1 files changed, 96 insertions, 0 deletions

diff --git a/tools/perf/util/c++/clang.cpp b/tools/perf/util/c++/clang.cpp
new file mode 100644
index 000000000000..c17b1176e25d
--- /dev/null
+++ b/tools/perf/util/c++/clang.cpp
@@ -0,0 +1,96 @@
+/*
+ * llvm C frontend for perf. Support dynamically compile C file
+ *
+ * Inspired by clang example code:
+ * http://llvm.org/svn/llvm-project/cfe/trunk/examples/clang-interpreter/main.cpp
+ *
+ * Copyright (C) 2016 Wang Nan <wangnan0@huawei.com>
+ * Copyright (C) 2016 Huawei Inc.
+ */
+
+#include "clang/CodeGen/CodeGenAction.h"
+#include "clang/Frontend/CompilerInvocation.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "clang/Tooling/Tooling.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Option/Option.h"
+#include "llvm/Support/ManagedStatic.h"
+#include <memory>
+
+#include "clang.h"
+#include "clang-c.h"
+
+namespace perf {
+
+static std::unique_ptr<llvm::LLVMContext> LLVMCtx;
+
+using namespace clang;
+
+static vfs::InMemoryFileSystem *
+buildVFS(StringRef& Name, StringRef& Content)
+{
+        vfs::InMemoryFileSystem *VFS = new vfs::InMemoryFileSystem(true);
+        VFS->addFile(Twine(Name), 0, llvm::MemoryBuffer::getMemBuffer(Content));
+        return VFS;
+}
+
+static CompilerInvocation *
+createCompilerInvocation(StringRef& Path, DiagnosticsEngine& Diags)
+{
+        llvm::opt::ArgStringList CCArgs {
+                "-cc1",
+                "-triple", "bpf-pc-linux",
+                "-fsyntax-only",
+                "-ferror-limit", "19",
+                "-fmessage-length", "127",
+                "-O2",
+                "-nostdsysteminc",
+                "-nobuiltininc",
+                "-vectorize-loops",
+                "-vectorize-slp",
+                "-Wno-unused-value",
+                "-Wno-pointer-sign",
+                "-x", "c"};
+        CompilerInvocation *CI = tooling::newInvocation(&Diags, CCArgs);
+
+        FrontendOptions& Opts = CI->getFrontendOpts();
+        Opts.Inputs.clear();
+        Opts.Inputs.emplace_back(Path, IK_C);
+        return CI;
+}
+
+std::unique_ptr<llvm::Module>
+getModuleFromSource(StringRef Name, StringRef Content)
+{
+        CompilerInstance Clang;
+        Clang.createDiagnostics();
+
+        IntrusiveRefCntPtr<vfs::FileSystem> VFS = buildVFS(Name, Content);
+        Clang.setVirtualFileSystem(&*VFS);
+
+        IntrusiveRefCntPtr<CompilerInvocation> CI =
+                createCompilerInvocation(Name, Clang.getDiagnostics());
+        Clang.setInvocation(&*CI);
+
+        std::unique_ptr<CodeGenAction> Act(new EmitLLVMOnlyAction(&*LLVMCtx));
+        if (!Clang.ExecuteAction(*Act))
+                return std::unique_ptr<llvm::Module>(nullptr);
+
+        return Act->takeModule();
+}
+
+}
+
+extern "C" {
+void perf_clang__init(void)
+{
+        perf::LLVMCtx.reset(new llvm::LLVMContext());
+}
+
+void perf_clang__cleanup(void)
+{
+        perf::LLVMCtx.reset(nullptr);
+        llvm::llvm_shutdown();
+}
+}