1 /*
2 * Copyright (c) 2014, 2014, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23 package jdk.vm.ci.hotspot;
24
25 import static jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.*;
26 import static jdk.vm.ci.hotspot.HotSpotResolvedObjectTypeImpl.*;
27
28 import jdk.vm.ci.common.*;
29 import jdk.vm.ci.meta.*;
30
31 public class HotSpotMethodHandleAccessProvider implements MethodHandleAccessProvider, HotSpotProxified {
32
33 private final ConstantReflectionProvider constantReflection;
34
35 public HotSpotMethodHandleAccessProvider(ConstantReflectionProvider constantReflection) {
36 this.constantReflection = constantReflection;
37 }
38
39 /**
40 * Lazy initialization to break class initialization cycle. Field and method lookup is only
41 * possible after the {@link HotSpotJVMCIRuntime} is fully initialized.
42 */
43 static class LazyInitialization {
44 static final ResolvedJavaField methodHandleFormField;
45 static final ResolvedJavaField lambdaFormVmentryField;
46 static final ResolvedJavaMethod lambdaFormCompileToBytecodeMethod;
47 static final HotSpotResolvedJavaField memberNameVmtargetField;
48
49 /**
50 * Search for an instance field with the given name in a class.
51 *
52 * @param className name of the class to search in
53 * @param fieldName name of the field to be searched
54 * @return resolved java field
55 * @throws ClassNotFoundException
56 */
57 private static ResolvedJavaField findFieldInClass(String className, String fieldName) throws ClassNotFoundException {
58 Class<?> clazz = Class.forName(className);
59 ResolvedJavaType type = runtime().fromClass(clazz);
60 ResolvedJavaField[] fields = type.getInstanceFields(false);
61 for (ResolvedJavaField field : fields) {
62 if (field.getName().equals(fieldName)) {
63 return field;
64 }
65 }
66 return null;
67 }
68
69 private static ResolvedJavaMethod findMethodInClass(String className, String methodName) throws ClassNotFoundException {
70 Class<?> clazz = Class.forName(className);
71 HotSpotResolvedObjectTypeImpl type = fromObjectClass(clazz);
72 ResolvedJavaMethod result = null;
73 for (ResolvedJavaMethod method : type.getDeclaredMethods()) {
74 if (method.getName().equals(methodName)) {
75 assert result == null : "more than one method found: " + className + "." + methodName;
76 result = method;
77 }
78 }
79 assert result != null : "method not found: " + className + "." + methodName;
80 return result;
81 }
82
83 static {
84 try {
85 methodHandleFormField = findFieldInClass("java.lang.invoke.MethodHandle", "form");
86 lambdaFormVmentryField = findFieldInClass("java.lang.invoke.LambdaForm", "vmentry");
87 lambdaFormCompileToBytecodeMethod = findMethodInClass("java.lang.invoke.LambdaForm", "compileToBytecode");
88 memberNameVmtargetField = (HotSpotResolvedJavaField) findFieldInClass("java.lang.invoke.MemberName", "vmtarget");
89 } catch (Throwable ex) {
90 throw new JVMCIError(ex);
91 }
92 }
93 }
94
95 @Override
96 public IntrinsicMethod lookupMethodHandleIntrinsic(ResolvedJavaMethod method) {
97 int intrinsicId = ((HotSpotResolvedJavaMethodImpl) method).intrinsicId();
98 if (intrinsicId != 0) {
99 return getMethodHandleIntrinsic(intrinsicId);
100 }
101 return null;
102 }
103
104 public static IntrinsicMethod getMethodHandleIntrinsic(int intrinsicId) {
105 HotSpotVMConfig config = runtime().getConfig();
106 if (intrinsicId == config.vmIntrinsicInvokeBasic) {
107 return IntrinsicMethod.INVOKE_BASIC;
108 } else if (intrinsicId == config.vmIntrinsicLinkToInterface) {
109 return IntrinsicMethod.LINK_TO_INTERFACE;
110 } else if (intrinsicId == config.vmIntrinsicLinkToSpecial) {
111 return IntrinsicMethod.LINK_TO_SPECIAL;
112 } else if (intrinsicId == config.vmIntrinsicLinkToStatic) {
113 return IntrinsicMethod.LINK_TO_STATIC;
114 } else if (intrinsicId == config.vmIntrinsicLinkToVirtual) {
115 return IntrinsicMethod.LINK_TO_VIRTUAL;
116 }
117 return null;
118 }
119
120 @Override
121 public ResolvedJavaMethod resolveInvokeBasicTarget(JavaConstant methodHandle, boolean forceBytecodeGeneration) {
122 if (methodHandle.isNull()) {
123 return null;
124 }
125
126 /* Load non-public field: LambdaForm MethodHandle.form */
127 JavaConstant lambdaForm = constantReflection.readFieldValue(LazyInitialization.methodHandleFormField, methodHandle);
128 if (lambdaForm.isNull()) {
129 return null;
130 }
131
132 JavaConstant memberName;
133 if (forceBytecodeGeneration) {
134 /* Invoke non-public method: MemberName LambdaForm.compileToBytecode() */
135 memberName = LazyInitialization.lambdaFormCompileToBytecodeMethod.invoke(lambdaForm, new JavaConstant[0]);
136 } else {
137 /* Load non-public field: MemberName LambdaForm.vmentry */
138 memberName = constantReflection.readFieldValue(LazyInitialization.lambdaFormVmentryField, lambdaForm);
139 }
140 return getTargetMethod(memberName);
141 }
142
143 @Override
144 public ResolvedJavaMethod resolveLinkToTarget(JavaConstant memberName) {
145 return getTargetMethod(memberName);
146 }
147
148 /**
149 * Returns the {@link ResolvedJavaMethod} for the vmtarget of a java.lang.invoke.MemberName.
150 */
151 private static ResolvedJavaMethod getTargetMethod(JavaConstant memberName) {
152 if (memberName.isNull()) {
153 return null;
154 }
155
156 Object object = ((HotSpotObjectConstantImpl) memberName).object();
157 /* Read the ResolvedJavaMethod from the injected field MemberName.vmtarget */
158 return runtime().compilerToVm.getResolvedJavaMethod(object, LazyInitialization.memberNameVmtargetField.offset());
159 }
160 }