X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;ds=sidebyside;f=clippy_lints%2Fsrc%2Fmethods%2Fsearch_is_some.rs;h=5ed4ba94884e26b627874b7253608150eca9a0a9;hb=3c8f90bd5a03872a9b9088facc3bf9ec8ac42dd0;hp=d08abc5b3defbb0668a35c1898155dada01a8982;hpb=abaaf744fdbe8106bc82ceaa34e8499d5436fc3c;p=rust.git diff --git a/clippy_lints/src/methods/search_is_some.rs b/clippy_lints/src/methods/search_is_some.rs index d08abc5b3de..5ed4ba94884 100644 --- a/clippy_lints/src/methods/search_is_some.rs +++ b/clippy_lints/src/methods/search_is_some.rs @@ -1,21 +1,16 @@ -use std::iter; - use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg}; use clippy_utils::source::{snippet, snippet_with_applicability}; +use clippy_utils::sugg::deref_closure_args; use clippy_utils::ty::is_type_diagnostic_item; -use clippy_utils::{get_parent_expr_for_hir, is_trait_method, strip_pat_refs}; +use clippy_utils::{is_trait_method, strip_pat_refs}; use if_chain::if_chain; use rustc_errors::Applicability; use rustc_hir as hir; -use rustc_hir::{self, ExprKind, HirId, PatKind}; -use rustc_infer::infer::TyCtxtInferExt; +use rustc_hir::PatKind; use rustc_lint::LateContext; -use rustc_middle::hir::place::ProjectionKind; -use rustc_middle::mir::{FakeReadCause, Mutability}; use rustc_middle::ty; -use rustc_span::source_map::{BytePos, Span}; +use rustc_span::source_map::Span; use rustc_span::symbol::sym; -use rustc_typeck::expr_use_visitor::{Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId}; use super::SEARCH_IS_SOME; @@ -52,26 +47,12 @@ pub(super) fn check<'tcx>( then { if let hir::PatKind::Ref(..) = closure_arg.pat.kind { Some(search_snippet.replacen('&', "", 1)) - } else if let PatKind::Binding(_, binding_id, _, _) = strip_pat_refs(closure_arg.pat).kind { - // this binding is composed of at least two levels of references, so we need to remove one - let binding_type = cx.typeck_results().node_type(binding_id); - let innermost_is_ref = if let ty::Ref(_, inner,_) = binding_type.kind() { - matches!(inner.kind(), ty::Ref(_, innermost, _) if innermost.is_ref()) - } else { - false - }; - + } else if let PatKind::Binding(..) = strip_pat_refs(closure_arg.pat).kind { // `find()` provides a reference to the item, but `any` does not, // so we should fix item usages for suggestion - if let Some(closure_sugg) = get_closure_suggestion(cx, search_arg, closure_body) { + if let Some(closure_sugg) = deref_closure_args(cx, search_arg) { applicability = closure_sugg.applicability; - if innermost_is_ref { - Some(closure_sugg.suggestion.replacen('&', "", 1)) - } else { - Some(closure_sugg.suggestion) - } - } else if innermost_is_ref { - Some(search_snippet.replacen('&', "", 1)) + Some(closure_sugg.suggestion) } else { Some(search_snippet.to_string()) } @@ -173,204 +154,3 @@ pub(super) fn check<'tcx>( } } } - -struct ClosureSugg { - applicability: Applicability, - suggestion: String, -} - -// Build suggestion gradually by handling closure arg specific usages, -// such as explicit deref and borrowing cases. -// Returns `None` if no such use cases have been triggered in closure body -fn get_closure_suggestion<'tcx>( - cx: &LateContext<'_>, - search_arg: &'tcx hir::Expr<'_>, - closure_body: &hir::Body<'_>, -) -> Option { - let mut visitor = DerefDelegate { - cx, - closure_span: search_arg.span, - next_pos: search_arg.span.lo(), - suggestion_start: String::new(), - applicability: Applicability::MachineApplicable, - }; - - let fn_def_id = cx.tcx.hir().local_def_id(search_arg.hir_id); - cx.tcx.infer_ctxt().enter(|infcx| { - ExprUseVisitor::new(&mut visitor, &infcx, fn_def_id, cx.param_env, cx.typeck_results()) - .consume_body(closure_body); - }); - - if visitor.suggestion_start.is_empty() { - None - } else { - Some(ClosureSugg { - applicability: visitor.applicability, - suggestion: visitor.finish(), - }) - } -} - -struct DerefDelegate<'a, 'tcx> { - cx: &'a LateContext<'tcx>, - closure_span: Span, - next_pos: BytePos, - suggestion_start: String, - applicability: Applicability, -} - -impl DerefDelegate<'_, 'tcx> { - pub fn finish(&mut self) -> String { - let end_span = Span::new(self.next_pos, self.closure_span.hi(), self.closure_span.ctxt(), None); - let end_snip = snippet_with_applicability(self.cx, end_span, "..", &mut self.applicability); - format!("{}{}", self.suggestion_start, end_snip) - } - - fn func_takes_arg_by_ref(&self, parent_expr: &'tcx hir::Expr<'_>, cmt_hir_id: HirId) -> bool { - let (call_args, inputs) = match parent_expr.kind { - ExprKind::MethodCall(_, _, call_args, _) => { - if let Some(method_did) = self.cx.typeck_results().type_dependent_def_id(parent_expr.hir_id) { - (call_args, self.cx.tcx.fn_sig(method_did).skip_binder().inputs()) - } else { - return false; - } - }, - ExprKind::Call(func, call_args) => { - let typ = self.cx.typeck_results().expr_ty(func); - (call_args, typ.fn_sig(self.cx.tcx).skip_binder().inputs()) - }, - _ => return false, - }; - - iter::zip(call_args, inputs) - .any(|(arg, ty)| arg.hir_id == cmt_hir_id && matches!(ty.kind(), ty::Ref(_, inner, _) if inner.is_ref())) - } -} - -impl<'tcx> Delegate<'tcx> for DerefDelegate<'_, 'tcx> { - fn consume(&mut self, _: &PlaceWithHirId<'tcx>, _: HirId) {} - - fn borrow(&mut self, cmt: &PlaceWithHirId<'tcx>, _: HirId, _: ty::BorrowKind) { - if let PlaceBase::Local(id) = cmt.place.base { - let map = self.cx.tcx.hir(); - let ident_str = map.name(id).to_string(); - let span = map.span(cmt.hir_id); - let start_span = Span::new(self.next_pos, span.lo(), span.ctxt(), None); - let mut start_snip = snippet_with_applicability(self.cx, start_span, "..", &mut self.applicability); - - if cmt.place.projections.is_empty() { - // handle item without any projection, that needs an explicit borrowing - // i.e.: suggest `&x` instead of `x` - self.suggestion_start.push_str(&format!("{}&{}", start_snip, ident_str)); - } else { - // cases where a parent `Call` or `MethodCall` is using the item - // i.e.: suggest `.contains(&x)` for `.find(|x| [1, 2, 3].contains(x)).is_none()` - // - // Note about method calls: - // - compiler automatically dereference references if the target type is a reference (works also for - // function call) - // - `self` arguments in the case of `x.is_something()` are also automatically (de)referenced, and - // no projection should be suggested - if let Some(parent_expr) = get_parent_expr_for_hir(self.cx, cmt.hir_id) { - if let ExprKind::Call(_, call_args) | ExprKind::MethodCall(_, _, call_args, _) = parent_expr.kind { - let expr = self.cx.tcx.hir().expect_expr(cmt.hir_id); - let arg_ty_kind = self.cx.typeck_results().expr_ty(expr).kind(); - - if matches!(arg_ty_kind, ty::Ref(_, _, Mutability::Not)) { - // suggest ampersand if call function is taking args by ref - let takes_arg_by_ref = self.func_takes_arg_by_ref(parent_expr, cmt.hir_id); - - // do not suggest ampersand if the ident is the method caller - let ident_sugg = - if !call_args.is_empty() && call_args[0].hir_id == cmt.hir_id && !takes_arg_by_ref { - format!("{}{}", start_snip, ident_str) - } else { - format!("{}&{}", start_snip, ident_str) - }; - self.suggestion_start.push_str(&ident_sugg); - self.next_pos = span.hi(); - return; - } - - self.applicability = Applicability::Unspecified; - } - } - - let mut replacement_str = ident_str; - let mut projections_handled = false; - cmt.place.projections.iter().enumerate().for_each(|(i, proj)| { - match proj.kind { - // Field projection like `|v| v.foo` - // no adjustment needed here, as field projections are handled by the compiler - ProjectionKind::Field(idx, variant) => match cmt.place.ty_before_projection(i).kind() { - ty::Adt(def, ..) => { - replacement_str = format!( - "{}.{}", - replacement_str, - def.variants[variant].fields[idx as usize].ident.name.as_str() - ); - projections_handled = true; - }, - ty::Tuple(_) => { - replacement_str = format!("{}.{}", replacement_str, idx); - projections_handled = true; - }, - _ => (), - }, - // Index projection like `|x| foo[x]` - // the index is dropped so we can't get it to build the suggestion, - // so the span is set-up again to get more code, using `span.hi()` (i.e.: `foo[x]`) - // instead of `span.lo()` (i.e.: `foo`) - ProjectionKind::Index => { - let start_span = Span::new(self.next_pos, span.hi(), span.ctxt(), None); - start_snip = snippet_with_applicability(self.cx, start_span, "..", &mut self.applicability); - replacement_str.clear(); - projections_handled = true; - }, - // note: unable to trigger `Subslice` kind in tests - ProjectionKind::Subslice => (), - ProjectionKind::Deref => { - // explicit deref for arrays should be avoided in the suggestion - // i.e.: `|sub| *sub[1..4].len() == 3` is not expected - if let ty::Ref(_, inner, _) = cmt.place.ty_before_projection(i).kind() { - // dereferencing an array (i.e.: `|sub| sub[1..4].len() == 3`) - if matches!(inner.kind(), ty::Ref(_, innermost, _) if innermost.is_array()) { - projections_handled = true; - } - } - }, - } - }); - - // handle `ProjectionKind::Deref` by removing one explicit deref - // if no special case was detected (i.e.: suggest `*x` instead of `**x`) - if !projections_handled { - let last_deref = cmt - .place - .projections - .iter() - .rposition(|proj| proj.kind == ProjectionKind::Deref); - - if let Some(pos) = last_deref { - let mut projections = cmt.place.projections.clone(); - projections.truncate(pos); - - for item in projections { - if item.kind == ProjectionKind::Deref { - replacement_str = format!("*{}", replacement_str); - } - } - } - } - - self.suggestion_start - .push_str(&format!("{}{}", start_snip, replacement_str)); - } - self.next_pos = span.hi(); - } - } - - fn mutate(&mut self, _: &PlaceWithHirId<'tcx>, _: HirId) {} - - fn fake_read(&mut self, _: rustc_typeck::expr_use_visitor::Place<'tcx>, _: FakeReadCause, _: HirId) {} -}