perf clang: Add builtin clang support ant test case
Add basic clang support in clang.cpp and test__clang() testcase. The
first testcase checks if builtin clang is able to generate LLVM IR.
tests/clang.c is a proxy. Real testcase resides in
utils/c++/clang-test.cpp in c++ and exports C interface to perf test
subsystem.
Test result:
$ perf test -v clang
51: builtin clang support :
51.1: Test builtin clang compile C source to IR :
--- start ---
test child forked, pid 13215
test child finished with 0
---- end ----
Test builtin clang support subtest 0: Ok
Committer note:
Make sure you've enabled CLANG and LLVM builtin support by setting
the LIBCLANGLLVM variable on the make command line, e.g.:
make LIBCLANGLLVM=1 O=/tmp/build/perf -C tools/perf install-bin
Otherwise you'll get this when trying to do the 'perf test' call above:
# perf test clang
51: builtin clang support : Skip (not compiled in)
#
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.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/20161126070354.141764-11-wangnan0@huawei.com
[ Removed "Test" from descriptions, redundant and already removed from all the other entries ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/c++/clang.cpp b/tools/perf/util/c++/clang.cpp
new file mode 100644
index 0000000..c17b117
--- /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();
+}
+}