diff --git a/clippy_lints/src/write.rs b/clippy_lints/src/write.rs index 4f771b2af55..012c34e9b53 100644 --- a/clippy_lints/src/write.rs +++ b/clippy_lints/src/write.rs @@ -201,7 +201,7 @@ fn check_mac(&mut self, cx: &EarlyContext<'_>, mac: &Mac) { } else if mac.node.path == "print" { span_lint(cx, PRINT_STDOUT, mac.span, "use of `print!`"); if let (Some(fmtstr), _, is_raw) = check_tts(cx, &mac.node.tts, false) { - if !is_raw && check_newlines(&fmtstr) { + if check_newlines(&fmtstr, is_raw) { span_lint( cx, PRINT_WITH_NEWLINE, @@ -213,7 +213,7 @@ fn check_mac(&mut self, cx: &EarlyContext<'_>, mac: &Mac) { } } else if mac.node.path == "write" { if let (Some(fmtstr), _, is_raw) = check_tts(cx, &mac.node.tts, true) { - if !is_raw && check_newlines(&fmtstr) { + if check_newlines(&fmtstr, is_raw) { span_lint( cx, WRITE_WITH_NEWLINE, @@ -382,7 +382,14 @@ fn check_tts<'a>(cx: &EarlyContext<'a>, tts: &TokenStream, is_write: bool) -> (O } // Checks if `s` constains a single newline that terminates it -fn check_newlines(s: &str) -> bool { +// Literal and escaped newlines are both checked (only literal for raw strings) +fn check_newlines(s: &str, is_raw: bool) -> bool { + if s.ends_with('\n') { + return true; + } else if is_raw { + return false; + } + if s.len() < 2 { return false; } diff --git a/tests/ui/print_with_newline.rs b/tests/ui/print_with_newline.rs index 9df4b9052de..1c219ecb325 100644 --- a/tests/ui/print_with_newline.rs +++ b/tests/ui/print_with_newline.rs @@ -29,4 +29,14 @@ fn main() { // Raw strings print!(r"\n"); // #3778 + + // Literal newlines should also fail + print!( + " +" + ); + print!( + r" +" + ); } diff --git a/tests/ui/print_with_newline.stderr b/tests/ui/print_with_newline.stderr index 1d89a16e090..ff89b0d3fd4 100644 --- a/tests/ui/print_with_newline.stderr +++ b/tests/ui/print_with_newline.stderr @@ -30,5 +30,23 @@ error: using `print!()` with a format string that ends in a single newline, cons LL | print!("//n"); // should fail | ^^^^^^^^^^^^^^ -error: aborting due to 5 previous errors +error: using `print!()` with a format string that ends in a single newline, consider using `println!()` instead + --> $DIR/print_with_newline.rs:34:5 + | +LL | / print!( +LL | | " +LL | | " +LL | | ); + | |_____^ + +error: using `print!()` with a format string that ends in a single newline, consider using `println!()` instead + --> $DIR/print_with_newline.rs:38:5 + | +LL | / print!( +LL | | r" +LL | | " +LL | | ); + | |_____^ + +error: aborting due to 7 previous errors diff --git a/tests/ui/write_with_newline.rs b/tests/ui/write_with_newline.rs index 3575dd6da80..dd80dc0cf9c 100644 --- a/tests/ui/write_with_newline.rs +++ b/tests/ui/write_with_newline.rs @@ -34,4 +34,16 @@ fn main() { // Raw strings write!(&mut v, r"\n"); // #3778 + + // Literal newlines should also fail + write!( + &mut v, + " +" + ); + write!( + &mut v, + r" +" + ); } diff --git a/tests/ui/write_with_newline.stderr b/tests/ui/write_with_newline.stderr index b0761f3b081..3a31f61a277 100644 --- a/tests/ui/write_with_newline.stderr +++ b/tests/ui/write_with_newline.stderr @@ -30,5 +30,25 @@ error: using `write!()` with a format string that ends in a single newline, cons LL | write!(&mut v, "//n"); // should fail | ^^^^^^^^^^^^^^^^^^^^^^ -error: aborting due to 5 previous errors +error: using `write!()` with a format string that ends in a single newline, consider using `writeln!()` instead + --> $DIR/write_with_newline.rs:39:5 + | +LL | / write!( +LL | | &mut v, +LL | | " +LL | | " +LL | | ); + | |_____^ + +error: using `write!()` with a format string that ends in a single newline, consider using `writeln!()` instead + --> $DIR/write_with_newline.rs:44:5 + | +LL | / write!( +LL | | &mut v, +LL | | r" +LL | | " +LL | | ); + | |_____^ + +error: aborting due to 7 previous errors