//===-- driver.cpp - Clang GCC-Compatible Driver --------------------------===//

//

// 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 is the entry point to the clang driver; it is a thin wrapper

// for functionality in the Driver clang library.

//

//===----------------------------------------------------------------------===//

#include "clang/Driver/Driver.h"

#include "clang/Basic/DiagnosticOptions.h"

#include "clang/Basic/Stack.h"

#include "clang/Config/config.h"

#include "clang/Driver/Compilation.h"

#include "clang/Driver/DriverDiagnostic.h"

#include "clang/Driver/Options.h"

#include "clang/Driver/ToolChain.h"

#include "clang/Frontend/ChainedDiagnosticConsumer.h"

#include "clang/Frontend/CompilerInvocation.h"

#include "clang/Frontend/SerializedDiagnosticPrinter.h"

#include "clang/Frontend/TextDiagnosticPrinter.h"

#include "clang/Frontend/Utils.h"

#include "llvm/ADT/ArrayRef.h"

#include "llvm/ADT/SmallString.h"

#include "llvm/ADT/SmallVector.h"

#include "llvm/Option/ArgList.h"

#include "llvm/Option/OptTable.h"

#include "llvm/Option/Option.h"

#include "llvm/Support/BuryPointer.h"

#include "llvm/Support/CommandLine.h"

#include "llvm/Support/CrashRecoveryContext.h"

#include "llvm/Support/ErrorHandling.h"

#include "llvm/Support/FileSystem.h"

#include "llvm/Support/Host.h"

#include "llvm/Support/InitLLVM.h"

#include "llvm/Support/Path.h"

#include "llvm/Support/PrettyStackTrace.h"

#include "llvm/Support/Process.h"

#include "llvm/Support/Program.h"

#include "llvm/Support/Regex.h"

#include "llvm/Support/Signals.h"

#include "llvm/Support/StringSaver.h"

#include "llvm/Support/TargetSelect.h"

#include "llvm/Support/Timer.h"

#include "llvm/Support/raw_ostream.h"

#include <memory>

#include <set>

#include <system_error>

using namespace clang;

using namespace clang::driver;

using namespace llvm::opt;

std::string GetExecutablePath(const char *Argv0, bool CanonicalPrefixes) {

  if (!CanonicalPrefixes) {

    SmallString<128> ExecutablePath(Argv0);

    // Do a PATH lookup if Argv0 isn't a valid path.

    if (!llvm::sys::fs::exists(ExecutablePath))

      if (llvm::ErrorOr<std::string> P =

              llvm::sys::findProgramByName(ExecutablePath))

        ExecutablePath = *P;

    return std::string(ExecutablePath.str());

  }

  // This just needs to be some symbol in the binary; C++ doesn't

  // allow taking the address of ::main however.

  void *P = (void*) (intptr_t) GetExecutablePath;

  return llvm::sys::fs::getMainExecutable(Argv0, P);

}

static const char *GetStableCStr(std::set<std::string> &SavedStrings,

                                 StringRef S) {

  return SavedStrings.insert(std::string(S)).first->c_str();

}

/// ApplyQAOverride - Apply a list of edits to the input argument lists.

///

/// The input string is a space separate list of edits to perform,

/// they are applied in order to the input argument lists. Edits

/// should be one of the following forms:

///

///  '#': Silence information about the changes to the command line arguments.

///

///  '^': Add FOO as a new argument at the beginning of the command line.

///

///  '+': Add FOO as a new argument at the end of the command line.

///

///  's/XXX/YYY/': Substitute the regular expression XXX with YYY in the command

///  line.

///

///  'xOPTION': Removes all instances of the literal argument OPTION.

///

///  'XOPTION': Removes all instances of the literal argument OPTION,

///  and the following argument.

///

///  'Ox': Removes all flags matching 'O' or 'O[sz0-9]' and adds 'Ox'

///  at the end of the command line.

///

/// \param OS - The stream to write edit information to.

/// \param Args - The vector of command line arguments.

/// \param Edit - The override command to perform.

/// \param SavedStrings - Set to use for storing string representations.

static void ApplyOneQAOverride(raw_ostream &OS,

                               SmallVectorImpl<const char*> &Args,

                               StringRef Edit,

                               std::set<std::string> &SavedStrings) {

  // This does not need to be efficient.

  if (Edit[0] == '^') {

    const char *Str =

      GetStableCStr(SavedStrings, Edit.substr(1));

    OS << "### Adding argument " << Str << " at beginning\n";

    Args.insert(Args.begin() + 1, Str);

  } else if (Edit[0] == '+') {

    const char *Str =

      GetStableCStr(SavedStrings, Edit.substr(1));

    OS << "### Adding argument " << Str << " at end\n";

    Args.push_back(Str);

  } else 
if (4
Edit[0] == 's'4
 && 
Edit[1] == '/'0
 && 
Edit.endswith("/")0
 &&

             
Edit.slice(2, Edit.size() - 1).contains('/')0
) {

    StringRef MatchPattern = Edit.substr(2).split('/').first;

    StringRef ReplPattern = Edit.substr(2).split('/').second;

    ReplPattern = ReplPattern.slice(0, ReplPattern.size()-1);

    for (unsigned i = 1, e = Args.size(); i != e; ++i) {

      // Ignore end-of-line response file markers

      if (Args[i] == nullptr)

        continue;

      std::string Repl = llvm::Regex(MatchPattern).sub(ReplPattern, Args[i]);

      if (Repl != Args[i]) {

        OS << "### Replacing '" << Args[i] << "' with '" << Repl << "'\n";

        Args[i] = GetStableCStr(SavedStrings, Repl);

      }

    }

  } else if (Edit[0] == 'x' || 
Edit[0] == 'X'2
) {

    auto Option = Edit.substr(1);

    for (unsigned i = 1; i < Args.size();) {

      if (Option == Args[i]) {

        OS << "### Deleting argument " << Args[i] << '\n';

        Args.erase(Args.begin() + i);

        if (Edit[0] == 'X') {

          if (i < Args.size()) {

            OS << "### Deleting argument " << Args[i] << '\n';

            Args.erase(Args.begin() + i);

          } else

            OS << "### Invalid X edit, end of command line!\n";

        }

      } else

        ++i;

    }

  } else 
if (1
Edit[0] == 'O'1
) {

    for (unsigned i = 1; i < Args.size();) {

      const char *A = Args[i];

      // Ignore end-of-line response file markers

      if (A == nullptr)

        continue;

      if (A[0] == '-' && 
A[1] == 'O'8
 &&

          
(7
A[2] == '\0'7
 ||

           
(6
A[3] == '\0'6
 && 
(5
A[2] == 's'5
 || 
A[2] == 'z'4
 ||

                             
(3
'0' <= A[2]3
 && 
A[2] <= '9'3
))))) {

        OS << "### Deleting argument " << Args[i] << '\n';

        Args.erase(Args.begin() + i);

      } else

        ++i;

    }

    OS << "### Adding argument " << Edit << " at end\n";

    Args.push_back(GetStableCStr(SavedStrings, '-' + Edit.str()));

  } else {

    OS << "### Unrecognized edit: " << Edit << "\n";

  }

}

/// ApplyQAOverride - Apply a comma separate list of edits to the

/// input argument lists. See ApplyOneQAOverride.

static void ApplyQAOverride(SmallVectorImpl<const char*> &Args,

                            const char *OverrideStr,

                            std::set<std::string> &SavedStrings) {

  raw_ostream *OS = &llvm::errs();

  if (OverrideStr[0] == '#') {

    ++OverrideStr;

    OS = &llvm::nulls();

  }

  *OS << "### CCC_OVERRIDE_OPTIONS: " << OverrideStr << "\n";

  // This does not need to be efficient.

  const char *S = OverrideStr;

  while (*S) {

    const char *End = ::strchr(S, ' ');

    if (!End)

      End = S + strlen(S);

    if (End != S)

      ApplyOneQAOverride(*OS, Args, std::string(S, End), SavedStrings);

    S = End;

    if (*S != '\0')

      ++S;

  }

}

extern int cc1_main(ArrayRef<const char *> Argv, const char *Argv0,

                    void *MainAddr);

extern int cc1as_main(ArrayRef<const char *> Argv, const char *Argv0,

                      void *MainAddr);

extern int cc1gen_reproducer_main(ArrayRef<const char *> Argv,

                                  const char *Argv0, void *MainAddr);

static void insertTargetAndModeArgs(const ParsedClangName &NameParts,

                                    SmallVectorImpl<const char *> &ArgVector,

                                    std::set<std::string> &SavedStrings) {

  // Put target and mode arguments at the start of argument list so that

  // arguments specified in command line could override them. Avoid putting

  // them at index 0, as an option like '-cc1' must remain the first.

  int InsertionPoint = 0;

  if (ArgVector.size() > 0)

    ++InsertionPoint;

  if (NameParts.DriverMode) {

    // Add the mode flag to the arguments.

    ArgVector.insert(ArgVector.begin() + InsertionPoint,

                     GetStableCStr(SavedStrings, NameParts.DriverMode));

  }

  if (NameParts.TargetIsValid) {

    const char *arr[] = {"-target", GetStableCStr(SavedStrings,

                                                  NameParts.TargetPrefix)};

    ArgVector.insert(ArgVector.begin() + InsertionPoint,

                     std::begin(arr), std::end(arr));

  }

}

static void getCLEnvVarOptions(std::string &EnvValue, llvm::StringSaver &Saver,

                               SmallVectorImpl<const char *> &Opts) {

  llvm::cl::TokenizeWindowsCommandLine(EnvValue, Saver, Opts);

  // The first instance of '#' should be replaced with '=' in each option.

  for (const char *Opt : Opts)

    if (char *NumberSignPtr = const_cast<char *>(::strchr(Opt, '#')))

      *NumberSignPtr = '=';

}

static void SetBackdoorDriverOutputsFromEnvVars(Driver &TheDriver) {

  auto CheckEnvVar = [](const char *EnvOptSet, const char *EnvOptFile,

                        std::string &OptFile) {

    bool OptSet = !!::getenv(EnvOptSet);

    if (OptSet) {

      if (const char *Var = ::getenv(EnvOptFile))

        OptFile = Var;

    }

    return OptSet;

  };

  TheDriver.CCPrintOptions =

      CheckEnvVar("CC_PRINT_OPTIONS", "CC_PRINT_OPTIONS_FILE",

                  TheDriver.CCPrintOptionsFilename);

  TheDriver.CCPrintHeaders =

      CheckEnvVar("CC_PRINT_HEADERS", "CC_PRINT_HEADERS_FILE",

                  TheDriver.CCPrintHeadersFilename);

  TheDriver.CCLogDiagnostics =

      CheckEnvVar("CC_LOG_DIAGNOSTICS", "CC_LOG_DIAGNOSTICS_FILE",

                  TheDriver.CCLogDiagnosticsFilename);

  TheDriver.CCPrintProcessStats =

      CheckEnvVar("CC_PRINT_PROC_STAT", "CC_PRINT_PROC_STAT_FILE",

                  TheDriver.CCPrintStatReportFilename);

}

static void FixupDiagPrefixExeName(TextDiagnosticPrinter *DiagClient,

                                   const std::string &Path) {

  // If the clang binary happens to be named cl.exe for compatibility reasons,

  // use clang-cl.exe as the prefix to avoid confusion between clang and MSVC.

  StringRef ExeBasename(llvm::sys::path::stem(Path));

  if (ExeBasename.equals_insensitive("cl"))

    ExeBasename = "clang-cl";

  DiagClient->setPrefix(std::string(ExeBasename));

}

static void SetInstallDir(SmallVectorImpl<const char *> &argv,

                          Driver &TheDriver, bool CanonicalPrefixes) {

  // Attempt to find the original path used to invoke the driver, to determine

  // the installed path. We do this manually, because we want to support that

  // path being a symlink.

  SmallString<128> InstalledPath(argv[0]);

  // Do a PATH lookup, if there are no directory components.

  if (llvm::sys::path::filename(InstalledPath) == InstalledPath)

    if (llvm::ErrorOr<std::string> Tmp = llvm::sys::findProgramByName(

            llvm::sys::path::filename(InstalledPath.str())))

      InstalledPath = *Tmp;

  // FIXME: We don't actually canonicalize this, we just make it absolute.

  if (CanonicalPrefixes)

    llvm::sys::fs::make_absolute(InstalledPath);

  StringRef InstalledPathParent(llvm::sys::path::parent_path(InstalledPath));

  if (llvm::sys::fs::exists(InstalledPathParent))

    TheDriver.setInstalledDir(InstalledPathParent);

}

static int ExecuteCC1Tool(SmallVectorImpl<const char *> &ArgV) {

  // If we call the cc1 tool from the clangDriver library (through

  // Driver::CC1Main), we need to clean up the options usage count. The options

  // are currently global, and they might have been used previously by the

  // driver.

  llvm::cl::ResetAllOptionOccurrences();

  llvm::BumpPtrAllocator A;

  llvm::StringSaver Saver(A);

  llvm::cl::ExpandResponseFiles(Saver, &llvm::cl::TokenizeGNUCommandLine, ArgV,

                                /*MarkEOLs=*/false);

  StringRef Tool = ArgV[1];

  void *GetExecutablePathVP = (void *)(intptr_t)GetExecutablePath;

  if (Tool == "-cc1")

    return cc1_main(makeArrayRef(ArgV).slice(1), ArgV[0], GetExecutablePathVP);

  if (Tool == "-cc1as")

    return cc1as_main(makeArrayRef(ArgV).slice(2), ArgV[0],

                      GetExecutablePathVP);

  if (Tool == "-cc1gen-reproducer")

    return cc1gen_reproducer_main(makeArrayRef(ArgV).slice(2), ArgV[0],

                                  GetExecutablePathVP);

  // Reject unknown tools.

  llvm::errs() << "error: unknown integrated tool '" << Tool << "'. "

               << "Valid tools include '-cc1' and '-cc1as'.\n";

  return 1;

}

int clang_main(int Argc, char **Argv) {

  noteBottomOfStack();

  llvm::InitLLVM X(Argc, Argv);

  llvm::setBugReportMsg("PLEASE submit a bug report to " BUG_REPORT_URL

                        " and include the crash backtrace, preprocessed "

                        "source, and associated run script.\n");

  SmallVector<const char *, 256> Args(Argv, Argv + Argc);

  if (llvm::sys::Process::FixupStandardFileDescriptors())

    return 1;

  llvm::InitializeAllTargets();

  llvm::BumpPtrAllocator A;

  llvm::StringSaver Saver(A);

  // Parse response files using the GNU syntax, unless we're in CL mode. There

  // are two ways to put clang in CL compatibility mode: Args[0] is either

  // clang-cl or cl, or --driver-mode=cl is on the command line. The normal

  // command line parsing can't happen until after response file parsing, so we

  // have to manually search for a --driver-mode=cl argument the hard way.

  // Finally, our -cc1 tools don't care which tokenization mode we use because

  // response files written by clang will tokenize the same way in either mode.

  bool ClangCLMode =

      IsClangCL(getDriverMode(Args[0], llvm::makeArrayRef(Args).slice(1)));

  enum { Default, POSIX, Windows } RSPQuoting = Default;

  for (const char *F : Args) {

    if (strcmp(F, "--rsp-quoting=posix") == 0)

      RSPQuoting = POSIX;

    else if (strcmp(F, "--rsp-quoting=windows") == 0)

      RSPQuoting = Windows;

  }

  // Determines whether we want nullptr markers in Args to indicate response

  // files end-of-lines. We only use this for the /LINK driver argument with

  // clang-cl.exe on Windows.

  bool MarkEOLs = ClangCLMode;

  llvm::cl::TokenizerCallback Tokenizer;

  if (RSPQuoting == Windows || 
(55.6k
RSPQuoting == Default55.6k
 && 
ClangCLMode55.6k
))

    Tokenizer = &llvm::cl::TokenizeWindowsCommandLine;

  else

    Tokenizer = &llvm::cl::TokenizeGNUCommandLine;

  if (MarkEOLs && 
Args.size() > 1593
 && 
StringRef(Args[1]).startswith("-cc1")593
)

    MarkEOLs = false;

  llvm::cl::ExpandResponseFiles(Saver, Tokenizer, Args, MarkEOLs);

  // Handle -cc1 integrated tools, even if -cc1 was expanded from a response

  // file.

  auto FirstArg = llvm::find_if(llvm::drop_begin(Args),

                                [](const char *A) { return A != nullptr; });

  if (FirstArg != Args.end() && StringRef(*FirstArg).startswith("-cc1")) {

    // If -cc1 came from a response file, remove the EOL sentinels.

    if (MarkEOLs) {

      auto newEnd = std::remove(Args.begin(), Args.end(), nullptr);

      Args.resize(newEnd - Args.begin());

    }

    return ExecuteCC1Tool(Args);

  }

  // Handle options that need handling before the real command line parsing in

  // Driver::BuildCompilation()

  bool CanonicalPrefixes = true;

  for (int i = 1, size = Args.size(); i < size; 
++i526k
) {

    // Skip end-of-line response file markers

    if (Args[i] == nullptr)

      continue;

    if (StringRef(Args[i]) == "-canonical-prefixes")

      CanonicalPrefixes = true;

    else if (StringRef(Args[i]) == "-no-canonical-prefixes")

      CanonicalPrefixes = false;

  }

  // Handle CL and _CL_ which permits additional command line options to be

  // prepended or appended.

  if (ClangCLMode) {

    // Arguments in "CL" are prepended.

    llvm::Optional<std::string> OptCL = llvm::sys::Process::GetEnv("CL");

    if (OptCL) {

      SmallVector<const char *, 8> PrependedOpts;

      getCLEnvVarOptions(OptCL.value(), Saver, PrependedOpts);

      // Insert right after the program name to prepend to the argument list.

      Args.insert(Args.begin() + 1, PrependedOpts.begin(), PrependedOpts.end());

    }

    // Arguments in "_CL_" are appended.

    llvm::Optional<std::string> Opt_CL_ = llvm::sys::Process::GetEnv("_CL_");

    if (Opt_CL_) {

      SmallVector<const char *, 8> AppendedOpts;

      getCLEnvVarOptions(Opt_CL_.value(), Saver, AppendedOpts);

      // Insert at the end of the argument list to append.

      Args.append(AppendedOpts.begin(), AppendedOpts.end());

    }

  }

  std::set<std::string> SavedStrings;

  // Handle CCC_OVERRIDE_OPTIONS, used for editing a command line behind the

  // scenes.

  if (const char *OverrideStr = ::getenv("CCC_OVERRIDE_OPTIONS")) {

    // FIXME: Driver shouldn't take extra initial argument.

    ApplyQAOverride(Args, OverrideStr, SavedStrings);

  }

  std::string Path = GetExecutablePath(Args[0], CanonicalPrefixes);

  // Whether the cc1 tool should be called inside the current process, or if we

  // should spawn a new clang subprocess (old behavior).

  // Not having an additional process saves some execution time of Windows,

  // and makes debugging and profiling easier.

  bool UseNewCC1Process = CLANG_SPAWN_CC1;

  for (const char *Arg : Args)

    UseNewCC1Process = llvm::StringSwitch<bool>(Arg)

                           .Case("-fno-integrated-cc1", true)

                           .Case("-fintegrated-cc1", false)

                           .Default(UseNewCC1Process);

  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts =

      CreateAndPopulateDiagOpts(Args);

  TextDiagnosticPrinter *DiagClient

    = new TextDiagnosticPrinter(llvm::errs(), &*DiagOpts);

  FixupDiagPrefixExeName(DiagClient, Path);

  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());

  DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagClient);

  if (!DiagOpts->DiagnosticSerializationFile.empty()) {

    auto SerializedConsumer =

        clang::serialized_diags::create(DiagOpts->DiagnosticSerializationFile,

                                        &*DiagOpts, /*MergeChildRecords=*/true);

    Diags.setClient(new ChainedDiagnosticConsumer(

        Diags.takeClient(), std::move(SerializedConsumer)));

  }

  ProcessWarningOptions(Diags, *DiagOpts, /*ReportDiags=*/false);

  Driver TheDriver(Path, llvm::sys::getDefaultTargetTriple(), Diags);

  SetInstallDir(Args, TheDriver, CanonicalPrefixes);

  auto TargetAndMode = ToolChain::getTargetAndModeFromProgramName(Args[0]);

  TheDriver.setTargetAndMode(TargetAndMode);

  insertTargetAndModeArgs(TargetAndMode, Args, SavedStrings);

  SetBackdoorDriverOutputsFromEnvVars(TheDriver);

  if (!UseNewCC1Process) {

    TheDriver.CC1Main = &ExecuteCC1Tool;

    // Ensure the CC1Command actually catches cc1 crashes

    llvm::CrashRecoveryContext::Enable();

  }

  std::unique_ptr<Compilation> C(TheDriver.BuildCompilation(Args));

  Driver::ReproLevel ReproLevel = Driver::ReproLevel::OnCrash;

  if (Arg *A = C->getArgs().getLastArg(options::OPT_gen_reproducer_eq)) {

    auto Level = llvm::StringSwitch<Optional<Driver::ReproLevel>>(A->getValue())

                     .Case("off", Driver::ReproLevel::Off)

                     .Case("crash", Driver::ReproLevel::OnCrash)

                     .Case("error", Driver::ReproLevel::OnError)

                     .Case("always", Driver::ReproLevel::Always)

                     .Default(None);

    if (!Level) {

      llvm::errs() << "Unknown value for " << A->getSpelling() << ": '"

                   << A->getValue() << "'\n";

      return 1;

    }

    ReproLevel = *Level;

  }

  if (!!::getenv("FORCE_CLANG_DIAGNOSTICS_CRASH"))

    ReproLevel = Driver::ReproLevel::Always;

  int Res = 1;

  bool IsCrash = false;

  Driver::CommandStatus CommandStatus = Driver::CommandStatus::Ok;

  // Pretend the first command failed if ReproStatus is Always.

  const Command *FailingCommand = nullptr;

  if (!C->getJobs().empty())

    FailingCommand = &*C->getJobs().begin();

  if (C && !C->containsError()) {

    SmallVector<std::pair<int, const Command *>, 4> FailingCommands;

    Res = TheDriver.ExecuteCompilation(*C, FailingCommands);

    for (const auto &P : FailingCommands) {

      int CommandRes = P.first;

      FailingCommand = P.second;

      if (!Res)

        Res = CommandRes;

      // If result status is < 0, then the driver command signalled an error.

      // If result status is 70, then the driver command reported a fatal error.

      // On Windows, abort will return an exit code of 3.  In these cases,

      // generate additional diagnostic information if possible.

      IsCrash = CommandRes < 0 || CommandRes == 70;

#ifdef _WIN32

      IsCrash |= CommandRes == 3;

#endif

#if LLVM_ON_UNIX

      // When running in integrated-cc1 mode, the CrashRecoveryContext returns

      // the same codes as if the program crashed. See section "Exit Status for

      // Commands":

      // https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xcu_chap02.html

      IsCrash |= CommandRes > 128;

#endif

      CommandStatus =

          IsCrash ? 
Driver::CommandStatus::Crash21
 : 
Driver::CommandStatus::Error261
;

      if (IsCrash)

        break;

    }

  }

  // Print the bug report message that would be printed if we did actually

  // crash, but only if we're crashing due to FORCE_CLANG_DIAGNOSTICS_CRASH.

  if (::getenv("FORCE_CLANG_DIAGNOSTICS_CRASH"))

    llvm::dbgs() << llvm::getBugReportMsg();

  if (FailingCommand != nullptr &&

    TheDriver.maybeGenerateCompilationDiagnostics(CommandStatus, ReproLevel,

                                                  *C, *FailingCommand))

    Res = 1;

  Diags.getClient()->finish();

  if (!UseNewCC1Process && 
IsCrash19.8k
) {

    // When crashing in -fintegrated-cc1 mode, bury the timer pointers, because

    // the internal linked list might point to already released stack frames.

    llvm::BuryPointer(llvm::TimerGroup::aquireDefaultGroup());

  } else {

    // If any timers were active but haven't been destroyed yet, print their

    // results now.  This happens in -disable-free mode.

    llvm::TimerGroup::printAll(llvm::errs());

    llvm::TimerGroup::clearAll();

  }

#ifdef _WIN32

  // Exit status should not be negative on Win32, unless abnormal termination.

  // Once abnormal termination was caught, negative status should not be

  // propagated.

  if (Res < 0)

    Res = 1;

#endif

  // If we have multiple failing commands, we return the result of the first

  // failing command.

  return Res;

}