| 1 | /* |
| 2 | * Copyright 2002-2006 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package com.sun.tools.javac.jvm; |
| 27 | |
| 28 | import java.util.*; |
| 29 | |
| 30 | import com.sun.tools.javac.code.Flags; |
| 31 | import com.sun.tools.javac.code.Symbol; |
| 32 | import com.sun.tools.javac.util.*; |
| 33 | |
| 34 | /** The classfile version target. |
| 35 | * |
| 36 | * <p><b>This is NOT part of any API supported by Sun Microsystems. If |
| 37 | * you write code that depends on this, you do so at your own risk. |
| 38 | * This code and its internal interfaces are subject to change or |
| 39 | * deletion without notice.</b> |
| 40 | */ |
| 41 | public enum Target { |
| 42 | JDK1_1("1.1", 45, 3), |
| 43 | JDK1_2("1.2", 46, 0), |
| 44 | JDK1_3("1.3", 47, 0), |
| 45 | |
| 46 | /** J2SE1.4 = Merlin. */ |
| 47 | JDK1_4("1.4", 48, 0), |
| 48 | |
| 49 | /** Support for the JSR14 prototype compiler (targeting 1.4 VMs |
| 50 | * augmented with a few support classes). This is a transitional |
| 51 | * option that will not be supported in the product. */ |
| 52 | JSR14("jsr14", 48, 0), |
| 53 | |
| 54 | /** The following are undocumented transitional targets that we |
| 55 | * had used to test VM fixes in update releases. We do not |
| 56 | * promise to retain support for them. */ |
| 57 | JDK1_4_1("1.4.1", 48, 0), |
| 58 | JDK1_4_2("1.4.2", 48, 0), |
| 59 | |
| 60 | /** Tiger. */ |
| 61 | JDK1_5("1.5", 49, 0), |
| 62 | |
| 63 | /** JDK 6. */ |
| 64 | JDK1_6("1.6", 50, 0), |
| 65 | |
| 66 | /** JDK 7. */ |
| 67 | JDK1_7("1.7", 51, 0); |
| 68 | |
| 69 | private static final Context.Key<Target> targetKey = |
| 70 | new Context.Key<Target>(); |
| 71 | |
| 72 | public static Target instance(Context context) { |
| 73 | Target instance = context.get(targetKey); |
| 74 | if (instance == null) { |
| 75 | Options options = Options.instance(context); |
| 76 | String targetString = options.get("-target"); |
| 77 | if (targetString != null) instance = lookup(targetString); |
| 78 | if (instance == null) instance = DEFAULT; |
| 79 | context.put(targetKey, instance); |
| 80 | } |
| 81 | return instance; |
| 82 | } |
| 83 | |
| 84 | private static Target MIN; |
| 85 | public static Target MIN() { return MIN; } |
| 86 | |
| 87 | private static Target MAX; |
| 88 | public static Target MAX() { return MAX; } |
| 89 | |
| 90 | private static Map<String,Target> tab = new HashMap<String,Target>(); |
| 91 | static { |
| 92 | for (Target t : values()) { |
| 93 | if (MIN == null) MIN = t; |
| 94 | MAX = t; |
| 95 | tab.put(t.name, t); |
| 96 | } |
| 97 | tab.put("5", JDK1_5); |
| 98 | tab.put("6", JDK1_6); |
| 99 | tab.put("7", JDK1_7); |
| 100 | } |
| 101 | |
| 102 | public final String name; |
| 103 | public final int majorVersion; |
| 104 | public final int minorVersion; |
| 105 | private Target(String name, int majorVersion, int minorVersion) { |
| 106 | this.name = name; |
| 107 | this.majorVersion = majorVersion; |
| 108 | this.minorVersion = minorVersion; |
| 109 | } |
| 110 | |
| 111 | public static final Target DEFAULT = JDK1_6; |
| 112 | |
| 113 | public static Target lookup(String name) { |
| 114 | return tab.get(name); |
| 115 | } |
| 116 | |
| 117 | /** In -target 1.1 and earlier, the compiler is required to emit |
| 118 | * synthetic method definitions in abstract classes for interface |
| 119 | * methods that are not overridden. We call them "Miranda" methods. |
| 120 | */ |
| 121 | public boolean requiresIproxy() { |
| 122 | return compareTo(JDK1_1) <= 0; |
| 123 | } |
| 124 | |
| 125 | /** Beginning in 1.4, we take advantage of the possibility of emitting |
| 126 | * code to initialize fields before calling the superclass constructor. |
| 127 | * This is allowed by the VM spec, but the verifier refused to allow |
| 128 | * it until 1.4. This is necesary to translate some code involving |
| 129 | * inner classes. See, for example, 4030374. |
| 130 | */ |
| 131 | public boolean initializeFieldsBeforeSuper() { |
| 132 | return compareTo(JDK1_4) >= 0; |
| 133 | } |
| 134 | |
| 135 | /** Beginning with -target 1.2 we obey the JLS rules for binary |
| 136 | * compatibility, emitting as the qualifying type of a reference |
| 137 | * to a method or field the type of the qualifier. In earlier |
| 138 | * targets we use as the qualifying type the class in which the |
| 139 | * member was found. The following methods named |
| 140 | * *binaryCompatibility() indicate places where we vary from this |
| 141 | * general rule. */ |
| 142 | public boolean obeyBinaryCompatibility() { |
| 143 | return compareTo(JDK1_2) >= 0; |
| 144 | } |
| 145 | |
| 146 | /** Starting in 1.5, the compiler uses an array type as |
| 147 | * the qualifier for method calls (such as clone) where required by |
| 148 | * the language and VM spec. Earlier versions of the compiler |
| 149 | * qualified them by Object. |
| 150 | */ |
| 151 | public boolean arrayBinaryCompatibility() { |
| 152 | return compareTo(JDK1_5) >= 0; |
| 153 | } |
| 154 | |
| 155 | /** Beginning after 1.2, we follow the binary compatibility rules for |
| 156 | * interface fields. The 1.2 VMs had bugs handling interface fields |
| 157 | * when compiled using binary compatibility (see 4400598), so this is |
| 158 | * an accommodation to them. |
| 159 | */ |
| 160 | public boolean interfaceFieldsBinaryCompatibility() { |
| 161 | return compareTo(JDK1_2) > 0; |
| 162 | } |
| 163 | |
| 164 | /** Beginning in -target 1.5, we follow the binary compatibility |
| 165 | * rules for interface methods that redefine Object methods. |
| 166 | * Earlier VMs had bugs handling such methods compiled using binary |
| 167 | * compatibility (see 4392595, 4398791, 4392595, 4400415). |
| 168 | * The VMs were fixed during or soon after 1.4. See 4392595. |
| 169 | */ |
| 170 | public boolean interfaceObjectOverridesBinaryCompatibility() { |
| 171 | return compareTo(JDK1_5) >= 0; |
| 172 | } |
| 173 | |
| 174 | /** Beginning in -target 1.4.2, we make synthetic variables |
| 175 | * package-private instead of private. This is to prevent the |
| 176 | * necessity of access methods, which effectively relax the |
| 177 | * protection of the field but bloat the class files and affect |
| 178 | * execution. |
| 179 | */ |
| 180 | public boolean usePrivateSyntheticFields() { |
| 181 | return compareTo(JDK1_4_2) < 0; |
| 182 | } |
| 183 | |
| 184 | /** Sometimes we need to create a field to cache a value like a |
| 185 | * class literal of the assertions flag. In -target 1.4.2 and |
| 186 | * later we create a new synthetic class for this instead of |
| 187 | * using the outermost class. See 4401576. |
| 188 | */ |
| 189 | public boolean useInnerCacheClass() { |
| 190 | return compareTo(JDK1_4_2) >= 0; |
| 191 | } |
| 192 | |
| 193 | /** Return true if cldc-style stack maps need to be generated. */ |
| 194 | public boolean generateCLDCStackmap() { |
| 195 | return false; |
| 196 | } |
| 197 | |
| 198 | /** Beginning in -target 6, we generate stackmap attribute in |
| 199 | * compact format. */ |
| 200 | public boolean generateStackMapTable() { |
| 201 | return compareTo(JDK1_6) >= 0; |
| 202 | } |
| 203 | |
| 204 | /** Beginning in -target 6, package-info classes are marked synthetic. |
| 205 | */ |
| 206 | public boolean isPackageInfoSynthetic() { |
| 207 | return compareTo(JDK1_6) >= 0; |
| 208 | } |
| 209 | |
| 210 | /** Do we generate "empty" stackmap slots after double and long? |
| 211 | */ |
| 212 | public boolean generateEmptyAfterBig() { |
| 213 | return false; |
| 214 | } |
| 215 | |
| 216 | /** Beginning in 1.5, we have an unsynchronized version of |
| 217 | * StringBuffer called StringBuilder that can be used by the |
| 218 | * compiler for string concatenation. |
| 219 | */ |
| 220 | public boolean useStringBuilder() { |
| 221 | return compareTo(JDK1_5) >= 0; |
| 222 | } |
| 223 | |
| 224 | /** Beginning in 1.5, we have flag bits we can use instead of |
| 225 | * marker attributes. |
| 226 | */ |
| 227 | public boolean useSyntheticFlag() { |
| 228 | return compareTo(JDK1_5) >= 0; |
| 229 | } |
| 230 | public boolean useEnumFlag() { |
| 231 | return compareTo(JDK1_5) >= 0; |
| 232 | } |
| 233 | public boolean useAnnotationFlag() { |
| 234 | return compareTo(JDK1_5) >= 0; |
| 235 | } |
| 236 | public boolean useVarargsFlag() { |
| 237 | return compareTo(JDK1_5) >= 0; |
| 238 | } |
| 239 | public boolean useBridgeFlag() { |
| 240 | return compareTo(JDK1_5) >= 0; |
| 241 | } |
| 242 | |
| 243 | /** Return the character to be used in constructing synthetic |
| 244 | * identifiers, where not specified by the JLS. |
| 245 | */ |
| 246 | public char syntheticNameChar() { |
| 247 | return '$'; |
| 248 | } |
| 249 | |
| 250 | /** Does the VM have direct support for class literals? |
| 251 | */ |
| 252 | public boolean hasClassLiterals() { |
| 253 | return compareTo(JDK1_5) >= 0; |
| 254 | } |
| 255 | |
| 256 | /** Although we may not have support for class literals, should we |
| 257 | * avoid initializing the class that the literal refers to? |
| 258 | * See 4468823 |
| 259 | */ |
| 260 | public boolean classLiteralsNoInit() { |
| 261 | return compareTo(JDK1_4_2) >= 0; |
| 262 | } |
| 263 | |
| 264 | /** Although we may not have support for class literals, when we |
| 265 | * throw a NoClassDefFoundError, should we initialize its cause? |
| 266 | */ |
| 267 | public boolean hasInitCause() { |
| 268 | return compareTo(JDK1_4) >= 0; |
| 269 | } |
| 270 | |
| 271 | /** For bootstrapping, we use J2SE1.4's wrapper class constructors |
| 272 | * to implement boxing. |
| 273 | */ |
| 274 | public boolean boxWithConstructors() { |
| 275 | return compareTo(JDK1_5) < 0; |
| 276 | } |
| 277 | |
| 278 | /** For bootstrapping, we use J2SE1.4's java.util.Collection |
| 279 | * instead of java.lang.Iterable. |
| 280 | */ |
| 281 | public boolean hasIterable() { |
| 282 | return compareTo(JDK1_5) >= 0; |
| 283 | } |
| 284 | |
| 285 | /** For bootstrapping javac only, we do without java.lang.Enum if |
| 286 | * necessary. |
| 287 | */ |
| 288 | public boolean compilerBootstrap(Symbol c) { |
| 289 | return |
| 290 | this == JSR14 && |
| 291 | (c.flags() & Flags.ENUM) != 0 && |
| 292 | c.flatName().toString().startsWith("com.sun.tools.") |
| 293 | // && !Target.class.getSuperclass().getName().equals("java.lang.Enum") |
| 294 | ; |
| 295 | } |
| 296 | |
| 297 | /** In J2SE1.5.0, we introduced the "EnclosingMethod" attribute |
| 298 | * for improved reflection support. |
| 299 | */ |
| 300 | public boolean hasEnclosingMethodAttribute() { |
| 301 | return compareTo(JDK1_5) >= 0 || this == JSR14; |
| 302 | } |
| 303 | } |