1 /* 2 * Copyright (c) 1998, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "gc/shared/gcLocker.hpp" 27 #include "interpreter/bytecodes.hpp" 28 #include "interpreter/interpreter.hpp" 29 #include "interpreter/rewriter.hpp" 30 #include "memory/metaspaceShared.hpp" 31 #include "memory/resourceArea.hpp" 32 #include "oops/generateOopMap.hpp" 33 #include "prims/methodHandles.hpp" 34 35 // Computes a CPC map (new_index -> original_index) for constant pool entries 36 // that are referred to by the interpreter at runtime via the constant pool cache. 37 // Also computes a CP map (original_index -> new_index). 38 // Marks entries in CP which require additional processing. 39 void Rewriter::compute_index_maps() { 40 const int length = _pool->length(); 41 init_maps(length); 42 bool saw_mh_symbol = false; 43 for (int i = 0; i < length; i++) { 44 int tag = _pool->tag_at(i).value(); 45 switch (tag) { 46 case JVM_CONSTANT_InterfaceMethodref: 47 case JVM_CONSTANT_Fieldref : // fall through 48 case JVM_CONSTANT_Methodref : // fall through 49 add_cp_cache_entry(i); 50 break; 51 case JVM_CONSTANT_String: 52 case JVM_CONSTANT_MethodHandle : // fall through 53 case JVM_CONSTANT_MethodType : // fall through 54 add_resolved_references_entry(i); 55 break; 56 case JVM_CONSTANT_Utf8: 57 if (_pool->symbol_at(i) == vmSymbols::java_lang_invoke_MethodHandle() || 58 _pool->symbol_at(i) == vmSymbols::java_lang_invoke_VarHandle()) { 59 saw_mh_symbol = true; 60 } 61 break; 62 } 63 } 64 65 // Record limits of resolved reference map for constant pool cache indices 66 record_map_limits(); 67 68 guarantee((int) _cp_cache_map.length() - 1 <= (int) ((u2)-1), 69 "all cp cache indexes fit in a u2"); 70 71 if (saw_mh_symbol) { 72 _method_handle_invokers.at_grow(length, 0); 73 } 74 } 75 76 // Unrewrite the bytecodes if an error occurs. 77 void Rewriter::restore_bytecodes() { 78 int len = _methods->length(); 79 bool invokespecial_error = false; 80 81 for (int i = len-1; i >= 0; i--) { 82 Method* method = _methods->at(i); 83 scan_method(method, true, &invokespecial_error); 84 assert(!invokespecial_error, "reversing should not get an invokespecial error"); 85 } 86 } 87 88 // Creates a constant pool cache given a CPC map 89 void Rewriter::make_constant_pool_cache(TRAPS) { 90 ClassLoaderData* loader_data = _pool->pool_holder()->class_loader_data(); 91 ConstantPoolCache* cache = 92 ConstantPoolCache::allocate(loader_data, _cp_cache_map, 93 _invokedynamic_cp_cache_map, 94 _invokedynamic_references_map, CHECK); 95 96 // initialize object cache in constant pool 97 _pool->set_cache(cache); 98 cache->set_constant_pool(_pool()); 99 100 // _resolved_references is stored in pool->cache(), so need to be done after 101 // the above lines. 102 _pool->initialize_resolved_references(loader_data, _resolved_references_map, 103 _resolved_reference_limit, 104 CHECK); 105 } 106 107 108 109 // The new finalization semantics says that registration of 110 // finalizable objects must be performed on successful return from the 111 // Object.<init> constructor. We could implement this trivially if 112 // <init> were never rewritten but since JVMTI allows this to occur, a 113 // more complicated solution is required. A special return bytecode 114 // is used only by Object.<init> to signal the finalization 115 // registration point. Additionally local 0 must be preserved so it's 116 // available to pass to the registration function. For simplicity we 117 // require that local 0 is never overwritten so it's available as an 118 // argument for registration. 119 120 void Rewriter::rewrite_Object_init(methodHandle method, TRAPS) { 121 RawBytecodeStream bcs(method); 122 while (!bcs.is_last_bytecode()) { 123 Bytecodes::Code opcode = bcs.raw_next(); 124 switch (opcode) { 125 case Bytecodes::_return: *bcs.bcp() = Bytecodes::_return_register_finalizer; break; 126 127 case Bytecodes::_istore: 128 case Bytecodes::_lstore: 129 case Bytecodes::_fstore: 130 case Bytecodes::_dstore: 131 case Bytecodes::_astore: 132 if (bcs.get_index() != 0) continue; 133 134 // fall through 135 case Bytecodes::_istore_0: 136 case Bytecodes::_lstore_0: 137 case Bytecodes::_fstore_0: 138 case Bytecodes::_dstore_0: 139 case Bytecodes::_astore_0: 140 THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(), 141 "can't overwrite local 0 in Object.<init>"); 142 break; 143 } 144 } 145 } 146 147 148 // Rewrite a classfile-order CP index into a native-order CPC index. 149 void Rewriter::rewrite_member_reference(address bcp, int offset, bool reverse) { 150 address p = bcp + offset; 151 if (!reverse) { 152 int cp_index = Bytes::get_Java_u2(p); 153 int cache_index = cp_entry_to_cp_cache(cp_index); 154 Bytes::put_native_u2(p, cache_index); 155 if (!_method_handle_invokers.is_empty()) 156 maybe_rewrite_invokehandle(p - 1, cp_index, cache_index, reverse); 157 } else { 158 int cache_index = Bytes::get_native_u2(p); 159 int pool_index = cp_cache_entry_pool_index(cache_index); 160 Bytes::put_Java_u2(p, pool_index); 161 if (!_method_handle_invokers.is_empty()) 162 maybe_rewrite_invokehandle(p - 1, pool_index, cache_index, reverse); 163 } 164 } 165 166 // If the constant pool entry for invokespecial is InterfaceMethodref, 167 // we need to add a separate cpCache entry for its resolution, because it is 168 // different than the resolution for invokeinterface with InterfaceMethodref. 169 // These cannot share cpCache entries. 170 void Rewriter::rewrite_invokespecial(address bcp, int offset, bool reverse, bool* invokespecial_error) { 171 address p = bcp + offset; 172 if (!reverse) { 173 int cp_index = Bytes::get_Java_u2(p); 174 if (_pool->tag_at(cp_index).is_interface_method()) { 175 int cache_index = add_invokespecial_cp_cache_entry(cp_index); 176 if (cache_index != (int)(jushort) cache_index) { 177 *invokespecial_error = true; 178 } 179 Bytes::put_native_u2(p, cache_index); 180 } else { 181 rewrite_member_reference(bcp, offset, reverse); 182 } 183 } else { 184 rewrite_member_reference(bcp, offset, reverse); 185 } 186 } 187 188 189 // Adjust the invocation bytecode for a signature-polymorphic method (MethodHandle.invoke, etc.) 190 void Rewriter::maybe_rewrite_invokehandle(address opc, int cp_index, int cache_index, bool reverse) { 191 if (!reverse) { 192 if ((*opc) == (u1)Bytecodes::_invokevirtual || 193 // allow invokespecial as an alias, although it would be very odd: 194 (*opc) == (u1)Bytecodes::_invokespecial) { 195 assert(_pool->tag_at(cp_index).is_method(), "wrong index"); 196 // Determine whether this is a signature-polymorphic method. 197 if (cp_index >= _method_handle_invokers.length()) return; 198 int status = _method_handle_invokers.at(cp_index); 199 assert(status >= -1 && status <= 1, "oob tri-state"); 200 if (status == 0) { 201 if (_pool->klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_MethodHandle() && 202 MethodHandles::is_signature_polymorphic_name(SystemDictionary::MethodHandle_klass(), 203 _pool->name_ref_at(cp_index))) { 204 // we may need a resolved_refs entry for the appendix 205 add_invokedynamic_resolved_references_entries(cp_index, cache_index); 206 status = +1; 207 } else if (_pool->klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_VarHandle() && 208 MethodHandles::is_signature_polymorphic_name(SystemDictionary::VarHandle_klass(), 209 _pool->name_ref_at(cp_index))) { 210 // we may need a resolved_refs entry for the appendix 211 add_invokedynamic_resolved_references_entries(cp_index, cache_index); 212 status = +1; 213 } else { 214 status = -1; 215 } 216 _method_handle_invokers.at(cp_index) = status; 217 } 218 // We use a special internal bytecode for such methods (if non-static). 219 // The basic reason for this is that such methods need an extra "appendix" argument 220 // to transmit the call site's intended call type. 221 if (status > 0) { 222 (*opc) = (u1)Bytecodes::_invokehandle; 223 } 224 } 225 } else { 226 // Do not need to look at cp_index. 227 if ((*opc) == (u1)Bytecodes::_invokehandle) { 228 (*opc) = (u1)Bytecodes::_invokevirtual; 229 // Ignore corner case of original _invokespecial instruction. 230 // This is safe because (a) the signature polymorphic method was final, and 231 // (b) the implementation of MethodHandle will not call invokespecial on it. 232 } 233 } 234 } 235 236 237 void Rewriter::rewrite_invokedynamic(address bcp, int offset, bool reverse) { 238 address p = bcp + offset; 239 assert(p[-1] == Bytecodes::_invokedynamic, "not invokedynamic bytecode"); 240 if (!reverse) { 241 int cp_index = Bytes::get_Java_u2(p); 242 int cache_index = add_invokedynamic_cp_cache_entry(cp_index); 243 int resolved_index = add_invokedynamic_resolved_references_entries(cp_index, cache_index); 244 // Replace the trailing four bytes with a CPC index for the dynamic 245 // call site. Unlike other CPC entries, there is one per bytecode, 246 // not just one per distinct CP entry. In other words, the 247 // CPC-to-CP relation is many-to-one for invokedynamic entries. 248 // This means we must use a larger index size than u2 to address 249 // all these entries. That is the main reason invokedynamic 250 // must have a five-byte instruction format. (Of course, other JVM 251 // implementations can use the bytes for other purposes.) 252 // Note: We use native_u4 format exclusively for 4-byte indexes. 253 Bytes::put_native_u4(p, ConstantPool::encode_invokedynamic_index(cache_index)); 254 // add the bcp in case we need to patch this bytecode if we also find a 255 // invokespecial/InterfaceMethodref in the bytecode stream 256 _patch_invokedynamic_bcps->push(p); 257 _patch_invokedynamic_refs->push(resolved_index); 258 } else { 259 int cache_index = ConstantPool::decode_invokedynamic_index( 260 Bytes::get_native_u4(p)); 261 // We will reverse the bytecode rewriting _after_ adjusting them. 262 // Adjust the cache index by offset to the invokedynamic entries in the 263 // cpCache plus the delta if the invokedynamic bytecodes were adjusted. 264 int adjustment = cp_cache_delta() + _first_iteration_cp_cache_limit; 265 int cp_index = invokedynamic_cp_cache_entry_pool_index(cache_index - adjustment); 266 assert(_pool->tag_at(cp_index).is_invoke_dynamic(), "wrong index"); 267 // zero out 4 bytes 268 Bytes::put_Java_u4(p, 0); 269 Bytes::put_Java_u2(p, cp_index); 270 } 271 } 272 273 void Rewriter::patch_invokedynamic_bytecodes() { 274 // If the end of the cp_cache is the same as after initializing with the 275 // cpool, nothing needs to be done. Invokedynamic bytecodes are at the 276 // correct offsets. ie. no invokespecials added 277 int delta = cp_cache_delta(); 278 if (delta > 0) { 279 int length = _patch_invokedynamic_bcps->length(); 280 assert(length == _patch_invokedynamic_refs->length(), 281 "lengths should match"); 282 for (int i = 0; i < length; i++) { 283 address p = _patch_invokedynamic_bcps->at(i); 284 int cache_index = ConstantPool::decode_invokedynamic_index( 285 Bytes::get_native_u4(p)); 286 Bytes::put_native_u4(p, ConstantPool::encode_invokedynamic_index(cache_index + delta)); 287 288 // invokedynamic resolved references map also points to cp cache and must 289 // add delta to each. 290 int resolved_index = _patch_invokedynamic_refs->at(i); 291 for (int entry = 0; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) { 292 assert(_invokedynamic_references_map.at(resolved_index + entry) == cache_index, 293 "should be the same index"); 294 _invokedynamic_references_map.at_put(resolved_index+entry, 295 cache_index + delta); 296 } 297 } 298 } 299 } 300 301 302 // Rewrite some ldc bytecodes to _fast_aldc 303 void Rewriter::maybe_rewrite_ldc(address bcp, int offset, bool is_wide, 304 bool reverse) { 305 if (!reverse) { 306 assert((*bcp) == (is_wide ? Bytecodes::_ldc_w : Bytecodes::_ldc), "not ldc bytecode"); 307 address p = bcp + offset; 308 int cp_index = is_wide ? Bytes::get_Java_u2(p) : (u1)(*p); 309 constantTag tag = _pool->tag_at(cp_index).value(); 310 if (tag.is_method_handle() || tag.is_method_type() || tag.is_string()) { 311 int ref_index = cp_entry_to_resolved_references(cp_index); 312 if (is_wide) { 313 (*bcp) = Bytecodes::_fast_aldc_w; 314 assert(ref_index == (u2)ref_index, "index overflow"); 315 Bytes::put_native_u2(p, ref_index); 316 } else { 317 (*bcp) = Bytecodes::_fast_aldc; 318 assert(ref_index == (u1)ref_index, "index overflow"); 319 (*p) = (u1)ref_index; 320 } 321 } 322 } else { 323 Bytecodes::Code rewritten_bc = 324 (is_wide ? Bytecodes::_fast_aldc_w : Bytecodes::_fast_aldc); 325 if ((*bcp) == rewritten_bc) { 326 address p = bcp + offset; 327 int ref_index = is_wide ? Bytes::get_native_u2(p) : (u1)(*p); 328 int pool_index = resolved_references_entry_to_pool_index(ref_index); 329 if (is_wide) { 330 (*bcp) = Bytecodes::_ldc_w; 331 assert(pool_index == (u2)pool_index, "index overflow"); 332 Bytes::put_Java_u2(p, pool_index); 333 } else { 334 (*bcp) = Bytecodes::_ldc; 335 assert(pool_index == (u1)pool_index, "index overflow"); 336 (*p) = (u1)pool_index; 337 } 338 } 339 } 340 } 341 342 343 // Rewrites a method given the index_map information 344 void Rewriter::scan_method(Method* method, bool reverse, bool* invokespecial_error) { 345 346 int nof_jsrs = 0; 347 bool has_monitor_bytecodes = false; 348 349 { 350 // We cannot tolerate a GC in this block, because we've 351 // cached the bytecodes in 'code_base'. If the Method* 352 // moves, the bytecodes will also move. 353 NoSafepointVerifier nsv; 354 Bytecodes::Code c; 355 356 // Bytecodes and their length 357 const address code_base = method->code_base(); 358 const int code_length = method->code_size(); 359 360 int bc_length; 361 for (int bci = 0; bci < code_length; bci += bc_length) { 362 address bcp = code_base + bci; 363 int prefix_length = 0; 364 c = (Bytecodes::Code)(*bcp); 365 366 // Since we have the code, see if we can get the length 367 // directly. Some more complicated bytecodes will report 368 // a length of zero, meaning we need to make another method 369 // call to calculate the length. 370 bc_length = Bytecodes::length_for(c); 371 if (bc_length == 0) { 372 bc_length = Bytecodes::length_at(method, bcp); 373 374 // length_at will put us at the bytecode after the one modified 375 // by 'wide'. We don't currently examine any of the bytecodes 376 // modified by wide, but in case we do in the future... 377 if (c == Bytecodes::_wide) { 378 prefix_length = 1; 379 c = (Bytecodes::Code)bcp[1]; 380 } 381 } 382 383 assert(bc_length != 0, "impossible bytecode length"); 384 385 switch (c) { 386 case Bytecodes::_lookupswitch : { 387 #ifndef CC_INTERP 388 Bytecode_lookupswitch bc(method, bcp); 389 (*bcp) = ( 390 bc.number_of_pairs() < BinarySwitchThreshold 391 ? Bytecodes::_fast_linearswitch 392 : Bytecodes::_fast_binaryswitch 393 ); 394 #endif 395 break; 396 } 397 case Bytecodes::_fast_linearswitch: 398 case Bytecodes::_fast_binaryswitch: { 399 #ifndef CC_INTERP 400 (*bcp) = Bytecodes::_lookupswitch; 401 #endif 402 break; 403 } 404 405 case Bytecodes::_invokespecial : { 406 rewrite_invokespecial(bcp, prefix_length+1, reverse, invokespecial_error); 407 break; 408 } 409 410 case Bytecodes::_putstatic : 411 case Bytecodes::_putfield : { 412 if (!reverse) { 413 // Check if any final field of the class given as parameter is modified 414 // outside of initializer methods of the class. Fields that are modified 415 // are marked with a flag. For marked fields, the compilers do not perform 416 // constant folding (as the field can be changed after initialization). 417 // 418 // The check is performed after verification and only if verification has 419 // succeeded. Therefore, the class is guaranteed to be well-formed. 420 InstanceKlass* klass = method->method_holder(); 421 u2 bc_index = Bytes::get_Java_u2(bcp + prefix_length + 1); 422 constantPoolHandle cp(method->constants()); 423 Symbol* ref_class_name = cp->klass_name_at(cp->klass_ref_index_at(bc_index)); 424 425 if (klass->name() == ref_class_name) { 426 Symbol* field_name = cp->name_ref_at(bc_index); 427 Symbol* field_sig = cp->signature_ref_at(bc_index); 428 429 fieldDescriptor fd; 430 if (klass->find_field(field_name, field_sig, &fd) != NULL) { 431 if (fd.access_flags().is_final()) { 432 if (fd.access_flags().is_static()) { 433 if (!method->is_static_initializer()) { 434 fd.set_has_initialized_final_update(true); 435 } 436 } else { 437 if (!method->is_object_initializer()) { 438 fd.set_has_initialized_final_update(true); 439 } 440 } 441 } 442 } 443 } 444 } 445 } 446 // fall through 447 case Bytecodes::_getstatic : // fall through 448 case Bytecodes::_getfield : // fall through 449 case Bytecodes::_invokevirtual : // fall through 450 case Bytecodes::_invokestatic : 451 case Bytecodes::_invokeinterface: 452 case Bytecodes::_invokehandle : // if reverse=true 453 rewrite_member_reference(bcp, prefix_length+1, reverse); 454 break; 455 case Bytecodes::_invokedynamic: 456 rewrite_invokedynamic(bcp, prefix_length+1, reverse); 457 break; 458 case Bytecodes::_ldc: 459 case Bytecodes::_fast_aldc: // if reverse=true 460 maybe_rewrite_ldc(bcp, prefix_length+1, false, reverse); 461 break; 462 case Bytecodes::_ldc_w: 463 case Bytecodes::_fast_aldc_w: // if reverse=true 464 maybe_rewrite_ldc(bcp, prefix_length+1, true, reverse); 465 break; 466 case Bytecodes::_jsr : // fall through 467 case Bytecodes::_jsr_w : nof_jsrs++; break; 468 case Bytecodes::_monitorenter : // fall through 469 case Bytecodes::_monitorexit : has_monitor_bytecodes = true; break; 470 } 471 } 472 } 473 474 // Update access flags 475 if (has_monitor_bytecodes) { 476 method->set_has_monitor_bytecodes(); 477 } 478 479 // The present of a jsr bytecode implies that the method might potentially 480 // have to be rewritten, so we run the oopMapGenerator on the method 481 if (nof_jsrs > 0) { 482 method->set_has_jsrs(); 483 // Second pass will revisit this method. 484 assert(method->has_jsrs(), "didn't we just set this?"); 485 } 486 } 487 488 // After constant pool is created, revisit methods containing jsrs. 489 methodHandle Rewriter::rewrite_jsrs(methodHandle method, TRAPS) { 490 ResourceMark rm(THREAD); 491 ResolveOopMapConflicts romc(method); 492 methodHandle original_method = method; 493 method = romc.do_potential_rewrite(CHECK_(methodHandle())); 494 // Update monitor matching info. 495 if (romc.monitor_safe()) { 496 method->set_guaranteed_monitor_matching(); 497 } 498 499 return method; 500 } 501 502 void Rewriter::rewrite_bytecodes(TRAPS) { 503 assert(_pool->cache() == NULL, "constant pool cache must not be set yet"); 504 505 // determine index maps for Method* rewriting 506 compute_index_maps(); 507 508 if (RegisterFinalizersAtInit && _klass->name() == vmSymbols::java_lang_Object()) { 509 bool did_rewrite = false; 510 int i = _methods->length(); 511 while (i-- > 0) { 512 Method* method = _methods->at(i); 513 if (method->intrinsic_id() == vmIntrinsics::_Object_init) { 514 // rewrite the return bytecodes of Object.<init> to register the 515 // object for finalization if needed. 516 methodHandle m(THREAD, method); 517 rewrite_Object_init(m, CHECK); 518 did_rewrite = true; 519 break; 520 } 521 } 522 assert(did_rewrite, "must find Object::<init> to rewrite it"); 523 } 524 525 // rewrite methods, in two passes 526 int len = _methods->length(); 527 bool invokespecial_error = false; 528 529 for (int i = len-1; i >= 0; i--) { 530 Method* method = _methods->at(i); 531 scan_method(method, false, &invokespecial_error); 532 if (invokespecial_error) { 533 // If you get an error here, there is no reversing bytecodes 534 // This exception is stored for this class and no further attempt is 535 // made at verifying or rewriting. 536 THROW_MSG(vmSymbols::java_lang_InternalError(), 537 "This classfile overflows invokespecial for interfaces " 538 "and cannot be loaded"); 539 return; 540 } 541 } 542 543 // May have to fix invokedynamic bytecodes if invokestatic/InterfaceMethodref 544 // entries had to be added. 545 patch_invokedynamic_bytecodes(); 546 } 547 548 void Rewriter::rewrite(InstanceKlass* klass, TRAPS) { 549 if (!DumpSharedSpaces) { 550 assert(!MetaspaceShared::is_in_shared_space(klass), "archive methods must not be rewritten at run time"); 551 } 552 ResourceMark rm(THREAD); 553 Rewriter rw(klass, klass->constants(), klass->methods(), CHECK); 554 // (That's all, folks.) 555 } 556 557 Rewriter::Rewriter(InstanceKlass* klass, const constantPoolHandle& cpool, Array<Method*>* methods, TRAPS) 558 : _klass(klass), 559 _pool(cpool), 560 _methods(methods), 561 _cp_map(cpool->length()), 562 _cp_cache_map(cpool->length() / 2), 563 _reference_map(cpool->length()), 564 _resolved_references_map(cpool->length() / 2), 565 _invokedynamic_references_map(cpool->length() / 2), 566 _method_handle_invokers(cpool->length()), 567 _invokedynamic_cp_cache_map(cpool->length() / 4) 568 { 569 570 // Rewrite bytecodes - exception here exits. 571 rewrite_bytecodes(CHECK); 572 573 // Stress restoring bytecodes 574 if (StressRewriter) { 575 restore_bytecodes(); 576 rewrite_bytecodes(CHECK); 577 } 578 579 // allocate constant pool cache, now that we've seen all the bytecodes 580 make_constant_pool_cache(THREAD); 581 582 // Restore bytecodes to their unrewritten state if there are exceptions 583 // rewriting bytecodes or allocating the cpCache 584 if (HAS_PENDING_EXCEPTION) { 585 restore_bytecodes(); 586 return; 587 } 588 589 // Relocate after everything, but still do this under the is_rewritten flag, 590 // so methods with jsrs in custom class lists in aren't attempted to be 591 // rewritten in the RO section of the shared archive. 592 // Relocated bytecodes don't have to be restored, only the cp cache entries 593 int len = _methods->length(); 594 for (int i = len-1; i >= 0; i--) { 595 methodHandle m(THREAD, _methods->at(i)); 596 597 if (m->has_jsrs()) { 598 m = rewrite_jsrs(m, THREAD); 599 // Restore bytecodes to their unrewritten state if there are exceptions 600 // relocating bytecodes. If some are relocated, that is ok because that 601 // doesn't affect constant pool to cpCache rewriting. 602 if (HAS_PENDING_EXCEPTION) { 603 restore_bytecodes(); 604 return; 605 } 606 // Method might have gotten rewritten. 607 methods->at_put(i, m()); 608 } 609 } 610 }