[External] [stdlib] Use UnsafePointer in _cpython.mojo (#38798)

[External] [stdlib] Use `UnsafePointer` in `_cpython.mojo`

Co-authored-by: gabrieldemarmiesse <gabrieldemarmiesse@gmail.com>
Closes #2405
MODULAR_ORIG_COMMIT_REV_ID: 44ed3e851362efb44f26ef7fd44cacfa0a137a80

stdlib/src/python/_cpython.mojo

@@ -15,7 +15,7 @@ from os import getenv
 from sys import external_call
 from sys.ffi import DLHandle
 
-from memory import DTypePointer, LegacyPointer
+from memory import DTypePointer, UnsafePointer
 
 from utils import StringRef, StaticIntTuple
 
@@ -156,7 +156,7 @@ struct CPython:
     var dict_type: PyObjectPtr
     var logging_enabled: Bool
     var version: PythonVersion
-    var total_ref_count: LegacyPointer[Int]
+    var total_ref_count: UnsafePointer[Int]
 
     fn __init__(inout self: CPython):
         var logging_enabled = getenv("MODULAR_CPYTHON_LOGGING") == "ON"
@@ -172,7 +172,7 @@ struct CPython:
         var null_pointer = DTypePointer[DType.int8].get_null()
 
         self.lib = DLHandle(python_lib)
-        self.total_ref_count = LegacyPointer[Int].alloc(1)
+        self.total_ref_count = UnsafePointer[Int].alloc(1)
         self.none_value = PyObjectPtr(null_pointer)
         self.dict_type = PyObjectPtr(null_pointer)
         self.logging_enabled = logging_enabled
@@ -187,7 +187,12 @@ struct CPython:
         existing.Py_DecRef(existing.none_value)
         if existing.logging_enabled:
             print("CPython destroy")
-            print("Number of remaining refs:", existing.total_ref_count.load())
+            var remaining_refs = move_from_pointee(existing.total_ref_count)
+            print("Number of remaining refs:", remaining_refs)
+            # Technically not necessary since we're working with register
+            # passable types, by it's good practice to re-initialize the
+            # pointer after a consuming move.
+            initialize_pointee_move(existing.total_ref_count, remaining_refs)
         _py_finalize(existing.lib)
         existing.lib.close()
         existing.total_ref_count.free()
@@ -217,12 +222,12 @@ struct CPython:
         self.total_ref_count = existing.total_ref_count
 
     fn _inc_total_rc(inout self):
-        var v = self.total_ref_count.load()
-        self.total_ref_count[0] = v + 1
+        var v = move_from_pointee(self.total_ref_count)
+        initialize_pointee_move(self.total_ref_count, v + 1)
 
     fn _dec_total_rc(inout self):
-        var v = self.total_ref_count.load()
-        self.total_ref_count[0] = v - 1
+        var v = move_from_pointee(self.total_ref_count)
+        initialize_pointee_move(self.total_ref_count, v - 1)
 
     fn Py_IncRef(inout self, ptr: PyObjectPtr):
         if self.logging_enabled:
@@ -772,15 +777,15 @@ struct CPython:
         var key = DTypePointer[DType.int8].get_null()
         var value = DTypePointer[DType.int8].get_null()
         var v = p
-        var position = LegacyPointer[Int].address_of(v)
+        var position = UnsafePointer[Int].address_of(v)
         var value_ptr = UnsafePointer[DTypePointer[DType.int8]].address_of(
             value
         )
         var key_ptr = UnsafePointer[DTypePointer[DType.int8]].address_of(key)
         var result = self.lib.get_function[
             fn (
                 PyObjectPtr,
-                LegacyPointer[Int],
+                UnsafePointer[Int],
                 UnsafePointer[DTypePointer[DType.int8]],
                 UnsafePointer[DTypePointer[DType.int8]],
             ) -> Int
@@ -809,6 +814,6 @@ struct CPython:
         return PyKeyValuePair {
             key: key,
             value: value,
-            position: position.load(),
+            position: move_from_pointee(position),
             success: result == 1,
         }