1 /* 2 * Copyright (c) 2012, 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.meta; 24 25 import java.lang.reflect.*; 26 27 /** 28 * Provides access to the metadata of a class typically provided in a class file. 29 */ 30 public interface MetaAccessProvider { 31 32 /** 33 * Returns the resolved Java type representing a given Java class. 34 * 35 * @param clazz the Java class object 36 * @return the resolved Java type object 37 */ 38 ResolvedJavaType lookupJavaType(Class<?> clazz); 39 40 /** 41 * Returns the resolved Java types representing some given Java classes. 42 * 43 * @param classes the Java class objects 44 * @return the resolved Java type objects 45 */ 46 default ResolvedJavaType[] lookupJavaTypes(Class<?>[] classes) { 47 ResolvedJavaType[] result = new ResolvedJavaType[classes.length]; 48 for (int i = 0; i < result.length; i++) { 49 result[i] = lookupJavaType(classes[i]); 50 } 51 return result; 52 } 53 54 /** 55 * Provides the {@link ResolvedJavaMethod} for a {@link Method} or {@link Constructor} obtained 56 * via reflection. 57 */ 58 ResolvedJavaMethod lookupJavaMethod(Executable reflectionMethod); 59 60 /** 61 * Provides the {@link ResolvedJavaField} for a {@link Field} obtained via reflection. 62 */ 63 ResolvedJavaField lookupJavaField(Field reflectionField); 64 65 /** 66 * Returns the resolved Java type of the given {@link JavaConstant} object. 67 * 68 * @return {@code null} if {@code constant.isNull() || !constant.kind.isObject()} 69 */ 70 ResolvedJavaType lookupJavaType(JavaConstant constant); 71 72 /** 73 * Returns the number of bytes occupied by this constant value or constant object. 74 * 75 * @param constant the constant whose bytes should be measured 76 * @return the number of bytes occupied by this constant 77 */ 78 long getMemorySize(JavaConstant constant); 79 80 /** 81 * Parses a <a 82 * href="http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.3.3">method 83 * descriptor</a> into a {@link Signature}. The behavior of this method is undefined if the 84 * method descriptor is not well formed. 85 */ 86 Signature parseMethodDescriptor(String methodDescriptor); 87 88 /** 89 * Encodes a deoptimization action and a deoptimization reason in an integer value. 90 * 91 * @param debugId an integer that can be used to track the origin of a deoptimization at 92 * runtime. There is no guarantee that the runtime will use this value. The runtime 93 * may even keep fewer than 32 bits. 94 * 95 * @return the encoded value as an integer 96 */ 97 JavaConstant encodeDeoptActionAndReason(DeoptimizationAction action, DeoptimizationReason reason, int debugId); 98 99 DeoptimizationReason decodeDeoptReason(JavaConstant constant); 100 101 DeoptimizationAction decodeDeoptAction(JavaConstant constant); 102 103 int decodeDebugId(JavaConstant constant); 104 }