|  | 
|  | 1 | +use core::mem; | 
|  | 2 | + | 
|  | 3 | +use rustc_attr_data_structures::AttributeKind; | 
|  | 4 | +use rustc_feature::{AttributeTemplate, template}; | 
|  | 5 | +use rustc_span::{Symbol, sym}; | 
|  | 6 | + | 
|  | 7 | +use crate::attributes::{AttributeOrder, OnDuplicate, SingleAttributeParser}; | 
|  | 8 | +use crate::context::{AcceptContext, Stage}; | 
|  | 9 | +use crate::parser::ArgParser; | 
|  | 10 | + | 
|  | 11 | +pub(crate) struct SkipDuringMethodDispatchParser; | 
|  | 12 | + | 
|  | 13 | +impl<S: Stage> SingleAttributeParser<S> for SkipDuringMethodDispatchParser { | 
|  | 14 | +    const PATH: &[Symbol] = &[sym::rustc_skip_during_method_dispatch]; | 
|  | 15 | +    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepFirst; | 
|  | 16 | +    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error; | 
|  | 17 | + | 
|  | 18 | +    const TEMPLATE: AttributeTemplate = template!(List: "array, boxed_slice"); | 
|  | 19 | + | 
|  | 20 | +    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> { | 
|  | 21 | +        let mut array = false; | 
|  | 22 | +        let mut boxed_slice = false; | 
|  | 23 | +        let Some(args) = args.list() else { | 
|  | 24 | +            cx.expected_list(cx.attr_span); | 
|  | 25 | +            return None; | 
|  | 26 | +        }; | 
|  | 27 | +        if args.is_empty() { | 
|  | 28 | +            cx.expected_at_least_one_argument(args.span); | 
|  | 29 | +            return None; | 
|  | 30 | +        } | 
|  | 31 | +        for arg in args.mixed() { | 
|  | 32 | +            let Some(arg) = arg.meta_item() else { | 
|  | 33 | +                cx.unexpected_literal(arg.span()); | 
|  | 34 | +                continue; | 
|  | 35 | +            }; | 
|  | 36 | +            if let Err(span) = arg.args().no_args() { | 
|  | 37 | +                cx.expected_no_args(span); | 
|  | 38 | +            } | 
|  | 39 | +            let path = arg.path(); | 
|  | 40 | +            let (key, skip): (Symbol, &mut bool) = match path.word_sym() { | 
|  | 41 | +                Some(key @ sym::array) => (key, &mut array), | 
|  | 42 | +                Some(key @ sym::boxed_slice) => (key, &mut boxed_slice), | 
|  | 43 | +                _ => { | 
|  | 44 | +                    cx.expected_specific_argument(path.span(), vec!["array", "boxed_slice"]); | 
|  | 45 | +                    continue; | 
|  | 46 | +                } | 
|  | 47 | +            }; | 
|  | 48 | +            if mem::replace(skip, true) { | 
|  | 49 | +                cx.duplicate_key(arg.span(), key); | 
|  | 50 | +            } | 
|  | 51 | +        } | 
|  | 52 | +        Some(AttributeKind::SkipDuringMethodDispatch { array, boxed_slice, span: cx.attr_span }) | 
|  | 53 | +    } | 
|  | 54 | +} | 
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