From 41b3473437deaa8c17f5841b9c1fa74f6503918f Mon Sep 17 00:00:00 2001
From: Jaroslav Tulach <jaroslav.tulach@enso.org>
Date: Sun, 18 Aug 2024 17:04:26 +0200
Subject: [PATCH] Initialize argument variables first, then RootBodyTag node

---
 .../interpreter/test/InsightForEnsoTest.java  | 39 ++++++++++++-------
 .../interpreter/runtime/IrToTruffle.scala     |  8 +++-
 2 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/engine/runtime-integration-tests/src/test/java/org/enso/interpreter/test/InsightForEnsoTest.java b/engine/runtime-integration-tests/src/test/java/org/enso/interpreter/test/InsightForEnsoTest.java
index 4c93b630291c..4f6466d63706 100644
--- a/engine/runtime-integration-tests/src/test/java/org/enso/interpreter/test/InsightForEnsoTest.java
+++ b/engine/runtime-integration-tests/src/test/java/org/enso/interpreter/test/InsightForEnsoTest.java
@@ -15,7 +15,6 @@
 import org.graalvm.polyglot.Source;
 import org.junit.After;
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 
 public class InsightForEnsoTest {
@@ -66,7 +65,6 @@ public void disposeContext() throws Exception {
     ctx = null;
   }
 
-  @Ignore
   @Test
   public void computeFactorial() throws Exception {
     var code =
@@ -95,9 +93,9 @@ public void computeFactorial() throws Exception {
     assertNotEquals("4th step: " + msgs, -1, msgs.indexOf("n=2 v=60 acc=function"));
 
     assertNotEquals(
-        "Uninitialized variables are seen as JavaScript null: " + msgs,
+        "Uninitialized variables (seen as JavaScript null) aren't there: " + msgs,
         -1,
-        msgs.indexOf("n=null v=null acc=function"));
+        msgs.indexOf("null"));
   }
 
   @Test
@@ -125,16 +123,19 @@ private void doInstantiateConstructor(boolean useAutoscoping, boolean lazy) thro
         Source.newBuilder(
                 "enso",
                 """
+                id x = x
+                init_first_switch_arg x = x
+
                 type Complex
                     Number re im
 
-                    switch n:Complex = Complex.Number n.im n.re
-                    switch_lazy (~n:Complex) = Complex.Number n.im n.re
+                    switch f=(init_first_switch_arg id) n:Complex = Complex.Number (f n.im) (f n.re)
+                    switch_lazy f=(init_first_switch_arg id) (~n:Complex) = Complex.Number (f n.im) (f n.re)
 
-                alloc1 a b = Complex.switch (Complex.Number a b)
-                alloc2 a b = Complex.switch (..Number a b)
-                alloc3 a b = Complex.switch_lazy (Complex.Number a b)
-                alloc4 a b = Complex.switch_lazy (..Number a b)
+                alloc1 a b = Complex.switch n=(Complex.Number a b)
+                alloc2 a b = Complex.switch n=(..Number a b)
+                alloc3 a b = Complex.switch_lazy n=(Complex.Number a b)
+                alloc4 a b = Complex.switch_lazy n=(..Number a b)
                 """,
                 "complex.enso")
             .build();
@@ -155,19 +156,27 @@ private void doInstantiateConstructor(boolean useAutoscoping, boolean lazy) thro
 
     var firstCons = msgs.indexOf("complex::complex.Complex::Number");
     var secondCons = msgs.lastIndexOf("complex::complex.Complex::Number");
-    var switchCall = msgs.indexOf("complex::complex.Complex.type::switch");
+    var switchInitCall = msgs.indexOf("complex::complex::init_first_switch_arg");
 
-    assertNotEquals(msgs, -1, switchCall);
+    assertNotEquals(msgs, -1, switchInitCall);
     assertNotEquals(msgs, -1, firstCons);
     assertNotEquals(msgs, -1, secondCons);
     assertTrue(
         "First constructor call must be sooner than second:\n" + msgs, firstCons < secondCons);
 
     if (useAutoscoping || lazy) {
-      assertTrue("Switch call first and then both constructors:\n" + msgs, switchCall < firstCons);
+      assertTrue(
+          "Switch call ("
+              + switchInitCall
+              + ") first and then both constructors ("
+              + firstCons
+              + "):\n"
+              + msgs,
+          switchInitCall < firstCons);
     } else {
-      assertTrue("First constructor sooner than switch call:\n" + msgs, firstCons < switchCall);
-      assertTrue("Switch call sooner than second constructor:\n" + msgs, switchCall < secondCons);
+      assertTrue("First constructor sooner than switch call:\n" + msgs, firstCons < switchInitCall);
+      assertTrue(
+          "Switch call sooner than second constructor:\n" + msgs, switchInitCall < secondCons);
     }
   }
 }
diff --git a/engine/runtime/src/main/scala/org/enso/interpreter/runtime/IrToTruffle.scala b/engine/runtime/src/main/scala/org/enso/interpreter/runtime/IrToTruffle.scala
index d315e12b902c..454be08d758e 100644
--- a/engine/runtime/src/main/scala/org/enso/interpreter/runtime/IrToTruffle.scala
+++ b/engine/runtime/src/main/scala/org/enso/interpreter/runtime/IrToTruffle.scala
@@ -2160,8 +2160,12 @@ class IrToTruffle(
       lazy val argsExpr      = computeArgsAndExpression()
 
       def args(): Array[ArgumentDefinition] = slots._2
-      def bodyNode(): RuntimeExpression =
-        BlockNode.buildRoot(argsExpr._1.toArray, argsExpr._2)
+      def bodyNode(): RuntimeExpression = {
+        val body = BlockNode.buildRoot(Array(), argsExpr._2)
+        val initVariablesAndThenBody =
+          BlockNode.buildSilent(argsExpr._1.toArray, body)
+        initVariablesAndThenBody
+      }
 
       private def computeArgsAndExpression()
         : (Array[RuntimeExpression], RuntimeExpression) = {