| Message ID | 1519361813-8553-2-git-send-email-yamada.masahiro@socionext.com |
|---|---|
| State | Accepted |
| Commit | 0294e6f4a0006856e1f36b8cd8fa088d9e499e98 |
| Headers | show |
| Series | [1/2] kbuild: test --build-id linker flag by ld-option instead of cc-ldoption | expand |
Nice! Now we don't need to invoke $CC to find out info about linker support. Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> On Thu, Feb 22, 2018 at 8:57 PM Masahiro Yamada < yamada.masahiro@socionext.com> wrote: > Currently, linker options are tested by the coordination of $(CC) and > $(LD) because LD needs some object to link. > As commit 86a9df597cdd ("kbuild: fix linker feature test macros when > cross compiling with Clang") addressed, we need to make sure $(CC) > and $(LD) agree the underlying architecture of the passed object. > This could be a bit complex when we combine tools from different groups. > For example, we can use clang for $(CC), but we still need to rely on > GCC toolchain for $(LD). > So, I was searching a way for standalone testing of linker options. > A trick I found is to use '-v'. This prints the version string, but > also tests if the given option is recognized. > If a given option is supported, > $ aarch64-linux-gnu-ld -v --fix-cortex-a53-843419 > GNU ld (Linaro_Binutils-2017.11) 2.28.2.20170706 > $ echo $? > 0 > If unsupported, > $ aarch64-linux-gnu-ld -v --fix-cortex-a53-843419 > GNU ld (crosstool-NG linaro-1.13.1-4.7-2013.04-20130415 - Linaro GCC > 2013.04) 2.23.1 > aarch64-linux-gnu-ld: unrecognized option '--fix-cortex-a53-843419' > aarch64-linux-gnu-ld: use the --help option for usage information > $ echo $? > 1 > Gold works likewise. > $ aarch64-linux-gnu-ld.gold -v --fix-cortex-a53-843419 > GNU gold (Linaro_Binutils-2017.11 2.28.2.20170706) 1.14 > masahiro@pug:~/ref/linux$ echo $? > 0 > $ aarch64-linux-gnu-ld.gold -v --fix-cortex-a53-999999 > GNU gold (Linaro_Binutils-2017.11 2.28.2.20170706) 1.14 > aarch64-linux-gnu-ld.gold: --fix-cortex-a53-999999: unknown option > aarch64-linux-gnu-ld.gold: use the --help option for usage information > $ echo $? > 1 > LLD too. > $ ld.lld -v --gc-sections > LLD 7.0.0 (http://llvm.org/git/lld.git > 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) > $ echo $? > 0 > $ ld.lld -v --fix-cortex-a53-843419 > LLD 7.0.0 (http://llvm.org/git/lld.git > 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) > $ echo $? > 0 > $ ld.lld -v --fix-cortex-a53-999999 > ld.lld: error: unknown argument: --fix-cortex-a53-999999 > LLD 7.0.0 (http://llvm.org/git/lld.git > 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) > $ echo $? > 1 > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> > --- > scripts/Kbuild.include | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include > index 34cbd81..f9c2f07 100644 > --- a/scripts/Kbuild.include > +++ b/scripts/Kbuild.include > @@ -237,9 +237,7 @@ cc-ldoption = $(call try-run-cached,\ > # ld-option > # Usage: LDFLAGS += $(call ld-option, -X) > -ld-option = $(call try-run-cached,\ > - $(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -x c /dev/null -c -o > "$$TMPO"; \ > - $(LD) $(LDFLAGS) $(1) "$$TMPO" -o "$$TMP",$(1),$(2)) > +ld-option = $(call try-run-cached, $(LD) $(LDFLAGS) $(1) -v,$(1),$(2)) > # ar-option > # Usage: KBUILD_ARFLAGS := $(call ar-option,D) > -- > 2.7.4 -- Thanks, ~Nick Desaulniers
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 34cbd81..f9c2f07 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -237,9 +237,7 @@ cc-ldoption = $(call try-run-cached,\ # ld-option # Usage: LDFLAGS += $(call ld-option, -X) -ld-option = $(call try-run-cached,\ - $(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -x c /dev/null -c -o "$$TMPO"; \ - $(LD) $(LDFLAGS) $(1) "$$TMPO" -o "$$TMP",$(1),$(2)) +ld-option = $(call try-run-cached, $(LD) $(LDFLAGS) $(1) -v,$(1),$(2)) # ar-option # Usage: KBUILD_ARFLAGS := $(call ar-option,D)
Currently, linker options are tested by the coordination of $(CC) and $(LD) because LD needs some object to link. As commit 86a9df597cdd ("kbuild: fix linker feature test macros when cross compiling with Clang") addressed, we need to make sure $(CC) and $(LD) agree the underlying architecture of the passed object. This could be a bit complex when we combine tools from different groups. For example, we can use clang for $(CC), but we still need to rely on GCC toolchain for $(LD). So, I was searching a way for standalone testing of linker options. A trick I found is to use '-v'. This prints the version string, but also tests if the given option is recognized. If a given option is supported, $ aarch64-linux-gnu-ld -v --fix-cortex-a53-843419 GNU ld (Linaro_Binutils-2017.11) 2.28.2.20170706 $ echo $? 0 If unsupported, $ aarch64-linux-gnu-ld -v --fix-cortex-a53-843419 GNU ld (crosstool-NG linaro-1.13.1-4.7-2013.04-20130415 - Linaro GCC 2013.04) 2.23.1 aarch64-linux-gnu-ld: unrecognized option '--fix-cortex-a53-843419' aarch64-linux-gnu-ld: use the --help option for usage information $ echo $? 1 Gold works likewise. $ aarch64-linux-gnu-ld.gold -v --fix-cortex-a53-843419 GNU gold (Linaro_Binutils-2017.11 2.28.2.20170706) 1.14 masahiro@pug:~/ref/linux$ echo $? 0 $ aarch64-linux-gnu-ld.gold -v --fix-cortex-a53-999999 GNU gold (Linaro_Binutils-2017.11 2.28.2.20170706) 1.14 aarch64-linux-gnu-ld.gold: --fix-cortex-a53-999999: unknown option aarch64-linux-gnu-ld.gold: use the --help option for usage information $ echo $? 1 LLD too. $ ld.lld -v --gc-sections LLD 7.0.0 (http://llvm.org/git/lld.git 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) $ echo $? 0 $ ld.lld -v --fix-cortex-a53-843419 LLD 7.0.0 (http://llvm.org/git/lld.git 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) $ echo $? 0 $ ld.lld -v --fix-cortex-a53-999999 ld.lld: error: unknown argument: --fix-cortex-a53-999999 LLD 7.0.0 (http://llvm.org/git/lld.git 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) $ echo $? 1 Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> --- scripts/Kbuild.include | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) -- 2.7.4