From 03819d1c80ad5d7b34f8fe0d375fcd2ef6aa5e7f Mon Sep 17 00:00:00 2001
From: Lawrence D'Anna <lawrence_danna@apple.com>
Date: Thu, 17 Oct 2019 22:22:09 +0000
Subject: [PATCH] eliminate one form of PythonObject::Reset()

Summary:
I'd like to eliminate all forms of Reset() and all public constructors
on these objects, so the only way to make them is with Take<> and Retain<>
and the only way to copy or move them is with actual c++ copy, move, or
assignment.

This is a simple place to start.

Reviewers: JDevlieghere, clayborg, labath, jingham

Reviewed By: labath

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D69080

llvm-svn: 375182
---
 .../Python/PythonDataObjects.cpp              |  2 +-
 .../Python/PythonDataObjects.h                | 30 +++----------------
 .../Python/PythonDataObjectsTests.cpp         | 20 ++++++-------
 3 files changed, 15 insertions(+), 37 deletions(-)

diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp
index 3ac404b532d3..1fb9355b9ee3 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp
@@ -410,7 +410,7 @@ void PythonString::SetString(llvm::StringRef string) {
     llvm::consumeError(s.takeError());
     Reset();
   } else {
-    PythonObject::Reset(std::move(s.get()));
+    *this = std::move(s.get());
   }
 }
 
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.h b/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.h
index 7f460234ffbf..5823f740a530 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.h
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.h
@@ -182,7 +182,8 @@ public:
     Reset(type, py_obj);
   }
 
-  PythonObject(const PythonObject &rhs) : m_py_obj(nullptr) { Reset(rhs); }
+  PythonObject(const PythonObject &rhs)
+      : PythonObject(PyRefType::Borrowed, rhs.m_py_obj) {}
 
   PythonObject(PythonObject &&rhs) {
     m_py_obj = rhs.m_py_obj;
@@ -197,19 +198,6 @@ public:
     m_py_obj = nullptr;
   }
 
-  void Reset(const PythonObject &rhs) {
-    if (!rhs.IsValid())
-      Reset();
-    else
-      Reset(PyRefType::Borrowed, rhs.m_py_obj);
-  }
-
-  // PythonObject is implicitly convertible to PyObject *, which will call the
-  // wrong overload.  We want to explicitly disallow this, since a PyObject
-  // *always* owns its reference.  Therefore the overload which takes a
-  // PyRefType doesn't make sense, and the copy constructor should be used.
-  void Reset(PyRefType type, const PythonObject &ref) = delete;
-
   void Reset(PyRefType type, PyObject *py_obj) {
     if (py_obj == m_py_obj)
       return;
@@ -244,19 +232,9 @@ public:
     return result;
   }
 
-  PythonObject &operator=(const PythonObject &other) {
-    Reset(PyRefType::Borrowed, other.get());
-    return *this;
-  }
-
-  void Reset(PythonObject &&other) {
+  PythonObject &operator=(PythonObject other) {
     Reset();
-    m_py_obj = other.m_py_obj;
-    other.m_py_obj = nullptr;
-  }
-
-  PythonObject &operator=(PythonObject &&other) {
-    Reset(std::move(other));
+    m_py_obj = std::exchange(other.m_py_obj, nullptr);
     return *this;
   }
 
diff --git a/lldb/unittests/ScriptInterpreter/Python/PythonDataObjectsTests.cpp b/lldb/unittests/ScriptInterpreter/Python/PythonDataObjectsTests.cpp
index 3f0cb78b64cc..d9e4435bf93e 100644
--- a/lldb/unittests/ScriptInterpreter/Python/PythonDataObjectsTests.cpp
+++ b/lldb/unittests/ScriptInterpreter/Python/PythonDataObjectsTests.cpp
@@ -323,8 +323,8 @@ TEST_F(PythonDataObjectsTest, TestPythonListValueEquality) {
   PythonList list(PyRefType::Owned, py_list);
 
   PythonObject list_items[list_size];
-  list_items[0].Reset(PythonInteger(long_value0));
-  list_items[1].Reset(PythonString(string_value1));
+  list_items[0] = PythonInteger(long_value0);
+  list_items[1] = PythonString(string_value1);
 
   for (unsigned i = 0; i < list_size; ++i)
     list.SetItemAtIndex(i, list_items[i]);
@@ -469,10 +469,10 @@ TEST_F(PythonDataObjectsTest, TestPythonDictionaryValueEquality) {
   PythonObject py_keys[dict_entries];
   PythonObject py_values[dict_entries];
 
-  py_keys[0].Reset(PythonString(key_0));
-  py_keys[1].Reset(PythonInteger(key_1));
-  py_values[0].Reset(PythonInteger(value_0));
-  py_values[1].Reset(PythonString(value_1));
+  py_keys[0] = PythonString(key_0);
+  py_keys[1] = PythonInteger(key_1);
+  py_values[0] = PythonInteger(value_0);
+  py_values[1] = PythonString(value_1);
 
   PyObject *py_dict = PyDict_New();
   EXPECT_TRUE(PythonDictionary::Check(py_dict));
@@ -509,10 +509,10 @@ TEST_F(PythonDataObjectsTest, TestPythonDictionaryManipulation) {
   PythonString keys[dict_entries];
   PythonObject values[dict_entries];
 
-  keys[0].Reset(PythonString(key_0));
-  keys[1].Reset(PythonString(key_1));
-  values[0].Reset(PythonInteger(value_0));
-  values[1].Reset(PythonString(value_1));
+  keys[0] = PythonString(key_0);
+  keys[1] = PythonString(key_1);
+  values[0] = PythonInteger(value_0);
+  values[1] = PythonString(value_1);
 
   PythonDictionary dict(PyInitialValue::Empty);
   for (int i = 0; i < 2; ++i)