//===- Job.cpp - Command to Execute ---------------------------------------===//

//

// 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

//

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

#include "clang/Driver/Job.h"

#include "clang/Basic/LLVM.h"

#include "clang/Driver/Driver.h"

#include "clang/Driver/DriverDiagnostic.h"

#include "clang/Driver/InputInfo.h"

#include "clang/Driver/Tool.h"

#include "clang/Driver/ToolChain.h"

#include "llvm/ADT/ArrayRef.h"

#include "llvm/ADT/SmallString.h"

#include "llvm/ADT/SmallVector.h"

#include "llvm/ADT/StringExtras.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/ADT/StringSet.h"

#include "llvm/ADT/StringSwitch.h"

#include "llvm/Support/CrashRecoveryContext.h"

#include "llvm/Support/FileSystem.h"

#include "llvm/Support/Path.h"

#include "llvm/Support/PrettyStackTrace.h"

#include "llvm/Support/Program.h"

#include "llvm/Support/raw_ostream.h"

#include <algorithm>

#include <cassert>

#include <cstddef>

#include <string>

#include <system_error>

#include <utility>

using namespace clang;

using namespace driver;

Command::Command(const Action &Source, const Tool &Creator,

                 ResponseFileSupport ResponseSupport, const char *Executable,

                 const llvm::opt::ArgStringList &Arguments,

                 ArrayRef<InputInfo> Inputs, ArrayRef<InputInfo> Outputs,

                 const char *PrependArg)

    : Source(Source), Creator(Creator), ResponseSupport(ResponseSupport),

      Executable(Executable), PrependArg(PrependArg), Arguments(Arguments) {

  for (const auto &II : Inputs)

    if (II.isFilename())

      InputInfoList.push_back(II);

  for (const auto &II : Outputs)

    if (II.isFilename())

      OutputFilenames.push_back(II.getFilename());

}

/// Check if the compiler flag in question should be skipped when

/// emitting a reproducer. Also track how many arguments it has and if the

/// option is some kind of include path.

static bool skipArgs(const char *Flag, bool HaveCrashVFS, int &SkipNum,

                     bool &IsInclude) {

  SkipNum = 2;

  // These flags are all of the form -Flag <Arg> and are treated as two

  // arguments.  Therefore, we need to skip the flag and the next argument.

  bool ShouldSkip = llvm::StringSwitch<bool>(Flag)

    .Cases("-MF", "-MT", "-MQ", "-serialize-diagnostic-file", true)

    .Cases("-o", "-dependency-file", true)

    .Cases("-fdebug-compilation-dir", "-diagnostic-log-file", true)

    .Cases("-dwarf-debug-flags", "-ivfsoverlay", true)

    .Default(false);

  if (ShouldSkip)

    return true;

  // Some include flags shouldn't be skipped if we have a crash VFS

  IsInclude = llvm::StringSwitch<bool>(Flag)

    .Cases("-include", "-header-include-file", true)

    .Cases("-idirafter", "-internal-isystem", "-iwithprefix", true)

    .Cases("-internal-externc-isystem", "-iprefix", true)

    .Cases("-iwithprefixbefore", "-isystem", "-iquote", true)

    .Cases("-isysroot", "-I", "-F", "-resource-dir", true)

    .Cases("-iframework", "-include-pch", true)

    .Default(false);

  if (IsInclude)

    return !HaveCrashVFS;

  // The remaining flags are treated as a single argument.

  // These flags are all of the form -Flag and have no second argument.

  ShouldSkip = llvm::StringSwitch<bool>(Flag)

    .Cases("-M", "-MM", "-MG", "-MP", "-MD", true)

    .Case("-MMD", true)

    .Default(false);

  // Match found.

  SkipNum = 1;

  if (ShouldSkip)

    return true;

  // These flags are treated as a single argument (e.g., -F<Dir>).

  StringRef FlagRef(Flag);

  IsInclude = FlagRef.starts_with("-F") || FlagRef.starts_with("-I");

  if (IsInclude)

    return !HaveCrashVFS;

  if (FlagRef.starts_with("-fmodules-cache-path="))

    return true;

  SkipNum = 0;

  return false;

}

void Command::writeResponseFile(raw_ostream &OS) const {

  // In a file list, we only write the set of inputs to the response file

  if (ResponseSupport.ResponseKind == ResponseFileSupport::RF_FileList) {

    for (const auto *Arg : InputFileList) {

      OS << Arg << '\n';

    }

    return;

  }

  // In regular response files, we send all arguments to the response file.

  // Wrapping all arguments in double quotes ensures that both Unix tools and

  // Windows tools understand the response file.

  for (const auto *Arg : Arguments) {

    OS << '"';

    for (; *Arg != '\0'; Arg++) {

      if (*Arg == '\"' || *Arg == '\\') {

        OS << '\\';

      }

      OS << *Arg;

    }

    OS << "\" ";

  }

}

void Command::buildArgvForResponseFile(

    llvm::SmallVectorImpl<const char *> &Out) const {

  // When not a file list, all arguments are sent to the response file.

  // This leaves us to set the argv to a single parameter, requesting the tool

  // to read the response file.

  if (ResponseSupport.ResponseKind != ResponseFileSupport::RF_FileList) {

    Out.push_back(Executable);

    Out.push_back(ResponseFileFlag.c_str());

    return;

  }

  llvm::StringSet<> Inputs;

  for (const auto *InputName : InputFileList)

    Inputs.insert(InputName);

  Out.push_back(Executable);

  if (PrependArg)

    Out.push_back(PrependArg);

  // In a file list, build args vector ignoring parameters that will go in the

  // response file (elements of the InputFileList vector)

  bool FirstInput = true;

  for (const auto *Arg : Arguments) {

    if (Inputs.count(Arg) == 0) {

      Out.push_back(Arg);

    } else if (FirstInput) {

      FirstInput = false;

      Out.push_back(ResponseSupport.ResponseFlag);

      Out.push_back(ResponseFile);

    }

  }

}

/// Rewrite relative include-like flag paths to absolute ones.

static void

rewriteIncludes(const llvm::ArrayRef<const char *> &Args, size_t Idx,

                size_t NumArgs,

                llvm::SmallVectorImpl<llvm::SmallString<128>> &IncFlags) {

  using namespace llvm;

  using namespace sys;

  auto getAbsPath = [](StringRef InInc, SmallVectorImpl<char> &OutInc) -> bool {

    if (path::is_absolute(InInc)) // Nothing to do here...

      return false;

    std::error_code EC = fs::current_path(OutInc);

    if (EC)

      return false;

    path::append(OutInc, InInc);

    return true;

  };

  SmallString<128> NewInc;

  if (NumArgs == 1) {

    StringRef FlagRef(Args[Idx + NumArgs - 1]);

    assert((FlagRef.starts_with("-F") || FlagRef.starts_with("-I")) &&

           "Expecting -I or -F");

    StringRef Inc = FlagRef.slice(2, StringRef::npos);

    if (getAbsPath(Inc, NewInc)) {

      SmallString<128> NewArg(FlagRef.slice(0, 2));

      NewArg += NewInc;

      IncFlags.push_back(std::move(NewArg));

    }

    return;

  }

  assert(NumArgs == 2 && "Not expecting more than two arguments");

  StringRef Inc(Args[Idx + NumArgs - 1]);

  if (!getAbsPath(Inc, NewInc))

    return;

  IncFlags.push_back(SmallString<128>(Args[Idx]));

  IncFlags.push_back(std::move(NewInc));

}

void Command::Print(raw_ostream &OS, const char *Terminator, bool Quote,

                    CrashReportInfo *CrashInfo) const {

  // Always quote the exe.

  OS << ' ';

  llvm::sys::printArg(OS, Executable, /*Quote=*/true);

  ArrayRef<const char *> Args = Arguments;

  SmallVector<const char *, 128> ArgsRespFile;

  if (ResponseFile != nullptr) {

    buildArgvForResponseFile(ArgsRespFile);

    Args = ArrayRef<const char *>(ArgsRespFile).slice(1); // no executable name

  } else if (PrependArg) {

    OS << ' ';

    llvm::sys::printArg(OS, PrependArg, /*Quote=*/true);

  }

  bool HaveCrashVFS = CrashInfo && !CrashInfo->VFSPath.empty();

  for (size_t i = 0, e = Args.size(); i < e; ++i) {

    const char *const Arg = Args[i];

    if (CrashInfo) {

      int NumArgs = 0;

      bool IsInclude = false;

      if (skipArgs(Arg, HaveCrashVFS, NumArgs, IsInclude)) {

        i += NumArgs - 1;

        continue;

      }

      // Relative includes need to be expanded to absolute paths.

      if (HaveCrashVFS && IsInclude) {

        SmallVector<SmallString<128>, 2> NewIncFlags;

        rewriteIncludes(Args, i, NumArgs, NewIncFlags);

        if (!NewIncFlags.empty()) {

          for (auto &F : NewIncFlags) {

            OS << ' ';

            llvm::sys::printArg(OS, F.c_str(), Quote);

          }

          i += NumArgs - 1;

          continue;

        }

      }

      auto Found = llvm::find_if(InputInfoList, [&Arg](const InputInfo &II) {

        return II.getFilename() == Arg;

      });

      if (Found != InputInfoList.end() &&

          (i == 0 || StringRef(Args[i - 1]) != "-main-file-name")) {

        // Replace the input file name with the crashinfo's file name.

        OS << ' ';

        StringRef ShortName = llvm::sys::path::filename(CrashInfo->Filename);

        llvm::sys::printArg(OS, ShortName.str(), Quote);

        continue;

      }

    }

    OS << ' ';

    llvm::sys::printArg(OS, Arg, Quote);

  }

  if (CrashInfo && HaveCrashVFS) {

    OS << ' ';

    llvm::sys::printArg(OS, "-ivfsoverlay", Quote);

    OS << ' ';

    llvm::sys::printArg(OS, CrashInfo->VFSPath.str(), Quote);

    // The leftover modules from the crash are stored in

    //  <name>.cache/vfs/modules

    // Leave it untouched for pcm inspection and provide a clean/empty dir

    // path to contain the future generated module cache:

    //  <name>.cache/vfs/repro-modules

    SmallString<128> RelModCacheDir = llvm::sys::path::parent_path(

        llvm::sys::path::parent_path(CrashInfo->VFSPath));

    llvm::sys::path::append(RelModCacheDir, "repro-modules");

    std::string ModCachePath = "-fmodules-cache-path=";

    ModCachePath.append(RelModCacheDir.c_str());

    OS << ' ';

    llvm::sys::printArg(OS, ModCachePath, Quote);

  }

  if (ResponseFile != nullptr) {

    OS << "\n Arguments passed via response file:\n";

    writeResponseFile(OS);

    // Avoiding duplicated newline terminator, since FileLists are

    // newline-separated.

    if (ResponseSupport.ResponseKind != ResponseFileSupport::RF_FileList)

      OS << "\n";

    OS << " (end of response file)";

  }

  OS << Terminator;

}

void Command::setResponseFile(const char *FileName) {

  ResponseFile = FileName;

  ResponseFileFlag = ResponseSupport.ResponseFlag;

  ResponseFileFlag += FileName;

}

void Command::setEnvironment(llvm::ArrayRef<const char *> NewEnvironment) {

  Environment.reserve(NewEnvironment.size() + 1);

  Environment.assign(NewEnvironment.begin(), NewEnvironment.end());

  Environment.push_back(nullptr);

}

void Command::setRedirectFiles(

    const std::vector<std::optional<std::string>> &Redirects) {

  RedirectFiles = Redirects;

}

void Command::PrintFileNames() const {

  if (PrintInputFilenames) {

    for (const auto &Arg : InputInfoList)

      llvm::outs() << llvm::sys::path::filename(Arg.getFilename()) << "\n";

    llvm::outs().flush();

  }

}

int Command::Execute(ArrayRef<std::optional<StringRef>> Redirects,

                     std::string *ErrMsg, bool *ExecutionFailed) const {

  PrintFileNames();

  SmallVector<const char *, 128> Argv;

  if (ResponseFile == nullptr) {

    Argv.push_back(Executable);

    if (PrependArg)

      Argv.push_back(PrependArg);

    Argv.append(Arguments.begin(), Arguments.end());

    Argv.push_back(nullptr);

  } else {

    // If the command is too large, we need to put arguments in a response file.

    std::string RespContents;

    llvm::raw_string_ostream SS(RespContents);

    // Write file contents and build the Argv vector

    writeResponseFile(SS);

    buildArgvForResponseFile(Argv);

    Argv.push_back(nullptr);

    SS.flush();

    // Save the response file in the appropriate encoding

    if (std::error_code EC = writeFileWithEncoding(

            ResponseFile, RespContents, ResponseSupport.ResponseEncoding)) {

      if (ErrMsg)

        *ErrMsg = EC.message();

      if (ExecutionFailed)

        *ExecutionFailed = true;

      // Return -1 by convention (see llvm/include/llvm/Support/Program.h) to

      // indicate the requested executable cannot be started.

      return -1;

    }

  }

  std::optional<ArrayRef<StringRef>> Env;

  std::vector<StringRef> ArgvVectorStorage;

  if (!Environment.empty()) {

    assert(Environment.back() == nullptr &&

           "Environment vector should be null-terminated by now");

    ArgvVectorStorage = llvm::toStringRefArray(Environment.data());

    Env = ArrayRef(ArgvVectorStorage);

  }

  auto Args = llvm::toStringRefArray(Argv.data());

  // Use Job-specific redirect files if they are present.

  if (!RedirectFiles.empty()) {

    std::vector<std::optional<StringRef>> RedirectFilesOptional;

    for (const auto &Ele : RedirectFiles)

      if (Ele)

        RedirectFilesOptional.push_back(std::optional<StringRef>(*Ele));

      else

        RedirectFilesOptional.push_back(std::nullopt);

    return llvm::sys::ExecuteAndWait(Executable, Args, Env,

                                     ArrayRef(RedirectFilesOptional),

                                     /*secondsToWait=*/0, /*memoryLimit=*/0,

                                     ErrMsg, ExecutionFailed, &ProcStat);

  }

  return llvm::sys::ExecuteAndWait(Executable, Args, Env, Redirects,

                                   /*secondsToWait*/ 0, /*memoryLimit*/ 0,

                                   ErrMsg, ExecutionFailed, &ProcStat);

}

CC1Command::CC1Command(const Action &Source, const Tool &Creator,

                       ResponseFileSupport ResponseSupport,

                       const char *Executable,

                       const llvm::opt::ArgStringList &Arguments,

                       ArrayRef<InputInfo> Inputs, ArrayRef<InputInfo> Outputs,

                       const char *PrependArg)

    : Command(Source, Creator, ResponseSupport, Executable, Arguments, Inputs,

              Outputs, PrependArg) {

  InProcess = true;

}

void CC1Command::Print(raw_ostream &OS, const char *Terminator, bool Quote,

                       CrashReportInfo *CrashInfo) const {

  if (InProcess)

    OS << " (in-process)\n";

  Command::Print(OS, Terminator, Quote, CrashInfo);

}

int CC1Command::Execute(ArrayRef<std::optional<StringRef>> Redirects,

                        std::string *ErrMsg, bool *ExecutionFailed) const {

  // FIXME: Currently, if there're more than one job, we disable

  // -fintegrate-cc1. If we're no longer a integrated-cc1 job, fallback to

  // out-of-process execution. See discussion in https://reviews.llvm.org/D74447

  if (!InProcess)

    return Command::Execute(Redirects, ErrMsg, ExecutionFailed);

  PrintFileNames();

  SmallVector<const char *, 128> Argv;

  Argv.push_back(getExecutable());

  Argv.append(getArguments().begin(), getArguments().end());

  Argv.push_back(nullptr);

  Argv.pop_back(); // The terminating null element shall not be part of the

                   // slice (main() behavior).

  // This flag simply indicates that the program couldn't start, which isn't

  // applicable here.

  if (ExecutionFailed)

    *ExecutionFailed = false;

  llvm::CrashRecoveryContext CRC;

  CRC.DumpStackAndCleanupOnFailure = true;

  const void *PrettyState = llvm::SavePrettyStackState();

  const Driver &D = getCreator().getToolChain().getDriver();

  int R = 0;

  // Enter ExecuteCC1Tool() instead of starting up a new process

  if (!CRC.RunSafely([&]() { R = D.CC1Main(Argv); })) {

    llvm::RestorePrettyStackState(PrettyState);

    return CRC.RetCode;

  }

  return R;

}

void CC1Command::setEnvironment(llvm::ArrayRef<const char *> NewEnvironment) {

  // We don't support set a new environment when calling into ExecuteCC1Tool()

  llvm_unreachable(

      "The CC1Command doesn't support changing the environment vars!");

}

void JobList::Print(raw_ostream &OS, const char *Terminator, bool Quote,

                    CrashReportInfo *CrashInfo) const {

  for (const auto &Job : *this)

    Job.Print(OS, Terminator, Quote, CrashInfo);

}

void JobList::clear() { Jobs.clear(); }