From 0c8951d0156622c9ff8760fdf5fe7248809821c9 Mon Sep 17 00:00:00 2001
From: Karol Stasiak <karol.m.stasiak@gmail.com>
Date: Mon, 13 Sep 2021 09:27:34 +0200
Subject: [PATCH] Fix unused variable elimination in for-array statements
 (fixes #125)

---
 src/main/scala/millfork/node/Node.scala       |  2 +-
 .../scala/millfork/test/ForArraySuite.scala   | 32 +++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/main/scala/millfork/node/Node.scala b/src/main/scala/millfork/node/Node.scala
index ff784d03..776b9326 100644
--- a/src/main/scala/millfork/node/Node.scala
+++ b/src/main/scala/millfork/node/Node.scala
@@ -813,7 +813,7 @@ case class MemsetStatement(start: Expression, size: Constant, value: Expression,
 }
 
 case class ForEachStatement(variable: String, pointerVariable: Option[String], values: Either[Expression, List[Expression]], body: List[ExecutableStatement]) extends CompoundStatement {
-  override def getAllExpressions: List[Expression] = VariableExpression(variable) :: (values.fold[List[Expression]](_ => Nil, identity) ++ body.flatMap(_.getAllExpressions))
+  override def getAllExpressions: List[Expression] = VariableExpression(variable) :: (pointerVariable.map(VariableExpression).toList ++ values.fold[List[Expression]](List(_), identity) ++ body.flatMap(_.getAllExpressions))
 
   override def getChildStatements: Seq[Statement] = body
   override def flatMap(f: ExecutableStatement => Option[ExecutableStatement]): Option[ExecutableStatement] = {
diff --git a/src/test/scala/millfork/test/ForArraySuite.scala b/src/test/scala/millfork/test/ForArraySuite.scala
index 13f2f81e..5c92675c 100644
--- a/src/test/scala/millfork/test/ForArraySuite.scala
+++ b/src/test/scala/millfork/test/ForArraySuite.scala
@@ -43,4 +43,36 @@ class ForArraySuite extends FunSuite with Matchers {
       m.readByte(0xc000) should equal(18)
     }
   }
+
+  test("Issue #125") {
+      val src = """
+        | byte output @$c000
+        | import stdio
+        | array(byte) data=[1,2,3,4]
+        | void main(){
+        |    byte i
+        |    for i:data{
+        |        output += i
+        |    }
+        |}
+      """.stripMargin
+    val m = EmuOptimizedRun(src)
+    m.readByte(0xc000) should equal(6)
+  }
+
+  test("Issue #125 (ver. 2)") {
+      val src = """
+        | byte output @$c000
+        | import stdio
+        | array(byte) data=[1,2,3,4]
+        | void main(){
+        |    byte i,v
+        |    for i,v:data{
+        |        output += v
+        |    }
+        |}
+      """.stripMargin
+    val m = EmuOptimizedRun(src)
+    m.readByte(0xc000) should equal(10)
+  }
 }