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Date: Thu, 2 Apr 2020 09:39:57 -0700
From: Fangrui Song <maskray@google.com>
Subject: Re: [PATCH v2] Makefile.llvm: simplify LLVM build
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To: 'Nick Desaulniers' via Clang Built Linux <clang-built-linux@googlegroups.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>, Nathan Chancellor <natechancellor@gmail.com>, Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, Sandeep Patil <sspatil@google.com>


On 2020-04-01, 'Nick Desaulniers' via Clang Built Linux wrote:
>On Tue, Mar 31, 2020 at 11:11 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>>
>> On Wed, Apr 1, 2020 at 3:39 AM Nick Desaulniers <ndesaulniers@google.com> wrote:
>> >
>> > On Mon, Mar 30, 2020 at 11:25 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>> > >
>> > > Having both LLVM_DIR and LLVM_SUFFIX seems verbose.
>> >
>> > I agree, so maybe just LLVM=y, and we can support both non-standard
>> > locations and debian suffixes via modifications to PATH.
>>
>>
>>
>> OK, so we will start with the boolean switch 'LLVM'.
>>
>> People can use PATH to cope with directory path and suffixes.
>
>Sounds good, we will modify our CI to use PATH modifications rather
>than suffixes. We can even do that before such a patch to Makefile
>exists.

The proposed LLVM=1 + PATH scheme looks good to me.


There seems to be one issue.
OBJSIZE=llvm-objsize added in
commit fcf1b6a35c16ac500fa908a4022238e5d666eabf "Documentation/llvm: add documentation on building w/ Clang/LLVM"
is wrong.

The tool is named llvm-size. OBJSIZE is only used once:

   arch/s390/scripts/Makefile.chkbss
   14:     if ! $(OBJSIZE) --common $< | $(AWK) 'END { if ($$3) exit 1 }'; then \