001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.compress.harmony.unpack200.bytecode.forms; 018 019import java.util.HashMap; 020import java.util.Map; 021 022import org.apache.commons.compress.harmony.unpack200.bytecode.ByteCode; 023import org.apache.commons.compress.harmony.unpack200.bytecode.CodeAttribute; 024import org.apache.commons.compress.harmony.unpack200.bytecode.OperandManager; 025 026public abstract class ByteCodeForm { 027 028 protected static final boolean WIDENED = true; 029 030 protected static final ByteCodeForm[] byteCodeArray = new ByteCodeForm[256]; 031 protected static final Map<String, ByteCodeForm> byteCodesByName = new HashMap<>(256); 032 static { 033 byteCodeArray[0] = new NoArgumentForm(0, "nop"); 034 byteCodeArray[1] = new NoArgumentForm(1, "aconst_null"); 035 byteCodeArray[2] = new NoArgumentForm(2, "iconst_m1"); 036 byteCodeArray[3] = new NoArgumentForm(3, "iconst_0"); 037 byteCodeArray[4] = new NoArgumentForm(4, "iconst_1"); 038 byteCodeArray[5] = new NoArgumentForm(5, "iconst_2"); 039 byteCodeArray[6] = new NoArgumentForm(6, "iconst_3"); 040 byteCodeArray[7] = new NoArgumentForm(7, "iconst_4"); 041 byteCodeArray[8] = new NoArgumentForm(8, "iconst_5"); 042 byteCodeArray[9] = new NoArgumentForm(9, "lconst_0"); 043 byteCodeArray[10] = new NoArgumentForm(10, "lconst_1"); 044 byteCodeArray[11] = new NoArgumentForm(11, "fconst_0"); 045 byteCodeArray[12] = new NoArgumentForm(12, "fconst_1"); 046 byteCodeArray[13] = new NoArgumentForm(13, "fconst_2"); 047 byteCodeArray[14] = new NoArgumentForm(14, "dconst_0"); 048 byteCodeArray[15] = new NoArgumentForm(15, "dconst_1"); 049 byteCodeArray[16] = new ByteForm(16, "bipush", new int[] {16, -1}); 050 byteCodeArray[17] = new ShortForm(17, "sipush", new int[] {17, -1, -1}); 051 byteCodeArray[18] = new StringRefForm(18, "ldc", new int[] {18, -1}); 052 byteCodeArray[19] = new StringRefForm(19, "ldc_w", new int[] {19, -1, -1}, WIDENED); 053 byteCodeArray[20] = new LongForm(20, "ldc2_w", new int[] {20, -1, -1}); 054 byteCodeArray[21] = new LocalForm(21, "iload", new int[] {21, -1}); 055 byteCodeArray[22] = new LocalForm(22, "lload", new int[] {22, -1}); 056 byteCodeArray[23] = new LocalForm(23, "fload", new int[] {23, -1}); 057 byteCodeArray[24] = new LocalForm(24, "dload", new int[] {24, -1}); 058 byteCodeArray[25] = new LocalForm(25, "aload", new int[] {25, -1}); 059 byteCodeArray[26] = new NoArgumentForm(26, "iload_0"); 060 byteCodeArray[27] = new NoArgumentForm(27, "iload_1"); 061 byteCodeArray[28] = new NoArgumentForm(28, "iload_2"); 062 byteCodeArray[29] = new NoArgumentForm(29, "iload_3"); 063 byteCodeArray[30] = new NoArgumentForm(30, "lload_0"); 064 byteCodeArray[31] = new NoArgumentForm(31, "lload_1"); 065 byteCodeArray[32] = new NoArgumentForm(32, "lload_2"); 066 byteCodeArray[33] = new NoArgumentForm(33, "lload_3"); 067 byteCodeArray[34] = new NoArgumentForm(34, "fload_0"); 068 byteCodeArray[35] = new NoArgumentForm(35, "fload_1"); 069 byteCodeArray[36] = new NoArgumentForm(36, "fload_2"); 070 byteCodeArray[37] = new NoArgumentForm(37, "fload_3"); 071 byteCodeArray[38] = new NoArgumentForm(38, "dload_0"); 072 byteCodeArray[39] = new NoArgumentForm(39, "dload_1"); 073 byteCodeArray[40] = new NoArgumentForm(40, "dload_2"); 074 byteCodeArray[41] = new NoArgumentForm(41, "dload_3"); 075 byteCodeArray[42] = new NoArgumentForm(42, "aload_0"); 076 byteCodeArray[43] = new NoArgumentForm(43, "aload_1"); 077 byteCodeArray[44] = new NoArgumentForm(44, "aload_2"); 078 byteCodeArray[45] = new NoArgumentForm(45, "aload_3"); 079 byteCodeArray[46] = new NoArgumentForm(46, "iaload"); 080 byteCodeArray[47] = new NoArgumentForm(47, "laload"); 081 byteCodeArray[48] = new NoArgumentForm(48, "faload"); 082 byteCodeArray[49] = new NoArgumentForm(49, "daload"); 083 byteCodeArray[50] = new NoArgumentForm(50, "aaload"); 084 byteCodeArray[51] = new NoArgumentForm(51, "baload"); 085 byteCodeArray[52] = new NoArgumentForm(52, "caload"); 086 byteCodeArray[53] = new NoArgumentForm(53, "saload"); 087 byteCodeArray[54] = new LocalForm(54, "istore", new int[] {54, -1}); 088 byteCodeArray[55] = new LocalForm(55, "lstore", new int[] {55, -1}); 089 byteCodeArray[56] = new LocalForm(56, "fstore", new int[] {56, -1}); 090 byteCodeArray[57] = new LocalForm(57, "dstore", new int[] {57, -1}); 091 byteCodeArray[58] = new LocalForm(58, "astore", new int[] {58, -1}); 092 byteCodeArray[59] = new NoArgumentForm(59, "istore_0"); 093 byteCodeArray[60] = new NoArgumentForm(60, "istore_1"); 094 byteCodeArray[61] = new NoArgumentForm(61, "istore_2"); 095 byteCodeArray[62] = new NoArgumentForm(62, "istore_3"); 096 byteCodeArray[63] = new NoArgumentForm(63, "lstore_0"); 097 byteCodeArray[64] = new NoArgumentForm(64, "lstore_1"); 098 byteCodeArray[65] = new NoArgumentForm(65, "lstore_2"); 099 byteCodeArray[66] = new NoArgumentForm(66, "lstore_3"); 100 byteCodeArray[67] = new NoArgumentForm(67, "fstore_0"); 101 byteCodeArray[68] = new NoArgumentForm(68, "fstore_1"); 102 byteCodeArray[69] = new NoArgumentForm(69, "fstore_2"); 103 byteCodeArray[70] = new NoArgumentForm(70, "fstore_3"); 104 byteCodeArray[71] = new NoArgumentForm(71, "dstore_0"); 105 byteCodeArray[72] = new NoArgumentForm(72, "dstore_1"); 106 byteCodeArray[73] = new NoArgumentForm(73, "dstore_2"); 107 byteCodeArray[74] = new NoArgumentForm(74, "dstore_3"); 108 byteCodeArray[75] = new NoArgumentForm(75, "astore_0"); 109 byteCodeArray[76] = new NoArgumentForm(76, "astore_1"); 110 byteCodeArray[77] = new NoArgumentForm(77, "astore_2"); 111 byteCodeArray[78] = new NoArgumentForm(78, "astore_3"); 112 byteCodeArray[79] = new NoArgumentForm(79, "iastore"); 113 byteCodeArray[80] = new NoArgumentForm(80, "lastore"); 114 byteCodeArray[81] = new NoArgumentForm(81, "fastore"); 115 byteCodeArray[82] = new NoArgumentForm(82, "dastore"); 116 byteCodeArray[83] = new NoArgumentForm(83, "aastore"); 117 byteCodeArray[84] = new NoArgumentForm(84, "bastore"); 118 byteCodeArray[85] = new NoArgumentForm(85, "castore"); 119 byteCodeArray[86] = new NoArgumentForm(86, "sastore"); 120 byteCodeArray[87] = new NoArgumentForm(87, "pop"); 121 byteCodeArray[88] = new NoArgumentForm(88, "pop2"); 122 byteCodeArray[89] = new NoArgumentForm(89, "dup"); 123 byteCodeArray[90] = new NoArgumentForm(90, "dup_x1"); 124 byteCodeArray[91] = new NoArgumentForm(91, "dup_x2"); 125 byteCodeArray[92] = new NoArgumentForm(92, "dup2"); 126 byteCodeArray[93] = new NoArgumentForm(93, "dup2_x1"); 127 byteCodeArray[94] = new NoArgumentForm(94, "dup2_x2"); 128 byteCodeArray[95] = new NoArgumentForm(95, "swap"); 129 byteCodeArray[96] = new NoArgumentForm(96, "iadd"); 130 byteCodeArray[97] = new NoArgumentForm(97, "ladd"); 131 byteCodeArray[98] = new NoArgumentForm(98, "fadd"); 132 byteCodeArray[99] = new NoArgumentForm(99, "dadd"); 133 byteCodeArray[100] = new NoArgumentForm(100, "isub"); 134 byteCodeArray[101] = new NoArgumentForm(101, "lsub"); 135 byteCodeArray[102] = new NoArgumentForm(102, "fsub"); 136 byteCodeArray[103] = new NoArgumentForm(103, "dsub"); 137 byteCodeArray[104] = new NoArgumentForm(104, "imul"); 138 byteCodeArray[105] = new NoArgumentForm(105, "lmul"); 139 byteCodeArray[106] = new NoArgumentForm(106, "fmul"); 140 byteCodeArray[107] = new NoArgumentForm(107, "dmul"); 141 byteCodeArray[108] = new NoArgumentForm(108, "idiv"); 142 byteCodeArray[109] = new NoArgumentForm(109, "ldiv"); 143 byteCodeArray[110] = new NoArgumentForm(110, "fdiv"); 144 byteCodeArray[111] = new NoArgumentForm(111, "ddiv"); 145 byteCodeArray[112] = new NoArgumentForm(112, "irem"); 146 byteCodeArray[113] = new NoArgumentForm(113, "lrem"); 147 byteCodeArray[114] = new NoArgumentForm(114, "frem"); 148 byteCodeArray[115] = new NoArgumentForm(115, "drem"); 149 byteCodeArray[116] = new NoArgumentForm(116, ""); 150 byteCodeArray[117] = new NoArgumentForm(117, "lneg"); 151 byteCodeArray[118] = new NoArgumentForm(118, "fneg"); 152 byteCodeArray[119] = new NoArgumentForm(119, "dneg"); 153 byteCodeArray[120] = new NoArgumentForm(120, "ishl"); 154 byteCodeArray[121] = new NoArgumentForm(121, "lshl"); 155 byteCodeArray[122] = new NoArgumentForm(122, "ishr"); 156 byteCodeArray[123] = new NoArgumentForm(123, "lshr"); 157 byteCodeArray[124] = new NoArgumentForm(124, "iushr"); 158 byteCodeArray[125] = new NoArgumentForm(125, "lushr"); 159 byteCodeArray[126] = new NoArgumentForm(126, "iand"); 160 byteCodeArray[127] = new NoArgumentForm(127, "land"); 161 byteCodeArray[128] = new NoArgumentForm(128, "ior"); 162 byteCodeArray[129] = new NoArgumentForm(129, "lor"); 163 byteCodeArray[130] = new NoArgumentForm(130, "ixor"); 164 byteCodeArray[131] = new NoArgumentForm(131, "lxor"); 165 byteCodeArray[132] = new IincForm(132, "iinc", new int[] {132, -1, -1}); 166 byteCodeArray[133] = new NoArgumentForm(133, "i2l"); 167 byteCodeArray[134] = new NoArgumentForm(134, "i2f"); 168 byteCodeArray[135] = new NoArgumentForm(135, "i2d"); 169 byteCodeArray[136] = new NoArgumentForm(136, "l2i"); 170 byteCodeArray[137] = new NoArgumentForm(137, "l2f"); 171 byteCodeArray[138] = new NoArgumentForm(138, "l2d"); 172 byteCodeArray[139] = new NoArgumentForm(139, "f2i"); 173 byteCodeArray[140] = new NoArgumentForm(140, "f2l"); 174 byteCodeArray[141] = new NoArgumentForm(141, "f2d"); 175 byteCodeArray[142] = new NoArgumentForm(142, "d2i"); 176 byteCodeArray[143] = new NoArgumentForm(143, "d2l"); 177 byteCodeArray[144] = new NoArgumentForm(144, "d2f"); 178 byteCodeArray[145] = new NoArgumentForm(145, "i2b"); 179 byteCodeArray[146] = new NoArgumentForm(146, "i2c"); 180 byteCodeArray[147] = new NoArgumentForm(147, "i2s"); 181 byteCodeArray[148] = new NoArgumentForm(148, "lcmp"); 182 byteCodeArray[149] = new NoArgumentForm(149, "fcmpl"); 183 byteCodeArray[150] = new NoArgumentForm(150, "fcmpg"); 184 byteCodeArray[151] = new NoArgumentForm(151, "dcmpl"); 185 byteCodeArray[152] = new NoArgumentForm(152, "dcmpg"); 186 byteCodeArray[153] = new LabelForm(153, "ifeq", new int[] {153, -1, -1}); 187 byteCodeArray[154] = new LabelForm(154, "ifne", new int[] {154, -1, -1}); 188 byteCodeArray[155] = new LabelForm(155, "iflt", new int[] {155, -1, -1}); 189 byteCodeArray[156] = new LabelForm(156, "ifge", new int[] {156, -1, -1}); 190 byteCodeArray[157] = new LabelForm(157, "ifgt", new int[] {157, -1, -1}); 191 byteCodeArray[158] = new LabelForm(158, "ifle", new int[] {158, -1, -1}); 192 byteCodeArray[159] = new LabelForm(159, "if_icmpeq", new int[] {159, -1, -1}); 193 byteCodeArray[160] = new LabelForm(160, "if_icmpne", new int[] {160, -1, -1}); 194 byteCodeArray[161] = new LabelForm(161, "if_icmplt", new int[] {161, -1, -1}); 195 byteCodeArray[162] = new LabelForm(162, "if_icmpge", new int[] {162, -1, -1}); 196 byteCodeArray[163] = new LabelForm(163, "if_icmpgt", new int[] {163, -1, -1}); 197 byteCodeArray[164] = new LabelForm(164, "if_icmple", new int[] {164, -1, -1}); 198 byteCodeArray[165] = new LabelForm(165, "if_acmpeq", new int[] {165, -1, -1}); 199 byteCodeArray[166] = new LabelForm(166, "if_acmpne", new int[] {166, -1, -1}); 200 byteCodeArray[167] = new LabelForm(167, "goto", new int[] {167, -1, -1}); 201 byteCodeArray[168] = new LabelForm(168, "jsr", new int[] {168, -1, -1}); 202 byteCodeArray[169] = new LocalForm(169, "ret", new int[] {169, -1}); 203 byteCodeArray[170] = new TableSwitchForm(170, "tableswitch"); 204 byteCodeArray[171] = new LookupSwitchForm(171, "lookupswitch"); 205 byteCodeArray[172] = new NoArgumentForm(172, "ireturn"); 206 byteCodeArray[173] = new NoArgumentForm(173, "lreturn"); 207 byteCodeArray[174] = new NoArgumentForm(174, "freturn"); 208 byteCodeArray[175] = new NoArgumentForm(175, "dreturn"); 209 byteCodeArray[176] = new NoArgumentForm(176, "areturn"); 210 byteCodeArray[177] = new NoArgumentForm(177, "return"); 211 byteCodeArray[178] = new FieldRefForm(178, "getstatic", new int[] {178, -1, -1}); 212 byteCodeArray[179] = new FieldRefForm(179, "putstatic", new int[] {179, -1, -1}); 213 byteCodeArray[180] = new FieldRefForm(180, "getfield", new int[] {180, -1, -1}); 214 byteCodeArray[181] = new FieldRefForm(181, "putfield", new int[] {181, -1, -1}); 215 byteCodeArray[182] = new MethodRefForm(182, "invokevirtual", new int[] {182, -1, -1}); 216 byteCodeArray[183] = new MethodRefForm(183, "invokespecial", new int[] {183, -1, -1}); 217 byteCodeArray[184] = new MethodRefForm(184, "invokestatic", new int[] {184, -1, -1}); 218 byteCodeArray[185] = new IMethodRefForm(185, "invokeinterface", new int[] {185, -1, -1, /* count */-1, 0}); 219 byteCodeArray[186] = new NoArgumentForm(186, "xxxunusedxxx"); 220 byteCodeArray[187] = new NewClassRefForm(187, "new", new int[] {187, -1, -1}); 221 byteCodeArray[188] = new ByteForm(188, "newarray", new int[] {188, -1}); 222 byteCodeArray[189] = new ClassRefForm(189, "anewarray", new int[] {189, -1, -1}); 223 byteCodeArray[190] = new NoArgumentForm(190, "arraylength"); 224 byteCodeArray[191] = new NoArgumentForm(191, "athrow"); 225 byteCodeArray[192] = new ClassRefForm(192, "checkcast", new int[] {192, -1, -1}); 226 byteCodeArray[193] = new ClassRefForm(193, "instanceof", new int[] {193, -1, -1}); 227 byteCodeArray[194] = new NoArgumentForm(194, "monitorenter"); 228 byteCodeArray[195] = new NoArgumentForm(195, "monitorexit"); 229 byteCodeArray[196] = new WideForm(196, "wide"); 230 byteCodeArray[197] = new MultiANewArrayForm(197, "multianewarray", new int[] {197, -1, -1, -1}); 231 byteCodeArray[198] = new LabelForm(198, "ifnull", new int[] {198, -1, -1}); 232 byteCodeArray[199] = new LabelForm(199, "ifnonnull", new int[] {199, -1, -1}); 233 byteCodeArray[200] = new LabelForm(200, "goto_w", new int[] {200, -1, -1, -1, -1}, WIDENED); 234 byteCodeArray[201] = new LabelForm(201, "jsr_w", new int[] {201, -1, -1, -1, -1}, WIDENED); 235 236 // Extra ones defined by pack200 237 byteCodeArray[202] = new ThisFieldRefForm(202, "getstatic_this", new int[] {178, -1, -1}); 238 byteCodeArray[203] = new ThisFieldRefForm(203, "putstatic_this", new int[] {179, -1, -1}); 239 byteCodeArray[204] = new ThisFieldRefForm(204, "getfield_this", new int[] {180, -1, -1}); 240 byteCodeArray[205] = new ThisFieldRefForm(205, "putfield_this", new int[] {181, -1, -1}); 241 byteCodeArray[206] = new ThisMethodRefForm(206, "invokevirtual_this", new int[] {182, -1, -1}); 242 byteCodeArray[207] = new ThisMethodRefForm(207, "invokespecial_this", new int[] {183, -1, -1}); 243 byteCodeArray[208] = new ThisMethodRefForm(208, "invokestatic_this", new int[] {184, -1, -1}); 244 byteCodeArray[209] = new ThisFieldRefForm(209, "aload_0_getstatic_this", new int[] {42, 178, -1, -1}); 245 byteCodeArray[210] = new ThisFieldRefForm(210, "aload_0_putstatic_this", new int[] {42, 179, -1, -1}); 246 byteCodeArray[211] = new ThisFieldRefForm(211, "aload_0_getfield_this", new int[] {42, 180, -1, -1}); 247 byteCodeArray[212] = new ThisFieldRefForm(212, "aload_0_putfield_this", new int[] {42, 181, -1, -1}); 248 byteCodeArray[213] = new ThisMethodRefForm(213, "aload_0_invokevirtual_this", new int[] {42, 182, -1, -1}); 249 byteCodeArray[214] = new ThisMethodRefForm(214, "aload_0_invokespecial_this", new int[] {42, 183, -1, -1}); 250 byteCodeArray[215] = new ThisMethodRefForm(215, "aload_0_invokestatic_this", new int[] {42, 184, -1, -1}); 251 byteCodeArray[216] = new SuperFieldRefForm(216, "getstatic_super", new int[] {178, -1, -1}); 252 byteCodeArray[217] = new SuperFieldRefForm(217, "putstatic_super", new int[] {179, -1, -1}); 253 byteCodeArray[218] = new SuperFieldRefForm(218, "getfield_super", new int[] {180, -1, -1}); 254 byteCodeArray[219] = new SuperFieldRefForm(219, "putfield_super", new int[] {181, -1, -1}); 255 byteCodeArray[220] = new SuperMethodRefForm(220, "invokevirtual_super", new int[] {182, -1, -1}); 256 byteCodeArray[221] = new SuperMethodRefForm(221, "invokespecial_super", new int[] {183, -1, -1}); 257 byteCodeArray[222] = new SuperMethodRefForm(222, "invokestatic_super", new int[] {184, -1, -1}); 258 byteCodeArray[223] = new SuperFieldRefForm(223, "aload_0_getstatic_super", new int[] {42, 178, -1, -1}); 259 byteCodeArray[224] = new SuperFieldRefForm(224, "aload_0_putstatic_super", new int[] {42, 179, -1, -1}); 260 byteCodeArray[225] = new SuperFieldRefForm(225, "aload_0_getfield_super", new int[] {42, 180, -1, -1}); 261 byteCodeArray[226] = new SuperFieldRefForm(226, "aload_0_putfield_super", new int[] {42, 181, -1, -1}); 262 byteCodeArray[227] = new SuperMethodRefForm(227, "aload_0_invokevirtual_super", new int[] {42, 182, -1, -1}); 263 byteCodeArray[228] = new SuperMethodRefForm(228, "aload_0_invokespecial_super", new int[] {42, 183, -1, -1}); 264 byteCodeArray[229] = new SuperMethodRefForm(229, "aload_0_invokestatic_super", new int[] {42, 184, -1, -1}); 265 byteCodeArray[230] = new ThisInitMethodRefForm(230, "invokespecial_this_init", new int[] {183, -1, -1}); 266 byteCodeArray[231] = new SuperInitMethodRefForm(231, "invokespecial_super_init", new int[] {183, -1, -1}); 267 byteCodeArray[232] = new NewInitMethodRefForm(232, "invokespecial_new_init", new int[] {183, -1, -1}); 268 byteCodeArray[233] = new NarrowClassRefForm(233, "cldc", new int[] {18, -1}); 269 byteCodeArray[234] = new IntRefForm(234, "ildc", new int[] {18, -1}); 270 byteCodeArray[235] = new FloatRefForm(235, "fldc", new int[] {18, -1}); 271 byteCodeArray[236] = new NarrowClassRefForm(236, "cldc_w", new int[] {19, -1, -1}, WIDENED); 272 byteCodeArray[237] = new IntRefForm(237, "ildc_w", new int[] {19, -1, -1}, WIDENED); 273 byteCodeArray[238] = new FloatRefForm(238, "fldc_w", new int[] {19, -1, -1}, WIDENED); 274 byteCodeArray[239] = new DoubleForm(239, "dldc2_w", new int[] {20, -1, -1}); 275 276 // Reserved bytecodes 277 byteCodeArray[254] = new NoArgumentForm(254, "impdep1"); 278 byteCodeArray[255] = new NoArgumentForm(255, "impdep2"); 279 280 // Bytecodes that aren't defined in the spec but are useful when 281 // unpacking (all must be >255) 282 // maybe wide versions of the others? etc. 283 284 // Put all the bytecodes in a HashMap so we can 285 // get them by either name or number 286 for (final ByteCodeForm byteCode : byteCodeArray) { 287 if (byteCode != null) { 288 byteCodesByName.put(byteCode.getName(), byteCode); 289 } 290 } 291 } 292 293 private final int opcode; 294 private final String name; 295 private final int[] rewrite; 296 private int firstOperandIndex; 297 private int operandLength; 298 299 /** 300 * Answer a new instance of this class with the specified opcode and name. Assume no rewrite. 301 * 302 * @param opcode int corresponding to the opcode's value 303 * @param name String printable name of the opcode 304 */ 305 public ByteCodeForm(final int opcode, final String name) { 306 this(opcode, name, new int[] {opcode}); 307 } 308 309 /** 310 * Answer a new instance of this class with the specified opcode, name, operandType and rewrite 311 * 312 * @param opcode int corresponding to the opcode's value 313 * @param name String printable name of the opcode 314 * @param rewrite int[] Array of ints. Operand positions (which will later be rewritten in ByteCodes) are indicated 315 * by -1. 316 */ 317 public ByteCodeForm(final int opcode, final String name, final int[] rewrite) { 318 this.opcode = opcode; 319 this.name = name; 320 this.rewrite = rewrite; 321 calculateOperandPosition(); 322 } 323 324 protected void calculateOperandPosition() { 325 firstOperandIndex = -1; 326 operandLength = -1; 327 328 // Find the first negative number in the rewrite array 329 int iterationIndex = 0; 330 while (iterationIndex < rewrite.length) { 331 if (rewrite[iterationIndex] < 0) { 332 // Found the first opcode to substitute 333 firstOperandIndex = iterationIndex; 334 iterationIndex = rewrite.length; 335 } else { 336 iterationIndex++; 337 } 338 } 339 340 if (firstOperandIndex == -1) { 341 // Nothing more to do since the opcode has no operands 342 return; 343 } 344 345 // Find the last negative number in the rewrite array 346 int lastOperandIndex = -1; 347 iterationIndex = firstOperandIndex; 348 while (iterationIndex < rewrite.length) { 349 if (rewrite[iterationIndex] < 0) { 350 lastOperandIndex = iterationIndex; 351 } 352 iterationIndex++; 353 } 354 355 // Now we have the first index and the last index. 356 final int difference = lastOperandIndex - firstOperandIndex; 357 358 // If last < first, something is wrong. 359 if (difference < 0) { 360 throw new Error("Logic error: not finding rewrite operands correctly"); 361 } 362 operandLength = difference + 1; 363 } 364 365 public static ByteCodeForm get(final int opcode) { 366 return byteCodeArray[opcode]; 367 } 368 369 @Override 370 public String toString() { 371 return this.getClass().getName() + "(" + getName() + ")"; 372 } 373 374 public int getOpcode() { 375 return opcode; 376 } 377 378 public String getName() { 379 return name; 380 } 381 382 public int[] getRewrite() { 383 return rewrite; 384 } 385 386 public int[] getRewriteCopy() { 387 final int[] result = new int[rewrite.length]; 388 System.arraycopy(rewrite, 0, result, 0, rewrite.length); 389 return result; 390 } 391 392 public int firstOperandIndex() { 393 return firstOperandIndex; 394 } 395 396 public int operandLength() { 397 return operandLength; 398 } 399 400 public boolean hasNoOperand() { 401 return false; 402 } 403 404 /** 405 * This method will answer true if the receiver is a multi-bytecode instruction (such as aload0_putfield_super); 406 * otherwise, it will answer false. 407 * 408 * @return boolean true if multibytecode, false otherwise 409 */ 410 public boolean hasMultipleByteCodes() { 411 // Currently, all multi-bytecode instructions 412 // begin with aload_0, so this is how we test. 413 if ((rewrite.length > 1) && (rewrite[0] == 42)) { 414 // If there's an instruction (not a negative 415 // number, which is an operand) after the 416 // aload_0, it's a multibytecode instruction. 417 return (rewrite[1] > 0); 418 } 419 return false; 420 } 421 422 /** 423 * When passed a byteCode, an OperandTable and a SegmentConstantPool, this method will set the rewrite of the 424 * byteCode appropriately. 425 * 426 * @param byteCode ByteCode to be updated (!) 427 * @param operandManager OperandTable from which to draw info 428 * @param codeLength Length of bytes (excluding this bytecode) from the beginning of the method. Used in calculating 429 * padding for some variable-length bytecodes (such as lookupswitch, tableswitch). 430 */ 431 public abstract void setByteCodeOperands(ByteCode byteCode, OperandManager operandManager, int codeLength); 432 433 /** 434 * The ByteCodeForm knows how to fix up a bytecode if it needs to be fixed up because it holds a Label bytecode. 435 * 436 * @param byteCode a ByteCode to be fixed up 437 * @param codeAttribute a CodeAttribute used to determine how the ByteCode should be fixed up. 438 */ 439 public void fixUpByteCodeTargets(final ByteCode byteCode, final CodeAttribute codeAttribute) { 440 // Most ByteCodeForms don't have any fixing up to do. 441 return; 442 } 443 444 public boolean nestedMustStartClassPool() { 445 return false; 446 } 447}