| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.impl.services.bytecode.BCClass |
| 4 | |
| 5 | Copyright 1997, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.impl.services.bytecode; |
| 22 | |
| 23 | import org.apache.derby.iapi.services.compiler.ClassBuilder; |
| 24 | import org.apache.derby.iapi.services.compiler.MethodBuilder; |
| 25 | import org.apache.derby.iapi.services.compiler.LocalField; |
| 26 | |
| 27 | import org.apache.derby.iapi.services.classfile.ClassHolder; |
| 28 | import org.apache.derby.iapi.services.classfile.ClassMember; |
| 29 | import org.apache.derby.iapi.services.classfile.ClassFormatOutput; |
| 30 | import org.apache.derby.iapi.services.loader.ClassFactory; |
| 31 | |
| 32 | import org.apache.derby.iapi.services.monitor.Monitor; |
| 33 | |
| 34 | import org.apache.derby.iapi.error.StandardException; |
| 35 | import org.apache.derby.iapi.reference.Property; |
| 36 | import org.apache.derby.iapi.reference.SQLState; |
| 37 | |
| 38 | import org.apache.derby.iapi.util.ByteArray; |
| 39 | import org.apache.derby.iapi.services.classfile.VMOpcode; |
| 40 | |
| 41 | import java.lang.reflect.Modifier; |
| 42 | |
| 43 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 44 | import org.apache.derby.iapi.services.classfile.VMDescriptor; |
| 45 | |
| 46 | import org.apache.derby.impl.services.bytecode.GClass; |
| 47 | |
| 48 | import java.io.IOException; |
| 49 | |
| 50 | /** |
| 51 | * ClassBuilder is used to construct a java class's byte array |
| 52 | * representation. |
| 53 | * |
| 54 | * Limitations: |
| 55 | * No checking for language use violations such as invalid modifiers |
| 56 | * or duplicate field names. |
| 57 | * All classes must have a superclass; java.lang.Object must be |
| 58 | * supplied if there is no superclass. |
| 59 | * |
| 60 | * <p> |
| 61 | * When a class is first created, it has: |
| 62 | * <ul> |
| 63 | * <li> a superclass |
| 64 | * <li> modifiers |
| 65 | * <li> a name |
| 66 | * <li> a package |
| 67 | * <li> no superinterfaces, methods, fields, or constructors |
| 68 | * <li> an empty static initializer |
| 69 | * <li> an empty initializer |
| 70 | * </ul> |
| 71 | * <p> |
| 72 | * MethodBuilder implementations are required to supply a way for |
| 73 | * Generators to give them code. Most typically, they may have |
| 74 | * a stream to which the Generator writes the code that is of |
| 75 | * the type to satisfy what the Generator is writing. |
| 76 | * <p> |
| 77 | * BCClass is a ClassBuilder implementation for generating java bytecode |
| 78 | * directly. |
| 79 | * |
| 80 | */ |
| 81 | class BCClass extends GClass { |
| 82 | |
| 83 | /** |
| 84 | * Simple text indicating any limits execeeded while generating |
| 85 | * the class file. |
| 86 | */ |
| 87 | String limitMsg; |
| 88 | |
| 89 | // |
| 90 | // ClassBuilder interface |
| 91 | // |
| 92 | /** |
| 93 | * add a field to this class. Fields cannot |
| 94 | * be initialized here, they must be initialized |
| 95 | * in the static initializer code (static fields) |
| 96 | * or in the constructors. |
| 97 | * <p> |
| 98 | * static fields also added to this list, |
| 99 | * with the modifier set appropriately. |
| 100 | */ |
| 101 | public LocalField addField(String javaType, String name, int modifiers) { |
| 102 | |
| 103 | Type type = factory.type(javaType); |
| 104 | // put it into the class holder right away. |
| 105 | ClassMember field = classHold.addMember(name, type.vmName(), modifiers); |
| 106 | int cpi = classHold.addFieldReference(field); |
| 107 | |
| 108 | return new BCLocalField(type, cpi); |
| 109 | } |
| 110 | |
| 111 | /** |
| 112 | * At the time the class is completed and bytecode |
| 113 | * generated, if there are no constructors then |
| 114 | * the default no-arg constructor will be defined. |
| 115 | */ |
| 116 | public ByteArray getClassBytecode() throws StandardException { |
| 117 | |
| 118 | // return if already done |
| 119 | if (bytecode != null) return bytecode; |
| 120 | |
| 121 | try { |
| 122 | |
| 123 | if (SanityManager.DEBUG) { |
| 124 | if (SanityManager.DEBUG_ON("ClassLineNumbers")) { |
| 125 | |
| 126 | ClassFormatOutput sout = new ClassFormatOutput(2); |
| 127 | |
| 128 | int cpiUTF = classHold.addUtf8("GC.java"); |
| 129 | |
| 130 | sout.putU2(cpiUTF); |
| 131 | |
| 132 | classHold.addAttribute("SourceFile", sout); |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | // the class is now complete, get its bytecode. |
| 137 | bytecode = classHold.getFileFormat(); |
| 138 | |
| 139 | } catch (IOException ioe) { |
| 140 | throw StandardException.newException( |
| 141 | SQLState.GENERATED_CLASS_LINKAGE_ERROR, ioe, getFullName()); |
| 142 | } |
| 143 | |
| 144 | // release resources, we have the code now. |
| 145 | // name is not released, it may still be accessed. |
| 146 | classHold = null; |
| 147 | |
| 148 | if (SanityManager.DEBUG) { |
| 149 | if (SanityManager.DEBUG_ON("DumpClassFile")) { |
| 150 | /* Dump the file in derby.system.home */ |
| 151 | String systemHome = System.getProperty(Property.SYSTEM_HOME_PROPERTY,"."); |
| 152 | writeClassFile(systemHome,false,null); |
| 153 | } |
| 154 | } |
| 155 | |
| 156 | if (SanityManager.DEBUG) { |
| 157 | if (SanityManager.DEBUG_ON("ByteCodeGenInstr")) { |
| 158 | SanityManager.DEBUG("ByteCodeGenInstr", |
| 159 | "GEN complete for class "+name); |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | if (limitMsg != null) |
| 164 | throw StandardException.newException( |
| 165 | SQLState.GENERATED_CLASS_LIMIT_EXCEEDED, getFullName(), limitMsg); |
| 166 | return bytecode; |
| 167 | } |
| 168 | |
| 169 | |
| 170 | /** |
| 171 | * the class's unqualified name |
| 172 | */ |
| 173 | public String getName() { |
| 174 | return name; |
| 175 | } |
| 176 | |
| 177 | /** |
| 178 | * a method. Once it is created, thrown |
| 179 | * exceptions, statements, and local variable declarations |
| 180 | * must be added to it. It is put into its defining class |
| 181 | * when it is created. |
| 182 | * <verbatim> |
| 183 | Java: #modifiers #returnType #methodName() {} |
| 184 | // modifiers is the | of the JVM constants for |
| 185 | // the modifiers such as static, public, etc. |
| 186 | </verbatim> |
| 187 | * <p> |
| 188 | * This is used to start a constructor as well; pass in |
| 189 | * null for the returnType when used in that manner. |
| 190 | * |
| 191 | * See java.lang.reflect.Modifiers |
| 192 | * @param modifiers the | of the Modifiers |
| 193 | * constants representing the visibility and control of this |
| 194 | * method. |
| 195 | * @param returnType the return type of the method as its |
| 196 | * Java language type name. |
| 197 | * @param methodName the name of the method. |
| 198 | * |
| 199 | * @return the method builder. |
| 200 | */ |
| 201 | public MethodBuilder newMethodBuilder(int modifiers, String returnType, |
| 202 | String methodName) { |
| 203 | |
| 204 | return newMethodBuilder(modifiers, returnType, |
| 205 | methodName, (String[]) null); |
| 206 | |
| 207 | } |
| 208 | |
| 209 | |
| 210 | /** |
| 211 | * a method with parameters. Once it is created, thrown |
| 212 | * exceptions, statements, and local variable declarations |
| 213 | * must be added to it. It is put into its defining class |
| 214 | * when it is created. |
| 215 | * <verbatim> |
| 216 | Java: #modifiers #returnType #methodName() {} |
| 217 | // modifiers is the | of the JVM constants for |
| 218 | // the modifiers such as static, public, etc. |
| 219 | </verbatim> |
| 220 | * <p> |
| 221 | * This is used to start a constructor as well; pass in |
| 222 | * null for the returnType when used in that manner. |
| 223 | * |
| 224 | * See java.lang.reflect.Modifiers |
| 225 | * @param modifiers the | of the Modifiers |
| 226 | * constants representing the visibility and control of this |
| 227 | * method. |
| 228 | * @param returnType the return type of the method as its |
| 229 | * Java language type name. |
| 230 | * @param methodName the name of the method. |
| 231 | * @param parms an array of ParameterDeclarations representing the |
| 232 | * method's parameters |
| 233 | * |
| 234 | * @return the method builder. |
| 235 | */ |
| 236 | public MethodBuilder newMethodBuilder(int modifiers, String returnType, |
| 237 | String methodName, String[] parms) { |
| 238 | |
| 239 | if (SanityManager.DEBUG) { |
| 240 | SanityManager.ASSERT(returnType!=null); |
| 241 | } |
| 242 | |
| 243 | BCMethod m = new BCMethod(this, |
| 244 | returnType, |
| 245 | methodName, |
| 246 | modifiers, |
| 247 | parms, |
| 248 | factory); |
| 249 | |
| 250 | return m; |
| 251 | |
| 252 | } |
| 253 | |
| 254 | |
| 255 | /** |
| 256 | * a constructor. Once it is created, thrown |
| 257 | * exceptions, statements, and local variable declarations |
| 258 | * must be added to it. It is put into its defining class |
| 259 | * when it is created. |
| 260 | * <verbatim> |
| 261 | Java: #modifiers #className() {} |
| 262 | // modifiers is the | of the JVM constants for |
| 263 | // the modifiers such as static, public, etc. |
| 264 | // className is taken from definingClass.getName() |
| 265 | </verbatim> |
| 266 | * <p> |
| 267 | * This is used to start a constructor as well; pass in |
| 268 | * null for the returnType when used in that manner. |
| 269 | * |
| 270 | * See Modifiers |
| 271 | * @param modifiers the | of the Modifiers |
| 272 | * constants representing the visibility and control of this |
| 273 | * method. |
| 274 | * |
| 275 | * @return the method builder for the constructor. |
| 276 | */ |
| 277 | public MethodBuilder newConstructorBuilder(int modifiers) { |
| 278 | |
| 279 | BCMethod m = new BCMethod(this, "void", "<init>", |
| 280 | modifiers, |
| 281 | (String []) null, |
| 282 | factory); |
| 283 | |
| 284 | return m; |
| 285 | } |
| 286 | // |
| 287 | // class interface |
| 288 | // |
| 289 | |
| 290 | String getSuperClassName() { |
| 291 | return superClassName; |
| 292 | } |
| 293 | |
| 294 | /** |
| 295 | * Let those that need to get to the |
| 296 | * classModify tool to alter the class definition. |
| 297 | */ |
| 298 | ClassHolder modify() { |
| 299 | return classHold; |
| 300 | } |
| 301 | |
| 302 | /* |
| 303 | ** Method descriptor caching |
| 304 | */ |
| 305 | |
| 306 | BCClass(ClassFactory cf, String packageName, int classModifiers, |
| 307 | String className, String superClassName, |
| 308 | BCJava factory) { |
| 309 | |
| 310 | super(cf, packageName.concat(className)); |
| 311 | |
| 312 | if (SanityManager.DEBUG) { |
| 313 | if (SanityManager.DEBUG_ON("ByteCodeGenInstr")) { |
| 314 | SanityManager.DEBUG("ByteCodeGenInstr", |
| 315 | "GEN starting for class "+className); |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | // by the time the constructor is done, we have: |
| 320 | // |
| 321 | // package #packageName; |
| 322 | // #classModifiers class #className extends #superClassName |
| 323 | // { } |
| 324 | // |
| 325 | |
| 326 | name = className; |
| 327 | if (superClassName == null) |
| 328 | superClassName = "java.lang.Object"; |
| 329 | this.superClassName = superClassName; |
| 330 | |
| 331 | classType = factory.type(getFullName()); |
| 332 | |
| 333 | classHold = new ClassHolder(qualifiedName, factory.type(superClassName).vmNameSimple, classModifiers); |
| 334 | |
| 335 | this.factory = factory; |
| 336 | } |
| 337 | |
| 338 | protected ClassHolder classHold; |
| 339 | |
| 340 | protected String superClassName; |
| 341 | protected String name; |
| 342 | |
| 343 | BCJava factory; |
| 344 | final Type classType; |
| 345 | |
| 346 | ClassFactory getClassFactory() { |
| 347 | return cf; |
| 348 | } |
| 349 | |
| 350 | public void newFieldWithAccessors(String getter, String setter, |
| 351 | int methodModifers, |
| 352 | boolean staticField, String type) { |
| 353 | |
| 354 | String vmType = factory.type(type).vmName(); |
| 355 | methodModifers |= Modifier.FINAL; |
| 356 | |
| 357 | |
| 358 | // add a field, field has same name as get method |
| 359 | int fieldModifiers = Modifier.PRIVATE; |
| 360 | if (staticField) |
| 361 | fieldModifiers |= Modifier.STATIC; |
| 362 | |
| 363 | ClassMember field = classHold.addMember(getter, vmType, fieldModifiers); |
| 364 | int cpi = classHold.addFieldReference(field); |
| 365 | |
| 366 | /* |
| 367 | ** add the get method |
| 368 | */ |
| 369 | |
| 370 | String sig = BCMethodDescriptor.get(BCMethodDescriptor.EMPTY, vmType, factory); |
| 371 | |
| 372 | ClassMember method = classHold.addMember(getter, sig, methodModifers); |
| 373 | |
| 374 | CodeChunk chunk = new CodeChunk(); |
| 375 | |
| 376 | // load 'this' if required |
| 377 | if (!staticField) |
| 378 | chunk.addInstr(VMOpcode.ALOAD_0); // this |
| 379 | |
| 380 | // get the field value |
| 381 | chunk.addInstrU2((staticField ? VMOpcode.GETSTATIC : VMOpcode.GETFIELD), cpi); |
| 382 | |
| 383 | // and return it |
| 384 | short vmTypeId = BCJava.vmTypeId(vmType); |
| 385 | |
| 386 | chunk.addInstr(CodeChunk.RETURN_OPCODE[vmTypeId]); |
| 387 | |
| 388 | int typeWidth = Type.width(vmTypeId); |
| 389 | chunk.complete(null, classHold, method, typeWidth, 1); |
| 390 | |
| 391 | /* |
| 392 | ** add the set method |
| 393 | */ |
| 394 | String[] pda = new String[1]; |
| 395 | pda[0] = vmType; |
| 396 | sig = new BCMethodDescriptor(pda, VMDescriptor.VOID, factory).toString(); |
| 397 | method = classHold.addMember(setter, sig, methodModifers); |
| 398 | chunk = new CodeChunk(); |
| 399 | |
| 400 | // load 'this' if required |
| 401 | if (!staticField) |
| 402 | chunk.addInstr(VMOpcode.ALOAD_0); // this |
| 403 | // push the only parameter |
| 404 | chunk.addInstr((short) (CodeChunk.LOAD_VARIABLE_FAST[vmTypeId] + 1)); |
| 405 | |
| 406 | // and set the field |
| 407 | chunk.addInstrU2((staticField ? VMOpcode.PUTSTATIC : VMOpcode.PUTFIELD), cpi); |
| 408 | |
| 409 | chunk.addInstr(VMOpcode.RETURN); |
| 410 | |
| 411 | chunk.complete(null, classHold, method, typeWidth + (staticField ? 0 : 1), 1 + typeWidth); |
| 412 | } |
| 413 | |
| 414 | /** |
| 415 | * Add the fact that some class limit was exceeded while generating |
| 416 | * the class. We create a set ofg them and report at the end, this |
| 417 | * allows the generated class file to still be dumped. |
| 418 | * @param mb |
| 419 | * @param limitName |
| 420 | * @param limit |
| 421 | * @param value |
| 422 | */ |
| 423 | void addLimitExceeded(BCMethod mb, String limitName, int limit, int value) |
| 424 | { |
| 425 | StringBuffer sb = new StringBuffer(); |
| 426 | if (limitMsg != null) |
| 427 | { |
| 428 | sb.append(limitMsg); |
| 429 | sb.append(", "); |
| 430 | } |
| 431 | |
| 432 | sb.append("method:"); |
| 433 | sb.append(mb.getName()); |
| 434 | sb.append(" "); |
| 435 | sb.append(limitName); |
| 436 | sb.append(" ("); |
| 437 | sb.append(value); |
| 438 | sb.append(" > "); |
| 439 | sb.append(limit); |
| 440 | sb.append(")"); |
| 441 | |
| 442 | limitMsg = sb.toString(); |
| 443 | } |
| 444 | |
| 445 | } |