Fixes warnings in frame-support-procedural crate (paritytech#4915)

This PR fixes the unused warnings in `frame-support-procedural` crate,
raised by the latest stable rust release.

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

@@ -65,8 +65,6 @@ pub enum RuntimeDeclaration {
 /// Declaration of a runtime with some pallet with implicit declaration of parts.
 #[derive(Debug)]
 pub struct ImplicitRuntimeDeclaration {
-	pub name: Ident,
-	pub where_section: Option<WhereSection>,
 	pub pallets: Vec<PalletDeclaration>,
 }
 
@@ -98,11 +96,7 @@ impl Parse for RuntimeDeclaration {
 
 		match convert_pallets(pallets.content.inner.into_iter().collect())? {
 			PalletsConversion::Implicit(pallets) =>
-				Ok(RuntimeDeclaration::Implicit(ImplicitRuntimeDeclaration {
-					name,
-					where_section,
-					pallets,
-				})),
+				Ok(RuntimeDeclaration::Implicit(ImplicitRuntimeDeclaration { pallets })),
 			PalletsConversion::Explicit(pallets) =>
 				Ok(RuntimeDeclaration::Explicit(ExplicitRuntimeDeclaration {
 					name,
@@ -124,9 +118,6 @@ impl Parse for RuntimeDeclaration {
 #[derive(Debug)]
 pub struct WhereSection {
 	pub span: Span,
-	pub block: syn::TypePath,
-	pub node_block: syn::TypePath,
-	pub unchecked_extrinsic: syn::TypePath,
 }
 
 impl Parse for WhereSection {
@@ -145,18 +136,17 @@ impl Parse for WhereSection {
 			}
 			input.parse::<Token![,]>()?;
 		}
-		let block = remove_kind(input, WhereKind::Block, &mut definitions)?.value;
-		let node_block = remove_kind(input, WhereKind::NodeBlock, &mut definitions)?.value;
-		let unchecked_extrinsic =
-			remove_kind(input, WhereKind::UncheckedExtrinsic, &mut definitions)?.value;
+		remove_kind(input, WhereKind::Block, &mut definitions)?;
+		remove_kind(input, WhereKind::NodeBlock, &mut definitions)?;
+		remove_kind(input, WhereKind::UncheckedExtrinsic, &mut definitions)?;
 		if let Some(WhereDefinition { ref kind_span, ref kind, .. }) = definitions.first() {
 			let msg = format!(
 				"`{:?}` was declared above. Please use exactly one declaration for `{:?}`.",
 				kind, kind
 			);
 			return Err(Error::new(*kind_span, msg))
 		}
-		Ok(Self { span: input.span(), block, node_block, unchecked_extrinsic })
+		Ok(Self { span: input.span() })
 	}
 }
 
@@ -171,7 +161,6 @@ pub enum WhereKind {
 pub struct WhereDefinition {
 	pub kind_span: Span,
 	pub kind: WhereKind,
-	pub value: syn::TypePath,
 }
 
 impl Parse for WhereDefinition {
@@ -187,14 +176,10 @@ impl Parse for WhereDefinition {
 			return Err(lookahead.error())
 		};
 
-		Ok(Self {
-			kind_span,
-			kind,
-			value: {
-				let _: Token![=] = input.parse()?;
-				input.parse()?
-			},
-		})
+		let _: Token![=] = input.parse()?;
+		let _: syn::TypePath = input.parse()?;
+
+		Ok(Self { kind_span, kind })
 	}
 }
 

substrate/frame/support/procedural/src/pallet/expand/error.rs

@@ -71,23 +71,25 @@ pub fn expand_error(def: &mut Def) -> proc_macro2::TokenStream {
 		)
 	);
 
-	let as_str_matches = error.variants.iter().map(
-		|VariantDef { ident: variant, field: field_ty, docs: _, cfg_attrs }| {
-			let variant_str = variant.to_string();
-			let cfg_attrs = cfg_attrs.iter().map(|attr| attr.to_token_stream());
-			match field_ty {
-				Some(VariantField { is_named: true }) => {
-					quote::quote_spanned!(error.attr_span => #( #cfg_attrs )* Self::#variant { .. } => #variant_str,)
-				},
-				Some(VariantField { is_named: false }) => {
-					quote::quote_spanned!(error.attr_span => #( #cfg_attrs )* Self::#variant(..) => #variant_str,)
-				},
-				None => {
-					quote::quote_spanned!(error.attr_span => #( #cfg_attrs )* Self::#variant => #variant_str,)
-				},
-			}
-		},
-	);
+	let as_str_matches =
+		error
+			.variants
+			.iter()
+			.map(|VariantDef { ident: variant, field: field_ty, cfg_attrs }| {
+				let variant_str = variant.to_string();
+				let cfg_attrs = cfg_attrs.iter().map(|attr| attr.to_token_stream());
+				match field_ty {
+					Some(VariantField { is_named: true }) => {
+						quote::quote_spanned!(error.attr_span => #( #cfg_attrs )* Self::#variant { .. } => #variant_str,)
+					},
+					Some(VariantField { is_named: false }) => {
+						quote::quote_spanned!(error.attr_span => #( #cfg_attrs )* Self::#variant(..) => #variant_str,)
+					},
+					None => {
+						quote::quote_spanned!(error.attr_span => #( #cfg_attrs )* Self::#variant => #variant_str,)
+					},
+				}
+			});
 
 	let error_item = {
 		let item = &mut def.item.content.as_mut().expect("Checked by def parser").1[error.index];

substrate/frame/support/procedural/src/pallet/parse/composite.rs

@@ -87,8 +87,6 @@ pub mod keyword {
 }
 
 pub struct CompositeDef {
-	/// The index of the CompositeDef item in the pallet module.
-	pub index: usize,
 	/// The composite keyword used (contains span).
 	pub composite_keyword: keyword::CompositeKeyword,
 	/// Name of the associated type.
@@ -104,7 +102,6 @@ pub struct CompositeDef {
 impl CompositeDef {
 	pub fn try_from(
 		attr_span: proc_macro2::Span,
-		index: usize,
 		scrate: &syn::Path,
 		item: &mut syn::Item,
 	) -> syn::Result<Self> {
@@ -180,7 +177,6 @@ impl CompositeDef {
 			syn::parse2::<keyword::CompositeKeyword>(item.ident.to_token_stream())?;
 
 		Ok(CompositeDef {
-			index,
 			composite_keyword,
 			attr_span,
 			generics: item.generics.clone(),

substrate/frame/support/procedural/src/pallet/parse/config.rs

@@ -62,8 +62,6 @@ pub struct ConfigDef {
 	pub has_event_type: bool,
 	/// The where clause on trait definition but modified so `Self` is `T`.
 	pub where_clause: Option<syn::WhereClause>,
-	/// The span of the pallet::config attribute.
-	pub attr_span: proc_macro2::Span,
 	/// Whether a default sub-trait should be generated.
 	///
 	/// Contains default sub-trait items (instantiated by `#[pallet::config(with_default)]`).
@@ -325,7 +323,6 @@ pub fn replace_self_by_t(input: proc_macro2::TokenStream) -> proc_macro2::TokenS
 impl ConfigDef {
 	pub fn try_from(
 		frame_system: &syn::Path,
-		attr_span: proc_macro2::Span,
 		index: usize,
 		item: &mut syn::Item,
 		enable_default: bool,
@@ -484,7 +481,6 @@ impl ConfigDef {
 			consts_metadata,
 			has_event_type,
 			where_clause,
-			attr_span,
 			default_sub_trait,
 		})
 	}

substrate/frame/support/procedural/src/pallet/parse/error.rs

@@ -16,7 +16,6 @@
 // limitations under the License.
 
 use super::helper;
-use frame_support_procedural_tools::get_doc_literals;
 use quote::ToTokens;
 use syn::{spanned::Spanned, Fields};
 
@@ -37,8 +36,6 @@ pub struct VariantDef {
 	pub ident: syn::Ident,
 	/// The variant field, if any.
 	pub field: Option<VariantField>,
-	/// The variant doc literals.
-	pub docs: Vec<syn::Expr>,
 	/// The `cfg` attributes.
 	pub cfg_attrs: Vec<syn::Attribute>,
 }
@@ -101,12 +98,7 @@ impl ErrorDef {
 				}
 				let cfg_attrs: Vec<syn::Attribute> = helper::get_item_cfg_attrs(&variant.attrs);
 
-				Ok(VariantDef {
-					ident: variant.ident.clone(),
-					field: field_ty,
-					docs: get_doc_literals(&variant.attrs),
-					cfg_attrs,
-				})
+				Ok(VariantDef { ident: variant.ident.clone(), field: field_ty, cfg_attrs })
 			})
 			.collect::<Result<_, _>>()?;
 

substrate/frame/support/procedural/src/pallet/parse/extra_constants.rs

@@ -37,8 +37,6 @@ pub struct ExtraConstantsDef {
 	pub where_clause: Option<syn::WhereClause>,
 	/// A set of usage of instance, must be check for consistency with trait.
 	pub instances: Vec<helper::InstanceUsage>,
-	/// The index of call item in pallet module.
-	pub index: usize,
 	/// The extra constant defined.
 	pub extra_constants: Vec<ExtraConstantDef>,
 }
@@ -77,7 +75,7 @@ impl syn::parse::Parse for ExtraConstAttr {
 }
 
 impl ExtraConstantsDef {
-	pub fn try_from(index: usize, item: &mut syn::Item) -> syn::Result<Self> {
+	pub fn try_from(item: &mut syn::Item) -> syn::Result<Self> {
 		let item = if let syn::Item::Impl(item) = item {
 			item
 		} else {
@@ -150,11 +148,6 @@ impl ExtraConstantsDef {
 			});
 		}
 
-		Ok(Self {
-			index,
-			instances,
-			where_clause: item.generics.where_clause.clone(),
-			extra_constants,
-		})
+		Ok(Self { instances, where_clause: item.generics.where_clause.clone(), extra_constants })
 	}
 }

substrate/frame/support/procedural/src/pallet/parse/genesis_build.rs

@@ -20,8 +20,6 @@ use syn::spanned::Spanned;
 
 /// Definition for pallet genesis build implementation.
 pub struct GenesisBuildDef {
-	/// The index of item in pallet module.
-	pub index: usize,
 	/// A set of usage of instance, must be check for consistency with trait.
 	pub instances: Option<Vec<helper::InstanceUsage>>,
 	/// The where_clause used.
@@ -31,11 +29,7 @@ pub struct GenesisBuildDef {
 }
 
 impl GenesisBuildDef {
-	pub fn try_from(
-		attr_span: proc_macro2::Span,
-		index: usize,
-		item: &mut syn::Item,
-	) -> syn::Result<Self> {
+	pub fn try_from(attr_span: proc_macro2::Span, item: &mut syn::Item) -> syn::Result<Self> {
 		let item = if let syn::Item::Impl(item) = item {
 			item
 		} else {
@@ -56,6 +50,6 @@ impl GenesisBuildDef {
 		let instances =
 			helper::check_genesis_builder_usage(item_trait)?.map(|instances| vec![instances]);
 
-		Ok(Self { attr_span, index, instances, where_clause: item.generics.where_clause.clone() })
+		Ok(Self { attr_span, instances, where_clause: item.generics.where_clause.clone() })
 	}
 }

substrate/frame/support/procedural/src/pallet/parse/hooks.rs

@@ -20,8 +20,6 @@ use syn::spanned::Spanned;
 
 /// Implementation of the pallet hooks.
 pub struct HooksDef {
-	/// The index of item in pallet.
-	pub index: usize,
 	/// A set of usage of instance, must be check for consistency with trait.
 	pub instances: Vec<helper::InstanceUsage>,
 	/// The where_clause used.
@@ -33,11 +31,7 @@ pub struct HooksDef {
 }
 
 impl HooksDef {
-	pub fn try_from(
-		attr_span: proc_macro2::Span,
-		index: usize,
-		item: &mut syn::Item,
-	) -> syn::Result<Self> {
+	pub fn try_from(attr_span: proc_macro2::Span, item: &mut syn::Item) -> syn::Result<Self> {
 		let item = if let syn::Item::Impl(item) = item {
 			item
 		} else {
@@ -77,7 +71,6 @@ impl HooksDef {
 
 		Ok(Self {
 			attr_span,
-			index,
 			instances,
 			has_runtime_upgrade,
 			where_clause: item.generics.where_clause.clone(),

substrate/frame/support/procedural/src/pallet/parse/inherent.rs

@@ -20,14 +20,12 @@ use syn::spanned::Spanned;
 
 /// The definition of the pallet inherent implementation.
 pub struct InherentDef {
-	/// The index of inherent item in pallet module.
-	pub index: usize,
 	/// A set of usage of instance, must be check for consistency with trait.
 	pub instances: Vec<helper::InstanceUsage>,
 }
 
 impl InherentDef {
-	pub fn try_from(index: usize, item: &mut syn::Item) -> syn::Result<Self> {
+	pub fn try_from(item: &mut syn::Item) -> syn::Result<Self> {
 		let item = if let syn::Item::Impl(item) = item {
 			item
 		} else {
@@ -55,6 +53,6 @@ impl InherentDef {
 			helper::check_impl_gen(&item.generics, item.impl_token.span())?,
 		];
 
-		Ok(InherentDef { index, instances })
+		Ok(InherentDef { instances })
 	}
 }

substrate/frame/support/procedural/src/pallet/parse/mod.rs

@@ -109,10 +109,9 @@ impl Def {
 			let pallet_attr: Option<PalletAttr> = helper::take_first_item_pallet_attr(item)?;
 
 			match pallet_attr {
-				Some(PalletAttr::Config(span, with_default)) if config.is_none() =>
+				Some(PalletAttr::Config(_, with_default)) if config.is_none() =>
 					config = Some(config::ConfigDef::try_from(
 						&frame_system,
-						span,
 						index,
 						item,
 						with_default,
@@ -122,7 +121,7 @@ impl Def {
 					pallet_struct = Some(p);
 				},
 				Some(PalletAttr::Hooks(span)) if hooks.is_none() => {
-					let m = hooks::HooksDef::try_from(span, index, item)?;
+					let m = hooks::HooksDef::try_from(span, item)?;
 					hooks = Some(m);
 				},
 				Some(PalletAttr::RuntimeCall(cw, span)) if call.is_none() =>
@@ -162,27 +161,27 @@ impl Def {
 					genesis_config = Some(g);
 				},
 				Some(PalletAttr::GenesisBuild(span)) if genesis_build.is_none() => {
-					let g = genesis_build::GenesisBuildDef::try_from(span, index, item)?;
+					let g = genesis_build::GenesisBuildDef::try_from(span, item)?;
 					genesis_build = Some(g);
 				},
 				Some(PalletAttr::RuntimeOrigin(_)) if origin.is_none() =>
-					origin = Some(origin::OriginDef::try_from(index, item)?),
+					origin = Some(origin::OriginDef::try_from(item)?),
 				Some(PalletAttr::Inherent(_)) if inherent.is_none() =>
-					inherent = Some(inherent::InherentDef::try_from(index, item)?),
+					inherent = Some(inherent::InherentDef::try_from(item)?),
 				Some(PalletAttr::Storage(span)) =>
 					storages.push(storage::StorageDef::try_from(span, index, item, dev_mode)?),
 				Some(PalletAttr::ValidateUnsigned(_)) if validate_unsigned.is_none() => {
-					let v = validate_unsigned::ValidateUnsignedDef::try_from(index, item)?;
+					let v = validate_unsigned::ValidateUnsignedDef::try_from(item)?;
 					validate_unsigned = Some(v);
 				},
 				Some(PalletAttr::TypeValue(span)) =>
 					type_values.push(type_value::TypeValueDef::try_from(span, index, item)?),
 				Some(PalletAttr::ExtraConstants(_)) =>
 					extra_constants =
-						Some(extra_constants::ExtraConstantsDef::try_from(index, item)?),
+						Some(extra_constants::ExtraConstantsDef::try_from(item)?),
 				Some(PalletAttr::Composite(span)) => {
 					let composite =
-						composite::CompositeDef::try_from(span, index, &frame_support, item)?;
+						composite::CompositeDef::try_from(span, &frame_support, item)?;
 					if composites.iter().any(|def| {
 						match (&def.composite_keyword, &composite.composite_keyword) {
 							(
@@ -722,7 +721,6 @@ impl syn::parse::Parse for PalletAttr {
 #[derive(Clone)]
 pub struct InheritedCallWeightAttr {
 	pub typename: syn::Type,
-	pub span: proc_macro2::Span,
 }
 
 impl syn::parse::Parse for InheritedCallWeightAttr {
@@ -744,6 +742,6 @@ impl syn::parse::Parse for InheritedCallWeightAttr {
 			return Err(lookahead.error())
 		};
 
-		Ok(Self { typename: buffer.parse()?, span: input.span() })
+		Ok(Self { typename: buffer.parse()? })
 	}
 }