linux/tools/perf/util/c++/clang.cpp
Wang Nan 00b86691c7 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>
2016-12-05 15:51:43 -03:00

97 lines
2.3 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/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();
}
}