[lldb/Interpreter] Discard ScriptedThreadPlan::GetStopDescription ret…

…urn value (#96985)

This patch changes `ScriptedThreadPlan::GetStopDescription` behavior by
discarding its return value since it is optional in the first place (the
user doesn't need to provide a return value in their implementation).

This patch also addresses the test failures in TestStepScripted
following 9a9ec22 and re-enables the tests that were XFAIL'd previously.

The issue here was that the `Stream*` that's passed to
`ThreadPlanPython::GetDescription` wasn't being passed by reference to
the python method so it was never updated to reflect how the python
method interacted with it.

This patch solves this issue by making a temporary `StreamSP` that will
be passed to the python method by reference, after what we will copy its
content to the caller `Stream` pointer argument.

---------

Signed-off-by: Med Ismail Bennani <[email protected]>

lldb/include/lldb/Interpreter/Interfaces/ScriptedThreadPlanInterface.h

@@ -29,8 +29,8 @@ class ScriptedThreadPlanInterface : public ScriptedInterface {
 
   virtual lldb::StateType GetRunState() { return lldb::eStateStepping; }
 
-  virtual llvm::Expected<bool> GetStopDescription(lldb_private::Stream *s) {
-    return true;
+  virtual llvm::Error GetStopDescription(lldb::StreamSP &stream) {
+    return llvm::Error::success();
   }
 };
 } // namespace lldb_private

lldb/include/lldb/Interpreter/ScriptInterpreter.h

@@ -575,7 +575,7 @@ class ScriptInterpreter : public PluginInterface {
 
   Event *GetOpaqueTypeFromSBEvent(const lldb::SBEvent &event) const;
 
-  Stream *GetOpaqueTypeFromSBStream(const lldb::SBStream &stream) const;
+  lldb::StreamSP GetOpaqueTypeFromSBStream(const lldb::SBStream &stream) const;
 
   lldb::BreakpointSP
   GetOpaqueTypeFromSBBreakpoint(const lldb::SBBreakpoint &breakpoint) const;

lldb/source/Interpreter/ScriptInterpreter.cpp

@@ -106,10 +106,13 @@ ScriptInterpreter::GetOpaqueTypeFromSBEvent(const lldb::SBEvent &event) const {
   return event.m_opaque_ptr;
 }
 
-Stream *ScriptInterpreter::GetOpaqueTypeFromSBStream(
+lldb::StreamSP ScriptInterpreter::GetOpaqueTypeFromSBStream(
     const lldb::SBStream &stream) const {
-  if (stream.m_opaque_up)
-    return const_cast<lldb::SBStream &>(stream).m_opaque_up.get();
+  if (stream.m_opaque_up) {
+    lldb::StreamSP s = std::make_shared<lldb_private::StreamString>();
+    *s << const_cast<lldb::SBStream &>(stream).GetData();
+    return s;
+  }
 
   return nullptr;
 }

lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedPythonInterface.cpp

@@ -26,15 +26,6 @@ ScriptedPythonInterface::ScriptedPythonInterface(
     ScriptInterpreterPythonImpl &interpreter)
     : ScriptedInterface(), m_interpreter(interpreter) {}
 
-template <>
-void ScriptedPythonInterface::ReverseTransform(
-    lldb_private::Stream *&original_arg, python::PythonObject transformed_arg,
-    Status &error) {
-  Stream *s = ExtractValueFromPythonObject<Stream *>(transformed_arg, error);
-  *original_arg = *s;
-  original_arg->PutCString(static_cast<StreamString *>(s)->GetData());
-}
-
 template <>
 StructuredData::ArraySP
 ScriptedPythonInterface::ExtractValueFromPythonObject<StructuredData::ArraySP>(
@@ -74,7 +65,8 @@ Event *ScriptedPythonInterface::ExtractValueFromPythonObject<Event *>(
 }
 
 template <>
-Stream *ScriptedPythonInterface::ExtractValueFromPythonObject<Stream *>(
+lldb::StreamSP
+ScriptedPythonInterface::ExtractValueFromPythonObject<lldb::StreamSP>(
     python::PythonObject &p, Status &error) {
   if (lldb::SBStream *sb_stream = reinterpret_cast<lldb::SBStream *>(
           python::LLDBSWIGPython_CastPyObjectToSBStream(p.get())))

lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedPythonInterface.h

@@ -341,8 +341,8 @@ class ScriptedPythonInterface : virtual public ScriptedInterface {
     return python::SWIGBridge::ToSWIGWrapper(arg);
   }
 
-  python::PythonObject Transform(Stream *arg) {
-    return python::SWIGBridge::ToSWIGWrapper(arg);
+  python::PythonObject Transform(lldb::StreamSP arg) {
+    return python::SWIGBridge::ToSWIGWrapper(arg.get());
   }
 
   python::PythonObject Transform(lldb::DataExtractorSP arg) {
@@ -447,7 +447,8 @@ Event *ScriptedPythonInterface::ExtractValueFromPythonObject<Event *>(
     python::PythonObject &p, Status &error);
 
 template <>
-Stream *ScriptedPythonInterface::ExtractValueFromPythonObject<Stream *>(
+lldb::StreamSP
+ScriptedPythonInterface::ExtractValueFromPythonObject<lldb::StreamSP>(
     python::PythonObject &p, Status &error);
 
 template <>

lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedThreadPlanPythonInterface.cpp

@@ -91,15 +91,15 @@ lldb::StateType ScriptedThreadPlanPythonInterface::GetRunState() {
       static_cast<uint32_t>(lldb::eStateStepping)));
 }
 
-llvm::Expected<bool>
-ScriptedThreadPlanPythonInterface::GetStopDescription(lldb_private::Stream *s) {
+llvm::Error
+ScriptedThreadPlanPythonInterface::GetStopDescription(lldb::StreamSP &stream) {
   Status error;
-  Dispatch("stop_description", error, s);
+  Dispatch("stop_description", error, stream);
 
   if (error.Fail())
     return error.ToError();
 
-  return true;
+  return llvm::Error::success();
 }
 
 #endif

lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedThreadPlanPythonInterface.h

@@ -40,7 +40,7 @@ class ScriptedThreadPlanPythonInterface : public ScriptedThreadPlanInterface,
 
   lldb::StateType GetRunState() override;
 
-  llvm::Expected<bool> GetStopDescription(lldb_private::Stream *s) override;
+  llvm::Error GetStopDescription(lldb::StreamSP &stream) override;
 };
 } // namespace lldb_private
 

lldb/source/Target/ThreadPlanPython.cpp

@@ -182,13 +182,16 @@ void ThreadPlanPython::GetDescription(Stream *s, lldb::DescriptionLevel level) {
   if (m_implementation_sp) {
     ScriptInterpreter *script_interp = GetScriptInterpreter();
     if (script_interp) {
-      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(),
+      lldb::StreamSP stream = std::make_shared<lldb_private::StreamString>();
+      llvm::Error err = m_interface->GetStopDescription(stream);
+      if (err) {
+        LLDB_LOG_ERROR(GetLog(LLDBLog::Thread), std::move(err),
                        "Can't call ScriptedThreadPlan::GetStopDescription.");
         s->Printf("Python thread plan implemented by class %s.",
             m_class_name.c_str());
-      }
+      } else
+        s->PutCString(
+            reinterpret_cast<StreamString *>(stream.get())->GetData());
     }
     return;
   }

lldb/test/API/functionalities/step_scripted/TestStepScripted.py

@@ -7,6 +7,7 @@
 from lldbsuite.test.decorators import *
 from lldbsuite.test.lldbtest import *
 
+
 class StepScriptedTestCase(TestBase):
     NO_DEBUG_INFO_TESTCASE = True
 
@@ -15,14 +16,12 @@ def setUp(self):
         self.main_source_file = lldb.SBFileSpec("main.c")
         self.runCmd("command script import Steps.py")
 
-    @expectedFailureAll()
     def test_standard_step_out(self):
         """Tests stepping with the scripted thread plan laying over a standard
         thread plan for stepping out."""
         self.build()
         self.step_out_with_scripted_plan("Steps.StepOut")
 
-    @expectedFailureAll()
     def test_scripted_step_out(self):
         """Tests stepping with the scripted thread plan laying over an another
         scripted thread plan for stepping out."""
@@ -63,12 +62,10 @@ def test_misspelled_plan_name(self):
         # Make sure we didn't let the process run:
         self.assertEqual(stop_id, process.GetStopID(), "Process didn't run")
 
-    @expectedFailureAll()
     def test_checking_variable(self):
         """Test that we can call SBValue API's from a scripted thread plan - using SBAPI's to step"""
         self.do_test_checking_variable(False)
 
-    @expectedFailureAll()
     def test_checking_variable_cli(self):
         """Test that we can call SBValue API's from a scripted thread plan - using cli to step"""
         self.do_test_checking_variable(True)