From c39849a34dae51d104f197894ed5a9f02dd62d75 Mon Sep 17 00:00:00 2001
From: feniljain <fkjainco@gmail.com>
Date: Sat, 17 Dec 2022 17:24:03 +0530
Subject: [PATCH] fix: not suggest seek_to_start_instead_of_rewind when expr is
used
---
clippy_lints/src/methods/seek_to_start_instead_of_rewind.rs | 6 +++++-
tests/ui/seek_to_start_instead_of_rewind.fixed | 6 ++++++
tests/ui/seek_to_start_instead_of_rewind.rs | 6 ++++++
tests/ui/seek_to_start_instead_of_rewind.stderr | 2 +-
4 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/clippy_lints/src/methods/seek_to_start_instead_of_rewind.rs b/clippy_lints/src/methods/seek_to_start_instead_of_rewind.rs
index 7e3bed1e41a..660b7049cce 100644
--- a/clippy_lints/src/methods/seek_to_start_instead_of_rewind.rs
+++ b/clippy_lints/src/methods/seek_to_start_instead_of_rewind.rs
@@ -1,6 +1,6 @@
use clippy_utils::diagnostics::span_lint_and_then;
use clippy_utils::ty::implements_trait;
-use clippy_utils::{get_trait_def_id, match_def_path, paths};
+use clippy_utils::{get_trait_def_id, is_expr_used_or_unified, match_def_path, paths};
use rustc_ast::ast::{LitIntType, LitKind};
use rustc_errors::Applicability;
use rustc_hir::{Expr, ExprKind};
@@ -19,6 +19,10 @@ pub(super) fn check<'tcx>(
// Get receiver type
let ty = cx.typeck_results().expr_ty(recv).peel_refs();
+ if is_expr_used_or_unified(cx.tcx, expr) {
+ return;
+ }
+
if let Some(seek_trait_id) = get_trait_def_id(cx, &paths::STD_IO_SEEK) &&
implements_trait(cx, ty, seek_trait_id, &[]) &&
let ExprKind::Call(func, args1) = arg.kind &&
diff --git a/tests/ui/seek_to_start_instead_of_rewind.fixed b/tests/ui/seek_to_start_instead_of_rewind.fixed
index 9d0d1124c46..713cff604a1 100644
--- a/tests/ui/seek_to_start_instead_of_rewind.fixed
+++ b/tests/ui/seek_to_start_instead_of_rewind.fixed
@@ -70,6 +70,12 @@ fn seek_to_end<T: Seek>(t: &mut T) {
t.seek(SeekFrom::End(0));
}
+// This should NOT trigger clippy warning because
+// expr is used here
+fn seek_to_start_in_let<T: Seek>(t: &mut T) {
+ let a = t.seek(SeekFrom::Start(0)).unwrap();
+}
+
fn main() {
let mut f = OpenOptions::new()
.write(true)
diff --git a/tests/ui/seek_to_start_instead_of_rewind.rs b/tests/ui/seek_to_start_instead_of_rewind.rs
index c5bc57cc3a7..467003a1a66 100644
--- a/tests/ui/seek_to_start_instead_of_rewind.rs
+++ b/tests/ui/seek_to_start_instead_of_rewind.rs
@@ -70,6 +70,12 @@ fn seek_to_end<T: Seek>(t: &mut T) {
t.seek(SeekFrom::End(0));
}
+// This should NOT trigger clippy warning because
+// expr is used here
+fn seek_to_start_in_let<T: Seek>(t: &mut T) {
+ let a = t.seek(SeekFrom::Start(0)).unwrap();
+}
+
fn main() {
let mut f = OpenOptions::new()
.write(true)
diff --git a/tests/ui/seek_to_start_instead_of_rewind.stderr b/tests/ui/seek_to_start_instead_of_rewind.stderr
index 6cce025359f..342ec00fe72 100644
--- a/tests/ui/seek_to_start_instead_of_rewind.stderr
+++ b/tests/ui/seek_to_start_instead_of_rewind.stderr
@@ -13,7 +13,7 @@ LL | t.seek(SeekFrom::Start(0));
| ^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `rewind()`
error: used `seek` to go to the start of the stream
- --> $DIR/seek_to_start_instead_of_rewind.rs:128:7
+ --> $DIR/seek_to_start_instead_of_rewind.rs:134:7
|
LL | f.seek(SeekFrom::Start(0));
| ^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `rewind()`