From d687d46f68295c5e8aa318492500d22450d89b20 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Thu, 3 Nov 2022 13:51:44 -0700
Subject: [PATCH] Tweak output in for loops
Do not suggest `.clone()` as we already suggest borrowing the iterated
value.
---
.../src/diagnostics/conflict_errors.rs | 14 +++++++++++---
src/test/ui/issues/issue-61108.stderr | 4 ----
src/test/ui/issues/issue-64559.stderr | 4 ----
src/test/ui/moves/move-fn-self-receiver.stderr | 4 ----
.../ui/suggestions/borrow-for-loop-head.stderr | 4 ----
5 files changed, 11 insertions(+), 19 deletions(-)
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 18d8bbf9047..e917d527eb3 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -397,8 +397,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
&& let Some(node) = hir.find(hir.local_def_id_to_hir_id(def_id))
&& let Some(fn_sig) = node.fn_sig()
&& let Some(ident) = node.ident()
- && let Some(pos) = args.iter()
- .position(|arg| arg.hir_id == expr.hir_id)
+ && let Some(pos) = args.iter().position(|arg| arg.hir_id == expr.hir_id)
&& let Some(arg) = fn_sig.decl.inputs.get(pos + offset)
{
let mut span: MultiSpan = arg.span.into();
@@ -425,7 +424,16 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
}
let place = &self.move_data.move_paths[mpi].place;
let ty = place.ty(self.body, self.infcx.tcx).ty;
- self.suggest_cloning(err, ty, move_span);
+ if let hir::Node::Expr(parent_expr) = parent
+ && let hir::ExprKind::Call(call_expr, _) = parent_expr.kind
+ && let hir::ExprKind::Path(
+ hir::QPath::LangItem(LangItem::IntoIterIntoIter, _, _)
+ ) = call_expr.kind
+ {
+ // Do not suggest `.clone()` in a `for` loop, we already suggest borrowing.
+ } else {
+ self.suggest_cloning(err, ty, move_span);
+ }
}
}
if let Some(pat) = finder.pat && !seen_spans.contains(&pat.span) {
diff --git a/src/test/ui/issues/issue-61108.stderr b/src/test/ui/issues/issue-61108.stderr
index 0f6f30531b3..e5b671d7b7a 100644
--- a/src/test/ui/issues/issue-61108.stderr
+++ b/src/test/ui/issues/issue-61108.stderr
@@ -14,10 +14,6 @@ note: this function takes ownership of the receiver `self`, which moves `bad_let
|
LL | fn into_iter(self) -> Self::IntoIter;
| ^^^^
-help: consider cloning the value if the performance cost is acceptable
- |
-LL | for l in bad_letters.clone() {
- | ++++++++
help: consider iterating over a slice of the `Vec<char>`'s content to avoid moving into the `for` loop
|
LL | for l in &bad_letters {
diff --git a/src/test/ui/issues/issue-64559.stderr b/src/test/ui/issues/issue-64559.stderr
index 5c04cefa530..ef178bbd155 100644
--- a/src/test/ui/issues/issue-64559.stderr
+++ b/src/test/ui/issues/issue-64559.stderr
@@ -15,10 +15,6 @@ note: this function takes ownership of the receiver `self`, which moves `orig`
|
LL | fn into_iter(self) -> Self::IntoIter;
| ^^^^
-help: consider cloning the value if the performance cost is acceptable
- |
-LL | for _val in orig.clone() {}
- | ++++++++
help: consider iterating over a slice of the `Vec<bool>`'s content to avoid moving into the `for` loop
|
LL | for _val in &orig {}
diff --git a/src/test/ui/moves/move-fn-self-receiver.stderr b/src/test/ui/moves/move-fn-self-receiver.stderr
index b331b10a3b7..c13dc58826e 100644
--- a/src/test/ui/moves/move-fn-self-receiver.stderr
+++ b/src/test/ui/moves/move-fn-self-receiver.stderr
@@ -127,10 +127,6 @@ LL | for _val in implicit_into_iter {}
LL | implicit_into_iter;
| ^^^^^^^^^^^^^^^^^^ value used here after move
|
-help: consider cloning the value if the performance cost is acceptable
- |
-LL | for _val in implicit_into_iter.clone() {}
- | ++++++++
help: consider iterating over a slice of the `Vec<bool>`'s content to avoid moving into the `for` loop
|
LL | for _val in &implicit_into_iter {}
diff --git a/src/test/ui/suggestions/borrow-for-loop-head.stderr b/src/test/ui/suggestions/borrow-for-loop-head.stderr
index 7cd411dde6c..0cc8994fe1f 100644
--- a/src/test/ui/suggestions/borrow-for-loop-head.stderr
+++ b/src/test/ui/suggestions/borrow-for-loop-head.stderr
@@ -21,10 +21,6 @@ note: this function takes ownership of the receiver `self`, which moves `a`
|
LL | fn into_iter(self) -> Self::IntoIter;
| ^^^^
-help: consider cloning the value if the performance cost is acceptable
- |
-LL | for j in a.clone() {
- | ++++++++
help: consider iterating over a slice of the `Vec<i32>`'s content to avoid moving into the `for` loop
|
LL | for j in &a {