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