nashorn/src/jdk/nashorn/internal/runtime/DebuggerSupport.java - edge/openjdk - Git at Google

 /*
  * 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.SOURCE;
 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT;

 import java.lang.invoke.MethodHandle;
 import java.lang.reflect.Field;
 import java.net.URL;
 import java.util.HashSet;
 import java.util.Set;
 import jdk.nashorn.internal.scripts.JS;

 /**
  * This class provides support for external debuggers.  Its primary purpose is
  * is to simplify the debugger tasks and provide better performance.
  * Even though the methods are not public, there are still part of the
  * external debugger interface.
  */
 final class DebuggerSupport {
     /**
      * Hook to force the loading of the DebuggerSupport class so that it is
      * available to external debuggers.
      */
     static boolean FORCELOAD = true;

     static {
         /**
          * Hook to force the loading of the DebuggerValueDesc class so that it is
          * available to external debuggers.
          */
         @SuppressWarnings("unused")
         final
         DebuggerValueDesc forceLoad = new DebuggerValueDesc(null, false, null, null);

         // Hook to force the loading of the SourceInfo class
         @SuppressWarnings("unused")
         final
         SourceInfo srcInfo = new SourceInfo(null, 0, null, null);
     }

     /** This class is used to send a bulk description of a value. */
     static class DebuggerValueDesc {
         /** Property key (or index) or field name. */
         final String key;

         /** If the value is expandable. */
         final boolean expandable;

         /** Property or field value as object. */
         final Object valueAsObject;

         /** Property or field value as string. */
         final String valueAsString;

         DebuggerValueDesc(final String key, final boolean expandable, final Object valueAsObject, final String valueAsString) {
             this.key           = key;
             this.expandable    = expandable;
             this.valueAsObject = valueAsObject;
             this.valueAsString = valueAsString;
         }
     }

     static class SourceInfo {
         final String name;
         final URL    url;
         final int    hash;
         final char[] content;

         SourceInfo(final String name, final int hash, final URL url, final char[] content) {
             this.name    = name;
             this.hash    = hash;
             this.url     = url;
             this.content = content;
         }
     }

     /**
      * Hook that is called just before invoking method handle
      * from ScriptFunctionData via invoke, constructor method calls.
      *
      * @param mh script class method about to be invoked.
      */
     static void notifyInvoke(final MethodHandle mh) {
         // Do nothing here. This is placeholder method on which a
         // debugger can place a breakpoint so that it can access the
         // (script class) method handle that is about to be invoked.
         // See ScriptFunctionData.invoke and ScriptFunctionData.construct.
     }

     /**
      * Return the script source info for the given script class.
      *
      * @param clazz compiled script class
      * @return SourceInfo
      */
     static SourceInfo getSourceInfo(final Class<?> clazz) {
         if (JS.class.isAssignableFrom(clazz)) {
             try {
                 final Field sourceField = clazz.getDeclaredField(SOURCE.symbolName());
                 sourceField.setAccessible(true);
                 final Source src = (Source) sourceField.get(null);
                 return src.getSourceInfo();
             } catch (final IllegalAccessException | NoSuchFieldException ignored) {
                 return null;
             }
         }

         return null;
     }

     /**
      * Return the current context global.
      * @return context global.
      */
     static Object getGlobal() {
         return Context.getGlobal();
     }

     /**
      * Call eval on the current global.
      * @param scope           Scope to use.
      * @param self            Receiver to use.
      * @param string          String to evaluate.
      * @param returnException true if exceptions are to be returned.
      * @return Result of eval, or, an exception or null depending on returnException.
      */
     static Object eval(final ScriptObject scope, final Object self, final String string, final boolean returnException) {
         final ScriptObject global = Context.getGlobal();
         final ScriptObject initialScope = scope != null ? scope : global;
         final Object callThis = self != null ? self : global;
         final Context context = global.getContext();

         try {
             return context.eval(initialScope, string, callThis, ScriptRuntime.UNDEFINED);
         } catch (final Throwable ex) {
             return returnException ? ex : null;
         }
     }

     /**
      * This method returns a bulk description of an object's properties.
      * @param object Script object to be displayed by the debugger.
      * @param all    true if to include non-enumerable values.
      * @return An array of DebuggerValueDesc.
      */
     static DebuggerValueDesc[] valueInfos(final Object object, final boolean all) {
         assert object instanceof ScriptObject;
         return getDebuggerValueDescs((ScriptObject)object, all, new HashSet<>());
     }

     /**
      * This method returns a debugger description of the value.
      * @param name  Name of value (property name).
      * @param value Data value.
      * @param all   true if to include non-enumerable values.
      * @return A DebuggerValueDesc.
      */
     static DebuggerValueDesc valueInfo(final String name, final Object value, final boolean all) {
         return valueInfo(name, value, all, new HashSet<>());
     }

    /**
      * This method returns a debugger description of the value.
      * @param name       Name of value (property name).
      * @param value      Data value.
      * @param all        true if to include non-enumerable values.
      * @param duplicates Duplication set to avoid cycles.
      * @return A DebuggerValueDesc.
      */
     private static DebuggerValueDesc valueInfo(final String name, final Object value, final boolean all, final Set<Object> duplicates) {
         if (value instanceof ScriptObject && !(value instanceof ScriptFunction)) {
             final ScriptObject object = (ScriptObject)value;
             return new DebuggerValueDesc(name, !object.isEmpty(), value, objectAsString(object, all, duplicates));
         }
         return new DebuggerValueDesc(name, false, value, valueAsString(value));
     }

     /**
      * Generate the descriptions for an object's properties.
      * @param object     Object to introspect.
      * @param all        true if to include non-enumerable values.
      * @param duplicates Duplication set to avoid cycles.
      * @return An array of DebuggerValueDesc.
      */
     private static DebuggerValueDesc[] getDebuggerValueDescs(final ScriptObject object, final boolean all, final Set<Object> duplicates) {
         if (duplicates.contains(object)) {
             return null;
         }

         duplicates.add(object);

         final String[] keys = object.getOwnKeys(all);
         final DebuggerValueDesc[] descs = new DebuggerValueDesc[keys.length];

         for (int i = 0; i < keys.length; i++) {
             final String key = keys[i];
             descs[i] = valueInfo(key, object.get(key), all, duplicates);
         }

         duplicates.remove(object);

         return descs;
     }

     /**
      * Generate a string representation of a Script object.
      * @param object     Script object to represent.
      * @param all        true if to include non-enumerable values.
      * @param duplicates Duplication set to avoid cycles.
      * @return String representation.
      */
     private static String objectAsString(final ScriptObject object, final boolean all, final Set<Object> duplicates) {
         final StringBuilder sb = new StringBuilder();

         if (ScriptObject.isArray(object)) {
             sb.append('[');
             final long length = (long) object.getDouble("length", INVALID_PROGRAM_POINT);

             for (long i = 0; i < length; i++) {
                 if (object.has(i)) {
                     final Object valueAsObject = object.get(i);
                     final boolean isUndefined = valueAsObject == ScriptRuntime.UNDEFINED;

                     if (isUndefined) {
                         if (i != 0) {
                             sb.append(",");
                         }
                     } else {
                         if (i != 0) {
                             sb.append(", ");
                         }

                         if (valueAsObject instanceof ScriptObject && !(valueAsObject instanceof ScriptFunction)) {
                             final String objectString = objectAsString((ScriptObject)valueAsObject, all, duplicates);
                             sb.append(objectString != null ? objectString : "{...}");
                         } else {
                             sb.append(valueAsString(valueAsObject));
                         }
                     }
                 } else {
                     if (i != 0) {
                         sb.append(',');
                     }
                 }
             }

             sb.append(']');
         } else {
             sb.append('{');
             final DebuggerValueDesc[] descs = getDebuggerValueDescs(object, all, duplicates);

             if (descs != null) {
                 for (int i = 0; i < descs.length; i++) {
                     if (i != 0) {
                         sb.append(", ");
                     }

                     final String valueAsString = descs[i].valueAsString;
                     sb.append(descs[i].key);
                     sb.append(": ");
                     sb.append(valueAsString);
                 }
             }

             sb.append('}');
         }

         return sb.toString();
     }

     /**
      * This method returns a string representation of a value.
      * @param value Arbitrary value to be displayed by the debugger.
      * @return A string representation of the value or an array of DebuggerValueDesc.
      */
     static String valueAsString(final Object value) {
         final JSType type = JSType.of(value);

         switch (type) {
         case BOOLEAN:
             return value.toString();

         case STRING:
             return escape(value.toString());

         case NUMBER:
             return JSType.toString(((Number)value).doubleValue());

         case NULL:
             return "null";

         case UNDEFINED:
             return "undefined";

         case OBJECT:
             return ScriptRuntime.safeToString(value);

         case FUNCTION:
             if (value instanceof ScriptFunction) {
                 return ((ScriptFunction)value).toSource();
             }
             return value.toString();

         default:
             return value.toString();
         }
     }

     /**
      * Escape a string into a form that can be parsed by JavaScript.
      * @param value String to be escaped.
      * @return Escaped string.
      */
     private static String escape(final String value) {
         final StringBuilder sb = new StringBuilder();

         sb.append("\"");

         for (final char ch : value.toCharArray()) {
             switch (ch) {
             case '\\':
                 sb.append("\\\\");
                 break;
             case '"':
                 sb.append("\\\"");
                 break;
             case '\'':
                 sb.append("\\\'");
                 break;
             case '\b':
                 sb.append("\\b");
                 break;
             case '\f':
                 sb.append("\\f");
                 break;
             case '\n':
                 sb.append("\\n");
                 break;
             case '\r':
                 sb.append("\\r");
                 break;
             case '\t':
                 sb.append("\\t");
                 break;
             default:
                 if (ch < ' ' || ch >= 0xFF) {
                     sb.append("\\u");

                     final String hex = Integer.toHexString(ch);
                     for (int i = hex.length(); i < 4; i++) {
                         sb.append('0');
                     }
                     sb.append(hex);
                 } else {
                     sb.append(ch);
                 }

                 break;
             }
         }

         sb.append("\"");

         return sb.toString();
     }
 }
	/*
	* 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.SOURCE;
	import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT;

	import java.lang.invoke.MethodHandle;
	import java.lang.reflect.Field;
	import java.net.URL;
	import java.util.HashSet;
	import java.util.Set;
	import jdk.nashorn.internal.scripts.JS;

	/**
	* This class provides support for external debuggers. Its primary purpose is
	* is to simplify the debugger tasks and provide better performance.
	* Even though the methods are not public, there are still part of the
	* external debugger interface.
	*/
	final class DebuggerSupport {
	/**
	* Hook to force the loading of the DebuggerSupport class so that it is
	* available to external debuggers.
	*/
	static boolean FORCELOAD = true;

	static {
	/**
	* Hook to force the loading of the DebuggerValueDesc class so that it is
	* available to external debuggers.
	*/
	@SuppressWarnings("unused")
	final
	DebuggerValueDesc forceLoad = new DebuggerValueDesc(null, false, null, null);

	// Hook to force the loading of the SourceInfo class
	@SuppressWarnings("unused")
	final
	SourceInfo srcInfo = new SourceInfo(null, 0, null, null);
	}

	/** This class is used to send a bulk description of a value. */
	static class DebuggerValueDesc {
	/** Property key (or index) or field name. */
	final String key;

	/** If the value is expandable. */
	final boolean expandable;

	/** Property or field value as object. */
	final Object valueAsObject;

	/** Property or field value as string. */
	final String valueAsString;

	DebuggerValueDesc(final String key, final boolean expandable, final Object valueAsObject, final String valueAsString) {
	this.key = key;
	this.expandable = expandable;
	this.valueAsObject = valueAsObject;
	this.valueAsString = valueAsString;
	}
	}

	static class SourceInfo {
	final String name;
	final URL url;
	final int hash;
	final char[] content;

	SourceInfo(final String name, final int hash, final URL url, final char[] content) {
	this.name = name;
	this.hash = hash;
	this.url = url;
	this.content = content;
	}
	}

	/**
	* Hook that is called just before invoking method handle
	* from ScriptFunctionData via invoke, constructor method calls.
	*
	* @param mh script class method about to be invoked.
	*/
	static void notifyInvoke(final MethodHandle mh) {
	// Do nothing here. This is placeholder method on which a
	// debugger can place a breakpoint so that it can access the
	// (script class) method handle that is about to be invoked.
	// See ScriptFunctionData.invoke and ScriptFunctionData.construct.
	}

	/**
	* Return the script source info for the given script class.
	*
	* @param clazz compiled script class
	* @return SourceInfo
	*/
	static SourceInfo getSourceInfo(final Class<?> clazz) {
	if (JS.class.isAssignableFrom(clazz)) {
	try {
	final Field sourceField = clazz.getDeclaredField(SOURCE.symbolName());
	sourceField.setAccessible(true);
	final Source src = (Source) sourceField.get(null);
	return src.getSourceInfo();
	} catch (final IllegalAccessException \| NoSuchFieldException ignored) {
	return null;
	}
	}

	return null;
	}

	/**
	* Return the current context global.
	* @return context global.
	*/
	static Object getGlobal() {
	return Context.getGlobal();
	}

	/**
	* Call eval on the current global.
	* @param scope Scope to use.
	* @param self Receiver to use.
	* @param string String to evaluate.
	* @param returnException true if exceptions are to be returned.
	* @return Result of eval, or, an exception or null depending on returnException.
	*/
	static Object eval(final ScriptObject scope, final Object self, final String string, final boolean returnException) {
	final ScriptObject global = Context.getGlobal();
	final ScriptObject initialScope = scope != null ? scope : global;
	final Object callThis = self != null ? self : global;
	final Context context = global.getContext();

	try {
	return context.eval(initialScope, string, callThis, ScriptRuntime.UNDEFINED);
	} catch (final Throwable ex) {
	return returnException ? ex : null;
	}
	}

	/**
	* This method returns a bulk description of an object's properties.
	* @param object Script object to be displayed by the debugger.
	* @param all true if to include non-enumerable values.
	* @return An array of DebuggerValueDesc.
	*/
	static DebuggerValueDesc[] valueInfos(final Object object, final boolean all) {
	assert object instanceof ScriptObject;
	return getDebuggerValueDescs((ScriptObject)object, all, new HashSet<>());
	}

	/**
	* This method returns a debugger description of the value.
	* @param name Name of value (property name).
	* @param value Data value.
	* @param all true if to include non-enumerable values.
	* @return A DebuggerValueDesc.
	*/
	static DebuggerValueDesc valueInfo(final String name, final Object value, final boolean all) {
	return valueInfo(name, value, all, new HashSet<>());
	}

	/**
	* This method returns a debugger description of the value.
	* @param name Name of value (property name).
	* @param value Data value.
	* @param all true if to include non-enumerable values.
	* @param duplicates Duplication set to avoid cycles.
	* @return A DebuggerValueDesc.
	*/
	private static DebuggerValueDesc valueInfo(final String name, final Object value, final boolean all, final Set<Object> duplicates) {
	if (value instanceof ScriptObject && !(value instanceof ScriptFunction)) {
	final ScriptObject object = (ScriptObject)value;
	return new DebuggerValueDesc(name, !object.isEmpty(), value, objectAsString(object, all, duplicates));
	}
	return new DebuggerValueDesc(name, false, value, valueAsString(value));
	}

	/**
	* Generate the descriptions for an object's properties.
	* @param object Object to introspect.
	* @param all true if to include non-enumerable values.
	* @param duplicates Duplication set to avoid cycles.
	* @return An array of DebuggerValueDesc.
	*/
	private static DebuggerValueDesc[] getDebuggerValueDescs(final ScriptObject object, final boolean all, final Set<Object> duplicates) {
	if (duplicates.contains(object)) {
	return null;
	}

	duplicates.add(object);

	final String[] keys = object.getOwnKeys(all);
	final DebuggerValueDesc[] descs = new DebuggerValueDesc[keys.length];

	for (int i = 0; i < keys.length; i++) {
	final String key = keys[i];
	descs[i] = valueInfo(key, object.get(key), all, duplicates);
	}

	duplicates.remove(object);

	return descs;
	}

	/**
	* Generate a string representation of a Script object.
	* @param object Script object to represent.
	* @param all true if to include non-enumerable values.
	* @param duplicates Duplication set to avoid cycles.
	* @return String representation.
	*/
	private static String objectAsString(final ScriptObject object, final boolean all, final Set<Object> duplicates) {
	final StringBuilder sb = new StringBuilder();

	if (ScriptObject.isArray(object)) {
	sb.append('[');
	final long length = (long) object.getDouble("length", INVALID_PROGRAM_POINT);

	for (long i = 0; i < length; i++) {
	if (object.has(i)) {
	final Object valueAsObject = object.get(i);
	final boolean isUndefined = valueAsObject == ScriptRuntime.UNDEFINED;

	if (isUndefined) {
	if (i != 0) {
	sb.append(",");
	}
	} else {
	if (i != 0) {
	sb.append(", ");
	}

	if (valueAsObject instanceof ScriptObject && !(valueAsObject instanceof ScriptFunction)) {
	final String objectString = objectAsString((ScriptObject)valueAsObject, all, duplicates);
	sb.append(objectString != null ? objectString : "{...}");
	} else {
	sb.append(valueAsString(valueAsObject));
	}
	}
	} else {
	if (i != 0) {
	sb.append(',');
	}
	}
	}

	sb.append(']');
	} else {
	sb.append('{');
	final DebuggerValueDesc[] descs = getDebuggerValueDescs(object, all, duplicates);

	if (descs != null) {
	for (int i = 0; i < descs.length; i++) {
	if (i != 0) {
	sb.append(", ");
	}

	final String valueAsString = descs[i].valueAsString;
	sb.append(descs[i].key);
	sb.append(": ");
	sb.append(valueAsString);
	}
	}

	sb.append('}');
	}

	return sb.toString();
	}

	/**
	* This method returns a string representation of a value.
	* @param value Arbitrary value to be displayed by the debugger.
	* @return A string representation of the value or an array of DebuggerValueDesc.
	*/
	static String valueAsString(final Object value) {
	final JSType type = JSType.of(value);

	switch (type) {
	case BOOLEAN:
	return value.toString();

	case STRING:
	return escape(value.toString());

	case NUMBER:
	return JSType.toString(((Number)value).doubleValue());

	case NULL:
	return "null";

	case UNDEFINED:
	return "undefined";

	case OBJECT:
	return ScriptRuntime.safeToString(value);

	case FUNCTION:
	if (value instanceof ScriptFunction) {
	return ((ScriptFunction)value).toSource();
	}
	return value.toString();

	default:
	return value.toString();
	}
	}

	/**
	* Escape a string into a form that can be parsed by JavaScript.
	* @param value String to be escaped.
	* @return Escaped string.
	*/
	private static String escape(final String value) {
	final StringBuilder sb = new StringBuilder();

	sb.append("\"");

	for (final char ch : value.toCharArray()) {
	switch (ch) {
	case '\\':
	sb.append("\\\\");
	break;
	case '"':
	sb.append("\\\"");
	break;
	case '\'':
	sb.append("\\\'");
	break;
	case '\b':
	sb.append("\\b");
	break;
	case '\f':
	sb.append("\\f");
	break;
	case '\n':
	sb.append("\\n");
	break;
	case '\r':
	sb.append("\\r");
	break;
	case '\t':
	sb.append("\\t");
	break;
	default:
	if (ch < ' ' \|\| ch >= 0xFF) {
	sb.append("\\u");

	final String hex = Integer.toHexString(ch);
	for (int i = hex.length(); i < 4; i++) {
	sb.append('0');
	}
	sb.append(hex);
	} else {
	sb.append(ch);
	}

	break;
	}
	}

	sb.append("\"");

	return sb.toString();
	}
	}