src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/ECMAException.java
changeset 47216 71c04702a3d5
parent 27357 8caab9a29b62
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/ECMAException.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,298 @@
+/*
+ * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.nashorn.internal.runtime;
+
+import static jdk.nashorn.internal.codegen.CompilerConstants.staticCallNoLookup;
+import static jdk.nashorn.internal.codegen.CompilerConstants.virtualField;
+import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;
+
+import javax.script.ScriptException;
+import jdk.nashorn.api.scripting.NashornException;
+import jdk.nashorn.internal.codegen.CompilerConstants.Call;
+import jdk.nashorn.internal.codegen.CompilerConstants.FieldAccess;
+
+/**
+ * Exception used to implement ECMAScript "throw" from scripts. The actual thrown
+ * object from script need not be a Java exception and so it is wrapped as an
+ * instance field called "thrown" here. This exception class is also used to
+ * represent ECMA errors thrown from runtime code (for example, TypeError,
+ * ReferenceError thrown from Nashorn engine runtime).
+ */
+@SuppressWarnings("serial")
+public final class ECMAException extends NashornException {
+    /**
+     * Method handle pointing to the constructor {@link ECMAException#create(Object, String, int, int)},
+     */
+    public static final Call CREATE = staticCallNoLookup(ECMAException.class, "create", ECMAException.class, Object.class, String.class, int.class, int.class);
+
+    /** Field handle to the{@link ECMAException#thrown} field, so that it can be accessed from generated code */
+    public static final FieldAccess THROWN = virtualField(ECMAException.class, "thrown", Object.class);
+
+    private static final String EXCEPTION_PROPERTY = "nashornException";
+
+    /** Object thrown. */
+    public final Object thrown;
+
+    /**
+     * Constructor. Called from the factory method 'create'.
+     *
+     * @param thrown    object to be thrown
+     * @param fileName  script file name
+     * @param line      line number of throw
+     * @param column    column number of throw
+     */
+    private ECMAException(final Object thrown, final String fileName, final int line, final int column) {
+        super(ScriptRuntime.safeToString(thrown), asThrowable(thrown), fileName, line, column);
+        this.thrown = thrown;
+        setExceptionToThrown();
+    }
+
+    /**
+     * Constructor. This is called from the runtime code.
+     *
+     * @param thrown   object to be thrown
+     * @param cause    Java exception that triggered this throw
+     */
+    public ECMAException(final Object thrown, final Throwable cause) {
+        super(ScriptRuntime.safeToString(thrown), cause);
+        this.thrown = thrown;
+        setExceptionToThrown();
+    }
+
+    /**
+     * Factory method to retrieve the underlying exception or create an exception.
+     * This method is called from the generated code.
+     *
+     * @param thrown    object to be thrown
+     * @param fileName  script file name
+     * @param line      line number of throw
+     * @param column    column number of throw
+     * @return ECMAException object
+     */
+    public static ECMAException create(final Object thrown, final String fileName, final int line, final int column) {
+        // If thrown object is an Error or sub-object like TypeError, then
+        // an ECMAException object has been already initialized at constructor.
+        if (thrown instanceof ScriptObject) {
+            final Object exception = getException((ScriptObject)thrown);
+            if (exception instanceof ECMAException) {
+                final ECMAException ee = (ECMAException)exception;
+                // Make sure exception has correct thrown reference because that's what will end up getting caught.
+                if (ee.getThrown() == thrown) {
+                    // copy over file name, line number and column number.
+                    ee.setFileName(fileName);
+                    ee.setLineNumber(line);
+                    ee.setColumnNumber(column);
+                    return ee;
+                }
+            }
+        }
+
+        return new ECMAException(thrown, fileName, line, column);
+    }
+
+    /**
+     * Get the thrown object
+     * @return thrown object
+     */
+    @Override
+    public Object getThrown() {
+        return thrown;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder sb = new StringBuilder();
+        final String fileName = getFileName();
+        final int line = getLineNumber();
+        final int column = getColumnNumber();
+
+        if (fileName != null) {
+            sb.append(fileName);
+            if (line >= 0) {
+                sb.append(':');
+                sb.append(line);
+            }
+            if (column >= 0) {
+                sb.append(':');
+                sb.append(column);
+            }
+            sb.append(' ');
+        } else {
+            sb.append("ECMAScript Exception: ");
+        }
+
+        sb.append(getMessage());
+        return sb.toString();
+    }
+
+    /**
+     * Get the {@link ECMAException}, i.e. the underlying Java object for the
+     * JavaScript error object from a {@link ScriptObject} representing an error
+     *
+     * @param errObj the error object
+     * @return a {@link ECMAException}
+     */
+    public static Object getException(final ScriptObject errObj) {
+        // Exclude inherited properties that may belong to errors in the prototype chain.
+        if (errObj.hasOwnProperty(ECMAException.EXCEPTION_PROPERTY)) {
+            return errObj.get(ECMAException.EXCEPTION_PROPERTY);
+        }
+        return null;
+    }
+
+    /**
+     * Print the stack trace for a {@code ScriptObject} representing an error
+     *
+     * @param errObj the error object
+     * @return undefined
+     */
+    public static Object printStackTrace(final ScriptObject errObj) {
+        final Object exception = getException(errObj);
+        if (exception instanceof Throwable) {
+            ((Throwable)exception).printStackTrace(Context.getCurrentErr());
+        } else {
+            Context.err("<stack trace not available>");
+        }
+        return UNDEFINED;
+    }
+
+    /**
+     * Get the line number for a {@code ScriptObject} representing an error
+     *
+     * @param errObj the error object
+     * @return the line number, or undefined if wrapped exception is not a ParserException
+     */
+    public static Object getLineNumber(final ScriptObject errObj) {
+        final Object e = getException(errObj);
+        if (e instanceof NashornException) {
+            return ((NashornException)e).getLineNumber();
+        } else if (e instanceof ScriptException) {
+            return ((ScriptException)e).getLineNumber();
+        }
+
+        return UNDEFINED;
+    }
+
+    /**
+     * Get the column number for a {@code ScriptObject} representing an error
+     *
+     * @param errObj the error object
+     * @return the column number, or undefined if wrapped exception is not a ParserException
+     */
+    public static Object getColumnNumber(final ScriptObject errObj) {
+        final Object e = getException(errObj);
+        if (e instanceof NashornException) {
+            return ((NashornException)e).getColumnNumber();
+        } else if (e instanceof ScriptException) {
+            return ((ScriptException)e).getColumnNumber();
+        }
+
+        return UNDEFINED;
+    }
+
+    /**
+     * Get the file name for a {@code ScriptObject} representing an error
+     *
+     * @param errObj the error object
+     * @return the file name, or undefined if wrapped exception is not a ParserException
+     */
+    public static Object getFileName(final ScriptObject errObj) {
+        final Object e = getException(errObj);
+        if (e instanceof NashornException) {
+            return ((NashornException)e).getFileName();
+        } else if (e instanceof ScriptException) {
+            return ((ScriptException)e).getFileName();
+        }
+
+        return UNDEFINED;
+    }
+
+    /**
+     * Stateless string conversion for an error object
+     *
+     * @param errObj the error object
+     * @return string representation of {@code errObj}
+     */
+    public static String safeToString(final ScriptObject errObj) {
+        Object name = UNDEFINED;
+        try {
+            name = errObj.get("name");
+        } catch (final Exception e) {
+            //ignored
+        }
+
+        if (name == UNDEFINED) {
+            name = "Error";
+        } else {
+            name = ScriptRuntime.safeToString(name);
+        }
+
+        Object msg = UNDEFINED;
+        try {
+            msg = errObj.get("message");
+        } catch (final Exception e) {
+            //ignored
+        }
+
+        if (msg == UNDEFINED) {
+            msg = "";
+        } else {
+            msg = ScriptRuntime.safeToString(msg);
+        }
+
+        if (((String)name).isEmpty()) {
+            return (String)msg;
+        }
+
+        if (((String)msg).isEmpty()) {
+            return (String)name;
+        }
+
+        return name + ": " + msg;
+    }
+
+    private static Throwable asThrowable(final Object obj) {
+        return (obj instanceof Throwable)? (Throwable)obj : null;
+    }
+
+    private void setExceptionToThrown() {
+        /*
+         * Nashorn extension: errorObject.nashornException
+         * Expose this exception via "nashornException" property of on the
+         * thrown object. This exception object can be used to print stack
+         * trace and fileName, line number etc. from script code.
+         */
+
+        if (thrown instanceof ScriptObject) {
+            final ScriptObject sobj = (ScriptObject)thrown;
+            if (!sobj.has(EXCEPTION_PROPERTY)) {
+                sobj.addOwnProperty(EXCEPTION_PROPERTY, Property.NOT_ENUMERABLE, this);
+            } else {
+                sobj.set(EXCEPTION_PROPERTY, this, 0);
+            }
+        }
+    }
+}