fix: checking block emptiness (#3878)

rust-lang · Oct 26, 2019 · ed7c032 · ed7c032
1 parent 4967523
commit ed7c032
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Showing 13 changed files with 157 additions and 124 deletions.
diff --git a/src/expr.rs b/src/expr.rs
@@ -421,7 +421,7 @@ fn rewrite_empty_block(
     prefix: &str,
     shape: Shape,
 ) -> Option<String> {
-    if !block.stmts.is_empty() {
+    if block_has_statements(&block) {
         return None;
     }
 
@@ -1165,14 +1165,27 @@ pub(crate) fn is_simple_block_stmt(
         && attrs.map_or(true, |a| a.is_empty())
 }
 
+fn block_has_statements(block: &ast::Block) -> bool {
+    block.stmts.iter().any(|stmt| {
+        if let ast::StmtKind::Semi(ref expr) = stmt.kind {
+            if let ast::ExprKind::Tup(ref tup_exprs) = expr.kind {
+                if tup_exprs.is_empty() {
+                    return false;
+                }
+            }
+        }
+        true
+    })
+}
+
 /// Checks whether a block contains no statements, expressions, comments, or
 /// inner attributes.
 pub(crate) fn is_empty_block(
     context: &RewriteContext<'_>,
     block: &ast::Block,
     attrs: Option<&[ast::Attribute]>,
 ) -> bool {
-    block.stmts.is_empty()
+    !block_has_statements(&block)
         && !block_contains_comment(context, block)
         && attrs.map_or(true, |a| inner_attributes(a).is_empty())
 }

diff --git a/tests/source/control-brace-style-always-next-line.rs b/tests/source/control-brace-style-always-next-line.rs
@@ -2,33 +2,33 @@
 
 fn main() {
     loop {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
         }
 
 
-    'label: loop // loop comment  
+    'label: loop // loop comment
     {
-        ();
+        let foo = ();
     }
 
 
     cond = true;
     while cond {
-        ();
+        let foo = ();
     }
 
 
     'while_label: while cond { // while comment
-        ();
+        let foo = ();
     }
 
 
     for obj in iter {
         for sub_obj in obj
         {
             'nested_while_label: while cond {
-                ();
+                let foo = ();
             }
         }
     }

diff --git a/tests/source/control-brace-style-always-same-line.rs b/tests/source/control-brace-style-always-same-line.rs
@@ -1,32 +1,32 @@
 fn main() {
     loop {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
         }
 
 
-    'label: loop // loop comment  
+    'label: loop // loop comment
     {
-        ();
+        let foo = ();
     }
 
 
     cond = true;
     while cond {
-        ();
+        let foo = ();
     }
 
 
     'while_label: while cond { // while comment
-        ();
+        let foo = ();
     }
 
 
     for obj in iter {
         for sub_obj in obj
         {
             'nested_while_label: while cond {
-                ();
+                let foo = ();
             }
         }
     }

diff --git a/tests/source/else-if-brace-style-always-next-line.rs b/tests/source/else-if-brace-style-always-next-line.rs
@@ -3,14 +3,14 @@
 fn main() {
     if false
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     if false // lone if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
 
@@ -26,29 +26,29 @@ fn main() {
 
     if true
     {
-        ();
+        let foo = ();
     } else if false {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
     else {
-        ();
-        ();
-        ();
+        let foo = ();
+        let bar = ();
+        let baz = ();
     }
 
     if true // else-if-chain if comment
     {
-        ();
+        let foo = ();
     }
     else if false // else-if-chain else-if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     } else // else-if-chain else comment
     {
-        ();
-        ();
-        ();
+        let foo = ();
+        let bar = ();
+        let baz = ();
     }
 }
diff --git a/tests/source/else-if-brace-style-always-same-line.rs b/tests/source/else-if-brace-style-always-same-line.rs
@@ -1,14 +1,14 @@
 fn main() {
     if false
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     if false // lone if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
 
@@ -24,29 +24,29 @@ fn main() {
 
     if true
     {
-        ();
+        let foo = ();
     } else if false {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
     else {
-        ();
-        ();
-        ();
+        let foo = ();
+        let bar = ();
+        let baz = ();
     }
 
     if true // else-if-chain if comment
     {
-        ();
+        let foo = ();
     }
     else if false // else-if-chain else-if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     } else // else-if-chain else comment
     {
-        ();
-        ();
-        ();
+        let foo = ();
+        let bar = ();
+        let baz = ();
     }
 }
diff --git a/tests/source/else-if-brace-style-closing-next-line.rs b/tests/source/else-if-brace-style-closing-next-line.rs
@@ -3,14 +3,14 @@
 fn main() {
     if false
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     if false // lone if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
 
@@ -26,29 +26,29 @@ fn main() {
 
     if true
     {
-        ();
+        let foo = ();
     } else if false {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
     else {
-        ();
-        ();
-        ();
+        let foo = ();
+        let bar = ();
+        let baz = ();
     }
 
     if true // else-if-chain if comment
     {
-        ();
+        let foo = ();
     }
     else if false // else-if-chain else-if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     } else // else-if-chain else comment
     {
-        ();
-        ();
-        ();
+        let foo = ();
+        let bar = ();
+        let baz = ();
     }
 }
diff --git a/tests/source/issue_3868.rs b/tests/source/issue_3868.rs
@@ -0,0 +1,13 @@
+fn foo() {
+    ;
+}
+
+fn bar() {
+    for _ in 0..1 {
+        ;
+    }
+}
+
+fn baz() {
+    ();
+    }
diff --git a/tests/target/control-brace-style-always-next-line.rs b/tests/target/control-brace-style-always-next-line.rs
@@ -3,26 +3,26 @@
 fn main() {
     loop
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     'label: loop
     // loop comment
     {
-        ();
+        let foo = ();
     }
 
     cond = true;
     while cond
     {
-        ();
+        let foo = ();
     }
 
     'while_label: while cond
     {
         // while comment
-        ();
+        let foo = ();
     }
 
     for obj in iter
@@ -31,7 +31,7 @@ fn main() {
         {
             'nested_while_label: while cond
             {
-                ();
+                let foo = ();
             }
         }
     }

diff --git a/tests/target/control-brace-style-always-same-line.rs b/tests/target/control-brace-style-always-same-line.rs
@@ -1,29 +1,29 @@
 fn main() {
     loop {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     'label: loop
     // loop comment
     {
-        ();
+        let foo = ();
     }
 
     cond = true;
     while cond {
-        ();
+        let foo = ();
     }
 
     'while_label: while cond {
         // while comment
-        ();
+        let foo = ();
     }
 
     for obj in iter {
         for sub_obj in obj {
             'nested_while_label: while cond {
-                ();
+                let foo = ();
             }
         }
     }