Macros to use path instead of ident (#1474)

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

@@ -92,7 +92,7 @@ impl CompositeDef {
 	pub fn try_from(
 		attr_span: proc_macro2::Span,
 		index: usize,
-		scrate: &proc_macro2::Ident,
+		scrate: &syn::Path,
 		item: &mut syn::Item,
 	) -> syn::Result<Self> {
 		let item = if let syn::Item::Enum(item) = item {

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;
+use frame_support_procedural_tools::{get_doc_literals, is_using_frame_crate};
 use quote::ToTokens;
 use syn::{spanned::Spanned, token, Token};
 
@@ -165,24 +165,8 @@ pub struct PalletAttr {
 	typ: PalletAttrType,
 }
 
-pub struct ConfigBoundParse(syn::Ident);
-
-impl syn::parse::Parse for ConfigBoundParse {
-	fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
-		let ident = input.parse::<syn::Ident>()?;
-		input.parse::<syn::Token![::]>()?;
-		input.parse::<keyword::Config>()?;
-
-		if input.peek(syn::token::Lt) {
-			input.parse::<syn::AngleBracketedGenericArguments>()?;
-		}
-
-		Ok(Self(ident))
-	}
-}
-
-/// Parse for `IsType<<Sef as $ident::Config>::RuntimeEvent>` and retrieve `$ident`
-pub struct IsTypeBoundEventParse(syn::Ident);
+/// Parse for `IsType<<Self as $path>::RuntimeEvent>` and retrieve `$path`
+pub struct IsTypeBoundEventParse(syn::Path);
 
 impl syn::parse::Parse for IsTypeBoundEventParse {
 	fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
@@ -191,15 +175,13 @@ impl syn::parse::Parse for IsTypeBoundEventParse {
 		input.parse::<syn::Token![<]>()?;
 		input.parse::<syn::Token![Self]>()?;
 		input.parse::<syn::Token![as]>()?;
-		let ident = input.parse::<syn::Ident>()?;
-		input.parse::<syn::Token![::]>()?;
-		input.parse::<keyword::Config>()?;
+		let config_path = input.parse::<syn::Path>()?;
 		input.parse::<syn::Token![>]>()?;
 		input.parse::<syn::Token![::]>()?;
 		input.parse::<keyword::RuntimeEvent>()?;
 		input.parse::<syn::Token![>]>()?;
 
-		Ok(Self(ident))
+		Ok(Self(config_path))
 	}
 }
 
@@ -237,7 +219,7 @@ impl syn::parse::Parse for FromEventParse {
 /// Check if trait_item is `type RuntimeEvent`, if so checks its bounds are those expected.
 /// (Event type is reserved type)
 fn check_event_type(
-	frame_system: &syn::Ident,
+	frame_system: &syn::Path,
 	trait_item: &syn::TraitItem,
 	trait_has_instance: bool,
 ) -> syn::Result<bool> {
@@ -249,19 +231,16 @@ fn check_event_type(
 					no generics nor where_clause";
 				return Err(syn::Error::new(trait_item.span(), msg))
 			}
-			// Check bound contains IsType and From
 
+			// Check bound contains IsType and From
 			let has_is_type_bound = type_.bounds.iter().any(|s| {
 				syn::parse2::<IsTypeBoundEventParse>(s.to_token_stream())
-					.map_or(false, |b| b.0 == *frame_system)
+					.map_or(false, |b| has_expected_system_config(b.0, frame_system))
 			});
 
 			if !has_is_type_bound {
-				let msg = format!(
-					"Invalid `type RuntimeEvent`, associated type `RuntimeEvent` is reserved and must \
-					bound: `IsType<<Self as {}::Config>::RuntimeEvent>`",
-					frame_system,
-				);
+				let msg = "Invalid `type RuntimeEvent`, associated type `RuntimeEvent` is reserved and must \
+					bound: `IsType<<Self as frame_system::Config>::RuntimeEvent>`".to_string();
 				return Err(syn::Error::new(type_.span(), msg))
 			}
 
@@ -295,6 +274,43 @@ fn check_event_type(
 	}
 }
 
+/// Check that the path to `frame_system::Config` is valid, this is that the path is just
+/// `frame_system::Config` or when using the `frame` crate it is `frame::xyz::frame_system::Config`.
+fn has_expected_system_config(path: syn::Path, frame_system: &syn::Path) -> bool {
+	// Check if `frame_system` is actually 'frame_system'.
+	if path.segments.iter().all(|s| s.ident != "frame_system") {
+		return false
+	}
+
+	let mut expected_system_config =
+		match (is_using_frame_crate(&path), is_using_frame_crate(&frame_system)) {
+			(true, false) =>
+			// We can't use the path to `frame_system` from `frame` if `frame_system` is not being
+			// in scope through `frame`.
+				return false,
+			(false, true) =>
+			// We know that the only valid frame_system path is one that is `frame_system`, as
+			// `frame` re-exports it as such.
+				syn::parse2::<syn::Path>(quote::quote!(frame_system)).expect("is a valid path; qed"),
+			(_, _) =>
+			// They are either both `frame_system` or both `frame::xyz::frame_system`.
+				frame_system.clone(),
+		};
+
+	expected_system_config
+		.segments
+		.push(syn::PathSegment::from(syn::Ident::new("Config", path.span())));
+
+	// the parse path might be something like `frame_system::Config<...>`, so we
+	// only compare the idents along the path.
+	expected_system_config
+		.segments
+		.into_iter()
+		.map(|ps| ps.ident)
+		.collect::<Vec<_>>() ==
+		path.segments.into_iter().map(|ps| ps.ident).collect::<Vec<_>>()
+}
+
 /// Replace ident `Self` by `T`
 pub fn replace_self_by_t(input: proc_macro2::TokenStream) -> proc_macro2::TokenStream {
 	input
@@ -311,7 +327,7 @@ pub fn replace_self_by_t(input: proc_macro2::TokenStream) -> proc_macro2::TokenS
 
 impl ConfigDef {
 	pub fn try_from(
-		frame_system: &syn::Ident,
+		frame_system: &syn::Path,
 		attr_span: proc_macro2::Span,
 		index: usize,
 		item: &mut syn::Item,
@@ -352,8 +368,8 @@ impl ConfigDef {
 		};
 
 		let has_frame_system_supertrait = item.supertraits.iter().any(|s| {
-			syn::parse2::<ConfigBoundParse>(s.to_token_stream())
-				.map_or(false, |b| b.0 == *frame_system)
+			syn::parse2::<syn::Path>(s.to_token_stream())
+				.map_or(false, |b| has_expected_system_config(b, frame_system))
 		});
 
 		let mut has_event_type = false;
@@ -461,7 +477,8 @@ impl ConfigDef {
 				(try `pub trait Config: frame_system::Config {{ ...` or \
 				`pub trait Config<I: 'static>: frame_system::Config {{ ...`). \
 				To disable this check, use `#[pallet::disable_frame_system_supertrait_check]`",
-				frame_system, found,
+				frame_system.to_token_stream(),
+				found,
 			);
 			return Err(syn::Error::new(item.span(), msg))
 		}
@@ -477,3 +494,97 @@ impl ConfigDef {
 		})
 	}
 }
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	#[test]
+	fn has_expected_system_config_works() {
+		let frame_system = syn::parse2::<syn::Path>(quote::quote!(frame_system)).unwrap();
+		let path = syn::parse2::<syn::Path>(quote::quote!(frame_system::Config)).unwrap();
+		assert!(has_expected_system_config(path, &frame_system));
+	}
+
+	#[test]
+	fn has_expected_system_config_works_with_assoc_type() {
+		let frame_system = syn::parse2::<syn::Path>(quote::quote!(frame_system)).unwrap();
+		let path =
+			syn::parse2::<syn::Path>(quote::quote!(frame_system::Config<RuntimeCall = Call>))
+				.unwrap();
+		assert!(has_expected_system_config(path, &frame_system));
+	}
+
+	#[test]
+	fn has_expected_system_config_works_with_frame() {
+		let frame_system =
+			syn::parse2::<syn::Path>(quote::quote!(frame::deps::frame_system)).unwrap();
+		let path = syn::parse2::<syn::Path>(quote::quote!(frame_system::Config)).unwrap();
+		assert!(has_expected_system_config(path, &frame_system));
+	}
+
+	#[test]
+	fn has_expected_system_config_works_with_frame_full_path() {
+		let frame_system =
+			syn::parse2::<syn::Path>(quote::quote!(frame::deps::frame_system)).unwrap();
+		let path =
+			syn::parse2::<syn::Path>(quote::quote!(frame::deps::frame_system::Config)).unwrap();
+		assert!(has_expected_system_config(path, &frame_system));
+	}
+
+	#[test]
+	fn has_expected_system_config_works_with_other_frame_full_path() {
+		let frame_system =
+			syn::parse2::<syn::Path>(quote::quote!(frame::xyz::frame_system)).unwrap();
+		let path =
+			syn::parse2::<syn::Path>(quote::quote!(frame::xyz::frame_system::Config)).unwrap();
+		assert!(has_expected_system_config(path, &frame_system));
+	}
+
+	#[test]
+	fn has_expected_system_config_does_not_works_with_mixed_frame_full_path() {
+		let frame_system =
+			syn::parse2::<syn::Path>(quote::quote!(frame::xyz::frame_system)).unwrap();
+		let path =
+			syn::parse2::<syn::Path>(quote::quote!(frame::deps::frame_system::Config)).unwrap();
+		assert!(!has_expected_system_config(path, &frame_system));
+	}
+
+	#[test]
+	fn has_expected_system_config_does_not_works_with_other_mixed_frame_full_path() {
+		let frame_system =
+			syn::parse2::<syn::Path>(quote::quote!(frame::deps::frame_system)).unwrap();
+		let path =
+			syn::parse2::<syn::Path>(quote::quote!(frame::xyz::frame_system::Config)).unwrap();
+		assert!(!has_expected_system_config(path, &frame_system));
+	}
+
+	#[test]
+	fn has_expected_system_config_does_not_work_with_frame_full_path_if_not_frame_crate() {
+		let frame_system = syn::parse2::<syn::Path>(quote::quote!(frame_system)).unwrap();
+		let path =
+			syn::parse2::<syn::Path>(quote::quote!(frame::deps::frame_system::Config)).unwrap();
+		assert!(!has_expected_system_config(path, &frame_system));
+	}
+
+	#[test]
+	fn has_expected_system_config_unexpected_frame_system() {
+		let frame_system =
+			syn::parse2::<syn::Path>(quote::quote!(framez::deps::frame_system)).unwrap();
+		let path = syn::parse2::<syn::Path>(quote::quote!(frame_system::Config)).unwrap();
+		assert!(!has_expected_system_config(path, &frame_system));
+	}
+
+	#[test]
+	fn has_expected_system_config_unexpected_path() {
+		let frame_system = syn::parse2::<syn::Path>(quote::quote!(frame_system)).unwrap();
+		let path = syn::parse2::<syn::Path>(quote::quote!(frame_system::ConfigSystem)).unwrap();
+		assert!(!has_expected_system_config(path, &frame_system));
+	}
+
+	#[test]
+	fn has_expected_system_config_not_frame_system() {
+		let frame_system = syn::parse2::<syn::Path>(quote::quote!(something)).unwrap();
+		let path = syn::parse2::<syn::Path>(quote::quote!(something::Config)).unwrap();
+		assert!(!has_expected_system_config(path, &frame_system));
+	}
+}

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

@@ -37,7 +37,7 @@ pub mod type_value;
 pub mod validate_unsigned;
 
 use composite::{keyword::CompositeKeyword, CompositeDef};
-use frame_support_procedural_tools::generate_crate_access_2018;
+use frame_support_procedural_tools::generate_access_from_frame_or_crate;
 use syn::spanned::Spanned;
 
 /// Parsed definition of a pallet.
@@ -60,15 +60,15 @@ pub struct Def {
 	pub extra_constants: Option<extra_constants::ExtraConstantsDef>,
 	pub composites: Vec<composite::CompositeDef>,
 	pub type_values: Vec<type_value::TypeValueDef>,
-	pub frame_system: syn::Ident,
-	pub frame_support: syn::Ident,
+	pub frame_system: syn::Path,
+	pub frame_support: syn::Path,
 	pub dev_mode: bool,
 }
 
 impl Def {
 	pub fn try_from(mut item: syn::ItemMod, dev_mode: bool) -> syn::Result<Self> {
-		let frame_system = generate_crate_access_2018("frame-system")?;
-		let frame_support = generate_crate_access_2018("frame-support")?;
+		let frame_system = generate_access_from_frame_or_crate("frame-system")?;
+		let frame_support = generate_access_from_frame_or_crate("frame-support")?;
 
 		let item_span = item.span();
 		let items = &mut item