[semicolon_if_nothing_returned]: add an autofix

clippy_lints/src/semicolon_if_nothing_returned.rs

@@ -43,7 +43,7 @@ impl<'tcx> LateLintPass<'tcx> for SemicolonIfNothingReturned {
             if let Some(expr) = block.expr;
             let t_expr = cx.typeck_results().expr_ty(expr);
             if t_expr.is_unit();
-            let mut app = Applicability::MaybeIncorrect;
+            let mut app = Applicability::MachineApplicable;
             if let snippet = snippet_with_context(cx, expr.span, block.span.ctxt(), "}", &mut app).0;
             if !snippet.ends_with('}') && !snippet.ends_with(';');
             if cx.sess().source_map().is_multiline(block.span);

tests/ui/semicolon_if_nothing_returned.fixed

@@ -0,0 +1,123 @@
+//@run-rustfix
+#![warn(clippy::semicolon_if_nothing_returned)]
+#![allow(clippy::redundant_closure, clippy::uninlined_format_args, clippy::needless_late_init)]
+
+fn get_unit() {}
+
+// the functions below trigger the lint
+fn main() {
+    println!("Hello");
+}
+
+fn hello() {
+    get_unit();
+}
+
+fn basic101(x: i32) {
+    let y: i32;
+    y = x + 1;
+}
+
+#[rustfmt::skip]
+fn closure_error() {
+    let _d = || {
+        hello();
+    };
+}
+
+#[rustfmt::skip]
+fn unsafe_checks_error() {
+    use std::mem::MaybeUninit;
+    use std::ptr;
+
+    let mut s = MaybeUninit::<String>::uninit();
+    let _d = || unsafe {
+        ptr::drop_in_place(s.as_mut_ptr());
+    };
+}
+
+// this is fine
+fn print_sum(a: i32, b: i32) {
+    println!("{}", a + b);
+    assert_eq!(true, false);
+}
+
+fn foo(x: i32) {
+    let y: i32;
+    if x < 1 {
+        y = 4;
+    } else {
+        y = 5;
+    }
+}
+
+fn bar(x: i32) {
+    let y: i32;
+    match x {
+        1 => y = 4,
+        _ => y = 32,
+    }
+}
+
+fn foobar(x: i32) {
+    let y: i32;
+    'label: {
+        y = x + 1;
+    }
+}
+
+fn loop_test(x: i32) {
+    let y: i32;
+    for &ext in &["stdout", "stderr", "fixed"] {
+        println!("{}", ext);
+    }
+}
+
+fn closure() {
+    let _d = || hello();
+}
+
+#[rustfmt::skip]
+fn closure_block() {
+    let _d = || { hello() };
+}
+
+unsafe fn some_unsafe_op() {}
+unsafe fn some_other_unsafe_fn() {}
+
+fn do_something() {
+    unsafe { some_unsafe_op() };
+
+    unsafe { some_other_unsafe_fn() };
+}
+
+fn unsafe_checks() {
+    use std::mem::MaybeUninit;
+    use std::ptr;
+
+    let mut s = MaybeUninit::<String>::uninit();
+    let _d = || unsafe { ptr::drop_in_place(s.as_mut_ptr()) };
+}
+
+// Issue #7768
+#[rustfmt::skip]
+fn macro_with_semicolon() {
+    macro_rules! repro {
+        () => {
+            while false {
+            }
+        };
+    }
+    repro!();
+}
+
+fn function_returning_option() -> Option<i32> {
+    Some(1)
+}
+
+// No warning
+fn let_else_stmts() {
+    let Some(x) = function_returning_option() else {
+        return;
+    };
+}

tests/ui/semicolon_if_nothing_returned.rs

@@ -1,5 +1,6 @@
+//@run-rustfix
 #![warn(clippy::semicolon_if_nothing_returned)]
-#![allow(clippy::redundant_closure, clippy::uninlined_format_args)]
+#![allow(clippy::redundant_closure, clippy::uninlined_format_args, clippy::needless_late_init)]
 
 fn get_unit() {}
 

tests/ui/semicolon_if_nothing_returned.stderr

@@ -1,31 +1,31 @@
 error: consider adding a `;` to the last statement for consistent formatting
-  --> $DIR/semicolon_if_nothing_returned.rs:8:5
+  --> $DIR/semicolon_if_nothing_returned.rs:9:5
    |
 LL |     println!("Hello")
    |     ^^^^^^^^^^^^^^^^^ help: add a `;` here: `println!("Hello");`
    |
    = note: `-D clippy::semicolon-if-nothing-returned` implied by `-D warnings`
 
 error: consider adding a `;` to the last statement for consistent formatting
-  --> $DIR/semicolon_if_nothing_returned.rs:12:5
+  --> $DIR/semicolon_if_nothing_returned.rs:13:5
    |
 LL |     get_unit()
    |     ^^^^^^^^^^ help: add a `;` here: `get_unit();`
 
 error: consider adding a `;` to the last statement for consistent formatting
-  --> $DIR/semicolon_if_nothing_returned.rs:17:5
+  --> $DIR/semicolon_if_nothing_returned.rs:18:5
    |
 LL |     y = x + 1
    |     ^^^^^^^^^ help: add a `;` here: `y = x + 1;`
 
 error: consider adding a `;` to the last statement for consistent formatting
-  --> $DIR/semicolon_if_nothing_returned.rs:23:9
+  --> $DIR/semicolon_if_nothing_returned.rs:24:9
    |
 LL |         hello()
    |         ^^^^^^^ help: add a `;` here: `hello();`
 
 error: consider adding a `;` to the last statement for consistent formatting
-  --> $DIR/semicolon_if_nothing_returned.rs:34:9
+  --> $DIR/semicolon_if_nothing_returned.rs:35:9
    |
 LL |         ptr::drop_in_place(s.as_mut_ptr())
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: add a `;` here: `ptr::drop_in_place(s.as_mut_ptr());`