OptionKey.java revision 12968:4d8a004e5c6d
1/* 2 * Copyright (c) 2013, 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 */ 23package org.graalvm.compiler.options; 24 25import java.util.Formatter; 26 27import org.graalvm.util.EconomicMap; 28 29/** 30 * A key for an option. The value for an option is obtained from an {@link OptionValues} object. 31 */ 32public class OptionKey<T> { 33 34 private final T defaultValue; 35 36 private OptionDescriptor descriptor; 37 38 public OptionKey(T defaultValue) { 39 this.defaultValue = defaultValue; 40 } 41 42 /** 43 * Sets the descriptor for this option. 44 */ 45 public final void setDescriptor(OptionDescriptor descriptor) { 46 assert this.descriptor == null : "Overwriting existing descriptor"; 47 this.descriptor = descriptor; 48 } 49 50 /** 51 * Returns the descriptor for this option, if it has been set by 52 * {@link #setDescriptor(OptionDescriptor)}. 53 */ 54 public final OptionDescriptor getDescriptor() { 55 return descriptor; 56 } 57 58 /** 59 * Checks that a descriptor exists for this key after triggering loading of descriptors. 60 */ 61 protected boolean checkDescriptorExists() { 62 OptionKey.Lazy.init(); 63 if (descriptor == null) { 64 Formatter buf = new Formatter(); 65 buf.format("Could not find a descriptor for an option key. The most likely cause is " + 66 "a dependency on the %s annotation without a dependency on the " + 67 "org.graalvm.compiler.options.processor.OptionProcessor annotation processor.", Option.class.getName()); 68 StackTraceElement[] stackTrace = new Exception().getStackTrace(); 69 if (stackTrace.length > 2 && 70 stackTrace[1].getClassName().equals(OptionKey.class.getName()) && 71 stackTrace[1].getMethodName().equals("getValue")) { 72 String caller = stackTrace[2].getClassName(); 73 buf.format(" In suite.py, add GRAAL_OPTIONS_PROCESSOR to the \"annotationProcessors\" attribute of the project " + 74 "containing %s.", caller); 75 } 76 throw new AssertionError(buf.toString()); 77 } 78 return true; 79 } 80 81 /** 82 * Mechanism for lazily loading all available options which has the side effect of assigning 83 * names to the options. 84 */ 85 static class Lazy { 86 static { 87 for (OptionDescriptors opts : OptionsParser.getOptionsLoader()) { 88 for (OptionDescriptor desc : opts) { 89 desc.getName(); 90 } 91 } 92 } 93 94 static void init() { 95 /* Running the static class initializer does all the initialization. */ 96 } 97 } 98 99 /** 100 * Gets the name of this option. The name for an option value with a null 101 * {@linkplain #setDescriptor(OptionDescriptor) descriptor} is the value of 102 * {@link Object#toString()}. 103 */ 104 public final String getName() { 105 if (descriptor == null) { 106 // Trigger initialization of OptionsLoader to ensure all option values have 107 // a descriptor which is required for them to have meaningful names. 108 Lazy.init(); 109 } 110 return descriptor == null ? super.toString() : descriptor.getName(); 111 } 112 113 @Override 114 public String toString() { 115 return getName(); 116 } 117 118 /** 119 * The initial value specified in source code. 120 */ 121 public final T getDefaultValue() { 122 return defaultValue; 123 } 124 125 /** 126 * Returns true if the option has been set in any way. Note that this doesn't mean that the 127 * current value is different than the default. 128 */ 129 public boolean hasBeenSet(OptionValues values) { 130 return values.containsKey(this); 131 } 132 133 /** 134 * Gets the value of this option in {@code values}. 135 */ 136 public T getValue(OptionValues values) { 137 assert checkDescriptorExists(); 138 return values.get(this); 139 } 140 141 /** 142 * Sets the value of this option in a given map. The 143 * {@link #onValueUpdate(EconomicMap, Object, Object)} method is called once the value is set. 144 * 145 * @param values map of option values 146 * @param v the value to set for this key in {@code map} 147 */ 148 @SuppressWarnings("unchecked") 149 public void update(EconomicMap<OptionKey<?>, Object> values, Object v) { 150 T oldValue = (T) values.put(this, v); 151 onValueUpdate(values, oldValue, (T) v); 152 } 153 154 /** 155 * Notifies this object when a value associated with this key is set or updated in 156 * {@code values}. 157 * 158 * @param values 159 * @param oldValue 160 * @param newValue 161 */ 162 protected void onValueUpdate(EconomicMap<OptionKey<?>, Object> values, T oldValue, T newValue) { 163 } 164} 165