diff options
| -rw-r--r-- | clippy_lints/src/matches/significant_drop_in_scrutinee.rs | 4 | ||||
| -rw-r--r-- | tests/ui/significant_drop_in_scrutinee.rs | 14 | ||||
| -rw-r--r-- | tests/ui/significant_drop_in_scrutinee.stderr | 18 |
3 files changed, 33 insertions, 3 deletions
diff --git a/clippy_lints/src/matches/significant_drop_in_scrutinee.rs b/clippy_lints/src/matches/significant_drop_in_scrutinee.rs index 9d8e0a69433..35f2e780d2e 100644 --- a/clippy_lints/src/matches/significant_drop_in_scrutinee.rs +++ b/clippy_lints/src/matches/significant_drop_in_scrutinee.rs @@ -2,7 +2,7 @@ use std::ops::ControlFlow; use crate::FxHashSet; use clippy_utils::diagnostics::span_lint_and_then; -use clippy_utils::source::{indent_of, snippet}; +use clippy_utils::source::{first_line_of_span, indent_of, snippet}; use clippy_utils::ty::{for_each_top_level_late_bound_region, is_copy}; use clippy_utils::{get_attr, is_lint_allowed}; use itertools::Itertools; @@ -152,7 +152,7 @@ fn set_suggestion<'tcx>(diag: &mut Diag<'_, ()>, cx: &LateContext<'tcx>, expr: & diag.multipart_suggestion( suggestion_message, vec![ - (expr.span.shrink_to_lo(), replacement), + (first_line_of_span(cx, expr.span).shrink_to_lo(), replacement), (found.found_span, scrutinee_replacement), ], Applicability::MaybeIncorrect, diff --git a/tests/ui/significant_drop_in_scrutinee.rs b/tests/ui/significant_drop_in_scrutinee.rs index e9ebd23beac..39d550398d7 100644 --- a/tests/ui/significant_drop_in_scrutinee.rs +++ b/tests/ui/significant_drop_in_scrutinee.rs @@ -850,4 +850,18 @@ async fn should_not_trigger_lint_in_async_expansion(mutex: Mutex<i32>) -> i32 { } } +fn should_trigger_lint_in_match_expr() { + let mutex = Mutex::new(State {}); + + // Should trigger lint because the lifetime of the temporary MutexGuard is surprising because it + // is preserved until the end of the match, but there is no clear indication that this is the + // case. + let _ = match mutex.lock().unwrap().foo() { + //~^ ERROR: temporary with significant `Drop` in `match` scrutinee will live until the + //~| NOTE: this might lead to deadlocks or other unexpected behavior + true => 0, + false => 1, + }; +} + fn main() {} diff --git a/tests/ui/significant_drop_in_scrutinee.stderr b/tests/ui/significant_drop_in_scrutinee.stderr index 23e38948ec5..f99d862aa6b 100644 --- a/tests/ui/significant_drop_in_scrutinee.stderr +++ b/tests/ui/significant_drop_in_scrutinee.stderr @@ -584,5 +584,21 @@ LL ~ let value = *foo_async(&mutex).await.unwrap(); LL ~ match value { | -error: aborting due to 30 previous errors +error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression + --> tests/ui/significant_drop_in_scrutinee.rs:859:19 + | +LL | let _ = match mutex.lock().unwrap().foo() { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ +... +LL | }; + | - temporary lives until here + | + = note: this might lead to deadlocks or other unexpected behavior +help: try moving the temporary above the match + | +LL ~ let value = mutex.lock().unwrap().foo(); +LL ~ let _ = match value { + | + +error: aborting due to 31 previous errors |