| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.impl.services.bytecode.CodeChunk |
| 4 | |
| 5 | Copyright 1998, 2006 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.classfile.CONSTANT_Index_info; |
| 24 | import org.apache.derby.iapi.services.classfile.CONSTANT_Utf8_info; |
| 25 | import org.apache.derby.iapi.services.classfile.ClassFormatOutput; |
| 26 | import org.apache.derby.iapi.services.classfile.ClassHolder; |
| 27 | import org.apache.derby.iapi.services.classfile.ClassMember; |
| 28 | import org.apache.derby.iapi.services.classfile.VMDescriptor; |
| 29 | |
| 30 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 31 | import org.apache.derby.iapi.services.classfile.VMOpcode; |
| 32 | import org.apache.derby.iapi.services.io.ArrayOutputStream; |
| 33 | |
| 34 | import java.io.IOException; |
| 35 | import java.lang.reflect.Modifier; |
| 36 | import java.util.Arrays; |
| 37 | |
| 38 | /** |
| 39 | * This class represents a chunk of code in a CodeAttribute. |
| 40 | * Typically, a CodeAttribute represents the code in a method. |
| 41 | * If there is a try/catch block, each catch block will get its |
| 42 | * own code chunk. This allows the catch blocks to all be put at |
| 43 | * the end of the generated code for a method, which eliminates |
| 44 | * the need to generate a jump around each catch block, which |
| 45 | * would be a forward reference. |
| 46 | */ |
| 47 | final class CodeChunk { |
| 48 | |
| 49 | /** |
| 50 | * Starting point of the byte code stream in the underlying stream/array. |
| 51 | */ |
| 52 | private static final int CODE_OFFSET = 8; |
| 53 | |
| 54 | // The use of ILOAD for the non-integer types is correct. |
| 55 | // We have to assume that the appropriate checks/conversions |
| 56 | // are defined on math operation results to ensure that |
| 57 | // the type is preserved when/as needed. |
| 58 | static final short[] LOAD_VARIABLE = { |
| 59 | VMOpcode.ILOAD, /* vm_byte */ |
| 60 | VMOpcode.ILOAD, /* vm_short */ |
| 61 | VMOpcode.ILOAD, /* vm_int */ |
| 62 | VMOpcode.LLOAD, /* vm_long */ |
| 63 | VMOpcode.FLOAD, /* vm_float */ |
| 64 | VMOpcode.DLOAD, /* vm_double */ |
| 65 | VMOpcode.ILOAD, /* vm_char */ |
| 66 | VMOpcode.ALOAD /* vm_reference */ |
| 67 | }; |
| 68 | |
| 69 | static final short[] LOAD_VARIABLE_FAST = { |
| 70 | VMOpcode.ILOAD_0, /* vm_byte */ |
| 71 | VMOpcode.ILOAD_0, /* vm_short */ |
| 72 | VMOpcode.ILOAD_0, /* vm_int */ |
| 73 | VMOpcode.LLOAD_0, /* vm_long */ |
| 74 | VMOpcode.FLOAD_0, /* vm_float */ |
| 75 | VMOpcode.DLOAD_0, /* vm_double */ |
| 76 | VMOpcode.ILOAD_0, /* vm_char */ |
| 77 | VMOpcode.ALOAD_0 /* vm_reference */ |
| 78 | }; |
| 79 | |
| 80 | // The ISTOREs for non-int types are how things work. |
| 81 | // It assumes that the appropriate casts are done |
| 82 | // on operations on non-ints to ensure that the values |
| 83 | // remain in the valid ranges. |
| 84 | static final short[] STORE_VARIABLE = { |
| 85 | VMOpcode.ISTORE, /* vm_byte */ |
| 86 | VMOpcode.ISTORE, /* vm_short */ |
| 87 | VMOpcode.ISTORE, /* vm_int */ |
| 88 | VMOpcode.LSTORE, /* vm_long */ |
| 89 | VMOpcode.FSTORE, /* vm_float */ |
| 90 | VMOpcode.DSTORE, /* vm_double */ |
| 91 | VMOpcode.ISTORE, /* vm_char */ |
| 92 | VMOpcode.ASTORE /* vm_reference */ |
| 93 | }; |
| 94 | |
| 95 | static final short[] STORE_VARIABLE_FAST = { |
| 96 | VMOpcode.ISTORE_0, /* vm_byte */ |
| 97 | VMOpcode.ISTORE_0, /* vm_short */ |
| 98 | VMOpcode.ISTORE_0, /* vm_int */ |
| 99 | VMOpcode.LSTORE_0, /* vm_long */ |
| 100 | VMOpcode.FSTORE_0, /* vm_float */ |
| 101 | VMOpcode.DSTORE_0, /* vm_double */ |
| 102 | VMOpcode.ISTORE_0, /* vm_char */ |
| 103 | VMOpcode.ASTORE_0 /* vm_reference */ |
| 104 | }; |
| 105 | |
| 106 | static final short ARRAY_ACCESS[] = { |
| 107 | VMOpcode.BALOAD, /* vm_byte */ |
| 108 | VMOpcode.SALOAD, /* vm_short */ |
| 109 | VMOpcode.IALOAD, /* vm_int */ |
| 110 | VMOpcode.LALOAD, /* vm_long */ |
| 111 | VMOpcode.FALOAD, /* vm_float */ |
| 112 | VMOpcode.DALOAD, /* vm_double */ |
| 113 | VMOpcode.CALOAD, /* vm_char */ |
| 114 | VMOpcode.AALOAD /* vm_reference */ |
| 115 | }; |
| 116 | static final short ARRAY_STORE[] = { |
| 117 | VMOpcode.BASTORE, /* vm_byte */ |
| 118 | VMOpcode.SASTORE, /* vm_short */ |
| 119 | VMOpcode.IASTORE, /* vm_int */ |
| 120 | VMOpcode.LASTORE, /* vm_long */ |
| 121 | VMOpcode.FASTORE, /* vm_float */ |
| 122 | VMOpcode.DASTORE, /* vm_double */ |
| 123 | VMOpcode.CASTORE, /* vm_char */ |
| 124 | VMOpcode.AASTORE /* vm_reference */ |
| 125 | }; |
| 126 | static final short[] RETURN_OPCODE = { |
| 127 | VMOpcode.IRETURN, /* 0 = byte */ |
| 128 | VMOpcode.IRETURN, /* 1 = short */ |
| 129 | VMOpcode.IRETURN, /* 2 = int */ |
| 130 | VMOpcode.LRETURN, /* 3 = long */ |
| 131 | VMOpcode.FRETURN, /* 4 = float */ |
| 132 | VMOpcode.DRETURN, /* 5 = double */ |
| 133 | VMOpcode.IRETURN, /* 6 = char */ |
| 134 | VMOpcode.ARETURN /* 7 = reference */ |
| 135 | }; |
| 136 | |
| 137 | // the first dimension is the current vmTypeId |
| 138 | // the second dimension is the target vmTypeId |
| 139 | // |
| 140 | // the cells of the entry at [current,target] are: |
| 141 | // 0: operation |
| 142 | // 1: result type of operation |
| 143 | // if entry[1] = target, we are done. otherwise, |
| 144 | // you have to continue with entry[1] as the new current |
| 145 | // after generating the opcode listed (don't generate if it is NOP). |
| 146 | // if entry[0] = BAD, we can |
| 147 | |
| 148 | static final short CAST_CONVERSION_INFO[][][] = { |
| 149 | /* current = vm_byte */ |
| 150 | { |
| 151 | /* target = vm_byte */ { VMOpcode.NOP, BCExpr.vm_byte }, |
| 152 | /* target = vm_short */ { VMOpcode.NOP, BCExpr.vm_short }, |
| 153 | /* target = vm_int */ { VMOpcode.NOP, BCExpr.vm_int }, |
| 154 | /* target = vm_long */ { VMOpcode.NOP, BCExpr.vm_int }, |
| 155 | /* target = vm_float */ { VMOpcode.NOP, BCExpr.vm_int }, |
| 156 | /* target = vm_double */ { VMOpcode.NOP, BCExpr.vm_int }, |
| 157 | /* target = vm_char */ { VMOpcode.NOP, BCExpr.vm_char }, |
| 158 | /* target = vm_reference */ { VMOpcode.BAD, BCExpr.vm_reference } |
| 159 | }, |
| 160 | /* current = vm_short */ |
| 161 | { |
| 162 | /* target = vm_byte */ { VMOpcode.NOP, BCExpr.vm_byte }, |
| 163 | /* target = vm_short */ { VMOpcode.NOP, BCExpr.vm_short }, |
| 164 | /* target = vm_int */ { VMOpcode.NOP, BCExpr.vm_int }, |
| 165 | /* target = vm_long */ { VMOpcode.NOP, BCExpr.vm_int }, |
| 166 | /* target = vm_float */ { VMOpcode.NOP, BCExpr.vm_int }, |
| 167 | /* target = vm_double */ { VMOpcode.NOP, BCExpr.vm_int }, |
| 168 | /* target = vm_char */ { VMOpcode.NOP, BCExpr.vm_char }, |
| 169 | /* target = vm_reference */ { VMOpcode.BAD, BCExpr.vm_reference } |
| 170 | }, |
| 171 | /* current = vm_int */ |
| 172 | { |
| 173 | /* target = vm_byte */ { VMOpcode.I2B, BCExpr.vm_byte }, |
| 174 | /* target = vm_short */ { VMOpcode.I2S, BCExpr.vm_short }, |
| 175 | /* target = vm_int */ { VMOpcode.NOP, BCExpr.vm_int }, |
| 176 | /* target = vm_long */ { VMOpcode.I2L, BCExpr.vm_long }, |
| 177 | /* target = vm_float */ { VMOpcode.I2F, BCExpr.vm_float }, |
| 178 | /* target = vm_double */ { VMOpcode.I2D, BCExpr.vm_double }, |
| 179 | /* target = vm_char */ { VMOpcode.I2B, BCExpr.vm_char }, |
| 180 | /* target = vm_reference */ { VMOpcode.BAD, BCExpr.vm_reference } |
| 181 | }, |
| 182 | /* current = vm_long */ |
| 183 | { |
| 184 | /* target = vm_byte */ { VMOpcode.L2I, BCExpr.vm_int }, |
| 185 | /* target = vm_short */ { VMOpcode.L2I, BCExpr.vm_int }, |
| 186 | /* target = vm_int */ { VMOpcode.L2I, BCExpr.vm_int }, |
| 187 | /* target = vm_long */ { VMOpcode.NOP, BCExpr.vm_long }, |
| 188 | /* target = vm_float */ { VMOpcode.L2F, BCExpr.vm_float }, |
| 189 | /* target = vm_double */ { VMOpcode.L2D, BCExpr.vm_double }, |
| 190 | /* target = vm_char */ { VMOpcode.L2I, BCExpr.vm_int }, |
| 191 | /* target = vm_reference */ { VMOpcode.BAD, BCExpr.vm_reference } |
| 192 | }, |
| 193 | /* current = vm_float */ |
| 194 | { |
| 195 | /* target = vm_byte */ { VMOpcode.F2I, BCExpr.vm_int }, |
| 196 | /* target = vm_short */ { VMOpcode.F2I, BCExpr.vm_int }, |
| 197 | /* target = vm_int */ { VMOpcode.F2I, BCExpr.vm_int }, |
| 198 | /* target = vm_long */ { VMOpcode.F2L, BCExpr.vm_long }, |
| 199 | /* target = vm_float */ { VMOpcode.NOP, BCExpr.vm_float }, |
| 200 | /* target = vm_double */ { VMOpcode.F2D, BCExpr.vm_double }, |
| 201 | /* target = vm_char */ { VMOpcode.F2I, BCExpr.vm_int }, |
| 202 | /* target = vm_reference */ { VMOpcode.BAD, BCExpr.vm_reference } |
| 203 | }, |
| 204 | /* current = vm_double */ |
| 205 | { |
| 206 | /* target = vm_byte */ { VMOpcode.D2I, BCExpr.vm_int }, |
| 207 | /* target = vm_short */ { VMOpcode.D2I, BCExpr.vm_int }, |
| 208 | /* target = vm_int */ { VMOpcode.D2I, BCExpr.vm_int }, |
| 209 | /* target = vm_long */ { VMOpcode.D2L, BCExpr.vm_long }, |
| 210 | /* target = vm_float */ { VMOpcode.D2F, BCExpr.vm_float }, |
| 211 | /* target = vm_double */ { VMOpcode.NOP, BCExpr.vm_double }, |
| 212 | /* target = vm_char */ { VMOpcode.D2I, BCExpr.vm_int }, |
| 213 | /* target = vm_reference */ { VMOpcode.BAD, BCExpr.vm_reference } |
| 214 | }, |
| 215 | /* current = vm_char */ |
| 216 | { |
| 217 | /* target = vm_byte */ { VMOpcode.NOP, BCExpr.vm_byte }, |
| 218 | /* target = vm_short */ { VMOpcode.NOP, BCExpr.vm_short }, |
| 219 | /* target = vm_int */ { VMOpcode.NOP, BCExpr.vm_int }, |
| 220 | /* target = vm_long */ { VMOpcode.NOP, BCExpr.vm_int }, |
| 221 | /* target = vm_float */ { VMOpcode.NOP, BCExpr.vm_int }, |
| 222 | /* target = vm_double */ { VMOpcode.NOP, BCExpr.vm_int }, |
| 223 | /* target = vm_char */ { VMOpcode.NOP, BCExpr.vm_char }, |
| 224 | /* target = vm_reference */ { VMOpcode.BAD, BCExpr.vm_reference } |
| 225 | }, |
| 226 | /* current = vm_reference */ |
| 227 | { |
| 228 | /* target = vm_byte */ { VMOpcode.BAD, BCExpr.vm_byte }, |
| 229 | /* target = vm_short */ { VMOpcode.BAD, BCExpr.vm_short }, |
| 230 | /* target = vm_int */ { VMOpcode.BAD, BCExpr.vm_int }, |
| 231 | /* target = vm_long */ { VMOpcode.BAD, BCExpr.vm_long }, |
| 232 | /* target = vm_float */ { VMOpcode.BAD, BCExpr.vm_float }, |
| 233 | /* target = vm_double */ { VMOpcode.BAD, BCExpr.vm_double }, |
| 234 | /* target = vm_char */ { VMOpcode.BAD, BCExpr.vm_char }, |
| 235 | /* target = vm_reference */ { VMOpcode.NOP, BCExpr.vm_reference } |
| 236 | } |
| 237 | }; |
| 238 | |
| 239 | /** |
| 240 | * Constant used by OPCODE_ACTION to represent the |
| 241 | * common action of push one word, 1 byte |
| 242 | * for the instruction. |
| 243 | */ |
| 244 | private static final byte[] push1_1i = {1, 1}; |
| 245 | |
| 246 | /** |
| 247 | * Constant used by OPCODE_ACTION to represent the |
| 248 | * common action of push two words, 1 byte |
| 249 | * for the instruction. |
| 250 | */ |
| 251 | private static final byte[] push2_1i = {2, 1}; |
| 252 | /** |
| 253 | * Constant used by OPCODE_ACTION to the opcode is |
| 254 | * not yet supported. |
| 255 | */ |
| 256 | private static final byte[] NS = {0, -1}; |
| 257 | |
| 258 | |
| 259 | /** |
| 260 | * Value for OPCODE_ACTION[opcode][0] to represent |
| 261 | * the number of words popped or pushed in variable. |
| 262 | */ |
| 263 | private static final byte VARIABLE_STACK = -128; |
| 264 | |
| 265 | /** |
| 266 | * Array that provides two pieces of information about |
| 267 | * each VM opcode. Each opcode has a two byte array. |
| 268 | * <P> |
| 269 | * The first element in the array [0] is the number of |
| 270 | * stack words (double/long count as two) pushed by the opcode. |
| 271 | * Will be negative if the opcode pops values. |
| 272 | * |
| 273 | * <P> |
| 274 | * The second element in the array [1] is the number of bytes |
| 275 | * in the instruction stream that this opcode's instruction |
| 276 | * takes up, including the opocode. |
| 277 | */ |
| 278 | private static final byte[][] OPCODE_ACTION = |
| 279 | { |
| 280 | |
| 281 | /* NOP 0 */ { 0, 1 }, |
| 282 | |
| 283 | /* ACONST_NULL 1 */ push1_1i, |
| 284 | /* ICONST_M1 2 */ push1_1i, |
| 285 | /* ICONST_0 3 */ push1_1i, |
| 286 | /* ICONST_1 4 */ push1_1i, |
| 287 | /* ICONST_2 5 */ push1_1i, |
| 288 | /* ICONST_3 6 */ push1_1i, |
| 289 | /* ICONST_4 7 */ push1_1i, |
| 290 | /* ICONST_5 8 */ push1_1i, |
| 291 | /* LCONST_0 9 */ push2_1i, |
| 292 | /* LCONST_1 10 */ push2_1i, |
| 293 | /* FCONST_0 11 */ push1_1i, |
| 294 | /* FCONST_1 12 */ push1_1i, |
| 295 | /* FCONST_2 13 */ push1_1i, |
| 296 | /* DCONST_0 14 */ push2_1i, |
| 297 | /* DCONST_1 15 */ push2_1i, |
| 298 | |
| 299 | /* BIPUSH 16 */ {1, 2}, |
| 300 | /* SIPUSH 17 */ {1, 3}, |
| 301 | /* LDC 18 */ {1, 2}, |
| 302 | /* LDC_W 19 */ {1, 3}, |
| 303 | /* LDC2_W 20 */ {2, 3}, |
| 304 | |
| 305 | /* ILOAD 21 */ { 1, 2 }, |
| 306 | /* LLOAD 22 */ { 2, 2 }, |
| 307 | /* FLOAD 23 */ { 1, 2 }, |
| 308 | /* DLOAD 24 */ { 2, 2 }, |
| 309 | /* ALOAD 25 */ { 1, 2 }, |
| 310 | /* ILOAD_0 26 */ push1_1i, |
| 311 | /* ILOAD_1 27 */ push1_1i, |
| 312 | /* ILOAD_2 28 */ push1_1i, |
| 313 | /* ILOAD_3 29 */ push1_1i, |
| 314 | /* LLOAD_0 30 */ push2_1i, |
| 315 | /* LLOAD_1 31 */ push2_1i, |
| 316 | /* LLOAD_2 32 */ push2_1i, |
| 317 | /* LLOAD_3 33 */ push2_1i, |
| 318 | /* FLOAD_0 34 */ push1_1i, |
| 319 | /* FLOAD_1 35 */ push1_1i, |
| 320 | /* FLOAD_2 36 */ push1_1i, |
| 321 | /* FLOAD_3 37 */ push1_1i, |
| 322 | /* DLOAD_0 38 */ push2_1i, |
| 323 | /* DLOAD_1 39 */ push2_1i, |
| 324 | /* DLOAD_2 40 */ push2_1i, |
| 325 | /* DLOAD_3 41 */ push2_1i, |
| 326 | /* ALOAD_0 42 */ push1_1i, |
| 327 | /* ALOAD_1 43 */ push1_1i, |
| 328 | /* ALOAD_2 44 */ push1_1i, |
| 329 | /* ALOAD_3 45 */ push1_1i, |
| 330 | /* IALOAD 46 */ { -1, 1 }, |
| 331 | /* LALOAD 47 */ { 0, 1 }, |
| 332 | /* FALOAD 48 */ { -1, 1 }, |
| 333 | /* DALOAD 49 */ { 0, 1 }, |
| 334 | /* AALOAD 50 */ { -1, 1 }, |
| 335 | /* BALOAD 51 */ { -1, 1 }, |
| 336 | /* CALOAD 52 */ { -1, 1 }, |
| 337 | |
| 338 | /* SALOAD 53 */ { -1, 1 }, |
| 339 | /* ISTORE 54 */ { -1, 2 }, |
| 340 | /* LSTORE 55 */ { -2, 2 }, |
| 341 | /* FSTORE 56 */ { -1, 2 }, |
| 342 | /* DSTORE 57 */ { -2, 2 }, |
| 343 | /* ASTORE 58 */ { -1, 2 }, |
| 344 | /* ISTORE_0 59 */ { -1, 1 }, |
| 345 | /* ISTORE_1 60 */ { -1, 1 }, |
| 346 | /* ISTORE_2 61 */ { -1, 1 }, |
| 347 | /* ISTORE_3 62 */ { -1, 1 }, |
| 348 | /* LSTORE_0 63 */ { -2, 1 }, |
| 349 | /* LSTORE_1 64 */ { -2, 1 }, |
| 350 | /* LSTORE_2 65 */ { -2, 1 }, |
| 351 | /* LSTORE_3 66 */ { -2, 1 }, |
| 352 | /* FSTORE_0 67 */ { -1, 1 }, |
| 353 | /* FSTORE_1 68 */ { -1, 1 }, |
| 354 | /* FSTORE_2 69 */ { -1, 1 }, |
| 355 | /* FSTORE_3 70 */ { -1, 1 }, |
| 356 | /* DSTORE_0 71 */ { -2, 1 }, |
| 357 | /* DSTORE_1 72 */ { -2, 1 }, |
| 358 | /* DSTORE_2 73 */ { -2, 1 }, |
| 359 | /* DSTORE_3 74 */ { -2, 1 }, |
| 360 | /* ASTORE_0 75 */ { -1, 1 }, |
| 361 | /* ASTORE_1 76 */ { -1, 1 }, |
| 362 | /* ASTORE_2 77 */ { -1, 1 }, |
| 363 | /* ASTORE_3 78 */ { -1, 1 }, |
| 364 | /* IASTORE 79 */ { -3, 1 }, |
| 365 | /* LASTORE 80 */ { -4, 1 }, |
| 366 | /* FASTORE 81 */ { -3, 1 }, |
| 367 | /* DASTORE 82 */ { -4, 1 }, |
| 368 | /* AASTORE 83 */ { -3, 1 }, |
| 369 | /* BASTORE 84 */ { -3, 1 }, |
| 370 | /* CASTORE 85 */ { -3, 1 }, |
| 371 | /* SASTORE 86 */ { -3, 1 }, |
| 372 | |
| 373 | /* POP 87 */ { -1, 1 }, |
| 374 | /* POP2 88 */ { -2, 1 }, |
| 375 | /* DUP 89 */ push1_1i, |
| 376 | /* DUP_X1 90 */ push1_1i, |
| 377 | /* DUP_X2 91 */ push1_1i, |
| 378 | /* DUP2 92 */ push2_1i, |
| 379 | /* DUP2_X1 93 */ push2_1i, |
| 380 | /* DUP2_X2 94 */ push2_1i, |
| 381 | /* SWAP 95 */ { 0, 1 }, |
| 382 | |
| 383 | /* IADD 96 */ NS, |
| 384 | /* LADD 97 */ NS, |
| 385 | /* FADD 98 */ { -1, 1 }, |
| 386 | /* DADD 99 */ { -2, 1 }, |
| 387 | /* ISUB 100 */ NS, |
| 388 | /* LSUB 101 */ NS, |
| 389 | /* FSUB 102 */ { -1, 1 }, |
| 390 | /* DSUB 103 */ { -2, 1 }, |
| 391 | /* IMUL 104 */ NS, |
| 392 | /* LMUL 105 */ NS, |
| 393 | /* FMUL 106 */ { -1, 1 }, |
| 394 | /* DMUL 107 */ { -2, 1 }, |
| 395 | /* IDIV 108 */ NS, |
| 396 | /* LDIV 109 */ NS, |
| 397 | /* FDIV 110 */ { -1, 1 }, |
| 398 | /* DDIV 111 */ { -2, 1 }, |
| 399 | /* IREM 112 */ { -1, 1 }, |
| 400 | /* LREM 113 */ { -2, 1 }, |
| 401 | /* FREM 114 */ { -1, 1 }, |
| 402 | /* DREM 115 */ { -2, 1 }, |
| 403 | /* INEG 116 */ { 0, 1 }, |
| 404 | /* LNEG 117 */ { 0, 1 }, |
| 405 | /* FNEG 118 */ { 0, 1 }, |
| 406 | /* DNEG 119 */ { 0, 1 }, |
| 407 | /* ISHL 120 */ { -1, 1 }, |
| 408 | /* LSHL 121 */ NS, |
| 409 | /* ISHR 122 */ NS, |
| 410 | /* LSHR 123 */ NS, |
| 411 | /* IUSHR 124 */ NS, |
| 412 | /* LUSHR 125 */ NS, |
| 413 | |
| 414 | /* IAND 126 */ { -1, 1 }, |
| 415 | /* LAND 127 */ NS, |
| 416 | /* IOR 128 */ { -1, 1 }, |
| 417 | /* LOR 129 */ NS, |
| 418 | /* IXOR 130 */ NS, |
| 419 | /* LXOR 131 */ NS, |
| 420 | /* IINC 132 */ NS, |
| 421 | |
| 422 | /* I2L 133 */ push1_1i, |
| 423 | /* I2F 134 */ { 0, 1 }, |
| 424 | /* I2D 135 */ push1_1i, |
| 425 | /* L2I 136 */ { -1, 1 }, |
| 426 | /* L2F 137 */ { -1, 1 }, |
| 427 | /* L2D 138 */ { 0, 1 }, |
| 428 | /* F2I 139 */ { 0, 1 }, |
| 429 | /* F2L 140 */ push2_1i, |
| 430 | /* F2D 141 */ push1_1i, |
| 431 | /* D2I 142 */ { -1, 1 }, |
| 432 | /* D2L 143 */ { 0, 1 }, |
| 433 | /* D2F 144 */ { -1, 1 }, |
| 434 | /* I2B 145 */ { 0, 1 }, |
| 435 | /* I2C 146 */ { 0, 1 }, |
| 436 | /* I2S 147 */ { 0, 1 }, |
| 437 | |
| 438 | /* LCMP 148 */ NS, |
| 439 | /* FCMPL 149 */ { -1, 1 }, |
| 440 | /* FCMPG 150 */ { -1, 1 }, |
| 441 | /* DCMPL 151 */ { -3, 1 }, |
| 442 | /* DCMPG 152 */ { -3, 1 }, |
| 443 | /* IFEQ 153 */ { -1, VMOpcode.IF_INS_LENGTH }, |
| 444 | /* IFNE 154 */ { -1, VMOpcode.IF_INS_LENGTH }, |
| 445 | /* IFLT 155 */ { -1, VMOpcode.IF_INS_LENGTH }, |
| 446 | /* IFGE 156 */ { -1, VMOpcode.IF_INS_LENGTH }, |
| 447 | /* IFGT 157 */ { -1, VMOpcode.IF_INS_LENGTH }, |
| 448 | /* IFLE 158 */ { -1, VMOpcode.IF_INS_LENGTH }, |
| 449 | /* IF_ICMPEQ 159 */ NS, |
| 450 | /* IF_ICMPNE 160 */ NS, |
| 451 | /* IF_ICMPLT 161 */ NS, |
| 452 | /* IF_ICMPGE 162 */ NS, |
| 453 | /* IF_ICMPGT 163 */ NS, |
| 454 | /* IF_ICMPLE 164 */ NS, |
| 455 | /* IF_ACMPEQ 165 */ NS, |
| 456 | /* IF_ACMPNE 166 */ NS, |
| 457 | /* GOTO 167 */ { 0, VMOpcode.GOTO_INS_LENGTH }, |
| 458 | /* JSR 168 */ NS, |
| 459 | /* RET 169 */ NS, |
| 460 | /* TABLESWITCH 170 */ NS, |
| 461 | /* LOOKUPSWITCH 171 */NS, |
| 462 | |
| 463 | /* IRETURN 172 */ { -1, 1 }, // strictly speaking all words on the stack are popped. |
| 464 | /* LRETURN 173 */ { -2, 1 }, // strictly speaking all words on the stack are popped. |
| 465 | /* FRETURN 174 */ { -1, 1 }, // strictly speaking all words on the stack are popped. |
| 466 | /* DRETURN 175 */ { -2, 1 }, // strictly speaking all words on the stack are popped. |
| 467 | /* ARETURN 176 */ { -1, 1 }, // strictly speaking all words on the stack are popped. |
| 468 | /* RETURN 177 */ { 0, 1 }, // strictly speaking all words on the stack are popped. |
| 469 | |
| 470 | /* GETSTATIC 178 */ {VARIABLE_STACK, 3 }, |
| 471 | /* PUTSTATIC 179 */ {VARIABLE_STACK, 3 }, |
| 472 | /* GETFIELD 180 */ {VARIABLE_STACK, 3 }, |
| 473 | /* PUTFIELD 181 */ {VARIABLE_STACK, 3 }, |
| 474 | /* INVOKEVIRTUAL 182 */ {VARIABLE_STACK, 3 }, |
| 475 | /* INVOKESPECIAL 183 */ {VARIABLE_STACK, 3 }, |
| 476 | /* INVOKESTATIC 184 */ {VARIABLE_STACK, 3 }, |
| 477 | /* INVOKEINTERFACE 185 */ {VARIABLE_STACK, 5 }, |
| 478 | |
| 479 | /* XXXUNUSEDXXX 186 */ NS, |
| 480 | |
| 481 | /* NEW 187 */ { 1, 3 }, |
| 482 | /* NEWARRAY 188 */ { 0, 2 }, |
| 483 | /* ANEWARRAY 189 */ { 0, 3 }, |
| 484 | /* ARRAYLENGTH 190 */ { 0, 1 }, |
| 485 | /* ATHROW 191 */ NS, |
| 486 | /* CHECKCAST 192 */ { 0, 3}, |
| 487 | /* INSTANCEOF 193 */ { 0, 3 }, |
| 488 | /* MONITORENTER 194 */ NS, |
| 489 | /* MONITOREXIT 195 */ NS, |
| 490 | /* WIDE 196 */ NS, |
| 491 | /* MULTIANEWARRAY 197 */ NS, |
| 492 | /* IFNULL 198 */ { -1, VMOpcode.IF_INS_LENGTH }, |
| 493 | /* IFNONNULL 199 */ { -1, VMOpcode.IF_INS_LENGTH }, |
| 494 | /* GOTO_W 200 */ {0, VMOpcode.GOTO_W_INS_LENGTH }, |
| 495 | /* JSR_W 201 */ NS, |
| 496 | /* BREAKPOINT 202 */ NS, |
| 497 | |
| 498 | }; |
| 499 | |
| 500 | |
| 501 | |
| 502 | /** |
| 503 | * Add an instruction that has no operand. |
| 504 | * All opcodes are 1 byte large. |
| 505 | */ |
| 506 | void addInstr(short opcode) { |
| 507 | try { |
| 508 | cout.putU1(opcode); |
| 509 | } catch (IOException ioe) { |
| 510 | } |
| 511 | |
| 512 | if (SanityManager.DEBUG) { |
| 513 | if (OPCODE_ACTION[opcode][1] != 1) |
| 514 | SanityManager.THROWASSERT("Opcode " + opcode + " incorrect entry in OPCODE_ACTION -" + |
| 515 | " writing 1 byte - set as " + OPCODE_ACTION[opcode][1]); |
| 516 | } |
| 517 | } |
| 518 | |
| 519 | /** |
| 520 | * Add an instruction that has a 16 bit operand. |
| 521 | */ |
| 522 | void addInstrU2(short opcode, int operand) { |
| 523 | try { |
| 524 | cout.putU1(opcode); |
| 525 | cout.putU2(operand); |
| 526 | } catch (IOException ioe) { |
| 527 | } |
| 528 | |
| 529 | if (SanityManager.DEBUG) { |
| 530 | if (OPCODE_ACTION[opcode][1] != 3) |
| 531 | SanityManager.THROWASSERT("Opcode " + opcode + " incorrect entry in OPCODE_ACTION -" + |
| 532 | " writing 3 bytes - set as " + OPCODE_ACTION[opcode][1]); |
| 533 | } |
| 534 | } |
| 535 | |
| 536 | /** |
| 537 | * Add an instruction that has a 32 bit operand. |
| 538 | */ |
| 539 | void addInstrU4(short opcode, int operand) { |
| 540 | try { |
| 541 | cout.putU1(opcode); |
| 542 | cout.putU4(operand); |
| 543 | } catch (IOException ioe) { |
| 544 | } |
| 545 | if (SanityManager.DEBUG) { |
| 546 | if (OPCODE_ACTION[opcode][1] != 5) |
| 547 | SanityManager.THROWASSERT("Opcode " + opcode + " incorrect entry in OPCODE_ACTION -" + |
| 548 | " writing 5 bytes - set as " + OPCODE_ACTION[opcode][1]); |
| 549 | } |
| 550 | } |
| 551 | |
| 552 | |
| 553 | /** |
| 554 | * Add an instruction that has an 8 bit operand. |
| 555 | */ |
| 556 | void addInstrU1(short opcode, int operand) { |
| 557 | try { |
| 558 | cout.putU1(opcode); |
| 559 | cout.putU1(operand); |
| 560 | } catch (IOException ioe) { |
| 561 | } |
| 562 | |
| 563 | // Only debug code from here. |
| 564 | if (SanityManager.DEBUG) { |
| 565 | |
| 566 | if (OPCODE_ACTION[opcode][1] != 2) |
| 567 | SanityManager.THROWASSERT("Opcode " + opcode + " incorrect entry in OPCODE_ACTION -" + |
| 568 | " writing 2 bytes - set as " + OPCODE_ACTION[opcode][1]); |
| 569 | |
| 570 | } |
| 571 | } |
| 572 | |
| 573 | /** |
| 574 | * This takes an instruction that has a narrow |
| 575 | * and a wide form for CPE access, and |
| 576 | * generates accordingly the right one. |
| 577 | * We assume the narrow instruction is what |
| 578 | * we were given, and that the wide form is |
| 579 | * the next possible instruction. |
| 580 | */ |
| 581 | void addInstrCPE(short opcode, int cpeNum) { |
| 582 | if (cpeNum < 256) { |
| 583 | addInstrU1(opcode, cpeNum); |
| 584 | } |
| 585 | else { |
| 586 | addInstrU2((short) (opcode+1), cpeNum); |
| 587 | } |
| 588 | } |
| 589 | |
| 590 | /** |
| 591 | * This takes an instruction that can be wrapped in |
| 592 | * a wide for large variable #s and does so. |
| 593 | */ |
| 594 | void addInstrWide(short opcode, int varNum) { |
| 595 | if (varNum < 256) { |
| 596 | addInstrU1(opcode, varNum); |
| 597 | } |
| 598 | else { |
| 599 | addInstr(VMOpcode.WIDE); |
| 600 | addInstrU2(opcode, varNum); |
| 601 | } |
| 602 | } |
| 603 | |
| 604 | /** |
| 605 | * For adding an instruction with 3 operands, a U2 and two U1's. |
| 606 | * So far, this is used by VMOpcode.INVOKEINTERFACE. |
| 607 | */ |
| 608 | void addInstrU2U1U1(short opcode, int operand1, short operand2, |
| 609 | short operand3) { |
| 610 | try { |
| 611 | cout.putU1(opcode); |
| 612 | cout.putU2(operand1); |
| 613 | cout.putU1(operand2); |
| 614 | cout.putU1(operand3); |
| 615 | } catch (IOException ioe) { |
| 616 | } |
| 617 | if (SanityManager.DEBUG) { |
| 618 | if (OPCODE_ACTION[opcode][1] != 5) |
| 619 | SanityManager.THROWASSERT("Opcode " + opcode + " incorrect entry in OPCODE_ACTION -" + |
| 620 | " writing 5 bytes - set as " + OPCODE_ACTION[opcode][1]); |
| 621 | } |
| 622 | } |
| 623 | |
| 624 | /** Get the current program counter */ |
| 625 | int getPC() { |
| 626 | return cout.size() + pcDelta; |
| 627 | } |
| 628 | |
| 629 | /** |
| 630 | * Return the complete instruction length for the |
| 631 | * passed in opcode. This will include the space for |
| 632 | * the opcode and its operand. |
| 633 | */ |
| 634 | private static int instructionLength(short opcode) |
| 635 | { |
| 636 | int instructionLength = OPCODE_ACTION[opcode][1]; |
| 637 | |
| 638 | if (SanityManager.DEBUG) |
| 639 | { |
| 640 | if (instructionLength < 0) |
| 641 | SanityManager.THROWASSERT("Opcode without instruction length " + opcode); |
| 642 | } |
| 643 | |
| 644 | return instructionLength; |
| 645 | } |
| 646 | |
| 647 | /** |
| 648 | * The delta between cout.size() and the pc. |
| 649 | * For an initial code chunk this is -8 (CODE_OFFSET) |
| 650 | * since 8 bytes are written. |
| 651 | * For a nested CodeChunk return by insertCodeSpace the delta |
| 652 | * corresponds to the original starting pc. |
| 653 | * @see #insertCodeSpace |
| 654 | */ |
| 655 | private final int pcDelta; |
| 656 | |
| 657 | CodeChunk() { |
| 658 | cout = new ClassFormatOutput(); |
| 659 | try { |
| 660 | cout.putU2(0); // max_stack, placeholder for now |
| 661 | cout.putU2(0); // max_locals, placeholder for now |
| 662 | cout.putU4(0); // code_length, placeholder 4 now |
| 663 | } catch (IOException ioe) { |
| 664 | } |
| 665 | pcDelta = - CodeChunk.CODE_OFFSET; |
| 666 | } |
| 667 | |
| 668 | /** |
| 669 | * Return a CodeChunk that has limited visibility into |
| 670 | * this CodeChunk. Used when a caller needs to insert instructions |
| 671 | * into an existing stream. |
| 672 | * @param pc |
| 673 | * @param byteCount |
| 674 | * @throws IOException |
| 675 | */ |
| 676 | private CodeChunk(CodeChunk main, int pc, int byteCount) |
| 677 | { |
| 678 | ArrayOutputStream aos = |
| 679 | new ArrayOutputStream(main.cout.getData()); |
| 680 | |
| 681 | try { |
| 682 | aos.setPosition(CODE_OFFSET + pc); |
| 683 | aos.setLimit(byteCount); |
| 684 | } catch (IOException e) { |
| 685 | } |
| 686 | |
| 687 | cout = new ClassFormatOutput(aos); |
| 688 | pcDelta = pc; |
| 689 | } |
| 690 | |
| 691 | private final ClassFormatOutput cout; |
| 692 | |
| 693 | /** |
| 694 | * now that we have codeBytes, fix the lengths fields in it |
| 695 | * to reflect what was stored. |
| 696 | * Limits checked here are from these sections of the JVM spec. |
| 697 | * <UL> |
| 698 | * <LI> 4.7.3 The Code Attribute |
| 699 | * <LI> 4.10 Limitations of the Java Virtual Machine |
| 700 | * </UL> |
| 701 | */ |
| 702 | private void fixLengths(BCMethod mb, int maxStack, int maxLocals, int codeLength) { |
| 703 | |
| 704 | byte[] codeBytes = cout.getData(); |
| 705 | |
| 706 | // max_stack is in bytes 0-1 |
| 707 | if (mb != null && maxStack > 65535) |
| 708 | mb.cb.addLimitExceeded(mb, "max_stack", 65535, maxStack); |
| 709 | |
| 710 | codeBytes[0] = (byte)(maxStack >> 8 ); |
| 711 | codeBytes[1] = (byte)(maxStack ); |
| 712 | |
| 713 | // max_locals is in bytes 2-3 |
| 714 | if (mb != null && maxLocals > 65535) |
| 715 | mb.cb.addLimitExceeded(mb, "max_locals", 65535, maxLocals); |
| 716 | codeBytes[2] = (byte)(maxLocals >> 8 ); |
| 717 | codeBytes[3] = (byte)(maxLocals ); |
| 718 | |
| 719 | // code_length is in bytes 4-7 |
| 720 | if (mb != null && codeLength > VMOpcode.MAX_CODE_LENGTH) |
| 721 | mb.cb.addLimitExceeded(mb, "code_length", |
| 722 | VMOpcode.MAX_CODE_LENGTH, codeLength); |
| 723 | codeBytes[4] = (byte)(codeLength >> 24 ); |
| 724 | codeBytes[5] = (byte)(codeLength >> 16 ); |
| 725 | codeBytes[6] = (byte)(codeLength >> 8 ); |
| 726 | codeBytes[7] = (byte)(codeLength ); |
| 727 | } |
| 728 | |
| 729 | /** |
| 730 | * wrap up the entry and stuff it in the class, |
| 731 | * now that it holds all of the instructions and |
| 732 | * the exception table. |
| 733 | */ |
| 734 | void complete(BCMethod mb, ClassHolder ch, |
| 735 | ClassMember method, int maxStack, int maxLocals) { |
| 736 | |
| 737 | int codeLength = getPC(); |
| 738 | |
| 739 | ClassFormatOutput out = cout; |
| 740 | |
| 741 | try { |
| 742 | |
| 743 | out.putU2(0); // exception_table_length |
| 744 | |
| 745 | if (SanityManager.DEBUG) { |
| 746 | if (SanityManager.DEBUG_ON("ClassLineNumbers")) { |
| 747 | // Add a single attribute - LineNumberTable |
| 748 | // This add fake line numbers that are the pc offset in the method. |
| 749 | out.putU2(1); // attributes_count |
| 750 | |
| 751 | int cpiUTF = ch.addUtf8("LineNumberTable"); |
| 752 | |
| 753 | out.putU2(cpiUTF); |
| 754 | out.putU4((codeLength * 4) + 2); |
| 755 | out.putU2(codeLength); |
| 756 | for (int i = 0; i < codeLength; i++) { |
| 757 | out.putU2(i); |
| 758 | out.putU2(i); |
| 759 | } |
| 760 | } else { |
| 761 | out.putU2(0); // attributes_count |
| 762 | } |
| 763 | |
| 764 | } else { |
| 765 | out.putU2(0); // attributes_count |
| 766 | // attributes is empty, a 0-element array. |
| 767 | } |
| 768 | } catch (IOException ioe) { |
| 769 | } |
| 770 | |
| 771 | fixLengths(mb, maxStack, maxLocals, codeLength); |
| 772 | method.addAttribute("Code", out); |
| 773 | |
| 774 | if (SanityManager.DEBUG) |
| 775 | { |
| 776 | // Only validate if the class file format is valid. |
| 777 | // Ok code length and guaranteed no errors building the class. |
| 778 | if ((codeLength <= VMOpcode.MAX_CODE_LENGTH) |
| 779 | && (mb != null && mb.cb.limitMsg == null)) |
| 780 | { |
| 781 | // Validate the alternate way to calculate the |
| 782 | // max stack agrees with the dynamic as the code |
| 783 | // is built way. |
| 784 | int walkedMaxStack = findMaxStack(ch, 0, codeLength); |
| 785 | if (walkedMaxStack != maxStack) |
| 786 | { |
| 787 | SanityManager.THROWASSERT("MAX STACK MISMATCH!! " + |
| 788 | maxStack + " <> " + walkedMaxStack); |
| 789 | } |
| 790 | } |
| 791 | } |
| 792 | |
| 793 | } |
| 794 | /** |
| 795 | * Return the opcode at the given pc. |
| 796 | */ |
| 797 | short getOpcode(int pc) |
| 798 | { |
| 799 | return (short) (cout.getData()[CODE_OFFSET + pc] & 0xff); |
| 800 | } |
| 801 | |
| 802 | /** |
| 803 | * Get the unsigned short value for the opcode at the program |
| 804 | * counter pc. |
| 805 | */ |
| 806 | private int getU2(int pc) |
| 807 | { |
| 808 | byte[] codeBytes = cout.getData(); |
| 809 | |
| 810 | int u2p = CODE_OFFSET + pc + 1; |
| 811 | |
| 812 | return ((codeBytes[u2p] & 0xff) << 8) | (codeBytes[u2p+1] & 0xff); |
| 813 | } |
| 814 | |
| 815 | /** |
| 816 | * Get the unsigned 32 bit value for the opcode at the program |
| 817 | * counter pc. |
| 818 | */ |
| 819 | private int getU4(int pc) |
| 820 | { |
| 821 | byte[] codeBytes = cout.getData(); |
| 822 | |
| 823 | int u4p = CODE_OFFSET + pc + 1; |
| 824 | |
| 825 | return (((codeBytes[u4p] & 0xff) << 24) | |
| 826 | ((codeBytes[u4p+1] & 0xff) << 16) | |
| 827 | ((codeBytes[u4p+2] & 0xff) << 8) | |
| 828 | ((codeBytes[u4p+3] & 0xff))); |
| 829 | } |
| 830 | /** |
| 831 | * Insert room for byteCount bytes after the instruction at pc |
| 832 | * and prepare to replace the instruction at pc. The instruction |
| 833 | * at pc is not modified by this call, space is allocated after it. |
| 834 | * The newly inserted space will be filled with NOP instructions. |
| 835 | * |
| 836 | * Returns a CodeChunk positioned at pc and available to write |
| 837 | * instructions upto (byteCode + length(existing instruction at pc) bytes. |
| 838 | * |
| 839 | * This chunk is left correctly positioned at the end of the code |
| 840 | * stream, ready to accept more code. Its pc will have increased by |
| 841 | * additionalBytes. |
| 842 | * |
| 843 | * It is the responsibility of the caller to patch up any |
| 844 | * branches or gotos. |
| 845 | * |
| 846 | * @param pc |
| 847 | * @param additionalBytes |
| 848 | */ |
| 849 | CodeChunk insertCodeSpace(int pc, int additionalBytes) |
| 850 | { |
| 851 | short existingOpcode = getOpcode(pc); |
| 852 | |
| 853 | int lengthOfExistingInstruction |
| 854 | = instructionLength(existingOpcode); |
| 855 | |
| 856 | |
| 857 | if (additionalBytes > 0) |
| 858 | { |
| 859 | // Size of the current code after this pc. |
| 860 | int sizeToMove = (getPC() - pc) - lengthOfExistingInstruction; |
| 861 | |
| 862 | // Increase the code by the number of bytes to be |
| 863 | // inserted. These NOPs will be overwritten by the |
| 864 | // moved code by the System.arraycopy below. |
| 865 | // It's assumed that the number of inserted bytes |
| 866 | // is small, one or two instructions worth, so it |
| 867 | // won't be a performance issue. |
| 868 | for (int i = 0; i < additionalBytes; i++) |
| 869 | addInstr(VMOpcode.NOP); |
| 870 | |
| 871 | // Must get codeBytes here as the array might have re-sized. |
| 872 | byte[] codeBytes = cout.getData(); |
| 873 | |
| 874 | int byteOffset = CODE_OFFSET + pc + lengthOfExistingInstruction; |
| 875 | |
| 876 | |
| 877 | // Shift the existing code stream down |
| 878 | System.arraycopy( |
| 879 | codeBytes, byteOffset, |
| 880 | codeBytes, byteOffset + additionalBytes, |
| 881 | sizeToMove); |
| 882 | |
| 883 | // Place NOPs in the space just freed by the move. |
| 884 | // This is not required, it ias assumed the caller |
| 885 | // will overwrite all the bytes they requested, but |
| 886 | // to be safe fill in with NOPs rather than leaving code |
| 887 | // that could break the verifier. |
| 888 | Arrays.fill(codeBytes, byteOffset, byteOffset + additionalBytes, |
| 889 | (byte) VMOpcode.NOP); |
| 890 | } |
| 891 | |
| 892 | // The caller must overwrite the original instruction |
| 893 | // at pc, thus increase the range of the limit stream |
| 894 | // created to include those bytes. |
| 895 | additionalBytes += lengthOfExistingInstruction; |
| 896 | |
| 897 | // Now the caller needs to fill in the instructions |
| 898 | // that make up the modified byteCount bytes of bytecode stream. |
| 899 | // Return a CodeChunk that can be used for this and |
| 900 | // is limited to only those bytes. |
| 901 | // The pc of the original code chunk is left unchanged. |
| 902 | |
| 903 | return new CodeChunk(this, pc, additionalBytes); |
| 904 | |
| 905 | } |
| 906 | |
| 907 | /* |
| 908 | * * Methods related to splitting the byte code chunks into sections that |
| 909 | * fit in the JVM's limits for a single method. |
| 910 | */ |
| 911 | |
| 912 | /** |
| 913 | * For a block of byte code starting at program counter pc for codeLength |
| 914 | * bytes return the maximum stack value, assuming a initial stack depth of |
| 915 | * zero. |
| 916 | */ |
| 917 | private int findMaxStack(ClassHolder ch, int pc, int codeLength) { |
| 918 | |
| 919 | int endPc = pc + codeLength; |
| 920 | int stack = 0; |
| 921 | int maxStack = 0; |
| 922 | |
| 923 | for (; pc < endPc;) { |
| 924 | |
| 925 | short opcode = getOpcode(pc); |
| 926 | |
| 927 | |
| 928 | int stackDelta = stackWordDelta(ch, pc, opcode); |
| 929 | |
| 930 | stack += stackDelta; |
| 931 | if (stack > maxStack) |
| 932 | maxStack = stack; |
| 933 | |
| 934 | int[] cond_pcs = findConditionalPCs(pc, opcode); |
| 935 | if (cond_pcs != null) { |
| 936 | // an else block exists. |
| 937 | if (cond_pcs[3] != -1) { |
| 938 | int blockMaxStack = findMaxStack(ch, cond_pcs[1], |
| 939 | cond_pcs[2]); |
| 940 | if ((stack + blockMaxStack) > maxStack) |
| 941 | maxStack = stack + blockMaxStack; |
| 942 | |
| 943 | pc = cond_pcs[3]; |
| 944 | continue; |
| 945 | } |
| 946 | } |
| 947 | |
| 948 | pc += instructionLength(opcode); |
| 949 | } |
| 950 | |
| 951 | return maxStack; |
| 952 | } |
| 953 | |
| 954 | /** |
| 955 | * Return the number of stack words pushed (positive) or popped (negative) |
| 956 | * by this instruction. |
| 957 | */ |
| 958 | private int stackWordDelta(ClassHolder ch, int pc, short opcode) { |
| 959 | if (SanityManager.DEBUG) { |
| 960 | // this validates the OPCODE_ACTION entry |
| 961 | instructionLength(opcode); |
| 962 | } |
| 963 | |
| 964 | int stackDelta = OPCODE_ACTION[opcode][0]; |
| 965 | if (stackDelta == VARIABLE_STACK) { |
| 966 | stackDelta = getVariableStackDelta(ch, pc, opcode); |
| 967 | } |
| 968 | |
| 969 | return stackDelta; |
| 970 | } |
| 971 | |
| 972 | /** |
| 973 | * Get the type descriptor in the virtual machine format for the type |
| 974 | * defined by the constant pool index for the instruction at pc. |
| 975 | */ |
| 976 | private String getTypeDescriptor(ClassHolder ch, int pc) { |
| 977 | int cpi = getU2(pc); |
| 978 | |
| 979 | // Field reference or method reference |
| 980 | CONSTANT_Index_info cii = (CONSTANT_Index_info) ch.getEntry(cpi); |
| 981 | |
| 982 | // NameAndType reference |
| 983 | int nameAndType = cii.getI2(); |
| 984 | cii = (CONSTANT_Index_info) ch.getEntry(nameAndType); |
| 985 | |
| 986 | // UTF8 descriptor |
| 987 | int descriptor = cii.getI2(); |
| 988 | CONSTANT_Utf8_info type = (CONSTANT_Utf8_info) ch.getEntry(descriptor); |
| 989 | |
| 990 | String vmDescriptor = type.toString(); |
| 991 | |
| 992 | return vmDescriptor; |
| 993 | } |
| 994 | |
| 995 | /** |
| 996 | * Get the word count for a type descriptor in the format of the virual |
| 997 | * machine. For a method this returns the the word count for the return |
| 998 | * type. |
| 999 | */ |
| 1000 | private static int getDescriptorWordCount(String vmDescriptor) { |
| 1001 | |
| 1002 | int width; |
| 1003 | if (VMDescriptor.DOUBLE.equals(vmDescriptor)) |
| 1004 | width = 2; |
| 1005 | else if (VMDescriptor.LONG.equals(vmDescriptor)) |
| 1006 | width = 2; |
| 1007 | else if (vmDescriptor.charAt(0) == VMDescriptor.C_METHOD) { |
| 1008 | switch (vmDescriptor.charAt(vmDescriptor.length() - 1)) { |
| 1009 | case VMDescriptor.C_DOUBLE: |
| 1010 | case VMDescriptor.C_LONG: |
| 1011 | width = 2; |
| 1012 | break; |
| 1013 | case VMDescriptor.C_VOID: |
| 1014 | width = 0; |
| 1015 | break; |
| 1016 | default: |
| 1017 | width = 1; |
| 1018 | break; |
| 1019 | } |
| 1020 | } else |
| 1021 | width = 1; |
| 1022 | |
| 1023 | return width; |
| 1024 | } |
| 1025 | |
| 1026 | /** |
| 1027 | * Get the number of words pushed (positive) or popped (negative) by this |
| 1028 | * instruction. The instruction is a get/put field or a method call, thus |
| 1029 | * the size of the words is defined by the field or method being access. |
| 1030 | */ |
| 1031 | private int getVariableStackDelta(ClassHolder ch, int pc, int opcode) { |
| 1032 | String vmDescriptor = getTypeDescriptor(ch, pc); |
| 1033 | int width = CodeChunk.getDescriptorWordCount(vmDescriptor); |
| 1034 | |
| 1035 | int stackDelta = 0; |
| 1036 | // Stack delta depends on context. |
| 1037 | switch (opcode) { |
| 1038 | case VMOpcode.GETSTATIC: |
| 1039 | stackDelta = width; |
| 1040 | break; |
| 1041 | |
| 1042 | case VMOpcode.GETFIELD: |
| 1043 | stackDelta = width - 1; // one for popped object ref |
| 1044 | break; |
| 1045 | |
| 1046 | case VMOpcode.PUTSTATIC: |
| 1047 | stackDelta = -width; |
| 1048 | break; |
| 1049 | |
| 1050 | case VMOpcode.PUTFIELD: |
| 1051 | stackDelta = -width - 1; // one for pop object ref |
| 1052 | break; |
| 1053 | |
| 1054 | case VMOpcode.INVOKEVIRTUAL: |
| 1055 | case VMOpcode.INVOKESPECIAL: |
| 1056 | stackDelta = -1; // for instance reference for method call. |
| 1057 | case VMOpcode.INVOKESTATIC: |
| 1058 | stackDelta += (width - CodeChunk.parameterWordCount(vmDescriptor)); |
| 1059 | // System.out.println("invoked non-interface " + stackDelta); |
| 1060 | break; |
| 1061 | |
| 1062 | case VMOpcode.INVOKEINTERFACE: |
| 1063 | // third byte contains the number of arguments to be popped |
| 1064 | stackDelta = width - getOpcode(pc + 3); |
| 1065 | // System.out.println("invoked interface " + stackDelta); |
| 1066 | break; |
| 1067 | default: |
| 1068 | System.out.println("WHO IS THIS "); |
| 1069 | break; |
| 1070 | |
| 1071 | } |
| 1072 | |
| 1073 | return stackDelta; |
| 1074 | } |
| 1075 | |
| 1076 | /** |
| 1077 | * Calculate the number of stack words in the arguments pushed for this |
| 1078 | * method descriptor. |
| 1079 | */ |
| 1080 | private static int parameterWordCount(String methodDescriptor) { |
| 1081 | int wordCount = 0; |
| 1082 | for (int i = 1;; i++) { |
| 1083 | switch (methodDescriptor.charAt(i)) { |
| 1084 | case VMDescriptor.C_ENDMETHOD: |
| 1085 | return wordCount; |
| 1086 | case VMDescriptor.C_DOUBLE: |
| 1087 | case VMDescriptor.C_LONG: |
| 1088 | wordCount += 2; |
| 1089 | break; |
| 1090 | case VMDescriptor.C_ARRAY: |
| 1091 | // skip while there are array symbols. |
| 1092 | do { |
| 1093 | i++; |
| 1094 | } while (methodDescriptor.charAt(i) == VMDescriptor.C_ARRAY); |
| 1095 | if (methodDescriptor.charAt(i) != VMDescriptor.C_CLASS) { |
| 1096 | // an array is a reference, even an array of doubles. |
| 1097 | wordCount += 1; |
| 1098 | break; |
| 1099 | } |
| 1100 | |
| 1101 | // fall through to skip the Lclassname; after the array. |
| 1102 | |
| 1103 | case VMDescriptor.C_CLASS: |
| 1104 | // skip until ; |
| 1105 | do { |
| 1106 | i++; |
| 1107 | } while (methodDescriptor.charAt(i) != VMDescriptor.C_ENDCLASS); |
| 1108 | wordCount += 1; |
| 1109 | break; |
| 1110 | default: |
| 1111 | wordCount += 1; |
| 1112 | break; |
| 1113 | } |
| 1114 | } |
| 1115 | } |
| 1116 | |
| 1117 | /** |
| 1118 | * Find the limits of a conditional block starting at the instruction with |
| 1119 | * the given opcode at the program counter pc. |
| 1120 | * <P> |
| 1121 | * Returns a six element integer array of program counters and lengths. |
| 1122 | * <code. [0] - program counter of the IF opcode (passed in as pc) [1] - |
| 1123 | * program counter of the start of the then block [2] - length of the then |
| 1124 | * block [3] - program counter of the else block, -1 if no else block |
| 1125 | * exists. [4] - length of of the else block, -1 if no else block exists. |
| 1126 | * [5] - program counter of the common end point. </code> |
| 1127 | * |
| 1128 | * Looks for and handles conditionals that are written by the Conditional |
| 1129 | * class. |
| 1130 | * |
| 1131 | * @return Null if the opcode is not the start of a conditional otherwise |
| 1132 | * the array of values. |
| 1133 | */ |
| 1134 | private int[] findConditionalPCs(int pc, short opcode) { |
| 1135 | switch (opcode) { |
| 1136 | default: |
| 1137 | return null; |
| 1138 | case VMOpcode.IFNONNULL: |
| 1139 | case VMOpcode.IFNULL: |
| 1140 | case VMOpcode.IFEQ: |
| 1141 | case VMOpcode.IFNE: |
| 1142 | break; |
| 1143 | } |
| 1144 | |
| 1145 | int then_pc; |
| 1146 | int else_pc; |
| 1147 | int if_off = getU2(pc); |
| 1148 | |
| 1149 | if ((if_off == 8) |
| 1150 | && (getOpcode(pc + VMOpcode.IF_INS_LENGTH) == VMOpcode.GOTO_W)) { |
| 1151 | // 32 bit branch |
| 1152 | then_pc = pc + VMOpcode.IF_INS_LENGTH + VMOpcode.GOTO_W_INS_LENGTH; |
| 1153 | |
| 1154 | // Get else PC from the 32 bit offset within the GOTO_W |
| 1155 | // instruction remembering to add it to the pc of that |
| 1156 | // instruction, not the original IF. |
| 1157 | else_pc = pc + VMOpcode.IF_INS_LENGTH |
| 1158 | + getU4(pc + VMOpcode.IF_INS_LENGTH); |
| 1159 | |
| 1160 | } else { |
| 1161 | then_pc = pc + VMOpcode.IF_INS_LENGTH; |
| 1162 | else_pc = pc + if_off; |
| 1163 | } |
| 1164 | |
| 1165 | // Need to look for the goto or goto_w at the |
| 1166 | // end of the then block. There might not be |
| 1167 | // one for the case when there is no else block. |
| 1168 | // In that case the then block will just run into |
| 1169 | // what we currently think the else pc. |
| 1170 | |
| 1171 | int end_pc = -1; |
| 1172 | for (int tpc = then_pc; tpc < else_pc;) { |
| 1173 | short opc = getOpcode(tpc); |
| 1174 | |
| 1175 | // need to handle conditionals |
| 1176 | int[] innerCond = findConditionalPCs(tpc, opc); |
| 1177 | if (innerCond != null) { |
| 1178 | // skip to the end of this conditional |
| 1179 | tpc = innerCond[5]; // end_pc |
| 1180 | continue; |
| 1181 | } |
| 1182 | |
| 1183 | if (opc == VMOpcode.GOTO) { |
| 1184 | // not at the end of the then block |
| 1185 | // so not our goto. Shouldn't see this |
| 1186 | // with the current code due to the |
| 1187 | // skipping of the conditional above. |
| 1188 | // But safe defensive programming. |
| 1189 | if (tpc != (else_pc - VMOpcode.GOTO_INS_LENGTH)) |
| 1190 | continue; |
| 1191 | |
| 1192 | end_pc = tpc + getU2(tpc); |
| 1193 | break; |
| 1194 | } else if (opc == VMOpcode.GOTO_W) { |
| 1195 | // not at the end of the then block |
| 1196 | // so not our goto. SHouldn't see this |
| 1197 | // with the current code due to the |
| 1198 | // skipping of the conditional above. |
| 1199 | // But safe defensive programming. |
| 1200 | if (tpc != (else_pc - VMOpcode.GOTO_W_INS_LENGTH)) |
| 1201 | continue; |
| 1202 | |
| 1203 | end_pc = tpc + getU4(tpc); |
| 1204 | break; |
| 1205 | |
| 1206 | } |
| 1207 | tpc += instructionLength(opc); |
| 1208 | } |
| 1209 | |
| 1210 | int else_len; |
| 1211 | int then_len; |
| 1212 | if (end_pc == -1) { |
| 1213 | // no else block; |
| 1214 | end_pc = else_pc; |
| 1215 | else_pc = -1; |
| 1216 | |
| 1217 | then_len = end_pc - then_pc; |
| 1218 | else_len = -1; |
| 1219 | } else { |
| 1220 | then_len = else_pc - then_pc; |
| 1221 | else_len = end_pc - else_pc; |
| 1222 | } |
| 1223 | |
| 1224 | int[] ret = new int[6]; |
| 1225 | |
| 1226 | ret[0] = pc; |
| 1227 | ret[1] = then_pc; |
| 1228 | ret[2] = then_len; |
| 1229 | ret[3] = else_pc; |
| 1230 | ret[4] = else_len; |
| 1231 | ret[5] = end_pc; |
| 1232 | |
| 1233 | return ret; |
| 1234 | } |
| 1235 | |
| 1236 | /** |
| 1237 | * Attempt to split the current method by pushing a chunk of |
| 1238 | * its code into a sub-method. The starting point of the split |
| 1239 | * (split_pc) must correspond to a stack depth of zero. It is the |
| 1240 | * reponsibility of the caller to ensure this. |
| 1241 | * Split is only made if there exists a chunk of code starting at |
| 1242 | * pc=split_pc, whose stack depth upon termination is zero. |
| 1243 | * The method will try to split a code section greater than |
| 1244 | * optimalMinLength but may split earlier if no such block exists. |
| 1245 | * <P> |
| 1246 | * The method is aimed at splitting methods that contain |
| 1247 | * many independent statements. |
| 1248 | * <P> |
| 1249 | * If a split is possible this method will perform the split and |
| 1250 | * create a void sub method, and move the code into the sub-method |
| 1251 | * and setup this method to call the sub-method before continuing. |
| 1252 | * This method's max stack and current pc will be correctly set |
| 1253 | * as though the method had just been created. |
| 1254 | * |
| 1255 | * @param mb Method for this chunk. |
| 1256 | * @param ch Class definition |
| 1257 | * @param codeLength codeLength to check |
| 1258 | * @param optimalMinLength minimum length required for split |
| 1259 | */ |
| 1260 | final int splitZeroStack(BCMethod mb, ClassHolder ch, final int split_pc, |
| 1261 | final int codeLength, final int optimalMinLength) { |
| 1262 | int stack = 0; |
| 1263 | |
| 1264 | // maximum possible split seen that is less than |
| 1265 | // the minimum. |
| 1266 | int possibleSplitLength = -1; |
| 1267 | |
| 1268 | // do not split until at least this point (inclusive) |
| 1269 | // used to ensure no split occurs in the middle of |
| 1270 | // a conditional. |
| 1271 | int outerConditionalEnd_pc = -1; |
| 1272 | |
| 1273 | int end_pc = split_pc + codeLength; |
| 1274 | for (int pc = split_pc; pc < end_pc;) { |
| 1275 | |
| 1276 | short opcode = getOpcode(pc); |
| 1277 | |
| 1278 | int stackDelta = stackWordDelta(ch, pc, opcode); |
| 1279 | |
| 1280 | stack += stackDelta; |
| 1281 | |
| 1282 | // Cannot split a conditional but need to calculate |
| 1283 | // the stack depth at the end of the conditional. |
| 1284 | // Each path through the conditional will have the |
| 1285 | // same stack depth. |
| 1286 | int[] cond_pcs = findConditionalPCs(pc, opcode); |
| 1287 | if (cond_pcs != null) { |
| 1288 | // an else block exists, skip the then block. |
| 1289 | if (cond_pcs[3] != -1) { |
| 1290 | pc = cond_pcs[3]; |
| 1291 | continue; |
| 1292 | } |
| 1293 | |
| 1294 | if (SanityManager.DEBUG) { |
| 1295 | if (outerConditionalEnd_pc != -1) { |
| 1296 | if (cond_pcs[5] >= outerConditionalEnd_pc) |
| 1297 | SanityManager.THROWASSERT("NESTED CONDITIONALS!"); |
| 1298 | } |
| 1299 | } |
| 1300 | |
| 1301 | if (outerConditionalEnd_pc == -1) { |
| 1302 | outerConditionalEnd_pc = cond_pcs[5]; |
| 1303 | } |
| 1304 | } |
| 1305 | |
| 1306 | pc += instructionLength(opcode); |
| 1307 | |
| 1308 | // Don't split in the middle of a conditional |
| 1309 | if (outerConditionalEnd_pc != -1) { |
| 1310 | if (pc > outerConditionalEnd_pc) { |
| 1311 | // passed the outermost conditional |
| 1312 | outerConditionalEnd_pc = -1; |
| 1313 | } |
| 1314 | continue; |
| 1315 | } |
| 1316 | |
| 1317 | if (stack != 0) |
| 1318 | continue; |
| 1319 | |
| 1320 | int splitLength = pc - split_pc; |
| 1321 | |
| 1322 | if (splitLength < optimalMinLength) { |
| 1323 | // record we do have a possible split. |
| 1324 | possibleSplitLength = splitLength; |
| 1325 | continue; |
| 1326 | } |
| 1327 | |
| 1328 | // no point splitting to a method bigger |
| 1329 | // than the VM can handle. Save one for |
| 1330 | // return instruction. |
| 1331 | if (splitLength > BCMethod.CODE_SPLIT_LENGTH - 1) { |
| 1332 | if (possibleSplitLength == -1) |
| 1333 | return -1; |
| 1334 | |
| 1335 | // Decide if the earlier possible split is |
| 1336 | // worth it. 100 is an arbitary number, |
| 1337 | // a real low limit would be the number of |
| 1338 | // bytes of instructions required to call |
| 1339 | // the sub-method, four I think. |
| 1340 | if (possibleSplitLength < 100) |
| 1341 | return -1; |
| 1342 | |
| 1343 | // OK go with the earlier split |
| 1344 | splitLength = possibleSplitLength; |
| 1345 | |
| 1346 | } |
| 1347 | |
| 1348 | // Yes, we can split this big method into a smaller method!! |
| 1349 | |
| 1350 | BCMethod subMethod = startSubMethod(mb, "void", split_pc, |
| 1351 | splitLength); |
| 1352 | |
| 1353 | CodeChunk subChunk = subMethod.myCode; |
| 1354 | |
| 1355 | byte[] codeBytes = cout.getData(); |
| 1356 | |
| 1357 | // the code to be moved into the sub method |
| 1358 | // as a block. This will correctly increase the |
| 1359 | // program counter. |
| 1360 | try { |
| 1361 | subChunk.cout.write(codeBytes, CODE_OFFSET + split_pc, |
| 1362 | splitLength); |
| 1363 | } catch (IOException ioe) { |
| 1364 | // writing to a byte array |
| 1365 | } |
| 1366 | |
| 1367 | // Just cause the sub-method to return, |
| 1368 | // fix up its maxStack and then complete it. |
| 1369 | subChunk.addInstr(VMOpcode.RETURN); |
| 1370 | subMethod.maxStack = subChunk.findMaxStack(ch, 0, subChunk.getPC()); |
| 1371 | subMethod.complete(); |
| 1372 | |
| 1373 | return removePushedCode(mb, ch, subMethod, split_pc, splitLength, |
| 1374 | codeLength); |
| 1375 | } |
| 1376 | return -1; |
| 1377 | } |
| 1378 | |
| 1379 | /** |
| 1380 | * Start a sub method that we will split the portion of our current code to, |
| 1381 | * starting from start_pc and including codeLength bytes of code. |
| 1382 | * |
| 1383 | * Return a BCMethod obtained from BCMethod.getNewSubMethod with the passed |
| 1384 | * in return type and same parameters as mb if the code block to be moved |
| 1385 | * uses parameters. |
| 1386 | */ |
| 1387 | private BCMethod startSubMethod(BCMethod mb, String returnType, |
| 1388 | int split_pc, int codeLength) { |
| 1389 | |
| 1390 | boolean needParameters = usesParameters(mb, split_pc, codeLength); |
| 1391 | |
| 1392 | return mb.getNewSubMethod(returnType, needParameters); |
| 1393 | } |
| 1394 | |
| 1395 | /** |
| 1396 | * Does a section of code use parameters. |
| 1397 | * Any load, exception ALOAD_0 in an instance method, is |
| 1398 | * seen as using parameters, as this complete byte code |
| 1399 | * implementation does not use local variables. |
| 1400 | * |
| 1401 | */ |
| 1402 | private boolean usesParameters(BCMethod mb, int pc, int codeLength) { |
| 1403 | |
| 1404 | // does the method even have parameters? |
| 1405 | if (mb.parameters == null) |
| 1406 | return false; |
| 1407 | |
| 1408 | boolean isStatic = (mb.myEntry.getModifier() & Modifier.STATIC) != 0; |
| 1409 | |
| 1410 | int endPc = pc + codeLength; |
| 1411 | |
| 1412 | for (; pc < endPc;) { |
| 1413 | short opcode = getOpcode(pc); |
| 1414 | switch (opcode) { |
| 1415 | case VMOpcode.ILOAD_0: |
| 1416 | case VMOpcode.LLOAD_0: |
| 1417 | case VMOpcode.FLOAD_0: |
| 1418 | case VMOpcode.DLOAD_0: |
| 1419 | return true; |
| 1420 | |
| 1421 | case VMOpcode.ALOAD_0: |
| 1422 | if (isStatic) |
| 1423 | return true; |
| 1424 | break; |
| 1425 | |
| 1426 | case VMOpcode.ILOAD_1: |
| 1427 | case VMOpcode.LLOAD_1: |
| 1428 | case VMOpcode.FLOAD_1: |
| 1429 | case VMOpcode.DLOAD_1: |
| 1430 | case VMOpcode.ALOAD_1: |
| 1431 | return true; |
| 1432 | |
| 1433 | case VMOpcode.ILOAD_2: |
| 1434 | case VMOpcode.LLOAD_2: |
| 1435 | case VMOpcode.FLOAD_2: |
| 1436 | case VMOpcode.DLOAD_2: |
| 1437 | case VMOpcode.ALOAD_2: |
| 1438 | return true; |
| 1439 | |
| 1440 | case VMOpcode.ILOAD_3: |
| 1441 | case VMOpcode.LLOAD_3: |
| 1442 | case VMOpcode.FLOAD_3: |
| 1443 | case VMOpcode.DLOAD_3: |
| 1444 | case VMOpcode.ALOAD_3: |
| 1445 | return true; |
| 1446 | |
| 1447 | case VMOpcode.ILOAD: |
| 1448 | case VMOpcode.LLOAD: |
| 1449 | case VMOpcode.FLOAD: |
| 1450 | case VMOpcode.DLOAD: |
| 1451 | case VMOpcode.ALOAD: |
| 1452 | return true; |
| 1453 | default: |
| 1454 | break; |
| 1455 | |
| 1456 | } |
| 1457 | pc += instructionLength(opcode); |
| 1458 | } |
| 1459 | return false; |
| 1460 | } |
| 1461 | |
| 1462 | /** |
| 1463 | * Remove a block of code from this method that was |
| 1464 | * pushed into a sub-method and call the sub-method. |
| 1465 | * |
| 1466 | * Returns the pc of this method just after the call |
| 1467 | * to the sub-method. |
| 1468 | |
| 1469 | * @param mb My method |
| 1470 | * @param ch My class |
| 1471 | * @param subMethod Sub-method code was pushed into |
| 1472 | * @param split_pc Program counter the split started at |
| 1473 | * @param splitLength Length of code split |
| 1474 | * @param codeLength Length of code before split |
| 1475 | */ |
| 1476 | private int removePushedCode(BCMethod mb, ClassHolder ch, |
| 1477 | BCMethod subMethod, int split_pc, int splitLength, int codeLength) { |
| 1478 | // now need to fix up this method, create |
| 1479 | // a new CodeChunk just to be clearer than |
| 1480 | // trying to modify this chunk directly. |
| 1481 | CodeChunk replaceChunk = new CodeChunk(); |
| 1482 | mb.myCode = replaceChunk; |
| 1483 | mb.maxStack = 0; |
| 1484 | |
| 1485 | byte[] codeBytes = cout.getData(); |
| 1486 | |
| 1487 | // write any existing code before the split point |
| 1488 | // into the replacement chunk. |
| 1489 | if (split_pc != 0) { |
| 1490 | try { |
| 1491 | replaceChunk.cout.write(codeBytes, CODE_OFFSET, split_pc); |
| 1492 | } catch (IOException ioe) { |
| 1493 | // writing to a byte array |
| 1494 | } |
| 1495 | } |
| 1496 | |
| 1497 | // Call the sub method, will write into replaceChunk. |
| 1498 | mb.callSubMethod(subMethod); |
| 1499 | |
| 1500 | int postSplit_pc = replaceChunk.getPC(); |
| 1501 | |
| 1502 | // Write the code remaining in this method into the replacement chunk |
| 1503 | |
| 1504 | int remainingCodeLength = codeLength - splitLength; |
| 1505 | try { |
| 1506 | replaceChunk.cout.write(codeBytes, CODE_OFFSET + split_pc |
| 1507 | + splitLength, remainingCodeLength); |
| 1508 | } catch (IOException ioe) { |
| 1509 | // writing to a byte array |
| 1510 | } |
| 1511 | |
| 1512 | mb.maxStack = replaceChunk.findMaxStack(ch, 0, replaceChunk.getPC()); |
| 1513 | |
| 1514 | return postSplit_pc; |
| 1515 | } |
| 1516 | } |