From 7e8baee5bddb3e7f6f4b19b8ffd4ef2a1b8f45f0 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Wed, 7 Aug 2024 18:05:05 +0300
Subject: [PATCH 01/30] metadata-ir: Introduce PalletAssociatedTypeMetadata

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 substrate/primitives/metadata-ir/src/types.rs | 26 +++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/substrate/primitives/metadata-ir/src/types.rs b/substrate/primitives/metadata-ir/src/types.rs
index b05f26ff55d4..9001d4c034e9 100644
--- a/substrate/primitives/metadata-ir/src/types.rs
+++ b/substrate/primitives/metadata-ir/src/types.rs
@@ -127,6 +127,8 @@ pub struct PalletMetadataIR<T: Form = MetaForm> {
 	pub constants: Vec<PalletConstantMetadataIR<T>>,
 	/// Pallet error metadata.
 	pub error: Option<PalletErrorMetadataIR<T>>,
+	/// Config's trait associated types.
+	pub associated_types: Vec<PalletAssociatedTypeMetadataIR<T>>,
 	/// Define the index of the pallet, this index will be used for the encoding of pallet event,
 	/// call and origin variants.
 	pub index: u8,
@@ -145,6 +147,7 @@ impl IntoPortable for PalletMetadataIR {
 			event: self.event.map(|event| event.into_portable(registry)),
 			constants: registry.map_into_portable(self.constants),
 			error: self.error.map(|error| error.into_portable(registry)),
+			associated_types: registry.map_into_portable(self.associated_types),
 			index: self.index,
 			docs: registry.map_into_portable(self.docs),
 		}
@@ -188,6 +191,29 @@ impl IntoPortable for ExtrinsicMetadataIR {
 	}
 }
 
+/// Metadata of a pallet's associated type.
+#[derive(Clone, PartialEq, Eq, Encode, Debug)]
+pub struct PalletAssociatedTypeMetadataIR<T: Form = MetaForm> {
+	/// The name of the associated type.
+	pub name: T::String,
+	/// The type of the associated type.
+	pub ty: T::Type,
+	/// The documentation of the associated type.
+	pub docs: Vec<T::String>,
+}
+
+impl IntoPortable for PalletAssociatedTypeMetadataIR {
+	type Output = PalletAssociatedTypeMetadataIR<PortableForm>;
+
+	fn into_portable(self, registry: &mut Registry) -> Self::Output {
+		PalletAssociatedTypeMetadataIR {
+			name: self.name.into_portable(registry),
+			ty: registry.register_type(&self.ty),
+			docs: registry.map_into_portable(self.docs),
+		}
+	}
+}
+
 /// Metadata of an extrinsic's signed extension.
 #[derive(Clone, PartialEq, Eq, Encode, Debug)]
 pub struct SignedExtensionMetadataIR<T: Form = MetaForm> {

From 1c12f1520605ae32454ca8ab6f480ce794285f65 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Wed, 7 Aug 2024 18:11:11 +0300
Subject: [PATCH 02/30] frame/config: Add associated types to parsed config

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../procedural/src/pallet/parse/config.rs     | 29 ++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/substrate/frame/support/procedural/src/pallet/parse/config.rs b/substrate/frame/support/procedural/src/pallet/parse/config.rs
index 6febaac9ffa3..d4b6169e018c 100644
--- a/substrate/frame/support/procedural/src/pallet/parse/config.rs
+++ b/substrate/frame/support/procedural/src/pallet/parse/config.rs
@@ -55,6 +55,8 @@ pub struct ConfigDef {
 	pub has_instance: bool,
 	/// Const associated type.
 	pub consts_metadata: Vec<ConstMetadataDef>,
+	/// Associated types metadata.
+	pub associated_types_metadata: Vec<AssociatedTypeMetadataDef>,
 	/// Whether the trait has the associated type `Event`, note that those bounds are
 	/// checked:
 	/// * `IsType<Self as frame_system::Config>::RuntimeEvent`
@@ -70,6 +72,23 @@ pub struct ConfigDef {
 	pub default_sub_trait: Option<DefaultTrait>,
 }
 
+/// Input definition for an associated type in pallet config.
+pub struct AssociatedTypeMetadataDef {
+	/// Name of the associated type.
+	pub ident: syn::Ident,
+	/// The doc associated.
+	pub doc: Vec<syn::Expr>,
+}
+
+impl From<&syn::TraitItemType> for AssociatedTypeMetadataDef {
+	fn from(trait_ty: &syn::TraitItemType) -> Self {
+		let ident = trait_ty.ident.clone();
+		let doc = get_doc_literals(&trait_ty.attrs);
+
+		Self { ident, doc }
+	}
+}
+
 /// Input definition for a constant in pallet config.
 pub struct ConstMetadataDef {
 	/// Name of the associated type.
@@ -366,6 +385,7 @@ impl ConfigDef {
 
 		let mut has_event_type = false;
 		let mut consts_metadata = vec![];
+		let mut associated_types_metadata = vec![];
 		let mut default_sub_trait = if enable_default {
 			Some(DefaultTrait {
 				items: Default::default(),
@@ -405,7 +425,7 @@ impl ConfigDef {
 						if !enable_default {
 							return Err(syn::Error::new(
 								pallet_attr._bracket.span.join(),
-								"`#[pallet:no_default]` can only be used if `#[pallet::config(with_default)]` \
+								"`#[pallet::no_default]` can only be used if `#[pallet::config(with_default)]` \
 								has been specified"
 							))
 						}
@@ -437,6 +457,12 @@ impl ConfigDef {
 				}
 			}
 
+			if !is_event && !already_constant {
+				if let syn::TraitItem::Type(ref ty) = trait_item {
+					associated_types_metadata.push(AssociatedTypeMetadataDef::from(ty));
+				}
+			}
+
 			if !already_no_default && enable_default {
 				default_sub_trait
 					.as_mut()
@@ -479,6 +505,7 @@ impl ConfigDef {
 			index,
 			has_instance,
 			consts_metadata,
+			associated_types_metadata,
 			has_event_type,
 			where_clause,
 			default_sub_trait,

From 20b22d8d314df7dfb6590f6d54857190231b77c2 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Wed, 7 Aug 2024 18:14:29 +0300
Subject: [PATCH 03/30] frame/expand: Implement associated types expansion

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../procedural/src/pallet/expand/config.rs    | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/substrate/frame/support/procedural/src/pallet/expand/config.rs b/substrate/frame/support/procedural/src/pallet/expand/config.rs
index 5cf4035a8f8b..7e67aae93410 100644
--- a/substrate/frame/support/procedural/src/pallet/expand/config.rs
+++ b/substrate/frame/support/procedural/src/pallet/expand/config.rs
@@ -95,3 +95,48 @@ Consequently, a runtime that wants to include this pallet must implement this tr
 		_ => Default::default(),
 	}
 }
+
+/// Generate the metadata for the associated types of the config trait.
+///
+/// Implements the `pallet_associated_types_metadata` function for the pallet.
+pub fn expand_config_metadata(def: &mut Def) -> proc_macro2::TokenStream {
+	let frame_support = &def.frame_support;
+	let type_impl_gen = &def.type_impl_generics(proc_macro2::Span::call_site());
+	let type_use_gen = &def.type_use_generics(proc_macro2::Span::call_site());
+	let pallet_ident = &def.pallet_struct.pallet;
+	let trait_use_gen = &def.trait_use_generics(proc_macro2::Span::call_site());
+
+	let mut where_clauses = vec![&def.config.where_clause];
+	where_clauses.extend(def.extra_constants.iter().map(|d| &d.where_clause));
+	let completed_where_clause = super::merge_where_clauses(&where_clauses);
+
+	let types = def.config.associated_types_metadata.iter().map(|metadata| {
+		let ident = &metadata.ident;
+		let ident_str = format!("{}", ident);
+
+		let no_docs = vec![];
+		let doc = if cfg!(feature = "no-metadata-docs") { &no_docs } else { &metadata.doc };
+
+		quote::quote!({
+			#frame_support::__private::metadata_ir::PalletAssociatedTypeMetadataIR {
+				name: #ident_str,
+				ty: #frame_support::__private::scale_info::meta_type::<
+						<<T as Config #trait_use_gen>::#ident
+					>(),
+				docs: #frame_support::__private::sp_std::vec![ #( #doc ),* ],
+			}
+		})
+	});
+
+	quote::quote!(
+		impl<#type_impl_gen> #pallet_ident<#type_use_gen> #completed_where_clause {
+
+			#[doc(hidden)]
+			pub fn pallet_associated_types_metadata()
+				-> #frame_support::__private::sp_std::vec::Vec<#frame_support::__private::metadata_ir::PalletAssociatedTypeMetadataIR>
+			{
+				#frame_support::__private::sp_std::vec![ #( #types ),* ]
+			}
+		}
+	)
+}

From 350efce92491f6cb21e641526e45cba339d2fa35 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Wed, 7 Aug 2024 18:17:37 +0300
Subject: [PATCH 04/30] frame/expand: Use provided cfgs for the associated
 types

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../support/procedural/src/pallet/expand/config.rs |  2 ++
 .../support/procedural/src/pallet/parse/config.rs  |  7 +++++--
 .../frame/support/procedural/tools/src/lib.rs      | 14 ++++++++++++++
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/substrate/frame/support/procedural/src/pallet/expand/config.rs b/substrate/frame/support/procedural/src/pallet/expand/config.rs
index 7e67aae93410..1921922781fe 100644
--- a/substrate/frame/support/procedural/src/pallet/expand/config.rs
+++ b/substrate/frame/support/procedural/src/pallet/expand/config.rs
@@ -113,11 +113,13 @@ pub fn expand_config_metadata(def: &mut Def) -> proc_macro2::TokenStream {
 	let types = def.config.associated_types_metadata.iter().map(|metadata| {
 		let ident = &metadata.ident;
 		let ident_str = format!("{}", ident);
+		let cfgs = &metadata.cfg;
 
 		let no_docs = vec![];
 		let doc = if cfg!(feature = "no-metadata-docs") { &no_docs } else { &metadata.doc };
 
 		quote::quote!({
+			#( #cfgs ) *
 			#frame_support::__private::metadata_ir::PalletAssociatedTypeMetadataIR {
 				name: #ident_str,
 				ty: #frame_support::__private::scale_info::meta_type::<
diff --git a/substrate/frame/support/procedural/src/pallet/parse/config.rs b/substrate/frame/support/procedural/src/pallet/parse/config.rs
index d4b6169e018c..f92f69c7a1d6 100644
--- a/substrate/frame/support/procedural/src/pallet/parse/config.rs
+++ b/substrate/frame/support/procedural/src/pallet/parse/config.rs
@@ -16,7 +16,7 @@
 // limitations under the License.
 
 use super::helper;
-use frame_support_procedural_tools::{get_doc_literals, is_using_frame_crate};
+use frame_support_procedural_tools::{get_cfg_attributes, get_doc_literals, is_using_frame_crate};
 use quote::ToTokens;
 use syn::{spanned::Spanned, token, Token};
 
@@ -78,14 +78,17 @@ pub struct AssociatedTypeMetadataDef {
 	pub ident: syn::Ident,
 	/// The doc associated.
 	pub doc: Vec<syn::Expr>,
+	/// The cfg associated.
+	pub cfg: Vec<syn::Attribute>,
 }
 
 impl From<&syn::TraitItemType> for AssociatedTypeMetadataDef {
 	fn from(trait_ty: &syn::TraitItemType) -> Self {
 		let ident = trait_ty.ident.clone();
 		let doc = get_doc_literals(&trait_ty.attrs);
+		let cfg = get_cfg_attributes(&trait_ty.attrs);
 
-		Self { ident, doc }
+		Self { ident, doc, cfg }
 	}
 }
 
diff --git a/substrate/frame/support/procedural/tools/src/lib.rs b/substrate/frame/support/procedural/tools/src/lib.rs
index ea53335a88fd..d1d7efaab01d 100644
--- a/substrate/frame/support/procedural/tools/src/lib.rs
+++ b/substrate/frame/support/procedural/tools/src/lib.rs
@@ -181,3 +181,17 @@ pub fn get_doc_literals(attrs: &[syn::Attribute]) -> Vec<syn::Expr> {
 		})
 		.collect()
 }
+
+/// Return all cfg attributes literals found.
+pub fn get_cfg_attributes(attrs: &[syn::Attribute]) -> Vec<syn::Attribute> {
+	attrs
+		.iter()
+		.filter_map(|attr| {
+			if let syn::Meta::List(meta) = &attr.meta {
+				meta.path.get_ident().filter(|ident| *ident == "cfg").map(|_| attr.clone())
+			} else {
+				None
+			}
+		})
+		.collect()
+}

From 3e97971d0b4840553dbc731d8f27737e130f4411 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Wed, 7 Aug 2024 18:33:25 +0300
Subject: [PATCH 05/30] frame/construct_runtime: Extract associated types from
 pallet config

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../src/construct_runtime/expand/metadata.rs          | 11 +++++++++++
 .../support/procedural/src/pallet/expand/config.rs    |  4 ++--
 .../frame/support/procedural/src/pallet/expand/mod.rs |  2 ++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/substrate/frame/support/procedural/src/construct_runtime/expand/metadata.rs b/substrate/frame/support/procedural/src/construct_runtime/expand/metadata.rs
index daef1b171617..cbefd9601701 100644
--- a/substrate/frame/support/procedural/src/construct_runtime/expand/metadata.rs
+++ b/substrate/frame/support/procedural/src/construct_runtime/expand/metadata.rs
@@ -49,6 +49,7 @@ pub fn expand_runtime_metadata(
 			let event = expand_pallet_metadata_events(&filtered_names, runtime, scrate, decl);
 			let constants = expand_pallet_metadata_constants(runtime, decl);
 			let errors = expand_pallet_metadata_errors(runtime, decl);
+			let associated_types = expand_pallet_metadata_associated_types(runtime, decl);
 			let docs = expand_pallet_metadata_docs(runtime, decl);
 			let attr = decl.cfg_pattern.iter().fold(TokenStream::new(), |acc, pattern| {
 				let attr = TokenStream::from_str(&format!("#[cfg({})]", pattern.original()))
@@ -70,6 +71,7 @@ pub fn expand_runtime_metadata(
 					constants: #constants,
 					error: #errors,
 					docs: #docs,
+					associated_types: #associated_types,
 				}
 			}
 		})
@@ -256,3 +258,12 @@ fn expand_pallet_metadata_docs(runtime: &Ident, decl: &Pallet) -> TokenStream {
 		#path::Pallet::<#runtime #(, #path::#instance)*>::pallet_documentation_metadata()
 	}
 }
+
+fn expand_pallet_metadata_associated_types(runtime: &Ident, decl: &Pallet) -> TokenStream {
+	let path = &decl.path;
+	let instance = decl.instance.as_ref().into_iter();
+
+	quote! {
+		#path::Pallet::<#runtime #(, #path::#instance)*>::pallet_associated_types_metadata()
+	}
+}
diff --git a/substrate/frame/support/procedural/src/pallet/expand/config.rs b/substrate/frame/support/procedural/src/pallet/expand/config.rs
index 1921922781fe..6b79c4b8b25a 100644
--- a/substrate/frame/support/procedural/src/pallet/expand/config.rs
+++ b/substrate/frame/support/procedural/src/pallet/expand/config.rs
@@ -99,7 +99,7 @@ Consequently, a runtime that wants to include this pallet must implement this tr
 /// Generate the metadata for the associated types of the config trait.
 ///
 /// Implements the `pallet_associated_types_metadata` function for the pallet.
-pub fn expand_config_metadata(def: &mut Def) -> proc_macro2::TokenStream {
+pub fn expand_config_metadata(def: &Def) -> proc_macro2::TokenStream {
 	let frame_support = &def.frame_support;
 	let type_impl_gen = &def.type_impl_generics(proc_macro2::Span::call_site());
 	let type_use_gen = &def.type_use_generics(proc_macro2::Span::call_site());
@@ -123,7 +123,7 @@ pub fn expand_config_metadata(def: &mut Def) -> proc_macro2::TokenStream {
 			#frame_support::__private::metadata_ir::PalletAssociatedTypeMetadataIR {
 				name: #ident_str,
 				ty: #frame_support::__private::scale_info::meta_type::<
-						<<T as Config #trait_use_gen>::#ident
+						<T as Config #trait_use_gen>::#ident
 					>(),
 				docs: #frame_support::__private::sp_std::vec![ #( #doc ),* ],
 			}
diff --git a/substrate/frame/support/procedural/src/pallet/expand/mod.rs b/substrate/frame/support/procedural/src/pallet/expand/mod.rs
index 067839c28463..3f9b50f79c0c 100644
--- a/substrate/frame/support/procedural/src/pallet/expand/mod.rs
+++ b/substrate/frame/support/procedural/src/pallet/expand/mod.rs
@@ -60,6 +60,7 @@ pub fn expand(mut def: Def) -> proc_macro2::TokenStream {
 	let constants = constants::expand_constants(&mut def);
 	let pallet_struct = pallet_struct::expand_pallet_struct(&mut def);
 	let config = config::expand_config(&mut def);
+	let associated_types = config::expand_config_metadata(&def);
 	let call = call::expand_call(&mut def);
 	let tasks = tasks::expand_tasks(&mut def);
 	let error = error::expand_error(&mut def);
@@ -101,6 +102,7 @@ storage item. Otherwise, all storage items are listed among [*Type Definitions*]
 		#constants
 		#pallet_struct
 		#config
+		#associated_types
 		#call
 		#tasks
 		#error

From 5d8021eb1b58d605e77bb16427092933525092bb Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Wed, 7 Aug 2024 19:30:44 +0300
Subject: [PATCH 06/30] frame/pallet: Introduce `config(without_metadata)`

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../procedural/src/pallet/parse/config.rs     |  4 +-
 .../procedural/src/pallet/parse/mod.rs        | 60 ++++++++++++++++---
 2 files changed, 56 insertions(+), 8 deletions(-)

diff --git a/substrate/frame/support/procedural/src/pallet/parse/config.rs b/substrate/frame/support/procedural/src/pallet/parse/config.rs
index f92f69c7a1d6..5c11bf8dbcaf 100644
--- a/substrate/frame/support/procedural/src/pallet/parse/config.rs
+++ b/substrate/frame/support/procedural/src/pallet/parse/config.rs
@@ -36,6 +36,7 @@ mod keyword {
 	syn::custom_keyword!(no_default);
 	syn::custom_keyword!(no_default_bounds);
 	syn::custom_keyword!(constant);
+	syn::custom_keyword!(without_metadata);
 }
 
 #[derive(Default)]
@@ -348,6 +349,7 @@ impl ConfigDef {
 		index: usize,
 		item: &mut syn::Item,
 		enable_default: bool,
+		without_metadata: bool,
 	) -> syn::Result<Self> {
 		let syn::Item::Trait(item) = item else {
 			let msg = "Invalid pallet::config, expected trait definition";
@@ -460,7 +462,7 @@ impl ConfigDef {
 				}
 			}
 
-			if !is_event && !already_constant {
+			if !without_metadata && !is_event && !already_constant {
 				if let syn::TraitItem::Type(ref ty) = trait_item {
 					associated_types_metadata.push(AssociatedTypeMetadataDef::from(ty));
 				}
diff --git a/substrate/frame/support/procedural/src/pallet/parse/mod.rs b/substrate/frame/support/procedural/src/pallet/parse/mod.rs
index f55b166c7917..fe709bf89ce8 100644
--- a/substrate/frame/support/procedural/src/pallet/parse/mod.rs
+++ b/substrate/frame/support/procedural/src/pallet/parse/mod.rs
@@ -43,6 +43,7 @@ pub mod tests;
 use composite::{keyword::CompositeKeyword, CompositeDef};
 use frame_support_procedural_tools::generate_access_from_frame_or_crate;
 use quote::ToTokens;
+use std::collections::HashSet;
 use syn::spanned::Spanned;
 
 /// Parsed definition of a pallet.
@@ -109,12 +110,13 @@ impl Def {
 			let pallet_attr: Option<PalletAttr> = helper::take_first_item_pallet_attr(item)?;
 
 			match pallet_attr {
-				Some(PalletAttr::Config(_, with_default)) if config.is_none() =>
+				Some(PalletAttr::Config{ with_default, without_metadata, ..}) if config.is_none() =>
 					config = Some(config::ConfigDef::try_from(
 						&frame_system,
 						index,
 						item,
 						with_default,
+						without_metadata,
 					)?),
 				Some(PalletAttr::Pallet(span)) if pallet_struct.is_none() => {
 					let p = pallet_struct::PalletStructDef::try_from(span, index, item)?;
@@ -548,6 +550,7 @@ mod keyword {
 	syn::custom_keyword!(event);
 	syn::custom_keyword!(config);
 	syn::custom_keyword!(with_default);
+	syn::custom_keyword!(without_metadata);
 	syn::custom_keyword!(hooks);
 	syn::custom_keyword!(inherent);
 	syn::custom_keyword!(error);
@@ -561,10 +564,35 @@ mod keyword {
 	syn::custom_keyword!(composite_enum);
 }
 
+/// The possible values for the `#[pallet::config]` attribute.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+enum ConfigValue {
+	/// `#[pallet::config(with_default)]`
+	WithDefault(keyword::with_default),
+	/// `#[pallet::config(without_metadata)]`
+	WithoutMetadata(keyword::without_metadata),
+}
+
+impl syn::parse::Parse for ConfigValue {
+	fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
+		if input.peek(keyword::with_default) {
+			Ok(ConfigValue::WithDefault(input.parse()?))
+		} else if input.peek(keyword::without_metadata) {
+			Ok(ConfigValue::WithoutMetadata(input.parse()?))
+		} else {
+			Err(input.error("expected `with_default` or `without_metadata`"))
+		}
+	}
+}
+
 /// Parse attributes for item in pallet module
 /// syntax must be `pallet::` (e.g. `#[pallet::config]`)
 enum PalletAttr {
-	Config(proc_macro2::Span, bool),
+	Config {
+		span: proc_macro2::Span,
+		with_default: bool,
+		without_metadata: bool,
+	},
 	Pallet(proc_macro2::Span),
 	Hooks(proc_macro2::Span),
 	/// A `#[pallet::call]` with optional attributes to specialize the behaviour.
@@ -626,7 +654,7 @@ enum PalletAttr {
 impl PalletAttr {
 	fn span(&self) -> proc_macro2::Span {
 		match self {
-			Self::Config(span, _) => *span,
+			Self::Config { span, .. } => *span,
 			Self::Pallet(span) => *span,
 			Self::Hooks(span) => *span,
 			Self::Tasks(span) => *span,
@@ -661,13 +689,31 @@ impl syn::parse::Parse for PalletAttr {
 		let lookahead = content.lookahead1();
 		if lookahead.peek(keyword::config) {
 			let span = content.parse::<keyword::config>()?.span();
-			let with_default = content.peek(syn::token::Paren);
-			if with_default {
+			if content.peek(syn::token::Paren) {
 				let inside_config;
+
+				// Parse (with_default, without_metadata) attributes.
 				let _paren = syn::parenthesized!(inside_config in content);
-				inside_config.parse::<keyword::with_default>()?;
+
+				let fields: syn::punctuated::Punctuated<ConfigValue, syn::Token![,]> =
+					inside_config.parse_terminated(ConfigValue::parse, syn::Token![,])?;
+				let config_values = fields.iter().collect::<Vec<_>>();
+
+				let with_default =
+					config_values.iter().any(|v| matches!(v, ConfigValue::WithDefault(_)));
+				let without_metadata =
+					config_values.iter().any(|v| matches!(v, ConfigValue::WithoutMetadata(_)));
+
+				// Check for duplicated attributes.
+				let config_set = config_values.iter().collect::<HashSet<_>>();
+				if config_set.len() != config_values.len() {
+					return Err(syn::Error::new(span, "Invalid duplicated attribute"))
+				}
+
+				Ok(PalletAttr::Config { span, with_default, without_metadata })
+			} else {
+				Ok(PalletAttr::Config { span, with_default: false, without_metadata: false })
 			}
-			Ok(PalletAttr::Config(span, with_default))
 		} else if lookahead.peek(keyword::pallet) {
 			Ok(PalletAttr::Pallet(content.parse::<keyword::pallet>()?.span()))
 		} else if lookahead.peek(keyword::hooks) {

From 5679244aa99794ef415a17992f2c237ee1f40440 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Wed, 7 Aug 2024 19:42:50 +0300
Subject: [PATCH 07/30] frame/pallet: Introduce `#[pallet::include_metadata]`
 for associated types

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../procedural/src/pallet/parse/config.rs     | 34 +++++++++++++++++--
 1 file changed, 31 insertions(+), 3 deletions(-)

diff --git a/substrate/frame/support/procedural/src/pallet/parse/config.rs b/substrate/frame/support/procedural/src/pallet/parse/config.rs
index 5c11bf8dbcaf..65b2b195e94c 100644
--- a/substrate/frame/support/procedural/src/pallet/parse/config.rs
+++ b/substrate/frame/support/procedural/src/pallet/parse/config.rs
@@ -36,7 +36,7 @@ mod keyword {
 	syn::custom_keyword!(no_default);
 	syn::custom_keyword!(no_default_bounds);
 	syn::custom_keyword!(constant);
-	syn::custom_keyword!(without_metadata);
+	syn::custom_keyword!(include_metadata);
 }
 
 #[derive(Default)]
@@ -167,6 +167,8 @@ pub enum PalletAttrType {
 	NoBounds(keyword::no_default_bounds),
 	#[peek(keyword::constant, name = "constant")]
 	Constant(keyword::constant),
+	#[peek(keyword::include_metadata, name = "include_metadata")]
+	IncludeMetadata(keyword::include_metadata),
 }
 
 /// Parsing for `#[pallet::X]`
@@ -349,7 +351,7 @@ impl ConfigDef {
 		index: usize,
 		item: &mut syn::Item,
 		enable_default: bool,
-		without_metadata: bool,
+		enable_associated_metadata: bool,
 	) -> syn::Result<Self> {
 		let syn::Item::Trait(item) = item else {
 			let msg = "Invalid pallet::config, expected trait definition";
@@ -406,6 +408,7 @@ impl ConfigDef {
 			let mut already_no_default = false;
 			let mut already_constant = false;
 			let mut already_no_default_bounds = false;
+			let mut already_collected_associated_type = false;
 
 			while let Ok(Some(pallet_attr)) =
 				helper::take_first_item_pallet_attr::<PalletAttr>(trait_item)
@@ -426,6 +429,31 @@ impl ConfigDef {
 							trait_item.span(),
 							"Invalid #[pallet::constant] in #[pallet::config], expected type item",
 						)),
+					(PalletAttrType::IncludeMetadata(_), syn::TraitItem::Type(ref typ)) => {
+						if is_event {
+							return Err(syn::Error::new(
+								pallet_attr._bracket.span.join(),
+								"Invalid #[pallet::include_metadata] in `type RuntimeEvent`, \
+								expected type item. The associated type `RuntimeEvent` is already collected.",
+							))
+						}
+
+						if already_constant {
+							return Err(syn::Error::new(
+								pallet_attr._bracket.span.join(),
+								"Invalid #[pallet::include_metadata] in #[pallet::constant], \
+								expected type item. Pallet constant's metadata is already collected.",
+							))
+						}
+
+						already_collected_associated_type = true;
+						associated_types_metadata.push(AssociatedTypeMetadataDef::from(typ));
+					}
+					(PalletAttrType::IncludeMetadata(_), _) =>
+						return Err(syn::Error::new(
+							pallet_attr._bracket.span.join(),
+							"Invalid #[pallet::include_metadata] in #[pallet::config], expected type item",
+						)),
 					(PalletAttrType::NoDefault(_), _) => {
 						if !enable_default {
 							return Err(syn::Error::new(
@@ -462,7 +490,7 @@ impl ConfigDef {
 				}
 			}
 
-			if !without_metadata && !is_event && !already_constant {
+			if !already_collected_associated_type && enable_associated_metadata {
 				if let syn::TraitItem::Type(ref ty) = trait_item {
 					associated_types_metadata.push(AssociatedTypeMetadataDef::from(ty));
 				}

From 958611ef5a5a5a73ca51878bce4a6e0b1b111740 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Wed, 7 Aug 2024 20:13:15 +0300
Subject: [PATCH 08/30] frame/pallet: Include associated type iff bounds
 contain TypeInfo

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../procedural/src/pallet/parse/config.rs     | 34 +++++++++++++++++--
 1 file changed, 31 insertions(+), 3 deletions(-)

diff --git a/substrate/frame/support/procedural/src/pallet/parse/config.rs b/substrate/frame/support/procedural/src/pallet/parse/config.rs
index 65b2b195e94c..2f8a0923b6c5 100644
--- a/substrate/frame/support/procedural/src/pallet/parse/config.rs
+++ b/substrate/frame/support/procedural/src/pallet/parse/config.rs
@@ -18,7 +18,7 @@
 use super::helper;
 use frame_support_procedural_tools::{get_cfg_attributes, get_doc_literals, is_using_frame_crate};
 use quote::ToTokens;
-use syn::{spanned::Spanned, token, Token};
+use syn::{spanned::Spanned, token, Token, TraitItemType};
 
 /// List of additional token to be used for parsing.
 mod keyword {
@@ -345,6 +345,23 @@ pub fn replace_self_by_t(input: proc_macro2::TokenStream) -> proc_macro2::TokenS
 		.collect()
 }
 
+/// Check that the trait item requires the `TypeInfo` bound (or similar).
+fn contains_type_info_bound(ty: &TraitItemType) -> bool {
+	const KNOWN_TYPE_INFO_BOUNDS: &[&str] = &[
+		// Explicit TypeInfo trait.
+		"TypeInfo",
+		// Implicit known substrate traits that implement type info.
+		// Note: Aim to keep this list as small as possible.
+		"Parameter",
+	];
+
+	ty.bounds.iter().any(|bound| {
+		let syn::TypeParamBound::Trait(bound) = bound else { return false };
+
+		KNOWN_TYPE_INFO_BOUNDS.iter().any(|known| bound.path.is_ident(known))
+	})
+}
+
 impl ConfigDef {
 	pub fn try_from(
 		frame_system: &syn::Path,
@@ -429,6 +446,9 @@ impl ConfigDef {
 							trait_item.span(),
 							"Invalid #[pallet::constant] in #[pallet::config], expected type item",
 						)),
+					// Pallet developer has explicitly requested to include metadata for this associated type.
+					//
+					// They must provide a type item that implements `TypeInfo`.
 					(PalletAttrType::IncludeMetadata(_), syn::TraitItem::Type(ref typ)) => {
 						if is_event {
 							return Err(syn::Error::new(
@@ -490,9 +510,17 @@ impl ConfigDef {
 				}
 			}
 
-			if !already_collected_associated_type && enable_associated_metadata {
+			// Metadata of associated types is collected by default, iff the associated type
+			// implements `TypeInfo`, or a similar trait that requires the `TypeInfo` bound.
+			if !already_collected_associated_type &&
+				enable_associated_metadata &&
+				!is_event && !already_constant
+			{
 				if let syn::TraitItem::Type(ref ty) = trait_item {
-					associated_types_metadata.push(AssociatedTypeMetadataDef::from(ty));
+					// Collect the metadata of the associated type if it implements `TypeInfo`.
+					if contains_type_info_bound(ty) {
+						associated_types_metadata.push(AssociatedTypeMetadataDef::from(ty));
+					}
 				}
 			}
 

From 7f26b67a7b33dc78c9fc2572a073e77bf14b2610 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Wed, 7 Aug 2024 20:13:37 +0300
Subject: [PATCH 09/30] frame/pallet: Proper flag for metdata collection

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 substrate/frame/support/procedural/src/pallet/parse/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/substrate/frame/support/procedural/src/pallet/parse/mod.rs b/substrate/frame/support/procedural/src/pallet/parse/mod.rs
index fe709bf89ce8..bf933bc820f3 100644
--- a/substrate/frame/support/procedural/src/pallet/parse/mod.rs
+++ b/substrate/frame/support/procedural/src/pallet/parse/mod.rs
@@ -116,7 +116,7 @@ impl Def {
 						index,
 						item,
 						with_default,
-						without_metadata,
+						!without_metadata,
 					)?),
 				Some(PalletAttr::Pallet(span)) if pallet_struct.is_none() => {
 					let p = pallet_struct::PalletStructDef::try_from(span, index, item)?;

From cc001f389f80abbdf511b911c2fd04007f1eedcb Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Thu, 8 Aug 2024 11:05:10 +0300
Subject: [PATCH 10/30] frame/tests/ui: Fix type in test

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../tests/pallet_ui/no_default_but_missing_with_default.stderr  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/substrate/frame/support/test/tests/pallet_ui/no_default_but_missing_with_default.stderr b/substrate/frame/support/test/tests/pallet_ui/no_default_but_missing_with_default.stderr
index e8df28a3046f..1b066bbe9fb8 100644
--- a/substrate/frame/support/test/tests/pallet_ui/no_default_but_missing_with_default.stderr
+++ b/substrate/frame/support/test/tests/pallet_ui/no_default_but_missing_with_default.stderr
@@ -1,4 +1,4 @@
-error: `#[pallet:no_default]` can only be used if `#[pallet::config(with_default)]` has been specified
+error: `#[pallet::no_default]` can only be used if `#[pallet::config(with_default)]` has been specified
   --> tests/pallet_ui/no_default_but_missing_with_default.rs:26:4
    |
 26 |         #[pallet::no_default]

From b2803e2f2f785702de70e0825274eeffdd014d46 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Thu, 8 Aug 2024 11:12:19 +0300
Subject: [PATCH 11/30] frame/tests/ui: Check config without metadata

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../pallet_ui/pass/config_without_metadata.rs | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 substrate/frame/support/test/tests/pallet_ui/pass/config_without_metadata.rs

diff --git a/substrate/frame/support/test/tests/pallet_ui/pass/config_without_metadata.rs b/substrate/frame/support/test/tests/pallet_ui/pass/config_without_metadata.rs
new file mode 100644
index 000000000000..9304b2ccc9bf
--- /dev/null
+++ b/substrate/frame/support/test/tests/pallet_ui/pass/config_without_metadata.rs
@@ -0,0 +1,32 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#[frame_support::pallet]
+mod pallet {
+	use frame_support::pallet_prelude::*;
+
+	#[pallet::config(without_metadata)]
+	pub trait Config: frame_system::Config {
+		#[pallet::constant]
+		type MyGetParam2: Get<Self::AccountId>;
+	}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+}
+
+fn main() {}

From 94007d8c3189d5781db5ffe9d31d54cdc8a56cbd Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Thu, 8 Aug 2024 11:12:34 +0300
Subject: [PATCH 12/30] frame/tests/ui: Check config with multiple attributes

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../pallet_ui/pass/config_multiple_attr.rs    | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 substrate/frame/support/test/tests/pallet_ui/pass/config_multiple_attr.rs

diff --git a/substrate/frame/support/test/tests/pallet_ui/pass/config_multiple_attr.rs b/substrate/frame/support/test/tests/pallet_ui/pass/config_multiple_attr.rs
new file mode 100644
index 000000000000..1eee25b333e4
--- /dev/null
+++ b/substrate/frame/support/test/tests/pallet_ui/pass/config_multiple_attr.rs
@@ -0,0 +1,32 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#[frame_support::pallet]
+mod pallet {
+	use frame_support::pallet_prelude::*;
+
+	#[pallet::config(with_default, without_metadata)]
+	pub trait Config: frame_system::Config {
+		#[pallet::constant]
+		type MyGetParam2: Get<Self::AccountId>;
+	}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+}
+
+fn main() {}

From 75d26971b5e5520fbf8937a74665f1f1018e32c8 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Thu, 8 Aug 2024 11:50:00 +0300
Subject: [PATCH 13/30] frame/tests/ui: Add negative test for duplicate
 attributes in config

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../procedural/src/pallet/parse/mod.rs        |  5 ++-
 .../tests/pallet_ui/config_duplicate_attr.rs  | 39 +++++++++++++++++++
 .../pallet_ui/config_duplicate_attr.stderr    |  5 +++
 3 files changed, 48 insertions(+), 1 deletion(-)
 create mode 100644 substrate/frame/support/test/tests/pallet_ui/config_duplicate_attr.rs
 create mode 100644 substrate/frame/support/test/tests/pallet_ui/config_duplicate_attr.stderr

diff --git a/substrate/frame/support/procedural/src/pallet/parse/mod.rs b/substrate/frame/support/procedural/src/pallet/parse/mod.rs
index bf933bc820f3..6f5a599b08ee 100644
--- a/substrate/frame/support/procedural/src/pallet/parse/mod.rs
+++ b/substrate/frame/support/procedural/src/pallet/parse/mod.rs
@@ -707,7 +707,10 @@ impl syn::parse::Parse for PalletAttr {
 				// Check for duplicated attributes.
 				let config_set = config_values.iter().collect::<HashSet<_>>();
 				if config_set.len() != config_values.len() {
-					return Err(syn::Error::new(span, "Invalid duplicated attribute"))
+					return Err(syn::Error::new(
+						span,
+						"Invalid duplicated attribute for `#[pallet::config]`. Please remove duplicates.",
+					));
 				}
 
 				Ok(PalletAttr::Config { span, with_default, without_metadata })
diff --git a/substrate/frame/support/test/tests/pallet_ui/config_duplicate_attr.rs b/substrate/frame/support/test/tests/pallet_ui/config_duplicate_attr.rs
new file mode 100644
index 000000000000..3d7b4f87d22c
--- /dev/null
+++ b/substrate/frame/support/test/tests/pallet_ui/config_duplicate_attr.rs
@@ -0,0 +1,39 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#[frame_support::pallet]
+mod pallet {
+	use frame_support::pallet_prelude::*;
+	use frame_system::pallet_prelude::*;
+
+	#[pallet::config(with_default, without_metadata, without_metadata)]
+	pub trait Config: frame_system::Config {
+		#[pallet::constant]
+		type MyGetParam2: Get<u32>;
+	}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(core::marker::PhantomData<T>);
+
+	#[pallet::hooks]
+	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {}
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {}
+}
+
+fn main() {}
diff --git a/substrate/frame/support/test/tests/pallet_ui/config_duplicate_attr.stderr b/substrate/frame/support/test/tests/pallet_ui/config_duplicate_attr.stderr
new file mode 100644
index 000000000000..7217aa370ed5
--- /dev/null
+++ b/substrate/frame/support/test/tests/pallet_ui/config_duplicate_attr.stderr
@@ -0,0 +1,5 @@
+error: Invalid duplicated attribute for `#[pallet::config]`. Please remove duplicates.
+  --> tests/pallet_ui/config_duplicate_attr.rs:23:12
+   |
+23 |     #[pallet::config(with_default, without_metadata, without_metadata)]
+   |               ^^^^^^

From ebcb4a0aa5e6c65d17f15d49262bb4b4b3482964 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Thu, 8 Aug 2024 11:53:49 +0300
Subject: [PATCH 14/30] frame/tests/ui: Add negative test for collecting
 metadata from constants

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../pallet_ui/config_metadata_on_constants.rs | 40 +++++++++++++++++++
 .../config_metadata_on_constants.stderr       |  5 +++
 2 files changed, 45 insertions(+)
 create mode 100644 substrate/frame/support/test/tests/pallet_ui/config_metadata_on_constants.rs
 create mode 100644 substrate/frame/support/test/tests/pallet_ui/config_metadata_on_constants.stderr

diff --git a/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_constants.rs b/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_constants.rs
new file mode 100644
index 000000000000..a4ff02aeb1cd
--- /dev/null
+++ b/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_constants.rs
@@ -0,0 +1,40 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#[frame_support::pallet]
+mod pallet {
+	use frame_support::pallet_prelude::*;
+	use frame_system::pallet_prelude::*;
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {
+		#[pallet::constant]
+        #[pallet::include_metadata]
+		type MyGetParam2: Get<u32>;
+	}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(core::marker::PhantomData<T>);
+
+	#[pallet::hooks]
+	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {}
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {}
+}
+
+fn main() {}
diff --git a/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_constants.stderr b/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_constants.stderr
new file mode 100644
index 000000000000..ac27bfe89a08
--- /dev/null
+++ b/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_constants.stderr
@@ -0,0 +1,5 @@
+error: Invalid #[pallet::include_metadata] in #[pallet::constant], expected type item. Pallet constant's metadata is already collected.
+  --> tests/pallet_ui/config_metadata_on_constants.rs:26:10
+   |
+26 |         #[pallet::include_metadata]
+   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^

From 51150217bf9cf8869a141e1cfe5f2dcd063e6594 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Thu, 8 Aug 2024 11:58:52 +0300
Subject: [PATCH 15/30] frame/tests/ui: Add negative test for metadata
 collection on events

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../pallet_ui/config_metadata_on_events.rs    | 43 +++++++++++++++++++
 .../config_metadata_on_events.stderr          |  5 +++
 2 files changed, 48 insertions(+)
 create mode 100644 substrate/frame/support/test/tests/pallet_ui/config_metadata_on_events.rs
 create mode 100644 substrate/frame/support/test/tests/pallet_ui/config_metadata_on_events.stderr

diff --git a/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_events.rs b/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_events.rs
new file mode 100644
index 000000000000..d91f86771bf6
--- /dev/null
+++ b/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_events.rs
@@ -0,0 +1,43 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#[frame_support::pallet]
+mod pallet {
+	use frame_support::pallet_prelude::*;
+	use frame_system::pallet_prelude::*;
+
+	#[pallet::config(with_default)]
+	pub trait Config: frame_system::Config {
+		#[pallet::no_default_bounds]
+		#[pallet::include_metadata]
+		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
+
+		#[pallet::constant]
+		type MyGetParam2: Get<u32>;
+	}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(core::marker::PhantomData<T>);
+
+	#[pallet::hooks]
+	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {}
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {}
+}
+
+fn main() {}
diff --git a/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_events.stderr b/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_events.stderr
new file mode 100644
index 000000000000..0c79929bca37
--- /dev/null
+++ b/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_events.stderr
@@ -0,0 +1,5 @@
+error: Invalid #[pallet::include_metadata] in `type RuntimeEvent`, expected type item. The associated type `RuntimeEvent` is already collected.
+  --> tests/pallet_ui/config_metadata_on_events.rs:26:4
+   |
+26 |         #[pallet::include_metadata]
+   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^

From aba029a471f26dd5e1c4286104eb53029ceafd15 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Thu, 8 Aug 2024 13:07:25 +0300
Subject: [PATCH 16/30] frame/tests: Check PalletAssociatedTypeMetadataIR
 collection

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../tests/pallet_associated_types_metadata.rs | 269 ++++++++++++++++++
 1 file changed, 269 insertions(+)
 create mode 100644 substrate/frame/support/test/tests/pallet_associated_types_metadata.rs

diff --git a/substrate/frame/support/test/tests/pallet_associated_types_metadata.rs b/substrate/frame/support/test/tests/pallet_associated_types_metadata.rs
new file mode 100644
index 000000000000..9de5d79ad34c
--- /dev/null
+++ b/substrate/frame/support/test/tests/pallet_associated_types_metadata.rs
@@ -0,0 +1,269 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use frame_support::{derive_impl, traits::ConstU32};
+use scale_info::meta_type;
+use sp_metadata_ir::PalletAssociatedTypeMetadataIR;
+
+pub type BlockNumber = u64;
+pub type Header = sp_runtime::generic::Header<u32, sp_runtime::traits::BlakeTwo256>;
+pub type Block = sp_runtime::generic::Block<Header, UncheckedExtrinsic>;
+pub type UncheckedExtrinsic = sp_runtime::generic::UncheckedExtrinsic<u32, RuntimeCall, (), ()>;
+
+/// Pallet without collectable associated types.
+#[frame_support::pallet]
+pub mod pallet {
+	use frame_support::pallet_prelude::*;
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {
+		// Runtime events already propagated to the metadata.
+		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
+
+		// Constants are already propagated.
+		#[pallet::constant]
+		type MyGetParam2: Get<u32>;
+	}
+
+	#[pallet::event]
+	pub enum Event<T: Config> {
+		TestEvent,
+	}
+}
+
+/// Pallet with default collectable associated types.
+#[frame_support::pallet]
+pub mod pallet2 {
+	use frame_support::pallet_prelude::*;
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {
+		// Runtime events already propagated to the metadata.
+		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
+
+		// Constants are already propagated.
+		#[pallet::constant]
+		type MyGetParam2: Get<u32>;
+
+		// Associated type included by default, because it requires TypeInfo bound.
+		/// Nonce doc.
+		type Nonce: TypeInfo;
+
+		// Associated type included by default, because it requires
+		// Parameter bound (indirect TypeInfo).
+		type AccountData: Parameter;
+
+		// Associated type without metadata bounds, not included.
+		type NotIncluded: From<u8>;
+	}
+
+	#[pallet::event]
+	pub enum Event<T: Config> {
+		TestEvent,
+	}
+}
+
+/// Pallet with implicit collectable associated types.
+#[frame_support::pallet]
+pub mod pallet3 {
+	use frame_support::pallet_prelude::*;
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+
+	// Associated types are not collected by default.
+	#[pallet::config(without_metadata)]
+	pub trait Config: frame_system::Config {
+		// Runtime events already propagated to the metadata.
+		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
+
+		// Constants are already propagated.
+		#[pallet::constant]
+		type MyGetParam2: Get<u32>;
+
+		// Explicitly include associated types.
+		#[pallet::include_metadata]
+		type Nonce: TypeInfo;
+
+		type AccountData: Parameter;
+
+		type NotIncluded: From<u8>;
+	}
+
+	#[pallet::event]
+	pub enum Event<T: Config> {
+		TestEvent,
+	}
+}
+
+impl pallet::Config for Runtime {
+	type RuntimeEvent = RuntimeEvent;
+	type MyGetParam2 = ConstU32<10>;
+}
+
+impl pallet2::Config for Runtime {
+	type RuntimeEvent = RuntimeEvent;
+	type MyGetParam2 = ConstU32<10>;
+	type Nonce = u64;
+	type AccountData = u16;
+	type NotIncluded = u8;
+}
+
+impl pallet3::Config for Runtime {
+	type RuntimeEvent = RuntimeEvent;
+	type MyGetParam2 = ConstU32<10>;
+	type Nonce = u64;
+	type AccountData = u16;
+	type NotIncluded = u8;
+}
+
+#[derive_impl(frame_system::config_preludes::TestDefaultConfig)]
+impl frame_system::Config for Runtime {
+	type BlockWeights = ();
+	type BlockLength = ();
+	type DbWeight = ();
+	type BaseCallFilter = frame_support::traits::Everything;
+	type RuntimeOrigin = RuntimeOrigin;
+	type Nonce = u64;
+	type RuntimeCall = RuntimeCall;
+	type Hash = sp_runtime::testing::H256;
+	type Hashing = sp_runtime::traits::BlakeTwo256;
+	type AccountId = u64;
+	type Lookup = sp_runtime::traits::IdentityLookup<Self::AccountId>;
+	type Block = Block;
+	type RuntimeEvent = RuntimeEvent;
+	type Version = ();
+	type PalletInfo = PalletInfo;
+	type AccountData = ();
+	type OnNewAccount = ();
+	type OnKilledAccount = ();
+	type SystemWeightInfo = ();
+	type SS58Prefix = ();
+	type OnSetCode = ();
+	type MaxConsumers = ConstU32<16>;
+}
+
+frame_support::construct_runtime!(
+	pub enum Runtime
+	{
+		System: frame_system,
+		Example: pallet,
+		DefaultInclusion: pallet2,
+		ExplicitInclusion: pallet3,
+	}
+);
+
+#[test]
+fn associated_types_metadata() {
+	fn maybe_docs(doc: Vec<&'static str>) -> Vec<&'static str> {
+		if cfg!(feature = "no-metadata-docs") {
+			vec![]
+		} else {
+			doc
+		}
+	}
+
+	let ir = Runtime::metadata_ir();
+
+	// No associated types to collect.
+	let pallet = ir.pallets.iter().find(|pallet| pallet.name == "Example").unwrap();
+	pretty_assertions::assert_eq!(pallet.associated_types, vec![]);
+
+	// Collect by default types that implement TypeInfo or Parameter.
+	let pallet = ir.pallets.iter().find(|pallet| pallet.name == "DefaultInclusion").unwrap();
+	pretty_assertions::assert_eq!(
+		pallet.associated_types,
+		vec![
+			PalletAssociatedTypeMetadataIR {
+				name: "Nonce",
+				ty: meta_type::<u64>(),
+				docs: maybe_docs(vec![" Nonce doc."]),
+			},
+			PalletAssociatedTypeMetadataIR {
+				name: "AccountData",
+				ty: meta_type::<u16>(),
+				docs: vec![],
+			}
+		]
+	);
+
+	// Explicitly include associated types.
+	let pallet = ir.pallets.iter().find(|pallet| pallet.name == "ExplicitInclusion").unwrap();
+	pretty_assertions::assert_eq!(
+		pallet.associated_types,
+		vec![PalletAssociatedTypeMetadataIR {
+			name: "Nonce",
+			ty: meta_type::<u64>(),
+			docs: vec![],
+		}]
+	);
+
+	// Check system pallet.
+	let pallet = ir.pallets.iter().find(|pallet| pallet.name == "System").unwrap();
+	pretty_assertions::assert_eq!(
+		pallet.associated_types,
+		vec![
+			PalletAssociatedTypeMetadataIR {
+				name: "RuntimeCall",
+				ty: meta_type::<RuntimeCall>(),
+				docs: maybe_docs(vec![" The aggregated `RuntimeCall` type."]),
+			},
+			PalletAssociatedTypeMetadataIR {
+				name: "Nonce",
+				ty: meta_type::<u64>(),
+				docs: maybe_docs(vec![" This stores the number of previous transactions associated with a sender account."]),
+			},
+			PalletAssociatedTypeMetadataIR {
+				name: "Hash",
+				ty: meta_type::<sp_runtime::testing::H256>(),
+				docs: maybe_docs(vec![" The output of the `Hashing` function."]),
+			},
+            PalletAssociatedTypeMetadataIR {
+				name: "Hashing",
+				ty: meta_type::<sp_runtime::traits::BlakeTwo256>(),
+				docs: maybe_docs(vec![" The hashing system (algorithm) being used in the runtime (e.g. Blake2)."]),
+			},
+            PalletAssociatedTypeMetadataIR {
+                name: "AccountId",
+                ty: meta_type::<u64>(),
+                docs: maybe_docs(vec![" The user account identifier type for the runtime."]),
+            },
+            PalletAssociatedTypeMetadataIR {
+                name: "Block",
+                ty: meta_type::<Block>(),
+                docs: maybe_docs(vec![
+                    " The Block type used by the runtime. This is used by `construct_runtime` to retrieve the",
+                    " extrinsics or other block specific data as needed.",
+                ]),
+            },
+            PalletAssociatedTypeMetadataIR {
+                name: "AccountData",
+                ty: meta_type::<()>(),
+                docs: maybe_docs(vec![
+                    " Data to be associated with an account (other than nonce/transaction counter, which this",
+                    " pallet does regardless).",
+                ]),
+            },
+		]
+	);
+}

From 6502c830889275418dc3392881aa52ce0da96dcf Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Thu, 8 Aug 2024 13:27:56 +0300
Subject: [PATCH 17/30] frame/support: Add documentation

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 substrate/frame/support/procedural/src/lib.rs |  9 +++
 substrate/frame/support/src/lib.rs            | 62 +++++++++++++++++++
 2 files changed, 71 insertions(+)

diff --git a/substrate/frame/support/procedural/src/lib.rs b/substrate/frame/support/procedural/src/lib.rs
index ef99faee86ae..05f6333cd275 100644
--- a/substrate/frame/support/procedural/src/lib.rs
+++ b/substrate/frame/support/procedural/src/lib.rs
@@ -955,6 +955,15 @@ pub fn event(_: TokenStream, _: TokenStream) -> TokenStream {
 	pallet_macro_stub()
 }
 
+///
+/// ---
+///
+/// Documentation for this macro can be found at `frame_support::pallet_macros::include_metadata`.
+#[proc_macro_attribute]
+pub fn include_metadata(_: TokenStream, _: TokenStream) -> TokenStream {
+	pallet_macro_stub()
+}
+
 ///
 /// ---
 ///
diff --git a/substrate/frame/support/src/lib.rs b/substrate/frame/support/src/lib.rs
index bd571571ee24..2d882dd224f5 100644
--- a/substrate/frame/support/src/lib.rs
+++ b/substrate/frame/support/src/lib.rs
@@ -1556,6 +1556,57 @@ pub mod pallet_macros {
 	/// * [`frame_support::derive_impl`].
 	/// * [`#[pallet::no_default]`](`no_default`)
 	/// * [`#[pallet::no_default_bounds]`](`no_default_bounds`)
+	///
+	/// ## Optional: `without_metadata`
+	///
+	/// By default, the associated types of the `Config` trait that require the `TypeInfo` or
+	/// `Parameter` bounds are included in the metadata of the pallet. Please note that the
+	/// `RuntimeEvent` and constants are already included in the metadata.
+	///
+	/// The optional `without_metadata` argument can be used to exclude these associated types
+	/// from the metadata collection.
+	///
+	/// Furthermore, the `without_metadata` argument can be used in combination with the
+	/// [`#[pallet::include_metadata]`](`include_metadata`) attribute to selectively include
+	/// only certain associated types in the metadata collection.
+	///
+	/// ```
+	/// #[frame_support::pallet]
+	/// mod pallet {
+	/// # 	use frame_support::pallet_prelude::*;
+	/// # 	use frame_system::pallet_prelude::*;
+	/// # 	use core::fmt::Debug;
+	/// # 	use frame_support::traits::Contains;
+	/// #
+	/// # 	pub trait SomeMoreComplexBound {}
+	/// #
+	/// 	#[pallet::pallet]
+	/// 	pub struct Pallet<T>(_);
+	///
+	/// 	#[pallet::config(with_default, without_metadata)] // <- with_default and without_metadata are optional
+	/// 	pub trait Config: frame_system::Config {
+	/// 		/// The overarching event type.
+	/// 		#[pallet::no_default_bounds] // Default with bounds is not supported for RuntimeEvent
+	/// 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
+	///
+	/// 		/// A simple type.
+	/// 		// Type that would have been included in metadata, but is now excluded.
+	/// 		type SimpleType: From<u32> + TypeInfo;
+	///
+	/// 		// The `pallet::include_metadata` is used to selectively include this type in metadata.
+	/// 		#[pallet::include_metadata]
+	/// 		type SelectivelyInclude: From<u32> + TypeInfo;
+	/// 	}
+	///
+	/// 	#[pallet::event]
+	/// 	pub enum Event<T: Config> {
+	/// 		SomeEvent(u16, u32),
+	/// 	}
+	/// }
+	/// ```
+	///
+	/// For more information, see:
+	/// * [`#[pallet::include_metadata]`](`include_metadata`)
 	pub use frame_support_procedural::config;
 
 	/// Allows defining an enum that gets composed as an aggregate enum by `construct_runtime`.
@@ -1935,6 +1986,17 @@ pub mod pallet_macros {
 	/// `Member`, available in [`frame_support::pallet_prelude`].
 	pub use frame_support_procedural::event;
 
+	/// Selectively includes associated types in the metadata.
+	///
+	/// The optional attribute allows you to selectively include associated types in the
+	/// metadata. This can be attached to trait items that implement `TypeInfo`.
+	///
+	/// By default all collectable associated types are included in the metadata.
+	///
+	/// This attribute can be used in combination with the
+	/// [`#[pallet::config(without_metadata)]`](`config`).
+	pub use frame_support_procedural::include_metadata;
+
 	/// Allows a pallet to declare a set of functions as a *dispatchable extrinsic*.
 	///
 	/// In slightly simplified terms, this macro declares the set of "transactions" of a

From e9571cbdd505ebfb57c567c988245c97413ae621 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Thu, 8 Aug 2024 13:33:52 +0300
Subject: [PATCH 18/30] Add PRdoc

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 prdoc/pr_5274.prdoc | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 prdoc/pr_5274.prdoc

diff --git a/prdoc/pr_5274.prdoc b/prdoc/pr_5274.prdoc
new file mode 100644
index 000000000000..44c7085ef9d7
--- /dev/null
+++ b/prdoc/pr_5274.prdoc
@@ -0,0 +1,24 @@
+title: Enrich metadata IR with associated types of config traits
+
+doc:
+  - audience: Runtime Dev
+    description: |
+      This feature is part of the upcoming metadata V16. The associated types of the `Config` trait that require the `TypeInfo`
+      or `Parameter` bounds are included in the metadata of the pallet. The metadata is not yet exposed to the end-user, however
+      the metadata intermediate representation (IR) contains these types.
+
+      Developers can opt out of metadata collection of the associated types by specifying `without_metadata` optional attribute
+      to the `#[pallet::config]`.
+
+      Furthermore, the `without_metadata` argument can be used in combination with the newly added `#[pallet::include_metadata]`
+      attribute to selectively include only certain associated types in the metadata collection.
+
+crates:
+  - name: frame-support-procedural
+    bump: minor
+  - name: frame-support-procedural-tools
+    bump: minor
+  - name: sp-metadata-ir
+    bump: minor
+  - name: pallet-assets
+    bump: minor
\ No newline at end of file

From 7429eb7102518da7f74390b2b67ac5fa0d0c6a3f Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Thu, 8 Aug 2024 13:48:35 +0300
Subject: [PATCH 19/30] Update prdoc

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 prdoc/pr_5274.prdoc | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/prdoc/pr_5274.prdoc b/prdoc/pr_5274.prdoc
index 44c7085ef9d7..f3ec67da4a42 100644
--- a/prdoc/pr_5274.prdoc
+++ b/prdoc/pr_5274.prdoc
@@ -15,10 +15,10 @@ doc:
 
 crates:
   - name: frame-support-procedural
-    bump: minor
+    bump: patch
   - name: frame-support-procedural-tools
-    bump: minor
+    bump: patch
   - name: sp-metadata-ir
-    bump: minor
+    bump: patch
   - name: pallet-assets
-    bump: minor
\ No newline at end of file
+    bump: patch

From 8a0c138490971761e52b74bf729686b7c5eff84c Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Thu, 8 Aug 2024 13:48:51 +0300
Subject: [PATCH 20/30] prdoc: Remove unneeded crate

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 prdoc/pr_5274.prdoc | 2 --
 1 file changed, 2 deletions(-)

diff --git a/prdoc/pr_5274.prdoc b/prdoc/pr_5274.prdoc
index f3ec67da4a42..85f7d1cc2862 100644
--- a/prdoc/pr_5274.prdoc
+++ b/prdoc/pr_5274.prdoc
@@ -20,5 +20,3 @@ crates:
     bump: patch
   - name: sp-metadata-ir
     bump: patch
-  - name: pallet-assets
-    bump: patch

From c6c1800fca82bb2003097f86811e9f53aefb5df2 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Thu, 8 Aug 2024 13:49:23 +0300
Subject: [PATCH 21/30] prdoc: Include frame-support

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 prdoc/pr_5274.prdoc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/prdoc/pr_5274.prdoc b/prdoc/pr_5274.prdoc
index 85f7d1cc2862..304e3e3f779e 100644
--- a/prdoc/pr_5274.prdoc
+++ b/prdoc/pr_5274.prdoc
@@ -14,6 +14,8 @@ doc:
       attribute to selectively include only certain associated types in the metadata collection.
 
 crates:
+  - name: frame-support
+    bump: patch
   - name: frame-support-procedural
     bump: patch
   - name: frame-support-procedural-tools

From 90c100c0c67c0d273613292093f574040d923fcd Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Thu, 8 Aug 2024 13:57:45 +0300
Subject: [PATCH 22/30] Prupdate

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 prdoc/pr_5274.prdoc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/prdoc/pr_5274.prdoc b/prdoc/pr_5274.prdoc
index 304e3e3f779e..fb76ce661b4e 100644
--- a/prdoc/pr_5274.prdoc
+++ b/prdoc/pr_5274.prdoc
@@ -21,4 +21,4 @@ crates:
   - name: frame-support-procedural-tools
     bump: patch
   - name: sp-metadata-ir
-    bump: patch
+    bump: major

From f703e4debebc402884edeb95a0fdf4a90a1245c5 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <60601340+lexnv@users.noreply.github.com>
Date: Tue, 1 Oct 2024 17:53:35 +0300
Subject: [PATCH 23/30] Update
 substrate/frame/support/test/tests/pallet_ui/config_metadata_on_constants.rs
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Bastian Köcher <git@kchr.de>
---
 .../test/tests/pallet_ui/config_metadata_on_constants.rs        | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_constants.rs b/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_constants.rs
index a4ff02aeb1cd..5452479b76e7 100644
--- a/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_constants.rs
+++ b/substrate/frame/support/test/tests/pallet_ui/config_metadata_on_constants.rs
@@ -23,7 +23,7 @@ mod pallet {
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
 		#[pallet::constant]
-        #[pallet::include_metadata]
+       	#[pallet::include_metadata]
 		type MyGetParam2: Get<u32>;
 	}
 

From fbd36bc6f624be0e867652aee00ba961071370f7 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <60601340+lexnv@users.noreply.github.com>
Date: Tue, 1 Oct 2024 17:53:43 +0300
Subject: [PATCH 24/30] Update
 substrate/frame/support/procedural/src/pallet/expand/config.rs
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Bastian Köcher <git@kchr.de>
---
 substrate/frame/support/procedural/src/pallet/expand/config.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/substrate/frame/support/procedural/src/pallet/expand/config.rs b/substrate/frame/support/procedural/src/pallet/expand/config.rs
index 6b79c4b8b25a..07c48a556005 100644
--- a/substrate/frame/support/procedural/src/pallet/expand/config.rs
+++ b/substrate/frame/support/procedural/src/pallet/expand/config.rs
@@ -112,7 +112,7 @@ pub fn expand_config_metadata(def: &Def) -> proc_macro2::TokenStream {
 
 	let types = def.config.associated_types_metadata.iter().map(|metadata| {
 		let ident = &metadata.ident;
-		let ident_str = format!("{}", ident);
+		let ident_str = ident.to_string();
 		let cfgs = &metadata.cfg;
 
 		let no_docs = vec![];

From 6be9ef3fe09c14d11fce7b0c773bab8e99cbe6c7 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <60601340+lexnv@users.noreply.github.com>
Date: Tue, 1 Oct 2024 17:54:18 +0300
Subject: [PATCH 25/30] Update substrate/frame/support/src/lib.rs
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Bastian Köcher <git@kchr.de>
---
 substrate/frame/support/src/lib.rs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/substrate/frame/support/src/lib.rs b/substrate/frame/support/src/lib.rs
index 232e52b267be..c8a7a39681b7 100644
--- a/substrate/frame/support/src/lib.rs
+++ b/substrate/frame/support/src/lib.rs
@@ -1566,8 +1566,7 @@ pub mod pallet_macros {
 	/// ## Optional: `without_metadata`
 	///
 	/// By default, the associated types of the `Config` trait that require the `TypeInfo` or
-	/// `Parameter` bounds are included in the metadata of the pallet. Please note that the
-	/// `RuntimeEvent` and constants are already included in the metadata.
+	/// `Parameter` bounds are included in the metadata of the pallet.
 	///
 	/// The optional `without_metadata` argument can be used to exclude these associated types
 	/// from the metadata collection.

From c9b0e2a7d3975b27ac67e2506dd9a9c4e7a9c123 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Tue, 1 Oct 2024 18:21:21 +0300
Subject: [PATCH 26/30] frame/parse: Include duplicates in error message

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../procedural/src/pallet/parse/mod.rs        | 32 ++++++++++++-------
 .../pallet_ui/config_duplicate_attr.stderr    |  2 +-
 2 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/substrate/frame/support/procedural/src/pallet/parse/mod.rs b/substrate/frame/support/procedural/src/pallet/parse/mod.rs
index 5a7ccf0e5c64..5ff7281311ca 100644
--- a/substrate/frame/support/procedural/src/pallet/parse/mod.rs
+++ b/substrate/frame/support/procedural/src/pallet/parse/mod.rs
@@ -43,7 +43,7 @@ pub mod tests;
 use composite::{keyword::CompositeKeyword, CompositeDef};
 use frame_support_procedural_tools::generate_access_from_frame_or_crate;
 use quote::ToTokens;
-use std::collections::HashSet;
+use std::collections::HashMap;
 use syn::spanned::Spanned;
 
 /// Parsed definition of a pallet.
@@ -698,18 +698,26 @@ impl syn::parse::Parse for PalletAttr {
 					inside_config.parse_terminated(ConfigValue::parse, syn::Token![,])?;
 				let config_values = fields.iter().collect::<Vec<_>>();
 
-				let with_default =
-					config_values.iter().any(|v| matches!(v, ConfigValue::WithDefault(_)));
+				let frequencies = config_values.iter().fold(HashMap::new(), |mut map, val| {
+					let string_name = match val {
+						ConfigValue::WithDefault(_) => "with_default",
+						ConfigValue::WithoutMetadata(_) => "without_metadata",
+					}
+					.to_string();
+					map.entry(string_name).and_modify(|frq| *frq += 1).or_insert(1);
+					map
+				});
+				let with_default = frequencies.get("with_default").copied().unwrap_or(0) > 0;
 				let without_metadata =
-					config_values.iter().any(|v| matches!(v, ConfigValue::WithoutMetadata(_)));
-
-				// Check for duplicated attributes.
-				let config_set = config_values.iter().collect::<HashSet<_>>();
-				if config_set.len() != config_values.len() {
-					return Err(syn::Error::new(
-						span,
-						"Invalid duplicated attribute for `#[pallet::config]`. Please remove duplicates.",
-					));
+					frequencies.get("without_metadata").copied().unwrap_or(0) > 0;
+
+				let duplicates = frequencies
+					.into_iter()
+					.filter_map(|(name, frq)| if frq > 1 { Some(name) } else { None })
+					.collect::<Vec<_>>();
+				if !duplicates.is_empty() {
+					let msg = format!("Invalid duplicated attribute for `#[pallet::config]`. Please remove duplicates: {}.", duplicates.join(", "));
+					return Err(syn::Error::new(span, msg));
 				}
 
 				Ok(PalletAttr::Config { span, with_default, without_metadata })
diff --git a/substrate/frame/support/test/tests/pallet_ui/config_duplicate_attr.stderr b/substrate/frame/support/test/tests/pallet_ui/config_duplicate_attr.stderr
index 7217aa370ed5..0fdbd94dc816 100644
--- a/substrate/frame/support/test/tests/pallet_ui/config_duplicate_attr.stderr
+++ b/substrate/frame/support/test/tests/pallet_ui/config_duplicate_attr.stderr
@@ -1,4 +1,4 @@
-error: Invalid duplicated attribute for `#[pallet::config]`. Please remove duplicates.
+error: Invalid duplicated attribute for `#[pallet::config]`. Please remove duplicates: without_metadata.
   --> tests/pallet_ui/config_duplicate_attr.rs:23:12
    |
 23 |     #[pallet::config(with_default, without_metadata, without_metadata)]

From 0382d322d7ec98db16e01b1b9389ccfee00869b7 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Tue, 1 Oct 2024 18:25:27 +0300
Subject: [PATCH 27/30] frame/parse: Change parsing with lookahead

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../frame/support/procedural/src/pallet/parse/mod.rs      | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/substrate/frame/support/procedural/src/pallet/parse/mod.rs b/substrate/frame/support/procedural/src/pallet/parse/mod.rs
index 5ff7281311ca..02aa7f7843e2 100644
--- a/substrate/frame/support/procedural/src/pallet/parse/mod.rs
+++ b/substrate/frame/support/procedural/src/pallet/parse/mod.rs
@@ -574,10 +574,12 @@ enum ConfigValue {
 
 impl syn::parse::Parse for ConfigValue {
 	fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
-		if input.peek(keyword::with_default) {
-			Ok(ConfigValue::WithDefault(input.parse()?))
+		let lookahead = input.lookahead1();
+
+		if lookahead.peek(keyword::with_default) {
+			input.parse().map(ConfigValue::WithDefault)
 		} else if input.peek(keyword::without_metadata) {
-			Ok(ConfigValue::WithoutMetadata(input.parse()?))
+			input.parse().map(ConfigValue::WithoutMetadata)
 		} else {
 			Err(input.error("expected `with_default` or `without_metadata`"))
 		}

From e52ba1dedbf45f27ee02f5ce13e33d798e3aa0b4 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Tue, 1 Oct 2024 18:30:46 +0300
Subject: [PATCH 28/30] frame/lib: Remove links to include_metadata

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 substrate/frame/support/src/lib.rs | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/substrate/frame/support/src/lib.rs b/substrate/frame/support/src/lib.rs
index c8a7a39681b7..41dcc9d3257d 100644
--- a/substrate/frame/support/src/lib.rs
+++ b/substrate/frame/support/src/lib.rs
@@ -1609,9 +1609,6 @@ pub mod pallet_macros {
 	/// 	}
 	/// }
 	/// ```
-	///
-	/// For more information, see:
-	/// * [`#[pallet::include_metadata]`](`include_metadata`)
 	pub use frame_support_procedural::config;
 
 	/// Allows defining an enum that gets composed as an aggregate enum by `construct_runtime`.

From 45f86ebe1714f0c09da78eac7fbcc44acef21eaf Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Tue, 1 Oct 2024 19:06:14 +0300
Subject: [PATCH 29/30] pallet/parse: Collect associated metadata while taking
 constants into account

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 .../procedural/src/pallet/parse/config.rs     | 56 +++++++++----------
 1 file changed, 28 insertions(+), 28 deletions(-)

diff --git a/substrate/frame/support/procedural/src/pallet/parse/config.rs b/substrate/frame/support/procedural/src/pallet/parse/config.rs
index 713c58f201f8..d85480731d3c 100644
--- a/substrate/frame/support/procedural/src/pallet/parse/config.rs
+++ b/substrate/frame/support/procedural/src/pallet/parse/config.rs
@@ -427,7 +427,7 @@ impl ConfigDef {
 			let mut already_no_default = false;
 			let mut already_constant = false;
 			let mut already_no_default_bounds = false;
-			let mut already_collected_associated_type = false;
+			let mut already_collected_associated_type = None;
 
 			while let Ok(Some(pallet_attr)) =
 				helper::take_first_item_pallet_attr::<PalletAttr>(trait_item)
@@ -452,23 +452,7 @@ impl ConfigDef {
 					//
 					// They must provide a type item that implements `TypeInfo`.
 					(PalletAttrType::IncludeMetadata(_), syn::TraitItem::Type(ref typ)) => {
-						if is_event {
-							return Err(syn::Error::new(
-								pallet_attr._bracket.span.join(),
-								"Invalid #[pallet::include_metadata] in `type RuntimeEvent`, \
-								expected type item. The associated type `RuntimeEvent` is already collected.",
-							))
-						}
-
-						if already_constant {
-							return Err(syn::Error::new(
-								pallet_attr._bracket.span.join(),
-								"Invalid #[pallet::include_metadata] in #[pallet::constant], \
-								expected type item. Pallet constant's metadata is already collected.",
-							))
-						}
-
-						already_collected_associated_type = true;
+						already_collected_associated_type = Some(pallet_attr._bracket.span.join());
 						associated_types_metadata.push(AssociatedTypeMetadataDef::from(typ));
 					}
 					(PalletAttrType::IncludeMetadata(_), _) =>
@@ -512,16 +496,32 @@ impl ConfigDef {
 				}
 			}
 
-			// Metadata of associated types is collected by default, iff the associated type
-			// implements `TypeInfo`, or a similar trait that requires the `TypeInfo` bound.
-			if !already_collected_associated_type &&
-				enable_associated_metadata &&
-				!is_event && !already_constant
-			{
-				if let syn::TraitItem::Type(ref ty) = trait_item {
-					// Collect the metadata of the associated type if it implements `TypeInfo`.
-					if contains_type_info_bound(ty) {
-						associated_types_metadata.push(AssociatedTypeMetadataDef::from(ty));
+			if let Some(span) = already_collected_associated_type {
+				// Events and constants are already propagated to the metadata
+				if is_event {
+					return Err(syn::Error::new(
+						span,
+						"Invalid #[pallet::include_metadata] in `type RuntimeEvent`, \
+						expected type item. The associated type `RuntimeEvent` is already collected.",
+					))
+				}
+
+				if already_constant {
+					return Err(syn::Error::new(
+						span,
+						"Invalid #[pallet::include_metadata] in #[pallet::constant], \
+						expected type item. Pallet constant's metadata is already collected.",
+					))
+				}
+			} else {
+				// Metadata of associated types is collected by default, if the associated type
+				// implements `TypeInfo`, or a similar trait that requires the `TypeInfo` bound.
+				if enable_associated_metadata && !is_event && !already_constant {
+					if let syn::TraitItem::Type(ref ty) = trait_item {
+						// Collect the metadata of the associated type if it implements `TypeInfo`.
+						if contains_type_info_bound(ty) {
+							associated_types_metadata.push(AssociatedTypeMetadataDef::from(ty));
+						}
 					}
 				}
 			}

From fb8b2d4de1f1cfae35a501085987f41f8af621d0 Mon Sep 17 00:00:00 2001
From: Alexandru Vasile <alexandru.vasile@parity.io>
Date: Tue, 1 Oct 2024 19:17:35 +0300
Subject: [PATCH 30/30] pallet/parse: Reverse enable metadata flag to disable
 metadata

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
---
 substrate/frame/support/procedural/src/pallet/parse/config.rs | 4 ++--
 substrate/frame/support/procedural/src/pallet/parse/mod.rs    | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/substrate/frame/support/procedural/src/pallet/parse/config.rs b/substrate/frame/support/procedural/src/pallet/parse/config.rs
index d85480731d3c..444e324844c4 100644
--- a/substrate/frame/support/procedural/src/pallet/parse/config.rs
+++ b/substrate/frame/support/procedural/src/pallet/parse/config.rs
@@ -370,7 +370,7 @@ impl ConfigDef {
 		index: usize,
 		item: &mut syn::Item,
 		enable_default: bool,
-		enable_associated_metadata: bool,
+		disable_associated_metadata: bool,
 	) -> syn::Result<Self> {
 		let syn::Item::Trait(item) = item else {
 			let msg = "Invalid pallet::config, expected trait definition";
@@ -516,7 +516,7 @@ impl ConfigDef {
 			} else {
 				// Metadata of associated types is collected by default, if the associated type
 				// implements `TypeInfo`, or a similar trait that requires the `TypeInfo` bound.
-				if enable_associated_metadata && !is_event && !already_constant {
+				if !disable_associated_metadata && !is_event && !already_constant {
 					if let syn::TraitItem::Type(ref ty) = trait_item {
 						// Collect the metadata of the associated type if it implements `TypeInfo`.
 						if contains_type_info_bound(ty) {
diff --git a/substrate/frame/support/procedural/src/pallet/parse/mod.rs b/substrate/frame/support/procedural/src/pallet/parse/mod.rs
index 02aa7f7843e2..8f12fe7bdc93 100644
--- a/substrate/frame/support/procedural/src/pallet/parse/mod.rs
+++ b/substrate/frame/support/procedural/src/pallet/parse/mod.rs
@@ -115,7 +115,7 @@ impl Def {
 						index,
 						item,
 						with_default,
-						!without_metadata,
+						without_metadata,
 					)?),
 				Some(PalletAttr::Pallet(span)) if pallet_struct.is_none() => {
 					let p = pallet_struct::PalletStructDef::try_from(span, index, item)?;