Derive no bound macros (to be also used in pallet macro) (#7280)

* derive no bound macros * explicit different variant for partialeq * fix ui for 1.47 * Apply suggestions from code review Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com> * move test to frame-support-test * renames, code organization and remove expect as suggested * better doc * remove DebugStripped introduce RuntimeDebugNoBound * rename * fix test * fix ui test * fix line width * Update frame/support/src/lib.rs Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com> * Update frame/support/procedural/src/clone_no_bound.rs Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com> * Apply suggestions from code review Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com> * fix confusing dead code Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
2026-04-28 20:17:57 +00:00 · 2020-10-19 11:11:51 +02:00
parent 87c18598fc
commit 7ca9baf9b6
17 changed files with 760 additions and 2 deletions
@@ -0,0 +1,103 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2020 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 syn::spanned::Spanned;
+
+/// Derive Clone but do not bound any generic.
+pub fn derive_clone_no_bound(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+	let input: syn::DeriveInput = match syn::parse(input) {
+		Ok(input) => input,
+		Err(e) => return e.to_compile_error().into(),
+	};
+
+	let name = &input.ident;
+	let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
+
+	let impl_ = match input.data {
+		syn::Data::Struct(struct_) => match struct_.fields {
+			syn::Fields::Named(named) => {
+				let fields = named.named.iter()
+					.map(|i| &i.ident)
+					.map(|i| quote::quote_spanned!(i.span() =>
+						#i: core::clone::Clone::clone(&self.#i)
+					));
+
+				quote::quote!( Self { #( #fields, )* } )
+			},
+			syn::Fields::Unnamed(unnamed) => {
+				let fields = unnamed.unnamed.iter().enumerate()
+					.map(|(i, _)| syn::Index::from(i))
+					.map(|i| quote::quote_spanned!(i.span() =>
+						core::clone::Clone::clone(&self.#i)
+					));
+
+				quote::quote!( Self ( #( #fields, )* ) )
+			},
+			syn::Fields::Unit => {
+				quote::quote!( Self )
+			}
+		},
+		syn::Data::Enum(enum_) => {
+			let variants = enum_.variants.iter()
+				.map(|variant| {
+					let ident = &variant.ident;
+					match &variant.fields {
+						syn::Fields::Named(named) => {
+							let captured = named.named.iter().map(|i| &i.ident);
+							let cloned = captured.clone()
+								.map(|i| quote::quote_spanned!(i.span() =>
+									#i: core::clone::Clone::clone(#i)
+								));
+							quote::quote!(
+								Self::#ident { #( ref #captured, )* } => Self::#ident { #( #cloned, )*}
+							)
+						},
+						syn::Fields::Unnamed(unnamed) => {
+							let captured = unnamed.unnamed.iter().enumerate()
+								.map(|(i, f)| syn::Ident::new(&format!("_{}", i), f.span()));
+							let cloned = captured.clone()
+								.map(|i| quote::quote_spanned!(i.span() =>
+									core::clone::Clone::clone(#i)
+								));
+							quote::quote!(
+								Self::#ident ( #( ref #captured, )* ) => Self::#ident ( #( #cloned, )*)
+							)
+						},
+						syn::Fields::Unit => quote::quote!( Self::#ident => Self::#ident ),
+					}
+				});
+
+			quote::quote!(match self {
+				#( #variants, )*
+			})
+		},
+		syn::Data::Union(_) => {
+			let msg = "Union type not supported by `derive(CloneNoBound)`";
+			return syn::Error::new(input.span(), msg).to_compile_error().into()
+		},
+	};
+
+	quote::quote!(
+		const _: () = {
+			impl #impl_generics core::clone::Clone for #name #ty_generics #where_clause {
+				fn clone(&self) -> Self {
+					#impl_
+				}
+			}
+		};
+	).into()
+}