diff mbox series

[v2,1/7] kbuild: clear LDFLAGS in the top Makefile

Message ID 1521166725-24157-2-git-send-email-yamada.masahiro@socionext.com
State Superseded
Headers show
Series kbuild: various fix, clean-up, improvements of CONFIG_TRIM_UNUSED_KSYMS | expand

Commit Message

Masahiro Yamada March 16, 2018, 2:18 a.m. UTC 
Currently LDFLAGS is not cleared, so same flags are accumulated in
LDFLAGS when the top Makefile is recursively invoked.

I found unneeded rebuild for ARCH=arm64 when CONFIG_TRIM_UNUSED_KSYMS
is enabled.  If include/generated/autoksyms.h is updated, the top
Makefile is recursively invoked, then arch/arm64/Makefile adds one
more '-maarch64linux'.  Due to the command line change, modules are
rebuilt needlessly.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

---

Changes in v2: None

 Makefile | 1 +
 1 file changed, 1 insertion(+)

-- 
2.7.4

Comments

Nicolas Pitre March 16, 2018, 2:37 a.m. UTC | #1 
On Fri, 16 Mar 2018, Masahiro Yamada wrote:

> Currently LDFLAGS is not cleared, so same flags are accumulated in

> LDFLAGS when the top Makefile is recursively invoked.

> 

> I found unneeded rebuild for ARCH=arm64 when CONFIG_TRIM_UNUSED_KSYMS

> is enabled.  If include/generated/autoksyms.h is updated, the top

> Makefile is recursively invoked, then arch/arm64/Makefile adds one

> more '-maarch64linux'.  Due to the command line change, modules are

> rebuilt needlessly.

> 

> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>


Acked-by: Nicolas Pitre <nico@linaro.org>



> ---

> 

> Changes in v2: None

> 

>  Makefile | 1 +

>  1 file changed, 1 insertion(+)

> 

> diff --git a/Makefile b/Makefile

> index d9bb6dd6..ac8755d 100644

> --- a/Makefile

> +++ b/Makefile

> @@ -437,6 +437,7 @@ KBUILD_CFLAGS_KERNEL :=

>  KBUILD_AFLAGS_MODULE  := -DMODULE

>  KBUILD_CFLAGS_MODULE  := -DMODULE

>  KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds

> +LDFLAGS :=

>  GCC_PLUGINS_CFLAGS :=

>  

>  export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC

> -- 

> 2.7.4

> 

>
diff mbox series

Patch

diff --git a/Makefile b/Makefile
index d9bb6dd6..ac8755d 100644
--- a/Makefile
+++ b/Makefile
@@ -437,6 +437,7 @@  KBUILD_CFLAGS_KERNEL :=
 KBUILD_AFLAGS_MODULE  := -DMODULE
 KBUILD_CFLAGS_MODULE  := -DMODULE
 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
+LDFLAGS :=
 GCC_PLUGINS_CFLAGS :=
 
 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC