Fix missing CheckNotNulls in the deserialization hacks of newInstance.

sjrd · sjrd · commit 0b94e0386d8d · 2025-01-07T20:48:36.000+01:00
diff --git a/ir/shared/src/main/scala/org/scalajs/ir/Serializers.scala b/ir/shared/src/main/scala/org/scalajs/ir/Serializers.scala
@@ -1638,10 +1638,10 @@ object Serializers {
       }
 
       def arrayLength(t: Tree)(implicit pos: Position): Tree =
-        UnaryOp(UnaryOp.Array_length, t)
+        UnaryOp(UnaryOp.Array_length, UnaryOp(UnaryOp.CheckNotNull, t))
 
       def getClass(t: Tree)(implicit pos: Position): Tree =
-        UnaryOp(UnaryOp.GetClass, t)
+        UnaryOp(UnaryOp.GetClass, UnaryOp(UnaryOp.CheckNotNull, t))
 
       val jlClassRef = ClassRef(ClassClass)
       val intArrayTypeRef = ArrayTypeRef(IntRef, 1)
diff --git a/linker/shared/src/test/scala/org/scalajs/linker/BackwardsCompatTest.scala b/linker/shared/src/test/scala/org/scalajs/linker/BackwardsCompatTest.scala
@@ -109,6 +109,33 @@ class BackwardsCompatTest {
     test(classDefs, MainTestModuleInitializers)
   }
 
+  @Test
+  def testArrayNewInstanceHacks_Issue5107(): AsyncResult = await {
+    val ReflectArrayClass = ClassName("java.lang.reflect.Array")
+
+    val ClassClassRef = ClassRef(ClassClass)
+
+    val AI = ArrayTypeRef(IntRef, 1)
+
+    /* jlr.Array.newInstance(classOf[String], 5)
+     * jlr.Array.newInstance(classOf[String], Array(5, 4))
+     */
+    val classDefs = Seq(
+      mainTestClassDef(Block(
+        systemOutPrintln(
+          ApplyStatic(EAF, ReflectArrayClass, m("newInstance", List(ClassClassRef, I), O),
+              List(ClassOf(T), int(5)))(AnyType)
+        ),
+        systemOutPrintln(
+          ApplyStatic(EAF, ReflectArrayClass, m("newInstance", List(ClassClassRef, AI), O),
+              List(ClassOf(T), ArrayValue(AI, List(int(5), int(4)))))(AnyType)
+        )
+      ))
+    )
+
+    test(classDefs, MainTestModuleInitializers)
+  }
+
   private def test(classDefs: Seq[ClassDef],
       moduleInitializers: Seq[ModuleInitializer]): Future[_] = {
     val classDefFiles = classDefs.map(MemClassDefIRFile(_))
