//===-- OperatingSystemPython.cpp -----------------------------------------===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

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

#include "lldb/Host/Config.h"

#if LLDB_ENABLE_PYTHON

#include "OperatingSystemPython.h"

#include "Plugins/Process/Utility/RegisterContextDummy.h"

#include "Plugins/Process/Utility/RegisterContextMemory.h"

#include "Plugins/Process/Utility/ThreadMemory.h"

#include "lldb/Core/Debugger.h"

#include "lldb/Core/Module.h"

#include "lldb/Core/PluginManager.h"

#include "lldb/Core/ValueObjectVariable.h"

#include "lldb/Interpreter/CommandInterpreter.h"

#include "lldb/Interpreter/ScriptInterpreter.h"

#include "lldb/Symbol/ObjectFile.h"

#include "lldb/Symbol/VariableList.h"

#include "lldb/Target/Process.h"

#include "lldb/Target/StopInfo.h"

#include "lldb/Target/Target.h"

#include "lldb/Target/Thread.h"

#include "lldb/Target/ThreadList.h"

#include "lldb/Utility/DataBufferHeap.h"

#include "lldb/Utility/LLDBLog.h"

#include "lldb/Utility/RegisterValue.h"

#include "lldb/Utility/StreamString.h"

#include "lldb/Utility/StructuredData.h"

#include <memory>

using namespace lldb;

using namespace lldb_private;

LLDB_PLUGIN_DEFINE(OperatingSystemPython)

void OperatingSystemPython::Initialize() {

  PluginManager::RegisterPlugin(GetPluginNameStatic(),

                                GetPluginDescriptionStatic(), CreateInstance,

                                nullptr);

}

void OperatingSystemPython::Terminate() {

  PluginManager::UnregisterPlugin(CreateInstance);

}

OperatingSystem *OperatingSystemPython::CreateInstance(Process *process,

                                                       bool force) {

  // Python OperatingSystem plug-ins must be requested by name, so force must

  // be true

  FileSpec python_os_plugin_spec(process->GetPythonOSPluginPath());

  if (python_os_plugin_spec &&

      
FileSystem::Instance().Exists(python_os_plugin_spec)8
) {

    std::unique_ptr<OperatingSystemPython> os_up(

        new OperatingSystemPython(process, python_os_plugin_spec));

    if (os_up.get() && os_up->IsValid())

      return os_up.release();

  }

  return nullptr;

}

llvm::StringRef OperatingSystemPython::GetPluginDescriptionStatic() {

  return "Operating system plug-in that gathers OS information from a python "

         "class that implements the necessary OperatingSystem functionality.";

}

OperatingSystemPython::OperatingSystemPython(lldb_private::Process *process,

                                             const FileSpec &python_module_path)

    : OperatingSystem(process), m_thread_list_valobj_sp(), m_register_info_up(),

      m_interpreter(nullptr), m_python_object_sp() {

  if (!process)

    return;

  TargetSP target_sp = process->CalculateTarget();

  if (!target_sp)

    return;

  m_interpreter = target_sp->GetDebugger().GetScriptInterpreter();

  if (m_interpreter) {

    std::string os_plugin_class_name(

        python_module_path.GetFilename().AsCString(""));

    if (!os_plugin_class_name.empty()) {

      LoadScriptOptions options;

      char python_module_path_cstr[PATH_MAX];

      python_module_path.GetPath(python_module_path_cstr,

                                 sizeof(python_module_path_cstr));

      Status error;

      if (m_interpreter->LoadScriptingModule(python_module_path_cstr, options,

                                             error)) {

        // Strip the ".py" extension if there is one

        size_t py_extension_pos = os_plugin_class_name.rfind(".py");

        if (py_extension_pos != std::string::npos)

          os_plugin_class_name.erase(py_extension_pos);

        // Add ".OperatingSystemPlugIn" to the module name to get a string like

        // "modulename.OperatingSystemPlugIn"

        os_plugin_class_name += ".OperatingSystemPlugIn";

        StructuredData::ObjectSP object_sp =

            m_interpreter->OSPlugin_CreatePluginObject(

                os_plugin_class_name.c_str(), process->CalculateProcess());

        if (object_sp && object_sp->IsValid())

          m_python_object_sp = object_sp;

      }

    }

  }

}

OperatingSystemPython::~OperatingSystemPython() = default;

DynamicRegisterInfo *OperatingSystemPython::GetDynamicRegisterInfo() {

  if (m_register_info_up == nullptr) {

    if (!m_interpreter || !m_python_object_sp)

      return nullptr;

    Log *log = GetLog(LLDBLog::OS);

    LLDB_LOGF(log,

              "OperatingSystemPython::GetDynamicRegisterInfo() fetching "

              "thread register definitions from python for pid %" PRIu64,

              m_process->GetID());

    StructuredData::DictionarySP dictionary =

        m_interpreter->OSPlugin_RegisterInfo(m_python_object_sp);

    if (!dictionary)

      return nullptr;

    m_register_info_up = DynamicRegisterInfo::Create(

        *dictionary, m_process->GetTarget().GetArchitecture());

    assert(m_register_info_up);

    assert(m_register_info_up->GetNumRegisters() > 0);

    assert(m_register_info_up->GetNumRegisterSets() > 0);

  }

  return m_register_info_up.get();

}

bool OperatingSystemPython::UpdateThreadList(ThreadList &old_thread_list,

                                             ThreadList &core_thread_list,

                                             ThreadList &new_thread_list) {

  if (!m_interpreter || !m_python_object_sp)

    return false;

  Log *log = GetLog(LLDBLog::OS);

  // First thing we have to do is to try to get the API lock, and the

  // interpreter lock. We're going to change the thread content of the process,

  // and we're going to use python, which requires the API lock to do it. We

  // need the interpreter lock to make sure thread_info_dict stays alive.

  //

  // If someone already has the API lock, that is ok, we just want to avoid

  // external code from making new API calls while this call is happening.

  //

  // This is a recursive lock so we can grant it to any Python code called on

  // the stack below us.

  Target &target = m_process->GetTarget();

  std::unique_lock<std::recursive_mutex> api_lock(target.GetAPIMutex(),

                                                  std::defer_lock);

  (void)api_lock.try_lock(); // See above.

  auto interpreter_lock = m_interpreter->AcquireInterpreterLock();

  LLDB_LOGF(log,

            "OperatingSystemPython::UpdateThreadList() fetching thread "

            "data from python for pid %" PRIu64,

            m_process->GetID());

  // The threads that are in "core_thread_list" upon entry are the threads from

  // the lldb_private::Process subclass, no memory threads will be in this

  // list.

  StructuredData::ArraySP threads_list =

      m_interpreter->OSPlugin_ThreadsInfo(m_python_object_sp);

  const uint32_t num_cores = core_thread_list.GetSize(false);

  // Make a map so we can keep track of which cores were used from the

  // core_thread list. Any real threads/cores that weren't used should later be

  // put back into the "new_thread_list".

  std::vector<bool> core_used_map(num_cores, false);

  if (threads_list) {

    if (log) {

      StreamString strm;

      threads_list->Dump(strm);

      LLDB_LOGF(log, "threads_list = %s", strm.GetData());

    }

    const uint32_t num_threads = threads_list->GetSize();

    for (uint32_t i = 0; i < num_threads; 
++i24
) {

      StructuredData::ObjectSP thread_dict_obj =

          threads_list->GetItemAtIndex(i);

      if (auto thread_dict = thread_dict_obj->GetAsDictionary()) {

        ThreadSP thread_sp(CreateThreadFromThreadInfo(

            *thread_dict, core_thread_list, old_thread_list, core_used_map,

            nullptr));

        if (thread_sp)

          new_thread_list.AddThread(thread_sp);

      }

    }

  }

  // Any real core threads that didn't end up backing a memory thread should

  // still be in the main thread list, and they should be inserted at the

  // beginning of the list

  uint32_t insert_idx = 0;

  for (uint32_t core_idx = 0; core_idx < num_cores; 
++core_idx27
) {

    if (!core_used_map[core_idx]) {

      new_thread_list.InsertThread(

          core_thread_list.GetThreadAtIndex(core_idx, false), insert_idx);

      ++insert_idx;

    }

  }

  return new_thread_list.GetSize(false) > 0;

}

ThreadSP OperatingSystemPython::CreateThreadFromThreadInfo(

    StructuredData::Dictionary &thread_dict, ThreadList &core_thread_list,

    ThreadList &old_thread_list, std::vector<bool> &core_used_map,

    bool *did_create_ptr) {

  ThreadSP thread_sp;

  tid_t tid = LLDB_INVALID_THREAD_ID;

  if (!thread_dict.GetValueForKeyAsInteger("tid", tid))

    return ThreadSP();

  uint32_t core_number;

  addr_t reg_data_addr;

  llvm::StringRef name;

  llvm::StringRef queue;

  thread_dict.GetValueForKeyAsInteger("core", core_number, UINT32_MAX);

  thread_dict.GetValueForKeyAsInteger("register_data_addr", reg_data_addr,

                                      LLDB_INVALID_ADDRESS);

  thread_dict.GetValueForKeyAsString("name", name);

  thread_dict.GetValueForKeyAsString("queue", queue);

  // See if a thread already exists for "tid"

  thread_sp = old_thread_list.FindThreadByID(tid, false);

  if (thread_sp) {

    // A thread already does exist for "tid", make sure it was an operating

    // system

    // plug-in generated thread.

    if (!IsOperatingSystemPluginThread(thread_sp)) {

      // We have thread ID overlap between the protocol threads and the

      // operating system threads, clear the thread so we create an operating

      // system thread for this.

      thread_sp.reset();

    }

  }

  if (!thread_sp) {

    if (did_create_ptr)

      *did_create_ptr = true;

    thread_sp = std::make_shared<ThreadMemory>(*m_process, tid, name, queue,

                                               reg_data_addr);

  }

  if (core_number < core_thread_list.GetSize(false)) {

    ThreadSP core_thread_sp(

        core_thread_list.GetThreadAtIndex(core_number, false));

    if (core_thread_sp) {

      // Keep track of which cores were set as the backing thread for memory

      // threads...

      if (core_number < core_used_map.size())

        core_used_map[core_number] = true;

      ThreadSP backing_core_thread_sp(core_thread_sp->GetBackingThread());

      if (backing_core_thread_sp) {

        thread_sp->SetBackingThread(backing_core_thread_sp);

      } else {

        thread_sp->SetBackingThread(core_thread_sp);

      }

    }

  }

  return thread_sp;

}

void OperatingSystemPython::ThreadWasSelected(Thread *thread) {}

RegisterContextSP

OperatingSystemPython::CreateRegisterContextForThread(Thread *thread,

                                                      addr_t reg_data_addr) {

  RegisterContextSP reg_ctx_sp;

  if (!m_interpreter || !m_python_object_sp || !thread)

    return reg_ctx_sp;

  if (!IsOperatingSystemPluginThread(thread->shared_from_this()))

    return reg_ctx_sp;

  // First thing we have to do is to try to get the API lock, and the

  // interpreter lock. We're going to change the thread content of the process,

  // and we're going to use python, which requires the API lock to do it. We

  // need the interpreter lock to make sure thread_info_dict stays alive.

  //

  // If someone already has the API lock, that is ok, we just want to avoid

  // external code from making new API calls while this call is happening.

  //

  // This is a recursive lock so we can grant it to any Python code called on

  // the stack below us.

  Target &target = m_process->GetTarget();

  std::unique_lock<std::recursive_mutex> api_lock(target.GetAPIMutex(),

                                                  std::defer_lock);

  (void)api_lock.try_lock(); // See above.

  auto interpreter_lock = m_interpreter->AcquireInterpreterLock();

  Log *log = GetLog(LLDBLog::Thread);

  if (reg_data_addr != LLDB_INVALID_ADDRESS) {

    // The registers data is in contiguous memory, just create the register

    // context using the address provided

    LLDB_LOGF(log,

              "OperatingSystemPython::CreateRegisterContextForThread (tid "

              "= 0x%" PRIx64 ", 0x%" PRIx64 ", reg_data_addr = 0x%" PRIx64

              ") creating memory register context",

              thread->GetID(), thread->GetProtocolID(), reg_data_addr);

    reg_ctx_sp = std::make_shared<RegisterContextMemory>(

        *thread, 0, *GetDynamicRegisterInfo(), reg_data_addr);

  } else {

    // No register data address is provided, query the python plug-in to let it

    // make up the data as it sees fit

    LLDB_LOGF(log,

              "OperatingSystemPython::CreateRegisterContextForThread (tid "

              "= 0x%" PRIx64 ", 0x%" PRIx64

              ") fetching register data from python",

              thread->GetID(), thread->GetProtocolID());

    StructuredData::StringSP reg_context_data =

        m_interpreter->OSPlugin_RegisterContextData(m_python_object_sp,

                                                    thread->GetID());

    if (reg_context_data) {

      std::string value = std::string(reg_context_data->GetValue());

      DataBufferSP data_sp(new DataBufferHeap(value.c_str(), value.length()));

      if (data_sp->GetByteSize()) {

        RegisterContextMemory *reg_ctx_memory = new RegisterContextMemory(

            *thread, 0, *GetDynamicRegisterInfo(), LLDB_INVALID_ADDRESS);

        if (reg_ctx_memory) {

          reg_ctx_sp.reset(reg_ctx_memory);

          reg_ctx_memory->SetAllRegisterData(data_sp);

        }

      }

    }

  }

  // if we still have no register data, fallback on a dummy context to avoid

  // crashing

  if (!reg_ctx_sp) {

    LLDB_LOGF(log,

              "OperatingSystemPython::CreateRegisterContextForThread (tid "

              "= 0x%" PRIx64 ") forcing a dummy register context",

              thread->GetID());

    reg_ctx_sp = std::make_shared<RegisterContextDummy>(

        *thread, 0, target.GetArchitecture().GetAddressByteSize());

  }

  return reg_ctx_sp;

}

StopInfoSP

OperatingSystemPython::CreateThreadStopReason(lldb_private::Thread *thread) {

  // We should have gotten the thread stop info from the dictionary of data for

  // the thread in the initial call to get_thread_info(), this should have been

  // cached so we can return it here

  StopInfoSP

      stop_info_sp; //(StopInfo::CreateStopReasonWithSignal (*thread, SIGSTOP));

  return stop_info_sp;

}

lldb::ThreadSP OperatingSystemPython::CreateThread(lldb::tid_t tid,

                                                   addr_t context) {

  Log *log = GetLog(LLDBLog::Thread);

  LLDB_LOGF(log,

            "OperatingSystemPython::CreateThread (tid = 0x%" PRIx64

            ", context = 0x%" PRIx64 ") fetching register data from python",

            tid, context);

  if (m_interpreter && m_python_object_sp) {

    // First thing we have to do is to try to get the API lock, and the

    // interpreter lock. We're going to change the thread content of the

    // process, and we're going to use python, which requires the API lock to

    // do it. We need the interpreter lock to make sure thread_info_dict stays

    // alive.

    //

    // If someone already has the API lock, that is ok, we just want to avoid

    // external code from making new API calls while this call is happening.

    //

    // This is a recursive lock so we can grant it to any Python code called on

    // the stack below us.

    Target &target = m_process->GetTarget();

    std::unique_lock<std::recursive_mutex> api_lock(target.GetAPIMutex(),

                                                    std::defer_lock);

    (void)api_lock.try_lock(); // See above.

    auto interpreter_lock = m_interpreter->AcquireInterpreterLock();

    StructuredData::DictionarySP thread_info_dict =

        m_interpreter->OSPlugin_CreateThread(m_python_object_sp, tid, context);

    std::vector<bool> core_used_map;

    if (thread_info_dict) {

      ThreadList core_threads(m_process);

      ThreadList &thread_list = m_process->GetThreadList();

      bool did_create = false;

      ThreadSP thread_sp(

          CreateThreadFromThreadInfo(*thread_info_dict, core_threads,

                                     thread_list, core_used_map, &did_create));

      if (did_create)

        thread_list.AddThread(thread_sp);

      return thread_sp;

    }

  }

  return ThreadSP();

}

#endif // #if LLDB_ENABLE_PYTHON