[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.h

@@ -0,0 +1,48 @@
+//===-- ScriptedThreadPythonInterface.h ------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_SCRIPTEDTHREADPYTHONINTERFACE_H
+#define LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_SCRIPTEDTHREADPYTHONINTERFACE_H
+
+#include "lldb/Host/Config.h"
+
+#if LLDB_ENABLE_PYTHON
+
+#include "ScriptedPythonInterface.h"
+#include "lldb/Interpreter/ScriptedProcessInterface.h"
+
+namespace lldb_private {
+class ScriptedThreadPythonInterface : public ScriptedThreadInterface,
+                                      public ScriptedPythonInterface {
+public:
+  ScriptedThreadPythonInterface(ScriptInterpreterPythonImpl &interpreter);
+
+  StructuredData::GenericSP
+  CreatePluginObject(llvm::StringRef class_name, ExecutionContext &exe_ctx,
+                     StructuredData::DictionarySP args_sp) override;
+
+  lldb::tid_t GetThreadID() override;
+
+  llvm::Optional<std::string> GetName() override;
+
+  lldb::StateType GetState() override;
+
+  llvm::Optional<std::string> GetQueue() override;
+
+  StructuredData::DictionarySP GetStopReason() override;
+
+  StructuredData::ArraySP GetStackFrames() override;
+
+  StructuredData::DictionarySP GetRegisterInfo() override;
+
+  llvm::Optional<std::string> GetRegisterContext() override;
+};
+} // namespace lldb_private
+
+#endif // LLDB_ENABLE_PYTHON
+#endif // LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_SCRIPTEDPROCESSTHREADINTERFACE_H