rustc_attr_parsing/attributes/
deprecation.rs

1use rustc_hir::attrs::{DeprecatedSince, Deprecation};
2use rustc_hir::{RustcVersion, VERSION_PLACEHOLDER};
3
4use super::prelude::*;
5use super::util::parse_version;
6use crate::session_diagnostics::{
7    DeprecatedItemSuggestion, InvalidSince, MissingNote, MissingSince,
8};
9
10fn get<S: Stage>(
11    cx: &mut AcceptContext<'_, '_, S>,
12    name: Symbol,
13    param_span: Span,
14    arg: &ArgParser,
15    item: Option<Symbol>,
16) -> Option<Ident> {
17    if item.is_some() {
18        cx.adcx().duplicate_key(param_span, name);
19        return None;
20    }
21    if let Some(v) = arg.name_value() {
22        if let Some(value_str) = v.value_as_ident() {
23            Some(value_str)
24        } else {
25            cx.adcx().expected_string_literal(v.value_span, Some(&v.value_as_lit()));
26            None
27        }
28    } else {
29        cx.adcx().expected_name_value(param_span, Some(name));
30        None
31    }
32}
33
34pub(crate) struct DeprecatedParser;
35impl<S: Stage> SingleAttributeParser<S> for DeprecatedParser {
36    const PATH: &[Symbol] = &[sym::deprecated];
37    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowListWarnRest(&[
38        Allow(Target::Fn),
39        Allow(Target::Mod),
40        Allow(Target::Struct),
41        Allow(Target::Enum),
42        Allow(Target::Union),
43        Allow(Target::Const),
44        Allow(Target::Static),
45        Allow(Target::MacroDef),
46        Allow(Target::Method(MethodKind::Inherent)),
47        Allow(Target::Method(MethodKind::Trait { body: false })),
48        Allow(Target::Method(MethodKind::Trait { body: true })),
49        Allow(Target::TyAlias),
50        Allow(Target::Use),
51        Allow(Target::ForeignFn),
52        Allow(Target::ForeignStatic),
53        Allow(Target::ForeignTy),
54        Allow(Target::Field),
55        Allow(Target::Trait),
56        Allow(Target::AssocTy),
57        Allow(Target::AssocConst),
58        Allow(Target::Variant),
59        Allow(Target::Impl { of_trait: false }),
60        Allow(Target::Crate),
61        Error(Target::WherePredicate),
62    ]);
63    const TEMPLATE: AttributeTemplate = ::rustc_feature::AttributeTemplate {
    word: true,
    list: Some(&[r#"since = "version""#, r#"note = "reason""#,
                    r#"since = "version", note = "reason""#]),
    one_of: &[],
    name_value_str: Some(&["reason"]),
    docs: None,
}template!(
64        Word,
65        List: &[r#"since = "version""#, r#"note = "reason""#, r#"since = "version", note = "reason""#],
66        NameValueStr: "reason"
67    );
68
69    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser) -> Option<AttributeKind> {
70        let features = cx.features();
71
72        let mut since = None;
73        let mut note: Option<Ident> = None;
74        let mut suggestion = None;
75
76        let is_rustc = features.staged_api();
77
78        match args {
79            ArgParser::NoArgs => {
80                // ok
81            }
82            ArgParser::List(list) => {
83                for param in list.mixed() {
84                    let Some(param) = param.meta_item() else {
85                        cx.adcx().expected_not_literal(param.span());
86                        return None;
87                    };
88
89                    let ident_name = param.path().word_sym();
90
91                    match ident_name {
92                        Some(name @ sym::since) => {
93                            since = Some(get(cx, name, param.span(), param.args(), since)?.name);
94                        }
95                        Some(name @ sym::note) => {
96                            note = Some(get(
97                                cx,
98                                name,
99                                param.span(),
100                                param.args(),
101                                note.map(|ident| ident.name),
102                            )?);
103                        }
104                        Some(name @ sym::suggestion) => {
105                            if !features.deprecated_suggestion() {
106                                cx.emit_err(DeprecatedItemSuggestion {
107                                    span: param.span(),
108                                    is_nightly: cx.sess().is_nightly_build(),
109                                    details: (),
110                                });
111                            }
112
113                            suggestion =
114                                Some(get(cx, name, param.span(), param.args(), suggestion)?.name);
115                        }
116                        _ => {
117                            cx.adcx().expected_specific_argument(
118                                param.span(),
119                                if features.deprecated_suggestion() {
120                                    &[sym::since, sym::note, sym::suggestion]
121                                } else {
122                                    &[sym::since, sym::note]
123                                },
124                            );
125                            return None;
126                        }
127                    }
128                }
129            }
130            ArgParser::NameValue(v) => {
131                let Some(value) = v.value_as_ident() else {
132                    cx.adcx().expected_string_literal(v.value_span, Some(v.value_as_lit()));
133                    return None;
134                };
135                note = Some(value);
136            }
137        }
138
139        let since = if let Some(since) = since {
140            if since.as_str() == "TBD" {
141                DeprecatedSince::Future
142            } else if !is_rustc {
143                DeprecatedSince::NonStandard(since)
144            } else if since.as_str() == VERSION_PLACEHOLDER {
145                DeprecatedSince::RustcVersion(RustcVersion::CURRENT)
146            } else if let Some(version) = parse_version(since) {
147                DeprecatedSince::RustcVersion(version)
148            } else {
149                cx.emit_err(InvalidSince { span: cx.attr_span });
150                DeprecatedSince::Err
151            }
152        } else if is_rustc {
153            cx.emit_err(MissingSince { span: cx.attr_span });
154            DeprecatedSince::Err
155        } else {
156            DeprecatedSince::Unspecified
157        };
158
159        if is_rustc && note.is_none() {
160            cx.emit_err(MissingNote { span: cx.attr_span });
161            return None;
162        }
163
164        Some(AttributeKind::Deprecated {
165            deprecation: Deprecation { since, note, suggestion },
166            span: cx.attr_span,
167        })
168    }
169}
rustc_attr_parsing/attributes/deprecation.rs

rustc_attr_parsing/attributes/
deprecation.rs
