fix ya.make

3 files changed, 1265 insertions, 0 deletions

diff --git a/contrib/libs/llvm12/tools/lli/ChildTarget/ChildTarget.cpp b/contrib/libs/llvm12/tools/lli/ChildTarget/ChildTarget.cpp
new file mode 100644
index 0000000000..5772baca1d
--- /dev/null
+++ b/contrib/libs/llvm12/tools/lli/ChildTarget/ChildTarget.cpp
@@ -0,0 +1,69 @@
+#include "llvm/ExecutionEngine/Orc/OrcABISupport.h"
+#include "llvm/ExecutionEngine/Orc/OrcRemoteTargetServer.h"
+#include "llvm/ExecutionEngine/Orc/Shared/FDRawByteChannel.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/DynamicLibrary.h"
+#include "llvm/Support/Process.h"
+#include <sstream>
+
+#include "../RemoteJITUtils.h"
+
+using namespace llvm;
+using namespace llvm::orc;
+using namespace llvm::sys;
+
+#ifdef __x86_64__
+typedef OrcX86_64_SysV HostOrcArch;
+#else
+typedef OrcGenericABI HostOrcArch;
+#endif
+
+ExitOnError ExitOnErr;
+
+int main(int argc, char *argv[]) {
+
+  if (argc != 3) {
+    errs() << "Usage: " << argv[0] << " <input fd> <output fd>\n";
+    return 1;
+  }
+
+  ExitOnErr.setBanner(std::string(argv[0]) + ":");
+
+  int InFD;
+  int OutFD;
+  {
+    std::istringstream InFDStream(argv[1]), OutFDStream(argv[2]);
+    InFDStream >> InFD;
+    OutFDStream >> OutFD;
+  }
+
+  if (sys::DynamicLibrary::LoadLibraryPermanently(nullptr)) {
+    errs() << "Error loading program symbols.\n";
+    return 1;
+  }
+
+  auto SymbolLookup = [](const std::string &Name) {
+    return RTDyldMemoryManager::getSymbolAddressInProcess(Name);
+  };
+
+  auto RegisterEHFrames = [](uint8_t *Addr, uint32_t Size) {
+    RTDyldMemoryManager::registerEHFramesInProcess(Addr, Size);
+  };
+
+  auto DeregisterEHFrames = [](uint8_t *Addr, uint32_t Size) {
+    RTDyldMemoryManager::deregisterEHFramesInProcess(Addr, Size);
+  };
+
+  shared::FDRawByteChannel Channel(InFD, OutFD);
+  typedef remote::OrcRemoteTargetServer<shared::FDRawByteChannel, HostOrcArch>
+      JITServer;
+  JITServer Server(Channel, SymbolLookup, RegisterEHFrames, DeregisterEHFrames);
+
+  while (!Server.receivedTerminate())
+    ExitOnErr(Server.handleOne());
+
+  close(InFD);
+  close(OutFD);
+
+  return 0;
+}
diff --git a/contrib/libs/llvm12/tools/lli/RemoteJITUtils.h b/contrib/libs/llvm12/tools/lli/RemoteJITUtils.h
new file mode 100644
index 0000000000..cc8d034f62
--- /dev/null
+++ b/contrib/libs/llvm12/tools/lli/RemoteJITUtils.h
@@ -0,0 +1,125 @@
+//===-- RemoteJITUtils.h - Utilities for remote-JITing with LLI -*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Utilities for remote-JITing with LLI.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TOOLS_LLI_REMOTEJITUTILS_H
+#define LLVM_TOOLS_LLI_REMOTEJITUTILS_H
+
+#include "llvm/ExecutionEngine/Orc/Shared/FDRawByteChannel.h"
+#include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
+#include <mutex>
+
+#if !defined(_MSC_VER) && !defined(__MINGW32__)
+#include <unistd.h>
+#else
+#include <io.h>
+#endif
+
+// launch the remote process (see lli.cpp) and return a channel to it.
+std::unique_ptr<llvm::orc::shared::FDRawByteChannel> launchRemote();
+
+namespace llvm {
+
+// ForwardingMM - Adapter to connect MCJIT to Orc's Remote
+// memory manager.
+class ForwardingMemoryManager : public llvm::RTDyldMemoryManager {
+public:
+  void setMemMgr(std::unique_ptr<RuntimeDyld::MemoryManager> MemMgr) {
+    this->MemMgr = std::move(MemMgr);
+  }
+
+  void setResolver(std::shared_ptr<LegacyJITSymbolResolver> Resolver) {
+    this->Resolver = std::move(Resolver);
+  }
+
+  uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
+                               unsigned SectionID,
+                               StringRef SectionName) override {
+    return MemMgr->allocateCodeSection(Size, Alignment, SectionID, SectionName);
+  }
+
+  uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
+                               unsigned SectionID, StringRef SectionName,
+                               bool IsReadOnly) override {
+    return MemMgr->allocateDataSection(Size, Alignment, SectionID, SectionName,
+                                       IsReadOnly);
+  }
+
+  void reserveAllocationSpace(uintptr_t CodeSize, uint32_t CodeAlign,
+                              uintptr_t RODataSize, uint32_t RODataAlign,
+                              uintptr_t RWDataSize,
+                              uint32_t RWDataAlign) override {
+    MemMgr->reserveAllocationSpace(CodeSize, CodeAlign, RODataSize, RODataAlign,
+                                   RWDataSize, RWDataAlign);
+  }
+
+  bool needsToReserveAllocationSpace() override {
+    return MemMgr->needsToReserveAllocationSpace();
+  }
+
+  void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr,
+                        size_t Size) override {
+    MemMgr->registerEHFrames(Addr, LoadAddr, Size);
+  }
+
+  void deregisterEHFrames() override {
+    MemMgr->deregisterEHFrames();
+  }
+
+  bool finalizeMemory(std::string *ErrMsg = nullptr) override {
+    return MemMgr->finalizeMemory(ErrMsg);
+  }
+
+  void notifyObjectLoaded(RuntimeDyld &RTDyld,
+                          const object::ObjectFile &Obj) override {
+    MemMgr->notifyObjectLoaded(RTDyld, Obj);
+  }
+
+  // Don't hide the sibling notifyObjectLoaded from RTDyldMemoryManager.
+  using RTDyldMemoryManager::notifyObjectLoaded;
+
+  JITSymbol findSymbol(const std::string &Name) override {
+    return Resolver->findSymbol(Name);
+  }
+
+  JITSymbol
+  findSymbolInLogicalDylib(const std::string &Name) override {
+    return Resolver->findSymbolInLogicalDylib(Name);
+  }
+
+private:
+  std::unique_ptr<RuntimeDyld::MemoryManager> MemMgr;
+  std::shared_ptr<LegacyJITSymbolResolver> Resolver;
+};
+
+template <typename RemoteT>
+class RemoteResolver : public LegacyJITSymbolResolver {
+public:
+
+  RemoteResolver(RemoteT &R) : R(R) {}
+
+  JITSymbol findSymbol(const std::string &Name) override {
+    if (auto Addr = R.getSymbolAddress(Name))
+      return JITSymbol(*Addr, JITSymbolFlags::Exported);
+    else
+      return Addr.takeError();
+  }
+
+  JITSymbol findSymbolInLogicalDylib(const std::string &Name) override {
+    return nullptr;
+  }
+
+public:
+  RemoteT &R;
+};
+}
+
+#endif
diff --git a/contrib/libs/llvm12/tools/lli/lli.cpp b/contrib/libs/llvm12/tools/lli/lli.cpp
new file mode 100644
index 0000000000..70c8381269
--- /dev/null
+++ b/contrib/libs/llvm12/tools/lli/lli.cpp
@@ -0,0 +1,1071 @@
+//===- 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 "RemoteJITUtils.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/MCJIT.h"
+#include "llvm/ExecutionEngine/ObjectCache.h"
+#include "llvm/ExecutionEngine/Orc/DebugUtils.h"
+#include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"
+#include "llvm/ExecutionEngine/Orc/JITTargetMachineBuilder.h"
+#include "llvm/ExecutionEngine/Orc/LLJIT.h"
+#include "llvm/ExecutionEngine/Orc/MachOPlatform.h"
+#include "llvm/ExecutionEngine/Orc/OrcRemoteTargetClient.h"
+#include "llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.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>
+
+#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, OrcLazy };
+
+  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::MCJIT),
+      cl::values(clEnumValN(JITKind::MCJIT, "mcjit", "MCJIT"),
+                 clEnumValN(JITKind::OrcLazy, "orc-lazy",
+                            "Orc-based lazy JIT.")));
+
+  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 { DetectHost, GenericIR, MachO };
+
+  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::MachO, "MachO",
+                                     "Use LLJITMachOPlatform")),
+               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);
+
+  ExitOnError ExitOnErr;
+}
+
+//===----------------------------------------------------------------------===//
+// 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, -1, 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);
+#if defined(_WIN32)
+    // Transform "X:\foo" => "/X\foo" for convenience.
+    if (isalpha(CacheSubdir[0]) && CacheSubdir[1] == ':') {
+      CacheSubdir[1] = CacheSubdir[0];
+      CacheSubdir[0] = '/';
+    }
+#endif
+
+    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.");
+}
+
+LLVM_ATTRIBUTE_NORETURN
+static void reportError(SMDiagnostic Err, const char *ProgName) {
+  Err.print(ProgName, errs());
+  exit(1);
+}
+
+Error loadDylibs();
+int runOrcLazyJIT(const char *ProgName);
+void disallowOrcOptions();
+
+//===----------------------------------------------------------------------===//
+// 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::OrcLazy)
+    return runOrcLazyJIT(argv[0]);
+  else
+    disallowOrcOptions();
+
+  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
+  }
+
+  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.
+
+    // Lanch the remote process and get a channel to it.
+    std::unique_ptr<orc::shared::FDRawByteChannel> C = launchRemote();
+    if (!C) {
+      WithColor::error(errs(), argv[0]) << "failed to launch remote JIT.\n";
+      exit(1);
+    }
+
+    // Create a remote target client running over the channel.
+    llvm::orc::ExecutionSession ES;
+    ES.setErrorReporter([&](Error Err) { ExitOnErr(std::move(Err)); });
+    typedef orc::remote::OrcRemoteTargetClient MyRemote;
+    auto R = ExitOnErr(MyRemote::Create(*C, ES));
+
+    // Create a remote memory manager.
+    auto RemoteMM = ExitOnErr(R->createRemoteMemoryManager());
+
+    // 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(
+        std::make_unique<RemoteResolver<MyRemote>>(*R));
+
+    // Grab the target address of the JIT'd main function on the remote and call
+    // it.
+    // FIXME: argv and envp handling.
+    JITTargetAddress Entry = EE->getFunctionAddress(EntryFn->getName().str());
+    EE->finalizeObject();
+    LLVM_DEBUG(dbgs() << "Executing '" << EntryFn->getName() << "' at 0x"
+                      << format("%llx", Entry) << "\n");
+    Result = ExitOnErr(R->callIntVoid(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(R->terminateSession());
+  }
+
+  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_Text);
+      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 runOrcLazyJIT(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());
+
+  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) {
+      if (TT->isOSBinFormatMachO())
+        P = LLJITPlatform::MachO;
+      else
+        P = LLJITPlatform::GenericIR;
+    }
+
+    switch (P) {
+    case LLJITPlatform::GenericIR:
+      // Nothing to do: LLJITBuilder will use this by default.
+      break;
+    case LLJITPlatform::MachO:
+      Builder.setPlatformSetUp(orc::setUpMachOPlatform);
+      ExitOnErr(orc::enableObjCRegistration("libobjc.dylib"));
+      break;
+    default:
+      llvm_unreachable("Unrecognized platform value");
+    }
+  }
+
+  auto J = ExitOnErr(Builder.create());
+
+  if (TT->isOSBinFormatELF())
+    static_cast<llvm::orc::RTDyldObjectLinkingLayer &>(J->getObjLinkingLayer())
+        .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;
+            })));
+
+  // Add the main module.
+  ExitOnErr(J->addLazyIRModule(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(J->addLazyIRModule(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(); }));
+  }
+
+  // Run main.
+  auto MainSym = ExitOnErr(J->lookup("main"));
+
+  typedef int (*MainFnPtr)(int, char *[]);
+  auto Result = orc::runAsMain(
+      jitTargetAddressToFunction<MainFnPtr>(MainSym.getAddress()), 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);
+  }
+}
+
+std::unique_ptr<orc::shared::FDRawByteChannel> 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 an RPC channel connected to our end of the pipes.
+  return std::make_unique<orc::shared::FDRawByteChannel>(PipeFD[1][0],
+                                                         PipeFD[0][1]);
+#endif
+}