linux/tools/perf/util/c++/clang.cpp
Wang Nan a9495fe9dc perf clang: Allow passing CFLAGS to builtin clang
Improve getModuleFromSource() API to accept a cflags list. This feature
will be used to pass LINUX_VERSION_CODE and -I flags.

Signed-off-by: Wang 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/20161126070354.141764-13-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-12-05 15:51:44 -03:00

122 lines
3.0 KiB
C++

/*
* 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/FileSystem.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 CompilerInvocation *
createCompilerInvocation(llvm::opt::ArgStringList CFlags, 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"};
CCArgs.append(CFlags.begin(), CFlags.end());
CompilerInvocation *CI = tooling::newInvocation(&Diags, CCArgs);
FrontendOptions& Opts = CI->getFrontendOpts();
Opts.Inputs.clear();
Opts.Inputs.emplace_back(Path, IK_C);
return CI;
}
static std::unique_ptr<llvm::Module>
getModuleFromSource(llvm::opt::ArgStringList CFlags,
StringRef Path, IntrusiveRefCntPtr<vfs::FileSystem> VFS)
{
CompilerInstance Clang;
Clang.createDiagnostics();
Clang.setVirtualFileSystem(&*VFS);
IntrusiveRefCntPtr<CompilerInvocation> CI =
createCompilerInvocation(std::move(CFlags), Path,
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();
}
std::unique_ptr<llvm::Module>
getModuleFromSource(llvm::opt::ArgStringList CFlags,
StringRef Name, StringRef Content)
{
using namespace vfs;
llvm::IntrusiveRefCntPtr<OverlayFileSystem> OverlayFS(
new OverlayFileSystem(getRealFileSystem()));
llvm::IntrusiveRefCntPtr<InMemoryFileSystem> MemFS(
new InMemoryFileSystem(true));
/*
* pushOverlay helps setting working dir for MemFS. Must call
* before addFile.
*/
OverlayFS->pushOverlay(MemFS);
MemFS->addFile(Twine(Name), 0, llvm::MemoryBuffer::getMemBuffer(Content));
return getModuleFromSource(std::move(CFlags), Name, OverlayFS);
}
std::unique_ptr<llvm::Module>
getModuleFromSource(llvm::opt::ArgStringList CFlags, StringRef Path)
{
IntrusiveRefCntPtr<vfs::FileSystem> VFS(vfs::getRealFileSystem());
return getModuleFromSource(std::move(CFlags), Path, VFS);
}
}
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();
}
}