| //===-LTOCodeGenerator.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 the Link Time Optimization library. This library is |
| // intended to be used by linker to optimize code at link time. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "LTOModule.h" |
| #include "LTOCodeGenerator.h" |
| |
| |
| #include "llvm/Constants.h" |
| #include "llvm/DerivedTypes.h" |
| #include "llvm/Linker.h" |
| #include "llvm/LLVMContext.h" |
| #include "llvm/Module.h" |
| #include "llvm/ModuleProvider.h" |
| #include "llvm/PassManager.h" |
| #include "llvm/ADT/StringExtras.h" |
| #include "llvm/Analysis/Passes.h" |
| #include "llvm/Analysis/LoopPass.h" |
| #include "llvm/Analysis/Verifier.h" |
| #include "llvm/Bitcode/ReaderWriter.h" |
| #include "llvm/CodeGen/FileWriters.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/FormattedStream.h" |
| #include "llvm/Support/Mangler.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/StandardPasses.h" |
| #include "llvm/Support/SystemUtils.h" |
| #include "llvm/System/Signals.h" |
| #include "llvm/Target/SubtargetFeature.h" |
| #include "llvm/Target/TargetOptions.h" |
| #include "llvm/Target/TargetAsmInfo.h" |
| #include "llvm/Target/TargetData.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include "llvm/Target/TargetRegistry.h" |
| #include "llvm/Target/TargetSelect.h" |
| #include "llvm/Transforms/IPO.h" |
| #include "llvm/Transforms/Scalar.h" |
| #include "llvm/Config/config.h" |
| |
| |
| #include <cstdlib> |
| #include <fstream> |
| #include <unistd.h> |
| #include <fcntl.h> |
| |
| |
| using namespace llvm; |
| |
| static cl::opt<bool> DisableInline("disable-inlining", |
| cl::desc("Do not run the inliner pass")); |
| |
| |
| const char* LTOCodeGenerator::getVersionString() |
| { |
| #ifdef LLVM_VERSION_INFO |
| return PACKAGE_NAME " version " PACKAGE_VERSION ", " LLVM_VERSION_INFO; |
| #else |
| return PACKAGE_NAME " version " PACKAGE_VERSION; |
| #endif |
| } |
| |
| |
| LTOCodeGenerator::LTOCodeGenerator() |
| : _context(getGlobalContext()), |
| _linker("LinkTimeOptimizer", "ld-temp.o", _context), _target(NULL), |
| _emitDwarfDebugInfo(false), _scopeRestrictionsDone(false), |
| _codeModel(LTO_CODEGEN_PIC_MODEL_DYNAMIC), |
| _nativeObjectFile(NULL), _gccPath(NULL), _assemblerPath(NULL) |
| { |
| InitializeAllTargets(); |
| InitializeAllAsmPrinters(); |
| |
| } |
| |
| LTOCodeGenerator::~LTOCodeGenerator() |
| { |
| delete _target; |
| delete _nativeObjectFile; |
| } |
| |
| |
| |
| bool LTOCodeGenerator::addModule(LTOModule* mod, std::string& errMsg) |
| { |
| return _linker.LinkInModule(mod->getLLVVMModule(), &errMsg); |
| } |
| |
| |
| bool LTOCodeGenerator::setDebugInfo(lto_debug_model debug, std::string& errMsg) |
| { |
| switch (debug) { |
| case LTO_DEBUG_MODEL_NONE: |
| _emitDwarfDebugInfo = false; |
| return false; |
| |
| case LTO_DEBUG_MODEL_DWARF: |
| _emitDwarfDebugInfo = true; |
| return false; |
| } |
| errMsg = "unknown debug format"; |
| return true; |
| } |
| |
| |
| bool LTOCodeGenerator::setCodePICModel(lto_codegen_model model, |
| std::string& errMsg) |
| { |
| switch (model) { |
| case LTO_CODEGEN_PIC_MODEL_STATIC: |
| case LTO_CODEGEN_PIC_MODEL_DYNAMIC: |
| case LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC: |
| _codeModel = model; |
| return false; |
| } |
| errMsg = "unknown pic model"; |
| return true; |
| } |
| |
| void LTOCodeGenerator::setGccPath(const char* path) |
| { |
| if ( _gccPath ) |
| delete _gccPath; |
| _gccPath = new sys::Path(path); |
| } |
| |
| void LTOCodeGenerator::setAssemblerPath(const char* path) |
| { |
| if ( _assemblerPath ) |
| delete _assemblerPath; |
| _assemblerPath = new sys::Path(path); |
| } |
| |
| void LTOCodeGenerator::addMustPreserveSymbol(const char* sym) |
| { |
| _mustPreserveSymbols[sym] = 1; |
| } |
| |
| |
| bool LTOCodeGenerator::writeMergedModules(const char* path, std::string& errMsg) |
| { |
| if ( this->determineTarget(errMsg) ) |
| return true; |
| |
| // mark which symbols can not be internalized |
| this->applyScopeRestrictions(); |
| |
| // create output file |
| std::ofstream out(path, std::ios_base::out|std::ios::trunc|std::ios::binary); |
| if ( out.fail() ) { |
| errMsg = "could not open bitcode file for writing: "; |
| errMsg += path; |
| return true; |
| } |
| |
| // write bitcode to it |
| WriteBitcodeToFile(_linker.getModule(), out); |
| if ( out.fail() ) { |
| errMsg = "could not write bitcode file: "; |
| errMsg += path; |
| return true; |
| } |
| |
| return false; |
| } |
| |
| |
| const void* LTOCodeGenerator::compile(size_t* length, std::string& errMsg) |
| { |
| // make unique temp .s file to put generated assembly code |
| sys::Path uniqueAsmPath("lto-llvm.s"); |
| if ( uniqueAsmPath.createTemporaryFileOnDisk(true, &errMsg) ) |
| return NULL; |
| sys::RemoveFileOnSignal(uniqueAsmPath); |
| |
| // generate assembly code |
| bool genResult = false; |
| { |
| raw_fd_ostream asmFD(raw_fd_ostream(uniqueAsmPath.c_str(), |
| /*Binary=*/false, /*Force=*/true, |
| errMsg)); |
| formatted_raw_ostream asmFile(asmFD); |
| if (!errMsg.empty()) |
| return NULL; |
| genResult = this->generateAssemblyCode(asmFile, errMsg); |
| } |
| if ( genResult ) { |
| if ( uniqueAsmPath.exists() ) |
| uniqueAsmPath.eraseFromDisk(); |
| return NULL; |
| } |
| |
| // make unique temp .o file to put generated object file |
| sys::PathWithStatus uniqueObjPath("lto-llvm.o"); |
| if ( uniqueObjPath.createTemporaryFileOnDisk(true, &errMsg) ) { |
| if ( uniqueAsmPath.exists() ) |
| uniqueAsmPath.eraseFromDisk(); |
| return NULL; |
| } |
| sys::RemoveFileOnSignal(uniqueObjPath); |
| |
| // assemble the assembly code |
| const std::string& uniqueObjStr = uniqueObjPath.toString(); |
| bool asmResult = this->assemble(uniqueAsmPath.toString(), |
| uniqueObjStr, errMsg); |
| if ( !asmResult ) { |
| // remove old buffer if compile() called twice |
| delete _nativeObjectFile; |
| |
| // read .o file into memory buffer |
| _nativeObjectFile = MemoryBuffer::getFile(uniqueObjStr.c_str(),&errMsg); |
| } |
| |
| // remove temp files |
| uniqueAsmPath.eraseFromDisk(); |
| uniqueObjPath.eraseFromDisk(); |
| |
| // return buffer, unless error |
| if ( _nativeObjectFile == NULL ) |
| return NULL; |
| *length = _nativeObjectFile->getBufferSize(); |
| return _nativeObjectFile->getBufferStart(); |
| } |
| |
| |
| bool LTOCodeGenerator::assemble(const std::string& asmPath, |
| const std::string& objPath, std::string& errMsg) |
| { |
| sys::Path tool; |
| bool needsCompilerOptions = true; |
| if ( _assemblerPath ) { |
| tool = *_assemblerPath; |
| needsCompilerOptions = false; |
| } |
| else if ( _gccPath ) { |
| tool = *_gccPath; |
| } else { |
| // find compiler driver |
| tool = sys::Program::FindProgramByName("gcc"); |
| if ( tool.isEmpty() ) { |
| errMsg = "can't locate gcc"; |
| return true; |
| } |
| } |
| |
| // build argument list |
| std::vector<const char*> args; |
| std::string targetTriple = _linker.getModule()->getTargetTriple(); |
| args.push_back(tool.c_str()); |
| if ( targetTriple.find("darwin") != std::string::npos ) { |
| // darwin specific command line options |
| if (strncmp(targetTriple.c_str(), "i386-apple-", 11) == 0) { |
| args.push_back("-arch"); |
| args.push_back("i386"); |
| } |
| else if (strncmp(targetTriple.c_str(), "x86_64-apple-", 13) == 0) { |
| args.push_back("-arch"); |
| args.push_back("x86_64"); |
| } |
| else if (strncmp(targetTriple.c_str(), "powerpc-apple-", 14) == 0) { |
| args.push_back("-arch"); |
| args.push_back("ppc"); |
| } |
| else if (strncmp(targetTriple.c_str(), "powerpc64-apple-", 16) == 0) { |
| args.push_back("-arch"); |
| args.push_back("ppc64"); |
| } |
| else if (strncmp(targetTriple.c_str(), "arm-apple-", 10) == 0) { |
| args.push_back("-arch"); |
| args.push_back("arm"); |
| } |
| else if ((strncmp(targetTriple.c_str(), "armv4t-apple-", 13) == 0) || |
| (strncmp(targetTriple.c_str(), "thumbv4t-apple-", 15) == 0)) { |
| args.push_back("-arch"); |
| args.push_back("armv4t"); |
| } |
| else if ((strncmp(targetTriple.c_str(), "armv5-apple-", 12) == 0) || |
| (strncmp(targetTriple.c_str(), "armv5e-apple-", 13) == 0) || |
| (strncmp(targetTriple.c_str(), "thumbv5-apple-", 14) == 0) || |
| (strncmp(targetTriple.c_str(), "thumbv5e-apple-", 15) == 0)) { |
| args.push_back("-arch"); |
| args.push_back("armv5"); |
| } |
| else if ((strncmp(targetTriple.c_str(), "armv6-apple-", 12) == 0) || |
| (strncmp(targetTriple.c_str(), "thumbv6-apple-", 14) == 0)) { |
| args.push_back("-arch"); |
| args.push_back("armv6"); |
| } |
| else if ((strncmp(targetTriple.c_str(), "armv7-apple-", 12) == 0) || |
| (strncmp(targetTriple.c_str(), "thumbv7-apple-", 14) == 0)) { |
| args.push_back("-arch"); |
| args.push_back("armv7"); |
| } |
| // add -static to assembler command line when code model requires |
| if ( (_assemblerPath != NULL) && (_codeModel == LTO_CODEGEN_PIC_MODEL_STATIC) ) |
| args.push_back("-static"); |
| } |
| if ( needsCompilerOptions ) { |
| args.push_back("-c"); |
| args.push_back("-x"); |
| args.push_back("assembler"); |
| } |
| args.push_back("-o"); |
| args.push_back(objPath.c_str()); |
| args.push_back(asmPath.c_str()); |
| args.push_back(0); |
| |
| // invoke assembler |
| if ( sys::Program::ExecuteAndWait(tool, &args[0], 0, 0, 0, 0, &errMsg) ) { |
| errMsg = "error in assembly"; |
| return true; |
| } |
| return false; // success |
| } |
| |
| |
| |
| bool LTOCodeGenerator::determineTarget(std::string& errMsg) |
| { |
| if ( _target == NULL ) { |
| // create target machine from info for merged modules |
| Module* mergedModule = _linker.getModule(); |
| const Target *march = |
| TargetRegistry::lookupTarget(mergedModule->getTargetTriple(), |
| /*FallbackToHost=*/true, |
| /*RequireJIT=*/false, |
| errMsg); |
| if ( march == NULL ) |
| return true; |
| |
| // The relocation model is actually a static member of TargetMachine |
| // and needs to be set before the TargetMachine is instantiated. |
| switch( _codeModel ) { |
| case LTO_CODEGEN_PIC_MODEL_STATIC: |
| TargetMachine::setRelocationModel(Reloc::Static); |
| break; |
| case LTO_CODEGEN_PIC_MODEL_DYNAMIC: |
| TargetMachine::setRelocationModel(Reloc::PIC_); |
| break; |
| case LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC: |
| TargetMachine::setRelocationModel(Reloc::DynamicNoPIC); |
| break; |
| } |
| |
| // construct LTModule, hand over ownership of module and target |
| std::string FeatureStr = |
| getFeatureString(_linker.getModule()->getTargetTriple().c_str()); |
| _target = march->createTargetMachine(*mergedModule, FeatureStr.c_str()); |
| } |
| return false; |
| } |
| |
| void LTOCodeGenerator::applyScopeRestrictions() |
| { |
| if ( !_scopeRestrictionsDone ) { |
| Module* mergedModule = _linker.getModule(); |
| |
| // Start off with a verification pass. |
| PassManager passes; |
| passes.add(createVerifierPass()); |
| |
| // mark which symbols can not be internalized |
| if ( !_mustPreserveSymbols.empty() ) { |
| Mangler mangler(*mergedModule, |
| _target->getTargetAsmInfo()->getGlobalPrefix()); |
| std::vector<const char*> mustPreserveList; |
| for (Module::iterator f = mergedModule->begin(), |
| e = mergedModule->end(); f != e; ++f) { |
| if ( !f->isDeclaration() |
| && _mustPreserveSymbols.count(mangler.getMangledName(f)) ) |
| mustPreserveList.push_back(::strdup(f->getNameStr().c_str())); |
| } |
| for (Module::global_iterator v = mergedModule->global_begin(), |
| e = mergedModule->global_end(); v != e; ++v) { |
| if ( !v->isDeclaration() |
| && _mustPreserveSymbols.count(mangler.getMangledName(v)) ) |
| mustPreserveList.push_back(::strdup(v->getNameStr().c_str())); |
| } |
| passes.add(createInternalizePass(mustPreserveList)); |
| } |
| // apply scope restrictions |
| passes.run(*mergedModule); |
| |
| _scopeRestrictionsDone = true; |
| } |
| } |
| |
| /// Optimize merged modules using various IPO passes |
| bool LTOCodeGenerator::generateAssemblyCode(formatted_raw_ostream& out, |
| std::string& errMsg) |
| { |
| if ( this->determineTarget(errMsg) ) |
| return true; |
| |
| // mark which symbols can not be internalized |
| this->applyScopeRestrictions(); |
| |
| Module* mergedModule = _linker.getModule(); |
| |
| // If target supports exception handling then enable it now. |
| if ( _target->getTargetAsmInfo()->doesSupportExceptionHandling() ) |
| llvm::ExceptionHandling = true; |
| |
| // if options were requested, set them |
| if ( !_codegenOptions.empty() ) |
| cl::ParseCommandLineOptions(_codegenOptions.size(), |
| (char**)&_codegenOptions[0]); |
| |
| // Instantiate the pass manager to organize the passes. |
| PassManager passes; |
| |
| // Start off with a verification pass. |
| passes.add(createVerifierPass()); |
| |
| // Add an appropriate TargetData instance for this module... |
| passes.add(new TargetData(*_target->getTargetData())); |
| |
| createStandardLTOPasses(&passes, /*Internalize=*/ false, !DisableInline, |
| /*VerifyEach=*/ false); |
| |
| // Make sure everything is still good. |
| passes.add(createVerifierPass()); |
| |
| FunctionPassManager* codeGenPasses = |
| new FunctionPassManager(new ExistingModuleProvider(mergedModule)); |
| |
| codeGenPasses->add(new TargetData(*_target->getTargetData())); |
| |
| ObjectCodeEmitter* oce = NULL; |
| |
| switch (_target->addPassesToEmitFile(*codeGenPasses, out, |
| TargetMachine::AssemblyFile, |
| CodeGenOpt::Aggressive)) { |
| case FileModel::MachOFile: |
| oce = AddMachOWriter(*codeGenPasses, out, *_target); |
| break; |
| case FileModel::ElfFile: |
| oce = AddELFWriter(*codeGenPasses, out, *_target); |
| break; |
| case FileModel::AsmFile: |
| break; |
| case FileModel::Error: |
| case FileModel::None: |
| errMsg = "target file type not supported"; |
| return true; |
| } |
| |
| if (_target->addPassesToEmitFileFinish(*codeGenPasses, oce, |
| CodeGenOpt::Aggressive)) { |
| errMsg = "target does not support generation of this file type"; |
| return true; |
| } |
| |
| // Run our queue of passes all at once now, efficiently. |
| passes.run(*mergedModule); |
| |
| // Run the code generator, and write assembly file |
| codeGenPasses->doInitialization(); |
| |
| for (Module::iterator |
| it = mergedModule->begin(), e = mergedModule->end(); it != e; ++it) |
| if (!it->isDeclaration()) |
| codeGenPasses->run(*it); |
| |
| codeGenPasses->doFinalization(); |
| return false; // success |
| } |
| |
| |
| /// Optimize merged modules using various IPO passes |
| void LTOCodeGenerator::setCodeGenDebugOptions(const char* options) |
| { |
| std::string ops(options); |
| for (std::string o = getToken(ops); !o.empty(); o = getToken(ops)) { |
| // ParseCommandLineOptions() expects argv[0] to be program name. |
| // Lazily add that. |
| if ( _codegenOptions.empty() ) |
| _codegenOptions.push_back("libLTO"); |
| _codegenOptions.push_back(strdup(o.c_str())); |
| } |
| } |