1 /* 2 * Copyright (c) 2012, 2019, 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.Constructor; 26 import java.lang.reflect.Executable; 27 import java.lang.reflect.Field; 28 import java.lang.reflect.Method; 29 30 import jdk.vm.ci.meta.SpeculationLog.Speculation; 31 32 /** 33 * Provides access to the metadata of a class typically provided in a class file. 34 */ 35 public interface MetaAccessProvider { 36 37 /** 38 * Returns the resolved Java type representing a given Java class. 39 * 40 * @param clazz the Java class object 41 * @return the resolved Java type object 42 */ 43 ResolvedJavaType lookupJavaType(Class<?> clazz); 44 45 /** 46 * Returns the resolved Java types representing some given Java classes. 47 * 48 * @param classes the Java class objects 49 * @return the resolved Java type objects 50 */ 51 default ResolvedJavaType[] lookupJavaTypes(Class<?>[] classes) { 52 ResolvedJavaType[] result = new ResolvedJavaType[classes.length]; 53 for (int i = 0; i < result.length; i++) { 54 result[i] = lookupJavaType(classes[i]); 55 } 56 return result; 57 } 58 59 /** 60 * Provides the {@link ResolvedJavaMethod} for a {@link Method} or {@link Constructor} obtained 61 * via reflection. 62 */ 63 ResolvedJavaMethod lookupJavaMethod(Executable reflectionMethod); 64 65 /** 66 * Provides the {@link ResolvedJavaField} for a {@link Field} obtained via reflection. 67 */ 68 ResolvedJavaField lookupJavaField(Field reflectionField); 69 70 /** 71 * Returns the resolved Java type of the given {@link JavaConstant} object. 72 * 73 * @return {@code null} if {@code constant.isNull() || !constant.kind.isObject()} 74 */ 75 ResolvedJavaType lookupJavaType(JavaConstant constant); 76 77 /** 78 * Returns the number of bytes occupied by this constant value or constant object. 79 * 80 * @param constant the constant whose bytes should be measured 81 * @return the number of bytes occupied by this constant 82 */ 83 long getMemorySize(JavaConstant constant); 84 85 /** 86 * Parses a 87 * <a href="http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.3.3">method 88 * descriptor</a> into a {@link Signature}. 89 * 90 * @throws IllegalArgumentException if the method descriptor is not well formed 91 */ 92 Signature parseMethodDescriptor(String methodDescriptor); 93 94 /** 95 * Encodes a deoptimization action and a deoptimization reason in an integer value. 96 * 97 * @param debugId an integer that can be used to track the origin of a deoptimization at 98 * runtime. There is no guarantee that the runtime will use this value. The runtime 99 * may even keep fewer than 32 bits. 100 * 101 * @return the encoded value as an integer 102 */ 103 JavaConstant encodeDeoptActionAndReason(DeoptimizationAction action, DeoptimizationReason reason, int debugId); 104 105 /** 106 * Gets a constant that denotes {@code speculation}. The constant can passed to the 107 * deoptimization handler (e.g., through a thread local) to indicate a failed speculation. 108 */ 109 JavaConstant encodeSpeculation(Speculation speculation); 110 111 /** 112 * Decodes {@code constant} back to a {@link Speculation} object. 113 * 114 * @throws IllegalArgumentException if {@code constant} can only be decoded through a 115 * {@link SpeculationLog} and {@code speculationLog} does not contain the 116 * speculation denoted by {@code constant} 117 */ 118 Speculation decodeSpeculation(JavaConstant constant, SpeculationLog speculationLog); 119 120 DeoptimizationReason decodeDeoptReason(JavaConstant constant); 121 122 DeoptimizationAction decodeDeoptAction(JavaConstant constant); 123 124 int decodeDebugId(JavaConstant constant); 125 126 int getArrayBaseOffset(JavaKind elementKind); 127 128 int getArrayIndexScale(JavaKind elementKind); 129 }