All of lore.kernel.org
 help / color / mirror / Atom feed
From: Nathan Chancellor <nathan@kernel.org>
To: Masahiro Yamada <masahiroy@kernel.org>, linux-kbuild@vger.kernel.org
Cc: Albert Ou <aou@eecs.berkeley.edu>,
	Michal Marek <michal.lkml@markovi.net>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	clang-built-linux@googlegroups.com, linux-kernel@vger.kernel.org,
	linux-riscv@lists.infradead.org
Subject: Re: [PATCH] kbuild: check CONFIG_AS_IS_LLVM instead of LLVM_IAS
Date: Thu, 5 Aug 2021 11:46:10 -0700	[thread overview]
Message-ID: <59ce441e-8deb-39ff-700f-4e1c4e871177@kernel.org> (raw)
In-Reply-To: <20210805150102.131008-1-masahiroy@kernel.org>

On 8/5/2021 8:01 AM, Masahiro Yamada wrote:
> LLVM_IAS is the user interface to set the -(no-)integrated-as flag,
> and it should be used only for that purpose.
> 
> LLVM_IAS is checked in some places to determine the assembler type,
> but it is not precise.
> 
>   $ make CC=gcc LLVM_IAS=1
> 
> ... will use the GNU assembler since LLVM_IAS=1 is effective only when
> $(CC) is clang.
> 
> Of course, the combination of CC=gcc and LLVM_IAS=1 does not make
> sense, but the build system can be more robust against such insane
> input.
> 
> Commit ba64beb17493a ("kbuild: check the minimum assembler version in
> Kconfig") introduced CONFIG_AS_IS_GNU/LLVM, which is more precise
> because Kconfig checks the version string from the assembler in use.
> 
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
> 
>   Makefile            | 2 +-
>   arch/riscv/Makefile | 2 +-
>   2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index 4ab151060931..8b56c9692c3c 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -844,7 +844,7 @@ else
>   DEBUG_CFLAGS	+= -g
>   endif
>   
> -ifneq ($(LLVM_IAS),1)
> +ifndef CONFIG_AS_IS_LLVM
>   KBUILD_AFLAGS	+= -Wa,-gdwarf-2
>   endif
>   
> diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
> index bc74afdbf31e..dcfbd2a87d41 100644
> --- a/arch/riscv/Makefile
> +++ b/arch/riscv/Makefile
> @@ -41,7 +41,7 @@ endif
>   ifeq ($(CONFIG_LD_IS_LLD),y)
>   	KBUILD_CFLAGS += -mno-relax
>   	KBUILD_AFLAGS += -mno-relax
> -ifneq ($(LLVM_IAS),1)
> +ifndef CONFIG_AS_IS_LLVM
>   	KBUILD_CFLAGS += -Wa,-mno-relax
>   	KBUILD_AFLAGS += -Wa,-mno-relax
>   endif
> 

WARNING: multiple messages have this Message-ID (diff)
From: Nathan Chancellor <nathan@kernel.org>
To: Masahiro Yamada <masahiroy@kernel.org>, linux-kbuild@vger.kernel.org
Cc: Albert Ou <aou@eecs.berkeley.edu>,
	Michal Marek <michal.lkml@markovi.net>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	clang-built-linux@googlegroups.com, linux-kernel@vger.kernel.org,
	linux-riscv@lists.infradead.org
Subject: Re: [PATCH] kbuild: check CONFIG_AS_IS_LLVM instead of LLVM_IAS
Date: Thu, 5 Aug 2021 11:46:10 -0700	[thread overview]
Message-ID: <59ce441e-8deb-39ff-700f-4e1c4e871177@kernel.org> (raw)
In-Reply-To: <20210805150102.131008-1-masahiroy@kernel.org>

On 8/5/2021 8:01 AM, Masahiro Yamada wrote:
> LLVM_IAS is the user interface to set the -(no-)integrated-as flag,
> and it should be used only for that purpose.
> 
> LLVM_IAS is checked in some places to determine the assembler type,
> but it is not precise.
> 
>   $ make CC=gcc LLVM_IAS=1
> 
> ... will use the GNU assembler since LLVM_IAS=1 is effective only when
> $(CC) is clang.
> 
> Of course, the combination of CC=gcc and LLVM_IAS=1 does not make
> sense, but the build system can be more robust against such insane
> input.
> 
> Commit ba64beb17493a ("kbuild: check the minimum assembler version in
> Kconfig") introduced CONFIG_AS_IS_GNU/LLVM, which is more precise
> because Kconfig checks the version string from the assembler in use.
> 
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
> 
>   Makefile            | 2 +-
>   arch/riscv/Makefile | 2 +-
>   2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index 4ab151060931..8b56c9692c3c 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -844,7 +844,7 @@ else
>   DEBUG_CFLAGS	+= -g
>   endif
>   
> -ifneq ($(LLVM_IAS),1)
> +ifndef CONFIG_AS_IS_LLVM
>   KBUILD_AFLAGS	+= -Wa,-gdwarf-2
>   endif
>   
> diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
> index bc74afdbf31e..dcfbd2a87d41 100644
> --- a/arch/riscv/Makefile
> +++ b/arch/riscv/Makefile
> @@ -41,7 +41,7 @@ endif
>   ifeq ($(CONFIG_LD_IS_LLD),y)
>   	KBUILD_CFLAGS += -mno-relax
>   	KBUILD_AFLAGS += -mno-relax
> -ifneq ($(LLVM_IAS),1)
> +ifndef CONFIG_AS_IS_LLVM
>   	KBUILD_CFLAGS += -Wa,-mno-relax
>   	KBUILD_AFLAGS += -Wa,-mno-relax
>   endif
> 

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

  parent reply	other threads:[~2021-08-05 18:46 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-05 15:01 [PATCH] kbuild: check CONFIG_AS_IS_LLVM instead of LLVM_IAS Masahiro Yamada
2021-08-05 15:01 ` Masahiro Yamada
2021-08-05 18:22 ` Nick Desaulniers
2021-08-05 18:22   ` Nick Desaulniers
2021-08-05 18:46 ` Nathan Chancellor [this message]
2021-08-05 18:46   ` Nathan Chancellor
2021-08-10  0:05   ` Masahiro Yamada
2021-08-10  0:05     ` Masahiro Yamada

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=59ce441e-8deb-39ff-700f-4e1c4e871177@kernel.org \
    --to=nathan@kernel.org \
    --cc=aou@eecs.berkeley.edu \
    --cc=clang-built-linux@googlegroups.com \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=masahiroy@kernel.org \
    --cc=michal.lkml@markovi.net \
    --cc=ndesaulniers@google.com \
    --cc=palmer@dabbelt.com \
    --cc=paul.walmsley@sifive.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.