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llvm-project/llvm/lib/LTO/LTO.cpp
Teresa Johnson 8dd61aee30 [LTO] Fix handling of mixed (regular and thin) mode LTO 
Summary:
In runThinLTO we start the task numbering for ThinLTO backend
tasks depending on whether there was also a regular LTO object
(CombinedModule). However, the CombinedModule is moved at
the end of runRegularLTO, so we need to save this information and
pass it into runThinLTO. Otherwise the AddOutput callback to the client
will use the same task number for both the regular LTO object
and the first ThinLTO object, which in gold-plugin caused only
one to be end up in the output filename array and therefore passed
back to gold for the final native link.

Reviewers: pcc, mehdi_amini

Subscribers: mehdi_amini, kromanova

Differential Revision: https://reviews.llvm.org/D24643

llvm-svn: 281725
2016-09-16 13:54:19 +00:00

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//===-LTO.cpp - LLVM Link Time Optimizer ----------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements functions and classes used to support LTO.
//
//===----------------------------------------------------------------------===//
#include "llvm/LTO/LTO.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/IR/AutoUpgrade.h"
#include "llvm/IR/DiagnosticPrinter.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/LTO/LTOBackend.h"
#include "llvm/Linker/IRMover.h"
#include "llvm/Object/ModuleSummaryIndexObjectFile.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/SHA1.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/ThreadPool.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/IPO/PassManagerBuilder.h"
#include "llvm/Transforms/Utils/SplitModule.h"
#include <set>
using namespace llvm;
using namespace lto;
using namespace object;
#define DEBUG_TYPE "lto"
// Returns a unique hash for the Module considering the current list of
// export/import and other global analysis results.
// The hash is produced in \p Key.
static void computeCacheKey(
SmallString<40> &Key, const ModuleSummaryIndex &Index, StringRef ModuleID,
const FunctionImporter::ImportMapTy &ImportList,
const FunctionImporter::ExportSetTy &ExportList,
const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
const GVSummaryMapTy &DefinedGlobals) {
// Compute the unique hash for this entry.
// This is based on the current compiler version, the module itself, the
// export list, the hash for every single module in the import list, the
// list of ResolvedODR for the module, and the list of preserved symbols.
SHA1 Hasher;
// Start with the compiler revision
Hasher.update(LLVM_VERSION_STRING);
#ifdef HAVE_LLVM_REVISION
Hasher.update(LLVM_REVISION);
#endif
// Include the hash for the current module
auto ModHash = Index.getModuleHash(ModuleID);
Hasher.update(ArrayRef<uint8_t>((uint8_t *)&ModHash[0], sizeof(ModHash)));
for (auto F : ExportList)
// The export list can impact the internalization, be conservative here
Hasher.update(ArrayRef<uint8_t>((uint8_t *)&F, sizeof(F)));
// Include the hash for every module we import functions from
for (auto &Entry : ImportList) {
auto ModHash = Index.getModuleHash(Entry.first());
Hasher.update(ArrayRef<uint8_t>((uint8_t *)&ModHash[0], sizeof(ModHash)));
}
// Include the hash for the resolved ODR.
for (auto &Entry : ResolvedODR) {
Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&Entry.first,
sizeof(GlobalValue::GUID)));
Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&Entry.second,
sizeof(GlobalValue::LinkageTypes)));
}
// Include the hash for the linkage type to reflect internalization and weak
// resolution.
for (auto &GS : DefinedGlobals) {
GlobalValue::LinkageTypes Linkage = GS.second->linkage();
Hasher.update(
ArrayRef<uint8_t>((const uint8_t *)&Linkage, sizeof(Linkage)));
}
Key = toHex(Hasher.result());
}
// Simple helper to load a module from bitcode
std::unique_ptr<Module>
llvm::loadModuleFromBuffer(const MemoryBufferRef &Buffer, LLVMContext &Context,
bool Lazy) {
SMDiagnostic Err;
ErrorOr<std::unique_ptr<Module>> ModuleOrErr(nullptr);
if (Lazy) {
ModuleOrErr =
getLazyBitcodeModule(MemoryBuffer::getMemBuffer(Buffer, false), Context,
/* ShouldLazyLoadMetadata */ Lazy);
} else {
ModuleOrErr = parseBitcodeFile(Buffer, Context);
}
if (std::error_code EC = ModuleOrErr.getError()) {
Err = SMDiagnostic(Buffer.getBufferIdentifier(), SourceMgr::DK_Error,
EC.message());
Err.print("ThinLTO", errs());
report_fatal_error("Can't load module, abort.");
}
return std::move(ModuleOrErr.get());
}
static void thinLTOResolveWeakForLinkerGUID(
GlobalValueSummaryList &GVSummaryList, GlobalValue::GUID GUID,
DenseSet<GlobalValueSummary *> &GlobalInvolvedWithAlias,
function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)>
isPrevailing,
function_ref<void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)>
recordNewLinkage) {
for (auto &S : GVSummaryList) {
if (GlobalInvolvedWithAlias.count(S.get()))
continue;
GlobalValue::LinkageTypes OriginalLinkage = S->linkage();
if (!GlobalValue::isWeakForLinker(OriginalLinkage))
continue;
// We need to emit only one of these. The prevailing module will keep it,
// but turned into a weak, while the others will drop it when possible.
if (isPrevailing(GUID, S.get())) {
if (GlobalValue::isLinkOnceLinkage(OriginalLinkage))
S->setLinkage(GlobalValue::getWeakLinkage(
GlobalValue::isLinkOnceODRLinkage(OriginalLinkage)));
}
// Alias can't be turned into available_externally.
else if (!isa<AliasSummary>(S.get()) &&
(GlobalValue::isLinkOnceODRLinkage(OriginalLinkage) ||
GlobalValue::isWeakODRLinkage(OriginalLinkage)))
S->setLinkage(GlobalValue::AvailableExternallyLinkage);
if (S->linkage() != OriginalLinkage)
recordNewLinkage(S->modulePath(), GUID, S->linkage());
}
}
// Resolve Weak and LinkOnce values in the \p Index.
//
// We'd like to drop these functions if they are no longer referenced in the
// current module. However there is a chance that another module is still
// referencing them because of the import. We make sure we always emit at least
// one copy.
void llvm::thinLTOResolveWeakForLinkerInIndex(
ModuleSummaryIndex &Index,
function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)>
isPrevailing,
function_ref<void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)>
recordNewLinkage) {
// We won't optimize the globals that are referenced by an alias for now
// Ideally we should turn the alias into a global and duplicate the definition
// when needed.
DenseSet<GlobalValueSummary *> GlobalInvolvedWithAlias;
for (auto &I : Index)
for (auto &S : I.second)
if (auto AS = dyn_cast<AliasSummary>(S.get()))
GlobalInvolvedWithAlias.insert(&AS->getAliasee());
for (auto &I : Index)
thinLTOResolveWeakForLinkerGUID(I.second, I.first, GlobalInvolvedWithAlias,
isPrevailing, recordNewLinkage);
}
static void thinLTOInternalizeAndPromoteGUID(
GlobalValueSummaryList &GVSummaryList, GlobalValue::GUID GUID,
function_ref<bool(StringRef, GlobalValue::GUID)> isExported) {
for (auto &S : GVSummaryList) {
if (isExported(S->modulePath(), GUID)) {
if (GlobalValue::isLocalLinkage(S->linkage()))
S->setLinkage(GlobalValue::ExternalLinkage);
} else if (!GlobalValue::isLocalLinkage(S->linkage()))
S->setLinkage(GlobalValue::InternalLinkage);
}
}
// Update the linkages in the given \p Index to mark exported values
// as external and non-exported values as internal.
void llvm::thinLTOInternalizeAndPromoteInIndex(
ModuleSummaryIndex &Index,
function_ref<bool(StringRef, GlobalValue::GUID)> isExported) {
for (auto &I : Index)
thinLTOInternalizeAndPromoteGUID(I.second, I.first, isExported);
}
Expected<std::unique_ptr<InputFile>> InputFile::create(MemoryBufferRef Object) {
std::unique_ptr<InputFile> File(new InputFile);
std::string Msg;
auto DiagHandler = [](const DiagnosticInfo &DI, void *MsgP) {
auto *Msg = reinterpret_cast<std::string *>(MsgP);
raw_string_ostream OS(*Msg);
DiagnosticPrinterRawOStream DP(OS);
DI.print(DP);
};
File->Ctx.setDiagnosticHandler(DiagHandler, static_cast<void *>(&Msg));
ErrorOr<std::unique_ptr<object::IRObjectFile>> IRObj =
IRObjectFile::create(Object, File->Ctx);
if (!Msg.empty())
return make_error<StringError>(Msg, inconvertibleErrorCode());
if (!IRObj)
return errorCodeToError(IRObj.getError());
File->Obj = std::move(*IRObj);
File->Ctx.setDiagnosticHandler(nullptr, nullptr);
return std::move(File);
}
LTO::RegularLTOState::RegularLTOState(unsigned ParallelCodeGenParallelismLevel,
Config &Conf)
: ParallelCodeGenParallelismLevel(ParallelCodeGenParallelismLevel),
Ctx(Conf) {}
LTO::ThinLTOState::ThinLTOState(ThinBackend Backend) : Backend(Backend) {
if (!Backend)
this->Backend = createInProcessThinBackend(thread::hardware_concurrency());
}
LTO::LTO(Config Conf, ThinBackend Backend,
unsigned ParallelCodeGenParallelismLevel)
: Conf(std::move(Conf)),
RegularLTO(ParallelCodeGenParallelismLevel, this->Conf),
ThinLTO(std::move(Backend)) {}
// Add the given symbol to the GlobalResolutions map, and resolve its partition.
void LTO::addSymbolToGlobalRes(IRObjectFile *Obj,
SmallPtrSet<GlobalValue *, 8> &Used,
const InputFile::Symbol &Sym,
SymbolResolution Res, unsigned Partition) {
GlobalValue *GV = Obj->getSymbolGV(Sym.I->getRawDataRefImpl());
auto &GlobalRes = GlobalResolutions[Sym.getName()];
if (GV) {
GlobalRes.UnnamedAddr &= GV->hasGlobalUnnamedAddr();
if (Res.Prevailing)
GlobalRes.IRName = GV->getName();
}
if (Res.VisibleToRegularObj || (GV && Used.count(GV)) ||
(GlobalRes.Partition != GlobalResolution::Unknown &&
GlobalRes.Partition != Partition))
GlobalRes.Partition = GlobalResolution::External;
else
GlobalRes.Partition = Partition;
}
static void writeToResolutionFile(raw_ostream &OS, InputFile *Input,
ArrayRef<SymbolResolution> Res) {
StringRef Path = Input->getMemoryBufferRef().getBufferIdentifier();
OS << Path << '\n';
auto ResI = Res.begin();
for (const InputFile::Symbol &Sym : Input->symbols()) {
assert(ResI != Res.end());
SymbolResolution Res = *ResI++;
OS << "-r=" << Path << ',' << Sym.getName() << ',';
if (Res.Prevailing)
OS << 'p';
if (Res.FinalDefinitionInLinkageUnit)
OS << 'l';
if (Res.VisibleToRegularObj)
OS << 'x';
OS << '\n';
}
assert(ResI == Res.end());
}
Error LTO::add(std::unique_ptr<InputFile> Input,
ArrayRef<SymbolResolution> Res) {
assert(!CalledGetMaxTasks);
if (Conf.ResolutionFile)
writeToResolutionFile(*Conf.ResolutionFile, Input.get(), Res);
// FIXME: move to backend
Module &M = Input->Obj->getModule();
if (!Conf.OverrideTriple.empty())
M.setTargetTriple(Conf.OverrideTriple);
else if (M.getTargetTriple().empty())
M.setTargetTriple(Conf.DefaultTriple);
MemoryBufferRef MBRef = Input->Obj->getMemoryBufferRef();
bool HasThinLTOSummary = hasGlobalValueSummary(MBRef, Conf.DiagHandler);
if (HasThinLTOSummary)
return addThinLTO(std::move(Input), Res);
else
return addRegularLTO(std::move(Input), Res);
}
// Add a regular LTO object to the link.
Error LTO::addRegularLTO(std::unique_ptr<InputFile> Input,
ArrayRef<SymbolResolution> Res) {
if (!RegularLTO.CombinedModule) {
RegularLTO.CombinedModule =
llvm::make_unique<Module>("ld-temp.o", RegularLTO.Ctx);
RegularLTO.Mover = llvm::make_unique<IRMover>(*RegularLTO.CombinedModule);
}
ErrorOr<std::unique_ptr<object::IRObjectFile>> ObjOrErr =
IRObjectFile::create(Input->Obj->getMemoryBufferRef(), RegularLTO.Ctx);
if (!ObjOrErr)
return errorCodeToError(ObjOrErr.getError());
std::unique_ptr<object::IRObjectFile> Obj = std::move(*ObjOrErr);
Module &M = Obj->getModule();
M.materializeMetadata();
UpgradeDebugInfo(M);
SmallPtrSet<GlobalValue *, 8> Used;
collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false);
std::vector<GlobalValue *> Keep;
for (GlobalVariable &GV : M.globals())
if (GV.hasAppendingLinkage())
Keep.push_back(&GV);
auto ResI = Res.begin();
for (const InputFile::Symbol &Sym :
make_range(InputFile::symbol_iterator(Obj->symbol_begin()),
InputFile::symbol_iterator(Obj->symbol_end()))) {
assert(ResI != Res.end());
SymbolResolution Res = *ResI++;
addSymbolToGlobalRes(Obj.get(), Used, Sym, Res, 0);
GlobalValue *GV = Obj->getSymbolGV(Sym.I->getRawDataRefImpl());
if (Sym.getFlags() & object::BasicSymbolRef::SF_Undefined)
continue;
if (Res.Prevailing && GV) {
Keep.push_back(GV);
switch (GV->getLinkage()) {
default:
break;
case GlobalValue::LinkOnceAnyLinkage:
GV->setLinkage(GlobalValue::WeakAnyLinkage);
break;
case GlobalValue::LinkOnceODRLinkage:
GV->setLinkage(GlobalValue::WeakODRLinkage);
break;
}
}
// Common resolution: collect the maximum size/alignment over all commons.
// We also record if we see an instance of a common as prevailing, so that
// if none is prevailing we can ignore it later.
if (Sym.getFlags() & object::BasicSymbolRef::SF_Common) {
auto &CommonRes = RegularLTO.Commons[Sym.getIRName()];
CommonRes.Size = std::max(CommonRes.Size, Sym.getCommonSize());
CommonRes.Align = std::max(CommonRes.Align, Sym.getCommonAlignment());
CommonRes.Prevailing |= Res.Prevailing;
}
// FIXME: use proposed local attribute for FinalDefinitionInLinkageUnit.
}
assert(ResI == Res.end());
return RegularLTO.Mover->move(Obj->takeModule(), Keep,
[](GlobalValue &, IRMover::ValueAdder) {});
}
// Add a ThinLTO object to the link.
Error LTO::addThinLTO(std::unique_ptr<InputFile> Input,
ArrayRef<SymbolResolution> Res) {
Module &M = Input->Obj->getModule();
SmallPtrSet<GlobalValue *, 8> Used;
collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false);
MemoryBufferRef MBRef = Input->Obj->getMemoryBufferRef();
ErrorOr<std::unique_ptr<object::ModuleSummaryIndexObjectFile>>
SummaryObjOrErr =
object::ModuleSummaryIndexObjectFile::create(MBRef, Conf.DiagHandler);
if (!SummaryObjOrErr)
return errorCodeToError(SummaryObjOrErr.getError());
ThinLTO.CombinedIndex.mergeFrom((*SummaryObjOrErr)->takeIndex(),
ThinLTO.ModuleMap.size());
auto ResI = Res.begin();
for (const InputFile::Symbol &Sym : Input->symbols()) {
assert(ResI != Res.end());
SymbolResolution Res = *ResI++;
addSymbolToGlobalRes(Input->Obj.get(), Used, Sym, Res,
ThinLTO.ModuleMap.size() + 1);
GlobalValue *GV = Input->Obj->getSymbolGV(Sym.I->getRawDataRefImpl());
if (Res.Prevailing && GV)
ThinLTO.PrevailingModuleForGUID[GV->getGUID()] =
MBRef.getBufferIdentifier();
}
assert(ResI == Res.end());
ThinLTO.ModuleMap[MBRef.getBufferIdentifier()] = MBRef;
return Error();
}
unsigned LTO::getMaxTasks() const {
CalledGetMaxTasks = true;
return RegularLTO.ParallelCodeGenParallelismLevel + ThinLTO.ModuleMap.size();
}
Error LTO::run(AddOutputFn AddOutput) {
// Save the status of having a regularLTO combined module, as
// this is needed for generating the ThinLTO Task ID, and
// the CombinedModule will be moved at the end of runRegularLTO.
bool HasRegularLTO = RegularLTO.CombinedModule != nullptr;
// Invoke regular LTO if there was a regular LTO module to start with.
if (HasRegularLTO)
if (auto E = runRegularLTO(AddOutput))
return E;
return runThinLTO(AddOutput, HasRegularLTO);
}
Error LTO::runRegularLTO(AddOutputFn AddOutput) {
// Make sure commons have the right size/alignment: we kept the largest from
// all the prevailing when adding the inputs, and we apply it here.
const DataLayout &DL = RegularLTO.CombinedModule->getDataLayout();
for (auto &I : RegularLTO.Commons) {
if (!I.second.Prevailing)
// Don't do anything if no instance of this common was prevailing.
continue;
GlobalVariable *OldGV = RegularLTO.CombinedModule->getNamedGlobal(I.first);
if (OldGV && DL.getTypeAllocSize(OldGV->getValueType()) == I.second.Size) {
// Don't create a new global if the type is already correct, just make
// sure the alignment is correct.
OldGV->setAlignment(I.second.Align);
continue;
}
ArrayType *Ty =
ArrayType::get(Type::getInt8Ty(RegularLTO.Ctx), I.second.Size);
auto *GV = new GlobalVariable(*RegularLTO.CombinedModule, Ty, false,
GlobalValue::CommonLinkage,
ConstantAggregateZero::get(Ty), "");
GV->setAlignment(I.second.Align);
if (OldGV) {
OldGV->replaceAllUsesWith(ConstantExpr::getBitCast(GV, OldGV->getType()));
GV->takeName(OldGV);
OldGV->eraseFromParent();
} else {
GV->setName(I.first);
}
}
if (Conf.PreOptModuleHook &&
!Conf.PreOptModuleHook(0, *RegularLTO.CombinedModule))
return Error();
if (!Conf.CodeGenOnly) {
for (const auto &R : GlobalResolutions) {
if (R.second.IRName.empty())
continue;
if (R.second.Partition != 0 &&
R.second.Partition != GlobalResolution::External)
continue;
GlobalValue *GV =
RegularLTO.CombinedModule->getNamedValue(R.second.IRName);
// Ignore symbols defined in other partitions.
if (!GV || GV->hasLocalLinkage())
continue;
GV->setUnnamedAddr(R.second.UnnamedAddr ? GlobalValue::UnnamedAddr::Global
: GlobalValue::UnnamedAddr::None);
if (R.second.Partition == 0)
GV->setLinkage(GlobalValue::InternalLinkage);
}
if (Conf.PostInternalizeModuleHook &&
!Conf.PostInternalizeModuleHook(0, *RegularLTO.CombinedModule))
return Error();
}
return backend(Conf, AddOutput, RegularLTO.ParallelCodeGenParallelismLevel,
std::move(RegularLTO.CombinedModule));
}
/// This class defines the interface to the ThinLTO backend.
class lto::ThinBackendProc {
protected:
Config &Conf;
ModuleSummaryIndex &CombinedIndex;
const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries;
public:
ThinBackendProc(Config &Conf, ModuleSummaryIndex &CombinedIndex,
const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries)
: Conf(Conf), CombinedIndex(CombinedIndex),
ModuleToDefinedGVSummaries(ModuleToDefinedGVSummaries) {}
virtual ~ThinBackendProc() {}
virtual Error start(
unsigned Task, MemoryBufferRef MBRef,
const FunctionImporter::ImportMapTy &ImportList,
const FunctionImporter::ExportSetTy &ExportList,
const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
MapVector<StringRef, MemoryBufferRef> &ModuleMap) = 0;
virtual Error wait() = 0;
};
class InProcessThinBackend : public ThinBackendProc {
ThreadPool BackendThreadPool;
AddOutputFn AddOutput;
Optional<Error> Err;
std::mutex ErrMu;
public:
InProcessThinBackend(
Config &Conf, ModuleSummaryIndex &CombinedIndex,
unsigned ThinLTOParallelismLevel,
const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries,
AddOutputFn AddOutput)
: ThinBackendProc(Conf, CombinedIndex, ModuleToDefinedGVSummaries),
BackendThreadPool(ThinLTOParallelismLevel),
AddOutput(std::move(AddOutput)) {}
Error runThinLTOBackendThread(
AddOutputFn AddOutput, unsigned Task, MemoryBufferRef MBRef,
ModuleSummaryIndex &CombinedIndex,
const FunctionImporter::ImportMapTy &ImportList,
const FunctionImporter::ExportSetTy &ExportList,
const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
const GVSummaryMapTy &DefinedGlobals,
MapVector<StringRef, MemoryBufferRef> &ModuleMap) {
auto ModuleIdentifier = MBRef.getBufferIdentifier();
auto Output = AddOutput(Task);
if (Output->isCachingEnabled()) {
SmallString<40> Key;
// The module may be cached, this helps handling it.
computeCacheKey(Key, CombinedIndex, ModuleIdentifier, ImportList,
ExportList, ResolvedODR, DefinedGlobals);
if (Output->tryLoadFromCache(Key))
return Error();
}
LTOLLVMContext BackendContext(Conf);
ErrorOr<std::unique_ptr<Module>> MOrErr =
parseBitcodeFile(MBRef, BackendContext);
assert(MOrErr && "Unable to load module in thread?");
auto AddOutputWrapper = [&](unsigned TaskId) {
assert(Task == TaskId && "Unexpexted TaskId mismatch");
return std::move(Output);
};
return thinBackend(Conf, Task, AddOutputWrapper, **MOrErr, CombinedIndex,
ImportList, DefinedGlobals, ModuleMap);
}
Error start(
unsigned Task, MemoryBufferRef MBRef,
const FunctionImporter::ImportMapTy &ImportList,
const FunctionImporter::ExportSetTy &ExportList,
const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
MapVector<StringRef, MemoryBufferRef> &ModuleMap) override {
StringRef ModulePath = MBRef.getBufferIdentifier();
assert(ModuleToDefinedGVSummaries.count(ModulePath));
const GVSummaryMapTy &DefinedGlobals =
ModuleToDefinedGVSummaries.find(ModulePath)->second;
BackendThreadPool.async(
[=](MemoryBufferRef MBRef, ModuleSummaryIndex &CombinedIndex,
const FunctionImporter::ImportMapTy &ImportList,
const FunctionImporter::ExportSetTy &ExportList,
const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes>
&ResolvedODR,
const GVSummaryMapTy &DefinedGlobals,
MapVector<StringRef, MemoryBufferRef> &ModuleMap) {
Error E = runThinLTOBackendThread(
AddOutput, Task, MBRef, CombinedIndex, ImportList, ExportList,
ResolvedODR, DefinedGlobals, ModuleMap);
if (E) {
std::unique_lock<std::mutex> L(ErrMu);
if (Err)
Err = joinErrors(std::move(*Err), std::move(E));
else
Err = std::move(E);
}
},
MBRef, std::ref(CombinedIndex), std::ref(ImportList),
std::ref(ExportList), std::ref(ResolvedODR), std::ref(DefinedGlobals),
std::ref(ModuleMap));
return Error();
}
Error wait() override {
BackendThreadPool.wait();
if (Err)
return std::move(*Err);
else
return Error();
}
};
ThinBackend lto::createInProcessThinBackend(unsigned ParallelismLevel) {
return [=](Config &Conf, ModuleSummaryIndex &CombinedIndex,
const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries,
AddOutputFn AddOutput) {
return llvm::make_unique<InProcessThinBackend>(
Conf, CombinedIndex, ParallelismLevel, ModuleToDefinedGVSummaries,
AddOutput);
};
}
class WriteIndexesThinBackend : public ThinBackendProc {
std::string OldPrefix, NewPrefix;
bool ShouldEmitImportsFiles;
std::string LinkedObjectsFileName;
std::unique_ptr<llvm::raw_fd_ostream> LinkedObjectsFile;
public:
WriteIndexesThinBackend(
Config &Conf, ModuleSummaryIndex &CombinedIndex,
const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries,
std::string OldPrefix, std::string NewPrefix, bool ShouldEmitImportsFiles,
std::string LinkedObjectsFileName)
: ThinBackendProc(Conf, CombinedIndex, ModuleToDefinedGVSummaries),
OldPrefix(OldPrefix), NewPrefix(NewPrefix),
ShouldEmitImportsFiles(ShouldEmitImportsFiles),
LinkedObjectsFileName(LinkedObjectsFileName) {}
/// Given the original \p Path to an output file, replace any path
/// prefix matching \p OldPrefix with \p NewPrefix. Also, create the
/// resulting directory if it does not yet exist.
std::string getThinLTOOutputFile(const std::string &Path,
const std::string &OldPrefix,
const std::string &NewPrefix) {
if (OldPrefix.empty() && NewPrefix.empty())
return Path;
SmallString<128> NewPath(Path);
llvm::sys::path::replace_path_prefix(NewPath, OldPrefix, NewPrefix);
StringRef ParentPath = llvm::sys::path::parent_path(NewPath.str());
if (!ParentPath.empty()) {
// Make sure the new directory exists, creating it if necessary.
if (std::error_code EC = llvm::sys::fs::create_directories(ParentPath))
llvm::errs() << "warning: could not create directory '" << ParentPath
<< "': " << EC.message() << '\n';
}
return NewPath.str();
}
Error start(
unsigned Task, MemoryBufferRef MBRef,
const FunctionImporter::ImportMapTy &ImportList,
const FunctionImporter::ExportSetTy &ExportList,
const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
MapVector<StringRef, MemoryBufferRef> &ModuleMap) override {
StringRef ModulePath = MBRef.getBufferIdentifier();
std::string NewModulePath =
getThinLTOOutputFile(ModulePath, OldPrefix, NewPrefix);
std::error_code EC;
if (!LinkedObjectsFileName.empty()) {
if (!LinkedObjectsFile) {
LinkedObjectsFile = llvm::make_unique<raw_fd_ostream>(
LinkedObjectsFileName, EC, sys::fs::OpenFlags::F_None);
if (EC)
return errorCodeToError(EC);
}
*LinkedObjectsFile << NewModulePath << '\n';
}
std::map<std::string, GVSummaryMapTy> ModuleToSummariesForIndex;
gatherImportedSummariesForModule(ModulePath, ModuleToDefinedGVSummaries,
ImportList, ModuleToSummariesForIndex);
raw_fd_ostream OS(NewModulePath + ".thinlto.bc", EC,
sys::fs::OpenFlags::F_None);
if (EC)
return errorCodeToError(EC);
WriteIndexToFile(CombinedIndex, OS, &ModuleToSummariesForIndex);
if (ShouldEmitImportsFiles)
return errorCodeToError(
EmitImportsFiles(ModulePath, NewModulePath + ".imports", ImportList));
return Error();
}
Error wait() override { return Error(); }
};
ThinBackend lto::createWriteIndexesThinBackend(std::string OldPrefix,
std::string NewPrefix,
bool ShouldEmitImportsFiles,
std::string LinkedObjectsFile) {
return [=](Config &Conf, ModuleSummaryIndex &CombinedIndex,
const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries,
AddOutputFn AddOutput) {
return llvm::make_unique<WriteIndexesThinBackend>(
Conf, CombinedIndex, ModuleToDefinedGVSummaries, OldPrefix, NewPrefix,
ShouldEmitImportsFiles, LinkedObjectsFile);
};
}
Error LTO::runThinLTO(AddOutputFn AddOutput, bool HasRegularLTO) {
if (ThinLTO.ModuleMap.empty())
return Error();
if (Conf.CombinedIndexHook && !Conf.CombinedIndexHook(ThinLTO.CombinedIndex))
return Error();
// Collect for each module the list of function it defines (GUID ->
// Summary).
StringMap<std::map<GlobalValue::GUID, GlobalValueSummary *>>
ModuleToDefinedGVSummaries(ThinLTO.ModuleMap.size());
ThinLTO.CombinedIndex.collectDefinedGVSummariesPerModule(
ModuleToDefinedGVSummaries);
StringMap<FunctionImporter::ImportMapTy> ImportLists(
ThinLTO.ModuleMap.size());
StringMap<FunctionImporter::ExportSetTy> ExportLists(
ThinLTO.ModuleMap.size());
ComputeCrossModuleImport(ThinLTO.CombinedIndex, ModuleToDefinedGVSummaries,
ImportLists, ExportLists);
std::set<GlobalValue::GUID> ExportedGUIDs;
for (auto &Res : GlobalResolutions) {
if (!Res.second.IRName.empty() &&
Res.second.Partition == GlobalResolution::External)
ExportedGUIDs.insert(GlobalValue::getGUID(Res.second.IRName));
}
auto isPrevailing = [&](GlobalValue::GUID GUID, const GlobalValueSummary *S) {
return ThinLTO.PrevailingModuleForGUID[GUID] == S->modulePath();
};
auto isExported = [&](StringRef ModuleIdentifier, GlobalValue::GUID GUID) {
const auto &ExportList = ExportLists.find(ModuleIdentifier);
return (ExportList != ExportLists.end() &&
ExportList->second.count(GUID)) ||
ExportedGUIDs.count(GUID);
};
thinLTOInternalizeAndPromoteInIndex(ThinLTO.CombinedIndex, isExported);
StringMap<std::map<GlobalValue::GUID, GlobalValue::LinkageTypes>> ResolvedODR;
auto recordNewLinkage = [&](StringRef ModuleIdentifier,
GlobalValue::GUID GUID,
GlobalValue::LinkageTypes NewLinkage) {
ResolvedODR[ModuleIdentifier][GUID] = NewLinkage;
};
thinLTOResolveWeakForLinkerInIndex(ThinLTO.CombinedIndex, isPrevailing,
recordNewLinkage);
std::unique_ptr<ThinBackendProc> BackendProc = ThinLTO.Backend(
Conf, ThinLTO.CombinedIndex, ModuleToDefinedGVSummaries, AddOutput);
// Partition numbers for ThinLTO jobs start at 1 (see comments for
// GlobalResolution in LTO.h). Task numbers, however, start at
// ParallelCodeGenParallelismLevel if an LTO module is present, as tasks 0
// through ParallelCodeGenParallelismLevel-1 are reserved for parallel code
// generation partitions.
unsigned Task =
HasRegularLTO ? RegularLTO.ParallelCodeGenParallelismLevel : 0;
unsigned Partition = 1;
for (auto &Mod : ThinLTO.ModuleMap) {
if (Error E = BackendProc->start(Task, Mod.second, ImportLists[Mod.first],
ExportLists[Mod.first],
ResolvedODR[Mod.first], ThinLTO.ModuleMap))
return E;
++Task;
++Partition;
}
return BackendProc->wait();
}
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