Patch j.l.Object.toString() not to use getClass().

This way, `j.l.Class` is not reachable, nor the other problematic
methods of `j.l.Object`. This means we can remove the last filters
and only rely on reachability analysis.

Author: sjrd

Diff for: wasm/src/main/scala/Compiler.scala

@@ -49,15 +49,14 @@ object Compiler {
     } yield {
       val onlyModule = moduleSet.modules.head
 
-      val filteredClasses = onlyModule.classDefs.filter { c =>
-        !ExcludedClasses.contains(c.className)
-      }
+      // Sort for stability
+      val sortedClasses = onlyModule.classDefs.sortBy(_.className)
 
-      filteredClasses.sortBy(_.className).foreach(showLinkedClass(_))
+      sortedClasses.foreach(showLinkedClass(_))
 
-      Preprocessor.preprocess(filteredClasses)(context)
+      Preprocessor.preprocess(sortedClasses)(context)
       println("preprocessed")
-      filteredClasses.foreach { clazz =>
+      sortedClasses.foreach { clazz =>
         builder.transformClassDef(clazz)
       }
       onlyModule.topLevelExports.foreach { tle =>
@@ -71,13 +70,6 @@ object Compiler {
     }
   }
 
-  private val ExcludedClasses: Set[ir.Names.ClassName] = {
-    import ir.Names._
-    Set(
-      ClassClass // java.lang.Class
-    )
-  }
-
   private def showLinkedClass(clazz: LinkedClass): Unit = {
     val writer = new java.io.PrintWriter(System.out)
     val printer = new LinkedClassPrinter(writer)

Diff for: wasm/src/main/scala/ir2wasm/LibraryPatches.scala

@@ -65,6 +65,15 @@ object LibraryPatches {
 
   private val MethodPatches: Map[ClassName, List[MethodDef]] = {
     Map(
+      ObjectClass -> List(
+        // TODO Remove this patch when we support getClass() and full string concatenation
+        MethodDef(
+          EMF, m("toString", Nil, T), NON,
+          Nil, ClassType(BoxedStringClass),
+          Some(StringLiteral("[object]"))
+        )(EOH, NOV)
+      ),
+
       BoxedCharacterClass.withSuffix("$") -> List(
         MethodDef(
           EMF, m("toString", List(C), T), NON,

Diff for: wasm/src/main/scala/ir2wasm/Preprocessor.scala

@@ -17,10 +17,8 @@ object Preprocessor {
     for (clazz <- classes)
       preprocess(clazz)
 
-    for (clazz <- classes) {
-      if (clazz.className != IRNames.ObjectClass)
-        collectAbstractMethodCalls(clazz)
-    }
+    for (clazz <- classes)
+      collectAbstractMethodCalls(clazz)
   }
 
   private def preprocess(clazz: LinkedClass)(implicit ctx: WasmContext): Unit = {
@@ -34,12 +32,9 @@ object Preprocessor {
   }
 
   private def collectMethods(clazz: LinkedClass)(implicit ctx: WasmContext): Unit = {
-    val infos =
-      if (clazz.name.name == IRNames.ObjectClass) Nil
-      else
-        clazz.methods.filterNot(_.flags.namespace.isConstructor).map { method =>
-          makeWasmFunctionInfo(clazz, method)
-        }
+    val infos = clazz.methods.filterNot(_.flags.namespace.isConstructor).map { method =>
+      makeWasmFunctionInfo(clazz, method)
+    }
     ctx.putClassInfo(
       clazz.name.name,
       new WasmClassInfo(

Diff for: wasm/src/main/scala/ir2wasm/WasmBuilder.scala

@@ -69,15 +69,10 @@ class WasmBuilder {
     )
     ctx.addGCType(structType)
 
-    // Do not generate methods in Object for now
-    if (clazz.name.name == IRNames.ObjectClass)
-      clazz.methods.filter(_.name.name == IRNames.NoArgConstructorName).foreach { method =>
-        genFunction(clazz, method)
-      }
-    else
-      clazz.methods.foreach { method =>
-        genFunction(clazz, method)
-      }
+    // implementation of methods
+    clazz.methods.foreach { method =>
+      genFunction(clazz, method)
+    }
 
     structType
   }