1 /*
2 * Copyright (c) 2014, 2016, 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.CompilerToVM.compilerToVM;
26 import static jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.runtime;
27
28 import java.lang.invoke.MethodHandle;
29 import java.util.Objects;
30
31 import jdk.vm.ci.common.JVMCIError;
32 import jdk.vm.ci.meta.ConstantReflectionProvider;
33 import jdk.vm.ci.meta.JavaConstant;
34 import jdk.vm.ci.meta.MethodHandleAccessProvider;
35 import jdk.vm.ci.meta.ResolvedJavaField;
36 import jdk.vm.ci.meta.ResolvedJavaMethod;
37 import jdk.vm.ci.meta.ResolvedJavaType;
38
39 public class HotSpotMethodHandleAccessProvider implements MethodHandleAccessProvider {
40
41 private final ConstantReflectionProvider constantReflection;
42
43 public HotSpotMethodHandleAccessProvider(ConstantReflectionProvider constantReflection) {
44 this.constantReflection = constantReflection;
45 }
46
47 /**
48 * Lazy initialization to break class initialization cycle. Field and method lookup is only
49 * possible after the {@link HotSpotJVMCIRuntime} is fully initialized.
50 */
51 static class LazyInitialization {
52 static final ResolvedJavaType lambdaFormType;
53 static final ResolvedJavaField methodHandleFormField;
54 static final ResolvedJavaField lambdaFormVmentryField;
55 static final HotSpotResolvedJavaField memberNameVmtargetField;
56
57 /**
58 * Search for an instance field with the given name in a class.
59 *
60 * @param declaringType the type declaring the field
61 * @param fieldName name of the field to be searched
62 * @param fieldType resolved Java type of the field
63 * @return resolved Java field
64 * @throws NoSuchFieldError
65 */
66 private static ResolvedJavaField findFieldInClass(ResolvedJavaType declaringType, String fieldName, ResolvedJavaType fieldType) {
67 ResolvedJavaField[] fields = declaringType.getInstanceFields(false);
68 for (ResolvedJavaField field : fields) {
69 if (field.getName().equals(fieldName) && field.getType().equals(fieldType)) {
70 return field;
71 }
72 }
73 throw new NoSuchFieldError(fieldType.getName() + " " + declaringType + "." + fieldName);
74 }
75
76 private static ResolvedJavaType resolveType(Class<?> c) {
77 return runtime().fromClass(c);
78 }
79
80 private static ResolvedJavaType resolveType(String className) throws ClassNotFoundException {
81 return resolveType(Class.forName(className));
82 }
83
84 static {
85 try {
86 ResolvedJavaType methodHandleType = resolveType(MethodHandle.class);
87 ResolvedJavaType memberNameType = resolveType("java.lang.invoke.MemberName");
88 lambdaFormType = resolveType("java.lang.invoke.LambdaForm");
89 methodHandleFormField = findFieldInClass(methodHandleType, "form", lambdaFormType);
90 lambdaFormVmentryField = findFieldInClass(lambdaFormType, "vmentry", memberNameType);
91 memberNameVmtargetField = (HotSpotResolvedJavaField) findFieldInClass(memberNameType, "vmtarget", resolveType(long.class));
92 } catch (Throwable ex) {
93 throw new JVMCIError(ex);
94 }
95 }
96 }
97
98 @Override
99 public IntrinsicMethod lookupMethodHandleIntrinsic(ResolvedJavaMethod method) {
100 int intrinsicId = ((HotSpotResolvedJavaMethodImpl) method).intrinsicId();
101 if (intrinsicId != 0) {
102 return getMethodHandleIntrinsic(intrinsicId);
103 }
104 return null;
105 }
106
107 public static IntrinsicMethod getMethodHandleIntrinsic(int intrinsicId) {
108 HotSpotVMConfig config = runtime().getConfig();
109 if (intrinsicId == config.vmIntrinsicInvokeBasic) {
110 return IntrinsicMethod.INVOKE_BASIC;
111 } else if (intrinsicId == config.vmIntrinsicLinkToInterface) {
112 return IntrinsicMethod.LINK_TO_INTERFACE;
113 } else if (intrinsicId == config.vmIntrinsicLinkToSpecial) {
114 return IntrinsicMethod.LINK_TO_SPECIAL;
115 } else if (intrinsicId == config.vmIntrinsicLinkToStatic) {
116 return IntrinsicMethod.LINK_TO_STATIC;
117 } else if (intrinsicId == config.vmIntrinsicLinkToVirtual) {
118 return IntrinsicMethod.LINK_TO_VIRTUAL;
119 }
120 return null;
121 }
122
123 @Override
124 public ResolvedJavaMethod resolveInvokeBasicTarget(JavaConstant methodHandle, boolean forceBytecodeGeneration) {
125 if (methodHandle.isNull()) {
126 return null;
127 }
128
129 /* Load non-public field: LambdaForm MethodHandle.form */
130 JavaConstant lambdaForm = constantReflection.readFieldValue(LazyInitialization.methodHandleFormField, methodHandle);
131 if (lambdaForm == null || lambdaForm.isNull()) {
132 return null;
133 }
134
135 JavaConstant memberName = constantReflection.readFieldValue(LazyInitialization.lambdaFormVmentryField, lambdaForm);
136 if (memberName.isNull() && forceBytecodeGeneration) {
137 Object lf = ((HotSpotObjectConstant) lambdaForm).asObject(LazyInitialization.lambdaFormType);
138 compilerToVM().compileToBytecode(Objects.requireNonNull(lf));
139 memberName = constantReflection.readFieldValue(LazyInitialization.lambdaFormVmentryField, lambdaForm);
140 assert memberName.isNonNull();
141 }
142 /* Load non-public field: MemberName LambdaForm.vmentry */
143 return getTargetMethod(memberName);
144 }
145
146 @Override
147 public ResolvedJavaMethod resolveLinkToTarget(JavaConstant memberName) {
148 return getTargetMethod(memberName);
149 }
150
151 /**
152 * Returns the {@link ResolvedJavaMethod} for the vmtarget of a java.lang.invoke.MemberName.
153 */
154 private static ResolvedJavaMethod getTargetMethod(JavaConstant memberName) {
155 if (memberName.isNull()) {
156 return null;
157 }
158
159 Object object = ((HotSpotObjectConstantImpl) memberName).object();
160 /* Read the ResolvedJavaMethod from the injected field MemberName.vmtarget */
161 return compilerToVM().getResolvedJavaMethod(object, LazyInitialization.memberNameVmtargetField.offset());
162 }
163 }