From cdea34017b190f08326c5f0e3124b5fcc2239035 Mon Sep 17 00:00:00 2001
From: Philipp Schuster <philipp.schuster@uni-tuebingen.de>
Date: Fri, 10 Jan 2025 16:41:46 +0100
Subject: [PATCH] Fix finding free variables

---
 .../src/main/scala/effekt/generator/llvm/Transformer.scala   | 5 ++---
 effekt/shared/src/main/scala/effekt/machine/Analysis.scala   | 2 +-
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/effekt/shared/src/main/scala/effekt/generator/llvm/Transformer.scala b/effekt/shared/src/main/scala/effekt/generator/llvm/Transformer.scala
index 476ad2329..355cd41a1 100644
--- a/effekt/shared/src/main/scala/effekt/generator/llvm/Transformer.scala
+++ b/effekt/shared/src/main/scala/effekt/generator/llvm/Transformer.scala
@@ -110,15 +110,14 @@ object Transformer {
 
       case machine.Switch(value, clauses, default) =>
         emit(Comment(s"switch ${value.name}, ${clauses.length} clauses"))
-        shareValues(List(value), clauses.flatMap(freeVariables).toSet)
+        val freeInClauses = clauses.flatMap(freeVariables) ++ default.map(freeVariables).getOrElse(Set.empty)
+        shareValues(List(value), freeInClauses.toSet)
 
         val tagName = freshName("tag")
         val objectName = freshName("fields")
         emit(ExtractValue(tagName, transform(value), 0))
         emit(ExtractValue(objectName, transform(value), 1))
 
-        val freeInClauses = clauses.flatMap(freeVariables)
-
         val stack = getStack()
         def labelClause(clause: machine.Clause): String = {
           implicit val BC = BlockContext()
diff --git a/effekt/shared/src/main/scala/effekt/machine/Analysis.scala b/effekt/shared/src/main/scala/effekt/machine/Analysis.scala
index 06bb92ce0..b3dc6915b 100644
--- a/effekt/shared/src/main/scala/effekt/machine/Analysis.scala
+++ b/effekt/shared/src/main/scala/effekt/machine/Analysis.scala
@@ -24,7 +24,7 @@ def freeVariables(statement: Statement): Set[Variable] =
     case Construct(name, tag, values, rest) =>
       Set.from(values) ++ (freeVariables(rest) -- Set(name))
     case Switch(value, clauses, default: Option[Clause]) =>
-      Set(value) ++ clauses.flatMap { case (tag, branch) => freeVariables(branch) } ++ default.map(freeVariables).getOrElse(Set.empty)
+      Set(value) ++ clauses.flatMap(freeVariables) ++ default.map(freeVariables).getOrElse(Set.empty)
     case New(name, clauses, rest) =>
       freeVariables(clauses) ++ (freeVariables(rest) -- Set(name))
     case Invoke(value, tag, values) =>