From db63877c8c82626682785c4e04a359d4bcba411f Mon Sep 17 00:00:00 2001
From: teoxoy <28601907+teoxoy@users.noreply.github.com>
Date: Tue, 15 Nov 2022 14:31:21 +0100
Subject: [PATCH] [msl-out] omit extra switch case blocks where possible

---
 src/back/msl/writer.rs         | 17 ++++++++++++++---
 tests/out/msl/control-flow.msl |  6 ++----
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/back/msl/writer.rs b/src/back/msl/writer.rs
index 7617ca9a6d..7cf6ebed62 100644
--- a/src/back/msl/writer.rs
+++ b/src/back/msl/writer.rs
@@ -2546,19 +2546,30 @@ impl<W: Write> Writer<W> {
                     for case in cases.iter() {
                         match case.value {
                             crate::SwitchValue::Integer(value) => {
-                                writeln!(self.out, "{}case {}{}: {{", lcase, value, type_postfix)?;
+                                write!(self.out, "{}case {}{}:", lcase, value, type_postfix)?;
                             }
                             crate::SwitchValue::Default => {
-                                writeln!(self.out, "{}default: {{", lcase)?;
+                                write!(self.out, "{}default:", lcase)?;
                             }
                         }
+
+                        let write_block_braces = !(case.fall_through && case.body.is_empty());
+                        if write_block_braces {
+                            writeln!(self.out, " {{")?;
+                        } else {
+                            writeln!(self.out)?;
+                        }
+
                         self.put_block(lcase.next(), &case.body, context)?;
                         if !case.fall_through
                             && case.body.last().map_or(true, |s| !s.is_terminator())
                         {
                             writeln!(self.out, "{}break;", lcase.next())?;
                         }
-                        writeln!(self.out, "{}}}", lcase)?;
+
+                        if write_block_braces {
+                            writeln!(self.out, "{}}}", lcase)?;
+                        }
                     }
                     writeln!(self.out, "{}}}", level)?;
                 }
diff --git a/tests/out/msl/control-flow.msl b/tests/out/msl/control-flow.msl
index d00b7ec18b..be396e23a8 100644
--- a/tests/out/msl/control-flow.msl
+++ b/tests/out/msl/control-flow.msl
@@ -68,8 +68,7 @@ kernel void main_(
             pos = 1;
             break;
         }
-        case 3: {
-        }
+        case 3:
         case 4: {
             pos = 2;
             break;
@@ -78,8 +77,7 @@ kernel void main_(
             pos = 3;
             break;
         }
-        default: {
-        }
+        default:
         case 6: {
             pos = 4;
             break;