]>
Commit | Line | Data |
---|---|---|
f20569fa | 1 | #![feature(box_patterns)] |
a2a8927a | 2 | #![feature(control_flow_enum)] |
a2a8927a | 3 | #![feature(let_else)] |
5e7ed085 | 4 | #![feature(let_chains)] |
923072b8 | 5 | #![feature(lint_reasons)] |
a2a8927a | 6 | #![feature(once_cell)] |
f20569fa XL |
7 | #![feature(rustc_private)] |
8 | #![recursion_limit = "512"] | |
17df50a5 | 9 | #![cfg_attr(feature = "deny-warnings", deny(warnings))] |
f20569fa | 10 | #![allow(clippy::missing_errors_doc, clippy::missing_panics_doc, clippy::must_use_candidate)] |
17df50a5 XL |
11 | // warn on the same lints as `clippy_lints` |
12 | #![warn(trivial_casts, trivial_numeric_casts)] | |
13 | // warn on lints, that are included in `rust-lang/rust`s bootstrap | |
14 | #![warn(rust_2018_idioms, unused_lifetimes)] | |
15 | // warn on rustc internal lints | |
16 | #![warn(rustc::internal)] | |
f20569fa XL |
17 | |
18 | // FIXME: switch to something more ergonomic here, once available. | |
19 | // (Currently there is no way to opt into sysroot crates without `extern crate`.) | |
20 | extern crate rustc_ast; | |
21 | extern crate rustc_ast_pretty; | |
cdc7bbd5 | 22 | extern crate rustc_attr; |
f20569fa XL |
23 | extern crate rustc_data_structures; |
24 | extern crate rustc_errors; | |
25 | extern crate rustc_hir; | |
26 | extern crate rustc_infer; | |
27 | extern crate rustc_lexer; | |
28 | extern crate rustc_lint; | |
29 | extern crate rustc_middle; | |
f20569fa XL |
30 | extern crate rustc_session; |
31 | extern crate rustc_span; | |
32 | extern crate rustc_target; | |
33 | extern crate rustc_trait_selection; | |
34 | extern crate rustc_typeck; | |
35 | ||
36 | #[macro_use] | |
37 | pub mod sym_helper; | |
38 | ||
f20569fa XL |
39 | pub mod ast_utils; |
40 | pub mod attrs; | |
f20569fa XL |
41 | pub mod comparisons; |
42 | pub mod consts; | |
cdc7bbd5 | 43 | pub mod diagnostics; |
f20569fa XL |
44 | pub mod eager_or_lazy; |
45 | pub mod higher; | |
46 | mod hir_utils; | |
5099ac24 | 47 | pub mod macros; |
cdc7bbd5 | 48 | pub mod msrvs; |
f20569fa XL |
49 | pub mod numeric_literal; |
50 | pub mod paths; | |
51 | pub mod ptr; | |
52 | pub mod qualify_min_const_fn; | |
cdc7bbd5 | 53 | pub mod source; |
3c0e092e | 54 | pub mod str_utils; |
f20569fa | 55 | pub mod sugg; |
cdc7bbd5 | 56 | pub mod ty; |
f20569fa XL |
57 | pub mod usage; |
58 | pub mod visitors; | |
59 | ||
60 | pub use self::attrs::*; | |
923072b8 FG |
61 | pub use self::hir_utils::{ |
62 | both, count_eq, eq_expr_value, hash_expr, hash_stmt, over, HirEqInterExpr, SpanlessEq, SpanlessHash, | |
63 | }; | |
f20569fa | 64 | |
f20569fa XL |
65 | use std::collections::hash_map::Entry; |
66 | use std::hash::BuildHasherDefault; | |
923072b8 | 67 | use std::sync::OnceLock; |
a2a8927a | 68 | use std::sync::{Mutex, MutexGuard}; |
f20569fa XL |
69 | |
70 | use if_chain::if_chain; | |
04454e1e | 71 | use rustc_ast::ast::{self, LitKind}; |
923072b8 | 72 | use rustc_ast::Attribute; |
a2a8927a | 73 | use rustc_data_structures::fx::FxHashMap; |
17df50a5 | 74 | use rustc_data_structures::unhash::UnhashMap; |
f20569fa | 75 | use rustc_hir as hir; |
cdc7bbd5 | 76 | use rustc_hir::def::{DefKind, Res}; |
5099ac24 | 77 | use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, CRATE_DEF_ID}; |
c295e0f8 | 78 | use rustc_hir::hir_id::{HirIdMap, HirIdSet}; |
5099ac24 | 79 | use rustc_hir::intravisit::{walk_expr, FnKind, Visitor}; |
c295e0f8 | 80 | use rustc_hir::LangItem::{OptionNone, ResultErr, ResultOk}; |
f20569fa | 81 | use rustc_hir::{ |
04454e1e | 82 | def, Arm, ArrayLen, BindingAnnotation, Block, BlockCheckMode, Body, Constness, Destination, Expr, ExprKind, FnDecl, |
923072b8 FG |
83 | HirId, Impl, ImplItem, ImplItemKind, IsAsync, Item, ItemKind, LangItem, Local, MatchSource, Mutability, Node, |
84 | Param, Pat, PatKind, Path, PathSegment, PrimTy, QPath, Stmt, StmtKind, TraitItem, TraitItemKind, TraitRef, TyKind, | |
85 | UnOp, | |
f20569fa | 86 | }; |
f20569fa | 87 | use rustc_lint::{LateContext, Level, Lint, LintContext}; |
c295e0f8 | 88 | use rustc_middle::hir::place::PlaceBase; |
cdc7bbd5 | 89 | use rustc_middle::ty as rustc_ty; |
c295e0f8 XL |
90 | use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow}; |
91 | use rustc_middle::ty::binding::BindingMode; | |
04454e1e FG |
92 | use rustc_middle::ty::fast_reject::SimplifiedTypeGen::{ |
93 | ArraySimplifiedType, BoolSimplifiedType, CharSimplifiedType, FloatSimplifiedType, IntSimplifiedType, | |
94 | PtrSimplifiedType, SliceSimplifiedType, StrSimplifiedType, UintSimplifiedType, | |
95 | }; | |
c295e0f8 | 96 | use rustc_middle::ty::{layout::IntegerExt, BorrowKind, DefIdTree, Ty, TyCtxt, TypeAndMut, TypeFoldable, UpvarCapture}; |
04454e1e | 97 | use rustc_middle::ty::{FloatTy, IntTy, UintTy}; |
f20569fa XL |
98 | use rustc_semver::RustcVersion; |
99 | use rustc_session::Session; | |
cdc7bbd5 | 100 | use rustc_span::hygiene::{ExpnKind, MacroKind}; |
f20569fa XL |
101 | use rustc_span::source_map::original_sp; |
102 | use rustc_span::sym; | |
103 | use rustc_span::symbol::{kw, Symbol}; | |
cdc7bbd5 | 104 | use rustc_span::{Span, DUMMY_SP}; |
f20569fa | 105 | use rustc_target::abi::Integer; |
f20569fa XL |
106 | |
107 | use crate::consts::{constant, Constant}; | |
c295e0f8 | 108 | use crate::ty::{can_partially_move_ty, is_copy, is_recursively_primitive_type}; |
a2a8927a | 109 | use crate::visitors::expr_visitor_no_bodies; |
f20569fa XL |
110 | |
111 | pub fn parse_msrv(msrv: &str, sess: Option<&Session>, span: Option<Span>) -> Option<RustcVersion> { | |
112 | if let Ok(version) = RustcVersion::parse(msrv) { | |
113 | return Some(version); | |
114 | } else if let Some(sess) = sess { | |
115 | if let Some(span) = span { | |
116 | sess.span_err(span, &format!("`{}` is not a valid Rust version", msrv)); | |
117 | } | |
118 | } | |
119 | None | |
120 | } | |
121 | ||
923072b8 FG |
122 | pub fn meets_msrv(msrv: Option<RustcVersion>, lint_msrv: RustcVersion) -> bool { |
123 | msrv.map_or(true, |msrv| msrv.meets(lint_msrv)) | |
f20569fa XL |
124 | } |
125 | ||
126 | #[macro_export] | |
127 | macro_rules! extract_msrv_attr { | |
5099ac24 FG |
128 | ($context:ident) => { |
129 | fn enter_lint_attrs(&mut self, cx: &rustc_lint::$context<'_>, attrs: &[rustc_ast::ast::Attribute]) { | |
130 | let sess = rustc_lint::LintContext::sess(cx); | |
131 | match $crate::get_unique_inner_attr(sess, attrs, "msrv") { | |
f20569fa XL |
132 | Some(msrv_attr) => { |
133 | if let Some(msrv) = msrv_attr.value_str() { | |
5099ac24 | 134 | self.msrv = $crate::parse_msrv(&msrv.to_string(), Some(sess), Some(msrv_attr.span)); |
f20569fa | 135 | } else { |
5099ac24 | 136 | sess.span_err(msrv_attr.span, "bad clippy attribute"); |
f20569fa XL |
137 | } |
138 | }, | |
139 | _ => (), | |
140 | } | |
141 | } | |
142 | }; | |
143 | } | |
144 | ||
cdc7bbd5 XL |
145 | /// If the given expression is a local binding, find the initializer expression. |
146 | /// If that initializer expression is another local binding, find its initializer again. | |
147 | /// This process repeats as long as possible (but usually no more than once). Initializer | |
148 | /// expressions with adjustments are ignored. If this is not desired, use [`find_binding_init`] | |
149 | /// instead. | |
150 | /// | |
151 | /// Examples: | |
a2a8927a | 152 | /// ``` |
cdc7bbd5 XL |
153 | /// let abc = 1; |
154 | /// // ^ output | |
155 | /// let def = abc; | |
a2a8927a | 156 | /// dbg!(def); |
cdc7bbd5 XL |
157 | /// // ^^^ input |
158 | /// | |
159 | /// // or... | |
160 | /// let abc = 1; | |
161 | /// let def = abc + 2; | |
162 | /// // ^^^^^^^ output | |
a2a8927a | 163 | /// dbg!(def); |
cdc7bbd5 XL |
164 | /// // ^^^ input |
165 | /// ``` | |
166 | pub fn expr_or_init<'a, 'b, 'tcx: 'b>(cx: &LateContext<'tcx>, mut expr: &'a Expr<'b>) -> &'a Expr<'b> { | |
167 | while let Some(init) = path_to_local(expr) | |
168 | .and_then(|id| find_binding_init(cx, id)) | |
169 | .filter(|init| cx.typeck_results().expr_adjustments(init).is_empty()) | |
170 | { | |
171 | expr = init; | |
172 | } | |
173 | expr | |
174 | } | |
175 | ||
176 | /// Finds the initializer expression for a local binding. Returns `None` if the binding is mutable. | |
177 | /// By only considering immutable bindings, we guarantee that the returned expression represents the | |
178 | /// value of the binding wherever it is referenced. | |
179 | /// | |
180 | /// Example: For `let x = 1`, if the `HirId` of `x` is provided, the `Expr` `1` is returned. | |
181 | /// Note: If you have an expression that references a binding `x`, use `path_to_local` to get the | |
182 | /// canonical binding `HirId`. | |
183 | pub fn find_binding_init<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<&'tcx Expr<'tcx>> { | |
184 | let hir = cx.tcx.hir(); | |
185 | if_chain! { | |
186 | if let Some(Node::Binding(pat)) = hir.find(hir_id); | |
187 | if matches!(pat.kind, PatKind::Binding(BindingAnnotation::Unannotated, ..)); | |
188 | let parent = hir.get_parent_node(hir_id); | |
189 | if let Some(Node::Local(local)) = hir.find(parent); | |
190 | then { | |
191 | return local.init; | |
192 | } | |
193 | } | |
194 | None | |
195 | } | |
196 | ||
f20569fa XL |
197 | /// Returns `true` if the given `NodeId` is inside a constant context |
198 | /// | |
199 | /// # Example | |
200 | /// | |
201 | /// ```rust,ignore | |
202 | /// if in_constant(cx, expr.hir_id) { | |
203 | /// // Do something | |
204 | /// } | |
205 | /// ``` | |
206 | pub fn in_constant(cx: &LateContext<'_>, id: HirId) -> bool { | |
207 | let parent_id = cx.tcx.hir().get_parent_item(id); | |
5099ac24 | 208 | match cx.tcx.hir().get_by_def_id(parent_id) { |
f20569fa XL |
209 | Node::Item(&Item { |
210 | kind: ItemKind::Const(..) | ItemKind::Static(..), | |
211 | .. | |
212 | }) | |
213 | | Node::TraitItem(&TraitItem { | |
214 | kind: TraitItemKind::Const(..), | |
215 | .. | |
216 | }) | |
217 | | Node::ImplItem(&ImplItem { | |
218 | kind: ImplItemKind::Const(..), | |
219 | .. | |
220 | }) | |
221 | | Node::AnonConst(_) => true, | |
222 | Node::Item(&Item { | |
223 | kind: ItemKind::Fn(ref sig, ..), | |
224 | .. | |
225 | }) | |
226 | | Node::ImplItem(&ImplItem { | |
227 | kind: ImplItemKind::Fn(ref sig, _), | |
228 | .. | |
229 | }) => sig.header.constness == Constness::Const, | |
230 | _ => false, | |
231 | } | |
232 | } | |
233 | ||
cdc7bbd5 XL |
234 | /// Checks if a `QPath` resolves to a constructor of a `LangItem`. |
235 | /// For example, use this to check whether a function call or a pattern is `Some(..)`. | |
236 | pub fn is_lang_ctor(cx: &LateContext<'_>, qpath: &QPath<'_>, lang_item: LangItem) -> bool { | |
237 | if let QPath::Resolved(_, path) = qpath { | |
238 | if let Res::Def(DefKind::Ctor(..), ctor_id) = path.res { | |
239 | if let Ok(item_id) = cx.tcx.lang_items().require(lang_item) { | |
04454e1e | 240 | return cx.tcx.parent(ctor_id) == item_id; |
cdc7bbd5 XL |
241 | } |
242 | } | |
243 | } | |
244 | false | |
245 | } | |
246 | ||
94222f64 | 247 | pub fn is_unit_expr(expr: &Expr<'_>) -> bool { |
c295e0f8 XL |
248 | matches!( |
249 | expr.kind, | |
250 | ExprKind::Block( | |
251 | Block { | |
252 | stmts: [], | |
253 | expr: None, | |
254 | .. | |
255 | }, | |
256 | _ | |
257 | ) | ExprKind::Tup([]) | |
258 | ) | |
94222f64 XL |
259 | } |
260 | ||
f20569fa | 261 | /// Checks if given pattern is a wildcard (`_`) |
136023e0 | 262 | pub fn is_wild(pat: &Pat<'_>) -> bool { |
f20569fa XL |
263 | matches!(pat.kind, PatKind::Wild) |
264 | } | |
265 | ||
f20569fa | 266 | /// Checks if the method call given in `expr` belongs to the given trait. |
cdc7bbd5 | 267 | /// This is a deprecated function, consider using [`is_trait_method`]. |
f20569fa XL |
268 | pub fn match_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, path: &[&str]) -> bool { |
269 | let def_id = cx.typeck_results().type_dependent_def_id(expr.hir_id).unwrap(); | |
270 | let trt_id = cx.tcx.trait_of_item(def_id); | |
271 | trt_id.map_or(false, |trt_id| match_def_path(cx, trt_id, path)) | |
272 | } | |
273 | ||
cdc7bbd5 XL |
274 | /// Checks if a method is defined in an impl of a diagnostic item |
275 | pub fn is_diag_item_method(cx: &LateContext<'_>, def_id: DefId, diag_item: Symbol) -> bool { | |
276 | if let Some(impl_did) = cx.tcx.impl_of_method(def_id) { | |
277 | if let Some(adt) = cx.tcx.type_of(impl_did).ty_adt_def() { | |
5e7ed085 | 278 | return cx.tcx.is_diagnostic_item(diag_item, adt.did()); |
cdc7bbd5 XL |
279 | } |
280 | } | |
281 | false | |
282 | } | |
283 | ||
284 | /// Checks if a method is in a diagnostic item trait | |
285 | pub fn is_diag_trait_item(cx: &LateContext<'_>, def_id: DefId, diag_item: Symbol) -> bool { | |
286 | if let Some(trait_did) = cx.tcx.trait_of_item(def_id) { | |
287 | return cx.tcx.is_diagnostic_item(diag_item, trait_did); | |
288 | } | |
289 | false | |
290 | } | |
291 | ||
292 | /// Checks if the method call given in `expr` belongs to the given trait. | |
293 | pub fn is_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, diag_item: Symbol) -> bool { | |
294 | cx.typeck_results() | |
295 | .type_dependent_def_id(expr.hir_id) | |
296 | .map_or(false, |did| is_diag_trait_item(cx, did, diag_item)) | |
f20569fa XL |
297 | } |
298 | ||
94222f64 XL |
299 | /// Checks if the given expression is a path referring an item on the trait |
300 | /// that is marked with the given diagnostic item. | |
301 | /// | |
302 | /// For checking method call expressions instead of path expressions, use | |
303 | /// [`is_trait_method`]. | |
304 | /// | |
305 | /// For example, this can be used to find if an expression like `u64::default` | |
306 | /// refers to an item of the trait `Default`, which is associated with the | |
307 | /// `diag_item` of `sym::Default`. | |
308 | pub fn is_trait_item(cx: &LateContext<'_>, expr: &Expr<'_>, diag_item: Symbol) -> bool { | |
309 | if let hir::ExprKind::Path(ref qpath) = expr.kind { | |
310 | cx.qpath_res(qpath, expr.hir_id) | |
311 | .opt_def_id() | |
312 | .map_or(false, |def_id| is_diag_trait_item(cx, def_id, diag_item)) | |
313 | } else { | |
314 | false | |
315 | } | |
316 | } | |
317 | ||
f20569fa XL |
318 | pub fn last_path_segment<'tcx>(path: &QPath<'tcx>) -> &'tcx PathSegment<'tcx> { |
319 | match *path { | |
17df50a5 XL |
320 | QPath::Resolved(_, path) => path.segments.last().expect("A path must have at least one segment"), |
321 | QPath::TypeRelative(_, seg) => seg, | |
f20569fa XL |
322 | QPath::LangItem(..) => panic!("last_path_segment: lang item has no path segments"), |
323 | } | |
324 | } | |
325 | ||
5099ac24 FG |
326 | pub fn qpath_generic_tys<'tcx>(qpath: &QPath<'tcx>) -> impl Iterator<Item = &'tcx hir::Ty<'tcx>> { |
327 | last_path_segment(qpath) | |
328 | .args | |
329 | .map_or(&[][..], |a| a.args) | |
f20569fa | 330 | .iter() |
5099ac24 FG |
331 | .filter_map(|a| match a { |
332 | hir::GenericArg::Type(ty) => Some(ty), | |
333 | _ => None, | |
f20569fa XL |
334 | }) |
335 | } | |
336 | ||
cdc7bbd5 XL |
337 | /// THIS METHOD IS DEPRECATED and will eventually be removed since it does not match against the |
338 | /// entire path or resolved `DefId`. Prefer using `match_def_path`. Consider getting a `DefId` from | |
339 | /// `QPath::Resolved.1.res.opt_def_id()`. | |
340 | /// | |
f20569fa XL |
341 | /// Matches a `QPath` against a slice of segment string literals. |
342 | /// | |
343 | /// There is also `match_path` if you are dealing with a `rustc_hir::Path` instead of a | |
344 | /// `rustc_hir::QPath`. | |
345 | /// | |
346 | /// # Examples | |
347 | /// ```rust,ignore | |
348 | /// match_qpath(path, &["std", "rt", "begin_unwind"]) | |
349 | /// ``` | |
350 | pub fn match_qpath(path: &QPath<'_>, segments: &[&str]) -> bool { | |
351 | match *path { | |
17df50a5 XL |
352 | QPath::Resolved(_, path) => match_path(path, segments), |
353 | QPath::TypeRelative(ty, segment) => match ty.kind { | |
f20569fa XL |
354 | TyKind::Path(ref inner_path) => { |
355 | if let [prefix @ .., end] = segments { | |
356 | if match_qpath(inner_path, prefix) { | |
357 | return segment.ident.name.as_str() == *end; | |
358 | } | |
359 | } | |
360 | false | |
361 | }, | |
362 | _ => false, | |
363 | }, | |
364 | QPath::LangItem(..) => false, | |
365 | } | |
366 | } | |
367 | ||
cdc7bbd5 | 368 | /// If the expression is a path, resolves it to a `DefId` and checks if it matches the given path. |
94222f64 XL |
369 | /// |
370 | /// Please use `is_expr_diagnostic_item` if the target is a diagnostic item. | |
cdc7bbd5 | 371 | pub fn is_expr_path_def_path(cx: &LateContext<'_>, expr: &Expr<'_>, segments: &[&str]) -> bool { |
5099ac24 | 372 | path_def_id(cx, expr).map_or(false, |id| match_def_path(cx, id, segments)) |
cdc7bbd5 XL |
373 | } |
374 | ||
94222f64 XL |
375 | /// If the expression is a path, resolves it to a `DefId` and checks if it matches the given |
376 | /// diagnostic item. | |
377 | pub fn is_expr_diagnostic_item(cx: &LateContext<'_>, expr: &Expr<'_>, diag_item: Symbol) -> bool { | |
5099ac24 | 378 | path_def_id(cx, expr).map_or(false, |id| cx.tcx.is_diagnostic_item(diag_item, id)) |
94222f64 XL |
379 | } |
380 | ||
cdc7bbd5 XL |
381 | /// THIS METHOD IS DEPRECATED and will eventually be removed since it does not match against the |
382 | /// entire path or resolved `DefId`. Prefer using `match_def_path`. Consider getting a `DefId` from | |
383 | /// `QPath::Resolved.1.res.opt_def_id()`. | |
384 | /// | |
f20569fa XL |
385 | /// Matches a `Path` against a slice of segment string literals. |
386 | /// | |
387 | /// There is also `match_qpath` if you are dealing with a `rustc_hir::QPath` instead of a | |
388 | /// `rustc_hir::Path`. | |
389 | /// | |
390 | /// # Examples | |
391 | /// | |
392 | /// ```rust,ignore | |
393 | /// if match_path(&trait_ref.path, &paths::HASH) { | |
394 | /// // This is the `std::hash::Hash` trait. | |
395 | /// } | |
396 | /// | |
397 | /// if match_path(ty_path, &["rustc", "lint", "Lint"]) { | |
398 | /// // This is a `rustc_middle::lint::Lint`. | |
399 | /// } | |
400 | /// ``` | |
401 | pub fn match_path(path: &Path<'_>, segments: &[&str]) -> bool { | |
402 | path.segments | |
403 | .iter() | |
404 | .rev() | |
405 | .zip(segments.iter().rev()) | |
406 | .all(|(a, b)| a.ident.name.as_str() == *b) | |
407 | } | |
408 | ||
f20569fa XL |
409 | /// If the expression is a path to a local, returns the canonical `HirId` of the local. |
410 | pub fn path_to_local(expr: &Expr<'_>) -> Option<HirId> { | |
17df50a5 | 411 | if let ExprKind::Path(QPath::Resolved(None, path)) = expr.kind { |
f20569fa XL |
412 | if let Res::Local(id) = path.res { |
413 | return Some(id); | |
414 | } | |
415 | } | |
416 | None | |
417 | } | |
418 | ||
419 | /// Returns true if the expression is a path to a local with the specified `HirId`. | |
420 | /// Use this function to see if an expression matches a function argument or a match binding. | |
421 | pub fn path_to_local_id(expr: &Expr<'_>, id: HirId) -> bool { | |
422 | path_to_local(expr) == Some(id) | |
423 | } | |
424 | ||
5099ac24 FG |
425 | pub trait MaybePath<'hir> { |
426 | fn hir_id(&self) -> HirId; | |
427 | fn qpath_opt(&self) -> Option<&QPath<'hir>>; | |
428 | } | |
429 | ||
430 | macro_rules! maybe_path { | |
431 | ($ty:ident, $kind:ident) => { | |
432 | impl<'hir> MaybePath<'hir> for hir::$ty<'hir> { | |
433 | fn hir_id(&self) -> HirId { | |
434 | self.hir_id | |
435 | } | |
436 | fn qpath_opt(&self) -> Option<&QPath<'hir>> { | |
437 | match &self.kind { | |
438 | hir::$kind::Path(qpath) => Some(qpath), | |
439 | _ => None, | |
440 | } | |
441 | } | |
442 | } | |
443 | }; | |
444 | } | |
445 | maybe_path!(Expr, ExprKind); | |
446 | maybe_path!(Pat, PatKind); | |
447 | maybe_path!(Ty, TyKind); | |
448 | ||
449 | /// If `maybe_path` is a path node, resolves it, otherwise returns `Res::Err` | |
450 | pub fn path_res<'tcx>(cx: &LateContext<'_>, maybe_path: &impl MaybePath<'tcx>) -> Res { | |
451 | match maybe_path.qpath_opt() { | |
452 | None => Res::Err, | |
453 | Some(qpath) => cx.qpath_res(qpath, maybe_path.hir_id()), | |
454 | } | |
455 | } | |
456 | ||
457 | /// If `maybe_path` is a path node which resolves to an item, retrieves the item ID | |
458 | pub fn path_def_id<'tcx>(cx: &LateContext<'_>, maybe_path: &impl MaybePath<'tcx>) -> Option<DefId> { | |
459 | path_res(cx, maybe_path).opt_def_id() | |
460 | } | |
461 | ||
462 | /// Resolves a def path like `std::vec::Vec`. | |
463 | /// This function is expensive and should be used sparingly. | |
464 | pub fn def_path_res(cx: &LateContext<'_>, path: &[&str]) -> Res { | |
5099ac24 FG |
465 | fn item_child_by_name(tcx: TyCtxt<'_>, def_id: DefId, name: &str) -> Option<Res> { |
466 | match tcx.def_kind(def_id) { | |
467 | DefKind::Mod | DefKind::Enum | DefKind::Trait => tcx | |
468 | .module_children(def_id) | |
469 | .iter() | |
470 | .find(|item| item.ident.name.as_str() == name) | |
471 | .map(|child| child.res.expect_non_local()), | |
472 | DefKind::Impl => tcx | |
473 | .associated_item_def_ids(def_id) | |
474 | .iter() | |
475 | .copied() | |
476 | .find(|assoc_def_id| tcx.item_name(*assoc_def_id).as_str() == name) | |
477 | .map(|assoc_def_id| Res::Def(tcx.def_kind(assoc_def_id), assoc_def_id)), | |
478 | _ => None, | |
479 | } | |
480 | } | |
5e7ed085 FG |
481 | fn find_primitive<'tcx>(tcx: TyCtxt<'tcx>, name: &str) -> impl Iterator<Item = DefId> + 'tcx { |
482 | let single = |ty| tcx.incoherent_impls(ty).iter().copied(); | |
483 | let empty = || [].iter().copied(); | |
484 | match name { | |
485 | "bool" => single(BoolSimplifiedType), | |
486 | "char" => single(CharSimplifiedType), | |
487 | "str" => single(StrSimplifiedType), | |
488 | "array" => single(ArraySimplifiedType), | |
489 | "slice" => single(SliceSimplifiedType), | |
490 | // FIXME: rustdoc documents these two using just `pointer`. | |
491 | // | |
492 | // Maybe this is something we should do here too. | |
493 | "const_ptr" => single(PtrSimplifiedType(Mutability::Not)), | |
494 | "mut_ptr" => single(PtrSimplifiedType(Mutability::Mut)), | |
495 | "isize" => single(IntSimplifiedType(IntTy::Isize)), | |
496 | "i8" => single(IntSimplifiedType(IntTy::I8)), | |
497 | "i16" => single(IntSimplifiedType(IntTy::I16)), | |
498 | "i32" => single(IntSimplifiedType(IntTy::I32)), | |
499 | "i64" => single(IntSimplifiedType(IntTy::I64)), | |
500 | "i128" => single(IntSimplifiedType(IntTy::I128)), | |
501 | "usize" => single(UintSimplifiedType(UintTy::Usize)), | |
502 | "u8" => single(UintSimplifiedType(UintTy::U8)), | |
503 | "u16" => single(UintSimplifiedType(UintTy::U16)), | |
504 | "u32" => single(UintSimplifiedType(UintTy::U32)), | |
505 | "u64" => single(UintSimplifiedType(UintTy::U64)), | |
506 | "u128" => single(UintSimplifiedType(UintTy::U128)), | |
507 | "f32" => single(FloatSimplifiedType(FloatTy::F32)), | |
508 | "f64" => single(FloatSimplifiedType(FloatTy::F64)), | |
509 | _ => empty(), | |
5099ac24 FG |
510 | } |
511 | } | |
512 | fn find_crate(tcx: TyCtxt<'_>, name: &str) -> Option<DefId> { | |
513 | tcx.crates(()) | |
f20569fa | 514 | .iter() |
5e7ed085 FG |
515 | .copied() |
516 | .find(|&num| tcx.crate_name(num).as_str() == name) | |
5099ac24 | 517 | .map(CrateNum::as_def_id) |
f20569fa XL |
518 | } |
519 | ||
5099ac24 FG |
520 | let (base, first, path) = match *path { |
521 | [base, first, ref path @ ..] => (base, first, path), | |
94222f64 XL |
522 | [primitive] => { |
523 | return PrimTy::from_name(Symbol::intern(primitive)).map_or(Res::Err, Res::PrimTy); | |
524 | }, | |
f20569fa XL |
525 | _ => return Res::Err, |
526 | }; | |
527 | let tcx = cx.tcx; | |
5e7ed085 FG |
528 | let starts = find_primitive(tcx, base) |
529 | .chain(find_crate(tcx, base)) | |
04454e1e | 530 | .filter_map(|id| item_child_by_name(tcx, id, first)); |
5099ac24 | 531 | |
5e7ed085 FG |
532 | for first in starts { |
533 | let last = path | |
534 | .iter() | |
535 | .copied() | |
536 | // for each segment, find the child item | |
537 | .try_fold(first, |res, segment| { | |
538 | let def_id = res.def_id(); | |
539 | if let Some(item) = item_child_by_name(tcx, def_id, segment) { | |
540 | Some(item) | |
541 | } else if matches!(res, Res::Def(DefKind::Enum | DefKind::Struct, _)) { | |
542 | // it is not a child item so check inherent impl items | |
543 | tcx.inherent_impls(def_id) | |
544 | .iter() | |
545 | .find_map(|&impl_def_id| item_child_by_name(tcx, impl_def_id, segment)) | |
546 | } else { | |
547 | None | |
548 | } | |
549 | }); | |
550 | ||
551 | if let Some(last) = last { | |
552 | return last; | |
553 | } | |
554 | } | |
555 | ||
556 | Res::Err | |
f20569fa XL |
557 | } |
558 | ||
559 | /// Convenience function to get the `DefId` of a trait by path. | |
560 | /// It could be a trait or trait alias. | |
561 | pub fn get_trait_def_id(cx: &LateContext<'_>, path: &[&str]) -> Option<DefId> { | |
5099ac24 | 562 | match def_path_res(cx, path) { |
f20569fa XL |
563 | Res::Def(DefKind::Trait | DefKind::TraitAlias, trait_id) => Some(trait_id), |
564 | _ => None, | |
565 | } | |
566 | } | |
567 | ||
f20569fa XL |
568 | /// Gets the `hir::TraitRef` of the trait the given method is implemented for. |
569 | /// | |
570 | /// Use this if you want to find the `TraitRef` of the `Add` trait in this example: | |
571 | /// | |
572 | /// ```rust | |
573 | /// struct Point(isize, isize); | |
574 | /// | |
575 | /// impl std::ops::Add for Point { | |
576 | /// type Output = Self; | |
577 | /// | |
578 | /// fn add(self, other: Self) -> Self { | |
579 | /// Point(0, 0) | |
580 | /// } | |
581 | /// } | |
582 | /// ``` | |
5099ac24 | 583 | pub fn trait_ref_of_method<'tcx>(cx: &LateContext<'tcx>, def_id: LocalDefId) -> Option<&'tcx TraitRef<'tcx>> { |
f20569fa | 584 | // Get the implemented trait for the current function |
5099ac24 | 585 | let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def_id); |
f20569fa XL |
586 | let parent_impl = cx.tcx.hir().get_parent_item(hir_id); |
587 | if_chain! { | |
5099ac24 FG |
588 | if parent_impl != CRATE_DEF_ID; |
589 | if let hir::Node::Item(item) = cx.tcx.hir().get_by_def_id(parent_impl); | |
f20569fa | 590 | if let hir::ItemKind::Impl(impl_) = &item.kind; |
5099ac24 FG |
591 | then { |
592 | return impl_.of_trait.as_ref(); | |
593 | } | |
f20569fa XL |
594 | } |
595 | None | |
596 | } | |
597 | ||
94222f64 XL |
598 | /// This method will return tuple of projection stack and root of the expression, |
599 | /// used in `can_mut_borrow_both`. | |
600 | /// | |
601 | /// For example, if `e` represents the `v[0].a.b[x]` | |
602 | /// this method will return a tuple, composed of a `Vec` | |
603 | /// containing the `Expr`s for `v[0], v[0].a, v[0].a.b, v[0].a.b[x]` | |
604 | /// and an `Expr` for root of them, `v` | |
605 | fn projection_stack<'a, 'hir>(mut e: &'a Expr<'hir>) -> (Vec<&'a Expr<'hir>>, &'a Expr<'hir>) { | |
606 | let mut result = vec![]; | |
607 | let root = loop { | |
608 | match e.kind { | |
609 | ExprKind::Index(ep, _) | ExprKind::Field(ep, _) => { | |
610 | result.push(e); | |
611 | e = ep; | |
612 | }, | |
613 | _ => break e, | |
614 | }; | |
615 | }; | |
616 | result.reverse(); | |
617 | (result, root) | |
618 | } | |
619 | ||
5099ac24 FG |
620 | /// Gets the mutability of the custom deref adjustment, if any. |
621 | pub fn expr_custom_deref_adjustment(cx: &LateContext<'_>, e: &Expr<'_>) -> Option<Mutability> { | |
622 | cx.typeck_results() | |
623 | .expr_adjustments(e) | |
624 | .iter() | |
625 | .find_map(|a| match a.kind { | |
626 | Adjust::Deref(Some(d)) => Some(Some(d.mutbl)), | |
627 | Adjust::Deref(None) => None, | |
628 | _ => Some(None), | |
629 | }) | |
630 | .and_then(|x| x) | |
631 | } | |
632 | ||
94222f64 XL |
633 | /// Checks if two expressions can be mutably borrowed simultaneously |
634 | /// and they aren't dependent on borrowing same thing twice | |
635 | pub fn can_mut_borrow_both(cx: &LateContext<'_>, e1: &Expr<'_>, e2: &Expr<'_>) -> bool { | |
636 | let (s1, r1) = projection_stack(e1); | |
637 | let (s2, r2) = projection_stack(e2); | |
638 | if !eq_expr_value(cx, r1, r2) { | |
639 | return true; | |
640 | } | |
5099ac24 FG |
641 | if expr_custom_deref_adjustment(cx, r1).is_some() || expr_custom_deref_adjustment(cx, r2).is_some() { |
642 | return false; | |
643 | } | |
644 | ||
94222f64 | 645 | for (x1, x2) in s1.iter().zip(s2.iter()) { |
5099ac24 FG |
646 | if expr_custom_deref_adjustment(cx, x1).is_some() || expr_custom_deref_adjustment(cx, x2).is_some() { |
647 | return false; | |
648 | } | |
649 | ||
94222f64 XL |
650 | match (&x1.kind, &x2.kind) { |
651 | (ExprKind::Field(_, i1), ExprKind::Field(_, i2)) => { | |
652 | if i1 != i2 { | |
653 | return true; | |
654 | } | |
655 | }, | |
656 | (ExprKind::Index(_, i1), ExprKind::Index(_, i2)) => { | |
657 | if !eq_expr_value(cx, i1, i2) { | |
658 | return false; | |
659 | } | |
660 | }, | |
661 | _ => return false, | |
662 | } | |
663 | } | |
664 | false | |
665 | } | |
666 | ||
c295e0f8 XL |
667 | /// Returns true if the `def_id` associated with the `path` is recognized as a "default-equivalent" |
668 | /// constructor from the std library | |
669 | fn is_default_equivalent_ctor(cx: &LateContext<'_>, def_id: DefId, path: &QPath<'_>) -> bool { | |
670 | let std_types_symbols = &[ | |
671 | sym::String, | |
672 | sym::Vec, | |
673 | sym::VecDeque, | |
674 | sym::LinkedList, | |
675 | sym::HashMap, | |
676 | sym::BTreeMap, | |
677 | sym::HashSet, | |
678 | sym::BTreeSet, | |
679 | sym::BinaryHeap, | |
680 | ]; | |
681 | ||
682 | if let QPath::TypeRelative(_, method) = path { | |
683 | if method.ident.name == sym::new { | |
684 | if let Some(impl_did) = cx.tcx.impl_of_method(def_id) { | |
685 | if let Some(adt) = cx.tcx.type_of(impl_did).ty_adt_def() { | |
686 | return std_types_symbols | |
687 | .iter() | |
5e7ed085 | 688 | .any(|&symbol| cx.tcx.is_diagnostic_item(symbol, adt.did())); |
c295e0f8 XL |
689 | } |
690 | } | |
691 | } | |
692 | } | |
693 | false | |
694 | } | |
695 | ||
a2a8927a XL |
696 | /// Return true if the expr is equal to `Default::default` when evaluated. |
697 | pub fn is_default_equivalent_call(cx: &LateContext<'_>, repl_func: &Expr<'_>) -> bool { | |
698 | if_chain! { | |
699 | if let hir::ExprKind::Path(ref repl_func_qpath) = repl_func.kind; | |
700 | if let Some(repl_def_id) = cx.qpath_res(repl_func_qpath, repl_func.hir_id).opt_def_id(); | |
701 | if is_diag_trait_item(cx, repl_def_id, sym::Default) | |
702 | || is_default_equivalent_ctor(cx, repl_def_id, repl_func_qpath); | |
5099ac24 | 703 | then { true } else { false } |
a2a8927a XL |
704 | } |
705 | } | |
706 | ||
c295e0f8 XL |
707 | /// Returns true if the expr is equal to `Default::default()` of it's type when evaluated. |
708 | /// It doesn't cover all cases, for example indirect function calls (some of std | |
709 | /// functions are supported) but it is the best we have. | |
710 | pub fn is_default_equivalent(cx: &LateContext<'_>, e: &Expr<'_>) -> bool { | |
711 | match &e.kind { | |
712 | ExprKind::Lit(lit) => match lit.node { | |
713 | LitKind::Bool(false) | LitKind::Int(0, _) => true, | |
714 | LitKind::Str(s, _) => s.is_empty(), | |
715 | _ => false, | |
716 | }, | |
717 | ExprKind::Tup(items) | ExprKind::Array(items) => items.iter().all(|x| is_default_equivalent(cx, x)), | |
5099ac24 | 718 | ExprKind::Repeat(x, ArrayLen::Body(len)) => if_chain! { |
a2a8927a | 719 | if let ExprKind::Lit(ref const_lit) = cx.tcx.hir().body(len.body).value.kind; |
c295e0f8 XL |
720 | if let LitKind::Int(v, _) = const_lit.node; |
721 | if v <= 32 && is_default_equivalent(cx, x); | |
722 | then { | |
723 | true | |
724 | } | |
725 | else { | |
726 | false | |
727 | } | |
728 | }, | |
a2a8927a | 729 | ExprKind::Call(repl_func, _) => is_default_equivalent_call(cx, repl_func), |
c295e0f8 XL |
730 | ExprKind::Path(qpath) => is_lang_ctor(cx, qpath, OptionNone), |
731 | ExprKind::AddrOf(rustc_hir::BorrowKind::Ref, _, expr) => matches!(expr.kind, ExprKind::Array([])), | |
732 | _ => false, | |
733 | } | |
734 | } | |
735 | ||
cdc7bbd5 | 736 | /// Checks if the top level expression can be moved into a closure as is. |
c295e0f8 XL |
737 | /// Currently checks for: |
738 | /// * Break/Continue outside the given loop HIR ids. | |
3c0e092e | 739 | /// * Yield/Return statements. |
c295e0f8 XL |
740 | /// * Inline assembly. |
741 | /// * Usages of a field of a local where the type of the local can be partially moved. | |
742 | /// | |
743 | /// For example, given the following function: | |
744 | /// | |
745 | /// ``` | |
746 | /// fn f<'a>(iter: &mut impl Iterator<Item = (usize, &'a mut String)>) { | |
747 | /// for item in iter { | |
748 | /// let s = item.1; | |
749 | /// if item.0 > 10 { | |
750 | /// continue; | |
751 | /// } else { | |
752 | /// s.clear(); | |
753 | /// } | |
754 | /// } | |
755 | /// } | |
756 | /// ``` | |
757 | /// | |
758 | /// When called on the expression `item.0` this will return false unless the local `item` is in the | |
759 | /// `ignore_locals` set. The type `(usize, &mut String)` can have the second element moved, so it | |
760 | /// isn't always safe to move into a closure when only a single field is needed. | |
761 | /// | |
762 | /// When called on the `continue` expression this will return false unless the outer loop expression | |
763 | /// is in the `loop_ids` set. | |
764 | /// | |
765 | /// Note that this check is not recursive, so passing the `if` expression will always return true | |
766 | /// even though sub-expressions might return false. | |
5099ac24 | 767 | pub fn can_move_expr_to_closure_no_visit<'tcx>( |
c295e0f8 XL |
768 | cx: &LateContext<'tcx>, |
769 | expr: &'tcx Expr<'_>, | |
770 | loop_ids: &[HirId], | |
771 | ignore_locals: &HirIdSet, | |
772 | ) -> bool { | |
cdc7bbd5 XL |
773 | match expr.kind { |
774 | ExprKind::Break(Destination { target_id: Ok(id), .. }, _) | |
775 | | ExprKind::Continue(Destination { target_id: Ok(id), .. }) | |
c295e0f8 | 776 | if loop_ids.contains(&id) => |
cdc7bbd5 XL |
777 | { |
778 | true | |
779 | }, | |
780 | ExprKind::Break(..) | |
781 | | ExprKind::Continue(_) | |
782 | | ExprKind::Ret(_) | |
783 | | ExprKind::Yield(..) | |
5099ac24 | 784 | | ExprKind::InlineAsm(_) => false, |
cdc7bbd5 XL |
785 | // Accessing a field of a local value can only be done if the type isn't |
786 | // partially moved. | |
c295e0f8 XL |
787 | ExprKind::Field( |
788 | &Expr { | |
789 | hir_id, | |
790 | kind: | |
791 | ExprKind::Path(QPath::Resolved( | |
792 | _, | |
793 | Path { | |
794 | res: Res::Local(local_id), | |
795 | .. | |
796 | }, | |
797 | )), | |
798 | .. | |
799 | }, | |
800 | _, | |
801 | ) if !ignore_locals.contains(local_id) && can_partially_move_ty(cx, cx.typeck_results().node_type(hir_id)) => { | |
cdc7bbd5 XL |
802 | // TODO: check if the local has been partially moved. Assume it has for now. |
803 | false | |
c295e0f8 | 804 | }, |
cdc7bbd5 | 805 | _ => true, |
f20569fa XL |
806 | } |
807 | } | |
808 | ||
c295e0f8 XL |
809 | /// How a local is captured by a closure |
810 | #[derive(Debug, Clone, Copy, PartialEq, Eq)] | |
811 | pub enum CaptureKind { | |
812 | Value, | |
813 | Ref(Mutability), | |
814 | } | |
815 | impl CaptureKind { | |
816 | pub fn is_imm_ref(self) -> bool { | |
817 | self == Self::Ref(Mutability::Not) | |
818 | } | |
819 | } | |
820 | impl std::ops::BitOr for CaptureKind { | |
821 | type Output = Self; | |
822 | fn bitor(self, rhs: Self) -> Self::Output { | |
823 | match (self, rhs) { | |
824 | (CaptureKind::Value, _) | (_, CaptureKind::Value) => CaptureKind::Value, | |
825 | (CaptureKind::Ref(Mutability::Mut), CaptureKind::Ref(_)) | |
826 | | (CaptureKind::Ref(_), CaptureKind::Ref(Mutability::Mut)) => CaptureKind::Ref(Mutability::Mut), | |
827 | (CaptureKind::Ref(Mutability::Not), CaptureKind::Ref(Mutability::Not)) => CaptureKind::Ref(Mutability::Not), | |
828 | } | |
829 | } | |
830 | } | |
831 | impl std::ops::BitOrAssign for CaptureKind { | |
832 | fn bitor_assign(&mut self, rhs: Self) { | |
833 | *self = *self | rhs; | |
834 | } | |
835 | } | |
836 | ||
837 | /// Given an expression referencing a local, determines how it would be captured in a closure. | |
838 | /// Note as this will walk up to parent expressions until the capture can be determined it should | |
839 | /// only be used while making a closure somewhere a value is consumed. e.g. a block, match arm, or | |
840 | /// function argument (other than a receiver). | |
5099ac24 | 841 | pub fn capture_local_usage<'tcx>(cx: &LateContext<'tcx>, e: &Expr<'_>) -> CaptureKind { |
c295e0f8 XL |
842 | fn pat_capture_kind(cx: &LateContext<'_>, pat: &Pat<'_>) -> CaptureKind { |
843 | let mut capture = CaptureKind::Ref(Mutability::Not); | |
844 | pat.each_binding_or_first(&mut |_, id, span, _| match cx | |
845 | .typeck_results() | |
846 | .extract_binding_mode(cx.sess(), id, span) | |
847 | .unwrap() | |
848 | { | |
849 | BindingMode::BindByValue(_) if !is_copy(cx, cx.typeck_results().node_type(id)) => { | |
850 | capture = CaptureKind::Value; | |
851 | }, | |
852 | BindingMode::BindByReference(Mutability::Mut) if capture != CaptureKind::Value => { | |
853 | capture = CaptureKind::Ref(Mutability::Mut); | |
854 | }, | |
855 | _ => (), | |
856 | }); | |
857 | capture | |
858 | } | |
859 | ||
860 | debug_assert!(matches!( | |
861 | e.kind, | |
862 | ExprKind::Path(QPath::Resolved(None, Path { res: Res::Local(_), .. })) | |
863 | )); | |
864 | ||
865 | let mut child_id = e.hir_id; | |
866 | let mut capture = CaptureKind::Value; | |
867 | let mut capture_expr_ty = e; | |
868 | ||
869 | for (parent_id, parent) in cx.tcx.hir().parent_iter(e.hir_id) { | |
870 | if let [ | |
871 | Adjustment { | |
872 | kind: Adjust::Deref(_) | Adjust::Borrow(AutoBorrow::Ref(..)), | |
873 | target, | |
874 | }, | |
875 | ref adjust @ .., | |
876 | ] = *cx | |
877 | .typeck_results() | |
878 | .adjustments() | |
879 | .get(child_id) | |
880 | .map_or(&[][..], |x| &**x) | |
881 | { | |
882 | if let rustc_ty::RawPtr(TypeAndMut { mutbl: mutability, .. }) | rustc_ty::Ref(_, _, mutability) = | |
883 | *adjust.last().map_or(target, |a| a.target).kind() | |
884 | { | |
885 | return CaptureKind::Ref(mutability); | |
886 | } | |
887 | } | |
888 | ||
889 | match parent { | |
890 | Node::Expr(e) => match e.kind { | |
891 | ExprKind::AddrOf(_, mutability, _) => return CaptureKind::Ref(mutability), | |
892 | ExprKind::Index(..) | ExprKind::Unary(UnOp::Deref, _) => capture = CaptureKind::Ref(Mutability::Not), | |
893 | ExprKind::Assign(lhs, ..) | ExprKind::Assign(_, lhs, _) if lhs.hir_id == child_id => { | |
894 | return CaptureKind::Ref(Mutability::Mut); | |
895 | }, | |
896 | ExprKind::Field(..) => { | |
897 | if capture == CaptureKind::Value { | |
898 | capture_expr_ty = e; | |
899 | } | |
900 | }, | |
a2a8927a XL |
901 | ExprKind::Let(let_expr) => { |
902 | let mutability = match pat_capture_kind(cx, let_expr.pat) { | |
c295e0f8 XL |
903 | CaptureKind::Value => Mutability::Not, |
904 | CaptureKind::Ref(m) => m, | |
905 | }; | |
906 | return CaptureKind::Ref(mutability); | |
907 | }, | |
908 | ExprKind::Match(_, arms, _) => { | |
909 | let mut mutability = Mutability::Not; | |
910 | for capture in arms.iter().map(|arm| pat_capture_kind(cx, arm.pat)) { | |
911 | match capture { | |
912 | CaptureKind::Value => break, | |
913 | CaptureKind::Ref(Mutability::Mut) => mutability = Mutability::Mut, | |
914 | CaptureKind::Ref(Mutability::Not) => (), | |
915 | } | |
916 | } | |
917 | return CaptureKind::Ref(mutability); | |
918 | }, | |
919 | _ => break, | |
920 | }, | |
921 | Node::Local(l) => match pat_capture_kind(cx, l.pat) { | |
922 | CaptureKind::Value => break, | |
923 | capture @ CaptureKind::Ref(_) => return capture, | |
924 | }, | |
925 | _ => break, | |
926 | } | |
927 | ||
928 | child_id = parent_id; | |
929 | } | |
930 | ||
931 | if capture == CaptureKind::Value && is_copy(cx, cx.typeck_results().expr_ty(capture_expr_ty)) { | |
932 | // Copy types are never automatically captured by value. | |
933 | CaptureKind::Ref(Mutability::Not) | |
934 | } else { | |
935 | capture | |
936 | } | |
937 | } | |
938 | ||
939 | /// Checks if the expression can be moved into a closure as is. This will return a list of captures | |
940 | /// if so, otherwise, `None`. | |
5099ac24 | 941 | pub fn can_move_expr_to_closure<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<HirIdMap<CaptureKind>> { |
cdc7bbd5 XL |
942 | struct V<'cx, 'tcx> { |
943 | cx: &'cx LateContext<'tcx>, | |
c295e0f8 | 944 | // Stack of potential break targets contained in the expression. |
cdc7bbd5 | 945 | loops: Vec<HirId>, |
c295e0f8 XL |
946 | /// Local variables created in the expression. These don't need to be captured. |
947 | locals: HirIdSet, | |
948 | /// Whether this expression can be turned into a closure. | |
cdc7bbd5 | 949 | allow_closure: bool, |
c295e0f8 XL |
950 | /// Locals which need to be captured, and whether they need to be by value, reference, or |
951 | /// mutable reference. | |
952 | captures: HirIdMap<CaptureKind>, | |
f20569fa | 953 | } |
5099ac24 | 954 | impl<'tcx> Visitor<'tcx> for V<'_, 'tcx> { |
cdc7bbd5 XL |
955 | fn visit_expr(&mut self, e: &'tcx Expr<'_>) { |
956 | if !self.allow_closure { | |
957 | return; | |
958 | } | |
c295e0f8 XL |
959 | |
960 | match e.kind { | |
961 | ExprKind::Path(QPath::Resolved(None, &Path { res: Res::Local(l), .. })) => { | |
962 | if !self.locals.contains(&l) { | |
963 | let cap = capture_local_usage(self.cx, e); | |
964 | self.captures.entry(l).and_modify(|e| *e |= cap).or_insert(cap); | |
965 | } | |
966 | }, | |
923072b8 | 967 | ExprKind::Closure { .. } => { |
c295e0f8 XL |
968 | let closure_id = self.cx.tcx.hir().local_def_id(e.hir_id).to_def_id(); |
969 | for capture in self.cx.typeck_results().closure_min_captures_flattened(closure_id) { | |
970 | let local_id = match capture.place.base { | |
971 | PlaceBase::Local(id) => id, | |
972 | PlaceBase::Upvar(var) => var.var_path.hir_id, | |
973 | _ => continue, | |
974 | }; | |
975 | if !self.locals.contains(&local_id) { | |
976 | let capture = match capture.info.capture_kind { | |
5099ac24 FG |
977 | UpvarCapture::ByValue => CaptureKind::Value, |
978 | UpvarCapture::ByRef(kind) => match kind { | |
c295e0f8 XL |
979 | BorrowKind::ImmBorrow => CaptureKind::Ref(Mutability::Not), |
980 | BorrowKind::UniqueImmBorrow | BorrowKind::MutBorrow => { | |
981 | CaptureKind::Ref(Mutability::Mut) | |
982 | }, | |
983 | }, | |
984 | }; | |
985 | self.captures | |
986 | .entry(local_id) | |
987 | .and_modify(|e| *e |= capture) | |
988 | .or_insert(capture); | |
989 | } | |
990 | } | |
991 | }, | |
992 | ExprKind::Loop(b, ..) => { | |
993 | self.loops.push(e.hir_id); | |
994 | self.visit_block(b); | |
995 | self.loops.pop(); | |
996 | }, | |
997 | _ => { | |
998 | self.allow_closure &= can_move_expr_to_closure_no_visit(self.cx, e, &self.loops, &self.locals); | |
999 | walk_expr(self, e); | |
1000 | }, | |
cdc7bbd5 XL |
1001 | } |
1002 | } | |
c295e0f8 XL |
1003 | |
1004 | fn visit_pat(&mut self, p: &'tcx Pat<'tcx>) { | |
1005 | p.each_binding_or_first(&mut |_, id, _, _| { | |
1006 | self.locals.insert(id); | |
1007 | }); | |
1008 | } | |
f20569fa | 1009 | } |
cdc7bbd5 XL |
1010 | |
1011 | let mut v = V { | |
1012 | cx, | |
1013 | allow_closure: true, | |
1014 | loops: Vec::new(), | |
c295e0f8 XL |
1015 | locals: HirIdSet::default(), |
1016 | captures: HirIdMap::default(), | |
cdc7bbd5 XL |
1017 | }; |
1018 | v.visit_expr(expr); | |
c295e0f8 | 1019 | v.allow_closure.then(|| v.captures) |
f20569fa XL |
1020 | } |
1021 | ||
1022 | /// Returns the method names and argument list of nested method call expressions that make up | |
1023 | /// `expr`. method/span lists are sorted with the most recent call first. | |
1024 | pub fn method_calls<'tcx>( | |
1025 | expr: &'tcx Expr<'tcx>, | |
1026 | max_depth: usize, | |
1027 | ) -> (Vec<Symbol>, Vec<&'tcx [Expr<'tcx>]>, Vec<Span>) { | |
1028 | let mut method_names = Vec::with_capacity(max_depth); | |
1029 | let mut arg_lists = Vec::with_capacity(max_depth); | |
1030 | let mut spans = Vec::with_capacity(max_depth); | |
1031 | ||
1032 | let mut current = expr; | |
1033 | for _ in 0..max_depth { | |
5099ac24 | 1034 | if let ExprKind::MethodCall(path, args, _) = ¤t.kind { |
f20569fa XL |
1035 | if args.iter().any(|e| e.span.from_expansion()) { |
1036 | break; | |
1037 | } | |
1038 | method_names.push(path.ident.name); | |
1039 | arg_lists.push(&**args); | |
5099ac24 | 1040 | spans.push(path.ident.span); |
f20569fa XL |
1041 | current = &args[0]; |
1042 | } else { | |
1043 | break; | |
1044 | } | |
1045 | } | |
1046 | ||
1047 | (method_names, arg_lists, spans) | |
1048 | } | |
1049 | ||
1050 | /// Matches an `Expr` against a chain of methods, and return the matched `Expr`s. | |
1051 | /// | |
1052 | /// For example, if `expr` represents the `.baz()` in `foo.bar().baz()`, | |
1053 | /// `method_chain_args(expr, &["bar", "baz"])` will return a `Vec` | |
1054 | /// containing the `Expr`s for | |
1055 | /// `.bar()` and `.baz()` | |
1056 | pub fn method_chain_args<'a>(expr: &'a Expr<'_>, methods: &[&str]) -> Option<Vec<&'a [Expr<'a>]>> { | |
1057 | let mut current = expr; | |
1058 | let mut matched = Vec::with_capacity(methods.len()); | |
1059 | for method_name in methods.iter().rev() { | |
1060 | // method chains are stored last -> first | |
5099ac24 | 1061 | if let ExprKind::MethodCall(path, args, _) = current.kind { |
f20569fa XL |
1062 | if path.ident.name.as_str() == *method_name { |
1063 | if args.iter().any(|e| e.span.from_expansion()) { | |
1064 | return None; | |
1065 | } | |
17df50a5 XL |
1066 | matched.push(args); // build up `matched` backwards |
1067 | current = &args[0]; // go to parent expression | |
f20569fa XL |
1068 | } else { |
1069 | return None; | |
1070 | } | |
1071 | } else { | |
1072 | return None; | |
1073 | } | |
1074 | } | |
1075 | // Reverse `matched` so that it is in the same order as `methods`. | |
1076 | matched.reverse(); | |
1077 | Some(matched) | |
1078 | } | |
1079 | ||
1080 | /// Returns `true` if the provided `def_id` is an entrypoint to a program. | |
1081 | pub fn is_entrypoint_fn(cx: &LateContext<'_>, def_id: DefId) -> bool { | |
1082 | cx.tcx | |
17df50a5 | 1083 | .entry_fn(()) |
cdc7bbd5 | 1084 | .map_or(false, |(entry_fn_def_id, _)| def_id == entry_fn_def_id) |
f20569fa XL |
1085 | } |
1086 | ||
1087 | /// Returns `true` if the expression is in the program's `#[panic_handler]`. | |
1088 | pub fn is_in_panic_handler(cx: &LateContext<'_>, e: &Expr<'_>) -> bool { | |
1089 | let parent = cx.tcx.hir().get_parent_item(e.hir_id); | |
5099ac24 | 1090 | Some(parent.to_def_id()) == cx.tcx.lang_items().panic_impl() |
f20569fa XL |
1091 | } |
1092 | ||
1093 | /// Gets the name of the item the expression is in, if available. | |
1094 | pub fn get_item_name(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<Symbol> { | |
1095 | let parent_id = cx.tcx.hir().get_parent_item(expr.hir_id); | |
5099ac24 | 1096 | match cx.tcx.hir().find_by_def_id(parent_id) { |
f20569fa XL |
1097 | Some( |
1098 | Node::Item(Item { ident, .. }) | |
1099 | | Node::TraitItem(TraitItem { ident, .. }) | |
1100 | | Node::ImplItem(ImplItem { ident, .. }), | |
1101 | ) => Some(ident.name), | |
1102 | _ => None, | |
1103 | } | |
1104 | } | |
1105 | ||
cdc7bbd5 XL |
1106 | pub struct ContainsName { |
1107 | pub name: Symbol, | |
1108 | pub result: bool, | |
f20569fa XL |
1109 | } |
1110 | ||
1111 | impl<'tcx> Visitor<'tcx> for ContainsName { | |
f20569fa XL |
1112 | fn visit_name(&mut self, _: Span, name: Symbol) { |
1113 | if self.name == name { | |
1114 | self.result = true; | |
1115 | } | |
1116 | } | |
f20569fa XL |
1117 | } |
1118 | ||
1119 | /// Checks if an `Expr` contains a certain name. | |
1120 | pub fn contains_name(name: Symbol, expr: &Expr<'_>) -> bool { | |
1121 | let mut cn = ContainsName { name, result: false }; | |
1122 | cn.visit_expr(expr); | |
1123 | cn.result | |
1124 | } | |
1125 | ||
1126 | /// Returns `true` if `expr` contains a return expression | |
1127 | pub fn contains_return(expr: &hir::Expr<'_>) -> bool { | |
a2a8927a XL |
1128 | let mut found = false; |
1129 | expr_visitor_no_bodies(|expr| { | |
1130 | if !found { | |
f20569fa | 1131 | if let hir::ExprKind::Ret(..) = &expr.kind { |
a2a8927a | 1132 | found = true; |
f20569fa XL |
1133 | } |
1134 | } | |
a2a8927a XL |
1135 | !found |
1136 | }) | |
1137 | .visit_expr(expr); | |
1138 | found | |
f20569fa XL |
1139 | } |
1140 | ||
f20569fa XL |
1141 | /// Extends the span to the beginning of the spans line, incl. whitespaces. |
1142 | /// | |
a2a8927a | 1143 | /// ```rust |
f20569fa XL |
1144 | /// let x = (); |
1145 | /// // ^^ | |
1146 | /// // will be converted to | |
1147 | /// let x = (); | |
1148 | /// // ^^^^^^^^^^^^^^ | |
1149 | /// ``` | |
1150 | fn line_span<T: LintContext>(cx: &T, span: Span) -> Span { | |
1151 | let span = original_sp(span, DUMMY_SP); | |
1152 | let source_map_and_line = cx.sess().source_map().lookup_line(span.lo()).unwrap(); | |
1153 | let line_no = source_map_and_line.line; | |
923072b8 | 1154 | let line_start = source_map_and_line.sf.lines(|lines| lines[line_no]); |
94222f64 | 1155 | span.with_lo(line_start) |
f20569fa XL |
1156 | } |
1157 | ||
cdc7bbd5 XL |
1158 | /// Gets the parent node, if any. |
1159 | pub fn get_parent_node(tcx: TyCtxt<'_>, id: HirId) -> Option<Node<'_>> { | |
1160 | tcx.hir().parent_iter(id).next().map(|(_, node)| node) | |
f20569fa XL |
1161 | } |
1162 | ||
1163 | /// Gets the parent expression, if any –- this is useful to constrain a lint. | |
1164 | pub fn get_parent_expr<'tcx>(cx: &LateContext<'tcx>, e: &Expr<'_>) -> Option<&'tcx Expr<'tcx>> { | |
17df50a5 XL |
1165 | get_parent_expr_for_hir(cx, e.hir_id) |
1166 | } | |
1167 | ||
1168 | /// This retrieves the parent for the given `HirId` if it's an expression. This is useful for | |
1169 | /// constraint lints | |
1170 | pub fn get_parent_expr_for_hir<'tcx>(cx: &LateContext<'tcx>, hir_id: hir::HirId) -> Option<&'tcx Expr<'tcx>> { | |
1171 | match get_parent_node(cx.tcx, hir_id) { | |
cdc7bbd5 XL |
1172 | Some(Node::Expr(parent)) => Some(parent), |
1173 | _ => None, | |
1174 | } | |
f20569fa XL |
1175 | } |
1176 | ||
1177 | pub fn get_enclosing_block<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<&'tcx Block<'tcx>> { | |
1178 | let map = &cx.tcx.hir(); | |
1179 | let enclosing_node = map | |
1180 | .get_enclosing_scope(hir_id) | |
1181 | .and_then(|enclosing_id| map.find(enclosing_id)); | |
1182 | enclosing_node.and_then(|node| match node { | |
1183 | Node::Block(block) => Some(block), | |
1184 | Node::Item(&Item { | |
1185 | kind: ItemKind::Fn(_, _, eid), | |
1186 | .. | |
1187 | }) | |
1188 | | Node::ImplItem(&ImplItem { | |
1189 | kind: ImplItemKind::Fn(_, eid), | |
1190 | .. | |
1191 | }) => match cx.tcx.hir().body(eid).value.kind { | |
17df50a5 | 1192 | ExprKind::Block(block, _) => Some(block), |
f20569fa XL |
1193 | _ => None, |
1194 | }, | |
1195 | _ => None, | |
1196 | }) | |
1197 | } | |
1198 | ||
136023e0 | 1199 | /// Gets the loop or closure enclosing the given expression, if any. |
5099ac24 | 1200 | pub fn get_enclosing_loop_or_closure<'tcx>(tcx: TyCtxt<'tcx>, expr: &Expr<'_>) -> Option<&'tcx Expr<'tcx>> { |
c295e0f8 | 1201 | for (_, node) in tcx.hir().parent_iter(expr.hir_id) { |
17df50a5 XL |
1202 | match node { |
1203 | Node::Expr( | |
c295e0f8 | 1204 | e @ Expr { |
923072b8 | 1205 | kind: ExprKind::Loop(..) | ExprKind::Closure { .. }, |
17df50a5 XL |
1206 | .. |
1207 | }, | |
1208 | ) => return Some(e), | |
1209 | Node::Expr(_) | Node::Stmt(_) | Node::Block(_) | Node::Local(_) | Node::Arm(_) => (), | |
1210 | _ => break, | |
1211 | } | |
1212 | } | |
1213 | None | |
1214 | } | |
1215 | ||
f20569fa XL |
1216 | /// Gets the parent node if it's an impl block. |
1217 | pub fn get_parent_as_impl(tcx: TyCtxt<'_>, id: HirId) -> Option<&Impl<'_>> { | |
c295e0f8 | 1218 | match tcx.hir().parent_iter(id).next() { |
f20569fa XL |
1219 | Some(( |
1220 | _, | |
1221 | Node::Item(Item { | |
1222 | kind: ItemKind::Impl(imp), | |
1223 | .. | |
1224 | }), | |
1225 | )) => Some(imp), | |
1226 | _ => None, | |
1227 | } | |
1228 | } | |
1229 | ||
a2a8927a XL |
1230 | /// Removes blocks around an expression, only if the block contains just one expression |
1231 | /// and no statements. Unsafe blocks are not removed. | |
1232 | /// | |
1233 | /// Examples: | |
1234 | /// * `{}` -> `{}` | |
1235 | /// * `{ x }` -> `x` | |
1236 | /// * `{{ x }}` -> `x` | |
1237 | /// * `{ x; }` -> `{ x; }` | |
1238 | /// * `{ x; y }` -> `{ x; y }` | |
1239 | /// * `{ unsafe { x } }` -> `unsafe { x }` | |
1240 | pub fn peel_blocks<'a>(mut expr: &'a Expr<'a>) -> &'a Expr<'a> { | |
1241 | while let ExprKind::Block( | |
1242 | Block { | |
1243 | stmts: [], | |
1244 | expr: Some(inner), | |
1245 | rules: BlockCheckMode::DefaultBlock, | |
1246 | .. | |
1247 | }, | |
1248 | _, | |
1249 | ) = expr.kind | |
1250 | { | |
1251 | expr = inner; | |
1252 | } | |
1253 | expr | |
1254 | } | |
1255 | ||
1256 | /// Removes blocks around an expression, only if the block contains just one expression | |
1257 | /// or just one expression statement with a semicolon. Unsafe blocks are not removed. | |
1258 | /// | |
1259 | /// Examples: | |
1260 | /// * `{}` -> `{}` | |
1261 | /// * `{ x }` -> `x` | |
1262 | /// * `{ x; }` -> `x` | |
1263 | /// * `{{ x; }}` -> `x` | |
1264 | /// * `{ x; y }` -> `{ x; y }` | |
1265 | /// * `{ unsafe { x } }` -> `unsafe { x }` | |
1266 | pub fn peel_blocks_with_stmt<'a>(mut expr: &'a Expr<'a>) -> &'a Expr<'a> { | |
1267 | while let ExprKind::Block( | |
1268 | Block { | |
1269 | stmts: [], | |
1270 | expr: Some(inner), | |
1271 | rules: BlockCheckMode::DefaultBlock, | |
1272 | .. | |
1273 | } | |
1274 | | Block { | |
1275 | stmts: | |
1276 | [ | |
1277 | Stmt { | |
1278 | kind: StmtKind::Expr(inner) | StmtKind::Semi(inner), | |
1279 | .. | |
1280 | }, | |
1281 | ], | |
1282 | expr: None, | |
1283 | rules: BlockCheckMode::DefaultBlock, | |
1284 | .. | |
1285 | }, | |
1286 | _, | |
1287 | ) = expr.kind | |
1288 | { | |
1289 | expr = inner; | |
1290 | } | |
1291 | expr | |
1292 | } | |
1293 | ||
cdc7bbd5 XL |
1294 | /// Checks if the given expression is the else clause of either an `if` or `if let` expression. |
1295 | pub fn is_else_clause(tcx: TyCtxt<'_>, expr: &Expr<'_>) -> bool { | |
c295e0f8 | 1296 | let mut iter = tcx.hir().parent_iter(expr.hir_id); |
cdc7bbd5 | 1297 | match iter.next() { |
cdc7bbd5 XL |
1298 | Some(( |
1299 | _, | |
1300 | Node::Expr(Expr { | |
1301 | kind: ExprKind::If(_, _, Some(else_expr)), | |
1302 | .. | |
1303 | }), | |
1304 | )) => else_expr.hir_id == expr.hir_id, | |
1305 | _ => false, | |
f20569fa | 1306 | } |
f20569fa XL |
1307 | } |
1308 | ||
1309 | /// Checks whether the given expression is a constant integer of the given value. | |
1310 | /// unlike `is_integer_literal`, this version does const folding | |
1311 | pub fn is_integer_const(cx: &LateContext<'_>, e: &Expr<'_>, value: u128) -> bool { | |
1312 | if is_integer_literal(e, value) { | |
1313 | return true; | |
1314 | } | |
136023e0 XL |
1315 | let enclosing_body = cx.tcx.hir().local_def_id(cx.tcx.hir().enclosing_body_owner(e.hir_id)); |
1316 | if let Some((Constant::Int(v), _)) = constant(cx, cx.tcx.typeck(enclosing_body), e) { | |
3c0e092e | 1317 | return value == v; |
f20569fa | 1318 | } |
3c0e092e | 1319 | false |
f20569fa XL |
1320 | } |
1321 | ||
1322 | /// Checks whether the given expression is a constant literal of the given value. | |
1323 | pub fn is_integer_literal(expr: &Expr<'_>, value: u128) -> bool { | |
1324 | // FIXME: use constant folding | |
1325 | if let ExprKind::Lit(ref spanned) = expr.kind { | |
1326 | if let LitKind::Int(v, _) = spanned.node { | |
1327 | return v == value; | |
1328 | } | |
1329 | } | |
1330 | false | |
1331 | } | |
1332 | ||
1333 | /// Returns `true` if the given `Expr` has been coerced before. | |
1334 | /// | |
1335 | /// Examples of coercions can be found in the Nomicon at | |
1336 | /// <https://doc.rust-lang.org/nomicon/coercions.html>. | |
1337 | /// | |
1338 | /// See `rustc_middle::ty::adjustment::Adjustment` and `rustc_typeck::check::coercion` for more | |
1339 | /// information on adjustments and coercions. | |
1340 | pub fn is_adjusted(cx: &LateContext<'_>, e: &Expr<'_>) -> bool { | |
1341 | cx.typeck_results().adjustments().get(e.hir_id).is_some() | |
1342 | } | |
1343 | ||
a2a8927a | 1344 | /// Returns the pre-expansion span if this comes from an expansion of the |
f20569fa | 1345 | /// macro `name`. |
3c0e092e | 1346 | /// See also [`is_direct_expn_of`]. |
f20569fa XL |
1347 | #[must_use] |
1348 | pub fn is_expn_of(mut span: Span, name: &str) -> Option<Span> { | |
1349 | loop { | |
1350 | if span.from_expansion() { | |
1351 | let data = span.ctxt().outer_expn_data(); | |
1352 | let new_span = data.call_site; | |
1353 | ||
136023e0 | 1354 | if let ExpnKind::Macro(MacroKind::Bang, mac_name) = data.kind { |
f20569fa XL |
1355 | if mac_name.as_str() == name { |
1356 | return Some(new_span); | |
1357 | } | |
1358 | } | |
1359 | ||
1360 | span = new_span; | |
1361 | } else { | |
1362 | return None; | |
1363 | } | |
1364 | } | |
1365 | } | |
1366 | ||
1367 | /// Returns the pre-expansion span if the span directly comes from an expansion | |
1368 | /// of the macro `name`. | |
3c0e092e XL |
1369 | /// The difference with [`is_expn_of`] is that in |
1370 | /// ```rust | |
a2a8927a XL |
1371 | /// # macro_rules! foo { ($name:tt!$args:tt) => { $name!$args } } |
1372 | /// # macro_rules! bar { ($e:expr) => { $e } } | |
f20569fa XL |
1373 | /// foo!(bar!(42)); |
1374 | /// ``` | |
1375 | /// `42` is considered expanded from `foo!` and `bar!` by `is_expn_of` but only | |
3c0e092e | 1376 | /// from `bar!` by `is_direct_expn_of`. |
f20569fa XL |
1377 | #[must_use] |
1378 | pub fn is_direct_expn_of(span: Span, name: &str) -> Option<Span> { | |
1379 | if span.from_expansion() { | |
1380 | let data = span.ctxt().outer_expn_data(); | |
1381 | let new_span = data.call_site; | |
1382 | ||
136023e0 | 1383 | if let ExpnKind::Macro(MacroKind::Bang, mac_name) = data.kind { |
f20569fa XL |
1384 | if mac_name.as_str() == name { |
1385 | return Some(new_span); | |
1386 | } | |
1387 | } | |
1388 | } | |
1389 | ||
1390 | None | |
1391 | } | |
1392 | ||
1393 | /// Convenience function to get the return type of a function. | |
1394 | pub fn return_ty<'tcx>(cx: &LateContext<'tcx>, fn_item: hir::HirId) -> Ty<'tcx> { | |
1395 | let fn_def_id = cx.tcx.hir().local_def_id(fn_item); | |
1396 | let ret_ty = cx.tcx.fn_sig(fn_def_id).output(); | |
1397 | cx.tcx.erase_late_bound_regions(ret_ty) | |
1398 | } | |
1399 | ||
a2a8927a XL |
1400 | /// Convenience function to get the nth argument type of a function. |
1401 | pub fn nth_arg<'tcx>(cx: &LateContext<'tcx>, fn_item: hir::HirId, nth: usize) -> Ty<'tcx> { | |
1402 | let fn_def_id = cx.tcx.hir().local_def_id(fn_item); | |
1403 | let arg = cx.tcx.fn_sig(fn_def_id).input(nth); | |
1404 | cx.tcx.erase_late_bound_regions(arg) | |
1405 | } | |
1406 | ||
f20569fa XL |
1407 | /// Checks if an expression is constructing a tuple-like enum variant or struct |
1408 | pub fn is_ctor_or_promotable_const_function(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { | |
17df50a5 | 1409 | if let ExprKind::Call(fun, _) = expr.kind { |
f20569fa XL |
1410 | if let ExprKind::Path(ref qp) = fun.kind { |
1411 | let res = cx.qpath_res(qp, fun.hir_id); | |
1412 | return match res { | |
1413 | def::Res::Def(DefKind::Variant | DefKind::Ctor(..), ..) => true, | |
1414 | def::Res::Def(_, def_id) => cx.tcx.is_promotable_const_fn(def_id), | |
1415 | _ => false, | |
1416 | }; | |
1417 | } | |
1418 | } | |
1419 | false | |
1420 | } | |
1421 | ||
1422 | /// Returns `true` if a pattern is refutable. | |
1423 | // TODO: should be implemented using rustc/mir_build/thir machinery | |
1424 | pub fn is_refutable(cx: &LateContext<'_>, pat: &Pat<'_>) -> bool { | |
1425 | fn is_enum_variant(cx: &LateContext<'_>, qpath: &QPath<'_>, id: HirId) -> bool { | |
1426 | matches!( | |
1427 | cx.qpath_res(qpath, id), | |
1428 | def::Res::Def(DefKind::Variant, ..) | Res::Def(DefKind::Ctor(def::CtorOf::Variant, _), _) | |
1429 | ) | |
1430 | } | |
1431 | ||
136023e0 XL |
1432 | fn are_refutable<'a, I: IntoIterator<Item = &'a Pat<'a>>>(cx: &LateContext<'_>, i: I) -> bool { |
1433 | i.into_iter().any(|pat| is_refutable(cx, pat)) | |
f20569fa XL |
1434 | } |
1435 | ||
1436 | match pat.kind { | |
1437 | PatKind::Wild => false, | |
1438 | PatKind::Binding(_, _, _, pat) => pat.map_or(false, |pat| is_refutable(cx, pat)), | |
17df50a5 | 1439 | PatKind::Box(pat) | PatKind::Ref(pat, _) => is_refutable(cx, pat), |
f20569fa XL |
1440 | PatKind::Lit(..) | PatKind::Range(..) => true, |
1441 | PatKind::Path(ref qpath) => is_enum_variant(cx, qpath, pat.hir_id), | |
17df50a5 | 1442 | PatKind::Or(pats) => { |
f20569fa | 1443 | // TODO: should be the honest check, that pats is exhaustive set |
136023e0 | 1444 | are_refutable(cx, pats) |
f20569fa | 1445 | }, |
136023e0 | 1446 | PatKind::Tuple(pats, _) => are_refutable(cx, pats), |
17df50a5 | 1447 | PatKind::Struct(ref qpath, fields, _) => { |
923072b8 | 1448 | is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, fields.iter().map(|field| field.pat)) |
f20569fa | 1449 | }, |
136023e0 XL |
1450 | PatKind::TupleStruct(ref qpath, pats, _) => is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, pats), |
1451 | PatKind::Slice(head, middle, tail) => { | |
f20569fa | 1452 | match &cx.typeck_results().node_type(pat.hir_id).kind() { |
cdc7bbd5 | 1453 | rustc_ty::Slice(..) => { |
f20569fa XL |
1454 | // [..] is the only irrefutable slice pattern. |
1455 | !head.is_empty() || middle.is_none() || !tail.is_empty() | |
1456 | }, | |
136023e0 | 1457 | rustc_ty::Array(..) => are_refutable(cx, head.iter().chain(middle).chain(tail.iter())), |
f20569fa XL |
1458 | _ => { |
1459 | // unreachable!() | |
1460 | true | |
1461 | }, | |
1462 | } | |
1463 | }, | |
1464 | } | |
1465 | } | |
1466 | ||
cdc7bbd5 XL |
1467 | /// If the pattern is an `or` pattern, call the function once for each sub pattern. Otherwise, call |
1468 | /// the function once on the given pattern. | |
1469 | pub fn recurse_or_patterns<'tcx, F: FnMut(&'tcx Pat<'tcx>)>(pat: &'tcx Pat<'tcx>, mut f: F) { | |
1470 | if let PatKind::Or(pats) = pat.kind { | |
136023e0 | 1471 | pats.iter().for_each(f); |
cdc7bbd5 | 1472 | } else { |
17df50a5 | 1473 | f(pat); |
cdc7bbd5 XL |
1474 | } |
1475 | } | |
1476 | ||
f20569fa XL |
1477 | pub fn is_self(slf: &Param<'_>) -> bool { |
1478 | if let PatKind::Binding(.., name, _) = slf.pat.kind { | |
1479 | name.name == kw::SelfLower | |
1480 | } else { | |
1481 | false | |
1482 | } | |
1483 | } | |
1484 | ||
1485 | pub fn is_self_ty(slf: &hir::Ty<'_>) -> bool { | |
3c0e092e | 1486 | if let TyKind::Path(QPath::Resolved(None, path)) = slf.kind { |
5099ac24 | 1487 | if let Res::SelfTy { .. } = path.res { |
3c0e092e | 1488 | return true; |
f20569fa XL |
1489 | } |
1490 | } | |
1491 | false | |
1492 | } | |
1493 | ||
1494 | pub fn iter_input_pats<'tcx>(decl: &FnDecl<'_>, body: &'tcx Body<'_>) -> impl Iterator<Item = &'tcx Param<'tcx>> { | |
1495 | (0..decl.inputs.len()).map(move |i| &body.params[i]) | |
1496 | } | |
1497 | ||
1498 | /// Checks if a given expression is a match expression expanded from the `?` | |
1499 | /// operator or the `try` macro. | |
cdc7bbd5 XL |
1500 | pub fn is_try<'tcx>(cx: &LateContext<'_>, expr: &'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> { |
1501 | fn is_ok(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool { | |
f20569fa | 1502 | if_chain! { |
17df50a5 | 1503 | if let PatKind::TupleStruct(ref path, pat, None) = arm.pat.kind; |
cdc7bbd5 | 1504 | if is_lang_ctor(cx, path, ResultOk); |
f20569fa XL |
1505 | if let PatKind::Binding(_, hir_id, _, None) = pat[0].kind; |
1506 | if path_to_local_id(arm.body, hir_id); | |
1507 | then { | |
1508 | return true; | |
1509 | } | |
1510 | } | |
1511 | false | |
1512 | } | |
1513 | ||
cdc7bbd5 | 1514 | fn is_err(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool { |
f20569fa | 1515 | if let PatKind::TupleStruct(ref path, _, _) = arm.pat.kind { |
cdc7bbd5 | 1516 | is_lang_ctor(cx, path, ResultErr) |
f20569fa XL |
1517 | } else { |
1518 | false | |
1519 | } | |
1520 | } | |
1521 | ||
17df50a5 | 1522 | if let ExprKind::Match(_, arms, ref source) = expr.kind { |
f20569fa | 1523 | // desugared from a `?` operator |
c295e0f8 | 1524 | if *source == MatchSource::TryDesugar { |
f20569fa XL |
1525 | return Some(expr); |
1526 | } | |
1527 | ||
1528 | if_chain! { | |
1529 | if arms.len() == 2; | |
1530 | if arms[0].guard.is_none(); | |
1531 | if arms[1].guard.is_none(); | |
5099ac24 | 1532 | if (is_ok(cx, &arms[0]) && is_err(cx, &arms[1])) || (is_ok(cx, &arms[1]) && is_err(cx, &arms[0])); |
f20569fa XL |
1533 | then { |
1534 | return Some(expr); | |
1535 | } | |
1536 | } | |
1537 | } | |
1538 | ||
1539 | None | |
1540 | } | |
1541 | ||
1542 | /// Returns `true` if the lint is allowed in the current context | |
1543 | /// | |
1544 | /// Useful for skipping long running code when it's unnecessary | |
136023e0 | 1545 | pub fn is_lint_allowed(cx: &LateContext<'_>, lint: &'static Lint, id: HirId) -> bool { |
f20569fa XL |
1546 | cx.tcx.lint_level_at_node(lint, id).0 == Level::Allow |
1547 | } | |
1548 | ||
1549 | pub fn strip_pat_refs<'hir>(mut pat: &'hir Pat<'hir>) -> &'hir Pat<'hir> { | |
1550 | while let PatKind::Ref(subpat, _) = pat.kind { | |
1551 | pat = subpat; | |
1552 | } | |
1553 | pat | |
1554 | } | |
1555 | ||
cdc7bbd5 | 1556 | pub fn int_bits(tcx: TyCtxt<'_>, ity: rustc_ty::IntTy) -> u64 { |
f20569fa XL |
1557 | Integer::from_int_ty(&tcx, ity).size().bits() |
1558 | } | |
1559 | ||
923072b8 | 1560 | #[expect(clippy::cast_possible_wrap)] |
f20569fa | 1561 | /// Turn a constant int byte representation into an i128 |
cdc7bbd5 | 1562 | pub fn sext(tcx: TyCtxt<'_>, u: u128, ity: rustc_ty::IntTy) -> i128 { |
f20569fa XL |
1563 | let amt = 128 - int_bits(tcx, ity); |
1564 | ((u as i128) << amt) >> amt | |
1565 | } | |
1566 | ||
923072b8 | 1567 | #[expect(clippy::cast_sign_loss)] |
f20569fa | 1568 | /// clip unused bytes |
cdc7bbd5 | 1569 | pub fn unsext(tcx: TyCtxt<'_>, u: i128, ity: rustc_ty::IntTy) -> u128 { |
f20569fa XL |
1570 | let amt = 128 - int_bits(tcx, ity); |
1571 | ((u as u128) << amt) >> amt | |
1572 | } | |
1573 | ||
1574 | /// clip unused bytes | |
cdc7bbd5 | 1575 | pub fn clip(tcx: TyCtxt<'_>, u: u128, ity: rustc_ty::UintTy) -> u128 { |
f20569fa XL |
1576 | let bits = Integer::from_uint_ty(&tcx, ity).size().bits(); |
1577 | let amt = 128 - bits; | |
1578 | (u << amt) >> amt | |
1579 | } | |
1580 | ||
a2a8927a XL |
1581 | pub fn has_attr(attrs: &[ast::Attribute], symbol: Symbol) -> bool { |
1582 | attrs.iter().any(|attr| attr.has_name(symbol)) | |
1583 | } | |
1584 | ||
1585 | pub fn any_parent_has_attr(tcx: TyCtxt<'_>, node: HirId, symbol: Symbol) -> bool { | |
f20569fa XL |
1586 | let map = &tcx.hir(); |
1587 | let mut prev_enclosing_node = None; | |
1588 | let mut enclosing_node = node; | |
1589 | while Some(enclosing_node) != prev_enclosing_node { | |
a2a8927a | 1590 | if has_attr(map.attrs(enclosing_node), symbol) { |
f20569fa XL |
1591 | return true; |
1592 | } | |
1593 | prev_enclosing_node = Some(enclosing_node); | |
5099ac24 | 1594 | enclosing_node = map.local_def_id_to_hir_id(map.get_parent_item(enclosing_node)); |
f20569fa | 1595 | } |
a2a8927a | 1596 | |
f20569fa XL |
1597 | false |
1598 | } | |
1599 | ||
a2a8927a XL |
1600 | pub fn any_parent_is_automatically_derived(tcx: TyCtxt<'_>, node: HirId) -> bool { |
1601 | any_parent_has_attr(tcx, node, sym::automatically_derived) | |
1602 | } | |
1603 | ||
f20569fa XL |
1604 | /// Matches a function call with the given path and returns the arguments. |
1605 | /// | |
1606 | /// Usage: | |
1607 | /// | |
1608 | /// ```rust,ignore | |
1609 | /// if let Some(args) = match_function_call(cx, cmp_max_call, &paths::CMP_MAX); | |
1610 | /// ``` | |
1611 | pub fn match_function_call<'tcx>( | |
1612 | cx: &LateContext<'tcx>, | |
1613 | expr: &'tcx Expr<'_>, | |
1614 | path: &[&str], | |
1615 | ) -> Option<&'tcx [Expr<'tcx>]> { | |
1616 | if_chain! { | |
17df50a5 | 1617 | if let ExprKind::Call(fun, args) = expr.kind; |
f20569fa XL |
1618 | if let ExprKind::Path(ref qpath) = fun.kind; |
1619 | if let Some(fun_def_id) = cx.qpath_res(qpath, fun.hir_id).opt_def_id(); | |
1620 | if match_def_path(cx, fun_def_id, path); | |
1621 | then { | |
5099ac24 | 1622 | return Some(args); |
f20569fa XL |
1623 | } |
1624 | }; | |
1625 | None | |
1626 | } | |
1627 | ||
cdc7bbd5 XL |
1628 | /// Checks if the given `DefId` matches any of the paths. Returns the index of matching path, if |
1629 | /// any. | |
94222f64 | 1630 | /// |
5099ac24 | 1631 | /// Please use `tcx.get_diagnostic_name` if the targets are all diagnostic items. |
cdc7bbd5 XL |
1632 | pub fn match_any_def_paths(cx: &LateContext<'_>, did: DefId, paths: &[&[&str]]) -> Option<usize> { |
1633 | let search_path = cx.get_def_path(did); | |
1634 | paths | |
1635 | .iter() | |
1636 | .position(|p| p.iter().map(|x| Symbol::intern(x)).eq(search_path.iter().copied())) | |
f20569fa XL |
1637 | } |
1638 | ||
cdc7bbd5 | 1639 | /// Checks if the given `DefId` matches the path. |
f20569fa | 1640 | pub fn match_def_path<'tcx>(cx: &LateContext<'tcx>, did: DefId, syms: &[&str]) -> bool { |
cdc7bbd5 XL |
1641 | // We should probably move to Symbols in Clippy as well rather than interning every time. |
1642 | let path = cx.get_def_path(did); | |
1643 | syms.iter().map(|x| Symbol::intern(x)).eq(path.iter().copied()) | |
f20569fa XL |
1644 | } |
1645 | ||
a2a8927a XL |
1646 | /// Checks if the given `DefId` matches the `libc` item. |
1647 | pub fn match_libc_symbol(cx: &LateContext<'_>, did: DefId, name: &str) -> bool { | |
1648 | let path = cx.get_def_path(did); | |
1649 | // libc is meant to be used as a flat list of names, but they're all actually defined in different | |
1650 | // modules based on the target platform. Ignore everything but crate name and the item name. | |
1651 | path.first().map_or(false, |s| s.as_str() == "libc") && path.last().map_or(false, |s| s.as_str() == name) | |
1652 | } | |
1653 | ||
f20569fa XL |
1654 | /// Returns the list of condition expressions and the list of blocks in a |
1655 | /// sequence of `if/else`. | |
1656 | /// E.g., this returns `([a, b], [c, d, e])` for the expression | |
1657 | /// `if a { c } else if b { d } else { e }`. | |
cdc7bbd5 XL |
1658 | pub fn if_sequence<'tcx>(mut expr: &'tcx Expr<'tcx>) -> (Vec<&'tcx Expr<'tcx>>, Vec<&'tcx Block<'tcx>>) { |
1659 | let mut conds = Vec::new(); | |
1660 | let mut blocks: Vec<&Block<'_>> = Vec::new(); | |
f20569fa | 1661 | |
94222f64 | 1662 | while let Some(higher::IfOrIfLet { cond, then, r#else }) = higher::IfOrIfLet::hir(expr) { |
923072b8 | 1663 | conds.push(cond); |
c295e0f8 | 1664 | if let ExprKind::Block(block, _) = then.kind { |
f20569fa XL |
1665 | blocks.push(block); |
1666 | } else { | |
1667 | panic!("ExprKind::If node is not an ExprKind::Block"); | |
1668 | } | |
1669 | ||
c295e0f8 | 1670 | if let Some(else_expr) = r#else { |
f20569fa XL |
1671 | expr = else_expr; |
1672 | } else { | |
1673 | break; | |
1674 | } | |
1675 | } | |
1676 | ||
1677 | // final `else {..}` | |
1678 | if !blocks.is_empty() { | |
17df50a5 XL |
1679 | if let ExprKind::Block(block, _) = expr.kind { |
1680 | blocks.push(block); | |
f20569fa XL |
1681 | } |
1682 | } | |
1683 | ||
1684 | (conds, blocks) | |
1685 | } | |
1686 | ||
17df50a5 XL |
1687 | /// Checks if the given function kind is an async function. |
1688 | pub fn is_async_fn(kind: FnKind<'_>) -> bool { | |
04454e1e | 1689 | matches!(kind, FnKind::ItemFn(_, _, header) if header.asyncness == IsAsync::Async) |
17df50a5 XL |
1690 | } |
1691 | ||
1692 | /// Peels away all the compiler generated code surrounding the body of an async function, | |
5099ac24 | 1693 | pub fn get_async_fn_body<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'_>) -> Option<&'tcx Expr<'tcx>> { |
17df50a5 XL |
1694 | if let ExprKind::Call( |
1695 | _, | |
c295e0f8 XL |
1696 | &[ |
1697 | Expr { | |
923072b8 | 1698 | kind: ExprKind::Closure { body, .. }, |
c295e0f8 XL |
1699 | .. |
1700 | }, | |
1701 | ], | |
17df50a5 XL |
1702 | ) = body.value.kind |
1703 | { | |
1704 | if let ExprKind::Block( | |
1705 | Block { | |
1706 | stmts: [], | |
1707 | expr: | |
1708 | Some(Expr { | |
1709 | kind: ExprKind::DropTemps(expr), | |
1710 | .. | |
1711 | }), | |
1712 | .. | |
1713 | }, | |
1714 | _, | |
1715 | ) = tcx.hir().body(body).value.kind | |
1716 | { | |
1717 | return Some(expr); | |
1718 | } | |
1719 | }; | |
1720 | None | |
1721 | } | |
1722 | ||
f20569fa XL |
1723 | // check if expr is calling method or function with #[must_use] attribute |
1724 | pub fn is_must_use_func_call(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { | |
1725 | let did = match expr.kind { | |
17df50a5 | 1726 | ExprKind::Call(path, _) => if_chain! { |
f20569fa XL |
1727 | if let ExprKind::Path(ref qpath) = path.kind; |
1728 | if let def::Res::Def(_, did) = cx.qpath_res(qpath, path.hir_id); | |
1729 | then { | |
1730 | Some(did) | |
1731 | } else { | |
1732 | None | |
1733 | } | |
1734 | }, | |
5099ac24 | 1735 | ExprKind::MethodCall(..) => cx.typeck_results().type_dependent_def_id(expr.hir_id), |
f20569fa XL |
1736 | _ => None, |
1737 | }; | |
1738 | ||
04454e1e | 1739 | did.map_or(false, |did| cx.tcx.has_attr(did, sym::must_use)) |
f20569fa XL |
1740 | } |
1741 | ||
136023e0 XL |
1742 | /// Checks if an expression represents the identity function |
1743 | /// Only examines closures and `std::convert::identity` | |
1744 | pub fn is_expr_identity_function(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { | |
1745 | /// Checks if a function's body represents the identity function. Looks for bodies of the form: | |
1746 | /// * `|x| x` | |
1747 | /// * `|x| return x` | |
1748 | /// * `|x| { return x }` | |
1749 | /// * `|x| { return x; }` | |
1750 | fn is_body_identity_function(cx: &LateContext<'_>, func: &Body<'_>) -> bool { | |
1751 | let id = if_chain! { | |
1752 | if let [param] = func.params; | |
1753 | if let PatKind::Binding(_, id, _, _) = param.pat.kind; | |
1754 | then { | |
1755 | id | |
1756 | } else { | |
1757 | return false; | |
1758 | } | |
1759 | }; | |
1760 | ||
1761 | let mut expr = &func.value; | |
1762 | loop { | |
1763 | match expr.kind { | |
1764 | #[rustfmt::skip] | |
1765 | ExprKind::Block(&Block { stmts: [], expr: Some(e), .. }, _, ) | |
1766 | | ExprKind::Ret(Some(e)) => expr = e, | |
1767 | #[rustfmt::skip] | |
1768 | ExprKind::Block(&Block { stmts: [stmt], expr: None, .. }, _) => { | |
1769 | if_chain! { | |
1770 | if let StmtKind::Semi(e) | StmtKind::Expr(e) = stmt.kind; | |
1771 | if let ExprKind::Ret(Some(ret_val)) = e.kind; | |
1772 | then { | |
1773 | expr = ret_val; | |
1774 | } else { | |
1775 | return false; | |
1776 | } | |
1777 | } | |
1778 | }, | |
1779 | _ => return path_to_local_id(expr, id) && cx.typeck_results().expr_adjustments(expr).is_empty(), | |
1780 | } | |
1781 | } | |
1782 | } | |
1783 | ||
1784 | match expr.kind { | |
923072b8 | 1785 | ExprKind::Closure { body, .. } => is_body_identity_function(cx, cx.tcx.hir().body(body)), |
5099ac24 | 1786 | _ => path_def_id(cx, expr).map_or(false, |id| match_def_path(cx, id, &paths::CONVERT_IDENTITY)), |
136023e0 XL |
1787 | } |
1788 | } | |
1789 | ||
cdc7bbd5 | 1790 | /// Gets the node where an expression is either used, or it's type is unified with another branch. |
5099ac24 FG |
1791 | /// Returns both the node and the `HirId` of the closest child node. |
1792 | pub fn get_expr_use_or_unification_node<'tcx>(tcx: TyCtxt<'tcx>, expr: &Expr<'_>) -> Option<(Node<'tcx>, HirId)> { | |
cdc7bbd5 | 1793 | let mut child_id = expr.hir_id; |
c295e0f8 | 1794 | let mut iter = tcx.hir().parent_iter(child_id); |
cdc7bbd5 XL |
1795 | loop { |
1796 | match iter.next() { | |
1797 | None => break None, | |
1798 | Some((id, Node::Block(_))) => child_id = id, | |
1799 | Some((id, Node::Arm(arm))) if arm.body.hir_id == child_id => child_id = id, | |
1800 | Some((_, Node::Expr(expr))) => match expr.kind { | |
1801 | ExprKind::Match(_, [arm], _) if arm.hir_id == child_id => child_id = expr.hir_id, | |
1802 | ExprKind::Block(..) | ExprKind::DropTemps(_) => child_id = expr.hir_id, | |
1803 | ExprKind::If(_, then_expr, None) if then_expr.hir_id == child_id => break None, | |
5099ac24 | 1804 | _ => break Some((Node::Expr(expr), child_id)), |
cdc7bbd5 | 1805 | }, |
5099ac24 | 1806 | Some((_, node)) => break Some((node, child_id)), |
cdc7bbd5 XL |
1807 | } |
1808 | } | |
1809 | } | |
1810 | ||
1811 | /// Checks if the result of an expression is used, or it's type is unified with another branch. | |
1812 | pub fn is_expr_used_or_unified(tcx: TyCtxt<'_>, expr: &Expr<'_>) -> bool { | |
1813 | !matches!( | |
1814 | get_expr_use_or_unification_node(tcx, expr), | |
5099ac24 FG |
1815 | None | Some(( |
1816 | Node::Stmt(Stmt { | |
1817 | kind: StmtKind::Expr(_) | |
1818 | | StmtKind::Semi(_) | |
1819 | | StmtKind::Local(Local { | |
1820 | pat: Pat { | |
1821 | kind: PatKind::Wild, | |
1822 | .. | |
1823 | }, | |
cdc7bbd5 | 1824 | .. |
5099ac24 FG |
1825 | }), |
1826 | .. | |
1827 | }), | |
1828 | _ | |
1829 | )) | |
cdc7bbd5 XL |
1830 | ) |
1831 | } | |
1832 | ||
1833 | /// Checks if the expression is the final expression returned from a block. | |
1834 | pub fn is_expr_final_block_expr(tcx: TyCtxt<'_>, expr: &Expr<'_>) -> bool { | |
1835 | matches!(get_parent_node(tcx, expr.hir_id), Some(Node::Block(..))) | |
1836 | } | |
1837 | ||
a2a8927a XL |
1838 | pub fn std_or_core(cx: &LateContext<'_>) -> Option<&'static str> { |
1839 | if !is_no_std_crate(cx) { | |
1840 | Some("std") | |
1841 | } else if !is_no_core_crate(cx) { | |
1842 | Some("core") | |
1843 | } else { | |
1844 | None | |
1845 | } | |
1846 | } | |
1847 | ||
f20569fa XL |
1848 | pub fn is_no_std_crate(cx: &LateContext<'_>) -> bool { |
1849 | cx.tcx.hir().attrs(hir::CRATE_HIR_ID).iter().any(|attr| { | |
1850 | if let ast::AttrKind::Normal(ref attr, _) = attr.kind { | |
1851 | attr.path == sym::no_std | |
1852 | } else { | |
1853 | false | |
1854 | } | |
1855 | }) | |
1856 | } | |
1857 | ||
a2a8927a XL |
1858 | pub fn is_no_core_crate(cx: &LateContext<'_>) -> bool { |
1859 | cx.tcx.hir().attrs(hir::CRATE_HIR_ID).iter().any(|attr| { | |
1860 | if let ast::AttrKind::Normal(ref attr, _) = attr.kind { | |
1861 | attr.path == sym::no_core | |
1862 | } else { | |
1863 | false | |
1864 | } | |
1865 | }) | |
1866 | } | |
1867 | ||
f20569fa XL |
1868 | /// Check if parent of a hir node is a trait implementation block. |
1869 | /// For example, `f` in | |
a2a8927a XL |
1870 | /// ```rust |
1871 | /// # struct S; | |
1872 | /// # trait Trait { fn f(); } | |
f20569fa XL |
1873 | /// impl Trait for S { |
1874 | /// fn f() {} | |
1875 | /// } | |
1876 | /// ``` | |
1877 | pub fn is_trait_impl_item(cx: &LateContext<'_>, hir_id: HirId) -> bool { | |
1878 | if let Some(Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_node(hir_id)) { | |
1879 | matches!(item.kind, ItemKind::Impl(hir::Impl { of_trait: Some(_), .. })) | |
1880 | } else { | |
1881 | false | |
1882 | } | |
1883 | } | |
1884 | ||
1885 | /// Check if it's even possible to satisfy the `where` clause for the item. | |
1886 | /// | |
1887 | /// `trivial_bounds` feature allows functions with unsatisfiable bounds, for example: | |
1888 | /// | |
1889 | /// ```ignore | |
1890 | /// fn foo() where i32: Iterator { | |
1891 | /// for _ in 2i32 {} | |
1892 | /// } | |
1893 | /// ``` | |
1894 | pub fn fn_has_unsatisfiable_preds(cx: &LateContext<'_>, did: DefId) -> bool { | |
1895 | use rustc_trait_selection::traits; | |
1896 | let predicates = cx | |
1897 | .tcx | |
1898 | .predicates_of(did) | |
1899 | .predicates | |
1900 | .iter() | |
5099ac24 | 1901 | .filter_map(|(p, _)| if p.is_global() { Some(*p) } else { None }); |
f20569fa XL |
1902 | traits::impossible_predicates( |
1903 | cx.tcx, | |
1904 | traits::elaborate_predicates(cx.tcx, predicates) | |
1905 | .map(|o| o.predicate) | |
1906 | .collect::<Vec<_>>(), | |
1907 | ) | |
1908 | } | |
1909 | ||
1910 | /// Returns the `DefId` of the callee if the given expression is a function or method call. | |
1911 | pub fn fn_def_id(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<DefId> { | |
1912 | match &expr.kind { | |
1913 | ExprKind::MethodCall(..) => cx.typeck_results().type_dependent_def_id(expr.hir_id), | |
1914 | ExprKind::Call( | |
1915 | Expr { | |
1916 | kind: ExprKind::Path(qpath), | |
1917 | hir_id: path_hir_id, | |
1918 | .. | |
1919 | }, | |
1920 | .., | |
923072b8 FG |
1921 | ) => { |
1922 | // Only return Fn-like DefIds, not the DefIds of statics/consts/etc that contain or | |
1923 | // deref to fn pointers, dyn Fn, impl Fn - #8850 | |
1924 | if let Res::Def(DefKind::Fn | DefKind::Ctor(..) | DefKind::AssocFn, id) = | |
1925 | cx.typeck_results().qpath_res(qpath, *path_hir_id) | |
1926 | { | |
1927 | Some(id) | |
1928 | } else { | |
1929 | None | |
1930 | } | |
1931 | }, | |
f20569fa XL |
1932 | _ => None, |
1933 | } | |
1934 | } | |
1935 | ||
f20569fa XL |
1936 | /// Returns Option<String> where String is a textual representation of the type encapsulated in the |
1937 | /// slice iff the given expression is a slice of primitives (as defined in the | |
1938 | /// `is_recursively_primitive_type` function) and None otherwise. | |
1939 | pub fn is_slice_of_primitives(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<String> { | |
1940 | let expr_type = cx.typeck_results().expr_ty_adjusted(expr); | |
1941 | let expr_kind = expr_type.kind(); | |
1942 | let is_primitive = match expr_kind { | |
5099ac24 | 1943 | rustc_ty::Slice(element_type) => is_recursively_primitive_type(*element_type), |
cdc7bbd5 XL |
1944 | rustc_ty::Ref(_, inner_ty, _) if matches!(inner_ty.kind(), &rustc_ty::Slice(_)) => { |
1945 | if let rustc_ty::Slice(element_type) = inner_ty.kind() { | |
5099ac24 | 1946 | is_recursively_primitive_type(*element_type) |
f20569fa XL |
1947 | } else { |
1948 | unreachable!() | |
1949 | } | |
1950 | }, | |
1951 | _ => false, | |
1952 | }; | |
1953 | ||
1954 | if is_primitive { | |
1955 | // if we have wrappers like Array, Slice or Tuple, print these | |
1956 | // and get the type enclosed in the slice ref | |
5099ac24 | 1957 | match expr_type.peel_refs().walk().nth(1).unwrap().expect_ty().kind() { |
cdc7bbd5 XL |
1958 | rustc_ty::Slice(..) => return Some("slice".into()), |
1959 | rustc_ty::Array(..) => return Some("array".into()), | |
1960 | rustc_ty::Tuple(..) => return Some("tuple".into()), | |
f20569fa XL |
1961 | _ => { |
1962 | // is_recursively_primitive_type() should have taken care | |
1963 | // of the rest and we can rely on the type that is found | |
1964 | let refs_peeled = expr_type.peel_refs(); | |
5099ac24 | 1965 | return Some(refs_peeled.walk().last().unwrap().to_string()); |
f20569fa XL |
1966 | }, |
1967 | } | |
1968 | } | |
1969 | None | |
1970 | } | |
1971 | ||
1972 | /// returns list of all pairs (a, b) from `exprs` such that `eq(a, b)` | |
1973 | /// `hash` must be comformed with `eq` | |
1974 | pub fn search_same<T, Hash, Eq>(exprs: &[T], hash: Hash, eq: Eq) -> Vec<(&T, &T)> | |
1975 | where | |
1976 | Hash: Fn(&T) -> u64, | |
1977 | Eq: Fn(&T, &T) -> bool, | |
1978 | { | |
17df50a5 XL |
1979 | match exprs { |
1980 | [a, b] if eq(a, b) => return vec![(a, b)], | |
1981 | _ if exprs.len() <= 2 => return vec![], | |
1982 | _ => {}, | |
f20569fa XL |
1983 | } |
1984 | ||
1985 | let mut match_expr_list: Vec<(&T, &T)> = Vec::new(); | |
1986 | ||
17df50a5 XL |
1987 | let mut map: UnhashMap<u64, Vec<&_>> = |
1988 | UnhashMap::with_capacity_and_hasher(exprs.len(), BuildHasherDefault::default()); | |
f20569fa XL |
1989 | |
1990 | for expr in exprs { | |
1991 | match map.entry(hash(expr)) { | |
1992 | Entry::Occupied(mut o) => { | |
1993 | for o in o.get() { | |
1994 | if eq(o, expr) { | |
1995 | match_expr_list.push((o, expr)); | |
1996 | } | |
1997 | } | |
1998 | o.get_mut().push(expr); | |
1999 | }, | |
2000 | Entry::Vacant(v) => { | |
2001 | v.insert(vec![expr]); | |
2002 | }, | |
2003 | } | |
2004 | } | |
2005 | ||
2006 | match_expr_list | |
2007 | } | |
2008 | ||
2009 | /// Peels off all references on the pattern. Returns the underlying pattern and the number of | |
2010 | /// references removed. | |
5099ac24 FG |
2011 | pub fn peel_hir_pat_refs<'a>(pat: &'a Pat<'a>) -> (&'a Pat<'a>, usize) { |
2012 | fn peel<'a>(pat: &'a Pat<'a>, count: usize) -> (&'a Pat<'a>, usize) { | |
f20569fa XL |
2013 | if let PatKind::Ref(pat, _) = pat.kind { |
2014 | peel(pat, count + 1) | |
2015 | } else { | |
2016 | (pat, count) | |
2017 | } | |
2018 | } | |
2019 | peel(pat, 0) | |
2020 | } | |
2021 | ||
cdc7bbd5 XL |
2022 | /// Peels of expressions while the given closure returns `Some`. |
2023 | pub fn peel_hir_expr_while<'tcx>( | |
2024 | mut expr: &'tcx Expr<'tcx>, | |
2025 | mut f: impl FnMut(&'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>>, | |
2026 | ) -> &'tcx Expr<'tcx> { | |
2027 | while let Some(e) = f(expr) { | |
2028 | expr = e; | |
2029 | } | |
2030 | expr | |
2031 | } | |
2032 | ||
f20569fa XL |
2033 | /// Peels off up to the given number of references on the expression. Returns the underlying |
2034 | /// expression and the number of references removed. | |
5099ac24 | 2035 | pub fn peel_n_hir_expr_refs<'a>(expr: &'a Expr<'a>, count: usize) -> (&'a Expr<'a>, usize) { |
cdc7bbd5 XL |
2036 | let mut remaining = count; |
2037 | let e = peel_hir_expr_while(expr, |e| match e.kind { | |
c295e0f8 | 2038 | ExprKind::AddrOf(ast::BorrowKind::Ref, _, e) if remaining != 0 => { |
cdc7bbd5 XL |
2039 | remaining -= 1; |
2040 | Some(e) | |
2041 | }, | |
2042 | _ => None, | |
2043 | }); | |
2044 | (e, count - remaining) | |
f20569fa XL |
2045 | } |
2046 | ||
2047 | /// Peels off all references on the expression. Returns the underlying expression and the number of | |
2048 | /// references removed. | |
5099ac24 | 2049 | pub fn peel_hir_expr_refs<'a>(expr: &'a Expr<'a>) -> (&'a Expr<'a>, usize) { |
cdc7bbd5 XL |
2050 | let mut count = 0; |
2051 | let e = peel_hir_expr_while(expr, |e| match e.kind { | |
c295e0f8 | 2052 | ExprKind::AddrOf(ast::BorrowKind::Ref, _, e) => { |
cdc7bbd5 XL |
2053 | count += 1; |
2054 | Some(e) | |
2055 | }, | |
2056 | _ => None, | |
2057 | }); | |
2058 | (e, count) | |
f20569fa XL |
2059 | } |
2060 | ||
136023e0 XL |
2061 | /// Removes `AddrOf` operators (`&`) or deref operators (`*`), but only if a reference type is |
2062 | /// dereferenced. An overloaded deref such as `Vec` to slice would not be removed. | |
2063 | pub fn peel_ref_operators<'hir>(cx: &LateContext<'_>, mut expr: &'hir Expr<'hir>) -> &'hir Expr<'hir> { | |
2064 | loop { | |
2065 | match expr.kind { | |
2066 | ExprKind::AddrOf(_, _, e) => expr = e, | |
2067 | ExprKind::Unary(UnOp::Deref, e) if cx.typeck_results().expr_ty(e).is_ref() => expr = e, | |
2068 | _ => break, | |
2069 | } | |
2070 | } | |
2071 | expr | |
2072 | } | |
2073 | ||
f20569fa | 2074 | pub fn is_hir_ty_cfg_dependant(cx: &LateContext<'_>, ty: &hir::Ty<'_>) -> bool { |
3c0e092e XL |
2075 | if let TyKind::Path(QPath::Resolved(_, path)) = ty.kind { |
2076 | if let Res::Def(_, def_id) = path.res { | |
2077 | return cx.tcx.has_attr(def_id, sym::cfg) || cx.tcx.has_attr(def_id, sym::cfg_attr); | |
f20569fa XL |
2078 | } |
2079 | } | |
3c0e092e | 2080 | false |
f20569fa | 2081 | } |
136023e0 | 2082 | |
923072b8 | 2083 | static TEST_ITEM_NAMES_CACHE: OnceLock<Mutex<FxHashMap<LocalDefId, Vec<Symbol>>>> = OnceLock::new(); |
a2a8927a | 2084 | |
5099ac24 | 2085 | fn with_test_item_names<'tcx>(tcx: TyCtxt<'tcx>, module: LocalDefId, f: impl Fn(&[Symbol]) -> bool) -> bool { |
a2a8927a XL |
2086 | let cache = TEST_ITEM_NAMES_CACHE.get_or_init(|| Mutex::new(FxHashMap::default())); |
2087 | let mut map: MutexGuard<'_, FxHashMap<LocalDefId, Vec<Symbol>>> = cache.lock().unwrap(); | |
923072b8 FG |
2088 | let value = map.entry(module); |
2089 | match value { | |
a2a8927a XL |
2090 | Entry::Occupied(entry) => f(entry.get()), |
2091 | Entry::Vacant(entry) => { | |
923072b8 FG |
2092 | let mut names = Vec::new(); |
2093 | for id in tcx.hir().module_items(module) { | |
2094 | if matches!(tcx.def_kind(id.def_id), DefKind::Const) | |
2095 | && let item = tcx.hir().item(id) | |
2096 | && let ItemKind::Const(ty, _body) = item.kind { | |
2097 | if let TyKind::Path(QPath::Resolved(_, path)) = ty.kind { | |
2098 | // We could also check for the type name `test::TestDescAndFn` | |
2099 | if let Res::Def(DefKind::Struct, _) = path.res { | |
2100 | let has_test_marker = tcx | |
2101 | .hir() | |
2102 | .attrs(item.hir_id()) | |
2103 | .iter() | |
2104 | .any(|a| a.has_name(sym::rustc_test_marker)); | |
2105 | if has_test_marker { | |
2106 | names.push(item.ident.name); | |
2107 | } | |
2108 | } | |
2109 | } | |
2110 | } | |
2111 | } | |
2112 | names.sort_unstable(); | |
2113 | f(&*entry.insert(names)) | |
a2a8927a XL |
2114 | }, |
2115 | } | |
2116 | } | |
2117 | ||
3c0e092e XL |
2118 | /// Checks if the function containing the given `HirId` is a `#[test]` function |
2119 | /// | |
5099ac24 | 2120 | /// Note: Add `// compile-flags: --test` to UI tests with a `#[test]` function |
3c0e092e | 2121 | pub fn is_in_test_function(tcx: TyCtxt<'_>, id: hir::HirId) -> bool { |
a2a8927a XL |
2122 | with_test_item_names(tcx, tcx.parent_module(id), |names| { |
2123 | tcx.hir() | |
2124 | .parent_iter(id) | |
2125 | // Since you can nest functions we need to collect all until we leave | |
2126 | // function scope | |
2127 | .any(|(_id, node)| { | |
2128 | if let Node::Item(item) = node { | |
2129 | if let ItemKind::Fn(_, _, _) = item.kind { | |
2130 | // Note that we have sorted the item names in the visitor, | |
2131 | // so the binary_search gets the same as `contains`, but faster. | |
2132 | return names.binary_search(&item.ident.name).is_ok(); | |
2133 | } | |
3c0e092e | 2134 | } |
a2a8927a XL |
2135 | false |
2136 | }) | |
2137 | }) | |
3c0e092e XL |
2138 | } |
2139 | ||
923072b8 FG |
2140 | /// Checks if the item containing the given `HirId` has `#[cfg(test)]` attribute applied |
2141 | /// | |
2142 | /// Note: Add `// compile-flags: --test` to UI tests with a `#[cfg(test)]` function | |
2143 | pub fn is_in_cfg_test(tcx: TyCtxt<'_>, id: hir::HirId) -> bool { | |
2144 | fn is_cfg_test(attr: &Attribute) -> bool { | |
2145 | if attr.has_name(sym::cfg) | |
2146 | && let Some(items) = attr.meta_item_list() | |
2147 | && let [item] = &*items | |
2148 | && item.has_name(sym::test) | |
2149 | { | |
2150 | true | |
2151 | } else { | |
2152 | false | |
2153 | } | |
2154 | } | |
2155 | tcx.hir() | |
2156 | .parent_iter(id) | |
2157 | .flat_map(|(parent_id, _)| tcx.hir().attrs(parent_id)) | |
2158 | .any(is_cfg_test) | |
2159 | } | |
2160 | ||
3c0e092e XL |
2161 | /// Checks whether item either has `test` attribute applied, or |
2162 | /// is a module with `test` in its name. | |
2163 | /// | |
5099ac24 | 2164 | /// Note: Add `// compile-flags: --test` to UI tests with a `#[test]` function |
3c0e092e XL |
2165 | pub fn is_test_module_or_function(tcx: TyCtxt<'_>, item: &Item<'_>) -> bool { |
2166 | is_in_test_function(tcx, item.hir_id()) | |
2167 | || matches!(item.kind, ItemKind::Mod(..)) | |
2168 | && item.ident.name.as_str().split('_').any(|a| a == "test" || a == "tests") | |
136023e0 XL |
2169 | } |
2170 | ||
2171 | macro_rules! op_utils { | |
2172 | ($($name:ident $assign:ident)*) => { | |
2173 | /// Binary operation traits like `LangItem::Add` | |
2174 | pub static BINOP_TRAITS: &[LangItem] = &[$(LangItem::$name,)*]; | |
2175 | ||
2176 | /// Operator-Assign traits like `LangItem::AddAssign` | |
2177 | pub static OP_ASSIGN_TRAITS: &[LangItem] = &[$(LangItem::$assign,)*]; | |
2178 | ||
2179 | /// Converts `BinOpKind::Add` to `(LangItem::Add, LangItem::AddAssign)`, for example | |
2180 | pub fn binop_traits(kind: hir::BinOpKind) -> Option<(LangItem, LangItem)> { | |
2181 | match kind { | |
2182 | $(hir::BinOpKind::$name => Some((LangItem::$name, LangItem::$assign)),)* | |
2183 | _ => None, | |
2184 | } | |
2185 | } | |
2186 | }; | |
2187 | } | |
2188 | ||
2189 | op_utils! { | |
2190 | Add AddAssign | |
2191 | Sub SubAssign | |
2192 | Mul MulAssign | |
2193 | Div DivAssign | |
2194 | Rem RemAssign | |
2195 | BitXor BitXorAssign | |
2196 | BitAnd BitAndAssign | |
2197 | BitOr BitOrAssign | |
2198 | Shl ShlAssign | |
2199 | Shr ShrAssign | |
2200 | } |