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Commit 5e08a765 authored by Wang Nan's avatar Wang Nan Committed by Arnaldo Carvalho de Melo
Browse files

perf clang: Support compile IR to BPF object and add testcase 



getBPFObjectFromModule() is introduced to compile LLVM IR(Module)
to BPF object. Add new testcase for it.

Test result:
  $ ./buildperf/perf test -v clang
  51: builtin clang support                               :
  51.1: builtin clang compile C source to IR              :
  --- start ---
  test child forked, pid 21822
  test child finished with 0
  ---- end ----
  builtin clang support subtest 0: Ok
  51.2: builtin clang compile C source to ELF object      :
  --- start ---
  test child forked, pid 21823
  test child finished with 0
  ---- end ----
  builtin clang support subtest 1: Ok

Signed-off-by: default avatarWang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Joe Stringer <joe@ovn.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/20161126070354.141764-15-wangnan0@huawei.com


[ Remove redundant "Test" from entry descriptions ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent e67d52d4

tools/perf/tests/clang.c

+5 −1
Original line number Diff line number Diff line
@@ -12,6 +12,10 @@ static struct { 
		.func = test__clang_to_IR,

		.desc = "builtin clang compile C source to IR",

	},

	{

		.func = test__clang_to_obj,

		.desc = "builtin clang compile C source to ELF object",

	},

#endif

};
@@ -33,7 +37,7 @@ int test__clang(int i __maybe_unused) 
	return TEST_SKIP;

}

#else

int test__clang(int i __maybe_unused)

int test__clang(int i)

{

	if (i < 0 || i >= (int)ARRAY_SIZE(clang_testcase_table))

		return TEST_FAIL;

tools/perf/util/c++/clang-c.h

+1 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ extern void perf_clang__init(void); 
extern void perf_clang__cleanup(void);



extern int test__clang_to_IR(void);

extern int test__clang_to_obj(void);



#ifdef __cplusplus

}

tools/perf/util/c++/clang-test.cpp

+25 −6
Original line number Diff line number Diff line
@@ -13,15 +13,13 @@ public: 
	~perf_clang_scope() {perf_clang__cleanup();}

};



extern "C" {



int test__clang_to_IR(void)

static std::unique_ptr<llvm::Module>

__test__clang_to_IR(void)

{

	perf_clang_scope _scope;

	unsigned int kernel_version;



	if (fetch_kernel_version(&kernel_version, NULL, 0))

		return -1;

		return std::unique_ptr<llvm::Module>(nullptr);



	std::string cflag_kver("-DLINUX_VERSION_CODE=" +

				std::to_string(kernel_version));
@@ -30,14 +28,35 @@ int test__clang_to_IR(void) 
		perf::getModuleFromSource({cflag_kver.c_str()},

					  "perf-test.c",

					  test_llvm__bpf_base_prog);

	return M;

}



extern "C" {

int test__clang_to_IR(void)

{

	perf_clang_scope _scope;



	auto M = __test__clang_to_IR();

	if (!M)

		return -1;



	for (llvm::Function& F : *M)

		if (F.getName() == "bpf_func__SyS_epoll_wait")

			return 0;

	return -1;

}



int test__clang_to_obj(void)

{

	perf_clang_scope _scope;



	auto M = __test__clang_to_IR();

	if (!M)

		return -1;



	auto Buffer = perf::getBPFObjectFromModule(&*M);

	if (!Buffer)

		return -1;

	return 0;

}



}

tools/perf/util/c++/clang.cpp

+45 −0
Original line number Diff line number Diff line
@@ -13,10 +13,15 @@ 
#include "clang/Frontend/CompilerInstance.h"

#include "clang/Frontend/TextDiagnosticPrinter.h"

#include "clang/Tooling/Tooling.h"

#include "llvm/IR/LegacyPassManager.h"

#include "llvm/IR/Module.h"

#include "llvm/Option/Option.h"

#include "llvm/Support/FileSystem.h"

#include "llvm/Support/ManagedStatic.h"

#include "llvm/Support/TargetRegistry.h"

#include "llvm/Support/TargetSelect.h"

#include "llvm/Target/TargetMachine.h"

#include "llvm/Target/TargetOptions.h"

#include <memory>



#include "clang.h"
@@ -105,12 +110,52 @@ getModuleFromSource(llvm::opt::ArgStringList CFlags, StringRef Path) 
	return getModuleFromSource(std::move(CFlags), Path, VFS);

}



std::unique_ptr<llvm::SmallVectorImpl<char>>

getBPFObjectFromModule(llvm::Module *Module)

{

	using namespace llvm;



	std::string TargetTriple("bpf-pc-linux");

	std::string Error;

	const Target* Target = TargetRegistry::lookupTarget(TargetTriple, Error);

	if (!Target) {

		llvm::errs() << Error;

		return std::unique_ptr<llvm::SmallVectorImpl<char>>(nullptr);

	}



	llvm::TargetOptions Opt;

	TargetMachine *TargetMachine =

		Target->createTargetMachine(TargetTriple,

					    "generic", "",

					    Opt, Reloc::Static);



	Module->setDataLayout(TargetMachine->createDataLayout());

	Module->setTargetTriple(TargetTriple);



	std::unique_ptr<SmallVectorImpl<char>> Buffer(new SmallVector<char, 0>());

	raw_svector_ostream ostream(*Buffer);



	legacy::PassManager PM;

	if (TargetMachine->addPassesToEmitFile(PM, ostream,

					       TargetMachine::CGFT_ObjectFile)) {

		llvm::errs() << "TargetMachine can't emit a file of this type\n";

		return std::unique_ptr<llvm::SmallVectorImpl<char>>(nullptr);;

	}

	PM.run(*Module);



	return std::move(Buffer);

}



}



extern "C" {

void perf_clang__init(void)

{

	perf::LLVMCtx.reset(new llvm::LLVMContext());

	LLVMInitializeBPFTargetInfo();

	LLVMInitializeBPFTarget();

	LLVMInitializeBPFTargetMC();

	LLVMInitializeBPFAsmPrinter();

}



void perf_clang__cleanup(void)

tools/perf/util/c++/clang.h

+3 −0
Original line number Diff line number Diff line
@@ -19,5 +19,8 @@ std::unique_ptr<Module> 
getModuleFromSource(opt::ArgStringList CFlags,

		    StringRef Path);



std::unique_ptr<llvm::SmallVectorImpl<char>>

getBPFObjectFromModule(llvm::Module *Module);



}

#endif