[PATCH v3 18/30] perf clang jit: Wrap llvm::Module using PerfModule

[Wang Nan]

Use PerfModule wrap llvm::Module and return perf::PerfModule in APIs to
replace llvm::Module. Following commits are going to add new functions
to PerfModule.

getBPFObjectFromModule is merged to a method of perf::PerfModule.

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxx>
Cc: He Kuang <hekuang@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
---
 tools/perf/util/c++/clang-test.cpp | 10 +++++-----
 tools/perf/util/c++/clang.cpp      | 20 +++++++++++++-------
 tools/perf/util/c++/clang.h        | 22 ++++++++++++++++------
 3 files changed, 34 insertions(+), 18 deletions(-)

diff --git a/tools/perf/util/c++/clang-test.cpp b/tools/perf/util/c++/clang-test.cpp
index 9b11e8c..fb05e56 100644
--- a/tools/perf/util/c++/clang-test.cpp
+++ b/tools/perf/util/c++/clang-test.cpp
@@ -13,18 +13,18 @@ public:
 	~perf_clang_scope() {perf_clang__cleanup();}
 };
 
-static std::unique_ptr<llvm::Module>
+static std::unique_ptr<perf::PerfModule>
 __test__clang_to_IR(void)
 {
 	unsigned int kernel_version;
 
 	if (fetch_kernel_version(&kernel_version, NULL, 0))
-		return std::unique_ptr<llvm::Module>(nullptr);
+		return std::unique_ptr<perf::PerfModule>(nullptr);
 
 	std::string cflag_kver("-DLINUX_VERSION_CODE=" +
 				std::to_string(kernel_version));
 
-	std::unique_ptr<llvm::Module> M =
+	std::unique_ptr<perf::PerfModule> M =
 		perf::getModuleFromSource({cflag_kver.c_str()},
 					  "perf-test.c",
 					  test_llvm__bpf_base_prog);
@@ -39,7 +39,7 @@ int test__clang_to_IR(void)
 	auto M = __test__clang_to_IR();
 	if (!M)
 		return -1;
-	for (llvm::Function& F : *M)
+	for (llvm::Function& F : *(M->getModule()))
 		if (F.getName() == "bpf_func__SyS_epoll_wait")
 			return 0;
 	return -1;
@@ -53,7 +53,7 @@ int test__clang_to_obj(void)
 	if (!M)
 		return -1;
 
-	auto Buffer = perf::getBPFObjectFromModule(&*M);
+	auto Buffer = M->toBPFObject();
 	if (!Buffer)
 		return -1;
 	return 0;
diff --git a/tools/perf/util/c++/clang.cpp b/tools/perf/util/c++/clang.cpp
index 3a3b9791..d31b0a5 100644
--- a/tools/perf/util/c++/clang.cpp
+++ b/tools/perf/util/c++/clang.cpp
@@ -64,7 +64,7 @@ createCompilerInvocation(llvm::opt::ArgStringList CFlags, StringRef& Path,
 	return CI;
 }
 
-static std::unique_ptr<llvm::Module>
+static std::unique_ptr<PerfModule>
 getModuleFromSource(llvm::opt::ArgStringList CFlags,
 		    StringRef Path, IntrusiveRefCntPtr<vfs::FileSystem> VFS)
 {
@@ -80,12 +80,12 @@ getModuleFromSource(llvm::opt::ArgStringList CFlags,
 
 	std::unique_ptr<CodeGenAction> Act(new EmitLLVMOnlyAction(&*LLVMCtx));
 	if (!Clang.ExecuteAction(*Act))
-		return std::unique_ptr<llvm::Module>(nullptr);
+		return std::unique_ptr<PerfModule>(nullptr);
 
-	return Act->takeModule();
+	return std::unique_ptr<PerfModule>(new PerfModule(std::move(Act->takeModule())));
 }
 
-std::unique_ptr<llvm::Module>
+std::unique_ptr<PerfModule>
 getModuleFromSource(llvm::opt::ArgStringList CFlags,
 		    StringRef Name, StringRef Content)
 {
@@ -106,15 +106,21 @@ getModuleFromSource(llvm::opt::ArgStringList CFlags,
 	return getModuleFromSource(std::move(CFlags), Name, OverlayFS);
 }
 
-std::unique_ptr<llvm::Module>
+std::unique_ptr<PerfModule>
 getModuleFromSource(llvm::opt::ArgStringList CFlags, StringRef Path)
 {
 	IntrusiveRefCntPtr<vfs::FileSystem> VFS(vfs::getRealFileSystem());
 	return getModuleFromSource(std::move(CFlags), Path, VFS);
 }
 
+PerfModule::PerfModule(std::unique_ptr<llvm::Module>&& M) : Module(std::move(M))
+{
+
+}
+
+
 std::unique_ptr<llvm::SmallVectorImpl<char>>
-getBPFObjectFromModule(llvm::Module *Module)
+PerfModule::toBPFObject(void)
 {
 	using namespace llvm;
 
@@ -278,7 +284,7 @@ int perf_clang__compile_bpf(const char *_filename,
 	auto M = getModuleFromSource(std::move(CFlags), Opts.getFileName());
 	if (!M)
 		return  -EINVAL;
-	auto O = getBPFObjectFromModule(&*M);
+	auto O = M->toBPFObject();
 	if (!O)
 		return -EINVAL;
 
diff --git a/tools/perf/util/c++/clang.h b/tools/perf/util/c++/clang.h
index dd8b042..cbb291b 100644
--- a/tools/perf/util/c++/clang.h
+++ b/tools/perf/util/c++/clang.h
@@ -11,16 +11,26 @@ namespace perf {
 
 using namespace llvm;
 
-std::unique_ptr<Module>
+class PerfModule {
+private:
+	std::unique_ptr<llvm::Module> Module;
+public:
+	inline llvm::Module *getModule(void)
+	{
+		return Module.get();
+	}
+
+	PerfModule(std::unique_ptr<llvm::Module>&& M);
+
+	std::unique_ptr<llvm::SmallVectorImpl<char>> toBPFObject(void);
+};
+
+std::unique_ptr<PerfModule>
 getModuleFromSource(opt::ArgStringList CFlags,
 		    StringRef Name, StringRef Content);
 
-std::unique_ptr<Module>
+std::unique_ptr<PerfModule>
 getModuleFromSource(opt::ArgStringList CFlags,
 		    StringRef Path);
-
-std::unique_ptr<llvm::SmallVectorImpl<char>>
-getBPFObjectFromModule(llvm::Module *Module);
-
 }
 #endif
-- 
2.10.1