[Wasm] Wasi stdlib implementation

KT-56608

libraries/stdlib/wasm/js/builtins/kotlin/Throwable.kt

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package kotlin
+
+import kotlin.wasm.internal.ExternalInterfaceType
+import kotlin.wasm.internal.getSimpleName
+import kotlin.wasm.internal.jsToKotlinStringAdapter
+
+/**
+ * The base class for all errors and exceptions. Only instances of this class can be thrown or caught.
+ *
+ * @param message the detail message string.
+ * @param cause the cause of this throwable.
+ */
+public open class Throwable(open val message: String?, open val cause: kotlin.Throwable?) {
+    constructor(message: String?) : this(message, null)
+
+    constructor(cause: Throwable?) : this(cause?.toString(), cause)
+
+    constructor() : this(null, null)
+
+    internal val jsStack: ExternalInterfaceType = captureStackTrace()
+
+    private var _stack: String? = null
+    internal val stack: String
+        get() {
+            var value = _stack
+            if (value == null) {
+                value = jsToKotlinStringAdapter(jsStack).removePrefix("Error\n")
+                _stack = value
+            }
+
+            return value
+        }
+
+    internal var suppressedExceptionsList: MutableList<Throwable>? = null
+
+    /**
+     * Returns the short description of this throwable consisting of the exception class name
+     * followed by the exception message if it is not null.
+     */
+    public override fun toString(): String {
+        val s = getSimpleName(this.typeInfo)
+        return if (message != null) s + ": " + message.toString() else s
+    }
+}
+
+private fun captureStackTrace(): ExternalInterfaceType =
+    js("new Error().stack")