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| 1 | +package dotty.tools.debug |
| 2 | + |
| 3 | +import com.sun.jdi.* |
| 4 | +import dotty.tools.io.* |
| 5 | +import dotty.tools.vulpix.TestFlags |
| 6 | + |
| 7 | +import scala.jdk.CollectionConverters.* |
| 8 | + |
| 9 | +class ExpressionEvaluator( |
| 10 | + sources: Map[String, JPath], |
| 11 | + options: Array[String], |
| 12 | + classPath: String, |
| 13 | + outputDir: JPath |
| 14 | +): |
| 15 | + private val compiler = ExpressionCompilerBridge() |
| 16 | + private var uniqueID: Int = 1 |
| 17 | + |
| 18 | + /** returns the value of the evaluated expression or compiler errors */ |
| 19 | + def evaluate(expression: String, thread: ThreadReference): Either[String, String] = |
| 20 | + // We evaluate the expression at the top frame of the stack |
| 21 | + val frame = thread.frame(0) |
| 22 | + |
| 23 | + // Extract everything from the frame now because, as soon as we start using the thread |
| 24 | + // for remote execution, the frame becomes invalid |
| 25 | + val localVariables = frame.visibleVariables.asScala.toSeq |
| 26 | + val values = localVariables.map(frame.getValue) |
| 27 | + val location = frame.location |
| 28 | + val thisRef = frame.thisObject // null in a static context |
| 29 | + |
| 30 | + for expressionClassName <- compile(expression, location, localVariables) yield |
| 31 | + // we don't need to create a new classloader because we compiled the expression class |
| 32 | + // in the same outputDir as main classes |
| 33 | + val classLoader = location.declaringType.classLoader |
| 34 | + val expressionClass = thread.loadClass(classLoader, expressionClassName) |
| 35 | + |
| 36 | + val nameArray = thread.createArray( |
| 37 | + "java.lang.String", |
| 38 | + localVariables.map(v => thread.virtualMachine.mirrorOf(v.name)) |
| 39 | + ) |
| 40 | + val valueArray = thread.createArray("java.lang.Object", values.map(thread.boxIfPrimitive)) |
| 41 | + val args = Seq(thisRef, nameArray, valueArray) |
| 42 | + |
| 43 | + val exprRef = thread.newInstance(expressionClass, args) |
| 44 | + val outputValue = |
| 45 | + thread.invoke[ObjectReference](exprRef, "evaluate", "()Ljava/lang/Object;", Seq.empty) |
| 46 | + // TODO update mutated local variables |
| 47 | + thread.invoke[StringReference](outputValue, "toString", "()Ljava/lang/String;", Seq.empty) |
| 48 | + .value |
| 49 | + |
| 50 | + /** compiles the expression and returns the new expression class name to load, or compiler errors */ |
| 51 | + private def compile( |
| 52 | + expression: String, |
| 53 | + location: Location, |
| 54 | + localVariables: Seq[LocalVariable] |
| 55 | + ): Either[String, String] = |
| 56 | + // We assume there is no 2 files with the same name |
| 57 | + val sourceFile = sources(location.sourceName) |
| 58 | + val packageName = getPackageName(location.declaringType) |
| 59 | + val outputClassName = getUniqueClassName() |
| 60 | + val errorBuilder = StringBuilder() |
| 61 | + val config = ExpressionCompilerConfig( |
| 62 | + packageName = packageName, |
| 63 | + outputClassName = outputClassName, |
| 64 | + breakpointLine = location.lineNumber, |
| 65 | + expression = expression, |
| 66 | + localVariables = localVariables.toSet.map(_.name).asJava, |
| 67 | + errorReporter = errorMsg => errorBuilder.append(errorMsg), |
| 68 | + testMode = true |
| 69 | + ) |
| 70 | + val success = compiler.run(outputDir, classPath, options, sourceFile, config) |
| 71 | + val fullyQualifiedClassName = |
| 72 | + if packageName.isEmpty then outputClassName else s"$packageName.$outputClassName" |
| 73 | + if success then Right(fullyQualifiedClassName) else Left(errorBuilder.toString) |
| 74 | + end compile |
| 75 | + |
| 76 | + private def getPackageName(tpe: ReferenceType): String = |
| 77 | + tpe.name.split('.').dropRight(1).mkString(".") |
| 78 | + |
| 79 | + private def getUniqueClassName(): String = |
| 80 | + val id = uniqueID |
| 81 | + uniqueID += 1 |
| 82 | + "Expression" + id |
| 83 | + |
| 84 | + extension (thread: ThreadReference) |
| 85 | + private def boxIfPrimitive(value: Value): ObjectReference = |
| 86 | + value match |
| 87 | + case value: PrimitiveValue => box(value) |
| 88 | + case ref: ObjectReference => ref |
| 89 | + |
| 90 | + private def box(value: PrimitiveValue): ObjectReference = |
| 91 | + val (className, sig) = value match |
| 92 | + case _: BooleanValue => ("java.lang.Boolean", "(Ljava/lang/String;)Ljava/lang/Boolean;") |
| 93 | + case _: ByteValue => ("java.lang.Byte", "(Ljava/lang/String;)Ljava/lang/Byte;") |
| 94 | + case _: CharValue => ("java.lang.Character", "(C)Ljava/lang/Character;") |
| 95 | + case _: DoubleValue => ("java.lang.Double", "(Ljava/lang/String;)Ljava/lang/Double;") |
| 96 | + case _: FloatValue => ("java.lang.Float", "(Ljava/lang/String;)Ljava/lang/Float;") |
| 97 | + case _: IntegerValue => ("java.lang.Integer", "(Ljava/lang/String;)Ljava/lang/Integer;") |
| 98 | + case _: LongValue => ("java.lang.Long", "(Ljava/lang/String;)Ljava/lang/Long;") |
| 99 | + case _: ShortValue => ("java.lang.Short", "(Ljava/lang/String;)Ljava/lang/Short;") |
| 100 | + val cls = getClass(className) |
| 101 | + val args = value match |
| 102 | + case c: CharValue => Seq(c) |
| 103 | + case value => Seq(mirrorOf(value.toString)) |
| 104 | + invokeStatic(cls, "valueOf", sig, args) |
| 105 | + |
| 106 | + private def createArray(arrayType: String, values: Seq[Value]): ArrayReference = |
| 107 | + val arrayClassObject = getClass(arrayType).classObject |
| 108 | + val reflectArrayClass = getClass("java.lang.reflect.Array") |
| 109 | + val args = Seq(arrayClassObject, mirrorOf(values.size)) |
| 110 | + val sig = "(Ljava/lang/Class;I)Ljava/lang/Object;" |
| 111 | + val arrayRef = invokeStatic[ArrayReference](reflectArrayClass, "newInstance", sig, args) |
| 112 | + arrayRef.setValues(values.asJava) |
| 113 | + arrayRef |
| 114 | + |
| 115 | + /** Get the remote class if it is already loaded. Otherwise you should use loadClass. */ |
| 116 | + private def getClass(className: String): ClassType = |
| 117 | + thread.virtualMachine.classesByName(className).get(0).asInstanceOf[ClassType] |
| 118 | + |
| 119 | + private def loadClass(classLoader: ClassLoaderReference, className: String): ClassType = |
| 120 | + // Calling classLoader.loadClass would create useless class object which throws |
| 121 | + // ClassNotPreparedException. We use java.lang.Class.forName instead. |
| 122 | + val classClass = getClass("java.lang.Class") |
| 123 | + val args = Seq(mirrorOf(className), mirrorOf(true), classLoader) |
| 124 | + val sig = "(Ljava/lang/String;ZLjava/lang/ClassLoader;)Ljava/lang/Class;" |
| 125 | + invokeStatic[ClassObjectReference](classClass, "forName", sig, args) |
| 126 | + .reflectedType |
| 127 | + .asInstanceOf[ClassType] |
| 128 | + |
| 129 | + private def invokeStatic[T <: Value]( |
| 130 | + cls: ClassType, |
| 131 | + methodName: String, |
| 132 | + sig: String, |
| 133 | + args: Seq[Value] |
| 134 | + ): T = |
| 135 | + val method = cls.methodsByName(methodName, sig).get(0) |
| 136 | + remotely: |
| 137 | + cls.invokeMethod(thread, method, args.asJava, ObjectReference.INVOKE_SINGLE_THREADED) |
| 138 | + |
| 139 | + // we assume there is a single constructor, otherwise we need to add sig as parameter |
| 140 | + private def newInstance(cls: ClassType, args: Seq[Value]): ObjectReference = |
| 141 | + val constructor = cls.methodsByName("<init>").get(0) |
| 142 | + remotely: |
| 143 | + cls.newInstance(thread, constructor, args.asJava, ObjectReference.INVOKE_SINGLE_THREADED) |
| 144 | + |
| 145 | + private def invoke[T <: Value]( |
| 146 | + ref: ObjectReference, |
| 147 | + methodName: String, |
| 148 | + sig: String, |
| 149 | + args: Seq[Value] |
| 150 | + ): T = |
| 151 | + val method = ref.referenceType.methodsByName(methodName, sig).get(0) |
| 152 | + remotely: |
| 153 | + ref.invokeMethod(thread, method, args.asJava, ObjectReference.INVOKE_SINGLE_THREADED) |
| 154 | + |
| 155 | + /** wrapper for safe remote execution: |
| 156 | + * - it catches InvocationException to extract the message of the remote exception |
| 157 | + * - it disables GC on the returned |
| 158 | + */ |
| 159 | + private def remotely[T <: Value](value: => Value): T = |
| 160 | + val res = |
| 161 | + try value |
| 162 | + catch case invocationException: InvocationException => |
| 163 | + val sig = "()Ljava/lang/String;" |
| 164 | + val message = |
| 165 | + invoke[StringReference](invocationException.exception, "toString", sig, List()) |
| 166 | + throw new Exception(message.value, invocationException) |
| 167 | + // Prevent object created by the debugger to be garbage collected |
| 168 | + // In theory we should enable collection later to avoid memory leak |
| 169 | + res match |
| 170 | + case ref: ObjectReference => ref.disableCollection() |
| 171 | + case _ => |
| 172 | + res.asInstanceOf[T] |
| 173 | + |
| 174 | + private def mirrorOf(value: String): StringReference = thread.virtualMachine.mirrorOf(value) |
| 175 | + private def mirrorOf(value: Int): IntegerValue = thread.virtualMachine.mirrorOf(value) |
| 176 | + private def mirrorOf(value: Boolean): BooleanValue = thread.virtualMachine.mirrorOf(value) |
| 177 | + end extension |
| 178 | +end ExpressionEvaluator |
| 179 | + |
| 180 | +object ExpressionEvaluator: |
| 181 | + def apply( |
| 182 | + sources: Array[JFile], |
| 183 | + flags: TestFlags, |
| 184 | + classPath: String, |
| 185 | + outputDir: JFile |
| 186 | + ): ExpressionEvaluator = |
| 187 | + val sourceMap = sources.map(s => s.getName -> s.toPath).toMap |
| 188 | + val filteredOptions = flags.options.filterNot(_ == "-Ycheck:all") |
| 189 | + new ExpressionEvaluator(sourceMap, filteredOptions, classPath, outputDir.toPath) |
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