]>
Commit | Line | Data |
---|---|---|
f20569fa | 1 | #![feature(box_patterns)] |
a2a8927a | 2 | #![feature(control_flow_enum)] |
f20569fa | 3 | #![feature(in_band_lifetimes)] |
a2a8927a XL |
4 | #![feature(let_else)] |
5 | #![feature(once_cell)] | |
f20569fa XL |
6 | #![feature(rustc_private)] |
7 | #![recursion_limit = "512"] | |
17df50a5 | 8 | #![cfg_attr(feature = "deny-warnings", deny(warnings))] |
f20569fa | 9 | #![allow(clippy::missing_errors_doc, clippy::missing_panics_doc, clippy::must_use_candidate)] |
17df50a5 XL |
10 | // warn on the same lints as `clippy_lints` |
11 | #![warn(trivial_casts, trivial_numeric_casts)] | |
12 | // warn on lints, that are included in `rust-lang/rust`s bootstrap | |
13 | #![warn(rust_2018_idioms, unused_lifetimes)] | |
14 | // warn on rustc internal lints | |
15 | #![warn(rustc::internal)] | |
f20569fa XL |
16 | |
17 | // FIXME: switch to something more ergonomic here, once available. | |
18 | // (Currently there is no way to opt into sysroot crates without `extern crate`.) | |
19 | extern crate rustc_ast; | |
20 | extern crate rustc_ast_pretty; | |
cdc7bbd5 | 21 | extern crate rustc_attr; |
f20569fa XL |
22 | extern crate rustc_data_structures; |
23 | extern crate rustc_errors; | |
24 | extern crate rustc_hir; | |
25 | extern crate rustc_infer; | |
26 | extern crate rustc_lexer; | |
27 | extern crate rustc_lint; | |
28 | extern crate rustc_middle; | |
f20569fa XL |
29 | extern crate rustc_session; |
30 | extern crate rustc_span; | |
31 | extern crate rustc_target; | |
32 | extern crate rustc_trait_selection; | |
33 | extern crate rustc_typeck; | |
34 | ||
35 | #[macro_use] | |
36 | pub mod sym_helper; | |
37 | ||
38 | #[allow(clippy::module_name_repetitions)] | |
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; | |
cdc7bbd5 | 47 | pub mod msrvs; |
f20569fa XL |
48 | pub mod numeric_literal; |
49 | pub mod paths; | |
50 | pub mod ptr; | |
51 | pub mod qualify_min_const_fn; | |
cdc7bbd5 | 52 | pub mod source; |
3c0e092e | 53 | pub mod str_utils; |
f20569fa | 54 | pub mod sugg; |
cdc7bbd5 | 55 | pub mod ty; |
f20569fa XL |
56 | pub mod usage; |
57 | pub mod visitors; | |
58 | ||
59 | pub use self::attrs::*; | |
cdc7bbd5 | 60 | pub use self::hir_utils::{both, count_eq, eq_expr_value, over, SpanlessEq, SpanlessHash}; |
f20569fa | 61 | |
f20569fa XL |
62 | use std::collections::hash_map::Entry; |
63 | use std::hash::BuildHasherDefault; | |
a2a8927a XL |
64 | use std::lazy::SyncOnceCell; |
65 | use std::sync::{Mutex, MutexGuard}; | |
f20569fa XL |
66 | |
67 | use if_chain::if_chain; | |
c295e0f8 | 68 | use rustc_ast::ast::{self, Attribute, LitKind}; |
a2a8927a | 69 | use rustc_data_structures::fx::FxHashMap; |
17df50a5 | 70 | use rustc_data_structures::unhash::UnhashMap; |
f20569fa | 71 | use rustc_hir as hir; |
cdc7bbd5 | 72 | use rustc_hir::def::{DefKind, Res}; |
17df50a5 | 73 | use rustc_hir::def_id::DefId; |
c295e0f8 | 74 | use rustc_hir::hir_id::{HirIdMap, HirIdSet}; |
a2a8927a | 75 | use rustc_hir::intravisit::{walk_expr, ErasedMap, FnKind, NestedVisitorMap, Visitor}; |
3c0e092e | 76 | use rustc_hir::itemlikevisit::ItemLikeVisitor; |
c295e0f8 | 77 | use rustc_hir::LangItem::{OptionNone, ResultErr, ResultOk}; |
f20569fa | 78 | use rustc_hir::{ |
a2a8927a XL |
79 | def, Arm, BindingAnnotation, Block, BlockCheckMode, Body, Constness, Destination, Expr, ExprKind, FnDecl, |
80 | ForeignItem, GenericArgs, HirId, Impl, ImplItem, ImplItemKind, IsAsync, Item, ItemKind, LangItem, Local, | |
81 | MatchSource, Mutability, Node, Param, Pat, PatKind, Path, PathSegment, PrimTy, QPath, Stmt, StmtKind, TraitItem, | |
82 | TraitItemKind, TraitRef, TyKind, UnOp, ArrayLen | |
f20569fa | 83 | }; |
f20569fa XL |
84 | use rustc_lint::{LateContext, Level, Lint, LintContext}; |
85 | use rustc_middle::hir::exports::Export; | |
86 | use rustc_middle::hir::map::Map; | |
c295e0f8 | 87 | use rustc_middle::hir::place::PlaceBase; |
cdc7bbd5 | 88 | use rustc_middle::ty as rustc_ty; |
c295e0f8 XL |
89 | use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow}; |
90 | use rustc_middle::ty::binding::BindingMode; | |
91 | use rustc_middle::ty::{layout::IntegerExt, BorrowKind, DefIdTree, Ty, TyCtxt, TypeAndMut, TypeFoldable, UpvarCapture}; | |
f20569fa XL |
92 | use rustc_semver::RustcVersion; |
93 | use rustc_session::Session; | |
a2a8927a | 94 | use rustc_span::def_id::LocalDefId; |
cdc7bbd5 | 95 | use rustc_span::hygiene::{ExpnKind, MacroKind}; |
f20569fa XL |
96 | use rustc_span::source_map::original_sp; |
97 | use rustc_span::sym; | |
98 | use rustc_span::symbol::{kw, Symbol}; | |
cdc7bbd5 | 99 | use rustc_span::{Span, DUMMY_SP}; |
f20569fa | 100 | use rustc_target::abi::Integer; |
f20569fa XL |
101 | |
102 | use crate::consts::{constant, Constant}; | |
c295e0f8 | 103 | use crate::ty::{can_partially_move_ty, is_copy, is_recursively_primitive_type}; |
a2a8927a | 104 | use crate::visitors::expr_visitor_no_bodies; |
f20569fa XL |
105 | |
106 | pub fn parse_msrv(msrv: &str, sess: Option<&Session>, span: Option<Span>) -> Option<RustcVersion> { | |
107 | if let Ok(version) = RustcVersion::parse(msrv) { | |
108 | return Some(version); | |
109 | } else if let Some(sess) = sess { | |
110 | if let Some(span) = span { | |
111 | sess.span_err(span, &format!("`{}` is not a valid Rust version", msrv)); | |
112 | } | |
113 | } | |
114 | None | |
115 | } | |
116 | ||
117 | pub fn meets_msrv(msrv: Option<&RustcVersion>, lint_msrv: &RustcVersion) -> bool { | |
118 | msrv.map_or(true, |msrv| msrv.meets(*lint_msrv)) | |
119 | } | |
120 | ||
121 | #[macro_export] | |
122 | macro_rules! extract_msrv_attr { | |
123 | (LateContext) => { | |
124 | extract_msrv_attr!(@LateContext, ()); | |
125 | }; | |
126 | (EarlyContext) => { | |
127 | extract_msrv_attr!(@EarlyContext); | |
128 | }; | |
129 | (@$context:ident$(, $call:tt)?) => { | |
130 | fn enter_lint_attrs(&mut self, cx: &rustc_lint::$context<'tcx>, attrs: &'tcx [rustc_ast::ast::Attribute]) { | |
131 | use $crate::get_unique_inner_attr; | |
132 | match get_unique_inner_attr(cx.sess$($call)?, attrs, "msrv") { | |
133 | Some(msrv_attr) => { | |
134 | if let Some(msrv) = msrv_attr.value_str() { | |
135 | self.msrv = $crate::parse_msrv( | |
136 | &msrv.to_string(), | |
137 | Some(cx.sess$($call)?), | |
138 | Some(msrv_attr.span), | |
139 | ); | |
140 | } else { | |
141 | cx.sess$($call)?.span_err(msrv_attr.span, "bad clippy attribute"); | |
142 | } | |
143 | }, | |
144 | _ => (), | |
145 | } | |
146 | } | |
147 | }; | |
148 | } | |
149 | ||
a2a8927a XL |
150 | /// Returns `true` if the span comes from a macro expansion, no matter if from a |
151 | /// macro by example or from a procedural macro | |
152 | #[must_use] | |
153 | pub fn in_macro(span: Span) -> bool { | |
154 | span.from_expansion() && !matches!(span.ctxt().outer_expn_data().kind, ExpnKind::Desugaring(..)) | |
155 | } | |
156 | ||
f20569fa XL |
157 | /// Returns `true` if the two spans come from differing expansions (i.e., one is |
158 | /// from a macro and one isn't). | |
159 | #[must_use] | |
160 | pub fn differing_macro_contexts(lhs: Span, rhs: Span) -> bool { | |
161 | rhs.ctxt() != lhs.ctxt() | |
162 | } | |
163 | ||
cdc7bbd5 XL |
164 | /// If the given expression is a local binding, find the initializer expression. |
165 | /// If that initializer expression is another local binding, find its initializer again. | |
166 | /// This process repeats as long as possible (but usually no more than once). Initializer | |
167 | /// expressions with adjustments are ignored. If this is not desired, use [`find_binding_init`] | |
168 | /// instead. | |
169 | /// | |
170 | /// Examples: | |
a2a8927a | 171 | /// ``` |
cdc7bbd5 XL |
172 | /// let abc = 1; |
173 | /// // ^ output | |
174 | /// let def = abc; | |
a2a8927a | 175 | /// dbg!(def); |
cdc7bbd5 XL |
176 | /// // ^^^ input |
177 | /// | |
178 | /// // or... | |
179 | /// let abc = 1; | |
180 | /// let def = abc + 2; | |
181 | /// // ^^^^^^^ output | |
a2a8927a | 182 | /// dbg!(def); |
cdc7bbd5 XL |
183 | /// // ^^^ input |
184 | /// ``` | |
185 | pub fn expr_or_init<'a, 'b, 'tcx: 'b>(cx: &LateContext<'tcx>, mut expr: &'a Expr<'b>) -> &'a Expr<'b> { | |
186 | while let Some(init) = path_to_local(expr) | |
187 | .and_then(|id| find_binding_init(cx, id)) | |
188 | .filter(|init| cx.typeck_results().expr_adjustments(init).is_empty()) | |
189 | { | |
190 | expr = init; | |
191 | } | |
192 | expr | |
193 | } | |
194 | ||
195 | /// Finds the initializer expression for a local binding. Returns `None` if the binding is mutable. | |
196 | /// By only considering immutable bindings, we guarantee that the returned expression represents the | |
197 | /// value of the binding wherever it is referenced. | |
198 | /// | |
199 | /// Example: For `let x = 1`, if the `HirId` of `x` is provided, the `Expr` `1` is returned. | |
200 | /// Note: If you have an expression that references a binding `x`, use `path_to_local` to get the | |
201 | /// canonical binding `HirId`. | |
202 | pub fn find_binding_init<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<&'tcx Expr<'tcx>> { | |
203 | let hir = cx.tcx.hir(); | |
204 | if_chain! { | |
205 | if let Some(Node::Binding(pat)) = hir.find(hir_id); | |
206 | if matches!(pat.kind, PatKind::Binding(BindingAnnotation::Unannotated, ..)); | |
207 | let parent = hir.get_parent_node(hir_id); | |
208 | if let Some(Node::Local(local)) = hir.find(parent); | |
209 | then { | |
210 | return local.init; | |
211 | } | |
212 | } | |
213 | None | |
214 | } | |
215 | ||
f20569fa XL |
216 | /// Returns `true` if the given `NodeId` is inside a constant context |
217 | /// | |
218 | /// # Example | |
219 | /// | |
220 | /// ```rust,ignore | |
221 | /// if in_constant(cx, expr.hir_id) { | |
222 | /// // Do something | |
223 | /// } | |
224 | /// ``` | |
225 | pub fn in_constant(cx: &LateContext<'_>, id: HirId) -> bool { | |
226 | let parent_id = cx.tcx.hir().get_parent_item(id); | |
227 | match cx.tcx.hir().get(parent_id) { | |
228 | Node::Item(&Item { | |
229 | kind: ItemKind::Const(..) | ItemKind::Static(..), | |
230 | .. | |
231 | }) | |
232 | | Node::TraitItem(&TraitItem { | |
233 | kind: TraitItemKind::Const(..), | |
234 | .. | |
235 | }) | |
236 | | Node::ImplItem(&ImplItem { | |
237 | kind: ImplItemKind::Const(..), | |
238 | .. | |
239 | }) | |
240 | | Node::AnonConst(_) => true, | |
241 | Node::Item(&Item { | |
242 | kind: ItemKind::Fn(ref sig, ..), | |
243 | .. | |
244 | }) | |
245 | | Node::ImplItem(&ImplItem { | |
246 | kind: ImplItemKind::Fn(ref sig, _), | |
247 | .. | |
248 | }) => sig.header.constness == Constness::Const, | |
249 | _ => false, | |
250 | } | |
251 | } | |
252 | ||
cdc7bbd5 XL |
253 | /// Checks if a `QPath` resolves to a constructor of a `LangItem`. |
254 | /// For example, use this to check whether a function call or a pattern is `Some(..)`. | |
255 | pub fn is_lang_ctor(cx: &LateContext<'_>, qpath: &QPath<'_>, lang_item: LangItem) -> bool { | |
256 | if let QPath::Resolved(_, path) = qpath { | |
257 | if let Res::Def(DefKind::Ctor(..), ctor_id) = path.res { | |
258 | if let Ok(item_id) = cx.tcx.lang_items().require(lang_item) { | |
259 | return cx.tcx.parent(ctor_id) == Some(item_id); | |
260 | } | |
261 | } | |
262 | } | |
263 | false | |
264 | } | |
265 | ||
94222f64 | 266 | pub fn is_unit_expr(expr: &Expr<'_>) -> bool { |
c295e0f8 XL |
267 | matches!( |
268 | expr.kind, | |
269 | ExprKind::Block( | |
270 | Block { | |
271 | stmts: [], | |
272 | expr: None, | |
273 | .. | |
274 | }, | |
275 | _ | |
276 | ) | ExprKind::Tup([]) | |
277 | ) | |
94222f64 XL |
278 | } |
279 | ||
f20569fa | 280 | /// Checks if given pattern is a wildcard (`_`) |
136023e0 | 281 | pub fn is_wild(pat: &Pat<'_>) -> bool { |
f20569fa XL |
282 | matches!(pat.kind, PatKind::Wild) |
283 | } | |
284 | ||
f20569fa XL |
285 | /// Checks if the first type parameter is a lang item. |
286 | pub fn is_ty_param_lang_item(cx: &LateContext<'_>, qpath: &QPath<'tcx>, item: LangItem) -> Option<&'tcx hir::Ty<'tcx>> { | |
287 | let ty = get_qpath_generic_tys(qpath).next()?; | |
288 | ||
289 | if let TyKind::Path(qpath) = &ty.kind { | |
290 | cx.qpath_res(qpath, ty.hir_id) | |
291 | .opt_def_id() | |
292 | .map_or(false, |id| { | |
293 | cx.tcx.lang_items().require(item).map_or(false, |lang_id| id == lang_id) | |
294 | }) | |
295 | .then(|| ty) | |
296 | } else { | |
297 | None | |
298 | } | |
299 | } | |
300 | ||
301 | /// Checks if the first type parameter is a diagnostic item. | |
302 | pub fn is_ty_param_diagnostic_item( | |
303 | cx: &LateContext<'_>, | |
304 | qpath: &QPath<'tcx>, | |
305 | item: Symbol, | |
306 | ) -> Option<&'tcx hir::Ty<'tcx>> { | |
307 | let ty = get_qpath_generic_tys(qpath).next()?; | |
308 | ||
309 | if let TyKind::Path(qpath) = &ty.kind { | |
310 | cx.qpath_res(qpath, ty.hir_id) | |
311 | .opt_def_id() | |
312 | .map_or(false, |id| cx.tcx.is_diagnostic_item(item, id)) | |
313 | .then(|| ty) | |
314 | } else { | |
315 | None | |
316 | } | |
317 | } | |
318 | ||
f20569fa | 319 | /// Checks if the method call given in `expr` belongs to the given trait. |
cdc7bbd5 | 320 | /// This is a deprecated function, consider using [`is_trait_method`]. |
f20569fa XL |
321 | pub fn match_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, path: &[&str]) -> bool { |
322 | let def_id = cx.typeck_results().type_dependent_def_id(expr.hir_id).unwrap(); | |
323 | let trt_id = cx.tcx.trait_of_item(def_id); | |
324 | trt_id.map_or(false, |trt_id| match_def_path(cx, trt_id, path)) | |
325 | } | |
326 | ||
cdc7bbd5 XL |
327 | /// Checks if a method is defined in an impl of a diagnostic item |
328 | pub fn is_diag_item_method(cx: &LateContext<'_>, def_id: DefId, diag_item: Symbol) -> bool { | |
329 | if let Some(impl_did) = cx.tcx.impl_of_method(def_id) { | |
330 | if let Some(adt) = cx.tcx.type_of(impl_did).ty_adt_def() { | |
331 | return cx.tcx.is_diagnostic_item(diag_item, adt.did); | |
332 | } | |
333 | } | |
334 | false | |
335 | } | |
336 | ||
337 | /// Checks if a method is in a diagnostic item trait | |
338 | pub fn is_diag_trait_item(cx: &LateContext<'_>, def_id: DefId, diag_item: Symbol) -> bool { | |
339 | if let Some(trait_did) = cx.tcx.trait_of_item(def_id) { | |
340 | return cx.tcx.is_diagnostic_item(diag_item, trait_did); | |
341 | } | |
342 | false | |
343 | } | |
344 | ||
345 | /// Checks if the method call given in `expr` belongs to the given trait. | |
346 | pub fn is_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, diag_item: Symbol) -> bool { | |
347 | cx.typeck_results() | |
348 | .type_dependent_def_id(expr.hir_id) | |
349 | .map_or(false, |did| is_diag_trait_item(cx, did, diag_item)) | |
f20569fa XL |
350 | } |
351 | ||
94222f64 XL |
352 | /// Checks if the given expression is a path referring an item on the trait |
353 | /// that is marked with the given diagnostic item. | |
354 | /// | |
355 | /// For checking method call expressions instead of path expressions, use | |
356 | /// [`is_trait_method`]. | |
357 | /// | |
358 | /// For example, this can be used to find if an expression like `u64::default` | |
359 | /// refers to an item of the trait `Default`, which is associated with the | |
360 | /// `diag_item` of `sym::Default`. | |
361 | pub fn is_trait_item(cx: &LateContext<'_>, expr: &Expr<'_>, diag_item: Symbol) -> bool { | |
362 | if let hir::ExprKind::Path(ref qpath) = expr.kind { | |
363 | cx.qpath_res(qpath, expr.hir_id) | |
364 | .opt_def_id() | |
365 | .map_or(false, |def_id| is_diag_trait_item(cx, def_id, diag_item)) | |
366 | } else { | |
367 | false | |
368 | } | |
369 | } | |
370 | ||
f20569fa XL |
371 | pub fn last_path_segment<'tcx>(path: &QPath<'tcx>) -> &'tcx PathSegment<'tcx> { |
372 | match *path { | |
17df50a5 XL |
373 | QPath::Resolved(_, path) => path.segments.last().expect("A path must have at least one segment"), |
374 | QPath::TypeRelative(_, seg) => seg, | |
f20569fa XL |
375 | QPath::LangItem(..) => panic!("last_path_segment: lang item has no path segments"), |
376 | } | |
377 | } | |
378 | ||
379 | pub fn get_qpath_generics(path: &QPath<'tcx>) -> Option<&'tcx GenericArgs<'tcx>> { | |
380 | match path { | |
381 | QPath::Resolved(_, p) => p.segments.last().and_then(|s| s.args), | |
382 | QPath::TypeRelative(_, s) => s.args, | |
383 | QPath::LangItem(..) => None, | |
384 | } | |
385 | } | |
386 | ||
387 | pub fn get_qpath_generic_tys(path: &QPath<'tcx>) -> impl Iterator<Item = &'tcx hir::Ty<'tcx>> { | |
388 | get_qpath_generics(path) | |
389 | .map_or([].as_ref(), |a| a.args) | |
390 | .iter() | |
391 | .filter_map(|a| { | |
392 | if let hir::GenericArg::Type(ty) = a { | |
393 | Some(ty) | |
394 | } else { | |
395 | None | |
396 | } | |
397 | }) | |
398 | } | |
399 | ||
400 | pub fn single_segment_path<'tcx>(path: &QPath<'tcx>) -> Option<&'tcx PathSegment<'tcx>> { | |
401 | match *path { | |
17df50a5 XL |
402 | QPath::Resolved(_, path) => path.segments.get(0), |
403 | QPath::TypeRelative(_, seg) => Some(seg), | |
f20569fa XL |
404 | QPath::LangItem(..) => None, |
405 | } | |
406 | } | |
407 | ||
cdc7bbd5 XL |
408 | /// THIS METHOD IS DEPRECATED and will eventually be removed since it does not match against the |
409 | /// entire path or resolved `DefId`. Prefer using `match_def_path`. Consider getting a `DefId` from | |
410 | /// `QPath::Resolved.1.res.opt_def_id()`. | |
411 | /// | |
f20569fa XL |
412 | /// Matches a `QPath` against a slice of segment string literals. |
413 | /// | |
414 | /// There is also `match_path` if you are dealing with a `rustc_hir::Path` instead of a | |
415 | /// `rustc_hir::QPath`. | |
416 | /// | |
417 | /// # Examples | |
418 | /// ```rust,ignore | |
419 | /// match_qpath(path, &["std", "rt", "begin_unwind"]) | |
420 | /// ``` | |
421 | pub fn match_qpath(path: &QPath<'_>, segments: &[&str]) -> bool { | |
422 | match *path { | |
17df50a5 XL |
423 | QPath::Resolved(_, path) => match_path(path, segments), |
424 | QPath::TypeRelative(ty, segment) => match ty.kind { | |
f20569fa XL |
425 | TyKind::Path(ref inner_path) => { |
426 | if let [prefix @ .., end] = segments { | |
427 | if match_qpath(inner_path, prefix) { | |
428 | return segment.ident.name.as_str() == *end; | |
429 | } | |
430 | } | |
431 | false | |
432 | }, | |
433 | _ => false, | |
434 | }, | |
435 | QPath::LangItem(..) => false, | |
436 | } | |
437 | } | |
438 | ||
cdc7bbd5 XL |
439 | /// If the expression is a path, resolve it. Otherwise, return `Res::Err`. |
440 | pub fn expr_path_res(cx: &LateContext<'_>, expr: &Expr<'_>) -> Res { | |
441 | if let ExprKind::Path(p) = &expr.kind { | |
442 | cx.qpath_res(p, expr.hir_id) | |
443 | } else { | |
444 | Res::Err | |
445 | } | |
446 | } | |
447 | ||
448 | /// Resolves the path to a `DefId` and checks if it matches the given path. | |
449 | pub fn is_qpath_def_path(cx: &LateContext<'_>, path: &QPath<'_>, hir_id: HirId, segments: &[&str]) -> bool { | |
450 | cx.qpath_res(path, hir_id) | |
451 | .opt_def_id() | |
452 | .map_or(false, |id| match_def_path(cx, id, segments)) | |
453 | } | |
454 | ||
455 | /// If the expression is a path, resolves it to a `DefId` and checks if it matches the given path. | |
94222f64 XL |
456 | /// |
457 | /// Please use `is_expr_diagnostic_item` if the target is a diagnostic item. | |
cdc7bbd5 XL |
458 | pub fn is_expr_path_def_path(cx: &LateContext<'_>, expr: &Expr<'_>, segments: &[&str]) -> bool { |
459 | expr_path_res(cx, expr) | |
460 | .opt_def_id() | |
461 | .map_or(false, |id| match_def_path(cx, id, segments)) | |
462 | } | |
463 | ||
94222f64 XL |
464 | /// If the expression is a path, resolves it to a `DefId` and checks if it matches the given |
465 | /// diagnostic item. | |
466 | pub fn is_expr_diagnostic_item(cx: &LateContext<'_>, expr: &Expr<'_>, diag_item: Symbol) -> bool { | |
467 | expr_path_res(cx, expr) | |
468 | .opt_def_id() | |
469 | .map_or(false, |id| cx.tcx.is_diagnostic_item(diag_item, id)) | |
470 | } | |
471 | ||
cdc7bbd5 XL |
472 | /// THIS METHOD IS DEPRECATED and will eventually be removed since it does not match against the |
473 | /// entire path or resolved `DefId`. Prefer using `match_def_path`. Consider getting a `DefId` from | |
474 | /// `QPath::Resolved.1.res.opt_def_id()`. | |
475 | /// | |
f20569fa XL |
476 | /// Matches a `Path` against a slice of segment string literals. |
477 | /// | |
478 | /// There is also `match_qpath` if you are dealing with a `rustc_hir::QPath` instead of a | |
479 | /// `rustc_hir::Path`. | |
480 | /// | |
481 | /// # Examples | |
482 | /// | |
483 | /// ```rust,ignore | |
484 | /// if match_path(&trait_ref.path, &paths::HASH) { | |
485 | /// // This is the `std::hash::Hash` trait. | |
486 | /// } | |
487 | /// | |
488 | /// if match_path(ty_path, &["rustc", "lint", "Lint"]) { | |
489 | /// // This is a `rustc_middle::lint::Lint`. | |
490 | /// } | |
491 | /// ``` | |
492 | pub fn match_path(path: &Path<'_>, segments: &[&str]) -> bool { | |
493 | path.segments | |
494 | .iter() | |
495 | .rev() | |
496 | .zip(segments.iter().rev()) | |
497 | .all(|(a, b)| a.ident.name.as_str() == *b) | |
498 | } | |
499 | ||
f20569fa XL |
500 | /// If the expression is a path to a local, returns the canonical `HirId` of the local. |
501 | pub fn path_to_local(expr: &Expr<'_>) -> Option<HirId> { | |
17df50a5 | 502 | if let ExprKind::Path(QPath::Resolved(None, path)) = expr.kind { |
f20569fa XL |
503 | if let Res::Local(id) = path.res { |
504 | return Some(id); | |
505 | } | |
506 | } | |
507 | None | |
508 | } | |
509 | ||
510 | /// Returns true if the expression is a path to a local with the specified `HirId`. | |
511 | /// Use this function to see if an expression matches a function argument or a match binding. | |
512 | pub fn path_to_local_id(expr: &Expr<'_>, id: HirId) -> bool { | |
513 | path_to_local(expr) == Some(id) | |
514 | } | |
515 | ||
516 | /// Gets the definition associated to a path. | |
f20569fa XL |
517 | pub fn path_to_res(cx: &LateContext<'_>, path: &[&str]) -> Res { |
518 | macro_rules! try_res { | |
519 | ($e:expr) => { | |
520 | match $e { | |
521 | Some(e) => e, | |
522 | None => return Res::Err, | |
523 | } | |
524 | }; | |
525 | } | |
c295e0f8 | 526 | fn item_child_by_name<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, name: &str) -> Option<&'tcx Export> { |
f20569fa XL |
527 | tcx.item_children(def_id) |
528 | .iter() | |
529 | .find(|item| item.ident.name.as_str() == name) | |
530 | } | |
531 | ||
532 | let (krate, first, path) = match *path { | |
533 | [krate, first, ref path @ ..] => (krate, first, path), | |
94222f64 XL |
534 | [primitive] => { |
535 | return PrimTy::from_name(Symbol::intern(primitive)).map_or(Res::Err, Res::PrimTy); | |
536 | }, | |
f20569fa XL |
537 | _ => return Res::Err, |
538 | }; | |
539 | let tcx = cx.tcx; | |
136023e0 | 540 | let crates = tcx.crates(()); |
f20569fa XL |
541 | let krate = try_res!(crates.iter().find(|&&num| tcx.crate_name(num).as_str() == krate)); |
542 | let first = try_res!(item_child_by_name(tcx, krate.as_def_id(), first)); | |
543 | let last = path | |
544 | .iter() | |
545 | .copied() | |
546 | // `get_def_path` seems to generate these empty segments for extern blocks. | |
547 | // We can just ignore them. | |
548 | .filter(|segment| !segment.is_empty()) | |
549 | // for each segment, find the child item | |
550 | .try_fold(first, |item, segment| { | |
551 | let def_id = item.res.def_id(); | |
552 | if let Some(item) = item_child_by_name(tcx, def_id, segment) { | |
553 | Some(item) | |
554 | } else if matches!(item.res, Res::Def(DefKind::Enum | DefKind::Struct, _)) { | |
555 | // it is not a child item so check inherent impl items | |
556 | tcx.inherent_impls(def_id) | |
557 | .iter() | |
558 | .find_map(|&impl_def_id| item_child_by_name(tcx, impl_def_id, segment)) | |
559 | } else { | |
560 | None | |
561 | } | |
562 | }); | |
c295e0f8 | 563 | try_res!(last).res.expect_non_local() |
f20569fa XL |
564 | } |
565 | ||
566 | /// Convenience function to get the `DefId` of a trait by path. | |
567 | /// It could be a trait or trait alias. | |
568 | pub fn get_trait_def_id(cx: &LateContext<'_>, path: &[&str]) -> Option<DefId> { | |
569 | match path_to_res(cx, path) { | |
570 | Res::Def(DefKind::Trait | DefKind::TraitAlias, trait_id) => Some(trait_id), | |
571 | _ => None, | |
572 | } | |
573 | } | |
574 | ||
f20569fa XL |
575 | /// Gets the `hir::TraitRef` of the trait the given method is implemented for. |
576 | /// | |
577 | /// Use this if you want to find the `TraitRef` of the `Add` trait in this example: | |
578 | /// | |
579 | /// ```rust | |
580 | /// struct Point(isize, isize); | |
581 | /// | |
582 | /// impl std::ops::Add for Point { | |
583 | /// type Output = Self; | |
584 | /// | |
585 | /// fn add(self, other: Self) -> Self { | |
586 | /// Point(0, 0) | |
587 | /// } | |
588 | /// } | |
589 | /// ``` | |
590 | pub fn trait_ref_of_method<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<&'tcx TraitRef<'tcx>> { | |
591 | // Get the implemented trait for the current function | |
592 | let parent_impl = cx.tcx.hir().get_parent_item(hir_id); | |
593 | if_chain! { | |
594 | if parent_impl != hir::CRATE_HIR_ID; | |
595 | if let hir::Node::Item(item) = cx.tcx.hir().get(parent_impl); | |
596 | if let hir::ItemKind::Impl(impl_) = &item.kind; | |
597 | then { return impl_.of_trait.as_ref(); } | |
598 | } | |
599 | None | |
600 | } | |
601 | ||
94222f64 XL |
602 | /// This method will return tuple of projection stack and root of the expression, |
603 | /// used in `can_mut_borrow_both`. | |
604 | /// | |
605 | /// For example, if `e` represents the `v[0].a.b[x]` | |
606 | /// this method will return a tuple, composed of a `Vec` | |
607 | /// containing the `Expr`s for `v[0], v[0].a, v[0].a.b, v[0].a.b[x]` | |
608 | /// and an `Expr` for root of them, `v` | |
609 | fn projection_stack<'a, 'hir>(mut e: &'a Expr<'hir>) -> (Vec<&'a Expr<'hir>>, &'a Expr<'hir>) { | |
610 | let mut result = vec![]; | |
611 | let root = loop { | |
612 | match e.kind { | |
613 | ExprKind::Index(ep, _) | ExprKind::Field(ep, _) => { | |
614 | result.push(e); | |
615 | e = ep; | |
616 | }, | |
617 | _ => break e, | |
618 | }; | |
619 | }; | |
620 | result.reverse(); | |
621 | (result, root) | |
622 | } | |
623 | ||
624 | /// Checks if two expressions can be mutably borrowed simultaneously | |
625 | /// and they aren't dependent on borrowing same thing twice | |
626 | pub fn can_mut_borrow_both(cx: &LateContext<'_>, e1: &Expr<'_>, e2: &Expr<'_>) -> bool { | |
627 | let (s1, r1) = projection_stack(e1); | |
628 | let (s2, r2) = projection_stack(e2); | |
629 | if !eq_expr_value(cx, r1, r2) { | |
630 | return true; | |
631 | } | |
632 | for (x1, x2) in s1.iter().zip(s2.iter()) { | |
633 | match (&x1.kind, &x2.kind) { | |
634 | (ExprKind::Field(_, i1), ExprKind::Field(_, i2)) => { | |
635 | if i1 != i2 { | |
636 | return true; | |
637 | } | |
638 | }, | |
639 | (ExprKind::Index(_, i1), ExprKind::Index(_, i2)) => { | |
640 | if !eq_expr_value(cx, i1, i2) { | |
641 | return false; | |
642 | } | |
643 | }, | |
644 | _ => return false, | |
645 | } | |
646 | } | |
647 | false | |
648 | } | |
649 | ||
c295e0f8 XL |
650 | /// Returns true if the `def_id` associated with the `path` is recognized as a "default-equivalent" |
651 | /// constructor from the std library | |
652 | fn is_default_equivalent_ctor(cx: &LateContext<'_>, def_id: DefId, path: &QPath<'_>) -> bool { | |
653 | let std_types_symbols = &[ | |
654 | sym::String, | |
655 | sym::Vec, | |
656 | sym::VecDeque, | |
657 | sym::LinkedList, | |
658 | sym::HashMap, | |
659 | sym::BTreeMap, | |
660 | sym::HashSet, | |
661 | sym::BTreeSet, | |
662 | sym::BinaryHeap, | |
663 | ]; | |
664 | ||
665 | if let QPath::TypeRelative(_, method) = path { | |
666 | if method.ident.name == sym::new { | |
667 | if let Some(impl_did) = cx.tcx.impl_of_method(def_id) { | |
668 | if let Some(adt) = cx.tcx.type_of(impl_did).ty_adt_def() { | |
669 | return std_types_symbols | |
670 | .iter() | |
671 | .any(|&symbol| cx.tcx.is_diagnostic_item(symbol, adt.did)); | |
672 | } | |
673 | } | |
674 | } | |
675 | } | |
676 | false | |
677 | } | |
678 | ||
a2a8927a XL |
679 | /// Return true if the expr is equal to `Default::default` when evaluated. |
680 | pub fn is_default_equivalent_call(cx: &LateContext<'_>, repl_func: &Expr<'_>) -> bool { | |
681 | if_chain! { | |
682 | if let hir::ExprKind::Path(ref repl_func_qpath) = repl_func.kind; | |
683 | if let Some(repl_def_id) = cx.qpath_res(repl_func_qpath, repl_func.hir_id).opt_def_id(); | |
684 | if is_diag_trait_item(cx, repl_def_id, sym::Default) | |
685 | || is_default_equivalent_ctor(cx, repl_def_id, repl_func_qpath); | |
686 | then { | |
687 | true | |
688 | } | |
689 | else { | |
690 | false | |
691 | } | |
692 | } | |
693 | } | |
694 | ||
c295e0f8 XL |
695 | /// Returns true if the expr is equal to `Default::default()` of it's type when evaluated. |
696 | /// It doesn't cover all cases, for example indirect function calls (some of std | |
697 | /// functions are supported) but it is the best we have. | |
698 | pub fn is_default_equivalent(cx: &LateContext<'_>, e: &Expr<'_>) -> bool { | |
699 | match &e.kind { | |
700 | ExprKind::Lit(lit) => match lit.node { | |
701 | LitKind::Bool(false) | LitKind::Int(0, _) => true, | |
702 | LitKind::Str(s, _) => s.is_empty(), | |
703 | _ => false, | |
704 | }, | |
705 | ExprKind::Tup(items) | ExprKind::Array(items) => items.iter().all(|x| is_default_equivalent(cx, x)), | |
a2a8927a XL |
706 | ExprKind::Repeat(x, len) => if_chain! { |
707 | if let ArrayLen::Body(len) = len; | |
708 | if let ExprKind::Lit(ref const_lit) = cx.tcx.hir().body(len.body).value.kind; | |
c295e0f8 XL |
709 | if let LitKind::Int(v, _) = const_lit.node; |
710 | if v <= 32 && is_default_equivalent(cx, x); | |
711 | then { | |
712 | true | |
713 | } | |
714 | else { | |
715 | false | |
716 | } | |
717 | }, | |
a2a8927a | 718 | ExprKind::Call(repl_func, _) => is_default_equivalent_call(cx, repl_func), |
c295e0f8 XL |
719 | ExprKind::Path(qpath) => is_lang_ctor(cx, qpath, OptionNone), |
720 | ExprKind::AddrOf(rustc_hir::BorrowKind::Ref, _, expr) => matches!(expr.kind, ExprKind::Array([])), | |
721 | _ => false, | |
722 | } | |
723 | } | |
724 | ||
cdc7bbd5 | 725 | /// Checks if the top level expression can be moved into a closure as is. |
c295e0f8 XL |
726 | /// Currently checks for: |
727 | /// * Break/Continue outside the given loop HIR ids. | |
3c0e092e | 728 | /// * Yield/Return statements. |
c295e0f8 XL |
729 | /// * Inline assembly. |
730 | /// * Usages of a field of a local where the type of the local can be partially moved. | |
731 | /// | |
732 | /// For example, given the following function: | |
733 | /// | |
734 | /// ``` | |
735 | /// fn f<'a>(iter: &mut impl Iterator<Item = (usize, &'a mut String)>) { | |
736 | /// for item in iter { | |
737 | /// let s = item.1; | |
738 | /// if item.0 > 10 { | |
739 | /// continue; | |
740 | /// } else { | |
741 | /// s.clear(); | |
742 | /// } | |
743 | /// } | |
744 | /// } | |
745 | /// ``` | |
746 | /// | |
747 | /// When called on the expression `item.0` this will return false unless the local `item` is in the | |
748 | /// `ignore_locals` set. The type `(usize, &mut String)` can have the second element moved, so it | |
749 | /// isn't always safe to move into a closure when only a single field is needed. | |
750 | /// | |
751 | /// When called on the `continue` expression this will return false unless the outer loop expression | |
752 | /// is in the `loop_ids` set. | |
753 | /// | |
754 | /// Note that this check is not recursive, so passing the `if` expression will always return true | |
755 | /// even though sub-expressions might return false. | |
756 | pub fn can_move_expr_to_closure_no_visit( | |
757 | cx: &LateContext<'tcx>, | |
758 | expr: &'tcx Expr<'_>, | |
759 | loop_ids: &[HirId], | |
760 | ignore_locals: &HirIdSet, | |
761 | ) -> bool { | |
cdc7bbd5 XL |
762 | match expr.kind { |
763 | ExprKind::Break(Destination { target_id: Ok(id), .. }, _) | |
764 | | ExprKind::Continue(Destination { target_id: Ok(id), .. }) | |
c295e0f8 | 765 | if loop_ids.contains(&id) => |
cdc7bbd5 XL |
766 | { |
767 | true | |
768 | }, | |
769 | ExprKind::Break(..) | |
770 | | ExprKind::Continue(_) | |
771 | | ExprKind::Ret(_) | |
772 | | ExprKind::Yield(..) | |
773 | | ExprKind::InlineAsm(_) | |
774 | | ExprKind::LlvmInlineAsm(_) => false, | |
775 | // Accessing a field of a local value can only be done if the type isn't | |
776 | // partially moved. | |
c295e0f8 XL |
777 | ExprKind::Field( |
778 | &Expr { | |
779 | hir_id, | |
780 | kind: | |
781 | ExprKind::Path(QPath::Resolved( | |
782 | _, | |
783 | Path { | |
784 | res: Res::Local(local_id), | |
785 | .. | |
786 | }, | |
787 | )), | |
788 | .. | |
789 | }, | |
790 | _, | |
791 | ) if !ignore_locals.contains(local_id) && can_partially_move_ty(cx, cx.typeck_results().node_type(hir_id)) => { | |
cdc7bbd5 XL |
792 | // TODO: check if the local has been partially moved. Assume it has for now. |
793 | false | |
c295e0f8 | 794 | }, |
cdc7bbd5 | 795 | _ => true, |
f20569fa XL |
796 | } |
797 | } | |
798 | ||
c295e0f8 XL |
799 | /// How a local is captured by a closure |
800 | #[derive(Debug, Clone, Copy, PartialEq, Eq)] | |
801 | pub enum CaptureKind { | |
802 | Value, | |
803 | Ref(Mutability), | |
804 | } | |
805 | impl CaptureKind { | |
806 | pub fn is_imm_ref(self) -> bool { | |
807 | self == Self::Ref(Mutability::Not) | |
808 | } | |
809 | } | |
810 | impl std::ops::BitOr for CaptureKind { | |
811 | type Output = Self; | |
812 | fn bitor(self, rhs: Self) -> Self::Output { | |
813 | match (self, rhs) { | |
814 | (CaptureKind::Value, _) | (_, CaptureKind::Value) => CaptureKind::Value, | |
815 | (CaptureKind::Ref(Mutability::Mut), CaptureKind::Ref(_)) | |
816 | | (CaptureKind::Ref(_), CaptureKind::Ref(Mutability::Mut)) => CaptureKind::Ref(Mutability::Mut), | |
817 | (CaptureKind::Ref(Mutability::Not), CaptureKind::Ref(Mutability::Not)) => CaptureKind::Ref(Mutability::Not), | |
818 | } | |
819 | } | |
820 | } | |
821 | impl std::ops::BitOrAssign for CaptureKind { | |
822 | fn bitor_assign(&mut self, rhs: Self) { | |
823 | *self = *self | rhs; | |
824 | } | |
825 | } | |
826 | ||
827 | /// Given an expression referencing a local, determines how it would be captured in a closure. | |
828 | /// Note as this will walk up to parent expressions until the capture can be determined it should | |
829 | /// only be used while making a closure somewhere a value is consumed. e.g. a block, match arm, or | |
830 | /// function argument (other than a receiver). | |
831 | pub fn capture_local_usage(cx: &LateContext<'tcx>, e: &Expr<'_>) -> CaptureKind { | |
832 | fn pat_capture_kind(cx: &LateContext<'_>, pat: &Pat<'_>) -> CaptureKind { | |
833 | let mut capture = CaptureKind::Ref(Mutability::Not); | |
834 | pat.each_binding_or_first(&mut |_, id, span, _| match cx | |
835 | .typeck_results() | |
836 | .extract_binding_mode(cx.sess(), id, span) | |
837 | .unwrap() | |
838 | { | |
839 | BindingMode::BindByValue(_) if !is_copy(cx, cx.typeck_results().node_type(id)) => { | |
840 | capture = CaptureKind::Value; | |
841 | }, | |
842 | BindingMode::BindByReference(Mutability::Mut) if capture != CaptureKind::Value => { | |
843 | capture = CaptureKind::Ref(Mutability::Mut); | |
844 | }, | |
845 | _ => (), | |
846 | }); | |
847 | capture | |
848 | } | |
849 | ||
850 | debug_assert!(matches!( | |
851 | e.kind, | |
852 | ExprKind::Path(QPath::Resolved(None, Path { res: Res::Local(_), .. })) | |
853 | )); | |
854 | ||
855 | let mut child_id = e.hir_id; | |
856 | let mut capture = CaptureKind::Value; | |
857 | let mut capture_expr_ty = e; | |
858 | ||
859 | for (parent_id, parent) in cx.tcx.hir().parent_iter(e.hir_id) { | |
860 | if let [ | |
861 | Adjustment { | |
862 | kind: Adjust::Deref(_) | Adjust::Borrow(AutoBorrow::Ref(..)), | |
863 | target, | |
864 | }, | |
865 | ref adjust @ .., | |
866 | ] = *cx | |
867 | .typeck_results() | |
868 | .adjustments() | |
869 | .get(child_id) | |
870 | .map_or(&[][..], |x| &**x) | |
871 | { | |
872 | if let rustc_ty::RawPtr(TypeAndMut { mutbl: mutability, .. }) | rustc_ty::Ref(_, _, mutability) = | |
873 | *adjust.last().map_or(target, |a| a.target).kind() | |
874 | { | |
875 | return CaptureKind::Ref(mutability); | |
876 | } | |
877 | } | |
878 | ||
879 | match parent { | |
880 | Node::Expr(e) => match e.kind { | |
881 | ExprKind::AddrOf(_, mutability, _) => return CaptureKind::Ref(mutability), | |
882 | ExprKind::Index(..) | ExprKind::Unary(UnOp::Deref, _) => capture = CaptureKind::Ref(Mutability::Not), | |
883 | ExprKind::Assign(lhs, ..) | ExprKind::Assign(_, lhs, _) if lhs.hir_id == child_id => { | |
884 | return CaptureKind::Ref(Mutability::Mut); | |
885 | }, | |
886 | ExprKind::Field(..) => { | |
887 | if capture == CaptureKind::Value { | |
888 | capture_expr_ty = e; | |
889 | } | |
890 | }, | |
a2a8927a XL |
891 | ExprKind::Let(let_expr) => { |
892 | let mutability = match pat_capture_kind(cx, let_expr.pat) { | |
c295e0f8 XL |
893 | CaptureKind::Value => Mutability::Not, |
894 | CaptureKind::Ref(m) => m, | |
895 | }; | |
896 | return CaptureKind::Ref(mutability); | |
897 | }, | |
898 | ExprKind::Match(_, arms, _) => { | |
899 | let mut mutability = Mutability::Not; | |
900 | for capture in arms.iter().map(|arm| pat_capture_kind(cx, arm.pat)) { | |
901 | match capture { | |
902 | CaptureKind::Value => break, | |
903 | CaptureKind::Ref(Mutability::Mut) => mutability = Mutability::Mut, | |
904 | CaptureKind::Ref(Mutability::Not) => (), | |
905 | } | |
906 | } | |
907 | return CaptureKind::Ref(mutability); | |
908 | }, | |
909 | _ => break, | |
910 | }, | |
911 | Node::Local(l) => match pat_capture_kind(cx, l.pat) { | |
912 | CaptureKind::Value => break, | |
913 | capture @ CaptureKind::Ref(_) => return capture, | |
914 | }, | |
915 | _ => break, | |
916 | } | |
917 | ||
918 | child_id = parent_id; | |
919 | } | |
920 | ||
921 | if capture == CaptureKind::Value && is_copy(cx, cx.typeck_results().expr_ty(capture_expr_ty)) { | |
922 | // Copy types are never automatically captured by value. | |
923 | CaptureKind::Ref(Mutability::Not) | |
924 | } else { | |
925 | capture | |
926 | } | |
927 | } | |
928 | ||
929 | /// Checks if the expression can be moved into a closure as is. This will return a list of captures | |
930 | /// if so, otherwise, `None`. | |
931 | pub fn can_move_expr_to_closure(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<HirIdMap<CaptureKind>> { | |
cdc7bbd5 XL |
932 | struct V<'cx, 'tcx> { |
933 | cx: &'cx LateContext<'tcx>, | |
c295e0f8 | 934 | // Stack of potential break targets contained in the expression. |
cdc7bbd5 | 935 | loops: Vec<HirId>, |
c295e0f8 XL |
936 | /// Local variables created in the expression. These don't need to be captured. |
937 | locals: HirIdSet, | |
938 | /// Whether this expression can be turned into a closure. | |
cdc7bbd5 | 939 | allow_closure: bool, |
c295e0f8 XL |
940 | /// Locals which need to be captured, and whether they need to be by value, reference, or |
941 | /// mutable reference. | |
942 | captures: HirIdMap<CaptureKind>, | |
f20569fa | 943 | } |
cdc7bbd5 XL |
944 | impl Visitor<'tcx> for V<'_, 'tcx> { |
945 | type Map = ErasedMap<'tcx>; | |
946 | fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> { | |
947 | NestedVisitorMap::None | |
948 | } | |
949 | ||
950 | fn visit_expr(&mut self, e: &'tcx Expr<'_>) { | |
951 | if !self.allow_closure { | |
952 | return; | |
953 | } | |
c295e0f8 XL |
954 | |
955 | match e.kind { | |
956 | ExprKind::Path(QPath::Resolved(None, &Path { res: Res::Local(l), .. })) => { | |
957 | if !self.locals.contains(&l) { | |
958 | let cap = capture_local_usage(self.cx, e); | |
959 | self.captures.entry(l).and_modify(|e| *e |= cap).or_insert(cap); | |
960 | } | |
961 | }, | |
962 | ExprKind::Closure(..) => { | |
963 | let closure_id = self.cx.tcx.hir().local_def_id(e.hir_id).to_def_id(); | |
964 | for capture in self.cx.typeck_results().closure_min_captures_flattened(closure_id) { | |
965 | let local_id = match capture.place.base { | |
966 | PlaceBase::Local(id) => id, | |
967 | PlaceBase::Upvar(var) => var.var_path.hir_id, | |
968 | _ => continue, | |
969 | }; | |
970 | if !self.locals.contains(&local_id) { | |
971 | let capture = match capture.info.capture_kind { | |
972 | UpvarCapture::ByValue(_) => CaptureKind::Value, | |
973 | UpvarCapture::ByRef(borrow) => match borrow.kind { | |
974 | BorrowKind::ImmBorrow => CaptureKind::Ref(Mutability::Not), | |
975 | BorrowKind::UniqueImmBorrow | BorrowKind::MutBorrow => { | |
976 | CaptureKind::Ref(Mutability::Mut) | |
977 | }, | |
978 | }, | |
979 | }; | |
980 | self.captures | |
981 | .entry(local_id) | |
982 | .and_modify(|e| *e |= capture) | |
983 | .or_insert(capture); | |
984 | } | |
985 | } | |
986 | }, | |
987 | ExprKind::Loop(b, ..) => { | |
988 | self.loops.push(e.hir_id); | |
989 | self.visit_block(b); | |
990 | self.loops.pop(); | |
991 | }, | |
992 | _ => { | |
993 | self.allow_closure &= can_move_expr_to_closure_no_visit(self.cx, e, &self.loops, &self.locals); | |
994 | walk_expr(self, e); | |
995 | }, | |
cdc7bbd5 XL |
996 | } |
997 | } | |
c295e0f8 XL |
998 | |
999 | fn visit_pat(&mut self, p: &'tcx Pat<'tcx>) { | |
1000 | p.each_binding_or_first(&mut |_, id, _, _| { | |
1001 | self.locals.insert(id); | |
1002 | }); | |
1003 | } | |
f20569fa | 1004 | } |
cdc7bbd5 XL |
1005 | |
1006 | let mut v = V { | |
1007 | cx, | |
1008 | allow_closure: true, | |
1009 | loops: Vec::new(), | |
c295e0f8 XL |
1010 | locals: HirIdSet::default(), |
1011 | captures: HirIdMap::default(), | |
cdc7bbd5 XL |
1012 | }; |
1013 | v.visit_expr(expr); | |
c295e0f8 | 1014 | v.allow_closure.then(|| v.captures) |
f20569fa XL |
1015 | } |
1016 | ||
1017 | /// Returns the method names and argument list of nested method call expressions that make up | |
1018 | /// `expr`. method/span lists are sorted with the most recent call first. | |
1019 | pub fn method_calls<'tcx>( | |
1020 | expr: &'tcx Expr<'tcx>, | |
1021 | max_depth: usize, | |
1022 | ) -> (Vec<Symbol>, Vec<&'tcx [Expr<'tcx>]>, Vec<Span>) { | |
1023 | let mut method_names = Vec::with_capacity(max_depth); | |
1024 | let mut arg_lists = Vec::with_capacity(max_depth); | |
1025 | let mut spans = Vec::with_capacity(max_depth); | |
1026 | ||
1027 | let mut current = expr; | |
1028 | for _ in 0..max_depth { | |
1029 | if let ExprKind::MethodCall(path, span, args, _) = ¤t.kind { | |
1030 | if args.iter().any(|e| e.span.from_expansion()) { | |
1031 | break; | |
1032 | } | |
1033 | method_names.push(path.ident.name); | |
1034 | arg_lists.push(&**args); | |
1035 | spans.push(*span); | |
1036 | current = &args[0]; | |
1037 | } else { | |
1038 | break; | |
1039 | } | |
1040 | } | |
1041 | ||
1042 | (method_names, arg_lists, spans) | |
1043 | } | |
1044 | ||
1045 | /// Matches an `Expr` against a chain of methods, and return the matched `Expr`s. | |
1046 | /// | |
1047 | /// For example, if `expr` represents the `.baz()` in `foo.bar().baz()`, | |
1048 | /// `method_chain_args(expr, &["bar", "baz"])` will return a `Vec` | |
1049 | /// containing the `Expr`s for | |
1050 | /// `.bar()` and `.baz()` | |
1051 | pub fn method_chain_args<'a>(expr: &'a Expr<'_>, methods: &[&str]) -> Option<Vec<&'a [Expr<'a>]>> { | |
1052 | let mut current = expr; | |
1053 | let mut matched = Vec::with_capacity(methods.len()); | |
1054 | for method_name in methods.iter().rev() { | |
1055 | // method chains are stored last -> first | |
17df50a5 | 1056 | if let ExprKind::MethodCall(path, _, args, _) = current.kind { |
f20569fa XL |
1057 | if path.ident.name.as_str() == *method_name { |
1058 | if args.iter().any(|e| e.span.from_expansion()) { | |
1059 | return None; | |
1060 | } | |
17df50a5 XL |
1061 | matched.push(args); // build up `matched` backwards |
1062 | current = &args[0]; // go to parent expression | |
f20569fa XL |
1063 | } else { |
1064 | return None; | |
1065 | } | |
1066 | } else { | |
1067 | return None; | |
1068 | } | |
1069 | } | |
1070 | // Reverse `matched` so that it is in the same order as `methods`. | |
1071 | matched.reverse(); | |
1072 | Some(matched) | |
1073 | } | |
1074 | ||
1075 | /// Returns `true` if the provided `def_id` is an entrypoint to a program. | |
1076 | pub fn is_entrypoint_fn(cx: &LateContext<'_>, def_id: DefId) -> bool { | |
1077 | cx.tcx | |
17df50a5 | 1078 | .entry_fn(()) |
cdc7bbd5 | 1079 | .map_or(false, |(entry_fn_def_id, _)| def_id == entry_fn_def_id) |
f20569fa XL |
1080 | } |
1081 | ||
1082 | /// Returns `true` if the expression is in the program's `#[panic_handler]`. | |
1083 | pub fn is_in_panic_handler(cx: &LateContext<'_>, e: &Expr<'_>) -> bool { | |
1084 | let parent = cx.tcx.hir().get_parent_item(e.hir_id); | |
1085 | let def_id = cx.tcx.hir().local_def_id(parent).to_def_id(); | |
1086 | Some(def_id) == cx.tcx.lang_items().panic_impl() | |
1087 | } | |
1088 | ||
1089 | /// Gets the name of the item the expression is in, if available. | |
1090 | pub fn get_item_name(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<Symbol> { | |
1091 | let parent_id = cx.tcx.hir().get_parent_item(expr.hir_id); | |
1092 | match cx.tcx.hir().find(parent_id) { | |
1093 | Some( | |
1094 | Node::Item(Item { ident, .. }) | |
1095 | | Node::TraitItem(TraitItem { ident, .. }) | |
1096 | | Node::ImplItem(ImplItem { ident, .. }), | |
1097 | ) => Some(ident.name), | |
1098 | _ => None, | |
1099 | } | |
1100 | } | |
1101 | ||
cdc7bbd5 XL |
1102 | pub struct ContainsName { |
1103 | pub name: Symbol, | |
1104 | pub result: bool, | |
f20569fa XL |
1105 | } |
1106 | ||
1107 | impl<'tcx> Visitor<'tcx> for ContainsName { | |
1108 | type Map = Map<'tcx>; | |
1109 | ||
1110 | fn visit_name(&mut self, _: Span, name: Symbol) { | |
1111 | if self.name == name { | |
1112 | self.result = true; | |
1113 | } | |
1114 | } | |
1115 | fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> { | |
1116 | NestedVisitorMap::None | |
1117 | } | |
1118 | } | |
1119 | ||
1120 | /// Checks if an `Expr` contains a certain name. | |
1121 | pub fn contains_name(name: Symbol, expr: &Expr<'_>) -> bool { | |
1122 | let mut cn = ContainsName { name, result: false }; | |
1123 | cn.visit_expr(expr); | |
1124 | cn.result | |
1125 | } | |
1126 | ||
1127 | /// Returns `true` if `expr` contains a return expression | |
1128 | pub fn contains_return(expr: &hir::Expr<'_>) -> bool { | |
a2a8927a XL |
1129 | let mut found = false; |
1130 | expr_visitor_no_bodies(|expr| { | |
1131 | if !found { | |
f20569fa | 1132 | if let hir::ExprKind::Ret(..) = &expr.kind { |
a2a8927a | 1133 | found = true; |
f20569fa XL |
1134 | } |
1135 | } | |
a2a8927a XL |
1136 | !found |
1137 | }) | |
1138 | .visit_expr(expr); | |
1139 | found | |
f20569fa XL |
1140 | } |
1141 | ||
1142 | /// Finds calls of the specified macros in a function body. | |
1143 | pub fn find_macro_calls(names: &[&str], body: &Body<'_>) -> Vec<Span> { | |
a2a8927a XL |
1144 | let mut result = Vec::new(); |
1145 | expr_visitor_no_bodies(|expr| { | |
1146 | if names.iter().any(|fun| is_expn_of(expr.span, fun).is_some()) { | |
1147 | result.push(expr.span); | |
1148 | } | |
1149 | true | |
1150 | }) | |
1151 | .visit_expr(&body.value); | |
1152 | result | |
f20569fa XL |
1153 | } |
1154 | ||
f20569fa XL |
1155 | /// Extends the span to the beginning of the spans line, incl. whitespaces. |
1156 | /// | |
a2a8927a | 1157 | /// ```rust |
f20569fa XL |
1158 | /// let x = (); |
1159 | /// // ^^ | |
1160 | /// // will be converted to | |
1161 | /// let x = (); | |
1162 | /// // ^^^^^^^^^^^^^^ | |
1163 | /// ``` | |
1164 | fn line_span<T: LintContext>(cx: &T, span: Span) -> Span { | |
1165 | let span = original_sp(span, DUMMY_SP); | |
1166 | let source_map_and_line = cx.sess().source_map().lookup_line(span.lo()).unwrap(); | |
1167 | let line_no = source_map_and_line.line; | |
1168 | let line_start = source_map_and_line.sf.lines[line_no]; | |
94222f64 | 1169 | span.with_lo(line_start) |
f20569fa XL |
1170 | } |
1171 | ||
cdc7bbd5 XL |
1172 | /// Gets the parent node, if any. |
1173 | pub fn get_parent_node(tcx: TyCtxt<'_>, id: HirId) -> Option<Node<'_>> { | |
1174 | tcx.hir().parent_iter(id).next().map(|(_, node)| node) | |
f20569fa XL |
1175 | } |
1176 | ||
1177 | /// Gets the parent expression, if any –- this is useful to constrain a lint. | |
1178 | pub fn get_parent_expr<'tcx>(cx: &LateContext<'tcx>, e: &Expr<'_>) -> Option<&'tcx Expr<'tcx>> { | |
17df50a5 XL |
1179 | get_parent_expr_for_hir(cx, e.hir_id) |
1180 | } | |
1181 | ||
1182 | /// This retrieves the parent for the given `HirId` if it's an expression. This is useful for | |
1183 | /// constraint lints | |
1184 | pub fn get_parent_expr_for_hir<'tcx>(cx: &LateContext<'tcx>, hir_id: hir::HirId) -> Option<&'tcx Expr<'tcx>> { | |
1185 | match get_parent_node(cx.tcx, hir_id) { | |
cdc7bbd5 XL |
1186 | Some(Node::Expr(parent)) => Some(parent), |
1187 | _ => None, | |
1188 | } | |
f20569fa XL |
1189 | } |
1190 | ||
1191 | pub fn get_enclosing_block<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<&'tcx Block<'tcx>> { | |
1192 | let map = &cx.tcx.hir(); | |
1193 | let enclosing_node = map | |
1194 | .get_enclosing_scope(hir_id) | |
1195 | .and_then(|enclosing_id| map.find(enclosing_id)); | |
1196 | enclosing_node.and_then(|node| match node { | |
1197 | Node::Block(block) => Some(block), | |
1198 | Node::Item(&Item { | |
1199 | kind: ItemKind::Fn(_, _, eid), | |
1200 | .. | |
1201 | }) | |
1202 | | Node::ImplItem(&ImplItem { | |
1203 | kind: ImplItemKind::Fn(_, eid), | |
1204 | .. | |
1205 | }) => match cx.tcx.hir().body(eid).value.kind { | |
17df50a5 | 1206 | ExprKind::Block(block, _) => Some(block), |
f20569fa XL |
1207 | _ => None, |
1208 | }, | |
1209 | _ => None, | |
1210 | }) | |
1211 | } | |
1212 | ||
136023e0 XL |
1213 | /// Gets the loop or closure enclosing the given expression, if any. |
1214 | pub fn get_enclosing_loop_or_closure(tcx: TyCtxt<'tcx>, expr: &Expr<'_>) -> Option<&'tcx Expr<'tcx>> { | |
c295e0f8 | 1215 | for (_, node) in tcx.hir().parent_iter(expr.hir_id) { |
17df50a5 XL |
1216 | match node { |
1217 | Node::Expr( | |
c295e0f8 | 1218 | e @ Expr { |
136023e0 | 1219 | kind: ExprKind::Loop(..) | ExprKind::Closure(..), |
17df50a5 XL |
1220 | .. |
1221 | }, | |
1222 | ) => return Some(e), | |
1223 | Node::Expr(_) | Node::Stmt(_) | Node::Block(_) | Node::Local(_) | Node::Arm(_) => (), | |
1224 | _ => break, | |
1225 | } | |
1226 | } | |
1227 | None | |
1228 | } | |
1229 | ||
f20569fa XL |
1230 | /// Gets the parent node if it's an impl block. |
1231 | pub fn get_parent_as_impl(tcx: TyCtxt<'_>, id: HirId) -> Option<&Impl<'_>> { | |
c295e0f8 | 1232 | match tcx.hir().parent_iter(id).next() { |
f20569fa XL |
1233 | Some(( |
1234 | _, | |
1235 | Node::Item(Item { | |
1236 | kind: ItemKind::Impl(imp), | |
1237 | .. | |
1238 | }), | |
1239 | )) => Some(imp), | |
1240 | _ => None, | |
1241 | } | |
1242 | } | |
1243 | ||
a2a8927a XL |
1244 | /// Removes blocks around an expression, only if the block contains just one expression |
1245 | /// and no statements. Unsafe blocks are not removed. | |
1246 | /// | |
1247 | /// Examples: | |
1248 | /// * `{}` -> `{}` | |
1249 | /// * `{ x }` -> `x` | |
1250 | /// * `{{ x }}` -> `x` | |
1251 | /// * `{ x; }` -> `{ x; }` | |
1252 | /// * `{ x; y }` -> `{ x; y }` | |
1253 | /// * `{ unsafe { x } }` -> `unsafe { x }` | |
1254 | pub fn peel_blocks<'a>(mut expr: &'a Expr<'a>) -> &'a Expr<'a> { | |
1255 | while let ExprKind::Block( | |
1256 | Block { | |
1257 | stmts: [], | |
1258 | expr: Some(inner), | |
1259 | rules: BlockCheckMode::DefaultBlock, | |
1260 | .. | |
1261 | }, | |
1262 | _, | |
1263 | ) = expr.kind | |
1264 | { | |
1265 | expr = inner; | |
1266 | } | |
1267 | expr | |
1268 | } | |
1269 | ||
1270 | /// Removes blocks around an expression, only if the block contains just one expression | |
1271 | /// or just one expression statement with a semicolon. Unsafe blocks are not removed. | |
1272 | /// | |
1273 | /// Examples: | |
1274 | /// * `{}` -> `{}` | |
1275 | /// * `{ x }` -> `x` | |
1276 | /// * `{ x; }` -> `x` | |
1277 | /// * `{{ x; }}` -> `x` | |
1278 | /// * `{ x; y }` -> `{ x; y }` | |
1279 | /// * `{ unsafe { x } }` -> `unsafe { x }` | |
1280 | pub fn peel_blocks_with_stmt<'a>(mut expr: &'a Expr<'a>) -> &'a Expr<'a> { | |
1281 | while let ExprKind::Block( | |
1282 | Block { | |
1283 | stmts: [], | |
1284 | expr: Some(inner), | |
1285 | rules: BlockCheckMode::DefaultBlock, | |
1286 | .. | |
1287 | } | |
1288 | | Block { | |
1289 | stmts: | |
1290 | [ | |
1291 | Stmt { | |
1292 | kind: StmtKind::Expr(inner) | StmtKind::Semi(inner), | |
1293 | .. | |
1294 | }, | |
1295 | ], | |
1296 | expr: None, | |
1297 | rules: BlockCheckMode::DefaultBlock, | |
1298 | .. | |
1299 | }, | |
1300 | _, | |
1301 | ) = expr.kind | |
1302 | { | |
1303 | expr = inner; | |
1304 | } | |
1305 | expr | |
1306 | } | |
1307 | ||
cdc7bbd5 XL |
1308 | /// Checks if the given expression is the else clause of either an `if` or `if let` expression. |
1309 | pub fn is_else_clause(tcx: TyCtxt<'_>, expr: &Expr<'_>) -> bool { | |
c295e0f8 | 1310 | let mut iter = tcx.hir().parent_iter(expr.hir_id); |
cdc7bbd5 | 1311 | match iter.next() { |
cdc7bbd5 XL |
1312 | Some(( |
1313 | _, | |
1314 | Node::Expr(Expr { | |
1315 | kind: ExprKind::If(_, _, Some(else_expr)), | |
1316 | .. | |
1317 | }), | |
1318 | )) => else_expr.hir_id == expr.hir_id, | |
1319 | _ => false, | |
f20569fa | 1320 | } |
f20569fa XL |
1321 | } |
1322 | ||
1323 | /// Checks whether the given expression is a constant integer of the given value. | |
1324 | /// unlike `is_integer_literal`, this version does const folding | |
1325 | pub fn is_integer_const(cx: &LateContext<'_>, e: &Expr<'_>, value: u128) -> bool { | |
1326 | if is_integer_literal(e, value) { | |
1327 | return true; | |
1328 | } | |
136023e0 XL |
1329 | let enclosing_body = cx.tcx.hir().local_def_id(cx.tcx.hir().enclosing_body_owner(e.hir_id)); |
1330 | if let Some((Constant::Int(v), _)) = constant(cx, cx.tcx.typeck(enclosing_body), e) { | |
3c0e092e | 1331 | return value == v; |
f20569fa | 1332 | } |
3c0e092e | 1333 | false |
f20569fa XL |
1334 | } |
1335 | ||
1336 | /// Checks whether the given expression is a constant literal of the given value. | |
1337 | pub fn is_integer_literal(expr: &Expr<'_>, value: u128) -> bool { | |
1338 | // FIXME: use constant folding | |
1339 | if let ExprKind::Lit(ref spanned) = expr.kind { | |
1340 | if let LitKind::Int(v, _) = spanned.node { | |
1341 | return v == value; | |
1342 | } | |
1343 | } | |
1344 | false | |
1345 | } | |
1346 | ||
1347 | /// Returns `true` if the given `Expr` has been coerced before. | |
1348 | /// | |
1349 | /// Examples of coercions can be found in the Nomicon at | |
1350 | /// <https://doc.rust-lang.org/nomicon/coercions.html>. | |
1351 | /// | |
1352 | /// See `rustc_middle::ty::adjustment::Adjustment` and `rustc_typeck::check::coercion` for more | |
1353 | /// information on adjustments and coercions. | |
1354 | pub fn is_adjusted(cx: &LateContext<'_>, e: &Expr<'_>) -> bool { | |
1355 | cx.typeck_results().adjustments().get(e.hir_id).is_some() | |
1356 | } | |
1357 | ||
a2a8927a | 1358 | /// Returns the pre-expansion span if this comes from an expansion of the |
f20569fa | 1359 | /// macro `name`. |
3c0e092e | 1360 | /// See also [`is_direct_expn_of`]. |
f20569fa XL |
1361 | #[must_use] |
1362 | pub fn is_expn_of(mut span: Span, name: &str) -> Option<Span> { | |
1363 | loop { | |
1364 | if span.from_expansion() { | |
1365 | let data = span.ctxt().outer_expn_data(); | |
1366 | let new_span = data.call_site; | |
1367 | ||
136023e0 | 1368 | if let ExpnKind::Macro(MacroKind::Bang, mac_name) = data.kind { |
f20569fa XL |
1369 | if mac_name.as_str() == name { |
1370 | return Some(new_span); | |
1371 | } | |
1372 | } | |
1373 | ||
1374 | span = new_span; | |
1375 | } else { | |
1376 | return None; | |
1377 | } | |
1378 | } | |
1379 | } | |
1380 | ||
1381 | /// Returns the pre-expansion span if the span directly comes from an expansion | |
1382 | /// of the macro `name`. | |
3c0e092e XL |
1383 | /// The difference with [`is_expn_of`] is that in |
1384 | /// ```rust | |
a2a8927a XL |
1385 | /// # macro_rules! foo { ($name:tt!$args:tt) => { $name!$args } } |
1386 | /// # macro_rules! bar { ($e:expr) => { $e } } | |
f20569fa XL |
1387 | /// foo!(bar!(42)); |
1388 | /// ``` | |
1389 | /// `42` is considered expanded from `foo!` and `bar!` by `is_expn_of` but only | |
3c0e092e | 1390 | /// from `bar!` by `is_direct_expn_of`. |
f20569fa XL |
1391 | #[must_use] |
1392 | pub fn is_direct_expn_of(span: Span, name: &str) -> Option<Span> { | |
1393 | if span.from_expansion() { | |
1394 | let data = span.ctxt().outer_expn_data(); | |
1395 | let new_span = data.call_site; | |
1396 | ||
136023e0 | 1397 | if let ExpnKind::Macro(MacroKind::Bang, mac_name) = data.kind { |
f20569fa XL |
1398 | if mac_name.as_str() == name { |
1399 | return Some(new_span); | |
1400 | } | |
1401 | } | |
1402 | } | |
1403 | ||
1404 | None | |
1405 | } | |
1406 | ||
1407 | /// Convenience function to get the return type of a function. | |
1408 | pub fn return_ty<'tcx>(cx: &LateContext<'tcx>, fn_item: hir::HirId) -> Ty<'tcx> { | |
1409 | let fn_def_id = cx.tcx.hir().local_def_id(fn_item); | |
1410 | let ret_ty = cx.tcx.fn_sig(fn_def_id).output(); | |
1411 | cx.tcx.erase_late_bound_regions(ret_ty) | |
1412 | } | |
1413 | ||
a2a8927a XL |
1414 | /// Convenience function to get the nth argument type of a function. |
1415 | pub fn nth_arg<'tcx>(cx: &LateContext<'tcx>, fn_item: hir::HirId, nth: usize) -> Ty<'tcx> { | |
1416 | let fn_def_id = cx.tcx.hir().local_def_id(fn_item); | |
1417 | let arg = cx.tcx.fn_sig(fn_def_id).input(nth); | |
1418 | cx.tcx.erase_late_bound_regions(arg) | |
1419 | } | |
1420 | ||
f20569fa XL |
1421 | /// Checks if an expression is constructing a tuple-like enum variant or struct |
1422 | pub fn is_ctor_or_promotable_const_function(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { | |
17df50a5 | 1423 | if let ExprKind::Call(fun, _) = expr.kind { |
f20569fa XL |
1424 | if let ExprKind::Path(ref qp) = fun.kind { |
1425 | let res = cx.qpath_res(qp, fun.hir_id); | |
1426 | return match res { | |
1427 | def::Res::Def(DefKind::Variant | DefKind::Ctor(..), ..) => true, | |
1428 | def::Res::Def(_, def_id) => cx.tcx.is_promotable_const_fn(def_id), | |
1429 | _ => false, | |
1430 | }; | |
1431 | } | |
1432 | } | |
1433 | false | |
1434 | } | |
1435 | ||
1436 | /// Returns `true` if a pattern is refutable. | |
1437 | // TODO: should be implemented using rustc/mir_build/thir machinery | |
1438 | pub fn is_refutable(cx: &LateContext<'_>, pat: &Pat<'_>) -> bool { | |
1439 | fn is_enum_variant(cx: &LateContext<'_>, qpath: &QPath<'_>, id: HirId) -> bool { | |
1440 | matches!( | |
1441 | cx.qpath_res(qpath, id), | |
1442 | def::Res::Def(DefKind::Variant, ..) | Res::Def(DefKind::Ctor(def::CtorOf::Variant, _), _) | |
1443 | ) | |
1444 | } | |
1445 | ||
136023e0 XL |
1446 | fn are_refutable<'a, I: IntoIterator<Item = &'a Pat<'a>>>(cx: &LateContext<'_>, i: I) -> bool { |
1447 | i.into_iter().any(|pat| is_refutable(cx, pat)) | |
f20569fa XL |
1448 | } |
1449 | ||
1450 | match pat.kind { | |
1451 | PatKind::Wild => false, | |
1452 | PatKind::Binding(_, _, _, pat) => pat.map_or(false, |pat| is_refutable(cx, pat)), | |
17df50a5 | 1453 | PatKind::Box(pat) | PatKind::Ref(pat, _) => is_refutable(cx, pat), |
f20569fa XL |
1454 | PatKind::Lit(..) | PatKind::Range(..) => true, |
1455 | PatKind::Path(ref qpath) => is_enum_variant(cx, qpath, pat.hir_id), | |
17df50a5 | 1456 | PatKind::Or(pats) => { |
f20569fa | 1457 | // TODO: should be the honest check, that pats is exhaustive set |
136023e0 | 1458 | are_refutable(cx, pats) |
f20569fa | 1459 | }, |
136023e0 | 1460 | PatKind::Tuple(pats, _) => are_refutable(cx, pats), |
17df50a5 | 1461 | PatKind::Struct(ref qpath, fields, _) => { |
f20569fa XL |
1462 | is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, fields.iter().map(|field| &*field.pat)) |
1463 | }, | |
136023e0 XL |
1464 | PatKind::TupleStruct(ref qpath, pats, _) => is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, pats), |
1465 | PatKind::Slice(head, middle, tail) => { | |
f20569fa | 1466 | match &cx.typeck_results().node_type(pat.hir_id).kind() { |
cdc7bbd5 | 1467 | rustc_ty::Slice(..) => { |
f20569fa XL |
1468 | // [..] is the only irrefutable slice pattern. |
1469 | !head.is_empty() || middle.is_none() || !tail.is_empty() | |
1470 | }, | |
136023e0 | 1471 | rustc_ty::Array(..) => are_refutable(cx, head.iter().chain(middle).chain(tail.iter())), |
f20569fa XL |
1472 | _ => { |
1473 | // unreachable!() | |
1474 | true | |
1475 | }, | |
1476 | } | |
1477 | }, | |
1478 | } | |
1479 | } | |
1480 | ||
cdc7bbd5 XL |
1481 | /// If the pattern is an `or` pattern, call the function once for each sub pattern. Otherwise, call |
1482 | /// the function once on the given pattern. | |
1483 | pub fn recurse_or_patterns<'tcx, F: FnMut(&'tcx Pat<'tcx>)>(pat: &'tcx Pat<'tcx>, mut f: F) { | |
1484 | if let PatKind::Or(pats) = pat.kind { | |
136023e0 | 1485 | pats.iter().for_each(f); |
cdc7bbd5 | 1486 | } else { |
17df50a5 | 1487 | f(pat); |
cdc7bbd5 XL |
1488 | } |
1489 | } | |
1490 | ||
f20569fa XL |
1491 | /// Checks for the `#[automatically_derived]` attribute all `#[derive]`d |
1492 | /// implementations have. | |
1493 | pub fn is_automatically_derived(attrs: &[ast::Attribute]) -> bool { | |
a2a8927a | 1494 | has_attr(attrs, sym::automatically_derived) |
f20569fa XL |
1495 | } |
1496 | ||
1497 | pub fn is_self(slf: &Param<'_>) -> bool { | |
1498 | if let PatKind::Binding(.., name, _) = slf.pat.kind { | |
1499 | name.name == kw::SelfLower | |
1500 | } else { | |
1501 | false | |
1502 | } | |
1503 | } | |
1504 | ||
1505 | pub fn is_self_ty(slf: &hir::Ty<'_>) -> bool { | |
3c0e092e XL |
1506 | if let TyKind::Path(QPath::Resolved(None, path)) = slf.kind { |
1507 | if let Res::SelfTy(..) = path.res { | |
1508 | return true; | |
f20569fa XL |
1509 | } |
1510 | } | |
1511 | false | |
1512 | } | |
1513 | ||
1514 | pub fn iter_input_pats<'tcx>(decl: &FnDecl<'_>, body: &'tcx Body<'_>) -> impl Iterator<Item = &'tcx Param<'tcx>> { | |
1515 | (0..decl.inputs.len()).map(move |i| &body.params[i]) | |
1516 | } | |
1517 | ||
1518 | /// Checks if a given expression is a match expression expanded from the `?` | |
1519 | /// operator or the `try` macro. | |
cdc7bbd5 XL |
1520 | pub fn is_try<'tcx>(cx: &LateContext<'_>, expr: &'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> { |
1521 | fn is_ok(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool { | |
f20569fa | 1522 | if_chain! { |
17df50a5 | 1523 | if let PatKind::TupleStruct(ref path, pat, None) = arm.pat.kind; |
cdc7bbd5 | 1524 | if is_lang_ctor(cx, path, ResultOk); |
f20569fa XL |
1525 | if let PatKind::Binding(_, hir_id, _, None) = pat[0].kind; |
1526 | if path_to_local_id(arm.body, hir_id); | |
1527 | then { | |
1528 | return true; | |
1529 | } | |
1530 | } | |
1531 | false | |
1532 | } | |
1533 | ||
cdc7bbd5 | 1534 | fn is_err(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool { |
f20569fa | 1535 | if let PatKind::TupleStruct(ref path, _, _) = arm.pat.kind { |
cdc7bbd5 | 1536 | is_lang_ctor(cx, path, ResultErr) |
f20569fa XL |
1537 | } else { |
1538 | false | |
1539 | } | |
1540 | } | |
1541 | ||
17df50a5 | 1542 | if let ExprKind::Match(_, arms, ref source) = expr.kind { |
f20569fa | 1543 | // desugared from a `?` operator |
c295e0f8 | 1544 | if *source == MatchSource::TryDesugar { |
f20569fa XL |
1545 | return Some(expr); |
1546 | } | |
1547 | ||
1548 | if_chain! { | |
1549 | if arms.len() == 2; | |
1550 | if arms[0].guard.is_none(); | |
1551 | if arms[1].guard.is_none(); | |
cdc7bbd5 XL |
1552 | if (is_ok(cx, &arms[0]) && is_err(cx, &arms[1])) || |
1553 | (is_ok(cx, &arms[1]) && is_err(cx, &arms[0])); | |
f20569fa XL |
1554 | then { |
1555 | return Some(expr); | |
1556 | } | |
1557 | } | |
1558 | } | |
1559 | ||
1560 | None | |
1561 | } | |
1562 | ||
1563 | /// Returns `true` if the lint is allowed in the current context | |
1564 | /// | |
1565 | /// Useful for skipping long running code when it's unnecessary | |
136023e0 | 1566 | pub fn is_lint_allowed(cx: &LateContext<'_>, lint: &'static Lint, id: HirId) -> bool { |
f20569fa XL |
1567 | cx.tcx.lint_level_at_node(lint, id).0 == Level::Allow |
1568 | } | |
1569 | ||
1570 | pub fn strip_pat_refs<'hir>(mut pat: &'hir Pat<'hir>) -> &'hir Pat<'hir> { | |
1571 | while let PatKind::Ref(subpat, _) = pat.kind { | |
1572 | pat = subpat; | |
1573 | } | |
1574 | pat | |
1575 | } | |
1576 | ||
cdc7bbd5 | 1577 | pub fn int_bits(tcx: TyCtxt<'_>, ity: rustc_ty::IntTy) -> u64 { |
f20569fa XL |
1578 | Integer::from_int_ty(&tcx, ity).size().bits() |
1579 | } | |
1580 | ||
1581 | #[allow(clippy::cast_possible_wrap)] | |
1582 | /// Turn a constant int byte representation into an i128 | |
cdc7bbd5 | 1583 | pub fn sext(tcx: TyCtxt<'_>, u: u128, ity: rustc_ty::IntTy) -> i128 { |
f20569fa XL |
1584 | let amt = 128 - int_bits(tcx, ity); |
1585 | ((u as i128) << amt) >> amt | |
1586 | } | |
1587 | ||
1588 | #[allow(clippy::cast_sign_loss)] | |
1589 | /// clip unused bytes | |
cdc7bbd5 | 1590 | pub fn unsext(tcx: TyCtxt<'_>, u: i128, ity: rustc_ty::IntTy) -> u128 { |
f20569fa XL |
1591 | let amt = 128 - int_bits(tcx, ity); |
1592 | ((u as u128) << amt) >> amt | |
1593 | } | |
1594 | ||
1595 | /// clip unused bytes | |
cdc7bbd5 | 1596 | pub fn clip(tcx: TyCtxt<'_>, u: u128, ity: rustc_ty::UintTy) -> u128 { |
f20569fa XL |
1597 | let bits = Integer::from_uint_ty(&tcx, ity).size().bits(); |
1598 | let amt = 128 - bits; | |
1599 | (u << amt) >> amt | |
1600 | } | |
1601 | ||
a2a8927a XL |
1602 | pub fn has_attr(attrs: &[ast::Attribute], symbol: Symbol) -> bool { |
1603 | attrs.iter().any(|attr| attr.has_name(symbol)) | |
1604 | } | |
1605 | ||
1606 | pub fn any_parent_has_attr(tcx: TyCtxt<'_>, node: HirId, symbol: Symbol) -> bool { | |
f20569fa XL |
1607 | let map = &tcx.hir(); |
1608 | let mut prev_enclosing_node = None; | |
1609 | let mut enclosing_node = node; | |
1610 | while Some(enclosing_node) != prev_enclosing_node { | |
a2a8927a | 1611 | if has_attr(map.attrs(enclosing_node), symbol) { |
f20569fa XL |
1612 | return true; |
1613 | } | |
1614 | prev_enclosing_node = Some(enclosing_node); | |
1615 | enclosing_node = map.get_parent_item(enclosing_node); | |
1616 | } | |
a2a8927a | 1617 | |
f20569fa XL |
1618 | false |
1619 | } | |
1620 | ||
a2a8927a XL |
1621 | pub fn any_parent_is_automatically_derived(tcx: TyCtxt<'_>, node: HirId) -> bool { |
1622 | any_parent_has_attr(tcx, node, sym::automatically_derived) | |
1623 | } | |
1624 | ||
f20569fa XL |
1625 | /// Matches a function call with the given path and returns the arguments. |
1626 | /// | |
1627 | /// Usage: | |
1628 | /// | |
1629 | /// ```rust,ignore | |
1630 | /// if let Some(args) = match_function_call(cx, cmp_max_call, &paths::CMP_MAX); | |
1631 | /// ``` | |
1632 | pub fn match_function_call<'tcx>( | |
1633 | cx: &LateContext<'tcx>, | |
1634 | expr: &'tcx Expr<'_>, | |
1635 | path: &[&str], | |
1636 | ) -> Option<&'tcx [Expr<'tcx>]> { | |
1637 | if_chain! { | |
17df50a5 | 1638 | if let ExprKind::Call(fun, args) = expr.kind; |
f20569fa XL |
1639 | if let ExprKind::Path(ref qpath) = fun.kind; |
1640 | if let Some(fun_def_id) = cx.qpath_res(qpath, fun.hir_id).opt_def_id(); | |
1641 | if match_def_path(cx, fun_def_id, path); | |
1642 | then { | |
17df50a5 | 1643 | return Some(args) |
f20569fa XL |
1644 | } |
1645 | }; | |
1646 | None | |
1647 | } | |
1648 | ||
cdc7bbd5 XL |
1649 | /// Checks if the given `DefId` matches any of the paths. Returns the index of matching path, if |
1650 | /// any. | |
94222f64 XL |
1651 | /// |
1652 | /// Please use `match_any_diagnostic_items` if the targets are all diagnostic items. | |
cdc7bbd5 XL |
1653 | pub fn match_any_def_paths(cx: &LateContext<'_>, did: DefId, paths: &[&[&str]]) -> Option<usize> { |
1654 | let search_path = cx.get_def_path(did); | |
1655 | paths | |
1656 | .iter() | |
1657 | .position(|p| p.iter().map(|x| Symbol::intern(x)).eq(search_path.iter().copied())) | |
f20569fa XL |
1658 | } |
1659 | ||
94222f64 XL |
1660 | /// Checks if the given `DefId` matches any of provided diagnostic items. Returns the index of |
1661 | /// matching path, if any. | |
1662 | pub fn match_any_diagnostic_items(cx: &LateContext<'_>, def_id: DefId, diag_items: &[Symbol]) -> Option<usize> { | |
1663 | diag_items | |
1664 | .iter() | |
1665 | .position(|item| cx.tcx.is_diagnostic_item(*item, def_id)) | |
1666 | } | |
1667 | ||
cdc7bbd5 | 1668 | /// Checks if the given `DefId` matches the path. |
f20569fa | 1669 | pub fn match_def_path<'tcx>(cx: &LateContext<'tcx>, did: DefId, syms: &[&str]) -> bool { |
cdc7bbd5 XL |
1670 | // We should probably move to Symbols in Clippy as well rather than interning every time. |
1671 | let path = cx.get_def_path(did); | |
1672 | syms.iter().map(|x| Symbol::intern(x)).eq(path.iter().copied()) | |
f20569fa XL |
1673 | } |
1674 | ||
a2a8927a XL |
1675 | /// Checks if the given `DefId` matches the `libc` item. |
1676 | pub fn match_libc_symbol(cx: &LateContext<'_>, did: DefId, name: &str) -> bool { | |
1677 | let path = cx.get_def_path(did); | |
1678 | // libc is meant to be used as a flat list of names, but they're all actually defined in different | |
1679 | // modules based on the target platform. Ignore everything but crate name and the item name. | |
1680 | path.first().map_or(false, |s| s.as_str() == "libc") && path.last().map_or(false, |s| s.as_str() == name) | |
1681 | } | |
1682 | ||
cdc7bbd5 XL |
1683 | pub fn match_panic_call(cx: &LateContext<'_>, expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> { |
1684 | if let ExprKind::Call(func, [arg]) = expr.kind { | |
1685 | expr_path_res(cx, func) | |
1686 | .opt_def_id() | |
1687 | .map_or(false, |id| match_panic_def_id(cx, id)) | |
1688 | .then(|| arg) | |
1689 | } else { | |
1690 | None | |
1691 | } | |
f20569fa XL |
1692 | } |
1693 | ||
1694 | pub fn match_panic_def_id(cx: &LateContext<'_>, did: DefId) -> bool { | |
cdc7bbd5 XL |
1695 | match_any_def_paths( |
1696 | cx, | |
1697 | did, | |
1698 | &[ | |
1699 | &paths::BEGIN_PANIC, | |
cdc7bbd5 XL |
1700 | &paths::PANIC_ANY, |
1701 | &paths::PANICKING_PANIC, | |
1702 | &paths::PANICKING_PANIC_FMT, | |
1703 | &paths::PANICKING_PANIC_STR, | |
1704 | ], | |
1705 | ) | |
1706 | .is_some() | |
f20569fa XL |
1707 | } |
1708 | ||
1709 | /// Returns the list of condition expressions and the list of blocks in a | |
1710 | /// sequence of `if/else`. | |
1711 | /// E.g., this returns `([a, b], [c, d, e])` for the expression | |
1712 | /// `if a { c } else if b { d } else { e }`. | |
cdc7bbd5 XL |
1713 | pub fn if_sequence<'tcx>(mut expr: &'tcx Expr<'tcx>) -> (Vec<&'tcx Expr<'tcx>>, Vec<&'tcx Block<'tcx>>) { |
1714 | let mut conds = Vec::new(); | |
1715 | let mut blocks: Vec<&Block<'_>> = Vec::new(); | |
f20569fa | 1716 | |
94222f64 XL |
1717 | while let Some(higher::IfOrIfLet { cond, then, r#else }) = higher::IfOrIfLet::hir(expr) { |
1718 | conds.push(&*cond); | |
c295e0f8 | 1719 | if let ExprKind::Block(block, _) = then.kind { |
f20569fa XL |
1720 | blocks.push(block); |
1721 | } else { | |
1722 | panic!("ExprKind::If node is not an ExprKind::Block"); | |
1723 | } | |
1724 | ||
c295e0f8 | 1725 | if let Some(else_expr) = r#else { |
f20569fa XL |
1726 | expr = else_expr; |
1727 | } else { | |
1728 | break; | |
1729 | } | |
1730 | } | |
1731 | ||
1732 | // final `else {..}` | |
1733 | if !blocks.is_empty() { | |
17df50a5 XL |
1734 | if let ExprKind::Block(block, _) = expr.kind { |
1735 | blocks.push(block); | |
f20569fa XL |
1736 | } |
1737 | } | |
1738 | ||
1739 | (conds, blocks) | |
1740 | } | |
1741 | ||
17df50a5 XL |
1742 | /// Checks if the given function kind is an async function. |
1743 | pub fn is_async_fn(kind: FnKind<'_>) -> bool { | |
1744 | matches!(kind, FnKind::ItemFn(_, _, header, _) if header.asyncness == IsAsync::Async) | |
1745 | } | |
1746 | ||
1747 | /// Peels away all the compiler generated code surrounding the body of an async function, | |
1748 | pub fn get_async_fn_body(tcx: TyCtxt<'tcx>, body: &Body<'_>) -> Option<&'tcx Expr<'tcx>> { | |
1749 | if let ExprKind::Call( | |
1750 | _, | |
c295e0f8 XL |
1751 | &[ |
1752 | Expr { | |
1753 | kind: ExprKind::Closure(_, _, body, _, _), | |
1754 | .. | |
1755 | }, | |
1756 | ], | |
17df50a5 XL |
1757 | ) = body.value.kind |
1758 | { | |
1759 | if let ExprKind::Block( | |
1760 | Block { | |
1761 | stmts: [], | |
1762 | expr: | |
1763 | Some(Expr { | |
1764 | kind: ExprKind::DropTemps(expr), | |
1765 | .. | |
1766 | }), | |
1767 | .. | |
1768 | }, | |
1769 | _, | |
1770 | ) = tcx.hir().body(body).value.kind | |
1771 | { | |
1772 | return Some(expr); | |
1773 | } | |
1774 | }; | |
1775 | None | |
1776 | } | |
1777 | ||
f20569fa XL |
1778 | // Finds the `#[must_use]` attribute, if any |
1779 | pub fn must_use_attr(attrs: &[Attribute]) -> Option<&Attribute> { | |
cdc7bbd5 | 1780 | attrs.iter().find(|a| a.has_name(sym::must_use)) |
f20569fa XL |
1781 | } |
1782 | ||
1783 | // check if expr is calling method or function with #[must_use] attribute | |
1784 | pub fn is_must_use_func_call(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { | |
1785 | let did = match expr.kind { | |
17df50a5 | 1786 | ExprKind::Call(path, _) => if_chain! { |
f20569fa XL |
1787 | if let ExprKind::Path(ref qpath) = path.kind; |
1788 | if let def::Res::Def(_, did) = cx.qpath_res(qpath, path.hir_id); | |
1789 | then { | |
1790 | Some(did) | |
1791 | } else { | |
1792 | None | |
1793 | } | |
1794 | }, | |
1795 | ExprKind::MethodCall(_, _, _, _) => cx.typeck_results().type_dependent_def_id(expr.hir_id), | |
1796 | _ => None, | |
1797 | }; | |
1798 | ||
17df50a5 | 1799 | did.map_or(false, |did| must_use_attr(cx.tcx.get_attrs(did)).is_some()) |
f20569fa XL |
1800 | } |
1801 | ||
136023e0 XL |
1802 | /// Checks if an expression represents the identity function |
1803 | /// Only examines closures and `std::convert::identity` | |
1804 | pub fn is_expr_identity_function(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { | |
1805 | /// Checks if a function's body represents the identity function. Looks for bodies of the form: | |
1806 | /// * `|x| x` | |
1807 | /// * `|x| return x` | |
1808 | /// * `|x| { return x }` | |
1809 | /// * `|x| { return x; }` | |
1810 | fn is_body_identity_function(cx: &LateContext<'_>, func: &Body<'_>) -> bool { | |
1811 | let id = if_chain! { | |
1812 | if let [param] = func.params; | |
1813 | if let PatKind::Binding(_, id, _, _) = param.pat.kind; | |
1814 | then { | |
1815 | id | |
1816 | } else { | |
1817 | return false; | |
1818 | } | |
1819 | }; | |
1820 | ||
1821 | let mut expr = &func.value; | |
1822 | loop { | |
1823 | match expr.kind { | |
1824 | #[rustfmt::skip] | |
1825 | ExprKind::Block(&Block { stmts: [], expr: Some(e), .. }, _, ) | |
1826 | | ExprKind::Ret(Some(e)) => expr = e, | |
1827 | #[rustfmt::skip] | |
1828 | ExprKind::Block(&Block { stmts: [stmt], expr: None, .. }, _) => { | |
1829 | if_chain! { | |
1830 | if let StmtKind::Semi(e) | StmtKind::Expr(e) = stmt.kind; | |
1831 | if let ExprKind::Ret(Some(ret_val)) = e.kind; | |
1832 | then { | |
1833 | expr = ret_val; | |
1834 | } else { | |
1835 | return false; | |
1836 | } | |
1837 | } | |
1838 | }, | |
1839 | _ => return path_to_local_id(expr, id) && cx.typeck_results().expr_adjustments(expr).is_empty(), | |
1840 | } | |
1841 | } | |
1842 | } | |
1843 | ||
1844 | match expr.kind { | |
1845 | ExprKind::Closure(_, _, body_id, _, _) => is_body_identity_function(cx, cx.tcx.hir().body(body_id)), | |
1846 | ExprKind::Path(ref path) => is_qpath_def_path(cx, path, expr.hir_id, &paths::CONVERT_IDENTITY), | |
1847 | _ => false, | |
1848 | } | |
1849 | } | |
1850 | ||
cdc7bbd5 XL |
1851 | /// Gets the node where an expression is either used, or it's type is unified with another branch. |
1852 | pub fn get_expr_use_or_unification_node(tcx: TyCtxt<'tcx>, expr: &Expr<'_>) -> Option<Node<'tcx>> { | |
cdc7bbd5 | 1853 | let mut child_id = expr.hir_id; |
c295e0f8 | 1854 | let mut iter = tcx.hir().parent_iter(child_id); |
cdc7bbd5 XL |
1855 | loop { |
1856 | match iter.next() { | |
1857 | None => break None, | |
1858 | Some((id, Node::Block(_))) => child_id = id, | |
1859 | Some((id, Node::Arm(arm))) if arm.body.hir_id == child_id => child_id = id, | |
1860 | Some((_, Node::Expr(expr))) => match expr.kind { | |
1861 | ExprKind::Match(_, [arm], _) if arm.hir_id == child_id => child_id = expr.hir_id, | |
1862 | ExprKind::Block(..) | ExprKind::DropTemps(_) => child_id = expr.hir_id, | |
1863 | ExprKind::If(_, then_expr, None) if then_expr.hir_id == child_id => break None, | |
1864 | _ => break Some(Node::Expr(expr)), | |
1865 | }, | |
1866 | Some((_, node)) => break Some(node), | |
1867 | } | |
1868 | } | |
1869 | } | |
1870 | ||
1871 | /// Checks if the result of an expression is used, or it's type is unified with another branch. | |
1872 | pub fn is_expr_used_or_unified(tcx: TyCtxt<'_>, expr: &Expr<'_>) -> bool { | |
1873 | !matches!( | |
1874 | get_expr_use_or_unification_node(tcx, expr), | |
1875 | None | Some(Node::Stmt(Stmt { | |
1876 | kind: StmtKind::Expr(_) | |
1877 | | StmtKind::Semi(_) | |
1878 | | StmtKind::Local(Local { | |
1879 | pat: Pat { | |
1880 | kind: PatKind::Wild, | |
1881 | .. | |
1882 | }, | |
1883 | .. | |
1884 | }), | |
1885 | .. | |
1886 | })) | |
1887 | ) | |
1888 | } | |
1889 | ||
1890 | /// Checks if the expression is the final expression returned from a block. | |
1891 | pub fn is_expr_final_block_expr(tcx: TyCtxt<'_>, expr: &Expr<'_>) -> bool { | |
1892 | matches!(get_parent_node(tcx, expr.hir_id), Some(Node::Block(..))) | |
1893 | } | |
1894 | ||
a2a8927a XL |
1895 | pub fn std_or_core(cx: &LateContext<'_>) -> Option<&'static str> { |
1896 | if !is_no_std_crate(cx) { | |
1897 | Some("std") | |
1898 | } else if !is_no_core_crate(cx) { | |
1899 | Some("core") | |
1900 | } else { | |
1901 | None | |
1902 | } | |
1903 | } | |
1904 | ||
f20569fa XL |
1905 | pub fn is_no_std_crate(cx: &LateContext<'_>) -> bool { |
1906 | cx.tcx.hir().attrs(hir::CRATE_HIR_ID).iter().any(|attr| { | |
1907 | if let ast::AttrKind::Normal(ref attr, _) = attr.kind { | |
1908 | attr.path == sym::no_std | |
1909 | } else { | |
1910 | false | |
1911 | } | |
1912 | }) | |
1913 | } | |
1914 | ||
a2a8927a XL |
1915 | pub fn is_no_core_crate(cx: &LateContext<'_>) -> bool { |
1916 | cx.tcx.hir().attrs(hir::CRATE_HIR_ID).iter().any(|attr| { | |
1917 | if let ast::AttrKind::Normal(ref attr, _) = attr.kind { | |
1918 | attr.path == sym::no_core | |
1919 | } else { | |
1920 | false | |
1921 | } | |
1922 | }) | |
1923 | } | |
1924 | ||
f20569fa XL |
1925 | /// Check if parent of a hir node is a trait implementation block. |
1926 | /// For example, `f` in | |
a2a8927a XL |
1927 | /// ```rust |
1928 | /// # struct S; | |
1929 | /// # trait Trait { fn f(); } | |
f20569fa XL |
1930 | /// impl Trait for S { |
1931 | /// fn f() {} | |
1932 | /// } | |
1933 | /// ``` | |
1934 | pub fn is_trait_impl_item(cx: &LateContext<'_>, hir_id: HirId) -> bool { | |
1935 | if let Some(Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_node(hir_id)) { | |
1936 | matches!(item.kind, ItemKind::Impl(hir::Impl { of_trait: Some(_), .. })) | |
1937 | } else { | |
1938 | false | |
1939 | } | |
1940 | } | |
1941 | ||
1942 | /// Check if it's even possible to satisfy the `where` clause for the item. | |
1943 | /// | |
1944 | /// `trivial_bounds` feature allows functions with unsatisfiable bounds, for example: | |
1945 | /// | |
1946 | /// ```ignore | |
1947 | /// fn foo() where i32: Iterator { | |
1948 | /// for _ in 2i32 {} | |
1949 | /// } | |
1950 | /// ``` | |
1951 | pub fn fn_has_unsatisfiable_preds(cx: &LateContext<'_>, did: DefId) -> bool { | |
1952 | use rustc_trait_selection::traits; | |
1953 | let predicates = cx | |
1954 | .tcx | |
1955 | .predicates_of(did) | |
1956 | .predicates | |
1957 | .iter() | |
94222f64 | 1958 | .filter_map(|(p, _)| if p.is_global(cx.tcx) { Some(*p) } else { None }); |
f20569fa XL |
1959 | traits::impossible_predicates( |
1960 | cx.tcx, | |
1961 | traits::elaborate_predicates(cx.tcx, predicates) | |
1962 | .map(|o| o.predicate) | |
1963 | .collect::<Vec<_>>(), | |
1964 | ) | |
1965 | } | |
1966 | ||
1967 | /// Returns the `DefId` of the callee if the given expression is a function or method call. | |
1968 | pub fn fn_def_id(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<DefId> { | |
1969 | match &expr.kind { | |
1970 | ExprKind::MethodCall(..) => cx.typeck_results().type_dependent_def_id(expr.hir_id), | |
1971 | ExprKind::Call( | |
1972 | Expr { | |
1973 | kind: ExprKind::Path(qpath), | |
1974 | hir_id: path_hir_id, | |
1975 | .. | |
1976 | }, | |
1977 | .., | |
1978 | ) => cx.typeck_results().qpath_res(qpath, *path_hir_id).opt_def_id(), | |
1979 | _ => None, | |
1980 | } | |
1981 | } | |
1982 | ||
f20569fa XL |
1983 | /// Returns Option<String> where String is a textual representation of the type encapsulated in the |
1984 | /// slice iff the given expression is a slice of primitives (as defined in the | |
1985 | /// `is_recursively_primitive_type` function) and None otherwise. | |
1986 | pub fn is_slice_of_primitives(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<String> { | |
1987 | let expr_type = cx.typeck_results().expr_ty_adjusted(expr); | |
1988 | let expr_kind = expr_type.kind(); | |
1989 | let is_primitive = match expr_kind { | |
cdc7bbd5 XL |
1990 | rustc_ty::Slice(element_type) => is_recursively_primitive_type(element_type), |
1991 | rustc_ty::Ref(_, inner_ty, _) if matches!(inner_ty.kind(), &rustc_ty::Slice(_)) => { | |
1992 | if let rustc_ty::Slice(element_type) = inner_ty.kind() { | |
f20569fa XL |
1993 | is_recursively_primitive_type(element_type) |
1994 | } else { | |
1995 | unreachable!() | |
1996 | } | |
1997 | }, | |
1998 | _ => false, | |
1999 | }; | |
2000 | ||
2001 | if is_primitive { | |
2002 | // if we have wrappers like Array, Slice or Tuple, print these | |
2003 | // and get the type enclosed in the slice ref | |
94222f64 | 2004 | match expr_type.peel_refs().walk(cx.tcx).nth(1).unwrap().expect_ty().kind() { |
cdc7bbd5 XL |
2005 | rustc_ty::Slice(..) => return Some("slice".into()), |
2006 | rustc_ty::Array(..) => return Some("array".into()), | |
2007 | rustc_ty::Tuple(..) => return Some("tuple".into()), | |
f20569fa XL |
2008 | _ => { |
2009 | // is_recursively_primitive_type() should have taken care | |
2010 | // of the rest and we can rely on the type that is found | |
2011 | let refs_peeled = expr_type.peel_refs(); | |
94222f64 | 2012 | return Some(refs_peeled.walk(cx.tcx).last().unwrap().to_string()); |
f20569fa XL |
2013 | }, |
2014 | } | |
2015 | } | |
2016 | None | |
2017 | } | |
2018 | ||
2019 | /// returns list of all pairs (a, b) from `exprs` such that `eq(a, b)` | |
2020 | /// `hash` must be comformed with `eq` | |
2021 | pub fn search_same<T, Hash, Eq>(exprs: &[T], hash: Hash, eq: Eq) -> Vec<(&T, &T)> | |
2022 | where | |
2023 | Hash: Fn(&T) -> u64, | |
2024 | Eq: Fn(&T, &T) -> bool, | |
2025 | { | |
17df50a5 XL |
2026 | match exprs { |
2027 | [a, b] if eq(a, b) => return vec![(a, b)], | |
2028 | _ if exprs.len() <= 2 => return vec![], | |
2029 | _ => {}, | |
f20569fa XL |
2030 | } |
2031 | ||
2032 | let mut match_expr_list: Vec<(&T, &T)> = Vec::new(); | |
2033 | ||
17df50a5 XL |
2034 | let mut map: UnhashMap<u64, Vec<&_>> = |
2035 | UnhashMap::with_capacity_and_hasher(exprs.len(), BuildHasherDefault::default()); | |
f20569fa XL |
2036 | |
2037 | for expr in exprs { | |
2038 | match map.entry(hash(expr)) { | |
2039 | Entry::Occupied(mut o) => { | |
2040 | for o in o.get() { | |
2041 | if eq(o, expr) { | |
2042 | match_expr_list.push((o, expr)); | |
2043 | } | |
2044 | } | |
2045 | o.get_mut().push(expr); | |
2046 | }, | |
2047 | Entry::Vacant(v) => { | |
2048 | v.insert(vec![expr]); | |
2049 | }, | |
2050 | } | |
2051 | } | |
2052 | ||
2053 | match_expr_list | |
2054 | } | |
2055 | ||
2056 | /// Peels off all references on the pattern. Returns the underlying pattern and the number of | |
2057 | /// references removed. | |
2058 | pub fn peel_hir_pat_refs(pat: &'a Pat<'a>) -> (&'a Pat<'a>, usize) { | |
2059 | fn peel(pat: &'a Pat<'a>, count: usize) -> (&'a Pat<'a>, usize) { | |
2060 | if let PatKind::Ref(pat, _) = pat.kind { | |
2061 | peel(pat, count + 1) | |
2062 | } else { | |
2063 | (pat, count) | |
2064 | } | |
2065 | } | |
2066 | peel(pat, 0) | |
2067 | } | |
2068 | ||
cdc7bbd5 XL |
2069 | /// Peels of expressions while the given closure returns `Some`. |
2070 | pub fn peel_hir_expr_while<'tcx>( | |
2071 | mut expr: &'tcx Expr<'tcx>, | |
2072 | mut f: impl FnMut(&'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>>, | |
2073 | ) -> &'tcx Expr<'tcx> { | |
2074 | while let Some(e) = f(expr) { | |
2075 | expr = e; | |
2076 | } | |
2077 | expr | |
2078 | } | |
2079 | ||
f20569fa XL |
2080 | /// Peels off up to the given number of references on the expression. Returns the underlying |
2081 | /// expression and the number of references removed. | |
2082 | pub fn peel_n_hir_expr_refs(expr: &'a Expr<'a>, count: usize) -> (&'a Expr<'a>, usize) { | |
cdc7bbd5 XL |
2083 | let mut remaining = count; |
2084 | let e = peel_hir_expr_while(expr, |e| match e.kind { | |
c295e0f8 | 2085 | ExprKind::AddrOf(ast::BorrowKind::Ref, _, e) if remaining != 0 => { |
cdc7bbd5 XL |
2086 | remaining -= 1; |
2087 | Some(e) | |
2088 | }, | |
2089 | _ => None, | |
2090 | }); | |
2091 | (e, count - remaining) | |
f20569fa XL |
2092 | } |
2093 | ||
2094 | /// Peels off all references on the expression. Returns the underlying expression and the number of | |
2095 | /// references removed. | |
2096 | pub fn peel_hir_expr_refs(expr: &'a Expr<'a>) -> (&'a Expr<'a>, usize) { | |
cdc7bbd5 XL |
2097 | let mut count = 0; |
2098 | let e = peel_hir_expr_while(expr, |e| match e.kind { | |
c295e0f8 | 2099 | ExprKind::AddrOf(ast::BorrowKind::Ref, _, e) => { |
cdc7bbd5 XL |
2100 | count += 1; |
2101 | Some(e) | |
2102 | }, | |
2103 | _ => None, | |
2104 | }); | |
2105 | (e, count) | |
f20569fa XL |
2106 | } |
2107 | ||
136023e0 XL |
2108 | /// Removes `AddrOf` operators (`&`) or deref operators (`*`), but only if a reference type is |
2109 | /// dereferenced. An overloaded deref such as `Vec` to slice would not be removed. | |
2110 | pub fn peel_ref_operators<'hir>(cx: &LateContext<'_>, mut expr: &'hir Expr<'hir>) -> &'hir Expr<'hir> { | |
2111 | loop { | |
2112 | match expr.kind { | |
2113 | ExprKind::AddrOf(_, _, e) => expr = e, | |
2114 | ExprKind::Unary(UnOp::Deref, e) if cx.typeck_results().expr_ty(e).is_ref() => expr = e, | |
2115 | _ => break, | |
2116 | } | |
2117 | } | |
2118 | expr | |
2119 | } | |
2120 | ||
f20569fa XL |
2121 | #[macro_export] |
2122 | macro_rules! unwrap_cargo_metadata { | |
2123 | ($cx: ident, $lint: ident, $deps: expr) => {{ | |
2124 | let mut command = cargo_metadata::MetadataCommand::new(); | |
2125 | if !$deps { | |
2126 | command.no_deps(); | |
2127 | } | |
2128 | ||
2129 | match command.exec() { | |
2130 | Ok(metadata) => metadata, | |
2131 | Err(err) => { | |
2132 | span_lint($cx, $lint, DUMMY_SP, &format!("could not read cargo metadata: {}", err)); | |
2133 | return; | |
2134 | }, | |
2135 | } | |
2136 | }}; | |
2137 | } | |
2138 | ||
2139 | pub fn is_hir_ty_cfg_dependant(cx: &LateContext<'_>, ty: &hir::Ty<'_>) -> bool { | |
3c0e092e XL |
2140 | if let TyKind::Path(QPath::Resolved(_, path)) = ty.kind { |
2141 | if let Res::Def(_, def_id) = path.res { | |
2142 | return cx.tcx.has_attr(def_id, sym::cfg) || cx.tcx.has_attr(def_id, sym::cfg_attr); | |
f20569fa XL |
2143 | } |
2144 | } | |
3c0e092e | 2145 | false |
f20569fa | 2146 | } |
136023e0 | 2147 | |
a2a8927a | 2148 | struct TestItemNamesVisitor<'tcx> { |
3c0e092e XL |
2149 | tcx: TyCtxt<'tcx>, |
2150 | names: Vec<Symbol>, | |
3c0e092e | 2151 | } |
a2a8927a XL |
2152 | |
2153 | impl<'hir> ItemLikeVisitor<'hir> for TestItemNamesVisitor<'hir> { | |
3c0e092e XL |
2154 | fn visit_item(&mut self, item: &Item<'_>) { |
2155 | if let ItemKind::Const(ty, _body) = item.kind { | |
2156 | if let TyKind::Path(QPath::Resolved(_, path)) = ty.kind { | |
2157 | // We could also check for the type name `test::TestDescAndFn` | |
3c0e092e XL |
2158 | if let Res::Def(DefKind::Struct, _) = path.res { |
2159 | let has_test_marker = self | |
2160 | .tcx | |
2161 | .hir() | |
2162 | .attrs(item.hir_id()) | |
2163 | .iter() | |
2164 | .any(|a| a.has_name(sym::rustc_test_marker)); | |
a2a8927a XL |
2165 | if has_test_marker { |
2166 | self.names.push(item.ident.name); | |
3c0e092e XL |
2167 | } |
2168 | } | |
2169 | } | |
136023e0 XL |
2170 | } |
2171 | } | |
3c0e092e XL |
2172 | fn visit_trait_item(&mut self, _: &TraitItem<'_>) {} |
2173 | fn visit_impl_item(&mut self, _: &ImplItem<'_>) {} | |
2174 | fn visit_foreign_item(&mut self, _: &ForeignItem<'_>) {} | |
2175 | } | |
136023e0 | 2176 | |
a2a8927a XL |
2177 | static TEST_ITEM_NAMES_CACHE: SyncOnceCell<Mutex<FxHashMap<LocalDefId, Vec<Symbol>>>> = SyncOnceCell::new(); |
2178 | ||
2179 | fn with_test_item_names(tcx: TyCtxt<'tcx>, module: LocalDefId, f: impl Fn(&[Symbol]) -> bool) -> bool { | |
2180 | let cache = TEST_ITEM_NAMES_CACHE.get_or_init(|| Mutex::new(FxHashMap::default())); | |
2181 | let mut map: MutexGuard<'_, FxHashMap<LocalDefId, Vec<Symbol>>> = cache.lock().unwrap(); | |
2182 | match map.entry(module) { | |
2183 | Entry::Occupied(entry) => f(entry.get()), | |
2184 | Entry::Vacant(entry) => { | |
2185 | let mut visitor = TestItemNamesVisitor { tcx, names: Vec::new() }; | |
2186 | tcx.hir().visit_item_likes_in_module(module, &mut visitor); | |
2187 | visitor.names.sort_unstable(); | |
2188 | f(&*entry.insert(visitor.names)) | |
2189 | }, | |
2190 | } | |
2191 | } | |
2192 | ||
3c0e092e XL |
2193 | /// Checks if the function containing the given `HirId` is a `#[test]` function |
2194 | /// | |
2195 | /// Note: If you use this function, please add a `#[test]` case in `tests/ui_test`. | |
2196 | pub fn is_in_test_function(tcx: TyCtxt<'_>, id: hir::HirId) -> bool { | |
a2a8927a XL |
2197 | with_test_item_names(tcx, tcx.parent_module(id), |names| { |
2198 | tcx.hir() | |
2199 | .parent_iter(id) | |
2200 | // Since you can nest functions we need to collect all until we leave | |
2201 | // function scope | |
2202 | .any(|(_id, node)| { | |
2203 | if let Node::Item(item) = node { | |
2204 | if let ItemKind::Fn(_, _, _) = item.kind { | |
2205 | // Note that we have sorted the item names in the visitor, | |
2206 | // so the binary_search gets the same as `contains`, but faster. | |
2207 | return names.binary_search(&item.ident.name).is_ok(); | |
2208 | } | |
3c0e092e | 2209 | } |
a2a8927a XL |
2210 | false |
2211 | }) | |
2212 | }) | |
3c0e092e XL |
2213 | } |
2214 | ||
2215 | /// Checks whether item either has `test` attribute applied, or | |
2216 | /// is a module with `test` in its name. | |
2217 | /// | |
2218 | /// Note: If you use this function, please add a `#[test]` case in `tests/ui_test`. | |
2219 | pub fn is_test_module_or_function(tcx: TyCtxt<'_>, item: &Item<'_>) -> bool { | |
2220 | is_in_test_function(tcx, item.hir_id()) | |
2221 | || matches!(item.kind, ItemKind::Mod(..)) | |
2222 | && item.ident.name.as_str().split('_').any(|a| a == "test" || a == "tests") | |
136023e0 XL |
2223 | } |
2224 | ||
2225 | macro_rules! op_utils { | |
2226 | ($($name:ident $assign:ident)*) => { | |
2227 | /// Binary operation traits like `LangItem::Add` | |
2228 | pub static BINOP_TRAITS: &[LangItem] = &[$(LangItem::$name,)*]; | |
2229 | ||
2230 | /// Operator-Assign traits like `LangItem::AddAssign` | |
2231 | pub static OP_ASSIGN_TRAITS: &[LangItem] = &[$(LangItem::$assign,)*]; | |
2232 | ||
2233 | /// Converts `BinOpKind::Add` to `(LangItem::Add, LangItem::AddAssign)`, for example | |
2234 | pub fn binop_traits(kind: hir::BinOpKind) -> Option<(LangItem, LangItem)> { | |
2235 | match kind { | |
2236 | $(hir::BinOpKind::$name => Some((LangItem::$name, LangItem::$assign)),)* | |
2237 | _ => None, | |
2238 | } | |
2239 | } | |
2240 | }; | |
2241 | } | |
2242 | ||
2243 | op_utils! { | |
2244 | Add AddAssign | |
2245 | Sub SubAssign | |
2246 | Mul MulAssign | |
2247 | Div DivAssign | |
2248 | Rem RemAssign | |
2249 | BitXor BitXorAssign | |
2250 | BitAnd BitAndAssign | |
2251 | BitOr BitOrAssign | |
2252 | Shl ShlAssign | |
2253 | Shr ShrAssign | |
2254 | } |