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From:   Zhangjin Wu <falcon@tinylab.org>
To:     w@1wt.eu
Cc:     falcon@tinylab.org, arnd@arndb.de, linux-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org, linux@weissschuh.net,
        thomas@t-8ch.de, Yuan Tan <tanyuan@tinylab.org>
Subject: Re: [PATCH v2 3/3] selftests/nolibc: fix up O= option support
Date:   Sat, 26 Aug 2023 12:30:46 +0800
Message-Id: <20230826043046.53692-1-falcon@tinylab.org>
In-Reply-To: <20230806121721.30774-1-falcon@tinylab.org>
References: <20230806121721.30774-1-falcon@tinylab.org>
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Hi, Willy

> > On Sat, Aug 05, 2023 at 02:13:11PM +0800, Zhangjin Wu wrote:
> > > To avoid pollute the source code tree and avoid mrproper for every
> > > architecture switch, the O= argument must be supported.
> > > 
> > > Both IMAGE and .config are from the building directory, let's use
> > > objtree instead of srctree for them.
> > > 
> > > If no O= option specified, means building kernel in source code tree,
> > > objtree should be srctree in such case.
> > > 
> > > To support relative path, as suggested by Thomas, $(COMMAND_O) is used
> > > to pass the O=$(ABSOLUTE_O) to the $(MAKE) commands.
> > 
> > Zhangjin, I cannot get this one to work, regardless of what I try:
> > 
> >    $ make -j8 O=$PWD/output-i386 nolibc-test XARCH=i386 CROSS_COMPILE=/f/tc/nolibc/gcc-12.3.0-nolibc/i386-linux/bin/i386-linux- CC=/f/tc/nolibc/gcc-12.3.0-nolibc/i386-linux/bin/i386-linux-gcc
> >    (...)
> >    CC      nolibc-test
> >    In file included from sysroot/i386/include/stdio.h:14,
> >                     from nolibc-test.c:13:
> >    sysroot/i386/include/errno.h:10:10: fatal error: asm/errno.h: No such file or directory
> >       10 | #include <asm/errno.h>
> >          |          ^~~~~~~~~~~~~
> >    compilation terminated.
> >
> 
> Willy, I also just reproduced the issue, seems only i386 sysroot has no
> asm/errno.h, will check why it is no rightly installed later.
> 
>     $ find sysroot/ -name "errno.h"
>     sysroot/arm/include/errno.h
>     sysroot/arm/include/asm-generic/errno.h
>     sysroot/arm/include/asm/errno.h
>     sysroot/arm/include/linux/errno.h
>     sysroot/riscv/include/errno.h
>     sysroot/riscv/include/asm-generic/errno.h
>     sysroot/riscv/include/asm/errno.h
>     sysroot/riscv/include/linux/errno.h
>     sysroot/s390/include/errno.h
>     sysroot/s390/include/asm-generic/errno.h
>     sysroot/s390/include/asm/errno.h
>     sysroot/s390/include/linux/errno.h
>     sysroot/arm64/include/errno.h
>     sysroot/arm64/include/asm-generic/errno.h
>     sysroot/arm64/include/asm/errno.h
>     sysroot/arm64/include/linux/errno.h
>     sysroot/mips/include/errno.h
>     sysroot/mips/include/asm-generic/errno.h
>     sysroot/mips/include/asm/errno.h
>     sysroot/mips/include/linux/errno.h
>     sysroot/x86_64/include/errno.h
>     sysroot/x86_64/include/asm-generic/errno.h
>     sysroot/x86_64/include/asm/errno.h
>     sysroot/x86_64/include/linux/errno.h
>     sysroot/i386/include/errno.h
>     sysroot/i386/include/asm-generic/errno.h
>     sysroot/i386/include/linux/errno.h
>     sysroot/powerpc/include/errno.h
>     sysroot/powerpc/include/asm-generic/errno.h
>     sysroot/powerpc/include/asm/errno.h
>     sysroot/powerpc/include/linux/errno.h
> 
> > I'll leave it aside for now as I've spent way longer than I hoped on
> > these series. I could take the previous two patches however.
> >
> 
> Ok, let's ignore this one, I will find why sysroot not install well for i386.
>

Thanks to Yuan, he have done some testing and have found the root cause, that
is mrproper on top-level source code tree is required before installing
sysroot, otherwise, the 'generated' headers will not be installed (removed by
scripts/Makefile.asm-generic).

After mrproper (not with O=out, must on top-level source code tree), the
asm/errno.h will be there:

    ubuntu@linux-lab:/labs/linux-lab/src/linux-stable/tools/testing/selftests/nolibc$ find sysroot/ -name "errno.h"
    sysroot/i386/include/errno.h
    sysroot/i386/include/asm-generic/errno.h
    sysroot/i386/include/asm/errno.h             --> here it is
    sysroot/i386/include/linux/errno.h
    sysroot/x86/include/errno.h
    sysroot/x86/include/asm-generic/errno.h
    sysroot/x86/include/asm/errno.h              --> here it is
    sysroot/x86/include/linux/errno.h

That also means, to use O=out for run-user, we also need to use O=out for
defconfig (and kernel ...) too, otherwise, the top-level source code tree will
be polluated.

Seems a manual mrproper on top-level source code tree is always required for a
new iteration, so, it may be ok to pick this patch with a note on the potential
error.

Best Regards,
Zhangjin

> Thanks,
> Zhangjin
> 
> > Thanks,
> > Willy