1 /*
2 * Copyright (c) 1998, 2023, 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 "cds/metaspaceShared.hpp"
27 #include "classfile/vmClasses.hpp"
28 #include "interpreter/bytecodes.hpp"
29 #include "interpreter/bytecodeStream.hpp"
30 #include "interpreter/interpreter.hpp"
31 #include "interpreter/rewriter.hpp"
32 #include "memory/metadataFactory.hpp"
33 #include "memory/resourceArea.hpp"
34 #include "oops/generateOopMap.hpp"
35 #include "oops/resolvedFieldEntry.hpp"
36 #include "oops/resolvedIndyEntry.hpp"
37 #include "prims/methodHandles.hpp"
38 #include "runtime/arguments.hpp"
39 #include "runtime/fieldDescriptor.inline.hpp"
40 #include "runtime/handles.inline.hpp"
41 #include "utilities/checkedCast.hpp"
42
43 // Computes a CPC map (new_index -> original_index) for constant pool entries
44 // that are referred to by the interpreter at runtime via the constant pool cache.
45 // Also computes a CP map (original_index -> new_index).
46 // Marks entries in CP which require additional processing.
47 void Rewriter::compute_index_maps() {
48 const int length = _pool->length();
49 init_maps(length);
50 bool saw_mh_symbol = false;
51 for (int i = 0; i < length; i++) {
52 int tag = _pool->tag_at(i).value();
53 switch (tag) {
54 case JVM_CONSTANT_Fieldref :
55 _cp_map.at_put(i, _field_entry_index);
56 _field_entry_index++;
57 _initialized_field_entries.push(ResolvedFieldEntry((u2)i));
58 break;
59 case JVM_CONSTANT_InterfaceMethodref: // fall through
60 case JVM_CONSTANT_Methodref :
61 add_cp_cache_entry(i);
62 break;
63 case JVM_CONSTANT_Dynamic:
64 assert(_pool->has_dynamic_constant(), "constant pool's _has_dynamic_constant flag not set");
65 add_resolved_references_entry(i);
66 break;
67 case JVM_CONSTANT_String : // fall through
68 case JVM_CONSTANT_MethodHandle : // fall through
69 case JVM_CONSTANT_MethodType : // fall through
70 add_resolved_references_entry(i);
71 break;
72 case JVM_CONSTANT_Utf8:
73 if (_pool->symbol_at(i) == vmSymbols::java_lang_invoke_MethodHandle() ||
74 _pool->symbol_at(i) == vmSymbols::java_lang_invoke_VarHandle()) {
75 saw_mh_symbol = true;
76 }
77 break;
78 }
79 }
80
81 // Record limits of resolved reference map for constant pool cache indices
82 record_map_limits();
83
84 guarantee((int) _cp_cache_map.length() - 1 <= (int) ((u2)-1),
85 "all cp cache indexes fit in a u2");
86
87 if (saw_mh_symbol) {
88 _method_handle_invokers.at_grow(length, 0);
89 }
90 }
91
92 // Unrewrite the bytecodes if an error occurs.
93 void Rewriter::restore_bytecodes(Thread* thread) {
94 int len = _methods->length();
95 bool invokespecial_error = false;
96
97 for (int i = len-1; i >= 0; i--) {
98 Method* method = _methods->at(i);
99 scan_method(thread, method, true, &invokespecial_error);
100 assert(!invokespecial_error, "reversing should not get an invokespecial error");
101 }
102 }
103
104 // Creates a constant pool cache given a CPC map
105 void Rewriter::make_constant_pool_cache(TRAPS) {
106 ClassLoaderData* loader_data = _pool->pool_holder()->class_loader_data();
107 ConstantPoolCache* cache =
108 ConstantPoolCache::allocate(loader_data, _cp_cache_map,
109 _invokedynamic_references_map, _initialized_indy_entries, _initialized_field_entries, CHECK);
110
111 // initialize object cache in constant pool
112 _pool->set_cache(cache);
113 cache->set_constant_pool(_pool());
114
115 // _resolved_references is stored in pool->cache(), so need to be done after
116 // the above lines.
117 _pool->initialize_resolved_references(loader_data, _resolved_references_map,
118 _resolved_reference_limit,
119 THREAD);
120 #if INCLUDE_CDS
121 if (!HAS_PENDING_EXCEPTION && Arguments::is_dumping_archive()) {
122 if (_pool->pool_holder()->is_shared()) {
123 assert(DynamicDumpSharedSpaces, "must be");
124 // We are linking a shared class from the base archive. This
125 // class won't be written into the dynamic archive, so there's no
126 // need to save its CpCaches.
127 } else {
128 cache->save_for_archive(THREAD);
129 }
130 }
131 #endif
132
133 // Clean up constant pool cache if initialize_resolved_references() failed.
134 if (HAS_PENDING_EXCEPTION) {
135 MetadataFactory::free_metadata(loader_data, cache);
136 _pool->set_cache(nullptr); // so the verifier isn't confused
137 }
138 }
139
140
141
142 // The new finalization semantics says that registration of
143 // finalizable objects must be performed on successful return from the
144 // Object.<init> constructor. We could implement this trivially if
145 // <init> were never rewritten but since JVMTI allows this to occur, a
146 // more complicated solution is required. A special return bytecode
147 // is used only by Object.<init> to signal the finalization
148 // registration point. Additionally local 0 must be preserved so it's
149 // available to pass to the registration function. For simplicity we
150 // require that local 0 is never overwritten so it's available as an
151 // argument for registration.
152
153 void Rewriter::rewrite_Object_init(const methodHandle& method, TRAPS) {
154 RawBytecodeStream bcs(method);
155 while (!bcs.is_last_bytecode()) {
156 Bytecodes::Code opcode = bcs.raw_next();
157 switch (opcode) {
158 case Bytecodes::_return: *bcs.bcp() = Bytecodes::_return_register_finalizer; break;
159
160 case Bytecodes::_istore:
161 case Bytecodes::_lstore:
162 case Bytecodes::_fstore:
163 case Bytecodes::_dstore:
164 case Bytecodes::_astore:
165 if (bcs.get_index() != 0) continue;
166
167 // fall through
168 case Bytecodes::_istore_0:
169 case Bytecodes::_lstore_0:
170 case Bytecodes::_fstore_0:
171 case Bytecodes::_dstore_0:
172 case Bytecodes::_astore_0:
173 THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(),
174 "can't overwrite local 0 in Object.<init>");
175 break;
176
177 default:
178 break;
179 }
180 }
181 }
182
183
184 void Rewriter::rewrite_field_reference(address bcp, int offset, bool reverse) {
185 address p = bcp + offset;
186 if (!reverse) {
187 int cp_index = Bytes::get_Java_u2(p);
188 int field_entry_index = _cp_map.at(cp_index);
189 Bytes::put_native_u2(p, checked_cast<u2>(field_entry_index));
190 } else {
191 int field_entry_index = Bytes::get_native_u2(p);
192 int pool_index = _initialized_field_entries.at(field_entry_index).constant_pool_index();
193 Bytes::put_Java_u2(p, checked_cast<u2>(pool_index));
194 }
195 }
196
197 // Rewrite a classfile-order CP index into a native-order CPC index.
198 void Rewriter::rewrite_member_reference(address bcp, int offset, bool reverse) {
199 address p = bcp + offset;
200 if (!reverse) {
201 int cp_index = Bytes::get_Java_u2(p);
202 int cache_index = cp_entry_to_cp_cache(cp_index);
203 Bytes::put_native_u2(p, (u2)cache_index);
204 if (!_method_handle_invokers.is_empty())
205 maybe_rewrite_invokehandle(p - 1, cp_index, cache_index, reverse);
206 } else {
207 int cache_index = Bytes::get_native_u2(p);
208 int pool_index = cp_cache_entry_pool_index(cache_index);
209 Bytes::put_Java_u2(p, (u2)pool_index);
210 if (!_method_handle_invokers.is_empty())
211 maybe_rewrite_invokehandle(p - 1, pool_index, cache_index, reverse);
212 }
213 }
214
215 // If the constant pool entry for invokespecial is InterfaceMethodref,
216 // we need to add a separate cpCache entry for its resolution, because it is
217 // different than the resolution for invokeinterface with InterfaceMethodref.
218 // These cannot share cpCache entries.
219 void Rewriter::rewrite_invokespecial(address bcp, int offset, bool reverse, bool* invokespecial_error) {
220 address p = bcp + offset;
221 if (!reverse) {
222 int cp_index = Bytes::get_Java_u2(p);
223 if (_pool->tag_at(cp_index).is_interface_method()) {
224 int cache_index = add_invokespecial_cp_cache_entry(cp_index);
225 if (cache_index != (int)(jushort) cache_index) {
226 *invokespecial_error = true;
227 }
228 Bytes::put_native_u2(p, (u2)cache_index);
229 } else {
230 rewrite_member_reference(bcp, offset, reverse);
231 }
232 } else {
233 rewrite_member_reference(bcp, offset, reverse);
234 }
235 }
236
237 // Adjust the invocation bytecode for a signature-polymorphic method (MethodHandle.invoke, etc.)
238 void Rewriter::maybe_rewrite_invokehandle(address opc, int cp_index, int cache_index, bool reverse) {
239 if (!reverse) {
240 if ((*opc) == (u1)Bytecodes::_invokevirtual ||
241 // allow invokespecial as an alias, although it would be very odd:
242 (*opc) == (u1)Bytecodes::_invokespecial) {
243 assert(_pool->tag_at(cp_index).is_method(), "wrong index");
244 // Determine whether this is a signature-polymorphic method.
245 if (cp_index >= _method_handle_invokers.length()) return;
246 int status = _method_handle_invokers.at(cp_index);
247 assert(status >= -1 && status <= 1, "oob tri-state");
248 if (status == 0) {
249 if (_pool->uncached_klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_MethodHandle() &&
250 MethodHandles::is_signature_polymorphic_name(vmClasses::MethodHandle_klass(),
251 _pool->uncached_name_ref_at(cp_index))) {
252 // we may need a resolved_refs entry for the appendix
253 add_invokedynamic_resolved_references_entry(cp_index, cache_index);
254 status = +1;
255 } else if (_pool->uncached_klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_VarHandle() &&
256 MethodHandles::is_signature_polymorphic_name(vmClasses::VarHandle_klass(),
257 _pool->uncached_name_ref_at(cp_index))) {
258 // we may need a resolved_refs entry for the appendix
259 add_invokedynamic_resolved_references_entry(cp_index, cache_index);
260 status = +1;
261 } else {
262 status = -1;
263 }
264 _method_handle_invokers.at(cp_index) = status;
265 }
266 // We use a special internal bytecode for such methods (if non-static).
267 // The basic reason for this is that such methods need an extra "appendix" argument
268 // to transmit the call site's intended call type.
269 if (status > 0) {
270 (*opc) = (u1)Bytecodes::_invokehandle;
271 }
272 }
273 } else {
274 // Do not need to look at cp_index.
275 if ((*opc) == (u1)Bytecodes::_invokehandle) {
276 (*opc) = (u1)Bytecodes::_invokevirtual;
277 // Ignore corner case of original _invokespecial instruction.
278 // This is safe because (a) the signature polymorphic method was final, and
279 // (b) the implementation of MethodHandle will not call invokespecial on it.
280 }
281 }
282 }
283
284
285 void Rewriter::rewrite_invokedynamic(address bcp, int offset, bool reverse) {
286 address p = bcp + offset;
287 assert(p[-1] == Bytecodes::_invokedynamic, "not invokedynamic bytecode");
288 if (!reverse) {
289 int cp_index = Bytes::get_Java_u2(p);
290 int resolved_index = add_invokedynamic_resolved_references_entry(cp_index, -1); // Indy no longer has a CPCE
291 // Replace the trailing four bytes with an index to the array of
292 // indy resolution information in the CPC. There is one entry for
293 // each bytecode, even if they make the same call. In other words,
294 // the CPC-to-CP relation is many-to-one for invokedynamic entries.
295 // This means we must use a larger index size than u2 to address
296 // all these entries. That is the main reason invokedynamic
297 // must have a five-byte instruction format. (Of course, other JVM
298 // implementations can use the bytes for other purposes.)
299 // Note: We use native_u4 format exclusively for 4-byte indexes.
300 Bytes::put_native_u4(p, ConstantPool::encode_invokedynamic_index(_invokedynamic_index));
301 _invokedynamic_index++;
302
303 // Collect invokedynamic information before creating ResolvedInvokeDynamicInfo array
304 _initialized_indy_entries.push(ResolvedIndyEntry((u2)resolved_index, (u2)cp_index));
305 } else {
306 // Should do nothing since we are not patching this bytecode
307 int cache_index = ConstantPool::decode_invokedynamic_index(
308 Bytes::get_native_u4(p));
309 int cp_index = _initialized_indy_entries.at(cache_index).constant_pool_index();
310 assert(_pool->tag_at(cp_index).is_invoke_dynamic(), "wrong index");
311 // zero out 4 bytes
312 Bytes::put_Java_u4(p, 0);
313 Bytes::put_Java_u2(p, (u2)cp_index);
314 }
315 }
316
317 // Rewrite some ldc bytecodes to _fast_aldc
318 void 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
326 if (tag.is_method_handle() ||
327 tag.is_method_type() ||
328 tag.is_string() ||
329 (tag.is_dynamic_constant() &&
330 // keep regular ldc interpreter logic for condy primitives
331 is_reference_type(Signature::basic_type(_pool->uncached_signature_ref_at(cp_index))))
332 ) {
333 int ref_index = cp_entry_to_resolved_references(cp_index);
334 if (is_wide) {
335 (*bcp) = Bytecodes::_fast_aldc_w;
336 assert(ref_index == (u2)ref_index, "index overflow");
337 Bytes::put_native_u2(p, (u2)ref_index);
338 } else {
339 (*bcp) = Bytecodes::_fast_aldc;
340 assert(ref_index == (u1)ref_index, "index overflow");
341 (*p) = (u1)ref_index;
342 }
343 }
344 } else {
345 Bytecodes::Code rewritten_bc =
346 (is_wide ? Bytecodes::_fast_aldc_w : Bytecodes::_fast_aldc);
347 if ((*bcp) == rewritten_bc) {
348 address p = bcp + offset;
349 int ref_index = is_wide ? Bytes::get_native_u2(p) : (u1)(*p);
350 int pool_index = resolved_references_entry_to_pool_index(ref_index);
351 if (is_wide) {
352 (*bcp) = Bytecodes::_ldc_w;
353 assert(pool_index == (u2)pool_index, "index overflow");
354 Bytes::put_Java_u2(p, (u2)pool_index);
355 } else {
356 (*bcp) = Bytecodes::_ldc;
357 assert(pool_index == (u1)pool_index, "index overflow");
358 (*p) = (u1)pool_index;
359 }
360 }
361 }
362 }
363
364
365 // Rewrites a method given the index_map information
366 void Rewriter::scan_method(Thread* thread, Method* method, bool reverse, bool* invokespecial_error) {
367
368 int nof_jsrs = 0;
369 bool has_monitor_bytecodes = false;
370 Bytecodes::Code c;
371
372 // Bytecodes and their length
373 const address code_base = method->code_base();
374 const int code_length = method->code_size();
375
376 int bc_length;
377 for (int bci = 0; bci < code_length; bci += bc_length) {
378 address bcp = code_base + bci;
379 int prefix_length = 0;
380 c = (Bytecodes::Code)(*bcp);
381
382 // Since we have the code, see if we can get the length
383 // directly. Some more complicated bytecodes will report
384 // a length of zero, meaning we need to make another method
385 // call to calculate the length.
386 bc_length = Bytecodes::length_for(c);
387 if (bc_length == 0) {
388 bc_length = Bytecodes::length_at(method, bcp);
389
390 // length_at will put us at the bytecode after the one modified
391 // by 'wide'. We don't currently examine any of the bytecodes
392 // modified by wide, but in case we do in the future...
393 if (c == Bytecodes::_wide) {
394 prefix_length = 1;
395 c = (Bytecodes::Code)bcp[1];
396 }
397 }
398
399 // Continuing with an invalid bytecode will fail in the loop below.
400 // So guarantee here.
401 guarantee(bc_length > 0, "Verifier should have caught this invalid bytecode");
402
403 switch (c) {
404 case Bytecodes::_lookupswitch : {
405 #ifndef ZERO
406 Bytecode_lookupswitch bc(method, bcp);
407 (*bcp) = (
408 bc.number_of_pairs() < BinarySwitchThreshold
409 ? Bytecodes::_fast_linearswitch
410 : Bytecodes::_fast_binaryswitch
411 );
412 #endif
413 break;
414 }
415 case Bytecodes::_fast_linearswitch:
416 case Bytecodes::_fast_binaryswitch: {
417 #ifndef ZERO
418 (*bcp) = Bytecodes::_lookupswitch;
419 #endif
420 break;
421 }
422
423 case Bytecodes::_invokespecial : {
424 rewrite_invokespecial(bcp, prefix_length+1, reverse, invokespecial_error);
425 break;
426 }
427
428 case Bytecodes::_putstatic :
429 case Bytecodes::_putfield : {
430 if (!reverse) {
431 // Check if any final field of the class given as parameter is modified
432 // outside of initializer methods of the class. Fields that are modified
433 // are marked with a flag. For marked fields, the compilers do not perform
434 // constant folding (as the field can be changed after initialization).
435 //
436 // The check is performed after verification and only if verification has
437 // succeeded. Therefore, the class is guaranteed to be well-formed.
438 InstanceKlass* klass = method->method_holder();
439 u2 bc_index = Bytes::get_Java_u2(bcp + prefix_length + 1);
440 constantPoolHandle cp(thread, method->constants());
441 Symbol* ref_class_name = cp->klass_name_at(cp->uncached_klass_ref_index_at(bc_index));
442
443 if (klass->name() == ref_class_name) {
444 Symbol* field_name = cp->uncached_name_ref_at(bc_index);
445 Symbol* field_sig = cp->uncached_signature_ref_at(bc_index);
446
447 fieldDescriptor fd;
448 if (klass->find_field(field_name, field_sig, &fd) != nullptr) {
449 if (fd.access_flags().is_final()) {
450 if (fd.access_flags().is_static()) {
451 if (!method->is_class_initializer()) {
452 fd.set_has_initialized_final_update(true);
453 }
454 } else {
455 if (!method->is_object_constructor()) {
456 fd.set_has_initialized_final_update(true);
457 }
458 }
459 }
460 }
461 }
462 }
463 }
464 // fall through
465 case Bytecodes::_getstatic : // fall through
466 case Bytecodes::_getfield : // fall through
467 case Bytecodes::_withfield : // fall through but may require more checks for correctness
468 rewrite_field_reference(bcp, prefix_length+1, reverse);
469 break;
470 case Bytecodes::_invokevirtual : // fall through
471 case Bytecodes::_invokestatic :
472 case Bytecodes::_invokeinterface:
473 case Bytecodes::_invokehandle : // if reverse=true
474 rewrite_member_reference(bcp, prefix_length+1, reverse);
475 break;
476 case Bytecodes::_invokedynamic:
477 rewrite_invokedynamic(bcp, prefix_length+1, reverse);
478 break;
479 case Bytecodes::_ldc:
480 case Bytecodes::_fast_aldc: // if reverse=true
481 maybe_rewrite_ldc(bcp, prefix_length+1, false, reverse);
482 break;
483 case Bytecodes::_ldc_w:
484 case Bytecodes::_fast_aldc_w: // if reverse=true
485 maybe_rewrite_ldc(bcp, prefix_length+1, true, reverse);
486 break;
487 case Bytecodes::_jsr : // fall through
488 case Bytecodes::_jsr_w : nof_jsrs++; break;
489 case Bytecodes::_monitorenter : // fall through
490 case Bytecodes::_monitorexit : has_monitor_bytecodes = true; break;
491
492 default: break;
493 }
494 }
495
496 // Update flags
497 if (has_monitor_bytecodes) {
498 method->set_has_monitor_bytecodes();
499 }
500
501 // The present of a jsr bytecode implies that the method might potentially
502 // have to be rewritten, so we run the oopMapGenerator on the method
503 if (nof_jsrs > 0) {
504 method->set_has_jsrs();
505 }
506 }
507
508 // After constant pool is created, revisit methods containing jsrs.
509 methodHandle Rewriter::rewrite_jsrs(const methodHandle& method, TRAPS) {
510 ResourceMark rm(THREAD);
511 ResolveOopMapConflicts romc(method);
512 methodHandle new_method = romc.do_potential_rewrite(CHECK_(methodHandle()));
513 // Update monitor matching info.
514 if (romc.monitor_safe()) {
515 new_method->set_guaranteed_monitor_matching();
516 }
517
518 return new_method;
519 }
520
521 void Rewriter::rewrite_bytecodes(TRAPS) {
522 assert(_pool->cache() == nullptr, "constant pool cache must not be set yet");
523
524 // determine index maps for Method* rewriting
525 compute_index_maps();
526
527 if (RegisterFinalizersAtInit && _klass->name() == vmSymbols::java_lang_Object()) {
528 bool did_rewrite = false;
529 int i = _methods->length();
530 while (i-- > 0) {
531 Method* method = _methods->at(i);
532 if (method->intrinsic_id() == vmIntrinsics::_Object_init) {
533 // rewrite the return bytecodes of Object.<init> to register the
534 // object for finalization if needed.
535 methodHandle m(THREAD, method);
536 rewrite_Object_init(m, CHECK);
537 did_rewrite = true;
538 break;
539 }
540 }
541 assert(did_rewrite, "must find Object::<init> to rewrite it");
542 }
543
544 // rewrite methods, in two passes
545 int len = _methods->length();
546 bool invokespecial_error = false;
547
548 for (int i = len-1; i >= 0; i--) {
549 Method* method = _methods->at(i);
550 scan_method(THREAD, method, false, &invokespecial_error);
551 if (invokespecial_error) {
552 // If you get an error here, there is no reversing bytecodes
553 // This exception is stored for this class and no further attempt is
554 // made at verifying or rewriting.
555 THROW_MSG(vmSymbols::java_lang_InternalError(),
556 "This classfile overflows invokespecial for interfaces "
557 "and cannot be loaded");
558 return;
559 }
560 }
561 }
562
563 void Rewriter::rewrite(InstanceKlass* klass, TRAPS) {
564 #if INCLUDE_CDS
565 if (klass->is_shared()) {
566 assert(!klass->is_rewritten(), "rewritten shared classes cannot be rewritten again");
567 }
568 #endif // INCLUDE_CDS
569 ResourceMark rm(THREAD);
570 constantPoolHandle cpool(THREAD, klass->constants());
571 Rewriter rw(klass, cpool, klass->methods(), CHECK);
572 // (That's all, folks.)
573 }
574
575 Rewriter::Rewriter(InstanceKlass* klass, const constantPoolHandle& cpool, Array<Method*>* methods, TRAPS)
576 : _klass(klass),
577 _pool(cpool),
578 _methods(methods),
579 _cp_map(cpool->length()),
580 _cp_cache_map(cpool->length() / 2),
581 _reference_map(cpool->length()),
582 _resolved_references_map(cpool->length() / 2),
583 _invokedynamic_references_map(cpool->length() / 2),
584 _method_handle_invokers(cpool->length()),
585 _invokedynamic_index(0),
586 _field_entry_index(0)
587 {
588
589 // Rewrite bytecodes - exception here exits.
590 rewrite_bytecodes(CHECK);
591
592 // Stress restoring bytecodes
593 if (StressRewriter) {
594 restore_bytecodes(THREAD);
595 rewrite_bytecodes(CHECK);
596 }
597
598 // allocate constant pool cache, now that we've seen all the bytecodes
599 make_constant_pool_cache(THREAD);
600
601 // Restore bytecodes to their unrewritten state if there are exceptions
602 // rewriting bytecodes or allocating the cpCache
603 if (HAS_PENDING_EXCEPTION) {
604 restore_bytecodes(THREAD);
605 return;
606 }
607
608 // Relocate after everything, but still do this under the is_rewritten flag,
609 // so methods with jsrs in custom class lists in aren't attempted to be
610 // rewritten in the RO section of the shared archive.
611 // Relocated bytecodes don't have to be restored, only the cp cache entries
612 int len = _methods->length();
613 for (int i = len-1; i >= 0; i--) {
614 methodHandle m(THREAD, _methods->at(i));
615
616 if (m->has_jsrs()) {
617 m = rewrite_jsrs(m, THREAD);
618 // Restore bytecodes to their unrewritten state if there are exceptions
619 // relocating bytecodes. If some are relocated, that is ok because that
620 // doesn't affect constant pool to cpCache rewriting.
621 if (HAS_PENDING_EXCEPTION) {
622 restore_bytecodes(THREAD);
623 return;
624 }
625 // Method might have gotten rewritten.
626 methods->at_put(i, m());
627 }
628 }
629 }
--- EOF ---