1 /*
2 * Copyright (c) 2012, 2024, 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 package java.lang.invoke;
26
27 import sun.invoke.util.Wrapper;
28
29 import java.lang.reflect.Modifier;
30
31 import static java.lang.invoke.MethodHandleInfo.*;
32 import static sun.invoke.util.Wrapper.forPrimitiveType;
33 import static sun.invoke.util.Wrapper.forWrapperType;
34 import static sun.invoke.util.Wrapper.isWrapperType;
35
36 /**
37 * Abstract implementation of a lambda metafactory which provides parameter
38 * unrolling and input validation.
39 *
40 * @see LambdaMetafactory
41 */
42 /* package */ abstract class AbstractValidatingLambdaMetafactory {
43
44 /*
45 * For context, the comments for the following fields are marked in quotes
46 * with their values, given this program:
47 * interface II<T> { Object foo(T x); }
48 * interface JJ<R extends Number> extends II<R> { }
49 * class CC { String impl(int i) { return "impl:"+i; }}
50 * class X {
51 * public static void main(String[] args) {
52 * JJ<Integer> iii = (new CC())::impl;
53 * System.out.printf(">>> %s\n", iii.foo(44));
54 * }}
55 */
56 final MethodHandles.Lookup caller; // The caller's lookup context
57 final Class<?> targetClass; // The class calling the meta-factory via invokedynamic "class X"
58 final MethodType factoryType; // The type of the invoked method "(CC)II"
59 final Class<?> interfaceClass; // The type of the returned instance "interface JJ"
60 final String interfaceMethodName; // Name of the method to implement "foo"
61 final MethodType interfaceMethodType; // Type of the method to implement "(Object)Object"
62 final MethodHandle implementation; // Raw method handle for the implementation method
63 final MethodType implMethodType; // Type of the implementation MethodHandle "(CC,int)String"
64 final MethodHandleInfo implInfo; // Info about the implementation method handle "MethodHandleInfo[5 CC.impl(int)String]"
65 final int implKind; // Invocation kind for implementation "5"=invokevirtual
66 final boolean implIsInstanceMethod; // Is the implementation an instance method "true"
67 final Class<?> implClass; // Class for referencing the implementation method "class CC"
68 final MethodType dynamicMethodType; // Dynamically checked method type "(Integer)Object"
69 final boolean isSerializable; // Should the returned instance be serializable
70 final Class<?>[] altInterfaces; // Additional interfaces to be implemented
71 final MethodType[] altMethods; // Signatures of additional methods to bridge
72 final MethodHandle quotableOpGetter; // A getter method handle that is used to retrieve the
73 // the quotable lambda's associated intermediate representation (can be null).
74 final MethodHandleInfo quotableOpGetterInfo; // Info about the quotable getter method handle (can be null).
75
76 /**
77 * Meta-factory constructor.
78 *
79 * @param caller Stacked automatically by VM; represents a lookup context
80 * with the accessibility privileges of the caller.
81 * @param factoryType Stacked automatically by VM; the signature of the
82 * invoked method, which includes the expected static
83 * type of the returned lambda object, and the static
84 * types of the captured arguments for the lambda. In
85 * the event that the implementation method is an
86 * instance method, the first argument in the invocation
87 * signature will correspond to the receiver.
88 * @param interfaceMethodName Name of the method in the functional interface to
89 * which the lambda or method reference is being
90 * converted, represented as a String.
91 * @param interfaceMethodType Type of the method in the functional interface to
92 * which the lambda or method reference is being
93 * converted, represented as a MethodType.
94 * @param implementation The implementation method which should be called
95 * (with suitable adaptation of argument types, return
96 * types, and adjustment for captured arguments) when
97 * methods of the resulting functional interface instance
98 * are invoked.
99 * @param dynamicMethodType The signature of the primary functional
100 * interface method after type variables are
101 * substituted with their instantiation from
102 * the capture site
103 * @param isSerializable Should the lambda be made serializable? If set,
104 * either the target type or one of the additional SAM
105 * types must extend {@code Serializable}.
106 * @param altInterfaces Additional interfaces which the lambda object
107 * should implement.
108 * @param altMethods Method types for additional signatures to be
109 * implemented by invoking the implementation method
110 * @param reflectiveField a {@linkplain MethodHandles.Lookup#findGetter(Class, String, Class) getter}
111 * method handle that is used to retrieve the string representation of the
112 * quotable lambda's associated intermediate representation.
113 * @throws LambdaConversionException If any of the meta-factory protocol
114 * invariants are violated
115 * @throws SecurityException If a security manager is present, and it
116 * <a href="MethodHandles.Lookup.html#secmgr">denies access</a>
117 * from {@code caller} to the package of {@code implementation}.
118 */
119 AbstractValidatingLambdaMetafactory(MethodHandles.Lookup caller,
120 MethodType factoryType,
121 String interfaceMethodName,
122 MethodType interfaceMethodType,
123 MethodHandle implementation,
124 MethodType dynamicMethodType,
125 boolean isSerializable,
126 Class<?>[] altInterfaces,
127 MethodType[] altMethods,
128 MethodHandle reflectiveField)
129 throws LambdaConversionException {
130 if (!caller.hasFullPrivilegeAccess()) {
131 throw new LambdaConversionException(String.format(
132 "Invalid caller: %s",
133 caller.lookupClass().getName()));
134 }
135 this.caller = caller;
136 this.targetClass = caller.lookupClass();
137 this.factoryType = factoryType;
138
139 this.interfaceClass = factoryType.returnType();
140
141 this.interfaceMethodName = interfaceMethodName;
142 this.interfaceMethodType = interfaceMethodType;
143
144 this.implementation = implementation;
145 this.implMethodType = implementation.type();
146 try {
147 this.implInfo = caller.revealDirect(implementation); // may throw SecurityException
148 } catch (IllegalArgumentException e) {
149 throw new LambdaConversionException(implementation + " is not direct or cannot be cracked");
150 }
151 switch (implInfo.getReferenceKind()) {
152 case REF_invokeVirtual:
153 case REF_invokeInterface:
154 this.implClass = implMethodType.parameterType(0);
155 // reference kind reported by implInfo may not match implMethodType's first param
156 // Example: implMethodType is (Cloneable)String, implInfo is for Object.toString
157 this.implKind = implClass.isInterface() ? REF_invokeInterface : REF_invokeVirtual;
158 this.implIsInstanceMethod = true;
159 break;
160 case REF_invokeSpecial:
161 // JDK-8172817: should use referenced class here, but we don't know what it was
162 this.implClass = implInfo.getDeclaringClass();
163 this.implIsInstanceMethod = true;
164
165 // Classes compiled prior to dynamic nestmate support invoke a private instance
166 // method with REF_invokeSpecial. Newer classes use REF_invokeVirtual or
167 // REF_invokeInterface, and we can use that instruction in the lambda class.
168 if (targetClass == implClass && Modifier.isPrivate(implInfo.getModifiers())) {
169 this.implKind = implClass.isInterface() ? REF_invokeInterface : REF_invokeVirtual;
170 } else {
171 this.implKind = REF_invokeSpecial;
172 }
173 break;
174 case REF_invokeStatic:
175 case REF_newInvokeSpecial:
176 // JDK-8172817: should use referenced class here for invokestatic, but we don't know what it was
177 this.implClass = implInfo.getDeclaringClass();
178 this.implKind = implInfo.getReferenceKind();
179 this.implIsInstanceMethod = false;
180 break;
181 default:
182 throw new LambdaConversionException(String.format("Unsupported MethodHandle kind: %s", implInfo));
183 }
184
185 this.dynamicMethodType = dynamicMethodType;
186 this.isSerializable = isSerializable;
187 this.altInterfaces = altInterfaces;
188 this.altMethods = altMethods;
189 this.quotableOpGetter = reflectiveField;
190
191 if (interfaceMethodName.isEmpty() ||
192 interfaceMethodName.indexOf('.') >= 0 ||
193 interfaceMethodName.indexOf(';') >= 0 ||
194 interfaceMethodName.indexOf('[') >= 0 ||
195 interfaceMethodName.indexOf('/') >= 0 ||
196 interfaceMethodName.indexOf('<') >= 0 ||
197 interfaceMethodName.indexOf('>') >= 0) {
198 throw new LambdaConversionException(String.format(
199 "Method name '%s' is not legal",
200 interfaceMethodName));
201 }
202
203 if (!interfaceClass.isInterface()) {
204 throw new LambdaConversionException(String.format(
205 "%s is not an interface",
206 interfaceClass.getName()));
207 }
208
209 for (Class<?> c : altInterfaces) {
210 if (!c.isInterface()) {
211 throw new LambdaConversionException(String.format(
212 "%s is not an interface",
213 c.getName()));
214 }
215 }
216
217 if (reflectiveField != null) {
218 try {
219 quotableOpGetterInfo = caller.revealDirect(reflectiveField); // may throw SecurityException
220 } catch (IllegalArgumentException e) {
221 throw new LambdaConversionException(implementation + " is not direct or cannot be cracked");
222 }
223 if (quotableOpGetterInfo.getReferenceKind() != REF_invokeStatic) {
224 throw new LambdaConversionException(String.format("Unsupported MethodHandle kind: %s", quotableOpGetterInfo));
225 }
226 } else {
227 quotableOpGetterInfo = null;
228 }
229 }
230
231 /**
232 * Build the CallSite.
233 *
234 * @return a CallSite, which, when invoked, will return an instance of the
235 * functional interface
236 * @throws LambdaConversionException
237 */
238 abstract CallSite buildCallSite()
239 throws LambdaConversionException;
240
241 /**
242 * Check the meta-factory arguments for errors
243 * @throws LambdaConversionException if there are improper conversions
244 */
245 void validateMetafactoryArgs() throws LambdaConversionException {
246 // Check arity: captured + SAM == impl
247 final int implArity = implMethodType.parameterCount();
248 final int capturedArity = factoryType.parameterCount();
249 final int samArity = interfaceMethodType.parameterCount();
250 final int dynamicArity = dynamicMethodType.parameterCount();
251 if (implArity != capturedArity + samArity) {
252 throw new LambdaConversionException(
253 String.format("Incorrect number of parameters for %s method %s; %d captured parameters, %d functional interface method parameters, %d implementation parameters",
254 implIsInstanceMethod ? "instance" : "static", implInfo,
255 capturedArity, samArity, implArity));
256 }
257 if (dynamicArity != samArity) {
258 throw new LambdaConversionException(
259 String.format("Incorrect number of parameters for %s method %s; %d dynamic parameters, %d functional interface method parameters",
260 implIsInstanceMethod ? "instance" : "static", implInfo,
261 dynamicArity, samArity));
262 }
263 for (MethodType bridgeMT : altMethods) {
264 if (bridgeMT.parameterCount() != samArity) {
265 throw new LambdaConversionException(
266 String.format("Incorrect number of parameters for bridge signature %s; incompatible with %s",
267 bridgeMT, interfaceMethodType));
268 }
269 }
270
271 // If instance: first captured arg (receiver) must be subtype of class where impl method is defined
272 final int capturedStart; // index of first non-receiver capture parameter in implMethodType
273 final int samStart; // index of first non-receiver sam parameter in implMethodType
274 if (implIsInstanceMethod) {
275 final Class<?> receiverClass;
276
277 // implementation is an instance method, adjust for receiver in captured variables / SAM arguments
278 if (capturedArity == 0) {
279 // receiver is function parameter
280 capturedStart = 0;
281 samStart = 1;
282 receiverClass = dynamicMethodType.parameterType(0);
283 } else {
284 // receiver is a captured variable
285 capturedStart = 1;
286 samStart = capturedArity;
287 receiverClass = factoryType.parameterType(0);
288 }
289
290 // check receiver type
291 if (!implClass.isAssignableFrom(receiverClass)) {
292 throw new LambdaConversionException(
293 String.format("Invalid receiver type %s; not a subtype of implementation type %s",
294 receiverClass, implClass));
295 }
296 } else {
297 // no receiver
298 capturedStart = 0;
299 samStart = capturedArity;
300 }
301
302 // Check for exact match on non-receiver captured arguments
303 for (int i=capturedStart; i<capturedArity; i++) {
304 Class<?> implParamType = implMethodType.parameterType(i);
305 Class<?> capturedParamType = factoryType.parameterType(i);
306 if (!capturedParamType.equals(implParamType)) {
307 throw new LambdaConversionException(
308 String.format("Type mismatch in captured lambda parameter %d: expecting %s, found %s",
309 i, capturedParamType, implParamType));
310 }
311 }
312 // Check for adaptation match on non-receiver SAM arguments
313 for (int i=samStart; i<implArity; i++) {
314 Class<?> implParamType = implMethodType.parameterType(i);
315 Class<?> dynamicParamType = dynamicMethodType.parameterType(i - capturedArity);
316 if (!isAdaptableTo(dynamicParamType, implParamType, true)) {
317 throw new LambdaConversionException(
318 String.format("Type mismatch for lambda argument %d: %s is not convertible to %s",
319 i, dynamicParamType, implParamType));
320 }
321 }
322
323 // Adaptation match: return type
324 Class<?> expectedType = dynamicMethodType.returnType();
325 Class<?> actualReturnType = implMethodType.returnType();
326 if (!isAdaptableToAsReturn(actualReturnType, expectedType)) {
327 throw new LambdaConversionException(
328 String.format("Type mismatch for lambda return: %s is not convertible to %s",
329 actualReturnType, expectedType));
330 }
331
332 // Check descriptors of generated methods
333 checkDescriptor(interfaceMethodType);
334 for (MethodType bridgeMT : altMethods) {
335 checkDescriptor(bridgeMT);
336 }
337 }
338
339 /** Validate that the given descriptor's types are compatible with {@code dynamicMethodType} **/
340 private void checkDescriptor(MethodType descriptor) throws LambdaConversionException {
341 for (int i = 0; i < dynamicMethodType.parameterCount(); i++) {
342 Class<?> dynamicParamType = dynamicMethodType.parameterType(i);
343 Class<?> descriptorParamType = descriptor.parameterType(i);
344 if (!descriptorParamType.isAssignableFrom(dynamicParamType)) {
345 String msg = String.format("Type mismatch for dynamic parameter %d: %s is not a subtype of %s",
346 i, dynamicParamType, descriptorParamType);
347 throw new LambdaConversionException(msg);
348 }
349 }
350
351 Class<?> dynamicReturnType = dynamicMethodType.returnType();
352 Class<?> descriptorReturnType = descriptor.returnType();
353 if (!isAdaptableToAsReturnStrict(dynamicReturnType, descriptorReturnType)) {
354 String msg = String.format("Type mismatch for lambda expected return: %s is not convertible to %s",
355 dynamicReturnType, descriptorReturnType);
356 throw new LambdaConversionException(msg);
357 }
358 }
359
360 /**
361 * Check type adaptability for parameter types.
362 * @param fromType Type to convert from
363 * @param toType Type to convert to
364 * @param strict If true, do strict checks, else allow that fromType may be parameterized
365 * @return True if 'fromType' can be passed to an argument of 'toType'
366 */
367 private boolean isAdaptableTo(Class<?> fromType, Class<?> toType, boolean strict) {
368 if (fromType.equals(toType)) {
369 return true;
370 }
371 if (fromType.isPrimitive()) {
372 Wrapper wfrom = forPrimitiveType(fromType);
373 if (toType.isPrimitive()) {
374 // both are primitive: widening
375 Wrapper wto = forPrimitiveType(toType);
376 return wto.isConvertibleFrom(wfrom);
377 } else {
378 // from primitive to reference: boxing
379 return toType.isAssignableFrom(wfrom.wrapperType());
380 }
381 } else {
382 if (toType.isPrimitive()) {
383 // from reference to primitive: unboxing
384 Wrapper wfrom;
385 if (isWrapperType(fromType) && (wfrom = forWrapperType(fromType)).primitiveType().isPrimitive()) {
386 // fromType is a primitive wrapper; unbox+widen
387 Wrapper wto = forPrimitiveType(toType);
388 return wto.isConvertibleFrom(wfrom);
389 } else {
390 // must be convertible to primitive
391 return !strict;
392 }
393 } else {
394 // both are reference types: fromType should be a superclass of toType.
395 return !strict || toType.isAssignableFrom(fromType);
396 }
397 }
398 }
399
400 /**
401 * Check type adaptability for return types --
402 * special handling of void type) and parameterized fromType
403 * @return True if 'fromType' can be converted to 'toType'
404 */
405 private boolean isAdaptableToAsReturn(Class<?> fromType, Class<?> toType) {
406 return toType.equals(void.class)
407 || !fromType.equals(void.class) && isAdaptableTo(fromType, toType, false);
408 }
409 private boolean isAdaptableToAsReturnStrict(Class<?> fromType, Class<?> toType) {
410 if (fromType.equals(void.class) || toType.equals(void.class)) return fromType.equals(toType);
411 else return isAdaptableTo(fromType, toType, true);
412 }
413
414
415 /*********** Logging support -- for debugging only, uncomment as needed
416 static final Executor logPool = Executors.newSingleThreadExecutor();
417 protected static void log(final String s) {
418 MethodHandleProxyLambdaMetafactory.logPool.execute(new Runnable() {
419 @Override
420 public void run() {
421 System.out.println(s);
422 }
423 });
424 }
425
426 protected static void log(final String s, final Throwable e) {
427 MethodHandleProxyLambdaMetafactory.logPool.execute(new Runnable() {
428 @Override
429 public void run() {
430 System.out.println(s);
431 e.printStackTrace(System.out);
432 }
433 });
434 }
435 ***********************/
436
437 }