generate_storage_alias: Rewrite as proc macro attribute (paritytech#1…

…1387)

* generate_storage_alias: Rewrite as proc macro attribute

This rewrites the `generate_storage_alias!` declarative macro as proc-macro attribute. While doing
this the name is changed to `storage_alias`. The prefix can now also be the name of a pallet. This
makes storage aliases work in migrations for all kind of chains and not just for the ones that use
predefined prefixes.

* Fix compilation and FMT

* Moare fixes

* 🤦

* ......

* Rework the syntax and support instancing

* FMT

* Prefix variants with `Storage`

* Make it compile

* Fix where clause on rust stable

frame/bags-list/src/list/tests.rs

@@ -368,12 +368,10 @@ mod list {
 			assert_eq!(crate::ListNodes::<Runtime>::count(), 4);
 			// we do some wacky stuff here to get access to the counter, since it is (reasonably)
 			// not exposed as mutable in any sense.
-			frame_support::generate_storage_alias!(
-				BagsList,
-				CounterForListNodes
-				=> Value<u32, frame_support::pallet_prelude::ValueQuery>
-			);
-			CounterForListNodes::mutate(|counter| *counter += 1);
+			#[frame_support::storage_alias]
+			type CounterForListNodes<T: Config> =
+				StorageValue<crate::Pallet<T>, u32, frame_support::pallet_prelude::ValueQuery>;
+			CounterForListNodes::<Runtime>::mutate(|counter| *counter += 1);
 			assert_eq!(crate::ListNodes::<Runtime>::count(), 5);
 
 			assert_eq!(List::<Runtime>::sanity_check(), Err("iter_count != stored_count"));

frame/bags-list/src/migrations.rs

@@ -30,11 +30,12 @@ impl<T: crate::Config> OnRuntimeUpgrade for CheckCounterPrefix<T> {
 	fn pre_upgrade() -> Result<(), &'static str> {
 		use frame_support::ensure;
 		// The old explicit storage item.
-		frame_support::generate_storage_alias!(BagsList, CounterForListNodes => Value<u32>);
+		#[frame_support::storage_alias]
+		type CounterForListNodes<T: crate::Config> = StorageValue<crate::Pallet<T>, u32>;
 
 		// ensure that a value exists in the counter struct.
 		ensure!(
-			crate::ListNodes::<T>::count() == CounterForListNodes::get().unwrap(),
+			crate::ListNodes::<T>::count() == CounterForListNodes::<T>::get().unwrap(),
 			"wrong list node counter"
 		);
 

frame/contracts/src/migration.rs

@@ -18,11 +18,8 @@
 use crate::{BalanceOf, CodeHash, Config, Pallet, TrieId, Weight};
 use codec::{Decode, Encode};
 use frame_support::{
-	codec, generate_storage_alias,
-	pallet_prelude::*,
-	storage::migration,
-	traits::{Get, PalletInfoAccess},
-	Identity, Twox64Concat,
+	codec, pallet_prelude::*, storage::migration, storage_alias, traits::Get, Identity,
+	Twox64Concat,
 };
 use sp_std::{marker::PhantomData, prelude::*};
 
@@ -117,15 +114,16 @@ mod v5 {
 		trie_id: TrieId,
 	}
 
-	generate_storage_alias!(
-		Contracts,
-		ContractInfoOf<T: Config> => Map<(Twox64Concat, T::AccountId), ContractInfo<T>>
-	);
+	#[storage_alias]
+	type ContractInfoOf<T: Config> = StorageMap<
+		Pallet<T>,
+		Twox64Concat,
+		<T as frame_system::Config>::AccountId,
+		ContractInfo<T>,
+	>;
 
-	generate_storage_alias!(
-		Contracts,
-		DeletionQueue => Value<Vec<DeletedContract>>
-	);
+	#[storage_alias]
+	type DeletionQueue<T: Config> = StorageValue<Pallet<T>, Vec<DeletedContract>>;
 
 	pub fn migrate<T: Config>() -> Weight {
 		let mut weight: Weight = 0;
@@ -142,7 +140,7 @@ mod v5 {
 			}
 		});
 
-		DeletionQueue::translate(|old: Option<Vec<OldDeletedContract>>| {
+		DeletionQueue::<T>::translate(|old: Option<Vec<OldDeletedContract>>| {
 			weight = weight.saturating_add(T::DbWeight::get().reads_writes(1, 1));
 			old.map(|old| old.into_iter().map(|o| DeletedContract { trie_id: o.trie_id }).collect())
 		})
@@ -202,20 +200,19 @@ mod v6 {
 
 	type ContractInfo<T> = RawContractInfo<CodeHash<T>, BalanceOf<T>>;
 
-	generate_storage_alias!(
-		Contracts,
-		ContractInfoOf<T: Config> => Map<(Twox64Concat, T::AccountId), ContractInfo<T>>
-	);
+	#[storage_alias]
+	type ContractInfoOf<T: Config> = StorageMap<
+		Pallet<T>,
+		Twox64Concat,
+		<T as frame_system::Config>::AccountId,
+		ContractInfo<T>,
+	>;
 
-	generate_storage_alias!(
-		Contracts,
-		CodeStorage<T: Config> => Map<(Identity, CodeHash<T>), PrefabWasmModule>
-	);
+	#[storage_alias]
+	type CodeStorage<T: Config> = StorageMap<Pallet<T>, Identity, CodeHash<T>, PrefabWasmModule>;
 
-	generate_storage_alias!(
-		Contracts,
-		OwnerInfoOf<T: Config> => Map<(Identity, CodeHash<T>), OwnerInfo<T>>
-	);
+	#[storage_alias]
+	type OwnerInfoOf<T: Config> = StorageMap<Pallet<T>, Identity, CodeHash<T>, OwnerInfo<T>>;
 
 	pub fn migrate<T: Config>() -> Weight {
 		let mut weight: Weight = 0;
@@ -259,15 +256,12 @@ mod v7 {
 	use super::*;
 
 	pub fn migrate<T: Config>() -> Weight {
-		generate_storage_alias!(
-			Contracts,
-			AccountCounter => Value<u64, ValueQuery>
-		);
-		generate_storage_alias!(
-			Contracts,
-			Nonce => Value<u64, ValueQuery>
-		);
-		Nonce::set(AccountCounter::take());
+		#[storage_alias]
+		type AccountCounter<T: Config> = StorageValue<Pallet<T>, u64, ValueQuery>;
+		#[storage_alias]
+		type Nonce<T: Config> = StorageValue<Pallet<T>, u64, ValueQuery>;
+
+		Nonce::<T>::set(AccountCounter::<T>::take());
 		T::DbWeight::get().reads_writes(1, 2)
 	}
 }

frame/elections-phragmen/src/migrations/v3.rs

@@ -17,12 +17,10 @@
 
 //! Migrations to version [`3.0.0`], as denoted by the changelog.
 
+use crate::{Config, Pallet};
 use codec::{Decode, Encode, FullCodec};
 use frame_support::{
-	pallet_prelude::ValueQuery,
-	traits::{PalletInfoAccess, StorageVersion},
-	weights::Weight,
-	RuntimeDebug, Twox64Concat,
+	pallet_prelude::ValueQuery, traits::StorageVersion, weights::Weight, RuntimeDebug, Twox64Concat,
 };
 use sp_std::prelude::*;
 
@@ -42,40 +40,38 @@ struct Voter<AccountId, Balance> {
 
 /// Trait to implement to give information about types used for migration
 pub trait V2ToV3 {
-	/// The elections-phragmen pallet.
-	type Pallet: 'static + PalletInfoAccess;
-
 	/// System config account id
 	type AccountId: 'static + FullCodec;
 
 	/// Elections-phragmen currency balance.
 	type Balance: 'static + FullCodec + Copy;
 }
 
-frame_support::generate_storage_alias!(
-	PhragmenElection, Candidates<T: V2ToV3> => Value<
-		Vec<(T::AccountId, T::Balance)>,
-		ValueQuery
-	>
-);
-frame_support::generate_storage_alias!(
-	PhragmenElection, Members<T: V2ToV3> => Value<
-		Vec<SeatHolder<T::AccountId, T::Balance>>,
-		ValueQuery
-	>
-);
-frame_support::generate_storage_alias!(
-	PhragmenElection, RunnersUp<T: V2ToV3> => Value<
-		Vec<SeatHolder<T::AccountId, T::Balance>>,
-		ValueQuery
-	>
-);
-frame_support::generate_storage_alias!(
-	PhragmenElection, Voting<T: V2ToV3> => Map<
-		(Twox64Concat, T::AccountId),
-		Voter<T::AccountId, T::Balance>
-	>
-);
+#[frame_support::storage_alias]
+type Candidates<V, T: Config> =
+	StorageValue<Pallet<T>, Vec<(<V as V2ToV3>::AccountId, <V as V2ToV3>::Balance)>, ValueQuery>;
+
+#[frame_support::storage_alias]
+type Members<V, T: Config> = StorageValue<
+	Pallet<T>,
+	Vec<SeatHolder<<V as V2ToV3>::AccountId, <V as V2ToV3>::Balance>>,
+	ValueQuery,
+>;
+
+#[frame_support::storage_alias]
+type RunnersUp<V, T: Config> = StorageValue<
+	Pallet<T>,
+	Vec<SeatHolder<<V as V2ToV3>::AccountId, <V as V2ToV3>::Balance>>,
+	ValueQuery,
+>;
+
+#[frame_support::storage_alias]
+type Voting<V, T: Config> = StorageMap<
+	Pallet<T>,
+	Twox64Concat,
+	<V as V2ToV3>::AccountId,
+	Voter<<V as V2ToV3>::AccountId, <V as V2ToV3>::Balance>,
+>;
 
 /// Apply all of the migrations from 2 to 3.
 ///
@@ -86,21 +82,24 @@ frame_support::generate_storage_alias!(
 ///
 /// Be aware that this migration is intended to be used only for the mentioned versions. Use
 /// with care and run at your own risk.
-pub fn apply<T: V2ToV3>(old_voter_bond: T::Balance, old_candidacy_bond: T::Balance) -> Weight {
-	let storage_version = StorageVersion::get::<T::Pallet>();
+pub fn apply<V: V2ToV3, T: Config>(
+	old_voter_bond: V::Balance,
+	old_candidacy_bond: V::Balance,
+) -> Weight {
+	let storage_version = StorageVersion::get::<Pallet<T>>();
 	log::info!(
 		target: "runtime::elections-phragmen",
 		"Running migration for elections-phragmen with storage version {:?}",
 		storage_version,
 	);
 
 	if storage_version <= 2 {
-		migrate_voters_to_recorded_deposit::<T>(old_voter_bond);
-		migrate_candidates_to_recorded_deposit::<T>(old_candidacy_bond);
-		migrate_runners_up_to_recorded_deposit::<T>(old_candidacy_bond);
-		migrate_members_to_recorded_deposit::<T>(old_candidacy_bond);
+		migrate_voters_to_recorded_deposit::<V, T>(old_voter_bond);
+		migrate_candidates_to_recorded_deposit::<V, T>(old_candidacy_bond);
+		migrate_runners_up_to_recorded_deposit::<V, T>(old_candidacy_bond);
+		migrate_members_to_recorded_deposit::<V, T>(old_candidacy_bond);
 
-		StorageVersion::new(3).put::<T::Pallet>();
+		StorageVersion::new(3).put::<Pallet<T>>();
 
 		Weight::max_value()
 	} else {
@@ -114,21 +113,21 @@ pub fn apply<T: V2ToV3>(old_voter_bond: T::Balance, old_candidacy_bond: T::Balan
 }
 
 /// Migrate from the old legacy voting bond (fixed) to the new one (per-vote dynamic).
-pub fn migrate_voters_to_recorded_deposit<T: V2ToV3>(old_deposit: T::Balance) {
-	<Voting<T>>::translate::<(T::Balance, Vec<T::AccountId>), _>(|_who, (stake, votes)| {
+pub fn migrate_voters_to_recorded_deposit<V: V2ToV3, T: Config>(old_deposit: V::Balance) {
+	<Voting<V, T>>::translate::<(V::Balance, Vec<V::AccountId>), _>(|_who, (stake, votes)| {
 		Some(Voter { votes, stake, deposit: old_deposit })
 	});
 
 	log::info!(
 		target: "runtime::elections-phragmen",
 		"migrated {} voter accounts.",
-		<Voting<T>>::iter().count(),
+		<Voting<V, T>>::iter().count(),
 	);
 }
 
 /// Migrate all candidates to recorded deposit.
-pub fn migrate_candidates_to_recorded_deposit<T: V2ToV3>(old_deposit: T::Balance) {
-	let _ = <Candidates<T>>::translate::<Vec<T::AccountId>, _>(|maybe_old_candidates| {
+pub fn migrate_candidates_to_recorded_deposit<V: V2ToV3, T: Config>(old_deposit: V::Balance) {
+	let _ = <Candidates<V, T>>::translate::<Vec<V::AccountId>, _>(|maybe_old_candidates| {
 		maybe_old_candidates.map(|old_candidates| {
 			log::info!(
 				target: "runtime::elections-phragmen",
@@ -141,8 +140,8 @@ pub fn migrate_candidates_to_recorded_deposit<T: V2ToV3>(old_deposit: T::Balance
 }
 
 /// Migrate all members to recorded deposit.
-pub fn migrate_members_to_recorded_deposit<T: V2ToV3>(old_deposit: T::Balance) {
-	let _ = <Members<T>>::translate::<Vec<(T::AccountId, T::Balance)>, _>(|maybe_old_members| {
+pub fn migrate_members_to_recorded_deposit<V: V2ToV3, T: Config>(old_deposit: V::Balance) {
+	let _ = <Members<V, T>>::translate::<Vec<(V::AccountId, V::Balance)>, _>(|maybe_old_members| {
 		maybe_old_members.map(|old_members| {
 			log::info!(
 				target: "runtime::elections-phragmen",
@@ -158,9 +157,9 @@ pub fn migrate_members_to_recorded_deposit<T: V2ToV3>(old_deposit: T::Balance) {
 }
 
 /// Migrate all runners-up to recorded deposit.
-pub fn migrate_runners_up_to_recorded_deposit<T: V2ToV3>(old_deposit: T::Balance) {
-	let _ =
-		<RunnersUp<T>>::translate::<Vec<(T::AccountId, T::Balance)>, _>(|maybe_old_runners_up| {
+pub fn migrate_runners_up_to_recorded_deposit<V: V2ToV3, T: Config>(old_deposit: V::Balance) {
+	let _ = <RunnersUp<V, T>>::translate::<Vec<(V::AccountId, V::Balance)>, _>(
+		|maybe_old_runners_up| {
 			maybe_old_runners_up.map(|old_runners_up| {
 				log::info!(
 					target: "runtime::elections-phragmen",
@@ -172,5 +171,6 @@ pub fn migrate_runners_up_to_recorded_deposit<T: V2ToV3>(old_deposit: T::Balance
 					.map(|(who, stake)| SeatHolder { who, stake, deposit: old_deposit })
 					.collect::<Vec<_>>()
 			})
-		});
+		},
+	);
 }

frame/offences/src/migration.rs

@@ -16,9 +16,7 @@
 // limitations under the License.
 
 use super::{Config, OffenceDetails, Perbill, SessionIndex};
-use frame_support::{
-	generate_storage_alias, pallet_prelude::ValueQuery, traits::Get, weights::Weight,
-};
+use frame_support::{pallet_prelude::ValueQuery, storage_alias, traits::Get, weights::Weight};
 use sp_staking::offence::{DisableStrategy, OnOffenceHandler};
 use sp_std::vec::Vec;
 
@@ -31,10 +29,9 @@ type DeferredOffenceOf<T> = (
 
 // Deferred reports that have been rejected by the offence handler and need to be submitted
 // at a later time.
-generate_storage_alias!(
-	Offences,
-	DeferredOffences<T: Config> => Value<Vec<DeferredOffenceOf<T>>, ValueQuery>
-);
+#[storage_alias]
+type DeferredOffences<T: Config> =
+	StorageValue<crate::Pallet<T>, Vec<DeferredOffenceOf<T>>, ValueQuery>;
 
 pub fn remove_deferred_storage<T: Config>() -> Weight {
 	let mut weight = T::DbWeight::get().reads_writes(1, 1);