ScriptInterpreter/Python/ScriptInterpreterPython.cpp

//===-- ScriptInterpreterPython.cpp -----------------------------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//

#ifdef LLDB_DISABLE_PYTHON

// Python is disabled in this build

#else

// LLDB Python header must be included first
#include "lldb-python.h"

#include "PythonDataObjects.h"
#include "PythonExceptionState.h"
#include "ScriptInterpreterPython.h"

#include <stdio.h>
#include <stdlib.h>

#include <memory>
#include <mutex>
#include <string>

#include "lldb/API/SBValue.h"
#include "lldb/API/SBFrame.h"
#include "lldb/Breakpoint/BreakpointLocation.h"
#include "lldb/Breakpoint/StoppointCallbackContext.h"
#include "lldb/Breakpoint/WatchpointOptions.h"
#include "lldb/Core/Communication.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/DataFormatters/TypeSummary.h"
#include "lldb/Host/ConnectionFileDescriptor.h"
#include "lldb/Host/FileSystem.h"
#include "lldb/Host/HostInfo.h"
#include "lldb/Host/Pipe.h"
#include "lldb/Interpreter/CommandInterpreter.h"
#include "lldb/Interpreter/CommandReturnObject.h"
#include "lldb/Target/Thread.h"
#include "lldb/Target/ThreadPlan.h"
#include "lldb/Utility/Timer.h"

#if defined(_WIN32)
#include "lldb/Host/windows/ConnectionGenericFileWindows.h"
#endif

#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/FileSystem.h"

using namespace lldb;
using namespace lldb_private;

#ifndef LLDB_DISABLE_PYTHON

// Defined in the SWIG source file
#if PY_MAJOR_VERSION >= 3
extern "C" PyObject *PyInit__lldb(void);

#define LLDBSwigPyInit PyInit__lldb

#else
extern "C" void init_lldb(void);

#define LLDBSwigPyInit init_lldb
#endif

// These prototypes are the Pythonic implementations of the required callbacks.
// Although these are scripting-language specific, their definition depends on
// the public API.
extern "C" bool LLDBSwigPythonBreakpointCallbackFunction(
    const char *python_function_name, const char *session_dictionary_name,
    const lldb::StackFrameSP &sb_frame,
    const lldb::BreakpointLocationSP &sb_bp_loc);

extern "C" bool LLDBSwigPythonWatchpointCallbackFunction(
    const char *python_function_name, const char *session_dictionary_name,
    const lldb::StackFrameSP &sb_frame, const lldb::WatchpointSP &sb_wp);

extern "C" bool LLDBSwigPythonCallTypeScript(
    const char *python_function_name, void *session_dictionary,
    const lldb::ValueObjectSP &valobj_sp, void **pyfunct_wrapper,
    const lldb::TypeSummaryOptionsSP &options_sp, std::string &retval);

extern "C" void *
LLDBSwigPythonCreateSyntheticProvider(const char *python_class_name,
                                      const char *session_dictionary_name,
                                      const lldb::ValueObjectSP &valobj_sp);

extern "C" void *
LLDBSwigPythonCreateCommandObject(const char *python_class_name,
                                  const char *session_dictionary_name,
                                  const lldb::DebuggerSP debugger_sp);

extern "C" void *LLDBSwigPythonCreateScriptedThreadPlan(
    const char *python_class_name, const char *session_dictionary_name,
    const lldb::ThreadPlanSP &thread_plan_sp);

extern "C" bool LLDBSWIGPythonCallThreadPlan(void *implementor,
                                             const char *method_name,
                                             Event *event_sp, bool &got_error);

extern "C" void *LLDBSwigPythonCreateScriptedBreakpointResolver(
    const char *python_class_name, const char *session_dictionary_name,
    lldb_private::StructuredDataImpl *args, lldb::BreakpointSP &bkpt_sp);

extern "C" unsigned int
LLDBSwigPythonCallBreakpointResolver(void *implementor, const char *method_name,
                                     lldb_private::SymbolContext *sym_ctx);

extern "C" size_t LLDBSwigPython_CalculateNumChildren(void *implementor,
                                                      uint32_t max);

extern "C" void *LLDBSwigPython_GetChildAtIndex(void *implementor,
                                                uint32_t idx);

extern "C" int LLDBSwigPython_GetIndexOfChildWithName(void *implementor,
                                                      const char *child_name);

extern "C" void *LLDBSWIGPython_CastPyObjectToSBValue(void *data);

extern lldb::ValueObjectSP
LLDBSWIGPython_GetValueObjectSPFromSBValue(void *data);

extern "C" bool LLDBSwigPython_UpdateSynthProviderInstance(void *implementor);

extern "C" bool
LLDBSwigPython_MightHaveChildrenSynthProviderInstance(void *implementor);

extern "C" void *
LLDBSwigPython_GetValueSynthProviderInstance(void *implementor);

extern "C" bool
LLDBSwigPythonCallCommand(const char *python_function_name,
                          const char *session_dictionary_name,
                          lldb::DebuggerSP &debugger, const char *args,
                          lldb_private::CommandReturnObject &cmd_retobj,
                          lldb::ExecutionContextRefSP exe_ctx_ref_sp);

extern "C" bool
LLDBSwigPythonCallCommandObject(void *implementor, lldb::DebuggerSP &debugger,
                                const char *args,
                                lldb_private::CommandReturnObject &cmd_retobj,
                                lldb::ExecutionContextRefSP exe_ctx_ref_sp);

extern "C" bool
LLDBSwigPythonCallModuleInit(const char *python_module_name,
                             const char *session_dictionary_name,
                             lldb::DebuggerSP &debugger);

extern "C" void *
LLDBSWIGPythonCreateOSPlugin(const char *python_class_name,
                             const char *session_dictionary_name,
                             const lldb::ProcessSP &process_sp);

extern "C" void *
LLDBSWIGPython_CreateFrameRecognizer(const char *python_class_name,
                                     const char *session_dictionary_name);

extern "C" void *
LLDBSwigPython_GetRecognizedArguments(void *implementor,
                                      const lldb::StackFrameSP &frame_sp);

extern "C" bool LLDBSWIGPythonRunScriptKeywordProcess(
    const char *python_function_name, const char *session_dictionary_name,
    lldb::ProcessSP &process, std::string &output);

extern "C" bool LLDBSWIGPythonRunScriptKeywordThread(
    const char *python_function_name, const char *session_dictionary_name,
    lldb::ThreadSP &thread, std::string &output);

extern "C" bool LLDBSWIGPythonRunScriptKeywordTarget(
    const char *python_function_name, const char *session_dictionary_name,
    lldb::TargetSP &target, std::string &output);

extern "C" bool LLDBSWIGPythonRunScriptKeywordFrame(
    const char *python_function_name, const char *session_dictionary_name,
    lldb::StackFrameSP &frame, std::string &output);

extern "C" bool LLDBSWIGPythonRunScriptKeywordValue(
    const char *python_function_name, const char *session_dictionary_name,
    lldb::ValueObjectSP &value, std::string &output);

extern "C" void *
LLDBSWIGPython_GetDynamicSetting(void *module, const char *setting,
                                 const lldb::TargetSP &target_sp);

#endif

static bool g_initialized = false;

namespace {

// Initializing Python is not a straightforward process.  We cannot control
// what external code may have done before getting to this point in LLDB,
// including potentially having already initialized Python, so we need to do a
// lot of work to ensure that the existing state of the system is maintained
// across our initialization.  We do this by using an RAII pattern where we
// save off initial state at the beginning, and restore it at the end
struct InitializePythonRAII {
public:
  InitializePythonRAII()
      : m_gil_state(PyGILState_UNLOCKED), m_was_already_initialized(false) {
    // Python will muck with STDIN terminal state, so save off any current TTY
    // settings so we can restore them.
    m_stdin_tty_state.Save(STDIN_FILENO, false);

    InitializePythonHome();

    // Register _lldb as a built-in module.
    PyImport_AppendInittab("_lldb", LLDBSwigPyInit);

// Python < 3.2 and Python >= 3.2 reversed the ordering requirements for
// calling `Py_Initialize` and `PyEval_InitThreads`.  < 3.2 requires that you
// call `PyEval_InitThreads` first, and >= 3.2 requires that you call it last.
#if (PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 2) || (PY_MAJOR_VERSION > 3)
    Py_InitializeEx(0);
    InitializeThreadsPrivate();
#else
    InitializeThreadsPrivate();
    Py_InitializeEx(0);
#endif
  }

  ~InitializePythonRAII() {
    if (m_was_already_initialized) {
      Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SCRIPT));
      LLDB_LOGV(log, "Releasing PyGILState. Returning to state = {0}locked",
                m_gil_state == PyGILState_UNLOCKED ? "un" : "");
      PyGILState_Release(m_gil_state);
    } else {
      // We initialized the threads in this function, just unlock the GIL.
      PyEval_SaveThread();
    }

    m_stdin_tty_state.Restore();
  }

private:
  void InitializePythonHome() {
#if defined(LLDB_PYTHON_HOME)
#if PY_MAJOR_VERSION >= 3
    size_t size = 0;
    static wchar_t *g_python_home = Py_DecodeLocale(LLDB_PYTHON_HOME, &size);
#else
    static char g_python_home[] = LLDB_PYTHON_HOME;
#endif
    Py_SetPythonHome(g_python_home);
#else
#if defined(__APPLE__) && PY_MAJOR_VERSION == 2 && PY_MINOR_VERSION == 7
    // For Darwin, the only Python version supported is the one shipped in the OS
    // OS and linked with lldb. Other installation of Python may have higher
    // priorities in the path, overriding PYTHONHOME and causing
    // problems/incompatibilities. In order to avoid confusion, always hardcode
    // the PythonHome to be right, as it's not going to change.
    static char path[] = "/System/Library/Frameworks/Python.framework/Versions/2.7";
    Py_SetPythonHome(path);
#endif
#endif
  }

  void InitializeThreadsPrivate() {
// Since Python 3.7 `Py_Initialize` calls `PyEval_InitThreads` inside itself,
// so there is no way to determine whether the embedded interpreter
// was already initialized by some external code. `PyEval_ThreadsInitialized`
// would always return `true` and `PyGILState_Ensure/Release` flow would be
// executed instead of unlocking GIL with `PyEval_SaveThread`. When
// an another thread calls `PyGILState_Ensure` it would get stuck in deadlock.
#if (PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 7) || (PY_MAJOR_VERSION > 3)
// The only case we should go further and acquire the GIL: it is unlocked.
    if (PyGILState_Check())
      return;
#endif

    if (PyEval_ThreadsInitialized()) {
      Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SCRIPT));

      m_was_already_initialized = true;
      m_gil_state = PyGILState_Ensure();
      LLDB_LOGV(log, "Ensured PyGILState. Previous state = {0}locked\n",
                m_gil_state == PyGILState_UNLOCKED ? "un" : "");
      return;
    }

    // InitThreads acquires the GIL if it hasn't been called before.
    PyEval_InitThreads();
  }

  TerminalState m_stdin_tty_state;
  PyGILState_STATE m_gil_state;
  bool m_was_already_initialized;
};
}

ScriptInterpreterPython::Locker::Locker(ScriptInterpreterPython *py_interpreter,
                                        uint16_t on_entry, uint16_t on_leave,
                                        FILE *in, FILE *out, FILE *err)
    : ScriptInterpreterLocker(),
      m_teardown_session((on_leave & TearDownSession) == TearDownSession),
      m_python_interpreter(py_interpreter) {
  DoAcquireLock();
  if ((on_entry & InitSession) == InitSession) {
    if (!DoInitSession(on_entry, in, out, err)) {
      // Don't teardown the session if we didn't init it.
      m_teardown_session = false;
    }
  }
}

bool ScriptInterpreterPython::Locker::DoAcquireLock() {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SCRIPT));
  m_GILState = PyGILState_Ensure();
  LLDB_LOGV(log, "Ensured PyGILState. Previous state = {0}locked",
            m_GILState == PyGILState_UNLOCKED ? "un" : "");

  // we need to save the thread state when we first start the command because
  // we might decide to interrupt it while some action is taking place outside
  // of Python (e.g. printing to screen, waiting for the network, ...) in that
  // case, _PyThreadState_Current will be NULL - and we would be unable to set
  // the asynchronous exception - not a desirable situation
  m_python_interpreter->SetThreadState(PyThreadState_Get());
  m_python_interpreter->IncrementLockCount();
  return true;
}

bool ScriptInterpreterPython::Locker::DoInitSession(uint16_t on_entry_flags,
                                                    FILE *in, FILE *out,
                                                    FILE *err) {
  if (!m_python_interpreter)
    return false;
  return m_python_interpreter->EnterSession(on_entry_flags, in, out, err);
}

bool ScriptInterpreterPython::Locker::DoFreeLock() {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SCRIPT));
  LLDB_LOGV(log, "Releasing PyGILState. Returning to state = {0}locked",
            m_GILState == PyGILState_UNLOCKED ? "un" : "");
  PyGILState_Release(m_GILState);
  m_python_interpreter->DecrementLockCount();
  return true;
}

bool ScriptInterpreterPython::Locker::DoTearDownSession() {
  if (!m_python_interpreter)
    return false;
  m_python_interpreter->LeaveSession();
  return true;
}

ScriptInterpreterPython::Locker::~Locker() {
  if (m_teardown_session)
    DoTearDownSession();
  DoFreeLock();
}

ScriptInterpreterPython::ScriptInterpreterPython(
    CommandInterpreter &interpreter)
    : ScriptInterpreter(interpreter, eScriptLanguagePython),
      IOHandlerDelegateMultiline("DONE"), m_saved_stdin(), m_saved_stdout(),
      m_saved_stderr(), m_main_module(), m_lldb_module(),
      m_session_dict(PyInitialValue::Invalid),
      m_sys_module_dict(PyInitialValue::Invalid), m_run_one_line_function(),
      m_run_one_line_str_global(),
      m_dictionary_name(
          interpreter.GetDebugger().GetInstanceName().AsCString()),
      m_terminal_state(), m_active_io_handler(eIOHandlerNone),
      m_session_is_active(false), m_pty_slave_is_open(false),
      m_valid_session(true), m_lock_count(0), m_command_thread_state(nullptr) {
  InitializePrivate();

  m_dictionary_name.append("_dict");
  StreamString run_string;
  run_string.Printf("%s = dict()", m_dictionary_name.c_str());

  Locker locker(this, ScriptInterpreterPython::Locker::AcquireLock,
                ScriptInterpreterPython::Locker::FreeAcquiredLock);
  PyRun_SimpleString(run_string.GetData());

  run_string.Clear();
  run_string.Printf(
      "run_one_line (%s, 'import copy, keyword, os, re, sys, uuid, lldb')",
      m_dictionary_name.c_str());
  PyRun_SimpleString(run_string.GetData());

  // Reloading modules requires a different syntax in Python 2 and Python 3.
  // This provides a consistent syntax no matter what version of Python.
  run_string.Clear();
  run_string.Printf("run_one_line (%s, 'from six.moves import reload_module')",
                    m_dictionary_name.c_str());
  PyRun_SimpleString(run_string.GetData());

  // WARNING: temporary code that loads Cocoa formatters - this should be done
  // on a per-platform basis rather than loading the whole set and letting the
  // individual formatter classes exploit APIs to check whether they can/cannot
  // do their task
  run_string.Clear();
  run_string.Printf(
      "run_one_line (%s, 'import lldb.formatters, lldb.formatters.cpp, pydoc')",
      m_dictionary_name.c_str());
  PyRun_SimpleString(run_string.GetData());
  run_string.Clear();

  run_string.Printf("run_one_line (%s, 'import lldb.embedded_interpreter; from "
                    "lldb.embedded_interpreter import run_python_interpreter; "
                    "from lldb.embedded_interpreter import run_one_line')",
                    m_dictionary_name.c_str());
  PyRun_SimpleString(run_string.GetData());
  run_string.Clear();

  run_string.Printf("run_one_line (%s, 'lldb.debugger_unique_id = %" PRIu64
                    "; pydoc.pager = pydoc.plainpager')",
                    m_dictionary_name.c_str(),
                    interpreter.GetDebugger().GetID());
  PyRun_SimpleString(run_string.GetData());
}

ScriptInterpreterPython::~ScriptInterpreterPython() {
  // the session dictionary may hold objects with complex state which means
  // that they may need to be torn down with some level of smarts and that, in
  // turn, requires a valid thread state force Python to procure itself such a
  // thread state, nuke the session dictionary and then release it for others
  // to use and proceed with the rest of the shutdown
  auto gil_state = PyGILState_Ensure();
  m_session_dict.Reset();
  PyGILState_Release(gil_state);
}

void ScriptInterpreterPython::Initialize() {
  static llvm::once_flag g_once_flag;

  llvm::call_once(g_once_flag, []() {
    PluginManager::RegisterPlugin(GetPluginNameStatic(),
                                  GetPluginDescriptionStatic(),
                                  lldb::eScriptLanguagePython, CreateInstance);
  });
}

void ScriptInterpreterPython::Terminate() {}

lldb::ScriptInterpreterSP
ScriptInterpreterPython::CreateInstance(CommandInterpreter &interpreter) {
  return std::make_shared<ScriptInterpreterPython>(interpreter);
}

lldb_private::ConstString ScriptInterpreterPython::GetPluginNameStatic() {
  static ConstString g_name("script-python");
  return g_name;
}

const char *ScriptInterpreterPython::GetPluginDescriptionStatic() {
  return "Embedded Python interpreter";
}

void ScriptInterpreterPython::ComputePythonDirForApple(
    llvm::SmallVectorImpl<char> &path) {
  auto style = llvm::sys::path::Style::posix;

  llvm::StringRef path_ref(path.begin(), path.size());
  auto rbegin = llvm::sys::path::rbegin(path_ref, style);
  auto rend = llvm::sys::path::rend(path_ref);
  auto framework = std::find(rbegin, rend, "LLDB.framework");
  if (framework == rend) {
    ComputePythonDirForPosix(path);
    return;
  }
  path.resize(framework - rend);
  llvm::sys::path::append(path, style, "LLDB.framework", "Resources", "Python");
}

void ScriptInterpreterPython::ComputePythonDirForPosix(
    llvm::SmallVectorImpl<char> &path) {
  auto style = llvm::sys::path::Style::posix;
#if defined(LLDB_PYTHON_RELATIVE_LIBDIR)
  // Build the path by backing out of the lib dir, then building with whatever
  // the real python interpreter uses.  (e.g. lib for most, lib64 on RHEL
  // x86_64).
  llvm::sys::path::remove_filename(path, style);
  llvm::sys::path::append(path, style, LLDB_PYTHON_RELATIVE_LIBDIR);
#else
  llvm::sys::path::append(path, style,
                          "python" + llvm::Twine(PY_MAJOR_VERSION) + "." +
                              llvm::Twine(PY_MINOR_VERSION),
                          "site-packages");
#endif
}

void ScriptInterpreterPython::ComputePythonDirForWindows(
    llvm::SmallVectorImpl<char> &path) {
  auto style = llvm::sys::path::Style::windows;
  llvm::sys::path::remove_filename(path, style);
  llvm::sys::path::append(path, style, "lib", "site-packages");

  // This will be injected directly through FileSpec.GetDirectory().SetString(),
  // so we need to normalize manually.
  std::replace(path.begin(), path.end(), '\\', '/');
}

FileSpec ScriptInterpreterPython::GetPythonDir() {
  static FileSpec g_spec = []() {
    FileSpec spec = HostInfo::GetShlibDir();
    if (!spec)
      return FileSpec();
    llvm::SmallString<64> path;
    spec.GetPath(path);

#if defined(__APPLE__)
    ComputePythonDirForApple(path);
#elif defined(_WIN32)
    ComputePythonDirForWindows(path);
#else
    ComputePythonDirForPosix(path);
#endif
    spec.GetDirectory().SetString(path);
    return spec;
  }();
  return g_spec;
}

lldb_private::ConstString ScriptInterpreterPython::GetPluginName() {
  return GetPluginNameStatic();
}

uint32_t ScriptInterpreterPython::GetPluginVersion() { return 1; }

void ScriptInterpreterPython::IOHandlerActivated(IOHandler &io_handler, bool interactive) {
  const char *instructions = nullptr;

  switch (m_active_io_handler) {
  case eIOHandlerNone:
    break;
  case eIOHandlerBreakpoint:
    instructions = R"(Enter your Python command(s). Type 'DONE' to end.
def function (frame, bp_loc, internal_dict):
    """frame: the lldb.SBFrame for the location at which you stopped
       bp_loc: an lldb.SBBreakpointLocation for the breakpoint location information
       internal_dict: an LLDB support object not to be used"""
)";
    break;
  case eIOHandlerWatchpoint:
    instructions = "Enter your Python command(s). Type 'DONE' to end.\n";
    break;
  }

  if (instructions) {
    StreamFileSP output_sp(io_handler.GetOutputStreamFile());
    if (output_sp && interactive) {
      output_sp->PutCString(instructions);
      output_sp->Flush();
    }
  }
}

void ScriptInterpreterPython::IOHandlerInputComplete(IOHandler &io_handler,
                                                     std::string &data) {
  io_handler.SetIsDone(true);
  bool batch_mode = m_interpreter.GetBatchCommandMode();

  switch (m_active_io_handler) {
  case eIOHandlerNone:
    break;
  case eIOHandlerBreakpoint: {
    std::vector<BreakpointOptions *> *bp_options_vec =
        (std::vector<BreakpointOptions *> *)io_handler.GetUserData();
    for (auto bp_options : *bp_options_vec) {
      if (!bp_options)
        continue;

      auto data_up = llvm::make_unique<CommandDataPython>();
      if (!data_up)
        break;
      data_up->user_source.SplitIntoLines(data);

      if (GenerateBreakpointCommandCallbackData(data_up->user_source,
                                                data_up->script_source)
              .Success()) {
        auto baton_sp = std::make_shared<BreakpointOptions::CommandBaton>(
            std::move(data_up));
        bp_options->SetCallback(
            ScriptInterpreterPython::BreakpointCallbackFunction, baton_sp);
      } else if (!batch_mode) {
        StreamFileSP error_sp = io_handler.GetErrorStreamFile();
        if (error_sp) {
          error_sp->Printf("Warning: No command attached to breakpoint.\n");
          error_sp->Flush();
        }
      }
    }
    m_active_io_handler = eIOHandlerNone;
  } break;
  case eIOHandlerWatchpoint: {
    WatchpointOptions *wp_options =
        (WatchpointOptions *)io_handler.GetUserData();
    auto data_up = llvm::make_unique<WatchpointOptions::CommandData>();
    data_up->user_source.SplitIntoLines(data);

    if (GenerateWatchpointCommandCallbackData(data_up->user_source,
                                              data_up->script_source)) {
      auto baton_sp =
          std::make_shared<WatchpointOptions::CommandBaton>(std::move(data_up));
      wp_options->SetCallback(
          ScriptInterpreterPython::WatchpointCallbackFunction, baton_sp);
    } else if (!batch_mode) {
      StreamFileSP error_sp = io_handler.GetErrorStreamFile();
      if (error_sp) {
        error_sp->Printf("Warning: No command attached to breakpoint.\n");
        error_sp->Flush();
      }
    }
    m_active_io_handler = eIOHandlerNone;
  } break;
  }
}

void ScriptInterpreterPython::ResetOutputFileHandle(FILE *fh) {}

void ScriptInterpreterPython::SaveTerminalState(int fd) {
  // Python mucks with the terminal state of STDIN. If we can possibly avoid
  // this by setting the file handles up correctly prior to entering the
  // interpreter we should. For now we save and restore the terminal state on
  // the input file handle.
  m_terminal_state.Save(fd, false);
}

void ScriptInterpreterPython::RestoreTerminalState() {
  // Python mucks with the terminal state of STDIN. If we can possibly avoid
  // this by setting the file handles up correctly prior to entering the
  // interpreter we should. For now we save and restore the terminal state on
  // the input file handle.
  m_terminal_state.Restore();
}

void ScriptInterpreterPython::LeaveSession() {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SCRIPT));
  if (log)
    log->PutCString("ScriptInterpreterPython::LeaveSession()");

  // checking that we have a valid thread state - since we use our own
  // threading and locking in some (rare) cases during cleanup Python may end
  // up believing we have no thread state and PyImport_AddModule will crash if
  // that is the case - since that seems to only happen when destroying the
  // SBDebugger, we can make do without clearing up stdout and stderr

  // rdar://problem/11292882
  // When the current thread state is NULL, PyThreadState_Get() issues a fatal
  // error.
  if (PyThreadState_GetDict()) {
    PythonDictionary &sys_module_dict = GetSysModuleDictionary();
    if (sys_module_dict.IsValid()) {
      if (m_saved_stdin.IsValid()) {
        sys_module_dict.SetItemForKey(PythonString("stdin"), m_saved_stdin);
        m_saved_stdin.Reset();
      }
      if (m_saved_stdout.IsValid()) {
        sys_module_dict.SetItemForKey(PythonString("stdout"), m_saved_stdout);
        m_saved_stdout.Reset();
      }
      if (m_saved_stderr.IsValid()) {
        sys_module_dict.SetItemForKey(PythonString("stderr"), m_saved_stderr);
        m_saved_stderr.Reset();
      }
    }
  }

  m_session_is_active = false;
}

bool ScriptInterpreterPython::SetStdHandle(File &file, const char *py_name,
                                           PythonFile &save_file,
                                           const char *mode) {
  if (file.IsValid()) {
    // Flush the file before giving it to python to avoid interleaved output.
    file.Flush();

    PythonDictionary &sys_module_dict = GetSysModuleDictionary();

    save_file = sys_module_dict.GetItemForKey(PythonString(py_name))
                    .AsType<PythonFile>();

    PythonFile new_file(file, mode);
    sys_module_dict.SetItemForKey(PythonString(py_name), new_file);
    return true;
  } else
    save_file.Reset();
  return false;
}

bool ScriptInterpreterPython::EnterSession(uint16_t on_entry_flags, FILE *in,
                                           FILE *out, FILE *err) {
  // If we have already entered the session, without having officially 'left'
  // it, then there is no need to 'enter' it again.
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SCRIPT));
  if (m_session_is_active) {
    if (log)
      log->Printf(
          "ScriptInterpreterPython::EnterSession(on_entry_flags=0x%" PRIx16
          ") session is already active, returning without doing anything",
          on_entry_flags);
    return false;
  }

  if (log)
    log->Printf(
        "ScriptInterpreterPython::EnterSession(on_entry_flags=0x%" PRIx16 ")",
        on_entry_flags);

  m_session_is_active = true;

  StreamString run_string;

  if (on_entry_flags & Locker::InitGlobals) {
    run_string.Printf("run_one_line (%s, 'lldb.debugger_unique_id = %" PRIu64,
                      m_dictionary_name.c_str(),
                      GetCommandInterpreter().GetDebugger().GetID());
    run_string.Printf(
        "; lldb.debugger = lldb.SBDebugger.FindDebuggerWithID (%" PRIu64 ")",
        GetCommandInterpreter().GetDebugger().GetID());
    run_string.PutCString("; lldb.target = lldb.debugger.GetSelectedTarget()");
    run_string.PutCString("; lldb.process = lldb.target.GetProcess()");
    run_string.PutCString("; lldb.thread = lldb.process.GetSelectedThread ()");
    run_string.PutCString("; lldb.frame = lldb.thread.GetSelectedFrame ()");
    run_string.PutCString("')");
  } else {
    // If we aren't initing the globals, we should still always set the
    // debugger (since that is always unique.)
    run_string.Printf("run_one_line (%s, 'lldb.debugger_unique_id = %" PRIu64,
                      m_dictionary_name.c_str(),
                      GetCommandInterpreter().GetDebugger().GetID());
    run_string.Printf(
        "; lldb.debugger = lldb.SBDebugger.FindDebuggerWithID (%" PRIu64 ")",
        GetCommandInterpreter().GetDebugger().GetID());
    run_string.PutCString("')");
  }

  PyRun_SimpleString(run_string.GetData());
  run_string.Clear();

  PythonDictionary &sys_module_dict = GetSysModuleDictionary();
  if (sys_module_dict.IsValid()) {
    File in_file(in, false);
    File out_file(out, false);
    File err_file(err, false);

    lldb::StreamFileSP in_sp;
    lldb::StreamFileSP out_sp;
    lldb::StreamFileSP err_sp;
    if (!in_file.IsValid() || !out_file.IsValid() || !err_file.IsValid())
      m_interpreter.GetDebugger().AdoptTopIOHandlerFilesIfInvalid(in_sp, out_sp,
                                                                  err_sp);

    if (on_entry_flags & Locker::NoSTDIN) {
      m_saved_stdin.Reset();
    } else {
      if (!SetStdHandle(in_file, "stdin", m_saved_stdin, "r")) {
        if (in_sp)
          SetStdHandle(in_sp->GetFile(), "stdin", m_saved_stdin, "r");
      }
    }

    if (!SetStdHandle(out_file, "stdout", m_saved_stdout, "w")) {
      if (out_sp)
        SetStdHandle(out_sp->GetFile(), "stdout", m_saved_stdout, "w");
    }

    if (!SetStdHandle(err_file, "stderr", m_saved_stderr, "w")) {
      if (err_sp)
        SetStdHandle(err_sp->GetFile(), "stderr", m_saved_stderr, "w");
    }
  }

  if (PyErr_Occurred())
    PyErr_Clear();

  return true;
}

PythonObject &ScriptInterpreterPython::GetMainModule() {
  if (!m_main_module.IsValid())
    m_main_module.Reset(PyRefType::Borrowed, PyImport_AddModule("__main__"));
  return m_main_module;
}

PythonDictionary &ScriptInterpreterPython::GetSessionDictionary() {
  if (m_session_dict.IsValid())
    return m_session_dict;

  PythonObject &main_module = GetMainModule();
  if (!main_module.IsValid())
    return m_session_dict;

  PythonDictionary main_dict(PyRefType::Borrowed,
                             PyModule_GetDict(main_module.get()));
  if (!main_dict.IsValid())
    return m_session_dict;

  PythonObject item = main_dict.GetItemForKey(PythonString(m_dictionary_name));
  m_session_dict.Reset(PyRefType::Borrowed, item.get());
  return m_session_dict;
}

PythonDictionary &ScriptInterpreterPython::GetSysModuleDictionary() {
  if (m_sys_module_dict.IsValid())
    return m_sys_module_dict;

  PythonObject sys_module(PyRefType::Borrowed, PyImport_AddModule("sys"));
  if (sys_module.IsValid())
    m_sys_module_dict.Reset(PyRefType::Borrowed,
                            PyModule_GetDict(sys_module.get()));
  return m_sys_module_dict;
}

static std::string GenerateUniqueName(const char *base_name_wanted,
                                      uint32_t &functions_counter,
                                      const void *name_token = nullptr) {
  StreamString sstr;

  if (!base_name_wanted)
    return std::string();

  if (!name_token)
    sstr.Printf("%s_%d", base_name_wanted, functions_counter++);
  else
    sstr.Printf("%s_%p", base_name_wanted, name_token);

  return sstr.GetString();
}

bool ScriptInterpreterPython::GetEmbeddedInterpreterModuleObjects() {
  if (m_run_one_line_function.IsValid())
    return true;

  PythonObject module(PyRefType::Borrowed,
                      PyImport_AddModule("lldb.embedded_interpreter"));
  if (!module.IsValid())
    return false;

  PythonDictionary module_dict(PyRefType::Borrowed,
                               PyModule_GetDict(module.get()));
  if (!module_dict.IsValid())
    return false;

  m_run_one_line_function =
      module_dict.GetItemForKey(PythonString("run_one_line"));
  m_run_one_line_str_global =
      module_dict.GetItemForKey(PythonString("g_run_one_line_str"));
  return m_run_one_line_function.IsValid();
}

static void ReadThreadBytesReceived(void *baton, const void *src,
                                    size_t src_len) {
  if (src && src_len) {
    Stream *strm = (Stream *)baton;
    strm->Write(src, src_len);
    strm->Flush();
  }
}

bool ScriptInterpreterPython::ExecuteOneLine(
    llvm::StringRef command, CommandReturnObject *result,
    const ExecuteScriptOptions &options) {
  std::string command_str = command.str();

  if (!m_valid_session)
    return false;

  if (!command.empty()) {
    // We want to call run_one_line, passing in the dictionary and the command
    // string.  We cannot do this through PyRun_SimpleString here because the
    // command string may contain escaped characters, and putting it inside
    // another string to pass to PyRun_SimpleString messes up the escaping.  So
    // we use the following more complicated method to pass the command string
    // directly down to Python.
    Debugger &debugger = m_interpreter.GetDebugger();

    StreamFileSP input_file_sp;
    StreamFileSP output_file_sp;
    StreamFileSP error_file_sp;
    Communication output_comm(
        "lldb.ScriptInterpreterPython.ExecuteOneLine.comm");
    bool join_read_thread = false;
    if (options.GetEnableIO()) {
      if (result) {
        input_file_sp = debugger.GetInputFile();
        // Set output to a temporary file so we can forward the results on to
        // the result object

        Pipe pipe;
        Status pipe_result = pipe.CreateNew(false);
        if (pipe_result.Success()) {
#if defined(_WIN32)
          lldb::file_t read_file = pipe.GetReadNativeHandle();
          pipe.ReleaseReadFileDescriptor();
          std::unique_ptr<ConnectionGenericFile> conn_up(
              new ConnectionGenericFile(read_file, true));
#else
          std::unique_ptr<ConnectionFileDescriptor> conn_up(
              new ConnectionFileDescriptor(pipe.ReleaseReadFileDescriptor(),
                                           true));
#endif
          if (conn_up->IsConnected()) {
            output_comm.SetConnection(conn_up.release());
            output_comm.SetReadThreadBytesReceivedCallback(
                ReadThreadBytesReceived, &result->GetOutputStream());
            output_comm.StartReadThread();
            join_read_thread = true;
            FILE *outfile_handle =
                fdopen(pipe.ReleaseWriteFileDescriptor(), "w");
            output_file_sp = std::make_shared<StreamFile>(outfile_handle, true);
            error_file_sp = output_file_sp;
            if (outfile_handle)
              ::setbuf(outfile_handle, nullptr);

            result->SetImmediateOutputFile(
                debugger.GetOutputFile()->GetFile().GetStream());
            result->SetImmediateErrorFile(
                debugger.GetErrorFile()->GetFile().GetStream());
          }
        }
      }
      if (!input_file_sp || !output_file_sp || !error_file_sp)
        debugger.AdoptTopIOHandlerFilesIfInvalid(input_file_sp, output_file_sp,
                                                 error_file_sp);
    } else {
      input_file_sp = std::make_shared<StreamFile>();
      FileSystem::Instance().Open(input_file_sp->GetFile(),
                                  FileSpec(FileSystem::DEV_NULL),
                                  File::eOpenOptionRead);

      output_file_sp = std::make_shared<StreamFile>();
      FileSystem::Instance().Open(output_file_sp->GetFile(),
                                  FileSpec(FileSystem::DEV_NULL),
                                  File::eOpenOptionWrite);

      error_file_sp = output_file_sp;
    }

    FILE *in_file = input_file_sp->GetFile().GetStream();
    FILE *out_file = output_file_sp->GetFile().GetStream();
    FILE *err_file = error_file_sp->GetFile().GetStream();
    bool success = false;
    {
      // WARNING!  It's imperative that this RAII scope be as tight as
      // possible. In particular, the scope must end *before* we try to join
      // the read thread.  The reason for this is that a pre-requisite for
      // joining the read thread is that we close the write handle (to break
      // the pipe and cause it to wake up and exit).  But acquiring the GIL as
      // below will redirect Python's stdio to use this same handle.  If we
      // close the handle while Python is still using it, bad things will
      // happen.
      Locker locker(
          this,
          ScriptInterpreterPython::Locker::AcquireLock |
              ScriptInterpreterPython::Locker::InitSession |
              (options.GetSetLLDBGlobals()
                   ? ScriptInterpreterPython::Locker::InitGlobals
                   : 0) |
              ((result && result->GetInteractive()) ? 0 : Locker::NoSTDIN),
          ScriptInterpreterPython::Locker::FreeAcquiredLock |
              ScriptInterpreterPython::Locker::TearDownSession,
          in_file, out_file, err_file);

      // Find the correct script interpreter dictionary in the main module.
      PythonDictionary &session_dict = GetSessionDictionary();
      if (session_dict.IsValid()) {
        if (GetEmbeddedInterpreterModuleObjects()) {
          if (PyCallable_Check(m_run_one_line_function.get())) {
            PythonObject pargs(
                PyRefType::Owned,
                Py_BuildValue("(Os)", session_dict.get(), command_str.c_str()));
            if (pargs.IsValid()) {
              PythonObject return_value(
                  PyRefType::Owned,
                  PyObject_CallObject(m_run_one_line_function.get(),
                                      pargs.get()));
              if (return_value.IsValid())
                success = true;
              else if (options.GetMaskoutErrors() && PyErr_Occurred()) {
                PyErr_Print();
                PyErr_Clear();
              }
            }
          }
        }
      }

      // Flush our output and error file handles
      ::fflush(out_file);
      if (out_file != err_file)
        ::fflush(err_file);
    }

    if (join_read_thread) {
      // Close the write end of the pipe since we are done with our one line
      // script. This should cause the read thread that output_comm is using to
      // exit
      output_file_sp->GetFile().Close();
      // The close above should cause this thread to exit when it gets to the
      // end of file, so let it get all its data
      output_comm.JoinReadThread();
      // Now we can close the read end of the pipe
      output_comm.Disconnect();
    }

    if (success)
      return true;

    // The one-liner failed.  Append the error message.
    if (result) {
      result->AppendErrorWithFormat(
          "python failed attempting to evaluate '%s'\n", command_str.c_str());
    }
    return false;
  }

  if (result)
    result->AppendError("empty command passed to python\n");
  return false;
}

class IOHandlerPythonInterpreter : public IOHandler {
public:
  IOHandlerPythonInterpreter(Debugger &debugger,
                             ScriptInterpreterPython *python)
      : IOHandler(debugger, IOHandler::Type::PythonInterpreter),
        m_python(python) {}

  ~IOHandlerPythonInterpreter() override {}

  ConstString GetControlSequence(char ch) override {
    if (ch == 'd')
      return ConstString("quit()\n");
    return ConstString();
  }

  void Run() override {
    if (m_python) {
      int stdin_fd = GetInputFD();
      if (stdin_fd >= 0) {
        Terminal terminal(stdin_fd);
        TerminalState terminal_state;
        const bool is_a_tty = terminal.IsATerminal();

        if (is_a_tty) {
          terminal_state.Save(stdin_fd, false);
          terminal.SetCanonical(false);
          terminal.SetEcho(true);
        }

        ScriptInterpreterPython::Locker locker(
            m_python, ScriptInterpreterPython::Locker::AcquireLock |
                          ScriptInterpreterPython::Locker::InitSession |
                          ScriptInterpreterPython::Locker::InitGlobals,
            ScriptInterpreterPython::Locker::FreeAcquiredLock |
                ScriptInterpreterPython::Locker::TearDownSession);

        // The following call drops into the embedded interpreter loop and
        // stays there until the user chooses to exit from the Python
        // interpreter. This embedded interpreter will, as any Python code that
        // performs I/O, unlock the GIL before a system call that can hang, and
        // lock it when the syscall has returned.

        // We need to surround the call to the embedded interpreter with calls
        // to PyGILState_Ensure and PyGILState_Release (using the Locker
        // above). This is because Python has a global lock which must be held
        // whenever we want to touch any Python objects. Otherwise, if the user
        // calls Python code, the interpreter state will be off, and things
        // could hang (it's happened before).

        StreamString run_string;
        run_string.Printf("run_python_interpreter (%s)",
                          m_python->GetDictionaryName());
        PyRun_SimpleString(run_string.GetData());

        if (is_a_tty)
          terminal_state.Restore();
      }
    }
    SetIsDone(true);
  }

  void Cancel() override {}

  bool Interrupt() override { return m_python->Interrupt(); }

  void GotEOF() override {}

protected:
  ScriptInterpreterPython *m_python;
};

void ScriptInterpreterPython::ExecuteInterpreterLoop() {
  static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
  Timer scoped_timer(func_cat, LLVM_PRETTY_FUNCTION);

  Debugger &debugger = GetCommandInterpreter().GetDebugger();

  // At the moment, the only time the debugger does not have an input file
  // handle is when this is called directly from Python, in which case it is
  // both dangerous and unnecessary (not to mention confusing) to try to embed
  // a running interpreter loop inside the already running Python interpreter
  // loop, so we won't do it.

  if (!debugger.GetInputFile()->GetFile().IsValid())
    return;

  IOHandlerSP io_handler_sp(new IOHandlerPythonInterpreter(debugger, this));
  if (io_handler_sp) {
    debugger.PushIOHandler(io_handler_sp);
  }
}

bool ScriptInterpreterPython::Interrupt() {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SCRIPT));

  if (IsExecutingPython()) {
    PyThreadState *state = PyThreadState_GET();
    if (!state)
      state = GetThreadState();
    if (state) {
      long tid = state->thread_id;
      PyThreadState_Swap(state);
      int num_threads = PyThreadState_SetAsyncExc(tid, PyExc_KeyboardInterrupt);
      if (log)
        log->Printf("ScriptInterpreterPython::Interrupt() sending "
                    "PyExc_KeyboardInterrupt (tid = %li, num_threads = %i)...",
                    tid, num_threads);
      return true;
    }
  }
  if (log)
    log->Printf("ScriptInterpreterPython::Interrupt() python code not running, "
                "can't interrupt");
  return false;
}
bool ScriptInterpreterPython::ExecuteOneLineWithReturn(
    llvm::StringRef in_string, ScriptInterpreter::ScriptReturnType return_type,
    void *ret_value, const ExecuteScriptOptions &options) {

  Locker locker(this, ScriptInterpreterPython::Locker::AcquireLock |
                          ScriptInterpreterPython::Locker::InitSession |
                          (options.GetSetLLDBGlobals()
                               ? ScriptInterpreterPython::Locker::InitGlobals
                               : 0) |
                          Locker::NoSTDIN,
                ScriptInterpreterPython::Locker::FreeAcquiredLock |
                    ScriptInterpreterPython::Locker::TearDownSession);

  PythonObject py_return;
  PythonObject &main_module = GetMainModule();
  PythonDictionary globals(PyRefType::Borrowed,
                           PyModule_GetDict(main_module.get()));
  PythonObject py_error;
  bool ret_success = false;
  int success;

  PythonDictionary locals = GetSessionDictionary();

  if (!locals.IsValid()) {
    locals.Reset(
        PyRefType::Owned,
        PyObject_GetAttrString(globals.get(), m_dictionary_name.c_str()));
  }

  if (!locals.IsValid())
    locals = globals;

  py_error.Reset(PyRefType::Borrowed, PyErr_Occurred());
  if (py_error.IsValid())
    PyErr_Clear();

  std::string as_string = in_string.str();
  { // scope for PythonInputReaderManager
    // PythonInputReaderManager py_input(options.GetEnableIO() ? this : NULL);
    py_return.Reset(PyRefType::Owned,
                    PyRun_String(as_string.c_str(), Py_eval_input,
                                 globals.get(), locals.get()));
    if (!py_return.IsValid()) {
      py_error.Reset(PyRefType::Borrowed, PyErr_Occurred());
      if (py_error.IsValid())
        PyErr_Clear();

      py_return.Reset(PyRefType::Owned,
                      PyRun_String(as_string.c_str(), Py_single_input,
                                   globals.get(), locals.get()));
    }
  }

  if (py_return.IsValid()) {
    switch (return_type) {
    case eScriptReturnTypeCharPtr: // "char *"
    {
      const char format[3] = "s#";
      success = PyArg_Parse(py_return.get(), format, (char **)ret_value);
      break;
    }
    case eScriptReturnTypeCharStrOrNone: // char* or NULL if py_return ==
                                         // Py_None
    {
      const char format[3] = "z";
      success = PyArg_Parse(py_return.get(), format, (char **)ret_value);
      break;
    }
    case eScriptReturnTypeBool: {
      const char format[2] = "b";
      success = PyArg_Parse(py_return.get(), format, (bool *)ret_value);
      break;
    }
    case eScriptReturnTypeShortInt: {
      const char format[2] = "h";
      success = PyArg_Parse(py_return.get(), format, (short *)ret_value);
      break;
    }
    case eScriptReturnTypeShortIntUnsigned: {
      const char format[2] = "H";
      success =
          PyArg_Parse(py_return.get(), format, (unsigned short *)ret_value);
      break;
    }
    case eScriptReturnTypeInt: {
      const char format[2] = "i";
      success = PyArg_Parse(py_return.get(), format, (int *)ret_value);
      break;
    }
    case eScriptReturnTypeIntUnsigned: {
      const char format[2] = "I";
      success = PyArg_Parse(py_return.get(), format, (unsigned int *)ret_value);
      break;
    }
    case eScriptReturnTypeLongInt: {
      const char format[2] = "l";
      success = PyArg_Parse(py_return.get(), format, (long *)ret_value);
      break;
    }
    case eScriptReturnTypeLongIntUnsigned: {
      const char format[2] = "k";
      success =
          PyArg_Parse(py_return.get(), format, (unsigned long *)ret_value);
      break;
    }
    case eScriptReturnTypeLongLong: {
      const char format[2] = "L";
      success = PyArg_Parse(py_return.get(), format, (long long *)ret_value);
      break;
    }
    case eScriptReturnTypeLongLongUnsigned: {
      const char format[2] = "K";
      success =
          PyArg_Parse(py_return.get(), format, (unsigned long long *)ret_value);
      break;
    }
    case eScriptReturnTypeFloat: {
      const char format[2] = "f";
      success = PyArg_Parse(py_return.get(), format, (float *)ret_value);
      break;
    }
    case eScriptReturnTypeDouble: {
      const char format[2] = "d";
      success = PyArg_Parse(py_return.get(), format, (double *)ret_value);
      break;
    }
    case eScriptReturnTypeChar: {
      const char format[2] = "c";
      success = PyArg_Parse(py_return.get(), format, (char *)ret_value);
      break;
    }
    case eScriptReturnTypeOpaqueObject: {
      success = true;
      PyObject *saved_value = py_return.get();
      Py_XINCREF(saved_value);
      *((PyObject **)ret_value) = saved_value;
      break;
    }
    }

    ret_success = success;
  }

  py_error.Reset(PyRefType::Borrowed, PyErr_Occurred());
  if (py_error.IsValid()) {
    ret_success = false;
    if (options.GetMaskoutErrors()) {
      if (PyErr_GivenExceptionMatches(py_error.get(), PyExc_SyntaxError))
        PyErr_Print();
      PyErr_Clear();
    }
  }

  return ret_success;
}

Status ScriptInterpreterPython::ExecuteMultipleLines(
    const char *in_string, const ExecuteScriptOptions &options) {
  Status error;

  Locker locker(this, ScriptInterpreterPython::Locker::AcquireLock |
                          ScriptInterpreterPython::Locker::InitSession |
                          (options.GetSetLLDBGlobals()
                               ? ScriptInterpreterPython::Locker::InitGlobals
                               : 0) |
                          Locker::NoSTDIN,
                ScriptInterpreterPython::Locker::FreeAcquiredLock |
                    ScriptInterpreterPython::Locker::TearDownSession);

  PythonObject return_value;
  PythonObject &main_module = GetMainModule();
  PythonDictionary globals(PyRefType::Borrowed,
                           PyModule_GetDict(main_module.get()));
  PythonObject py_error;

  PythonDictionary locals = GetSessionDictionary();

  if (!locals.IsValid())
    locals.Reset(
        PyRefType::Owned,
        PyObject_GetAttrString(globals.get(), m_dictionary_name.c_str()));

  if (!locals.IsValid())
    locals = globals;

  py_error.Reset(PyRefType::Borrowed, PyErr_Occurred());
  if (py_error.IsValid())
    PyErr_Clear();

  if (in_string != nullptr) {
    PythonObject code_object;
    code_object.Reset(PyRefType::Owned,
                      Py_CompileString(in_string, "temp.py", Py_file_input));

    if (code_object.IsValid()) {
// In Python 2.x, PyEval_EvalCode takes a PyCodeObject, but in Python 3.x, it
// takes a PyObject.  They are convertible (hence the function
// PyCode_Check(PyObject*), so we have to do the cast for Python 2.x
#if PY_MAJOR_VERSION >= 3
      PyObject *py_code_obj = code_object.get();
#else
      PyCodeObject *py_code_obj =
          reinterpret_cast<PyCodeObject *>(code_object.get());
#endif
      return_value.Reset(
          PyRefType::Owned,
          PyEval_EvalCode(py_code_obj, globals.get(), locals.get()));
    }
  }

  PythonExceptionState exception_state(!options.GetMaskoutErrors());
  if (exception_state.IsError())
    error.SetErrorString(exception_state.Format().c_str());

  return error;
}

void ScriptInterpreterPython::CollectDataForBreakpointCommandCallback(
    std::vector<BreakpointOptions *> &bp_options_vec,
    CommandReturnObject &result) {
  m_active_io_handler = eIOHandlerBreakpoint;
  m_interpreter.GetPythonCommandsFromIOHandler("    ", *this, true,
                                               &bp_options_vec);
}

void ScriptInterpreterPython::CollectDataForWatchpointCommandCallback(
    WatchpointOptions *wp_options, CommandReturnObject &result) {
  m_active_io_handler = eIOHandlerWatchpoint;
  m_interpreter.GetPythonCommandsFromIOHandler("    ", *this, true, wp_options);
}

void ScriptInterpreterPython::SetBreakpointCommandCallbackFunction(
    BreakpointOptions *bp_options, const char *function_name) {
  // For now just cons up a oneliner that calls the provided function.
  std::string oneliner("return ");
  oneliner += function_name;
  oneliner += "(frame, bp_loc, internal_dict)";
  m_interpreter.GetScriptInterpreter()->SetBreakpointCommandCallback(
      bp_options, oneliner.c_str());
}

Status ScriptInterpreterPython::SetBreakpointCommandCallback(
    BreakpointOptions *bp_options,
    std::unique_ptr<BreakpointOptions::CommandData> &cmd_data_up) {
  Status error;
  error = GenerateBreakpointCommandCallbackData(cmd_data_up->user_source,
                                                cmd_data_up->script_source);
  if (error.Fail()) {
    return error;
  }
  auto baton_sp =
      std::make_shared<BreakpointOptions::CommandBaton>(std::move(cmd_data_up));
  bp_options->SetCallback(ScriptInterpreterPython::BreakpointCallbackFunction,
                          baton_sp);
  return error;
}

// Set a Python one-liner as the callback for the breakpoint.
Status ScriptInterpreterPython::SetBreakpointCommandCallback(
    BreakpointOptions *bp_options, const char *command_body_text) {
  auto data_up = llvm::make_unique<CommandDataPython>();

  // Split the command_body_text into lines, and pass that to
  // GenerateBreakpointCommandCallbackData.  That will wrap the body in an
  // auto-generated function, and return the function name in script_source.
  // That is what the callback will actually invoke.

  data_up->user_source.SplitIntoLines(command_body_text);
  Status error = GenerateBreakpointCommandCallbackData(data_up->user_source,
                                                       data_up->script_source);
  if (error.Success()) {
    auto baton_sp =
        std::make_shared<BreakpointOptions::CommandBaton>(std::move(data_up));
    bp_options->SetCallback(ScriptInterpreterPython::BreakpointCallbackFunction,
                            baton_sp);
    return error;
  } else
    return error;
}

// Set a Python one-liner as the callback for the watchpoint.
void ScriptInterpreterPython::SetWatchpointCommandCallback(
    WatchpointOptions *wp_options, const char *oneliner) {
  auto data_up = llvm::make_unique<WatchpointOptions::CommandData>();

  // It's necessary to set both user_source and script_source to the oneliner.
  // The former is used to generate callback description (as in watchpoint
  // command list) while the latter is used for Python to interpret during the
  // actual callback.

  data_up->user_source.AppendString(oneliner);
  data_up->script_source.assign(oneliner);

  if (GenerateWatchpointCommandCallbackData(data_up->user_source,
                                            data_up->script_source)) {
    auto baton_sp =
        std::make_shared<WatchpointOptions::CommandBaton>(std::move(data_up));
    wp_options->SetCallback(ScriptInterpreterPython::WatchpointCallbackFunction,
                            baton_sp);
  }

  return;
}

Status ScriptInterpreterPython::ExportFunctionDefinitionToInterpreter(
    StringList &function_def) {
  // Convert StringList to one long, newline delimited, const char *.
  std::string function_def_string(function_def.CopyList());

  Status error = ExecuteMultipleLines(
      function_def_string.c_str(),
      ScriptInterpreter::ExecuteScriptOptions().SetEnableIO(false));
  return error;
}

Status ScriptInterpreterPython::GenerateFunction(const char *signature,
                                                 const StringList &input) {
  Status error;
  int num_lines = input.GetSize();
  if (num_lines == 0) {
    error.SetErrorString("No input data.");
    return error;
  }

  if (!signature || *signature == 0) {
    error.SetErrorString("No output function name.");
    return error;
  }

  StreamString sstr;
  StringList auto_generated_function;
  auto_generated_function.AppendString(signature);
  auto_generated_function.AppendString(
      "     global_dict = globals()"); // Grab the global dictionary
  auto_generated_function.AppendString(
      "     new_keys = internal_dict.keys()"); // Make a list of keys in the
                                               // session dict
  auto_generated_function.AppendString(
      "     old_keys = global_dict.keys()"); // Save list of keys in global dict
  auto_generated_function.AppendString(
      "     global_dict.update (internal_dict)"); // Add the session dictionary
                                                  // to the
  // global dictionary.

  // Wrap everything up inside the function, increasing the indentation.

  auto_generated_function.AppendString("     if True:");
  for (int i = 0; i < num_lines; ++i) {
    sstr.Clear();
    sstr.Printf("       %s", input.GetStringAtIndex(i));
    auto_generated_function.AppendString(sstr.GetData());
  }
  auto_generated_function.AppendString(
      "     for key in new_keys:"); // Iterate over all the keys from session
                                    // dict
  auto_generated_function.AppendString(
      "         internal_dict[key] = global_dict[key]"); // Update session dict
                                                         // values
  auto_generated_function.AppendString(
      "         if key not in old_keys:"); // If key was not originally in
                                           // global dict
  auto_generated_function.AppendString(
      "             del global_dict[key]"); //  ...then remove key/value from
                                            //  global dict

  // Verify that the results are valid Python.

  error = ExportFunctionDefinitionToInterpreter(auto_generated_function);

  return error;
}

bool ScriptInterpreterPython::GenerateTypeScriptFunction(
    StringList &user_input, std::string &output, const void *name_token) {
  static uint32_t num_created_functions = 0;
  user_input.RemoveBlankLines();
  StreamString sstr;

  // Check to see if we have any data; if not, just return.
  if (user_input.GetSize() == 0)
    return false;

  // Take what the user wrote, wrap it all up inside one big auto-generated
  // Python function, passing in the ValueObject as parameter to the function.

  std::string auto_generated_function_name(
      GenerateUniqueName("lldb_autogen_python_type_print_func",
                         num_created_functions, name_token));
  sstr.Printf("def %s (valobj, internal_dict):",
              auto_generated_function_name.c_str());

  if (!GenerateFunction(sstr.GetData(), user_input).Success())
    return false;

  // Store the name of the auto-generated function to be called.
  output.assign(auto_generated_function_name);
  return true;
}

bool ScriptInterpreterPython::GenerateScriptAliasFunction(
    StringList &user_input, std::string &output) {
  static uint32_t num_created_functions = 0;
  user_input.RemoveBlankLines();
  StreamString sstr;

  // Check to see if we have any data; if not, just return.
  if (user_input.GetSize() == 0)
    return false;

  std::string auto_generated_function_name(GenerateUniqueName(
      "lldb_autogen_python_cmd_alias_func", num_created_functions));

  sstr.Printf("def %s (debugger, args, result, internal_dict):",
              auto_generated_function_name.c_str());

  if (!GenerateFunction(sstr.GetData(), user_input).Success())
    return false;

  // Store the name of the auto-generated function to be called.
  output.assign(auto_generated_function_name);
  return true;
}

bool ScriptInterpreterPython::GenerateTypeSynthClass(StringList &user_input,
                                                     std::string &output,
                                                     const void *name_token) {
  static uint32_t num_created_classes = 0;
  user_input.RemoveBlankLines();
  int num_lines = user_input.GetSize();
  StreamString sstr;

  // Check to see if we have any data; if not, just return.
  if (user_input.GetSize() == 0)
    return false;

  // Wrap all user input into a Python class

  std::string auto_generated_class_name(GenerateUniqueName(
      "lldb_autogen_python_type_synth_class", num_created_classes, name_token));

  StringList auto_generated_class;

  // Create the function name & definition string.

  sstr.Printf("class %s:", auto_generated_class_name.c_str());
  auto_generated_class.AppendString(sstr.GetString());

  // Wrap everything up inside the class, increasing the indentation. we don't
  // need to play any fancy indentation tricks here because there is no
  // surrounding code whose indentation we need to honor
  for (int i = 0; i < num_lines; ++i) {
    sstr.Clear();
    sstr.Printf("     %s", user_input.GetStringAtIndex(i));
    auto_generated_class.AppendString(sstr.GetString());
  }

  // Verify that the results are valid Python. (even though the method is
  // ExportFunctionDefinitionToInterpreter, a class will actually be exported)
  // (TODO: rename that method to ExportDefinitionToInterpreter)
  if (!ExportFunctionDefinitionToInterpreter(auto_generated_class).Success())
    return false;

  // Store the name of the auto-generated class

  output.assign(auto_generated_class_name);
  return true;
}

StructuredData::GenericSP ScriptInterpreterPython::CreateFrameRecognizer(
    const char *class_name) {
  if (class_name == nullptr || class_name[0] == '\0')
    return StructuredData::GenericSP();

  void *ret_val;

  {
    Locker py_lock(this, Locker::AcquireLock | Locker::NoSTDIN,
                   Locker::FreeLock);
    ret_val = LLDBSWIGPython_CreateFrameRecognizer(class_name,
                                                   m_dictionary_name.c_str());
  }

  return StructuredData::GenericSP(new StructuredPythonObject(ret_val));
}

lldb::ValueObjectListSP ScriptInterpreterPython::GetRecognizedArguments(
    const StructuredData::ObjectSP &os_plugin_object_sp,
    lldb::StackFrameSP frame_sp) {
  Locker py_lock(this, Locker::AcquireLock | Locker::NoSTDIN, Locker::FreeLock);

  if (!os_plugin_object_sp) return ValueObjectListSP();

  StructuredData::Generic *generic = os_plugin_object_sp->GetAsGeneric();
  if (!generic) return nullptr;

  PythonObject implementor(PyRefType::Borrowed,
                           (PyObject *)generic->GetValue());

  if (!implementor.IsAllocated()) return ValueObjectListSP();

  PythonObject py_return(PyRefType::Owned,
                         (PyObject *)LLDBSwigPython_GetRecognizedArguments(
                             implementor.get(), frame_sp));

  // if it fails, print the error but otherwise go on
  if (PyErr_Occurred()) {
    PyErr_Print();
    PyErr_Clear();
  }
  if (py_return.get()) {
    PythonList result_list(PyRefType::Borrowed, py_return.get());
    ValueObjectListSP result = ValueObjectListSP(new ValueObjectList());
    for (size_t i = 0; i < result_list.GetSize(); i++) {
      PyObject *item = result_list.GetItemAtIndex(i).get();
      lldb::SBValue *sb_value_ptr =
          (lldb::SBValue *)LLDBSWIGPython_CastPyObjectToSBValue(item);
      auto valobj_sp = LLDBSWIGPython_GetValueObjectSPFromSBValue(sb_value_ptr);
      if (valobj_sp) result->Append(valobj_sp);
    }
    return result;
  }
  return ValueObjectListSP();
}

StructuredData::GenericSP ScriptInterpreterPython::OSPlugin_CreatePluginObject(
    const char *class_name, lldb::ProcessSP process_sp) {
  if (class_name == nullptr || class_name[0] == '\0')
    return StructuredData::GenericSP();

  if (!process_sp)
    return StructuredData::GenericSP();

  void *ret_val;

  {
    Locker py_lock(this, Locker::AcquireLock | Locker::NoSTDIN,
                   Locker::FreeLock);
    ret_val = LLDBSWIGPythonCreateOSPlugin(
        class_name, m_dictionary_name.c_str(), process_sp);
  }

  return StructuredData::GenericSP(new StructuredPythonObject(ret_val));
}

StructuredData::DictionarySP ScriptInterpreterPython::OSPlugin_RegisterInfo(
    StructuredData::ObjectSP os_plugin_object_sp) {
  Locker py_lock(this, Locker::AcquireLock | Locker::NoSTDIN, Locker::FreeLock);

  static char callee_name[] = "get_register_info";

  if (!os_plugin_object_sp)
    return StructuredData::DictionarySP();

  StructuredData::Generic *generic = os_plugin_object_sp->GetAsGeneric();
  if (!generic)
    return nullptr;

  PythonObject implementor(PyRefType::Borrowed,
                           (PyObject *)generic->GetValue());

  if (!implementor.IsAllocated())
    return StructuredData::DictionarySP();

  PythonObject pmeth(PyRefType::Owned,
                     PyObject_GetAttrString(implementor.get(), callee_name));

  if (PyErr_Occurred())
    PyErr_Clear();

  if (!pmeth.IsAllocated())
    return StructuredData::DictionarySP();

  if (PyCallable_Check(pmeth.get()) == 0) {
    if (PyErr_Occurred())
      PyErr_Clear();

    return StructuredData::DictionarySP();
  }

  if (PyErr_Occurred())
    PyErr_Clear();

  // right now we know this function exists and is callable..
  PythonObject py_return(
      PyRefType::Owned,
      PyObject_CallMethod(implementor.get(), callee_name, nullptr));

  // if it fails, print the error but otherwise go on
  if (PyErr_Occurred()) {
    PyErr_Print();
    PyErr_Clear();
  }
  if (py_return.get()) {
    PythonDictionary result_dict(PyRefType::Borrowed, py_return.get());
    return result_dict.CreateStructuredDictionary();
  }
  return StructuredData::DictionarySP();
}

StructuredData::ArraySP ScriptInterpreterPython::OSPlugin_ThreadsInfo(
    StructuredData::ObjectSP os_plugin_object_sp) {
  Locker py_lock(this, Locker::AcquireLock | Locker::NoSTDIN, Locker::FreeLock);

  static char callee_name[] = "get_thread_info";

  if (!os_plugin_object_sp)
    return StructuredData::ArraySP();

  StructuredData::Generic *generic = os_plugin_object_sp->GetAsGeneric();
  if (!generic)
    return nullptr;

  PythonObject implementor(PyRefType::Borrowed,
                           (PyObject *)generic->GetValue());

  if (!implementor.IsAllocated())
    return StructuredData::ArraySP();

  PythonObject pmeth(PyRefType::Owned,
                     PyObject_GetAttrString(implementor.get(), callee_name));

  if (PyErr_Occurred())
    PyErr_Clear();

  if (!pmeth.IsAllocated())
    return StructuredData::ArraySP();

  if (PyCallable_Check(pmeth.get()) == 0) {
    if (PyErr_Occurred())
      PyErr_Clear();

    return StructuredData::ArraySP();
  }

  if (PyErr_Occurred())
    PyErr_Clear();

  // right now we know this function exists and is callable..
  PythonObject py_return(
      PyRefType::Owned,
      PyObject_CallMethod(implementor.get(), callee_name, nullptr));

  // if it fails, print the error but otherwise go on
  if (PyErr_Occurred()) {
    PyErr_Print();
    PyErr_Clear();
  }

  if (py_return.get()) {
    PythonList result_list(PyRefType::Borrowed, py_return.get());
    return result_list.CreateStructuredArray();
  }
  return StructuredData::ArraySP();
}

// GetPythonValueFormatString provides a system independent type safe way to
// convert a variable's type into a python value format. Python value formats
// are defined in terms of builtin C types and could change from system to as
// the underlying typedef for uint* types, size_t, off_t and other values
// change.

template <typename T> const char *GetPythonValueFormatString(T t);
template <> const char *GetPythonValueFormatString(char *) { return "s"; }
template <> const char *GetPythonValueFormatString(char) { return "b"; }
template <> const char *GetPythonValueFormatString(unsigned char) {
  return "B";
}
template <> const char *GetPythonValueFormatString(short) { return "h"; }
template <> const char *GetPythonValueFormatString(unsigned short) {
  return "H";
}
template <> const char *GetPythonValueFormatString(int) { return "i"; }
template <> const char *GetPythonValueFormatString(unsigned int) { return "I"; }
template <> const char *GetPythonValueFormatString(long) { return "l"; }
template <> const char *GetPythonValueFormatString(unsigned long) {
  return "k";
}
template <> const char *GetPythonValueFormatString(long long) { return "L"; }
template <> const char *GetPythonValueFormatString(unsigned long long) {
  return "K";
}
template <> const char *GetPythonValueFormatString(float t) { return "f"; }
template <> const char *GetPythonValueFormatString(double t) { return "d"; }

StructuredData::StringSP ScriptInterpreterPython::OSPlugin_RegisterContextData(
    StructuredData::ObjectSP os_plugin_object_sp, lldb::tid_t tid) {
  Locker py_lock(this, Locker::AcquireLock | Locker::NoSTDIN, Locker::FreeLock);

  static char callee_name[] = "get_register_data";
  static char *param_format =
      const_cast<char *>(GetPythonValueFormatString(tid));

  if (!os_plugin_object_sp)
    return StructuredData::StringSP();

  StructuredData::Generic *generic = os_plugin_object_sp->GetAsGeneric();
  if (!generic)
    return nullptr;
  PythonObject implementor(PyRefType::Borrowed,
                           (PyObject *)generic->GetValue());

  if (!implementor.IsAllocated())
    return StructuredData::StringSP();

  PythonObject pmeth(PyRefType::Owned,
                     PyObject_GetAttrString(implementor.get(), callee_name));

  if (PyErr_Occurred())
    PyErr_Clear();

  if (!pmeth.IsAllocated())
    return StructuredData::StringSP();

  if (PyCallable_Check(pmeth.get()) == 0) {
    if (PyErr_Occurred())
      PyErr_Clear();
    return StructuredData::StringSP();
  }

  if (PyErr_Occurred())
    PyErr_Clear();

  // right now we know this function exists and is callable..
  PythonObject py_return(
      PyRefType::Owned,
      PyObject_CallMethod(implementor.get(), callee_name, param_format, tid));

  // if it fails, print the error but otherwise go on
  if (PyErr_Occurred()) {
    PyErr_Print();
    PyErr_Clear();
  }

  if (py_return.get()) {
    PythonBytes result(PyRefType::Borrowed, py_return.get());
    return result.CreateStructuredString();
  }
  return StructuredData::StringSP();
}

StructuredData::DictionarySP ScriptInterpreterPython::OSPlugin_CreateThread(
    StructuredData::ObjectSP os_plugin_object_sp, lldb::tid_t tid,
    lldb::addr_t context) {
  Locker py_lock(this, Locker::AcquireLock | Locker::NoSTDIN, Locker::FreeLock);

  static char callee_name[] = "create_thread";
  std::string param_format;
  param_format += GetPythonValueFormatString(tid);
  param_format += GetPythonValueFormatString(context);

  if (!os_plugin_object_sp)
    return StructuredData::DictionarySP();

  StructuredData::Generic *generic = os_plugin_object_sp->GetAsGeneric();
  if (!generic)
    return nullptr;

  PythonObject implementor(PyRefType::Borrowed,
                           (PyObject *)generic->GetValue());

  if (!implementor.IsAllocated())
    return StructuredData::DictionarySP();

  PythonObject pmeth(PyRefType::Owned,
                     PyObject_GetAttrString(implementor.get(), callee_name));

  if (PyErr_Occurred())
    PyErr_Clear();

  if (!pmeth.IsAllocated())
    return StructuredData::DictionarySP();

  if (PyCallable_Check(pmeth.get()) == 0) {
    if (PyErr_Occurred())
      PyErr_Clear();
    return StructuredData::DictionarySP();
  }

  if (PyErr_Occurred())
    PyErr_Clear();

  // right now we know this function exists and is callable..
  PythonObject py_return(PyRefType::Owned,
                         PyObject_CallMethod(implementor.get(), callee_name,
                                             &param_format[0], tid, context));

  // if it fails, print the error but otherwise go on
  if (PyErr_Occurred()) {
    PyErr_Print();
    PyErr_Clear();
  }

  if (py_return.get()) {
    PythonDictionary result_dict(PyRefType::Borrowed, py_return.get());
    return result_dict.CreateStructuredDictionary();
  }
  return StructuredData::DictionarySP();
}

StructuredData::ObjectSP ScriptInterpreterPython::CreateScriptedThreadPlan(
    const char *class_name, lldb::ThreadPlanSP thread_plan_sp) {
  if (class_name == nullptr || class_name[0] == '\0')
    return StructuredData::ObjectSP();

  if (!thread_plan_sp.get())
    return StructuredData::ObjectSP();

  Debugger &debugger = thread_plan_sp->GetTarget().GetDebugger();
  ScriptInterpreter *script_interpreter =
      debugger.GetCommandInterpreter().GetScriptInterpreter();
  ScriptInterpreterPython *python_interpreter =
      static_cast<ScriptInterpreterPython *>(script_interpreter);

  if (!script_interpreter)
    return StructuredData::ObjectSP();

  void *ret_val;

  {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);

    ret_val = LLDBSwigPythonCreateScriptedThreadPlan(
        class_name, python_interpreter->m_dictionary_name.c_str(),
        thread_plan_sp);
  }

  return StructuredData::ObjectSP(new StructuredPythonObject(ret_val));
}

bool ScriptInterpreterPython::ScriptedThreadPlanExplainsStop(
    StructuredData::ObjectSP implementor_sp, Event *event, bool &script_error) {
  bool explains_stop = true;
  StructuredData::Generic *generic = nullptr;
  if (implementor_sp)
    generic = implementor_sp->GetAsGeneric();
  if (generic) {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    explains_stop = LLDBSWIGPythonCallThreadPlan(
        generic->GetValue(), "explains_stop", event, script_error);
    if (script_error)
      return true;
  }
  return explains_stop;
}

bool ScriptInterpreterPython::ScriptedThreadPlanShouldStop(
    StructuredData::ObjectSP implementor_sp, Event *event, bool &script_error) {
  bool should_stop = true;
  StructuredData::Generic *generic = nullptr;
  if (implementor_sp)
    generic = implementor_sp->GetAsGeneric();
  if (generic) {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    should_stop = LLDBSWIGPythonCallThreadPlan(
        generic->GetValue(), "should_stop", event, script_error);
    if (script_error)
      return true;
  }
  return should_stop;
}

bool ScriptInterpreterPython::ScriptedThreadPlanIsStale(
    StructuredData::ObjectSP implementor_sp, bool &script_error) {
  bool is_stale = true;
  StructuredData::Generic *generic = nullptr;
  if (implementor_sp)
    generic = implementor_sp->GetAsGeneric();
  if (generic) {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    is_stale = LLDBSWIGPythonCallThreadPlan(generic->GetValue(), "is_stale",
                                            nullptr, script_error);
    if (script_error)
      return true;
  }
  return is_stale;
}

lldb::StateType ScriptInterpreterPython::ScriptedThreadPlanGetRunState(
    StructuredData::ObjectSP implementor_sp, bool &script_error) {
  bool should_step = false;
  StructuredData::Generic *generic = nullptr;
  if (implementor_sp)
    generic = implementor_sp->GetAsGeneric();
  if (generic) {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    should_step = LLDBSWIGPythonCallThreadPlan(
        generic->GetValue(), "should_step", NULL, script_error);
    if (script_error)
      should_step = true;
  }
  if (should_step)
    return lldb::eStateStepping;
  else
    return lldb::eStateRunning;
}

StructuredData::GenericSP
ScriptInterpreterPython::CreateScriptedBreakpointResolver(
    const char *class_name,
    StructuredDataImpl *args_data,
    lldb::BreakpointSP &bkpt_sp) {

  if (class_name == nullptr || class_name[0] == '\0')
    return StructuredData::GenericSP();

  if (!bkpt_sp.get())
    return StructuredData::GenericSP();

  Debugger &debugger = bkpt_sp->GetTarget().GetDebugger();
  ScriptInterpreter *script_interpreter =
      debugger.GetCommandInterpreter().GetScriptInterpreter();
  ScriptInterpreterPython *python_interpreter =
      static_cast<ScriptInterpreterPython *>(script_interpreter);

  if (!script_interpreter)
    return StructuredData::GenericSP();

  void *ret_val;

  {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);

    ret_val = LLDBSwigPythonCreateScriptedBreakpointResolver(
        class_name, python_interpreter->m_dictionary_name.c_str(), args_data,
        bkpt_sp);
  }

  return StructuredData::GenericSP(new StructuredPythonObject(ret_val));
}

bool
ScriptInterpreterPython::ScriptedBreakpointResolverSearchCallback(
    StructuredData::GenericSP implementor_sp,
    SymbolContext *sym_ctx) {
  bool should_continue = false;

  if (implementor_sp) {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    should_continue = LLDBSwigPythonCallBreakpointResolver(
        implementor_sp->GetValue(), "__callback__", sym_ctx);
    if (PyErr_Occurred()) {
      PyErr_Print();
      PyErr_Clear();
    }
  }
  return should_continue;
}

lldb::SearchDepth
ScriptInterpreterPython::ScriptedBreakpointResolverSearchDepth(
    StructuredData::GenericSP implementor_sp) {
  int depth_as_int = lldb::eSearchDepthModule;
  if (implementor_sp) {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    depth_as_int = LLDBSwigPythonCallBreakpointResolver(
        implementor_sp->GetValue(), "__get_depth__", nullptr);
    if (PyErr_Occurred()) {
      PyErr_Print();
      PyErr_Clear();
    }
  }
  if (depth_as_int == lldb::eSearchDepthInvalid)
    return lldb::eSearchDepthModule;

  if (depth_as_int <= lldb::kLastSearchDepthKind)
    return (lldb::SearchDepth) depth_as_int;
  else
    return lldb::eSearchDepthModule;
}

StructuredData::ObjectSP
ScriptInterpreterPython::LoadPluginModule(const FileSpec &file_spec,
                                          lldb_private::Status &error) {
  if (!FileSystem::Instance().Exists(file_spec)) {
    error.SetErrorString("no such file");
    return StructuredData::ObjectSP();
  }

  StructuredData::ObjectSP module_sp;

  if (LoadScriptingModule(file_spec.GetPath().c_str(), true, true, error,
                          &module_sp))
    return module_sp;

  return StructuredData::ObjectSP();
}

StructuredData::DictionarySP ScriptInterpreterPython::GetDynamicSettings(
    StructuredData::ObjectSP plugin_module_sp, Target *target,
    const char *setting_name, lldb_private::Status &error) {
  if (!plugin_module_sp || !target || !setting_name || !setting_name[0])
    return StructuredData::DictionarySP();
  StructuredData::Generic *generic = plugin_module_sp->GetAsGeneric();
  if (!generic)
    return StructuredData::DictionarySP();

  PythonObject reply_pyobj;
  Locker py_lock(this,
                 Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
  TargetSP target_sp(target->shared_from_this());
  reply_pyobj.Reset(PyRefType::Owned,
                    (PyObject *)LLDBSWIGPython_GetDynamicSetting(
                        generic->GetValue(), setting_name, target_sp));

  PythonDictionary py_dict(PyRefType::Borrowed, reply_pyobj.get());
  return py_dict.CreateStructuredDictionary();
}

StructuredData::ObjectSP
ScriptInterpreterPython::CreateSyntheticScriptedProvider(
    const char *class_name, lldb::ValueObjectSP valobj) {
  if (class_name == nullptr || class_name[0] == '\0')
    return StructuredData::ObjectSP();

  if (!valobj.get())
    return StructuredData::ObjectSP();

  ExecutionContext exe_ctx(valobj->GetExecutionContextRef());
  Target *target = exe_ctx.GetTargetPtr();

  if (!target)
    return StructuredData::ObjectSP();

  Debugger &debugger = target->GetDebugger();
  ScriptInterpreter *script_interpreter =
      debugger.GetCommandInterpreter().GetScriptInterpreter();
  ScriptInterpreterPython *python_interpreter =
      (ScriptInterpreterPython *)script_interpreter;

  if (!script_interpreter)
    return StructuredData::ObjectSP();

  void *ret_val = nullptr;

  {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    ret_val = LLDBSwigPythonCreateSyntheticProvider(
        class_name, python_interpreter->m_dictionary_name.c_str(), valobj);
  }

  return StructuredData::ObjectSP(new StructuredPythonObject(ret_val));
}

StructuredData::GenericSP
ScriptInterpreterPython::CreateScriptCommandObject(const char *class_name) {
  DebuggerSP debugger_sp(
      GetCommandInterpreter().GetDebugger().shared_from_this());

  if (class_name == nullptr || class_name[0] == '\0')
    return StructuredData::GenericSP();

  if (!debugger_sp.get())
    return StructuredData::GenericSP();

  void *ret_val;

  {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    ret_val = LLDBSwigPythonCreateCommandObject(
        class_name, m_dictionary_name.c_str(), debugger_sp);
  }

  return StructuredData::GenericSP(new StructuredPythonObject(ret_val));
}

bool ScriptInterpreterPython::GenerateTypeScriptFunction(
    const char *oneliner, std::string &output, const void *name_token) {
  StringList input;
  input.SplitIntoLines(oneliner, strlen(oneliner));
  return GenerateTypeScriptFunction(input, output, name_token);
}

bool ScriptInterpreterPython::GenerateTypeSynthClass(const char *oneliner,
                                                     std::string &output,
                                                     const void *name_token) {
  StringList input;
  input.SplitIntoLines(oneliner, strlen(oneliner));
  return GenerateTypeSynthClass(input, output, name_token);
}

Status ScriptInterpreterPython::GenerateBreakpointCommandCallbackData(
    StringList &user_input, std::string &output) {
  static uint32_t num_created_functions = 0;
  user_input.RemoveBlankLines();
  StreamString sstr;
  Status error;
  if (user_input.GetSize() == 0) {
    error.SetErrorString("No input data.");
    return error;
  }

  std::string auto_generated_function_name(GenerateUniqueName(
      "lldb_autogen_python_bp_callback_func_", num_created_functions));
  sstr.Printf("def %s (frame, bp_loc, internal_dict):",
              auto_generated_function_name.c_str());

  error = GenerateFunction(sstr.GetData(), user_input);
  if (!error.Success())
    return error;

  // Store the name of the auto-generated function to be called.
  output.assign(auto_generated_function_name);
  return error;
}

bool ScriptInterpreterPython::GenerateWatchpointCommandCallbackData(
    StringList &user_input, std::string &output) {
  static uint32_t num_created_functions = 0;
  user_input.RemoveBlankLines();
  StreamString sstr;

  if (user_input.GetSize() == 0)
    return false;

  std::string auto_generated_function_name(GenerateUniqueName(
      "lldb_autogen_python_wp_callback_func_", num_created_functions));
  sstr.Printf("def %s (frame, wp, internal_dict):",
              auto_generated_function_name.c_str());

  if (!GenerateFunction(sstr.GetData(), user_input).Success())
    return false;

  // Store the name of the auto-generated function to be called.
  output.assign(auto_generated_function_name);
  return true;
}

bool ScriptInterpreterPython::GetScriptedSummary(
    const char *python_function_name, lldb::ValueObjectSP valobj,
    StructuredData::ObjectSP &callee_wrapper_sp,
    const TypeSummaryOptions &options, std::string &retval) {

  static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
  Timer scoped_timer(func_cat, LLVM_PRETTY_FUNCTION);

  if (!valobj.get()) {
    retval.assign("<no object>");
    return false;
  }

  void *old_callee = nullptr;
  StructuredData::Generic *generic = nullptr;
  if (callee_wrapper_sp) {
    generic = callee_wrapper_sp->GetAsGeneric();
    if (generic)
      old_callee = generic->GetValue();
  }
  void *new_callee = old_callee;

  bool ret_val;
  if (python_function_name && *python_function_name) {
    {
      Locker py_lock(this, Locker::AcquireLock | Locker::InitSession |
                               Locker::NoSTDIN);
      {
        TypeSummaryOptionsSP options_sp(new TypeSummaryOptions(options));

        static Timer::Category func_cat("LLDBSwigPythonCallTypeScript");
        Timer scoped_timer(func_cat, "LLDBSwigPythonCallTypeScript");
        ret_val = LLDBSwigPythonCallTypeScript(
            python_function_name, GetSessionDictionary().get(), valobj,
            &new_callee, options_sp, retval);
      }
    }
  } else {
    retval.assign("<no function name>");
    return false;
  }

  if (new_callee && old_callee != new_callee)
    callee_wrapper_sp = std::make_shared<StructuredPythonObject>(new_callee);

  return ret_val;
}

void ScriptInterpreterPython::Clear() {
  // Release any global variables that might have strong references to
  // LLDB objects when clearing the python script interpreter.
  Locker locker(this, ScriptInterpreterPython::Locker::AcquireLock,
                ScriptInterpreterPython::Locker::FreeAcquiredLock);

  // This may be called as part of Py_Finalize.  In that case the modules are
  // destroyed in random order and we can't guarantee that we can access these.
  if (Py_IsInitialized())
    PyRun_SimpleString("lldb.debugger = None; lldb.target = None; lldb.process "
                       "= None; lldb.thread = None; lldb.frame = None");
}

bool ScriptInterpreterPython::BreakpointCallbackFunction(
    void *baton, StoppointCallbackContext *context, user_id_t break_id,
    user_id_t break_loc_id) {
  CommandDataPython *bp_option_data = (CommandDataPython *)baton;
  const char *python_function_name = bp_option_data->script_source.c_str();

  if (!context)
    return true;

  ExecutionContext exe_ctx(context->exe_ctx_ref);
  Target *target = exe_ctx.GetTargetPtr();

  if (!target)
    return true;

  Debugger &debugger = target->GetDebugger();
  ScriptInterpreter *script_interpreter =
      debugger.GetCommandInterpreter().GetScriptInterpreter();
  ScriptInterpreterPython *python_interpreter =
      (ScriptInterpreterPython *)script_interpreter;

  if (!script_interpreter)
    return true;

  if (python_function_name && python_function_name[0]) {
    const StackFrameSP stop_frame_sp(exe_ctx.GetFrameSP());
    BreakpointSP breakpoint_sp = target->GetBreakpointByID(break_id);
    if (breakpoint_sp) {
      const BreakpointLocationSP bp_loc_sp(
          breakpoint_sp->FindLocationByID(break_loc_id));

      if (stop_frame_sp && bp_loc_sp) {
        bool ret_val = true;
        {
          Locker py_lock(python_interpreter, Locker::AcquireLock |
                                                 Locker::InitSession |
                                                 Locker::NoSTDIN);
          ret_val = LLDBSwigPythonBreakpointCallbackFunction(
              python_function_name,
              python_interpreter->m_dictionary_name.c_str(), stop_frame_sp,
              bp_loc_sp);
        }
        return ret_val;
      }
    }
  }
  // We currently always true so we stop in case anything goes wrong when
  // trying to call the script function
  return true;
}

bool ScriptInterpreterPython::WatchpointCallbackFunction(
    void *baton, StoppointCallbackContext *context, user_id_t watch_id) {
  WatchpointOptions::CommandData *wp_option_data =
      (WatchpointOptions::CommandData *)baton;
  const char *python_function_name = wp_option_data->script_source.c_str();

  if (!context)
    return true;

  ExecutionContext exe_ctx(context->exe_ctx_ref);
  Target *target = exe_ctx.GetTargetPtr();

  if (!target)
    return true;

  Debugger &debugger = target->GetDebugger();
  ScriptInterpreter *script_interpreter =
      debugger.GetCommandInterpreter().GetScriptInterpreter();
  ScriptInterpreterPython *python_interpreter =
      (ScriptInterpreterPython *)script_interpreter;

  if (!script_interpreter)
    return true;

  if (python_function_name && python_function_name[0]) {
    const StackFrameSP stop_frame_sp(exe_ctx.GetFrameSP());
    WatchpointSP wp_sp = target->GetWatchpointList().FindByID(watch_id);
    if (wp_sp) {
      if (stop_frame_sp && wp_sp) {
        bool ret_val = true;
        {
          Locker py_lock(python_interpreter, Locker::AcquireLock |
                                                 Locker::InitSession |
                                                 Locker::NoSTDIN);
          ret_val = LLDBSwigPythonWatchpointCallbackFunction(
              python_function_name,
              python_interpreter->m_dictionary_name.c_str(), stop_frame_sp,
              wp_sp);
        }
        return ret_val;
      }
    }
  }
  // We currently always true so we stop in case anything goes wrong when
  // trying to call the script function
  return true;
}

size_t ScriptInterpreterPython::CalculateNumChildren(
    const StructuredData::ObjectSP &implementor_sp, uint32_t max) {
  if (!implementor_sp)
    return 0;
  StructuredData::Generic *generic = implementor_sp->GetAsGeneric();
  if (!generic)
    return 0;
  void *implementor = generic->GetValue();
  if (!implementor)
    return 0;

  size_t ret_val = 0;

  {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    ret_val = LLDBSwigPython_CalculateNumChildren(implementor, max);
  }

  return ret_val;
}

lldb::ValueObjectSP ScriptInterpreterPython::GetChildAtIndex(
    const StructuredData::ObjectSP &implementor_sp, uint32_t idx) {
  if (!implementor_sp)
    return lldb::ValueObjectSP();

  StructuredData::Generic *generic = implementor_sp->GetAsGeneric();
  if (!generic)
    return lldb::ValueObjectSP();
  void *implementor = generic->GetValue();
  if (!implementor)
    return lldb::ValueObjectSP();


  lldb::ValueObjectSP ret_val;
  {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    void *child_ptr = LLDBSwigPython_GetChildAtIndex(implementor, idx);
    if (child_ptr != nullptr && child_ptr != Py_None) {
      lldb::SBValue *sb_value_ptr =
          (lldb::SBValue *)LLDBSWIGPython_CastPyObjectToSBValue(child_ptr);
      if (sb_value_ptr == nullptr)
        Py_XDECREF(child_ptr);
      else
        ret_val = LLDBSWIGPython_GetValueObjectSPFromSBValue(sb_value_ptr);
    } else {
      Py_XDECREF(child_ptr);
    }
  }

  return ret_val;
}

int ScriptInterpreterPython::GetIndexOfChildWithName(
    const StructuredData::ObjectSP &implementor_sp, const char *child_name) {
  if (!implementor_sp)
    return UINT32_MAX;

  StructuredData::Generic *generic = implementor_sp->GetAsGeneric();
  if (!generic)
    return UINT32_MAX;
  void *implementor = generic->GetValue();
  if (!implementor)
    return UINT32_MAX;

  int ret_val = UINT32_MAX;

  {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    ret_val = LLDBSwigPython_GetIndexOfChildWithName(implementor, child_name);
  }

  return ret_val;
}

bool ScriptInterpreterPython::UpdateSynthProviderInstance(
    const StructuredData::ObjectSP &implementor_sp) {
  bool ret_val = false;

  if (!implementor_sp)
    return ret_val;

  StructuredData::Generic *generic = implementor_sp->GetAsGeneric();
  if (!generic)
    return ret_val;
  void *implementor = generic->GetValue();
  if (!implementor)
    return ret_val;

  {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    ret_val = LLDBSwigPython_UpdateSynthProviderInstance(implementor);
  }

  return ret_val;
}

bool ScriptInterpreterPython::MightHaveChildrenSynthProviderInstance(
    const StructuredData::ObjectSP &implementor_sp) {
  bool ret_val = false;

  if (!implementor_sp)
    return ret_val;

  StructuredData::Generic *generic = implementor_sp->GetAsGeneric();
  if (!generic)
    return ret_val;
  void *implementor = generic->GetValue();
  if (!implementor)
    return ret_val;


  {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    ret_val =
        LLDBSwigPython_MightHaveChildrenSynthProviderInstance(implementor);
  }

  return ret_val;
}

lldb::ValueObjectSP ScriptInterpreterPython::GetSyntheticValue(
    const StructuredData::ObjectSP &implementor_sp) {
  lldb::ValueObjectSP ret_val(nullptr);

  if (!implementor_sp)
    return ret_val;

  StructuredData::Generic *generic = implementor_sp->GetAsGeneric();
  if (!generic)
    return ret_val;
  void *implementor = generic->GetValue();
  if (!implementor)
    return ret_val;

  {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    void *child_ptr = LLDBSwigPython_GetValueSynthProviderInstance(implementor);
    if (child_ptr != nullptr && child_ptr != Py_None) {
      lldb::SBValue *sb_value_ptr =
          (lldb::SBValue *)LLDBSWIGPython_CastPyObjectToSBValue(child_ptr);
      if (sb_value_ptr == nullptr)
        Py_XDECREF(child_ptr);
      else
        ret_val = LLDBSWIGPython_GetValueObjectSPFromSBValue(sb_value_ptr);
    } else {
      Py_XDECREF(child_ptr);
    }
  }

  return ret_val;
}

ConstString ScriptInterpreterPython::GetSyntheticTypeName(
    const StructuredData::ObjectSP &implementor_sp) {
  Locker py_lock(this,
                 Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);

  static char callee_name[] = "get_type_name";

  ConstString ret_val;
  bool got_string = false;
  std::string buffer;

  if (!implementor_sp)
    return ret_val;

  StructuredData::Generic *generic = implementor_sp->GetAsGeneric();
  if (!generic)
    return ret_val;
  PythonObject implementor(PyRefType::Borrowed,
                           (PyObject *)generic->GetValue());
  if (!implementor.IsAllocated())
    return ret_val;

  PythonObject pmeth(PyRefType::Owned,
                     PyObject_GetAttrString(implementor.get(), callee_name));

  if (PyErr_Occurred())
    PyErr_Clear();

  if (!pmeth.IsAllocated())
    return ret_val;

  if (PyCallable_Check(pmeth.get()) == 0) {
    if (PyErr_Occurred())
      PyErr_Clear();
    return ret_val;
  }

  if (PyErr_Occurred())
    PyErr_Clear();

  // right now we know this function exists and is callable..
  PythonObject py_return(
      PyRefType::Owned,
      PyObject_CallMethod(implementor.get(), callee_name, nullptr));

  // if it fails, print the error but otherwise go on
  if (PyErr_Occurred()) {
    PyErr_Print();
    PyErr_Clear();
  }

  if (py_return.IsAllocated() && PythonString::Check(py_return.get())) {
    PythonString py_string(PyRefType::Borrowed, py_return.get());
    llvm::StringRef return_data(py_string.GetString());
    if (!return_data.empty()) {
      buffer.assign(return_data.data(), return_data.size());
      got_string = true;
    }
  }

  if (got_string)
    ret_val.SetCStringWithLength(buffer.c_str(), buffer.size());

  return ret_val;
}

bool ScriptInterpreterPython::RunScriptFormatKeyword(const char *impl_function,
                                                     Process *process,
                                                     std::string &output,
                                                     Status &error) {
  bool ret_val;
  if (!process) {
    error.SetErrorString("no process");
    return false;
  }
  if (!impl_function || !impl_function[0]) {
    error.SetErrorString("no function to execute");
    return false;
  }

  {
    ProcessSP process_sp(process->shared_from_this());
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    ret_val = LLDBSWIGPythonRunScriptKeywordProcess(
        impl_function, m_dictionary_name.c_str(), process_sp, output);
    if (!ret_val)
      error.SetErrorString("python script evaluation failed");
  }
  return ret_val;
}

bool ScriptInterpreterPython::RunScriptFormatKeyword(const char *impl_function,
                                                     Thread *thread,
                                                     std::string &output,
                                                     Status &error) {
  bool ret_val;
  if (!thread) {
    error.SetErrorString("no thread");
    return false;
  }
  if (!impl_function || !impl_function[0]) {
    error.SetErrorString("no function to execute");
    return false;
  }

  {
    ThreadSP thread_sp(thread->shared_from_this());
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    ret_val = LLDBSWIGPythonRunScriptKeywordThread(
        impl_function, m_dictionary_name.c_str(), thread_sp, output);
    if (!ret_val)
      error.SetErrorString("python script evaluation failed");
  }
  return ret_val;
}

bool ScriptInterpreterPython::RunScriptFormatKeyword(const char *impl_function,
                                                     Target *target,
                                                     std::string &output,
                                                     Status &error) {
  bool ret_val;
  if (!target) {
    error.SetErrorString("no thread");
    return false;
  }
  if (!impl_function || !impl_function[0]) {
    error.SetErrorString("no function to execute");
    return false;
  }

  {
    TargetSP target_sp(target->shared_from_this());
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    ret_val = LLDBSWIGPythonRunScriptKeywordTarget(
        impl_function, m_dictionary_name.c_str(), target_sp, output);
    if (!ret_val)
      error.SetErrorString("python script evaluation failed");
  }
  return ret_val;
}

bool ScriptInterpreterPython::RunScriptFormatKeyword(const char *impl_function,
                                                     StackFrame *frame,
                                                     std::string &output,
                                                     Status &error) {
  bool ret_val;
  if (!frame) {
    error.SetErrorString("no frame");
    return false;
  }
  if (!impl_function || !impl_function[0]) {
    error.SetErrorString("no function to execute");
    return false;
  }

  {
    StackFrameSP frame_sp(frame->shared_from_this());
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    ret_val = LLDBSWIGPythonRunScriptKeywordFrame(
        impl_function, m_dictionary_name.c_str(), frame_sp, output);
    if (!ret_val)
      error.SetErrorString("python script evaluation failed");
  }
  return ret_val;
}

bool ScriptInterpreterPython::RunScriptFormatKeyword(const char *impl_function,
                                                     ValueObject *value,
                                                     std::string &output,
                                                     Status &error) {
  bool ret_val;
  if (!value) {
    error.SetErrorString("no value");
    return false;
  }
  if (!impl_function || !impl_function[0]) {
    error.SetErrorString("no function to execute");
    return false;
  }

  {
    ValueObjectSP value_sp(value->GetSP());
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
    ret_val = LLDBSWIGPythonRunScriptKeywordValue(
        impl_function, m_dictionary_name.c_str(), value_sp, output);
    if (!ret_val)
      error.SetErrorString("python script evaluation failed");
  }
  return ret_val;
}

uint64_t replace_all(std::string &str, const std::string &oldStr,
                     const std::string &newStr) {
  size_t pos = 0;
  uint64_t matches = 0;
  while ((pos = str.find(oldStr, pos)) != std::string::npos) {
    matches++;
    str.replace(pos, oldStr.length(), newStr);
    pos += newStr.length();
  }
  return matches;
}

bool ScriptInterpreterPython::LoadScriptingModule(
    const char *pathname, bool can_reload, bool init_session,
    lldb_private::Status &error, StructuredData::ObjectSP *module_sp) {
  if (!pathname || !pathname[0]) {
    error.SetErrorString("invalid pathname");
    return false;
  }

  lldb::DebuggerSP debugger_sp = m_interpreter.GetDebugger().shared_from_this();

  {
    FileSpec target_file(pathname);
    FileSystem::Instance().Resolve(target_file);
    std::string basename(target_file.GetFilename().GetCString());

    StreamString command_stream;

    // Before executing Python code, lock the GIL.
    Locker py_lock(this, Locker::AcquireLock |
                             (init_session ? Locker::InitSession : 0) |
                             Locker::NoSTDIN,
                   Locker::FreeAcquiredLock |
                       (init_session ? Locker::TearDownSession : 0));
    namespace fs = llvm::sys::fs;
    fs::file_status st;
    std::error_code ec = status(target_file.GetPath(), st);

    if (ec || st.type() == fs::file_type::status_error ||
        st.type() == fs::file_type::type_unknown ||
        st.type() == fs::file_type::file_not_found) {
      // if not a valid file of any sort, check if it might be a filename still
      // dot can't be used but / and \ can, and if either is found, reject
      if (strchr(pathname, '\\') || strchr(pathname, '/')) {
        error.SetErrorString("invalid pathname");
        return false;
      }
      basename = pathname; // not a filename, probably a package of some sort,
                           // let it go through
    } else if (is_directory(st) || is_regular_file(st)) {
      if (target_file.GetDirectory().IsEmpty()) {
        error.SetErrorString("invalid directory name");
        return false;
      }

      std::string directory = target_file.GetDirectory().GetCString();
      replace_all(directory, "\\", "\\\\");
      replace_all(directory, "'", "\\'");

      // now make sure that Python has "directory" in the search path
      StreamString command_stream;
      command_stream.Printf("if not (sys.path.__contains__('%s')):\n    "
                            "sys.path.insert(1,'%s');\n\n",
                            directory.c_str(), directory.c_str());
      bool syspath_retval =
          ExecuteMultipleLines(command_stream.GetData(),
                               ScriptInterpreter::ExecuteScriptOptions()
                                   .SetEnableIO(false)
                                   .SetSetLLDBGlobals(false))
              .Success();
      if (!syspath_retval) {
        error.SetErrorString("Python sys.path handling failed");
        return false;
      }

      // strip .py or .pyc extension
      ConstString extension = target_file.GetFileNameExtension();
      if (extension) {
        if (llvm::StringRef(extension.GetCString()) == ".py")
          basename.resize(basename.length() - 3);
        else if (llvm::StringRef(extension.GetCString()) == ".pyc")
          basename.resize(basename.length() - 4);
      }
    } else {
      error.SetErrorString("no known way to import this module specification");
      return false;
    }

    // check if the module is already import-ed
    command_stream.Clear();
    command_stream.Printf("sys.modules.__contains__('%s')", basename.c_str());
    bool does_contain = false;
    // this call will succeed if the module was ever imported in any Debugger
    // in the lifetime of the process in which this LLDB framework is living
    bool was_imported_globally =
        (ExecuteOneLineWithReturn(
             command_stream.GetData(),
             ScriptInterpreterPython::eScriptReturnTypeBool, &does_contain,
             ScriptInterpreter::ExecuteScriptOptions()
                 .SetEnableIO(false)
                 .SetSetLLDBGlobals(false)) &&
         does_contain);
    // this call will fail if the module was not imported in this Debugger
    // before
    command_stream.Clear();
    command_stream.Printf("sys.getrefcount(%s)", basename.c_str());
    bool was_imported_locally = GetSessionDictionary()
                                    .GetItemForKey(PythonString(basename))
                                    .IsAllocated();

    bool was_imported = (was_imported_globally || was_imported_locally);

    if (was_imported && !can_reload) {
      error.SetErrorString("module already imported");
      return false;
    }

    // now actually do the import
    command_stream.Clear();

    if (was_imported) {
      if (!was_imported_locally)
        command_stream.Printf("import %s ; reload_module(%s)", basename.c_str(),
                              basename.c_str());
      else
        command_stream.Printf("reload_module(%s)", basename.c_str());
    } else
      command_stream.Printf("import %s", basename.c_str());

    error = ExecuteMultipleLines(command_stream.GetData(),
                                 ScriptInterpreter::ExecuteScriptOptions()
                                     .SetEnableIO(false)
                                     .SetSetLLDBGlobals(false));
    if (error.Fail())
      return false;

    // if we are here, everything worked
    // call __lldb_init_module(debugger,dict)
    if (!LLDBSwigPythonCallModuleInit(basename.c_str(),
                                      m_dictionary_name.c_str(), debugger_sp)) {
      error.SetErrorString("calling __lldb_init_module failed");
      return false;
    }

    if (module_sp) {
      // everything went just great, now set the module object
      command_stream.Clear();
      command_stream.Printf("%s", basename.c_str());
      void *module_pyobj = nullptr;
      if (ExecuteOneLineWithReturn(
              command_stream.GetData(),
              ScriptInterpreter::eScriptReturnTypeOpaqueObject,
              &module_pyobj) &&
          module_pyobj)
        *module_sp = std::make_shared<StructuredPythonObject>(module_pyobj);
    }

    return true;
  }
}

bool ScriptInterpreterPython::IsReservedWord(const char *word) {
  if (!word || !word[0])
    return false;

  llvm::StringRef word_sr(word);

  // filter out a few characters that would just confuse us and that are
  // clearly not keyword material anyway
  if (word_sr.find_first_of("'\"") != llvm::StringRef::npos)
    return false;

  StreamString command_stream;
  command_stream.Printf("keyword.iskeyword('%s')", word);
  bool result;
  ExecuteScriptOptions options;
  options.SetEnableIO(false);
  options.SetMaskoutErrors(true);
  options.SetSetLLDBGlobals(false);
  if (ExecuteOneLineWithReturn(command_stream.GetData(),
                               ScriptInterpreter::eScriptReturnTypeBool,
                               &result, options))
    return result;
  return false;
}

ScriptInterpreterPython::SynchronicityHandler::SynchronicityHandler(
    lldb::DebuggerSP debugger_sp, ScriptedCommandSynchronicity synchro)
    : m_debugger_sp(debugger_sp), m_synch_wanted(synchro),
      m_old_asynch(debugger_sp->GetAsyncExecution()) {
  if (m_synch_wanted == eScriptedCommandSynchronicitySynchronous)
    m_debugger_sp->SetAsyncExecution(false);
  else if (m_synch_wanted == eScriptedCommandSynchronicityAsynchronous)
    m_debugger_sp->SetAsyncExecution(true);
}

ScriptInterpreterPython::SynchronicityHandler::~SynchronicityHandler() {
  if (m_synch_wanted != eScriptedCommandSynchronicityCurrentValue)
    m_debugger_sp->SetAsyncExecution(m_old_asynch);
}

bool ScriptInterpreterPython::RunScriptBasedCommand(
    const char *impl_function, llvm::StringRef args,
    ScriptedCommandSynchronicity synchronicity,
    lldb_private::CommandReturnObject &cmd_retobj, Status &error,
    const lldb_private::ExecutionContext &exe_ctx) {
  if (!impl_function) {
    error.SetErrorString("no function to execute");
    return false;
  }

  lldb::DebuggerSP debugger_sp = m_interpreter.GetDebugger().shared_from_this();
  lldb::ExecutionContextRefSP exe_ctx_ref_sp(new ExecutionContextRef(exe_ctx));

  if (!debugger_sp.get()) {
    error.SetErrorString("invalid Debugger pointer");
    return false;
  }

  bool ret_val = false;

  std::string err_msg;

  {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession |
                       (cmd_retobj.GetInteractive() ? 0 : Locker::NoSTDIN),
                   Locker::FreeLock | Locker::TearDownSession);

    SynchronicityHandler synch_handler(debugger_sp, synchronicity);

    std::string args_str = args.str();
    ret_val = LLDBSwigPythonCallCommand(
        impl_function, m_dictionary_name.c_str(), debugger_sp, args_str.c_str(),
        cmd_retobj, exe_ctx_ref_sp);
  }

  if (!ret_val)
    error.SetErrorString("unable to execute script function");
  else
    error.Clear();

  return ret_val;
}

bool ScriptInterpreterPython::RunScriptBasedCommand(
    StructuredData::GenericSP impl_obj_sp, llvm::StringRef args,
    ScriptedCommandSynchronicity synchronicity,
    lldb_private::CommandReturnObject &cmd_retobj, Status &error,
    const lldb_private::ExecutionContext &exe_ctx) {
  if (!impl_obj_sp || !impl_obj_sp->IsValid()) {
    error.SetErrorString("no function to execute");
    return false;
  }

  lldb::DebuggerSP debugger_sp = m_interpreter.GetDebugger().shared_from_this();
  lldb::ExecutionContextRefSP exe_ctx_ref_sp(new ExecutionContextRef(exe_ctx));

  if (!debugger_sp.get()) {
    error.SetErrorString("invalid Debugger pointer");
    return false;
  }

  bool ret_val = false;

  std::string err_msg;

  {
    Locker py_lock(this,
                   Locker::AcquireLock | Locker::InitSession |
                       (cmd_retobj.GetInteractive() ? 0 : Locker::NoSTDIN),
                   Locker::FreeLock | Locker::TearDownSession);

    SynchronicityHandler synch_handler(debugger_sp, synchronicity);

    std::string args_str = args.str();
    ret_val = LLDBSwigPythonCallCommandObject(impl_obj_sp->GetValue(),
                                              debugger_sp, args_str.c_str(),
                                              cmd_retobj, exe_ctx_ref_sp);
  }

  if (!ret_val)
    error.SetErrorString("unable to execute script function");
  else
    error.Clear();

  return ret_val;
}

// in Python, a special attribute __doc__ contains the docstring for an object
// (function, method, class, ...) if any is defined Otherwise, the attribute's
// value is None
bool ScriptInterpreterPython::GetDocumentationForItem(const char *item,
                                                      std::string &dest) {
  dest.clear();
  if (!item || !*item)
    return false;
  std::string command(item);
  command += ".__doc__";

  char *result_ptr = nullptr; // Python is going to point this to valid data if
                              // ExecuteOneLineWithReturn returns successfully

  if (ExecuteOneLineWithReturn(
          command.c_str(), ScriptInterpreter::eScriptReturnTypeCharStrOrNone,
          &result_ptr,
          ScriptInterpreter::ExecuteScriptOptions().SetEnableIO(false))) {
    if (result_ptr)
      dest.assign(result_ptr);
    return true;
  } else {
    StreamString str_stream;
    str_stream.Printf(
        "Function %s was not found. Containing module might be missing.", item);
    dest = str_stream.GetString();
    return false;
  }
}

bool ScriptInterpreterPython::GetShortHelpForCommandObject(
    StructuredData::GenericSP cmd_obj_sp, std::string &dest) {
  bool got_string = false;
  dest.clear();

  Locker py_lock(this, Locker::AcquireLock | Locker::NoSTDIN, Locker::FreeLock);

  static char callee_name[] = "get_short_help";

  if (!cmd_obj_sp)
    return false;

  PythonObject implementor(PyRefType::Borrowed,
                           (PyObject *)cmd_obj_sp->GetValue());

  if (!implementor.IsAllocated())
    return false;

  PythonObject pmeth(PyRefType::Owned,
                     PyObject_GetAttrString(implementor.get(), callee_name));

  if (PyErr_Occurred())
    PyErr_Clear();

  if (!pmeth.IsAllocated())
    return false;

  if (PyCallable_Check(pmeth.get()) == 0) {
    if (PyErr_Occurred())
      PyErr_Clear();
    return false;
  }

  if (PyErr_Occurred())
    PyErr_Clear();

  // right now we know this function exists and is callable..
  PythonObject py_return(
      PyRefType::Owned,
      PyObject_CallMethod(implementor.get(), callee_name, nullptr));

  // if it fails, print the error but otherwise go on
  if (PyErr_Occurred()) {
    PyErr_Print();
    PyErr_Clear();
  }

  if (py_return.IsAllocated() && PythonString::Check(py_return.get())) {
    PythonString py_string(PyRefType::Borrowed, py_return.get());
    llvm::StringRef return_data(py_string.GetString());
    dest.assign(return_data.data(), return_data.size());
    got_string = true;
  }
  return got_string;
}

uint32_t ScriptInterpreterPython::GetFlagsForCommandObject(
    StructuredData::GenericSP cmd_obj_sp) {
  uint32_t result = 0;

  Locker py_lock(this, Locker::AcquireLock | Locker::NoSTDIN, Locker::FreeLock);

  static char callee_name[] = "get_flags";

  if (!cmd_obj_sp)
    return result;

  PythonObject implementor(PyRefType::Borrowed,
                           (PyObject *)cmd_obj_sp->GetValue());

  if (!implementor.IsAllocated())
    return result;

  PythonObject pmeth(PyRefType::Owned,
                     PyObject_GetAttrString(implementor.get(), callee_name));

  if (PyErr_Occurred())
    PyErr_Clear();

  if (!pmeth.IsAllocated())
    return result;

  if (PyCallable_Check(pmeth.get()) == 0) {
    if (PyErr_Occurred())
      PyErr_Clear();
    return result;
  }

  if (PyErr_Occurred())
    PyErr_Clear();

  // right now we know this function exists and is callable..
  PythonObject py_return(
      PyRefType::Owned,
      PyObject_CallMethod(implementor.get(), callee_name, nullptr));

  // if it fails, print the error but otherwise go on
  if (PyErr_Occurred()) {
    PyErr_Print();
    PyErr_Clear();
  }

  if (py_return.IsAllocated() && PythonInteger::Check(py_return.get())) {
    PythonInteger int_value(PyRefType::Borrowed, py_return.get());
    result = int_value.GetInteger();
  }

  return result;
}

bool ScriptInterpreterPython::GetLongHelpForCommandObject(
    StructuredData::GenericSP cmd_obj_sp, std::string &dest) {
  bool got_string = false;
  dest.clear();

  Locker py_lock(this, Locker::AcquireLock | Locker::NoSTDIN, Locker::FreeLock);

  static char callee_name[] = "get_long_help";

  if (!cmd_obj_sp)
    return false;

  PythonObject implementor(PyRefType::Borrowed,
                           (PyObject *)cmd_obj_sp->GetValue());

  if (!implementor.IsAllocated())
    return false;

  PythonObject pmeth(PyRefType::Owned,
                     PyObject_GetAttrString(implementor.get(), callee_name));

  if (PyErr_Occurred())
    PyErr_Clear();

  if (!pmeth.IsAllocated())
    return false;

  if (PyCallable_Check(pmeth.get()) == 0) {
    if (PyErr_Occurred())
      PyErr_Clear();

    return false;
  }

  if (PyErr_Occurred())
    PyErr_Clear();

  // right now we know this function exists and is callable..
  PythonObject py_return(
      PyRefType::Owned,
      PyObject_CallMethod(implementor.get(), callee_name, nullptr));

  // if it fails, print the error but otherwise go on
  if (PyErr_Occurred()) {
    PyErr_Print();
    PyErr_Clear();
  }

  if (py_return.IsAllocated() && PythonString::Check(py_return.get())) {
    PythonString str(PyRefType::Borrowed, py_return.get());
    llvm::StringRef str_data(str.GetString());
    dest.assign(str_data.data(), str_data.size());
    got_string = true;
  }

  return got_string;
}

std::unique_ptr<ScriptInterpreterLocker>
ScriptInterpreterPython::AcquireInterpreterLock() {
  std::unique_ptr<ScriptInterpreterLocker> py_lock(new Locker(
      this, Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN,
      Locker::FreeLock | Locker::TearDownSession));
  return py_lock;
}

void ScriptInterpreterPython::InitializePrivate() {
  if (g_initialized)
    return;

  g_initialized = true;

  static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
  Timer scoped_timer(func_cat, LLVM_PRETTY_FUNCTION);

  // RAII-based initialization which correctly handles multiple-initialization,
  // version- specific differences among Python 2 and Python 3, and saving and
  // restoring various other pieces of state that can get mucked with during
  // initialization.
  InitializePythonRAII initialize_guard;

  LLDBSwigPyInit();

  // Update the path python uses to search for modules to include the current
  // directory.

  PyRun_SimpleString("import sys");
  AddToSysPath(AddLocation::End, ".");

  // Don't denormalize paths when calling file_spec.GetPath().  On platforms
  // that use a backslash as the path separator, this will result in executing
  // python code containing paths with unescaped backslashes.  But Python also
  // accepts forward slashes, so to make life easier we just use that.
  if (FileSpec file_spec = GetPythonDir())
    AddToSysPath(AddLocation::Beginning, file_spec.GetPath(false));
  if (FileSpec file_spec = HostInfo::GetShlibDir())
    AddToSysPath(AddLocation::Beginning, file_spec.GetPath(false));

  PyRun_SimpleString("sys.dont_write_bytecode = 1; import "
                     "lldb.embedded_interpreter; from "
                     "lldb.embedded_interpreter import run_python_interpreter; "
                     "from lldb.embedded_interpreter import run_one_line");
}

void ScriptInterpreterPython::AddToSysPath(AddLocation location,
                                           std::string path) {
  std::string path_copy;

  std::string statement;
  if (location == AddLocation::Beginning) {
    statement.assign("sys.path.insert(0,\"");
    statement.append(path);
    statement.append("\")");
  } else {
    statement.assign("sys.path.append(\"");
    statement.append(path);
    statement.append("\")");
  }
  PyRun_SimpleString(statement.c_str());
}

// We are intentionally NOT calling Py_Finalize here (this would be the logical
// place to call it).  Calling Py_Finalize here causes test suite runs to seg
// fault:  The test suite runs in Python.  It registers SBDebugger::Terminate to
// be called 'at_exit'.  When the test suite Python harness finishes up, it
// calls Py_Finalize, which calls all the 'at_exit' registered functions.
// SBDebugger::Terminate calls Debugger::Terminate, which calls lldb::Terminate,
// which calls ScriptInterpreter::Terminate, which calls
// ScriptInterpreterPython::Terminate.  So if we call Py_Finalize here, we end
// up with Py_Finalize being called from within Py_Finalize, which results in a
// seg fault. Since this function only gets called when lldb is shutting down
// and going away anyway, the fact that we don't actually call Py_Finalize
// should not cause any problems (everything should shut down/go away anyway
// when the process exits).
//
// void ScriptInterpreterPython::Terminate() { Py_Finalize (); }

#endif // LLDB_DISABLE_PYTHON