Merge pull request #13 from sjrd/upcast-downcast-hijacked-classes

Fix #12: Implement the behavior of hijacked classes.

build.sbt

@@ -1,5 +1,17 @@
+import org.scalajs.linker.interface.OutputPatterns
+
 val scalaV = "2.13.12"
 
+inThisBuild(Def.settings(
+  scalacOptions ++= Seq(
+    "-encoding",
+    "utf-8",
+    "-feature",
+    "-deprecation",
+    "-Xfatal-warnings",
+  )
+))
+
 lazy val cli = project
   .in(file("cli"))
   .enablePlugins(ScalaJSPlugin)
@@ -86,7 +98,10 @@ lazy val tests = project
       "org.scala-js" %%% "scala-js-macrotask-executor" % "1.1.1" % Test
     ),
     scalaJSLinkerConfig ~= {
-      _.withModuleKind(ModuleKind.CommonJSModule),
+      // Generate CoreTests as an ES module so that it can import the loader.mjs
+      // Give it an `.mjs` extension so that Node.js actually interprets it as an ES module
+      _.withModuleKind(ModuleKind.ESModule)
+        .withOutputPatterns(OutputPatterns.fromJSFile("%s.mjs")),
     },
     test := Def.sequential(
       (testSuite / Compile / run).toTask(""),

cli/src/main/scala/TestSuites.scala

@@ -9,6 +9,9 @@ object TestSuites {
     TestSuite("testsuite.core.virtualdispatch.VirtualDispatch", "virtualDispatch"),
     TestSuite("testsuite.core.interfacecall.InterfaceCall", "interfaceCall"),
     TestSuite("testsuite.core.asinstanceof.AsInstanceOfTest", "asInstanceOf"),
-    TestSuite("testsuite.core.hijackedclassesmono.HijackedClassesMonoTest", "hijackedClassesMono")
+    TestSuite("testsuite.core.hijackedclassesdispatch.HijackedClassesDispatchTest", "hijackedClassesDispatch"),
+    TestSuite("testsuite.core.hijackedclassesmono.HijackedClassesMonoTest", "hijackedClassesMono"),
+    TestSuite("testsuite.core.hijackedclassesupcast.HijackedClassesUpcastTest", "hijackedClassesUpcast"),
+    TestSuite("testsuite.core.tostring.ToStringTest", "toStringConversions")
   )
 }

loader.mjs

@@ -0,0 +1,90 @@
+import { readFileSync } from "node:fs";
+
+// Specified by java.lang.String.hashCode()
+function stringHashCode(s) {
+  var res = 0;
+  var mul = 1;
+  var i = (s.length - 1) | 0;
+  while ((i >= 0)) {
+    res = ((res + Math.imul(s.charCodeAt(i), mul)) | 0);
+    mul = Math.imul(31, mul);
+    i = (i - 1) | 0;
+  }
+  return res;
+}
+
+const scalaJSHelpers = {
+  // BinaryOp.===
+  is: Object.is,
+
+  // undefined
+  undef: () => void 0,
+  isUndef: (x) => x === (void 0),
+
+  // Boxes (upcast) -- most are identity at the JS level but with different types in Wasm
+  bZ: (x) => x !== 0,
+  bB: (x) => x,
+  bS: (x) => x,
+  bI: (x) => x,
+  bF: (x) => x,
+  bD: (x) => x,
+
+  // Unboxes (downcast, null is converted to the zero of the type)
+  uZ: (x) => x | 0,
+  uB: (x) => (x << 24) >> 24,
+  uS: (x) => (x << 16) >> 16,
+  uI: (x) => x | 0,
+  uF: (x) => Math.fround(x),
+  uD: (x) => +x,
+
+  // Unboxes to primitive or null (downcast to the boxed classes)
+  uNZ: (x) => (x !== null) ? (x | 0) : null,
+  uNB: (x) => (x !== null) ? ((x << 24) >> 24) : null,
+  uNS: (x) => (x !== null) ? ((x << 16) >> 16) : null,
+  uNI: (x) => (x !== null) ? (x | 0) : null,
+  uNF: (x) => (x !== null) ? Math.fround(x) : null,
+  uND: (x) => (x !== null) ? +x : null,
+
+  // Type tests
+  tZ: (x) => typeof x === 'boolean',
+  tB: (x) => typeof x === 'number' && Object.is((x << 24) >> 24, x),
+  tS: (x) => typeof x === 'number' && Object.is((x << 16) >> 16, x),
+  tI: (x) => typeof x === 'number' && Object.is(x | 0, x),
+  tF: (x) => typeof x === 'number' && (Math.fround(x) === x || x !== x),
+  tD: (x) => typeof x === 'number',
+
+  // Strings
+  emptyString: () => "",
+  stringLength: (s) => s.length,
+  stringCharAt: (s, i) => s.charCodeAt(i),
+  jsValueToString: (x) => "" + x,
+  booleanToString: (b) => b ? "true" : "false",
+  charToString: (c) => String.fromCharCode(c),
+  intToString: (i) => "" + i,
+  longToString: (l) => "" + l, // l must be a bigint here
+  doubleToString: (d) => "" + d,
+  stringConcat: (x, y) => ("" + x) + y, // the added "" is for the case where x === y === null
+  isString: (x) => typeof x === 'string',
+
+  // Hash code, because it is overridden in all hijacked classes
+  // Specified by the hashCode() method of the corresponding hijacked classes
+  jsValueHashCode: (x) => {
+    if (typeof x === 'number')
+      return x | 0; // TODO make this compliant for floats
+    if (typeof x === 'string')
+      return stringHashCode(x);
+    if (typeof x === 'boolean')
+      return x ? 1231 : 1237;
+    if (typeof x === 'undefined')
+      return 0;
+    return 42; // for any JS object
+  },
+}
+
+export async function load(wasmFileName) {
+  const wasmBuffer = readFileSync(wasmFileName);
+  const wasmModule = await WebAssembly.instantiate(wasmBuffer, {
+    "__scalaJSHelpers": scalaJSHelpers,
+  });
+  return wasmModule.instance.exports;
+}

run.mjs

@@ -1,6 +1,5 @@
-import { readFileSync } from "node:fs";
-const wasmBuffer = readFileSync("./target/output.wasm");
-const wasmModule = await WebAssembly.instantiate(wasmBuffer);
-const { test } = wasmModule.instance.exports;
+import { load } from "./loader.mjs";
+
+const { test } = await load("./target/output.wasm");
 const o = test();
 console.log(o);

test-suite/src/main/scala/testsuite/core/HijackedClassesDispatchTest.scala

@@ -0,0 +1,93 @@
+package testsuite.core.hijackedclassesdispatch
+
+import scala.scalajs.js.annotation._
+
+object HijackedClassesDispatchTest {
+  def main(): Unit = { val _ = test() }
+
+  @JSExportTopLevel("hijackedClassesDispatch")
+  def test(): Boolean = {
+    val obj = new Test()
+    val otherObj = new Test()
+    val obj2 = new Test2()
+    val otherObj2 = new Test2()
+    testToString(true, "true") &&
+      testToString(54321, "54321") &&
+      testToString(obj, "Test class") &&
+      testToString(obj2, "[object]") &&
+      testToString('A', "A") &&
+      testHashCode(true, 1231) &&
+      testHashCode(54321, 54321) &&
+      testHashCode("foo", 101574) &&
+      testHashCode(obj, 123) &&
+      testHashCode(obj2, 42) &&
+      testHashCode('A', 65) &&
+      testIntValue(Int.box(5), 5) &&
+      testIntValue(Long.box(6L), 6) &&
+      testIntValue(Double.box(7.5), 7) &&
+      testIntValue(new CustomNumber(), 789) &&
+      testLength("foo", 3) &&
+      testLength(new CustomCharSeq(), 54) &&
+      testCharAt("foobar", 3, 'b') &&
+      testCharAt(new CustomCharSeq(), 3, 'A') &&
+      testEquals(true, 1, false) &&
+      testEquals(1.0, 1, true) &&
+      testEquals("foo", "foo", true) &&
+      testEquals("foo", "bar", false) &&
+      testEquals(obj, obj2, false) &&
+      testEquals(obj, otherObj, true) &&
+      testEquals(obj2, otherObj2, false) &&
+      testNotifyAll(true) &&
+      testNotifyAll(obj)
+  }
+
+  def testToString(x: Any, expected: String): Boolean =
+    x.toString() == expected
+
+  def testHashCode(x: Any, expected: Int): Boolean =
+    x.hashCode() == expected
+
+  def testIntValue(x: Number, expected: Int): Boolean =
+    x.intValue() == expected
+
+  def testLength(x: CharSequence, expected: Int): Boolean =
+    x.length() == expected
+
+  def testCharAt(x: CharSequence, i: Int, expected: Char): Boolean =
+    x.charAt(i) == expected
+
+  def testEquals(x: Any, y: Any, expected: Boolean): Boolean =
+    x.asInstanceOf[AnyRef].equals(y) == expected
+
+  def testNotifyAll(x: Any): Boolean = {
+    // This is just to test that the call validates and does not trap
+    x.asInstanceOf[AnyRef].notifyAll()
+    true
+  }
+
+  class Test {
+    override def toString(): String = "Test class"
+
+    override def hashCode(): Int = 123
+
+    override def equals(that: Any): Boolean =
+      that.isInstanceOf[Test]
+  }
+
+  class Test2
+
+  class CustomNumber() extends Number {
+    def value(): Int = 789
+    def intValue(): Int = value()
+    def longValue(): Long = 789L
+    def floatValue(): Float = 789.0f
+    def doubleValue(): Double = 789.0
+  }
+
+  class CustomCharSeq extends CharSequence {
+    def length(): Int = 54
+    override def toString(): String = "CustomCharSeq"
+    def charAt(index: Int): Char = 'A'
+    def subSequence(start: Int, end: Int): CharSequence = this
+  }
+}

test-suite/src/main/scala/testsuite/core/HijackedClassesUpcastTest.scala

@@ -0,0 +1,80 @@
+package testsuite.core.hijackedclassesupcast
+
+import scala.scalajs.js.annotation._
+
+object HijackedClassesUpcastTest {
+  def main(): Unit = { val _ = test() }
+
+  @JSExportTopLevel("hijackedClassesUpcast")
+  def test(): Boolean = {
+    testBoolean(true) &&
+      testInteger(5) &&
+      testIntegerNull(null) &&
+      testString("foo") &&
+      testStringNull(null) &&
+      testCharacter('A')
+  }
+
+  def testBoolean(x: Boolean): Boolean = {
+    val x1 = identity(x)
+    x1 && {
+      val x2: Any = x1
+      x2 match {
+        case x3: Boolean => x3
+        case _           => false
+      }
+    }
+  }
+
+  def testInteger(x: Int): Boolean = {
+    val x1 = identity(x)
+    x1 == 5 && {
+      val x2: Any = x1
+      x2 match {
+        case x3: Int => x3 + 1 == 6
+        case _       => false
+      }
+    }
+  }
+
+  def testIntegerNull(x: Any): Boolean = {
+    !x.isInstanceOf[Int] &&
+      !x.isInstanceOf[java.lang.Integer] &&
+      (x.asInstanceOf[Int] == 0) && {
+        val x2 = x.asInstanceOf[java.lang.Integer]
+        x2 == null
+      }
+  }
+
+  def testString(x: String): Boolean = {
+    val x1 = identity(x)
+    x1.length() == 3 && {
+      val x2: Any = x1
+      x2 match {
+        case x3: String => x3.length() == 3
+        case _          => false
+      }
+    }
+  }
+
+  def testStringNull(x: Any): Boolean = {
+    !x.isInstanceOf[String] && {
+      val x2 = x.asInstanceOf[String]
+      x2 == null
+    }
+  }
+
+  def testCharacter(x: Char): Boolean = {
+    val x1 = identity(x)
+    x1 == 'A' && {
+      val x2: Any = x1
+      x2 match {
+        case x3: Char => (x3 + 1).toChar == 'B'
+        case _        => false
+      }
+    }
+  }
+
+  @noinline
+  def identity[A](x: A): A = x
+}