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/metadataFactory.hpp" 31#include "memory/metaspaceShared.hpp" 32#include "memory/resourceArea.hpp" 33#include "oops/generateOopMap.hpp" 34#include "prims/methodHandles.hpp" 35 36// Computes a CPC map (new_index -> original_index) for constant pool entries 37// that are referred to by the interpreter at runtime via the constant pool cache. 38// Also computes a CP map (original_index -> new_index). 39// Marks entries in CP which require additional processing. 40void Rewriter::compute_index_maps() { 41 const int length = _pool->length(); 42 init_maps(length); 43 bool saw_mh_symbol = false; 44 for (int i = 0; i < length; i++) { 45 int tag = _pool->tag_at(i).value(); 46 switch (tag) { 47 case JVM_CONSTANT_InterfaceMethodref: 48 case JVM_CONSTANT_Fieldref : // fall through 49 case JVM_CONSTANT_Methodref : // fall through 50 add_cp_cache_entry(i); 51 break; 52 case JVM_CONSTANT_String: 53 case JVM_CONSTANT_MethodHandle : // fall through 54 case JVM_CONSTANT_MethodType : // fall through 55 add_resolved_references_entry(i); 56 break; 57 case JVM_CONSTANT_Utf8: 58 if (_pool->symbol_at(i) == vmSymbols::java_lang_invoke_MethodHandle() || 59 _pool->symbol_at(i) == vmSymbols::java_lang_invoke_VarHandle()) { 60 saw_mh_symbol = true; 61 } 62 break; 63 } 64 } 65 66 // Record limits of resolved reference map for constant pool cache indices 67 record_map_limits(); 68 69 guarantee((int) _cp_cache_map.length() - 1 <= (int) ((u2)-1), 70 "all cp cache indexes fit in a u2"); 71 72 if (saw_mh_symbol) { 73 _method_handle_invokers.at_grow(length, 0); 74 } 75} 76 77// Unrewrite the bytecodes if an error occurs. 78void Rewriter::restore_bytecodes() { 79 int len = _methods->length(); 80 bool invokespecial_error = false; 81 82 for (int i = len-1; i >= 0; i--) { 83 Method* method = _methods->at(i); 84 scan_method(method, true, &invokespecial_error); 85 assert(!invokespecial_error, "reversing should not get an invokespecial error"); 86 } 87} 88 89// Creates a constant pool cache given a CPC map 90void Rewriter::make_constant_pool_cache(TRAPS) { 91 ClassLoaderData* loader_data = _pool->pool_holder()->class_loader_data(); 92 ConstantPoolCache* cache = 93 ConstantPoolCache::allocate(loader_data, _cp_cache_map, 94 _invokedynamic_cp_cache_map, 95 _invokedynamic_references_map, CHECK); 96 97 // initialize object cache in constant pool 98 _pool->set_cache(cache); 99 cache->set_constant_pool(_pool()); 100 101 // _resolved_references is stored in pool->cache(), so need to be done after 102 // the above lines. 103 _pool->initialize_resolved_references(loader_data, _resolved_references_map, 104 _resolved_reference_limit, 105 THREAD); 106 107 // Clean up constant pool cache if initialize_resolved_references() failed. 108 if (HAS_PENDING_EXCEPTION) { 109 MetadataFactory::free_metadata(loader_data, cache); 110 _pool->set_cache(NULL); // so the verifier isn't confused 111 } 112 113 DEBUG_ONLY( 114 if (DumpSharedSpaces) { 115 cache->verify_just_initialized(); 116 }) 117} 118 119 120 121// The new finalization semantics says that registration of 122// finalizable objects must be performed on successful return from the 123// Object.<init> constructor. We could implement this trivially if 124// <init> were never rewritten but since JVMTI allows this to occur, a 125// more complicated solution is required. A special return bytecode 126// is used only by Object.<init> to signal the finalization 127// registration point. Additionally local 0 must be preserved so it's 128// available to pass to the registration function. For simplicity we 129// require that local 0 is never overwritten so it's available as an 130// argument for registration. 131 132void Rewriter::rewrite_Object_init(const methodHandle& method, TRAPS) { 133 RawBytecodeStream bcs(method); 134 while (!bcs.is_last_bytecode()) { 135 Bytecodes::Code opcode = bcs.raw_next(); 136 switch (opcode) { 137 case Bytecodes::_return: *bcs.bcp() = Bytecodes::_return_register_finalizer; break; 138 139 case Bytecodes::_istore: 140 case Bytecodes::_lstore: 141 case Bytecodes::_fstore: 142 case Bytecodes::_dstore: 143 case Bytecodes::_astore: 144 if (bcs.get_index() != 0) continue; 145 146 // fall through 147 case Bytecodes::_istore_0: 148 case Bytecodes::_lstore_0: 149 case Bytecodes::_fstore_0: 150 case Bytecodes::_dstore_0: 151 case Bytecodes::_astore_0: 152 THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(), 153 "can't overwrite local 0 in Object.<init>"); 154 break; 155 156 default: 157 break; 158 } 159 } 160} 161 162 163// Rewrite a classfile-order CP index into a native-order CPC index. 164void Rewriter::rewrite_member_reference(address bcp, int offset, bool reverse) { 165 address p = bcp + offset; 166 if (!reverse) { 167 int cp_index = Bytes::get_Java_u2(p); 168 int cache_index = cp_entry_to_cp_cache(cp_index); 169 Bytes::put_native_u2(p, cache_index); 170 if (!_method_handle_invokers.is_empty()) 171 maybe_rewrite_invokehandle(p - 1, cp_index, cache_index, reverse); 172 } else { 173 int cache_index = Bytes::get_native_u2(p); 174 int pool_index = cp_cache_entry_pool_index(cache_index); 175 Bytes::put_Java_u2(p, pool_index); 176 if (!_method_handle_invokers.is_empty()) 177 maybe_rewrite_invokehandle(p - 1, pool_index, cache_index, reverse); 178 } 179} 180 181// If the constant pool entry for invokespecial is InterfaceMethodref, 182// we need to add a separate cpCache entry for its resolution, because it is 183// different than the resolution for invokeinterface with InterfaceMethodref. 184// These cannot share cpCache entries. 185void Rewriter::rewrite_invokespecial(address bcp, int offset, bool reverse, bool* invokespecial_error) { 186 address p = bcp + offset; 187 if (!reverse) { 188 int cp_index = Bytes::get_Java_u2(p); 189 if (_pool->tag_at(cp_index).is_interface_method()) { 190 int cache_index = add_invokespecial_cp_cache_entry(cp_index); 191 if (cache_index != (int)(jushort) cache_index) { 192 *invokespecial_error = true; 193 } 194 Bytes::put_native_u2(p, cache_index); 195 } else { 196 rewrite_member_reference(bcp, offset, reverse); 197 } 198 } else { 199 rewrite_member_reference(bcp, offset, reverse); 200 } 201} 202 203 204// Adjust the invocation bytecode for a signature-polymorphic method (MethodHandle.invoke, etc.) 205void Rewriter::maybe_rewrite_invokehandle(address opc, int cp_index, int cache_index, bool reverse) { 206 if (!reverse) { 207 if ((*opc) == (u1)Bytecodes::_invokevirtual || 208 // allow invokespecial as an alias, although it would be very odd: 209 (*opc) == (u1)Bytecodes::_invokespecial) { 210 assert(_pool->tag_at(cp_index).is_method(), "wrong index"); 211 // Determine whether this is a signature-polymorphic method. 212 if (cp_index >= _method_handle_invokers.length()) return; 213 int status = _method_handle_invokers.at(cp_index); 214 assert(status >= -1 && status <= 1, "oob tri-state"); 215 if (status == 0) { 216 if (_pool->klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_MethodHandle() && 217 MethodHandles::is_signature_polymorphic_name(SystemDictionary::MethodHandle_klass(), 218 _pool->name_ref_at(cp_index))) { 219 // we may need a resolved_refs entry for the appendix 220 add_invokedynamic_resolved_references_entries(cp_index, cache_index); 221 status = +1; 222 } else if (_pool->klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_VarHandle() && 223 MethodHandles::is_signature_polymorphic_name(SystemDictionary::VarHandle_klass(), 224 _pool->name_ref_at(cp_index))) { 225 // we may need a resolved_refs entry for the appendix 226 add_invokedynamic_resolved_references_entries(cp_index, cache_index); 227 status = +1; 228 } else { 229 status = -1; 230 } 231 _method_handle_invokers.at(cp_index) = status; 232 } 233 // We use a special internal bytecode for such methods (if non-static). 234 // The basic reason for this is that such methods need an extra "appendix" argument 235 // to transmit the call site's intended call type. 236 if (status > 0) { 237 (*opc) = (u1)Bytecodes::_invokehandle; 238 } 239 } 240 } else { 241 // Do not need to look at cp_index. 242 if ((*opc) == (u1)Bytecodes::_invokehandle) { 243 (*opc) = (u1)Bytecodes::_invokevirtual; 244 // Ignore corner case of original _invokespecial instruction. 245 // This is safe because (a) the signature polymorphic method was final, and 246 // (b) the implementation of MethodHandle will not call invokespecial on it. 247 } 248 } 249} 250 251 252void Rewriter::rewrite_invokedynamic(address bcp, int offset, bool reverse) { 253 address p = bcp + offset; 254 assert(p[-1] == Bytecodes::_invokedynamic, "not invokedynamic bytecode"); 255 if (!reverse) { 256 int cp_index = Bytes::get_Java_u2(p); 257 int cache_index = add_invokedynamic_cp_cache_entry(cp_index); 258 int resolved_index = add_invokedynamic_resolved_references_entries(cp_index, cache_index); 259 // Replace the trailing four bytes with a CPC index for the dynamic 260 // call site. Unlike other CPC entries, there is one per bytecode, 261 // not just one per distinct CP entry. In other words, the 262 // CPC-to-CP relation is many-to-one for invokedynamic entries. 263 // This means we must use a larger index size than u2 to address 264 // all these entries. That is the main reason invokedynamic 265 // must have a five-byte instruction format. (Of course, other JVM 266 // implementations can use the bytes for other purposes.) 267 // Note: We use native_u4 format exclusively for 4-byte indexes. 268 Bytes::put_native_u4(p, ConstantPool::encode_invokedynamic_index(cache_index)); 269 // add the bcp in case we need to patch this bytecode if we also find a 270 // invokespecial/InterfaceMethodref in the bytecode stream 271 _patch_invokedynamic_bcps->push(p); 272 _patch_invokedynamic_refs->push(resolved_index); 273 } else { 274 int cache_index = ConstantPool::decode_invokedynamic_index( 275 Bytes::get_native_u4(p)); 276 // We will reverse the bytecode rewriting _after_ adjusting them. 277 // Adjust the cache index by offset to the invokedynamic entries in the 278 // cpCache plus the delta if the invokedynamic bytecodes were adjusted. 279 int adjustment = cp_cache_delta() + _first_iteration_cp_cache_limit; 280 int cp_index = invokedynamic_cp_cache_entry_pool_index(cache_index - adjustment); 281 assert(_pool->tag_at(cp_index).is_invoke_dynamic(), "wrong index"); 282 // zero out 4 bytes 283 Bytes::put_Java_u4(p, 0); 284 Bytes::put_Java_u2(p, cp_index); 285 } 286} 287 288void Rewriter::patch_invokedynamic_bytecodes() { 289 // If the end of the cp_cache is the same as after initializing with the 290 // cpool, nothing needs to be done. Invokedynamic bytecodes are at the 291 // correct offsets. ie. no invokespecials added 292 int delta = cp_cache_delta(); 293 if (delta > 0) { 294 int length = _patch_invokedynamic_bcps->length(); 295 assert(length == _patch_invokedynamic_refs->length(), 296 "lengths should match"); 297 for (int i = 0; i < length; i++) { 298 address p = _patch_invokedynamic_bcps->at(i); 299 int cache_index = ConstantPool::decode_invokedynamic_index( 300 Bytes::get_native_u4(p)); 301 Bytes::put_native_u4(p, ConstantPool::encode_invokedynamic_index(cache_index + delta)); 302 303 // invokedynamic resolved references map also points to cp cache and must 304 // add delta to each. 305 int resolved_index = _patch_invokedynamic_refs->at(i); 306 for (int entry = 0; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) { 307 assert(_invokedynamic_references_map.at(resolved_index + entry) == cache_index, 308 "should be the same index"); 309 _invokedynamic_references_map.at_put(resolved_index+entry, 310 cache_index + delta); 311 } 312 } 313 } 314} 315 316 317// Rewrite some ldc bytecodes to _fast_aldc 318void Rewriter::maybe_rewrite_ldc(address bcp, int offset, bool is_wide, 319 bool reverse) { 320 if (!reverse) { 321 assert((*bcp) == (is_wide ? Bytecodes::_ldc_w : Bytecodes::_ldc), "not ldc bytecode"); 322 address p = bcp + offset; 323 int cp_index = is_wide ? Bytes::get_Java_u2(p) : (u1)(*p); 324 constantTag tag = _pool->tag_at(cp_index).value(); 325 if (tag.is_method_handle() || tag.is_method_type() || tag.is_string()) { 326 int ref_index = cp_entry_to_resolved_references(cp_index); 327 if (is_wide) { 328 (*bcp) = Bytecodes::_fast_aldc_w; 329 assert(ref_index == (u2)ref_index, "index overflow"); 330 Bytes::put_native_u2(p, ref_index); 331 } else { 332 (*bcp) = Bytecodes::_fast_aldc; 333 assert(ref_index == (u1)ref_index, "index overflow"); 334 (*p) = (u1)ref_index; 335 } 336 } 337 } else { 338 Bytecodes::Code rewritten_bc = 339 (is_wide ? Bytecodes::_fast_aldc_w : Bytecodes::_fast_aldc); 340 if ((*bcp) == rewritten_bc) { 341 address p = bcp + offset; 342 int ref_index = is_wide ? Bytes::get_native_u2(p) : (u1)(*p); 343 int pool_index = resolved_references_entry_to_pool_index(ref_index); 344 if (is_wide) { 345 (*bcp) = Bytecodes::_ldc_w; 346 assert(pool_index == (u2)pool_index, "index overflow"); 347 Bytes::put_Java_u2(p, pool_index); 348 } else { 349 (*bcp) = Bytecodes::_ldc; 350 assert(pool_index == (u1)pool_index, "index overflow"); 351 (*p) = (u1)pool_index; 352 } 353 } 354 } 355} 356 357 358// Rewrites a method given the index_map information 359void Rewriter::scan_method(Method* method, bool reverse, bool* invokespecial_error) { 360 361 int nof_jsrs = 0; 362 bool has_monitor_bytecodes = false; 363 Bytecodes::Code c; 364 365 // Bytecodes and their length 366 const address code_base = method->code_base(); 367 const int code_length = method->code_size(); 368 369 int bc_length; 370 for (int bci = 0; bci < code_length; bci += bc_length) { 371 address bcp = code_base + bci; 372 int prefix_length = 0; 373 c = (Bytecodes::Code)(*bcp); 374 375 // Since we have the code, see if we can get the length 376 // directly. Some more complicated bytecodes will report 377 // a length of zero, meaning we need to make another method 378 // call to calculate the length. 379 bc_length = Bytecodes::length_for(c); 380 if (bc_length == 0) { 381 bc_length = Bytecodes::length_at(method, bcp); 382 383 // length_at will put us at the bytecode after the one modified 384 // by 'wide'. We don't currently examine any of the bytecodes 385 // modified by wide, but in case we do in the future... 386 if (c == Bytecodes::_wide) { 387 prefix_length = 1; 388 c = (Bytecodes::Code)bcp[1]; 389 } 390 } 391 392 assert(bc_length != 0, "impossible bytecode length"); 393 394 switch (c) { 395 case Bytecodes::_lookupswitch : { 396#ifndef CC_INTERP 397 Bytecode_lookupswitch bc(method, bcp); 398 (*bcp) = ( 399 bc.number_of_pairs() < BinarySwitchThreshold 400 ? Bytecodes::_fast_linearswitch 401 : Bytecodes::_fast_binaryswitch 402 ); 403#endif 404 break; 405 } 406 case Bytecodes::_fast_linearswitch: 407 case Bytecodes::_fast_binaryswitch: { 408#ifndef CC_INTERP 409 (*bcp) = Bytecodes::_lookupswitch; 410#endif 411 break; 412 } 413 414 case Bytecodes::_invokespecial : { 415 rewrite_invokespecial(bcp, prefix_length+1, reverse, invokespecial_error); 416 break; 417 } 418 419 case Bytecodes::_putstatic : 420 case Bytecodes::_putfield : { 421 if (!reverse) { 422 // Check if any final field of the class given as parameter is modified 423 // outside of initializer methods of the class. Fields that are modified 424 // are marked with a flag. For marked fields, the compilers do not perform 425 // constant folding (as the field can be changed after initialization). 426 // 427 // The check is performed after verification and only if verification has 428 // succeeded. Therefore, the class is guaranteed to be well-formed. 429 InstanceKlass* klass = method->method_holder(); 430 u2 bc_index = Bytes::get_Java_u2(bcp + prefix_length + 1); 431 constantPoolHandle cp(method->constants()); 432 Symbol* ref_class_name = cp->klass_name_at(cp->klass_ref_index_at(bc_index)); 433 434 if (klass->name() == ref_class_name) { 435 Symbol* field_name = cp->name_ref_at(bc_index); 436 Symbol* field_sig = cp->signature_ref_at(bc_index); 437 438 fieldDescriptor fd; 439 if (klass->find_field(field_name, field_sig, &fd) != NULL) { 440 if (fd.access_flags().is_final()) { 441 if (fd.access_flags().is_static()) { 442 if (!method->is_static_initializer()) { 443 fd.set_has_initialized_final_update(true); 444 } 445 } else { 446 if (!method->is_object_initializer()) { 447 fd.set_has_initialized_final_update(true); 448 } 449 } 450 } 451 } 452 } 453 } 454 } 455 // fall through 456 case Bytecodes::_getstatic : // fall through 457 case Bytecodes::_getfield : // fall through 458 case Bytecodes::_invokevirtual : // fall through 459 case Bytecodes::_invokestatic : 460 case Bytecodes::_invokeinterface: 461 case Bytecodes::_invokehandle : // if reverse=true 462 rewrite_member_reference(bcp, prefix_length+1, reverse); 463 break; 464 case Bytecodes::_invokedynamic: 465 rewrite_invokedynamic(bcp, prefix_length+1, reverse); 466 break; 467 case Bytecodes::_ldc: 468 case Bytecodes::_fast_aldc: // if reverse=true 469 maybe_rewrite_ldc(bcp, prefix_length+1, false, reverse); 470 break; 471 case Bytecodes::_ldc_w: 472 case Bytecodes::_fast_aldc_w: // if reverse=true 473 maybe_rewrite_ldc(bcp, prefix_length+1, true, reverse); 474 break; 475 case Bytecodes::_jsr : // fall through 476 case Bytecodes::_jsr_w : nof_jsrs++; break; 477 case Bytecodes::_monitorenter : // fall through 478 case Bytecodes::_monitorexit : has_monitor_bytecodes = true; break; 479 480 default: break; 481 } 482 } 483 484 // Update access flags 485 if (has_monitor_bytecodes) { 486 method->set_has_monitor_bytecodes(); 487 } 488 489 // The present of a jsr bytecode implies that the method might potentially 490 // have to be rewritten, so we run the oopMapGenerator on the method 491 if (nof_jsrs > 0) { 492 method->set_has_jsrs(); 493 // Second pass will revisit this method. 494 assert(method->has_jsrs(), "didn't we just set this?"); 495 } 496} 497 498// After constant pool is created, revisit methods containing jsrs. 499methodHandle Rewriter::rewrite_jsrs(const methodHandle& method, TRAPS) { 500 ResourceMark rm(THREAD); 501 ResolveOopMapConflicts romc(method); 502 methodHandle new_method = romc.do_potential_rewrite(CHECK_(methodHandle())); 503 // Update monitor matching info. 504 if (romc.monitor_safe()) { 505 new_method->set_guaranteed_monitor_matching(); 506 } 507 508 return new_method; 509} 510 511void Rewriter::rewrite_bytecodes(TRAPS) { 512 assert(_pool->cache() == NULL, "constant pool cache must not be set yet"); 513 514 // determine index maps for Method* rewriting 515 compute_index_maps(); 516 517 if (RegisterFinalizersAtInit && _klass->name() == vmSymbols::java_lang_Object()) { 518 bool did_rewrite = false; 519 int i = _methods->length(); 520 while (i-- > 0) { 521 Method* method = _methods->at(i); 522 if (method->intrinsic_id() == vmIntrinsics::_Object_init) { 523 // rewrite the return bytecodes of Object.<init> to register the 524 // object for finalization if needed. 525 methodHandle m(THREAD, method); 526 rewrite_Object_init(m, CHECK); 527 did_rewrite = true; 528 break; 529 } 530 } 531 assert(did_rewrite, "must find Object::<init> to rewrite it"); 532 } 533 534 // rewrite methods, in two passes 535 int len = _methods->length(); 536 bool invokespecial_error = false; 537 538 for (int i = len-1; i >= 0; i--) { 539 Method* method = _methods->at(i); 540 scan_method(method, false, &invokespecial_error); 541 if (invokespecial_error) { 542 // If you get an error here, there is no reversing bytecodes 543 // This exception is stored for this class and no further attempt is 544 // made at verifying or rewriting. 545 THROW_MSG(vmSymbols::java_lang_InternalError(), 546 "This classfile overflows invokespecial for interfaces " 547 "and cannot be loaded"); 548 return; 549 } 550 } 551 552 // May have to fix invokedynamic bytecodes if invokestatic/InterfaceMethodref 553 // entries had to be added. 554 patch_invokedynamic_bytecodes(); 555} 556 557void Rewriter::rewrite(InstanceKlass* klass, TRAPS) { 558 if (!DumpSharedSpaces) { 559 assert(!MetaspaceShared::is_in_shared_space(klass), "archive methods must not be rewritten at run time"); 560 } 561 ResourceMark rm(THREAD); 562 Rewriter rw(klass, klass->constants(), klass->methods(), CHECK); 563 // (That's all, folks.) 564} 565 566Rewriter::Rewriter(InstanceKlass* klass, const constantPoolHandle& cpool, Array<Method*>* methods, TRAPS) 567 : _klass(klass), 568 _pool(cpool), 569 _methods(methods), 570 _cp_map(cpool->length()), 571 _cp_cache_map(cpool->length() / 2), 572 _reference_map(cpool->length()), 573 _resolved_references_map(cpool->length() / 2), 574 _invokedynamic_references_map(cpool->length() / 2), 575 _method_handle_invokers(cpool->length()), 576 _invokedynamic_cp_cache_map(cpool->length() / 4) 577{ 578 579 // Rewrite bytecodes - exception here exits. 580 rewrite_bytecodes(CHECK); 581 582 // Stress restoring bytecodes 583 if (StressRewriter) { 584 restore_bytecodes(); 585 rewrite_bytecodes(CHECK); 586 } 587 588 // allocate constant pool cache, now that we've seen all the bytecodes 589 make_constant_pool_cache(THREAD); 590 591 // Restore bytecodes to their unrewritten state if there are exceptions 592 // rewriting bytecodes or allocating the cpCache 593 if (HAS_PENDING_EXCEPTION) { 594 restore_bytecodes(); 595 return; 596 } 597 598 // Relocate after everything, but still do this under the is_rewritten flag, 599 // so methods with jsrs in custom class lists in aren't attempted to be 600 // rewritten in the RO section of the shared archive. 601 // Relocated bytecodes don't have to be restored, only the cp cache entries 602 int len = _methods->length(); 603 for (int i = len-1; i >= 0; i--) { 604 methodHandle m(THREAD, _methods->at(i)); 605 606 if (m->has_jsrs()) { 607 m = rewrite_jsrs(m, THREAD); 608 // Restore bytecodes to their unrewritten state if there are exceptions 609 // relocating bytecodes. If some are relocated, that is ok because that 610 // doesn't affect constant pool to cpCache rewriting. 611 if (HAS_PENDING_EXCEPTION) { 612 restore_bytecodes(); 613 return; 614 } 615 // Method might have gotten rewritten. 616 methods->at_put(i, m()); 617 } 618 } 619} 620