1use rustc_ast::attr;
2use rustc_ast::attr::AttributeExt;
3use rustc_errors::Applicability;
4use rustc_lexer::TokenKind;
5use rustc_lint::LateContext;
6use rustc_middle::ty::{AdtDef, TyCtxt};
7use rustc_session::Session;
8use rustc_span::{Span, Symbol};
9use std::str::FromStr;
10use rustc_attr_data_structures::find_attr;
11use crate::source::SpanRangeExt;
12use crate::{sym, tokenize_with_text};
13use rustc_attr_data_structures::AttributeKind;
14
15pub enum DeprecationStatus {
17 Deprecated,
19 Replaced(&'static str),
21 None,
22}
23
24#[rustfmt::skip]
25pub const BUILTIN_ATTRIBUTES: &[(Symbol, DeprecationStatus)] = &[
26 (sym::author, DeprecationStatus::None),
27 (sym::version, DeprecationStatus::None),
28 (sym::cognitive_complexity, DeprecationStatus::None),
29 (sym::cyclomatic_complexity, DeprecationStatus::Replaced("cognitive_complexity")),
30 (sym::dump, DeprecationStatus::None),
31 (sym::msrv, DeprecationStatus::None),
32 (sym::has_significant_drop, DeprecationStatus::None),
35 (sym::format_args, DeprecationStatus::None),
36];
37
38pub struct LimitStack {
39 stack: Vec<u64>,
40}
41
42impl Drop for LimitStack {
43 fn drop(&mut self) {
44 assert_eq!(self.stack.len(), 1);
45 }
46}
47
48impl LimitStack {
49 #[must_use]
50 pub fn new(limit: u64) -> Self {
51 Self { stack: vec![limit] }
52 }
53 pub fn limit(&self) -> u64 {
54 *self.stack.last().expect("there should always be a value in the stack")
55 }
56 pub fn push_attrs(&mut self, sess: &Session, attrs: &[impl AttributeExt], name: Symbol) {
57 let stack = &mut self.stack;
58 parse_attrs(sess, attrs, name, |val| stack.push(val));
59 }
60 pub fn pop_attrs(&mut self, sess: &Session, attrs: &[impl AttributeExt], name: Symbol) {
61 let stack = &mut self.stack;
62 parse_attrs(sess, attrs, name, |val| assert_eq!(stack.pop(), Some(val)));
63 }
64}
65
66pub fn get_attr<'a, A: AttributeExt + 'a>(
67 sess: &'a Session,
68 attrs: &'a [A],
69 name: Symbol,
70) -> impl Iterator<Item = &'a A> {
71 attrs.iter().filter(move |attr| {
72 let Some(attr_segments) = attr.ident_path() else {
73 return false;
74 };
75
76 if attr_segments.len() == 2 && attr_segments[0].name == sym::clippy {
77 BUILTIN_ATTRIBUTES
78 .iter()
79 .find_map(|(builtin_name, deprecation_status)| {
80 if attr_segments[1].name == *builtin_name {
81 Some(deprecation_status)
82 } else {
83 None
84 }
85 })
86 .map_or_else(
87 || {
88 sess.dcx().span_err(attr_segments[1].span, "usage of unknown attribute");
89 false
90 },
91 |deprecation_status| {
92 let mut diag = sess
93 .dcx()
94 .struct_span_err(attr_segments[1].span, "usage of deprecated attribute");
95 match *deprecation_status {
96 DeprecationStatus::Deprecated => {
97 diag.emit();
98 false
99 },
100 DeprecationStatus::Replaced(new_name) => {
101 diag.span_suggestion(
102 attr_segments[1].span,
103 "consider using",
104 new_name,
105 Applicability::MachineApplicable,
106 );
107 diag.emit();
108 false
109 },
110 DeprecationStatus::None => {
111 diag.cancel();
112 attr_segments[1].name == name
113 },
114 }
115 },
116 )
117 } else {
118 false
119 }
120 })
121}
122
123fn parse_attrs<F: FnMut(u64)>(sess: &Session, attrs: &[impl AttributeExt], name: Symbol, mut f: F) {
124 for attr in get_attr(sess, attrs, name) {
125 if let Some(value) = attr.value_str() {
126 if let Ok(value) = FromStr::from_str(value.as_str()) {
127 f(value);
128 } else {
129 sess.dcx().span_err(attr.span(), "not a number");
130 }
131 } else {
132 sess.dcx().span_err(attr.span(), "bad clippy attribute");
133 }
134 }
135}
136
137pub fn get_unique_attr<'a, A: AttributeExt>(sess: &'a Session, attrs: &'a [A], name: Symbol) -> Option<&'a A> {
138 let mut unique_attr: Option<&A> = None;
139 for attr in get_attr(sess, attrs, name) {
140 if let Some(duplicate) = unique_attr {
141 sess.dcx()
142 .struct_span_err(attr.span(), format!("`{name}` is defined multiple times"))
143 .with_span_note(duplicate.span(), "first definition found here")
144 .emit();
145 } else {
146 unique_attr = Some(attr);
147 }
148 }
149 unique_attr
150}
151
152pub fn is_proc_macro(attrs: &[impl AttributeExt]) -> bool {
155 attrs.iter().any(AttributeExt::is_proc_macro_attr)
156}
157
158pub fn is_doc_hidden(attrs: &[impl AttributeExt]) -> bool {
160 attrs
161 .iter()
162 .filter(|attr| attr.has_name(sym::doc))
163 .filter_map(AttributeExt::meta_item_list)
164 .any(|l| attr::list_contains_name(&l, sym::hidden))
165}
166
167pub fn has_non_exhaustive_attr(tcx: TyCtxt<'_>, adt: AdtDef<'_>) -> bool {
168 adt.is_variant_list_non_exhaustive()
169 || find_attr!(tcx.get_all_attrs(adt.did()), AttributeKind::NonExhaustive(..))
170 || adt.variants().iter().any(|variant_def| {
171 variant_def.is_field_list_non_exhaustive() || find_attr!(tcx.get_all_attrs(variant_def.def_id), AttributeKind::NonExhaustive(..))
172 })
173 || adt
174 .all_fields()
175 .any(|field_def| find_attr!(tcx.get_all_attrs(field_def.did), AttributeKind::NonExhaustive(..)))
176}
177
178pub fn span_contains_cfg(cx: &LateContext<'_>, s: Span) -> bool {
180 s.check_source_text(cx, |src| {
181 let mut iter = tokenize_with_text(src);
182
183 while iter.any(|(t, ..)| matches!(t, TokenKind::Pound)) {
185 let mut iter = iter.by_ref().skip_while(|(t, ..)| {
186 matches!(
187 t,
188 TokenKind::Whitespace | TokenKind::LineComment { .. } | TokenKind::BlockComment { .. }
189 )
190 });
191 if matches!(iter.next(), Some((TokenKind::OpenBracket, ..)))
192 && matches!(iter.next(), Some((TokenKind::Ident, "cfg", _)))
193 {
194 return true;
195 }
196 }
197 false
198 })
199}