[lldb/Interpreter] Introduce `ScriptedStopHook{,Python}Interface` & make use of it (#105449)

This patch introduces new `ScriptedStopHook{,Python}Interface` classes
that make use of the Scripted Interface infrastructure and makes use of
it in `StopHookScripted`.

It also relax the requirement on the number of argument for initializing
scripting extension if the size of the interface parameter pack contains
1 less element than the extension maximum number of positional arguments
for this initializer.
This addresses the cases where the embedded interpreter session
dictionary is passed to the extension initializer which is not used most
of the time.

---------

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>

1 files changed, 75 insertions, 0 deletions

diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedStopHookPythonInterface.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedStopHookPythonInterface.cpp
new file mode 100644
index 000000000000..6cec7d6e7553
--- /dev/null
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedStopHookPythonInterface.cpp
@@ -0,0 +1,75 @@
+//===-- ScriptedStopHookPythonInterface.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/Core/PluginManager.h"
+#include "lldb/Host/Config.h"
+#include "lldb/Target/ExecutionContext.h"
+#include "lldb/Utility/Log.h"
+#include "lldb/lldb-enumerations.h"
+
+#if LLDB_ENABLE_PYTHON
+
+// clang-format off
+// LLDB Python header must be included first
+#include "../lldb-python.h"
+//clang-format on
+
+#include "../SWIGPythonBridge.h"
+#include "../ScriptInterpreterPythonImpl.h"
+#include "ScriptedStopHookPythonInterface.h"
+
+using namespace lldb;
+using namespace lldb_private;
+using namespace lldb_private::python;
+
+ScriptedStopHookPythonInterface::ScriptedStopHookPythonInterface(
+    ScriptInterpreterPythonImpl &interpreter)
+    : ScriptedStopHookInterface(), ScriptedPythonInterface(interpreter) {}
+
+llvm::Expected<StructuredData::GenericSP>
+ScriptedStopHookPythonInterface::CreatePluginObject(llvm::StringRef class_name,
+                                                    lldb::TargetSP target_sp,
+                                                    const StructuredDataImpl &args_sp) {
+  return ScriptedPythonInterface::CreatePluginObject(class_name, nullptr,
+                                                     target_sp, args_sp);
+}
+
+llvm::Expected<bool>
+ScriptedStopHookPythonInterface::HandleStop(ExecutionContext &exe_ctx,
+                                            lldb::StreamSP output_sp) {
+  ExecutionContextRefSP exe_ctx_ref_sp =
+      std::make_shared<ExecutionContextRef>(exe_ctx);
+  Status error;
+  StructuredData::ObjectSP obj = Dispatch("handle_stop", error, exe_ctx_ref_sp, output_sp);
+
+  if (!ScriptedInterface::CheckStructuredDataObject(LLVM_PRETTY_FUNCTION, obj,
+                                                    error)) {
+    if (!obj)
+      return true;
+    return error.ToError();
+  }
+
+  return obj->GetBooleanValue();
+}
+
+
+void ScriptedStopHookPythonInterface::Initialize() {
+  const std::vector<llvm::StringRef> ci_usages = {
+      "target stop-hook add -P <script-name> [-k key -v value ...]"};
+  const std::vector<llvm::StringRef> api_usages = {};
+  PluginManager::RegisterPlugin(
+      GetPluginNameStatic(),
+      llvm::StringRef("Perform actions whenever the process stops, before control is returned to the user."),
+      CreateInstance, eScriptLanguagePython, {ci_usages, api_usages});
+}
+
+void ScriptedStopHookPythonInterface::Terminate() {
+  PluginManager::UnregisterPlugin(CreateInstance);
+}
+
+#endif