tools/lli/lli.cpp

   1 //===- lli.cpp - LLVM Interpreter / Dynamic compiler ----------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This utility provides a simple wrapper around the LLVM Execution Engines,
  10 // which allow the direct execution of LLVM programs through a Just-In-Time
  11 // compiler, or through an interpreter if no JIT is available for this platform.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "RemoteJITUtils.h"
  16 #include "llvm/ADT/StringExtras.h"
  17 #include "llvm/ADT/Triple.h"
  18 #include "llvm/Bitcode/BitcodeReader.h"
  19 #include "llvm/CodeGen/CommandFlags.inc"
  20 #include "llvm/CodeGen/LinkAllCodegenComponents.h"
  21 #include "llvm/Config/llvm-config.h"
  22 #include "llvm/ExecutionEngine/GenericValue.h"
  23 #include "llvm/ExecutionEngine/Interpreter.h"
  24 #include "llvm/ExecutionEngine/JITEventListener.h"
  25 #include "llvm/ExecutionEngine/MCJIT.h"
  26 #include "llvm/ExecutionEngine/ObjectCache.h"
  27 #include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"
  28 #include "llvm/ExecutionEngine/Orc/JITTargetMachineBuilder.h"
  29 #include "llvm/ExecutionEngine/Orc/LLJIT.h"
  30 #include "llvm/ExecutionEngine/Orc/OrcRemoteTargetClient.h"
  31 #include "llvm/ExecutionEngine/OrcMCJITReplacement.h"
  32 #include "llvm/ExecutionEngine/SectionMemoryManager.h"
  33 #include "llvm/IR/IRBuilder.h"
  34 #include "llvm/IR/LLVMContext.h"
  35 #include "llvm/IR/Module.h"
  36 #include "llvm/IR/Type.h"
  37 #include "llvm/IR/Verifier.h"
  38 #include "llvm/IRReader/IRReader.h"
  39 #include "llvm/Object/Archive.h"
  40 #include "llvm/Object/ObjectFile.h"
  41 #include "llvm/Support/CommandLine.h"
  42 #include "llvm/Support/Debug.h"
  43 #include "llvm/Support/DynamicLibrary.h"
  44 #include "llvm/Support/Format.h"
  45 #include "llvm/Support/InitLLVM.h"
  46 #include "llvm/Support/ManagedStatic.h"
  47 #include "llvm/Support/MathExtras.h"
  48 #include "llvm/Support/Memory.h"
  49 #include "llvm/Support/MemoryBuffer.h"
  50 #include "llvm/Support/Path.h"
  51 #include "llvm/Support/PluginLoader.h"
  52 #include "llvm/Support/Process.h"
  53 #include "llvm/Support/Program.h"
  54 #include "llvm/Support/SourceMgr.h"
  55 #include "llvm/Support/TargetSelect.h"
  56 #include "llvm/Support/WithColor.h"
  57 #include "llvm/Support/raw_ostream.h"
  58 #include "llvm/Transforms/Instrumentation.h"
  59 #include <cerrno>
  60
  61 #ifdef __CYGWIN__
  62 #include <cygwin/version.h>
  63 #if defined(CYGWIN_VERSION_DLL_MAJOR) && CYGWIN_VERSION_DLL_MAJOR<1007
  64 #define DO_NOTHING_ATEXIT 1
  65 #endif
  66 #endif
  67
  68 using namespace llvm;
  69
  70 #define DEBUG_TYPE "lli"
  71
  72 namespace {
  73
  74   enum class JITKind { MCJIT, OrcMCJITReplacement, OrcLazy };
  75
  76   cl::opt<std::string>
  77   InputFile(cl::desc("<input bitcode>"), cl::Positional, cl::init("-"));
  78
  79   cl::list<std::string>
  80   InputArgv(cl::ConsumeAfter, cl::desc("<program arguments>..."));
  81
  82   cl::opt<bool> ForceInterpreter("force-interpreter",
  83                                  cl::desc("Force interpretation: disable JIT"),
  84                                  cl::init(false));
  85
  86   cl::opt<JITKind> UseJITKind("jit-kind",
  87                               cl::desc("Choose underlying JIT kind."),
  88                               cl::init(JITKind::MCJIT),
  89                               cl::values(
  90                                 clEnumValN(JITKind::MCJIT, "mcjit",
  91                                            "MCJIT"),
  92                                 clEnumValN(JITKind::OrcMCJITReplacement,
  93                                            "orc-mcjit",
  94                                            "Orc-based MCJIT replacement"),
  95                                 clEnumValN(JITKind::OrcLazy,
  96                                            "orc-lazy",
  97                                            "Orc-based lazy JIT.")));
  98
  99   cl::opt<unsigned>
 100   LazyJITCompileThreads("compile-threads",
 101                         cl::desc("Choose the number of compile threads "
 102                                  "(jit-kind=orc-lazy only)"),
 103                         cl::init(0));
 104
 105   cl::list<std::string>
 106   ThreadEntryPoints("thread-entry",
 107                     cl::desc("calls the given entry-point on a new thread "
 108                              "(jit-kind=orc-lazy only)"));
 109
 110   cl::opt<bool> PerModuleLazy(
 111       "per-module-lazy",
 112       cl::desc("Performs lazy compilation on whole module boundaries "
 113                "rather than individual functions"),
 114       cl::init(false));
 115
 116   cl::list<std::string>
 117       JITDylibs("jd",
 118                 cl::desc("Specifies the JITDylib to be used for any subsequent "
 119                          "-extra-module arguments."));
 120
 121   // The MCJIT supports building for a target address space separate from
 122   // the JIT compilation process. Use a forked process and a copying
 123   // memory manager with IPC to execute using this functionality.
 124   cl::opt<bool> RemoteMCJIT("remote-mcjit",
 125     cl::desc("Execute MCJIT'ed code in a separate process."),
 126     cl::init(false));
 127
 128   // Manually specify the child process for remote execution. This overrides
 129   // the simulated remote execution that allocates address space for child
 130   // execution. The child process will be executed and will communicate with
 131   // lli via stdin/stdout pipes.
 132   cl::opt<std::string>
 133   ChildExecPath("mcjit-remote-process",
 134                 cl::desc("Specify the filename of the process to launch "
 135                          "for remote MCJIT execution.  If none is specified,"
 136                          "\n\tremote execution will be simulated in-process."),
 137                 cl::value_desc("filename"), cl::init(""));
 138
 139   // Determine optimization level.
 140   cl::opt<char>
 141   OptLevel("O",
 142            cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
 143                     "(default = '-O2')"),
 144            cl::Prefix,
 145            cl::ZeroOrMore,
 146            cl::init(' '));
 147
 148   cl::opt<std::string>
 149   TargetTriple("mtriple", cl::desc("Override target triple for module"));
 150
 151   cl::opt<std::string>
 152   EntryFunc("entry-function",
 153             cl::desc("Specify the entry function (default = 'main') "
 154                      "of the executable"),
 155             cl::value_desc("function"),
 156             cl::init("main"));
 157
 158   cl::list<std::string>
 159   ExtraModules("extra-module",
 160          cl::desc("Extra modules to be loaded"),
 161          cl::value_desc("input bitcode"));
 162
 163   cl::list<std::string>
 164   ExtraObjects("extra-object",
 165          cl::desc("Extra object files to be loaded"),
 166          cl::value_desc("input object"));
 167
 168   cl::list<std::string>
 169   ExtraArchives("extra-archive",
 170          cl::desc("Extra archive files to be loaded"),
 171          cl::value_desc("input archive"));
 172
 173   cl::opt<bool>
 174   EnableCacheManager("enable-cache-manager",
 175         cl::desc("Use cache manager to save/load mdoules"),
 176         cl::init(false));
 177
 178   cl::opt<std::string>
 179   ObjectCacheDir("object-cache-dir",
 180                   cl::desc("Directory to store cached object files "
 181                            "(must be user writable)"),
 182                   cl::init(""));
 183
 184   cl::opt<std::string>
 185   FakeArgv0("fake-argv0",
 186             cl::desc("Override the 'argv[0]' value passed into the executing"
 187                      " program"), cl::value_desc("executable"));
 188
 189   cl::opt<bool>
 190   DisableCoreFiles("disable-core-files", cl::Hidden,
 191                    cl::desc("Disable emission of core files if possible"));
 192
 193   cl::opt<bool>
 194   NoLazyCompilation("disable-lazy-compilation",
 195                   cl::desc("Disable JIT lazy compilation"),
 196                   cl::init(false));
 197
 198   cl::opt<bool>
 199   GenerateSoftFloatCalls("soft-float",
 200     cl::desc("Generate software floating point library calls"),
 201     cl::init(false));
 202
 203   enum class DumpKind {
 204     NoDump,
 205     DumpFuncsToStdOut,
 206     DumpModsToStdOut,
 207     DumpModsToDisk
 208   };
 209
 210   cl::opt<DumpKind> OrcDumpKind(
 211       "orc-lazy-debug", cl::desc("Debug dumping for the orc-lazy JIT."),
 212       cl::init(DumpKind::NoDump),
 213       cl::values(clEnumValN(DumpKind::NoDump, "no-dump",
 214                             "Don't dump anything."),
 215                  clEnumValN(DumpKind::DumpFuncsToStdOut, "funcs-to-stdout",
 216                             "Dump function names to stdout."),
 217                  clEnumValN(DumpKind::DumpModsToStdOut, "mods-to-stdout",
 218                             "Dump modules to stdout."),
 219                  clEnumValN(DumpKind::DumpModsToDisk, "mods-to-disk",
 220                             "Dump modules to the current "
 221                             "working directory. (WARNING: "
 222                             "will overwrite existing files).")),
 223       cl::Hidden);
 224
 225   ExitOnError ExitOnErr;
 226 }
 227
 228 //===----------------------------------------------------------------------===//
 229 // Object cache
 230 //
 231 // This object cache implementation writes cached objects to disk to the
 232 // directory specified by CacheDir, using a filename provided in the module
 233 // descriptor. The cache tries to load a saved object using that path if the
 234 // file exists. CacheDir defaults to "", in which case objects are cached
 235 // alongside their originating bitcodes.
 236 //
 237 class LLIObjectCache : public ObjectCache {
 238 public:
 239   LLIObjectCache(const std::string& CacheDir) : CacheDir(CacheDir) {
 240     // Add trailing '/' to cache dir if necessary.
 241     if (!this->CacheDir.empty() &&
 242         this->CacheDir[this->CacheDir.size() - 1] != '/')
 243       this->CacheDir += '/';
 244   }
 245   ~LLIObjectCache() override {}
 246
 247   void notifyObjectCompiled(const Module *M, MemoryBufferRef Obj) override {
 248     const std::string &ModuleID = M->getModuleIdentifier();
 249     std::string CacheName;
 250     if (!getCacheFilename(ModuleID, CacheName))
 251       return;
 252     if (!CacheDir.empty()) { // Create user-defined cache dir.
 253       SmallString<128> dir(sys::path::parent_path(CacheName));
 254       sys::fs::create_directories(Twine(dir));
 255     }
 256     std::error_code EC;
 257     raw_fd_ostream outfile(CacheName, EC, sys::fs::F_None);
 258     outfile.write(Obj.getBufferStart(), Obj.getBufferSize());
 259     outfile.close();
 260   }
 261
 262   std::unique_ptr<MemoryBuffer> getObject(const Module* M) override {
 263     const std::string &ModuleID = M->getModuleIdentifier();
 264     std::string CacheName;
 265     if (!getCacheFilename(ModuleID, CacheName))
 266       return nullptr;
 267     // Load the object from the cache filename
 268     ErrorOr<std::unique_ptr<MemoryBuffer>> IRObjectBuffer =
 269         MemoryBuffer::getFile(CacheName, -1, false);
 270     // If the file isn't there, that's OK.
 271     if (!IRObjectBuffer)
 272       return nullptr;
 273     // MCJIT will want to write into this buffer, and we don't want that
 274     // because the file has probably just been mmapped.  Instead we make
 275     // a copy.  The filed-based buffer will be released when it goes
 276     // out of scope.
 277     return MemoryBuffer::getMemBufferCopy(IRObjectBuffer.get()->getBuffer());
 278   }
 279
 280 private:
 281   std::string CacheDir;
 282
 283   bool getCacheFilename(const std::string &ModID, std::string &CacheName) {
 284     std::string Prefix("file:");
 285     size_t PrefixLength = Prefix.length();
 286     if (ModID.substr(0, PrefixLength) != Prefix)
 287       return false;
 288         std::string CacheSubdir = ModID.substr(PrefixLength);
 289 #if defined(_WIN32)
 290         // Transform "X:\foo" => "/X\foo" for convenience.
 291         if (isalpha(CacheSubdir[0]) && CacheSubdir[1] == ':') {
 292           CacheSubdir[1] = CacheSubdir[0];
 293           CacheSubdir[0] = '/';
 294         }
 295 #endif
 296     CacheName = CacheDir + CacheSubdir;
 297     size_t pos = CacheName.rfind('.');
 298     CacheName.replace(pos, CacheName.length() - pos, ".o");
 299     return true;
 300   }
 301 };
 302
 303 // On Mingw and Cygwin, an external symbol named '__main' is called from the
 304 // generated 'main' function to allow static initialization.  To avoid linking
 305 // problems with remote targets (because lli's remote target support does not
 306 // currently handle external linking) we add a secondary module which defines
 307 // an empty '__main' function.
 308 static void addCygMingExtraModule(ExecutionEngine &EE, LLVMContext &Context,
 309                                   StringRef TargetTripleStr) {
 310   IRBuilder<> Builder(Context);
 311   Triple TargetTriple(TargetTripleStr);
 312
 313   // Create a new module.
 314   std::unique_ptr<Module> M = make_unique<Module>("CygMingHelper", Context);
 315   M->setTargetTriple(TargetTripleStr);
 316
 317   // Create an empty function named "__main".
 318   Type *ReturnTy;
 319   if (TargetTriple.isArch64Bit())
 320     ReturnTy = Type::getInt64Ty(Context);
 321   else
 322     ReturnTy = Type::getInt32Ty(Context);
 323   Function *Result =
 324       Function::Create(FunctionType::get(ReturnTy, {}, false),
 325                        GlobalValue::ExternalLinkage, "__main", M.get());
 326
 327   BasicBlock *BB = BasicBlock::Create(Context, "__main", Result);
 328   Builder.SetInsertPoint(BB);
 329   Value *ReturnVal = ConstantInt::get(ReturnTy, 0);
 330   Builder.CreateRet(ReturnVal);
 331
 332   // Add this new module to the ExecutionEngine.
 333   EE.addModule(std::move(M));
 334 }
 335
 336 CodeGenOpt::Level getOptLevel() {
 337   switch (OptLevel) {
 338   default:
 339     WithColor::error(errs(), "lli") << "invalid optimization level.\n";
 340     exit(1);
 341   case '0': return CodeGenOpt::None;
 342   case '1': return CodeGenOpt::Less;
 343   case ' ':
 344   case '2': return CodeGenOpt::Default;
 345   case '3': return CodeGenOpt::Aggressive;
 346   }
 347   llvm_unreachable("Unrecognized opt level.");
 348 }
 349
 350 LLVM_ATTRIBUTE_NORETURN
 351 static void reportError(SMDiagnostic Err, const char *ProgName) {
 352   Err.print(ProgName, errs());
 353   exit(1);
 354 }
 355
 356 int runOrcLazyJIT(const char *ProgName);
 357 void disallowOrcOptions();
 358
 359 //===----------------------------------------------------------------------===//
 360 // main Driver function
 361 //
 362 int main(int argc, char **argv, char * const *envp) {
 363   InitLLVM X(argc, argv);
 364
 365   if (argc > 1)
 366     ExitOnErr.setBanner(std::string(argv[0]) + ": ");
 367
 368   // If we have a native target, initialize it to ensure it is linked in and
 369   // usable by the JIT.
 370   InitializeNativeTarget();
 371   InitializeNativeTargetAsmPrinter();
 372   InitializeNativeTargetAsmParser();
 373
 374   cl::ParseCommandLineOptions(argc, argv,
 375                               "llvm interpreter & dynamic compiler\n");
 376
 377   // If the user doesn't want core files, disable them.
 378   if (DisableCoreFiles)
 379     sys::Process::PreventCoreFiles();
 380
 381   if (UseJITKind == JITKind::OrcLazy)
 382     return runOrcLazyJIT(argv[0]);
 383   else
 384     disallowOrcOptions();
 385
 386   LLVMContext Context;
 387
 388   // Load the bitcode...
 389   SMDiagnostic Err;
 390   std::unique_ptr<Module> Owner = parseIRFile(InputFile, Err, Context);
 391   Module *Mod = Owner.get();
 392   if (!Mod)
 393     reportError(Err, argv[0]);
 394
 395   if (EnableCacheManager) {
 396     std::string CacheName("file:");
 397     CacheName.append(InputFile);
 398     Mod->setModuleIdentifier(CacheName);
 399   }
 400
 401   // If not jitting lazily, load the whole bitcode file eagerly too.
 402   if (NoLazyCompilation) {
 403     // Use *argv instead of argv[0] to work around a wrong GCC warning.
 404     ExitOnError ExitOnErr(std::string(*argv) +
 405                           ": bitcode didn't read correctly: ");
 406     ExitOnErr(Mod->materializeAll());
 407   }
 408
 409   std::string ErrorMsg;
 410   EngineBuilder builder(std::move(Owner));
 411   builder.setMArch(MArch);
 412   builder.setMCPU(getCPUStr());
 413   builder.setMAttrs(getFeatureList());
 414   if (RelocModel.getNumOccurrences())
 415     builder.setRelocationModel(RelocModel);
 416   if (CMModel.getNumOccurrences())
 417     builder.setCodeModel(CMModel);
 418   builder.setErrorStr(&ErrorMsg);
 419   builder.setEngineKind(ForceInterpreter
 420                         ? EngineKind::Interpreter
 421                         : EngineKind::JIT);
 422   builder.setUseOrcMCJITReplacement(UseJITKind == JITKind::OrcMCJITReplacement);
 423
 424   // If we are supposed to override the target triple, do so now.
 425   if (!TargetTriple.empty())
 426     Mod->setTargetTriple(Triple::normalize(TargetTriple));
 427
 428   // Enable MCJIT if desired.
 429   RTDyldMemoryManager *RTDyldMM = nullptr;
 430   if (!ForceInterpreter) {
 431     if (RemoteMCJIT)
 432       RTDyldMM = new ForwardingMemoryManager();
 433     else
 434       RTDyldMM = new SectionMemoryManager();
 435
 436     // Deliberately construct a temp std::unique_ptr to pass in. Do not null out
 437     // RTDyldMM: We still use it below, even though we don't own it.
 438     builder.setMCJITMemoryManager(
 439       std::unique_ptr<RTDyldMemoryManager>(RTDyldMM));
 440   } else if (RemoteMCJIT) {
 441     WithColor::error(errs(), argv[0])
 442         << "remote process execution does not work with the interpreter.\n";
 443     exit(1);
 444   }
 445
 446   builder.setOptLevel(getOptLevel());
 447
 448   TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
 449   if (FloatABIForCalls != FloatABI::Default)
 450     Options.FloatABIType = FloatABIForCalls;
 451
 452   builder.setTargetOptions(Options);
 453
 454   std::unique_ptr<ExecutionEngine> EE(builder.create());
 455   if (!EE) {
 456     if (!ErrorMsg.empty())
 457       WithColor::error(errs(), argv[0])
 458           << "error creating EE: " << ErrorMsg << "\n";
 459     else
 460       WithColor::error(errs(), argv[0]) << "unknown error creating EE!\n";
 461     exit(1);
 462   }
 463
 464   std::unique_ptr<LLIObjectCache> CacheManager;
 465   if (EnableCacheManager) {
 466     CacheManager.reset(new LLIObjectCache(ObjectCacheDir));
 467     EE->setObjectCache(CacheManager.get());
 468   }
 469
 470   // Load any additional modules specified on the command line.
 471   for (unsigned i = 0, e = ExtraModules.size(); i != e; ++i) {
 472     std::unique_ptr<Module> XMod = parseIRFile(ExtraModules[i], Err, Context);
 473     if (!XMod)
 474       reportError(Err, argv[0]);
 475     if (EnableCacheManager) {
 476       std::string CacheName("file:");
 477       CacheName.append(ExtraModules[i]);
 478       XMod->setModuleIdentifier(CacheName);
 479     }
 480     EE->addModule(std::move(XMod));
 481   }
 482
 483   for (unsigned i = 0, e = ExtraObjects.size(); i != e; ++i) {
 484     Expected<object::OwningBinary<object::ObjectFile>> Obj =
 485         object::ObjectFile::createObjectFile(ExtraObjects[i]);
 486     if (!Obj) {
 487       // TODO: Actually report errors helpfully.
 488       consumeError(Obj.takeError());
 489       reportError(Err, argv[0]);
 490     }
 491     object::OwningBinary<object::ObjectFile> &O = Obj.get();
 492     EE->addObjectFile(std::move(O));
 493   }
 494
 495   for (unsigned i = 0, e = ExtraArchives.size(); i != e; ++i) {
 496     ErrorOr<std::unique_ptr<MemoryBuffer>> ArBufOrErr =
 497         MemoryBuffer::getFileOrSTDIN(ExtraArchives[i]);
 498     if (!ArBufOrErr)
 499       reportError(Err, argv[0]);
 500     std::unique_ptr<MemoryBuffer> &ArBuf = ArBufOrErr.get();
 501
 502     Expected<std::unique_ptr<object::Archive>> ArOrErr =
 503         object::Archive::create(ArBuf->getMemBufferRef());
 504     if (!ArOrErr) {
 505       std::string Buf;
 506       raw_string_ostream OS(Buf);
 507       logAllUnhandledErrors(ArOrErr.takeError(), OS);
 508       OS.flush();
 509       errs() << Buf;
 510       exit(1);
 511     }
 512     std::unique_ptr<object::Archive> &Ar = ArOrErr.get();
 513
 514     object::OwningBinary<object::Archive> OB(std::move(Ar), std::move(ArBuf));
 515
 516     EE->addArchive(std::move(OB));
 517   }
 518
 519   // If the target is Cygwin/MingW and we are generating remote code, we
 520   // need an extra module to help out with linking.
 521   if (RemoteMCJIT && Triple(Mod->getTargetTriple()).isOSCygMing()) {
 522     addCygMingExtraModule(*EE, Context, Mod->getTargetTriple());
 523   }
 524
 525   // The following functions have no effect if their respective profiling
 526   // support wasn't enabled in the build configuration.
 527   EE->RegisterJITEventListener(
 528                 JITEventListener::createOProfileJITEventListener());
 529   EE->RegisterJITEventListener(
 530                 JITEventListener::createIntelJITEventListener());
 531   if (!RemoteMCJIT)
 532     EE->RegisterJITEventListener(
 533                 JITEventListener::createPerfJITEventListener());
 534
 535   if (!NoLazyCompilation && RemoteMCJIT) {
 536     WithColor::warning(errs(), argv[0])
 537         << "remote mcjit does not support lazy compilation\n";
 538     NoLazyCompilation = true;
 539   }
 540   EE->DisableLazyCompilation(NoLazyCompilation);
 541
 542   // If the user specifically requested an argv[0] to pass into the program,
 543   // do it now.
 544   if (!FakeArgv0.empty()) {
 545     InputFile = static_cast<std::string>(FakeArgv0);
 546   } else {
 547     // Otherwise, if there is a .bc suffix on the executable strip it off, it
 548     // might confuse the program.
 549     if (StringRef(InputFile).endswith(".bc"))
 550       InputFile.erase(InputFile.length() - 3);
 551   }
 552
 553   // Add the module's name to the start of the vector of arguments to main().
 554   InputArgv.insert(InputArgv.begin(), InputFile);
 555
 556   // Call the main function from M as if its signature were:
 557   //   int main (int argc, char **argv, const char **envp)
 558   // using the contents of Args to determine argc & argv, and the contents of
 559   // EnvVars to determine envp.
 560   //
 561   Function *EntryFn = Mod->getFunction(EntryFunc);
 562   if (!EntryFn) {
 563     WithColor::error(errs(), argv[0])
 564         << '\'' << EntryFunc << "\' function not found in module.\n";
 565     return -1;
 566   }
 567
 568   // Reset errno to zero on entry to main.
 569   errno = 0;
 570
 571   int Result = -1;
 572
 573   // Sanity check use of remote-jit: LLI currently only supports use of the
 574   // remote JIT on Unix platforms.
 575   if (RemoteMCJIT) {
 576 #ifndef LLVM_ON_UNIX
 577     WithColor::warning(errs(), argv[0])
 578         << "host does not support external remote targets.\n";
 579     WithColor::note() << "defaulting to local execution\n";
 580     return -1;
 581 #else
 582     if (ChildExecPath.empty()) {
 583       WithColor::error(errs(), argv[0])
 584           << "-remote-mcjit requires -mcjit-remote-process.\n";
 585       exit(1);
 586     } else if (!sys::fs::can_execute(ChildExecPath)) {
 587       WithColor::error(errs(), argv[0])
 588           << "unable to find usable child executable: '" << ChildExecPath
 589           << "'\n";
 590       return -1;
 591     }
 592 #endif
 593   }
 594
 595   if (!RemoteMCJIT) {
 596     // If the program doesn't explicitly call exit, we will need the Exit
 597     // function later on to make an explicit call, so get the function now.
 598     FunctionCallee Exit = Mod->getOrInsertFunction(
 599         "exit", Type::getVoidTy(Context), Type::getInt32Ty(Context));
 600
 601     // Run static constructors.
 602     if (!ForceInterpreter) {
 603       // Give MCJIT a chance to apply relocations and set page permissions.
 604       EE->finalizeObject();
 605     }
 606     EE->runStaticConstructorsDestructors(false);
 607
 608     // Trigger compilation separately so code regions that need to be
 609     // invalidated will be known.
 610     (void)EE->getPointerToFunction(EntryFn);
 611     // Clear instruction cache before code will be executed.
 612     if (RTDyldMM)
 613       static_cast<SectionMemoryManager*>(RTDyldMM)->invalidateInstructionCache();
 614
 615     // Run main.
 616     Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
 617
 618     // Run static destructors.
 619     EE->runStaticConstructorsDestructors(true);
 620
 621     // If the program didn't call exit explicitly, we should call it now.
 622     // This ensures that any atexit handlers get called correctly.
 623     if (Function *ExitF =
 624             dyn_cast<Function>(Exit.getCallee()->stripPointerCasts())) {
 625       if (ExitF->getFunctionType() == Exit.getFunctionType()) {
 626         std::vector<GenericValue> Args;
 627         GenericValue ResultGV;
 628         ResultGV.IntVal = APInt(32, Result);
 629         Args.push_back(ResultGV);
 630         EE->runFunction(ExitF, Args);
 631         WithColor::error(errs(), argv[0])
 632             << "exit(" << Result << ") returned!\n";
 633         abort();
 634       }
 635     }
 636     WithColor::error(errs(), argv[0]) << "exit defined with wrong prototype!\n";
 637     abort();
 638   } else {
 639     // else == "if (RemoteMCJIT)"
 640
 641     // Remote target MCJIT doesn't (yet) support static constructors. No reason
 642     // it couldn't. This is a limitation of the LLI implementation, not the
 643     // MCJIT itself. FIXME.
 644
 645     // Lanch the remote process and get a channel to it.
 646     std::unique_ptr<FDRawChannel> C = launchRemote();
 647     if (!C) {
 648       WithColor::error(errs(), argv[0]) << "failed to launch remote JIT.\n";
 649       exit(1);
 650     }
 651
 652     // Create a remote target client running over the channel.
 653     llvm::orc::ExecutionSession ES;
 654     ES.setErrorReporter([&](Error Err) { ExitOnErr(std::move(Err)); });
 655     typedef orc::remote::OrcRemoteTargetClient MyRemote;
 656     auto R = ExitOnErr(MyRemote::Create(*C, ES));
 657
 658     // Create a remote memory manager.
 659     auto RemoteMM = ExitOnErr(R->createRemoteMemoryManager());
 660
 661     // Forward MCJIT's memory manager calls to the remote memory manager.
 662     static_cast<ForwardingMemoryManager*>(RTDyldMM)->setMemMgr(
 663       std::move(RemoteMM));
 664
 665     // Forward MCJIT's symbol resolution calls to the remote.
 666     static_cast<ForwardingMemoryManager *>(RTDyldMM)->setResolver(
 667         orc::createLambdaResolver(
 668             [](const std::string &Name) { return nullptr; },
 669             [&](const std::string &Name) {
 670               if (auto Addr = ExitOnErr(R->getSymbolAddress(Name)))
 671                 return JITSymbol(Addr, JITSymbolFlags::Exported);
 672               return JITSymbol(nullptr);
 673             }));
 674
 675     // Grab the target address of the JIT'd main function on the remote and call
 676     // it.
 677     // FIXME: argv and envp handling.
 678     JITTargetAddress Entry = EE->getFunctionAddress(EntryFn->getName().str());
 679     EE->finalizeObject();
 680     LLVM_DEBUG(dbgs() << "Executing '" << EntryFn->getName() << "' at 0x"
 681                       << format("%llx", Entry) << "\n");
 682     Result = ExitOnErr(R->callIntVoid(Entry));
 683
 684     // Like static constructors, the remote target MCJIT support doesn't handle
 685     // this yet. It could. FIXME.
 686
 687     // Delete the EE - we need to tear it down *before* we terminate the session
 688     // with the remote, otherwise it'll crash when it tries to release resources
 689     // on a remote that has already been disconnected.
 690     EE.reset();
 691
 692     // Signal the remote target that we're done JITing.
 693     ExitOnErr(R->terminateSession());
 694   }
 695
 696   return Result;
 697 }
 698
 699 static orc::IRTransformLayer::TransformFunction createDebugDumper() {
 700   switch (OrcDumpKind) {
 701   case DumpKind::NoDump:
 702     return [](orc::ThreadSafeModule TSM,
 703               const orc::MaterializationResponsibility &R) { return TSM; };
 704
 705   case DumpKind::DumpFuncsToStdOut:
 706     return [](orc::ThreadSafeModule TSM,
 707               const orc::MaterializationResponsibility &R) {
 708       printf("[ ");
 709
 710       for (const auto &F : *TSM.getModule()) {
 711         if (F.isDeclaration())
 712           continue;
 713
 714         if (F.hasName()) {
 715           std::string Name(F.getName());
 716           printf("%s ", Name.c_str());
 717         } else
 718           printf("<anon> ");
 719       }
 720
 721       printf("]\n");
 722       return TSM;
 723     };
 724
 725   case DumpKind::DumpModsToStdOut:
 726     return [](orc::ThreadSafeModule TSM,
 727               const orc::MaterializationResponsibility &R) {
 728       outs() << "----- Module Start -----\n"
 729              << *TSM.getModule() << "----- Module End -----\n";
 730
 731       return TSM;
 732     };
 733
 734   case DumpKind::DumpModsToDisk:
 735     return [](orc::ThreadSafeModule TSM,
 736               const orc::MaterializationResponsibility &R) {
 737       std::error_code EC;
 738       raw_fd_ostream Out(TSM.getModule()->getModuleIdentifier() + ".ll", EC,
 739                          sys::fs::F_Text);
 740       if (EC) {
 741         errs() << "Couldn't open " << TSM.getModule()->getModuleIdentifier()
 742                << " for dumping.\nError:" << EC.message() << "\n";
 743         exit(1);
 744       }
 745       Out << *TSM.getModule();
 746       return TSM;
 747     };
 748   }
 749   llvm_unreachable("Unknown DumpKind");
 750 }
 751
 752 static void exitOnLazyCallThroughFailure() { exit(1); }
 753
 754 int runOrcLazyJIT(const char *ProgName) {
 755   // Start setting up the JIT environment.
 756
 757   // Parse the main module.
 758   orc::ThreadSafeContext TSCtx(llvm::make_unique<LLVMContext>());
 759   SMDiagnostic Err;
 760   auto MainModule = orc::ThreadSafeModule(
 761       parseIRFile(InputFile, Err, *TSCtx.getContext()), TSCtx);
 762   if (!MainModule)
 763     reportError(Err, ProgName);
 764
 765   const auto &TT = MainModule.getModule()->getTargetTriple();
 766   orc::JITTargetMachineBuilder JTMB =
 767       TT.empty() ? ExitOnErr(orc::JITTargetMachineBuilder::detectHost())
 768                  : orc::JITTargetMachineBuilder(Triple(TT));
 769
 770   if (!MArch.empty())
 771     JTMB.getTargetTriple().setArchName(MArch);
 772
 773   JTMB.setCPU(getCPUStr())
 774       .addFeatures(getFeatureList())
 775       .setRelocationModel(RelocModel.getNumOccurrences()
 776                               ? Optional<Reloc::Model>(RelocModel)
 777                               : None)
 778       .setCodeModel(CMModel.getNumOccurrences()
 779                         ? Optional<CodeModel::Model>(CMModel)
 780                         : None);
 781
 782   DataLayout DL = ExitOnErr(JTMB.getDefaultDataLayoutForTarget());
 783
 784   auto J = ExitOnErr(orc::LLLazyJIT::Create(
 785       std::move(JTMB), DL,
 786       pointerToJITTargetAddress(exitOnLazyCallThroughFailure),
 787       LazyJITCompileThreads));
 788
 789   if (PerModuleLazy)
 790     J->setPartitionFunction(orc::CompileOnDemandLayer::compileWholeModule);
 791
 792   auto Dump = createDebugDumper();
 793
 794   J->setLazyCompileTransform([&](orc::ThreadSafeModule TSM,
 795                                  const orc::MaterializationResponsibility &R) {
 796     if (verifyModule(*TSM.getModule(), &dbgs())) {
 797       dbgs() << "Bad module: " << *TSM.getModule() << "\n";
 798       exit(1);
 799     }
 800     return Dump(std::move(TSM), R);
 801   });
 802   J->getMainJITDylib().setGenerator(
 803       ExitOnErr(orc::DynamicLibrarySearchGenerator::GetForCurrentProcess(DL)));
 804
 805   orc::MangleAndInterner Mangle(J->getExecutionSession(), DL);
 806   orc::LocalCXXRuntimeOverrides CXXRuntimeOverrides;
 807   ExitOnErr(CXXRuntimeOverrides.enable(J->getMainJITDylib(), Mangle));
 808
 809   // Add the main module.
 810   ExitOnErr(J->addLazyIRModule(std::move(MainModule)));
 811
 812   // Create JITDylibs and add any extra modules.
 813   {
 814     // Create JITDylibs, keep a map from argument index to dylib. We will use
 815     // -extra-module argument indexes to determine what dylib to use for each
 816     // -extra-module.
 817     std::map<unsigned, orc::JITDylib *> IdxToDylib;
 818     IdxToDylib[0] = &J->getMainJITDylib();
 819     for (auto JDItr = JITDylibs.begin(), JDEnd = JITDylibs.end();
 820          JDItr != JDEnd; ++JDItr) {
 821       IdxToDylib[JITDylibs.getPosition(JDItr - JITDylibs.begin())] =
 822           &J->createJITDylib(*JDItr);
 823     }
 824
 825     for (auto EMItr = ExtraModules.begin(), EMEnd = ExtraModules.end();
 826          EMItr != EMEnd; ++EMItr) {
 827       auto M = parseIRFile(*EMItr, Err, *TSCtx.getContext());
 828       if (!M)
 829         reportError(Err, ProgName);
 830
 831       auto EMIdx = ExtraModules.getPosition(EMItr - ExtraModules.begin());
 832       assert(EMIdx != 0 && "ExtraModule should have index > 0");
 833       auto JDItr = std::prev(IdxToDylib.lower_bound(EMIdx));
 834       auto &JD = *JDItr->second;
 835       ExitOnErr(
 836           J->addLazyIRModule(JD, orc::ThreadSafeModule(std::move(M), TSCtx)));
 837     }
 838   }
 839
 840   // Add the objects.
 841   for (auto &ObjPath : ExtraObjects) {
 842     auto Obj = ExitOnErr(errorOrToExpected(MemoryBuffer::getFile(ObjPath)));
 843     ExitOnErr(J->addObjectFile(std::move(Obj)));
 844   }
 845
 846   // Generate a argument string.
 847   std::vector<std::string> Args;
 848   Args.push_back(InputFile);
 849   for (auto &Arg : InputArgv)
 850     Args.push_back(Arg);
 851
 852   // Run any static constructors.
 853   ExitOnErr(J->runConstructors());
 854
 855   // Run any -thread-entry points.
 856   std::vector<std::thread> AltEntryThreads;
 857   for (auto &ThreadEntryPoint : ThreadEntryPoints) {
 858     auto EntryPointSym = ExitOnErr(J->lookup(ThreadEntryPoint));
 859     typedef void (*EntryPointPtr)();
 860     auto EntryPoint =
 861       reinterpret_cast<EntryPointPtr>(static_cast<uintptr_t>(EntryPointSym.getAddress()));
 862     AltEntryThreads.push_back(std::thread([EntryPoint]() { EntryPoint(); }));
 863   }
 864
 865   J->getExecutionSession().dump(llvm::dbgs());
 866
 867   // Run main.
 868   auto MainSym = ExitOnErr(J->lookup("main"));
 869   typedef int (*MainFnPtr)(int, const char *[]);
 870   std::vector<const char *> ArgV;
 871   for (auto &Arg : Args)
 872     ArgV.push_back(Arg.c_str());
 873   ArgV.push_back(nullptr);
 874
 875   int ArgC = ArgV.size() - 1;
 876   auto Main =
 877       reinterpret_cast<MainFnPtr>(static_cast<uintptr_t>(MainSym.getAddress()));
 878   auto Result = Main(ArgC, (const char **)ArgV.data());
 879
 880   // Wait for -entry-point threads.
 881   for (auto &AltEntryThread : AltEntryThreads)
 882     AltEntryThread.join();
 883
 884   // Run destructors.
 885   ExitOnErr(J->runDestructors());
 886   CXXRuntimeOverrides.runDestructors();
 887
 888   return Result;
 889 }
 890
 891 void disallowOrcOptions() {
 892   // Make sure nobody used an orc-lazy specific option accidentally.
 893
 894   if (LazyJITCompileThreads != 0) {
 895     errs() << "-compile-threads requires -jit-kind=orc-lazy\n";
 896     exit(1);
 897   }
 898
 899   if (!ThreadEntryPoints.empty()) {
 900     errs() << "-thread-entry requires -jit-kind=orc-lazy\n";
 901     exit(1);
 902   }
 903
 904   if (PerModuleLazy) {
 905     errs() << "-per-module-lazy requires -jit-kind=orc-lazy\n";
 906     exit(1);
 907   }
 908 }
 909
 910 std::unique_ptr<FDRawChannel> launchRemote() {
 911 #ifndef LLVM_ON_UNIX
 912   llvm_unreachable("launchRemote not supported on non-Unix platforms");
 913 #else
 914   int PipeFD[2][2];
 915   pid_t ChildPID;
 916
 917   // Create two pipes.
 918   if (pipe(PipeFD[0]) != 0 || pipe(PipeFD[1]) != 0)
 919     perror("Error creating pipe: ");
 920
 921   ChildPID = fork();
 922
 923   if (ChildPID == 0) {
 924     // In the child...
 925
 926     // Close the parent ends of the pipes
 927     close(PipeFD[0][1]);
 928     close(PipeFD[1][0]);
 929
 930
 931     // Execute the child process.
 932     std::unique_ptr<char[]> ChildPath, ChildIn, ChildOut;
 933     {
 934       ChildPath.reset(new char[ChildExecPath.size() + 1]);
 935       std::copy(ChildExecPath.begin(), ChildExecPath.end(), &ChildPath[0]);
 936       ChildPath[ChildExecPath.size()] = '\0';
 937       std::string ChildInStr = utostr(PipeFD[0][0]);
 938       ChildIn.reset(new char[ChildInStr.size() + 1]);
 939       std::copy(ChildInStr.begin(), ChildInStr.end(), &ChildIn[0]);
 940       ChildIn[ChildInStr.size()] = '\0';
 941       std::string ChildOutStr = utostr(PipeFD[1][1]);
 942       ChildOut.reset(new char[ChildOutStr.size() + 1]);
 943       std::copy(ChildOutStr.begin(), ChildOutStr.end(), &ChildOut[0]);
 944       ChildOut[ChildOutStr.size()] = '\0';
 945     }
 946
 947     char * const args[] = { &ChildPath[0], &ChildIn[0], &ChildOut[0], nullptr };
 948     int rc = execv(ChildExecPath.c_str(), args);
 949     if (rc != 0)
 950       perror("Error executing child process: ");
 951     llvm_unreachable("Error executing child process");
 952   }
 953   // else we're the parent...
 954
 955   // Close the child ends of the pipes
 956   close(PipeFD[0][0]);
 957   close(PipeFD[1][1]);
 958
 959   // Return an RPC channel connected to our end of the pipes.
 960   return llvm::make_unique<FDRawChannel>(PipeFD[1][0], PipeFD[0][1]);
 961 #endif
 962 }