text: //===- lli.cpp - LLVM Interpreter / Dynamic compiler ----------------------===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  //
  // This utility provides a simple wrapper around the LLVM Execution Engines,
  // which allow the direct execution of LLVM programs through a Just-In-Time
  // compiler, or through an interpreter if no JIT is available for this platform.
  //
  //===----------------------------------------------------------------------===//
  
  #include "ExecutionUtils.h"
  #include "ForwardingMemoryManager.h"
  #include "llvm/ADT/StringExtras.h"
  #include "llvm/ADT/Triple.h"
  #include "llvm/Bitcode/BitcodeReader.h"
  #include "llvm/CodeGen/CommandFlags.h"
  #include "llvm/CodeGen/LinkAllCodegenComponents.h"
  #include "llvm/Config/llvm-config.h"
  #include "llvm/ExecutionEngine/GenericValue.h"
  #include "llvm/ExecutionEngine/Interpreter.h"
  #include "llvm/ExecutionEngine/JITEventListener.h"
  #include "llvm/ExecutionEngine/JITSymbol.h"
  #include "llvm/ExecutionEngine/MCJIT.h"
  #include "llvm/ExecutionEngine/ObjectCache.h"
  #include "llvm/ExecutionEngine/Orc/DebugObjectManagerPlugin.h"
  #include "llvm/ExecutionEngine/Orc/DebugUtils.h"
  #include "llvm/ExecutionEngine/Orc/EPCDebugObjectRegistrar.h"
  #include "llvm/ExecutionEngine/Orc/EPCEHFrameRegistrar.h"
  #include "llvm/ExecutionEngine/Orc/EPCGenericRTDyldMemoryManager.h"
  #include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"
  #include "llvm/ExecutionEngine/Orc/JITTargetMachineBuilder.h"
  #include "llvm/ExecutionEngine/Orc/LLJIT.h"
  #include "llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h"
  #include "llvm/ExecutionEngine/Orc/SimpleRemoteEPC.h"
  #include "llvm/ExecutionEngine/Orc/SymbolStringPool.h"
  #include "llvm/ExecutionEngine/Orc/TargetProcess/JITLoaderGDB.h"
  #include "llvm/ExecutionEngine/Orc/TargetProcess/RegisterEHFrames.h"
  #include "llvm/ExecutionEngine/Orc/TargetProcess/TargetExecutionUtils.h"
  #include "llvm/ExecutionEngine/SectionMemoryManager.h"
  #include "llvm/IR/IRBuilder.h"
  #include "llvm/IR/LLVMContext.h"
  #include "llvm/IR/Module.h"
  #include "llvm/IR/Type.h"
  #include "llvm/IR/Verifier.h"
  #include "llvm/IRReader/IRReader.h"
  #include "llvm/Object/Archive.h"
  #include "llvm/Object/ObjectFile.h"
  #include "llvm/Support/CommandLine.h"
  #include "llvm/Support/Debug.h"
  #include "llvm/Support/DynamicLibrary.h"
  #include "llvm/Support/Format.h"
  #include "llvm/Support/InitLLVM.h"
  #include "llvm/Support/ManagedStatic.h"
  #include "llvm/Support/MathExtras.h"
  #include "llvm/Support/Memory.h"
  #include "llvm/Support/MemoryBuffer.h"
  #include "llvm/Support/Path.h"
  #include "llvm/Support/PluginLoader.h"
  #include "llvm/Support/Process.h"
  #include "llvm/Support/Program.h"
  #include "llvm/Support/SourceMgr.h"
  #include "llvm/Support/TargetSelect.h"
  #include "llvm/Support/WithColor.h"
  #include "llvm/Support/raw_ostream.h"
  #include "llvm/Transforms/Instrumentation.h"
  #include <cerrno>
  
  #if !defined(_MSC_VER) && !defined(__MINGW32__)
  #include <unistd.h>
  #else
  #include <io.h>
  #endif
  
  #ifdef __CYGWIN__
  #include <cygwin/version.h>
  #if defined(CYGWIN_VERSION_DLL_MAJOR) && CYGWIN_VERSION_DLL_MAJOR<1007
  #define DO_NOTHING_ATEXIT 1
  #endif
  #endif
  
  using namespace llvm;
  
  static codegen::RegisterCodeGenFlags CGF;
  
  #define DEBUG_TYPE "lli"
  
  namespace {
  
    enum class JITKind { MCJIT, Orc, OrcLazy };
    enum class JITLinkerKind { Default, RuntimeDyld, JITLink };
  
    cl::opt<std::string>
    InputFile(cl::desc("<input bitcode>"), cl::Positional, cl::init("-"));
  
    cl::list<std::string>
    InputArgv(cl::ConsumeAfter, cl::desc("<program arguments>..."));
  
    cl::opt<bool> ForceInterpreter("force-interpreter",
                                   cl::desc("Force interpretation: disable JIT"),
                                   cl::init(false));
  
    cl::opt<JITKind> UseJITKind(
        "jit-kind", cl::desc("Choose underlying JIT kind."),
        cl::init(JITKind::Orc),
        cl::values(clEnumValN(JITKind::MCJIT, "mcjit", "MCJIT"),
                   clEnumValN(JITKind::Orc, "orc", "Orc JIT"),
                   clEnumValN(JITKind::OrcLazy, "orc-lazy",
                              "Orc-based lazy JIT.")));
  
    cl::opt<JITLinkerKind>
        JITLinker("jit-linker", cl::desc("Choose the dynamic linker/loader."),
                  cl::init(JITLinkerKind::Default),
                  cl::values(clEnumValN(JITLinkerKind::Default, "default",
                                        "Default for platform and JIT-kind"),
                             clEnumValN(JITLinkerKind::RuntimeDyld, "rtdyld",
                                        "RuntimeDyld"),
                             clEnumValN(JITLinkerKind::JITLink, "jitlink",
                                        "Orc-specific linker")));
  
    cl::opt<unsigned>
    LazyJITCompileThreads("compile-threads",
                          cl::desc("Choose the number of compile threads "
                                   "(jit-kind=orc-lazy only)"),
                          cl::init(0));
  
    cl::list<std::string>
    ThreadEntryPoints("thread-entry",
                      cl::desc("calls the given entry-point on a new thread "
                               "(jit-kind=orc-lazy only)"));
  
    cl::opt<bool> PerModuleLazy(
        "per-module-lazy",
        cl::desc("Performs lazy compilation on whole module boundaries "
                 "rather than individual functions"),
        cl::init(false));
  
    cl::list<std::string>
        JITDylibs("jd",
                  cl::desc("Specifies the JITDylib to be used for any subsequent "
                           "-extra-module arguments."));
  
    cl::list<std::string>
      Dylibs("dlopen", cl::desc("Dynamic libraries to load before linking"),
             cl::ZeroOrMore);
  
    // The MCJIT supports building for a target address space separate from
    // the JIT compilation process. Use a forked process and a copying
    // memory manager with IPC to execute using this functionality.
    cl::opt<bool> RemoteMCJIT("remote-mcjit",
      cl::desc("Execute MCJIT'ed code in a separate process."),
      cl::init(false));
  
    // Manually specify the child process for remote execution. This overrides
    // the simulated remote execution that allocates address space for child
    // execution. The child process will be executed and will communicate with
    // lli via stdin/stdout pipes.
    cl::opt<std::string>
    ChildExecPath("mcjit-remote-process",
                  cl::desc("Specify the filename of the process to launch "
                           "for remote MCJIT execution.  If none is specified,"
                           "\n\tremote execution will be simulated in-process."),
                  cl::value_desc("filename"), cl::init(""));
  
    // Determine optimization level.
    cl::opt<char>
    OptLevel("O",
             cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
                      "(default = '-O2')"),
             cl::Prefix,
             cl::ZeroOrMore,
             cl::init(' '));
  
    cl::opt<std::string>
    TargetTriple("mtriple", cl::desc("Override target triple for module"));
  
    cl::opt<std::string>
    EntryFunc("entry-function",
              cl::desc("Specify the entry function (default = 'main') "
                       "of the executable"),
              cl::value_desc("function"),
              cl::init("main"));
  
    cl::list<std::string>
    ExtraModules("extra-module",
           cl::desc("Extra modules to be loaded"),
           cl::value_desc("input bitcode"));
  
    cl::list<std::string>
    ExtraObjects("extra-object",
           cl::desc("Extra object files to be loaded"),
           cl::value_desc("input object"));
  
    cl::list<std::string>
    ExtraArchives("extra-archive",
           cl::desc("Extra archive files to be loaded"),
           cl::value_desc("input archive"));
  
    cl::opt<bool>
    EnableCacheManager("enable-cache-manager",
          cl::desc("Use cache manager to save/load modules"),
          cl::init(false));
  
    cl::opt<std::string>
    ObjectCacheDir("object-cache-dir",
                    cl::desc("Directory to store cached object files "
                             "(must be user writable)"),
                    cl::init(""));
  
    cl::opt<std::string>
    FakeArgv0("fake-argv0",
              cl::desc("Override the 'argv[0]' value passed into the executing"
                       " program"), cl::value_desc("executable"));
  
    cl::opt<bool>
    DisableCoreFiles("disable-core-files", cl::Hidden,
                     cl::desc("Disable emission of core files if possible"));
  
    cl::opt<bool>
    NoLazyCompilation("disable-lazy-compilation",
                    cl::desc("Disable JIT lazy compilation"),
                    cl::init(false));
  
    cl::opt<bool>
    GenerateSoftFloatCalls("soft-float",
      cl::desc("Generate software floating point library calls"),
      cl::init(false));
  
    cl::opt<bool> NoProcessSymbols(
        "no-process-syms",
        cl::desc("Do not resolve lli process symbols in JIT'd code"),
        cl::init(false));
  
    enum class LLJITPlatform { Inactive, DetectHost, GenericIR };
  
    cl::opt<LLJITPlatform>
        Platform("lljit-platform", cl::desc("Platform to use with LLJIT"),
                 cl::init(LLJITPlatform::DetectHost),
                 cl::values(clEnumValN(LLJITPlatform::DetectHost, "DetectHost",
                                       "Select based on JIT target triple"),
                            clEnumValN(LLJITPlatform::GenericIR, "GenericIR",
                                       "Use LLJITGenericIRPlatform"),
                            clEnumValN(LLJITPlatform::Inactive, "Inactive",
                                       "Disable platform support explicitly")),
                 cl::Hidden);
  
    enum class DumpKind {
      NoDump,
      DumpFuncsToStdOut,
      DumpModsToStdOut,
      DumpModsToDisk
    };
  
    cl::opt<DumpKind> OrcDumpKind(
        "orc-lazy-debug", cl::desc("Debug dumping for the orc-lazy JIT."),
        cl::init(DumpKind::NoDump),
        cl::values(clEnumValN(DumpKind::NoDump, "no-dump",
                              "Don't dump anything."),
                   clEnumValN(DumpKind::DumpFuncsToStdOut, "funcs-to-stdout",
                              "Dump function names to stdout."),
                   clEnumValN(DumpKind::DumpModsToStdOut, "mods-to-stdout",
                              "Dump modules to stdout."),
                   clEnumValN(DumpKind::DumpModsToDisk, "mods-to-disk",
                              "Dump modules to the current "
                              "working directory. (WARNING: "
                              "will overwrite existing files).")),
        cl::Hidden);
  
    cl::list<BuiltinFunctionKind> GenerateBuiltinFunctions(
        "generate",
        cl::desc("Provide built-in functions for access by JITed code "
                 "(jit-kind=orc-lazy only)"),
        cl::values(clEnumValN(BuiltinFunctionKind::DumpDebugDescriptor,
                              "__dump_jit_debug_descriptor",
                              "Dump __jit_debug_descriptor contents to stdout"),
                   clEnumValN(BuiltinFunctionKind::DumpDebugObjects,
                              "__dump_jit_debug_objects",
                              "Dump __jit_debug_descriptor in-memory debug "
                              "objects as tool output")),
        cl::Hidden);
  
    ExitOnError ExitOnErr;
  }
  
  LLVM_ATTRIBUTE_USED void linkComponents() {
    errs() << (void *)&llvm_orc_registerEHFrameSectionWrapper
           << (void *)&llvm_orc_deregisterEHFrameSectionWrapper
           << (void *)&llvm_orc_registerJITLoaderGDBWrapper;
  }
  
  //===----------------------------------------------------------------------===//
  // Object cache
  //
  // This object cache implementation writes cached objects to disk to the
  // directory specified by CacheDir, using a filename provided in the module
  // descriptor. The cache tries to load a saved object using that path if the
  // file exists. CacheDir defaults to "", in which case objects are cached
  // alongside their originating bitcodes.
  //
  class LLIObjectCache : public ObjectCache {
  public:
    LLIObjectCache(const std::string& CacheDir) : CacheDir(CacheDir) {
      // Add trailing '/' to cache dir if necessary.
      if (!this->CacheDir.empty() &&
          this->CacheDir[this->CacheDir.size() - 1] != '/')
        this->CacheDir += '/';
    }
    ~LLIObjectCache() override {}
  
    void notifyObjectCompiled(const Module *M, MemoryBufferRef Obj) override {
      const std::string &ModuleID = M->getModuleIdentifier();
      std::string CacheName;
      if (!getCacheFilename(ModuleID, CacheName))
        return;
      if (!CacheDir.empty()) { // Create user-defined cache dir.
        SmallString<128> dir(sys::path::parent_path(CacheName));
        sys::fs::create_directories(Twine(dir));
      }
  
      std::error_code EC;
      raw_fd_ostream outfile(CacheName, EC, sys::fs::OF_None);
      outfile.write(Obj.getBufferStart(), Obj.getBufferSize());
      outfile.close();
    }
  
    std::unique_ptr<MemoryBuffer> getObject(const Module* M) override {
      const std::string &ModuleID = M->getModuleIdentifier();
      std::string CacheName;
      if (!getCacheFilename(ModuleID, CacheName))
        return nullptr;
      // Load the object from the cache filename
      ErrorOr<std::unique_ptr<MemoryBuffer>> IRObjectBuffer =
          MemoryBuffer::getFile(CacheName, /*IsText=*/false,
                                /*RequiresNullTerminator=*/false);
      // If the file isn't there, that's OK.
      if (!IRObjectBuffer)
        return nullptr;
      // MCJIT will want to write into this buffer, and we don't want that
      // because the file has probably just been mmapped.  Instead we make
      // a copy.  The filed-based buffer will be released when it goes
      // out of scope.
      return MemoryBuffer::getMemBufferCopy(IRObjectBuffer.get()->getBuffer());
    }
  
  private:
    std::string CacheDir;
  
    bool getCacheFilename(const std::string &ModID, std::string &CacheName) {
      std::string Prefix("file:");
      size_t PrefixLength = Prefix.length();
      if (ModID.substr(0, PrefixLength) != Prefix)
        return false;
  
      std::string CacheSubdir = ModID.substr(PrefixLength);
      // Transform "X:\foo" => "/X\foo" for convenience on Windows.
      if (is_style_windows(llvm::sys::path::Style::native) &&
          isalpha(CacheSubdir[0]) && CacheSubdir[1] == ':') {
        CacheSubdir[1] = CacheSubdir[0];
        CacheSubdir[0] = '/';
      }
  
      CacheName = CacheDir + CacheSubdir;
      size_t pos = CacheName.rfind('.');
      CacheName.replace(pos, CacheName.length() - pos, ".o");
      return true;
    }
  };
  
  // On Mingw and Cygwin, an external symbol named '__main' is called from the
  // generated 'main' function to allow static initialization.  To avoid linking
  // problems with remote targets (because lli's remote target support does not
  // currently handle external linking) we add a secondary module which defines
  // an empty '__main' function.
  static void addCygMingExtraModule(ExecutionEngine &EE, LLVMContext &Context,
                                    StringRef TargetTripleStr) {
    IRBuilder<> Builder(Context);
    Triple TargetTriple(TargetTripleStr);
  
    // Create a new module.
    std::unique_ptr<Module> M = std::make_unique<Module>("CygMingHelper", Context);
    M->setTargetTriple(TargetTripleStr);
  
    // Create an empty function named "__main".
    Type *ReturnTy;
    if (TargetTriple.isArch64Bit())
      ReturnTy = Type::getInt64Ty(Context);
    else
      ReturnTy = Type::getInt32Ty(Context);
    Function *Result =
        Function::Create(FunctionType::get(ReturnTy, {}, false),
                         GlobalValue::ExternalLinkage, "__main", M.get());
  
    BasicBlock *BB = BasicBlock::Create(Context, "__main", Result);
    Builder.SetInsertPoint(BB);
    Value *ReturnVal = ConstantInt::get(ReturnTy, 0);
    Builder.CreateRet(ReturnVal);
  
    // Add this new module to the ExecutionEngine.
    EE.addModule(std::move(M));
  }
  
  CodeGenOpt::Level getOptLevel() {
    switch (OptLevel) {
    default:
      WithColor::error(errs(), "lli") << "invalid optimization level.\n";
      exit(1);
    case '0': return CodeGenOpt::None;
    case '1': return CodeGenOpt::Less;
    case ' ':
    case '2': return CodeGenOpt::Default;
    case '3': return CodeGenOpt::Aggressive;
    }
    llvm_unreachable("Unrecognized opt level.");
  }
  
  [[noreturn]] static void reportError(SMDiagnostic Err, const char *ProgName) {
    Err.print(ProgName, errs());
    exit(1);
  }
  
  Error loadDylibs();
  int runOrcJIT(const char *ProgName);
  void disallowOrcOptions();
  Expected<std::unique_ptr<orc::ExecutorProcessControl>> launchRemote();
  
  //===----------------------------------------------------------------------===//
  // main Driver function
  //
  int main(int argc, char **argv, char * const *envp) {
    InitLLVM X(argc, argv);
  
    if (argc > 1)
      ExitOnErr.setBanner(std::string(argv[0]) + ": ");
  
    // If we have a native target, initialize it to ensure it is linked in and
    // usable by the JIT.
    InitializeNativeTarget();
    InitializeNativeTargetAsmPrinter();
    InitializeNativeTargetAsmParser();
  
    cl::ParseCommandLineOptions(argc, argv,
                                "llvm interpreter & dynamic compiler\n");
  
    // If the user doesn't want core files, disable them.
    if (DisableCoreFiles)
      sys::Process::PreventCoreFiles();
  
    ExitOnErr(loadDylibs());
  
    if (UseJITKind == JITKind::MCJIT)
      disallowOrcOptions();
    else
      return runOrcJIT(argv[0]);
  
    // Old lli implementation based on ExecutionEngine and MCJIT.
    LLVMContext Context;
  
    // Load the bitcode...
    SMDiagnostic Err;
    std::unique_ptr<Module> Owner = parseIRFile(InputFile, Err, Context);
    Module *Mod = Owner.get();
    if (!Mod)
      reportError(Err, argv[0]);
  
    if (EnableCacheManager) {
      std::string CacheName("file:");
      CacheName.append(InputFile);
      Mod->setModuleIdentifier(CacheName);
    }
  
    // If not jitting lazily, load the whole bitcode file eagerly too.
    if (NoLazyCompilation) {
      // Use *argv instead of argv[0] to work around a wrong GCC warning.
      ExitOnError ExitOnErr(std::string(*argv) +
                            ": bitcode didn't read correctly: ");
      ExitOnErr(Mod->materializeAll());
    }
  
    std::string ErrorMsg;
    EngineBuilder builder(std::move(Owner));
    builder.setMArch(codegen::getMArch());
    builder.setMCPU(codegen::getCPUStr());
    builder.setMAttrs(codegen::getFeatureList());
    if (auto RM = codegen::getExplicitRelocModel())
      builder.setRelocationModel(RM.getValue());
    if (auto CM = codegen::getExplicitCodeModel())
      builder.setCodeModel(CM.getValue());
    builder.setErrorStr(&ErrorMsg);
    builder.setEngineKind(ForceInterpreter
                          ? EngineKind::Interpreter
                          : EngineKind::JIT);
  
    // If we are supposed to override the target triple, do so now.
    if (!TargetTriple.empty())
      Mod->setTargetTriple(Triple::normalize(TargetTriple));
  
    // Enable MCJIT if desired.
    RTDyldMemoryManager *RTDyldMM = nullptr;
    if (!ForceInterpreter) {
      if (RemoteMCJIT)
        RTDyldMM = new ForwardingMemoryManager();
      else
        RTDyldMM = new SectionMemoryManager();
  
      // Deliberately construct a temp std::unique_ptr to pass in. Do not null out
      // RTDyldMM: We still use it below, even though we don't own it.
      builder.setMCJITMemoryManager(
        std::unique_ptr<RTDyldMemoryManager>(RTDyldMM));
    } else if (RemoteMCJIT) {
      WithColor::error(errs(), argv[0])
          << "remote process execution does not work with the interpreter.\n";
      exit(1);
    }
  
    builder.setOptLevel(getOptLevel());
  
    TargetOptions Options =
        codegen::InitTargetOptionsFromCodeGenFlags(Triple(TargetTriple));
    if (codegen::getFloatABIForCalls() != FloatABI::Default)
      Options.FloatABIType = codegen::getFloatABIForCalls();
  
    builder.setTargetOptions(Options);
  
    std::unique_ptr<ExecutionEngine> EE(builder.create());
    if (!EE) {
      if (!ErrorMsg.empty())
        WithColor::error(errs(), argv[0])
            << "error creating EE: " << ErrorMsg << "\n";
      else
        WithColor::error(errs(), argv[0]) << "unknown error creating EE!\n";
      exit(1);
    }
  
    std::unique_ptr<LLIObjectCache> CacheManager;
    if (EnableCacheManager) {
      CacheManager.reset(new LLIObjectCache(ObjectCacheDir));
      EE->setObjectCache(CacheManager.get());
    }
  
    // Load any additional modules specified on the command line.
    for (unsigned i = 0, e = ExtraModules.size(); i != e; ++i) {
      std::unique_ptr<Module> XMod = parseIRFile(ExtraModules[i], Err, Context);
      if (!XMod)
        reportError(Err, argv[0]);
      if (EnableCacheManager) {
        std::string CacheName("file:");
        CacheName.append(ExtraModules[i]);
        XMod->setModuleIdentifier(CacheName);
      }
      EE->addModule(std::move(XMod));
    }
  
    for (unsigned i = 0, e = ExtraObjects.size(); i != e; ++i) {
      Expected<object::OwningBinary<object::ObjectFile>> Obj =
          object::ObjectFile::createObjectFile(ExtraObjects[i]);
      if (!Obj) {
        // TODO: Actually report errors helpfully.
        consumeError(Obj.takeError());
        reportError(Err, argv[0]);
      }
      object::OwningBinary<object::ObjectFile> &O = Obj.get();
      EE->addObjectFile(std::move(O));
    }
  
    for (unsigned i = 0, e = ExtraArchives.size(); i != e; ++i) {
      ErrorOr<std::unique_ptr<MemoryBuffer>> ArBufOrErr =
          MemoryBuffer::getFileOrSTDIN(ExtraArchives[i]);
      if (!ArBufOrErr)
        reportError(Err, argv[0]);
      std::unique_ptr<MemoryBuffer> &ArBuf = ArBufOrErr.get();
  
      Expected<std::unique_ptr<object::Archive>> ArOrErr =
          object::Archive::create(ArBuf->getMemBufferRef());
      if (!ArOrErr) {
        std::string Buf;
        raw_string_ostream OS(Buf);
        logAllUnhandledErrors(ArOrErr.takeError(), OS);
        OS.flush();
        errs() << Buf;
        exit(1);
      }
      std::unique_ptr<object::Archive> &Ar = ArOrErr.get();
  
      object::OwningBinary<object::Archive> OB(std::move(Ar), std::move(ArBuf));
  
      EE->addArchive(std::move(OB));
    }
  
    // If the target is Cygwin/MingW and we are generating remote code, we
    // need an extra module to help out with linking.
    if (RemoteMCJIT && Triple(Mod->getTargetTriple()).isOSCygMing()) {
      addCygMingExtraModule(*EE, Context, Mod->getTargetTriple());
    }
  
    // The following functions have no effect if their respective profiling
    // support wasn't enabled in the build configuration.
    EE->RegisterJITEventListener(
                  JITEventListener::createOProfileJITEventListener());
    EE->RegisterJITEventListener(
                  JITEventListener::createIntelJITEventListener());
    if (!RemoteMCJIT)
      EE->RegisterJITEventListener(
                  JITEventListener::createPerfJITEventListener());
  
    if (!NoLazyCompilation && RemoteMCJIT) {
      WithColor::warning(errs(), argv[0])
          << "remote mcjit does not support lazy compilation\n";
      NoLazyCompilation = true;
    }
    EE->DisableLazyCompilation(NoLazyCompilation);
  
    // If the user specifically requested an argv[0] to pass into the program,
    // do it now.
    if (!FakeArgv0.empty()) {
      InputFile = static_cast<std::string>(FakeArgv0);
    } else {
      // Otherwise, if there is a .bc suffix on the executable strip it off, it
      // might confuse the program.
      if (StringRef(InputFile).endswith(".bc"))
        InputFile.erase(InputFile.length() - 3);
    }
  
    // Add the module's name to the start of the vector of arguments to main().
    InputArgv.insert(InputArgv.begin(), InputFile);
  
    // Call the main function from M as if its signature were:
    //   int main (int argc, char **argv, const char **envp)
    // using the contents of Args to determine argc & argv, and the contents of
    // EnvVars to determine envp.
    //
    Function *EntryFn = Mod->getFunction(EntryFunc);
    if (!EntryFn) {
      WithColor::error(errs(), argv[0])
          << '\'' << EntryFunc << "\' function not found in module.\n";
      return -1;
    }
  
    // Reset errno to zero on entry to main.
    errno = 0;
  
    int Result = -1;
  
    // Sanity check use of remote-jit: LLI currently only supports use of the
    // remote JIT on Unix platforms.
    if (RemoteMCJIT) {
  #ifndef LLVM_ON_UNIX
      WithColor::warning(errs(), argv[0])
          << "host does not support external remote targets.\n";
      WithColor::note() << "defaulting to local execution\n";
      return -1;
  #else
      if (ChildExecPath.empty()) {
        WithColor::error(errs(), argv[0])
            << "-remote-mcjit requires -mcjit-remote-process.\n";
        exit(1);
      } else if (!sys::fs::can_execute(ChildExecPath)) {
        WithColor::error(errs(), argv[0])
            << "unable to find usable child executable: '" << ChildExecPath
            << "'\n";
        return -1;
      }
  #endif
    }
  
    std::unique_ptr<orc::ExecutorProcessControl> EPC =
        RemoteMCJIT ? ExitOnErr(launchRemote())
                    : ExitOnErr(orc::SelfExecutorProcessControl::Create());
  
    if (!RemoteMCJIT) {
      // If the program doesn't explicitly call exit, we will need the Exit
      // function later on to make an explicit call, so get the function now.
      FunctionCallee Exit = Mod->getOrInsertFunction(
          "exit", Type::getVoidTy(Context), Type::getInt32Ty(Context));
  
      // Run static constructors.
      if (!ForceInterpreter) {
        // Give MCJIT a chance to apply relocations and set page permissions.
        EE->finalizeObject();
      }
      EE->runStaticConstructorsDestructors(false);
  
      // Trigger compilation separately so code regions that need to be
      // invalidated will be known.
      (void)EE->getPointerToFunction(EntryFn);
      // Clear instruction cache before code will be executed.
      if (RTDyldMM)
        static_cast<SectionMemoryManager*>(RTDyldMM)->invalidateInstructionCache();
  
      // Run main.
      Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
  
      // Run static destructors.
      EE->runStaticConstructorsDestructors(true);
  
      // If the program didn't call exit explicitly, we should call it now.
      // This ensures that any atexit handlers get called correctly.
      if (Function *ExitF =
              dyn_cast<Function>(Exit.getCallee()->stripPointerCasts())) {
        if (ExitF->getFunctionType() == Exit.getFunctionType()) {
          std::vector<GenericValue> Args;
          GenericValue ResultGV;
          ResultGV.IntVal = APInt(32, Result);
          Args.push_back(ResultGV);
          EE->runFunction(ExitF, Args);
          WithColor::error(errs(), argv[0])
              << "exit(" << Result << ") returned!\n";
          abort();
        }
      }
      WithColor::error(errs(), argv[0]) << "exit defined with wrong prototype!\n";
      abort();
    } else {
      // else == "if (RemoteMCJIT)"
  
      // Remote target MCJIT doesn't (yet) support static constructors. No reason
      // it couldn't. This is a limitation of the LLI implementation, not the
      // MCJIT itself. FIXME.
  
      // Create a remote memory manager.
      auto RemoteMM = ExitOnErr(
          orc::EPCGenericRTDyldMemoryManager::CreateWithDefaultBootstrapSymbols(
              *EPC));
  
      // Forward MCJIT's memory manager calls to the remote memory manager.
      static_cast<ForwardingMemoryManager*>(RTDyldMM)->setMemMgr(
        std::move(RemoteMM));
  
      // Forward MCJIT's symbol resolution calls to the remote.
      static_cast<ForwardingMemoryManager *>(RTDyldMM)->setResolver(
          ExitOnErr(RemoteResolver::Create(*EPC)));
      // Grab the target address of the JIT'd main function on the remote and call
      // it.
      // FIXME: argv and envp handling.
      auto Entry =
          orc::ExecutorAddr(EE->getFunctionAddress(EntryFn->getName().str()));
      EE->finalizeObject();
      LLVM_DEBUG(dbgs() << "Executing '" << EntryFn->getName() << "' at 0x"
                        << format("%llx", Entry.getValue()) << "\n");
      Result = ExitOnErr(EPC->runAsMain(Entry, {}));
  
      // Like static constructors, the remote target MCJIT support doesn't handle
      // this yet. It could. FIXME.
  
      // Delete the EE - we need to tear it down *before* we terminate the session
      // with the remote, otherwise it'll crash when it tries to release resources
      // on a remote that has already been disconnected.
      EE.reset();
  
      // Signal the remote target that we're done JITing.
      ExitOnErr(EPC->disconnect());
    }
  
    return Result;
  }
  
  static std::function<void(Module &)> createDebugDumper() {
    switch (OrcDumpKind) {
    case DumpKind::NoDump:
      return [](Module &M) {};
  
    case DumpKind::DumpFuncsToStdOut:
      return [](Module &M) {
        printf("[ ");
  
        for (const auto &F : M) {
          if (F.isDeclaration())
            continue;
  
          if (F.hasName()) {
            std::string Name(std::string(F.getName()));
            printf("%s ", Name.c_str());
          } else
            printf("<anon> ");
        }
  
        printf("]\n");
      };
  
    case DumpKind::DumpModsToStdOut:
      return [](Module &M) {
        outs() << "----- Module Start -----\n" << M << "----- Module End -----\n";
      };
  
    case DumpKind::DumpModsToDisk:
      return [](Module &M) {
        std::error_code EC;
        raw_fd_ostream Out(M.getModuleIdentifier() + ".ll", EC,
                           sys::fs::OF_TextWithCRLF);
        if (EC) {
          errs() << "Couldn't open " << M.getModuleIdentifier()
                 << " for dumping.\nError:" << EC.message() << "\n";
          exit(1);
        }
        Out << M;
      };
    }
    llvm_unreachable("Unknown DumpKind");
  }
  
  Error loadDylibs() {
    for (const auto &Dylib : Dylibs) {
      std::string ErrMsg;
      if (sys::DynamicLibrary::LoadLibraryPermanently(Dylib.c_str(), &ErrMsg))
        return make_error<StringError>(ErrMsg, inconvertibleErrorCode());
    }
  
    return Error::success();
  }
  
  static void exitOnLazyCallThroughFailure() { exit(1); }
  
  Expected<orc::ThreadSafeModule>
  loadModule(StringRef Path, orc::ThreadSafeContext TSCtx) {
    SMDiagnostic Err;
    auto M = parseIRFile(Path, Err, *TSCtx.getContext());
    if (!M) {
      std::string ErrMsg;
      {
        raw_string_ostream ErrMsgStream(ErrMsg);
        Err.print("lli", ErrMsgStream);
      }
      return make_error<StringError>(std::move(ErrMsg), inconvertibleErrorCode());
    }
  
    if (EnableCacheManager)
      M->setModuleIdentifier("file:" + M->getModuleIdentifier());
  
    return orc::ThreadSafeModule(std::move(M), std::move(TSCtx));
  }
  
  int runOrcJIT(const char *ProgName) {
    // Start setting up the JIT environment.
  
    // Parse the main module.
    orc::ThreadSafeContext TSCtx(std::make_unique<LLVMContext>());
    auto MainModule = ExitOnErr(loadModule(InputFile, TSCtx));
  
    // Get TargetTriple and DataLayout from the main module if they're explicitly
    // set.
    Optional<Triple> TT;
    Optional<DataLayout> DL;
    MainModule.withModuleDo([&](Module &M) {
        if (!M.getTargetTriple().empty())
          TT = Triple(M.getTargetTriple());
        if (!M.getDataLayout().isDefault())
          DL = M.getDataLayout();
      });
  
    orc::LLLazyJITBuilder Builder;
  
    Builder.setJITTargetMachineBuilder(
        TT ? orc::JITTargetMachineBuilder(*TT)
           : ExitOnErr(orc::JITTargetMachineBuilder::detectHost()));
  
    TT = Builder.getJITTargetMachineBuilder()->getTargetTriple();
    if (DL)
      Builder.setDataLayout(DL);
  
    if (!codegen::getMArch().empty())
      Builder.getJITTargetMachineBuilder()->getTargetTriple().setArchName(
          codegen::getMArch());
  
    Builder.getJITTargetMachineBuilder()
        ->setCPU(codegen::getCPUStr())
        .addFeatures(codegen::getFeatureList())
        .setRelocationModel(codegen::getExplicitRelocModel())
        .setCodeModel(codegen::getExplicitCodeModel());
  
    // FIXME: Setting a dummy call-through manager in non-lazy mode prevents the
    // JIT builder to instantiate a default (which would fail with an error for
    // unsupported architectures).
    if (UseJITKind != JITKind::OrcLazy) {
      auto ES = std::make_unique<orc::ExecutionSession>(
          ExitOnErr(orc::SelfExecutorProcessControl::Create()));
      Builder.setLazyCallthroughManager(
          std::make_unique<orc::LazyCallThroughManager>(*ES, 0, nullptr));
      Builder.setExecutionSession(std::move(ES));
    }
  
    Builder.setLazyCompileFailureAddr(
        pointerToJITTargetAddress(exitOnLazyCallThroughFailure));
    Builder.setNumCompileThreads(LazyJITCompileThreads);
  
    // If the object cache is enabled then set a custom compile function
    // creator to use the cache.
    std::unique_ptr<LLIObjectCache> CacheManager;
    if (EnableCacheManager) {
  
      CacheManager = std::make_unique<LLIObjectCache>(ObjectCacheDir);
  
      Builder.setCompileFunctionCreator(
        [&](orc::JITTargetMachineBuilder JTMB)
              -> Expected<std::unique_ptr<orc::IRCompileLayer::IRCompiler>> {
          if (LazyJITCompileThreads > 0)
            return std::make_unique<orc::ConcurrentIRCompiler>(std::move(JTMB),
                                                          CacheManager.get());
  
          auto TM = JTMB.createTargetMachine();
          if (!TM)
            return TM.takeError();
  
          return std::make_unique<orc::TMOwningSimpleCompiler>(std::move(*TM),
                                                          CacheManager.get());
        });
    }
  
    // Set up LLJIT platform.
    {
      LLJITPlatform P = Platform;
      if (P == LLJITPlatform::DetectHost)
        P = LLJITPlatform::GenericIR;
  
      switch (P) {
      case LLJITPlatform::GenericIR:
        // Nothing to do: LLJITBuilder will use this by default.
        break;
      case LLJITPlatform::Inactive:
        Builder.setPlatformSetUp(orc::setUpInactivePlatform);
        break;
      default:
        llvm_unreachable("Unrecognized platform value");
      }
    }
  
    std::unique_ptr<orc::ExecutorProcessControl> EPC = nullptr;
    if (JITLinker == JITLinkerKind::JITLink) {
      EPC = ExitOnErr(orc::SelfExecutorProcessControl::Create(
          std::make_shared<orc::SymbolStringPool>()));
  
      Builder.setObjectLinkingLayerCreator([&EPC](orc::ExecutionSession &ES,
                                                  const Triple &) {
        auto L = std::make_unique<orc::ObjectLinkingLayer>(ES, EPC->getMemMgr());
        L->addPlugin(std::make_unique<orc::EHFrameRegistrationPlugin>(
            ES, ExitOnErr(orc::EPCEHFrameRegistrar::Create(ES))));
        L->addPlugin(std::make_unique<orc::DebugObjectManagerPlugin>(
            ES, ExitOnErr(orc::createJITLoaderGDBRegistrar(ES))));
        return L;
      });
    }
  
    auto J = ExitOnErr(Builder.create());
  
    auto *ObjLayer = &J->getObjLinkingLayer();
    if (auto *RTDyldObjLayer = dyn_cast<orc::RTDyldObjectLinkingLayer>(ObjLayer))
      RTDyldObjLayer->registerJITEventListener(
          *JITEventListener::createGDBRegistrationListener());
  
    if (PerModuleLazy)
      J->setPartitionFunction(orc::CompileOnDemandLayer::compileWholeModule);
  
    auto Dump = createDebugDumper();
  
    J->getIRTransformLayer().setTransform(
        [&](orc::ThreadSafeModule TSM,
            const orc::MaterializationResponsibility &R) {
          TSM.withModuleDo([&](Module &M) {
            if (verifyModule(M, &dbgs())) {
              dbgs() << "Bad module: " << &M << "\n";
              exit(1);
            }
            Dump(M);
          });
          return TSM;
        });
  
    orc::MangleAndInterner Mangle(J->getExecutionSession(), J->getDataLayout());
  
    // Unless they've been explicitly disabled, make process symbols available to
    // JIT'd code.
    if (!NoProcessSymbols)
      J->getMainJITDylib().addGenerator(
          ExitOnErr(orc::DynamicLibrarySearchGenerator::GetForCurrentProcess(
              J->getDataLayout().getGlobalPrefix(),
              [MainName = Mangle("main")](const orc::SymbolStringPtr &Name) {
                return Name != MainName;
              })));
  
    if (GenerateBuiltinFunctions.size() > 0)
      J->getMainJITDylib().addGenerator(
          std::make_unique<LLIBuiltinFunctionGenerator>(GenerateBuiltinFunctions,
                                                        Mangle));
  
    // Regular modules are greedy: They materialize as a whole and trigger
    // materialization for all required symbols recursively. Lazy modules go
    // through partitioning and they replace outgoing calls with reexport stubs
    // that resolve on call-through.
    auto AddModule = [&](orc::JITDylib &JD, orc::ThreadSafeModule M) {
      return UseJITKind == JITKind::OrcLazy ? J->addLazyIRModule(JD, std::move(M))
                                            : J->addIRModule(JD, std::move(M));
    };
  
    // Add the main module.
    ExitOnErr(AddModule(J->getMainJITDylib(), std::move(MainModule)));
  
    // Create JITDylibs and add any extra modules.
    {
      // Create JITDylibs, keep a map from argument index to dylib. We will use
      // -extra-module argument indexes to determine what dylib to use for each
      // -extra-module.
      std::map<unsigned, orc::JITDylib *> IdxToDylib;
      IdxToDylib[0] = &J->getMainJITDylib();
      for (auto JDItr = JITDylibs.begin(), JDEnd = JITDylibs.end();
           JDItr != JDEnd; ++JDItr) {
        orc::JITDylib *JD = J->getJITDylibByName(*JDItr);
        if (!JD) {
          JD = &ExitOnErr(J->createJITDylib(*JDItr));
          J->getMainJITDylib().addToLinkOrder(*JD);
          JD->addToLinkOrder(J->getMainJITDylib());
        }
        IdxToDylib[JITDylibs.getPosition(JDItr - JITDylibs.begin())] = JD;
      }
  
      for (auto EMItr = ExtraModules.begin(), EMEnd = ExtraModules.end();
           EMItr != EMEnd; ++EMItr) {
        auto M = ExitOnErr(loadModule(*EMItr, TSCtx));
  
        auto EMIdx = ExtraModules.getPosition(EMItr - ExtraModules.begin());
        assert(EMIdx != 0 && "ExtraModule should have index > 0");
        auto JDItr = std::prev(IdxToDylib.lower_bound(EMIdx));
        auto &JD = *JDItr->second;
        ExitOnErr(AddModule(JD, std::move(M)));
      }
  
      for (auto EAItr = ExtraArchives.begin(), EAEnd = ExtraArchives.end();
           EAItr != EAEnd; ++EAItr) {
        auto EAIdx = ExtraArchives.getPosition(EAItr - ExtraArchives.begin());
        assert(EAIdx != 0 && "ExtraArchive should have index > 0");
        auto JDItr = std::prev(IdxToDylib.lower_bound(EAIdx));
        auto &JD = *JDItr->second;
        JD.addGenerator(ExitOnErr(orc::StaticLibraryDefinitionGenerator::Load(
            J->getObjLinkingLayer(), EAItr->c_str(), *TT)));
      }
    }
  
    // Add the objects.
    for (auto &ObjPath : ExtraObjects) {
      auto Obj = ExitOnErr(errorOrToExpected(MemoryBuffer::getFile(ObjPath)));
      ExitOnErr(J->addObjectFile(std::move(Obj)));
    }
  
    // Run any static constructors.
    ExitOnErr(J->initialize(J->getMainJITDylib()));
  
    // Run any -thread-entry points.
    std::vector<std::thread> AltEntryThreads;
    for (auto &ThreadEntryPoint : ThreadEntryPoints) {
      auto EntryPointSym = ExitOnErr(J->lookup(ThreadEntryPoint));
      typedef void (*EntryPointPtr)();
      auto EntryPoint =
        reinterpret_cast<EntryPointPtr>(static_cast<uintptr_t>(EntryPointSym.getAddress()));
      AltEntryThreads.push_back(std::thread([EntryPoint]() { EntryPoint(); }));
    }
  
    // Resolve and run the main function.
    JITEvaluatedSymbol MainSym = ExitOnErr(J->lookup(EntryFunc));
    int Result;
  
    if (EPC) {
      // ExecutorProcessControl-based execution with JITLink.
      Result = ExitOnErr(
          EPC->runAsMain(orc::ExecutorAddr(MainSym.getAddress()), InputArgv));
    } else {
      // Manual in-process execution with RuntimeDyld.
      using MainFnTy = int(int, char *[]);
      auto MainFn = jitTargetAddressToFunction<MainFnTy *>(MainSym.getAddress());
      Result = orc::runAsMain(MainFn, InputArgv, StringRef(InputFile));
    }
  
    // Wait for -entry-point threads.
    for (auto &AltEntryThread : AltEntryThreads)
      AltEntryThread.join();
  
    // Run destructors.
    ExitOnErr(J->deinitialize(J->getMainJITDylib()));
  
    return Result;
  }
  
  void disallowOrcOptions() {
    // Make sure nobody used an orc-lazy specific option accidentally.
  
    if (LazyJITCompileThreads != 0) {
      errs() << "-compile-threads requires -jit-kind=orc-lazy\n";
      exit(1);
    }
  
    if (!ThreadEntryPoints.empty()) {
      errs() << "-thread-entry requires -jit-kind=orc-lazy\n";
      exit(1);
    }
  
    if (PerModuleLazy) {
      errs() << "-per-module-lazy requires -jit-kind=orc-lazy\n";
      exit(1);
    }
  }
  
  Expected<std::unique_ptr<orc::ExecutorProcessControl>> launchRemote() {
  #ifndef LLVM_ON_UNIX
    llvm_unreachable("launchRemote not supported on non-Unix platforms");
  #else
    int PipeFD[2][2];
    pid_t ChildPID;
  
    // Create two pipes.
    if (pipe(PipeFD[0]) != 0 || pipe(PipeFD[1]) != 0)
      perror("Error creating pipe: ");
  
    ChildPID = fork();
  
    if (ChildPID == 0) {
      // In the child...
  
      // Close the parent ends of the pipes
      close(PipeFD[0][1]);
      close(PipeFD[1][0]);
  
  
      // Execute the child process.
      std::unique_ptr<char[]> ChildPath, ChildIn, ChildOut;
      {
        ChildPath.reset(new char[ChildExecPath.size() + 1]);
        std::copy(ChildExecPath.begin(), ChildExecPath.end(), &ChildPath[0]);
        ChildPath[ChildExecPath.size()] = '\0';
        std::string ChildInStr = utostr(PipeFD[0][0]);
        ChildIn.reset(new char[ChildInStr.size() + 1]);
        std::copy(ChildInStr.begin(), ChildInStr.end(), &ChildIn[0]);
        ChildIn[ChildInStr.size()] = '\0';
        std::string ChildOutStr = utostr(PipeFD[1][1]);
        ChildOut.reset(new char[ChildOutStr.size() + 1]);
        std::copy(ChildOutStr.begin(), ChildOutStr.end(), &ChildOut[0]);
        ChildOut[ChildOutStr.size()] = '\0';
      }
  
      char * const args[] = { &ChildPath[0], &ChildIn[0], &ChildOut[0], nullptr };
      int rc = execv(ChildExecPath.c_str(), args);
      if (rc != 0)
        perror("Error executing child process: ");
      llvm_unreachable("Error executing child process");
    }
    // else we're the parent...
  
    // Close the child ends of the pipes
    close(PipeFD[0][0]);
    close(PipeFD[1][1]);
  
    // Return a SimpleRemoteEPC instance connected to our end of the pipes.
    return orc::SimpleRemoteEPC::Create<orc::FDSimpleRemoteEPCTransport>(
        std::make_unique<llvm::orc::InPlaceTaskDispatcher>(),
        llvm::orc::SimpleRemoteEPC::Setup(), PipeFD[1][0], PipeFD[0][1]);
  #endif
  }
  