예제 #1
0
//===----------------------------------------------------------------------===//
// main Driver function
//
int main(int argc, char **argv, char * const *envp) {
  sys::PrintStackTraceOnErrorSignal();
  PrettyStackTraceProgram X(argc, argv);

  LLVMContext &Context = getGlobalContext();
  atexit(do_shutdown);  // Call llvm_shutdown() on exit.

  // 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();

  // Load the bitcode...
  SMDiagnostic Err;
  Module *Mod = ParseIRFile(InputFile, Err, Context);
  if (!Mod) {
    Err.print(argv[0], errs());
    return 1;
  }

  if (EnableCacheManager) {
    if (UseMCJIT) {
      std::string CacheName("file:");
      CacheName.append(InputFile);
      Mod->setModuleIdentifier(CacheName);
    } else
      errs() << "warning: -enable-cache-manager can only be used with MCJIT.";
  }

  // If not jitting lazily, load the whole bitcode file eagerly too.
  if (NoLazyCompilation) {
    if (error_code EC = Mod->materializeAllPermanently()) {
      errs() << argv[0] << ": bitcode didn't read correctly.\n";
      errs() << "Reason: " << EC.message() << "\n";
      exit(1);
    }
  }

  if (DebugIR) {
    if (!UseMCJIT) {
      errs() << "warning: -debug-ir used without -use-mcjit. Only partial debug"
        << " information will be emitted by the non-MC JIT engine. To see full"
        << " source debug information, enable the flag '-use-mcjit'.\n";

    }
    ModulePass *DebugIRPass = createDebugIRPass();
    DebugIRPass->runOnModule(*Mod);
  }

  std::string ErrorMsg;
  EngineBuilder builder(Mod);
  builder.setMArch(MArch);
  builder.setMCPU(MCPU);
  builder.setMAttrs(MAttrs);
  builder.setRelocationModel(RelocModel);
  builder.setCodeModel(CMModel);
  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 = 0;
  if (UseMCJIT && !ForceInterpreter) {
    builder.setUseMCJIT(true);
    if (RemoteMCJIT)
      RTDyldMM = new RemoteMemoryManager();
    else
      RTDyldMM = new SectionMemoryManager();
    builder.setMCJITMemoryManager(RTDyldMM);
  } else {
    if (RemoteMCJIT) {
      errs() << "error: Remote process execution requires -use-mcjit\n";
      exit(1);
    }
    builder.setJITMemoryManager(ForceInterpreter ? 0 :
                                JITMemoryManager::CreateDefaultMemManager());
  }

  CodeGenOpt::Level OLvl = CodeGenOpt::Default;
  switch (OptLevel) {
  default:
    errs() << argv[0] << ": invalid optimization level.\n";
    return 1;
  case ' ': break;
  case '0': OLvl = CodeGenOpt::None; break;
  case '1': OLvl = CodeGenOpt::Less; break;
  case '2': OLvl = CodeGenOpt::Default; break;
  case '3': OLvl = CodeGenOpt::Aggressive; break;
  }
  builder.setOptLevel(OLvl);

  TargetOptions Options;
  Options.UseSoftFloat = GenerateSoftFloatCalls;
  if (FloatABIForCalls != FloatABI::Default)
    Options.FloatABIType = FloatABIForCalls;
  if (GenerateSoftFloatCalls)
    FloatABIForCalls = FloatABI::Soft;

  // Remote target execution doesn't handle EH or debug registration.
  if (!RemoteMCJIT) {
    Options.JITEmitDebugInfo = EmitJitDebugInfo;
    Options.JITEmitDebugInfoToDisk = EmitJitDebugInfoToDisk;
  }

  builder.setTargetOptions(Options);

  EE = builder.create();
  if (!EE) {
    if (!ErrorMsg.empty())
      errs() << argv[0] << ": error creating EE: " << ErrorMsg << "\n";
    else
      errs() << argv[0] << ": unknown error creating EE!\n";
    exit(1);
  }

  if (EnableCacheManager) {
    CacheManager = new LLIObjectCache(ObjectCacheDir);
    EE->setObjectCache(CacheManager);
  }

  // Load any additional modules specified on the command line.
  for (unsigned i = 0, e = ExtraModules.size(); i != e; ++i) {
    Module *XMod = ParseIRFile(ExtraModules[i], Err, Context);
    if (!XMod) {
      Err.print(argv[0], errs());
      return 1;
    }
    if (EnableCacheManager) {
      if (UseMCJIT) {
        std::string CacheName("file:");
        CacheName.append(ExtraModules[i]);
        XMod->setModuleIdentifier(CacheName);
      }
      // else, we already printed a warning above.
    }
    EE->addModule(XMod);
  }

  for (unsigned i = 0, e = ExtraObjects.size(); i != e; ++i) {
    ErrorOr<object::ObjectFile *> Obj =
        object::ObjectFile::createObjectFile(ExtraObjects[i]);
    if (!Obj) {
      Err.print(argv[0], errs());
      return 1;
    }
    EE->addObjectFile(Obj.get());
  }

  for (unsigned i = 0, e = ExtraArchives.size(); i != e; ++i) {
    OwningPtr<MemoryBuffer> ArBuf;
    error_code ec;
    ec = MemoryBuffer::getFileOrSTDIN(ExtraArchives[i], ArBuf);
    if (ec) {
      Err.print(argv[0], errs());
      return 1;
    }
    object::Archive *Ar = new object::Archive(ArBuf.take(), ec);
    if (ec || !Ar) {
      Err.print(argv[0], errs());
      return 1;
    }
    EE->addArchive(Ar);
  }

  // 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 (!NoLazyCompilation && RemoteMCJIT) {
    errs() << "warning: 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 = 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) {
    errs() << '\'' << EntryFunc << "\' function not found in module.\n";
    return -1;
  }

  // Reset errno to zero on entry to main.
  errno = 0;

  int Result;

  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.
    Constant *Exit = Mod->getOrInsertFunction("exit", Type::getVoidTy(Context),
                                                      Type::getInt32Ty(Context),
                                                      NULL);

    // Run static constructors.
    if (UseMCJIT && !ForceInterpreter) {
      // Give MCJIT a chance to apply relocations and set page permissions.
      EE->finalizeObject();
    }
    EE->runStaticConstructorsDestructors(false);

    if (!UseMCJIT && NoLazyCompilation) {
      for (Module::iterator I = Mod->begin(), E = Mod->end(); I != E; ++I) {
        Function *Fn = &*I;
        if (Fn != EntryFn && !Fn->isDeclaration())
          EE->getPointerToFunction(Fn);
      }
    }

    // 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)) {
      std::vector<GenericValue> Args;
      GenericValue ResultGV;
      ResultGV.IntVal = APInt(32, Result);
      Args.push_back(ResultGV);
      EE->runFunction(ExitF, Args);
      errs() << "ERROR: exit(" << Result << ") returned!\n";
      abort();
    } else {
      errs() << "ERROR: 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 implemantation, not the
    // MCJIT itself. FIXME.
    //
    RemoteMemoryManager *MM = static_cast<RemoteMemoryManager*>(RTDyldMM);
    // Everything is prepared now, so lay out our program for the target
    // address space, assign the section addresses to resolve any relocations,
    // and send it to the target.

    OwningPtr<RemoteTarget> Target;
    if (!ChildExecPath.empty()) { // Remote execution on a child process
      if (!RemoteTarget::hostSupportsExternalRemoteTarget()) {
        errs() << "Warning: host does not support external remote targets.\n"
               << "  Defaulting to simulated remote execution\n";
        Target.reset(RemoteTarget::createRemoteTarget());
      } else {
        if (!sys::fs::can_execute(ChildExecPath)) {
          errs() << "Unable to find usable child executable: '" << ChildExecPath
                 << "'\n";
          return -1;
        }
        Target.reset(RemoteTarget::createExternalRemoteTarget(ChildExecPath));
      }
    } else {
      // No child process name provided, use simulated remote execution.
      Target.reset(RemoteTarget::createRemoteTarget());
    }

    // Give the memory manager a pointer to our remote target interface object.
    MM->setRemoteTarget(Target.get());

    // Create the remote target.
    if (!Target->create()) {
      errs() << "ERROR: " << Target->getErrorMsg() << "\n";
      return EXIT_FAILURE;
    }

    // Since we're executing in a (at least simulated) remote address space,
    // we can't use the ExecutionEngine::runFunctionAsMain(). We have to
    // grab the function address directly here and tell the remote target
    // to execute the function.
    //
    // Our memory manager will map generated code into the remote address
    // space as it is loaded and copy the bits over during the finalizeMemory
    // operation.
    //
    // FIXME: argv and envp handling.
    uint64_t Entry = EE->getFunctionAddress(EntryFn->getName().str());

    DEBUG(dbgs() << "Executing '" << EntryFn->getName() << "' at 0x"
                 << format("%llx", Entry) << "\n");

    if (!Target->executeCode(Entry, Result))
      errs() << "ERROR: " << Target->getErrorMsg() << "\n";

    // Like static constructors, the remote target MCJIT support doesn't handle
    // this yet. It could. FIXME.

    // Stop the remote target
    Target->stop();
  }

  return Result;
}