//===-- ProcessLaunchInfo.cpp ---------------------------------------------===//
//
// 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 <climits>

#include "lldb/Host/Config.h"
#include "lldb/Host/FileAction.h"
#include "lldb/Host/FileSystem.h"
#include "lldb/Host/HostInfo.h"
#include "lldb/Host/ProcessLaunchInfo.h"
#include "lldb/Utility/LLDBLog.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/StreamString.h"

#include "llvm/Support/ConvertUTF.h"
#include "llvm/Support/FileSystem.h"

#if !defined(_WIN32)
#include <climits>
#endif

using namespace lldb;
using namespace lldb_private;

// ProcessLaunchInfo member functions

ProcessLaunchInfo::ProcessLaunchInfo()
    : ProcessInfo(), m_working_dir(), m_plugin_name(), m_flags(0),
      m_file_actions(), m_pty(new PseudoTerminal), m_monitor_callback(nullptr) {
}

ProcessLaunchInfo::ProcessLaunchInfo(const FileSpec &stdin_file_spec,
                                     const FileSpec &stdout_file_spec,
                                     const FileSpec &stderr_file_spec,
                                     const FileSpec &working_directory,
                                     uint32_t launch_flags)
    : ProcessInfo(), m_working_dir(), m_plugin_name(), m_flags(launch_flags),
      m_file_actions(), m_pty(new PseudoTerminal) {
  if (stdin_file_spec) {
    FileAction file_action;
    const bool read = true;
    const bool write = false;
    if (file_action.Open(STDIN_FILENO, stdin_file_spec, read, write))
      AppendFileAction(file_action);
  }
  if (stdout_file_spec) {
    FileAction file_action;
    const bool read = false;
    const bool write = true;
    if (file_action.Open(STDOUT_FILENO, stdout_file_spec, read, write))
      AppendFileAction(file_action);
  }
  if (stderr_file_spec) {
    FileAction file_action;
    const bool read = false;
    const bool write = true;
    if (file_action.Open(STDERR_FILENO, stderr_file_spec, read, write))
      AppendFileAction(file_action);
  }
  if (working_directory)
    SetWorkingDirectory(working_directory);
}

bool ProcessLaunchInfo::AppendCloseFileAction(int fd) {
  FileAction file_action;
  if (file_action.Close(fd)) {
    AppendFileAction(file_action);
    return true;
  }
  return false;
}

bool ProcessLaunchInfo::AppendDuplicateFileAction(int fd, int dup_fd) {
  FileAction file_action;
  if (file_action.Duplicate(fd, dup_fd)) {
    AppendFileAction(file_action);
    return true;
  }
  return false;
}

bool ProcessLaunchInfo::AppendOpenFileAction(int fd, const FileSpec &file_spec,
                                             bool read, bool write) {
  FileAction file_action;
  if (file_action.Open(fd, file_spec, read, write)) {
    AppendFileAction(file_action);
    return true;
  }
  return false;
}

bool ProcessLaunchInfo::AppendSuppressFileAction(int fd, bool read,
                                                 bool write) {
  FileAction file_action;
  if (file_action.Open(fd, FileSpec(FileSystem::DEV_NULL), read, write)) {
    AppendFileAction(file_action);
    return true;
  }
  return false;
}

const FileAction *ProcessLaunchInfo::GetFileActionAtIndex(size_t idx) const {
  if (idx < m_file_actions.size())
    return &m_file_actions[idx];
  return nullptr;
}

const FileAction *ProcessLaunchInfo::GetFileActionForFD(int fd) const {
  for (size_t idx = 0, count = m_file_actions.size(); idx < count; ++idx) {
    if (m_file_actions[idx].GetFD() == fd)
      return &m_file_actions[idx];
  }
  return nullptr;
}

const FileSpec &ProcessLaunchInfo::GetWorkingDirectory() const {
  return m_working_dir;
}

void ProcessLaunchInfo::SetWorkingDirectory(const FileSpec &working_dir) {
  m_working_dir = working_dir;
}

llvm::StringRef ProcessLaunchInfo::GetProcessPluginName() const {
  return llvm::StringRef(m_plugin_name);
}

void ProcessLaunchInfo::SetProcessPluginName(llvm::StringRef plugin) {
  m_plugin_name = std::string(plugin);
}

const FileSpec &ProcessLaunchInfo::GetShell() const { return m_shell; }

void ProcessLaunchInfo::SetShell(const FileSpec &shell) {
  m_shell = shell;
  if (m_shell) {
    FileSystem::Instance().ResolveExecutableLocation(m_shell);
    m_flags.Set(lldb::eLaunchFlagLaunchInShell);
  } else
    m_flags.Clear(lldb::eLaunchFlagLaunchInShell);
}

void ProcessLaunchInfo::SetLaunchInSeparateProcessGroup(bool separate) {
  if (separate)
    m_flags.Set(lldb::eLaunchFlagLaunchInSeparateProcessGroup);
  else
    m_flags.Clear(lldb::eLaunchFlagLaunchInSeparateProcessGroup);
}

void ProcessLaunchInfo::SetShellExpandArguments(bool expand) {
  if (expand)
    m_flags.Set(lldb::eLaunchFlagShellExpandArguments);
  else
    m_flags.Clear(lldb::eLaunchFlagShellExpandArguments);
}

void ProcessLaunchInfo::Clear() {
  ProcessInfo::Clear();
  m_working_dir.Clear();
  m_plugin_name.clear();
  m_shell.Clear();
  m_flags.Clear();
  m_file_actions.clear();
  m_resume_count = 0;
  m_listener_sp.reset();
  m_hijack_listener_sp.reset();
}

void ProcessLaunchInfo::NoOpMonitorCallback(lldb::pid_t pid, int signal,
                                            int status) {
  Log *log = GetLog(LLDBLog::Process);
  LLDB_LOG(log, "pid = {0}, signal = {1}, status = {2}", pid, signal, status);
}

bool ProcessLaunchInfo::MonitorProcess() const {
  if (m_monitor_callback && ProcessIDIsValid()) {
    llvm::Expected<HostThread> maybe_thread =
        Host::StartMonitoringChildProcess(m_monitor_callback, GetProcessID());
    if (!maybe_thread)
      LLDB_LOG_ERROR(GetLog(LLDBLog::Host), maybe_thread.takeError(),
                     "failed to launch host thread: {0}");
    return true;
  }
  return false;
}

void ProcessLaunchInfo::SetDetachOnError(bool enable) {
  if (enable)
    m_flags.Set(lldb::eLaunchFlagDetachOnError);
  else
    m_flags.Clear(lldb::eLaunchFlagDetachOnError);
}

llvm::Error ProcessLaunchInfo::SetUpPtyRedirection() {
  Log *log = GetLog(LLDBLog::Process);

  bool stdin_free = GetFileActionForFD(STDIN_FILENO) == nullptr;
  bool stdout_free = GetFileActionForFD(STDOUT_FILENO) == nullptr;
  bool stderr_free = GetFileActionForFD(STDERR_FILENO) == nullptr;
  bool any_free = stdin_free || stdout_free || stderr_free;
  if (!any_free)
    return llvm::Error::success();

  LLDB_LOG(log, "Generating a pty to use for stdin/out/err");

  int open_flags = O_RDWR | O_NOCTTY;
#if !defined(_WIN32)
  // We really shouldn't be specifying platform specific flags that are
  // intended for a system call in generic code.  But this will have to
  // do for now.
  open_flags |= O_CLOEXEC;
#endif
  if (llvm::Error Err = m_pty->OpenFirstAvailablePrimary(open_flags))
    return Err;

  const FileSpec secondary_file_spec(m_pty->GetSecondaryName());

  if (stdin_free)
    AppendOpenFileAction(STDIN_FILENO, secondary_file_spec, true, false);

  if (stdout_free)
    AppendOpenFileAction(STDOUT_FILENO, secondary_file_spec, false, true);

  if (stderr_free)
    AppendOpenFileAction(STDERR_FILENO, secondary_file_spec, false, true);
  return llvm::Error::success();
}

bool ProcessLaunchInfo::ConvertArgumentsForLaunchingInShell(
    Status &error, bool will_debug, bool first_arg_is_full_shell_command,
    uint32_t num_resumes) {
  error.Clear();

  if (GetFlags().Test(eLaunchFlagLaunchInShell)) {
    if (m_shell) {
      std::string shell_executable = m_shell.GetPath();

      const char **argv = GetArguments().GetConstArgumentVector();
      if (argv == nullptr || argv[0] == nullptr)
        return false;
      Args shell_arguments;
      shell_arguments.AppendArgument(shell_executable);
      const llvm::Triple &triple = GetArchitecture().GetTriple();
      if (triple.getOS() == llvm::Triple::Win32 &&
          !triple.isWindowsCygwinEnvironment())
        shell_arguments.AppendArgument(llvm::StringRef("/C"));
      else
        shell_arguments.AppendArgument(llvm::StringRef("-c"));

      StreamString shell_command;
      if (will_debug) {
        // Add a modified PATH environment variable in case argv[0] is a
        // relative path.
        const char *argv0 = argv[0];
        FileSpec arg_spec(argv0);
        if (arg_spec.IsRelative()) {
          // We have a relative path to our executable which may not work if we
          // just try to run "a.out" (without it being converted to "./a.out")
          FileSpec working_dir = GetWorkingDirectory();
          // Be sure to put quotes around PATH's value in case any paths have
          // spaces...
          std::string new_path("PATH=\"");
          const size_t empty_path_len = new_path.size();

          if (working_dir) {
            new_path += working_dir.GetPath();
          } else {
            llvm::SmallString<64> cwd;
            if (! llvm::sys::fs::current_path(cwd))
              new_path += cwd;
          }
          std::string curr_path;
          if (HostInfo::GetEnvironmentVar("PATH", curr_path)) {
            if (new_path.size() > empty_path_len)
              new_path += ':';
            new_path += curr_path;
          }
          new_path += "\" ";
          shell_command.PutCString(new_path);
        }

        if (triple.getOS() != llvm::Triple::Win32 ||
            triple.isWindowsCygwinEnvironment())
          shell_command.PutCString("exec");

        // Only Apple supports /usr/bin/arch being able to specify the
        // architecture
        if (GetArchitecture().IsValid() && // Valid architecture
            GetArchitecture().GetTriple().getVendor() ==
                llvm::Triple::Apple && // Apple only
            GetArchitecture().GetCore() !=
                ArchSpec::eCore_x86_64_x86_64h) // Don't do this for x86_64h
        {
          shell_command.Printf(" /usr/bin/arch -arch %s",
                               GetArchitecture().GetArchitectureName());
          // Set the resume count to 2:
          // 1 - stop in shell
          // 2 - stop in /usr/bin/arch
          // 3 - then we will stop in our program
          SetResumeCount(num_resumes + 1);
        } else {
          // Set the resume count to 1:
          // 1 - stop in shell
          // 2 - then we will stop in our program
          SetResumeCount(num_resumes);
        }
      }

      if (first_arg_is_full_shell_command) {
        // There should only be one argument that is the shell command itself
        // to be used as is
        if (argv[0] && !argv[1])
          shell_command.Printf("%s", argv[0]);
        else
          return false;
      } else {
        for (size_t i = 0; argv[i] != nullptr; ++i) {
          std::string safe_arg = Args::GetShellSafeArgument(m_shell, argv[i]);
          if (safe_arg.empty())
            safe_arg = "\"\"";
          // Add a space to separate this arg from the previous one.
          shell_command.PutCString(" ");
          shell_command.PutCString(safe_arg);
        }
      }
      shell_arguments.AppendArgument(shell_command.GetString());
      m_executable = m_shell;
      m_arguments = shell_arguments;
      return true;
    } else {
      error = Status::FromErrorString("invalid shell path");
    }
  } else {
    error = Status::FromErrorString("not launching in shell");
  }
  return false;
}