Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
Applied to linux-kbuild. Thanks.
> This should probably wait until all of the call sites have been cleaned
> up. Masahiro sent them for arm and arm64, while I sent cleanups for all
> the rest.
>
>
> 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
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-04-24 3:51 ` Masahiro Yamada
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