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-rw-r--r--contrib/llvm/lib/LTO/LTOCodeGenerator.cpp600
-rw-r--r--contrib/llvm/lib/LTO/LTOModule.cpp658
2 files changed, 1258 insertions, 0 deletions
diff --git a/contrib/llvm/lib/LTO/LTOCodeGenerator.cpp b/contrib/llvm/lib/LTO/LTOCodeGenerator.cpp
new file mode 100644
index 0000000..6baaaa4
--- /dev/null
+++ b/contrib/llvm/lib/LTO/LTOCodeGenerator.cpp
@@ -0,0 +1,600 @@
+//===-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 "llvm/LTO/LTOCodeGenerator.h"
+#include "llvm/ADT/StringExtras.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/ObjCARC.h"
+#include <system_error>
+using namespace llvm;
+
+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(LLVMContext &Context)
+ : Context(Context), MergedModule(new Module("ld-temp.o", Context)),
+ TheLinker(new Linker(*MergedModule)) {
+ initializeLTOPasses();
+}
+
+LTOCodeGenerator::~LTOCodeGenerator() {}
+
+// Initialize LTO passes. Please keep this function in sync with
+// PassManagerBuilder::populateLTOPassManager(), and make sure all LTO
+// passes are initialized.
+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 = TheLinker->linkInModule(Mod->takeModule());
+
+ 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();
+ TheLinker = make_unique<Linker>(*MergedModule);
+
+ 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) {
+ if (!determineTarget())
+ return false;
+
+ // mark which symbols can not be internalized
+ applyScopeRestrictions();
+
+ // create output file
+ std::error_code EC;
+ tool_output_file Out(Path, EC, sys::fs::F_None);
+ if (EC) {
+ std::string ErrMsg = "could not open bitcode file for writing: ";
+ ErrMsg += Path;
+ emitError(ErrMsg);
+ return false;
+ }
+
+ // write bitcode to it
+ WriteBitcodeToFile(MergedModule.get(), Out.os(), ShouldEmbedUselists);
+ Out.os().close();
+
+ if (Out.os().has_error()) {
+ std::string ErrMsg = "could not write bitcode file: ";
+ ErrMsg += Path;
+ emitError(ErrMsg);
+ Out.os().clear_error();
+ return false;
+ }
+
+ Out.keep();
+ return true;
+}
+
+bool LTOCodeGenerator::compileOptimizedToFile(const char **Name) {
+ // make unique temp output file to put generated code
+ SmallString<128> Filename;
+ int FD;
+
+ const char *Extension =
+ (FileType == TargetMachine::CGFT_AssemblyFile ? "s" : "o");
+
+ std::error_code EC =
+ sys::fs::createTemporaryFile("lto-llvm", Extension, FD, Filename);
+ if (EC) {
+ emitError(EC.message());
+ return false;
+ }
+
+ // generate object file
+ tool_output_file objFile(Filename.c_str(), FD);
+
+ bool genResult = compileOptimized(&objFile.os());
+ 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() {
+ const char *name;
+ if (!compileOptimizedToFile(&name))
+ return nullptr;
+
+ // read .o file into memory buffer
+ ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
+ MemoryBuffer::getFile(name, -1, false);
+ if (std::error_code EC = BufferOrErr.getError()) {
+ emitError(EC.message());
+ sys::fs::remove(NativeObjectPath);
+ return nullptr;
+ }
+
+ // remove temp files
+ sys::fs::remove(NativeObjectPath);
+
+ return std::move(*BufferOrErr);
+}
+
+bool LTOCodeGenerator::compile_to_file(const char **Name, bool DisableVerify,
+ bool DisableInline,
+ bool DisableGVNLoadPRE,
+ bool DisableVectorization) {
+ if (!optimize(DisableVerify, DisableInline, DisableGVNLoadPRE,
+ DisableVectorization))
+ return false;
+
+ return compileOptimizedToFile(Name);
+}
+
+std::unique_ptr<MemoryBuffer>
+LTOCodeGenerator::compile(bool DisableVerify, bool DisableInline,
+ bool DisableGVNLoadPRE, bool DisableVectorization) {
+ if (!optimize(DisableVerify, DisableInline, DisableGVNLoadPRE,
+ DisableVectorization))
+ return nullptr;
+
+ return compileOptimized();
+}
+
+bool LTOCodeGenerator::determineTarget() {
+ if (TargetMach)
+ return true;
+
+ std::string TripleStr = MergedModule->getTargetTriple();
+ if (TripleStr.empty()) {
+ TripleStr = sys::getDefaultTargetTriple();
+ MergedModule->setTargetTriple(TripleStr);
+ }
+ llvm::Triple Triple(TripleStr);
+
+ // create target machine from info for merged modules
+ std::string ErrMsg;
+ const Target *march = TargetRegistry::lookupTarget(TripleStr, ErrMsg);
+ if (!march) {
+ emitError(ErrMsg);
+ return false;
+ }
+
+ // Construct LTOModule, hand over ownership of module and target. Use MAttr as
+ // the default set of features.
+ SubtargetFeatures Features(MAttr);
+ Features.getDefaultSubtargetFeatures(Triple);
+ FeatureStr = Features.getString();
+ // Set a default CPU for Darwin triples.
+ 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) {
+ // There are no restrictions to apply to declarations.
+ if (GV.isDeclaration())
+ return;
+
+ // There is nothing more restrictive than private linkage.
+ 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);
+
+ // Conservatively append user-supplied runtime library functions to
+ // llvm.compiler.used. These could be internalized and deleted by
+ // optimizations like -globalopt, causing problems when later optimizations
+ // add new library calls (e.g., llvm.memset => memset and printf => puts).
+ // Leave it to the linker to remove any dead code (e.g. with -dead_strip).
+ 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);
+}
+
+// Collect names of runtime library functions. User-defined functions with the
+// same names are added to llvm.compiler.used to prevent them from being
+// deleted by optimizations.
+static void accumulateAndSortLibcalls(std::vector<StringRef> &Libcalls,
+ const TargetLibraryInfo& TLI,
+ const Module &Mod,
+ const TargetMachine &TM) {
+ // TargetLibraryInfo has info on C runtime library calls on the current
+ // target.
+ 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)
+ // TargetLowering has info on library calls that CodeGen expects to be
+ // available, both from the C runtime and compiler-rt.
+ 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;
+
+ // Start off with a verification pass.
+ legacy::PassManager passes;
+ passes.add(createVerifierPass());
+
+ // mark which symbols can not be internalized
+ 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));
+
+ // apply scope restrictions
+ passes.run(*MergedModule);
+
+ ScopeRestrictionsDone = true;
+}
+
+/// Optimize merged modules using various IPO passes
+bool LTOCodeGenerator::optimize(bool DisableVerify, bool DisableInline,
+ bool DisableGVNLoadPRE,
+ bool DisableVectorization) {
+ if (!this->determineTarget())
+ return false;
+
+ // Mark which symbols can not be internalized
+ this->applyScopeRestrictions();
+
+ // Instantiate the pass manager to organize the passes.
+ legacy::PassManager passes;
+
+ // Add an appropriate DataLayout instance for this module...
+ 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);
+
+ // Run our queue of passes all at once now, efficiently.
+ passes.run(*MergedModule);
+
+ return true;
+}
+
+bool LTOCodeGenerator::compileOptimized(ArrayRef<raw_pwrite_stream *> Out) {
+ if (!this->determineTarget())
+ return false;
+
+ legacy::PassManager preCodeGenPasses;
+
+ // If the bitcode files contain ARC code and were compiled with optimization,
+ // the ObjCARCContractPass must be run, so do it unconditionally here.
+ preCodeGenPasses.add(createObjCARCContractPass());
+ preCodeGenPasses.run(*MergedModule);
+
+ // Do code generation. We need to preserve the module in case the client calls
+ // writeMergedModules() after compilation, but we only need to allow this at
+ // parallelism level 1. This is achieved by having splitCodeGen return the
+ // original module at parallelism level 1 which we then assign back to
+ // MergedModule.
+ MergedModule =
+ splitCodeGen(std::move(MergedModule), Out, MCpu, FeatureStr, Options,
+ RelocModel, CodeModel::Default, CGOptLevel, FileType);
+
+ return true;
+}
+
+/// setCodeGenDebugOptions - Set codegen debugging options to aid in debugging
+/// LTO problems.
+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 options were requested, set them
+ if (!CodegenOptions.empty()) {
+ // ParseCommandLineOptions() expects argv[0] to be program name.
+ 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) {
+ // Map the LLVM internal diagnostic severity to the LTO diagnostic severity.
+ 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;
+ }
+ // Create the string that will be reported to the external diagnostic handler.
+ std::string MsgStorage;
+ raw_string_ostream Stream(MsgStorage);
+ DiagnosticPrinterRawOStream DP(Stream);
+ DI.print(DP);
+ Stream.flush();
+
+ // If this method has been called it means someone has set up an external
+ // diagnostic handler. Assert on that.
+ 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);
+ // Register the LTOCodeGenerator stub in the LLVMContext to forward the
+ // diagnostic to the external DiagHandler.
+ Context.setDiagnosticHandler(LTOCodeGenerator::DiagnosticHandler, this,
+ /* RespectFilters */ true);
+}
+
+namespace {
+class LTODiagnosticInfo : public DiagnosticInfo {
+ const Twine &Msg;
+public:
+ LTODiagnosticInfo(const Twine &DiagMsg, DiagnosticSeverity Severity=DS_Error)
+ : DiagnosticInfo(DK_Linker, Severity), Msg(DiagMsg) {}
+ void print(DiagnosticPrinter &DP) const override { DP << Msg; }
+};
+}
+
+void LTOCodeGenerator::emitError(const std::string &ErrMsg) {
+ if (DiagHandler)
+ (*DiagHandler)(LTO_DS_ERROR, ErrMsg.c_str(), DiagContext);
+ else
+ Context.diagnose(LTODiagnosticInfo(ErrMsg));
+}
diff --git a/contrib/llvm/lib/LTO/LTOModule.cpp b/contrib/llvm/lib/LTO/LTOModule.cpp
new file mode 100644
index 0000000..409b949
--- /dev/null
+++ b/contrib/llvm/lib/LTO/LTOModule.cpp
@@ -0,0 +1,658 @@
+//===-- LTOModule.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 "llvm/LTO/LTOModule.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/CodeGen/Analysis.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DiagnosticPrinter.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Mangler.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/IR/Module.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCParser/MCAsmParser.h"
+#include "llvm/MC/MCSection.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/MC/MCTargetAsmParser.h"
+#include "llvm/MC/SubtargetFeature.h"
+#include "llvm/Object/IRObjectFile.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Target/TargetLowering.h"
+#include "llvm/Target/TargetLoweringObjectFile.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
+#include "llvm/Transforms/Utils/GlobalStatus.h"
+#include <system_error>
+using namespace llvm;
+using namespace llvm::object;
+
+LTOModule::LTOModule(std::unique_ptr<object::IRObjectFile> Obj,
+ llvm::TargetMachine *TM)
+ : IRFile(std::move(Obj)), _target(TM) {}
+
+LTOModule::LTOModule(std::unique_ptr<object::IRObjectFile> Obj,
+ llvm::TargetMachine *TM,
+ std::unique_ptr<LLVMContext> Context)
+ : OwnedContext(std::move(Context)), IRFile(std::move(Obj)), _target(TM) {}
+
+LTOModule::~LTOModule() {}
+
+/// isBitcodeFile - Returns 'true' if the file (or memory contents) is LLVM
+/// bitcode.
+bool LTOModule::isBitcodeFile(const void *Mem, size_t Length) {
+ ErrorOr<MemoryBufferRef> BCData = IRObjectFile::findBitcodeInMemBuffer(
+ MemoryBufferRef(StringRef((const char *)Mem, Length), "<mem>"));
+ return bool(BCData);
+}
+
+bool LTOModule::isBitcodeFile(const char *Path) {
+ ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
+ MemoryBuffer::getFile(Path);
+ if (!BufferOrErr)
+ return false;
+
+ ErrorOr<MemoryBufferRef> BCData = IRObjectFile::findBitcodeInMemBuffer(
+ BufferOrErr.get()->getMemBufferRef());
+ return bool(BCData);
+}
+
+bool LTOModule::isBitcodeForTarget(MemoryBuffer *Buffer,
+ StringRef TriplePrefix) {
+ ErrorOr<MemoryBufferRef> BCOrErr =
+ IRObjectFile::findBitcodeInMemBuffer(Buffer->getMemBufferRef());
+ if (!BCOrErr)
+ return false;
+ LLVMContext Context;
+ std::string Triple = getBitcodeTargetTriple(*BCOrErr, Context);
+ return StringRef(Triple).startswith(TriplePrefix);
+}
+
+std::string LTOModule::getProducerString(MemoryBuffer *Buffer) {
+ ErrorOr<MemoryBufferRef> BCOrErr =
+ IRObjectFile::findBitcodeInMemBuffer(Buffer->getMemBufferRef());
+ if (!BCOrErr)
+ return "";
+ LLVMContext Context;
+ return getBitcodeProducerString(*BCOrErr, Context);
+}
+
+ErrorOr<std::unique_ptr<LTOModule>>
+LTOModule::createFromFile(LLVMContext &Context, const char *path,
+ TargetOptions options) {
+ ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
+ MemoryBuffer::getFile(path);
+ if (std::error_code EC = BufferOrErr.getError())
+ return EC;
+ std::unique_ptr<MemoryBuffer> Buffer = std::move(BufferOrErr.get());
+ return makeLTOModule(Buffer->getMemBufferRef(), options, &Context);
+}
+
+ErrorOr<std::unique_ptr<LTOModule>>
+LTOModule::createFromOpenFile(LLVMContext &Context, int fd, const char *path,
+ size_t size, TargetOptions options) {
+ return createFromOpenFileSlice(Context, fd, path, size, 0, options);
+}
+
+ErrorOr<std::unique_ptr<LTOModule>>
+LTOModule::createFromOpenFileSlice(LLVMContext &Context, int fd,
+ const char *path, size_t map_size,
+ off_t offset, TargetOptions options) {
+ ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
+ MemoryBuffer::getOpenFileSlice(fd, path, map_size, offset);
+ if (std::error_code EC = BufferOrErr.getError())
+ return EC;
+ std::unique_ptr<MemoryBuffer> Buffer = std::move(BufferOrErr.get());
+ return makeLTOModule(Buffer->getMemBufferRef(), options, &Context);
+}
+
+ErrorOr<std::unique_ptr<LTOModule>>
+LTOModule::createFromBuffer(LLVMContext &Context, const void *mem,
+ size_t length, TargetOptions options,
+ StringRef path) {
+ return createInContext(mem, length, options, path, &Context);
+}
+
+ErrorOr<std::unique_ptr<LTOModule>>
+LTOModule::createInLocalContext(const void *mem, size_t length,
+ TargetOptions options, StringRef path) {
+ return createInContext(mem, length, options, path, nullptr);
+}
+
+ErrorOr<std::unique_ptr<LTOModule>>
+LTOModule::createInContext(const void *mem, size_t length,
+ TargetOptions options, StringRef path,
+ LLVMContext *Context) {
+ StringRef Data((const char *)mem, length);
+ MemoryBufferRef Buffer(Data, path);
+ return makeLTOModule(Buffer, options, Context);
+}
+
+static ErrorOr<std::unique_ptr<Module>>
+parseBitcodeFileImpl(MemoryBufferRef Buffer, LLVMContext &Context,
+ bool ShouldBeLazy) {
+
+ // Find the buffer.
+ ErrorOr<MemoryBufferRef> MBOrErr =
+ IRObjectFile::findBitcodeInMemBuffer(Buffer);
+ if (std::error_code EC = MBOrErr.getError())
+ return EC;
+
+ if (!ShouldBeLazy) {
+ // Parse the full file.
+ ErrorOr<std::unique_ptr<Module>> M = parseBitcodeFile(*MBOrErr, Context);
+ if (std::error_code EC = M.getError())
+ return EC;
+ return std::move(*M);
+ }
+
+ // Parse lazily.
+ std::unique_ptr<MemoryBuffer> LightweightBuf =
+ MemoryBuffer::getMemBuffer(*MBOrErr, false);
+ ErrorOr<std::unique_ptr<Module>> M = getLazyBitcodeModule(
+ std::move(LightweightBuf), Context, true /*ShouldLazyLoadMetadata*/);
+ if (std::error_code EC = M.getError())
+ return EC;
+ return std::move(*M);
+}
+
+ErrorOr<std::unique_ptr<LTOModule>>
+LTOModule::makeLTOModule(MemoryBufferRef Buffer, TargetOptions options,
+ LLVMContext *Context) {
+ std::unique_ptr<LLVMContext> OwnedContext;
+ if (!Context) {
+ OwnedContext = llvm::make_unique<LLVMContext>();
+ Context = OwnedContext.get();
+ }
+
+ // If we own a context, we know this is being used only for symbol
+ // extraction, not linking. Be lazy in that case.
+ ErrorOr<std::unique_ptr<Module>> MOrErr =
+ parseBitcodeFileImpl(Buffer, *Context,
+ /* ShouldBeLazy */ static_cast<bool>(OwnedContext));
+ if (std::error_code EC = MOrErr.getError())
+ return EC;
+ std::unique_ptr<Module> &M = *MOrErr;
+
+ std::string TripleStr = M->getTargetTriple();
+ if (TripleStr.empty())
+ TripleStr = sys::getDefaultTargetTriple();
+ llvm::Triple Triple(TripleStr);
+
+ // find machine architecture for this module
+ std::string errMsg;
+ const Target *march = TargetRegistry::lookupTarget(TripleStr, errMsg);
+ if (!march)
+ return std::unique_ptr<LTOModule>(nullptr);
+
+ // construct LTOModule, hand over ownership of module and target
+ SubtargetFeatures Features;
+ Features.getDefaultSubtargetFeatures(Triple);
+ std::string FeatureStr = Features.getString();
+ // Set a default CPU for Darwin triples.
+ std::string CPU;
+ if (Triple.isOSDarwin()) {
+ if (Triple.getArch() == llvm::Triple::x86_64)
+ CPU = "core2";
+ else if (Triple.getArch() == llvm::Triple::x86)
+ CPU = "yonah";
+ else if (Triple.getArch() == llvm::Triple::aarch64)
+ CPU = "cyclone";
+ }
+
+ TargetMachine *target = march->createTargetMachine(TripleStr, CPU, FeatureStr,
+ options);
+ M->setDataLayout(target->createDataLayout());
+
+ std::unique_ptr<object::IRObjectFile> IRObj(
+ new object::IRObjectFile(Buffer, std::move(M)));
+
+ std::unique_ptr<LTOModule> Ret;
+ if (OwnedContext)
+ Ret.reset(new LTOModule(std::move(IRObj), target, std::move(OwnedContext)));
+ else
+ Ret.reset(new LTOModule(std::move(IRObj), target));
+
+ Ret->parseSymbols();
+ Ret->parseMetadata();
+
+ return std::move(Ret);
+}
+
+/// Create a MemoryBuffer from a memory range with an optional name.
+std::unique_ptr<MemoryBuffer>
+LTOModule::makeBuffer(const void *mem, size_t length, StringRef name) {
+ const char *startPtr = (const char*)mem;
+ return MemoryBuffer::getMemBuffer(StringRef(startPtr, length), name, false);
+}
+
+/// objcClassNameFromExpression - Get string that the data pointer points to.
+bool
+LTOModule::objcClassNameFromExpression(const Constant *c, std::string &name) {
+ if (const ConstantExpr *ce = dyn_cast<ConstantExpr>(c)) {
+ Constant *op = ce->getOperand(0);
+ if (GlobalVariable *gvn = dyn_cast<GlobalVariable>(op)) {
+ Constant *cn = gvn->getInitializer();
+ if (ConstantDataArray *ca = dyn_cast<ConstantDataArray>(cn)) {
+ if (ca->isCString()) {
+ name = (".objc_class_name_" + ca->getAsCString()).str();
+ return true;
+ }
+ }
+ }
+ }
+ return false;
+}
+
+/// addObjCClass - Parse i386/ppc ObjC class data structure.
+void LTOModule::addObjCClass(const GlobalVariable *clgv) {
+ const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer());
+ if (!c) return;
+
+ // second slot in __OBJC,__class is pointer to superclass name
+ std::string superclassName;
+ if (objcClassNameFromExpression(c->getOperand(1), superclassName)) {
+ auto IterBool =
+ _undefines.insert(std::make_pair(superclassName, NameAndAttributes()));
+ if (IterBool.second) {
+ NameAndAttributes &info = IterBool.first->second;
+ info.name = IterBool.first->first().data();
+ info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
+ info.isFunction = false;
+ info.symbol = clgv;
+ }
+ }
+
+ // third slot in __OBJC,__class is pointer to class name
+ std::string className;
+ if (objcClassNameFromExpression(c->getOperand(2), className)) {
+ auto Iter = _defines.insert(className).first;
+
+ NameAndAttributes info;
+ info.name = Iter->first().data();
+ info.attributes = LTO_SYMBOL_PERMISSIONS_DATA |
+ LTO_SYMBOL_DEFINITION_REGULAR | LTO_SYMBOL_SCOPE_DEFAULT;
+ info.isFunction = false;
+ info.symbol = clgv;
+ _symbols.push_back(info);
+ }
+}
+
+/// addObjCCategory - Parse i386/ppc ObjC category data structure.
+void LTOModule::addObjCCategory(const GlobalVariable *clgv) {
+ const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer());
+ if (!c) return;
+
+ // second slot in __OBJC,__category is pointer to target class name
+ std::string targetclassName;
+ if (!objcClassNameFromExpression(c->getOperand(1), targetclassName))
+ return;
+
+ auto IterBool =
+ _undefines.insert(std::make_pair(targetclassName, NameAndAttributes()));
+
+ if (!IterBool.second)
+ return;
+
+ NameAndAttributes &info = IterBool.first->second;
+ info.name = IterBool.first->first().data();
+ info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
+ info.isFunction = false;
+ info.symbol = clgv;
+}
+
+/// addObjCClassRef - Parse i386/ppc ObjC class list data structure.
+void LTOModule::addObjCClassRef(const GlobalVariable *clgv) {
+ std::string targetclassName;
+ if (!objcClassNameFromExpression(clgv->getInitializer(), targetclassName))
+ return;
+
+ auto IterBool =
+ _undefines.insert(std::make_pair(targetclassName, NameAndAttributes()));
+
+ if (!IterBool.second)
+ return;
+
+ NameAndAttributes &info = IterBool.first->second;
+ info.name = IterBool.first->first().data();
+ info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
+ info.isFunction = false;
+ info.symbol = clgv;
+}
+
+void LTOModule::addDefinedDataSymbol(const object::BasicSymbolRef &Sym) {
+ SmallString<64> Buffer;
+ {
+ raw_svector_ostream OS(Buffer);
+ Sym.printName(OS);
+ }
+
+ const GlobalValue *V = IRFile->getSymbolGV(Sym.getRawDataRefImpl());
+ addDefinedDataSymbol(Buffer.c_str(), V);
+}
+
+void LTOModule::addDefinedDataSymbol(const char *Name, const GlobalValue *v) {
+ // Add to list of defined symbols.
+ addDefinedSymbol(Name, v, false);
+
+ if (!v->hasSection() /* || !isTargetDarwin */)
+ return;
+
+ // Special case i386/ppc ObjC data structures in magic sections:
+ // The issue is that the old ObjC object format did some strange
+ // contortions to avoid real linker symbols. For instance, the
+ // ObjC class data structure is allocated statically in the executable
+ // that defines that class. That data structures contains a pointer to
+ // its superclass. But instead of just initializing that part of the
+ // struct to the address of its superclass, and letting the static and
+ // dynamic linkers do the rest, the runtime works by having that field
+ // instead point to a C-string that is the name of the superclass.
+ // At runtime the objc initialization updates that pointer and sets
+ // it to point to the actual super class. As far as the linker
+ // knows it is just a pointer to a string. But then someone wanted the
+ // linker to issue errors at build time if the superclass was not found.
+ // So they figured out a way in mach-o object format to use an absolute
+ // symbols (.objc_class_name_Foo = 0) and a floating reference
+ // (.reference .objc_class_name_Bar) to cause the linker into erroring when
+ // a class was missing.
+ // The following synthesizes the implicit .objc_* symbols for the linker
+ // from the ObjC data structures generated by the front end.
+
+ // special case if this data blob is an ObjC class definition
+ std::string Section = v->getSection();
+ if (Section.compare(0, 15, "__OBJC,__class,") == 0) {
+ if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
+ addObjCClass(gv);
+ }
+ }
+
+ // special case if this data blob is an ObjC category definition
+ else if (Section.compare(0, 18, "__OBJC,__category,") == 0) {
+ if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
+ addObjCCategory(gv);
+ }
+ }
+
+ // special case if this data blob is the list of referenced classes
+ else if (Section.compare(0, 18, "__OBJC,__cls_refs,") == 0) {
+ if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
+ addObjCClassRef(gv);
+ }
+ }
+}
+
+void LTOModule::addDefinedFunctionSymbol(const object::BasicSymbolRef &Sym) {
+ SmallString<64> Buffer;
+ {
+ raw_svector_ostream OS(Buffer);
+ Sym.printName(OS);
+ }
+
+ const Function *F =
+ cast<Function>(IRFile->getSymbolGV(Sym.getRawDataRefImpl()));
+ addDefinedFunctionSymbol(Buffer.c_str(), F);
+}
+
+void LTOModule::addDefinedFunctionSymbol(const char *Name, const Function *F) {
+ // add to list of defined symbols
+ addDefinedSymbol(Name, F, true);
+}
+
+void LTOModule::addDefinedSymbol(const char *Name, const GlobalValue *def,
+ bool isFunction) {
+ // set alignment part log2() can have rounding errors
+ uint32_t align = def->getAlignment();
+ uint32_t attr = align ? countTrailingZeros(align) : 0;
+
+ // set permissions part
+ if (isFunction) {
+ attr |= LTO_SYMBOL_PERMISSIONS_CODE;
+ } else {
+ const GlobalVariable *gv = dyn_cast<GlobalVariable>(def);
+ if (gv && gv->isConstant())
+ attr |= LTO_SYMBOL_PERMISSIONS_RODATA;
+ else
+ attr |= LTO_SYMBOL_PERMISSIONS_DATA;
+ }
+
+ // set definition part
+ if (def->hasWeakLinkage() || def->hasLinkOnceLinkage())
+ attr |= LTO_SYMBOL_DEFINITION_WEAK;
+ else if (def->hasCommonLinkage())
+ attr |= LTO_SYMBOL_DEFINITION_TENTATIVE;
+ else
+ attr |= LTO_SYMBOL_DEFINITION_REGULAR;
+
+ // set scope part
+ if (def->hasLocalLinkage())
+ // Ignore visibility if linkage is local.
+ attr |= LTO_SYMBOL_SCOPE_INTERNAL;
+ else if (def->hasHiddenVisibility())
+ attr |= LTO_SYMBOL_SCOPE_HIDDEN;
+ else if (def->hasProtectedVisibility())
+ attr |= LTO_SYMBOL_SCOPE_PROTECTED;
+ else if (canBeOmittedFromSymbolTable(def))
+ attr |= LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN;
+ else
+ attr |= LTO_SYMBOL_SCOPE_DEFAULT;
+
+ if (def->hasComdat())
+ attr |= LTO_SYMBOL_COMDAT;
+
+ if (isa<GlobalAlias>(def))
+ attr |= LTO_SYMBOL_ALIAS;
+
+ auto Iter = _defines.insert(Name).first;
+
+ // fill information structure
+ NameAndAttributes info;
+ StringRef NameRef = Iter->first();
+ info.name = NameRef.data();
+ assert(info.name[NameRef.size()] == '\0');
+ info.attributes = attr;
+ info.isFunction = isFunction;
+ info.symbol = def;
+
+ // add to table of symbols
+ _symbols.push_back(info);
+}
+
+/// addAsmGlobalSymbol - Add a global symbol from module-level ASM to the
+/// defined list.
+void LTOModule::addAsmGlobalSymbol(const char *name,
+ lto_symbol_attributes scope) {
+ auto IterBool = _defines.insert(name);
+
+ // only add new define if not already defined
+ if (!IterBool.second)
+ return;
+
+ NameAndAttributes &info = _undefines[IterBool.first->first().data()];
+
+ if (info.symbol == nullptr) {
+ // FIXME: This is trying to take care of module ASM like this:
+ //
+ // module asm ".zerofill __FOO, __foo, _bar_baz_qux, 0"
+ //
+ // but is gross and its mother dresses it funny. Have the ASM parser give us
+ // more details for this type of situation so that we're not guessing so
+ // much.
+
+ // fill information structure
+ info.name = IterBool.first->first().data();
+ info.attributes =
+ LTO_SYMBOL_PERMISSIONS_DATA | LTO_SYMBOL_DEFINITION_REGULAR | scope;
+ info.isFunction = false;
+ info.symbol = nullptr;
+
+ // add to table of symbols
+ _symbols.push_back(info);
+ return;
+ }
+
+ if (info.isFunction)
+ addDefinedFunctionSymbol(info.name, cast<Function>(info.symbol));
+ else
+ addDefinedDataSymbol(info.name, info.symbol);
+
+ _symbols.back().attributes &= ~LTO_SYMBOL_SCOPE_MASK;
+ _symbols.back().attributes |= scope;
+}
+
+/// addAsmGlobalSymbolUndef - Add a global symbol from module-level ASM to the
+/// undefined list.
+void LTOModule::addAsmGlobalSymbolUndef(const char *name) {
+ auto IterBool = _undefines.insert(std::make_pair(name, NameAndAttributes()));
+
+ _asm_undefines.push_back(IterBool.first->first().data());
+
+ // we already have the symbol
+ if (!IterBool.second)
+ return;
+
+ uint32_t attr = LTO_SYMBOL_DEFINITION_UNDEFINED;
+ attr |= LTO_SYMBOL_SCOPE_DEFAULT;
+ NameAndAttributes &info = IterBool.first->second;
+ info.name = IterBool.first->first().data();
+ info.attributes = attr;
+ info.isFunction = false;
+ info.symbol = nullptr;
+}
+
+/// Add a symbol which isn't defined just yet to a list to be resolved later.
+void LTOModule::addPotentialUndefinedSymbol(const object::BasicSymbolRef &Sym,
+ bool isFunc) {
+ SmallString<64> name;
+ {
+ raw_svector_ostream OS(name);
+ Sym.printName(OS);
+ }
+
+ auto IterBool = _undefines.insert(std::make_pair(name, NameAndAttributes()));
+
+ // we already have the symbol
+ if (!IterBool.second)
+ return;
+
+ NameAndAttributes &info = IterBool.first->second;
+
+ info.name = IterBool.first->first().data();
+
+ const GlobalValue *decl = IRFile->getSymbolGV(Sym.getRawDataRefImpl());
+
+ if (decl->hasExternalWeakLinkage())
+ info.attributes = LTO_SYMBOL_DEFINITION_WEAKUNDEF;
+ else
+ info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
+
+ info.isFunction = isFunc;
+ info.symbol = decl;
+}
+
+void LTOModule::parseSymbols() {
+ for (auto &Sym : IRFile->symbols()) {
+ const GlobalValue *GV = IRFile->getSymbolGV(Sym.getRawDataRefImpl());
+ uint32_t Flags = Sym.getFlags();
+ if (Flags & object::BasicSymbolRef::SF_FormatSpecific)
+ continue;
+
+ bool IsUndefined = Flags & object::BasicSymbolRef::SF_Undefined;
+
+ if (!GV) {
+ SmallString<64> Buffer;
+ {
+ raw_svector_ostream OS(Buffer);
+ Sym.printName(OS);
+ }
+ const char *Name = Buffer.c_str();
+
+ if (IsUndefined)
+ addAsmGlobalSymbolUndef(Name);
+ else if (Flags & object::BasicSymbolRef::SF_Global)
+ addAsmGlobalSymbol(Name, LTO_SYMBOL_SCOPE_DEFAULT);
+ else
+ addAsmGlobalSymbol(Name, LTO_SYMBOL_SCOPE_INTERNAL);
+ continue;
+ }
+
+ auto *F = dyn_cast<Function>(GV);
+ if (IsUndefined) {
+ addPotentialUndefinedSymbol(Sym, F != nullptr);
+ continue;
+ }
+
+ if (F) {
+ addDefinedFunctionSymbol(Sym);
+ continue;
+ }
+
+ if (isa<GlobalVariable>(GV)) {
+ addDefinedDataSymbol(Sym);
+ continue;
+ }
+
+ assert(isa<GlobalAlias>(GV));
+ addDefinedDataSymbol(Sym);
+ }
+
+ // make symbols for all undefines
+ for (StringMap<NameAndAttributes>::iterator u =_undefines.begin(),
+ e = _undefines.end(); u != e; ++u) {
+ // If this symbol also has a definition, then don't make an undefine because
+ // it is a tentative definition.
+ if (_defines.count(u->getKey())) continue;
+ NameAndAttributes info = u->getValue();
+ _symbols.push_back(info);
+ }
+}
+
+/// parseMetadata - Parse metadata from the module
+void LTOModule::parseMetadata() {
+ raw_string_ostream OS(LinkerOpts);
+
+ // Linker Options
+ if (Metadata *Val = getModule().getModuleFlag("Linker Options")) {
+ MDNode *LinkerOptions = cast<MDNode>(Val);
+ for (unsigned i = 0, e = LinkerOptions->getNumOperands(); i != e; ++i) {
+ MDNode *MDOptions = cast<MDNode>(LinkerOptions->getOperand(i));
+ for (unsigned ii = 0, ie = MDOptions->getNumOperands(); ii != ie; ++ii) {
+ MDString *MDOption = cast<MDString>(MDOptions->getOperand(ii));
+ OS << " " << MDOption->getString();
+ }
+ }
+ }
+
+ // Globals
+ Mangler Mang;
+ for (const NameAndAttributes &Sym : _symbols) {
+ if (!Sym.symbol)
+ continue;
+ _target->getObjFileLowering()->emitLinkerFlagsForGlobal(OS, Sym.symbol,
+ Mang);
+ }
+
+ // Add other interesting metadata here.
+}
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