frame_support_procedural/pallet/parse/
genesis_build.rs

1// This file is part of Substrate.
2
3// Copyright (C) Parity Technologies (UK) Ltd.
4// SPDX-License-Identifier: Apache-2.0
5
6// Licensed under the Apache License, Version 2.0 (the "License");
7// you may not use this file except in compliance with the License.
8// You may obtain a copy of the License at
9//
10// 	http://www.apache.org/licenses/LICENSE-2.0
11//
12// Unless required by applicable law or agreed to in writing, software
13// distributed under the License is distributed on an "AS IS" BASIS,
14// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15// See the License for the specific language governing permissions and
16// limitations under the License.
17
18use super::helper;
19use syn::spanned::Spanned;
20
21/// Definition for pallet genesis build implementation.
22pub struct GenesisBuildDef {
23	/// A set of usage of instance, must be check for consistency with trait.
24	pub instances: Option<Vec<helper::InstanceUsage>>,
25	/// The where_clause used.
26	pub where_clause: Option<syn::WhereClause>,
27	/// The span of the pallet::genesis_build attribute.
28	pub attr_span: proc_macro2::Span,
29}
30
31impl GenesisBuildDef {
32	pub fn try_from(attr_span: proc_macro2::Span, item: &mut syn::Item) -> syn::Result<Self> {
33		let item = if let syn::Item::Impl(item) = item {
34			item
35		} else {
36			let msg = "Invalid pallet::genesis_build, expected item impl";
37			return Err(syn::Error::new(item.span(), msg))
38		};
39
40		let item_trait = &item
41			.trait_
42			.as_ref()
43			.ok_or_else(|| {
44				let msg = "Invalid pallet::genesis_build, expected impl<..> GenesisBuild<..> \
45					for GenesisConfig<..>";
46				syn::Error::new(item.span(), msg)
47			})?
48			.1;
49
50		let instances =
51			helper::check_genesis_builder_usage(item_trait)?.map(|instances| vec![instances]);
52
53		Ok(Self { attr_span, instances, where_clause: item.generics.where_clause.clone() })
54	}
55}
frame_support_procedural/pallet/parse/genesis_build.rs

frame_support_procedural/pallet/parse/
genesis_build.rs
