rustc_attr_parsing/attributes/
inline.rs

1// FIXME(jdonszelmann): merge these two parsers and error when both attributes are present here.
2//                      note: need to model better how duplicate attr errors work when not using
3//                      SingleAttributeParser which is what we have two of here.
4
5use rustc_hir::attrs::{AttributeKind, InlineAttr};
6
7use super::prelude::*;
8
9pub(crate) struct InlineParser;
10
11impl<S: Stage> SingleAttributeParser<S> for InlineParser {
12    const PATH: &'static [Symbol] = &[sym::inline];
13    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
14    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError;
15    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[
16        Allow(Target::Fn),
17        Allow(Target::Method(MethodKind::Inherent)),
18        Allow(Target::Method(MethodKind::Trait { body: true })),
19        Allow(Target::Method(MethodKind::TraitImpl)),
20        Allow(Target::Closure),
21        Allow(Target::Delegation { mac: false }),
22        Warn(Target::Method(MethodKind::Trait { body: false })),
23        Warn(Target::ForeignFn),
24        Warn(Target::Field),
25        Warn(Target::MacroDef),
26        Warn(Target::Arm),
27        Warn(Target::AssocConst),
28        Warn(Target::MacroCall),
29    ]);
30    const TEMPLATE: AttributeTemplate = template!(
31        Word,
32        List: &["always", "never"],
33        "https://doc.rust-lang.org/reference/attributes/codegen.html#the-inline-attribute"
34    );
35
36    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
37        match args {
38            ArgParser::NoArgs => Some(AttributeKind::Inline(InlineAttr::Hint, cx.attr_span)),
39            ArgParser::List(list) => {
40                let Some(l) = list.single() else {
41                    cx.expected_single_argument(list.span);
42                    return None;
43                };
44
45                match l.meta_item().and_then(|i| i.path().word_sym()) {
46                    Some(sym::always) => {
47                        Some(AttributeKind::Inline(InlineAttr::Always, cx.attr_span))
48                    }
49                    Some(sym::never) => {
50                        Some(AttributeKind::Inline(InlineAttr::Never, cx.attr_span))
51                    }
52                    _ => {
53                        cx.expected_specific_argument(l.span(), &[sym::always, sym::never]);
54                        return None;
55                    }
56                }
57            }
58            ArgParser::NameValue(_) => {
59                let suggestions = <Self as SingleAttributeParser<S>>::TEMPLATE
60                    .suggestions(cx.attr_style, "inline");
61                let span = cx.attr_span;
62                cx.emit_lint(AttributeLintKind::IllFormedAttributeInput { suggestions }, span);
63                return None;
64            }
65        }
66    }
67}
68
69pub(crate) struct RustcForceInlineParser;
70
71impl<S: Stage> SingleAttributeParser<S> for RustcForceInlineParser {
72    const PATH: &'static [Symbol] = &[sym::rustc_force_inline];
73    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
74    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError;
75    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[
76        Allow(Target::Fn),
77        Allow(Target::Method(MethodKind::Inherent)),
78    ]);
79
80    const TEMPLATE: AttributeTemplate = template!(Word, List: &["reason"], NameValueStr: "reason");
81
82    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
83        let reason = match args {
84            ArgParser::NoArgs => None,
85            ArgParser::List(list) => {
86                let Some(l) = list.single() else {
87                    cx.expected_single_argument(list.span);
88                    return None;
89                };
90
91                let Some(reason) = l.lit().and_then(|i| i.kind.str()) else {
92                    cx.expected_string_literal(l.span(), l.lit());
93                    return None;
94                };
95
96                Some(reason)
97            }
98            ArgParser::NameValue(v) => {
99                let Some(reason) = v.value_as_str() else {
100                    cx.expected_string_literal(v.value_span, Some(v.value_as_lit()));
101                    return None;
102                };
103
104                Some(reason)
105            }
106        };
107
108        Some(AttributeKind::Inline(
109            InlineAttr::Force { attr_span: cx.attr_span, reason },
110            cx.attr_span,
111        ))
112    }
113}