clippy_utils/
msrvs.rs

1use crate::sym;
2use rustc_ast::Attribute;
3use rustc_ast::attr::AttributeExt;
4use rustc_attr_parsing::parse_version;
5use rustc_data_structures::smallvec::SmallVec;
6use rustc_hir::attrs::RustcVersion;
7use rustc_hir::def_id::DefId;
8use rustc_hir::{HirId, StabilityLevel, StableSince};
9use rustc_lint::LateContext;
10use rustc_middle::ty::TyCtxt;
11use rustc_session::Session;
12use std::iter::once;
13use std::sync::atomic::{AtomicBool, Ordering};
14
15macro_rules! msrv_aliases {
16    ($($major:literal,$minor:literal,$patch:literal {
17        $($name:ident),* $(,)?
18    })*) => {
19        $($(
20        pub const $name: RustcVersion = RustcVersion { major: $major, minor :$minor, patch: $patch };
21        )*)*
22    };
23}
24
25// names may refer to stabilized feature flags or library items
26msrv_aliases! {
27    1,97,0 { ISOLATE_LOWEST_ONE, BIT_WIDTH }
28    1,94,0 { EULER_GAMMA, GOLDEN_RATIO }
29    1,93,0 { VEC_DEQUE_POP_BACK_IF, VEC_DEQUE_POP_FRONT_IF }
30    1,91,0 { DURATION_FROM_MINUTES_HOURS }
31    1,89,0 { NONNULL_FROM_MUT }
32    1,88,0 { LET_CHAINS, AS_CHUNKS, RAW_PTR_DEFAULT }
33    1,87,0 { OS_STR_DISPLAY, INT_MIDPOINT, CONST_CHAR_IS_DIGIT, UNSIGNED_IS_MULTIPLE_OF, INTEGER_SIGN_CAST }
34    1,86,0 { VEC_POP_IF }
35    1,85,0 { UINT_FLOAT_MIDPOINT, CONST_SIZE_OF_VAL, WAKER_NOOP }
36    1,84,0 { CONST_OPTION_AS_SLICE, MANUAL_DANGLING_PTR }
37    1,83,0 { CONST_EXTERN_FN, CONST_FLOAT_BITS_CONV, CONST_FLOAT_CLASSIFY, CONST_MUT_REFS, CONST_UNWRAP }
38    1,82,0 { IS_NONE_OR, REPEAT_N, RAW_REF_OP, SPECIALIZED_TO_STRING_FOR_REFS }
39    1,81,0 { LINT_REASONS_STABILIZATION, ERROR_IN_CORE, EXPLICIT_SELF_TYPE_ELISION, DURATION_ABS_DIFF }
40    1,80,0 { BOX_INTO_ITER, LAZY_CELL }
41    1,79,0 { CONST_BLOCKS, CSTR_COUNT_BYTES }
42    1,77,0 { C_STR_LITERALS }
43    1,76,0 { PTR_FROM_REF, OPTION_RESULT_INSPECT }
44    1,75,0 { OPTION_AS_SLICE }
45    1,74,0 { REPR_RUST, IO_ERROR_OTHER }
46    1,73,0 { DIV_CEIL }
47    1,71,0 { TUPLE_ARRAY_CONVERSIONS, BUILD_HASHER_HASH_ONE }
48    1,70,0 { OPTION_RESULT_IS_VARIANT_AND, BINARY_HEAP_RETAIN }
49    1,68,0 { PATH_MAIN_SEPARATOR_STR }
50    1,67,0 { ILOG2 }
51    1,65,0 { LET_ELSE, POINTER_CAST_CONSTNESS }
52    1,63,0 { CLONE_INTO, CONST_SLICE_FROM_REF }
53    1,62,0 { BOOL_THEN_SOME, DEFAULT_ENUM_ATTRIBUTE, CONST_EXTERN_C_FN }
54    1,61,0 { CONST_FN_TRAIT_BOUND }
55    1,60,0 { ABS_DIFF }
56    1,59,0 { THREAD_LOCAL_CONST_INIT }
57    1,58,0 { FORMAT_ARGS_CAPTURE, PATTERN_TRAIT_CHAR_ARRAY, CONST_RAW_PTR_DEREF }
58    1,57,0 { MAP_WHILE, CONST_PANIC }
59    1,56,0 { CONST_FN_UNION }
60    1,55,0 { SEEK_REWIND }
61    1,54,0 { INTO_KEYS }
62    1,53,0 { OR_PATTERNS, INTEGER_BITS, BTREE_MAP_RETAIN, BTREE_SET_RETAIN, ARRAY_INTO_ITERATOR }
63    1,52,0 { STR_SPLIT_ONCE, REM_EUCLID_CONST }
64    1,51,0 { BORROW_AS_PTR, SEEK_FROM_CURRENT, UNSIGNED_ABS }
65    1,50,0 { BOOL_THEN, CLAMP, SLICE_FILL }
66    1,47,0 { TAU, IS_ASCII_DIGIT_CONST, ARRAY_IMPL_ANY_LEN, SATURATING_SUB_CONST }
67    1,46,0 { CONST_IF_MATCH, OPTION_ZIP }
68    1,45,0 { STR_STRIP_PREFIX }
69    1,43,0 { LOG2_10, LOG10_2, NUMERIC_ASSOCIATED_CONSTANTS }
70    1,42,0 { MATCHES_MACRO, SLICE_PATTERNS, PTR_SLICE_RAW_PARTS }
71    1,41,0 { RE_REBALANCING_COHERENCE, RESULT_MAP_OR, RESULT_MAP_OR_ELSE }
72    1,40,0 { MEM_TAKE, NON_EXHAUSTIVE, OPTION_AS_DEREF }
73    1,38,0 { POINTER_CAST, REM_EUCLID }
74    1,37,0 { TYPE_ALIAS_ENUM_VARIANTS }
75    1,36,0 { ITERATOR_COPIED }
76    1,35,0 { OPTION_COPIED, RANGE_CONTAINS }
77    1,34,0 { TRY_FROM }
78    1,33,0 { UNDERSCORE_IMPORTS }
79    1,32,0 { CONST_IS_POWER_OF_TWO, CONST_DURATION_FROM_NANOS_MICROS_MILLIS_SECS }
80    1,31,0 { OPTION_REPLACE }
81    1,30,0 { ITERATOR_FIND_MAP, TOOL_ATTRIBUTES }
82    1,29,0 { ITER_FLATTEN }
83    1,28,0 { FROM_BOOL, REPEAT_WITH, SLICE_FROM_REF }
84    1,27,0 { ITERATOR_TRY_FOLD, DOUBLE_ENDED_ITERATOR_RFIND, DURATION_FROM_NANOS_MICROS }
85    1,26,0 { RANGE_INCLUSIVE, STRING_RETAIN, POINTER_ADD_SUB_METHODS, BOX_LEAK }
86    1,24,0 { IS_ASCII_DIGIT, PTR_NULL }
87    1,18,0 { HASH_MAP_RETAIN, HASH_SET_RETAIN }
88    1,17,0 { FIELD_INIT_SHORTHAND, STATIC_IN_CONST, EXPECT_ERR }
89    1,16,0 { STR_REPEAT, RESULT_UNWRAP_OR_DEFAULT }
90    1,15,0 { MAYBE_BOUND_IN_WHERE }
91    1,13,0 { QUESTION_MARK_OPERATOR }
92    1,3,0 { DURATION_FROM_MILLIS_SECS }
93}
94
95/// `#[clippy::msrv]` attributes are rarely used outside of Clippy's test suite, as a basic
96/// optimization we can skip traversing the HIR in [`Msrv::meets`] if we never saw an MSRV attribute
97/// during the early lint passes
98static SEEN_MSRV_ATTR: AtomicBool = AtomicBool::new(false);
99
100/// Tracks the current MSRV from `clippy.toml`, `Cargo.toml` or set via `#[clippy::msrv]` in late
101/// lint passes, use [`MsrvStack`] for early passes
102#[derive(Copy, Clone, Debug, Default)]
103pub struct Msrv(Option<RustcVersion>);
104
105impl From<Option<RustcVersion>> for Msrv {
106    #[inline]
107    fn from(value: Option<RustcVersion>) -> Self {
108        Self(value)
109    }
110}
111
112impl Msrv {
113    /// Returns the MSRV at the current node
114    ///
115    /// If the crate being linted uses an `#[clippy::msrv]` attribute this will search the parent
116    /// nodes for that attribute, prefer to run this check after cheaper pattern matching operations
117    pub fn current(self, cx: &LateContext<'_>) -> Option<RustcVersion> {
118        if SEEN_MSRV_ATTR.load(Ordering::Relaxed) {
119            self.for_attrs(cx.tcx, cx.last_node_with_lint_attrs)
120        } else {
121            self.0
122        }
123    }
124
125    /// Returns the MSRV at the specified 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 at(self, tcx: TyCtxt<'_>, node: HirId) -> Option<RustcVersion> {
130        if SEEN_MSRV_ATTR.load(Ordering::Relaxed) {
131            self.for_attrs(tcx, node)
132        } else {
133            self.0
134        }
135    }
136
137    fn for_attrs(self, tcx: TyCtxt<'_>, node: HirId) -> Option<RustcVersion> {
138        once(node)
139            .chain(tcx.hir_parent_id_iter(node))
140            .find_map(|id| parse_attrs(tcx.sess, tcx.hir_attrs(id)))
141            .or(self.0)
142    }
143
144    /// Checks if a required version from [this module](self) is met at the current node
145    ///
146    /// If the crate being linted uses an `#[clippy::msrv]` attribute this will search the parent
147    /// nodes for that attribute, prefer to run this check after cheaper pattern matching operations
148    pub fn meets(self, cx: &LateContext<'_>, required: RustcVersion) -> bool {
149        self.current(cx).is_none_or(|msrv| msrv >= required)
150    }
151    /// Checks if a required version from [this module](self) is met at the specified node
152    ///
153    /// If the crate being linted uses an `#[clippy::msrv]` attribute this will search the parent
154    /// nodes for that attribute, prefer to run this check after cheaper pattern matching operations
155    pub fn meets_at(self, tcx: TyCtxt<'_>, node: HirId, required: RustcVersion) -> bool {
156        self.at(tcx, node).is_none_or(|msrv| msrv >= required)
157    }
158
159    pub fn is_stable(self, cx: &LateContext<'_>, def_id: DefId) -> bool {
160        cx.tcx.lookup_stability(def_id).is_none_or(|stability| {
161            if let StabilityLevel::Stable { since, .. } = stability.level {
162                let version = match since {
163                    StableSince::Version(version) => version,
164                    StableSince::Current => RustcVersion::CURRENT,
165                    StableSince::Err(_) => return false,
166                };
167
168                self.meets(cx, version)
169            } else {
170                // Unstable fn.
171                // FIXME: can we check that the feature is enabled?
172                // Please see https://github.com/rust-lang/rust-clippy/pull/17309#discussion_r3486693263 for false-positive concerns.
173                false
174            }
175        })
176    }
177}
178
179/// Tracks the current MSRV from `clippy.toml`, `Cargo.toml` or set via `#[clippy::msrv]` in early
180/// lint passes, use [`Msrv`] for late passes
181#[derive(Debug, Clone)]
182pub struct MsrvStack {
183    stack: SmallVec<[RustcVersion; 2]>,
184}
185
186impl From<Option<RustcVersion>> for MsrvStack {
187    #[inline]
188    fn from(value: Option<RustcVersion>) -> Self {
189        Self {
190            stack: SmallVec::from_iter(value),
191        }
192    }
193}
194
195impl MsrvStack {
196    pub fn current(&self) -> Option<RustcVersion> {
197        self.stack.last().copied()
198    }
199
200    pub fn meets(&self, required: RustcVersion) -> bool {
201        self.current().is_none_or(|msrv| msrv >= required)
202    }
203
204    pub fn check_attributes(&mut self, sess: &Session, attrs: &[Attribute]) {
205        if let Some(version) = parse_attrs(sess, attrs) {
206            SEEN_MSRV_ATTR.store(true, Ordering::Relaxed);
207            self.stack.push(version);
208        }
209    }
210
211    pub fn check_attributes_post(&mut self, sess: &Session, attrs: &[Attribute]) {
212        if parse_attrs(sess, attrs).is_some() {
213            self.stack.pop();
214        }
215    }
216}
217
218fn parse_attrs(sess: &Session, attrs: &[impl AttributeExt]) -> Option<RustcVersion> {
219    let mut msrv_attrs = attrs.iter().filter(|attr| attr.path_matches(&[sym::clippy, sym::msrv]));
220
221    let msrv_attr = msrv_attrs.next()?;
222
223    if let Some(duplicate) = msrv_attrs.next_back() {
224        sess.dcx()
225            .struct_span_err(duplicate.span(), "`clippy::msrv` is defined multiple times")
226            .with_span_note(msrv_attr.span(), "first definition found here")
227            .emit();
228    }
229
230    let Some(msrv) = msrv_attr.value_str() else {
231        sess.dcx().span_err(msrv_attr.span(), "bad clippy attribute");
232        return None;
233    };
234
235    let Some(version) = parse_version(msrv) else {
236        sess.dcx()
237            .span_err(msrv_attr.span(), format!("`{msrv}` is not a valid Rust version"));
238        return None;
239    };
240
241    Some(version)
242}
clippy_utils/msrvs.rs

clippy_utils/
msrvs.rs
