diff mbox series

scripts/Makefile.clang: set --target for host based on make -v

Message ID 20220617203948.3714905-1-ndesaulniers@google.com (mailing list archive)
State New, archived
Headers show
Series scripts/Makefile.clang: set --target for host based on make -v | expand

Commit Message

Nick Desaulniers June 17, 2022, 8:39 p.m. UTC 
We're working on providing statically linked images of clang to host on
kernel.org. We're building them in Alpine Linux based Docker containers,
which are MUSL based systems.

In order to keep bootstrapping simpler, I'd like for them to have an
implicit default --target of x86_64-alpine-linux-musl (set via LLVM's
cmake variable LLVM_DEFAULT_TARGET_TRIPLE).

Similarly, if one were to use a different build of clang meant for a
glibc or bionic based system on a MUSL based host, we'd prefer to use
the correct MUSL based triple for target hosts.

Borrowed from the Zen of Python: Explicit is better than implicit. Let's
be explicit about the target triple for HOSTCC when building with
HOSTCC=clang or LLVM=1.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
 Makefile               |  3 +--
 scripts/Makefile.clang | 10 ++++++++++
 2 files changed, 11 insertions(+), 2 deletions(-)


base-commit: 79fe0f863f920c5fcf9dea61676742f813f0b7a6

Comments

Nathan Chancellor June 17, 2022, 11:20 p.m. UTC | #1 
On Fri, Jun 17, 2022 at 01:39:48PM -0700, Nick Desaulniers wrote:
> We're working on providing statically linked images of clang to host on
> kernel.org. We're building them in Alpine Linux based Docker containers,
> which are MUSL based systems.
> 
> In order to keep bootstrapping simpler, I'd like for them to have an
> implicit default --target of x86_64-alpine-linux-musl (set via LLVM's
> cmake variable LLVM_DEFAULT_TARGET_TRIPLE).
> 
> Similarly, if one were to use a different build of clang meant for a
> glibc or bionic based system on a MUSL based host, we'd prefer to use
> the correct MUSL based triple for target hosts.
> 
> Borrowed from the Zen of Python: Explicit is better than implicit. Let's
> be explicit about the target triple for HOSTCC when building with
> HOSTCC=clang or LLVM=1.
> 
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

I have tested this with a few different distributions on both aarch64
and x86_64:

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

One small comment below.

> ---
>  Makefile               |  3 +--
>  scripts/Makefile.clang | 10 ++++++++++
>  2 files changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index 1a6678d817bd..87712d9b043c 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -600,10 +600,9 @@ endif
>  # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
>  # and from include/config/auto.conf.cmd to detect the compiler upgrade.
>  CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
> +HOSTCC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(HOSTCC) --version 2>/dev/null | head -n 1))
>  
> -ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
>  include $(srctree)/scripts/Makefile.clang
> -endif
>  
>  # Include this also for config targets because some architectures need
>  # cc-cross-prefix to determine CROSS_COMPILE.
> diff --git a/scripts/Makefile.clang b/scripts/Makefile.clang
> index 87285b76adb2..a4505cd62d7b 100644
> --- a/scripts/Makefile.clang
> +++ b/scripts/Makefile.clang
> @@ -1,3 +1,4 @@
> +ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
>  # Individual arch/{arch}/Makefiles should use -EL/-EB to set intended
>  # endianness and -m32/-m64 to set word size based on Kconfigs instead of
>  # relying on the target triple.
> @@ -39,3 +40,12 @@ CLANG_FLAGS	+= -Werror=ignored-optimization-argument
>  KBUILD_CFLAGS	+= $(CLANG_FLAGS)
>  KBUILD_AFLAGS	+= $(CLANG_FLAGS)
>  export CLANG_FLAGS
> +endif
> +
> +# If HOSTCC is clang, set the host target triple explicitly; do not rely on
> +# implicit defaults.
> +ifneq ($(findstring clang,$(HOSTCC_VERSION_TEXT)),)
> +HOST_TRIPLE		:= --target=$(shell make --version | head -n2 | tail -n1 | cut -d ' ' -f 3)

Should we use $(MAKE) instead of make here? I guess the only case where
it would matter is if someone was calling make via an explicit path and
did not have it available in their PATH so maybe it is not worth
worrying about.

> +KBUILD_HOSTCFLAGS	+= $(HOST_TRIPLE)
> +KBUILD_HOSTLDFLAGS	+= $(HOST_TRIPLE)
> +endif
> 
> base-commit: 79fe0f863f920c5fcf9dea61676742f813f0b7a6
> -- 
> 2.36.1.476.g0c4daa206d-goog
> 
>
Nick Desaulniers June 17, 2022, 11:26 p.m. UTC | #2 
On Fri, Jun 17, 2022 at 4:21 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> On Fri, Jun 17, 2022 at 01:39:48PM -0700, Nick Desaulniers wrote:
> > We're working on providing statically linked images of clang to host on
> > kernel.org. We're building them in Alpine Linux based Docker containers,
> > which are MUSL based systems.
> >
> > In order to keep bootstrapping simpler, I'd like for them to have an
> > implicit default --target of x86_64-alpine-linux-musl (set via LLVM's
> > cmake variable LLVM_DEFAULT_TARGET_TRIPLE).
> >
> > Similarly, if one were to use a different build of clang meant for a
> > glibc or bionic based system on a MUSL based host, we'd prefer to use
> > the correct MUSL based triple for target hosts.
> >
> > Borrowed from the Zen of Python: Explicit is better than implicit. Let's
> > be explicit about the target triple for HOSTCC when building with
> > HOSTCC=clang or LLVM=1.
> >
> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
>
> I have tested this with a few different distributions on both aarch64
> and x86_64:
>
> Reviewed-by: Nathan Chancellor <nathan@kernel.org>
> Tested-by: Nathan Chancellor <nathan@kernel.org>
>
> One small comment below.
>
> > ---
> >  Makefile               |  3 +--
> >  scripts/Makefile.clang | 10 ++++++++++
> >  2 files changed, 11 insertions(+), 2 deletions(-)
> >
> > diff --git a/Makefile b/Makefile
> > index 1a6678d817bd..87712d9b043c 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -600,10 +600,9 @@ endif
> >  # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
> >  # and from include/config/auto.conf.cmd to detect the compiler upgrade.
> >  CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
> > +HOSTCC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(HOSTCC) --version 2>/dev/null | head -n 1))
> >
> > -ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
> >  include $(srctree)/scripts/Makefile.clang
> > -endif
> >
> >  # Include this also for config targets because some architectures need
> >  # cc-cross-prefix to determine CROSS_COMPILE.
> > diff --git a/scripts/Makefile.clang b/scripts/Makefile.clang
> > index 87285b76adb2..a4505cd62d7b 100644
> > --- a/scripts/Makefile.clang
> > +++ b/scripts/Makefile.clang
> > @@ -1,3 +1,4 @@
> > +ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
> >  # Individual arch/{arch}/Makefiles should use -EL/-EB to set intended
> >  # endianness and -m32/-m64 to set word size based on Kconfigs instead of
> >  # relying on the target triple.
> > @@ -39,3 +40,12 @@ CLANG_FLAGS        += -Werror=ignored-optimization-argument
> >  KBUILD_CFLAGS        += $(CLANG_FLAGS)
> >  KBUILD_AFLAGS        += $(CLANG_FLAGS)
> >  export CLANG_FLAGS
> > +endif
> > +
> > +# If HOSTCC is clang, set the host target triple explicitly; do not rely on
> > +# implicit defaults.
> > +ifneq ($(findstring clang,$(HOSTCC_VERSION_TEXT)),)
> > +HOST_TRIPLE          := --target=$(shell make --version | head -n2 | tail -n1 | cut -d ' ' -f 3)
>
> Should we use $(MAKE) instead of make here? I guess the only case where

oh! yeah, good call. I think so.  Will wait until next Tuesday
(Juneteenth holiday in the US on Monday) to send a v2. Thanks for
taking a look!

> it would matter is if someone was calling make via an explicit path and
> did not have it available in their PATH so maybe it is not worth
> worrying about.
>
> > +KBUILD_HOSTCFLAGS    += $(HOST_TRIPLE)
> > +KBUILD_HOSTLDFLAGS   += $(HOST_TRIPLE)
> > +endif
> >
> > base-commit: 79fe0f863f920c5fcf9dea61676742f813f0b7a6
> > --
> > 2.36.1.476.g0c4daa206d-goog
> >
> >
Masahiro Yamada June 19, 2022, 9:19 a.m. UTC | #3 
On Sat, Jun 18, 2022 at 8:26 AM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> On Fri, Jun 17, 2022 at 4:21 PM Nathan Chancellor <nathan@kernel.org> wrote:
> >
> > On Fri, Jun 17, 2022 at 01:39:48PM -0700, Nick Desaulniers wrote:
> > > We're working on providing statically linked images of clang to host on
> > > kernel.org. We're building them in Alpine Linux based Docker containers,
> > > which are MUSL based systems.
> > >
> > > In order to keep bootstrapping simpler, I'd like for them to have an
> > > implicit default --target of x86_64-alpine-linux-musl (set via LLVM's
> > > cmake variable LLVM_DEFAULT_TARGET_TRIPLE).
> > >
> > > Similarly, if one were to use a different build of clang meant for a
> > > glibc or bionic based system on a MUSL based host, we'd prefer to use
> > > the correct MUSL based triple for target hosts.
> > >
> > > Borrowed from the Zen of Python: Explicit is better than implicit. Let's
> > > be explicit about the target triple for HOSTCC when building with
> > > HOSTCC=clang or LLVM=1.


If people try to use the clang packaged by you,
I think the same thing will occur on any project.

I do not understand why you are trying to patch the kernel build?


If this is a problem, it is specific to your clang package,
not to the linux kernel.

You need to find a solution in your package.





> > >
> > > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> >
> > I have tested this with a few different distributions on both aarch64
> > and x86_64:
> >
> > Reviewed-by: Nathan Chancellor <nathan@kernel.org>
> > Tested-by: Nathan Chancellor <nathan@kernel.org>
> >
> > One small comment below.
> >
> > > ---
> > >  Makefile               |  3 +--
> > >  scripts/Makefile.clang | 10 ++++++++++
> > >  2 files changed, 11 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/Makefile b/Makefile
> > > index 1a6678d817bd..87712d9b043c 100644
> > > --- a/Makefile
> > > +++ b/Makefile
> > > @@ -600,10 +600,9 @@ endif
> > >  # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
> > >  # and from include/config/auto.conf.cmd to detect the compiler upgrade.
> > >  CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
> > > +HOSTCC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(HOSTCC) --version 2>/dev/null | head -n 1))
> > >
> > > -ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
> > >  include $(srctree)/scripts/Makefile.clang
> > > -endif
> > >
> > >  # Include this also for config targets because some architectures need
> > >  # cc-cross-prefix to determine CROSS_COMPILE.
> > > diff --git a/scripts/Makefile.clang b/scripts/Makefile.clang
> > > index 87285b76adb2..a4505cd62d7b 100644
> > > --- a/scripts/Makefile.clang
> > > +++ b/scripts/Makefile.clang
> > > @@ -1,3 +1,4 @@
> > > +ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
> > >  # Individual arch/{arch}/Makefiles should use -EL/-EB to set intended
> > >  # endianness and -m32/-m64 to set word size based on Kconfigs instead of
> > >  # relying on the target triple.
> > > @@ -39,3 +40,12 @@ CLANG_FLAGS        += -Werror=ignored-optimization-argument
> > >  KBUILD_CFLAGS        += $(CLANG_FLAGS)
> > >  KBUILD_AFLAGS        += $(CLANG_FLAGS)
> > >  export CLANG_FLAGS
> > > +endif
> > > +
> > > +# If HOSTCC is clang, set the host target triple explicitly; do not rely on
> > > +# implicit defaults.
> > > +ifneq ($(findstring clang,$(HOSTCC_VERSION_TEXT)),)
> > > +HOST_TRIPLE          := --target=$(shell make --version | head -n2 | tail -n1 | cut -d ' ' -f 3)
> >
> > Should we use $(MAKE) instead of make here? I guess the only case where
>
> oh! yeah, good call. I think so.  Will wait until next Tuesday
> (Juneteenth holiday in the US on Monday) to send a v2. Thanks for
> taking a look!
>
> > it would matter is if someone was calling make via an explicit path and
> > did not have it available in their PATH so maybe it is not worth
> > worrying about.
> >
> > > +KBUILD_HOSTCFLAGS    += $(HOST_TRIPLE)
> > > +KBUILD_HOSTLDFLAGS   += $(HOST_TRIPLE)
> > > +endif
> > >
> > > base-commit: 79fe0f863f920c5fcf9dea61676742f813f0b7a6
> > > --
> > > 2.36.1.476.g0c4daa206d-goog
> > >
> > >
>
>
>
> --
> Thanks,
> ~Nick Desaulniers



--
Best Regards
Masahiro Yamada
diff mbox series

Patch

diff --git a/Makefile b/Makefile
index 1a6678d817bd..87712d9b043c 100644
--- a/Makefile
+++ b/Makefile
@@ -600,10 +600,9 @@  endif
 # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
 # and from include/config/auto.conf.cmd to detect the compiler upgrade.
 CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
+HOSTCC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(HOSTCC) --version 2>/dev/null | head -n 1))
 
-ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
 include $(srctree)/scripts/Makefile.clang
-endif
 
 # Include this also for config targets because some architectures need
 # cc-cross-prefix to determine CROSS_COMPILE.
diff --git a/scripts/Makefile.clang b/scripts/Makefile.clang
index 87285b76adb2..a4505cd62d7b 100644
--- a/scripts/Makefile.clang
+++ b/scripts/Makefile.clang
@@ -1,3 +1,4 @@ 
+ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
 # Individual arch/{arch}/Makefiles should use -EL/-EB to set intended
 # endianness and -m32/-m64 to set word size based on Kconfigs instead of
 # relying on the target triple.
@@ -39,3 +40,12 @@  CLANG_FLAGS	+= -Werror=ignored-optimization-argument
 KBUILD_CFLAGS	+= $(CLANG_FLAGS)
 KBUILD_AFLAGS	+= $(CLANG_FLAGS)
 export CLANG_FLAGS
+endif
+
+# If HOSTCC is clang, set the host target triple explicitly; do not rely on
+# implicit defaults.
+ifneq ($(findstring clang,$(HOSTCC_VERSION_TEXT)),)
+HOST_TRIPLE		:= --target=$(shell make --version | head -n2 | tail -n1 | cut -d ' ' -f 3)
+KBUILD_HOSTCFLAGS	+= $(HOST_TRIPLE)
+KBUILD_HOSTLDFLAGS	+= $(HOST_TRIPLE)
+endif