[lldb/Plugins] Add support for ScriptedThread in ScriptedProcess

This patch introduces the `ScriptedThread` class with its python
interface.

When used with `ScriptedProcess`, `ScriptedThreaad` can provide various
information such as the thread state, stop reason or even its register
context.

This can be used to reconstruct the program stack frames using lldb's unwinder.

rdar://74503836

Differential Revision: https://reviews.llvm.org/D107585

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>

lldb/source/Plugins/ScriptInterpreter/Python/ScriptedThreadPythonInterface.cpp

@@ -0,0 +1,136 @@
+//===-- ScriptedThreadPythonInterface.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"
+#include "lldb/Utility/Log.h"
+#include "lldb/Utility/Logging.h"
+#include "lldb/lldb-enumerations.h"
+
+#if LLDB_ENABLE_PYTHON
+
+// LLDB Python header must be included first
+#include "lldb-python.h"
+
+#include "SWIGPythonBridge.h"
+#include "ScriptInterpreterPythonImpl.h"
+#include "ScriptedThreadPythonInterface.h"
+
+using namespace lldb;
+using namespace lldb_private;
+using namespace lldb_private::python;
+using Locker = ScriptInterpreterPythonImpl::Locker;
+
+ScriptedThreadPythonInterface::ScriptedThreadPythonInterface(
+    ScriptInterpreterPythonImpl &interpreter)
+    : ScriptedThreadInterface(), ScriptedPythonInterface(interpreter) {}
+
+StructuredData::GenericSP ScriptedThreadPythonInterface::CreatePluginObject(
+    const llvm::StringRef class_name, ExecutionContext &exe_ctx,
+    StructuredData::DictionarySP args_sp) {
+
+  if (class_name.empty())
+    return {};
+
+  Locker py_lock(&m_interpreter, Locker::AcquireLock | Locker::NoSTDIN,
+                 Locker::FreeLock);
+
+  std::string error_string;
+
+  TargetSP target_sp = exe_ctx.GetTargetSP();
+
+  void *ret_val = LLDBSwigPythonCreateScriptedThread(
+      class_name.str().c_str(), m_interpreter.GetDictionaryName(), target_sp,
+      error_string);
+
+  if (!ret_val)
+    return {};
+
+  m_object_instance_sp =
+      StructuredData::GenericSP(new StructuredPythonObject(ret_val));
+
+  return m_object_instance_sp;
+}
+
+lldb::tid_t ScriptedThreadPythonInterface::GetThreadID() {
+  Status error;
+  StructuredData::ObjectSP obj = Dispatch("get_thread_id", error);
+
+  if (!CheckStructuredDataObject(__PRETTY_FUNCTION__, obj, error))
+    return LLDB_INVALID_THREAD_ID;
+
+  return obj->GetIntegerValue(LLDB_INVALID_THREAD_ID);
+}
+
+llvm::Optional<std::string> ScriptedThreadPythonInterface::GetName() {
+  Status error;
+  StructuredData::ObjectSP obj = Dispatch("get_name", error);
+
+  if (!CheckStructuredDataObject(__PRETTY_FUNCTION__, obj, error))
+    return {};
+
+  return obj->GetStringValue().str();
+}
+
+lldb::StateType ScriptedThreadPythonInterface::GetState() {
+  Status error;
+  StructuredData::ObjectSP obj = Dispatch("get_state", error);
+
+  if (!CheckStructuredDataObject(__PRETTY_FUNCTION__, obj, error))
+    return eStateInvalid;
+
+  return static_cast<StateType>(obj->GetIntegerValue(eStateInvalid));
+}
+
+llvm::Optional<std::string> ScriptedThreadPythonInterface::GetQueue() {
+  Status error;
+  StructuredData::ObjectSP obj = Dispatch("get_queue", error);
+
+  if (!CheckStructuredDataObject(__PRETTY_FUNCTION__, obj, error))
+    return {};
+
+  return obj->GetStringValue().str();
+}
+
+StructuredData::DictionarySP ScriptedThreadPythonInterface::GetStopReason() {
+  Status error;
+  StructuredData::DictionarySP dict =
+      Dispatch<StructuredData::DictionarySP>("get_stop_reason", error);
+
+  if (!CheckStructuredDataObject(__PRETTY_FUNCTION__, dict, error))
+    return {};
+
+  return dict;
+}
+
+StructuredData::ArraySP ScriptedThreadPythonInterface::GetStackFrames() {
+  return nullptr;
+}
+
+StructuredData::DictionarySP ScriptedThreadPythonInterface::GetRegisterInfo() {
+  Status error;
+  StructuredData::DictionarySP dict =
+      Dispatch<StructuredData::DictionarySP>("get_register_info", error);
+
+  if (!CheckStructuredDataObject(__PRETTY_FUNCTION__, dict, error))
+    return {};
+
+  return dict;
+}
+
+llvm::Optional<std::string>
+ScriptedThreadPythonInterface::GetRegisterContext() {
+  Status error;
+  StructuredData::ObjectSP obj = Dispatch("get_register_context", error);
+
+  if (!CheckStructuredDataObject(__PRETTY_FUNCTION__, obj, error))
+    return {};
+
+  return obj->GetAsString()->GetValue().str();
+}
+
+#endif