From 9c84d17c7c967a600fb4f29c62e08f116a9fe60c Mon Sep 17 00:00:00 2001
From: Caleb Cartwright <caleb.cartwright@outlook.com>
Date: Sun, 20 Oct 2019 23:02:52 -0500
Subject: [PATCH] fix: checking block emptiness

---
 src/expr.rs                                   | 17 ++++++++--
 .../control-brace-style-always-next-line.rs   | 14 ++++----
 .../control-brace-style-always-same-line.rs   | 14 ++++----
 .../else-if-brace-style-always-next-line.rs   | 32 +++++++++----------
 .../else-if-brace-style-always-same-line.rs   | 32 +++++++++----------
 .../else-if-brace-style-closing-next-line.rs  | 32 +++++++++----------
 tests/source/issue_3868.rs                    | 13 ++++++++
 .../control-brace-style-always-next-line.rs   | 12 +++----
 .../control-brace-style-always-same-line.rs   | 12 +++----
 .../else-if-brace-style-always-next-line.rs   | 32 +++++++++----------
 .../else-if-brace-style-always-same-line.rs   | 32 +++++++++----------
 .../else-if-brace-style-closing-next-line.rs  | 32 +++++++++----------
 tests/target/issue_3868.rs                    |  7 ++++
 13 files changed, 157 insertions(+), 124 deletions(-)
 create mode 100644 tests/source/issue_3868.rs
 create mode 100644 tests/target/issue_3868.rs

diff --git a/src/expr.rs b/src/expr.rs
index 8665f2a7248..108a9726be3 100644
--- 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;
     }
 
@@ -1137,6 +1137,19 @@ 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(
@@ -1144,7 +1157,7 @@ pub(crate) fn is_empty_block(
     attrs: Option<&[ast::Attribute]>,
     source_map: &SourceMap,
 ) -> bool {
-    block.stmts.is_empty()
+    !block_has_statements(&block)
         && !block_contains_comment(block, source_map)
         && 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
index 9079fb46c0c..25661fcef7e 100644
--- a/tests/source/control-brace-style-always-next-line.rs
+++ b/tests/source/control-brace-style-always-next-line.rs
@@ -2,25 +2,25 @@
 
 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 = ();
     }
 
 
@@ -28,7 +28,7 @@ fn main() {
         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
index 45111aaab08..b5477c7aead 100644
--- a/tests/source/control-brace-style-always-same-line.rs
+++ b/tests/source/control-brace-style-always-same-line.rs
@@ -1,24 +1,24 @@
 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 = ();
     }
 
 
@@ -26,7 +26,7 @@ fn main() {
         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
index 7b4870fc65a..e37707f7646 100644
--- 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
index 37c9417ea16..6322ba2e192 100644
--- 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
index 3b885b3faaa..4d358ae9a3a 100644
--- 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
new file mode 100644
index 00000000000..0bddd3afbb0
--- /dev/null
+++ 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
index 054a3075ca0..7b55591c6f5 100644
--- 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
index cf3f82dfcf1..aaa016cf74b 100644
--- 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 = ();
             }
         }
     }
diff --git a/tests/target/else-if-brace-style-always-next-line.rs b/tests/target/else-if-brace-style-always-next-line.rs
index 31e12cfa0d0..740213555b7 100644
--- a/tests/target/else-if-brace-style-always-next-line.rs
+++ b/tests/target/else-if-brace-style-always-next-line.rs
@@ -3,51 +3,51 @@
 fn main() {
     if false
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     if false
     // lone if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     let a = if 0 > 1 { unreachable!() } else { 0x0 };
 
     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/target/else-if-brace-style-always-same-line.rs b/tests/target/else-if-brace-style-always-same-line.rs
index 07b71fd790d..bf5b9de4ce2 100644
--- a/tests/target/else-if-brace-style-always-same-line.rs
+++ b/tests/target/else-if-brace-style-always-same-line.rs
@@ -1,43 +1,43 @@
 fn main() {
     if false {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     if false
     // lone if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     let a = if 0 > 1 { unreachable!() } else { 0x0 };
 
     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/target/else-if-brace-style-closing-next-line.rs b/tests/target/else-if-brace-style-closing-next-line.rs
index c99807dc06d..638f22bb40e 100644
--- a/tests/target/else-if-brace-style-closing-next-line.rs
+++ b/tests/target/else-if-brace-style-closing-next-line.rs
@@ -2,48 +2,48 @@
 
 fn main() {
     if false {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     if false
     // lone if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     let a = if 0 > 1 { unreachable!() } else { 0x0 };
 
     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/target/issue_3868.rs b/tests/target/issue_3868.rs
new file mode 100644
index 00000000000..902e2da01fc
--- /dev/null
+++ b/tests/target/issue_3868.rs
@@ -0,0 +1,7 @@
+fn foo() {}
+
+fn bar() {
+    for _ in 0..1 {}
+}
+
+fn baz() {}