clippy_utils/
msrvs.rs

1use crate::sym;
2use rustc_ast::Attribute;
3use rustc_ast::attr::AttributeExt;
4use rustc_attr_data_structures::RustcVersion;
5use rustc_attr_parsing::parse_version;
6use rustc_lint::LateContext;
7use rustc_session::Session;
8use rustc_span::Symbol;
9use serde::Deserialize;
10use smallvec::SmallVec;
11use std::iter::once;
12use std::sync::atomic::{AtomicBool, Ordering};
13
14macro_rules! msrv_aliases {
15    ($($major:literal,$minor:literal,$patch:literal {
16        $($name:ident),* $(,)?
17    })*) => {
18        $($(
19        pub const $name: RustcVersion = RustcVersion { major: $major, minor :$minor, patch: $patch };
20        )*)*
21    };
22}
23
24// names may refer to stabilized feature flags or library items
25msrv_aliases! {
26    1,88,0 { LET_CHAINS }
27    1,87,0 { OS_STR_DISPLAY, INT_MIDPOINT, CONST_CHAR_IS_DIGIT }
28    1,85,0 { UINT_FLOAT_MIDPOINT, CONST_SIZE_OF_VAL }
29    1,84,0 { CONST_OPTION_AS_SLICE, MANUAL_DANGLING_PTR }
30    1,83,0 { CONST_EXTERN_FN, CONST_FLOAT_BITS_CONV, CONST_FLOAT_CLASSIFY, CONST_MUT_REFS, CONST_UNWRAP }
31    1,82,0 { IS_NONE_OR, REPEAT_N, RAW_REF_OP }
32    1,81,0 { LINT_REASONS_STABILIZATION, ERROR_IN_CORE, EXPLICIT_SELF_TYPE_ELISION, DURATION_ABS_DIFF }
33    1,80,0 { BOX_INTO_ITER, LAZY_CELL }
34    1,77,0 { C_STR_LITERALS }
35    1,76,0 { PTR_FROM_REF, OPTION_RESULT_INSPECT }
36    1,75,0 { OPTION_AS_SLICE }
37    1,74,0 { REPR_RUST, IO_ERROR_OTHER }
38    1,73,0 { DIV_CEIL }
39    1,71,0 { TUPLE_ARRAY_CONVERSIONS, BUILD_HASHER_HASH_ONE }
40    1,70,0 { OPTION_RESULT_IS_VARIANT_AND, BINARY_HEAP_RETAIN }
41    1,68,0 { PATH_MAIN_SEPARATOR_STR }
42    1,65,0 { LET_ELSE, POINTER_CAST_CONSTNESS }
43    1,63,0 { CLONE_INTO, CONST_SLICE_FROM_REF }
44    1,62,0 { BOOL_THEN_SOME, DEFAULT_ENUM_ATTRIBUTE, CONST_EXTERN_C_FN }
45    1,60,0 { ABS_DIFF }
46    1,59,0 { THREAD_LOCAL_CONST_INIT }
47    1,58,0 { FORMAT_ARGS_CAPTURE, PATTERN_TRAIT_CHAR_ARRAY, CONST_RAW_PTR_DEREF }
48    1,57,0 { MAP_WHILE }
49    1,56,0 { CONST_FN_UNION }
50    1,55,0 { SEEK_REWIND }
51    1,54,0 { INTO_KEYS }
52    1,53,0 { OR_PATTERNS, INTEGER_BITS, BTREE_MAP_RETAIN, BTREE_SET_RETAIN, ARRAY_INTO_ITERATOR }
53    1,52,0 { STR_SPLIT_ONCE, REM_EUCLID_CONST }
54    1,51,0 { BORROW_AS_PTR, SEEK_FROM_CURRENT, UNSIGNED_ABS }
55    1,50,0 { BOOL_THEN, CLAMP, SLICE_FILL }
56    1,47,0 { TAU, IS_ASCII_DIGIT_CONST, ARRAY_IMPL_ANY_LEN, SATURATING_SUB_CONST }
57    1,46,0 { CONST_IF_MATCH }
58    1,45,0 { STR_STRIP_PREFIX }
59    1,43,0 { LOG2_10, LOG10_2, NUMERIC_ASSOCIATED_CONSTANTS }
60    1,42,0 { MATCHES_MACRO, SLICE_PATTERNS, PTR_SLICE_RAW_PARTS }
61    1,41,0 { RE_REBALANCING_COHERENCE, RESULT_MAP_OR_ELSE }
62    1,40,0 { MEM_TAKE, NON_EXHAUSTIVE, OPTION_AS_DEREF }
63    1,38,0 { POINTER_CAST, REM_EUCLID }
64    1,37,0 { TYPE_ALIAS_ENUM_VARIANTS }
65    1,36,0 { ITERATOR_COPIED }
66    1,35,0 { OPTION_COPIED, RANGE_CONTAINS }
67    1,34,0 { TRY_FROM }
68    1,33,0 { UNDERSCORE_IMPORTS }
69    1,32,0 { CONST_IS_POWER_OF_TWO }
70    1,31,0 { OPTION_REPLACE }
71    1,30,0 { ITERATOR_FIND_MAP, TOOL_ATTRIBUTES }
72    1,29,0 { ITER_FLATTEN }
73    1,28,0 { FROM_BOOL, REPEAT_WITH, SLICE_FROM_REF }
74    1,27,0 { ITERATOR_TRY_FOLD }
75    1,26,0 { RANGE_INCLUSIVE, STRING_RETAIN }
76    1,24,0 { IS_ASCII_DIGIT }
77    1,18,0 { HASH_MAP_RETAIN, HASH_SET_RETAIN }
78    1,17,0 { FIELD_INIT_SHORTHAND, STATIC_IN_CONST, EXPECT_ERR }
79    1,16,0 { STR_REPEAT }
80    1,15,0 { MAYBE_BOUND_IN_WHERE }
81    1,13,0 { QUESTION_MARK_OPERATOR }
82}
83
84/// `#[clippy::msrv]` attributes are rarely used outside of Clippy's test suite, as a basic
85/// optimization we can skip traversing the HIR in [`Msrv::meets`] if we never saw an MSRV attribute
86/// during the early lint passes
87static SEEN_MSRV_ATTR: AtomicBool = AtomicBool::new(false);
88
89/// Tracks the current MSRV from `clippy.toml`, `Cargo.toml` or set via `#[clippy::msrv]` in late
90/// lint passes, use [`MsrvStack`] for early passes
91#[derive(Copy, Clone, Debug, Default)]
92pub struct Msrv(Option<RustcVersion>);
93
94impl<'de> Deserialize<'de> for Msrv {
95    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
96    where
97        D: serde::Deserializer<'de>,
98    {
99        let v = String::deserialize(deserializer)?;
100        parse_version(Symbol::intern(&v))
101            .map(|v| Self(Some(v)))
102            .ok_or_else(|| serde::de::Error::custom("not a valid Rust version"))
103    }
104}
105
106impl Msrv {
107    /// Returns the MSRV at the current node
108    ///
109    /// If the crate being linted uses an `#[clippy::msrv]` attribute this will search the parent
110    /// nodes for that attribute, prefer to run this check after cheaper pattern matching operations
111    pub fn current(self, cx: &LateContext<'_>) -> Option<RustcVersion> {
112        if SEEN_MSRV_ATTR.load(Ordering::Relaxed) {
113            let start = cx.last_node_with_lint_attrs;
114            if let Some(msrv_attr) = once(start)
115                .chain(cx.tcx.hir_parent_id_iter(start))
116                .find_map(|id| parse_attrs(cx.tcx.sess, cx.tcx.hir_attrs(id)))
117            {
118                return Some(msrv_attr);
119            }
120        }
121
122        self.0
123    }
124
125    /// Checks if a required version from [this module](self) is met at the current node
126    ///
127    /// If the crate being linted uses an `#[clippy::msrv]` attribute this will search the parent
128    /// nodes for that attribute, prefer to run this check after cheaper pattern matching operations
129    pub fn meets(self, cx: &LateContext<'_>, required: RustcVersion) -> bool {
130        self.current(cx).is_none_or(|msrv| msrv >= required)
131    }
132
133    pub fn read_cargo(&mut self, sess: &Session) {
134        let cargo_msrv = std::env::var("CARGO_PKG_RUST_VERSION")
135            .ok()
136            .and_then(|v| parse_version(Symbol::intern(&v)));
137
138        match (self.0, cargo_msrv) {
139            (None, Some(cargo_msrv)) => self.0 = Some(cargo_msrv),
140            (Some(clippy_msrv), Some(cargo_msrv)) => {
141                if clippy_msrv != cargo_msrv {
142                    sess.dcx().warn(format!(
143                        "the MSRV in `clippy.toml` and `Cargo.toml` differ; using `{clippy_msrv}` from `clippy.toml`"
144                    ));
145                }
146            },
147            _ => {},
148        }
149    }
150}
151
152/// Tracks the current MSRV from `clippy.toml`, `Cargo.toml` or set via `#[clippy::msrv]` in early
153/// lint passes, use [`Msrv`] for late passes
154#[derive(Debug, Clone)]
155pub struct MsrvStack {
156    stack: SmallVec<[RustcVersion; 2]>,
157}
158
159impl MsrvStack {
160    pub fn new(initial: Msrv) -> Self {
161        Self {
162            stack: SmallVec::from_iter(initial.0),
163        }
164    }
165
166    pub fn current(&self) -> Option<RustcVersion> {
167        self.stack.last().copied()
168    }
169
170    pub fn meets(&self, required: RustcVersion) -> bool {
171        self.current().is_none_or(|msrv| msrv >= required)
172    }
173
174    pub fn check_attributes(&mut self, sess: &Session, attrs: &[Attribute]) {
175        if let Some(version) = parse_attrs(sess, attrs) {
176            SEEN_MSRV_ATTR.store(true, Ordering::Relaxed);
177            self.stack.push(version);
178        }
179    }
180
181    pub fn check_attributes_post(&mut self, sess: &Session, attrs: &[Attribute]) {
182        if parse_attrs(sess, attrs).is_some() {
183            self.stack.pop();
184        }
185    }
186}
187
188fn parse_attrs(sess: &Session, attrs: &[impl AttributeExt]) -> Option<RustcVersion> {
189    let mut msrv_attrs = attrs.iter().filter(|attr| attr.path_matches(&[sym::clippy, sym::msrv]));
190
191    if let Some(msrv_attr) = msrv_attrs.next() {
192        if let Some(duplicate) = msrv_attrs.next_back() {
193            sess.dcx()
194                .struct_span_err(duplicate.span(), "`clippy::msrv` is defined multiple times")
195                .with_span_note(msrv_attr.span(), "first definition found here")
196                .emit();
197        }
198
199        if let Some(msrv) = msrv_attr.value_str() {
200            if let Some(version) = parse_version(msrv) {
201                return Some(version);
202            }
203
204            sess.dcx()
205                .span_err(msrv_attr.span(), format!("`{msrv}` is not a valid Rust version"));
206        } else {
207            sess.dcx().span_err(msrv_attr.span(), "bad clippy attribute");
208        }
209    }
210
211    None
212}
clippy_utils/msrvs.rs

clippy_utils/
msrvs.rs
