diff mbox series

[2/4] Makefile: clang: choose GCC_TOOLCHAIN_DIR not on LD

Message ID 20190207220155.81351-2-ndesaulniers@google.com
State Superseded
Headers show
Series [1/4] init/Kconfig: add config support for detecting linker | expand

Commit Message

Nick Desaulniers Feb. 7, 2019, 10:01 p.m. UTC
This causes an issue when trying to build with `make LD=ld.lld` if
ld.lld and the rest of your cross tools aren't in the same directory
(ex. /usr/local/bin) (as is the case for Android's build system), as the
GCC_TOOLCHAIN_DIR then gets set based on `which $(LD)` which will point
where LLVM tools are, not GCC/binutils tools are located.

Instead, select the GCC_TOOLCHAIN_DIR based on another tool provided by
binutils for which LLVM does not provide a substitute for, such as
elfedit.

Fixes commit 785f11aa595b ("kbuild: Add better clang cross build support")

Link: https://github.com/ClangBuiltLinux/linux/issues/341
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.20.1.791.gb4d0f1c61a-goog

Comments

Nathan Chancellor Feb. 8, 2019, 5:45 a.m. UTC | #1
On Thu, Feb 07, 2019 at 02:01:50PM -0800, ndesaulniers@google.com wrote:
> This causes an issue when trying to build with `make LD=ld.lld` if

> ld.lld and the rest of your cross tools aren't in the same directory

> (ex. /usr/local/bin) (as is the case for Android's build system), as the

> GCC_TOOLCHAIN_DIR then gets set based on `which $(LD)` which will point

> where LLVM tools are, not GCC/binutils tools are located.

> 

> Instead, select the GCC_TOOLCHAIN_DIR based on another tool provided by

> binutils for which LLVM does not provide a substitute for, such as

> elfedit.

> 

> Fixes commit 785f11aa595b ("kbuild: Add better clang cross build support")

> 

> Link: https://github.com/ClangBuiltLinux/linux/issues/341

> Suggested-by: Nathan Chancellor <natechancellor@gmail.com>

> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>


Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>

Tested-by: Nathan Chancellor <natechancellor@gmail.com>


> ---

>  Makefile | 2 +-

>  1 file changed, 1 insertion(+), 1 deletion(-)

> 

> diff --git a/Makefile b/Makefile

> index 3142e67d03f1..0eae4277206e 100644

> --- a/Makefile

> +++ b/Makefile

> @@ -492,7 +492,7 @@ endif

>  ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)

>  ifneq ($(CROSS_COMPILE),)

>  CLANG_FLAGS	:= --target=$(notdir $(CROSS_COMPILE:%-=%))

> -GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD)))

> +GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))

>  CLANG_FLAGS	+= --prefix=$(GCC_TOOLCHAIN_DIR)

>  GCC_TOOLCHAIN	:= $(realpath $(GCC_TOOLCHAIN_DIR)/..)

>  endif

> -- 

> 2.20.1.791.gb4d0f1c61a-goog

>
diff mbox series

Patch

diff --git a/Makefile b/Makefile
index 3142e67d03f1..0eae4277206e 100644
--- a/Makefile
+++ b/Makefile
@@ -492,7 +492,7 @@  endif
 ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
 ifneq ($(CROSS_COMPILE),)
 CLANG_FLAGS	:= --target=$(notdir $(CROSS_COMPILE:%-=%))
-GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD)))
+GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
 CLANG_FLAGS	+= --prefix=$(GCC_TOOLCHAIN_DIR)
 GCC_TOOLCHAIN	:= $(realpath $(GCC_TOOLCHAIN_DIR)/..)
 endif