diff --git a/clippy_lints/src/returns.rs b/clippy_lints/src/returns.rs index 2b2a41d1601..81143d7799e 100644 --- a/clippy_lints/src/returns.rs +++ b/clippy_lints/src/returns.rs @@ -12,6 +12,7 @@ use rustc_middle::lint::in_external_macro; use rustc_middle::ty::subst::GenericArgKind; use rustc_session::{declare_lint_pass, declare_tool_lint}; use rustc_span::source_map::Span; +use rustc_span::{BytePos, Pos}; declare_clippy_lint! { /// ### What it does @@ -209,13 +210,14 @@ fn check_final_expr<'tcx>( if cx.tcx.hir().attrs(expr.hir_id).is_empty() { let borrows = inner.map_or(false, |inner| last_statement_borrows(cx, inner)); if !borrows { - emit_return_lint( - cx, - peeled_drop_expr.span, - semi_spans, - inner.as_ref().map(|i| i.span), - replacement, - ); + // check if expr return nothing + let ret_span = if inner.is_none() && replacement == RetReplacement::Empty { + extend_span_to_previous_non_ws(cx, peeled_drop_expr.span) + } else { + peeled_drop_expr.span + }; + + emit_return_lint(cx, ret_span, semi_spans, inner.as_ref().map(|i| i.span), replacement); } } }, @@ -289,3 +291,16 @@ fn last_statement_borrows<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) }) .is_some() } + +// Go backwards while encountering whitespace and extend the given Span to that point. +fn extend_span_to_previous_non_ws(cx: &LateContext<'_>, sp: Span) -> Span { + if let Ok(prev_source) = cx.sess().source_map().span_to_prev_source(sp) { + let ws = [' ', '\t', '\n']; + if let Some(non_ws_pos) = prev_source.rfind(|c| !ws.contains(&c)) { + let len = prev_source.len() - non_ws_pos - 1; + return sp.with_lo(sp.lo() - BytePos::from_usize(len)); + } + } + + sp +} diff --git a/tests/ui/needless_return.fixed b/tests/ui/needless_return.fixed index d2163b14fca..4386aaec49e 100644 --- a/tests/ui/needless_return.fixed +++ b/tests/ui/needless_return.fixed @@ -59,14 +59,11 @@ fn test_macro_call() -> i32 { } fn test_void_fun() { - } fn test_void_if_fun(b: bool) { if b { - } else { - } } @@ -82,7 +79,6 @@ fn test_nested_match(x: u32) { 0 => (), 1 => { let _ = 42; - }, _ => (), } @@ -126,7 +122,6 @@ mod issue6501 { fn test_closure() { let _ = || { - }; let _ = || {}; } @@ -179,14 +174,11 @@ async fn async_test_macro_call() -> i32 { } async fn async_test_void_fun() { - } async fn async_test_void_if_fun(b: bool) { if b { - } else { - } } @@ -269,4 +261,15 @@ fn issue9503(x: usize) -> isize { } } +mod issue9416 { + pub fn with_newline() { + let _ = 42; + } + + #[rustfmt::skip] + pub fn oneline() { + let _ = 42; + } +} + fn main() {} diff --git a/tests/ui/needless_return.rs b/tests/ui/needless_return.rs index 114414b5fac..666dc54b76b 100644 --- a/tests/ui/needless_return.rs +++ b/tests/ui/needless_return.rs @@ -269,4 +269,17 @@ fn issue9503(x: usize) -> isize { }; } +mod issue9416 { + pub fn with_newline() { + let _ = 42; + + return; + } + + #[rustfmt::skip] + pub fn oneline() { + let _ = 42; return; + } +} + fn main() {} diff --git a/tests/ui/needless_return.stderr b/tests/ui/needless_return.stderr index 047fb6c2311..a8b5d86cd55 100644 --- a/tests/ui/needless_return.stderr +++ b/tests/ui/needless_return.stderr @@ -72,26 +72,32 @@ LL | return the_answer!(); = help: remove `return` error: unneeded `return` statement - --> $DIR/needless_return.rs:62:5 + --> $DIR/needless_return.rs:61:21 | -LL | return; - | ^^^^^^ +LL | fn test_void_fun() { + | _____________________^ +LL | | return; + | |__________^ | = help: remove `return` error: unneeded `return` statement - --> $DIR/needless_return.rs:67:9 + --> $DIR/needless_return.rs:66:11 | -LL | return; - | ^^^^^^ +LL | if b { + | ___________^ +LL | | return; + | |______________^ | = help: remove `return` error: unneeded `return` statement - --> $DIR/needless_return.rs:69:9 + --> $DIR/needless_return.rs:68:13 | -LL | return; - | ^^^^^^ +LL | } else { + | _____________^ +LL | | return; + | |______________^ | = help: remove `return` @@ -104,10 +110,12 @@ LL | _ => return, = help: replace `return` with a unit value error: unneeded `return` statement - --> $DIR/needless_return.rs:85:13 + --> $DIR/needless_return.rs:84:24 | -LL | return; - | ^^^^^^ +LL | let _ = 42; + | ________________________^ +LL | | return; + | |__________________^ | = help: remove `return` @@ -144,10 +152,12 @@ LL | bar.unwrap_or_else(|_| return) = help: replace `return` with an empty block error: unneeded `return` statement - --> $DIR/needless_return.rs:129:13 + --> $DIR/needless_return.rs:128:21 | -LL | return; - | ^^^^^^ +LL | let _ = || { + | _____________________^ +LL | | return; + | |__________________^ | = help: remove `return` @@ -240,26 +250,32 @@ LL | return the_answer!(); = help: remove `return` error: unneeded `return` statement - --> $DIR/needless_return.rs:182:5 + --> $DIR/needless_return.rs:181:33 | -LL | return; - | ^^^^^^ +LL | async fn async_test_void_fun() { + | _________________________________^ +LL | | return; + | |__________^ | = help: remove `return` error: unneeded `return` statement - --> $DIR/needless_return.rs:187:9 + --> $DIR/needless_return.rs:186:11 | -LL | return; - | ^^^^^^ +LL | if b { + | ___________^ +LL | | return; + | |______________^ | = help: remove `return` error: unneeded `return` statement - --> $DIR/needless_return.rs:189:9 + --> $DIR/needless_return.rs:188:13 | -LL | return; - | ^^^^^^ +LL | } else { + | _____________^ +LL | | return; + | |______________^ | = help: remove `return` @@ -351,5 +367,24 @@ LL | return !*(x as *const isize); | = help: remove `return` -error: aborting due to 44 previous errors +error: unneeded `return` statement + --> $DIR/needless_return.rs:274:20 + | +LL | let _ = 42; + | ____________________^ +LL | | +LL | | return; + | |______________^ + | + = help: remove `return` + +error: unneeded `return` statement + --> $DIR/needless_return.rs:281:20 + | +LL | let _ = 42; return; + | ^^^^^^^ + | + = help: remove `return` + +error: aborting due to 46 previous errors