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/cds_globals.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/metaspaceShared.hpp"
29 #include "classfile/vmClasses.hpp"
30 #include "interpreter/bytecodes.hpp"
31 #include "interpreter/bytecodeStream.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "interpreter/rewriter.hpp"
34 #include "memory/metadataFactory.hpp"
35 #include "memory/resourceArea.hpp"
36 #include "oops/generateOopMap.hpp"
37 #include "oops/resolvedFieldEntry.hpp"
38 #include "oops/resolvedIndyEntry.hpp"
39 #include "oops/resolvedMethodEntry.hpp"
40 #include "prims/methodHandles.hpp"
41 #include "runtime/fieldDescriptor.inline.hpp"
42 #include "runtime/handles.inline.hpp"
43 #include "utilities/checkedCast.hpp"
44
45 // Computes a CPC map (new_index -> original_index) for constant pool entries
46 // that are referred to by the interpreter at runtime via the constant pool cache.
47 // Also computes a CP map (original_index -> new_index).
48 // Marks entries in CP which require additional processing.
49 void Rewriter::compute_index_maps() {
50 const int length = _pool->length();
51 init_maps(length);
52 bool saw_mh_symbol = false;
53 for (int i = 0; i < length; i++) {
54 int tag = _pool->tag_at(i).value();
55 switch (tag) {
56 case JVM_CONSTANT_Fieldref :
57 _cp_map.at_put(i, _field_entry_index);
58 _field_entry_index++;
59 _initialized_field_entries.push(ResolvedFieldEntry((u2)i));
60 break;
61 case JVM_CONSTANT_InterfaceMethodref: // fall through
62 case JVM_CONSTANT_Methodref :
63 _cp_map.at_put(i, _method_entry_index);
64 _method_entry_index++;
65 _initialized_method_entries.push(ResolvedMethodEntry((u2)i));
66 break;
67 case JVM_CONSTANT_Dynamic:
68 assert(_pool->has_dynamic_constant(), "constant pool's _has_dynamic_constant flag not set");
69 add_resolved_references_entry(i);
70 break;
71 case JVM_CONSTANT_String : // fall through
72 case JVM_CONSTANT_MethodHandle : // fall through
73 case JVM_CONSTANT_MethodType : // fall through
74 add_resolved_references_entry(i);
75 break;
76 case JVM_CONSTANT_Utf8:
77 if (_pool->symbol_at(i) == vmSymbols::java_lang_invoke_MethodHandle() ||
78 _pool->symbol_at(i) == vmSymbols::java_lang_invoke_VarHandle()) {
79 saw_mh_symbol = true;
80 }
81 break;
82 }
83 }
84
85 // Record limits of resolved reference map for constant pool cache indices
86 record_map_limits();
87
88 guarantee(_initialized_field_entries.length() - 1 <= (int)((u2)-1), "All resolved field indices fit in a u2");
89 guarantee(_initialized_method_entries.length() - 1 <= (int)((u2)-1), "All resolved method indices fit in a u2");
90
91 if (saw_mh_symbol) {
92 _method_handle_invokers.at_grow(length, 0);
93 }
94 }
95
96 // Unrewrite the bytecodes if an error occurs.
97 void Rewriter::restore_bytecodes(Thread* thread) {
98 int len = _methods->length();
99 bool invokespecial_error = false;
100
101 for (int i = len-1; i >= 0; i--) {
102 Method* method = _methods->at(i);
103 scan_method(thread, method, true, &invokespecial_error);
104 assert(!invokespecial_error, "reversing should not get an invokespecial error");
105 }
106 }
107
108 // Creates a constant pool cache given a CPC map
109 void Rewriter::make_constant_pool_cache(TRAPS) {
110 ClassLoaderData* loader_data = _pool->pool_holder()->class_loader_data();
111 assert(_field_entry_index == _initialized_field_entries.length(), "Field entry size mismatch");
112 assert(_method_entry_index == _initialized_method_entries.length(), "Method entry size mismatch");
113 ConstantPoolCache* cache =
114 ConstantPoolCache::allocate(loader_data, _invokedynamic_references_map,
115 _initialized_indy_entries, _initialized_field_entries, _initialized_method_entries,
116 CHECK);
117
118 // initialize object cache in constant pool
119 _pool->set_cache(cache);
120 cache->set_constant_pool(_pool());
121
122 // _resolved_references is stored in pool->cache(), so need to be done after
123 // the above lines.
124 _pool->initialize_resolved_references(loader_data, _resolved_references_map,
125 _resolved_reference_limit,
126 THREAD);
127 #if INCLUDE_CDS
128 if (!HAS_PENDING_EXCEPTION && CDSConfig::is_dumping_archive()) {
129 if (_pool->pool_holder()->is_shared()) {
130 assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
131 // We are linking a shared class from the base archive. This
132 // class won't be written into the dynamic archive, so there's no
133 // need to save its CpCaches.
134 }
135 }
136 #endif
137
138 // Clean up constant pool cache if initialize_resolved_references() failed.
139 if (HAS_PENDING_EXCEPTION) {
140 MetadataFactory::free_metadata(loader_data, cache);
141 _pool->set_cache(nullptr); // so the verifier isn't confused
142 }
143 }
144
145
146
147 // The new finalization semantics says that registration of
148 // finalizable objects must be performed on successful return from the
149 // Object.<init> constructor. We could implement this trivially if
150 // <init> were never rewritten but since JVMTI allows this to occur, a
151 // more complicated solution is required. A special return bytecode
152 // is used only by Object.<init> to signal the finalization
153 // registration point. Additionally local 0 must be preserved so it's
154 // available to pass to the registration function. For simplicity we
155 // require that local 0 is never overwritten so it's available as an
156 // argument for registration.
157
158 void Rewriter::rewrite_Object_init(const methodHandle& method, TRAPS) {
159 RawBytecodeStream bcs(method);
160 while (!bcs.is_last_bytecode()) {
161 Bytecodes::Code opcode = bcs.raw_next();
162 switch (opcode) {
163 case Bytecodes::_return: *bcs.bcp() = Bytecodes::_return_register_finalizer; break;
164
165 case Bytecodes::_istore:
166 case Bytecodes::_lstore:
167 case Bytecodes::_fstore:
168 case Bytecodes::_dstore:
169 case Bytecodes::_astore:
170 if (bcs.get_index() != 0) continue;
171
172 // fall through
173 case Bytecodes::_istore_0:
174 case Bytecodes::_lstore_0:
175 case Bytecodes::_fstore_0:
176 case Bytecodes::_dstore_0:
177 case Bytecodes::_astore_0:
178 THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(),
179 "can't overwrite local 0 in Object.<init>");
180 break;
181
182 default:
183 break;
184 }
185 }
186 }
187
188
189 void Rewriter::rewrite_field_reference(address bcp, int offset, bool reverse) {
190 address p = bcp + offset;
191 if (!reverse) {
192 int cp_index = Bytes::get_Java_u2(p);
193 int field_entry_index = _cp_map.at(cp_index);
194 Bytes::put_native_u2(p, checked_cast<u2>(field_entry_index));
195 } else {
196 int field_entry_index = Bytes::get_native_u2(p);
197 int pool_index = _initialized_field_entries.at(field_entry_index).constant_pool_index();
198 Bytes::put_Java_u2(p, checked_cast<u2>(pool_index));
199 }
200 }
201
202 void Rewriter::rewrite_method_reference(address bcp, int offset, bool reverse) {
203 address p = bcp + offset;
204 if (!reverse) {
205 int cp_index = Bytes::get_Java_u2(p);
206 int method_entry_index = _cp_map.at(cp_index);
207 Bytes::put_native_u2(p, (u2)method_entry_index);
208 if (!_method_handle_invokers.is_empty()) {
209 maybe_rewrite_invokehandle(p - 1, cp_index, method_entry_index, reverse);
210 }
211 } else {
212 int method_entry_index = Bytes::get_native_u2(p);
213 int pool_index = _initialized_method_entries.at(method_entry_index).constant_pool_index();
214 Bytes::put_Java_u2(p, (u2)pool_index);
215 if (!_method_handle_invokers.is_empty()) {
216 maybe_rewrite_invokehandle(p - 1, pool_index, method_entry_index, reverse);
217 }
218 }
219 }
220
221 // If the constant pool entry for invokespecial is InterfaceMethodref,
222 // we need to add a separate cpCache entry for its resolution, because it is
223 // different than the resolution for invokeinterface with InterfaceMethodref.
224 // These cannot share cpCache entries.
225 void Rewriter::rewrite_invokespecial(address bcp, int offset, bool reverse, bool* invokespecial_error) {
226 address p = bcp + offset;
227 if (!reverse) {
228 int cp_index = Bytes::get_Java_u2(p);
229 if (_pool->tag_at(cp_index).is_interface_method()) {
230 _initialized_method_entries.push(ResolvedMethodEntry((u2)cp_index));
231 Bytes::put_native_u2(p, (u2)_method_entry_index);
232 _method_entry_index++;
233 if (_method_entry_index != (int)(u2)_method_entry_index) {
234 *invokespecial_error = true;
235 }
236 } else {
237 rewrite_method_reference(bcp, offset, reverse);
238 }
239 } else {
240 rewrite_method_reference(bcp, offset, reverse);
241 }
242 }
243
244 // Adjust the invocation bytecode for a signature-polymorphic method (MethodHandle.invoke, etc.)
245 void Rewriter::maybe_rewrite_invokehandle(address opc, int cp_index, int cache_index, bool reverse) {
246 if (!reverse) {
247 if ((*opc) == (u1)Bytecodes::_invokevirtual ||
248 // allow invokespecial as an alias, although it would be very odd:
249 ((*opc) == (u1)Bytecodes::_invokespecial)) {
250 assert(_pool->tag_at(cp_index).is_method(), "wrong index");
251 // Determine whether this is a signature-polymorphic method.
252 if (cp_index >= _method_handle_invokers.length()) return;
253 int status = _method_handle_invokers.at(cp_index);
254 assert(status >= -1 && status <= 1, "oob tri-state");
255 if (status == 0) {
256 if (_pool->uncached_klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_MethodHandle() &&
257 MethodHandles::is_signature_polymorphic_name(vmClasses::MethodHandle_klass(),
258 _pool->uncached_name_ref_at(cp_index))) {
259 // we may need a resolved_refs entry for the appendix
260 int resolved_index = add_invokedynamic_resolved_references_entry(cp_index, cache_index);
261 _initialized_method_entries.at(cache_index).set_resolved_references_index((u2)resolved_index);
262 status = +1;
263 } else if (_pool->uncached_klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_VarHandle() &&
264 MethodHandles::is_signature_polymorphic_name(vmClasses::VarHandle_klass(),
265 _pool->uncached_name_ref_at(cp_index))) {
266 // we may need a resolved_refs entry for the appendix
267 int resolved_index = add_invokedynamic_resolved_references_entry(cp_index, cache_index);
268 _initialized_method_entries.at(cache_index).set_resolved_references_index((u2)resolved_index);
269 status = +1;
270 } else {
271 status = -1;
272 }
273 _method_handle_invokers.at(cp_index) = status;
274 }
275 // We use a special internal bytecode for such methods (if non-static).
276 // The basic reason for this is that such methods need an extra "appendix" argument
277 // to transmit the call site's intended call type.
278 if (status > 0) {
279 (*opc) = (u1)Bytecodes::_invokehandle;
280 }
281 }
282 } else {
283 // Do not need to look at cp_index.
284 if ((*opc) == (u1)Bytecodes::_invokehandle) {
285 (*opc) = (u1)Bytecodes::_invokevirtual;
286 // Ignore corner case of original _invokespecial instruction.
287 // This is safe because (a) the signature polymorphic method was final, and
288 // (b) the implementation of MethodHandle will not call invokespecial on it.
289 }
290 }
291 }
292
293
294 void Rewriter::rewrite_invokedynamic(address bcp, int offset, bool reverse) {
295 address p = bcp + offset;
296 assert(p[-1] == Bytecodes::_invokedynamic, "not invokedynamic bytecode");
297 if (!reverse) {
298 int cp_index = Bytes::get_Java_u2(p);
299 int resolved_index = add_invokedynamic_resolved_references_entry(cp_index, -1); // Indy no longer has a CPCE
300 // Replace the trailing four bytes with an index to the array of
301 // indy resolution information in the CPC. There is one entry for
302 // each bytecode, even if they make the same call. In other words,
303 // the CPC-to-CP relation is many-to-one for invokedynamic entries.
304 // This means we must use a larger index size than u2 to address
305 // all these entries. That is the main reason invokedynamic
306 // must have a five-byte instruction format. (Of course, other JVM
307 // implementations can use the bytes for other purposes.)
308 // Note: We use native_u4 format exclusively for 4-byte indexes.
309 Bytes::put_native_u4(p, (u2)_invokedynamic_index);
310 _invokedynamic_index++;
311
312 // Collect invokedynamic information before creating ResolvedInvokeDynamicInfo array
313 _initialized_indy_entries.push(ResolvedIndyEntry((u2)resolved_index, (u2)cp_index));
314 } else {
315 // Should do nothing since we are not patching this bytecode
316 int cache_index = Bytes::get_native_u4(p);
317 int cp_index = _initialized_indy_entries.at(cache_index).constant_pool_index();
318 assert(_pool->tag_at(cp_index).is_invoke_dynamic(), "wrong index");
319 // zero out 4 bytes
320 Bytes::put_Java_u4(p, 0);
321 Bytes::put_Java_u2(p, (u2)cp_index);
322 }
323 }
324
325 // Rewrite some ldc bytecodes to _fast_aldc
326 void Rewriter::maybe_rewrite_ldc(address bcp, int offset, bool is_wide,
327 bool reverse) {
328 if (!reverse) {
329 assert((*bcp) == (is_wide ? Bytecodes::_ldc_w : Bytecodes::_ldc), "not ldc bytecode");
330 address p = bcp + offset;
331 int cp_index = is_wide ? Bytes::get_Java_u2(p) : (u1)(*p);
332 constantTag tag = _pool->tag_at(cp_index).value();
333
334 if (tag.is_method_handle() ||
335 tag.is_method_type() ||
336 tag.is_string() ||
337 (tag.is_dynamic_constant() &&
338 // keep regular ldc interpreter logic for condy primitives
339 is_reference_type(Signature::basic_type(_pool->uncached_signature_ref_at(cp_index))))
340 ) {
341 int ref_index = cp_entry_to_resolved_references(cp_index);
342 if (is_wide) {
343 (*bcp) = Bytecodes::_fast_aldc_w;
344 assert(ref_index == (u2)ref_index, "index overflow");
345 Bytes::put_native_u2(p, (u2)ref_index);
346 } else {
347 (*bcp) = Bytecodes::_fast_aldc;
348 assert(ref_index == (u1)ref_index, "index overflow");
349 (*p) = (u1)ref_index;
350 }
351 }
352 } else {
353 Bytecodes::Code rewritten_bc =
354 (is_wide ? Bytecodes::_fast_aldc_w : Bytecodes::_fast_aldc);
355 if ((*bcp) == rewritten_bc) {
356 address p = bcp + offset;
357 int ref_index = is_wide ? Bytes::get_native_u2(p) : (u1)(*p);
358 int pool_index = resolved_references_entry_to_pool_index(ref_index);
359 if (is_wide) {
360 (*bcp) = Bytecodes::_ldc_w;
361 assert(pool_index == (u2)pool_index, "index overflow");
362 Bytes::put_Java_u2(p, (u2)pool_index);
363 } else {
364 (*bcp) = Bytecodes::_ldc;
365 assert(pool_index == (u1)pool_index, "index overflow");
366 (*p) = (u1)pool_index;
367 }
368 }
369 }
370 }
371
372
373 // Rewrites a method given the index_map information
374 void Rewriter::scan_method(Thread* thread, Method* method, bool reverse, bool* invokespecial_error) {
375
376 int nof_jsrs = 0;
377 bool has_monitor_bytecodes = false;
378 Bytecodes::Code c;
379
380 // Bytecodes and their length
381 const address code_base = method->code_base();
382 const int code_length = method->code_size();
383
384 int bc_length;
385 for (int bci = 0; bci < code_length; bci += bc_length) {
386 address bcp = code_base + bci;
387 int prefix_length = 0;
388 c = (Bytecodes::Code)(*bcp);
389
390 // Since we have the code, see if we can get the length
391 // directly. Some more complicated bytecodes will report
392 // a length of zero, meaning we need to make another method
393 // call to calculate the length.
394 bc_length = Bytecodes::length_for(c);
395 if (bc_length == 0) {
396 bc_length = Bytecodes::length_at(method, bcp);
397
398 // length_at will put us at the bytecode after the one modified
399 // by 'wide'. We don't currently examine any of the bytecodes
400 // modified by wide, but in case we do in the future...
401 if (c == Bytecodes::_wide) {
402 prefix_length = 1;
403 c = (Bytecodes::Code)bcp[1];
404 }
405 }
406
407 // Continuing with an invalid bytecode will fail in the loop below.
408 // So guarantee here.
409 guarantee(bc_length > 0, "Verifier should have caught this invalid bytecode");
410
411 switch (c) {
412 case Bytecodes::_lookupswitch : {
413 #ifndef ZERO
414 Bytecode_lookupswitch bc(method, bcp);
415 (*bcp) = (
416 bc.number_of_pairs() < BinarySwitchThreshold
417 ? Bytecodes::_fast_linearswitch
418 : Bytecodes::_fast_binaryswitch
419 );
420 #endif
421 break;
422 }
423 case Bytecodes::_fast_linearswitch:
424 case Bytecodes::_fast_binaryswitch: {
425 #ifndef ZERO
426 (*bcp) = Bytecodes::_lookupswitch;
427 #endif
428 break;
429 }
430
431 case Bytecodes::_invokespecial : {
432 rewrite_invokespecial(bcp, prefix_length+1, reverse, invokespecial_error);
433 break;
434 }
435
436 case Bytecodes::_putstatic :
437 case Bytecodes::_putfield : {
438 if (!reverse) {
439 // Check if any final field of the class given as parameter is modified
440 // outside of initializer methods of the class. Fields that are modified
441 // are marked with a flag. For marked fields, the compilers do not perform
442 // constant folding (as the field can be changed after initialization).
443 //
444 // The check is performed after verification and only if verification has
445 // succeeded. Therefore, the class is guaranteed to be well-formed.
446 InstanceKlass* klass = method->method_holder();
447 u2 bc_index = Bytes::get_Java_u2(bcp + prefix_length + 1);
448 constantPoolHandle cp(thread, method->constants());
449 Symbol* ref_class_name = cp->klass_name_at(cp->uncached_klass_ref_index_at(bc_index));
450
451 if (klass->name() == ref_class_name) {
452 Symbol* field_name = cp->uncached_name_ref_at(bc_index);
453 Symbol* field_sig = cp->uncached_signature_ref_at(bc_index);
454
455 fieldDescriptor fd;
456 if (klass->find_field(field_name, field_sig, &fd) != nullptr) {
457 if (fd.access_flags().is_final()) {
458 if (fd.access_flags().is_static()) {
459 if (!method->is_static_initializer()) {
460 fd.set_has_initialized_final_update(true);
461 }
462 } else {
463 if (!method->is_object_initializer()) {
464 fd.set_has_initialized_final_update(true);
465 }
466 }
467 }
468 }
469 }
470 }
471 }
472 // fall through
473 case Bytecodes::_getstatic : // fall through
474 case Bytecodes::_getfield : // fall through
475 rewrite_field_reference(bcp, prefix_length+1, reverse);
476 break;
477 case Bytecodes::_invokevirtual : // fall through
478 case Bytecodes::_invokestatic :
479 case Bytecodes::_invokeinterface:
480 case Bytecodes::_invokehandle : // if reverse=true
481 rewrite_method_reference(bcp, prefix_length+1, reverse);
482 break;
483 case Bytecodes::_invokedynamic:
484 rewrite_invokedynamic(bcp, prefix_length+1, reverse);
485 break;
486 case Bytecodes::_ldc:
487 case Bytecodes::_fast_aldc: // if reverse=true
488 maybe_rewrite_ldc(bcp, prefix_length+1, false, reverse);
489 break;
490 case Bytecodes::_ldc_w:
491 case Bytecodes::_fast_aldc_w: // if reverse=true
492 maybe_rewrite_ldc(bcp, prefix_length+1, true, reverse);
493 break;
494 case Bytecodes::_jsr : // fall through
495 case Bytecodes::_jsr_w : nof_jsrs++; break;
496 case Bytecodes::_monitorenter : // fall through
497 case Bytecodes::_monitorexit : has_monitor_bytecodes = true; break;
498
499 default: break;
500 }
501 }
502
503 // Update flags
504 if (has_monitor_bytecodes) {
505 method->set_has_monitor_bytecodes();
506 }
507
508 // The present of a jsr bytecode implies that the method might potentially
509 // have to be rewritten, so we run the oopMapGenerator on the method
510 if (nof_jsrs > 0) {
511 method->set_has_jsrs();
512 }
513 }
514
515 // After constant pool is created, revisit methods containing jsrs.
516 methodHandle Rewriter::rewrite_jsrs(const methodHandle& method, TRAPS) {
517 ResourceMark rm(THREAD);
518 ResolveOopMapConflicts romc(method);
519 methodHandle new_method = romc.do_potential_rewrite(CHECK_(methodHandle()));
520 // Update monitor matching info.
521 if (romc.monitor_safe()) {
522 new_method->set_guaranteed_monitor_matching();
523 }
524
525 return new_method;
526 }
527
528 void Rewriter::rewrite_bytecodes(TRAPS) {
529 assert(_pool->cache() == nullptr, "constant pool cache must not be set yet");
530
531 // determine index maps for Method* rewriting
532 compute_index_maps();
533
534 if (_klass->name() == vmSymbols::java_lang_Object()) {
535 bool did_rewrite = false;
536 int i = _methods->length();
537 while (i-- > 0) {
538 Method* method = _methods->at(i);
539 if (method->intrinsic_id() == vmIntrinsics::_Object_init) {
540 // rewrite the return bytecodes of Object.<init> to register the
541 // object for finalization if needed.
542 methodHandle m(THREAD, method);
543 rewrite_Object_init(m, CHECK);
544 did_rewrite = true;
545 break;
546 }
547 }
548 assert(did_rewrite, "must find Object::<init> to rewrite it");
549 }
550
551 // rewrite methods, in two passes
552 int len = _methods->length();
553 bool invokespecial_error = false;
554
555 for (int i = len-1; i >= 0; i--) {
556 Method* method = _methods->at(i);
557 scan_method(THREAD, method, false, &invokespecial_error);
558 if (invokespecial_error) {
559 // If you get an error here, there is no reversing bytecodes
560 // This exception is stored for this class and no further attempt is
561 // made at verifying or rewriting.
562 THROW_MSG(vmSymbols::java_lang_InternalError(),
563 "This classfile overflows invokespecial for interfaces "
564 "and cannot be loaded");
565 return;
566 }
567 }
568 }
569
570 void Rewriter::rewrite(InstanceKlass* klass, TRAPS) {
571 #if INCLUDE_CDS
572 if (klass->is_shared()) {
573 assert(!klass->is_rewritten(), "rewritten shared classes cannot be rewritten again");
574 }
575 #endif // INCLUDE_CDS
576 ResourceMark rm(THREAD);
577 constantPoolHandle cpool(THREAD, klass->constants());
578 Rewriter rw(klass, cpool, klass->methods(), CHECK);
579 // (That's all, folks.)
580 }
581
582 Rewriter::Rewriter(InstanceKlass* klass, const constantPoolHandle& cpool, Array<Method*>* methods, TRAPS)
583 : _klass(klass),
584 _pool(cpool),
585 _methods(methods),
586 _cp_map(cpool->length()),
587 _reference_map(cpool->length()),
588 _resolved_references_map(cpool->length() / 2),
589 _invokedynamic_references_map(cpool->length() / 2),
590 _method_handle_invokers(cpool->length()),
591 _invokedynamic_index(0),
592 _field_entry_index(0),
593 _method_entry_index(0)
594 {
595
596 // Rewrite bytecodes - exception here exits.
597 rewrite_bytecodes(CHECK);
598
599 // Stress restoring bytecodes
600 if (StressRewriter) {
601 restore_bytecodes(THREAD);
602 rewrite_bytecodes(CHECK);
603 }
604
605 // allocate constant pool cache, now that we've seen all the bytecodes
606 make_constant_pool_cache(THREAD);
607
608 // Restore bytecodes to their unrewritten state if there are exceptions
609 // rewriting bytecodes or allocating the cpCache
610 if (HAS_PENDING_EXCEPTION) {
611 restore_bytecodes(THREAD);
612 return;
613 }
614
615 // Relocate after everything, but still do this under the is_rewritten flag,
616 // so methods with jsrs in custom class lists in aren't attempted to be
617 // rewritten in the RO section of the shared archive.
618 // Relocated bytecodes don't have to be restored, only the cp cache entries
619 int len = _methods->length();
620 for (int i = len-1; i >= 0; i--) {
621 methodHandle m(THREAD, _methods->at(i));
622
623 if (m->has_jsrs()) {
624 m = rewrite_jsrs(m, THREAD);
625 // Restore bytecodes to their unrewritten state if there are exceptions
626 // relocating bytecodes. If some are relocated, that is ok because that
627 // doesn't affect constant pool to cpCache rewriting.
628 if (HAS_PENDING_EXCEPTION) {
629 restore_bytecodes(THREAD);
630 return;
631 }
632 // Method might have gotten rewritten.
633 methods->at_put(i, m());
634 }
635 }
636 }