Re: perf tools: LIBCLANGLLVM=1 build broken with llvm 7/clang 6

From: Yonghong Song
Date: Mon Jun 18 2018 - 11:11:20 EST




On 6/18/18 7:31 AM, Arnaldo Carvalho de Melo wrote:
Em Sat, Jun 16, 2018 at 10:20:21AM -0700, Yonghong Song escreveu:


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 âstd::unique_ptr<llvm::SmallVectorImpl<char> > perf::getBPFObjectFromModule(llvm::Module*)â:
util/c++/clang.cpp:150:43: error: no matching function for call to âllvm::TargetMachine::addPassesToEmitFile(llvm::legacy::PassManager&, llvm::raw_svector_ostream&, llvm::TargetMachine::CodeGenFileType)â
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.

Please submit it, I just tested and the the build finishes Ok.

The formal patch is here:
https://lkml.org/lkml/2018/6/16/92


- Arnaldo
-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