frame_support_procedural/runtime/parse/helper.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 crate::pallet::parse::helper::MutItemAttrs;
19use quote::ToTokens;
20
21pub(crate) fn take_first_item_runtime_attr<Attr>(
22 item: &mut impl MutItemAttrs,
23) -> syn::Result<Option<Attr>>
24where
25 Attr: syn::parse::Parse,
26{
27 let attrs = if let Some(attrs) = item.mut_item_attrs() { attrs } else { return Ok(None) };
28
29 if let Some(index) = attrs.iter().position(|attr| {
30 attr.path().segments.first().map_or(false, |segment| segment.ident == "runtime")
31 }) {
32 let runtime_attr = attrs.remove(index);
33 Ok(Some(syn::parse2(runtime_attr.into_token_stream())?))
34 } else {
35 Ok(None)
36 }
37}