Enable readability-redundant-declaration (#143982)

Fixes #ISSUE_NUMBER

Pull Request resolved: https://github.com/pytorch/pytorch/pull/143982
Approved by: https://github.com/Skylion007

.clang-tidy

@@ -60,7 +60,6 @@ readability-simplify-subscript-expr,
 readability-string-compare,
 -readability-redundant-access-specifiers,
 -readability-redundant-control-flow,
--readability-redundant-declaration,
 '
 HeaderFilterRegex: '^(aten/|c10/|torch/).*$'
 WarningsAsErrors: '*'

c10/core/TensorOptions.h

@@ -23,11 +23,6 @@
 
 namespace c10 {
 
-DispatchKey computeDispatchKey(
-    std::optional<ScalarType> dtype,
-    std::optional<Layout> layout,
-    std::optional<Device> device);
-
 inline ScalarType dtype_or_default(std::optional<ScalarType> dtype) {
   return dtype.value_or(get_default_dtype_as_scalartype());
 }

torch/csrc/Size.cpp

@@ -149,8 +149,6 @@ static PyObject* THPSize_repr(THPSize* self) {
   END_HANDLE_TH_ERRORS
 }
 
-extern PyTypeObject THPSizeType;
-
 template <typename FnType, FnType fn, typename... Args>
 static PyObject* wrap_tuple_fn(Args... args) {
   THPObjectPtr result((*fn)(std::forward<Args>(args)...));

torch/csrc/utils/python_compat.h

@@ -34,6 +34,7 @@ static inline int PyCode_GetNFreevars(PyCodeObject* code) {
 
 // Provided by CPython but getting the header for them is very hard
 #if IS_PYTHON_3_11_PLUS
+// NOLINTNEXTLINE(readability-redundant-declaration)
 PyAPI_FUNC(void) _PyWeakref_ClearRef(PyWeakReference* self);
 #else
 extern void _PyWeakref_ClearRef(PyWeakReference* self);

torch/custom_class_detail.h

@@ -227,6 +227,7 @@ TORCH_API at::ClassTypePtr getCustomClass(const std::string& name);
 
 // Given an IValue, return true if the object contained in that IValue
 // is a custom C++ class, otherwise return false.
+// NOLINTNEXTLINE(readability-redundant-declaration)
 TORCH_API bool isCustomClass(const c10::IValue& v);
 
 // This API is for testing purposes ONLY. It should not be used in