Mercurial > jdk8-mips64-public > nashorn / file revision

 /*

  * 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.RUN_SCRIPT;

 import static jdk.nashorn.internal.codegen.CompilerConstants.STRICT_MODE;

 import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;

 import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;

 import static jdk.nashorn.internal.runtime.linker.Lookup.MH;

 import java.io.File;

 import java.io.IOException;

 import java.io.PrintWriter;

 import java.lang.invoke.MethodHandle;

 import java.lang.invoke.MethodHandles;

 import java.lang.reflect.Constructor;

 import java.net.MalformedURLException;

 import java.net.URL;

 import java.security.AccessController;

 import java.security.CodeSigner;

 import java.security.CodeSource;

 import java.security.PrivilegedAction;

 import jdk.internal.org.objectweb.asm.ClassReader;

 import jdk.internal.org.objectweb.asm.util.CheckClassAdapter;

 import jdk.nashorn.internal.codegen.Compiler;

 import jdk.nashorn.internal.codegen.ObjectClassGenerator;

 import jdk.nashorn.internal.ir.FunctionNode;

 import jdk.nashorn.internal.ir.debug.ASTWriter;

 import jdk.nashorn.internal.ir.debug.PrintVisitor;

 import jdk.nashorn.internal.parser.Parser;

 import jdk.nashorn.internal.runtime.linker.JavaAdapterFactory;

 import jdk.nashorn.internal.runtime.options.Options;

 import sun.reflect.Reflection;

 /**

  * This class manages the global state of execution. Context is immutable.

  */

 public final class Context {

     /**

      * ContextCodeInstaller that has the privilege of installing classes in the Context.

      * Can only be instantiated from inside the context and is opaque to other classes

      */

     public static class ContextCodeInstaller implements CodeInstaller<ScriptEnvironment> {

         private final Context      context;

         private final ScriptLoader loader;

         private final CodeSource   codeSource;

         private ContextCodeInstaller(final Context context, final ScriptLoader loader, final CodeSource codeSource) {

             this.context    = context;

             this.loader     = loader;

             this.codeSource = codeSource;

         }

         /**

          * Return the context for this installer

          * @return context

          */

         @Override

         public ScriptEnvironment getOwner() {

             return context.env;

         }

         @Override

         public Class<?> install(final String className, final byte[] bytecode) {

             return loader.installClass(className, bytecode, codeSource);

         }

         @Override

         public void verify(final byte[] code) {

             context.verify(code);

         }

     }

     /** Is Context global debug mode enabled ? */

     public static final boolean DEBUG = Options.getBooleanProperty("nashorn.debug");

     private static final ThreadLocal<ScriptObject> currentGlobal =

         new ThreadLocal<ScriptObject>() {

             @Override

             protected ScriptObject initialValue() {

                  return null;

             }

         };

     /**

      * Get the current global scope

      * @return the current global scope

      */

     public static ScriptObject getGlobal() {

         final SecurityManager sm = System.getSecurityManager();

         if (sm != null) {

             // skip getCallerClass and getGlobal and get to the real caller

             Class<?> caller = Reflection.getCallerClass(2);

             ClassLoader callerLoader = caller.getClassLoader();

             // Allow this method only for nashorn's own classes, objects

             // package classes and Java adapter classes. Rest should

             // have the necessary security permission.

             if (callerLoader != myLoader &&

                 !(callerLoader instanceof StructureLoader) &&

                 !(JavaAdapterFactory.isAdapterClass(caller))) {

                 sm.checkPermission(new RuntimePermission("getNashornGlobal"));

             }

         }

         return getGlobalTrusted();

     }

     /**

      * Set the current global scope

      * @param global the global scope

      */

     public static void setGlobal(final ScriptObject global) {

         final SecurityManager sm = System.getSecurityManager();

         if (sm != null) {

             sm.checkPermission(new RuntimePermission("setNashornGlobal"));

         }

         if (global != null && !(global instanceof GlobalObject)) {

             throw new IllegalArgumentException("global does not implement GlobalObject!");

         }

         setGlobalTrusted(global);

     }

     /**

      * Get context of the current global

      * @return current global scope's context.

      */

     public static Context getContext() {

         final SecurityManager sm = System.getSecurityManager();

         if (sm != null) {

             sm.checkPermission(new RuntimePermission("getNashornContext"));

         }

         return getContextTrusted();

     }

     /**

      * Get current context's error writer

      *

      * @return error writer of the current context

      */

     public static PrintWriter getCurrentErr() {

         final ScriptObject global = getGlobalTrusted();

         return (global != null)? global.getContext().getErr() : new PrintWriter(System.err);

     }

     /**

      * Output text to this Context's error stream

      * @param str text to write

      */

     public static void err(final String str) {

         err(str, true);

     }

     /**

      * Output text to this Context's error stream, optionally with

      * a newline afterwards

      *

      * @param str  text to write

      * @param crlf write a carriage return/new line after text

      */

     @SuppressWarnings("resource")

     public static void err(final String str, final boolean crlf) {

         final PrintWriter err = Context.getCurrentErr();

         if (err != null) {

             if (crlf) {

                 err.println(str);

             } else {

                 err.print(str);

             }

         }

     }

     /** Current environment. */

     private final ScriptEnvironment env;

     /** is this context in strict mode? Cached from env. as this is used heavily. */

     public final boolean _strict;

     /** class loader to resolve classes from script. */

     private final ClassLoader  appLoader;

     /** Class loader to load classes from -classpath option, if set. */

     private final ClassLoader  classPathLoader;

     /** Class loader to load classes compiled from scripts. */

     private final ScriptLoader scriptLoader;

     /** Current error manager. */

     private final ErrorManager errors;

     /** Empty map used for seed map for JO$ objects */

     final PropertyMap emptyMap = PropertyMap.newEmptyMap(this);

     private static final ClassLoader myLoader = Context.class.getClassLoader();

     private static final StructureLoader sharedLoader;

     static {

         sharedLoader = AccessController.doPrivileged(new PrivilegedAction<StructureLoader>() {

             @Override

             public StructureLoader run() {

                 return new StructureLoader(myLoader, null);

             }

         });

     }

     /**

      * ThrowErrorManager that throws ParserException upon error conditions.

      */

     public static class ThrowErrorManager extends ErrorManager {

         @Override

         public void error(final String message) {

             throw new ParserException(message);

         }

         @Override

         public void error(final ParserException e) {

             throw e;

         }

     }

     /**

      * Constructor

      *

      * @param options options from command line or Context creator

      * @param errors  error manger

      * @param appLoader application class loader

      */

     public Context(final Options options, final ErrorManager errors, final ClassLoader appLoader) {

         this(options, errors, new PrintWriter(System.out, true), new PrintWriter(System.err, true), appLoader);

     }

     /**

      * Constructor

      *

      * @param options options from command line or Context creator

      * @param errors  error manger

      * @param out     output writer for this Context

      * @param err     error writer for this Context

      * @param appLoader application class loader

      */

     public Context(final Options options, final ErrorManager errors, final PrintWriter out, final PrintWriter err, final ClassLoader appLoader) {

         final SecurityManager sm = System.getSecurityManager();

         if (sm != null) {

             sm.checkPermission(new RuntimePermission("createNashornContext"));

         }

         this.env       = new ScriptEnvironment(options, out, err);

         this._strict   = env._strict;

         this.appLoader = appLoader;

         this.scriptLoader = (ScriptLoader)AccessController.doPrivileged(

              new PrivilegedAction<ClassLoader>() {

                 @Override

                 public ClassLoader run() {

                     final StructureLoader structureLoader = new StructureLoader(sharedLoader, Context.this);

                     return new ScriptLoader(structureLoader, Context.this);

                 }

              });

         this.errors    = errors;

         // if user passed -classpath option, make a class loader with that and set it as

         // thread context class loader so that script can access classes from that path.

         final String classPath = options.getString("classpath");

         if (! env._compile_only && classPath != null && !classPath.isEmpty()) {

             // make sure that caller can create a class loader.

             if (sm != null) {

                 sm.checkPermission(new RuntimePermission("createClassLoader"));

             }

             this.classPathLoader = NashornLoader.createClassLoader(classPath);

         } else {

             this.classPathLoader = null;

         }

         // print version info if asked.

         if (env._version) {

             getErr().println("nashorn " + Version.version());

         }

         if (env._fullversion) {

             getErr().println("nashorn full version " + Version.fullVersion());

         }

     }

     /**

      * Get the error manager for this context

      * @return error manger

      */

     public ErrorManager getErrorManager() {

         return errors;

     }

     /**

      * Get the script environment for this context

      * @return script environment

      */

     public ScriptEnvironment getEnv() {

         return env;

     }

     /**

      * Get the output stream for this context

      * @return output print writer

      */

     public PrintWriter getOut() {

         return env.getOut();

     }

     /**

      * Get the error stream for this context

      * @return error print writer

      */

     public PrintWriter getErr() {

         return env.getErr();

     }

     /**

      * Get the PropertyMap of the current global scope

      * @return the property map of the current global scope

      */

     public static PropertyMap getGlobalMap() {

         return Context.getGlobalTrusted().getMap();

     }

     /**

      * Compile a top level script.

      *

      * @param source the source

      * @param scope  the scope

      *

      * @return top level function for script

      */

     public ScriptFunction compileScript(final Source source, final ScriptObject scope) {

         return compileScript(source, scope, this.errors);

     }

     /**

      * Entry point for {@code eval}

      *

      * @param initialScope The scope of this eval call

      * @param string       Evaluated code as a String

      * @param callThis     "this" to be passed to the evaluated code

      * @param location     location of the eval call

      * @param strict       is this {@code eval} call from a strict mode code?

      *

      * @return the return value of the {@code eval}

      */

     public Object eval(final ScriptObject initialScope, final String string, final Object callThis, final Object location, final boolean strict) {

         final String  file       = (location == UNDEFINED || location == null) ? "<eval>" : location.toString();

         final Source  source     = new Source(file, string);

         final boolean directEval = location != UNDEFINED; // is this direct 'eval' call or indirectly invoked eval?

         final ScriptObject global = Context.getGlobalTrusted();

         ScriptObject scope = initialScope;

         // ECMA section 10.1.1 point 2 says eval code is strict if it begins

         // with "use strict" directive or eval direct call itself is made

         // from from strict mode code. We are passed with caller's strict mode.

         boolean strictFlag = directEval && strict;

         Class<?> clazz = null;

         try {

             clazz = compile(source, new ThrowErrorManager(), strictFlag);

         } catch (final ParserException e) {

             e.throwAsEcmaException(global);

             return null;

         }

         if (!strictFlag) {

             // We need to get strict mode flag from compiled class. This is

             // because eval code may start with "use strict" directive.

             try {

                 strictFlag = clazz.getField(STRICT_MODE.tag()).getBoolean(null);

             } catch (final NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException e) {

                 //ignored

                 strictFlag = false;

             }

         }

         // In strict mode, eval does not instantiate variables and functions

         // in the caller's environment. A new environment is created!

         if (strictFlag) {

             // Create a new scope object

             final ScriptObject strictEvalScope = ((GlobalObject)global).newObject();

             // bless it as a "scope"

             strictEvalScope.setIsScope();

             // set given scope to be it's proto so that eval can still

             // access caller environment vars in the new environment.

             strictEvalScope.setProto(scope);

             scope = strictEvalScope;

         }

         ScriptFunction func = getRunScriptFunction(clazz, scope);

         Object evalThis;

         if (directEval) {

             evalThis = (callThis instanceof ScriptObject || strictFlag) ? callThis : global;

         } else {

             evalThis = global;

         }

         return ScriptRuntime.apply(func, evalThis);

     }

     /**

      * Implementation of {@code load} Nashorn extension. Load a script file from a source

      * expression

      *

      * @param scope  the scope

      * @param from   source expression for script

      *

      * @return return value for load call (undefined)

      *

      * @throws IOException if source cannot be found or loaded

      */

     public Object load(final ScriptObject scope, final Object from) throws IOException {

         Object src = (from instanceof ConsString)?  from.toString() : from;

         Source source = null;

         // load accepts a String (which could be a URL or a file name), a File, a URL

         // or a ScriptObject that has "name" and "source" (string valued) properties.

         if (src instanceof String) {

             final String srcStr = (String)src;

             final File   file   = new File(srcStr);

             if (srcStr.indexOf(':') != -1) {

                 if (srcStr.startsWith("nashorn:")) {

                     final String resource = "resources/" + srcStr.substring("nashorn:".length());

                     // NOTE: even sandbox scripts should be able to load scripts in nashorn: scheme

                     // These scripts are always available and are loaded from nashorn.jar's resources.

                     source = AccessController.doPrivileged(

                             new PrivilegedAction<Source>() {

                                 @Override

                                 public Source run() {

                                     try {

                                         final URL resURL = Context.class.getResource(resource);

                                         return (resURL != null)? new Source(srcStr, resURL) : null;

                                     } catch (final IOException exp) {

                                         return null;

                                     }

                                 }

                             });

                 } else {

                     URL url = null;

                     try {

                         //check for malformed url. if malformed, it may still be a valid file

                         url = new URL(srcStr);

                     } catch (final MalformedURLException e) {

                         url = file.toURI().toURL();

                     }

                     source = new Source(url.toString(), url);

                 }

             } else if (file.isFile()) {

                 source = new Source(srcStr, file);

             }

         } else if (src instanceof File && ((File)src).isFile()) {

             final File file = (File)src;

             source = new Source(file.getName(), file);

         } else if (src instanceof URL) {

             final URL url = (URL)src;

             source = new Source(url.toString(), url);

         } else if (src instanceof ScriptObject) {

             final ScriptObject sobj = (ScriptObject)src;

             if (sobj.has("script") && sobj.has("name")) {

                 final String script = JSType.toString(sobj.get("script"));

                 final String name   = JSType.toString(sobj.get("name"));

                 source = new Source(name, script);

             }

         }

         if (source != null) {

             return evaluateSource(source, scope, scope);

         }

         throw typeError("cant.load.script", ScriptRuntime.safeToString(from));

     }

     /**

      * Load or get a structure class. Structure class names are based on the number of parameter fields

      * and {@link AccessorProperty} fields in them. Structure classes are used to represent ScriptObjects

      *

      * @see ObjectClassGenerator

      * @see AccessorProperty

      * @see ScriptObject

      *

      * @param fullName  full name of class, e.g. jdk.nashorn.internal.objects.JO$2P1 contains 2 fields and 1 parameter.

      *

      * @return the Class<?> for this structure

      *

      * @throws ClassNotFoundException if structure class cannot be resolved

      */

     public static Class<?> forStructureClass(final String fullName) throws ClassNotFoundException {

         return Class.forName(fullName, true, sharedLoader);

     }

     /**

      * Lookup a Java class. This is used for JSR-223 stuff linking in from

      * {@link jdk.nashorn.internal.objects.NativeJava} and {@link jdk.nashorn.internal.runtime.NativeJavaPackage}

      *

      * @param fullName full name of class to load

      *

      * @return the Class<?> for the name

      *

      * @throws ClassNotFoundException if class cannot be resolved

      */

     public Class<?> findClass(final String fullName) throws ClassNotFoundException {

         // check package access as soon as possible!

         final int index = fullName.lastIndexOf('.');

         if (index != -1) {

             final SecurityManager sm = System.getSecurityManager();

             if (sm != null) {

                 sm.checkPackageAccess(fullName.substring(0, index));

             }

         }

         // try the script -classpath loader, if that is set

         if (classPathLoader != null) {

             try {

                 return Class.forName(fullName, true, classPathLoader);

             } catch (final ClassNotFoundException ignored) {

                 // ignore, continue search

             }

         }

         // Try finding using the "app" loader.

         return Class.forName(fullName, true, appLoader);

     }

     /**

      * Hook to print stack trace for a {@link Throwable} that occurred during

      * execution

      *

      * @param t throwable for which to dump stack

      */

     public static void printStackTrace(final Throwable t) {

         if (Context.DEBUG) {

             t.printStackTrace(Context.getCurrentErr());

         }

     }

     /**

      * Verify generated bytecode before emission. This is called back from the

      * {@link ObjectClassGenerator} or the {@link Compiler}. If the "--verify-code" parameter

      * hasn't been given, this is a nop

      *

      * Note that verification may load classes -- we don't want to do that unless

      * user specified verify option. We check it here even though caller

      * may have already checked that flag

      *

      * @param bytecode bytecode to verify

      */

     public void verify(final byte[] bytecode) {

         if (env._verify_code) {

             // No verification when security manager is around as verifier

             // may load further classes - which should be avoided.

             if (System.getSecurityManager() == null) {

                 CheckClassAdapter.verify(new ClassReader(bytecode), scriptLoader, false, new PrintWriter(System.err, true));

             }

         }

     }

     /**

      * Create and initialize a new global scope object.

      *

      * @return the initialized global scope object.

      */

     public ScriptObject createGlobal() {

         return initGlobal(newGlobal());

     }

     /**

      * Create a new uninitialized global scope object

      * @return the global script object

      */

     public ScriptObject newGlobal() {

         final SecurityManager sm = System.getSecurityManager();

         if (sm != null) {

             sm.checkPermission(new RuntimePermission("createNashornGlobal"));

         }

         return newGlobalTrusted();

     }

     /**

      * Initialize given global scope object.

      *

      * @param global the global

      * @return the initialized global scope object.

      */

     public ScriptObject initGlobal(final ScriptObject global) {

         if (! (global instanceof GlobalObject)) {

             throw new IllegalArgumentException("not a global object!");

         }

         // Need only minimal global object, if we are just compiling.

         if (!env._compile_only) {

             final ScriptObject oldGlobal = Context.getGlobalTrusted();

             try {

                 Context.setGlobalTrusted(global);

                 // initialize global scope with builtin global objects

                 ((GlobalObject)global).initBuiltinObjects();

             } finally {

                 Context.setGlobalTrusted(oldGlobal);

             }

         }

         return global;

     }

     /**

      * Trusted variants - package-private

      */

     /**

      * Return the current global scope

      * @return current global scope

      */

     static ScriptObject getGlobalTrusted() {

         return currentGlobal.get();

     }

     /**

      * Set the current global scope

      */

     static void setGlobalTrusted(ScriptObject global) {

          currentGlobal.set(global);

     }

     /**

      * Return the current global's context

      * @return current global's context

      */

     static Context getContextTrusted() {

         return Context.getGlobalTrusted().getContext();

     }

     /**

      * Try to infer Context instance from the Class. If we cannot,

      * then get it from the thread local variable.

      *

      * @param clazz the class

      * @return context

      */

     static Context fromClass(final Class<?> clazz) {

         final ClassLoader loader = clazz.getClassLoader();

         Context context = null;

         if (loader instanceof NashornLoader) {

             context = ((NashornLoader)loader).getContext();

         }

         return (context != null) ? context : Context.getContextTrusted();

     }

     private Object evaluateSource(final Source source, final ScriptObject scope, final ScriptObject thiz) {

         ScriptFunction script = null;

         try {

             script = compileScript(source, scope, new Context.ThrowErrorManager());

         } catch (final ParserException e) {

             e.throwAsEcmaException();

         }

         return ScriptRuntime.apply(script, thiz);

     }

     private static ScriptFunction getRunScriptFunction(final Class<?> script, final ScriptObject scope) {

         if (script == null) {

             return null;

         }

         // Get run method - the entry point to the script

         final MethodHandle runMethodHandle =

                 MH.findStatic(

                     MethodHandles.lookup(),

                     script,

                     RUN_SCRIPT.tag(),

                     MH.type(

                         Object.class,

                         ScriptFunction.class,

                         Object.class));

         boolean strict;

         try {

             strict = script.getField(STRICT_MODE.tag()).getBoolean(null);

         } catch (final NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException e) {

             strict = false;

         }

         // Package as a JavaScript function and pass function back to shell.

         return ((GlobalObject)Context.getGlobalTrusted()).newScriptFunction(RUN_SCRIPT.tag(), runMethodHandle, scope, strict);

     }

     private ScriptFunction compileScript(final Source source, final ScriptObject scope, final ErrorManager errMan) {

         return getRunScriptFunction(compile(source, errMan, this._strict), scope);

     }

     private synchronized Class<?> compile(final Source source, final ErrorManager errMan, final boolean strict) {

         // start with no errors, no warnings.

         errMan.reset();

         GlobalObject global = null;

         Class<?> script;

         if (env._class_cache_size > 0) {

             global = (GlobalObject)Context.getGlobalTrusted();

             script = global.findCachedClass(source);

             if (script != null) {

                 return script;

             }

         }

         final FunctionNode functionNode = new Parser(env, source, errMan, strict).parse();

         if (errors.hasErrors() || env._parse_only) {

             return null;

         }

         if (env._print_ast) {

             getErr().println(new ASTWriter(functionNode));

         }

         if (env._print_parse) {

             getErr().println(new PrintVisitor(functionNode));

         }

         final URL          url    = source.getURL();

         final ScriptLoader loader = env._loader_per_compile ? createNewLoader() : scriptLoader;

         final CodeSource   cs     = url == null ? null : new CodeSource(url, (CodeSigner[])null);

         final CodeInstaller<ScriptEnvironment> installer = new ContextCodeInstaller(this, loader, cs);

         final Compiler compiler = new Compiler(installer, functionNode, strict);

         compiler.compile();

         script = compiler.install();

         if (global != null) {

             global.cacheClass(source, script);

         }

         return script;

     }

     private ScriptLoader createNewLoader() {

         return AccessController.doPrivileged(

              new PrivilegedAction<ScriptLoader>() {

                 @Override

                 public ScriptLoader run() {

                     // Generated code won't refer to any class generated by context

                     // script loader and so parent loader can be the structure

                     // loader -- which is parent of the context script loader.

                     return new ScriptLoader((StructureLoader)scriptLoader.getParent(), Context.this);

                 }

              });

     }

     private ScriptObject newGlobalTrusted() {

         try {

             final Class<?> clazz = Class.forName("jdk.nashorn.internal.objects.Global", true, scriptLoader);

             final Constructor<?> cstr = clazz.getConstructor(Context.class);

             return (ScriptObject) cstr.newInstance(this);

         } catch (final Exception e) {

             printStackTrace(e);

             if (e instanceof RuntimeException) {

                 throw (RuntimeException)e;

             }

             throw new RuntimeException(e);

         }

     }

 }