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[OpenMP] Implement save temps functionality in linker wrapper
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Summary:
This patch implements the `-save-temps` flag for the linker wrapper.
This allows the user to inspect the intermeditary outpout that the
linker wrapper creates.
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@jhuber6
jhuber6 committed Feb 1, 2022
1 parent a47b1cf commit bf499c5
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Showing 2 changed files with 85 additions and 69 deletions.
2 changes: 2 additions & 0 deletions clang/lib/Driver/ToolChains/Clang.cpp
View file
Expand Up @@ -8244,6 +8244,8 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
if (const Arg *A = Args.getLastArg(options::OPT_Rpass_analysis_EQ))
CmdArgs.push_back(
Args.MakeArgString(Twine("-pass-remarks-analysis=") + A->getValue()));
if (Args.getLastArg(options::OPT_save_temps_EQ))
CmdArgs.push_back("-save-temps");

// Add the linker arguments to be forwarded by the wrapper.
CmdArgs.push_back("-linker-path");
Expand Down
152 changes: 83 additions & 69 deletions clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp
View file
Expand Up @@ -111,6 +111,10 @@ static cl::opt<DebugKind> DebugInfo(
"Direction information"),
clEnumValN(FullDebugInfo, "g", "Full debugging support")));

static cl::opt<bool> SaveTemps("save-temps", cl::ZeroOrMore,
cl::desc("Save intermediary results."),
cl::cat(ClangLinkerWrapperCategory));

// Do not parse linker options.
static cl::list<std::string>
HostLinkerArgs(cl::Positional,
Expand Down Expand Up @@ -157,6 +161,21 @@ static StringRef getDeviceFileExtension(StringRef DeviceTriple,
return "o";
}

Error createOutputFile(const Twine &Prefix, StringRef Extension,
SmallString<128> &NewFilename) {
if (!SaveTemps) {
if (std::error_code EC =
sys::fs::createTemporaryFile(Prefix, Extension, NewFilename))
return createFileError(NewFilename, EC);
TempFiles.push_back(static_cast<std::string>(NewFilename));
} else {
const Twine &Filename = Prefix + "." + Extension;
Filename.toNullTerminatedStringRef(NewFilename);
}

return Error::success();
}

Error runLinker(std::string &LinkerPath, SmallVectorImpl<std::string> &Args) {
std::vector<StringRef> LinkerArgs;
LinkerArgs.push_back(LinkerPath);
Expand Down Expand Up @@ -204,11 +223,8 @@ void removeFromCompilerUsed(Module &M, GlobalValue &Value) {
Expected<Optional<std::string>>
extractFromBinary(const ObjectFile &Obj,
SmallVectorImpl<DeviceFile> &DeviceFiles) {

StringRef Extension = sys::path::extension(Obj.getFileName()).drop_front();
StringRef Prefix = sys::path::stem(Obj.getFileName()).take_until([](char C) {
return C == '-';
});
StringRef Prefix = sys::path::stem(Obj.getFileName());
SmallVector<StringRef, 4> ToBeStripped;

// Extract data from sections of the form `.llvm.offloading.<triple>.<arch>`.
Expand All @@ -226,10 +242,9 @@ extractFromBinary(const ObjectFile &Obj,
SmallString<128> TempFile;
StringRef DeviceExtension = getDeviceFileExtension(
DeviceTriple, identify_magic(*Contents) == file_magic::bitcode);
if (std::error_code EC = sys::fs::createTemporaryFile(
Prefix + "-device-" + DeviceTriple, DeviceExtension, TempFile))
return createFileError(TempFile, EC);
TempFiles.push_back(static_cast<std::string>(TempFile));
if (Error Err = createOutputFile(Prefix + "-device-" + DeviceTriple,
DeviceExtension, TempFile))
return std::move(Err);

Expected<std::unique_ptr<FileOutputBuffer>> OutputOrErr =
FileOutputBuffer::create(TempFile, Sec.getSize());
Expand All @@ -253,10 +268,9 @@ extractFromBinary(const ObjectFile &Obj,
SmallString<128> StripFile = Obj.getFileName();
if (!sys::fs::exists(StripFile)) {
SmallString<128> TempFile;
if (std::error_code EC = sys::fs::createTemporaryFile(
sys::path::stem(StripFile), "o", TempFile))
return createFileError(TempFile, EC);
TempFiles.push_back(static_cast<std::string>(TempFile));
if (Error Err = createOutputFile(sys::path::stem(StripFile),
sys::path::extension(StripFile), TempFile))
return std::move(Err);

auto Contents = Obj.getMemoryBufferRef().getBuffer();
Expected<std::unique_ptr<FileOutputBuffer>> OutputOrErr =
Expand All @@ -278,10 +292,8 @@ extractFromBinary(const ObjectFile &Obj,
"Unable to find 'llvm-strip' in path");

SmallString<128> TempFile;
if (std::error_code EC =
sys::fs::createTemporaryFile(Prefix + "-host", Extension, TempFile))
return createFileError(TempFile, EC);
TempFiles.push_back(static_cast<std::string>(TempFile));
if (Error Err = createOutputFile(Prefix + "-host", Extension, TempFile))
return std::move(Err);

SmallVector<StringRef, 8> StripArgs;
StripArgs.push_back(*StripPath);
Expand Down Expand Up @@ -336,10 +348,9 @@ extractFromBitcode(std::unique_ptr<MemoryBuffer> Buffer,
SmallString<128> TempFile;
StringRef DeviceExtension = getDeviceFileExtension(
DeviceTriple, identify_magic(Contents) == file_magic::bitcode);
if (std::error_code EC = sys::fs::createTemporaryFile(
Prefix + "-device-" + DeviceTriple, DeviceExtension, TempFile))
return createFileError(TempFile, EC);
TempFiles.push_back(static_cast<std::string>(TempFile));
if (Error Err = createOutputFile(Prefix + "-device-" + DeviceTriple,
DeviceExtension, TempFile))
return std::move(Err);

Expected<std::unique_ptr<FileOutputBuffer>> OutputOrErr =
FileOutputBuffer::create(TempFile, Contents.size());
Expand Down Expand Up @@ -368,10 +379,8 @@ extractFromBitcode(std::unique_ptr<MemoryBuffer> Buffer,
}

SmallString<128> TempFile;
if (std::error_code EC =
sys::fs::createTemporaryFile(Prefix + "-host", Extension, TempFile))
return createFileError(TempFile, EC);
TempFiles.push_back(static_cast<std::string>(TempFile));
if (Error Err = createOutputFile(Prefix + "-host", Extension, TempFile))
return std::move(Err);

std::error_code EC;
raw_fd_ostream HostOutput(TempFile, EC, sys::fs::OF_None);
Expand All @@ -385,13 +394,6 @@ Expected<Optional<std::string>>
extractFromArchive(const Archive &Library,
SmallVectorImpl<DeviceFile> &DeviceFiles) {

StringRef Extension =
sys::path::extension(Library.getFileName()).drop_front();
StringRef Prefix =
sys::path::stem(Library.getFileName()).take_until([](char C) {
return C == '-';
});

bool NewMembers = false;
SmallVector<NewArchiveMember, 8> Members;

Expand Down Expand Up @@ -440,10 +442,9 @@ extractFromArchive(const Archive &Library,

// Create a new static library using the stripped host files.
SmallString<128> TempFile;
if (std::error_code EC =
sys::fs::createTemporaryFile(Prefix + "-host", Extension, TempFile))
return createFileError(TempFile, EC);
TempFiles.push_back(static_cast<std::string>(TempFile));
StringRef Prefix = sys::path::stem(Library.getFileName());
if (Error Err = createOutputFile(Prefix + "-host", "a", TempFile))
return std::move(Err);

std::unique_ptr<MemoryBuffer> Buffer =
MemoryBuffer::getMemBuffer(Library.getMemoryBufferRef(), false);
Expand Down Expand Up @@ -500,10 +501,9 @@ Expected<std::string> assemble(StringRef InputFile, Triple TheTriple,

// Create a new file to write the linked device image to.
SmallString<128> TempFile;
if (std::error_code EC = sys::fs::createTemporaryFile(
if (Error Err = createOutputFile(
"lto-" + TheTriple.getArchName() + "-" + Arch, "cubin", TempFile))
return createFileError(TempFile, EC);
TempFiles.push_back(static_cast<std::string>(TempFile));
return std::move(Err);

// TODO: Pass in arguments like `-g` and `-v` from the driver.
SmallVector<StringRef, 16> CmdArgs;
Expand Down Expand Up @@ -544,10 +544,9 @@ Expected<std::string> link(ArrayRef<std::string> InputFiles,

// Create a new file to write the linked device image to.
SmallString<128> TempFile;
if (std::error_code EC = sys::fs::createTemporaryFile(
if (Error Err = createOutputFile(
TheTriple.getArchName() + "-" + Arch + "-image", "out", TempFile))
return createFileError(TempFile, EC);
TempFiles.push_back(static_cast<std::string>(TempFile));
return std::move(Err);

SmallVector<StringRef, 16> CmdArgs;
CmdArgs.push_back(*NvlinkPath);
Expand Down Expand Up @@ -591,10 +590,9 @@ Expected<std::string> link(ArrayRef<std::string> InputFiles,

// Create a new file to write the linked device image to.
SmallString<128> TempFile;
if (std::error_code EC = sys::fs::createTemporaryFile(
if (Error Err = createOutputFile(
TheTriple.getArchName() + "-" + Arch + "-image", "out", TempFile))
return createFileError(TempFile, EC);
TempFiles.push_back(static_cast<std::string>(TempFile));
return std::move(Err);

SmallVector<StringRef, 16> CmdArgs;
CmdArgs.push_back(*LLDPath);
Expand Down Expand Up @@ -710,6 +708,26 @@ std::unique_ptr<lto::LTO> createLTO(
Conf.PTO.LoopVectorization = Conf.OptLevel > 1;
Conf.PTO.SLPVectorization = Conf.OptLevel > 1;

if (SaveTemps) {
auto HandleError = [&](Error Err) {
logAllUnhandledErrors(std::move(Err),
WithColor::error(errs(), LinkerExecutable));
exit(1);
};
Conf.PostInternalizeModuleHook = [&](size_t, const Module &M) {
SmallString<128> TempFile;
if (Error Err =
createOutputFile("lto-" + TheTriple.getTriple(), "bc", TempFile))
HandleError(std::move(Err));

std::error_code EC;
raw_fd_ostream LinkedBitcode(TempFile, EC, sys::fs::OF_None);
if (EC)
HandleError(errorCodeToError(EC));
WriteBitcodeToFile(M, LinkedBitcode);
return true;
};
}
Conf.PostOptModuleHook = Hook;
if (TheTriple.isNVPTX())
Conf.CGFileType = CGFT_AssemblyFile;
Expand Down Expand Up @@ -783,33 +801,33 @@ Error linkBitcodeFiles(SmallVectorImpl<std::string> &InputFiles,

assert(!BitcodeLibrary.empty() && "Bitcode linking without `-foffload-lto`");

auto HandleError = [&](std::error_code EC) {
logAllUnhandledErrors(errorCodeToError(EC),
auto HandleError = [&](Error Err) {
logAllUnhandledErrors(std::move(Err),
WithColor::error(errs(), LinkerExecutable));
exit(1);
};

// LTO Module hook to output bitcode without running the backend.
auto LinkOnly = [&](size_t Task, const Module &M) {
auto OutputBitcode = [&](size_t Task, const Module &M) {
SmallString<128> TempFile;
if (std::error_code EC = sys::fs::createTemporaryFile(
"jit-" + TheTriple.getTriple(), "bc", TempFile))
HandleError(EC);
if (Error Err =
createOutputFile("jit-" + TheTriple.getTriple(), "bc", TempFile))
HandleError(std::move(Err));

std::error_code EC;
raw_fd_ostream LinkedBitcode(TempFile, EC, sys::fs::OF_None);
if (EC)
HandleError(EC);
HandleError(errorCodeToError(EC));
WriteBitcodeToFile(M, LinkedBitcode);
TempFiles.push_back(static_cast<std::string>(TempFile));
NewInputFiles.push_back(static_cast<std::string>(TempFile));
return false;
};

// We assume visibility of the whole program if every input file was bitcode.
bool WholeProgram = BitcodeFiles.size() == InputFiles.size();
auto LTOBackend = (EmbedBitcode)
? createLTO(TheTriple, Arch, WholeProgram, LinkOnly)
: createLTO(TheTriple, Arch, WholeProgram);
auto LTOBackend =
(EmbedBitcode) ? createLTO(TheTriple, Arch, WholeProgram, OutputBitcode)
: createLTO(TheTriple, Arch, WholeProgram);

// We need to resolve the symbols so the LTO backend knows which symbols need
// to be kept or can be internalized. This is a simplified symbol resolution
Expand Down Expand Up @@ -869,9 +887,11 @@ Error linkBitcodeFiles(SmallVectorImpl<std::string> &InputFiles,
int FD = -1;
auto &TempFile = Files[Task];
StringRef Extension = (TheTriple.isNVPTX()) ? "s" : "o";
if (std::error_code EC = sys::fs::createTemporaryFile(
"lto-" + TheTriple.getTriple(), Extension, FD, TempFile))
HandleError(EC);
if (Error Err = createOutputFile("lto-" + TheTriple.getTriple(), Extension,
TempFile))
HandleError(std::move(Err));
if (std::error_code EC = sys::fs::openFileForWrite(TempFile, FD))
HandleError(errorCodeToError(EC));
TempFiles.push_back(static_cast<std::string>(TempFile));
return std::make_unique<CachedFileStream>(
std::make_unique<llvm::raw_fd_ostream>(FD, true));
Expand Down Expand Up @@ -947,17 +967,13 @@ Expected<std::string> wrapDeviceImage(StringRef ImageFile) {

// Create a new file to write the wrapped bitcode file to.
SmallString<128> BitcodeFile;
if (std::error_code EC =
sys::fs::createTemporaryFile("wrapper", "bc", BitcodeFile))
return createFileError(BitcodeFile, EC);
TempFiles.push_back(static_cast<std::string>(BitcodeFile));
if (Error Err = createOutputFile("offload-wrapper", "bc", BitcodeFile))
return std::move(Err);

// TODO: Optionally pass the host triple in somewhere.
Triple HostTriple(sys::getDefaultTargetTriple());
SmallVector<StringRef, 4> WrapperArgs;
WrapperArgs.push_back(*WrapperPath);
WrapperArgs.push_back("-target");
WrapperArgs.push_back(HostTriple.getTriple());
WrapperArgs.push_back(HostTriple);
WrapperArgs.push_back("-o");
WrapperArgs.push_back(BitcodeFile);
WrapperArgs.push_back(ImageFile);
Expand All @@ -973,10 +989,8 @@ Expected<std::string> wrapDeviceImage(StringRef ImageFile) {

// Create a new file to write the wrapped bitcode file to.
SmallString<128> ObjectFile;
if (std::error_code EC =
sys::fs::createTemporaryFile("image", "o", ObjectFile))
return createFileError(BitcodeFile, EC);
TempFiles.push_back(static_cast<std::string>(ObjectFile));
if (Error Err = createOutputFile("offload-wrapper", "o", ObjectFile))
return std::move(Err);

SmallVector<StringRef, 4> CompilerArgs;
CompilerArgs.push_back(*CompilerPath);
Expand Down

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