Allow renaming storage item prefixes (#9016)

* Implement parsing for #[pallet::storage_name] on storage items

* Rename storage prefix when a #[pallet::storage_name] is supplied

* Fix test_storage_info

* Rename storage_name to storage_prefix

* Check for duplicates when renaming storage prefixes

* Allow only string literals for storage_prefix renames

* Use proper spans for attribute errors

* Check for valid identifiers when parsing storage prefix renames

substrate/frame/support/test/tests/pallet_ui/duplicate_storage_prefix.rs

@@ -0,0 +1,21 @@
+#[frame_support::pallet]
+mod pallet {
+	use frame_support::pallet_prelude::StorageValue;
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {}
+
+	#[pallet::pallet]
+	#[pallet::generate_store(trait Store)]
+	pub struct Pallet<T>(core::marker::PhantomData<T>);
+
+	#[pallet::storage]
+	type Foo<T> = StorageValue<_, u8>;
+
+    #[pallet::storage]
+    #[pallet::storage_prefix = "Foo"]
+    type NotFoo<T> = StorageValue<_, u16>;
+}
+
+fn main() {
+}

substrate/frame/support/test/tests/pallet_ui/duplicate_storage_prefix.stderr

@@ -0,0 +1,17 @@
+error: Duplicate storage prefixes found for `Foo`
+  --> $DIR/duplicate_storage_prefix.rs:16:32
+   |
+16 |     #[pallet::storage_prefix = "Foo"]
+   |                                ^^^^^
+
+error[E0412]: cannot find type `_GeneratedPrefixForStorageFoo` in this scope
+  --> $DIR/duplicate_storage_prefix.rs:13:7
+   |
+13 |     type Foo<T> = StorageValue<_, u8>;
+   |          ^^^ not found in this scope
+
+error[E0121]: the type placeholder `_` is not allowed within types on item signatures
+  --> $DIR/duplicate_storage_prefix.rs:17:35
+   |
+17 |     type NotFoo<T> = StorageValue<_, u16>;
+   |                                   ^ not allowed in type signatures

substrate/frame/support/test/tests/pallet_ui/storage_invalid_attribute.rs

@@ -0,0 +1,21 @@
+#[frame_support::pallet]
+mod pallet {
+	use frame_support::pallet_prelude::Hooks;
+	use frame_system::pallet_prelude::BlockNumberFor;
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {}
+
+	#[pallet::storage]
+	#[pallet::generate_store(pub trait Store)]
+	type Foo<T> = StorageValue<u8, u8>;
+}
+
+fn main() {
+}

substrate/frame/support/test/tests/pallet_ui/storage_invalid_attribute.stderr

@@ -0,0 +1,5 @@
+error: expected `getter` or `storage_prefix`
+  --> $DIR/storage_invalid_attribute.rs:16:12
+   |
+16 |     #[pallet::generate_store(pub trait Store)]
+   |               ^^^^^^^^^^^^^^

substrate/frame/support/test/tests/pallet_ui/storage_invalid_rename_value.rs

@@ -0,0 +1,18 @@
+#[frame_support::pallet]
+mod pallet {
+	use frame_support::pallet_prelude::Hooks;
+	use frame_system::pallet_prelude::BlockNumberFor;
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(core::marker::PhantomData<T>);
+
+	#[pallet::storage]
+	#[pallet::storage_prefix = "pub"]
+	type Foo<T> = StorageValue<_, u8>;
+}
+
+fn main() {
+}

substrate/frame/support/test/tests/pallet_ui/storage_invalid_rename_value.stderr

@@ -0,0 +1,5 @@
+error: `pub` is not a valid identifier
+  --> $DIR/storage_invalid_rename_value.rs:13:29
+   |
+13 |     #[pallet::storage_prefix = "pub"]
+   |                                ^^^^^

substrate/frame/support/test/tests/pallet_ui/storage_multiple_getters.rs

@@ -0,0 +1,25 @@
+#[frame_support::pallet]
+mod pallet {
+	use frame_support::pallet_prelude::Hooks;
+	use frame_system::pallet_prelude::BlockNumberFor;
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(core::marker::PhantomData<T>);
+
+	#[pallet::hooks]
+	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {}
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {}
+
+	#[pallet::storage]
+	#[pallet::getter(fn get_foo)]
+	#[pallet::getter(fn foo_error)]
+	type Foo<T> = StorageValue<_, u8>;
+}
+
+fn main() {
+}

substrate/frame/support/test/tests/pallet_ui/storage_multiple_getters.stderr

@@ -0,0 +1,5 @@
+error: Invalid pallet::storage, multiple argument pallet::getter found
+  --> $DIR/storage_multiple_getters.rs:20:3
+   |
+20 |     #[pallet::getter(fn foo_error)]
+   |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

substrate/frame/support/test/tests/pallet_ui/storage_multiple_renames.rs

@@ -0,0 +1,25 @@
+#[frame_support::pallet]
+mod pallet {
+	use frame_support::pallet_prelude::Hooks;
+	use frame_system::pallet_prelude::BlockNumberFor;
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(core::marker::PhantomData<T>);
+
+	#[pallet::hooks]
+	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {}
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {}
+
+	#[pallet::storage]
+	#[pallet::storage_prefix = "Bar"]
+	#[pallet::storage_prefix = "Baz"]
+	type Foo<T> = StorageValue<_, u8>;
+}
+
+fn main() {
+}

substrate/frame/support/test/tests/pallet_ui/storage_multiple_renames.stderr

@@ -0,0 +1,5 @@
+error: Invalid pallet::storage, multiple argument pallet::storage_prefix found
+  --> $DIR/storage_multiple_renames.rs:20:3
+   |
+20 |     #[pallet::storage_prefix = "Baz"]
+   |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^