Factor in module path while generating enum variant or fn names

frame/support/procedural/src/construct_runtime/expand/event.rs

@@ -99,7 +99,7 @@ fn expand_event_variant(
 	generics: &Generics,
 ) -> TokenStream {
 	let pallet_is_generic = !generics.params.is_empty();
-	let mod_name = &path.inner.segments.last().unwrap().ident;
+	let mod_name = &path.mod_name();
 
 	match (instance, pallet_is_generic) {
 		(Some(inst), true) => {
@@ -125,11 +125,11 @@ fn expand_event_conversion(
 	instance: Option<&Ident>,
 	pallet_event: &TokenStream,
 ) -> TokenStream {
-	let mod_name = &path.inner.segments.last().unwrap().ident;
-	let variant = if let Some(inst) = &instance {
+	let mod_name = path.mod_name();
+	let variant = if let Some(inst) = instance {
 		format_ident!("{}_{}", mod_name, inst)
 	} else {
-		mod_name.clone()
+		mod_name
 	};
 
 	quote!{
@@ -156,7 +156,7 @@ fn expand_event_metadata(
 	path: &PalletPath,
 	pallet_event: &TokenStream,
 ) -> TokenStream {
-	let mod_name = &path.inner.segments.last().unwrap().ident;
+	let mod_name = path.mod_name();
 
 	quote!{(stringify!(#mod_name), #scrate::event::FnEncode(#pallet_event::metadata)),}
 }
@@ -167,7 +167,7 @@ fn expand_pallet_event_fn(
 	instance: Option<&Ident>,
 	pallet_event: &TokenStream,
 ) -> TokenStream {
-	let mod_name = &path.inner.segments.last().unwrap().ident;
+	let mod_name = path.mod_name();
 	let fn_name = if let Some(inst) = instance {
 		format_ident!("__module_events_{}_{}", mod_name, inst)
 	} else {

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

@@ -135,7 +135,7 @@ fn expand_pallet_metadata_events(
 	decl: &Pallet,
 ) -> TokenStream {
 	if filtered_names.contains(&"Event") {
-		let mod_name = &decl.pallet.inner.segments.last().unwrap().ident;
+		let mod_name = decl.pallet.mod_name();
 		let event = if let Some(instance) = decl.instance.as_ref() {
 			format_ident!("__module_events_{}_{}", mod_name, instance)
 		} else {

frame/support/procedural/src/construct_runtime/expand/origin.rs

@@ -257,7 +257,7 @@ fn expand_origin_caller_variant(
 	generics: &Generics,
 ) -> TokenStream {
 	let pallet_is_generic = !generics.params.is_empty();
-	let mod_name = &path.inner.segments.last().unwrap().ident;
+	let mod_name = &path.mod_name();
 
 	match (instance, pallet_is_generic) {
 		(Some(inst), true) => {
@@ -284,11 +284,11 @@ fn expand_origin_pallet_conversions(
 	instance: Option<&Ident>,
 	generics: &Generics,
 ) -> TokenStream {
-	let mod_name = &path.inner.segments.last().unwrap().ident;
-	let variant = if let Some(inst) = &instance {
+	let mod_name = path.mod_name();
+	let variant = if let Some(inst) = instance {
 		format_ident!("{}_{}", mod_name, inst)
 	} else {
-		mod_name.clone()
+		mod_name
 	};
 
 	let pallet_is_generic = !generics.params.is_empty();

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

@@ -228,6 +228,21 @@ impl Parse for PalletPath {
 	}
 }
 
+impl PalletPath {
+	/// Return the snake-cased module name for this path.
+	pub fn mod_name(&self) -> Ident {
+		let mut iter = self.inner.segments.iter();
+		let mut mod_name =
+			iter.next().expect("Path should always have 1 segment; qed").ident.clone();
+
+		for segment in iter {
+			mod_name = quote::format_ident!("{}_{}", mod_name, segment.ident);
+		}
+
+		mod_name
+	}
+}
+
 impl quote::ToTokens for PalletPath {
 	fn to_tokens(&self, tokens: &mut TokenStream) {
 		self.inner.to_tokens(tokens);

frame/support/test/tests/construct_runtime.rs

@@ -272,7 +272,7 @@ fn origin_codec() {
 	let origin = OriginCaller::module1_Instance2(module1::Origin(Default::default()));
 	assert_eq!(origin.encode()[0], 33);
 
-	let origin = OriginCaller::module3(nested::module3::Origin);
+	let origin = OriginCaller::nested_module3(nested::module3::Origin);
 	assert_eq!(origin.encode()[0], 34);
 
 	let origin = OriginCaller::module1_Instance6(module1::Origin(Default::default()));