use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg};
use clippy_utils::source::{snippet, snippet_with_applicability};
use clippy_utils::ty::is_type_diagnostic_item;
-use clippy_utils::{is_trait_method, strip_pat_refs};
+use clippy_utils::{get_parent_expr_for_hir, is_trait_method, strip_pat_refs};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir as hir;
-use rustc_hir::PatKind;
+use rustc_hir::{self, ExprKind, HirId, PatKind};
+use rustc_infer::infer::TyCtxtInferExt;
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::Span;
+use rustc_span::source_map::{BytePos, Span};
use rustc_span::symbol::sym;
+use rustc_typeck::expr_use_visitor::{Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId};
use super::SEARCH_IS_SOME;
if search_snippet.lines().count() <= 1 {
// suggest `any(|x| ..)` instead of `any(|&x| ..)` for `find(|&x| ..).is_some()`
// suggest `any(|..| *..)` instead of `any(|..| **..)` for `find(|..| **..).is_some()`
+ let mut applicability = Applicability::MachineApplicable;
let any_search_snippet = if_chain! {
if search_method == "find";
if let hir::ExprKind::Closure(_, _, body_id, ..) = search_arg.kind;
then {
if let hir::PatKind::Ref(..) = closure_arg.pat.kind {
Some(search_snippet.replacen('&', "", 1))
- } else if let PatKind::Binding(_, _, ident, _) = strip_pat_refs(closure_arg.pat).kind {
- let name = &*ident.name.as_str();
- Some(search_snippet.replace(&format!("*{}", name), name))
+ } 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
+ };
+
+ // `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) {
+ 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))
+ } else {
+ Some(search_snippet.to_string())
+ }
} else {
None
}
"any({})",
any_search_snippet.as_ref().map_or(&*search_snippet, String::as_str)
),
- Applicability::MachineApplicable,
+ applicability,
);
} else {
let iter = snippet(cx, search_recv.span, "..");
iter,
any_search_snippet.as_ref().map_or(&*search_snippet, String::as_str)
),
- Applicability::MachineApplicable,
+ applicability,
);
}
} else {
}
}
}
+
+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<ClosureSugg> {
+ 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());
+ let end_snip = snippet_with_applicability(self.cx, end_span, "..", &mut self.applicability);
+ format!("{}{}", self.suggestion_start, end_snip)
+ }
+}
+
+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());
+ 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 is using the item
+ // i.e.: suggest `.contains(&x)` for `.find(|x| [1, 2, 3].contains(x)).is_none()`
+ 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)) {
+ let start_span = Span::new(self.next_pos, span.lo(), span.ctxt());
+ let start_snip =
+ snippet_with_applicability(self.cx, start_span, "..", &mut self.applicability);
+ // 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 {
+ format!("{}{}", start_snip, ident_str)
+ } else {
+ format!("{}&{}", start_snip, ident_str)
+ };
+ self.suggestion_start.push_str(&ident_sugg);
+ self.next_pos = span.hi();
+ return;
+ } else {
+ self.applicability = Applicability::Unspecified;
+ }
+ }
+ }
+
+ // handle item projections by removing one explicit deref
+ // i.e.: suggest `*x` instead of `**x`
+ let mut replacement_str = ident_str;
+
+ // handle index projection first
+ let index_handled = cmt.place.projections.iter().any(|proj| match proj.kind {
+ // 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());
+ start_snip = snippet_with_applicability(self.cx, start_span, "..", &mut self.applicability);
+ replacement_str.clear();
+ true
+ },
+ _ => false,
+ });
+
+ // looking for projections other that need to be handled differently
+ let other_projections_handled = cmt.place.projections.iter().enumerate().any(|(i, proj)| {
+ match proj.kind {
+ // Field projection like `|v| v.foo`
+ 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()
+ );
+ true
+ },
+ ty::Tuple(_) => {
+ replacement_str = format!("{}.{}", replacement_str, idx);
+ true
+ },
+ _ => false,
+ },
+ // handled previously
+ ProjectionKind::Index |
+ // note: unable to trigger `Subslice` kind in tests
+ ProjectionKind::Subslice => false,
+ ProjectionKind::Deref => {
+ // explicit deref for arrays should be avoided in the suggestion
+ // i.e.: `|sub| *sub[1..4].len() == 3` is not expected
+ match cmt.place.ty_before_projection(i).kind() {
+ // dereferencing an array (i.e.: `|sub| sub[1..4].len() == 3`)
+ ty::Ref(_, inner, _) => {
+ matches!(inner.kind(), ty::Ref(_, innermost, _) if innermost.is_array())
+ },
+ _ => false,
+ }
+ },
+ }
+ });
+
+ // handle `ProjectionKind::Deref` if no special case detected
+ if !index_handled && !other_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) {}
+}
projects / rust.git / blobdiff