1 /*
2 * Copyright (c) 1998, 2019, 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 "interpreter/bytecodes.hpp"
27 #include "interpreter/interpreter.hpp"
28 #include "interpreter/rewriter.hpp"
29 #include "memory/metadataFactory.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "oops/constantPool.hpp"
32 #include "oops/generateOopMap.hpp"
33 #include "prims/methodHandles.hpp"
34 #include "runtime/fieldDescriptor.inline.hpp"
35 #include "runtime/handles.inline.hpp"
36
37 // Computes a CPC map (new_index -> original_index) for constant pool entries
38 // that are referred to by the interpreter at runtime via the constant pool cache.
39 // Also computes a CP map (original_index -> new_index).
40 // Marks entries in CP which require additional processing.
41 void Rewriter::compute_index_maps() {
42 const int length = _pool->length();
43 init_maps(length);
44 bool saw_mh_symbol = false;
45 for (int i = 0; i < length; i++) {
46 int tag = _pool->tag_at(i).value();
47 switch (tag) {
48 case JVM_CONSTANT_InterfaceMethodref:
49 case JVM_CONSTANT_Fieldref : // fall through
50 case JVM_CONSTANT_Methodref : // fall through
51 add_cp_cache_entry(i);
52 break;
53 case JVM_CONSTANT_Dynamic:
54 assert(_pool->has_dynamic_constant(), "constant pool's _has_dynamic_constant flag not set");
55 add_resolved_references_entry(i);
56 break;
57 case JVM_CONSTANT_String : // fall through
58 case JVM_CONSTANT_MethodHandle : // fall through
59 case JVM_CONSTANT_MethodType : // fall through
60 add_resolved_references_entry(i);
61 break;
62 case JVM_CONSTANT_Utf8:
63 if (_pool->symbol_at(i) == vmSymbols::java_lang_invoke_MethodHandle() ||
64 _pool->symbol_at(i) == vmSymbols::java_lang_invoke_VarHandle()) {
65 saw_mh_symbol = true;
66 }
67 break;
68 }
69 }
70
71 // Record limits of resolved reference map for constant pool cache indices
72 record_map_limits();
73
74 guarantee((int) _cp_cache_map.length() - 1 <= (int) ((u2)-1),
75 "all cp cache indexes fit in a u2");
76
77 if (saw_mh_symbol) {
78 _method_handle_invokers.at_grow(length, 0);
79 }
80 }
81
82 // Unrewrite the bytecodes if an error occurs.
83 void Rewriter::restore_bytecodes() {
84 int len = _methods->length();
85 bool invokespecial_error = false;
86
87 for (int i = len-1; i >= 0; i--) {
88 Method* method = _methods->at(i);
89 scan_method(method, true, &invokespecial_error);
90 assert(!invokespecial_error, "reversing should not get an invokespecial error");
91 }
92 }
93
94 // Creates a constant pool cache given a CPC map
95 void Rewriter::make_constant_pool_cache(TRAPS) {
96 ClassLoaderData* loader_data = _pool->pool_holder()->class_loader_data();
97 ConstantPoolCache* cache =
98 ConstantPoolCache::allocate(loader_data, _cp_cache_map,
99 _invokedynamic_cp_cache_map,
100 _invokedynamic_references_map, CHECK);
101
102 // initialize object cache in constant pool
103 _pool->set_cache(cache);
104 cache->set_constant_pool(_pool());
105
106 // _resolved_references is stored in pool->cache(), so need to be done after
107 // the above lines.
108 _pool->initialize_resolved_references(loader_data, _resolved_references_map,
109 _resolved_reference_limit,
110 THREAD);
111
112 // Clean up constant pool cache if initialize_resolved_references() failed.
113 if (HAS_PENDING_EXCEPTION) {
114 MetadataFactory::free_metadata(loader_data, cache);
115 _pool->set_cache(NULL); // so the verifier isn't confused
116 } else {
117 DEBUG_ONLY(
118 if (DumpSharedSpaces) {
119 cache->verify_just_initialized();
120 })
121 }
122 }
123
124
125
126 // The new finalization semantics says that registration of
127 // finalizable objects must be performed on successful return from the
128 // Object.<init> constructor. We could implement this trivially if
129 // <init> were never rewritten but since JVMTI allows this to occur, a
130 // more complicated solution is required. A special return bytecode
131 // is used only by Object.<init> to signal the finalization
132 // registration point. Additionally local 0 must be preserved so it's
133 // available to pass to the registration function. For simplicity we
134 // require that local 0 is never overwritten so it's available as an
135 // argument for registration.
136
137 void Rewriter::rewrite_Object_init(const methodHandle& method, TRAPS) {
138 RawBytecodeStream bcs(method);
139 while (!bcs.is_last_bytecode()) {
140 Bytecodes::Code opcode = bcs.raw_next();
141 switch (opcode) {
142 case Bytecodes::_return: *bcs.bcp() = Bytecodes::_return_register_finalizer; break;
143
144 case Bytecodes::_istore:
145 case Bytecodes::_lstore:
146 case Bytecodes::_fstore:
147 case Bytecodes::_dstore:
148 case Bytecodes::_astore:
149 if (bcs.get_index() != 0) continue;
150
151 // fall through
152 case Bytecodes::_istore_0:
153 case Bytecodes::_lstore_0:
154 case Bytecodes::_fstore_0:
155 case Bytecodes::_dstore_0:
156 case Bytecodes::_astore_0:
157 THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(),
158 "can't overwrite local 0 in Object.<init>");
159 break;
160
161 default:
162 break;
163 }
164 }
165 }
166
167
168 // Rewrite a classfile-order CP index into a native-order CPC index.
169 void Rewriter::rewrite_member_reference(address bcp, int offset, bool reverse) {
170 address p = bcp + offset;
171 if (!reverse) {
172 int cp_index = Bytes::get_Java_u2(p);
173 int cache_index = cp_entry_to_cp_cache(cp_index);
174 Bytes::put_native_u2(p, cache_index);
175 if (!_method_handle_invokers.is_empty())
176 maybe_rewrite_invokehandle(p - 1, cp_index, cache_index, reverse);
177 } else {
178 int cache_index = Bytes::get_native_u2(p);
179 int pool_index = cp_cache_entry_pool_index(cache_index);
180 Bytes::put_Java_u2(p, pool_index);
181 if (!_method_handle_invokers.is_empty())
182 maybe_rewrite_invokehandle(p - 1, pool_index, cache_index, reverse);
183 }
184 }
185
186 // If the constant pool entry for invokespecial is InterfaceMethodref,
187 // we need to add a separate cpCache entry for its resolution, because it is
188 // different than the resolution for invokeinterface with InterfaceMethodref.
189 // These cannot share cpCache entries.
190 void Rewriter::rewrite_invokespecial(address bcp, int offset, bool reverse, bool* invokespecial_error) {
191 address p = bcp + offset;
192 if (!reverse) {
193 int cp_index = Bytes::get_Java_u2(p);
194 if (_pool->tag_at(cp_index).is_interface_method()) {
195 int cache_index = add_invokespecial_cp_cache_entry(cp_index);
196 if (cache_index != (int)(jushort) cache_index) {
197 *invokespecial_error = true;
198 }
199 Bytes::put_native_u2(p, cache_index);
200 } else {
201 rewrite_member_reference(bcp, offset, reverse);
202 }
203 } else {
204 rewrite_member_reference(bcp, offset, reverse);
205 }
206 }
207
208
209 // Adjust the invocation bytecode for a signature-polymorphic method (MethodHandle.invoke, etc.)
210 void Rewriter::maybe_rewrite_invokehandle(address opc, int cp_index, int cache_index, bool reverse) {
211 if (!reverse) {
212 if ((*opc) == (u1)Bytecodes::_invokevirtual ||
213 // allow invokespecial as an alias, although it would be very odd:
214 (*opc) == (u1)Bytecodes::_invokespecial) {
215 assert(_pool->tag_at(cp_index).is_method(), "wrong index");
216 // Determine whether this is a signature-polymorphic method.
217 if (cp_index >= _method_handle_invokers.length()) return;
218 int status = _method_handle_invokers.at(cp_index);
219 assert(status >= -1 && status <= 1, "oob tri-state");
220 if (status == 0) {
221 if (_pool->klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_MethodHandle() &&
222 MethodHandles::is_signature_polymorphic_name(SystemDictionary::MethodHandle_klass(),
223 _pool->name_ref_at(cp_index))) {
224 // we may need a resolved_refs entry for the appendix
225 add_invokedynamic_resolved_references_entry(cp_index, cache_index);
226 status = +1;
227 } else if (_pool->klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_VarHandle() &&
228 MethodHandles::is_signature_polymorphic_name(SystemDictionary::VarHandle_klass(),
229 _pool->name_ref_at(cp_index))) {
230 // we may need a resolved_refs entry for the appendix
231 add_invokedynamic_resolved_references_entry(cp_index, cache_index);
232 status = +1;
233 } else {
234 status = -1;
235 }
236 _method_handle_invokers.at(cp_index) = status;
237 }
238 // We use a special internal bytecode for such methods (if non-static).
239 // The basic reason for this is that such methods need an extra "appendix" argument
240 // to transmit the call site's intended call type.
241 if (status > 0) {
242 (*opc) = (u1)Bytecodes::_invokehandle;
243 }
244 }
245 } else {
246 // Do not need to look at cp_index.
247 if ((*opc) == (u1)Bytecodes::_invokehandle) {
248 (*opc) = (u1)Bytecodes::_invokevirtual;
249 // Ignore corner case of original _invokespecial instruction.
250 // This is safe because (a) the signature polymorphic method was final, and
251 // (b) the implementation of MethodHandle will not call invokespecial on it.
252 }
253 }
254 }
255
256
257 void Rewriter::rewrite_invokedynamic(address bcp, int offset, bool reverse) {
258 address p = bcp + offset;
259 assert(p[-1] == Bytecodes::_invokedynamic, "not invokedynamic bytecode");
260 if (!reverse) {
261 int cp_index = Bytes::get_Java_u2(p);
262 int cache_index = add_invokedynamic_cp_cache_entry(cp_index);
263 int resolved_index = add_invokedynamic_resolved_references_entry(cp_index, cache_index);
264 // Replace the trailing four bytes with a CPC index for the dynamic
265 // call site. Unlike other CPC entries, there is one per bytecode,
266 // not just one per distinct CP entry. In other words, the
267 // CPC-to-CP relation is many-to-one for invokedynamic entries.
268 // This means we must use a larger index size than u2 to address
269 // all these entries. That is the main reason invokedynamic
270 // must have a five-byte instruction format. (Of course, other JVM
271 // implementations can use the bytes for other purposes.)
272 // Note: We use native_u4 format exclusively for 4-byte indexes.
273 Bytes::put_native_u4(p, ConstantPool::encode_invokedynamic_index(cache_index));
274 // add the bcp in case we need to patch this bytecode if we also find a
275 // invokespecial/InterfaceMethodref in the bytecode stream
276 _patch_invokedynamic_bcps->push(p);
277 _patch_invokedynamic_refs->push(resolved_index);
278 } else {
279 int cache_index = ConstantPool::decode_invokedynamic_index(
280 Bytes::get_native_u4(p));
281 // We will reverse the bytecode rewriting _after_ adjusting them.
282 // Adjust the cache index by offset to the invokedynamic entries in the
283 // cpCache plus the delta if the invokedynamic bytecodes were adjusted.
284 int adjustment = cp_cache_delta() + _first_iteration_cp_cache_limit;
285 int cp_index = invokedynamic_cp_cache_entry_pool_index(cache_index - adjustment);
286 assert(_pool->tag_at(cp_index).is_invoke_dynamic(), "wrong index");
287 // zero out 4 bytes
288 Bytes::put_Java_u4(p, 0);
289 Bytes::put_Java_u2(p, cp_index);
290 }
291 }
292
293 void Rewriter::patch_invokedynamic_bytecodes() {
294 // If the end of the cp_cache is the same as after initializing with the
295 // cpool, nothing needs to be done. Invokedynamic bytecodes are at the
296 // correct offsets. ie. no invokespecials added
297 int delta = cp_cache_delta();
298 if (delta > 0) {
299 int length = _patch_invokedynamic_bcps->length();
300 assert(length == _patch_invokedynamic_refs->length(),
301 "lengths should match");
302 for (int i = 0; i < length; i++) {
303 address p = _patch_invokedynamic_bcps->at(i);
304 int cache_index = ConstantPool::decode_invokedynamic_index(
305 Bytes::get_native_u4(p));
306 Bytes::put_native_u4(p, ConstantPool::encode_invokedynamic_index(cache_index + delta));
307
308 // invokedynamic resolved references map also points to cp cache and must
309 // add delta to each.
310 int resolved_index = _patch_invokedynamic_refs->at(i);
311 assert(_invokedynamic_references_map.at(resolved_index) == cache_index,
312 "should be the same index");
313 _invokedynamic_references_map.at_put(resolved_index, cache_index + delta);
314 }
315 }
316 }
317
318
319 // Rewrite some ldc bytecodes to _fast_aldc
320 void Rewriter::maybe_rewrite_ldc(address bcp, int offset, bool is_wide,
321 bool reverse) {
322 if (!reverse) {
323 assert((*bcp) == (is_wide ? Bytecodes::_ldc_w : Bytecodes::_ldc), "not ldc bytecode");
324 address p = bcp + offset;
325 int cp_index = is_wide ? Bytes::get_Java_u2(p) : (u1)(*p);
326 constantTag tag = _pool->tag_at(cp_index).value();
327
328 if (tag.is_method_handle() ||
329 tag.is_method_type() ||
330 tag.is_string() ||
331 (tag.is_dynamic_constant() &&
332 // keep regular ldc interpreter logic for condy primitives
333 is_reference_type(FieldType::basic_type(_pool->uncached_signature_ref_at(cp_index))))
334 ) {
335 int ref_index = cp_entry_to_resolved_references(cp_index);
336 if (is_wide) {
337 (*bcp) = Bytecodes::_fast_aldc_w;
338 assert(ref_index == (u2)ref_index, "index overflow");
339 Bytes::put_native_u2(p, ref_index);
340 } else {
341 (*bcp) = Bytecodes::_fast_aldc;
342 assert(ref_index == (u1)ref_index, "index overflow");
343 (*p) = (u1)ref_index;
344 }
345 }
346 } else {
347 Bytecodes::Code rewritten_bc =
348 (is_wide ? Bytecodes::_fast_aldc_w : Bytecodes::_fast_aldc);
349 if ((*bcp) == rewritten_bc) {
350 address p = bcp + offset;
351 int ref_index = is_wide ? Bytes::get_native_u2(p) : (u1)(*p);
352 int pool_index = resolved_references_entry_to_pool_index(ref_index);
353 if (is_wide) {
354 (*bcp) = Bytecodes::_ldc_w;
355 assert(pool_index == (u2)pool_index, "index overflow");
356 Bytes::put_Java_u2(p, pool_index);
357 } else {
358 (*bcp) = Bytecodes::_ldc;
359 assert(pool_index == (u1)pool_index, "index overflow");
360 (*p) = (u1)pool_index;
361 }
362 }
363 }
364 }
365
366
367 // Rewrites a method given the index_map information
368 void Rewriter::scan_method(Method* method, bool reverse, bool* invokespecial_error) {
369
370 int nof_jsrs = 0;
371 bool has_monitor_bytecodes = false;
372 Bytecodes::Code c;
373
374 // Bytecodes and their length
375 const address code_base = method->code_base();
376 const int code_length = method->code_size();
377
378 int bc_length;
379 for (int bci = 0; bci < code_length; bci += bc_length) {
380 address bcp = code_base + bci;
381 int prefix_length = 0;
382 c = (Bytecodes::Code)(*bcp);
383
384 // Since we have the code, see if we can get the length
385 // directly. Some more complicated bytecodes will report
386 // a length of zero, meaning we need to make another method
387 // call to calculate the length.
388 bc_length = Bytecodes::length_for(c);
389 if (bc_length == 0) {
390 bc_length = Bytecodes::length_at(method, bcp);
391
392 // length_at will put us at the bytecode after the one modified
393 // by 'wide'. We don't currently examine any of the bytecodes
394 // modified by wide, but in case we do in the future...
395 if (c == Bytecodes::_wide) {
396 prefix_length = 1;
397 c = (Bytecodes::Code)bcp[1];
398 }
399 }
400
401 // Continuing with an invalid bytecode will fail in the loop below.
402 // So guarantee here.
403 guarantee(bc_length > 0, "Verifier should have caught this invalid bytecode");
404
405 switch (c) {
406 case Bytecodes::_lookupswitch : {
407 #ifndef CC_INTERP
408 Bytecode_lookupswitch bc(method, bcp);
409 (*bcp) = (
410 bc.number_of_pairs() < BinarySwitchThreshold
411 ? Bytecodes::_fast_linearswitch
412 : Bytecodes::_fast_binaryswitch
413 );
414 #endif
415 break;
416 }
417 case Bytecodes::_fast_linearswitch:
418 case Bytecodes::_fast_binaryswitch: {
419 #ifndef CC_INTERP
420 (*bcp) = Bytecodes::_lookupswitch;
421 #endif
422 break;
423 }
424
425 case Bytecodes::_invokespecial : {
426 rewrite_invokespecial(bcp, prefix_length+1, reverse, invokespecial_error);
427 break;
428 }
429
430 case Bytecodes::_putstatic :
431 case Bytecodes::_putfield : {
432 if (!reverse) {
433 // Check if any final field of the class given as parameter is modified
434 // outside of initializer methods of the class. Fields that are modified
435 // are marked with a flag. For marked fields, the compilers do not perform
436 // constant folding (as the field can be changed after initialization).
437 //
438 // The check is performed after verification and only if verification has
439 // succeeded. Therefore, the class is guaranteed to be well-formed.
440 InstanceKlass* klass = method->method_holder();
441 u2 bc_index = Bytes::get_Java_u2(bcp + prefix_length + 1);
442 constantPoolHandle cp(method->constants());
443 Symbol* ref_class_name = cp->klass_name_at(cp->klass_ref_index_at(bc_index));
444
445 if (klass->name() == ref_class_name) {
446 Symbol* field_name = cp->name_ref_at(bc_index);
447 Symbol* field_sig = cp->signature_ref_at(bc_index);
448
449 fieldDescriptor fd;
450 if (klass->find_field(field_name, field_sig, &fd) != NULL) {
451 if (fd.access_flags().is_final()) {
452 if (fd.access_flags().is_static()) {
453 if (!method->is_static_initializer()) {
454 fd.set_has_initialized_final_update(true);
455 }
456 } else {
457 if (!method->is_object_initializer()) {
458 fd.set_has_initialized_final_update(true);
459 }
460 }
461 }
462 }
463 }
464 }
465 }
466 // fall through
467 case Bytecodes::_getstatic : // fall through
468 case Bytecodes::_getfield : // fall through
469 case Bytecodes::_invokevirtual : // fall through
470 case Bytecodes::_invokestatic :
471 case Bytecodes::_invokeinterface:
472 case Bytecodes::_invokehandle : // if reverse=true
473 rewrite_member_reference(bcp, prefix_length+1, reverse);
474 break;
475 case Bytecodes::_invokedynamic:
476 rewrite_invokedynamic(bcp, prefix_length+1, reverse);
477 break;
478 case Bytecodes::_ldc:
479 case Bytecodes::_fast_aldc: // if reverse=true
480 maybe_rewrite_ldc(bcp, prefix_length+1, false, reverse);
481 break;
482 case Bytecodes::_ldc_w:
483 case Bytecodes::_fast_aldc_w: // if reverse=true
484 maybe_rewrite_ldc(bcp, prefix_length+1, true, reverse);
485 break;
486 case Bytecodes::_jsr : // fall through
487 case Bytecodes::_jsr_w : nof_jsrs++; break;
488 case Bytecodes::_monitorenter : // fall through
489 case Bytecodes::_monitorexit : has_monitor_bytecodes = true; break;
490
491 default: break;
492 }
493 }
494
495 // Update access flags
496 if (has_monitor_bytecodes) {
497 method->set_has_monitor_bytecodes();
498 }
499
500 // The present of a jsr bytecode implies that the method might potentially
501 // have to be rewritten, so we run the oopMapGenerator on the method
502 if (nof_jsrs > 0) {
503 method->set_has_jsrs();
504 // Second pass will revisit this method.
505 assert(method->has_jsrs(), "didn't we just set this?");
506 }
507 }
508
509 // After constant pool is created, revisit methods containing jsrs.
510 methodHandle Rewriter::rewrite_jsrs(const methodHandle& method, TRAPS) {
511 ResourceMark rm(THREAD);
512 ResolveOopMapConflicts romc(method);
513 methodHandle new_method = romc.do_potential_rewrite(CHECK_(methodHandle()));
514 // Update monitor matching info.
515 if (romc.monitor_safe()) {
516 new_method->set_guaranteed_monitor_matching();
517 }
518
519 return new_method;
520 }
521
522 void Rewriter::rewrite_bytecodes(TRAPS) {
523 assert(_pool->cache() == NULL, "constant pool cache must not be set yet");
524
525 // determine index maps for Method* rewriting
526 compute_index_maps();
527
528 if (RegisterFinalizersAtInit && _klass->name() == vmSymbols::java_lang_Object()) {
529 bool did_rewrite = false;
530 int i = _methods->length();
531 while (i-- > 0) {
532 Method* method = _methods->at(i);
533 if (method->intrinsic_id() == vmIntrinsics::_Object_init) {
534 // rewrite the return bytecodes of Object.<init> to register the
535 // object for finalization if needed.
536 methodHandle m(THREAD, method);
537 rewrite_Object_init(m, CHECK);
538 did_rewrite = true;
539 break;
540 }
541 }
542 assert(did_rewrite, "must find Object::<init> to rewrite it");
543 }
544
545 // rewrite methods, in two passes
546 int len = _methods->length();
547 bool invokespecial_error = false;
548
549 for (int i = len-1; i >= 0; i--) {
550 Method* method = _methods->at(i);
551 scan_method(method, false, &invokespecial_error);
552 if (invokespecial_error) {
553 // If you get an error here, there is no reversing bytecodes
554 // This exception is stored for this class and no further attempt is
555 // made at verifying or rewriting.
556 THROW_MSG(vmSymbols::java_lang_InternalError(),
557 "This classfile overflows invokespecial for interfaces "
558 "and cannot be loaded");
559 return;
560 }
561 }
562
563 // May have to fix invokedynamic bytecodes if invokestatic/InterfaceMethodref
564 // entries had to be added.
565 patch_invokedynamic_bytecodes();
566 }
567
568 void Rewriter::rewrite(InstanceKlass* klass, TRAPS) {
569 if (!DumpSharedSpaces) {
570 assert(!klass->is_shared(), "archive methods must not be rewritten at run time");
571 }
572 ResourceMark rm(THREAD);
573 Rewriter rw(klass, klass->constants(), klass->methods(), CHECK);
574 // (That's all, folks.)
575 }
576
577 Rewriter::Rewriter(InstanceKlass* klass, const constantPoolHandle& cpool, Array<Method*>* methods, TRAPS)
578 : _klass(klass),
579 _pool(cpool),
580 _methods(methods),
581 _cp_map(cpool->length()),
582 _cp_cache_map(cpool->length() / 2),
583 _reference_map(cpool->length()),
584 _resolved_references_map(cpool->length() / 2),
585 _invokedynamic_references_map(cpool->length() / 2),
586 _method_handle_invokers(cpool->length()),
587 _invokedynamic_cp_cache_map(cpool->length() / 4)
588 {
589
590 // Rewrite bytecodes - exception here exits.
591 rewrite_bytecodes(CHECK);
592
593 // Stress restoring bytecodes
594 if (StressRewriter) {
595 restore_bytecodes();
596 rewrite_bytecodes(CHECK);
597 }
598
599 // allocate constant pool cache, now that we've seen all the bytecodes
600 make_constant_pool_cache(THREAD);
601
602 // Restore bytecodes to their unrewritten state if there are exceptions
603 // rewriting bytecodes or allocating the cpCache
604 if (HAS_PENDING_EXCEPTION) {
605 restore_bytecodes();
606 return;
607 }
608
609 // Relocate after everything, but still do this under the is_rewritten flag,
610 // so methods with jsrs in custom class lists in aren't attempted to be
611 // rewritten in the RO section of the shared archive.
612 // Relocated bytecodes don't have to be restored, only the cp cache entries
613 int len = _methods->length();
614 for (int i = len-1; i >= 0; i--) {
615 methodHandle m(THREAD, _methods->at(i));
616
617 if (m->has_jsrs()) {
618 m = rewrite_jsrs(m, THREAD);
619 // Restore bytecodes to their unrewritten state if there are exceptions
620 // relocating bytecodes. If some are relocated, that is ok because that
621 // doesn't affect constant pool to cpCache rewriting.
622 if (HAS_PENDING_EXCEPTION) {
623 restore_bytecodes();
624 return;
625 }
626 // Method might have gotten rewritten.
627 methods->at_put(i, m());
628 }
629 }
630 }