fix: semicolon_inside_block FP when attribute over expr is not enabled

Author: profetia

clippy_lints/src/semicolon_block.rs

@@ -155,6 +155,11 @@ impl LateLintPass<'_> for SemicolonBlock {
                 kind: ExprKind::Block(block, _),
                 ..
             }) if !block.span.from_expansion() => {
+                let attrs = cx.tcx.hir_attrs(stmt.hir_id);
+                if !attrs.is_empty() && !cx.tcx.features().stmt_expr_attributes() {
+                    return;
+                }
+
                 if let Some(tail) = block.expr {
                     self.semicolon_inside_block(cx, block, tail, stmt.span);
                 }

tests/ui/semicolon_inside_block.fixed

@@ -86,3 +86,8 @@ fn main() {
 
     unit_fn_block()
 }
+
+pub fn issue15388() {
+    #[rustfmt::skip]
+    {0; 0};
+}

tests/ui/semicolon_inside_block.rs

@@ -86,3 +86,8 @@ fn main() {
 
     unit_fn_block()
 }
+
+pub fn issue15388() {
+    #[rustfmt::skip]
+    {0; 0};
+}

tests/ui/semicolon_inside_block_stmt_expr_attrs.fixed

@@ -0,0 +1,11 @@
+// Test when the feature `stmt_expr_attributes` is enabled
+
+#![feature(stmt_expr_attributes)]
+#![allow(clippy::no_effect)]
+#![warn(clippy::semicolon_inside_block)]
+
+pub fn issue15388() {
+    #[rustfmt::skip]
+    {0; 0;}
+    //~^ semicolon_inside_block
+}

tests/ui/semicolon_inside_block_stmt_expr_attrs.rs

@@ -0,0 +1,11 @@
+// Test when the feature `stmt_expr_attributes` is enabled
+
+#![feature(stmt_expr_attributes)]
+#![allow(clippy::no_effect)]
+#![warn(clippy::semicolon_inside_block)]
+
+pub fn issue15388() {
+    #[rustfmt::skip]
+    {0; 0};
+    //~^ semicolon_inside_block
+}

tests/ui/semicolon_inside_block_stmt_expr_attrs.stderr

@@ -0,0 +1,16 @@
+error: consider moving the `;` inside the block for consistent formatting
+  --> tests/ui/semicolon_inside_block_stmt_expr_attrs.rs:9:5
+   |
+LL |     {0; 0};
+   |     ^^^^^^^
+   |
+   = note: `-D clippy::semicolon-inside-block` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::semicolon_inside_block)]`
+help: put the `;` here
+   |
+LL -     {0; 0};
+LL +     {0; 0;}
+   |
+
+error: aborting due to 1 previous error
+