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/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;
 		}