[lldb] Make use of Scripted{Python,}Interface for ScriptedThreadPlan (#70392)

This patch makes ScriptedThreadPlan conforming to the ScriptedInterface
& ScriptedPythonInterface facilities by introducing 2
ScriptedThreadPlanInterface & ScriptedThreadPlanPythonInterface classes.

This allows us to get rid of every ScriptedThreadPlan-specific SWIG
method and re-use the same affordances as other scripting offordances,
like Scripted{Process,Thread,Platform} & OperatingSystem.

To do so, this adds new transformer methods for `ThreadPlan`, `Stream` &
`Event`, to allow the bijection between C++ objects and their python
counterparts.

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

1 files changed, 54 insertions, 43 deletions

diff --git a/lldb/source/Target/ThreadPlanPython.cpp b/lldb/source/Target/ThreadPlanPython.cpp
index d6de6b3..48b3e3a 100644
--- a/lldb/source/Target/ThreadPlanPython.cpp
+++ b/lldb/source/Target/ThreadPlanPython.cpp
@@ -32,6 +32,23 @@ ThreadPlanPython::ThreadPlanPython(Thread &thread, const char *class_name,
                  eVoteNoOpinion, eVoteNoOpinion),
       m_class_name(class_name), m_args_data(args_data), m_did_push(false),
       m_stop_others(false) {
+  ScriptInterpreter *interpreter = GetScriptInterpreter();
+  if (!interpreter) {
+    SetPlanComplete(false);
+    // FIXME: error handling
+    return;
+  }
+
+  m_interface = interpreter->CreateScriptedThreadPlanInterface();
+  if (!m_interface) {
+    SetPlanComplete(false);
+    // FIXME: error handling
+    // error.SetErrorStringWithFormat(
+    //     "ThreadPlanPython::%s () - ERROR: %s", __FUNCTION__,
+    //     "Script interpreter couldn't create Scripted Thread Plan Interface");
+    return;
+  }
+
   SetIsControllingPlan(true);
   SetOkayToDiscard(true);
   SetPrivate(false);
@@ -60,13 +77,14 @@ void ThreadPlanPython::DidPush() {
   // We set up the script side in DidPush, so that it can push other plans in
   // the constructor, and doesn't have to care about the details of DidPush.
   m_did_push = true;
-  if (!m_class_name.empty()) {
-    ScriptInterpreter *script_interp = GetScriptInterpreter();
-    if (script_interp) {
-      m_implementation_sp = script_interp->CreateScriptedThreadPlan(
-          m_class_name.c_str(), m_args_data, m_error_str, 
-          this->shared_from_this());
-    }
+  if (m_interface) {
+    auto obj_or_err = m_interface->CreatePluginObject(
+        m_class_name, this->shared_from_this(), m_args_data);
+    if (!obj_or_err) {
+      m_error_str = llvm::toString(obj_or_err.takeError());
+      SetPlanComplete(false);
+    } else
+      m_implementation_sp = *obj_or_err;
   }
 }
 
@@ -77,14 +95,13 @@ bool ThreadPlanPython::ShouldStop(Event *event_ptr) {
 
   bool should_stop = true;
   if (m_implementation_sp) {
-    ScriptInterpreter *script_interp = GetScriptInterpreter();
-    if (script_interp) {
-      bool script_error;
-      should_stop = script_interp->ScriptedThreadPlanShouldStop(
-          m_implementation_sp, event_ptr, script_error);
-      if (script_error)
-        SetPlanComplete(false);
-    }
+    auto should_stop_or_err = m_interface->ShouldStop(event_ptr);
+    if (!should_stop_or_err) {
+      LLDB_LOG_ERROR(GetLog(LLDBLog::Thread), should_stop_or_err.takeError(),
+                     "Can't call ScriptedThreadPlan::ShouldStop.");
+      SetPlanComplete(false);
+    } else
+      should_stop = *should_stop_or_err;
   }
   return should_stop;
 }
@@ -96,14 +113,13 @@ bool ThreadPlanPython::IsPlanStale() {
 
   bool is_stale = true;
   if (m_implementation_sp) {
-    ScriptInterpreter *script_interp = GetScriptInterpreter();
-    if (script_interp) {
-      bool script_error;
-      is_stale = script_interp->ScriptedThreadPlanIsStale(m_implementation_sp,
-                                                          script_error);
-      if (script_error)
-        SetPlanComplete(false);
-    }
+    auto is_stale_or_err = m_interface->IsStale();
+    if (!is_stale_or_err) {
+      LLDB_LOG_ERROR(GetLog(LLDBLog::Thread), is_stale_or_err.takeError(),
+                     "Can't call ScriptedThreadPlan::IsStale.");
+      SetPlanComplete(false);
+    } else
+      is_stale = *is_stale_or_err;
   }
   return is_stale;
 }
@@ -115,14 +131,14 @@ bool ThreadPlanPython::DoPlanExplainsStop(Event *event_ptr) {
 
   bool explains_stop = true;
   if (m_implementation_sp) {
-    ScriptInterpreter *script_interp = GetScriptInterpreter();
-    if (script_interp) {
-      bool script_error;
-      explains_stop = script_interp->ScriptedThreadPlanExplainsStop(
-          m_implementation_sp, event_ptr, script_error);
-      if (script_error)
-        SetPlanComplete(false);
-    }
+    auto explains_stop_or_error = m_interface->ExplainsStop(event_ptr);
+    if (!explains_stop_or_error) {
+      LLDB_LOG_ERROR(GetLog(LLDBLog::Thread),
+                     explains_stop_or_error.takeError(),
+                     "Can't call ScriptedThreadPlan::ExplainsStop.");
+      SetPlanComplete(false);
+    } else
+      explains_stop = *explains_stop_or_error;
   }
   return explains_stop;
 }
@@ -150,14 +166,8 @@ lldb::StateType ThreadPlanPython::GetPlanRunState() {
   LLDB_LOGF(log, "%s called on Python Thread Plan: %s )", LLVM_PRETTY_FUNCTION,
             m_class_name.c_str());
   lldb::StateType run_state = eStateRunning;
-  if (m_implementation_sp) {
-    ScriptInterpreter *script_interp = GetScriptInterpreter();
-    if (script_interp) {
-      bool script_error;
-      run_state = script_interp->ScriptedThreadPlanGetRunState(
-          m_implementation_sp, script_error);
-    }
-  }
+  if (m_implementation_sp)
+    run_state = m_interface->GetRunState();
   return run_state;
 }
 
@@ -168,12 +178,13 @@ void ThreadPlanPython::GetDescription(Stream *s, lldb::DescriptionLevel level) {
   if (m_implementation_sp) {
     ScriptInterpreter *script_interp = GetScriptInterpreter();
     if (script_interp) {
-      bool script_error;
-      bool added_desc = script_interp->ScriptedThreadPlanGetStopDescription(
-          m_implementation_sp, s, script_error);
-      if (script_error || !added_desc)
+      auto desc_or_err = m_interface->GetStopDescription(s);
+      if (!desc_or_err || !*desc_or_err) {
+        LLDB_LOG_ERROR(GetLog(LLDBLog::Thread), desc_or_err.takeError(),
+                       "Can't call ScriptedThreadPlan::GetStopDescription.");
         s->Printf("Python thread plan implemented by class %s.",
             m_class_name.c_str());
+      }
     }
     return;
   }