decl_module! macro: use 'frame_system' instead of system as default ident (#6500)

* Use frame_system as default ident.

* Remove unused 'frame_system' to 'system' renaming.

* Fix construct_runtime_ui tests.

* Rename system to frame_system in sudo/utility pallet test.

* Bump runtime impl_version.

* Update formatting.

substrate/bin/node-template/pallets/template/src/lib.rs

@@ -10,7 +10,7 @@
 /// https://github.com/paritytech/substrate/blob/master/frame/example/src/lib.rs
 
 use frame_support::{decl_module, decl_storage, decl_event, decl_error, dispatch};
-use frame_system::{self as system, ensure_signed};
+use frame_system::ensure_signed;
 
 #[cfg(test)]
 mod mock;
@@ -19,11 +19,11 @@ mod mock;
 mod tests;
 
 /// The pallet's configuration trait.
-pub trait Trait: system::Trait {
+pub trait Trait: frame_system::Trait {
 	// Add other types and constants required to configure this pallet.
 
 	/// The overarching event type.
-	type Event: From<Event<Self>> + Into<<Self as system::Trait>::Event>;
+	type Event: From<Event<Self>> + Into<<Self as frame_system::Trait>::Event>;
 }
 
 // This pallet's storage items.
@@ -41,7 +41,7 @@ decl_storage! {
 
 // The pallet's events
 decl_event!(
-	pub enum Event<T> where AccountId = <T as system::Trait>::AccountId {
+	pub enum Event<T> where AccountId = <T as frame_system::Trait>::AccountId {
 		/// Just a dummy event.
 		/// Event `Something` is declared with a parameter of the type `u32` and `AccountId`
 		/// To emit this event, we call the deposit function, from our runtime functions

substrate/bin/node/runtime/src/lib.rs

@@ -98,7 +98,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	// implementation changes and behavior does not, then leave spec_version as
 	// is and increment impl_version.
 	spec_version: 255,
-	impl_version: 0,
+	impl_version: 1,
 	apis: RUNTIME_API_VERSIONS,
 	transaction_version: 1,
 };

substrate/frame/assets/src/lib.rs

@@ -87,7 +87,7 @@
 //! ```rust,ignore
 //! use pallet_assets as assets;
 //! use frame_support::{decl_module, dispatch, ensure};
-//! use frame_system::{self as system, ensure_signed};
+//! use frame_system::ensure_signed;
 //!
 //! pub trait Trait: assets::Trait { }
 //!
@@ -135,7 +135,7 @@
 
 use frame_support::{Parameter, decl_module, decl_event, decl_storage, decl_error, ensure};
 use sp_runtime::traits::{Member, AtLeast32Bit, AtLeast32BitUnsigned, Zero, StaticLookup};
-use frame_system::{self as system, ensure_signed};
+use frame_system::ensure_signed;
 use sp_runtime::traits::One;
 
 /// The module configuration trait.

substrate/frame/contracts/src/lib.rs

@@ -112,7 +112,7 @@ use frame_support::{
 	dispatch::{DispatchResult, DispatchResultWithPostInfo},
 	traits::{OnUnbalanced, Currency, Get, Time, Randomness},
 };
-use frame_system::{self as system, ensure_signed, ensure_root};
+use frame_system::{ensure_signed, ensure_root};
 use pallet_contracts_primitives::{RentProjection, ContractAccessError};
 use frame_support::weights::Weight;
 

substrate/frame/elections-phragmen/src/lib.rs

@@ -101,7 +101,7 @@ use frame_support::{
 	}
 };
 use sp_npos_elections::{build_support_map, ExtendedBalance, VoteWeight, ElectionResult};
-use frame_system::{self as system, ensure_signed, ensure_root};
+use frame_system::{ensure_signed, ensure_root};
 
 mod benchmarking;
 
@@ -1060,7 +1060,6 @@ mod tests {
 		traits::{BlakeTwo256, IdentityLookup, Block as BlockT},
 	};
 	use crate as elections_phragmen;
-	use frame_system as system;
 
 	parameter_types! {
 		pub const BlockHashCount: u64 = 250;
@@ -1225,7 +1224,7 @@ mod tests {
 			NodeBlock = Block,
 			UncheckedExtrinsic = UncheckedExtrinsic
 		{
-			System: system::{Module, Call, Event<T>},
+			System: frame_system::{Module, Call, Event<T>},
 			Balances: pallet_balances::{Module, Call, Event<T>, Config<T>},
 			Elections: elections_phragmen::{Module, Call, Event<T>, Config<T>},
 		}

substrate/frame/elections/src/lib.rs

@@ -38,7 +38,7 @@ use frame_support::{
 	}
 };
 use codec::{Encode, Decode};
-use frame_system::{self as system, ensure_signed, ensure_root};
+use frame_system::{ensure_signed, ensure_root};
 
 mod mock;
 mod tests;

substrate/frame/evm/src/lib.rs

@@ -33,7 +33,7 @@ use serde::{Serialize, Deserialize};
 use frame_support::{ensure, decl_module, decl_storage, decl_event, decl_error};
 use frame_support::weights::Weight;
 use frame_support::traits::{Currency, WithdrawReason, ExistenceRequirement, Get};
-use frame_system::{self as system, ensure_signed};
+use frame_system::ensure_signed;
 use sp_runtime::ModuleId;
 use sp_core::{U256, H256, H160, Hasher};
 use sp_runtime::{

substrate/frame/example/src/lib.rs

@@ -260,7 +260,7 @@ use frame_support::{
 	weights::{DispatchClass, ClassifyDispatch, WeighData, Weight, PaysFee, Pays},
 };
 use sp_std::prelude::*;
-use frame_system::{self as system, ensure_signed, ensure_root};
+use frame_system::{ensure_signed, ensure_root};
 use codec::{Encode, Decode};
 use sp_runtime::{
 	traits::{

substrate/frame/generic-asset/src/lib.rs

@@ -171,7 +171,7 @@ use frame_support::{
 	},
 	Parameter, StorageMap,
 };
-use frame_system::{self as system, ensure_signed, ensure_root};
+use frame_system::{ensure_signed, ensure_root};
 
 mod mock;
 mod tests;

substrate/frame/grandpa/src/lib.rs

@@ -43,7 +43,7 @@ use frame_support::{
 	decl_error, decl_event, decl_module, decl_storage, storage, traits::KeyOwnerProofSystem,
 	Parameter,
 };
-use frame_system::{self as system, ensure_signed, DigestOf};
+use frame_system::{ensure_signed, DigestOf};
 use sp_runtime::{
 	generic::{DigestItem, OpaqueDigestItemId},
 	traits::Zero,

substrate/frame/identity/src/lib.rs

@@ -78,7 +78,7 @@ use frame_support::{
 	traits::{Currency, ReservableCurrency, OnUnbalanced, Get, BalanceStatus, EnsureOrigin},
 	weights::Weight,
 };
-use frame_system::{self as system, ensure_signed};
+use frame_system::ensure_signed;
 
 mod benchmarking;
 

substrate/frame/im-online/src/lib.rs

@@ -44,7 +44,7 @@
 //!
 //! ```
 //! use frame_support::{decl_module, dispatch};
-//! use frame_system::{self as system, ensure_signed};
+//! use frame_system::ensure_signed;
 //! use pallet_im_online::{self as im_online};
 //!
 //! pub trait Trait: im_online::Trait {}
@@ -97,7 +97,7 @@ use frame_support::{
 	traits::Get,
 	weights::Weight,
 };
-use frame_system::{self as system, ensure_none};
+use frame_system::ensure_none;
 use frame_system::offchain::{
 	SendTransactionTypes,
 	SubmitTransaction,

substrate/frame/membership/src/lib.rs

@@ -28,7 +28,7 @@ use frame_support::{
 	decl_module, decl_storage, decl_event, decl_error,
 	traits::{ChangeMembers, InitializeMembers, EnsureOrigin, Contains},
 };
-use frame_system::{self as system, ensure_signed};
+use frame_system::ensure_signed;
 
 pub trait Trait<I=DefaultInstance>: frame_system::Trait {
 	/// The overarching event type.

substrate/frame/nicks/src/lib.rs

@@ -47,7 +47,7 @@ use frame_support::{
 	decl_module, decl_event, decl_storage, ensure, decl_error,
 	traits::{Currency, EnsureOrigin, ReservableCurrency, OnUnbalanced, Get},
 };
-use frame_system::{self as system, ensure_signed};
+use frame_system::ensure_signed;
 
 type BalanceOf<T> = <<T as Trait>::Currency as Currency<<T as frame_system::Trait>::AccountId>>::Balance;
 type NegativeImbalanceOf<T> = <<T as Trait>::Currency as Currency<<T as frame_system::Trait>::AccountId>>::NegativeImbalance;

substrate/frame/offences/src/lib.rs

@@ -37,7 +37,6 @@ use sp_staking::{
 	offence::{Offence, ReportOffence, Kind, OnOffenceHandler, OffenceDetails, OffenceError},
 };
 use codec::{Encode, Decode};
-use frame_system as system;
 
 /// A binary blob which represents a SCALE codec-encoded `O::TimeSlot`.
 type OpaqueTimeSlot = Vec<u8>;

substrate/frame/scored-pool/src/lib.rs

@@ -55,7 +55,7 @@
 //!
 //! ```
 //! use frame_support::{decl_module, dispatch};
-//! use frame_system::{self as system, ensure_signed};
+//! use frame_system::ensure_signed;
 //! use pallet_scored_pool::{self as scored_pool};
 //!
 //! pub trait Trait: scored_pool::Trait {}
@@ -100,7 +100,7 @@ use frame_support::{
 	traits::{EnsureOrigin, ChangeMembers, InitializeMembers, Currency, Get, ReservableCurrency},
 	weights::Weight,
 };
-use frame_system::{self as system, ensure_root, ensure_signed};
+use frame_system::{ensure_root, ensure_signed};
 use sp_runtime::traits::{AtLeast32Bit, MaybeSerializeDeserialize, Zero, StaticLookup};
 
 type BalanceOf<T, I> = <<T as Trait<I>>::Currency as Currency<<T as frame_system::Trait>::AccountId>>::Balance;

substrate/frame/session/src/lib.rs

@@ -113,7 +113,7 @@ use frame_support::{
 	dispatch::{self, DispatchResult, DispatchError},
 	weights::Weight,
 };
-use frame_system::{self as system, ensure_signed};
+use frame_system::ensure_signed;
 
 #[cfg(test)]
 mod mock;
@@ -434,7 +434,7 @@ decl_storage! {
 			for (account, val, keys) in config.keys.iter().cloned() {
 				<Module<T>>::inner_set_keys(&val, keys)
 					.expect("genesis config must not contain duplicates; qed");
-				system::Module::<T>::inc_ref(&account);
+				frame_system::Module::<T>::inc_ref(&account);
 			}
 
 			let initial_validators_0 = T::SessionManager::new_session(0)
@@ -692,7 +692,7 @@ impl<T: Trait> Module<T> {
 
 		let old_keys = Self::inner_set_keys(&who, keys)?;
 		if old_keys.is_none() {
-			system::Module::<T>::inc_ref(&account);
+			frame_system::Module::<T>::inc_ref(&account);
 		}
 
 		Ok(())
@@ -740,7 +740,7 @@ impl<T: Trait> Module<T> {
 			let key_data = old_keys.get_raw(*id);
 			Self::clear_key_owner(*id, key_data);
 		}
-		system::Module::<T>::dec_ref(&account);
+		frame_system::Module::<T>::dec_ref(&account);
 
 		Ok(())
 	}

substrate/frame/staking/src/lib.rs

@@ -151,7 +151,7 @@
 //!
 //! ```
 //! use frame_support::{decl_module, dispatch};
-//! use frame_system::{self as system, ensure_signed};
+//! use frame_system::ensure_signed;
 //! use pallet_staking::{self as staking};
 //!
 //! pub trait Trait: staking::Trait {}

substrate/frame/sudo/src/lib.rs

@@ -53,7 +53,7 @@
 //!
 //! ```
 //! use frame_support::{decl_module, dispatch};
-//! use frame_system::{self as system, ensure_root};
+//! use frame_system::ensure_root;
 //!
 //! pub trait Trait: frame_system::Trait {}
 //!
@@ -94,7 +94,7 @@ use frame_support::{
 	Parameter, decl_module, decl_event, decl_storage, decl_error, ensure,
 };
 use frame_support::{weights::{Weight, GetDispatchInfo}, traits::UnfilteredDispatchable};
-use frame_system::{self as system, ensure_signed};
+use frame_system::ensure_signed;
 
 #[cfg(test)]
 mod mock;

substrate/frame/sudo/src/mock.rs

@@ -35,8 +35,8 @@ pub mod logger {
 	use super::*;
 	use frame_system::ensure_root;
 
-	pub trait Trait: system::Trait {
+	pub trait Trait: frame_system::Trait {
-		type Event: From<Event<Self>> + Into<<Self as system::Trait>::Event>;
+		type Event: From<Event<Self>> + Into<<Self as frame_system::Trait>::Event>;
 	}
 
 	decl_storage! {
@@ -54,7 +54,7 @@ pub mod logger {
 	}
 
 	decl_module! {
-		pub struct Module<T: Trait> for enum Call where origin: <T as system::Trait>::Origin {
+		pub struct Module<T: Trait> for enum Call where origin: <T as frame_system::Trait>::Origin {
 			fn deposit_event() = default;
 
 			#[weight = *weight]
@@ -87,7 +87,7 @@ mod test_events {
 
 impl_outer_event! {
 	pub enum TestEvent for Test {
-		system<T>,
+		frame_system<T>,
 		sudo<T>,
 		logger<T>,
 	}
@@ -161,7 +161,7 @@ impl Trait for Test {
 // Assign back to type variables in order to make dispatched calls of these modules later.
 pub type Sudo = Module<Test>;
 pub type Logger = logger::Module<Test>;
-pub type System = system::Module<Test>;
+pub type System = frame_system::Module<Test>;
 
 // New types for dispatchable functions.
 pub type SudoCall = sudo::Call<Test>;

substrate/frame/support/procedural/src/construct_runtime/mod.rs

@@ -59,7 +59,7 @@ fn construct_runtime_parsed(definition: RuntimeDefinition) -> Result<TokenStream
 			return Err(syn::Error::new(
 				modules_token.span,
 				"`System` module declaration is missing. \
-				 Please add this line: `System: system::{Module, Call, Storage, Config, Event<T>},`",
+				 Please add this line: `System: frame_system::{Module, Call, Storage, Config, Event<T>},`",
 			))
 		}
 	};

substrate/frame/support/src/dispatch.rs

@@ -70,7 +70,7 @@ impl<T> Parameter for T where T: Codec + EncodeLike + Clone + Eq + fmt::Debug {}
 /// # #[macro_use]
 /// # extern crate frame_support;
 /// # use frame_support::dispatch;
-/// # use frame_system::{self as system, Trait, ensure_signed};
+/// # use frame_system::{Trait, ensure_signed};
 /// decl_module! {
 /// 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
 ///
@@ -112,7 +112,7 @@ impl<T> Parameter for T where T: Codec + EncodeLike + Clone + Eq + fmt::Debug {}
 /// # #[macro_use]
 /// # extern crate frame_support;
 /// # use frame_support::dispatch;
-/// # use frame_system::{self as system, Trait, ensure_signed};
+/// # use frame_system::{Trait, ensure_signed};
 /// decl_module! {
 /// 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
 /// 		#[weight = 0]
@@ -147,7 +147,7 @@ impl<T> Parameter for T where T: Codec + EncodeLike + Clone + Eq + fmt::Debug {}
 /// # #[macro_use]
 /// # extern crate frame_support;
 /// # use frame_support::dispatch::{DispatchResultWithPostInfo, WithPostDispatchInfo};
-/// # use frame_system::{self as system, Trait, ensure_signed};
+/// # use frame_system::{Trait, ensure_signed};
 /// decl_module! {
 /// 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
 /// 		#[weight = 1_000_000]
@@ -175,7 +175,7 @@ impl<T> Parameter for T where T: Codec + EncodeLike + Clone + Eq + fmt::Debug {}
 /// # #[macro_use]
 /// # extern crate frame_support;
 /// # use frame_support::dispatch;
-/// # use frame_system::{self as system, Trait, ensure_signed, ensure_root};
+/// # use frame_system::{Trait, ensure_signed, ensure_root};
 /// decl_module! {
 /// 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
 /// 		#[weight = 0]
@@ -292,7 +292,7 @@ macro_rules! decl_module {
 			pub struct $mod_type<
 				$trait_instance: $trait_name $(<I>, I: $instantiable $(= $module_default_instance)?)?
 			>
-			for enum $call_type where origin: $origin_type, system = system
+			for enum $call_type where origin: $origin_type, system = frame_system
 			{ $( $where_ty: $where_bound ),* }
 			{}
 			{}
@@ -2339,7 +2339,7 @@ mod tests {
 	}
 
 	decl_module! {
-		pub struct Module<T: Trait> for enum Call where origin: T::Origin, T::AccountId: From<u32> {
+		pub struct Module<T: Trait> for enum Call where origin: T::Origin, system = system, T::AccountId: From<u32> {
 			/// Hi, this is a comment.
 			#[weight = 0]
 			fn aux_0(_origin) -> DispatchResult { unreachable!() }

substrate/frame/support/src/error.rs

@@ -47,7 +47,7 @@ pub use frame_metadata::{ModuleErrorMetadata, ErrorMetadata, DecodeDifferent};
 ///     }
 /// }
 ///
-/// # use frame_system::{self as system, Trait};
+/// # use frame_system::Trait;
 ///
 /// // You need to register the error type in `decl_module!` as well to make the error
 /// // exported in the metadata.

substrate/frame/support/src/weights.rs

@@ -39,7 +39,7 @@
 //!    `Yes`**.
 //!
 //! ```
-//! # use frame_system::{self as system, Trait};
+//! # use frame_system::Trait;
 //! frame_support::decl_module! {
 //!     pub struct Module<T: Trait> for enum Call where origin: T::Origin {
 //!         #[weight = 1000]
@@ -52,7 +52,7 @@
 //! 2.1 Define weight and class, **in which case `PaysFee` would be `Yes`**.
 //!
 //! ```
-//! # use frame_system::{self as system, Trait};
+//! # use frame_system::Trait;
 //! # use frame_support::weights::DispatchClass;
 //! frame_support::decl_module! {
 //!     pub struct Module<T: Trait> for enum Call where origin: T::Origin {
@@ -66,7 +66,7 @@
 //! 2.2 Define weight and `PaysFee`, **in which case `ClassifyDispatch` would be `Normal`**.
 //!
 //! ```
-//! # use frame_system::{self as system, Trait};
+//! # use frame_system::Trait;
 //! # use frame_support::weights::Pays;
 //! frame_support::decl_module! {
 //!     pub struct Module<T: Trait> for enum Call where origin: T::Origin {
@@ -80,7 +80,7 @@
 //! 3. Define all 3 parameters.
 //!
 //! ```
-//! # use frame_system::{self as system, Trait};
+//! # use frame_system::Trait;
 //! # use frame_support::weights::{DispatchClass, Pays};
 //! frame_support::decl_module! {
 //!     pub struct Module<T: Trait> for enum Call where origin: T::Origin {
@@ -100,7 +100,7 @@
 //! all 3 are static values, providing a raw tuple is easier.
 //!
 //! ```
-//! # use frame_system::{self as system, Trait};
+//! # use frame_system::Trait;
 //! # use frame_support::weights::{DispatchClass, FunctionOf, Pays};
 //! frame_support::decl_module! {
 //!     pub struct Module<T: Trait> for enum Call where origin: T::Origin {
@@ -589,7 +589,7 @@ pub trait WeightToFeePolynomial {
 		Self::polynomial().iter().fold(Self::Balance::saturated_from(0u32), |mut acc, args| {
 			let w = Self::Balance::saturated_from(*weight).saturating_pow(args.degree.into());
 
-			// The sum could get negative. Therefore we only sum with the accumulator. 
+			// The sum could get negative. Therefore we only sum with the accumulator.
 			// The Perbill Mul implementation is non overflowing.
 			let frac = args.coeff_frac * w;
 			let integer = args.coeff_integer.saturating_mul(w);

substrate/frame/support/test/tests/construct_runtime_ui/missing_system_module.stderr

@@ -1,4 +1,4 @@
-error: `System` module declaration is missing. Please add this line: `System: system::{Module, Call, Storage, Config, Event<T>},`
+error: `System` module declaration is missing. Please add this line: `System: frame_system::{Module, Call, Storage, Config, Event<T>},`
  --> $DIR/missing_system_module.rs:8:2
   |
 8 |       {

substrate/frame/support/test/tests/instance.rs

@@ -51,6 +51,7 @@ mod module1 {
 	frame_support::decl_module! {
 		pub struct Module<T: Trait<I>, I: InstantiableThing> for enum Call where
 			origin: <T as system::Trait>::Origin,
+			system = system,
 			T::BlockNumber: From<u32>
 		{
 			fn offchain_worker() {}
@@ -129,7 +130,8 @@ mod module2 {
 
 	frame_support::decl_module! {
 		pub struct Module<T: Trait<I>, I: Instance=DefaultInstance> for enum Call where
-			origin: <T as system::Trait>::Origin
+			origin: <T as system::Trait>::Origin,
+			system = system
 		{
 			fn deposit_event() = default;
 		}

substrate/frame/timestamp/src/lib.rs

@@ -64,7 +64,7 @@
 //! ```
 //! use frame_support::{decl_module, dispatch};
 //! # use pallet_timestamp as timestamp;
-//! use frame_system::{self as system, ensure_signed};
+//! use frame_system::ensure_signed;
 //!
 //! pub trait Trait: timestamp::Trait {}
 //!

substrate/frame/utility/src/lib.rs

@@ -64,7 +64,7 @@ use frame_support::{
 	traits::{OriginTrait, UnfilteredDispatchable},
 	weights::{Weight, GetDispatchInfo, DispatchClass}, dispatch::PostDispatchInfo,
 };
-use frame_system::{self as system, ensure_signed, ensure_root};
+use frame_system::{ensure_signed, ensure_root};
 use sp_runtime::{DispatchError, DispatchResult, traits::Dispatchable};
 
 mod tests;

substrate/frame/utility/src/tests.rs

@@ -34,7 +34,7 @@ impl_outer_origin! {
 }
 impl_outer_event! {
 	pub enum TestEvent for Test {
-		system<T>,
+		frame_system<T>,
 		pallet_balances<T>,
 		utility,
 	}
@@ -132,7 +132,7 @@ pub fn new_test_ext() -> sp_io::TestExternalities {
 }
 
 fn last_event() -> TestEvent {
-	system::Module::<Test>::events().pop().map(|e| e.event).expect("Event expected")
+	frame_system::Module::<Test>::events().pop().map(|e| e.event).expect("Event expected")
 }
 
 fn expect_event<E: Into<TestEvent>>(e: E) {

substrate/frame/vesting/src/lib.rs

@@ -58,7 +58,7 @@ use frame_support::traits::{
 	Currency, LockableCurrency, VestingSchedule, WithdrawReason, LockIdentifier,
 	ExistenceRequirement, Get
 };
-use frame_system::{self as system, ensure_signed, ensure_root};
+use frame_system::{ensure_signed, ensure_root};
 
 mod benchmarking;