[lldb/python] Use PythonObject in LLDBSwigPython functions

Return our PythonObject wrappers instead of raw PyObjects (obfuscated as
void *). This ensures that ownership (reference counts) of python
objects is automatically tracked.

Differential Revision: https://reviews.llvm.org/D117462

1 files changed, 24 insertions, 33 deletions

diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.h b/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.h
index 9d2cdca..7dd8a74 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.h
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.h
@@ -83,39 +83,6 @@ protected:
   PyGILState_STATE m_state;
 };
 
-class StructuredPythonObject : public StructuredData::Generic {
-public:
-  StructuredPythonObject() : StructuredData::Generic() {}
-
-  StructuredPythonObject(void *obj) : StructuredData::Generic(obj) {
-    assert(PyGILState_Check());
-    Py_XINCREF(GetValue());
-  }
-
-  ~StructuredPythonObject() override {
-    if (Py_IsInitialized()) {
-      if (_Py_IsFinalizing()) {
-        // Leak GetValue() rather than crashing the process.
-        // https://docs.python.org/3/c-api/init.html#c.PyGILState_Ensure
-      } else {
-        PyGILState_STATE state = PyGILState_Ensure();
-        Py_XDECREF(GetValue());
-        PyGILState_Release(state);
-      }
-    }
-    SetValue(nullptr);
-  }
-
-  bool IsValid() const override { return GetValue() && GetValue() != Py_None; }
-
-  void Serialize(llvm::json::OStream &s) const override;
-
-private:
-  StructuredPythonObject(const StructuredPythonObject &) = delete;
-  const StructuredPythonObject &
-  operator=(const StructuredPythonObject &) = delete;
-};
-
 enum class PyObjectType {
   Unknown,
   None,
@@ -784,6 +751,30 @@ public:
   }
 };
 
+class StructuredPythonObject : public StructuredData::Generic {
+public:
+  StructuredPythonObject() : StructuredData::Generic() {}
+
+  // Take ownership of the object we received.
+  StructuredPythonObject(PythonObject obj)
+      : StructuredData::Generic(obj.release()) {}
+
+  ~StructuredPythonObject() override {
+    // Hand ownership back to a (temporary) PythonObject instance and let it
+    // take care of releasing it.
+    PythonObject(PyRefType::Owned, static_cast<PyObject *>(GetValue()));
+  }
+
+  bool IsValid() const override { return GetValue() && GetValue() != Py_None; }
+
+  void Serialize(llvm::json::OStream &s) const override;
+
+private:
+  StructuredPythonObject(const StructuredPythonObject &) = delete;
+  const StructuredPythonObject &
+  operator=(const StructuredPythonObject &) = delete;
+};
+
 } // namespace python
 } // namespace lldb_private