806a9dfddd
Don't warn on proc macro generated code in `needless_return` Fixes #13458 Fixes #13457 Fixes #13467 Fixes #13479 Fixes #13481 Fixes #13526 Fixes #13486 The fix is unfortunately a little more convoluted than just simply adding a `is_from_proc_macro`. That check *does* fix the issue, however it also introduces a bunch of false negatives in the tests, specifically when the returned expression is in a different syntax context, e.g. `return format!(..)`. The proc macro check builds up a start and end pattern based on the HIR nodes and compares it to a snippet of the span, however that would currently fail for `return format!(..)` because we would have the patterns `("return", <something inside of the format macro>)`, which doesn't compare equal. So we now return an empty string pattern for when it's in a different syntax context. "Hide whitespace" helps a bit for reviewing the proc macro detection change changelog: none
391 lines
6.3 KiB
Rust
391 lines
6.3 KiB
Rust
//@aux-build:proc_macros.rs
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#![feature(yeet_expr)]
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#![allow(unused)]
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#![allow(
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clippy::if_same_then_else,
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clippy::single_match,
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clippy::needless_bool,
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clippy::equatable_if_let,
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clippy::needless_else
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)]
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#![warn(clippy::needless_return)]
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extern crate proc_macros;
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use proc_macros::with_span;
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use std::cell::RefCell;
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macro_rules! the_answer {
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() => {
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42
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};
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}
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fn test_end_of_fn() -> bool {
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if true {
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// no error!
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return true;
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}
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true
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}
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fn test_no_semicolon() -> bool {
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true
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}
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#[rustfmt::skip]
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fn test_multiple_semicolon() -> bool {
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true
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}
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#[rustfmt::skip]
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fn test_multiple_semicolon_with_spaces() -> bool {
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true
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}
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fn test_if_block() -> bool {
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if true {
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true
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} else {
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false
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}
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}
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fn test_match(x: bool) -> bool {
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match x {
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true => false,
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false => {
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true
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},
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}
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}
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fn test_closure() {
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let _ = || {
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true
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};
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let _ = || true;
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}
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fn test_macro_call() -> i32 {
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the_answer!()
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}
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fn test_void_fun() {
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}
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fn test_void_if_fun(b: bool) {
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if b {
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} else {
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}
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}
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fn test_void_match(x: u32) {
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match x {
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0 => (),
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_ => (),
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}
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}
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fn test_nested_match(x: u32) {
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match x {
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0 => (),
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1 => {
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let _ = 42;
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},
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_ => (),
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}
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}
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fn temporary_outlives_local() -> String {
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let x = RefCell::<String>::default();
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return x.borrow().clone();
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}
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fn borrows_but_not_last(value: bool) -> String {
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if value {
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let x = RefCell::<String>::default();
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let _a = x.borrow().clone();
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String::from("test")
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} else {
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String::new()
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}
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}
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macro_rules! needed_return {
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($e:expr) => {
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if $e > 3 {
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return;
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}
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};
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}
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fn test_return_in_macro() {
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// This will return and the macro below won't be executed. Removing the `return` from the macro
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// will change semantics.
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needed_return!(10);
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needed_return!(0);
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}
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mod issue6501 {
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#[allow(clippy::unnecessary_lazy_evaluations)]
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fn foo(bar: Result<(), ()>) {
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bar.unwrap_or_else(|_| {})
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}
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fn test_closure() {
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let _ = || {
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};
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let _ = || {};
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}
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struct Foo;
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#[allow(clippy::unnecessary_lazy_evaluations)]
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fn bar(res: Result<Foo, u8>) -> Foo {
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res.unwrap_or_else(|_| Foo)
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}
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}
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async fn async_test_end_of_fn() -> bool {
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if true {
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// no error!
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return true;
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}
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true
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}
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async fn async_test_no_semicolon() -> bool {
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true
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}
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async fn async_test_if_block() -> bool {
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if true {
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true
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} else {
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false
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}
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}
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async fn async_test_match(x: bool) -> bool {
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match x {
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true => false,
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false => {
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true
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},
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}
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}
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async fn async_test_closure() {
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let _ = || {
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true
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};
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let _ = || true;
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}
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async fn async_test_macro_call() -> i32 {
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the_answer!()
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}
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async fn async_test_void_fun() {
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}
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async fn async_test_void_if_fun(b: bool) {
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if b {
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} else {
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}
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}
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async fn async_test_void_match(x: u32) {
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match x {
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0 => (),
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_ => (),
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}
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}
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async fn async_temporary_outlives_local() -> String {
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let x = RefCell::<String>::default();
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return x.borrow().clone();
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}
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async fn async_borrows_but_not_last(value: bool) -> String {
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if value {
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let x = RefCell::<String>::default();
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let _a = x.borrow().clone();
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String::from("test")
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} else {
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String::new()
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}
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}
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async fn async_test_return_in_macro() {
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needed_return!(10);
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needed_return!(0);
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}
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fn let_else() {
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let Some(1) = Some(1) else { return };
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}
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fn needless_return_macro() -> String {
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let _ = "foo";
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let _ = "bar";
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format!("Hello {}", "world!")
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}
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fn issue_9361(n: i32) -> i32 {
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#[expect(clippy::arithmetic_side_effects)]
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return n + n;
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}
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mod issue_12998 {
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fn expect_lint() -> i32 {
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let x = 1;
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#[expect(clippy::needless_return)]
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return x;
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}
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fn expect_group() -> i32 {
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let x = 1;
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#[expect(clippy::style)]
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return x;
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}
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fn expect_all() -> i32 {
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let x = 1;
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#[expect(clippy::all)]
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return x;
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}
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fn expect_warnings() -> i32 {
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let x = 1;
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#[expect(warnings)]
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return x;
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}
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}
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fn issue8336(x: i32) -> bool {
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if x > 0 {
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println!("something");
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true
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} else {
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false
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}
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}
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fn issue8156(x: u8) -> u64 {
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match x {
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80 => {
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10
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},
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_ => {
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100
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},
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}
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}
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// Ideally the compiler should throw `unused_braces` in this case
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fn issue9192() -> i32 {
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{
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0
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}
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}
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fn issue9503(x: usize) -> isize {
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unsafe {
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if x > 12 {
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*(x as *const isize)
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} else {
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!*(x as *const isize)
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}
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}
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}
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mod issue9416 {
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pub fn with_newline() {
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let _ = 42;
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}
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#[rustfmt::skip]
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pub fn oneline() {
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let _ = 42;
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}
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}
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fn issue9947() -> Result<(), String> {
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do yeet "hello";
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}
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// without anyhow, but triggers the same bug I believe
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#[expect(clippy::useless_format)]
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fn issue10051() -> Result<String, String> {
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if true {
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Ok(format!("ok!"))
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} else {
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Err(format!("err!"))
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}
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}
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mod issue10049 {
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fn single() -> u32 {
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if true { 1 } else { 2 }
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}
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fn multiple(b1: bool, b2: bool, b3: bool) -> u32 {
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(if b1 { 0 } else { 1 } | if b2 { 2 } else { 3 } | if b3 { 4 } else { 5 })
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}
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}
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fn test_match_as_stmt() {
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let x = 9;
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match x {
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1 => 2,
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2 => return,
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_ => 0,
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};
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}
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fn allow_works() -> i32 {
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#[allow(clippy::needless_return, clippy::match_single_binding)]
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match () {
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() => return 42,
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}
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}
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fn conjunctive_blocks() -> String {
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({ "a".to_string() } + "b" + { "c" })
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}
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fn issue12907() -> String {
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"".split("").next().unwrap().to_string()
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}
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fn issue13458() {
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with_span!(span return);
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}
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fn main() {}
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fn a(x: Option<u8>) -> Option<u8> {
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match x {
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Some(_) => None,
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None => {
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#[expect(clippy::needless_return, reason = "Use early return for errors.")]
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return None;
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},
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}
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}
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fn b(x: Option<u8>) -> Option<u8> {
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match x {
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Some(_) => None,
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None => {
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#[expect(clippy::needless_return)]
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return None;
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},
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}
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}
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