DeprecationInfo propagate #[allow(deprecated)] attribute into the generated code.

prdoc/pr_6312.prdoc

@@ -0,0 +1,18 @@
+title: DeprecationInfo propagate or automatically add allow(deprecated) attributes in the generated code.
+
+doc:
+  - audience: [Runtime Dev, Runtime User]
+    description: |
+     Propagates or automatically adds allow(deprecated) attributes on `Constants`, `RuntimeApis`, `Runtime Calls` and enum variants
+     to reduce noise produced by warnings inside generated code.
+
+crates:
+  - name: frame-support-procedural
+    bump: none
+  - name: frame-support
+    bump: none
+  - name: sp-api-proc-macro
+    bump: none
+  - name: sp-api
+    bump: none
+

substrate/frame/support/procedural/src/construct_runtime/expand/metadata.rs

@@ -74,6 +74,7 @@ pub fn expand_runtime_metadata(
 
 	quote! {
 		impl #runtime {
+			#[allow(deprecated)]
 			fn metadata_ir() -> #scrate::__private::metadata_ir::MetadataIR {
 				// Each runtime must expose the `runtime_metadata()` to fetch the runtime API metadata.
 				// The function is implemented by calling `impl_runtime_apis!`.

substrate/frame/support/procedural/src/construct_runtime/expand/outer_enums.rs

@@ -221,13 +221,15 @@ fn expand_enum_conversion(
 
 	quote! {
 		#attr
+		#[allow(deprecated)]
 		impl From<#pallet_enum> for #enum_name_ident {
 			fn from(x: #pallet_enum) -> Self {
 				#enum_name_ident
 				::#variant_name(x)
 			}
 		}
 		#attr
+		#[allow(deprecated)]
 		impl TryInto<#pallet_enum> for #enum_name_ident {
 			type Error = ();
 

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

@@ -757,6 +757,7 @@ pub(crate) fn decl_static_assertions(
 		);
 
 		quote! {
+			#[allow(deprecated)]
 			#scrate::__private::tt_call! {
 				macro = [{ #path::tt_error_token }]
 				your_tt_return = [{ #scrate::__private::tt_return }]

substrate/frame/support/procedural/src/deprecation.rs

@@ -179,3 +179,21 @@ pub fn variant_index_for_deprecation(index: u8, item: &Variant) -> u8 {
 		})
 		.unwrap_or(index)
 }
+
+/// Filters all of the `allow` and `deprecated` attributes.
+///
+/// `allow` attributes are returned as is while `deprecated` attributes are replaced by
+/// `#[allow(deprecated)]`.
+pub fn extract_or_return_allow_attrs(
+	items: &[syn::Attribute],
+) -> impl Iterator<Item = syn::Attribute> + '_ {
+	items.iter().filter_map(|attr| {
+		attr.path().is_ident("allow").then(|| attr.clone()).or_else(|| {
+			attr.path().is_ident("deprecated").then(|| {
+				syn::parse_quote! {
+					#[allow(deprecated)]
+				}
+			})
+		})
+	})
+}

substrate/frame/support/procedural/src/lib.rs

@@ -376,6 +376,7 @@ pub fn derive_eq_no_bound(input: TokenStream) -> TokenStream {
 	let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
 
 	quote::quote_spanned!(name.span() =>
+		#[allow(deprecated)]
 		const _: () = {
 			impl #impl_generics ::core::cmp::Eq for #name #ty_generics #where_clause {}
 		};

substrate/frame/support/procedural/src/no_bound/clone.rs

@@ -96,6 +96,7 @@ pub fn derive_clone_no_bound(input: proc_macro::TokenStream) -> proc_macro::Toke
 	quote::quote!(
 		const _: () = {
 			#[automatically_derived]
+			#[allow(deprecated)]
 			impl #impl_generics ::core::clone::Clone for #name #ty_generics #where_clause {
 				fn clone(&self) -> Self {
 					#impl_

substrate/frame/support/procedural/src/no_bound/debug.rs

@@ -110,6 +110,7 @@ pub fn derive_debug_no_bound(input: proc_macro::TokenStream) -> proc_macro::Toke
 	quote::quote!(
 		const _: () = {
 			#[automatically_derived]
+			#[allow(deprecated)]
 			impl #impl_generics ::core::fmt::Debug for #input_ident #ty_generics #where_clause {
 				fn fmt(&self, fmt: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
 					#impl_

substrate/frame/support/procedural/src/no_bound/default.rs

@@ -150,6 +150,7 @@ pub fn derive_default_no_bound(input: proc_macro::TokenStream) -> proc_macro::To
 	quote!(
 		const _: () = {
 			#[automatically_derived]
+			#[allow(deprecated)]
 			impl #impl_generics ::core::default::Default for #name #ty_generics #where_clause {
 				fn default() -> Self {
 					#impl_

substrate/frame/support/procedural/src/no_bound/ord.rs

@@ -64,6 +64,7 @@ pub fn derive_ord_no_bound(input: proc_macro::TokenStream) -> proc_macro::TokenS
 
 	quote::quote!(
 		const _: () = {
+			#[allow(deprecated)]
 			impl #impl_generics core::cmp::Ord for #name #ty_generics #where_clause {
 				fn cmp(&self, other: &Self) -> core::cmp::Ordering {
 					#impl_

substrate/frame/support/procedural/src/no_bound/partial_eq.rs

@@ -126,6 +126,7 @@ pub fn derive_partial_eq_no_bound(input: proc_macro::TokenStream) -> proc_macro:
 	quote::quote!(
 		const _: () = {
 			#[automatically_derived]
+			#[allow(deprecated)]
 			impl #impl_generics ::core::cmp::PartialEq for #name #ty_generics #where_clause {
 				fn eq(&self, other: &Self) -> bool {
 					#impl_

substrate/frame/support/procedural/src/no_bound/partial_ord.rs

@@ -78,6 +78,7 @@ pub fn derive_partial_ord_no_bound(input: proc_macro::TokenStream) -> proc_macro
 
 	quote::quote!(
 		const _: () = {
+			#[allow(deprecated)]
 			impl #impl_generics core::cmp::PartialOrd for #name #ty_generics #where_clause {
 				fn partial_cmp(&self, other: &Self) -> Option<core::cmp::Ordering> {
 					#impl_

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

@@ -16,6 +16,7 @@
 // limitations under the License.
 
 use crate::{
+	deprecation::extract_or_return_allow_attrs,
 	pallet::{
 		expand::warnings::{weight_constant_warning, weight_witness_warning},
 		parse::{call::CallWeightDef, helper::CallReturnType},
@@ -236,11 +237,10 @@ pub fn expand_call(def: &mut Def) -> proc_macro2::TokenStream {
 	let maybe_allow_attrs = methods
 		.iter()
 		.map(|method| {
-			method
-				.attrs
-				.iter()
-				.find(|attr| attr.path().is_ident("allow"))
-				.map_or(proc_macro2::TokenStream::new(), |attr| attr.to_token_stream())
+			let attrs = extract_or_return_allow_attrs(&method.attrs);
+			quote::quote! {
+					#(#attrs)*
+			}
 		})
 		.collect::<Vec<_>>();
 

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

@@ -47,6 +47,7 @@ Consequently, a runtime that wants to include this pallet must implement this tr
 			]
 		),
 	);
+	config_item.attrs.retain(|attr| !attr.path().is_ident("deprecated"));
 
 	// we only emit `DefaultConfig` if there are trait items, so an empty `DefaultConfig` is
 	// impossible consequently.

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

@@ -15,7 +15,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use crate::pallet::Def;
+use crate::{deprecation::extract_or_return_allow_attrs, pallet::Def};
 
 struct ConstDef {
 	/// Name of the associated type.
@@ -55,11 +55,16 @@ pub fn expand_constants(def: &mut Def) -> proc_macro2::TokenStream {
 			Ok(deprecation) => deprecation,
 			Err(e) => return e.into_compile_error(),
 		};
+
+		// Extracts #[allow] attributes, necessary so that we don't run into compiler warnings
+		let maybe_allow_attrs = extract_or_return_allow_attrs(&const_.attrs);
+
 		config_consts.push(ConstDef {
 			ident: const_.ident.clone(),
 			type_: const_.type_.clone(),
 			doc: const_.doc.clone(),
 			default_byte_impl: quote::quote!(
+				#(#maybe_allow_attrs)*
 				let value = <<T as Config #trait_use_gen>::#ident as
 					#frame_support::traits::Get<#const_type>>::get();
 				#frame_support::__private::codec::Encode::encode(&value)
@@ -79,12 +84,15 @@ pub fn expand_constants(def: &mut Def) -> proc_macro2::TokenStream {
 			Ok(deprecation) => deprecation,
 			Err(e) => return e.into_compile_error(),
 		};
+		// Extracts #[allow] attributes, necessary so that we don't run into compiler warnings
+		let maybe_allow_attrs = extract_or_return_allow_attrs(&const_.attrs);
 
 		extra_consts.push(ConstDef {
 			ident: const_.ident.clone(),
 			type_: const_.type_.clone(),
 			doc: const_.doc.clone(),
 			default_byte_impl: quote::quote!(
+				#(#maybe_allow_attrs)*
 				let value = <Pallet<#type_use_gen>>::#ident();
 				#frame_support::__private::codec::Encode::encode(&value)
 			),

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

@@ -16,6 +16,7 @@
 // limitations under the License.
 
 use crate::{
+	deprecation::extract_or_return_allow_attrs,
 	pallet::{
 		parse::error::{VariantDef, VariantField},
 		Def,
@@ -75,18 +76,18 @@ pub fn expand_error(def: &mut Def) -> proc_macro2::TokenStream {
 		error
 			.variants
 			.iter()
-			.map(|VariantDef { ident: variant, field: field_ty, cfg_attrs }| {
+			.map(|VariantDef { ident: variant, field: field_ty, cfg_attrs, maybe_allow_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,)
+						quote::quote_spanned!(error.attr_span => #( #cfg_attrs )* #(#maybe_allow_attrs)* Self::#variant { .. } => #variant_str,)
 					},
 					Some(VariantField { is_named: false }) => {
-						quote::quote_spanned!(error.attr_span => #( #cfg_attrs )* Self::#variant(..) => #variant_str,)
+						quote::quote_spanned!(error.attr_span => #( #cfg_attrs )* #(#maybe_allow_attrs)* Self::#variant(..) => #variant_str,)
 					},
 					None => {
-						quote::quote_spanned!(error.attr_span => #( #cfg_attrs )* Self::#variant => #variant_str,)
+						quote::quote_spanned!(error.attr_span => #( #cfg_attrs )* #(#maybe_allow_attrs)* Self::#variant => #variant_str,)
 					},
 				}
 			});
@@ -99,7 +100,6 @@ pub fn expand_error(def: &mut Def) -> proc_macro2::TokenStream {
 			unreachable!("Checked by error parser")
 		}
 	};
-
 	error_item.variants.insert(0, phantom_variant);
 
 	let capture_docs = if cfg!(feature = "no-metadata-docs") { "never" } else { "always" };
@@ -137,7 +137,12 @@ pub fn expand_error(def: &mut Def) -> proc_macro2::TokenStream {
 		));
 	}
 
+	// Extracts #[allow] attributes, necessary so that we don't run into compiler warnings
+	let maybe_allow_attrs: Vec<syn::Attribute> =
+		extract_or_return_allow_attrs(&error_item.attrs).collect();
+
 	quote::quote_spanned!(error.attr_span =>
+		#(#maybe_allow_attrs)*
 		impl<#type_impl_gen> core::fmt::Debug for #error_ident<#type_use_gen>
 			#config_where_clause
 		{
@@ -148,16 +153,18 @@ pub fn expand_error(def: &mut Def) -> proc_macro2::TokenStream {
 			}
 		}
 
+		#(#maybe_allow_attrs)*
 		impl<#type_impl_gen> #error_ident<#type_use_gen> #config_where_clause {
 			#[doc(hidden)]
 			pub fn as_str(&self) -> &'static str {
 				match &self {
-					Self::__Ignore(_, _) => unreachable!("`__Ignore` can never be constructed"),
+					#(#maybe_allow_attrs)* Self::__Ignore(_, _) => unreachable!("`__Ignore` can never be constructed"),
 					#( #as_str_matches )*
 				}
 			}
 		}
 
+		#(#maybe_allow_attrs)*
 		impl<#type_impl_gen> From<#error_ident<#type_use_gen>> for &'static str
 			#config_where_clause
 		{
@@ -166,6 +173,7 @@ pub fn expand_error(def: &mut Def) -> proc_macro2::TokenStream {
 			}
 		}
 
+		#(#maybe_allow_attrs)*
 		impl<#type_impl_gen> From<#error_ident<#type_use_gen>>
 			for #frame_support::sp_runtime::DispatchError
 			#config_where_clause
@@ -204,10 +212,12 @@ pub fn expand_error(def: &mut Def) -> proc_macro2::TokenStream {
 
 		pub use #error_token_unique_id as tt_error_token;
 
+		#(#maybe_allow_attrs)*
 		impl<#type_impl_gen> #error_ident<#type_use_gen> #config_where_clause {
 			#[allow(dead_code)]
 			#[doc(hidden)]
 			pub fn error_metadata() -> #frame_support::__private::metadata_ir::PalletErrorMetadataIR {
+				#(#maybe_allow_attrs)*
 				#frame_support::__private::metadata_ir::PalletErrorMetadataIR {
 					ty: #frame_support::__private::scale_info::meta_type::<#error_ident<#type_use_gen>>(),
 					deprecation_info: #deprecation,

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

@@ -16,6 +16,7 @@
 // limitations under the License.
 
 use crate::{
+	deprecation::extract_or_return_allow_attrs,
 	pallet::{parse::event::PalletEventDepositAttr, Def},
 	COUNTER,
 };
@@ -135,6 +136,10 @@ pub fn expand_event(def: &mut Def) -> proc_macro2::TokenStream {
 		#[scale_info(skip_type_params(#event_use_gen), capture_docs = #capture_docs)]
 	));
 
+	// Extracts #[allow] attributes, necessary so that we don't run into compiler warnings
+	let maybe_allow_attrs: Vec<syn::Attribute> =
+		extract_or_return_allow_attrs(&event_item.attrs).collect();
+
 	let deposit_event = if let Some(deposit_event) = &event.deposit_event {
 		let event_use_gen = &event.gen_kind.type_use_gen(event.attr_span);
 		let trait_use_gen = &def.trait_use_generics(event.attr_span);
@@ -146,6 +151,7 @@ pub fn expand_event(def: &mut Def) -> proc_macro2::TokenStream {
 
 		quote::quote_spanned!(*fn_span =>
 			impl<#type_impl_gen> #pallet_ident<#type_use_gen> #completed_where_clause {
+				#(#maybe_allow_attrs)*
 				#fn_vis fn deposit_event(event: Event<#event_use_gen>) {
 					let event = <
 						<T as Config #trait_use_gen>::RuntimeEvent as
@@ -180,10 +186,12 @@ pub fn expand_event(def: &mut Def) -> proc_macro2::TokenStream {
 
 		#deposit_event
 
+		#(#maybe_allow_attrs)*
 		impl<#event_impl_gen> From<#event_ident<#event_use_gen>> for () #event_where_clause {
 			fn from(_: #event_ident<#event_use_gen>) {}
 		}
 
+		#(#maybe_allow_attrs)*
 		impl<#event_impl_gen> #event_ident<#event_use_gen> #event_where_clause {
 			#[allow(dead_code)]
 			#[doc(hidden)]

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

@@ -124,12 +124,8 @@ storage item. Otherwise, all storage items are listed among [*Type Definitions*]
 		#composites
 	);
 
-	def.item
-		.content
-		.as_mut()
-		.expect("This is checked by parsing")
-		.1
-		.push(syn::Item::Verbatim(new_items));
+	let item = &mut def.item.content.as_mut().expect("This is checked by parsing").1;
+	item.push(syn::Item::Verbatim(new_items));
 
 	def.item.into_token_stream()
 }