NativeFunction.java revision 1354:a5e202d6eb99
1/* 2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package jdk.nashorn.internal.objects; 27 28import static jdk.nashorn.internal.runtime.ECMAErrors.rangeError; 29import static jdk.nashorn.internal.runtime.ECMAErrors.typeError; 30import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED; 31import static jdk.nashorn.internal.runtime.Source.sourceFor; 32 33import java.lang.invoke.MethodHandle; 34import java.lang.invoke.MethodHandles; 35import java.util.List; 36import jdk.internal.dynalink.support.Lookup; 37import jdk.nashorn.api.scripting.JSObject; 38import jdk.nashorn.internal.objects.annotations.Attribute; 39import jdk.nashorn.internal.objects.annotations.Constructor; 40import jdk.nashorn.internal.objects.annotations.Function; 41import jdk.nashorn.internal.objects.annotations.ScriptClass; 42import jdk.nashorn.internal.parser.Parser; 43import jdk.nashorn.internal.runtime.Context; 44import jdk.nashorn.internal.runtime.JSType; 45import jdk.nashorn.internal.runtime.ParserException; 46import jdk.nashorn.internal.runtime.PropertyMap; 47import jdk.nashorn.internal.runtime.ScriptEnvironment; 48import jdk.nashorn.internal.runtime.ScriptFunction; 49import jdk.nashorn.internal.runtime.ScriptObject; 50import jdk.nashorn.internal.runtime.ScriptRuntime; 51import jdk.nashorn.internal.runtime.linker.Bootstrap; 52 53/** 54 * ECMA 15.3 Function Objects 55 * 56 * Note: instances of this class are never created. This class is not even a 57 * subclass of ScriptObject. But, we use this class to generate prototype and 58 * constructor for "Function". 59 */ 60@ScriptClass("Function") 61public final class NativeFunction { 62 63 /** apply arg converter handle */ 64 public static final MethodHandle TO_APPLY_ARGS = Lookup.findOwnStatic(MethodHandles.lookup(), "toApplyArgs", Object[].class, Object.class); 65 66 // initialized by nasgen 67 @SuppressWarnings("unused") 68 private static PropertyMap $nasgenmap$; 69 70 // do *not* create me! 71 private NativeFunction() { 72 throw new UnsupportedOperationException(); 73 } 74 75 /** 76 * ECMA 15.3.4.2 Function.prototype.toString ( ) 77 * 78 * @param self self reference 79 * @return string representation of Function 80 */ 81 @Function(attributes = Attribute.NOT_ENUMERABLE) 82 public static String toString(final Object self) { 83 if (!(self instanceof ScriptFunction)) { 84 throw typeError("not.a.function", ScriptRuntime.safeToString(self)); 85 } 86 return ((ScriptFunction)self).toSource(); 87 } 88 89 /** 90 * ECMA 15.3.4.3 Function.prototype.apply (thisArg, argArray) 91 * 92 * @param self self reference 93 * @param thiz {@code this} arg for apply 94 * @param array array of argument for apply 95 * @return result of apply 96 */ 97 @Function(attributes = Attribute.NOT_ENUMERABLE) 98 public static Object apply(final Object self, final Object thiz, final Object array) { 99 checkCallable(self); 100 101 final Object[] args = toApplyArgs(array); 102 103 if (self instanceof ScriptFunction) { 104 return ScriptRuntime.apply((ScriptFunction)self, thiz, args); 105 } else if (self instanceof JSObject) { 106 return ((JSObject)self).call(thiz, args); 107 } 108 throw new AssertionError("Should not reach here"); 109 } 110 111 /** 112 * Given an array-like object, converts it into a Java object array suitable for invocation of ScriptRuntime.apply 113 * or for direct invocation of the applied function. 114 * @param array the array-like object. Can be null in which case a zero-length array is created. 115 * @return the Java array 116 */ 117 public static Object[] toApplyArgs(final Object array) { 118 if (array instanceof NativeArguments) { 119 return ((NativeArguments)array).getArray().asObjectArray(); 120 } else if (array instanceof ScriptObject) { 121 // look for array-like object 122 final ScriptObject sobj = (ScriptObject)array; 123 final int n = lengthToInt(sobj.getLength()); 124 125 final Object[] args = new Object[n]; 126 for (int i = 0; i < args.length; i++) { 127 args[i] = sobj.get(i); 128 } 129 return args; 130 } else if (array instanceof Object[]) { 131 return (Object[])array; 132 } else if (array instanceof List) { 133 final List<?> list = (List<?>)array; 134 return list.toArray(new Object[list.size()]); 135 } else if (array == null || array == UNDEFINED) { 136 return ScriptRuntime.EMPTY_ARRAY; 137 } else if (array instanceof JSObject) { 138 // look for array-like JSObject object 139 final JSObject jsObj = (JSObject)array; 140 final Object len = jsObj.hasMember("length")? jsObj.getMember("length") : Integer.valueOf(0); 141 final int n = lengthToInt(len); 142 143 final Object[] args = new Object[n]; 144 for (int i = 0; i < args.length; i++) { 145 args[i] = jsObj.hasSlot(i)? jsObj.getSlot(i) : UNDEFINED; 146 } 147 return args; 148 } else { 149 throw typeError("function.apply.expects.array"); 150 } 151 } 152 153 private static int lengthToInt(final Object len) { 154 final long ln = JSType.toUint32(len); 155 // NOTE: ECMASCript 5.1 section 15.3.4.3 says length should be treated as Uint32, but we wouldn't be able to 156 // allocate a Java array of more than MAX_VALUE elements anyway, so at this point we have to throw an error. 157 // People applying a function to more than 2^31 arguments will unfortunately be out of luck. 158 if (ln > Integer.MAX_VALUE) { 159 throw rangeError("range.error.inappropriate.array.length", JSType.toString(len)); 160 } 161 return (int)ln; 162 } 163 164 private static void checkCallable(final Object self) { 165 if (!(self instanceof ScriptFunction || (self instanceof JSObject && ((JSObject)self).isFunction()))) { 166 throw typeError("not.a.function", ScriptRuntime.safeToString(self)); 167 } 168 } 169 170 /** 171 * ECMA 15.3.4.4 Function.prototype.call (thisArg [ , arg1 [ , arg2, ... ] ] ) 172 * 173 * @param self self reference 174 * @param args arguments for call 175 * @return result of call 176 */ 177 @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1) 178 public static Object call(final Object self, final Object... args) { 179 checkCallable(self); 180 181 final Object thiz = (args.length == 0) ? UNDEFINED : args[0]; 182 Object[] arguments; 183 184 if (args.length > 1) { 185 arguments = new Object[args.length - 1]; 186 System.arraycopy(args, 1, arguments, 0, arguments.length); 187 } else { 188 arguments = ScriptRuntime.EMPTY_ARRAY; 189 } 190 191 if (self instanceof ScriptFunction) { 192 return ScriptRuntime.apply((ScriptFunction)self, thiz, arguments); 193 } else if (self instanceof JSObject) { 194 return ((JSObject)self).call(thiz, arguments); 195 } 196 197 throw new AssertionError("should not reach here"); 198 } 199 200 /** 201 * ECMA 15.3.4.5 Function.prototype.bind (thisArg [, arg1 [, arg2, ...]]) 202 * 203 * @param self self reference 204 * @param args arguments for bind 205 * @return function with bound arguments 206 */ 207 @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1) 208 public static Object bind(final Object self, final Object... args) { 209 final Object thiz = (args.length == 0) ? UNDEFINED : args[0]; 210 211 Object[] arguments; 212 if (args.length > 1) { 213 arguments = new Object[args.length - 1]; 214 System.arraycopy(args, 1, arguments, 0, arguments.length); 215 } else { 216 arguments = ScriptRuntime.EMPTY_ARRAY; 217 } 218 219 return Bootstrap.bindCallable(self, thiz, arguments); 220 } 221 222 /** 223 * Nashorn extension: Function.prototype.toSource 224 * 225 * @param self self reference 226 * @return source for function 227 */ 228 @Function(attributes = Attribute.NOT_ENUMERABLE) 229 public static String toSource(final Object self) { 230 if (!(self instanceof ScriptFunction)) { 231 throw typeError("not.a.function", ScriptRuntime.safeToString(self)); 232 } 233 return ((ScriptFunction)self).toSource(); 234 } 235 236 /** 237 * ECMA 15.3.2.1 new Function (p1, p2, ... , pn, body) 238 * 239 * Constructor 240 * 241 * @param newObj is the new operator used for constructing this function 242 * @param self self reference 243 * @param args arguments 244 * @return new NativeFunction 245 */ 246 @Constructor(arity = 1) 247 public static ScriptFunction function(final boolean newObj, final Object self, final Object... args) { 248 final StringBuilder sb = new StringBuilder(); 249 250 sb.append("(function ("); 251 final String funcBody; 252 if (args.length > 0) { 253 final StringBuilder paramListBuf = new StringBuilder(); 254 for (int i = 0; i < args.length - 1; i++) { 255 paramListBuf.append(JSType.toString(args[i])); 256 if (i < args.length - 2) { 257 paramListBuf.append(","); 258 } 259 } 260 261 // now convert function body to a string 262 funcBody = JSType.toString(args[args.length - 1]); 263 264 final String paramList = paramListBuf.toString(); 265 if (!paramList.isEmpty()) { 266 checkFunctionParameters(paramList); 267 sb.append(paramList); 268 } 269 } else { 270 funcBody = null; 271 } 272 273 sb.append(") {\n"); 274 if (args.length > 0) { 275 checkFunctionBody(funcBody); 276 sb.append(funcBody); 277 sb.append('\n'); 278 } 279 sb.append("})"); 280 281 final Global global = Global.instance(); 282 final Context context = global.getContext(); 283 return (ScriptFunction)context.eval(global, sb.toString(), global, "<function>"); 284 } 285 286 private static void checkFunctionParameters(final String params) { 287 final Parser parser = getParser(params); 288 try { 289 parser.parseFormalParameterList(); 290 } catch (final ParserException pe) { 291 pe.throwAsEcmaException(); 292 } 293 } 294 295 private static void checkFunctionBody(final String funcBody) { 296 final Parser parser = getParser(funcBody); 297 try { 298 parser.parseFunctionBody(); 299 } catch (final ParserException pe) { 300 pe.throwAsEcmaException(); 301 } 302 } 303 304 private static Parser getParser(final String sourceText) { 305 final ScriptEnvironment env = Global.getEnv(); 306 return new Parser(env, sourceFor("<function>", sourceText), new Context.ThrowErrorManager(), env._strict, null); 307 } 308} 309