LTOCodeGenerator.cpp [plain text]
#include "llvm/LTO/LTOCodeGenerator.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/Analysis/Passes.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/CodeGen/ParallelCG.h"
#include "llvm/CodeGen/RuntimeLibcalls.h"
#include "llvm/Config/config.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/DiagnosticPrinter.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/IR/Mangler.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Verifier.h"
#include "llvm/InitializePasses.h"
#include "llvm/LTO/LTOModule.h"
#include "llvm/Linker/Linker.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/ToolOutputFile.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetSubtargetInfo.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/IPO/PassManagerBuilder.h"
#include "llvm/Transforms/Utils/ModuleObfuscator.h"
#include "llvm/Transforms/ObjCARC.h"
#include <system_error>
using namespace llvm;
const char* LTOCodeGenerator::getVersionString() {
#ifdef LLVM_VERSION_INFO
#ifdef CLANG_VENDOR
return LLVM_VERSION_INFO;
#else
return PACKAGE_NAME " version " PACKAGE_VERSION ", " LLVM_VERSION_INFO;
#endif // CLANG_VENDOR
#else
return PACKAGE_NAME " version " PACKAGE_VERSION;
#endif
}
static void handleLTODiagnostic(const DiagnosticInfo &DI) {
DiagnosticPrinterRawOStream DP(errs());
DI.print(DP);
errs() << "\n";
}
LTOCodeGenerator::LTOCodeGenerator()
: Context(&getGlobalContext()),
MergedModule(new Module("ld-temp.o", *Context)),
IRLinker(MergedModule.get(), handleLTODiagnostic) {
initializeLTOPasses();
}
LTOCodeGenerator::LTOCodeGenerator(std::unique_ptr<LLVMContext> Context)
: OwnedContext(std::move(Context)), Context(OwnedContext.get()),
MergedModule(new Module("ld-temp.o", *OwnedContext)),
IRLinker(MergedModule.get(), handleLTODiagnostic) {
initializeLTOPasses();
}
LTOCodeGenerator::~LTOCodeGenerator() {}
void LTOCodeGenerator::initializeLTOPasses() {
PassRegistry &R = *PassRegistry::getPassRegistry();
initializeInternalizePassPass(R);
initializeIPSCCPPass(R);
initializeGlobalOptPass(R);
initializeConstantMergePass(R);
initializeDAHPass(R);
initializeInstructionCombiningPassPass(R);
initializeSimpleInlinerPass(R);
initializePruneEHPass(R);
initializeGlobalDCEPass(R);
initializeArgPromotionPass(R);
initializeJumpThreadingPass(R);
initializeSROALegacyPassPass(R);
initializeSROA_DTPass(R);
initializeSROA_SSAUpPass(R);
initializeFunctionAttrsPass(R);
initializeGlobalsAAWrapperPassPass(R);
initializeLICMPass(R);
initializeMergedLoadStoreMotionPass(R);
initializeGVNPass(R);
initializeMemCpyOptPass(R);
initializeDCEPass(R);
initializeCFGSimplifyPassPass(R);
}
bool LTOCodeGenerator::addModule(LTOModule *Mod) {
assert(&Mod->getModule().getContext() == Context &&
"Expected module in same context");
bool ret = IRLinker.linkInModule(&Mod->getModule());
const std::vector<const char *> &undefs = Mod->getAsmUndefinedRefs();
for (int i = 0, e = undefs.size(); i != e; ++i)
AsmUndefinedRefs[undefs[i]] = 1;
return !ret;
}
void LTOCodeGenerator::setModule(std::unique_ptr<LTOModule> Mod) {
assert(&Mod->getModule().getContext() == Context &&
"Expected module in same context");
AsmUndefinedRefs.clear();
MergedModule = Mod->takeModule();
IRLinker.setModule(MergedModule.get());
const std::vector<const char*> &Undefs = Mod->getAsmUndefinedRefs();
for (int I = 0, E = Undefs.size(); I != E; ++I)
AsmUndefinedRefs[Undefs[I]] = 1;
}
void LTOCodeGenerator::setTargetOptions(TargetOptions Options) {
this->Options = Options;
}
void LTOCodeGenerator::setDebugInfo(lto_debug_model Debug) {
switch (Debug) {
case LTO_DEBUG_MODEL_NONE:
EmitDwarfDebugInfo = false;
return;
case LTO_DEBUG_MODEL_DWARF:
EmitDwarfDebugInfo = true;
return;
}
llvm_unreachable("Unknown debug format!");
}
void LTOCodeGenerator::setOptLevel(unsigned Level) {
OptLevel = Level;
switch (OptLevel) {
case 0:
CGOptLevel = CodeGenOpt::None;
break;
case 1:
CGOptLevel = CodeGenOpt::Less;
break;
case 2:
CGOptLevel = CodeGenOpt::Default;
break;
case 3:
CGOptLevel = CodeGenOpt::Aggressive;
break;
}
}
bool LTOCodeGenerator::writeMergedModules(const char *Path,
std::string &ErrMsg) {
if (!determineTarget(ErrMsg))
return false;
applyScopeRestrictions();
std::error_code EC;
tool_output_file Out(Path, EC, sys::fs::F_None);
if (EC) {
ErrMsg = "could not open bitcode file for writing: ";
ErrMsg += Path;
return false;
}
WriteBitcodeToFile(MergedModule.get(), Out.os(), ShouldEmbedUselists);
Out.os().close();
if (Out.os().has_error()) {
ErrMsg = "could not write bitcode file: ";
ErrMsg += Path;
Out.os().clear_error();
return false;
}
Out.keep();
return true;
}
bool LTOCodeGenerator::compileOptimizedToFile(const char **Name,
std::string &ErrMsg) {
SmallString<128> Filename;
int FD;
std::error_code EC =
sys::fs::createTemporaryFile("lto-llvm", "o", FD, Filename);
if (EC) {
ErrMsg = EC.message();
return false;
}
tool_output_file objFile(Filename.c_str(), FD);
bool genResult = compileOptimized(&objFile.os(), ErrMsg);
objFile.os().close();
if (objFile.os().has_error()) {
objFile.os().clear_error();
sys::fs::remove(Twine(Filename));
return false;
}
objFile.keep();
if (!genResult) {
sys::fs::remove(Twine(Filename));
return false;
}
NativeObjectPath = Filename.c_str();
*Name = NativeObjectPath.c_str();
return true;
}
std::unique_ptr<MemoryBuffer>
LTOCodeGenerator::compileOptimized(std::string &ErrMsg) {
const char *name;
if (!compileOptimizedToFile(&name, ErrMsg))
return nullptr;
ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
MemoryBuffer::getFile(name, -1, false);
if (std::error_code EC = BufferOrErr.getError()) {
ErrMsg = EC.message();
sys::fs::remove(NativeObjectPath);
return nullptr;
}
sys::fs::remove(NativeObjectPath);
return std::move(*BufferOrErr);
}
bool LTOCodeGenerator::compile_to_file(const char **Name, bool DisableVerify,
bool DisableInline,
bool DisableGVNLoadPRE,
bool DisableVectorization,
std::string &ErrMsg) {
if (!optimize(DisableVerify, DisableInline, DisableGVNLoadPRE,
DisableVectorization, ErrMsg))
return false;
return compileOptimizedToFile(Name, ErrMsg);
}
std::unique_ptr<MemoryBuffer>
LTOCodeGenerator::compile(bool DisableVerify, bool DisableInline,
bool DisableGVNLoadPRE, bool DisableVectorization,
std::string &ErrMsg) {
if (!optimize(DisableVerify, DisableInline, DisableGVNLoadPRE,
DisableVectorization, ErrMsg))
return nullptr;
return compileOptimized(ErrMsg);
}
bool LTOCodeGenerator::determineTarget(std::string &ErrMsg) {
if (TargetMach)
return true;
std::string TripleStr = MergedModule->getTargetTriple();
if (TripleStr.empty()) {
TripleStr = sys::getDefaultTargetTriple();
MergedModule->setTargetTriple(TripleStr);
}
llvm::Triple Triple(TripleStr);
const Target *march = TargetRegistry::lookupTarget(TripleStr, ErrMsg);
if (!march)
return false;
SubtargetFeatures Features(MAttr);
Features.getDefaultSubtargetFeatures(Triple);
FeatureStr = Features.getString();
if (MCpu.empty() && Triple.isOSDarwin()) {
if (Triple.getArch() == llvm::Triple::x86_64)
MCpu = "core2";
else if (Triple.getArch() == llvm::Triple::x86)
MCpu = "yonah";
else if (Triple.getArch() == llvm::Triple::aarch64)
MCpu = "cyclone";
}
TargetMach.reset(march->createTargetMachine(TripleStr, MCpu, FeatureStr,
Options, RelocModel,
CodeModel::Default, CGOptLevel));
return true;
}
void LTOCodeGenerator::
applyRestriction(GlobalValue &GV,
ArrayRef<StringRef> Libcalls,
std::vector<const char*> &MustPreserveList,
SmallPtrSetImpl<GlobalValue*> &AsmUsed,
Mangler &Mangler) {
if (GV.isDeclaration())
return;
if (GV.hasPrivateLinkage())
return;
SmallString<64> Buffer;
TargetMach->getNameWithPrefix(Buffer, &GV, Mangler);
if (MustPreserveSymbols.count(Buffer))
MustPreserveList.push_back(GV.getName().data());
if (AsmUndefinedRefs.count(Buffer))
AsmUsed.insert(&GV);
if (isa<Function>(GV) &&
std::binary_search(Libcalls.begin(), Libcalls.end(), GV.getName()))
AsmUsed.insert(&GV);
}
static void findUsedValues(GlobalVariable *LLVMUsed,
SmallPtrSetImpl<GlobalValue*> &UsedValues) {
if (!LLVMUsed) return;
ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());
for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i)
if (GlobalValue *GV =
dyn_cast<GlobalValue>(Inits->getOperand(i)->stripPointerCasts()))
UsedValues.insert(GV);
}
static void accumulateAndSortLibcalls(std::vector<StringRef> &Libcalls,
const TargetLibraryInfo& TLI,
const Module &Mod,
const TargetMachine &TM) {
for (unsigned I = 0, E = static_cast<unsigned>(LibFunc::NumLibFuncs);
I != E; ++I) {
LibFunc::Func F = static_cast<LibFunc::Func>(I);
if (TLI.has(F))
Libcalls.push_back(TLI.getName(F));
}
SmallPtrSet<const TargetLowering *, 1> TLSet;
for (const Function &F : Mod) {
const TargetLowering *Lowering =
TM.getSubtargetImpl(F)->getTargetLowering();
if (Lowering && TLSet.insert(Lowering).second)
for (unsigned I = 0, E = static_cast<unsigned>(RTLIB::UNKNOWN_LIBCALL);
I != E; ++I)
if (const char *Name =
Lowering->getLibcallName(static_cast<RTLIB::Libcall>(I)))
Libcalls.push_back(Name);
}
array_pod_sort(Libcalls.begin(), Libcalls.end());
Libcalls.erase(std::unique(Libcalls.begin(), Libcalls.end()),
Libcalls.end());
}
void LTOCodeGenerator::applyScopeRestrictions() {
if (ScopeRestrictionsDone || !ShouldInternalize)
return;
legacy::PassManager passes;
passes.add(createVerifierPass());
Mangler Mangler;
std::vector<const char*> MustPreserveList;
SmallPtrSet<GlobalValue*, 8> AsmUsed;
std::vector<StringRef> Libcalls;
TargetLibraryInfoImpl TLII(Triple(TargetMach->getTargetTriple()));
TargetLibraryInfo TLI(TLII);
accumulateAndSortLibcalls(Libcalls, TLI, *MergedModule, *TargetMach);
for (Function &f : *MergedModule)
applyRestriction(f, Libcalls, MustPreserveList, AsmUsed, Mangler);
for (GlobalVariable &v : MergedModule->globals())
applyRestriction(v, Libcalls, MustPreserveList, AsmUsed, Mangler);
for (GlobalAlias &a : MergedModule->aliases())
applyRestriction(a, Libcalls, MustPreserveList, AsmUsed, Mangler);
GlobalVariable *LLVMCompilerUsed =
MergedModule->getGlobalVariable("llvm.compiler.used");
findUsedValues(LLVMCompilerUsed, AsmUsed);
if (LLVMCompilerUsed)
LLVMCompilerUsed->eraseFromParent();
if (!AsmUsed.empty()) {
llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(*Context);
std::vector<Constant*> asmUsed2;
for (auto *GV : AsmUsed) {
Constant *c = ConstantExpr::getBitCast(GV, i8PTy);
asmUsed2.push_back(c);
}
llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, asmUsed2.size());
LLVMCompilerUsed =
new llvm::GlobalVariable(*MergedModule, ATy, false,
llvm::GlobalValue::AppendingLinkage,
llvm::ConstantArray::get(ATy, asmUsed2),
"llvm.compiler.used");
LLVMCompilerUsed->setSection("llvm.metadata");
}
passes.add(createInternalizePass(MustPreserveList));
passes.run(*MergedModule);
ScopeRestrictionsDone = true;
}
bool LTOCodeGenerator::optimize(bool DisableVerify, bool DisableInline,
bool DisableGVNLoadPRE,
bool DisableVectorization,
std::string &ErrMsg) {
if (!this->determineTarget(ErrMsg))
return false;
this->applyScopeRestrictions();
legacy::PassManager passes;
MergedModule->setDataLayout(TargetMach->createDataLayout());
passes.add(
createTargetTransformInfoWrapperPass(TargetMach->getTargetIRAnalysis()));
Triple TargetTriple(TargetMach->getTargetTriple());
PassManagerBuilder PMB;
PMB.DisableGVNLoadPRE = DisableGVNLoadPRE;
PMB.LoopVectorize = !DisableVectorization;
PMB.SLPVectorize = !DisableVectorization;
if (!DisableInline)
PMB.Inliner = createFunctionInliningPass();
PMB.LibraryInfo = new TargetLibraryInfoImpl(TargetTriple);
PMB.OptLevel = OptLevel;
PMB.VerifyInput = !DisableVerify;
PMB.VerifyOutput = !DisableVerify;
PMB.populateLTOPassManager(passes);
passes.run(*MergedModule);
return true;
}
bool LTOCodeGenerator::compileOptimized(ArrayRef<raw_pwrite_stream *> Out,
std::string &ErrMsg) {
if (!this->determineTarget(ErrMsg))
return false;
legacy::PassManager preCodeGenPasses;
preCodeGenPasses.add(createObjCARCContractPass());
preCodeGenPasses.run(*MergedModule);
MergedModule =
splitCodeGen(std::move(MergedModule), Out, MCpu, FeatureStr, Options,
RelocModel, CodeModel::Default, CGOptLevel);
return true;
}
void LTOCodeGenerator::resetContext() {
assert(OwnedContext.get() != NULL && "Context must be owned by codegen");
MergedModule.reset();
OwnedContext.reset(new LLVMContext());
MergedModule.reset(new Module("ld-temp.o", *OwnedContext.get())),
Context = OwnedContext.get();
IRLinker = Linker(MergedModule.get());
}
bool LTOCodeGenerator::hideSymbols() {
std::string Err;
determineTarget(Err);
assert(TargetMach && "unable to determine target");
assert(IRLinker.getModule() && "not set up correctly");
convertDebugInfoToLineTables(*MergedModule);
StringMap<detail::DenseSetEmpty, BumpPtrAllocator &> Preserves(
IncrObfuscate.getAllocator());
StringMap<GlobalValue*, BumpPtrAllocator &> MangledValues(
IncrObfuscate.getAllocator());
Mangler Mangler;
auto tryAddPreserve = [&](GlobalValue &GV) {
if (GV.hasPrivateLinkage())
return;
SmallString<64> Buffer;
TargetMach->getNameWithPrefix(Buffer, &GV, Mangler);
if (MustPreserveSymbols.count(Buffer))
Preserves.insert({GV.getName(), {}});
else
MangledValues.insert({IncrObfuscate.copyString(Buffer), &GV});
};
Module *MergedModule = IRLinker.getModule();
for (auto &I : *MergedModule)
tryAddPreserve(I);
for (auto &I : MergedModule->globals())
tryAddPreserve(I);
for (auto &I : MergedModule->aliases())
tryAddPreserve(I);
obfuscateModule(*MergedModule, IncrObfuscate, Preserves);
if (!MangledNames) {
MangledNames.reset(new MangleNameMap(IncrObfuscate.getAllocator()));
}
for (auto &E : MangledValues) {
SmallString<64> Buffer;
TargetMach->getNameWithPrefix(Buffer, E.getValue(), Mangler);
MangledNames->insert({E.getKey(), IncrObfuscate.copyString(Buffer)});
}
return true;
}
const char* LTOCodeGenerator::lookupHiddenName(const char* SymbolName){
if (SymbolName == nullptr)
return nullptr;
if (MangledNames->count(SymbolName)) {
return MangledNames->lookup(SymbolName).data();
}
return nullptr;
}
bool LTOCodeGenerator::writeReverseMap(const char *Path) {
std::error_code EC;
tool_output_file Out(Path, EC, sys::fs::F_None);
if (EC) {
return false;
}
IncrObfuscate.writeReverseMap(Out.os());
Out.os().close();
if (Out.os().has_error()) {
Out.os().clear_error();
return false;
}
Out.keep();
return true;
}
void LTOCodeGenerator::setCodeGenDebugOptions(const char *Options) {
for (std::pair<StringRef, StringRef> o = getToken(Options); !o.first.empty();
o = getToken(o.second))
CodegenOptions.push_back(o.first);
}
void LTOCodeGenerator::parseCodeGenDebugOptions() {
if (!CodegenOptions.empty()) {
std::vector<const char *> CodegenArgv(1, "libLLVMLTO");
for (std::string &Arg : CodegenOptions)
CodegenArgv.push_back(Arg.c_str());
cl::ParseCommandLineOptions(CodegenArgv.size(), CodegenArgv.data());
}
}
void LTOCodeGenerator::DiagnosticHandler(const DiagnosticInfo &DI,
void *Context) {
((LTOCodeGenerator *)Context)->DiagnosticHandler2(DI);
}
void LTOCodeGenerator::DiagnosticHandler2(const DiagnosticInfo &DI) {
lto_codegen_diagnostic_severity_t Severity;
switch (DI.getSeverity()) {
case DS_Error:
Severity = LTO_DS_ERROR;
break;
case DS_Warning:
Severity = LTO_DS_WARNING;
break;
case DS_Remark:
Severity = LTO_DS_REMARK;
break;
case DS_Note:
Severity = LTO_DS_NOTE;
break;
}
std::string MsgStorage;
raw_string_ostream Stream(MsgStorage);
DiagnosticPrinterRawOStream DP(Stream);
DI.print(DP);
Stream.flush();
assert(DiagHandler && "Invalid diagnostic handler");
(*DiagHandler)(Severity, MsgStorage.c_str(), DiagContext);
}
void
LTOCodeGenerator::setDiagnosticHandler(lto_diagnostic_handler_t DiagHandler,
void *Ctxt) {
this->DiagHandler = DiagHandler;
this->DiagContext = Ctxt;
if (!DiagHandler)
return Context->setDiagnosticHandler(nullptr, nullptr);
Context->setDiagnosticHandler(LTOCodeGenerator::DiagnosticHandler, this,
true);
}