add allow type alias bounds automatically

Author: gui1117

frame/support/procedural/src/pallet/expand/storage.rs

@@ -39,6 +39,7 @@ pub fn expand_storages(def: &mut Def) -> proc_macro2::TokenStream {
 		.collect::<Vec<_>>();
 
 	// Replace first arg `_` by the generated prefix structure.
+	// Add `#[allow(type_alias_bounds)]`
 	for (i, def_storage) in def.storages.iter_mut().enumerate() {
 		let item = &mut def.item.content.as_mut().expect("Checked by def").1[def_storage.index];
 
@@ -48,6 +49,8 @@ pub fn expand_storages(def: &mut Def) -> proc_macro2::TokenStream {
 			unreachable!("Checked by def");
 		};
 
+		typ_item.attrs.push(syn::parse_quote!(#[allow(type_alias_bounds)]));
+
 		let typ_path = if let syn::Type::Path(p) = &mut *typ_item.ty {
 			p
 		} else {

frame/support/src/lib.rs

@@ -1225,7 +1225,7 @@ pub mod pallet_prelude {
 /// 	//
 /// 	// NOTE: for storage hasher, the type is not copied because storage hasher trait already
 /// 	// implements metadata. Thus generic storage hasher is supported.
-/// 	#[pallet::storage] #[allow(type_alias_bounds)]
+/// 	#[pallet::storage]
 /// 	type MyStorageValue<T: Trait> = StorageValueType<_, T::Balance, ValueQuery>;
 ///
 /// 	// Another declaration
@@ -1351,7 +1351,7 @@ pub mod pallet_prelude {
 /// 		Something(u32),
 /// 	}
 ///
-/// 	#[pallet::storage] #[allow(type_alias_bounds)]
+/// 	#[pallet::storage]
 /// 	type MyStorageValue<T: Trait<I>, I: Instance = DefaultInstance> =
 /// 		StorageValueType<_, T::Balance, ValueQuery>;
 ///

frame/support/test/tests/pallet.rs

@@ -95,52 +95,26 @@ pub mod pallet {
 		Something(u32),
 	}
 
-	// Declare a storage, any amount of storage can be declared.
-	//
-	// Is expected either `StorageValueType`, `StorageMapType` or `StorageDoubleMapType`.
-	// The macro generates for struct `$identP` (for storage of name `$ident`) and implement
-	// storage instance on it.
-	// The macro macro expand the metadata for the storage with the type used:
-	// * For storage value the type for value will be copied into metadata
-	// * For storage map the type for value and the type for key will be copied into metadata
-	// * For storage double map the type for value, key1, and key2 will be copied into
-	//   metadata.
-	//
-	// NOTE: for storage hasher, the type is not copied because storage hasher trait already
-	// implements metadata. Thus generic storage hasher is supported.
-	#[pallet::storage] #[allow(type_alias_bounds)]
-	type MyStorageValue<T: Trait> = StorageValueType<MyStorageValueP, T::Balance, ValueQuery>;
+	#[pallet::storage]
+	type MyStorageValue<T: Trait> = StorageValueType<_, T::Balance, ValueQuery>;
 
-	// Another declaration
 	#[pallet::storage]
-	type MyStorage = StorageMapType<MyStorageP, Blake2_128Concat, u32, u32>;
+	type MyStorage = StorageMapType<_, Blake2_128Concat, u32, u32>;
 
-	// Declare genesis config. (This is optional)
-	//
-	// The macro accept either type alias or struct or enum, it checks generics are consistent.
-	//
-	// Type must implement `Default` traits
 	#[pallet::genesis_config]
 	#[derive(Default)]
 	pub struct GenesisConfig {
 		_myfield: u32,
 	}
 
-	// Declare genesis builder. (This is need only if GenesisConfig is declared)
 	#[pallet::genesis_build]
 	impl<T: Trait> GenesisBuilder<T> for GenesisConfig {
 		fn build(&self) {}
 	}
 
-	// Declare a pallet origin. (this is optional)
-	//
-	// The macro accept type alias or struct or enum, it checks generics are consistent.
 	#[pallet::origin]
 	pub struct Origin<T>(PhantomData<T>);
 
-	// Declare inherent provider for module. (this is optional)
-	//
-	// The macro checks module is `Module<T>` or `Module<T, I>` and trait is `ProvideInherent`
 	#[pallet::inherent]
 	impl<T: Trait> ProvideInherent for Module<T> {
 		type Call = Call<T>;
@@ -153,8 +127,6 @@ pub mod pallet {
 		}
 	}
 
-	// Regular rust code needed for implementing ProvideInherent trait
-
 	#[derive(codec::Encode, sp_runtime::RuntimeDebug)]
 	#[cfg_attr(feature = "std", derive(codec::Decode))]
 	pub enum InherentError {

frame/support/test/tests/pallet_compatibility.rs

@@ -120,22 +120,22 @@ pub mod pallet {
 		Dummy(T::Balance),
 	}
 
-	#[pallet::storage] #[allow(type_alias_bounds)]
+	#[pallet::storage]
 	/// Some documentation
 	type Dummy<T: Trait> = StorageValueType<_, T::Balance, OptionQuery>;
 
-	#[pallet::storage] #[allow(type_alias_bounds)]
+	#[pallet::storage]
 	type Bar<T: Trait> = StorageMapType<_, Blake2_128Concat, T::AccountId, T::Balance, ValueQuery>;
 
-	#[pallet::storage] #[allow(type_alias_bounds)]
+	#[pallet::storage]
 	type Foo<T: Trait> = StorageValueType<_, T::Balance, ValueQuery, OnFooEmpty<T>>;
 	pub struct OnFooEmpty<T: Trait>(PhantomData<T>); // TODO TODO: allow faster declaration with parameter_types
 	impl<T: Trait> Get<T::Balance> for OnFooEmpty<T> { fn get() -> T::Balance { 3.into() } }
 	// #[pallet::type_value] pub struct BalanceDefault: Balance = 0;
 	// #[pallet::type_value] pub fn BalanceDefault<T: Trait>() -> T::Balance { 0.into() }
 	// #[pallet::type_value] pub struct BalanceDefault<T: Trait>(fn() -> T::Balance { 0.into() })
 
-	#[pallet::storage] #[allow(type_alias_bounds)]
+	#[pallet::storage]
 	type Double = StorageDoubleMapType<
 		_, Blake2_128Concat, u32, Twox64Concat, u64, u16, ValueQuery
 	>;

frame/support/test/tests/pallet_compatibility_instance.rs

@@ -118,21 +118,21 @@ pub mod pallet {
 		Dummy(T::Balance),
 	}
 
-	#[pallet::storage] #[allow(type_alias_bounds)]
+	#[pallet::storage]
 	/// Some documentation
 	type Dummy<T: Trait<I>, I: Instance = DefaultInstance> = StorageValueType<_, T::Balance, OptionQuery>;
 
-	#[pallet::storage] #[allow(type_alias_bounds)]
+	#[pallet::storage]
 	type Bar<T: Trait<I>, I: Instance = DefaultInstance> =
 		StorageMapType<_, Blake2_128Concat, T::AccountId, T::Balance, ValueQuery>;
 
-	#[pallet::storage] #[allow(type_alias_bounds)]
+	#[pallet::storage]
 	type Foo<T: Trait<I>, I: Instance = DefaultInstance> =
 		StorageValueType<_, T::Balance, ValueQuery, OnFooEmpty<T, I>>;
 	pub struct OnFooEmpty<T: Trait<I>, I: Instance>(PhantomData<(T, I)>);
 	impl<T: Trait<I>, I: Instance> Get<T::Balance> for OnFooEmpty<T, I> { fn get() -> T::Balance { 3.into() } }
 
-	#[pallet::storage] #[allow(type_alias_bounds)]
+	#[pallet::storage]
 	type Double<I: Instance = DefaultInstance> = StorageDoubleMapType<
 		_, Blake2_128Concat, u32, Twox64Concat, u64, u16, ValueQuery
 	>;