2019-05-14 22:44:22

by Nathan Chancellor

Subject: [PATCH] objtool: Allow AR to be overridden with HOSTAR

Currently, this Makefile hardcodes GNU ar, meaning that if it is not
available, there is no way to supply a different one and the build will
fail.

$ make AR=llvm-ar CC=clang LD=ld.lld HOSTAR=llvm-ar HOSTCC=clang \
HOSTLD=ld.lld HOSTLDFLAGS=-fuse-ld=lld defconfig modules_prepare
...
AR /out/tools/objtool/libsubcmd.a
/bin/sh: 1: ar: not found
...

Follow the logic of HOST{CC,LD} and allow the user to specify a
different ar tool via HOSTAR (which is used elsewhere in other
tools/ Makefiles).

Link: https://github.com/ClangBuiltLinux/linux/issues/481
Signed-off-by: Nathan Chancellor <[email protected]>
---
tools/objtool/Makefile | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index 53f8be0f4a1f..88158239622b 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -7,11 +7,12 @@ ARCH := x86
endif

# always use the host compiler
+HOSTAR ?= ar
HOSTCC ?= gcc
HOSTLD ?= ld
+AR = $(HOSTAR)
CC = $(HOSTCC)
LD = $(HOSTLD)
-AR = ar

ifeq ($(srctree),)
srctree := $(patsubst %/,%,$(dir $(CURDIR)))
--
2.22.0.rc0

2019-05-14 22:49:28

by Nick Desaulniers

Subject: Re: [PATCH] objtool: Allow AR to be overridden with HOSTAR

.On Tue, May 14, 2019 at 3:41 PM Nathan Chancellor
<[email protected]> wrote:
>
> Currently, this Makefile hardcodes GNU ar, meaning that if it is not
> available, there is no way to supply a different one and the build will
> fail.
>
> $ make AR=llvm-ar CC=clang LD=ld.lld HOSTAR=llvm-ar HOSTCC=clang \
> HOSTLD=ld.lld HOSTLDFLAGS=-fuse-ld=lld defconfig modules_prepare
> ...
> AR /out/tools/objtool/libsubcmd.a
> /bin/sh: 1: ar: not found
> ...
>
> Follow the logic of HOST{CC,LD} and allow the user to specify a
> different ar tool via HOSTAR (which is used elsewhere in other
> tools/ Makefiles).
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/481
> Signed-off-by: Nathan Chancellor <[email protected]>
> ---
> tools/objtool/Makefile | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
> index 53f8be0f4a1f..88158239622b 100644
> --- a/tools/objtool/Makefile
> +++ b/tools/objtool/Makefile
> @@ -7,11 +7,12 @@ ARCH := x86
> endif
>
> # always use the host compiler
> +HOSTAR ?= ar
> HOSTCC ?= gcc
> HOSTLD ?= ld
> +AR = $(HOSTAR)
> CC = $(HOSTCC)
> LD = $(HOSTLD)
> -AR = ar

+ Kbuild
Seems to match what's going on in tools/perf/Makefile.perf and
tools/build/Makefile. Thanks for the patch!
Reviewed-by: Nick Desaulniers <[email protected]>

--
Thanks,
~Nick Desaulniers

2019-05-15 12:37:04

by Mukesh Ojha

Subject: Re: [PATCH] objtool: Allow AR to be overridden with HOSTAR

On 5/15/2019 4:10 AM, Nathan Chancellor wrote:
> Currently, this Makefile hardcodes GNU ar, meaning that if it is not
> available, there is no way to supply a different one and the build will
> fail.
>
> $ make AR=llvm-ar CC=clang LD=ld.lld HOSTAR=llvm-ar HOSTCC=clang \
> HOSTLD=ld.lld HOSTLDFLAGS=-fuse-ld=lld defconfig modules_prepare
> ...
> AR /out/tools/objtool/libsubcmd.a
> /bin/sh: 1: ar: not found
> ...
>
> Follow the logic of HOST{CC,LD} and allow the user to specify a
> different ar tool via HOSTAR (which is used elsewhere in other
> tools/ Makefiles).
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/481
> Signed-off-by: Nathan Chancellor <[email protected]>


Nice catch.
Reviewed-by: Mukesh Ojha <[email protected]>

Cheers,
-Mukesh

> ---
> tools/objtool/Makefile | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
> index 53f8be0f4a1f..88158239622b 100644
> --- a/tools/objtool/Makefile
> +++ b/tools/objtool/Makefile
> @@ -7,11 +7,12 @@ ARCH := x86
> endif
>
> # always use the host compiler
> +HOSTAR ?= ar
> HOSTCC ?= gcc
> HOSTLD ?= ld
> +AR = $(HOSTAR)
> CC = $(HOSTCC)
> LD = $(HOSTLD)
> -AR = ar
>
> ifeq ($(srctree),)
> srctree := $(patsubst %/,%,$(dir $(CURDIR)))

2019-05-15 15:20:35

by Josh Poimboeuf

Subject: Re: [PATCH] objtool: Allow AR to be overridden with HOSTAR

On Tue, May 14, 2019 at 03:40:47PM -0700, Nathan Chancellor wrote:
> Currently, this Makefile hardcodes GNU ar, meaning that if it is not
> available, there is no way to supply a different one and the build will
> fail.
>
> $ make AR=llvm-ar CC=clang LD=ld.lld HOSTAR=llvm-ar HOSTCC=clang \
> HOSTLD=ld.lld HOSTLDFLAGS=-fuse-ld=lld defconfig modules_prepare
> ...
> AR /out/tools/objtool/libsubcmd.a
> /bin/sh: 1: ar: not found
> ...
>
> Follow the logic of HOST{CC,LD} and allow the user to specify a
> different ar tool via HOSTAR (which is used elsewhere in other
> tools/ Makefiles).
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/481
> Signed-off-by: Nathan Chancellor <[email protected]>

Thanks Nathan. I'll send it along to the tip tree.

--
Josh