Fix #4492: Load module instance instead of calling static methods

compiler/src/dotty/tools/dotc/transform/Splicer.scala

@@ -3,14 +3,14 @@ package transform
 
 import java.io.{PrintWriter, StringWriter}
 import java.lang.reflect.Method
-import java.net.URLClassLoader
 
 import dotty.tools.dotc.ast.tpd
 import dotty.tools.dotc.core.Contexts._
 import dotty.tools.dotc.core.Decorators._
 import dotty.tools.dotc.core.Flags.Package
 import dotty.tools.dotc.core.NameKinds.FlatName
 import dotty.tools.dotc.core.Names.Name
+import dotty.tools.dotc.core.StdNames.str.MODULE_INSTANCE_FIELD
 import dotty.tools.dotc.core.quoted._
 import dotty.tools.dotc.core.Types._
 import dotty.tools.dotc.core.Symbols._
@@ -128,7 +128,9 @@ object Splicer {
     private def loadModule(sym: Symbol): (Class[_], Object) = {
       if (sym.owner.is(Package)) {
         // is top level object
-        (loadClass(sym.companionModule.fullName), null)
+        val moduleClass = loadClass(sym.fullName)
+        val moduleInstance = moduleClass.getField(MODULE_INSTANCE_FIELD).get(null)
+        (moduleClass, moduleInstance)
       } else {
         // nested object in an object
         val clazz = loadClass(sym.fullNameSeparated(FlatName))

tests/run/i4492.check

@@ -0,0 +1 @@
+Ok

tests/run/i4492/quoted_1.scala

@@ -0,0 +1,6 @@
+
+trait Index
+
+object Index {
+  inline def succ(prev: Index): Unit = ~{ '(println("Ok")) }
+}

tests/run/i4492/quoted_2.scala

@@ -0,0 +1,6 @@
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    Index.succ(null)
+  }
+}