Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: perf tools: LIBCLANGLLVM=1 build broken with llvm 7/clang 6
To:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Wang Nan <wangnan0@huawei.com>
CC:     Jiri Olsa <jolsa@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Alexei Starovoitov <ast@fb.com>,
        Martin KaFai Lau <kafai@fb.com>,
        Daniel Borkmann <daniel@iogearbox.net>
References: <20180616122608.GM30043@kernel.org>
From:   Yonghong Song <yhs@fb.com>
Message-ID: <91a76633-54e4-984d-cb68-ca0445146b15@fb.com>
Date:   Sat, 16 Jun 2018 10:20:21 -0700
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:52.0)
 Gecko/20100101 Thunderbird/52.8.0
MIME-Version: 1.0
In-Reply-To: <20180616122608.GM30043@kernel.org>
Content-Type: text/plain; charset="utf-8"; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Received-SPF: None (protection.outlook.com: fb.com does not designate
 permitted sender hosts)
SpamDiagnosticOutput: 1:99
SpamDiagnosticMetadata: NSPM
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Jun 2018 17:20:46.1285 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 92067ff3-053c-4bae-39c3-08d5d3ad8000
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY1PR15MB0078
X-OriginatorOrg: fb.com
X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-06-16_09:,,
 signatures=0
X-Proofpoint-Spam-Reason: safe
X-FB-Internal: Safe
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


On 6/16/18 5:26 AM, Arnaldo Carvalho de Melo wrote:
> Hi Wang, Yogong,
> 
> 	While reviewing the BTF patches for pahole, I updated llvm/clang
> to HEAD and then building perf with clang embedded I noticed this, will
> investigate, posting here to document the regression, maybe this is
> something you came across in other scenario:
> 
>   $ make LIBCLANGLLVM=1 -C tools/perf/
>   <SNIP>
>    CC       /tmp/tmp.t53Qo38zci/tests/kmod-path.o
> util/c++/clang.cpp: In function ‘std::unique_ptr<llvm::SmallVectorImpl<char> > perf::getBPFObjectFromModule(llvm::Module*)’:
> util/c++/clang.cpp:150:43: error: no matching function for call to ‘llvm::TargetMachine::addPassesToEmitFile(llvm::legacy::PassManager&, llvm::raw_svector_ostream&, llvm::TargetMachine::CodeGenFileType)’
>               TargetMachine::CGFT_ObjectFile)) {
>                                             ^
> In file included from util/c++/clang.cpp:25:0:
> /usr/local/include/llvm/Target/TargetMachine.h:254:16: note: candidate: virtual bool llvm::TargetMachine::addPassesToEmitFile(llvm::legacy::PassManagerBase&, llvm::raw_pwrite_stream&, llvm::raw_pwrite_stream*, llvm::TargetMachine::CodeGenFileType, bool, llvm::MachineModuleInfo*)
>     virtual bool addPassesToEmitFile(PassManagerBase &, raw_pwrite_stream &,
>                  ^~~~~~~~~~~~~~~~~~~
> /usr/local/include/llvm/Target/TargetMachine.h:254:16: note:   candidate expects 6 arguments, 3 provided
> mv: cannot stat '/tmp/tmp.t53Qo38zci/util/c++/.clang.o.tmp': No such file or directory
> make[7]: *** [/home/acme/git/perf/tools/build/Makefile.build:101: /tmp/tmp.t53Qo38zci/util/c++/clang.o] Error 1
> make[6]: *** [/home/acme/git/perf/tools/build/Makefile.build:139: c++] Error 2
> make[5]: *** [/home/acme/git/perf/tools/build/Makefile.build:139: util] Error 2
> make[5]: *** Waiting for unfinished jobs....
>    CC       /tmp/tmp.t53Qo38zci/tests/thread-map.o

There is an interface change in llvm 7.0 (trunk) for function 
llvm::TargetMachine::addPassesToEmitFile. The following patch
should fix the problem.

-bash-4.2$ git diff
diff --git a/tools/perf/util/c++/clang.cpp b/tools/perf/util/c++/clang.cpp
index bf31cea..11dee58 100644
--- a/tools/perf/util/c++/clang.cpp
+++ b/tools/perf/util/c++/clang.cpp
@@ -146,8 +146,15 @@ getBPFObjectFromModule(llvm::Module *Module)
         raw_svector_ostream ostream(*Buffer);

         legacy::PassManager PM;
-       if (TargetMachine->addPassesToEmitFile(PM, ostream,
- 
TargetMachine::CGFT_ObjectFile)) {
+       bool NotAdded;
+#if CLANG_VERSION_MAJOR < 7
+       NotAdded = TargetMachine->addPassesToEmitFile(PM, ostream,
+ 
TargetMachine::CGFT_ObjectFile);
+#else
+       NotAdded = TargetMachine->addPassesToEmitFile(PM, ostream, nullptr,
+ 
TargetMachine::CGFT_ObjectFile);
+#endif
+       if (!NotAdded) {
                 llvm::errs() << "TargetMachine can't emit a file of 
this type\n";
                 return 
std::unique_ptr<llvm::SmallVectorImpl<char>>(nullptr);;
         }
-bash-4.2$

Will submit a formal patch soon.

> 
> - Arnaldo
>